bluuebunny/crossref_metadata_2025 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
Influence of temperature on olfactory sensitivity
Authors: Stone Herbert
Published: December 2017

Page 746: Stone, Herbert, “Influence of temperature on olfactory sensitivity.” The footnote to Table 2 on page 748 should read: * x 10-4 mg/liter air.
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
Effect of negative-pressure breathing on lung mechanics and venous admixture
Authors: Velasquez Tulio , Farhi Leon E.
Published: December 2017

Anesthetized dogs in the supine position show a spontaneous decrease in total respiratory compliance and an increase in venous admixture to the pulmonary circulation. Both these changes can be increased by negative-pressure breathing and reversed by positive-pressure breathing. If the changes in total respiratory compliance are due only to changes in lung compliance and these in turn result directly from the closure of alveoli, the relationship between compliance and inspiratory and expiratory pressure allows one to determine the scatter of opening and closing pressures in the alveoli. The venous admixture measures blood flow through collapsed alveoli, and its relationship to the negative pressure applied indicates the perfusion of the alveoli collapsing with each increment in negative pressure. By studying simultaneously changes in compliance and venous admixture, and using two basic assumptions, the dog's lungs can be described as a system composed of some elements receiving nearly 50% of the ventilation and 20% of the perfusion, relatively unstable mechanically, and having a very high Va/ Q ratio, while the remaining air spaces receive the same ventilation, but 80% of the perfusion.

lung compliance; atelectasis; ventilation-perfusion ratio

Submitted on October 28, 1963
Relative contributions of the rib cage and the diaphragm to ventilation in man
Authors: Bergofsky Edward H.
Published: December 2017

A plethysmographic method was used to partition the tidal volume into two components: that due to rib-cage expansion and that due to diaphragmatic descent. In 15 normal subjects, one-third of the tidal volume was effected by diaphragmatic descent during various situations, i.e., at rest, voluntary respiratory maneuvers, and breathing special gas mixtures. This technic was combined with measurements of intra-abdominal pressure changes in order to measure the extrapulmonary work done by the diaphragm. For ordinary breathing, this work was found to equal the total extrapulmonary work of breathing (rib cage plus diaphragm) measured by passive ventilation in a body respirator, indicating that the rib cage requires no work to move itself until tidal volumes greater than 1 liter are reached.

thorax; work of breathing

Submitted on October 24, 1963
Integrated muscle chamber-transducer system
Authors: Katzung Bert
Published: December 2017

The design and construction of a muscle chamber and isometric transducer system suitable for many types of in vitro studies of muscle is described. The unit can be constructed without special machine tools from easily available materials. It provides a high degree of versatility and is particularly suitable for simultaneous mechanical and electrical recording.

isometric transducer system

Submitted on December 2, 1963
A mechanism for positioning devices inside large blood vessels
Authors: Evert J. F. , Fingerson L. M.
Published: December 2017

In order to facilitate the positioning of various velocity sensing devices in arteries, several types of probe configurations and external controllers were developed. The most successful of these is small enough to use in arteries of 3@#X2013;4 mm or larger. It utilizes three legs placed around the end of a catheter-like probe. At the end of this probe the velocity sensor is placed, generally a hot film anemometer in this study. By the manipulation of the external controller the legs, which are mechanically connected to the controller, may be moved relative to one another so that the probe end will visit any point over a given cross section of artery. The controller may be calibrated in order to determine any probe position to @#X00b1;10% and also to measure the vessel inner diameter at the point of investigation. Brief constructional details of both probe tip and controller are given.

positioning, catheter in vivo; velocity sensor positioning, blood flow; cross section exploring of vessels; diameter measuring of vessels; vessel cross section positioning; catheter positioning in vivo

Submitted on January 27, 1964
Validity of phonoarteriographic blood pressures during rest and exercise
Authors: Mastropaolo Joseph A. , Stamler Jeremiah , Berkson David M. , Wessel Hans U. , Jackson Walter E.
Published: December 2017

