now or later?
Would you rather have $20 now, or $40 next week? That’s a question Washington University School of Medicine researchers have been asking as part of an inquiry into the genetic component of the preference for instant reward. “Every day we make decisions about obtaining immediate gains, which come at the cost of delayed but larger advantages,” says Andrey Anokhin, Ph.D., associate professor of psychiatry. By studying adolescent twins and using mathematical formulas, Anokhin’s lab has identified genes that he says appear to be involved in that preference. The work is significant, he says, because of the possible connections between this sort of decision-making and binge drinking, drug use and nicotine dependence.

vaccine leader
A vaccine to prevent dengue fever discovered by a Saint Louis University researcher has been approved for use in Mexico. According to the World Health Organization, about half the world is at risk of developing this virus, which is spread by mosquitoes primarily in tropical and sub-tropical regions. Dr. Thomas Chambers, then associate professor of molecular microbiology and immunology, developed the vaccine in 1997. There are believed to be 390 million cases of dengue infections in the world each year. Symptoms are similar to those of influenza and can be deadly. While Mexico is the first country to approve the vaccine, other countries are reviewing it. Biopharmaceutical company Sanofi Pasteur has produced the first doses and expects to manufacture 100 million doses a year.

smoking decrease in china
Although nearly one-third of the world’s smokers live in China and two-thirds of Chinese men become daily smokers before age 25, Saint Louis University research is showing that there may be an overall decline in smoking by male teens. “Even though the smoking rate remains high in China, over the last 25 years, the rate of adolescent males starting to smoke has lessened by 1 percent a year,” says Jin Huang, Ph.D., assistant professor of social work at SLU’s College for Public Health and Social Justice. Huang and his team studied 2,400 males between ages 15 and 20 from four different kinds of neighborhoods—from rural communities to highly populated cities—and discovered that the most marked decrease was in urban areas. “Teens in more socially and economically developed communities may have better knowledge of and access to health care,” Huang says.

amino acids for growth
A team of researchers from Washington University School of Medicine has found that insufficient intake of essential amino acids and the nutrient choline is linked to stunted growth. “Stunting affects half the children in rural Africa and millions more elsewhere in the world,” says Dr. Mark. J. Manary, the Helene B. Roberson Professor of Pediatrics, who led the study. Manary and his team partnered with Johns Hopkins University, evaluating blood samples of 313 children, 12 to 59 months, from rural Malawi, and found that 64 percent of them were stunted, based on WHO growth curves. Eighty percent of these children were found to have low levels of all nine essential amino acids. Manary, who spends several months a year in Africa treating malnourished children, says the goal is to find a means—by way of a food product or additive—to reduce the condition. The findings are published in an online issue of EbioMedicine.