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(shă-gō′mă) A painful, red swollen lesion found at the site of inoculation of the parasite Trypanosoma into the skin. SEE: trypanosomiasis, South American.


(chān) [Fr. chaine, fr L. catena, chain] 1. A related series of events or things. 2. In bacteriology, bacterial organisms strung together. 3. In chemistry, the linkage of atoms in a straight line or in a circle or a ring. The ring or straight-line structures may have side chains that branch off from the main compound.

cold c. A temperature-controlled supply system to ensure or extend the shelf life of products such as fresh produce, frozen food, photographic film, chemicals, drugs, and/or vaccines.

c. of custody A verifiable procedure that tracks the movement and location of physical evidence, e.g., medical samples taken during a rape examination, through its shipping, handling, and processing at a clinical laboratory until it is presented in court. SEE: rape.

electron transport c. The stage of cellular respiration in which the most adenosine triphosphate is generated. In this biochemical reaction, electrons are passed along the cytochromes of a cell or mitochondrial membrane and are ultimately accepted by oxygen, producing water. Hydrogen ions (protons) are transported across the membrane. The source of the protons and electrons is primarily nicotinamide adenine dinucleotide, which is recycled during the reaction. SYN: cytochrome transport system.

error c. A series of connected events ultimately resulting in an adverse patient outcome.

food c. The transfer of food energy from producers (green plants) to primary consumers (herbivores) to secondary consumers (carnivores). Dead organisms of all kinds are reduced to simpler chemicals by decomposers (bacteria and fungi), which make minerals available again for green plants.

heavy c. The large polypeptide chains of antibodies. SEE: heavy chain disease.

J c. The joining portion of a polymeric immunoglobulin, found in dimeric and polymeric IgA and pentameric IgM.

kinematic c., kinetic c. A series of bones connected by joints. Movement of one segment influences other parts of the chain.

light c. The small polypeptide chains of antibodies, i.e., their kappa or lambda chains.

c. of survival In emergency cardiac care, the notion that the survival of patients in cardiac arrest depends on the linkage of the following: 1) immediate recognition and activation, 2) early cardiopulmonary resuscitation (CPR), 3) rapid defibrillation, 4) effective advanced life support, and 5) integrated postcardiac arrest care. If for any reason any one of these links is missing or delayed, the chance of survival decreases considerably. SEE: cardiopulmonary resuscitation.

chain reaction

A self-renewing reaction in which the initial stage triggers a subsequent reaction, which in turn causes the next, and ...

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