bluuebunny/crossref_metadata_2025 huggingface dataset:
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
Temperature regulation of Eskimos, Indians, and Caucasians in a bath calorimeter
Authors: Milan Frederick A. , Hannon John P. , Evonuk Eugene
Published: December 2017

Eighteen men: six Alaskan Eskimos, six Arctic Athapascan Indians, and six Caucasian U. S. soldiers were immersed serially in a bath calorimeter where the rates of heat production and loss were measured during whole-body exposure to water temperatures of 35, 33, and 30.5 C. At each of these temperatures the Eskimos exhibited the highest rates of heat production and loss, followed by the Indians and Caucasians in decreasing order. Duplicate basal metabolic rate measurements averaged 46 kcal/hr m2 in the Eskimos, 42.5 kcal/hr m2 in the Indians, and about 37 kcal/hr m2 in the Caucasians. Body fat percentages calculated by the skin-fold method were: Eskimos, 6.6%; Indians, 12.3%; and Caucasians, 15.6%. Calculations showed the Eskimos had the lowest tissue insulation followed, respectively, by the Indians and Caucasians. Calculations showed the lower insulation in the Eskimos was independent of their lack of body fat and probably reflected a greater peripheral blood flow. Since the rectal temperature decrements during immersion were the same in all three groups, it was concluded that the surface temperature gradients extended more deeply in the Eskimos than in the other two groups. Hence, they could be described as having smaller “cores” and larger “shells” than either the Indians or the Caucasians.

Submitted on August 27, 1962d
Absorption by an in vitro preparation of dog intestinal mucosa
Authors: Hakim Ali , Lester R. G. , Lifson N.
Published: December 2017

Sheets of dog small intestinal mucosa consisting of only epithelium and lamina propria were mounted for in vitro study. The following transport behavior characteristic of the intestine was found: a) dependence of water transport from isotonic Ringer's fluid on the presence of glucose in the medium, b) water absorption against an osmotic activity difference, c) sensitivity of water transport to small excess hydrostatic pressure on the serosal side, d) uphill glucose movement, and e) chloride impoverishment.

Submitted on October 24, 1962
Direct measurement of respiratory pleural pressure changes in normal man
Authors: Daly Walter J. , Bondurant Stuart
Published: December 2017

Using a specially designed needle system, pressures were recorded directly from the pleural space in seated normal men. Respiratory pressure changes (ΔP) measured simultaneously from different pleural sites and the esophagus are not the same but become so after a large pneumothorax is produced. Since esophageal ΔP is little affected by a pneumothorax of 2–300 ml, it is suggested that, in the absence of pneumothorax, esophageal ΔP represents a better measure of the over-all elastic behavior of the lung than any local pleural ΔP. In the absence of pneumothorax, ΔP is less in the upper than in the lower chest. This may be an expression of a gradient either of distribution of ventilation or of elastic forces opposing expansion of the lung. In three of four subjects, end expiratory pressure was more positive in the low chest than in the high chest. Acute central vascular engorgement (pressure suit inflation) caused similar changes in esophageal and intrapleural ΔP. These observations confirm the previously observed decrease in lung compliance during acute central vascular engorgement and provide evidence of local differences in respiratory pleural pressure change in man.

Submitted on August 20, 1962
Changes in compliance in rabbits subjected to acute bronchoconstriction
Authors: Anthonisen Nicholas R.
Published: December 2017

The pulmonary mechanics of anesthetized rabbits were studied during induced acute bronchoconstriction. The bronchoconstricting agent was acetyl-β-methylcholine which, when injected intravenously as in these experiments, appeared to act via the pulmonary circulation. In spontaneously breathing animals functional residual capacity increased with bronchospasm, and dynamic compliance decreased. This decrease correlated in magnitude with the severity of the bronchoconstriction. Frequency changed in random direction. Dynamic compliance recovered more slowly than conductance after bronchoconstriction unless the lungs were inflated just prior to each recovery measurement, in which case the two variables recovered equally quickly. This observation suggested that airway occlusion accounted for part of the decrease in dynamic compliance. Bronchoconstriction reduced semistatic compliance in paralyzed artificially ventilated animals and also static compliance, which was measured by arresting breathing with phrenic stimulation, in spontaneously breathing animals. These observations supported the above hypothesis.

Submitted on September 26, 1962
Mechanism and pharmacology of endotoxin shock in sheep
Authors: Halmagyi D. F. J. , Starzecki B. , Horner G. J.
Published: December 2017

The cardiopulmonary consequences of coli-lipopolysaccharide and staphylococcus toxin administration were studied in sheep. Circulatory changes consisted mainly of a marked rise in pulmonary arterial and pulmonary arterial wedge pressure (with left atrial pressure unchanged), and a fall in cardiac output and in systemic arterial pressure. Fall in the latter closely followed the onset of pulmonary hypertension. The respiratory response consisted mainly of a severe fall in lung compliance produced by terminal airway closure. Continued perfusion of the nonventilated alveoli resulted in venous admixture. Premedication with antihistaminic, antiserotonin, or adrenolytic agents failed to affect the response. Norepinephrine or hypertensin administered after toxin injection had virtually no effect while isoproterenol treatment reduced pulmonary arterial pressure, increased cardiac output, arterial oxygen saturation, and, in cases of endotoxin shock, promptly raised systemic arterial pressure. Endotoxin-resistant sheep proved nonresponsive to minor pulmonary embolism and to incompatible blood transfusion. It is suggested that a common mediator agent is responsible for the similar cardiopulmonary consequences of these three diverse conditions.

