Tuesday, July 26, 2016

A New Map of the Cerebral Cortex

The map used in most textbooks to describe the functional regions of the cerebral cortex is admittedly rather old. Fortunately, it has just been updated. Using data collected as part of the Human Connectome Project, researchers examined over 1,200 brain scans looking at not one, but four features; architecture, function, connectivity and topography. They identified nearly 180 distinct areas of the cerebral cortex - more than double the number described in the past. The researchers also created a computer program that can recognize each area in an individual brain being studied.

What makes each region different and how they communicate with each other will likely be areas of active research for years to come. Of specific interest will be how the areas are involved in specific neurologic disorders. Dreaming big, we might imagine a future in which doctors could diagnose specific brain disorders from an MRI (magnetic resonance image), just by looking at changes in specific brain areas.

Thursday, July 21, 2016

We're Just One Step Away From a Superbug

The possibility that a strain of bacteria might develop total resistance to all known antibiotics (i.e., a superbug) continues to haunt us. Slowly but surely, more and more bacteria are increasing their resistance to antibiotics faster than we can create new antibiotics. No bacterium is completely resistant to all antibiotics yet, but a recent discovery suggests that we are just one step away from that point.

Right now, one of the most antibiotic-resistant of all bacteria is carbapenum-resistant Enterobacteriaceae (CRE for short). CRE has developed resistance to all antibiotics except an old antibiotic developed 50 years ago, called colistin. But now researchers have discovered a strain of E. coli bacteria that is resistant to colistin. If this strain of E. coli ever transfers its genetic material to CRE (the equivalent of bacterial mating), then we are in for real trouble.

Will it ever happen? No one knows. But bacteria have proven themselves to be highly adaptable. The era when antibiotics were the answer to bacterial infections may be coming to an end. We may have to find new ways to combat the bacteria of the future.

Saturday, July 16, 2016

Sexual Transmission of the Zika Virus

In healthy adults, the Zika virus causes only mild flu-like symptoms.  80% of infected adults never even know they are infected. However it's a dangerous virus nonetheless, because women who are infected during their pregnancies can give birth to infants with a birth defect called microcephaly.

When Zika first appeared in South America, it was believed that the virus was transmitted exclusively by mosquitoes that thrive in South American countries with warm, humid climates. However we now know that the Zika virus can be sexually transmitted. Until yesterday, all 14 documented cases of sexually transmitted infections in the U.S. had been caused by Zika-infected men (who infected their partners, either male or female). But now the CDC has reported the first documented case of transmission from an infected woman to her male partner in the U.S. The significance of sexual transmission is that it raises the possibility of an outbreak of Zika virtually anywhere in the world, not just in areas in which the Zika-transmitting mosquito is found.

Scientists are working feverishly on a vaccine to prevent Zika infections. It will take some time before one is available. In the meantime, pregnant women (and their male partners) should be aware of the dangers of traveling to countries where the Zika-transmitting mosquito is common.

Sunday, July 10, 2016

Nobel Laureates Support Genetically Modified Organisms (GMOs)

In an open letter published online, more than 100 Nobel Laureates are urging the environmental organization Greenpeace to stop their crusade against GMOs. Over 90% of the letter's signatories earned their Nobel prizes in the fields of physics, chemistry, or medicine. According to the letter's signatories, GMOs have been proven to be safe and have the potential to improve nutrition and feed a hungry world in the future. The letter suggests that opposition to GMOs is based on emotion and dogma, rather than facts. It concludes, "How many more poor people in the world must die before we consider this a 'crime against humanity'"?

The issue of the safety of GMOs is one of those areas in which the views of the public and of scientists are still far apart. A Pew Research Center study revealed last year that while 88% of scientists affiliated with the American Association for the Advancement of Science say that GMOs are generally safe, only 37% of the public thinks so.

In other related news, this month Vermont became the first state to require that food product labels indicate whether or not the product contains GMO ingredients. Other states are likely to follow suit. Clearly, the fight over GMOs is not over yet.

Monday, July 4, 2016

Prescription Contraceptives Via App or Website

It is now possible to obtain prescription contraceptives without ever having to schedule a visit to a doctor's office. A growing number of websites and apps allow you to fill out your personal and health information online or on an app and then have a videoconference or phone conversation with a licensed doctor; after approval of your prescription, your contraceptives (pills, patches, and in some cases even the morning-after pill) can be shipped directly to you.

Contraceptives are currently available only by prescription. Health professionals believe that contraceptives are so safe that they could be made available over-the-counter. However, over-the-counter availability would require approval from the FDA, an expensive and time-consuming effort most drug companies wish to avoid. In addition, the widespread availability of contraceptives without any medical approval at all would likely meet with opposition from conservative groups.

A few states allow pharmacists to write contraceptive prescriptions, but most do not. Web-and app- based services that connect patients to a doctor without a visit to a doctor' office are yet another way to make contraceptives more readily available. Health professionals hope that by making it easier for women to obtain contraceptives, these web-and app-based services will lead to a further reduction in the rate of unintended pregnancies.

For a description of some of the current websites and apps, see this article in the New York Times.

Monday, June 27, 2016

The Supreme Court Strikes Down a Texas Abortion Law

In a surprise ruling today, the U.S. Supreme Court struck down a Texas abortion access law (see this blog March 2, 2016) that severely restricted access to abortions in that state. The decision was a surprise because the court currently has only eight members, and it was widely believed that the court would be deadlocked on the issue until a ninth justice could be appointed after the presidential election.

Ever since Roe v. Wade, anti-abortionists have introduced legislation in many states designed to restrict access to abortion or make it more difficult. By striking down Texas's law, the court is signaling the states that they cannot restrict access to abortion simply by putting unnecessary obstacles in the way. In the majority opinion, Justice Breyer wrote, "We agree with the District Court that the surgical-center requirement, like the admitting-privileges requirement, provides few, if any, health benefits to women, poses a substantial obstacle to women seeking abortions, and constitutes an "undue burden" on their constitutional right to do so."

This new Supreme Court sets a fairly high bar for anti-abortion legislation; it must not introduce an "undue burden" on what is clearly a constitutional right.

Friday, June 24, 2016

Incorporating CO2 Into Solid Rock

Burning fossil fuels for energy releases CO2 gas into the atmosphere. Most of this CO2 stays in the atmosphere, where (as a greenhouse gas) it contributes to global warming and climate change. Some of it dissolves into the oceans, where it contributes to increased ocean acidity. These problems could be mitigated if the extra CO2 could be removed from the atmosphere somehow, but so far on one method has proven to be sufficiently cheap and effective. The most promising method so far has been to store the CO2 deep underground, in the hope that it will stay buried and not leak again to the Earth’s surface.

But now new research suggests that it may be possible to incorporate CO2 into minerals within solid rock, thereby sequestering it permanently. In a pilot study in Iceland, British researchers pumped 175 tons of CO2 into formations of basalt, a volcanic type of rock loaded with minerals that can combine readily with CO2. They found that within two years, 95% of the CO2 combined with these elements to become part of the rock itself. A larger study is underway to mineralize 10,000 tons of CO2.

One problem with this method is that so far it has only been shown to be effective in basalt. Although there are areas of basalt rock on Earth’s land surface, most of it is found on the ocean floor. At present, then, sequestering CO2 permanently in basalt may be too expensive to be the method of choice in most places. Still, if we ever finally have the will to do something about rising atmospheric CO2 levels, it’ll be nice to know that there’s a way.