bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of the cutaneous circulation
Authors: Wright Harry M. 
Published: December 2017

Relationships between four commonly used indirect methods for study of the cutaneous circulation in intact, unanesthetized man were examined. Skin temperature, thermal conductance, volume plethysmography and the light absorption of the skin (as related to hemoglobin content) were simultaneously recorded on the upper extremities of normal young men as blood flow and blood content of the skin were changed by circulatory arrest, venous occlusion, indirect heating and cooling, and changes in position. Skin temperature and thermal conductance changed along parallel courses as blood flow was changed, while finger volume and reflectance of the skin to light of wavelength 550 mμ both changed in expected directions although along different courses, following passive congestion and de-congestion and changes in level of the hand relative to the heart. The advantages, disadvantages, and limitations of each of the methods in the study of cutaneous circulation in man are discussed and compared. measurement of circulation of skin; methods for measurement of cutaneous circulation; blood flow through skin; blood content of skin; skin Submitted on March 12, 1964
Comparison of CO2 rebreathing and acetylene methods for cardiac output
Authors: Klausen K. 
Published: December 2017

The cardiac output during rest and work was determined by a CO2 rebreathing method as suggested by Defares. The partial pressure of CO2 in the mixed venous blood (PvCOCO2) was calculated from the rise of the CO2 percent in a Grollman bag during rebreathing. In the rest experiments the partial pressure of CO2 in arterial blood (PaCOCO2) was obtained from analysis of alveolar samples taken by the Haldane-Priestley direct sampling method. In the work experiments the PaCOCO2 was calculated using the Bohr formula and a dead space estimated from Asmussen and Nielsen's data. The metabolic rate including both O2 uptake and CO2 output was determined by the Douglas bag method. In each experiment the acetylene method as described by Christensen was applied after the CO2 rebreathing method. The values obtained by the two methods were almost identical, the standard deviation for all experiments being ±7.3%, and were of the same magnitude as those obtained by others with the dye-dilution or direct Fick method both during rest and work. cardiac output at rest and work; arterial Pco2 and venous Pco2 at rest and work; stroke volume at rest and work Submitted on November 25, 1964
A large environmental chamber for the study of hypercapnia and hypoxia
Authors: Schwartz William B. , Silverman Leslie 
Published: December 2017

The design and operating characteristics of an environmental chamber which can maintain carbon dioxide concentrations between 1 and 20% and oxygen concentrations between 5 and 21% are described. The chamber, which measures 3.66 x 6.10 m (12 x 20 ft), permits acute and chronic studies to be carried out in either large animals or man. Multiple safety features serve to protect the occupants against failure of equipment or controls. The relative ease with which investigators can work in the chamber, the convenience of long-term operation, and the reliability of the system which controls the gas concentrations provide a unit which has proved useful for the investigation of a variety of physiologic phenomena related to hypercapnia. Preliminary observations indicate that acute and chronic studies of hypoxia will be equally feasible. acid-base; anoxia; respiratory acidosis Submitted on May 11, 1964
Nomogram for temperature correction or electrode calibration during Po2 measurements
Authors: Hedley-Whyte J. , Radford E. P. , Laver M. B. 
Published: December 2017

A nomogram has been constructed based on temperature correction factors needed when the O2 tension of an aqueous solution is measured after warming or cooling the solution in a sealed container. Since blood has a constant solubility relative to water at O2 tensions above 200 torr, this nomogram is suitable for use when measuring the O2 tensions of fully saturated blood. This nomogram may also be applied to calibrate an O2 electrode by a technique which avoids the need for special calibrating gases. relative solubility; O2 electrode; hypothermia; tonometry; Bunsen coefficients; hyperbaric oxygenation Submitted on October 12, 1964
Neutrophilic granulocyte kinetics in normal man
Authors: Alexanian Raymond , Donohue Dennis M. 
Published: December 2017

