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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 69 (1987), S. 213-219 
    ISSN: 1432-1106
    Keywords: Cortex slices ; Field potentials ; Current source density analysis ; Visual cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The method of one-dimensional current source density (CSD) analysis was applied to field potentials recorded from 350 μm thick slices of the primary visual cortex of rats and cats. Field potentials were elicited by stimulation of the white matter and recorded along trajectories perpendicular to the cortical layers at spatial intervals of 25 to 50 μm. The resulting CSD distributions resembled closely those recorded from the cat visual cortex “in vivo”. The responses with the shortest latency were distinct sinks in layers IV and VI probably reflecting monosynaptic EPSP's from specific thalamic afferents. From layer IV activity was relayed along three major routes: 1. to the supragranular layers via strong local connections to layer III and from there via both short and long range connections to layer II, 2. to targets within layer IV, and 3. to layer V. The source distributions suggest that the projections to layers III and II terminate on the proximal and distal segments, respectively, of apical dendrites of layer III pyramidal cells while the projection to layer V contacts the apical dendrites of layer VI pyramidal cells. These results indicate that all the excitatory pathways that are detectable with the CSD technique in the “in vivo” preparation remain intact in 350 μm thick cortical slices. However, in the slice paired pulse stimulation did not lead to a depression of the response to the second stimulus while this is the case “in vivo”. This might be due to reduced inhibition in the slice which has been reported by several authors.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Der Nervenarzt 68 (1997), S. 379-389 
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Neurobiologie ; Kortikosteroide ; Gelernte Hilflosigkeit ; Interpersonale Psychotherapie ; Pharmakotherapie ; Key words Neurobiology ; Corticosteroids ; Learned helplessness ; Interpersonal Psychotherapy ; Pharmacotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Our present understanding of the disorder ”depression” undergoes a changing process. Together with the appearance of empirical studies on epidemiology, genetics and therapy, the hypothesis of ”endogenous” depression has vanished. The search for ”markers” has been replaced by a growing interest for functional connections, thereby generating a variety of possible etiological factors instead of the ”depressogenic” synapse. Therapy has been revolutionized by the invention and the empirical proof of new, short-term psychotherapies. However, the lack of a theoretical basis warrants its development as a major endeavor for future research.
    Notes: Zusammenfassung Unsere Vorstellungen über die Krankheit „Depression” wandeln sich: mit der Aufgabe des theoretischen Modells der „endogenen” Depression änderten sich auch Forschungsansätze und Behandlungsmöglichkeiten. Die biologische Forschung richtet ihr Interesse nicht mehr auf die bisher vergebliche Suche nach Markern, sondern auf funktionelle Zusammenhänge. Dabei wurde die „depressogene” Synapse durch andere Modelle abgelöst. – Eine zentrale Rolle spielt das Kortisolsystem, welches, zunächst als Marker der endogenen Depression ausgerufen, unter Einbeziehung des Corticotropinreleasing-Hormons (CRH) und der Neurosteroide als hochdifferenziertes Interface zwischen Endokrinologie, Neurobiologie und Psychiatrie erscheint. – Der experimentelle Ansatz der „gelernten Hilflosigkeit” reproduziert fast alle Depressionsmodelle der biologischen Psychiatrie und konfrontiert uns mit der Tatsache, daß ein psychologisches Paradigma stabile Veränderungen des neurobiologischen Substrates hervorrufen kann. – Vor diesem Hintergrund wird eine kritische Diskussion der heutigen Therapiemöglichkeiten versucht. Therapeutisch steht mit der Einführung neuer psychotherapeutischer Kurzverfahren zusätzlich zu den medikamentösen Strategien ein breiteres Spektrum an Behandlungsmöglichkeiten zur Verfügung, dessen theoretische Grundlagen aber unklar sind. Therapie geht immer noch kaum von neurobiologischen Grundlagen aus, sondern beruht fast ausschließlich auf klinischer Erfahrung, woran auch die Anwendung elaborierter statistischer Verfahren nichts ändert. Die Fragen der differentiellen Indikation von Psycho- und Pharmakotherapie und das ungelöste Problem der adäquaten Dauer antidepressiver Therapie lassen es angezeigt erscheinen, grundlagenorientierte Behandlungswege abseits von Zulassungsstrategien zu suchen.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Langenbeck's archives of surgery 329 (1971), S. 974-976 
    ISSN: 1435-2451
