RESUMO
GM1-gangliosidosis is caused by a reduced activity of ß-galactosidase (Glb1), resulting in intralysosomal accumulations of GM1. The aim of this study was to reveal the pathogenic mechanisms of GM1-gangliosidosis in a new Glb1 knockout mouse model. Glb1-/- mice were analyzed clinically, histologically, immunohistochemically, electrophysiologically and biochemically. Morphological lesions in the central nervous system were already observed in two-month-old mice, whereas functional deficits, including ataxia and tremor, did not start before 3.5-months of age. This was most likely due to a reduced membrane resistance as a compensatory mechanism. Swollen neurons exhibited intralysosomal storage of lipids extending into axons and amyloid precursor protein positive spheroids. Additionally, axons showed a higher kinesin and lower dynein immunoreactivity compared to wildtype controls. Glb1-/- mice also demonstrated loss of phosphorylated neurofilament positive axons and a mild increase in non-phosphorylated neurofilament positive axons. Moreover, marked astrogliosis and microgliosis were found, but no demyelination. In addition to the main storage material GM1, GA1, sphingomyelin, phosphatidylcholine and phosphatidylserine were elevated in the brain. In summary, the current Glb1-/- mice exhibit a so far undescribed axonopathy and a reduced membrane resistance to compensate the functional effects of structural changes. They can be used for detailed examinations of axon-glial interactions and therapy trials of lysosomal storage diseases.
RESUMO
The aim of this paper is to describe the first report of spontaneous poisoning by Prosopis juliflora in sheep. From flock of 500 sheep at risk, four adult male sheep were affected. One died spontaneously and three other were examined, euthanized and necropsied. Neurologic examination focused particularly on motor and sensory-cranial nerve function, complete blood counts, serum biochemistry and urinalysis were done. The evolution of the disease was chronic and to present signs of poisoning, sheep had to ingest a diet containing at least 80% of P. juliflora pods during 21 months. The biochemistry revealed a substantial increase in creatine phosphokinase levels. Clinical signs included drooling of saliva, dropped jaw, tongue protrusion and loss of food from the mouth. Gross and histological lesions were similar to those previously reported in cattle and goats. Sheep are more resistant to poisoning by P. juliflora considering that it took 21 months of pod consumption to show clinical signs. There is no specific treatment for P. juliflora poisoning in ruminants.(AU)
O objetivo deste trabalho é descrever o primeiro caso de intoxicação espontânea por Prosopis juliflora em ovinos. De um total de 500 ovinos sob risco, quatro ovinos machos adultos foram afetados. Um ovino morreu espontaneamente e os outros foram examinados, eutanasiados e necropsiados. Realizaram-se exames clínicos direcionados particularmente para funções de nervos motores e sensoriais-craniais. Avaliou-se hemograma, perfil bioquímico sérico e urinálise. A evolução da doença foi crônica e para apresentar sinais de intoxicação os ovinos tiveram que ingerir uma dieta contendo 80% das vagens de P. Juliflora durante 21 meses. Os níveis de creatinofosfoquinase estavam significativamente elevados. Os sinais clínicos consistiram em sialorreia, mandíbula pendulosa, protusão da língua e perda de alimento pela boca. As lesões macroscópicas e microscópicas foram similares àquelas reportadas previamente em bovinos e caprinos. Ovinos são mais resistentes à intoxicação por P. Juliflora, tendo em vista que foi necessário 21 meses de consumo das vagens para que os ovinos apresentassem sinais clínicos. Não há tratamento específico para a intoxicação por P. Juliflora em ruminantes.(AU)
