bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of ammonia on respiration
Authors: Renzetti Attilio D. , Harris Barton A. , Bowen John F.
Published: December 2017

Elevations of the concentration of ammonia in arterial blood to 20 times that of control values, or more, were induced in nine patients by the intravenous administration of an approximately neutral solution of 2 m glycine. During the course of the infusion, increases were observed in uptake of oxygen, output of carbon dioxide, respiratory exchange ratio, ventilation, and arterial pCO2; small reductions in arterial pH accompanied these changes. The net effects observed during glycine administration were metabolic stimulation and relative respiratory depression. A poor correlation (γ = 0.23) was shown to exist between ventilation and the calculated arterial ammonia tension. In addition, in the two patients so studied, the ventilatory response to the inhalation of 5% carbon dioxide in air was decreased during a period in which the concentration of ammonia in the blood was elevated. It is concluded that elevating the concentration of ammonia in the blood to as high as 500 μg/100 ml does not stimulate respiration and may depress it perhaps by changing the pH within chemosensitive cells toward alkalinity.

Submitted on February 28, 1961
Effects of training and competitive swimming on serum proteins
Authors: Johnson Thomas F. , Wong Harry Y. C.
Published: December 2017

The major concern of this investigation was to observe chronic and/or acute effects of a typical intercollegiate training and competitive swimming program on plasma protein levels in young men. Plasma protein levels, followed over a period of 14 months in seven young college men, were analyzed by the technique of paper electrophoresis. No chronic effects in plasma proteins were observed; that is, no permanent change in plasma protein level was seen. Comparisons of data between competitive and noncompetitive seasons showed no significant difference. However, there were acute effects resulting from brief maximal exercise efforts. Albumin increased in response to participation in one or more competitive swimming events. A slight decrease was observed in the beta-globulin fraction. A similar albumin-beta pattern was seen in another group of varsity swimmers sprinting 220 yards. In both instances, the greatest deviation from pre-exercise levels was observed the next morning, some 11—20 hr later. Some of the mechanisms thought to act in causing a temporary alteration in plasma proteins during and after exercise are discussed.

Submitted on October 12, 1960
Ventilation of lungs in deeply hypothermic rats
Authors: Adolph E. F. , Naberschnig A. , Orchard D. P.
Published: December 2017

Ventilation (Vi), oxygen consumption (Vo2) and heart rate (H) were measured at esophageal temperatures (T) of 8—24 C. The trachea was cannulated; a body plethysmograph and pressure transducer registered breath volumes. Vo2 was computed from oxygen content of effluent air. Vi, Vo2, and H were each related to T by a regression of low slope from 8 to 18 C, and a high nearly-linear slope above 18∘ But the proportions among the three parameters changed; Vi was relatively less below 18∘. Breaths were increasingly irregular as T decreased below 24∘. Hypoxia induced greater Vi at 16—21∘, but not at 13∘, nor after excision of the carotid bodies. Vo2 in hypoxia was greatly reduced; at 12—17∘ a Vo2 as low as one-fifth of that in air continued for an hour. H also decreased sharply at Po2 below 50 mm Hg. Carbon dioxide induced faster Vi even at 12∘; its effects were not modified by carotidectomy. Gasps were regularly induced by hypoxia, and usually by hypercapnia; they occurred just as frequently after carotidectomy.

Submitted on October 26, 1960
Cardiovascular response to oxygen inhalation in the anesthetized cat
Authors: Bevan John A. , Verity M. Anthony
Published: December 2017

An analysis of the cardiovascular response to short periods of inhalation of O2 is presented. In cats anesthetized with chloralose, an immediate acute fall in arterial pressure, accompanied by a varying degree of bradycardia was followed by an equilibrium state lower than the control value. Following bilateral vagotomy the initial hypotension was still present but the arterial pressure during the second phase returned to the preoxygen value. With inactivation of the caroticoaortic chemoreceptor regions, no hypotensive effect was seen, but a small, slowly developing hypertension was observed, originating peripherally. A similar, but significantly smaller hypotensive effect was seen in cats under sodium pentobarbital anesthesia. No significant difference in the arterial O2 saturation between animals anesthetized with chloralose and pentobarbital was noted, but in both groups the largest fall in arterial pressure occurred with the greater degree of anoxia. Experiments in which an increased degree of anoxemia was induced demonstrated the significantly different reactivity of the chemoreflex system under the anesthetics studied and suggests the presence of a central selective depression of the tonic anoxic chemoreceptor drive with barbiturate anesthesia.

Submitted on February 27, 1961
Volume-pressure relationships of lungs and thorax in fetal, newborn, and adult goats
Authors: Avery Mary Ellen , Cook Charles D.
Published: December 2017

The physical properties of the lungs and thorax in kids before and after the onset of respiration and in older goats demonstrate changes with age. The fetal goats' lungs contained a volume of fluid which made them approximately twice as heavy as those of animals which had lived a few hours. The intrapleural pressure in the fetus was atmospheric, and was more negative the larger the goat. The pressure-volume characteristics of the lungs and thorax measured in the paralyzed, anesthetized animals show the thorax of the kid to be more compliant and the lungs of the kid less compliant per gram of lung tissue than in the older animal. Studies on excised lungs from these animals show that the lungs of older animals contain a larger gas volume per unit lung weight at pressures over 5 cm H2O than lungs of younger animals.

