The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform

Robert M. Waruiru - One of the best experts on this subject based on the ideXlab platform.

  • Autoradiographic quantification of the efficacy of Niridazole in mice infected with 75Se-labelled cercariae of Schistosoma mansoni
    Veterinary Parasitology, 1992
    Co-Authors: Robert M. Waruiru
    Abstract:

    Abstract The effects of the anti-schistosomal drug, Niridazole, on the migration of Schistosoma mansoni larvae, biosynthetically radioisotope-labelled with 75 [Se]-selenomethionine, was evaluated by autoradiography of compressed tissues of mice treated daily from Days 6 to 10 post-infection with 200 mg kg −1 Niridazole. The results were compared with the migration of schistosomula in untreated controls. The distribution of schistosomula was altered in Niridazole-treated mice, where there was a delayed migration from the lungs relative to the controls and significantly fewer schistosomula in total appeared to reach the liver. The total percentage of schistosomula detected as autoradiographic foci was significantly lower in treated mice than in the untreated controls. Niridazole-treated mice were free of any foci 10 days after the last treatment and no adult worms were recovered on perfusion of the hepatic portal system relative to control mice from which 5.8% of the infective cercariae were recovered as adult worms at Day 42 post-infection.

Akos Szakmary - One of the best experts on this subject based on the ideXlab platform.

  • Mutagenic effects of Niridazole in animal-mediated and in liquid suspension assays using Escherichia coli K-12 as an indicator
    Mutation research, 1992
    Co-Authors: Siegfried Knasmüller, Akos Szakmary
    Abstract:

    Abstract The mutagenic effects of the antischistosomal drug Niridazole (1-(5-nitro-2-thiazolyl)-2-imidazolidinone) were investigated in liquid suspension and intrasanguineous animal-mediated assays with mice. As indicator strains Escherichia coli K-12 343 113 (Nir s ) and a newly constructed Niridazole nitroreductase-deficient derivative ( Escherichia coli K-12 343 113 Nir r 200) were used. With the parental strain (Nir s ) induction of nalidixic acid- and valine-resistant mutants was observed under in vivo conditions in the liver and, to a lesser extent, in the spleen. Positive results were also found when intestinal homogenates, blood sera, and urine samples of Niridazole-treated animals were tested in vitro with the wild-type strain. With Escherichia coli K-12 343 113 Nir r 200 no clear-cut positive results were obtained in animal-mediated assays. In liquid suspension assays positive results were restricted to the urine samples. These findings indicate that the positive results obtained with the wild-type strain are due to nitroreduction and that the concentrations of mutagenic metabolites formed by activation processes in the living animal are too low to enable their detection in inner organs, intestines, and the blood with the reductase-deficient strain. In agreement with our present findings showing increased genotoxicity in urine, Niridazole causes tumors in rodents preferentially in the kidneys and in the bladder.

Sylvnus Josiah Dafur - One of the best experts on this subject based on the ideXlab platform.

Siegfried Knasmüller - One of the best experts on this subject based on the ideXlab platform.

  • Mutagenic effects of Niridazole in animal-mediated and in liquid suspension assays using Escherichia coli K-12 as an indicator
    Mutation research, 1992
    Co-Authors: Siegfried Knasmüller, Akos Szakmary
    Abstract:

    Abstract The mutagenic effects of the antischistosomal drug Niridazole (1-(5-nitro-2-thiazolyl)-2-imidazolidinone) were investigated in liquid suspension and intrasanguineous animal-mediated assays with mice. As indicator strains Escherichia coli K-12 343 113 (Nir s ) and a newly constructed Niridazole nitroreductase-deficient derivative ( Escherichia coli K-12 343 113 Nir r 200) were used. With the parental strain (Nir s ) induction of nalidixic acid- and valine-resistant mutants was observed under in vivo conditions in the liver and, to a lesser extent, in the spleen. Positive results were also found when intestinal homogenates, blood sera, and urine samples of Niridazole-treated animals were tested in vitro with the wild-type strain. With Escherichia coli K-12 343 113 Nir r 200 no clear-cut positive results were obtained in animal-mediated assays. In liquid suspension assays positive results were restricted to the urine samples. These findings indicate that the positive results obtained with the wild-type strain are due to nitroreduction and that the concentrations of mutagenic metabolites formed by activation processes in the living animal are too low to enable their detection in inner organs, intestines, and the blood with the reductase-deficient strain. In agreement with our present findings showing increased genotoxicity in urine, Niridazole causes tumors in rodents preferentially in the kidneys and in the bladder.

J. Massoud - One of the best experts on this subject based on the ideXlab platform.