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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 195 (1997), S. 539-555 
    ISSN: 1432-0568
    Keywords: Key words Birds ; Tract tracing ; Optic tectum ; Retinal fibers ; Ontogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The optic tectum of the pigeon (Columba livia) is marked by morphological dorso-ventral and left-right differences. Both features seem to be related to functional specializations, but the responsible developmental mechanisms are unclear. Since the visual system becomes functional only after hatching, the developmental processes might be extended into the post-hatching period. The development of the asymmetries in the tectofugal system, however, depends on an asymmetric light stimulation acting already before hatching. As a first attempt to resolve this discrepancy, we examined the ontogeny of the retinotectal system by labeling the developing retinal projection with cholera toxin subunit B, in conjunction with an analysis of the cytoarchitectonic differentiation of the optic tectum. The data demonstrate that the first fibers to penetrate all retinoreceptive tectal layers could be observed from embryonic day 15 onwards, indicating that visual information could in principle be already processed before hatching. The afferent projection already exhibited the adult lamination pattern directly at the beginning of the invasion of the tectal layers; a surprising finding, since at that time the lamination pattern of the tectal layers did not have an adult appearance. The differentiation of the outer retinoreceptive laminae started only when the whole optic tectum was occupied by retinal fibers, 4 days after hatching, and was finished a week later. The dorso-ventral differences in the thickness of layers 4 and 5 were not apparent before the first week after hatching. The late appearance of these differences indicates that their maturation may be influenced by retinal input.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 66 (1988), S. 1040-1040 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 56 (1978), S. 1179-1183 
    ISSN: 1432-1440
    Keywords: Digoxin ; Digitoxin ; Intoxikation ; Hämoperfusion mit beschichteter Aktivkohle ; Hämodialyse ; Entgiftung ; Digoxin ; digitoxin ; intoxication ; activated charcoal ; hemoperfusion ; hemodialysis ; detoxification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Since there is no widely used causal means of reducing the severity of massive digitalis intoxication the capability of hemoperfusion with coated activated charcoal to remove toxicologically relevant amounts of digoxin and digitoxin was evaluated in vitro and in man. At a blood flow rate of 100 ml/min the digoxin clearance by hemoperfusion in vitro was 51±8 ml/min in comparison to 24.3±11.3 ml/min by hemodialysis. The average hemoperfusion clearance of digitoxin was 31.7±13.4 ml/min, whereas almost no digitoxin was removed by hemodialysis. These clearance values point to the ability of hemoperfusion of eliminating digitalis glycosides from the blood. They do not clarify the essential question whether it is possible to lower the toxic concentrations in the tissues. In two patients being on hemoperfusion for other reasons, 0.5 mg digoxin were injected intravenously as a bolus 1 h prior to the beginning of hemoperfusion and 0.125 mg/h were infused continuously over 4h simultaneously with hemoperfusion. By an average digoxin clearance of 77 ml/min, only 5 and 4.5% of the dose given were removed by this procedure. In 2 patients receiving digitoxin under the same trial conditions an average of 24% of the digitoxin load were eliminated by 4 to 6 h hemoperfusion period although the clearance values obtained were below the clearance for digoxin. The lack of effectiveness in eliminating toxicological relevant amounts of digoxin is due to the quite high distribution volume which results in high tissue concentrations and low blood concentrations of the drug. On the other hand the effective removal of digitoxin is due to the appreciably smaller distribution volume and suggests that hemoperfusion may be a valuable method of rapid reversal of advanced digitoxin toxicity in man.
