THURSDAY, Sept. 27 (HealthDay News) -- School debt and income expectations are two main reasons many medical students decide to enter a high-paying specialty instead of becoming primary care doctors, according to a new long-term study.

The United States has a shortage of primary care doctors, who are among the lowest paid of all physicians. Primary care doctors are front-line health providers and usually are the first to diagnose illnesses. They also refer patients to specialists and coordinate care.

Primary care includes internal medicine, family practice and pediatrics.

In this study, researchers surveyed more than 2,500 medical students attending either New York Medical College or the Brody School of Medicine at East Carolina University between 1992 and 2010. The students were surveyed in their first and fourth years about the area of medicine they planned to enter, their expected debt upon graduation, their anticipated annual income five years after completing residency and the importance they placed on income.

Medical students who anticipated high levels of debt and placed a premium on high income were more likely to enter a high-paying medical specialty -- such as dermatology, radiology or anesthesiology -- than to enter primary care.

By graduation, 30 percent of the students who entered medical school with the intention of becoming a primary care doctor switched their preference to a high-paying specialty.

Those who changed their minds about becoming primary care doctors placed a higher value on income and had an 11 percent higher expected debt load than those who followed through on their goal of become primary care doctors.

The study was published online Sept. 19 in the journal Medical Education.

In 2010, 86 percent of medical students graduated with some education debt, according to the Association of American Medical Colleges. The average debt was $158,000, but 30 percent of graduates were more than $200,000 in debt.

"While the amount of debt medical students take on is well known, there hasn't been much research to assess how students respond to this pressure," study lead author Dr. Martha Grayson, senior associate dean of medical education at Albert Einstein College of Medicine at Yeshiva University in New York City, said in a university news release.

These findings suggests that measures such as incentive pay, debt forgiveness, additional scholarships and higher reimbursement for primary care services should be considered in order to meet the growing need for primary care doctors, the researchers said.

More information

The American Medical Association has more about health care careers  .

FRIDAY, Sept. 28 (HealthDay News) -- Eye proteins that can kill harmful bacteria may prove useful in developing new powerful and inexpensive antimicrobial drugs, according to a new study.

The finding was made by University of California, Berkeley, researchers investigating why eyes are so resistant to infection. They noticed that there is no bacteria living on the surface of the eye, unlike other surfaces of the body.

They also discovered that tissue from the eye's cornea -- the transparent part of the eye that covers the pupil and iris -- could destroy a number of types of bacteria in lab experiments.

"It is very difficult to infect the cornea of a healthy eye. We've even used tissue paper to damage the eye's surface cells and then plastered them with bacteria, and still had trouble getting bacteria to enter the cornea. So we proposed that maybe there were antimicrobial factors that are unique to the eye," study principal investigator Suzanne Fleiszig, a professor at UC Berkeley's School of Optometry who specializes in infectious diseases and microbiology, said in a university news release.

Further research revealed that small fragments of keratin protein in the eye play an important role in fighting bacteria. Fleiszig and her team then created synthetic versions of these keratin fragments and found that they destroyed bacteria that can lead to flesh-eating disease and strep throat, diarrhea, staph infections and cystic fibrosis lung infections.

The keratin fragments are relatively easy to make, which makes them good candidates for low-cost antimicrobial drugs, the researchers said.

"What's really exciting is that the keratins in our study are already in the body, so we know that they are not toxic, and that they are biocompatible," Fleiszig said. "The problem with small, naturally occurring, antimicrobial molecules identified in previous research is that they were either toxic or easily inactivated by concentrations of salt that are normally found in our bodies."

The study appears in the October issue of the Journal of Clinical Investigation.

More information

The U.S. National Institute of Allergy and Infectious Diseases explains antimicrobial resistance.

THURSDAY, Sept. 27 (HealthDay News) -- People with psychopathic traits -- such as callousness, manipulation, sensation-seeking and antisocial behaviors -- are not able to use their sense of smell as well as other people can, new research contends.

