bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heart rate and forward acceleration
Authors: Steiner Sheldon H. , Mueller Gustave C. E. 
Published: December 2017

Cardiac rate was measured in six human subjects during forward acceleration at 8 g and compared with changes in head position while maintaining the remainder of the body in the same position. There was no change in cardiac rate for the 20-sec duration of the plateau with the head in a neutral position (fully supine). The heart rate increased 20% with the head elevated and decreased 16% with the head depressed. Changes in rate are produced by altering the position of the carotid baroreceptors in relation to those located in the trunk, presumably due to alterations produced by acceleration forces in the perfusion pressures in the carotid arteries. Submitted on February 27, 1961
Maximal oxygen uptake and heart rate in various types of muscular activity
Authors: 0&Aring;strand Per-Olof , Saltin Bengt 
Published: December 2017

Seven subjects performed maximal work of various types. The following exercises were studied: a) cycling a bicycle ergometer in a sitting and b) supine position, c) simultaneous arm and leg work on bicycle ergometers, d) running on a treadmill, e) skiing, f) swimming, and g) arm work (cranking). Vo2 was a few per cent higher in running uphill than in cycling ( a), cranking plus cycling ( c), and skiing, in which events similar values were attained. Heart rate was similar in those types of exercise mentioned ( a, c, d, e). Supine cycling ( b) gave a maximal Vo2 that was about 15% lower than in sitting cycling. A similar reduction in maximal Vo2 was noted in swimming. Maximal work with the arms ( g) gave an oxygen uptake that was about 70% of maximal Vo2 when cycling ( a). It is concluded that the aerobic capacity and maximal heart rate are the same in maximal running or cycling, at least in well-trained subjects. Submitted on June 23, 1961
Respiration in man during metabolic alkalosis
Authors: Stone Daniel J. 
Published: December 2017

A steady state metabolic alkalosis was induced in two subjects over a period of several days utilizing oral sodium bicarbonate in dosages of 50 g/day. The purpose of inducing steady state metabolic alkalosis was to study the effects of such a state on the respiratory center responses to inspired gas mixtures, containing carbon dioxide, and to contrast these results with the control studies. The experiment was so designed that the arterial pH in both subjects tended to return toward normal in the presence of significant increases in blood bicarbonate. Repeated study of ventilation responses with room air and 4% and 6% carbon dioxide in inspired air revealed a definite and significant decrease in ventilation response to carbon dioxide during the periods of steady state alkalosis as compared to the control periods. Normal responses returned after some time lag. A consistent rise in paCOCO2 occurred with alkalosis, thus demonstrating respiratory compensation. In neither subject was total lung function or gas exchange affected by the alkalosis. The experiment was confirmed on several occasions with reproducible results. Note: (With the Research Assistance of Mary Di Lieto) Submitted on May 22, 1961
Circulatory adjustment in pearl divers
Authors: Scholander P. F. , Hammel H. T. , LeMessurier H. , Hemmingsen E. , Garey W. 
Published: December 2017

A seemingly general feature in the adjustment to diving in various mammals, birds, and reptiles is a slow-down and redistribution of the circulation, leaving muscles, periphery, and certain visceral organs with a markedly reduced circulation. This saves oxygen and causes widespread reduction of the energy metabolism. Active as well as quiet diving develops bradycardia without drop in central blood pressure, and lactic acid forming in the muscles during the dive floods the blood when breathing starts. In 31 native skin divers in Australia, diving rarely exceeded 1 min. During the dive, blood pressure stayed normal while heart rate dropped to half; blood lactate (five divers) remained normal but showed an acute rise in the recovery. Evidently humans utilize an adjustment similar to animals. Most of our divers developed various cardiac arrhythmias during the dive, persisting sometimes into the beginning of the recovery. This asphyxial defense seems developed at birth, for fetal bradycardia is common during delivery, and an acute rise of lactic acid after delivery has recently been described. Phylogenetically the mechanism is ancient, for it is found also in fishes when taken out of water. Submitted on August 7, 1961
Carbon dioxide and acid-base transients during hyperventilation
Authors: Tomashefski Joseph F. , Carter Earl T. , Lipsky Joseph A. 
Published: December 2017

