Tuesday, September 25, 2007

Salmonella in Space

Via GeekPress, among others: The AP reports on the B-movie salmonella that came back deadlier after its trip on the space shuttle:

After 25 days, 40 percent of the mice given the Earth-bound salmonella were still alive, compared with just 10 percent of those dosed with the germs from space. And the researchers found it took about one-third as much of the space germs to kill half the mice, compared with the germs that had been on Earth.
The researchers found 167 genes had changed in the salmonella that went to space.
"That's the 64 million dollar question," Nickerson said. "We do not know with 100 percent certainty what the mechanism is of space flight that's inducing these changes."
However, they think it's a force called fluid shear.

"Being cultured in microgravity means the force of the liquid passing over the cells is low." The cells "are responding not to microgravity, but indirectly to microgravity in the low fluid shear effects."

Monday, September 24, 2007

Toxoplasmosis and You

Today's featured parasite is the stealthy and adaptable protozoan, Toxoplasma gondii.

This is the cat-litter bug that causes miscarriages and birth defects. The cat-loving parasite that lures rats to their deaths and causes traffic accidents. The latest schizophrenia suspect and a possible cause of epilepsy, psychosis, and migraines.

T. gondii may be making society rigid and neurotic, men more masculine, stupider, or more surly, and women more promiscuous. And if you think things are bad in the northern hemisphere, you should see the Brazilian strains.

About 16% 11% 33% of Americans are infected; infection rates are much higher in tropical countries (and France). Wikipedia tells the sad tale of Louis Wain, English cat artist, late-onset schizophrenic, and poster-child for the toxoplasmosis-schizophrenia connection.

T. gondii has its own book, conference, mugs and a blog, The Anti-Toxo, where you can follow mankind's losing battle with our one-celled masters.

Image by kqedquest. Some rights reserved.

Sunday, September 23, 2007

Ebola in the Congo

Via ProMED-mail: USA Today reports a total of nine confirmed cases of Ebola in the Democratic Republic of the Congo.

At least 167 people have died — though it is not clear how many of Ebola — in the affected region of Kasai Occidental over the past four months, and nearly 400 have fallen ill, according to Congolese health officials.
Christiana Salvi, a spokeswoman for the World Health Organization effort in Congo, said that the newest cases came from the same zone as the original confirmed samples.
She added that some of the 40-odd samples sent for testing have been negative for Ebola, but positive for other diseases like shigella — a diarrhea-like disease — or typhoid. Results from dozens more samples have yet to be released.

Friday, September 21, 2007

Bat Woman Found on Facebook

ProMED-mail reports that the mysterious woman who brought a rabid bat to the Toronto Wildlife Center has been found and inoculated:

Toronto Public Health has located the woman who had delivered an injured bat to the Toronto Wildlife Centre that later tested positive for rabies. Finding her proved to be very challenging as the Wildlife Centre did not have her updated demographic information. After several attempts to locate her, including a media release, proved to be unsuccessful, one of the communications staff at Toronto Public Health suggested using the website "Facebook.com".

If you come across an injured rodent of a populous and frequently rabid species, Plagueblog recommends that you walk away and let Darwin handle the situation.

Monday, September 17, 2007

Schizotypal Selection

Via John Hawks and the Four Stone Hearth Carnival of Anthropology: The Primate Diaries' explains Sapolsky's theory of selection for schizotypal personalities, possibly in shamans.

Several years ago Robert Sapolsky suggested that genes promoting schizophrenia may have been selected for in human evolution because some of them conferred benefits that outweighed the 1% of people worldwide that were disabled by the disorder. Like the sickle-cell trait that confers resistance to malaria (so long as you don’t receive two recessive alleles and develop full fledged sickle cell anemia) a partial schizophrenia may be beneficial in some way. He observed that relatives of schizophrenics have a high likelihood of “schizotypal personalities,” or a mild form of the disorder that just makes these people a little strange and allows them to see the world in a unique way. What if, he wondered, schizophrenia maintained itself in human populations because of selection for schizotypal personalites? As luck would have it, for a hundred years anthropologists had observed such individuals thriving in nearly every society they encountered: shamans.

Sunday, September 16, 2007

Leishmaniasis endemic in North Texas

Via ProMED-mail: UT Southwestern reports that Leishmania mexicana should be considered endemic in North as well as South Texas.

North Texas doctors must have a high index of suspicion and understand that this organism must now be considered endemic in this area, said Dr. Kent Aftergut, a clinical instructor of dermatology at UT Southwestern and in private practice at Methodist Charlton Medical Center.
“Luckily, all of the leishmaniasis cases in North Texas that have been cultured have grown Leishmania mexicana, which is less dangerous than other forms of the parasite,” he said. “It makes skin sores, but the infection doesn’t spread and become a full body disease like some of the others species of Leishmania. Usually, if patients have a normal immune system, the sores will resolve in six to 12 months and won’t make the patients ill.”

Monday, September 10, 2007

Bird Flu Hits 200

Via ProMED-mail: AFP reports Indonesia's 85th bird flu fatality, for a total of 200 bird flu deaths worldwide.

The plantation worker died at 2:00 pm (0700 GMT), the doctor treating him at the state general hospital in the city of Pekanbaru, Azizman Daad, told AFP.
A health ministry official earlier confirmed that the man was infected with the deadly H5N1 virus, after two tests came back positive.
H5N1 is endemic in birds across nearly all of Indonesia.
The archipelago nation has now reported 106 cases overall, including the 85 deaths.
Daad said it was not clear whether the man had come into contact with infected poultry, but he had bought two live chickens at a local market.