bluuebunny/crossref_metadata_2025_split huggingface dataset:
Respiratory quotients of human kidney in vivo
Authors: Barker Earl S. , Crosley Archer P. , Clark John K. 
Published: December 2017

Renal respiratory quotient (RQ) has been calculated from data collected in unanesthetized human subjects. In contrast to RQ recently reported on anesthetized dogs, these data do not indicate a mean value greater than 1. Under control conditions in 24 subjects, renal RQ calculated without special corrections averaged 0.88. Correcting for differences in blood flow between renal artery and vein due to urine formation the mean was 0.73, with 95% confidence limits 0.49–0.97. With alkaline urines an additional correction for urinary excretion of CO2 is advised. Excluding procedures known to alkalinize the urine, RQ values were similar in 46 observations after a variety of experimental procedures. Since both numerator and denominator of the ratio involve small differences between large values, small analytical errors can produce large changes indistinguishable from physiologic variation. Therefore mean values rather than individual observations are stressed. While such values in our data appear similar to RQ for other organs and the whole body, they do not preclude considerable anaerobic metabolism. Submitted on August 9, 1962
Regional relationship of water vapor pressure of human body surface
Authors: Ohara Kokichi , Ono Takeo 
Published: December 2017

A new simple method for measurement of water discharge from the skin, as well as for estimation of absolute and relative humidity of the skin surface, was reported. The accuracy of the method was high with errors in the order of 2.5%. Estimations were made, using this method, at 108 points over the body of a young healthy nude male subject under neutral thermal conditions. Regional relationship of the rate of insensible perspiration, as well as the absolute and relative humidity of the skin surface, were obtained from the experiments. There was no difference between the regional relationship of the insensible perspiration and that of the absolute humidity. In the regions where perspiration rate is high, the water vapor pressure of the skin surface is also high. Sole, face, palm, and neck are the highest regions. Back of hands and gluteal region are the second highest zone. In distal parts of extremities, there exists an increasing gradient toward the palm or the sole. In the median region of the chest and epigastrium the values are somewhat higher though the chest and abdomen as a whole belong to the lowest regions. Distribution of the relative humidity showed no great difference in general from that of the perspiration rate or absolute humidity. It was found that the regional relationship is not perfectly symmetrical in both sides of the body. Submitted on January 16, 1963
Application of signal analysis methods to arterial and aortic pressure curves
Authors: Henley Ernest J. , Lukas Daniel S. , Staffin H. Kenneth , Staffin Robert 
Published: December 2017

Brachial and aortic cardiovascular pressure waveforms taken from the literature and from New York Hospital patients were subjected to Fourier analysis to determine the harmonic spectrum. The computation, which was performed on a specially constructed analogue computer (Procedyne Associates model 101A) consisted of evaluating the integral (See PDF) The complex transform, F(omega), was analyzed in terms of gain and phase by means of Bode and Nyquist diagrams. The preliminary data show that frequency response techniques may be a useful aid in diagnosing heart disease. In contrast to the normal or mildly defective hearts, the subjects with serious aortic stenosis show pulse waveforms which a) have less high frequency components, b) have no nodes or missing frequencies which are multiples of the fundamental frequency. The paper points to several ways in which advanced signal techniques and control theory can be applied to medical problems. Bode plot; Fourier transform; harmonic analysis; frequency spectrum; pulse pressure curves; Nyquist diagram; aortic stenosis Submitted on September 14, 1962
A servomechanism to control output of an artificial ventricle
Authors: Pierce William S. , Burney Robert G. , Williams Kirkley R. , Kirby Charles K. 
Published: December 2017

