1975
Schmoldt A, Benthe HF, Haberland G.
Digitoxin metabolism by rat liver microsomes. Biochem Pharmacol. 1975;24(17):1639-41.
Scherberger RR, Kaess H, Brückner S.
[Studies on the action of an anticholinergic agent in combination with a tranquilizer on gastric juice secretion in man]. Arzneimittelforschung. 1975;25(9):1460-3.
AbstractA double-blind study with intra-individual comparisons was carried out to investigate the effects of 15 mg of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH-tropanium bromide(+/-)-tropate (Sch 1000), 15 mg Sch 1000 + 10 mg oxazepam, 10 mg oxazepam and placebo with oral administration in randomized sequence on gastric juice volume, amount of acid, concentration and pH values in 12 healthy volunteers. The secretion parameters were measured during a 1-h basal period and a 2-h stimulation period. The gastric juice was obtained in 15 min portions via stomach tube. Stimulation was effected by 1 mug/kg/h pentagastrin via drip infusion. The Friedman test was used for the comparative statistical evaluation, and individual comparisons were carried out by means of the Wilcoxon test (pair-differences rank). The results show that Sch 1000 and Sch 1000 + oxazepam were equal in effect on basal and stimulated secretion volume. As compared with placebo, it was not possible to establish an effect on secretion volume for oxazepam alone. Sch 1000 and Sch 1000 + oxazepam were found to be equipotent in reducing the amount of basal acid, while oxazepam reduced this quantity only during the first 30 min of basal secretion. None of the three active preparations was capable of inhibiting the stimulated acid, although both Sch 1000 preparations produced a clear trend towards lowered mean values. During the basal secretion period, all three test preparations had an inhibiting action on acid concentration, but none of them had a significant effect during the stimulation period. The pH value was savely increased only by Sch 1000 and Sch 1000 + oxazepam, and this even only during the basal period. The results are discussed.
Chow YW, Pietranico R, Mukerji A.
Studies of oxygen binding energy to hemoglobin molecule. Biochem Biophys Res Commun. 1975;66(4):1424-31.
Nieto M, Muñoz E, Carreira J, Andreu JM.
Conformational and molecular responses to pH variation of the purified membrane adenosine triphosphatase of Micrococcus lysodeikticus. Biochim Biophys Acta. 1975;413(3):394-414.
AbstractA preparation of ATPase from the membranes of Micrococcus lysodeikticus, solubilized and more than 95% pure, showed two main bands in analytical polyacrylamide gel electrophoresis. They did not correspond to isoenzymes because one band could be converted into the other by exposure to a mildly alkaline pH value. The conversion was paralleled by changes in molecular weight, circular dichroism and catalytic properties. Denaturation by pH at 25 degrees C was followed by means of circular dichroism, ultracentrifugation and polyacrylamide gel electrophoresis. A large conformational transition took place in the acid range with midpoints at about pH = 3.6 (I = 10(-4) M), 4.3 (I = 0.03 M) and 5.3 (I = 0.1 M). The transition was irreversible. Strong aggregation of the protein occurred in this range of pH. The final product was largely random coil, but even at pH 1.5 dissociation into individual subunits was not complete. However, partial dissociation took place at pH 5 (I = 0.028 M). At this pH value the enzyme was inactive, but 20-30% of the activity could be recovered when the pH was returned to 7.5. In the alkaline region the midpoint of the transition occurred near pH = 11 (I = 0.028 M). The pK of most of the tyrosine residues of the protein was about 10.9. The unfolding was irreversible and the protein was soon converted into peptide species with molecular weights lower than those determined for the subunits by gel electrophoresis in the presence of sodium dodecyl sulphate. Conventional proteolysis did not account for the transformation.
Mehta RJ.
Pyridine nucleotide-linked oxidation of methanol in methanol-assimilating yeasts. J Bacteriol. 1975;124(3):1165-7.
AbstractAn alcohol dehydrogenase linked to nicotinamide adenine dinucleotide and requiring glutathione has been isolated and partially purified from two methanol-assimilating yeasts. It differs from previously described methanol-oxidizing enzymes in pH optima, electron acceptor specificity, substrate specificity, inhibition pattern, and stability.
Matusik E, Gibson TP.
Fluorometric assay for N-acetylprocainamide. Clin Chem. 1975;21(13):1899-902.
AbstractWe describe a simple, rapid fluorometric assay for separate quantitative analysis of procainamide and N-acetylprocainamide in mixtures. The effective lenear range (fluorescence vs. concentration) in serum is 0.1 to 10.0 mg/liter, regardless of the ratio (by weight) of the two drugs from 1:10 to 10:1. Analytical recoveries by the extraction method used were 100.0 +/- 3.0% and 98.0 +/- 4.0%, respectively. For determination of either compound, the maximum coefficient of variation was 10%.
Van Gorkom HJ, Pulles MP, Wessels JS.
Light-induced changes of absorbance and electron spin resonance in small photosystem II particles. Biochim Biophys Acta. 1975;408(3):331-9.
AbstractPhotosystem II reaction center components have been studied in small system II particles prepared with digitonin. Upon illumination the reduction of the primary acceptor was indicated by absorbance changes due to the reduction of a plastoquinone to the semiquinone anion and by a small blue shifts of absorption bands near 545 nm (C550) and 685 nm. The semiquinone to chlorophyll ratio was between 1/20 and 1/70 in various preparations. The terminal electron donor in this reaction did not cause large absorbance changes but its oxidized form was revealed by a hitherto unknown electron spin resonance (ESR) signal, which had some properties of the well-known signal II but a linewidth and g-value much nearer to those of signal I. Upon darkening absorbance and ESR changes decayed together in a cyclic or back reaction which was stimulated by 3-(3,4 dichlorophenyl)-1,1-dimethylurea. The donor could be oxidized by ferricyanide in the dark. Illumination in the presence of ferricyanide induced absorbance and ESR changes, rapidly reversed upon darkening, which may be ascribed to the oxidation of a chlorophyll a dimer, possibly the primary electron donor of photosystem II. In addition an ESR signal with 15 to 20 gauss linewidth and a slower dark decay was observed, which may have been caused by a secondary donor.
Cole R, Proulx P.
Phospholipase D activity of gram-negative bacteria. J Bacteriol. 1975;124(3):1148-52.
AbstractA phospholipase hydrolyzing cardiolipin to phosphatidic acid and phosphatidyl glycerol was characterized in gram-negative bacteria but was absent in preparations of gram-positive bacteria, Saccharomyces cerevisiae, and rat liver mitochondria. In cell-free extracts of Escherichia coli, Salmonella typhimurium, Proteus vulgaris, and Pseudomonase aeruginosa, this cardiolipin-hydrolyzing enzyme had similar pH and Mg2+ requirements and displayed a specificity which excluded phosphatidyl glycerol and phosphatidyl ethanolamine as substrates.
Kienlen J, Arnefaux J, Brabet L, Dupont MH, Grolleau D, Guilhot R, Laurent S, Sube J, Vernette M, Wintrebert P, et al. [Anesthesia in reoperations in abdominal surgery]. Ann Anesthesiol Fr. 1975;16(4):241-51.
AbstractFifty one patients from different surgical units, hence anesthetized by different anaesthesists, underwent reinterventions in abdominal surgery. The indications for the first intervention essentially involved the supra-mesocolic region of the abdomen (62 out of 100 cases). The operative risk during the first intervention was on the average 18 pour cent. The protocol of the first anaesthesia which was known in 42 cases, was of the narco-ataralgestic type. The date of the return to the operation table varied from 1 to 60 days. The state of the patients was in general catastrophic (organic renal failure, acute respiratory failure). Here again the anaesthesia was of the narco-ataralgesic type but the choice of drugs varied depending on the patients' state. However non significant difference was noted in the average hourly drug consumption between the two interventions. Apart from one circulatory arrest during induction, in one patient with hemorrhagic shock, no death was attributable to the anesthetic technique. The authors, using these findings, attempt to pick out a practical line of behaviour.
Konovalov SA, Vorotilo SP, Maximov VI.
[Study of the yeast dissolving enzymic complex by isoelectric focusing]. Prikl Biokhim Mikrobiol. 1975;11(2):226-9.
AbstractBy isoelectric focussing the lyzing complex produced by Actinomyces griseinus-11 has been fractionated. The sole neutral protease which is active at pH 7.0 does not participate in lysis induced by other enzymes. The lyzing activity of this complex is associated with the carbohydrase enzymes that are at least three in number. Various carbohydrases may exert a synergistic effect upon their combined action on the protein-vitamin concentrate.