bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of water temperature on oxygen uptake by swimming rats
Authors: Baker Mary Ann , Horvath Steven M. 
Published: December 2017

Oxygen uptake and rectal temperature of ten rats forced to swim to exhaustion or for 45 min in cold, hot, and thermoneutral water were measured during swimming. In 20 C water rats swam for 12.6 min and had a final rectal temperature of 26.9 C. In 42 C water the mean swimming time was 14.1 min and the final rectal temperature was 42.6 C. All rats swam for 45 min in water of 37 C, and the final rectal temperature was not different from the preswim temperature. Oxygen uptake during swimming in 37 C water rose and stabilized at a rate of about three times basal in a pattern suggesting that the swimming work was moderate. Animals swimming in cold and hot water were exhausted before their oxygen uptakes stabilized, but the increasing oxygen uptakes during the early parts of these swims were similar to that in neutral water. It appeared that while the metabolic rate was adjusted to the level of work and was not greatly affected by severe changes in body temperature, alterations in body temperature profoundly influenced the duration of work in the hot or cold environments. exercise and thermal stress; exercise metabolism Submitted on March 23, 1964
Oxygen used in horizontal and grade walking and running on the treadmill
Authors: Dill D. B. 
Published: December 2017

The net oxygen cost of level and grade running was determined in three men-the author and two champion runners. The horizontal costs for the three were in agreement at the lower rates and for the two runners at high rates. A curve enables one to estimate the cost of horizontal walking and running and also of the horizontal component of grade walking and running. With this as a basis the cost of the vertical component in grade walking was found to be 1.53 ml/m·kg for the author and 1.31 ml/m·kg for one of the runners in both walking and running. This latter value and the curve relating the cost of the horizontal component to the rate of walking and running were used to estimate the cost of grade walking and running for seven other champion runners. The estimates checked closely with the observed cost in five. Marathoner DeMar was more efficient and the seventh runner was less efficient than predicted. champion athletes; work performance; work efficiency; oxygen cost of climbing Submitted on April 13, 1964
Temperature coefficients for Pco2 and Po2 of blood in vitro
Authors: Nunn J. F. , Bergman N. A. , Bunatyan A. , Coleman A. J. 
Published: December 2017

Temperature coefficients of Pco2 and Po2 have been determined experimentally for fresh human blood. Changes in Pco2 over 18 C conformed closely to an exponential change with Pco2 (hot)/Pco2 (cold) equal to 10 to the power of 0.019 x temperature difference. For change of Po2 in fully saturated blood the corresponding value for the exponential constant was 0.0052. In contrast to water, the changes during warming were not significantly different from those during cooling. The exponential constant for oxygen rose with decreasing hemoglobin saturation to 0.032 at 83%. blood carbon dioxide tension; blood oxygen tension; polarography; temperature correction factors for blood Submitted on March 11, 1964
Immediate respiratory response to sudden cooling of the skin
Authors: Keatinge W. R. , Nadel J. A. 
Published: December 2017

Showers at 25 C and below increased ventilation in man and respiration often could not be controlled voluntarily during showers at near 0 C. The increase took place within seconds and was accompanied by an increase in arterial pO2. The response could be obtained from high decerebrate cats and is believed to be a reflex initiated by cold receptors in the skin and mediated at midbrain level. The chest and abdomen were the most sensitive areas in man, but chilling any large area on the trunk or limbs caused some increase in ventilation. Although the showers caused an inspiratory shift in respiration and a sensation of difficulty in breathing, they caused little increase in airway resistance and no decrease in pulmonary compliance. respiration; reflex; cold showers Submitted on May 15, 1964
Distribution of blood flow and the pressure-flow relations of the whole lung
Authors: West J. B. , Dollery C. T. 
Published: December 2017

