Vitamin A appears extremely beneficial for the health of an individual. According to Van Andel Research Institute (VARI) experts, vitamin A has a direct role in some physiological functions such as sperm cell formation and the development of the central nervous system. The research findings apparently have major implications in the medical world.

The derivatives of vitamin A like retinal and the retinoic acids possibly play a pivotal role in physiological functions of the human body. It was mentioned that vitamin A or retinol seems to be directly involved in nuclear receptor signaling pathways. This process allegedly activates genes in the human body. Vitamin A or retinol reportedly is a common dietary form of the vitamin and the parental compound of the retinoid group.

"Recent evidence has shown that orphan nuclear receptors are required for many essential physiological functions in the human body, and can be used to help discover drug targets for human diseases," said VARI Research Scientist Edward Zhou, Ph.D. "Additionally, the identification of ligands for nuclear receptors usually leads to the discovery of new types of therapeutic drugs for human diseases. A very successful example is PPARs (peroxisome proliferator-activated receptors), whose ligands are used for the treatment of diabetes."

In the course of the research, it was observed that vitamin A itself is purportedly active for promoting nuclear receptor TR4. This nuclear receptor presumably has a crucial role in sperm cell production, lipid and lipoprotein regulation, the development of the central nervous system and controlling hemoglobin production in the embryo. Hence, vitamin A may be a hallmark in human physiology. Nuclear receptors are believed to activate genes in vital biological processes of the human body.

Stroke survivors who are depressed may be more likely to lose some of their capability to function normally, a new study has found.

Although as many as a third of those who experience a stroke develop depression, a new study by researchers from the Regenstrief Institute, the schools of health and rehabilitation sciences and of medicine at Indiana University-Purdue University Indianapolis and the Richard L. Roudebush VA Medical Center is the first to look whether managing post-stroke depression improves physical functioning.

They researchers report that individuals who remain depressed three months after a stroke are more likely to have decreased functional capabilities than those whose depression was successfully treated.

Functional capabilities include getting dressed, feeding oneself, and accomplishing other tasks. These capabilities increased significantly in those individuals who were treated for depression.

Post-stroke depression appears to be linked to chemical changes in the brain, clinical evidence indicates.

"The relationship between post-stroke depression and recovery of function after a stroke has not been well understood. Previous researchers have looked at both depression and function after stroke but they did not investigate whether identifying and managing depression improved ability to accomplish tasks of daily living and other function related issues," said study first author Arlene A. Schmid, a Regenstrief Institute investigator, an assistant professor of occupational therapy at the IU School of Health and Rehabilitation Sciences and a VA Center of Excellence on Implementing Evidence Based Practice investigator.

The researchers in the new study report that successful depression management led to better functionality that might enable the individual to return to work or more thoroughly enjoy leisure functions while decreasing the caregiver burden.

"Restoring lost function after stroke is the number one reason individuals visit occupational therapists," said Dr. Schmid.

"Since treating depression helps improve function, occupational therapists should screen for post-stroke depression and, in conjunction with other members of the patient's health care team, help manage depression."

A new research has revealed that tamoxifen, taken by certain women as a preventive measure against breast cancer, saves lives and money.

The study's results suggest that the benefits of tamoxifen to prevent cancer can sufficiently compensate for its side effects in post-menopausal women under age 55 years who have an increased risk of developing breast cancer.

Research has shown that tamoxifen can protect against breast cancer for years after treatment ends, but identifying the group of women who can most benefit from the drug as a cancer preventive agent, without experiencing serious side effects, is a challenge. Side effects of the drug can include pulmonary embolism, endometrial cancer, deep vein thrombosis, and cataracts, as well as hot flashes and early menopause.

To investigate those women who would benefit the most from taking tamoxifen as a cancer preventive drug, Peter Alperin, MD, of Archimedes Inc. in San Francisco, and his colleagues used a mathematical model to simulate a post-menopausal population under age 55 years in a virtual clinical trial comparing tamoxifen treatment with no treatment.

The investigators modeled tamoxifen therapy based on an analysis of four randomized, placebo-controlled cancer prevention trials, and they assessed the effects that tamoxifen would have on women's breast cancer risk for 10 years following the end of treatment.

Cancer incidences and survival information were taken from the Surveillance Epidemiology and End Results cancer registry, while factors such as non-cancer disease incidences, quality of life, and costs were taken from the medical literature.

The researchers found that in post-menopausal women ages 55 years and younger with a 5-year risk of developing breast cancer of 1.66 per cent or greater, the benefits of tamoxifen are maximized while its side effects are minimized.

"In this group of women, using tamoxifen to prevent breast cancer saves lives and has a low frequency of side effects," said Dr. Alperin. He added that it also saves medical costs.

A simple and inexpensive blood test designed to uncover early signs of emphysema may one day find its place among the standard work-up that most Americans undergo during their yearly physical, new research suggests.

Although the novel screening method has shown considerable promise in preliminary investigations sponsored by the U.S. National Institutes of Health, the researchers caution that more studies are needed before the test could become available.

An easily administered test that could spot emphysema even before symptoms show up would be an enormous boon to the care of smokers, who are the most vulnerable to the onset of the disabling and potentially deadly disease.

"We know from other studies that smokers who learn from objective evidence that their health is in danger are much more likely to quit," Dr. Ronald G. Crystal, chairman and professor of genetic medicine and internal medicine at Weill Cornell Medical College and the study's lead author, said in a news release. "That is the only thing that will help them avoid this deadly disorder."

"We need a blood test that can be administered to the 20 percent of American adults who smoke as well as nonsmokers exposed to secondhand smoke -- all who may not understand their risk of developing this progressive lung disease," he added.

