VITAMIN D: CAN TOO MUCH OF A GOOD THING BE BAD?

Mitosis: Too Much of a Good Thing (Can Be Bad)

Recent studies reveal that the precise regulation of microtubule dynamics is essential for an error-free mitosis. Kinetochore microtubule attachments that are too stable increase the rate of chromosome mis-segregation, a leading cause of chromosomal instability in tumors.

Vitamin D -- too much of a good thing?

Too much of a good thing: light can be bad for photosynthesis.

Even though light is the ultimate substrate for photosynthetic energy conversion, it can also harm plants. This toxicity is targeted to the water-splitting photosystem II and leads to damage and degradation of the reaction centre D1-polypeptide. The degradation of this very important protein appears to be a direct consequence of photosystem II chemistry involving highly oxidizing radicals and t...

Selenium supplementation in critically ill patients: can too much of a good thing be a bad thing?

A recent study by Forceville and colleagues evaluated the effect of high-dose selenium administration as a treatment for septic shock. The study was negative and conflicts with existing clinical data regarding selenium administration in critically ill patients. Perhaps the key to understanding the differences between these discrepant observations lies in considering the dose and timing of selen...

Hormones and Hearing: Too Much or Too Little of a Good Thing Can Be Ototoxic

Hormones regulate and modulate many physiological processes of the body including the nervous, cardiac, respiratory, and gastrointestinal systems. So, it is not surprising that hormonal regulation can manifest itself at the sensory level as well. The present report reviews some recent studies on the relations between several key hormones— including aldosterone and sex hormones—and auditory proc...