bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vascular and sweating responses to regional heating of the body surface
Authors: Rawson Robert O. , Randall Walter C. 
Published: December 2017

The significance of cutaneous and internal thermoreceptors in human temperature regulation was studied by exposing the subject simultaneously to environmental temperatures of 25 and 60 C. Cutaneous, rectal, and tympanic membrane temperatures were recorded along with sudomotor and vasomotor responses. Heat stress to the lower half of the body was accompanied by marked differential vasomotor responses and a pronounced caudal-to-rostral recruitment of sweating in spite of an unchanging or declining tympanic membrane temperature. Heating the upper half resulted in essentially the same vasomotor and sudomotor responses but with significant alteration in the time course and intensity of the sweat recruitment pattern. With sudden lowering of the ambient temperature, sweating on all areas disappeared while internal temperatures remained unchanged. It is clearly demonstrated that under the given experimental conditions both cutaneous and internal thermoreceptors play a significant role in human temperature regulation and that the hypothalamus is not the sole moderator of internal temperature control. Submitted on July 16, 1961
Age-related changes in erythrocyte agglutinability in Hiroshima subjects
Authors: Hollingsworth J. W. , Hamilton H. B. , Ishii G. 
Published: December 2017

As part of a physiologic aging assessment in survivors of the atomic bombing, agglutinability of erythrocytes with A and B antisera was studied in 1,495 subjects in Hiroshima. It was found that erythrocyte agglutinability is maximal during the third decade and falls progressively with advancing years. At age 20—40, agglutinability of erythrocytes from females was somewhat less than that of males. Subjects of blood group AB demonstrated agglutinability titers with both antisera comparable to the titers of the group A and B subjects. Analysis of agglutinability titers in relationship to degree of irradiation from the Hiroshima atomic bomb in 1945 failed to show differences, but the sample was too small to allow definite conclusions about possible radiation-accelerated aging. Note: With the Technical Assistance of N. Ueda Submitted on February 16, 1961
Oxygen uptake during the first minutes of heavy muscular exercise
Authors: &Aring;strand Per-Olof , Saltin Bengt 
Published: December 2017

Oxygen uptake, heart rate, pulmonary ventilation, and blood lactic acid were studied in five subjects performing maximal work on a bicycle ergometer. After a 10-min warming up period work loads were varied so that exhaustion terminated exercise after about 2—8 min. Peak oxygen uptake and heart rate were practically identical (sd 3.1% and 3 beats/minute, respectively) in the experiments. The heavier the work was and the shorter the work time the higher became the pulmonary ventilation. There was a more rapid increase in the functions studied when the heaviest work loads were performed. It is concluded that aerobic capacity can be measured in a work test of from a few up to about 8 min duration, severity of work determining the actual work time necessary. Duration of work in studies of circulation and respiration during submaximal work should exceed 5 min. Submitted on June 23, 1961
Interpretation of radioactive gas clearance rates in the lung
Authors: West J. B. , Holland R. A. B. , Dollery C. T. , Matthews C. M. E. 
Published: December 2017

The clearance rates of short-lived radioactive gases from defined areas of the lung have been used to measure regional blood flow and gas exchange. The clearance rates are measured by external counting over the chest during a short period of breath holding following a rapid inspiration of the gas. Two processes are necessary for the clearance of any radioactive gas from the counting field, namely, transfer from alveolar gas to pulmonary capillary blood, and subsequent removal of the active gas from the field. Recently it has been shown that oxygen-labeled CO2 is lost from alveolar gas exceedingly rapidly, and it can therefore be used to separate these two clearance rate processes. A theoretical analysis shows how that can be done, and experiments designed to test the theory are described. Although considerable approximations are necessary, the analysis clarifies the factors controlling the clearance rate of any radioactive gas. One consequence is that the large variations in the regional uptake of radioactive CO and O2 previously reported are probably overestimates. Submitted on December 7, 1960
Heart sounds of healthy Macaca mulatta
Authors: Hamlin Robert L. , Robinson F. R. , Smith C. R. , Marsland William P. 
Published: December 2017

