1,117 research outputs found

    Wirkortäquilibration, Anschlagzeit, "time to peak effect": Bedeutung pharmakokinetisch-dynamischer Prinzipien für die tägliche klinische Praxis

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    Zusammenfassung: In der anästhesiologischen Pharmakologie spielen im Gegensatz zur internistischen Pharmakologie "Non-steady-state-Phänomene" eine herausragende Rolle. Ihr Verständnis ist eine Conditio sine qua non für die sichere und effiziente Applikation von anästhesierelevanten Medikamenten. Insbesondere die Verfügbarkeit der "optimierten target controlled infusion" ("optimized TCI"), von TCI-Systemen mit Ansteuerung des Effektkompartiments und dem relativ geringen Dosierungsspielraum bei "conscious sedation" unter erhaltener Spontanatmung verlangen von Anästhesisten, sich mit dem Konzept des Konzentrationsverlaufes am Wirkort auseinander zu setzen. Der Leser wird in die grundlegende Problematik eingeführt. Anwendungen der Prinzipien bei der Applikation von Muskelrelaxanzien, Propofol mit TCI-Systemen, volatilen Anästhetika und Opiaten werden erläuter

    Photosynthetic planulae and planktonic hydroids: contrasting strategies of propagule survival

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    Settlement delays can be important to prevent propagule waste when proper settling substrates are not immediately available. Under laboratory conditions, the planulae of Clytia viridicans underwent two alternative developmental patterns. Some settled on the bottom, forming a hydranth-gonotheca complex that produced up to four medusae and later either degenerated or gave rise to a hydroid colony. Other planulae settled right below the air-water interface, forming floating colonies that eventually fell to the bottom and settled. Halecium nanum released planulae with a rich population of symbiotic zooxanthellae that survived into a rearing jar for three months. After a long period of apparent quiescence (possibly fuelled by photosynthetic activities of zooxanthellae) the planulae produced new colonies. Both photosynthetic planulae and settlement at the interface air-water allow a delay in the passage from a planktonic to a fully functional benthic life

    Hidromedusas profundas del Mediterráneo: Un estudio que incluye la descripción de dos nuevas especies recolectadas en cañones submarinos del Mediterráneo Occidental

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    Two new species of hydromedusae (Foersteria antoniae and Cunina simplex) are described from plankton collected in sediment traps placed in the Lacaze-Duthiers Submarine Canyon and along Banyuls-sur-Mer coast (northwestern Mediterranean). The Mediterranean hydromedusan deep-water fauna contains 41 species which represent 45.5 % of the world-wide deep-sea hydromedusae fauna (90) and 20% of the total number of Mediterranean hydromedusae (204). The Mediterranean deep-water hydromedusan fauna is characterised by a large percentage of holoplanktonic species (61%), mainly Trachymedusae. Nevertheless, contrary to the general opinion, the percentage of meroplanktonic species is equally high. The most original features of this fauna lies however in the importance of the number of endemic species (22%) and in the fact that the majority of them are meroplanktonic Leptomedusae with a supposed bathybenthic stage. Some of the endemic species could still represent relics of the primitive Tethys fauna having survived to the Messinian crisis. The origin of the Mediterranean deep-water hydromedusan fauna is discussed and a general hypothesis is proposed.Se describen dos especies nuevas a partir de ejemplares recolectados mediante trampas de sedimento del cañón submarino de Lacaze-Duthiers situado en frente de la costa de Banyuls-sur-Mer (Mediterráneo noroccidental). La fauna profunda de hydromedusas en el Mediterráneo contiene 41 especies que representan 45.5 % de la fauna mundial del grupo y el 20% de la fauna de hydromedusas del Mediterráneo. La fauna Mediterránea de hydromedusas profundas se caracteriza por un gran porcentaje de especies holoplanctónicas (61%), fundamentalmente Trachymedusas, sin embargo, contrario a la opinión generalizada, el porcentaje de especies meroplanctónicas es igualmente importante (39%). La característica más interesante de esta fauna es el número de especies endémicas (22%) y el hecho de que la mayoría de estas especies son meroplanctónicas (Leptomedusas) con una supuesta fase bentónica. Algunas de estas especies endémicas, podrían ser especies relictas (endémica insular) de la fauna primitiva del Tetis que sobrevivieron a la crisis Mesiniana. Se discute el origen de la fauna de hydromedusas profundas en el Mediterráneo y se presenta una nueva hipótesis

