Damage of Purkinje cell axons following chronic phenytoin administration: an animal model of distal axonopathy

An animal model of central distal axonopathy following chronic administration of phenytoin is described. Male C57/BL6J mice received diphenylhydantoin (DPH) in the daily diet (liquid diet 'Stardit', supplemented with vitamins) over a period of 8 weeks. Control and experimental animals were pair-fed. Twelve mice of both groups were perfused via the left ventricle with glutaraldehyde. Representative samples of the cerebral cortex (area 3), cerebellum (vermis and deep cerebellar nuclei), thalamus, hypothalamus, and liver were embedded in araldite. Semi-thin sections and electron microscopy of the cerebellar vermis revealed marked dystrophic changes in the Purkinje cell axons. The presynaptic segments of Purkinje cell axons in the deep cerebellar nuclei showed massive enlargement and swelling due to accumulation of spherical particles and tubular structures in the axoplasm. These structures represent a proliferation of the smooth endoplasmic reticulum. Identical changes were found in hepatocytes of treated animals. Because phenytoin induces hepatic microsomal enzymes, we suggest that phenytoin-related Purkinje cell damage may be produced by an induction of Purkinje cell microsomes with proliferation of the smooth endoplasmic reticulum which causes a swelling and enlargement of presynaptic segments of Purkinje cell axons in deep cerebellar nuclei. Chronic phenytoin administration to mice is a new model of phenytoin-induced encephalopathy and of distal axonopathy of cerebellar neurons.

Dendritic inclusions in the cerebellar granular layer after long term alcohol consumption in adult rats

Whorled multiplanal inclusions up to 1.5 micron in diameter were observed in dendrites of the cerebellar Golgi cells after 6 months of alcohol treatment, increasing in number with time. Inclusions are formed by apposed cytomembranes stacked parallel or in a twisted arrangement. The paired membranes merged into a dense, finely textured material. A close relationship with dendritic smooth endoplasmic reticulum is apparent. A correlation between chronic alcohol intake and the development of these inclusions is shown although, in common with many other types of neuronal cytoplasmic inclusions, their genesis and function remains to be determined.

Lipofuscin granules in cerebellar interneurons after long-term alcohol consumption in the adult rat

Lipofuscin deposition in nerve cells is one of the most reliable and consistent neurocytological features correlated with ageing. Purkinje cells of long-term alcohol-fed rats show large agglomerates of lipofuscin granules after six months of alcohol experiment, whereas in normal biological ageing, this happens only after 25 months of age. Cerebellar interneurons have specific patterns of lipofuscin accumulation during ageing concerning both its morphological type and chronology of deposition. We studied the effects of chronic alcohol treatment on cerebellar interneurons taking particular account of lipofuscin pigment accumulation. Control and alcohol-fed groups for 1, 3, 6, 12 and 18 months were used. A precocious and progressive accumulation of lipofuscin granules occurred in granule, Golgi and basket cells. Stellate cells remained pigment-free. The lipofuscin deposited in the granule and Golgi cells was of the granular type, whereas that of basket and stellate cells was lamellar (fingerprint-like pattern). These results parallel those observed during normal ageing, and reinforce the hypothesis of the existence of a close relationship between chronic alcohol consumption and precocious nerve cell ageing.

Morphologic evaluation of stereotactic brain tumour biopsies

The validity of morphologic diagnosis of stereotactic brain tumour biopsies was evaluated in a series of 600 patients treated since 1977 at the University Hospital, Freiburg. Combined cytological (smear preparations) and histological examination of paraffin-embedded samples revealed the tumour type and approximate grading in 492 (82%) of cases. In 66 patients a clinically suspected neoplasm could be ruled out. In the remaining 42 cases (7%), the presence of a tumour was confirmed but the available samples did not allow an unequivocal classification of the neoplasm. Inaccurate diagnoses were most frequently due to sampling errors in non-homogeneous tumours, i.e. biopsies taken from sites not representative for the entire neoplasm (tumour necroses, infiltration zone). In the future, the use of immunohistochemical methods for the identification of tumour markers and cytoskeleton proteins may partially compensate for the limited size of stereotactic biopsy samples.

Cerebellar histogenesis and synaptic maturation following pre- and postnatal alcohol administration. An electron-microscopic investigation of the rat cerebellar cortex

Fetal alcohol syndrome was produced in rats by feeding an ethanol-enriched, vitamine -supplemented liquid diet over a period of 4 weeks before mating and throughout pregnancy. The amount of ethanol was equivalent to 38-40% of the daily calories; control animals were fed an isocaloric amount of sucrose. The offspring of experimental animals displayed a diminished birth weight. In contrast to previous experiments, the ethanol diet was also administered during the lactating period. On postnatal day 7, experimental animals and controls were killed by perfusion and the cerebella prepared for electron microscopy. Morphometric analysis showed a reduced number of Purkinje cells. On day 12, Purkinje cells of experimental animals displayed ultrastructurally fewer organelles. Furthermore, a delayed synaptogenesis in the molecular layer was demonstrated with osmium-zinc iodide and ethanolic phosphotungstic acid showing an immature appearance of the presynaptic grid and weaker stained synaptic cleft material. The following discussion deals with possible mechanisms underlying these alcohol-induced alterations of cerebellar synaptogenesis.

