Health Highlights: Feb. 4, 2008
Schizophrenia Drug Can Cause 'Profound' Sedation: FDA Genetically Modified Mice Can Catch a Cold Circumcision Doesn't Protect Females From HIV Infection: Study Bird Flu Continues to Spread in Bangladesh Method Found to Block Parasitic Spread of Malaria in the Body Diabetes-Linked Gene Variant Hikes Premature Birth Risk
Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Schizophrenia Drug Can Cause 'Profound' Sedation: FDA
Clinical studies showed that the long-acting, injectable form of the drug Zyprexa was effective at treating schizophrenia, but it caused "profound sedation" in some patients, according to information posted on the U.S. Food and Drug Administration Web site Monday.
The studies showed that this profound sedation occurred in 24 out of 1,915 patients who received the drug and lasted about one to three hours, according to a memo written by Thomas P. Laughren, the FDA's psychiatry products division director, Dow Jones reported.
The sedation caused by the long-acting form of Zyprexa appears unique to the injectable form of the drug. It's likely caused by the rapid release of the drug into the body after injection, the agency said.
An FDA panel of experts is scheduled to meet Wednesday to decide whether the long-acting, injectable form of Zyprexa, made by Eli Lilly & Co, has been shown to be an "acceptably safe" and effective treatment for schizophrenia.
Lilly has applied to the FDA for approval of long-acting Zyprexa, which could be injected every two to four weeks by a doctor, for the treatment of schizophrenia, Dow Jones reported. Currently, Zyprexa has FDA approval as an oral, once-daily medication to treat schizophrenia and bipolar disorder. A short-acting, injectable form of the drug is used to treat agitated, non-cooperative patients with schizophrenia or bipolar mania.
At its meeting, the FDA panel will also decide whether long-acting Zyprexa should carry a "black box" warning if it's approved, or if the FDA should consider approving it as a second line of treatment after other therapies fail to help patients, Dow Jones reported.
Genetically Modified Mice Can Catch a Cold
British scientists have created genetically modified mice that can catch the common cold -- an achievement that may help efforts to find new ways to treat asthma and other respiratory conditions such as chronic obstructive pulmonary disorder (COPD), BBC News reported.
Until now, it wasn't possible to infect small lab animals with the rhinoviruses that cause colds and can trigger asthma attacks in humans.
"These mouse models should provide a major boost to research efforts to develop new treatments for the common cold, as well as for more potentially fatal illnesses such as acute attacks of asthma and of COPD," said lead researcher Professor Sebastian Johnston of London's Imperial College, BBC News reported.
Of the 100 known rhinovirus strains, 90 percent infect humans by latching on to a specific receptor molecule on the surface of cells. These rhinoviruses can't do this in normal mice, so the British scientists modified the mouse receptor molecule to make it more like the human version.
The research appears in the journal Nature Medicine.
Circumcision Doesn't Protect Females From HIV Infection: Study
A new study challenges previous research that suggested that male circumcision helps protect women against infection by HIV, the virus that causes AIDS.
The new study concluded that male circumcision did not protect female sex partners from HIV infection and actually increased the risk of infection if the man resumed sex before the circumcision wound healed, which usually takes about a month, The New York Times reported.
The study, conducted by American and Ugandan researchers, did confirm that male circumcision reduced the risk of herpes and other genital ulcers among men. The findings were presented Sunday at the 15th Conference on Retroviruses and Opportunistic Infections in Boston.
The researchers said even though their findings about circumcision and risk of HIV infection did not reach statistical significance, they highlight the need to improve education of men who undergo circumcision and their female partners.
Bird Flu Continues to Spread in Bangladesh
A severe outbreak of H5N1 bird flu in Bangladesh continues to spread, and the country's livestock department says the virus is now present in 35 of 64 districts, Agence France-Presse reported.
No human infections have been reported in the country since the outbreak began in poultry last month, but about 800 farmers have received anti-viral drugs as a precaution. Major hospitals have been ordered to set up isolation units and several people have been confined to their homes.
As part of the effort to control the outbreak, nearly 50,000 poultry were slaughtered Sunday on farms near the capital of Dhaka, and an official said culling would continue Monday, AFP reported.
"The situation is not good. There is no sign of improvement," said livestock department scientific officer Biddyut Kumar Das.
In India, the H5N1 virus has spread to 13 of 19 districts in West Bengal state, which borders Bangladesh. Three poultry-culling workers in West Bengal were put in isolation after they developed flu-like symptoms.
Method Found to Block Spread of Malaria in the Body
While malaria isn't a scourge in the United States, the devastation it causes in other parts of the world -- especially Africa and Asia -- has always been a challenge for scientists, and finding a cure still remains elusive.
The parasitic infection attacks an estimated 500 million people worldwide every year with an estimated 1 million deaths, according to the World Health Organization.
Now, researchers from the Stanford University School of Medicine say they've been able to identify two enzymes that help the malaria parasites spread throughout the body. And they say they've also identified compounds that may be able to block those enzymes.
By blocking the enzymes, lead researcher Matthew Bogyo said in a university news release, the parasites stay in blood cells and die before they can escape and spread the malarial infection.
The research, published Feb. 3 in the advance online issue of Nature Chemical Biology, centered on enzymes in the parasite called proteases, according to the news release. By blocking the protease enzymes, the malarial parasites -- entering the body from mosquito bites -- can't be released, said Bogyo, an assistant professor of pathology.
"But no one really knew which proteases were responsible," Bogyo said. "The bottom line is that to combat malaria effectively, we are going to have to keep launching multiple classes of new drugs with different mechanisms of action if we want to prevent resistance."
Diabetes-Linked Gene Variant Hikes Premature Birth Risk
A gene associated with heightened type 2 diabetes risk has been linked to premature birth and low birth-weight among Hispanic women, according to Yale University School of Medicine researchers.
The scientists discovered that a variant of the ENPP1 gene, found in the DNA of women who had full term deliveries and another group of Hispanic women whose babies were born prematurely, was associated with increased risk of premature birth in the Hispanic study group.
ENPP1 has been associated with insulin resistance, glucose intolerance and a risk of developing type 2 diabetes. Insofar as low birth-weight and pre-term delivery are concerned, the Yale researchers theorized that the gene variant is associated with deranged energy metabolism, according to a university news release. Deranged energy metabolism causes some energy-producing substances in the body to be replaced by other substances not always associated with creating body energy.
The initial results seem to indicate that ENPP1 can be used as a predictor in other ethnic groups as well. "In our original study, 85 percent of the population was Hispanic," said Dr. Errol Norwitz, associate professor at the university's department of obstetrics, gynecology and reproductive sciences.
"It appears that there are genetic variations unique to each ethnic population," he said in the news release. "We are now in the process of validating our findings in African-American, Caucasian and Native-American populations."
The study was presented during the Feb. 2 annual meeting of the Society for Maternal Fetal Medicine, in Dallas.