الفهرس 
Trichinella spiralisOnly 14 pages are availabe for public view
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Abstract
Trichinella spiralis has a uniquely complex life cycle with different stages which vary in their susceptibility to killing by leucocytes (Callahan et al., 1988). The antiparasitic and antimicrobial activity of leucocytes and other inflammatory cells are closely related to reactive oxygen species production triggered during phagocytosis or activation (Rosen et al., 1995). To protect against the potential damage of oxidants, parasites, including T, spiralis, have evolved complex non enzymatic and enzymatic antioxidants (Entrala et al., 1 997 and Selkirk et al., 1 998). Enzymatic antioxidants act as scavengers that irradicate free radical species and prevent their lethal effect on worms (Smith et al., 1998). Diabetes mellitus is a prevalent metabolic disorder associated with increased susceptibility to various infectious agents, chiefly due to depressed cell mediated immunity (Bell and Hockaday, 1996). It induces, also, a state of prolonged oxidative stress, responsible, at least partly, for most of its complications (Doi et al., 2001). The aim of this work was to assess the role of free radicals and antioxidants on the course of infection by T. spiralis in diabetic animals. In order to fulfill this aim, the following was done: One hundred and sixty eight Swiss albino mice were used and divided into 4 equal groups: noninfected norrnoglycaemic (group I), noninfecfed diabetic (group 11), infected and normoglycaemic (group 111) and infected 99 diabetic (group IV). Seven animals from each group were taken at 3,6,12,18, 25 and 35 days of infection and were submitted to the following procedures: 1) Sera were taken for estimation of MDA, catalase, superoxide dismutase, glutathione and glutathione peroxidase. 2) Small intestines were taken for adult worm count, histopathological study, and estimation of MDA in small intestinal homogenates. 3) Larval count in the muscles in the whole carcasses of mice with histopathological study. 4) Determination of MDA, glutathione, catalase, superoxide dismutase and glutathione peroxidase in larval homogenates. from the previous work, the follo wing results were obtained: 1) The diabetic infected animals revealed higher adult worm count with delayed worm expulsion from the small intestine, with less intense inflammatory reaction and delayed histologic resolution in the small intestine as compared to normoglycaemic infected animals. MDA levels were higher in diabetic group at late stages of infection. 2) Higher muscle larval count with diminished inflammatory reaction and defective encapsulation were observed in diabetic infected animals as compared to non diabetic infected group. 3) Increased levels of antioxidant enzymes and MDA were observed in the larval homogenate of the diabetic infected group (IV) as compared to non diabetic infected group (111). 4) Sera of infected diabetic animals showed higher levels of MDA and antioxidant enzymes which were closely related to the duration of infection. from the previous results, tlze follo wing could be concluded: 1) Diabetes mellitus has caused flaring up of T. spiralis infection (both phases) in the affected host mainly due to depression of the immunologic response. 2) Parasitic infection and diabetes mellitus are both sources of oxidative stress which has damaging effects on both the host and the parasites. 3) The parasites have protected themselves by increasing production of protective enzymatic antioxidants to scavenge damaging free radical species.