bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Oxygen-Transporting System in Relation to Age
Authors: Davies C. T. M. 
Published: August 2015

1. An extensive study of the functional and dimensional components of the oxygen-transporting system in relation to age and the indirect estimation of maximum aerobic power (V̇o2max.) has been conducted on eighty healthy male subjects aged 20–50 years. Measurements were made of ventilation, cardiac frequency and blood lactic acid expressed in terms of oxygen intake of 1·51/min (V̇e, 1·5; fh, 1·5 and LA, 1·5 respectively) maximum blood lactic acid, ventilation and oxygen intake, thigh (TM) and calf (CM) and total body muscle estimated from soft tissue radiographs, whole body potassium (40K), blood volume (BV), heart volume (HV), and tests of lung function.
2. In the younger subjects it was shown that the functional and dimensional capacities of the O2-transporting system were closely integrated and the performance of organs in relation to size was essentially similar. In older subjects there was a gradual decline in the overall capacity to transport oxygen which was closely associated with a decrease in the functional rather than the dimensional aspects of the cardiovascular system. In terms of a given body weight the dimensional capacities of the older subjects, BV, THb (total body haemoglobin), 40K, TM CM, were shown to be independent of age.
3. The best single guide to V̇o2max. was given by BV in subjects under 35 years of age and by HV in older subjects. By using a multiple regression on either V̇e, 1·5, fh, 1·5 and leg muscle or FVC, HV, TM and age, V̇o2max. could be estimated with coefficient of variation of ∼9%. This is ∼2% improvement on conventional methods of determining V̇o2max. from measurements of fh and V̇o2 taken at four levels of work and in addition when using the latter equation there is no need for the subject to exercise. The use of these equations and their clinical application to the testing of V̇o2max. in large community studies of physical working capacity are discussed.
The Effects of Sodium Loading and Deprivation on Plasma Renin and Plasma and Urinary Aldosterone in Hypertension
Authors: Coghlan J. P. , Doyle A. E. , Jerums G. , Scoggins B. A. 
Published: August 2015

1. Measurements of urinary aldosterone excretion and of peripheral venous plasma concentrations of aldosterone, Cortisol and corticosterone have been made in hypertensive and normotensive patients after a sodium load and after dietary sodium restriction and ambulation.
2. Plasma concentrations of aldosterone, Cortisol and corticosterone did not differ significantly between the two groups of patients, but the rise in urinary aldosterone excretion was significantly greater in normotensive than in hypertensive patients after sodium restriction.
3. Division of the hypertensive patients into two groups according to the response in plasma renin on sodium restriction did not disclose any significant differences between responders and non-responders in respect of aldosterone or Cortisol, but the plasma corticosterone rose more in normotensive patients after sodium depletion than in the unresponsive hypertensive patients.
4. It is concluded that both the rise in plasma renin and in aldosterone excretion rate are blunted in hypertensive patients after sodium restriction. It is suggested that this may be due to a rise in total body sodium in hypertensive patients.
5. Differences in aldosterone excretion rate are not reflected in the values of peripheral venous concentrations, presumably because of the short-term rise in plasma aldosterone which results from ambulation.
Role of the Kidney in ‘Salt and Water Dependent Hypertension’ of End-Stage Renal Disease
Authors: Bianchi G. , Ponticelli C. , Bardi U. , Redaelli B. , Campolo L. , De Ponti C. , Graziani G. 
Published: August 2015

1. Blood pressure, plasma renin concentration, exchangeable body sodium, plasma volume and extracellular fluid volume were measured in five patients on maintenance haemodialysis for end-stage renal disease in whom hypertension was relatively easy to control by the combination of dialysis and restriction of salt intake. Measurements were made on three occasions: on a free salt intake the day before dialysis; on a low salt intake the day after dialysis; on a free salt intake the day before dialysis after nephrectomy.
2. The fall of blood pressure after haemodialysis and salt intake restriction was accompanied by a decrease of exchangeable body sodium and body fluids while plasma renin concentration increased. The fall of blood pressure after bilateral nephrectomy was accompanied by a fourfold decrease of plasma renin without any change of the other variables.
3. The hypertension of these patients might thus be considered ‘salt and water dependent’ or ‘renin dependent’ according to the means used to decrease blood pressure.
The Effects of Synthetic Human and Salmon Calcitonins on Electrolyte Excretion in the Rat
Authors: Williams C. C. , Matthews E. W. , Moseley Jane M. , MacIntyre I. 
Published: August 2015

