Schistosoma mansoni: a comparative study on two cercarial transformation methods
Hammouda, N.A.; Abou el Naga, I.F.; el Temsahi, M.M.; Sharaf, I.A.
Journal of the Egyptian Society of Parasitology 24(3): 479-486
1994
ISSN/ISBN: 1110-0583 PMID: 7844412 Document Number: 430399
An agar/gelatin plate method incorporating varying concentrations of linoleate was devised to measure cercarial penetration and transformation in vitro. Schistosoma mansoni cercariae were stimulated over a wide range of linoleate concentrations but the transformation process occurred over a narrow range. Penetration rates rose gradually until, at a linoleate concentration of 0.3 mM or greater, penetration reached approximately 100% and transformation began to occur. Transformation reached a maximum of 90% at 3.0 mM. This optimal concentration of linoleate was then compared with a mechanical transformation method in relation to proteolytic activity and nuclear content. It was found that proteolytic activity was higher with the chemical than with the mechanical method, and that the nuclear content decreased with both methods. The decrease in nuclear content was more marked using the mechanical method.