Vaping Illnesses Are Linked to Vitamin E Acetate, C.D.C. Says
(originally posted 14 Nov 2019)
Good morning all,
As we remain on-schedule, we will not meet in-person for lecture on Friday (15 Nov). I'd like instead to offer you several pieces of recent science news:
We have considered issues surrounding vaping several times this terms, most recently the alarming and poorly-understood severe respiratory distress that has developed in otherwise healthy individuals who vape. After several months of investigation, our CDC (Centers for Disease Control and Prevention) have released a report that appears to identify the likely cause of his distress syndrome: vitamin E acetate, and oily compound used as a additive in some vaping products.
https://www.cdc.gov/mmwr/volumes/68/wr/mm6845e2.htm?s_cid=mm6845e2_w
Vitamin E and its derivatives are lipophilic (fat soluble), which allows them to interact with cell membranes more easily than most biological compounds (which are hydrophilic, or lipophobic). Multiple samples of lung tissue from persons afflicted with vaping-associated respiratory distress have revealed this compound adhering to the lung surface. If you remember our discussions on lung structure/function, we described the exchange surface between the alveoli and the capillaries of the lungs as being as thin as possible (essentially, two single-cell layers of epithelium), to allow as much gas diffusion across them as possible. Now, imagine that same surface covered with a sticky, oily residue - it's easy to see that gas exchange could be severely impaired.
There may be other substances contributing to this distress syndrome, and not all experts are convinced that vitamin E acetate is the culprit. But, the evidence is accumulating, and it appears likely to be the primary cause of the cases investigated so far.
https://www.nytimes.com/2019/11/08/health/vaping-illness-cdc.html
If you do vape, check your products - do they list this as an additive? Can you select other materials that do not?
Juul, one of the largest companies producing vaping products, recently agreed to stop making some kinds of flavored vaping products, as they and others in the industry were being accused of improper marketing toward minors:
https://www.cnn.com/2019/11/07/health/juul-mint-pods-bn/index.html
One young person with vaping-associated respiratory distress recently was forced to undergo a double lung transplant:
https://www.reuters.com/article/us-health-vaping-transplant/michigan-boy-17-gets-double-lung-transplant-after-damage-from-vaping-idUSKBN1XN04R
Vaping seems like a habit to be avoided at all costs, in my view. Our lung tissue is simply not designed to handle contact with things other than atmospheric gases. In a few years, we may look back at this as a trend that appeared, and briefly flourished, before its significant health implications were well-understood. I suspect that regulations around vaping will get tighter and tighter, and the available evidence suggests that our public health would be best served by limiting access to vaping materials and more carefully regulating their contents.
Have a great rest of the week - see you on Monday for Chapter 22 (DNA Biology and Technology).
Sincerely,
Dr. Nealen
(originally posted 14 Nov 2019)
Good morning all,
As we remain on-schedule, we will not meet in-person for lecture on Friday (15 Nov). I'd like instead to offer you several pieces of recent science news:
We have considered issues surrounding vaping several times this terms, most recently the alarming and poorly-understood severe respiratory distress that has developed in otherwise healthy individuals who vape. After several months of investigation, our CDC (Centers for Disease Control and Prevention) have released a report that appears to identify the likely cause of his distress syndrome: vitamin E acetate, and oily compound used as a additive in some vaping products.
https://www.cdc.gov/mmwr/volumes/68/wr/mm6845e2.htm?s_cid=mm6845e2_w
Vitamin E and its derivatives are lipophilic (fat soluble), which allows them to interact with cell membranes more easily than most biological compounds (which are hydrophilic, or lipophobic). Multiple samples of lung tissue from persons afflicted with vaping-associated respiratory distress have revealed this compound adhering to the lung surface. If you remember our discussions on lung structure/function, we described the exchange surface between the alveoli and the capillaries of the lungs as being as thin as possible (essentially, two single-cell layers of epithelium), to allow as much gas diffusion across them as possible. Now, imagine that same surface covered with a sticky, oily residue - it's easy to see that gas exchange could be severely impaired.
There may be other substances contributing to this distress syndrome, and not all experts are convinced that vitamin E acetate is the culprit. But, the evidence is accumulating, and it appears likely to be the primary cause of the cases investigated so far.
https://www.nytimes.com/2019/11/08/health/vaping-illness-cdc.html
If you do vape, check your products - do they list this as an additive? Can you select other materials that do not?
Juul, one of the largest companies producing vaping products, recently agreed to stop making some kinds of flavored vaping products, as they and others in the industry were being accused of improper marketing toward minors:
https://www.cnn.com/2019/11/07/health/juul-mint-pods-bn/index.html
One young person with vaping-associated respiratory distress recently was forced to undergo a double lung transplant:
https://www.reuters.com/article/us-health-vaping-transplant/michigan-boy-17-gets-double-lung-transplant-after-damage-from-vaping-idUSKBN1XN04R
Vaping seems like a habit to be avoided at all costs, in my view. Our lung tissue is simply not designed to handle contact with things other than atmospheric gases. In a few years, we may look back at this as a trend that appeared, and briefly flourished, before its significant health implications were well-understood. I suspect that regulations around vaping will get tighter and tighter, and the available evidence suggests that our public health would be best served by limiting access to vaping materials and more carefully regulating their contents.
Have a great rest of the week - see you on Monday for Chapter 22 (DNA Biology and Technology).
Sincerely,
Dr. Nealen
Revamped cancer drug starves tumors in mice | Science | AAAS
(originally posted 08 Nov 2019)
Good morning all,
As I noted in lecture on Wednesday, we remain caught-up with our lecture schedule and do not have chapter assigned for today. So, we will not meet in person for class today; instead I will offer this reading which I would like to you to consider.
In our last lecture, we identified the "cell cycle" as a way to describe the normal lifespan of a cell, from its formation, through its functional life, and then its eventual end. All of our body cells are formed from mitotic cell division to begin their life, and, at the end of their functional lives, many of our cells undergo division themselves, essentially being reborn as two new daughter cells.
We also identified important "checkpoints" in the cell cycle, to prevent cells from speeding through the cell cycle too rapidly. Many of our cells have functional lives of months to years, and without these checkpoints, they would otherwise just divide rapidly into new cells. As we noted, failure to stop at these cell cycle checkpoints can lead to tumors caused by uncontrolled growth; some tumors can become cancers, invading otherwise normal tissues and causing them to become cancerous as well.
As you know, cancer is one of the primary causes of human mortality. We experience a variety of cancers: some are slow to progress, others very rapid; some are essentially benign while others are very deadly; some are highly invasive and others less so. The diversity if cancers we experience and the diversity of tissues that they strike represents one the of the primary difficulties in treating cancer: there is no single cure, for cancer is very diverse in its many forms.
That's not to say that there aren't standardized treatments. Most hospitals have oncology boards that carefully document each occurrence of cancer, and they typically made treatment decisions based upon consultation among a team of physicians, including oncologists, radiologists, surgeons, and others. Much of their decision-making is based upon care standards that have been developed by national and international cancer agencies, such as our own American Cancer Society, which suggests treatment guidelines for the different forms of cancer. Still, we know all too well that curing cancer is difficult, and sometime impossible. The best one can hope for is to eliminate the cancerous tissue to the point at which is cannot be detected, but that is no promise that every cancerous cell has been removed, nor that it cannot re-appear.
Because of the burden cancer poses to society, there are many federally-funded research groups investigating potential treatments. These include
Of course, many of the latest treatments combine multiple approaches, such as using immune cells to target delivery of cytotoxic drugs directly to cancer cells.
In the news this week is report of a promising new approach to treating some kinds of cancer, based upon a metabolic starving of cancer cells. Cells that are rapidly dividing (such as those within a tumor or a cancer) are metabolically very demanding, needing large amounts of fuel. Scientists have developed methods to prevent cells from using glutamine (a glucose-like fuel source), to successfully prevent cancer growth. But, earlier formations of this treatment caused widespread side effects, because the cancer cells were not the only ones being starved of fuel.
In this latest test, the scientists successfully "handcuffed" an inactive form of their drug to allow its focal delivery to cancer cells, where it was "unhandcuffed" into an active form by cancer cell enzymes. There it successfully prevented cancer growth. Even better, this new treatment actually improved immune T-cell function, providing an immunological boost to cancer elimination as well.
These initial studies, done in mice, were very promising. While the road from animal studies to human uses is often long and unsure, this could mark the beginnings of a new generation of cancer treatments that are improved in their focused targeting as well as in their effectiveness at cancer elimination.
https://www.sciencemag.org/news/2019/11/revamped-cancer-drug-starves-tumors-mice
We'll talk more about cancer in our upcoming lectures, and I hope that this article will put some of the lecture material into practical context. Cancer touches many families, and does not discriminate by race, class, knowledge, or upbringing. May your generation be the one that finally reduces the impact that it has on our individual and our public health.
Have a great weekend - see you on Monday.
Sincerely,
Dr. Nealen
(originally posted 08 Nov 2019)
Good morning all,
As I noted in lecture on Wednesday, we remain caught-up with our lecture schedule and do not have chapter assigned for today. So, we will not meet in person for class today; instead I will offer this reading which I would like to you to consider.
In our last lecture, we identified the "cell cycle" as a way to describe the normal lifespan of a cell, from its formation, through its functional life, and then its eventual end. All of our body cells are formed from mitotic cell division to begin their life, and, at the end of their functional lives, many of our cells undergo division themselves, essentially being reborn as two new daughter cells.
We also identified important "checkpoints" in the cell cycle, to prevent cells from speeding through the cell cycle too rapidly. Many of our cells have functional lives of months to years, and without these checkpoints, they would otherwise just divide rapidly into new cells. As we noted, failure to stop at these cell cycle checkpoints can lead to tumors caused by uncontrolled growth; some tumors can become cancers, invading otherwise normal tissues and causing them to become cancerous as well.
As you know, cancer is one of the primary causes of human mortality. We experience a variety of cancers: some are slow to progress, others very rapid; some are essentially benign while others are very deadly; some are highly invasive and others less so. The diversity if cancers we experience and the diversity of tissues that they strike represents one the of the primary difficulties in treating cancer: there is no single cure, for cancer is very diverse in its many forms.
That's not to say that there aren't standardized treatments. Most hospitals have oncology boards that carefully document each occurrence of cancer, and they typically made treatment decisions based upon consultation among a team of physicians, including oncologists, radiologists, surgeons, and others. Much of their decision-making is based upon care standards that have been developed by national and international cancer agencies, such as our own American Cancer Society, which suggests treatment guidelines for the different forms of cancer. Still, we know all too well that curing cancer is difficult, and sometime impossible. The best one can hope for is to eliminate the cancerous tissue to the point at which is cannot be detected, but that is no promise that every cancerous cell has been removed, nor that it cannot re-appear.
Because of the burden cancer poses to society, there are many federally-funded research groups investigating potential treatments. These include
- genetic methods - to identify and correct cancerous genes, those causing failure of cell cycle checkpoints
- immunological approaches - training our immune cells to hone-in on cancerous cells
- pharmacological methods - using drugs to kill cells which are undergoing cell division
- metabolic methods - starving tumors and cancers of their blood supply or metabolites
Of course, many of the latest treatments combine multiple approaches, such as using immune cells to target delivery of cytotoxic drugs directly to cancer cells.
In the news this week is report of a promising new approach to treating some kinds of cancer, based upon a metabolic starving of cancer cells. Cells that are rapidly dividing (such as those within a tumor or a cancer) are metabolically very demanding, needing large amounts of fuel. Scientists have developed methods to prevent cells from using glutamine (a glucose-like fuel source), to successfully prevent cancer growth. But, earlier formations of this treatment caused widespread side effects, because the cancer cells were not the only ones being starved of fuel.
In this latest test, the scientists successfully "handcuffed" an inactive form of their drug to allow its focal delivery to cancer cells, where it was "unhandcuffed" into an active form by cancer cell enzymes. There it successfully prevented cancer growth. Even better, this new treatment actually improved immune T-cell function, providing an immunological boost to cancer elimination as well.
These initial studies, done in mice, were very promising. While the road from animal studies to human uses is often long and unsure, this could mark the beginnings of a new generation of cancer treatments that are improved in their focused targeting as well as in their effectiveness at cancer elimination.
https://www.sciencemag.org/news/2019/11/revamped-cancer-drug-starves-tumors-mice
We'll talk more about cancer in our upcoming lectures, and I hope that this article will put some of the lecture material into practical context. Cancer touches many families, and does not discriminate by race, class, knowledge, or upbringing. May your generation be the one that finally reduces the impact that it has on our individual and our public health.
Have a great weekend - see you on Monday.
Sincerely,
Dr. Nealen
Sugary Drink Ban Tied to Health Improvements at Medical Center - The New York Times
(originally posted 03 Nov 2019)
Good morning everyone,
Last week I sent you a news report about the prospect of "sugar taxes", extra monetary tax levied against sweetened drinks as a way to reduce their consumption and to (hopefully) induce some improved health in the persons who might normally consume too much sugar in their diets.
The article that I sent you last week considered some of the potential benefits, and potential difficulties, of implementing such taxes. It also described the limited amount of data available thus far, suggesting that it is still too early to know whether these kinds of taxes lead to health improvements.
In this news this week is report of a newly-released study on this very topic. Here, researchers followed the health of a focal group of 200+ people at the University of California-San Fransisco medical school, where a full ban on the sale of sweetened drinks has been in effect. Researchers report improvements in several subject health measures, including reduced waist size, less belly fat, and improved response to insulin. They suggest that these changes were directly a function of reduced sugary drink consumption in these subjects.
https://www.nytimes.com/2019/10/28/well/eat/sugary-drink-soda-ban-health-medical-center.html
Note that this study described subjects under a workplace ban on the sale of sweetened drinks, not those under a "sugar tax". Here, subjects could purchases sweetened drinks elsewhere, or bring them from home, but could not purchase them at their workplace. This is likely to have a larger effect on consumption than a sugar tax itself, but it does suggest that the benefits of lowering the consumption of sweetened drinks is a very worthwhile goal. The available data suggests that most of us consume too much refined sugar (in some form), which suggests that most of us would benefit by reducing our sugar intake. As we have seen many times during the term, our health depends heavily on the choices we make.
Hope that you are enjoying the weekend - see you tomorrow.
Dr. Nealen
(originally posted 03 Nov 2019)
Good morning everyone,
Last week I sent you a news report about the prospect of "sugar taxes", extra monetary tax levied against sweetened drinks as a way to reduce their consumption and to (hopefully) induce some improved health in the persons who might normally consume too much sugar in their diets.
The article that I sent you last week considered some of the potential benefits, and potential difficulties, of implementing such taxes. It also described the limited amount of data available thus far, suggesting that it is still too early to know whether these kinds of taxes lead to health improvements.
In this news this week is report of a newly-released study on this very topic. Here, researchers followed the health of a focal group of 200+ people at the University of California-San Fransisco medical school, where a full ban on the sale of sweetened drinks has been in effect. Researchers report improvements in several subject health measures, including reduced waist size, less belly fat, and improved response to insulin. They suggest that these changes were directly a function of reduced sugary drink consumption in these subjects.
https://www.nytimes.com/2019/10/28/well/eat/sugary-drink-soda-ban-health-medical-center.html
Note that this study described subjects under a workplace ban on the sale of sweetened drinks, not those under a "sugar tax". Here, subjects could purchases sweetened drinks elsewhere, or bring them from home, but could not purchase them at their workplace. This is likely to have a larger effect on consumption than a sugar tax itself, but it does suggest that the benefits of lowering the consumption of sweetened drinks is a very worthwhile goal. The available data suggests that most of us consume too much refined sugar (in some form), which suggests that most of us would benefit by reducing our sugar intake. As we have seen many times during the term, our health depends heavily on the choices we make.
Hope that you are enjoying the weekend - see you tomorrow.
Dr. Nealen
Do Soda Taxes Actually Work? Here's What the Science is Telling Us
(originally posted 24 Oct 2019)
Good evening all,
As I noted in lecture on Wednesday, we remain on-schedule with out lecture chapters, and do not have a chapter scheduled for tomorrow (Friday 25 Oct). So, I would like once again to propose that we do not meet in person for lecture tomorrow, and ask instead that you consider the reading that I am forwarding here.
In our last lecture on the endocrine system, we noted the central role of the pancreas and its hormones in the regulation of blood glucose ("blood sugar") levels. When levels of blood glucose rise (such as when we are absorbing digested sugars into our bloodstream after a meal), the hormone insulin is released by the pancreas. Insulin causes our cells (especially liver and muscle cells) to uptake glucose - that is, to take glucose out of the bloodstream and move it into cells by means of membrane transporters. This allows cells to have glucose available for fuel, and also allows cells to store the excess glucose for later use.
On the flip side, when our blood glucose levels decline (such as when we are several hours past a meal and done absorbing nutrients), other cells in the pancreas release the hormone glucagon, which causes our cells (especially liver and muscle cells) to release some of their stored glucose. Together, the use of the two hormones allows us to maintain a relatively even profile of blood glucose levels.
As we discussed yesterday, when blood sugar levels are not well-controlled, diabetes may result. The primary symptom of diabetes is high (and poorly controlled) blood glucose levels. This causes a number of immediate effects, such as excess urination, thirst, and excessive fat metabolism. Over the long term, high levels of blood glucose are very damaging to our tissues, particularly through scarring of the inner lining of our blood vessels. This can lead to the failure of organs with extensive capillary beds (such as the retina of the eye, and the kidney), and has negative effects on circulation in general, especially in the lower periphery. Persons with uncontrolled blood sugar often suffer poor wound healing (especially of the feet), which can lead to infections and, in some cases, require amputation.
In lecture, we distinguished the two general types of diabetes as well. "Type I" diabetes occurs when our own immune system causes the destruction of the insulin-producing cells of the pancreas. This is classified as an auto-immune disorder, as the disease stems from a problem with the immune system. Type I diabetes is often called "juvenile diabetes", because it is typically first diagnosed in one's youth. It can be treated (usually successfully) with injections of insulin - daily, often multiple times. Insulin pumps can also be used - these are small, battery powered pumps that infuse gradual, small amounts of insulin into a catheter. They are expensive and require maintenance, but are effective solutions for many.
