Mmm-mmm Cadmium, Part I

Via ProMED-mail: the Associated Press found cadmium in children's jewelry imported to the US from China. The LA Times reports:

For China's low-cost jewelry makers, it was an open trade secret: The metal cadmium is shiny, strong and malleable at low temperatures, regardless of its health hazards. And it's cheap.
Despite the risks, manufacturers in factories ringing this city on China's east coast say their top priority is profit. So offering cut-rate goods often means using lower quality materials, including cadmium, which is known to cause cancer.
"Business is business, and it's all up to our client," said He Huihua, manager of the Suiyuan Jewelry Shop at International Trade City in Yiwu[...]
Asked what he thought about the health risks associated with cadmium and other toxic metals, He said: "I can't be overly concerned about that."

PlagueBlog recommends a trade embargo.

Mmm-mmm Melamine, Part M

Via ProMED-mail: another melamine scandal has broken in China, once again belatedly, and once again involving tainted milk. The Wall Street Journal reports that the two-month investigation of Shanghai Panda Dairy Company began almost a year ago.

Shanghai Panda, one of the nation's smaller dairies, was among 22 companies originally implicated in the 2008 scandal and was briefly shut by quality inspectors.
Now, among the allegations against the company are that instead of destroying its melamine-tainted product that had been recalled in 2008, Shanghai Panda reconstituted the milk into new products.

Lovely.

Prion Evolution

Ed Yong discusses prion evolution in his blog at ScienceBlogs:

Jiali Li from the Scripps Institute in Florida has found that prions - the infectious proteins behind mad cow disease, CJD and kuru - are capable of Darwinian evolution, all without a single strand of DNA or its sister molecule RNA.
Prions are rogue version of a protein called PrP. Like all proteins, they are made up of chains of amino acids that fold into a complex three-dimensional structure. Prions are versions of PrP that have folded incorrectly and this misfolded form, called PrPSc, is social, evangelical and murderous. It converts normal prion proteins into a likeness of its abnormal self, and it rapidly gathers together in large clumps that damage and kill surrounding tissues.
Li has found that variation can creep into populations of initially identical prions. Their amino acid sequence stays the same but their already abnormal structures become increasingly twisted. These "mutant" forms have varying degrees of success in different environments. Some do well in brain tissue; others thrive in other types of cell. In each case, natural selection culls the least successful ones. The survivors pass on their structure to the "next generation", by altering the folds of normal prion proteins.

Marburg Reaches the US

Via ProMED-mail: the CDC reports on an imported case of Marburg hemorrhagic fever in Colorado last year. A bat-cave tourist came home from Uganda in January 2008 and exhibited the less dramatic symptoms of Marburg. Tests for Marburg came back negative, but she was retested six months later at her own request and Marburg was confirmed, both then and in the original sample. (It seems the CDC has a big freezer.)

On January 22, 2009, CDC notified the World Health Organization and Uganda Ministry of Health of the imported MHF case. The Python Cave had already been closed to visitors in July 2008, during the response to the Dutch MHF case. CDPHE and CDC conducted a public health investigation during January--February 2009. Interviews were conducted with the patient and her spouse, the patient's medical records were reviewed, and a retrospective contact investigation was conducted to identify possible secondary transmission. A contact was defined as a person who had physical contact with the patient, her body fluids, or contaminated materials or was in the same room as the patient during her acute illness (January 4--19, 2008). Contacts included health-care workers (including health-care providers, housekeeping staff, and hospital laboratory staff), commercial laboratory staff, and social contacts.

No explanation for the six month delay in reporting to the WHO was provided, nor for the further year it took this information to appear on the CDC site. One imagines that it may be due to the fact that the victim, though now recovered, was quite ill with Marburg, including eleven days of hospitalization in "a community hospital," and no notable precautions were taken. The story has medical thriller written all over it. Or perhaps the bird flu/H1N1 story was considered to be enough for the public to panic about at the time.

PlagueBlog recommends against bat-cave tourism of any sort, locally or in Africa.

Tis the Season

It's time again for ProMED-mail's Internet-a-thon. You can make donations at their website.

Non-Plushy Giant Virus

Via twitter: the AFP reports that French scientists have discovered a (non-plushy) giant virus.

