The Concept of Sustainability in Agriculture

An article in the New York Times free online edition this week discusses two possible examples of what might turn out to be unsustainable modern agricultural practices (“Our Decrepit Food Factories”, by Michael Pollan. nytimes.com, Dec. 16). Mr. Pollan suggests that MRSA (methicillin-resistant Staphylococcus aureas) infections in humans may become more common due to the widespread use of antibiotics in pig feed. He also presents some good arguments for why the worldwide collapse of honeybee populations may be due in part to unsustainable modern farming practices that stress the bees.

It makes for easy reading at the student level. The article could be used to spark a discussion about how best to actually achieve agricultural sustainability in the face of pressures to produce more food for a growing world population.

Cancer Therapy

The January issue of Scientific American, now available in electronic form, will have an interesting article about how antiangiogenic drugs (drugs that inhibit blood vessel growth) such as Avastin actually work in cancer therapy. It turns out that it’s not just that they reduce the overall blood supply to a tumor, although that is one of their actions. In fact, they also normalize the remaining vessels, pruning them and improving their permeability properties. As a result, antiangiogenic drugs improve the effectiveness of other cancer treatments such as chemotherapy, because now the chemotherapeutic drugs are better able to reach the tumor cells.

But there is only a window of opportunity in which the combination of antioangiogenic drugs and other therapies is particularly effective, because the antiangiogenic drugs are hard on blood vessels throughout the body and because tumors may eventually lose their responsiveness to the drugs. Nevertheless, our improved understanding of how antiangiogenic drugs actually work is opening new avenues for developing more specific cancer treatment regimens. To learn more, read the original article (“Taming Vessels to Treat Cancer”, by Rakesh K. Jain. Scientific American Jan. 2008, pp. 56-63).

Stem Cell Breakthrough

In late November Dr. Shimya Yamanaka reported in Cell that he had produced human stem cells from adult human cells taken from the cheek of a middle-aged woman. On the same day, Dr. James Thomson reported in the online version of Science that he had achieved similar success with foreskin cells from newborns.

Scientists are hailing these two reports as a technical breakthrough in stem cell research. The key is that these two researchers derived their stem cells from older cells, NOT from embryonic cells. Stem cell research has always been highly controversial because most of the stem cells used in research come from human embryos (see the Current Issue in Human Biology 5th ed., pp. 72-73). But if human stem cells can be created from older cells without sacrificing human embryos, then the whole “sanctity-of-life” issue is off the table. An added benefit is that if a simple cheek cell can be used, then stem cells could be grown specifically for any patient, using cells taken from that patient.

It’s way too early to think of growing a new heart for a patient in heart failure from his/her own cells, though. Although these new findings show that we have reached a basic level of understanding of how to create stem cells, we don’t yet understand how to direct them into becoming the specific human organs or tissues we might need to treat disease. Many scientists, including Dr. Yamanaka and his colleagues, argue that it would be “a serious mistake” to move too quickly to end all embryonic stem cell research, based on these very first successes at creating stem cells from adult cells. They believe that embryonic stem cells are still likely to be necessary for decades to come.

Still, it’s encouraging to think that in our lifetimes, the controversy over stem cell research may just slowly disappear.

Barry Bonds Indicted

Home run king Barry Bonds was indicted this week on felony charges that could send him to prison for at least a decade. Bonds is charged with lying under oath to a federal grand jury back in 2003. Bonds has always claimed that he never knowingly used performance-enhancing steroids, but government investigators now say they can prove that Mr. Bonds used steroids, based on a positive blood test seized during an investigation of a California laboratory that sells them. Bond’s lawyer calls the charges “ridiculous”. The case may drag on in the courts for years. In the meantime, many baseball fans will consider Bonds’ home run record to have an asterisk after it.

The dangers of steroid abuse by athletes are discussed in Human Biology 5th ed., pp. 134-135.

Birth Control Pills on Campus, Revisited

Previously I reported that sweeping changes in Medicaid reimbursement rules were likely to have the unintended consequence of causing a sharp increase in the cost of birth control pills on college campuses this past Fall (see this blog, July 24, 2007 posting). Indeed, the cost of birth control pills on many campuses did go up, on some campuses by as much as 10-fold. Some college health clinics stopped providing birth control pills entirely.

