Decreased expression of cardiac troponin C is associated with cardiac lesions in Amorimia exotropica poisoned cattle / Expressão diminuída de troponina cardíaca C associada com lesões cardíacas em bovinos intoxicados por Amorimia exotropica

The plants which cause sudden death of cattle in Brazil occupy a leading position for losses in the cattle industry. Amorimia exotropica is one of the plants pertaining to this group. Diagnostic findings in these cases may be inconclusive; further knowledge is necessary. This paper identifies cardiac lesions through anti-cardiac troponin C (cTnC) immunehistochemistry performed in tissues from cattle poisoned after consumption of A.exotropica in southern Brazil. Heart fragments from nine A. exotropica-poisoned cattle were studied immunohistochemically using anti-human cTnC as the primary antibody. In the hearts from all of the poisoned cattle, there was a sharp decrease in the cTnC expression level in the cytoplasm of groups of cardiomyocytes. A significant decrease in anti-cTnC immunoreactivity occurred particularly in degenerated or necrotic cardiomyocytes. Occasional groups of cells showed complete loss of immunolabeling. In the remaining intact cardiomyocytes from poisoned cattle and in cardiomyocytes from six cattle that died from other causes there was intense cytoplasmic staining.

No Brasil, plantas cujo consumo determina morte súbita de bovinos estão entre as principais causas de perdas na pecuária. Esse trabalho identifica lesões cardíacas através de imuno-histoquímica antitroponina cardíaca C (TncC), desenvolvida em tecidos de bovinos intoxicados após consumo de Amorimia exotropica, no sul do Brasil. Fragmentos cardíacos de nove bovinos intoxicados, naturalmente, por Amorimia exotropica foram examinados por imuno-histoquímica anti-TncC, como anticorpo primário. Nos corações de todos os bovinos intoxicados pela planta, havia pronunciada diminuição dos níveis de expressão de TncC no citoplasma de grupos de cardiomiócitos. Diminuição significativa na imunorreatividade anti-TncC ocorreu, particularmente, em cardiomiócitos degenerados ou necróticos. Grupos ocasionais de células mostraram completa perda de imunomarcação. Em cardiomiócitos remanescentes e intactos de bovinos intoxicados e em cardiomiócitos de seis bovinos que morreram por outras causas, observou-se intensa coloração citoplasmática.

In vitro cardiogenesis can be initiated in human CD34+ cells.

BACKGROUND: The extensive damage that occurs in the cardiac tissue after myocardial infarct is the major concern in post infarct management. It is very well known that adult stem cells mobilized by administration of G-CSF result in homing of stem cells into the damaged myocardium. This is because of the fact that stem cells have the ability to proliferate and capacity to generate into multiple cell lineages. METHOD: A healthy donor was selected as per the guidelines given by the institutional ethical committee and Helsinki declaration. The donor was given G-CSF 5 microg/kg/day and stem cells were harvested from the peripheral blood using Fresenius ASTec204 cell separator. The PBSC were then evaluated by immunohistochemical staining using anti-human CD34 monoclonal antibodies. The cells were then cultured in DMEM with 10% FCS for 17 weeks and in vitro cardiogenesis was initiated by adding 4 microM/l 5'Azacytidine. RESULTS: In vitro cardiogenesis was initiated in pure CD34+ cells with 5' Azacytidine. The cells showed spontaneous beating after 24 hours of treatment and after 5 weeks, the cells connected with the adjoining cells by a myotube. In these cells, expression of myosin light chain (MLC2v) gene and GATA-4 transcription factor validated the development of cardiomyocytes. CONCLUSION: It is observed that the transplantation of autologous stem cells/fetal cardiomyocytes in the heart scar tissue developed due to infarct, limited the scar expansion, and prevented post infarct heart failures. Homing process due to the transplantation of autologous stem cells is time consuming; therefore, transplantation of cardiomyocytes developed from autologous stem cells could be the future method of correcting the infracted myocardium.