MONDAY, April 7 (HealthDay News) -- Anticipating a good laugh reduces the release of stress hormones that can weaken your immune system over time, according to a new study.

The researchers, who previously had found that the build-up for mirthful experience boosted health-protecting hormones, suggested that mirth may be a key to better physical and mental health.

"Our findings lead us to believe that by seeking out positive experiences that make us laugh, we can do a lot with our physiology to stay well," the study team's lead researcher, Lee Berk of Loma Linda University in California, said in a prepared statement. The study was scheduled to be presented Monday at the annual meeting of the American Physiological Society during the Experimental Biology 2008 scientific conference in San Diego.

In their earlier work, the researchers found that two "beneficial" hormones -- depression-alleviating beta-endorphins and immunity-boosting human growth hormone -- increased when volunteers anticipated watching a humorous video.

Using a similar protocol, this time they studied 16 healthy, fasting male volunteers assigned to either a control group or a group told to anticipate a humorous event. Blood draws from both groups were taken before the event (anticipation), during the event and afterward, then analyzed for three hormones associated with stress. Chronically released high-stress hormone levels can weaken the immune system.

The levels of the stress hormones cortisol, epinephrine (also known as adrenaline) and dopac -- a brain chemical that helps produce epinephrine -- fell by 38 percent to 70 percent during the anticipation stage in the group told they would be having a humorous experience. A progressive pattern of decreased levels for the three hormones occurred throughout the event.

More information

The U.S. National Library of Medicine has more about managing stress.

MONDAY, April 7 (HealthDay News) -- Call it a case of gator aid. New research suggests that alligator blood could serve as the basis for new antibiotics targeting infections caused by ulcers, burns and even drug-resistant "superbugs."

The research is in its early stages -- extracts of alligator blood have only been tested in the laboratory -- and there's no guarantee that it will work in humans. Still, the findings are promising, researchers said.

"We need new antibiotics. Anything like this is a step forward," said Dr. Stuart Levy, a professor of medicine at Tufts University School of Medicine, who's an expert in antibiotic-resistant infections and is familiar with the new study. "But there are hurdles that this kind of antibiotic poses that others might not."

The study authors, from McNeese State University and Louisiana State University, said their research is the first to take an in-depth look at alligator blood's prospects as an antibiotic source. According to the researchers, alligators can automatically fight germs such as bacteria and viruses without having been exposed to them before launching a defense.

For the study, the researchers extracted proteins known as peptides from white cells in alligator blood. As in humans, white cells are part of the alligator's immune system. The researchers then exposed various types of bacteria to the protein extracts and watched to see what happened.

In laboratory tests, tiny amounts of these protein extracts killed a so-called "superbug" called methicillin-resistant Staphylococcus aureus, or MRSA. The bacteria has made headlines in recent years because of its killing power in hospitals and its spread among athletes and others outside of hospitals.

The extracts also killed six of eight strains of a fungus known as Candida albicans, which causes a condition known as thrush, and other diseases that can kill people with weakened immune systems.

The researchers, who presented their findings April6 at the national meeting of the American Chemical Society in New Orleans, said the blood extract could be used to develop an antibiotic in a topical cream form. They suggest that it could be called "alligacin."

Levy said the human body might reject alligator proteins, thinking they're foreign invaders. "Our bodies love to make antibodies to proteins," he said. "After you get the first dose, the body sees it as foreign, and the next dose gets scooped up by the immune system, and it's done."

But study lead author Lancia Darville, a doctoral student at Louisiana State University in Baton Rouge, La., said scientists might be able to create drugs that copy the blood proteins once they figure out their structure. The idea would be to make a chemical that the body doesn't think is a protein. Even so, Darville said, "it is not easy to mimic any antimicrobial peptide for clinical use."

Levy noted that many pharmaceutical companies have stopped investigating new antibiotics, because other areas of medicine are more profitable. The gap "has to be filled by more discovery," said Levy, who's also president of the Alliance for the Prudent Use of Antibiotics.

The study authors said alligator blood could become a drug source for humans within a decade.