Fortunately, relief is in sight. Introduced by Representative Joseph Crowley of New York and backed by over 100 co-sponsors on both sides of the aisle, the Prevention Through Affordable Access Act (HR 4054) would restore the ability of college health clinics and safety-net health care providers to buy birth control pills at discounted rates and to pass those savings on to college women and other women in need.

Apparently the word “prevention” in the Prevention Through Affordable Access Act stands for prevention of unintended pregnancy. According to a press release from his office, Representative Crowley states that “A bureaucratic mistake should not stand in the way of protecting the health and safety of hard-working women. My colleagues, who are interested in effectively preventing unintended pregnancies, ought to support this measure and join us in urging its immediate passage.” Well said, Congressman Crowley.

Do your students understand the legislative process? Are they interested in how specific legislation (this one is a good example) might affect them personally? How do they feel about this particular bill?

Merck Settles Vioxx Lawsuits

The news media are reporting this morning that Merck has agreed to settle 27,000 lawsuits against the company for damages related to its painkiller, Vioxx, for $4.85 billion dollars. (See the New York Times online at nytimes.com, Nov. 9 - "Merck Agrees to Settle Vioxx Suits for $4.85 Billion"). Since the lawsuits cover about 47,000 plaintiffs, the average plaintiff will get around $100,000 before paying his/her lawyers 30-50%.

The issue of what Merck knew and when they knew it regarding the potential health damage that could be caused by Vioxx is highlighted in Human Biology 5th ed., pp. 182-183. Merck had vowed to fight each and every lawsuit over Vioxx in court, a strategy that seemed to work for the company. Because Merck won most of the first 20 cases, plaintiffs began to realize that their best hope was for a modest but guaranteed settlement, rather than the chance of nothing at all if they sued individually for huge amounts.

For Merck, $4.85 billion was less than Wall Street had anticipated, and less than one year’s profit.

Biofuel for Home Heating

Massachusetts may become the first state in the nation to require that home heating oil and diesel fuel contain at least 5% biofuel, if the governor has his way. He and other legislative leaders introduced a bill in the Massachusetts state legislature this week that would require the addition of biofuel to home heating oil and diesel fuel by 2013.

Biofuels could become an important potential source of renewable energy for our long-term future, right up there with solar and wind energy. Although the technologies for making it are still new and in the development stage, a variety of biofuels can be made from wood chips, grasses, waste cooking oil, and other renewable plant material. The bill in Massachusetts is an attempt to support the fledgling biofuels industry, while at the same time creating jobs in the state and (ultimately) driving down the costs of energy. Already, several companies are making plans to build biofuel plants in Massachusetts, according to an article online in the New York Times (www.nytimes.com: “Massachusettts Looks at Using Biofuel in Home Heating Oil”, Nov. 6, 2007).

You could engage your students in a debate (or assign a writing task) centered on what they think will be the primary sources of energy in their lifetimes, 50 years from now. You could also ask them to look into what your state is doing, if anything, to encourage the use of renewable fuels.

Fair-Haired Neanderthals

Those who are particularly interested in genetics and human evolution might want to take a look at the article published online in Science last week (E-pub ahead of print: 10.1126/science.1147417) and the published news item related to it (Science 318:546-547, Oct. 26, 2007). The authors of the online research article report that Neanderthals have a particular gene mutation that suggests that at least some Neanderthals had pale skin and red hair. There’s still no indication that Neanderthals ever interbred with modern humans, though. Instead, it appears that the Neanderthals evolved independently toward more human features before they died out entirely.

The Buzz on Bone and Fat

In Human Physiology 5th ed. (p. 104-105) I point out that bone growth, remodeling and repair are enhanced by weight-bearing exercise and can be stimulated by weak electrical currents. But I learned something new today - apparently it’s also known that that in several animal species including mice and sheep, just standing on a platform that vibrates at a low frequency (like a buzz) leads to bone growth. That’s interesting enough, but now scientist have demonstrated that when mice are placed on a vibrating platform for just 15 minutes a day they not only gain bone mass, they also have 27% less body fat. The work will be published in the Proceedings of the National Academy of Sciences Nov. 6, but it is already available online.

