The first finding of myxosporean development from plasmodia to spores in terrestrial mammals: Soricimyxum fegati gen. et sp. n. (Myxozoa) from Sorex araneus (Soricomorpha).

Soricimyxum fegati gen. et sp. n. is a new myxosporean (Myxozoa) species discovered in the liver of shrews, Sorex araneus L., collected in the Bialowieza primeval forest (Poland). Both developmental stages and mature spores were found during a histological study. The infection had about 40% prevalence at the investigated locality. Plasmodia were polysporic. Elongated plasmodia with an average size of 30 by 8 microm occupied bile ducts and larger rounded plasmodia up to 80 microm in diameter were found in liver parenchyma where they most probably entered after the ducts had been destructed. Plasmodia in both locations elicited a vigorous inflammatory reaction. Spores were of an ovoid shape, 7 microm long, 5.4 microm wide and about 3.5 microm thick. They had two shell valves and two equal polar capsules, located in opposite ends of the spore.

Liver and kidney structure and iron content in romanian brown bears (Ursus arctos) before and after hibernation.

The annual cycle of the brown bear (Ursus arctos) in the Carpathian Mountains (Romania) consists of an active period from April to November, and an inactive period (hibernation) of approximately 4-5 months between November and March. During hibernation, the brown bears sleep continually and do not feed or drink water. Analyses of liver and kidney of male brown bears showed that liver iron content was 3 times higher in bears at the end of hibernation than at the end of the active period. A possible trend towards a decrease in iron content was noted for the kidney. The presence of iron in the liver was confirmed by the presence of the Perls-positive granules in the cytoplasm of Kupffer cells, in other non-parenchymal cells and also in some hepatocytes. The hepatic veins of the bear liver samples obtained in early spring showed narrower lumens with pleated walls, compared to the normal outline of the hepatic veins in the liver from the bears sampled during autumn. Also in the early spring bears, the renal glomeruli were partially fibrosed. Renal glomerular fibrosis was sometimes observed in samples from the prehibernation period. The tissue iron values from the livers and kidneys of brown bears in early spring or autumn might provide useful data on iron metabolism under conditions of hibernation and accompanying starvation.

Liver histological structure in adult European bison. Bison bonasus (Linnaeus, 1758).

The histological structure of the liver in 12 European bison, 2-8 years old, was presented. The study of the hepatic lobule showed that in Bison bonasus there were no connective septa around the hepatic lobules. On the hepatic lobule territory, solitary bile ducts, respectively solitary arterioles, were sometimes observed. Every one of these vessels was isolated from the hepatic parenchyma by thick coats of collagen. In the adventitia of the hepatic sublobar vessels, capillaries of the vasa vasorum system were found. The thick capsule of Glisson presented an outer part lacking in blood vessels and an inner part vascularised with arterioles and capillaries originating from the subcapsular portal tracts. The ligament insertion in the liver parenchyma was described.