bluuebunny/crossref_metadata_2025 huggingface dataset:
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
Relationships between maximal breathing capacity and timed expiratory capacities
Authors: Miller William F. , Johnson Robert L. , Wu Nancy
Published: December 2017

Maximal breathing capacity (MBC) and timed expiratory capacity (TEC) measurements are estimates of voluntary ventilatory capacity. The MBC embodies certain disadvantages and is dependent on coordination, endurance, learning, motivation, breathing rate and pulmonary mid-position at which breathing is performed. Correlations (R = > +0.91) were found for the relationship 0.5, 0.75 and 1.0 second TEC and the MBC in 153 normal subjects and 100 patients with ventilatory insufficiency. The MBC can be conveniently estimated from any of the TEC values with essentially equal reliability. This is only an approximation since expiratory flow rate is only one of the many variables determining the MBC. Aside from the effects of maximal inspiratory and expiratory flow rate on the determined MBC, the breathing rate must exceed 65/min. and the steepest slope of the expiratory flow curve must be repetitiously utilized, otherwise maximal ventilation is not achieved. The forced expiratory vital capacity and timed expiratory capacities are not merely convenient substitutes for the MBC, but deserve investigation as potentially valuable reflections of muscular and visco-elastic properties of the pulmonary apparatus.
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
Effects of piloting supersonic aircraft on plasma corticosteroids and bicarbonate
Authors: Hale Henry B. , Ellis James P. , Kratochvil Clyde H.
Published: December 2017

While flying high-speed military aircraft, pilots frequently hyperventilate to a degree sufficient to induce marked alkalosis. Psychogenic factors are thought to be responsible for the hyperventilation. Comparison was made of pre- and postflight plasma bicarbonate (determined titrimetrically) and corticosteroid levels (Sweat's technique) for 20 instructor pilots and 47 student pilots flying F-100 aircraft for 50 minutes. No differentiation of students and instructors was possible on the basis of either pre- or postflight values; therefore, the data for the two groups were combined. The plasma bicarbonate value following the flight was 1.1 ± .24 mEq/l. (mean ± S.E.) lower than before the flight. Free 17-hydroxycorticosterone was increased 5.8 ± .70 μg/100 ml, while conjugated 17-hydroxycorticosterone increased 5.7 ± .75. The free corticosterone-like fraction increased 3.1 ± .34 μg/100 ml, while the conjugated corticosterone-like fraction increased 3.2 ± .35. Each of these changes was significantly different from zero (P < .001). No statistically significant correlation was found between the fall in bicarbonate and any of the increases in steroid fractions.
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
Renal clearance and plasma protein binding of oxytetracycline in man
Authors: Kaplan S. A. , Yuceoglu A. M. , Strauss J.
Published: December 2017

The clearance of oxytetracycline was measured in eight children, four of whom also received glucosamine. The average clearance of oxytetracycline was 163.7 ml/min./1.73 m2 in the eight experiments and the average clearance of inulin was 115.8 ml/min/1.73 m2. About two-thirds of the oxytetracycline appearing in the urine was filtered at the glomeruli. One-third was secreted by the tubules. About three-fourths of the oxytetracycline in human plasma was found to be dialyzable and one-fourth bound to protein. Glucosamine (40 mg/kg) administered for 24 hours did not significantly modify the renal tubular secretion of oxytetracycline.

Note:

(With Technical Assistance by S. Graziano and R. Kanter)

Submitted on April 22, 1959
Pitfalls of the continuous histamine test for gastric secretory inhibition
Authors: Shapira Daniel , Cross Cecil , Morgenstern Leon , State David
Published: December 2017

Dogs with Heidenhain pouches were given histamine at a constant rate for 6 hours or longer. Output of HCl from the pouch was measured every half hour, and each secretory response was divided into control and test phases, according to the procedure of the continuous histamine test. However, no inhibitory factor was introduced. In 32 experiments the rate of HCl output reached a stable level during the control phase, but many responses failed to show stability throughout the test phase. Frequently, there was a pronounced drop in rate of HCl output below the pre-established control level. With the continuous histamine test, it is sometimes assumed that any appreciable drop in rate of HCl output during the test phase is attributable to the factor being tested and that it represents inhibition of the histamine-induced response. The results of the present study illustrate that this premise may be invalid under certain conditions. If control studies are not performed with the continuous histamine test, spontaneous drops in rate of HCl output are apt to be misinterpreted as evidence of inhibition.

