Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cardiac function of dialysis patients improves when severe anemia is corrected with Epoetin alfa. Direct clinical changes include a decrease in cardiothoracic ratio and diminished left ventricular size. Exercise-induced cardiac ischemia as noted by depression of the S-T segment on EKG is also reduced. Nephrology nurses must monitor hemodynamic changes, provide patient reeducation, and encourage patient compliance with medication regimens.
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PMID:Case management of the anemic patient. Focus on hemodynamics. 206 57

With the technique of laser-Doppler velocimetry, cutaneous blood flows in the forearm of patients with stable sickle cell disease after graded periods of proximal ischemia were compared with normal subjects matched for age, race, and sex, and with patients with anemia caused by beta(+)-thalassemia. In the sickle cell patients the reactive hyperemia was characterized by an increased time interval between the release of the occlusion and the peak amplitude response (time-to-peak) and by a greater period of blood flow above the base-line value (payback ratio) compared with controls. In addition, prolongation of the occlusion period led to an augmentation in the magnitude of the characteristic basal flow oscillations or an induction of this phenomenon at sites not exhibiting it before ischemia. Base-line or ischemia-provoked flow oscillations of either this magnitude or frequency were only observed in normal or thalassemic controls during brief intervals in the rapidly decaying portion of the hyperemic response and in one subject with homozygous hemoglobin C disease. These results would support a model of a local integrative control of microcirculatory blood flow, which appears to become augmented, synchronized, and sustained in sickle cell subjects.
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PMID:Microcirculatory adaptations in sickle cell anemia: reactive hyperemia response. 240 12

Terminal complement complex (TCC) and anaphylatoxin formation in 18 patients with sepsis and 20 patients with acute limb ischemia were studied before the start of treatment and seven days later. The septic or ischemic patients had elevated levels of plasma TCC before start of therapy. In successfully treated patients these concentrations were within the normal range one week later. Similarly, the plasma anaphylatoxin level was increased before therapy and returned to the normal range within seven days. Escherichia coli incubated in vitro in fresh human serum at body temperature started formation of TCC in a dose-related manner. As complement will induce cellular lysis via TCC and edema via anaphylatoxins, anemia and impaired respiration in these patients may be influenced by increased concentrations of terminal complement complexes and of C3a and C5a.
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PMID:Terminal complement complexes and anaphylatoxins in septic and ischemic patients. 327 84

The current status of superoxide dismutase (SOD) is that it is an enzyme with diverse ramifications. This review attempts an understanding of SOD as a structural, functional, and biological entity. Accordingly, the review is in three parts. The first part discusses SOD in terms of protein structure, proceeding from primary to secondary and three-dimensional structure for the three forms of SOD: copper/zinc SOD, manganese SOD, and iron SOD. This is the order of structural knowledge of the enzyme. Iron SOD is an enzyme of prokaryotes and some higher plants. Manganese SOD is an enzyme of prokaryotes and eukaryotes. Copper/zinc SOD is an enzyme of eukaryotes and certain prokaryotes. The evolutionary relationships of the three forms of SOD, the status of the copper/zinc SOD gene in prokaryotes, and the cloning and sequencing of SOD genes are discussed. The second part of the review deals with the catalytic mechanism of SOD in the three forms of the enzyme. Structural and mechanistic conclusions from various spectroscopic studies are critically considered. A detailed picture is given of the active site of copper/zinc SOD. The third part is a review of SOD in the general context of oxygen toxicity. After consideration of the question of superoxide toxicity and superoxide pathology, several areas in which SOD has been investigated or used as a tool in a biochemical, pharmacological, or clinical context are discussed, including population genetics; trisomy 21; development and senescence; the nutritional copper, zinc, and manganese status; hemolysis and anemia; oxygen toxicity in the lung and nervous system; inflammation, autoimmune disease and chromosome breakage, ischemia and degenerative changes; radiation damage; and malignancy. A comprehensive picture is given of measurements of SOD activity in disease states, and the question of superoxide-related disease is considered at several points.
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PMID:Aspects of the structure, function, and applications of superoxide dismutase. 331 61

This review describes the transport of oxygen from ambient air to mitochondria in the cells. Using simple equations and diagrams, the presentation illustrates the variables which determine the magnitude of each of the three major steps in the partial pressure of O2 along the passage, from: (i) ambient air to alveolar gas; (ii) arterial blood to venous blood; and (iii) capillary blood to tissue. The emphasis is on steps (ii) and (iii), and how they are modified from the normoxic case by ischemia, anemia, hypoxia, and increased VO2. The basic context of step (iii) is the Krogh model. This model, despite its limitations, is proposed as conceptually useful in analyzing whole-body or tissue O2 transport.
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PMID:A pictographic essay on blood and tissue oxygen transport. 338 98