Submitted on November 26, 1962
Metabolic response to cold air in men and women in relation to total body fat content
Authors: Buskirk Elsworth R. , Thompson Ronald H. , Whedon G. Donald
Published: December 2017

Eight healthy young men (ages 19–35), four older men (ages 38–42), three obese subjects (two women and one man, ages 20–34) were individually exposed on one or more occasions to 10 C (50 F) air in the Metabolic Chamber for periods of 2–4 hr. A minimal amount of clothing was worn: the males wore shorts and the females wore halters and shorts. Air movement was routinely less than 50 ft/min and relative humidity 50% or less. Body fatness among the subjects ranged from 13 to 45% of body weight. The metabolic response to cold determined from Vo2 and Vco2 was significantly and inversely related to per cent body fat according to the regression equation: kcal/(m2·hr) = 65.2 – 0.520 (% fat) ± 0.115. Total body insulation after 2 hr of exposure was significantly and directly related to per cent body fat and inversely related to the metabolic response. Despite these significant relationships, wide individual differences were observed in the metabolic response to cold between pairs of subjects of like age, previous history of cold exposure, and body fatness.

Submitted on September 27, 1962
Bronchial pressures and dimensions in health and obstructive airway disease
Authors: Macklem Peter T. , Fraser R. G. , Bates D. V.
Published: December 2017

Bronchial pressure, esophageal pressure, and flow at the mouth were measured during cinebronchography in three normal subjects, three patients with emphysema, and one subject with intermittent bronchospasm. Each cineframe exposure generated an electrical signal which was recorded simultaneously with pressures and flow. Since the bronchial catheter had a 1-cm radio-opaque tip, bronchial diameters were obtained simultaneously with bronchial pressure, esophageal pressure, and flow. By this technique the pressure drop down the bronchial tree during forced expiration was measured. In normals, although greater than 50% of the total pressure was required to produce flow from the right lower lobe bronchus to the mouth, the pressure drop down its length alone was only 2–15% of the total, whereas in emphysema it was 35–85% and was associated with collapse of this bronchus. The narrowing of large bronchi, in particular those with posterior membranous sheaths, is thus a factor in limiting expiratory flow in normal subjects. In the three patients with emphysema the collapsing right lower lobe bronchus impeded emptying of the lower lobe during forced expiration, apparently due to an increase in the compliance of this bronchus.

Submitted on November 15, 1962
Variability of magnitude of the Bohr effect in human fetal blood
Authors: Kirschbaum Thomas H.
Published: December 2017

A series of in vitro determinations, conducted on human fetal blood obtained at the time of delivery, of percentage oxyhemoglobin saturation, partial pressure of oxygen, and pH have made possible the evaluation of the magnitude of the Bohr effect in that substance. Analysis shows that the Bohr effect, defined as Δ log pO2/ΔpH, is a variable function of percentage oxyhemoglobin saturation over the statistically significant range in this study, from 10 to 87% saturation. The implications of this variability in terms of the molecular alterations of hemoglobin in the course of progressive oxygenation and in particular regard to the manifest heterogenicity of heme with respect to oxygen-acid radical interactions are discussed.

Submitted on August 13, 1962
Thermal indicator sampling and injection sites for cardiac output
Authors: Mohammed Shakil , Imig Charles J. , Greenfield Elisha J. , Eckstein John W.
Published: December 2017

The effects of indicator sampling and injection sites on estimation of cardiac output by the thermal dilution method were investigated in dogs. Dilution curves were recorded simultaneously with thermistors in the aortic arch and carotid or femoral artery after injection of indicator into the right atrium. The outputs calculated from carotid and femoral curves were higher than those from aortic curves. Nevertheless, the carotid and femoral arteries were considered satisfactory sampling sites because it was possible to predict aortic values from peripheral curves with a small range of error. The effect of indicator injection sites was studied by comparing outputs calculated from aortic curves after alternate injections into the right atrium and external jugular vein. The outputs calculated after jugular injections were higher. The external jugular vein was considered to be a less desirable injection site because the correlation between aortic values obtained after injections into the two sites was relatively low, and the predictability of one value from the other was not good.