Heart sounds were recorded from 13 healthy Macaca mulatta. The first heart sound began 0.036 sec after onset of QRS. Mean duration was 0.074 sec with an average of 6.4 vibrations. The period of systole was silent in all animals, and had a mean duration of 0.190 sec. The second heart sound was lower in magnitude than the first. Mean duration was 0.038 sec, with an average of 3.5 vibrations. The period of diastole was silent in nine animals and exhibited low frequency vibrations throughout the entire period in four animals. The average duration of diastole was 0.157 sec. Submitted on August 16, 1961
Mechanical function of the main pulmonary artery
Authors: Patel Dali J. , De Freitas Flavio M. , Mallos Alexander J. 
Published: December 2017

The relationship among the longitudinal strain, circumferential strain, lateral intravascular pressure, blood flow, and longitudinal motion was examined in the main pulmonary artery of living, open-chested dogs. Results indicate: 1) The mean value for longitudinal extensibility was 0.73% change in length per centimeter of water pressure (± .19 sd ± .04 sem). 2) The mean value for volume distensibility was 2.28% change in volume per centimeter of water pressure (± .9 sd ± .17 sem). 3) The magnitude of the radial vessel wall velocity is small. 4) The magnitude of the longitudinal vessel wall velocity, though small over most of the cardiac cycle, may become significant at the beginning of cardiac systole, especially during isoproterenol administration. Submitted on October 3, 1961
Effects of fat emulsion on O2 transport and alveolar-arterial gas tensions
Authors: Cain Stephen M. 
Published: December 2017

Ten dogs were made progressively hypoxic by rebreathing from an air-filled spirometer. Arterial blood samples were drawn at five levels of alveolar Po2 (100, 70, 55, 40, and 25 mm Hg), as well as samples before and after the hypoxia for O2-capacity determinations. Half the animals then were given 25 ml/kg of fat emulsion intravenously and the others were given the same amount of dextran. The same sampling procedure was repeated and the blood was analyzed for O2 content. In separate experiments, the same procedure was followed for five dogs but only fat emulsion was given and the arterial blood was analyzed for Po2 and Pco2. Oxyhemoglobin dissociation curves were constructed from the values of saturation at progressively falling alveolar o2. These were transformed into a linear equation by the Hill equation and treated statistically. No significant differences were found between any of the comparisons of slope or displacement. It was concluded that lipemia offered no practical hindrance to the uptake of O2 by the red cell. Alveolar-arterial gas tension differences revealed no change after intravenous fat emulsion in the Po2 difference, but there was a threefold increase in the Pco2 difference. Submitted on June 12, 1961
Gas composition of pressurized, perfused gas pockets and the fish swim bladder
Authors: Piiper J. , Humphrey H. T. , Rahn H. 
Published: December 2017

The behavior of the composition of pressurized, perfused gas pockets is analyzed in theory and experimentally, with the aim of contributing to the understanding of the effect of differential absorption on the composition of the fish swim bladder gas. The equations describing the change in the composition of pressurized, perfused gas pockets are derived and experimentally verified. If a gas pocket initially containing room air is subjected to elevated pressure and perfused with water equilibrated with room air, the concentration of the less soluble gas nitrogen increases during the absorption process. High partial pressures of nitrogen and argon found in swim bladders of fish living at great depths can be qualitatively explained on the basis of accumulation of these gases by preferential absorption of oxygen and carbon dioxide, in connection with certain assumptions on the mode of secretion of the gases Submitted on October 9, 1961
Measurement of the thermal pain threshold of the hard palate
Authors: Margarida R. , Hardy J. D. , Hammel H. T. 
Published: December 2017

Using thin-walled aluminum thermodes individually fitted to the roof of the mouth, the pain threshold of the hard palate was measured in four subjects. By rapidly circulating hot water and water at 37 C alternately, the temperature of the thermode could be raised and lowered between a neutral and a test level. Temperature within the thermode was measured in every observation by a fine wire thermocouple in the circulating water. Temperature between the thermode and the hard palate was also measured over the entire range of temperatures studied, and a correction for the gradient across the thermode wall was determined and applied to the water temperature. Stimuli between 40 C and 49 C were administered. Each subject was exposed to 288 stimuli in six experimental periods. The range of stimuli reported as painful was from 44.5 C for the first reports of pain to 47.7 C which always evoked pain. A preliminary study was made of the buccal temperature changes occurring during drinking hot beverages, and evidence indicates the sipping of air with small amounts of the hot liquid maintains the tissue temperatures within tolerable limits. Submitted on November 22, 1961
Diffusing capacity of the lung for carbon monoxide at high altitude
Authors: West J. B. 
Published: December 2017

