Ischemia


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ischemia

[i′skē·mē·ə]
(medicine)
Localized tissue anemia as a result of obstruction of the blood supply or to vasoconstriction.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Ischemia

 

a local deficiency of blood; insufficient blood in an organ or tissue because of the narrowing or complete occlusion of the lumen of an afferent artery.

Transitory ischemia (like hyperemia) may result from physiological regulation of the blood supply, such as in reflex spasm of an artery caused by a mental factor (fright); the influence of pain, cold, chemical substances (epinephrine, ergotin), and biological stimuli (bacteria, toxins); the obstruction of an artery by a thrombus or embolus; constriction of the lumen of a blood vessel in connection with an atherosclerotic or inflammatory process in the wall; or compression of an artery by a tumor, scar, or foreign body. The aftereffects of ischemia depend on the degree of disruption of the blood flow, the rate of development and duration of the ischemia, the sensitivity of the tissue to oxygen deficiency, and the general condition of the body. Ischemia may end in complete restoration of the structure and function of the affected organ or tissue, but it also may lead to necrosis (infarct). The central nervous system and heart muscle are particularly sensitive to ischemia.

N. R. PALEEV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
One treatment for critical limb ischemia is open surgery, in which a section of vein from the patient (or synthetic material) is used to bypass the blockage.
Current treatments are anti-VEGF injections into the eye, laser repair and vitrectomy, which are effective but do not address the underlying ischemia in the retina.
Afterwards, ischemia was induced by occlusion of the left anterior descending artery, close to its origin.
The activation of the PI3K/AKT pathway has been found to have a protective effect on ischemic BBB damage (12) and induces BBB permeability after cerebral ischemia (13).
Compared with men, women had twice as high a rate of MSIMI (22 versus 11 percent) and a similar elevation in ischemia with conventional stress (31 versus 16 percent).
Computed tomography has been heralded as the primary imaging for the evaluation of mesenteric ischemia. (2) The use of water as an oral contrast agent allows for improved visualization of the bowel wall and mucosa.
The product has reportedly been shown to accelerate the growth of new blood vessels to replenish blood supply to the limb, decrease symptoms and increase quality of life of patients suffering from Critical Limb Ischemia.
However, during ischemia the activity of the antioxidant enzymes is diminished, leading to an increase in the formation of superoxide radicals and oxidative stress at reperfusion [9].
HIR was induced 10 minutes after remifentanil administration with ischemia for 45 minutes and 120 minutes reperfusion.
Rats were randomly divided into four groups with 12 rats per group: sham-operated (S) group, liraglutide pretreatment normal blood glucose cerebral ischemia (NDM + MCAO + L) group, liraglutide pretreatment diabetes mellitus cerebral ischemia (DM + MCAO + L) group, and diabetes mellitus cerebral ischemia (DM + MCAO) group.
Unexpectedly, although CCD has been detected in patients with stroke, the in vivo imaging evaluation of this phenomenon in rodent models of cerebral ischemia has been never evaluated so far.