Tuesday, December 8, 2009

Wednesday, September 23, 2009

New killer virus found in Africa

Scientists discover disease that causes Ebola-like bleeding

Scientists have identified a lethal new virus in Africa that causes bleeding like the dreaded Ebola virus.

The so-called "Lujo" virus infected five people in Zambia and South Africa last fall. Four of them died, but a fifth survived, perhaps helped by a medicine recommended by the scientists.

It's not clear how the first person became infected, but the bug comes from a family of viruses found in rodents, said Dr. Ian Lipkin, a Columbia University epidemiologist involved in the discovery.

"This one is really, really aggressive," he said of the virus.

A paper on the virus by Lipkin and his collaborators was published online Thursday on in PLoS Pathogens.

The outbreak started in September, when a female travel agent who lives on the outskirts of Lusaka, Zambia, became ill with a fever-like illness that quickly grew much worse.

She was airlifted to Johannesburg, South Africa, where she died.

A paramedic in Lusaka who treated her also became sick, was transported to Johannesburg and died. The three others infected were health care workers in Johannesburg.

Investigators believe the virus spread from person to person through contact with infected body fluids.

"It's not a kind of virus like the flu that can spread widely," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which helped fund the research.

The name given to the virus — "Lujo" — stems from Lusaka and Johannesburg, the cities where it was first identified.

Investigators in Africa thought the illness might be Ebola, because some of the patients had bleeding in the gums and around needle injection sites, said Stuart Nichol, chief of the molecular biology lab in the CDC's Special Pathogens Branch. Other symptoms include include fever, shock, coma and organ failure.

Samples of blood and liver from the victims were sent to the United States, where they were tested at Columbia University in New York and at CDC in Atlanta. Tests determined it belonged to the arenavirus family, and that it is distantly related to Lassa fever, another disease found in Africa.

The drug ribavirin, which is given to Lassa victims, was given to the fifth Lujo virus patient — a Johannesburg nurse. It's not clear if the medicine made a difference or if she just had a milder case of the disease, but she fully recovered, Nichol said.

The research is a startling example of how quickly scientists can now identify new viruses, Fauci said. Using genetic sequencing techniques, the virus was identified in a matter of a few days — a process that used to take weeks or longer.

Along with Fauci's institute, the National Heart, Lung, and Blood Institute and Google also helped fund the research.

Aspirin cuts death risk for colon cancer patients

Score another win for the humble aspirin. A study suggests colon cancer patients who took the dirt-cheap wonder drug reduced their risk of death from the disease by nearly 30 percent.

Aspirin already is recommended for preventing heart attacks and strokes, along with its traditional use for relief of minor aches and pains. Its merit in colon cancer prevention has been tempered by its side effects, bleeding from irritation of the stomach or intestines.

The new study suggests patients who already have colon cancer may benefit from taking aspirin along with surgery and chemotherapy. In a separate analysis of a subgroup of patients, only those with the most common type of tumor, those that overproduce the Cox-2 enzyme, saw a benefit.

“The paper is absolutely incredible, and I don’t gush normally,” said Dr. Alfred Neugut of Columbia University Medical Center in New York who has done similar research but was not involved in the new study. In an accompanying editorial, Neugut wrote that the study “comes as close as it can to offering patients a way to help themselves.”

“This is certainly something patients would want to discuss with their doctors,” said Dr. Andrew Chan of Harvard Medical School in Boston, who led the study, which appears in Wednesday’s Journal of the American Medical Association.

It’s too early for an across-the-board recommendation however, both Chan and Neugut said. The results should be confirmed in an experiment where patients would be randomly assigned to take aspirin or a dummy pill. A study based in Singapore that’s now recruiting patients may verify aspirin’s benefit.

Chan’s study was observational, meaning researchers merely observed what patients were already doing, such as taking aspirin regularly for headaches. It’s possible that factors other than aspirin accounted for the difference in cancer deaths.

Colorectal cancer is the second leading cause of cancer death in the United States after lung cancer. The National Cancer Institute estimates that nearly 50,000 Americans will die from it this year.

The researchers analyzed data from two large ongoing studies, the Nurses’ Health Study and the Health Professionals Follow-up Study.

They looked at nearly 1,300 people with colorectal cancer who’d been followed for an average of 12 years. All the patients in the study had surgery for colon cancer and many also had chemotherapy.