The lectin properties of gluten as the basis of the pathomechanism of gluten-sensitive enteropathy

The pathogenesis of gluten-sensitive enteropathy is as yet unknown. According to one theory gluten may act as a lectin with toxic properties for the intestinal cells. We can now confirm this theory by laser nephelometric measurements and demonstrate the oligomannosyl specificity of this lectin-like protein gluten. Furthermore, we demonstrate the highly more intensive binding capacity of gluten for the glycoproteins of the immature crypt cells of the intestinal brush border compared to those from the mature villous zone. It is discussed that gluten-sensitive enteropathy is caused by a genetically determined defect-glycosylation of intestinal glycoproteins with the synthesis of more mannosylated glycoproteins.

[Morphology of dementia of the Alzheimer type]

Senile dementia of the Alzheimer type (SDAT) is one of the most common diseases of the nervous system in the over-65 population of the United States and in northern Europe. Clinical features of SDAT are dysfunction of memory, changes in the personality and others. The following report deals with morphological changes in SDAT. First, histological alterations of SDAT like neurofibrillary tangles and neuritic plaques are described together with some experimental work on neurofibrillary changes induced by spindel inhibitors and aluminum. Second, the role of the cholinergic system deficiency in SDAT is discussed concerning the selective loss of cholinergic neurons and the cholinergic innervation of neuritic plaques.

Morphometric analysis of the rabbit myocardium after chronic ethanol feeding - early capillary changes

Male rabbits were fed with ethanol for 3 weeks. 10 ml of a 20% ethanol solution were applied daily with a stomach tube. The macroscopic, histologic and ultrastructural investigation of the hearts did not reveal and structural alterations. Morphometrically, the endothelial cells of the capillaries were changed, whereas the muscle cells did not show any abnormalities. The quantitative data indicate that the numerical density of endothelial cells is increased, whereas the volume density is not changed. This type of quantitative reaction pattern may be characterized as "proliferation" of endothelial cells. The proliferation is possibly related to ethanol-induced metabolic changes similar to chronic hypoxia. On the other hand, there is some evidence that the alteration is part of a general activation of mesenchymal cells in various organs after ethanol ingestion. The alteration is probably an early stage of the proliferation of capillaries.

Impaired maturation of Purkinje cells in the fetal alcohol syndrome of the rat. Light and electron microscopic investigations

Alcohol was administered in a vitamin-supplemented liquid diet (Stardit) to Wistar rats 4 weeks before mating and during pregnancy. Of the daily calories 38--40% were supplied by alcohol and by isocaloric sucrose in the controls. Offspring of alcohol drinking dams showed a reduced birth weight and gained weight less rapidly than the controls. On day 3, 4, 7, 12, 17 and 21, experimental animals and controls were perfused for histological and electron microscopic investigations. Morphometric analysis of the cerebella (Fol. 5 and Fol. 8) showed no difference in the number of Purkinje cells. However, on day 7 the Purkinje cell nuclei of experimental pups were significantly smaller. This difference disappeared at day 12. Electron microscopic investigations in the 4, 7, and 12 days old experimental animals revealed a delayed cytoplasmic maturation of Purkinje cells which mainly involved the rough endoplasmic reticulum. At 17 days, there was no difference between the two groups. These data are discussed in relation to alcohol-induced metabolic changes in the brain.

Studies of human myelin proteins during old age

The electrophoretic protein patterns of myelin isolated from frontal and callosal white matter were studied in adult man up to the age of 90 years. The proportions of the four major myelin proteins remained virtually unchanged as did the total protein content of white matter and of purified myelin. The total mass of purified myelin that could be recovered from white matter gradually decreased with age, suggesting an age-related loss of myelin sheath and probably neurons as well, without detectable alterations of the regular protein composition of myelin. In most cases basic protein of myelin was preceded by one or two minor protein components on electrophoresis. One of them is tentatively identified as "prebasic" protein similar to the one previously observed in other species, because of its close electrophoretic apposition to the main basic protein. The second component was found less frequently and was thought to arise from specific types of proteolysis of myelin proteins. Prolonged time intervals between death and autopsy had little, if any, effect on the proportions of basic protein and proteolipid protein. Similar results were obtained when bovine brain was incubated under conditions designed to simulate post-mortem autolysis. It was there fore concluded that meaningful data on proteins of human central myelin may be obtained even though an autopsy was not performed within a few hours of death.

