Monday, February 27, 2012
Sun: hero or villain?
Saturday, February 25, 2012
Moalem's Evolutionary Tales
The portion of Moalem's book that I believe to be most interesting is the second chapter, "A Spoonful of Sugar Helps the Temperature Go Down." Specifically, I enjoyed his discussion on the wood frog, Rana sylvatica, the connoisseurs of cryopreservation. At first, it may not seem like a huge deal that these wood frogs are able to sustain an unconscious, frozen state throughout the winter and revamp their metabolism come spring. How might this adaptation, however, be an invaluable tool for human beings? First, the ability to revitalize living organisms that have been preserved at very low temperatures, has enabled scientists and doctors to store banks of eggs and sperm that, when unfrozen, maintain the full capacity to be fertilized and develop into viable embryos. Taking this concept to the next step is what I find particularly exciting - can this sort of technology allow us to preserve entire organs that can be stored and used for transplants? At current, unfortunately, no. However, I think that this sort of technology will one day be sophisticated enough to allow for long term preservation of human organs. Moaelem describes the various features of the wood frog and suggests the possibility that these characteristics be used to develop strategies for human organ preservation. For example, the wood frogs essentially diminish their water supply and shoot up their glucose levels in preparation for their deathlike winter. To carry this idea further, I think it would be interesting to sequence the genome of this frog, with the hopes that the genetic makeup for this adaptation may somehow be able to be utilized in order to manipulate the ability of human organ to hibernate. The development of such technology would change the face of medicine forever, as it would increase survival rates for patients suffering from terminal illnesses, such a cancer or heart disease, who require organ replacement in order to live.
Dr. Moalem's Theory applied to Bacteria Infecting Viruses
Epigenetics
“The mothers’ gentle attention somehow triggered the removal of methyl markers that would otherwise have blocked or impeded the development of a part of their babies’ brains—almost as if they were licking them off. The part of the brain that dampened the stress response was more developed in those babies. This wasn't nature versus nurture’ this was nature and nurture.” (169)
This is an interesting case to look at. It shows how nature and the environment influence biology. To me, this doesn't seem like such a big shock. I view nature and nurture as in a complex relationship, not as two separate entities. However, apparently this idea is in fact shocking enough that, “One reviewer at a prominent journal actually went so far as to write that, despite the researchers’ carefully marshaled evidence, he refused to believe it could be true” (169). Does anyone want to comment on why the researcher found this evidence to be so incredibly problematic as to not even believe it?
****UPDATED*****
I just found this really interesting study which claims that women can produce NEW eggs during her lifetime. This is a really interesting idea in light of some of the above cases as well as medicine in general! I didn't get a chance to look into it too extensively, but it certainly has vast implications for many of the theories we have been discussing in class. Take a look!
Survive and Reproduce
It amazed me to realize how many other little microscopic organisms coexist in our bodies. While I was aware of their existence, mostly every time I got sick, it never hit me until reading Survival of the Sickest. Sharon Moalem reveals, “not only do these former bacteria live in almost all your cells, they even have their own inheritable DNA” (129). This reminded me how in the introduction he mentions that even laying on our bed there are thousands of living organisms around and inside of you. It scared me to realize that some of these microbes can alter one’s nervous system, through host manipulation, in order to survive and reproduce. It is not like as if they are hijacking our nervous system and completely changing it but rather they manipulate it for their own survival. These microbes can be harmless in some but may be harmful for others. Moalem states that some scientist hypothesizes that T. gondii may trigger schizophrenia in people. It that is confirmed then we will be able to find a way to treat those with schizophrenia. Nevertheless, I still find it shocking that little microbes can affects us not only physically but also mentally.
Each organism’s goal is for survival of their gene’s and reproduction. Moalem mentions that if we figure out the ways parasites spread and we find ways to impede this spreading, like cleaning up the water systems or putting up mosquito nets, they will become less deadly to the host because it is harder for them to spread and infect others. What confuses me is how do they know that their means of reaching other hosts is thwarted and how can they tell that they need to stay in this host longer in order to survive? Moalem mentions that they do not have brains, and I do not believe that they can see things in a grand scale, so how is it that using these preventative methods stopping them? I suppose they can realize that they are not spreading pathogens to other host but without a brain how is that possible?
Mental Illness: Also Advantageous?
