bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the Carbohydrate Content of Mucus Glycoproteins from Normal and Diseased Colons
Authors: Clamp J. R. , Fraser G. , Read A. E. 
Published: August 2015

1. Mucus samples obtained from colectomy colons from 10 patients with ulcerative colitis and four patients with Crohn's disease of the colon, together with samples from 10 normal postmortem colons, have been studied.
2. Two glycoprotein fractions were isolated from mucosal scrapings by gel-permeation chromatography. The high-molecular-weight fraction consisted largely of mucus glycoproteins and was further purified to the glycopolypeptides. The low-molecular-weight fraction contained a glycoprotein with a high mannose content. The carbohydrate content of both the mucus glycoprotein and glycopolypeptide fractions were significantly reduced in active colitis.
3. Oligosaccharides were prepared from the mucus glycoprotein material. In the normal material more than half the units contained eight or more monosaccharide residues, whereas in the disease material the bulk of the units were smaller than this.
Effects of Clonidine on Aortic Pressure-Diameter and Elastic Stiffness-Stress Relations in Anaesthetized Rabbits
Authors: Friggi A. , Bodard H. 
Published: August 2015

1. The effects of clonidine on the aortic pressure-diameter relationship were studied in anaesthetized rabbits by means of an ultrasonic dimension technique. Midwall aortic stress and aortic elastic modulus were calculated.
2. In spite of a significant decrease in mean aortic blood pressure, aortic diameter was slightly but not significantly increased after intravenous clonidine injection (25 μg/kg body wt., intravenously over 30 s).
3. Midwall aortic stress was decreased when compared at the same aortic radius and aortic elastic modulus was increased when compared at a common blood pressure level. However, when aortic elastic modulus was plotted as a linear function of the stress, no difference was observed before and after clonidine.
4. The results suggest that the pressure-diameter changes induced by clonidine were primarily reflecting the mechanical changes in the aortic wall due to changes in smooth muscle tension. Furthermore it seems that the elastic modulus of the aorta tends to remain constant by adaptive changes in the aortic wall which over-ride the concurrent geometrical changes to maintain a level of elasticity consistent with the degree of aortic stress.
Plasma and Interstitial Volumes in Essential Hypertension: Relationship to Blood Pressure
Authors: Bing R. F. , Smith A. J. 
Published: August 2015

1. Plasma and interstitial fluid volumes have been measured simultaneously in men with uncomplicated and untreated essential hypertension.
2. Plasma volume (Evans blue) was reduced in essential hypertension and correlated inversely with blood pressure.
3. Interstitial fluid volume, derived from bromine space and plasma volume, was also reduced in essential hypertension and correlated inversely with blood pressure. The mean reduction in both plasma and interstitial fluid volumes was 6–7%.
4. There is no evidence for volume expansion in essential hypertension and the relationship between plasma and interstitial fluid volumes is preserved. The contraction of plasma and interstitial fluid volumes is most likely to reflect a natriuresis and diuresis secondary to the raised renal perfusion pressure, and sodium retention is unlikely to be a primary event in essential hypertension.
Effect of β-Adrenoceptor Blockade on Exercise Performance and Metabolism
Authors: Lundborg PER , Åström H. , Bengtsson C. , Fellenius E. , Von Schenck H. , Svensson L. , Smith U. 
Published: August 2015

1. Carbohydrate and lipid metabolism and the capacity to perform prolonged submaximal physical exercise were studied in six young healthy subjects treated in a randomized double-blind fashion for 2 days with either placebo, the non-selective β-adrenoceptor antagonist propranolol (80 mg b.i.d.) or the cardioselective agent metoprolol (100 mg b.i.d.). On day 3, 1 h after the last dose, the subjects exercised for 30 min periods followed up 10 min rest up to the point of exhaustion.
2. The capacity to perform exercise was decreased with both β-adrenoceptor antagonists. However, at an equal degree of β1-adrenoceptor blockade, all subjects could exercise for a longer period of time on the cardioselective agent as compared with the non-selective drug.
3. Blood glucose levels decreased during exercise irrespective of the type of treatment, but the attenuation occurred most rapidly on propranolol. At exhaustion the average non-esterified fatty acid levels had increased 256% on placebo, 148% on metoprolol and 65% on propranolol. A significant positive correlation was found between changes in non-esterified fatty acid levels during exercise and total working time. It is concluded that β-adrenoceptor blockade diminishes the capacity for prolonged submaximal exercise at least in part by reducing the availability of substrates to the working muscles.
Dietary Sodium, Erythrocyte Sodium Concentration, Sodium-Stimulated Lithium Efflux and Blood Pressure
Authors: Trevisan M. , Cooper R. , Ostrow D. , Miller W. , Sparks S. , Leonas Y. , Allen A. , Steinhauer M. , Stamler J. 
Published: August 2015

