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Revista do Instituto de Medicina Tropical de São Paulo

On-line version ISSN 1678-9946

Rev. Inst. Med. trop. S. Paulo vol.31 no.1 São Paulo Jan./Feb. 1989 



Schistosoma mansoni: acquired resistance in mice by implantation of young irradiated worms into the portal system(1)


Schistosoma mansoni: resistência adquirida em camundongos pela implantação de vermes jovens irradiados no sistema porta



Paulo Marcos Z. CoelhoI; Rómulo Teixeira de MelloII; Carlos Alberto P. TavaresIII

IDepartamento de Parasitologia e Grupo Interdepartamental de Estudos sobre Esquistossomose (GIDE), ICB/UFMG. Caixa Postal 2486. CEP 30161 Belo Horizonte, MG, Brasil
IIDepartamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia da UFMG e Grupo Interdepartamental de Estudos sobre Esquistossomose (GIDE), ICB/UFMG, Belo Horizonte, MG, Brasil
IIIDepartamento de Bioquimica-Imunologia, ICB/UFMG, Belo Horizonte, MG, Brasil




In two distinct experiments, immature S. mansoni worms (LE strain, Belo Horizonte, Brazil), aged 20 days, obtained from the portal system of white outbred mice, were irradiated with 14 and 4 Krad, respectively. Afterwards, the worms were directly inoculated into the portal vein of normal mice. Inoculation was performed with 20 irradiated worms per animal. Fifty days after inoculation, the mice that received 4 and 14 Krad-irradiated worms and their respective controls were infected with S. mansoni cercariae (LE strain), by transcutaneous route. Twenty days after this challenge infection, the animals were sacrificed and perfused for mature irradiated (90-day-old) and immature (20-day-old) worm counts. Analysis of the results showed that statistically significant protection against cercariae occurred in both groups with irradiated worms.

Key words: Schistosoma mansoni - irradiated worms - immunoprotection - transplantation of worms.


Em dois experimentos distintos, vermes imaturos de Schistosoma mansoni, com 20 dias de idade, obtidos do sistema porta de camundongos albinos, foram irradiados com 14 e 4 Krad e posteriormente inoculados diretamente na veia porta de camundongos normais. Cada animal, de cada experimento específico, recebeu 20 vermes irradiados. Decorridos 50 dias de inoculação, os camundongos com os vermes irradiados com 4 e 14 Krad e seus respectivos controles foram infectados pela via transcutânea, com cercarias da cepa LE de Schistosoma mansoni. No 20º dia após esta infecção desafio, os camundongos foram sacrificados e perfundidos para as contagens dos vermes maduros irradiados (90 dias de idade) e imaturos (20 dias de idade).
A análise dos resultados mostrou que ocorreu proteção, estatisticamente significativa, contra cercarias nos grupos previamente inoculados com vermes irradiados com as doses de 4 e 14 Krad.



Texto completo disponível apenas em PDF.

Full text available only in PDF format.




The Authors gratefully acknowledge Mrs. Vera de Paula Ribeiro for translating the manuscript, and the technical assistance of Mr. Alberto Geraldo dos Santos, Mrs. Alice Neni Faria, Miss Zenir de Souza, Mr, José de Souza Filho, Mr. Adelino Ferreira and Mr. Maurício V. da Costa.



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Recebido para publicação em 06/6/1988.



(1) This work was supported, in part, by CNPq and PINEP, Brazil.

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