bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early effect of moderate altitude stress on plasma potassium in the dog
Authors: Gold Armand J. , Barry Jeanne Q. , Ferguson Frederick P. 
Published: December 2017

Exposure of dogs to a simulated altitude of 30,000 feet for 30 minutes resulted in marked respiratory alkalosis and hypokalemia. The data failed to demonstrate, however, the appearance of the early transient hyperkalemic response which has been observed in human beings in the early moments of hyperventilation. Blood pH rose from an initial level of 7.46 to 7.71 after 3 minutes of exposure to altitude. At 30 minutes it had declined slightly from this maximal level to 7.63, suggesting the development of partial compensation to respiratory alkalosis. The results also indicated a temporal potassium-glucose relationship, potassium decreasing and glucose increasing simultaneously during exposure to altitude. Submitted on July 13, 1959
Pulmonary vascular resistance and vascular transmural gradient
Authors: Lloyd Thomas C. , Wright George W. 
Published: December 2017

Perfusion studies were made on vascular beds of isolated dog lungs. Submerged, gas-free, fluid-distended lobes served for studies of resistance versus transmural pressure in a technique that abolished gravitational effects. Air-distended lobes with varying degrees of pulmonary edema were used to display the transmural gradient differences produced by height, and the effect alveolar fluid has on the apparent transmural gradient. Results indicate that the vascular bed behaves as a compliant tube of a limited maximal radius to which it may be distended while still in the normal pressure range. Vasopressors influence the wall distensibility and thus only the lower pressure portion of a pressure-flow curve. Flow continues through lobes distended at higher than arterial pressures with air. Progressive disappearance of this phenomenon as intra-alveolar fluid collects suggests that the effective transmural gradient differs from the vascular-alveolar gradient and is in part a function of alveolar surface tension. Submitted on October 16, 1959
Effect of acceleration on blood creatine, creatinine and inorganic phosphorus in man
Authors: Slonim Arnold R. 
Published: December 2017

Ten healthy male subjects were centrifuged front to back at 6 g for 3 min., with head and trunk inclined 25 degrees forward in the direction of acceleration. Average control values of blood creatine, creatinine and inorganic phosphorus were almost identical to those found immediately after exposure to the acceleration. Relatively large differences (test minus control) in some individuals were not significant. Acceleration of the magnitude and/or duration used in this study does not appear to be comparable to the effects of vigorous exercise on the phosphocreatine system of man. Submitted on July 23, 1959
Mechanical efficiency of breathing
Authors: Milic-Emili G. , Petit J. M. 
Published: December 2017

Simultaneous measurements of mechanical work and energy cost of breathing were performed on four normal subjects with ventilation increased by adding dead space. Mechanical work was obtained from simultaneous records of endoesophageal pressure and tidal volume. The associated energy cost was estimated by measuring oxygen consumption of respiratory muscles by means of a closed-circuit spirometer. In all subjects studied and over the range of ventilations involved (ca. 30–110 l/min.), the mechanical efficiency of breathing was found to be in the order of 0.19–0.25. Submitted on July 6, 1959
Effect of body composition and weight gain on performance in the adult dog
Authors: Young D. R. 
Published: December 2017

The effect of overfeeding and variations in body composition on resting metabolism and work performance has been examined in the adult dog. At rest, the mean O2 uptake was 85.5 cc/min. and the R.Q. was .65. These were not substantially altered by 20% gain in weight associated with variations of 12%–20% in body fat content. Work performance was tested during a 50-min. period of treadmill running at a fixed work intensity of 202.9 kg-m/min. Oxygen uptake, work and recovery pulse rates were constant. However, the respiratory quotient increased from .81 to .95 and water loss during work increased from 1.16 cc/Cal. to 1.84 cc/Cal. with gain in weight and adiposity. It is concluded that the most important effect of gain in weight is to promote increased water loss during constant steady-state work. Submitted on December 11, 1959
Electric response in the mammary gland
Authors: Forbes Alexander , Neyland Marjorie , Fox Sally 
Published: December 2017