A modification of the auscultatory blood pressure method, the phonoarteriogram, was developed. The innovated method essentially is a modified amplifying stethoscope. The pressure in the cuff is recorded from a pressure transducer, and the systolic and diastolic criteria are recorded from a microphone. The phonoarteriogram gives the advantages of a permanent record, includes pulse rate and pulse sound data, is not affected by hearing acuity, permits determinations often denied using auscultation in high ambient noise and exercise conditions, and eliminates observer bias. Three hundred and forty resting determinations and 218 exercise determinations on 60 subjects indicated good agreement between the phonoarteriogram and auscultation. In 50 systolic and diastolic intra-arterial determinations before compression of the cuff, during rest and exercise from one subject, the phonoarteriogram was as valid as auscultation. In 56 intra-arterial determinations during deflation of the cuff, i.e., simultaneous with the indirect measurements, during rest and exercise from a second subject, the phonoarteriogram was less fallible than auscultation, particularly during exercise. Phonoarteriograms are valid, reliable, and objective blood pressure record

blood pressure determination; auscultatory blood pressure; intra-arterial blood pressure; physical fitness testing; ausculation; effort or physical effort; exercise; exertion; fatigue; methods, physiological; instrumentation; pulse; work

Submitted on January 16, 1964
Modifications of neural output signals by muscles: a frequency response study
Authors: Partridge Lloyd D.
Published: December 2017

Computer-generated stimulus patterns were used to study the response of cat skeletal muscle to nerve signals of changing impulse rates. Isometric tension responses were recorded. This method of testing demonstrated that muscle introduces alterations into dynamic nerve signals which are not obvious when tested with only a single pulse or even with uniform tetanic trains of stimuli. Within the range of physiological response characteristics, muscle introduces large lags in the response. The importance of such lags in the stretch reflex and other feedback systems is emphasized. Muscle also shows less isometric response amplitude for rapid cyclic inputs than for inputs of nerve impulses which change slowly in rate. Graphs are presented which illustrate the differences in amplitude and lag effects introduced by muscle when dealing with pulse rate signals varying at different cyclic frequencies.

feedback analysis; pulse rate modulation; lag; reflex; isometric response; muscle dynamics; movement

Submitted on January 9, 1964
Distribution of ventilation in normal subjects from 7 to 45 years of age
Authors: Orzalesi M. M. , Hart M. C. , Cook C. D.
Published: December 2017

Distribution of ventilation was investigated in 57 normal subjects of both sexes ranging in age from 7 to 45 years using the nitrogen washout method. Normal values for nitrogen clearance delay and the lung clearance index are presented for children and adults. No significant sex- or age-dependent difference was found in either of these parameters. The present data are compared with those in the literature.

nitrogen washout; respiration in children and adults; distribution of inspired gas in children and adults; gas distribution

Submitted on April 13, 1964
Body oxygen consumption and pulmonary ventilation in obese subjects
Authors: White Robert I. , Alexander James K.
Published: December 2017

Postabsorptive body oxygen consumption (Vo2) and pulmonary minute ventilation (Ve) were measured 164 times in 109 very obese subjects at rest. A statistically significant relationship was found between Vo2 and total body weight. The correlation coefficients for the relationships between Ve and total body weight and Ve and body surface area were less significant. The mean calculated basal metabolic rate was within normal limits. The mean values for Vo2 in the obese subjects were considerably higher than those predicted at ideal weight, while the mean values for oxygen consumption per kilogram body weight were lower than those reported in normal subjects. The mean percentage increase in oxygen consumption per kilogram excess weight (ΔVo2/Δ kg) approached the value for percentage of cell mass in excess weight, suggesting that ΔVo2/Δ kg may be a function of the increment in cell mass with obesity. Similarly, since basal metabolic rate remained unchanged, proportionate increments in body surface area and cell mass appeared to occur with the development of obesity.

obesity tissue, oxygen consumption

Submitted on April 3, 1964
Hemodynamic responses to controlled 100% oxygen breathing in emphysema
Authors: Holt John H. , Branscomb Ben V.
Published: December 2017

Cardiopulmonary hemodynamic responses to breathing 100% oxygen for 20 min were studied in 13 patients with moderate to severe chronic obstructive emphysema under conditions of controlled ventilation. A technique for regulating the level of ventilation in the unanesthetized subject is described. Cardiac output was measured by the indicator-dilution method. Arterial blood gas analysis and pH were performed in each phase of the study. A slight but statistically significant decrease in cardiac index occurred. There was a highly significant reduction in pulmonary arterial pressure and pulmonary vascular resistance. No change in heart rate, pulmonary wedge pressure, or aortic pressure occurred. It is concluded that oxygen breathing caused a release, in part at least, of a pulmonary vasoconstrictive element in these patients.

