bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new type of electronic cable for chronic implantation in living tissue
Authors: Colwell Robert K. 
Published: December 2017

A new type of electronic cable was developed to fill the need for a means of conducting electrical signals through areas of living tissue without disturbing normal function or inducing tissue reaction. The cable consists of a multiconductor braided cable encapsulated in transparent silicone resin. A simple and inexpensive method is described for producing cables of this type with a diameter as small as 1/16 in. Possible applications are found in the field of bioinstrumentation, and in biometric and medical research. Submitted on February 25, 1963
Relationship between ambient temperature and acetylating capacity of human blood
Authors: Blondheim S. H. , Neumann Gabriel , Kott Edna , Ben-Ishai Zena 
Published: December 2017

The ability of human blood to acetylate p-aminobenzoic acid, determined in vitro, varied directly with the ambient temperature to which the subject was exposed before the blood was drawn. This was demonstrated by 135 determinations of the acetylating ability of the blood of 49 subjects performed over a period of 3 years, and also in acute experiments in which subjects were exposed to 6 and 37 C for up to 2 hr. Variations in the acetylating ability of blood may reflect the activity of metabolic mechanisms involved in thermal homeostasis. aromatic amines; p-aminobenzoic acid; cold; heat acclimatization; (blood) enzymes; weather; environment Submitted on September 11, 1962
Bilateral differences in forearm blood flow as measured with capacitance plethysmograph
Authors: Hyman Chester , Burnap Donald , Figar ŠtĚpán 
Published: December 2017

The electrocapacitance plethysmograph has been modified and tested for the measurement of blood flow through the forearm of normal, resting individuals. Data obtained indicate a small but consistent and significant difference between the blood flow of the two arms of a given individual at any time. This asymmetry is discussed and reasons are presented which make it seem likely that the differences are in blood flow through the skin rather than through muscle. The electrocapacitance plethysmograph was compared with the segmental plethysmograph in careful determinations on a group of subjects and it was found that the apparent blood flow as measured with the segmental plethysmograph tends to decrease as the pressure in the segmental cuff increases and that the differences between the blood flows in the two arms noted above becomes almost impossible to detect with segmental plethysmograph pressures above 15 mm Hg. When the capacitance plethysmograph is compared with the segmental plethysmograph inflated to minimal pressures in a series of acute measurements the correspondence is completely acceptable. Submitted on December 17, 1962
Threshold Pco2 for respiratory system in acute hypoxia of dogs
Authors: Honda Yoshiyuki , Natsui Teijiro , Hasumura Nariko , Nakamura Keiko 
Published: December 2017

Threshold alveolar-arterial Pco2 (PtCOCO2) for the respiratory system in acute hypoxia of anesthetized dogs was examined by observing phrenic nerve discharges. It was found that 1) the lower the alveolar Po2, the lower the PtCOCO2. The relationship between the PaOO2 and the PtCOCO2 was curvilinear, PtCOCO2 showing an abrupt fall in the range of PaOO2 of 30–60 mm Hg. 2) The respiratory drive induced by hypoxia was completely extinguished by lowering alveolar Pco2. Thus it was proved that, during intense hypoxia, respiratory drive continues to be attributable to Pco2 or cH, even when they have been reduced far below normal. 3) Ventilatory response related to the hypoxic drive with other parameters constant was calculated from the nonhypoxic and hypoxic PtCOCO2 differences and from the ventilatory coefficients. It was then inferred that a positive interaction between Po2 and Pco2 or cH stimulus for ventilation exists when PaOO2 falls below about 70 mm Hg. Pco2 levels in acute hypoxia; dogs
Some effects of vibration on totally immersed cats
Authors: Pape R. W. , Becker F. F. , Drum D. E. , Goldman D. E. 
Published: December 2017

