bluuebunny/crossref_metadata_2025 huggingface dataset:
Liver lipid as a source of embolic fat
Authors: Owens Guy , Sokal Joseph E.
Published: December 2017

Little attention has been focused on the liver as a source of embolic fat. Despite this, clinical observations are available suggesting a relationship between fatty livers and the frequency and/or degree of fat embolization. By combining whole organ perfusion techniques and dietary production of fatty livers in experimental animals, a tool for evaluating the liver and its role in fat embolization has been developed. Fatty livers were produced in adult rats within 12 days by employing a high fat choline-free diet. One group of animals so prepared served as nonperfused tissue controls. Livers from normal and special dietary animals were removed and perfused for periods up to 4 hr. All tissues were frozen and then sectioned after 24-hr fixation in 10% formalin and stained with flaming red and hematoxylin. Nonperfused livers from animals on a choline-free diet revealed intense intracellular lipid concentration, but no fat emboli. Normal livers perfused for 3—4 hr were free of significant accumulation of embolic fat. In contrast, severe embolization was encountered in the perfused fatty livers.

Note:

With the Technical Assistance of Kornel Gerszi and Mary S. Northington

Submitted on May 10, 1961
Quantitative assessment of body build
Authors: Behnke Albert R.
Published: December 2017

A quantitative classification of body build is outlined for adolescents and adults based on 11 circumferences and 8 diameters which can be converted by division with appropriate constants into d quotients. Selected d quotients are then placed in three categories, d( A), d( B), and d( C), which indicate numerically degree of fatness ( A), muscularity ( B), and skeletal size ( C). Equivalent weights, W( A), W( W), and W( C) can be derived from d( A), d( B), and d( C), and in fractional proportions add up to body weight. The anthropometric rating is in terms of A, B, and C, each component related to the other two. The A and B components derived from circumferences can be related directly to body weight. The C component based on skeletal diameters requires further evaluation in relation to chemical and biophysical analysis of body structure. The d quotients when related to body weight or lean body weight provide the basis for a somatogram which depicts intraindividual variations of the various measured parameters as deviations from (See PDF). The system with invariant conversion constants, specific for each sex, has been adequate to describe numerically the fat, muscular, and skeletal components of body build both in the male and female over an age range of 14—93 years, and with variation in stature from 150 to 200 cm and in weight from 40 to 150 kg.

Submitted on June 5, 1961
Influence of unilateral endurance training on contralateral limb
Authors: Hodgkins Jean
Published: December 2017

Forty-one women college students were tested to determine the effect of unilateral endurance training on the contralateral limb. Endurance was defined as the maximum number of times a subject, seated on a table, could lift an 18-lb boot from one prescribed point to another at a given rate of speed. Initial endurance of the quadriceps muscle group in each leg was established. For the next 3⅓ weeks each subject trained three times a week to increase endurance in one leg. At the end of the training period the endurance of the untrained limb was again tested. Through training, the mean increase in endurance of the active limb was 435.71 or 966%. The mean increase in endurance of the inactive or untrained limb was 145.34 or 275%.

Submitted on April 17, 1961
Effect of body temperature reduction on response acquisition in mice
Authors: Essman Walter B. , Sudak Frederick N.
Published: December 2017

In four experiments designed to determine the effects of a moderate reduction of body temperature on response acquisition mice were treated with either 2,4-dichlorophenoxyacetic acid or saline in combination with cold exposure. In a four-trial water-escape problem, normothermic animals acquired the response but hypothermic mice did not show learning. A temperature-dependent relationship to learning was demonstrated.

Note:

(With the Technical Assistance of J. R. Blumstein)
Effect of body posture on gas distribution in the lungs
Authors: Bouhuys Arend , van Lennep Hans J.
Published: December 2017

Postural changes of functional residual capacity (FRC) and pulmonary N2 clearance efficiency were studied in six male subjects placed supine on a tilting table, in head-up, horizontal and head-down positions. FRC varied linearly with the angle of tilt. The lung clearance index (LCI) increased significantly in the supine and head-down positions, compared to the head-up positions, which indicates less uniform gas distribution in the former postures. This was confirmed by analysis of semilogarithmic graphs of N2 washout. Inhalation of epinephrine did not affect the postural changes of FRC and LCI, but caused a small increase of LCI irrespective of posture. The increased uneven distribution in head-down and supine positions is probably a consequence of the lung volume decrease in these postures, and may be explained by mechanical factors such as surface tension, which tend to close lung units when the lungs are deflated. Bronchomotor tone has no appreciable influence on these postural changes in normal subjects.

Submitted on July 13, 1961
Correlation of hemodynamic events during infusion of epinephrine in man
Authors: Allwood Michael J. , Keck Ernst W. , Marshall Robert J. , Shepherd John T.
Published: December 2017

Changes in cardiac output, stroke volume, and systemic blood pressure have been correlated with changes in muscle blood flow during the periods of initial transient and subsequent sustamed vasodilatation during intravenous infusion of epinephrine. In the initial phase blood pressure decreased slightly; forearm blood flow increased by 308%, cardiac output by 50%, and stroke volume by 10%. During the sustained phase the systolic blood pressure increased; corresponding increases for the other measurements were 87, 47, and 25%, respectively. The lack of correlation between these changes in cardiac output and forearm blood flow suggests that in the transient phase vasodilatation does not occur simultaneously in all muscle groups. Stroke volume makes a greater contribution to the increased output during the sustained phase.

