bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heat exchange in men and women following intravenous injection of endotoxin
Authors: Buskirk E. R. , Thompson R. H. , Rubenstein M. , Wolff S. M. 
Published: December 2017

An assessment was made of heat exchange during the course of an induced febrile episode following injection of endotoxin. Experiments were performed on either normal subjects or patients with recurrent fever. They were given intravenously either saline or a dose of 1 or 2 mμg Lipexal (the lipopolysaccharide of Salmonella abortus equi) per kilogram approximately 15 min before being exposed for 3–6 hr to 27.7 C air while wearing minimal clothing. Continuous measurements were made of: oxygen consumption, carbon dioxide production, core temperatures, skin temperatures, muscle surface temperature, and heat flow from the lateral surface of the upper and lower arm and the back of the hand. Three distinct patterns of reactivity were found: a) nonreactors (N = 2), b) those in whom elevated heat production preceded a rise in core temperature (N = 8), and c) those in whom thermal redistribution produced a rise in core temperature prior to an increase in heat production (N = 5). The results suggest that endotoxin may produce fever by alteration of either vasomotor control of heat redistribution or heat production at independent rates. Fever patients, in comparison to normal subjects, appeared to have an exaggerated metabolic response per equal increment in core temperatur Note (With the Technical Assistance of D. Thrasher) cold; fever; temperature regulation Submitted on December 23, 1963
Effect of some drugs on reflex vasodilatation of hand produced by radiant heating of trunk
Authors: Appenzeller Otto , Schnieden Harold 
Published: December 2017

The effect of some drugs on reflex vasodilatation in the hand was studied. Bretylium tosylate and phenoxybenzamine abolished the reflex vasodilator response in the hand caused by cradle heating of the chest. Alpha methyl dopa, nethalide, and atropine had no effect on this response. It is suggested that the tonic constriction of hand vessels maintained by sympathetic fibers and alpha adrenergic constrictor receptors is temporarily interrupted by 40 sec cradle heating of the chest and that this produces the observed increase in hand blood flow. The reflex increase in hand blood flow with short cradle heating of the chest appears to utilize a common efferent pathway with the vasodilator response produced in the hand by prolonged heating of the legs. On the afferent side, however, these reflexes use different mechanisms. afferent and efferent pathways; alpha methyl dopa; nethalide; atropine; receptors on hand vessels; bretylium tosylate; phenoxybenzamine Submitted on February 24, 1964
Lactate and pyruvate gradients between red blood cells and plasma during acute asphyxia
Authors: Daniel Salha S. , Morishima Hisayo O. , James L. Stanley , Adamsons Karlis 
Published: December 2017

The rate of equilibration of lactate and pyruvate between plasma and red cells has been studied during asphyxia and following addition of sodium lactate in vivo and in vitro. In the resting, well-oxygenated guinea pig, the mean plasma/red cell ratio of lactate was 1.55 and that of pyruvate 2.47. During asphyxia, the plasma/red cell ratio of lactate rose and that of pyruvate fell, indicating a delay in equilibration. Incomplete equilibration affected particularly the lactate/pyruvate ratio in the two compartments. Infused neutral sodium lactate penetrated the red cells at a rate comparable to that observed following endogenous release of lactic acid during acute asphyxia. In vitro at pH 6.8@#X2013;7.4 at 38 C, the time to 50% equilibration of lactate between plasma and cells of human blood was less than 2 min. It is concluded that during acute asphyxia and resuscitation whole blood values of lactate and pyruvate do not bear a constant relationship to those of plasma. lactate/pyruvate ratio Submitted on March 16, 1964
Inert gas-exchange theory using an electric analogue
Authors: Mapleson W. W. 
Published: December 2017

When an inert gas of moderate or high solubility in blood is inhaled, the rate at which the alveolar concentration rises toward the inspired concentration increases as the inspired concentration is increased. The only previous systematic analysis of whole-body uptake of inert gases to allow for this effect was restricted to a single, artificial, respiratory pattern and the numerical calculations had to be made on a digital computer. This paper develops the theory for a range of respiratory patterns and shows how the computations may be made on a slightly modified form of a simple electric analogue. It is shown that the rate of saturation of the body increases less markedly with inspired concentration if the inspired alveolar ventilation, rather than the expired alveolar ventilation, is kept constant during the saturation process. Conversely, washout is more rapid with a constant inspired ventilation than with a constant expired ventilation. The theory is extended to show how the uptake of one inert gas may substantially affect the uptake of another, administered simultaneously. uptake, distribution and elimination; induction; recovery; drugs; inhaled anesthetics; nitrous oxide; diethyl ether; halothane; computers; ventilation; concentration effect; alveolar ventilation Submitted on February 13, 1964
Pulmonary diffusing capacity and capillary blood volume in normal and anemic dogs
Authors: Jouasset-Strieder Denise , Cahill John M. , Byrne John J. , Gaensler Edward A. 
Published: December 2017