A method has been described for the labeling, separation, and estimation of radioactivity in samples of DFP32-tagged neutrophilic granulocytes. Studies were performed to identify the potential errors of this procedure, and it was then applied to a group of 12 normal men. A mean of 43% of transfused, labeled neutrophilic granulocytes was found in the circulation, resulting in the calculation of a mean maximum of 0.68 x 109/kg neutrophilic granulocytes in the total peripheral vascular pool. The mean half-time of disappearance of these cells was 3.8 hr, and a mean maximum neutrophile turnover rate through peripheral blood of 3.2 x 109/kg per day was calculated. The failure of labeled cells to disappear from the blood at an exponential rate suggested that the instantaneously equilibrating blood neutrophile pools may be in slower equilibrium with a larger, extravascular neutrophile compartment. Note: (With the Technical Assistance of Yvonne Betson and Ruth Henderson) DFP32; liquid scintillation counting of granulocytes; circulating and noncirculating blood neutrophile pools; extravascular neutrophile pool; neutrophilic granulocyte turnover Submitted on August 31, 1964
Some responses of humans to thermal radiation
Authors: Suggs Charles W. 
Published: December 2017

The effects of thermal radiation on heart rate, ventilation rate, and oxygen consumption rate were investigated at various conditions of dry-bulb temperature, air velocity, and exercise. Ventilation rate and oxygen consumption rate were essentially independent of thermal radiation under all the environmental conditions investigated. However, heart rate increased appreciably with increases in thermal radiation provided the environment was already warm or hot. In the range between 70 and 100 F dry bulb, a 7 F increase in mean radiant temperature was found to elicit the same average increase in heart rate as a 1 F increase in dry bulb. For a cool environment the response tended to be reversed with the heart rate decreasing as the environment was made more comfortable by the addition of thermal radiation. Exercise shifted the point at which this reversal occurred toward lower temperatures. heat stress; heart rate; thermal intensity Submitted on July 16, 1964
Blood O2 content measurements using the oxygen electrode
Authors: Laver Myron B. , Murphy Anna J. , Seifen Astrid , Radford Edward P. 
Published: December 2017

A method is described for determining the oxygen content in whole blood with the membrane-covered oxygen electrode that requires less time and skill than the Van Slyke-Neill technique. A blood sample (0.05 ml) is mixed with a large volume of dilute (0.2% w/v) potassium ferricyanide solution in equilibrium with ambient air and the oxygen tension of the mixture is measured at a known temperature. The whole-blood oxygen content is obtained by subtracting the calculated O2 content of the ferricyanide solution from that of the blood-ferricyanide mixture. The method is based on the assumption that the Bunsen O2 solubility coefficient of the ferricyanide solution, with or without the added blood sample, is equal to the solubility coefficient of water. Data have been presented to validate this assumption. Whole-blood O2 contents measured simultaneously with the oxygen electrode and the Van Slyke-Neill technique were found to be in close agreement. flood-gas determination Submitted on January 11, 1965
Pulsatile flow in rigid tubes
Authors: Linford Robert G. , Ryan Norman W. 
Published: December 2017

The purpose of this study was to examine critically the theoretical equations derived for pulsatile laminar flow in rigid straight tubes. These equations, presented in their most useful form by J. R. Womersley in 1955, give the fluid flow rate as a function of the pressure gradient-time relationship, pulse frequency, fluid properties, and tube radius, and they give the fluid velocity as a function of the above quantities and the radial position in the tube. A pulsatile flow apparatus was constructed which would allow measurement of all the variables mentioned above, and a computer program based on Womersley's equations was used to calculate the fluid flow rate and velocity profile from the pressure gradient-time relationship, fluid properties, and tube radius. Thus a comparison between measured and calculated values of flow and velocity could be made. Calculations and data agree within the estimated experimental error, thus providing evidence of the applicability of the theoretical equations to actual flow with large pulse amplitudes. The analog computer “pressure gradient technique” of D. Fry and associates was compared with the exact solution for straight rigid tubes and found to deviate less than 20% in amplitude and phase except at very low frequencies. hydrodynamics, pulsatile flow; blood flow, arterial; hemodynamics, pulse characteristics Submitted on April 6, 1964
Effects of changes in topographical distribution of lung blood flow on gas exchange
Authors: West John B. , Jones Norman L. 
Published: December 2017