1. The effects on renal electrolyte excretion of human and salmon synthetic calcitonins were studied in the rat.
2. As little as 50 ng of salmon calcitonin produced an increase in sodium excretion, but human calcitonin in doses up to 15 μg had only a slight effect.
3. Small doses of both hormones decreased urinary calcium and magnesium. Larger doses of salmon calcitonin produced less depression of calcium and magnesium excretion even in the presence of a greater fall in plasma calcium.
4. The mechanisms responsible for these effects and the possible therapeutic implications are discussed.
Role of Pulmonary Vagal Afferent Nerve Fibres in the Development of Rapid Shallow Breathing in Lung Inflammation
Authors: Trenchard Diana , Gardner D. , Guz A. 
Published: August 2015

1. The administration of the polysaccharide carageenin through a catheter into the lungs of cats and rabbits has produced an inflammatory lesion confined to one lobe of a lung. The lesion consisted of an alveolar and interstitial infiltration with polymorphonuclear leucocytes and, subsequently, macrophages. There was no apparent damage to alveolar walls and no pleurisy. The rest of the lung remained normal.
2. In both conscious cats and anaesthetized rabbits there was an increased frequency of breathing dependent on an intact vagus nerve on the same side as the lesion. It was independent of changes in body temperature and was not due to hypoxaemia.
3. By using a direct current to the right cervical vagus nerve in the rabbits (with the left vagus nerve sectioned), it has been possible to block conduction in myelinated fibres; the non-myelinated fibres conduct normally. Studies with this differentially blocked nerve have shown that the increased frequency of breathing is dependent on activity in the non-myelinated vagal afferent fibres.
Oral Contraceptives and Folate Metabolism
Authors: Stephens M. E. M. , Craft I. , Peters T. J. , Hoffbrand A. V. 
Published: August 2015

1. There are conflicting reports regarding the effect of oral contraceptives on serum and erythrocyte folate concentrations and on folate absorption. A detailed study of this problem was therefore undertaken.
2. It was first ascertained that there was no significant variation in serum folate concentrations at different stages in the normal menstrual cycle.
3. No significant difference was found in fasting serum folate concentrations between control subjects and those taking oral contraceptives.
4. Synthetic sex hormones did not inhibit jejunal pteroylpolyglutamate hydrolase in vitro.
5. Tests of absorption of pteroylglutamic acid (folic acid) and pteroylpolyglutamates in controls and women taking oral contraceptives showed no difference between the two groups, provided the subjects were presaturated with pteroylglutamic acid. Without presaturation, the rise in serum folate after oral pteroylpolyglutamates was significantly decreased in the women taking oral contraceptives, suggesting that the latter may alter folate clearance from the blood.
Experimental Vitamin B6 Deficiency and the Effect of Oestrogen-Containing Oral Contraceptives on Tryptophan Metabolism and Vitamin B6 Requirements
Authors: Rose D. P. , Strong R. , Adams P. W. , Harding P. E. 
Published: August 2015