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In einem Modell, bestehend aus einer Rollerpumpe, Wärmeaustauscher, venösem Reservoir and Capillaroxygenator wurden Rattennieren mit Hundevollblut perfundiert. Perfundiert man die Nieren unter konstantem Druck mit 10 ml heparinisiertem Hundevollblut in vitro, so beobachtet man analog zur Ex-vivo-Perfusion einen raschen Anstieg des Strömungswiderstandes. Nach durchschnittlich 25 min kam es zu einem Absinken des Perfusionsvolumens auf unter 0,5 ml/g × min (Kontrolle: homologe Perfusion mit Rattenblut: Perfusionsvolumina um 3 ml/g × min konnten über 60 min aufrechterhalten werden). Befund der xenogenen Perfusion: Makroskopisch: Ödeme, Stauung, Hämorrhagie. Mikroskopisch: Endothelzellennekrosen, insbesondere im Glomerularbereich. Das Modell erlaubte das Hämoperfusat zu varheren: Perfusion mit durch Erhitzen dekomplementierten Hundeserum führte zu einer signifikant verzögerten Abstoßung. Entfernung der Leukocyten and Thrombocyten aus dem Perfusat verstärkte diesen Effekt. Mit einem Perfusat bestehend aus Hundeerythrocyten and hitzedekomplementierten Serum konnten Perfusionsvolumina um 3 ml/g × min erzielt werden, die erst nach 60–90 min Perfusionszeit absinken. Im Serum von Hunden können regelmäßig Antikörper gegen Rattengewebe nachgewiesen werden: Agglutinierende Antikörper gegen Rattenerythrocyten, Leukocyten, Bowie komplementbindende Antikörper gegen Rattenherz, -niere and -leber mit Titerstufen um 1:16–64. Immunfluorescenzuntersuchungen der abgestoßenen Nieren nach Perfusion mit Hundeblut zeigte deutliche Ablagerungen von Hunde-Immunglobulin G sowie Komplement (β 1 c). Nach diesen Ergebnissen muß angenommen werden, daß als ursächlicher Faktor der hyperakuten xenogenen Abstoßungsreaktion die präformierten Antikörper, die zum Zeitpunkt der Transplantation bereits im Empfängerkreislauf zirkulieren, verantwortlich zu machen rind. Vermutlich werden Leukocyten and Thrombocyten sekundär in die ablaufende Antigen-Antikörper-Reaktion mit einbezogen.
    Notes: Summary A model consisting of a roller pump, heat exchanger, venous reservoir and capillary oxygenator was used to perfuse rat kidneys with whole blood from dogs. In kidneys perfused “in vitro” with 10 ml heparinized whole blood of dogs at a constant pressure, one observed a rapid increase of the circulatory resistance analogous to that observed in “ex vivo” perfusion. After approximately 25 min the perfusion volume fell to under 0.5 ml/g per min. (A control reading after homologous perfusion with rat blood showed perfusion volumes of 3 ml/g per min even after 60 min.) Findings after xenogenous perfusion: Macroscopic-oedema, congestion, haemorrhage, microscopic-endothelial cell necrosis, particularly in the glomerular region. The model permitted variations in the perfusate: Perfusion with dog serum de-complemented by heating led to a significant delay in the rejection. Removal of leucocytes and thrombocytes from the perfusate increased this effect. With a perfusate consisting of heat-decomplemented serum with dog erythrocytes, perfusion volumes of 3 ml/g per min could be reached, which fell only after perfusion times of 60–90 min. Antibodies against rat tissue can be traced regularly in dog serum. These are agglutinating antibodies against rat erythrocytes, leucocytes, and complementbinding antibodies against rat heart, liver and kidney, with titres of 1:16–64. Immune-fluorescence examination of rejected kidneys after perfusion with dog blood showed definite deposits of dog-immune globulin G, as well as complement(ß 1 c). On the basis of these observations it can be assumed that the causal factor of the hyper-acute rejection reaction must be the presence of pre-formed antibodies already circulating in the bloodstream of the recipient at the time of the transplantation. Leucocytes and thrombocytes are probably involved later in the course of the antigen-antibody-reaction.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 64 (1991), S. 307-313 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract In order to perform an analysis of nonlinear EEG-dynamics we investigated the EEG of ten male probands during sleep. According to Rechtschaffen and Kales (1968) we scored the sleep-EEG and applied an algorithm, proposed by Grassberger and Proccaccia (1983) to compute the correlation dimension of different sleep stages. The correlation dimension characterizes the dynamics of the EEG signal and estimates the degrees of freedom of the signal under study. We could demonstrate, that the EEG of slow wave sleep stages depicts a dimensionality, which is two units smaller than that of light or REM sleep.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 242 (1993), S. 191-196 
    ISSN: 1433-8491
    Keywords: Sleep EEG ; Deterministic Chaos ; Dimensionality ; Schizophrenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Deterministic chaos could be regarded as a healthy flexibility of the human brain necessary for correct neuronal operations. Several investigations have demonstrated that in healthy subjects the dimensionality of REM sleep is much higher than that of slow wave sleep (SWS). We investigated the sleep-EEG of schizophrenic patients with methods from nonlinear system theory in order to estimate the dynamic properties of CNS. We hypothesized that schizophrenics would reveal alterations of their dynamic EEG features indicating impaired information processing. In 11 schizophrenic patients, the EEG's dimensionality during sleep stages II and REM was reduced. We suggest that such lower dimensional chaotic processes might be associated with an overloading of neuronal networks during sleep and therefore the psychopathology of schizophrenics might be due to impaired complexity of their EEG's dynamics.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 243 (1994), S. 213-213 
