Longer-Lived Blood Cells May Aid Cancer Patients
Scientists have found a way to help elusive blood stem cells multiply and thrive outside the body, offering cancer patients and others a ready supply of the life-giving cells, scientists said yesterday.
Doctors have long been trying to find a way to simply grow large numbers of the cells, which give rise to the immune system's red and white blood cells and are used to replace bone marrow after intense chemotherapy or radiotherapy. The cells are very difficult to find and filter out of the blood, and usually die after about a month in a laboratory dish.
But Mayumi Yagi, Stephen Bartelmez and colleagues at the University of Washington in Seattle and the Veterans Affairs Puget Sound Health Care System said they had coaxed stem cells into living in the lab for up to four months. Writing in the Proceedings of the National Academy of Sciences, they said they had transplanted their four-month-old cells into mice whose bone marrow was destroyed by radiation, and saved the lives of the mice.
One of the secrets was thrombopoietin, a hormone the team tested to try to encourage the growth of platelet cells involved in blood clotting. Bartelmez, who studies stem cells, found them flourishing in the cultures.
He said this might offer a new source of stem cells for patients whose bone marrow has been destroyed by cancer treatments. The harsh treatments often kill off the cancer, but they also leave a person without an immune system or a way to produce new blood cells. Infusions of stem cells can replace their bone marrow in days. The problem has been getting enough of the elusive cells.
Mental Decline Linked With Other Ailments
Most older people remain lucid, but those who don't often suffer from clogged arteries, diabetes or possibly the early stages of Alzheimer's disease, researchers reported yesterday.
The researchers at the Center for Aging and Health at the University of California at Davis concluded that treating atherosclerosis and diabetes might slow memory loss and cognitive decline in older people.
The study of nearly 6,000 elderly people tracked their cardiovascular health and tested their cognitive function by asking them to do tasks such as naming parts of the anatomy and folding a piece of paper in half. It also checked to see if they carried the ApoE4 gene associated with Alzheimer's disease.
"Seventy percent of individuals evaluated in this study showed no significant decline in cognitive function over the study period," study author Mary Haan, director of the center, wrote in the Journal of the American Medical Association.
"We found that individuals whose cognitive ability remained constant during the study had two factors in common: They did not carry any of the [ApoE4] genes . . . and they had little or no signs of diabetes or atherosclerosis," she wrote.
Those with atherosclerosis alone were three times more likely than healthy individuals to show a loss of function. Those with the ApoE4 gene and either atherosclerosis or diabetes were eight times more likely to suffer a loss of mental faculties.