The left lung of a dog was suspended in a Lucite box, ventilated with negative pressure, and perfused with venous blood from another dog at 37 C. By varying the pulmonary artery pressure, it was possible to perfuse all the lung or leave increasing proportions of the upper and middle lobes unperfused. The mean Pco2 difference between end-tidal gas and pulmonary venous blood was 1.7 mm Hg (se mean 0.6) when all the lung was perfused, but steadily increased up to 17 mm Hg as more and more of the lung was unperfused. Alveolar dead space/alveolar tidal volume increased linearly with the proportion of lung unperfused. By contrast, the venous admixture component remained small as increasing amounts of lung were unperfused. The results were compared with calculations made on a theoretical model of the lung and it was concluded that the uneven distribution of blood flow caused by hydrostatic pressure differences down the lung may seriously interfere with CO2 exchange when the pulmonary artery pressure is low, but that this type of uneven distribution affects O2 exchange much less. isolated lung; hydrostatic effect; alveolar-arterial differences; physiologic dead space; alveolar dead space; shunt effect; venous admixture; increased acceleration; hypoxemia; hemorrhage; positive-pressure breathing Submitted on September 10, 1964
Effect of CO2 and whole-body vibration on ventilation
Authors: Young W. A. , Shaw D. B. , Navach J. , Shizgal H. , Kowalsky N. 
Published: December 2017

The ventilatory response of six subjects to increasing levels of alveolar CO2 was measured at rest and during the hyperventilation induced by passive vibratory movements of the whole body. During vibration, addition of CO2 to the inspired air produced no increase in ventilation until the PaCOCO2 reached a critical level which coincided closely with the intersection of the vibration with the resting CO2 response curve. Above this level the vibration curve was almost superimposed on the resting one. There was no evidence of an additive effect of the two stimuli, and no increase in sensitivity to CO2 during vibration. In these respects the situation differs from that in which CO2 is combined with hypoxia or hyperthermia. The findings indicate that when respiration is stimulated by vibration and CO2 simultaneously, the resultant ventilation at any point is solely that produced by the stronger of the two stimuli. hyperventilation; PaCOCO2 and ventilation; CO2 response curve and vibration Submitted on July 30, 1964
Altered surface tension of lung extracts and lung mechanics
Authors: Tierney D. F. , Johnson R. P. 
Published: December 2017

Reduction of the surface area of 24 extracts of rabbit lungs by four-fifths decreased the surface tension to a minimum value of 0–5 dynes/cm at 18–22 C. However, minimum surface tension was above 15 dynes/cm if 1) the temperature was raised to 42 C, 2) the extract was prepared with distilled water, 3) phospholipase C was incubated with the extract, and 4) cholesterol or oleic acid was added to the surface. If blood or serum was added during the extraction, minimum surface tension was usually (although not invariably) elevated. Rinsing diluted rat serum or chylomicrons through the airways increases elastic recoil of excised rat lungs. Other reports show that heating a lung above 42 C or rinsing a solution of phospholipase C through the airways also increases elastic recoil of excised rat lungs. Therefore, these conditions alter the surface tension of lung extracts and the pressure-volume characteristics of the lungs concordantly. In addition, we found that the surface tension of lung extracts was not stable below 24 dynes/cm. Similar instability of the surface within the lung should lead to gradual atelectasis if a low transpulmonary pressure is maintained. elastic recoil; atelectasis; compliance; lung surface Submitted on January 21, 1965
Critical temperature for instrumental response acquisition in hypothermic rats
Authors: Panuska J. A. , Popovic V. P. 
Published: December 2017