Note:

(With the Technical Assistance of S. Mehta)

Submitted on September 8, 1958
An alveolar pCO2 control system: its use to magnify respiratory depression by meperidine
Authors: Lambertsen C. J. , Wendel H.
Published: December 2017

A system was devised combining means of a) automatic sampling of end-tidal gas, b) rapid analysis of samples gas for Co2 concentration and c) manual or automatic modification of per cent Co2 in succeeding inspirations to permit maintenance of alveolar pCo2 at desired levels above the Co2 tension natural for a particular experimental situation. By imposing a fixed, elevated alveolar pCo2 upon a subject, effects of drugs or physiological stresses upon Co2-sensitive functions can be evaluated, unmasked by the compensatory alterations of alveolar and arterial pCo2 which normally result from changes in alveolar ventilation or metabolism. Validation of alveolar pCo2 control in 16 normal subjects, using arterial pCo2 as a reference standard, revealed no significant difference between the imposed end-tidal pCo2 and the pCo2 of arterial blood. Use of the pCo2 control system to evaluate the dynamics of meperidine effect on respiration in normal men indicated sufficient magnification of the effect of meperidine on respiratory minute volume to permit use of the method for comparative studies of rate of onset, time of peak effect and rate of disappearance of the action of meperidine on respiration.

Submitted on July 9, 1959
Temperature distribution over the human head, especially in the cold
Authors: Edwards Merrill , Burton Alan C.
Published: December 2017

Two separate practical problems are the reduction of the total heat loss of the head, as by insulated helmets, and protection from frostbite, as by face masks. Solution of both problems benefits from knowledge of the distribution of skin temperature. Temperatures were measured with thermocouples at several points on three subjects, in the steady state, at environmental temperature of 0°C. Topographical differences were similar for the three subjects. Temperatures at a large number of points were measured in a single subject, and isothermal maps were drawn from the results. They show that the areas needing most protection from frostbite are the tip of the nose, the rim of the ears, the chin and the cheekbones. The areas of highest temperature (greatest heat loss) are those covered by the conventional insulated helmets. A face mask need not cover the area round the mouth where tactile sensitivity may make it uncomfortable. The isothermal map is correlated with the anatomical distribution of arterial blood supply.

Submitted on August 3, 1959
Attempt to demonstrate the distribution component of the alveolar-arterial oxygen pressure difference
Authors: Haab Pierre , Piiper Johannes , Rahn Hermann
Published: December 2017

Under normal conditions, the alveolar-arterial oxygen pressure difference (A-a difference) is believed to be due primarily to two causes, venous admixture (shunt component) and variation in ventilation-perfusion ratios (distribution component). In order to assess quantitatively the role played by the latter factor, the difference in O2 tension between end-tidal air and arterial blood was measured in anesthetized dogs under two conditions: a) at normal ambient pressure (Pb = 747 mm Hg), breathing air; b) at low ambient pressure (Pb = 192 mm Hg), breathing 100% O2. The essential feature of this procedure is that, while the inspired O2 tension is identical in both conditions, there is no nitrogen in the gas inspired at low ambient pressure. Theoretical analysis indicates that, if all or part of the A-a difference measured under condition a is due to a variation in ventilation-perfusion ratios, then this difference must be significantly reduced under condition b. Such a decrease in the A-a difference should provide an index of the magnitude of the distribution component. However, in our experiment, the A-a difference was found to be the same in both conditions. Therefore, our results do not support the hypothesis that there exists a large distribution component of alveolar-arterial difference.

Submitted on October 21, 1959
Respiratory and cardiovascular alterations during the process of anoxic death in the newborn
Authors: Cassin S. , Swann H. G. , Cassin B.
Published: December 2017

A systematic investigation was conducted during the process of anoxic death in newborn pups, rabbits and kittens less than 24 hr. old. Simultaneous measurements of respiration, heart rate and blood pressure were made. Considerable individual variation in the respiratory responses of newborn animals breathing nitrogen was noted. Under hypoxic conditions, respiratory failure may follow circulatory failure in the adult, whereas in the newborn, respiratory failure always occurred long before circulatory failure. The effect of anoxia on the cardiovascular system of the newborn at the time of the last breath was not as pronounced as might have been anticipated. Great individual differences with respect to blood pressure and heart rate throughout the period of anoxia were noted. The systolic blood pressure, on the average, was seen initially to fall more rapidly than the diastolic blood pressure or heart rate; it then slowly tapered off. The circulatory system was noted to function, although at hypotensive levels, for long periods of anoxia.

Submitted on June 29, 1959
Use of the restrained rat technique for study of the antiulcer effect of drugs
Authors: Hanson H. M. , Brodie D. A.
Published: December 2017

Five anticholinergic drugs, atropine sulfate, diphenmethanil, mepiperphenidol, propantheline and scopolamine methiodide, were studied for their effects on gastric ulcers in rats produced by the restraint technique. All the drugs significantly decreased ulceration; scopolamine methiodide appeared to be the most potent drug tested, followed by propantheline, atropine, diphenmethanil and mepiperphenidol. Three central nervous system depressants, chlorpromazine, benactyzine and pentobarbital, all decreased the incidence of ulcers with no differences in potency. Acetazolamide administered daily for 5 days had no effect on ulceration. Prednisolone administered daily was found to increase the time required for recovery from restraint-produced ulcers.

Submitted on November 6, 1959
Control of respiratory frequency
Authors: Mead Jere
Published: December 2017

Previous work has shown that for a given level of alveolar ventilation there is a particular respiratory frequency which is least costly in terms of respiratory work. There is also a particular frequency, usually a different one, which is least costly in terms of average force of the respiratory muscles. Evidence is presented that in the resting guinea pig and in man at rest and during exercise natural breathing takes place at frequencies approximating the second optimum. From additional observations on the effects of changing the mechanical characteristics of the respiratory system on respiratory frequency it is concluded that the principal site of the sensory end of the control mechanism is in the lungs.

Submitted on November 19, 1959
Catecholamine excretion in men exposed to cold
Authors: Arnett Elizabeth L. , Watts Daniel T.
Published: December 2017

Male subjects were subjected to a cold stress of 6.5°C for 1 hour. One-hour urine samples were collected in acid immediately before and after the exposure. Physiological responses such as blood pressure, body temperature, pulse rate and pupil size were recorded under this hypothermic stress. Epinephrine and norepinephrine were extracted from the urine and determined fluorometrically. In addition, the epinephrine concentration was determined by a specific bio-assay method with the rat uterus. A significant increase in excretion of these amines was found by both methods; a more marked increase was noted for epinephrine. It was concluded that the secretion of these amines is involved in the chemical control of heat production during exposure to cold.

Submitted on July 6, 1959
Preservation of viable bone marrow cells by freezing
Authors: Bender M. A. , Tran Phan The , Smith L. H.
Published: December 2017

In a study of low-temperature preservation, mouse bone marrow cells were slow-frozen and fast-thawed. A number of additives, including glycerol and other polyhydric alcohols, were tested for their ability to protect the cells against freezing and thawing damage. Effectiveness of thawed cells to promote recovery in lethally irradiated (900 r) mice was used as a measure of viability. Tyrode's solution, mouse serum, glucose, polyvinylpyrrolidone, dextran and bovine serum albumin gave little or no protection at the concentrations tested. Polyhydric alcohols and some sugars and other organic compounds were effective at certain concentrations. Results of tests of marrow frozen in 15% glycerol made after storage at various temperatures for various times indicate that liquid nitrogen temperatures give the best long-term storage. The eosin uptake test was found to be a poor assay of the effectiveness of thawed marrow samples.

Submitted on November 13, 1959
Central and peripheral control mechanisms of shivering and its effects on respiration
Authors: Lim Thomas P. K.
Published: December 2017

Central and peripheral contributions to the initiation of shivering have been studied in anesthetized dogs employing a thermal dissociation technique. Shivering was elicited invariably during differential cooling of the head or the trunk alone as well as in the course of whole-body cooling. Either ‘peripheral’ or ‘central shivering’ could be produced repeatedly and also inhibited by elevation of subcutaneous temperature in central shivering or brain temperature in peripheral shivering. In part 2 of this study, respiratory effects of shivering have been assessed during the steady state of hypothermia in the anesthetized animal. During shivering, O2 intake and CO2 output were doubled or tripled but the respiratory exchange ratio remained essentially unchanged. Total ventilation increased linearly with metabolic rate and yet arterial pH, pCO2 and buffer base revealed no significant changes with or without shivering. Although alveolar ventilation was increased almost three times, no marked alterations occurred in physiological dead space. Moderate hemoconcentration and a consistent elevation of pulse pressure were seen during shivering.