Submitted on May 29, 1961
Effect of mild hypoxia on ventilation during exercise
Authors: Hornbein Thomas F. , Roos Albert
Published: December 2017

Hypoxia of mild degree (PaOO2 above 60 mm Hg) produces little or no ventilatory response in resting man during the steady state. To evaluate the possibility that the effectiveness of a hypoxic chemoreceptor drive might be enhanced by exercise, the ventilatory response to mild hypoxia was measured in two human subjects during rest and exercise. Though no significant increase in ventilation occurred at rest above a PaOO2 of 60 mm Hg, a decrease in PaOO2from 100 to 94 mm Hg produced a statistically significant increase in steady state ventilation during moderate exercise. In addition, temporary block of the sympathetic innervation to the carotid and aortic bodies in one subject resulted in a diminution of work hyperpnea. This suggests that increased sympathetic tone during exercise, by reducing blood flow through the chemoreceptors, might result in increased neural discharge and hence increased ventilation even though arterial POO2 is the same as at rest. Thus, activity of the chemoreceptors as modified by sympathetic control of their blood supply may be an important determinant of the ventilatory response to exercise. Since work hyperpnea is enhanced by even mild hypoxia, this ventilatory response may be sufficient to initiate respiratory acclimatization to altitudes so low that resting ventilation on acute exposure is unaffected.

Submitted on July 31, 1961
Primary hypocapnia: a cause of metabolic acidosis
Authors: Eichenholz A. , Mulhausen R. O. , Anderson W. E. , MacDonald F. M.
Published: December 2017

In the presence of severe, sustained hypocapnia produced in dogs by mechanical hyperventilation, a bicarbonate deficit has been observed. The development of this deficit was progressive and did not terminate at pH compensation. The consequence of this progressive deficit was metabolic acidosis. Simultaneous with the increasing bicarbonate deficit, a rise in lactic and pyruvic acids was observed. Most of the bicarbonate deficit could be accounted for by the rise in the organic acids. In a series of experiments in which pH and pCO2 have been independently controlled, the rise in lactic and pyruvic acids was only associated with reduced pCO2. No rise in lactic and pyruvic acids occurred during hypoxia unless associated with hypocapnia. The rise in lactic and pyruvic acids plays a major role in the compensation for respiratory alkalosis. This process of compensation, although homeostatic in regard to pH, may be considered a pathologic state characterized by a progressive bicarbonate deficit. This deficit may be extensive enough to result in metabolic acidosis.

Note:

(With the Technical Assistance of J. Sellner, C. Pfeffer, and D. Larson)

Submitted on November 29, 1961
Some effects of breath holding and apneic underwater diving on cardiac rhythm in man
Authors: Olsen C. Robert , Fanestil Darrell D. , Scholander Per F.
Published: December 2017

Man's bradycardic response to simple breath holding was augmented by submersion in water of 27 C and was not prevented by muscular exercise. Cardiac arrhythmias occurred with 45 of 64 periods of apnea in 16 subjects and were more frequent during the dives than during breath holding. These arrhythmias, with the exception of atrial, nodal, and ventricular premature contractions, were inhibitory in type and included sinus bradycardia and arrhythmia, sinus arrest followed by either nodal escape or ventricular escape, A-V block, A-V nodal rhythm, and idioventricular rhythm. T waves frequently became tall and peaked during both breath holding and dives. Prompt return to normal sinus rhythm was the rule with the first breath after surfacing. Sinus tachycardia, sinus arrhythmia, and atrial, nodal, or ventricular premature contractions were seen during recovery.

Submitted on October 9, 1961
Effect of arterial pressure on arterial and venous resistance of intestine
Authors: Johnson Paul C. , Hanson Kenneth M.
Published: December 2017

The effect of local alteration of arterial pressure on arterial and venous resistance of the intestine was investigated by means of the Pappenheimer isogravimetric technique. Reduction of arterial pressure caused a decrease in total vascular resistance in 70% of the experiments (autoregulation). This response was localized to the arterial portion of the circuit, specifically to vessels less than 0.5 mm o.d. Also associated with the reduction in arterial pressure was an increase in venous resistance. Venous resistance increased threefold as arterial pressure was reduced from 100 to 30 mm Hg. This venous response was seen in all preparations tested. It is suggested that both the venous response and autoregulation of arterial vessels aid in maintenance of a normal capillary pressure.

Submitted on November 6, 1961
Arterial oxygen saturation during exercise at high altitude
Authors: West J. B. , Lahiri S. , Gill M. B. , Milledge J. S. , Pugh L. G. C. E. , Ward M. P.
Published: December 2017

Arterial oxygen saturations were measured on six members of the Himalayan Scientific and Mountaineering Expedition, 1960–61, during a wintering period at 19,000 ft (5,800 m; Pb 380 mm Hg). The determinations were made by ear oximetry and by the analysis of venous blood from the heated hand during rest and exercise at work levels up to 1,200 kg-m/min. Expired gas volumes and gas concentrations were also measured. The average arterial oxygen saturation at rest was 67%, and at work levels of 300 and 900 kg-m/min it was 63 and 56%, respectively. Several readings of less than 50% saturation were recorded during severe exercise. The progressive fall in arterial oxygen saturation as the work level was raised occurred in spite of an increasing alveolar oxygen tension, and the resulting large alveolar-arterial oxygen differences can be explained by the diffusion limitations of the lung.

