Links for Keyword: Prions

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Heidi Ledford A man walks around the neighbourhood with his family, and stops to admire a particularly lovely house. He turns to his family and asks who built it. "You did," they reply. It was the first sign that something was wrong, he would later recount to researchers at the University of California, San Francisco. But it was another half a year before he developed the classical erratic behaviour and unsteady gait typical of Creutzfeldt-Jakob disease (CJD) — a neurodegenerative condition caused by an infectious protein called a prion. A diagnosis of CJD is a death sentence, and researchers around the world are looking for a cure. But that cure is unlikely to do much good if doctors can't diagnose the condition in its early stages, before the patient develops severe brain damage. Now, researchers have characterized the early signs of a similar prion disease in mice. In results presented this week in Neuron1, the researchers show that shutting off production of the pathogenic protein during these early stages allowed mice to not only survive, but also recover normal brain function. ©2007 Nature Publishing Group

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Link ID: 9906 - Posted: 06.24.2010

Paul Elias, Associated Press — Scientists have genetically engineered a dozen cows to be free from the proteins that cause mad cow disease, a breakthrough that may make the animals immune to the brain-wasting disease. An international team of researchers from the U.S. and Japan reported Sunday that they had "knocked out" the gene responsible for making the proteins, called prions. The disease didn't take hold when brain tissue from two of the genetically engineered cows was exposed to bad prions in the laboratory, they said. Experts said the work may offer another layer of security to people concerned about eating infected beef, although though any food derived from genetically engineered animals must first be approved by the Food and Drug Administration. "This research is a huge step forward for the use of animal biotechnology that benefits consumers," said Barbara Glenn of the Biotechnology Industry Organization, a Washington industry group that includes the company that sponsored the research as a member. "This a plus for consumers worldwide." The surviving cows are now being injected directly with mad cow disease, known as bovine spongiform encephalopathy, or BSE, to make certain the cattle are immune to it. © 2006 Discovery Communications Inc.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 9799 - Posted: 06.24.2010

Lauran Neergaard, Associated Press — Deer probably spread a brain-destroying illness called chronic wasting disease through their saliva, concludes a study that finally pins down a long-suspected culprit. The key was that Colorado researchers tested some special deer. Chronic wasting disease is in the same family of fatal brain illnesses as mad cow disease and its human equivalent. There is no evidence that people have ever caught chronic wasting disease from infected deer or elk. But CWD is unusual because, unlike its very hard-to-spread relatives, it seems to spread fairly easily from animal to animal. Scientists were not sure how, primarily because studying large wild animals is a logistical nightmare. The sheer stress of researchers handling a deer caught in the wild could kill it. Likewise, animals deliberately exposed to infections must be kept indoors so as not to spread disease, another stress for deer used to roaming. So Colorado State University researcher Edward Hoover turned to fawns hand-raised indoors in Georgia, which has not experienced chronic wasting disease. © 2006 Discovery Communications Inc.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 9442 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. The long lives that some former cannibals enjoy before succumbing to a brain-wasting disease suggest that many more humans will eventually die of mad cow disease, scientists said Thursday. But several experts in such illnesses, called prion diseases — which are blamed for killing New Guinea cannibals and British eaters of infected beef — disagreed with that frightening implication of the study, which is to be published Friday in The Lancet, a British medical journal. These experts praised the rigorous work the authors of the report did to confirm that kuru, a disease that once decimated highland tribes in New Guinea, can incubate for 50 years in a few genetically protected people. But the experts said they thought that the findings did not prove that there would be future waves of deaths among people who ate beef from prion-infected cows in the 1980's. "That's a provocative conclusion, but I'm not sure it's totally plausible," said Dr. David Westaway, a prion expert at the University of Toronto. Thus far, only about 160 people, mostly in Britain, have died of variant Creutzfeldt-Jakob disease, which humans get from cows that had bovine spongiform encephalopathy, or mad cow disease.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 9045 - Posted: 06.24.2010

Abnormal prion proteins are little understood disease agents involved in causing horrific brain-wasting diseases such as Creutzfeldt-Jacob disease in people, mad cow disease in cattle and chronic wasting disease in deer and elk. Now, new research suggests that a variant form of abnormal prion protein — one lacking an “anchor” into the cell membrane — may be unable to signal cells to start the lethal disease process, according to scientists at the Rocky Mountain Laboratories (RML), part of the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health. “This work provides novel insights into how prion and other neurodegenerative diseases develop and it provides tantalizing clues as to how we might delay or even prevent such diseases by preventing certain cellular interactions,” notes NIAID Director Anthony S. Fauci, M.D. A paper describing the research was released online today by the journal Science. Drawing on experimental concepts first developed at RML a decade ago, the research team exposed two groups of 6-week-old mice to different strains of the agent that causes scrapie, a brain-wasting disease of sheep. Within 150 days of being inoculated with the natural form of scrapie prion protein, all 70 mice in the control group showed visible signs of infection: twitching, emaciation and poor coordination. In contrast, the scientists observed 128 transgenic mice — those engineered to produce prion protein without a glycophosphoinositol (GPI) cell membrane anchor — for 500 to 600 days and saw no signs of scrapie disease. Subsequent electron microscopic examinations at UCSD, however, confirmed that they produced amyloid fibrils, an abnormal form of prion protein, and that they even had brain lesions. More remarkably, according to Dr. Chesebro, the diseased brain tissue resembled that found in Alzheimer’s disease rather than in scrapie.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 7445 - Posted: 06.24.2010

