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Biomedical subjects

P Sourander

Publications and source records attributed to P Sourander.

At least 55 records · Page 3Linked to original sources
PubMed1982

The influence of protein deprivation during development on amino acid incorporation into cerebral proteins.

The incorporation of 3H-valine into protein of cerebrum, liver, and muscle was studied in rats fed a low protein diet. Animals, 15-50 days old, were used to cover the period during and after the most rapid phase of cerebral protein synthesis. The precursor was administered in doses resulting in brain concentrations of free valine in the 0.1-0.3 mM range. Two series of experiments were run and the injected dose varied for comparison of protein synthesis at different concentrations of precursor valine. By concomitant amino-acid analysis it was shown that the concentration of other amino-acids in the brain was not changed by the injected valine. The changes in the amino-acid pool with age in control rats were in agreement with previous findings. Only small alterations were seen in the amino acid pool as an effect of protein deprivation, the results being consistent with those of some previous reports. Uptake of valine into the brain appeared to be decreased only in 15-17-day-old protein-deprived rats. Valine incorporation into cerebral protein was decreased in the youngest age group but no effect was seen in older animals. Liver protein incorporation was slightly decreased by low protein diet but a marked reduction was observed for muscle protein. The changes in brain protein synthesis during normal development were in agreement with previous studies and differed qualitatively from those in liver and muscle.

Aging↗
PubMed1981

Storage of lipofuscin in neurons in mucopolysaccharidosis. Report on a case of Sanfilippo's syndrome with histochemical and electron-microscopic findings.

A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.

Adult↗
PubMed1981

Infantile bilateral striatal necrosis. Clinical and morphological report of a case and a review of the literature.

A case of infantile bilateral striatal necrosis (IBSN) is reported, the first one found in Scandinavia. Extensive clinical and laboratory investigations did not reveal any evidence of a neurometabolic disease. By computed tomography (CT) degeneration of putamen of either side was detected. The neuropathologic findings included extensive bilateral destruction of the striatum and pallidum and degeneration of the substantia nigra and tegmental nuclei. In the damaged regions, accumulations of cells containing sudanophilic lipids were found and Alzheimer type II glial cells, which were also seen in the cortex. On the basis of the clinical picture and the destruction of nerve cells in particular areas of the brain, in the present case and previously published cases of IBSN, the possible role of glutamate and other excitotoxic transmitters in the pathogenesis of the disease is discussed.

Brain Diseases↗
PubMed1981

A new type of non-progressive sensory neuropathy in children with atypical dysautonomia.

Three cases of non-progressive, sensory neuropathy with dysautonomia are presented. Light and electron microscopy on whole sural nerve biopsies revealed an almost total lack of myelinated nerve fibres. The total fibre count was also reduced as was the total number of Schwann cell nuclei. No degenerative phenomena were seen within the nerve fibres. The aberrations are probably caused by a maldevelopment of the neural crest implying a stunted proliferation and growth of sensory and autonomous neurones as well as a reduced proliferation of Schwann cells. Since the morphology and clinical features differ from that in other cases of sensory neuropathy with dysautonomia the three present cases are considered to represent a new type of the disease.

Biopsy↗
PubMed1979

Effects of local extraneural application of diphtheria toxin on the sciatic nerves of normal and protein deprived rats.

Diphtheria toxin was locally administered around the sciatic nerves of normal and protein deprived rats aged 3, 6, 12, and 26 weeks in order to investigate the permeability of the barriers enveloping the nerves. At all ages the rats developed a reversible hind limb paralysis linked to a severe segmental demyelination, indicating passage of the toxin into the endoneurium. From 6 weeks of age the pattern of reaction differed between the protein deprived and control rats. The differences are interpreted as being partly dependent on less efficient protective barriers of the sciatic nerves of the protein deprived rats.

Animals↗
PubMed1978

Barriers of peripheral nerve towards exogenous peroxidase in normal and protein deprived rats.