Crystal, who also serves as chief of the division of pulmonary and critical care medicine at New York-Presbyterian/Weill Cornell Medical Center in New York City, reported his team's findings in the March 14 online issue of the American Journal of Respiratory and Critical Care Medicine.

Emphysema and chronic bronchitis are the two main conditions of chronic obstructive pulmonary disease (COPD). In the United States, COPD is the fourth leading cause of death and has been projected to increase as the American population ages.

The new screening mechanism for emphysema was designed to measure the presence in the bloodstream of capillary debris, known as endothelial microparticles, or EMP, that results from injury to the lung's air sacs, called alveoli. The researchers noted that air sacs are central to respiratory function, and their COPD-driven deterioration ultimately shreds the lungs, producing the Swiss-cheese appearance that's telltale of the disease.

When tested on healthy nonsmokers, healthy smokers and smokers with signs of lung disease, the new test for EMP was found to be nearly foolproof in detecting early signs of emphysema, compared with the current emphysema screening method, known as DLCO, or lung diffusion testing, which measures how well the lungs exchange oxygen and carbon dioxide.

The new test, according to the researchers, also is better than the current one at uncovering the earliest signs of disease and can be done without the involvement of a pulmonologist.

In addition, they said, being able to easily diagnose emphysema at an early stage could be the leg up that health practitioners need to get their patients who smoke to finally kick the addiction.

Dr. Neil Schachter, a professor of pulmonary medicine at Mount Sinai Medical Center in New York City, agreed.

"Only about 15 percent of smokers will go on to develop emphysema," he noted. "So if you're a gambler and a smoker, which most are in a very general sense, it may not feel that urgent to stop smoking if you think you have a better-than-even chance of beating the game. But if you know you're in that 15 percent, it certainly is a powerful argument that physicians can bring forth to help convince people to stop smoking."

"But even so, smoking is a terrible, huge addiction," Schachter stressed. "It's difficult to convince people to quit, even when they know they have symptomatic disease. So it's not clear this will actually make a difference."

Edmund J. Miller, head of the Center for Heart and Lung Research at the Feinstein Institute for Medical Research in Manhasset, N.Y., echoed this reservation.

"Since the dangers of smoking have been emphasized in many ways, and many smokers do not quit even when the most severe symptoms have developed, it is perhaps unlikely that an individual will quit because of a blood test," Miller said. He added that biomarkers and early recognition of disease processes are valuable, however, and "the test may be useful in other settings where deterioration of lung function may be a late finding that perhaps could be prevented."

"This is a new finding in emphysema," Miller said, "but these particles [EMP] have been proposed as potential biomarkers for several other diseases, including sepsis and vasculitis."

Dr. Norman Edelman, chief medical officer of the American Lung Association (ALA), agreed that it's unknown whether the new test would prove to be a quit-smoking aid.

"I cannot predict whether this new test will be an important tool in helping doctors convince their patients to stop smoking," Edelman said. "The ALA recommends that doctors make strong efforts at smoking cessation for all of their smoking patients, as it is proven that doctors' intervention is an effective way to get people to make a serious attempt to quit." How much this test might add to either the quality of the doctors' efforts or the patients' response was uncertain, he noted.

But Schachter added that early detection can make all the difference in managing emphysema.

"If you catch the disease early, while there may be some microscopic damage, you are still way ahead of the game," he said. "And if the person stops smoking and takes proper prevention measures, such as following a healthy lifestyle, you could probably slow down the disease and maintain it at a level as either asymptomatic as it is at the time of discovery or mildly symptomatic."

Fathers-to-be should stop smoking to protect their unborn child from the risk of stillbirth or birth defects, scientists say.

University of Nottingham researchers found that pregnant women exposed to smoke at work or home increased their risk of stillbirth by 23% and of having a baby with defects by 13%.

They looked at 19 previous studies from around the world.

A UK expert said it was "vital" women knew the risks of second-hand smoke.

The studies used to pull this research together were carried out in North America, South America, Asia and Europe.

All the studies focused on pregnant women who did not smoke themselves but were passive smokers due to their proximity to a partner who smoked or work colleagues who smoked.

The combined data from the studies suggests that being exposed to more than 10 cigarettes a day is enough for the risks to be increased.

However, the University of Nottingham study did not find an increased risk of miscarriage or newborn death from second-hand smoke - only an increased risk of still birth and birth defects.

The results did not point to a link with any specific congenital birth defect.
Impact on sperm development

The researchers say fathers who smoke should be more aware of the danger they pose to their unborn child.

Previous research has shown that women who smoke during their pregnancy create serious health risks for their unborn baby, including low birth weight, premature birth and a range of serious birth defects such as cleft palate, club foot and heart problems.

Dr Jo Leonardi-Bee, lead researcher of the study and associate professor in medical statistics at the University of Nottingham, said they still did not know when the effects of the second-hand smoke begin.

"What we still don't know is whether it is the effect of sidestream smoke that the woman inhales that increases these particular risks or whether it is the direct effect of mainstream smoke that the father inhales during smoking that affects sperm development, or possibly both.

"More research is needed into this issue although we already know that smoking does have an impact on sperm development, so it is very important that men quit smoking before trying for a baby."

Dr Leonardi-Bee added: "The risks are related to the amount of cigarettes that are smoked so it is therefore very important for men to cut down.

"Ultimately though, in the interests of their partner and their unborn child, the best option would be to give up completely."

Andrew Shennan, professor of obstetrics at St. Thomas' Hospital in London and spokesperson for baby charity Tommy's, said: "It is vital that women are made aware of the possible risks associated with second-hand smoke and alert those around them of the impact it could potentially have on the health of their unborn baby.

"The chemicals in cigarettes are known to significantly increase the risk of serious pregnancy complications."