It's legal, it's gaining popularity among teenagers and young adults and it's one of the most potent hallucinogens around.

Brain-imaging studies performed in animals at Brookhaven National Laboratory have provided researchers with clues about why this increasingly popular recreational drug that causes hallucinations and motor-function impairment in humans is abused. Using trace amounts of Salvia divinorum – also known as “salvia,” a Mexican mint plant that can be smoked in the form of dried leaves or serum – Brookhaven scientists found that the drug’s behavior in the brains of primates mimics the extremely fast and brief “high” observed in humans.

New heart research published inNature Genetics reveals how a gene called osteoglycin (Ogn), which had not previously been linked with heart function, plays a key role in regulating heart growth. The study suggests that the gene can behave abnormally in some people, and that this can lead to the heart becoming abnormally enlarged.

The researchers hope that through understanding how enlarged hearts are linked to the workings of genes like Ogn, they will be able to develop new treatments for the condition, which affects a large proportion of those with high blood pressure, obesity and diabetes.

Scientists believe that enlarged hearts are caused by a combination of genetic factors and external stimuli such as high blood pressure and obesity. However, the role played by genes has remained largely unknown.

Women who have used Fosamax are nearly twice as likely to develop the most common kind of chronically irregular heartbeat (atrial fibrillation) than are those who have never used it, according to research from Group Health and the University of Washington published in the April 28 Archives of Internal Medicine.

Merck markets Fosamax, the most widely used drug treatment for the bone-thinning disease osteoporosis, explained study leader Susan Heckbert, MD, PhD, MPH, a professor of epidemiology and scientific investigator in the Cardiovascular Health Research Unit at the University of Washington. The Food and Drug Administration (FDA) approved the first generic versions (called alendronate) in February.

A widely used class of diabetes medications appears to be associated with an increased risk for fractures, according to a report in the April 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

“The insulin-sensitizing thiazolidinediones are a relatively new and effective class of oral antidiabetic agents that have gained wide use in clinical conditions characterized by insulin resistance,” the authors write as background information in the article. Two drugs in this category, pioglitazone and rosiglitazone, account for 21 percent of oral diabetes medications prescribed in the United States and 5 percent of those in Europe. Recent studies have suggested that these therapies may have unfavorable effects on bone, resulting in slower bone formation and faster bone loss.

Young women who took the commonly used epilepsy drug phenytoin for one year showed significant bone loss compared to women taking other epilepsy drugs, according to a study published in the April 29, 2008, issue of Neurology®, the medical journal of the American Academy of Neurology.

Researchers tested the bone health of 93 women with epilepsy who were between the ages of 18 and 40 and were taking the epilepsy drugs phenytoin, carbamazepine, lamotrigine or valproate. Bone mineral density was measured at the spine and two areas of the hip, (the femoral neck and total hip) at the beginning of the study and one year later. Researchers also evaluated each woman’s nutrition and physical activity, along with other factors that affect bone health.

Are climate change and carbon emissions inextricably linked? New research published in Carbon Balance and Management suggests that this may not be the case, although it may be some time before we reach this saturation point.

The land and the oceans contain significantly more carbon than the atmosphere, and exchange carbon dioxide with the atmosphere. The amount of CO2 emissions absorbed by the land or the oceans vary in response to changes in climate (including natural variations such as El Nino or volcanic eruptions). So current theories suggest that climate change will have a feedback effect on the rate that atmospheric CO2 increases; rising CO2 levels in turn add to global warming.

The link between the carbon cycle, and human effects caused by emissions, energy use and agriculture, may only be relevant for the next 'several centuries,’ suggest Igor Mokhov and Alexey Eliseev from the A.M. Obukhov Institute of Atmospheric Physics RAS, in Moscow, Russia. The authors used a climate model known as IAP RAS CM to study how feedback between our climate and the carbon cycle changes over time. In their simulations, the authors assumed that fossil fuel emissions would grow exponentially with a characteristic timescale from 50 to 250years.