Effects of changes in pulmonary arterial (Pa), venous (Pv), and alveolar (Pa) pressures on the over-all pressure-blood flow relations of an isolated dog lung have been re-examined. In the preparation used, the distribution of blood flow was predictable from previous measurements with radioactive gases. The results showed that the pressure-flow relations of the whole lung were greatly affected by the distribution of blood flow within it. For example, the pulmonary vascular resistance (PVR) of the lung depended on whether all the lung was perfused with blood or not, and thus whether there was an unperfused zone at the top of the lung where Pa was less than Pa ( zone 1). Again the pressure-flow relations of the lung were shown to depend on how much of the lung had a Pv less than Pa ( zone 2), and how much had a Pv which exceeded Pa ( zone 3). The effects on PVR of changing Pv or Pa could be explained on this basis. No evidence of a critical closing pressure in the vessels of the expanded lung was found. It was concluded that although the over-all pressure-flow relations of the whole lung were complicated, the flow through individual vessels could be accounted for by the simple mechanical effects of pressures inside and outside the vessels. hydrostatic effect; pulmonary vascular resistance; Starling resistor; vascular waterfall; critical closing pressure Submitted on May 4, 1964
Physical work capacity of college women
Authors: Michael Ernest D. , Horvath Steven M. 
Published: December 2017

Maximal exercise tolerance tests were given to 30 female subjects 17-22 years old. The test consisted of exercising 1 min at a work load of 300 kpm/min and increasing the work load 150 kpm/min each minute until the subject could no longer exercise. The maximal heart rate level averaged 184 beat/min with a range between 170 and 202 beat/min. The average maximal Vo2 was 1.78 liter/min or 29.8 ml/kg per min. The submaximal ventilatory measurements were similar for all subjects while the heart rate levels at the submaximal work loads differentiated the subjects when grouped according to maximal work-load capacities. Prediction of maximal work capacity could not be made for individuals from any single submaximal measurement. There was .56 correlation between body weight and maximal work capacity with only a .32 relationship between maximal Vo2 and Vo2 per kilogram body weight. exercise tolerance of women; cardiorespiratory function of women during exercise; submaximal cardiorespiratory response; maximal cardiorespiratory measurements of women; response to maximal exercise; prediction of exercise tolerance Submitted on May 5, 1964
Sudomotor and vasomotor responses to changing environmental temperature
Authors: McCook R. D. , Wurster R. D. , Randall W. C. 
Published: December 2017

Male subjects clad only in shorts were exposed in a climate chamber to a slowly rising ambient temperature while sweating, cutaneous volume pulses, and skin, tympanic membrane, and oral temperatures were simultaneously recorded. Mean skin temperature was continuously computed electronically. After sweating and vasodilatation had become well established, the copper screen bed on which the subject reclined was rapidly moved from the hot chamber into another, 20–30 C cooler. The onset of neither sweating nor vasodilatation could be accurately correlated with tympanic membrane temperature since the latter was observed to be either increasing, unchanged, or even falling during the period of recruitment. In some experiments, vasodilatation preceded sweating, while in others, it followed. When the subject was rapidly moved from the hot environment to the cold, sweating promptly stopped on all of the test areas, and profound vasoconstriction appeared on the palm. Nonpalmer areas, however, showed little or no immediate change in the amplitude of the volume pulses. Mean skin temperature invariably started to fall, but only by a few tenths of a degree when cessation of sweating and palmar constriction occurred. Tympanic membrane temperature during the same period continued to rise for 1–3 min, and thus seemed unrelated to either vasomotor or sudomotor control under these circumstances. sweating; cutaneous vasomotor responses; cutaneous vasodilatation; cutaneous vasoconstriction; tympanic membrane temperatures; mean skin temperatures; nervous control of sweating; nervous control of cutaneous vascular responses; bradykinin and sweating; bradykinin and vasodilatation Submitted on August 13, 1965
Effects of core temperature upon duration of hibernation of Citellus lateralis
Authors: Twente John W. , Twente Janet A. 
Published: December 2017

Continuous recordings of core temperatures by permanent thermocouples in 31 golden-mantled ground squirrels (Citellus lateralis) during the hibernating season indicate: 1) hibernating periods persisted longer at lower core temperatures, periods averaged approximately twice as long at 2 as at 11 C; 2) the duration of hibernating periods was relatively constant and predictable for individuals at given temperatures; 3) when two core temperatures were experienced during a single hibernating period and the time spent at each temperature expressed as a per cent of the predicted duration for each temperature, the sum of these percentages approximated 100%; and 4) less stimulus was required to evoke arousal as a hibernating period progressed. Based upon the time-temperature relationship, increased irritability as periods progressed and individual consistency, the termination of hibernating periods (arousal) was thought to be a triggering of the autonomic nervous system by an accumulation or depletion of factors exceeding the limits of the hibernating homeostasis. ground squirrel; arousal; hibernation induction; irritability; partial arousal; stimulus to arousal; homeostasis; thermocouple, permanent implantation Submitted on July 9, 1964
Aerobic work capacity in young Norwegian men and women
Authors: Hermansen Lars , Andersen K. Lange 
Published: December 2017