Huh? It sounds incredible - so incredible that it amazes even the scientists who did it. They caution that they don’t yet understand WHY the mice gain bone mass and have less body fat, but they have some hypotheses. One is that the low frequency vibrations may stimulate stem cells in bone to become bone cells instead of fat cells. Other scientists remain skeptical of this hypothesis, saying that perhaps the mice have less fat because they eat less or because they are doing more muscle work to maintain their posture on the platform. Certainly these are all good hypotheses that deserve to be tested.

According to a New York Times article published online on Oct. 30 (“Low Buzz May Give Mice Better Bones and Less Fat”, by Gina Kolata), a clinical trial is underway in elderly people to determine whether a buzzing platform will affect adult human bone density (and body fat) like it does in mice. Perhaps in a few years we’ll know, and a new therapy for osteoporosis will emerge.

Don't Overlook the GOOD Bacteria...

We wouldn’t want students to think that ALL bacteria are bad – in truth, most of the thousands of different species of bacteria in our bodies are harmless or even beneficial. Bacteria living within our bodies contribute to such important functions as maturation of the human immune system, the synthesis of vitamins and the digestion of foodstuffs. It may not be a good idea to try to wipe them all out, as an article in Newsweek this week points out. (“Caution: Killing Germs May be Hazardous to Your Health”, Newsweek Oct. 29, 2007, pp. 44-48). It’s an easy read, well worth your students' time, and it might serve as a counter-balance to the constant barrage of news about truly bad bacteria such as MRSA (see post on Oct. 26).

The Rise of a Drug-Resistant "Superbug"

A drug-resistant strain of “superbug” called MRSA (methicillin-resistant Staphylococcus aureus) has been in the news recently. MRSA is transmitted by skin-to-skin contact or by sharing infected items such as towels or sports equipment. It generally enters the skin through cuts and abrasions, causing boils and painful abscesses in the skin. However, if it enters the bloodstream it can attack internal organs and kill the patient.

MRSA was a rare hospital-based infection until the 1990s. Then it began to show up in prisons, locker rooms and gyms, and poor urban communities. It is now the most common cause of soft tissue and skin infections seen in hospital emergency rooms (“Methicillin-resistant S. aureus infections among patients in the emergency department”, N. Engl. J. Med. 355:666-674, 2006). It is often misdiagnosed and is very difficult to treat; more than half of all patients who come to emergency rooms with MRSA infections are treated with antibiotics that don’t kill it.

Last week, scientists at the Centers for Disease Control and Prevention reported that MRSA may be even more prevalent and more dangerous than previously thought. They estimate that MRSA may contribute to more deaths per year in this country than AIDS (“Invasive Methicillin-Resistant Staphylococcus aureus Infections in the United States”, JAMA 298:1763-1771, Oct. 17, 2007).

Also last week, the news media reported the death of Ashton Bonds, a 17-year-old high-school senior, due to a MRSA infection that had spread to his liver, kidneys, and lungs. As a result of his death, all 21 public schools in Bedford County, Virginia were shut down briefly for cleaning and disinfection.

Epidemiologists worry that the rise of MRSA is the natural outcome of the over-use of antibiotics, which only encourages bacteria to evolve toward antibiotic resistance (for more on the subject of antibiotic resistance, see p. 18 of Human Biology, 5th ed.) This bug will be hard to kill. Keep an eye on it.

Global Warming and Loss of Species

Many scientists believe that the Earth is losing animal and plant species at a more rapid rate than in past millennia, in part because of the effects of humans on complex ecosystems. For example, human activities such as building cities and highways, clearing and tilling land for food crops, and diverting water resources for our own use all affect the habitats of specific species. But now scientists report that humans may also increase the rate of species extinctions through our effect on carbon dioxide emissions and global warming.