    Notes: Zusammenfassung Bisher gibt es keine allgemein anwendbare kausale Therapie lebensbedrohlicher Digitalis-Intoxikationen. Daher wurde in vitro und in vivo beim Menschen untersucht, ob die Hämoperfusion mit beschichteter Aktivkohle toxikologisch relevante Mengen von Herzglykosiden zu eliminieren vermag. Bei einer Blutumlaufgeschwindigkeit von 100 ml/min betrug in vitro die Digoxin-Clearance durch Hämoperfusion 51±8 ml/min, im Vergleich zu 24,3±11,3 ml/min durch die Hämodialyse. Für Digitoxin fand sich eine Clearance von 31,7±13,4 ml/min durch Hämoperfusion, während bei Hämodialyse kein meßbarer Anteil des Glykosids eliminiert wurde. Diese Clearence-Werte lassen erwarten, daß die Herzglykoside durch die Hämoperfusion aus dem Blut eliminiert werden, ohne daß allerdings durch die in vitro-Untersuchung eine Aussage möglich ist, ob toxische Glykosidkonzentrationen im Gewebe hierdurch gesenkt werden können. Bei 2 Patienten, bei denen aus anderen Gründen eine Hämoperfusion durchgeführt wurde, wurde Digoxin nach einer Bolusinjektion von 0,5 mg mit einer konstanten Geschwindigkeit von 0,125 ml/h infundiert und der Effekt der Hämoperfusion ermittelt. Bei einer mittleren Digoxin-Clearance von 77 ml/min wurden durch eine 4- bzw. 6-stündige Hämoperfusion nur 5% und 4,5% der applizierten Dosis eliminiert. Dahingegen wurden bei gleichem Vorgehen bei 2 anderen Patienten im Mittel 24% der verabreichten Digitoxin-Dosis durch eine 4- bzw. 6stündige Hämoperfusion eliminiert, obwohl die Digitoxin-Clearance deutlich unter der Digoxin-Clearance lag. Die geringe Effektivität der Hämoperfusion bei der Digoxinelimination ist auf das große Verteilungsvolumen dieses Glykosids zurückzuführen, welches durch hohe Gewebe-und niedrige Plasmakonzentrationen gekennzeichnet ist. Andererseits ist die gute Wirkung der Hämoperfusion in der Elimination von Digitoxin auf das deutlich kleinere Verteilungsvolumen zurückzuführen und läßt den Einsatz der Hämoperfusion bei lebensbedrohlicher Digitoxin-Intoxikation sinnvoll erscheinen.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 58 (1980), S. 847-849 
    ISSN: 1432-1440
    Keywords: Diabetes insipidus ; Clofibrat ; Chlorpropamid ; Diabetes insipidus ; Clofibrate ; Chlorpropamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A patient with severe idiopathic diabetes insipidus, complicated by diabetes mellitus, was first treated with a combination of clofibrate and chlorpropamide. Urine volume dropped from 18 litres/day ( $$C_{H_2 O} $$ =10.5 ml/min) to 3.1–5.1 litres/day ( $$C_{H_2 O} $$ =-0.1-+1.1 ml/min) under treatment. Ten months after the beginning of therapy treatment was maintained with chlorpropamide alone; no significant rise in urine volume was observed. After 18 months when therapy was stopped for 5 days urine volume rose to 11.7 litres/day maximum ( $$C_{H_2 O} $$ =6.6 ml/min). No obvious side effects occurred under treatment during a follow up for over 18 months. Serum levels for arginine vasopressin before and under treatment were below 1.0 pg/ml. Determination of free water clearance ( $$C_{H_2 O} $$ ) proved to be a highly sensitive and simple method for follow up controls. It is discussed whether the coincidental manifestation of diabetes insipidus and diabetes mellitus may be caused by a single molecular lesion. This hypothesis is supported by data which imply that in both diseases chlorpropamide acts via a common molecular mechanism, the blocking of endogenous prostaglandin E2 biosynthesis. Finally a treatment with oral “non-hormonal” drugs like clofibrate and chlorpropamide should be taken into consideration in some cases of diabetes insipidus as is demonstrated by this case report.
    Notes: Zusammenfassung Ein Patient mit schwerem idiopathischem Diabetes insipidus, assoziiert mit einem zuvor manifesten Diabetes mellitus, wurde zunächst mit einer Kombination von Clofibrat und Chlorpropamid behandelt. Unter Therapie sank die Urinauscheidung von 18 Litern/Tag ( $$C_{H_2 O} $$ =10,5 ml/min) vor auf Werte von 3,1–5,1 Litern/Tag ( $$C_{H_2 O} $$ =-0,1-+1,1 ml/min) unter Therapie. Zehn Monate nach Therapiebeginn wurde mit Chlorpropamid alleine weiterbehandelt, ohne daß ein signifikanter Anstieg des Urinvolumens festgestellt wurde. Bei einem Therapieauslaßversuch kam es nach 18 Monaten zu einem Anstieg des Urinvolumens auf maximal 11,7 Liter/Tag ( $$C_{H_2 O} $$ =6,6 ml/min). Während der gesamten Therapiedauer wurden keine Nebenwirkungen beobachtet. Serumwerte für Argininvasopressin lagen vor Therapiebeginn und unter Therapie sämtlich unter 1,0 pg/ml. Die Bestimmung der freien Wasserclearance ( $$C_{H_2 O} $$ ) erwies sich als ein empfindlicher Parameter zur Therapiekontrolle. Es wird diskutiert, ob der gleichzeitigen Manifestation von Diabetes insipidus und Diabetes mellitus eine Störung der endogenen Prostaglandin E2 Biosynthese zu Grunde liegen könnte; deren Hemmung in Pankreas und Niere wird als gemeinsamer molekularer Mechanismus für die Wirkung von Chlorpropamid bei beiden Erkrankungen angesehen. Anhand der vorliegenden Kasuistik wird dargelegt, daß in bestimmten Fällen von Diabetes insipidus eine Therapie mit oral wirksamen „nicht-hormonellen“ Pharmaka wie Clofibrat und Chlorpropamid erwogen werden sollte.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1238