Our previous investigations have indicated that ‘let-down’ sensation in the mammary gland in nursing, or on injection of Pituitrin, is accompanied by slow electric response. This was believed to emanate from secreting-gland cells or from contractile myoepithelial cells. Indirect control indicated that sweat-gland activity, related to emotional reaction, played little part in electric response recorded from the breast. We have controlled this question of sweat-gland participation in observed response by recording simultaneously from the palm of the hand and from the areola in a non-lactating subject. It was found that spoken words evoking emotional reactions were accompanied by large electric responses from the palm, but from the areola there were either no responses or very small inverse deflections, presumably due to sweat glands in the skin of the thorax. Observations on lactating subjects showed that during nursing occasional deflections in the palmar record resembled those evoked in word tests, but in no case did the palmar record show a slow response synchronized with that recorded from the areola during the letdown. From these observations we conclude that sweat-gland reactions play little part in the characteristic let-down electric response led off from the areola. This must arise from a different source, presumably either the myoepithelial cells, the secreting cells, or both. Submitted on January 14, 1960
Breathing in brief exercise
Authors: Craig F. N. , Cummings E. G. 
Published: December 2017

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960
Electrodiagnosis of vitamin E-deficient and denervated skeletal muscle of rabbits
Authors: Fudema John J. , Oester Yvo T. , Fizzell James A. , Gatz Arthur J. 
Published: December 2017

Nutritional muscular dystrophy was produced in rabbits maintained on a vitamin E-deficient diet. Electrodiagnostic data collected from the anterior tibial muscles of these animals were compared with data from control animals on the same diet supplemented with vitamin E, and animals on the control diet which had unilateral surgical denervation of one anterior tibial muscle. Strength-duration curves of muscles developing dystrophy demonstrated a pronounced upward trend and were complex, containing two segments with a discontinuity at their juncture. This upward trend and the discontinuity of the strength-duration curves suggest the presence of denervation, for these are characteristically found in muscle denervated by partial or complete section of the motor nerve. Chronaxie, repetitive stimulation and galvanic tetanus ratio values of dystrophic muscle in the late stages were found to be comparable to the observations of the same criteria in the early stages of denervated muscle. No change in threshold of vitamin E-deficient muscle to faradic stimulation was found. In denervated muscle, response to faradic stimulation persisted, though with increased threshold at the end of a 60-day observation period. Submitted on December 9, 1959
Graphic visualization of the relations of metabolic fuels:heat:O2:CO2:H2O:urine N
Authors: MacHattie Lorne A. 
Published: December 2017

The quantitative relations among the various measured and calculated variables of metabolism can be described much more clearly by graphs than in words or tables. A system of graphing is presented whereby these relations can be shown on any of 105 different graphs in terms of straight lines. The metabolic variables treated are: carbohydrate, fat, protein (or urinary nitrogen), heat, O2, CO2 and metabolic water. Since the values of any three of these are sufficient to define the metabolic situation, they define on the graph a point which stands for that situation, and from which the relative values of all the other variables can be read off. Theoretical principles of the system are given whereby the general layout of any of the 105 graphs can be easily found. The graph on axes of O2 /heat vs. CO2/heat is selected for development and is used to show the relations of the metabolic variables, not only for the case of simple catabolism of fuel mixtures, but also for cases involving fuel syntheses, ketosis, lactic acid production, and measurement errors due to unsteady states. Submitted on July 8, 1959
Heat output in the cold from hands of Arctic fishermen
Authors: Hellström B. , Andersen K. Lange 
Published: December 2017

