bluuebunny/crossref_metadata_2025 huggingface dataset:
Relation of arterial pressure to spontaneous variations in digital volume
Authors: Burch G. E. , DePasquale N.
Published: December 2017

Simultaneous digital plethysmographic and brachial arterial pressure recordings in 11 normal subjects at rest in bed in a comfortable atmosphere showed that the spontaneous variations in digital volume (alpha and beta deflections) were independent of variations in arterial blood pressure. This indicates that the regulation of the caliber of the peripheral blood vessels as well as the spontaneous variations in the volume of the digital vessels is not passively produced by fluctuations in arterial blood pressure, including the Traube-Hering waves, but must be controlled by different centers and pathways of the sympathetic nervous system.

Submitted on July 27, 1959
Spontaneous variations in venous tone in man
Authors: Quiroz Antonio C. , Burch George E. , Malaret German E.
Published: December 2017

Using the intact isolated venous segment technique, Statham strain-gauge pressure transducers and a multichannel direct recorder, spontaneous changes in venous tone were recorded in human subjects with and without congestive heart failure. Evidence was presented to show the existence of spontaneous variations in venous tone. Specific venous pressure deflections were described similar to, if not identical with, the alpha and beta deflections described in digital plethysmography. Venous pressure deflections associated with respiration and with transmitted arterial pulsations were also described. The effect of Cheyne-Stokes respiration on systemic venous pressure was observed fortuitously in one subject. It was noted that during sleep venous pressure usually decreased but occasionally increased. This increase is probably associated with dreams or other disturbances. Spontaneous venomotor changes were found equally in subjects with and those without congestive heart failure.

Submitted on September 14, 1959
Tongue, hyoid and larynx displacement in swallow and phonation
Authors: Shelton Ralph L. , Bosma James F. , Sheets Boyd V.
Published: December 2017

Cinefluorographic observations of the pharyngeal portion of the tongue and of the hyoid and larynx of 10 persons were reported during the following physiological acts: deglutition while in upright and in supine positions, phonation of the sound m and phonation of the sound m in the falsetto voice. The patterns of displacement in deglutition were found to be consistent among and within subjects for the 10 subjects. Consistent patterns were not found in the phonation series, but various similarities of phonation and deglutition were noted. The conclusions were reached that performance of swallow may be used to evaluate motor performance in the pharyngeal region and that understanding of pharyngeal physiology requires a multistructural approach. The concept of a unified tongue-hyoid-larynx column was endorsed.

Submitted on November 9, 1959>
Effect of CO2 inhalation on arterial pressure, ECG and plasma catecholamines and 17-OH corticosteroids in normal man
Authors: Sechzer P. H. , Egbert L. D. , Linde H. W. , Cooper D. Y. , Dripps R. D. , Price H. L.
Published: December 2017

Twelve male volunteers inspired concentrations of carbon dioxide in oxygen ranging from 7% to 14% for periods of 10– 20 minutes. Respiratory minute volume, arterial pressure, heart rate, and plasma concentrations of epinephrine, norepinephrine and 17-OH corticosteroids were increased in every subject during hypercarbia. Abnormal cardiac rhythm was infrequently observed. Following substitution of oxygen for the carbon dioxide-oxygen mixture, the altered measurements returned to normal over a period of roughly 10 minutes. Neither marked hypotension nor cardiac arrhythmia was observed after correction of hypercarbia.

Submitted on January 8, 1960
Common carotid blood temperature
Authors: Rubenstein Edward , Meub Daniel W. , Eldridge Frederic
Published: December 2017

Common carotid artery blood temperature was measured by means of a needle thermistor in seven subjects under thiopental-nitrous oxide anesthesia. In each subject the blood temperature was within 0.2°C of the oral temperature. In the one subject so tested, the breathing of air chilled to 4°C had no effect on the common carotid blood temperature. In four out of five subjects the common carotid artery temperature was lowered (0.2°–0.5°C) by applying cold packs to the homolateral side of the anterior aspect of the face and forehead for 5–20 minutes. In the fifth subject there was no change. The probable mechanism of this cooling is heat exchange between the artery and the internal jugular vein which drains the chilled structures through the common facial vein. Rewarming the face and forehead had no significant effect on the common carotid blood temperature.

Submitted on July 8, 1959
Hand circulation in the cold of Lapps and North Norwegian fishermen
Authors: Krog J. , Folkow B. , Fox R. H. , Andersen K. Lange
Published: December 2017

The hand blood flows of Norwegian Lapps and North Norwegian fishermen were compared with those of a group of control subjects to determine whether habituation to cold alters the local vascular response. Blood flow was measured using venous occlusion plethysmographs with local temperatures of 40°, 20°, 10°C and a few degrees above zero. In further experiments using Dewar-flask calorimeters, the rate of heat elimination and rapidity of onset of the cold vasodilatation response on immersing the hand in water at 0°C were also recorded. The subjects were kept warm in order to remove as far as possible the effects of differing degrees of vasoconstrictor fiber activity. The onset of the cold vasodilatation was found to be more rapid in the cold-habituated subjects than in the control subjects. The levels of hand blood flow were, however, the same in all three groups of subjects, implying that habituation to cold does not alter the local vascular response to temperature. It is suggested that the difference reported by other workers in similar studies are probably found only when subjects examined are partially vasoconstricted, and reflect a more general process of adaptation to cold which results in a reduced vasoconstrictor fiber activity on exposure to a given thermal environment.

