Peripheral nervous system pathology in relapsing experimental allergic encephalomyelitis.

A recurrent type of primary demyelination was found in the anterior roots and dorsal root ganglia of strain 13 guinea-pigs with relapsing experimental allergic encephalomyelitis. Single nerve fibre studies revealed a predominant nodal--paranodal distribution of the destruction of myelin in these nerves. Damage of the Schwann cell--axolemmal junction was found in the majority of the abnormal nodes of Ranvier.

Chemical relationship of the paired helical filaments of Alzheimer's dementia to normal human neurofilaments and neurotubules.

Intraneuronal fibrillary tangles are prominent features of several neurological diseases, including especially Alzheimer presenile and senile dementia, and to a much lesser degree in the normal aged human brain. These tangles are made up of abnormal fibrillar elements each about 22 nm at its widest, periodically reduced to 10 nm at about every 80 nm. Each abnormal fiber seems to be a pair of 10 nm filaments helically wound around each other.

Arrest of myelination and demyelination in rabbit retina induced by herpes simplex virus infection.

Herpes simplex virus was injected into the vitreous of suckling and adult rabbits. In the suckling rabbits the infection caused an arrested myelination of the strip. Further, the infected strips showed degenerative changes with splitting and distension of myelin sheaths which then disintegrated.

Myelin deficiency in experimental phenylketonuria: contribution of the aromatic acid metabolites of phenylalanine.

Retarded body and brain growth and a deficit of myelin in the cerebral hemispheres and the cerebellum were observed in an animal model of phenylketonuria, the p-chlorophenylalanine and L-phenylalanine treated preweanling rat. These manifestations of phenylketonuria were reproduced in rats treated with phenylacetate in amounts approximating those likely to be produced in phenylketonuria. Young rats treated with equivalent amounts of other metabolites of phenylalanine, namely, phenylpyruvate, phenyllactate, and mandelate, which also accumulate in the brain during hyperphenylalaninemia, did not exhibit any toxic effects.

Chronic relapsing experimental allergic encephalomyelitis. Studies in vascular permeability changes.

The vascular permeability in the nervous system to Evans blue-albumin and horseradish peroxidase was studied in chronic relapsing EAE in strain 13 and Hartley guinea pigs. The disease was induced by single sensitization of immature animal and was characterized clinically by remissions and relapses. Recent and old demyelinating plaques in the spinal cord were present.

Salmonella in Commercially Produced Dried Dog Food: Possible Relationship to a Human Infection Caused by Salmonella enteritidis Serotype Havana.

Identification of Salmonella enteritidis serotype Havana, isolated from a 2½-month old female, engendered efforts to trace the source of infection. The inquiry led to examination of commercially prepared dehydrated dog foods. Twenty-five samples, representing four different manufacturers plus two retail store brands, were examined.

Liposome toxicity in the mouse central nervous system.

This study has shown that while some liposomes are highly toxic to the central nervous system, others, of different composition, are tolerated well in the dosage used (0.02-0.05 ml = 4-12 mg of lipid/inoculum).

Axonal degeneration in demyelinating disorders.

Changes in the L7 and S1 segments of the spinal cord and the corresponding dorsal root ganglia (DRG), spinal roots and sciatic nerves of guinea pigs immunized with whole rabbit sciatic nerve in complete Freund's adjuvant have been studied and compared with the changes found in guinea pigs immunized with purified P.N.S.

Studies on the encephalitogenic effects of purified preparations of human and bovine oligodendrocytes.

Bulk-isolated human and bovine oligodendroglia, practically free from myelin, have been used in attempts to elicit an autoimmune response which has been compared with acute experimental allergic encephalomyelitis (EAE). For these experiments, a total of 20 Hartley guinea pigs, 33 Lewis rats and 16 rabbits have been studied. Animals were inoculated with a range of doses of purified preparations of both human and bovine oligodendroglial cells in complete Freund's adjuvant (CFA) and compared with others challenged with whole white matter in CFA.

Penetration of protein tracers into the epiretinal portion of the optic nerve in the rabbit nerve.

Horseradish peroxidase and fluorescein-labelled globulin were injected into the vitreous of adult and 11- to 13-day-old New Zealand albino rabbits. Both tracers diffused rapidly into the myelinated nerve fibre layer (the "medullary rays"), which extends over a long distance within the retina in these animals. The tracers penetrated also for some distance into the optic nerve beyond the lamina cribosa, where they were incorporated into a large number of cells in the nerve.

Hydrocephalus: III. Reconstitution of the cerebral cortical mantle following ventricular shunting.

Adult cats with hydrocephalus were sacrificed at varying times following valveless ventricular shunting. This shunting resulted in a prompt reduction of ventricular size and rapid gross reconstitution of cortical mantle. Ultrastructurally it was evident that white matter edema persisted for many weeks, even in the presence of normal size ventricles.