Considering the way of thinking presented in this text, I couldn't help but expand Moalem's idea to include mental illness as also having it's silver linings. I know that I am getting away from the principle thesis that disease may increase longevity, but I would like to discuss how mental illness may actually increase chances of success for individuals in a more general way. My first example of this idea is John Nash, the mathematician responsible for the now widely used game theory. There are many books and films about Nash, including the Oscar gobbler A Beautiful Mind, but one which I feel is much more relevant to my discussion is a documentary by PBS: A Brilliant Madness. The focus of these films is that, in addition to his breakthroughs in mathematics, Nash also suffered from (spoiler alert) advanced paranoid schizophrenia. In the documentary, Nash states that he felt great pressure from this disorder, as he often felt that he was some divine messenger because of his ideas. He states in these interviews that, as a result of this part of his condition, "I wouldn't have had good scientific ideas if I thought normally" and "If I had felt completely pressureless I don't think I would have gone in this pattern." Part of this interview is transcribed here. Nash's schizophrenia, while distancing himself from his family and effecting his everyday life, certainly played a huge part in his success in life.
Other examples include Jimi Hendrix, whose battles with manic depression influenced much of his work. Another example includes football great Herschel Walker, who, it was found when his career had finished, had a severe and rare form of mental illness now known as dissociative personality disorder (previously multiple personality disorder). In this video, Walker explains that his different identities would take on different roles, a father, a husband, a football player, a business man. He recognizes this as a blessing to his wild success in athletics, but also a curse as he does not know who he really is. If you are more interested in this, there is an incredible special that ESPN did called "Herschel" where he describes in detail what his different "alters" were like.
I realize that this may be a touchy issue, but I just don't think I would have thought about any of this if it hadn't been for this book.
Survival of the Sickest
For my blog post, I'd like to specifically examine how Dr. Moalem breaks down the importance of iron in the human body. The traditional understanding of iron is that it is one of the most important compounds used by the human body. It is required for "nearly every function of our metabolism", including the transportation of oxygen in our bloodstream and the conversion of sugar into energy. For many years, doctors and nutritionists "operated under the assumption that more iron can only be better", but more recent research shows that this is far from the truth. In fact, many of the parasites, cancer cells, and bacteria that assail our bodies thrive on iron, and adding too much iron to our bodies is simply providing more food for these assailants.
This key revelation is one of the central themes to Dr. Moalem's book. She wants us to consider disease from the standpoint of evolution - how is it that these certain genes have persisted in our DNA through all these years? For many years, we operated under the assumption that more iron could only be better for our bodies, but we failed to realize that if our own bodies require iron, then certain bacteria, fungi, and viruses would be extremely iron-hungry as well. I believe that the most valuable message that Dr. Moalem is trying to put forth is similar to what Robert Sapolsky was arguing in his book about stress, in order to understand disease and illness, we must utilize a perspective that incorporates all of the various factors, including other organisms and evolution.
Benefits of Disease?
While reading the second half of “Survival of the Sickest,” I stumbled across a passage in the book that reminded me of the first book we read, “The Starting Gate: Birth Weight and Life Chances.” On page 159, there is a reference to a study done at Duke about how, “nutritional supplementation to the mother can permanently alter gene expression in her offspring without altering the genes themselves.” This discovery heavily impacts the debate we had earlier about if low birth weight has to do more with genetics or the state of health of the mother during pregnancy (favoring the health of the mother during pregnancy).
I found it interesting that certain diseases that ail us today helped with the survival of our ancestors. I already knew before that even though bacteria, usually seen as nuisances that cause disease, are necessary for us to process certain foods and provide us with vitamins that we cannot get ourselves. However, I was unaware there were actually diseases such as diabetes that improved the chances of survival in the past but are now a cause of death in the present. His theories seem to be plausible but I find it hard to believe that they tell the whole story. For example, when he talks about men being more susceptible to catch the bubonic plague than women can be accounted for in ways beyond just the iron deficiency in women. Since the bubonic plague was a contagious disease, men could have been more likely to catch it because they spend more time out of the house around others since they were the ones that worked. Women during those days spent more time at home, away from the public giving them less of a chance to be exposed to those with the disease outside their family members. Besides that example, his other arguments seem very plausible and quite fascinating. After reading this book, I now wonder if there is something comprising our bodies today that will be seen as a disease in the future.
Monday, February 20, 2012
Evolution and Diseases
Sunday, February 19, 2012
Iron / Living Things
Saturday, February 18, 2012
Survival of the sickest?
Survival of The Sickest
Does medicine influence evolution?
