bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface characteristics of vertebrate lung extracts
Authors: Miller Dean A. , Bondurant Stuart 
Published: December 2017

It has been suggested that alveolar stability is due, in part, to the presence of a noncellular alveolar lining which changes surface tension with changing surface area. Extracts of mammalian lungs manifest a decrease in surface tension with decrease in surface area. To compare surface characteristics with respiratory mechanics and anatomy, lung extracts were prepared from amphibians, reptiles, birds, and mammals. Lung extracts from mammalian lungs with true alveolar structure show typical surface tension-surface area characteristics, whereas other vertebrate lung extracts behave similarly to most other biological fluids. An alveolar lining layer with surface behavior similar to mammalian lung extracts would be expected to contribute to alveolar stability. Submitted on June 28, 1961
Disappearance of plasma radioactivity after injection of H3- or I131-labeled arginine vasopressin
Authors: Silver Lawrence , Schwartz Irving L. , Fong Conrad T. O. , Debons Albert F. , Dahl Lewis K. 
Published: December 2017

Tritiated and iodinated arginine vasopressin (AVP) were administered intravenously to human beings and to dogs. The level of plasma radioactivity was measured with time and showed a single exponential function in all cases, except with I113 vasopressin in human beings, where two exponential components were evident. In the dog, the half-time for the disappearance of radioactivity from plasma ranged from 3.5 to 7 min after administration of I113 AVP and from 4 to 5 min after H3 AVP. In similar experiments in man, I113 AVP gave a fast component with a half-time ranging from 0.3 to 2 min and a slow component with a half-time ranging from 1.6 to 6.5 min, whereas H3 AVP gave a single component with a half-time ranging from 2.3 to 5.5 min. The similarity in the disappearance curve of antidiuretic activity and the disappearance curve of radioactivity suggests that the latter reflects the rate of degradation of the biologically active hormone. Therefore, these labeled hormones appear to be useful tools for evaluation of vasopressin turnover in physiological and clinical conditions alleged to be associated with increased levels of circulating antidiuretic hormone or with abnormal rates of vasopressin production, release, or inactivation. Submitted on March 9, 1961
Importance of diffusion and chemical reaction rates in O2 uptake in the lung
Authors: Staub N. C. , Bishop J. M. , Forster R. E. 
Published: December 2017

The Bohr integration procedure for the approximate solution of the blood O2 tension along the pulmonary capillary from known values of alveolar, mixed venous, and end capillary O2 tensions and the O2 hemoglobin dissociation curve assumes, among other things, that the dissolved O2 in the blood is always in equilibrium with the hemoglobin, in other words that the exchange of O2 between the red cells and the plasma is instantaneous. Previous work (J. Appl. Physiol. 16: 511, 1961) has shown that, on the contrary, the experimentally measured rates of O2 uptake of the red cells are slow enough to limit the uptake of this gas in the alveolar capillaries. Therefore we have developed a method analogous to the Bohr integration for obtaining an approximate solution for the O2 tension of the plasma and of the red cells along the pulmonary capillary where Dl is a function of O2Hb saturation. Examples are given for a normal individual and an individual with severe anemia both breathing air and 14% O2. Submitted on July 18, 1961
Influence of pressure suit inflation on pulmonary diffusing capacity in man
Authors: Ross Joseph C. , Ley Glen D. , Coburn Ronald F. , Eller J. L. , Forster Robert E. 
Published: December 2017

Previous investigations of the effect of inflation of a pressure suit on pulmonary diffusing capacity (DL) have been reported from our two laboratories, one (Indianapolis) finding an increase and the other (Philadelphia) finding no change. The present investigation was carried out in Philadelphia, using some of the same subjects and pressure suits in order to reconcile the contradictory results. The earlier contradictory results were confirmed. The pressure suit used in the investigations at Philadelphia ( suit P)covered the entire body below the nipples, whereas the suit used in the investigations at Indianapolis( suit I) extended cephalad only as far as the costal margin. When suit P was inflated in the present study, DL again did not increase significantly in two subjects. However, when the upper part of the suit was folded down so that the thoracic cage was not covered, inflation of the suit did produce a significant increase in DL. Inflation of suit P when it covered the chest made it difficult for a subject not to perform a Valsalva maneuver during breath holding and caused more decrease in alveolar volume (Va) than when it was inflated in the folded-down position. In two subjects studied, we found no difference in air trapping with inflation of suit P in the two positions. The discrepancy between the results of the two earlier studies appears to have resulted from the different construction of the two pressure suits used. We conclude that pressure suit inflation in man will produce an increase in DL, presumably by means of pulmonary congestion. Submitted on September 22, 1961
A principle for counting tissue structures on random sections
Authors: Weibel Ewald R. , Gomez Domingo M. 
Published: December 2017

