bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of varying inspired O2 tension on alveolar-arterial O2 tension difference in man
Authors: Cole R. B. , Bishop J. M. 
Published: December 2017

Alveolar-arterial oxygen tension difference (A-aD) and physiological dead space were measured in 16 normal men and women selected equally from the age groups 20–29 and 50–59 years, at mean alveolar oxygen tensions (PaOO2) of 107, 291, and 653 mm Hg. Arterial oxygen tension was measured polarographically and arterial carbon dioxide tension by an interpolation method. Values for A-aD were not related to posture but were significantly greater in the older group. Mean values for A-aD in the younger group were 8.7, 23.5, and 6.1 mm Hg at the three levels of PaOO2, respectively, and 14.1, 44.5, and 21.3 mm Hg, respectively, among the older group. At the two lower levels of PaOO2 results were in general agreement with those of previous workers, but a significant decrease in A-aD was observed when PaOO2 was raised to 653 mm Hg. It is suggested that this finding may be due either to change in the effective size of anatomical shunt while breathing 99.5% oxygen, or to a significant distribution component of total A-aD at the intermediate alveolar oxygen tension. effect of posture, age and sex; physiological dead space; veno-arterial shunt Submitted on April 23, 1963
Effects of epinephrine on cardiovascular and metabolic responses to leg exercise in man
Authors: Marshall Robert J. , Shepherd John T. 
Published: December 2017

In studies on six experienced subjects lying supine, cardiac output and oxygen content of femoral venous blood were measured with the subject at rest, during the increase in muscle blood flow caused by intravenous infusion of epinephrine, during mild leg exercise, and during identical exercise combined with an infusion. The oxygen content of the blood from the exercising limb was much higher (average, 50%) during an infusion than when no infusion was given (average, 32%). The mean increase in cardiac output during the combined maneuver (8.2 liters/min) almost equaled the sum of the increases during the separate infusion (3.7 liters) and during exercise (4.7 liters). All individual studies showed approximately this same result. Thus, the additional blood supplied to the leg muscles by the infusion did not appear to be used for metabolic purposes during exercise. cardiac output; muscle blood flow Submitted on March 22, 1963
Effect of diet on fasting blood glucose levels in dairy calves 1 to 13 weeks old
Authors: Attebery John T. , Colvin Harry W. 
Published: December 2017

Fourteen male Holstein-Fresian calves, 3–4 days of age, were placed on one of four diets for a 13-week experimental period. The diets included the following: milk and milk solids; milk and grain; milk, grain, and hay, inoculated (rumen ingesta from a mature steer introduced via stomach tube into the rumen of an experimental calf); or milk and grain, inoculated. Significant differences were noted in the effect of diet, age, and the interaction of diet and age on the fasting level of blood glucose. The calves on the diet containing milk and milk solids maintained a constant level of fasting blood glucose; however, the inclusion of grain and hay in the diet resulted in a decline of the fasting blood glucose. The rumen inoculation of one of the groups of calves on the milk and grain diet did not result in a fasting blood glucose which was statistically different from that of the calves not inoculated. ruminant blood glucose; diet and age interaction; milk solids Submitted on February 26, 1963
Continuous intra-arterial Po2 in normal man using a flexible microelectrode
Authors: Charlton G. , Read David , Read John 
Published: December 2017

A flexible microelectrode, for continuous recording of blood oxygen tension, has been developed for direct insertion into small blood vessels or passage through a cardiac catheter. The design overcomes difficulties arising from pressure of the oxygen-permeable membrane against the vessel wall and greatly increases the robustness and effective life of the electrode. For routine intra-arterial use a satisfactory compromise has been achieved between speed of response (95% in 15 sec), cathode current (3 x 10-11 amp/mm Hg Po2), and freedom from “stirring” artefact (less than 3%). Serial in vitro readings of Po2 over periods of 4 hr have been reproducible (2 sd ± 3% pro rata) without recalibration. In vivo accuracy and stability have been established by continuous recording of Po2 within the brachial artery of six nonheparinized humans for periods up to 1 hr. The maximum difference observed between initial in vivo and in vitro readings was 2.5%. The reproducibility of serial washout and washin curves has been analyzed to provide an indication of in vivo stability. The technique is safe provided that the precautions outlined to prevent thromboemboli are carefully followed. electroanalytical chemistry; polarography; respiratory physiology; oxygen tension in biological fluids Submitted on December 26, 1962
Simultaneous assay of K42, Na24, and Br82 in body composition measurements
Authors: Boling E. A. , Rossmeisl E. , McLean R. , Alpert H. , Gardner R. , Halpin M. , Lipkind J. B. 
Published: December 2017

