bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leg Blood Flow during Exercise in Man
Authors: Jorfeldt L. , Wahren J. 
Published: August 2015

1. An indicator-dilution technique was used to determine human leg blood flow at rest and during exercise. The method is based on the infusion of Indocyanine Green into the femoral artery with blood sampling from the femoral vein at the level of the inguinal ligament. Evidence for mixing of dye and blood is presented, based on the finding of equal dye concentrations at two different sampling levels in the femoral vein. The minimum time of infusion required for equilibration at rest is 3 min and during exercise 1 min 20 s.
2. Leg blood flow was measured in eight healthy athletic subjects at rest and during upright exercise on a bicycle ergometer at 400, 800 and 1200 kpm/min. Linear relationships were found between blood flow on the one hand and work intensity and pulmonary oxygen uptake on the other.
3. Leg oxygen uptake was measured as the product of blood flow and femoral arterio-venous oxygen difference. Linear regressions were found for leg oxygen uptake in relation to both work intensity and pulmonary oxygen uptake. Leg mechanical efficiency during exercise averaged 34%.
4. A formula for the approximate calculation of leg blood flow is suggested, based on the pulmonary oxygen uptake and the femoral arterio-venous oxygen difference.
The Excretion of Salicylate in Salicylate Poisoning
Authors: Morgan A. G. , Polak A. 
Published: August 2015

1. The renal clearance of salicylate has been measured in two groups of patients undergoing treatment by alkaline diuresis for salicylate poisoning. One group received mannitol and sodium lactate, the other acetazolamide and sodium bicarbonate.
2. The relationship between urine pH and salicylate clearance was found to be the same in both groups and similar to that shown at non-toxic concentrations in the blood by previous workers.
3. The influence of the rate of urine flow on the relationship between salicylate clearance and urine pH was also shown to be similar to that found at non-toxic concentrations in the blood.
Studies on Acid Excretion in Adults with Sickle-Cell Anaemia
Authors: Kong H. HO Ping , Alleyne G. A. O. 
Published: August 2015

1. The acid excretion of patients with sickle-cell anaemia has been studied.
2. There is a mild defect in urinary acidification and a decreased H+ excretion in response to ammonium chloride loading.
3. The acidification defect was not corrected by oral administration of a phosphate solution.
4. Infusion of a sodium sulphate solution in subjects who were avidly reabsorbing sodium produced equal degrees of urine acidification in patients and controls.
5. Studies on bicarbonate reabsorption were inconclusive.
6. We conclude that patients with sickle-cell anaemia have a mild form of incomplete distal renal tubular acidosis.
Studies in Man with 18F
Authors: Hosking D. J. , Chamberlain M. J. 
Published: August 2015

1. The distribution of intravenously administered 18F was investigated in thirty-one normal human volunteers, seven patients with acute or chronic renal failure and two patients with malignant disease. The object was to define some features of the bodily distribution and handling of 18F in the hope that this will shed some light on fluoride physiology in health and disease.
2. Plasma radioactivity at any given time depends on the degree of diffusion of 18F through the extracellular fluid as well as on the competing effects of renal excretion and tissue uptake. The factors governing these last two functions are discussed.
3. At 1 h after injection 40% of the administered dose of 18F is contained in the extracellular fluid, 20% has been excreted and 40% taken up by the tissues, including 2·5% into erythrocytes.
Total and Nutritional Blood Flow in the Finger
Authors: Coffman J. D. 
Published: August 2015

1. Total and nutritional flow in the fingertip were investigated during reflex sympathetic nerve stimulation (total body cooling) or adrenergic nerve transmitter administration. Nutritional flow was measured by the disappearance rate of a local depot of Na131 I, and total fingertip flow by venous occlusion plethysmography.
2. With body cooling the decrease in nutritional flow was not significant, but total and therefore arteriovenous shunt flow decreased significantly.
3. Norepinephrine infused into the brachial artery decreased total and nutritional flow significantly although total flow decreased more than nutritional.
4. It is concluded that sympathetic nervous system activity exerts a greater effect on finger arteriovenous shunt flow than on nutritional flow. Therefore nutritional flow is not adversely affected.
Distribution and Properties of Na+, K+-ATPase in Human Post-Mortem Kidney and the Effects of Diuretics
Authors: Tulloch B. R. , Gibson K. , Harris P. 
Published: August 2015

1. Adenosine triphosphatase activity dependent on Mg2+ and activated by Na+ and K+ has been found in a microsomal fraction of homogenates of human postmortem kidneys.
2. Various characteristics of the enzyme system are described.
3. Activity is greater in the medulla than in the cortex.
4. Diuretic drugs inhibit activity in vitro only at high concentrations.
Observations on the Measurement and Regulation of the Sodium Content of Human Erythrocytes
Authors: Smith E. K. M. 
Published: August 2015

1. The sodium concentration within the erythrocytes of 159 subjects was found to be 7·35 ± 1·25 (SD) mmol/litre of cells.
2. In 157 normal subjects, the erythrocyte potassium concentration was 99·08 ± 5·3 (SD) mmol/litre of cells.
3. In the erythrocytes from twenty-seven normal subjects there was a striking linear correlation between the rate constant for active sodium efflux and resting sodium concentration.
4. It is concluded that these studies confirm the assumption that the resting concentration of sodium within a cell is determined by the activity of the sodium pump. What is not known is the mechanism by which this precise control is maintained.
Analysis of Changes in the Renin-Angiotensin System during Pregnancy
Authors: Skinner S. L. , Lumbers Eugenie R. , Symonds E. M. 
Published: August 2015

1. Determinations of plasma renin activity (PRA), plasma renin concentration (PRC) and renin substrate (RS) were made on single plasma samples from thirty-four women at various stages of pregnancy. Comparisons were made with non-pregnant control subjects.
2. All three variables were elevated above controls throughout pregnancy, but whereas the mean value of PRA was equally high between the first and the second halves of pregnancy, PRC was higher in the first and RS higher in the second half of pregnancy.
3. Kinetic studies indicated that, in spite of high concentrations of RS in late pregnancy, the renin-renin substrate reaction remains substrate dependent when proceeding at physiological pH values.
4. No differences in enzyme-substrate affinity were detected between the plasmas of pregnant and non-pregnant women.
5. In each of three deliveries RS was lower in the foetus than in the mother but PRA and PRC did not display consistent gradients.
6. PRC in uterine venous blood was slightly lower (P = 0·05) than in peripheral blood during caesarian section at term.
7. On deriving PRC from PRA by using the Michaelis-Menten equation, a physiologically inactive component in maternal PRC became apparent. It is suggested that this component is activated by the acid treatment used in the direct PRC methodology. Its concentration is highest in early pregnancy and circumstantial evidence suggests that it originates from foetal chorion.
The Response of Blood Pressure to Infusion of Angiotensin II: Relation to Plasma Concentrations of Renin and Angiotensin II
Authors: Chinn R. H. , Düsterdieck Gisela 
Published: August 2015

1. In thirty-nine normotensive and hypertensive human subjects plasma concentrations of angiotensin II during pressor infusions of the peptide were significantly related to the concentrations found before infusion began.
2. When mean diastolic pressure before and during lower rates of angiotensin infusion were plotted against concurrent plasma angiotensin II concentrations, a straight-line relationship was observed. This relationship also held for the higher rates of infusion in some subjects.
3. During infusion at a standard rate of 4 ng min−1 kg−1 the rise in plasma angiotensin II concentration varied widely from subject to subject.
4. There was a significant negative relationship between this increase and the threshold of the pressor response to angiotensin.
5. There was a significant positive relationship between the threshold of the pressor response and the basal concentrations of renin and angiotensin II.
6. These results suggest that angiotensin normally present in blood lies within or close to a range capable of affecting blood pressure.
Carbon Monoxide, Tissue Hypoxia, and Sensory Psychomotor Response in Hypoxaemic Subjects
Authors: Ramsey J. M. 
Published: August 2015

1. Twenty normal subjects, twenty patients with emphysema and twenty with anaemia breathed 0·03% carbon monoxide for 45 min. For all sixty the mean increase in carboxyhaemoglobin (COHb) was 4·5%. Patients with emphysema showed a significantly smaller increase than did the other two groups.
2. The mean decrease in oxygen content was 209 vol./100 ml and was significantly less in patients with emphysema than in the other two groups.
3. All sixty subjects showed a significant diminution in reaction speed to a visual stimulus, but no significant change in tests for depth perception and visual discrimination for brightness.
4. No differences among the three groups were observed in respect to these psychological tests.
5. It is concluded that COHb concentrations of 5% may adversely affect reaction time to visual stimuli and that patients with emphysema are less susceptible to accumulation of COHb and decrease in venous oxygen content than normal subjects or patients with anaemia.
Pathogenesis of Arterial Hypertension after the Constriction of the Renal Artery Leaving the opposite Kidney Intact Both in the Anaesthetized and in the Conscious Dog
Authors: Bianchi G. , Baldoli E. , Lucca R. , Barbin P. 
Published: August 2015

1. The renal artery was constricted leaving the opposite kidney intact in ten conscious and seven anaesthetized dogs. Intravenous infusion of exogenous renin was done in seven conscious dogs; in four of these the renal artery was constricted 15–17 days later. The following variables were measured in all animals before and after renal artery constriction: plasma renin concentration, blood pressure, cumulative sodium balance, plasma volume, extracellular fluid volume and plasma non-protein nitrogen. Before and after renal artery constriction in the conscious dogs cardiac output, stroke volume, total peripheral resistance and cardiac rate were also measured. In a few dogs angiotensin responsiveness and plasma concentration of renin substrate were also measured.
2. There was no significant difference between the regression of change in blood pressure on change in plasma renin concentration within 2 h from renal artery constriction in the conscious dogs and that observed during intravenous infusion of renin. Comparing the changes of these variables with the ones previously obtained with renal artery constriction to the lone remaining kidney, for a given increase of plasma renin concentration the rise of blood pressure was lower when the contralateral kidney was untouched. The changes of the other variables in the conscious dogs may be divided into three phases: a first phase lasting hours, in which, besides the changes described above, there was an increase of total peripheral resistance while the other variables remain unchanged: a second phase, 24 h after constriction, in which blood pressure, total peripheral resistance and plasma renin clearance decreased while plasma volume, cardiac output and extracellular fluid volume slightly increased; however, only the plasma volume change was statistically significant: and a third phase 6–7 days after constriction, when all the variables returned towards normal values, except that the blood pressure and total peripheral resistance remained significantly higher. Sodium balance remained at equilibrium throughout the study period. It is suggested that these results are compatible with the ‘autoregulation theory’ of renal hypertension.
3. Renal artery constriction in the anaesthetized animals caused a slight but significant sodium retention that very likely influenced the sequence of the events. On the second day after constriction, the plasma renin concentration was significantly increased, whereas the highest values of blood pressure, plasma volume and extracellular fluid volume occurred on the seventh day after constriction.
Exchangeable Potassium Content and Distribution in Normal Subjects and Uraemic Patients on Chronic Haemodialysis
Authors: Rettori V. , Gral T. , Massry S. G. , Villamil M. F. 
Published: August 2015

1. Exchangeable potassium, sulphate space and intracellular fluid have been determined in eight normal males and in seven uraemic male patients on a regime of twice weekly 8 h dialysis.
2. Intracellular water was more closely correlated with exchangeable potassium than were body weight or lean body mass.
3. There was no correlation between exchangeable potassium and plasma or erythrocyte potassium.
4. Uraemic patients had a 20% potassium depletion that may have been due to a restricted oral intake (40 mmol/day) and too little potassium (0–1 mmol/l) in the dialysis fluid.
The Effect of Acute Portacaval Shunting in Dogs on Cerebral and Peripheral Blood Flow and Metabolism
Authors: James I. M. , MacDonell Lindsay , Xanalatos C. 
Published: August 2015

1. Changes in brain and hind-limb blood flow and metabolism have been studied in six dogs before and after the acute shunting of portal vein blood into the systemic circulation.
2. An initial increase in brain blood flow, oxygen and glucose consumption was found.
3. More prolonged shunting caused a fall in flow and in oxygen and glucose utilization by the brain.
4. Although peripheral blood flow and oxygen consumption were reduced by shunting glucose consumption was increased throughout the period of shunting.
5. The possible mechanisms of these changes is discussed, together with their relevance to the causation of encephalopathy in patients after portacaval shunts.
Elevation of Alcohol Dehydrogenase Activity in the Subclinically Scorbutic Guinea-Pig
Authors: O'keane Maureen , Moore M. R. , Goldberg A. 
Published: August 2015

1. Because it has been shown that a majority of alcoholics are subclinically scorbutic, the metabolism of ethanol was studied in subclinically-scorbutic guinea-pigs.
2. Hepatic alcohol dehydrogenase activity was raised maximally by ethanol within 2 days.
3. In twenty-three subclinically-scorbutic guinea-pigs fed ethanol for 2 weeks, the alcohol dehydrogenase activity (±SD) was 11·5 ± 1·2 units/g of liver protein compared with 8·6 ± 0·6 units/g of liver protein in twenty-three healthy animals fed ethanol.
4. The NAD+/NADH ratio in subclinically-scorbutic guinea-pigs and healthy guinea-pigs fed ethanol, shows that there is more NAD+ available for oxidation of alcohol in subclinically-scorbutic guinea-pigs. These results may explain the increased tolerance of alcoholics to alcohol.
Effect of Exercise on the Renal Clearance of Amylase and Lysozyme in Humans
Authors: Poortmans J. R. 
Published: August 2015

1. Total protein amount and amylase and lysozyme activities were measured in the serum and urine of healthy women and men before and after strenuous exercise.
2. Exercise produced no major difference in the serum activities of amylase and lysozyme.
3. The renal clearance of amylase was unaffected by strenuous exercise, but total protein excretion was markedly increased.
4. Very high values of renal clearance of lysozyme were observed after exercise. This implies that the proximal tubular function of protein reabsorption was specifically affected.
The Effect of Sub-Threshold Doses of Pentagastrin on the Acid Response to Insulin in Duodenal Ulcer Subjects before and after Truncal Vagotomy
Authors: Elder J. B. , Gillespie G. , Gillespie I. E. , Crean G. P. , Kay A. W. , Campbell E. H. G. 
Published: August 2015

1. On the basis of previously described dose-response curves, small doses of pentagastrin were infused in duodenal ulcer patients before and after vagotomy. No increase or decrease in gastric acid output was noted, confirming that the doses of pentagastrin used were sub-threshold.
2. In twenty-six duodenal ulcer patients the effect of sub-threshold doses of pentagastrin on the insulin response resulted in three distinct patterns. (i) In subjects with clearly functioning vagal pathways, no increase in acid output occurred after insulin when a sub-threshold dose of pentagastrin was added; (ii) patients with equivocal acid responses to insulin alone showed augmentation of acid output when given insulin and a sub-threshold pentagastrin infusion; (iii) patients with no response to insulin after truncal vagotomy showed some increase in acid output to the combined agents, and in two patients, criteria for a clearly positive acid response were satisfied.
3. We conclude from these studies that potentiation exists between insulin-induced cholinergic stimulation and infusion of sub-threshold doses of pentagastrin in man.
Uric Acid in Advanced Renal Failure
Authors: Danovitch G. M. , Weinberger J. , Berlyne G. M. 
Published: August 2015

1. The results of studies of renal uric acid excretion in eleven patients with advanced chronic renal failure are presented.
2. The pyrazinamide suppression test was used to separate secretion from reabsorption of uric acid in the renal tubule.
3. There is a marked increase in the excretion and clearance of uric acid as renal function deteriorates. This was due to a striking increase in tubular secretion of urate and to incomplete reabsorption of filtered urate.
4. The remarkable functional capacity of the remaining nephrons of the chronically diseased kidney with respect to uric acid transport might be due to a uricosuric factor in uraemic serum.
The Effect of Caloric Intake on Nitrogen Balance in Chronic Renal Failure
Authors: Hyne B. E. B. , Fowell Edna , Lee H. A. 
Published: August 2015