In an article published online in Proceedings of the Royal Society. B, Biological Sciences (doi:10.1098/rspb.2007.1302), British ecologists report that four out of five periods of mass extinctions of species over the last 520 million years coincided with periods of warmer world climate. And according to climate scientists, Earth is now on track to reach similarly warm temperatures within 100 years unless global emissions of carbon dioxide are reduced soon. Fully 20-30% of all species assessed so far “are likely to be at risk of extinction” if temperatures rise just 3-4 degrees Fahrenheit, according to the highly respected and authoritative Intergovernmental Panel on Climate Change (IPCC).

A big issue of the century will be what, if anything, to do about it.

A Function for the Appendix?

It has long been thought that the small blind-ended pouch near the end of the small intestine called the appendix is vestigial, i.e. it no longer serves any useful function in humans. But now scientists at Duke University hypothesize that the appendix may indeed still have a function. In a September 7 article online in the Journal of Theoretical Biology, the researchers speculate that the appendix serves as a reservoir (or safe haven) for “good” bacteria in the event that a severe bout of diarrhea flushes out most of the bacteria in the small and large intestines. After the diarrhea has passed, according to the scientists, the bacteria in the appendix could emerge to repopulate the intestines.

It’s an interesting thought, but this is speculation, not yet proved. The Journal of Theoretical Biology is a vehicle for ideas, not hard scientific data. My question would be if the appendix does serve a useful function, why don’t most animals have one? (Apparently only humans, rabbits, and two species of marsupials have an appendix.) An admittedly equally speculative explanation might be that while the appendix does harbor bacteria that help repopulate the gut after a bout of diarrhea in humans, that function is not so significant that it confers significant survival value any more. In other words, the appendix ultimately still may be considered vestigial.

The concept of survival value of a given structure or function is an important one for students to understand when discussing evolution, of course.

Breast Cancer Around the World

The cover story in this week’s issue of Time magazine (Oct. 15) is about the worldwide incidence of breast cancer. The article discusses how the economic situation in different countries affects the likelihood of screening for breast cancer and the probability that the cancer will be adequately treated once it is detected. The reasons for a failure to detect and treat breast cancers are different in different countries, but they include a shortage of doctors, diagnostic equipment, and x-ray film; the high cost of treatment relative to income; and the inability to reach a medical facility because of the lack of transportation.

Aside from the usual genetic influences, students might be interested to learn that cultural differences also influence the diagnosis and treatment of breast cancer. The article points out that in some countries, women are afraid to admit to having breast cancer out of fear that their husbands will leave them or that their daughters will be shunned by prospective marriage partners. Diet, too, has a significant effect, for reasons pointed out in the article. And finally, there is just plain ignorance about the disease – in one instance, a woman who had an obviously-visible tumor admitted that she had not been diagnosed earlier because it didn’t hurt. Clearly, the fight against breast cancer will need to be fought differently from country to country.

DNA Evidence Exonerates the Innocent

More than 300 persons convicted of rape or murder between 1989 and 2003 were later exonerated by new DNA or other evidence that proved their innocence, according to a study by a University of Michigan Law School professor (Samuel R. Gross, et. al. Exonerations in the United States 1989-2003. Journal of Criminal Law & Criminology 95:523-560, 2005.) In most cases their wrongful convictions were at least partially due to false identification by eyewitnesses. How many persons were erroneously convicted or even put to death in the past? We may never know.

The certain knowledge (with the help of DNA evidence) that mistakes were made in the past is fueling widespread reform of our criminal justice system, and thousands of innocent convicts may have their second day in court as a result. Its also prompting legal changes, including requirements in many states that confessions be recorded (to reduce the number of false confessions), and that informants’ testimony be corroborated before it can be used in a courtroom. States are also tightening up their procedures for how witnesses identify suspects in lineups and in photos.

On page 468 of Human Biology 5th ed. I describe the scientific basis for how a DNA sample is used to identify a particular individual. It's nice to see that its being used to protect the innocent, as well as convict the guilty.

Body Size and Athletic Ability

According to an article in the on-line version of The New York Times today (“Bigger is Better, Except When It’s Not”), world-class rowers usually are big. Swimmers are tall. Distance runners are small and light. It’s all according to the rules of physics, exercise researchers say.

