the immunogenicity of γ-irradiated tachyzoites of a highly virulent strain of toxoplasma gondii (rh strain) was investigated. immunized mice survived challenge infection and displayed increased interferon gamma (inf-γ ) production. on the other hand, nonimmunized controls died after 10 days and displayed a significantly decreased lymphoproliferative response to concanavalin a (con a). no tachyz...

The Immunogenicity of γ-irradiated tachyzoites of a highly virulent strain of Toxoplasma gondii (RH strain) was investigated. Immunized mice survived challenge infection and displayed increased interferon gamma (INF-γ ) production. On the other hand, nonimmunized controls died after 10 days and displayed a significantly decreased lymphoproliferative response to Concanavalin A (Con A). No tachyz...

Although the Sabin-Feldman dye test is the gold standard for detecting Toxoplasma antibodies in human, it is performed only in reference laboratories because live virulent T. gondii are used for the test. We collected 210 human serum samples and tested them by the dye test using in vivo tachyzoites (conventional method) then compared these results with three other methods: a dye test using cell...

Toxoplasmic retinochoroiditis is a common blinding retinal infection caused by the parasite, Toxoplasma gondii. Basic processes relating to establishment of infection in the human eye by T. gondii tachyzoites have not been investigated. To evaluate the ability of tachyzoites to navigate the human retina, we developed an ex vivo assay, in which a suspension containing 1.5 × 10(7) parasites repla...

We report herein anti-proliferation effects of 4-arylthiosemicarbazides, with a cyclopentane substitution at N1 position, on highly virulent RH strain Toxoplasma gondii. Among them, the highest in vitro anti-Toxoplasma activity was found meta-iodo derivative. Further experiments demonstrated inhibitory thiosemicarbazides tyrosinase (Tyr) activity, and good correlation between percentage Tyr inh...

Toxoplasma gondii tachyzoites and tissue cysts are largely used for developing diagnostic assays, vaccines and in drug research as well as biochemical and molecular structure studies. Continuous passaging of tachyzoites or tissue cysts in animal models encounter ethical and economical problems and it is a time consuming procedure. Cryopreservation of tachyzoites and tissue cysts and revitalizat...

Neospora caninum is a protozoan parasite that can cause severe disease in mammals. Two experiments were conducted to examine the effects of subcutaneous (s.c.) vaccination with Hank's balanced salt solution (HBSS), 1 x 10(5) N. caninum NC-1 strain tachyzoites or 1 x 10(5) Toxoplasma gondii TS-4 strain tachyzoites on challenge oral infections in mice with sporulated VEG strain T. gondii oocysts ...

Current strategies for the control of toxoplasmosis are based on chemotherapy, however successful vaccine has also been demonstrated. The present study aims to assess the effect of the vaccination with radiation-attenuated tachyzoites in challenged mice regarding histopathological alteration and DNA damage of hepatocytes. Sixty mice were equally divided as follow: Group I left as a normal contr...

BACKGROUND The aim of this study was to evaluate the effects of conjugated linoleic acid (CLA) on apoptosis of tachyzoites of T. gondii, RH strain (type I) and the cyst-forming Tehran strain (type II) in vitro. METHODS Toxoplasma strains were injected into the peritoneal cavity of BALB/c mice. The Tehran strain forms cysts in the brain of mice. Bradyzoites within the cysts are reactivated to ...