This Scientific American article delves into the genetic engineering of malaria-resistant mosquitoes in an effort to reduce malaria transmission between vectors and hosts. By injecting an engineered gene into the Anopeheles stephensi mosquitoes’ eggs, Dr. Anthony James and his colleagues were able to breed malaria-resistant mosquitoes that were incapable of transmitting the malaria parasite to humans with a bite. Intriguingly, the engineered gene has been shown to be dominant; consequently, Dr. James and his colleagues believe that releasing the malaria-resistant mosquitoes in strategic locations could potentially reduce transmission rates significantly. This novel development in the field of infectious diseases is particularly significant as many scientists predict that climate change (and increased rainfall) may increase the prevalence of malaria by providing mosquitoes with more breeding sites through puddles. One obstacle to this transmission-reducing method, however, is that researchers would have to generate millions of malaria-resistant mosquitoes and subsequently release them into specific locations at strategic times. While this novel method for reducing transmission rates does face certain obstacles, it could potentially be used to reduce the prevalence of other vector-borne diseases such as dengue fever and the West Nile virus. Consequently, Dr. James’ study has significant implications for the prevention of vector-borne diseases, particularly in areas where access to medical resources may be scarce. This Scientific American article is relevant to the nature of our malaria discussion as we briefly mentioned how scientists have genetically engineered malaria-resistant mosquitoes; as a result, it was interesting to gain a deeper understanding of how researchers have actually accomplished this.

http://www.scientificamerican.com/article/malaria-resistant-mosquitoes-lab-bred-first-time/

The article delves into the evolutionary selection pressures that have shaped the vectorial capacity and competence of Anopheles mosquitoes. Cohuet et al. begin by addressing the impact of parasite virulence on a host’s fitness; in particular, the team narrows down the infection-induced costs to fitness to a reduction in survival or the ability to reproduce. To explain a possible reduction in longevity from Plasmodium infections, Cohuet et al. proposed four hypothesis: cell damage, a costly immune response, competition between the host and parasite for resources, and parasite-induced behavioral changes that increase mortality. Cohuet et al., however, reasoned that a reduction in fecundity is a more commonly observed fitness cost of infections as it minimally affects transmission rates in comparison to a reduction in longevity. The article also delves into the length of the sporogonic cycle as a determinant of vectorial capacity; specifically, Cohuet et al. suggest that a longer time for sporogonic development favors producing higher number of sporozoites. The group further suggests that carrying out the sporogonic cycle at an optimal temperature yields a high number of sporozoites while decreasing the length of the sporogonic cycle. Intriguingly, a study revealed that Plasmodium­-infected flies demonstrated a greater attraction to higher temperatures than non-infected flies. Additionally, Cohuet et al. present a hypothesis suggesting that anthropophilic behavior plays a role in vectorial capacity. I find this hypothesis particularly appealing as it provides an evolutionary and historical context for the adaptation of high vectorial capacity in the Anopheles species. While the article delves into many studies and biological processes, I feel that Cohuet et al. do an excellent job of emphasizing the underlying evolutionary theme throughout the article. The notion that there is a constantly evolutionary ‘race’ between parasites and their hosts is rather intriguing; in particular, the fact that this adaptations ‘race’ often leads to rapid evolution is particularly interesting as the theory of evolution generally evokes the connotation of a slow process that occurs over thousands and thousands of years.

The main question of this article is: “What are the evolutionary features of human neurodegenerative disease genes with respect to non-disease genes?” Through analysis of gene expression level, number of regulatory miRNAs, protein connectivity, intrinsic disorder content, and relative aggregation propensity, Panda et al. observed that human neurodegenerative disease genes are evolutionary conserved relative to non-disease genes. Statistical analyses were performed using SPSS v.13. Mann-Whitney U test was used to compare the average values of different variables between two classes of genes. For correlation analysis, the Spearman’s Rank correlation co- efficient was performed. They also observed that human neurodegenerative disease genes have higher number of different regulatory miRNAs target sites and also have higher interaction partners than the non-disease genes. Overall, results showing higher gene expression level, higher protein connectivity along with greater miRNA regulation of neurodegenerative disease genes compared to non-disease genes support the conserved nature of neurodegenerative disease genes. In particular, highest (P=0.0001) expression of neurodegenerative disease genes were found near nervous system related tissues. In addition, it was found that non-disease genes on average show uniform gene expression level within the range of 25–60 whereas, for neurodegenerative disease genes the inhomogeneous expression level often fluctuates within the range of 25–150. Not only have the evolutionary features of human neurological disorders have been identified, but the complicated relationships between protein disorder content and RAP have been clarified. An implication of this study is that these results can be used in order to diagnose, prevent, and treat neurological disorders.

