The sum total of body mechanisms which interpose barriers to the progress of invasion or multiplication of infectious agents, or to damage by their toxic products. 1. Immunity - That resistance usually associated with possession of antibodies having a specific action on the microorganism concerned with a particular infectious disease or on its toxin. Passive immunity is attained either naturally, by maternal transfer, or artificially, by inoculation of specific protective antibodies (convalescent or immune serum or immune serum (gamma) globulin (human) and is of brief duration (days to months). Active immunity lasting months to years is attained either naturally, by infection, with or without clinical manifestations, or artificially, byinoculation of fractions or products of the infectious agent or of the agent itself, in killed, modified or variant form. 2. Inherent resistance - An ability to resist disease independently of antibodies or of specifically developed tissue response; it commonly rests in anatomic or physiologic characteristics of the host; it may be genetic or acquired, permanent or temporary.
A person or other living animal that affords subsistence or lodgement to an infectious agent under natural conditions; in an epidemiologic context, the host may be the population or group, or biological, social and behavioural characteristics of the group.... host
A condition that is a common complication of BONE MARROW transplant (see TRANSPLANTATION). It results from certain LYMPHOCYTES in the transplanted marrow attacking the transplant recipient’s tissues, which they identify as ‘foreign’. GVHD may appear soon after a transplant or develop several months later. The condition, which is fatal in about a third of victims, may be prevented by immunosuppressant drugs such as ciclosporin.... graft versus host disease (gvhd)
measurement of the resistance of the cervix during the passage of a series of metal (Hegar) dilators. Lack of resistance in a nonpregnant women may suggest cervical weakness when she has experienced a previous second-trimester pregnancy loss or if she has had previous surgery to the cervix, and may indicate *cervical cerclage in the event of future pregnancies.... cervical resistance index
diminution in the response of the body’s tissues to insulin, so that higher concentrations of serum insulin are required to maintain normal circulating glucose levels. Eventually the islet cells can no longer produce adequate amounts of insulin for effective glucose lowering, resulting in hyperglycaemia. Insulin resistance is one of the risk factors for cardiovascular disease. See also diabetes mellitus; metabolic syndrome.... insulin resistance
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