bluuebunny/crossref_metadata_2025 huggingface dataset:
Physiological reactions to cold of Caucasian females
Authors: Wyndham C. H. , Morrison J. F. , Williams C. G. , Bredell G. A. G. , Peter J. , Von Rahden M. J. E. , Holdsworth L. D. , Van Graan C. H. , Van Rensburg A. J. , Munro A.
Published: December 2017

The physiological reactions to cold of nine female Caucasians were examined and compared with the reactions of a sample of male Caucasians. The experiment was conducted in the climatic chamber of the Applied Physiology Laboratory at air temperatures of 27 and 5 C, with a wind velocity of 80–100 ft/min. The sample of nine did not provide for intermediate temperature studies. The metabolic rates of the females were lower than those of the males, at both 27 and 5 C, but when expressed per square meter no differences were found. Finger and toe and rectal temperatures were the same for both sexes at 5 C, but the average female finger temperature was lower than that of the males at 27 C. The average female skin temperature was 2 C lower than that of the males. This indicates a greater subcutaneous insulation for females and this is confirmed by skinifold measurements. Both Caucasian sexes therefore display an increase in rectal temperature with fall in air temperature, which contrasts markedly with the Bantu and Bushman, both of whom show a decrease in rectal temperatures.

Caucasian females and cold; cold responses of Caucasian females

Submitted on September 17, 1963
Hyperbaric oxygen and persistence of vision in retinal ischemia
Authors: Carlisle R. , Lanphier E. H. , Rahn H.
Published: December 2017

When retinal ischemia is produced by elevating the intraocular tension, normal vision persists for about 4 sec in healthy subjects breathing air at atmospheric pressure. Persistence times were determined at alveolar oxygen pressures up to 4 atm abs (3,000 mm Hg), obtained by oxygen breathing in a high-pressure chamber. Below an alveolar Po2 of 2 atm the rise in persistence time is relatively small. Above that level the time increases in direct proportion to the increase in alveolar Po2 and may exceed 50 sec at 4 atm. The rise of persistence time follows a pattern similar to that of computed blood oxygen pressure assuming an oxygen extraction of about 3 vol%.

high pressure; blood oxygen tension; tissue oxygenation; intraocular tension; retinal circulation; visual blackout

Submitted on February 7, 1964
Ventilatory response to intermittent inspired carbon dioxide
Authors: Dutton R. E. , Chernick V. , Moses H. , Bromberger-Barnea B. , Permutt S. , Riley R. L.
Published: December 2017

The hypothesis that cyclic variation of CO2 tension of the arterial blood (PaCOCO2) about its mean produces an additional stimulus to ventilation was tested in the dog. Oscillations of alveolar carbon dioxide tension were produced by the intermittent administration of 20% CO2 for 1 breath every 7–12 breaths. The increment in ventilation per mm Hg rise in mean PaCOCO2 during the intermittent administration of 20% CO2 was compared to that during continuous administration of 3% CO2 in nine adult dogs anesthesized with sodium pentobarbital. Thirteen experiments with oscillating CO2 and eighteen with steady CO2 were performed. In all except one animal the increase in ventilation per mm Hg change in mean PaCOCO2 was greater during intermittent CO2 than during steady CO2. In three experiments intermittent administration of CO2 caused a ventilatory response sufficient to lower the mean PaCOCO2 below control values. The increment in total ventilation per mm Hg rise in arterial carbon dioxide tension for steady CO2 breathing was 0.58 liters/min per mm Hg and for intermittent CO2 was 2.00 liters/min per mm Hg. These findings support the concept that chemoreceptors are stimulated by oscillations of PaCOCO2 as well as by the mean level of PaCOCO2. The oscillatory stimulus appears not to be related to the amplitude of the oscillation or to the peak Pco2 attained, but rather to the rate of increase of arterial Pco2.

respiration control; ventilation

Submitted on October 17, 1963
Experimental evaluation of Weir's formula for estimating metabolic rate in man
Authors: Turell David J. , Alexander James K.
Published: December 2017

One hundred and thirty determinations of metabolic rate at rest and during both steady and unsteady states of exercise have been made in human subjects. Calculation of the caloric expenditure by means of Weir's formula, by the Zuntz-Schumburg-Lusk table, and by the Cathcart-Cuthbertson table has revealed mean differences among these methods of less than 1%. The Weir formula may be utilized for all practical purposes in lieu of the tables, permitting elimination of the RQ correction factor, and thus simplifying the estimation of the energy cost of activity

caloric expenditure; determination of metabolism; formula for caloric expenditure; steady-state, caloric measurement; unsteady-state, caloric measurement

Submitted on December 16, 1963
Chronic bile duct cannulation in the dog
Authors: Marshall Richard W. , Moreno Oscar M. , Brodie David A.
Published: December 2017

Chronic bile duct cannulation for periods of up to 6 months was obtained by catheterizing the bile duct in cholecystectomized dogs with plastic tubing without ligation of the bile duct. Between experiments, the bile drained into the intestine and during experiments, the plastic tube was removed through a chronic duodenal cannula. Similar bile volumes were obtained over a 24-hr collection period whether or not the bile was reintroduced into the intestine.

bile collection in chronic dogs; 24-hr bile volume

Submitted on February 28, 1964
Catheter-tip flowmeter for coronary arterial flow in closed-chest dogs
Authors: Pieper Heinz P.
Published: December 2017