Paired helical filaments in rat spinal ganglia following chronic alcohol administration: an electron microscopic investigation

Young Wistar rats were given a 15% (v/v) ethanol solution ad libitum for at least 6 months, spinal ganglia (C6-7 and L1-2) in some of the experimental animals showed paired helical filaments. These curvilinear profiles consisted of 10 nm filaments with the twist every 35nm. There was also an increase in granular material and in nematosomes. Whether these features may be caused by an impaired cerebral protein biosynthesis is discussed.

Peripheral intraaxonal storage in Tay-Sachs' disease (GM2-gangliosidosis type 1

Considerable intraaxonal lipid storage was observed in intramuscular nerve fibres mainly of the extraocular muscles and less frequently in limb muscles of a 3-year-old child, which had suffered from Tay-Sachs' disease. Many axons of the small intramuscular nerve twigs and of the terminal and preterminal nerve endings showed spherical and cylindrical enlargements containing granular storage material of the same staining properties as the material in the central nervous system. The identify of the axonal and the neuronal storage material was further confirmed by electron-microscopical demonstration of typical multilamellated cytoplasmic bodies (MCBs) in both of them. In addition, silver impregnation and electron microscopy revealed dystrophic changes with an increase of argyrophilic filamentous material within some of the axonal distensions, indicating that the latter were probably due to both a lipid storage and an unspecific dystrophic process.

Alcohol embryo- and fetopathy. Neuropathology of 3 children and 3 fetuses

Maternal chronic ethanol abuse during pregnancy causes malformations of the offspring. Three children (aged 6 months, 9 months, 4 1/2 years) and 3 fetuses (17th, 18th, and 20th gestational week) showed a wide spectrum of disorders ranging from severe dysraphic state, arhinencephaly, porencephaly, agenesis of corpus callosum, a range from hydranencephaly to microdysplasias (p.e. reduced gyration of dentate nucleus and inferior olives), and a range from gastrochisis or congenital heart defects to craniofacial dysmorphogenesis and palmar crease anomalies. The patterns of the cerebral malformations were not as uniform as the clinical phenotype of the alcohol embryopathy. The observations did not support the assumption that there exists a specific period for alcohol teratogenicity.

Amyloid neuropathy due to monoclonal gammopathy. A case report

A case with peripheral neuropathy due to monoclonal gammopathy is reported. There was striking, dissociated symmetrical sensory loss and paresis, the legs being affected predominantly. The case is compared with the few reported cases of myelomatous neuropathy, and the clinical and histological findings are discussed in view of the pathogenesis.

[Delayed cerebellar histogenesis in "embryofetal alcohol syndrome". Light microscopic study of the rat cerebellum (author's transl)]

The cerebellar postnatal development of young rats (Wistar) was investigated, whose mothers were given a 12% (W/V) ethyl alcohol solution for 7 days before and during pregnancy. Besides weighing less at birth, the experimental animals had a slower postnatal linear growth and gained weight less rapidly. Histological examination of the cerebellum showed an inpeded histogenesis, which could be observed in the Purkinje cells up to the 10th postnatal day. Moreover, a thick layer of embryonal granular cells with numerous mitoses could still be seen in the experimental animals at 3 weeks of age. After 30 days there was no histological difference between the controls and experimental animals. Because the Purkinje cells in the developing cerebellum represent the units were ribosomes are most abundant, it seems appropriate to ask, whether the observed inhibition of histogenesis could derived from an impaired cerebral protein synthesis. Disturbance of organogenesis was observed in three experimental animals afflicted with an extreme internal hydrocephalus.

[Extraneural metastasizing oligodendroglioma (author's transl)]

A 40-year-old man suffered from a right parietal oligodendroglioma. Two months after the onset of clinical symptoms complete removal of the tumor was attempted. At second craniotomy four years later the tumor was found to invade the falx cerebri. The patient died seven years after the first admission to the hospital. Necropsy revealed the right parietal oligodendroglioma invading the sagittal sinus and the left hemisphere as well as metastases in the lung, the lymph-nodes, the vertebra, and the femur.

[Hypertrophy of the transversal tubular system in target fibres. An electron microscopic study (author's transl)]

In a muscle biopsy from a patient suffering about 2 years from an amyotrophic lateral sclerosis groups of atrophic fibres and target fibres were observed. By electron microscopic examination, amongst numerous parallel or spinal cisternae near the plasma membrane, single-membrane bound smooth tubular elements with a constant diameter of 200-300 A occur in the central and intermediary zone of some target fibres. The connexion between these tubules and the terminal cisternae (triads) of the sarcoplasmic reticulum, suggest that this phenomenon seems to be a proliferation of the transversal-tubular system due to the partial denervation. Only a mechanical displacement of the T-tubules as a result of the destruction of the muscle fibres is not plausible, because the T-system volumetrically amounts only 0.3-0.5% of the muscle fibre.