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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Pflügers Archiv 378 (1979), S. 205-212 
    ISSN: 1432-2013
    Schlagwort(e): Excitatory synaptic current ; Time course ; Membrane potential ; Ca2+ ; Sympathetic ganglion cell
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The membrane current underlying the fast excitatory postsynaptic potential (EPSC) of bullfrog sympathetic ganglion cells was studied. The relationship between the EPSC amplitude and membrane potential was linear at negative levels of membrane potential, but deviated from the linearity toward a smaller amplitude at positive levels. The falling phase of EPSC almost followed a single exponential decay. The half-decay time (HDT) of EPSC's increased exponentially with an increase in the negativity of membrane potential. The rise time (RT) was also prolonged slightly with membrane hyperpolarization. Lowering of temperature decreased the EPSC amplitude, lengthened markedly the HDT and increased the slope relating the logarithm of the HDT to membrane potential. Neostigmine (1×10−5 M) prolonged both the RT and HDT. A decrease in Ca2+ concentration caused a marked reduction in the EPSC amplitude, and a slight shortening in the RT and HDT. An increase in Ca2+ concentration significantly prolonged the RT and HDT without altering the slope of the relationship between the HDT and membrane potential, while the amplitude of EPSC was increased slightly. The HDT was independent of EPSC amplitude. It is suggested that the mechanism responsible for closing the ion channels of the nicotinic receptor at the subsynaptic membrane is regulated by membrane potential. The possible mechanisms of the action of Ca2+ on the decay phase of EPSC were discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 0942-0940
    Schlagwort(e): Cerebral aneurysm ; endovascular surgery ; EVAL mixture ; liquid embolus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Embolization of three surgically difficult cerebral aneurysms was performed using our newly developed non-adhesive embolic material, EVAL mixture (ethylene vinyl alcohol copolymer). Conventional embolic materials such as detachable balloons or microcoils were not used because of a large or irregular aneurysmal neck. After temporary occlusion of the parent artery with a superselective balloon catheter, the EVAL mixture was slowly injected through a microcatheter placed in the aneurysm or parent artery. The locations of the aneurysms were anterior communicating artery, basilar artery-posterior cerebral artery and basilar artery-anterior inferior cerebellar artery (BA-AICA). One aneurysmal occlusion and 2 parent artery occlusions were performed. Patients had no persistent deficits. The patient with the BA-AICA aneurysm associated with an arteriovenous malformation died of rupture of the residual AVM due to haemodynamic change 2 weeks after embolization. In selected and limited cases, embolization of surgically difficult cerebral aneurysms using EVAL mixture was more effective and safer than embolization using conventional embolic materials such as balloons and microcoils.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1437-7799
    Schlagwort(e): Key words Thin basement membrane disease (TBMD) ; Glomerular basement membrane (GBM) ; tubular basement membrane ; Age
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background. Thin basement membrane disease (TBMD) is a benign hereditary glomerulopathy with a diffuse attenuation of glomerular basement membrane (GBM). Whether the development of renal basement membranes other than GBM is normal in TBMD has not yet been resolved. Methods. We performed a morphometric study to measure the thickness of GBM and proximal tubular basement membrane (P-TBM) in 44 adult patients with TBMD and in 10 adult diseased controls confirmed to have minor glomerular abnormalities. Results. There was a significant difference between the patients with TBMD and the diseased controls in the thickness of the GBM; however, there was no significant difference between the two groups in the thickness of the P-TBM. In the patients with TBMD, the thickness of the GBM was unchanged with age, but the thickness of the P-TBM increased with age, as did that in the diseased controls. Conclusion. Our morphometric study clarified that the development of P-TBM was normal in the patients with TBMD.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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