Studies were conducted on ten healthy adult males subjected to mechanically induced hyperventilation. Total ventilation was increased approximately 300%. This resulted in a mean arterial carbon dioxide tension decrease to 20 mm Hg and a mean pH increase to 7.60. Observations of the dynamic shifts in carbon dioxide stores were made for a 12-min period after onset of hyperventilation. The total carbon dioxide elimination was determined and compared to the basic metabolic CO2 production to permit estimation of body carbon dioxide depletion. The total carbon dioxide elimination was partitioned into that coming from the tissues, the blood, the lung parenchyma, and the alveolar air. After the abrupt increase in alveolar ventilation, a significant portion of the expired carbon dioxide comes from the lung tissue store and the alveolar gas compartments; this is approximately 140 cc and is eliminated in the first 3 min. After 3 min most of the expired carbon dioxide can be accounted for as coming from blood and tissues. Submitted on August 9, 1961
Effects of acute controlled exposure to SO2 on respiratory mechanics in healthy male adults
Authors: Frank N. Robert , Amdur Mary O. , Worcester Jane , Whittenberger James L. 
Published: December 2017

Eleven healthy, adult, male volunteers were exposed on separate occasions to average levels of sulfur dioxide of 1, 5, and 13 ppm. The subjects were seated in a body plethysmograph, breathing spontaneously by mouth while measurements of respiratory mechanics were made with an esophageal catheter. Exposures lasted 10–30 min and, for each subject, were spaced at least 1 month apart. With one exception the group showed no significant increase in pulmonary flow resistance at the lowest concentration of gas. At both 5 and 13 ppm, flow resistance was elevated, the change being greater at 13 ppm. The change occurred within 1 min of exposure, increased after 5 min but, on the average, showed no further change after 10 min. Four subjects were exposed to 5 or 13 ppm of SO2 for 30 min without exhibiting increases in flow resistance beyond the 1st 10 min. There were no consistent changes in pulmonary compliance, tidal volume, breathing frequency, or pulse rate. The functional residual capacity increased slightly during exposure to 13 ppm. Note: (With the Technical Assistance of Eleanor Root) Submitted on May 24, 1961
Comparison of two iminodibenzil derivatives on restraint-induced ulcers and gastric secretion
Authors: Bonfils S. , Dubrasquet M. , Lambling A. 
Published: December 2017

Imipramine [N-(γ-dimethylaminopropyl)-iminodibenzyl HCl] was effective in reducing both the incidence of ulcers induced by several different intensities of restraint stress and the volume and acidity of gastric secretion in the rat. G 31.002 [N-(γ-dimethylaminoisopropyl)-iminodibenzyl HCl], a close congener of imipramine, was studied at comparable doses, but did not alter ulcer incidence or reduce gastric secretion. Since both drugs have similar central nervous system depressant activity, the data suggest that the antiulcer effect of imipramine is due to a direct action on the stomach. Submitted on May 22, 1961
Hematological changes in long-term perfusion
Authors: Brinsfield D. E. , Hopf M. A. , Geering R. B. , Galletti P. M. 
Published: December 2017

Hematological changes were measured in 14 dogs during partial heart-lung bypass procedures of 10 hr duration with an extracorporeal flow approximating 40% of the cardiac output. The changes occurring during the 1st hr of perfusion were identical to those previously reported for short periods of total heart-lung bypass, namely, thrombocytopenia and leukopenia. Later on, however, compensatory mechanisms were manifested by the appearance of a leukocytosis with a shift to the left, a leveling off of thrombocyte counts, and the appearance of nucleated red cells in the peripheral blood. Bone marrow studies revealed stimulation of myeloid tissues. These compensatory responses observed during perfusion were similar to changes which have been described as typical of the postperfusion period after shorter durations of extracorporeal circulation. The trauma inflicted on erythrocytes during extracorporeal blood handling became evident after perfusion as a marked anemia and an increased mechanical fragility of the red cells. Submitted on September 22, 1961
Energy cost of load carriage
Authors: Goldman R. F. , Iampietro P. F. 
Published: December 2017

The relative contributions of rate of progression (1.5–4.0 mph), grade (3–9%), and load (10–30 kg) to total energy cost were determined. The data obtained were integrated graphically with some of the available energy cost data in the literature to provide a useful graph for estimating energy expenditure. It was tentatively concluded that for grade walking over the ranges studied, the energy cost per unit weight is essentially the same whether the weight is of the body or the load. Submitted on January 8, 1962
Myocardial energy substances in the dog heart during potassium and hypothermic arrest
Authors: Gott Vincent L. , Bartlett Marilyn , Long David M. , Lillehei C. Walton , Johnson John A. 
Published: December 2017