The CO diffusing capacity (Dl) was measured by the single-breath method in eight anesthetized dogs. Pulmonary capillary blood volume (Vc) and membrane diffusing capacity (Dm) were determined in six animals by the method of Roughton and Forster. The studies were repeated after anemia had been induced by replacing whole blood with plasma. Large dogs were selected with a mean body weight of 29 kg and a mean alveolar volume of 2,020 ml (STPD) during tests. The mean arterial blood Hb decreased from 14.3 to 6.6 g/100 ml, the mean Dl from 27 to 12 ml/min mm Hg, and the mean Dm from 100 to 47 ml/min mm Hg. Vc averaged 67 ml in the control state and was not significantly changed during anemia. Reductions in Dl and Dm during anemia were proportional to the fall in blood Hb. Both Dl and Dm in all dogs, normal and anemic, were proportional to the volume of red blood cells in the lung capillaries (Vrbc). These results suggest that Vrbc might be an estimate of the useful area of the alveolar-capillary membrane while Dm/Vrbc should vary with changes in its thickness. The latter was not altered by anemia. alveolar capillary membrane; pulmonary membrane; diffusing capacity; pulmonary capillary RBC volume; pulmonary diffusion pathway; carbon monoxide Submitted on March 2, 1964
Mechanism of bronchoconstriction during inhalation of sulfur dioxide
Authors: Nadel J. A. , Salem H. , Tamplin B. , Tokiwa Y. 
Published: December 2017

Inhalation of SO2 (4–6 ppm) for 10 min decreased airway conductance (increased airway resistance) in seven healthy subjects. Subcutaneous injection of atropine prevented this effect. In anesthetized, paralyzed, artifically ventilated cats, SO2 increased pulmonary resistance, whether delivered to the upper or to the lower airways. This was prevented by complete cold block of the cervical vagosympathetic nerves or by injecting atropine intravenously before the SO2 was inhaled. These results establish the reflex nature of bronchoconstriction during inhalation of SO2. Note: With the Technical Assistance of Earl H. White reflex bronchoconstriction; airway resistance Submitted on February 18, 1964
Constant-depth halothane anesthesia in respiratory studies
Authors: Brandstater Bernard , Eger Edmond I. , Edelist Gerald 
Published: December 2017

Respiratory depression from anesthetic drugs introduces an undefined variable into many experiments. We have produced constant-depth anesthesia in dogs by maintaining an unvarying alveolar concentration of halothane, and we have tested whether such anesthesia can produce a steady state with respect to the respiratory response to CO2. At a constant alveolar halothane concentration, the response to CO2 remained essentially unchanged for up to 8 hr. Carbon dioxide response curves were also obtained at several different alveolar concentrations of halothane. Carbon dioxide response was sensitive to small changes in halothane concentration; the slope of the response curve diminished linearly with increase in alveolar concentration of halothane. With alveolar halothane concentration held constant, a small dose of intravenous thiopental produced a depression of the CO2 response curve that remained for more than 2 hr. carbon dioxide response; control of respiration; depression; respiratory response Submitted on April 29, 1964
Postural effect on ventilatory control
Authors: Anthonisen N. R. , Bartlett D. , Tenney S. M. 
Published: December 2017

Minute ventilation, alveolar CO2 tension (Paco2), and arterial CO2 tension (Pacoco2) were studied in human subjects during passive tilt from the supine to the erect position. These measurements showed that the erect position was associated with relative alveolar hyperventilation. The hyperventilation of the erect position was found to be almost entirely reversible if hydrostatic effects were removed by water immersion to the level of the xiphoid. Postural changes in ventilation correlated with circulatory changes, suggesting a causal relationship. However, the possibility of a gravity-sensitive abdominal receptor which influences ventilation was not eliminated. ventilation; alveolar ventilation; posture; alveolar gas tension Submitted on April 27, 1964
Effect of oxygen upon pulmonary circulation in acclimatized man at high altitude
Authors: Hultgren H. N. , Kelly J. , Miller H. 
Published: December 2017

