RESUMO
Two direct methods for the diagnosis of trichinellosis were compared: trichinoscopy and artificial digestion. Muscles from 17 wistar rats, orally infected with 500 Trichinella spiralis encysted larvae were examined. From each of the following muscles: diaphragm, tongue, masseters, intercostals, triceps brachialis and cuadriceps femoralis, 648,440 larvae from 1 g samples were recovered. The linear correlation between trichinoscopy and artificial digestion was very high and significant (r = 0.94, p < 0.0001), showing that both methods for the detection of muscular larvae did not differ significantly. In both methods, significant differences were found in the distribution of larvae per gramme of muscle.
Assuntos
Trichinella spiralis/isolamento & purificação , Triquinelose/diagnóstico , Análise de Variância , Animais , Argentina , Distribuição de Qui-Quadrado , Ratos , Ratos WistarRESUMO
The aim of this study was to determine whether repeated ingestion of mycotoxin T-2 (T2) or aflatoxin B1 (AFL) at low doses could contribute to the activation of toxoplasmosis in experimentally infected mice. Mice were divided into two groups: Control (C) and Infected (I). The cyst-forming Beverley strain of Toxoplasma gondii was used to produce the infection one month before treatment with mycotoxins. Mycotoxins were given intragastrically for a 50-day period. The average weight gain was reduced in the groups treated with mycotoxins. Mice developed specific IgG to T. gondii. Histopathological studies showed severe encephalitis in all groups infected. The number of unruptured and ruptured cysts was established and the severity of the lesions was evaluated, the groups treated with mycotoxins being the most severely affected. Immunohistochemical studies of the brain showed free antigen in tissues surrounding ruptured cysts. It is suggested that low and repeated doses of mycotoxins, necessary to produce a subclinical intoxication, precipitate Toxoplasma cyst rupture and consequently the activation of chronic toxoplasmosis.
Assuntos
Aflatoxina B1/farmacologia , Encéfalo/patologia , Toxina T-2/farmacologia , Toxoplasmose Animal/etiologia , Animais , Anticorpos Antiprotozoários/análise , Antígenos de Protozoários/análise , Peso Corporal , Encéfalo/ultraestrutura , Doença Crônica , Encefalite/etiologia , Encefalite/patologia , Feminino , Imuno-Histoquímica , Terapia de Imunossupressão , Fígado/patologia , Meningite/etiologia , Meningite/patologia , Camundongos , Microscopia Eletrônica , Tamanho do Órgão , Toxoplasmose Animal/imunologiaRESUMO
The effects of aflatoxin B1 on the development of the immune response to oil-adjuvanted Bordetella bronchiseptica vaccine and on acquired resistance to bacterial challenge were studied in rabbits. The doses of aflatoxin used were insufficient to produce clinical intoxication. Rabbits were randomly assigned to three groups, each having six animals: control (T), vaccinated (V), and vaccinated plus aflatoxin (VA) at 0.05 mg/kg daily per os. Groups V and VA were vaccinated twice, and the three groups were subsequently challenged with virulent B. bronchiseptica. The average weight gain at weekly intervals was significantly reduced in group VA, and no statistically significant differences were found in the titers of agglutinating antibodies between groups V and VA. There were significant differences between groups V and VA in the extent and severity of the pneumonic process, group VA being most affected. Results indicated that agglutinating antibody titers were not related to the level of protection in the latter group. Other mechanisms, such as alveolar macrophage activity and cell-mediated immunity, were implicated in the impairment of the acquired resistance in rabbits subclinically intoxicated with aflatoxin.