This paper deals with the problem of assessing the range of variability in work capacity of young adult Norwegians. Successful male athletes average 4.8 liter/ min or 71 ml/min per kg body weight in maximal oxygen uptake, versus 3.2 liter/min or 44 ml/min per kg body weight for a group of sedentary living men. Female athletes average 3.3 liter/min or 55 ml/min per kg body weight, compared to 2.3 liter/min or 38 ml/min per kg body weight for sedentary women. Oxygen cost of bicycling at submaximal work rates was the same in athletes and nonathletes, but with a clear sex difference, the females possessing a better work efficiency. The linear relationship between heart rate and oxygen uptake becomes curved in the least fit subjects (the sedentary women) when the exercise loads approach the maximal niveau. The maximal heart rate was found lower in athletically trained subjects. The exercise-induced hyperventilation takes place at an oxygen uptake corresponding to 70–80% of the capacity, this being the same in both sexes and uninfluenced by athletics. maximal O2 uptake Submitted on March 23, 1964
Pressure-flow relationships in the ascending aorta and femoral artery of man
Authors: Patel Dali J. , Greenfield Joseph C. , Austen W. Gerald , Morrow Andrew G. , Fry Donald L. 
Published: December 2017

Using a Kolin-Kado electromagnetic flowmeter and a 20-gauge needle connected to a Statham transducer, instantaneous blood flow and pressure were measured in the ascending aorta of 3 patients and in the common femoral artery of 11 patients. From the data obtained in the ascending aorta the peak blood flow, cardiac output, peak power, and stroke work were calculated. Harmonic analysis of the pressure and flow curves was carried out and the hydraulic input impedance series was calculated for each subject. The constant term (peripheral vascular resistance) was found to be about 12 times as large as the largest time-dependent impedance term. Similar analysis of the femoral artery data indicated: 1) the moduli of the hydraulic input impedance series dropped with frequency from an initially high constant term, and then varied slightly with frequency thereafter; and 2) the vascular resistance decreased to 75% of the control value during reactive hyperemia and increased to 232% of the control value following norepinephrine administration. hydraulic input impedance Submitted on June 4, 1964
Ventilation of liquid by the fetal lamb during asphyxia
Authors: Howatt W. F. , Humphreys P. W. , Normand I. C. S. , Strang L. B. 
Published: December 2017

Experiments were performed on fetal lambs, exteriorized by cesarean section, to study the ventilation of liquid during and after periods of umbilical cord occlusion. It was found that during and after the occlusion, the fetal lamb made strong ventilatory efforts with pleural pressures up to -68 cm H2O, which resulted in the displacement of volumes up to 17 ml in a single gasp. The total amount of liquid ventilated during cord occlusion was less than during the ensuing recovery period, when episodes of regular breathing at frequencies up to 30/min occurred. The ventilation of liquid was limited mechanically by a high flow resistance and inertance. Estimates of the amount of mixing likely to take place between inspired liquid and lung liquid were made by the injection and withdrawal of aliquots of 0.9% NaCl containing tracer amounts of I131-labeled albumen. Although the amount of each injected sample which mixed with lung liquid was rather small, it could be estimated that the large number of breaths which occurred during recovery from asphyxia could cause significant washout of lung liquid. initiation of ventilation; amniotic fluid; fetal lung Submitted on August 3, 1964
Catecholamines in plasma and urine at high altitude
Authors: Cunningham W. L. , Becker E. J. , Kreuzer F. 
Published: December 2017

The concentration of free epinephrine and norepinephrine in plasma and 24-hr urine samples, collected from members of the Dutch Monte Rosa expedition (July 1963) was investigated during 17 days at various altitudes up to 4,560 m. The results indicate that the levels of both plasma and urine catecholamines were elevated during the expedition, the plasma levels reaching a maximum towards the end of the 12 days sojourn at 4,560 m. In general there was a twofold increase in total catecholamine concentration in the samples collected at high altitude as compared to control values at sea level. This difference was due to a significant increase in the norepinephrine concentration; there was little change in epinephrine level. epinephrine and norepinephrine; sympathoadrenal activity Submitted on September 2, 1964
Splanchnic metabolism in exercising man
Authors: Rowell Loring B. , Masoro Edward J. , Spencer Michael J. 
Published: December 2017

