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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.

BEIJING, June 13 (Xinhua) -- The Chinese government on Monday launched a week-long campaign throughout the country which aims to make the public think more about food safety.Vice Premier Li Keqiang relayed to the campaign's organizer that it is essential to publicize knowledge and regulations on food safety among the public.Li, member of the Politburo Standing Committee of the Communist Party of China (CPC) Central Committee, said that special operations and severe punishment should be adopted to decrease the likelihood of food safety scandals.As part of the campaign, a food safety inspection team under the National People's Congress (NPC) Standing Committee held a conclusive meeting in Beijing to review its two-month supervisory tour to Jiangsu, Hubei, Sichuan and other four provinces and regions in April and May.A statement released by the inspection team on Monday said it will issue a report on food safety problems to the NPC Standing Committee.China's food safety has become a major public concern since a nationwide tainted milk powder scandal was exposed in August 2008.China's top legislature passed the Food Safety Law in 2009 which was soon followed by a nationwide food safety inspection.In the latest food safety scandal, drinks and food sold on the mainland but produced in Taiwan have been found to contain the toxic plasticizer DEHP.China's Ministries of Public Security, Agriculture, Health, as well as the General Administration for Quality Supervision, State Food and Drug Administration are also involved in the campaign.

COPENHAGEN, May 30 (Xinhua) -- The number of confirmed E. coli cases has risen to 14 in Denmark, with at least 26 others suspected of having the intestinal infection, the National Serum Institute said Monday.Seven of the confirmed cases show symptoms of kidney failure which marks an advanced stage of the sickness, the institute said."Almost all of the 14 infected people have been in northern Germany recently except just one. There is a 24-year-old man from Jutland. He has not even been to Germany, so he does not quite fit with the rest of the pattern," said Kaare Moelbak, chief physician at the institute. "We do not know yet how he has been so unlucky to get this infection but we assume that it has been a person-to-person transmission, or that he has eaten infected vegetables," he added.Denmark's Veterinary and Food Administration (DVFA) had advised Danish consumers not to eat raw tomato, lettuce and cucumber from Germany, and cucumber from Spain.It is now checking Danish cucumbers for traces of E. coli, with results expected on Tuesday.

NANNING, Sept. 1 (Xinhua) -- In south China's Guangxi Zhuang Autonomous Region, an area renowned for its history of musical folklore, local residents have found a unique way to spread knowledge regarding AIDS prevention."All people unite to fight AIDS! AIDS will stay away if we are equipped with AIDS knowledge," state the lyrics of one song that was penned by local songwriters as part of a local anti-AIDS campaign."We asked eight local singers to write and record songs about the disease. We think this is an effective way for local people to acquire AIDS knowledge," said 55-year-old Huang Zhanghui, a resident of the village of Shantun. He said that the songs are played through loudspeakers in his village every evening.The songwriting campaign has been effective because folk songs are a traditional artform in the region, making them more readily understandable and acceptable for local residents, Huang said.Guangxi has been one of the hardest-hit areas in China in terms of the number of AIDS infections discovered there, ranking only after central China's Henan Province. More than 76 percent of the infections are sexually transmitted, according to Ge Xianmin, an official from the AIDS prevention office of the Guangxi regional government.Bama County, which administers Shantun, is known for the longevity of its residents. Nearly 2,500 of its residents are more than 80 years old, and another 81 have celebrated their 100th birthdays."We will not let AIDS threaten this tradition," Huang said.Huang was selected to be the head of the village's AIDS prevention office just two months ago. In addition to the creation of folk songs, the office spreads AIDS prevention knowledge through text messages and publicly screened films.