Submitted on July 19, 1961
Pulmonary venous admixture in man during negative pressure respiration
Authors: Steiner Sheldon H. , Behnke Roy H.
Published: December 2017

Arterial blood gases were measured after 10 min of full-phase negative pressure breathing at a gauge pressure of — 40 mm Hg. Oxygen capacity increased slightly, and oxygen saturation fell from 96.9% to 92.6% in the seated position (P < 0.05) and from 96.0% to 92.2% in the recumbent position (P < 0.05). At this transthoracic pressure differential there would be expected only an 8—10-mm decrease in oxygen tension resulting in a 1% decrease in arterial saturation. pH and calculated pCO2 were not altered. The physiological shunt appeared to increase as evidenced by the arterial desaturation. If blood is redistributed away from poorly ventilated regions, the redistribution is not complete during negative pressure breathing at this magnitude. Although there appears to be an increased shunting, it is quite small compared to that reported in the anesthetized dog at only —20 mm Hg. The differences are probably related to the effects of anesthesia causing a decrease in lung volume and tidal volume. Forward acceleration has been said to simulate negative pressure breathing. However, the arterial saturation at 8 g was 75%, and 8 g has been estimated as being equivalent to —28 mm Hg (—3.5 mm Hg/g). Therefore, the degree of arterial desaturation during forward acceleration is more reasonably related to the hydrostatic effects than to possible negative pressure breathing effects.

Submitted on May 1, 1961
Effect of citrate on ultrafiltrable and ionic calcium concentrations in serum
Authors: Peterson N. A. , Crismon J. M.
Published: December 2017

The effect of citrate on the concentration of ultrafiltrable and ionic calcium in blood serum and bovine serum albumin (BSA) solutions was studied. Theoretical equations were derived which predict the fractions of total calcium (in simultaneous equilibrium with protein and citrate) which are ultrafiltrable and ionized. The predictions were made directly from concentrations of total protein, calcium and citrate, and pH. Ultrafiltration experiments on purified BSA, rabbit serum containing added citrate, and human blood-bank serum with acid citrate dextrose solution, yielded data which were in good agreement with predicted values. Additional experiments were performed in order to obtain an empirical expression relating pH to the dissociation of calcium proteinate in normal human serum.

Submitted on July 3, 1961
Effect of skin temperature on absolute threshold for electrical current
Authors: Hawkes Glenn R.
Published: December 2017

The dependence of tactile sensitivity on skin temperature could be due to a central or a peripheral effect. Maximal cutaneous sensitivity for pressure or mechanical vibration is obtained at about 36 C, with a shift in either direction resulting in an elevation of threshold. In the present study, raising skin temperature of the finger or forearm to as much as 45 C had no effect on the threshold for electrical cutaneous stimulation. It is concluded that the dependence of sensitivity to pressure or mechanical vibration on skin temperature is a peripheral effect. Further, electrical current applied to the intact skin apparently affects nerves directly without requiring transduction by a chemical (or other) process at the receptor. It is suggested that the effect of temperature, with other kinds of cutaneous stimulation, is on chemical substances contained within the receptors.

Submitted on July 20, 1961
Films from lung washings as a mechanism model for lung injury by ozone
Authors: Mendenhall Richard M. , Stokinger Herbert E.
Published: December 2017

Saline washings of the mouse lung were layered on various hypophases. With serum dialysate present in the hypophase, film pressure in the presence of ozone increased over that in its absence. Addition of Tapazole (2-methyl-1-mercaptoimidazole) or AET (aminoethylisothiouronium bromide-HBr) protected the films from the action of ozone if serum dialysate was present in the hypophase, but film pressures were rapidly reduced in its absence. Both Tapazole and AET protect mice from otherwise lethal doses of ozone. The results indicate the presence of a surface-active film in the alveolus which, together with the hypophase upon which it resides, forms a primary barrier against production of pulmonary edema by ozone. However, this barrier, because of increase in its surface pressure, may be a primary cause of emphysema produced in animals by long-term exposure to ozone. Destruction of the surface-active material of the barrier should produce atelectasis and/or pulmonary edema as a result of increased surface tension.

Submitted on May 22, 1961
Reduction of cardiac work during venous blood perfusion of lower body
Authors: Wyman Milford G. , Weil Max H. , Blankenhorn David H.
Published: December 2017

A system of venoarterial perfusion was established in the adult dog, simulating that which normally exists in the mammalian fetus. Blood was passively drained from the inferior vena cava by way of both femoral veins, and continuously infused through a catheter inserted into the femoral artery in the abdominal aorta at its bifurcation. The system was adjusted so that approximately 50% of normal cardiac output was provided by the extracorporeal system. Indicator dilution and oxygen saturation measurements showed that the output of the heart was reduced by an amount approximately equal to the output of the pump. In the aorta, an abrupt change in oxygen saturation occurred 5 cm cephalad to the infusion catheter. A prominent continuous murmur was detected at this site. The pulse rate, peripheral resistance, and central blood volume were reduced. Cardiac output was decreased to 55% and stroke work to 50% of the control value. There was a slight fall of pH and pCO2 of arterial blood. This system of assisted circulation effectively reduces the work load on the heart, and may be a promising technique for the treatment of heart failure accompanied by venous congestion. However, these experiments indicate that it appears less promising for the treatment of hypotension and shock due to peripheral circulatory failure when venous return is deficient.