    ISSN: 1433-8491
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 241 (1992), S. 241-246 
    ISSN: 1433-8491
    Keywords: Alcohol withdrawal syndrome ; Rating scale
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The alcohol withdrawal syndrome consists of autonomic, neurological and mental symptoms. For its assessment, these symptoms have to be rated in a quantitative and valid manner. We developed a new rating scale for mild and moderate alcohol withdrawal states. Difficulty, discrimination coefficient, internal consistency, and the principal component analysis were assessed. External validation was tested on a separate sample of inpatients. Eight of 12 original items fulfilled test-the-oretical criteria. From these a psychosensory and an autonomic factor have been extracted. This instrument can be used repeatedly for clinical assessment as well as for evaluation of the alcohol withdrawal syndrome in clinical drug studies.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 243 (1994), S. 235-239 
    ISSN: 1433-8491
    Keywords: Intracellular calcium ; Affective disease ; Platelets ; Lymphocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Many studies have demonstrated pharmacologic similarities between platelet and brain 5-HT2 binding sites. Therefore it may be possible to use platelets as a model for the central serotonergic neuron. Accordingly, a previcus report (Kusumi et al. 1991b) about elevated [Ca2+]i after serotonin stimulation in platelets of depressed patients was interpreted as further evidence for enhanced serotonergic sensitivity in depression. However, a very recent study showed an enhanced thrombin-induced platelet Ca2+ response, rather suggesting abnormalities of intracellular Ca2+ regulation in affective disorders. In the present study we have determined 5-HT2-and thrombin-induced Ca2+ responses in platelets and additionally phytohemagglutin (PHA)-induced Ca2+ increase in lymphocytes of medicated depressed patients (8 mono- and 2 bipolar, HRSD〉17) and of ten sex- and age-matched controls. The results showed no significant difference in basal calcium levels between the two groups and no significant difference in the Ca2+ response to thrombin although the response was higher in the patients. The Ca2+ increase after serotonin stimulation in depressed patients was significantly (P〈0.05) higher than in healthy controls. By contrast, the Ca2+ response to PHA in lymphocytes was significantly decreased in the patients. Our data confirm elevated Ca2+ responses after 5-HT2 receptor activation even in medicated depressed patients. However, Ca2+ responses in lymphocytes were decreased. Together with the observations of an enhanced Ca2+ response in platelets after thrombin stimulation, we speculate that the findings rather suggest alterations of [Ca2]i regulation in depression than specific changes of serotonergic sensitivity.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1433-8580
    Keywords: Xenografting ; hyperacute xenograft rejection ; performed natural antibodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In dieser Arbeit sollten die für die HXAR verantwortlichen Serumfaktoren des Empfängertieres - in Interaktion mit Zellen - untersucht werden, wobei insbesondere Wert auf Prüfung verschiedener Serumfraktionen mit bzw. ohne Gehalt an nachweisbaren präformierten natürlichen Antikörpern gelegt wurde. Xenohämoperfusion: Rattennieren wurden isoliert mit Hunde-Vollblut bzw.-Serumfraktionen und verschiedenen peripheren Blutzellen in vitro perfundiert. Als Abstoßungskriterium wurde bei druckkonstanter Perfusion der zeitliche Verlauf der Perfusionsvolumina herangezogen. Perfusat: Serumfraktionen vom Hund: Aus Nativserum wurde mittels Kartonelektrophorese Albumin-, Alpha-2, Beta- und Gamma-Globulin-Fraktionen isoliert. Zellen vom Hund: Aus frischem EDTA-Blut wurde mittels Diff.-Zentrifugation Erythrozyten, Leukozyten und Thrombozyten isoliert. Antikörper in den Fraktionen wurden mit dem Hämagglutinationstest und der Komplement-Bindungs-Reaktion bestimmt. 1. Im Vergleich zum Hundevollblut zeigen die Serumfraktionen bei Xenohämoperfusion längere Perfusionszeiten und höhere Perfusionsvolumina. 2. In den Alpha-2-Globulinfraktionen konnten keine präformierten AK gefunden werden. Trotzdem ergab die Perfusion mit der Alpha-2-Globulinfraktion sowohl in Kombination mit Zellen als auch mit Erythrozyten eine Abstoßungsreaktion. 3. Perfusion mit antikörperhaltigen Serumfraktionen zeigte nur bei gleichzeitiger Anwesenheit von Erythro-, Leuko- und Thrombozyten eine Abstoßungsreaktion. Diese Ergebnisse deuten darauf hin, daß bei der HXAR im wesentlichen zwei unterschiedliche Wirkungsprinzipien eine Rolle spielen: 1. Die Wirkung humoraler, natürlicher Antikörper (in der Beta- und Gamma-Globulinfraktion lokalisiert) im Zusammenwirken mit peripheren Blutzellen; 2. Die Wirkung eines nichtimmunologischen humoralen Faktors (in der Alpha-2-Globulinfraktion lokalisiert), der eine Schädigung des xenogenen Organs offenbar in geringerer Abhängigkeit von der Mitbeteiligung von Zellen hervorruft.
