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  • Articles: DFG German National Licenses  (2)
  • 1995-1999  (2)
  • Dysphagia.  (1)
  • Amoeba-approach
  • Pulmonary circulation
  • objectives
  • water management
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  • Articles: DFG German National Licenses  (2)
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  • 1
    ISSN: 1432-1238
    Keywords: Key words Haemoconcentration ; Haemodilution ; Pressure-flow relationship ; Pulmonary circulation ; Pulmonary vascular flow resistance ; Pulmonary vascular hypertension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: Pulmonary vascular flow resistance depends on blood viscosity, mainly due to haematocrit, and on vessel dimensions determining blood volume in this highly compliant vascular bed. We, therefore, evaluated the interaction between haematocrit, blood flow, and transpulmonary vascular pressure gradient under conditions of controlled pulmonary blood volume. Design: Experimental study in isolated zone-III rabbit lungs perfused with autologous blood. Setting: Laboratory for experimental studies. Interventions: Stepwise and independent variation of flow (50, 100, and 200 ml/min), pulmonary blood volume (increments of 2.5 ml and 5 ml imposed by changes of left atrial pressure), and haematocrit (0–50 %) varied by haemodilution (Krebs-Henseleit/albumin) or haemoconcentration (centrifugation). Measurements: Pulmonary arterial, left atrial, and airway pressures as well as reservoir volume (reflecting reciprocal changes of lung blood volume) and lung weight. Results: Haemodilution from the normal haematocrit (32 %) to 10 % at constant pulmonary blood volume and flow decreased flow resistance only slightly, whereas haemoconcentration (50 %) increased flow resistance up to 130 %. At the same time increments of in pulmonary blood volume of 2.5 and 5 ml (approx. 15 and 30 % of normal pulmonary blood volume) at constant haematocrit significantly shifted downwards pressure-flow relationships for all investigated haematocrits (0–50 %). Conclusions: Because of the multiple interrelationships between haematocrit, blood flow and pulmonary blood volume, haematocrit effects on pulmonary flow resistance and pressure-flow relationships in the pulmonary vasculature should be studied at controlled blood volume. While haemodilution only has minor effects, haemoconcentration changes pressure-flow relationships markedly. Pulmonary blood volume has a major impact on slope and position of pressure-flow relationships for all haematocrits investigated.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Der Chirurg 70 (1999), S. 741-746 
    ISSN: 1433-0385
    Keywords: Key words: Cricopharyngeal diverticulum ; Zenker's ; Upper esophageal sphincter ; Swallowing ; Dysphagia. ; Schlüsselwörter: Cricopharyngeales Divertikel ; Zenker-Divertikel ; oberer Oesophagussphincter ; Schlucken ; Dysphagie.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Störungen der pharyngooesophagealen Phase des Schluckens, inkl. Zenker-Divertikel, resultieren aus Änderungen der neuromuskulären Vorgänge, die beim Kauen, zu Beginn des Schluckens und bei der Beförderung der Speise vom Oropharynx in den cervicalen Oesophagus beteiligt sind. Obwohl eine Reihe von Mechanismen zur Erklärung der Entstehung des Zenker-Divertikels vorgeschlagen wurde – inkl. Störung der Sphincterkoordination, Schlucken gegen einen geschlossenen oberen Oesophagussphincter (OÖS), versagende OÖS-Relaxation, hypertensiver „spastischer“ OÖS –, weisen neuere Untersuchungen darauf hin, daß eine veränderte Compliance des cricopharyngealen Segments an der Pathophysiologie des Zenker-Divertikels beteiligt ist. Manometrisch kann eine Relaxation auch dann vorkommen, wenn anatomisch keine Öffnung erfolgt ist. Eine fehlende Koordination ist ungewöhnlich. Complianceänderungen sind mit einer speziellen cricopharyngealen Manometrie nachweisbar als Verminderung der Sphincteröffnung oder als Erhöhung des Boluspassagedrucks. Diese Störungen normalisieren sich nach Diverticulektomie und cricopharyngealer Mytomie.
    Notes: Summary. Disorders of the pharyngoesophageal phase of swallowing, including Zenker's diverticulum, result from alterations of the neuromuscular events involved in chewing, initiation of swallowing, and propulsion of the material from the oropharynx into the cervical esophagus. Although a number of mechanisms have been postulated to explain the genesis of Zenker's divertcula, including sphincter incoordination, swallowing against a closed UES, failed UES relaxation, and a hypertensive spastic upper sphincter, recent evidence suggests that the pathophysiology of Zenker's diverticula involves altered compliance of the cricopharyngeal segment. Manometric relaxation may occur in the absence of anatomic opening. Incoordination is uncommon. Altered compliance is detectable with specialized cricopharyngeal manometric recording as impaired sphincter opening or a raised intrabolus pressure. Both return to normal following diverticulectomy and cricopharyngeal myotomy.
    Type of Medium: Electronic Resource
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