bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of acute pulmonary vascular congestion on recoiling force of excised cats' lung
Authors: Frank N. R. 
Published: December 2017

The effects of acute reversible pulmonary vascular congestion on the elastic behavior of excised cats' lungs were studied in 10 preparations. Measurements were made of changes in airway pressure at constantly held lung volumes over a wide range of deflation. To achieve vascular congestion left atrial pressure was raised to 20 and 30 cm H2O. Two effects were noted; one was that the slope of the volume-pressure relations of the lungs was slightly reduced at all levels of deflation, the other, the effect of vascular congestion on the recoiling force of the lungs was a function of the volume of the lungs at which congestion was induced. At large volumes (airway pressures of 5 cm H2O or more) recoiling force was increased; at intermediate volumes (airway pressures of 2.5 and 3 cm H2O) the change was negligible and, at smaller volumes, it was reduced in a manner consistent with the early work of von Basch. The findings suggest that there is a volume of the lungs, or perhaps a narrow range of volume, at which the lungs and blood vessels exert least mechanical stress on each other. This volume is believed to lie close to that in which tidal breathing occurs. Note: (With the Technical Assistance of Elcanor Gotz) Submitted on April 17, 1959
Effect of transverse acceleration on pulmonary function
Authors: Cherniack Neil S. , Hyde Alvin S. , Zechman F. W. 
Published: December 2017

Since difficulty with respiration limits tolerance to transverse acceleration, the effect of this acceleration on different respiratory factors was tested in 15 subjects. Minute volume, respiratory rate, tidal volume, maximum breathing capacity, 0.5-second timed vital capacity and total vital capacity were measured at 3 and 5 g with the subject's trunk perpendicular to the centrifugal force and legs and knees flexed at 90 degrees. Vital capacity was reduced significantly at 3 and 5 g. Maximum breathing capacity was significantly reduced at 5 g. One-half-second timed vital capacity represented an increasing fraction of total vital capacity as acceleration increased. Minute volume and respiratory rate also increased significantly at 5 g while tidal volume was essentially unchanged. Results are obtained which indicate that the nature of the predominant respiratory defect during forward acceleration is restrictive. Of the respiratory parameters measured, vital capacity showed the greatest decrement. Submitted on April 17, 1959
Effect of increased intra-abdominal pressure on various circulatory parameters of the anesthetized dog
Authors: Jach E. T. , Marotta S. F. , Marbarger J. P. 
Published: December 2017

Abdominal pressure of anesthetized dogs was elevated by the introduction of 18.5 mm Hg compressed air through a cannula tied securely into the peritoneal cavity. Significant decreases in circulating plasma volume (T-1824) were observed during the first 80 minutes of elevated pressure. Thereafter, plasma volume returned toward the control level except for a marked drop when the pressure was released. Hematocrit levels and plasma protein concentrations also indicated a loss of fluid. Mean vena cava pressure at the level of the heart did not markedly change, although the venous pressure below the diaphragm increased significantly. Arterial pressures decreased immediately upon elevation of the abdominal pressure, but returned to pre-experimental levels prior to release of elevated abdominal pressure. Concomitant with these circulatory alterations was a decrease in urine volume as well as a slight increase in serum potassium. Serum sodium remained essentially unaltered. These observations are compared to similar circulatory changes which occur during positive pressure breathing. Submitted on April 27, 1959
Electrical-mechanical relationships in experimentally produced bundle-branch block and complete heart block
Authors: Samet Philip , Litwak Robert S. , Bernstein William H. , Kenyon Norman 
Published: December 2017

Right and left ventricular pressure curves were recorded simultaneously with the electrocardiogram in the dog. Control observations were made during sinus tachycardia with normal intraventricular conduction, and repeated after production of right and left bundle-branch block and after production of complete heart block with idioventricular rhythm. The mode relationship between onset of isometric contraction in the two ventricles was 0.00 seconds during sinus tachycardia. During right bundle-branch block, left ventricular contraction started 0.01 second prior to the right; during left bundle-branch block, right ventricular contraction started 0.02 second prior to the left. During left ventricular idioventricular rhythm, left ventricular isometric contraction started 0.01 second prior to the right; during right ventricular idioventricular rhythm, right ventricular contraction started 0.01 second prior to the left. These changes in relative onset of ventricular contraction are far less than those expected on theoretical grounds. Submitted on March 26, 1959
Polarographic studies of skin oxygen tension following sympathetic denervation
Authors: Davis Martin T. , Greene Nicholas M. 
Published: December 2017