1. There was a significant positive relationship between sodium-stimulated lithium efflux and systolic blood pressure (r = 0.512) in erythrocytes of black school children. Weight was also positively and significantly correlated with blood pressure. Although erythrocyte sodium concentration did not bear any significant relationship with blood pressure, it did bear significant inverse relationship with urinary sodium excretion.
2. High-school students were randomly assigned to either the experimental or the control group. In the former a reduction of about 70% in salt intake was achieved. After 24 days, the erythrocyte sodium concentration was significantly reduced in the experimental group. A non-significant decline in systolic blood pressure was observed in the experimental group; no change was detectable in the control group for either erythrocyte sodium concentration or systolic blood pressure.
A Comparison of Radioactive Calcium Absorption Tests with Net Calcium Absorption
Authors: Marshall D. H. , Nordin B. E. C. 
Published: August 2015

1. Four different methods of calculating calcium absorption by radioactive calcium procedures have been compared with each other and with net calcium absorption in calcium-balance studies in 100 consecutive studies on 71 patients.
2. All four isotope procedures yielded highly significant correlations with net calcium absorption derived from the balance studies, but there was little to choose between the validity of the double-isotope and single-isotope procedure judged by these criteria.
3. The rate of calcium absorption calculated from one or other isotope procedure correlated better with net calcium absorption than did the fraction of the radioactive calcium absorbed.
4. The measurement of plasma radioactivity 1 h after single-isotope administration, corrected for body weight, proved almost as useful as the more complex procedures but would be expected to underestimate calcium absorption in states of very high bone turnover.
Studies on the Role of a Humoral Sodium-Transport Inhibitor and the Anteroventral Third Ventricle (AV3V) in Experimental Low-Renin Hypertension
Authors: Pamnani M. B. , Buggy J. , Huot S. J. , Haddy F. J. 
Published: August 2015

1. Recent studies in our laboratory suggest that Na+,K+-dependent-ATPase and Na+—K+ pump activities are reduced in cardiovascular muscle of animals with experimental low-renin hypertension.
2. We here show that these abnormalities are associated with a heat-stable ouabain-like agent in the plasma.
3. In the volume-expanded rat, an anteroventral third ventricle (AV3V) lesion decreases the level of the ouabain-like humoral factor and increases vascular Na+—K+ pump activity. These findings suggest that the humoral ouabain-like factor originates in or is influenced by the AV3V area of the brain and may help to explain why the AV3V lesion prevents or reverses one-kidney renal and one-kidney, DOCA—salt hypertension in rats.
Contribution of Stenosis Resistance to the Rise in total Peripheral Resistance during Experimental Renal Hypertension in Conscious Dogs
Authors: Anderson W. P. , Korner P. I. , Angus J. A. , Johnston C. I. 
Published: August 2015

1. Mild, moderate and severe renal artery stenosis was induced in uninephrectomized conscious dogs by inflating a renal artery cuff to lower distal pressure to 60, 40 or 20 mmHg respectively. The renal artery was narrowed progressively over the next 3 days by further inflation of the cuff to relower the distal renal artery pressure to the initial values.
2. Graded progressive stenosis produced graded progressive rises in blood pressure, plasma renin activity and total renal resistance to flow over the 3 day period, followed by a return to control values 24 h after cuff deflation.
3. The rise in total renal resistance to flow was almost entirely due to the stenosis, with only small changes occurring in renal vascular resistance.
4. in moderate and severe stenosis cardiac output did not alter significantly and thus increases in blood pressure were due to increases in total peripheral resistance. in these groups the resistance to blood flow of the stenosis accounted respectively for about 36 and 26% of the rises in total peripheral resistance. Vasoconstriction of the other non-renal vascular beds accounted for the remainder of the increase in total peripheral resistance.
5. in mild stenosis the changes in both cardiac output and total peripheral resistance were variable and not statistically significant. in this group the rise in stenosis resistance was compensated by vasodilatation of the non-renal vascular beds.
6. in all groups rises in plasma renin activity and blood pressure correlated with the haemodynamic severity of the stenosis.
7. Thus the resistance to blood flow of the moderate and severe renal artery stenoses accounted for one-quarter to one-third of the increases in total peripheral resistance. The remainder of the increase in total peripheral resistance was due to vasoconstriction of nonrenal beds.
Urinary Excretion of Bile Acids in Cholestasis: Evidence for Renal Tubular Secretion in Man
Authors: Corbett C. L. , Bartholomew T. C. , Billing Barbara H. , Summerfield J. A. 
Published: August 2015