Submitted on January 14, 1963
Relation of local skin temperature and local sweating to cutaneous blood flow
Authors: Senay Leo C. , Prokop Leon D. , Cronau Leslie , Hertzman Alrick B.
Published: December 2017

The relationship of local skin temperature and the onset of sweating to the local cutaneous blood flow was studied in the forearm and calf. The purpose of the investigation was to appraise the possible relation of sweat gland activity to the cutaneous vasodilatation which has been attributed to bradykinin or to intracranial temperatures. The onset of sweating was not marked by any apparently related increases in the rate of cutaneous blood flow. On the contrary, the onset of sweating was followed often by a stabilization or even a decrease in the level of cutaneous blood flow. The relations of the latter to the local skin temperature were complex, particularly in the forearm. There appeared to be additional unidentified influences, possibly vasomotor, operating on the skin vessels during transitional phases in the relation of skin temperature to blood flow.

Submitted on October 15, 1962
Relationship of increased breath-holding diffusing capacity to ventilation in exercise
Authors: Ross Joseph C. , Reinhart Ronald W. , Boxell John F. , King Leroy H.
Published: December 2017

Pulmonary diffusing capacity (Dl), as measured by all techniques, increases with exercise possibly due to an increase in the volume of blood in pulmonary capillaries (Vc), but the mechanism for the latter is not known. Previous studies have indicated that the steady-state Dl can be increased by hyperventilation alone, enough possibly to account for the increase in Dl as measured by this method with exercise. On the other hand, breath-holding Dl is not increased by voluntary hyperventilation preceding the measurement. The present study was carried out to determine whether or not the increase in ventilation rate is a necessary part of a combination of factors which account for the rise in Dl during exercise. In this study breath-holding Dl was measured in five subjects. All of the five subjects studied had an increase in Dl during exercise when ventilation was voluntarily restrained to the resting level, and the mean increase was as great as the mean increase during the same amount of exercise with normal unrestricted breathing. The increase in Dl when breathing was restricted during exercise could not be accounted for by differences in alveolar volumes or by differences in alveolar O2 and CO2 tensions in the two situations. This study demonstrates that increase in ventilation preceding the measurement is not a determinant of the increase in breath-holding Dl with exercise

Submitted on January 7, 1963
Oxygen cost of treadmill walking
Authors: Workman J. M. , Armstrong B. W.
Published: December 2017

The development is described of an equation to predict the energy cost of treadmill walking of adult males. Oxygen consumption during level walking is considered as the product: oxygen consumption per step · number of steps per minute. At any given speed within the domain of the variable, number of steps per minute is then found to be a reciprocal function of height, and oxygen consumption per step a function of body weight. Rearrangement of the mathematical expressions that describe these relationships permits the calculation of oxygen consumption of level walking as the product of two constants, Pw, a constant for the individual; and Ks, a constant for the speed. It is suggested that these constants may have other uses besides the prediction of oxygen consumption of level walking. Oxygen consumption of grade walking is considered as the excess of oxygen consumption over that observed walking on the level at the same speed. This should be, but apparently is not, simply related to body weight. In a test of its predicting power, the equation predicted the oxygen consumption of 84 treadmill walks of 44 subjects, with a correlation coefficient measured: predicted values, γ = + 0.935.

Submitted on October 26, 1962
A new renal artery clamp and applicator
Authors: Mulieri Louis A. , Korol Bernard
Published: December 2017

A modification in the design of the Goldblatt renal artery clamp and a description of a new single unit applicator-adjuster are presented. Detailed construction diagrams as well as a description of operative technique are given. The new clamp and applicator were used extensively in preparing a colony of renal hypertensive dogs in our laboratories. The results were excellent and the operative time and difficulties were reduced.

Submitted on February 14, 1963
Continuous recording of arteriolar dimensions with a television microscope
Authors: Wiederhielm Curt A.
Published: December 2017

A system which permits continuous recording of dimensions of microscopic blood vessels is described. The system utilizes information contained in the video signal of a television microscope to develop an analog voltage proportional to the time required for the electron beam to sweep across the image of the blood vessel. This time interval is also proportional to the dimension of the vessel. Calibration of the system yielded a standard error of estimate of ±3.7 μ on a series of glass capillaries, ranging in size from 15 to 150 μ. The rise time of the system was in the order of 40 msec. Long- and short-term drift was less than 3 μ/hr. The system is used in an experimental study of viscoelastic properties of small arteries and arterioles.

microcirculation; viscoelastic properties; frog mesentery

Submitted on April 17, 1963
Ventilatory capacity during prolonged exposure to simulated altitude without hypoxia
Authors: Ulvedal F. , Morgan T. E. , Cutler R. G. , Welch B. E.
Published: December 2017

