bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Brief Hypercalcaemia on Free Water Reabsorption during Solute Diuresis: Evidence for Impairment of Sodium Transport in Henle's Loop
Authors: Guignard J-P. , Jones N. F. , Barraclough M. A. 
Published: August 2015

1. The relationship between osmolal clearance (Cosm) and the reabsorption of solute free water (Tch2o) was examined during mannitol and hypertonic saline diureses in both normocalcaemic and hypercalcaemic rabbits.
2. At high values for Cosm (2–4 ml/min) in normocalcaemic rabbits Tch2o during saline diuresis exceeded that during mannitol diuresis as previously shown.
3. Prolonged hypercalcaemia (72–96 h) reduced Tch2o in both mannitol and saline diureses.
4. Brief hypercalcaemia (18–24 h) abolished the increment in Tch2o normally seen during saline, as compared with mannitol diuresis. This impairment of Tch2o during saline diuresis occurred at a time after the start of hypercalcaemia when Tch2o during mannitol diuresis was still unaffected.
5. The results cannot be attributed to an effect of hypercalcaemia on membrane permeability to water, and are best explained by a reversible limitation of sodium transport in Henle's loop. This interpretation is supported by the fact that the hypercalcaemic rabbits excreted a greater percentage of the filtered sodium load than did the controls.
Albumin Metabolism in Chronic Renal Failure
Authors: Coles G. A. , Peters D. K. , Jones J. Henry 
Published: August 2015

1. Plasma albumin concentration was measured in fifty-eight patients with chronic renal failure. The mean value was 3·27 g/100 ml (SD 0·44 g/100 ml; range 2·4–4·3 g/100 ml) which is significantly lower (P &lt; 0·001) than normal (mean 3·94 g/100 ml; SD 0·23 g/100 ml; range 3·5–4·4 g/100 ml). In thirty-eight of the fifty-eight patients (65%), plasma albumin concentration was below the normal range. Treatment by maintenance haemodialysis or renal transplantation usually corrected the hypoalbuminaemia.
2. Radioactive iodine-labelled albumin turnover was investigated in twelve patients. Although plasma albumin concentration was reduced in eight of the twelve patients, the plasma half-life (T½) of the labelled albumin was normal or increased in all but one of these patients. Fractional and absolute albumin degradation rates (which include urinary albumin loss) were reduced in six of the twelve patients. In two of the four patients with normal plasma albumin concentrations the fractional albumin degradation rate was reduced.
3. Albumin synthesis was estimated by measuring the rate of incorporation into plasma proteins of 14C in two patients on a 20 g protein diet. The values were low in both.
4. Albumin catabolism and albumin synthesis were normal in two patients who had been on regular haemodialysis for 5 and 8 weeks respectively.
5. We conclude that these abnormalities in albumin metabolism were probably due to severe protein depletion, induced either by prolonged anorexia and vomiting or by deliberate restriction of protein in the diet in the course of treatment.
The Natriuresis of Fasting: Relationship to Changes in Plasma Renin and Plasma Aldosterone Concentrations
Authors: Chinn R. H. , Brown J. J. , Fraser R. , Heron Sheila M. , Lever A. F. , Murchison Lilian , Robertson J. I. S. 
Published: August 2015

1. The relationship of changes in plasma renin and plasma aldosterone concentration to electrolyte balance was studied during total fasting and during sodium deprivation followed by total fasting.
2. During simple sodium deprivation obese subjects lost significantly more sodium than lean subjects, but the rise in plasma renin concentration (PRC) was similar in the two groups.
3. During total fasting there was a failure of PRC to increase in the expected manner despite a marked negative sodium balance. In the early stages of the fast, PRC decreased in nine of eleven subjects while subsequently it increased in all subjects.
4. During sodium deprivation PRC and plasma aldosterone concentration (PAC) rose in all subjects studied, but in the first few days of a period of total fasting immediately following, there was a fall in PRC in eight of ten subjects studied, while PAC continued to rise in five of six subjects in whom it was measured.
5. These results are discussed in relation to the concept of the renin-angiotensin system as a regulator of aldosterone secretion.
Lysozyme Excretion as a Measure of Renal Tubular Dysfunction in Children
Authors: Barratt T. M. , Crawford Rita 
Published: August 2015

