Porcine Taenia solium cysticercosis, recognized as a model of the human disease, was used to analyze the effect of the anthelminthic drug praziquantel on hosts and parasites. The drug (50 mg/kg daily) was given over 15 days in the feed of 13 cysticercotic and 9 control pigs. Changes in the number, size and appearance of brain parasites were seen by computerized tomography immediately after the last dose of praziquantel, although not all cysticerci had disappeared by day 47 following the end of the treatment. Muscle parasites became small and hyperdense shortly after treatment and disappeared from tomographic images afterwards. No alterations were found in EEGs or in brain-stem auditory and somatosensory evoked potentials. Muscle cysticerci showed increasing degrees of degeneration with time after treatment, and an augmented inflammatory reaction was concomitantly observed. In contrast, more heterogeneous results were obtained in parasites lodged in the brain, since viable cysts and less intense inflammatory reactions were found in the brain at different times after treatment. Physiological evaluation of the parasites showed that evagination was inhibited immediately after treatment and that oxygen consumption decreased with time. The results of this investigation suggest that praziquantel damages cysticerci and that the inflammatory reaction destroys and eliminates them.
Introduction-Maximal oxygen uptake (VO 2 peak) is an indicator of cardiorespiratory fitness, but requires expensive equipment and a relatively high technical skill level.
Human and porcine cases of neurocysticerosis were compared by computed tomography in regard to the morphological characteristics of the parasites and the impact of the infection on the brain. In pigs and young people many parasites were usually found, but this was seldom the case in adult humans. These parasites were small and located mainly in the parenchyma and the subarachnoid space; no calcified cysticerci were found. In contrast, in adult humans cysticerci were heterogeneous in appearance and distribution. The brain of the pigs showed no evidence of inflammatory reaction while young people had oedema, enhancement and hydrocephalus; in contrast, adults showed diverse tomographic characteristics of brain response. Thus, the disease has at least 2 different forms. It may be mild with short development and parasites of similar appearance, as occurs in young hosts. In contrast, a long lasting disease occurs in adults, with diverse tomographic, neurological and parasitological features.
The objective of this study was to evaluate the degree of protection against TB of three immunogens in calves experimentally challenged with a pathogenic Mycobacterium bovis strain by identification of lesions during necropsy. Twenty-four calves free of TB were distributed into four groups: group 1 was inoculated with M. bovis CFPE, group 2 with CFPE/IFN-gamma, group 3 with M. bovis BCG, and group 4 remained as control. After 6 months all animals were challenged with an M. bovis field strain, and 6 months later the animals were euthanized and the presence of lesions was evaluated. Several degrees of protection were observed in the vaccinated groups, particularly in the group vaccinated with BCG, as shown by the absence or decrease in severity of lesions. Vaccination could be useful in high-prevalence zones where it is economically unfeasible to slaughter animals.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.