Studies have been conducted in a sealed environment altitude chamber to study the chronic effect of reduced barometric pressure without reduced oxygen tension on human respiratory function and other physiological processes. Experiments were conducted at ground level, at 18,000 ft equivalent altitude (pO2 150 mm Hg), at 27,000 ft equivalent altitude (pO2 243 mm Hg), and at 33,500 ft equivalent altitude (pO2 174 mm Hg). Results were as follows: 1) Tests of pulmonary functions which are dependent on high volume flow rates are increased at altitude. These tests include maximum breathing capacity (increased 37% at 33,500 ft) and per cent of forced vital capacity during the first second of effort. 2) Expiratory minute volume was unchanged at altitude when oxygen partial pressure was maintained. 3) Forced vital capacity was reduced 3.1% at 18,000 ft, 2.9% at 27,000 ft, and 7.6% at 33,500 ft. This result was not due to hypoxia or abdominal distention and confirms the earlier findings of Rahn and Hammond. The cause of this change remains obscure but may be related to decreased lung volume. 4) The magnitude of changes observed appears to be somewhat proportional to altitude. Evidence is presented to relate increases in the flow-dependent tests to reduced density and reduced turbulent flow in the respiratory passages.

respiratory physiology; sealed environment; spacecraft; atmosphere selection; space medicine

Submitted on October 22, 1963
Lactate, pyruvate, glucose, and free fatty acid in mixed venous and arterial blood
Authors: Harris P. , Bailey T. , Bateman M. , Fitzgerald M. G. , Gloster J. , Harris E. A. , Donald K. W.
Published: December 2017

The concentrations of lactic acid, pyruvic acid, glucose, and free fatty acids have been measured simultaneously in the blood from the pulmonary and brachial arteries at rest and during exercise in a group of patients with acquired heart disease. The arteriovenous differences in the concentration of lactate, pyruvate, and free fatty acid were such as could be attributed to chance. The average concentration of glucose was slightly but significantly higher in the brachial arterial blood than in the mixed venous blood.

cardiac output; lung metabolism; exercise

Submitted on January 15, 1963
Body composition and serum electrolyte concentrations
Authors: Boling E. A. , Lipkind J. B.
Published: December 2017

Total exchangeable potassium, total exchangeable sodium, and total body water were simultaneously measured by dilution of K42, Na24, and H3, respectively. Total exchangeable chloride was estimated at the same time by dilution of Br82. The concentrations of water, sodium, potassium, and chloride were measured in the serum. The subjects included three healthy young men. The remaining 65 subjects were patients, with illness associated with disorders of nutrition and of water and electrolyte metabolism ranging from cachexia to extreme obesity and from dehydration to massive anasarca. The results show that in this highly varied group of subjects, neither Nae, Ke, nor Cle was correlated at all well with total body water when considered singly. Cle, in fact, was not considered to add useful information in the absence of information regarding other anions. However, the sum of Nae and Ke correlated exceedingly well with total body water (r = .991). Additional relationships containing serum cation concentrations had even higher degrees of correlation. Furthermore, it was found that expressions capable of predicting Nae or Ke could be derived from the data. Similarly high degrees of correlation were found when these regressions were computed for data from the literature.

Note:

With the Technical Assistance of E. Rossmeisl, R. McLean, H. Alpert, M. Halpin, and R. Gardner

total body water; total exchangeable potassium; total exchangeable sodium; total exchangeable chloride

Submitted on January 24, 1963
Functional evaluation of isolated perfused rat kidney
Authors: Bauman Arthur W. , Clarkson Thomas W. , Miles Ellen M.
Published: December 2017

A technique for perfusing the isolated rat kidney with heparinized whole blood is described. Numerous aspects of renal function are evaluated. Blood and urine flows approximated normal limits occasionally but diminished and increased, respectively, with time. The reabsorption rates of osmoles, sodium, chloride, potassium, lactate, and phosphate were proportional to the filtered loads. Variations in filtered load were due mainly to changes in glomerular filtration rate (GFR). Tubular secretion of p-amino hippuric acid varied with the GFR, and TmPAH per milliliter GFR was 60% of in vivo values. Glucose reabsorption was practically complete. Urine osmolalities, initially in the range 400–1,000 mosmoles/liter, fell during a perfusion, often to values well below plasma levels. Postperfusion histologic studies usually showed slight to moderate tubular dilatation. It was concluded that: 1) The handling of individual ions approximated in vivo function. 2) Changes in GFR and in the rate of excretion of PAH represented changes in the number of active nephrons. 3) Low urine osmolalities were due to decreasing ability of the nephrons to reabsorb water.

blood and urine flow; electrolyte excretion

Submitted on February 25, 1963
Response of normal subjects to prolonged high fluid intake
Authors: Habener Joel F. , Dashe Alfred M. , Solomon David H.
Published: December 2017

In order to test the hypothesis that the great variability seen in the serum osmolality characteristic of different normal persons is a result of fluid intake habits, four healthy male subjects ingested increasing amounts of fluid over a 4-week period reaching an average daily intake of approximately 8.5 liters during the 4th week. Serum osmolality measured repeatedly in the early morning and during weekly 6.5-hr water-deprivation tests did not vary significantly from that of control periods. It is concluded that in normal individuals fluid intake does not influence the “setting” of serum solute concentration.

serum osmolality homeostasis; serum solute concentration in water loading; water intoxication; renal concentrating capacity; fluid balance; water regulatory mechanisms

