bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ventilatory mechanics and strength: long-term re-examinations and position change
Authors: Brody Alfred W. , O'Halloran Patrick S. , Wander Harry J. , Connolly John J. , Roley Everett E. , Kobold Elmer 
Published: December 2017

Sixteen comparisons (3 in females, 13 in males) were made of pulmonary function tests in the standing, seated and supine positions. The significant changes were an increase in tidal volume on standing from either the seated or supine positions, but no change on lying (supine) from the seated position; a progressive decrease in the expiratory reserve volume on going from the standing to the seated to the supine positions; an increase in the inspiratory capacity on lying supine from either seated or standing positions, but no significant change on standing from the seated position; and a suggestion of increased turbulence (k2 term) on passing from the seated to either of the other positions. The other functions tested (minute volume, vital capacity, maximal pressures, elastance, resistance, maximal flows) did not change significantly. The variation and progression of week-to-week changes are described for five paralyzed patients after poliomyelitis and three normal subjects studied over a 2–3 month period. The changes occurring in five normal subjects studied at about 9-month intervals for periods of 9–39 months are also described. Submitted on August 17, 1959
Influence of unilateral hypoxia on blood flow through the lungs in man in lateral position
Authors: Arborelius M. , Lundin G. , Svanberg L. , Defares J. G. 
Published: December 2017

The relative blood flow through the separated lungs was determined with six subjects in lateral position. The amount of CO2 eliminated from each lung and the end-tidal air composition gave the necessary data to determine the relative flow through each lung, at assumed total blood flows through both lungs of 3, 6 and 12 liters. The lower lung was allowed to breath 10% oxygen in nitrogen and the upper lung air. The values obtained at all the above mentioned total blood flows were about the same, and also did not show any difference from the values obtained when both lungs were breathing 30% oxygen in nitrogen. In the last case the relative blood flow is assumed to be the same as the relative oxygen uptake for each lung. Hypoxia on the lower lung thus does not cause any shift to the air-breathing lung. This is in contrast to earlier experiments, performed by the authors, with the subject in supine position. Using the same measuring technique, it was then found that hypoxia on one lung caused a large shift of blood to the air-breathing lung. Submitted on February 1, 1960
Maximal work production in man
Authors: Fletcher J. G. 
Published: December 2017

The ability to perform hard physical work was studied quantitatively in 12 well-motivated men who undertook to step up and down a 22-inch bench 30 times every minute until exhausted. By this procedure a 150–lb. man performs external work at a rate of 0.25 h.p. or 1140 kg-m/min. When first tested, nonathletes were not able to step as long as athletes, inactive subjects as long as active ones, or athletes out of training as long as those in full training. Seven subjects exercised repeatedly. All found that their endurance increased by 100% or more. In five of them the improvement exceeded 500%. Reductions in pulse rate, at rest and after standard periods of stepping, accompanied the training process. Submitted on December 7, 1959
Alveolar-arterial oxygen gradient in the dog at altitude
Authors: Kreuzer F. , Tenney S. M. , Andresen D. C. , Schreiner B. F. , Nye R. E. , Mithoefer J. C. , Valtin H. , Naitove A. 
Published: December 2017

The effect of a sojourn of 5 days at an altitude of 14,300 feet (White Mountain, Cal.) on the alveolar-arterial oxygen gradient (A-aDo2) in the anesthetized dog was studied at three levels of oxygenation. Two dogs breathed 11% o2, air and 100% o2 at sea level, and air, 40%, and 100% o2 at altitude, with ventilation kept constant by means of a respiration pump. The alveolar samples were analyzed for o2 and CO2 pressures with the Scholander apparatus and the arterial o2 pressures were measured in an in vitro polarograph. Control studies showed that the pump itself and hyperventilation had no effect on the A-aDo2. The average values of A-aDO2, 8.6, 23.4 and 168.5 mm Hg, at sea level (the three values refer to the respective three levels of oxygenation; the last figure corresponds to a shunt of about 12% of cardiac output) agreed well with previous data. The corresponding average values of A-aDO2 at altitude were: 3.3, 17.0 and 58.0 mm Hg (corresponding to a shunt of about 4%). The A-aDO2 breathing air was lower at altitude than when breathing an equivalent oxygen tension at sea level. The most dramatic effect consisted in a threefold decrease of the A-aDO2 with 100% O2 at altitude, indicating a decrease in true veno-arterial shunt flow. Submitted on February 8, 1960
Relationship of carotid pressure and end point during acceleration
Authors: Kydd George H. , Fenichel Richard L. , Crosbie Richard J. 
Published: December 2017

