Parasitological, pathological and functional studies on the effects of IFN alpha 2b in murine hepatic schistosomiasis.

The effects of different doses of Interferon alpha 2b (IFN alpha 2b), alone and in combination with praziquantel (PZQ), on hepatic schistosomiasis were tested. An experimental murine model of hepatic schistosomiasis was used. Four parameters were assessed; hepatic fibrosis by estimation of OH-proline content/g dry weight liver, hepatocyte proliferative activity by the PCNA/LI, schistosomal egg load by digesting parts of the liver by KOH and hepatocyte function by measuring parenchymal liver enzyme levels. IFN alpha 2b was found to increase hepatic fibrosis in a dose dependent manner both alone and in combination with PZQ. An augmentation of the regenerative activity of the liver was observed. A reduction in the number of the granulomas and egg counts was observed only when PZQ was added. However, no effect on the size of the granulomas was observed apart from the normal process of modulation. Caution should be exercised when treating patients with concomitant hepatic schistosomiasis and hepatitis with IFN alpha 2b as it increases both hepatocyte regenerative activity and hepatic fibrosis; two main components of cirrhosis.

Autoclaved cercarial vaccine against schistosomiasis: ultrastructural and biochemical studies.

Autoclaved cercarial vaccine (ACV) was found to be highly effective in eliciting protective immunity against experimental Schistosomal mansoni. So, the aim of this study was to analyse ACV biochemically and to study ultrastructural changes inflicted on the cercariae as a result of autoclaving, thus rendering it highly protective. Results of this study showed that approximately 100 microg protein and 44 microg carbohydrate were obtained from 10(3) cercariae. The predominant sugar was fucose. Galactose, glucose, manose, galactosamine and glucosamine were also detected. Threonine, glycine, serine and glutamic acid comprised approximately 53.7% of the amino acid residues of the protein. Ultrastructural study revealed preserved architecture of the cercariae. The tails were still attached to the posterior ends of the bodies. However, in others the tails were separated from the bodies and appear schistosomula like. There were also some morphological changes such as thinning of the pericortical envelop with appearance of surface pores.