Submitted on January 12, 1962
Intravascular and intracardiac blood temperatures in man
Authors: Afonso Skoda , Rowe George G. , Castillo Cesar A. , Crumpton Charles W.
Published: December 2017

Intracardiac and intravascular blood temperatures were measured in a group of 17 afebrile patients undergoing cardiac catheterization. Using a cardiac catheter with a thermistor mounted at the tip, measurements were made in the following locations: different levels of the inferior vena cava, the superior vena cava, the renal, hepatic, and internal jugular veins, the right atrium, pulmonary artery and pulmonary artery wedge position, coronary sinus and right ventricle, and the left atrium and pulmonary veins (in subjects with atrial septal defects or patent foramen ovale). Data obtained confirm and extend observations made by other investigators. The blood temperature in the pulmonary artery, pulmonary artery wedge, left atrium, and pulmonary vein were found to be very nearly the same. Furthermore, temperature recordings made in different sites of the inferior vena cava, superior vena cava, right atrium, and pulmonary artery show variations phasic with respiration. The mechanism of these thermal variations is discussed.

Submitted on February 5, 1962
Minute ventilation as a measure of energy expenditure during exercise
Authors: Malhotra M. S. , Ramaswamy S. S. , Ray S. N. , Shrivastav T. N.
Published: December 2017

Studies were made on energy expenditure (E) and minute ventilation (MV) during performance of various military and other tasks by 58 subjects with 495 observations. The capacity for oxygen extraction varies between individuals depending on their physical development and working habits. It is suggested that for determining energy expenditure from minute ventilation, it is necessary to group the individuals on the basis of duty or occupation. For each group, a relationship has to be worked out between E and MV, after taking 16 observations on different subjects. This relationship (max. error ± 4.7%) can then be utilized for field surveys within that group without any further gas analyses. For Indian soldiers E = 0.215 x MV; for Indian Olympic hockey players E = 0.273 x MV.

Submitted on October 24, 1961
Resting arteriovenous oxygen difference and exercise cardiac output
Authors: Thomas H. Duke , Gaos Carlos , Reeves T. J.
Published: December 2017

Measurements of the cardiac output utilizing the classical Fick method were carried out in 38 cardiac patients at rest and during exercise. The predicted cardiac output during exercise was calculated by the regression equation derived by Donald et al. ( Clin. Sci. 14: 37, 1955), relating cardiac output to oxygen consumption during the steady state of exercise in normal subjects (cardiac index = 3.708 + 0.00534 x O2 consumption, ml/min m2). The resting arteriovenous oxygen difference was found to correlate much better with the calculated percentage of predicted cardiac index during exercise (γ = 0.547) than did the resting cardiac index (γ = 0.304). The finding of an arteriovenous oxygen difference greater than 5.16 ml/100 cc indicated a strong probability of subnormal cardiac index during exercise relative to the oxygen consumption.

Submitted on June 18, 1962
Effect of shape-volume changes on uptake of CO and O2 by hemoglobin in erythrocytes
Authors: Sirs John A.
Published: December 2017

Spectrophotometric measurements have been made of the effect of variation of the ionic strength, and equivalent molar concentration of sucrose, on the rate of uptake of CO and O2 by reduced erythrocytes. Cyclic variations of the rate of uptake by as much as 30% have been observed as the ionic strength is altered. The rate of uptake under these conditions is not proportional to the gas concentration. An analysis of these effects suggests the predominant factor is shape-volume changes which alter the membrane permeability. Similar observations have been made on the effect of pH variations. An optimum rate of uptake occurs at pH 7.4.

Submitted on September 21, 1961
Pulmonary diffusing capacity for CO and hemodynamic changes in isolated perfused cats' lungs
Authors: Duke Helen N. , Rouse W.
Published: December 2017

The diffusing capacity for CO (Dco) measured in isolated blood-perfused cats' lungs by a modified steady-state method is 0.7 ml/mm Hg min (sd ± 0.25 ml/mm Hg min). The Dco is increased by increasing the rate of pulmonary arterial inflow or by increasing the left atrial pressure at constant rate of pulmonary arterial inflow. Reduction of left atrial pressure or pulmonary arterial inflow rate under the same conditions reduces the Dco. The Dco is closely related to pulmonary arterial pressure, mean pulmonary vascular pressure, and pulmonary vascular resistance. Changes of pressure and resistance have similar effects on Dco, whether they are produced by alterations of left atrial pressure or pulmonary arterial inflow rate.

Submitted on April 6, 1962
Evidence that the Pco2 of mixed venous blood is not a regulator of ventilation during exercise
Authors: Storey Winnifred F. , Butler John
Published: December 2017

We studied 10 patients with intracardiac left-to-right shunt and 13 patients with other cardiac lesions during exercise. The hyperpnea of muscular exercise was independent of the mixed venous Pco2. In the 13 patients without shunt both the pulmonary arterial Pco2 and the ventilation increased during exercise. In the 10 patients who had shunts ventilation increased during exercise even when the Pco2 in the pulmonary arterial blood did not rise.