Submitted on April 24, 1961
Postsystolic myocardial augmentation: physiological considerations and technique
Authors: Watkins David H. , Duchesne E. Ronald
Published: December 2017

Technique and appropriate equipment are reported which remove blood from the circulation during cardiac systole, thereby reducing intraventricular systolic blood pressure and the work of systolic ejection. Blood is reinjected during ventricular diastole, so that the diastolic blood pressure and coronary blood flow are increased. An electronic circuit enables the phasing of the augmenting systole to be placed accurately in relationship to the QRS complex of the EKG. Application of the technique to experimental heart failure induced by norepinephrine and hemorrhage is illustrated. Cardiac dilatation, elevated end-diastolic pressures, and arterial hypotension are reversed by the use of this technique. In addition, it is possible to supply an unlimited quantity of oxygenated, banked, standard venous blood to the ascending aorta via intra-arterial cannulas. The technique which we have developed overcomes difficulties previously experienced by those who wished to withdraw blood during systole and reinject it during diastole. The size of the pump is adequate to change the blood pressure effectively; the timing of reinjection is such as to accomplish reinjection during the short period of ventricular diastole.

Submitted on May 8, 1961
Areas of dye-dilution curves sampled simultaneously from central and peripheral sites
Authors: Bassingthwaighte James B. , Edwards Anthony W. T. , Wood Earl H.
Published: December 2017

The assumption that the rate of blood flow past the sampling site is constant is basic to the Stewart-Hamilton estimation of cardiac output. Pulsatile flow might be expected to cause random and systematic errors. In this study dye-dilution curves were recorded simultaneously from two or three sites (pulmonary artery, aortic root, thoracic aorta, femoral artery) after injections of dye into the inferior vena cava, right ventricle, pulmonary artery, or left atrium of anesthetized dogs. The color of the indocyanine-protein complex formed after injection of the dye stabilized rapidly. Such stabilization is required for continuous photometric quantitation of dilution curves with juxtaposed injection and sampling sites. Areas of curves from the central circulation did not differ significantly from each other; they averaged 2.5% less than areas of curves recorded simultaneously from the femoral artery. Heart rate had no consistent influence. The large variability in estimates of cardiac output from curves recorded from the pulmonary artery after injection into the right ventricle was diminished with injection farther upstream.

Submitted on May 29, 1961
Absorption of various inert gases from subcutaneous gas pockets in rats
Authors: Piiper J. , Canfield R. E. , Rahn H.
Published: December 2017

A study was made of absorption of the inert gases, helium, argon, hydrogen, nitrogen, sulfur hexafluoride, nitrous oxide, and cyclopropane, from subcutaneous gas pockets in rats breathing oxygen. For interpretation of the data a method of analysis was devised which permitted distinction between perfusion and diffusion as factors limiting the absorption rate. Application of this method to the experimental data leads to the conclusion that both perfusion and diffusion limitation were effective in determining the absorption rates of the inert gases, diffusion limitation being the more important factor. The blood flow responsible for the uptake of inert gas from the gas pocket, and the thickness of the tissue layer between blood and pocket gas could be crudely estimated.

Submitted on October 9, 1961
Ventilation of terminal air units
Authors: Storey Winnifred F. , Staub Norman C.
Published: December 2017

We have used a rapid-freeze method to stop mechanical changes in the living lung in 0-10 sec and have adapted histological techniques to prepare thick three-dimensional sections from which diameters of alveoli and alveolar ducts were determined for lungs at two volumes, functional residual capacity and high lung volume, during positive-pressure ventilation. Diameters of both alveoli and ducts increase 30% from the lower to the higher lung volume. The calculated surface area of alveoli increases 70%. The volumes of alveoli and ducts were calculated to increase about twofold. The ventilation unit of the lung includes the alveolar ducts with their associated alveoli stemming from one respiratory bronchiole. The distribution of inspired gas to the respiratory surface of the lung is not determined by hundreds of millions of individual alveoli but by these larger ventilation units.

Submitted on September 5, 1961
Influence of body weight on energy expenditure
Authors: Malhotra M. S. , Ramaswamy S. S. , Ray S. N.
Published: December 2017

Energy expenditure in a group of 58 adult male subjects has been studied for marching, rifle drill, parade, physical training, bayonet fighting, cycling, sitting, and standing, using the method of indirect calorimetry. For all these tasks a linear relationship between energy expenditure and body weight has been established.