Submitted on June 25, 1963
A nomogram for predicting treadmill-walking oxygen consumption
Authors: Workman John M. , Armstrong Bruce W.
Published: December 2017

In the course of an analysis of the metabolic cost of treadmill walking, an equation was derived that predicts the walking oxygen consumption of adult males in terms of subject's height and weight, and of treadmill speed and grade. A nomogram has now been developed, based on this prediction equation, that may also be used to preset the treadmill to obtain a given exercise oxygen consumption.

exercise; metabolic rate; nomogram; treadmill walking

Submitted on May 20, 1963
Changes in alveolar and arterial gas tensions as related to altitude and age
Authors: Terman James W. , Newton Jerry L.
Published: December 2017

In the summer of 1962 at the White Mountain Research Station the early phases of altitude acclimatization were studied in six of the surviving eight members of the 1935 expedition to the Chilean Andes; they were from 58 to 71 years of age. Alveolar and arterial Po2 and Pco2 were determined for each man a few hours after arrival at 3,093 m and at 3,800 and 4,343 m over the next few days. The effects of age were superimposed on the classical responses to high altitude. The arterial and alveolar Pco2 values showed no significant gradient; the alveolar Pco2 was found to be lower for a given altitude than 27 years before. For example, their average alveolar Pco2 at 4,700 m in 1935 was 27.7 mm Hg as opposed to 25.1 mm Hg at 4,343 m in 1962. The case of Hall was exceptional: his alveolar Pco2 ranged from 21 to 24 mm Hg regardless of altitude for his sojourn of 22 days. In 1935 these six men had a mean A-a Po2 gradient of +3.0 mm Hg at 4,700 m, while in 1962 the gradient over the three altitudes was +12.4 mm Hg. These findings would likely be explained partially by age changes in the pulmonary ventilation-perfusion ratio.

acclimatization; pulmonary ventilation-perfusion ratio; alveolar-arterial Po2 and Pco2 gradients; alveolar hyperventilation; aging and altitude

Submitted on February 19, 1963
Topography of esophageal pressure as a function of posture in man
Authors: Milic-Emili J. , Mead J. , Turner J. M.
Published: December 2017

Esophageal and mouth pressures were determined at various fixed lung volumes in seven normal subjects in various postures. Esophageal pressure was obtained from balloons placed at various levels of the esophagus. The balloons contained a volume of gas small enough to render its effect on the pressure recorded negligible. In approximately the upper third of the esophagus changes in mouth pressure, head posture, and external pressure on the trachea produced pressure variations which were unrelated to variations in pleural pressure and were probably the result of traction on, or compression of, the esophagus by the trachea. These artifacts were absent in the lower two-thirds of the esophagus. In the lower third of the esophagus, pressures were found to vary markedly from point to point and with body posture. In approximately the middle third of the esophagus pressures were relatively uniform from point to point, did not vary markedly with body posture, and probably more closely reflect local pleural pressures. It is concluded that in studies of respiratory mechanics esophageal pressure should be measured in the middle third of the esophagus.

pleural pressure; lung volume-pressure curves; esophageal balloons

Submitted on August 13, 1963
Thrombin stimulation of platelet oxygen consumption rate
Authors: Hussain Qamar Zafar , Newcomb Thomas F.
Published: December 2017

Oxygen consumption of human platelets was measured by O2 cathode. Platelets were prepared by collecting blood into ACD solution, and isolation and washing in buffer by centrifugation. O2 consumption was measured by vibrating cathode at 25 C in Hank's solution. The Qo2 was 14.5 ± 4.8 mμmoles/min 109 platelets with added glucose and 21.4 ± 5.0 with added glycerol. Thrombin addition resulted in increase in Qo2 of elevenfold lasting 3–5 min followed by clumping of the platelets. EDTA blocked the thrombin effect. Similar effects were noted when prothrombin was activated to form thrombin. 5-Hydroxytryptamine was without effect. With EDTA the reaction had two phases, a phase of thrombin effect and a calcium-dependent clumping phase. The observations are compatible with the hypothesis that thrombin alters platelet permeability.

platelet clumping; viscous metamorphosis of platelets; platelet respiration measurement by O2 cathode; thrombin effect on platelet respiration; platelet respiration; platelet intermediary metabolism

Submitted on September 20, 1963
Cerebrospinal fluid in man native to high altitude
Authors: Severinghaus J. W. , B. A. Carceleń
Published: December 2017

