Search

As reported previously, the perivascular cells laden with fluorescent granules (FGP cell) are situated in Virchow-Robin space and show marked uptake capacity for intraventricularly administered substances. The phagocytic FGP cells are derived developmentally from leptomeningeal cells and are recognizable in various kinds of animals, including humans. In the present paper, the FGP cells of rodents are studied by immunological techniques. It is clearly demonstrated that rat FGP cells express the antigenic determinant for Ia antibody at about 7 days after birth, and also that mouse FGP cells show a positive reaction against mouse Fc and splenic macrophage antibodies at about the same developmental stage. The specific determinants of FGP cells appear concurrently with the initiation of horseradish peroxidase uptake. On the other hand, Ia antigen is also shown in subarachnoid macrophages, but not in immature FGP cells, endothelium and pericyte. Based on these findings, it seems reasonable to consider that the FGP cells are indigenous cerebral macrophages and significant for the local immune response in a cerebral tissue. Further, in this paper, to prevent confusion of the FGP cell with the other perivascular cells, the authors propose designating the FGP cell as Mato cell.

This paper examines the neuropathology of oxygen-glucose deprivation uncomplicated by stagnant conditions. Rabbit vagus nerves were pulled into asmulti-compartment perfusion chamber, stimulated five times per second and deprived of energy by substituting nitrogen and deoxyglucose for oxygen and glucose in the Locke's perfusate. After incubation the compartments were perfused with gluteraldehyde solution, and the nerves were prepared for electron microscopy. Fixation in the compartments ensured precise cross and longitudinal sections which permitted quantitative comparisons. Although the action potentials ceased in 45 min, 1 h of energy deprivation did not significantly affect the ultrastructure. After 2 h of deprivation the axons were smaller and flattened and microtubules appeared packed together. In the smallest axons the microtubules were gone, the neurofilaments were compacted and the few mitochondria had a dense, homogenous appearance. By 4 h the shrinking was extreme, yet 8% were swollen much larger than any of the controls. Longitudinal views showed these balloned areas were greatly expanded regions of the smallest axons. Both tiny and huge regions were devoid of microtubules and the swollen axons contained expanded mitochondria.

This paper describes three cases of what is probably a new form of storage disorder. The affected animals were English Springer Spaniels and they had developed progressive neurological signs when 2–3 years old. They had gross enlargement of the vagi and of the spinal nerves supplying the brachial plexus. By light microscopy in these nerves there were massive amounts of endoneurial loose fibrous tissue with dispersion of nerve fibres and many foamy phagocyte-like cells. In the central nervous system there was very severe cytoplasmic vacuolation of most neurones and neuroglia, perivascular phagocyte-like cells, loss of myclin, loss of Purkinje cells, numerous spheroids, hypertrophic astrocytes and fibrous astrocytosis. There was also foamy cytoplasmic vacuolation of renal convoluted tubules and pancreatic exocrine parenchyma and numerous foamy phagocyte-like cells in lymph node and lung. On ultrastructural examination membrane bound vacuoles wee present in the cytoplasm of affected neurones and phagocyte-like cells. Most of the vacuoles were empty, some contained amorphous materials and some, in neurones, contained stacks of curved or straight lamellae. It is suggested that the stored material could be an oligosaccharide.

Forty anesthetized rats were cooled below 3°C by 30-min transcardial perfusion of chilled physiological saline before a concussive head injury. The animals were then perfusion-fixed with a buffered formaldehyde-glutaraldehyde solution. Another forty rats were fixed by 30-min transcardial perfusion of the same fixative before a similar concussive head injury. In brain sections of both groups of animals a new silver method stained, in a Golgi-like fashion, a number of neurons and long axonal segments scattered among unstained ones. The similarity between these findings and those obtained following in vivo concussive head injuries described in accompanying papers suggests that the formation of traumatically induced argyrophilic neuronal damage is independent of metabolic processes, i.e., it may be a primary morphopathological process.