The protective barriers of the sciatic nerve in protein deprived and normal rats have been studied. Horseradish peroxidase (HRP) was applied extra-neurally in rats aged between 4 and 26 weeks. The spread of the tracer was investigated 2 h, 24 h, and 3 days after application. Passage of tracer into the endoneurium was found in all rats but decreased with age. Within the endoneurium, HRP was phagocytized by normally occurring endoneurial histiocytes, which constitute part of the protective barrier system of peripheral nerves. The functional development of the nerve protective barriers was retarded in protein deprived rats. Observations made in this study support the concept of a transperineurial vesicular transport of macromolecules.

Animals↗
PubMed1978

The effect of pre- and postnatal undernutrition on axonal growth and myelination of central motor fibers. A morphometric study on rat cortico-spinal tract.

A morphometric study of the axon circumference and myelin sheath thickness in the rat corticospinal tract was undertaken to establish the effect of pre- and postnatal undernutrition and subsequent nutritional rehabilitation. Both axonal growth and myelin deposition were affected by undernutrition. Rats subjected to postnatal nutritional rehabilitation revealed a catch-up in axonal growth; whereas the process of myelination remained affected.

Animals↗
PubMed1978

The development of sexual behavior in the rat: role of preadult nutrition and environmental conditions.

Rats were subjected to pre- and postnatal undernutrition by restricting the food intake of their mothers (U); another group of rats was normally fed (N). Each nutrition group was divided into 3 subgroups by varying the degree of environmental stimulation: animals in the Max group were stimulated by handling and enriched rearing conditions; the Min group rats were subjected to social isolation; rats in the control condition (C) were raised under ordinary laboratory conditions. The onset of sexual activity was not affected in the U-C male rats, but was delayed in both U-Min and N-Min rats. Although no difference existed in the age of puberty between the N-Max and N-C animals, the U-Max rats displayed an advancement of puberty by 7 days in comparison to the U-C rats. Undernutrition did not affect female sexual maturation; however the Max condition delayed this process in both nutrition groups.

Animals↗
PubMed1978

The influence of early protein-calorie malnutrition on neuronal and glial protein synthesis. An experimental study on rats.

The effect of pre- and postnatal undernutrition, produced according to the method of Chow and Lee (3), on the rate of protein synthesis in the brains of rats 11, 21, 34 and 90 days of age was studied by measuring the incorporation of L-[14C]valine in vivo and L-[3H]lysine in vitro. Both in vivo and in vitro experiments were performed with high concentration of the precursor to decrease the effects of pool variations and protein degradation. Particular interest was given to the effects of this form of early protein-calorie malnutrition (PCM) on neuronal and glial cells which were isolated from the brains by gradient centrifugation. Brain protein synthesis measured in vivo which showed a peak at 21 days in both animal series, was depressed by PCM at 11 days but stimulated at 34 days of animal age. Small effect was observed in the 90-day-old animals. A similar response as in whole brain was seen for neuronal cells, while glial cells showed a different reaction. Studies of in vitro protein synthesis did not reveal appreciable effects of undernutrition in whole brain. Both neuronal and glial cells showed a moderate but not statistically significant elevation of protein synthesis in animals subjected to early PCM.

Animals↗
PubMed1978

Postnatal differentiation and growth of skeletal muscle fibres in normal and undernourished rats. A histochemical and morphometric study.