1. Activity of the low molecular weight enzyme lysozyme was measured in the plasma and urine of healthy adults and children and of children with renal disease.
2. No difference was detected between lysozyme excretion (expressed as the lysozyme/creatinine clearance ratio) of healthy adults and neonates, implying that the proximal tubular function of protein reabsorption is mature in the neonate.
3. The lysozyme/creatinine clearance ratio was not elevated in the nephrotic syndrome: thus a heavy load of filtered albumin does not interfere with low molecular weight protein reabsorption.
4. Very high values of lysozyme/creatinine clearance were observed in children with the Fanconi syndrome; there was no overlap with any other group studied.
5. Children with pyuria had a very slight increase in urine lysozyme/creatinine concentration ratio.
The Effect of Vasopressin on the Reabsorption of Sodium, Potassium and Urea by the Renal Tubules in Man
Authors: Barraclough M. A. , Jones N. F. 
Published: August 2015

1. Changes in the urinary concentrations or urine/plasma (U/P) ratios of creatinine, urea, sodium and potassium were determined during the transition from water diuresis to antidiuresis when normal subjects and patients with diabetes insipidus were given injections of vasopressin.
2. In confirmation of previous work, it was found that after vasopressin administration the urinary concentration or U/P ratio of urea rose to a lesser degree than that of creatinine, indicating an increase in the tubular reabsorption of urea.
3. The urinary concentration, or U/P ratio, of sodium also rose to a lesser degree than that of creatinine. Thus vasopressin also increases the tubular reabsorption of sodium.
4. In contrast, the urinary concentration or U/P ratio of potassium tended to rise more than that of creatinine, indicating a decrease in the net tubular reabsorption of potassium.
5. Quantitative changes in the tubular handling of these urinary solutes were assessed by calculating the ratio—solute concentration during antidiuresis/solute concentration during diuresis—and then expressing this as a percentage of the corresponding ratio for creatinine. In subjects on a normal or high sodium intake the values thus obtained were: urea 72% (99% confidence limits 65–81%); sodium 79% (99% confidence limits 68–92%) and potassium 119% (99% confidence limits 102–139%).
6. In salt depleted subjects the values for these ratios were: urea 63% (99% confidence limits 60–65%) and sodium 36% (99% confidence limits 33–40%). Vasopressin had no consistent effect on potassium reabsorption in salt depleted subjects.
7. The effects of vasopressin on normal subjects and on patients with diabetes insipidus were similar.
8. It is suggested that these effects of vasopressin on sodium and potassium handling by the kidney occur in the collecting duct.
Estimates of Arterial Pco2 and Their Effect on the Calculated Values of Cardiac Output and Dead Space on Exercise
Authors: Godfrey S. , Davies C. T. M. 
Published: August 2015

1. A study of exercise physiology in 117 children aged 6–16 is described including the measurement of cardiac output by the Indirect (CO2) Fick Principle.
2. Computer produced graphs enabled various alternative values for arterial Pco2 (Pa,co2) to be inserted simultaneously into the Fick equation for cardiac output and the Bohr equation for dead space.
3. Dead space could be estimated with reasonable accuracy using end-tidal Pco2.
4. Cardiac output determination was unreliable at rest due to the small venoarterial Pco2 difference but it was very good on exercise when this difference is much larger.
5. The Pa,co2 used for the calculation of cardiac output could be derived either from ear lobe Pco2 or end-tidal Pco2. However, the best estimate of cardiac output was that using the Pa,co2 implied by assuming a normal dead space.
Interrelation between Restitution Time-Constant and Alternating Myocardial Contractility in Dogs
Authors: Mahler Y. , Rogel S. 
Published: August 2015

1. In open chest dogs with complete heart block the ventricles were stimulated electrically at various steady rates, and a single premature or delayed beat was interposed to alter myocardial tension. This was followed by transient mechanical alternans. Steady alternans was induced by high stimulation frequencies.
2. It appeared that the recovery of the force of contraction of a beat could be approximated by an exponential function of the preceding time interval. We observed a correlation between the time-constant of this exponential curve and the force of contraction of the previous beat.
3. The results demonstrate that a general rule of mechanical alternans can be expressed by a single equation. This equation describes adequately (1) the duration of transient mechanical alternation produced by a delayed beat, (2) the production of steady alternation at rapid ventricular rates, and (3) the manifestations of post-extrasystolic potentiation during mechanical alternans.
4. Curves relating amplitude of one beat to the successive beat, based on experiments performed in in vivo dog hearts, corresponded to the results predicted by the equation.
The Influence of Adrenergic Receptor Blocking Agents on the Mouse Thyroid
Authors: Kendall-Taylor Pat , Munro D. S. 
Published: August 2015