A servomechanism has been designed and built for controlling the output of an artificial ventricle. Venous pressure was selected as the primary parameter of control because of experimental and clinical studies which report this mechanism to assume control under certain conditions in which neural and/or hormonal control mechanisms are attenuated. In this control system, venous pressure, as measured with a pressure transducer, is compared to an “ideal” venous pressure, usually 0 mm Hg. An error signal is thus generated, amplified, and integrated with respect to time. The integrated error signal is fed into a programable d-c power supply. The power supply output runs a small, positive-displacement artificial ventricle. The pump output is controlled by setting the venous pressure. Studies in a mock circulation setup in which venous return was varied over a wide range demonstrated how either blood loss or pooling of blood in the periphery will lead to a diminished ventricular output while the venous pressure is maintained at the same level. This situation has its clinical analogues. It is anticipated that the use of two such venous pressure-controlled artificial ventricles as a heart replacement in the experimental animal will permit changes in heart output in accord with tissue demands both at rest and during exercise. venous pressure regulation Submitted on February 28, 1963
Response to cold of Eskimos of the eastern Canadian Arctic
Authors: Brown G. Malcolm , Semple Robert E. , Lennox C. S. , Bird G. S. , Baugh C. W. 
Published: December 2017

Skin, muscle, and rectal temperatures, and O2 consumption of Eskimos and Caucasians have been compared during an acute cold exposure involving immersion of one hand and forearm in a 5 C water bath. The Eskimos consumed less O2, maintained their rectal temperatures at a higher level, and gave up less heat from the muscles of the limbs. Though the Eskimos had significantly more adipose tissue, average skin temperatures were the same in the two groups. The pattern of temperatures noted now and the previously observed higher blood flow in the hand and forearm of Eskimos point to increased cooling of arterial blood by returning venous blood in the extremities with resultant preservation of heat in the body core. Submitted on August 6, 1962
Relationship of radius to pressure along the aorta in living dogs
Authors: Patel Dali J. , De Freitas Flavio M. , Greenfield Joseph C. , Fry Donald L. 
Published: December 2017

The instantaneous pressure-radius relationship and mean dimensions were studied at various sites along the aorta in 30 dogs. The pressure-radius relationship was studied in the living state using an electrical caliper to measure the radius continuously through the cardiac cycle. The relative dimensions of the aortic tree at branching sites were calculated from Jeltrate casts made immediately post mortem. The results indicate: 1) The value of ΔR/ΔP and the mean radius decreased with distance along the aorta. 2) The calculated value for Ep, the “pressure-strain elastic modulus” increased monotonically from the ascending aorta to the bifurcation. 3) An “average” arterial tree was constructed from the mean values of the radius obtained from the caliper data and the branching ratios obtained from the casts. elastic properties, aorta; dimensions, dog aorta Submitted on March 5, 1963
Respiratory control at high altitude suggesting active transport regulation of CSF pH
Authors: Severinghaus J. W. , Mitchell R. A. , Richardson B. W. , Singer M. M. 
Published: December 2017

The role of CSF pH and HCO–3 ion in stimulating respiration was studied in four men during acclimatization from sea level to 3,800 m for 8 days. Mean values for sea level control, 2nd day and 8th day at altitude were, for CSF 7.328, 7.338, and 7.336, and for arterial blood 7.424, 7.485, and 7.484. Ventilatory response to four levels of alveolar CO2 was determined while subjects breathed high oxygen to eliminate peripheral chemoreceptor drive, and for each value of PaCOCO2, arterial and CSF pH were computed. The displacement of the ventilation response curves at altitude from the sea level curves was: -10 mm Hg PaCOCO2, + 0.06 pH unit for arterial blood, but -0.01 for CSF pH. CSF HCO3 was 4–5 mEq/liter lower than control within 1–2 days at altitude, whereas renal buffer base excretion only reduced blood standard bicarbonate 1 mEq/liter after a week. CSF chloride and lactate rose about 6 and 1 mEq/liter. Thus, medullary respiratory chemoreceptor drive, initially reduced at altitude by hyperventilation alkalosis, is restored to normal during acclimatization by reduction in CSF HCO3, the incremental ventilatory drive being supplied by peripheral chemoreceptors. The blood-CSF barrier appears to respond to the initial hyperventilation alkalosis by actively reducing CSF HCO3; the data suggest that CSF pH is thus regulated by active transport by the blood-CSF barrier. altitude acclimatization; blood brain barrier; regulation of respiration Submitted on December 17, 1962
Responses of cold-acclimatized men to infused norepinephrine
Authors: Joy Robert J. T. 
Published: December 2017

Nine healthy males were infused with norepinephrine (o. μg/kg min) for 20 min before and after five 40-hr weeks of seminude exposure to 5 C. All infusions were given in the basal state, in a quiet room at 27 C, after a 30-min period of control measurements. Rectal temperatures and respiratory rates were unchanged either by the drug or the intervening cold exposure. The drug increased respiratory minute volumes and tidal volumes and decreased heart rates, but equally so in both experiments. Mean skin temperatures were unaffected by the drug but were significantly (P < .025) higher after cold exposure (mean 1 C). Both basal and drug-induced increase above basal of systolic and diastolic blood pressures was significantly lower (P < .025) after cold exposure. Oxygen consumption was the same in both basal periods and was unaffected by the drug before cold exposure. After cold exposure, norepinephrine produced a significant (P < .025) increase in oxygen consumption (mean 18 cc/min m2). These results show a changed sensitivity to norepinephrine in cold-exposed men, with a decrease in vasopressor response and the development of a calorigenic response. The data suggest that in men, norepinephrine may be a mediator of a nonshivering thermogenesis occurring with cold acclimatization. Note: (With the Assistance of Joseph C. Matone, Gerald W. Newcomb, and Wendell C. Bradford) cold exposure; catecholamines; norepinephrine calorigenesis; nonshivering thermogenesis Submitted on May 2, 1963
Continuous infusion in rats
Authors: Kennan A. L. 
Published: December 2017

A simple method of continuous intravascular infusion is described that involves little trauma and is tolerated by pregnant rats. The mechanism is a polyethylene catheter in the tail vein, an accommodating cage in which the rat can move freely, and a mercury U tube to provide pressure for infusion. The method has several advantages in that extensive surgery is not required, the animal can be conditioned to the cage before placement of the catheter, infusion under pressure is possible, and the apparatus is simple and can be set up in any laboratory with equipment at hand. pregnant rat; catheter; cage Submitted on May 31, 1963
Binding of calcium by human plasma proteins under simulated physiologic conditions
Authors: Held Irene R. , Freeman Smith 
Published: December 2017

The binding of calcium to human plasma albumin, alpha, beta, and gamma globulins was studied with the aid of an ultracentrifuge. The amount of calcium bound to these separated proteins was determined in solutions with electrolyte concentrations and pH within physiological ranges. The total calcium concentration was 2.35–2.90 mm/liter H2O and the total protein concentration was 3.91–4.29 g/100 ml H2O. In these solutions no significant differences were found for the binding of calcium (expressed as mm Ca++ bound per gram protein) by albumin, alpha, and beta globulins; the average values obtained were, respectively, 0.016, 0.018, and 0.023. Significantly less calcium was bound by gamma globulin; 0.009 mm/gram. The pH was varied between 7.200–7.550 and the sodium chloride concentration between 114–157 mEq Na per liter. These changes did not measurably affect the amount of calcium bound to albumin. protein-bound calcium; ultracentrifugation and determination of protein-bound calcium; plasma globulin-bound calcium; plasma albumin-bound calcium Submitted on July 2, 1963
Oxytocin effect on myoepithelium of the breast throughout pregnancy
Authors: Wiederman Joseph , Freund Matthew , Stone Martin L. 
Published: December 2017

Sensitivity of the myoepithelium of the human breast to oxytocin during gestation has been evaluated in terms of threshold, threshold intensity, threshold lag period, dose response, slope of dose response, and multiple responses. A correlation of these data with advance in gestation was sought. Thresholds, threshold intensities, and threshold lag periods did not vary with age of gestation. Threshold lag periods were inversely proportional to the amplitude of the ensuing response, while amplitude of response was directly proportional to the log of the dose of oxytocin. Slopes of dose response did not vary with gestational age. Spontaneous myoepithelial contractions were found to occur in patients during gestation. Increasing sensitivity (magnitude of response at a given dose) to oxytocin, as found in the uterus, was not evident in the breast during gestation. myoepithelial contractility; breast during gestation; mammary gland contractile response Submitted on May 23, 1963
Conduction velocities along course of ulnar nerve
Authors: Schubert Herbert A. 
Published: December 2017