Simultaneous measurements of Na24 and K42 specific activities may be based on chemical, physical, or metabolic differences between these two radioisotopes. This paper describes a rapid and precise technique based on both physical and metabolic differences. Two counters, a gamma-ray and a beta-ray counter, are used. Two samples are collected from each patient at tracer equilibrium (40 hr after administration of K42, 50 μc; Na24, 30 μc; Br82, 20 μc): urine, which has a high chemical K: Na ratio, and serum, which has a low chemical K: Na ratio. The urine is counted in the beta-ray counter, which favors K42. The serum is counted in the gammaray counter, which favors Na24. To calculate the specific activities, equations are used which contain appropriate decay corrections, to permit calculation of the individual specific activities even though simultaneous counting of the samples in the two detectors is not required. The laboratory procedure is simple and straightforward, and the procedure gives results which are comparable in accuracy to methods which use only one isotope at a time. When counters of great sensitivity are employed, the procedure permits both small doses of radioisotope and long equilibration periods (40 hr). Total exchangeable chloride can be estimated at the same time by Br82 dilution. The calculation has been programed for a large digital computer. radioisotope separation; total exchangeable sodium; total exchangeable chloride; total exchangeable potassium Submitted on September 27, 1962
General and regional circulatory effects of synthetic eledoisin in man
Authors: Kontos Hermes A. , Shapiro William , Mauck H. Page , Patterson John L. 
Published: December 2017

The circulatory effects of intravenous infusions of synthetic eledoisin were studied in nine normal subjects. Infusions of 0.6 μg/min of eledoisin in eight experiments on eight subjects produced a transient fall in mean arterial blood pressure, tachycardia (average 14.3 beats/min), marked increase in cardiac index (average 3.4 liters/min m2), increase in stroke volume (average 58.3 ml/beat) and fall in systemic vascular resistance (average 6 mm Hg/liter min). Blood flow to hand and forearm increased (average increase in four experiments on four subjects 7.9 and 2.9 ml/min 100 ml tissue, respectively). More marked hypotension and tachycardia and a more pronounced increase in hand and forearm blood flows were observed during infusions of 2–5 μg/min of eledoisin in four experiments on four subjects. These results indicate that eledoisin is a powerful dilator of vessels in skin and skeletal muscle, and quite probably of vessels in other vascular areas. vasodilatation; effects on cardiac output; effects on hand blood flow; effects on forearm blood flow; hypotensive agent Submitted on July 1, 1963
Cold acclimatization of the fingers
Authors: Cavenagh A. J. M. 
Published: December 2017

Serial finger-flexion and V-test estimations were carried out on five subjects engaged in a high-altitude mountaineering expedition. Exposure to cold conditions was from 35 to 62 days. There was no evidence that local acclimatization to cold occurred. This contrasts with recent experiments in Canada and Antarctica where local acclimatization could be demonstrated within 6 weeks of exposure. Possible reasons for this discrepancy are discussed. finger-flexion test; V test for tactile discrimination; high-altitude cold exposure; high-altitude clothing Submitted on March 22, 1963
Thermistor system for measuring thermal gradients
Authors: Stoll Alice M. 
Published: December 2017

The system utilizes a thermistor bridge for the measurement of temperature differences of ±2.5 C to an accuracy of ±0.025 C. Calibrations are shown for a range of ambient temperatures from 22 to 45 C. Equations are derived for calculation of the temperature difference from the observed meter deflection and constants which depend upon the characteristics and matching of the thermistors. A series of such measurements provide the data for derivation of thermal gradients. skin temperature response measurement; skin simulation apparatus; measurement of small temperature differences; direct measurement of temperature difference; temperature-measuring instrumentation; thermistor bridge for temperature-difference measurement Submitted on March 19, 1963
Effects of sodium salicylate on physiological responses to work in heat
Authors: Jacobson Eugene D. , Bass David E. 
Published: December 2017