Among the 549 participants who used aspirin regularly after their diagnosis, 81 died from colorectal cancer (about 15 percent). In contrast, among the 730 people who didn’t use aspirin, 141 died of the disease (about 19 percent).

Heat can help chemotherapy work better

Cancer patients whose tumors are targeted with heat treatment as well as chemotherapy are more likely to stay alive and cancer-free for longer than those who receive only chemotherapy, researchers said on Tuesday.

The finding suggests it may be possible to cut the dose of chemotherapy drugs by using heat, although more research is needed to establish this, they said.

German researchers looking at cancers in soft tissues such as muscle, fat and tissue around the joints, found that heat treatment more than doubled the proportion of patients whose tumors responded to chemotherapy.

mportantly, the process did not increase the harmful effects of chemotherapy treatment.

"We expect our findings will encourage other researchers to test the approach in other locally advanced cancers," said Rolf Issels, a professor of medical oncology at the University of Munich in Germany.

"Targeted heat therapy has already shown promise in recurrent breast and locally advanced cervical cancer in combination with radiation, and studies combining it with chemotherapy in other localized tumors such as those in the pancreas and rectum are ongoing."

Heat therapy for cancer involves a technique known as regional hyperthermia, which uses focused electromagnetic energy to warm the tissue in and around the tumor to between 40 and 43 degrees Celsius (104 to 109.4 degrees Fahrenheit).

The heat not only kills cancer cells, but also seems to make chemotherapy work better by making cancer cells more sensitive, Issels said. It also improves blood flow, allowing chemotherapy to be more effective.

Issels said his findings, presented at the ECCO-ESMO European cancer congress in Berlin, showed that soft tissue sarcoma patients receiving the targeted heat therapy plus chemotherapy "fared better on all outcome measurements."

"Almost three years after starting treatment, they were 42 percent less likely to experience a recurrence of their cancer at the same site or to die than those who were getting chemotherapy alone," he said.

The average length of time that patients remained disease free was 32 months in the group that got both treatments, compared with 18 months in the group that got chemotherapy alone — an improvement of 30 percent.

Issels said the equipment and specialist knowledge to be able to offer such heat therapies is only currently available in a handful of clinics and hospitals in Germany, the Netherlands, Switzerland, Norway and the United States.

But he urged cancer doctors to take note.

"The clear results of this trial show that the field has now matured to the point where we must step up efforts to explore its potential to offer an entirely new way of treating locally advanced disease in several major cancers," he said.

Saturday, July 11, 2009

Men of Honor - Twelve steps to honor

Men of Honor - Twelve steps to honor

Thursday, April 2, 2009

Friday, February 27, 2009

Anthrax investigation still yielding findings

Chemical composition of spores doesn't match suspect flask.

The deadly bacterial spores mailed to victims in the US anthrax attacks, scientists say, share a chemical 'fingerprint' that is not found in bacteria from the flask linked to Bruce Ivins, the biodefence researcher implicated in the crime.

The Federal Bureau of Investigation (FBI) alleges that Ivins, who committed suicide last July, was the person responsible for mailing letters laden with Bacillus anthracis to news media and congressional offices in 2001, killing five people and sickening 17. The FBI used genetic analyses to trace the mailed spores back to a flask called RMR-1029, which Ivins could access in his laboratory at the US Army Medical Research Institute of Infectious Diseases (USAMRIID) in Fort Detrick, Maryland.

Investigators used genetic analyses to track down the particular strain of Bacillus anthracis used in the attacks.Investigators used genetic analyses to track down the particular strain of Bacillus anthracis used in the attacks.

At a biodefence meeting on 24 February, Joseph Michael, a materials scientist at Sandia National Laboratories in Albuquerque, New Mexico, presented analyses of three letters sent to the New York Post and to the offices of Senators Tom Daschle and Patrick Leahy. Spores from two of those show a distinct chemical signature that includes silicon, oxygen, iron, and tin; the third letter had silicon, oxygen, iron and possibly also tin, says Michael. Bacteria from Ivins' RMR-1029 flask did not contain any of those four elements.

