Friday, May 20, 2016

DFTD2: The Sequel

Tasmanian devil disease recently got curiouser when a graduate student identified a second cell line:
In March 2014, Murchison’s colleague Ruth Pye, a graduate student at the University of Tasmania, noticed something weird about a facial tumor taken from a devil captured just north of Hobart. Physically, it looked like DFTD; genetically, it was clearly something different. For example, DFTD cells have lost their X and Y sex chromosomes, both of which were present in the new tumor. Pye reasoned that this particular devil had spontaneously developed its own type of facial tumor that looked like DFTD, but wasn’t. It was a one-off.
Except, a few months later, she found the same genetically distinct tumor in a second devil from the same area. In both cases, the tumors bore absolutely no genetic resemblance to either DFTD or their respective hosts. These devils had developed a second type of contagious cancer.
They've found a total of eight infected devils and published their results this January.

Tuesday, January 28, 2014

The Bubonic Plague of Justinian

In The Guardian and elsewhere: a new journal article in the Lancet identifies the sixth-century Plague of Justinian as Yersinia pestis.
Professor Edward Holmes, from the University of Sydney, was one of the authors of the study, and said it was the oldest pathogen ever sequenced.
"This is the first complete genome from one of the most significant disease events in human history," he said.
The results showed the strains from the plague victims were distinct from those involved in the Black Death, the later pandemic which killed an estimated 60% of the European population.
The Justinianic strains appear to be an evolutionary “dead end” when compared with modern strains, and most likely originated from Asia and then spread to Europe along trade routes such as the Silk Road.

Monday, February 28, 2011

Plague and Hemochromatosis

I tweeted this a few days back, but today everyone decided to tell me about it. So here's the latest story about the scientist with undiagnosed hemochromatosis who died of the attenuated plague virus he was working with, a year and a half ago now.

Casadaban was conducting laboratory research on the bacterium that causes the plague when he became sick. The germ was genetically weakened and considered harmless to humans. It was considered so safe, Casadaban’s work with the live plague bacteria wasn’t noted when he fell ill, according to the CDC. A professor at the university for 30 years, by all accounts he had followed the proper safety protocols, the report said.
[...] An autopsy found the researcher had a medical condition called hemochromatosis, which causes an excessive buildup of iron in the body, according to the CDC report. The disorder affects about 1 in 400 people and goes unnoticed in about half of patients.
Casadaban’s illness is important because of the way the plague bacterium had been weakened. Yersinia pestis needs iron to survive. Normally it gets this iron by stealing it from a host’s body with proteins that bind to it and help break it down. To make the bacterium harmless, scientists genetically stripped it of the proteins needed to consume iron.

It seems hemochromatosis may not be the protection against Yersinia pestis its been made out to be.

Thursday, December 09, 2010

Mmm-mmm Melamine, Part MII

In the wake of the latest incident of melamine-contaminated milk in China, the Epoch Times reports that wealthy Chinese are now growing their own vegetables to ensure food safety.

In recent years, Chinese people have fought hard but ineffectively against poor food safety standards. There are simply too many tainted foods, from raw food products to cooking oil and food utensils. Waste oil, toxic chopsticks, and toxic lunch boxes can still be cleaned up, but there are three sources of poisoning which are most difficult to handle.

The three areas are: pesticides, food "additives" like melamine, and pollution.

Saturday, October 16, 2010

The End of Rinderpest

Via twitter: The Food and Agricultural Organization of the UN reports the likely eradication of rinderpest, a disease of cattle.

"The disease has affected Europe, Asia and Africa for centuries and has caused widespread famine and decimated millions of animals, both domestic and wild. In the 1880s, rinderpest caused losses of up to one million head of cattle in Russia and central Europe," said Diouf.
When it entered Africa in the nineteenth century, it decimated millions of heads of livestock and wildlife and triggered widespread famine. It is estimated that in that pandemic alone, up to one-third of the human population of Ethiopia died of starvation as a result. The last known outbreak of rinderpest occurred in 2001 in Kenya.
A joint FAO/OIE announcement of global rinderpest eradication is expected in mid-2011, pending a review of final official disease status reports from a handful of countries to the World Organisation for Animal Health (OIE).

Wikipedia is already referring to rinderpest in the past tense. PlagueBlog, however, cannot help wondering whether there's still some stashed in a freezer somewhere...

Thursday, September 16, 2010

New Prion Disease Discovered

Via ProMED-mail: last month ScienceDaily reported the publication of a journal article on a new spontaneous prion disease:

In 2008, Pierluigi Gambetti, MD, and Wen-Quan Zou, MD, PhD, with collaborators, reported the discovery of this novel disease, which affected patients who exhibit only one of the three types of the prion protein gene. In this follow-up study, they discovered that all three genetic groups can be affected also by this novel disease which now joins sCJD in displaying this feature. However, VPSPr is associated with an abnormal prion protein that exhibits characteristics very different from those of sCJD, as well as other prion diseases, suggesting that it may be caused by a different mechanism, perhaps more akin to other neurodegenerative diseases, such as Alzheimer's disease. This finding may exemplify, for the first time, the possibility that the prion protein affects the brain with different mechanisms.

Some claim there's a smoking cow behind this new variant.

Sunday, July 25, 2010

Childhood Schizophrenia

Via twitter: the LA Times reports on a tragic case of childhood schizophrenia.

Doctors and other mental health experts don't fully understand the disease, which has no cure. Jani's extreme early onset has left them almost helpless. The rate of onset in children 13 and under is about one in 30,000 to 50,000. In a national study of 110 children, only one was diagnosed as young as age 6.
"Child-onset schizophrenia is 20 to 30 times more severe than adult-onset schizophrenia," says Dr. Nitin Gogtay, a neurologist at the National Institute of Mental Health who helps direct the children's study, the largest such study in the world on the illness.
"Ninety-five percent of the time they are awake these kids are actively hallucinating," Gogtay says. "I don't think I've seen anything more devastating in all of medicine."
For Jani's parents, the most pressing issue is where Jani should live. She has been on the UCLA psych ward -- where she was placed during an emergency -- since Jan. 16. The ward is not designed for long-term care.