Ultrastructure study of toxocara canis infective larvae extracted from eggs

The ultrastructure of Toxocara canis infective larvae is described. The buccal opening, the vestibule and esophagus are lined by a thick cuticle. Between the buccal opening and the vestibule, there are cuticular projections which might function as a valve. Epithelial cells that are associated with the vestibule and surround the esophagus, showed cytoplasmic lamellae with the possible osmoregulatory function of these cells. Active secretory gland cells are present in the esophagus. The secretion produced by these cells might be used to facilitate the migration of the larva. The unicellular excretory apparatus is typical of the ascarid group. Two lateral excretory columns extend on either side of the intestine, the excretory canaliculi are not well differentiated. The intestine is seen without apparent lumen and contains fat globules and glycogen particles which are found to be reduced in number in old larvae

chemiluminescent response of macrophages in mice infected with schistosoma mansoni

Peritoneal phagocytic cells when stimulated by Schistosoma mansoni infection in this study, exhibited a sudden increase in oxygen consumption known as a respiratory burst. This resulted in the production of toxic oxygen metabolites [H[2] O[2] and others]. The level of the toxic oxygen metabolites [chemiluminescence/cells] in normal mice and in mice infected with S. mansoni was measured in vitro. One week, one and two months after infection, a highly significant increase in the levels of chemiluminescence/cell was observed when compared to that of the normal control group. These oxygen metabolites have long been known to have microbicidal activity, and may take part in the ecytotoxic role in cell-mediated immune response against all stages of schistosomal life cycle in this study

Effect of capillaria hepatica infection on schistosoma mansoni challenge in mice

The combined infection between Capillaria hepatica and Schistosoma mansoni was studied. The results of this work revealed that C. hepatica infection induced significant reduction of S. mansoni worm load in the two groups infected with C. hepatica and challenged with S. mansoni either during worm maturation period of C. hepatica, or at the time of presence of C. hepatica eggs in the liver. Reduction in total and tissue egg count was also reported, but eggs excreted in the stool showed no difference in count from that of S. mansoni-infected controls. Oogram pattern of the experimental groups revealed a higher percentage of dead eggs and absence of mature and some developing stages. Scanning electron microscopy demonstrated severe destruction of adult worm of both groups. All these data showed the vigorous destructive effect of C. hepatica infection on the challenged S. mansoni

attempt to induce immunity against toxocara canis infection in albino mice parasltological studies

This study aimed at preparation and fractionation of the crude second stage Toxocara canis larval antigens and the determination of the optimal dose of the crude and fraction that gave the highest percentage reduction in the larval counts. The crude antigen was prepared from the second stage larvae after hatching of the cultivated larvated eggs obtained from the uteri of adult worms collected from 250 stray puppies. The antigen doses given individually in each group with a total dose of 12.5, 25, 50 and 100 mg protein, respectively. The crude antigen was further fractionated by column chromatography using Sephadex G-200. The dose of each fraction was calculated from the crude optimal dose according to their proportion in the elution volume. All immunized mice were challenged two weeks after the last imunizing dose by 800 larvated eggs. Brain larval count was done 30 days post-challenge to determine the optimal dose giveng the highest percentage reduction. It was found that a total dose of 12.5 mg protein of the crude antigen and the fourth fraction gave the highest percentage reduction in the larval count. These two antigens were further used to study the effect of immunization on humoral antibody responses. This was done by determination of the serum antibody level by the indirect fluorescent antibody test 3, 7, 15, 30 and 60 days post-infection. The antibody responses early and higher in the immunized groups than those of the controls. The maximum antibody level was reached at 15 days post-infection in all groups

Interleukin-2 level in mice infected with toxoplasma gondii

This work described the altered Interleukin-2 levels [IL-2] in mice infected with a virulent strain of Toxoplasma gondii and some possible mechanisms responsible for the alteration. To investigate this point, the effect of Toxoplasma infection was assessed shortly one week and then one month after invasion. Interleukin-2 production by stimulated Con A was reduced one week after infection and markedly depressed one month after infection with respect to normal controls. Unstimulated spleen cells from infected mice produced more IL-2 in vitro than stimulated cells. So, it can be concluded that IL-2 is one of the causes of immune suppression of Toxoplasmosis

Depressed membrane interleukin-1 activity of macrophage in mice infected with capillaria hepatica

This work has been directed to study the changes in the percentage and the membrane interleukin-1 [IL-1] activity of splenic and peritoneal macrophages in mice at different periods [the ends of second week, first month and third month of C. hepatica infection. A significant depression in the activity of membrane interleukin-1 was observed during all the periods of the study, while the percentage of splenic and peritoneal macrophages increased significantly. These results therefore, throw light on the fact that the metabolites of the migrating larvae, adult worms and eggs of C. hepatica impair cell-mediated immunity