The design of a catheter-tip flowmeter for the measurement of coronary arterial blood flow in closed-chest dogs is presented. The miniaturized flowmeter is attached to the tip of a rigid catheter which is inserted through the right carotid artery. The flowmeter is placed in the ascending aorta where it measures the inflow into the left coronary artery. Performance tests show the reliability of the instrument for the measurement of pulsatile flow.

pulsatile flow

Submitted on February 3, 1964
Effect of respiratory gases on compliance of intrapulmonary arteries and veins
Authors: Salem E. S. , Permutt S. , Riley R. L. , Johnson J. W. C.
Published: December 2017

Submitted 16 October 1964

A method was developed that permitted changes in the pressure-volume characteristics of large intrapulmonary vessels occurring with changes in the composition of alveolar gas to be studied in excised lungs. The capillary bed was emptied by keeping intravascular pressure well below alveolar pressure, and the relationship between changes in the volume of the pulmonary arteries or veins with changes in transpulmonary pressure was measured. The volume of the arteries and veins always decreased with a decrease in transpulmonary pressure, but when the alveoli contained carbon dioxide, the decrease in vascular volume was less, for the same decrease in transpulmonary pressure, than when the alveoli contained oxygen or nitrogen without carbon dioxide. This change with carbon dioxide was probably due to a decrease in the compliance of the larger intrapulmonary arteries and veins. Since there was no pathway for carbon dioxide to enter these vessels except by diffusion from the alveoli, it is concluded that carbon dioxide can act directly on the intrapulmonary arteries and veins to reduce their compliance, but it is not known whether this effect has physiological significance. No effect on the large pulmonary vessels was found with variations in alveolar concentrations of oxygen.

blood vesselsblood volumecarbon dioxidediffusionlungspulmonary circulation
Acid-base constants and temperature coefficients for cerebrospinal fluid
Authors: Mitchell Robert A. , Herbert Dorothy A. , Carman Charles T.
Published: December 2017

The solubility of CO2 in human cerebrospinal fluid (CSF) is 0.0312 mmole/liter·mm Hg at 38 C. The first dissociation constant (pK1') of carbonic acid at 38 C is 6.130 at pH 7.30 and varies inversely with pH and temperature. At pH 7.30 DeltapK1'/ DeltapH is -0.050 and DeltapK1'/DeltaT is-0.0029 U/°C. pH of CSF varies inversely with temperature over the range of pH from 6.9 to 7.7. DeltapH/DeltaT is -0.0037 U/°C. The temperature correction for CSF Pco2 is expressed Pco2T1/Pco2T2 = 10 f(T1–T2) At pH 7.30, f is 0.0110. The effect of varying Pco2 on pH in vitro at 38°C, expressed as Delta log Pco2/DeltapH, is 1.063 ± 0.022.

first dissociation constant; CO2 solubility; CSF buffering

Submitted on February 20, 1964
A simple method for measuring total respiratory compliance: normal values for males
Authors: Cherniack R. M. , Brown E.
Published: December 2017

A simple method for measuring the compliance of the total respiratory system utilizing a recording spirometer and lead weights is described. The method was reproducible and compared well with an established body box technique. The compliance of the total respiratory system was determined in 70 normal male subjects between the ages of 4 and 70. The total respiratory compliance was influenced by age and appeared to rise during the first 3 decades and fall in subsequent decades. The compliance was also related to the height, body surface area, total lung capacity, and vital capacity, the best correlation being with vital capacity. The change in compliance with age did not appear to be related to change in body size. When corrected for the total capacity of the lungs, there was a gradual decrease in total compliance with aging. It is suggested that this is due to an increase in resistance of the “chest wall.”

compliance and age and size; compliance and lung volumes

Submitted on April 1, 1964
Lung diffusing capacity: rebreathing method, applicability in nonuniform ventilation
Authors: S⊘lvsteen P.
Published: December 2017

We have calculated how the carbon monoxide concentration changes when subjects with different distributions of ventilation and lung diffusing capacity (Dl) respire in a small bag. The curve [loge CO concentration in the bag] versus [time] will sooner or later appear as a straight line. Dl is calculated from the slope of the rectilinear section of the curve and from lung and bag volume. If the curve becomes rectilinear within the period considered, Dl is calculated too low. In some cases the curve will not be rectilinear until more than 45 sec have passed, but will appear to be rectilinear during the period from 30 to 45 sec. If such an experiment is discontinued when 45 sec (the usual duration of experiment) have passed, Dl can be calculated at too high, at correct, or at too low values.

nonuniform distribution of lung diffusing capacity

Submitted on February 18, 1964
Regional distribution of intraesophageal pressure in normal and emphysematous subjects
Authors: Schilder Donald P. , Roberts Albert , Greenfield Joseph C. , Fry Donald L.
Published: December 2017

If sufficiently large pressure differences were to develop between the pulmonary air spaces of one region and another during ventilatory efforts, then it is possible that septal ruptures such as seen in emphysema might result. It was the purpose of this study to explore this possibility. Intraoral airway pressure and intraesophageal pressure at three esophageal levels were measured simultaneously and continuously in 5 normal subjects and 10 patients with varying degrees of chronic obstructive pulmonary disease. No significant regional pressure difference developed in the segments of lung adjacent to the esophagus in any subject during static respiratory efforts against a closed valve or during strenuous dynamic respiration with maximum voluntary ventilation. These results are negative with respect to the pathogenesis of emphysema since large pressure differences along the lung surface were not demonstrated. The remarkable similarity of intraoral airway pressure and the intraesophageal pressures during the static part of the study is further evidence validating the intraesophageal approach to the measurement of intrathoracic pressure in diseased as well as normal subjects.