pulmonary circulation; oxygen in pulmonary hypertension; hypoxia and pulmonary vasoconstriction; controlled ventilation during oxygen inhalation

Submitted on May 27, 1964
Intra-arterial blood pressure during exercise with different muscle groups
Authors: A°strand Per-olof , Ekblom Björn , Messin Roger , Saltin Bengt , Stenberg Jesper
Published: December 2017

In 13 subjects intra-arterial blood pressure, heart rate, blood lactate, oxygen consumption, and pulmonary ventilation were respectively measured during submaximal and maximal arm and leg exercise. Blood pressure usually increased linearly with the oxygen uptake, this increase being significantly more pronounced for arm than leg work. The site of the catheter, mostly the femoral artery, can partly account for the difference, recorded blood pressure being constantly higher in the resting limb. Nevertheless, simultaneously recorded pressures in arm and leg give significantly higher values during cranking. Larger increases in peripheral vascular resistance in the resting extremities during arm work as well as the important static work produced by cranking are possible explanations for this difference. This fact might have clinical interest.

differences between arm and leg work; catheter position when measuring blood pressures; lactate production in small and large muscle groups

Submitted on June 15, 1964
Energy metabolism in hypnotic trance and sleep
Authors: Jana Hrishikesh
Published: December 2017

The energy metabolism of 14 healthy males was studied before and during a hypnotic trance in the basal state. Metabolic rates during the basal waking, the basal hypnotic trance and the basal sleep were also determined in three subjects for 3 consecutive days, respectively. It was observed that a hypnotic trance does not significantly influence the metabolic rates in a basal condition while natural sleep lowers the basal metabolic rates by 8.73%.

hypnosis; oxygen consumption; carbon dioxide; elimination; respiratory quotient

Submitted on April 7, 1964
Demonstration of bile stasis in the mouse by a direct and an indirect method
Authors: Plaa Gabriel L. , Becker Bernard A.
Published: December 2017

Cannulation of the common bile duct of the mouse has been effected. Bile flow rates and bile pigment concentrations have been determined in these preparations. These values are lower than comparable values in bile duct-cannulated rats. An indirect test for detection of bile flow in the mouse, using injected fluorescein as an indicator, has been devised. Using all-or-none criteria, results obtained using the indirect technique correlate well with those obtained by the direct (cannulation) method. The use of the indirect test in conjunction with liver function tests, e.g., Bromsulphalein (BSP) retention, is recommended as a means of elucidating causes of liver dysfunction. By this means, a difference has been demonstrated between two hepatotoxic agents which effect BSP retention in the mouse: carbon tetrachloride and alpha-naphthylisothiocyanate (ANIT). The latter agent interferes with BSP excretion as shown by the indirect bile flow test; carbon tetrachloride does not cause blockage of bile flow.

bile flow; alpha-naphthylisothiocyanate; CCl4; cannulation of bile duct in mice; fluorescein; measure of bile flow in mice; sulfobromophthalein; bile pigment concentration in mice

Submitted on September 10, 1964
Thermal dilution: instrumentation with thermistors
Authors: James Gordon W. , Paul Milton H. , Wessel Hans U.
Published: December 2017

Based on the steady-state small-signal equivalent circuit parameters for a self-heated thermistor, the relationship of flow versus temperature sensitivity is found to be linear with the power dissipated in the thermistor. For the thermistors considered (YSI 520 and 512 series) flow sensitivity is negligible at power inputs below .01 mw. This power applied to a thermistor incorporated into a balanced Wheatstone bridge provides an output signal of approximately 150 μv for a .1 C temperature change. Amplifier requirements for thermal dilution are: gain of 104, a frequency response of 25 cycle/sec or greater, and a peak noise referred to input of less than 2 μv. A calibration procedure using a fixed resistance bridge unbalance and calculations from measured thermistor parameters is discussed. The procedure is independent of changes in amplifier and recorder gain, or changes in bridge voltage and ambient temperature. The effect of thermistor aging on the procedure is considered and found to be quite small. A bridge circuit incorporating variable bridge voltage is described and the application of the variable bridge voltage to the in vivo estimation of the thermistor dissipation constant and flow effects are discussed. Intravascular temperature measurements in man and in the anesthetized dog indicate that changes in thermistor resistance periodic with pulse are primarily the result of intermittent contact of the thermistor with the vessel wall, and due to changes in both temperature and dissipation constant.