Submitted on August 19, 1959
Circulation of heat to the hands of Arctic Indians
Authors: Elsner Robert W. , Nelms John D. , Irving Laurence
Published: December 2017

Nine Indian men of an arctic village and eight urban white men have been compared in their responses to hand immersion in cold water. Following a 30-minute immersion in warm water (30°C) the hands were placed in cold water in an insulated bath (initially 5°C) for an additional 30 minutes. The rate of heat transfer to the water, finger skin temperatures and skin temperatures over a wrist vein were measured. All subjects were tested in this manner in two environmental situations: clothed in a warm room and unclothed in a cool room. In another experiment six Indians and five whites immersed their right hands in ice water while sitting confortably warm. Generally, the Indians showed a markedly superior ability to maintain hands warm in cold water. Their hands transferred more heat to the water whether the subjects were comfortably warm or chilly. In the cool environment hand heat loss was reduced in both groups, but the calculated heat transfer from circulation alone was still about twice as great in the Indians. The skin temperature measurements reflected the general trends of hand cooling and rewarming. The Indians withstood the hand immersion in ice water with quicker rewarming and less pain than the whites. Although their response is not conserving of metabolic heat, the loss is apparently trivial. The warming of the Indians' hands appears therefore to be adaptive in nature.

Submitted on November 12, 1959
Mechanism of action of insulin hypoglycemia on gastric secretion in man
Authors: Sun David C. H. , Shay Harry
Published: December 2017

The effect of insulin hypoglycemia on acid output of gastric secretion over 5-hour periods was studied in eighteen patients with duodenal ulcer, five patients before and after vagotomy and two patients before and after bilateral total adrenalectomy. Results of this study show three components of the mechanism of action of insulin hypoglycemia on gastric secretion, an initial inhibitory effect on basal gastric secretion, a stimulating effect mediated through the vagus nerve responsible for the early phase of secretion (1st and 2nd hr.) and. a gastric secretory response mediated through the adrenal glands manifested in the late phase of secretion (3rd–5th hr.). However, the magnitude of this late phase of gastric secretion was considerably less pronounced after vagotomy. It appears that a maximal response of this phase of gastric secretion following insulin hypoglycemia dependent on the adrenal gland is also dependent upon an intact vagal mechanism. A significant hypoglycemia of 40 mg % or less was necessary to produce the late phase of gastric secretion. The adrenal phase can contribute to the potential for ulcer occurrence or reactivation, not so much through the increase in secretion it alone might induce, since this is small, but of greater importance in its synergistic action with the vagal mechanism.

Submitted on December 9, 1959
External work in level and grade walking on a motor-driven treadmill
Authors: Snellen J. W.
Published: December 2017

When studying a walking subject's thermal exchange with the environment, it is essential to know whether in level walking any part of the total energy expenditure is converted into external mechanical work and whether in grade walking the amount of the external work is predictable from physical laws. For this purpose an experiment was set up in which a subject walked on a motor-driven treadmill in a climatic room. In each series of measurements a subject walked uphill for 3 hours and on the level for another hour. Metabolism was kept equal in both situations. Air and wall temperatures were adjusted to the observed weighted skin temperature in order to avoid any heat exchange by radiation and convection. Heat loss by evaporation was derived from the weight loss of the subject. All measurements were carried out in a state of thermal equilibrium. In grade walking there was a difference between heat production and heat loss by evaporation. This difference equaled the caloric equivalent of the product of body weight and gained height. In level walking the heat production equaled heat loss. Hence it was concluded that in level walking all the energy is converted into heat inside the body.

Submitted on April 26, 1960
Influence of state of inflation of the lung on pulmonary vascular resistance
Authors: Whittenberger James L. , McGregor Maurice , Berglund Erik , Borst Hans G.
Published: December 2017

The relationship between the degree of pulmonary inflation and the pulmonary vascular resistance was studied in an open-chested dog preparation. It was possible to control the state of inflation and the blood flow to the lung under study. Vascular resistance could then be observed under controlled conditions. In most cases the resistance at complete collapse was very slightly higher than at moderate levels of inflation. In a few instances collapse was associated with a more marked elevation of resistance. Higher levels of inflation resulted in elevation of vascular resistance. At high levels of pulmonary blood flow and pulmonary arterial pressure, the flow resistance curve is lower than at low levels of blood flow. The resistance values obtained during deflation of the lung were consistently different at equal transpulmonary pressures from those obtained during inflation. The possible reasons for this hysteresis are discussed. Evidence is presented that the increased resistance at high levels of lung inflation is due to the effect of transpulmonary pressure on the vessels surrounding the alveoli.