Thirty-four rats were killed by transcardial perfusion fixation 1 min after a contusing concussive head injury, and 17 rats 1 day later. From the results obtained with a new silver method demonstrating traumatically damaged neuronal somata, dendrites and axons the following conclusions were drawn: (1) outside the contused territories all features of traumatically induced neuronal argyrophilia are similar to those found in non-contusing concussive head injury, as reported in an accompanying paper; (2) within contused territories the neuronal argyrophilia is abolished by some substance released either from damaged blood vessels or from damaged parenchymal cells, while the neuronal damage otherwise underlying the induction of argyrophilia is present; (3) different phenotypes of neurons are vulnerable to different values of the parameters of the intracranial pressure wave generated by the trauma; (4) some of the neurons may recover from the traumatically induced argyrophilic damage; (5) traumatically induced inundation of neurons with extracellular tracers, as reported by other authors, and somato-dendritic argyrophilia may be different manifestations of one and the same phenomenon; and (6) diffuse primary traumatic axonal injury in human neuropathology may be closely correlated to axonal argyrophilia.

In rat striatum severe hypoglycemia causes an irreversible nerve cell injury, which does not become manifest until during the post-insult recovery period. This injury can be ameliorated by lesions of the glutamatergic cortico-striatal pathway, which suggests that an “excitotoxic” effect mediated by the glutamatergic input is the likely cause of the posthypoglycemic nerve cell destruction. In this paper we further characterize the protective effect of abolishing the glutamatergic innervation to striatum at the ultrastructural level. Two weeks after a unilateral cortical ablation rats were subjected to 30 min of severe hypoglycemia with isoelectric EEG and killed either immediately after the insult or following 60 min of recovery induced by restoring the blood glucose levels. Immediately after the hypoglycemic insult the structure of striatum was similar on both sides (except for the changes attributable to the ablation); i.e., the neurons and their dendrites had pale cytoplasm with condensed mitochondria, sparse RER and pinpoint ribosomes. After 60 min restitution numerous striatal neurons on the non-protected, non-ablated side had turned variably dark and condensed, whereas under-neath the ablation they remained similar as immediately after hypoglycemia. This sequence indicates that the most likely cause of nerve cell destruction on the non-protected side is the “excitotoxic” effect mediated by the glutamatergic innervation, which is superimposed on the action of the hypoglycemic insultper se. Furthermore, the primary condensation of neurons and their dendrites indicate existence of another type of acute “excitotoxic” nerve cell injury which differs from the previously described injury characterized by neuronal swelling.

Five patients died of a severe neuromyopathy months after the ingestion of adulterated rapessed oil. These patients were selected for this study due to the presence of striking chromatolytic lesions in symmetric and scattered nuclei of the brain stem, including the locus coeruleus, midline raphe, lateral reticular nuclei of the medulla and cuneate nuclei. Two of the five cases, in addition to these topographic levels of involvement, had remarkable chromatolysis, vacuolar degeneration and heavy silver impregnation of the swollen perykarya and proximal dendrites in the nuclei of the basis pontis. In this paper we analyze the features of the chromatolytic lesion and suggest that the neuronal pathology observed in these cases is an example of irreversible chromatolysis involving vacuolization and filamentous proliferation as final events of the chromatolytic process. The cause of the cell degeneration in the toxic oil syndrome (TOS) is yet undetermined. Chromatolysis in this disease may be the result of a neurotoxic action of the toxic factor in the adulterated oil.

Progressive systemic sclerosis (PSS) is a chronic inflammatory disease of the connective tissue with involvement of the skin and other organs. The disease is characterized by an abnormal accumulation of collagen in all tissues and by microangiopathy. The involvement of the peripheral nervous system during PSS is very unusual and few cases are reported in the literature. A morphological study on the neuropathy associated with sclerodermia has been performed in rare cases. In this paper we demonstrate the role that the vascular lesions have in the pathogenesis of neuropathy during scleroderma. In particular, the primary role of the peripheral microangiopathy during PSS (observed in different clinical cases) is verified.

Two siblings born from consanguineous tunisian parents are reported. They showed a severe form of Farber's disease with prominent involvement of the central and peripheral nervous system: low conduction velocity was noticed in both children. Macular cherry red spots were observed in one of them. The diagnosis for the girl investigated was confirmed by evidence of ceramidase deficiency in cultured fibroblasts. Here we report the pathological findings in the subcutaneous nodules using light and electron microscopy (one case), and in sural nerves using morphometric studies (both cases). Varying morphological aspects of intracellular inclusions, depending on the tissues involved, are described and discussed. A review of all cases reported since Farber's first paper in 1952 is given.

