Comportamento del CO2 totale del tessuto muscolare in rapporto al CO2 totale del sangue

Zusammenfassung Der CO₂-Gehalt des gesamten Muskelgewebes ist (beim Kaninchen) dem CO₂-Gehalt des Blutes proportional. Die Werte im Muskel und im Blut verhalten sich etwa wie 1:2. Der Fehler des respiratorischen Quotienten durch eine Änderung der Alkalireserve läßt sich errechnen. Die vorliegenden Resultate stimmen gut mit den früheren Befunden vonShaw überein.     

Sul comportamento della sostanza fondamentale in membrane connettivali di ratto albino durante il passaggio di una soluzione salina

Summary The author has studied some details of the passage of saline through connective membranes of normal albino young rats. A mucopolysaccharide is present in such membranes which can be removed soon after addition of hyaluronidase and, at a much slower rate, by the mere passage of fluids through the tissue. Such mucopolysaccharide, most likely hyaluronic acid, seems to be present in quantities not too different from one membrane to another and it appears to be bound to some other tissue microstructure by means of rather loose chemical bonds. Once the mucopolysaccharide removed, the hydration of some other substrate probably takes place, thus causing the free interstices to get narrower with consequent decrease in the flowing velocity of the saline.     

Engineering of arteries in vitro

This review will focus on two elements that are essential for functional arterial regeneration in vitro: the mechanical environment and the bioreactors used for tissue growth. The importance of the mechanical environment to embryological development, vascular functionality, and vascular graft regeneration will be discussed. Bioreactors generate mechanical stimuli to simulate biomechanical environment of arterial system. This system has been used to reconstruct arterial grafts with appropriate mechanical strength for implantation by controlling the chemical and mechanical environments in which the grafts are grown. Bioreactors are powerful tools to study the effect of mechanical stimuli on extracellular matrix architecture and mechanical properties of engineered vessels. Hence, biomimetic systems enable us to optimize chemo-biomechanical culture conditions to regenerate engineered vessels with physiological properties similar to those of native arteries. In addition, this article reviews various bioreactors designed especially to apply axial loading to engineered arteries. This review will also introduce and examine different approaches and techniques that have been used to engineer biologically based vascular grafts, including collagen-based grafts, fibrin-gel grafts, cell sheet engineering, biodegradable polymers, and decellularization of native vessels.     

New-forming retinal synapses in vitro

Riassunto Cellule di abbozzo oculare di embrione di pollo di 4 giorni di incubazione sono state disgregate, riaggregate e coltivate in vitro per 25 giorni. Al m.e. è risultato un fitto neuropilo ricco di sinapsi tra cui i «synaptic ribbons» caratteristici delle cellule fotorecettrici. Questi risultati sono una prima sicura documentazione di sinapsi formate ex novo in vitro con nuova associazione di cellule.     

New intermediates in phaeomelanogenesis in vitro

Riassunto Mediante esperimenti in vitro, è stato accertato che i primi stadi della biosintesi delle feomelanine conducono alla formazione di derivati diidrobenzotiazinici, ai quali sono state assegnate le strutture III e IV.

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This investigation was supported by a grant from the Laboratorio di Chimica e Fisica per lo Studio delle Molecole di Interesse Biologico del C.N.R., Napoli.     

Antifibrinolytic properties of oxyphenbutazone in vitro

Summary The authors found that oxyphenbutazone (Tanderil^®) added to culture medium, in amounts giving a final concentration of 10–100 g/ml, causes a decrease in the liberation of fibrinolytic agents from explants of various tissues cultured in vitro.     

Maintenance of visual cells in vitro

Résumé Des fragments de rétine et des cellules visuelles isolées de la grenouilleRana pipiens ont été cultivés dans la chambre de Rose. Bien qu'une dégénérescence morphologique des segments extérieurs des cellules visuelles ait été observée pendant la culture, le pouvoir de réfraction normal et la présence du pigment visuel ont été constatés dans ces segments, les segments intérieurs avec leurs noyaux étant conservés. Mais, l'intensité du pigment visuel a été plus faible que dans la rétine fraîche. Ces résultats montrent que la cellule individuelle du photorécepteur se prête à l'étude physiologiquein vitro.

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Aided by a grant from the National Society for the Prevention of Blindness.     

Noradrenalin-Freisetzung aus dem Hypothalamus in vitro

Summary Rat hypothalami were isolated and incubated at 37 °C in Ringer solution. Both calcium and acetylcholine enhance the release of noradrenaline. The effect of acetylcholine is dependent on the presence of calcium ions.

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Durchgeführt mit. Unterstützung der Deutschen Forschungsgemeinschaft.     

Fenofibrate inhibits angiogenesis in vitro and in vivo

Fenofibrate, a peroxisome proliferator-activated receptor (PPAR)-alpha activator, used as a normolipidemic agent, is thought to offer additional beneficial effects in atherosclerosis. Since angiogenesis is involved in plaque progression, hemorrhage, and instability, the main causes of ischemic events, this study was designed to evaluate the action of fenofibrate on angiogenesis. Our results show that fenofibrate (i) inhibits endothelial cell proliferation induced by angiogenic factors, followed at high concentrations by an increase in apoptosis, (ii) inhibits endothelial cell migration in a healing wound model, (iii) inhibits capillary tube formation in vitro, and (iv) inhibits angiogenesis in vivo. Concerning the mechanism of action, the inhibition of endothelial cell migration by fenofibrate can be explained by a disorganization of the actin cytoskeleton. At the molecular level, fenofibrate markedly decreased basic fibroblast growth factor-induced Akt activation and cyclooxygenase 2 gene expression. This inhibition of angiogenesis could participate in the beneficial effect of fenofibrate in atherosclerosis.     

Culture of nucellar tissue ofCitrus in vitro

Zusammenfassung Wucherungen, die in der vorliegenden Arbeit als «Pseudobulbillen» bezeichnet worden sind, erschienen zuerst in Kulturen vonCitrus-Nucellargewebe auf einem künstlichen Nährboden. Diese Bulbillen sind durch zahlreiche Passagen in einem genau definierten Nährboden seit einem Jahr erhalten geblieben.