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  • 11
    Electronic Resource
    Electronic Resource
    Split lung ventilation in a patient with differential pulmonary hemodynamics (1998)
    Springer
    Intensive care medicine 24 (1998), S. 1232-1233 
    Details
    ISSN: 1432-1238
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340050752
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  • 12
    Electronic Resource
    Electronic Resource
    Different inhibition patterns of tedisamil for fast and slowly inactivating transient outward current in rat ventricular myocytes (1998)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 357 (1998), S. 291-298 
    Details
    ISSN: 1432-1912
    Keywords: Key words Rat ventricular myocyte ; Voltage-clamp ; Transient outward current ; Action potential ; Tedisamil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Tedisamil has been described as a selective inhibitor of a fast inactivating transient outward current (ito,f) in rat ventricular myocytes. Because recent reports demonstrated the existence of a second slowly inactivating transient component (ito,s) we investigated ito,s and differentiated the effects of tedisamil on both transient outward current components and their influence on action potential duration. Standard electrophysiological techniques were used for whole cell recordings at 24–26° C from enzymatically isolated myocytes. Inhibition of ito,f by tedisamil was the result of an acceleration of inactivation at positive test potentials with a concentration for halfmaximal inhibition (EC50) of 4–7 μmol/l, which is confirmatory to reports from other investigators. Our new results show that ito,s is more sensitive to tedisamil with an EC50 of 0.5 μmol/l. Furthermore the pattern of ito,s inhibition is different compared with ito,f, because inactivation of ito,s is not accelerated by tedisamil. Instead the amplitude of the steady state inactivation curve of ito,s is attenuated which indicates a reduction of maximally available current. Ito,s was evaluated by three different methods as time-dependently inactivating current (7.5 s test pulse duration), voltage-dependently inactivated current and tedisamil-sensitive current. All approaches yield similar inactivation curves. The potential for halfmaximal inactivation of ito,s lies about 35 mV more negative than that for ito,f and the slope factor (K = –23 mV) is different to that of ito,f (K = –3 mV). Effectiveness of tedisamil-induced modulation of ito,f and ito,s on action potential repolarization was tested. Action potentials stimulated at 0.5 Hz were not prolonged by 1 μmol/l tedisamil (dominant ito,s block) at a repolarization level of 0 mV but prolonged to about 120% of control at –70 mV. This indicates that ito,f was sufficient to guarantee a regular early repolarization whereas decrease of ito,s delayed the final repolarization. In conclusion, the observation that tedisamil inhibits ito,f and ito,s differently supports the hypothesis that the two ito-components are related to two different channel populations expressed in rat ventricular myocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00005170
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  • 13
    Electronic Resource
    Electronic Resource
    Effects of 17β-estradiol on action potentials and ionic currents in male rat ventricular myocytes (1997)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 356 (1997), S. 788-796 
    Details
    ISSN: 1432-1912
    Keywords: Key words 17β-Estradiol ; Action potential ; Transient ; outward currents ; Calcium current ; Rat ventricular ; myocyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study describes electrophysiological effects of estrogens in isolated male rat ventricular myocytes. According to the literature these cells do not express the nuclear estrogen receptor. Action potentials or membrane currents were recorded in the whole-cell configuration with standard techniques. Action potential durations (APD) measured at a level of 0 mV (APD 0) and –70 mV (APD –70) were prolonged by 17β-estradiol (0.5 Hz stimulation frequency, 24–26° C). Threshold concentration was 1 μmol/l. At the highest concentration used (30 μmol/l) no saturation of the response was reached and APD 0 was 162% and APD –70 was 230% of the respective control. The resting potential remained unaffected in most cells. The prolongation induced by 17β-estradiol developed rapidly and reached a steady state 10 min after start of hormone superfusion. Effects of estrogen were completely reversible