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At least 109 records · Page 6Linked to original sources

Blood changes in water deprived rats.

To study the variations of blood constituents during water deprivation, rats were deprived of water from six to twelve days. Control and rehydrated animals were also included in the study. A significant increase was observed in sodium, chloride and hematocrit throughout the experiment. Calcium, bicarbonate and PCO2 increased at 10-11 days of treatment. Potassium, inorganic phosphorus, pH, base excess and blood buffer capacity did not change in the course of the experiment. Rehydrated animals recovered to control levels in all the studied components, except for pH and base excess, which increased somewhat. Plasma volume changes could explain only partially electrolyte variation. The "dehydration reaction" is considered to be the main mechanism responsible for these changes. Unchanged hematocrit levels in water deprived animals suggest that after 6 days of water deprivation there is no further loss of plasma water. Bicarbonate and PCO2 changes showed a good relationship and may account for unchanged pH and base excess values.

Acid-Base Equilibrium↗

Fetal acid-base balance. I. Interdependence of maternal and fetal PCO2 and bicarbonate concentration.

This paper presents the results of measurements of the acid-base and gaseous status of maternal and fetal capillary blood at the time of amniotomy, before the onset of labor. The correlation coefficient between maternal and fetal bicarbonate concentration is 0.6, and that between maternal and fetal PCO2 is 0.31. From the results obtained, as well as from a survey of other work in the field, it is proposed that the diffusion of carbon dioxide across the placenta could not explain some of the findings and that bicarbonate concentrations equilibrate across the placenta.

Acid-Base Equilibrium↗

[Computer experience and further developments in the respiratory function laboratory (author's transl)].

Reported is on satisfactory results obtained with a small-size computer consisting of punching and scanning device, as well as plain writing machine in the respiratory function laboratory. Developed in on- as well as off-line processing by an own technical staff, a diagnostic and teaching program was established for all respiratory function routine methods with the advantages of a large number of cases examined, elimination of sources of error, considerable supply of data and information, automatic documentation and filing, plain writing, interpretation and evaluation of findings. In continuation of such works also the blood gas analysis has been included. These values as the total of disturbances of the pathophysiological acid-base status are considered and interpreted. Clinical correction is forced in this man-machine dialogue by automatic stops of the whole machinery before going on. Subsequently and in addition are computer alveolar-arterial oxygen pressure gradient, venous shunt and oxygen saturation and expressed utilizing the capacity of the small-size computer. Further developments in the respiratory function diagnostic- and teaching program for small-size computers--not too expensive in the building block principle - are intended.

Acid-Base Equilibrium↗

[Effect of 1,4-benzodiazepine derivatives on the toxic action of oxygen under increased pressure].

The 1,4-benzodiazepine derivatives (diazepam, nitrazepm, lorazepam, clonazepam and two newly synthetized compounds of this series) increase the resistance of albino rats and rabbits to the toxic effect of oxygen under high pressure (7 and 5.5 atm respectively). The compounds under study are apt to avert over a long period the development of metabolic acidosis which appears following the action of high-pressure oxygen on the body.

Acid-Base Equilibrium↗

[Ionization of the acid-base groups of polyene antibiotics in aqueous solutions].

The acid-base characteristics of polyenic antibiotics, such as nystatin, mycoheptin and levorin in aqueous solutions were studied. A special procedure provided the use of potentiometric titration for investigation of ionization of the groups of vater-insoluble substances. The ionization constants of the carboxylic and amine groups of the antibiotics at several temperatures were determined. It was found that ionization of the acid group did not practically depend on the temperature. At the same time the heat effect of the amine group ionization was significant and amounted to about 10 kcal/mole. Thermodynamic analysis of the ionization process of the polyenic antibiotics in aqueous solutions was performed. Integral components defining the process energetics were calculated.

Acid-Base Equilibrium↗

Acid-base measurements of arterial, venous and capillary blood in the dog.

A method of arterial blood sampling acceptable for clinical purposes for acid-base estimations in dogs is described. A comparison of acid-base variables from fourteen canine arterial, venous and capillary blood samples revealed in most cases that venous and capillary blood samples showed unsatisfactory agreement with corresponding arterial blood samples. Two commercial automatic pH and blood-gas analysing systems are compared.

Acid-Base Equilibrium↗

Acid-base parameters in the dehydrated camel.

The effect of prolonged (10 days) dehydration on acid-base parameters of camel blood was examined. The pH and PCO2 levels rose significantly in the course of dehydration. This state was comparable with compensated non-respiratory alkalosis found in other animals. The plasma sodium, and magnesium levels rose significantly also. The plasma oxygen and calcium levels declined significantly. There were no significant changes in potassium and phosphate levels. It is concluded that the changes found in acid-base status following dehydration are further evidence of water preservation mechanisms in the dehydrated camel.

Acid-Base Equilibrium↗

[Changes in partial pressures of gases and of pH in the arterial blood of hypocapnic and hypercapnic subjects subjected to oxygen therapy].

The behaviour of partial tensions of respiratory gases and pH in the arterial blood was evaluated in anoxiaemic and hypercapnic (1st group) and hypo-eucapnic (IInd group) subjects undergoing oxygen therapy. The following phenomena were observed: 1) normalization in paO2 values in both groups; 2) statistically significant diminution in paCO2, especially as regards hypercapnic subjects; 3) statistically significant diminution in blood pH; 4) statistically significant diminution in bicarbonates. In the light of these findings, it is considered that other variables, such as the electrolytes, might play an important role in pH diminution during oxygen therapy and that further research should be carried out to look into the possibility.

Acid-Base Equilibrium↗

H in cortical peritubular capillaries of rat kidney.

The pH of peritubular capillaries was measured by means of antimony microelectrodes, during their perfusion with mammalian Ringer's solutions at different pH, in control and acetazolamide infused rats. In capillaries perfused with a solution more acid than blood, significant alkalinization was observed at increasing distances from the point of perfusion, while during perfusions with more alkaline solutions, acidification was observed. Plotting the pH change observed per micrometer of distance from the perfusion point against the pH of the perfusing solution, the pH in equilibrium with tubular cells was interpolated. A value of 7.51 +/- 0.01 was found for control rats, significantly higher than the mean arterial blood pH of this group, of 7.39. In acetazolamide infused rats an equilibrium pH of 7.44 +/- 0.02 was found, still higher than the blood pH of 7.34. The slope of these lines was significantly greater in control than in acetazolamide treated rats. This slope was shown to evaluate permeability to the ions responsible for acid-base balance. The present data suggest that peritubular alkalinization is reduced after carbonic anhydrase inhibition due to decreased peritubular permeability to the involved ions, which represents a further site of action of these inhibitors.

Acetazolamide↗