Using an open-tipped platinum electrode in the skin of the lower extremities of normal subjects, it was found that preganglionic sympathetic denervation resulted in a decrease in skin oxygen tension. This, in the presence of cutaneous hyperemia, indicates a decrease in capillary blood flow during the period of denervation. Submitted on March 5, 1959
Total and partial gas tensions of human bladder urine
Authors: Hong Suk Ki , Boylan John W. , Tannenberg Alf M. , Rahn Hermann 
Published: December 2017

The total and partial gas tensions of human bladder urine were studied by a modified Krogh micromanometric method combined with fractional absorption analysis and the use of a Clark oxygen electrode. Consumption of O2 by reducing substances in urine was determined and correlated with its specific gravity and pH. Oxygen tension of bladder urine averages 50 mm Hg during air breathing and 58 mm Hg during pure O2 breathing. Pco2 ranges from 47 to 152 mm Hg and correlates best with urinary pH. The average figure for urine nitrogen tension, 550 mm Hg, agrees closely with the calculated Pn2 of alveolar air. Total gas tension of urine is typically about 60 mm Hg less than atmospheric and changes in total gas tension are shown to reflect changes in Pco2, the tensions of the other gases remaining relatively constant in an experimental period. The physiological significance of these total and partial gas tensions is discussed. A counter-current gas diffusion system is proposed to account for the difference between the oxygen tension of urine and renal venous blood. Submitted on September 24, 1959
Finger numbness after acute local exposure to cold
Authors: Morton Rosemary , Provins K. A. 
Published: December 2017

Twenty subjects exposed the index finger to air at –22°C and a wind speed of 300 ft/min. until the indicated skin temperature fell to –5°C. The finger was then returned to room temperature conditions (19°C) and the subject tested on each of two tasks involving tactile discrimination until the finger had fully recovered. The degree of impairment on both sensori-motor tasks at a given skin temperature varied appreciably from subject to subject, although most subjects showed little impairment above about 8°C. The evidence suggests that while finger numbness as measured by Mackworth's V-test may indicate a corresponding impairment of performance in accuracy of pressure reproduction, testing subjects on either task at normal skin temperature will have little predictive value for their relative performance after cold exposure in the present situation. Submitted on December 24, 1958
Effects of oxygen inhalation on cold pressor responses of man
Authors: MacCanon D. M. 
Published: December 2017

The effects of oxygen inhalation on blood pressure and pulse rate responses to the cold pressor test were determined in 10 subjects. The results showed that under basal conditions diastolic pressures and pulse rates were significantly (P < 0.001) reduced by oxygen breathing. However, greater increases in systolic (P = 0.05) and diastolic (P < 0.01) pressures and pulse rates (P < 0.01) attended cold stimulation when oxygen was inhaled. One minute after removal of the cold bath, systolic and diastolic pressures remained significantly (P = 0.02, <0.001, respectively) further from basal levels during O2 experiments, although pulse rates had reached control values. Submitted on August 20, 1959
Effect of high and low humidity on heat exchanges of lightly clothed men
Authors: Iampietro P. F. , Buskirk E. R. 
Published: December 2017

Six healthy young men were exposed, lightly clothed, to various combinations of wind (<1 and 10 mph), temperature (40° and 50°F) and relative humidity (30 and 100%). Skin and rectal temperatures and oxygen consumption were recorded. The results show that relative humidity had no effect on the physiological responses measured, whereas wind and dry bulb temperature had marked effects. This follows the pattern seen when men were exposed without clothing and indicates that, under chamber conditions, there is little interaction between clothing and humidity that could account for cold-wet ‘chill.’ The importance of considering radiation in any comparison of cold-wet and cold-dry environments is discussed. Note: (With the Technical Assistance of J. A. Vaughan) Submitted on August 19, 195
Breath holding during and after muscular exercise
Authors: Åstrand Per-Olof 
Published: December 2017