    Approaches to the ethology of hydroids and medusae (Cnidaria, Hydrozoa)

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    The behavioural patterns of 26 species of Antho- and Leptomedusae (with or without medusa stage) were investigated by video recordings. The analysed activities were: answers to mechanical stimuli, prey capture and ingestion, digestion, egestion, and swimming. The quantity of behavioural patterns identified in the small number of hydrozoan diversity studied so far is sufficient to demonstrate that these supposedly "simple" animals have evolved a complex array of responses to both external and internal stimuli

    Cortisol response to critical illness:Effect of intensive insulin therapy

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    Context: Both excessive and insufficient activation of the hypothalamic-pituitary-adrenal axis in response to critical illness is associated with increased mortality. Objective: The objective of the study was to study the effect of intensive insulin therapy, recently shown to reduce mortality and morbidity of critically ill patients, on the cortisol response to critical illness. Design: This was a preplanned subanalysis of a large randomized, controlled study measuring serum total cortisol, cortisol-binding globulin, and albumin and calculating free cortisol levels. Setting: The study was conducted at a university hospital surgical intensive care unit. Patients: Four hundred fifty-one critically ill patients dependent on intensive care for more than 5 d and 45 control subjects matched for gender, age, height, and weight participated in this study. Intervention: The intervention was strict blood glucose control to normoglycemia with insulin. Results: Total and calculated free cortisol levels were equally elevated upon admission in both patient groups and thereafter were lower in intensive insulin-treated patients. Lower cortisol levels statistically related to the outcome benefit of intensive insulin therapy. Cortisol-binding globulin levels and structure were affected by critical illness but not insulin therapy, and neither were albumin levels. Administration of hydrocortisone in so-called replacement dose resulted in severalfold higher total and free cortisol levels, indicating that reevaluation of the doses used is warranted. Conclusions: Lower serum cortisol levels in critically ill patients receiving intensive insulin therapy statistically related to improved outcome with this intervention. The lower cortisol levels were not related to altered cortisol-binding capacity.</p

    Cortisol response to critical illness:Effect of intensive insulin therapy

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    Context: Both excessive and insufficient activation of the hypothalamic-pituitary-adrenal axis in response to critical illness is associated with increased mortality. Objective: The objective of the study was to study the effect of intensive insulin therapy, recently shown to reduce mortality and morbidity of critically ill patients, on the cortisol response to critical illness. Design: This was a preplanned subanalysis of a large randomized, controlled study measuring serum total cortisol, cortisol-binding globulin, and albumin and calculating free cortisol levels. Setting: The study was conducted at a university hospital surgical intensive care unit. Patients: Four hundred fifty-one critically ill patients dependent on intensive care for more than 5 d and 45 control subjects matched for gender, age, height, and weight participated in this study. Intervention: The intervention was strict blood glucose control to normoglycemia with insulin. Results: Total and calculated free cortisol levels were equally elevated upon admission in both patient groups and thereafter were lower in intensive insulin-treated patients. Lower cortisol levels statistically related to the outcome benefit of intensive insulin therapy. Cortisol-binding globulin levels and structure were affected by critical illness but not insulin therapy, and neither were albumin levels. Administration of hydrocortisone in so-called replacement dose resulted in severalfold higher total and free cortisol levels, indicating that reevaluation of the doses used is warranted. Conclusions: Lower serum cortisol levels in critically ill patients receiving intensive insulin therapy statistically related to improved outcome with this intervention. The lower cortisol levels were not related to altered cortisol-binding capacity.</p
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