Using a single injection of indocyanine green dye, estimated hepatic plasma and blood flow were determined in six normal young males during the 30th to 60th min of exercise requiring 10–12 kcal/min (2.04– 2.49 liters O2 per min). Subjects were fasted 15–18 hours. During hepatic flow measurements four determinations of splanchnic A-V differences of triglyceride (TG), free fatty acid (FFA), phospholipid (PL), ketone bodies, and glucose were made from radial arterial and hepatic venous sampling sites. Splanchnic A-V concentration differences for TG and PL varied randomly with time from positive to negative values indicating no net production whereas FFA was uniformly taken up by splanchnic organs at an average rate of 64 μm/min. Average splanchnic ketone body production was 20 mg/min and glucose production averaged 295 mg/min. Complete oxidation by skeletal muscle of lipid substrate released by splanchnic organs could account for less than 5% of total caloric expenditure; glucose production accounted for an average of 10.4%. One to two determinations of splanchnic A-V lactate, CO2, and O2 concentrations in four men indicated continued uptake of lactate (average 50 mg/min) during exercise with RQ values approaching zero. lipid metabolism; exercise, hepatic blood flow, and metabolism; energy metabolism Submitted on January 15, 1965
Influence of age and sex on exercise cardiac output
Authors: Becklake Margaret R. , Frank H. , Dagenais G. R. , Ostiguy G. L. , Guzman Carole A. 
Published: December 2017

Exercise cardiac output has been measured by an indirect Fick technique in 94 normal subjects (48 men and 46 women) whose ages ranged from 20 to 85 years. With increasing age, exercise cardiac output was found to be greater despite no such trend in oxygen uptake; in consequence, exercise arteriovenous oxygen difference decreased with age. These trends were seen in both sexes, though the age effects were apparent a decade earlier in men. In addition, in men the heart rate was lower and stroke volume higher with increasing age. By contrast, no age effect on exercise pulse rate was noted in women. When the sexes were compared, exercise cardiac output was higher in women of the younger two decades (20 to 39 years), a difference which was not apparent in subsequent decades. sex differences in exercise cardiac output; age differences in exercise cardiac output; stroke volume during exercise; oxygen pulse during exercise Submitted on January 13, 1965
Pressure-flow relations of human blood in hollow fibers at low flow rates
Authors: Merrill E. W. , Benis A. M. , Gilliland E. R. , Sherwood T. K. , Salzman E. W. 
Published: December 2017

Suspensions of human red cells in citrated plasma, in Ringer solution, and in Ringer solution containing albumin were passed through straight and curved glass and plastic hollow fibers (diameter range, 100–1,000 μ). Pressure-flow relations were measured over the pressure range of 0.1– 800 mm water, corresponding to a shear stress range of 0.01– 80 dynes/cm2. The suspensions were tested simultaneously in a rotational viscometer. It was found that red cell suspensions exhibit a yield shear stress only if the plasma protein fibrinogen is present. Experimental pressure-flow data in hollow fibers were in excellent agreement with rotational viscometer measurements and with analytical predictions based on the assumptions that blood flows as a homogeneous continuum and that the velocity at the wall is zero. Effects of tube surface characteristics and curvature on the pressure drop-flow rate relation were not discernible. microcirculation models; model blood flow; yield stress of blood; capillary blood flow and viscometry; fibrinogen and blood flow in hollow fibers; non-Newtonian flow of blood in hollow fibers Submitted on July 20, 1964
Contribution of thebesian veins to the physiologic shunt in anesthetized man
Authors: Ravin Mark B. , Epstein Robert M. , Malm James R. 
Published: December 2017