Part I of this paper has documented the evolution of dark neurons into acidophilic neurons in the superficial laminae as well as the reversion of dark neurons to normal neurons in the deep laminae of the cerebral cortex in hypoglycemic brain damage. The present study describes the temporal evolution of hypoglycemic brain damage in the hippocampus.

A karyometric analysis of 346 Feulgenstained biopsy preparations (4 µm) of gliomas (glioblastomas; fibrillar, protoplasmic and gemistocytic astrocytomas; pilocytic astrocytomas; oligodendrogliomas) using the automated microscope picture analysis (AMPA) was carried out in continuation of a previous paper (Martin and Voss 1982). Fifteen morphometrical, densitometrical and mitotic preparation features were evaluated:

Galactose neuropathy is characterized by progressive endoneurial edema manifested by a gradual increase in endoneurial fluid pressure. Edema accumulates via a unique mechanism of osmotic force generated by products of the polyol pathway, synthesized within the endoneurial compartment. This paper presents morphologic findings showing firstly, that blood nerve barrier permeability to horseradish peroxidase complexes appears unchanged and secondly, peripheral nerve edema in this condition is restricted to extraganglionic endoneurium sparing the spinal ganglia and adjacent roots. Thirdly, mast cells accumulated in significant numbers and electron microscopy revealed degranulation. There was no evidence of edema in Schwann cell cytoplasm, the putative site of galactitol accumulation via the sorbitol pathway. These findings are discussed with respect to diabetic neuropathy for which galactose intoxication is a useful experimental model.

This paper first gives a short introduction into the principles of stereology. It shows then its actual application to the assessment of ultrastructural-morphometric data of the normal superior cervical ganglion of the rat (base-line data) and after axotomy. In the early phase after axon transsection the volumetric composition of the superior cervical ganglionic neuron remains constant. Only the volume density of the lysosomal forms is significantly increased from 0.9–3.2%. Ultrastructural morphometric analysis of the rough endoplasmic reticulum does not provide any information on quantitative changes underlying the phenomenon of central chromatolysis.

Ultrastructural study of the biopsied sural nerve in a case of infantile neuroaxonal dystrophy was made. The characteristic change in the ballooned axons is an accumulation of membranous profiles associated with mitochondria, glycogen like granules, dense bodies, vesicles and electron lucent material. The membranous profile is classified into three morphological types and discussed on each of them. Probably tubulo-membranous profile of the first type is most common and may be cardinal deposit in this condition. These membranous structures of various types might be, however, only different manifestations occurring on the same morbid process. Enormous amount of glycogen like granules and mitochondria might be related to the metabolic derangement of carbohydrate in the ballooned axons. Electron lucent material we observed was not described in the previous papers on this condition. We added one more example showing that nerve biopsy is helpful to confirm the diagnosis in infantile neuroaxonal dystrophy.

The paper describes the clinical and morphological features of a congenital neurological disease affecting two in-bred litter-mate kittens. The principal neurological features were ataxia and dysmetria. In one of the kittens light microscopy revealed widespread vacuolation of white and grey matter of the brain and spinal cord. Electron microscopy revealed intra-myelinic vacuolation and some expansion of the extracellular space. Neuronal, axonal and glial changes were not seen, nor was there evidence of myelin breakdown. The entity is compared with congenital brain oedema of calves and spongy degeneration of the CNS in man.

This paper reports on the study of a symptomless fusiform enlargement of the superficial peroneal nerve. The swelling was located in the part of the nerve passing through the aponevrosis. On incision of the epineurium small swellings were seen in the nerve fascicles. A fascicular biopsy was done and the fascicles studied by teasing and by optic and electron microscopy. Isolated nerve fiber study gave evidence of segmental demyelinisation with subsequent remyelinisation in almost all the myelinated fibers. These abnormalities were only encountered in the swollen part of the fascicle. A striking proliferation of cells was demonstrated in isolated fibers by counter-staining with hematoxylin. Electron microscopy showed primary demyelinsation and cellular proliferation affecting Schwann-cells (without onion bulb formations), fibroblasts and giant-vacuolated histiocytes. There was also a massive increase of endoneurial fluid. A few Büngner bands were seen. These rare abnormalities appear to be caused by chronic irritation of the nerve in its passage through the aponebrosis.

This review paper deals with the transport of the protein tracer horseradish peroxidase across cerebral vessels under normal and various experimental conditions.