1. The influence of adrenergic receptor blocking drugs on the mouse thyroid gland maintained in vitro has been investigated.
2. Phentolamine, an α adrenergic blocking drug, and propranolol, a β blocking drug, inhibited the release of [131I]iodothyronines from pre-labelled mouse thyroids, which otherwise occurred when the glands were incubated in the presence of thyroid stimulating hormone, long acting thyroid stimulator, or cyclic 3′5′-adenosine monophosphate.
3. Evidence is presented to show that (a) the inhibition is not due to adrenergic blockade, (b) the effect cannot wholly be attributed to the prevention of adenyl cyclase activation, (c) the mechanism of action of the two drugs is dissimilar.
4. The observed clinical response in the treatment of thyrotoxicosis does not appear to be related to this antithyroid effect of propranolol.
Chromatographic and Bioautographic Estimation of Plasma Cobalamins in Various Disturbances of Vitamin B12 Metabolism
Authors: Linnell J. C. , Hoffbrand A. V. , Peters T. J. , Matthews D. M. 
Published: August 2015

1. This paper reports a survey of values for individual plasma cobalamins in normal subjects, hospital controls, and patients with vitamin B12 deficiency and diseases in which there are disturbances of B12 metabolism. The values were obtained by thin-layer chromatography and bioautography followed by photometric scanning or visual assessment.
2. Normal plasma contains methylcobalamin (the predominant component), deoxyadenosylcobalamin and hydroxocobalamin. The latter two compounds are not separable in the solvent system routinely used. In some samples there were traces of cyanocobalamin. The ratio of methylcobalamin to deoxyadenosylcobalamin plus hydroxocobalamin, normally greater than 1·0, was reduced in B12 deficiency. Many cases of untreated pernicious anaemia showed a high proportion (up to 40%) of cyanocobalamin. In folate deficiency there was no consistent change in individual cobalamins. Patients with leukaemias and liver disease showed a variety of changes, some attributable to alterations in plasma binding capacity and loss of deoxyadenosylcobalamin from the liver.
3. After oral or parenteral administration of cyanocobalamin, plasma cyanocobalamin increased and there was evidence of conversion to methylcobalamin. After parenteral administration of methylcobalamin, this compound increased in the plasma, but deoxyadenosylcobalamin plus hydroxocobalamin did not change.
4. Possible reasons for pathological changes in individual plasma cobalamins are discussed.
Depression of δ-Aminolaevulic Acid Dehydrase Activity by Ethanol in Man and Rat
Authors: Moore M. R. , Beattie A. D. , Thompson G. G. , Goldberg A. 
Published: August 2015

1.β-Aminolaevulic acid (ALA) dehydrase activity has been measured in the blood of man and rats and in the tissues of rats intoxicated with ethanol.
2. ALA dehydrase activity was significantly depressed in the blood of man. This depression follows closely on the elevation of blood ethanol and returns to normal pari passu with the ethanol level.
3. In rats intoxicated with ethanol there is a significant depression of ALA dehydrase activity in blood, liver and kidney but not in heart or spleen.
4. A scheme is proposed whereby an increase in the intracellular redox potential by ethanol increases sulphydryl cofactor concentrations leading to an inhibition of enzyme activity.
Gas-Induced Osmosis as a Factor Influencing the Distribution of Body Water
Authors: Hills B. A. 
Published: August 2015

