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Category Archives: Health

Tapping to Music May Help You ‘Hear’ It

Moving to the beat of music actually helps you hear the music better, according to a new study.

Researchers at McMaster University in Canada played a series of regular beats for study participants, half of whom tapped on an electronic drum pad while they listened while the other half listened without tapping.

The participants were asked whether the final beat was consistent with the preceding rhythm, and those who tapped while they listened were 87 percent better at detecting the rhythm change than those who didn’t tap.

“We found that tapping along while listening does more than help us feel and enjoy the music. It actually helps us hear it better,” Michael Schutz, an assistant professor of music, said in a McMaster news release.

He and his colleagues also found that participants who tapped to the beat were moreconfident in their answers about the rhythm change.

The findings, presented at the recent Acoustics Week in Canada conference in Quebec City, are important for music listeners, performers and educators, according to Schutz.

“From a young age, we teach students to move to the music while performing, and now we know at least one reason why this is beneficial,” he said. “This study sheds light on why moving while playing helps musicians keep time and improves their overall performance.”

Research presented at meetings should be considered preliminary until published in a peer-reviewed medical journal.

Can You Catch Germs From a Public Toilet Seat?

There’s no denying that public bathrooms can be germ-ridden places. According to a study presented at the Infectious Diseases Society of America annual meeting, scientists who studied samples taken from a variety of public restrooms found that the sheer number of illness-causing bacteria present was too big to measure in many cases. So it’s only natural to worry about what may be lurking on even the cleanest-looking toilet seats — forget about the ones that appear wet or dirty.

No wonder that 60 percent of Americans say they won’t sit down to use a public toilet, according to the Web site of Sani-Seat, a company that makes those nifty gizmos that automatically wrap the seat in a fresh plastic cover after each use.

But experts say our fear of sitting on the average toilet seat (one that isn’t visibly soiled) is overblown.

There’s no question that germs can inhabit the seat, says Philip Tierno, MD, director of clinical microbiology and diagnostic immunology at New York University Medical Center and Mt. Sinai Medical Center in New York City. “The bulk of the organisms found are basically fecal-borne bacteria.” These nasties can include E. coli (which can cause bloody diarrhea or abdominal cramps), streptococcus (the bug behind strep throat), or S. aureus (linked to serious skin problems or pneumonia).

But just because they’re on the seat doesn’t mean they’ll make you sick. That’s because your skin acts as a very effective barrier to keep germs out (unless you have an open wound or lesion on your behind).

What about the herpes virus, HIV, or other sexually transmitted diseases? These organisms don’t survive for long outside the human body, especially not on a cold, hard toilet seat. And to infect you, they need to enter either through an open cut or sore or via a mucous membrane (your mouth or rectum, for example), which wouldn’t normally come into contact with the seat. All this makes the odds of infection from just sitting down miniscule.

Are you safer if you use those paper seat protectors? Dr. Tierno isn’t a fan: “They’re too thin, they rip and fall apart.” If you want to use them, he says, you can double-fold them, or place double-folded toilet paper on the seat. The automatically replaced plastic covers are better, he says, but such barriers on the seat act more as psychological than physical protection.

That said, no one wants to sit on a visibly dirty or soiled seat. Use common sense, Tierno says: “If [the toilet seat is] dirty, don’t use it.” But in general, he says, “You’re unlikely to pick up anything from a toilet seat.”

Where Germs Really Hide

But germs aren’t only found on the seat itself. “Where you find the organisms in larger quantities would be the underside of the toilet seat, because that is not cleaned as often [as the top]. As you flush, you bring up the contents in the bowl,” says Tierno. “It’s not just your germs, it’s germs from other people.” Some toilets can aerosolize the contents for quite a distance after being flushed, he says: “five feet or so, with lower-volume flushes.” Older toilets can spray as far as 20 feet! If you’re using a public toilet that doesn’t have a lid, Tierno recommends opening the door first before you flush, to get out of the way of the spray quickly.