1. A vitamin B6-deficient diet was fed to an adult male subject to confirm previously described changes in tryptophan metabolism and urinary 4-pyridoxic acid excretion, and erythrocyte alanine and aspartate aminotransferase activities.
2. The results were compared with those obtained in women taking oestrogen-containing oral contraceptives.
3. The development of dietary vitamin B6 deficiency was indicated by decreased 4-pyridoxic acid excretion, increased urinary concentrations of xanthurenic acid, kynurenine and 3-hydroxykynurenine, an elevated 3-hydroxykynurenine/3-hydroxyanthranilic acid ratio and impaired erythrocyte aminotransferase activities.
4. Tryptophan metabolites and 4-pyridoxic acid excretion were determined in thirty-one women when they had been taking an oral contraceptive for 6–36 months. Of these, twenty-six had abnormal tryptophan metabolism, but the 4-pyridoxic acid was decreased in only seven. In six of these seven a raised 3-hydroxykynurenine/3-hydroxyanthranilic acid ratio supported a diagnosis of subclinical vitamin B6 deficiency; erythrocyte alanine aminotransferase activity was determined in five of the six, and was decreased in three.
5. Erythrocyte aminotransferases were determined in sixteen women when they had been taking an oral contraceptive for 3–6 months, and in thirty-four women after 6–36 months treatment. Neither group showed any change in alanine aminotransferase activity, but the aspartate aminotransferase was elevated in the group treated for 6 months or longer.
Peripheral Airways Resistance, Static Recoil and the Forced Expiratory Volume
Authors: Cayton Ruth M. , Howard P. 
Published: August 2015

1. The forced expiratory volume (FEV0·75) was measured at increasing mouth pressures in twenty-seven patients with obstructive airways disease. Attempts were made to divide the patients on clinical grounds into emphysematous, bronchitic or asthmatic categories; there was no evidence from the (FEV/mouth pressure) plots that their airways functioned differently during forced expiration.
2. Static elastic recoil was measured in twelve patients. There was no evidence that this factor alone caused the loss of FEV in any patient.
3. It is suggested that the use of the FEV as a test of respiratory function during the natural history of obstructive airways disease should be considered in three stages. There is an initial phase when peripheral airways disease develops with little or no alteration of the FEV. In the second phase the FEV decreases from normal values to below 1·0 litre, and at this stage is considered a sensitive indicator of peripheral airways resistance. In stage 3 the FEV is low and further changes can only be small. But airways resistance continues to increase and could be a more sensitive measurement of further airways disease.
Renal Calculi and Self-Medication with Multivitamin Preparations Containing Vitamin D
Authors: Taylor W. H. 
Published: August 2015

1. Of 104 patients with renal calculi, 42% gave a history of previous self-medication with multivitamin preparations containing vitamin D, compared with 37% of a control group of fifty-one patients without renal calculi. This difference is not significant.
2. The mean supplemental daily intake of vitamin D and the annual intake were significantly higher in the patients with renal calculi than in the control group.
3. The highest mean supplemental intake of vitamin D occurred among those patients in whom no metabolic or other cause for renal stone formation could be found.
4. The first calculi presented within 2 years of the period of self-medication in twenty-four of thirty patients who had not previously suffered from renal stones.
5. The results suggest that self-administration of vitamin D should be included among the aetiological factors promoting the formation of renal calculi.
Effect of Intraluminal Concentrations on the Impairment of Glycine Absorption by Glucose in the Human Jejunum
Authors: Cook G. C. 
Published: August 2015

1. To investigate the effect of different intraluminal concentrations on the mutual inhibitive effect of glycine and glucose on their jejunal absorption rates, eighteen convalescent Zambian African patients who had no clinical evidence of intestinal disease or of malnutrition were given constant intrajejunal infusions with those solutes either together or alone. A double-lumen tube perfusion system was used, and three solutions containing (A) glycine, (B) glycine and glucose, and (C) glucose, all of which were rendered iso-osmotic with sodium chloride, were perfused in random order at 12·0 ml/min. The concentration of glycine in the perfusing fluid was either 10 or 20 mm, and that of glucose either 100, 200 or 280 mm. By reference to polyethylene glycol 4000, the absorption rates of the solutes and water were calculated for a 30 cm jejunal segment.
2. At a glucose concentration of 200 or 280 mm, but not 100 mm, the mean rate of glycine absorption was decreased by approx. 30%. Glucose absorption rates were not significantly altered by glycine.
3. These observations, taken in conjunction with those from a previous investigation, are consistent with the view that there are two mechanisms for the jejunal absorption of glycine in man, one of which is inhibited by glucose at high intraluminal concentration.
Inhibition of Sodium and Potassium Transport in Separated Renal Tubule Fragments Incubated in Extracts of Urine Obtained from Salt-Loaded Individuals
Authors: Clarkson E. M. , De Wardener H. E. 
Published: August 2015