Fifty-one previously untrained adult white rats were cooled to colonic temperature of 18.5 C and were rewarmed to various body temperatures between 23 and 31 C. After their body temperature stabilized at a chosen level, rats were placed in a chamber with the possibility of using a lever-activated heat reinforcement apparatus. The temperature of the chamber was 2 C. Each experiment lasted 180 min. During this time the rats either started to press the lever steadily for external heat or at the end of this experiment they became even more hypothermic. In a group of 41 rats kept at a body temperature of 25 C or above, 38 animals used the simple heat reinforcement apparatus and responded effectively, thus rewarming themselves to euthermia. Animals at a higher body temperature acquired the response earlier than animals whose body temperature was lower. When the body temperature was 25 C or below, the rats failed to acquire the response. Thus it appears that body temperature of 25 C is a critical body temperature for this simple response acquisition. behavioral temperature regulation; body temperature; heat reinforcement; hypothermia; learning; performance Submitted on April 1, 1965
Body temperatures in some Australian mammals. V. Aboriginals
Authors: Morrison Peter 
Published: December 2017

Skin temperatures were measured on nine body areas with a portable radiometer at the beginning and at the end of a night of sleep in early summer. The subjects, young Australian aboriginal men and women from Haast's Bluff, slept in their normal circumstances outside on the ground with little protection. With some cover or on warmer, cloudy nights (average air temperature of 26.5 C), there were no losses in temperature beyond the expected nocturnal decline. With minimal cover on clear, cool nights when temperatures ranged down to 19 C for air and ground and to 4 C for sky, substantial losses were found for the 6-hr period: 33.2–30.4 C for the forehead; 27.7– 20.8 for the feet; 30.5–27.2 for the mean of the exposed skin; and 37.0–35.1 for the mouth. The maintenance of sleep at this level of cooling (minimum foot value = 17.6 C) represents a valuable adaptation in these people. Tropical aboriginals from Mornington and Bentinck Islands did not exhibit this tolerance, and insisted on cover even on warm nights (air temperature of 27 C) which did not depress skin temperature. cold; skin temperature; adaptation Submitted on December 21, 1964
Renal clearances during prolonged supine exercise at different loads
Authors: Grimby Gunnar 
Published: December 2017

Clearance of inulin (CIn) and para-aminohippuric acid (CPAH), cardiac output, oxygen uptake, and arterial blood pressure were measured in 15 healthy male subjects at rest and during supine exercise of 45 min duration on a bicycle ergometer. Work loads between 150 and 900 kpm/min were chosen. CPAH decreased with increasing work intensity (heart rate). At an oxygen uptake corresponding to half of the aerobic work capacity it was about 70% and at heavy work 35–45% of the value at rest. The renal fraction of the cardiac output averaged, at rest, 17% and decreased with increasing work loads to 2.5–5% as a minimum. CIn did not change significantly until heavy exercise was performed. The filtration fraction increased during exercise. clearances of inulin and para-aminohippuric acid; cardiac output Submitted on May 28, 1965
Excess lactate concept and oxygen debt of exercise
Authors: Wasserman Karlman , Burton George G. , Van Kessel Antonius L. 
Published: December 2017

The Huckabee concept that “excess lactate” (XL) is equivalent to the O2 debt of exercise and physiological phenomena derived therefrom, were investigated. Measurements of O2 debt, arterial blood lactate and XL, and O2 consumption were made during cycle ergometer exercise of controlled intensity and duration. Our results indicate: 1) The oxygen equivalents of XL as well as Delta lactate are less than the O2 debt, at all work loads. 2) The concentration of XL does not linearly increase during exercise. 3) The anaerobic metabolic rate whether calculated from XL or O2 debt is not a constant fraction of the metabolic rate, at all work loads. A larger fraction of energy is derived from the O2 debt creditors at heavy and very heavy than at moderate work loads. 4) In 30 controlled work-load exercise studies of prolonged duration, XL did not contribute any information not revealed by lactate itself. 5) The differences between Huckabee's results and those of our own are not due to differences in the measurement of XL but rather to differences in the directly measured O2 debt. anaerobic metabolism; O2 debt creditors; O2 consumption Submitted on January 4, 1965
A nonthrombogenic diffusion membrane for continuous in vivo measurement of blood gases by mass spectrometry
Authors: Brantigen J. W. , Gott V. L. , Vestal M. L. , Fergusson G. J. , Johnston W. H. 
Published: December 2017

