Telomeres are the protective caps on the ends of chromosomes that affect how quickly cells age. They are combinations of DNA and protein that protect the ends of chromosomes and help them remain stable. As they become shorter, and as their structural integrity weakens, the cells age and die quicker.
See p 2392. B-type natriuretic peptide (BNP) is a neurohormone secreted mainly in the cardiac ventricles in response to volume expansion and pressure overload.1,2 Activation of BNP in patients with left ventricular (LV) dysfunction has generated considerable interest in both its diagnostic and prognostic properties.
Most scientific study has focused on ANP and BNP. Measurement of BNP helps doctors diagnose and treat congestive heart failure. In this condition, the heart is unable to pump blood efficiently, and the heart chambers swell with blood. As the heart cells stretch, they produce extra BNP, which pours into the bloodstream. By measuring blood levels of BNP, doctors can spot signs of congestive heart failure in its early stages, when it may be hard to distinguish from other disorders. A normal BNP level is about 98% accurate in ruling out heart failure.