Nathan Seppa Even as scientist Stanley B. Prusiner was accepting a Nobel prize in 1997 for linking misfolded proteins to certain brain diseases, doubters were pointing out that no one had ever actually shown that these proteins—which Prusiner dubbed prions—could cause infection. Prusiner, a neurologist and biochemist at the University of California, San Francisco (UCSF), and his colleagues now report results that could silence many of his critics. The study, published in the July 30 Science, shows that purified prions can cause disease when injected into the brains of genetically engineered mice. Previous work by Prusiner and others had implicated prions in human-brain ailments that include Creutzfeldt-Jakob disease and kuru, as well as mad cow disease, chronic wasting disease in deer and elk, and scrapie in sheep. Suggesting that proteins, misfolded or not, can be infectious is "a radical notion," says Neil R. Cashman of the University of Toronto. Nevertheless, to Cashman and others, the new research supplies the proof. Copyright ©2004 Science Service.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 5915 - Posted: 06.24.2010

Paul Brown In December 2003, the U.S. Department of Agriculture discovered a case of bovine spongiform encephalopathy (BSE), often called mad-cow disease, in a dairy cow from Washington state. The news was more than a little disturbing to the American cattle industry. The mad-cow scare had previously devastated the cattle business in the few countries where BSE had been reported, especially Great Britain and Canada. The Canadian cattle industry has yet to recover from the discovery of BSE in a single cow on an Alberta farm in May of last year. A 400-kilogram cow that used to fetch 500 Canadian dollars on the open market now sells for as little as 79 Canadian cents—less than the price of a fast-food burger. The economic fallout is, of course, a consequence of the discovery in 1996 that mad-cow disease could cross the species barrier to inflict human beings with variant Creutzfeldt-Jakob disease (vCJD). This disease is characterized by a progression of psychiatric and neurological symptoms that culminate in death, usually a year or two after the onset of the first indications of illness. As of May 2000, a total of 155 cases of vCJD had been identified: 144 in Great Britain (where the outbreak began), 6 in France, 1 in Ireland, and 1 in Italy. Additional single victims in Hong Kong, Canada and the U.S. were infected in the U.K., where they had been residing during the years of peak risk, in the late 1980s or early 1990s. The extraordinary commercial and public-health consequences of BSE, as well as the near-global distribution of products derived from cattle, have generated a considerable amount of attention from industry, government and the general public. As a result, there is a daunting volume of information—not all of it reliable—surrounding the nature of mad-cow disease. © Sigma Xi, The Scientific Research Society

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 5640 - Posted: 06.24.2010

By THE ASSOCIATED PRESS WASHINGTON, — Canadian officials have traced to two mills the feed that probably caused North America's two cases of mad cow disease, one in Canada last May and the other in the United States in December. The feed from the Canadian mills could have contained infectious protein from imported British cattle, said Dr. George Luterbach, an official of a mad cow working group in the Canadian Food Inspection Agency. Canadian law prohibits disclosing the identity of the mills, Dr. Luterbach said. Canada reported its only case of the disease, also known as bovine spongiform encephalopathy, or B.S.E., in an animal on a farm in Alberta. The United States followed with an announcement that a cow in Mabton, Wash., had the disease. Both animals had been raised on farms in Alberta, and both ate feed containing meat and bone meal while they were calves. Copyright 2004 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 5161 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. The government has begun a criminal investigation into whether documents were falsified in the lone case of mad cow disease found in the United States, the Agriculture Department's inspector general said yesterday. The official, Phyllis K. Fong, told a House appropriations subcommittee that the investigation focused on whether the Holstein dairy cow was a "downer" — a cow too sick or injured to walk — when it was slaughtered on Dec. 9 at Vern's Moses Lake Meats in Washington State. The inquiry was "based on allegations that were reported in the media in early February concerning possible alteration of official records," Ms. Fong said. She declined to identify any targets of the investigation. Copyright 2004 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 5079 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. A new form of mad cow disease has been found in Italy, according to a study released yesterday, and scientists believe that it may be the cause of some cases of human brain-wasting disease. While the strain has been found in only two Italian cows, both apparently healthy, scientists in Europe and the United States said it should provide new impetus in Washington for the Department of Agriculture to adopt the more sensitive rapid tests used in Europe because it may not show up in those used in the United States. Along with the Italian study, there have been recent reports of unusual types of mad cow disease in France and Japan, and scientists say the discovery of new forms suggests that many cases of "sporadic" human disease — by far the most common kind, responsible for about 300 deaths a year in the United States — are not spontaneous at all, but come from eating animals. Copyright 2004 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 4986 - Posted: 06.24.2010