And those far-reaching flushes may be responsible for another germ-ridden area of a typical public restroom: the floor. An ABC News investigation of the germiest spots in public bathrooms found that the floor has about 2 million bacteria per square inch! If you carry a purse or shoulder bag, avoid putting it down on the floor while you’re in the bathroom — hang it on the back of the door if possible.

Scrub Up!

But the real danger in picking up and carrying around germs comes from your hands, warns Tierno: “The 10 dirtiest things are your fingers.” Germs left on your hands can be easily transferred to surfaces you touch or to your eyes, mouth, or nose — where they can make you and other people sick. That’s why hand-washing with lots of soap and water is so important after using the bathroom.

And we’re talking especially to you, gentlemen: In a 2010 study, the American Society for Microbiology found that only 77 percent of men wash their hands before leaving the bathroom, compared with 93 percent of women.

What’s the best way to scrub? The Centers for Disease Control and Prevention recommends that you rub your hands with soap lather for at least 20 seconds (the amount of time it takes to sing “Happy Birthday” twice), and be sure to scrub the backs of your hands, between your fingers, and under your nails. If soap and water is not available, Tierno says, use a quarter-sized drop of alcohol-based hand sanitizer. You can then use a paper towel to turn off the faucet and open the door to leave.

Too Much TV May Take Years Off Your Life

Spending your days in front of the television may contribute to a shortened lifespan, a new study suggests.

Researchers in Australia found that people who averaged six hours a day of TV lived, on average, nearly five years less than people who watched no TV.

For every hour of television watched after age 25, lifespan fell by 22 minutes, according to the research led by Dr. J. Lennert Veerman of the University of Queensland.

But other experts cautioned that the study did not show that TV watching caused people to die sooner, only that there was an association between watching lots of TV and a shorter lifespan.

Though a direct link between watching TV and a shortened lifespan is highly provocative, the harms of TV are almost certainly indirect, said Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine.

“As a rule, the more time we spend watching TV, the more time we spend eatingmindlessly in front of the TV, and the less time we spend being physically active,” Katz said. “More eating and less physical activity, in turn, mean greater risk for obesity, and the chronic diseases it tends to anticipate, notably diabetes, heart disease and cancer.”

Another explanation for the possible link may be that people who watch excessive amounts of TV “are lonely, or isolated, or depressed, and these conditions, in turn, may be the real causes of premature mortality,” he added.

The report was published in the Aug 15 online edition of the British Journal of Sports Medicine.

In the study, researchers used data on 11,000 people aged 25 and older from the Australian Diabetes, Obesity and Lifestyle Study, which included survey information about how much TV people watched in a week. Researchers also used national population and mortality figures.

In 2008, Australian adults watched a total of 9.8 billion hours of TV. People who watched more than six hours of TV were in the top 1 percent for TV viewing.

The statistics suggest that too much TV may be as dangerous as smoking and lack of exercise in reducing life expectancy, the researchers said.

For example, smoking can shorten of life expectancy by more than four years after the age of 50. That represents 11 minutes of life lost for every cigarette and that’s the same as half an hour of TV watching, the researchers said.

Without TV, researchers estimated life expectancy for men would be 1.8 years longer and for women, 1.5 years longer.

“While we used Australian data, the effects in other industrialized and developing countries are likely to be comparable, given the typically large amounts of time spent watching TV and similarities in disease patterns,” the researchers noted.

Dr. Gregg Fonarow, associate chief of cardiology at the David Geffen School of Medicine at University of California, Los Angeles, said that “there is increasing evidence that the amount of time spent in sedentary activity such at TV watching, distinct from the amount of time spent in purposeful exercise, may adversely impact health.”

And although participating in a regular exercise program can help, it may not be enough to offset the risks of spending too much of the rest of the day — while at work or at home — getting no exercise whatsoever.