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 22 (1996), S. S42 
    ISSN: 1432-1238
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Conclusions The results are consistent with the hypothesis that septic mediators are bound to the surface of polysulfone membranes, which become saturated after 7–9 hrs. It might be necessary to change dialysis filters frequently during CVVHD to prevent membrane saturation and to achieve a persistent increase in MAP.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1084
    Keywords: Scintigraphy ; Gastric emptying ; Motility ; Chronic gastritis ; Dyspepsia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To record gastric peristalsis using a conventional scintigraphic gastric emptying test the frame rate was increased to 1 frame per 3 s at 10, 30, and 50 min postprandially. The gastric contraction frequency was obtained from the first harmonic of a Fourier transform of a gastric region of interest (ROI) curve. The propagation of gastric contractions was better revealed from computed functional images of the phase and amplitude distribution as compared with the multiple scintigraphic images. The maximal count-rate changes per pixel were calculated as an estimate of the most prominent regional contractile activity of the gastric wall. Among 12 patients with chronic gastritis the group with more severe dyspeptic complaints (n = 6) had significantly higher count-rate changes per pixel when compared with the group with minor complaints (20.0, 21.1 and 14.2 vs 12.9, 12.0, and 10.4 counts/pixel × s at 10, 30, and 50 min, respectively; p 〈 0.05). The mean half-times of gastric emptying (61, SD 11 vs 54, SD 13 min) and the mean gastric contraction frequencies (2.99, SD 0.19; 3.09, SD 0.33; 3.07, SD 0.10 vs 3.15, SD 0.15; 3.17, SD 0.13; 3.23, SD 0.20 cycles/min at 10, 30, and 50 min, respectively) did not show significant differences between both groups. Our preliminary results agree with the hypothesis of the occurrence of more powerful, nonexpulsive gastric-wall contractions in patients with more severe dyspeptic complaints. Hence, additional quantification of gastric motility allowed a more detailed evaluation of gastric-motor-activity disorders that were for so long not accessible to conventional gastric-emptying tests.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochemical and Biophysical Research Communications 182 (1992), S. 617-623 
    ISSN: 0006-291X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism 1125 (1992), S. 13-20 
    ISSN: 0005-2760
    Keywords: (Rat liver) ; Carrier mediated transport ; Fatty acid ; Membrane fatty acid binding protein ; Monoclonal antibody
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background IgE-dependent activation of mast cells (MCs) is a key pathomechanism of type I allergies. In contrast, allergen-specific IgG Abs are thought to attenuate immediate allergic reactions by blocking IgE binding and by cross-linking the inhibitory Fcγ receptor IIB on MCs.Objectives To establish a defined in vitro system using human MCs to study the biological activity of allergens and to investigate the role of allergen-specific IgE and IgG.Methods Purified human intestinal MCs sensitized with different forms of specific IgE Abs were triggered by monomeric and oligomeric forms of recombinant Bet v 1, the major birch pollen allergen, in the presence or absence of allergen-specific IgG Abs.Results MCs sensitized with an anti-Bet v 1 IgE mAb or sera obtained from birch pollen allergic patients released histamine and sulphidoleukotrienes after exposure to oligomeric Bet v 1. Monomeric Bet v 1 provoked mediator release only in MCs sensitized with patients sera but not in MCs sensitized with anti-Bet v 1 IgE mAb. Interestingly, MC activation could be induced by supercross-linking of monomeric Bet v 1 bound to monovalent IgE on MCs with a secondary allergen-specific IgG pAb. By using IgG F(ab′)2 fragments we provide evidence that this effect is not a result of IgG binding to Fcγ receptors.Conclusion This assay represents a new tool for the in vitro study of MC activation in response to natural and genetically modified allergens. Fcɛ receptor I supercross-linking by allergen-specific IgG Abs provides a possible new mechanism of IgG-dependent enhancement of type I allergic reactions.
    Type of Medium: Electronic Resource
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