Spontaneous and experimental glycoprotein storage disease of goats induced by Ipomoea carnea subsp fistulosa (Convolvulaceae).

Spontaneous and experimental poisoning with the swainsonine-containing and calystegine-containing plant Ipomoea carnea subsp fistulosa is described. Three of 8 goats presenting with emaciation, weakness, symmetrical ataxia, posterior paresis, proprioceptive deficits, abnormal posture, abnormal postural reaction, and muscle hypertonia were necropsied. I fistulosa was suspected to be the cause of the neurologic disease in all cases. An experiment was conducted to confirm the diagnosis using 12 goats and diets containing 3 different concentrations of the plant. All goats fed I fistulosa developed neurological signs that were similar to those observed in the spontaneous intoxication. Muscle atrophy and pallor were the only macroscopic changes observed in spontaneous and in experimental intoxication. Histological lesions of spontaneous and experimental animals were similar. The most prominent lesion was cytoplasmic vacuolation in neurons of the central and the autonomous nervous system, pancreatic acinar cells, hepatocytes, Kupffer cells, follicular epithelial cells of the thyroid gland, and macrophages of the lymphatic tissues. Neuronal necrosis, axonal spheroids formation, and astrogliosis were additionally observed in the brain. Ultrastructurally, the cytoplasmic vacuoles consisted of distended lysosomes surrounded by a single-layered membrane. Nonreduced end-rests or sequence of alpha-Man, alpha-Glc, beta(1-4)-GlcNAc, and NeuNAc on lysosomal membrane were revealed by lectin histochemistry. Samples of plants used in the experimental trial contained swainsonine and calystegine and their intermediary derivate. We conclude that I fistulosa induces a glycoprotein storage disease primarily based on the inhibition of the lysosomal alpha-mannosidase by the alkaloid swainsonine.

Outbreak of copper poisoning in cattle fed poultry litter.

In a feedlot of about 1,000 head of cattle, 146 animals died within a period of a few months affected by a disease characterized by anorexia, icterus, hemoglobinuria, constipation, or diarrhea. The clinical course of the disease lasted a few days. Postmortem findings were generalized icterus and a yellow discolored liver. The kidneys were dark brown, and the urinary bladder was filled with urine of the same dark-brown color. The main histopathological findings were centrolobular coagulative necrosis, apoptosis, bilestasis, and proliferation of bile ducts in the portal space. Changes in the kidneys included nephrosis and the presence of bile and precipitates, and cylinders of albumin and of hemoglobin in the uriniferous tubules. Liver samples, collected from 3 animals on which postmortem examinations were performed, had 2,008, 2,783 and 4,906 ppm copper in their dry matter. Two samples of poultry litter fed to the cattle contained 362 and 323 ppm copper. The green forage that formed the rest of their feed only had 4.7 ppm copper. Copper poisoning was diagnosed, most probably caused by feeding litter from poultry that had been fed a ration treated with copper sulfate to avoid aspergillosis.

Epizootic botulism of cattle in Brazil.

The first diagnosis of botulism in cattle in Brazil and its epizootiology are reviewed. The high prevalence of the disease raised on phosphorus deficient pastures in Savanna regions has caused severe economic losses in the past. The temperature induced microcomplement fixation test (TIMCF) confirmed the clinical-pathological diagnosis in all of the 24 cases studied by this method. The most important reason why botulism has not been controlled satisfactorily in Brazil is the lack of an available effective vaccine (type C and D). Additional prophylactic measures are phosphorus supplementation and removal of carcasses from the pasture.

Livestock poisoning in South America by species of the Senecio plant.

The pyrrolizidine alkaloids retrorsine, senecionine, integerrimine, neosenkirkine and florosenine were isolated from different Senecio spp. common in southern Brazil, Uruguay and Paraguay. Structure elucidation of these compounds was mainly accomplished by two-dimensional FT NMR techniques. Detailed interpretations of 1H-1H and 1H-13C NMR correlation spectra are given. The alkaloids neosenkirkine, integerrimine and florosenine were found in Senecio leptolobus De Candolle, retrorsine accompanied by senecionine in Senecio selloi (Spreng.) DC and Senecio cisplatinus Cabrera. In Senecio heterotrichus DC. integerrimine is accompanied by retrorsine. Investigations on pathology and histopathology of Senecio envenomation in Brazil are summarized.

Macrocyclic trichothecenes: cause of livestock poisoning by the Brazilian plant Baccharis coridifolia.

Nine macrocyclic trichothecenes, thought to cause toxic effects in herbivors, were isolated from the Brazilian shrub Baccharis coridifolia. The structures of two new components, named miophytocene A and B, are described. Structure analysis was mainly accomplished by application of two-dimensional Fourier transform NMR techniques. The trichothecenes are most likely produced by the soil fungus Myrothecium verrucaria, which was isolated from soil samples around B. coridifolia. It is concluded that the plant is able to absorb and accumulate these mycotoxins. Histopathological studies on rabbits which received roridin E and A per os revealed mainly necrosis and hemorrhages of the mucosa of the colon and in the case of roridin A also of the caecum. Lethality in mice was generally low, intoxication proceeding slowly. It has to be considered, however, that all trichothecenes tested are practically insoluble in aqueous solutions and were applied as emulsions (i.p. and per os application). No trichothecenes or other toxic substances were detected from the Brazilian species Baccharis dracunculifolia, although slight toxic effects have been reported in cattle.

Ultrastructural evaluation of parathyroid glands and thyroid C cells of cattle fed Solanum malacoxylon.

Fine structural alterations of thyroid C cells and parathyroid chief cells were evaluated after feeding dried leaves of the calcinogenic plant, Solanum malacoxylon, to cattle for 1, 6 and 32 days. Thyroid C cells initially were degranulated in response to the hypercalcemia, and parathyroid chief cells accumulated secretory granules. There was hypertrophy of thyroid C cells with well-developed secretory organelles but few secretory granules in the cytoplasm after 6 days of feeding S. malacoxylon. Inactive chief cells with dispersed profiles of endoplasmic reticulum and increased lysosomal bodies predominated in the parathyroid glands. Multiple foci of soft tissue mineralization were present in the heart, lung, and kidney. Thyroid C cells underwent hypertrophy and hyperplasia after 32 days of S. malacoxylon, and parathyroid chief cells were inactive or atrophic in response to the long-term hypercalcemia. Severe soft tissue mineralization was present throughout the cardiovascular system, lung, kidney, and spleen. These ultrastructural changes in thyroid C cells and parathyroid chief cells plus the widespread soft tissue mineralization observed after feeding cattle small amounts of S. malacoxylon are consistent with the recent evidence that leaves of this plant are a potent source of the active metabolite, 1,25-dihydroxycholecalciferol, of vitamin D.