Good morning everyone, In our lab this term, we have talked numerous times about the 'central dogma of information flow', the idea that information encoded in DNA is used during the process of transcription to make RNA, which itself is used during translation to make protein. This concept is part of the 'one gene, one protein' idea, that each gene encodes information to make a single type of protein. During our discussions, we've also used estimates of the number of genes that we possess (perhaps 25,000), and our most recent lab included discussion of how effective any single one of them may be in influencing phenotype. Most individual genes are likely to have little or no obvious effects on phenotype, while some 'master regulator' genes, or other single genes that are responsible for the production of a key molecule in a cell, may exert more-pronounced effects. In the news this week comes description of one such gene (gene FAAH, so called), which had been identified previously but whose function was unknown. It is now known that it is a crucial player in mammalian pain perception, for a woman has been described who has led a 'pain-free' life, and who has a genetic mutation in this one gene. Interestingly, this mutation also influences mood - she is described as never feeling anxiety as well. https://www.livescience.com/65100-woman-cant-feel-pain.html While pain is unpleasant, do not wish for none of it, for it is a useful 'warning system' that alerts us to tissue damage. There have been others described who 'feel no pain', and their existence is pretty awful, for they experience injury after injury (many of them self-inflicted). Much of their story was described in a superb documentary from a few years ago, entitled A Life Without Pain - if you are interested in the topic, it is very worthwhile. The subject in this most recent report is mostly, but not entirely pain-free, so her life is mostly normal. But, her case illustrates well the potential power of individual genes. They need not always be 'master regulators' to have individually-profound effects. Sometimes, being just a single link in an important chain is crucial. Have a great weekend - Dr. Nealen
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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 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 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 Good morning all, I'm sure that you have heard recent news about gene editing that was performed on two human embryos by a Chinese scientist, in an attempt to introduce resistance to HIV infection. His efforts only came to light after the children were born, and have been roundly criticized as 'crossing the bridge too soon' - there seems to have been little or no oversight of his work, and most geneticists agree that it is too early for us to consider human genome editing, before we better understand the risks, and the opportunities, it poses. But, calls for a moratorium on this type of work are not universal - some believe that the time is now to proceed, and that the potential risks of waiting are greater than the potential for doing harm. Others say that this is simply scientific progress - messy, risky, but in the end, advancing our knowledge and capabilities. That this debate is prominent in the science literature is a sign that this is truly the cutting-edge of research and its application. I'm sure that we haven't heard the last on this issue, and I also am sure that in your lifetimes there will be increasing opportunity to perform exactly this kind of genome editing. Think about children you might have in the future - would you edit their genomes to improve their health? Or to make them smarter? Or kinder? What if you could only choose one of these characteristics? What if improving one caused reductions in another? There is still much to learn, and much to discuss... https://www.sciencemag.org/news/2019/03/new-call-ban-gene-edited-babies-divides-biologists?utm_campaign=news_weekly_2019-03-15&et_rid=17390186&et_cid=2717665 Hope that you all have had a great Break, and are ready for the second half of our semester! I have been taking care of our planaria, and they are almost ready for your evaluation. Travel safely back to campus - see you on Wednesday. Dr. Nealen 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 -- ScienceDaily2/23/2019 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 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 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 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 |
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