Scientific American - Health & Medicine

Mine Injuries Rise Right after Daylight Saving Time

Fri, 12 Mar 2010 13:30:08 EST

Don’t forget to move your clocks forward this weekend. And then don’t forget to be more careful in the days after you adjust your clocks. Because a recent study found that the hour of lost sleep was related to increased job-related injuries. Probably because sleepy workers were less alert. The work appeared last September in the Journal of Applied Psychology . [ see http://bit.ly/coie2b ] [More]

Gene Target Beats Oil Remedy

Fri, 12 Mar 2010 09:00:00 EST

The 1992 tearjerker Lorenzo’s Oil told the true story of one family’s struggle to save their son from X-linked adrenoleukodystrophy (ALD), a deadly degenerative brain disease. Unfortunately, over the ensuing years, the oil of the film’s title, a dietary supplement, has not panned out as the cure many people hoped it would be. Now a paper in the November 2009 issue of Science suggests that the long-sought cure may come from gene therapy--a famously hyped approach to treatment that tragically caused the death of a teenage experimental subject in 1999.

Since then, however, researchers have continued to cautiously pursue gene therapy for certain disorders with known genetic origins. ALD, for instance, is caused by mutations in a gene called ABCD1, leading to unusually high levels of a type of fatty acid that damages the material insulating some neurons. It affects about one in 20,000 six- to eight-year-old boys, leading to death before adolescence. The main treatment is still bone marrow transplantation: a risky procedure that relies on finding a suitable donor, explains Patrick Aubourg, a neurologist at France’s INSERM research institute.

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Readers Respond on "A Path to Sustainable Energy by 2030"

Fri, 12 Mar 2010 08:00:00 EST

Winds of Change I found it surprising that in “ A Path to Sustainable Energy by 2030 ,” Mark Z. Jacobson and Mark A. Delucchi do not mention the effects of the suggested energy sources on climate. The authors propose to absorb about six terawatts of energy from about 60 terawatts available in the wind, or about 10 percent of its total energy. Because the winds, at least near the U.S., usually flow around highs or lows, where the speed and related Coriolis force tend to maintain the pressure difference, I can easily envision that absorbing the energy will change the rate at which the pressure centers collapse. How this would change the weather, I do not know, but it must make a change to give us some of the energy. Possibly, the weather change would be an improvement, but as a believer in Murphy’s Law, I would be surprised. About 100 years ago dumping garbage into the ocean was justified because the oceans were infinite compared to the effect, so no one calculated how much was allowable. Let’s be smarter this time! Why not do the calculations before we cause more problems? [More]

Condoms for the World Cup and other ways to keep HIV at bay

Fri, 12 Mar 2010 07:15:00 EST

MIAMI--In three months hundreds of thousands of soccer fans are expected to descend on nine South African cities for the 2010 World Cup. But for so many visitors going to a country where more than 10 percent of the population is estimated to have HIV/AIDS, many public health experts are worried that the event will kick off a spike in transmission. South Africa, in turn, has responded by requesting one billion condoms for the year (many of which will be supplied by the U.K.)--more than twice as many as usual, the BBC noted . [More]

Researchers Gain New Insights into the Mystery of Thalidomide-Caused Birth Defects

Thu, 11 Mar 2010 14:00:00 EST

Half a century ago, thousands of pregnant women in 46 countries took a drug for morning sickness that would later be discovered to cause severe malformations in developing fetuses. Worldwide, roughly 10,000 affected children nicknamed "thalidomide babies" were born with multiple defects, including the characteristic shortened upper limbs (a condition known as phocomelia, Greek for "seal limbs"), before the drug was discontinued in 1961 after four years on the market.

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New Hope for Battling Brain Cancer (preview)

Thu, 11 Mar 2010 09:00:00 EST

In May 2006 Dwayne Berg woke up on a gurney in a Seattle emergency room, an IV in his arm and a team of doctors and nurses working him up. The last thing the 42-year-old financial executive could remember was running on a treadmill at his gym, part of his regular fitness regimen. He had suffered a seizure and tumbled off the machine, and although he had not hurt himself in the fall, doctors had asked for an MRI scan of his brain to see if they could find a cause for the seizure.

