Tuesday, May 26, 2009

Cleansing Blood With Magnets

Researchers at Harvard University are working on an innovative method for treating blood infections - drawing the bacteria out of blood with magnets. They mix infected blood with tiny antibody-coated magnetic spheres only 1/8 the size of red blood cells. The antibodies on the spheres attach to bacteria in the blood, and then the spheres and the bacteria are drawn off together using a powerful magnetic field.

In initial experiments the method removed up to 80% of the bacteria in small samples (10-20 ml) of blood. However, several questions remain to be unanswered: 1) Can the method be tooled up to cleanse the larger volume of blood in human patients? 2) Will reducing the bacterial or fungal load in a patient’s blood actually improve the patient’s recovery? 3) What might happen to the patient if a few magnetic beads are not removed from the blood before it is returned to the patient?

It may be awhile before we know if the method can be used safely and effectively to treat blood infections in human patients.

Saturday, May 16, 2009

What to Call Swine Flu

What should be the proper name for swine flu, now that we know that people are catching it from infected people, and not from swine? The World Health Organization has stopped calling it swine flu in favor of “influenza A (H1N1)”. But that name also applies to one of three strains of seasonal flu and to the deadly 1918-1919 Spanish flu (which didn’t even originate in Spain!) The U.S. Centers for Disease Control (CDC) calls it both “novel influenza A (H1N1)” and “H1N1 flu (swine flu)” on its website. Of course the Mexican government objects to calling it “Mexican flu”.

An article on what to call this virus appears this week in Science.

Thursday, May 14, 2009

Food Shortages and World Stability

Will the world ever simply run out of food? A recent article in Scientific American suggests that it won’t be that simple. The article’s author postulates that local or regional food shortages will be followed by starvation, which in turn could result in the collapse of governments and a rise in terrorism in poor countries and refugee problems in neighboring countries. Countries most likely to become the first failed states include Somalia, Sudan, Zimbabwe, and Chad, according to several international peace groups. Destabilization of governments could eventually spread worldwide, if food prices rose beyond the means of less wealthy nations.

Could such a scenario be prevented? The article goes on to say that in the long run, maintaining the world’s food supply will require drastic action, including solving the global warming problem, conserving fresh water, and stopping the current rate of topsoil losses. Otherwise, we may all be fighting each other for the last scraps of food sooner (perhaps in just hundreds or thousands of years) than we think. It’s something to think about.

Reference: “Could Food Shortages Bring Down Civilization?” Scientific American pp. 50-57, May, 2009.

Friday, May 8, 2009

Swine flu

It first appeared in Mexico in March. Popularly called swine flu, the H1N1 virus turns out to have a strange mixture of viral genes; 48% of its genes are from swine flu viruses, 34% are from avian flu viruses, and 17% are from human flu viruses. A key feature of the H1N1 virus is that it can be transmitted from human to human. By yesterday, swine flu had infected nearly 2,400 people, mostly in Mexico and the United States, killing 44. Where it came from, how far it will spread, and whether it will cause a pandemic remain unanswered questions. The World Health Organization’s influenza pandemic alert is currently at phase 5, just below a phase 6 full-alert.

There have been plenty of reports in the popular press about swine flu, some true, some not. For example, initial reports of a very high death rate from swine flu had to be revised downward once it was determined that many of the deaths attributed to swine flu were not caused by H1N1. Still, a death rate of nearly 2 % in healthy adults is quite high for any flu virus. Two percent of the world’s population is how many million people???

For authoritative updates about swine flu, try the news section of a magazine such as Science (see this week’s report) or the website of the World Health Organization.

Friday, May 1, 2009

Homo floresiensis made tools

Homo floresiensis, the species of extinct “little people” discovered recently on the island of Flores in Indonesia (see Human Biology 5th ed., pp. 520-521) apparently made and used stone tools, according to a recent report in Science. What makes this feat so impressive is that H. floresiensis has a very small brain by hominid standards. The discovery of H. floresiensis is causing anthropologists to re-think their long-standing hypothesis that the intelligence needed for making tools came only after, and as a consequence of, a large brain.

Modern humans who inhabited the area thousands of years later also made the same kinds of stone tools. Did modern humans interact with and learn from H. floresiensis, or did they develop the same tool-making techniques independently? No one knows for sure yet.