The left ulnar nerve was tested on 20 normal subjects on two occasions several weeks apart to determine the motor velocities along various points over the course of the ulnar nerve. Analysis showed that there is no practical difference between proximal and distal motor velocities of the normal ulnar nerve. An approximation of reduced velocity peripheral to the most distal stimulus point can be reflected in the residual latency calculation. Velocity determinations done with stimuli points closer than 10 cm and/or with stimuli at points where the nerve trunk is not superficial are subject to considerable error. residual latency; motor velocity of ulnar nerve; axonostenosis Submitted on October 15, 1963
Plasma free fatty acids in exercise
Authors: Rodahl K. , Miller H. I. , Issekutz B. 
Published: December 2017

The effects of exercise of different intensity and duration on plasma free fatty acids (FFA), blood glucose, and lactate were investigated in eight healthy young men. In heavy 10-min work the blood lactate rose rapidly and the FFA decreased. Blood sugar showed no marked change. Intermittent work caused a slight increase in blood lactate and no change in blood glucose. The FFA remained essentially unchanged but increased in three out of four subjects during recovery. In moderate 1-hr work the FFA remained essentially unchanged, but increased markedly during recovery when blood lactate had returned to resting levels. In prolonged exhausting work in fasting subjects, the blood lactate remained almost unchanged, while the FFA rose steadily and the blood sugar dropped. In nonfasting subjects the FFA also rose, but the ingestion of lunch caused, in all cases, a striking drop in the FFA, associated with a rise in blood sugar. Combined hormonal effects (insulin and norepinephrine) brought into play during exercise of different intensity and duration may well explain the apparent discrepancy in the results of different investigators concerning the effect of exercise on plasma FFA. work and FFA; FFA at different workloads; lipid metabolism in work Submitted on November 6, 1963
Physiological reactions to cold of men in the Antarctic
Authors: Wyndham C. H. , Plotkin R. , Munro A. 
Published: December 2017

The physiological reactions to cold of five members of the 1961–1962 South African expedition to the Antarctic were studied in a climatic chamber in Johannesburg, and again after 6 months and after 12 months in the Antarctic. Their results were compared with the results of a control group in Johannesburg. The predeparture results were within the 95% significance intervals of the control group. After 12 months in the Antarctic their results fell outside the 95% significance intervals of the control group when at 5 C air temperature, metabolism, average skin temperatures, rectal temperatures, and finger temperatures were all significantly lower. Toe temperatures, however, were higher. There appeared to be a gradual “adaptation” and general “toughening” to the cold, because the subjects shed their clothing progressively until they could run about naked in the snow. The values at the thermoneutral zone of 27 C did not change over the 12 months, however. It is therefore concluded that it is unlikely that the changes in physiological responses were of endocrine origin. cold adaptation in Antarctic; metabolic and body temperature reactions to cold Submitted on August 16, 1963
Balance and kinetics of anaerobic energy release during strenuous exercise in man
Authors: Margaria R. , Cerretelli P. , Mangili F. 
Published: December 2017

The speed of lactic acid formation in blood has been measured in man as a function of the intensity of exercise and was found to reach a maximum of about 36 mg lactic acid/liter blood per sec, corresponding to about 21.5 kcal (kg hr) or 0.034 hp/kg. The maximal energy release sustained by the alactacid mechanism is of the order of 45 kcal/(kg hr), or 0.07 hp/kg. The alactacid debt, as measured in man running on a treadmill, seems to be approximately proportional to the energy expenditure: it amounts at most to 0.1 kcal/kg or about 1.4 liters O2 for a man weighing 70 kg. The lactacid debt amounts at most to 0.22 kcal/kg or about 3 liters O2 for man, on the average. The alactacid oxygen debt contraction is a faster process and it requires 10–30 sec for completion, while the lactacid debt process is completed in about 40 sec in the most strenous exercise. Therefore, at the highest workloads, the only energy source available after 40 sec resides in oxidative processes. oxygen debt; lactic acid Submitted on July 5, 1963
Functional adaptation to rigorous training and exercise in diabetic and nondiabetic adolescents
Authors: Larsson Yngve , Persson Bengt , Sterky Göran , Thorén Claes 
Published: December 2017