“Staying active and reducing time spent sedentary may be of benefit in reducing the risk of cardiovascular disease and may be considered as part of a comprehensive approach to improve cardiovascular health,” Fonarow added.

Dr. Robert J. Myerburg, a professor of medicine at the University of Miami Miller School of Medicine, added that “a sedentary lifestyle can reduce life expectancy.”

Myerburg isn’t sure why sitting around is not good for your health. “It’s better to look at it from a positive prospective,” he said. “That is: a physically active lifestyle is protective.”

New Bacteria Linked to Tattoo Infections

An investigation into skin lesions that two people developed after getting tattoos has concluded that both were infected with a bacteria not previously linked to the practice.

The infections involved Mycobacterium haemophilum, which usually only strikes individuals whose immune system are compromised. In this instance, however, the patients, both from Seattle, developed rashing despite the fact that both had normal immune systems, a report on the investigation found.

“Two people developed chronic skin infections after receiving tattoos at the same parlor,” explained study lead author Dr. Meagan K. Kay from the U.S. Centers for Disease Control and Prevention. “The patrons were thought to have been exposed through use of tap water during rinsing and diluting of inks.”

Kay, an epidemic intelligence service officer with the CDC, and her team report their findings in the September issue of the CDC’s journal Emerging Infectious Diseases.

The authors pointed out that tattooing is not considered a sterile procedure, is not regulated at the federal level and can be risky. And while the specific inks and colorings (pigments) commonly used to apply tattoos are regulated by the U.S. Food and Drug Administration, the rules usually apply only when cosmetics or color additives are involved.

The latest concern about associated infection risk arose in 2009 when a 44-year-old man and a 35-year-old man sought care for skin infections that had developed at the site of tattoos acquired at a facility in the Seattle region.

Lesion cultures and lab testing revealed that M. haemophilum was the culprit in the case of the first patient. Skin evaluations and patient interviews led the researchers to conclude that the second man most probably also suffered from the same sort of bacterial infection, although they technically classified his situation as a “suspected case.”

A follow-up investigation of the tattoo parlor revealed that municipal water had been used to dilute the ink during the tattooing process.

Water is considered to be a source for M. haemophilum. And though the facility was cleared of any safety violations, and no M. haemophilum bacteria was found in analyzed water samples, the tattoo operators were told to use sterile water for all future tattoo applications.

“It is important to remember that tattooing is not a sterile procedure and infections can occur after tattoo receipt,” Kay said. “Measures should be taken by tattoo artists to prevent infections, including proper training, use of sterile equipment, and maintaining a clean facility. Use of tap water during any part of the tattoo procedure should be avoided,” she explained.

“Those who suspect an infection in their tattoo should consult with their doctors,” she added. “Common infections can present as increased redness, warmth, swelling, pain and discharge.”

Myrna L. Armstrong, professor emeritus at the school of nursing at Texas Tech University’s Health Sciences Center in Lubbock, said the investigation serves to highlight the general risks of getting a tattoo.

“This is an invasive procedure. And there’s basically no regulation in force. Or very sporadic regulation. So as someone who’s been looking into tattoos and body piercing for more than 20 years, I would say that it’s really not very surprising that this can happen,” Armstrong said.

“So while I’m not being negative to the industry, I do think that the customer does need to be aware of the situation he or she is getting into,” she added. “Shop around, review people’s techniques, and make sure [you] really want to have this done.”

Cell Phones May Cause Brain Cancer

Cell phones may cause brain cancer, a panel of experts reporting to the World Health Organization (WHO) announced Tuesday.

After reviewing dozens of studies that explored a possible link between cancer and the ubiquitous hand-held phones, the experts classified cell phones as “possibly carcinogenic to humans” and placed them in the same category as the pesticide DDT and gasoline engine exhaust.

The panel determined that an increased risk for glioma, a malignant form of brain cancer, appears associated with wireless phone use.