As a result, the investigators suggest that impaired sense of smell -- or "olfactory" function -- could be a marker for this severe personality disorder. The study, published online Sept. 18 in Chemosensory Perception, noted that the inability to smell is linked to dysfunction in the front part of the brain. Brain dysfunction also negatively affects the ability to plan, control impulses and abide by social norms in people with high psychopathy scores.

"Our findings provide support for the premise that deficits in the front part of the brain may be a characteristic of non-criminal psychopaths," the study authors explained in a journal news release. "Olfactory measures represent a potentially interesting marker for psychopathic traits, because performance expectancies are unclear in odor tests and may therefore be less susceptible to attempts to fake good or bad responses."

In conducting the study, Mehmet Mahmut and Richard Stevenson from Macquarie University in Australia examined 79 people with no criminal history to determine if they had an impaired sense of smell. They also assessed whether or not the study participants had psychopathic behavior, such as erratic lifestyles or criminal tendencies. The researchers also analyzed if the participants were able to empathize with other people's feelings.

The study authors found that the people with the most psychopathic traits were more likely to have trouble identifying or distinguishing between smells. The researchers concluded that the brain areas controlling sense of smell are less efficient in people with psychopathic tendencies.

Although the study found an association between impaired sense of smell and psychopathic behavioral traits, it did not prove a cause-and-effect relationship.

More information

The U.S. National Library of Medicine has more on mental health.

MONDAY, Sept. 24 (HealthDay News) -- It's good to be the boss. How good? New research suggests that leaders suffer from less stress than people in less powerful positions.

The findings in the new study don't prove that leadership is a natural stress reliever, however. It's possible that people with lower anxiety levels are better able to tolerate being at the top of the ladder.

Still, the research "does point to the importance of gaining leadership and a sense of control that would buffer against stress," said Gary Sherman, a postdoctoral fellow at Harvard University and the study's lead author.

The study results may seem to be counterintuitive. Popular culture suggests that leaders often are stressed-out workaholics, sometimes with a classic type-A personality. And there's also the common belief (although science still debates it) that stress leads to gray hair, a phenomenon that seems to be especially noticeable in men in an extremely powerful leadership position -- the U.S. presidency. (Then again, presidents may go gray just because they're getting older, like everybody else.)

The new study is the largest of its kind, Sherman said. In one experiment, the researchers asked 148 leaders and 65 non-leaders about their stress levels. The researchers also tested their levels of cortisol, a hormone linked to anxiety.

The leaders were at Harvard University to attend a leadership program. They included a variety of managers in fields such as finance, real estate and administrative services. Many worked for the government.

The leaders were more likely to be male and wealthier. They exercised more, consumed more caffeine, smoked less and woke up earlier (6 a.m. on average versus 7:30 a.m. for non-leaders). They also slept a bit less than the non-leaders.

The researchers found that the leaders reported being less stressed than the non-leaders. The levels of cortisol in the leaders were also 27 percent lower than in the non-leaders, Sherman said.

In another experiment, the researchers compared stress levels between leaders and lower-level leaders (75 people in total). Again, those with more power appeared to be less stressed.

"Among leaders," the study authors said, "lower stress levels go hand in hand with greater rank and power."

So what's going on? Previous research has suggested that a sense of control -- or lack of it -- has a major effect on stress levels, Sherman said.

Richard Elliot Wener, professor of environmental psychology at Polytechnic Institute of New York University, agreed. He has studied stress in commuters and found that they become more anxious as they lose control and the ability to predict what's going to happen.

"Lack of control and predictability are key to stress," he said. "If you're the boss, you control important factors."

The design of the new study didn't allow the researchers to reach firm conclusions, however. Researchers hope to later track stress in people over time to see what happens as they move up and down the career ladder, Sherman said.

The study appeared online Sept. 24 in the journal Proceedings of the National Academy of Sciences.

More information

For more about stress, try the U.S. National Library of Medicine.