Canine hearts were arrested with potassium citrate at 37 C and with cold blood at 17 C. Biopsies were taken from the nonperfused hearts at 0, 5, 20, and 60 min and analyzed by specific microtechniques for AMP, ADP, ATP, phosphocreatine, inorganic phosphate, glycogen, lactic acid, and pyruvic acid. During potassium citrate arrest at 37 C the ATP level was reduced 4.41 mmoles/kg to an average value of .77 mmoles/kg. During hypothermic arrest the ATP level decreased only 1.88 mmoles/ kg. Arrested hearts at 37 C utilized four times as much glycogen and produced three times as much lactic acid as hearts at 17 C. Phosphocreatine fell to low values in both types of arrest within 20 min. The levels of AMP, ADP, and pyruvic acid remained fairly constant throughout the period of arrest. It appears from this data and earlier human biopsy data that selective hypothermic arrest is tolerated far better than potassium citrate arrest. Submitted on September 18, 1961
Relative importance of various tissues in joint stiffness
Authors: Johns Richard J. , Wright Verna 
Published: December 2017

The rheological properties of the cat”s wrist were found to be similar to those of the human metacarpophalangeal joint. In the intact joint nonlinear elasticity and plasticity accounted for most of the stiffness, elasticity being twice as great as plasticity. Inertia accounted for <6% of the total torque, and viscosity <2%. Frictional torques were immeasurably small, being <0.1% of the total. The joint capsule contributed 47%, passive motion of the muscles 41%, the tendons 10%, and the skin 2% to the total torque required to move the joint in its midrange. Toward the extremes of joint motion the restraining effect of tendons became more important. Submitted on February 8, 1962
Tissue pO2 and pCO2 estimation with rat subcutaneous gas pockets
Authors: Van Liew Hugh D. 
Published: December 2017

This study appraises use of gas pockets for estimation of tissue pO2 and pCO2. a) Tensions of O2 and CO2 in rat subcutaneous pockets in the constant composition state were compared with tissue tensions estimated by a special interpolation technique using the pockets; the two types of results were not appreciably different. b) Possible values for venous blood pO2 and pCO2 were estimated by a “blood r” curve; agreement between expected blood tensions and gas pocket tensions supports the hypothesis that pockets closely reflect a tissue region's venous blood. c) Initial composition adjustments after introduction of five different mixtures of O2, CO2, and N2 into the pockets were studied; the results were used to illustrate some theoretical properties of gas pockets in the body. Submitted on April 23, 1962
Phenylalanine metabolism in control subjects, mental patients, and phenylketonurics
Authors: Sacks William 
Published: December 2017

After injection of dl-phenylalanine-1-C14 or l-phenylalanine-1-C14, C14O2 specific activities in whole blood were frac15–frac13 as high as those after injection of dl-tyrosine-1-C14 or l-tyrosine-1-C14 in normal subjects and chronic psychotic patients. In phenylalanine-C14 studies, tyrosine specific activities were 1/16–1/10 of corresponding phenylalanine specific activities. After injection of l-phenylalanine-1-C14 into two phenylketonuric (PKU) patients, C14O2 activities in one, a child, approximated those in other experiments, whereas they were lower in the adult PKU-patient. Maximal tyrosine specific activity (adult PKU patient) was frac16 the corresponding phenylalanine specific activity. Ratios of specific activities of maximal C14O2 to phenylalanine were similar in the control subject and PKU patient, suggesting that catabolism of phenylalanine proceeds at the same rate in phenylketonuria. Results with l-phenylalanine-U-C14 indicated that more than the carboxyl carbon contributed to blood 14O2. The data suggest that hydroxylation of phenylalanine to form tyrosine may be a minor pathway in intermediary metabolism of phenylalanine in normal humans and in chronic psychotic and phenylketonuric patients. Submitted on April 11, 1962
External work in walking
Authors: Cavagna G. A. , Saibene F. P. , Margaria R. 
Published: December 2017