Submitted on September 5, 1961
Effect of oxygen inhalation on manual performance in the cold
Authors: MacCanon D. M. , Eitzman D. D. , Abbott J. E.
Published: December 2017

The effect of oxygen inhalation on block-stringing performance of 12 subjects was studied at hand temperatures of 32.7 C in a control room environment of 29 C and after cooling the hands to 16.0 C in a cold (5 C) environment. A similar slight but significant improvement in manual performance accompanied oxygen inhalation under both conditions. This is interpreted as indicating the existence of suboptimal neural and/or muscular activity during air breathing in both situations. If hand cooling had affected the same neural and/or muscular elements as oxygen, lowering activity even further from the optimal level, this should have exaggerated the O2 effect. In view of the absence of such a response, it would seem that hand cooling and oxygen influence different neural and/or muscular elements, and their effects on manual performance are not directly related.

Submitted on August 31, 1961
Evidence for local arteriovenous reflex in intestine
Authors: Hanson Kenneth M. , Johnson Paul C.
Published: December 2017

Studies were made on the hemodynamics of the isolated autoperfused dog intestine preparation. An attempt was made to explain the mechanism involved in the observed increase in venous resistance seen as the arterial pressure in the segment was reduced. This rise in venous resistance was reduced or abolished by sympatholytic agents (phentolamine and Dibenzyline) and by local anesthetics (tetracaine). When areas of intestine were surgically denervated and then subjected to hemodynamic studies 10–19 days later the venous resistance response was nearly or completely absent in all cases. The response was not significantly affected by the infusion of hexamethonium or dichloroisoproterenol or by changes in hematocrit ratio. It was concluded that the rise in venous resistance seen as arterial pressure is reduced is mediated by a local sympathetic axon reflex with the receptor on the arterial side of the circulation and the effector located on the venous side. The decrease in arterial resistance seen as arterial pressure is reduced (autoregulation) is also discussed. None of the drugs mentioned above or chronic denervation had any effect upon this phenomenon, strengthening the concept that it is the result of a myogenic response of the arterial vessels.

Submitted on November 6, 1961
Oxygen debt, lactate, pyruvate, and excess lactate after muscular work
Authors: Knuttgen Howard G.
Published: December 2017

The effect of activity of large muscles at different work intensities on oxygen debt and on lactate, pyruvate, and excess lactate during work and recovery has been studied. Data are presented for the more extensive testing program conducted on one research subject. Four series of experiments were conducted with the subject riding a Krogh bicycle ergometer at work rates of 300, 700, 1,100, and 1,600 kg-m/min. O2 debts were contracted at each of the work levels, but no appreciable rises in excess lactate and only small rises in total lactate were found at the lower two intensities. When a critical level of work (O2 uptake of 1.5 liters/min with an accompanying debt of 1.5 liters) was surpassed there was a rapid rise in O2 debt values which was parallel to rises in O2 equivalence values for both total lactate and excess lactate. At all work levels the O2 debt surpassed in quantity the O2 equivalents of the maximum increases in total lactate and, to an even greater extent, the O2 equivalents of excess lactate. This finding supports the theory of separate alactacid and lactacid portions of the O2 debt. No conclusions could be drawn concerning the rates or methods of payment of the two portions.

Submitted on October 23, 1961
Frequency-dependent compliance in the rabbit before and after sarin administration
Authors: Shephard Roy J.
Published: December 2017

Static and dynamic pulmonary compliance have been studied in 16 rabbits anesthetized with sodium pentobarbital, and ventilated by intermittent positive pressure pump. Functional residual volume increased at inflation rates of 56/min and above, and compliance decreased at rates greater than 60–70/min. These changes are interpreted as a distention of lung units with a long time constant. Following inhalation of sarin (isopropyl methylphosphonofluoridate) 12–120 μg/kg, the static compliance was slightly decreased, but there was no indication of an increase of gas trapping unless the dose of sarin was sufficient to cause death. Sarin accentuated the effects of increasing inflation rate by increasing the time constant of all lung units.

Submitted on October 20, 1961
Nerve conduction velocity and refractory period in peripheral vascular disease
Authors: Miglietta Osvaldo , Lowenthal Milton
Published: December 2017

The conduction velocity and the residual latency of the common peroneal nerve and the refractory period of the extensor digitorum brevis were measured in a group of patients with occlusive vascular disease of the lower extremity, and compared with those of a group of normal and elderly subjects. The results indicate that motor nerve and muscle are affected in peripheral arteriosclerosis. The conduction velocity showed a decrease of 16.9% for the patient group and of 6.7% for the elderly normal subjects when compared to the young group. The refractory period of the extensor digitorum brevis, after 10 min of provoked ischemia and 2/sec stimulation, increased 105.1% in the patient group, 17.8% in the young, and 28.9% in the elderly group. Correlations between the electrical responses and the state of muscle and nerve as influenced by chronic arteriopathy are discussed.

Submitted on October 26, 1961
Blood Pco2 and brain oxygenation at reduced ambient pressure
Authors: Pierce E. C. , Lambertsen C. J. , Strong M. J. , Alexander S. C. , Steele D.
Published: December 2017

Hyperventilation during breathing of 100% oxygen elevates the Po2 of alveolar gas by the same amount that it lowers its Pco2. Since the development of arterial hypocapnia causes cerebral vasoconstriction, brain oxygenation is drastically decreased even while arterial oxygenation is improved by hyperventilation. Administration of 30% CO2 with oxygen at an ambient pressure equivalent to that at 39,000-ft altitude prevented alkalemia and, in spite of hyperventilation, restored cerebral venous oxygenation to a level at least equivalent to that found when pure oxygen was breathed at rest at the same altitude. The respiratory minute volume during administration of CO2 with O2 was greater than when O2 alone was breathed at reduced ambient pressure. Since neither arterial Po2 nor cerebral venous Pco2 values differed in these two experimental situations, the respiratory stimulation may represent the quantitative demonstration in man of a respiratory effect of CO2 mediated by arterial chemoreceptor activation and unrelated to change in the level of central chemical stimulus.

