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  • 1
    ISSN: 1432-0533
    Keywords: Key words Global cerebral ischemia ; Cardiac arrest ; Vasospasm ; Hypoperfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The present investigation was undertaken to study the ultrastructural morphology of brain blood vessels during vasospasm following total cerebral ischemia. Global cerebral ischemia was produced in rats by compression of the cardiac vessel bundle (i.e., cardiac arrest) using a metal hook that was introduced into the mediastinum. Ischemia lasted for 10 min with blood recirculation for 6, 12 and 24 h. Rat brains were perfusion-fixed and regions from the cerebral cortex and associated leptomeningeal vessels were evaluated by scanning and transmission electron microscopy. We noted three general vasoconstrictive responses in vessels of various sizes including veins and arteries. These alterations related to the smooth muscle cell arrangement associated with each constricted vessel including a circumferential, and longitudinal arrangement, or a combination of both types. Other features in the three types of vasoconstricted vessels included thickening of the vessel basement membranes with increased endothelial microfilaments and vesicular profiles. Our studies present evidence that ischemia of 10-min duration with blood reflow for 6, 12 and 24 h produces profound and variable vasospastic changes in some but not all vessels. These vascular alterations are thought to be caused in part by vasoactive substances released both by endothelial and blood cells and by perivascular cellular elements in response to the ischemic episode.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 83 (1991), S. 1-11 
    ISSN: 1432-0533
    Keywords: Complete brain ischemia ; Clinical death ; Cardiac arrest ; Cerebrovasculature ; Microcirculation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study was undertaken to ascertain the role of the microcirculation in the phenomenon of hypoperfusion following complete cerebral ischemia. The experiments were performed on rats under superficial ether anesthesia. Cerebral ischemia was induced by cardiac arrest for 3.5 or 10 min, with survival periods that lasted from 3 min to 7 days. A special metal hook-like device was inserted into the chest cavity at the third intercostal spaces for occluding the cardiac vessel bundle. The effect of this procedure was total cessation of systemic circulation, i.e., clinical death. In 52% of animals with 10-min clinical death, resuscitation (external heart massage and artificial ventilation) restored heart activity. When brain circulation was restored respiratory activity, pain reaction, corneal reflex, bioelectric activity of the cortex, and normal activities of the rats returned. Scanning electron microscopy was applied to study the effect of ischemia on the vessel wall and endothelial cells (EC). Ischemia produced a remarkable increase in the numbers of microvilli and pit-like invaginations on the luminal EC surface. The luminal wall surface of many of the microvessels (MV) formed ridges. Frequently, microthrombi of varying sizes were observed. The most prominent changes were noted from 3 min to 6 h of recirculation, and they correlated with hypoperfusion after ischemia. Seven days later, these changes completely disappeared. The data presented here indicate that progressive hypoperfusion after ischemia occurs with significant alterations fusion after ischemia occurs with significant alterations in the MV walls. These studies collectively suggest that the focal responses in select MVs may be associated with receptor molecule up-regulation of some, but not all, affected ECs. Our data provide further characterization of a new and unique chronic model of brain ischemia that can be applied to relevant clinical studies.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: Global cerebral ischemia ; Cardiac arrest ; Vasospasm ; Hypoperfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The present investigation was undertaken to study the ultrastructural morphology of brain blood vessels during vasospasm following total cerebral ischemia. Global cerebral ischemia was produced in rats by compression of the cardiac vessel bundle (i.e., cardiac arrest) using a metal hook that was introduced into the mediastinum. Ischemia lasted for 10 min with blood recirculation for 6, 12 and 24 h. Rat brains were perfusion-fixed and regions from the cerebral cortex and associated leptomeningeal vessels were evaluated by scanning and transmission electron microscopy. We noted three general vasoconstrictive responses in vessels of various sizes including veins and arteries. These alterations related to the smooth muscle cell arrangement associated with each constricted vessel including a circumferential, and longitudinal arrangement, or a combination of both types. Other features in the three types of vasoconstricted vessels included thickening of the vessel basement membranes with increased endothelial microfilaments and vesicular profiles. Our studies present evidence that ischemia of 10-min duration with blood reflow for 6, 12 and 24 h produces profound and variable vasospastic changes in some but not all vessels. These vascular alterations are thought to be caused in part by vasoactive substances released both by endothelial and blood cells and by perivascular cellular elements in response to the ischemic episode.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0533
    Keywords: Wilson's Disease ; Hepatogenic Encephalopathy ; Alzheimer's Cells Type I and II ; Opalski Cells ; Tissue Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Absicht der Experimente war es, in Gliagewebskulturen die für die Wilsonsche Krankheit und für die hepathogene Encephalopathie typischen Veränderungen zu erzeugen. Die Experimente wurden an Kleinhirnzellkulturen von neugeborenen Ratten durchgeführt. Das Standardmedium wurde ergänzt mit: 1. Serum von Patienten mit Wilsonscher Krankheit, 2. Serum von Patienten mit Leberkoma, 3. Kupferacetat, 4. Ammoniumchlorid. In allen Versuchsgruppen wurden typische morphologische Veränderungen an den Gliazellen beobachtet. Diese nahmen die Form von Alzheimer-Zellen des Typs I und II, Opalski-Zellen und intermediären Zellen an. Histochemische Abweichungen zeigten sich in Form von Anhäufung neutraler und saurer Mucopolysaccharide im Cytoplasma der Opalski-und Intermediärzellen mit einem begleitenden Abfall der SDH-und GDH-Aktivität sowie ein einer Zunahme der G6PDH und sauren Phosphatase-Aktivität. Der mögliche pathogenetische Mechanismus dieser Veränderungen wird diskutiert. Die Autoren vermuten, daß sowohl Kupfer als auch Ammoniak eine Schädigung der intracellulären Enzymketten des Kohlenhydratstoffwechsels bewirken. Diese Schädigung führt zu einer Anhäufung von Mucopolysacchariden in den Gliazellen.