    Notes: Summary The purpose of this paper is to test serum factors which are by interaction with cells responsible for the HXAR. Special stress was laid upon the examination of different serum fractions with or without the presence of preformed natural antibodies. Xenohemoperfusion: Rat kidneys were isolated and perfused in vitro with both whole blood resp. serum fractions and various perpheral cells of dogs. Rejection criterion was the diminishing renal blood flow at a constant pressure of the perfusion. Perfusate: Dog serum fractions were isolated by means of carton electrophoresis into the following fractions: Albumin, alpha-1, alpha-2, beta and gammaglobulin. Dog peripheral blood cells were separated into WBC, RBC and platelets by means of centrifugation and washing of EDTA whole blood. The serum fractions were tested for antibodies using hemagglutination and complement fixation techniques. 1. Hemoperfusion with serum fractions leads to a longer perfusion rate and to higher renal blood flow than perfusion with whole dog blood. 2. No preformed natural antibodies were found in the alpha-2 globulin fractions; however, perfusion with alpha-2 globulin fractions produced a rejection phenomenon both in combination with cells and erythrocytes. 3. Perfusion with serum fractions containing preformed natural antibodies produced a rejection only when WBC and thrombocytes were present. These results suggest that HXAR is induced by two different mechanisms: 1. The effect of humoral natural antibodies (found in the beta and gamma globulin fraction) together with peripheral cells. 2. The effect of a non-immunological humoral factor, found in the alpha-2 globulin fraction, leading to destruction of the xenogeneic organ, obviously to a minor degree dependent on interaction with peripheral cells.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Archives of sexual behavior 9 (1980), S. 477-493 
    ISSN: 1573-2800
    Keywords: diabetes-related erectile impotence ; psychogenic erectile impotence ; premature ejaculation ; psychophysiological sexual profiles ; sexual dysfunction ; impotence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Psychology
    Notes: Abstract Forty-two male patients and their sexual partners were studied: 16 patients with “psychogenic” erectile failure (eight each with the primary and secondary forms), 16 premature ejaculators, and 10 patients with diabetesrelated impotence. Due to the higher mean age of the diabetics, an agematched older control group (eight healthy males and their sexual partners) and an age-matched younger control group (16 healthy males and their sexual partners) were also studied. In an experimental situation various psychophysiological parameters were evaluated. The viewing of films depicting sexual behavior produced psychophysiological reactions in all subjects. The patient groups and the controls differed on the following five parameters: amount of increase in systolic blood pressure, amount of increase in number of spontaneous fluctuations in skin resistance, erection amplitude, latency of erection, and duration of erection. In the diabetic group the three erection parameters were very depressed. In the group with primary psychogenic erectile impotence all five parameters were lower than in the controls, with the greatest difference in spontaneous fluctuations in skin resistance. The psychophysiological profile of the group of patients with secondary psychogenic erectile impotence was surprisingly similar to the profile of the diabetics, with a sharp increase in systolic blood pressure and in spontaneous fluctuations in skin resistance, but very depressed erection parameters. There were no marked differences between the controls and the premature ejaculators. There were only a few correlations between self-rated sexual arousal and psychophysiological measures of sexual stimulation and these were not very high. They were found mainly in the patient groups.
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