A DNA pollution solution?

big cow! When you think of greenhouse gas emissions, you probably think, “Ah, it’s all the cars people drive, that’s what contributes to the greenhouse effect!”  That’s what most people believe about greenhouse gases and air pollution, anyway.  But did you know that the major contributor to greenhouse gases comes from the gastrointestinal emissions of ruminant animals like cows and sheep?

That’s right, folks.  Cow and sheep burps and farts generate most of the methane that makes up the greenhouse gas in our atmosphere.  The construction of a ruminant animal’s digestive tract is slightly different than that of other herbivores in that there is a chamber known as a rumen where fermentation of food matter takes place.  Many bacteria, fungi, protists and viruses inhabit the rumen, and most of these play a role in helping the animal to digest plant fibers.  When these fibers are digested, a great deal of methane and carbon dioxide are produced, which make it into the atmosphere through eructation and release of flatus (the scientific ways to say ‘burp’ and ‘fart’).  The amounts of the various gases emitted depend on the diet eaten by the animal.  A diet rich in grain causes cows to produce less methane, while a diet rich in hay and other grasses produces large quantities of methane.

Stephen Moore of the University of Alberta has a two-pronged approach to solving this problem.  Moore and his colleagues have studied selective breeding in cattle as well as genetic modification of feed crops as a way to potentially reduce methane emissions by cows.  Moore posits that if the feed cows eat is modified so that it causes the cow to release less methane that perhaps overall greenhouse gases may be reduced in the atmosphere.  Moore and his colleagues have also identified several regions of the bovine genome that regulate immune system activity, which helps determine what microbes can inhabit the rumen.   This is important since you should note that it is the microbes that produce the methane, not the cow itself.  But the cow can regulate what microbes live within its rumen by modulation from the immune system.  Then, by selectively breeding cattle that naturally release less methane from the foodstuffs they eat, Moore believes that methane emissions can be drastically reduced.

This is an incredible discovery, but it is not without its problems, which lie chiefly with the cost to farmers and ultimately, consumers.  To produce both cattle and crops that are genetically engineered, a large amount of money must be invested in the biotechnology companies responsible for developing these organisms.  The costs of this investment are ultimately passed on to farmers, who must purchase these organisms.  Then the costs are passed along to the consumer when the organism or any product from the organism is produced, such as milk or meat from the cows.

Another issue that is a thorny one is the issue of whether people would consume products from genetically modified animals.  It has already been demonstrated that many people worldwide are resistant to the idea of eating cloned meat.  Even though the US Food and Drug Administration has declared cloned meat and milk safe to eat and drink, a majority of people are not convinced.  Might this prejudice against cloned organisms for consumption extend to genetically modified organisms as well?  Even if the organisms in question are being modified in an effort to mitigate a global problem–greenhouse gas emissions–should public opinion on GMO’s get in the way of solving this problem?

I’ll have a burger, some fries and a side of insulin resistance with my shake, please

fatkidseatingmickeyd's If you’ve ever seen the film “Super Size Me,” Morgan Spurlock, the documentary’s star and director, embarks on a month-long experiment to discover the adverse health effects of consuming a diet composed entirely of items from the menu at McDonald’s.  Spurlock decided to investigate whether or not eating only foods from McDonald’s would cause him any ill effects on his health because he had seen a news story about two teens who had sued McDonald’s because they claimed that McDonald’s food made them obese.  The suit was later thrown out of court by a judge who ruled that it was “not the place of the law to protect [the plaintiffs] from their own excesses.”

Spurlock begins the experiment in excellent health–his cholesterol, triglycerides and blood glucose levels are all normal.  Spurlock imposed several guidelines for conducting his experiment, which were:

  • He had to eat three full McDonald’s meals each day during the 30 days.
  • He had to sample everything on the menu at McDonald’s.  No other foods or drink were allowed.
  • He had to “Super Size” his meal if the option was offered to him.
  • He could only walk 5,000 steps daily.  This is the number of steps the average American walks in a day.  Spurlock’s normal step count before the experiment was in upward of 15,000 steps a day, as he lived in Manhattan at the time of filming and walked everywhere he went.  For reference, 5,000 steps is equal to roughly 2 miles.

supersizemeOver the course of his 3 McMeals a day diet, however, Spurlock gained 25 pounds, developed depression and fatty liver damage equivalent to that of an alcoholic.  It took him over a year to lose the weight he had gained during the course of the one month experiment.  After the film “Super Size Me” was released, several other people conducted similar experiments–both controlled and uncontrolled–but with very different results.   

