Schistosoma mansoni: the effect of dexamethasone on the cercaria-schistosomulum transformation, in vivo.

  title={Schistosoma mansoni: the effect of dexamethasone on the cercaria-schistosomulum transformation, in vivo.},
  author={A. L. de Melo and M. Hermeto and R. S. Bicalho and A. P. Vargas and F. Favaretto and L. H. Pereira},
  journal={Revista do Instituto de Medicina Tropical de Sao Paulo},
  volume={36 1},
Treatment with dexamethasone (DMS) in the early phases of the experimental Schistosoma mansoni infection causes an indirect effect on the cercaria-schistosomulum transformation process. This is observed when naive albino mice are treated with that drug (50 mg/Kg, subcutaneously) and infected intraperitoneally 01 hour later with about 500 S. mansoni cercariae (LE strain). An inhibition in the host cell adhesion to the larvae, with a simultaneous delay in the cercaria-schistosomulum… Expand
2 Citations
Exploring possibilities for an alternative approach in experimental schistosomiasis mansoni: the peritoneal cavity of mice
The constitution and evolution of these cellular reactions at histology were similar to that of hepatic granuloma, and peritoneal granulomata were subject to the host immunomodulation. Expand
Phenotypic plasticity of male Schistosoma mansoni from the peritoneal cavity and hepatic portal system of laboratory mice and hamsters
The present results reinforce the idea that S. mansoni has high plastic potential and adaptive capacity and significant morphometric alterations were observed when worms recovered from the portal system of both strains of mice were compared with the schistosomes obtained from hamsters. Expand


Kinetics of the cercaria-schistosomul um transformation in vivo: 2. The effect of oxamniquine
The results show that high doses of oxamniquine (given intramuscularly one hour before the infection) produce a marked delay in the kinetics of the cercaria-schistosomulum transformation. Expand
Kinetics of the pulmonary phase of Schistosoma mansoni in mice treated with dexamethasone.
Analysis of the results showed that the non-treated mice presented larger numbers of lung larvae than the treated ones, and this difference was also found later in the worm burden in the portal system. Expand
In vivo cercaria-schistosomulum transformation: inhibitory effect of oxamniquine.
High doses of oxamniquine (given intramuscularly) produced inhibition of cercaria-schistosomulum transformation following intraperitoneal injections of cerbariae into mice, suggesting the compound is active during the process of host-larvae adaptation. Expand
Kinetics of the cercaria-schistosomulum transformation in vivo
The inoculation ofcercariae into the peritoneal cavity of mice tofollow the steps involved in this progressive adaptation of cercarie to the vertebmte host, finding that most cercariae reach the schistosomular stage between 90-120 min after intraperitoneal inoculation. Expand
Studies on schistosomiasis. 14. Effects of cortisone upon the Schistosoma mansoni burden in mice.
It was found that essentially the same effect upon worm burden was produced whether the hormone was administered up to shortly before exposure to cercariae or commencing on the fifteenth day after infection when the parasites are in the liver or portal system. Expand
Retarded development of Schistosoma mansoni in immunosuppressed mice.
Indomethacin, a compound which inhibits tissue inflammatory reactions by inhibiting prostaglandin synthesis, and which therefore mimics one of the actions of corticosteroids, had no effect on S. mansoni worm maturation and fecundity. Expand
Differences between in vitro and in vivo obtained schistosomules.
The data on schistosomules obtained in vitro indicate that more than 24 hours are needed for complete remotion of molecules involved in the phenomenon of cell adhesion. Expand
Schistosoma mansoni: conversion of cercariae to schistosomula.
Abstract Schistosoma mansoni cercariae were injected directly into the peritoneal cavities of mice and the rate and extent of conversion of the cercariae to schistosomula was determined. TheExpand
Effect of Cortisone on Natural Immunity to Schistosoma mansoni in Mice
  • C. M. Coker
  • Biology, Medicine
  • Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine
  • 1957
The various regimens of cortisone treatment employed did not increase susceptibility to the parasite, as judged by numbers of adult worms recovered from hepatic portal tracts of the mice 7–8 weeks after infection. Expand
Schistosoma mansoni: generation of anaphylatoxin by cercarial extracts.
The activity formed by cercarial extracts produces cross-desensitization with the classical anaphylatoxin generated by agar, and induces mast cell degranulation in Guinea pig mesentery as well as enhancement of vascular permeability in guinea pig skin. Expand