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By Charles Piller, Times Staff Writer
Vietnamese officials Wednesday ordered all chickens be slaughtered or removed from Ho Chi Minh City and banned the raising of poultry there through this year in an effort to quell the latest outbreak of bird flu.
Authorities previously banned live ducks and geese within the city because waterfowl can be infected with the bird flu virus without showing symptoms. A nationwide ban on the raising of waterfowl through June 30 was also put in place.
The ban on poultry is an attempt to keep Vietnam's commercial capital safe and augment the so-far uneven efforts to stamp out the disease nationally. The virus has killed 13 people in Vietnam since December.
No human cases have been reported in the country for more than two weeks, and seven of 35 affected provinces or cities have seen no new cases among birds for three weeks. But five of those provinces announced new poultry infections Sunday.
Michael Osterholm, a bird flu expert at the University of Minnesota, said banning live poultry within Ho Chi Minh City was of dubious value.
Birds "are either smuggled back in or never killed to begin with," he said.
Osterholm said the government must get tougher — restricting poultry farming to only secure areas and enforcing strict sanitary controls on workers and vehicles that enter those areas.
The avian influenza virus, formally known as H5N1, devastated much of the poultry industry in Southeast Asia last year. Since December, it has reemerged in more than half of Vietnam's provinces, as well as in Thailand and Cambodia.
About 1.5 million birds have been killed in Vietnam to prevent the spread of the disease.
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Two Vietnamese children who died in 2004 of diarrhoea and apparent encephalitis actually had H5N1 bird flu, British and Vietnamese scientists have reported.
The cases raise the frightening possibility that there have been far more human infections with H5N1 than thought, because many cases have been overlooked by doctors watching for the fever and cough of typical flu.
More human infections mean that H5N1 has had even more chances to adapt itself to humans. And if the virus often starts as gastrointestinal disease it will be very hard to detect against a high background incidence of such disorders in the region.
A four-year-old boy was taken to hospital in Ho Chi Minh City in February 2004 with severe diarrhoea and increasing drowsiness. He slipped into a coma and died. His nine-year-old sister had died with similar symptoms two weeks before. The boy had some symptoms of chest infection just before he died, but neither were suspected of having flu.
Samples from the boy's blood, throat, spinal fluid and faeces were sent to Oxford University, UK, as part of a project to find out which pathogens most frequently cause acute encephalitis, or brain inflammation, in Vietnam. After tests for all the suspected viruses came up negative, wider viral screening revealed H5N1 in all the samples.
There were no samples from the girl, but because her symptoms were so similar the authors suspect she died of the same infection. She also swam frequently in a canal used by domestic ducks, which can harbour the H5N1 infection.
"These cases have important clinical, scientific and public health implications," the scientists write in the New England Journal of Medicine . Severe gastrointestinal infections and encephalitis are common in children in the region, they note, both alone and together, making unusual clusters due to H5N1 hard to spot. Moreover, neither child started out with the high fever that had been considered a hallmark of the flu.
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GUATEMALA CITY - Environmental groups said Wednesday that they have discovered that banned genetically modified food — including a variety of corn forbidden for humans in the United States — is being handed out in U.N. food aid to Central America and the Caribbean.
A study backed by Friends of the Earth found that samples of World Food Program shipments collected in Guatemala included StarLink, a corn long ago pulled from the market in the United States because of concerns it could cause allergic reactions.
Discovery of StarLink corn in consumer products in the United States prompted several supermarket recalls in 2000 and 2001.
The study looked at 77 samples of imported corn in aid shipments or sold on the open market. Eighty percent was reported to include genetically modified material.
In Rome, World Food Program spokeswoman Anthea Web said that "the U.N. WHO, FAO and ourselves have found absolutely no evidence there is any health safety issue" with genetically modified foods. "They're eaten safely by millions of people everyday from Boston to Brussels to Buenos Aires."
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WASHINGTON (Reuters) - Aiming to circumvent President Bush's limits on the use of stem cells from human embryos, members of Congress on Wednesday introduced bills to allow federal funding of embryonic stem cell research.
Supporters from both major parties joined the coordinated introduction in the House of Representatives and Senate, saying they have given up on persuading Bush to change his policy.
"If the federal government doesn't act, we're going to have a patchwork of state laws -- and that's already happening," said Sen. Dianne Feinstein, a California Democrat helping to sponsor the bill.
"California, for instance, is launching a $3 billion initiative to fund cutting-edge stem cell research. In 2004, New Jersey created a $25 million embryonic stem cell research center," Feinstein said.
Wisconsin, Connecticut and New York also have funding measures in the works.
Supporters say stem cell research could transform medicine by providing ways to replace diseased tissue and treat or cure cancer, heart disease, Alzheimer's and diabetes.
Of several sources of stem cells, only those taken from early human embryos are controversial. Supporters of the research say they could be the most valuable sort of stem cell. Opponents including Bush say it is unethical to destroy a human embryo.
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Paroma Basu
Tackling a pressing and controversial technical barrier in stem cell biology, scientists at the WiCell Research Institute and UW-Madison have crafted a recipe that allows researchers to grow human embryonic stem cells in the absence of mouse-derived "feeder" cells, long thought to be a source of potential contamination for the therapeutically promising cells.
The new findings, which appear today (Feb. 17) in the journal Nature Methods, come on the heels of a recent University of California study showing that existing stem cell lines are already contaminated with an animal molecule. The potential threat of animal pathogens tainting human stem cell lines poses a problem for the safe clinical use of many, if not all, of the current cell lines now in use.
Until now, scientists have had to grow and sustain stem cells through the tedious daily task of generating mouse feeder cells from mouse embryos. Feeder cells, or fibroblasts, are connective tissue cells that form the matrix upon which stem cells grow.
The mouse feeder cells were an important ingredient in the mix of culture materials required to keep stem cells in their undifferentiated "blank slate" state. Embryonic stem cells are capable of forming any of the 220 tissues and cells in the human body and, in culture, are constantly trying to migrate down different developmental pathways. Maintaining stock cultures in their undifferentiated state is critical.
The feeder cell dogma now can be overturned, says lead investigator Ren-He Xu, a senior scientist at WiCell, a private, nonprofit research institute. "This work completely gets rid of the need for feeder cells," says Xu. "It also significantly reduces the daily labor of preparing the feeder cell-conditioned medium."
"It is important that the culture of human ES cells be simplified so that the average scientist can use them without extensive prior training," says James Thomson, a UW-Madison professor of anatomy and a co-author of the Nature Methods paper. "This development is a good step in that direction. Also, clinically, the feeder cells were one of the main sources of potential contamination with pathogens, so their elimination should improve safety. However, not all the animal components have been removed from the media yet, but this is an important step."
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Silicon breast implants could be replaced by tissue grown from a person's own stem cells within a decade, suggests new research.
Jeremy Mao of the University of Illinois, in Chicago, US, took human stem cells and used these to grow fat tissue using a biologically compatible scaffolding. He then successfully implanted the tissue into mice with an immune deficiency to prevent them from rejecting the implants. The implants had maintained their size and shape after four weeks.
"This is a project that builds on previous knowledge to develop a stem cell material that could be useful in society," says Mao. "It seems promising and could soon be making an impact."
Implants grown from stem cells could provide a safer alternative to silicon or saline implants, which can rupture and also interfere with breast cancer detection. They could also be aesthetically superior, keeping their shape and size for longer than artificial inserts, which typically shrink by 40% to 60% over many years, through spreading.
Eventually Mao says the technique could be used to develop more suitable tissue for reconstructive surgery as well as cosmetic augmentation.
The experiment involved key-hole surgery to extract mesenchymal stem cells from human bone marrow. These "master cells" can grow into various other different types of cells, including bone cartridge and fat. Mao coaxed them to develop into fat cells by mimicking the conditions that would cause this to happen in the human body.
The cells were then moulded into shape using a hydrogel scaffold and inserted into mice for a period of four weeks. Following implantation the eight mice involved in the study suffered no discernable ill effects and their implants maintained their original size and shape for the entire month. This is substantially longer than artificial inserts, which normally begin to deform after a week or two.
Mao believes breast implants grown from stem cells could be available within a decade. Ideally, the scaffold would disintegrate safely inside the body as the implant grows, he says.
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By Tara Godvin
States need to decide whether they are going to pursue expanded research on embryonic stem cells because of a ban on federal funding for most projects, said state Rep. Josh Green, vice chairman of the House Health Committee.