1. Two methods have been used to determine whether differences in gas concentrations between adjacent regions of tissue can induce osmosis.
2. In a steady-state experiment water has been shown to move in the direction of increasing gas concentration across gross sections of excised tissues such as bladder and peritoneum.
3. In a second experiment it was found that more water was retained in subcutaneous pockets of saline saturated with a soluble gas (nitrous oxide or ethylene) than was retained in a control pocket saturated with nitrogen and simultaneously monitored in the same rabbit.
4. A value of the reflexion coefficient for nitrous oxide has been estimated from the results of the experiments with the gross tissue sections and shown to be compatible with those known for non-gaseous solutes by extrapolation with respect to molecular size.
5. The significance of possible osmotic effects due to transient gas concentration gradients are discussed in connection with dry joints, aseptic bone necrosis in caisson workers and inert gas narcosis, the approach offering a quantitative correlation of narcotic potency by a simple physical mechanism.
6. The steady-state gas concentration gradients which arise in tissue as a result of metabolism are suggested as a third driving force in homeostasis but, unless larger reflexion coefficients can be demonstrated, this effect would only appear to be significant for inspired oxygen partial pressures appreciably greater than normal.
Respiratory Responses to Sustained Static Muscular Contractions in Humans
Authors: Wiley R. L. , Lind A. R. 
Published: August 2015

1. Respiratory responses to sustained static forearm and leg contractions performed separately and simultaneously were investigated in human volunteers.
2. Oesophageal pressure measurements indicated no tendency to breath hold or fix the thorax during fatiguing static contractions.
3. Marked hyperventilation occurred invariably with the static efforts, resulting in striking increases in ventilatory equivalent and reduction of end-tidal CO2. Simultaneous contraction of arm and leg muscle groups did not result in additive respiratory responses.
4. Contractions performed during circulatory occlusion or cool water immersion of the involved limb produced results which led to the conclusion that the hyperventilation is not due to stimulation of pain fibres, nor to stimulation of chemoreceptors locally or centrally by metabolites released from the active muscle. Some additional possible mechanisms responsible for the hyperventilation are discussed.
Pulmonary Function in Chronic Severe Anaemia
Authors: Guleria J. S. , Pande J. N. , Markose M. M. , Gupta R. G. , Jain B. P. 
Published: August 2015

1. The process of pulmonary ventilation and gas exchange was investigated in twenty-three young patients with chronic severe anaemia, before and after its correction.
2. Various lung volumes, pulmonary mechanics, minute ventilation, oxygen consumption and carbon dioxide production were found to be normal in anaemic patients.
3. There was a mild respiratory alkalosis in anaemia. The arterial oxygen tension was lowered because of a marked widening of the alveolar-arterial oxygen tension gradient. This was mainly because of an increase in the anatomical shunt as well as ventilation/perfusion inequalities.
4. The transfer factor (pulmonary diffusing capacity) in anaemia was very much reduced. The diffusing capacity of the alveolar capillary membrane was usually decreased and volume of blood in the alveolar capillaries usually increased but these changes were not statistically significant.
Genetic Influences in Drug Responses of the Eye and the Heart
Authors: Bertler Å. , Smith S. E. 
Published: August 2015

1. Pupillary responses to locally applied phenylephrine and cardiac responses to intravenous hyoscine N-butylbromide have been studied in ten pairs each of healthy monovular and binovular twins aged between 24 and 60 years.
2. Under identical lighting conditions resting pupil diameters differed widely among individuals, being greater in female subjects and in those with larger irides and smaller with increasing age.
3. Monovular twins, but not binovular twins, showed significant concordance in iris diameter, initial pupil diameter, initial heart rate and responses to both drugs. The results suggest that these responses were dependent on the concordance of peripheral sympathetic and parasympathetic tone within each twin pair.
4. It is concluded that much of the variability in response to drugs acting on the autonomic nervous system is determined by physiological factors and that these are genetically influenced.
Ketone-Body Concentrations in Liver and Blood after Limb Ischaemia in the Rat
Authors: Barton R. N. 
Published: August 2015

1. The effect of a 4 h period of bilateral hind limb ischaemia on the concentrations of ketone bodies in blood and liver of post-absorptive and starved rats has been investigated.
2. The concentration of total ketone bodies in the blood did not change after injury in post-absorptive rats, but fell after injury in starved rats; the blood β-hydroxybutyrate/acetoacetate ratio fell after injury in both post-absorptive and starved rats.
3. Apart from a transient increase in fed rats, the hepatic β-hydroxybutyrate/acetoacetate ratio did not change after injury in post-absorptive or starved rats until the terminal stages, indicating adequate hepatic oxygenation during the early response to injury.
4. In control post-absorptive and starved rats the concentration of liver total ketone bodies was correlated with that of plasma non-esterified fatty acids; in post-absorptive rats the liver ketone body concentration rose after injury and was higher than would be predicted from the regression line for these controls, suggesting increased ketogenesis compatible with inhibition of complete oxidation of non-esterified fatty acids after injury. In contrast, in starved rats the liver total ketone-body concentration did not change after injury.
Patterns of Ventilatory Response to Carbon Dioxide during Recovery from Severe Asthma
Authors: Rebuck A. S. , Read John 
Published: August 2015