CSF pH was shown in a prior report to remain essentially constant during 8 days of acclimatization to 3,800 m. In order to further evaluate the possible role of CSF acid-base equilibria in the regulation of respiration, 20 Peruvian Andean natives were studied at altitudes of 3,720–4,820 m. In ten subjects at 3,720 m, means were: CSF pH 7.327, Pco2 43, HCO3- 21.5, Na+ 136, K+ 2.6, Cl- 124, lactate 30 mg/100 ml. Arterial blood: pH 7.43, Pco2 32.5, HCO3- 21.3, Na+ 136, K+ 4.2, Cl- 107, hematocrit 49, SaOO2 89.6. In six subjects at 4,545 m and four at 4,820 m CSF values were not significantly different; mean arterial Pco2 was 32.6 and 32.3, respectively. The only significant variations with altitude were the expected lowering of PaOO2 to 47 and 43.5 mm Hg, and of SaOO2 to 84.2 and 80.7, and increase of hematocrit to 67% and 75%, respectively. The natives differed from recently acclimatized sea-level residents in showing less ventilation (higher Pco2) in response to the existing hypoxia, and less alkaline arterial blood. The difference appears to relate to peripheral chemoreceptor response to hypoxia rather than central medullary chemoreceptor.

respiratory regulation at high altitude; chronic acclimatization to altitude; peripheral chemoreceptor response to hypoxia; CSF and medullary respiratory chemoreceptors

Submitted on June 12, 1963
Surface activity of saline extracts from inflated and degassed normal lungs
Authors: Levine Bernard E. , Johnson Rudolph P.
Published: December 2017

Normal rabbit lungs have been extracted in aerated and in vitro degassed states to clarify the effect of atelectasis upon the surface activity of saline lung extracts. Three extraction techniques, chopping, mincing, and pestle-homogenization, were compared. All extraction methods give highly active extracts using aerated lung samples, but extracts from airless lungs prepared by chopping or mincing invariably showed higher minimum surface tensions, lower stability indices, and took more time to reach minimum tension than did extracts of the same lungs when aerated. Differences could be due to decreased area of saline-alveolar contact during extraction, as it was noted that increasing the weight of the lung sample or dividing the lung more finely (i.e., pestle homogenization) increased extract activity. If saline extracts of atelectatic lung are studied, qualitative statements about presence of surfactant should take into account weight of lung tissue and technique of extraction.

lung surface tension; atelectasis; pulmonary surfactant material; rabbit lung surface activity

Submitted on September 11, 1963
Use of an optical density ruler in measurements of dye-dilution curves
Authors: Bassingthwaighte James B. , Edwards Anthony W. T. , Wood Earl H.
Published: December 2017

The inapplicability of Beer's law to densitometry of dyes in whole blood or other nonhomogeneous media has been long known. When using a densitometer whose output is directly proportional to the light transmitted, a simple transformation— log X = log (x – x0)—can be employed to allow rapid, accurate estimation of dye concentration. This is facilitated by use of an optical density ruler. The transformation, X = x – x0, can be made mechanically, by shifting the infinity position of the ruler with reference to the zero light transmission position, or electrically, by appropriate use of zero suppression in the densitometer circuit. The transformation results in an exponential (logarithmic) relationship between light transmitted and concentration of the dye (indocyanine green). Readings of relative optical density obtained by use of the ruler are multiplied by a calibration constant to calculate dye concentration. The principles of the transformation have been applied to the determination of the optimal zero suppression required for maintenance of constant sensitivity of the densitometer in the presence of various levels of background dye.

densitometer calibration; indocyanine green densitometer; calibration of dye-dilution curves; correction of dye-dilution curves

Submitted on September 13, 1963
Effect of vasoconstriction on galvanic skin response amplitude
Authors: Edelberg Robert
Published: December 2017

Vascular mediation of the effect of cooling on galvanic skin response (GSR) amplitude was investigated by maintaining a finger site under isothermal conditions while inducing reflex vasoconstriction by cooling the rest of the hand in a water bath at 15 C. This procedure caused an initial increase in GSR amplitude, relative to that on the opposite (control) hand, followed by a steady decline to levels significantly lower than normal. Base resistance was generally unaffected. Smaller GSR waves frequently showed a paradoxical increase in size at the same time as larger ones were attenuated. In control runs in which the insulated chamber acted as a calorimeter the fall of temperature occasioned by arterial occlusion of the finger was of the same order as that produced by cooling. Arterial occlusion accompanying cooling did not change the temperature drop and it was concluded that a cooled blood supply could not account for the observed effects. Rather they appear to depend on cutaneous vasoconstriction. This conclusion implies an artificial relation between vasomotion and GSR as autonomic measures whenever pronounced vasoconstriction occurs.

effect of vasoconstriction on skin resistance; temperature effect on skin resistance; temperature effect on GSR; effect of blood supply on electrodermal measures; reflectance plethysmography

Submitted on July 22, 1963
In vitro respiration of normal and pathologic human lung
Authors: Strauss Bella
Published: December 2017

The Qo2 of normal and pathologic human pulmonary tissue was measured according to the direct method of Warburg. Lung specimens were reduced to rods of intact cells in their normal architectural relationships by the McIlwain chopper. This instrument is thought to eliminate the problem of erratic and incomplete diffusion of oxygen into the preparation by virtue of the fact that tissue can be subdivided into uniformly thin units, well within maximum allowable dimensions as determined by Warburg. Quantitation solely of actively respiring elements by the point-counting method of Chalkley permitted comparison of respiratory rate of normal with abnormal pulmonary tissue and eliminated the problem in calculation of Qo2 of dilution of pathologic material with normal cells and necrotic, nonrespiring elements. Oxygen consumption values for normal, tuberculous, and malignant lung were, respectively, 2.1, 5.4, and 8.6 μl O2/mg dry wt. per hr, suggesting that the oxidative metabolism in tuberculous inflammation and malignancy primary in the lung is elevated significantly. Possible sources of this augmented metabolic rate are discussed.