A survey has been made of the physiological and pathological changes occurring when anesthetized totally immersed cats are exposed to vertical sinusoidal vibration. Twenty-five of 55 cats survived exposure to 15 G peak acceleration for periods averaging 47 min. A decrease in peak acceleration from 15 to 10 G caused a large decrease in mortality. Time of exposure, within the limits of 5–120 min, also affected mortality, but much less strikingly than acceleration. The heart rate and mean respiratory rate are little changed during severe vibration. Respiration becomes irregular, and the tidal volume is greatly depressed. At 15 G peak acceleration, electrocardiographic changes of ischemia and injury occur, especially in those cats which die later. The most significant gross pathological findings are pulmonary collapse and hemorrhage, involving especially the peripheral parts of the lower lobes, and gastrointestinal hemorrhage. The major changes appear to be related to vascular change, either by rupture, leakage, or changes in tone. The resulting ischemia contributes to tissue damage and death. There is both clinical and pathological correlation between the intensity of the forces applied and the response. vertical sinusoid vibration; gravity acceleration; heart rate; respiration Submitted on August 27, 1962
Measurement of lung diffusing capacity by means of C14O in a closed system
Authors: S⊘lvsteen Paul 
Published: December 2017

A method of measuring the lung diffusing capacity (Dl) with radioactive carbon monoxide (C14O) and nonuniformity of ventilation with nonabsorbable gas in a closed system is described. Treating ventilation as a continuous phenomenon and disregarding dead space, the mathematical equations for uniform and nonuniform ventilation (two lung regions ventilated in parallel) are derived. It is proved that sooner or later the curve for carbon monoxide, plotted on semilogarithmic paper, will be rectilinear. Experiments in six normal subjects and eight patients with chronic lung disease are described. Determinations of the distribution of the ventilation and the Dl are made in separate experiments. Since the method is unreliable at high Dl values, many of the Dl estimations are performed at high oxygen tension, which reduces the apparent Dl. It is shown that the assumption of a uniform distribution of Dl to lung volume explains the experimental findings better than the assumption of a uniform distribution of Dl to alveolar ventilation. Dl was decreased in four of the eight patients. mathematics of uniform and nonuniform ventilation; distribution of lung diffusing capacity in relation to lung volume and alveolar ventilation; N2 curve for use in calculating alveolar ventilation and regional lung volumes; CO curve for use in calculating lung diffusing capacity; diffusing capacity of lung determined with a closed system Submitted on October 15, 1962
Measurement of factors impairing gas exchange in man with hyperbaric pressure
Authors: Lenfant C. 
Published: December 2017

Alveoli with very low ventilation/perfusion ratios (Va/Q) contribute capillary blood with venous saturation to the mixed arterial stream. The portion of the alveolar arterial oxygen difference (A-a Do2) due to these units with very low Va/Q ratios cannot be differentiated from that due to an anatomical shunt at ambient pressures. By raising the barometric pressure to such a level that venous blood is saturated, the O2 dissociation curve no longer affects the A-a Do2 measurement, and the differentiation can be made. In the present experiments 75% O2 was inspired at sea level and at a depth equivalent to 2.6 atm. The A-aD was measured for O2, CO2 and N2. In seven out of eight subjects A-a Do2 and A-a Dn2 varied when the barometric pressure was increased. A theoretical analysis showed that the results can be interpreted on the basis of a bimodal distribution of Va/Q composed of a large group of well-ventilated alveoli and of a small group of units having an undeterminable Va/Q. The shunt calculated from the total A-a Do2 at sea level was 3.47% of the total cardiac output. When the A-a Do2 due to Va/Q (i.e., A-a Dco2 + A-a Dn2) was subtracted from the total A-a Do2 the shunt was 1.78%. At 2.6 atm that part of the total A-a Do2 found to be due to shunt was 0.8%, or 25% of the shunt estimated at sea level from the pure O2 technique. pulmonary shunts; ventilation/perfusion distribution; diving; hyperbarism Submitted on June 24, 1963
Reflex control of abdominal muscles during positive-pressure breathing
Authors: Bishop Beverly 
Published: December 2017

