bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interpretation of urinary N15-excretion data following administration of an N15-labeled amino acid
Authors: Wu Hsien , Sendroy Julius , Bishop Charles W. 
Published: December 2017

A discussion is given of the problems encountered in the interpretation of urinary excretion data when the isotope concentration versus time curve is fitted to an exponential equation. The possibility of evaluating the size of the initial pool of the specific amino acid which is administered in labeled form, and its rate of turnover, is illustrated with ammonia excretion data from intravenous glycine experiments. The calculation of the size of other pools is shown with ammonia, hippuric acid and urea excretion data from oral glycine and phenylalanine experiments. From the cumulative total-N15 and urea-N15 excretion data in the later ‘post-equilibrium’ period, the rate of (apparently irreversible) protein synthesis has been calculated. The values (about 1 mEq/hr/kg body weight) obtained in intravenous and oral experiments on man with phenylalanine, glycine, aspartic acid and ammonium citrate are substantially the same. As the labeled-NH2 is incorporated into more and more compounds and as each of these labeled compounds diffuses into an increasing number of compartments of the body, the apparent size of the mixed amino-N pool, as reflected in the isotope concentration of a urinary compound such as ammonia, seems to expand with time until eventually it equals the total exchangeable-NH2 in the body. Submitted on September 15, 1958
Suppression of sweet sensitivity by potassium gymnemate
Authors: Warren Richard M. , Pfaffmann Carl 
Published: December 2017

The leaves of Gymnema sylvestre, when chewed, temporarily depress sensitivity to sweet and bitter substances. The active principle, potassium gymnemate, was isolated and shown to have quantitatively equal effects on the sweet taste of threshold and suprathreshold concentrations of sucrose and sodium saccharin. The possible mechanisms of action are discussed. Submitted on December 10, 1956
Effects of restraint on oxygen consumption of the cold exposed guinea pig
Authors: Bartlett R. G. 
Published: December 2017

The oxygen consumption of cold exposed, restrained guinea pigs is significantly greater than that of cold exposed, nonrestrained controls. Similar observations have been made for the rat ( Canad. J. Biochem. & Physiol. 33:654, 1955). These data strongly suggest that heat production is greater in the restrained animal than in the nonrestrained control. The hypothermia, then, accompanying restraint in the cold cannot be laid to a decreased muscular activity (muscular activity is actually increased) and a consequently lessened heat production, as suggested by some ( J. Appl. Physiol. 12:214, 1958). It must be due, as demonstrated for the rat ( Am. J. Physiol. 193:557, 1958), to an increased rate of heat loss. The marked physiological changes accompanying restraint should serve as a warning to the investigator who uses restraint for convenience in data collection. Submitted on July 11, 1958
Body temperature responses to exercise in man on restricted food and water intake
Authors: Grande F. , Monagle J. E. , Buskirk E. R. , Taylor H. L. 
Published: December 2017

Rectal temperatures (TR) of 12 clinically healthy soldiers were measured in a room at 25.5°C and 40–45% relative humidity during a 1-hour walk on a motor driven treadmill at 3.5 mph and 10% grade, during control with adequate food intake and water ad libitum, and during a period of food and water restriction. The daily water intake during the water restriction period was 900 ml for six of the men, Low Water group (L.W.), and 1800 ml for the other six, High Water group (H.W.). The restriction of water began at the same time as the restriction of food and lasted 5 full days for the L.W. group and 10 full days for the H.W. group. Food was restricted to 1000 calories from carbohydrate, 4.5 gm of NaCl and a multivitamin pill/day for 16 days. Water ad libitum was given throughout the experiment except for the period of water restriction. The L.W. group showed a progressive increase of TR at the end of the walk during the water restriction period with average TR 1.51℃, higher at peak dehydration than in control. In the H.W. group the greatest average increase, 0.46℃, was observed on day 5 of restriction. Administration of water ad libitum brought the work TR back to the control level in the L.W. group, but failed to produce any important change in the H.W. group. The relationship between dehydration, elevation of TR during work and changes in sweat rate is discussed. Submitted on July 24, 1958
Fluorimetric determination of urinary adrenaline
Authors: Bischoff Fritz , Torres Adolfo 
Published: December 2017