"Type II", or "adult onset diabetes" is more challenging. It tends to appear in people with a combination of risk factors: obesity, poor diet, little exercise. Over time, the cells of their body gradually become resistant to insulin, and stop responding to it. Their pancreas produces normal amounts of insulin, but it is ineffective - blood glucose remains elevated, cells become starved for sugar fuels, and metabolize other fuels (mostly fats). Tissue damage accumulates because of the persistently elevated blood glucose levels. Additional insulin (injections) can help somewhat, but the most effective treatment is improvements in diet and exercise. Some people can almost completely reverse their condition through these lifestyle changes, and nearly everyone can benefit at least somewhat from them.
There is a lot of biology associated with diabetes: its causes, effects, and treatments. There also is a lot of sociology to it as well. Diabetes strikes populations very unevenly, and impacts populations of relatively poorer socioeconomic levels most severely. This is believed to be due to a number of factors, including reduced access to high-quality food, more-restrictive employment and familial responsibilities that limit time to exercise, and less access to good information about health. It has also been suggested that food corporations specifically target these populations with advertising and vendors for "fast food", including soft drinks ("soda", or "pop", depending upon where you were raised).
As a food, soda is of very low quality. It is mostly water, but the other primary ingredients are sugar, and often caffeine. It is also quite acidic, and has quite damaging effects on our teeth. So, why do we buy/drink it? We do so at least in part of because of very successful, and very prominent, advertising, which has allowed some soda companies to develop enough clout that they can contractually deliver soda to schools, hospitals, corporations, and even cities.
Think back to your middle- and high-school education: did soda vending machines exist in your school? Were fountain drinks available over the counter in the cafeteria? For most of us, the answer to these questions is "yes". Do you buy bulk quantities of soda? Do you see others around you who do? Again, for most of us, the answers here are "yes" as well.
In recent years, public health experts have recognized the dangers of over-consumption of soda, and more importantly, the danger of exposure to it in our youth. Too often, adolescents develop a "soda habit", and maintain it into adulthood. This, in combination with other lifestyle choices, has led to skyrocketing rates of juvenile obesity. Even more alarming, "adult onset" diabetes is now diagnosed in adolescents at alarming rates.
So what can be done? Well, the debate rages, because to eliminate soda from communities and diets is not really an option. Soda companies are large, and powerful, and they have an avid user base that wants their products. This is a situation similar to that faced years ago with the tobacco industry: large and powerful corporations, well-paid lobbies, a desirous user base, and mounting evidence of the dangerous health effects of the product. Here, too, numerous solutions were discussed and tried. One of the remedies that seemed to be most effective was to implement larger and larger taxes on tobacco, to the point at which fewer people were willing, or able, to financially support their tobacco habit.
Because of the success of this strategy to reduce tobacco usage, we now live in an era of the "soda tax". The idea here is the same: if a popular consumer product is legal, but unhealthy, tax it in order to reduce the number of people using it, and/or the amounts that they use. This remains a controversial idea. Why should companies producing a legal, desirable product be punished? Is this ethical? Does this not also punish the people that work for them, and their suppliers, accountants, and all of the other people who work in associated jobs? Does this also punish consumers of relatively lower income unfairly, because they would be the ones least likely to be able to afford a price increase?
With soda, too, the application of a tax is more complicated. Tobacco and alcohol are relatively uniform in how they are packaged and purchased, but sugary drinks exist across the spectrum (from soda, to sweetened milk, to orange juice and yogurt). Wait -- aren't milk, orange juice, and yogurt good for us? Well, yes, but less so if they have a lot of added sugar. Should they be taxed less than soda, because they are relatively more healthy? What about sugary cereals and granola bars? What about foods with artificial sweeteners? The lines are less clear in this current health debate.
The news report I am forwarding describes a recent assessment of the effectiveness of "sugar taxes". Dozens of other countries, and multiple large cities in this country, have imposed this tax. They have existed for a relatively short time, so there is much yet to be learned about them. They do appear to cause a drop in soda consumption, but whether that translates into improved health of the population is still to be determined. Not surprisingly, the soda companies have responded aggressively, with a variety of tactics. This battle is far from settled.
http://blogs.discovermagazine.com/crux/2019/10/22/do-soda-taxes-actually-work-heres-what-the-science-is-telling-us/
The next time you are at the grocery store, ask yourself if you are planning to put soda into your cart. And, look around: how many people do? It's common to see people pushing shopping carts with 6-packs of bottled soda (often multiple of them) draped over the edges of the cart. This behavior didn't exist 10 years ago! Have the bottles changed to make this more convenient? Or are we buying more? Our fast food restaurants and convenience stores offer *enormous* fountain drinks - 30, 40, even 50 ounces at a time! Does anyone rally need that much soda at once?
On this, and all of our topics, stay informed. Healthy habits require good information, and wise choices. There is plenty of information available on the health aspects of soda and its social implications. Be wise shoppers and consumers!
And, have a great weekend. See you on Monday for Chapter 17.
Sincerely,
Dr. Nealen
(originally posted 24 Oct 2019)
Good evening all,
As I noted in lecture on Wednesday, we remain on-schedule with out lecture chapters, and do not have a chapter scheduled for tomorrow (Friday 25 Oct). So, I would like once again to propose that we do not meet in person for lecture tomorrow, and ask instead that you consider the reading that I am forwarding here.
In our last lecture on the endocrine system, we noted the central role of the pancreas and its hormones in the regulation of blood glucose ("blood sugar") levels. When levels of blood glucose rise (such as when we are absorbing digested sugars into our bloodstream after a meal), the hormone insulin is released by the pancreas. Insulin causes our cells (especially liver and muscle cells) to uptake glucose - that is, to take glucose out of the bloodstream and move it into cells by means of membrane transporters. This allows cells to have glucose available for fuel, and also allows cells to store the excess glucose for later use.
On the flip side, when our blood glucose levels decline (such as when we are several hours past a meal and done absorbing nutrients), other cells in the pancreas release the hormone glucagon, which causes our cells (especially liver and muscle cells) to release some of their stored glucose. Together, the use of the two hormones allows us to maintain a relatively even profile of blood glucose levels.
As we discussed yesterday, when blood sugar levels are not well-controlled, diabetes may result. The primary symptom of diabetes is high (and poorly controlled) blood glucose levels. This causes a number of immediate effects, such as excess urination, thirst, and excessive fat metabolism. Over the long term, high levels of blood glucose are very damaging to our tissues, particularly through scarring of the inner lining of our blood vessels. This can lead to the failure of organs with extensive capillary beds (such as the retina of the eye, and the kidney), and has negative effects on circulation in general, especially in the lower periphery. Persons with uncontrolled blood sugar often suffer poor wound healing (especially of the feet), which can lead to infections and, in some cases, require amputation.
In lecture, we distinguished the two general types of diabetes as well. "Type I" diabetes occurs when our own immune system causes the destruction of the insulin-producing cells of the pancreas. This is classified as an auto-immune disorder, as the disease stems from a problem with the immune system. Type I diabetes is often called "juvenile diabetes", because it is typically first diagnosed in one's youth. It can be treated (usually successfully) with injections of insulin - daily, often multiple times. Insulin pumps can also be used - these are small, battery powered pumps that infuse gradual, small amounts of insulin into a catheter. They are expensive and require maintenance, but are effective solutions for many.
"Type II", or "adult onset diabetes" is more challenging. It tends to appear in people with a combination of risk factors: obesity, poor diet, little exercise. Over time, the cells of their body gradually become resistant to insulin, and stop responding to it. Their pancreas produces normal amounts of insulin, but it is ineffective - blood glucose remains elevated, cells become starved for sugar fuels, and metabolize other fuels (mostly fats). Tissue damage accumulates because of the persistently elevated blood glucose levels. Additional insulin (injections) can help somewhat, but the most effective treatment is improvements in diet and exercise. Some people can almost completely reverse their condition through these lifestyle changes, and nearly everyone can benefit at least somewhat from them.
There is a lot of biology associated with diabetes: its causes, effects, and treatments. There also is a lot of sociology to it as well. Diabetes strikes populations very unevenly, and impacts populations of relatively poorer socioeconomic levels most severely. This is believed to be due to a number of factors, including reduced access to high-quality food, more-restrictive employment and familial responsibilities that limit time to exercise, and less access to good information about health. It has also been suggested that food corporations specifically target these populations with advertising and vendors for "fast food", including soft drinks ("soda", or "pop", depending upon where you were raised).
As a food, soda is of very low quality. It is mostly water, but the other primary ingredients are sugar, and often caffeine. It is also quite acidic, and has quite damaging effects on our teeth. So, why do we buy/drink it? We do so at least in part of because of very successful, and very prominent, advertising, which has allowed some soda companies to develop enough clout that they can contractually deliver soda to schools, hospitals, corporations, and even cities.
Think back to your middle- and high-school education: did soda vending machines exist in your school? Were fountain drinks available over the counter in the cafeteria? For most of us, the answer to these questions is "yes". Do you buy bulk quantities of soda? Do you see others around you who do? Again, for most of us, the answers here are "yes" as well.
In recent years, public health experts have recognized the dangers of over-consumption of soda, and more importantly, the danger of exposure to it in our youth. Too often, adolescents develop a "soda habit", and maintain it into adulthood. This, in combination with other lifestyle choices, has led to skyrocketing rates of juvenile obesity. Even more alarming, "adult onset" diabetes is now diagnosed in adolescents at alarming rates.
So what can be done? Well, the debate rages, because to eliminate soda from communities and diets is not really an option. Soda companies are large, and powerful, and they have an avid user base that wants their products. This is a situation similar to that faced years ago with the tobacco industry: large and powerful corporations, well-paid lobbies, a desirous user base, and mounting evidence of the dangerous health effects of the product. Here, too, numerous solutions were discussed and tried. One of the remedies that seemed to be most effective was to implement larger and larger taxes on tobacco, to the point at which fewer people were willing, or able, to financially support their tobacco habit.
Because of the success of this strategy to reduce tobacco usage, we now live in an era of the "soda tax". The idea here is the same: if a popular consumer product is legal, but unhealthy, tax it in order to reduce the number of people using it, and/or the amounts that they use. This remains a controversial idea. Why should companies producing a legal, desirable product be punished? Is this ethical? Does this not also punish the people that work for them, and their suppliers, accountants, and all of the other people who work in associated jobs? Does this also punish consumers of relatively lower income unfairly, because they would be the ones least likely to be able to afford a price increase?
With soda, too, the application of a tax is more complicated. Tobacco and alcohol are relatively uniform in how they are packaged and purchased, but sugary drinks exist across the spectrum (from soda, to sweetened milk, to orange juice and yogurt). Wait -- aren't milk, orange juice, and yogurt good for us? Well, yes, but less so if they have a lot of added sugar. Should they be taxed less than soda, because they are relatively more healthy? What about sugary cereals and granola bars? What about foods with artificial sweeteners? The lines are less clear in this current health debate.
The news report I am forwarding describes a recent assessment of the effectiveness of "sugar taxes". Dozens of other countries, and multiple large cities in this country, have imposed this tax. They have existed for a relatively short time, so there is much yet to be learned about them. They do appear to cause a drop in soda consumption, but whether that translates into improved health of the population is still to be determined. Not surprisingly, the soda companies have responded aggressively, with a variety of tactics. This battle is far from settled.
http://blogs.discovermagazine.com/crux/2019/10/22/do-soda-taxes-actually-work-heres-what-the-science-is-telling-us/
The next time you are at the grocery store, ask yourself if you are planning to put soda into your cart. And, look around: how many people do? It's common to see people pushing shopping carts with 6-packs of bottled soda (often multiple of them) draped over the edges of the cart. This behavior didn't exist 10 years ago! Have the bottles changed to make this more convenient? Or are we buying more? Our fast food restaurants and convenience stores offer *enormous* fountain drinks - 30, 40, even 50 ounces at a time! Does anyone rally need that much soda at once?
On this, and all of our topics, stay informed. Healthy habits require good information, and wise choices. There is plenty of information available on the health aspects of soda and its social implications. Be wise shoppers and consumers!
And, have a great weekend. See you on Monday for Chapter 17.
Sincerely,
Dr. Nealen
Testosterone boosts women's athletic performance, study shows | Science | The Guardian
(originally posted 19 Oct 2019)
Good morning all,
During our recent EMG lab, we considered muscle structure/function, and how muscle strength can be improved through enlargement of muscle fibers. We also noted that testosterone can support the development of larger muscles in both men and women. In the news this week is a report confirming that testosterone improves muscle and athletic performance in women, along with news of a strict limit on testosterone in female athletes being imposed by a track-and-field regulatory body.
Testosterone is a potent steroid hormone, produced in abundance by the male gonads (the testes). Testosterone is also found in women. The female gonads (ovaries) do not produce testosterone directly, but do produce several estrogens, which can be converted to testosterone by enzymes (especially in the brain). Both sexes also produce other androgens (male-typical hormones) in the adrenal glands, which also can be converted into testosterone.
So, we tend to think of testosterone as a 'male hormone', but the reality is not so simple. Both women and men have circulating testosterone, although men typically have levels that are 10-30x higher that those found in women. But, here too, our simplistic and convenient categorizations are not always reflected in reality.
While men typically have much more testosterone in circulation than do women, the range of variation in each gender is large. What of women who produce unusually large amounts of testosterone? Will that give them a muscular and a competitive advantage in sporting events? The anecdotal and the experimental evidence say that it will.
It is convenient to think of all persons as being purely binary in terms of their sex, such that all aspects of their sexual make-up (genetic sex, physical sex, physiological sex, gender identity) align to be either purely female or purely male, but the reality is, as always, more complicated. Persons of differential sexual development may not be perfectly aligned in all of their sexual characteristics, causing them to have characteristics which are not purely 100% typical of one gender or another. Apart from the social and physical challenges this poses, how such individuals can be evaluated in regulated sporting events recently has come into question. The most notable case has been that of the South African athlete Caster Semenya, a multi-medal winning foot race champion who has repeatedly been sanctioned because her testosterone levels are higher than the thresholds set for female athletes.
And what of athletes that are making a gender transition? Their testosterone levels are highly variable, and may fall within the male-typical or the female-typical range. Should they be barred from, or limited in, participation in sporting events?
These are important issues, beyond sporting regulation. Most aspects of society long have been male-biased, and it is becoming increasingly apparent that we suffer because of this. In science, it has become very clear that work done largely on male physiology serve females poorly. For decades, the standard experimental models for human physiology have been male mice and rats. Only one gender was used in order to reduce experimental variability. We long have known of differences in the female and male reproductive systems, but we never really appreciated how their influences translate into other systems (including the muscular system). But, now we are learning how surprisingly different male and female physiology outside of reproductive systems can be. And, the fact that this recent study of testosterone supplements in women was one of the first of its kind suggests that we have a lot of catching-up to do:
https://www.theguardian.com/science/2019/oct/15/testosterone-boosts-womens-athletic-performance-study-shows
There is much to be learned about differences in female and male physiology and their implications for our health and well-being, and our scientific community is finally waking up to this fact. How the sporting community deals with the complexities of our physiology is of relatively little importance, perhaps. But the issue of equality in general, in science, health, and society, is one that recent generations have failed to properly address. May your generation be more open, more mindful, and more egalitarian.
Have a great weekend -
Dr. Nealen
(originally posted 19 Oct 2019)
Good morning all,
During our recent EMG lab, we considered muscle structure/function, and how muscle strength can be improved through enlargement of muscle fibers. We also noted that testosterone can support the development of larger muscles in both men and women. In the news this week is a report confirming that testosterone improves muscle and athletic performance in women, along with news of a strict limit on testosterone in female athletes being imposed by a track-and-field regulatory body.
Testosterone is a potent steroid hormone, produced in abundance by the male gonads (the testes). Testosterone is also found in women. The female gonads (ovaries) do not produce testosterone directly, but do produce several estrogens, which can be converted to testosterone by enzymes (especially in the brain). Both sexes also produce other androgens (male-typical hormones) in the adrenal glands, which also can be converted into testosterone.
So, we tend to think of testosterone as a 'male hormone', but the reality is not so simple. Both women and men have circulating testosterone, although men typically have levels that are 10-30x higher that those found in women. But, here too, our simplistic and convenient categorizations are not always reflected in reality.
While men typically have much more testosterone in circulation than do women, the range of variation in each gender is large. What of women who produce unusually large amounts of testosterone? Will that give them a muscular and a competitive advantage in sporting events? The anecdotal and the experimental evidence say that it will.
It is convenient to think of all persons as being purely binary in terms of their sex, such that all aspects of their sexual make-up (genetic sex, physical sex, physiological sex, gender identity) align to be either purely female or purely male, but the reality is, as always, more complicated. Persons of differential sexual development may not be perfectly aligned in all of their sexual characteristics, causing them to have characteristics which are not purely 100% typical of one gender or another. Apart from the social and physical challenges this poses, how such individuals can be evaluated in regulated sporting events recently has come into question. The most notable case has been that of the South African athlete Caster Semenya, a multi-medal winning foot race champion who has repeatedly been sanctioned because her testosterone levels are higher than the thresholds set for female athletes.
And what of athletes that are making a gender transition? Their testosterone levels are highly variable, and may fall within the male-typical or the female-typical range. Should they be barred from, or limited in, participation in sporting events?
These are important issues, beyond sporting regulation. Most aspects of society long have been male-biased, and it is becoming increasingly apparent that we suffer because of this. In science, it has become very clear that work done largely on male physiology serve females poorly. For decades, the standard experimental models for human physiology have been male mice and rats. Only one gender was used in order to reduce experimental variability. We long have known of differences in the female and male reproductive systems, but we never really appreciated how their influences translate into other systems (including the muscular system). But, now we are learning how surprisingly different male and female physiology outside of reproductive systems can be. And, the fact that this recent study of testosterone supplements in women was one of the first of its kind suggests that we have a lot of catching-up to do:
https://www.theguardian.com/science/2019/oct/15/testosterone-boosts-womens-athletic-performance-study-shows
There is much to be learned about differences in female and male physiology and their implications for our health and well-being, and our scientific community is finally waking up to this fact. How the sporting community deals with the complexities of our physiology is of relatively little importance, perhaps. But the issue of equality in general, in science, health, and society, is one that recent generations have failed to properly address. May your generation be more open, more mindful, and more egalitarian.
Have a great weekend -
Dr. Nealen
Heroin Addiction Explained: How Opioids Hijack the Brain
(originally posted 17 Oct 2019)
Good afternoon all,
Now that our second exam is completed, we will spend a bit of time discussing the nervous and endocrine systems as we start into the 3rd unit of our course. These are the two primary regulatory systems in the body, which makes their place in our homeostatic control very important. Accordingly then, when these systems are dysregulated or hijacked, the problems that arise can be very severe.