intrathoracic pressure; lung stress mechanics of ventilation; pathogenesis of emphysema

Submitted on June 9, 1964
Pulmonary circulation in acclimatized man at high altitude
Authors: Hultgren H. N. , Kelly J. , Miller H.
Published: December 2017

Cardiac catheterization studies have been carried out in 30 acclimatized adults at an altitude of 12,3000 ft in the Peruvian Andes. Mean pulmonary artery pressure was 22 mm. Hg (range 14-31 mm Hg) compared to 15 mm Hg (range 11-17 mm Hg) observed in sea-level subjects. The pulmonary artery wedge pressure was normal and calculated pulmonary arteriolar resistance was increased by 180% over sea-level values. The arteriovenous oxygen content difference and oxygen consumption were slightly greater at high altitude, but the cardiac output was normal. There was no relationship between hematocrit and pulmonary artery pressure or resistance, suggesting that in the high-altitude resident, blood viscosity in a hematocrit range of 40-78% does not significantly affect resistance to blood flow. Nine subjects studied at 14,200 ft had the same mean pulmonary artery pressure (22 mm Hg, range 17-32 mm Hg) as the larger group at 12,300 ft.

pulmonary artery pressure

Submitted on May 8, 1964
Oral/rectal temperature differences during work and heat stress
Authors: Strydom N. B. , Wyndham C. H. , Williams C. G. , Morrison J. F. , Bredell G. A. G. , Joffe A.
Published: December 2017

Fifty-two groups of about 20 men each were exposed for 5 hr to various combinations of work rate, environmental temperature, and wind velocity. Hourly observations were made of oxygen intake and oral and rectal temperatures. Oral/rectal temperature differences increased significantly with time only under those conditions where steady-state responses were not achieved. Increasing wind velocity from 50 to 400 cm/sec, raising air temperatures from 27 to 36 C, and combinations of these factors had no significant influence on the difference between the recorded temperatures. The main contributing factor to oral/rectal temperature difference is work rate. Increasing energy consumption from 2.5 to 9.0 Cal/min resulted in a rectilinear increase in average difference from 0.5 to 1.1 C. A warning is expressed against the indiscriminate use of oral temperatures in work and heat studies

influence of work and heat stress on oral/rectal temperature differences; oral versus rectal temperatures

Submitted on May 18, 1964
Effects of exercise in the cold on blood clotting and platelets
Authors: Finkel Annette , Cumming G. R.
Published: December 2017

The tendency to blood clotting as measured by Lee-White clotting time (CT), partial thromboplastin time (PTT), and platelet adhesiveness (PAC) was studied in 10 normal subjects before and after a standardized bicycle exercise done at 25 C inside and at an average temperature of -20 C outside. Inside exercise caused a shortening of CT from 674 to 465 sec, of PTT from 88 to 78 sec, and PAC increased from 65,000/mm3 to 185,000/mm3; P < .05 for all tests, suggesting an increased tendency to blood clotting. In contrast, exercise done in the cold produced no significant changes in these parameters. Heart rate, rectal temperature, and changes in plasma proteins were similar for both types of exercise.

platelet adhesiveness; clotting time

Submitted on July 20, 1964
Dissimilar distribution of calcium isotopes in blood serum and urine
Authors: Briscoe Anne M. , Ragan Charles
Published: December 2017

A study of the distribution of tracer doses of radiocalcium 47 in blood serum and urine for 5 days after its intravenous administration to human subjects is presented. Using atomic absorption spectroscopy to determine total calcium, the specific activity of the urinary calcium 47 was found to be higher than that of the contemporary serum during the first 96 hr. Calculated renal clearance of calcium 47 was higher than that of calcium 40 during this time interval. Equilibrium dialysis of the serum resulted in a decrease in its calcium 47 specific activity, an effect which was enhanced by increasing the volume of dialyzing fluid. Fractions of serum collected from a Sephadex column contained unequal proportions of the two isotopes. The nonultrafiltrable calcium fractions appear to be heterogenous, and of different dissociation characteristics. At least one is not readily exchangeable with the diffusible calcium.

renal clearance of calcium isotopes; metabolism of radiocalcium 47; distribution of calcium 47 in blood serum fractions; dialyzable serum calcium 47; serum calcium 47 specific activity; urine calcium 47 specific activity; nondialyzable serum calcium 47; calcium in Sephadex serum fractions

Submitted on July 24, 1964
Relations between sweating, cutaneous blood flow, and body temperature in work
Authors: Robinson S. , Meyer F. R. , Newton J. L. , Ts'Ao C. H. , Holgersen L. O.
Published: December 2017

Men worked on a treadmill for periods of 5, 5, 10, 10, 10 and 10 min, stopping for 2 min between work periods to be weighed. Finger and mean skin temperatures decreased at the beginning of work (10 mets). When room temperature was 25 C vasodilation occurred in the finger in the third work period as gastrocnemius muscle and femoral vein temperatures reached maximal values. Temperatures of skin and saphenous vein blood rose rapidly as the men reclined during the rest periods and decreased when work was resumed, coinciding with changes of femoral temperature in the opposite directions. These rapid shifts in temperature indicate that during the rest periods the proportion of blood coming from the skin into the trunk of the femoral was greater than during the work periods. The onset of sweating, the rate of its increase in the early stages of these work experiments, and its decline in recovery more nearly paralleled corresponding changes in femoral temperature than any of the other temperatures measured.

exercise; femoral vein temperature; temperature regulation; saphenous vein temperature; skin temperature

