Axenic in vitro culture of Schistosoma mansoni miracidia.

Miracidia of Schistosoma mansoni have been grown axenically. The use of saline solution of 0.75% facilitated the shedding of epidermal plates which if occurred promote a rapid sporocystogenesis. Also, the use of a ratio of 1:3 (fetal calf serum and medium 199) in addition to chernin balanced salt solution (SBSS) was ideal for maintaining sporocysts up to 14 days. All the miracidia sheded their epidermal plates 2 hours post cultivation. At the end of the second week post cultivation, the daughter sporocysts measured 690u in length by 50u in width. The usage of plastic flat sided flasks with plenty of culture medium was very important for induction a proper growth of sporocysts because it was possible that adherence of sporocysts to each other might delay their growth.

Studies on the sacculant portion of the kidney of Biomphalaria glabrata Say (1818) as a haemopoietic organ.

The term immunity signifies all those properties of the host which confer resistance to a specific infectious agent. This resistance may be of all degrees ranging from complete to incomplete susceptibility. The defensive functions is performed by various cellular and humoral components which interact with each other producing a co-ordinated immune response directed towards eliminating the pathogen or minimizing its danger. Snails as other members of the Animal Kingdom have their own immune system. The present study concentrated on the sacculant portion of the kidney of B. glabrata as a haemopoietic stem cell. The histological picture of this portion in the kidney as well as in-vitro culture was studied. (I) The histological studies showed that (a) the sacculant portion constituted the last fifth of the kidney highly folded with primitive epithelial tissue, (b) amoebocytes (10.7 +/- 0.98m) rounded, oval or amoeboid, showing flattening and spreading when encapsulated around foreign particles, when doing so, both the cytoplasm and nucleus were more basophilic, (c) the haemocytes in the sacculant portion were distributed either as clustering forming amoebocytic plugs or dense aggregation or being normal in distribution (d) there was a significant correlation between haemocytic diameter and shell weight and between shell weight and shell diameter but no significant correlation between haemocytic diameter and shell diameter. (II) The in-vitro studies showed that (a) The medium 199 and fetal calf serum (3:1) produced higher number of granulocytes, (b) the cells differed in shape and size from those shown in histological studies of the kidney itself (c) the majority of the cells were large sized granulocytes and very few small sized hyalinocytes, (d) granulation of cytoplasm took place in the culture medium used more than in the sacculant portion, (e) only the smaller granulocytes showed greater ability for mitotic division. The results were photographed and discussed.

Effect of the behavioural stress on susceptibility of Syrian hamsters to Schistosoma mansoni infection: effect on number and fertility of worm burden.

Effect of pairing on susceptibility of male Syrian hamsters to Schistosoma mansoni infection in comparison to their isolated counter-parts have been studied. Pairing resulted in significant differences between paired and isolated hamsters in measurements of eggs, miracidia, number of adult worms recovered and mean testicular number of males. Paired hamsters seemed to be immunologically suppressed and such a suppression resulted in increasing the fertility and number of worms recovered. The width of the male schistosomes recovered from the paired hamsters was two folds and the length was four folds greater than those recovered from isolated ones. The mean testicular number was 8.17 +/- 0.53 in males recovered from paired hamsters and 6.16 +/- 0.71 in those recovered from isolated ones. Of interest was, the demonstration of a male with two groups of testes recovered from a paired hamster. It was concluded that the stressed host reflex effects on the number and fertility of the schistosome worms burden, and hence the severity of the disease and its complications.

Studies on the nematode parasites from Egyptian rodents. I. Spirurid nematodes.

Three spirurid nematode species have been collected from Egyptian rodents in Giza province. Streptopharagus kuntzi was collected from stomach and small intestine of Rattus ratus, R. norvegicus, Arvicanthis niloticus and Gerbillus gerbillus. Protospirura muris and P. marsupialis have also been collected from A. niloticus, R. rattus and R. norvegicus but P. marsupialis was collected only from the stomach while P. muris collected from stomach and small intestine. P. marsupialis was firstly recorded in Egypt during this work and no males of this species were collected. Females of S. kuntzi and P. muris showed marked dominance over males. Streptopharagus sudanensis and S. kuntzi are placed in synonomy.

Larval occurrence of Hydatigera taeniaeformis Batsch (1786) (Cestoda: Taeniidae) in the liver of wild rodents in Egypt.

Hydatigera taeniaeformis Batsch (1786) was found in the liver of six species of Egyptian wild rodents. Wanas et al., (1990) found the total incidence of this larval stage to be 20.0% among cestode infection. It was found in (40.9%) Rattus norvegicus; (33.3%) Gerbillus gerbillus; (26.8%) Rattus rattus; (25.0%) Mus musculus; (16.6%) Acomys cahirinus; and (7.2%) Arvicanthis niloticus. The cysts of Hydatigera taenioformis was always occupying the marginal surfaces of both right and left lobes and sometimes there was a double cyst contained two strobilae. The rostellar hooks used for identification. The strobilae obtained were in different stages of development. The rostellar hook system was complete and so the suckers but the segment showed no maturation. Morphological characters and role of rodents as intermediate host for such cestode are discussed.