bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of muscle strength and endurance development on blood flow
Authors: Vanderhoof Ellen R. , Imig Charles J. , Hines H. M. 
Published: December 2017

Studies were carried out to investigate the effect of hand grip strength and/or endurance improvement on blood flow through the muscles involved. One group of subjects trained for strength development and another for endurance development throughout a 29-week period. At regular intervals blood flow was measured under resting conditions and also following three different test exercise stresses designed to test the functional capacity of the vascular bed. Subjects who participated in the strength training program made significant gains in strength but not in endurance, while those subjects who trained for endurance improved in both strength and endurance. Resting blood flow was not changed significantly as a result of either training program. Significant changes in the blood flow response to the test exercise stresses were noted; these changes were associated with endurance rather than strength improvement. Submitted on April 3, 1961
Regional blood flow and vascular resistance in response to oxytocin in the pregnant sheep and dog
Authors: Assali N. S. , Holm L. , Parker H. 
Published: December 2017

The effects of oxytocin on regional blood flow and regional vascular resistance were investigated in a group of pregnant ewes and bitches not in labor and in another group in early labor. Single injections or intravenous drip infusion did not change significantly arterial pressure, cardiac output, electrocardiogram, and renal, iliac, femoral, and carotid blood flows in any of the animals studied. The effects on the pregnant uterus were negligible before the onset of spontaneous labor. Only when the animal was in labor did oxytocin produce an increase in uterine contractions accompanied by a significant decrease in uterine blood flow. The data indicate that in the pregnant sheep and dog the circulatory action of oxytocin is limited to the pregnant uterus in labor and that the decrease in blood flow is probably due to an increase in intramural vascular resistance caused by the contracting myometrium around the uterine arterioles. Submitted on May 5, 1961
Anthropometric comparison of muscular and obese men
Authors: Taylor W. Leonard , Behnke Albert R. 
Published: December 2017

Body weight is frequently too gross as a reference base for physiologic parameters. Adequate techniques are available to measure such components as water and fat, but these procedures are time consuming and require special apparatus. The high correlation, however, between anthropometric circumferences, stature, and body weight makes possible a partition of weight into components, W( A) and W( B). In obese men it can be shown that the “trunk” W( A) component greatly exceeds the weight of W( B) referable chiefly to the extremities. In athletes, W( B) exceeds W( A). The average of W( A) and W( B) closely approximates body weight. From the anthropometric perimeters it is possible to calculate d values which can be used to construct a somatogram to provide quantitative representation of bodily configuration. The technique for procurement of the anthropometric data can be carried out on large numbers of individuals in minimal time and requires only a tape measure. Submitted on April 28, 1961
Metabolic cost of head-stand posture
Authors: Rao Shanker 
Published: December 2017

Metabolic cost to the human body of various postures has been assessed by many workers. The cost with the body in the topsy-turvy posture, or while “standing on the head,” has not been reported so far. Energy expenditure was calculated indirectly by estimating the amount of oxygen consumed while in a particular posture. A Benedict-type recording spirometer was used for this purpose. The subjects were six healthy medical students. The mean cost of standing on the head was determined to be 336 ml, or 1.62 kcal/min, and that of “suspension by the feet” to be 300 ml, or 1.44 kcal/min. The possible causes of increased consumption in relation to the “standing erect” posture are discussed. Submitted on May 26, 1961
Reproducibility of a glucose tolerance test
Authors: Acland J. D. , Clayton H. , Mitchell B. 
Published: December 2017

A statistical method is described for testing the significance of changes in the glucose tolerance of experimental subjects in different conditions. Statistically significant changes in glucose tolerance from day to day were observed in seven normal men who underwent glucose tolerance tests on 3 successive days. No statistically significant changes in glucose tolerance were found on the 2nd day after a glucose tolerance test in further experiments using five normal men. Possible physiological mechanisms by which the performance of a glucose test could cause alterations in glucose tolerance are discussed. Submitted on December 19, 1960
An electrical analyzer for carbon dioxide in respiratory gases
Authors: Bernstein Leon , Yoshimoto Chiyoshi 
Published: December 2017

