Findings

Science  01 Jul 2011:
Vol. 333, Issue 6038, pp. 20
  1. Buying Time for Snake Bite Victims

    Time is of the essence for people bitten by a poisonous snake. Now, researchers have identified an ointment that might give victims of bites from snakes such as cobras a bit more time to reach a hospital or clinic.

    The bulky proteins in some snake venoms don't infiltrate the bloodstream immediately but wend through the lymphatic system to the heart. So physiologist Dirk van Helden of the University of Newcastle in Australia and colleagues went looking for a chemical that might detain the venom. They focused on an ointment for a painful condition called anal fissures that contains nitroglycerin. It releases nitric oxide, causing the lymphatic vessels to clench.

    The researchers injected volunteers in the foot with a harmless radioactive mixture that moves through the lymphatic vessels. In control subjects, the mixture took 13 minutes to reach the top of the leg, but required 54 minutes if the researchers immediately smeared the ointment around the injection site, the team reports online this week in Nature Medicine. The researchers then injected the feet of anesthetized rats with venom from the eastern brown snake, one of Australia's deadliest; animals whose limbs were smeared with the cream survived about 50% longer than those left untreated.

    CREDIT: ISTOCKPHOTO.COM

    The ointment could prove valuable for treating bites from snakes such as cobras, mambas, and kraits that produce neurotoxic venom. But it's unlikely to be effective against bites from U.S. snakes such as rattle-snakes, copperheads, and cottonmouths, which inject a different type of venom.

    http://scim.ag/snake_bite

  2. Deciphering Ovarian Cancer

    A massive effort to catalog genetic errors in ovarian cancer has found many known cancer genes along with surprising genomic disorders.

    The study explored the genetic under-pinnings of serous ovarian adenocarcinoma, an aggressive cancer that kills 9700 women in the United States each year. Fifteen teams analyzed nearly 500 patients' tumors for genetic aberrations and sequenced the gene-coding DNA of 316 of the samples. Nearly all had mutations in P53, a tumor suppressor gene, and some had mutations in other cancer genes. The study also found “enormous structural variation,” including extra copies of many genes, says project leader Paul Spellman of the Lawrence Berkeley National Laboratory in California. Half of the samples had flaws in the cell's machinery for repairing DNA, suggesting these tumors could be treated with certain drugs.

    The study, published this week in Nature, is the second cancer completed by The Cancer Genome Atlas, a $375-million-and-counting project launched by the National Institutes of Health in 2006 that is sequencing more than 20 cancer types.

    http://scim.ag/cancer_ovarian

  3. The Mental Hazards of City Living

    CREDIT: FOTOSEARCH

    You can take the person out of the city, but perhaps you really can't take the city out of the person. City dwellers tend to have higher rates of mental health problems such as schizophrenia, depression, and anxiety disorders than people in rural areas. To understand how city living could predispose people to mental illness, psychiatrist Andreas Meyer-Lindenberg and collaborators at the Central Institute of Mental Health and the University of Heidelberg Medical Faculty in Germany, used functional magnetic resonance imaging (fMRI) on 32 healthy adults from cities, towns, and rural areas. As the subjects solved arithmetic problems, the researchers created social stress by criticizing their performance.

    The fMRI scans revealed two differences in how the brains of urban and rural inhabitants respond to social stress: Current city dwellers showed higher activity in the amygdala, which evaluates social threats and tends to be overactive in people with anxiety disorders. But people who'd been raised in a city, regardless of their current home, showed more activation in the perigenual anterior cingulate cortex (pACC), another region involved in emotion and social processing and implicated in some studies of schizophrenia. Thus, the pACC may be susceptible to lasting effects from one's environment early in life, whereas the amygdala is more sensitive to one's current situation, the team hypothesizes in Nature.

  4. Sleeping Sickness Drug Shows Promise

    African sleeping sickness is one of the most neglected of the neglected diseases. Now, researchers have designed a compound that kills sleeping sickness parasites in the blood and the brain. After promising studies in rodents, the compound will enter human safety trials later this year.

    Human African trypanosomiasis, the formal name for the disease, sickens an estimated 30,000 people per year. Injected by the bite of the tsetse fly, the parasites that cause the illness first dwell in the blood and then infiltrate the brain. Treatment can be dangerous and complicated. The drug main-stay kills 1 in 20 people who take it. A newer medicine is less toxic but requires an elaborate treatment regimen.

    The new drug candidate emerged from a joint effort between the biotech firm SCYNEXIS of Research Triangle Park, North Carolina, and Anacor Pharmaceuticals of Palo Alto, California. Sponsoring the project was the Drugs for Neglected Diseases initiative (DDNi), a nonprofit organization based in Geneva, Switzerland. The compound, which can be taken orally, cures mice even if the parasites have entered the brain, researchers reported this week in PLoS Neglected Tropical Diseases. If the drug pans out in further trials, “it will be the first new, orally available treatment for sleeping sickness in the past 30 years,” says medicinal chemist Robert Jacobs of SCYNEXIS. http://scim.ag/sleep_sickness

  5. Young Monkeys Don't Pardon the Interruption

    CREDIT: HELENE BOUCHET

    It can take some parental nagging before human children learn not to interrupt—and monkeys are no different, new research shows. The core of communication in Campbell's monkeys (Cercopithecus campbelli), which are native to western Africa, revolves around alternating vocal calls. Researchers recorded spontaneous utterances of both young and adult monkeys and tallied how often each broke the rules of alternating calls. The adults broke the rules, calling twice in a row instead of letting another monkey take its turn, less than 1% of the time. The juveniles, however, were rule-breakers in 13% of their calls.

    Moreover, when played calls that either followed conversational rules or didn't, adults paid closer attention to alternating conversations, whereas juveniles didn't seem to differentiate. The findings, which appear 23 June in Scientific Reports, could help scientists learn more about how language evolved in humans—as long no one cuts anyone else off. http://scim.ag/_interruption

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