From records obtained from a triple accelerometer applied to the trunk of a subject the displacements of the trunk in vertical, forward, and lateral directions have been calculated. With motion pictures taken simultaneously, displacements of the center of gravity within the body were measured. From these data the external mechanical work of walking was calculated. The sum of work for vertical and for forward displacements of the center of gravity of the body gives the total external work; energy for the lateral displacements was negligible. Total external work appears to be lower than that calculated from the vertical displacements alone, because work done in lifting is partly sustained by the inertial force of the forward-moving body. Total external work reaches a highest value (0.1 kcal/km kg) at the most economical speed of walking, 4 km/hr, which corresponds to an energy consumption of 0.48 kcal/km kg. At this speed the internal work appears negligible; it amounts to appreciable entities at very low speeds because of the static contractions of the muscles, and at high speeds because of considerable stiffening of the limbs and movements not involving a displacement of the center of gravity. Submitted on May 25, 1962
Hydraulic input impedance to aorta and pulmonary artery in dogs
Authors: Patel Dali J. , deFreitas Flavio M. , Fry Donald L. 
Published: December 2017

Pressure-flow relationships were studied at the root of the aorta and the pulmonary artery in 18 dogs. The hydraulic input impedance to the vascular bed was calculated as a complex ratio of the corresponding pressure and flow harmonics. Results indicate: a) The predominant features of the load against which the heart is pumping consists of an impedance with a magnitude that initially decreases rapidly with frequency and then increases gradually with frequency. In general, pressure tends to lag behind flow for all harmonics. b) The input impedance versus frequency patterns provided a logical basis for choosing various simple electrical networks which can be used to characterize in a compact manner the general features of the hydraulic load presented to the ventricles. c) The hazards of using such simple networks to define the physical properties of the vascular system are pointed out. Submitted on July 5, 1962 Submitted on July 30, 1962
Temperature-humidity effects on thyroxin I131 disappearance rates in cattle
Authors: Johnson H. D. , Kibler H. H. 
Published: December 2017

A significant depression of the thyroxin I131 disappearance rate was observed in lactating Holstein cows at 80 F, 80% relative humidity (RH); 85 F, 50% RH; 85 F, 70% RH; 90 F, 40% RH; 90 F, 50% RH; and 95 F, 20% RH. Differences from values at 65 F were not significant at 80 F, 30% RH; 80 F, 50% RH; 90 F, 20% RH; and 90 F, 25% RH. At 85 F and 90 F temperatures the effect of high humidity in depressing thyroxin I131 disappearance rate was obvious. Depression of hormone and feed intake at the higher humid temperatures suggests that the depression of thyroid gland function may be related to alteration in hormonal utilization in the peripheral tissues or to a more direct temperature effect (probably neural) on both thyroid gland secretion and appetite center. Thyroxin I131 disappearance rates, feed intake and body temperatures are expressed graphically relative to a temperature humidity index (THI) (U. S. Weather Bureau). The data show some decline above a THI of 71 and a marked decline above 75. Submitted on January 26, 1962
Rheology of blood and flow in the microcirculation
Authors: Merrill E. W. , Gilliland E. R. , Cokelet G. , Shin H. , Britten A. , Wells R. E. 
Published: December 2017

Rheological properties of normal human blood as a homogeneous substance: its yield stress and the stress-shear rate function under creeping shear rates, were directly measured for the first time in a Couette type viscometer, the cylinders of which were grooved to minimize heterophase effects (defined herein). The experimental data are well fitted by the Casson equation, which implies reversible aggregation of red cells into rouleaux at low shear rates. In particular, the value of yield stress extrapolated from the Casson equation is found to be equal to the directly measured yield stress within ± 10%. The yield stress is almost independent of temperature over the range 10–37 C. The following questions related to flow in the microcirculation are considered: the relation of yield stress to pressure drop and to the critical closing pressure, the significance of the Casson model to slow flow, and use of rheological parameters in general for microcirculatory flow calculations. Note: (With the collaboration of C. S. Draper, P. J. Gilinson, Jr., C. R. Dauwalter, M. Grove-Rasmussen, and R. Shaw) Submitted on July 10, 1962
Cardiorespiratory effects of large pneumothorax in conscious and anesthetized dogs
Authors: Kilburn Kaye H. 
Published: December 2017