Globally, it’s estimated that 5 billion cell phones are in use. “The number of users is large and growing, particularly among young adults and children,” the International Agency for Research on Cancer said in a news release issued Tuesday.

The IARC made the announcement in Lyons, France, based on the work of 31 scientists from 14 countries. It will present its findings to the WHO, which may then issue its recommendations on safe cell phone use.

Experts said children are especially vulnerable.

“Children’s skulls and scalps are thinner. So the radiation can penetrate deeper into the brain of children and young adults. Their cells are dividing at a faster rate, so the impact of radiation can be much larger,” Dr. Keith Black, chairman of neurology at Cedars-Sinai Medical Center in Los Angeles, told CNN.

Until Tuesday’s announcement, the WHO had said that cell phones were safe to use.

The international experts behind Tuesday’s announcement met for eight days to review exposure data, studies of cancer in humans and in experimental animals, and other relevant data, looking for associations between cancer and the type of electromagnetic radiation found in cell phones, televisions and microwaves.

Dr. Christopher Wild, director of the International Agency for Research on Cancer, said this new paper is important “first and foremost just because of the large number of users worldwide that have access now to this technology.”

Also, the scientists found notable gaps in the existing research, he said, which “suggest interesting areas of future research that will improve the evidence base which we have in order to make decisions about the usage of mobile phones in the future.”

Responding to Tuesday’s announcement, John Walls, vice president of public affairs for CTIA-The Wireless Association, a trade group representing the wireless industry said: “Today, an International Agency for Research on Cancer (IARC) working group in Lyon, France categorized radiofrequency fields from cellphones as possibly carcinogenic based on ‘limited evidence.’ IARC conducts numerous reviews and in the past has given the same score to, for example, pickled vegetables and coffee. This IARC classification does not mean cell phones cause cancer. Under IARC rules, limited evidence from statistical studies can be found even though bias and other data flaws may be the basis for the results.

“The IARC working group did not conduct any new research, but rather reviewed published studies,” Walls added in a news release. “Based on previous assessments of the scientific evidence, the Federal Communications Commission has concluded that ‘[t]heres no scientific evidence that proves that wireless phone usage can lead to cancer.’ The Food and Drug Administration has also stated that ‘[t]he weight of scientific evidence has not linked cell phones with any health problems.'”

There has been conflicting research in recent years on the health hazards posed by cell phones. As recently as February, British researchers reported that cell phones do not increase the risk of brain cancer.

Their analysis of data on newly diagnosed cases of brain cancer in England between 1998 and 2007 — when cell phone use was climbing — revealed no statistically significant change in the incidence of brain cancers in men or women, said the University of Manchester researchers.

There was a very small increase (0.6 more cases per 100,000 people) in the incidence of cancers of the brain’s temporal lobe. That works out to 31 extra cases per year in England’s population of nearly 52 million people, the researchers said.

But the study authors also noted that cancers of the brain’s parietal lobe, cerebrum and cerebellum in English men fell slightly during the study period.

7 Little Ways to Cut Cell Phone Cancer Risk

Does the World Health Organization’s statement that cell phones may cause cancerhave you thinking twice about making that phone call?

Of course it’s alarming to think that something that’s become such a can’t-live-without can be linked to brain cancer, but there’s a lot even the most cell phone-addicted people can do to minimize health risks.

Any potential links to cancer stem from the low levels of radiation cell phones emit. Lower your exposure to the radiation, and you’ll reduce the potential links to cancer or other health problems:

  1. Use a headset. Sounds obvious, but headsets emit much less radiation than cell phones do, according to the Environmental Working Group (EWG), and they keep your cell phone away from your head. The farther away you are from a source of radiation, the less damage it can do.
  2. Text when you can. Your constantly texting teens are onto something: Cell phones use less energy (and emit less radiation) when you text than when you talk, says the EWG. Texting also keeps the radiation source farther away from your brain.
  3. Use cell phones for FYI-only calls. Don’t use your cell phone for that long overdue, hour-long catch-up with your sister. Keep calls as short as possible —Do you need me to get the dry cleaning, honey? — and switch to a landline if they’re veering off into chitchat territory.
  4. Watch the bars. Can you hear me now? If you’re struggling to maintain a connection, ditch the call and wait until you have better service. When your phone has fewer signal bars, it has to work harder (and, therefore, emit more radiation) to connect.
  5. Keep the phone away from your ear when you can. EMF-Health.comrecommends waiting for the call to connect before you bring the phone to your ear, which minimizes radiation exposure. And when you talk, tilt the phone away from your ear and bring it in close when you’re listening. That’s because the radiation levels are “significantly less when a cell phone is receiving signals than when it is transmitting,” Lin Zhong, assistant professor of electrical and computer engineering at Rice University in Houston, told The New York Times.
  6. Don’t make calls in elevators or cars. You already it’s dangerous to talk and drive; EMF-Health.com says that cell phones use more power to establish a connection in enclosed metal spaces like cars and elevators.
  7. Make sure your kids use the landline. It seems like even toddlers are using cell phones today, but experts say kids are the most vulnerable to potential radiation dangers. The EWG says children’s brains absorb twice as much cell phone radiation as adults. According to The New York Times, health authorities in Britain, France, Germany, and Russia all have warnings against letting children use cell phones.

The Basics of Bell’s Palsy

Imagine waking up in the morning, looking in the mirror and realizing that one side of your face is sagging, your eyelid is drooping, and you are drooling out the side of your mouth. If you have ever had this experience, you were probably experiencing Bell’s palsy.

Bell’s palsy is the most common cause of facial paralysis. Although Bell’s palsy duration is usually limited to a few months, the symptoms can certainly be disturbing.

What Causes Bell’s Palsy?

Bell’s palsy can occur at any age but is most common at around age 40. Men and women are affected equally. Every year about 15 to 30 people out of 100,000 get Bell’s palsy. The cause of Bell’s palsy is not completely understood but is believed to be caused by a viral infection that causes swelling of the facial nerve.

The two facial nerves are large nerves that branch out across the face and carry electrical impulses to the facial muscles. Each nerve contains 7,000 nerve fibers. When the nerve swells in response to an infection, the electrical impulses get weak and the facial muscles lose their movement. Branches of the facial nerve are also important for tear and saliva production, and they transmit some taste sensations from the tongue.

Although the exact cause of Bell’s palsy is not always clear, certain risk factors are known to increase the chances of getting Bell’s palsy. Risk factors include:

  • Being exposed to herpes simplex virus type 1
  • Having diabetes
  • Being pregnant
  • Having had a previous episode of Bell’s palsy

Bell’s Palsy Symptoms

Bell’s palsy usually only affects one side of the face. Bell’s palsy symptoms usually start suddenly and reach their peak in 48 hours. Symptoms can range from partial to total paralysis. Common symptoms include:

  • Weakness of the facial muscles causing loss of facial expression
  • Twitching of the facial muscles
  • Drooping of the eyelid with inability to close the eye
  • Dryness of the eye and mouth
  • Loss of taste
  • Drooling from the corner of the mouth
  • Difficulty speaking clearly

Diagnosis and Treatment of Bell’s Palsy

The typical symptoms and sudden onset of one-sided facial weakness are sufficient to make a diagnosis of Bell’s palsy. Other types of diagnostic tests are not usually needed. If Bell’s palsy does not seem to be getting better over time, a referral to a neurologist or an ear, nose, and throat doctor may be needed to rule out other causes of facial paralysis such as tumors, Lyme disease, or multiple sclerosis.