They did, and the news was not good: the scan showed a large mass in the left frontal lobe that turned out to be a malignant glioma, a brain cancer that is almost invariably fatal. Berg underwent standard treatment: an operation to remove the tumor, followed by chemotherapy and radiation to eradicate any cancer cells that might remain.

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Divining the Right Drug

Thu, 11 Mar 2010 09:00:00 EST

Imagine suffering from the crushing weight of major depression, then finally getting diagnosed and starting treatment with a drug--only to realize after two months that the medication, despite its unpleasant side effects, is not alleviating your depression. Unfortunately, this experience is far from rare: more than two thirds of patients with depression have no luck with the first medication they are prescribed and must also endure the withdrawal effects that come with discontinuing a drug before trying a new one. Finding the right treatment can prove a lengthy, painful process of trial and error. A new technology, however, may bypass this ordeal by gauging very early in a treatment regimen how well a drug is working based on the patient’s brain waves.

The technology, called quantitative electroencephalography (QEEG), measures a person’s brain-wave pattern with EEG and then compares it with a database of normal samples to detect abnormal function. In a study published in the September 2009 issue of the journal Psychiatry Research , scientists used QEEG to record brain activity in subjects with major depressive disorder before they began treatment, after one week on an antidepressant and after eight weeks on the drug--the period it takes such drugs to achieve full effect. Changes in the QEEG readout after just one week of medication predicted 74 percent of the time whether patients would experience either a recovery or a remission of symptoms by the end of eight weeks.

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Malaria rates drop in the Americas, but travelers still worry

Thu, 11 Mar 2010 08:00:00 EST

MIAMI--Malaria continues to be a global scourge, sickening some 300 million to 500 million people annually. Most of the resulting one million to three million malaria deaths occur in regions where it is highly endemic, such as sub-Saharan Africa and parts of south Asia. [More]

TB or Not TB?: Novel Detector Could Shorten Testing Times, Aid Treatment Efforts

Wed, 10 Mar 2010 15:30:00 EST

Tuberculosis is a serious public health challenge in the developing world, where the infection claims roughly two million lives each year, according to the World Health Organization (WHO) . Yet the disease, which is a leading killer of patients with HIV/AIDS, is cumbersome to detect, resulting in delayed or inappropriate treatment, greater spread of the infection and preventable deaths. [More]

Few Studies Compare the Efficacy of Medical Treatments

Wed, 10 Mar 2010 10:00:00 EST

The forward momentum of medical progress is manifest, it could be argued, in the $50 billion spent in 2008 on pharmaceutical research and development in the quest to bring new drugs to market. But little scientific or governmental infrastructure exists to ensure that each new treatment is actually an improvement over existing therapies--and to tease out what therapies are best for which patients. [More]

Message to Mosquitoes: Urine Trouble

Wed, 10 Mar 2010 09:50:08 EST

You know how uncomfortable it feels when you really have to go to the bathroom? And you have to hold it in? If researchers get their way, disease-carrying mosquitoes will spend their last moments being that uncomfortable. Cornell University scientists [Peter M. Piermarini, et al] have been trying to disrupt the life cycle of Aedes aegypti mosquitoes, which spread dengue fever. The mosquitoes pick up the virus when they feed on one human and transmit it in their saliva to their next victim.

There’s no vaccine for dengue, and no fully protective treatment. So the only recourse has been to figure out how to best kill the mosquitoes themselves. Here’s where urination comes in. When the mosquito takes a blood meal, it has to get rid of fluid and salt so it doesn’t overload--and die. Scientists have discovered a key protein in the renal tubes of these mosquitoes that helps with the necessary excretion. Blocking the protein keeps a mosquito from urinating. [See http://bit.ly/defrih ] Without whizzing, they become too heavy to fly away. The researchers say they’re thus more likely to be swatted or eaten. So look for new insecticides that stop mosquitoes from lightening their liquid load. With fatal results.

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End-of-Days Danger

Wed, 10 Mar 2010 08:00:00 EST

I don’t know how many e-mails I have received from children who are terrified that 2012 will somehow involve the end of life as we know it, all because of an unfounded fringe religious prophecy that has received mass-market exposure with the release of a recent Hollywood movie. I have tried to reassure those children (and not a few adults) that this date represents nothing more cosmically special than the year of the next presidential election.