The brain lesions in spontaneously hypertensive stroke-prone rats (SHRSP) are characterised by multifocal microvascular damage, breakdown of the blood-brain barrier, massive extravasation of plasma constitutents and severe brain oedema, with consequent spongy and cystic tissue destruction in the cerebral cortex and basal ganglia as well as loosening of the white matter. In this paper we analyse in greater detail the pathogenetic mechanisms by which the spongy and cystic lesions are formed and the response of astrocytic cells. For this purpose, tracer (Evans blue)-stained brain lesions were examined in 8-month-old SHRSP immunohistochemically and electron microscopically. Sponginess of the neuropil in small lesions and at the periphery of larger lesions was due to swollen neuronal and astrocytic cell processes, i.e.at this stage the oedema was mainly intracellular. Cystic lesions were formed in the grey matter both by expansion of the extracellular space (ECS) containing protein-rich ocdema fluid, and by rupture and subsequent loss of massively swollen cellular elements. In the white matter small slit-formed cysts along the fibre tracts were also formed by the expansion of ECS. In apparently recent lesions astrocytes displayed cytoplasmic oedema but otherwise were still fairly normal. In more chronic lesions increased numbers of enlarged astrocytes with prominent staining for glial fibrillary acidic protein were present. Their distribution corresponded well to the spread ofoedema, i.e. they were prominent around the leaky vessels in the grey matter, in the subpial zone and in the white matter. In the reparative phase the grey matter cysts became lined by astrocytic processes, a new glia limitans. Profuse sheets of glial processes in the neuropil around the cysts reestablished the compactness of the brain parenchyma.

Axonal dystrophy in normal ageing can be studied in experimental animals. Primary sensory neurones show two different kinds of change with ageing, i.e. axonal dystrophy and axonal atrophy (degeneration). This paper reports the chronology and topography of these two processes in relation to growth and involution of these neurones throughout the lifespan of the rats used in this study. Axonal spheroids preferentially form at presynaptic terminal regions in many of the collaterals of central branches of the axons, i.e. in the posterior funiculus nuclei, posterior column and posterior funiculus. Axonal dystrophy in normal ageing is essentially a morbid process restricted to the terminal parts of the axon. It shows little tendency to expand retrogradely along the axon. Evidence is presented that spheroids in posterior funiculus also derive from terminal axons. Preference is also noted in the lumbosacral rather than cervical neurons, and in longer (posterior funiculus nuclei) rather than shorter (posterior column) collaterals. Quantitative study of myelinated fibres in posterior funiculus shows that they increase in number until middle age (400 days) of the animals, before beginning to decline. On the other hand, axonal atrophy begins to appear early in small numbers, and increases in numbers with age. Atrophy involves the whole length of the axon within the posterior funiculus from the start, suggesting, therefore, that it does not belong to a dying-back process. It is noteworthy that the main development of axonal dystrophy lies in the earlier half of the animals' life, while that of axonal atrophy lies in the latter half. This fact adds to the evidence that axonal dystrophy, as far as in normal ageing is concerned, is more related to the positive side of neuronal activity, e.g. one form of growth abnormality of axon.

In this paper, the characterization of four human malignant glioma cell lines is described. The four lines are positive for glial fibrillary acidic protein (GFAP) in variable amounts. One of them, LN 992, is positive for S-100 protein. Myelin basic protein could not be detected in any of the four lines. The four lines had high levels of CNPase activity. The karyotype shows polyploidy for all lines, with modal numbers ranging from 80 to 120 and various numbers of marker chromosomes. Particular attention has been paid to the surface phenotype and a panel of three antiglioma monoclonal antibodies (Mabs), five antimelanoma Mabs, one anti-CALLA Mab, and two anti-HLA-DR Mabs has been used in an antibody-binding radioimmunoassay for the four cell lines. Lines LN 215 and LN 235 are positive with two antiglioma Mabs, LN 992 is negative. The four lines are positive with all five antimelanoma Mabs, except for LN 992 which ist negative with Mab D5. LN 992 and LN 215 are positive with the anti-CALLA Mab N2A12. LN 308 and LN 992 are positive with anti-HLA-DR Mab D4-22. There was no correlation between the in vitro morphology of the lines and the expression of the various biochemical or surface markers. These results stress the heterogeneity of the phenotype of human malignant glioma lines. These lines will be useful tools for further immunologic studies.