Submitted on March 16, 1962
Uptake of O2 and CO by hemoglobin in sheep erythrocytes at various temperatures
Authors: Sirs John A.
Published: December 2017

Spectrophotometric observations were made with the stopped-flow method on the rate of uptake of CO and O2 by hemoglobin in intact sheep erythrocytes at temperatures between 5 and 37 C. Both rates were found to increase by roughly 1.5 for each 10 C rise. On the basis that diffusion through the cell membrane is involved, energies of activation for this process are calculated as 4,350 cal/mole for O2 and 5,900 cal/mole for CO. The addition of silver, copper, magnesium, and lead ions were found to significantly increase these rates

Submitted on September 21, 1961
Motor innervation and pattern of activity of cat diaphragm
Authors: Sant'Ambrogio G. , Frazier D. T. , Wilson M. F. , Agostoni E.
Published: December 2017

The segmental motor innervation of the costal and vertebral parts of the diaphragm of the cat has been studied by means of electromyography. The changes in electrical activity following successive sections of the cervical roots show that the costal region is innervated partly by C4 but mainly by C5, while the vertebral part is innervated partly by C5 and mainly by C6. After unilateral section of C4, C5, and C6 no diaphragmatic electrical activity remained on the ipsilateral hemidiaphragm. Section of the right phrenic nerve in the chest eliminates all electrical activity in the ipsilateral hemidiaphragm. Following a similar section of the left phrenic nerve, some rhythmic electrical discharge is still recorded from the corresponding hemidiaphragm. Only after section of the contralateral phrenic nerve does this residual activity disappear. Therefore, a few fibers must leave the left phrenic nerve and reach the diaphragm with the right phrenic nerve. Apparently these fibers cross the midline within the diaphragm and contribute to the motor supply of its left side. The pattern of the electrical activity of the costal and vertebral parts of the diaphragm is similar. Generally, no activity is present during the last part of expiration.

Submitted on July 9, 1962
Effect of alveolar hypoxia on zonal distribution of pulmonary blood flow
Authors: Fowler K. T. , Read John
Published: December 2017

Redistribution of pulmonary blood flow was studied by means of the cardiogenic oscillations of expired gas tensions in six normal subjects after induction of alveolar hypoxia (13.5% O2 inspired). In three subjects the upper zones of the lungs were found to receive a considerably greater proportion of total pulmonary blood flow during hypoxia in both vertical and horizontal postures. Two subjects showed no redistribution in either position. The response of one subject was intermediate between these two groups. It is concluded that in some subjects there is no pulmonary vascular response to alveolar hypoxia, whereas in others there is a response consisting of preferential lower-zone vasoconstriction of greater or lesser magnitude. Earlier data on the effects of hypoxia on the pulmonary circulation are shown to be consistent with the operation of this mechanism.

Submitted on July 16, 1962
Anticoagulant effects of concentrated cephalin in the thromboplastin generation test
Authors: Coffield Kenneth J. , Cocanour Mary Ann
Published: December 2017

Concentrated suspensions of phospholipid (cephalin) inhibit thromboplastin generation as a result of adsorption or inactivation of factors V and VIII by the phospholipid. Such inhibition can be overcome by increasing the concentration of plasma and serum reagents, or allowing product I to form prior to the addition of phospholipid. Adsorption of plasma reagents with washed sedimented cephalin demonstrates directly the depletion of factors V and VIII.

Submitted on July 5, 1962
Different effects of hypothermia on two syndromes of positive acceleration
Authors: Stiehm E. R.
Published: December 2017

The tolerance to high positive (headward) acceleration at levels of 20–80 G was studied in normal and hypothermic rats. Normal rats have a mean survival time of 680 sec at 20 G, but this decreases to 105 sec at 30 G. Only slight decreases are noted at higher G, suggesting that 30 G is the point at which cerebral circulation is interrupted. Hypothermia at 22.5 C decreases acceleration tolerance at 20 G, but markedly increases acceleration tolerance at 30 G and above. At 40 G this effect is maximal, and the mean survival time for hypothermic rats is 252 sec, compared to 75 sec for controls, an increase of 236%. These different effects of hypothermia on acceleration tolerance suggest that there are two distinct syndromes of physiologic failure during positive acceleration. One is a “cardiac” syndrome, occurring at 20 G and below, characterized by partial maintenance of cerebral circulation until cardiac failure ensues, and the other is a “cerebral” syndrome, occurring at 30 G and above, characterized by immediate interruption of cerebral circulation and respiratory paralysis.