Previously I speculated that in a high-tech future world, children and their parents will be able to choose what sports the child is most likely to excel in based on hard scientific evidence (see the Directions in Science feature in Human Biology 5th ed., p. 132). Apparently some of the evidence is now known. But this does not mean that size, body form, and muscle biochemistry are all that matter. As the experience of Lance Armstrong has shown, good training and desire also count for something, too. Unless you aspire to be the best in the world, go out and do what you enjoy!

AIDS Vaccine Fails in Clinical Trials

This week Merck announced that it was halting test vaccinations of human volunteers with its promising new AIDS vaccine when preliminary findings showed that the drug was not going to be effective in preventing HIV infection. The vaccine was already in Phase II testing (Phase I – is it safe? Phase II – does it work?), meaning that Merck had already invested a lot of time and money in it. Details of the vaccine and its failure can be found on Merck’s website (http://www.merck.com/) under “Research and Development News”.

In Human Biology, 5th ed. (p. 215) we mention that a vaccine may be the only real hope of conquering AIDS once and for all. The failure of Merck's vaccine is a setback for AIDS research and for Merck, to be sure. But Merck’s vaccine was not the only AIDS vaccine under development; currently there are about 30 AIDS vaccines already in either Phase I or Phase II trials in humans.

And kudos to Merck for knowing when to give up this time! Perhaps they learned a lesson from their fiasco with Vioxx (see the Current Issue in Human Biology pp. 184-185). This is how good science is supposed to work - without bias based on financial interest.

Artic Ice Loss Accelerates

The artic ice cap may be melting much faster than previously thought, according to scientists from the National Oceanic and Atmospheric Administration (NOAA). The scientists tested 20 different climate change computer models for their ability to replicate the sea ice conditions that actually existed between 1979 and 1999. After discarding the models that couldn’t accurately replicate the actual data, they used the remaining models to predict the artic ice melt to 2050. They report that the arctic ice cap may shrink by more than 40% by 2050, even if atmospheric carbon dioxide levels remain where they are today. But it's more likely that carbon dioxide levels will continue to rise, given our appetite for fossil fuels. The original article is published in the September 8 issue of Geophysical Research Letters.

A major loss of arctic ice would be bad news not just for polar bears, but for marine ecosystems in general. The winners: oil and gas companies would be able to explore more of the arctic sea bed for new sources of oil and gas, and ships might be able to use northern shipping routes between the Atlantic and Pacific during the summer months.

Note added Sept. 28: The Oct. 1 issue of Time magazine has a cover story which discusses the political and economic implications of the loss of arctic ice due to global warming. Apparently, nations are rushing to lay claim to the land (and mineral resources) previously under the ice, and shipping companies are eagerly awaiting the time when the Northwest Passage is open, at least for some of the year.

New Twist on Steroid Use in Baseball

According to a report on CNN’s Sports Illustrated website (SI.com) this week, three major-league baseball players received shipments of banned performance-enhancing (anabolic) steroids over several years. The report cites records obtained from unnamed sources. Although Major League Baseball has asked to talk to the players, none of the three has yet tested positive for steroids.

Huh? Perhaps we’ll hear a variation of the old “I smoked but I didn’t inhale” defense - “I bought them, but I never used them…”.

Anti-doping experts believe that players may be escaping detection by using human growth hormone in conjunction with very small doses of performance-enhancing steroids such as testosterone. Although there is no reliable test for exogenous human growth hormone, its use is banned by Major League Baseball.

The use of anabolic steroids in sports is discussed in Human Biology, 5th ed., pp. 134-135.

Merck Avoids a Class-Action Lawsuit Over Vioxx

Yesterday the New Jersey Supreme Court rejected a class-action lawsuit brought against Merck by a union health plan. The International Union of Operating Engineers Local 68 in Caldwell, N.J. was seeking a class-action lawsuit representing all of the insurance companies nationwide that had ever paid for Vioxx prescriptions as part of their health care plans. The court ruled that a single nationwide class-action lawsuit was not appropriate under the circumstances. Each insurance company will now have to sue Merck on their own (or not).