The postnatal differentiation and growth patterns of the different histochemical muscle fibre types were studied at frequent age intervals in the extensor digitorum longus (EDL) muscle of normal rats and animals subjected to pre- and postnatal protein-calorie undernutrition. Three stepwise changes were seen in the fibre type composition of the EDL muscle during maturation. In newborn normal rats 2 histochemically and morphometrically distinct fibre populations occurred: small foetal type (type F) fibres or myotubes (about 90%), with the staining characteristics of the so-called type 2C fibres, and larger type 1 fibres (10%). At 5 days of age the percentage of type F fibres had dropped to 50 simultaneously with the emergence of a new population (40%) of type 2B fibres, intermediate in cross-sectional area between the remaining type F fibres and type 1 fibres. Between 15 and 20 days the small type F fibres practically disappeared with the emergence of a corresponding percentage (40%) of type 2A fibres, smaller than both type 1 and type 2B fibres; Between 20 and 60 days the percentage of type 1 rose from 10 to almost 30, type 2B fibres correspondingly diminishing in number but growing at a faster rate than either type 1 or type 2A fibres. In the undernourished rats the histochemical differentiation was retarded at birth, all fibres or myotubes being of the foetal type; However, large type 1 and type 2B fibres were seen at the age of 5 days and the histochemical maturation proceeded almost normally at later stages. On the other hand, at all ages there was a proportional reduction in the cross-sectional area of all fibre types, amounting to about 50% at 180 dyas, and not fully restituted by nutritional rehabilitation. These observations suggest that type F (type 2C) fibres are the undifferentiated precursors of all mature muscle fibres, their stepwise histochemical transformation raising the question of maturational differences in the different types of motoneurones.

Adenosine Triphosphatases↗
PubMed1978

Neurovisceral storage disorder simulating Niemann-Pick disease. A new form of oligosaccharidosis?

Two sisters are described with demonstrable splenomegaly already from infancy and, after the age of 2--4 years, signs of slowly progressive encephalophy, vacuolated lymphocytes in the peripheral blood, and peculiar foam cells in the bone marrow aspirates. The died at 7 3/4 and 6 1/2 years. Widely spread in the brain, the nerve cell bodies were found to show extensive ballooning. It was most striking in the brain stem and spinal cord, while cerebellar structures were remarkably well preserved. The cytoplasm of the ballooned nerve cells was filled with finely granular storage material stainable as a readily soluble glycolipid. The spleen, liver and intestinal wall contained numerous foamy PAS-positive macrophages. Chemical assays showed a ten-fold increase of lactosylceramide and a modest one of minor gangliosides brain cortex. No accumulation sphingomyelin could be revealed, and the sphingomyelinase activity was found to be normal. The ganglioside GM1 beta-galactosidase activity of leucocytes was reduced to 20--25% of normal, which indicated a disturbance of the glycosaminoglycan metabolism. The tissue content of glycosaminoglycans was, however, normal, but an accumulation of lactose was demonstrated in the spleen. It is postulated that the primary enzymic defect is a disturbance of a lysosomal beta-galactosidase with a substrate specificity for lactose and other oligosaccharides with a terminal beta-galactosidic linkage.

Bone Marrow↗
PubMed1977

Glial cell characteristics in bulk-prepared cell fractions from human brain tumours.

The heterogeneity of brain tumours, especially in the glioblastoma group, makes biochemical characterization of pieces of the tumours hazardous even with extensive histological controls. This study employs a technique by which separate cell populations are subsequently isolated from the tumours by means of density gradient centrifugation. Cells isolated from glial brain tumours with low density sedimentation rates show the highest levels of glial cell characteristics, i.e. S-100 content and active uptake of the neurotransmitter GABA.

Astrocytoma↗
PubMed1977

Hereditary multi-infarct dementia. Morphological and clinical studies of a new disease.

A family is described in which for three subsequent generations numerous individuals were affected with a progressive neuropsychiatric disease with pyramidal, bulbar and cerebellar symptoms, relapsing course and gradually evolving severe dementia. Post-mortem studies performed on three siblings afflicted with the disease suggest that the remarkably uniform macroscopic picture of the cerebral changes consisting in multiple small cystic infarctions, particularly localized to the central grey and white matter and pons as well as the cortical and central brain atrophy, is caused by an occlusive disease of small intracerebral and leptomeningeal arteries and arterioles. Collected pertinent information concerning the affected family members shows that the illness begins in early adulthood (at 29--38 years of age), affects both sexes and generally lasts for 10--15 years. The only exception so far noticed was a second generation descendant of one of the siblings. This patient died about 5 months after clinical onset of the disease in massive cerebral haemorrhage and showed similar vascular changes as the older members of the family. The disease is considered to be genetically caused and transmitted as a dominant autosomal character. For this apparently new nosological entity the eponym "hereditary multi-infarct dementia" is suggested.

Adult↗