Submitted on July 5, 1962
Lung volumes and ventilatory responses to high CO2 and low O2 in the ama
Authors: Song S. H. , Kang D. H. , Kang B. S. , Hong S. K.
Published: December 2017

Various respiratory functions were determined in 20 ama (diving women) as well as in an equal number of nondivers (control group.) The vital capacity was significantly larger in the ama than in the control; this is entirely due to the higher inspiratory capacity in the former group. Neither the residual volume (RV) nor the expiratory reserve volume showed any difference between the two groups. Hence, the RV/TLC ratio tended to be lower in the ama. MBC was considerably higher in the ama. The maximal inspiratory pressure for any given lung volume was significantly higher in the ama, while the maximal expiratory pressure was not different between the two groups. The resting alveolar gas composition is not different from that of the control. The ventilatory responses to breathing 3% and 5% CO2 in O2, as well as the ventilatory responses to breathing 8.5% O2 in N2, were measured and are discussed. It is suggested that some of these differences in pulmonary function between the ama and control group represent long-term adaptations of the divers acquired by engaging daily in diving operations.

Submitted on September 28, 1962
Bradycardia in human divers
Authors: Irving Laurence
Published: December 2017

Electrocardiograms showed bradycardia developing in men and women during apnea in air and more markedly when submerged in water. Intervals between heartbeats reached 2 sec. The onset and degree of bradycardia were not reduced by vigorous swimming underwater. The bradycardia appeared with more regularity and in greater degree in practiced and capable swimmers. The rapidity of onset of this bradycardia indicates that, as in many natural diving animals, it is reflexly initiated.

Submitted on September 4, 1962
Specificity of H ion concentration as a carotid chemoreceptor stimulus
Authors: Hornbein Thomas F. , Roos Albert
Published: December 2017

The present study was designed to separate quantitatively the relative contributions of (H+) and Pco2 as chemoreceptor stimuli. The integrated electrical activity from the entire Hering's nerve of the cat was measured and correlated with values of (H+), Pco2, and Po2 of arterial blood. By utilizing a combination of respiratory and metabolic acidosis or alkalosis, the effect of (H+) on carotid body nerve activity could be separated from that of Pco2. Most studies were performed at high Po2, a few against a changing hypoxic background. The results indicate: 1) the pre-eminence of (H+) as a chemoreceptor stimulus, CO2 acting only by virtue of its effect in altering (H+); 2) the relationship between (H+) or Pco2 and chemoreceptor activity is nonlinear; 3) the potentiation between hypoxia and hypercapnia at the chemoreceptor level is due primarily to interaction between low oxygen tension and increased (H+), independent of Pco2. The significance of these findings to the exchange of CO2 and of (H+) and (HCO3-) ions between the intracellular and extracellular milieu of the carotid chemoreceptor cells is discussed.

Submitted on September 28, 1962
Reversible cooling of cerebellum in awake, unrestrained rats
Authors: Manni Ermanno , Mills Laurence W. , Dow Robert S.
Published: December 2017

A method has been developed for producing reversible cooling of the cerebellum in awake, unrestrained rats. A technique is described for covering the cerebellar cortex with a piece of thin platinum foil. Cooling of the cerebellum in the awake animal was accomplished by placing granules of dry ice in contact with the foil. After the effects of cerebellar cooling had been observed repeatedly in the awake, unanesthetized animals, the rats were once again anesthetized in order that subcortical temperature changes could be measured. The magnitude of the temperature changes was correlated with distance from the foil. The temperature of subcortical cerebellar tissue 2–6 mm below the platinum foil dropped 10 C in 4–5 min after application of the dry ice.

Submitted on August 8, 1962
Blood lactates after prolonged severe exercise
Authors: Åstrand Per-Olof , Hallbäck Inger , Hedman Rune , Saltin Bengt
Published: December 2017

Blood was drawn from cross-country skiers at 1–3 min after the finish in competitions on distances from 10 to 85 km and the blood lactate determined. Despite a maximal effort of the skiers, accentuated at the end of the race, there was a successive decrease in the blood lactate concentration with work time. After a 10-km race, work time 35–36 min, the average was 139 mg/100 ml of blood (12.5 mEq/liter); after a 30-km race, with a time of 1 hr 50 min-1 hr 56 min, the mean value was 68 mg/100 ml (6.1 mEq/liter); and after a 50-km race, work time 3 hr 6 min-3 hr 18 min, 39 mg/100 ml (3.5 mEq/liter). A lactate concentration exceeding 100 mg/100 ml is a common finding after maximal muscular exercise involving large muscles. The explanation for the low values after prolonged maximal work, indicating a different kind of fatigue, is presently obscure. Data are presented on the oxygen uptake attained during skiing at actual racing speed (average Vo2 = 4.45 liters/min).

Submitted on July 16, 1962
Tissue studies during recovery from immobilization atrophy
Authors: Eichelberger Lillian , Roma Michael , Moulder Peter V.
Published: December 2017

Immobilization of one hind leg of puppies was produced at 12 weeks of age. After 6 weeks of immobilization, the immobilized muscles were restored to weight bearing. The opposite leg was the control leg. To study recovery from atrophy in these muscles, biochemical analyses and histochemical patterns of the muscles were used. Recovery periods varied from 55 to 300 days. In the 91-day remobilization group there were increased values in the interfiber constituents as well as decreases in the intrafiber constituents, but values were not as large as in immobilization only. After 300 days of remobilization the formerly atrophic muscles had regained the same concentration as in the control muscles, indicating recovery. The histochemical patterns of 1 kg of control muscle and remobilized muscle were traced. The ultrafiltrate volume in the groups up to 91 days of remobilization was increased in amounts over the control volumes, but the increases were not as large as in immobilization only. In 300-day group all volumes were the same as in the control, indicating recovery from atrophy, according to these criteria.