Now a study conducted by biologists at Linkoping University in Sweden has revealed that eating fast food even twice a day contributes to an elevated level of insulin resistance, a precursor and indicator of type II diabetes.  Subjects in the study were in good health and had BMI’s in the healthy range for their age and height.  Once the experiment began, they were asked to consume two meals at a fast-food restaurant, as well as restrict their exercise to only 5,000 steps of walking a day.  At the end of their fast food bender, a sample of the subjects’  fat cells was taken and studied to determine if insulin resistance had developed, which it had. 

This is significant for several reasons.  First, billions of dollars are spent marketing fast foods to children, whose parents often opt to feed them fast food because of the cost and convenience.  Unfortunately, though, our physiology has not kept up with our fast-paced lives–here, evolution is working against us, not with or for us.  Second, because we are in a global recession, and healthy food costs more, people are more likely to turn to fast food for a plentiful and cheap source of food.   Third, as the rate of childhood obesity and its consequent poor effects on health skyrocket, the public should be aware of studies such as the Linkoping study and others like it.  There are a great many things that are affected by the fast food industry, the health of the public and the economy being the two biggest.

How can the results of such studies be communicated to the public in a way they will understand?  What ill health effects across socioeconomic lines will fast food diets have on the population?  How will this affect the nation’s healthcare system now and in the future?  Can people ever be completely weaned off of fast food, and would this be a smart move economically? 

Selling out your DNA

genepatentDid you know that it is legal to patent a gene?

According to US law, it is.  In 1980, the Supreme Court heard the case of Diamond v. Chakrabarty, which became a landmark for genetic science in terms of being able to lay claim to certain parts of the genome.  While working for GE,  Chakrabarty had developed a strain of bacteria that could enzymatically digest crude oil, which the court found did not occur naturally and thus could be patented since the bacteria were created artificially via genetic engineering.  This was a victory for genetic engineering and biotechnology, but the decision was not without controversy and has generated a multitude of bioethical and moral questions that have yet to be answered.

What does it mean to hold a patent, though?  Well, in layman’s terms, if you hold a patent for something, then that means that you have exclusive rights to make or sell that item or process.  It also means that if someone else wants to use your item in any item that they produce or process that they develop, they have to ask for your permission first.  You would likely charge that person a sum of money to use your item, which would generate an income stream for you and would allow that person to have a license to use your item/process–a win-win situation for both parties. 

Indeed, segments of the very molecule that every single living thing on our Earth possesses is available to patent.  But should it be legal to patent that which is present in all life?  Of what benefit is it to patent genetic material?  These questions are currently being debated in court, as a lawsuit has been filed by the ACLU against a company called Myriad Genetics.  Myriad Genetics holds patents on two genes known to be involved in breast cancer, as well as the tests used to detect these genes.  Currently there is only one test available for detecting the presence of the genes BRCA1 and BRCA2, and Myriad is the manufacturer of the test.  So if a recently diagnosed patient, such as Genae Girard of Austin, Texas, want a second opinion, there’s not one to be had.  Girard, with the ACLU, decided to file suit against Myriad, claiming that because Myriad holds the patent on the genes, no other tests can be developed for those genes without Myriad’s permission. 

There are benefits to gene patenting, but there are also drawbacks.  One benefit is that future research can be funded through licensing rights that the patent holder issues to others.  This could be especially important to private companies who may not receive government funding through grants, or it could be important to public institutions whose government funding has been drastically decreased due to budget cuts. 

A major drawback of patenting a gene sequence is that gene sequences can vary widely, even within the same species.  Remember in the video “Journey of Man” when Spencer Wells was sampling DNA from the Indian men at Madurai?  He later did an analysis on the DNA and found a singular difference in the sequence of one of the men that was significant.  These small, individual differences in DNA sequence are called SNP’s and they exist in all genomes, not just the human genome.  What happens when a sequence is patented, but someone finds a SNP in the sequence of an individual and wants to utilize that sequence?  Is this a violation of patent law, or the opportunity to file a new patent?

This apparent monopoly on the gene rights creates a myriad (ha!) of bioethical conundrums for biotechnology companies, patients and their health care providers.  When does free enterprise stop and the free exchange of information start?  Is it ethical for only one company to hold the knowledge about something as universal as a genome, or the information about that genome?  How can companies protect their intellectual property rights in a situation such as this?  How might gene patenting hinder health care for genetically-based illnesses?

