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Biomedical subjects

F Scaravilli

Publications and source records attributed to F Scaravilli.

At least 181 records · Page 10Linked to original sources
PubMed1982

The pathogenesis of globoid cell leucodystrophy in peripheral nerve of the mouse mutant twitcher.

The twitcher mouse is affected by a disease with pathological features resembling those of human globoid cell leucodystrophy (Krabbe's disease): it also has an identical enzyme deficiency. The progress of the disease has been studied in peripheral nerves. Myelin sheaths develop normally until about the 15th day when the rate of myelination declines. Demyelination, first affecting paranodal regions is seen from the 10th-11th day before clinical signs appear. Krabbe-type inclusions are seen in macrophages and Schwann cells a few days later. Demyelination becomes extensive with increasing age, affecting fibres of all sizes, and axons rapidly remyelinate. Axons are not involved but quantitative studies show that they remain smaller than normal. Changes in twitcher nerves are compared to those in the neuropathy in human Krabbe's disease.

Animals↗
PubMed1982

Familial cerebral amyloidosis and spongiform encephalopathy.

Clinical and neuropathological investigations are presented of the "W" family in which there is a dominant inheritance of slowly progressive cerebellar ataxia and dementia. The disease is of insidious onset and its average duration more than 4 years. Pathological findings included amyloid deposition in cerebellar and cerebral tissue; vascular amyloid in one case; and spongiform encephalopathy and astrocytic hyperplasia typical of Creutzfeldt-Jakob disease. Neuritic plaques of the senile (Alzheimer) type were present to a lesser extent. This study confirms the familial association between cerebral amyloidosis and spongiform encephalopathy.

Adult↗
PubMed1981

The measurement of motor cell volumes in rats.

The volumes of cell bodies and nuclei of rat motoneurons were calculated from reconstruction in araldite embedded spinal cord. The results were compared with those obtained by applying formulae to two-dimensional measurements. The results show that the volumes of reconstructed cells have comparable values when derived from transverse and longitudinal sections. These values differ quite remarkably from those obtained by applying the formulae of the sphere and of a non-rotational ellipsoid. The difference is thought to reflect shape and orientation of the cells in the spinal cord. Nuclei were found to have a spheroidal shape, with the major diameter parallel to the axis of the spinal cord. There is also a linear relationship between cells and nuclear volume (with values varying between 5 and 15). The results of this study suggest that once reconstruction studies have shown the basic parameters of the cells, a graphical method for cell volumes from equatorial area measurements gives more satisfactory results than other proposed methods.

Animals↗
PubMed1981

Peripheral nerve grafts in hereditary leukodystrophic mutant mice (twitcher).

The twitcher mouse is a mutant affected by a form of leukodystrophy which shows close similarities to human globoid cell (Krabbe's) leukodystrophy. Transmission is by an autosomal recessive gene twi. Progressive loss of myelin sheaths from both central and peripheral nervous systems and the presence of inclusion-laden macrophages are characteristic findings. Morphological features of the twitcher have been described by Duchen et al. Nerve iso- and allografting have been used to determine the roles of axon and Schwann cell in a number of mouse and human nerve abnormalities. Schwann cells in a graft proliferate and become associated with regenerating host axons which grow through the graft into the host distal stump. In the twitcher, peripheral nerve axons do not degenerate but are thinner than normal, although there is considerable axonal degeneration in the central nervous system. In 15-day-old mutants, inclusions have been found in Schwann cells associated with apparently normal myelin sheaths. Grafting experiments might show whether the phenotype of this mutant is fully expressed in the Schwann cell, or if axons are also involved. In previous experiments, survival of transplanted Schwann cells was achieved by the use of T cell-suppressed or nude mice. We report here that a twitcher nerve transplanted in immunologically unsuppressed animals reproduces all the characteristic features of leukodystrophy and conversely that Schwann cells from unaffected mice can produce normal myelin when associated with twitcher axons.

Animals↗
PubMed1981

The pathology of allyl chloride neurotoxicity in mice.

Allyl chloride is known to produce a neuropathy in man after occupational exposure to its vapour. The present study describes the neuropathy which develops in mice given allyl chloride by mouth. Mice were dosed three times weekly with 300 or 500 mg/kg allyl chloride for periods from 2-17 weeks. Functional disability was observed in some animals. Apart from evidence of focal kidney damage in 70% of dosed mice, pathological changes were restricted to the nervous system. Nerve fibre degeneration was found in many peripheral nerves and in roots, tending to be more marked distally and to affect more motor than sensory nerves. Degenerated fibres were also found in dorsal, ventral and lateral columns of the spinal cord. Males were more severely affected than females. Increased numbers of filaments were on early axonal change, occurring multifocally and apparently preceding axonal degeneration. No neuronal death was observed, but occasional anterior horn and dorsal root ganglion cells showed some morphological changes. Vacuolated lesions mainly due to swelling of astrocytes and their processes were found in the ventral horn in cervical and lumbar regions of spinal cord. Animals appeared to become tolerant to allyl chloride after continuous dosing. This neuropathy appears to be a central-peripheral distal type of axonopathy.

Allyl Compounds↗
PubMed1981

Spinal haemangioblastoma associated with syringomyelia and multiple lung lesions.

Haemangioblastomas involving the spinal cord are uncommon but by no means unknown. It is well established that haemangioblastomas of the central nervous system are commonly associated with lesions in the retinae and in various abdominal organs. The simultaneous occurrence of similar tumours in the lung is less common and not well recognized. The case of a man with a haemangioblastoma of the spinal cord with many small haemangioblastomas of the lung is reported here.

Hemangiosarcoma↗
PubMed1981

Aspergillus granuloma of the trigeminal ganglion.

A patient is described with aspergillus flavus granuloma of the trigeminal ganglion. The patient was effectively treated by surgical excision of most of the infected tissue followed by intensive chemotherapy with amphotericin B and flucytosine.

Adult↗
PubMed1981

A new neurological rat mutant "mutilated foot".

A new autosomal recessive mutant rat (mutilated foot) with a neurological disorder is described. Affected animals become ataxic and the feet, generally of the hind limbs, are mutilated. Quantitative studies show a severe reduction in numbers of sensory ganglion cells and fibres, including unmyelinated fibres. The numbers of ventral root fibres, particularly those of small diameter, are also reduced. Markedly decreased numbers of spindles are found in the limb muscles. These quantitative abnormalities are present in animals of all ages and appear to be congenital. No nerve fibre degeneration is found in the spinal cord of young animals, but progressive degeneration of ascending tracts is seen with increasing age. Mossy fibre degeneration in the cerebellum confirms that the spinocerebellar tract is affected. The neurological disease in this mutant shows many similarities to that found in human hereditary sensory neuropathy.

Animals↗
PubMed1980

The development of sensory ganglion cells in normal and Sprawling mutant mice.

The foetal and early post-natal development of dorsal root ganglion cells in normal and Sprawling (Swl) mutant mice was studied by light and electron microscopy. As early as the 11th foetal day the nucleus of some neurons showed an indentation of its membrane and by the 13th day this abnormality was marked and present in many ganglion cells of foetuses which were, therefore, identified as presumptive Swl'. A peripherally situated nucleus and the aggregation of filaments and organelles in the central perikaryon were also early abnormalities, similar to those of the sensory neurons of the adult Swl mouse. In the normal ganglion cells, nuclei were rounded and central by the 16th foetal day and nuclear indentations were never seen, thus making a clear distinction possible between normal and Swl foetuses.

Animals↗
PubMed1980

Electron microscopic and quantitative studies of cell necrosis in developing sensory ganglia in normal and Sprawling mutant mice.

The percentage of neurons undergoing necrosis during foetal and early post-natal development in normal and Sprawling (Swl) mutant mice was determined. Two major peaks in the occurrence of necrosis were found at the 13th and the 19th foetal days in both groups of mice but at all stages the incidence was greater in Swl. Electron microscopically the first degenerative changes seemed to involve the perikaryon while many of the cells undergoing necrosis in Swl already showed the characteristic abnormalities previously described in that mutant.

Animals↗
PubMed1980

Hereditary leucodystrophy in the mouse: the new mutant twitcher.

A new inherited neurological disease in the mouse (the mutant twitcher) has been studied. Transmission is by an autosomal recessive gene (twi). Affected animals are apparently normal at birth but develop a generalized tremor at about 3 weeks of age followed by progressive weakness and wasting. The disease is fatal by 3 months. The principal pathological changes affect the myelin of both central and peripheral nervous systems. Degeneration of myelin sheaths and the presence of multinucleated macrophages with PAS-positive cytoplasm are characteristic findings. Peripheral nerves show remyelination following demyelination. Electron microscopically the macrophages contain a variety of inclusions in which there are crystalline and multi-angular structures and twisted tubules. The abnormalities closely resemble those found in globoid cell leucodystrophy (Krabbe's disease) in man.

Animals↗
PubMed1979

Moya-moya disease: clinical and pathological report of a case with associated myopathy.

A British born white man, age 51 years, presented with cerebrovascular insuffciency, and was found radiologically to have moya-moya disease. He also suffered from a let onset type of progressive myopathy. Five months after the first signs of cerebrovascular disease he died of massive cerebellar infarction. At necropsy the brain showed multiple old and recent infarctions. The anterior cerebral, middle cerebral, and posterior communicating arteries showed segments of narrowing and occlusion by delicate connective tissue, with marked thickening and folding of the elastic lamina. Many dilated thin-walled vessels without a muscle layer and with a poorly formed elastic lamina were present in the subarachnoid space, these probably being newly formed collateral vessels. The cause of the occlusive lesions affecting the cerebral arteries is not known but the morphological appearances do not fall within any known aetiology. It seems that moya-moya disease could be regarded as a distinct entity.

Arterial Occlusive Diseases↗
PubMed1977

Quantitative and electron microscopic studies of sensory ganglion cells of the Sprawling mouse.

The L4-6 sensory root ganglia of young and adult Sprawling (Swl) and normal mice were studied. Cell counts showed a great reduction in the total number of ganglion cells in Swl. Cell degeneration was observed in young Swl animals but not in normal littermates. Most of the remaining ganglion cells showed morphological abnormalities very similar to those seen in chromatolytic neurons-enlarged nucleolus, eccentric nucleus with an infolded nuclear membrane, loss of juxtanuclear Nissl bodies and an increase in neurofilaments, Golgi membranes, autophagic vacuoles, and dense bodies. In contrast to the classical changes of chromatolysis the abnormalities in Swl neurons persisted throughout the lifespan of the animals. Reconstructions from serial sections showed that ganglion cells in Swl were highly irregular in shape.

Animals↗
PubMed1977

The structure and composition of peripheral nerves and nerve roots in the Sprawling mouse.

Peripheral nerves and lumbar nerve roots of Sprawling, a neurological mutant mouse, were examined with light and electron microscopy. The peripheral nerves and the dorsal roots were thin and grey and were composed predominantly of small myelinated and unmyelinated axons. No evidence of axonal or myelin degeneration was found. Quantitative studies showed a marked reduction in the total number of myelinated axons with preponderance of those of 2-5 micron in diameter or less, most marked in the dorsal roots in which there was also an increase in the proportion of axons which were unmyelinated. In the ventral roots there was a deficiency in the contribution formed by myelinated axons of small calibre, probably indicating a deficiency of gamma fibres. Examination of the myelinated axons in nerves and roots showed a normal relationship between fibre size and internodal lengths and number of myelin lamellae. The findings suggest that the genetic defect in Sprawling is responsible for a failure of myelination of sensory axons. The deficiency of large sensory axons and of small motor axons can be correlated with the deficiency of muscle spindles.

Animals↗