Anemia in runners is common but its origin is unknown. The present study reports on frequency and origin of gastrointestinal blood loss in cross-country skiers and runners. 41 participants in the Engadin Ski Marathon were checked by questionnaire and occult blood test. 8 (19%) had diarrhea or abdominal pain during or immediately after skiing and 3 (7%) had hemoccult-positive stools. In addition, the blood flow of the superior mesenteric artery was measured by duplex scanning in two trained runners after standardized exercise. While the mesenteric blood flow in the asymptomatic runner changed only insignificantly there was an impressive decrease in the second runner, who had been treated for anemia, down to 20% and 40% (30 and 90 min respectively) after exercise. It is concluded that the occurrence of gastrointestinal blood loss in cross-country skiing, and the significant decrease in mesenteric blood flow in a symptomatic runner, indicate a close and possible causal relationship between mesenteric ischemia and "jogging anemia".
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PMID:[Mesenterial anemia as a cause of jogging anemia?]. 376 81

The possible methods of preventing myocardial infarction have been discussed. The desirability of prevention in the total problem of myocardial infarction is stressed. The methods consist of the prevention of the underlying coronary atherosclerosis, and the secondary prevention of myocardial ischemia contributed by other factors than those presumed to relate to atherosclerosis. In the primary prevention of coronary atherosclerosis the two major risk factors are elevation of serum lipids and of blood pressure. The benefits to be achieved by reduction of elevation of both of these abnormalities are discussed. Both require a long-term approach starting as early in life as possible. The major methods of prevention or retardation of coronary ischemia irrespective of coronary artery disease involve discontinuance of cigarette-smoking and a program of increased physical activity. In addition, prevention or correction of polycythemia, anemia or hypercoagulability should be included. The use of oxygen, in higher percentage or at higher pressure than in the atmosphere, surgical intervention to improve the myocardial blood supply and pharmacologic agents to improve myocardial metabolism are also considered. Quantitation of the benefit of preventive programs is still impossible. Benefit from lowering blood lipids and blood pressure requires long-term therapy begun early in life. Discontinuance of cigarette smoking and increasing the amount of physical activity offer reasonable assurance of immediate benefit. So also does correction of hematologic abnormalities. Pharmacologic agents and surgery to improve coronary blood flow still require further evaluation.
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PMID:Prevention of myocardial infarction. 521 90

The selective embolization with fibrin sponge has controlled the persistent hematuria subsequent to a great renal arteriovenous post-operative fistula whereby the kidney recovered immediately after the embolization its normal functioning. A control arteriograph realized six weeks later showed the recanalization of the vessels, without any evidence of fistula. In another case, the renal massive hematuria after a percutaneous renal biopsy which produced a state of acute anemia was treated with the same method. The angiographic control showed the disappearance of the fistula, with a small ischemia zone distant from the embolized zone.
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PMID:[Treatment of renal arteriovenous fistula by means of embolization using a fibrin sponge]. 615 86

We examined whether submaximal treadmill exercise during acute isovolumic anemia altered the distribution of myocardial blood flow and thus caused subendocardial ischemia in unsedated dogs. Myocardial blood flow (determined by the microsphere method) and left ventricular function (indicated by pressures, volumes, and contractile indices) were measured in five dogs at rest and during exercise before and after equal volume exchange of blood and 6% dextran 70, which lowered hematocrit from 36 +/- 4 to 18 +/- 2% (SD). Total myocardial blood flow increased from 175 +/- 65 to 296 +/- 151 ml . min-1 . 100 g-1 (69%) during exercise before anemia and from 329 +/- 61 to 599 +/- 126 (82%) during exercise after anemia. The distribution of blood flow to the left and right ventricles and interventricular septum as well as the subendothelial-to-subepicardial blood flow ratio in these areas did not change during exercise either before or after anemia. Left ventricular function was not impaired during exercise after anemia. We conclude that subendocardial ischemia does not occur when dogs exercise during acute isovolumic anemia.
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PMID:Myocardial blood flow during acute isovolumic anemia and treadmill exercise in dogs. 618 Oct 44

Cardiac performance was studied by radionuclide angiography at rest and during exercise in 22 adolescents with sickle cell (SC) anemia and the results were compared with those in 12 control subjects. At rest, cardiac contractility was normal; cardiac output and end-diastolic volume were increased. At maximal exercise, heart rate, cardiac output response, and work capacity were reduced; the reduction was related to the degree of anemia. Left ventricular end-diastolic volume decreased with exercise most markedly in patients with ischemic exercise electrocardiograms. An abnormal ejection fraction response to exercise occurred in 4 patients; electrocardiographic signs of ischemia developed in all 4, and wall motion abnormalities in 2. Those patients who had electrocardiographic signs of ischemia had a significantly lower heart rate, ejection fraction, and cardiac output response to exercise, and a lower hematocrit level than subjects with normal results on exercise electrocardiography. The increase in cardiac output was not sufficient to maintain a normal level of exercise. The decrease in end-diastolic volume suggests that diastolic function was abnormal during exercise. Cardiac dysfunction was manifested by an abnormal ejection fraction response, wall motion abnormalities, and incomplete left ventricular filling during exercise.
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PMID:Exercise-induced cardiac dysfunction in sickle cell anemia. A radionuclide study. 621 49


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