Submitted on November 12, 1962
Pulmonary diffusing capacity of athletes
Authors: Mostyn E. M. , Helle S. , Gee J. B. L. , Bentivoglio L. G. , Bates D. V.
Published: December 2017

Champion swimmers have been found to have significantly higher steady-state pulmonary diffusing capacities than those measured in normal subjects of comparable age at the same exercise level. Nonactive and moderately active normal subjects, swimmers of average ability, long distance runners, and older ex-athletes were found to show no significant deviation from predicted values of DlCO, either in absolute terms or in relation to body surface area or lung midcapacity. The high DlCO in champion swimmers results from a larger than normal pulmonary capillary blood volume (Vc). It has been observed that normal subjects can increase the measured steady-state Dl during exercise by a “held inspiration“ maneuver, but this increase is caused by an increased membrane diffusion component (Dm) per liter midcapacity and not by an increased Vc. Champion swimmers have a particular need of a high Dl since they must be able to transfer large volumes of oxygen across the lung when the alveolar pO2 has fallen to low levels.

Submitted on August 20, 1962
Cerebrospinal fluid acid-base balance during a changing ventilatory state in man
Authors: Fisher Vincent J. , Christianson Lynn C.
Published: December 2017

Comparison of the rate and magnitude of changes in pH, CO2 tension, and bicarbonate concentration in arterial blood, cisternal spinal fluid, and lumbar spinal fluid was made in man during hyperventilation and recovery. CO2 tension changes in cisternal fluid were rapid and significant, although less in magnitude than those in arterial blood, whereas changes in lumbar fluid CO2 tension were minimal and slow, lagging behind cisternal changes by 10–20 min. The different rates of change following altered ventilation explain some of the reported reversals of the normal lumbar spinal fluid to arterial blood CO2 tension gradients. It also suggests that the choroid plexus is one site of removal of CO2 from spinal fluid.

Submitted on December 13, 1962
Metabolic and thermal responses to muscular exertion in the cold
Authors: Str⊘mme S. , Andersen K. Lange , Elsner R. W.
Published: December 2017

The metabolic and thermal responses to muscular exertion in the cold were studied in outdoor and indoor workers. The metabolic rate during exercise was the same in the cold as in a thermally neutral (warm) environment when workload was sufficiently high to prevent a fall in the rectal temperature. At lower levels of work the metabolic rate in the cold was higher than that in the warm. No significant differences in the work metabolism were found between the groups. When the resting subjects were exposed to the cold environment prior to the exercise the skin temperature decreased. The rate of decrease diminished as exercise progressed and at higher load of work the extra heat generated in the body was enough to rewarm the skin, even on the most peripheral parts. The rate of decrease of skin surface cooling during rest in the cold was found to be slower in the outdoor workers than in the indoor workers, and the onset of the rewarming occurred much quicker in the former. These differences in skin temperature between outdoor and indoor workers indicate an acclimation to cold affecting the vasomotor control of the skin circulation. The hypothesis is suggested that habituation to cold leads to a lower set point of the thermosensitive cells in the thermoregulating center, so that vasodilatation impulses are discharged at a lower temperature.

Submitted on September 17, 1962
Early changes in serum enzymes in the rat following burn trauma
Authors: Spector Arthur A. , Pauli Wayne A.
Published: December 2017

Under ether anesthesia, 30% surface area scalds were administered to young adult rats. Controls were treated similarly except for the scald. The animals were sacrificed at 15 min after injury, and their serum was analyzed for enzyme activities and chemical constituents. Large increases in catalase, glucose 6-phosphate dehydrogenase, lactic dehydrogenase, glutamic-oxalacetic transaminase, and glutamic-pyruvic transaminase activites were noted in postburn serum. No statistically significant change was found in acetylcholinesterase, acid phosphatase, alkaline phosphatase, leucine aminopeptidase, 5'-nucleotidase, or succinic dehydrogenase. Amylase activity was decreased in the burned animals. Serum oxyhemoglobin and inorganic phosphate were elevated, but total protein remained unchanged following trauma. The etiology of the early postburn serum changes is believed to be tissue damage produced by the burn, an important component of which is in vivo hemolysis. A possible relationship between the rapid extracellular buildup of enzymatically active protein and the pathology of burn injury is suggested.

Submitted on November 15, 1962
Metabolism of Sr58 and Ca45 in man after single and multiple doses
Authors: Samachson Joseph
Published: December 2017

Three patients received single doses of Sr85 and one Ca45 as well, the plasma levels, and urinary and fecal excretions being followed for 3–4 weeks. Calculations were then made to predict plasma levels and excretions following the administration of 12 small doses to each patient, and values predicted were compared with those found. Changes in calcium metabolism limited the predictive value of single-dose data, but when variations in urinary calcium could be allowed for, predicted and found values agreed well. The factors involved in extrapolation from single to multiple doses are discussed. Within certain limitations, the extrapolation appears valid and may be applicable to the problems involved in the investigation of Sr90 as well, although the fact that the latter is ingested over long periods of time makes comparison with single-dose data more hazardous.