A fluorimetric procedure for determining urinary adrenaline is described. This procedure eliminates the nonspecific blank occurring in the older methods to the extent that the levels obtained for urines collected under well defined physiologic states, such as sleep, moderate exercise and rest approach values obtained by bioassay as reported in the literature. The salient features of the method include a rigid control of pH at two critical steps, the addition of the standard to an aliquot of urine to correct for loss in processing and quenching, dilution of the sample to a point where quenching is minimal, and an optimal oxidation with MnO2 which destroys nonspecific fluorescent compounds without influencing the conversion of adrenaline to adrenochrome. Submitted on July 7, 1958
Cerebral free amino acids in dogs following infusion of ammonia
Authors: Eiseman B. , Osofsky H. , Roberts E. , Jelinek B. 
Published: December 2017

In order to clarify the biochemical changes occurring during experimental ammonia intoxication, the free amino acid content of brain tissue has been determined in suitable control dogs and in ten unanesthetized animals receiving bilateral carotid artery infusions of lactate-Ringer's solution containing 1% ammonium hydroxide until coma. The major change in dogs receiving the ammonia infusion was an increase in glutamine content proportionate to the time of the infusion. Occurrence of coma did not appear to be related directly to change in blood pH or to a critical level of carotid arterial ammonia concentration Submitted on May 29, 1958
Carbon monoxide determinations in postmortem tissues as an aid in determining physiologic status prior to death
Authors: Wilks Syrrel S. , Clark Robert T. 
Published: December 2017

With appropriate methodology, carbon monoxide in the ‘solid’ tissues of animals was quantitated and correlated with the blood carbon monoxide level in a series of controlled experiments with rats and dogs. Experimental conditions simulating aircraft crashes were devised and again the blood and ‘solid’ tissue CO levels were determined. Using the experimental data on animals as a basis for extrapolating blood CO levels, along with tissue CO values, obtained from ‘control’ and CO-asphyxial cases in human beings, an analysis was made of the ‘solid’ tissue specimens obtained in 186 fatal aircraft accidents. From the analysis of tissue specimens from approximately 200 aircraft crash cases, some 30% gave by this method a blood CO level in excess of 30% saturation. These results point to the likelihood that CO was present in the personnel compartments of some or all of these aircraft at some time during flight. Submitted on September 22, 1958
Intrapulmonary mixing of gases studied with aerosols
Authors: Altshuler Bernard , Palmes E. D. , Yarmus Leonard , Nelson Norton 
Published: December 2017

Mechanical mixture due to pulmonary flow, in contrast to mixing by molecular diffusion within the respiratory spaces, has been studied directly using aerosol inhalation. The technique uses particles, about ½ μ in diameter, which are fairly stable in the respiratory tract, and measures the concentration of aerosol during expiration with a continuous and rapid detector of scattered light and, simultaneously, the expiratory volume flow. The flow component of pulmonary ventilation is described in terms of the fractions of tidal air (Vx) and functional residual air (Vr) which participate in the ventilatory exchange of aerosol. Aerosol clearance experiments on three apparently healthy subjects show these two newly defined mixing volumes (Vx and Vr) to be much smaller than their analogous volumes measured by gas clearance: less than one-third for the fraction of tidal air and less than one-tenth for the fraction of functional residual air. These results demonstrate quantitatively the major role of molecular diffusion in ventilation. This approach provides a new method for the measurement of the mechanical component of intrapulmonary mixing. Submitted on November 3, 1958
Uniformity of pulmonary diffusion: effect of lung volume
Authors: Mittman Charles , Burrows Benjamin 
Published: December 2017

In two normal subjects, the effect of changing lung volume on the uniformity of pulmonary diffusion (uniformity of Dl/Vl) was studied using the breath-holding and equilibration methods. Nonuniformity of diffusion, as indicated by deviation from a true exponential in the disappearance of carbon monoxide from alveolar gas, was seen to increase with increasing lung volume. Over-all Dl increased significantly with increasing lung volume. When lung volume was controlled, equilibration and breath-holding diffusion methods yielded similar over-all Dl and similar variation in Dl/Vl throughout the lung. Submitted on January 29, 1959
Respiratory dead space measurements in a model lung and healthy human subjects according to the single breath method
Authors: Birath Gösta 
Published: December 2017