Maybe Being Anemic Isn't so Bad, but It Probably Is
Biology or Sociology?
Genes aren't what they used to be
The Survival of the Sickest by Dr. Sharon Moalem takes a look at different genetic issues and diseases and attempts to connect these issues to evolutionary factors and the history of the human race. The book presents how some disease that still effect us today like diabetes or even hemochromatosis are side effects of our evolution and although are troublesome today, were methods of survival for environmental issues like Younger Dryas and the plague.
What I found interesting was his link of hemochromatosis, an excess of iron in the blood, to Northern European survival to the plague. Apparently, those suffering from this issue have a lack of iron in their macrophages which causes their immune system to be able to better combat bacteria. Those with the genetic mutation were more likely to survive the mutation and pass this trait on to their offspring. Certain environmental factors may cause traits to be more beneficial at a specific time than others, causing a sort of natural selection in humans to continue the lineage of those with a predisposition to beat whatever environmental threat in going on. He creates this same argument for diabetes and the great freeze that took places thousands of years ago, and how this trait that didn’t break down sugar gave the body antifreeze in this environmental time.
Additionally, the same goes for bacteria. They also when given a threatened environment have a sort of natural selection. The book notes that when penicillin was discovered, at first it treated staph, but eventually a percentage of staff infections were penicillin resistant. Just as humans were able to adapt to their harsh surroundings and reproduce offspring with genes for survival, so have bacteria. Just as we can use evolution to discover that natural selection has taken place so that species may survive and reproduce, we must also use that information to understand that by attacking bacteria in certain ways may speed along their natural selection evolution. Ewald was cited in this book stating that we should take control of their evolution by “favoring those mild strains and thereby domesticating those disease organisms, making them into mild versions of what they were before” (121). Through knowing our own history and evolution we should do what we can to not make bacteria stronger but to treat them in a way that would produce weaker versions of themselves.
The book through its examples of high cholesterol, hereditability, the Barker Hypothesis and others, what I gained from this book is that the human body is a complex system driven by primal forces to survive and reproduce. Only when we trace what genes our ancestors used to survive in their harsh environment do these genes seem to be beneficial for us humans. Although we may understand some of nature and how our biological system works, the way in which we live our lives may not be the most beneficial. Just as what stress today isn’t dealt the same way as the Zebra running from the lion, certain issues in our body that could have been beneficial for us in the Savannah may not be as beneficial in the modern realm.
Sunday, February 12, 2012
Zebras, Lions, and Humans? Interesting Mix
Animals stress over things too. They have to worry about providing for their families, and if they are going to fall prey to another mammal higher up on the food chain, or if they are going to have something to eat tonight or somewhere to sleep. But animals have less chance of repeatedly, constantly worrying about these things. They are more of spur-of-the-moment occurrences and will likely be forgotten soon after. That is one of the main reasons that animals like that usually do not get serious side effects of stress like we do. However, if constant stress is placed on an animal, such as the stress that is placed on humans, than it is likely that the animal will experience an ulcer or something of the sort. For example, Sapolsky mentions a study that was done on a rat. The rat was frequently tossed around, forced to run back and forth and had it fight for its life. After the stress and exhaustion the rat experienced, tests were ran on it and they showed that the rat had a peptic ulcer.
Sapolsky is trying to make the point that in any of our organs in our body, stress can cause diseases to form inside of them. The same occurs in animals that experience the same stressful events. What shocked me was that social stress alone can cause the greatest damage in the blood vessels and arteries. Plaque can form and build up from the drama of not being accepted socially. The same was true for monkeys experiencing the same thing. The study showed that monkeys figure out where they stand socially with others of the same species very quickly and if this is not good to them then they get upset and stressed. The causes of hypertension and atherosclerosis come from this. Who knew that social stress could eventually cause so much harm?
Saturday, February 11, 2012
Crazy Mind Causes Crazy Body
Save Us, George Clooney
Examples of stressors include the ending of a relationship, losing a job, or an approaching exam. The way our bodies react to these stressors is what makes us vulnerable to disease, and that got me thinking about ways that these stressors might be made less stressful. Personally I think that losing one's job is an extremely stressful event, in fact it has been put on par with the death of a family member in terms of stress. George Clooney in the film "Up in the Air" plays a consultant whose job is to go into a company that is downsizing and fire people. I'm not about to suggest that companies get Hollywood A-listers to fire people to smooth things over, stay with me. Part of the process is that Clooney gives everyone who is being fired a packet with information about what to do next, including references and good ideas about where to go next for employment. While many companies do things like this already without a third party, I think it is extremely important, particularly in light of discoveries about the impact of stress on one's health, to create ways to make a stressful event like being fired as painless and hopeful as possible, for the good of the employee and the work force as a whole. Happy, healthy workers do good work.