Submitted on December 21, 1962
Cardiac monitoring and telemetering system
Authors: Furman K. I. , Lupu N. Z.
Published: December 2017

In this system an audio-frequency subcarrier is modulated (FM) by the amplified ECG signal from a test subject. The FM tone produced is transmitted to the stable sections consisting of a receiver, audio-frequency discriminator, and recording apparatus. The apparatus can be used in conjunction with a conventional short-wave radio receiver, and if necessary a conventional tape recorder. The use of an audio-frequency subcarrier enables simple aural monitoring of the heart rate to be made either directly from the apparatus on the subject or after transmission. The ECG is monitored directly from the discriminator output.

Submitted on November 29, 1962
Measurement of oxygen tensions in cerebral tissues of rats exposed to high pressures of oxygen
Authors: Jamieson Dana , Van Den Brenk H. A. S.
Published: December 2017

Brain and cerebrospinal oxygen tensions have been measured in rats breathing air or in various high pressures of oxygen (OHP). Addition of 5% CO2 to the inspired oxygen raised cerebral oxygen tensions when rats were exposed to 2 atm abs or above. Inhibition of 75% hemoglobin saturation by para-aminopropriophenone lowered cerebral pO2 in rats breathing air, but not in rats exposed to OHP. The rate of rise of cerebral pO2 to a steady level after rapid compression was found to be faster than the rate of fall to a steady level following decompression. Addition of CO2 to the inspired gas mixture increased the rate of rise of cerebral pO2. The anesthetics urethane and pentobarbital sodium did not affect cerebral pO2 in rats breathing air or oxygen at 4 atm. The results are discussed in relation to factors contributing to oxygen poisoning at high pressures.

Submitted on October 30, 1962
Effect of vagotomy and vagal stimulation on lung mechanics and circulation
Authors: Colebatch H. J. H. , Halmagyi D. F. J.
Published: December 2017

In sheep, anesthetized and intubated, bilateral cervical vagotomy produced no change in lung compliance (Cl), reduced inspiratory resistance to airflow, increased expiratory resistance to airflow, and changed the pattern of breathing. Electrical stimulation of the peripheral end of the cut vagus nerve produced an immediate increase in lung volume due to an increase in inspiratory tonus, a fall in Cl, an increase in resistance to airflow, and a decrease in heart rate and systemic arterial pressure. Pulmonary arterial pressure remained unchanged; pulmonary arterial resistance increased. These effects were blocked by atropine. The lung mechanics changes were partly reversed spontaneously, completely reversed by forced inflation, and potentiated by prostigmine. The effects on lung mechanics suggest that vagal stimulation in the sheep mainly affects the peripheral airways producing airway closure, and indicates the possibility of a nervous mechanism for the control of the number of ventilated lung units.

compliance; total pulmonary resistance; inspiratory; tonus; peripheral airway reaction; respiratory pattern

Submitted on December 6, 1962
Effect of different pressure breathing patterns on alveolar-arterial gradients in dogs
Authors: Bergman Norman A.
Published: December 2017

Arterial end-tidal carbon dioxide gradients were measured and alveolar-arterial oxygen gradients were estimated in dogs during intermittent positive pressure ventilation at constant inflating pressure using four curves having differing pressure profiles. The smallest gradients for both oxygen and carbon dioxide occurred when mean pressure during respiratory cycles was high and decreases in mean pressure were consistently associated with increases in both oxygen and carbon dioxide gradients. Profile of the applied pressure curve per se did not influence magnitude of the gradients. It is concluded that during intermittent positive pressure breathing, relative distribution of pulmonary capillary blood flow and inspired gas may vary with mean pressure during the respiratory cycle and is more uniform when mean pressure during the respiratory cycle is high.

artificial ventilation; intermittent positive pressure breathing; alveolar-arterial; carbon dioxide gradient; distribution of inspired gas; pulmonary capillary blood flow

Submitted on December 13, 1962
Effect of pulmonary vascular engorgement on Dl during and immediately after exercise
Authors: Krumholz Richard A. , King Leroy H. , Ross Joseph C.
Published: December 2017

Pulmonary diffusing capacity (Dl) is increased more markedly by moderate exercise, which causes little increase in pulmonary vascular pressure, than by inflation of a pressure suit over the lower part of the body, which produces pulmonary vascular engorgement and marked increases in pulmonary pressure. This study was designed to determine whether exercise causes the pulmonary capillary bed to be more permissive to passive dilatation. Dl was determined in 12 subjects before, during, and soon after a period of exercise with and without the pressure suit inflated. Dl was increased in resting subjects by suit inflation, but less than with exercise. Exercise with suit inflation did not increase Dl more than exercise alone. Suit inflation 3 min after exercise ended, however, increased Dl to higher levels than at any other time with suit inflation alone. The pulmonary capillary bed apparently cannot be further dilated by vascular engorgement during exercise beyond that caused by exercise alone. Also, soon after exercise ends, the pulmonary capillary bed is more permissive to passive dilatation by vascular engorgement with suit inflation.