The lesions of scrapie are confined to the CNS, and the most characteristic histopathological change in mice terminally infected with scrapie is vacuolation. With most laboratory strains of scrapie, one of the regions affected by this lesion is the cerebral cortex, including the hippocampus. Under some circumstances, however, a more destructive degeneration occurs in the hippocampus, with pyramidal cell necrosis accompanied by glial reactions, which can extend to a severe hippocampal sclerosis especially when an intracerebral route of infection has been used. The purpose of this paper is to identify some of the factors involved in these differences in the pathology of the hippocampus and their interdependence; this has necessitated the development and use of a scoring system for sclerosis in the hippocampus, in conjunction with an already established scoring system for vacuolation. Comparison of average hippocampal sclerosis scores and the vacuolation index (an estimate of the severity of grey matter vacuolation throughout the brain) reveals that hippocampal sclerosis is generally associated with scrapie models which produce intense vacuolation in the hippocampus, and also in the brain as a whole. Scrapie-induced hippocampal sclerosis provides an experimental system for investigating the basis for similar lesions, which occur in a variety of conditionsm, such as Alzheimer's disease and epilepsy.

In spite of several cases reported in the literature, the exact pathogenetic mechanism of neuropathic changes in porphyric neuropathy remains uncertain. Various authors have ascribed the neuropathologic findings to either a dying-back axonal degeneration or segmental demyelination. In recent years, the hypothesis of an axonal and myelinic disorder has received support by the demonstration of a combined and simultaneous involvement of both these structures. Such different opinions are also a consequence of the reduced number of detailed bioptic observations in the different forms of acute porphyria not only during acute phases but also between attacks. In this paper we report the results of light- and electronmicroscopic examination of two sural nerve biopsies from subjects with hereditary coproporphyria. The first was performed 6 months after an acute attack, the second specimen was obtained from a patient without acute attacks, who had clinical and electrophysiologic signs of a chronic progressive neuropathy. In both cases a dying-back axonal degeneration is considered the primary change. The pathogenetic mechanism of peripheral nerve lesions in porphyric neuropathy will be discussed finally.

Most studies on lead toxicity in the suckling rat have been performed with doses leading to growth retardation. In a previous paper (Sundström et al. 1983), the effects of different lead doses on normal suckling rats were described. The dose of 10 mg/kg body weight daily given on days 1–15 pp produced minute hemorrhagic lesions on day 15 in the cerebellum, whereas rats given 5 mg/kg body weight daily lacked microscopically discernible pathologic changes in the brain. None of these groups exhibited growth retardation.

Antisera to isolated Alzheimer neurofibrillary tangles (ANT) of paired helical filaments (PHF) were raised in rabbits. These anti-PHF sera immunolabeled both ANT in sections of Alzheimer hippocampus and ANT which were isolated and extracted with sodium dodecyl sulfate (SDS). The immunostaining of ANT in tissue sections was removed by absorption of the anti-PHF serum with small amounts of PHF and also with 40-fold the amount of a fraction prepared identically from normal brain; neurofilament and brain microtubule preparations used at the same concentration as the normal brain control fraction did not eliminate the tangle staining. Furthermore, the tangle staining was also not removed with glial filaments or actin and myosin filaments. No labeling of the neurofilaments of axons and cerebellar basket fibers by anti-PHF sera was observed in tissue sections from non-neurologic brain. On paper blots of SDS-polyacrylamide gels anti-PHF serum reacted with neither polypeptides of the normal brain control fraction nor major microtubule and neurofilament polypeptides. However, the immunoblots of PHF preparations with the anti-PHF serum revealed staining of several polypeptide bands in the 45,000–70,000 molecular weight (MW) region, material on top of the gel and diffuse staining of the high MW region. The tangles staining in tissue sections by the anti-PHF serum was abolished by its absorption with PHF polypeptides extracted from high and low molecular weight areas of SDS polyacrylamide gels but not with identically prepared neurofilament polypeptides. These results indicate that (1) the antigen(s) recognized by the anti-PHF serum is inherent to the PHF, (2) this PHF polypeptide(s) is at least partly soluble in SDS, and (3) this polypeptide(s) occurs in normal brain but is not associated with microtubules, neurofilaments, actin, or myosin.