temperature measurement; cardiac output

Submitted on June 12, 1964
Design and performance characteristics of a respiratory valve for the dog
Authors: Zechman Fred W. , Orr Thomas B. , Brooks John
Published: December 2017

Working drawings and performance characteristics are presented for a small respiratory valve. The valve has the following advantages: light weight (17 g), low flow resistance (0.6 cm H2O at 0.5 liter/sec), and a small dead space volume (8.5 ml).

respiratory valve design; small animal respiratory valve

Submitted on July 20, 1964
An electro-optical meniscus-sensing system for a pressurized flush bottle
Authors: Benson Robert W. , Schiebler Gerold L. , Krovetz L. Jerome , Sutterer William F.
Published: December 2017

A pressurized flush bottle system is used in some laboratories to ensure patency of indwelling catheters and needles. Some method must be utilized to monitor the fluid level in the bottle since complete emptying of the fluid would allow air under pressure to pass into the circulatory system. An electro-optical device is described which will sense a predetermined level of saline. A light source is mounted in a bottle holder assembly almost opposite and slightly below a photoresistor. At any level of fluid, some light from the exciting lamp is reflected from the meniscus causing a shadow immediately above the fluid level. When the meniscus falls below the photocell level, the decrease in light intensity increases photocell resistance which causes the transistorized circuit to activate audio and visual warning devices.

electro-optical warning device; exciting lamp; fluid transistorized circuit

Submitted on October 26, 1964
Interrelation between lung volume, arterial CO2 tension, and respiratory activity
Authors: Woldring Sabbo
Published: December 2017

In anesthetized cats with open thorax the activity of the respiratory muscles (diaphragm and abdominal muscles) is studied as a function of lung volume and arterial CO2 tension. It is shown that the sensitivity of the inspiratory muscles to a given change in lung volume (V) (Hering-Breuer reflex) varies with the arterial pCO2 level, and conversely, that the CO2 sensitivity of the inspiratory motor system is dependent upon the volume of the lungs. The relations are fairly linear and can be expressed by the equation: M — M0 = K (pa CO2 — p0) (V0 — V), in which M represents inspiratory motor activity and M0, p0, and V0 and K are constants. The activity of the expiratory muscles is not dependent on CO2.

regulation of respiration; Hering-Breuer reflex; electromyography of respiratory muscles

Submitted on September 24, 1964
A method for measuring deviations from equilibrium of the glucose anomers in blood
Authors: Hill John B.
Published: December 2017

A method for detecting deviations from equilibrium values of β-d-glucose has been developed. This method is dependent upon the specificity of glucose-oxidase for β-d-glucose and the catalytic effect of hydroxyl ions on mutarotation. The method has been used to monitor the blood stream of anesthetized normal dogs and dogs given epinephrine, glucagon, or insulin. It has also been used with alloxan-diabetic dogs. Since the method will detect deviations from equilibrium when agr- or β-d-glucose infusions are given and since in the above situations no impressive deviations were seen, it has been concluded that in the anesthetized dog the glucose is at or very near equilibrium and that glucagon and epinephrine do not alter the equilibrium.

monitoring blood glucose; epinephrine on glucose anomers; glucagon on glucose anomers; insulin on glucose anomers

Submitted on August 24, 1964
Convenient apparatus for recording contractions of isolated heart muscle
Authors: Blinks John R.
Published: December 2017

A simple and convenient apparatus for physiological or pharmacological experiments on preparations of isolated heart muscle is described. Provision is made for recording independently from two preparations mounted in the same bath. Electrodes for stimulation or recording are incorporated in the clamps that hold the tissue. The construction ensures the maintenance of a high oxygen tension at the surface of the tissue without the mechanical artifacts that result from bubbling oxygen directly past it.

papillary muscle; isolated organ bath; isolated atria; double muscle preparation; circulating salt solution; stimulating electrodes; concentration-effect curves; inotropic and chronotropic effects; oxygenation

Submitted on November 5, 1964
Polarographic determination of oxygen content and capacity in a single blood sample
Authors: Maio Domenic A. , Neville James R.
Published: December 2017

