bluuebunny/crossref_metadata_2025_split huggingface dataset:
ŅFree roamingņ in the albino rat and its effect on restraint hypothermia
Authors: Bartlett R. G. , Young M. W. 
Published: December 2017

‘Adaptation’ to a large environment increased the resistance of young adult female (175–225 gm) Sprague-Dawley rats to restraint hypothermia. Two changes may have occurred in the ‘free roaming’ rats which rendered them less susceptible to restraint hypothermia: 1) emotional adaptation to the changing stimuli of the ‘free roaming’ state may have lessened the emotional stress produced by restraint which would have reduced the hypothermic response ( Am. J. Physiol. 79: 343, 1954), 2) a possible cross-resistance produced by adaptation to the nonspecific stresses involved in the ‘free roaming’ state which would have inhibited restraint induced hypothermia ( J. Appl. Physiol. 8: 661, 1956). Submitted on September 8, 1958
Measurement of rates of excretion of sweat solutes under physiological conditions
Authors: Barrueto Richard B. , Mager Milton , Bass David E. 
Published: December 2017

An apparatus is described which permits the study of rates of excretion of sweat solutes under physiological conditions from an arm, and which permits regulation of skin temperature of the arm independent of ambient conditions. The apparatus permits the collection from the arm of all sweat solutes separately from the associated water. This is accomplished by isolating an arm in a thermoregulated copper cylinder. Air is circulated through the cylinder and the sweat water is collected in a trap system; the solutes are subsequently washed from the arm and the washings are analyzed. It was shown that the rates of excretion of sodium, potassium, chloride, ‘apparent’ creatinine and urea were the same from an arm enclosed in the apparatus as from the unenclosed arm. Thus, the apparatus can be valid44ly used in studying the effects of various environments on sweat gland activity for the five substances measured. Submitted on July 31, 1958
Maximal heart rate during work in older men
Authors: Åstrand Irma , Åstrand Per-Olof , Rodahl Kaare 
Published: December 2017

Nine 56–68-year-old male subjects performed muscular work up to maximal loads on a bicycle ergometer while breathing both ambient air and oxygen. Heart rate increased to an average maximum of 163/min. The maximal O2 intake averaged 2.24 l/min. and the blood lactic acid concentration 85 mg/100 ml. In no case was the maximal heart rate higher when breathing O2 than when breathing air. This low maximal heart rate in older people probably limits the capacity for O2 intake. Four subjects were able to work for about 1 hour without any sign of exhaustion on a work load requiring an O2 consumption of about 50% of their maximal aerobic work capacity. Submitted on October 3, 1958
Viscous metamorphosis, clot retraction and other morphologic alterations of blood platelets
Authors: Zucker Marjorie B. , Borrelli Jennie 
Published: December 2017

Some samples of washed platelets undergo viscous metamorphosis (VM) in oxalated or citrated plasma, oxalated serum or serum poor in prothrombin. Other samples only undergo VM when serum containing residual prothrombin is used and thrombin is evolved when platelets are added. Thrombin produces VM at pH 7.4 but not at pH 6.1 or in isotonic saline. Treatment of thrombin with diisopropylfluorophosphate (DFP) or addition of heparin plus serum inhibits VM. Spreading of platelets upon glass, and balloon formation are not closely correlated with VM. Clot retraction in a purified system often occurs without added buffer or glucose, but is always very marked in the presence of both buffer and glucose. Calcium binding anticoagulants prevent VM and clot retraction. The inhibition is reversed by calcium and, to a lesser extent, magnesium. Cyanide (4 or 5 x 10-3 m) does not inhibit VM or retraction in a purified system but inhibits retraction of platelet-rich plasma, especially when it is clotted with thrombin. At this concentration, fluoride has a variable effect. Mercuric chloride is an effective inhibitor of both VM and retraction at concentrations of 10-4 m and below. Submitted on November 20, 1958
Survival of rats and mice without oxygen in deep hypothermia
Authors: Adolph E. F. , Goldstein J. 
Published: December 2017

Adult rats and mice that were cooled quickly below 11℃ core temperature usually ceased to breathe. Suspension of breathing and heartbeats was tolerated at 2℃ for 1 hour, whether artificial breathing was given or not and whether air or nitrogen filled the lungs. At heart temperatures of 10℃, where heart beat was maintained, rats survived artificial ventilation with nitrogen for 0.4 hour; ventilation with air for 2 hours. Anaerobic survival at 10℃ was not demonstrably shortened by inhibitors of glycolysis (fluoride, iodoacetate). Reanimation of 90% of rats and mice under optimal conditions was accomplished by artificial warming, accompanied by artificial ventilation with air under intermittent positive pressure. Each process that becomes suspended at its biological zero apparently has a limited time within which rewarming may restore it. The limitation of times less than 1.5 hours was imposed mostly by anoxia. Properties of animals that were injured by anoxia or by hypothermia seemed to vary, since animals might die even after breathing was restored. Submitted on January 12, 1959
Energy metabolism in laboratory workers
Authors: Banerjee Sachchidananda , Sen Rabindra Nath , Acharya Keshav Narayan 
Published: December 2017

Energy expenditure during different activities of 11 laboratory workers was determined by measurement of oxygen consumption. The energy cost of various activities expressed as Calories per m2 body surface per hour were as follows: BMR 30.87 ± 0.741; lying rest 34.79 ± 0.578; sitting rest 36.61 ± 2.927; standing rest 41.24 ± 1.323; sitting study 42.85 ± 1.034; sitting work 46.79 ± 3.036; standing laboratory work 59.96 ± 3.937; standing household work 61.78 ± 3.675; walking 122.06 ± 6.25; ascending stairs 159.94 ± 5.610 and descending stairs 95.80 ± 6.3. The total daily energy expenditure of the subjects, determined for a period of 7 days, varied between 1620 and 2967 Cal. The average food actually consumed by the subjects was analyzed for fat, protein and carbohydrate to determine the calorific value. The intake varied between 1680 and 2928 Cal/day. Most of the subjects were in apparent positive caloric balance but caloric intake was probably overestimated becauseno correction was made for the caloric value of the excreta. Submitted on October 21, 1958
Food distribution during mastication
Authors: Askew Harold C. 
Published: December 2017

Roentgenologic observation of food distribution during mastication was made for 61 subjects wearing full artificial dentures. Thirty-one subjects (51%) displayed a predominantly unilateral food distribution, 22 subjects (37%) a simulataneous bilateral distribution, 5 subjects (8%) showed an equal utilization of the above two distribution methods, and 2 subjects (3%) showed the food distribution either between the upper and lower anterior teeth or in the center of the mouth. Essentially the same results were obtained with 12 subjects examined both by static x-ray pictures and fluoroscopy. Submitted on February 2, 1959
Effect of mechanical factors on respiratory work and ventilatory responses to CO2
Authors: Eldridge Frederic , Davis John M. 
Published: December 2017

The end-tidal pCo2, mechanical work of breathing, and ventilation were determined in normal subjects breathing air, 2.2, 4.2 and 5.8 per cent Co2, with no added resistance and with three grades of added airway resistance. With increasing resistance, pCo2 and work rose in parallel whereas ventilation remained constant or even decreased. In the presence of a constant Co2 stimulus, increasing airway resistance caused a progressive decrease in ventilatory response to Co2. The maximum breathing capacity was not in itself the limiting factor in the ventilatory response to Co2. It is concluded that mechanical abnormalities of the respiratory apparatus are an important factor in reducing the ventilatory response to Co2, and that work of breathing is a more satisfactory index of respiratory stimulation than ventilation. Since patients with obstructive emphysema have nonelastic resistance values in the same range as those used in this study, it is concluded that the low ventilatory response to Co2 in these patients can, in large part, be explained by the mechanical abnormalities. Submitted on April 28, 1959
Energy metabolism and gas exchange during treadmill running in dogs
Authors: Young D. R. , Mosher R. , Erve P. , Spector H. 
Published: December 2017

