Background: Infection with Toxoplasma gondii (T. gondii) leads to activation of T-helper cells (Th-1 and Th-2) which are involved in the synthesis and release of different cytokines which may lead to endothelial dysfunction. Objectives: To evaluate the endothelial function in patients with acute toxoplasmosis. Methods: This case-control study involved 31 patients with toxoplasmosis aged 19 -47 years matched with 20 healthy subjects. Anti-T. gondii antibody (IgG, IgM, IgA) was determined by direct antigen-antibody reaction. Interleukin-6(IL-6), endothelin-1 (ET-1) and human malondialdehyde (MDA) serum levels were measured. Results: IgM, IgG and IgA levels were high in the infected patients compared with controls (P < 0.01). Furthermore, IL-6 serum level was high in the infected patients compared with controls (P < 0.01). In addition, ET-1 level was high in acute toxoplasmosis (7.29 ± 4.59 pg/mL) compared with controls (3.11 ± 1.69 pg/mL) (P < 0.01). In addition, MDA serum level was high (9.34 ± 4.17 nmol/mL) compared with controls (2.87 ± 1.13 nmol/mL), (P < 0.01). In acute toxoplasmosis IgM serum level was significantly correlated with IgG (r = 0.55, P = 0.001), IgA (r = 0.57, P = 0.0008), IL-6 (r = 0.45, P = 0.01), ET-1 (r = 0.51, P = 0.003) and MDA (r = 0.85, P = 0.0001). Conclusions: Acute toxoplasmosis is associated with significant oxidative stress and pro-inflammatory changes which contribute to development of endothelial dysfunction.

Background: Trichomoniasis caused by Trichomonas vaginalis, is one of the most common sexually transmitted parasites in the world, accounting for approximately 170 million infections annually. Although the factor behinds such incidence is still not clear, local and systemic host immune response is involved. Objectives: Accordingly, the present research was planned to determine the level of immunoglobulins (IgA, IgG and IgM) in sera and vaginal washes of women infected with T. vaginalis. Materials and Methods: Fifteen women infected with T. vaginalis (culture confirmed) and 15 healthy females were inspected for total level of IgA, IgG and IgM in their sera and vaginal washes by means of single radial immunodiffusion. Results: The total level of IgA, IgG and IgM in serum and vaginal wash of patients and controls showed no significant difference, with the exception of IgG, which showed a significant increased mean in the sera of patients. Conclusion: Humoral immune response is important in controlling T. vaginalis, with a special reference to IgG.

Background: A number of investigators have carried out experimental infections of hydatidosis, using albino mice as an experimental animal model, but there was disagreement on the effect of strain, sex and age of this model. Materials and Methods: Two hundred and forty mice (120 males and 120 females) were injected intraperitoneally with a single dose of 2000 protoscolices (PSCs) /mouse at four ages (3-4, 7-8, 10 and 20 weeks). Each age group consisted of 60 mice (30 males and 30 females); in which 15 animals of each sex were the treated group, while the other 15 animals were a control group (injected with normal saline). Five animals from each age and sex were sacrificed at one, two and four month postinjection, and their livers and spleens were collected for histopathological examination. Results: the highest numbers of cysts and the most severe histopathological changes in livers and spleens of mice were observed at the age 3-4 weeks in both sexes. These changes increased with time post-infection. The changes became more severe in males than females in the age 7-8 weeks, but at the age 20 weeks, the females showed the most severe histopathological changes, while the age 10 weeks showed the lowest changes in both sexes. Conclusion:The age and the sex of the host can modify the course of infection with hydatidosis, and the present results suggest that, mice at the ages 3-4 (in both sexes) and 7-8 weeks old (males) produce the most severe pathological changes in these organs. The more resistant age to hydatidosis was observed at 10 weeks old in both sexes.