We do not have a chapter assigned for tomorrow (Friday 18 Oct), so I would like to give you some supplemental reading, instead. You can review this material on your own, so we will not have to meet in person on Friday (tomorrow).
In lecture yesterday, we outlined the cellular basis of the nervous system, and the method by which neurons communicate with each other and their targets at synapses. Synapses are points of communication between cells, but are not actual points of physical contact between cells. The communication is achieved not by direct cell-to-cell transfer of materials, but rather through neurotransmitters, chemical signals that are released from the 'signaling' cell, drift across the synapse space, and bind to receptors on the 'receiving' cell.
If you think back to early in the term about our discussions of how cells can communicate with each other, you will picture that these neurotransmitters can have effects on their target cells by binding to receptors on the cells, and causing some change: perhaps ion channels open or close, ions move in or out of the cell (or stop flowing), or some enzyme is activated that changes the metabolism of the target cell. These changes might have the effect of stimulating the target cell (causing it to perform more of its cellular function), or inhibiting it.
As I pointed out in lecture yesterday, synapses also are the place where most of our drugs (both legal and illegal) influence nervous system function. Our drugs may change the amount of neurotransmitter that is released, or cause it to stay in the synapse for a longer or shorter time. Some drugs block neurotransmitters from binding to their receptors, or artificially activate the receptors even when no neurotransmitter is present. These all are potentially very powerful effects on synaptic function, and thus brain function. If the effects of medications are targeted to specific neural systems (sensory, motor, motivation, reward, or other), they can drastically alter our behavior and our capabilities.
When we quickly reviewed some some common drugs and their effects at the end of lecture yesterday, I noted that heroin is among our most dangerous drugs, for its ability to cause very high levels of dependence (users can't bear to be without the drug) and tolerance (users need successively larger doses to feel the same effect). Heroin is one of the opioid drugs, a class of drugs long known for their ability to relieve pain and provide pleasure/euphoria. This class of drugs includes morphine, long used clinically for pain relief.
Historically, heroin was derived from natural (plant) sources, and humans have been cultivating and using opioids for thousands of years. Poppy plants have long been grown for their opium sap, which can be consumed as-is, or refined into more-potent forms. With the advent of global travel, poppies grown in Afghanistan can produce opium sap, which can be refined into heroin and trafficked for thousands of miles. This wave of heroin across the planet initiated the opioid crisis, decades ago.
More recently, pharmaceutical advances have led to the development of many other opioids: hydrocodone, oxycodone, fentanyl, and others. They are so effective at providing pain relief that they have been heavily marketed, and heavily prescribed. Black-market sourcing and illegal use of synthetic opioids now far outstrips that of heroin, as the pharmaceuticals are typically cheaper, easier to obtain, and preferred by users because they are, in many cases, more potent. Fentanyl, for example, is estimated to be 20x as potent as heroin. Other synthetic opioids may be as much as 500x as potent.
Prescription and illegal use of opioids now has reached a crisis point in our country. One cannot listen to the news without hearing of opioid uses and deaths (even here at IUP). Opioids do target the pleasure and pain centers of the brain, but they also serve as a general depressant of respiratory function. As users become dependent upon and more tolerant of these drugs, they acquire and use them in higher amounts. This puts them more and more at risk of respiratory failure: their brains simply stop signaling enough breathing. This is especially problematic when users consume illegal drugs, for their contents may not be well-regulated. Far too often, users overdose on drugs which are more concentrated, or in higher doses, than expected.
And so, for your reading on this topic, I'm offering here below a link not to a recent news story, but rather to a more comprehensive news report that was issued last Fall. It describes some of the biology and the neuroscience of opioid addiction, but also presents a variety of personal perspectives from addicted individuals. In many ways, addiction can be considered to be a disease, and the viewpoints and anecdotes describing addiction are both powerful and scary.
https://www.nytimes.com/interactive/2018/us/addiction-heroin-opioids.html
This article also includes links to a few other resources on the topic of opioid addiction.
But let us add to this discussion some good news: Because the action of opioids is relatively well-understood, pharmaceutical advances have made available a very effective antidote to opioid overdose. Commonly referred to by its product name (Narcan), naloxone is a substance that binds to opioid receptors, in place of the opioids themselves. But, naloxone does not activate the receptor in the same way as do the opioids; rather, it blocks the receptor from being activated by the opioids.
Naloxone is remarkably effective, and many first responders and emergency personnel now carry it. They find themselves using more frequently than they would like, but there is no doubt that it has saved thousands of lives.
Naloxone is so important in the fight against opioid abuse that the Pennsylvania Department of Health has issued a standing order that allows public citizens to obtain it, if they believe that having Narcan might help them prevent an opioid overdose. If you think that having it would benefit you or those around you, I'd encourage you to consider obtaining it. You can start at the PA Department of Health web site, especially the text pertaining to ACT 139, which described how private citizens might obtain naloxone, through a standing prescription order:
https://www.health.pa.gov/topics/disease/Opioids/Pages/Naloxone.aspx
There also are opioid resources available here at IUP, through IUP's Center for Health and Well-Being:
https://www.iup.edu/chwb/
I can help you navigate these resources, if you like.
I hope that these materials help to put our discussions of brain structure/function and synapses into some context. I'd be happy to provide more material on these topics, if anyone is interested.
Have a great weekend - see you on Monday.
Sincerely,
Dr. Nealen
(originally posted 17 Oct 2019)
Good afternoon all,
Now that our second exam is completed, we will spend a bit of time discussing the nervous and endocrine systems as we start into the 3rd unit of our course. These are the two primary regulatory systems in the body, which makes their place in our homeostatic control very important. Accordingly then, when these systems are dysregulated or hijacked, the problems that arise can be very severe.
We do not have a chapter assigned for tomorrow (Friday 18 Oct), so I would like to give you some supplemental reading, instead. You can review this material on your own, so we will not have to meet in person on Friday (tomorrow).
In lecture yesterday, we outlined the cellular basis of the nervous system, and the method by which neurons communicate with each other and their targets at synapses. Synapses are points of communication between cells, but are not actual points of physical contact between cells. The communication is achieved not by direct cell-to-cell transfer of materials, but rather through neurotransmitters, chemical signals that are released from the 'signaling' cell, drift across the synapse space, and bind to receptors on the 'receiving' cell.
If you think back to early in the term about our discussions of how cells can communicate with each other, you will picture that these neurotransmitters can have effects on their target cells by binding to receptors on the cells, and causing some change: perhaps ion channels open or close, ions move in or out of the cell (or stop flowing), or some enzyme is activated that changes the metabolism of the target cell. These changes might have the effect of stimulating the target cell (causing it to perform more of its cellular function), or inhibiting it.
As I pointed out in lecture yesterday, synapses also are the place where most of our drugs (both legal and illegal) influence nervous system function. Our drugs may change the amount of neurotransmitter that is released, or cause it to stay in the synapse for a longer or shorter time. Some drugs block neurotransmitters from binding to their receptors, or artificially activate the receptors even when no neurotransmitter is present. These all are potentially very powerful effects on synaptic function, and thus brain function. If the effects of medications are targeted to specific neural systems (sensory, motor, motivation, reward, or other), they can drastically alter our behavior and our capabilities.
When we quickly reviewed some some common drugs and their effects at the end of lecture yesterday, I noted that heroin is among our most dangerous drugs, for its ability to cause very high levels of dependence (users can't bear to be without the drug) and tolerance (users need successively larger doses to feel the same effect). Heroin is one of the opioid drugs, a class of drugs long known for their ability to relieve pain and provide pleasure/euphoria. This class of drugs includes morphine, long used clinically for pain relief.
Historically, heroin was derived from natural (plant) sources, and humans have been cultivating and using opioids for thousands of years. Poppy plants have long been grown for their opium sap, which can be consumed as-is, or refined into more-potent forms. With the advent of global travel, poppies grown in Afghanistan can produce opium sap, which can be refined into heroin and trafficked for thousands of miles. This wave of heroin across the planet initiated the opioid crisis, decades ago.
More recently, pharmaceutical advances have led to the development of many other opioids: hydrocodone, oxycodone, fentanyl, and others. They are so effective at providing pain relief that they have been heavily marketed, and heavily prescribed. Black-market sourcing and illegal use of synthetic opioids now far outstrips that of heroin, as the pharmaceuticals are typically cheaper, easier to obtain, and preferred by users because they are, in many cases, more potent. Fentanyl, for example, is estimated to be 20x as potent as heroin. Other synthetic opioids may be as much as 500x as potent.
Prescription and illegal use of opioids now has reached a crisis point in our country. One cannot listen to the news without hearing of opioid uses and deaths (even here at IUP). Opioids do target the pleasure and pain centers of the brain, but they also serve as a general depressant of respiratory function. As users become dependent upon and more tolerant of these drugs, they acquire and use them in higher amounts. This puts them more and more at risk of respiratory failure: their brains simply stop signaling enough breathing. This is especially problematic when users consume illegal drugs, for their contents may not be well-regulated. Far too often, users overdose on drugs which are more concentrated, or in higher doses, than expected.
And so, for your reading on this topic, I'm offering here below a link not to a recent news story, but rather to a more comprehensive news report that was issued last Fall. It describes some of the biology and the neuroscience of opioid addiction, but also presents a variety of personal perspectives from addicted individuals. In many ways, addiction can be considered to be a disease, and the viewpoints and anecdotes describing addiction are both powerful and scary.
https://www.nytimes.com/interactive/2018/us/addiction-heroin-opioids.html
This article also includes links to a few other resources on the topic of opioid addiction.
But let us add to this discussion some good news: Because the action of opioids is relatively well-understood, pharmaceutical advances have made available a very effective antidote to opioid overdose. Commonly referred to by its product name (Narcan), naloxone is a substance that binds to opioid receptors, in place of the opioids themselves. But, naloxone does not activate the receptor in the same way as do the opioids; rather, it blocks the receptor from being activated by the opioids.
Naloxone is remarkably effective, and many first responders and emergency personnel now carry it. They find themselves using more frequently than they would like, but there is no doubt that it has saved thousands of lives.
Naloxone is so important in the fight against opioid abuse that the Pennsylvania Department of Health has issued a standing order that allows public citizens to obtain it, if they believe that having Narcan might help them prevent an opioid overdose. If you think that having it would benefit you or those around you, I'd encourage you to consider obtaining it. You can start at the PA Department of Health web site, especially the text pertaining to ACT 139, which described how private citizens might obtain naloxone, through a standing prescription order:
https://www.health.pa.gov/topics/disease/Opioids/Pages/Naloxone.aspx
There also are opioid resources available here at IUP, through IUP's Center for Health and Well-Being:
https://www.iup.edu/chwb/
I can help you navigate these resources, if you like.
I hope that these materials help to put our discussions of brain structure/function and synapses into some context. I'd be happy to provide more material on these topics, if anyone is interested.
Have a great weekend - see you on Monday.
Sincerely,
Dr. Nealen
Nobel Prize for Medicine jointly awarded to William Kaelin Jr, Sir Peter Ratcliffe and Gregg Semenza - CNN
(originally posted 12 Oct 2019)
Good morning all,
In recent weeks we have considered the role of the circulatory and respiratory systems in collecting and delivering oxygen to our tissues, and just last week I sent you a long article about altitude-induced hypoxia and the physiological challenges that it stimulates. We've also discussed the kidney hormone EPO, and its role in stimulating the production of RBCs.
Fresh on the heels of those discussions and reading, this week's science news included the awarding of this year's Nobel Prize in Medicine, to a group of three researchers who study this very phenomenon, the physiological responses to oxygen. Their work is crucial to an understanding of how cells adapt to changing oxygen levels.
https://www.cnn.com/2019/10/07/health/nobel-prize-for-medicine-2019-intl/index.html
Nobel Prizes in science fields are awarded to researchers who have long, established careers and who have made discoveries that defined their fields. This year's winners are no exception - these scientists are well-established and highly respected. And, not surprisingly, they are still active. They also are likely to follow another tradition in that they most likely will use the award not to enrich themselves personally, but to support the work of their research groups. It's a great example of the selflessness that drives much of science: exploration and discovery for the greater good.
There are plenty of other news stories on these awards, including
https://www.sciencemag.org/news/2019/10/medicine-nobel-honors-work-cellular-system-sense-oxygen-levels?utm_campaign=news_weekly_2019-10-11&et_rid=17390186&et_cid=3026386
https://www.the-scientist.com/news-opinion/cells-oxygen-sensing-discovery-earns-nobel-prize-66538
Breakthroughs in science normally come after long, hard work, built from many small steps of progress - and informed by many failed experiments, a lot of trial-and-error, and requiring much patience. One prize winner (of years past) said that 'if I have seen further than others, it is only because I have stood on the shoulders of those who came before me'. They say that 'no man is an island', and in science that is certainly true - modern science is a highly collaborative venture, and today's advances are built upon the progress of earlier investigators.
When you contribute to a project, no matter how small or insignificant your part may seem, it's important to remember that it adds to our collective knowledge and capability. Who knows? Future Nobel Prizes may depend on you!
Have a great weekend -
Dr. Nealen
(originally posted 12 Oct 2019)
Good morning all,
In recent weeks we have considered the role of the circulatory and respiratory systems in collecting and delivering oxygen to our tissues, and just last week I sent you a long article about altitude-induced hypoxia and the physiological challenges that it stimulates. We've also discussed the kidney hormone EPO, and its role in stimulating the production of RBCs.
Fresh on the heels of those discussions and reading, this week's science news included the awarding of this year's Nobel Prize in Medicine, to a group of three researchers who study this very phenomenon, the physiological responses to oxygen. Their work is crucial to an understanding of how cells adapt to changing oxygen levels.
https://www.cnn.com/2019/10/07/health/nobel-prize-for-medicine-2019-intl/index.html
Nobel Prizes in science fields are awarded to researchers who have long, established careers and who have made discoveries that defined their fields. This year's winners are no exception - these scientists are well-established and highly respected. And, not surprisingly, they are still active. They also are likely to follow another tradition in that they most likely will use the award not to enrich themselves personally, but to support the work of their research groups. It's a great example of the selflessness that drives much of science: exploration and discovery for the greater good.
There are plenty of other news stories on these awards, including
https://www.sciencemag.org/news/2019/10/medicine-nobel-honors-work-cellular-system-sense-oxygen-levels?utm_campaign=news_weekly_2019-10-11&et_rid=17390186&et_cid=3026386
https://www.the-scientist.com/news-opinion/cells-oxygen-sensing-discovery-earns-nobel-prize-66538
Breakthroughs in science normally come after long, hard work, built from many small steps of progress - and informed by many failed experiments, a lot of trial-and-error, and requiring much patience. One prize winner (of years past) said that 'if I have seen further than others, it is only because I have stood on the shoulders of those who came before me'. They say that 'no man is an island', and in science that is certainly true - modern science is a highly collaborative venture, and today's advances are built upon the progress of earlier investigators.
When you contribute to a project, no matter how small or insignificant your part may seem, it's important to remember that it adds to our collective knowledge and capability. Who knows? Future Nobel Prizes may depend on you!
Have a great weekend -
Dr. Nealen
Hypoxia city
(originally posted 03 Oct 2019)
Good evening all,
As we remain caught-up on our lecture schedule, we do not need to meet in person on Friday (04 Oct) for lecture. Instead, I'd like to you to consider a recent science news article that bears on our lecture material.
In recent weeks, we have considered the properties of our blood, its red blood cells and hemoglobin, as well as the ways in which the circulatory and respiratory systems interact to deliver oxygen to our tissues. We've also described how erythropoietin (EPO, a hormone released from the kidneys in response to low blood oxygen levels) can stimulate the production of more RBCs.
The article I am sending you considers these same phenomena in a human population that lives (but not thrives) in perhaps the highest-elevation city in the world, La Rinconada, Peru. La Rinconada sits at an elevation of 5,100 m (more than 16,500 ft) above sea level, and has a regular population of >50,000 at this very high altitude, there to work in gold mines.
The air at this elevation contains only half as much oxygen as the air at sea level. Persons not accustomed to living at high altitude can become very ill (sometimes fatally) at elevations above 9,000 ft. To give you an idea of how high in the Andes this city is, consider that 'mountain climbing' here is the US is typically considered to be very technical above 12,000 ft in elevation, and not for amateurs. At La Rinconada, people may spend their entire lives above 16,000 ft in elevation.
The physiological challenges of life at this altitude are many and severe. The low oxygen levels stimulate extremely high levels of RBCs and hemoglobin, as much as 3x those considered to be normal. This, in turn, causes blood viscosity to rise dramatically, which causes abnormally high blood pressures. These elevated blood pressures place extra strain on the heart, causing it to enlarge, often dramatically. Despite these adjustments, many suffer from chronic hypoxia, termed 'chronic mountain sickness', or CMS. Blue-ish skin, fatigue, and low endurance all are common symptoms of CMS, and all stem from low levels of blood oxygen.
Curiously, populations long adapted to life at high altitudes (including some populations in these South American Andes mountains, and others in the Himalayas of Southern Asia) seem to have evolved at least some protections against chronic hypoxia and the challenges it poses. This suggests that there may be genetic tools that can be put to use in helping others who suffer from hypoxia not because of altitude, but because of diseases related to cardiac or respiratory function.
This article describes one team of physiologists and their efforts to assess human physiology and health at this altitude. Their initial focus was on CMS and body responses to it, but they quickly became caught-up in the socio-economic plight of the people there - life is brutal for the residents of this city, and the researchers felt, in many ways, helpless to help them. They certainly could not improve the economic status of the town's residents, nor could they offer a cure for CMS. There, as in many parts of the world (including our own country), the working class are too easily exploited, too easily marginalized. Lack of access to basic health care is often one of the first signs of a population that is short of options and resources. When that combines with dangerous forms of employment for the un- or under-educated, health issues rise and life expectancy falls.
https://vis.sciencemag.org/hypoxia-city/
There is a companion podcast for this article as well:
http://traffic.libsyn.com/sciencemag/SciencePodcast_190913.mp3
As you review these materials, I'd like you to think about the basic physiological mechanisms at play: how low blood oxygen levels can stimulate RBC responses, and, in turn, how these can contribute to blood pressure, which itself can trigger responses (remember ANF, when blood pressure rises?). Keeping ourselves in homeostatic conditions is complex even under typical environmental conditions; life under extreme conditions only amplifies the challenge.