The energy cost of treadmill running was studied in six dogs at grades of 0, 4, 8, 12, 16, 19 and 22 degrees of inclination. The relationship between caloric expenditure and grade is significant. A product-moment coefficient of correlation of +0.978 was found. A product-moment coefficient correlation of +0.941 was found between work pulse rate and caloric expenditure. Climbing efficiency showed a maximum of 28% and decreased at the lowest and highest grades. Respiratory efficiencies were highest during resting conditions. Maximum O2 uptake increased with age to a peak value of 136 cc/kg/min. at 1 year of age. Maximum 24-minute recovery O2 debts of 4–6 liters were measured following exhaustive running. The data form a basic standardization background for application of the treadmill as a device for studies of controlled work output in the dog. Submitted on September 17, 1958
Effect of tolbutamide on glucose uptake by leucocytes of patients with diabetes mellitus
Authors: Dumm Mary E. 
Published: December 2017

Glucose uptake and lactate production have been measured in suspensions of leucocytes in plasma. The rate of glucose uptake of the leucocytes of diabetics who required less than 30 u of insulin per day did not differ significantly from that of normal subjects and was higher than that of severe diabetics. Two hours after 1 gm of tolbutamide was given intravenously to the diabetic subjects, glucose uptake and lactate production tended to increase in subjects whose blood sugar fell at least 12%. Glucose uptake and lactate production by the leucocytes increased in some, but not in all normal subjects after the oral administration of glucose. Observations on the effects of tolbutamide are compatible with the hypothesis that one effect of the drug is to enhance the secretion of insulin by the pancreas. Submitted on May 28, 1959
Metabolic studies on perinatal human brain
Authors: Himwich Williamina A. , Benaron Harry B. W. , Tucker Beatrice E. , Babuna Cevat , Stripe Margaret C. 
Published: December 2017

Oxygen consumption and carbon dioxide production were determined on minced samples of cerebral cortex, caudate nucleus, thalamus and medulla oblongata of the brains of 22 human infants ranging in age from 160 to 283 days of gestation. A significant correlation of age and oxygen consumption was obtained for cerebral cortex, caudate nucleus and thalamus. The oxygen consumption of these parts was greater than that of the medulla oblongata after 200 days of gestation age. The results emphasize the impossibility of comparing the brain of the neonatal human being with the young of other species until more comparative developmental data are available. Submitted on April 30, 1959
Uptake of cyclopropane by the human body
Authors: Sechzer P. H. , Dripps R. D. , Price H. L. 
Published: December 2017

The uptake of cyclopropane was measured in 5 human subjects who breathed a 1% concentration of the gas in oxygen for periods ranging from 7 to 62 minutes. The measured concentrations of cyclopropane in end-expired air were compared with those predicted by Kety's equation ( Pharmacol. Rev. 3:1, 1951) describing the saturation process for inert gases. Although fair agreement was found between the measured and predicted data, it was noted that the measured values increased more rapidly than theory predicted. This difference apparently resulted from Kety's simplifying assumption that the body consists of a homogeneous tissue mass. Submitted on May 25, 1959
Tolerance and cross-tolerance development to atmospheric pollutants ketene and ozone
Authors: Mendenhall R. M. , Stokinger H. E. 
Published: December 2017

Tolerance to oxidants, that is remarkable both in its rapidity of onset and its high degree of protectiveness, has been demonstrated in mice exposed briefly to ketene. Exposure of mice to concentrations of ketene in excess of 5 ppm for 10 minutes protected mice 3–14 days later against otherwise lethal exposures. Similarly, a cross-tolerance was demonstrated for ozone; a pre-exposure to ketene protected mice against lethal concentrations of ozone. Ozone likewise produced a cross-tolerance for lethal exposures to ketene. The 10-day LC50, which is the concentration required to produce a 50% kill in 10 days by a 10-minute exposure of mice to ketene, approximates 17 ppm (v/v), with production of pulmonary edema. Pulmonary edema of lesser degrees resulted at lower exposure concentrations, but was not present to a significant extent in mice exposed to lethal concentrations of the respiratory oxidants, provided the mice had first received a tolerance-producing pre-exposure of the respiratory oxidant. Submitted on June 8, 1959
A modified Harvard step test for women
Authors: Sloan A. W. 
Published: December 2017

The fitness indexes of two groups of healthy young women performing the Harvard step test on steps of various heights were compared with the fitness indexes of a corresponding group of men performing the test on a step of the standard height (20 inches). The closest agreement with the results of the men was attained by women using a step 17 inches high. Not only did the mean fitness indexes correspond, but also the distribution of individuals in the several categories of physical fitness. Submitted on June 15, 1959
Adrenolytic and sympatholytic action of certain dihydrogenated ergot alkaloids (Hydergine) on dog kidney
Authors: Kubicek W. G. 
Published: December 2017