Functional adaptation to training and exercise was studied in six diabetic and six nondiabetic boys, 15–19 years of age. The training program consisted of 5 months' regular physical activity with stepwise increasing intensity. At the end of this period the subjects took part in a cross-country ski run, lasting for 3–4 hr and repeated on 3 consecutive days. Exercise tests were made at regular intervals with both submaximal and maximal workloads and work capacity was expressed as maximal oxygen uptake (max Vo2). At the beginning of the study the diabetic boys had lower functional capacity than the controls, but during training the max Vo2 as well as heart volume increased similarly and significantly in both groups. At submaximal workload the lactate concentration was the same among the diabetics as in nondiabetics, but at exhaustion it was somewhat lower in the former group. The caloric intake increased substantially (ca. 50%) in all subjects but during the actual work hours the carbohydrate intake was greater among the diabetics than among the controls. Glycosuria in the diabetic group was approximately unchanged during the whole study. All subjects could fulfil the work, and there were no untoward effects of exhaustion. In the diabetic group insufficient caloric supply and the concomitant risk of hypoglycemia seemed to be the most important limiting factor for prolonged heavy work, but the responses and adaptation of pulmonary and cardiovascular functions were adequate and similar in both groups. juvenile diabetes; prolonged exercise; exercise tests; maximal oxygen uptake; blood lactate; caloric intake Submitted on October 23, 1963
Etherőair anesthesia for small experimental animals
Authors: Walker F. W. 
Published: December 2017

An apparatus using compressed air for the semiquantitative administration of ether-air mixtures to experimental animals has been constructed in quantity from bottles, polyethylene tubing, and roller clamps available from hospital discard. Ether concentrations at various flow rates can be derived from the depression of the partial pressure of oxygen in the ether-air mixture. Inexpensive and useful in research, the apparatus also acquaints the student with the quantitative aspects of inhalation anesthesia. anesthetic apparatus for experimental animals; ether vapor concentration calculated from pO2 in ether-air mixtures Submitted on June 10, 1963
Chart viewer
Authors: Lentini E. A. , Guyton W. V. 
Published: December 2017

An inexpensive chart viewer was constructed to facilitate analyses of oscillographic records obtained through the use of the electronic micrometer. The viewer was designed to meet the criteria of economy, compactness, measuring versatility, simple electrical design, variable speed control, and smooth operation. A variety of oscillographic records can be analyzed by using this instrument. It is easy to operate and structurally sturdy. oscillographic record analyzer; mechanical viewer; electrical chart roller Submitted on February 27, 1964
Reduction of retroactive effects of interpolated maze training in hypothermic mice
Authors: Essman Walter B. , Sudak Frederick N. 
Published: December 2017

In two experiments the retroactive effect of maze training interpolated between an initial acquisition phase and a testing phase was determined in mice. In the first experiment a retroactive inhibitory effect was demonstrated in animals given interpolated training for the reversal of an acquired maze response. In the second experiment the interpolated activity was either habit reversal, overtraining, or practice swimming. When the interpolated activity was initiated in the presence of hypothermia habit reversal did not occur, no retroactive inhibition was shown, and facilitation of performance from overtraining or practice swimming was negated. The data support the hypothesis that hypothermia maintained during maze training reduces the negative (retroactive inhibition) as well as positive (facilitation) effects that such training has upon the performance of a previously acquired maze habit. maze learning in mice; maze acquisition during hypothermia; hypothermia and interpolated maze training; animal behavior; learning in hypothermic animals; hypothermia and maze acquisition Submitted on January 16, 1964
Collateral ventilation in excised dog lungs
Authors: Nakamura T. , Takishima T. , Takasugi R. , Sasaki T. 
Published: December 2017

Lobes of excised dog lungs were cannulated so that all segmental bronchi were connected to one of two cannulae. When one cannula was obstructed all ventilation beyond the point of obstruction was through collateral passages. Changes in effective lobar compliance with cycle duration, and changes in the lobar spirograms following abrupt changes in translobar pressure were interpreted in terms of underlying changes in collateral flow. In lobes from six dogs collateral flow was not detected in two and showed marked individual variations in the other four. It decreased relative to total lobar flow when the duration of the imposed volume cycle was decreased, and it increased when the degree of lobar inflation was increased. The latter finding suggested associated increases in the size of the stomata between adjoining alveoli. effective lobar compliance; stomata Submitted on September 11, 1963