bluuebunny/crossref_metadata_2025_split huggingface dataset:
An electronic system for cardiac and metabolic evaluation
Authors: Kubicek W. G. , Patterson R. P. 
Published: December 2017

An electronic system was developed that: computes the oxygen consumption rate of a human subject while breathing room air; measures the flow rate of the expired air, expired air minute volume, tidal volume, arterial blood pressure, and pulse rate; and records the electrocardiogram. The flow rate of the expired air and the fraction concentrations of the CO2 and O2 in the expired air are measured with electronic gas analyzers and then electronically computed to give a continuous analog record of the oxygen consumption rate. All of the variables are continuously recorded in analog form. The average values of oxygen consumption rate, arterial blood pressure, or expired air minute volume and pulse rate are recorded in digital form with print out every minute. analog computer analysis of O2 consumption; continuous analog recording of expired airflow rate and minute volume, tidal volume, arterial blood pressure, and pulse rate; analog-to-digital conversion of O2 consumption, arterial blood pressure, pulse rate, and expired air minute volume; continuous recording of O2 consumption for subject breathing air; continuous electronic computation of O2 consumption Submitted on June 24, 1963
Electromotive force of transfer systems containing membranes
Authors: Nims Leslie F. , Kuo Jean 
Published: December 2017

Reversible Ag-AgCl electrodes have been inserted in the phases of a unit transfer system, phase agr, membrane, phase β, and the electromotive force of the chemical source of electromotive force so produced has been determined in the presence of varying material flows through the membrane. The measured electromotive force was found to be a linear function of the ion-pair chemical potential difference between the phases when the concentration of the salt in the more concentrated phase was less than 0.5 M. This relation implies that an electric transport number, a mutual property of the ion and the membrane, is constant over a wide concentration range when a single salt is present in the system. When the system is in a stationary state, the emf is a linear function of the flow rate of water over the concentration range studied. Two membranes whose electric transport numbers are different, a millipore filter and a cellophane membrane, were used to construct a closed circuit containing two aqueous homogeneous phases of different concentrations. Evidence is presented which demonstrates that a spontaneous electric current flows in such a closed circuit. membrane phenomena; electric transport number; nonequilibrium systems; electrochemical source of emf in closed circuits Submitted on June 6, 1963
Evaluation by dye dilution of the pressure-slope method for peripheral run-off
Authors: Pieper Heinz P. , Leverett Sidney D. 
Published: December 2017

The reliability of the pressure-slope method for the calculation of peripheral run-off rate has been demonstrated using the dye-dilution technique. The pressure-slope method yields a plot of peripheral run-off rate versus arterial pressure, for a given set of cardiovascular conditions. Under steady-state conditions, the peripheral runoff rate (total arterial outflow) must equal the cardiac output. Thus, a dye-dilution value for cardiac output was correlated with the mean arterial pressure at which it was determined, and then compared to the peripheral run-off rate at the same pressure. The results support the application of the pressure-slope method for the calculation of peripheral run-off rate (and also for the determination of cardiac output) in intact anesthetized dogs. total arterial outflow; cardiac output determination; pressure-flow relationships in the arterial system Submitted on December 17, 1962
Gas chromatography in determination of pulmonary diffusing capacity
Authors: Sasahara Arthur A. , Burleson Virginia A. 
Published: December 2017

Measurements of pulmonary diffusing capacity (Dco) were made using gas chromatography. The standard breath-holding technic was employed with the modification of using neon instead of helium for the dilution-reference gas. The two basic columns, silica gel, and 13 x molecular sieves were arranged in series on a dual-column chromatograph. All analyses were performed isothermally between 75–85 C with a carrier gas flow rate of 50–60 ml/min. Quantitation of the gas components was made simply and accurately by peak height measurements of the deflection curves on the chromatogram. The normal values for Dco by this method fall well within the range of normals determined by standard technics. The eminent suitability of gas chromatography for the determination of diffusing capacity derives from its simplicity, accuracy, and rapidity of gas analysis and its use of very small volumes of alveolar gas. breath-holding technic; neon; silica gel; 13 x molecular sieves; isothermic analysis; peak height measurements; dual-column chromatography Submitted on September 6, 1963
Quantitative evaluation of fibrinolytic enzymes in a simulated human system
Authors: Munson Albert E. , Back Nathan , Ambrus Clara M. , Lassman Howard , Lippschutz Eugene , Ambrus Julian L. 
Published: December 2017

