MONDAY, Dec. 3 (HealthDay News) -- Almost 20 percent of Americans, or more than 40 million adults, can't afford or access needed health care, according to a new U.S. government report released Monday.

Access to health care is the focus of this year's Health, United States, 2007 report from the Centers for Disease Control and Prevention (CDC). It shows that one-fifth of Americans couldn't afford one or more of these services: medical care, prescription medicines, mental health care, dental care, or eyeglasses.

"People tend to equate access to care with insurance," said report author Amy Bernstein, chief of the analytic studies branch at the CDC's National Center for Health Statistics. "But access to care is more than insurance."

"People assume that if you have health insurance of any kind that you're okay, but that's not the case," she added.

Among the other barriers are locales without enough doctors, lack of transportation to doctors and clinics, and shortages of such organs as kidneys for transplants.

That means that even when people "have health insurance there are still disparities," Bernstein said.

In 2005, almost one in 10 people aged 18 to 64 years old reported not being able to afford prescription drugs and almost 10 percent said they postponed getting the medical care they needed.

While it's not the only factor, a lack of health insurance remains a key to accessing care, Bernstein said.

"We have a lot of evidence that people who don't have health insurance are much less likely to receive services than people who do," she said. "Health insurance is critical."

Other findings in the annual report:

• About 30 percent of young adults 18 to 24 do not have a usual source of medical care, and 30 percent have no health insurance.
• Among adults 45-64, one in 10 lacks a usual source of health care. In this group, about one in every 20 has high blood pressure, a serious heart condition or diabetes but no usual source of medical care.
• In 2005, one out of five people under 65 said they had been uninsured for at least some part of the past year. Most in this group said they had gone without insurance for more than 12 months.
• About 10 percent of women aged 45 to 64 with incomes below the poverty line reported delaying medical care because of a lack of transportation.
• About one-third of children living below the poverty level didn't see a dentist in 2005, compared with fewer than one fifth of children in higher-income families.

Despite these problems, there were some gains, the report noted.

Last year, 87 percent of young children between 19months and 35 months old were vaccinated against bacterial meningitis, up from 41 percent in 2002.

Moreover, the percentage of adults with high cholesterol dropped, to 17 percent, down from 21 percent between 1988-1994.

Also, 25 percent of adults had untreated cavities in 2004, down from 50 percent in the early 1970s, the report said.

"There has been important progress made in many areas of health, such as increased life expectancy, and decreases in deaths from leading killers such as heart disease and cancer. But this report shows that access to health care is still an issue where we need improvement," CDC Director Julie Gerberding said in a prepared statement.

One expert believes the answer to the problem lies in a universal national health care system.

"It's scandalous that so many people in this country couldn't get needed health care," said Dr. Steffie Woolhandler, an associate professor of medicine at Harvard Medical School and a co-founder of Physicians for a National Health Program.

This is not only a problem for people who are uninsured, Woolhandler said.

"It's common that people have insurance, but because of gaps in their coverage like co-payments, deductibles and uncovered services, people report that they needed but couldn't get health care," she added.

More information

You can read the full report at the CDC.

THURSDAY, Nov. 8 (HealthDay News) -- The identification of a new marker is making it possible to track brain stem cells for the first time, U.S. researchers report.

The achievement is already opening doors to new research into depression, early childhood development and multiple sclerosis, the team's senior author said.

"This is a way to detect these cells in the brain, so that you can track them in certain conditions where we suspect that these cells play a certain role," explained Dr. Mirjana Maletic-Savatic, an assistant professor of neurology at the State University of New York, Stony Brook.

"This is also very applicable for situations where people envision the transplantation of stem cells into the brain," the researcher said.

The breakthrough "is very important, because it now allows us to look and see ways in which to measure changes in endogenous [natural] neural stem cells," agreed Paul Sanberg, director of the Center for Excellence for Aging and Brain Repair at the University of South Florida, in Tampa. He was not involved in the research.

The study was funded by U.S. National Institutes of Health and is published in the Nov. 9 issue of Science.

Diseases such as Alzheimer's, Parkinson's and multiple sclerosis, as well as traumatic injury or stroke, all cause debilitating injury to the human nervous system and/or brain. However, because stem cells have the potential to develop into other types of cells, scientists believe they might be manipulated to repair or replace lost cells and tissues.

In fact, key parts of the brain already produce their own stem cells, also called progenitor cells.

"There are two major areas where you can find them in the brain -- one is the center for learning and memory, called the hippocampus, and the other is around the brains' ventricles," Maletic-Savatic explained.

Like other adult stem cells in the body, these cells are held in reserve, so they can develop into new or replacement cells -- in this case, brain cells.

Stem cells in the hippocampus are particularly useful, because humans keep collecting memories. "Memories always change," Sanberg pointed out, so the brain needs new cells with which to store and interpret them.

But research in this area has been stymied by the fact that scientists haven't had any means of tracking neural stem cells. A noninvasive technology called magnetic resonance spectroscopy (MRS) has long been used to track the brain's two dominant cell types -- neurons and glial cells -- because scientists discovered molecular markers that reliably identify them on MRS.

But a marker for brain stem cells has remained elusive -- until now.

