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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 296 (1977), S. 199-203 
    ISSN: 1432-1912
    Keywords: UDP-glucuronyltransferase ; l-Naphthol ; Perfused rat liver ; CCl4 injury ; UDP-glucuronic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the disparity between glucuronidation rates in vivo and UDP-glucuronyltransferase in vitro after CCl4 injury, the time course of the effects of CCl4 (0.25 ml/kg) on kinetic properties of UDP-glucuronyltransferase (l-naphthol as substrate) was examined in rat liver homogenates and microsomes. These experiments were compared with 1-naphthol glucuronidation by the perfused liver which was studied at various time points after CCl4 administration. Phenobarbital-treated rats were used to enhance the hepatotoxicity of CCl4. 1. Within 24 h UDP-glucuronyltransferase activity increased 8-fold in liver homogenates and 3-fold in microsomes. During this time the allosteric activator, UDP-N-acetylglucosamine, lost its effect whereas the inhibitor UDP showed greater inhibitory properties, thus counteracting the activation. 2. 1-Naphthol glucuronidation in perfused livers was significantly decreased by 24 h. Sulfate ester formation was little affected. 3. The content of UDP-glucuronic acid was not significantly altered although liver histology revealed about 45% necrotic and prenecrotic cells and an uniform fatty degeneration of hepatocytes after 24 h. The results suggest that during CCl4 injury, UDP-glucuronyltransferase is activated. At the same time the kinetic properties of the enzyme are altered in a way leading to inefficient glucuronide synthesis, when assays are carried out under conditions presumed to exist in vivo. Nevertheless the capacity to form glucuronides is retained in the acutely injured liver.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0428
    Keywords: Insulin ; glycogen ; amino acid ; alloxan diabetes ; cultured hepatocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of insulin on net glycogen synthesis and amino acid incorporation into protein were studied in cultured hepatocytes from adult normal and alloxan diabetic rats. Insulin stimulated glycogen synthesis in monolayer cells throughout a four day culture period and enhanced leucine incorporation into protein more effectively in normal cells with high glycogen levels than in cultured diabetic cells. These differences correlate well with the observed cellular ultrastructures which were maintained much better in the presence of insulin. Restoration of the morphological changes of alloxan diabetic hepatocytes to normal liver cell structures can be observed at any time during the culture period by giving insulin continuously.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: Neurovisceral lipidosis ; Niemann-Pick disease type C ; Oligomembranous cytoplasmic bodies ; Lipids ; Sphingomyelinase ; Prenatal diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One postnatal and one prenatal case (same family) of a neurovisceral lipidosis compatible with a diagnosis of Niemann-Pick disease type C were studied. The postnatal case, aged 4 and 6/12 at death, was characterized morphologically (foamy cells in the bone marrow; storage histiocytes in rectal submucosa and extraneural viscera and ballooned neurons, the two types of cells containing pleomorphic and oligomenbranous inclusion bodies, respectively; central demyelination) as well as biochemically (elevated spleen and liver content of sphingomyelin, cholesterol, glucosyl ceramide and lysobisphosphatidic acid). Sphingomyelinase activity (SM) was not significantly lowered and showed no greatly abnormal electrofocused pattern of activity; its extractability from brain, liver and spleen was distinctly hindered, a finding interpreted as expression of a reduced bioavailability of the enzyme. — The prenatal case was diagnosed by low SM in amniotic fluid. Diminished SM was confirmed in cultured amniotic cells and in tissues of the aborted fetus which, additionally, showed an elevated sphingomyelin and cholesterol content in the liver. A prenatal diagnosis of Niemann-Pick disease type C was made for the first time. The phenotypical variation of the disease may reflect genetic heterogeneity and, there-fore, a prenatally lowered SM need not be a constant finding. — The apparent normalization of SM in the postnatal case was accompanied by a decrease of visceromegaly raising the question of a causal relationship between the two phenomena.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 210 (1975), S. 41-66 
    ISSN: 1432-1459
    Keywords: Muscle metabolism, disorders of ; Glycogen storage diseases ; Myotonia congenita ; Paramyotonia congenita ; Relaxing factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über eine bisher unbekannte hereditäre Myopathie berichtet, die wie Muskelglykogenosen vom Typ des McArdle-Syndroms mit aktionsabhängigen Paresen und schmerzhaften Muskelverkrampfungen einhergeht. Im Unterschied zu diesen besteht eine weitgehende Beschränkung der Symptomatik auf die Arme. Licht- und elektronenmikroskopische sowie histochemische Untersuchungen zeigen lediglich uncharakteristische und diskrete myopathische Zeichen. Die Serumaktivitäten der CPK und Aldolase sind intermittierend erhöht. Der prompte Lactatanstieg im Venenblut beim Ischämie-Arbeitstest spricht gegen eine gestörte Glykogenolyse und Glykolyse. Die Aktivitäten der Phosphorylase und weiterer Schlüsselenzyme sind in den betroffenen Muskeln normal. Eine Erhöhung des ionisierten Calciums i. S. steht möglicherweise mit der gestörten myofibrillären Relaxierung in Verbindung. Das EMG zeigt in generalisierter Ausdehnung die Zeichen eines leichten myotonischen Syndroms. In den klinisch betroffenen Muskeln resultiert bei maximaler Anspannung eine zunehmende, starke Lichtung des Aktivitätsmusters. Die hierbei ausgelösten Krämpfe sind nicht Ausdruck einer paradoxen myotonen Reaktion, sondern stellen elektromyographisch stumme Kontrakturen dar. Das Manifestationsalter dieser dominant vererbten Myopathie schwankt in der von uns beobachteten Sippe bei 4 Krankheitsfällen in 3 Generationen zwischen 4 und 33 Jahren. Der Verlauf ist durch fehlende Progredienz bezüglich Schwere und Ausbreitung der Störung gekennzeichnet. Das Myopathia myotonica benannte Krankheitsbild wird differentialdiagnostisch von den paramyotonen Syndromen und von klinisch ähnlichen metabolischen Myopathien abgegrenzt.