The ruling is a victory for Merck. However, Merck still faces an estimated 27,000 lawsuits from individual patients who claim that Vioxx causes strokes and heart attacks, and that the company knew it long before the drug was pulled from the market. Merck has vowed to fight each and every lawsuit one at a time. So far the strategy is working – Merck has won nine and lost five. At this rate, most of the patients will be dead from other causes long before they ever see a dime from Merck.

By the way, remember Mr. Leonell Garza, the 71-year-old man described in the Current Issue feature in Human Biology, 5th ed. (pp. 182-183) whose family was suing Merck for $1 billion in damages? A Texas jury awarded the family $32 million, but that had to be reduced to $7.75 million by Texas law. Merck is appealing. Stay tuned!

Basic Principles of Good Dieting

Instructors who are looking for a readable recent article on diets and dieting for their students should take a look at the article entitled "Eating Made Simple" in the September issue of Scientific American (pp. 60-69). The article cuts through the confusing mountain of good and bad dietary advice out there by pointing out that the principles of good dieting are not in dispute – eat fewer calories, get more exercise, eat more fruits, vegetables and whole grains, and reduce our intake of junk foods.

When we get too deep into the details, however, (Is this food better than that food? And better for what?), we are likely to confront conflicting advice. That’s because nutrition research is difficult do and often produces ambiguous results. To complicate matters, a lot of nutrition advice comes from sources that are trying to sell us something. (See the comments by the Scientific American editors on pages 38-39, entitled “Take Nutrition Claims with a Grain of Salt”.)

If we really could get students to focus on the basic principles – reduce their overall caloric intake, get more exercise, and try to become a bit more knowledgeable about which are the “good” food categories - the details probably wouldn’t matter all that much.

Can a Physician Refuse to Treat a Patient?

Yesterday I wrote about two Washington pharmacists who are suing for the right to refuse to sell the morning-after pill because of their religious and moral beliefs. What rights do physicians have when it comes to offering certain services or choosing to treat certain patients?

According to the Guttmacher Institute, 46 states specifically allow doctors to refuse to provide abortion services if they wish. Sixteen states allow doctors to refuse to provide sterilization services, and at least 8 states allow doctors to refuse to provide contraception. These policies have stood up to challenge as long as the doctor does not offer the service to any of his/her patients.

Well, okay, doctors certainly should have rights, too. The problem arises when a doctor provides the service to some patients but then refuses it to others. Patients’ advocates say that such doctors are hiding behind religion while violating anti-discrimination laws. For example, if a physician prescribes Viagra for a straight guy, should he/she be allowed to refuse it to a gay patient? What about a doctor who refuses artificial insemination to lesbian couples and single women, but offers it to married couples?

The California Supreme Court is about to hear a case in which a lesbian woman is suing two doctors for refusing to provide artificial insemination to her on religious grounds. The case is generating a lot of interest, with over 40 groups asking to be heard. Doctors’ attorneys are likely to argue that if physicians are forced to violate their religious or moral beliefs they may be driven out of certain specialties. But is it right that they should be able to force their beliefs on others instead?

What do you think? Whose rights should take precedence here?

Pharmacists Sue over 'Morning-After' Pill

Last year the federal Food and Drug Administration made the ‘morning-after’ contraceptive pill known as Plan B available without a prescription. So can a pharmacist who sees the pill as tantamount to abortion and who objects on moral or religious grounds refuse to sell it? In Washington State, the answer is no. The State of Washington passed a regulation recently that requires pharmacies to sell the pill, arguing that individual pharmacists cannot stand in the way of patients’ rights to a perfectly legal drug. Last month two Washington pharmacists sued in federal court over the issue, arguing that the regulation forces them to choose between their jobs and their “deeply held religious and moral beliefs”. The case is pending.

In fact, a compromise of sorts had already been worked out between the governor and the state Board of Pharmacy even before the lawsuit. In the compromise, a pharmacist with personal objections to selling the drug is free to get a co-worker to fill an order. But that only works if a co-worker is available - the patient must not be inconvenienced by having to make a second visit. And not all pharmacies have at least two staff members on duty at all times.

