Sexual

Female sex hormones play a vital role in defense against sexually transmitted diseases

Two McMaster University studies, to be published in the Journal of Virology, show that sex hormones have a profound effect on susceptibility of female mice to the herpes simplex virus, type 2 (HSV-2 ), one of the most common sexually transmitted diseases. Charu Kaushic, assistant professor and supervisor of the studies, says the implication of this work is quite significant. "The research...

Sexual cooperation: Mating increases longevity in ant queens

The phenomenon of sexual conflict is a powerful driving force in the evolution of reproductive biology for many animal species. Males often try to manipulate their female mates during copulation--for example, by traumatic inseminations (as in the case of bed bugs) or by the transfer of toxic seminal fluids (as in the case of the fruitfly Drosophila). These manipulations are beneficial to males be...

New study: Sexually transmitted disease treatment can be effectively administered by sex partners

Effective control of sexually transmitted diseases (STDs) requires treatment of the sexual partners of infected patients. A new study shows that providing infected men with antibiotics to give their partners is more effective than traditional means of contacting and treating the partners, according to an article in the Sept. 1 issue of Clinical Infectious Diseases, now available online. Men with...

High rates of sexually transmitted infections found in young drug users

Researchers at the Johns Hopkins Bloomberg School of Public Health and other institutions found high rates of herpes simplex virus 2 and syphilis among young drug users in Baltimore, Md. The study found that women had significantly higher rates compared to their male counterparts, but did not find significant differences between injection drug users and non-injection drug users. Few of the infect...

Single gene is genetic switch for fly sexual behavior

A male fly's sexual courtship of a female fly is a complicated business of tapping, singing, wing vibration, and licking, but a single gene is all that is needed to produce this complex behavior, according to new research published in this week's issue of the journal Cell. The gene encodes the Fruitless protein. Male and female flies carry different versions of the fruitless protein, as a...

MUHC investigators search for the root of sexual pain in women

A multidisciplinary team consisting of researchers from McGill/MUHC and the CHUM have been awarded a grant of nearly $700,000 by the Canadian Institutes of Health Research (CIHR) to continue their groundbreaking research on pain suffered by some women during sexual intercourse. The new funding will allow the team, consisting of psychologists, gynecologists, physical therapists and statistician/ep...

Sexual reproduction delays aging in a mammalian species

Past research on aging and the life histories of diverse species has shown that sexual reproduction is biologically costly for individuals and tends to decrease lifespan rather than increase it. But a new study by Philip Dammann and Hynek Burda from the University of Duisburg-Essen shows that, in a vertebrate species, the opposite can be true as well. The authors, studying captive Zambian...

Face perception is modulated by sexual orientation

New research indicates that an area of the brain thought to act in reward circuitry may represent a phase in visual processing during which sexual orientation modulates how we perceive individual faces. The findings are reported by Felicitas Kranz and Alumit Ishai of the University of Zurich. Of all the visual skills possessed by humans, face recognition is arguably the most developed. Pa...

Teens unaware of sexually transmitted diseases until they catch one, Carnegie Mellon study finds

Most sexually active teenage girls know relatively little about sexually transmitted diseases (STDs) until it is too late, according to a paper by Carnegie Mellon University researchers that will be published in the January edition of the Journal of Adolescent Health. "For the most part kids learn about sexually transmitted diseases when they are getting diagnosed with them," said Julie Do...

Genetic tug of war determines sexual differentiation

Whether or not a fertilized mammalian egg ultimately develops into a male or female is determined by the winner of a tug of war between two different genes encoding signaling proteins and the divergent pathways they control, according to a new study led by Duke University Medical Center cell biologists. In their experiments in mice, the researchers found that two specific genes, Wnt4 and F...

Syphilis rate on rise in US gay, bisexual men

Armed with more than a decade’s worth of statistics, researchers are sounding a new alarm about growing rates of syphilis among gay and bisexual men. The overall number of syphilis cases in the United States fell from 50,578 in 1990 to just 7,177 in 2003 perhaps because of a nationwide prevention campaign aimed at heterosexuals. Nevertheless, gay men have seen their rates rise significantl...

New measure of sexual arousal found for both men and women

According to a new study published in the latest issue of The Journal of Sexual Medicine and conducted in the Department of Psychology of McGill University, thermography shows great promise as a diagnostic method of measuring sexual arousal. It is less intrusive than currently utilized methods, and is the only available test that requires no physical contact with participants. Thermography is cur...

1/3 of sexually active older adults with HIV/AIDs has unprotected sex

One out of three sexually active older adults infected with HIV has unprotected sex, according to a study by Ohio University researchers. A survey of 260 HIV-positive older adults found that of those having sex, most were male, took Viagra and were in a relationship. AIDs cases among the over-50 crowd reached 90,000 in 2003. According to the Centers for Disease Control and Prevention, they...

Scientists sequence genome of parasite responsible for common sexually transmitted infection

Researchers have decoded the genetic makeup of the parasite that causes trichomoniasis, one of the most common sexually transmitted infections (STIs), revealing potential clues as to why the parasite has become increasingly drug resistant and suggesting possible pathways for new treatments, diagnostics and a potential vaccine strategy. The genome sequencing project, funded by the National Institu...

Bisexual fruit flies show new role for neurochemical

Fruit flies' ability to discern one sex from another may depend on the number of receptors on the surface of nerve cells, and the number of receptors is controlled by levels of a ubiquitous brain chemical, University of Illinois at Chicago researchers have found. Everything from the ability to concentrate, perceive and learn to debilitating illnesses such as amyotrophic lateral sclerosis,...

Asexual worm quickly adapts to soil contamination

Soil contaminants lead to rapid genetic adaptations in the nematode Acrobeloides nanus. The worms from contaminated soil live longer and lay more eggs under polluted conditions than the worms from unpolluted soil. Dutch-sponsored researcher Agnieszka Doroszuk demonstrated this in her study into the long-term effects of environmental pollution on soil organisms. Environmental pollution is...