A new principle is derived from mathematical considerations which will allow the calculation of the number of bodies contained in the unit volume by counting the number of transections on the unit area of a random section. The simple equation involves two coefficients related to the volumetric density of the bodies in the volume, and to their configuration. Means for the accurate determination of these coefficients are given. The verification of this principle in model experiments showed a high degree of reliability of the method with average errors of estimate of 2–4%. The method has been applied to the counting of alveoli in five normal human lungs, which were found to number an average of 300 million, with a striking constancy from lung to lung. Submitted on May 31, 1961
Compensatory nystagmus conditioned during adaptation to living in a rotating room
Authors: Guedry Fred E. , Graybiel Ashton 
Published: December 2017

Seven men were rotated at 5.4 revs/min in a room for 64 hr. Controlled tests before and during this interval demonstrated that disorientation and nystagmus attributable to Coriolis acceleration effects diminished markedly. A compensatory nystagmus, induced by head or whole-body movements, was recorded more than 1 hr after the rotation had ceased. Factors of possible significance in conditioning the compensatory nystagmus are: 1) otolith and proprioceptor sensory influx prior to and during discordant canal input: 2) a consistent sensory influx for each stimulus-producing movement: 3) intention in stimulus-producing movements: 4) visual inhibition. Contributions of compensatory and arousal factors to vestibular suppression are considered in relation to practical problems of transfer of habituation from one acceleration environment to another. Submitted on December 1, 1961
Effect of oxytocin on myoepithelium of the breast
Authors: Wiederman Joseph , Stone Martin L. 
Published: December 2017

A laboratory study was made of the response of the myoepithelium of the postpartum human breast to synthetic oxytocin, comparing the effects of intranasal and intravenous administration. A clinical study was also undertaken to assess the effects of intranasal oxytocin on breast engorgement. Intramammary pressure was obtained directly through a polyethylene catheter placed in the mammary duct and connected to a pressure transducer and Poly-Viso recorder. A myoepithelial response was elicited by a threshold dose of 2 mU of oxytocin intravenously. Intranasal spray produced responses similar in amplitude to intravenous doses when applied in amounts 200 times the intravenous dose. The response pattern of intranasal spray was that of a series of contractions, whereas intravenous doses produced single contractions. The lag time from administration to response was 100 sec with intranasal oxytocin vs. 20 sec with intravenous doses. Clinically, a twice-a-day application of intranasal spray oxytocin appeared to accelerate the normal physiologic process of involution in nonnursing mothers. Submitted on November 22, 1961
Radiant temperature of the zenith at altitude
Authors: Hammel H. T. , Hardy J. D. 
Published: December 2017

Using a thermistor radiometer, measurements have been made of the radiant temperature of the zenith sky from ground level to 40,000 ft. The lowest temperatures measured were near -135 C, with an air temperature near -50 C at 36,000 ft. There was a high variability in sky temperature at altitude not observed at ground level. Although the low sky temperature as compared with air temperature points to the large thermal load imposed by radiant heat loss on man exposed to a high-altitude thermal environment, computation indicates this would amount to only about 77 Kcal/m2/hr for the completely clothed pilot. Submitted on October 26, 1961
Diffusing capacity and blood flow in different regions of the lung
Authors: Spicer W. S. , Johnson R. L. , Forster R. E. 
Published: December 2017

