Wednesday, September 28, 2011

Clean Drinking Water Any Time, Anywhere

A large percentage of the world’s population does not have regular access to clean drinking water. Now there’s a possible solution; a personal water-filtering device called LifeStrawR. At about 12 inches in length. 1.2 inches in diameter and weighing less than two ounces, LifeStraw looks like a big fat drinking straw. But this “straw” removes nearly all bacteria, viruses, parasites, and even dirt from virtually any water supply. The device relies solely on the sucking action of the user to draw water through special filters. It’s effective for about 1,000 liters of water.

Currently, most LifeStraws are distributed through international aid agencies to people in poor countries who do not have access to clean water. There have been criticisms that the device is still a little too expensive for its intended market, but that may change over time, especially if similar devices eventually come on the market. In the U.S., LifeStraw is available only through several online sellers.

Disclaimer: I do not have a financial interest in LifeStraw. I just think it’s a clever solution to a worldwide public health problem.

Friday, September 23, 2011

Missing Fingerprints

Every person has a unique set of fingerprints, right? Well, not exactly. Researchers have documented a rare condition called adermatoglyphia in some members of a Swiss family, in which the usual fingertip skin ridges and swirls responsible for fingerprints are missing. Aptly, it has been dubbed “immigration delay disease” by the researchers who discovered it, because it causes all kinds of questions and concerns when the affected person travels internationally. The condition is caused by a mutation in a single gene that is expressed only in the skin.

An abstract of the research article can be downloaded for free.

Tuesday, September 13, 2011

The HPV Vaccine and the Presidential Debates

Governor Perry of Texas was criticized by Congresswoman Michelle Bachmann at the Republication presidential candidate’s debate last night for signing an executive order in Texas mandating that young girls be vaccinated against HPV, the sexually-transmitted virus that is responsible for most cases of cervical cancer. The vaccine is effective if it is given BEFORE a woman is sexually active. Health officials believe that if all women were vaccinated before becoming sexually active, cervical cancer rates would drop dramatically.

Congresswoman Bachmann took the position that the vaccine is unsafe. There is no evidence to support her claim, and her stance on the vaccine’s safety cost her some credibility today. However she did score some points when she reported that Governor Perry has received campaign funds from the drug company that makes the vaccine.

Congresswoman Bachmann also took the position that the government should not force vaccinations on citizens who don’t want them. That’s a valid position, of course. But she missed the fact that governor Perry’s “mandate” is actually not a firm mandate at all; parents can still choose to have their daughters opt out if they wish. And to his discredit, governor Perry failed to point the opt-out provision to her during the debate.

Ah, the presidential debates. Usually I’m bored by them, but perhaps this year will be different.

Antivenom Against Scorpion Stings

The FDA approved the first treatment for scorpion stings last month. Although most scorpion stings are not deadly, if left untreated in vulnerable patients such as small children they can occasionally lead to convulsions and death. Over 250,000 people are stung by scorpions each year – most of them in Mexico. In the U.S., scorpion stings are most common in Arizona.

The new treatment is an antivenom called Anascorp. A clinical study documenting its effectiveness was published in the May 14, 2009 issue of the New England Journal of Medicine – the article can be downloaded for free.

Friday, September 9, 2011

CO2 Aborption by Forests

It is often said that planting trees is good for the environment.  Trees absorb CO2 as they grow, removing CO2 from the atmosphere and thus reducing the impact of the burning of fossil fuels on global warming. But how much CO2 do trees actually absorb, compared to the amount of CO2 released by human activities?
According to estimates published recently in Science, between 2000 and 2007 the forests of the world absorbed an amount of CO2 equivalent to only 30% of the CO2 released by just two human activities (the burning of fossil fuels and the production of cement).  The other 70% generated by humans remained in the atmosphere (increasing the atmospheric CO2 concentration), or was absorbed by the world’s oceans. The 30% absorbed by trees represents a decrease from the 38% absorbed in the previous decade.  That's because CO2 release into the atmosphere continues to increase and because forest absorption decreased, most likely because of continued destruction of tropical forests.
Plant a tree if you wish.  But to solve the global warming problem we’ll need do a better job of preserving the world’s current forests, particularly in tropical regions.  We'll also need to continue to try to reduce human-caused CO2 production.