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  • 1
    ISSN: 1433-8580
    Keywords: Bubble-flow-meter ; Blood flow measurement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The construction of a simple bubble-flow-meter is described. The instrument has the following features: 1. automatic bubble injection, 2. precise measurement of the bubble passage time by a digital counter, 3. quasicontinuous registration of the flow rate, 4. alternative run with clear fluid (water) and coloured fluid (blood), 5. low volume, 6. closed measuring system for measurements in low and high pressure systems.
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  • 2
    ISSN: 1433-8580
    Keywords: Muscle metabolism ; exercise ; insulin ; glucose uptake ; lipolysis ; Muskelstoffwechsel ; Insulin ; Glukoseaufnahme ; Muskelkontraktion ; Basislipolyse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Am Modell der perfundierten Hinterpfote der Ratte wurde der Muskelstoffwechsel unter Ruhebedingungen und während elektrischer Reizung in Gegenwart und Abwesenheit von Insulin untersucht. Die basale Glukoseaufnahme wurde sowohl durch Muskelkontraktionen als auch durch physiologische Mengen von Insulin um den Faktor 3 gesteigert. Insulin und Muskelkontraktionen wirkten additiv auf die Glukoseaufnahme. Muskelarbeit führte zu einem 7 – 8fachen Anstieg der Lactatproduktion, unabhängig, ob Insulin dem Perfusionsmedium zugefügt war oder nicht. Die arbeitsbedingte Lactatproduktion überstieg die gleichzeitige Glukoseaufnahme und korrespondierte mit einem signifikanten Abfall des Muskelglykogen-Gehaltes. Muskelkontraktionen führten zu einer gesteigerten Lipolyse. In Ruhe hatten weder Corticosteron noch Thysoxin einen Einfluß auf die Lipolyse. Zugabe von Serum zum Perfusionsmedium bewirkte dagegen eine um den Faktor 2 gesteigerte Lipolyse, gemessen an der Gycerinproduktion. Aus den Ergebnissen wird geschlossen, daß die Glykogenolyse über das Phosphorylasesystem durch kurzdauernde Muskelkontraktionen alleine prompt zu stimulieren ist, die Lipolyse dagegen nicht.
    Notes: Summary The influence of insulin on muscle metabolism at rest and during electrically stimulated exercise was examined in the perfused rat hind limb. Basal glucose uptake of muscle tissue was enhanced threefold both by muscle contraction an by addition of physiological amounts of insulin. A further increase in glucose uptake was seen, when muscle was exercised in the presence of insulin. Lactate production rose 7 – 8fold by contractions. Insulin had no additional effect on lactate production during exercise. The work-induced lactate output exceeded glucose uptake, corresponding to a significantly reduced glycogen content after exercise. Basal lipolysis was not stimulated by muscle contractions. At rest the addition of both corticosterone and thyroxine did not increase the basal lipolysis. Yet, glycerol release rose twofold by the addition of serum to the perfusion medium. It is assumed that in the perfused rat hind limb glycogenolysis will promptly be stimulated by muscle contractions, whereas lipolysis can not be enhanced by exercise alone.
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  • 3
    ISSN: 1433-8580
    Keywords: SEM ; oxygenator ; silicone rubber ; thrombus ; filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Despite adequate heparinization, thrombus formation occurs at the blood/foreign material interface. Depending on the part of the device, the material and the blood flow, the amount and the components of thrombi vary greatly. This is not dangerous by itself but clots can be expelled downstream and damage the lungs, brain, kidney and retina. Interposition of a filter may prevent risks of embolization. The present paper reports the scanning electron microscope study carried out on the Awad oxygenator after use during prolonged extracorporeal circulation on 13 dogs. No filter has been inserted in the circuit for the first six experiments. A screen filter (4) or a polyurethane foam filter (3) was employed in the following ones.