Observations on the dead space (Fowler's method) in a lung model were compared to observations on three human subjects. Corresponding to the theoretical gas front between dead space O2 and alveolar N2, a point in the model experiment was found dividing the S-shaped form of the N2 curve in a ratio of 2:3. The washout volume for the model dead space was about twice its volume. Similar findings were noted in the human subjects. Washout time did not influence the dead space values at flow rates of 5–37 l/min. In the human subjects the dead space values increased by 2.4–3.3 ml/100 ml of increasing end-inspiratory lung volume. The values for the dead space fell during an inspiratory pause even in the normal interval of quiet breathing. The accuracy of the method in tests on the model with a known dead space of 190 ml was 189 ± 1.4 ml with a standard deviation of ±7.0 ml. In human subjects the standard deviation was about 10%. Submitted on August 21, 1958
Effect of body position on esophageal pressure and measurement of pulmonary compliance
Authors: Ferris Benjamin G. , Mead Jere , Frank N. Robert 
Published: December 2017

In order to assess the effect of body position on esophageal pressure and pulmonary compliance, esophageal pressures were measured by means of a ‘long’ thin-walled balloon at the same lung volumes in different body positions in human subjects. Pulmonary compliance was measured by relating esophageal pressure change to associated lung-volume change. The data indicate that in the supine position false values of esophageal pressure and pulmonary compliance may be obtained. These false values appeared to be caused by an altered esophageal pressure as a result of gravity pressing other mediastinal structures against the esophagus. In the upright, lateral and prone positions esophageal pressures were similar to each other but different from those obtained in the supine position. These results suggest that measurements of esophageal pressure and pulmonary compliance in recumbent subjects are most reliable when made in the prone or lateral positions. Submitted on December 1, 1958
Carbon dioxide balance during thoracic surgery
Authors: Theye Richard A. , Fowler Ward S. 
Published: December 2017

Measurements were made of O2 uptake, CO2 output and CO2 tension of arterial and mixed venous blood and expired alveolar gas in 28 anesthetized and paralyzed dogs ventilated with air at a constant rate. Retention of CO2 was not observed in the lateral decubitus position with either closed or open thorax. Induction of open pneumothorax resulted in an unexplained metabolic alteration characterized by an increase in O2 uptake and CO2 elimination and a decrease in plasma buffer base. Small amounts of CO2 were eliminated from exposed pleura. The left pulmonary artery was occluded (after left thoracotomy) and 1 hour later the left bronchus also was occluded—or the order was reversed. CO2 retention of major degree was observed after initial occlusion of the artery and retention of minor degree after occlusion of the bronchus. During the 2nd hour (after additional occlusion) the previously retained CO2 was eliminated. The results suggest that the ventilatory requirements are not influenced specifically by effects of lateral position, open pneumothorax, or small right-to-left shunts, but rather are determined to a large degree by the metabolic production of CO2 and the degree to which ventilation is distributed to perfused alveoli. Submitted on December 3, 1958
Alveolar-arterial O2 differences during artificial respiration in man
Authors: Frumin M. Jack , Bergman Norman A. , Holaday Duncan A. , Rackow Herbert , Salanitre Ernest 
Published: December 2017

Alveolar-arterial oxygen differences were determined in anesthetized, paralyzed man. Approximately 20% of the determinations showed a Pa-a O2 of greater than 20 mm Hg. The arterial tension rose an average of 10 mm Hg when the expiratory pressure was increased from -5 to +5 mm Hg. The insertion of a 3-mm orifice expiratory resistance increased the arterial O2 tension an average of 7 mm Hg. The causes for these variations in arterial O2 tension and saturation are discussed. The functional residual capacity at +5 and -5 mm Hg expiratory pressure were determined by the nitrogen washout technique. The theoretically expected changes in alveolar O2 tension due to differences in the functional residual capacity accounted for only a third or less of the experimentally observed changes in arterial saturations and tensions. Submitted on February 6, 1959
Lung volume restriction as a ventilatory stimulus during breath holding
Authors: Mithoefer John C. 
Published: December 2017