1. Nitrogen balance in uraemic patients on similar nitrogen intakes improves with increasing caloric intake in the range of 36–55 cal/kg body weight.
2. The degree of improvement in nitrogen balance is compatible with increased utilization of endogenous nitrogen probably as a result of increased dietary calories.
Uptake of Dipeptides Containing Basic and Acidic Amino Acids by Rat Small Intestine in Vitro
Authors: Burston D. , Addison Jill M. , Matthews D. M. 
Published: August 2015

1. The characteristics of transport and hydrolysis of twenty-two dipeptides containing basic and acidic amino acids by rat ileal rings were investigated in vitro. The peptides included combinations of basic and neutral, basic and basic, basic and acidic, acidic and acidic, and acidic and neutral amino acids.
2. All peptides studied were removed intact from the bulk phase of the incubation medium, though, in general, only free amino acids appeared in the tissue. Uptake of one or both constituent amino acids was greater from the peptide than from the equivalent amino acid or amino acid mixture in the case of at least one peptide from each group and in eighteen of the twenty-two peptides studied. In general, there was no relationship between the extent of uptake of amino acids from peptides and the extent of their hydrolysis by the system. The results support the hypothesis that there is more than one mode of uptake of amino acids from peptides.
3. Hydrolysis of γ-glutamyl-l-glutamic acid by intact intestine or intestinal homogenate was slight, and intact peptide was taken up by the tissue. Uptake of free glutamic acid from this peptide was poor. Comparison of γ-glutamyl-l-glutamic acid with three other slowly hydrolysed dipeptides, glycyl-d-valine, sarcosylglycine and glycylsarcosine, suggested that all four were transported into the mucosal cells and hydrolysed intracellularly. The results indicate that the presence of a γ-linkage or a d-amino acid, or methylation of the free amino group as in sarcosylglycine, impair both transport and hydrolysis of peptide, but that attachment of a methyl group to the N of the peptide bond, as in glycylsarcosine, impairs hydrolysis but has no effect on peptide transport.
4. l-Aspartic acid and l-glutamic acid were extensively transaminated by the intestine, whether presented as free amino acids or in peptides. Evidence was obtained suggesting that production of alanine from aspartic acid resulted from direct transamination of aspartic acid with pyruvic acid, rather than from a sequence of two reactions involving aspartate and alanine aminotransferases.
5. The results show that more rapid uptake of amino acids from peptides than from free amino acids is not confined to peptides made up of neutral amino acids, and probably occurs with many small peptides. Uptake of lysine and the dicarboxylic amino acids, which are particularly slowly absorbed from free solution, was much greater from several dipeptides than from the free amino acids. The results suggest the importance of mucosal peptide uptake in protein absorption.
Humoral Immune Responses in the Tropical-Splenomegaly Syndrome in New Guinea
Authors: Crane G. G. , Rowley Merrill J. , Warburton M. F. , Mackay I. R. 
Published: August 2015

1. Humoral immune capacity was measured in New Guineans with tropical splenomegaly or who had been splenectomized for this disease, to assess relationships between tropical splenomegaly and immunological function; the test antigens were flagellin and monovalent influenza vaccine.
2. Controls included age- and sex-matched healthy and hospitalized Caucasians, and comparative data on responses to flagellin were available for New Guinean school children.
3. For flagellin, geometric mean titres in the primary immune response in New Guineans with tropical splenomegaly were significantly lower than those of other groups, whereas pre-immunization titres and those obtained during the secondary response were comparable.
4. For influenza vaccine, both pre-inoculation and peak mean post-inoculation titres of antibody were significantly lower in New Guineans, attributable possibly to lack of previous exposure to this antigen.
5. The low primary antibody responses in New Guineans with tropical splenomegaly could result from pre-emption of antibody-producing tissues arising from abnormal demands for antimalarial antibody; this may determine the increased susceptibility to, and high mortality from, bacterial infection in tropical splenomegaly.