during 10–15 min wash-out with hormone-free solution. The extent of prolongation (10 μmol/l 17β-estradiol) was frequency dependent. Expressed as percentage of the respective control APD 0 (or APD –70) was 115% (188%) at 0.05 Hz, 118% (163%) at 0.5 Hz and 99% (129%) at 5 Hz stimulation frequency. The response was stereoselective, because 30 μmol/l 17α-estradiol did not prolong action potentials (APD 0: 101%, APD –70: 104% of the respective control, 0.5 Hz stimulation frequency). The endogenous estrogens estrone and estriol were less effective than 17β-estradiol. With 30 μmol/l estrone (0.5 Hz stimulation frequency) APD 0 was 103% and ADP-70 148% of control and with 30 μmol/l estriol APD 0 was 135% and APD –70 137% of control. The prolongation of action potentials can be explained by inhibition of transient outward current which, in rat ventricle, is composed of fast (i to,f) and slowly (i to,s) inactivating components. At 30 μmol/l 17β-estradiol i to,f was reduced to 50% and i to,s to 43% of their maximal amplitudes. The voltage sensor of i to,f or i to,s was hardly affected. Additionally, 17β-estradiol decreased the calcium current (i Ca,L) to 76% (10 μmol/l) and 38% at 30 μmol/l. The inwardly rectifying potassium current (i K1) was reduced partly with 30 μmol/l 17β-estradiol and its amplitude was 72% of control at –90 mV (inward current flow) and 65% at –40 mV (outward current flow). These results show that 17β-estradiol is active in cardiac cells which do not express the nuclear estrogen receptor. The hormone exerts class III activity and reduces calcium inward current. These effects, however, occur in vitro with concentrations above the physiological level and therefore may be without significance in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00005119
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  • 14
    Electronic Resource
    Electronic Resource
    Intensive therapy with peripheral stem cell transplantation in 16 patients with mantle cell lymphoma (1997)
    Springer
    Annals of oncology 8 (1997), S. 701-704 
    Details
    ISSN: 1569-8041
    Keywords: autologous transplant ; lymphoma ; mantle cell ; peripheral stem cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Despite improved detection of mantle cell lymphoma (MCL),results of its treatment with conventional therapies remain disappointing andthe survival rate poor. The role of high-dose chemotherapy has recently beeninvestigated but no potential benefit has been clearly established. We reporthere our experience with MCL patients treated with intensive chemotherapy andautologous stem cell transplantation (ASCT). Patients and methods: Of the 16 MCL patients who received high-dosechemotherapy and ASCT beginning in 1989, six were treated in first-line and10 in sensitive relapse. Twelve of 16 patients received regimens whichincluded total body irradiation. All patients received peripheral blood stemcells (PBSC) with the exception of one, who underwent bone marrowtransplantation. Results: Three patients died of toxic effects of treatment. Three monthsafter transplant, seven achieved complete responses (CR) and two partialresponses (PR), two were stable and two had progressed. With a medianfollow-up after transplant of 22 months, five of the six surviving patientswere without progression, and three were in CR. The median times forevent-free survival (EFS) and overall survival (OS) were, respectively, 249and 317 days. The expected three-year EFS and OS were 24%. The mediansurvival after diagnosis was only 29 months. None of the criteria appeared tobe significantly associated with a better outcome, but first-lineintensification and a short delay after initial diagnosis may be favorable. Conclusion: In this study we were not able to confirm the hypotheticalbenefit of high-dose chemotherapy and PBSC transplantation in mantle celllymphoma, even though this approach may be promising in a subgroup of patient.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008278605751
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  • 15
    Electronic Resource
    Electronic Resource
    Modulation of pacemaker activity in sheep cardiac Purkinje fibers by stimulation of β-adrenoceptor subtypes (1997)
    Springer
    Basic research in cardiology 92 (1997), S. 25-34 
    Details
    ISSN: 1435-1803
    Keywords: Sheep cardiac Purkinje fibers ; action potentials ; automaticity ; β1-β2- ; adrenoceptors-(−) ; isoproterenol ; (−)-noradrenaline ; procaterol ; bisoprolol ; ICI 118,551