This paper reports the case of a 16-year-old girl with acute lymphoblastic leukemia who received chemotherapy including intrathecal injections of methotrexate and preventive irradiation of the brain, but not of the spinal cord. Several months later, she died from an acute ascending poliomyelitic syndrome evolving during 10 days. Clinical, bacteriological, and viral investigations failed to demonstrate any pathological agent.

This field is meagerly represented in the literature. The aim of this paper is to check in man the descriptions which for the most part were made in animals.

Aluminum has been presumed to be involved in the pathogenesis or etiology of Alzheimer's disease. Histochemical demonstration of aluminum in autopsy brains from Alzheimer's disease victims by means of the solochrome azurine method in combination with the methenamine silver technique revealed aluminum-related staining in some neocortical and hippocampal senile plaques and tangles, as well as in the cytoplasm and/or the nuclei of some neurons, and in the cytoplasm of endothelial cells of blood capillaries and pericytes around larger blood vessels. In double-stained samples (first with methenamine silver and then with solochrome azurine) only some plaques displayed the presence of aluminum, while others did not show any sign of the presence of the trace metal. The specificity and sensitivity of solochrome azurine staining was checked in paper spot-test and test-tube experiments combined with flameless atomic absorption spectrophotometry. The results suggest that aluminum is present in brain samples from Alzheimer's disease victims, but the structural localization indicates that it is not primarily involved in the etiology of the disease.

The presence of connective tissue elements in gliomas necessitates in every case a thorough analysis of the character and derivation of such elements to allow the formulation of an appropriate diagnosis. Four cases are presented in this paper. In cases 1 and 2 (anaplastic astrocytomas in two children, 9 and 4 years old, respectively) all the neoplastic elements were astrocytes and their ability to produce or indirectly promote the production of reticulin and collagen fibers accounted for the presence of such elements in close association with the tumor cells. The term “gliofibroma” has been coined for such tumors, but “desmoplastic astrocytoma”, (low grade or anaplastic) or in highly malignant cases “desmoplastic glioblastoma”, as the case may be, also seem to be appropriate terms for such neoplasms. In contrast, cases 3 and 4 represented composite tumors in adults (66 and 58 years old, respectively) and the neoplasms of these patients consisted of glioblastoma and sarcoma, the latter component demonstrably being of vascular origin. This is the type of tumor usually referred to as gliosarcoma or “Feigin tumor”. Although some apparent similarities between the two groups may exist at times, the histogenesis of the latter group's sarcomatous or sarcoma-like portions is different from that of the first group and, therefore, warrants separate diagnostic terms and placement in brain tumor classification.

This paper deals with a girl who at birth had a large retroauricular mass diagnosed clinically as hemangioma. It responded well to X-ray therapy. When she was 11 years old, a sarcoma was removed from the cerebellum. No evidence could be found that the sarcoma had originated from the retroauricular tumor. After the use of nitrogen mustard locally and after three courses of X-ray therapy to the tumor over a period of 9 1/2 months — a total radiation dose of approximately 7,953 r — the patient was growing moribund. During 4 neutron-capture treatments, which were directed chiefly toward the suboccipital region, striking improvement occurred — to such an extent that the patient was able for a time to sit up in a wheelchair and converse. As a result of the therapy, all tumor which had spread suboccipitally and into the neck vanished, as did also virtually all tumor in the dorsal third of the cerebellum, i.e., in the region receiving the largest concentration of thermal neutrons. In the middle third of the cerebellum large and small tumor aggregates, some of them calcified, were necrotic and were walled off by hyperplastic connective tissue. In the ventral third of the cerebellum, in a region presumably out of the range of an effective concentration of thermal neutrons, the tumor grew unimpeded.

This paper describes nine cases of a parenchymatous peripheral neuropathy in dogs, characterized clinically by posterior ataxia and paralysis, and pathologically by widespread myelin and axon destruction in ventral spinal and peripheral nerves, together with disappearance of ventral horn neurones. It is discussed in relation to nutritional and other peripheral neuropathies seen in man and animals.

Four cases of S.S.L.E are reported. The electron microscopy findings show: 1. Tubulary inclusion bodies: They appear in three cases out of four, either in neuronal and glial nucleus or in axis cylinders. Their morphological features are similar to the nucleocapsides of myxoviruses and particularly measles-virus. 2. Other different types of nonspecific inclusions: nuclear bodies, cristalline-like rods and fibrillar bundles which may be considered as the result of a nuclear metabolic disorder, osmiophilic particles which may be seen as the result of a cellular intracytoplasmic hyperactivity. The tubules are found whatever the duration of the disease (3 months up to 5 years) may be. This might indicate that there is no autosterilization of the virus in the C.N.S. during the course of S.S.L.E. According to the most recent papers, such a disease might be interpreted as an infection indirectly induced by measles-virus with an unknown immunologic or metabolic mechanism.