Simultaneous observations have been made of the occurrence of an end point of unconsciousness and carotid blood pressure in rhesus monkeys during positive acceleration. The data indicate that the carotid pressure is influenced initially by a maneuver which gives rise to a positive wave of pressure that is well coordinated with the onset of tangential acceleration, while positive acceleration is at a very low level. Following this, there is a pressure drop that can be described by a time constant, that is, a function of peak g. The data indicate that the end point occurs after a constant interval following the pressure minimum and is therefore related to the slope of the blood pressure curve. The significance of this observation with respect to blood supply is discussed. Submitted on March 14, 1960
Relation of olfactory acuity to nasal membrane function
Authors: Schneider Robert A. , Wolf Stewart 
Published: December 2017

The relationship between olfactory perception threshold and accompanying degrees of nasal obstruction, swelling, color and wetness was studied in eight subjects over a prolonged period. Olfactory acuity was impaired in two situations: a) in the presence of high degrees of nasal obstruction so that relatively little of the odorant-containing air could be brought into the nose, and b) in the absence of obstruction when the mucosa was relatively pale, dry and shrunken. During intermediate degrees of nasal obstruction when substantial amounts of air could be drawn into the nose relatively high degrees of swelling, redness and wetness favored olfactory acuity. Thus smelling was best performed in the presence of a red, swollen, wet mucosa as long as swelling and secretions were not of such a degree as to substantially block air passage. The evidence suggests that contact of odorant with nerve endings is facilitated by the greater warmth and humidifying effect of nasal engorgement during hyperfunction of the ‘air-conditioning’ apparatus of the nose. Submitted on March 14, 1960
Method for kinetic study of in vitro conversion of a C14-labeled substrate to CO2
Authors: Allweis Cecil L. , Gainer Harold , Chaikoff I. L. 
Published: December 2017

A method is described for the determination of CO2 and C14O2 production rates by tissue slices incubated in the presence of a constant concentration and constant specific activity of a C14-labeled substrate. The constant conditions were maintained by periodic replacement of the incubation medium and gas phase. It is pointed out that, in order to determine the true rates of conversion to CO2 of an exogenous labeled substrate and of an endogenous, nonequilibrating CO2 precursor, measurements must be made after isotopic equilibration is attained. In the case of whole brain slices, such equilibration was observed after 3–4 hours of incubation. With glucose as the exogenous substrate, 30–40% of the CO2 produced by rat whole cerebrum slices was derived from endogenous sources for as long as 12 hours. Submitted on December 14, 1959
Suggested methods of testing and standards of resistance for respiratory protective devices
Authors: Cooper E. A. 
Published: December 2017

There is need to establish a method of bench testing and standards of allowable resistance for respiratory protective devices. It is suggested that a technique for recording pressure-volume diagrams using a sine-wave pump is satisfactory. Standards of resistance are proposed which are expressed as total rate of respiratory work done on the apparatus, and the percentage of this which is done in expiration. It is suggested that apparatus should be tested at minute volumes up to 100 l/min. Other information derivable by this technique is discussed. Fundamental principles of aerodynamics are also considered in relation to closed-circuit breathing apparatus. It is shown that under conditions of practical use of such systems, flow is only laminar in rare instances. Useful information can be gained about the frictional resistance of a respiratory circuit from simple bench tests at various constant rates of flow of air, and from the results of such experiments theoretical calculations can be made of the rate of work done. They are shown to correspond well with the measured rates of work done by human volunteers when breathing against the same resistance at all levels of exertion on a treadmill. Submitted on March 7,1960
An improved heart-lung preparation ventilated by negative pressure
Authors: Sheehan William L. , Kinzie William B. , Westbrook Kenneth L. , Spencer William A. , Hoff Hebbel E. 
Published: December 2017