Apparently this is becoming an issue in many states. Four states (Arkansas, Georgia, Mississippi and South Dakota) have specific policies that allow pharmacists to refuse to sell contraceptives if they wish. On the other hand, pharmacists in California can only refuse to sell contraceptives when their employer approves and when the woman can still get her prescription filled in a timely manner. That sounds a lot like the new Washington law. It’ll be interesting to see how the legal challenge in Washington comes out.

What do YOU think?

Obesity in Close Mutual Friends

If your closest friend becomes obese your risk of obesity goes up dramatically, according to researchers. And it was not just a matter of the friends eating the same foods, because the relationship holds even if the friends are separated geographically. Your risk also goes up if you have a sibling or a spouse who becomes obese, though the effect is not as great as between best friends.

How might social relationships affect obesity? Researchers speculate that when a person who becomes obese is already a close mutual friend, a sibling, or a spouse, one may tend to perceive obesity as more acceptable than if the person is a total stranger. Close mutual friends may also influence a person’s eating habits, even if the friends are not always together.

The data also offer a clue for why many of the most successful weight-loss programs are those that offer peer support. By modifying a person’s social network to include people who are also trying to lose weight, one’s view of normal and acceptable begins to change. The bottom line is that obesity is not just a medical problem with genetic roots, but also a public health problem with social causes. Understanding obesity will require a full understanding of both.

Birth Control Pills on Campus

The cost of prescription birth control pills is likely to increase dramatically on many college campuses this fall. Manufacturers of birth control pills routinely used to sell the pills to college health clinics at steeply discounted rates in an effort to win future customers. And in an effort to encourage responsible behavior and make birth control readily available, many colleges passed those savings directly on to the users. But according to an article in this week's The Chronicle of Higher Education (July 27, pp.A31-A32), changes in Medicaid reimbursement rules have made it too costly for the manufacturers to continue this practice. As a result, some college women will find that prices have gone up as much as 5-fold on campus this fall – to the same price they’d pay at a commercial pharmacy.

The American College Health Association is lobbying to have the Medicaid reimbursement ruling reversed, at least for college campuses, arguing that it was an unintended consequence of a change in the law. But that’s not likely to happen by the time students return to campus this fall.

Bird Flu Preparedness in the U.S.

This week the federal government released a report card on U.S. preparedness for a bird flu pandemic. The report comes just over a year after the government issued their National Strategy for Pandemic Influenza Implementation Plan. The new report stresses that although most of the original plan has already been put into place, areas of weakness include a limited capacity to detect an outbreak, and the possibility that hospitals would be overwhelmed by the large number of persons who might become infected.

The report also notes that media attention to bird flu seems to have died down. And yet, almost as many people have died of the disease in 2007 as in each of the previous two years. Do we just have short attention spans?

The complete report can be accessed at www.whitehouse.gov/homeland/pandemic-influenza-oneyear.html.

Would You Eat Your Placenta?

It’s called placentophagy (or placentophagia). There are no statistics on the percentage of new moms who do it, but there are a surprising number of references to it on the Web. There are even recipes for preparing placenta – placenta pills; placenta blended with V8 juice; placenta sauteed with olive oil and garlic; placentaburger; placenta lasagna; even placenta smoothies! Maybe I'm just not adventurous, but I think I'll pass on this one.

Proponents argue that most mammals eat their placenta (true, but what’s the relevance?) and that eating the placenta confers nutritional or health benefits to the new mom, including reduction of post-partum pain, depression and bleeding (largely untested). There are lots of anecdotal testimonials from new moms who say they feel just great after eating portions of their placenta. But hey, if you’re willing to chow down on your placenta in the first place based solely on your belief system, is it any surprise that you would report feeling better afterwards? There are even fathers trying it. Call me a skeptic, but what would it do for the father?

Eating raw human blood products could increase the risk of contracting hepatitis B, C, and HIV. And anyone thinking about frying up some placenta for its alleged health benefits should know that there are plenty of other ways (pharmaceutical drugs, hormones, and vitamin pills) to reduce post-partum pain, bleeding, and depression, or to maintain good post-partum nutrition.