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The electrophysiological effects mediated by β1- and β2- in spontaneously active sheep cardiac Purkinje fibers were investigated using the non-selective agonist (−)-isoproterenol (IPN) and the selective agonists (−)-noradrenaline (β1) and procaterol (β2) in the absence and presence of the selective antagonists bisoprolol (β1) and ICI 118,551 (β2). IPN (0.01 μmol/l) increased the spontaneous rate by 54% and the slope of diastolic depolarization by 68% of the respective control values. Further, IPN increased the action potential duration at −20 mV (APD −20 mV) from 96 to 154 ms, reduced the APD −70 mV by 17% and the duration of the diastole by 39% and slightly hyperpolarized the maximum diastolic potential. These effects were partially inhibited by ICI 118,551 (0.03 μmol/l), diminished by bisoprolol (0.1 μmol/l) and almost completely blocked by the combination of both antagonists. Concentration response curves of IPN were influenced by the selective antagonists as follows: ICI 118,551 (0.03 μmol/l) shifted the curves to the right by 0.2–0.4 log units and increased the slope factor. Bisoprolol (0.1 μmol/l) induced a greater shift to the right by 1.1–1.5 log units. Combination of bisoprolol with ICI 118,551 shifted the curves to the right by 1.5–1.7 log units. Noradrenaline (0.3 μmol/l) elicited similar actions as IPN. Bisoprolol (0.1 μmol/l) shifted the concentration response curves of noradrenaline to the right by 1.1–1.9 log units. Actions of procaterol (0.1 μmol/l) were weak, attained only 15–35% of the maximal effects of IPN and could be blocked by ICI 118,551 (0.03 μmol/l). These results show that the increase of pacemaker activity induced by catecholamines in sheep cardiac Purkinje fibers is predominantly mediated by stimulation of β1. However, contribution of β2 mediated effects could be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00803754
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  • 16
    Electronic Resource
    Electronic Resource
    Modulation of action potential duration by inhibition of the transient outward current in sheep cardiac Purkinje fibers (1995)
    Springer
    Basic research in cardiology 90 (1995), S. 185-191 
    Details
    ISSN: 1435-1803
    Keywords: Sheep Purkinje fiber ; voltage-clamp ; action potential duration ; transient outward current ; 4-aminopyridine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In sheep cardiac Purkinje fibers concentration-dependent inhibition of transient outward current (ito) by 4-aminopyridine (4-AP, 3-1000 μmol/l) was recorded with the two-microelectrode voltage-clamp technique, and correlated effects on action potential duration measured at — 70 mV (APD-70) were investigatigated. Half-maximal inhibition of ito-amplitude occurred at 15 μmol/l 4-AP. The drug exhibited no major effect on voltage-dependent control of inactivation but reduced the maximally available ito-current. At different activation frequencies (0.05 Hz, 0.25 Hz, 1 Hz) an equal amount of ito-current, measured as percentage of the respective control, was inhibited by 4-AP. The APD-70 was on the average increased by 4-AP (3–500 μmol/l) in a concentration-dependont manner up to 151 % of control. The drug-induced prolongation, measured as percentage of the respective control, was independent of stimulation frequency (0.05 Hz, 0.25 Hz, 1 Hz). Prolongation of APD-70 was on the average more pronounced for short action potentials (APD-70〈150 ms: 169 % of reference) than for longer ones (APD-70 150–300 ms: prolongation to 117 % of reference; 500 μmol/l 4-AP; 0.25 Hz stimulation rate). Few long control signals (APD-70 〉300 ms) were shortened by 4-AP. These results indicate that inhibition of ito-current by appropriate drugs will result in a reduction of inhomogeneity of action potential duration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00805661
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  • 17
    Electronic Resource
    Electronic Resource
    Hydrophobic layered double hydroxides (LDHs): selective adsorbents for liquid mixtures (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 681-688 
    Details
    ISSN: 1435-1536