Adrenolytic action of dihydrogenated (DH) ergot alkaloids was estimated in denervated dog kidneys and the sympatholytic action was estimated on electrically stimulated renal nerves. Blood sugar level, hematocrit, blood pressure and pulse rate were observed in most of the experiments. The minimal effective intravenous dose of Hydergine or its components to block the epinephrine vasoconstriction in the denervated kidneys was approximately 3.5 μg/kg of body weight while a somewhat larger dose was required to block sympathetic nerve impulse transmission. Oral administration of these alkaloids required a dosage approximately ten times the minimal effective intravenous dose. The DH ergot alkaloids reduced the epinephrine-induced hypertension and had little if any effect upon the hyperglycemia and elevated hematocrit observed during continuous epinephrine infusions. Submitted on May 29, 1959
Lung volumes of singers
Authors: Heller Stanley S. , Hicks William R. , Root Walter S. 
Published: December 2017

Lung volume determinations (tidal volume, inspiratory capacity, inspiratory reserve volume, expiratory reserve volume, vital capacity, maximum breathing capacity, functional residual capacity, residual volume, and total lung capacity) were carried out on 16 professional singers and 21 subjects who had had no professional vocal training. No differences were found between the two groups of subjects, whether recumbent or standing, which could not be explained upon the basis of age, size, or errors involved in making the measurements. Submitted on March 24, 1959
Effect of breathing O2 at one atmosphere on O2 consumption of rats
Authors: Froese Gerd 
Published: December 2017

The O2 consumptions of different groups of rats, young, old, warm acclimatized and cold acclimatized, were compared in atmospheres of O2 vs. air at different temperatures. Significant effects of O2 were found in some cases, not in others, and even the direction of change was different. In spite of the diversity of the results, plotting the O2 consumption breathing air minus that breathing air vs. the level of O2 consumption gave significant negative correlations. The O2 effect therefore exists, but depends on the level of metabolism. The effect was shown to be transient, lasting up to 3O minutes. It could not be attributed to changes in the amount of gases dissolved in body fluids of the rats. It probably represents a transient effect on a steady-state metabolic system and might be thought of as a first sign of ‘ O2 poisoning.‘ Submitted on January 20, 1959
Reflections in model and arterial pulse waves
Authors: Evans Robert L. , Hosie Kenneth F. , Kooiker Robert H. , Perry John , Stish Richard J. 
Published: December 2017

Intermittent half-sine wave flows were used to introduce pressure pulses into a distensible tube model. These pressure pulses were measured and were analyzed quantitatively for their forward-propagated and retrograde components, assuming that the components have the same propagation velocity in their respective directions. An arterial pulse showing relatively much reflection was analyzed similarly for comparison and was found to have a reflected component no greater than three-tenths as much as the propagated component, which is considerably less than the reflections occurring in the model. Submitted on February 27, 1959
Changes in foot volume and capillary fragility during continuous cold exposure and starvation
Authors: Norman Paul S. , Kreider Marlin B. , Iampietro P. F. 
Published: December 2017

The effects of continuous cold exposure (2 wk. at 60°F) and starvation on foot volume and capillary fragility were studied in six men. The experimental period was preceded and followed by 2-week periods (control and recovery) at 80°F and a caloric intake of 2400 cal. Foot volumes decreased 6.1% in the first 5 hours of cold exposure and remained constant for the remainder of the experimental period. Foot volume was also measured after 3 minutes of elevation of the foot and occlusion of the blood supply. This volume decreased less during the experimental than the preceding or following periods. Capillary fragility decreased slowly during the experimental period and increased in the recovery period. On the third day of recovery, foot volumes were larger than at any other time. For the remainder of recovery, foot volume was the same as the control volume, but there was a greater decrease in volume with foot elevation. The results suggest that there was a constriction of all types of blood vessels during the experimental period while in the recovery period there was apparently a simultaneous dilatation of large blood vessels and a constriction of small ones. One subject had a greatly increased volume of one foot associated with pain and redness during early recovery days. These changes may be indicative of early trench foot or capillary damage. Starvation per se appeared to have no effect on foot volume. Submitted on October 15, 1959
Effect of negative intra-alveolar pressure on pulmonary diffusing capacity
Authors: Cotes J. E. , Snidal D. P. , Shepard R. H. 
Published: December 2017