A heparinized silicone rubber diffusion membrane covering a 22-gauge stainless steel intravascular cannula allows continuous in vivo measurement of blood gas tensions by mass spectrometry in an unheparinized animal or patient. This system has been tested in the aortas of a series of five dogs for periods up to 24 hr, and nonheparinized controls have been used in two dogs. The controls showed evidence of membrane coagulation, but the heparinized membranes were non-thrombogenic and provided quantitatively accurate measurements of Po2 and Pco2 throughout. nonthrombogenic materials; blood gas tensions; oxygen; carbon dioxide; monitoring devices Submitted on July 18, 1969
Collection of normal canine tracheobronchial secretions
Authors: Adams G. K. , Aharonson E. F. , Reasor M. J. , Proctor D. F. 
Published: December 2017

A technique is described for the collection of tracheobronchial secretions from the upper trachea of anesthetized dogs. The method is simple, relatively quantitative, and provides secretory material in quantity suitable for biochemical or rheological studies. In 42 experiments comprising 184 individual samples we have found the collection rate of tracheobronchial secretions to be 1.0 ± 0.1 mg/min per kg (mean ± SEM). airway mucus; trachea; anesthetized dogs Submitted on June 11, 1975
Antibody Formation
Authors: Haurowitz Felix 
Published: December 2017

Felix Haurowitz, “Antibody Formation” Page 46, volume 45, references 294–296, printer's error, should read: 294. PORTER, R. R. Biochem. J. 46: 473, 1950. 295. PORTER, R. R. Biochem. J. 73: 119, 1959. 296. PORTER, R. R. Brit. Med. Bull. 19: 197, 1963.
Stent and Dual Antiplatelet Therapy Duration Comparisons in the Setting of a Multicenter Randomized Controlled Trial: Can the Operator Experience Affect the Study Results?
Authors: Gargiulo Giuseppe , Heg Dik , Ferrari Fabrizio , Percoco Gianfranco , Campo Gianluca , Tumscitz Carlo , Colombo Federico , Zuffi Andrea , Castriota Fausto , Cremonesi Alberto , Windecker Stephan , Valgimigli Marco 
Published: December 2017

Background
Operator experience influences outcomes after percutaneous coronary intervention, but this association in the controlled setting of a randomized, clinical trial is unclear.

Methods and Results

We investigated operator‐related outcomes (30‐day and 2‐year efficacy and safety end points) among patients undergoing percutaneous coronary intervention and randomized to different dual antiplatelet therapy durations and stent types. A total of 2003 patients were analyzed, and 7 operator groups were compared. The majority of preprocedural and postprocedural characteristics were imbalanced. The primary end point of the study, the composite of death, myocardial infarction, or cerebrovascular accidents, did not differ among operators at 30 days or 2 years. There were no significant differences also for all other individual and composite end points analyzed at 30 days and 2 years, except for 2‐year stent thrombosis (
P
=0.048) and bleeding events (
P
=0.022 for Bleeding Academic Research Consortium type 2, 3, or 5). Adjusted comparisons for the main end points showed slight differences among operators at 30 days, but not at 2 years. There was no interaction of operator with dual antiplatelet therapy duration (
P
=0.112) or stent type (
P
=0.300). Results remained entirely consistent when operators were stratified by their experience.

Conclusions
There was a weak signal of heterogeneity across study operators for the 30‐day, but not the 2‐year, main study outcomes. No clear effect of operator or operator experience was observed for the comparative efficacy and safety profile of the randomized stent types or dual antiplatelet therapy duration regimens.

Clinical Trial Registration

URL
:
http://www.clinicaltrials.gov
. Unique identifier:
NCT
00611286.