A simple in vitro system for the assay of fibrinolytic enzymes intended for therapeutic use has been described. The system employs small quantities of human plasma from outdated bank blood as perfusing medium and purified human fibrin clots labeled with radioactive iodine. Thus, it is possible to follow the dissolution of a human clot without the intervention of reactions of the vascular system (e.g., release of activators). It was shown that the simulated system compares favorably with the in vivo assay. In the assay of a urokinase-activated human plasmin preparation, substitution of human plasma with dog plasma as a perfusing medium resulted in a decrease of the fibrinolytic response. In the case of two preparations, data from the simulated human system correlated well with results of preliminary clinical testing. In using this system as an initial screen for fibrinolytic agents, one must be aware of the fact that in vitro systems represent only part of the mechanisms involved in physiologic or pathologic processes. fibrinolysin system; plasmin; urokinase; thrombolysis; plasma Submitted on December 6, 1963
Calibrated vessel for one-step transfer decompression of fluids for gas analysis
Authors: Goodman M. W. , Barnwell G. 
Published: December 2017

This report describes a volumetrically calibrated (“to deliver”) glass vessel which has been devised to solve the following fluid-sampling and handling problem: an accurately measured aliquot of the liquid phase of a hyperbaric gas-liquid equilibration system was to be removed from a tonometer located inside a pressurized recompression chamber, decompressed to atmospheric pressure, and displaced into a vacuum extraction chamber for subsequent gas chromatographic analysis of inert gases. It was felt that the pressure change and the manipulative techniques occurring between the original equilibration and the final analysis comprised a constant and significant risk to the entire experiment. This anaerobic fluid-sample transfer vessel limits the entire decompression-transfer phase to a single step, and therefore minimizes opportunities for sample contamination or loss of evolved gas due to anaerobic handling accidents. hyperbaric exposure; liquid samples; blood-inert gas solubility; gas chromatographic sampling; vacuum extraction of dissolved gases Submitted on September 4, 1963
Cerebrovascular response to PaCOCO2 during halothane anesthesia in man
Authors: Alexander S. C. , Wollman H. , Cohen P. J. , Chase P. E. , Behar M. 
Published: December 2017

Twenty-four measurements of cerebral blood flow (CBF) were made with Kr85 in 13 normal unpremedicated male subjects during halothane anesthesia. Mean end-tidal halothane concentration was 0.98%. Ve was maintained constant in each subject at about 12 liters/min and inhaled co2 concentration was varied so that PaCOCO2 ranged between 19–56 mm Hg. Mean cerebral perfusion pressure varied from 41.0 to 76.4 mm Hg and tended to be lower at PaCOCO2 levels >47 mm Hg. CBF varied linearly with PaCOCO2 under the conditions of this study. The response of the cerebral circulation to change in PaCOCO2 during halothane anesthesia is compared with changes observed by others in awake man and in anesthetized animals. The shape of the PaCOCO2 response curve was observed to be altered by the vasodilatation which occurred during halothane anesthesia. The Kr85 method of calculating CBF is superior to the nitrous oxide technique because of krypton's lower blood solubility and more rapid equilibration. cerebral blood flow; general anesthesia; carbon dioxide Submitted on December 23, 1963
Heat reactions of Caucasians and Bantu in South Africa
Authors: Wyndham C. H. , Strydom N. B. , Morrison J. F. , Williams C. G. , Bredell G. A. G. , Von Rahden M. J. E. , Holdsworth L. D. , Van Graan C. H. , Van Rensburg A. J. , Munro A. 
Published: December 2017

