‘Survival protein’ protects the brain against effects of stroke

A “survival protein” that protects the brain against the effects of stroke in rodent brain tissue has been discovered by scientists at Johns Hopkins University. The finding has implications for treating stroke as well as Parkinson’s Disease, diabetes, and heart attack.

When brain tissue is subjected to a stressful but not lethal insult, a defense response occurs that protects cells from subsequent insult. The scientists dissected this preconditioning pathway to identify the most critical molecular players, including the Iduna protein. This protein increased three- to four-fold in preconditioned mouse brain tissue following an insult to the tissue, the scientists said.

The team exposed mouse brain cells to short bursts of a toxic chemical, and then screened these “preconditioned” cells for genes that turned on as a result of the insult. Focusing on Iduna, the researchers turned up the gene’s activity in the cells during exposure to the toxic chemical, which induced preconditioning. Cells deficient in Iduna did not survive, but those with more Iduna did.

The scientists found that the Iduna protein interferes with a particular kind of cell death that’s implicated in complications from diabetes and heart attack as well as stroke. By binding with a molecule known as PAR polymer, Iduna prevents the movement of cell-death-inducing factor (AIF) into a cell’s nucleus.

“Apparently, what doesn’t kill you makes you stronger,” says Valina Dawson, Ph.D. “This protective response was broad in its defense of neurons and glia and blood vessels — the entire brain. It’s not just a delay of death, but real protection that lasts for about 72 hours.”

Gene therapy for advanced Parkinson’s reduces symptoms

A multi-center gene therapy trial for patients with advanced Parkinson’s disease has demonstrated reduced symptoms of progressive movement disorder, reports Andrew Feigin, MD, associate professor of neurology and molecular medicine at The Feinstein Institute for Medical Research in Manhasset, NY.

The study was designed to deliver the gene for glumatic acid decarboxylase (GAD), packaged in inert viral vectors, into an area of the brain called the subthalamic nucleus. GAD makes an important inhibitory chemical called GABA. The subthalamic nucleus is abnormally activated in Parkinson’s disease, leading to debilitating movement problems.

All participants in the study had a positron emission tomography (PET) brain scan before the surgery to confirm the diagnosis of Parkinson’s disease. Each patient in the active treatment received about a billion viral vectors.

The treated group showed a 23 percent improvement on the United Parkinson’s Disease Rating Scale (which assesses motor symptoms), compared to a 12 percent improvement in those who received sham surgery.

Their work appears in the journal The Lancet Neurology.

Portable laser devices to improve disease diagnosis

Portable devices that use a laser beam to probe bones, teeth, and other parts of the body for early signs of diseases like osteoporosis and tooth decay may seem like something out of science fiction. But those devices are moving closer to reality, according to Chemical & Engineering News (C&EN).

These new diagnostic tools will have the ability to see beneath the skin and detect disease, without exposing patients to X-rays. They embrace a technology that involves focusing a laser beam painlessly through the skin onto a bone or onto the surface of a tooth. After hitting its target, the beam returns to an electronic detector with imprinted information that can reveal whether disease is present. Called Raman spectroscopy, the technology is a mainstay tool in chemistry laboratories that is finding a new life in medicine.

The article describes growing medical interest in Raman-based devices, especially for diagnosing osteoporosis and other bone diseases, and for tracking the effectiveness of treatment. Another application may be in very early detection of tooth decay, so that dentists can treat soft spots on tooth enamel before “drill-and-fill” becomes the only option. The technique could also mean blood tests done without taking blood samples, the article indicates.

Study Links More Time Spent Sitting to Higher Risk of Death

A new study from American Cancer Society researchers finds it’s not just how much physical activity you get, but how much time you spend sitting that can affect your risk of death.

Researchers say time spent sitting was independently associated with total mortality, regardless of physical activity level. They conclude that public health messages should promote both being physically active and reducing time spent sitting. The study appears early online in the American Journal of Epidemiology.

To explore the association between sitting time and mortality, researchers examined the amount of time spent sitting and physical activity in relation to mortality between 1993 and 2006. They found that more leisure time spent sitting was associated with higher risk of mortality, particularly in women. Women who reported more than six hours per day of sitting were 37 percent more likely to die during the time period studied than those who sat fewer than 3 hours a day. Men who sat more than 6 hours a day were 18 percent more likely to die than those who sat fewer than 3 hours per day. The association remained virtually unchanged after adjusting for physical activity level. Associations were stronger for cardiovascular disease mortality than for cancer mortality.

When combined with a lack of physical activity, the association was even stronger. Women and men who both sat more and were less physically were 94% and 48% more likely, respectively, to die compared with those who reported sitting the least and being most active.

“Several factors could explain the positive association between time spent sitting and higher all-cause death rates,” said Dr. Patel. “Prolonged time spent sitting, independent of physical activity, has been shown to have important metabolic consequences, and may influence things like triglycerides, high density lipoprotein, cholesterol, fasting plasma glucose, resting blood pressure, and leptin, which are biomarkers of obesity and cardiovascular and other chronic diseases.”