Submitted on January 11, 1960
Energy expenditure in level and grade walking
Authors: Bobbert A. C.
Published: December 2017

An empirical formula was developed from which mean values for energy expenditure per kilogram of body weight (Ew) can be calculated for groups of normal adult males, walking on a motor-driven treadmill with speeds in the range of 35–115 m/min. and gradients in the range of 0–12 degrees. The formula was derived from experiments with two subjects. From the results it appears that Ew increases with the square of speed both in level and grade walking and that log Ew increases linearly with the geometric angle (in degrees). The validity of the formula was tested by experiments with 4 other subjects and experimental data from the literature. A close agreement between actual and predicted values was found. Factors influencing individual values for Ew are discussed. A diagram is presented from which Ew may be read off for various combinations of gradient and speed.

Submitted on September 17, 1959
Effect of training on eosinophil response of exercised rats
Authors: Keeney Clifford E.
Published: December 2017

The eosinophil count of 10 rats decreased from a mean resting count of 435.5 cells/cu mm-233.2, 4 hours after swimming to exhaustion (mean swimming time 66.2 min.). After submaximal swimming (mean swimming time 33.1 min.) the mean eosinophil count was 275.3. Following a 6-week period of daily swimming the mean eosinophil count after exhaustive swimming was 114.4 cells/cu mm (mean swimming time 126.5 min.). After submaximal swimming (mean swimming time 63.2 min.) the mean eosinophil count was 143.6 cells/cu mm. Eight days after the termination of training the eosinophil response was measured after swimming bouts of the same duration as the pretraining periods (66.2 and 33.1 min.). The eosinophil counts were 261.2 and 270.0, respectively. Eosinophil counts immediately following training were statistically significantly lower than pretraining counts or counts made 8 days after termination of training. Counts after exhaustive swimming were significantly lower than after submaximal swimming. It was concluded that training increases the magnitude of the eosinophil response to exercise.

Submitted on November 13, 1959
Pulmonary function in different animals
Authors: Drorbaugh James E.
Published: December 2017

Relaxation pressure-volume curves have been determined from the lungs and thorax of mice, rats, rabbits and dogs. From these data figures are obtained for body weights, vital capacity and compliance. These are compared with similar data for man and calculated values for tidal volumes and frequency of breathing obtained from the literature. Calculations were made of the elastic work of breathing per breath and per minute. All values were plotted on double log paper against body weight so that they could be expressed as proportional to some power of body weight. It was found that compliance, tidal volume, vital capacity and elastic work per breath are all nearly proportional to the first power of the body weight while the elastic work per minute, like the rate of oxygen consumption, is proportional to the 0.7 (or 0.73) power of body weight. It is concluded that lungs of large and small animals tend to have the same compliance per unit of vital capacity and require the same pressure for the intake of one tidal volume. A large lung may therefore be regarded as equivalent to many smaller lungs in parallel.

Submitted on June 13, 1960
Diffusion of oxygen into a film of whole blood
Authors: Marx Thomas I. , Snyder Warren E. , St. John Andrew D. , Moeller Calvin E.
Published: December 2017

In the study of artificial blood oxygenation, the mechanism of oxygen diffusion and absorption in a blood film is of particular interest. An equation was derived for the diffusion of oxygen into whole blood films that are thick compared to the red cell size. The equation, which was solved on an electronic analogue computer, showed that simple expressions for an advancing interface of oxygenated blood are good approximations. An equation for a blood film bounded by a semipermeable membrane was also derived. An experiment was conducted to confirm the advancing interface theory. In a second experiment, the diffusivity of oxygen in whole blood was found to be approximately 1.3 (10–5) cm2/sec. When using highly permeable membranes, such as silicone rubber, in a blood oxygenator, the relative permeabilities of a blood film and the membrane are such that in many cases the resistance of the blood film is the controlling factor.

Submitted on October 5, 1959
In vivo effects of inositol phosphatide (lipositol) on serum lipids and atherosclerosis of hyperlipemic rabbits
Authors: Sachs Bernard A. , Danielson Ethel , Leiter Louis
Published: December 2017

The profound immediate mobilization of neutral fat and cholesterol reported following soybean lipositol fraction infusion in the normal rabbit could not be demonstrated in the rabbit made hypercholesterolemic by cholesterol feeding. A delayed mobilization of neutral fat was noted 24 hours after the infusion of lipositol in saline to hyperlipemic rabbits. Contrary to results reported by others, the phosphatide infusions had no effect on the development of atherosclerosis and did not result in the resorption of already developed atherosclerotic plaques in the rabbit.

Submitted on March 11, 1960
Effect of hypothyroidism on heat production and loss during acute exposure to cold
Authors: Fregly M. J. , Iampietro P. F. , Otis A. B.
Published: December 2017

Thyroidectomy (propylthiouracil treatment) and adrenalectomy increased the rate of cooling of rats restrained and subjected to air at 5°C. At the same colonic temperature during cooling, both thyroidectomized and adrenalectomized rats maintained higher skin temperatures than control rats. Heat production (measured by oxygen consumption) was determined for thyroidectomized and control rats only. At the same colonic temperatures during cooling, thyroidectomized rats had the same heat production as controls. However, heat loss at a given colonic temperature during cooling was greater for thyroidectomized than for control rats. The inability of thyroidectomized rats to tolerate cold as well as control rats under these conditions was almost entirely due to a more rapid loss of body heat. The cause of failure of heat conservation may be related to changes in vascular reactivity induced by the hypothyroid state.