The purpose of the present study is to quantitate the contribution of the thebesian veins to the total physiologic shunt in anesthetized man. The subjects were adults, free of septal defects, who were undergoing a variety of open-heart procedures for the correction of diseased valves. The studies were completed following thoracotomy but prior to the placement of catheters. Subjects were anesthetized, intubated, and ventilated with a constant-volume respirator. Prior to blood sampling 100% oxygen was administered for at least 3 min. Samples were simultaneously drawn from the left atrium and the aorta and analyzed for Po2 with a microelectrode which had been calibrated with tonometered blood. Only studies in which aortic Po2 exceeded 150 mm Hg were accepted. Pco2 and pH were also measured. From the difference in Po2 between left atrium and aorta the contribution of left ventricular thebesian veins to the physiologic shunt was calculated using a modification of the shunt equation. Values found ranged from 0.12 to 0.43% of the aortic flow. Mixed thebesian oxygen content was assumed to be 6 vol % in this calculation, but the value chosen can be shown not to be critical. physiologic shunt; A-a difference Submitted on November 30, 1964
Blood Volume
Authors: Gregersen Magnus I. , Rawson Ruth A. 
Published: December 2017

M. I. Gregersen and Ruth A. Rawson, “Blood Volume” Page 321, line 23, should read: (See PDF) Page 321, line 25, should read: (See PDF) Page 322, line 9, should read: (See PDF) Page 323, line 2, should read: (See PDF) Page 323, line 3, should read: (See PDF) Page 327, line 28, should read: “Percentage fat = 1OO − (% water/0.73)” Page 327, line 33, should read: “Fat-free body weight = A + 0.563 (A − E)” Page 327, line 34, should read: “...where A = antipyrine space and E = 0.7 x thiocyanate space.”
Pacemaker‐Mediated Programmable Hypertension Control Therapy
Authors: Neuzil Petr , Merkely Béla , Erglis Andrejs , Marinskis Germanas , de Groot Joris R. , Schmidinger Herwig , Rodriguez Venegas Manuel , Voskuil Michiel , Sturmberger Thomas , Petru Jan , Jongejan Niels , Aichinger Josef , Kamzola Ginta , Aidietis Audrius , Gellér Laszlo , Mraz Tomas , Osztheimer Istvan , Mika Yuval , Evans Steven , Burkhoff Daniel , Kuck Karl‐Heinz , Simon Jaroslav , Dujka Libor , Machalek Libor , Király Ákos , Molnár Levente , Kovács Attila , Szabó Marianna , Kupics Kaspars , Ansaberga Ieva , Ansabergs Janis , Nesterovics Nikolajs , Barysiene Jurate , van Cruijsen Marc , Schellevis Mindel M. , Pezawas Thomas , Flores Emilio , Fullerton Demian , Beeftink Martine M.A. , Meine Matthias , Ascheim Deborah D. , Dizon Jose , Hanon Samuel , Hastings Harold 
Published: December 2017

Background

Many patients requiring a pacemaker have persistent hypertension with systolic blood pressures above recommended levels. We evaluated a pacemaker‐based Programmable Hypertension Control (
PHC
) therapy that uses a sequence of variably timed shorter and longer atrioventricular intervals.

Methods and Results

Patients indicated for dual‐chamber pacing with office systolic blood pressure (
oSBP
) >150 mm Hg despite stable medical therapy were implanted with a Moderato™ pulse generator that delivers
PHC
therapy. Patients were followed for 1 month (Run‐In period) with conventional pacing; those with persistent
oSBP
>140 mm Hg were included in the study and had
PHC
therapy activated. The co‐primary efficacy end points were changes in 24‐hour ambulatory systolic blood pressure and
oSBP
between baseline and 3 months. Safety was assessed by tracking adverse events. Thirty‐five patients met the initial inclusion criteria and underwent Moderato implantation. At 1 month,
oSBP
was <140 mm Hg in 7 patients who were excluded.
PHC
was activated in the remaining 27 patients with baseline office blood pressure 166±11/80±10 mm Hg despite an average of 3.2 antihypertensive medications. During the Run‐In period,
oSBP
and 24‐hour ambulatory systolic blood pressure decreased by 8±13 and 5±12 mm Hg (
P
<0.002), respectively. Compared with pre‐
PHC
activation measurements,
oSBP
decreased by another 16±15 mm Hg and 24‐hour ambulatory systolic blood pressure decreased by an additional 10±13 mm Hg (both
P
<0.01) at 3 months. No device‐related serious adverse effects were noted.

Conclusions

In pacemaker patients with persistent hypertension despite medical therapy,
oSBP
and 24‐hour ambulatory systolic blood pressure are decreased by
PHC
therapy. Initial indications are that this therapy is a safe and promising therapy for such patients.

Clinical Trial Registration

URL
:
http://www.clinicaltrials.gov
. Unique identifier:
NCT
02282033.