Still, Emily Ackiss, a clinical epidemiologist at Scripps Mercy Hospital in Chula Vista, Calif., who's familiar with the study findings, said, "The research discussed in this article is basic research. More extensive research and experimentation are needed before drug development could be expected."

More information

Learn more about alligators from the University of Florida  .

FRIDAY, April 4 (HealthDay News) -- People like to temper their emotions to the task at hand, and it can help them succeed, even if the emotions are not pleasurable ones, a new report suggests.

Individuals are motivated to increase their level of anger, for example, when they expect to complete a confrontational task in which anger might enhance performance, according to the study published in the April issue of Psychological Science. And reaching that frame of mind does seem to help.

Psychologists from Boston College and Stanford University told study participants that they would either play a computer game that is confrontational (a first-person shooter game where killing enemies is the primary goal) or one that is not confrontational (a game in which players guide a waitress serving customers). Participants then rated the extent to which they would like to engage in different activities before playing the game.

Participants preferred activities that were likely to make them angry (e.g., listening to anger-inducing music, recalling past events in which they were angry) when they expected to perform the confrontational task, researchers found. In contrast, participants preferred more pleasant activities when they expected to perform a non-confrontational task.

Angry participants proceeded to perform better than others in the confrontational game of killing enemy soldiers. However, they did not perform better than others in the non-confrontational game of serving customers.

"Such findings," the authors wrote, "demonstrate that what people prefer to feel at any given moment may depend, in part, on what they might get out of it."

More information

The National Crime Prevention Council has more about how to manage your anger  .

THURSDAY, March 20 (HealthDay News) Sanitation pays: For every dollar spent installing toilets in developing countries, there would be a $9 return in productivity, health and other benefits, according to a UN report released today.

The UN Millennium Development Goal (MDG) for sanitation seeks to halve by 2015 the number of people worldwide who don't have access to a toilet. The estimated cost of the program is $38 billion, less than one percent of annual global military spending. But that $38 billion investment would yield $347 billion worth of net benefits, according to the UN.

For example, meeting the MDG target for sanitation would increase productivity and add 3.2 billion annual working days worldwide. Universal access to toilets around the world would add more than four times as many working days, the report found.

Currently, about 2.6 billion people (more than one-third of Earth's population) lack access to adequate sanitation. Every day, each of those people spends a total of about 30 minutes waiting in line to use a public toilet or seeking a secluded location to relieve themselves. Over one month, that adds up to the equivalent of two working days, the UN said.

The lack of adequate sanitation also leads to lost workdays due to diarrheal disease - either because workers themselves are sick or because they have to stay home to care for a sick child or relative. In addition, many women don't go to work when they're menstruating because their workplaces have no toilets.

Globally, about 200 million tons of human waste and millions of tons of wastewater are discharged uncontained and untreated into waterways every year. This exposes people to disease-causing bacteria, viruses and parasites, which cause diarrheal disease, parasitic infections, worm infestations, and the eye disease trachoma.

Diarrheal disease (including dysentery and cholera) is a leading cause of death (1.8 million a year) and illness. About 5,000 children die of diarrheal disease each day and hundreds of millions of other children suffer reduced growth physical growth and impaired cognitive function due to intestinal worms.

Together, poor hygiene and lack of access to sanitation contribute to 88 percent of all deaths from diarrheal disease, according to the UN.

Meeting the MDG sanitation target would save $552 million a year worldwide in disease treatment costs. Meeting the target would also boost children's school attendance and provide a number of economic benefits for communities, such as infrastructure development.

In addition, health, safety and comfort standards for sanitation (along with aesthetic considerations) can also have a major influence on tourists' choice of destinations, the UN noted.

Currently, the areas with the least access to improved sanitation are West and Central Africa (36 percent coverage), South Asia (37 percent), and Eastern and Southern Africa (38 percent). Of the 2.6 billion people who don't have access to improved sanitation, two billion (77 percent) live in rural areas.

More information

The World Health Organization has more about sanitation and health  .