Synthesis of new uracil-5-sulphonamide-p-phenyl derivatives and their effect on Biomphalaria alexandrina snail's nucleoproteins.

In continuation of the previous work (Fathalla, 1992) on the synthesis of some heterocycles containing uracil moiety, we report herein the incorporation of uracil moiety into cyanopyridine thione, thiosemecarbazone, semicarbazone, cyanopyridine, aminocyano pyridine, isoxazoline, pyrazoline, pyrimidine, triazolo pyrimidine, pyran, selena and thiazole derivatives which might modify their biological activities. The biological studies revealed that the chemical compound III f showed high molluscicdal activity than other compounds. The profile of the nucleoprotein extracted from chemically (compound IIIc, e, f and g) treated or UV-irradiated B. alexandrina snails did not show appreciable differences when compared to non-treated (native) snails by using SDS-PAGE, where no obvious qualitative or quantitative differences were observed. Immunization of experimental animals with the nucleoprotein extracted from native, chemically (compound III f & g) treated or physically treated B. alexandrina snails induced significant protection against challenge with normal S. mansoni cercariae, as compared to the non-immunized challenged control. As well as, a decrease in the number of granuloma formation and the size range of granuloma was also observed in immunized animals. It is concluded that, compounds III f and g have a potent molluscicidal activity. They also induced chemical modification comparable to that induced by physical treatment in the snail's nucleoprotein, which could possibly be used in immunization against S. mansoni infection.

Phenotypic analysis of cellular immune response in Swiss albino mice immunized with antigen extract from exposed B. alexandrina subjected to UV-, gamma irradiation and praziquantel treatment.

Mice were immunized (2x) subcutaneously at zero and 21st day with different antigen preparations. Splenocytes and mesenteric lymph nodes (MLN) cells were obtained from both immunized and control groups at 14th 21st and 42nd day post the 2nd immunization. The direct immunofluorescent assay was applied using anti mouse CD3+, D4+, CD8+, and IgG monoclonal antibodies to detect panel T-cells, T-cell subsets and B-cells respectively. The observations revealed that the splenic CD3+ T-cells did not show any considerable interrelation either between experimental groups or different time intervals post-immunization (P.I.). Meanwhile, UV-irradiated and PZQ-treated groups showed slight increase at the 2nd and 4th week P.I. as compared with the control group. The UV- and gamma-irradiated groups showed a significant elevation in CD4+ T-cells when compared with control group throughout the time of experiment, whereas, PZQ-treated group showed a significant increase at the 2nd and 4th week P.I. only. The frequency of CD8+ T-cells was elevated in all the experimental groups as compared with control group at 2nd, 4th and 6th week P.I. The MLN CD3+, CD4+ and CD8+ T-cells did not reveal any considerable changes between the experimental groups and control throughout the time of the experiment. A gradual decrease was observed in all the experimental groups by proceeding the time of the experiment. Splenic and MLN B-cells did not show considerable changes between the experimental groups and control group during the course of the experiment. It is concluded that these antigens could possibly stimulate cellular immune response upon their use as a protective antigens.

Identification of surface tegumental antigens of normal and irradiated schistosomula.

Sodium dodecyl sulphate- poly acrylamide gel electronphoresis (SDS-PAGE) fractionation of tegumental surface antigens (STEG-Ags.) of 7-day cultured normal and irradiated schistosomula showed no obvious qualitative differences. The observed polypeptide bands of both normal irradiated STEG-Ags. were almost identical and have similar corresponding molecular weights. The immunoblotting assay, using different types of mouse sera, revealed similarity between the bands of both normal and irradiated STEG-Ags. recognized by each type of mouse serum. No qualitative rather than quantitative differences have been observed. The quantitative differences were reflected in intensively staining of some bands from normal STEG-Ag. rather than their corresponding bands of the same molecular weights from irradiated STEG-Ag.

Effect of UV-irradiation, gamma irradiation and praziquantel on infected Biomphalaria alexandrina snails.

Schistosomiasis control represent the main target of many research programme allover the world. Effect of physical (UV- and gamma-irradiation) treatment as well as chemical (PZQ) treatment on infected laboratory bred Biomphalria alexandrina snails have been studied. Gamma irradiation and PZQ-treatment induced high rate of mortality than UV-irradiated and non-treated control snails. The cercarial production was severely reduced as a result of UV-, gamma-irradiation and PZQ-treatment. Pre-patent period was significantly increased in gamma-irradiated and PZQ-treated groups than UV-irradiated and control groups. Gamma irradiation and PZQ-treatment showed severe effects on hermaphrodite gland and cercariae. Trials of experimental infection in swiss albino mice revealed that low rate of infection (9.7% and 1.3%) was induced by cercarial shedding from UV-irradiated and PZQ-treated snails respectively. Whereas, cercarial production of gamma-irradiated snails failed to induce infection in swiss mice.

Haematological changes observed in Swiss albino mice infected with normal and gamma-irradiated E. granulosus larvae.

Five groups of Swiss albino mice (Mus Musculus albinus) were intraperitoneally inoculated with 2,000 aseptic normal (control group) and gamma irradiated E. granulosus, larvae at different dose levels of 40 Kr, 60 Kr, 80 Kr and 100 Kr, respectively. Haematological studies showed a marked leucocytosis, a progressive increase in the average percentage of eosinophils as well as a great successive decrease in haemoglobin concentration through out the time of infection in control group as compared to the treated ones. Meanwhile the leucocytic count and the Haemoglobin concentration in treated mice was dose dependent as well as time dependent whereas the eosinophil percentage was only dose dependent rather than time dependent.

Effect of gamma irradiation on the rate of cyst development of E. granulosus larvae in Swiss albino mice.

White albino mice Mus Musculus albinus were intraperitoneally inoculated with aseptical normal and gamma irradiated protoscolices of E. granulosus at dose level of 40, 60, 80 and 100 Kr. Mice, either normaly infected or infected with irradiated protoscolices and sacrificed at intervals of 4, 6, 8, 10, 12, 14 and 16 weeks, showed a marked increase in the percentage of cyst number in the liver than in the peritoneal cavity or around spleen, although by increasing the dose level to 100 Kr. no cyst were developed around the spleen. Meanwhile the % of developing cyst in the peritoneal cavity was time and dose level dependent. The mean cyst diameter showed a progressive increase with the increase of infection time and a successive decrease by increasing the dose level of gamma irradiation. An increase in the number of cyst was observed particularly in normal mice where a marked increase was noted on the 8th week post infection while a successive decrease in the mean number of cyst was observed by increasing the dose level of gamma irradiation.