Natural trematode infestation in feral Nebrodi Black pigs: pathological investigations.

Few studies describe the parasites of pigs bred in the wild state, although pigs are a known reservoir of trematode infestation. This article reports the results of a retrospective study carried out from January 2003 to June 2007 on 3021 Nebrodi Black male and female pigs, regularly slaughtered, aged between 8 months and 4 years. Fasciola hepatica and Dicrocoelium dendriticum flukes were detected in 143 (4.37%) of 3021 livers. The predominant histological features were multifocal to diffuse chronic hepatitis, with fibrosis and severely thickened walls of the bile ducts and chronic parietal, sometimes nodular inflammation. F. hepatica infestation was frequently associated with marked hyperplasia and hypertrophy of the submucosal glands. The study results confirm the important role swine play in the transmission of trematode infestations, indicate the prevalence of these parasites in the Nebrodi Park area, and draw attention to the need for a prophylaxis plan to prevent the spread of infestation to ruminants and humans living in the area.

Enzymatic changes in mitochondria-rich cells of Xenopus laevis skin epithelium are induced by ionic acclimation.

Morphological, biochemical and histochemical components of mitochondria-rich (MR) cells of skin epithelium of Xenopus laevis (Daudin) were investigated after acclimation in distilled water (DW) and mild solutions (50 mmol/l) of either NaCl or KCl for over 10 days. The animals readily acclimated to NaCl, but approximately 50% of the animals died in the KCl solution. Electrophysiological measurements confirmed the poor transport properties of skin in all conditions. Silver staining and exposure to methylene blue (MB) have shown that two types of MR cells can be distinguished, especially after KCl acclimation. Immunohistochemistry with the use of anti-band 3 polyclonal and anti H+-ATPase monoclonal antibodies demonstrated that band 3 and H+-ATPase enzymes were localized in MR cells in all conditions. H+-ATPase was greatly reduced during NaCl acclimation as verified with SDS gel electrophoresis. Intensity of the immunohistochemical staining differed between the various conditions of acclimation. Histochemical localization of carbonic anhydrase and alkaline phosphatase activities was more intense during NaCl acclimation. Morphological changes were also observed between the various acclimation conditions. The present findings substantiate the existence of at least two forms of MR cells in Xenopus skin epithelium but their functional significance remains to be established.