I hope that you enjoy this article, and I hope that you enjoy the Homecoming weekend. Please be safe, and I will see you on Monday.
Sincerely,
Dr. Nealen
(originally posted 03 Oct 2019)
Good evening all,
As we remain caught-up on our lecture schedule, we do not need to meet in person on Friday (04 Oct) for lecture. Instead, I'd like to you to consider a recent science news article that bears on our lecture material.
In recent weeks, we have considered the properties of our blood, its red blood cells and hemoglobin, as well as the ways in which the circulatory and respiratory systems interact to deliver oxygen to our tissues. We've also described how erythropoietin (EPO, a hormone released from the kidneys in response to low blood oxygen levels) can stimulate the production of more RBCs.
The article I am sending you considers these same phenomena in a human population that lives (but not thrives) in perhaps the highest-elevation city in the world, La Rinconada, Peru. La Rinconada sits at an elevation of 5,100 m (more than 16,500 ft) above sea level, and has a regular population of >50,000 at this very high altitude, there to work in gold mines.
The air at this elevation contains only half as much oxygen as the air at sea level. Persons not accustomed to living at high altitude can become very ill (sometimes fatally) at elevations above 9,000 ft. To give you an idea of how high in the Andes this city is, consider that 'mountain climbing' here is the US is typically considered to be very technical above 12,000 ft in elevation, and not for amateurs. At La Rinconada, people may spend their entire lives above 16,000 ft in elevation.
The physiological challenges of life at this altitude are many and severe. The low oxygen levels stimulate extremely high levels of RBCs and hemoglobin, as much as 3x those considered to be normal. This, in turn, causes blood viscosity to rise dramatically, which causes abnormally high blood pressures. These elevated blood pressures place extra strain on the heart, causing it to enlarge, often dramatically. Despite these adjustments, many suffer from chronic hypoxia, termed 'chronic mountain sickness', or CMS. Blue-ish skin, fatigue, and low endurance all are common symptoms of CMS, and all stem from low levels of blood oxygen.
Curiously, populations long adapted to life at high altitudes (including some populations in these South American Andes mountains, and others in the Himalayas of Southern Asia) seem to have evolved at least some protections against chronic hypoxia and the challenges it poses. This suggests that there may be genetic tools that can be put to use in helping others who suffer from hypoxia not because of altitude, but because of diseases related to cardiac or respiratory function.
This article describes one team of physiologists and their efforts to assess human physiology and health at this altitude. Their initial focus was on CMS and body responses to it, but they quickly became caught-up in the socio-economic plight of the people there - life is brutal for the residents of this city, and the researchers felt, in many ways, helpless to help them. They certainly could not improve the economic status of the town's residents, nor could they offer a cure for CMS. There, as in many parts of the world (including our own country), the working class are too easily exploited, too easily marginalized. Lack of access to basic health care is often one of the first signs of a population that is short of options and resources. When that combines with dangerous forms of employment for the un- or under-educated, health issues rise and life expectancy falls.
https://vis.sciencemag.org/hypoxia-city/
There is a companion podcast for this article as well:
http://traffic.libsyn.com/sciencemag/SciencePodcast_190913.mp3
As you review these materials, I'd like you to think about the basic physiological mechanisms at play: how low blood oxygen levels can stimulate RBC responses, and, in turn, how these can contribute to blood pressure, which itself can trigger responses (remember ANF, when blood pressure rises?). Keeping ourselves in homeostatic conditions is complex even under typical environmental conditions; life under extreme conditions only amplifies the challenge.
I hope that you enjoy this article, and I hope that you enjoy the Homecoming weekend. Please be safe, and I will see you on Monday.
Sincerely,
Dr. Nealen
Results of our vaping survey
(originally posted 01 Oct 2019)
Good morning all,
The results of our vaping survey are in!
We had 93 responses in total.
Almost exactly 2/3 (61/93) respondents said that they do not vape.
Almost exactly 1/3 (32/93) respondents reported that they did vape at least one per week.
Those respondents who did not vape rated its danger as 8.1 out of 10.
Those who do vape rated its pleasurability as 6/10, and its danger as 7.3/10.
(interesting that users ranked the pleasurability lower than the danger, isn't it?)
Those who vape do so an average of 12x per week (range:1-100 times per week).
17/31 (42%) of those who vape do check the source/ingredients, while the majority (17/31, 55%) do not.
The vaping materials used (and the number of people who reported using them) are
don't know 1
Juul 2
mint 3
nicotine 3
blueberry 1
tobacco 12
other 12
These findings reflect much of what is reported in the recent news:
- vaping is very popular among college-age students
- additives or alternatives to tobacco are prominently used
- users pay relatively little attention to the ingredients or sourcing of vaping products.
These are dangerous trends! That one can directly and intentionally infuse nicotine is especially worrisome, as is the fact that users do not know with great confidence the source or identify of the other compounds that are inhaling. Our lungs are designed for exposure to atmospheric gases only - introducing any other compounds is potentially quite risky.
We will continue to discuss this topic, and I will continue to pass along more information. Education and effort are the keys to behavioral change - with any luck, we can increase awareness of the dangers of vaping and reduce its prevalence. The numbers of vaping-associated cases of severe respiratory distress and mortality continue to climb - please be aware of the dangers, and use that knowledge to make good choices about your health.
https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html
Sincerely,
Dr. Nealen
(originally posted 01 Oct 2019)
Good morning all,
The results of our vaping survey are in!
We had 93 responses in total.
Almost exactly 2/3 (61/93) respondents said that they do not vape.
Almost exactly 1/3 (32/93) respondents reported that they did vape at least one per week.
Those respondents who did not vape rated its danger as 8.1 out of 10.
Those who do vape rated its pleasurability as 6/10, and its danger as 7.3/10.
(interesting that users ranked the pleasurability lower than the danger, isn't it?)
Those who vape do so an average of 12x per week (range:1-100 times per week).
17/31 (42%) of those who vape do check the source/ingredients, while the majority (17/31, 55%) do not.
The vaping materials used (and the number of people who reported using them) are
don't know 1
Juul 2
mint 3
nicotine 3
blueberry 1
tobacco 12
other 12
These findings reflect much of what is reported in the recent news:
- vaping is very popular among college-age students
- additives or alternatives to tobacco are prominently used
- users pay relatively little attention to the ingredients or sourcing of vaping products.
These are dangerous trends! That one can directly and intentionally infuse nicotine is especially worrisome, as is the fact that users do not know with great confidence the source or identify of the other compounds that are inhaling. Our lungs are designed for exposure to atmospheric gases only - introducing any other compounds is potentially quite risky.
We will continue to discuss this topic, and I will continue to pass along more information. Education and effort are the keys to behavioral change - with any luck, we can increase awareness of the dangers of vaping and reduce its prevalence. The numbers of vaping-associated cases of severe respiratory distress and mortality continue to climb - please be aware of the dangers, and use that knowledge to make good choices about your health.
https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html
Sincerely,
Dr. Nealen
A numbing medicine turned a woman's blood blue - CNN
(originally posted 21 Sep 2019)
Good morning all,
We recently described human blood in lecture, noting that it is red in color (of course!), and that its color comes from the hemoglobin pigment inside of our red blood cells.
How about a person whose whole blood is blue?
In the news this week is a report about a woman who used excessive amounts of a common over-the-counter analgesic (benzocaine) which rendered her hemoglobin blue in color:
https://www.cnn.com/2019/09/19/health/blue-blood-trnd/index.html
Persons of low blood oxygen levels are considered to be 'cyanotic', and often have a pale or bluish cast to their skin. If their hemoglobin has been poisoned, it can impair oxygen transport/delivery, at worst, to a fatal degree.
In this case, the blue color was not physiologically problematic. This woman's blood was still relatively high in oxygen content, but contained more cyanomethemoglobin (which causes the blue color) than is normal (few percent). Luckily for this woman, her problem was cosmetic only, and the antidote (ironically, doses of methylene blue) was both simple and effective.
Interestingly, blue blood is perfectly normal in crustaceans (such as crabs and lobsters), because they employ hemocyanin (rather than hemoglobin) for oxygen transport. Their blood is of such great medical utility for testing of toxins and contamination that a large (and controversial) industry is devoted to its collection:
https://www.theatlantic.com/science/archive/2018/05/blood-in-the-water/559229/
And, there is a known genetic disorder than causes cyanosis to run in (a small number of) families, including the famous 'blue Fugates of Kentucky':
https://www.iflscience.com/health-and-medicine/the-science-behind-the-mysterious-blue-people-of-kentucky/all/
So, the next time you hear the term "blue bloods", you might wonder if it is genetic, pharmaceutical, or crustacean in its basis...
Have a great weekend -
Dr. Nealen
(originally posted 21 Sep 2019)
Good morning all,
We recently described human blood in lecture, noting that it is red in color (of course!), and that its color comes from the hemoglobin pigment inside of our red blood cells.
How about a person whose whole blood is blue?
In the news this week is a report about a woman who used excessive amounts of a common over-the-counter analgesic (benzocaine) which rendered her hemoglobin blue in color:
https://www.cnn.com/2019/09/19/health/blue-blood-trnd/index.html
Persons of low blood oxygen levels are considered to be 'cyanotic', and often have a pale or bluish cast to their skin. If their hemoglobin has been poisoned, it can impair oxygen transport/delivery, at worst, to a fatal degree.
In this case, the blue color was not physiologically problematic. This woman's blood was still relatively high in oxygen content, but contained more cyanomethemoglobin (which causes the blue color) than is normal (few percent). Luckily for this woman, her problem was cosmetic only, and the antidote (ironically, doses of methylene blue) was both simple and effective.
Interestingly, blue blood is perfectly normal in crustaceans (such as crabs and lobsters), because they employ hemocyanin (rather than hemoglobin) for oxygen transport. Their blood is of such great medical utility for testing of toxins and contamination that a large (and controversial) industry is devoted to its collection:
https://www.theatlantic.com/science/archive/2018/05/blood-in-the-water/559229/
And, there is a known genetic disorder than causes cyanosis to run in (a small number of) families, including the famous 'blue Fugates of Kentucky':
https://www.iflscience.com/health-and-medicine/the-science-behind-the-mysterious-blue-people-of-kentucky/all/
So, the next time you hear the term "blue bloods", you might wonder if it is genetic, pharmaceutical, or crustacean in its basis...
Have a great weekend -
Dr. Nealen
Your Environment Is Cleaner. Your Immune System Has Never Been So Unprepared. - The New York Times
(originally posted 19 Sep 2019)
Good evening everyone,
At the end of this week we find ourselves in the midst of a discussion of immune function, first with our lecture yesterday on the immune system (Chapter 7), to be followed by our next lecture on infectious disease (Chapter 8), scheduled for next Monday.
Recall that for tomorrow's class (Friday 20 Sept), we will not meet in person. Instead, I'd like you to read/digest a news article on a current and very relevant immune topic, that of environmental exposure to antigens.
For much of the history of our species, human life and society was based around agriculture, including exposure to domesticated animals. In the last hundred years, of course, that has changed for many, as populations became more urban. During this same period, the use of cleansing and sanitizing products in the household has increased dramatically, culminating recently in the explosion of "anti-bacterial" products, such as soaps, wipes, and tissues.
Most immunologists believe that we have taken cleanliness a bit too far. According to the "hygiene hypothesis", natural exposure to antigens keeps the immune system primed for action, and enables it to make robust responses to actual disease agents. In our ultra-clean worlds, however, many (especially the young children of cleaning-obsessed parents) are coming into contact with fewer and fewer natural antigens, and increasingly their immune systems are ill-equipped to respond to them when they do, leading to a rash (no pun intended) of allergies, sensitivities, or, at worst, autoimmune disorders.
This article explores the "hygiene hypothesis" and some of its implications. As you go through it, I'd like you to consider a few key questions:
- what happens to our immune system when we are exposed to naturally-occurring antigens?
- why should exposure to non disease-causing antigens enable us to better respond to more serious antigens?
- do you personally use anti-bacterial products in your household?
- does this article make you want to reconsider their use, in any way?
https://www.nytimes.com/2019/03/12/health/immune-system-allergies.html?searchResultPosition=19
Our immune system is wonderfully complicated and powerful, but some think that our social behaviors have evolved faster than is good for it. Perhaps a nice walk outdoors, a swim in a lake, or a picnic in the grass is just what we need...
#ReturnToNature
Have a great weekend - see you on Monday.
Dr. Nealen
(originally posted 19 Sep 2019)
Good evening everyone,
At the end of this week we find ourselves in the midst of a discussion of immune function, first with our lecture yesterday on the immune system (Chapter 7), to be followed by our next lecture on infectious disease (Chapter 8), scheduled for next Monday.
Recall that for tomorrow's class (Friday 20 Sept), we will not meet in person. Instead, I'd like you to read/digest a news article on a current and very relevant immune topic, that of environmental exposure to antigens.
For much of the history of our species, human life and society was based around agriculture, including exposure to domesticated animals. In the last hundred years, of course, that has changed for many, as populations became more urban. During this same period, the use of cleansing and sanitizing products in the household has increased dramatically, culminating recently in the explosion of "anti-bacterial" products, such as soaps, wipes, and tissues.
Most immunologists believe that we have taken cleanliness a bit too far. According to the "hygiene hypothesis", natural exposure to antigens keeps the immune system primed for action, and enables it to make robust responses to actual disease agents. In our ultra-clean worlds, however, many (especially the young children of cleaning-obsessed parents) are coming into contact with fewer and fewer natural antigens, and increasingly their immune systems are ill-equipped to respond to them when they do, leading to a rash (no pun intended) of allergies, sensitivities, or, at worst, autoimmune disorders.
This article explores the "hygiene hypothesis" and some of its implications. As you go through it, I'd like you to consider a few key questions:
- what happens to our immune system when we are exposed to naturally-occurring antigens?
- why should exposure to non disease-causing antigens enable us to better respond to more serious antigens?
- do you personally use anti-bacterial products in your household?
- does this article make you want to reconsider their use, in any way?
https://www.nytimes.com/2019/03/12/health/immune-system-allergies.html?searchResultPosition=19
Our immune system is wonderfully complicated and powerful, but some think that our social behaviors have evolved faster than is good for it. Perhaps a nice walk outdoors, a swim in a lake, or a picnic in the grass is just what we need...
#ReturnToNature
Have a great weekend - see you on Monday.
Dr. Nealen
Artists who paint with their feet have ‘toe maps’ in their brains | Science News
(originally posted 14 Sep 2019)
Good morning everyone,
We soon will be discussing the brain and nervous system, and our discussions will include the concept of 'body maps' in the brain. These represent areas of the brain that contain neurons that are spatially arranged to correspond to particular areas of our bodies (like our fingers and faces). We all have them, and they make some of the computations required by our brain a bit easier. Specialized training (such as the playing of a musical instrument) can modify these maps, making them (in some case) larger and more sensitive.
In the science news this week is a report about these brain maps, but in an unusual way. This news describes brain maps that represent the fine motor skills one develops as a painter, but with a catch: these are painters who use their feet, rather than their hands. In these subjects, the 'brain maps' for their feet have been come elaborated, much like what happens to the brain maps for fingers when highly trained to perform a skill like a painting.
This story reminds us of a number of important features about the brain: even in adults, much of the brain is 'plastic', or modifiable - that is the secret to our ability to learn new things. This story also demonstrates the old saying the 'nature abhors a vacuum' - if part of the brain is not being used a its normal task, in some cases that task can be shifted elsewhere, and parts of the the brain 'reassigned' (to some degree) to new responsibilities. This flexibility is also a hallmark of our brains, and is an important one, for it contributes to recovery from brain injuries, like stroke. When areas of brain tissue are damaged, in some cases nearby areas can be trained to take over those functions that are no longer being served.
So, even if you find that painting is not something you are good at (as I have), don't despair! You have plenty of brain tissue ready and waiting for your hidden talents to emerge...
https://www.sciencenews.org/article/artists-paint-feet-toe-maps-brain
Have a great weekend -
Dr. Nealen
(originally posted 14 Sep 2019)
Good morning everyone,
We soon will be discussing the brain and nervous system, and our discussions will include the concept of 'body maps' in the brain. These represent areas of the brain that contain neurons that are spatially arranged to correspond to particular areas of our bodies (like our fingers and faces). We all have them, and they make some of the computations required by our brain a bit easier. Specialized training (such as the playing of a musical instrument) can modify these maps, making them (in some case) larger and more sensitive.
In the science news this week is a report about these brain maps, but in an unusual way. This news describes brain maps that represent the fine motor skills one develops as a painter, but with a catch: these are painters who use their feet, rather than their hands. In these subjects, the 'brain maps' for their feet have been come elaborated, much like what happens to the brain maps for fingers when highly trained to perform a skill like a painting.
This story reminds us of a number of important features about the brain: even in adults, much of the brain is 'plastic', or modifiable - that is the secret to our ability to learn new things. This story also demonstrates the old saying the 'nature abhors a vacuum' - if part of the brain is not being used a its normal task, in some cases that task can be shifted elsewhere, and parts of the the brain 'reassigned' (to some degree) to new responsibilities. This flexibility is also a hallmark of our brains, and is an important one, for it contributes to recovery from brain injuries, like stroke. When areas of brain tissue are damaged, in some cases nearby areas can be trained to take over those functions that are no longer being served.
So, even if you find that painting is not something you are good at (as I have), don't despair! You have plenty of brain tissue ready and waiting for your hidden talents to emerge...
https://www.sciencenews.org/article/artists-paint-feet-toe-maps-brain
Have a great weekend -
Dr. Nealen
Vaping lung damage: What we know about the mysterious illnesses
(originally posted 09 Sep 2019)
Good morning all,
As a follow-up to the news article I last sent, here are a couple of updates on this developing story:
Severe illness and unexplained deaths associated with vaping have continued to occur, and, while no definitive cause has been identified, the majority of cases seem to be linked to the inhalation of vaping substances that are coating or irritating the lining of the lungs, preventing proper gas exchange. Vaping materials often have additives, such as flavorings or oils, that are the prime target. A number of persons suffering respiratory distress after vaping seem to have oils lining their lung surface. As one researcher put it, 'The lungs are designed to encounter gases only. Inhalation of other substances is inherently risky'.
https://www.nytimes.com/2019/09/07/health/vaping-lung-illness.html
https://www.washingtonpost.com/health/2019/09/07/what-we-know-about-mysterious-vaping-linked-illnesses-deaths/?tid=pm_national_pop
I understand that vaping is quite popular, and I worry (a lot) about how dangerous it is. It is trendy and new, but not well regulated, and too recent to have been well studied. I suspect there will be much more news on this topic, and likely soon many more regulations about what can or cannot be included in vaping materials. I hope that you do not vape - but if you choose to do so, please be informed, for your own safety.
