Schistosoma mansoni: the immune response against cercarial glycocalyx.

Schistosoma mansoni cercarial glycocalyx was separated and purified by Sephacryl-300 SR. It was found to stimulate the humoral immune response in mice injected with it. Antiglycoalyx antibodies raised in CD/1 mice were found to be cytotoxic to schistosomula in vitro. But conversely, no protective effect was demonstrated in vivo. Eosinophil-mediated cytotoxicity was found to have no effector function in the murine immune response against schistosomes. A monoclonal antiglycocalyx IgM was prepared during our study. It was found to have no cytotoxic effect on schistosomules in vitro. However, it was found to have an inhibitory activity blocking the cytotoxic effect of other antiglycocalyx isotypes in the immune mouse. The contradiction between the result of antiglycocalyx antibody-mediated cytotoxicity obtained in vivo and that obtained in vitro is in itself revealing and suggests that the effect is crucially dependent upon factors as yet poorly understood.

Study of free living amoebae in Egypt.

At different locality in Egypt, free living amoebae (FLA) were detected in 32%, 20% and 4% of water samples obtained from swimming pools, surface water canals and tap water respectively. Naegleria spp. were identified from 12 (75%) out of 16 swimming pool samples and 6 (60%) out of 10 surface water & canals samples from different Governorates in Egypt, while Acanthamoeba spp. were identified from 4 (25%) of 16 swimming pools samples, 4 (40%) out of 10 surface water & canals samples and 2 (100%) tap samples. The isolated FLA in the present study were non-pathogenic as proved by the pathogenicity test.

Study of human and parasitic factors in relation to bancroftian filariasis in Egypt.

The Human Leucocytic Antigen (HLA) and the histochemical reaction of microfilaria were studied by using cytotoxicity test and microfilarial acid phosphatase activity respectively to evaluate the role of the genetic factors and the parasitic factor in the pathogenesis of filariasis. Statistical significant association was found between HLA-B7 and the susceptibility for retaining microfilariae in blood and the development of clinical manifestations of filariasis. Histochemical study reported more or less the same results obtained in Egypt in elsewhere.

Leukaemogenic effect of toxoplasmosis and irradiation on albino rats.

The leukaemogenic effect of irradiation associated with toxoplasmosis was studied. Rats were infected with Toxoplasma gondii RH strain 3 weeks prior to irradiation. The leukaemic effect of irradiation was aggravated by toxoplasmosis as leukaemia appeared in 10% of 300 cGy irradiated rats and in 30% of 500 cGy irradiated ones, six months after irradiation.

Humoral and cellular immune response in schistosomiasis pre and post praziquantel therapy.

Humoral and cellular immune response in schistosomiasis was studied pre and post praziquantel therapy. After treatment the mean anti SEA IgM and IgG and anti SWAP IgM levels in all cases showed significant reduction. In patients with high eosinophilic count anti SEA IgE and IgA were statistically decreased. Other specific antibodies showed negligible changes Cellular immune response was not affected.

The effect of some drugs on acute toxoplasmosis in mice.

The effect of some chemotherapeutics, on the course of acute toxoplasmosis in experimentally infected mice was studied. Obtained results showed that, praziquantel, levamisole had no effect on acute toxoplasmosis, while trimethoprim-sulphamethoxazole and clindamycin showed some prophylactic effect on acute toxoplasmosis in mice.

Effect of ambient temperature changes on chronic toxoplasmosis in rats.

The effect of excess heat and cold on chronic toxoplasmosis was studied on rats. That was evident from the average increase in body weight, the effect on blood picture, deleterious effect of the pathology recorded in various organs, increased Toxoplasma brain cyst count, long persistence of parasites in the viscera, high antibody titre by I.H.A.T. in infected animals exposed to excess heat and its decrease in animals exposed to excess cold.

Effect of diet on experimental giardiasis.

Protein and fat deficiency diet produced significant reduction of Giardia cysts in rats, while vitamin A, D and iron deficiency diet had no effect on cyst count. On the other hand pathological changes due to Giardia infection encountered in small intestine and liver were aggravated by the diet deficiency induced.

Four methods in diagnosing protozoal parasites in stool.

Stool examination by 4 different methods showed that zinc sulphate floatation technique was more or less the best.