As temperatures begin to cool, coughing and sneezing inevitably follow. So begins flu season in the United States — and preventable deaths, says David Kimberlin, M.D., University of Alabama at Birmingham professor of pediatrics and president-elect of the Pediatric Infectious Diseases Society.

“Each year, an average of 24,000 people in the United States start the flu season alive and by the end of it have been killed by it; that is enormous,” says Kimberlin, who co-directs the UAB Division of Pediatric Infectious Diseases.

Kimberlin says it is too early to forecast the extent of this flu season, but he cautions people to protect themselves.

“Regardless how severe a flu season is predicted to be, people should be concerned every year. They should get their annual flu shot anytime the flu vaccine is available. If you haven’t yet done so, stop and get it,” Kimberlin says.

“The strains that are circulating in the 2011-12 season are the same strains circulating this past year,” Kimberlin says. “That’s the first time that has happened in a very long time.”

That means there is no shortage of the flu vaccine. “We have a good supply already, so we have the best opportunity to protect the U.S. population from this deadly disease,” Kimberlin explains.

One of the strains included in this year’s influenza vaccine is H1N1, a pandemic strain that infected about 61 million people in 2009, according to the Centers for Disease Control and Prevention.

During the 2010-11 flu season, 115 children died of flu-related causes, according to the CDC’s Morbidity and Mortality Weekly Report; less than a quarter of them had received the flu vaccine, and nearly half of them were age 5 and younger.

Researchers have long known that regular exercise increases the number of organelles called mitochondria in muscle cells. Since mitochondria are responsible for generating energy, this numerical boost is thought to underlie many of the positive physical effects of exercise, such as increased strength or endurance. Exercise also has a number of positive mental effects, such as relieving depression and improving memory. However, the mechanism behind these mental effects has been unclear. In a new study in mice, researchers at the University of South Carolina have discovered that regular exercise also increases mitochondrial numbers in brain cells, a potential cause for exercise’s beneficial mental effects.

Their article is entitled “Exercise Training Increases Mitochondrial Biogenesis in the Brain.” It appears in the Articles in PresS section of the American Journal of Physiology – Regulatory, Integrative, and Comparative Physiology, published by the American Physiological Society.

The researchers assigned mice to either an exercise group, which ran on an inclined treadmill six days a week for an hour, or to a sedentary group, which was exposed to the same sounds and handling as the exercise group but remained in their cages during the exercise period. After eight weeks, researchers examined brain and muscle tissue from some of the mice in each group to test for signs of increases in mitochondria. Additionally, some of the mice from each group performed a “run to fatigue” test to assess their endurance after the eight-week period.

Results
Confirming previous studies, the results showed that mice in the exercise group had increased mitochondria in their muscle tissue compared to mice in the sedentary group. However, the researchers also found that the exercising mice also showed several positive markers of mitochondria increase in the brain, including a rise in the expression of genes for proxisome proliferator-activated receptor- coactivator 1-alpha, silent information regulator T1, and citrate synthase, all regulators for mitochondrial biogenesis; and mitochondrial DNA. These results correlate well with the animals’ increased fitness. Overall, mice in the exercise group increased their run to fatigue times from about 74 minutes to about 126 minutes. No change was seen for the sedentary mice.

Importance of the Findings
These findings suggest that exercise training increases the number of mitochondria in the brain much like it increases mitochondria in muscles. The study authors note that this increase in brain mitochondria may play a role in boosting exercise endurance by making the brain more resistant to fatigue, which can affect physical performance. They also suggest that this boost in brain mitochondria could have clinical implications for mental disorders, making exercise a potential treatment for psychiatric disorders, genetic disorders, and neurodegenerative diseases.

“These findings could lead to the enhancement of athletic performance through reduced mental and physical fatigue, as well as to the expanded use of exercise as a therapeutic option to attenuate the negative effects of aging, and the treatment and/or prevention of neurological diseases,” the authors say.

Study Team
The study was conducted by Jennifer L. Steiner, E. Angela Murphy, Jamie L. McClellan, Martin D. Carmichael, and J. Mark Davis, all of the University of South Carolina.

Forecasters are predicting this week’s heat wave to be one of the hottest this summer. Loyola physician available to comment on staying safe.

“When the temperatures and heat indexes get to these levels it can be a very dangerous situation,” said Tony Pangan, MD, Loyola University Health System physician specializing in pediatrics and adult internal medicine. “The elderly and the very young are the most vulnerable, but we all need to be on the lookout for signs of heat-related illnesses.”

Pangan says prevention and planning is important when dealing with extreme heat.
1. Prehydrate. Even before you step out the door, start drinking water.
2. Stay indoors in an air conditioned or well-ventilated building.
3. If you have to go outside, stay out of the sun.
4. If you must be outside performing strenuous activity be sure to drink water at least every hour even in you don’t feel thirsty.

Warning signs of being overheated:
1. Confusion
2. Dizziness
3. Unusual fatigue
4. If you stop sweating
5. Take your temperature. If it’s rising without signs of infection contact your doctor.