Fast DNA-sequencing machines are leading to simple blood tests for cancer. Availability: now A blood test to catch cancer early. Cancer kills some eight million people a year around the world. Everything about China is big, including its cancer problem. In some wealthier cities, like Beijing, cancer is now believed to be the most frequent killer. Air pollution, high rates of smoking, and notorious cancer villages scarred by industrial pollution are increasing death rates around the country. Liver cancer in particular is four times as prevalent as it is in the West, in part because one in 14 people in China carry hepatitis B, which puts them at risk. Of all the people worldwide who die of cancer each year, some 27 percent are Chinese. In December, I traveled by metro from Shenzhen to Hong Kong. There I had arranged to meet Dennis Lo, a doctor who has worked for nearly 20 years on a technique called the liquid biopsy, which is meant to detect liver and other cancers very earlyeven before symptoms ariseby sequencing the DNA in a few drops of a persons blood. Lo appeared fastidiously dressed as usual in a sharp blazer, a habit that called to … Continue reading →

Under normal conditions, many of the different types of tissue-specific adult stem cells, including hematopoietic stem cells, exist in a state or dormancy where they rarely divide and have very low energy demands. "Our theory was that this state of dormancy protected hematopoietic stem cells from DNA damage and therefore protects them from premature aging," says Dr. Michael Milsom, leader of the study. However, under conditions of stress, such as during chronic blood loss or infection, hematopoietic stem cells are driven into a state of rapid cell division in order to produce new blood cells and repair the damaged tissue. "It's like forcing you out of your bed in the middle of the night and then putting you into a sports car and asking you to drive as fast as you can around a race circuit while you are still half asleep," explains Milsom. "The stem cells go from a state of rest to very high activity within a short space of time, requiring them to rapidly increase their metabolic rate, synthesize new DNA and coordinate cell division. Suddenly having to simultaneously execute these complicated functions dramatically increases the likelihood that something will go wrong." Indeed, experiments described in the … Continue reading →