Sincerely,
Dr. Nealen
(originally posted 09 Sep 2019)
Good morning all,
As a follow-up to the news article I last sent, here are a couple of updates on this developing story:
Severe illness and unexplained deaths associated with vaping have continued to occur, and, while no definitive cause has been identified, the majority of cases seem to be linked to the inhalation of vaping substances that are coating or irritating the lining of the lungs, preventing proper gas exchange. Vaping materials often have additives, such as flavorings or oils, that are the prime target. A number of persons suffering respiratory distress after vaping seem to have oils lining their lung surface. As one researcher put it, 'The lungs are designed to encounter gases only. Inhalation of other substances is inherently risky'.
https://www.nytimes.com/2019/09/07/health/vaping-lung-illness.html
https://www.washingtonpost.com/health/2019/09/07/what-we-know-about-mysterious-vaping-linked-illnesses-deaths/?tid=pm_national_pop
I understand that vaping is quite popular, and I worry (a lot) about how dangerous it is. It is trendy and new, but not well regulated, and too recent to have been well studied. I suspect there will be much more news on this topic, and likely soon many more regulations about what can or cannot be included in vaping materials. I hope that you do not vape - but if you choose to do so, please be informed, for your own safety.
Sincerely,
Dr. Nealen
First Death in a Spate of Vaping Sicknesses Reported by Health Officials - The New York Times
(originally posted 29 Aug 2019)
Good evening all,
As I mentioned in lecture on Wednesday, we are still on track schedule-wise, and do not have a chapter planned for Friday of this week. Thus, let's not meet in person for class tomorrow. Instead, I'm passing along (below) a link to a recent news article that I would like you to read, about some of the dangers associated with vaping, a topic that is certainly of the latest health issues of concern. As a former smoker, I know first-hand the 'rush' associated with nicotine; as a physiologist, I know too well the dangers associated with inhaled substances. To me, vaping seems to present dangerous levels of both.
I will occasionally pass along science and health news articles of this type during the semester. My purpose in doing so is to help you to become more aware of topics at the interface of biology and society, and also to help you assess how you obtain your science and health news.
Those of us working in science obtain our scientific news, quite often, directly from the original sources: the people conducting the studies and reporting the results. They publish their findings in science journals, or present them at conferences.
Most people do not obtain science news directly, but hear news via secondary sources, such as news releases from scientific organizations, or news stories from the major news outlets. These secondary reports often are then carried by tertiary outlets (smaller/other reporting sources, including news aggregators and media feeds).
Along the way from source to audience, science news is normally distilled (a lot) - much of the detail is excluded or simplified, and the reports often are boiled-down to singular take-home messages, which may (or may not) be good representations of the original work.
When you browse the links that I will forward, or when you access science and health news on your own, I'd encourage you to delve a little bit deeper into them, to read more than just the summaries, and to follow links back to original sources when possible. I'd also encourage you to think a little about the translation of news from source to consumer, and the reputability of the news outlets that you use.
You will not be formally tested on any of the material in the news stories that I will send you, but I do hope that the material in them makes its way into our conversations.
This first link is from the New York Times, which provides one of the best (e.g., best funded and most reliable) secondary sources of science and health news. They do limit access to only a handful of free articles each month, so I will use them sparingly.
https://www.nytimes.com/2019/08/23/health/vaping-death-cdc.html
Here's wishing you all a safe and enjoyable Labor Day weekend - see you next week.
Sincerely,
Dr. Nealen
(originally posted 29 Aug 2019)
Good evening all,
As I mentioned in lecture on Wednesday, we are still on track schedule-wise, and do not have a chapter planned for Friday of this week. Thus, let's not meet in person for class tomorrow. Instead, I'm passing along (below) a link to a recent news article that I would like you to read, about some of the dangers associated with vaping, a topic that is certainly of the latest health issues of concern. As a former smoker, I know first-hand the 'rush' associated with nicotine; as a physiologist, I know too well the dangers associated with inhaled substances. To me, vaping seems to present dangerous levels of both.
I will occasionally pass along science and health news articles of this type during the semester. My purpose in doing so is to help you to become more aware of topics at the interface of biology and society, and also to help you assess how you obtain your science and health news.
Those of us working in science obtain our scientific news, quite often, directly from the original sources: the people conducting the studies and reporting the results. They publish their findings in science journals, or present them at conferences.
Most people do not obtain science news directly, but hear news via secondary sources, such as news releases from scientific organizations, or news stories from the major news outlets. These secondary reports often are then carried by tertiary outlets (smaller/other reporting sources, including news aggregators and media feeds).
Along the way from source to audience, science news is normally distilled (a lot) - much of the detail is excluded or simplified, and the reports often are boiled-down to singular take-home messages, which may (or may not) be good representations of the original work.
When you browse the links that I will forward, or when you access science and health news on your own, I'd encourage you to delve a little bit deeper into them, to read more than just the summaries, and to follow links back to original sources when possible. I'd also encourage you to think a little about the translation of news from source to consumer, and the reputability of the news outlets that you use.
You will not be formally tested on any of the material in the news stories that I will send you, but I do hope that the material in them makes its way into our conversations.
This first link is from the New York Times, which provides one of the best (e.g., best funded and most reliable) secondary sources of science and health news. They do limit access to only a handful of free articles each month, so I will use them sparingly.
https://www.nytimes.com/2019/08/23/health/vaping-death-cdc.html
Here's wishing you all a safe and enjoyable Labor Day weekend - see you next week.
Sincerely,
Dr. Nealen
Does Testosterone Really Give Caster Semenya an Edge on the Track? - The New York Times
(originally posted 04 May 2019)
Good morning all,
As our term comes to a close, I'll use my last news message to send along the latest news from on ongoing story in exercise physiology that raises interesting, and difficult, questions about sex differences in physiology and the regulation of sporting events.
As we have described in class, both males and females have circulating testosterone, with males generally having much higher levels than females, on average. But, like all aspects of physiology, there is a wide range of what constitutes "normal" values, and there is overlap between the ranges of naturally-occurring male and female levels.
The science of testosterone is fairly well-understood in terms of its anabolic effects. Testosterone enables muscle fiber development to a larger size, and facilitates its maintenance at that size. Testosterone supplements have been used (both knowingly and unknowingly) for decades to help athletes build muscle, and its use was the primary factor which led to the formation of the World Anti-Doping Agency (WADA) and the associated regulations restricting the use of chemicals to enhance the physiology and performance of athletes, especially those competing in sanctioned (e.g., large, high-profile, big money) events.
Over the last few years in particular, however, we have gained an understanding that much of what makes us male or female is not always so perfectly discrete, so categorical. For some aspects of our genetics, anatomy, physiology, and performance, male and female traits are most often clearly binary (e.g., one way or the other). But other of our traits, especially some of our physiology, is not so dimorphic or discrete, and circulating testosterone levels fit into this category.
Males and females generally compete only within same-sex sporting events because, for most events, males hold a competitive advantage. This is certainly true for track-and field race events, which place emphases on speed and endurance. This is not to say that female athletes are in any way unimpressive or not elite - they certainly are, and many would leave male competitors 'in the dust'. But, in general, males outperform females in foot races, and testosterone seems to provide at least some of that advantage, through enhanced muscle size and performance.
Recent analyses have shown that the top female athletes in female track events have testosterone levels higher than the average woman. This is perhaps not a surprise, as these elite female athletes carry more muscle than the average woman as well. We must ask - which came first? Did higher testosterone promote more muscle, which led to racing success? Or does intense training lead to muscle development and an altered hormonal profile? Probably some of both.
This situation has reached a peak in recent years over the case of Caster Semenya, an Olympic medalist who hails from South Africa. By all published accounts, Caster is genetically and physically female, but exhibits hyperandrogenism, a state of producing greater than the normal amount of androgens (male hormones). She is the most-accomplished middle-distance female athlete of the last decade, to the point at which protests against her have been raised, and regulations put in place to prevent her from racing unless she takes medications to reduce her androgen levels. She has appealed those decisions, to no avail.
This issue raises many difficult considerations, from the personal (is this athlete being singled-out? Has her privacy been unfairly invaded?), to the social and political (is this another, familiar case of racism in sport?), to the athletic (is Caster really benefiting from her androgen levels?). As such, it seems unlikely to be settled easily, or soon. Nonetheless, it serves as a useful reminder that natural variability is, well, natural - it is an essential part of what allows us to exist as 7 billion different individuals. There are those among us who are short or tall, thick or thin, slow, - or very fast. Can we really regulate or legislate ourselves into categories, for competition, or for other reasons? Most of our physical and physiological traits vary broadly over a continuum, which means that drawing categorical boundaries may be somewhat artificial. In this case, we seem to have a single physical trait, with a well-understood connection to physical performance, that has become exposed in the very high-profile (and big-money) world of competitive sporting.
https://www.nytimes.com/2019/05/01/health/caster-semenya-testosterone.html
As we learn more about physiology, we are likely to revisit this issue many times again, and in new ways. How long will it be before we hear "Is it fair for me to compete against someone who has a better genetic profile than I do?". I suspect that, in the coming decades, we will be discussing less the physiological and hormonal aspects of physical and mental performance, but rather the genetic bases for them instead.
I'm signing off for the term now. I hope that these weekly news messages have been useful to you. This is the first semester that I have used them to this extent, and it has been a learning experience for me. In particular,
In the end, though, I remain very optimistic. Science is "mankind's organized quest for knowledge" (Floyd Bloom), and we already know that "knowledge is power" (Francis Bacon). It is science that offers us the best hope to deeper understanding, new therapies and treatments, new cures, and new adventures. We will encounter many speed-bumps along the way, to be sure. I hope that our course has inspired you to be a part of this quest, and to make the best use of the knowledge that you gain while on it.
Have a great weekend, and best of luck with all of your exams next week.
Dr. Nealen
(originally posted 04 May 2019)
Good morning all,
As our term comes to a close, I'll use my last news message to send along the latest news from on ongoing story in exercise physiology that raises interesting, and difficult, questions about sex differences in physiology and the regulation of sporting events.
As we have described in class, both males and females have circulating testosterone, with males generally having much higher levels than females, on average. But, like all aspects of physiology, there is a wide range of what constitutes "normal" values, and there is overlap between the ranges of naturally-occurring male and female levels.
The science of testosterone is fairly well-understood in terms of its anabolic effects. Testosterone enables muscle fiber development to a larger size, and facilitates its maintenance at that size. Testosterone supplements have been used (both knowingly and unknowingly) for decades to help athletes build muscle, and its use was the primary factor which led to the formation of the World Anti-Doping Agency (WADA) and the associated regulations restricting the use of chemicals to enhance the physiology and performance of athletes, especially those competing in sanctioned (e.g., large, high-profile, big money) events.
Over the last few years in particular, however, we have gained an understanding that much of what makes us male or female is not always so perfectly discrete, so categorical. For some aspects of our genetics, anatomy, physiology, and performance, male and female traits are most often clearly binary (e.g., one way or the other). But other of our traits, especially some of our physiology, is not so dimorphic or discrete, and circulating testosterone levels fit into this category.
Males and females generally compete only within same-sex sporting events because, for most events, males hold a competitive advantage. This is certainly true for track-and field race events, which place emphases on speed and endurance. This is not to say that female athletes are in any way unimpressive or not elite - they certainly are, and many would leave male competitors 'in the dust'. But, in general, males outperform females in foot races, and testosterone seems to provide at least some of that advantage, through enhanced muscle size and performance.
Recent analyses have shown that the top female athletes in female track events have testosterone levels higher than the average woman. This is perhaps not a surprise, as these elite female athletes carry more muscle than the average woman as well. We must ask - which came first? Did higher testosterone promote more muscle, which led to racing success? Or does intense training lead to muscle development and an altered hormonal profile? Probably some of both.
This situation has reached a peak in recent years over the case of Caster Semenya, an Olympic medalist who hails from South Africa. By all published accounts, Caster is genetically and physically female, but exhibits hyperandrogenism, a state of producing greater than the normal amount of androgens (male hormones). She is the most-accomplished middle-distance female athlete of the last decade, to the point at which protests against her have been raised, and regulations put in place to prevent her from racing unless she takes medications to reduce her androgen levels. She has appealed those decisions, to no avail.
This issue raises many difficult considerations, from the personal (is this athlete being singled-out? Has her privacy been unfairly invaded?), to the social and political (is this another, familiar case of racism in sport?), to the athletic (is Caster really benefiting from her androgen levels?). As such, it seems unlikely to be settled easily, or soon. Nonetheless, it serves as a useful reminder that natural variability is, well, natural - it is an essential part of what allows us to exist as 7 billion different individuals. There are those among us who are short or tall, thick or thin, slow, - or very fast. Can we really regulate or legislate ourselves into categories, for competition, or for other reasons? Most of our physical and physiological traits vary broadly over a continuum, which means that drawing categorical boundaries may be somewhat artificial. In this case, we seem to have a single physical trait, with a well-understood connection to physical performance, that has become exposed in the very high-profile (and big-money) world of competitive sporting.
https://www.nytimes.com/2019/05/01/health/caster-semenya-testosterone.html
As we learn more about physiology, we are likely to revisit this issue many times again, and in new ways. How long will it be before we hear "Is it fair for me to compete against someone who has a better genetic profile than I do?". I suspect that, in the coming decades, we will be discussing less the physiological and hormonal aspects of physical and mental performance, but rather the genetic bases for them instead.
I'm signing off for the term now. I hope that these weekly news messages have been useful to you. This is the first semester that I have used them to this extent, and it has been a learning experience for me. In particular,
- I'm surprised how difficult it has been to find good outlets of timely science news that is digestible by the general public. I hope that my go-to sources become regular stops on your tours of Internet science and health news:
https://www.nytimes.com/section/science
https://www.nytimes.com/section/health
https://www.bbc.com/news/science_and_environment
https://www.bbc.com/news/health
https://www.sciencedaily.com
https://www.washingtonpost.com/health
https://www.sciencenews.org
https://science.sciencemag.org
https://www.livescience.com
https://www.npr.org/sections/science - I'm also surprised how a relatively small number of science topics with little direct application to the majority of our population (like space exploration and dinosaurs) occupy such a large portion of the science news. In some weeks, it was relatively difficult to find recent news related to our lecture topics.
- I'm impressed by, and proud of, the courageous women (and men) of science who are speaking out in support of the MeToo movement, in an effort to 'level the playing field' and make science more inclusive, equal, and safe for all. I sat in your seats as an undergraduate more than 30 yrs ago, and saw then how male-dominated science was, and had been. Since then, it hasn't changed as much as it should have - we still have a long ways to go...
- I'm discouraged how 'big money' from insurance companies, tobacco companies, and environmental lobbyists influences science and health policy. Blending money and politics seems inevitably to lead to bad policy, and bad science policy seems inevitably to set us back in our social progress.
In the end, though, I remain very optimistic. Science is "mankind's organized quest for knowledge" (Floyd Bloom), and we already know that "knowledge is power" (Francis Bacon). It is science that offers us the best hope to deeper understanding, new therapies and treatments, new cures, and new adventures. We will encounter many speed-bumps along the way, to be sure. I hope that our course has inspired you to be a part of this quest, and to make the best use of the knowledge that you gain while on it.
Have a great weekend, and best of luck with all of your exams next week.
Dr. Nealen
Immunization news of the week
(originally posted 27 Apr 2019)
Good morning all,
As you know, I try to send you an article from the science news each week that is relevant to a recent topic we have considered in our class. Some weeks, that requires a little bit of digging, a little reading beyond my usual outlets for science news. This week, however, there is no need to look far, or wide. Our most recent lecture was on immunity, and the science news has been FULL of stories about the immune system, nearly the entire semester.
This week, there are two major news stories related to immune system function. The first of these is just breaking, and will surely be followed by more news to come: the first widespread use of a vaccine against malaria in Africa. We do not hear much about malaria in this country (even though several thousand cases occur in the U.S. every year), but it is a tropical scourge across much of the globe. It is caused by the malarial parasite Plasmodium falciparum, carried by mosquitoes and transferred between human hosts by their bites. It is very infectious - estimates suggest that more than 200,000,000 (that's 200 million) cases occur each year. It's also very deadly, causing >400,000 deaths per year. Children are especially vulnerable. I heard a news report this week that estimated that every 2 minutes, an African child dies of malaria.
As a disease, malaria is very problematic. Its mosquito hosts are very numerous, widespread, difficult to control, and difficult to avoid. The parasite passes directly into the human host circulatory system during a mosquito blood meal, where it takes up residence inside of red blood cells. Remember that disease agents that get inside of our cells are hard to combat - they are at least partially hidden/protected from immune surveillance, and should they be detected and their host cell destroyed, it results in the net loss of functional host cells, potentially even releasing more parasites to infect other cells. Persons suffering from malaria have symptoms ranging from mild (tiredness, chills, aches) to severe (high fevers, blood clots, kidney damage), and aggressive treatment with anti-parasitic drugs (such as Chloroquine) is normally required. Anti-parasitic drugs can also be used prophylactically (e.g., to prevent infection before it happens), but their efficacy is not perfect and varies considerably against the different strains of the malarial parasite. For all of these reasons, an effective vaccine would be a great benefit.
In the news this week is report of the first widespread use of a moderately-effective, inexpensive, anti-malaria vaccine. It was developed over the last 30 years, following promising laboratory studies (the development of a pharmaceutical, from lab bench to use in human populations, can be VERY long). It is suggested to be only ~30% effective in protecting against malaria. But, if 30% of the hundreds of thousands of deaths that occur each year can be prevented, it will be very worthwhile - imagine being able to create a vaccine that prevents 100,000 deaths each year! In addition, much will be learned from this first really large human trial of the vaccine, and the data that will be collected on its efficacy will likely lead to improvements in the vaccine itself.
https://www.nature.com/articles/d41586-019-01342-z
https://www.who.int/news-room/detail/23-04-2019-malaria-vaccine-pilot-launched-in-malawi
https://www.cdc.gov/parasites/malaria/
The other big story related to immunity this week also relates to infectious disease and immunizations, this time for measles. Measles is a very highly infectious disease caused by the measles virus. It causes rashes, aches, and often dangerously-high fevers, and can be fatal to vulnerable subjects. In most developed parts of the world, measles has largely been eradicated, through successful development and use of the measles vaccine, commonly given as one part of the MMR (measles-mumps-rubella) vaccine. Very recently, however, there are severe outbreaks of measles in several locations in this country (including New York City).