With a genome of 368,000 basic pairs, Marseillevirus is the fifth biggest virus ever sequenced and has a diametre of 250 nanometres (around 250 millionth of a millimetre, according the a report by Raoult's for the French National Centre for Scientific Research (CNRS).
The DNA of the giant virus contains material from different sources including plant and animal matter, bacteria and other giant viruses such as the Mimivirus, the report said.
"There is a mechanism of permanent creation going on in amoeba producing a new repertoire of viruses and predisposing giant viruses to become pathogens once they specialise", Raoult said.

Some interesting statements about Darwin follow, which one hopes are merely mistranslated.

Microevolutionary Defenses against Kuru

Via Twitter: Razib at ScienceBlogs reports on cannibals, kuru, and microevolution.

127V is extremely efficacious against fatality due to kuru. Looking through the pedigrees in a region of very high kuru exposure the researchers found that of the individuals who carried 127V, only 1 out of 36 in the parent generation died of kuru. By contrast, 33 of 218 parents from those carrying 127G only (the modal allele) had died of kuru (some of these presumably would also have carried the protective variant of 129). When the researchers looked at the 127V haplotype, the nature of the variation around this mutation implied that a common ancestor existed ~10 generations ago, with a 95% confidence interval 7 to 15 generations. That means that all of the copies of 127V extant today in the Fore descend from one particular copy present on the order of 250 years in the past within the population.

Double Dipping

Via ProMED-mail: the Charleston Daily Mail reports on a pediatrician who came down with swine flu twice.

Parsons says she's spoken with CDC representatives about the results, and they said the double infection isn't all that unbelievable.
"They said this happens every year with seasonal flu, so there's no reason to expect that it wouldn't happen with swine flu," Parsons said. "Every flu strain can change a little bit."
The pediatrician says there may have been a tiny change in the virus that stopped her immune system from recognizing it or her body never built up immunity to it.

Iron and MS

Via Twitter: The Globe and Mail reports on a researcher's personal obsession that led to an unexpected treatment for multiple sclerosis.

Fighting for his wife's health, Dr. Zamboni looked for answers in the medical literature. He found repeated references, dating back a century, to excess iron as a possible cause of MS. The heavy metal can cause inflammation and cell death, hallmarks of the disease. The vascular surgeon was intrigued – coincidentally, he had been researching how iron buildup damages blood vessels in the legs, and wondered if there could be a similar problem in the blood vessels of the brain.
Using ultrasound to examine the vessels leading in and out of the brain, Dr. Zamboni made a startling find: In more than 90 per cent of people with multiple sclerosis, including his spouse, the veins draining blood from the brain were malformed or blocked. In people without MS, they were not.
He hypothesized that iron was damaging the blood vessels and allowing the heavy metal, along with other unwelcome cells, to cross the crucial brain-blood barrier. (The barrier keeps blood and cerebrospinal fluid separate. In MS, immune cells cross the blood-brain barrier, where they destroy myelin, a crucial sheathing on nerves.)
More striking still was that, when Dr. Zamboni performed a simple operation to unclog veins and get blood flowing normally again, many of the symptoms of MS disappeared.

BU's Leaky Biolabs

Via ProMED-mail: the Boston Globe reports on another BU researcher who accidentally brought his work home with him.

The genetic tests, conducted at the state laboratory in Jamaica Plain, compared a blood sample from the researcher with bacterial matter recovered from the lab where he was working on BU’s South End campus. “The bottom line,’’ said Dr. Anita Barry, top disease tracker at the Boston Public Health Commission, “is they matched.’’
The analysis erased any doubt about what caused the researcher to become sick last month and intensified investigations into precisely how he was exposed to a germ known as Neisseria meningitidis, which can cause meningitis.
The city’s biological lab safety division will review safety procedures in BU’s medical labs, to ensure that the school is doing everything possible to minimize researchers’ exposure to pathogens, Barry said.

I thought they did that last time.

PlagueBlog recommends moving to the suburbs before the new BU biolab opens downtown. And by "suburbs" I mean Maine.

