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Biomedical subjects

E Marchesini

Publications and source records attributed to E Marchesini.

5 recordsLinked to original sources
PubMed2004

Acute toxic effect of the algal yessotoxin on Purkinje cells from the cerebellum of Swiss CD1 mice.

Swiss CD1 mice died less than 2 h after intraperitoneal injection of 420 microg/kg of algal yessotoxin (YTX). The morphological, histochemical and immunocytochemical studies performed on the cerebellar cortex revealed damage to the Purkinje cells. The main cytological alterations were observed in the cytoplasm, while less sufferance was detected in the nucleus. The immunocytochemical experiments showed an increased positivity to S100 protein while there was a decreased response to calbindin D-28K, beta-tubulin and neurofilaments. These changes in intracellular Ca(2+)-binding proteins and the modifications in the cytoskeletal components of Purkinje cells suggest that YTX may be involved in neurological disorders.

Animals↗
PubMed2004

Lethal and sub-lethal yessotoxin dose-induced morpho-functional alterations in intraperitoneal injected Swiss CD1 mice.

Histological and immunocytochemical investigations were performed on different organs (brain, duodenum and thymus) of mice following lethal (420 microg/kg) or sublethal (10 microg/kg) intraperitoneal injection of yessotoxin (YTX). No morpho-functional modifications were observed in large neurons of the cerebral and cerebellar cortex with the sub-lethal dose, nor in the cerebral cortex with the lethal dose. The duodenum also did not show significant alterations. However, there was an inflammation response to the toxin, in which blood cells and cytokines were involved. This was more evident with the lethal YTX dose. The thymus and, in general, the immune system are the main targets of YTX at both the concentrations used. Furthermore, the alterations present in the thymus may support tumorigenic implications.

Analysis of Variance↗
PubMed2004

Corticosterone 21-acetate in vivo induces acute stress in chicken thymus: cell proliferation, apoptosis and cytokine responses.

In vivo effects of acute stress induced by corticosterone 21-acetate in male Gallus domesticus thymus are studied and the steroid actions are evaluated in terms of cell proliferation, apoptosis and cytokine response in 10- and 21-day-old chickens. Steroid treatment induced thymocyte apoptosis and cell death decreased in the cortical-medullar direction and was more evident in younger animals. 24 h after treatment, the observed effect was reversed. The mitotic activity and thymic cells containing cytokine-like molecules were also affected. Indeed, the acute stress stimulated cytokine immunoreactivity to anti-IL-1alpha, IL-6 and TNF-alpha antibodies both in epithelial cells and interdigitating cells located in medullar and cortical-medullar regions. The increased cytokine expression observed after 12 h was maintained after 24 h. The comparison between 10- and 21-day-old chickens showed a lower number of cells containing cytokine-like molecules in younger specimens. The present findings suggest that cytokines activated by acute stress in vivo could contribute to restoring immunological homeostasis and influence thymic glucocorticoid-mediated functions.

Animals↗
PubMedDate not supplied

Swiss mice CD1 fed on mussels contaminated by okadaic acid and yessotoxins: effects on thymus and spleen.

The toxicity of okadaic acid (OA) and yessotoxins (YTXs) was studied in mice orally fed on (i) OA (17.80+/-2.41 microg/kg) for 24 h and mouse feed for 24 h; (ii) OA (17.2+/-2.13 microg/kg) plus YTXs (1.30+/-0.12 mg/kg) for 24 h and mouse feed for 24 h; (iii) OA (18.88+/-1.86 microg/kg) plus YTXs (1.45+/-0.12 mg/kg) for 24 h. After toxin treatments the thymus and spleen were examined. More severe morpho-functional modifications were found in the thymus, which presented atrophy, a significant depletion in the lymphoid compartment and angiogenesis. In spite of the impairment, a number of inflammatory cells, reactive to anti-cytokine antibodies, were recruited. Moreover, greater expression of matrix metalloproteinase-9, particularly in cells located near new blood vessels, was observed. Thymus injury was still observed after 48 h. Histopathological changes to the spleen were more evident in mice orally treated for 24 h and immediately sacrificed. The organ showed a significant loss of volume and a fibrous component invaded regions involved in immune functions. In white pulp the marginal zones were reduced, lymphoid nodules contained large germinal centres and the periarteriolar lymphoid sheaths showed cellular depletion. An inflammatory cell response was activated by the recruitment of granulocytes, an increased number of active macrophages and increased immunoreactivity to cytokines. Unlike in the thymus, some evidence of recovery was seen in the spleen. The data suggest that low oral doses of OA alone or OA plus YTXs are able to provoke immunostimulation and systemic immunotoxicity, thus also indicative of tumorigenic properties.

Animal Feed↗