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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 86 (1993), S. 378-385 
    ISSN: 1432-0533
    Keywords: Photochemical infarction ; Blood-brain barrier ; Brain edema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The importance of protein extravasation for the development of vasogenic brain edema is still controversial. We, therefore, assessed the cerebrovascular permeability to serum proteins in relation to the development and resolution of brain edema in a photochemical cortical lesion in the rat. Cortical infarction was induced by in situ thrombosis using an argon laser beam aimed at the exposed parietal bone in animals given rose bengal i.v. The histology and the cerebrovascular permeability to serum proteins were scrutinized from 2 h to 3 weeks after the insult. The presence of serum proteins was demonstrated by an immunoperoxidase technique. The cerebral water content was estimated by specific gravity measurements of the cortical tissue in a kerosene-monobromobenzene gradient column from 2 h to 7 days after infarction. The blood-brain barrier was permeable to proteins at 2 h following the insult and proteins spread into the medial and lateral tissue reaching a maximum at 24 h. The specific gravity did not deviate from control values at 2 h. After 8 h the specific gravity of the lesion decreased with smaller decreases in the immediately afjacent tissue. At 24 h the changes in specific gravities reached a maximum in all regions except the immediately lateral area. The edema was generally worse in tissue medial to rather than lateral to the infarct. The degradation of serum proteins and the resolution of the brain edema followed the same time course with partial resolution of 72 h. By 1 week serum proteins and edema were confined to the central necrotic core. The results suggest a relationship between cerebrovascular permeability and cerebral edema in photochemical cortical infarction.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 51 (1980), S. 65-70 
    ISSN: 1432-0533
    Keywords: Morphometry ; Glial cells ; Portocaval anastomosis ; Ultrastructure ; Corpus striatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of astrocytes and oligodendrocytes was investigated in rats 10 days, 30 days, and 10 weeks after portocaval anastomosis (PCA). Cell and nuclear sizes were measured by planimetry on randomly sampled cells magnified×24,000. The volume fractions of mitochondria, glia fibrils, and lipofuscin granules were measured in astrocytes by electronic image analysis. The mitochondrial profile area distribution and oligodendrocyte mitochondrial content were likewise estimated. All PCA animals had an increased astrocyte cell and cytoplasmic area, and after correction for cytoplasmic edema all groups had an enhanced mitochondrial fraction and mitochondrial number. The mitochondrial sizes were increased in all PCA groups. The mitochondrial profile area distribution curves did not suggest more than one group of mitochondria. All PCA groups had increased fractions of lipofuscin granules and glia fibrils. The oligodendrocytes had a slight fall in cell, nuclear, and cytoplasmic area after 30 days of shunting, and the mitochondrial fraction was diminished. After 10 weeks of PCA, all changes were reversed to normal values. It is concluded that the astrocytes are the active cells in the brain metabolism of ammonium. The oligodendrocytes seem to be dependent on neuronal integrity and do not contribute to the brain ammonium metabolism. The increase in astrocyte lipofuscin granules content may be explained by a beginning neuronal loss.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford UK : Blackwell Science Ltd.
    Journal of neurochemistry 73 (1999), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract : N-Acetylaspartate (NAA) is the second most abundant amino acid in the adult brain. It is located and synthesized in neurons and probably degraded in the glia compartment, but the transport mechanisms are unknown. Rat primary neuron and astrocyte cell cultures were exposed to the L isomer of [3H]NAA and demonstrated concentration-dependent uptake of [3H]NAA with a Km≈80 μM. However, Vmax was 23 ± 6.4 pmol/mg of protein/min in astrocytes but only 1.13 ± 0.4 pmol/mg of protein/min in neurons. The fact that neuron cultures contain 3-5% astrocytes suggests that the uptake mechanism is expressed only in glial cells. The astrocyte uptake was temperature and sodium chloride dependent and specific for l-NAA. The affinity for structural analogues was (IC50 in mM) as follows : l-NAA (0.12) 〉 N-acetylaspartyglutamate (0.4) 〉 N-acetylglutamate (0.42) 〉 l-aspartate (〉1) 〉 l-glutamate (〉1) ≥dl-threo-β-hydroxyaspartate 〉 N-acetyl-l-histidine. The naturally occurring amino acids showed no inhibitory effect at 1 mM. The glutamate transport blocker trans-pyrrolidine-2,4-dicarboxylate exhibited an IC50 of 0.57 mM, whereas another specific glutamate transport inhibitor, dl-threo-β-hydroxyaspartate, had an IC50 of 〉1 mM. The experiments suggest that NAA transport in brain parenchyma occurs by a novel type of sodium-dependent carrier that is present only in glial cells.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-2307
    Keywords: Immunohistochemical markers ; Flow cytometry ; Ploidy ; S phase fraction ; Shimada classification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 42 tumour samples of human neuroblastoma, histological classification by differentiation (Shimada) was significantly correlated with strong positivity for neuron-specific enolase (NSE) and inversely correlated with rosette formation. Most ganglioneuroblastomas were positive for S-100 protein and reacted strongly with NSE antibody. Histological signs of high proliferative activity included intermediate or high mitosis-karyorrhexis index, necrosis and lack of calcification, which were significantly correlated with each other. Flow cytometric DNA analysis demonstrated that 88% of the tumour samples had DNA aneuploid stem lines. High S phase fraction (〉-0.20) was significantly correlated with necrosis and lack of calcification. Univariate analysis of prognosis for 26 patients whose tumour samples were obtained before adjuvant treatment showed that five factors were significantly related to a better outcome: early stage of the disease (stages I, II, IV-S), S phase fraction 〈0.20, favourable Shimada histology, positivity for S-100 protein, and strong positivity for NSE. In multivariate analysis, only S phase fractionor stage of disease remained significantly associated with prognosis. DNA index did not correlate with prognosis in this study.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 32 (1995), S. 255-262 
    ISSN: 1059-910X
    Keywords: Cavalieri's principle ; Length density ; Morphometry ; Stereology ; Surface density ; Vertical sections ; Vertical slices ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: We compare the effectiveness of morphometric methods for extimating lung parameters. Various stereological methods are applied on human lungs and described in detail. The lung volume was estimated by Cavalieri's principle and by fluid displacement. But methods are reliable, but Cavalieri's principle is superior when systematic sections are needed or when volumes of parts of the lung are wanted. Point counting demonstrated that 87.5% of the lung is parenchyma, 5.4% is vessel volume, and 7.1% is bronchia volume. Alveolar surface was estimated on vertical and isotropic uniform random tissue (IUR) sections. The capillary length and length density was estimated on projected images of vertical slices (Gokhale method) and on IUR sections. Only minute differences were found whether IUR sections or vertical sections were used. Of the total variation, approximately 2% was due to the stereological variation and approximately 98% was due to the biological variation on IUR sections and vertical sections. Estimates for volumes, surfaces, and lengths coming from model-based and design-based methods gave similar results for human lungs. In our hands, the design-based methods were easier to use and required less time. However, only the design-based methods offer the guarantee of an unbiased estimate. © 1995 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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