Submitted on May 17, 1962
Alveolar gas exchange during breath-hold diving
Authors: Lanphier E. H. , Rahn H.
Published: December 2017

Use of a recompression chamber permitted simulation of breath-hold dives to 33 ft of sea water (2 atm abs). Four normal subjects made such dives during rest and mild exertion while delivering alveolar gas samples at frequent intervals by a partial-rebreathing procedure. The course of alveolar gas exchange differed greatly from that in ordinary breath holding. Oxygen uptake remained at near normal levels until ascent owing to the maintenance of alveolar Po2 by increased ambient pressure. Reversal of CO2 transfer occurred during descent, and little CO2 moved in the normal direction until ascent. Greater uptake of oxygen and retention of CO2 in the body led to lower final values of both alveolar Po2 and Pco2 than in comparable breath holding at the surface. Hyperventilation made possible longer dives with harder work, and in these the Po2 reached very low values on ascent. One subject showed a final Po2 of 24 mm Hg with evidence of reversed O2 transfer. Acute hypoxia on ascent is a likely cause of drowning in breath-hold diving.

Submitted on October 17, 1962
Partial marrow shielding and total-body irradiation
Authors: Noyes W. D. , Finch C. A. , Wasserman H. , Glickman K.
Published: December 2017

The effects of shielding one femur on bone marrow morphology and function were studied in rats receiving total-body irradiation. Animals were exposed to 550 r from a Co60 source. Shielding consisted of 100 mm of lead, reducing exposure to one femur to 16 r. Marrow cell counts, radioiron localization in femurs, plasma iron turnover, red cell radioiron utilization, and peripheral cell counts were observed. Phlebotomy in some animals served as a functional stress. There was no observed morphological change in shielded marrow despite marked depopulation of nucleated cells in heavily irradiated marrow. In phlebotomized shielded animals, the rate of hemoglobin synthesis was nearly half that of unirradiated controls although retarded by several days whereas in unshielded animals, hemoglobin synthesis was further delayed and less than a third of control values. Initially the erythropoietic function resides primarily in shielded marrow as evidenced by radioiron localization and marrow cell counts with no evidence of indirect depression. Cellular repopulation appears more rapidly in partially shielded animals and compares favorably with the effectiveness of marrow transfusion.

Submitted on December 5, 1962
Reflex effects of lung inflation on tracheal volume
Authors: Widdicombe J. G. , Nadel J. A.
Published: December 2017

Transient lung inflation increased the volume of a bypassed tracheal segment in anesthetized dogs, whether spontaneously breathing or paralyzed and artificially ventilated. The degree of dilation during inflation varied with the state of “tone” of the tracheal muscle and with the inflation volume. Pulmonary denervation caused maintained constriction of the trachea and blocked the dilation during lung inflation. Cooling the cervical vagus nerves to between 7 and 12 C had the same effect. Both of these procedures blocked the Hering-Breuer inflation reflex, but the trachea still constricted following carotid body chemoreceptor stimulation by KCN. In paralyzed dogs, injection of veratrine into the right heart caused tracheal dilation, presumably by stimulating pulmonary stretch receptors. Left heart injection dilated the trachea much less. The former effect was abolished by pulmonary denervation. In anesthetized spontaneously breathing dogs carotid body chemoreceptor stimulation by KCN constricted the trachea; this was followed by increased ventilation and secondary tracheal dilation. Pulmonary denervation or muscular paralysis and artificial ventilation prevented the secondary dilation. These results establish the reflex nature of tracheal dilation during transient lung inflation and suggest that Hering-Breuer stretch receptors are the responsible end organs.

Submitted on January 15, 1963
Effect of environmental temperatures on retention of cesium 137 by mice
Authors: Furchner J. E. , Richmond C. R.
Published: December 2017

Three groups of 12 mice each were maintained at environmental temperatures of 34, 22, and 5 C for a period of about 7 weeks after an intraperitoneal injection of Cs137. Periodic assay of the activity in the whole body and excreta showed that as environmental temperature decreases the excretion of Cs137 increases, probably as a result of the increased metabolic rates associated with low temperatures.

Submitted on November 19, 1962
Specific heat of canine blood
Authors: Epstein Wolfgang , Visscher Maurice B. , Stish Richard , Ballin Henry
Published: December 2017

The relationship of specific heat of canine blood to hematocrit and density was determined at 37.46 C. Density is seen to give the better index of this property. The equation describing the relationship is: specific heat = 0.998 – 2.30 (specific gravity – 1).

Submitted on October 6, 1961
Use of an electromagnetic flowmeter for urine flow measurements
Authors: Cardus D. , Quesada E. M. , Scott F. B.
Published: December 2017

The measurement of instantaneous urinary flow has been a technical problem in studies of the dynamics of the urinary bladder. In this investigation, the adaptation of an electromagnetic flowmeter has proved to be useful in measuring the instantaneous flow of urine. The probe of this instrument was either connected directly to the subject by means of an adapter or it was placed in series with a funnel system which did not require contiguity with the subject. It is concluded that both the direct and the funnel procedures are suitable for the monitoring of instantaneous urine flow, the latter being particularly practical in the determination of peak flows during micturition.

