Effect of the plant Azolla pinnata on survival, growth rate, fecundity and hatchability of egg-masses of Biomphalaria alexandrina snails.

Data indicated that Azolla pinnata plants variously reduce the growth rate of Biomphalaria alexandrina snails expressed as net increase in shell diameter (direct or indirect exposure). The plant density played an important role in this respect. The higher the plant density was the lower the growth rate and vice versa.

Abnormal zinc and copper metabolism in hepatic steatosis.

Abnormal Zinc and Copper metabolism were studied in rats with tetracycline-induced fatty liver and compared with normal rats. The present work recorded decreased serum zinc concentration with increased copper concentration in the tetracycline-injected rats. The results also showed that the liver and heart zinc were significantly decreased; meanwhile it was observed that the concentration of zinc in the kidney tissue of fatty liver rats was significantly raised in comparison with those of normal rats.

Population dynamics and schistosomal infection of Biomphalaria alexandrina in four irrigation canals in Egypt.

The natural growth, reproductivity, mortality and schistosomal infection of Biomphalaria alexandrina, the snail vector of Schistosoma mansoni in Egypt, were studied for one year in four irrigation canals, namely El-Khassa and Radwan (Giza Governorate) and Sendebis and Sanafeer (Qalyoubiya Governorate). Radwan canal contains a considerably dense Biomphalaria population and three generations of snails (parents generation and autumn and spring generations) were recognized. Two phases of growth were distinguished in both autumn and spring generations, a faster phase followed by a slower one.

Ecology of Biomphalaria alexandrina the snail vector of Schistosoma mansoni in Egypt.

The patterns of spreading and seasonal variation of population density of Biomphalaria alexandrina, the snail vector of Schistosoma mansoni in Egypt, in correlation with some environmental parameters were studied for 1988-1990 in four irrigation canals in Giza and Qalyoubiya Governorates. Results shown that the spreading patterns of snails along canals are changeable because of water current and irrigation activities. The snail population density showed two peaks, different in height, in April-May and November-December separated by two bottoms following the Winter Closure and during the hot summer season.

Helisoma duryi: its present range of distribution and implications with schistosomiasis snails in Egypt.

The range of distribution of Helisoma duryi, a potential competitor to schistosomiasis snail vectors in Egypt, was determined in the south of Nile Delta. Results show that H. duryi was found in the River Nile, Geziret El Kerateyeen banks, Damietta and Rosetta Branches, Tawfiky and Menoufy Canals and their branches and Bassoussiya, Bahadiya and Sheshaa canals and their branches.

Effect of ultraviolet radiation on Ia expression by keratinocytes.

Many skin diseases, such as graft-versus-host disease (GVHD), are marked by lymphocyte infiltrates in the skin. Severity of these diseases is often correlated with the induced expression of class II antigens (human, HLA-DR,; murine, Ia) by the keratinocytes. This suggests that HLA-DR-expressing keratinocytes may be involved in the pathogenesis of these diseases.

Effect of Schistosoma mansoni infection, starvation and molluscicides on acid phosphate, transaminases and total protein in tissues and hemolymph of Biomphalaria alexandrina.

The activities of GOT and GPT in the hemolymph of B. alexandrina were significantly decreased by S. mansoni infection.

An animal model of antibody binding in cutaneous lupus.

To study antibody binding in cutaneous lupus, we used human skin grafted onto nude mice. By immunofluorescence examination, mice injected with anti-Ro (SS-A) sera from subacute cutaneous or neonatal lupus erythematosus patients showed evidence of human IgG deposited in the skin, while mice injected with anti-native DNA or normal sera did not. We present evidence that there is specific binding of anti-Ro (SS-A) antibodies to Ro (SS-A) antigen in the skin, and we propose that these antibodies may be directly involved in cutaneous disease.

Biology of Langerhans cells: analysis by experiments to deplete Langerhans cells from human skin.

In vivo studies have demonstrated that various treatments of skin, e.g., UV irradiation, topical corticosteroids, and tape-stripping, will temporarily deplete the epidermis of Langerhans cells (LC).

The prepatent period and cercarial production of Schistosoma haematobium in Bulinus truncatus (Egyptian field strains) at different constant temperatures.

The developmental time of Schistosoma haematobium in Bulinus truncatus snails (field strains) was determined in the laboratory at different constant temperatures between 18 and 32 degrees C. The basic relationship between the length of the minimum prepatent period (y, in days) and the temperature (x, in degree C) is given by the hyperbolic formula y = 295/(x-15.3), 15.

Expression of Ia antigen on epidermal keratinocytes after the grafting of normal skin to nude mice.

During the course of experimentation designed to evaluate the migration of host Langerhans cells (LC) into normal skin grafted onto nude mice, we observed that the epidermal cells of these grafts were induced to express la determinants solely of graft origin. The data presented herein indicate that the expression of la by normal epidermal cells correlates with the infiltration of host LC into the graft. This la expression is restricted to the keratinocytes within the epidermis of the grafted skin, is first observed 7 to 9 days post-grafting, and persists within the grafted skin for greater than 12 wk.

Biology of Langerhans cells: selective migration of Langerhans cells into allogeneic and xenogeneic grafts on nude mice.

A major question challenging immunobiologists relates to those mechanisms that control the selective movement of cells involved in immune and inflammatory processes at various tissue sites such as the skin. Little is known about those influences that control the selective migration of macrophage-like Langerhans cells (LC) to normal epidermis, where it is uniformly distributed. Mechanistically, this includes the interaction of blood-borne LC precursors with the vascular endothelium of the skin and those factors that control the migration of the LC into the avascular epidermal component of the skin.

Cell-mediated hyperacute rejection. I. Acute, accelerated, and hyperacute reactions.

The morphology of first-set rejection of allogeneic murine skin grafts differs strikingly from that usually seen subsequent to sensitization. In the former, graft epithelium appears to be the primary target; in the latter, the endothelium of graft vessels. This difference suggests that different subsets of effector T cells may be involved.

The influence of temperature, darkness, and starvation on growth and survival of Helisoma duryi, Biomphalaria alexandrina and Bulinus truncatus.

The influence of 10 degrees, 18 degrees, 26 degrees, 28 degrees and 33 degrees C, different periods of complete darkness and starvation on growth and survival of H. duryi, B. alexandrina and B.

The molluscicidal properties of some Bayluscide homologues.

The molluscicidal properties of 5-nitro- and 3-nitro2',4'-dichloro salicylanilides and their mixture 5.5 : 1 were investigated against the intermediate hosts of schistosomes Bulinus truncatus and Biomphalaria alexandrina. Unlike Bayluscide, the activity of the new mulluscicides is not affected by strong sun radiation or by acidic pH.

The molluscicidal properties of natural products from Ambrosia maritima.

The molluscicidal properties of Damsin "I", Ambrosin "II", and tribromodamsin "III" were investigated against the intermediate hosts of schistosomiasis Biomphalaria alexandrina and Bulinus truncatus. Although Damsin was to some extent more toxic against B. alexandrina than the other two compounds, it was less toxic than them against B.