pulmonary diffusing capacity; pulmonary capillary bed; human male

Submitted on June 17, 1963
Tolerance to extreme cold at altitude in a Nepalese pilgrim
Authors: Pugh L. G. C. E.
Published: December 2017

Body temperature and respiratory experiments are reported on a Nepalese pilgrim who survived, uninjured, 4 days of exposure at 15,000–17,500 ft in midwinter, wearing only light clothing and no shoes or gloves. His resistance to cold depended on elevation of metabolism and, unlike tolerance of immersion in cold water, was not related to subcutaneous fat thickness. He slept soundly in spite of the cold and so did not become exhausted. In 3–4-hr experiments at o C (clothed), rectal temperature and skin temperature over the trunk showed only minor changes; hand and foot temperatures did not fall below 10–13 C. Maintenance of body temperature was accounted for by elevation of metabolism.

survival in cold

Submitted on February 19, 1963
Interaction of paired sensory stimuli and conduction in peripheral nerves
Authors: Békésy G. Von
Published: December 2017

It is well known from directional hearing that a sound source is localized in the middle plane when the sound reaches both ears simultaneously. If there is a time difference between the sound's arrival at the two ears, the sound source is localized to one or the other side, depending on which side receives it first. A time difference as small as 1 msec is enough to produce full lateralization. Thus the shift in the localization of a sensation can be used to measure small time intervals. This shift in localization appears to be not a specific ability of the ear, but a general quality of many sense organs with large surfaces. Even in the sense of taste, the position of the sensation on the tongue changes when the time difference between two separately placed stimuli is altered. If the time delay is used to estimate the speed of conduction for different sensations such as touch, warmth, electrical stimulation, and taste, the resulting estimates are greatly in excess of the values obtained by direct measurements as reported in the literature.

brain sensory nerve fiber connections between hemispheres; directional hearing; inhibition in sense organs; taste localization; vibratory localization

Submitted on March 29, 1963
In vitro assessment of cell viability in human bone marrow preserved at -79 C
Authors: Pegg D. E.
Published: December 2017

Human bone marrow was stored at -79 C for 1 hr with glycerol, with dimethyl sulfoxide, or without any protective agent, both after rapid cooling and after slow cooling. Each sample was subjected to four viability tests, and observations were also made on samples stored for 1 hr at room temperature. By comparison with the established effects of these preservation procedures on the radiation recovery factor, it is concluded that: 1) the dye exclusion test using trypan blue is a poor indicator of viability after freezing; 2) the measurement of deoxyribonucleic acid synthesis gives results which correlate well with in vivo assays; 3) the detection of motility is the only in vitro test to provide unequivocal evidence of life, but is not susceptible to quantitative measurement: slow cooling in the presence of glycerol or dimethyl sulfoxide was the most successful preservation procedure used; 4) supravital staining with acridine orange, although it is a purely empirical test, gives a good correlation with the results of in vivo assay and is simple, convenient, and rapid to perform.

cellular viability tests; radiation protective cells; radiation recovery factor; cell survival after freezing; glycerol and dimethyl sulfoxide additives in tissue preservation; slow cooling versus rapid cooling in tissue preservation; trypan blue nuclear staining, DNA synthesis, mobility, and supravital staining as viability tests; bone marrow storage viability tests; glycerol and dimethyl sulfoxide in tissue preservation; low temperature cell preservation

Submitted on May 20, 1963
Human urinary catecholamines in relation to climate
Authors: Feller Ralph P. , Hale Henry B.
Published: December 2017

Urinary catecholamine determinations were employed to appraise human sympathoadrenal activity in different seasons (autumn, winter, and spring), the study being made in a subtropical climate, where maximum temperature in these seasons averaged, respectively, 66, 60, and 74 F. Two hundred and thirty-one healthy men were studied under standardized laboratory conditions, and significant variation with season (P < .01) was established for excretion of both epinephrine and norepinephrine and for the norepinephrine-to-epinephrine ratio, the latter index providing the most clear-cut pattern of variation with season, and suggesting greater activity in the sympathoadrenal system in winter than in autumn, with reversal in spring. Cigarette smoking and anxiety, acting singly or jointly, had modifying effects on climate-induced changes in epinephrine excretion.

chronic cold effects in man; bioclimatology; seasonal sympathoadrenal activity; epinephrine and norepinephrine excretion in chronic cold; smoking and epinephrine excretion; anxiety and epinephrine excretion

Submitted on May 13, 1963
Catecholamine excretion in smokers and nonsmokers
Authors: Westfall Thomas C. , Watts Daniel T.
Published: December 2017

The 24-hr urinary excretion of epinephrine and norepinephrine in nonsmokers was compared to that of a group of heavy smokers using a fluorometric technique. The 24-hr epinephrine excretion in nonsmokers was 6.5 ± 0.8 μg/24 hr; whereas the excretion in smokers was 12.1 ± 0.9 μg/24 hr, a statistically significant difference. There was no significant difference in the norepinephrine output between the two groups. The excretion of epinephrine and norepinephrine was also determined at 30-min intervals before, during, and following heavy smoking in 15 subjects who normally smoked. The results indicate that the epinephrine and total catecholamine excretion levels increase significantly above control levels during periods of heavy smoking. Studies were also done on the effect of smoking one cigarette on the plasma epinephrine levels in three patients undergoing cardiac catherization. Samples were obtained from the inferior vena cava above and below the inflow from the adrenals. Results show that the epinephrine levels were slightly higher in the inferior vena cava above the adrenal inflow during and immediately following cigarette smoking in all three patients.