Heat reactions of 20 Caucasian and 22 Bantu males were compared, first in the unacclimatized state and then in the acclimatized state. The study was conducted at temperatures of 90 F wet-bulb and 93 F dry-bulb at a work rate of 1 liter O2/min consumption. The performances of the unacclimatized Bantu were superior to those of the Caucasians. All 22 Bantu completed the 4-hr experiment, while 10 Caucasians failed. The mean rectal temperature of the Bantu was significantly lower than that of the Caucasians, but not the mean heart rate and mean sweat rate. When both groups were highly acclimatized all men from both groups completed the 4-hr experiment, and their reactions to heat were significantly different from their reactions in the unacclimatized state. Sweat rates, particularly, increased very much. The differences between the two highly acclimatized groups in rectal temperatures, heart rates, and sweat rates (except the 4th hr) were not significant. Although superior in the unacclimatized state, the Bantu does not appear to have an inherent advantage in the ability to regulate the body temperature. Caucasians versus Bantu in reactions to heat; physiological reactions in exposure to heat Submitted on August 19, 1963
Heat reactions of Caucasians in temperate, in hot, dry, and in hot, humid climates
Authors: Wyndham C. H. , Strydom N. B. , Munro A. , MacPherson R. K. , Metz B. , Schaff G. , Schieber J. 
Published: December 2017

Heat reactions of Australian Caucasians living in hot, humid climates and of French Caucasians living in hot, dry climates were compared to unacclimatized and highly acclimatized male Caucasians living in Johannesburg. The experiments were conducted in climatic chambers at temperatures of 90 F wet-bulb and 93 F dry-bulb, and a workload of 1 liter O2/min consumption. The Australians did not differ significantly from the French in the three reactions to heat, except for a slightly significantly higher sweat rate in the 1st hr. The French and Australians had lower mean rectal temperatures and heart rates and higher sweat rates than the unacclimatized South Africans. Although the trend is toward a significant difference for all hours, the differences are not always significant. Living and working in the hot, humid tropics and in the hot, dry desert evidently confers a certain measure of acclimatization to heat. Quantitatively this can be expressed as 50% of the difference between unacclimatized and acclimatized men. This is, however, considerably less than the condition achieved by systematic artificial acclimatization. Australian versus French Caucasians in heat reactions; effects of various climates on Caucasians; heat reactions in the desert; heat reactions in the tropics; physiological effects of hot, dry and hot, humid climates Submitted on August 19, 1963
Continuous measurement of ventilatory exchange ratio during exercise
Authors: Naimark Arnold , Wasserman Karlman , McIlroy Malcolm B. 
Published: December 2017

The ventilatory gas exchange ratio (R) has been measured continuously during exercise from end-tidal CO2 and N2 concentrations recorded with gas analyzers. Studies in normal subjects and patients with different working capacities indicate that the change in R at different levels of work lasting several minutes on an ergometer gives an excellent measure of the balance between oxygen supply and demand in the working muscles. The level of work at which R increases appreciably above its resting level corresponds to the level at which arterial lactate increases and plasma bicarbonate falls. The continuous measurement of R can be readily incorporated into work tests for the assessment of exercise performance in both normal subjects and patients with cardiovascular diseases. blood bicarbonate; work test; anaerobic metabolism; physical fitness; blood lactate Submitted on December 30, 1963
Pulmonary exchange as related to altered pulmonary mechanics in anesthetized dogs
Authors: Collier Clarence R. , Mead Jere 
Published: December 2017

Pulmonary mechanics and gas exchange were studied in supine anesthetized dogs, with and without periodic hyperinflations of the lungs, and after a single forced deflation. After a period without hyperinflations the lung compliance decreased to 66% of control values and patchy atelectasis was observed, but no changes were observed in diffusing capacity (Dl) or per cent venous admixture ( Qva/ Qt). Following a single forced deflation the compliance was 40% of control. Dl was 40% and Qva/ Qt 180% of control values, respectively. These data could be accounted for if there was an accompanying shift of blood flow from atelectatic to nonatelectatic areas, the compensation being very nearly complete for moderate, but less than complete for marked reductions in compliance. Alternative explanations of the apparent compensation are: 1) preferential initial atelectasis of regions with high ventilation-perfusion ratios (as proposed by Farhi) and 2) substantial reductions in compliance without closure of air space, as might result from changes in surface forces with time. aerotonometer; atelectasis; venous admixture; mechanics of breathing; compliance of dog lungs; diffusion capacity of dog lungs; ventilation perfusion; relationships of dog lungs Submitted on October 28, 1963
Continuous distribution of specific tidal volume throughout the lung
Authors: Gómez Domingo M. , Briscoe William A. , Cumming Gordon 
Published: December 2017