The analyzer described was de signed for measuring the concentration of carbon dioxide in the bag of gas from which the subject rebreathes in the “rebreathing method” for estimating the tension of carbon dioxide in mixed venous blood. Its merits are that it is cheap, robust, simple to construct and to service, easy to operate, and accurate when used by untrained operators. (Medical students, unacquainted with the instrument, and working with written instructions only, obtained at their first attempt results accurate to within ±0.36% [sd] of carbon dioxide.) The instrument is suitable for use by nurse or physician at the bedside, and also for classes in experimental physiology. Some discussion is presented of the theoretical principles underlying the design of analyzers employing thermal conductivity cells. Submitted on July 13, 1961
Hemodynamic responses to oxygen breathing in man
Authors: Eggers G. W. N. , Paley H. W. , Leonard J. J. , Warren J. V. 
Published: December 2017

Hemodynamic responses to breathing 100% oxygen for an average of 30 min were studied in eight healthy male volunteers. Cardiac output and related determinations were performed with central injections of a radioactive indicator and calculated by the method of Stewart and Hamilton. Arterial blood gas analyses were performed in each phase of the study. Slight but statistically significant decreases in cardiac index and heart rate were observed during oxygen breathing. There was no change in the central blood volume, but a masked increase in pulmonary blood volume may have occurred. Statistically significant increases in peripheral vascular resistance, mean arterial pressure, and both systolic and diastolic arterial pressures occurred during oxygen breathing and persisted at least 40 min after oxygen was discontinued. Submitted on May 1, 1961
Estimation of effective renal plasma flow using I131-labeled Hippuran
Authors: Schlegel J. U. , Smith B. G. , O'Dell R. M. 
Published: December 2017

Values of PAH and Radio-Hippuran clearances, obtained simultaneously in 96 individual renal clearances for 16 patients, were plotted against each other and a regression line calculated which shows a linear relationship between the two substances. Knowing the value of the Radio-Hippuran clearance, by use of the regression line, the effective renal plasma flow in terms of PAH clearance can be estimated. This method of determination gives an accurate and less laborious measure of renal plasma flow than chemical determinations of PAH. Submitted on July 21, 1961
Myoglobin content and enzymatic activity of muscle and altitude adaptation
Authors: Reynafarje Baltazar 
Published: December 2017

Quantitative determinations of myoglobin were made in the sartorius muscle of healthy human subjects native to sea level and high altitude. The specific activities of the reduced form of diphosphopyridine nucleotide oxidase (DPNH-oxidase), DPNH- and the reduced form of triphosphopyridine nucleotide (TPNH)-cytochrome c reductases, transhydrogenase, and isocitric and lactic dehydrogenases were also examined. There was found a significantly higher myoglobin concentration in the muscle of the high-altitude native as compared with the sea-level resident. The enzyme systems DPNH-oxidase, TPNH-cytochrome c reductase, and transhydrogenase similarly showed a significantly higher activity in the altitude resident. It was concluded that the respiratory capacity of the muscle was apparently higher in the altitude native than in the sea-level one. The enhanced enzymatic activity was probably related to the higher pigment content of the skeletal muscle. Results on myoglobin determinations in several other muscles from certain sea-level patients are discussed. Submitted on July 24, 1961
Thermal influence of sunshine and clothing on men walking in humid heat
Authors: Craig F. N. , Cummings E. G. 
Published: December 2017

