LUBBOCK, Texas - A slice of cool, fresh watermelon is a juicy way to top off a Fourth of July cookout and one that researchers say has effects similar to Viagra — but don't necessarily expect it to keep the fireworks all night long.

Watermelons contain an ingredient called citrulline that can trigger production of a compound that helps relax the body's blood vessels, similar to what happens when a man takes Viagra, said scientists in Texas, one of the nation's top producers of the seedless variety.

THURSDAY, June 26 (HealthDay News) -- The latest data on HIV infection across 33 states finds new diagnoses jumping by 12 percent annually between 2001 and 2006 among young gay and bisexual men.

Researchers at the U.S. Centers for Disease Control and Prevention (CDC) say the rise is "especially concerning" for young black men aged 13 to 24 who have sex with men. For this group, the annual rate of new HIV diagnoses rose by 15 percent annually, compared to a 9 percent and an 8 percent annual rise among their white and Hispanic peers, respectively.

Unsafe sexual behavior continues to be a problem in New York City, says a health department report that found 11 percent of residents (about 610,000 adults) reported having more than one sex partner in the past year.

Men were much more likely than women to report multiple partners (17 percent vs. 6 percent), and young adults were four times more likely than older adults to report multiple partners, United Press International reported.

By Amanda Gardner
EmpowHer's HealthDay Reporter

MONDAY, June 16 (HealthDay News) - MRI and PET scan studies are showing remarkable similarities between the brains of gay men and straight women, and between those of lesbians and straight men.

For example, the brains of straight men and of gay women share certain common features: both are slightly asymmetric, with the right hemisphere larger than the left, say the Swedish researchers.

On the other hand, the brains of gay men and straight women are both symmetrical.

FRIDAY, June 13 (HealthDay News) -- Children who are frequent self-cutters are more likely to engage in risky sexual behavior, a new study says.

People who have cut themselves at least three times used condoms less often during sex, were more likely to share cutting instruments and had less self-restraint in general than teens who only cut themselves once or twice, according to the report in the June issue of the Journal of Developmental & Behavioral Pediatrics.