1. Extracts of urine were prepared from salt-depleted and salt-loaded subjects by gel filtration of freeze-dried urine on Sephadex G-50. The extracts were dissolved and adjusted to physiological pH and electrolyte concentration.
2. Separated renal tubule fragments were prepared from rabbit kidney cortex and their intracellular sodium and potassium measured after incubation in the dissolved adjusted extracts. Those concerned with the measurement of intracellular sodium and potassium did not know the identity of the samples.
3. Extracts of urine from salt-loaded subjects inhibited the sodium and potassium transport of the tubules whereas extracts of urine from salt-depleted subjects had no effect.
4. Of ten known hormones that were tested, none had any inhibitory effect on the sodium transport of the tubule fragments.
5. It is concluded that the oral intake of large amounts of salt in normal subjects causes the appearance of an unknown substance in the urine which inhibits sodium transport in separated renal tubule fragments.
Mechanisms of Excretion of Some Low-Molecular-Weight Bases in the Rat
Authors: Bourke E. , Asatoor A. M. , Milne M. D. 
Published: August 2015

1. The excretion of structural analogues of ammonia in acidic and alkaline urine was investigated. The lipid-soluble compounds n-propylamine, n-butylamine and n-amylamine and the water-soluble compounds hydrazine and methylhydrazine resemble ammonia in being more rapidly excreted in acidic urine. By contrast, the excretion of the water-soluble amines methylamine and ethylamine is unaffected by changes in urinary pH.
2. Arguments are advanced, based on the results, that pH-dependent excretion of ammonia is due to diffusion of the water-soluble un-ionized fraction through the aqueous phase of the cell membrane, and the same applies to the hydrazines. However that of n-propylamine and the higher-molecular-weight alkylamines is due to diffusion through the lipid phase of the cell membrane. The data suggest that this latter form of diffusion is the more rapid one.
3. After injection of glutamyl-γ-methylamide and the corresponding ethylamide, both methylamine and ethylamine excretions are significantly higher in acidosis, rising further in chronic acidosis. This indicates that the glutaminase II pathway of ammonia genesis increases in activity in the acidotic rat in vivo.
Excretion of Propionylglycine in Propionic Acidaemia
Authors: Rasmussen K. , Ando T. , Nyhan W. L. , Hull D. , Cottom D. , Donnell G. , Wadlington W. , Kilroy A. W. 
Published: August 2015

1. The urinary excretion of acylglycines has been studied in four patients with propionic acidaemia.
2. Propionylglycine was found in each of the patients.
3. This compound has not previously been detected in human body fluids. Propionylglycine was not present in the urine of control subjects or patients with non-ketotic hyperglycinaemia.
4. The excretion of propionylglycine was greatest in patients receiving the least dietary control.
Renin and Control of Arterial Blood Pressure during Terminal Renal Failure Treated by Haemodialysis and by Transplantation
Authors: Verniory A. , Potvliege P. , Van Geertruyden J. J. , Vereerstraeten P. , Kinnaert P. , Staroukine M. , Toussaint C. 
Published: August 2015

1. Plasma renin concentrations were determined in 1068 samples obtained in 113 patients in the end stage of chronic renal failure treated by repeated haemodialyses or by renal transplantation.
2. Patients with malignant nephroangiosclerosis have a very high concentration of plasma renin; this differentiates them from other disease groups, where renin concentration is sometimes normal and sometimes elevated; there is no significant difference between the glomerulonephritis and pyelonephritis groups.
3. There is a weak but significant correlation between plasma renin concentration and arterial blood pressure. In the terminal stage of chronic renal insufficiency, blood pressure appears to be controlled by other quantitatively more important factors. However, the hypertension of some cases, characterized by high concentrations of plasma renin, can be controlled only by bilateral nephrectomy.
4. There is an inverse and highly significant correlation between plasma renin and sodium concentrations. This is also the case in transplanted patients where an inverse correlation also exists between plasma renin concentration and daily urinary output of sodium.
5. The juxtaglomerular granulation index correlates positively with the plasma renin concentration.
6. In terminal renal failure the kidney retains its capacity to secrete renin as a response to acute haemorrhage or other stimuli.
7. Renin is present in the blood of anephric patients and its concentration is not correlated either with the patient's sex or with the time elapsed after binephrectomy.
8. During rejection episodes in transplanted patients a rise of plasma renin concentration is frequently but not invariably observed. Elevation of plasma renin concentration is evident in very acute rejection crises.
Water and Sodium Excretion after Blood Volume Expansion under Conditions of Constant Arterial, Venous and Plasma Oncotic Pressures and Constant Haematocrit
Authors: Lichardus B. , Nizet A. 
Published: August 2015