Ventilation, arterial blood gases, diffusing capacity for carbon monoxide, and flow and pressure in the pulmonary circulation were measured in conscious and pentobarbital-anesthetized dogs at intervals up to 5 hr after intrapleural injection of air. Pneumothorax of twice the functional residual capacity increased the frequency of breathing and reduced physiological dead space in both conscious and anesthetized dogs, but conscious dogs were otherwise unaffected. In contrast, the arterial blood oxygen saturation fell, pulmonary artery pressure rose, and carbon monoxide diffusing capacity was reduced in anesthetized dogs despite greatly increased respiratory minute volume and alveolar ventilation. Ventilation was depressed by anesthesia alone in controls and improved gradually during the experiments. Pentobarbital anesthesia appeared to augment cardiorespiratory depression or abolish compensatory reactions evoked by pneumothorax to produce effects in anesthetized dogs which did not occur in their conscious counterparts. The potent effects of pentobarbital anesthesia on ventilation, pulmonary circulation, and carbon monoxide diffusing capacity, emphasize the advantage of conscious subjects in cardiorespiratory studies. Submitted on July 25, 1962
A-a difference in O2 tension and physiological dead space in normal man
Authors: Raine June M. , Bishop J. M. 
Published: December 2017

Alveolar-arterial difference in oxygen tension (A-aD) and physiological dead space/tidal volume ratio (Vd/Vt) were measured in normal subjects aged 17–66 years, in the supine and sitting postures. Paoo2 decreased and A-aD increased with age. A-aD was not affected by posture, but increased with Paoo2. Regression equations relating Paoo2 and A-aD to age, and Paoo2 were calculated. Vd/Vt increased with age in the supine position, but when sitting the increase with age was small and barely significant. Consequently, although Vd/Vt was greater when sitting than when supine in young subjects, there was no such difference in the older subjects. Possible reasons for the effect of age and body position are discussed. Submitted on August 6, 1962
Gas transfer across the skin in man
Authors: Klocke R. A. , Gurtner G. H. , Farhi L. E. 
Published: December 2017

Any inert component of the inspired gas reaches the skin by the cutaneous perfusion. When part of the body is enclosed in an oxygen-filled chamber, a portion of the inert gas is transported out of the tissues into the oxygen atmosphere. The rates of helium, argon, and nitrogen transport were determined in the forearm and hand of a normal subject at ambient temperatures ranging from 18 to 43 C, analysis being performed by gas chromatography. At any temperature, the ratio Va/Vhe was found to be equal to (αa·Pa/(See PDF)a)/ (αHe·Phe/(See PDF) He) where V is the rate of gas transport, agr the solubility of the gas in blood, P the pressure of the gas in the blood, and mol wt the molecular weight of the gas. This indicates that the gas transport is limited by diffusion through the skin barrier and is affected only indirectly by changes in cutaneous blood flow in individual capillaries. Gas transport is at a minimal value at temperatures below 28 C, increasing in a linear fashion with increasing temperature above 28 C. This increase in transport shows that the increase in cutaneous perfusion at elevated ambient temperatures is accompanied by the opening of additional capillaries, the resulting increase in diffusing capacity being responsible for the increase in gas transport. Submitted on August 6, 1962
Effect of physical exercise on blood clotting and fibrinolysis
Authors: Iatridis Sotirios G. , Ferguson John H. 
Published: December 2017

The effect of strenuous exercise on the clotting and fibrinolytic systems was studied on 1 Hageman-deficient and 59 normal subjects (males aged 18–37 years). In the normal subjects there was a significant shortening of the whole-blood clotting time and of the partial thromboplastin time both in glass and in siliconized tubes. Plasma factor VIII (AHF or AHG) assays rose to 188% (average), but the specificity of the test is questioned. Factor XII (HF) increased to 318% (average) unequivocally. A postexercise increased heparin tolerance was also noted. There was no significant increase in the levels of fibrinogen, prothrombin, factor V (AcG), or factor VII (proconvertin) and factor X (Stuart). Fibrinolytic activity as measured by the euglobulin lysis and plasma plate methods increased significantly in most of the normal subjects. The data suggest that the fibrinolytic factor which increases after exercise is not active plasmin, but is related to the “activator” mechanisms. A plasma lysokinase (indirect activator) seems to preponderate in over half the cases. In 20% of cases a plasminoplastin (direct activator) may be involved. In the Hageman-deficient subject there was no improvement in clotting, and the slight changes in some of the fibrinolysis tests were nonsignificant. Submitted on October 16, 1962 Submitted on October 16, 1962