Five isolated canine heart-lung preparations were successfully ventilated with intermittent negative pressure in a specially constructed chamber. Improved cardiopulmonary dynamics resulted in increased survival time and improved performance of all preparations. Results obtained with these preparations exceed most of the others reported in the literature. Submitted on May 9, 1960
Seasonal acclimatization to cold in man
Authors: Davis Thomas R. A. , Johnston D. R. 
Published: December 2017

Six subjects were measured once monthly from October to February for alterations in shivering, heat production, and rectal and skin temperatures produced by a standard cold exposure of 14.1 α 0.46°C for 1 hour. The responses of a second group of five subjects were measured once monthly from February to September during a cold exposure of 13.7 α 0.9°C. In the October-February group, shivering decreased to a January mean value 7% of the October figure ( P < 0.01). Cold-induced heat production decreased in February to a value 52% of the October figure ( P < 0.05). Mean rectal temperature and mean surface temperature over the total period of study showed no consistently significant change. The decrease in shivering was associated with a change in the surface temperature threshold of shivering onset. The February-September group showed an increase in shivering reaching a maximum in September ( P < 0.01). Again consistently significant alteration in surface or rectal temperature could not be demonstrated. The highly significant change in shivering and the less significant change in heat production observed suggests that man seasonally acclimatizes to cold and that this acquired acclimatization is lost during the summer months. Note: (With the Technical Assistance of F. C. Bell, W. Rawlings and L. Lee) Submitted on May 27, 1960
Evaluation of venous occlusion plethysmograph
Authors: Conrad Margaret C. , Green Harold D. 
Published: December 2017

Inflow and outflow, occlusion and perfusion pressures, and pressure in a small vein in the paw were measured simultaneously with the plethysmogram on the amputated forepaws of dogs. Venous tamponade was complete for a period of time dependent on the height of occlusion pressure and the magnitude of arterial flow. Paw venous pressure rose rapidly to 'effective occlusion pressure,' at which time blood began to escape beneath the occlusion cuff. Arterial flow began to decline immediately after occlusion. Two occlusion artifacts were observed. The first was an abrupt deflection that could be easily avoided on the plethysmogram, and the second was a slower rise that could be detected only when inflow was interrupted prior to occlusion. The plethysmographically measured flow was not significantly different from inflow measured with the electromagnetic flowmeter because of a balance between the positive error due to artifact and the negative error due to the effect of occlusion on inflow. Submitted on September 22, 1960
Aortic mechanics in the living dog
Authors: Patel Dali J. , Mallos Alexander J. , Fry Donald L. 
Published: December 2017

The relationship between longitudinal strain, circumferential strain, lateral intravascular pressure, blood velocity, and longitudinal motion was examined in the aortas of 25 living thoracotomized dogs. Electrical calipers with adequate recording characteristics were used for instantaneous measurement of diameter and length. The results indicate: a) with inspiration, the thoracic aorta increased in length and the abdominal aorta shortened. b) During cardiac systole the length in the thoracic aorta increased with a rise in pressure, mean value for longitudinal extensibility x 103 was 15% (α 4.8 S.D., α 1.1 S.E.M.) per centimeter H2O pulse pressure. The mean value for the ratio of circumferential extensibility to longitudinal extensibility was 10. c) The abdominal aorta shortened with cardiac systole. This shortening is thought to be produced by elongating strain of the thoracic aorta. d) The absolute magnitude of aortic wall velocities, both radial and longitudinal, was very small as compared to the blood velocity at the same site. Submitted on August 18, 1960
Physiological alterations in increased pulmonary blood flow with and without pulmonary hypertension
Authors: Ellison Lois T. , Hall David P. , Yeh Thomas , Mobarhan H. , Rossi Joseph , Ellison Robert G. 
Published: December 2017