For two men walking on a treadmill and wearing two layers of permeable clothing, the same physiological strain measured by the rate of increase in mean body temperature could be produced a) next to a building outdoors in the sunshine with an average air temperature of 85 F and humidity of 20 mm Hg and b) indoors with the same humidity and an air temperature 10 F higher. Under these conditions, the underwear was mainly wet with sweat and the outer layer was mainly dry. In comparable indoor tests on a third subject, the temperature of the underwear approached equilibrium 1 or 2 F lower than the temperature of the skin at air temperatures of 85 and 115 F. The error in calculating clothing insulation introduced by assuming the clothing to be dry is determined by the size and direction of the temperature gradient between skin and air. Adding 10 F to the indoor air temperature does not duplicate all the effects of sunshine. Submitted on September 15, 1961
Postexercise hyperemia in trained and untrained subjects
Authors: Elsner Robert W. , Carlson Loren D. 
Published: December 2017

Physiological responses of athletes and nonathletes to treadmill exercise at 4 mph on a 10% grade for 5 min were compared. Some nonathletes were studied again after 4 weeks' physical training. Whereas the increase in oxygen consumption during exercise and the oxygen debt were similar in all groups, heart rate and blood flow in the leg increased less and returned to resting values more rapidly in athletes and in trained nonathletes than in untrained nonathletes. The time required for the return of blood flow to pre-exercise levels was greater than that necessary for the repayment of O2 debt. Circulatory changes involved in body temperature regulation during exercise had little effect on total leg blood flow. Experiments with a foot pedal exercise, with and without occlusion of circulation to the leg, suggest that athletes and trained nonathletes have greater blood flow in the muscles during exercise than do sedentary subjects. In the latter, the first few minutes after exercise without occlusion resembled recovery from exercise with occlusion, indicating that relative ischemia is normal in untrained subjects during moderate exercise. Submitted on October 19, 1961
Excretion trends in men undergoing deacclimatization to heat
Authors: Hale Henry B. , Ellis James P. , Balke Bruno , McNee Richard C. 
Published: December 2017

In an effort to characterize metabolic changes associated with heat deacclimatization under natural conditions, urinary determinations were made on 21 healthy men during the transition period from summer to fall. Two overnight urine specimens per subject per week were analyzed for sodium, potassium, phosphate, urea, uric acid, creatinine, and 17-hydroxycorticosteroids (17-OHCS). No trends were found for urine output, uric acid, urea, or sodium. Creatinine excretion rate and Na/K ratio fell as environmental temperature fell; potassium/creatinine ratio and potassium excretion rate increased. These four variables showed linear trends, but phosphate/creatinine ratio increased in a stepwise manner and urea/creatinine ratio increased only after temperature had fallen far below the summer level. Excretion of 17-OHCS (as rate or ratio) declined (two-stage shift). Subjects who did not exercise regularly showed upward shifting in phosphate excretion; nonexercising subjects as a group showed a cyclic tendency; and those who exercised daily showed essentially no change in phosphate excretion. This retention of one summer characteristic in the latter group is consonant with the literature on heat acclimatization in that it shows that physical fitness is a factor that delays heat deacclimatization. Submitted on May 25, 1961
Influence of altitude on heart and breathing rates in some Peruvian rodents
Authors: Morrison Peter , Elsner Robert 
Published: December 2017

Heart and breathing rates were measured at 0.1 and 4.5 km before, during, and after Nembutal anesthesia in Phyllotis darwini chilensis, P. d. rupestris, P. osilae, P. pictus, Akodon amoenus, A. berlepschii, A. jelskii, and A. boliviensis; in Mus musculus rates were measured at 3.9-4.5 km, and in P. d. limatus, M. musculus, and the white mouse at 0.1 km. None of the high-altitude mice and only the native Phyllotis (+25%) of the low-altitude mice showed a circulatory response to altitude. All the low-altitude mice but only Akodon (+22%) of the high-altitude mice showed a respiratory response to altitude. The native mountain species had higher resting heart and breathing rates than did the lowland forms. Submitted on October 25, 1961
Effect of lung inflation on bronchial dimensions in the dog
Authors: Marshall Robert 
Published: December 2017