    Notes: Summary The object of the experiments was to obtain changes typical for Wilson's disease and hepatogenic encephalopathy in glial tissue cultures. The experiments were carried out on newborn rat cerebellum tissue cultures. The standard medium was supplemented with: 1. Serum from patients with Wilson's disease, 2. serum from patients with hepatic coma, 3. copper acetate, 4. ammonium chloride. In all experimental groups typical morphological changes of glial cells were observed. These took the form of Alzheimer cells type I and II, Opalski cells, and intermediate cells. Histochemical abnormalities appeared in the form of an accumulation of neutral and acid mucopolysaccharides in the cytoplasm of Opalski and intermediate cells, with an accompanying decrease of SDH and GDH activity, and an increase in G-6PDH and acid phosphatase activity. The possible pathogenic mechanism of the above changes is discussed. The authors suggest both copper and ammonia cause damage in the intracellular enzymatic chains involved in carbohydrate metabolism. This damage leads to an accumulation of mucopolysaccharides in the glial cells.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 4 (1965), S. 659-668 
    ISSN: 1432-0533
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Morphologie der Opalski-Zellen und die histochemischen Eigenschaften der ihr Cytoplasma erfüllenden Stoffe werden dargelegt. Im morphologischen Bild der Opalski-Zellen wird besonders das Vorhandensein von Zellfortsatzresten hervorgehoben, die sowohl in den Routinezellfärbungen als auch in der Cajal-Goldsublimat-Imprägnation zu sehen sind, was nach der Meinung des Autors auf die Herkunft der Opalski-Zellen aus Astrocyten hinweist. Die zweite morphologische Haupteigenschaft der Opalski-Zellen machen die das Cytoplasma erfüllenden PAS-positive Granula aus. Auf Grund der durchgeführten histochemischen Tests werden diese granulären Substanzen als saure Mucopolysaccharide in Bindung an kupferhaltige Zellproteine betrachtet. Die Opalski-Zellen als degenerative Astrogliaformen erscheinen als Ergebnis von Störungen im intracellulären Stoffwechsel der Astrocyten; dieser zufolge werden abnorme Metaboliten der beschriebenen Art im Cytoplasma angehäuft. Die Opalski-Zellen leiten sich aus Zellen vom Alzheimertyp I ab; es erscheint jedoch möglich, daß sie sich auch direkt aus typischen Astrocyten entwickeln. Vereinzelte Opalski-Zellen kommen auch außerhalb der hepatolenticulären Degeneration, z.B. in Fällen von hepatogener Encephalopathie vor.
