中山肛门里面长了一个疙瘩(中山那治疗肛肠好点) (今日更新中)

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. 22 (Xinhua) -- Former eBay Chief Executive Officer and California governor candidate Meg Whitman on Thursday was named Hewlett-Packard's new CEO, replacing Leo Apotheker who served 11 months on the job."We are fortunate to have someone of Meg Whitman's caliber and experience step up to lead HP," said the California-based company in a statement."We are at a critical moment and we need renewed leadership to successfully implement our strategy and take advantage of the market opportunities ahead," said the troubled tech giant.It noted that the job of the HP CEO now requires additional attributes to successfully execute on the company's strategy, adding Whitman "has the right operational and communication skills and leadership abilities to deliver improved execution and financial performance.""I am honored and excited to lead HP. I believe HP matters -- it matters to Silicon Valley, California, the country and the world," said Whitman in a statement.Whitman, 55, joined the HP board in January and served as president and CEO of eBay from 1998 to 2008, when she led the company through its initial public offering and massive growth.During her last years at eBay, she is blamed for not being able to halt the sales slowdown and overpaying for the 2005 acquisition of Skype with 4.1 billion dollars. In 2009, Skype was sold by eBay at a valuation of 2.75 billion dollars.Whitman won the Republican nomination for governor of California in 2010. She lost the election to Gov. Jerry Brown after spending more than 140 million dollars of her own fortune on the campaign. EnditemHP said the appointments are effective immediately, following the decision that Apotheker stepped down as president and CEO and resigned as a director of the company.Multiple U.S. media reported on Wednesday that Apotheker was to be ousted, sending HP shares soaring on the market and in the after-hour trading.Apotheker, 58, was named HP CEO 11 months ago to replace Mark Hurd, who was ousted due to a scandal over a personal relationship with a company contractor and then became co-president of Oracle. Before HP, Apotheker had served as CEO of German software giant SAP for 10 months.On Aug. 18, Apotheker announced that HP will shut down its mobile business, spin off its core personal computer business and transfer into a cloud-based software and services provider for businesses including a 10.3 billion-dollar acquisition of British software company Autonomy.Shares of the company plunged 20 percent the following day, the worst one-day loss since Black Monday in 1987.On Sept. 30, 2010, the day before Apotheker's appointment as HP CEO, the tech giant's stock closed at 42.04 dollars. On Tuesday, the price closed at 22.47 dollars, a decrease of 46.6 percent in less than a year.On Monday, HP was reported to begin sending over 500 employees pink slips in the WebOS division, after announcing to stop making WebOS devices in August.

BEIJING, Aug. 3 (Xinhuanet) -- The first man in Britain who received a complete plastic heart is allowed to leave hospital and live a relatively normal life at home.Matthew Green, 40, who was dying from arrhythmogenic right ventricular cardiomyopathy, was awaiting a transplant when his condition became so bad that the doctors at Papworth Hospital, the world renowned heart center near Cambridge, decided to give him Britain’s first ever full artificial heart.During a six-hour operation on June 9, 2011, surgeons replaced Mr Green's damaged heart with the device which will serve the role of muscles and ventricles.Unlike previous artificial hearts, they have usually only replaced parts of the organ, the new one is powered by a pump which sits outside the body and can be held in a backpack or shoulder bag.All Mr Green has to do is replace the batteries in the pump every few hours and the heart should last up to three years.Transplant milestones1964 US National Institutes of Health starts artificial heart programme.1966 First transplant of partial mechanical heart, to assist pumping of ventricle.1969 Texas man receives first total artificial heart transplant. After 64 hours on the mechanical device received a donor organ, but died within two days.1982 Artificial heart designed by Utah University doctor Robert Jarvik implanted into man who survived for 112 days.2001 First surgical implant of internally powered artificial heart, which was charged via transduction through skin.

BEIJING, Sept. 8 (Xinhuanet) -- Middle-aged white women drinking alcohol moderately are more likely to stay healthy than nondrinkers, according to a new study from Harvard.The study has followed about 14,000 mostly white women since 1976.As a result, compared with teetotalers, those who had 3 to 15 alcoholic drinks weekly in their late 50s were 28 percent higher of being free from physical disability, chronic illness, mental health problems, and cognitive decline at the age of 70.Even having just one or two drinks per week increased a woman's odds of good health by 11 percent.However, women should be aware that even moderate drinking has been linked to an increased risk of breast cancer, said Qi Sun, M.D., a lead author of the study and a nutrition researcher at the Harvard School of Public Health.These findings don't necessarily apply to men or to nonwhite women. But they reinforced the evidence for the health benefits of moderate drinking.

BEIJING, July 5 (Xinhuanet) -- A new study showed that environmental factors may play a larger role in the development of autism than previously recognized, according to media reports on Tuesday.The new study in the Archives of General Psychiatry looked at 192 pairs of twins in California. It found autism was surprisingly common in fraternal twins, despite the fact that they don’t share as many of the same genes as identical twins, suggesting that something in their mutual life circumstances may be playing at least as strong a role as genetics.The study, which will likely be followed up with similar studies of twins and other siblings, could  force a dramatic swing in the focus of research into the developmental disorder.“It looks like some shared environmental factors play a role in autism, and the study really points toward factors that are early in life that affect the development of the child,” said study researcher Joachim Hallmayer, MD, an associate professor of psychiatry at Stanford University in California.

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