Submitted on October 5, 1964
Body composition and atherosclerosis in cocks after long exposure to heat and cold
Authors: Fisher Hans , Griminger Paul , Weiss H. S.
Published: December 2017

Three groups of adult cocks were exposed respectively to 2, 21, and 32 C temperatures for a 15-month experimental period. Food consumption, body weight, body composition, feather composition and weight, atherosclerosis and fatty acid composition of plasma, liver and depot fat were studied. It was found that with the use of a pelleted diet the cold-exposed cocks maintained the same body weight as the control group (21 C). The heat-exposed birds were lighter in weight than either controls or cold-exposed and had significantly less body fat and water. Severity of atherosclerosis was not affected in the cold-exposed cocks, despite greatly increased caloric intake. The liver fat of the cold-exposed cocks was significantly higher in di- and hexaenoic acids than that of the controls or heat-exposed birds. The depot fat of heat-exposed birds was lower in monoenoic and higher in dienoic acid than that of controls or cold-exposed birds. The cold-exposed cocks also had significantly more feathers and feather lipid than the other two groups.

fatty acid composition; depot fat temperature; feathers

Submitted on November 23, 1964
Simultaneous uptake of N2O and cyclopropane in man as a test of compartment model
Authors: Rackow Herbert , Salanitre Ernest , Epstein Robert M. , Wolf Gerald L. , Perl William
Published: December 2017

An experiment involving simultaneous pulmonary uptake of nitrous oxide and cyclopropane is analyzed for compatibility with the perfusion-limited multicompartment model of inert gas uptake. These test gases have approximately equal solubilities in body watery tissues (blood, muscle, viscera, etc.) but an approximately 1-to-8 ratio of solubility in fat. Therefore, the measured difference in time course of pulmonary uptake provides a sensitive test of the mechanism of adipose tissue uptake of these gases. The experimental data could not be accounted for by the model, assuming plausible compartment parameters, or by using derived compartment parameters. Expansions of the model to account for the discrepancy are suggested.

gas uptake in body; fat-soluble gas uptake; multiple gas uptake; fat perfusion; adipose tissue perfusion; blood flow to fat; perfusion of fat; inert gas kinetics; tissue gas exchanges

Submitted on February 3, 1964
Effects of unilateral thoracic irradiation on lung function
Authors: Teates Charles D.
Published: December 2017

Five dogs were irradiated in one hemithorax with 4,500 R midlung dose over 23 —27 days. Function of each lung was studied prior to irradiation and at frequent intervals up to 207 days after irradiation. A nonspecific reduction in function of the irradiated lung was reflected on all indices. The reduction in diffusion capacity apparently resulted from factors other than alveolar-capillary block. Pulmonary function did not improve during the period studied. Pathologic, radiologic, and physiologic studies showed considerable variation of damage from one animal to another and within the same lung, but each subject showed change of some degree.

X-irradiation; lung pathology

Submitted on October 2, 1964
Left ventricle myocardial temperatures in the intact dog
Authors: Afonso Skoda , O'Brien George S. , McKenna David H. , Jaramillo Cesar V. , Rowe George G.
Published: December 2017

Gradients between left ventricle myocardial temperatures and that of the left ventricle blood were measured by transthoracic route in the intact dog. Results revealed that myocardial temperature is not uniform. Higher gradients were found in the basal portion of the interventricular septum and the papillary muscles and lower ones in the apical region. These differences are thought to be related to the thickness of myocardium as well as the relation between metabolic activity and vascularity of the sites where the temperatures were measured.

temperature gradients, left ventricle; myocardium, temperature gradients; heart-blood/myocardium temperature gradients; papillary muscle temperature

Submitted on July 17, 1964
Instantaneous blood flow in the human aorta
Authors: Snell Robert E. , Clements James M. , Patel Dali J. , Fry Donald L. , Luchsinger Peter C.
Published: December 2017

The computed pressure-gradient technique has been applied to the measurement of instantaneous aortic blood flow in 15 male subjects. The mean values of those curves obtained in the ascending aorta were compared with simultaneous measurements made by the dye-dilution technique. The correlation coefficient between the two methods was 0.85 and the slope of the regression line 0.80. The ability to measure flow by the pressure-gradient technique depends mainly on the accuracy of the catheter-manometer system, radius measurement, and the estimation of “zero flow.”

pressure-gradient technique; methods of blood flow measurement

Submitted on June 22, 1964
Responses of oxygen electrodes to variables in construction, assembly, and use
Authors: Carey Francis G. , Teal John M.
Published: December 2017

Oxygen electrodes were tested for response to variables in construction, assembly, and use. The half-wave potential was found to be inversely proportional to the KOH concentration used in assembling the electrode. The half-wave potential was moved to higher voltages by the use of thin membranes and by the use of Teflon rather than polyethylene membranes. This potential was not affected by cathode size, aging of the electrode, temperature, or replacement by carbonate of the hydroxide behind the membrane. Stirring effects can be reduced by low temperature, thick membranes, and small cathodes. Response time is the same for polyethylene and Teflon membranes and is proportional to the square of membrane thickness. Electrode blank, stability, and zero oxygen error are all discussed. The use of Teflon membranes, 1 n KOH as electrolyte, and 1.1-v polarization voltage is recommended.

voltage plateau; Teflon membrane; respirometry; polarographic oxygen eletrode

Submitted on September 14, 1964
Respiration and cerebrospinal fluid pH in metabolic acidosis and alkalosis
Authors: Mitchell R. A. , Singer M. M.
Published: December 2017