The heat output from the hands of Arctic fishermen was studied by water calorimetry, using an initial water-bath temperature of 4°C. The fishermen were compared with a group of young men not habituated to work in the cold. The subjects were investigated when comfortably warm and when kept in heat debt by being chilled. The total heat output from the hand during the 30 minutes of calorimetry ranged from 1907 cal/100 ml hand tissue/min. (cold room) to 4886 cal/100 ml hand tissue (warm room). There was found no significant difference of the mean heat output between the two groups, neither when they were in general heat balance, nor when in heat debt. One subject who developed cold urticaria showed a considerably higher heat output than any of the other persons investigated. The results do not agree with the view that men habituated to working in the cold with their hands show an increased blood flow in the cold when studied under environmental temperatures low enough to produce a general vasoconstriction. Submitted on March 21, 1960
Effects of ventilatory pattern and body position on lung volume in dogs
Authors: Kilburn Kaye H. , McDonald Jerry , Piccinni Frank P. 
Published: December 2017

The functional residual capacity (FRC) of paralyzed pump-ventilated dogs was measured by open-circuit helium dilution at various rates and volumes of ventilation and the FRC's of spontaneously ventilated dogs were compared after changes in body position. When tidal volume was constant, increases in rate and minute volume increased FRC. The FRC tended to increase with larger tidal volumes when minute ventilation was constant. An inclination of 30 degrees increased FRC 23.8% (mean for 41 dogs) above the FRC measured in the horizontal position, whereas a declination of 30 degrees decreased FRC by 65.8% (mean for 8 dogs). It is suggested that larger tidal or minute volumes open pulmonary units which are closed by surface tension forces when the volume or duration of inflation is less. Tilting head-up or head-down changes the position of the diaphragm and the abdominal contents in the thoracic ‘cylinder’ to accommodate more or less gas volume in the thorax. Submitted on February 29, 1960
Static pressure-volume characteristics of lungs in normal males
Authors: Permutt Solbert , Martin H. B. 
Published: December 2017

The static pressure-volume characteristics of the lungs were determined in 28 normal males between the ages of 21 and 76 years. Transpulmonary pressures were measured in relation to absolute lung volumes throughout the entire range of the vital capacity, both on inspiration and expiration. There was an increase in residual volume and a decrease in vital capacity, but no change in the slope or position of the pressure-volume curve with advancing age. It appeared that the older subjects were unable to change transpulmonary pressure between residual volume and total lung capacity to the same extent as the younger subjects. The results suggest that with advancing age there is little change in the intrinsic static pressure-volume characteristics of the lungs themselves, and that all of the significant changes with age are more likely due to changes in either the compliance or muscle power of the thorax. Submitted on December 24, 1959
Rate of flow of parotid secretion during constant stimulation
Authors: Weber Thomas B. 
Published: December 2017

Thirty-one healthy, male individuals in a 17–21-year-age group were subjected to a bilateral collection of parotid secretion. Flow was elicited by chewing flavored chicle for a total stimulation period of 1 hour. All collections were made under carefully controlled regimen with minimal environmental and physical changes tolerated. Minute-to-minute rates of flow were not found to be predictable, but there was a pattern which was dependent upon the masticatory and gustatory stimuli. In a given individual it was possible to predict the flow rate of each of the parotid glands over 15-minute intervals. No glandular exhaustion was evident and hourly rate of flow was remarkably constant. Each gland showed an inherent individuality which was apparent throughout the complete period of excitation. Submitted on March 14, 1960
Factors affecting survival of mouse bone marrow cells during freezing and thawing in glycerol
Authors: Tran Phan The , Bender M. A. 
Published: December 2017

The effects of freezing rate, thawing rate and repeated freezing and thawing on the survival of mouse bone marrow cells frozen in various concentrations of glycerol were studied. The ability of thawed cells to promote recovery in lethally irradiated (900 r) mice was used as a measure of their viability. The experiments show that for best survival the cells should be ‘slow’ frozen in an additive solution, such as 15% glycerol. They should be ‘fast’ thawed. Repeated freezings and thawings lead to both a loss of cells and a more rapid loss of their ability to promote recovery. It is unnecessary to remove the glycerol from cells if they are to be used soon after thawing. Submitted on February 8, 1960
An improved procedure for determination of cardiac output by a conductivity method
Authors: Hershgold Edward J. , Steiner Sheldon H. , Sapirstein Leo A. 
Published: December 2017