By ALICIA AULT SILVER SPRING, Md., — Joining a growing chorus, federal advisers on Friday urged the government to increase testing for mad cow disease greatly to better gauge if the United States has a problem, and if so, how widespread it is. The panelists said that without that data, there was no way to minimize the risk to humans who might be exposed by eating meat, or through drugs, vaccines, cosmetics and dietary supplements that contain raw materials from cattle. "We have to know what the risk is, and whether we could contain it or whether we could stop it," said Dr. Stephen DeArmond, a member of the Food and Drug Administration panel, which met here on Thursday and Friday. Dr. DeArmond is a mad cow disease expert at the University of California, San Francisco. Copyright 2004 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 4970 - Posted: 06.24.2010

By SANDRA BLAKESLEE — If Americans develop a disease like the human form of mad cow that worries millions of Europeans, Dr. Pierluigi Gambetti may be the man to find it. Dr. Gambetti, an Italian neuropathologist whose mild manner and penchant for cardigan sweaters make him look a bit like Mr. Rogers, is director of the National Prion Disease Pathology Surveillance Center at Case Western Reserve University here. For the last five years, he and his staff have been collecting brain tissue from people all over the country who die from mysterious, rapidly progressive neurological disease. Now that the first case of a cow infected with mad cow disease has been discovered in the United States, Dr. Gambetti's work has taken on new urgency. Copyright 2004 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 4865 - Posted: 06.24.2010

By MATTHEW L. WALD and ERIC LICHTBLAU WASHINGTON, — A sick cow slaughtered about two weeks ago near Yakima, Wash., has tested positive for mad cow disease in early laboratory results, the first such case in the United States, the secretary of agriculture said on Tuesday. Shortly after the announcement, Japan said it was banning imports of American beef. The South Korean agriculture ministry said in a statement that South Korea was also halting American beef imports and that it was pulling American beef products off supermarket shelves. [On Wednesday morning, Russia, Thailand and Hong Kong also announced that they too were banning imports of American beef products.] Copyright 2003 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 4734 - Posted: 06.24.2010

Susan Milius As Canadian health officials press on in their investigation of mad cow disease within their borders and other countries bar Canadian beef, scientists are taking disparate approaches to developing defenses against such brain diseases. Researchers in the United Kingdom studying livestock that resist so-called transmissible spongiform encephalopathies report mixed results. Although earlier tests had found some sheep resistant to infection by natural routes, extreme challenges—injections of diseased material directly into the brain—brought on the disease in 3 out of 19 animals, says Fiona Houston of the Institute for Animal Health in Newbury in the May 29 Nature. Looking at meat treatments, U.S. and Italian researchers are blasting hot dogs with pressure and heat to inactivate agents for a spongiform encephalopathy. The researchers report in the May 13 Proceedings of the National Academy of Sciences that they have quashed risk of infection from the food. Copyright ©2003 Science Service.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 3861 - Posted: 06.24.2010

By MATT RIDLEY VANCOUVER, British Columbia — Alarming as it was to learn last week that mad cow disease had appeared in North America, the news could have been far worse. Thanks to advances in bioscience and technology, we can now stop an epidemic like mad cow disease, and its human offshoot, Creutzfeldt-Jakob disease, in its tracks. Little is known so far about the particular case discovered last week in western Canada. The black Angus cow was 6 to 8 years old, officials said, and had lived on six ranches and had had five or more calves. Nine herds have been quarantined so far. In Britain, the mad cow epidemic that began in the late 1980's infected nearly 200,000 cattle before it was halted, and more than 120 people died through infected meat. The episode shattered the British public's confidence in government reassurances about food safety, and contributed heavily to British and European refusal to accept official assurances about the safety of genetically modified crops. The environmental movement managed to make much of this distrust, using it to promote fears of interfering with nature, whether through technology or industrial agriculture. Copyright 2003 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 3841 - Posted: 06.24.2010

