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  • 1
    ISSN: 1432-1440
    Keywords: Transcutaneous $$P_{O_2 }$$ ; Transcutaneous $$P_{CO_2 }$$ ; in vivo determination of the local capillary Hb concentration ; Bloodless Determination of the Arterial $$P_{O_2 }$$ and $$P_{CO_2 }$$ , Bloodless Determination of the Acid/Base Status ; Transcutane $$P_{O_2 }$$ ; transcutaner $$P_{CO_2 }$$ ; in vivo-Bestimmung der lokalen capillären Hämoglobinkonzentration ; unblutige Erfassung der Blutgase ; unblutige Erfassung des Säure-Basen-Status
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Arterielle Blutgaswerte lassen sich transcutan erfassen, wenn die Perfusionseffizienz der Haut so hoch ist, da\ kleine Änderungen der Durchblutung den gemessenen $$P_{O_2 }$$ - und $$P_{CO_2 }$$ -Wert nicht verändern. Dies läßt sich mit speziell konstruierten, thermostatisierten und geheizten $$P_{O_2 }$$ - und $$P_{CO_2 }$$ -Elektroden erreichen. Die zur Temperatur-regelung notwendige Heizleistung ist ein Maß für die Perfusion, die gleichzeitige Veränderung des $$P_{O_2 }$$ oder $$P_{CO_2 }$$ ein Maß für die Effizienz. Ist der arterielle $$P_{O_2 }$$ und $$P_{CO_2 }$$ bekannt, so läßt sich der Säure-Basen-Status nach der bekannten Methode der Blutnomographie bestimmen.
    Notes: Summary Arterial blood gas values can be monitored transcutaneously, if the perfusion efficiency of the skin is so high that small changes in blood flow do not change the measured $$P_{O_2 }$$ and $$P_{CO_2 }$$ values. This is brought about by specially constructed $$P_{O_2 }$$ and $$P_{CO_2 }$$ electrodes which are heated and thermostated. The power necessary to regulate the temperatures of the electrode serves as an index of the perfusion, the simultaneous change of the transcutaneous $$P_{O_2 }$$ and $$P_{CO_2 }$$ as an index of efficiency. Knowing the arterial $$P_{O_2 }$$ and $$P_{CO_2 }$$ , the acid/base status can be determined by applying the well known methods of blood nomography.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 216 (1977), S. 519-519 
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 221 (1978), S. 269-284 
    ISSN: 1434-4726
    Keywords: Intracochlear pO2 ; Inner ear microcirculation ; Sympathectomy ; Exposure to loud sounds ; Microcoaxial needle electrodes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Oxygen partial pressure (pO2) profiles and microcirculatory parameters were recorded in vivo under standardized conditions in the three scalae of the cat's cochlea after unilateral excision of the upper cervical sympathetic nerve. Experiments were performed both under rest conditions and during exposure to loud sounds. pO2 and pH2 were polarographically measured using microcoaxial needle electrodes with sputtered reference elements according to Baumgärtl and Lübbers (1975). The tip diameter of the complete probe was 0.3–0.7 μm. The oxygen pressure field of the three scalae of the basal winding was recorded through the round window membrane during continuous advance of the needle (150 μm/min). Temporal pO2 changes as well as microcirculatory parameters were measured in the scala media after the electrode was fixed in position. Starting out from the air values at the surface of the round window membrane, pO2 decreased continuously from more than 100 Torr during insertion towards the basilar membrane, where it averaged 25 Torr. When the needle had penetrated the basilar membrane and entered the endolymphic space, an increased pO2 of 35–40 Torr was recorded. After penetrating Reissner's membrane, a slightly decreased pO2 was measured in the scala vestib. Aside from the oxygen reaching the cochlea through the round window, the capillaries of the round window membrane were found to contribute to the oxygen saturation of the perilymph near the window. Under rest condition, unilateral upper cervical sympathectomy did not noticeably influence the oxygen pressure field in the three cochlear scalae. After exposure to loud sounds, however, endolymphic pO2 decreased less and recovered quicker on the sympathectomized side than on the intact one. Ventilation of the animals with pure oxygen or gas mixtures of high CO2-O2 concentrations increased the pO2 level within 1 min. The increase was more pronounced in the endolymphic space than in the other cochlear scalae and also the pO2 decrease in the scala media was particularly distinct in the cat. Under exposure to loud sounds the influence of the sympathetic nerve on the intracochlear pO2 was found to depend on the aortic blood pressure. The advantageous effect of sympathectomy was particularly visible at a low aortic pressure but less distinct at a higher one. In some cases, a long-lasting pO2 decrease was noticed in the endolymphic space even after short (1–2 s) exposure to noise. The hydrogen exchange rate recorded in the endolymphic space after exposure to loud sounds (noise of 115 dB) using the hydrogen clearance method was distinctly delayed and, consequently, the capillary blood flow was diminished. Unilateral acute upper cervical sympathectomy favorably influenced the peripheral circulation during exposure to loud sounds by increasing the blood flow (reduced half life period). The experiments showed that unilateral acute upper cervical sympathectomy did not considerably influence the endolymphic pO2 under rest condition, whereas an advantageous effect on the endocochlear pO2 and blood flow was noticed under exposure to loud sounds. Moreover, there was indication of a correlation between sympathetic effect and mean aortal blood pressure.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1435-2451
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um bei der kurzen Ischämietoleranz der Leber während der Isolierung, Konservierung und Transplantation eine primäre Schädigung durch Hypoxie mit nicht Hb-haltigen Lösungen zu vermeiden, wird ein eigenes Perfusionsverfahren angegeben. Durch vergleichende Messungen des Gewebs-PO2 der Leber, der Sauerstoffspannung im zu- und abfließenden Medium sowie des Austrittes von Enzymen in das Perfusionsmedium wird gezeigt, daß innerhalb von 15–20 min eine Hypothermie von 18–20°C erreicht sein muß, um anoxische irreversible Schädigungen zu vermeiden. Ausschlaggebend ist, daß bei der Schweine-oder Hundeleberperfusion diese Hypothermiestufe während des Auswaschens, also noch mit Hb-haltigem Medium, bereits im Spenderorganismus erreicht wird, denn erst dann kann auf Hb-freies Medium umgeschaltet werden. Unter gleichzeitiger pulsatorischer (A. hepatica) und kontinuierlicher (Pfortader) Leberdurchströmung in einer eigens dafür konstruierten Perfusionskammer und Zusatz von Coenzym A, Glucose, DPNH, Pyruvat und Na-Capronat zu den osmotischen und onkotischen Anteilen des Perfusionsmediums gelingt es, die bisher auf 4 Std befristete Perfusionszeit auf 8 Std zu verlängern und eine Sauerstoffspannung des Gewebes zwischen 50–540 mm Hg zu garantieren, die eine Hypoxie sicher ausschließen läßt.
