Defensin: A family of potent antibiotics made within the body by neutrophils (a type of white blood cell) and macrophages (cells that can engulf foreign particles). The defensins play important roles against invading microbes. They act against bacteria, fungi and viruses by binding to their membranes and increasing membrane permeability. On a chemical level, the defensins are small peptides unusually rich in the amino acid cysteine (Cys).The human defensins are classified into the alpha-defensins and beta-defensins on the basis of their sequence homology and their Cys residues.
From the Latin defendo, to repel. Defensin is also called human neutrophil peptide (HNP).
- Defensive medicine
Defensive medicine: Medical practices designed to avert the future possibility of malpractice suits. In defensive medicine, responses are undertaken primarily to avoid liability rather than to benefit the patient. Doctors may order tests, procedures, or visits, or avoid high-risk patients or procedures primarily (but not necessarily solely) to reduce their exposure to malpractice liability. Defensive […]
Defibrillation: The use of a carefully controlled electric shock, administered either through a device on the exterior of the chest wall or directly to the exposed heart muscle, to normalize the rhythm of the heart or restart it.
Defibrillator: A device that corrects an abnormal heart rhythm by delivering electrical shocks to restore a normal heartbeat.
- Defibrillator storm
Defibrillator storm: A condition that arises when a defibrillator implanted in the chest to right an arrhythmia (an abnormal heart rhythm) fires off frequently –sometimes several times a day or even more often — each time with a jolt like a boxer’s punch to the chest, because of far advanced heart disease. Defibrillator storm is […]
- Defibrillator, automated external
Defibrillator, automated external: See: Automated external defibrillator.