Accidental Vaccinia

Via ProMED-mail: the CDC reports on a case of vaccinia infection in an immunocompromised woman who handled rabies vaccine bait, in which a genetically modified version of variola's little sister is used. There's much more on the story and the history of vaccinia at ScienceBlogs.

Atypical Scrapie

Via ProMED-mail: the New Zealand Ministry of Agriculture and Forestry reports on a case of atypical scrapie.

MAFBNZ Principal International Adviser Dr Stuart MacDiarmid says global knowledge about atypical scrapie/Nor 98 is evolving. The widely accepted mainstream scientific view is that it occurs spontaneously or naturally in very small numbers of older sheep in all sheep populations around the world.
"This positive detection of atypical scrapie/Nor 98 in a sheep from New Zealand's national flock reinforces that view. Every country that has conducted sufficient surveillance for atypical scrapie/Nor 98 has found it in their flocks. This includes most Scandinavian and EU countries, the UK, the USA and Canada," he says.
The detection does not change New Zealand's status as free from scrapie.

Mad Elk and Mad Fish

Via ProMED-mail: last month, the New York Times reported on the spread of CWD among elk via fecal-oral transmission, due to preclinical shedding of prions.

Dr. Aiken said prions tended to bind to clay in soil and to persist indefinitely. When deer graze on infected dirt, prions that are tightly bound to clay will persist for long periods in their intestinal regions. So there is no chance chronic wasting disease will be eradicated, he said. Outside the laboratory, nothing can inactivate prions bound to soil. They are also impervious to radiation.

Also, Practical Fish Keeping reported last month on a study of mad cow and scrapie transmissibility to fish:

The authors found that while the bream never displayed clinical signs of spongiform encephelopathies during the study period, the brains of TSE-fed fish sampled two years after challenge showed signs of neurodegeneration and accumulation of deposits that reacted positively with antibodies raised against sea bream PrP. The control groups, fed with brains from uninfected animals, showed no such signs.

Swine Flu Shots vs. Seasonal Flu Shots

Via ProMED-mail: temperatures are still high in Canada, where the Globe and Mail reports that two and a half provinces have rebelled against seasonal flu shots in reaction to as-yet-unpublished research showing that a seasonal flu shot makes people more susceptible to swine flu.

The hodge-podge of vaccination strategies comes after a controversial, unpublished study suggested that people under 50 are twice as likely to contract the H1N1 virus if they have received a seasonal flu shot compared to unvaccinated people.
With no data revealing the optimal way of rolling out vaccines against the looming double threat of seasonal flu and the pandemic swine flu virus, the abrupt changes by provinces and territories could create disarray in inoculation programs, with fewer people turning up for either shot, potentially resulting in more cases of severe illness.
New Brunswick's public health authorities, skeptical about the science behind the Canadian study, have moved up seasonal flu shots for all their residents to October before proceeding to the pandemic vaccine campaign. Meanwhile, Quebec and Nunavut are deferring their seasonal flu campaigns until after their H1N1 mass vaccination clinics.

Shaken Baby Syndrome

Radley Balko at Reason Online reports on growing doubts about "shaken baby syndrome":

The phrase shaken baby syndrome entered the pop culture lexicon in 1997, when British au pair Louise Woodward was convicted of involuntary manslaughter in the death of Massachusetts infant Matthew Eappen. At the time, the medical community almost universally agreed on the symptoms of SBS. But starting around 1999, a fringe group of SBS skeptics began growing into a powerful reform movement. The Woodward case brought additional attention to the issue, inviting new research into the legitimacy of SBS. Today, as reflected in the Edmunds case, there are significant doubts about both the diagnosis of SBS and how it's being used in court.
In a compelling article published this month in the Washington University Law Review, DePaul University law professor Deborah Teurkheimer argues that the medical research has now shifted to the point where U.S. courts must conduct a major review of most SBS cases from the last 20 years. The problem, Teurkheimer explains, is that the presence of three symptoms in an infant victim—bleeding at the back of the eye, bleeding in the protective area of the brain, and brain swelling—have led doctors and child protective workers to immediately reach a conclusion of SBS. These symptoms have long been considered pathognomic, or exclusive, to SBS.

If you're really interested, you can dig up some ideas about alternate causes of SBS at this blog.

