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BEIJING, August 3 (Xinhuanet) -- Women who experience any form of gender-based violence are at greater risk of mental health disorders and related dysfunction and disability, according to Australian researchers Wednesday.Those who'd been through at least one form of this abuse -- which includes intimate partner violence, rape, sexual assault, or stalking -- were almost three times more likely to experience a mental health condition than those who were never victimized, according to Susan Rees, PhD of the University of New South Wales in Sydney, Australia, and her colleagues.Those who'd experienced three or four forms had an 11-fold greater risk, reported in the Aug. 3 issue of the Journal of the American Medical Association.The study "reveals a pattern of social disadvantage, disability, and impaired quality of life among women who have experienced gender-based violence," the researchers wrote.

WASHINGTON, Aug. 4 (Xinhua) -- Researchers have found a way to turn mouse embryonic stem cells into sperm and this finding opens up new avenues for infertility research and treatment, according to a study published Thursday in the online edition of journal Cell,A Kyoto University team coaxed mouse embryonic stem cells into sperm precursors, called primordial germ cells (PGCs), and shown that these cells can give rise to healthy sperm. The researchers say that such in vitro reconstitution of germ cell development represents one of the most fundamental challenges in biology.When transplanted into mice that were unable to produce sperm normally, the stem cell derived PGCs produced normal-looking sperm, which were then used to successfully fertilize eggs. These fertilized eggs, when transplanted into a recipient mother, produced healthy offspring that grew into fertile male and female adult mice. The same procedure could produce fertile offspring from induced pluripotent stem cells that are often derived from adult skin cells."Continued investigations aimed at in vitro reconstitution of germ cell development, including the induction of female primordial germ cell-like cells and their descendants, will be crucial for a more comprehensive understanding of germ cell biology in general, as well as for the advancement of reproductive technology and medicine," the researchers wrote.

WASHINGTON, June 16 (Xinhua) -- Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage. New research by a team of scientists at the University of Rochester has unveiled an important new mechanism that allows cells to recognize when they are under stress and prime the DNA repair machinery to respond to the threat of damage.Their findings will be published Friday in journal Science. Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage.The scientists, led by biologists Vera Gorbunova and Andrei Seluanov, focused on the most dangerous type of DNA damage -- double strand breaks. Unrepaired, this type of damage can lead to premature aging and cancer. They studied how oxidative stress affects efficiency of DNA repair. Oxidative stress occurs when the body is unable to neutralize the highly-reactive molecules, which are typically produced during routine cellular activities.The research team found that human cells undergoing oxidative stress synthesized more of a protein called SIRT6. By increasing SIRT6 levels, cells were able to stimulate their ability to repair double strand breaks. When the cells were treated with a drug that inactivated SIRT6, DNA repair came to a halt, thus confirming the role of SIRT6 in DNA repair. Gorbunova notes that the SIRT6 protein is structurally related to another protein, SIR2, which has been shown to extend lifespan in multiple model organisms."SIRT6 also affects DNA repair when there is no oxidative stress," explains Gorbunova. "It's just that the effect is magnified when the cells are challenged with even small amounts of oxidative stress."SIRT6 allows the cells to be economical with their resources, priming the repair enzymes only when there is damage that needs to be repaired. Thus SIRT6 may be a master regulator that coordinates stress and DNA repair activities, according to Gorbunova.

LOS ANGELES, July 18 (Xinhua) -- U.S. scientists have proven that oncogenes can change normal cells into stem-like cells, paving the way to a safer and more practical approach to treating diseases like multiple sclerosis and cancer with stem cell therapy.In a collaborative study, researchers from the Keck School of Medicine of the University of Southern California (USC), and the Children's Hospital of Orange County (CHOC) in California and Good Samaritan Hospital Medical Center in New York have successfully converted human skin cells into brain cells by suppressing the expression of p53, a protein encoded by a widely studied oncogene. This suggests that p53 mutation helps determine cell fate -- good or bad -- rather than only the outcome of cancer.Oncogenes are generally thought to be genes that, when mutated, change healthy cells into cancerous tumor cells.Study findings were appearing Monday on the website of the American Association for the Advancement of Science (AAAS)."The reality may be more complicated than people think," said Jiang F. Zhong, Ph.D., assistant professor of pathology at the Keck School. "What is a stem cell gene? What is a cancer gene? It may be the same thing.""When you turn off p53, people think the cell becomes cancerous because we tend to focus on the bad thing," Zhong said. "Actually, the cell becomes more plastic and could do good things, too. Let's say the cell is like a person who loses his job (the restriction of p53). He could become a criminal or he could find another job and have a positive effect on society. What pushes him one way or the other, we don't know because the environment is very complicated."Stem cells can divide and differentiate into different types of cells in the body. In humans, embryonic stem cells differentiate into three families, or germ layers, of cells. The reasons why and how certain stem cells differentiate into particular layers are not clearly understood. However, from those layers, tissues and organs develop. The endoderm, for example, leads to formation of the stomach, colon and lungs, while the mesoderm forms blood, bone and heart tissue. In its study, Zhong's team examined human skin cells, which are related to brain and neural cells from the ectoderm.When p53 was suppressed, the skin cells developed into cells that looked exactly like human embryonic stem cells. But, unlike other man-made stem cells that are "pluripotent" and can become any other cells in the body, these cells differentiated only into cells from the same germ layer, ectoderm."IPSCs (induced pluripotent stem cells) can turn into anything, so they are hard to control," Zhong said. "Our cells are staying within the ectoderm lineage."Zhong said he expects that suppressing other oncogenes in other families of cells would have the same effect, which could have critical significance for stem cell therapy. Future research should focus on determining which genes to manipulate, Zhong said.The study is slated to appear in the Proceedings of the National Academy of Sciences later this month, according to AAAS.

SAN FRANCISCO, Sept. 6 (Xinhua)-- Yahoo on Tuesday fired Chief Executive Officer Carol Bartz and replaced her temporarily with the company's chief financial officer."On behalf of the entire board, I want to thank Carol for her service to Yahoo during a critical time of transition in the company's history, and against a very challenging macro-economic backdrop," said Yahoo Chairman Roy Bostock in a news release.The Yahoo Board of Directors appointed CFO Timothy Morse as interim CEO who will manage the company's day-to-day operations until a permanent chief executive is chosen.Carol Bartz, chief executive of Internet company Yahoo Inc, is shown in this undated publicity photo released to Reuters January 13, 2009. Before Yahoo's formal announcement, several news organizations and tech blogs posted an email reportedly from Bartz sent from her iPad to all employees of the company."To all, I am very sad to tell you that I've just been fired over the phone by Yahoo's Chairman of the Board. It has been my pleasure to work with all of you and I wish you only the best going forward."Bartz, 63, took over the Yahoo CEO role from co-founder Jerry Young in January 2009, when the company was struggling to stay competitive and profitable in a market dominated by Google. However, Yahoo never reached the heights she had foreseen.In the most recent quarterly earnings report in June, Yahoo reported net revenue of 1.1 billion U.S. dollars, down 5 percent from last year.Morse, 42, was hired as executive vice president and CFO at Yahoo in July 2009. "It is an honor to be selected for this role," he said in a statement Tuesday.Yahoo said it is starting a search for a new permanent CEO and plans to hire a "nationally recognized executive search firm" to assist in the effort.

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