ABSTRACT
By employing 4-methylumbelliferyl-beta-D-NN',N"-triacetylchitotriose substrate in a semi quantitative assay, chitinolytic activity in viable spores of Encephalitozoon cuniculi and E. intestinalis was detected and dependence on reaction time, spore concentration, concentration of substrate and temperature were demonstrated. It was possible to block the chitinolytic activity by chitin hydrolysate. By incubation at 80§C for 10 min or at 55§C for 20 min the spores were loosing the chitinolytic activity. Incubation of the spores in trypsin reduced the chitinolytic activity. Cellulase activity could not be detected.
Subject(s)
Animals , Chitinases/metabolism , Encephalitozoon/enzymology , Cellulase/metabolism , Chitinases/antagonists & inhibitors , Spores/enzymology , Trypsin/pharmacologyABSTRACT
Granuloma proliferation is the result of a series of complex biological events in wich a variety of cell types and cytokines are involved. Tumor necrosis factor alpha (TNF-Ó) plays a central role. In the present study, we investigated the effect of thalidomide (Ó-N-pthalimidoglutarimide), a sective inhibitor of TNF-Ó synthesis, on granuloma formation during BCG infection in Oncins France 1 (OF-1) mice. Subcutaneous injections of 30 mg/kg body weight of thalidomide daily for 14,21 or 28 days into the mice resulted in the reduction of the size and total number of liver granulomas. The most strikinf effect of thalidomide was observed after 28 days, when the total number of liver granulomas was reduced by as much as 40 percent (P<0.05). Serum TNF-Ó levels of thalidomide-treatment mice were significantly lower (85 percent) than control mice on day 14 and remained lower...