The hypothesis was tested that men given sodium salicylate would work in the heat at a lower level of temperature regulation. Healthy young volunteers were exposed to a standardized workload consisting of a 100-min walk at 3.5 mph on a level treadmill. Two ambient conditions were studied: a) simulated desert (120 F D.B., 80 F W.B.) and b) simulated jungle (92 F D.B., 87 F W.B.). Rectal temperature (Tr), skin temperature (Ts), sweat rate ( SR), and pulse rate ( PR) were measured in the subjects during work in the heat under three drug regimens: no drug (control), 0.6 g (low dose), and 7.8 g (high dose). It was found that sodium salicylate had no effect on Ts or PR compared with control; this finding applied to both doses in both hot environments. There was, however, a higher Tr and SR in men who received the high dose of the drug in the tropic environment and an increased SR in the desert climate. There was no decrease in Tr in the desert environment during salicylate administration. The results of this investigation do not confirm the original hypothesis; to the contrary, they suggest that high doses of sodium salicylate potentiates the hyperthermia of unacclimatized men working in the heat. body temperature regulation; exercise; simulated desert environment; simulated jungle environment; hyperthermia; rectal temperature, skin temperature, sweat rate, and pulse rate in hot environments; antipyretics Submitted on August 26, 1963
Components of alveolar-arterial O2 difference in normal man
Authors: Ayres Stephen M. , Criscitiello Antoinette , Grabovsky Evdokia 
Published: December 2017

The alveolar-arterial oxygen difference (A-aD) is believed due to true venous shunting, unequal distribution of alveolar ventilation (Va) to pulmonary capillary flow (Q), and diffusion limitations. Measurement of the A-aD was made at varying levels of alveolar oxygen tension in order to separate these three factors. The A-aD averaged 7.3, 15.2, and 37.1 mm Hg during the breathing of 14, 21, and 100% oxygen. The true venous shunt was 3.0 ± 1.9% of the systemic blood flow; unequal distribution of Va to Q resulted in an additional virtual shunt of 3.4 ± 2.6%. Breathing room air the diffusion component of the A-aD was negligible, true shunting accounted for 6.2 ± 4.0 mm Hg of the total A-aD. This created an A-aD of 9 and 0.6 mm for nitrogen and carbon dioxide, respectively. The method used could not distinguish the unequal Va/Q effect from the effect of unequal distribution of diffusion and perfusion. true veno-arterial shunt; alveolar ventilation-pulmonary capillary flow ratio (Va/Q); pulmonary membrane diffusion (D); virtual shunt (unequal Va/Q effect); distributional and diffusion components of A-aD; perfusion of nonventilated alveoli; venous admixture diffusing capacity; venoarterial shunting; alveolar ventilation/perfusion ratios; arterial oxygen tension; platinum electrode Submitted on May 22, 1963
Effects of compressibility of alveolar gas on dynamics and work of breathing
Authors: Jaeger M. J. , Otis A. B. 
Published: December 2017

Alveolar gas is compressed and expanded during every breathing cycle. The volume displacement measured at the mouth Vt (tidal volume) is therefore smaller than the volume displacement of the lung V't that may be measured with a body plethysmograph. Experimental data found in normal subjects and in patients with obstructive emphysema confirm the theoretical prediction that the ratio Vt/V't decreases with increasing airway resistance, breathing frequency, and lung volume. The effect was found to be very small in normal subjects breathing at different breathing rates; however, in patients with obstructive emphysema it may be appreciable, presumably because of the high airway resistance and the elevated functional residual capacity. With increasing altitude the effect is expected to be more pronounced. The mechanical work performed in compressing and expanding alveolar gas is not included in the conventional pressure-volume diagram, when intraesophageal pressure is plotted against the volume displacement measured at the mouth. This work may be determined, however, by recording the volume displacement of the lung simultaneously with tidal volume and intraesophageal pressure. Work related to compressibility is insignificant in most circumstances. In patients with obstructive emphysema, however, it becomes appreciable during hyperpnea. The compressibility of alveolar gas was also found to increase the negative work performed by respiratory muscles. volume displacement of the lung (V't); Vt/V't in obstructive emphysema; dynamic pressure-volume diagram; mechanical model - respiratory dynamics; ventilation; negative work of inspiratory muscles; ventilation and breathing work at high altitudes; mechanics of breathing Submitted on June 21, 1963
Pattern of ventilation in young adults
Authors: Bendixen Henrik H. , Smith Gene M. , Mead Jere 
Published: December 2017