Link to article: http://web.a.ebscohost.com.proxy.library.emory.edu/ehost/pdfviewer/pdfviewer?vid=7&sid=ca4e29eb-500c-4354-94de-cc3144e48bd3%40sessionmgr4005&hid=4204

Fibroblasts are a cell type that are found throughout the human body; in your lungs, in your heart, below your skin. While there are a wide variety of fibroblasts, typically they are lumped together and regarded as a type of “biological glue” – there to hold everything together by providing components for the extracellular matrix, but not doing much else. However, a recent study at Monash University has proved that this is not entirely the case.

A Science Daily article describes the work of Dr. Milena Furtado, et. al. on cardiac fibroblasts. According to their study, cardiac fibroblasts are actually unique in their genetic makeup in a very significant way: they “remember” that they are specialized heart cells – the result of lingering transcription factors that are absent in other types of fibroblasts. These lingering transcription factors keep cardiogenic genes activated in these fibroblasts, which gives them the potential to contribute to heart development and repair.

This is very exciting, because it potentially offers a new way of treating heart disease. Evolutionarily, fibroblasts occur in a number of vertebrate species and perform very important roles in each of them. However, our understanding of how specialized the fibroblasts are or are not is fairly limited in a number of circumstances. The fact that we are just now discovering that cardiac fibroblasts have the ability to influence heart development and perhaps even more importantly the repair of heart tissue is a testament to this. But this study shows that there is potentially a lot can learn from systems like the fibroblasts, which could in turn have huge implications for the treatment of disease. In the case of heart disease, we currently have no knowledge of how to get the heart to repair itself. So if we could find a way to manipulate fibroblasts in order to get them to help with this process, it might reduce the need for heart transplants and provide a safer alternative to dealing with heart disease. Thus, while it not a guarantee of success, this study shows the importance of exploring new avenues and gaining new perspectives when studying disease.

A recent New York Times article describes a book that was released in Britain earlier this year and has started a new dieting craze in that part of the world. Titled “The Fast Diet”, this book describes a dieting plan that uses the idea of intermittent fasting: eating whatever you want (within reason) for 5 days of the week, then only eating two tiny meals a day during the other two. Co-author of the book Dr. Michael Mosley describes how, by following this regimen, he: lost 20 lbs., reduced his blood glucose and cholesterol levels, and reduced his body fat percentage. Many others have also claimed to have similar results, and this brings up the question of: why does this diet work so well?

Mosley mentions that the earliest ancestors of humans lived a feast-or-famine existence, gorging themselves when they had the chance and then going without until they were able to find another source of nourishment. The Fast Diet therefore is simply a return to our evolutionary roots, to the lifestyle that humans were adapted to prior to the introduction of agriculture. Additional support for this idea can be found in the fact that in times when the body does not have food to store, it turns its energies toward repair and recovery. If food came only periodically, then it makes sense that natural selection would favor individuals who put obtaining nutrients from food and storing them as a higher priority than performing comparatively insignificant repairs that could wait until later.

This idea of returning to our evolutionary roots is certainly an interesting idea, and Mosley and co. have demonstrated that their way has the potential to help improve human health in our modern society. However, there are also many other factors that play a role in how our diet affects our health. For instance, agriculture not only provided a more constant food supply but also changed the composition of what we eat. Our sugar and cholesterol rich diets have just as much, if not more, of a say in how much of how our diet affects us as the intervals in which we eat. So while The Fast Diet might be a step in the right direction, it should also be noted that there are many other factors that need to be accounted for in forming a healthy diet as well.

Considering it’s the last day of classes, I have been a little retrospective about our time this semester, and considering the importance of this course in general. I think it is great that this course is a part of Emory’s curriculum, and that many other universities are also adapting this kind of course in its biological education. What I found extremely exciting in terms of introducing Darwinian Medicine into undergraduate pre-medical education was how UCLA announced that since Fall 2013, they started Evolutionary Medicine as a minor for undergraduate students. This to me, is a great step forward for UCLA and a step towards the right direction for many other universities (such as ours) to follow in its footsteps.