Breath holding was performed a) at rest, b) at the beginning of muscular work, c) during the steady state of work and d) immediately after work. End-expiratory air was analyzed for CO2 and O2 tensions. At breaking point the PaCOCO2 values were similar in a) and b) (below 52 mm Hg with air breathing) and in c) and d, respectively. The higher the work load the higher the PaCOCO2 in c) and d) (above 70 mm Hg at heavy work load breathing air; after O2 breathing above 90 mm Hg). The PaOO2 values obtained were lower during and after work than at rest. These events and the increased ‘tolerance’ for high CO2 and low O2 in breath holding during and immediately after exercise are discussed in light of the theory that proprioreceptive impulses from working limbs are important in the control of respiration during exercise. Submitted on October 2, 1959
Hypoxemia due to venous admixture in cirrhosis of the liver
Authors: Williams M. Henry 
Published: December 2017

The percentage of venous admixture to arterialized blood was measured by two different techniques in two groups of patients with cirrhosis of the liver and, in both groups, averaged 9.7% of the cardiac output. Since one of the techniques was based on measurement of the arterial oxygen tension during oxygen breathing, the venous admixture must have resulted from some type of right-to-left shunt. It was not possible to determine whether the right-to-left shunt resulted from anastamoses between the portal system and the bronchopulmonary venous system or from pulmonary arteriovenous communications. Submitted on March 30, 1959
Respiratory dead space and arterial to end-tidal CO2 tension difference in anesthetized man
Authors: Nunn J. F. , Hill D. W. 
Published: December 2017

Observations were made during both spontaneous and artificial respiration on 12 fit patients anesthetized for routine surgical procedures. Above a tidal volume of 350 ml (BTPS), the anatomical dead space was close to the predicted normal value for the subject. Below 350 ml, it was reduced in proportion to the tidal volume. The physiological dead space (below the carina) approximated to 0.3 times the tidal volume for tidal volumes between 163 and 652 ml (BTPS). Throughout the range the physiological dead space was considerably in excess of the anatomical dead space measured simultaneously. The difference (alveolar dead space) varied from 15 to 231 ml, being roughly proportional to the tidal volume. The mean arterial to end-tidal CO2 tension difference was 4.6 (S.D. ±2.5) mm Hg and not related to tidal volume or arterial CO2 tension. None of the findings appeared to depend on whether the respiration was spontaneous or artificial. Submitted on September 25, 1959
Carbon monoxide diffusing capacity in normal male subjects, age 20–60, during exercise
Authors: Hanson John S. , Tabakin Burton S. 
Published: December 2017

The pulmonary diffusing capacity for carbon monoxide has been determined during steady-state treadmill exercise in 100 normal males, age 20–60 years. The method described provides a simple and acceptable technique for determination of diffusing capacity, obviating the need for arterial blood. Mean normal values and limits of normal have been established for the various age groups. Results agree closely with less extensive studies in the literature. The normal range for the Dco is seen to be quite wide, and the clinical value of the determination as a screening test is questioned. Submitted on July 6, 1959
Sweat iodide excretion in patients with cystic fibrosis of the pancreas
Authors: Brodkey J. S. , Gibbs G. E. 
Published: December 2017

Thirteen children with cystic fibrosis of the pancreas and fourteen normal children were studied. After preliminary saturation of the thyroid with Lugol's solution, a tracer dose of I131 was administered. Sweating was encouraged with wool blankets and heating pads. The sweat was collected on gauze pads which were then centrifuged to provide the free fluid. Sweat chloride was determined as were the number of disintegrations per minute in 1 cc of both sweat and serum. It was reconfirmed that fibrocystics excrete more chloride in their sweat than do normals. It was further found that fibrocystics excrete more iodide in their sweat than do normals. Submitted on September 29, 1959
Lung volumes at different depths of submersion
Authors: Hong S. K. , Ting E. Y. , Rahn H. 
Published: December 2017