The response to breathing 100% oxygen was studied in 26 acclimatized residents of the Peruvian Andes at altitudes of 12,300 and 14,200 ft. Arterial oxygen saturation increased from 86% to 96%. Mean pulmonary artery pressure decreased by 5 mm Hg and cardiac output did not change. Calculated pulmonary arteriolar resistance was lowered. Pulmonary artery pressure during oxygen breathing was not decreased to normal values observed at sea level. The data suggest the presence of two factors responsible for the increase in pulmonary arteriolar resistance at high altitude: 1) hypoxic vasoconstriction which is reversed by oxygen breathing and 2) anatomic alterations which are not affected by oxygen breathing. Oxygen breathing at high altitude also produced a slowing of the heart rate and increased the relative height of the secondary or tidal wave of the brachial arterial pressure pulse. pulmonary arteriolar resistance and 100% oxygen; arterial pulse contour–effect of 100% oxygen at high altitude; pulmonary arteriolar resistance–nature of in high altitude; hypoxic vasoconstriction at high altitude–reversal by 100% oxygen breathing; oxygen breathing–comparison of effect on pulmonary circulation at high altitude and sea level Submitted on May 8, 1964
Controlled frequency breathing during muscular exercise
Authors: Lamb T. W. , Anthonisen N. R. , Tenney S. M. 
Published: December 2017

Three human subjects exercised at 2 and 4 mph on a treadmill while breathing room air and 100% oxygen. Respiratory frequency was voluntarily controlled at 6, 12, and 24 breaths/min so that the only ventilatory response possible was a change in tidal volume. Mean CO2 tension of arterialized venous blood was maintained constant near the resting value by each subject under all experimental conditions, including oxygen breathing with the exception of one subject who hyperventilated at 2 mph while breathing 24 times/min. Oscillations in alveolar and arterial Pco2 within each respiratory cycle were markedly altered by respiratory frequency and the intensity of exercise. No relationship was found between Ve, Va, Vt, and the amplitude of oscillation or the rate of change of arterial Pco2 or Po2. Varying levels of the work of breathing were observed while the arterial Pco2 remained constant. It is concluded that the oscillations in arterial Pco2 and Po2 which are observed at rest and during muscular exercise are associated phenomena, not controlling stimuli. oscillations; chemoreceptors; work of breathing; control of ventilation; frequency of breathing Submitted on June 17, 1964
Tolerance of hot, wet environments by resting men
Authors: Goldman Ralph F. , Green Edward B. , Iampietro P. F. 
Published: December 2017

Studies were conducted on 10-man groups exposed at rest to 51 different hot, wet environmental conditions."Tolerance times" of unacclimatized volunteers established objectively, as the time of occurrence of a rectal temperature of 102.5 F and/or a heart rate of 180 beat/min, were similar to reported values established on a subjective basis. The wet and dry bulb index (WD) of environment was the best predictor of tolerance time. Prior acclimatization to work in hot, dry conditions did not result in prolonged tolerance for resting men exposed to hot, wet environments; neither did it alter the rates of sweat production, the final skin temperatures, or the rates of increase in heart rate or rectal temperature during these resting, hot, wet environmental exposures. Finally, "passive" resting in hot, wet environments (up to 3 hr/day) did not prolong tolerance times or induce other manifestations of heat acclimatization during subsequent resting exposures to hot, wet environments for either unacclimatized or prior, hot, dry, acclimatized subjects. heat tolerance; acclimatization; sweat rates; heart rates; body temperatures; environmental indices Submitted on June 17, 1964
Cutaneous circulation during dehydration and heat stress
Authors: Senay Leo C. , Christensen Margaret L. 
Published: December 2017