Experiments on breath holding in man are presented which demonstrate that a restriction in the volume of gas in the lungs is an independent ventilatory stimulus which limits breath holding. This reflex stimulus interacts with the chemical stimuli from hypercapnia and hypoxia to determine the breaking point of breath holding. Previous work by others failed to demonstrate a relationship between lung volume restriction and hypoxia at the breaking point of breath holding with air. Experiments are presented which explain this and show that when hypoxia is present at the breaking point of breath holding, a time correction must be introduced to relate lung volume at the breaking point with the PaOO2 that existed several seconds before. When this is done the relationship between lung volume restriction and hypoxia becomes apparent. Submitted on March 2, 1959
Path taken by gases through the respiratory system of the chicken
Authors: Shepard Richard H. , Sladen Brenda K. , Peterson Norman , Enns Theodore 
Published: December 2017

The path of gases through the avian respiratory system was studied by comparing Pco2 and Po2 in expired gas and air sacs and Po2 in left ventricular blood. A respiratory mass spectrometer was used for gas analyses and an o2 electrode for blood Po2. Findings were: a) Pco2 and Po2 in air sacs varied little during the respiratory cycle; they fell when N2 was injected into the sac but returned rapidly to the original level in steps, a step with each inspiration. b) Po2 of left ventricular blood and air sac gas were essentially the same and varied less than 5% of total Po2 during the respiratory cycle. c) End-tidal Pco2 and Po2 were essentially the same as air sac Pco2 and Po2. The first two findings suggest that gas reaches the air sacs only via the respiratory surfaces of the lung. The third suggests that during expiration gas passes directly from air sacs to mouth without passing again over the respiratory surfaces. The path is therefore mouth-lung-air sacs-mouth, with almost complete valving despite the absence of demonstrable anatomical valves. Submitted on February 9, 1959
Upper airway obstruction in the unconscious patient
Authors: Safar Peter , Escarraga Lourdes A. , Chang Francis 
Published: December 2017

Airway patency was studied in 80 anesthetized, spontaneously breathing patients, who received no muscle relaxants. With the neck flexed (chin towards chest) the airway was obstructed in all patients, both in the supine and prone positions, with and without an artificial oropharyngeal airway in place. With extension at the atlanto-occipital joint (chin up) in the supine position approximately 50% of the patients had an open airway. The other 50% required, in addition to extension of the neck, forward displacement of the mandible or the insertion of an oropharyngeal airway or both. Roentgenograms demonstrated that the tongue is pushed against the posterior pharyngeal wall when the neck is flexed and the mandible is not held forward. The incidence and degree of obstruction was similar in the prone and supine positions, with comparable positions of the head, neck and mandible. Submitted on December 19, 1958
Methods of cooling subjects with hyperpyrexia
Authors: Wyndham C. H. , Strydom N. B. , Cooke H. M. , Maritz J. S. , Morrison J. F. , Fleming P. W. , Ward J. S. 
Published: December 2017

Six volunteers raised their rectal temperatures to 104℉ by 40–50 minutes' work at 93℉ wet-bulb temperature. The rates of fall in rectal temperatures were studied during cooling by six different methods. The most rapid method of cooling occurred when subjects sat at rest in an air condition of 90℉ dry bulb and 87℉ wet bulb and evaporative cooling was accelerated by wetting the body surface continuously for 1 hour; no significant difference in cooling was observed between airflows of 120 ft/min. and a jet of compressed air held 1–3 ft from subjects. Merely seating individuals in air conditions of 70℉ with 20% relative humidity in still air was almost as effective. Immersion in cold water and sitting in air conditions of 90℉ (D.B.) and 87℉ (W.B.) without aiding evaporative cooling are significantly less effective than the foregoing methods. Resting subjects at 97℉ (D.B.), 93℉ (W.B.) and 120 ft/min. air velocity results in very slow cooling. ‘Afterdrop’ in rectal temperature after ice-cold water cooling may be associated with severe circulatory shock. Oral temperatures are a less reliable index of core temperature than rectal. Submitted on February 16, 1959
Comparison of basal plasma and blood volumes of Negro and white males
Authors: Bass David E. , Iampietro P. F. , Buskirk E. R. 
Published: December 2017