An acute base deficit of 5 mm/liter (metabolic acidosis) was induced in one normal man by an initial oral dose of 20 g NH4Cl and sustained for 5 days by administering 3 g every 6 hr. pHa (arterial) decreased from 7.42 to 7.34 in 4 hr. Ve (minute ventilation) increased from 6.2 to 8.4 liters/min, PaCOCO2 decreased from 40 to 37 mm Hg, CSF pH increased from 7.32 to 7.34, and the CO2 response curve shifted –2.8 mm Hg Pco2 without slope change. At 24 hr, CSF pH was 7.32, with CSF Pco2 and HCO3 – reduced to 42 mm Hg and 21.0 mEq/liter, respectively (control 49 mm Hg, 24 mEq/liter). Ve increased to 9.8 liters/min, arterial pH increased to 7.37, PaCOCO2 fell to 36 mm Hg, and the CO2 response curve was –5.0 mm Hg from control. After 6 days of acidosis, acute increase in pHa to 7.45 in 2 hr by NaHCO3 ingestion decreased Ve to 6.8 liters/min, increased PaCOCO2 to 39 mm Hg, decreased CSF pH to 7.30, and shifted the CO2 response curve back to control. Results of this study are consistent with the hypothesis that the peripheral chemoreceptors initiate and sustain alterations in Ve in metabolic abnormalities in the following manner: 1) acute acidosis increases Ve by stimulating the peripheral chemoreceptors; 2) the PaCOCO2 falls and CSF pH increases, decreasing medullary (H+) chemoreceptor activity; and 3) active transport across the blood-CSF barrier restores CSF pH and the medullary (H+) chemoreceptor activity to normal, causing a further increase in ventilation that partially compensates for the metabolic acidosis.

medullary respiratory chemoreceptors; peripheral chemoreceptors; blood-brain barrier; active transport

Submitted on July 27, 1964
Venous admixture in dogs with chronic pulmonary hypertension
Authors: Kentera Dusan , Wallace Charles R. , Hamilton William F. , Ellison Lois T.
Published: December 2017

In dogs with chronic pulmonary hypertension due to infestation with Dirofilaria immitis (heartworm disease) positive correlation was found between the rise in mean pulmonary arterial pressure and the increase in venous admixture. No abnormality was observed in pulmonary diffusing capacity or pulmonary capillary blood volume and results were essentially the same in the normotensive and hypertensive animals. Increased venous admixture in dogs with high pulmonary artery pressure was explained by increased flow through arteriovenous shunts in the lungs. Hypoventilation, atelectasis with perfusion of unventilated alveoli, and anatomical shunting through patent ductus arteriosus or foramen ovale were eliminated as causes. The possible importance of this phenomenon from the standpoint of survival is mentioned.

pulmonary capillary blood volume; variation in pulmonary; arteriovenous shunts; pulmonary diffusing capacity; dirofilariasis and pulmonary circulation; heartworm disease and pulmonary circulation; pulmonary diffusion and chronic pulmonary hypertension; surface tension

Submitted on February 26, 1965
Variation in cardiac output with acid-base changes in the anesthetized dog
Authors: Carson S. A. Allan , Chorley Gordon E. , Hamilton F. Norman , Lee Do Chil , Morris Lucien E.
Published: December 2017

Studies were performed in dogs anesthetized with pentobarbital, 30 mg/kg, and ventilated mechanically during succinylcholine apnea in order to ascertain the variation in cardiac output under various acid-base conditions. The findings were: 1) metabolic acidosis decreases cardiac output; 2) increasing respiratory acidosis in the absence of severe metabolic acidosis causes increase in cardiac output; 3) increasing respiratory acidosis in the presence of severe metabolic acidosis causes depression of cardiac output. The effect on cardiac output of changing arterial pH at steady PaCOCO2 is shown quantitatively. The relationship of PaCOCO2 to “pH adjusted” cardiac output is determined. From these data a nomogram is presented from which the combined effects of arterial pH and PaCOCO2 on cardiac output can be estimated.

cardiac output and anesthesia; acid-base status and cardiac output; pH and cardiac output; PaCOCO2 and cardiac output

Submitted on June 29, 1964
Human eccrine sweat gland activity and palmar electrical skin resistance
Authors: Adams Thomas , Vaughan John A.
Published: December 2017

Sweat gland activity, monitored as a function of the rate at which water vapor was removed from the skin surface (EWL), was measured simultaneously with electrical skin resistance (ESR) from adjacent 1-cm2 areas on the human palm. Both ESR and EWL, and Delta ESR and Delta EWL, were correlated throughout 20–30 min of testing during which the subject rested or participated in conversation. The ratio Delta ESR/Delta EWL was greater the lower the EWL level. As EWL approached diffusion levels (0.06 mg/min.cm2), ESR assumed the highest and most stable value (ca. 170 kilohms). Subject differences in ESR at high EWL rates and the pattern of ESR-EWL relationships through the range of sudomotor activity (0.06–0.18 mg/min.cm2) are attributed to individual variation in the density and activity of sweat glands on the palmar surface. The character of ESR-EWL correspondence was also seen to vary with the phase of sweating activity for any one subject.

evaporative water loss; physiological testing; galvanic skin reflex; psychological testing; psychogalvanic reflex; sweat measurement

Submitted on October 22, 1964
A critique: relationship of the time derivative of pressure to blood flow
Authors: Greenfield Joseph C. , Fry Donald L.
Published: December 2017