    Notes: Summary A new type of hereditary muscle disease, characterized by weakness and painful spasms during effort, without electrical activity in the shortened muscles, is described. These phenomena are limited principally to the upper limbs. In addition we found electromyographical signs of a generalized myotonic syndrome. The histological and histochemical investigations reveal only minimal non-specific signs of myopathy. The activities of CPK and aldolase in the blood serum are increased at times. A normal elevation of venous lactate was observed during ischemic work. The biochemical studies of muscular tissue exhibit normal activities of the analyzed enzymes, especially as regards phosphorylase. An increased concentration of calcium ions in blood serum may be related to the contraction during strenuous work; it is known that calcium ions are an important factor in the contraction-relaxation cycle of striated muscle. The age of manifestation varied from 4 to 33 years in 4 cases of the relatives observed. The disease shows no signs of aggravation as to the severity and extent of the disorders. The nature of the underlying metabolic defect is still unknown.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Basic research in cardiology 74 (1979), S. 10-20 
    ISSN: 1435-1803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um eine Arteria carotis von Kaninchen wurde eine 8 mm lange Manschette aus Teflon so locker herumgelegt, daß die Pulsationen des Gefäßes nicht behindert waren. In die Manschette waren 1 mm breite, 8 mm lange Goldelektroden eingebaut, die eine transmurale Reizung des Gefäßes ermöglichten. Durch entsprechende Reizanordnung wurden die Arterien der wachen, frei beweglichen Tiere täglich mit stromkonstanten Gleichstromimpulsen eine halbe Stunde oder 2 x eine halbe Stunde lang während einer Versuchsdauer bis zu 6 Wochen gereizt. Die kontralaterale Arterie diente als Kontrollgefäß. Sie wurde ebenfalls mit einer Manschette ungeben, aber nicht elektrisch gereizt. Nach einer halben Stunde Reizzeit (10 Hz, 1,5 mA, 1 ms/Imp) erschlafften die Gefäßwände nach initialer Konstriktion. Wiederholung der Reize bewirkte Proliferation der subendothelialen Gefäßwandzellen in der gereizten Region, vor allem innerhalb des Anodenbereichs. Die proliferierten Zellen wurden elektronenmikroskopisch als glatte Muskelzellen identifiziert. Sie enthielten relativ mehr Lysosomen und endoplasmatisches Retikulum als die ursprünglichen Mediazellen und produzierten kollagene Fasern und elastische Fasern als extrazelluläres Matrix-Material. Unter den sich in das Gefäßlumen hineinentwickelnden dicken Kissen von glatten Muskelzellen entstanden medianahe Nekrosen. Tiere, die zusätzlich 2% Cholesterin in der Nahrung erhielten, entwickelten anodennah typische atheromatöse Plaques.
    Notes: Summary 8 mm long sections of common carotid arteries of conscious, freely moving rabbits were electrically stimulated with DC-impulses by chronically implanted gold-electrodes daily for 1/2h or two time 1/2h per day for 4–6 weeks. The electrodes were arranged in such a way that the wall was stimulated transmurally. In the initial phase the tension of the vessel wall increased. After 1/2 h of stimulation the artery wall relaxed at the stimulated section. Repetition of stimuli led to smooth muscle cell proliferation within the stimulated region. The smooth muscle cells formed a cushion protruding into the lumen of the artery mainly at the anodic site of the stimulation-arrangement. The proliferating cells were smaller than those of the underlying tunica media. They were identified as smooth muscle cells by electron-microscopy, contained relatively more lysosomes and endoplasmic reticulum than the original media-cells and produced collagen-fibrils and elastic fibrils as an extracellular matrix material. Below very thick cushions of smooth muscle cells necrosis developed. Animals which were additionally fed with 2% cholesterol in normal food developed typical atheromatous plaques at the site of the anodic stimuli.
    Type of Medium: Electronic Resource
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