An analytical method is presented which, applied to nitrogen washout data from the lung, describes a continuous distribution of specific tidal volume (or ventilation) throughout the air phase of the lung. The technique of computation is described in some detail. Curves of distribution of specific tidal volume are studied for 12 washout data from normal subjects and for 20 washout data from patients with pulmonary emphysema. In normal subjects the pattern of continuous distribution is an asymmetrical one in which the function starts at zero or very nearly so, increases continuously until it reaches a maximum value, then decreases progressively and becomes negligible for comparatively high values of the specific tidal volume. The formulation expressing this law of distribution is neither that of a normal frequency distribution nor that of a log normal one. With increasing over-all tidal volume in normal subjects the curve is progressively displaced toward the right. In contrast, in pulmonary obstructive diseases the maximum amplitude takes place for very low values of the specific tidal volume and tends to vanish slowly toward values that are higher than in the normal subjects. apparent volume of lung Submitted on June 20, 1963
Distribution of blood flow in isolated lung; relation to vascular and alveolar pressures
Authors: West J. B. , Dollery C. T. , Naimark A. 
Published: December 2017

The left lung from a dog was removed, ventilated with negative pressure, and perfused with venous blood. Pulmonary arterial, venous, and alveolar pressures could be varied over a large range. The distribution of blood flow in the lung was measured with Xe133. Under these conditions, there was no blood flow above the level at which alveolar equaled arterial pressure (measured at the arterial cannula). Below this level there was a linear increase in blood flow down the lung when the venous pressure was kept low. Raising the venous pressure made the distribution of flow more uniform below the level at which venous and alveolar pressures were equal although flow still increased down this zone. The flow distribution could be completely accounted for by the mechanical effects of the pressure inside and outside the blood vessels which each behaved like a Starling resistance. It was possible to simulate the flow distributions found in man in various physiological and diseased states. pulmonary; hydrostatic effect; Starling resistance Submitted on November 15, 1963
Alveolar carbon dioxide equilibria in breath-holding experiments
Authors: Barth Delbert S. , Stacy Ralph W. 
Published: December 2017

An investigation was made of the equilibria approached by alveolar CO2 tension in normal human subjects during breath holding. A major objective of this work was to test the hypothesis that the approached equilibrium was with deoxygenated venous rather than with oxygenated venous blood. The study included determination of CO2 tension of expired air by continuous recording before and after breath holding for various time periods, with simultaneous airflow recordings. Pulmonary blood flows were calculated from these data, and were compared with those obtained by an independent rebreathing technique. The findings indicate that the equilibrium approached in the alveolar spaces during breath holding is between the alveolar air and the blood as it enters the pulmonary capillary. This would indicate that CO2 dumping by passive transfer must precede the uptake of oxygen. Effective pulmonary flows calculated from these data were reproducible and in agreement with those obtained by the rebreathing technique. human pulmonary blood flows; alveolar CO2 transport properties; CO2 rebreathing in humans Submitted on July 22, 1963
Static volume-pressure characteristics of the respiratory system during maximal efforts
Authors: Cook Charles D. , Mead Jere , Orzalesi Marcello M. 
Published: December 2017