The ventilatory pattern at rest was examined in 28 healthy human volunteers by recording pneumograph tracings for a 1-hr period. The mean respiratory frequency was 19/min in females, 16/min in males, but with considerable variation both within and among subjects. The mean inspiratory phase accounted for one-third of the respiratory cycle, but this fraction increased with increasing respiratory frequency and decreased when the frequency slowed. Tidal volumes varied greatly, and sighing (breaths larger than three times the average tidal volume) occurred at an average rate of 10/hr for females, 9/hr for males. The possible physiologic role of periodic deep breaths, or sighs, in providing reinflation of atelectatic areas is discussed. respiratory cycle at rest; respiratory frequency and tidal volumes; periodic deep breaths (sighing); inspiratory phase as related to expiratory phase; normal breathing; hyperinflation; respiration; rate of respiration; pneumographic tracings Submitted on November 8, 1962
Effect of octacosanol, wheat germ oil, and vitamin E on performance of swimming rats
Authors: Consolazio C. Frank , Matoush Le Roy O. , Nelson Richard A. , Isaac Gerhard J. , Hursh Laurence M. 
Published: December 2017

Two long-term studies (6 weeks) were performed to evaluate the effects of octacosanol, wheat germ oil, and vitamin E on the performance of swimming rats. In the first study the rats performed a single swim-to-exhaustion, 2 days a week, and in the second study a double swim-to-exhaustion, 2 days a week. Comparisons made during the study showed that the performance of rats receiving these substances did not differ significantly from that of control groups. These results are contrary to published data in the literature showing increases in performance with the various treatments. ergogenic drugs; exercise Submitted on May 8, 1963
Cardiac output during submaximal and maximal work
Authors: Åstrand Per-Olof , Cuddy T. Edward , Saltin Bengt , Stenberg Jesper 
Published: December 2017

In the present study oxygen uptake, cardiac output, stroke volume (dye-dilution technique) and oxygen content of arterial blood were determined in 11 women and 12 men, 20–31 years of age, at rest, and when performing submaximal and maximal work. At rest plasma volume (T-1824) and heart volume were determined. Sitting on the bicycle ergometer the stroke volume was 40–90% (mean 63%) of the maximum attained during exercise. Maximal stroke volume was essentially reached at a workload with an oxygen uptake of about 40% of the maximum and a heart rate about 110. No tendency to a decrease in stroke volume was noticed when maximal work was performed. The variation in stroke volume was ±4% during exercise in the range from 40 to 100% of the individual's aerobic work capacity. The maximal cardiac output was 18.5 liters/min for women and 24.1 liters for men. The correlation between heart volume on one side and maximal stroke volume and cardiac output on the other side was high and the expected one from the dimension of the individual. On submaximal as well as maximal exercise the women had a higher cardiac output per liter oxygen uptake than the men, and this can be explained by the lower concentration of hemoglobin in the women's blood. cardiac function during exercise; cardiac output stroke volume; cardiac output and arterial O2 content Submitted on October 3, 1963
Controlled atmosphere incubator for physiological studies involving the rare gases
Authors: Lawrie James A. , Schreiner Heinz R. , Cowley Clement W. 
Published: December 2017

The apparatus described is a small-scale sealed ecological system capable of confining the rare gases without significant loss. Biological test chambers suitable for a variety of biological specimens are illustrated. A “canned” pump provides gas circulation; a K2CO3 scrubber column removes CO2. Metabolized oxygen is replenished automatically from an O2 cylinder which is controlled by an ultrasensitive pressure switch. Provision is made for recording oxygen uptake. The equipment provides a constant temperature within 0.5 C over the range of 5–50 C and is capable of maintaining uninterrupted operation for periods of up to 14 days. small scale sealed ecological system; biological test chambers Submitted on February 4, 1963
Changes in respiration, heart rate, and systolic blood pressure in human sleep
Authors: Snyder Frederick , Hobson J. Allan , Morrison Donald F. , Goldfrank Frederick 
Published: December 2017