1. Ventilatory response to CO2 was measured regularly by a rebreathing technique in nineteen patients with severe asthma from the day of presentation to the time of clinical recovery.
2. Ventilatory response to CO2 increased during recovery in sixteen patients and the increased ventilatory response correlated well with increase of FEV1. Among these sixteen patients only one showed elevation of arterial CO2 tension at the time of presentation.
3. Ventilatory response to CO2 failed to increase during recovery in three patients despite increases in FEV1. All three patients showed elevation of arterial CO2 tension at the time of presentation.
4. In five patients (including three of the four with initial hypercapnia) ventilatory response to CO2 after recovery remained below the previously reported lower limit for normal subjects. The limits of normality were explored by examining ventilatory response to CO2 in seventeen outstanding athletic performers. Values for ventilatory response to CO2 both above and below the previously defined ‘normal range’ were found. The normal ventilatory response to CO2 covers a 14-fold range from 0.57 to 8.17 1 min−1 mmHg−1Pco2.
Renal Vasodilatation: Effect on Renal Handling of Phosphate
Authors: Ahumada J. J. , Massry S. G. 
Published: August 2015

1. The combined effects of unilateral renal vasodilatation produced by acetylcholine or bradykinin and intravenous infusion of angiotensin on phosphate excretion and reabsorption were investigated in fourteen anaesthetized dogs. The influence of these manoeuvres on the excretion of sodium, calcium and magnesium was also evaluated.
2. Unilateral renal vasodilatation alone produced an increase in the excretion of phosphate, calcium, magnesium and sodium; and the infusion of angiotensin caused further augmentation of the excretory rates of these ions from the vasodilated kidney in most experiments.
3. The maximal tubular reabsorptive capacity (Tm) for phosphate was decreased by renal vasodilatation.
4. There was a close and significant correlation between the fraction of the filtered load of phosphate, calcium, and magnesium which was excreted and that of sodium.
5. The results indicate that renal vasodilatation with or without the infusion of angiotensin causes a decrease in the renal tubular reabsorption of phosphate, calcium, magnesium and sodium.
Studies with Radioactive Copper (64Cu and 67Cu); The Incorporation of Radioactive Copper into Caeruloplasmin in Wilson's Disease and in Primary Biliary Cirrhosis
Authors: Gibbs Kathleen , Walshe J. M. 
Published: August 2015

1. A comparison has been made of the handling of radioactive copper by patients with Wilson's disease, patients with primary biliary cirrhosis and a small control group. The object of this study has been to assess the influence of an expanded hepatic pool of copper on the incorporation of radioactive copper into caeruloplasmin.
2. Studies with 67Cu have shown that radioactivity disappears steadily from the plasma of patients with Wilson's disease for periods up to 296 h. Both in patients with primary biliary cirrhosis and in controls, a well-marked secondary rise occurs as radioactive copper is incorporated into caeruloplasmin.
3. Caeruloplasmin has been isolated from the serum of one control subject, one patient with primary biliary cirrhosis and one with Wilson's disease. Of the plasma radioactivity 90% was present in the caeruloplasmin of the control subject and the patient with primary biliary cirrhosis; only 27% was found in the caeruloplasmin of the patient with Wilson's disease.
4. Turnover time for liver copper has been determined; in the control subjects it was of the order of 20–30 days, in the patients with primary biliary cirrhosis it was between 600 and 700 days, in Wilson's disease the time exceeded 1800 days. In all cases the turnover time for radioactive copper was significantly less.
5. We conclude (a) that newly arrived radioactive copper is preferentially handled in the presence of copper overload and (b) dilution of radioactive copper in an expanded hepatic pool of the metal cannot alone account for the delayed incorporation found in patients with Wilson's disease.