Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 52 (1974), S. 255-265 
    ISSN: 1432-1440
    Keywords: Tetanus toxin ; Antitoxin ; 125Iodine ; Spinal cord ; Nerves ; Tetanustoxin ; Antitoxin ; 125Jod ; Rückenmark ; Nerven
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Unsere Kenntnis der Pathogenese des Wundstarrkrampfes hat sich durch Anwendung neuer biochemischer und neurophysiologischer Techniken innerhalb der letzten Jahre erheblich erweitert. Radioaktiv markiertes Tetanustoxin wurde innerhalb verschiedener Nerven bis zu den Vorderhörnern des Rückenmarks verfolgt; dort wurde das Toxin z.T. noch auf cellulärer Ebene nachgewiesen. Die Verteilung des Toxins ist zeitabhängig und wird durch Antitoxin beeinflußt. Je weiter der Zeitpunkt der Vergiftung zurückliegt, desto geringer ist der Effekt des Antitoxins auf die Symptomatologie und die spinale Anreicherung des Toxins. Die neurale Wanderung des Toxins wird durch Erregung des toxinhaltigen Nerven gefördert. Neben den motorischen Anteilen sind auch rein sensibel-sensorische und vegetative Nerven zur Weiterleitung des Toxins imstande. Der generalisierte Tetanus kann als eine Sonderform des lokalen Tetanus betrachtet werden. Während bisher das klassische α-motorische System des Rückenmarks im Vordergrund der Untersuchungen stand, weisen neuere Arbeiten auf eine gleichzeitige, vielleicht sogar vorwiegende Enthemmung des γ-motorischen Systems hin. Außerdem werden vegetative Spinalreflexe enthemmt, was auch bei der Therapie bedacht werden sollte. Die Hemmwirkung des Tetanustoxins auf periphere Synapsen weist auf große Ähnlichkeiten mit Botulinumtoxin hin, obwohl die Symptome am vergifteten Tier so verschieden sind. Künftige Untersuchungen werden sich voraussichtlich mit der Wirkungsweise des Toxins auf molekularer und cellulärer Ebene befassen.
    Notes: Summary Due to the use of advanced biochemical and neurophysiological techniques, our knowledge of the pathogenesis of tetanus has considerably improved during the past years. Radio-labelled tetanus toxin has been traced within different nerves up to the anterior horn of the spinal cord where its localization down to the cellular level has been achieved. The distribution of labelled toxin depends on time and is influenced by antitoxin. The longer the duration of poisoning, the smaller the effect of antitoxin on the spinal enrichment of toxin and on the onset of toxic symptoms. The neural ascent of toxin into a spinal cord segment is enhanced by stimulation of the segmental nerves. Not only the motor nerves, but also sensory and vegetative nerves are able to serve as guide-rails for the toxin. The generalized tetanus has been understood as a special kind of local tetanus. For a long time, disinhibition of the alpha motor system was considered to be the characteristic action of tetanus toxin, but recent evidence is in favour of an additional disinhibition of the gamma motor system (perhaps even preceding the alpha disinhibition) and also of the sympathetic spinal reflexes. This finding should have therapeutic implications. The detection of inhibitory effects of tetanus toxin on peripheral cholinergic synapses points again to the close similarity between tetanus toxin and botulinum A toxin. The trends of future research will presumably lead to the elementary processes at the molecular and cellular level which are the basis of the clinical picture of tetanus.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 688 (1982), S. 486-494 
    ISSN: 0005-2736
    Keywords: (Erythrocyte) ; Amphotericin B ; Palytoxin ; Permeability
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 319 (1982), S. 101-107 
    ISSN: 1432-1912
    Keywords: Palytoxin ; Ouabain ; Erythrocytes ; Permeability ; ATPase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Palytoxin in concentrations as low as 1 pM raises the potassium permeability of rat, human and sheep erythrocytes, and the sodium permeability of human erythrocytes. The release of potassium or sodium from human cells also occurs when extracellular sodium is replaced by choline. 2. Ouabain inhibits the release due to palytoxin of potassium ions from human, sheep and rat erythrocytes, and also the release of sodium ions from human cells. The glycoside effect is specific since a) it is already prominent with 5×10−8 M ouabain b) rat erythrocytes are less sensitive than human cells to ouabain c) potassium release due to amphotericin B or the Ca2+ ionophore A23187 is not influenced by ouabain and d) dog erythrocytes are resistant to palytoxin as well as to ouabain. 3. Palytoxin has no direct influence on the Na+, K+-ATPase. It inhibits the binding of [3H]ouabain to erythrocyte membranes within the same concentration range as unlabelled ouabain. It partially displaces bound [3H]ouabain, and partially inhibits the inactivation of erythrocyte ATPase by the glycoside. Depletion of ATP or of external Ca2+ renders the cells less sensitive to palytoxin. Nevertheless inhibition by ouabain can be still demonstrated with human cells whose ATP stores had been largely exhausted, and also in the absence of external Ca2+. 4. Palytoxin decreases the surface tension at the air-water interface. We assume that the formation of nonspecific pores by palytoxin is linked with its surface activity. Further experiments should demonstrate whether ouabain prevents the binding of palytoxin to erythrocytes (“receptor hypothesis”), or whether an ouabain-sensitive hydrolysis of trace amounts of ATP (“metabolic hypothesis”) promotes the palytoxin effect.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 264 (1969), S. 476-493 
    ISSN: 1432-1912