Submitted on September 5, 1962
Learning in hypothermic rats
Authors: Panuska J. A. , Popovic Vojin
Published: December 2017

Inexperienced shaved adult white rats cooled to a colonic temperature of 18.5 C and then rewarmed to 26.0 C, were placed at an ambient temperature of 2.0 C with the possibility of using a lever-activated heat reinforcement apparatus. Their body temperatures leveled at 29 C; and during the next 40–80 min the rats either learned to press the lever systematically for external heat and thereby rewarmed themselves to euthermia, or they drifted into deeper hypothermia leading to death. Activity records and visual observations indicate that after an average of 48 min and at a body temperature of 29.6 C (28.5–30.2 C), out of a group of 14 rats 12 learned this technique necessary for their survival. All 12 rats reached euthermia and continued to use the lever as long as they remained in the experimental situation. It is concluded that learning is possible even at a low body temperature of 29.6 C.

performance; heat reinforcement; temperature regulation; body temperature; environmental temperature; operant behavior; survival studies; motivation; physiology of learning; cold physiology

Submitted on March 7, 1963
Body temperature regulation in mice resuscitated from deep hypothermia
Authors: Sudak Frederick N. , Essman Walter B. , Shen E. Mei
Published: December 2017

Body temperature regulation was studied in mice following resuscitation from deep hypothermia induced by means of the closed-vessel cooling technique. Forty per cent of the animals cooled to and maintained at a colonic temperature below 5 C (lowest mean colonic temperature = 1.5 C) failed to demonstrate body temperature regulation when exposed to 2 C air for 30 min at 7-day intervals for a period of 70 days following resuscitation. Mice cooled to 5 C and immediately resuscitated showed a temporary loss in body temperature regulation. Loss of body temperature control did not occur in any of the control groups. Histological examination of midbrain sections taken from animals in each group showed pathological changes. There was no correlation between body temperature regulation and brain pathology. Mice resuscitated from sustained deep hypothermia showed impaired body temperature regulation upon heat exposure (39 C for 60 min) 7 days later. These data indicate that mice subjected to prolonged deep hypothermia induced by means of the closed-vessel cooling technique show poikilothermic responses following recovery. Furthermore, permanent loss of body temperature regulation upon cold exposure may result from this procedure.

Note:

With the Technical Assistance of D. Pennec and D. Glaubinger

poikilothermic responses; resuscitation of hypothermic mice

Submitted on February 21, 1963
Effect of oxygen inhalation on cold thresholds
Authors: MacCanon D. M. , Resnik J.
Published: December 2017

The effect of oxygen inhalation on cutaneous thresholds for cold sensation was determined by exposing a 50-cm2 area on the chest to a radiant cold source of variable intensity for 2-sec intervals in 11 healthy 23- to 26-yr-old nude subjects at two ambient temperatures. Oxygen breathing produced a similar significant increase in cold thresholds in both cool (22.4–26.5 C) and warm (36.6–39.3 C) environments. Observations at warm ambient temperatures substantiate the oxygen effect independent of suspected reflex vasoconstriction in the cool environment.

environmental temperature

Submitted on March 18, 1963
Discrepancy between heart rate and oxygen consumption during work in the warmth
Authors: Brouha Lucien , Maxfield Mary E. , Smith Paul E. , Stopps Gordon J.
Published: December 2017

These experiments compare the usefulness of oxygen consumption and heart rate as indicators of the strain produced by repetitive work in various environments. When the length of the rest periods was determined by the time for oxygen consumption to return to its resting level, a steady state of heart rate and oxygen consumption was achieved in a comfortable environment. In warm surroundings, oxygen consumption reached again a steady state but the heart rate increased during repetitive work cycles. When the duration of the rest periods was arbitrarily fixed, both oxygen consumption and heart rate reached constant steady states in repeated work cycles when the environmental stress was light. When it was severe, oxygen consumption remained at the same average value from cycle to cycle and failed to indicate the presence of accumulated strain which was revealed by increasing heart rates.

repetitive work; warm environment; female humans

Submitted on July 13, 1961
Control mechanisms in blood fluidity: role of adenosine triphosphate
Authors: Pilgeram L. O. , Loegering D. A.
Published: December 2017

A possible role for cellular energy metabolism in the control of the blood clotting mechanism has been shown. High-energy phosphate was found to strongly inhibit the recalcification time of plasma prepared with siliconized or glass surfaces. The nucleotide, adenosine triphosphate, in crystalline form and chromatographically pure, will inhibit or completely prevent coagulation in vitro. Reactivity is based primarily on the high-energy phosphate linkage and secondarily upon the nucleoside, adenosine. The principal site of action for ATP is on an unidentified precursor of thromboplastin. Available evidence indicates an important role for energy metabolism in the cellular mechanisms which effect a control over thromboplastin generation and its possible thrombotic and arteriosclerotic sequelae.

cellular control mechanisms; blood fluidity; thrombosis arteriosclerosis; aging

Submitted on July 1, 1963
Various hormone changes during simulated space stresses in the monkey
Authors: Winters W. D.
Published: December 2017

