bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Absorption of Sugars from the Human Buccal Cavity
Authors: Manning A. S. , Evered D. F. 
Published: August 2015

1. Certain sugars were transported across the buccal mucosa by a carrier-mediated mechanism.
2. The metabolic loss of sugars from the mouth in a 5 min test period was negligible.
3. The buccal mucosal transport process was stereospecific for d-glucose and l-arabinose.
4. The absorption of d-glucose, galactose and 3-O-methyl-d-glucose was at least partly dependent on the presence of sodium ions in the luminal fluid.
5. The transport of d-glucose was inhibited by galactose and 3-O-methyl-d-glucose, suggesting at least one common carrier system.
Density-Dependence of Maximal Expiratory Flow Rates before and after Bronchodilators in Patients with Obstructive Airways Disease
Authors: Wellman J. J. , McFadden E. R. , Ingram R. H. 
Published: August 2015

1. Gas-density-dependence of maximal expiratory flow rates (V̇max), defined as the ratio of V̇max while breathing helium/oxygen (80:20) to V̇max. while breathing air at the same lung volume, was examined in relation to other measurements of airways obstruction in patients with obstructive airways disease before and after administration of bronchodilators.
2. Seventeen patients showed a 45% or greater increase in specific conductance(sGaw) after bronchodilator therapy (group A) and thirteen patients demonstrated a lesser response (group B).
3. Before the administration of bronchodilators, the degree of obstruction in the two groups was not different as measured by lung volumes, sGaw, forced expiratory volume in 1 s, and flow rates high in the vital capacity; yet the maximal mid-expiratory flow rate and the degree of density-dependence were significantly lower in group B.
4. After bronchodilators, both groups of patients showed significant improvements in sGaw flow rates and lung volumes. However, group A patients showed a significant increase in density-dependence whereas group B patients did not.
5. Increased density-dependence after bronchodilators in the group A patients was associated with an increase in the computed resistance of the upstream segment with air and a decrease in resistance with helium/oxygen. These changes could be explained by a more mouthward movement of equal pressure points, and therefore a further increase in the relative contribution of the larger density-dependent airways to limitation of flow.
6. The fact that density-dependence was not altered after bronchodilators in the group B patients suggests that the site of limitation of flow did not change appreciably. The shift in the pressure—flow curve for the upstream airways was such that the computed resistance of these airways fell. Thus it appears that the airways comprising the upstream segment were dilated.
Effect of Age on Oxygen-Binding in Normal Human Subjects
Authors: Tweeddale P. M. , Leggett R. J. E. , Flenley D. C. 
Published: August 2015

1. Oxygen-binding, plasma and intra-erythrocytic pH, and haemoglobin, 2,3-diphosphoglycerate and inorganic phosphate concentrations were measured in sixty-two healthy non-smokers aged between 18 and 89 years.
2. P50 (oxygen tension at 50% oxygen saturation) expressed at plasma pH 7·40 and Pco2 5·33 kPa showed a positive correlation with age.
3. This correlation of P50 with age was closer when P50 was expressed at a constant intra-erythrocytic pH 7·20. On average P50 at intra-erythrocytic pH 7·20 increased from 3·59 kPa at 20 years to 3·96 kPa at 90 years of age.
4. 2,3-Diphosphoglycerate, inorganic phosphate, haemoglobin and mean corpuscular haemoglobin concentrations did not correlate with P50 or with age.
Relationship of Epicardial ST Segment Elevation to the Plasma Free Fatty Acid/Albumin Ratio during Coronary Occlusion in Dogs
Authors: Miller N. E. , Mjøs O. D. , Oliver M. F. 
Published: August 2015

1. Intravenous infusions of lipid-free albumin were used to lower the arterial non-esterified fatty acids (NEFA)/albumin ratio during coronary occlusion in dogs.
2. Reduction of the NEFA/albumin ratio was accompanied by proportionate reductions in myocardial uptake of NEFA and the degree of ST segment elevation in epicardial electrocardiographic recordings from the ischaemic zone. Aortic pressure and heart rate were unchanged.
3. Infusions of control albumin preparations had no effect on the NEFA/albumin ratio or ST segment elevation.
4. These observations support the proposition that the disturbance of cellular function during myocardial ischaemia is influenced by the degree of saturation of albumin-binding sites with NEFA and by their availability.
Potassium Transport across the Distal Colon in Man
Authors: Salas-Coll C. A. , Kermode J. C. , Edmonds C. J. 
Published: August 2015

1. The mechanism of potassium transport across human distal colon was investigated in twenty-two individuals without evidence of bowel disease, by using a dialysis method in conjunction with measurements of the transepithelial potential difference (p.d.).
2. Whether potassium was absorbed or secreted depended on its initial concentration in the lumen. The potassium net flux was approximately zero when the luminal potassium concentration was between 30 and 50 mmol/l.
3. Potassium secretion rate was little affected by sodium absorption rate, or by the luminal sodium concentration or by the osmolality of the luminal solution.
4. Potassium secretion rate was increased by partial substitution of other cations for sodium, in the descending order Li > NH4 > Rb > Na. Potassium concentration increased on average to over 80 mmol/l when lithium was in the lumen.
5. The observed transepithelial p.d. was inadequate to account for the intraluminal potassium concentrations attained, the discrepancy being most marked when ammonium or lithium was in the lumen. It is suggested that some potassium is secreted by the epithelial cells and this component of the total potassium flux into the lumen is increased when rubidium, ammonium or lithium is substituted for sodium.
Blood Flow through the Calf during Recovery from Fractures of the Lower Limb
Authors: Imms F. J. , Lorde D. A. , Prestidge S. P. , Thornton Christine 
Published: August 2015

1. Venous occlusion plethysmography has been used to measure the blood flow in the calves of nineteen patients with fractures of the lower limb and in six normal control subjects.
2. The resting blood flows were significantly higher in the injured legs than in uninjured legs, irrespective of the site of injury. Flows in the uninjured limbs were similar to those of the control subjects.
3. During reactive hyperaemia after 10 min arterial occlusion, the increase of flows in both legs of the patients was significantly lower than in the control subjects. Because of the increased resting flow, the maximal flow in the injured leg was similar to that in the control subjects, whereas the maximal flow in the uninjured leg was significantly lower than in the control group.
4. The changes in resting flow cannot be accounted for by a change in the proportions of tissues in the limb but they may be explained by an increase of the flow through muscle secondary to a relative increase in the mass of slow to fast muscle fibres.
The Arteriolar Lesions of Steroid Hypertension in Rats
Authors: Goldby F. S. 
Published: August 2015

1. The arteriolar lesions of rats with deoxycorticosterone (DOCA)—salt hypertension have been studied by colloidal carbon injection and light- and electron-microscopy.
2. Colloidal carbon particles enter the media of arterioles to form focal deposits when hypertension develops.
3. The focal lesions are similar to those seen after angiotensin infusion or renal artery constriction. They are characterized by endothelial damage and plasma deposition in the media.
4. Heavy deposition of carbon in the glomeruli of DOCA-treated animals was found to be caused by increased mesangial uptake and not by hypertensive vascular damage.
5. Angiotensin II concentrations fell during the development of hypertension and vascular lesions. The renin—angiotensin system was not implicated in the development of vascular damage in this form of hypertension.
Skin Collagen in Idiopathic Adolescent Scoliosis and Marfan's Syndrome
Authors: Francis M. J. O. , Sanderson M. C. , Smith R. 
Published: August 2015

1. Skin collagen from fifteen patients with idiopathic adolescent scoliosis, three with congenital scoliosis, and fourteen patients with various degrees of Marfan's syndrome has been examined.
2. The stability of a polymeric collagen fraction, extracted from the skin of these patients, to depolymerization, has been compared with that from thirty-one matched control subjects.
3. The mean polymeric collagen stability was significantly reduced (P < 0·01) in the group of fifteen patients with idiopathic adolescent scoliosis. The individual reductions in stability were greater in the younger patients and no reduction was found in two patients aged 19 years who had a mature skeleton.
4. The mean stability of polymeric skin collagen from the group of patients with Marfan's syndrome was not significantly abnormal, although there were individual low values.
5. Polymeric collagen of low stability was present in individual patients from each clinical group. Instability of collagen (from whatever cause) at a time of rapid growth may contribute to the high incidence of scoliosis in adolescent girls. In boys, adolescent scoliosis is less common and the maximum growth rate occurs at a time when collagen stability is less reduced.
Effect of Acupuncture on Bronchial Asthma
Authors: Yu D. Y. C. , Lee S. P. 
Published: August 2015

1. Needle acupuncture was performed at three sites in twenty patients in a clinical attack of bronchial asthma.
2. In all patients the symptoms of bronchoconstriction improved during the attacks when the correct site was stimulated, and in five patients wheezing was abolished.
3. Stimulation at the correct site produced a significant increase in the mean FEV1·0 (58%) and FVC (29%) but not in maximal mid-expiratory flow rate (MMFR; 76%), when compared with the findings before acupuncture, along with a significant fall in the Pa,co2 and an insignificant fall in Pa,o2. A mild tachycardia was also observed.
4. After acupuncture a greater improvement in FEV1·0, FVC and MMFR was produced by inhalation of isoprenaline.
5. No significant changes in FEV1·0, FVC, MMFR, pulse rate or arterial blood gas tensions occurred after acupuncture at control sites.
6. In four of the patients during clinical remission acupuncture was performed before and after histamine aerosol challenge, but there was no effect on either the severity or the duration of the histamine-induced bronchoconstriction.
7. It is concluded that acupuncture probably reduced the reflex component of the bronchoconstriction, but failed to influence direct smooth muscle constriction caused by histamine.
A Simple Method for the Differential Measurement of 125I and 3H by Liquid-Scintillation Spectrometry
Authors: Shand J. H. , Noble R. C. 
Published: August 2015

1. A method is described for the differential radioactivity counting of 125I and 3H in a liquid-scintillation spectrometer without a separate gamma counter.
2. The sample was contained in a polyethylene miniature vial placed centrally in a standard 20 ml glass scintillation vial containing a tin-loaded scintillant.
3. A direct measure of the 125I radioactivity at an efficiency of 30% was then obtained by radioactivity counting in the pre-set 3H window of a scintillation spectrometer. No counts for 3H radioactivity were registered at this stage because of the barrier to the passage of the low-energy β-particles provided by the wall of the polyethylene vial.
4. After mixing the sample and scintillant both 125I and 3H were detected at efficiencies of 73 % and 29% respectively. Subtraction of the 125I contribution from the combined radioactivity count rate then gave the net 3H count.
Analytical Subcellular Fractionation of Jejunal Biopsy Specimens: Methodology and Characterization of the Organelles in Normal Tissue
Authors: Peters T. J. 
Published: August 2015

1. Portions of closed jejunal biopsies were gently homogenized in isotonic sucrose or sorbitol and centrifuged at 800 g for 10 min to prepare a cell extract.
2. The extract was fractionated in a single-step procedure by isopycnic centrifugation on a continuous sucrose or sorbitol density gradient with the Beaufay automatic zonal rotor.
3. The subcellular organelles were located in the density gradient by assay of marker enzymes and previously unassigned enzymes were localized to particular organelles.
4. The following organelles were characterized by their modal equilibrium densities in sucrose density gradients: brush borders (1·21), peroxisomes (1·18), mitochondria (1·16), endoplasmic reticulum (1·16), basal—lateral membranes (1·12). At least three distinct populations of lysosomes with different modal densities and enzyme content were demonstrated.
5. This analytical fraction technique can be used to study the subcellular pathology of human jejunum.
Renin Release from Isolated Rat Glomeruli
Authors: Holdsworth S. , McLean A. , Morris B. J. , Dax E. , Johnston C. I. 
Published: August 2015

1. By the use of a mechanical graded sieving technique a high yield of isolated glomeruli has been obtained from rat kidney.
2. Microscopy and renin assay have shown the presence of renin-containing juxtaglomerular cells attached to these glomeruli.
3. The viability of isolated glomeruli has been confirmed by the ability of the cells to survive and divide in tissue culture and by their exclusion of vital dyes.
4. In superfusion after washout of extracellular renin, the glomeruli actively release constant amounts of renin over 3 h in direct proportion to the number superfused.
5. Decreasing sodium concentration from 140 to 110 mol/l with constant osmolarity of 305 mosmol/l stimulated renin release by a direct effect on juxtaglomerular cells.
6. Catecholamines stimulated renin release in vitro in proportion to the potency of their action on β-adrenoreceptors.
7. The system of superfusion of isolated glomeruli provides a technique for studying the influence of mediators leading to renin release acting directly on juxtaglomerular cells, independent of pressure change, tubular sodium, the sympathetic nervous system and circulating hormones.
Effects of Carotid Occlusion and Clonidine on Renin Secretion in Anaesthetized Dogs
Authors: Reid I. A. , Jones A. 
Published: August 2015

1. Sympathetic reflexes were activated by carotid occlusion in anaesthetized dogs in which changes in renal perfusion pressure were prevented. This produced a prompt and reversible increase in plasma renin activity.
2. Administration of clonidine decreased plasma renin activity, arterial pressure and heart rate and blocked the renin secretory and blood pressure responses to carotid occlusion.
3. These results support the hypothesis that the suppression of renin secretion by clonidine is a consequence of the decrease in sympathetic activity produced by this drug.
Evidence of Altered Permeability of the Erythrocyte Membrane for Sodium and Potassium ions in Spontaneously Hypertensive Rats
Authors: Postnov YU. V. , Orlov S. N. , Gulak P. V. , Shevchenko A. S. 
Published: August 2015

1. Erythrocyte membrane permeability to sodium and potassium ions was studied in 8–10 weeks spontaneously hypertensive rats (SHR, Kyoto/Wistar strain), normotensive Wistar and Sprague—Dawley rats.
2. The rate of 22Na efflux from the erythrocytes and the rate constant of Na/Na exchange were considerably greater in SHR than in normotensive Wistar and Sprague—Dawley rats. This difference remained the same in rats adrenalectomized 7 days before the experiment. The maximum difference in the constants was found when the sodium—potassium pump was blocked by ouabain.
3. The accumulation of 42K in the erythrocytes of SHR (the sodium—potassium pump being blocked) took place at a considerably slower rate, and the K+ wash-out into a potassium-free medium was faster than that in the normotensive Wistar and Sprague—Dawley rats.
4. These results indicate a higher permeability of the erythrocyte membrane of SHR for Na+ and K+, compared with normotensive Wistar and Sprague—Dawley strains. It is suggested that this may reflect a more widespread cell-membrane defect, which could serve as a general cause for activating the mechanisms maintaining high blood pressure.
Selective Hypoaldosteronism: A Study of Steroid Biosynthetic Pathways under Adrenocorticotrophin and Angiotensin II Infusion
Authors: Lebel M. , Grose J. H. 
Published: August 2015

1. The functional integrity of the adrenal cortex has been tested in a case of selective hypoaldosteronism by adrenocorticotrophin (ACTH) and angiotensin II (AII) infusion.
2. During ACTH infusion a normal functioning zona fasciculata was indicated by the impressive increase of the ACTH-dependent plasma steroids; the aldosterone response was moderate.
3. During AII infusion the plasma aldosterone response was blunted with an unexpected dose-dependent increase in pregnenolone, resulting in abnormal decreasing progesterone/pregnenolone ratios during the infusion, suggesting a slow-down in the conversion of pregnenolone into progesterone.
4. This defect, a probable consequence of chronic renin deficiency on the zona glomerulosa, could be a contributing factor to the hypoaldosteronism.
Peripheral and Central Catecholaminergic Neurons in Genetic and Experimental Hypertension in Rats
Authors: Grobecker H. , Saavedra J. M. , Roizen M. F. , Weise V. , Kopin I. J. , Axelrod J. 
Published: August 2015

1. Activity of peripheral and central catecholaminergic neurons was studied in spontaneously hypertensive rats (SHR) and deoxycorticosterone (DOCA)—salt hypertensive rats.
2. In young SHR (4 weeks) the plasma values of both noradrenaline and dopamine-β-hydroxylase activity were increased compared with those of normotensive rats of the Wistar/Kyoto strain. Total catecholamines (mostly adrenaline) were not significantly different.
3. In the adrenal glands of 2-weeks-old and 4-weeks-old SHR activities of tyrosine hydroxylase, dopamine-β-hydroxylase, phenylethanolamine-N-methyl transferase were decreased, compared to Wistar/Kyoto rats.
4. The adrenaline-forming enzyme was elevated in the A1 and A2 regions of the brain stem of 4-weeks-old SHR and in the A1 region of adult DOCA—salt hypertensive rats.
5. In the adrenal glands of adult DOCA—salt hypertensive rats tyrosine hydroxylase activity was increased.
6. These results implicate peripheral noradrenaline-containing neurons and central adrenaline-containing neurons in the development of genetic and experimental hypertension in rats.
Increase of Total Body Potassium and Decrease of Exchangeable Sodium after Long-Term Treatment with a β-Receptor-Blocking Agent (Prindolol) in Essential Hypertension
Authors: Brecht H. M. , Werner E. , Schoeppe W. 
Published: August 2015

1. The effect of long-term treatment with prindolol on blood pressure, total body potassium (Kt), exchangeable sodium (Nae) and plasma renin activity was investigated in twelve patients with essential hypertension.
2. Systolic and diastolic pressures were significantly reduced from 164/112 to 127/90 mmHg under basal conditions.
3. Before treatment Na. in patients with essential hypertension was significantly higher than in normotensive individuals. After an average of 16 weeks on prindolol Nae in patients with essential hypertension was significantly decreased, despite an average increase in body weight of 2 kg in the patients.
4. In contrast to the decrease in Nae, Kt was found to be significantly increased after long-term treatment with prindolol. Kt values of patients before and after prindolol, however, did not differ significantly from the corresponding sex- and age-dependent normal values.
5. Plasma renin activity was slightly diminished under basal and orthostatic conditions; the stimulatory effect of orthostasis was not abolished but reduced by prindolol.
6. It is suggested that the changes in sodium balance contribute to the anti-hypertensive effect of prindolol in patients with essential hypertension.
A Within-Patient Comparison of Bethanidine, Methyldopa and Propranolol in the Treatment of Hypertension
Authors: Prichard B. N. C. , Boakes A. J. , Graham B. R. 
Published: August 2015

1. A within-patient comparison showed that bethanidine, methyldopa and propranolol produced similar control of the blood pressure.
2. Unlike bethanidine, propranolol did not produce postural and exercise hypotension; methyldopa was intermediate in effect.
3. Overall side effects were of a similar incidence though there were differences in incidence of particular side effects.
A Comparison of the Effects of Chlorothiazide and of Metolazone in the Treatment of Hypertension
Authors: Hua A. S. P. , Kincaid-Smith Priscilla 
Published: August 2015

1. A cross-over study was done in twenty patients with hypertension to compare the effects of chlorothiazide (0·5 g twice daily) and metolazone (5 mg daily) in combination with other anti-hypertensive agents.
2. Compared with absence of diuretic therapy, chlorothiazide and metolazone both produced significantly lower blood pressures.
3. Blood pressures on metolazone tended to be lower than on chlorothiazide but this difference was not statistically significant.
4. Both diuretics significantly lowered serum potassium concentrations and total body potassium to a similar degree, but the serum potassium did not fall below the normal range in any patient and no potassium supplements were needed. No electrocardiographic changes suggestive of hypokalaemia were noted.
5. Small but significant increases in serum bicarbonate, calcium, urea and uric acid were observed with both diuretics.
6. Patient acceptance was excellent and no adverse effects were encountered.
Natriuresis in Rats Acutely Depleted of Chloride
Authors: Luke R. G. , Khanh B. T. , Schmidt R. D. , Galla J. H. 
Published: August 2015

1. Acute chloride depletion, without sodium depletion, was produced in rats by a single exchange peritoneal dialysis against sodium bicarbonate solution. Blood volume was restored after dialysis by infusion of salt-free albumin, and exogenous deoxycorticosterone and antidiuretic hormone were given.
2. Clearance studies in the period (3 h) after dialysis revealed no difference in the glomerular filtration rate or in the filtered sodium load between experimental and control rats but urinary sodium concentrations and absolute and fractional sodium excretion were significantly higher in the chloride-depleted group.
3. There was also a significant kaliuresis, increased urinary flow rate and diminished free water reabsorption. Urinary bicarbonate excretion increased to a variable degree but the major rise in anion excretion was ‘unmeasured’ (Na+ + K+ — [Cl− +HCO3− +PO43-]).
4. It is postulated that chloride depletion imposes limitations on sodium reabsorption in the ascending limb of the loop of Henle.
Effect of Propranolol on Blood Pressure and Renin in Renal Hypertension in the Rat
Authors: Fernandes M. , Onesti G. , Fiorentini R. , Gould A. B. , Kim K. E. , Swartz C. 
Published: August 2015

1. Propranolol was administered to groups of mature rats before and during the development of renal hypertension induced by ligation of the aorta between the renal arteries.
2. At a dose 10 μmol (3 mg) of propranolol/kg, administered by intraperitoneal injection, the onset and severity of hypertension were not affected, although plasma renin concentration was significantly lower than in the untreated hypertensive rats in the first 5 days after the operation.
3. With 200 μmol (60 mg) of propranolol/kg, administered in the drinking water, peak blood pressure 5 days after aortic ligation was lower than in the untreated control rats, but plasma renin concentration was no lower than with the smaller dose.
4. The development of severe hypertension despite reduction in plasma renin concentration on the low dose of propranolol suggests the participation of renal vasopressor factors other than renin in this model.
5. A higher dose of propranolol reduced the rise in plasma concentration to an equal extent but the rise of blood pressure at 5 days was also reduced, which supports this concept.