Basal plasma and blood volumes of U.S. Negro soldiers were compared with those of white soldiers. Plasma volume (PV) was determined with T-1824; blood volume (BV) was calculated from PV and hematocrit. Both groups were matched with respect to height, weight, fatness-leanness and age; daily activity and diet were the same for all men for 2 weeks prior to measurements. The Negro group had significantly lower PV, BV and hemoglobin concentration than the white group. Hematocrits were the same for both groups. Mean values were (Negro vs. white): PV, 2.72 vs. 3.06 l.; BV, 5.05 vs. 5.71 l.; hematocrit, 46.2 vs. 46.5%; hemoglobin, 14.4 vs. 15.1 gm %. The limitations in attributing a significant role in cold or heat tolerance to differences in basal blood volume are discussed. Submitted on February 19, 1959
Cerebral metabolism of isotopic glucose in chronic mental disease
Authors: Sacks William 
Published: December 2017

A previous investigation of cerebral metabolism of isotopic glucose in normal human subjects was extended and similar studies performed upon chronic psychiatric patients. With variously labeled glucose-C14 as substrates, average activity-time curves and values for cumulative C14O2 resulting from cerebral oxidation of labeled glucose showed no significant variations between normal and psychotic subjects. A significant difference (P < 0.02) between the two groups did occur in comparing the fraction of brain CO2 derived from glucose. Calculations using individual glucose-U-C14 experiments gave averages of 56% for normal subjects and 36% for mental patients. These values agreed with those derived from composite curves of variously labeled glucose. That less brain CO2 was derived from glucose in psychotic subjects seemed to indicate a greater dilution of some carbohydrate intermediate(s) by protein and/or lipid intermediate(s); and, possibly, a decreased cerebral oxidation of carbohydrate. Theoretical considerations suggested that pyruvate and/or lactate might be the main site(s) of dilution. Submitted on January 28, 1959
Indirect estimation of body surface area and volume
Authors: Sendroy Julius , Cecchini Louis P. 
Published: December 2017

A convenient and rapid photographic technique of obtaining data which can be used for the calculation of human body surface area is described. The results, which are in good agreement with values obtained by a reliable method of readings from a chart, provide additional support for the application of the increasingly important photographic method of quantitation in human biology. Data have also been obtained which suggest that the surface area of dogs may satisfactorily be estimated by the same previously reported chart method used for human beings. Empirical equations for the calculation of body volume (and density) in man, based essentially on measurements of weight and height, have been developed and tested in respect to measured values obtainable from the literature. Statistical evaluation and the criteria of convenience and rapidity in use, rather than more restrictive theoretical considerations, indicate the superiority of predominantly empirical relationships as the methods of choice for the prediction of body volume. Comparison of the reliability of the results with those obtainable by established methods of quantitation indicates that these equations may be useful as approximate, but most convenient indices of gross body composition. Submitted on April 1, 1959
Glucose biokinetics in normal and ketotic cows
Authors: Kronfeld D. S. , Tombropoulos E. G. , Kleiber Max 
Published: December 2017

The size, turnover time and transfer rate of the glucose pool were estimated with glucose–C14 in normal and ketotic cows. The size and turnover time of the pool were both about 1/5 greater in the ketotic than in the normal cows, so that the transfer rate remained similar, being about 1 gm/min. The hypoglycemia which is characteristic of the disease appeared to be associated with an expansion of the glucose space, which in the normal cows approximated the extracellular volume, into the intracellular compartment of the ketotic cows. These results do not favor theories of bovine ketosis which presume a shortage of body glucose. Submitted on June 25, 1959
Maximum physiological concentration of sodium in human urine
Authors: Plough Irvin C. , Baker Eugene M. 
Published: December 2017

Six apparently normal young men received salt intakes of up to 540 mEq/day, or more, with free access to water. The five subjects who tolerated these high intakes drank enough water to maintain the sodium concentration in the 24-hour urine specimens at a mean of 268 mEq/l. with a range of means in the individual subjects of 240–295 mEq/l. Under these circumstances there was little change in the size of the body fluid compartments. The results indicate that there is a maximum physiological concentration of sodium in the urine, probably in the range of 270–290 mEq/l., which is similar to the ‘limiting isorrheic concentration’ described by Wolf. ( The Urinary Function of the Kidney. New York: Grune, 1950.) Submitted on July 16, 1959