lung tissue metabolism; human pulmonary tissue respiration; tuberculous lung tissue metabolism; lung carcinoma tissue metabolism; lung tissue preparation

Submitted on September 19, 1963
Chronic intravenous cannulas for rats
Authors: Weeks James R. , Davis John D.
Published: December 2017

The intravascular portion was made of silicone rubber, passed down the external jugular vein into the right heart. The remainder was made of polyethylene, brought subcutaneously to the back of the neck. Most cannulas remained functional for many weeks.

silicone rubber cannulas

Submitted on October 3, 1963
Measurement of intraluminal pressure from external pressure with strain transducers
Authors: Okino Haruka
Published: December 2017

In an effort to find a means of recording absolute systemic arterial pressure from the skin surface, steady pressures in rubber-walled models were recorded with external pressure-sensing devices. The recorded pressure at which a plateau appeared was dependent on the degree of stretch in the wall of the pressure source. Distortion of the wall of the source by the pressure sensor resulted in a recorded curve with no plateau. The area of the sensor was critical; those with diameters greater than that of the source recorded only part of the internal pressure. When the diameter of the sensor was less than that of the source, a fairly linear relationship between recorded and source pressure could be obtained, but interposition of sponge rubber to simulate tissues lying between the artery and the body surface produced nonlinear responses. It was concluded that external sensors are adequate to record the waveforms of arterial pressure but cannot be reliably calibrated to provide accurate measurement of its level.

sensing device, arterial pressure; systemic pressure; measurement, external; internal pressures, measurement of; transcutaneous arterial pressures; arterial pressure sensing; external measurement of systemic pressures

Submitted on July 8, 1963
Body fluids and electrolytes after prolonged cardiopulmonary bypass
Authors: Brinsfield Dorothy , Hopf M. A. , Mayer S. E. , Galletti P. M.
Published: December 2017

Fluid and electrolyte balance was studied in 21 dogs after partial heart-lung bypass of 10 hr duration. Water retention was demonstrated by an increase in body weight and total body water, primarily due to an increase in extracellular fluid. Electrolyte retention was suggested by an increase in total extracellular sodium, potassium, and chloride. Urinary output was relatively normal but a progressive drop in urinary specific gravity was observed during bypass. Blood pH remained essentially unchanged. However, an increase in plasma lactate and a decrease in plasma bicarbonate suggested some degree of hypoxia and metabolic acidosis at the cellular level. Altered hormonal regulation of sodium and water excretion, hemolysis secondary to blood trauma, and the exchange of intracellular potassium for extracellular hydrogen ions were considered possible explanation for the fluid and electrolyte changes observed.

assisted circulation; heart-lung bypass; acid-base balance; fluid balance; extracorporeal circulation; electrolyte changes with partial bypass; membrane oxygenator; disc oxygenator; bubble oxygenator

Submitted on June 20, 1963
Effects of chlorothiazide on working capacity of normal subjects
Authors: Danzinger Rudolph G. , Cumming Gordon R.
Published: December 2017

In normal subjects chlorothiazide produced a 21% fall in plasma volume, a 15% decrease in physical working capacity, and an 11% decrease in maximum oxygen consumption. These changes were reversed by intravenous dextran. However, high intensity exercise was carried out despite the decrease in plasma volume.

plasma volume; maximum oxygen consumption

Submitted on October 18, 1963
Partitioning of respiratory flow resistance in man
Authors: Ferris B. G. , Mead J. , Opie L. H.
Published: December 2017

Measurements of flow resistance of various components of the respiratory system were measured in adult male subjects in the sitting position. Nasal resistance is the largest single component being nearly one-half the total and two-thirds of the airway resistance during nose breathing. It is highly nonlinear, and shows much variability. During mouth breathing upper airway resistance (mouth, pharynx, glottis, larynx and upper trachea) is also markedly nonlinear, and accounts for one-third the total airway resistance. Lower airway resistance is approximately linear up to flows of 2 liters/sec. Pulmonary tissue resistance is low as reported in this study. Chest wall resistance is nearly linear up to flow rates of 2 liters/sec and accounts for slightly less than half the total respiratory resistance during mouth breathing and 10–19% during nasal breathing.

larynx; airways; chest wall; nose

Submitted on December 16, 1963
Reproducibility of transient response to CO2 inhalation in man
Authors: Read D. J. C. , Maloney J. E. , Fowler K. T.
Published: December 2017

