News and notes from the world of science

• In a recent Snippet it was noted that a virus called XMRV was implicated as a possible causal agent in Chronic Fatigue Syndrome (CFS). The study by an American lab reported that 67 percent of the CFS patients tested positive for the virus. Now a British group reports it tested 200 CFS patients and could not detect the virus. The two groups are challenging each other’s testing protocols. This is a good example of the way science proceeds. When a lab publishes what it believes is a significant finding, it is not accepted by the scientific community until the study is replicated by other labs. This is the way progress is made in science and medicine. Now we hear that the American group tested blood from some of the British CFS patients, and found the virus in 36 percent of them. Stay tuned, for a big controversy is brewing about CFS and viruses. (The Economist, Jan. 9, 2010)

• Scientists in Alaska reported their efforts to monitor the body temperature of a hibernating bear. After locating a sleeping bear, one scientist crawled into the bear’s den and inserted a thermometer with a remote read-out into the bear’s rectum. This allowed them to obtain readings outside the den. They were surprised to learn that hibernating bears move around a lot, and this one kept ejecting the thermometer. Finally, after the bear settled down, they obtained a good series of measurements. The scientists were excited as the bear’s temperature slowly declined – until it reached a point far lower than any temperature ever measured by a hibernating animal. This finding would ensure them a publication in a scientific journal. When they re-entered the den to remove the temperature probe, they discovered the cause of the temperature decline. The bear was dead. (Neil Davis, in Alaska Science Nuggets, Univ. of Alaska Press, 2008)

• There has been a global decline in the size of frog populations. At first, researchers blamed everything from habitat destruction to ultraviolet radiation. Now there is evidence that a fungus may be one of the causes. The skin of frogs plays an important role in regulating the movement of ions, such as sodium, chloride, potassium, and calcium, into their bodies. These ions are key to maintaining the electrolyte balance in their blood. Researchers in Australia have discovered a fungus that grows on the skin of frogs that interferes with the movement of ions through the skin. This results in a drop in blood electrolytes leading to heart failure. Ways are being considered that would suppress the growth of fungus. (Science, Oct. 2009). [Comment: In Door County, there is some good news. Field observations in 2009 suggest an upswing in the population of some frogs, especially Leopard Frogs (Rana pipiens).]

• The brain is made up of two halves, and deep inside the brain on each side there is a seahorse-shaped structure called the hippocampus that is necessary for memory formation. This is one of the few brain regions where new neurons are formed. After age 30 in humans, the ability to form memories begins to slowly decline. One approach to stabilizing memory processing involves using certain drugs to stimulate production of a hippocampus protein called “neurotrophic factor,” or BDNF. When injected into old rats is was discovered that their memory function returned to nearly that of a normal young animal. Will such drugs work in humans? We’ll know within a few years. (Science News, Aug. 2006; J. of Neurophysiology)