By CLIFFORD KRAUSS with SANDRA BLAKESLEE VANCOUVER, British Columbia, — Mad cow disease was diagnosed in a cow in Canada today, and United States health authorities immediately placed a ban on imports of beef, cattle and animal feed from Canada. The report shocked ranchers through much of western Canada, where trading in livestock was immediately halted because of plummeting cattle prices. The shock waves spread through the financial markets, where prices in many Canadian and American meat and restaurant companies fell sharply. Canadian authorities stressed that only one cow out of Canada's total cattle population of 3.6 million was found to be sick and there was no immediate evidence that the disease had spread among livestock or humans. Copyright 2003 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
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Link ID: 3828 - Posted: 06.24.2010

By NICHOLAS WADE Deep in the recesses of the human heart, lurking guiltily beneath the threshold of consciousness, there may lie a depraved craving — for the forbidden taste of human flesh. The basis for this morbid accusation, made by a team of researchers in London, is a genetic signature, found almost worldwide, that points to a long history of cannibalism. The signature is one that protects the bearer from infection by prions, proteins that can be transmitted in infected meat and attack the nerve cells of the brain. Prions can be acquired from eating infected animals, as in the case of the mad cow disease that in 1996 spread to people in England, but they spread even more easily through eating infected humans. This fact is known from study of the Fore, a tribe in the eastern highlands of Papua New Guinea that started to practice ritual cannibalism at the end of the 19th century. Dr. D. Carleton Gajdusek, who later received a Nobel Prize for his work, noticed that the Fore were being devastated by a neurodegenerative disease known as kuru. He linked it with their practice of eating the brains of their dead in mortuary feasts. When the feasts were banned by Australian authorities in the mid-1950's, the incidence of kuru declined, and no cases have appeared in anyone born after that time. Copyright 2003 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
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Link ID: 3681 - Posted: 06.24.2010

— Howard Hughes Medical Institute researchers have found that a gene mutation that produces a black coat color in mice also causes degeneration of neurons similar to that observed in prion-caused diseases, such as Creutzfeldt-Jakob disease and “mad cow disease.” The scientists say that their findings could improve understanding of how the renegade proteins, called prions, destroy the brains of infected humans, cattle and sheep. In an article published in the January 31, 2003, issue of the journal Science, researchers led by Howard Hughes Medical Institute investigator Gregory Barsh reported that a gene mutation in mahoganoid mice causes neural damage that closely resembles that observed in spongiform encephalopathies. The work was carried out by Lin He and Teresa Gunn, graduate student and former postdoctoral fellow with Barsh, respectively, and also involved collaboration with the University of Michigan School of Medicine. Gunn, He, and Barsh began looking at the effects of mahoganoid mutation on neural development after their studies of another mutation in a similar coat-color gene, called Attractin, turned up some intriguing results. ©2003 Howard Hughes Medical Institute

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Link ID: 3371 - Posted: 06.24.2010

Researchers puzzle over brain illness in North American wildlife Susan Milius This autumn, the nation's big-game hunters are lifting their guns and bows in the service of science. They're collecting the biggest sample ever of deer and elk brains—predicted to total 200,000—to test for a once-obscure wildlife disease that's become the stuff of headlines and headaches coast-to-coast. So-called chronic wasting disease strikes mule deer, white-tailed deer, and elk. It riddles the brain with tiny holes as the victim slowly withers and dies. Once found in the wild only in an area intersecting Colorado, Wyoming, and Nebraska, the disease appears to be spreading. This year, it turned up in wild herds in South Dakota, New Mexico, and Canada and jumped all the way to Wisconsin and Illinois. This disease belongs to the same class of maladies as mad cow disease, which appeared in Britain in 1986 and about a decade later, showed up in people who had eaten tainted meat. Last year, some 11 million people hunted deer and elk in the United States, and many more helped them eat their prizes. So far, the news for hunters looks reassuring. Several weighty groups, including a panel from the World Health Organization, have concluded that there's no evidence so far that people can catch chronic wasting disease. From Science News, Vol. 162, No. 22, Nov. 30, 2002, p. 346. Copyright ©2002 Science Service. All rights reserved.

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 3086 - Posted: 06.24.2010

By SANDRA BLAKESLEE DENVER, — Wildlife experts from the United States and Canada are meeting here to discuss strategies for containing the spread of chronic wasting disease, the variant of mad cow disease that kills deer and elk. The malady, once found only in the brushy foothills near Fort Collins, Colo., has now been identified in both captive and wild herds of deer and elk in Kansas, Montana, Nebraska, New Mexico, Oklahoma, South Dakota, Wisconsin and Wyoming and the Canadian provinces of Saskatchewan and Alberta. Some states, like New Mexico, have found only one infected animal in the wild. But Saskatchewan, for example, has diagnosed the disease in more than 100 captive animals bred for their meat and antlers. Copyright 2002 The New York Times Company

Related chapters from BP7e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 2432 - Posted: 06.24.2010