Abstract In the present study, the histological effect of melatonin (MEL) on pinealectomized (PINx) and normal rats’ testes was investigated. Thirty six adult male rats were used in this study. The rats were divided into six experimental groups as follow: 1st control group; 2 nd sham-operated surgery rats group; 3rd PINx rats group, 4th PINx rats+MEL (60 mg / Kg diet) group; 5th control rats+MEL (60 mg / Kg diet) group; and 6th control rats+MEL (120 mg / Kg diet) group and the treatments were continued for six weeks. The result showed mild histological changes in testicular tissue of sham-operated surgery rats, like shrinkage and atrophy of seminiferous tubules (STs) and weakness in spermatogenesis. While, in PINx rats revealed regressive changes in testicular tissue, like sever degeneration, vacuolation and necrosis in germinal epithelium and no spermatogenesis. But as PINx rats were given MEL 60 mg/kg diet, the testicular structure and function were recovered, whereas, in normal rats were given MEL 60 and 120 mg/kg diet, the result show sever vacuolation and sloughing of spermatocytes inside STs lumen and no spermatogenesis at rats+60 MEL and mild edema with well development of germinal epithelium and spermatogenesis at rats+120 MEL. In conclusion, the deficiency of MEL level leads to change in histology and physiological activities of rat testes. Key words: melatonin, pinealectomy, rat, testis histology

In the present study, the histological effect of titanium dioxide nanoparticles (TDN) on testicular tissue of mature Mus musculus mice was investigated. The animals were divided into six groups, control group treated with TDN free saline and five groups treated with TDN as follow 5, 10, 50, 100 and 150 mg/kg B.W. The results showed that TDN has histological effects on testicular tissue like sever congestion, mild edema between seminiferous tubules (STs) and decrease the thickness of germinal epithelium at low concentrations, While, the histological changes at high concentrations involved disturbance in STs diameters, sever edema between STs, sever vaculation in the germinal epithelium and necrosis in spermatogonia, germinal epithelium and Sertoli cells. KEYWORDS: Mus Musculus Mice, TDN, Histological, Seminiferous Tubules, Sertoli Cells.

In the present study, the inhibitory effect of Lipopolysaccharide, xtracted from Pseudomonas aemginosa, on growth of Leishmania major promastigotes in vitro was investigated. The results showed that the Lipopolysaccharide investigated had a marked i n h i b i t o r y effect, at different concentrations on growth of the promastigotes. The concentration 100 u,g/ml showed a 37% i n h i b i t i o n ratio where as it is about 50% at both 10 jug/ml & 300 jug/ml, representing the LD50. The concentration 20 jug/ml showed 65% inhibition ratio. 50 ug /ml & 500 jug /ml showed the highest inhibition ratio as it was 76% and 81 %, respectively. Lipopolysaccharide had the same inhibitory effect on the number of cells, number of generation and the generation time.

Activity of the polysaccharide PS extracted from the wall of Pseudomonas aeruginosa (IN-1) was tested, for the first time. in albino BALB/c mice. against infection with hydatid disease. Growth and development of hydatid cysts in mice activated with PS, prior to infection, was investigated, taking into consideration number. weight and diameter of cysts growth, in addition to percentage reduction. The results obtained show reduction in number. weight and size of cysts with high percentage reduction. An obvious decrease in the weight of liver and spleen, and their organ indices, in mice activated with PS compared to the increase noticed in the weight of these organs in the control group, was also noticed. suggesting the use of PS as an immunomodulator against infection with hydatid disease. Keyword: Echinococcosis, immunization, Pseudomonas aeruginosa, polysaccharide.

The study investigated the effect of polysaccharide (PS).for the first time, extracted from Pseudomonas aeruginosa. on cell-mediated immunin represented by delayed-type hypersensiti- vity test and phagocytosis in BALB\c mice infected aith unilocular hydatid disease (protoscole- The significant increase in the foot pad thickness and phagocytic index of neutrophils in acti- vated mice with PS. prior to infection, indicates thar this polysaccharide possesses an ability to stimulate the cellular immune response in mice against infection with unilocular hydatid disease. ces of Echinococcus granulosus). Results proved also that treatment with polysaccharide is time and dose - dependent. delayed-type hypersensitivity. phagocytosis. Keywords: Echinococcosis, hydatid disease. poiysaccharide, Pseudomonas aeruginosa,

Activity of the lipopolysaccharide LPS extracted from the wall of Pseudomonas deruginosa (IN-1) was tested, for the first time, in albino BALB/c mice, against infection with hydatid disease. Growth and development of hydatid cysts in mice activated with LPS, prior to infection, was investigated, taking into consideration number, weight and diameter of cysts grown, in addition to percentage reduction, The results obtained show reduction in number, weight and size of cysts with high percentage reduction. An obvious decrease in the weight of liver and spleen, and their organ indices, in mice activated with LPS compared to the increase noticed in the weight of these organs in the control group, was also noticed, suggesting the use of LPS as an immunomodulator against infection with hydatid disease. Keyword: Echinococcosis, immunization, Pseudomonas aeruginosa, lipopolysaccharide,

Immunomodulating activity of graded doses of the lipopolysaccharide (LPS) extracted from Pseudomonas aeruginosa (IN-i) was tested, for the first time, in mice against infection with hyda- tid disease. The effect of LPS on total and differential count of leucocytes was investigated. Results show that LPS activates macrophages, stimulates proliferation of lymphocytes and infiltration and migration of neutrophils and monocytes to the sites of infection. Evidence is provided that (LPS) modulates the immune defense of mice against infection with unilocular hydatid disease. Key words: Echinococcosis, immunization, Pseudomonas aeruginosa, lipopolysaccharide.

The study investigated the effect of lipopolysaccha from Pseudomonas aeruginosa, on cell-mediated immunity represented by delayed-type hyper- sensitivity test and phagocytosis in BALB\c mice infected with unilocular hydatid disease (Proto- scoleces of Echinococcus granulosus). The significant increase in the foot pad thickness and phagocytic index of neutrophils in acti- vated mice with LPS, prior to infection, indicates that this lipopolysaccharide possesses an ability to stimulate the cellular immune response in mice against infection with unilocular hydatid disea- se. Results proved also that treatment with lipopolysaccharide is time and dose-dependent. for first time, extracted Keywords: Echinococcosis, hydatid disease, lipopolysaccharide, Pseudomonas aeruginosa, de- layed-type hypersensitivity, phagocytosis.