Sunday, January 25, 2009

Weekly Science Updates - It's All in the Genes

I've been scanning the annals of other science blogs and came across some interesting stuff that I am now sharing with you. In this edition of Link Love is All About Genetics.





You know how public health providers are always saying that your risk of contracting HIV, the virus that causes AIDS increases if you have had another STD? Well, this post - STDs disrupt genetic bottleneck that usually constrains HIV infection - explains how. Basically, when your body is fighting off a STD, via an inflammatory response, the chemistry of your genital mucous lining changes - becomes thin - and the HIV virus can penetrate the normally protective barrier and infect your cells.

Now, some good news about STDs. A joint study by researchers at the Albert Einstein College of Medicine of Yeshiva University and Harvard Medical School seems to have made a breakthrough in Herpes Prevention. A topical vaginal microbicide has been found to successfully silence two genes of the Herpes Simplex Virus-2 (the one that causes genital herpes) in mice. The microbicide can also safely protect against genital herpes infection for as long as one week. Read more about the study in the blog post: Topical Microbicide Offers Long-Lasting Protection Against Genital Herpes.

Genetic Tricks of Parasites is a quick read all about the small genomes of parasites. But one parasite species has an usually large genome ~ 23,500 genes, many more than other parasite species. Read the article to learn more.

And my favorite -Rethinking the genetic theory of inheritance. Scientists at the Centre for Addiction and Mental Health in Canada have made some breakthroughs in the research of addiction and mental health as it relates to Epigenetics. Epigenetics is the study of inheritance of traits beyond DNA. DNA is important and its discovery has lead to some very important discoveries, but I've always thought we have been rather pre-occupied with every thing being genetic. I'm looking forward to what more we can learn about Epigenetic research.

Tuesday, January 20, 2009

Inauguration Day Commentary - What really makes Conservatives & Liberals Different?

Barack Obama has been sworn in as the 44th President of the United States of America.  As the primary general election campaigns waged, I realized the pre-occupation we have with this nation’s political topography.  This notion of red and blue states and counties and liberal, moderate, and conservative citizens is interesting to me.  Entire regions, communities and families are labeled as red or blue; and we can trace these party affiliations back for generations.  This idea of political views as a heritable trait has piqued the interest of many, particularly bloggers who comment about the intersection of science and society, like me and Bora Zivkovic.

In a past post of his he writes…“that political affiliations are indeed a trait passed along from parent to offspring, but it is not because of genes. It is inherited via a developmental process.  Conservatives raise their children in such a way that their emotional development results in them becoming conservatives when they grow up, thus perpetuating the trait across generations - that is the definition of inheritance. And it is not teaching conservatism directly - it is providing an environment in which a child will develop conservative traits.”  I think no one exemplifies this more than Political Blogger, Cobb.  He is a conservative, his family had conservative views and he has a host of conservative friends. But what if our political leanings were more than indicators of our upbringing and social environment?  Could there be a biological explanation? Perhaps, according to a recent research article in SciencePolitical Attitudes Vary with Physiological Traits.

Could your political philosophies be tied to your physiology?

The 2008 Republican National Convention (RNC) showed a tribute video of the 9/11 Tragedy.  A compelling narration along with images the World Trade Center in flames, Americans dying, buildings collapsing and gun-toting-happy-terrorist enemies celebrating the carnage were on the big screen.  It ends with a declaration of “We will never let it happen again”.  The video evoked emotional responses from both sides of the political aisle; however, responses seemed to correspond according to the political leanings of the commenter.   For many conservatives, the video reminded them as to why a leader strong on national security was necessary for the safety of our nation.  Yet, many liberal correspondents – notably Keith Olbermann of MSNBC - found the video disturbing and accused the conservative political party of fear-mongering in order to promote their agenda.  

Was the RNC trying to connect to people through shock and fear?  Are political attitudes and reactions to devastating events tied?  Like political beliefs, behavioral and physiological reactions to unexpected events vary by individual.  Our body’s emergency response system, called the sympathetic nervous system, kicks in high gear when are frightened, startled or perceive a threat.  We reflexively react by blinking our eye lids or ducking for cover. Our heart rate increases, skin becomes clammy and we release nervous hormones like epinephrine and acetylcholine.   However, some people respond more strongly to startling events than others.  Would a variation in fear response correlate to a variation in political attitudes about national safety?  Researchers from the University of Nebraska-Lincoln set out to find the answer.  

Residents of Lincoln, Nebraska, were randomly selected from the telephone directory and interviewed to determine if they held strong political attitudes.  Subjects with strong political views, very conservative or very liberal, were then asked to participate in a second evaluation.   During this evaluation, subjects’ specific political attitudes were categorized according to their degree of support for protective policies.   Protective policies were defined as a generic suite of political concepts that dealt with enforcing strong security measures in order to protect the members of this society from tragedies.  Eighteen of the 28 political concepts on the survey were those that dealt with security issues such support for increased military spending, the Iraq War, the Patriot Act, as well as opposition to foreign aid, immigration, and gun control.   Individuals who indicated concern for protection and security in the 18 key political concepts were categorized as high supporters of protective policies.  The opposite was true of the subjects categorized as low supporters of protective policies.

Two months later, subjects completed two physiological response tests that measured their reflexive reactions to startling images and sounds.  In the first test, subjects were presented a slide show of 36 images, including three disturbing images of 1) a spider on a frightened person’s face, 2) a dazed individual with a bloody face, and 3) an open wound with maggots.  Researchers measured the average level of skin conductance or degree of subtle sweating and activation of the sympathetic nervous system in response to viewing all of the images.  In a second test, subjects’ eye blink response was measured when a loud, unexpected noise was heard.

The team found very clear differences in physiological responses to threatening stimuli between the two groups of subjects.  High supporters of protective policies demonstrated a marked increase skin conductance when they viewed disturbing images but no increased response when they viewed non-disturbing images.   Among low supporters, there was no difference in skin conductance response to viewing disturbing or non-disturbing images.  In fact, these subjects were mostly unaffected by either sets of images.  A similar pattern of response was measured in the startle sound-eye blink test.  Blink responses habituate over time for all subjects, however high supporters tended to blink harder than low supporters, though the differences were not as pronounced as those from the skin conductance test.  

Overall, the study demonstrated a relationship between physiological responses to threatening stimuli and political attitudes of subjects.  However, the biological basis of this relationship is not at all clear.  The research team suggests that the link between a person’s sensitivity to emergency situations and prevailing political attitudes may result in some people having a greater affinity to political policies that seem to offer the best solution to the perceived threat.  However, it does provide some credence to the RNC’s use of startling messages to rally the support of their political base in exercising stricter national security measures.