Vital capacity and expiratory reserve volumes of the lung were measured in seven subjects in the supine position. These were reduced when subjects were submersed at depths of 10, 20, 30 and 40 cm below the surface while breathing through rigid tubes. The reduction in these lung volumes is similar to that observed when subjects are subjected to continuous negative pulmonary pressure. The equivalence of pressurization of the thorax by air and water is discussed. When man in the supine position is just submersed the resting lung volume changes are equal to that when a negative pulmonary pressure of 6 cm H2O is applied. Submitted on February 8, 1960
Cardiovascular responses of man during negative-pressure breathing
Authors: Ting E. Y. , Hong S. K. , Rahn H. 
Published: December 2017

Blood pressures, heart rate and finger volumes were recorded while supine subjects submitted to various degrees of continuous negative-pressure breathing. The lowest pressure was –30 cm H2O. Systolic and diastolic arterial pressures as well as heart rate remained essentially unchanged. The peripheral venous pressure estimated by an indirect method was slightly lowered. Finger plethysmography indicated a peripheral vasoconstriction to the same degree as observed during positive-pressure breathing. Various considerations suggest that during negative-pressure breathing the veins entering the thoracic cavity collapse and effectively divide the circulation into the thoracic one which operates at a considerably reduced pressure, and the nonthoracic circulation which is maintained at normal pressures. The pressure difference between these two circulations is maintained by the left ventricle. Submitted on February 8, 1960
Metabolism and temperature of Arctic Indian men during a cold night
Authors: Irving Laurence , Andersen Kristian Lange , Bolstad Atle , Elsner Robert , Hildes J. A. , L⊘yning Yngve , Nelms John D. , Peyton Leonard J. , Whaley Robert D. 
Published: December 2017

During 7 hours of comfortably warm sleep, average metabolic rates of 11 Indian and 7 white men were alike. Since the Indians were 15% lighter their metabolic rates (MR's) referred to weight were greater. During a night at 0° with insufficient covering, MR's rose to 129% and 132% in the two groups. Cold caused equal myographic records of shivering (15% and 13% of records) and gross muscular movement appeared in 6.5% of the records for each group. Encephalograms showed that Indians slept more (51%) than whites (31%). Shivering was recorded in Indians and white men during encephalographic indications of sleep. Rectal temperatures of Indians declined about 0.5°. During cold nights skin on the bodies of all subjects cooled 3°–5° and about 15° on the feet. All subjects were disagreeably cold, but their cold sensations stimulated metabolic heat production only half as much as would be necessary to maintain fairly comfortable warmth. Submitted on August 3, 1959
Effect of salicylates on ventilatory response to inhaled carbon dioxide in normal subjects
Authors: Samet Philip , Fierer Eugene M. , Bernstein William H. 
Published: December 2017

The basic purpose of this investigation was to determine whether salicylates increase the sensitivity of the respiratory center to inhaled CO2. The problem was approached by noting the effect of salicylates upon ventilation and arterial blood Co2 tension and pH during inhalation of compressed air and 3% and 5% Co2 in air. These studies were performed in 30 subjects, 15 of whom ingested 2.1 gm salicylate; the other 15 ingested 3.6 gm. The results demonstrate that the ventilatory response to CO2 was increased only by the larger dose of salicylate. Variations in dead-space volume secondary to increments in tidal volume were observed. Dead-space volume increased in approximately linear fashion with increase in tidal volume. Submitted on October 28, 1959
Some chemical, physical and biologic characteristics of dyes used to visualize lymphatics
Authors: Threefoot Sam A. 
Published: December 2017

Characteristics of dyes used to study lymphatics and other biologic systems can be of significance in quantification and interpretation of data. For example, determination of concentration is influenced by changes in spectral characteristics of solutions of Patent Blue V (PBV), T-1824 or Direct Sky Blue (DSB) produced by changes in pH. Interpretation of biologic data must consider the 50% binding of PBV and the almost 100% binding of T-1824 and DSB demonstrated by protein precipitation studies. This was confirmed for PBV by dialysis, but not for T-1824 or DSB because they adhered to the viscose bag as they did to the filter paper during attempts at electrophoresis. PBV moved independently of protein on electrophoresis, suggesting a weak linkage. After intradermal injection, all three dyes first visualized, then diffused from lymphatics. Only PBV appeared in urine in measurable quantities, approximately 10% being recovered in urine before it was too dilute to measure in 24 hours. One-half that excreted was recovered in the first 2½ hours. Submitted on January 25, 1960
Physiological behavior of I131-labeled compounds for the study of cardiac output
Authors: Homer George M. , Zipf Robert E. , Hieber Thomas E. , Katchman Bernard J. 
Published: December 2017

