Accession Number : ADA019670

Title :   Mechanisms of Skin Penetration by Schistosoma Mansoni Cercariae.

Descriptive Note : Annual progress rept. 1975-1976,


Personal Author(s) : Dresden,Marc H.

Report Date : JAN 1976

Pagination or Media Count : 11

Abstract : This report describes progress made in studies of the mechanisms by which cercariae of the human parasite, Schistosoma mansoni, penetrate the skin of vertebrate hosts. The penetration processes are mediated by secretion of proteolytic enzymes from the preacetabular glands of the cercariae. Studies on the biochemical characterization of these enzymes are reported, and it is concluded that these enzymes are unrelated to trypsins or elastases, but do resemble vertebrate chrmotrypsins and/or bacterial subtilisins. Protease activity is inhibited by vertebrate (including human) sera and it is concluded that the major inhibitory component is alpha-1-antitrypsin. The preacetabular glands also contain calcium and the localization and quantitation of the calcium content of these glands has been reported. The effects of zinc in killing cercariae have been described, and open new avenues for control of the disease. Studies on the effect of the proteases on the cercarial glycocalyx are also described, and it is concluded that these enzymes are not involved in cercarial transformation.

Descriptors :   *Schistosoma mansoni, Penetration, Skin(Anatomy), Cercariae, Enzymes, Chymotrypsin, Blood serum, Calcium, Zinc, Parasitic diseases, Control, Inhibitors, Gamma globulin, Infections, Surfaces, Schistosomiasis, Humans, In vitro analysis

Subject Categories : Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE