bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relation between the Excretion of Sodium and Water and the Perfusion Pressure in the Isolated, Blood-Perfused, Rabbit Kidney, with Special Reference to Changes Occurring in Clip-Hypertension
Authors: Thompson J. M. A. , Dickinson C. J. 
Published: August 2015

1. The sodium and water excretion rates of rabbit kidneys were studied when isolated and perfused at known pressure with blood from another normal anaesthetized rabbit. Studies at several different perfusion pressures confirmed that a small rise in perfusion pressure caused a large rise in sodium excretion and that the potential sodium-excreting ability of the isolated kidney was high. The curve obtained could be closely fitted by a quadratic equation which allowed an estimate to be made of the blood pressure below which no urine is formed, i.e. the ‘theoretical perfusion pressure threshold’. For normal kidneys this was 55·4 mmHg.
2. A group of rabbits had a silver clip applied to the left renal artery and, 3–6 weeks later, the eight most hypertensive animals were selected to provide their kidneys for perfusion. Both kidneys were perfused simultaneously. The clip on the left renal artery was removed immediately before perfusion and the cannula placed distal to the stenosis in the post-stenotic dilatation. The function curves of these kidneys were compared with the curves obtained from normal kidneys.
3. The untouched kidney contralateral to the clip was found to require a significantly higher perfusion pressure (71·7 mmHg) for it to achieve a given sodium excretion rate and, surprisingly, the clipped kidney showed a similar functional change (76·4 mmHg). In other words the positions of both function curves were shifted though their slopes were not much changed.
4. Both kidneys in single-clip-hypertension appear to adapt or reset their sodium excretory behaviour. The resetting in the untouched kidney allows hypertension to be sustained without undue sodium loss. Aldosterone probably contributes little to the resetting. We infer, indirectly, that the normal kidney may, to a significant extent, restrain sodium excretion by virtue of its sympathetic innervation. We also opine that the kidney cannot be assigned fixed intrinsic functional properties on which a renal sodium-handling theory of long-term blood pressure regulation can be firmly based.
The Clinical Measurement of Skeletal Blood Flow
Authors: Wootton R. , Reeve J. , Veall N. 
Published: August 2015

1. A new method for measurement of skeletal blood flow is described which depends on the complete extraction of 18F in a single passage through bone.
2. Plasma concentration and urinary excretion are measured over a 2 h period. The technique of impulse analysis is used to determine the initial transfer rate of 18F to bone and extravascular extracellular fluid (ECF). The ECF component is evaluated by using a second tracer (51Cr-EDTA or 82Br) and the bone transfer rate obtained by difference. The 51Cr-EDTA data also provide an estimate of glomerular filtration rate and enable a correction to be applied for urinary bladder retention when necessary.
3. Duplicate measurements of skeletal blood flow in eight normal male volunteers gave mean flows between 4·4 and 5·9% of blood volume/min, or about 4 ml min−1 100 g−1 of bone. The variation between normal subjects was least when the results were expressed as % of blood volume/min rather than ml/min, ml min−1 kg−1 or ml min−1 1·73 m−2 body surface area. The precision of the technique was estimated to be 16·4%.
4. Addition of 1·5% random noise to the input data resulted in an uncertainty of 8·5% in the measurement of skeletal blood flow, suggesting that improved precision depends on closer control of physiological variables.
5. In six patients with severe untreated Paget's disease of bone, skeletal blood flow was 8·4–15·3% of blood volume/min. The increase was significant in all cases.
6. The absorbed radiation dose is low, so that the measurement can be repeated.
Suppression of the Renin—Aldosterone System in Mild Essential Hypertension
Authors: Khokhar A. M. , Slater J. D. H. , Jowett T. P. , Payne N. N. 
Published: August 2015

1. Suppression of the renin—aldosterone system by expansion of the extracellular fluid volume with extra sodium and mineralocorticoid for 6 days was studied in nine young men with very mild essential hypertension and in ten normotensive young men.
2. Plasma renin activity, measured both supine and after 45° head-up tilt, and the renal excretion of aldosterone 18-glucuronide were similar in both groups. However, after expansion of the extracellular fluid volume, hypertensive patients showed much less suppression of both variables.
3. This difference persisted despite matching for an equivalent degree of expansion of the extracellular fluid volume as indexed by the change in body weight.
4. Administration of extra sodium and mineralocorticoid produced a greater proportional fall of renal aldosterone excretion than of plasma renin activity in both groups and this dissociation was significantly more marked in the hypertensive group.
5. We suggest that (i) a relative autonomy of the renin—aldosterone system may be relevant to the pathogenesis and/or perpetuation of essential hypertension and (ii) that the syndrome of low-renin hypertension is unlikely to be associated with ‘mineralocorticoid’ excess.
Polyuria Associated with an Antibody to Vasopressin
Authors: Bisset G. W. , Black Angela , Hilton P. J. , Jones N. F. , Montgomery Margaret 
Published: August 2015

1. A patient with polyuria in whom diabetes insipidus had been diagnosed was treated with Pitressin. Resistance to this therapy developed after 18 months and a circulating antibody to vasopressin was then demonstrated. Withdrawal of therapy led to a fall in titre of the antibody and an increase in maximal urinary concentration.
2. The antibody to vasopressin was associated with the IgA fraction of the serum immunoglobulins and its characteristics are described.
Arterial Oxygenation and Carbon Dioxide Tensions in the Production of Hypoxic Electroencephalographic Changes in Man
Authors: Rebuck A. S. , Davis C. , Longmire D. , Upton A. R. M. , Powles A. C. P. 
Published: August 2015

1. To investigate the interaction of hypoxaemia and blood Pco2 in the production of cerebral hypoxia, we studied six healthy men in whom acute progressive hypoxia was induced by using a re-breathing technique, while the Pco2 was kept constant.
2. At least two blood Pco2 tensions were studied in each subject. Arterial oxygen saturation was monitored continuously by ear oximetry, calibrated for each subject with arterialized blood. The onset of cerebral hypoxia was identified by the appearance of frontal slow waves (less than 5 Hz) in the electroencephalogram (EEG), which was recorded continuously with the bipolar 10–20 electrode placement system.
3. All subjects developed frontal slow waves during at least one experiment: the EEG changes were similar both within and among subjects, irrespective of the blood Pco2 value.
4. The arterial oxygen saturation at which slow-wave activity first occurred showed a significant inverse linear relationship to the Pco2 value at which hypoxia was induced.
5. The results imply that more profound levels of hypoxia are tolerated with high Pco2 values than with normal or low Pco2 values before hypoxic EEG changes become evident. Thus if eucapnia is maintained, EEG changes suggestive of cerebral hypoxia are unlikely to occur if arterial oxygen saturation remains above 75%.
The Distribution of [14C]Cholesterol in Muscle and Skin of Rhesus Monkeys after Intravenous Injection
Authors: Moutafis C. D. , Myant N. B. 
Published: August 2015

1. The specific radioactivity of [14C]cholesterol in plasma and in serial biopsies of muscle and skin was measured in Rhesus monkeys for 156 days after a single intravenous injection of [14C]cholesterol.
2. Analysis of the specific radioactivity—time curves in terms of a two-compartment system indicated that all the cholesterol of muscle is exchangeable with the plasma cholesterol and that local synthesis does not contribute significantly to the cholesterol in muscle.
3. Analysis of the curve for specific radioactivity of skin cholesterol suggested the presence of a small pool of cholesterol with slow turnover. A contribution to skin cholesterol from local synthesis could not be excluded.
Biochemical and Morphological Studies on Human Jejunal Mucosa Maintained in Culture
Authors: L'hirondel C. , Doe W. F. , Peters T. J. 
Published: August 2015

1. The combination of a wire-mesh support with the roller-tube technique is described as a procedure for the culture of human jejunal mucosa in vitro.
2. The technique has been applied to fragments (approximately 10 mg) of jejunal biopsies from both normal subjects and patients with coeliac disease.
3. The cultured tissue has been shown by radioautography to incorporate [3H]leucine into proteins of the villus epithelial cells and [3H]thymidine into nucleic acid, predominantly by the enterobiasis.
4. Although the tissue protein and DNA contents fall during culture, it was found that the combined tissue and medium DNA content remained constant during culture and may be used as a reference for enzyme and biochemical studies on cultured intestinal biopsies.
Some Properties of Human Platelet Monoamine Oxidase in Iron-Deficiency Anaemia
Authors: Youdim M. B. H. , Grahame-Smith D. G. , Woods H. F. 
Published: August 2015

1. Monoamine oxidase activity in platelets prepared from the blood of patients with iron-deficiency anaemia was significantly lowered when compared with that in platelets from normal subjects.
2. The Km values of the platelet enzyme for the substrates dopamine, 5-hydroxytryptamine, phenylethylamine and kynuramine were similar for the platelet enzyme from iron-deficient and normal groups.
3. Heat-inactivation studies showed that the platelet monoamine oxidase from iron-deficient subjects was more labile to this treatment, when compared with the platelet enzyme from normal subjects.
4. The sensitivity of platelet monoamine oxidase to the inhibitors, clorgyline and deprenil, was increased in iron-deficiency anaemia.
5. Binding studies with the 14C-binding irreversible monoamine oxidase inhibitor, deprenil, showed that the amount of enzyme capable of binding this inhibitor was lowered by 48% in platelets from iron-deficient patients when compared with platelets from normal subjects.
6. The results show that there is a lowered amount of active enzyme in platelets from iron-deficient subjects. It is suggested that iron is necessary either for the synthesis of monoamine oxidase apoenzyme or is a cofactor for an enzyme which attaches flavin—adenine dinucleotide covalently to the monoamine oxidase apoenzyme.
Absorption of Galactose by the Rat Small Intestine in Vivo: Proximal—Distal Kinetic Gradients and a New Method to Express Absorption Per Enterocyte
Authors: Batt R. M. , Peters T. J. 
Published: August 2015

1. The absorption in vivo of d-galactose by the rat small intestine has been examined in proximal jejunum and distal ileum by use of a recirculation—perfusion technique.
2. Multiple sequential perfusions over 4 h produced no subsequent functional or morphological damage in the perfused segments.
3. Absorption of galactose from 8 and 64 mmol/l solutions was found to be independent of flow rate over the range 1·0–6·5 ml/min.
4. Galactose absorption in both the jejunum and the ileum exhibited saturation kinetics of the Michaelis—Menten type, and phlorrhizin sensitivity. Sorbose was only absorbed minimally. These observations demonstrate that galactose is absorbed by carrier-mediated transport and that there is no significant passive diffusive component in vivo.
5. Under the stated experimental conditions, the maximum absorptive capacity was 4·5 times greater in the jejunum than in the ileum. The Michaelis constant for galactose was higher in the jejunum than in the ileum.
6. Enterocytes were isolated from perfused segments and quantified by DNA assay with a correction for yield. In this manner, the absorptive capacity per enterocyte was calculated.
7. The maximum absorptive capacity per enterocyte was 3·5 times greater in the jejunum than in the ileum.
The Effect of Active Immunization against Aldosterone on the Colonic Potential Response and Sodium Excretion in Rabbits
Authors: Lennane R. J. , Stockigt J. , Peart W. S. 
Published: August 2015

1. A group of rabbits was actively immunized against aldosterone and their subsequent response to infused aldosterone and to dietary sodium restriction was compared with that of a control group.
2. Colonic electrical potential difference (CP) was used as an index of relative mineralocorticoid activity in both groups of animals.
3. Infusion of aldosterone produced a rise in CP to a maximum of −50 to −70 mV at rates of infusion of 55–270 pmol min−1 kg−1. In contrast, the immune group showed no change until infusion dose rates of 2700 pmol min−1 kg−1 were used.
4. During dietary sodium restriction, CP increased in normal rabbits to a significantly greater degree than in immune animals although cumulative urinary sodium losses were the same in both groups.
5. The ability of the immune animals to remain in sodium balance despite physiological aldosterone blockade suggests that aldosterone is not an essential component of their sodium-conservation mechanisms.
Functional and Biochemical Evidence of Damage to Enterocytes Induced by Triparanol: Role of Lysosomes and the Effect of a Gluten-Free Diet
Authors: Soulé J.-C. , Neale G. , Peters T. J. 
Published: August 2015

1. Functional and biochemical studies were performed on the small intestine of control rats, and the results were compared with similar studies on animals given triparanol at a dosage of 0114 mmol/kg daily for 10 days. The animals given triparanol were fed with either standard rat food or a gluten-free diet.
2. By using a recirculating-perfusion technique in vivo, it was shown that absorption of galactose from an 8 mmol/l solution was impaired in the ileum but not in the jejunum of the triparanol-treated rats.
3. Assays of marker enzymes for the principal subcellular organelles were performed on isolated jejunal and ileal enterocytes. In the ileum there was a striking decrease in lysosomal enzyme activities and a smaller but significant decrease of lactate dehydrogenase, catalase and malate dehydrogenase activities. In the jejunum there was no significant change in the activities of these enzymes.
4. Measurements of lysosomal integrity indicated that ileal lysosomal fragility was markedly increased and that jejunal lysosomes were affected to a much smaller extent.
5. These effects of triparanol could not be ameliorated by feeding with a gluten-free diet.
Cystinuria: A New Genetic Variant
Authors: Stephens A. D. , Perrett D. 
Published: August 2015

1. A family is reported with an unusual type of cystinuria.
2. The propositus presented with a cystine renal stone; the renal tubular reabsorption of cystine was grossly abnormal but the tubular reabsorption of ornithine, lysine and arginine was only slightly less than normal.
3. One of the children of the propositus excreted cystine and lysine in increased amounts typical of type II heterozygotes for cystinuria.
4. The renal transport defect in this family may represent one end of the spectrum of cystinuria or it may be a form akin to isolated hypercystinuria.
Effect of Vasopressin on Uric Acid Excretion: Evidence for Distal Nephron Reabsorption of Urate in Man
Authors: Meisel A. , Diamond H. 
Published: August 2015

1. When changes in urine flow rate were induced by vasopressin administration in eight subjects, urate excretion decreased by a mean of 14% and was positively correlated with urine flow rate (r = 0·88, p < 0·01). The effect of vasopressin on urate excretion was not influenced by prior changes in extracellular fluid volume.
2. Mannitol administration in a dose sufficient to prevent vasopressin-induced alterations in urine flow rate blocked the effect of vasopressin on urate excretion.
3. Alterations in urate excretion produced by changes in extracellular fluid volume could be distinguished from the urate-retaining effect of vasopressin-mediated decrease in urine flow. Urate retention after vasopressin was entirely attributed to a decrease in pyrazinamide-suppressible urate excretion, consistent with either decreased secretion or enhanced post-secretory reabsorption of urate.
4. Since diminished urine flow rate in the distal part of the nephron is more likely to lead to enhanced reabsorption of urate, these results provide additional evidence for urate reabsorption in the distal part of the nephron.
Effects of P-Chlorophenoxyisobutyrate on Free Fatty Acid Mobilization from Canine Subcutaneous Adipose Tissue In Situ
Authors: Miller N. E. , Mjøs O. D. , Oliver M. F. 
Published: August 2015

1. The mechanism whereby p-chlorophenoxyisobutyrate (CPIB) lowers plasma non-esterified fatty acid concentrations has been studied in dogs by measuring the associated changes in adipose tissue metabolism.
2. CPIB lowered arterial concentrations of non-esterified fatty acids during isoprenaline infusion by a mean value of 41%.
3. This was accompanied by a proportionate decrease (45%) in the release of non-esterified fatty acids from subcutaneous adipose tissue in situ, and by a lesser reduction (22%) in that of glycerol.
4. Adipose tissue blood flow was unchanged by CPIB.
5. These findings indicate that the lowering effect of CPIB on non-esterified fatty acid concentrations derives principally from decreased mobilization rather than from increased tissue uptake of the fatty acids, and that this reflects both inhibited lipolysis and enhanced re-esterification of the fatty acids in adipose tissue.
The Effect of Cellulose Phosphate on Plasma and Urinary Magnesium at Different Levels of Parathyroid Function in Man
Authors: Parfitt A. M. 
Published: August 2015

1. Previously published data obtained by magnesium infusion in man were found to conform to a Tm/glomerular filtration rate (GFR) model on the assumption of 80% diffusibility of plasma magnesium. The lower limit of Tm,Mg/GFR was 625 μmol/l.
2. Previously published data concerning the effect of cellulose phosphate on magnesium metabolism in normal subjects, patients with latent hypoparathyroidism and patients with primary hyperparathyroidism were found to conform to the same model, with the same lower limit for Tm,Mg/GFR for all three levels of parathyroid function.
3. The threshold for magnesium excretion is sharper with less ‘splay’ than for phosphate, but as for phosphate it is close to the normal blood concentration.
4. Because of the geometrical relationship between different methods of presentation of data, at a constant value for Tm,Mg/GFR changes in magnesium load or in GFR automatically produce changes in fractional magnesium clearance. This is the explanation for the increase in fractional magnesium clearance which occurs with diminishing renal function.
5. Renal conservation of magnesium is a passive consequence of the fall in plasma magnesium. There was no evidence of augmented tubular reabsorption of magnesium in response to magnesium deprivation in any of the three groups of subjects.
6. The tubular reabsorption of magnesium was not altered detectably by a moderate deficiency or excess of parathyroid hormone. Changes in parathyroid hormone secretion are probably not concerned in normal magnesium homeostasis.
The Kinetics of Efflux of 5,5-Dimethyl-2,4-Oxazolidinedione (DMO) from the Myocardium
Authors: Poole-Wilson P. A. 
Published: August 2015

1. The efflux of 14C-Iabelled 5,5-dimethyl-2,4-oxazolidinedione (DMO) from the myocardium of the rabbit has been studied. The perfusate pH was 7·38.
2. The effluent curve is complex and appears to be the resultant of movement between at least four compartments.
3. The first two probably represent intravascular and extracellular compartments; the last two have smaller rate constants and may represent intracellular spaces. Intracellular pH (pH1) calculated from the effluent curve was 7·23 ± 0·05. pH1 estimated from the steady-state distribution volume of DMO was 7·28 ± 0·02.
4. The existence of two intracellular compartments suggests that DMO is not homogeneously distributed in the myocardium. It is suggested that the apparent greater buffering capacity of cardiac than skeletal muscle can be explained by the greater number and volume of mitochondria in the myocardium, compartmentalization of DMO and assumptions inherent in the DMO method for the measurement of pH1.
Low-Density Lipoproteins in Patients Homozygous for Familial Hyperbetalipoproteinaemia
Authors: Mills G. L. , Taylaur C. E. , Chapman M. J. 
Published: August 2015

1. The low-density lipoproteins (LDL; density 1·007–1·063 g/ml) from two patients homozygous for familial hyperbetalipoproteinaemia have been submitted to chemical and physicochemical analysis.
2. The presence of an anomalous lipoprotein with a low proportion of triglyceride and a raised proportion of cholesterol has been confirmed.
3. In one patient, this lipoprotein accounted for about 85% of the LDL, but in the second, the amount varied from about 85% to a point at which it could not be detected among the coexisting normal lipoproteins.
4. The protein moiety of this anomalous LDL has effectively the same amino acid composition as that derived from the LDL of healthy subjects.
5. The proportions of carbohydrate, phospholipid and fatty acids could not be reliably distinguished from those of normal LDL.
6. The molecular weight and diffusion constant of the abnormal lipoprotein, even in the purest preparation, were close to the values determined for normal LDL of similar flotation rate.
Primary malignant nephrosclerosis
Authors: Bohle A. , Grund K. E. , Helmchen U. , Meyer D. 
Published: August 2015

1. As proposed by Schürmann & MacMahon (1933), we suggest that two types of malignant nephrosclerosis exist.
2. In the type called primary malignant nephrosclerosis, renal vascular lesions precede hypertension.
3. In the second type, called secondary malignant nephrosclerosis, renal vascular lesions are considered to be the consequence of malignant hypertension.
Indirect Evidence of Calcitonin Secretion in Man
Authors: Caniggia A. , Gennari C. , Vattimo A. , Nardi P. , Nuti R. 
Published: August 2015

1. The effect of calcitonin, a large amount of calcium given orally, pentagastrin and glucagon on plasma 47Ca radioactivity curves in subjects pretreated with 47Ca was examined.
2. A sudden increase of plasma radioactivity after intravenous administration of calcitonin and pentagastrin and after the oral calcium load was observed in normal subjects; the intravenous infusion of glucagon was less effective.
3. Two thyroparathyroidectomized patients who responded to the calcitonin infusion did not respond to the oral calcium load.
4. These data may be considered to offer indirect evidence of endogenous calcitonin secretion in man.
Gas Exchange during Exercise in Healthy People: I. the Physiological Dead-Space Volume
Authors: Bradley Christine A. , Harris E. A. , Seelye Eve R. , Whitlock R. M. L. 
Published: August 2015

1. Physiological dead-space volume (VD) was measured in twenty-four healthy men and women aged from 20 to 71 years, at rest and at two rates of work on a treadmill, whilst breathing air and breathing oxygen.
2. The effect of correction of arterial carbon dioxide tension (Pa,co2) to pulmonary capillary temperature on the resulting value for VD was investigated. We find that the effect is substantial and that a correction should be made.
3. Equations have been derived for the prediction of normal VD during exercise. The best prediction was given by a regression on height, age, carbon dioxide output, ventilation and respiratory frequency, with an upper 95% confidence limit of +81 ml.