These recent outbreaks in the U.S. have been caused by a combination of two factors. The first is a reduced number of parents having their children vaccinated against measles, in large part due to false information about the potential harm caused by vaccines. Over the past decade, several widely reported (but now discredited) stories have circulated about the use of the preservative thimerosol in vaccines, which has led some to believe that the vaccines themselves are more dangerous than the diseases they are designed to prevent. In addition, the vaccine is so effective that measles is rarely reported, so many believe that it is no longer even necessary. Together, these cause lower rates of vaccination in some populations.
The other causative agent is the introduction of the disease from elsewhere, in these cases from travelers who visited areas in the Middle East, picked-up the virus, and brought it back to their U.S. communities. The symptoms of measles may not appear for weeks after exposure, so persons who carry the virus but do not yet realize it can very easily pass it unknowingly to others.
Vaccinations protect individuals if they encounter an agent of disease, because it primes their immune systems (remember those memory cells?) to make rapid and robust responses upon subsequent exposure to an antigen, such as that of the measles virus. Vaccinations also work at a population level, by reducing the likelihood of encountering a disease in the first place. This is the concept of "herd immunity" - if everyone in a population is vaccinated, the chances of encountering someone who could pass on the disease is very low. Measles is extremely infectious (via sneezing/coughing), such that ~95% vaccination rates are necessary for "herd immunity" against measles to be available. In select populations, immunization rates have fallen well below this level.
This combination of factors (reduced immunization rates, highly infectious virus) leads to disease outbreaks. In addition to large outbreaks in New York and Washington state, several college campus in California began quarantining personnel, in an attempt to control measles outbreaks.
https://www.sciencenews.org/article/us-measles-cases-record-high-disease-eliminated-2000
https://www.washingtonpost.com/national/health-science/over-1000-quarantined-in-measles-scare-at-la-universities/2019/04/26/79e29cdc-6881-11e9-a698-2a8f808c9cfb_story.html
https://www.cdc.gov/measles/index.html
https://www.cdc.gov/vaccinesafety/concerns/thimerosal/index.html
Just as our immune systems are wonderfully adapted to protect us from agents of disease, so too are those same agents of disease evolved to evade our immune defenses. It's an evolutionary 'arms race', and, left on its own, would continue that way. Vaccinations give us a terrific advantage against some infectious diseases - but only if those vaccines are safe, available, and accepted. Are they perfect? Of course not - but the scientific community is very much in agreement that they are better than facing the risks without them. If you hear of anyone near you having measles, make sure that you and your family are protected.
Have a great weekend -
Dr. Nealen
(originally posted 27 Apr 2019)
Good morning all,
As you know, I try to send you an article from the science news each week that is relevant to a recent topic we have considered in our class. Some weeks, that requires a little bit of digging, a little reading beyond my usual outlets for science news. This week, however, there is no need to look far, or wide. Our most recent lecture was on immunity, and the science news has been FULL of stories about the immune system, nearly the entire semester.
This week, there are two major news stories related to immune system function. The first of these is just breaking, and will surely be followed by more news to come: the first widespread use of a vaccine against malaria in Africa. We do not hear much about malaria in this country (even though several thousand cases occur in the U.S. every year), but it is a tropical scourge across much of the globe. It is caused by the malarial parasite Plasmodium falciparum, carried by mosquitoes and transferred between human hosts by their bites. It is very infectious - estimates suggest that more than 200,000,000 (that's 200 million) cases occur each year. It's also very deadly, causing >400,000 deaths per year. Children are especially vulnerable. I heard a news report this week that estimated that every 2 minutes, an African child dies of malaria.
As a disease, malaria is very problematic. Its mosquito hosts are very numerous, widespread, difficult to control, and difficult to avoid. The parasite passes directly into the human host circulatory system during a mosquito blood meal, where it takes up residence inside of red blood cells. Remember that disease agents that get inside of our cells are hard to combat - they are at least partially hidden/protected from immune surveillance, and should they be detected and their host cell destroyed, it results in the net loss of functional host cells, potentially even releasing more parasites to infect other cells. Persons suffering from malaria have symptoms ranging from mild (tiredness, chills, aches) to severe (high fevers, blood clots, kidney damage), and aggressive treatment with anti-parasitic drugs (such as Chloroquine) is normally required. Anti-parasitic drugs can also be used prophylactically (e.g., to prevent infection before it happens), but their efficacy is not perfect and varies considerably against the different strains of the malarial parasite. For all of these reasons, an effective vaccine would be a great benefit.
In the news this week is report of the first widespread use of a moderately-effective, inexpensive, anti-malaria vaccine. It was developed over the last 30 years, following promising laboratory studies (the development of a pharmaceutical, from lab bench to use in human populations, can be VERY long). It is suggested to be only ~30% effective in protecting against malaria. But, if 30% of the hundreds of thousands of deaths that occur each year can be prevented, it will be very worthwhile - imagine being able to create a vaccine that prevents 100,000 deaths each year! In addition, much will be learned from this first really large human trial of the vaccine, and the data that will be collected on its efficacy will likely lead to improvements in the vaccine itself.
https://www.nature.com/articles/d41586-019-01342-z
https://www.who.int/news-room/detail/23-04-2019-malaria-vaccine-pilot-launched-in-malawi
https://www.cdc.gov/parasites/malaria/
The other big story related to immunity this week also relates to infectious disease and immunizations, this time for measles. Measles is a very highly infectious disease caused by the measles virus. It causes rashes, aches, and often dangerously-high fevers, and can be fatal to vulnerable subjects. In most developed parts of the world, measles has largely been eradicated, through successful development and use of the measles vaccine, commonly given as one part of the MMR (measles-mumps-rubella) vaccine. Very recently, however, there are severe outbreaks of measles in several locations in this country (including New York City).
These recent outbreaks in the U.S. have been caused by a combination of two factors. The first is a reduced number of parents having their children vaccinated against measles, in large part due to false information about the potential harm caused by vaccines. Over the past decade, several widely reported (but now discredited) stories have circulated about the use of the preservative thimerosol in vaccines, which has led some to believe that the vaccines themselves are more dangerous than the diseases they are designed to prevent. In addition, the vaccine is so effective that measles is rarely reported, so many believe that it is no longer even necessary. Together, these cause lower rates of vaccination in some populations.
The other causative agent is the introduction of the disease from elsewhere, in these cases from travelers who visited areas in the Middle East, picked-up the virus, and brought it back to their U.S. communities. The symptoms of measles may not appear for weeks after exposure, so persons who carry the virus but do not yet realize it can very easily pass it unknowingly to others.
Vaccinations protect individuals if they encounter an agent of disease, because it primes their immune systems (remember those memory cells?) to make rapid and robust responses upon subsequent exposure to an antigen, such as that of the measles virus. Vaccinations also work at a population level, by reducing the likelihood of encountering a disease in the first place. This is the concept of "herd immunity" - if everyone in a population is vaccinated, the chances of encountering someone who could pass on the disease is very low. Measles is extremely infectious (via sneezing/coughing), such that ~95% vaccination rates are necessary for "herd immunity" against measles to be available. In select populations, immunization rates have fallen well below this level.
This combination of factors (reduced immunization rates, highly infectious virus) leads to disease outbreaks. In addition to large outbreaks in New York and Washington state, several college campus in California began quarantining personnel, in an attempt to control measles outbreaks.
https://www.sciencenews.org/article/us-measles-cases-record-high-disease-eliminated-2000
https://www.washingtonpost.com/national/health-science/over-1000-quarantined-in-measles-scare-at-la-universities/2019/04/26/79e29cdc-6881-11e9-a698-2a8f808c9cfb_story.html
https://www.cdc.gov/measles/index.html
https://www.cdc.gov/vaccinesafety/concerns/thimerosal/index.html
Just as our immune systems are wonderfully adapted to protect us from agents of disease, so too are those same agents of disease evolved to evade our immune defenses. It's an evolutionary 'arms race', and, left on its own, would continue that way. Vaccinations give us a terrific advantage against some infectious diseases - but only if those vaccines are safe, available, and accepted. Are they perfect? Of course not - but the scientific community is very much in agreement that they are better than facing the risks without them. If you hear of anyone near you having measles, make sure that you and your family are protected.
Have a great weekend -
Dr. Nealen
This Genetic Mutation Makes People Feel Full — All the Time - The New York Times
(originally posted 20 Apr 2019)
Good morning everyone,
Our lecture on Tuesday of this week described the essentials of digestion, and Thursday's topic followed with consideration of metabolism and energy balance as a whole. In the science news this week is a new study on these very topics, with description of a genetic mutation that influences both.
During our digestion lecture, I noted that much of its function is regulated autonomically, by local reflexes mediated in the ENS. That is to say, the digestive tract functions more or less on its own when food is presented to it. By inference then, regulation of food acquisition controls the overall amount of digestion we perform, and the number of calories we have available to use or store.
Regulation of hunger, food-seeking, and feelings of satiety (satisfaction of hunger, or "fullness") occur largely through the hypothalamus, where a variety of chemical signals are known to promote either orexigenic (food-seeking) or anorectic (satiety) states. These include a number of cryptically-named chemicals such as CART, alpha-MSH, agouti-related peptide (AgRP), and melanocortin (MC), each acting at hypothalamic cells bearing specific receptors for them. A great deal of experimental work over the last several decades (mostly in mouse models) has demonstrated that disruption of their signaling (via increased activation of their receptors, or blockade of them) can cause food consumption and body mass to either increase, or decrease.
Abnormally-elevated body mass to the point of obesity has reached critical levels in this country. Depending upon the guidelines one uses, it has been estimated that 30-40% of adults in this country are obese, with another substantial proportion of the population classified as overweight. Extra body mass is a significant health complication, raising one's risk of a number of diseases (including hypertension and diabetes) and complicating treatment and prevention of many others. As such, there is an enormous research effort underway to explore the roots of obesity. We know for certain that the issue is complex - socioeconomic status, willpower, behavior, access to high-quality foods, and sociality influence our food choices, eating habits, and body mass, in ways that are both many and complicated. Increasingly, there is growing appreciation of genetic components to obesity as well.
Modern genetic assessments of health have benefited by technological advances that allow sequencing of individual genomes, resulting in large databases of genetic information. When these are paired with health profiles and lifestyle data, they make possible genome-wide association studies (GWAS). GWAS represent a powerful way to take two very large sets of data (gene sequences and health/lifestyle data) and see how/where they intersect. In contrast to the twin study I described to you in my science news email last week, GWAS are useful only when based upon thousands (usually, hundreds of thousands) of individuals. These are not experimental methods, so they cannot provide definitive proof of anything, but they can reveal interesting "associations" - places where genetics and health vary in consistent ways.
This new study describes a GWAS that sought genetic bases for obesity. In a very large sample of human subjects (500,000 individuals), the researchers looked for consistent genetic mutations in people who were, or were not, obese. They found evidence for specific genetic variation in the MC4R gene (melanocortin receptor 4) that was associated with obesity: persons whose MCR4 gene was mutated (causing reduced function) were much more likely to be obese that those who carried the 'normal' version of the gene. To some extent, this finding was not new - this effect of MCR4 mutation had been described previously, in smaller studies. Here, though, the researchers also found evidence that if mutations in the gene(s) that regulate MCR4 cause it to be 'turned on' all of the time (instead of occasionally, such as after eating), it causes chronic satiety, or "fullness". Persons with this form of mutation are much less likely to be obese, so the researchers interpret this alteration of MCR4 function as protective, and preventive of obesity.
Thus, we may have a single gene, which if mutated in one fashion can contribute to obesity, and if dis-regulated in another way can protect against it. A second study described in this same article uses similar data to create a genetic risk assessment for obesity, with the hope of reducing its prevalence, potentially by intervening before it reaches criticality.
https://www.nytimes.com/2019/04/18/health/genetics-weight-obesity.html
The genetic associations described in this study are not enormous, just a few percent (perhaps 6%). Still, they represent the largest known genetic association for obesity, and that in and of itself is a very worthwhile finding. Many persons who are obese suffer from anxiety, depression, and feelings of low self-worth, thinking (and too-often being told) that they are 'fat', or overweight, because of their behavior and lack of willpower. What if the problem lies in their genes, and not in their self-control? We all know how difficult it is to resist food when we are hungry - what if that feeling never goes away?
Like most science, these studies raise more questions than they answer. Obesity and weight control are such significant problems, though, that their investigation is crucial to improved public health. Here's to more studies and more information on these topics - they are likely to benefit us at a variety of levels: individually, via our loved ones, or as part of society as a whole.
Have a great weekend -
Dr. Nealen
(originally posted 20 Apr 2019)
Good morning everyone,
Our lecture on Tuesday of this week described the essentials of digestion, and Thursday's topic followed with consideration of metabolism and energy balance as a whole. In the science news this week is a new study on these very topics, with description of a genetic mutation that influences both.
During our digestion lecture, I noted that much of its function is regulated autonomically, by local reflexes mediated in the ENS. That is to say, the digestive tract functions more or less on its own when food is presented to it. By inference then, regulation of food acquisition controls the overall amount of digestion we perform, and the number of calories we have available to use or store.
Regulation of hunger, food-seeking, and feelings of satiety (satisfaction of hunger, or "fullness") occur largely through the hypothalamus, where a variety of chemical signals are known to promote either orexigenic (food-seeking) or anorectic (satiety) states. These include a number of cryptically-named chemicals such as CART, alpha-MSH, agouti-related peptide (AgRP), and melanocortin (MC), each acting at hypothalamic cells bearing specific receptors for them. A great deal of experimental work over the last several decades (mostly in mouse models) has demonstrated that disruption of their signaling (via increased activation of their receptors, or blockade of them) can cause food consumption and body mass to either increase, or decrease.
Abnormally-elevated body mass to the point of obesity has reached critical levels in this country. Depending upon the guidelines one uses, it has been estimated that 30-40% of adults in this country are obese, with another substantial proportion of the population classified as overweight. Extra body mass is a significant health complication, raising one's risk of a number of diseases (including hypertension and diabetes) and complicating treatment and prevention of many others. As such, there is an enormous research effort underway to explore the roots of obesity. We know for certain that the issue is complex - socioeconomic status, willpower, behavior, access to high-quality foods, and sociality influence our food choices, eating habits, and body mass, in ways that are both many and complicated. Increasingly, there is growing appreciation of genetic components to obesity as well.
Modern genetic assessments of health have benefited by technological advances that allow sequencing of individual genomes, resulting in large databases of genetic information. When these are paired with health profiles and lifestyle data, they make possible genome-wide association studies (GWAS). GWAS represent a powerful way to take two very large sets of data (gene sequences and health/lifestyle data) and see how/where they intersect. In contrast to the twin study I described to you in my science news email last week, GWAS are useful only when based upon thousands (usually, hundreds of thousands) of individuals. These are not experimental methods, so they cannot provide definitive proof of anything, but they can reveal interesting "associations" - places where genetics and health vary in consistent ways.
This new study describes a GWAS that sought genetic bases for obesity. In a very large sample of human subjects (500,000 individuals), the researchers looked for consistent genetic mutations in people who were, or were not, obese. They found evidence for specific genetic variation in the MC4R gene (melanocortin receptor 4) that was associated with obesity: persons whose MCR4 gene was mutated (causing reduced function) were much more likely to be obese that those who carried the 'normal' version of the gene. To some extent, this finding was not new - this effect of MCR4 mutation had been described previously, in smaller studies. Here, though, the researchers also found evidence that if mutations in the gene(s) that regulate MCR4 cause it to be 'turned on' all of the time (instead of occasionally, such as after eating), it causes chronic satiety, or "fullness". Persons with this form of mutation are much less likely to be obese, so the researchers interpret this alteration of MCR4 function as protective, and preventive of obesity.
Thus, we may have a single gene, which if mutated in one fashion can contribute to obesity, and if dis-regulated in another way can protect against it. A second study described in this same article uses similar data to create a genetic risk assessment for obesity, with the hope of reducing its prevalence, potentially by intervening before it reaches criticality.
https://www.nytimes.com/2019/04/18/health/genetics-weight-obesity.html
The genetic associations described in this study are not enormous, just a few percent (perhaps 6%). Still, they represent the largest known genetic association for obesity, and that in and of itself is a very worthwhile finding. Many persons who are obese suffer from anxiety, depression, and feelings of low self-worth, thinking (and too-often being told) that they are 'fat', or overweight, because of their behavior and lack of willpower. What if the problem lies in their genes, and not in their self-control? We all know how difficult it is to resist food when we are hungry - what if that feeling never goes away?
Like most science, these studies raise more questions than they answer. Obesity and weight control are such significant problems, though, that their investigation is crucial to improved public health. Here's to more studies and more information on these topics - they are likely to benefit us at a variety of levels: individually, via our loved ones, or as part of society as a whole.
Have a great weekend -
Dr. Nealen
Scott Kelly Spent a Year in Orbit. His Body Is Not Quite the Same
(originally posted 13 Apr 2019)
Good morning everyone,
As we enter the last quarter of out term, we soon will be considering the remaining chapters in our text, on topics including digestion, immunity, metabolism, and reproduction. These are relatively 'integrated' phenomena - complex and intertwined with other of our physiological systems and processes.
In the science news this week is a report that is similarly integrated, on simultaneously both a larger scale (the entire body) and a smaller one (examination of just one person, relative to one other).
Nearly all quality research in physiology (like that of other fields) relies on large sample sizes - studies of hundreds, thousands, or even millions of individuals. The larger the sample, often the greater the statistical power of the comparisons, the ability to detect tiny effects. Does this drug lower blood pressure? How does a vegan diet influence sleep habits? What are the genetic components of immunity? Studies like these would never evaluate one or two subjects, because the ability to generalize the results would be very low. And, studies employing few subjects would be very unlikely to be funded or pursued, for exactly that reason.
But, NASA's study of astronaut Scott Kelly (and comparison to his Earth-bound twin Mark) is quite unique, in many ways: how many of us will ever spend (nearly) a year in space? So, far, perhaps just a handful of people. How many of these individuals have an identical twin? Just one.