1. The diuretic and natriuretic responses occurring during expansion of blood volume by homologous blood transfusion were studied in homologous kidneys transplanted to the neck of hydropenic dogs that had previously been given deoxycorticosterone acetate and antidiuretic hormone. The experimental conditions ensured constant arterial perfusion pressure, venous pressure, osmotic pressure, haematocrit and plasma oncotic pressure.
2. Moderate but significant increases in urine output, renal sodium excretion, osmotic clearance and tubular sodium rejection fraction were observed; there were no significant changes in glomerular filtration rate, renal blood flow, postglomerular haematocrit and postglomerular plasma protein concentration 20 and 40 min after the end of blood infusion.
3. As the non-hormonal factors known to modulate sodium excretion underwent no significant change, the results are compatible with the proposition that a specific factor (‘natriuretic hormone’) plays a role in the mechanism of natriuresis after blood volume expansion.
Reversibility of Airways Obstruction in Chronic Bronchitis
Authors: Astin T. W. 
Published: August 2015

1. Airways resistance and lung volume were measured in twenty-five patients with chronic bronchitis and fifteen patients without chest disease before and after the inhalation of isoprenaline. Similar measurements were made on fourteen of these patients with chronic bronchitis and twelve other patients without chest disease before and after the intravenous injection of atropine sulphate.
2. There were significant decreases in airways resistance after isoprenaline inhalation and intravenous atropine both in patients with bronchitis and normal subjects but the decreases were greater in the patients with chronic bronchitis.
3. The decrease in resistance was proportional to the degree of initial airways resistance.
4. The results are considered to indicate that bronchial muscle contraction increases the airways resistance of patients with chronic bronchitis and contributes to the airways obstruction; its contribution increases with increasing severity of the condition. A significant part of the increased airways resistance in these patients is potentially reversible and nervously mediated.
The Effect of Experimental Immune Complex Nephritis on Rat Serum Proteins
Authors: Horne C. H. W. , Toner P. G. 
Published: August 2015

1. A radial immunodiffusion technique was used to determine the concentrations of five rat serum proteins, slow α1- and α2-globulin, transferrin, albumin and γ2-globulin before and after the induction of immune complex nephritis.
2. Four weeks after immunization with renal tubular antigen significant increases in transferrin, slow α2-globulin and γ2-globulin concentrations were observed but albumin showed a significant fall and slow α1-globulin did not change.
3. After the development of proteinuria 7 weeks after immunization significant falls in the concentrations of albumin transferrin and γ2-globulin were noted along with significant increases in the macroglobulins, slow α1- and α2-globulin, the changes being similar to those seen in the nephrotic syndrome in man.
4. At the end of the experiment the typical ultrastructural features of immune complex nephritis were observed.
Serum Bactericidal Activity in Patients with Upper and Lower Urinary Tract Infections
Authors: Gower P. E. , Taylor P. W. , Koutsaimanis K. G. , Roberts A. P. 
Published: August 2015

1. Serum bactericidal activity against the homologous organism was determined in patients with urinary tract infections and has been related to the site of infection and to serum antibody titres.
2. A significantly higher number of patients with upper compared to lower urinary infections were found to have either a specific defect in bactericidal activity against the homologous organism or to be infected with organisms inherently resistant to normal serum bactericidal activity.
3. It is suggested that these factors may be important in determining the site of urinary tract infections.