Monday, January 29, 2007

Cat Flu

Via ProMED-mail: New Scientist reports on the implications of widespread H5N1 infection among Indonesia's cats.

Chairul Anwar Nidom of Airlangga University in Surabaya, Indonesia, told journalists last week that he had taken blood samples from 500 stray cats near poultry markets in four areas of Java, including the capital, Jakarta, and one area in Sumatra, all of which have recently had outbreaks of H5N1 in poultry and people.
Of these cats, 20 per cent carried antibodies to H5N1. This does not mean that they were still carrying the virus, only that they had been infected - probably through eating birds that had H5N1. Many other cats that were infected are likely to have died from the resulting illness, so many more than 20 per cent of the original cat populations may have acquired H5N1.
Osterhaus emphasises that the cat infections still pose a potential threat. "We know the 1918 pandemic was a bird flu virus that adapted to mammals in some intermediate mammalian host, possibly pigs," he says. "Maybe for H5N1 the intermediate host is cats." If similar percentages of cats are infected at every outbreak location, there must have been many thousands of cat infections since the virus emerged, compared to 267 confirmed cases in humans. Every sick cat is a chance for the virus to adapt, and with renewed outbreaks this year in birds, people or both in China, Indonesia, Japan, South Korea, Hong Kong, Vietnam, Thailand, Egypt and Nigeria, it is getting plenty of such chances.

Monday, January 22, 2007

A Cure for Cancer?

Via GeekPress: reports on dichloroacetate (DCA), a cheap, unpatented potential cancer drug:

Evangelos Michelakis of the University of Alberta in Edmonton, Canada, and his colleagues tested DCA on human cells cultured outside the body and found that it killed lung, breast and brain cancer cells, but not healthy cells. Tumours in rats deliberately infected with human cancer also shrank drastically when they were fed DCA-laced water for several weeks.
DCA attacks a unique feature of cancer cells: the fact that they make their energy throughout the main body of the cell, rather than in distinct organelles called mitochondria. This process, called glycolysis, is inefficient and uses up vast amounts of sugar.

Saturday, January 20, 2007

Playing with the Spanish Flu

Nature has a Web focus on the 1918 flu virus. For a free account of the latest on Frankenstein's reconstituted flu virus, see this press release from the University of Wisconsin-Madison:

By infecting monkeys with the virus, the team was able to show that the 1918 virus prompted a deadly respiratory infection that echoed historical accounts of how the disease claimed its victims.

Shocking! But wait, there's more:

Importantly, the new work shows that infection with the virus prompted an immune response that seems to derail the body's typical reaction to viral infection and instead unleashes an attack by the immune system on the lungs. As immune cells attack the respiratory system, the lungs fill with fluid and victims, in essence, drown.

Somehow I doubt anyone spent the last 90 years believing that the victims were drowning in liquid flu virus. But on a more optimistic note,

The same excessive immune reaction is characteristic of the deadly complications of H5N1 avian influenza, the strain of bird flu present in Asia and which has claimed nearly 150 human lives, but has not yet shown a capacity to spread easily among people.
"What we see with the 1918 virus in infected monkeys is also what we see with H5N1 viruses," Kawaoka says, suggesting that the ability to modulate immune response may be a shared feature of the most virulent influenza viruses.

At least these guys are playing with Frankenstein's Flu at biosafety level 4 this time:

In the new study, conducted in a high-level biosafety laboratory (BSL 4) at the Public Health Agency of Canada's National Microbiology Laboratory, seven primates were infected with the reconstructed 1918 virus. Clinical signs of disease were apparent within 24 hours of infection, and within eight days, euthanization was necessary. The rapid course of the disease mirrors how quickly the disease ran its course in its human victims in 1918.