    Keywords: Kinins ; Permeability ; Heat ; Inflammation ; Kinine ; Permeabilität ; Hitze ; Entzündung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The suboutis of rat paws heated (46,5° C) in situ has been perfused. Kinin activity could be demonstrated regularly in the fluid which was collected in ice. When the solutions were tested immediately after having passed the tissue, only some of the experiments yielded positive results. Native and125Jlabelled kininogen as well as kininogenase and kininase activities passed into the perfusates. The sensitivity to dextran and the kinin release on heating were, in contrast to recent reports, not correlated. 2. The release of the components of the kinin system approximately paralleled that of labelled human albumin. Their concentration rose until about 1 hour after the start of the heating. There was no priority of the components of the kinin system when compared with human albumin which can be regarded as permeability indicator. 3. Intravenously injected carboxypeptidase B, because of its lower molecular weight, entered the interstitial fluid more easily than did the plasma carboxypeptidase N. Its blood level decreased rapidly; but sufficient tissue concentrations could be maintained by intravenous infusions. Neither the volume nor the time dependence of the thermic edema changed during carboxypeptidase B-infusions. The same was true for infusions of trasylol, whereas phenylbutazone inhibited the edema significantly. Edema formed by short heating (30 sec, 55° C) was equally resistant to carboxypeptidase B. 4. In the skin and muscles of the heated rat paw, carbon particles mainly stained the capillary walls. This finding argues against a considerable involvement of “classical” mediators which should induce venular lesions. 5. Infusion of large amounts of bradykinin into the arterial supply did not imitate the thermic edema; neither has bradykinin been found in the perfusate of the subcutis. 6. In the light of these findings, a significant role of the kinin system in the thermic edema of the rat paw is to be doubted.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 276 (1973), S. 361-373 
    ISSN: 1432-1912
    Keywords: Tetanus Toxin ; Iodine Labelling ; Spinal Cord ; Autoradiography ; Antitoxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The in vivo interaction of 125I-labelled toxin with substructures of rat spinal cord has been studied. The rats were poisoned by i.v. injection about 40–50 h before sacrifice. 1. The labelled material accumulates in the grey substance, which is, on microdissection, about 6 times more active than the white. Autoradiography reveals that the toxin is particularly enriched in the ventrolateral part of the grey substance. 2. On ultracentrifugation of the homogenates, the label is preferentially fixed to the dense fractions known to contain the synaptosomes. However, a considerable part of the toxin is fixed to the lighter fractions too. 3. Upon gel filtration, the labelled material in SDS-homogenates from spinal cords poisoned in vivo is indistinguishable from toxin added to the homogenates already prepared. The same is true for the bulk of radioactivity when subjected to disc gel electrophoresis. 4. The labelled material is degraded by enzymes from spinal cord at pH 3.5, but not at pH 7.5. 5. The labelled material is relatively firmly bound to structures of spinal cord. The bonding is fairly resistant against washing, even in the presence of an excess of cold toxin, but it can be partially released by treatment with antitoxin. According to these findings, the labelled material is firmly but not irreversibly bound in vivo to discrete structures, corresponding preferentially to the synaptosomal fractions in the homogenates and the ventrolateral grey in the slices. No evidence has been found for its degradation in vivo. So far, the bulk of labelled material in the spinal cord is indistinguishable from tetanus toxin.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 276 (1973), S. 341-359 
    ISSN: 1432-1912
    Keywords: Tetanus Toxin ; Iodine Labelling ; Central Nervous System ; Receptors ; Antitoxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Lyophilized homogenate of rat brain binds 125I-labelled tetanus toxin better than does homogenate from spinal cord. This is in contrast to the in vivo behaviour of the toxin where it is bound only to spinal cord. Liver homogenate does not fix the toxin. 2. Autoradiography of preincubated slices from spinal cord shows that the radioactivity is evenly and nearly exclusively bound to gray matter. 3. Maximally 40% of the labelled material interacts with brain homogenate. The toxicity of the remaining supernatant is much more reduced than is its radio-activity. 125I-toxoid, prepared from labelled toxin by treatment with formol, is bound only very weakly. Thus we assume that our toxin preparation is already partially toxoided, and that binding to CNS matter bears some relevance to toxicity. 4. The fixation of the labelled toxin is reversible. The degree of reversibility depends on the conditions used. Binding can be nearly completely reversed or prevented by treatment with antitoxin, but not more than 50% of the binding is reversed by treatment with unlabelled toxin. Repeated washings also remove the bulk of the initially bound toxin. Thus binding sites with different affinities are to be assumed. 5. A complex between ganglioside and cerebroside binds the labelled toxin more firmly than does brain homogenate. No competition between unlabelled and labelled toxin has been observed for this solid phase. Antitoxin nearly completely prevents and largely reverses the fixation of labelled toxin. 6. On the basis of the selective, competitive reactivity of labelled and unlabelled tetanus toxin with brain matter, a radio receptor assay has been developed. It can be used for the measurement of tetanus toxin down to 5 ng. 7. Gradient centrifugation of sucrose homogenates preincubated with labelled toxin reveals one peak of radioactivity in the fractions where the synaptosomes are to be expected; the larger part of the toxin remains, however, unevenly distributed near the starting volume. 8. Desoxycholate solubilizes the complex between labelled toxin and brain matter with parallel dissolution of brain proteins. 9. Neither brain nor spinal cord homogenates degrade labelled toxin into TCA-soluble fragments at pH 7.5. Partial degradation occurs, however, at pH 3.5.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...