Diffusing capacity of the lung for carbon monoxide (Dl) was measured in London (Pb approx. 750 mm Hg), at 15,300 ft (4,700 m; Pb approx. 440 mm Hg), and at 19,000 ft (5,800 m; Pb approx. 380 mm Hg) on seven members of the Himalayan Scientific and Mountaineering Expedition, 1960–61. At each altitude Dl was measured at two work levels (300 and 900 kg-m/min) and at three different inspired oxygen tensions in order to separate membrane and blood components of the diffusing barrier. A steady state method was used with mixed expired gas analysis; dead space-to-tidal volume ratio was assumed but calculated Dl was insensitive to this. There was no consistent change in Dl at 15,300 ft (subjects breathing ambient air) compared with sea level, but Dl was significantly increased after 7–10 weeks at 19,000 ft (mean changes of 15 and 19% for work levels of 300 and 900 kg-m/min, respectively). However, this small change in Dl can be wholly accounted for by the increased rate of reaction of carbon monoxide with hemoglobin due to hypoxia and by the increased blood hemoglobin concentration. Submitted on September 7, 1961
Ventricular asynchronism in the dog
Authors: Samet Philip , Bernstein William H. , Litwak Robert S. 
Published: December 2017

Dissociation of electrical and mechanical asynchronism in the canine right and left ventricles has been studied by simultaneous registration of right and left ventricular pressure and strain gauge arch curves and the electrocardiogram. Observations were made during sinus rhythm and during acetylstrophanthidin-induced ventricular premature beats with widened aberrant QRS complexes. The data demonstrate only limited mechanical asynchronism during the asynchronous electrical depolarization of ventricular premature systoles. Submitted on October 19, 1961
Evaluation of slope method for measuring pulmonary blood volume in man
Authors: McGuire Lockhart B. , Dock Donald S. , Hyland John W. , Harrison Donald C. , Haynes Florence W. , Dexter Lewis 
Published: December 2017

Knowledge of the pulmonary blood volume is important in several areas of circulatory physiology. However, adequate methods for measuring this volume have not been established. The slope of an indicator-dilution curve across the central circulation has been used in several studies as an indication of this volume. In the present study the blood volume between pulmonary artery and left atrium was measured in 31 human subjects by an application of the well-established mean transit time principle. Slope volumes were also measured. There was poor agreement between the results of the two techniques. Unilateral pulmonary artery occlusion consistently reduced pulmonary blood volume by the mean transit time method, with only minor and less consistent changes in slope volumes. A close correlation between the slopes of curves from simultaneous pulmonary artery and left atrial injections suggested a predominant effect on both curves of factors at or distal to the left side of the heart. It was concluded that the slope method did not measure the pulmonary blood volume in man. Submitted on June 8, 1961
Effect of acetazolamide on secretion of sodium and potassium by the human stomach
Authors: Lindner A. E. , Cohen N. , Dreiling D. A. , Janowitz H. D. 
Published: December 2017

The effect of intravenous infusion of the carbonic anhydrase inhibitor, acetazolamide (Diamox), on the secretion of sodium and potassium by the unstimulated (basal) and histamine-stimulated stomach has been studied in 20 human subjects, using a dosage of 50–100 mg/kg of the drug. Acetazolamide causes a decrease in output of Na and K ions, as well as a decrease in the output of HCI. These effects are more marked after histamine. The reduction in output of K is directly correlated with the reduction in volume rate; however, the decrease in Na output is less than can be accounted for by flow rates. The familiar inverse relationship between concentrations of sodium and hydrogen ions persists after acetazolamide. The effects of actazolamide on secretion of Na and K are believed to follow changes induced by the compound on the primary mechanism of acid secretion. Submitted on October 30, 1961
Diuresis associated with prolonged water immersion
Authors: Graveline Duane E. , Jackson Margaret M. 
Published: December 2017