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  • 4
    ISSN: 1433-8580
    Keywords: Erythrocytes ; Angiotensinase ; Enzyme-Kinetics ; Erythrozyten ; Angiotensinase ; Enzymkinetik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In menschlichen Erythrozytenfraktionen (hämoglobinfreie Erythrozytenmembranen; membranfreies Hämolysat; durch DEAE-Cellulose von Hämoglobin befreite Enzym-Protein-Fraktion) wurde mit Hilfe eines NADH-abhängigen optischen Tests mit Asparaginyl1-Angiotensin II-amid als Substrat die Aminopeptidaseaktivität untersucht. 1. Durch fraktionierte Ammoniumsulfatfällung wurden sechs Unterfraktionen aus der Enzym-Protein-Fraktion gewonnen. Mit Hilfe von enzymkinetischen Untersuchungen bei drei verschiedenen pH-Werten (pH 5,0; 7,0; 8,0) mit und ohne Zusatz von zwei verschiedenen Effektoren (Na2EDTA und Ca++) gelang der Nachweis von sechs verschiedenen Enzymen. 2. Durch die Inhibitoren Diisopropylfluorphosphat und p-Chloromercuribenzoat wurde bei verschiedenen pH-Werten (pH 5,0; 6,5; 7,0; 8,0 bzw. 6,5; 7,0; 8,0) eine signifikante Inaktivierung der Aminopeptidaseaktivität des membranfreien Hämolysats beobachtet. 3. Das Temperaturoptimum für die Aminopeptidaseaktivität des Hämolysats lag bei 47°C. Bei 37°C trat nach einer Inkubation von 2 Stunden ein Aktivitätsverlust von 20% ein.
    Notes: Summary Aminopeptidase activity of three fractions of human erythrocytes (membranes free of hemoglobin; hemolysate free of membranes; enzyme protein fraction made free of hemoglobin by DEAE-cellulose) was measured by a NADH dependent optical test using asparaginyl1-angiotensin II-amide as substrate. 1. From the enzyme protein fraction 6 subfractions were obtained by (NH4)2SO4 precipitation. By measuring enzyme kinetics at three different pH-values (pH 5,0; 7,0; 8,0) with and without addition of the effectors Na2EDTA and Ca++ the existence of 6 different enzymes could be demonstrated. 2. The aminopeptidase activity of the hemolysate made free of membranes could be inhibited by diisopropylfluorphosphate and p-chloromercuribenzoate at three different pH-values (pH 5,0; 6,5; 7,0; 8,0 and 6,5; 7,0; 8,0 respectively). 3. A reduction of enzymatic activity of 20% was found after incubation at 37°C for two hours.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 168 (1976), S. 129-141 
    ISSN: 1433-8580
    Keywords: Histomechanical properties ; pig aorta ; tensile tests ; Gewebsmechanik ; Schweineaorta ; Festigkeitstest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In einer Materialprüfmaschine wurde die frisch nach der Schlachtung freipräparierte Aorta ascendens von 47 weiblichen Schweinen der Dt. Landrasse aus einer Mastprüfungsanstalt an drei verschiedenen Gefäßwandlokalisationen (Stanzung) auf Reißkraft, Zugfestigkeit, Modul und Reißdehnung geprüft. Außerdem wurde der Elastingehalt ermittelt. Geringfügige Alters- und Gewichtskorrelationen bestanden und waren anhand der Regressionen zu berücksichtigen. Der mittlere Elastingehalt der Aorta ascendens nahm mit dem Alter signifikant ab, war aber mit den biomechanischen Eigenschaften der drei Einzelproben nicht gesichert korreliert. Reißkraft, Zugfestigkeit und Modul waren beim herznah entnommenen Gewebsstück I größer als bei der herzferneren Probe II, beide zeigten jedoch als quer zum Gefäßverlauf gewonnene Proben eine hochsignifikant stärkere Belastbarkeit als das längs zum Aortenverlauf herausgestanzte Wandstück III. Bei den Proben I und II bestand eine negative Korrelation zwischen Wanddicke und Zugfestigkeit. Ein Einfrieren der Proben für eine Woche bei -18°C hatte eine Schrumpfung und gesicherte Erhöhung der Reißkraft und Zugfestigkeit zur Folge. Die Bedeutung dieser Befunde für die vergleichende Angiologie wird diskutiert.