 

A Rock and a Hard Place

If you have ever visited a place like Carlsbad Caverns in New Mexico, or the Inner Space Caverns here in Texas, then you know that these are underground caves that are popular tourist attractions, drawing thousands of people to visit them annually.  In France, the Lascaux Caves are also a popular destination for people who want to have a peek at man’s earliest artistic representation of his environment and events in his life.

cavepaintingsNot sure what the Lascaux Caves are?  Have a look at the paintings on the left there.  These paintings are estimated to be 16-20,000 years old, and are very elaborate paintings of hunts that people living during that time conducted.  These paintings are thought to be an excellent insight into human life at that time, since there is no other written evidence available that gives us a glimpse into life during prehistoric times.  They were first discovered in 1940 by a group of teens who were exploring in the woods and came upon the caves by accident.  The caves were open to the public after World War II, and many people from all over the world visited the caves to marvel at the paintings and the stories they told.

Unfortunately for the paintings, the carbon dioxide given off by the millions who had visited them took its toll, and in 1963, the cave was closed to the public to aid in the preservation of the art within.  A replica of the cave and its paintings was opened 20 years later so that people could still enjoy the artwork without endangering the original work.  In 2001, a fungus was found to be infesting the cave, aided by a new ventilation system as well as the people who had previously visited the cave.  To control the spread of the fungus, biocides were applied in an attempt to retard fungal growth.  While the biocidal chemicals applied controlled fungal growth in parts of the cave most often visited by people, the pigments left behind by the fungi still remain, permanently staining the walls of the cave.  Another problem that has arisen is the development of biocide-resistant microbes, including bacteria that normally cause disease in humans.  If these bacteria are being exposed to biocides and are becoming resistant, this could signal a problem for future visitors of the cave.

All caves have unique ecosystems that must remain in balance, and when humans decide to explore in them or otherwise enter, the very action of their entrance alters the balance of the ecosystem within the cave.  In a place like Lascaux that holds so much historical and cultural significance, the alteration of the ecosystem that occurs with each visit must be accounted for.  Should places such as Lascaux be open to the public?  Which is more important:  preservation of history and culture, or preservation of ecosystem and environment?  Can science help us to have both?

Mostly cloudy with a chance of cytokine storms

flumaskUnless you are living in a cave, you are well familiar with the swine flu (aka H1N1 virus) pandemic currently happening all over the world.  The current count of confirmed cases worldwide stands at 331, but certainly by day’s end, the count will rise.  The death toll due to H1N1 virus currently stands at 13, with 12 of those deaths occurring in Mexico, and one here in the US.

Many people have wondered, “Why are young people dying at a more elevated rate than those who are elderly?”  It has to do with the immune response to the virus itself.  Unlike other flu viruses, which enter the cells of the respiratory tract, transmit their genetic material, make the victim generally miserable for a week or so, and then succumb to the body’s immune response, victims of H1N1 flu are actually falling prey to their own immune systems.  It’s a sad irony that the very system designed to protect you from pathogens like viruses and bacteria in this instance is what brings about your demise.

flucytokinestormBut how does this happen?  One of the components of an immune response is the inflammatory response.  This is generally mediated by macrophages and T cells, which become activated once exposed to a pathogen.  Activation of each of these cells involves their binding to the pathogen (H1N1, in this case), and the result is the production of cytokines.  Cytokines are a class of chemicals used in cell signaling, but are not limited to the action of the immune system.  The cytokines released during an infection with H1N1, however, trigger a phenomenon known as a cytokine storm.  The cytokines released mobilize other T cells and macrophages, which mobilize even more T cells and macrophages.  This “storm” sets off a cascade of events that eventually ends in death for some flu victims, and the underlying cause is essentially an overzealous immune response, similar to an anaphylactic response when someone is exposed to allergens.

Once the cytokines have been produced, their release stimulates an inflammatory response that results in the death of lung tissue, swelling in the lungs, fluid buildup and subsequently, death.  It is thought that cytokine storms are the reason why so many people died during the flu pandemic of 1918 (the death toll was thought to be as high as 100 million globally), as well as the SARS outbreak of 2003.

Deaths due to these cytokine storms are why health experts are suggesting that schools be closed, events be cancelled and travel be restricted.  This particular strain of H1N1 seems to be spread rather easily, and by limiting contact with others who may be potentially infected, the transmission of the disease can be slowed down.  A vaccine does not yet exist, and will take months to generate; however, health officials are optimistic that one can be created in time for fall/winter flu season.  Yet cities are cancelling festivals, concerts and events where large groups of people are expected to congregate.  Likewise, school systems are closing schools as well as shutting down entirely, all in a bid to stave off further spread of the virus.  But is it excessive to close an entire district down for one case of swine flu?

What do you think about the media’s role in spreading the news about the flu?  Is the press coverage adequate to protect the public, or is it causing more harm than good?  How much press coverage is too much, and what duty does the media have in informing the public about public health emergencies?