Researchers who have long sought to moderate side effects of pain-killing drugs have recently pinpointed a set of neurons that apparently is involved in disrupting normal sleep patterns in patients who are given morphine and similar opioid drugs.
When patients take morphine, the drug blocks pain as intended, but it also causes a decrease in production of acetylcholine, a brain chemical that is essential for rapid eye movement (REM) sleep. When acetylcholine levels are reduced and patients don’t get the normal amount of REM sleep, they may feel tired.
Dr. Ralph Lydic, a professor of anesthesia at Pennsylvania State University, said that discovering which brain neurons make acetylcholine enables scientists to now target those neurons with a new molecule intended to block the unwanted effects of morphine.
“This way the opioid could block the pain, and this new molecule could prevent the side effects,” Lydic said.
HELPING THE HEART
The same drugs used to suppress immune responses in people who receive transplanted organs might also help to prevent enlargement of the heart, researchers at the University of Texas Southwestern Medical Center at Dallas have learned.
The scientists found that enlargement of the heart, or cardiac hypertrophy, is controlled by a single protein produced in the body called calcineurin.
“Since calcineurin is the key signal forthe hypertrophic response cascade, we reasoned that cardiac hypertrophy could be treated with immunosuppressants cyclosporine A and FK506,” said Dr. Eric Olson, chairman of molecular biology at Southwestern. The two drugs are known to inhibit calcineurin.
The Texas researchers tested their ideas on mice that were genetically altered to give them enlarged hearts, and the scientists found that the drugs did, indeed, prevent heart enlargement.
If the drugs work as well in humans, the effect would be significant. An estimated 5 million Americans may be at risk of sudden death because of enlarged hearts.
KIDNEY TRANSPLANTS
When people suffer kidney failure, their best bet is to get a transplant as quickly as possible, new research suggests.
Putting these patients on dialysis machines that serve as artificial kidneys may save their lives in the short term, but it poses a threat in the long run, said Dr. Fernando Cosio, professor of internal medicine at Ohio State University.
“Dialysis is clearly not an advantage,” said Cosio. “Unless kidney failure is a surprise, which is rare, it doesn’t help patients at all to go through dialysis before a tranaplant.”
Cosio bases his opinion on a study of 523 transplant patients at Ohio State. Among the patients who never needed dialysis, only 7 percent died within seven years of receiving their transplanted kidney. But among those on dialysis for one to two years, 23 percent died within seven years of receiving their new kidney. And among those who had been on dialysis for more than three years, 44 percent died within seven years of their transplantation.
“The longer a person is on dialysis, the more likely it is that person will die and their death appears to be related to pre-transplant factors,” said Cosio, whose study was published in the journal Kidney International.
SMOKING’S NEW DANGERS
Besides the many known health hazards of smoking such as cancer, heart disease and strokes, scientists may be finding some new ones.
Researchers in the Netherlands report that the gradual decline in cognitive abilities seen in older people apparently is accelerated in those who smoke. In a study of more than 9,200 Europeans aged 65 or older, researchers from Erasmus University in Rotterdam performed the testing two years apart to gauge mental acuity.
The tests focuses on short-term memory, time and place orientation, attention and calculation.
The Dutch researchers reported to the recent annual meeting of the American Academy of Neurology that smokers suffered more declines than nonsmokers or former smokers.
“When comparing yearly cognitive change, we found current smokers had a significantly larger decline than people who stopped smoking and people who never smoked,” said Lenore Launder, an Erasmus researcher.
“Smoking may damage cerebral functioning by silent small strokes that aren’t clinically detected,” Launder speculated.
