The oxygen affinity of concentrated human hemoglobin solutions and human blood

The log P50 of normal human blood at 37 degrees C, PCO2 = 0, 21, 42, AND 57 MM Hg in the absence and in the presence of 2,3-DPG and ATP, has been determined in the pH range 7.0 to 7.6. Similar data have been obtained for human hemoglobin isotonic solutions at different protein concentrations in the presence of various amounts of each of the cofactors which are known to affect hemoglobin oxygen affinity in blood. It has been found that the addition of KC1, organic phosphates, magnesium ions, and CO2 confers to a 32% human hemoglobin solution the same oxygen affinity (over the entire physiological pH range) of whole blood. Thus there is no room for significant effects caused by some other unidentified molecules or ions.

Studies on the mechanism of metabolic stimulation in polymorphonuclear leukocytes during phagocytosis. Activators and inhibitors of the granule bound NADPH oxidase

The effects of several known inhibitors and activators of peroxidase-catalyzed reactions have been studied on the NADPH oxidase activity of granules isolated from polymorphonuclear leukocytes at rest or during phagocytosis. Redogenic substances, such as ascorbate or hydroquinone, and superoxide dismutase, which are known to inhibit peroxidase-catalyzed reactions, also inhibited the NADPH oxidase activity of granules. Oxidogenic substances, such as guaiacol or resorcinol, and manganese, which are known to stimulate peroxidase-catalyzed reactions, also activated the NADPH oxidase activity of granules. Cyanide, an inhibitor of peroxidase-catalyzed reactions, inhibited the NADPH oxidase activity of granules isolated from resting leukocytes but only slightly affected that of granules isolated from phagocytosing cells, as previously reported. A list of the properties of the NADPH oxidase activity of granules and of peroxidase oxidase activity is given. The arguments in favor of and those against a possible identity of the two activities are discussed.

Metabolic perturbation of the inflammatory cells

An activation of the oxidative metabolism of phagocytes is a regular concomitant of phagocytosis as well as of other functions of these cells such as exocytosis, chemotactic locomotion, and immune-adherence. Several other substances, some of which may be found in the inflammatory site, are also able to stimulate the oxidative metabolism of phagocytes, for example phospholipases, antileucocyte antibodies, endotoxins, fatty acids, surfactants and fragments of complement. This paper deals with, (1) the molecular events occurring within the plasma membrane that trigger the stimulation of the oxidative metabolism. An experimental model is presented that involves redistribution of ions across the plasma membrane of leucocytes as the trigger of the stimulated respiration and exocytosis; (2) the intracellular localization of the enzymatic system that is the effector of the metabolic response. A scheme is proposed for the mechanism of this enzymatic system which accounts for the production of highly reactive compounds such as hydrogen peroxide, superoxide anion radical and hydroxyl radical during the metabolic activation of phagocytes.

[Peroperative resuscitation in abdominal reoperations]

Resuscitation of these patients during operation is the only the logical continuation of their preparation. The authors therefore take up the preceding points while emphasizing: - checking vascular filling, by central venous pressure and hourly diuresis; - the necessity for a supply of carbohydrates, which is even more indispensable when the subjects were submitted to parenteral hyperalimentation previously; - the advantages of performing arterial blood gases in order to check artificial ventilation.

[Experimental analysis of the interactions between heparin and a duodenal heparinoid]

It is shown that positive synergism exists between the clarifying, hypocholesterolaemising, hypolipidaemising and fibrinolytic effects of heparin sodium and a duodenal heparinoid. The results of pharmacokinetic and chemicophysical investigations are also presented.

[Experimental analysis of some cardiovascular effects of Verapamil]

In vivo and in vitro experiments showed that Verapamil dilates the coronaries, prevents coronary spasm, produces Ca++-antagonism, offers protection against myocardial necrosis, prevents arrhythmia, reduces pressure, increases the purinergic reactivity and produces inhibition of platelet aggregation. It was devoid of competitive-adrenolytic activity in the heart and vessels. A methoxy derivative of the drug (D-600) had a negative inotropic and chronotropic action and was more hypotensive than Verapamil.

Studies on the mechanism of metabolic stimulation in polymorphonuclear leucocytes during phagocytosis. I. Evidence for superoxide anion involvement in the oxidation of NADPH2

1. The oxidation of NADPH2 by leucocyte granules, as measured at acid pH in the presence of Mn-2+, was found to be inhibited by superoxide dismutase. 2. Omission of Mn-2+ markedly lowered the oxidase activity at acid pH, which was still inhibited by superoxide dismutase. 3. At alkaline pH the oxidase activity was lower than at acid pH. 4. During oxidation of NADPH2 by leucocyte granules, reduction of cytochrome c occurred which was partially inhibited by superoxide dismutase. 5. It was concluded that NADPH2 oxidation occurs through an enzymatic reaction and a nonenzymatic chain reaction. Superoxide anion (O-minus-2 and NADPH- free radical would be involved in the chain reaction. The differential sensitivity of NADPH2 oxidation to superoxide dismutase in different experimental conditions (see above 1, 2 and 3) was explained on the basis of changes in the properties of the chain reaction.