A polarographic method was described in an earlier report which permits the accurate, rapid determination of oxygen content in small samples of blood. As with the Van Slyke technic, total oxygen capacity was formerly estimated by a separate determination of the oxygen content after complete saturation with oxygen of another portion of the blood sample. Further experience with the polarographic method has revealed the feasibility of estimating both content and capacity in a single blood sample. The capacity estimate is made possible by the polarographic observation of the quantity of potassium ferricyanide required to convert ferrohemoglobin to ferrihemoglobin. The measurement of oxygen content is performed, as previously described, by the polarographically determined increase in physically dissolved oxygen caused by the release of bound oxygen. By this means, one avoids sampling and random errors inherent in the use of two separate determinations. The method requires only a brief time for performance and ordinary technical proficiency. It is also simple in application.

polarographic dropping mercury electrode; oxygen tension; digitonin; potassium ferricyanide; ferrohemoglobin; ferrihemoglobin

Submitted on June 24, 1964
Renal function in high-altitude natives and in natives with chronic mountain sickness
Authors: Lozano Rodolfo , C. Carlos Monge
Published: December 2017

When compared with sea-level residents, the healthy natives living at an altitude of 4,540 m show a 12% reduction in the glomerular filtration rate, a 37% reduction in effective renal plasma flow, a 12% reduction in effective renal blood flow, and an increase of 39% in the filtration fraction. The corresponding values in patients with chronic mountain sickness living at 4,300 m above sea level are: glomerular filtration rate, 32% reduction; effective renal plasma flow, 57% reduction; effective renal blood flow, 9% increase; and filtration fraction, 56% increase. The mean hematocrit values of the healthy and sick natives investigated were 59 and 79%, respectively. The possible relationships between cardiac output, hematocrit values, and renal hemodynamics are discussed.

altitude stress; blood flow, kidney; glomerular filtration

Submitted on October 5, 1964
Microphotoelectric plethysmography using a rabbit ear chamber
Authors: Asano Makishige , Yoshida Keiichi , Tatai Kichinosuke
Published: December 2017

The total and segmental microphotoelectric plethysmographs (—m; MPPG) were developed by using CdS photoconductive cells and rabbit ear chambers. The former were obtained from a whole micro-circulatory unit and the latter from segmental vessels in the microcirculation of which images were projected on a focusing glass. Both record the dynamic behaviors of the microcirculation continuously and quantitatively, and permit microscopic observations. The total and segmental MPPGs reflect various fluctuations of vasomotion and of blood flow in the microcirculation. In the microcirculatory blood flow, rhythmic fluctuations of 4–8, 8–12, and 0.5 or fewer counts/min were distinctly noticed in addition to the basic rhythm of 1–3 counts/min.

agrR wave; ßbeta;R wave; ggrR wave; omegaR wave; rhythmic fluctuation in the microcirculation

Submitted on April 29, 1964
Phase-sensitive detector-type electromagnetic flowmeter
Authors: Guha Sujoy K. , Richardson Alfred W.
Published: December 2017

An improved 60 cycles/sec sine wave electromagnetic flowmeter has been developed. By special construction of the pickup cannula and phase-sensitive demodulation, the conventional “balancing” procedure has been eliminated. Thus the operational technique is simple, and the flowmeter does not need readjustment between use. Both forward and backward flows can be measured with less than 3% error. The frequency response as determined by the use of a suppressed carrier modulated signal was 0–30 cycles/ sec without loss.

blood flow; 60 cycles/sec sine wave; suppressed carrier test

Submitted on October 26, 1964
Intrapulmonary exchange of the stable isotope 18O2 injected intravenously in man
Authors: Lassen N. A. , Fritts H. W. , Caldwell P. R. B. , Giuntini C. , Dansgaard W. , Cournand A.
Published: December 2017

The stable isotope 18O2 was used to study the exchange of oxygen molecules between pulmonary capillary blood and alveolar gas in 16 patients with either normal lungs or limited lung disease. The technique entailed combining gaseous 18O2 with blood, then mixing the blood anaerobically with saline containing T-1824 dye and 85Kr in solution. After the combination of tracers had been injected into a vein, arterial blood was collected during the first passage of the indicators through the central circulation. Recoveries of the tracer gases were expressed as percentages of the amounts that would have been found had no loss from the blood stream occurred. The recoveries of 18O2 were related to the oxygen concentration in the inspired gas, and averaged 55, 40, and 11% at inspired concentrations of 14, 21, and 65%, respectively. The recovery of 85Kr was about 2%, and was independent of the inspired oxygen concentration. These results were compared to those predicted in a theoretical model, and found to agree satisfactorily

intrapulmonary gas exchange; intrapulmonary oxygen exchange

Submitted on October 2, 1964