Submitted on October 11, 1959
Thermal and metabolic responses of Arctic Indians to moderate cold exposure at the end of winter
Authors: Elsner Robert W. , Andersen K. Lange , Hermansen Lars
Published: December 2017

Oxygen consumption, skin temperature and rectal temperature during nights of cold exposure were measured in eight Indian men from a remote arctic village who had been similarly studied the previous fall. The metabolic response of the Indians to cold exposure was similar in the spring to that observed in the fall studies. All subjects showed a general increase of about 30% in O2 consumption during the night. In addition, the basal metabolic rate of four subjects measured was slightly above the DuBois standards, as in the fall. A decline in rectal and skin temperatures throughout the night was observed to be similar to that of the same subjects in the fall, with the exception that the surface temperatures of arms and legs were slightly cooler in the spring. It was concluded that, except for a tendency toward heat conservation by cooling of extremities, no metabolic or thermal changes of a seasonal nature had taken place in these subjects during the arctic winter.

Submitted on November 12, 1959
Responses of Bushmen and Europeans on exposure to winter night temperatures in the Kalahari
Authors: Ward Joan S. , Bredell G. A. C. , Wenzel H. G.
Published: December 2017

Eight Bushmen and five Europeans were exposed during winter nights in the Kalahari desert to temperatures ranging from about 27°C to 2°C. Oxygen consumption and skin and rectal temperatures were measured over the period of 1frac12–2 hours of exposure. Comparison of increased metabolic rate with decreasing air temperatures measured in this study is made with similar data on young Norwegians. Bushmen and Europeans respond in a similar manner metabolically to the degree of cold stress experienced. Skin temperatures of the former tend to be lower and metabolism greater than in Europeans. The lower metabolic rate of Europeans is concluded to be due to the greater insulation afforded by their considerably larger subcutaneous fat deposits. These findings on the cold response of Bushmen contrast with those on Australian aborigines in comparable environmental conditions.

Submitted on January 4, 1960
Some membrane properties of the effector in the galvanic skin response
Authors: Edelberg Robert , Greiner Theodore , Burch Neil R.
Published: December 2017

Several membrane-like properties of the effector in the galvanic skin response (GSR) have been measured in humans by comparison of activity at a control site with that of a site subjected to changes of external chemical environment or changes in direction or density of imposed current. Comparison of inorganic chlorides shows that small cations, e.g. K+, may reversibly reduce GSR amplitude and R by 40%; larger cations, e.g. Ca++, increase GSR by several hundred per cent, while at the same time reducing basal resistance (R). GSR and R are reduced by acids and alkalies and by detergents. The effector is a poor rectifier, but there is a pronounced effect of polarity of current on the amplitude of the GSR in the case of large cations or anions combined with smaller ions of opposite charge. Current densities beyond 11 μamp/cm2 produce an ‘injury’ effect manifested in GSR and apparent resistance. These results have been interpreted in terms of an active superficial membrane having a relatively low charge.

Submitted on August 3, 1959
Use of clothing records to demonstrate acclimatization to cold in man
Authors: Goldsmith R.
Published: December 2017

Eight men lived for a year under considerable cold stress, doing hard physical outdoor work for much of the time. Observations of clothing worn and records of comfort vote were made, together with records of environmental conditions. There was a reduction in the number of layers of clothes worn in the last quarter of the period as compared with the first. A comparison between days of equal windchill in the first and second half of the period also showed significant reduction in the clothing assemblies. It is concluded that during a period of prolonged cold stress men do acclimatize to the cold, and this is manifested by a voluntary reduction in the amount of clothing they wear.

Submitted on October 29, 1959
Lung volume, alveolar ventilation and perfusion interrelationships in chronic pulmonary emphysema
Authors: Briscoe W. A. , Cree E. M. , Filler J. , Houssay H. E. J. , Cournand A.
Published: December 2017

In 10 patients with chronic pulmonary emphysema the distribution of ventilation within the lungs was assessed by a nitrogen washout and washin technique. Alveolar ventilation per minute per unit lung volume had a mean value of 5.0 in well ventilated alveoli and 0.19, or 1/26 as much, in poorly ventilated alveoli. Distribution of blood perfusion was estimated by a new method from these data and from O2 consumption and arterial O2 saturation. On the average, poorly ventilated alveoli which constituted 66% of lung volume were perfused by not more than 52% of the cardiac output. Thus poorly ventilated alveoli were underperfused by blood. Ventilation/perfusion ratios averaged 2.24 in well ventilated alveoli and 0.23 in poorly ventilated alveoli. Oxygen saturation averaged 85% in arterial blood and 97frac12% and 76%, respectively, in end-capillary blood leaving well and poorly ventilated alveoli. Inhomogeneity of this degree within the lung invalidates calculations of diffusing capacity based on any single mean PaOO2 and of alveolar ventilation based on identification of mean alveolar Pco2 with arterial blood Pco2.

Submitted on March 25, 1960
Unanesthetized dogs with increased respiratory dead space
Authors: Barnett Thomas B. , Peters Richard M.
Published: December 2017

A method is described for maintaining a permanent tracheostomy in dogs. This animal preparation has been used to study the effects of artificially increased respiratory dead space. Trained dogs with tracheostomies have made possible measurements of ventilation without anesthesia. It has been found that additions to the respiratory dead space in the form of tubing of frac34 in. i.d. result in an increase in physiologic dead space of the same magnitude as the volume of tubing added. Increasing the dead space in this manner resulted in an increased minute volume which was accomplished principally by an increase in tidal volume without a significant or consistent change in respiratory rate. Alveolar ventilation remained unchanged even with large additions to the dead space (20–30 cc/kg of animal wt.). Arterial pCO2 was significantly higher in these animals than in the controls. The CO2 tension was similarly elevated when extra dead space of lesser volume (5–20 cc/kg) was allowed to remain on the dogs for more than 48 hours.

Submitted on April 13, 1960
Cardiogenic oscillations in expired nitrogen and regional alveolar hypoventilation
Authors: Langer Glenn A. , Bornstein Donald L. , Fishman Alfred P.
Published: December 2017

The plateau of the single-breath nitrogen curve shows rhythmic oscillations in the concentration of nitrogen. In the present study, the mechanisms involved in the genesis of these oscillations were investigated by varying the composition of the inspired gases and by different respiratory maneuvers. The oscillations were shown to be altered in a characteristic and predictable way in subjects with particular diseases of the heart and lungs. The conclusion is reached that these oscillations represent a combination of uneven alveolar ventilation and vascular impacts; however, the ‘poorly ventilated’ areas are thought to be located in the parahilar, rather than in the peripheral, regions of the lung.

Submitted on January 4, 1960
Respiratory sinus arrhythmia: laws derived from computer simulation
Authors: Clynes Manfred
Published: December 2017

Dynamic mathematical relations describing respiratory sinus arrhythmia were derived through analogue computer simulation. If a signal proportional to thorax circumference is fed into the analogue computer, it calculates with differential equations the complex heart rate changes in real time and records them along with those of the real heart. Close correspondence of the predicted and actual changes of heart rate for a wide variety of modes of breathing, and for different individuals, proves the validity of the nonlinear differential equations describing the phenomenon. The respiratory effects are shown to be caused by two separate reflexes each producing biphasic heart rate transients in the same directions. The observed effects are the result of superposition of those transients. Previous paradoxical results in attempting to relate heart rate to respiration on a steady-state, nondynamic basis are thus explained. The laws indicate that stretch receptors and not hemodynamic or central nervous factors initiate the changes in heart rate. The analysis also allows heart rate effects of exercise and emotional stresses to be more precisely perceived, as clearly separated from respiratory effects.

Submitted on June 16, 1959
Effect of nutrient supplements during work on performance capacity in dogs
Authors: Young D. R. , Schafer N. S. , Price R.
Published: December 2017

The effect of consuming fluid supplements during work on maximum performance capacity has been examined in the dog. Within the range of 0–1.6 1. of water, maximum work energy expenditure was a positive function of the fluid intake. Intake of water in excess of 2 l. did not further increase work capability. Additional tests were undertaken to study the effect of nutrient supplementation during work on performance capacity. Whole milk with added copper and iron was used as the control to study the comparative effect on performance of providing either no supplement, water, or separately pure solutions of lactalbumin, glucose, phospholipids, or water-soluble vitamins (exclusive of ascorbic acid. Consumption of milk, vitamins, and phospholipids led to a significant reduction (–54%) in work capability. The intake of glucose or protein was neither beneficial nor detrimental. The cardiorespiratory responses and blood chemistry changes were for the most part unrelated to variations in performance.

Submitted on July 5, 1960
Physiology and morphology of blood coagulation in polycythemia vera
Authors: James Thomas N. , Johnson Shirley A. , Monto Raymond W.
Published: December 2017

The observation that red cells fall out of the clotted blood in polycythemia vera has been documented previously. This phenomenon appears in all patients with initial thrombocytosis but continues to occur even when the red cell mass and platelet numbers come under control. The only known coagulation defect is a pronounced reduction of platelet factor 3 in the platelets. In this investigation, platelet-plasma clots from normal individuals and polycythemia vera patients were sectioned and stained at various intervals during coagulation and clot retraction. Great disorganization of the platelet-fibrin network was observed in the polycythemia vera clots when compared with the normal clots, and it was apparent that the red cells could easily slip through the openings in the network.

Submitted on July 11, 1960