Another interesting idea about how to reduce stress with stressors (probably a better way to say that) is this Dutch hotel, who is offering a service that allows couples to go through the entire process of a divorce in just a couple of days, rather than dragging the process out for months and months. This seemed relevant to me because of Sapolsky's statement that what makes stress so bad is how long it can last, and perhaps something like this would be extremely useful to couples looking to divorce. Not very festive with Valentine's Day coming up, but I hope you found it as interesting as I did.
Intersections of Biology and Sociology
Mind Over Matter?
I would like to focus on the interesting topic of "mind over matter" and the ever-present problem of placing too much emphasis on one factor over another. It can be an incredibly helpful thought that our minds can control our physiological state and can be empowering for those who feel they do not have control over their biology or have the exact opposite example.
One really interesting example I found of this is the yoga/meditation technique called Tum-mo that has been studied for its affect on physiological state. Here is the link to an article from the Harvard Gazette (from 10 years ago) about a study done by Herbert Benson on Tibetan monks practicing Tum-mo. Benson states (in the above article) that he is interested in studying advanced forms of meditation since he believes that they, "can uncover capacities that will help us to better treat stress-related illnesses".
This idea I think is interesting to think about in relation to this whole big book about stress-related illnesses. He has developed the "relaxation response" which is essentially the opposite physiological state of stress and, "it is characterized by decreases in metabolism, breathing rate, heart rate, and blood pressure". I thought this was interesting in light of the book. Any thoughts on his idea?
Also, he said in the article that he was planning on trying it out again the following winter. However, I was unable to find (if anyone wants to try looking, feel free to do so and share!) information about another attempt. I did however when looking him up find that he has since then written somewhat extensively on the health benefits of prayer.
Another interesting case is that of Wim Hof known as the "Ice Man" who essentially runs shoeless and shirtless in freezing temperatures and attributes this ability to his practice of Tum-mo. Here is a discovery channel video about him (I didn't watch all of it, but if you are interested in his story check it out). Hof (who holds 18 world records) has climbed Kilamanjaro in 2 days wearing only his shorts and can remain immersed in a bath of ice for 1 hour and 44 minutes. He also published a book recently (November 2011) called, Becoming the Iceman.
If anyone is interested in reading more about scientific studies of Tum-mo (including Benson's actual study)
Benson et al. (1982) Body temperature changes during the practice of g Tum-mo yoga., PDF: http://lib.semi.ac.cn:8080/tsh/dzzy/wsqk/Nature/295-234.pdf
Ding-E Young, John and Taylor, Eugene (1998) Meditation as a Voluntary Hypometabolic State of Biological Estivation, PDF: http://physiologyonline.physiology.org/content/13/3/149.full.pdf
That was the mind over matter is awesome and super cool portion. Now here comes the negative side. The book mentions Bernie S. Siegel and his book, Love, Medicine and Miracles (New York: Harper & Row, 1986). The main point of the book is that, "the most effective way of stimulating the immune system is through love, and that miraculous healing happens to patients who are brave enough to love" (178). Sapolsky explains quite well what the problem with this view is:
"No matter how often he puts in disclaimers saying that he's not trying to make people feel guilty, the book's premise is that (a) cancer can be caused by psychosocial factors in the person; (b) cancer (or any other disease, as far as I can tell) is curable if the patient has sufficient courage, love, and spirit; (c)if the patient is not cured, it is because of insufficient amounts of those admirable traits. As we have just seen, this is not how cancer works, and a physician simply should not go about telling seriously ill people otherwise" (179).
This is an incredibly dangerous viewpoint that can essentially have the disempowering effect of making patients feel responsible for their illness. Illness can be incredibly stressful and this blames those who aren't getting better and accuses them of not having the right attitude to get better. There are plenty of people who have the 'right' attitude but don't get better and this could make them feel defeated.
There is obviously a lot more about this that could be said, but, I wrote way more than 300 words and would rather hear what other people have to say about it.
Stress Always a Bad Thing?