Bronchial diameters and lengths were measured from bronchograms of separate lobes of dogs' lungs. The lobes were initially completely airless, and radiographs were taken at intrabronchial pressures of 10 and 20 cm H2O at stages during inflation of the lobe. The bronchi were dissected out, made airtight, and radiographs taken at different distending pressures. In the intact lobe the increase in bronchial diameter occurred mainly at volumes below the functional residual capacity of the lobe. At greater degrees of inflation the diameters increased only slightly and in some cases were reduced. The bronchial lengths increased throughout inflation. Full inflation of the lung caused approximately a 60% increase in bronchial diameter and a 40% increase in bronchial length. Change of intrabronchial pressure from 10 to 20 cm H2O caused only 4% increase in bronchial diameters in the inflated lobe. Comparison with the same diameters in the isolated bronchus showed that the lung parenchyma exerts traction on the bronchial wall but the traction bears no simple relationship to the inflation volume. Submitted on January 18, 1962
Circulatory and metabolic reactions to work in heat
Authors: Williams C. G. , Bredell G. A. G. , Wyndham C. H. , Strydom N. B. , Morrison J. F. , Peter J. , Fleming P. W. , Ward J. S. 
Published: December 2017

Oxygen consumptions were measured at various levels of work up to the individual's maximum. At submaximal work they were significantly lower in heat than in comfortable temperatures, but maximum oxygen intakes were not significantly different. In comfortable conditions cardiac output and A-V difference both contributed to rise in oxygen intake during submaximal work. At maximal effort increase in arteriovenous difference accounted for the ultimate rise in oxygen intake. Both heart rate and stroke volume contributed to increase in cardiac output up to 1.0 liters/min oxygen intake; above this heart rate was the sole factor. In heat the major change in hemodynamics was an increase in heart rate with an associated fall in stroke volume. Neither cardiac output nor arteriovenous difference was significantly altered from comfortable conditions. “Excess” lactate occurred at significantly lower levels of work in heat than in comfortable conditions. Working muscles were therefore relatively more anoxic in heat at submaximal work, and this accounted for lower oxygen intakes. At maximal work the degree of anoxia was the same in both temperature conditions. Submitted on August 22, 1961
Effect of x-irradiation on Na and K secretion by human parotid gland
Authors: Awwad H. K. , Habib Y. A. 
Published: December 2017

Experiments were carried out on 12 subjects to study the secretion of Na and K in the parotid saliva over secretory rates ranging from 0.06 to 2.2 ml/min. The possible effect of X-irradiation per se on such secretions was evaluated. Sodium concentration in saliva was linearly related to flow rate, whereas the potassium concentration was negatively correlated to salivary secretory rate. X-irradiation by itself did not influence the secretion of Na apart from its influence on flow rate. In the case of potassium, a significantly greater regression coefficient of potassium secretion per minute and flow rate was noted. This was associated with a significantly higher K/Na ratio in the saliva. Submitted on November 13, 1961
Adaptation of thermal pain in the skin
Authors: Greene Leon C. , Hardy James D. 
Published: December 2017

Cutaneous pain thresholds were determined on blackened skin of foreheads and forearms of human subjects over areas of 16 cm2 by recording skin temperature during exposure to thermal radiation for periods up to 50 min. Intensity of stimulus was controlled by the subject so that threshold pain was maintained throughout the exposure. After the initial period of adjustment by the subject, radiation intensity was generally maintained constant although skin temperature for the pain threshold decreased from 44.9 C to 43.8 C. By using an intensity as low as 22 mcal/cm2/sec, threshold pain was evoked in 29 min at a skin temperature of 42.2 C. In both groups, once pain had been established it did not disappear. It is inferred from these observations that thermal pain does not adapt for near-threshold stimulation in the period between onset of pain at 30 sec and termination of stimulation. Submitted on December 26, 1961
Stimulation of ventilation in emphysema by passively induced body motion
Authors: Froeb Herman F. 
Published: December 2017