The transient changes in ventilation and alveolar PCO2 following the inhalation of 4% CO2 and the return to air have been studied in five normal subjects in an attempt to characterize the intact respiratory chemostat in man. In all 13 studies the changes of ventilation lagged behind those of alveolar PCO2, while the latter consistently over- or undershot its later steady-state value. The timing and magnitude of the responses were in general agreement with the predictions made by Grodins et al., who assumed in their model that the chemoreceptors respond to a single stimulus (PCO2) and are embedded in tissue in equilibrium with venous blood. In four duplicate experiments on individual subjects the quantitative reproducibility of the transients was poor, due largely to cyclic and random variations of ventilation shown by all subjects, even when in the steady state. This precluded any accurate search for differences introduced into the predicted transient response by the adoption of Defares' more sophisticated model, in which the influence of a changing cerebral blood flow on receptor PCO2 is considered. Studies performed during mild hypoxia revealed no change in transient response.

control of ventilation; steady-state ventilation; random changes in ventilation; cyclic changes in ventilation; effect of hypoxia on ventilation; respiratory chemoreceptor

Submitted on June 24, 1963
Alveolar capillary temperature compared with aortic and bronchial wedge temperatures
Authors: Edwards A. W. T.
Published: December 2017

Temperature for gas exchange in the alveolar capillaries was determined by the helium-argon method in nine dogs over a range of body temperatures from 37–42 C. The experiments were much more prolonged than those previously carried out in man. Results were compared with simultaneous measurements in the aortic arch, right ventricle, gastrointestinal tract, and bronchial tree. There was no significant difference between alveolar capillary temperatures and those in the right and left heart and bronchial wedge position, even when body temperature was changing. Deep rectal temperatures gave a reasonable estimate of alveolar temperature provided the body temperature was steady, but esophageal and gastric measurements were not reliable, the reading increasing as the stomach was approached. The results support the validity of the helium-argon method and indicate that accurate estimates of alveolar capillary temperature may be obtained by direct measurements in the central circulation or bronchial wedge position.

Note:

With the Technical Assistance of Judith Laurie

alveolar gas exchange; intravascular temperatures; inert gases; solubility of gases; esophageal temperature; gastric temperature

Submitted on December 16, 1963
Effect of low concentrations of ozone on pulmonary function in man
Authors: Young W. A. , Shaw D. B. , Bates D. V.
Published: December 2017

Eleven subjects in sixteen experiments breathed 0.6–0.8 ppm of ozone through a mouthpiece for 2-hr periods. Measurements of pulmonary function were made immediately before and after each experiment. The changes were compared with those observed after a control experiment in which air was breathed through the same circuit for a similar period. In this concentration, ozone was found to produce a highly significant reduction in steady-state D1CO of 5.4 ml CO/min mm Hg, a change about four times larger than that of the air control experiments. The vital capacity, FEV0.75 x 40, and maximal midexpiratory flow rate decreased by about 10% after ozone breathing, the change being statistically significant in the first two of these only. Gas distribution, and dynamic and static pulmonary compliance were measured in two subjects and were not affected by ozone. Thickening of the alveolar wall by edema fluid is suggested as the most likely explanation of the fall in D1CO that has been observed. The vital capacity and expiratory flow rates may be limited in part by tracheobronchial irritation that follows inhalation of 0.6 ppm of ozone for 2 hr.

diffusing capacity after breathing ozone; lungs, effect of ozone; pulmonary function after breathing ozone

Submitted on September 23, 1963
Physiological reactions to cold of Bushmen, Bantu, and Caucasian males
Authors: Wyndham C. H. , Morrison J. F. , Ward J. S. , Bredell G. A. G. , Von Rahden M. J. E. , Holdsworth L. D. , Wenzel H. G. , Munro A.
Published: December 2017

Two separate studies of the reactions to cold of one sample of 8 and one sample of 15 Kalahari Bushmen were made in their natural habitat and the results compared with the Bantu and, to a smaller extent, with the Caucasians. With a decrease in temperature from 27 to 5 C the metabolisms of all three groups rose. Metabolic rates per square meter of Bantu and Bushmen were similar, although higher than those of the Caucasians, but the percentage increases were closely similar for all groups. Rectal temperatures of Bushmen and Bantu were similar and decreased as the temperature dropped, while that of the Caucasians rose. Toe and finger temperatures of the Bushmen were higher over the whole temperature range than those of the Bantu and Caucasians, while the average skin temperatures were closely similar. Metabolic rates and rectal temperatures, therefore, indicate that subcutaneous tissue insulation against heat flow is greater for the Caucasians than for the Bantu or the Bushmen. Measurements of average skinfold thicknesses confirm this finding. Bushmen and Bantu reactions are quantitatively similar, but are qualitatively slightly different. From these findings we conclude that the difference between Bushmen, Bantu, and Caucasians is essentially morphological.

desert and "river" Bushmen in the heat; effect of morphology on reaction to heat; heat reactions of Bantu and Bushmen; state of acclimatization to heat of Bushmen and Bantu; sweat rates of Bantu and Bushmen in standard heat conditions

Submitted on October 21, 1963