    Notes: Summary The morphology of Opalski cells and histochemical properties of substances filling their cytoplasm are discussed. In the morphological picture of Opalski cells special attention has been paid to the presence of residual cell processes which are visible both in the routin cellular stainings and in gold-sublimate Cajal impregnation. Their presence and positive metalic impregnation in the author's opinion, are conclusive for astrocytic origin of Opalski cells. The second fundamental morphological feature of Opalski cells consisted in the presence of PAS-positive granulations filling their cytoplasm. On the basis of the histochemical tests performed, the author considered these granular substances as acid mucopolysaccharides bound with cellular proteins containing copper. Opalski cells, being a degenerative forms of astroglia appear as the result of disturbances in the intracellular metabolism of astrocytes. Subsequently to this metabolic disorders in their cytoplasm, abnormal metabolites of the above described character are accumulated. Opalski cells originate from Alzheimer cells type I, however, it seems, that their direct development from typical astrocytes avoiding the stage of Alzheimer cells, is also possible. A few examples of Opalski cells could be seen also apart from hepato-lenticular degeneration, for instance in cases hepatogenic encephalopathy.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 19 (1971), S. 301-306 
    ISSN: 1432-0533
    Keywords: Wilson's Disease ; Opalski Cells ; Tissue Culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The object of the present study was to analyse the ultrastructure of Opalski cells, obtained in tissue culture according to the method described by Mossakowskiet al. (1970). The electron microscopic picture of the Opalski cells was characterized by scanty endoplasmic reticulum and Golgi apparatus and a greatly reduced number of mitochondria, as compared with glial cells cultured in vitro. Their cytoplasm contained two types of spherical bodies, one of which corresponded to lysosome-like bodies; the second one, in the authors' opinion, represented an accumulation of mucopolysaccharide substances. The ultrastructural picture of Opalski cells corresponded well with their previously described histochemical properties.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0533
    Keywords: Carbon monoxide intoxication ; Brain ; Glycogen ; UDPG-G glucosyltransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The glycogen content and its topography and the activity of UDPglucose-glycogen glucosyltransferase in the brain of rats after CO intoxication were investigated. A transient increase in glycogen content and in the enzyme activity was noticed. The highest level of glycogen was observed after 4h and the most significant increase of the enzyme activity after 2h, returning to normal values after 120 h. In the histochemical studies glycogen was deposited in the perivascular astrocytes, in their cytoplasm and astrocytic processes. These changes were localized in the cerebral and cerebellar cortex and in the grey formations of brain stem and were expressed mostly after 4, 6 and 12 h following CO intoxication.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0533
    Keywords: Glycogen ; UDP G-G Glucosyltransferase ; Glycogen Phosphorylase ; Cerebral Ischemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The activity of UDPglucose-glycogen glucosyltransferase and of glycogen phosphorylase in the brain of rats subjected to experimental ischemia was in vestigated. A transient increase in UDPglucose-glycogen glucosyltransferase activity was noted in the period between the 12th and 48th h after the operation. The enzyme level returned to its initial value after 72 h of ischemia. Glycogen phosphorylase activity was studied in preparations with and without 5′ AMP added. The enzyme activity increased from the 12th to the 72nd h of the experiment and returned to normal after 120 h in the brain of rats with ligated arteries, and also in the control group subjected to sham operation. In normal rats and those anaesthetised only, no changes were found in brain glycogen phosphorylase activity. The enhanced UDPglucose-glycogen glucosyltransferase activity may be responsible for the glycogen deposition in rat brain in experimental ischemia.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 26 (1973), S. 107-114 
    ISSN: 1432-0533
    Keywords: Experimental Glial Changes ; Opalski Cells ; Tissue Culture ; SDH Inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The object of the experiment was to obtainin vitro the glial changes typical of hepatogenic encephalopathy, after inhibition of one of the stages of the Krebs cycle. A chemical inhibitor of succinic dehydrogenase, sodium malonate, was added to the culture medium in various concentrations. The experiment was carried out in four groups. The damage to the metabolism of the Krebs cycle resulted in the appearance of typical Opalski cells and intermediate cell forms. These pathological cells exhibited the same morphological and histochemical properties as those observed in experimental hepatogenic encephalopathy in vivo and in vitro. The striking feature of the Opalski cells was a significant decrease of SDH and GDH activity. The authors discuss the possible pathogenesis of the glial changes which are probably due to the disturbance of ammonia detoxication.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-0878
    Keywords: Key words Cerebrovascular development and injury ; Hemangioma ; Angiogenesis ; Immunocytochemistry ; Adhesion molecules ; Conventional transmission and high-voltage electron microscopy ; Mouse (C57BL ; SJL/J) ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Blood vessels from the vasculature of mouse brains during postnatal development and from human brain tumors (hemangiomas) removed at biopsy were examined immunocytochemically by transmission electron microscopy (TEM) or high-voltage transmission electron microscopy (HVEM) to determine the expression of intercellular adhesion molecule-1 (ICAM-1). In the mouse brains, ICAM-1 was shown to be initially expressed on the luminal and abluminal endothelial cell (EC) surfaces on day 3 after birth. ICAM-1 intensity increased on the luminal EC surfaces and labeled vesiculotubular profiles (VTS, defined in the present report) between days 5 and 7. After 2 weeks and at 6 months after birth, ICAM-1 labeling was weak or absent on the luminal EC surfaces. The hemangiomas presented a strong ICAM-1 reaction product on the luminal EC surfaces of small and large blood vessels associated with the VTS, with a weaker labeling of the abluminal or adventitial aspects of larger blood vessels. TEM of vesiculovacuolar structures (VVOs) within ECs from arteries and veins also demonstrated reaction product for ICAM-1 labeling. Three-dimensional stereo-pair images in the HVEM enhanced the visualization of gold particles that were attached to the inner-delimiting membrane surfaces of EC VTS, and VVOs, respectively. These observations raise the possibility that the neonatal leukocytes and tumor cells may utilize these endothelial structures as a route across the developing and injured blood-brain barrier (BBB).
    Type of Medium: Electronic Resource
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