We have measured the disappearance of CO and, in most instances, acetylene relative to helium from early and late portions of the expired alveolar gas after 1.5–20 sec of breath holding at rest in four normal subjects and seven patients with obstructive emphysema and three with sarcoidosis. In all individuals, except one patient with emphysema, graphs of the logarithm of the relative expired alveolar CO concentrations in early and late expired samples against time of breath holding were parallel, but those for the late expired samples lay below these for the early expired samples. The equality of the slopes of the two curves indicated that net diffusing capacity/alveolar volume for those regions of the lungs contributing to the two samples is similar even in severe obstructive disease. The displacement of the disappearance curves can be explained by errors in estimation of the time the gas spends in the alveoli and by an increased rate of CO disappearance caused by reduced alveolar volume during expiration. Submitted on December 18, 1961
Respiratory dynamic resistance
Authors: Long Ernest Croft , Hull Wayland Elroy , Gebel Emile Louis 
Published: December 2017

Sinusoidal forcing at frequencies up to 17 cycles/sec was applied to the anesthetized, apneic dog by a body respirator. Forcing pressure and volume displacement were displayed in quadrature on an oscilloscope and planimetric integration of these loops indicated an increase in energy dissipated by total respiratory resistance per liter of air displaced, due to turbulence and changing airway geometry, with increasing frequency. Nonlinear resistance was calculated and the differential coefficient, dP/dV (dynamic resistance), was determined at 10° intervals throughout the respiratory cycle, at each of three frequencies in four dogs. Total respiratory resistance is a “nonohmic” dependent variable and changes progressively throughout the cycle. Submitted on October 20, 1961
Mechanism of bronchoconstriction during inhalation of dust
Authors: Widdicombe John G. , Kent Donald C. , Nadel Jay A. 
Published: December 2017

Inhalation of fine charcoal dust decreased airway conductance (increased resistance) in man. Subcutaneous injection of atropine blocked this effect. In paralyzed and artificially ventilated cats, inhalation of dust increased total pulmonary airflow resistance. This was prevented by blocking conduction in the cervical vagosympathetic nerves. Inhalation of dust stimulated activity in single afferent nerve fibers arising in the trachea and also increased activity in efferent parasympathetic nerve fibers going to the lungs. These results establish the reflex nature of bronchoconstriction during inhalation of dust and show its dependence on the cervical vagosympathetic nerves. Submitted on February 1, 1962
Additive effects of acetazolamide and fat emulsion on alveolar-arterial Pco2 difference
Authors: Cain Stephen M. 
Published: December 2017

Alveolar and arterial gas tensions were measured in anesthetized dogs during a control period, after intravenous injections of a carbonic anhydrase inhibitor, and after rapid intravenous infusion of fat emulsion. These were carried out in sequence. The alveolar-arterial (A-a) Pco2 difference increased from about 6 mm Hg during the control to 26 mm Hg after carbonic anhydrase inhibition. A further increase took place after fat emulsion when the A-a Pco2 difference averaged 35 mm Hg. There was no increase in the A-a Po2 difference between carbonic anhydrase inhibition and fat emulsion. The additive increase in the A-a Pco2 difference strongly suggested that fat emulsion did not further interfere with the interconversion of CO2 and bicarbonate. Submitted on February 8, 1962
Effects of chest compression on reflex ventilatory drive and pulmonary function
Authors: McIlroy Malcolm B. , Butler John , Finley Theodore N. 
Published: December 2017

External compression of the chest sufficient to reduce the lung volume (FRC) by 1 liter in eight normal subjects interfered with the mechanical function of the lungs. We have confirmed the findings of Caro et al. ( J. Clin. Invest. 39: 573, 1960), who showed a decrease in lung compliance and an increase in respiratory rate. Neither returned to normal when the compressing force was removed, and it was not until the subject took a deep breath that the lungs returned to their control state. We also found a reduction in anatomical dead space and alveolar hyperventilation. Arterial blood gas tensions showed evidence of complex ventilation-perfusion abnormalities, which could not be explained by any single factor. We think the hyperventilation associated with chest compression is reflex in origin and related to a decrease in lung volume rather than to any change in transpulmonary pressure. Submitted on January 4, 1962
Effects of chronic acceleration on induced nystagmus in the fowl
Authors: Winget Charles M. , Smith Arthur H. , Kelly C. F. 
Published: December 2017