Even without treatment, more than 80 percent of people with Bell’s palsy start to get better within three weeks. An early sign of improvement is often the return of taste. Bell’s palsy duration is rarely longer than six months. Some studies show that treatment can shorten Bell’s palsy duration and improve symptoms. Bell’s palsy treatment includes:

  • Steroids. The anti-inflammatory drug prednisone may be used to reduce swelling of the facial nerve. Prednisone may be started as soon as the diagnosis is made and tapered off over 10 days.
  • Antiviral drugs. Oral acyclovir (Zovirax) or valacyclovir (Valtrex) may be started within three days of Bell’s palsy symptoms and continued for seven days.
  • Eye care. Taping the eye closed, using an eye patch, and using artificial tears are helpful treatments to prevent eye irritation from excessive dryness.
  • Physical therapy. Messaging the face, exercising facial muscles, and applying gentle heat may help recovery.

Bell’s palsy can be a frightening experience. The good news is that even without treatment, most Bell’s palsy symptoms go away completely in time. Your primary care doctor can help you manage Bell’s palsy. In cases where symptoms are not improving, an ear, nose, and throat or neurological specialist should be consulted to rule out other causes of facial paralysis.

The Truth About Everyday Radiation Exposure

Japan’s ongoing nuclear crisis understandably has people around the world worried about radiation exposure and the potential health risks it may pose. According to the latest reports, radiation from Japan was detected in Southern California late this week, but experts are quick to point out that the levels are far from dangerous. The readings were “about a billion times beneath levels that would be health threatening,” a diplomat with access to United Nations’ radiation tracking told the Associated Press.

Nor is it unexpected. “Whenever radioactive particles get in the atmosphere, they have the potential to spread around the world,” says James Thrall, MD, president of the American College of Radiology. “But they get diluted as they travel, so they’re unlikely to pose any real health problem.”

In fact, we’re probably exposed to significantly more radiation every day than the miniscule fallout arriving from Japan. Here’s a quick tutorial on radiation to put our collective anxiety in perspective:

What Is Radiation?

Radiation is a form of energy in waves. It exists on a spectrum, with low-frequency radiation (from radio waves and microwaves) on the low end and high-frequency radiation (from gamma rays and x-rays) on the high end. All radiation affects the cells in our bodies to some extent, but the lower the frequency of the waves and the lower the exposure, the less dangerous it is.

To understand the risks of high-frequency radiation — the kind we’re talking about in this article — think back to high school physics: These waves have enough energy to knock electrons off molecules, which can cause damage to cell DNA that can ultimately lead to cancer.

How Are We Exposed to Radiation?

We encounter radiation each day from a variety of sources. The average American is exposed to about 6 millisieverts (mSv) of radiation annually, according to the United States Nuclear Regulatory Commission (USNRC). Half of this typically comes from background radiation that occurs naturally in the environment, and half comes from medical tests, such as X-rays, mammograms, and CT scans.

According to Kelly Classic, MS, spokesperson for the Health Physics Society, sources of environmental radiation include:

  • Radioactive compounds in soil and building materials like concrete, brick, and stone
  • Radiation from outer space that your encounter when you fly on airplanes or visit high-altitude places
  • The mineral potassium in your own body (a small fraction of potassium, which our bodies need to function, is radioactive)
  • Radon gas in the home, which accounts for about 2 mSv of exposure each year, and is the largest contributor of background radiation

Finally, there’s the kind of radiation released during nuclear reactions, such as what’s disseminating from Japan’s Fukushima Daiichi plant.

Here’s a look at various sources of radiation exposure (dose of radiation in millisieverts (mSv)), according to data from the Health Physics Society and the U.S. Environmental Protection Agency (EPA). By way of comparison, a single dose of radiation below 0.01 mSv is considered negligible by the National Council on Radiation Protection and Measurements.