Alterations in pulmonary function and in hemodynamics were studied in dogs with high pulmonary blood flow resulting from systemic pulmonary artery shunts. In order to facilitate elevation in pulmonary artery pressure, the vascular bed was reduced in some cases by obstructing branches of the pulmonary artery with Teflon clips or by lobectomy. Results in 30 control dogs and in 30 animals that survived 5–36 months (average 16) following creation of shunts indicated that pulmonary function was not significantly altered by increased pulmonary blood flow until pulmonary artery hypertension developed. When systolic pulmonary artery pressure exceeded 40 mm Hg, there was a decrease in arterial Po2, an increase in venous admixture percentage of cardiac output, and an increase in the A-a O2 difference during three levels of O2 breathing, indicating both abnormal venous admixture and abnormal diffusion. Possible explanations for these findings are presented. Evidence in one dog suggests that these alterations are reversible. Submitted on August 10, 1960
Tritium used for estimation of right-to-left shunts
Authors: Lassen Niels A. , Mellemgaard K. , Georg J. 
Published: December 2017

A method is described for estimating right-to-left shunts through the determination of the recovery of intravenously injected tritium gas in the arterial blood. Tritiated water was used as an indicator of the dilution that would have occurred had no loss of tritium gas taken place in the alveoli. In normal man, average recovery values obtained were: 1.1% during normal respiration, 0.6% during hyperventilation, 0.9% during inspiratory apnea and 1.8% during expiratory apnea. In two patients with congenital heart disease large recovery values were found with right-to-left shunt, agreeing with the shunt estimates obtained using oxygen analysis. While no significant diffusion limitation at the alveolar membrane can be supposed to occur normally, a significant back pressure results from the gradually increasing alveolar tritium concentration. This factor is presumably responsible for the greater part of the recovery found in normal man, while a smaller part may be due to actual bypassing of the alveoli. On the basis of the experiments it is estimated that in normal man 0.3% of the blood entering the right side of the heart reaches the left side without passing air-filled alveoli. Submitted on November 5, 1960
Prediction of skin temperature of men in the cold
Authors: Iampietro P. F. 
Published: December 2017

Skin temperatures of seminude men were measured during 2-hr exposures to various combinations of air temperature (90–25 F) and wind velocities (< 1, 5, 10 mph). The data were used to derive an expression for the estimation of mean weighted skin temperature as a function of duration of exposure (up to 180 min), air temperature (90 to -20 F), and windspeed (0–40 mph). A chart was also constructed for more rapid estimation of skin temperature. Submitted on August 17, 1960
Basal metabolic rate and body composition at high altitudes
Authors: Picó;n-Reátegui E. 
Published: December 2017

Basal metabolic rate (BMR) and body composition were determined in 17 healthy adult males living at an altitude of 14,900 ft above sea level. Using body surface area as a standard of reference and following the criterion of Boothby et al. ( Am. J. Physiol. 116: 468, 1936), the BMR of the high-altitude resident fell within the limits considered normal for healthy adults at sea level. A comparison with the data obtained by investigators in the United States and in India shows that, when either fat-free body mass (FFM), cell mass (C), or cell solids (S) are the standard of reference, the BMR is higher in the high-altitude resident. The higher O2 consumption per kilogram of FFM, C, or S in the high-altitude resident seems to be one of the many mechanisms developed by the body in its process of adaptation to the low O2 tension. Note: (With the Technical Assistance of Melquiades Huayna-Vera) Submitted on October 24, 1960
Unequal distribution of pulmonary diffusing capacity in the anesthetized dog
Authors: Piiper Johannes , Haab Pierre , Rahn Hermann 
Published: December 2017

In anesthetized dogs the alveolar-arterial O2 pressure difference (AaD) was measured at alveolar O2 pressures of 45, 75, 106, 146, and 255 mm Hg. The AaD values observed could not be explained by the conventional “shunt factor,” “diffusion-limitation factor,” or “distribution factor.” However, the experimental data could be explained on the basis of the concept of unequal distribution of pulmonary diffusing capacity, D, to perfusion, Q. A procedure for estimation of the pattern of distribution of D to Q from experimental data is described. The results were compatible with the assumption that the lung consisted of a minimum of three functional compartments characterized by different D/Q ratios. A small portion of the perfusion (1.5%) probably behaved like a true shunt (D/Q = 0); 13% of the pulmonary blood flow passed through a compartment that shared in 2% of the total diffusing capacity only, resulting in a relatively small D/Q ratio for this compartment. The presence of this compartment gave rise to the largest part of the AaD at air breathing. The calculated D/Q value for the remaining, major compartment was so high that a measurable AaD due to diffusion limitation in this compartment could occur only at alveolar O2 pressures lower than 60 mm Hg. The validity of the assumptions and the significance of the results are discussed. Submitted on May 23, 1960
Equation for inert gas exchange which treats ventilation as cyclic
Authors: Riggs Douglas S. , Goldstein Avram 
Published: December 2017