The relationship of the time derivative of pressure to instantaneous aortic blood flow was studied in six dogs. Pressure was measured with calibrated high-fidelity manometry and flow with an electromagnetic flowmeter. The true time constants of the equation of fluid motion (relating blood flow to the pressure gradient) were calculated and compared to the magnitude of time constants necessary to produce flow contours computed from the pressure time derivative that empirically “matched” flows measured by the electromagnetic flowmeter. It was found that time constants which produced acceptable “matching” were approximately 20 times too large. This observation demonstrated that 1) the time derivative of pressure is not proportional to the pressure gradient and 2) the similarity of measured and computed flows, using the pressure derivative, depends not on the laws of fluid motion but rather on the accidental similarity of the final form of the equation of fluid motion (with pressure derivative substituted for pressure gradient) to an empirical equation describing the hydraulic input impedance to the aorta.

pressure gradient technique; blood velocity; analog computer

Submitted on September 30, 1964
Cortical CO2 and O2 at high pressures of argon, nitrogen, helium, and oxygen
Authors: Bennett Peter B.
Published: December 2017

In 37 chloralosed cats (45–50 mg/kg) exposed to increased pressures of argon, nitrogen, or helium between 8.67 and 10.8 atm abs in the presence of either 0.2 or 2.34 atm abs oxygen or oxygen alone, the cortical carbon dioxide was measured with a modified Severinghaus electrode and the cortical oxygen polarographically. In mixtures with an oxygen partial pressure of 2.34 atm abs, the cortical oxygen increased above controls. The greater the density of the mixture then, the less was the increase. The cortical carbon dioxide also increased, but conversely, the greater the density of the mixture the greater the increase in carbon dioxide. In mixtures of low oxygen partial pressures, the cortical oxygen was below control values whereas the carbon dioxide showed little change except for a slight increase with the heavier argon mixture. Inert gas narcosis, as indicated by depression of auditory induced cortical spikes, did not correlate with the changes in cortical carbon dioxide but with the inert gas itself. Increasing the oxygen partial pressure and the density of the mixture respired caused retention of brain carbon dioxide, which synergistically potentiated the narcosis.

nitrogen narcosis; inert gases; depth intoxication; tissue carbon dioxide; tissue oxygen; brain

Submitted on August 10, 1964
Temperature regulation in young women
Authors: Haslag Sister Wilma Marie , Hertzman Alrick B.
Published: December 2017

Possible sexual differences in the regulation against acceptable heat loads were studied by exposing female and male subjects to rising ambient temperature, TA (1 hr at 25 C, then 6.6 C/hr to 45 C) or to steady TA (43.3 C for 3 hr). Women were studied during the menstrual, preovulatory, and postovulatory periods. Oral (TO) and skin (TS) temperatures, cutaneous opacity pulses, regional sweating rates, and weight losses were measured. During the menstrual and preovulatory periods, the thermoregulatory responses of women were similar to those of men except for slightly larger cutaneous opacity pulses and greater rates of weight loss in several of the male subjects. The TO, but not TS, was consistently higher in women during heat exposures in the postovulatory period. Of several possible explanations, a higher setting of the hypothalamic thermostat seems the more probable reason for the elevation of TO without a corresponding increase in weight loss, regional sweating, and cutaneous opacity pulses. In other respects there were no essential differences in temperature regulation attributable to sex.

regional sweating; body temperatures; regional cutaneous vasodilatation; moderate heat loads; temperature regulation during the menstrual cycle

Submitted on September 14, 1964
NaCl and CaCl2 activity coefficients in mixed aqueous solutions
Authors: Moore Edward W. , Ross James W.
Published: December 2017

In the investigation of numerous physiological phenomena it is the activity of an ion species which is desired, rather than stoichiometric concentration. The calculation of mean ionic activity from known concentration data requires accurate activity coefficients (ggr). This report concerns the determination of ggrNaCl and ggrCaCl2 in mixed NaCl-CaCl2 solutions by potentiometric measurement with a sodium-selective glass electrode-Ag/AgCl electrode system over the ionic strength range 0.05–0.5 m. Log ggrNaCl varied linearly, at constant total ionic strength, with the ionic strength of CaCl2 in the mixture, in accordance with Harned's rule. From data thus obtained, ggrCaCl2 coefficients in such mixed solutions have been calculated and compared with values calculated from published osmotic data. Resulting activity coefficient curves for ggrCaCl2 are presented over the concentration range encountered in serum and other extracellular fluids.

Note:

(With the Technical Assistance of Leonard Kaye and Leonard L. Anderson)

glass electrodes; ion interaction; electrolyte metabolism; Harned's rule; membrane transport; osmotic coefficients

Submitted on March 11, 1965
Reflex increase in ventilation by muscle receptors with nonmedullated fibers (C fibers)
Authors: Kalia Madhu , Senapati J. M. , Parida B. , Panda A.
Published: December 2017

The reflex increase in ventilation (Ve) produced by natural stimulation of certain sensory receptors in gastrocnemius muscle was studied in dogs anesthetized with Na pentobarbital. Reflex increase in Ve occurred when the endings of group III fibers and nonmedullated fibers were stimulated (by stretching, pressing, or squeezing the muscle locally), whereas the endings of group I and group II fibers were blocked by repetitive antidromic stimulation. Stimulation of endings of nonmedullated fibers alone also increased Ve after all the medullated fibers were blocked either by cooling the medial gastrocnemius nerve to 5 C or by stimulating lateral gastrocnemius nerve repetitively. It was concluded that there were sensory endings of nonmedullated fibers in muscles which are stimulated by stretching, pressing, or squeezing the muscle locally; these endings produce reflex hyperventilation.