  • Banana: 0.0001
  • Dental X-ray: 0.005
  • Living within 50 miles of a nuclear power plant: 0.01 (per year)
  • A flight from New York to Los Angeles: 0.04
  • Smoking 1 ½ packs of cigarettes: 0.08
  • Chest X-ray: 0.1
  • Living at sea level: 0.25 (per year)
  • Mammogram: 0.3
  • Living in Denver: 0.5 (per year)
  • Abdominal CT scan: 14
  • Measures between reactors No. 3 and No. 4 during the March 15 explosion at the Fukushima plant: As high as 400 per hour

What Level of Radiation Exposure Is Safe?

It’s well-established that exposure to large amounts of radiation at once can cause acute sickness and even cancer. (A 1,000 mSv-dose can trigger acute radiation sickness, causing symptoms such as nausea and vomiting; 3,000 mSV can be lethal, according to Thrall.)

But there’s no good data on the long-term risks of the low levels of radiation to which we’re continually exposed.

According to the World Nuclear Association, annual exposure to 100 mSv or greater carries a measurable, though small, increase in cancer risk. Below that level, it’s believed that your body’s cells are able to heal themselves from radiation. “There are enzyme systems in the body that repair damage from these low levels of background radiation,” says Thrall.

Cell Phones Affect Brain Activity

Holding a cell phone to your ear for a long period of time increases activity in parts of the brain close to the antenna, researchers have found.

Glucose metabolism — that’s a measurement of how the brain uses energy — in these areas increased significantly when the phone was turned on and muted, compared with when it was off, Dr. Nora Volkow, director of the National Institute on Drug Abuse, and colleagues reported in the Journal of the American Medical Association.

“Although we cannot determine the clinical significance, our results give evidence that the human brain is sensitive to the effects of radiofrequency-electromagnetic fields from acute cell phone exposures,” co-author Dr. Gene-Jack Wang of Brookhaven National Laboratory in Long Island, where the study was conducted, told MedPage Today.

Although the study can’t draw conclusions about long-term implications, other researchers are calling the findings significant.

“Clearly there is an acute effect, and the important question is whether this acute effect is associated with events that may be damaging to the brain or predispose to the development of future problems such as cancer as suggested by recent epidemiological studies,” Dr. Santosh Kesari, director of neuro-oncology at the University of California San Diego, said in an e-mail to MedPage Today and ABC News.

There have been many population-based studies evaluating the potential links between brain cancer and cellphone use, and the results have often been inconsistent or inconclusive.

Most recently, the anticipated Interphone study was interpreted as “implausible” because some of its statistics revealed a significant protective effect for cell phone use. On the other hand, the most intense users had an increased risk of glioma — but the researchers called their level of use “unrealistic.”

But few researchers have looked at the actual physiological effects that radiofrequency and electromagnetic fields from the devices can have on brain tissue. Some have shown that blood flow can be increased in specific brain regions during cell phone use, but there’s been little work on effects at the level of the brain’s neurons.

So Dr. Volkow and colleagues conducted a crossover study at Brookhaven National Laboratory, enrolling 47 patients who had one cell phone placed on each ear while they lay in a PET scanner for 50 minutes.

The researchers scanned patients’ brain glucose metabolism twice — once with the right cell phone turned on but muted, and once with both phones turned off.

There was no difference in whole-brain metabolism whether the phone was on or off.

But glucose metabolism in the regions closest to the antenna — the orbitofrontal cortex and the temporal pole — was significantly higher when the phone was turned on.

Further analyses confirmed that the regions expected to have the greatest absorption of radiofrequency and electromagnetic fields from cell phone use were indeed the ones that showed the larger increases in glucose metabolism.

“Even though the radio frequencies that are emitted from current cell phone technologies are very weak, they are able to activate the human brain to have an effect,” Dr. Volkow said in a JAMA video report.

The effects on neuronal activity could be due to changes in neurotransmitter release, cell membrane permeability, cell excitability, or calcium efflux.

It’s also been theorized that heat from cell phones can contribute to functional brain changes, but that is probably less likely to be the case, the researchers said.

Dr. Wang noted that the implications remain unclear — “further studies are needed to assess if the effects we observed could have potential long-term consequences,” he said — but the researchers have not yet devised a follow-up study.