When a constant concentration of an inert gas is inhaled, the rate at which the equilibrium quantity of the gas in blood and tissues is approached depends upon many factors. In previous mathematical descriptions of this process, ventilation has been assumed to be continuous. In the present analysis, respiration is treated as cyclic, and an equation for the time needed to achieve any given proportion of equilibrium is derived. This equation is a complex function of eight variables. However, two of these, the functional residual capacity and the volume of lung tissue, are of negligible importance. Furthermore, an n-fold increase in rate of respiration has almost the same effect upon the calculated rate of approach to equilibrium as an n-fold increase in alveolar ventilation per breath. The assumption that ventilation is continuous is therefore a legitimate simplification, and the complex equation has no practical advantage over a much less intricate formulation. Submitted on October 13, 1960
Urinary excretion of hippuric acid by man
Authors: Wu Hsien , Elliott Howard C. 
Published: December 2017

A simplified scheme for interpretation of urinary hippuric acid excretion data in terms of consecutive irreversible first-order processes is presented. The rate of excretion of endogenous hippuric, uric, and glucuronic acids is constant under the conditions of the experiments. The average value for the excretion constant KE for exogenous hippuric acid has been determined to be 2.7 hr-1 (0.0452 min-1) for doses of sodium hippurate ranging from 1 to 4 mEq. The average Ks for synthesis of hippurate from benzoate is 10.5 hr-1 (0.175 min-1) for doses of sodium benzoate ranging from 1 to 4 mEq. Study of 17 patients with varying degrees of renal disease as confirmed by standard p-aminohippurate and inulin clearances indicates that the determination of KE may be of value in the study of renal function, particularly where standard clearance techniques are not available. Preliminary data indicate that Ks may be useful in the study of the delay in synthesis of hippurate from benzoate that has been observed in some cases of liver pathology. Submitted on August 29, 1960
Effect of environmental temperature and humidity on intake and digestion of nutrients
Authors: Sharma D. C. , Kehar N. D. 
Published: December 2017

The intake and digestion of nutrients were measured in growing heifers of a good breed imported into a region of hot and humid climate notorious for the unthrifty condition of its cattle. The control group was maintained on the home tract of these animals. Effect of regional feeds, climate and seasons on feed and water intakes, digestibility of certain proximate principles and balances were studied to assess the extent to which alimentation becomes involved in the physiological adjustments to environments. The control group had a higher intake of feed, digestibility of dry matter, crude protein, ether extract and total carbohydrates, and balance of nitrogen than its counterpart on the same diet in a hot and humid area. Between the imported and local diet the animals preferred the diet of their home area. In all three groups there was a highly significant effect due to seasons. The interaction between group and season was also significant. Submitted on January 9, 1961
Estimation of heat flow from hands of Eskimos by calorimetry
Authors: Hildes J. A. , Irving Laurence , Hart J. S. 
Published: December 2017

Heat flow from hands immersed in cold water was studied in nine Eskimo and four white subjects. To assess the loss of heat from the hand circulation, the change in heat content of the hand during cold water immersion was first calculated from derived average hand temperatures. After 30 min cold water immersion, average hand temperatures were found to be approximately 6.5 C higher than the water. Derived values for circulatory heat loss averaged 15,564 cal for the Eskimos and 13,815 cal for the white subjects when the room temperature was 25 ± 2 C, and 11,167 cal and 10,610 cal, respectively, when the room temperature was 15 ± 2 C. However, an inverse relationship between hand volume and heat flow per 100 ml hand was found, and when considered on this basis no difference could be made out between the two groups although the number of subjects was too small for statistical comparison. The possibility that differences reported in the literature between groups of subjects are related to differences in hand size is discussed. Submitted on January 23, 1961