Two cultures of the same anthrax strain grown using similar processes — one from Ivins' lab, the other from a US Army facility in Utah — showed the silicon-oxygen signature but did not contain tin or iron. Michael presented the analyses at the American Society for Microbiology's Biodefense and Emerging Diseases Research Meeting in Baltimore, Maryland.

The chemical mismatch doesn't necessarily mean that deadly spores used in the attacks did not originate from Ivins' RMR-1029 flask, says Jason Bannan, a microbiologist and forensic examiner at the FBI's Chemical Biological Sciences Unit in Quantico, Virginia. The RMR-1029 culture was created in 1997, and the mailed spores could have been taken out of that flask and grown under different conditions, resulting in varying chemical contents. "It doesn't surprise me that it would be different," he says.

The data suggest that spores for the three letters were grown using the same process, says Michael. It is not clear how tin and iron made their way into the culture, he says. Bannan suggests that the growth medium may have contained iron and tin may have come from a water source.

Hard to tell apart

The meeting offered scientists who collaborated with the FBI during the investigation an opportunity to share detailed data. The analyses will eventually be published in peer-reviewed journals, the FBI has said.

Jacques Ravel, a genomics scientist at the University of Maryland School of Medicine in Baltimore, described his team's efforts to find genetic differences between various cultures of the Ames strain, the B. anthracis strain identified in the anthrax letters. At first, the team was surprised to find that the DNA sequences of a reference Ames strain and Ames samples from the investigation, such as bacteria isolated from the spinal fluid of the first victim, were exactly the same. "It was kind of a shock," says Ravel.

For help, the researchers turned to variants found by a team at USAMRIID. Patricia Worsham and her colleagues had noticed differences in shape, colour and rate of spore formation even within a single anthrax culture. Ravel's team identified the genetic mutations associated with four variants and developed an assay for one of them, called Morph E. Researchers at Commonwealth Biotechnologies in Richmond, Virginia, and the Midwest Research Institute's Florida Division in Palm Bay created assays for three other variants.

The FBI then used that arsenal of tests to pin down the origins of the anthrax letters, matching the mix of genetic variants in the mailed spores to Ivins' RMR-1029 flask. "It has the genetic signatures that identify it as the most likely source of the growth," says Bannan.

Ravel also sequenced the genome of a Bacillus subtilis strain that was found in one of the letters. That sample did not match a B. subtilis strain found in Ivins' lab, says Bannan, but the bacterial contamination still could have come from somewhere else in Ivins' institution.

The FBI has asked the National Academy of Sciences (NAS) to convene an independent panel of experts to review the anthrax investigation data. The academy is still in the process of drawing up a contract with the FBI that lays out an agreement to perform the study, says NAS spokeswoman Christine Stencel.

Thomas DeGonia, Ivins' lawyer at Venable LLP in Rockville, Maryland, maintains Ivins' innocence.

Thursday, January 8, 2009

Scientists reverse brain birth defects in animal models

Prof Joseph Yanai and his associates at the Hebrew University were able to overcome neural and behavioral birth defects in mice by using mouse embryonic neural stem cells. These cells migrate in the brain, search for the deficiency that caused the defect, and then differentiate into becoming the cells needed to repair the damage.

Neural and behavioral birth defects, such as learning disabilities, are said to be particularly difficult to treat, compared to defects with known cause factors such as Parkinson’s or Alzheimer’s disease, because the prenatal teratogen — the substances that cause the abnormalities — act diffusely in the fetal brain, resulting in multiple defects.

In the animal model, researchers were able to reverse learning deficits in the offspring of pregnant mice who were exposed to organophosphate (a pesticide) and heroin. This was done by direct neural stem cell transplantation into the brains of the offspring. According to the scientists, the recovery was almost 100 percent, as proved in behavioral tests in which the treated animals improved to normal behavior and learning scores after the transplantation. On the molecular level, brain chemistry of the treated animals was also restored to normal.

However, the researchers have also discovered that the neural stem cells succeed before they die in inducing the host brain itself to produce large number of stem cells, which repair the damage. This discovery was published earlier this year in one of the leading journals in the field, Molecular Psychiatry.

The scientists are now in the midst of developing procedures for the least invasive method for administering the neural stem cells, which is probably via blood vessels, thus making the therapy practical and clinically feasible.

The research on the project was supported by the US National Institutes of Health, the US-Israel Bi-national Science Foundation and the Israel anti-drug authorities.