Domestic fowl exposed to chronic acceleration (prolonged centrifugation) do not appear to “habituate” to repeated rotatory stimulation, as do similarly treated birds maintained at normal gravity. Chronically accelerated birds frequently exhibit postural or locomotor abnormalities, and such individuals lack a nystagmic response to rotatory stimulation. Submitted on August 21, 1961
DlCO measurements with gas chromatography
Authors: Smith Josef R. , Hamilton Lyle H. 
Published: December 2017

A gas chromatograph has been used to analyze gases for the measurement of pulmonary diffusing capacity using the breath-holding technique. The gas mixture used for the measurement consisted of carbon monoxide in air with neon as the insoluble inert gas. The calculated DlCO was unaffected when sulphur hexafloride (SF6) or He was substituted for Ne in the mixture, but since CO and Ne could be most simply and rapidly analyzed, this combination was preferred for the gas mixture used to measure DlCO. The mean DlCO for ten normal subjects was 25.8 ± 4.2 ml/min mm Hg. These results were comparable to values reported in the literature when established methods of analysis were used. An excellent correlation was found between calculated DlCO and the clinical condition of patients with impaired pulmonary diffusing capacity. Submitted on February 14, 1962
Effect of whole-body vertical vibration on respiration in human subjects
Authors: Duffner Lee R. , Hamilton Lyle H. , Schmitz Melvin A. 
Published: December 2017

The respiration of ten healthy male subjects was studied during 4-min exposures to vertical whole-body vibration of 0.15 and 0.35 g peak acceleration intensities of frequencies of 2 through 7 cycle/sec. Initial hyperventilation, with a subsequent return toward normal levels, occurred during the period of vibration. The breathing frequency decreased and the end-expiratory position dropped, but the vital capacity was not changed. Vibration-induced hyperventilation was most pronounced at 4–5 cycle/sec. Oxygen consumption was increased during vibration, with a maximum increase observed at the lowest frequencies. All changes were greater at 0.35 g than at 0.15 g acceleration. Except for a decreased alveolar CO2 concentration, respiration during the 4-min recovery period did not significantly differ from the previbration levels. Submitted on May 14, 1962
Quantitation of effects on mitochondrial swelling: some effects of ATP and aging
Authors: McGaughey Charles 
Published: December 2017

A method has been devised for the quantitative measurement of relative effects of substances or conditions on rate of change of mitochondrial volume. It can be used to study the effects progressively as the mitochondria swell. By this means, the effects of adenosine triphosphate (ATP) and aging on mitochondrial swelling were investigated. It was found that at constant mitochondrial volume, the rate of change of volume is a logarithmic function of aging time. The swelling of fresh mitochondria was mildly inhibited by ATP at very low volumes. Aging of rat liver mitochondria caused this inhibitory effect to be replaced by enhancement of swelling, which became greater in magnitude and was retained through larger volumes as aging time increased. The swelling enhancement was followed by inhibition, the magnitude of which increased with further swelling. The inhibitory effect of ATP on swelling of mouse liver mitochondria underwent a sudden marked increase at a particular mitochondrial volume independent of aging time and time of ATP exposure. At lower volumes the effect of ATP increased with aging time and swelling rate, whereas at larger volumes this relation ceased to be apparent. The possible significance of these results is discussed. Submitted on January 22, 1962
Thermodilution studies of ventricular volume changes due to isoproterenol and bleeding
Authors: Bristow J. David , Ferguson Richard E. , Mintz Fredric , Rapaport Elliot 
Published: December 2017

The effects of intravenous isoproterenol on left ventricular stroke and on end-systolic and end-diastolic volumes were studied in anesthetized dogs before and after bleeding. Volumes were measured by a thermodilution technique. In this indicator-dilution method a small amount of cooled blood is rapidly injected into the ventricle, and the washout of cold from the ventricle is sensed by a thermistor catheter at the root of the aorta. Control values showed that approximately two-thirds of the end-diastolic volume remained in the ventricle at the end of systole. Bleeding decreased all three volumes. Isoproterenol consistently increased ventricular emptying, as shown by the fall in the proportion of the end-diastolic volume which remained at end systole. This effect did not depend on an increase or decrease in the end-diastolic volume itself. End-systolic force-circumference relationships were derived from a consideration of idealized ventricular dimensions. A linear relationship between these calculated values was not altered by isoproterenol. Submitted on July 5, 1962
Influence of metabolism on uptake of CO and O2 by hemoglobin in erythrocytes
Authors: Sirs John A. 
Published: December 2017