Continuous positive-pressure breathing initiates expiratory activity in the abdominal muscle and inhibits the diaphragm in anesthetized cats. This investigation defines neural mechanisms involved in this abdominal muscle response (AMR) to positive-pressure breathing. The AMR is not a segmental reflex since it is abolished by thoracic spinal transection. Bilateral rhizotomy (T8-L3) also eliminates AMR, but laparotomy and abdominal evisceration do not, suggesting that some neural inflow other than from abdominal muscle or viscera is necessary but insufficient for maintaining AMR. Abdominal vagotomy failed to interrupt AMR which was abolished by bilateral cervical vagotomy, indicating that the necessary receptors lie in the thorax. Compression or local anesthesia of the cervical vagi provided the experimental means for abolishing either the inhibition of the diaphragm or the AMR without necessarily interrupting the other. That one response may persist in the absence of the other indicates that vagal afferent pathways subserving AMR are distinct from those mediating diaphragm inhibition. Hence the active expiration of pressure breathing is not a simple corollary of the Hering-Breuer inflation reflex but is a separate reflex served by its own vagal pathway. abdominal muscle response; vagus control of active expiration; abdominal muscle motoneuron pool; vagal afferent pathway in pressure-breathing reflex; thoracic receptors; diaphragm response to pressure breathing; diaphragm; inspiration; expiratory reflexes; inspiratory reflexes; respiratory reflexes; segmental reflexes; spinal reflexes Submitted on February 21, 1963
Nature of purines excreted in urine during muscular exercise
Authors: Nasrallah Salah , Al-Khalidi Usama 
Published: December 2017

The purines which were previously noted to increase in the urine during muscular exercise have been identified as hypoxanthine and xanthine. Quantitative studies on 11 human subjects showed that the magnitude of the increase in excretion of hypoxanthine varied greatly and reached up to 20-fold in some cases. The increase in the excretion of xanthine was less pronounced with the maximum about threefold. xanthine and hypoxanthine excretion Submitted on August 8, 1963
Effects of aspartic acid salts (Mg and K) on swimming performance of rats and dogs
Authors: Matoush Le Roy O. , Consolazio C. Frank , Nelson Richard A. , Isaac Gerhard J. , Torres Juan B. 
Published: December 2017

Five separate experiments were performed to evaluate the effects, if any, of Mg and K salts of aspartic acid on the swimming times of rats and dogs. Experiments 1 and 2 were with rats doing a single swim-to-exhaustion in water maintained at 17 C and 25 C. In experiment 3 dogs performed a single swim-to-exhaustion in 17 C water. During the first three experiments each animal underwent two treatments; a no-treatment control, and an aspartate therapy. Experiment 4 was a long-term single swim-to-exhaustion test. The rats were divided into two groups: one group receiving a placebo and the other group receiving aspartate. Each group swam to exhaustion in 25 C water twice a week for 6 weeks. Experiment 5 was of the same experimental design as experiment 4 with the exception that a double swim-to-exhaustion was used to measure performance. Statistical analysis of the mean swimming times for both rats and dogs in the five experiments showed that average swimming times under control and aspartate therapy were not significantly different. exercise; ergogenic drugs; swimming time to exhaustion endurance criterion Submitted on May 8, 1963
Thin-layer chromatography of component A of the menstrual stimulant
Authors: Clitheroe H. J. 
Published: December 2017

Thin-layer chromatography has been adapted to separate material of high biological potency from much of the inactive material contained in component A of the menstrual stimulant. The chromatoplates were developed with solvent mixture of chloroform, methanol, and water (60:10:1). Visualization of the spots was carried out by various methods; ultraviolet fluorescence of the charred material appeared to be the most sensitive. Samples of ricinoleic and phloionolic acids were used as reference standards. The biological active material of the component A preparations always ran just in front of phloionolic acid. Menstrual fluid was collected in vaginal cups; total volume and crude liquid extract measurements were also carried out on the fluid. uterine smooth muscle stimulant; menstrual flow rates Submitted on October 1, 1963
Gaseous diffusion from alveoli into pulmonary arteries
Authors: Jameson A. Gregory 
Published: December 2017

