A trial to enhance the efficiency of Cyclosporin A in the treatment of Schistosoma mansoni infection by immunization of mice.

Cyclosporin A (CsA) acts in two distinct modes against Schistosoma mansoni (S. mansoni) infection. It behaves in part as an antihelminthic and also as an immunomodulator. In this study, two methods were performed to increase the efficacy of the subcurative dose of CsA (30 mg/kg). These methods were, passive immunization where the drug was given simultaneously with rabbit antisera post infection and active immunization where the worm surface antigen was given prior to infection. The results showed that both methods led to enhancement of the curative effect of the CsA. However, the active immunization gave more significant reduction in liver worm and egg loads. Histopathological study showed small size and few number of hepatic granulomas in the passively immunized group while in the active group, there was just few and small collection of inflammatory cells. Moreover, the indirect fluorescent antibody test visualized damage to the worm tegument in both types of immunization. Thus, it could be concluded that active immunization increased the immunomodulatory effect of CsA in treatment of S. mansoni with less toxic effects by using a subcurative dose.

Detection of Trichinella pseudospiralis antigen in the parenteral phase in experimentally infected mice.

Antigen distribution of T. pseudospiralis in muscles was studied at 10 days, 2,3 and 5 weeks post infection. Immunocytolocalization of antigen in the muscle was performed by peroxidase antiperoxidase (PAP) and immunogold silver staining techniques. Weak positive reaction of the stichosome and the cuticle was observed at 10 days post-infection which increased to attain its highest level in the fully infective stage larvae 3 and 5 weeks post infection. The intensity of staining reaction in the cytoplasm and nucleoplasm of infected host cell and surrounding tissue was highest at 5 weeks p.i. The small nuclei of the host cells and the inflammatory cells were unstained.

Detection of Trichinella pseudospiralis antigen in the enteral phase in experimentally infected mice.

The distribution of T. pseudospiralis antigen in tissue sections of the intestine of infected mice was studied at different intervals (10, 21, 35 hours and 10 days post-infection (P.I.). Immunocytolocalization of antigen in the intestine was done by peroxidase antiperoxidase staining technique. Positive staining reaction of the enterocytes was noted in all durations examined. The mononuclear cells of the lamina propria were positively stained at 10 hrs P.I. while patchy staining of muscularis mucosa was observed at 10 days P.I. The present study revealed intense staining reaction in the stichosome and the cuticle of 10 hrs-old larvae L1, the intensity of the reaction decreased throughout the worm development, until it almost disappeared at 10 days P.I. The gut lining and its occupying substance were positive throughout the enteral phase. Intense staining reaction of the hypodermal cells was observed in L2, L3 and adult stage worm. The genital primordium was weakly stained in the larval stages while the male and female reproductive systems were moderately stained at the adult stage.