Instructors could use this topic to explain the difference between belief and scientific evidence; between anecdote and statistically significant data. They could also have students research the topic, bring in statements about the health benefits of eating the placenta, and then discuss (or vote) on whether the statements are closer to “belief/anecdote” or to “science/data” so they can begin to see the differences. Who knows, they might even find that there is some good scientific evidence out there that I am not aware of.

Antidepressants and Childhood/Adolescent Suicide

One of the most basic rules of medicine is expressed in the Latin phrase primum no nocere – first do no harm. So here’s an real-life ethical dilemma for you; if antidepressants such as Prozac have the potential to cause harm to some patients, is it still okay for a physician to prescribe them if, in the balance, the drugs help more patients than they harm? That, apparently, is the dilemma now faced by the Food and Drug Administration (FDA).

Several years ago a careful analysis of trials of antidepressants reported that Prozac and the other drugs in its class (known as selective serotonin reuptake inhibitors, or SSRIs) increase the risk of spontaneously reported suicide-related events in children and adolescents. Accordingly, in 2003 the FDA issued a health-advisory that children and adolescents on Prozac might be at “increased risk of suicidal thinking and behavior”, and ordered that a black box warning be placed on all prescriptions. (The label is called a “black-box” warning because of its black border).

Physicians and parents took the warning seriously. From 2003 to 2005 the number of prescriptions for SSRIs for childhood and adolescent depression fell by 50%. This should have been a good thing, right? Perhaps not. New data shows that after 10 years of decline, the suicide rate in children and adolescents increased 18% in 2004, the most recent year for which there are data (Annual Summary of Vital Statistics: 2005. Pediatrics 119:345-360, 2007).

The data support the hypothesis that the risk of not prescribing Prozac for child and adolescent depression may, in fact, be more harmful than prescribing it. But we need to be careful to not over-interpret the data, for correlation does not prove causation. Now at least we know what the question is. Careful attention to study protocols will be needed to sort this one out, because suicidal thinking and behavior are difficult to classify at best.

The Immune System and Cancer

The July 2007 issue of Scientific American has an informative article on the role of the immune system in the development and spread of cancer. (A Malignant Flame. Scientific American July 2007, pp. 60-67). The article describes how our thinking has changed over the past decade or so.

It turns out that although the immune system sometimes helps to prevent the development and spread of cancer, at other times the immune system actually contributes to cancer development. This is particularly true of the non-specific immune defense mechanisms (they call it the “innate” immune system). The next generation of anti-cancer drugs may include some anti-inflammatory therapies, as well as traditional chemotherapies. Instructors with a special interest in cancer may wish to incorporate information in the article into their discussion of Chapter 18 – Cancer – in Human Biology, 5th ed.

The article points out that the immune system is also increasingly being implicated as a possible player in a whole host of chronic diseases, including heart disease, diabetes, Alzheimer’s disease, and schizophrenia and depression. More information is likely to be forthcoming on the role of the immune system in these diseases in the years to come.

A Biofuel Made From Fructose

Scientists can now make a fuel for your car from fructose, the sugar found in fruits such as apples and pears. The new fuel, called dimethlyfuran, has several advantages over ethanol: it has a higher energy content than ethanol, it repels water so that it is not diluted by moisture in the air, and it has a higher boiling point than ethanol so it stays a liquid more readily in the tank ethanol. The process for making the new experimental fuel is described in the June 21 issue of Nature.

However, like ethanol, the new fuel still has one distinct disadvantage; the starting material is food. Call it an incremental advance over ethanol if you like, but what we’d really like to do is to be able to make biofuels from the leftovers, not the food crops themselves. The real advance will come when we can make fuel for our cars from grass clippings, wheat chaff, or wood chips, reserving the apples and corn for our own consumption. That’s been a harder nut to crack, but researchers are working on it.

The U.S. Department of Energy has set a target of 30% of the 2004 demand for gasoline to be replaced by biofuels by 2030. Can we do it? This would be an exciting time to be a young researcher in the area of biofuels development. There may be some new career opportunities ahead for students interested in this and other environmental issues…