A Clinical Lesson in Circadian Rhythms.
The dust is still settling, but what we now see...is
probably the outline of how a large part of biological timing works at the
molecular level. It's been quite a ride.
— Jay C. Dunlap, "Molecular Bases for Circadian Clocks,"Cell, 1999.
The results of circadian research may hold the promise of significant medical applications. At the most basic level, circadian variations affect both the course of disease and the efficacy of medications. A pill taken in the morning, for example, may not have the same biochemical effects as an identical pill taken at day's end.
Circadian studies have also led to such practical applications as treatment for jet lag, now understood to be the result of a disconnect between the master biological clock and local tissue clocks. In addition, research has led to a fuller understanding of the physiological consequences of shift work. It has also shed new light on a variety of mood and sleep disorders — some only recently recognized.
 Credit 51 |
Blood Analyzer on a Chip. This i-Stat portable blood analyzer provides quantitative determination of specific analytes in human whole blood — many of which vary according to time of day — as for example, red blood cells and concentrations of carbon dioxide, sodium, potassium, and glucose. |
 Credit 25 | |
Peak Performance — Physiological Functions that Show Circadian Variation.
This chart shows some of the many physiological human measurements and
susceptibilities that vary with the time of day. Lines indicate duration, and
points indicate when peak output is generally reached. | |
Light Therapy — Light Boxes, Reverse Sunglasses, and Knee Pads.
| |