That question is becoming particularly important locally as the University of Hawaii's John A. Burns School of Medicine prepares to open its Kakaako campus in the spring with new research facilities.
But the answers require looking at complex moral, health, funding and legal issues that cannot be quickly unraveled during the course of a daily legislative hearing, said Green (D, Keauhou-Honokohau), also a medical doctor.
The committee deferred a bill yesterday that would have broadly defined the state's policy in favor of a resolution to form a task force led by the medical school.
Rep. Dennis Arakaki, committee chairman, said the bill was meant to spark discussion on the subject of stem cell research.
"We don't want to make the decision in a vacuum. We want to involve the community," Arakaki (D, Alewa Heights-Kalihi) said.
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The public is wrong to regard all profit-driven research as suspect
Dick Taverne
In science, as in much of life, it is believed that you get what you pay for. According to opinion polls, people do not trust scientists who work for industry because they only care about profits, or government scientists because they suspect them of trying to cover up the truth. Scientists who work for environmental NGOs are more highly regarded. Because they are trying to save the planet, people are ready to believe that what they say must be true. A House of Lords report, Science and Society, published in 2000, agreed that motives matter. It argued that science and scientists are not value-free, and therefore that scientists would command more trust "if they openly declare the values that underpin their work".
It all sounds very plausible, but mostly it is wrong. Scientists with the best of motives can produce bad science, just as scientists whose motives may be considered suspect can produce good science. An obvious example of the first was Rachel Carson, who, if not the patron saint, was at least the founding mother of modern environmentalism. Her book The Silent Spring was an inspiring account of the damage caused to our natural environment by the reckless spraying of pesticides, especially DDT.
However, Carson also claimed that DDT caused cancer and liver damage, claims for which there is no evidence but which led to an effective worldwide ban on the use of DDT that is proving disastrous. Her motives were pure; the science was wrong. DDT is the most effective agent ever invented for preventing insect-borne disease, which, according to the US National Academy of Sciences and the WHO, prevented over 50 million human deaths from malaria in about two decades. Although there is no evidence that DDT harms human health, some NGOs still demand a worldwide ban for that reason. Careless science cost lives.
Contrast the benefits that have resulted from the profit motive, a motive that is held to be suspect by the public. Multinationals, chief villains in the demonology of contemporary anti-capitalists, have developed antibiotics, vaccines that have eradicated many diseases like smallpox and polio, genetically modified insulin for diabetics, and plants such as GM insect-resistant cotton that have reduced the need for pesticides and so increased the income and improved the health of millions of small cotton farmers. The fact is that self-interest can benefit the public as effectively as philanthropy.
Motives are not irrelevant, and unselfish motives are rightly admired more than selfish ones. There are numerous examples of misconduct by big companies, and we should examine their claims critically and provide effective regulation to control abuses of power and ensure the safety of their products. Equally, we should not uncritically accept the claims of those who act from idealistic motives. NGOs inspired by the noble cause of protecting our environment often become careless about evidence and exaggerate risks to attract attention (and funds). Although every leading scientific academy has concluded that GM crops are at least as safe as conventional foods, this does not stop Greenpeace reiterating claims about the dangers of "Frankenfoods". Stephen Schneider, a climatologist, publicly justified distortion of evidence: "Because we are not just scientists but human beings as well ... we need to ... capture the public imagination ... So we have to offer up scary scenarios, make simplified dramatic statements, and make little mention of any doubts we have."
But in the end motives are irrelevant to the validity of science. It does not matter if a scientist wants to help mankind, get a new grant, win a Nobel prize or increase the profits of her company. It does not matter whether a researcher works for Monsanto or for Greenpeace. Results are no more to be trusted if the researcher declares his values and confesses that he beats his wife, believes in God, or is an Arsenal supporter. What matters is that the work has been peer-reviewed, that the findings are reproducible and that they last. If they do, they are good science. If not, not. Science itself is value-free. There are objective truths in science. We can now regard it as a fact that the Earth goes rounds the sun and that Darwinism explains the evolution of species.
A look at the history of science makes it evident how irrelevant the values of scientists are. Newton's passion for alchemy did not invalidate his discovery of the laws of gravitation. To quote Professor Fox of Rutger's University: "How was it relevant to Mendel's findings about peas that he was a white, European monk? They would have been just as valid if Mendel had been a Spanish-speaking, lesbian atheist."
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