    Notes: Summary In a machine for tensile tests the ultimate strength, stress and strain of the aorta ascendens of 47 female pigs (German landrace) at three different regions of the vessel wall were determined. The animals were fattened under identical conditions in a progeny testing station and slaughtered at the same living weight (102 ± 2 kg). Weak regressions of body weight and age on parameters measured were nevertheless accounted for. The average elastin content of the aorta ascendens diminished with advancing age but was not significantly correlated to biomechanical properties of the three single samples. Maximum load, stress and modulus of vessel wall segment I (stamped out nearer to the heart) was greater than in sample II. These circumferential segments however exhibited highly stronger biomechanical resistance than sample III, which was stamped longitudinally. In samples I and II there was a negative correlation between thickness of the wall and ultimate tensile stress (N/mm2). Freezing of the material prior to test at -18° C for one week resulted in a significant rise in ultimate tensile strength and stress. The meaning of these findings for comparative angiology is discussed.
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  • 6
    ISSN: 1433-8580
    Keywords: Maltose ; perfused rat liver ; isolated hepatocytes ; glucose production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The conversion of14C-maltose into glucose, lactate and14 CO2 was studied in perfused livers from fed and fasted rats and in isolated hepatocytes. Maximal glucose production was 30 mM x g−1 x h−1; half-maximal rates were found with 3 mM maltose. About 0.01 % of the radioactivity infused was recovered as14CO2. The addition of maltose had no effect on rates of oxygen consumption, lactate production or ketogenesis. The data suggest that maltose did not serve as a major substrate for biosynthetic or energy producing processes under the conditions of the perfused rat liver.
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  • 7
    ISSN: 1433-8580
    Keywords: Rat ; liver damage ; thoracic duct ; thermocoagulation ; lymphedema ; 3H-thymidine ; autoradiography ; electron microscopy ; Ductus-thoracicus-Blockade ; Rattenleber ; 3H-Thymidin ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 90 männlichen und weiblichen, weißen Sprague Dawley Ratten wurden autoradiographische Untersuchungen mit3H-Thymidin nach experimenteller Blockade des Ductus thoracicus unternommen. Dabei zeigte sich im akuten Versuch kein nennenswerter Einfluß der intrahepatischen Lymphstase auf den DNS-Einbau in die Kerne der Hepatozyten bzw. Sternzellen. Bei den Langzeittieren (20–360 Tage) lagen die Markierungsindices der Hepatozyten geringfügig über denjenigen gleich alter, gesunder Kontrolltiere. Bei 14 männlichen und weiblichen, weißen Sprague Dawley Ratten führten wir zusätzlich elektronenmikroskopische Untersuchungen in der Leber durch. Dabei fanden sich im akuten Versuch ein intra- und extra-zelluläres Ödem sowie Schädigungen läppchenperipherer Hepatozyten. Nach 12–15 Tagen haben sich diese Veränderungen weitgehend zurückgebildet. Somit scheint eine intrahepatische Lymphstase keinen nachhaltigen Einfluß auf das Regenerationsverhalten der Leberzellen auszuüben.
    Notes: Summary Autoradiographic studies with3H-thymidine were done in 90 male and female white Sprague Dawley rats following thermocoagulation of the thoracic duct at the base of the neck. In the acute stages of these experiments we were unable to find any significant influence of a lymphedema on the hepatocytes and Kupffer cells. In the longterm experiments the labelling indices of the hepatocytes were slightly above those of healthy controls of the same age. In another 14 male and female white Sprague Dawley rats we did electron microscopical investigations of the liver. In the acute phase of the experiment we found an intra- and extrahepatic edema as well as damages of the hepatocytes at the periphery of the liver acini. After 12–15 days these findings have regressed. It seems therefore that an intrahepatic lymphedema does not influence the regenerative capacity of the liver to a marked extend.
