Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunopathologic and morphologic studies at the light and transmission electron microscope levels were carried out in myocardial biopsies of 4 chagasic individuals with circulating antibodies reacting with plasma membrane of striated muscle and endothelial cells (EVI antibody). Two cases did not present clinical evidences of heart involvement, and 2 cases showed chronic heart disease. In viv deposits of immunoglobulins were found at the plasma membrane of working myocardial cells and endothelial cells. The cytologic location of the in vivo bound gamma-globulin was coincident with the specificity of the EVI antibody. Ultrastructural studies showed intracellular alterations compatible with hypoxia of the fibers; these lesions, although they were more severe in the 2 cases with heart disease, were also present in the asymptomatic individuals. These results are congruent with a possible pathogenic effect of the EVI antibody. In 2 patients with Chagas' heart disease, foci of mononuclear infiltrates were examined by transmission electron microscopy. At that level, a close relationship between lymphoctes and muscle cells was observed, with imbrication of the plasma membranes and disappearance of the basal laminae. In the neighborhood of the lymphocytes, definite muscle cell abnormalities were found. These observations are also congruent with the recently suggested possibility that a lymphocyte-mediated immune response against heart tissue may participate in some of the pathogenetic mechanisms of chronic chagasic cardiopathy.
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PMID:Chagasic cardiopathy. Immunopathologic and morphologic studies in myocardial biopsies. 40 15

An antibody reacting with the plasma membrane of working myocardial cells, skeletal muscle fibres, and endothelial cells (EVI antibody) has been described in the sera of patients with Chagas' disease. In the present study of rat isolated atrial preparations beating in ddifferent media, direct immunofluorescence and ultrastructural immunohistochemical procedures indicate that the antibody can interact with the living tissue, becoming fixed to the plasma membranes. Transmission electronmicroscopy studies also showed the presence of sarcolemmal alterations. These observations suggest a possible pathogenic effect of the EVI antibody. The presence of EVI-positive sera in the beating medium leads to a significant increase in the frequency of contractions; no significant effects of EVI-positive sera in contractile force were seen. The increase in frequency could be prevented by previous treatment with a b-adrenergic blocking agent (MJ-1999), but not by an x-blocker (phentolamine) or by an anti-histamine compound (cyproheptadine). The changes described were observed only in those atrial preparations which were beating in media containing EVI-positive sera. In those atria beating in control media (KR,KR plus normal human serum, KR plus EVI-negative chagasic serum), neither immunological nor morphological or functional changes wersence of EVI-positive chagasic serum diminished atrial stimulation after added norepinephrine. These results suggest the possibility that the EVI antibody may act as a b-adrenergic agonist at the cell plasma membrane level. Such an effect might account for some of the clinical features of chronic Chagas' heart disease.
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PMID:Effect of chagasic sera on the rat isolated atrial preparation: immunological, morphological and function aspects. 82 25

Serum samples from 150 individuals from an area in Brazil where Chagas's disease is endemic were examined for the presence of autoantibodies (EVI and PN). Patients were divided into four groups according to the diagnostic value and prognostic significance of electrocardiographic changes. Results confirmed a close relationship between the EVI and PN antibodies and chagasic infection but their presence does not appear to relate to the severity of Chagas's heart disease.
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PMID:Autoantibodies and chronic Chagas's heart disease. 703 19

The effects of chagasic sera, containing an antibody (EVI antibody) which reacts with the plasma membrane of working myocardial cells, on "toxic" and "non-toxic" actions of ouabain upon isolated self beating or paced rat atria suspended in different media, were explored. Although ouabain produced a dose-dependent positive inotropic influence on atria suspended in Krebs-Ringer-bicarbonate (KRB) and in KRB plus normal human serum (KRB + NHS) it did not elicit any significant positive inotropic effect on atria beating in KRB plus EVI positive human chagasic serum (EVI(+)S). Additionally, EVI(+)S dose-response curves of classical signs of digitalis cardiac toxicity shifted to the left. The threshold concentration of ouabain required to elicit the onset of "toxic" effects was higher in control preparations (kept in KRB or KRB + NHS) than in EVI(+)S exposed preparations. (-)-Propranolol attenuated the overall toxic action of ouabain in EVI(+)S and facilitated its positive inotropic influence. In control media, the beta-adrenoceptor blocker failed to modify either the "non-toxic" or the "toxic" effect of ouabain. On the other hand, with control atria, subthreshold exogenous norepinephrine inhibited the positive inotropism of ouabain. The data suggest that an adrenergic mechanism is involved in the action of ouabain on cardiac tissue immersed in an EVI(+)S-containing solution. The foregoing results may explain the severe "toxic" effects observed with cardioactive glycosides when they are used in patients with Chagas' heart disease, even at low doses.
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PMID:Chagasic sera alter the effects of ouabain on isolated rat atria. Participation of adrenergic mechanisms. 720 7