“The take-home message,” Dr. Kesair said, “is that we still don’t know, more studies are needed, and in the meantime users should try to use headsets and reduce cell phone use if at all possible. Restricting cell phone use in young children certainly is not unreasonable.”

Medical Leech Linked to Infection

A resistant Aeromonas infection transmitted by a medicinal leech developed in a man undergoing reconstructive surgery of the jaw, leading to total failure of the graft, investigators reported.

“Leech therapy is the most effective nonsurgical management of soft-tissue venous congestion,” explained Dr. Brian Nussenbaum, of Washington University School of Medicine in St. Louis, and colleagues.

However, because a bug — Aeromonas hydrophila — lives in the gut of leeches where this bacteria aids in the digestion of blood, infections can occur in as many as 20 percent of patients treated with medical leeches, according to a report in the February Archives of Otolaryngology-Head and Neck Surgery.

So to prevent infection, researchers are recommending that when medical leeches are used, patients should be given antibiotics, preferably Cipro (ciprofloxacin) or Septra (trimethoprim-sulfamethoxazole).

The patient was a 56-year-old man undergoing a reconstructive procedure for a large benign tumor in his jaw. He was given ampicillin-sulbactam as prophylaxis.

Approximately 24 hours after the surgery, he developed a condition called acute venous congestion, meaning a lack of blood supply that turns skin and tissue blue, in the area of the surgery.

In preparation for revision of the surgery, which revealed widespread clot formation, the patient was given 400 mg of intravenous ciprofloxacin and three leeches were applied to the area.

Types of Surgery For Cancer Treatment

The surgery appeared to have been successful, but despite maintenance therapy with ciprofloxacin, 48 hours later purulent secretions appeared, and cultures with sensitivity testing identified a strain of A. hydrophila that was resistant to both trimethoprim-sulfamethoxazole and ciprofloxacin.

Ciprofloxacin was withdrawn and the fourth-generation cephalosporin, cefepime, was prescribed.

The wound did not heal completely and eight months later the patient required a second reconstruction eight months later.

When Bacteria Becomes Resistant to Antibiotics

To determine the source of this resistant infection, Nussenbaum’s group conducted a two-part investigation.

First, to see if the infection was acquired within their hospital, they performed cultures on samples of water from their leech tank — and found that all samples were susceptible to multiple antimicrobials, including ciprofloxacin and trimethoprim-sulfamethoxazole.

They also noted that no other resistant Aeromonas infections had been seen at their institution.

“This practice-based investigation suggests that this strain was not acquired within our hospital,” they stated.

They then conducted a broader investigation, contacting various organizations including the Centers for Disease Control and Prevention and the Emerging Infections Network, finding that no other cases of similar resistant infections associated with medical leeches had been reported.

The leech supplier also reported careful maintenance of holding tanks, although antibiotic resistance tests were not routinely done.

The investigators found, however, that ciprofloxacin-resistant strains of Aeromonashad been identified from environmental sources such as drinking water in Turkey, a lake in Switzerland, and the Seine River.

These isolates contained a plasmid encoding fluoroquinolone resistance, which had previously only been found in Enterobacteriaceae.

“These findings suggest the possibility of emerging ciprofloxacin resistance in environmental water supplies, which is concerning,” observed Nussenbaum and colleagues.

Limitations of the study included the investigators’ inability to culture the gut contents of other leeches from the same batch, and the lack of specimens that could be tested for the presence of the resistance-conferring plasmid.

The study suggests that, although resistance to trimethoprim-sulfamethoxazole and ciprofloxacin is rare in A. hydrophila, it can occur and should be considered when antibiotic prophylaxis is undertaken, according to the investigators.

“Surgeons using leech therapy should be aware of this possibility and collaborate with infectious disease specialists in their hospital to determine appropriate antibiotic prophylaxis on local resistance patterns,” they cautioned.