epinephrine; norepinephrine; nicotine; sympathoadrenal stimulation

Submitted on June 17, 1963
Bio-assay for antidiuretic activity in blood of undisturbed rats
Authors: Little John B. , Radford Edward P.
Published: December 2017

In order to study circulating antidiuretic hormone (ADH) levels in rats unaffected by anesthesia or manipulation, a method is presented whereby blood samples may be obtained through an indwelling aortic catheter without disturbing the animal. An intravenous rat bio-assay for ADH is described which is sensitive to absolute doses of 2–3 microunits U.S.P. posterior pituitary standard. To obtain maximum sensitivity and reliability no surgical procedure was performed on the assay rat on the day of assay, as we have found that despite alcohol anesthesia ADH release may still be stimulated in assay animals. With 0.5-ml plasma samples injected into two assay animals simultaneously, ADH activity as low as 4μU/ml plasma could be reliably detected. Antidiuretic activity of plasma from undisturbed rats was generally below 4 μU/ml, but when ether anesthesia was used plasma levels were highly variable though generally markedly increased. In animals dehydrated for 1–3 days plasma levels averaged 14.6 μU/ml. These values are considerably lower than concentrations previously reported for rats, and the difference suggests the importance of minimal disturbance to the donor animal when blood is obtained. The low plasma levels we have observed in dehydrated rats are nevertheless above the level calculated to produce maximum antiduresis.

ADH determination in circulating blood; vasopressin bio-assay; ADH in rat plasma; ADH levels in undisturbed rats

Submitted on August 19, 1963
Role of hydrochloric acid in iron absorption
Authors: Jacobs Peter , Bothwell Thomas , Charlton Robert W.
Published: December 2017

The absorption of 5 mg iron administered in 300 ml water was compared with absorption from 300 ml 0.05 n HCL in 24 subjects with histamine-fast achlorhydria, using a double isotope technique. In ten individuals given ferric chloride the mean absorptions were 2.2% with water and 9.2% in acid; the difference was less marked in the case of the seven subjects to whom ferrous ascorbate was administered (10.9% and 19.3%, respectively). In contrast, acid did not increase the absorption of hemoglobin iron, the mean figures being 13.4% with water and 9.6% with HCL.

pernicious anemia; achlorhydria; gastric pH Fe55 and Fe59; radioactive hemoglobin iron

Submitted on June 17, 1963
Estimation of tissue elasticity of the lung
Authors: Carton Robert W. , Clark John W. , Dainauskas John , Barron Arnold
Published: December 2017

Theoretical work-volume curves for liquid-filled lungs were constructed based on an assumed geometric form and deformation of the terminal air spaces and on the characteristics of single fibers of elastic tissue. These curves were compared with those measured in rats and with one taken from the journal literature in the case of a human lung. The form of the measured curves fitted the theoretical curves. The assumptions necessary were considered in detail. In both species more elastic tissue has been found present in the lung than would be expected theoretically. The action of additional restraining elements was thought necessary at high volume.

pulmonary pressure-volume curves; pulmonary work-volume curves; lung volume and elastic tissue mass; pulmonary elastic tissue; tissue elasticity; pulmonary mechanics

Submitted on April 22, 1963
Saturation of arterial blood with oxygen during maximal exercise
Authors: Rowell Loring B. , Taylor Henry L. , Wang Yang , Carlson Walter S.
Published: December 2017

The per cent saturation of the arterial blood with oxygen was examined in four men before and during the last 15 sec of a 3-min run of sufficient intensity to elicit a maximal oxygen intake. The measurements were repeated after a 3-month period of intensive conditioning for middle distance running and in a group of four athletes in good physical condition. The per cent saturation in the sedentary group was 95.8 at rest and 93.4 during exhausting exercise; after conditioning the similar figures were 95.4 and 91.4 and, finally, the athletes showed a per cent saturation of 85.2 during the heavy work. The arterial oxygen content during exhausting work was found to be 20.12 ml/100 ml blood in the sedentary group before training, 19.02 after conditioning, and 18.18 in the group of athletes. It is concluded that, in athletes who are well conditioned and pushing themselves close to the limit of their capacity, arterial desaturation can take place.

athletic conditioning and arterial oxygen saturation; arterial desaturation in athletes; ventilation and arterial desaturation; oxygen intake and arterial oxygen saturation

Submitted on August 5, 1963
An ultramicro oxygen electrode
Authors: Fatt Irving
Published: December 2017

The advantages of a 1-μ-diameter platinum cathode in the Clark-type oxygen electrode are shown to be freedom from effects due to flow, stirring, or mechanical pressure. When used with a 5-mil polyethylene membrane the 1-μ electrode shows only a 2% difference between a vigorously stirred solution and the unstirred solution. A mechanical pressure of 200 psi on the 1-μ covered electrode caused only a 20% reduction in current. The use of a 1-μ covered electrode as an implant is suggested.

electrode implant; Clark-type oxygen electrode modification; polarographic electrode; oxygen measurement; platinum electrode

Submitted on March 4, 1963