Scott and Mark were subjected to a battery of tests before, during, and after Scott's 340 day long space aboard the International Space Station. How does a life in space influence the body? Well, in many ways, as it turns out. Why do we care? Because, as a society, we continue to push the boundaries of space travel, and long journeys in space (to Mars, or other places) are surely on the horizon. What will happen during those trips? Scott and Mark Kelly offer a useful, and unique window into this problem. Because they are genetically identical, in theory, any differences between them should be due to their environments. If they were carefully evaluated before, and then after, Scott's year in space, it should allow us to see what space travel does to the body, by comparing Scott and Mark.
If Scott Kelly is a useful model, life in space will be very challenging, physiologically. Among the largest changes noted upon his return to Earth were cognitive deficits, colonization of his body by different kinds and numbers of bacteria, indicators of high stress levels (no surprise), many genetic mutations, and, surprisingly, longer telomeres on his chromosomes. This last finding was unexpected - telomere length is a sign of cell age, and long telomeres are normally interpreted as a sign of youth. Does space travel reverse aging? Probably not! It's more likely that the rigors of space life (especially the radiation exposure) triggered lots of repair and replacement of damaged cells, and newly created cells may have higher levels of telomere maintenance.
https://www.nytimes.com/2019/04/11/science/scott-mark-kelly-twins-space-nasa.html
In many ways, Mr. Kelly has offered himself as a 'guinea pig' for these studies - even now, back on Earth for years, many of his symptoms and genetic mutations remain. Was it worth it? His answer is an unequivocal 'yes'. Like other astronauts before and after him, his experiences were literally other-worldly. Our technological advances toward space may be outpacing our physiological ones, however. If Mr. Kelly's response is typical of what will happen to the human body in space, we have much to learn, and much work to do, before long-term stays in space will become feasible.
Not to say that all of the news is negative: he took some amazing photos while he was there:
https://www.nytimes.com/2019/04/12/science/scott-kellys-photos-space.html
Have a great weekend -
Dr. Nealen
(originally posted 13 Apr 2019)
Good morning everyone,
As we enter the last quarter of out term, we soon will be considering the remaining chapters in our text, on topics including digestion, immunity, metabolism, and reproduction. These are relatively 'integrated' phenomena - complex and intertwined with other of our physiological systems and processes.
In the science news this week is a report that is similarly integrated, on simultaneously both a larger scale (the entire body) and a smaller one (examination of just one person, relative to one other).
Nearly all quality research in physiology (like that of other fields) relies on large sample sizes - studies of hundreds, thousands, or even millions of individuals. The larger the sample, often the greater the statistical power of the comparisons, the ability to detect tiny effects. Does this drug lower blood pressure? How does a vegan diet influence sleep habits? What are the genetic components of immunity? Studies like these would never evaluate one or two subjects, because the ability to generalize the results would be very low. And, studies employing few subjects would be very unlikely to be funded or pursued, for exactly that reason.
But, NASA's study of astronaut Scott Kelly (and comparison to his Earth-bound twin Mark) is quite unique, in many ways: how many of us will ever spend (nearly) a year in space? So, far, perhaps just a handful of people. How many of these individuals have an identical twin? Just one.
Scott and Mark were subjected to a battery of tests before, during, and after Scott's 340 day long space aboard the International Space Station. How does a life in space influence the body? Well, in many ways, as it turns out. Why do we care? Because, as a society, we continue to push the boundaries of space travel, and long journeys in space (to Mars, or other places) are surely on the horizon. What will happen during those trips? Scott and Mark Kelly offer a useful, and unique window into this problem. Because they are genetically identical, in theory, any differences between them should be due to their environments. If they were carefully evaluated before, and then after, Scott's year in space, it should allow us to see what space travel does to the body, by comparing Scott and Mark.
If Scott Kelly is a useful model, life in space will be very challenging, physiologically. Among the largest changes noted upon his return to Earth were cognitive deficits, colonization of his body by different kinds and numbers of bacteria, indicators of high stress levels (no surprise), many genetic mutations, and, surprisingly, longer telomeres on his chromosomes. This last finding was unexpected - telomere length is a sign of cell age, and long telomeres are normally interpreted as a sign of youth. Does space travel reverse aging? Probably not! It's more likely that the rigors of space life (especially the radiation exposure) triggered lots of repair and replacement of damaged cells, and newly created cells may have higher levels of telomere maintenance.
https://www.nytimes.com/2019/04/11/science/scott-mark-kelly-twins-space-nasa.html
In many ways, Mr. Kelly has offered himself as a 'guinea pig' for these studies - even now, back on Earth for years, many of his symptoms and genetic mutations remain. Was it worth it? His answer is an unequivocal 'yes'. Like other astronauts before and after him, his experiences were literally other-worldly. Our technological advances toward space may be outpacing our physiological ones, however. If Mr. Kelly's response is typical of what will happen to the human body in space, we have much to learn, and much work to do, before long-term stays in space will become feasible.
Not to say that all of the news is negative: he took some amazing photos while he was there:
https://www.nytimes.com/2019/04/12/science/scott-kellys-photos-space.html
Have a great weekend -
Dr. Nealen
Defining chronic kidney disease at the genetic level | Science Translational Medicine
(originally posted 06 Apr 2019)
Good morning all,
In our last two lectures of this third unit of the course, we are considering renal function and the often overlooked role of the kidneys in our health and well-being. During lecture on Thursday, I mentioned several facts related to kidney disease and failure that some recent science news can inform.
We discussed conditions such as diabetes and hypertension that can induce kidney damage and failure, and the third items on that list was genetic bases for kidney ailments. One of the reasons that we did not elaborate on the topic is that the specific genetic causes of kidney disease (like that of so many other of our diseases) is very nebulous - there are many genes involved, often with very weak effects, and their interactions with each other and with environmental influences are poorly understood. In these situations, patients often recognize that they are part of a family history of disease (suggesting its genetic basis), but typically the genes involved are not identified, or their function is not characterized.
Recently, several research teams have made progress on this issue. Using exome sequencing (a DNA sequencing method that focuses only upon the protein-coding regions of our DNA), researchers recently have described with greater detail the number of different genes involved in a small sample of patients with chronic kidney disease. They identify over 60 different genes, some with identified roles as membrane transporters or regulators of gene expression. Most of these were associated with a tiny number of disease cases.
http://stm.sciencemag.org/content/11/474/eaaw0532
As is often the case, studies like this are useful if only because they reveal how much we have yet to learn, and offer a potential method forward. It's a very long (and expensive) pathway from gene identification, to functional investigation, to testing of therapeutics, to useful treatments, and most avenues of exploration do not yield breakthroughs. But, we now know more than we did, and there is great interest in finding ways to abate kidney disease. There are still a great number of people awaiting kidney transplants, and many die while they wait. Inequities of access to donated organs may be part of the problem. Perhaps we should pay people for organ donation - or would that be more problematic than useful?
https://www.washingtonpost.com/opinions/the-us-organ-transplant-system-is-broken-but-the-latest-fix-will-make-it-worse/2019/04/02/41ef2b1c-555b-11e9-8ef3-fbd41a2ce4d5_story.html
https://www.washingtonpost.com/opinions/what-if-we-paid-people-to-donate-their-kidneys-to-strangers/2019/01/08/6f397a0c-1391-11e9-b6ad-9cfd62dbb0a8_story.html
Have a great weekend -
Dr. Nealen
(originally posted 06 Apr 2019)
Good morning all,
In our last two lectures of this third unit of the course, we are considering renal function and the often overlooked role of the kidneys in our health and well-being. During lecture on Thursday, I mentioned several facts related to kidney disease and failure that some recent science news can inform.
We discussed conditions such as diabetes and hypertension that can induce kidney damage and failure, and the third items on that list was genetic bases for kidney ailments. One of the reasons that we did not elaborate on the topic is that the specific genetic causes of kidney disease (like that of so many other of our diseases) is very nebulous - there are many genes involved, often with very weak effects, and their interactions with each other and with environmental influences are poorly understood. In these situations, patients often recognize that they are part of a family history of disease (suggesting its genetic basis), but typically the genes involved are not identified, or their function is not characterized.
Recently, several research teams have made progress on this issue. Using exome sequencing (a DNA sequencing method that focuses only upon the protein-coding regions of our DNA), researchers recently have described with greater detail the number of different genes involved in a small sample of patients with chronic kidney disease. They identify over 60 different genes, some with identified roles as membrane transporters or regulators of gene expression. Most of these were associated with a tiny number of disease cases.
http://stm.sciencemag.org/content/11/474/eaaw0532
As is often the case, studies like this are useful if only because they reveal how much we have yet to learn, and offer a potential method forward. It's a very long (and expensive) pathway from gene identification, to functional investigation, to testing of therapeutics, to useful treatments, and most avenues of exploration do not yield breakthroughs. But, we now know more than we did, and there is great interest in finding ways to abate kidney disease. There are still a great number of people awaiting kidney transplants, and many die while they wait. Inequities of access to donated organs may be part of the problem. Perhaps we should pay people for organ donation - or would that be more problematic than useful?
https://www.washingtonpost.com/opinions/the-us-organ-transplant-system-is-broken-but-the-latest-fix-will-make-it-worse/2019/04/02/41ef2b1c-555b-11e9-8ef3-fbd41a2ce4d5_story.html
https://www.washingtonpost.com/opinions/what-if-we-paid-people-to-donate-their-kidneys-to-strangers/2019/01/08/6f397a0c-1391-11e9-b6ad-9cfd62dbb0a8_story.html
Have a great weekend -
Dr. Nealen
A bad bout of flu triggers 'taste bud cells' to grow in the lungs -- ScienceDaily
(originally posted 30 Mar 2019)
Good morning all,
As we slip slowly into Spring, it's easy to forget that we still are within flu (influenza) season. We should also remember that the latter half of flu season this year is characterized by a more-virulent flu strain than was common during the first half of this year's flu season, which explains why reports of flu-like illness have risen in recent weeks.
Seasonal flu is caused by influenza virus, whose make-up changes from one season to the next as well as over the course of an individual flu season - this is one of the reasons that 'flu shots' (vaccinations against the influenza virus) are recommended every year. Normally, last year's flu vaccine won't protect us this year, and sometimes the vaccine works very poorly altogether.
For most of us, flu is a passing annoyance, but influenza can be deadly - 10,000 people have died from the flu in this country during flu season this year. Last year's flu was particularly deadly, causing 80,000 deaths in the U.S. Most are caused by respiratory failure.
Influenza virus infects our respiratory mucosa (the linings of our respiratory tracts), triggering inflammation and cell death. Much research is aimed at determining how our immune systems detect the virus and attempt to prevent its effects, and new research out this week suggests a surprising tool: taste receptor-like cells, known as tuft cells. They had long been known to exist, but their function was never clear.
This new research shows that tuft cells in our respiratory tract and lungs proliferate and trigger immune responses when virus is detected. Interestingly, they can be promoted across much of the body - including our respiratory tract, out intestines, even our bladder. After infection from flu virus, they appear to remain activated and cause sustained inflammation, which can trigger long-tern allergies and tissue remodeling. Inflammation is a very useful part of our immune function, but it can also provide unnecessary side-effects (allergies, anyone?) and tissue damage if pronounced.
https://www.sciencedaily.com/releases/2019/03/190328150948.htm
Fortunately, the best defense against the flu is easy: cover your coughs and sneezes, and wash your hands! Otherwise, prepare for your tuft cells to 'Spring' into action (pun intended).
Have a great weekend -
Dr. Nealen
(originally posted 30 Mar 2019)
Good morning all,
As we slip slowly into Spring, it's easy to forget that we still are within flu (influenza) season. We should also remember that the latter half of flu season this year is characterized by a more-virulent flu strain than was common during the first half of this year's flu season, which explains why reports of flu-like illness have risen in recent weeks.
Seasonal flu is caused by influenza virus, whose make-up changes from one season to the next as well as over the course of an individual flu season - this is one of the reasons that 'flu shots' (vaccinations against the influenza virus) are recommended every year. Normally, last year's flu vaccine won't protect us this year, and sometimes the vaccine works very poorly altogether.
For most of us, flu is a passing annoyance, but influenza can be deadly - 10,000 people have died from the flu in this country during flu season this year. Last year's flu was particularly deadly, causing 80,000 deaths in the U.S. Most are caused by respiratory failure.
Influenza virus infects our respiratory mucosa (the linings of our respiratory tracts), triggering inflammation and cell death. Much research is aimed at determining how our immune systems detect the virus and attempt to prevent its effects, and new research out this week suggests a surprising tool: taste receptor-like cells, known as tuft cells. They had long been known to exist, but their function was never clear.
This new research shows that tuft cells in our respiratory tract and lungs proliferate and trigger immune responses when virus is detected. Interestingly, they can be promoted across much of the body - including our respiratory tract, out intestines, even our bladder. After infection from flu virus, they appear to remain activated and cause sustained inflammation, which can trigger long-tern allergies and tissue remodeling. Inflammation is a very useful part of our immune function, but it can also provide unnecessary side-effects (allergies, anyone?) and tissue damage if pronounced.
https://www.sciencedaily.com/releases/2019/03/190328150948.htm
Fortunately, the best defense against the flu is easy: cover your coughs and sneezes, and wash your hands! Otherwise, prepare for your tuft cells to 'Spring' into action (pun intended).
Have a great weekend -
Dr. Nealen
Here’s Why a 50-Degree Day Feels Colder in Fall Than in Spring - The New York Times
(originally posted 23 Mar 2019)
Good morning,
As we (hopefully? finally?) transition from winter into spring, we find that we enjoy even slightly warmer days than we have been experiencing, even if the same temperature is enjoyed less at other times of the year (for example, as autumn cools into winter). Why should a 50 °F day be perceived differently, at different times of the year?
Part of the answer has always been assumed to be psychological: we evaluate new conditions relative to what we have recently experienced, and warmer days in the spring are enjoyed relative to the recent, cooler temperature of winter. Increasingly, however, evidence is growing that suggests a physiological component, based on relatively gradual acclimation to prevailing temperatures over a longer term (weeks, months, or longer).
These data suggest that long-term physiological responses to temperature gradually shape our vasoconstriction and blood delivery to the surface (you knew there was a link to our current lecture topics!), as well as our sensitivity and tolerance to temperatures below and above our 'comfort zone'. This is part of a systemic response: our peripheral blood delivery is altered, our sensory systems modulate their responsiveness to temperature, and our minds reduce expectations of a quick change back to more moderate temperatures (which reduces disappoint when temperatures remain extreme).
https://www.nytimes.com/2018/10/24/science/human-bodies-cold-weather-adjustment.html
So, the next time you are enjoying a bit of sunshine on a brisk Spring day, remember that the pleasure of it is not 'all in your head' - some of it is in your skin, and your arterioles, and your hypothalamus, and your skeletal muscles, ....
Happy Spring -
Dr. Nealen
(originally posted 23 Mar 2019)
Good morning,
As we (hopefully? finally?) transition from winter into spring, we find that we enjoy even slightly warmer days than we have been experiencing, even if the same temperature is enjoyed less at other times of the year (for example, as autumn cools into winter). Why should a 50 °F day be perceived differently, at different times of the year?
Part of the answer has always been assumed to be psychological: we evaluate new conditions relative to what we have recently experienced, and warmer days in the spring are enjoyed relative to the recent, cooler temperature of winter. Increasingly, however, evidence is growing that suggests a physiological component, based on relatively gradual acclimation to prevailing temperatures over a longer term (weeks, months, or longer).
These data suggest that long-term physiological responses to temperature gradually shape our vasoconstriction and blood delivery to the surface (you knew there was a link to our current lecture topics!), as well as our sensitivity and tolerance to temperatures below and above our 'comfort zone'. This is part of a systemic response: our peripheral blood delivery is altered, our sensory systems modulate their responsiveness to temperature, and our minds reduce expectations of a quick change back to more moderate temperatures (which reduces disappoint when temperatures remain extreme).
https://www.nytimes.com/2018/10/24/science/human-bodies-cold-weather-adjustment.html
So, the next time you are enjoying a bit of sunshine on a brisk Spring day, remember that the pleasure of it is not 'all in your head' - some of it is in your skin, and your arterioles, and your hypothalamus, and your skeletal muscles, ....
Happy Spring -
Dr. Nealen
Exercise vs. Drugs to Treat High Blood Pressure and Reduce Fat - The New York Times
(originally posted 16 Mar 2019)
Good morning all,
I hope that you have had an excellent Break, and are ready for the second half of our term!
We will begin our third unit of the semester with consideration of the cardiac and pulmonary systems. There is much in our upcoming chapters that will be familiar (we all have some inherent understanding of how these systems function) and important (cardiovascular pathology is a leading contributor to human morbidity and mortality). Health science research and news is dominated by several major fields, including cancer, infectious disease, and cardiopulmonary health, for they are at the forefront of what ails us.
One critical feature of our cardiac and pulmonary function is its malleability - we have real power to change how these systems perform, through our habits. Lack of exercise and poor lifestyle choices (in terms of diet, tobacco use, alcohol/drugs) plague too many of us, and a large component of the pharmaceutical industry is geared toward making medications that influence our cardiovascular and pulmonary health. But, we already hold the power to improve our condition, through exercise. Exertion is a form of physiological stress, and (within reason), it is a useful stress - our tissues respond to extra use with improved effectiveness. But, the temptation to simply 'pop a pill', or the lack of available time for exercise, makes it difficult for most of us to meet fitness goals (such as 150 min of moderate exercise per week).
Are these options equivalent? Here's a link to a recent study that makes this type of comparison: are medications or exercise better for treating/managing high blood pressure and body fat stores?
https://www.nytimes.com/2019/03/13/well/move/exercise-vs-drugs-to-treat-high-blood-pressure-and-reduce-fat.html
This study reports benefits from both medications and from exercise, and highlights some of the difficulties in making these comparisons (such as ensuring equivalent samples, and quantifying exercise uniformly). They also note that exercise is more easily accessible - no appointments or prescriptions are necessary (although anyone beginning a new exercise program is advised to seek medical consult, first).
Remember, though, that there are health benefits to exercise that extend beyond individual physiological systems, and that many of the benefits are somewhat intangible (improved mood, improved decision-making, social benefits). Studies like this are good reminders that we too easily forget the power of exercise, and the power we already hold to improve our own health.
Perhaps Nike put it best in their advertisements from a few years ago: just do it.
See you on Tuesday -
Dr. Nealen
(originally posted 16 Mar 2019)
Good morning all,
I hope that you have had an excellent Break, and are ready for the second half of our term!
