Nitroglycerin Could Help Prevent Preterm Births

(HealthDay News) -- Giving nitroglycerin to women in preterm labor helps prolong their pregnancy and improves the health of their babies, Canadian researchers report.

The boost in newborns' health was greatest in those who were born very prematurely (24 weeks to 28 weeks), the study said.

Premature delivery is the leading cause of death and disability of newborns worldwide. According to the researchers at Queen's University in Kingston, Ontario, this is the first study to identify a drug that stops preterm labor and also improves infant outcomes. They said nitroglycerin causes fewer side effects than other drugs.

Published in the January issue of the American Journal of Obstetrics and Gynecology, the five-year study included 153 women who were recruited at the time they went into preterm labor.

Caring for premature babies and their medical complications can be costly for families and societies. Based on their findings, the researchers said that "treatment with nitroglycerin may result in major cost savings and longer-term health benefits for these babies."

The study was funded by the Canadian Institutes of Health Research.

More information
The U.S. National Institute of Child Health and Human Development has more about research into preterm labor and premature birth.

Health Tip: Exercising During Pregnancy

(HealthDay News) -- Assuming your doctor approves, exercise can help keep you healthy and feeling good during pregnancy.

While you should avoid strenuous activity, light exercise can offer many benefits during pregnancy.

The Nemours Foundation offers this partial list:

• Feeling better, having more energy, and getting better sleep at night.
• Reduced back pain and improved posture from stronger back, thigh and buttock muscles.
• Reduced stress and anxiety.
• Reduced risk of constipation.
• Less weight gain during pregnancy, and a quicker return to your pre-pregnancy weight.

Your body should tell you if it's had enough. Stop exercising immediately if you have any of the following symptoms:

• Fatigue.
• Dizziness.
• Heart palpitations.
• Shortness of breath.
• Pain in your back or pelvis.

Groundhogs, Other Hibernators, Could Aid Human Health

(HealthDay News) -- When Punxsutawney Phil popped up to look for his shadow Friday morning, he was not just forecasting how long winter will last.

Biologists now think that Phil and his fellow groundhogs, along with other animals in hibernation, could foreshadow advances in human health.

In fact, hibernators' amazing ability to manipulate their own metabolisms could lead to breakthroughs in improving organ transplant and in fighting such illnesses as obesity, diabetes, heart disease and even Alzheimer's, research shows.

"Remember, our physiology, and even our genetic makeup, isn't that different, in terms of basic bodily functions, [from] these hibernating mammals," said Hannah Carey, a professor in the School of Veterinary Medicine at the University of Wisconsin-Madison.

"The blueprint, the genes to do these things are there -- we're just not activating the same physiological pathways," said Carey, who is also president-elect of the American Physiological Society.

A wide range of mammals hibernate, from tiny squirrels to the grizzly bear. And hibernation isn't restricted to cold-weather climates: Scientists recently discovered that a Madagascar primate, the fat-tailed lemur, also goes into the hibernating state known as "torpor" during that tropical island's dry season.

"Torpor is a word we use for this state of physiological down-regulation," Carey explained. "Hearts slow down to a few beats per minute, and the animals are breathing only a few breaths per minute. Blood flow is very slowed, and their metabolism is suppressed."

Body temperature during torpor can fall to near-freezing in many hibernating squirrels, Carey added. In fact, the Arctic ground squirrel's hibernating temperature actually drops below freezing.

Close investigation of hibernating states is giving scientists new insight into animal physiology and, as a bonus, human health and disease as well. Some examples:

• Organ transplant. Harvested human organs kept at cold temperatures can only remain viable for a few days at most. So, how do squirrels' livers and intestines stay perfectly healthy at less than 40 degrees Fahrenheit for weeks on end? In one study, "we found that [hibernating] squirrels maintain, in a much healthier state, the microcirculation of the liver," Carey said. Insights into just how this happens could increase the viability and number of human organs available for transplant, she said.
• Heart attack. Rousing from weeks of torpor, hibernating mammals flood their near-dormant organs with fresh blood, a process called reperfusion. But doctors know that the speedy reperfusion of hearts after heart attack is, in itself, a major cause of damage to cardiac tissues. "But hibernators, faced with the very same kind of experimental insult, are very well-protected," Carey said. "They seem to have bumped up their defenses." Understanding those natural defenses might lead to better heart attack care, she said.
• Obesity. Gregory Florant, a biology professor at Colorado State University, has been studying the role in hibernation of a fat cell-secreted hormone called leptin. He explained that leptin, along with other biochemical signals, may help typically ravenous animals shut down their appetites as winter approaches. "Likewise, if we can determine what the hierarchy here is for shutting down the appetite, that may allow us to make gains on how to curb people's appetites so they don't eat as much," he said.
• Diabetes. Gearing up for hibernation means packing on weight -- a lot of weight. And hibernation means mammals turn into "the ultimate couch potatoes," Florant said. So, why don't these fattened-up bears, groundhogs and squirrels slip into type 2 diabetes, as humans so easily do? "That's a really interesting health perspective," Florant said. "They never go into frank diabetes, even though they become almost morbidly obese." Unraveling that mystery could lead to new ways to fight diabetes, he added.
• Alzheimer's. Carey pointed to another intriguing phenomenon: As the time mammals spend in torpor increases, vital cell connections begin to weaken within their brains. However, most hibernating mammals actually rouse themselves in their burrows every so often, and this appears to help these neural connections reestablish themselves. "So, people are saying, 'these guys are great models for things like Alzheimer's disease and [brain] lesions such as neurodegeneration,' " Carey said. In essence, hibernating mammals experience real brain damage, "but then they reverse themselves," according to Carey.

Finding out how that happens could further human brain research, she said.
With all of these physiological advantages, Punxsutawney Phil and his mammalian brethren appear to be on to something, the experts said.

"Different animals come up with different ways to cope with environmental stresses," Carey said. "Of course, we use our brains, so we have coats, electric heaters, that kind of thing. But it's really cold here in Wisconsin right now: Sometimes I look out there and think that maybe hibernation is a pretty smart idea."

More information
Find out more about groundhogs and Groundhog Day at Cornell University.

Gene Variant May Predict Heart Disease, Stroke

(HealthDay News) -- Researchers have identified a gene variant associated with the early signs of heart disease and stroke in women.
None of the more than 11,000 participants in the 25-year study has yet had heart disease or a stroke, but the signs point toward increased risk, said study author Dr. Edward Lammer, a pediatrician and geneticist at the Children's Hospital Oakland Research Institute in California. The report is published in the February issue of Atherosclerosis, Thrombosis and Vascular Biology.

"We found changes in two blood vessel areas," Lammer said. "In the coronary arteries, we found calcification. We also found thickening of the carotid arteries in the neck."

A buildup of calcium makes the coronary arteries less flexible and more vulnerable to damage. Thickening of the carotid arteries, the main blood vessels to the brain, can be a prelude to a stroke.

Those changes have been seen only in women. "We have no idea why," Lammer said, although it's possible that the signs of risk will develop later in men than in women.

Now, the researchers must wait to see whether women in whom the changes have been seen run into cardiovascular trouble.

They haven't so far, probably because they are too young, Lammer said. The study began in 1971 and has followed 11,377 residents of Muscatine, Iowa, since their early teens. The Oakland researchers are working with physicians at the University of Iowa on the study.

Lammer and his colleagues measured about 100 gene variants in the study participants. One of them, designated LTC4S, has been found to be associated with a fourfold increased risk of the early signs of heart disease and stroke, after adjustment for standard risk factors such as smoking, cholesterol and blood pressure levels, Lammer said.

"What's intriguing is that the gene variant we found is involved in regulating the inflammatory response," he said. "A research group from Iceland has reported that two genes in the same pathway are risk factors for stroke. This gene generates leukotrienes, chemicals that mediate the inflammatory response."

The LTC4S gene variant has previously been associated with asthma, "which in essence is an inflammatory reaction," Lammer said. "The hope is that our early results keep the finger pointed at the role of inflammation regulation as very important for atherosclerosis, heart disease and stroke."

The fact that the link between the gene variant and the danger signs seen so far is not associated with standard risk factors could make gene testing an important part of early risk assessment for many Americans, Lammer said. "About half the people in the study appear to have this variant," he said.

Lammer and his associates are continuing to follow the people in the study to check on the incidence of heart disease and stroke associated with the gene variant.

"If it is a risk factor that is genetic, we could identify the risk factor very early in life and develop interventions, behavioral changes or medications that ameliorate the risk," he said.

More information
Background information about the genetics of heart disease is provided by the American Heart Association.