Meconium is essentially a baby's first bowel movement, excreted in the womb, and often expelled with the amniotic fluid. It is considered a sign of fetal distress. A small percentage of newborns inhale a mixture of meconium and amniotic fluid, which can lead to serious lung injury or infection.

"Meconium in and of itself is not necessarily a bad thing," Dr. Jennifer Wu, an obstetrician/gynecologist at Lenox Hill Hospital in New York City, explained. "It's a bad thing when you have meconium complications like aspiration. It's like being born with the umbilical cord around the neck. Twenty-five percent of babies are born this way, but for most of them, it's not a big deal. It's the same thing for meconium. Only a small number of [babies born with] meconium-stained fluid actually aspirate."

In fact, 11 percent of babies aspirate meconium-stained fluid, but the situation is not dire in all cases.

It's unclear how this latest finding will actually help physicians and expectant mothers during delivery.

"At this point, I don't know what we're going to do with this data," said Wu. "It's not like you would do anything differently or perform a C-section. We need additional studies in order to find a clinical intervention that can help."

The findings were expected to be presented Tuesday at the American College of Obstetricians and Gynecologists annual meeting, in New Orleans.

For this study, researchers from Lincoln Medical Center in the Bronx, N.Y., drew blood to measure levels of a hormone, inhibin-A, in 19 pregnant women who had had a normal pregnancy and delivery.

Inhibin-A levels were higher in four women who had normal pregnancies but who passed meconium during delivery. The test was conducted during the second trimester.

More information

The Nemours Foundation has more on meconium aspiration.

While cough and cold medications for children are widely marketed in the United States, how frequently they are used had not been scientifically studied. This new finding, from researchers at Boston University's Slone Epidemiology Center, gives increased weight to recent revelations that cough and cold medication use can lead to serious adverse effects, including death.

"Given concerns about potential harmful effects and lack of evidence proving that these medications are effective in young children, the fact that 1-in-10 U.S. children is using one of these medications is striking," study author Dr. Louis Vernacchio, an assistant professor of epidemiology and pediatrics at Boston University School of Medicine, said in a prepared statement.

Yet, the researchers also reported positive news in children's use of cough syrup and other drugs. The overall use of cough and cold medications declined from 12.3 percent in 1999-2000 to 8.4 percent in 2005-2006, they found.

The findings were scheduled to be presented Saturday at the Pediatric Academic Societies meeting in Honolulu.

Researchers analyzed data gathered between 1999 and 2006 through a national telephone survey and considered all oral medicines approved by the U.S. Food and Drug Administration to treat children's coughs and colds.

In any given week, 10.1 percent of U.S. children took at least one cough and cold medication, the researchers found. In terms of active ingredients, most used were decongestants and antihistamines (6.3 percent each), followed by anti-cough medicines (4.1 percent) and expectorants (1.5 percent).

Children aged 2 to 5 used the medications most often, but the rate was also high among those younger than 2.

More information

The American Association of Pediatrics has more about cold remedies for children.

"We have demonstrated significant differences in the changes in respiratory function that occur with asthmatic bronchoconstriction in relation to obesity," principal investigator Dr. D. Robin Taylor, of the University of Otago in New Zealand, said in a prepared statement.

The study also found that simple spirometry couldn't determine the level of pulmonary dysfunction in obese people with asthma.

The findings were published in the first issue for May of the American Journal of Respiratory and Critical Care Medicine. It's the first prospective study to find a significant comparative difference between obese and non-obese people in how the lungs and airways respond to a simulated asthma attack.

The researchers said it establishes a direct link between obesity and the development of dynamic hyperinflation -- air breathed into the lungs can't be expelled. This often occurs with acute asthma, but is more frequent in obese people.

The study included 30 asthmatic women who were divided into three groups based on their BMI: normal weight, overweight and obese. All the women breathed nebulized methacholine to induce an asthma-like attack and were then assessed for changes in lung function, including functional residual capacity (FRC -- how much air remained in the lungs after exhalation) and inspiratory capacity (IC -- how much air could be inhaled on the next breath).

"After the methacholine challenge, the amount of bronchoconstriction was identical for each of the three groups, but the changes in FRC and IC were greatest in the obese group. This indicated to us that greater dynamic hyperinflation was occurring among obese individuals," Taylor said.

The greater a woman's BMI, the higher her FRC and the lower her IC.

"This means that among women with greater BMI, an asthma-like episode has the potential to cause greater breathing difficulties than in non-obese women. The greater dynamic hyperinflation means that obese individuals lose the ability to inhale as deeply or exhale as fully as normal weight individuals," Taylor said.

The findings suggest fundamental differences in the way that obese people with asthma may experience shortness of breath.

"We know that asthma in obese subjects is more likely to persist and is more likely to be perceived to be severe. These individuals often require more treatment to achieve asthma control. Our study provides an insight into why this might be happening -- the same asthma trigger produces a greater effect in obese individuals," Taylor said.

More research is needed to "confirm that the differences in dynamic hyperinflation between obese and non-obese asthmatics are sufficient to explain the differences in symptoms between the two groups. Our study was not large enough to do this," Taylor said.

More information

The U.S. National Heart, Lung, and Blood Institute has more about asthma.

The development could potentially accelerate the traditionally challenging task of generating human antibodies, which can be used both to develop faster disease diagnostics -- for instance, to test for a new flu strain shortly after it emerges -- as well as safer and more effective medications, including vaccines.