antidromic stimulation; gastrocnemius muscle
Splanchnic hemodynamic response to passive hyperventilation
Authors: Johnson E. E.
Published: December 2017

Two groups of anesthetized, splenectomized, and paralyzed dogs were hyperventilated (Vt 40 ml/kg). Normocapnia was maintained in one group (mean Paco2 37.6 mm”h′g, mean p”h ′7.41) and respiratory alkalosis (mean Paco2 8 mmHg, mean pH 7.75) in the other. Splanchnic hemodynamic responses were similar in both groups. Average hepatic venous pressure increased from 3.2 to 6.4 mmHg in the normocapnic group and from 3.8 to 7.7 mmHg in the hypocapnic group. Average portal venous pressure increased from 10.7 to 12.0 mmHg and 10.8 to 12.7 mmHg in the normocapnic and hypocapnic groups, respectively. Mesenteric vascular resistance increased in 93 per cent of dogs. A decrease in functional intestinal capillary surface area during hyperventilation was indicated by a significant reduction in mesenteric Vo2 (from 15 to 11 ml/min, average 30 per cent), and a concomitant reduction in mesenteric O2 extraction ratio. Changes in mesenteric Vo2 were reflected in calculated splanchinic Vo2. Hepatic O2 uptake was essentially unchanged by tidal hyperventilation with or without hypocapnia.
Influence of perfusion rate and compliance on esophageal manometry
Authors: Zabinski M. P. , Spiro H. M. , Biancani P.
Published: December 2017

The accuracy of esophageal manometry using the conventional perfused three-lumen catheter depends on the proper choice of the perfusion rate. Previous investigators have used a wide range of perfusion rates without considering the compliance of the transducer-catheter assembly as a variable in the selection of the perfusion rate for the hydraulic systems. We present a relationship relating the perfusion rate and the compliance which specifies the minimum adequate perfusion rate for a given transducer-catheter assembly. This approach explains apparent discrepancies in the literature regarding the proper rate of perfusion for accurate measurement of esophageal contractions. Esophageal motility tests with 10 subjects confirmed the accuracy of manometric tests at the prescribed perfusion rate (1.25 ml/min) since they compared well with intraluminal pressures measured directly with a Honeywell intraesophageal transducer. The effect of perfusion rate on the apmlitude of esophageal contraction was also investigated and it is shown that high perfusion rates result in increased amplitudes of contraction. Furthermore, at large perfusion rates a large volume of liquid builds up in the esophagus. This fluid accumulation could possibly be responsible for the increased amplitudes of contraction.
Oxygen delivery and utilization in dogs with a sublethal dose of cobalt chloride
Authors: Cain S. M.
Published: December 2017

Four groups of eight dogs each were anesthetized with pentobarbital, paralyzed with succinylcholine, and ventilated at constant rate. Control measurements were made for 30 min, then 15 mg/kg of cobaltous chloride was given slowly intravenously to one group. A second group was also given 1 mg/kg per h propranolol (beta-block); a third group was given NaHCO3 to correct pH changes after CoCl2; and a fourth group had both beta-block and NaHCO3. Vo2 was measured every 10 min for 4 h and blood was taken frequently for lactate, pyruvate, and blood gas measurements. Cobalt transiently decreased Vo2 in all groups but significantly more in those with beta-block (groups 2 and 4). Cardiac output and mean arterial pressure were also decreased in all groups but to similar extent. Recovery of Vo2 was complete, usually within 60 min with little evidence of deficit repayment. Total O2 transport (Q X Cao2) appeared to limit Vo2 below 12 ml/kg times min. Above that value, histotoxic effects of CoCl2 reduced Vo2 approximately 20%. Excess lactate (XL) in arterial blood was linearly correlated with measured O2 deficit during the acute reaction of CoCl2, in all but group 3, similar to results previously obtained in hypoxic hypoxia.
Measurement of percent oxyhemoglobin in the microvasculature
Authors: Pittman R. N. , Duling B. R.
Published: December 2017

A new method is applied to the determination of percent oxyhemoglobin (percent saturation) in whole blood. The method is based on a theoretical treatment of light absorption and scattering by particulate suspensions and requires the measurement of optical densities (D) of blood at three closely spaced wavelengths. The optical density of red blood cell (RBC) suspensions was measured with a video microdensitometer and a linear relationship was found between percent saturation and the corrected optical density ratio, (D555 B)/(D546 B). For a given saturation, this ratio was independent of optical path length (12 mum-2 mm), hematocrit (3–50%), and RBC velocity (1.5–17 mm/s). The applicability to microvascular measurements has been assessed through the use of TV microdensitometry on micropipettes with flowing RBCs and on microvessels in the hamster cheek pouch.
Ventilatory response to drug-induced hypermetabolism
Authors: Levine S. , Huckabee W. E.
Published: December 2017