Maximal expiratory and inspiratory static airway pressures at different lung volumes were measured in 56 normal subjects of both sexes ranging in age from 6 to 64 years. A new method was used requiring a special mouthpiece, a series of containers of different volumes (allowing volume combinations from 1.5 to 200 liters), and a manometer. The subjects breathed into or out of the containers as forcibly as possible; the lung volumes corresponding to the maximal pressures developed were calculated by Boyle's law. The results are compared with those obtained by other authors. The maximal pressures developed by our subjects, particularly on expiration, were considerably higher than most published values. This was probably the result of using a special mouthpiece which provided an adequate seal even at high pressures. One experienced subject obtained pressures as high as 300 cm H2O on expiration and 200 cm H2O on inspiration. strength; muscles; pressures; chest Submitted on November 29, 1963
Performance of a new on-line computer for indicator-dilution curves
Authors: Wessel Hans U. , Hepner Charles F. , James Gordon W. , Kezdi Paul 
Published: December 2017

An analog computer was designed for on-line computation of the area under indicator-dilution curves. From a model circulation and from two dogs, 165 tricarbocyanine green dilution curves were recorded with a cuvette densitometer, together with the computed area and signals indicating 60% and 30% of the peak deflection on the down slope of the curve. An IBM 709 digital computer was programmed to compare automatically and conventionally computed flow rates, to analyze sources of error in the computer, and to determine the goodness of fit of the extrapolated exponentials. The results indicated stable operation of the computer. The mean difference between the computer and graphic integration was minus 1.0% ± 2.4% for 78 flow estimates in the model, and 1.9% ± 2.5% for 30 cardiac output in the dogs. Data suggest that the computer does not introduce a significant error provided the dilution curves are also suitable for established graphic methods of integration. special purpose analog computer; instrumentation; cardiac output Submitted on December 6, 1963
O2 solubility in blood and temperature correction factors for Po2
Authors: Hedley-Whyte J. , Laver M. B. 
Published: December 2017

Tonometry of 100 paired samples of blood and measurement of Po2 before and after warming in a sealed syringe showed that the relative solubility of O2 (αB/αHh2O) in fully saturated blood is constant at all temperatures between 24.5 and 38 C, i.e., fully saturated blood appears to behave as a dilute aqueous solution. When Po2 is kept constant during cooling the relative increase in dissolved O2 in blood is the same as with water. Thus, when cooling from 38 to 20 C the increase in dissolved O2, if Po2 is kept constant, is 31%. Correction factors for the effect of temperature on Po2 of blood warmed to 38 C can be based on ratios of αHh2O38/αHh20T. These factors were found to give adequate correction at O2 tensions above 250 mm Hg. Inaccuracies were found when previously proposed factors were applied to blood having a Po2 of 300 mm Hg. These results were interpreted as showing that blood is essentially fully saturated at a Po2 of approximately 250 mm Hg. Note (With the Technical Assistance of A. Murphy and A. Seifen) relative solubility; agr; hypothermia; hemoglobin; dissociation; tonometry; O2 electrode; physiologic shunt Submitted on December 23, 1963
Pulmonary and systemic hemodynamics of passively hyperventilated dogs
Authors: Linde Leonard M. , Simmons Daniel H. , Shapiro Bertrand J. , Goldberg Stanley 
Published: December 2017

The effects of respiratory alkalosis on pulmonary and systemic hemodynamics in the intact anesthetized dog were measured and compared to a control period with normal pH and pCO2. Pulmonary artery, pulmonary vein, and systemic artery pressures were measured through fluoroscopically placed cardiac catheters. Transmural pressures were determined by subtraction of intrapleural from vascular pressures. Cardiac output was determined in duplicate by the indicator-dilution technique using Cardio-green. Respiratory alkalosis in passively hyperventilated intact anesthetized dogs did not significantly alter cardiac output, or systemic or pulmonary vascular resistance in 13 experiments. The possibility that increased intratracheal pressure during hyperventilation may have mechanically masked a decrease in pulmonary vascular resistance was ruled out in a second series of 17 experiments in which intratracheal pressure was maintained constant. An inverse relationship between pulmonary vascular resistance and pH was not found in this study. Note: (With the Technical Assistance of Robert Powell) pulmonary vascular resistance; pulmonary circulation; respiratory alkalosis; acid-base effects; cardiac output Submitted on December 19, 1963