In 40 patients, during right heart catheterization a catheter with a platinum tip electrode was wedged in a branch of the pulmonary artery. With the electrode acting as part of a potentiometer, signals were recorded following single inhalations of hydrogen. Similarly signals were recorded following inhalations of oxygen with the electrode acting as part of a polarograph. With either gas, signals were recorded appearing in less than 1 sec after the gas entered the nose. The signals paralleled the changes in the alveolar concentration of the gas. The infusion of dextrose through the wedged catheter or the withdrawal of the catheter a short distance from the wedged position, did not significantly affect the results. The inhaled gas was also shown to appear at the tip of the wedged catheter significantly before it appeared in the descending aorta. It is concluded that the observations made are evidence of diffusion of the inhaled gases from the alveoli directly into the pulmonary arteries. platinum/hydrogen anode; oxygen polarograph; alveolo-arterial oxygen diffusion; alveolo-arterial hydrogen diffusion Submitted on May 29, 1963
Fibrinolytic activity and muscular exercise in heat
Authors: Bedrak E. , Beer G. , Furman K. I. 
Published: December 2017

The fibrinolytic activity of whole blood is increased by exposure to environmental heat stress. The increased fibrinolytic activity of muscular exercise is further increased if the muscular activity is performed in heat. In resting or exercising subjects who are heat acclimatized, the increased fibrinolytic activity due to heat exposure is less than that which occurs in the unacclimatized state. fibrinolysis and heat acclimatization in man; heat stress, exercise, and blood fibrinolytic activity Submitted on September 4, 1963
d-Aldosterone and sweat electrolytes
Authors: McConahay T. P. , Robinson S. , Newton J. L. 
Published: December 2017

Men worked (BMR 190 kcal/m2 hr) in the heat (45–50 C D.B.; 26 C W.B.) for periods of 5–7 hr, maintaining water and salt balance by drinking appropriate saline solutions. d-Aldosterone was administered by continuous intravenous infusion at 1.5 µg/kg hr during the third to seventh hours without altering the Na or Cl concentration of the men's sweat from control values determined during the first 2 hr of the exposures, or from the values observed during separate control experiments. Na and Cl concentrations of sweat secreted the day following the infusion experiments were not significantly different from those of samples collected the day after control experiments. The sodium-conserving responses of the men's sweat glands 7–24 hr following salt depletion (-140 to -230 mEq) were not significantly altered by infusion of 2.0–4.5 µg/kg hr of d-aldosterone. Continuous infusion of d-aldosterone at 1.8 µg/kg hr into one brachial artery did not alter the Na or Cl concentration of sweat being secreted by the infused arm, either from simultaneously collected samples from the man's other arm or from control values in both arms before the infusion was started. In all cases, pronounced reductions in urinary Na:K ratios were observed during and after d-aldosterone administration. Submitted on October 28, 1963
Ventilatory mechanics in hypovolemic shock
Authors: Cahill John M. , Byrne John J. 
Published: December 2017

In order to study ventilatory mechanics in shock, dogs were bled arterially into a reservoir, the height of which was regulated to keep the mean blood pressure of the animal at approximately 30 mm Hg. When the animal “took up” 40% of his maximal shed volume of blood (2–3 hr), the remainder of the blood was reinfused and the animal assumed to be in irreversible shock. Studies throughout the stages of hypovolemic and irreversible shock revealed a significant rise in lung compliance and a fall in combined viscous and air-flow resistance initially if the animal's lungs were carefully inflated prior to each study. As shock continued, there was a tendency for the lung compliance and resistance to air flow to return in the direction of the control values. Submitted on October 29, 1962
Recording viscometer for nonhomogeneous biological fluids
Authors: Dworkin B. R. , Wolach A. , Necheles H. 
Published: December 2017

Viscosity of secretions can change quickly from very thin to rather viscid consistency, and available viscometers cannot provide specific information on each fraction of mixed specimens. For this reason we are describing a viscometer that determines the entire viscosity spectrum of a given sample of secretion. The instrument registers the rate of flow of each aliquot of a fluid as it passes through a short narrow-gauge tube under constant pressure. The fluid is driven out of a syringe by a servo-controlled drive mechanism, and through a manifold (1 ml volume) to which a pressure transducer and a hypodermic needle are attached. The pressure in the manifold is kept constant by an electronic feedback loop. A permanent-magnet motor is coupled to the d-c drive motor of the syringe, producing an electric signal proportional to the drive velocity. The instrument has been in satisfactory use for 1 year. biological servo-mechanisms; biological analog computer; hydraulic analog computer; nonhomogeneous viscosities Submitted on November 12, 1963
Pressure-volume studies on lung lobes in man
Authors: Ishikawa Koh , Martin C. J. , Young A. C. 
Published: December 2017