We will begin our third unit of the semester with consideration of the cardiac and pulmonary systems. There is much in our upcoming chapters that will be familiar (we all have some inherent understanding of how these systems function) and important (cardiovascular pathology is a leading contributor to human morbidity and mortality). Health science research and news is dominated by several major fields, including cancer, infectious disease, and cardiopulmonary health, for they are at the forefront of what ails us.
One critical feature of our cardiac and pulmonary function is its malleability - we have real power to change how these systems perform, through our habits. Lack of exercise and poor lifestyle choices (in terms of diet, tobacco use, alcohol/drugs) plague too many of us, and a large component of the pharmaceutical industry is geared toward making medications that influence our cardiovascular and pulmonary health. But, we already hold the power to improve our condition, through exercise. Exertion is a form of physiological stress, and (within reason), it is a useful stress - our tissues respond to extra use with improved effectiveness. But, the temptation to simply 'pop a pill', or the lack of available time for exercise, makes it difficult for most of us to meet fitness goals (such as 150 min of moderate exercise per week).
Are these options equivalent? Here's a link to a recent study that makes this type of comparison: are medications or exercise better for treating/managing high blood pressure and body fat stores?
https://www.nytimes.com/2019/03/13/well/move/exercise-vs-drugs-to-treat-high-blood-pressure-and-reduce-fat.html
This study reports benefits from both medications and from exercise, and highlights some of the difficulties in making these comparisons (such as ensuring equivalent samples, and quantifying exercise uniformly). They also note that exercise is more easily accessible - no appointments or prescriptions are necessary (although anyone beginning a new exercise program is advised to seek medical consult, first).
Remember, though, that there are health benefits to exercise that extend beyond individual physiological systems, and that many of the benefits are somewhat intangible (improved mood, improved decision-making, social benefits). Studies like this are good reminders that we too easily forget the power of exercise, and the power we already hold to improve our own health.
Perhaps Nike put it best in their advertisements from a few years ago: just do it.
See you on Tuesday -
Dr. Nealen
Neuroscience Readies for a Showdown Over Consciousness Ideas
(originally posted 10 Mar 2019)
Good morning everyone,
In our recent chapters, we have been considering aspects of nervous system structure and function. During our discussions, we noted that the cerebral cortex of the forebrain is responsible for our "higher" functions, including emotion, reasoning, and planning. Many would argue that these are uniquely human, or at least developed to a higher degree in humans than in any other animal.
Chief among these "higher" functions is that of consciousness. Consciousness has been described as a form of "meta-awareness" (literally, being aware that we are aware). While there are many aspects of neural function that we still do not understand, the neural basis for consciousness is generally agreed to be the most challenging. In fact, consciousness is often described as "the hard problem" of neuroscience, which is a way of saying that it is so poorly understood that we do not really know even how to begin study of it, let alone explanation of it.
As our tools and our thinking are refined, however, more and more investigators are willing to study consciousness. In doing so, they often invoke aid from philosophers and psychologists, for not only is consciousness the ultimate emergent property, it cannot be isolated from itself - we are consciously trying to study consciousness, and that has significant implications for our approaches and our interpretations.
I'm passing along here a link to a recent news article describing (perhaps) a new way of thinking about consciousness, and the study of it. It describes the work of a number of the most prominent neuroscientists working today (including Giulio Tononi, Cristof Koch, and Stanislas Dehaene). This article describes some of the modern techniques used to study consciousness, and also presents some specific models for how consciousness may occur. In doing so, it also offers some specific predictions that might be tested, which will allow us to evaluate which models may, or may not, be plausible.
If you are interested in the "brain-mind" problem, as it is called, you might enjoy this article.
https://www.quantamagazine.org/neuroscience-readies-for-a-showdown-over-consciousness-ideas-20190306/
Hope that your Break is a good one!
Dr. Nealen
(originally posted 10 Mar 2019)
Good morning everyone,
In our recent chapters, we have been considering aspects of nervous system structure and function. During our discussions, we noted that the cerebral cortex of the forebrain is responsible for our "higher" functions, including emotion, reasoning, and planning. Many would argue that these are uniquely human, or at least developed to a higher degree in humans than in any other animal.
Chief among these "higher" functions is that of consciousness. Consciousness has been described as a form of "meta-awareness" (literally, being aware that we are aware). While there are many aspects of neural function that we still do not understand, the neural basis for consciousness is generally agreed to be the most challenging. In fact, consciousness is often described as "the hard problem" of neuroscience, which is a way of saying that it is so poorly understood that we do not really know even how to begin study of it, let alone explanation of it.
As our tools and our thinking are refined, however, more and more investigators are willing to study consciousness. In doing so, they often invoke aid from philosophers and psychologists, for not only is consciousness the ultimate emergent property, it cannot be isolated from itself - we are consciously trying to study consciousness, and that has significant implications for our approaches and our interpretations.
I'm passing along here a link to a recent news article describing (perhaps) a new way of thinking about consciousness, and the study of it. It describes the work of a number of the most prominent neuroscientists working today (including Giulio Tononi, Cristof Koch, and Stanislas Dehaene). This article describes some of the modern techniques used to study consciousness, and also presents some specific models for how consciousness may occur. In doing so, it also offers some specific predictions that might be tested, which will allow us to evaluate which models may, or may not, be plausible.
If you are interested in the "brain-mind" problem, as it is called, you might enjoy this article.
https://www.quantamagazine.org/neuroscience-readies-for-a-showdown-over-consciousness-ideas-20190306/
Hope that your Break is a good one!
Dr. Nealen
Nanotechnology makes it possible for mice to see in infrared -- ScienceDaily
(originally posted 03 Mar 2019)
Good morning all,
As I scan the science news each day, I often read articles that are interesting, and potentially useful. Less frequently do I encounter news reports that make me say 'wow!". Here is one that did.
You will recall from our sensory systems chapter that the photoreceptors in our eyes exist in several forms, and that each form is able to interact with light of some defined frequency range. Together, they give us our vision in the range of light frequencies known as "visual light". Many other organisms can detect light frequencies outside of our visual range, including infrared and ultraviolet.
This news report describes a recent advance that marries technology and neuroscience (two of my favorite topics). Here, scientists have developed molecules that act as intermediates between the light entering the eye and the light striking the photoreceptors. These molecules harvest light of one frequency, and emit it at another (the phenomenon of fluorescence). In this case, they have been designed to harvest a light frequency normally unavailable to us (and to mice), and to then emit it at a frequency to which our photoreceptors are sensitive. The effect is to allow vision under light frequencies which are not normally useful to us.
As the article notes, these experiments only have been performed in mice, to date. But, you can be sure that human applications are coming. I think that they will have to build-in some sort of kill-switch, first - a way to get rid of the molecules should they prove problematic. My guess is that they are already working on it...
Wow!
https://www.sciencedaily.com/releases/2019/02/190228141412.htm
Have a great rest of the weekend -
Dr. Nealen
(originally posted 03 Mar 2019)
Good morning all,
As I scan the science news each day, I often read articles that are interesting, and potentially useful. Less frequently do I encounter news reports that make me say 'wow!". Here is one that did.
You will recall from our sensory systems chapter that the photoreceptors in our eyes exist in several forms, and that each form is able to interact with light of some defined frequency range. Together, they give us our vision in the range of light frequencies known as "visual light". Many other organisms can detect light frequencies outside of our visual range, including infrared and ultraviolet.
This news report describes a recent advance that marries technology and neuroscience (two of my favorite topics). Here, scientists have developed molecules that act as intermediates between the light entering the eye and the light striking the photoreceptors. These molecules harvest light of one frequency, and emit it at another (the phenomenon of fluorescence). In this case, they have been designed to harvest a light frequency normally unavailable to us (and to mice), and to then emit it at a frequency to which our photoreceptors are sensitive. The effect is to allow vision under light frequencies which are not normally useful to us.
As the article notes, these experiments only have been performed in mice, to date. But, you can be sure that human applications are coming. I think that they will have to build-in some sort of kill-switch, first - a way to get rid of the molecules should they prove problematic. My guess is that they are already working on it...
Wow!
https://www.sciencedaily.com/releases/2019/02/190228141412.htm
Have a great rest of the weekend -
Dr. Nealen
Split and continuous sleep in teens impact cognition and glucose levels differently -- ScienceDaily
(originally posted 23 Feb 2019)
Good morning, to all of you early birds -
We all probably have trouble fitting everything into our busy schedules, and sometimes our sleep is shortchanged. Do you get enough sleep? Is one long bout of sleep better than two shorter bouts? Why do we need to sleep, anyway?
These are just a few of the many interesting questions about sleep, and scientists are tackling them, one small step at a time. One recent study (link below) suggests that, if you can't get a full 9 hrs of overnight sleep, having an early nap followed by a relatively short overnight sleep may, in fact, not be so bad.
https://www.sciencedaily.com/releases/2019/02/190222101312.htm
Have a great weekend -
Dr. Nealen
(originally posted 23 Feb 2019)
Good morning, to all of you early birds -
We all probably have trouble fitting everything into our busy schedules, and sometimes our sleep is shortchanged. Do you get enough sleep? Is one long bout of sleep better than two shorter bouts? Why do we need to sleep, anyway?
These are just a few of the many interesting questions about sleep, and scientists are tackling them, one small step at a time. One recent study (link below) suggests that, if you can't get a full 9 hrs of overnight sleep, having an early nap followed by a relatively short overnight sleep may, in fact, not be so bad.
https://www.sciencedaily.com/releases/2019/02/190222101312.htm
Have a great weekend -
Dr. Nealen
Brain-zapping implants that fight depression inch closer to reality | Science News
(originally posted 16 Feb 2019)
Good morning all,
In our last lecture, we discussed the characteristics of neurons, and how they use electricity (specifically, changes in membrane potential) to send information to their targets. Many of our BIOL 240 lab sections this week explored this concept via EEGs (electroencephalograms), which are recordings of skin potentials that occur due to changes in brain electrical activity.
I also mentioned in lecture that many of our pharmaceuticals are designed to chemically influence neural function. You may also know that electrical manipulation of the bran is not far behind. Scientists have known about the electrical properties of nervous tissue for many decades, and in recent years, we have been able to apply this knowledge to stimulate the brain.
Rather than using electrodes to measure the electricity coming from the brain, what if we use them to apply electricity to it? As you would expect, we can cause neurons to become activated by passing electrical current over them.
There are many different forms of neural stimulation possible, from very local applications to nearly whole-brain methods. Increasingly, we are getting better at using small-scale, focal stimulation to apply electricity at select locations, in order to change the function of circuits in that area. Below is a link to a recent report of one such use of this method.
Think about all of the different aspects of our behavior, emotions, and performance that are controlled neurally. What if we could adjust them, with a battery?
https://www.sciencenews.org/article/brain-electric-implants-treat-depression-closer-reality
Have a great weekend -
Dr. Nealen
(originally posted 16 Feb 2019)
Good morning all,
In our last lecture, we discussed the characteristics of neurons, and how they use electricity (specifically, changes in membrane potential) to send information to their targets. Many of our BIOL 240 lab sections this week explored this concept via EEGs (electroencephalograms), which are recordings of skin potentials that occur due to changes in brain electrical activity.
I also mentioned in lecture that many of our pharmaceuticals are designed to chemically influence neural function. You may also know that electrical manipulation of the bran is not far behind. Scientists have known about the electrical properties of nervous tissue for many decades, and in recent years, we have been able to apply this knowledge to stimulate the brain.
Rather than using electrodes to measure the electricity coming from the brain, what if we use them to apply electricity to it? As you would expect, we can cause neurons to become activated by passing electrical current over them.
There are many different forms of neural stimulation possible, from very local applications to nearly whole-brain methods. Increasingly, we are getting better at using small-scale, focal stimulation to apply electricity at select locations, in order to change the function of circuits in that area. Below is a link to a recent report of one such use of this method.
Think about all of the different aspects of our behavior, emotions, and performance that are controlled neurally. What if we could adjust them, with a battery?
https://www.sciencenews.org/article/brain-electric-implants-treat-depression-closer-reality
Have a great weekend -
Dr. Nealen
Pills equipped with tiny needles can inject a body from the inside | Science News
(originally posted 09 Feb 2019)
Good morning everyone,
I'm sending along two links to one of the more-interesting pieces of science news this week: a medical device that diabetic patients could swallow and which would provide their injections of insulin internally. While not yet ready for human use, a device of this type could be a great aid to people who tire of, or are fearful of, giving themselves injections:
https://www.sciencenews.org/article/pills-needles-injection-medication
http://www.sciencemag.org/news/2019/02/pills-armed-tiny-needles-could-inject-insulin-other-important-meds-directly-stomach
Have a good weekend -
Dr. Nealen
(originally posted 09 Feb 2019)
Good morning everyone,
I'm sending along two links to one of the more-interesting pieces of science news this week: a medical device that diabetic patients could swallow and which would provide their injections of insulin internally. While not yet ready for human use, a device of this type could be a great aid to people who tire of, or are fearful of, giving themselves injections:
https://www.sciencenews.org/article/pills-needles-injection-medication
http://www.sciencemag.org/news/2019/02/pills-armed-tiny-needles-could-inject-insulin-other-important-meds-directly-stomach
Have a good weekend -
Dr. Nealen
How to Avoid Frostbite and Hypothermia in Extreme Cold Weather - The New York Times
(originally posted 31 Jan 2019)
Good morning everyone,
I'm passing along here a reminder of the dangers of hypothermia and frostbite, which includes description of some of the physiological challenges extremely cold temperatures place on the body. Seems appropriate this week!
https://www.nytimes.com/2019/01/29/health/frostbite-hypothermia-cold-weather.html
Just remember, Spring is only about 7 weeks away ;-)
Dr. Nealen
(originally posted 31 Jan 2019)
Good morning everyone,
I'm passing along here a reminder of the dangers of hypothermia and frostbite, which includes description of some of the physiological challenges extremely cold temperatures place on the body. Seems appropriate this week!
https://www.nytimes.com/2019/01/29/health/frostbite-hypothermia-cold-weather.html
Just remember, Spring is only about 7 weeks away ;-)
Dr. Nealen
Your Sweat Will See You Now
The New York Times - posted 26 Jan 2019
Good morning all,
I'm passing along here a link to a recent news article about a a new, wearable device for assessing physiological condition. This type of instrument is only made possible through the application of advanced electronics and engineering to health issues, a trend that is only going to increase over time. While these devices are exciting and interesting, remember also that there is risk associated with their use, in the collection/banking of your personal health data, and the need to safeguard one's privacy.
I will occasionally pass along articles of this type during the semester. My purpose in doing so is to help you to become more aware of current physiology and health topics, and also to help you assess how you obtain your science and health news.
Those of us working in science obtain our scientific news, quite often, directly form the original sources: the people conducting the studies and reporting the results. They publish their findings in science journals, or present them at conferences.
Most people do not obtain their news directly, but hear news via secondary sources, such as news releases from scientific organizations, or news stories from the major news outlets. These secondary reports often are then carried by tertiary outlets (smaller/other reporting sources).
Along the way from source to audience, science news is normally distilled (a lot) - much of the detail is excluded or simplified, and the reports often are boiled-down to singular take-home messages, which may (or may not) be good representations of the original work.
When you browse the links that I will forward, or when you access science and health news on your own, I'd encourage you to delve a little bit deeper into them, to read more than just the summaries, and to follow links back to original sources when possible. I'd also encourage you to think a little about the translation of news from source to consumer, and the reputability of the news outlets that you use.
None of these news links that I send you will be represented on our course exams, but I do hope that the material in them makes its way into our physiology conversations. I'm sending this link to both my BIOL 240 lecture and lab sections, so my apologies if you receive this message twice.
This first link is from the New York Times, which provides one of the best (e.g., best funded and most reliable) secondary sources of science and health news. They do limit access to only a handful of free articles each month, so I will use them sparingly.
https://www.nytimes.com/2019/01/18/health/wearable-tech-sweat.html
Have a great weekend -
Dr. Nealen
The New York Times - posted 26 Jan 2019
Good morning all,
I'm passing along here a link to a recent news article about a a new, wearable device for assessing physiological condition. This type of instrument is only made possible through the application of advanced electronics and engineering to health issues, a trend that is only going to increase over time. While these devices are exciting and interesting, remember also that there is risk associated with their use, in the collection/banking of your personal health data, and the need to safeguard one's privacy.
I will occasionally pass along articles of this type during the semester. My purpose in doing so is to help you to become more aware of current physiology and health topics, and also to help you assess how you obtain your science and health news.
Those of us working in science obtain our scientific news, quite often, directly form the original sources: the people conducting the studies and reporting the results. They publish their findings in science journals, or present them at conferences.
Most people do not obtain their news directly, but hear news via secondary sources, such as news releases from scientific organizations, or news stories from the major news outlets. These secondary reports often are then carried by tertiary outlets (smaller/other reporting sources).
Along the way from source to audience, science news is normally distilled (a lot) - much of the detail is excluded or simplified, and the reports often are boiled-down to singular take-home messages, which may (or may not) be good representations of the original work.
When you browse the links that I will forward, or when you access science and health news on your own, I'd encourage you to delve a little bit deeper into them, to read more than just the summaries, and to follow links back to original sources when possible. I'd also encourage you to think a little about the translation of news from source to consumer, and the reputability of the news outlets that you use.
None of these news links that I send you will be represented on our course exams, but I do hope that the material in them makes its way into our physiology conversations. I'm sending this link to both my BIOL 240 lecture and lab sections, so my apologies if you receive this message twice.
This first link is from the New York Times, which provides one of the best (e.g., best funded and most reliable) secondary sources of science and health news. They do limit access to only a handful of free articles each month, so I will use them sparingly.
https://www.nytimes.com/2019/01/18/health/wearable-tech-sweat.html
Have a great weekend -
Dr. Nealen
'A devastating blow to the reputations of some of the biggest names in British sport'
(BBC Sport - posted 05 Mar 2018)
Good morning all,
As we prepare for a lab on 'doping' this week, a related news article has crossed my desk this morning:
http://www.bbc.com/sport/43281807
It is good to see that our topics are relevant and timely!
See you on Wed -
Dr. Nealen
(BBC Sport - posted 05 Mar 2018)
Good morning all,
As we prepare for a lab on 'doping' this week, a related news article has crossed my desk this morning:
http://www.bbc.com/sport/43281807
It is good to see that our topics are relevant and timely!
See you on Wed -
Dr. Nealen