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Circumcision doesn’t reduce gay men’s HIV risk

Wed, 08 Oct 2008 04:53:00 -0400

There is insufficient evidence that circumcision reduces the risk of human immunodeficiency virus (HIV) infection or other sexually transmitted infections among men who have sex with men, according to an analysis of previous research.

Less is known about whether circumcision offers protection against HIV infection among men who have sex with men (MSM).

Therefore, Gregorio A. Millett, M.P.H., of the Centers for Disease Control and Prevention, Atlanta, and colleagues performed a meta-analysis of 15 studies to examine the association of circumcision status with HIV infection and other STIs among MSM.

The studies included a total of 53,567 MSM participants (52 percent of whom were circumcised).

The researchers found that the odds of being HIV-positive were nonsignificantly lower among MSM who were circumcised than uncircumcised.

On contrary, a statistically significant protective association of circumcision with HIV infection was found for MSM studies conducted prior to the introduction of highly active antiretroviral therapy (HAART) in 1996.

Of studies conducted after HAART, the association of circumcision and HIV infection was not statistically significant.

"A possible explanation for [these differences] may be related to an increase in the sexual risk behaviours of MSM after HAART. It has been well documented that beliefs that HAART limits HIV transmissibility are associated with increases in sexual risk behaviour among MSM, and that the era since the advent of HAART has been defined by higher rates of sexual risk behaviours among MSM, outbreaks of STIs, and increasing rates of HIV infection," the researchers said.

Among MSM who primarily engaged in insertive anal sex, the link between male circumcision and HIV was protective but not statistically significant.

The STI analyses similarly revealed no statistically significant association by circumcision status among MSM.

"Taken together, these findings indicate insufficient evidence among available observational studies conducted with MSM of an association between circumcision and HIV infection or other STIs," the researchers said.

"Additional studies are necessary to elucidate further the relationship between circumcision status and HIV infection or STIs among MSM," they added.

The study is published in the October 8 issue of JAMA. (ANI)

Anti-inflammatory drugs may be linked to reduced breast cancer risk

Wed, 08 Oct 2008 04:52:00 -0400

Regular use of Non Steroidal Anti-Inflammatory Drugs (NSAIDs) is associated with a 12 per cent relative risk reduction in breast cancer compared to non-users, according to a new research.

The finding is based on an analysis of data from 38 studies that enrolled more than 2.7 million women, the largest of its kind, by researchers at the University of British Columbia, Vancouver Coastal Health Research Institute, and the University of Santiago de Compostela.

A separate analysis for Aspirin showed a 13 per cent relative risk reduction in breast cancer and an analysis for Advil showed a 21 per cent relative risk reduction.

The review, conducted by Dr. Mahyar Etminan, assistant professor of medicine at the University of British Columbia, and member of the Vancouver Coastal Health Research Institute, and Bahi Takkouche, professor of epidemiology at the University of Santiago de Compostela in Spain, alludes to a protective affect against breast cancer.

Previous studies have shown conflicting results that support and fail to support the use of non-steroidal anti-inflammatory drugs (NSAIDs), including Aspirin and ibuprofen (Advil), in reducing the risk of developing breast cancer.

Etminan warns that since most of the data is from observational studies, the results should be considered as hypothesis generating.

"The results are encouraging and may help us better understand the importance of role of inflammation in the pathology of the disease," says Etminan, who is also a scientist at the Center for Clinical Epidemiology and Evaluation at VCHRI.

"However, we don''t recommend the routine use of NSAIDs for breast cancer prevention until large randomized trials confirm these findings. Results from an ongoing trial will be available in 2009," Etminan added.

The study is published in the U.S. Journal of the National Cancer Institute. (ANI)

Study to determine black cohosh’s safety for breast cancer patients

Wed, 08 Oct 2008 04:50:00 -0400

A researcher from the University of Missouri will conduct a study to determine how black cohosh - an herbal supplement often used to relieve hot flashes in menopausal women - interacts with tamoxifen, a common drug used to treat breast cancer.