Radioiodinated diiodo-p-aminohippuric acid (DI131PAH) and N-(2,4-diiodo-3-hydroxyphenyl) urea (DI131HPU) were synthesized and examined for their potential usefulness in measuring the cardiac output in animals. These labeled compounds were injected intravenously into rats, rabbits and 13 dogs for study. The average rate of disappearance of DI131PAH from the blood stream of dogs was 50% and 90% in 1.0 and 6.9 minutes, respectively. Only a very small percentage of the injected radioactivity localized in the tissues, with approximately 0.5% in the thyroid at 24 hours. Under appropriate conditions of the experiment, more than 90% of the injected radioactivity was recovered in the excreta. Cardiac output values determined with DI131PAH on dogs were reproducible and in the range of reported values determined with other materials. Submitted on January 25, 1960
Measurement of human capacity for aerobic muscular work
Authors: Billings Charles E. , Tomashefski Joseph F. , Carter Earl T. , Ashe William F. 
Published: December 2017

In an effort to define a simple, precise measure of cardiovascular response to exercise, a test devised by Bruno Balke was studied. The test involves walking at constant speed on a treadmill, the slope of which is periodically increased, while heart rate is measured accurately each minute. Balke had noted that physiologic alterations indicative of impending exhaustion occurred at or near the time the heart rate reached 180/min.; he used the time at which the rate was attained as an end point. Our studies suggested that a single temporal measurement was insufficiently sensitive as an estimate of cardiovascular response to the procedure. Another scoring method was derived, involving the integration of heart rates with respect to time. A strong positive correlation was found between the described score and the work done during each of 133 test runs. Additionally, evidence was obtained which suggests that it may not be necessary to force subjects to an end point near exhaustion in order to estimate their ability to tolerate exercise of this type. Submitted on March 14, 1960
Electromyography of the diaphragm in man and transdiaphragmatic pressure
Authors: Agostoni E. , Sant'Ambrogio G. , Carrasco H. del Portillo 
Published: December 2017

The electrical activity of the vertebral part of the diaphragm in man has been studied in physiological conditions through an esophageal bipolar lead; the spirogram and/or the intrathoracic and gastric pressure were simultaneously recorded. Electrical activity has been found during inspiration; it is approximately related to the transdiaphragmatic pressure as the activity found during graded inspiratory efforts at relaxation volume. At minimum lung volume the electrical activity during maximum inspiratory efforts is small notwithstanding the high transdiaphragmatic pressure. Electrical activity may persist at the beginning of expiration, showing that the diaphragm does not relax completely at the onset of expiration. At the end of maximum expiration a small electrical activity may appear, the transdiaphragmatic pressure is high and it is not clear to what extent the diaphragm is passively distended or contracted. At relaxation volume during expiratory efforts electrical activity appears only when the effort is high, while during expulsive efforts, even moderate, the activity is marked. Submitted on May 2, 1960
Role of the diaphragm in breathing in conscious normal man: an electromyographic study
Authors: Petit J. M. , Milic-Emili G. , Delhez L. 
Published: December 2017

The electrical activity of the diaphragm was detected by means of electrodes placed, via the esophagus, at the level of the diaphragmatic esophageal orifice. This activity was synchronous with the respiratory variations of transdiaphragmatic pressure. The activity of the diaphragm, which occurred during inspiration and continued into expiration for a varying length of time, affected the shape of the pressure-volume diagrams of breathing cycles and of the expiratory flow curves. The relative importance of the antagonistic activity of inspiratory muscles opposing the expiratory elastic forces decreased with increasing ventilation. The implications of the antagonistic activity of the diaphragm on the mechanical efficiency of breathing are discussed. Submitted on April 11, 1960