Having said that, however, I just realized there might be a genuine connection between 2012 and an end-of-days menace!

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One's Enough: People Who Donate a Kidney Live Just as Long as Those Who Don't

Wed, 10 Mar 2010 07:00:00 EST

Every 30 minutes, all of the blood in our bodies is filtered through two fist-size kidneys. But diseases such as diabetes can cause them to fail, leading to a build-up of chemicals in the blood that without dialysis (mechanical blood filtration) or a kidney transplant would be fatal. And the wait for a new kidney can be long, unless someone you know is willing to give one of theirs to you. [More]

Does Getting Fat Protect against Fat?

Tue, 09 Mar 2010 08:10:08 EST

Everyone knows that obesity is bad for your health. Packing on the pounds, we’re told, leads to all sorts of medical problems: high cholesterol, insulin resistance, greater risk of diabetes and heart disease. But researchers at the University of Texas Southwestern Medical Center see things a little differently. In a paper in the journal Trends in Endocrinology and Metabolism [see http://bit.ly/bKaP33 ], they argue that being fat can actually protect us from these disorders. [More]

Seeing the Little Picture: Novel Nanocoating Gives Atomic Force Microscope Users a Better Look at Individual Molecules

Mon, 08 Mar 2010 15:20:00 EST

Spotting a disease in its earliest stages can help to facilitate its treatment greatly, yet telltale clues are often hidden at a scale too small to study accurately. This hindrance has some researchers looking for ways to use high-powered atomic force microscopes (AFMs) to study individual molecules for disease markers [More]

Another reason vitamin D is important: It gets T cells going

Sun, 07 Mar 2010 13:01:00 EST

Vitamin D deficiency has been linked to a rapidly expanding inventory of ailments--including heart disease , cancer and the common cold . A new discovery demonstrates how the vitamin plays a major role in keeping the body healthy in the first place, by allowing the immune system's T cells to start doing their jobs. [More]

Genetics in the Gut: Intestinal Microbes Could Drive Obesity and Other Health Issues

Fri, 05 Mar 2010 19:00:00 EST

Outnumbering our human cells by about 10 to one, the many minuscule microbes that live in and on our bodies are a big part of crucial everyday functions. The lion's share live in the intestinal tract, where they help fend off bad bacteria and aid in digesting our dinners. But as scientists use genetics to uncover what microbes are actually present and what they're doing in there, they are discovering that the bugs play an even larger role in human health than previously suspected--and perhaps at times exerting more influence than human genes themselves. [More]

Mosquitoes, Not Birds, Made West Nile National

Fri, 05 Mar 2010 09:40:08 EST

In 1999 West Nile virus infected its first American, in New York. By 2004, the disease had spread across the country. Researchers speculated that, for the disease to spread so far so quickly, birds must have helped. Some species could carry the disease and pass it on to mosquitoes, which would then infect humans. But a report published March 2nd in the journal Molecular Ecology [not available online as this episode was posted] says mosquitoes didn’t need a middleman. Or in this case, a middle bird. [More]

MIND Reviews: Temple Grandin

Fri, 05 Mar 2010 09:00:00 EST

Temple Grandin HBO Films [More]

Playing the Body Electric

Fri, 05 Mar 2010 09:00:00 EST

Each new generation of astronomers discovers that the universe is much bigger than their predecessors imagined. The same is also true of brain complexity. Every era’s most advanced technologies, when applied to the study of the brain, keep uncovering more layers of nested complexity, like a set of never ending Russian dolls. We now know that there are up to 1,000 different subtypes of nerve cells and supporting actors--the glia and astrocytes--within the nervous system. Each cell type is defined by its chemical constituents, neuronal morphology, synaptic architecture and input-output processing.

Different cell types are wired up in specific ways. For example, a deep layer 5 pyramidal neuron might snake its gossamer-thin output wire, the axon, to a subcortical target area while also extending a connection to an inhibitory local neuron. Understanding how the brain’s corticothalamic complex creates any one conscious sensation necessitates delineating these underlying circuits for the 100 billion cells in the brain.

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