The risk of developing breast cancer increases as women age and reach menopause. Many women who have, or are at risk, for breast cancer take tamoxifen.

The drug prevents approximately half of breast cancers in women who are likely to develop the disease. However, when women take tamoxifen, they cannot take hormone replacement therapies to relieve menopausal symptoms.

Their options are limited to taking antidepressants that can have complications, enduring uncomfortable menopausal symptoms, or trying the black cohosh.

“Hopefully, this study will provide evidence that black cohosh is safe to use for breast cancer patients. Currently, there is little reliable information guiding women in how they can use foods and botanical supplements to enhance their treatment or improve their quality of life,” said Rachel Ruhlen, a postdoctoral researcher in the MU School of Medicine.

In order to study how black cohosh and tamoxifen interact, Ruhlen will use a group of rats prone to breast cancer, known as ACI rats.

Previous studies have found that human breast cancer is associated with life-time exposure of estrogen.

ACI rats, like humans, develop mammary tumours after exposure to estrogen. In a previous study, Ruhlen found that when ACI rats were treated with the human breast cancer drug tamoxifen, mammary tumour mass was reduced by 89 percent.

“Many animal models of breast cancer differ in important ways from humans with breast cancer,” Ruhlen said.

“These models are useful in studying how human tumours grow and spread to other parts of the body, but fall short because of the difference in how human tumours begin.

“However, mammary tumours in ACI rats share several key features with the majority of human breast cancers, particularly in how tumours start. Because the ACI rats develop tumours and can be treated in a way similar to humans, it is a relevant model for human breast cancer,” Ruhlen added. (ANI)

Fertile women use squeaky voices to attract men

Wed, 08 Oct 2008 04:49:00 -0400

Women speak with a squeakier voice at the time of the month when they’re most fertile – making them more attractive to the men, scientists have found.

The finding implies that a high-pitched voice – not a husky one – may be the key to finding a perfect mate.

Previous research found men pick up on other, less subtle clues to a woman''s fertility, such as scent and flirtatious behaviour.

There is increasing evidence that women''s behaviour changes in subtle ways throughout the monthly cycle, and that men find women most attractive around the time of ovulation.

A study last year found that the earnings of lap dancers increased dramatically when they were most fertile.

In the latest study, America researchers followed 69 women for a month, using fertility tests to show when each was most and least likely to become pregnant. Voices were taped to discover the pitch and speed at which they talked.

The University of California team found that at the most fertile times of the month voice pitch rose, peaking in the two days before ovulation was due to take place.

The study has been published in the journal Biology Letters.

The study’s researcher Gregory Bryant, from the Department of Communication Studies, Center for Behaviour, Evolution and Culture, said the women sub-consciously added pitch when speaking to others.

“This raises the intriguing possibility that cues of ovulation appear during social interactions and could serve a communicative function,” the Daily Express quoted him, as saying. (ANI)

Newly created peptide turns cancer friend into foe

Wed, 08 Oct 2008 04:45:00 -0400

A team of American scientists has created a peptide that binds to Bcl-2, a protein that protects cancer cells from programmed cell death, and converts it into a cancer cell killer.

The progress made by scientists at Burnham Institute for Medical Research takes then a step closer to creating new cancer treatments.

The Bcl-2 protein has long been implicated in protecting cancer cells from apoptosis, the process that usually keeps cancer cells in check.

The researchers have revealed that the peptide called NuBCP-9, and its mirror-image molecule work on Bcl-2 like a molecular switch, converting it into a pro-apoptotic protein, and inducing cell death in cancer cells.

“Our results provide insight into Bcl-2 conversion and identify a new direction for Bcl-2-based drug leads and cancer drug development,” said Dr. Xiao-kun Zhang, who co-authored the paper with Dr. Arnold Satterthwait and others.

The researchers created the NuBCP-9 peptide from Nur77, a potent pro-apoptotic protein.

Nur77 often moves from the nucleus to mitochondria, in response to different death signals, where it binds to Bcl-2, changing its shape and function.

A report on this study has been published in the journal Cancer Cell. (ANI)