Submitted on August 1, 1960
Cerebral metabolism of glucose-3-C14, pyruvate-1-C14 and lactate-1-C14 in mental disease
Authors: Sacks William
Published: December 2017

A previous investigation indicated that less brain CO2 was derived from glucose in psychotic patients than in normal subjects and suggested pyruvate and/or lactate as the site(s) of dilution. In this report more direct determinations, using glucose-3-C14, pyruvate-1-C14, dl-lactate-1-C14, d-lactic-1-C14 and l-lactic-1-C14 acids as substrates, have corroborated the decreased cerebral oxidation of carbohydrate by chronic mental patients and indicated pyruvate as the metabolic level at which protein and/or lipid intermediate(s) caused increased dilution. After glucose-3-C14 injection 35% of brain CO2 was derived from glucose in the mental patient and 54% in the normal subject. With pyruvate-1-C14 initial values for brain C14O2 activities were lower in mental patients. Using dl-lactate-1-C14 over-all body metabolism was reduced in psychotics, whereas brain catabolism was similar to that of normal subjects. Cerebral oxidation of d-lactic-1-C14 acid was greater in mental patients although over-all body metabolism showed little difference from normal subjects. Using the l-isomer both body and brain catabolism were decreased in mental patients.

Submitted on April 28, 1960
Respiratory control and work of breathing in obese subjects
Authors: Gilbert Robert , Sipple John H. , Auchincloss J. Howland
Published: December 2017

Lung volumes, arterial blood gases, respiratory control system sensitivity, and oxygen cost of breathing were studied in obese but otherwise normal individuals and compared to similar studies in nonobese control subjects. Respiratory control system sensitivity as measured by the response to 5% carbon dioxide in air was normal in most obese subjects but reduced in certain obese individuals indistinguishable from the others on the basis of clinical evaluation or resting air studies. While breathing 5% carbon dioxide, the ventilation required to maintain any given alveolar carbon dioxide tension was directly dependent on weight. Oxygen cost of breathing in the ventilation range of 10–30 l/min. was elevated in 4 of 12 obese subjects, and in 6 of 9 obese subjects in the range of 20–40 l/min. There was no correlation between oxygen cost of breathing and respiratory control system sensitivity.

Submitted on April 29, 1960
Respiratory consequences of passive body movement
Authors: Dixon M. E. , Stewart P. B. , Mills F. C. , Varvis C. J. , Bates D. V.
Published: December 2017

The respiratory consequences of a number of passive body movements have been investigated in a group of normal subjects. It has been shown that certain types of torso movement produce hyperventilation in excess of metabolic demand, with a consequent lowering of end-tidal CO2 tension. Passive pedal motion of the legs did not produce this type of hyperventilation and concealed it if performed in conjunction with the other movements. The mechanism for the passive hyperventilation is not understood, since the respiratory rate did not appear to be rhythmically linked to the body movement, and certain maneuvers in the experiments did not affect the results. The level of hyperventilation that has been demonstrated is considered to be adequate to explain the phenomenon of hyperventilation which has been recorded in pilots flying high-velocity low-level aircraft, who may be subjected to considerable jolting while sitting in an upright position.

Submitted on May 10, 1960
Lung changes and incidence of respiratory arrest in rats after aspiration of sea and fresh water
Authors: Halmagyi Denis F. J.
Published: December 2017

Some effects of intratracheal administration of 0.1 ml/100 gm body weight of fresh and sea water were studied in intact and vagotomized rats. No local changes were seen in the lungs after fresh water inhalation. A marked increase in lung weight and intra-alveolar hemorrhages developed following the aspiration of sea water. Fatal respiratory arrest occurred in some cases of salt water and cold fresh water inhalation. Bilateral cervical vagotomy prior to the intratracheal fluid administration failed to affect the incidence of respiratory arrest.

Submitted on November 30, 1959
Some cardiorespiratory parameters in anesthetized sheep
Authors: Halmagyi Denis F. J. , Colebatch H. J. H.
Published: December 2017

Ventilated volumes, oxygen content and carbon dioxide tension in the arterial blood, cardiac output, venous admixture, systemic and pulmonary arterial pressures, and lung compliance were determined in 50 anesthetized sheep. Mean values and standard deviations are described and compared with values obtained in 11 unanesthetized sheep.

Submitted on July 25, 1960
Effect of inflation of the lung on different parts of pulmonary vascular bed
Authors: Howell J. B. L. , Permutt Solbert , Proctor D. F. , Riley R. L.
Published: December 2017

In excised lungs of dogs, the static pressure-volume characteristics of the vascular bed were determined with the vessels filled with dextran and again after replacement of the dextran with kerosene. Whereas the dextran was distributed throughout the entire vascular bed, the kerosene was distributed only in relatively large vessels due to interfacial tension. Volume-pressure curves obtained with kerosene were markedly different from those obtained with dextran. Utilizing both types of volume-pressure curves, it was possible to separate the vascular bed of the lung into two compartments that responded oppositely to inflation of the lung when vascular pressure was held constant: one compartment, consisting of relatively large vessels, always increased in volume; the other compartment, consisting of smaller vessels, always decreased in volume.