The applicability of the hematocrit dilution technique employing arterial blood conductivity changes to the determination of the cardiac output has been extended by a) electronic damping of the detecting circuits, which permits greater amplification of the signal without increasing the variability of the base line that occurs during each cardiac cycle, and by b) development of a solution isoosmolar and isoconductive with plasma that substitutes for autogenous plasma in the procedure. The preparation of the synthetic solution is described. It is shown that this solution gives results indistinguishable from those obtained with plasma. Values are given for the conductivity and osmolarity of dog plasma. Submitted on December 3, 1959
Generation of coagulation product I and its interaction with platelets and phospholipids
Authors: Horowitz Herbert I. , Spaet Theodore H. 
Published: December 2017

Product I, a potent intermediate of blood thromboplastin formation, was generated by incubating diluted adsorbed plasma and serum reagents with calcium and was assayed with a substrate plasma containing added crude cephalin. Product I generation is accelerated by small quantities of thrombin. The subsequent reactions of fully formed product I leading to the formation of active blood thromboplastin have been found to be virtually instantaneous in the presence of optimal concentrations of available phospholipids. A time-consuming reaction of approximately 15 seconds occurs between the product I and intact platelets, wherein the platelet phospholipid is made available for blood thromboplastin generation. Submitted on August 11, 1960
Altitude tolerance of chickens and pigeons
Authors: Altland Paul D. 
Published: December 2017

Chickens and pigeons were exposed for 6 hours to various simulated high altitudes to determine the highest altitude tolerated without deaths and the lowest altitude at which there are no survivors. Six- to seven-week-old chicks were less tolerant than twenty-to twenty-five-week-old chickens. All chicks survived exposure to 12,000 feet, 90% survived 14- and 16,000 feet and, at higher altitudes, the survival was progressively lower until none survived at 26,000 feet. All older chickens survived exposure to 16,000 feet; approximately 88% survived altitudes up to 20,000 feet and, above this, survival was greatly decreased until none survived at 26,000 feet. Roosters showed a greater altitude tolerance than hens, a sex difference contrary to that found in mammals. Six- to ten-week-old pigeons survived 6-hour exposures to all altitudes including 28,000 feet and 97% survived exposure to 30,000 feet. Only 27% survived 32,000 feet and all died within 10 minutes at 34,000 feet. The results indicate that chickens have a much lower altitude tolerance than all other small warm-blooded animals previously studied. Submitted on July 11, 1960
Age trends in fat in normal and obese children
Authors: Pařízková Jana 
Published: December 2017

Body density was determined in 151 normal boys and girls 9–17 years old by hydrostatic weighing and simultaneous determination of residual lung volume by the nitrogen dilution method. Also, 56 obese children 9–15 years old were studied. Body composition changed characteristically in the groups of normal children. In boys, density at 9 years was 1.062 (S.E. = 0.003) and fell to 1.048 (S.E. = 0.004) at 11–13 years; it rose to 1.073 (S.E. = 0.002) at 16, indicating a relative decrease in fat content and increased development of lean body mass. In girls, values were more stable-1.041–1.042 (S.E. = 0.003–0.004) on the average, except in the year 13–14 when body density increased to 1.051 (S.E. = 0.004). After the start of clinical puberty, body density again fell to 1.038 (S.E. = 0.003) indicating increased fat content. There was significant sexual difference in body density before the beginning of prepuberal acceleration of growth and later with the start of clinical puberty. Body density for obese boys 9–12 years old was 1.010 (S.E. = 0.002) and for obese girls of the same age 1.009 (S.E. = 0.002). In 13–15-year-old obese boys, density was 1.016 (S.E. = 0.003) and for girls was 1.012 (S.E. = 0.0039); i.e. in obese children no sex or age differences in body density were found. Submitted on May 9, 1960
Hormonal determinants of mammalian tolerance to acceleration stress
Authors: Polis B. David 
Published: December 2017