Mattel Exempted Itself from Lead Testing

Via Purple Pawn: The LA Times reported late last month that Mattel had lobbied itself out of third-party lead testing of its products.

"It's really ironic that the company that was a principal source of the problem" is now getting favorable treatment from the government, said Michael Green, executive director of the Center for Environmental Health in Oakland.
Mattel is getting a competitive advantage, Green said, because smaller companies must pay independent labs to do the tests. Testing costs can run from several hundred dollars to many thousands.

Medical Isotope Shortage

Via Orthoprax: the Journal of the American Medical Association reports on the ongoing "critical" shortage of medical isotopes (^99mTc) due to a reactor shutdown in Canada.

The shortage was expected to be exacerbated by the temporary closing of the Netherlands reactor for a month-long maintenance inspection from July 18 to August 18. Because the isotopes have a relatively short half life, they cannot be stockpiled.
Canadian authorities said they were working with medical isotope distributors and others to maximize the use of existing isotope supplies and with other international producers to increase isotope production and to coordinate shutdowns and other operations.

Since the journal article was written, the reopening of the Ontario reactor has been pushed into 2010, causing some trouble for the company that sells the isotopes, the Canwest news service reports:

Life sciences company MDS Inc. said Wednesday it has agreed to sell its analytical technologies division to Danaher Corp. for $650 million in cash and is also looking to unload its pharma business.
The Mississauga, Ont.-based company cited the recession and the prolonged shutdown of the National Research Universal reactor in Chalk River, Ont., as its reasons for the sales, which will allow MDS to focus on its isotope business, MDS Nordion.
Stephen DeFalco, chief executive at MDS, said the company still expects the reactor to restart in spring 2010.

A Cure for MS?

Via a mailing list: Science Daily reports that multiple sclerosis has been reversed in mice.

The new treatment, appropriately named GIFT15, puts MS into remission by suppressing the immune response. This means it might also be effective against other autoimmune disorders like Crohn's disease, lupus and arthritis, the researchers said, and could theoretically also control immune responses in organ transplant patients. Moreover, unlike earlier immune-supppressing therapies which rely on chemical pharamaceuticals, this approach is a personalized form of cellular therapy which utilizes the body's own cells to suppress immunity in a much more targeted way.
GIFT15 was discovered by a team led by Dr. Jacques Galipeau of the JGH Lady Davis Institute and McGill's Faculty of Medicine. The results were published August 9 in the prestigious journal Nature Medicine.
GIFT15 is composed of two proteins, GSM-CSF and interleukin-15, fused together artificially in the lab. Under normal circumstances, the individual proteins usually act to stimulate the immune system, but in their fused form, the equation reverses itself.

A caveat: this appears to be an early-stage treatment that may not reverse existing damage to the nerves.

Not Your Grandfather's Influenza After All

Via ProMED: News1130 reports that swine flu may not be coming back in a more virulent form in the fall, because the Spanish Flu may not have done so.

Virologist Dr. Jeffery Taubenberger, along with co-author and medical historian Dr. David Morens, argues there is no firm evidence that the 1918 virus ratchetted up in virulence in a fall wave - because there is no solid proof outbreaks of illness in the U.S. in the spring of 1918 were caused by the same virus.
Their commentary, published in this week's issue of the Journal of the American Medical Association, suggested changes in virulence or transmissibility of the current pandemic virus are not inevitable. In fact, they wrote, there are reasons to hope for "a more indolent pandemic course and fewer deaths" than seen in many previous pandemics.

Superbug Enzyme in Britain

Via an unnamed source: the BBC reports on a new "superbug" in the UK, a shared antibiotic-eating enzyme imported from India.

The enzyme, called New Delhi Metallo-1, has so far been found attached to bacteria that has caused urinary tract infections and respiratory infections.
It is of particular concern because it can jump from one strain of bacteria to another meaning it could attach itself to more dangerous infections that can cause severe illnesses and blood poisoning making them almost impossible to treat.
The NDM-1 enzyme destroys a group of antibiotics called carbapenems which are mainly used in Britain for severe infections and are tightly controlled because they are one of the few groups of antibiotics that remain useful against bacteria that have already developed resistance to the commonly used drugs.