Submitted on June 9, 1960
Distensibility of digital blood vessels in cold environment
Authors: Hyman Chester , Arthur James D. , Trotter Alfred Don , Humphreys Patrick C. , Winsor Travis
Published: December 2017

To determine finger-tip vascular distensibility when all of the vessels are subjected to a uniform pressure, an appropriate plethysmograph is used to follow the increase after local venous occlusion. When the finger shows no further systematic increase in volume (volume B), an arterial occlusion is applied to the upper part of the arm. Blood will then flow from the high pressure parts of the vascular bed of the finger tip until the pressure level is related to the venous occlusion cuff pressure to give a new volume (C). Release of the venous occlusion cuff permits all of the blood vessels in the finger tip to come into equilibrium with the pressures in the vessels of the arm to give a measure of the volume (D) contained at the low pressure. The difference between volumes C and D represents the distention of the entire vascular bed of the finger tip for the pressure difference between the occlusion and the final static pressure level. When subjects are exposed to a cold environment, distensibility of the finger-tip vessels decreases, with evidence for involvement of both high- and low-pressure vessels.

Submitted on September 19, 1960
Effect of altitude on endurance running of Peromyscus maniculatus
Authors: Hock Raymond J.
Published: December 2017

One subspecies of deer mouse is distributed from the floor of Death Valley to the tops of California's highest peaks. Endurance studies were made on two populations from 4,000 and 12,470 ft, respectively, at the Owens Valley and Barcroft Laboratories of the White Mountain Research Station. Mice ran on a treadmill at a speed of 40 m/min and an inclination of 50 % (22.5 deg). Studies were made in February and March, so all animals used were adults. The mean of 25 performances by valley mice was 15.8 min; the mean of 22 performances by mountain mice was 7.5 min. The chief factor of difference between the two groups is in the reduced pO2 of the mountain environment and consequent hypoxia at this altitude. However, customary ambient temperatures are quite different, although room temperatures in which the animals were kept were similar. Although there is a possible differential effect of the same ambient temperature on the two mice populations, it was not discernible within each population except possibly in those trials run at over 20 C.

Submitted on August 11, 1960
H+ and pCO2 as chemical factors in respiratory and cerebral circulatory control
Authors: Lambertsen C. J. , Semple S. J. G. , Smyth M. G. , Gelfand R.
Published: December 2017

The relationships of changes in respiration and brain blood flow index to alterations in arterial and internal jugular venous blood pCO2, [HCO3-], and pH were studied in normal men. Observations during control of alveolar pCO2, first at 44 and then at 50 mm Hg, represented the effects of CO2 breathing. Intravenous infusion of NaHCO3 solution (ca. 2.4 mEq/kg) while maintaining alveolar pCO2 at 50 mm Hg revealed the responses to a lowering of blood [H+] without concurrent change in arterial or internal jugular venous pCO2. Brain blood flow index varied directly with alteration in blood pCO2 and was unaffected by changes in blood pH not produced by pCO2 change. Respiratory measurements indicated a prominent relationship between respiration and blood hydrogen ion concentration, the reversal of the acidemia normally associated with CO2 administration removing approximately 45% of respiratory stimulation induced by hypercapnia. The remaining 55% of the increased ventilation caused by CO2 breathing was not directly related to changes in arterial or internal jugular venous blood pH or [HCO3-]. The residual respiratory effect of CO2 administration was correlated, not only with alteration of pCO2, but with calculated changes in the pH of cerebrospinal fluid. Thus, the total respiratory stimulation produced by CO2 breathing, and its diminution by bicarbonate infusion, can be quantitatively described either in terms of a single stimulus index, hydrogen ion concentration, or in terms of two factors, pH and pCO2. Choice between single and multiple acid-base factors as indices of chemical stimuli in respiratory control remains arbitrary. However, the discussion re-emphasizes that, while respiratory changes do occur when blood pH is altered without change of blood or central pCO2, comparable stimulant effects of molecular CO2 cannot be demonstrated without somewhere producing concurrent modification of pH.

Submitted on August 22, 1960
Causes of loss of consciousness during underwater swimming
Authors: Albert B. , Craig JR.
Published: December 2017

Several incidents of losing consciousness while swimming underwater are known to the author. Experiments were designed to find out how this could happen. Four types of breath holding were executed: a) at rest, b) after hyperventilation, c) during mild exercise, and d) after hyperventilation and during exercise. At the breaking point the subject made a maximal expiration, and the end tidal air was analyzed for O2 and CO2. It was found that when the breaking point was reached, the Pco2 was higher and the Po2 lower during exercise than at rest. The lowest Po2 was observed after the subject had exercised following hyperventilation: the Po2 was 34 mm or below in 4 of the 12 subjects, a degree of hypoxia often associated with unconsciousness. Other experiments including underwater swimming support the conclusion that loss of consciousness after hyperventilation and during exercise is possible and is probably due to hypoxia.