Previous workers have demonstrated that an increase in minute ventilation accompanies tissue hypermetabolism induced by uncouplers of oxidative phosphorylation. The mechanism of this increase in minute ventilation has not been established. Accordingly, 2.5 mg/kg of 2,4-dinitrophenol (DNP) or 8–15 mg/kg of ethyl methylene blue (EMB) were infused into chloralose-anesthetized mongrel dogs; Vo2 increased 105 plus or minus 3% and VE INCREASED 107 PLUS OR MINUS 14%. Heads of vagotomized dogs were then perfused entirely with normal unchanging blood. Spinal cord remained intact. (The carotid bodies lay within the region of the perfused head.) Ventilatory responses of these head-perfused animals to breathing low oxygen and to breathing high CO2 gas mixtures were greatly attenuated. However, when DNP or EMB was infused into the body, VO2 increased 114 plus or minus 23% and VE increased 123 plus or minus 22%. When similar doses of DNP or emb were selectively administered to the head, increases in VE were limited to 21 plus or minus 6%. It is concluded that a major portion of the stimulus to ventilation, which accompanies infusion of DNP or of EMB, arises in tissues other than arterial chemoreceptors and brain. Presumably, this ventilatory stimulus is transmitted to the respiratory center via afferent pathways of the cervical spinal cord.
Effects of epinephrine on resisitive and compliant properties of the canine vasculature
Authors: Mitzner W. , Goldberg H.
Published: December 2017

The peripheral circulation of 22 anesthetized dogs was separated into three parallel regions, where the outflow from each region could be measured and both outflow and inflow pressures could be controlled. We were thus able to estimate arterial and venous resistance and venous compliance for each region. The pressure dependency of these parameters was determined before and during continuous infusion of epinephrine (3 mug-kg-1 min-1). Epinephrine increased the arterial resistance in all regions but did so in such manner as to increase the fraction of cardiac output perfusing the splanchnic region. The venous resistances were all elevated by epinephrine and showed a greater pressure dependency than during control. Systemic venous complicance was found to be pressure dependent during both control and epinephrine administration, decreasing by nearly 50% from the lowest to the highest venous pressures (4–12 mmHg) investigated. Splanchnic compliance was found to comprise nearly half the total systemic compliance. Results were interpreted using an extension of the parallel compartment model of the peripheral circulation described by Caldini, Permutt, Waddell, and Riley (2).
A new gas lesion syndrome in man, induced by "isobaric gas counterdiffusion"
Authors: Lambertsen C. J. , Idicula J.
Published: December 2017

Normal men have been found to develop pruritis and gas bubble lesions in the skin, and disruption of vestibular function, when breathing nitrogen or neon with oxygen while surrounded by helium at increased ambient pressure. This phenomenon, which occurs at stable ambient pressures, at 1 or many ATA, has been designated the “isobaric gas counterdiffusion syndrome.” In a series of analyses and experiments in vivo and in vitro the cause of the syndrome has been established as due to gas accumulation and development of gas bubbles in tissues as a result of differences in selective diffusivities, for various respired and ambient gases, in the tissue substances between capillary blood and the surrounding atmosphere. The phenomenon here described in man is an initial stage of a process shown later in animals to progress to continuous, massive, lethal, intravascular gas embolization.
Distribution volumes of [131I]albumin, [14C]sucrose, and 36Cl in sheep lung
Authors: Selinger S. L. , Bland R. D. , Demling R. H. , Staub N. C.
Published: December 2017

We measured the steady-state volumes of distribution for radioactive chloride, sucrose, and albumin in the lung of six anesthetized, spen-thorax sheep. We allowed 2 days for [131I]albumin to equilibrate throughout the body, 2 h for the 36Cl, and a 40-min constant infusion for [14C]sucrose before killing the animal. Five minutes before death, we gave [125I]albumin to tag lung plasma volume. We killed the animals by clamping both lung hila; we then removed the lungs and homogenized them. We measured residual red cell and plasma volume, total extravascular lung water, and the extravascular content of the three tracers. The distribution volumes expressed as fractions of blood-free lung weight were: 36Cl equals 0.44, sucrose equals 0.28, and albumin equals 0.07. If the sucrose distribution volume is taken as the best estimate of the lung's extravascular extracellular space, then chloride clearly overestimates the interstitial fluid volume, being either bound or partially intracellular. On the other hand, albumin clearly underestimates the interstitial fluid volume.
A technique for measurement of retrograde coronary blood flow in intact anesthetized dogs
Authors: Afonso K. , Friede G. L. , Blau F. M. , Bandow G. T. , Rowe G. G.
Published: December 2017

A technique for measurement of retrograde coronary blood flow in intact anesthetized dogs is described. Occlusion of the coronary artery is produced by the inflation of a small rubber balloon at the tip of a no. 9 cardiac catheter placed under fluorescopy in a branch of the left coronary artery. Blood which bleeds back from the occluded coronary artery through the no. 9 catheter is diverted into a small reservoir of 1-ml capacity. The time to fill this reservoir is recorded electrically. Retrograde coronary blood flow is calculated from the time required to fill this reservoir. Results indicate good repeatability of meadurements. The technique seems to be a simple, adequate, and convenient means for assessing agents for possible vasodilator action on the collateral circulation in intact animals.
Carbon monoxide-induced localized toxic anoxia in the rat brain cortex
Authors: Dora E. , Chance B. , Kovach A. G. , Silver I. A.
Published: December 2017

A new method has been developed for the determination of maximal reduction of NAD in the rat cerebral cortex. NADH fluorescence (450 nm) induced by 366-nm light and UV reflectance were measured by a time-sharing light pipe fluorometer. The redox state of the cortical surface was altered by perfusion of oxygen or carbon monoxide through a Teflon chamber adjacent to the dura. This study examines changes caused by local perfusion with the two gases in normoxia, hypoxia, and anoxia. Alternation of topical carbon monoxide and oxygen becomes effective in altering the intracellular redox state at 15% inspired oxygen and caused 20% changes at zero inspired oxygen. Conversely, topical application of oxygen to the systemically anoxic tissue causes oxidation of reduced NAPH in the cells within the field of fluorometric observation equivalent to that caused by breathing approximately 8% oxygen systemically.