“Why Zebras Don’t Get Ulcers” by Robert M. Sapolsky is a fascinating book that talks about the affects of stress on the human body and all the stress related diseases that harm our health. Sapolsky points out that humans are not meant to live in cities but instead in the wild where our stress responses would be detrimental to our survival. Instead, our bodies have to consistently recover back to the homeostatic balance after a stress response, which tends to harm the body. Before reading this book I knew that studies show that stress has a good deal to do with ulcers but I did not know it contributed to so many other diseases.
Sapolsky has gained a great deal of his knowledge on the effects of stress by studying wild animals in Africa. One quote from the book that I found interesting was that humans “can get stressed simply with thought, turning on the same stress response as does the zebra.” He further states that no other primate can get stressed by thought. How we were able to develop the ability to get stressed out by thought is the first time I heard of a bad side effect from our increase in intelligence throughout the centuries. He does state that maybe if humans were smart enough to develop it maybe we will be able to find a way to get rid of it. However, I believe that even though stress may hinder our body, it is also something that motivates us and helps us complete our responsibilities. Of course I do not believe stress on a large-scale basis is good because I do know of many people that suffer from anxiety. But, when controlled, I believe that stress can be a good thing that helps our efficiency and keeps us on track.
Stress
Until reading Robert M. Sapolsky's Why Zebras Don't Get Ulcers, I did not realize how easily stress and its detrimental effects plague us. Just with our thoughts and not moving a muscle, we can mess with our body's homeostasis. Our thoughts can trigger our organs to secrete hormones as a response to the stressor and spark a chain reaction of responses throughout our body. I used to always attributed stress as a good thing which helps push and motivate me. However, the book proves to us that perpetually being in a stressful state is bad for our health in the long run. This shows that while a short-term stress may be healthy, constantly being stressed and worried is not good for us. It surprised me to read that due to stress our immunity will be inhibited and our body will delay in finding things such as tumor cells and delay producing antibodies to protect us. The stress response can be more harmful than stress itself. A stressful thought can be likened to a prey running away from its hunter. It puts our bodies into overtime and can affect us by causing the blood to rush through our veins and arteries creating more muscles around these blood vessels, which is bad for us and may cause cardiovascular diseases for us in the future. Regardless, sometimes there are people who may go through the same stressful situation but some of them may not develop a cardiovascular disease due to their personalities and some may already have a damaged cardiovascular system which the stress will hurt them more. It was also interesting to see that when woman produce estrogen at a younger age, it is more likely to protect them against cardiovascular diseases. I find it really interesting that our body has unique responses to certain situations but long-term stress will have harmful repercussions.
Stress and Memory
structure of glucocortiod |
Perhaps the most interesting part of stress-induced memory disruption is the brain's ability to highlight emotionally traumatic memories, such as those experienced by an individual with PTSD. While Sapolsky explains that most humans are vulnerable to the negative consequences of stress, I found it particularly intriguing to understand how stress in extreme proportions can have permanently damaging effects on the brain and health.
(Also, there is a PBS called "This Emotional Life," featuring Dr. Sapolsky, that included a segment on PTSD. )
Zebras and Stress
Monday, February 6, 2012
Intergenerational Transmission and Race
One factor that cannot be ignored in this intergenerational research is the race of the child. Race was discussed in this book quite a lot even in the opening chapters. It is a very imminent problem in the research of low birth weight children and begs an answer. How much does race really have to do with the lo birth weight of a child? Race can determine a lot of other factors in the child's life as well, so this is one of the main reasons why researches think it to be so prominent. There was comparison between African American babies and non-African American babies in the first few chapters that touched on why African American babies were an interesting circumstance. There are a lot of African American families, actually more of them who are lower in socioeconomic status than non-african Americans. Even the ones who are middle and high class and very successful were stated to have on average more low birth-weight babies. This discredited the theory that the cause for the low birth weight was the socioeconomic status and the wealth and quality of the jobs that these families had. Although these factors do play a big role. If the family is not living in a great place and it is run down, they do not have steady jobs or good health care, which a lot of African American families don't, then they will not be able to raise a baby, even in the womb, with a healthy, productive lifestyle. There won't be a way for the baby to get good prenatal care and they won't be able to provide for it. However, the book did state that some black babies may just be naturally smaller than white babies are at birth, which would explain the statistic of frequent low birth weight. Black babies may be smaller at all gestational stages (45). Therefore, race does not show any causation, or even a good correlation for low birth weight because a black baby being small does not have the same negative implications for development.