Submitted on December 30, 1960
Changes in erythrocytes resulting from excessive shrinking
Authors: Valdivieso Darío , Hunter F. R.
Published: December 2017

A change occurs in chicken erythrocytes during suspension in salt solutions or solutions of nonelectrolytes in Locke-Ringer solution with an osmotic pressure three to four times that of the original cells. If the cells shrink and then swell in less than 10 min this change does not occur. The changed cells are more fragile than normal cells. They have less potassium but more sodium. Evidently when these erythrocytes shrink to a certain point there is some irreversible change. The mechanism for maintaining the cation imbalance between the cell and its environment can break down, and the cells can lose potassium and gain sodium. The cells are highly fragile, and consequently they hemolyze under various circumstances which are not hemolytic to normal cells.

Submitted on November 14, 1960
Lung mechanics and resuscitation after fluid aspiration
Authors: Colebatch H. J. H. , Halmagyi D. F. J.
Published: December 2017

Lung mechanics, arterial oxygen saturation (Sao2) and effective pulmonary capillary blood flow (Qe) were measured before and after intratracheal administration of 1—3 ml/kg body wt. of fresh or sea water in 20 intact and 11 vagotomized sheep during light thiopentone anesthesia. A gross fall in lung compliance (Cl) occurred in all animals after introduction of fresh and sea water; the fall was greater in intact than in vagotomized animals. A variable increase in nonelastic resistance was mainly due to blocking of airways by fluid and foam. Fall in Cl appeared to be the consequence of a reaction within the lungs resulting in a widespread closure of the terminal airways, which was influenced by the vagus nerve but not abolished by vagotomy. By relating Cl and Qe, hypoxemia induced by fluid was explained in terms of altered lung mechanics. Forced inflation increased Cl after fresh water and to a greater extent in vagotomized animals, but produced no change after sea water. A method of resuscitation is suggested based on the change in lung mechanics. With the use of 100% oxygen this method restored normal Sao2 independent of amount of fluid in the lung.

Submitted on December 28, 1960
Effect of a previous deep inspiration on airway resistance in man
Authors: Nadel Jay A. , Tierney Donald F.
Published: December 2017

We measured airway resistance and thoracic gas volume by the body plethysmograph technique, and transpulmonary pressure in seven healthy, adult subjects, before and after induction of bronchoconstriction. A deep inspiration never altered airway resistance, measured at functional residual capacity in the control state, but always reduced it for 1—2 min when bronchoconstriction was present. Discrepancies in data published on airway resistance may be due to use of methods which require a deep inspiration, or to occurrence of a spontaneous deep inspiration shortly before the test.

Submitted on January 13, 1961
Localized multiple minute pulmonary embolism and breathing
Authors: Horres Alan D. , Bernthal Theodore
Published: December 2017

During continuous spirometric recording of breathing, 75–μ glass bead emboli were delivered selectively to single lungs or lung lobes while the remaining lung areas were maintained functionally intact and free of emboli. Postmortem digestion of the lungs revealed the distribution of the emboli and demonstrated complete localization within single lungs or lobes in 12 of 16 experiments. In all instances the frequency of breathing increased and tidal air decreased in a pattern indistinguishable from that attending bilateral multiple minute pulmonary embolism. These effects were abolished by vagotomy but survived inhalation of pure oxygen. Comparison of the quantitative relationship between emboli dose and magnitude of response in localized with that in generalized pulmonary embolization suggests that, within limits, the intensity of the tachypnea is determined by the number of emboli injected regardless of the identity of the gross lung area in which they lodge or the degree of their concentration or dispersion within areas in which they lodge and seems not to favor associated hemodynamic factors as the agency initiating the reflex.

Submitted on January 3, 1961
Cardiac oscillations in expired gas tensions, and regional pulmonary blood flow
Authors: Fowler K. T. , Read John
Published: December 2017

Oscillations in expired gas tensions synchronous with the heartbeat were studied in detail following a tidal inspiration of a gas mixture containing 20.9% oxygen, 20% argon, and the rest nitrogen. A respiratory mass spectrometer continuously analyzed expired gas for argon, oxygen, and carbon dioxide. Simultaneous recordings of expiratory flow rate, expired volume, and electrocardiogram were made where necessary. The gas tension oscillations reflected pulsatile changes in gas flow from regions of different ventilations, blood flows, and Va/Qc ratios. An explanation for the oscillations was developed on the basis of cardiac-induced variations in relative gas flows from upper and lower zones of the lungs. This allowed the identification of these zones with the regions of different Va/Qc ratios, and the calculation of minimum differences in ventilation and blood flow between upper and lower lung zones. Blood flow in the upper lung zones of erect normal subjects was found to be very low, rising considerably on lying down. Three patients with raised left auricular pressures showed high upper zone blood flow in the erect position.