Twelve subjects were studied for a total of 30 nights of uninterrupted sleep by simultaneous recording of EEG, eye movements, heart rate, respiration, and systolic blood pressure. In agreement with previous reports, progressive decreases in heart and respiratory rates and an early fall followed by a sustained rise in systolic blood pressure were found to be consistent base-line trends. Superimposed upon these trends and coinciding with the regular recurrence of stage I rapid eye movements (REM) there were periodic changes in these three functions of two kinds: a) slight increases in average level and b) marked increases in minute-to-minute variability. The changes in average level of blood pressure and of both blood pressure and heart rate variability were more conspicuous during the later REM periods of the night. Alternative interpretations and possible medical implications of these findings are discussed. dreaming; sleep and EEG; eye movements and sleep Submitted on October 11, 1963
Rheology of human blood and hyperlipemia
Authors: Merrill E. W. , Gilliland E. R. , Margetts W. G. , Hatch F. T. 
Published: December 2017

By means of an electromagnetic coaxial cylinder viscometer, the blood from two hyperlipemic patients was studied near and at zero shear rate. The basic data: shear stress versus shear rate, were transformed to the respective square roots and plotted against each other. The resulting plots are linear, clearly defining at zero shear rate the yield shear stress and showing obedience to the Casson equation. The principal feature discovered from these data is that a) the yield shear stress reaches a maximum around 3 hr after ingestion of a fatty meal, this maximum being substantially greater than that of blood from the fasting subject, and b) the triglyceride concentration continues to rise to a maximum around 6 hr after ingestion, by which time the yield shear stress is approaching the normal value. A second feature, based on only one of the two subjects, is that the yield shear stress increases markedly as temperature of the blood decreases. Some comments are offered on the possible physiological relevance of the data and possible biophysical interpretations. low shear rheology; yield shear stress of lipemic blood; blood rheology-temperature relation; blood triglyceride concentration and yield shear stress Submitted on August 9, 1963
Rate of reaction of dithionite ion with oxygen in aqueous solution
Authors: Morello J. A. , Craw Margot R. , Constantine H. P. , Forster R. E. 
Published: December 2017

The rate of removal of oxygen from aqueous solution by sodium dithionite in 0.1 m sodium hydroxide was studied in a rapid-reaction apparatus using a membrane-covered polarographic cell to determine Po2 in the flowing liquid. The measurements were made at 37 C, so that the data would be applicable in studies of the kinetics of oxyhemoglobin in blood. The initial concentrations in the mixed reacting solution were between 8 x 10-5 m and 47.5 x 10-5 m for dithionite, and either 10 x 10-5 m or 47.8 x 10-5 m for O2. The reaction over the first 40 msec was found to be first order with respect to dithionite and zero order with respect to molecular oxygen. The initial rate constant was 42.5 ± sd 3.6 sec-1. oxygen reduction by dithionite; hemoglobin; deoxygenation rate; dithionite-oxygen reaction rate Submitted on June 17, 1963
Value of fluid and electrolyte supplements in subarctic survival situations
Authors: Rogers Terence A. , Setliff James A. 
Published: December 2017

After 48 hr on a standard diet indoors, 30 men were subjected to cold and starvation in the winter subarctic. During the fast, ten men got 230 mEq NaCl each, ten got 115 mEq NaCl plus 115 mEq NaHCO3, and the other ten got a placebo. Of each group of ten, five had water ad libitum and the other five each had a “forced” intake of 1,920 ml. In each electrolyte-supplemented group, those with the high water intake dehydrated to the same extent as those drinking ad libitum. Those getting NaCl or NaCl plus NaHCO3 lost a mean of about 1 kg less weight than those in the placebo groups. The NaHCO3 did not diminish the fasting acidosis. cold exposure; fasting; fluid balance; starvation Submitted on January 22, 1964