The pituitary-adrenal hormonal axis has been implicated as a critical factor in the survival of the rat to acceleration stress. The physiological end point for the tolerance of animals to high positive acceleration stress was obtained by determining the time to reduce the heart rate from 8 to 2 beats/sec. at 20 g. With this technique, a significant increase (300%) in the survival time of rats to 20 g was found following hypophysectomy. A significant loss (60%) of tolerance to high acceleration stress was found in adrenalectomized rats. The procedures of hypophysectomy plus adrenalectomy apparently opposed the effect of each operation alone in the rat to yield an animal that tends to approach the normal rat in its ability to tolerate acceleration. A significant drop in the tolerance to acceleration of hypophysectomized rats was found 7 and 15 weeks after operation compared to that found with the animals 3 weeks after hypophysectomy and a significant increase in the tolerance of the adrenalectomized rat was found 11 weeks after operation compared to the tolerance at 5 weeks after adrenalectomy. In both operated populations, the direction of change was toward the tolerance level of the normal rat. Note: (With the Technical Assistance of Anne Zella) Submitted on September 12, 1960
Effect of diet on body temperature during sleep in the cold
Authors: Kreider Marlin B. 
Published: December 2017

Thirteen young soldiers were divided into two groups and fed liquid diets of similar caloric content but of different composition. One group was fed a normal, high-fat, high-carbohydrate and normal diet in the first, second, third and fourth weeks, respectively; the second group was fed a normal, high-carbohydrate, high-fat and normal diet during the same periods. Three meals were eaten at 8 a.m., 5 p.m., and 10:15 p.m., at which times 30, 30 and 40% of the daily calories were consumed. Measurements of skin (11 points) and rectal temperatures were made at one-half-hour intervals throughout the night when the subjects were in sleeping bags at an ambient temperature of –30°F. Protection against the cold was designed to be inadequate to maintain thermal comfort. Composition of the diet had no effect on rectal, mean weighted skin or toe temperatures throughout the night with a few exceptions. No physiological significance is ascribed to these exceptions since the differences were very small. It is concluded by comparison with a previous study that caloric content rather than composition of the diet is the important factor in decreasing rates of body cooling of men sleeping in the cold. Submitted on October 14, 1960
Effects of carbon dioxide on cold-exposed human subjects
Authors: Bullard Robert W. , Crise John R. 
Published: December 2017

Human subjects were exposed to an ambient temperature of 5 C for 75-min periods. Subjects breathed 2.5%—6% carbon dioxide for selected time periods during the exposure. Carbon dioxide appeared to inhibit shivering. After carbon dioxide inhalation, shivering and metabolism were greatly increased. When 6% carbon dioxide was inhaled for 30 min, the inhibition was overcome and shivering and metabolism approached high levels. The increased respiratory heat loss associated with carbon dioxide breathing may be one factor causing the breakthrough of the inhibition. Submitted on November 14, 1960
Cutaneous vasodilatation elicited by body heating in calf, forearm, cheek, and ear
Authors: Senay Leo C. , Christensen Margaret , Hertzman Alrick B. 
Published: December 2017

When seminude subjects were exposed to a slowly rising ambient temperature (25—45 C), the onset of cutaneous vasodilatation occurred simultaneously in the calf, forearm, cheek, and ear, and the further progress of the vasodilatation was similar in the last three regions. That in the calf and toe often differed from that in the forearm. Either the vasodilatation in the calf was small or it stabilized early while the forearm vessels continued to dilate markedly. One subject repeatedly presented an exception in that a marked vasodilatation in the calf considerably exceeded that in the forearm. He was a poor sweater and exhibited unusually high skin temperatures. The usual failure of the skin temperature to rise as much in the calf as in the forearm appeared to be closely related to the lesser cutaneous vasodilatation. There was no evidence that local sweating elicited local vasodilatation; on the contrary, evaporative cooling seemed to decrease the vasodilatation, particularly in the calf. The cutaneous vascular events were followed continuously in each region by means of photoelectric plethysmography. Submitted on December 27, 1960