The ventilatory stimulation arising from two different forms of passively induced body motion was chosen for study of 14 male emphysematous subjects with hypercapnia and impaired ventilatory response to carbon dioxide. Nine normal males served as controls. The object of the study was to determine whether the stimulus to ventilation from passive body motion was intact in diseased subjects and whether it could serve as a therapeutic tool by bringing about a reduction in blood carbon dioxide. The results revealed that the stimulus to ventilation was mild and comparable in both groups but was associated with two to three times more oxygen per extra liter of minute ventilation in the diseased subjects. There were no significant changes in the arterial blood gases. It was concluded that the stimulus to ventilation from passive body motion arises from weak muscle action and has no therapeutic application in emphysematous subjects as a means of lowering the PaCOCO2. Note: (With the Technical Assistance of Mabel Pearson, Roy Engstrom, Christa McReynolds, and Carol Kennedy) Submitted on March 5, 1962
Lateral inhibition of heat sensations on the skin
Authors: Békésy G. V. 
Published: December 2017

Many of the similarities that have been found between the organ of Corti, the eye, and the vibratory skin sensations are a consequence of lateral inhibition, and these similarities can be extended to heat sensations on the skin also. The chief differences lie in their numerical values. Analogues in heat sensations can be demonstrated for such phenomena as Mach bands and directional hearing, as well as the very pronounced sharpening effects of the spatial distribution of the sensation magnitude for traveling waves. Submitted on May 16, 1962
Coronary inflow and outflow measurement technique in dogs with thorax intact
Authors: Wcislo Vincent J. 
Published: December 2017

A new experimental approach for measurement of blood flow in the main coronary vessels is presented. Using specially devised extracorporeal circulatory loops with flowmeters and temporary cannulation of coronary arterial and venous orifices with large-bore, stiff catheters, the coronary blood flow was measured in dogs under almost normal conditions. In heparinized, large dogs under light pentobarbital anesthesia, coronary inflow was determined by directing the blood from the femoral artery through an arterial external loop and a Cybulski blood flowmeter to a one-channeled catheter, introduced via the common carotid artery into the aorta and temporarily wedged into the orifice of the left or right coronary artery. Simultaneously, the coronary sinus outflow was measured by inserting a two-channeled catheter into the sinusal orifice via the external jugular vein and right atrium. The catheter blocks this orifice and diverts the outflowing blood, first to the venous external loop, and then directs the return of the blood through a second flowmeter to the right atrium. Coronary flow and other cardiovascular functions were measured and optically recorded. The experiments did not necessitate subsequent sacrifice of the animals. Submitted on April 9, 1962
Neural factors underlying variations in electrical resistance of apparently nonsweating skin
Authors: Thomas P. E. , Kawahata Aikoh 
Published: December 2017

Many investigators have demonstrated that sympathetic sudomotor activity sufficient to cause visible sweating is accompanied by a decrease in electrical skin resistance (ESR). Furthermore, the reciprocal of resistance (conductance) was shown to be linearly related to the amount of perspiration and the number of visibly active sweat glands. The present study examines the relationship of ESR to sweat-gland activation under apparently nonsweating circumstances, and clarifies the significance of topographical differences in ESR observed in human studies conducted at moderate (nonsweating) temperatures; results also suggest a neural influence on insensible perspiration. Comparisons in adjacent high- and low-resistance areas were made of the sweat gland responses produced by intradermal injections of drugs that directly stimulate sweat glands. When just-threshold quantities of acetylcholine (ACh), pilocarpine, or epinephrine were used, the low-resistance areas always responded with more numerous activated glands. When both high- and low-resistance areas were injected with procaine approximately 10 min prior to ACh injection, activated sweat gland response was essentially similar in both areas. At moderate temperatures, sweat glands evidently receive sudomotor impulses at a rate that does not produce visible sweating, but does increase transcutaneous water transfer and electrolyte conductance Submitted on February 21, 1961