Massey Documents by Type
Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294
Browse
2 results
Search Results
Item Neuropathology of ovine ceroid-lipofuscinosis : a thesis presented in partial fulfilment (30%) of the requirements for the degree of Master of Philosophy in Veterinary Pathology at Massey University(Massey University, 1987) Shimada, AkinoriThe purposes of this study were to describe the neuropathology of ovine ceroid-lipofuscinosis, to compare findings with those of the related entities in humans and other domestic animals, and to provide morphological information that might help elucidate the pathogenesis of these diseases. An established flock of South Hampshire sheep carrying the ceroid-lipofuscinosis gene have made it possible to perform a longitudinal study on the central nervous system of affected sheep of various ages including foetuses. The most striking gross pathological change of affected sheep was brain atropy. At terminal disease, the brain weights of affected sheep were 55% of those of normal sheep. Atrophy affected mainly the cerebrum. Sudan black and luxol fast blue positive autofluorescent neuronal pigment granules were detected by lightmicroscopy as early as the mid stage of foetal development, the earliest stage examined. Postnatally there were topographical differences in the quantity of accumulated lipopigments in neurones of various areas. Similarly, there were age related topographical differences in secondary degenerative changes. Neuronal loss was most severe in the parietal lobe cortex showing an initial laminar distribution. This pattern was well demonstrated by a concomitant astrocytosis. In addition to the complex electron dense cytosomes similar to those reported in the human syndromes, there were less complex cytosomes of smaller size in affected foetal brains. The latter were clearly bounded by a trilaminar membrane and contained whorls or loose stacks of trilaminar membranes resembling those of the limiting membranes. In some electronmicrographs there was a suggestion of continuity between the surrounding membrane and the internal membranes, but this was not definitely demonstrated. This is provisionally interpreted as being due to an internalization of surrounding limiting membrane rather than a recycling of membrane. Some of these small cytosomes also showed complex multilamellar profiles similar to those of large complex cytosomes. These latter appeared to be formed by coalescence of smaller complex ones. There thus appeared to be a sequence of changes in the development of storage cytosomes. This study revealed that the ovine disease has not only many neuropathological findings in common with analogous human diseases, but also some pathological features which have not been reported in affected humans or animals. Ovine ceroid-lipofuscinosis is thus a useful animal model for the study of the human ceroid-lipofuscinoses.Item Ovine ceroid-lipofuscinosis : a thesis presented in partial fulfilment (70%) of the requirements for the degree of Master of Veterinary Science at Massey University(Massey University, 1979) Janmaat, AntonieOvine ceroid-lipofuscinosis is a rare inherited neurological disease which has only been diagnosed in one family of the South Hampshire breed of sheep. This breed is of relative recent origin and was established from an initial cross between Southdown and Hampshire Down sheep. Affected sheep show loss of vision and behavioural abnormalities starting at 11-12 months of age, with motor dysfunction commencing soon afterwards. The clinical signs increase in severity as the disease progresses and under field conditions affected animals are not expected to live beyond 2 years. Ovine ceroid-lipofuscinosis is characterized histologically by the intracytoplasmic accumulation of PAS and Sudan black positive autofluorescent lipopigment material in neurons and a wide variety of other cell types. The process leading to the accumulation of lipopigment seems only to damage neurons and there is degeneration and loss of neurons, especially in the cerebral cortex and the visual neuroepithelium of the retina i.e. retinal atrophy. Grossly, affected brains show reduction in size and weigh on average 66% of those of normal sheep. Ultrastructurally, the typical lipopigment inclusion is a round or oval body 0.2 - 5.0 μm in size, of varying electron density, in which a wide variety of membranous profiles may be seen. Some of the membranous patterns have received special names such as curvilinear, fingerprint and crystalloid. Pathological examination of liver, skin and rectal biopsy material of lambs at 4 - 5 months of age shows the presence of accumulated lipopigment, and is a means of early diagnosis before the onset of clinical signs. This observation and the fact that lipopigment has been demonstrated in affected lambs at birth, show ovine ceroid-lipofuscinosis to be associated with a true inborn error of metabolism. The family tree of all affected sheep and the results of sire-daughter matings of a heterozygous ram show the disease to be inherited as a simple autosomal recessive trait. The deleterious gene for ovine ceroid-lipofuscinosis is unlikely to be of economic importance to the sheep industry as the South Hampshire breed was developed to supply sires for terminal crosses associated with table lamb production. The objects of this study were to define ovine ceroid-lipofuscinosis in clinical, pathological and genetic terms, and to compare it with similar diseases in man and domestic animals. It is concluded that the ovine disease does indeed belong to the heterogeneous group of diseases of man and domestic animals known as Batten's disease or the neuronal or generalised ceroid-lipofuscinoses. Of these the ovine entity most closely resembles the late infantile and the juvenile forms of the human syndrome, and the canine disease. It is proposed that ovine ceroid-lipofuscinosis would make a useful experimental model for Batten's disease.