Submitted on February 27, 1961
Estimates of cardiac output from forward part of indicator dilution curves
Authors: Thorburn Geoffrey D.
Published: December 2017

A study was made of 135 dye-dilution curves, 77 of which were obtained from dogs and 58 from man. It was previously shown that the degree of asymmetry of indicator dilution curves varies with changes in flow, volume, and path length, and this has been found to influence the estimates of cardiac output made from the initial part of the curves by the forward triangle and Dow methods, and by a new method described in this paper. This variation may be minimized by the calculation of separate constants for each injection site and by keeping the variation in flow and volume as small as possible. Errors are likely to arise when these methods are used outside the range of the normal data. It has been found that this variation in asymmetry is mainly responsible for the scatter in the estimates of cardiac output using these methods. The agreement between the forward triangle and the Dow methods was found to be very close and the reason for this is discussed.

Submitted on February 13, 1961
Restoration of circulation after fresh water drowning
Authors: Redding Joseph S. , Cozine Richard A.
Published: December 2017

Lightly anesthetized dogs were subjected to obstructive asphyxia, simulating laryngospasm. After respiratory arrest the lungs were flooded with fresh water for 30 sec, according to a standardized experiment. Ten dogs were treated with intermittent positive-pressure artificial respiration with 100% oxygen. Six of the ten dogs suddenly developed ventricular fibrillation less than 2 min after artificial respiration was started. In these animals an artificial circulation was maintained for 20 min by repeated compression of the heart between the sternum and vertebral column. Then, after intravenous administration of hypertonic saline and epinephrine solutions, a 480-v shock was applied to the chest wall. In five of the six dogs there was an immediate resumption of spontaneous circulation. In an additional ten dogs ventricular fibrillation was produced by the same sequence of obstructive asphyxia and flooding of the lungs. In five, treatment was identical except that injection of hypertonic saline was omitted. Circulation was restored in four. In the remaining five, ventilation was performed with air. Restoration of circulation was successful in one.

Submitted on June 12, 1961
Heart rate and forward acceleration
Authors: Steiner Sheldon H. , Mueller Gustave C. E.
Published: December 2017

Cardiac rate was measured in six human subjects during forward acceleration at 8 g and compared with changes in head position while maintaining the remainder of the body in the same position. There was no change in cardiac rate for the 20-sec duration of the plateau with the head in a neutral position (fully supine). The heart rate increased 20% with the head elevated and decreased 16% with the head depressed. Changes in rate are produced by altering the position of the carotid baroreceptors in relation to those located in the trunk, presumably due to alterations produced by acceleration forces in the perfusion pressures in the carotid arteries.

Submitted on February 27, 1961
Maximal oxygen uptake and heart rate in various types of muscular activity
Authors: 0Åstrand Per-Olof , Saltin Bengt
Published: December 2017

Seven subjects performed maximal work of various types. The following exercises were studied: a) cycling a bicycle ergometer in a sitting and b) supine position, c) simultaneous arm and leg work on bicycle ergometers, d) running on a treadmill, e) skiing, f) swimming, and g) arm work (cranking). Vo2 was a few per cent higher in running uphill than in cycling ( a), cranking plus cycling ( c), and skiing, in which events similar values were attained. Heart rate was similar in those types of exercise mentioned ( a, c, d, e). Supine cycling ( b) gave a maximal Vo2 that was about 15% lower than in sitting cycling. A similar reduction in maximal Vo2 was noted in swimming. Maximal work with the arms ( g) gave an oxygen uptake that was about 70% of maximal Vo2 when cycling ( a). It is concluded that the aerobic capacity and maximal heart rate are the same in maximal running or cycling, at least in well-trained subjects.

Submitted on June 23, 1961
Respiration in man during metabolic alkalosis
Authors: Stone Daniel J.
Published: December 2017

A steady state metabolic alkalosis was induced in two subjects over a period of several days utilizing oral sodium bicarbonate in dosages of 50 g/day. The purpose of inducing steady state metabolic alkalosis was to study the effects of such a state on the respiratory center responses to inspired gas mixtures, containing carbon dioxide, and to contrast these results with the control studies. The experiment was so designed that the arterial pH in both subjects tended to return toward normal in the presence of significant increases in blood bicarbonate. Repeated study of ventilation responses with room air and 4% and 6% carbon dioxide in inspired air revealed a definite and significant decrease in ventilation response to carbon dioxide during the periods of steady state alkalosis as compared to the control periods. Normal responses returned after some time lag. A consistent rise in paCOCO2 occurred with alkalosis, thus demonstrating respiratory compensation. In neither subject was total lung function or gas exchange affected by the alkalosis. The experiment was confirmed on several occasions with reproducible results.

Note:

(With the Research Assistance of Mary Di Lieto)

Submitted on May 22, 1961
Circulatory adjustment in pearl divers
Authors: Scholander P. F. , Hammel H. T. , LeMessurier H. , Hemmingsen E. , Garey W.
Published: December 2017

A seemingly general feature in the adjustment to diving in various mammals, birds, and reptiles is a slow-down and redistribution of the circulation, leaving muscles, periphery, and certain visceral organs with a markedly reduced circulation. This saves oxygen and causes widespread reduction of the energy metabolism. Active as well as quiet diving develops bradycardia without drop in central blood pressure, and lactic acid forming in the muscles during the dive floods the blood when breathing starts. In 31 native skin divers in Australia, diving rarely exceeded 1 min. During the dive, blood pressure stayed normal while heart rate dropped to half; blood lactate (five divers) remained normal but showed an acute rise in the recovery. Evidently humans utilize an adjustment similar to animals. Most of our divers developed various cardiac arrhythmias during the dive, persisting sometimes into the beginning of the recovery. This asphyxial defense seems developed at birth, for fetal bradycardia is common during delivery, and an acute rise of lactic acid after delivery has recently been described. Phylogenetically the mechanism is ancient, for it is found also in fishes when taken out of water.