In one of two subjects studied in detail, using 0.1% carbon monoxide in the test gas and a 10-second breath-holding period, the alveolar capillary blood volume (Vc) was found to increase by nearly 100% when the intra-alveolar pressure was made negative during breath holding. This was accompanied by a reduction in venous pressure in the forearm. In both subjects Vc was increased on exercise. The diffusing capacity of the alveolar capillary membrane (Dm) remained relatively constant in spite of large changes in Vc. The findings suggest that stationary blood is present in some alveolar capillaries at rest. The implications of this finding and a likely mechanism for the increase in Vc with negative pressure are discussed. xsSubmitted on September 14, 1959
Effect of hypothermia on ventilatory response to carbon dioxide inhalation and carbon dioxide infusion in dogs
Authors: Salzano John , Hall F. G. 
Published: December 2017

Some respiratory and circulatory responses to carbon dioxide stress during ice-water immersion hypothermia were studied in 13 dogs. Stresses were imposed by increasing the carbon dioxide tension of the inspired gas in eight animals and by intravenous infusion of gaseous carbon dioxide in five other animals. It was found that when compensation is made for the depressed ventilation exhibited at low body temperature, animals responded to the carbon dioxide stresses in essentially the same manner in the hypothermic as in the normothermia state. However, the responses are of a lower order of magnitude. Submitted on November 19, 1959
Effects of local cooling or heating in deeply hypothermic rats
Authors: Orchard D. P. , Adolph E. F. 
Published: December 2017

Rats were cooled to 17°C core temperature, and then either the head or the chest was further cooled by 5° – 10°. Thermocouples in the hypothalamus and in the vena cava recorded the differences of temperature; electrocardiograms and breathing were observed. Breathing could cease reversibly when the head was cooled and also after a period of gasping whenever the heart was much cooler than the head. Artificial ventilation of the lungs with air did not modify the result of restricted blood flow. Whenever the brain was cooler than the heart, however, artificial ventilation with air could replace spontaneous breathing; the blood flow was then usually adequate. Artificial ventilation with nitrogen reduced the time within which recovery was possible. In general the warmest tissue (head or chest) determined the time of endurance without adequate delivery of oxygen from lungs and blood. Any local cooling failed to increase the rat's endurance of oxygen lack. The results are interpreted to mean that failures to survive below 14°C for 1 hour are due to inadequate oxygen delivery. However, even oxygen delivery believed to be adequate did not allow indefinite survival; 2 hours remained the mean tolerance time below 14°C. Submitted on November 23, 1959
Physiological studies during hypothermia in monkeys
Authors: Bryce-Smith R. , Epstein H. G. , Glees P. 
Published: December 2017

Rhesus monkeys were subjected to hypothermia (20°C) after initial, light anesthesia. Heart rate, EEG and minute volumes during spontaneous respiration were recorded. With cooling there was a progressive fall in heart rate, respiratory rate and minute volume unrelated to the type of anesthetic agent (quantitatively administered ether or i.v. pentobarbitone). Spontaneous EEG waves disappeared at 23°C following initial anesthesia with pentobarbitone, but persisted to 19°C after ether anesthesia. Bemegride injected into the hypothermic monkeys caused activation of the EEG. It is concluded that similar procedures could be applied with safety to human subjects for psychiatric purposes. Submitted on August 28, 1959
Lung volumes, lung compliance and airway resistance during negative-pressure breathing
Authors: Ting E. Y. , Hong S. K. , Rahn H. 
Published: December 2017

Lung volumes, airflow resistance and lung elastance were measured in seven subjects during various degrees of continuous negative-pressure breathing in the supine posture. At –30 cm H2O the expiratory reserve is reduced to about 30% of its normal value and the resistance to airflow is more than doubled. On the other hand, the pressure-volume curve of the lung measured with the aid of an esophageal balloon was not significantly altered by either negative-pressure or positive-pressure breathing. Submitted on February 8, 1960