This study has sought to measure pressure differences occurring within the chest cavity and some of the mechanical properties of lung lobes. One lobe in the hemithorax has been used as an intrapleural pressure capsule by blocking it with a catheter and balloon system. After insertion of an esophageal, a bronchospirometric, and a lobar pressure-measuring catheter, the interrupted vital capacity maneuver has been used to compare pressures within the lungs and esophagus. Pressure differences, which increased as lung volumes increased, were found between lobes, and between lobes and esophagus. Esophageal pressure swings were of lower magnitude than lobar pressure swings. Esophageal pressure was neither linearly related to lobe pressure nor a mean pressure for the hemithorax. Thus, lung volume is not a function of a single pressure within the chest, and the concept of the commonly used pressure-volume curve is oversimplified. mechanical properties; pressure capsules Submitted on October 18, 1963
Effect of environmental temperature on hamster body fat composition
Authors: Kodama Arthur M. , Pace Nello 
Published: December 2017

Body fat content and the melting point and fatty acid composition of body fat of hamsters exposed to 35, 27, 20, 15, 10, and 6 C for 2 weeks were determined. The relationship between exposure temperature and body fat content and composition resembled that between environmental temperature and metabolic rate. Below the critical temperature, there was a progressive decrease in total body fat content and melting point accompanied by a decrease in the mole fraction of palmitic acid and an increase in the mole fraction of oleic acid. The softening of body fat in cold-exposed animals appears to be the result of an increased mobilization of depot fat in response to a higher metabolic rate in the cold, a mobilization which is at least partially selective with respect to individual fatty acids or triglycerides. Examination of changes in whole body composition revealed that 72% of the loss in body weight of hamsters exposed to 6 C was due to a decrease in body fat content. In contrast, the decrease in body fat content accounted for only 28% of the body weight loss of pair-fed hamsters kept at 27 C on reduced caloric intake to match the body weight loss experienced by cold-exposed animals. It appears, therefore, that cold exposure induces a more effective fat depot mobilization than does reduced caloric intake. heat exposure; cold exposure; body composition Submitted on February 3, 1964
pH-temperature conversion factors and pCO2 factors for hypothermia
Authors: Austin William H. , Lacombe Eleanor H. , Rand Peter W. 
Published: December 2017

The change in pH per degree centigrade was re-evaluated in a series of normal and ill adults. The results indicate that the ΔpH per degree centigrade is relatively constant in a given individual and of the order of -.015 for every degree increase in the temperature. Errors in hypothermic work may be minimized by using a water-bath setting midway between the highest and the lowest temperatures anticipated. These findings tend to support previous figures in both magnitude and range. Procedural accuracy is emphasized and technical difficulties in pH measurements are suggested as possible sources of disagreement raised by one investigator. "pCO2 factors" are given for temperatures from 20 to 38 C for rapid calculation of pCO2 from CO2 content and pH corrected for temperature. CO2, partial pressure conversion factors in hypothermia; hypothermia, pH, and pCO2 factors; acid-base metabolism and hypothermia Submitted on October 25, 1963
Lung volumes and breathing patterns in wind-instrument players
Authors: Bouhuys Arend 
Published: December 2017

Pulmonary function at rest and physiological performance during play was studied in 42 professional wind players on 15 different instruments. Vital capacity was larger than expected from age and height in all brass players. Other lung function results were similar to or better than those in control subjects. Breathing patterns are qualitatively similar in players of nearly all instruments; rapid and deep inspirations are followed by prolonged expirations through the instrument. In some instruments nearly the whole vital capacity may be used during play. No gross changes in arterialized capillary blood pH, Pco2 and standard bicarbonate content occurred during frac12 hour's play. Mouth pressure on most instruments increased both with pitch and loudness and varied from 2.5 to 158 mm Hg. Air flow rates varied from less than 0.05 to over 1.6 liters/ sec. Performance on some, mainly brass, instruments is limited mechanically; on others, e.g., the oboe, breath-holding time is the limiting factor. Energy expended on the instrument (mouth pressure times flow rate) ranged from less than 0.1 up to 17 w. pulmonary function; respiratory mechanics Submitted on January 13, 1964