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.
Tests for BNP and NT-proBNP measure their levels in the blood in order to detect and evaluate heart failure. BNP was initially called brain natriuretic peptide because it was first found in brain tissue (and to distinguish it from a similar protein made in the atria, or upper chambers, of the heart, termed ANP). BNP is actually produced primarily by the left ventricle of the heart (the heart's main pumping chamber).