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Biomedical subjects

H Metzler

Publications and source records attributed to H Metzler.

80 records · Page 5Linked to original sources
PubMed1980

Oscillations of the NAD(P)H pool size and of the redox state of a cytochrome b during dark respiration of the blue-green alga, Anacystis nidulans.

Oscillations of the oxygen uptake rate of the blue-green alga (cyanobacterium) Anacystis nidulans were induced by light pulses. The pool size of NAD(P)H and the redox state of a cytochrome b showed oscillations of similar shape and frequency. Phase diagrams revealed that these three oscillations were presumably linked. The cytochrome b should be a part of the respiratory chain of this blue-green alga. The oscillations were inducible only in a limited physiological state of the alga.

Cyanobacteria↗
PubMed1980

[The importance of continuous intra-arterial PO2 measurement for evaluation of PO2 changes with drugs, positioning and hyperoxygenation (author's transl)].

In 26 adult patients arterial pO2 was measured continuously with intra-arterial pO2 electrodes over 24 hr after cardiac surgery. The effects of nitroglycerin, Thalamonal and change of body position were investigated. Hyperoxygenation with 100% O2 was tested. The following results were obtained: 1. pO2 and drugs: i.v. nitroglycerin and Thalamonal lead to a decrease in pO2, which occurred with a delay after the blood pressure fall. - 2 pO2 and body position: In the majority of patients with mitral stenosis and in one patient with acute myocardial infarction we found increased pO2 values with 40 degrees head up tilt as compared to supine position. - 3. Hyperoxygenation: The peak values of pO2 after a F1O2 of 1.0 were reached between 6-18 min, with a gradual fall afterwards. The relationship of measured pO2 values, cardiac disease and surgical procedures is discussed.

Adrenergic alpha-Antagonists↗
PubMed1979

[Treatment of intra- and postoperative cardiac tachyarrhythmias with the new calciumantagonist Ro 11-1781 (author's transl)].

30 patients with cardiac tachyarrhythmias were treated intra- and postoperatively with the new calciumantagonist Ro 11-1781. Atrial fibrillation, paroxysmal supraventricular tachycardia, supraventricular and ventricular extrasystoles and atrial tachycardia were the main indications. A good antiarrhythmic effect was noticed, provided that a dose of not less than 1 mg/kg was given. The mean fall of blood pressure was 4%, the maximal fall 15%.

Adult↗
PubMed1978

[Reactions in the brainactivity during increased carbondioxyde concentration (author's transl)].

A comparative study of two kinds of respiration (normal air and mixed with 4% CO2) was carried out in 8 healthy students. During the three experiments, each one lasting over 120 min, CO2 or air was inhaled using a mask. Blood samples were taken from the fingers, an average increase of pCO2 of 1.9 mm (p less than 0.01) and pO2 of 7.3 mm (p less than 0.01) was found during CO2-inhalation. The ECG and EEG were recorded and reaction times to tone stimuli in a foreperiod reaction time experiment were measured. During CO2-inhalation a clear reduction of the power in the alpha-band was found in frontal, central and occipital region in the order of 23% (p less than 0.05) and 12% (p less than 0.05) and 22% (p less than 0.01). The heart rate interval decreased significantly by 2.3% (p less than 0.05). No significant changes were found in CNV, reaction time and percentage event-related alpha-desynchronization.

Adult↗
PubMed1978

[Continuous mass-spectrometric measurement of CO2 while using a modified Mapleson D-(Bain-)system (author's transl)].

In 21 patients undergoing abdominal surgery a modified Mapleson D-(Bain-)system was used under controlled ventilation. An average endexpiratory CO2 of 40 mm Hg was measured at a flow of 70 ml/kg kontinuierlich registrierten endexspiratoritimes these values were stable. In some patients without evident metabolic disturbances we found the CO2 values at borderline or even pathologic. So an increased flow rate of 100 ml/kg is recommended.

Adult↗
PubMed1977

Distribution of excitation energy among photosystem I and photosystem II in red algae. I. Action spectra of light reactions I and II.

Action spectra of light reaction I and light reaction II from red algae (marine members of Florideae and Bangiales) were measured with 550 nm (light 2) or 699 nm light 1) background light, using a Teflon-covered platinum electrode for O2 measurement. Care was taken to ensure that maximum enhancement was reached by the background light. The action spectra of light reaction I, we found under these conditions, are very similar to the thallus absorption, whilst the action spectra of light reaction II show, besides strong bands of the phycobilins, only minor bands of chlorophyll a, which account for only 10-20% of the total chlorophyll. The spectra are discussed on the basis of two main types of models of energy distribution over both photosynthetic systems. If this distrubution is considered to be invariable (models 1a and b), one has to assume that almost exactly half of the total chlorphyll is not involved in the supply of the non-cyclic electron transport with excitation energy. This part, however, has to be thought of as incorporated in the thylakoid membrane in a similar manner to the chlorophyll in photosystem I. However, if one supposes an almost complete equilibration in the energy distribution over both systems as long as the primary absorption in photosystem II prevails (models 2a and b), there is no need for the assumption of such photosynthetically 'inactive' or less active chlorophyll. Some evidence is shown that strongly supports model 2.

Chlorophyll↗
PubMedDate not supplied

Influence of lipid infusion (0.4 g/kg/hr) and positive end expiratory pressure (8 cm H2O) on pulmonary function and hemodynamics in healthy anesthetized pigs.

Fat emulsions are used increasingly for parenteral nutrition in premature infants suffering from various disorders, including respiratory insufficiency necessitating artificial ventilation with positive end expiratory pressure (PEEP). Both PEEP and lipid infusions (LI) may alter pulmonary hemodynamics. The simultaneous effect of LI and PEEP were therefore investigated. Five adult anesthetized Göttinger minipigs were infused with a 20% LI at a high rate of 0.4 g/kg/hr for 30 min, followed by PEEP of 8 cm H2O for 15 min. Catheters were inserted into the upper vena cava, the pulmonary artery, the right and left atrium, and the aorta, and pressures recorded continuously. Ventilation volume, respiratory fractional gas concentrations of O2 and CO2 (mass spectrometer), and blood gases were measured. The following parameters were calculated: total peripheral resistance, pulmonary arteriolar resistance, right-to-left shunt (QS/QT) dead space ventilation (VD/VT) and effective compliance. Total peripheral resistance remained unchanged. Pulmonary arteriolar resistance increased significantly during PEEP, PEEP + LI, but not during LI alone. QS/QT increased significantly during LI and returned to normal when PEEP was applied. VD/VT and effective compliance did not change during LI. The increased right to left shunt, caused by LI, is reduced by means of PEEP, while the pulmonary arteriolar resistance increased with PEEP and LI.

Anesthesia, Inhalation↗