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  • 8
    ISSN: 1433-8580
    Keywords: Initial phase of neurogenic pulmonary edema ; Perfusion fixation ; HRP ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.
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  • 9
    ISSN: 1433-8580
    Keywords: Galactose ; Infusion ; Galactose-1-phosphate ; Erythrocytes ; Healthy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Galactose was infused into healthy male volunteers at rates from 0.3 to 0.75 g/kg body weight per hour over a 6 hr period. During this time galactose-1-phosphate concentrations in the erythrocytes were measured by an enzymatic method. Galactose in serum was also determined. Depending upon the infusion rate, there was a different rise of galactose-1-phosphate concentration in the red blood cells, the highest values not exceeding 2 mg/100 ml. The results show that galactose-1-phosphate may accumulate also in erythrocytes of healthy men following the parenteral administration of large amounts of galactose. The painful side effects which some subjects complained of may be due to the intracellular accumulation of galactose-1-phosphate.
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  • 10
    ISSN: 1433-8580
    Keywords: Microcrystalline glucocorticoids ; Phagocytosis in fibroblasts ; Cell-metabolism ; Cell growth ; Mikrokristalline Glucocorticoide ; Phagocytose in Fibroblasten ; Zellstoffwechsel ; Zellwachstum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Mikrokristallines Glucocorticoid (9α-Fluor-16α, 17α-isopropyliden-dioxyprednisolon) wurde Fibroblastenkulturen zur Phagocytose angeboten. Versuchskulturen wurden mit dem Medium nach FIDP-Phagocytose sowie mit glucocorticoidhaltigem zellfreien Nährmedium über 6 Wochen beschickt. Die Versuchsergebnisse zeigen: Mikrokristallines Glucocorticoid wird von Phagocyten aufgenommen. Es verursacht in den Fibroblasten den typischen Glucocorticoidstoffwechsel mit Bremsung aller gemessenen Parameter: Sauerstoffverbrauch, Glucoseverbrauch, Milchsäure- und Brenztraubensäureentstehung, Zellwachstum und Mitoserate. Auch die typischen morphologischen Veränderungen werden ausgelöst. Glucocorticoid penetriert durch die Zellmembran in das Umgebungsmedium. Dieses Medium bewirkt an Versuchskulturen die gleichen typischen Stoffwechsel- wie morphologischen Veränderungen. Diese Veränderungen lassen für mikrokristallines Glucocorticoid die Deutung zu, daß dieses phagocytiert wird. Das intracellulär in Lösung gehende Glucocorticoid ruft an diesen Zellen typische Glucocorticoidwirkungen hervor. Genügend Substanz gelangt durch die Zellmembran in die Extracellulärflüssigkeit, um von dort aus systemische Wirkungen zu ermöglichen.
    Notes: Summary Microcrystalline glucocorticoid (9α-fluor-16α, 17α-isopropylidene-dioxyprednisolon) has been offered to fibroblast cultures for phagocytosis. Test cultures have been supplied with the medium after FIDP-phagocytosis as well as with cell-free nutrient medium containing glucocorticoid for 6 weeks. Test results show: microcrystalline glucocorticoid is taken up via phagocytes. It causes within the fibroblasts typical glucocorticoid metabolism with inhibition of all parameters measured: oxygen-consumption, glucose-consumption, formation of lactic and pyruvic acids, cell-growth and mitosis rate. Also the typical morphological changes are provoked. Glucocorticoid penetrates through the cell-lining into the environmental medium. This medium produces on test cultures the same typical metabolic and morphological alterations. These alterations allow the interpretation as regards microcrystalline glucocorticoid that it is phagocytable. Glucocorticoid dissolving intracellularly provokes in these cells typical glucocorticoid effects. There is sufficient substance left to pass through the cell-lining into the extracellular fluid to allow systemic effects from there.
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