Utilizing complete water immersion, compensated respiration, and unrestricted activity, the diuretic response of five human subjects to 6-hr periods in this environment was studied. The results indicate that the low specific gravity diuresis which occurs in this situation has characteristics of both a water and an osmotic diuresis. Possible physiologic mechanisms are discussed. Submitted on September 13, 1961
In vivo studies with an intravascular and intracardiac reflection oximeter
Authors: Enson Y. , Briscoe W. A. , Polanyi M. L. , Cournand A. 
Published: December 2017

An oximeter is described which employs two bundles of flexible glass fibers to conduct appropriately filtered light into, and that light diffusely reflected by the blood out of, the blood stream for the determination of oxygen saturation or dye concentration within blood flowing past the tip of either an arterial needle or a cardiac catheter which contains both bundles. The ratio of intensities of the reflected light at two wavelengths is linearly related to oxygen saturation (IRR805/ IRR660) and dye concentration (IRR900/IRR805). Data is reported in vivo and in vitro with respect to accuracy of the determinations (± 1.9%). The effect of patient-to-patient variation in hematocrit and other factors, and of pulsatile blood flow, is described. Application of the technique to physiologic study is illustrated, and theoretical aspects of reflection oximetry, as they apply to the instrument, are discussed. Submitted on November 17, 1961
Measurement of pulmonary blood flow during exercise using nitrous oxide
Authors: Becklake Margaret R. , Varvis C. J. , Pengelly L. D. , Kenning S. , McGregor M. , Bates D. V. 
Published: December 2017

Pulmonary capillary blood flow (Qc) in the exercising subject was calculated from the rate of disappearance of N2O during steady state breathing of an N2O-He-O2 mixture. Measurements were made after alveolar rinsing (reciprocal of N2 washout) had occurred, and up to 30 sec, a time period accompanied by minimal recirculation, since FaNN2O during this period did not rise significantly. Repeatability of the method, judged as the difference of a second estimate from a first on the same subject, was comparable to that reported for the direct Fick technique in resting subjects (31 of 33 paired observations agreed within 20%). Results over a wide range agreed with almost simultaneous measurements by a dye dilution technique (24 of 26 paired observations agreed within 20%), and when related to pulse rate and to Vo2, were comparable to those of the other workers whose subjects were studied in a similar posture. Indeed, this technique (using the indirect Fick principle under “steady state” conditions) probably attains its greatest accuracy during exercise when other methods become less easily applicable. Submitted on December 18, 1961
Effects of salicylates on exercise metabolism
Authors: Downey John A. , Darling Robert C. 
Published: December 2017

Some metabolic effects of salicylates were measured on ten normal young males steadily performing controlled moderate exercise after administration of acetyl salicylic acid (ASA). Dosages at a rate up to 4.8 g/day were administered over lengthening periods, the last dose 1frac12–2 hr before walking on a power-driven treadmill in a temperature-controlled room. Oxygen consumption was measured, as were pulmonary ventilation, pulse rate, and blood lactic acid. While analysis of results indicated increase in resting O2 consumption within 2 hr of the first dose, no modification of O2 consumption of exercise appeared. Pulmonary ventilation was not increased after one dose, but did increase at rest, during exercise, and recovery after longer dosage; O2 extraction from each unit of ventilation increased after one dose at rest and during exercise; the extraction ratio was still increased at rest after longer administration of ASA, but decreased during exercise and recovery. Increased ventilation was predominantly effected by increased depth of respiration rather than by changes in rate. Pulse rates were not changed and no significant effects on the cardiovascular system were discerned in this respect. Submitted on March 10, 1962
Maze acquisition and retention in hypothermic mice
Authors: Sudak Frederick N. , Essman Walter B. 
Published: December 2017

Three experiments were carried out to demonstrate the relation between learning and retention as affected by a reduction of colonic temperature in mice. Animals rendered hypothermic (T Ε = 3.3 C, 3.4 C) by treatment with 2,4-dichlorophenoxyacetic acid and exposure to cold air (2.0±0.5 C) did not acquire a simple escape response from a water maze within ten training trials. Saline-treated control animals demonstrated acquisition within four trials under similar conditions. Retention of the maze habit was a function of acquisition during training. Retention scores, as well as performance measures, were not affected by a comparable reduction in colonic temperature. Note: (With the Technical Assistance of J. R. Blumstein and D. Pennec) Submitted on January 22, 1962
Right-to-left shunt in normal man determined by the use of tritium and krypton 85
Authors: Mellemgaard K. , Lassen N. A. , Georg J. 
Published: December 2017