Using cutting-edge scanning and computer technology, Maletic-Savatic's team has discovered a chemical signature -- as yet unnamed -- that distinctly characterizes neural stem cells. "We think that it's a complex lipid or lipoprotein," the Stony Brook researcher said. Further investigation is under way to define and describe the molecule's identity, she added.

In MRS imaging studies in mice and rats, as well as in healthy human volunteers, the researchers tracked the quantity and location of neural progenitor cells in the brain. They even transplanted some of these cells into an adult rat's brain and used MRS to verify the transplant's location.

And in another first, Maletic-Savatic's team compared the concentrations of neural progenitor cells in the brains of young children, adolescents and adult humans. They found that -- as had been suspected from animal studies -- the number of these cells in the brain decreases markedly with age.

"We were actually really surprised that there was such a dramatic decline," Maletic-Savatic said.

The researcher said she's already planning to use the new tracking technology in a variety of neurological studies.

For example, it is suspected that antidepressants work by boosting the creation of new brain cells. With that in mind, Maletic-Savatic's team will use MRS to "clarify whether abnormalities in these progenitors have any role in causing depression," she said.

And, because she is primarily a pediatric neurologist, Maletic-Savatic said she is also planning a study looking at the cells' role in early brain development, "particularly in premature babies who can develop cerebral palsy and mental retardation."

Finally, multiple sclerosis patients may also benefit from MRS-guided research into neural stem cells.

"We are now doing a study that already started a year ago on patients with MS, and we plan to prospectively follow them and see whether we can use this biomarker as a prognostic tool," Maletic-Savatic said.

Research into a wide variety of brain disorders could also benefit from this type of stem cell research she added. Tracking stem cells in the brain has obvious implications for research into stem cell transplantation, but Maletic-Savatic said breakthroughs in that area are probably years away.

"On the other hand, if we find drugs or ways that can stimulate your own endogenous cells, that would be even better," she said.

Sanberg agreed that the ability of researchers to track neural stem cells is a boon to brain research.

"To be able to show that you are increasing neurogenesis in the brain through your treatment -- through drugs that induce neurogenesis -- that's going to be very important," he said. "This is a really strong first step."

More information

Find out more on stem cells at the U.S. National Institutes of Health.

FRIDAY, Nov. 2 (Health Day News) -- A team of researchers has identified the biological mechanism by which stress increases susceptibility to skin infections.

"We have shown what stress does, the basis of the stress," said study author Dr. Peter Elias, a professor of dermatology at the University of California, San Francisco, and the VA Medical Center, San Francisco. Interestingly, it has nothing to do with the classic explanation of the immune system breaking down, he added.

Rather, it's a breakdown in the skin's antimicrobial defense, according to the study in the November issue of The Journal of Clinical Investigation.

Elias and his team subjected mice to psychological stress and found them more susceptible to group A Streptococcus pyogenes skin infections than mice kept under less stressful conditions.

The stressed-out mice showed a decrease in the expression of antimicrobial peptides by the skin's epidermis.

Streptococcal bacteria can cause many problems, such as skin infections, severe sore throats and even flesh-eating disease. The role of the peptides that Elias and his team studied have come to light in recent years, and it has been found that they are the "front line" of the immune system. They act like antibiotics, attacking bacteria and killing them.

In the study, Elias' team also found that the stress led to the increased production of glucocorticoids. This, in turn, inhibited the synthesis of fat in the skin's epidermis and reduced the secretion of vesicles containing antimicrobial peptides, setting up the mice for skin problems.

"What happens is, stress down-regulates the expression of two key families of antimicrobial peptides," Elias said. As that happened, skin infections became more severe in the animals.

When Elias' team blocked the production of the glucocorticoids, the skin's antimicrobial defenses returned to normal.

While many people think of the immune system's T-cells, which attack invaders, as the first line of defense, recent research suggests otherwise, Elias said. ""The antimicrobial defense mechanisms are so effective, they deal with 99.5 percent of all challenges by microbial pathogens, such as bad viruses, bad bacteria," he said.

In an accompanying commentary, Dr. Andrzej Slominski, of the University of Tennessee, wrote that "this study provides what I believe to be the first mechanistic link between psychological stress and increased susceptibility to microbial infection."

The research may eventually lead to new treatment options, such as topical medications that block excess glucocorticoid production.

More information

To learn more about skin conditions, visit the U.S. National Library of Medicine.

SUNDAY, Oct. 28 (HealthDay News) -- American consumers can get free tips on the safety and best use of household cleaners and disinfectants from the Soap and Detergent Association (SDA).

The Hard Surface Hygiene Fact Sheet outlines the safe, proper use of surface cleaning products and disinfectants. It describes surfaces where germs can linger and the types of products available for consumer and institutional use. It also provides brief summaries of common ingredients that make cleaning products effective and tips on safe and proper use, storage and disposal of products.

The fact sheet also includes a question-and-answer section and a list of Web sites where consumers can get more information.

"Our Hard Surface Hygiene Fact Sheet gives consumers, educators and public health professionals another information tool on products that help prevent the spread of germs that can make us sick," Nancy Bock, SDA's vice president of education, said in a prepared statement.

More information

Here's where you can find the Hard Surface Hygiene Fact Sheet  .