Resting subjects were exposed for 12 hr to 43 C dry bulb, 28 C wet bulb, with and without rehydration. During dehydration, average weighted cutaneous opacity pulse amplitudes decreased 19.5%. An apparent relationship between calculated stroke volume and cutaneous pulse amplitudes existed. A 26% increase in heart rate offset decreases in perfusion per beat and probably contributed to a rise in diastolic pressure. Increases in skin temperature paralleled those of oral temperatures. In most subjects evaporative rates were slightly lower during dehydration. Certain dehydrating subjects maintained sweat rates at control levels but this did not prevent an increase in both oral and skin temperatures. Failure of temperature regulation in these experiments does not appear to be due to a decrease in heat transport or evaporation but rather to a lack of responsiveness of the sudomotor and vasomotor systems to increases in body temperature. Reasons for the temperature rise appear complex. evaporative weight loss; heat transport; skin temperature; temperature regulation Submitted on July 22, 1964
Speed of action of atropine on sweating
Authors: Craig F. N. , Cummings E. G. 
Published: December 2017

The influence of intravenously injected atropine sulfate on sweating was measured in three men by continuous recording of body weight. Most of the skin surface was kept dry by air movement at 1.5 m/sec. The sequence of events was: completion of injection in 1.1 min; cardiac acceleration in 1.3 min; and inhibition of sweating in 3.5 min. The minimum rate of weight loss occurred at a dose of 0.5 mg; larger doses prolonged the inhibition without intensifying it. Heat storage was equal to an average of 92% of the deficit in evaporative heat loss. Although sweating returned to the initial rate within an hour, the normal increase in sweating at elevated body temperatures was prevented for the next hour. Sweating responds to atropine almost as rapidly as the cardiac rate. The degree of inhibition is independent of the initial rate of sweating. heart rate; skin temperature; rectal temperature; heat exposure; heat loss by evaporation; man continuous recording of body weight; exercise Submitted on June 24, 1964
Oxyhemoglobin dissociation curve in liver disease
Authors: Caldwell P. R. B. , Fritts H. W. , Cournand A. 
Published: December 2017

The in vivo oxyhemoglobin dissociation curves of patients with liver disease appear to be displaced to the right of those of normal men. Although the displacement is small it may contribute to the arterial unsaturation which sometimes occurs. hemoglobin; oxygen electrode; unsaturation Submitted on March 9, 1964
A hyperbaric chamber for small animals
Authors: Van Tassel Peter V. 
Published: December 2017

A portable chamber, 30 liters in capacity, for the exposure of small animals to hyperbaric atmospheres is described. It can be used with pressures up to 7.5 atm, has walls of transparent plastic which allow almost unlimited visibility of the interior, and can be built at relatively low cost. Construction details and some recommendations for testing and use are given. high pressure oxygen Submitted on July 16, 1964
Effects of external elastic and threshold loading on breathing in man
Authors: Freedman S. , Weinstein Stephen A. 
Published: December 2017

Conscious human subjects, seated in a soundproof chamber, were made at intervals to inspire through external elastic or threshold loads for from 4 to 15 breaths With threshold loading of -5 to -15 cm H2O (13 subjects) initially, the first loaded breath was smaller than preceding breaths with tidal volume returning to normal within 6 breaths. With further presentations, tidal volume returned to control values sooner. After six presentations, 10 subjects had no diminution in tidal volume on the first loaded breath. With elastic loading, of 10 cm H2O/liter (five subjects) and 19.5 cm H2O/liter (four subjects) a different type of adaptation occurred. This was characterized by decreased tidal volume and increased frequency. With the larger load, after three presentations frequency was increased during loaded breathing, due to a conscious effort by the subjects. The results show that repeated presentation of an elastic or threshold load leads to a change in the response to the load in a manner analogous to the learning of voluntary motor acts. respiration; learning; tidal volume; respiratory frequency; regulation of respiration Submitted on July 9, 1964
Tracheal motion during eupnea
Authors: Scarpelli Emile M. , Real Franz J. P. , Rudolph Abraham M. 
Published: December 2017

A method is described for the direct measurement of upper airway circumference and length with mercury strain gauges fixed to the trachea and main bronchus. The gauges were permanently placed in dogs and were used in serial studies in the intact animal, anesthetized and unanesthetized. The method proved to be reliable and relatively unaffected by extraneous factors. Three types of tracheal motion were observed during eupnea: 1) Primarily passive changes in tracheal length and circumference during each respiratory cycle; the circumference changes could be related to changes in transmural pressure and the length changes related to the over-all downward movement of the lungs during inhalation. 2) The breath-by-breath tracheal motion was superimposed on rhythmic alterations of length and circumference mediated through the vagus nerves. 3) There was a tonic tracheoconstriction which was also dependent on vagal innervation. All changes in airway dimensions involved the entire trachea as a unit, with no evidence for tracheal peristalsis. Changes in airway volume were calculated from the length-circumference data. Note: (With the Technical Assistance of Bernard Minter) direct measurement of airway dimensions; mercury strain gauge; vagal innervation and tracheal dimensions; tracheal volume Submitted on July 13, 1964
Lung function and blood-gas exchange, before and after cardiac surgery
Authors: Weintraub H. D. , Sullivan S. F. , Malm J. R. , Bowman F. O. , Papper E. M. 
Published: December 2017