    Keywords: Key words Adsorption ; anionic surfactants ; hydrophobic surfaces ; layered double hydroxide ; swelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The external and internal surface area of the calcium aluminum double hydroxide [Ca2Al(OH)6] NO3 ⋅ 2H2O were hydrophobized by the anionic surfactants sodium dodecylsulfate and sodium dodecyl-benzene sulfonate. The adsorption behavior towards liquid mixtures (benzene/n-heptane and n-propanol/ toluene) was studied by determining the surface excess adsorption isotherms, the heats of immersion in these liquids, and the basal spacing, i.e. the expansion of the interlayer space. Both hydrophobic layered double hydroxides (LDHs) adsorbed n-hep-tane, benzene, toluene, and n-pro-panol between the layers with considerable increase of the basal spacing. Interlamellar swelling of the hydrophobizised LDHs in n-heptane was fundamentally different to the behavior of hydrophobized 2 : 1 clay minerals (smectites, vermiculites). The surface excess isotherms for benzene/ heptane mixtures were U-shaped and indicate preferential adsorption of benzene. Dodecylbenzene sulfonate double hydroxide preferentially adsorbed propanol from n-propanol/ toluene mixtures but the dodecyl-sulfate derivative adsorbed both compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050135
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  • 18
    Electronic Resource
    Electronic Resource
    Paradoxe Lokalisation des Ohrenklingens bei der Ermüdung (1960)
    Springer
    European archives of oto-rhino-laryngology and head & neck 176 (1960), S. 606-608 
    Details
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung Bei akustischer Belastung bzw. Ermüdung eines Ohres tritt ein Klingen im anderen, unbelasteten Ohr auf (paradoxe Lokalisation). Versuche an einem einseitig Ertaubten beweisen, daß das Klingen nicht im unbelasteten Ohr entstehen kann. Versuche mit beidseitiger und wechselseitiger Vertäubung machen es wahrscheinlich, daß das Klingen auf einer zentralen Sensibilisierung beruht.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02135159
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  • 19
    Electronic Resource
    Electronic Resource
    Modulation of pacemaker activity in sheep cardiac Purkinje fibers by stimulation of β-adrenoceptor subtypes (1997)
    Springer
    Basic research in cardiology 92 (1997), S. 25-34 
    Details
    ISSN: 1435-1803
    Keywords: Key words Sheep cardiac Purkinje fibers – action potentials – automaticity –β1-adrenoceptors –β2-adrenoceptors – (–)-isoproterenol – (–)-noradrenaline – procaterol – bisoprolol – ICI 118,551
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The electrophysiological effects mediated by β1- and β2-adrenoceptors in spontaneously active sheep cardiac Purkinje fibers were investigated using the non-selective agonist (–)-isoproterenol (IPN) and the selective agonists (–)-noradrenaline (β1) and procaterol (β2) in the absence and presence of the selective antagonists bisoprolol (β1) and ICI 118,551 (β2). IPN (0.01 μmol/l) increased the spontaneous rate by 54% and the slope of diastolic depolarization by 68% of the respective control values. Further, IPN increased the action potential duration at –20 mV (APD –20 mV) from 96 to 154 ms, reduced the APD –70 mV by 17% and the duration of the diastole by 39% and slightly hyperpolarized the maximum diastolic potential. These effects were partially inhibited ICI 118,551 (0.03 μmol/l), diminished by bisoprolol (0.1 μmol/l) and almost completely blocked by the combination of both antagonists. Concentration response curves of IPN were influenced by the selective antagonists as follows: ICI 118,551 (0.03 μmol/l) shifted the curves to the right by 0.2–0.4 log units and increased the slope factor. Bisoprolol (0.1 μmol/l) induced a greater shift to the right by 1.1–1.5 log units. Combination of bisoprolol with ICI 118,551 shifted the curves to the right by 1.5–1.7 log units. Noradrenaline (0.3 μmol/l) elicited similar actions as IPN. Bisoprolol (0.1 μmol/l) shifted the concentration response curves of noradrenaline to the right by 1.1–1.9 log units. Actions of procaterol (0.1 μmol/l) were weak, attained only 15–35% of the maximal effects of IPN and could be blocked by ICI 118,551 (0.03 μmol/l). These results show that the increase of pacemaker activity induced by catecholamines in sheep cardiac Purkinje fibers is predominantly mediated by stimulation of β1-receptors. However, contribution of β2-receptor mediated effects could be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00803754
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  • 20
    Electronic Resource
    Electronic Resource
    Fistelsymptom bei Fistel am vertikalen Bogengang (1962)
    Springer
    European archives of oto-rhino-laryngology and head & neck 180 (1962), S. 692-695 
    Details
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02121536
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