    Notes: Summary To avoid during its isolation, preservation and transplantation primary damage of the liver—which has only a short ischaemia tolerance—due to hypoxia with solutions that contain no haemoglobin, our own perfusion procedure is described. Comparative measurements of the tissuePO2 of the liver, the partial pressure of oxygen in the in and out-flowing media, as well as the loss of enzymes in the perfusion media demonstrate that a hypothermia of 18–20°C has to be reached within 15–20 min to avoid anoxic irreversible damage. The decisive factor here is that in the liver perfusions of pigs and dogs this stage of hypothermia was reached already in the “washing out stage”, that is while an Hb containing medium was still present, in the donors body. Only then was the switch-over to an Hb free medium made. By continuous (portal vein) and simultaneous pulsatile (hepatic artery) liver perfusion in a perfusion chamber specially designed for this purpose, and by adding co-enzyme A, glucose, DPNH, pyruvate and sodium capronate to the osmotic and oncotic portions of the perfusion medium, it became possible to extend the perfusion period, which had been restricted to 4 hours till now, to eight hours and to guarantee a partial pressure of oxygen in the tissues of between 50–540 mm Hg, which positively excludes hypoxia.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 37 (1981), S. 206-208 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new probe (tip diameter=700 μm) consisting of a micro-light guide and a silver wire electrode was constructed to measure pyridine nucleotide fluorescence and field potentials from nerve tissues. Good kinetic correlations were found between the changes in field potentials and tissue pyridine nucleotide fluorescence caused by stoppage or by resumption of superfusion.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 27 (1971), S. 394-395 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of local pO2 measurements with Pt-needle electrodes an oxygen impermeable zone in the arteria carotis of the cat has been found.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-2013
    Keywords: Redox state of cytochromes ; Blood-free brain perfusion ; Reflection photometry ; Nonlinear multicomponent analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract After developing a blood-free perfused preparation of the guinea pig brain a nonlinear multicomponent analysis (NLMCA) of the reflection spectra of the brain surface was worked out by which the redox state of cytochromeaa 3;c andb could be evaluated quantitatively and almost continuously. The NLMCA allowed to simulate the tissue reflection spectra in such a way that only a small statistical error remained between the recorded and the computed spectra. Using redox states of cytochromeaa 3 andc as an intracellular oxygen probe it was found that in order to supply the guinea brain with sufficient oxygen by a saline medium equilibrated with 95% oxygen and 5% CO2 the temperature had to be reduced to 18–20°C. At this temperature cytochromeaa 3 was 95% oxidized.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 243 (1962), S. 312-312 
    ISSN: 1432-1912
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Archives of gynecology and obstetrics 207 (1969), S. 443-451 
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Auf der arterialisierten Kopfhaut von 2–6 Tage alten Kindern wurde unblutig — und zur Kontrolle blutig — der Sauerstoffdruck mit einer neuen Meßanordnung bestimmt. Es zeigte sich, daß repräsentative und vergleichbare Messungen auf der Kopfhaut möglich sind. Das eigentliche Problem besteht in der Fixierung der Elektrode auf der Kopfhaut. Auf der arterialisierten Kopfhaut wurden 67,7±7,1 mm Hg gemessen, die entsprechenden Blutwerte betrugen 67,8±8,4 mm Hg. In einer zweiten Serie wurde der Gewebsdruck auf der nichtarterialisierten Kopfhaut mit 36,8±9,4 mm Hg bestimmt. Ein Vergleich der Ergebnisse mit den Werten der Literatur ergibt eine weitgehende Übereinstimmung.
    Notes: Summary On the arterialized scalps of 2 to 6-days-old newborns the oxygen pressure was determined by an unbloody and for control bloody method. A new device was used. The studies revealed that representative and comparable measurements on the scalp can be obtained. Attaching the electrode to the scalp remains a crucial problem. On the arterialized scalp a pressure of 67.7±7.1 mm Hg was determined. The respective values using the bloody method were found to be 67.8±8.4 mm Hg. In another series the tissue pressure on the non-arterialized scalp was measured. The reading was 36.8±9.4 mm Hg. A comparison of these values obtained by above mentioned methods with those reported by the literature is showing a remarkable concordance.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 57 (1970), S. 42-42 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
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