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Biomedical subjects

M Pavan

Publications and source records attributed to M Pavan.

33 records · Page 2Linked to original sources
PubMed1991

Paederus fuscipes dermatitis. A histopathological study.

Paederus fuscipes (PF) dermatitis is a self-healing blistering disorder of the skin caused by a small insect belonging to genus Paederus, family Staphylinidae, order Coleoptera. Crushing PF on the skin causes acute dermatitis within 24 hours, corresponding in shape and dimensions to the area affected by the substance released (pederin). The acute vesicular lesions become crusted and scaly within a few days and heal completely in 10-12 days, with a transitory postinflammatory hypercromic patch. Twenty consecutive cases of PF dermatitis at different stages were studied histologically by routine light microscopy. The pederin causes a spectrum of histopathologic changes ranging from acute epidermal necrosis and blistering in acute stages, to marked acanthosis with mitotic figures in the late stages. PF dermatitis is an entomological model of irritant contact dermatitis, having histopathologic features of intraepidermal and subepidermal blistering, epidermal necrosis and acantholysis. The presence of some acantholytic foci, relatively far from the foci of clinically involved skin, in four of the cases considered suggests a possible role of pederin in inducing acantholysis indirectly. Acantholysis is probably caused by the release of epidermal proteases.

Animals↗
PubMed1988

Visceral obesity and diabetes.

The cross-sectional subcutaneous and visceral areas of adipose tissue, measured on computed tomographic scans at abdominal level and the subcutaneous/visceral fat area ratio (S/V ratio) distribution have been calculated in 155 subjects. Using the S/V ratio as discriminator, two groups of patients of both sexes, with subcutaneous or visceral type of obesity have been selected. Metabolic studies demonstrate a significant reduction of glucose tolerance at the oral glucose load and a significant increase of the insulin response in patients with visceral obesity. The size of the omental fat cells was larger in visceral obesity, while the size of subcutaneous fat cells was larger in subcutaneous obesity. A significant correlation was found between the S/V area ratios and the subcutaneous/visceral fat cell weight ratios. In vitro studies on subcutaneous and omental fat obtained during surgery from 9 patients with subcutaneous obesity and 7 patients with visceral obesity demonstrate a significantly higher isoprenaline-stimulated lipolytic response in omental fat of patients with visceral obesity. The lipoprotein lipase activity in subcutaneous fat was higher than in omental fat in both types of obesity.

Adipose Tissue↗
PubMed1968

Studies on the mechanism of action of pederine.

Pederine, a drug extracted from the coleopter Paederus fuscipes, inhibits the growth of in vitro cultured cell lines at concentrations of the order of 1.5 nanogram/ml. Cytological examination shows a generalized cytotoxic effect. Analysis of macromolecular syntheses by the use of radioactive precursors shows that pederine causes an almost immediate block of protein and DNA synthesis, without affecting RNA synthesis. The effects on the synthesis of the two types of macromolecules remain nearly simultaneous even at the lowest active concentrations of pederine. Studies with cell-free systems show that the drug inhibits protein synthesis, whereas it is ineffective on the DNA-polymerizing activity. It seems, therefore, that the drug acts primarily on the amino acid-polymerizing system, and that the effect on DNA is secondary. This idea is strengthened by the observation that puromycin, a specific inhibitor of protein synthesis, also affects promptly DNA synthesis of in vitro cultured cells. Other authors have shown the same phenomenon with a number of inhibitors of protein synthesis; the properties of pederine support, therefore, the view that continuous protein synthesis is necessary for the maintenance of DNA replication in higher organisms.

Animals↗
PubMedDate not supplied

[Lipolytic and lipoprotein lipase activity of subcutaneous and visceral adipose tissue in Cushing's syndrome].

Cushing's syndrome has been recently compared to visceral-type obesity, since it is characterised by the accumulation of adipose tissue at a deep abdominal site, to the detriment of the subcutaneous adipose panniculus, and is associated with insulin-resistance and hyperlipemia. The aim of the present study was to evaluate the influence of glucocorticoid hormones on lipolytic activity (index of FFA mobilisation) and on lipoproteinlipase (LPL) activity (an index of the accumulation of triglycerides) in subcutaneous and perirenal adipose tissue in order to clarify the mechanisms involved in this type of accumulation in Cushing's syndrome. Five patients (4 F and 1 M) were included in the study, mean age 27.8 +/- 3.7 years and BMI 21.3 +/- 1.2 kg/m2; patients were hospitalised in the 2nd Surgical Clinic at the University of Padua and underwent surgery for secondary corticosurrenal hyperplasia with ACTH secreting hypophysial adenoma. Lipolytic activity in subcutaneous adipose tissue in these patients was significantly lower (p less than 0.05) than in control subjects, in particular after noradrenalin stimulation (p less than 0.01). No significant difference was observed when lipolytic activity in subcutaneous adipose tissue was compared to that one in perirenal tissue. LPL activity in subcutaneous adipose tissue did not reveal statistically significant differences compared to control subjects, although values were lower. A further decrease in LPL activity, which was not however significant, was observed in perirenal tissue in comparison to subcutaneous tissues in the same patients. The mean weight of adipocytes (ug) was slightly lower in subcutaneous adipose tissue compared to control subjects and even lower in perineal tissue in comparison to the subcutis in the same patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMedDate not supplied

[Helicobacter pylori infection as a cause of recurrent abdominal pain in children].

Several reports indicate that Helicobacter pylori plays a role in recurrent abdominal pain in children and adolescents. The aim of our study is to determine the prevalence of H. pylori among Verona children with and without recurrent abdominal pain. 309 patients were tested for the presence of anti-H. pylori IgG in a blood sample. Among 43 children with recurrent abdominal pain, the prevalence of H. pylori infection was 25.58%, while the prevalence of H. pylori infection in children without abdominal symptoms was 4.88%. Sensitivity and specificity of serology were respectively 81.8% and 87.5%. We conclude that endoscopic examination cannot be replaced by serological test.

Abdominal Pain↗