This paper describes two cases of a progressive incoordination in Jack Russell terriers. Histologically the entity was characterised by widespread Wallerian-type degeneration of the brain and cord, together with focal symmetrical demyelination of the dorsolateral and ventromedial columns of the cord. One dog also showed severe ballooning of myelin sheaths in the dorsal and ventral spinal nerves and oedema and fibrosis of the sciatic nerve. Both dogs also showed degenerative changes of the central auditory pathways.

This paper describes a neurovisceral cytoplasmic storage disease together with neuroaxonal dystrophy and dysmyelinogenesis in two of three new born goats affected with an arthrogryposis-like syndrome. The entity is compared with other conditions in which no substance can be demonstrated in cytoplasmic vacuoles.

There have been several recent descriptions of myopathies associated with disordered oxidative metabolism in muscle fibres and particularly with accumulation of fat within the fibres. Some of these have been associated with abnormal muscle mitochondria but in others there may be an extramitochondrial defect of lipid metabolism. In this paper we describe a 38 year old man suffering from a progressive myopathy which clinically resembled polymyositis and which responded to treatment with steroids. Pathologically the condition was characterised by an apparent increase in the amount of lipid within the muscle fibres, an observation subsequently confirmed by quantitative chemical analysis, although the muscle mitochondria appeared to be normal. This case closely resembles others recently described in this department and elsewhere and it is suggested that they may be examples of a previously unrecognized clinico-pathological entity.

The data with which this paper deals were obtained from white rats receiving limited head X-irradiation, tested for behavioral changes, and sacrificed for light and electron microscopic evaluation 1 year after the irradiation. No evidence was found for a general loss or change in cortical or subcortical neurons. On the other hand, there was bilateral focal degeneration in the fimbria of the fornix in the dorsal hippocampus. This involved considerable numbers of pyramidal and granule cells, presumably secondary to delayed vascular changes. Widespread hypertrophy of astrocytes was noted throughout the irradiated zone. Within each central necrotic zone invasive collagen, reticulin and fibrin were present. In general, blood vessels showed only occasional evidence of thickening. However, the blood vessels in the areas of frank necrosis in the fimbria and internal capsule exhibited intense thickening leading to hyalinization.

This paper deals with the first ultrastructural study of muscle fiber in a child affected by infantile neuroaxonal dystrophy or Seitelberger's disease. In a first step, diagnosis was performed by light and electron microscopy in biopsy and autopsy findings in central and peripheral nervous system. Muscle fiber and axonal changes are very similar. The ultrastructure findings in muscle fiber are as follows: 1. neural atrophy, 2. overproduction of membrano-tubular structures related to sarcoplasmic reticulum hyperplasia, 3. filamentous aggregates by presumed overproduction of myofilaments, 4. overproduction of abnormal mitochondria. These changes, already described in various muscular diseases, are not specific; they seem related to an abnormal muscle fiber reaction in close association to dystrophic axonal endings.

This paper describes the neural and extra-neural lesions seen in cattle, sheep and a horse associated with the ingestion of species ofSwainsona. The neural lesions consist of widespread watery cytoplasmic vacuolation of large neurones together with many spheroids (neuroaxonal dystrophy) and abnormal amounts of a lipofuscin-like pigment. Similar foamy vacuolation involves the choroid plexus, the exocrine panreatic parenchyma, the renal convoluted tubules and other viscera. The lymph nodes contain foamy macrophages in medullary sinusoids and/or much intracellular lipofuscin-like pigment.

In this paper enzyme activities in cylindric structures from striated muscle fibers of the beige mutant mouse are described. While most of the sarcoplasm possesses a reaction for myosin and sarcoplasmic reticular ATPase, succinic dehydrogenase, and lactic dehydrogenase similar to that described for normal non-mutant mice, the cylinders are totally free from activity of these enzymes. The staining pattern thus resembles earlier reports of the central core disease in humans and suggests that the beige mouse is a suitable animal model for this myopathy.