Experiments were undertaken to study the alteration in urinary excretion of 17-ketogenic steroid, catecholamine, and urine output during several simulated space stresses, i.e., centrifugation, vibration, and isolation with restraint in the monkey. The results indicated a variability of responses depending on the type and degree of stress. Reduction in urine volume was observed in all instances. A fall in steroid and slight elevation in catecholamine excretion was observed following vibration and centrifugation. The centrifugation appeared to be slightly more stressful. Isolation with restraint appears to be a severe stress to the animals as demonstrated by a marked elevation of amine, and a marked reduction in both urine output and steroid excretion.

daily urine volume; catecholamine excretion; 17-keto-genic steroid excretion; acceleration; centrifugation; isolation and restraint

Submitted on September 24, 1962
Insensible weight loss of clothed resting subjects in comfort zone temperatures
Authors: Hall J. F. , Klemm F. K.
Published: December 2017

Insensible weight loss rates of clothed sitting subjects exposed to various temperatures in the range (22–32 C) were measured with a precision system in which weight losses are balanced automatically, displayed on a digital voltmeter, and printed on paper as a function of time. Accuracy of the scale is ± 5 g. Thirty-nine experiments were conducted on ten male subjects wearing light clothing (0.9 clo), exposed 2 hr at 22, 23.9, 26.7, 29.4, and 32.2 C and constant (10 mm Hg) ambient water-vapor pressure. First hour was for equilibration. Mean skin and body temperatures were measured with 17 thermistors and rectal thermistor, respectively. At ambient temperatures 22–26.7 C insensible loss rate increased slightly (21–26.5 g/m2 hr). From 26.7 to 32.2 C, however, increase is marked (26.5–64 g/m2 hr) with an abrupt rate increase at 26.7 C ambient and at a mean skin temperature of 34.6 C. Importance of ambient air temperature as a control factor in total water loss of subjects in closed space systems is shown.

insensible perspiration; body water deficit; skin water loss; closed space systems

Submitted on April 4, 1963
Catecholamine excretion during heat deacclimatization
Authors: Hale Henry B. , Williams Edgar W. , Ellis James P.
Published: December 2017

Sympathoadrenal activity was appraised in ten heat-acclimatized men over a 10-week period, beginning in late summer and ending in autumn. Two overnight urine samples per subject per week were analyzed for norepinephrine, epinephrine, creatinine, and urea. Evidence of relatively high sympathoadrenal activity was obtained in late summer, since a progressive decline appeared in autumn. The catecholamines were shown to relate either to weekly mean maximum temperature or to weekly mean solar radiation. Catecholamine excretion also tended to vary inversely with urea excretion.

epinephrine excretion; norepinephrine excretion; heat acclimatization; sympathoadrenal activity in hot climate

Submitted on February 25, 1963
Pulmonary function during norepinephrine-induced calorigenesis in cold-acclimatized rats
Authors: Evonuk Eugene , Hannon John P.
Published: December 2017

The effects of cold acclimatization on pulmonary function during norepinephrine-induced calorigenesis were studied. Norepinephrine resulted in a marked increase (85%) in the pulmonary minute volume in both the warm- and cold-acclimatized rats. This increase in the warm-acclimatized rats was accomplished entirely by increasing the respiratory rate, whereas in the cold-acclimatized rats, the increase in pulmonary minute volume was achieved for the most part by increasing the tidal volume with a slight increase in respiratory rate. Cold acclimatization was associated with a greater “efficiency of oxygen extraction” before, during, and after the infusion of norepinephrine.

pulmonary minute volume; respiratory rate; oxygen extraction

Submitted on December 6, 1962
Sweat sodium content and flow rate in cystic fibrosis of the pancreas
Authors: Sibinga Maarten S. , Barbero Giulio J.
Published: December 2017

Sweat of healthy children and patients with cystic fibrosis was compared following stimulation with methacholine by iontophoresis and by intradermal injection. Sweat samples were collected at 10 min and subsequent 20-min intervals. With injection of methacholine higher initial secretory rates and sodium concentrations were obtained and a steeper decline of these parameters followed, while iontophoresis resulted in a more sustained sweating response. Sodium concentrations in sweat were from 3.45 to 6.75 times elevated in cystic fibrosis. A definite relation of Na content and secretory rate was established for normal children as well as for patients with cystic fibrosis.

children; methacholine

Submitted on November 16, 1962
Some biochemical and physiological features of normal monkeys (Macaca radiata)
Authors: Srikantia S. G. , Gopalan C.
Published: December 2017

Determinations of body-fluid spaces with antipyrine for total-body water and sodium thiocyanate for extracellular fluid volume, hematological indices, and several serum constituents in about 500 Macaca radiata monkeys revealed that most of the values obtained were very similar to values obtained in man.

body fluid spaces; hematology

Submitted on April 22, 1963
The photodermoplanimeter
Authors: Halliday E. C. , Hugo T. J.
Published: December 2017

A description is given of an instrument which measures the radiation area of the human body. An isotropic flux of light is produced in a large integrating vessel and when a human subject whose skin has been suitably blackened enters the vessel, the light intensity at a window in the wall of the vessel is decreased. A photometric measurement of this decrease enables the effective area of the surface of the skin of the subject to be measured with an accuracy of better than 1%. The instrument enables measurements to be made on large numbers of subjects rapidly and reliably.

human body surface; radiation area; photometric measurement

Submitted on April 5, 1963