Looking at the basic requirements, the minor would require 3 core classes:

1)      Evolution, Ecology and Biodiversity

2)      Intro to Ecology and Behavior

3)      Evolutionary Medicine

Apart from that, there would be 4 to 5 courses chosen from an incredibly diverse array of classes. These range from anthropology and physiological science to Community Health and Sociology. Other areas of elective courses include genetics, philosophy, sociology, and social welfare. The minor also has a research or internship requirement for an additional semester.

What, to me, sets this minor apart from the other minors that I have seen, is first a class directly geared towards medical practice and framework, and second the vast array of disciplines the minor covers. We as a class have discovered that evolutionary medicine includes a plethora of disciplines but to see that students will truly experience this interdisciplinary education is truly exciting. What other minor/major can allow you to choose from 17 different disciplines? Emory, take note!

References:

https://www.eeb.ucla.edu/images/EVMED_MINOR.pdf

UCLA introduces new evolutionary medicine minor. (n.d.). Daily Bruin. Retrieved April 24, 2014, from http://dailybruin.com/2013/09/30/ucla-introduces-new-evolutionary-medicine-minor/

During my Comparative Vertebrate Anatomy class we talked about the future of medicine and one of the things they talked about that I found really cool was 3D printing. 3D printers are becoming more and more common and are starting to be used to create artificial limbs and organs. One of the things they mentioned that I found amazing was 3D printing a skull for a woman who suffered from a thickening of the skull. The doctors printed out a 3D skull and surgically replaced her thickening skull. This happened in the Netherlands about 3 months ago and I was absolutely amazed. I heard 3D printing can be used to create artificial limbs and even organs, but replacing a skull was new to me. The operation was a success and the woman is doing fine.

Another new technology that can be used for medicine is google glass. Google glass has suffered controversy because of privacy concerns and there’s no doubt that there are still concerns like this when it it used for medicine. The application of google glass for medicine include pulling up medical records, augmented reality in surgical settings and automated personal heath care. For augmented reality in surgical settings, surgeons can pull up a virtual overlay of the patient’s body to look at critical structures during surgery, thereby possibly reducing the rate of surgical errors. It can also be used as a teaching tool to show medical students what surgery looks like from the surgeon’s point of view. It can also be used to call up other medical experts for help during a surgery. Like I stated though, this technology does have drawbacks like privacy concerns and distracting the surgeon since they are essentially using one eye to see records during surgery.

Sources:

http://medicalcenter.osu.edu/mediaroom/features/Pages/Google-Glass.aspx

http://www.fool.com/investing/general/2014/04/19/3-ways-google-glass-is-changing-the-future-of-medi.aspx

http://www.nbcnews.com/science/science-news/medical-first-3-d-printed-skull-successfully-implanted-woman-n65576

Biology is usually seen as a respected science. It uses labs and scientific methods to understand how diseases work and are passed on, but biology can’t always find the exact reason for all illnesses. For example, cancer is caused by unregulated cell growth due to some sort of mutation. This is can be seen through DNA testing. But what about mental illnesses? These illnesses cannot always be described strictly by biology. Yes, it could be some sort of mutation or brain imbalanced, but it doesn’t take into consideration cognitive thinking and behaviors. It’s like the nature vs. nurture debate. For mental illnesses, I believe a combination of biology and psychology is important, and yet psychology isn’t even recognized as a science in some schools. You can’t even get a BS in psychology at Emory. I think psychology can be recognized as a treatment for illnesses. People do go to psychiatrists and/or psychologists for help and it does seems to help some people.

Neha Kamat’s presentation on menopause was very interesting to me! It really got me thinking about what factors may affect the age of onset for puberty. Studies have shown that girls around the world seem to be entering puberty a lot sooner. In the 1990’s African American girls were developing breasts at age 9 and Caucasian girls were developing breast at around 9.5 years old. Today, girls are entering puberty about 4 months earlier than in 1997. So what could be the cause? There are many hypotheses in the science community about why this is happening.

A very popular hypothesis, that does not constitute a lot of solid evidence, is that there are an increased amount of hormones in the food we eat. Meat and dairy are thought to be the main food groups with a high rate of hormones.  The hormone BPA in plastic food packaging has also been labeled as a culprit.