An aqueous solution of tritium and krypton 85 together with Evans blue dye was injected intravenously in twelve normal subjects during quiet breathing, during apnea, and during voluntary hyperventilation. Arterial blood was sampled within the first 30 sec after the injection to measure the recovery of the two gases. Blood-gas partition coefficients of the two gases at 37 C were determined experimentally and the ratio between them was found to be 3.8 in normal blood. Knowing this ratio it is possible to calculate the fraction of the arterial recovery due to a right-to-left shunt, and that due to alveolar back pressure. The shunt calculated from findings during quiet breathing is 0.26% of the cardiac output. Recoveries during apnea lead to a calculated shunt of identical size, whereas the shunt calculated from the experiments during hyperventilation amounts to only 0.11% of the cardiac output. Submitted on March 8, 1962
Response of lung volumes and ventilation to posture change and upright exercise
Authors: Hanson John S. , Tabakin Burton S. , Caldwell Edgar J. 
Published: December 2017

Variations in size of the various lung volumes due to changes in body position and as a consequence of treadmill exercise were studied in five normal males. Assumption of the upright posture was associated with highly significant increases in total lung capacity, vital capacity, expiratory reserve volume, and residual volume as compared to resting supine values. Level walking was associated with a decrease of expiratory reserve volume, but a further expansion of residual volume. Vital capacity decreased slightly, but total lung capacity increased by virtue of the proportionately large residual volume increases. Elevation of the treadmill to 4° resulted in slight decreases in all lung volumes, total lung capacity evidencing a barely significant decline. Positional changes in ventilation are described, and on the basis of the “lung clearance index” an increased efficiency of ventilation is seen in the upright posture. Factors possibly operative in these alterations are discussed. Submitted on February 21, 1962
Reflex airway reaction to fluid aspiration
Authors: Colebatch H. J. H. , Halmagyi D. F. J. 
Published: December 2017

The mechanism of the lung mechanics changes after fluid aspiration was investigated in sheep, intubated and lightly anesthetized with thiopentone. The increase in venous admixture after intratracheal injection of fluid while breathing 100% oxygen indicated airway closure as the explanation for the associated gross fall in lung compliance (Cl). Atropine sulfate reduced the Cl fall produced by 1 ml/kg body wt. of fluid to a significantly greater extent than prior vagotomy. In vagotomized animals the reaction to fresh water was potententiated by prostigmine. A nonfoaming fluid with a surface tension of 27 dynes/cm had the same effect as fresh water. The reaction to water was not affected by lysergic acid butanolamide or aerosol tetracaine. Intravenous or aerosol isoproterenol reduced the Cl fall after water. These findings show that fluid aspiration invokes a reflex response of the parasympathetic nervous system, with both central and peripheral components producing closure of lung units. The relation of this reflex to other respiratory reflexes is discussed. When inflation alone was ineffective or lead to deterioration, both atropine and isoproterenol helped to reverse the effects of sea and fresh water. Submitted on March 8, 1962
CO2 and acid-base transients after hyperventilation
Authors: Lipsky Joseph A. , Tomashefski Joseph F. , Carter Earl T. 
Published: December 2017

Fourteen male subjects were mechanically hyperventilated by intermittent positive pressure breathing. Tidal volume and respiratory frequency were increased approximately three times and one and one-half times control, respectively. Breath-by-breath analyses of CO2 output indicate a loss of approximately 2.5 liters of CO2 from the body stores in 12 min. Only one-third of that volume was restored during the ensuing 12-min recovery period, mostly as a result of hypoventilation rather than apnea. Over the entire recovery period, the volume of CO2 regained by the blood store approximated 75% of the CO2 content lost during hyperventilation. Under the conditions of these experiments, tissues regained less than 20% of the depleted CO2 store. CO2 retention patterns may be more effective than arterial blood or alveolar air analyses in determining a return to a steady state when tissue stores have been considerably reduced. Submitted on August 24, 1961