The initial rate of oxygen uptake by hemoglobin in sheep erythrocytes, measured within 3 hr of blood collection, was found to be considerably higher than values previously observed. No similar effect was observed with carbon monoxide unless oxygen was also present. A decay curve of the initial rate with time, obtained on human erythrocytes, indicates that the cells reach a passive level within 2 hr in the absence of oxygen. The process is inhibited by NaF and no advantage was obtained on suspending the cells in their own plasma, rather than Ringer-Locke solution. An analysis of the results suggests that the membrane is increased by cell metabolism. Submitted on September 21, 1961
Physiological effects of continuous or intermittent work in the heat
Authors: Lind A. R. 
Published: December 2017

To define thermal limits for everyday work, a possible criterion which has been put forward described the climates (“prescriptive” climates) in which the level of bodily thermoregulation remained steady for a given rate of work. The present experiments were intended to determine the effect on results, obtained from brief exposures involving continuous work, of extending the exposure to a period of 8 hr and of presenting a given total energy expenditure (2,100 kcal) in different patterns of work and rest. During 8-hr exposures to three climates with dry and wet bulb temperatures of 29.4 and 23.9, 36.7 and 25.6, and 41.1 and 28.3 C, respectively, two subjects expended approximately 2,100 kcal in both 1) a nearly continuous level of activity and 2) intermittent bouts of much harder work interspaced by longer periods of rest. Evaluation and comparison of the results show that extension of exposures to periods of up to 8 hr per se did not demonstrably change the levels of rectal temperature, pulse rate, or weight loss found by the 2nd hr of exposure in the climates examined. Further, in prescriptive climates (in which the level of thermoregulation depends on the rate of work rather than on the environment), when the energy expenditure was 2,100 kcal in 8 hr, either continuously at a moderate rate, or intermittently at a high rate with compensatory rest pauses, the physiological cost was similar, as judged by rectal temperature, pulse rate, and weight loss. Submitted on June 15, 1962
Environmental temperature and energy expenditures
Authors: Consolazio C. Frank , Matoush Le Roy O. , Nelson Richard A. , Torres Juan B. , Isaac Gerhard J. 
Published: December 2017

Metabolic rates were compared on seven young men performing three levels of physical activity at three environmental temperatures of 70, 85, and 100 F. This study indicates that as the environmental temperature increases there is also an increase in metabolic rate of men performing a fixed activity. It has been shown that there was a significantly higher metabolic rate for men working at 100 F than at 85 and 70 F. These increases averaged 11.4% for the rest period, 13.3% for the moderate activity, and 11.7% for the heavier activity. Body temperatures also were significantly higher at 100 F than at 85 and 70 F environments (P < .005). They averaged 99.6 F for the 100 F temperature, and 99.1 F for both the 85 and 70 F temperatures. The findings in this study indicate that the metabolic rate of a fixed physical activity is increased in the heat and that this increase is not due to acclimatization or training. Submitted on September 19, 1962
Energy cost of running
Authors: Margaria R. , Cerretelli P. , Aghemo P. , Sassi G. 
Published: December 2017

Indirect calorimetric measurements were made on two athletes running at different speeds up to 22 km/hr at grades from -20 to +15%; the function was found to be linearly related to speed. Within these limits, the net kilocalories per kilogram per kilometer values seem to be independent of speed and related only to the incline. These values are about 5–7% lower than those found in nonathletic subjects, which shows that training in atheletes does not lead to great improvement. A nomogram is given for easily calculating the energy expenditure in running when the speed and the incline are known. The energy cost per kilometer in horizontal run (1 kcal/kg) is about double that for walking at the most economical speed (4 km/ hr). Submitted on July 31, 1962