Lung volumes, bellows functions, and lung blood-gas distribution have been studied in 15 patients with severe acquired valvular heart disease. Nine of these patients were also studied after definitive surgical correction. Vital capacity which was decreased an average of 26% did not change postoperatively. Functional residual capacity, residual volume, and total lung capacity did not change significantly. Maximal voluntary ventilation and forced expiratory volume (1 sec) did not change significantly. No abnormality was detected in the intrapulmonary mixing of inspired gas either before or after operation. Mean arterial oxygen tension was 10–15 mm Hg lower than normal. The mean shunt fraction of total cardiac output was 3.1% and increased insignificantly to 4.1% postoperatively. The alveolar-arterial oxygen tension difference ((A – a)DO2) was high. However, no change was noted after operation. The nonshunt component of the (A – a)DO2 was higher than normal and did not change after operation. alveolar-arterial oxygen tension differences; lung function in acquired valvular heart disease; shunts; lung blood-gas distribution Submitted on June 29, 1964
Pulmonary vasoconstriction during histotoxic hypoxia
Authors: Lloyd Thomas C. 
Published: December 2017

Increases in pulmonary vascular resistance could be produced in excised perfused ventilated dog lung lobes by lowering the alveolar Po2. When dinitrophenol was added to the perfusate a similar change in the vascular bed occurred that could be reversed by ventilating with supernormal oxygen concentrations. The similarity of the responses to dinitrophenol and lowered alveolar Po2 was demonstrated using normally and retrogradely perfused lobes. The hypoxic pressor response was shown to be independent of the Po2 of blood contained in the arteries and veins. Note: (With the Technical Assistance of Emily McCartney) dinitrophenol; cyanide; vascular effect of intravascular oxygen concentration Submitted on August 13, 1964
Critical studies on determination of thyroid secretion rate in cold-adapted animals
Authors: Héroux O. , Brauer R. 
Published: December 2017

Estimation of thyroid secretion rate by determining the amount of l-thyroxine required to block the thyroidal I131 release, confirmed that the thyroxine requirement of 6 C-acclimated rats is twice as high as that of 23 C-acclimated controls (5.5 ± 0.7 μg/100 g per day against 2.73 ± 0.3 μg/100 g per day). In white rats acclimatized to cold by outdoor exposure during the winter on the other hand, it was only 1.8 ± 0.38 μg/100 g per day. Larger amounts of thyroxine were found in the feces of the 6 C-acclimated rats (1.66 ± 0.66 μg/100 g body wt per day) as compared to 0.69 ± 0.07 μg/100 g body wt per day for controls. Urinary elimination rates of I131 were more rapid in “6 C rats” than in controls. These observations indicate that the greater requirement for thyroxine in cold-adapted rats is at least partly due to greater fecal loss of the hormone. It seems plausible to seek an explanation for the lesser thyroxine requirement of the outdoor winter rats in their fecal elimination rate of that hormone. cold acclimation; fecal excretion of thyroxine Submitted on June 18, 1964
Alterations in pulmonary mechanics with airway obstruction during rest and exercise
Authors: Hanson John S. , Tabakin Burton S. , Levy Arthur M. , Falsetti Herman L. 
Published: December 2017

The effects of artificial expiratory airway obstruction on pulmonary compliance, work of breathing, and pressure-flow relationships have been studied in five normal young males at rest and during treadmill exercise. The finding of a significant decrease in compliance during resistance breathing strongly suggests that alterations in pulmonary blood volume have occurred. In addition, there is evidence that uniformity of gas distribution within the lung has been impaired, a finding which is consonant with previously studied changes in lung volumes secondary to the obstruction. expiratory airway obstruction; compliance; work of breathing; pulmonary mechanics during exercise; resistance breathing during exercise Submitted on October 8, 1964