What do we mean by resistance? By resistance we mean that a microorganism is either not responding or responding minimally to an antibiotic to which that microorganism used to respond earlier. There are numerous mechanisms by which they develop resistance and this may be making themselves impermeable to drugs or making them inactive or mutating themselves, etc.

What is latest research going on? At present latest research that is going on is to how to reduce use of antibiotics by using them judicially so that microbes might not fall to prey of resistance and then be of no use to us.

Individuals who have had one concussion are at greater risk for another. For example, in one study of high school and college football players, concussions occurred about six times more frequently in student-athletes who had experienced prior concussions than in those who had not. Moreover, repeated concussions can have more severe outcomes than first concussions.

A rare but particularly scary phenomenon has been called "second impact syndrome" in which a second concussion occurring within days or weeks of an earlier concussion can produce catastrophic consequences—including death—way out of proportion to apparent severity of re-injury.

Because of potentially serious consequences, athletes, coaching staffs and parents need to have a heightened awareness of head-injuries and their need for proper evaluation, including by medical personnel. Various guidelines have been created for decisions about when it is safe to resume participation in contact sports. These guidelines, while based more on expert opinion than on medical evidence, are still best benchmarks we have until more studies are done.

All guidelines agree that an athlete needs to become symptom-free in all areas—thinking, memory, emotions, coordination, balance, etc.—before resuming play. After a first concussion, athlete should have been normal for at least a week, and after a second concussion, for probably two weeks.

When should an athlete hang up his or her cleats and retire from sport? How many concussions are too many? No one has a definite answer to either question. As Clint Eastwood's "Dirty Harry" might ask, "Are you feeling lucky?" Three concussions in same season—or even in an entire sports career—should certainly raise concern about long-term damage to brain.

Of course, student-athletes often pressure their parents to allow them to return to play sooner than might be wise. In these circumstances it is useful to recall that many professional athletes in football, hockey, boxing and other sports have retired from their lucrative careers rather than suffer additional concussions. If these high-profile individuals were willing to give up their big paydays in order to protect their brains, then perhaps your son or daughter will be able to follow their examples when less money is at stake. However, if you are parent and are being pressured to allow an early return to play, you just might have to stand tall, do right thing, and say no.

For more information about traumatic brain injury see websites of The Brain Matters and The Brain Injury Association of America.

(C) 2005 by Gary Cordingley