The well rounded obesity hypothesis has the most supporting evidence. There is a link between percentage of body fat and the onset age of puberty. A higher rate of body fat is believed to produce more estrogen, causing a faster onset of puberty. There have also been studies that suggest there is a noticeable difference in the age of puberty and ethnicity. African Americans and Hispanic girls tend to start puberty before Caucasian females. Although,  change in the onset of puberty has been recorded in most ethnicity’s, including Caucasians.

One thing this class has taught me is that changes in genotype/phenotype are usually do to a combination of factors! Puberty is not an exception to the rule.  The main culprit is probably many changes in the local environment. These environmental factors range from economics to climate conditions. There is even evidence that the prenatal environment may have effects on the onset of puberty! It is hard to narrow down exactly what could be the main cause of this pattern.

Other researchers suggest that people are not properly diagnosing the onset of puberty, “The appearance of acne and pubic hair is common even in infants and toddlers. It goes away. We need to be careful about how we identify the true onset of puberty”, warns Dr. Lawrence Silverman. Recently, boys have also been starting puberty earlier than usual. Not much research has been done because it is harder to pinpoint the onset of puberty in boys. Girls have clearly physical responses to puberty such as breast budding and menarche.

This is a topic that is worthwhile to research because studies show that girls who enter puberty earlier in life have higher rates of breast and uterine cancer. Data provided from this research may provide answers to a lot of questions around risk factors for cancer. Early development in girls has also been linked with poor self-esteem, eating disorders, and depression, as well as cigarette and alcohol use and earlier sexual activity.

The reason why girls of certain ethnicities are more susceptible to this change still remains a question today.

CITATIONS:

http://www.cnn.com/2013/11/01/health/early-puberty-girls/

http://www.cnn.com/2010/HEALTH/08/09/girls.starting.puberty.early/

http://news.discovery.com/human/videos/why-girls-are-entering-puberty-sooner-than-ever-video.htm

Dr. Minas presentation was really interesting to me. I just wanted to share my response to the assignment for that class period. I would love to hear feedback on whether or not you agree with me!

1.   I would like the students to read the nature draft paper (if anyone wants the     supplementary model stuff they can email me) and write down a few comments for why this paper should and should not be published in very high profile journal like Nature – as though they are reviewing the paper for publication. Note that this is instead of your normal synopsis – so bring a printed copy of this to turn in.

I really liked how under each results section the authors clearly identified why they were doing that test. Most papers simply state how the results support or refute the hypothesis. There is no mention as to why, initially, the experimenters decided to do that specific test in the first place. I prefer this layout because it made the results easier to follow. The figures were very helpful; specifically Figure 2. It really helped with visualization and it was not confusing. Many papers that we have read for this class had very complicated figures/tables that were hard to follow. The one thing that I think could be changed, in regards to the structure of the paper, is the order of the sections. I found it odd that the materials and methods sections came last. Personally, I prefer for the materials and methods section to come earlier in the paper. The take-away message of this paper is that flu vaccines do seem to cause higher rates of bacterial infections, but this negative effect does not outweigh the positive that vaccines do for the public.

2. Read the two news articles regarding the mBio paper and compare and contrast them.

The Greenmed info paper used the data from the paper to support anti-vaccine campaigns.  I do not feel this was the original intention of the paper. It was very biased. The authors used evidence from the paper to totally persuade people to not get vaccinated. The science now article stated the evidence from the paper, but it did not force an opinion on the public. It presents the evidence in a way that the public can use to come to an informed decision about vaccinations.  I also like how this article mentions Mina’s future research that could support or refute his original hypothesis. The first article did not credit the fact that this data is not collected in humans as of yet.

3.   I would also like them to consider the research as though they are the director of the CDC:

 I do think that this research is worth doing. The public should be fully informed of the risks so that they can come to their own educated decision.  I do think that the private sector of healthcare might get backlash. Many people may start to oppose vaccinations, but that is not up to other to decide. Everyone is entitled to their own opinion. Also, if Mina’s suggestions about higher rates of infections due to lower vaccination rates does hold true, the implications could be worse than expected if many people decide against vaccinations. It is the CDC’s duty to report this information to the public. Immunizations are the major weapon of public health so is only fair that all the information is available to the public.