"I think it's an important, incremental advance in our ability to provide antigen-specific monoclonal antibodies quickly and efficiently," said Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases. He was not involved with the study, but the institute did fund some of the research.

The findings were published online April 30 in the journal Nature.

When a person is exposed to a germ or a vaccine, the immune system mounts a series of challenges to confront the foreign particles. One of those responses involves so-called B cells, which begin to secrete antibodies. Antibodies are proteins, and each binds to a specific three-dimensional shape, or antigen, on the pathogen's surface, blocking its ability to enter cells, or marking it for destruction by other immune cells.

Each B cell can make only one type of antibody. But because most antigens are relatively large, there may be several different B cells whose antibodies will bind to any given antigen. The resulting pool of antibodies is termed "polyclonal," because it arises from multiple clones of activated B cells.

A monoclonal antibody, as its name implies, is the product of a single B-cell clone, so it binds just to a single shape on the antigen's surface. Monoclonals are useful biotechnology tools and have proven effective in clinical settings, too: A handful of monoclonal-based therapeutics are commercially available, including the anti-cancer drug, Herceptin.

But few, if any, of these monoclonals are human proteins, said Patrick Wilson, of the Oklahoma Medical Research Foundation, who led the new study with Rafi Ahmed of Emory University School of Medicine. Instead, for both ethical and practical reasons, monoclonals are usually made in mice. And that's a problem, because the human immune system recognizes the mouse proteins as foreign and sometimes attacks them instead. The result can be an allergic reaction, and sometimes even death.

To get around that problem, researchers now "humanize" the antibodies, replacing some or all of mouse-derived pieces with human ones.

Wilson and Ahmed were interested in the immune response to vaccination. Conventional wisdom held that the B-cell response would be dominated by "memory" B cells. But as the study authors monitored individuals vaccinated against influenza, they found that a different population of B cells peaked about one week after vaccination, and then disappeared, before the memory cells kicked in. This population of cells, called antibody-secreting plasma cells (ASCs), is highly enriched for cells that target the vaccine, with vaccine-specific cells accounting for nearly 70 percent of all ASCs.

"That's the trick," said Wilson. "So instead of one cell in 1,000 binding to the vaccines, now it is seven in 10 cells."

All of a sudden, the researchers had access to a highly enriched pool of antibody-secreting cells, something that is relatively easy to produce in mice, but hard to come by for human B cells.

To ramp up the production and cloning of these antibodies, the researchers added a second twist. Mouse monoclonal antibodies are traditionally produced in the lab from hybridomas, which are cell lines made by fusing the antibody-producing cell with a cancer cell. But human cells don't respond well to this treatment. So Wilson and his colleagues isolated the ASC antibody genes and transferred them into an "immortalized" cell line. The result was the generation of more than 100 different monoclonals in less than a year, with each taking just a few weeks to produce.

That's a far cry from the one to two years typically required to make a single monoclonal cell line, Wilson noted.

Said Fauci: "The advance here is that now when you vaccinate someone, you can have literally within a week these very important antibody-secreting cells that can serve as the source for developing monoclonal antibodies. [ASCs] come earlier, they are in abundance, and have high-affinity antibodies. So that's a pretty important advance in cases where you need monoclonal antibodies for a pathogenic antigen."

In the event of an emerging flu pandemic, for instance, this approach could lead to faster production of human monoclonals to both diagnose and protect against the disease, he said.

More information

To learn more about therapeutic monoclonal antibodies, visit the American Cancer Society.

"COPD is a double-edged sword: The incapacitating lung condition can cause such serious shortness of breath that everyday physical activity, such as walking a flight of stairs, becomes unduly burdensome -- and yet one of the few effective symptomatic treatments for COPD is the very thing that its victims dread most -- exercise," lead researcher Eileen G. Collins, of the Edward Hines Jr. VA Hospital in Hines, Ill., said in a prepared statement.

"One of the key mechanisms of shortness of breath and exercise impairment in these patients is their inability to fully exhale air when active," which causes trapping of the air in lungs (dynamic hyperinflation) and reduces breathing efficiency.

In a new study, Collins and her colleagues tested whether a computer program they're developing could reduce the amount of air trapping during exercise among COPD patients.

"Our primary goal was to determine if patients with COPD would achieve longer exercise duration if they were engaged in ventilation feedback, in addition to the regular exercise program over either ventilation feedback or exercise alone," Collins said.

The 64 patients in the study were divided into three groups: exercise only; exercise plus ventilation feedback (VF); or VF alone. Patients doing VF had their breathing monitored by a computer program that provided them with real-time biofeedback and set individualized goals, which were displayed on a computer screen. Patients could see their current speed and depth of breathing in relation to their set goal and respond by inhaling more slowly and exhaling more completely in order to reach that target.

Patients in the exercise/VF group showed significant improvements in exercise duration, and those in the exercise only group did much better than those in the VF only group. Patients in the exercise/VF group showed a greater reduction in exercise-induced hyperinflation than patients in the other two groups.

The study was published in the April 15 issue of the American Journal of Respiratory and Critical Care Medicine.

If COPD patients can be taught to use the computer program-associated breathing techniques while they do normal daily activities, they may be able to greatly improve their quality of life, Collins said.

More information

The American Academy of Family Physicians has more about COPD.