Migratory effects on the body surface of Angiostrongylus cantonensis from subarachnoid space to pulmonary artery in rats.

Juvenile worms of Angiostrongylus cantonensis recovered from subarachnoid spaces and pulmonary arteries of rats, respectively, at 28 days post-infection have been compared with respect to their surface composition, antigenicity of surface proteins and morphological appearance. Quantitative and qualitative differences were shown between surface proteins of these two stages of worms. One major and 6 minor proteins appeared on brain stage worm's surface as assessed by surface-labelling and SDS-PAGE techniques. The same, but more predominant banding pattern, with one additional major protein of Mr 80,000 kDa presented on the lung stage worm's surface. Surface components from both stages were antigenic in permissive rat hosts but refractory in nonpermissive human hosts. The surface antigens are common to both stages within the rat. Observed by scanning electron microscopy, the surface appearance of brain stage worms is thickened, rough and irregular. Besides, particle clusters adhere randomly, without cluster adherence but transverse and longitudinal clefts were shown on the surface, before the outer layer was shed. The possible mechanisms of evasion from the host's immune attack with the surface-shedding phenomenon remain to be elucidated.

Immunodiagnosis of clonorchiasis by enzyme-linked immunosorbent assay.

The present study applied the indirect enzyme-linked immunosorbent assay (ELISA) technique in the immunodiagnosis of clonorchiasis. Antigen used in this study was extracted from adult worms of Clonorchis sinensis obtained from cats. 132 patients with clonorchiasis, 100 healthy persons and 14 patients with other parasitic infections were studied. Mean O.D. ratio with standard deviation of clonorchiasis was 1.41 +/- 0.21 with 0.95 +/- 0.13 of healthy persons. Results revealed 90.2% to 95.5% of sensitivity and 84% to 99% specificity dependent on the two cut off values of O.D. ratio, i.e. 1.10 and 1.20. Antibody titers derived from O.D. ratio highly correlated with direct titration (Y = 0.0303 +/- 1.1766 X, r = 0.8945). Cross reactions of other parasite infections to clonorchiasis were observed in patients with angiostrongyliasis and schistosomiasis.

Glycolytic enzymes in juvenile and adult Angiostrongylus cantonensis.

In extracts of adult Angiostrongylus cantonensis, the activities of enzymes including glucokinase, phosphoglucoisomerase, phosphofructokinase, aldolase, triosepho sphate isomerase, glyceraldehydephosphate dehydrogenase, phosphoglycerokinase, phosphoglyceromutase, enolase, pyruvate kinase, lactate dehydrogenase, pyruvate decarboxylase, alcohol dehydrogenase, glucose 6-phosphate dehydrogenase, glycerophosphate dehydrogenase and pyruvate dehydrogenase complex were demonstrated. The present of significant activity of glycerophosphate dehydrogenase and glucose 6-phosphate dehydrogenase may indicate the possibility of an operative of alpha-glycerophosphate and pentose phosphate pathway.