Submitted on August 7, 1961
Carbon dioxide and acid-base transients during hyperventilation
Authors: Tomashefski Joseph F. , Carter Earl T. , Lipsky Joseph A.
Published: December 2017

Studies were conducted on ten healthy adult males subjected to mechanically induced hyperventilation. Total ventilation was increased approximately 300%. This resulted in a mean arterial carbon dioxide tension decrease to 20 mm Hg and a mean pH increase to 7.60. Observations of the dynamic shifts in carbon dioxide stores were made for a 12-min period after onset of hyperventilation. The total carbon dioxide elimination was determined and compared to the basic metabolic CO2 production to permit estimation of body carbon dioxide depletion. The total carbon dioxide elimination was partitioned into that coming from the tissues, the blood, the lung parenchyma, and the alveolar air. After the abrupt increase in alveolar ventilation, a significant portion of the expired carbon dioxide comes from the lung tissue store and the alveolar gas compartments; this is approximately 140 cc and is eliminated in the first 3 min. After 3 min most of the expired carbon dioxide can be accounted for as coming from blood and tissues.

Submitted on August 9, 1961
Effects of acute controlled exposure to SO2 on respiratory mechanics in healthy male adults
Authors: Frank N. Robert , Amdur Mary O. , Worcester Jane , Whittenberger James L.
Published: December 2017

Eleven healthy, adult, male volunteers were exposed on separate occasions to average levels of sulfur dioxide of 1, 5, and 13 ppm. The subjects were seated in a body plethysmograph, breathing spontaneously by mouth while measurements of respiratory mechanics were made with an esophageal catheter. Exposures lasted 10–30 min and, for each subject, were spaced at least 1 month apart. With one exception the group showed no significant increase in pulmonary flow resistance at the lowest concentration of gas. At both 5 and 13 ppm, flow resistance was elevated, the change being greater at 13 ppm. The change occurred within 1 min of exposure, increased after 5 min but, on the average, showed no further change after 10 min. Four subjects were exposed to 5 or 13 ppm of SO2 for 30 min without exhibiting increases in flow resistance beyond the 1st 10 min. There were no consistent changes in pulmonary compliance, tidal volume, breathing frequency, or pulse rate. The functional residual capacity increased slightly during exposure to 13 ppm.

Note:

(With the Technical Assistance of Eleanor Root)

Submitted on May 24, 1961
Comparison of two iminodibenzil derivatives on restraint-induced ulcers and gastric secretion
Authors: Bonfils S. , Dubrasquet M. , Lambling A.
Published: December 2017

Imipramine [N-(γ-dimethylaminopropyl)-iminodibenzyl HCl] was effective in reducing both the incidence of ulcers induced by several different intensities of restraint stress and the volume and acidity of gastric secretion in the rat. G 31.002 [N-(γ-dimethylaminoisopropyl)-iminodibenzyl HCl], a close congener of imipramine, was studied at comparable doses, but did not alter ulcer incidence or reduce gastric secretion. Since both drugs have similar central nervous system depressant activity, the data suggest that the antiulcer effect of imipramine is due to a direct action on the stomach.

Submitted on May 22, 1961
Hematological changes in long-term perfusion
Authors: Brinsfield D. E. , Hopf M. A. , Geering R. B. , Galletti P. M.
Published: December 2017

Hematological changes were measured in 14 dogs during partial heart-lung bypass procedures of 10 hr duration with an extracorporeal flow approximating 40% of the cardiac output. The changes occurring during the 1st hr of perfusion were identical to those previously reported for short periods of total heart-lung bypass, namely, thrombocytopenia and leukopenia. Later on, however, compensatory mechanisms were manifested by the appearance of a leukocytosis with a shift to the left, a leveling off of thrombocyte counts, and the appearance of nucleated red cells in the peripheral blood. Bone marrow studies revealed stimulation of myeloid tissues. These compensatory responses observed during perfusion were similar to changes which have been described as typical of the postperfusion period after shorter durations of extracorporeal circulation. The trauma inflicted on erythrocytes during extracorporeal blood handling became evident after perfusion as a marked anemia and an increased mechanical fragility of the red cells.

Submitted on September 22, 1961
Energy cost of load carriage
Authors: Goldman R. F. , Iampietro P. F.
Published: December 2017

The relative contributions of rate of progression (1.5–4.0 mph), grade (3–9%), and load (10–30 kg) to total energy cost were determined. The data obtained were integrated graphically with some of the available energy cost data in the literature to provide a useful graph for estimating energy expenditure. It was tentatively concluded that for grade walking over the ranges studied, the energy cost per unit weight is essentially the same whether the weight is of the body or the load.

Submitted on January 8, 1962