1. the apparent renal clearance of intravenously injected [14C]glycocholate and [3H]-chenodeoxycholate-3-sulphate was estimated in 22 patients with cholestasis. the degree of protein binding of the isotopes in serum from these patients was determined. the effects of pharmacological agents, changes in urine flow rate and pH on renal clearance were studied.
2. the mean renal clearance of [14C]glycocholate was 1.7 ± 0.4 ml/min (mean ± sem), and that of [3H]chenodeoxycholate-3-sulphate was 6.4 ± 0.9 ml/min. [14C]Glycocholate was 80.1% protein bound and [3H]chenodeoxycholate-3-sulphate 96.5% protein bound.
3. Comparisons of the observed clearance rates with those calculated on the basis of glomerular filtration of the unbound fraction suggest that whereas [14C]glycocholate is predominantly reabsorbed by the renal tubules, [3H]chenodeoxycholate-3-sulphate appears in the urine mainly as the result of tubular secretion.
4. Probenecid, ethacrynic acid, frusemide and bendrofluazide decreased the clearance of both bile acids, implying competition for secretion via the proximal tubular organic acid secretory pathway between these compounds and bile acids.
5. Passive non-ionic diffusion does not seem to be an important mechanism in the renal excretion of bile acids as changes in urine flow rate and pH did not influence bile acid clearance.
6. A greater affinity of the proximal tubular organic acid secretory pathway for sulphated than for non-sulphated bile acids may explain the higher observed renal clearance rate of sulphated bile acids.
Complex Competitive and Non-Competitive Inhibition of Rat Lung Angiotensin-Converting Enzyme by Inhibitors Containing Thiol Groups: Captopril and SA 446
Authors: Mendelsohn F. A. O. , Csicsmann J. , Hutchinson J. S. 
Published: August 2015

1. The kinetics of the inhibitory action of four different angiotensin-converting enzyme inhibitors was evaluated in vitro with rat lung enzyme and the substrate hippuryl-histidyl-leucine.
2. Enzyme velocity against substrate concentration curves were fitted directly to hyperbolae by a weighted least squares iterative method to obtain apparent values of Km, Vmax. and K/V at each concentration of inhibitor.
3. The inhibitory constants K1 and Kí were obtained by weighted linear regressions of K/V against i and 1/V against i respectively.
4. Teprotide was the least potent inhibitor with a K1 of near 20 nmol/l whereas captopril (SQ 14 225) and SA 446 were both approximately 10 times and MK 421 approximately 20 times more potent.
5. Two inhibitors which lacked thiol groups [teprotide or SQ 20 881 and N-(1-S-1-carboxy-3-phenylpropyl)-l-Ala-l-Pro or MK 421] produced a purely competitive pattern of inhibition with increased apparent Km but no change in apparent Vmax.
6. Two inhibitors containing thiol groups [captopril or SQ 14 225 and 2-(2′-hydroxyphenyl)-3-(3-mercaptopropanoyl)-4-thiazolidine carboxylic acid or SA 446] both produced a mixed competitive and non-competitive pattern of inhibition with increased apparent Km and decreased Vmax.
7. It is possible that thiol-containing inhibitors might produce non-competitive inhibition of converting enzyme by forming strong bonds with zinc near the active site of the enzyme.
Effect of Angiotensin II and Converting Enzyme Inhibitor (Captopril) on Blood Pressure, Plasma Renin Activity and Aldosterone in Primary Aldosteronism
Authors: Mantero F. , Fallo F. , Opocher G. , Armanini D. , Boscaro M. , Scaroni C. 
Published: August 2015

1. Patients with idiopathic hyperaldosteronism (IHA) show a response of aldosterone to posture which is not present in patients with aldosterone-producing adenoma (APA). We have determined whether this could be explained by a different sensitivity to angiotensin II.
2. Angiotensin II was infused in gradually increasing doses in six patients with APA and in seven patients with IHA. No changes in aldosterone concentration were found at the end of each period in APA, whereas there was a significant increase in IHA; blood pressure rose by a similar extent in both groups.
3. In order to evaluate the role of endogenous angiotensin II, captopril, a converting enzyme inhibitor, was administered to six patients with APA and five patients with IHA at a dose of 75 mg/day for 1 week. There was a significant fall of mean blood pressure in IHA and only minimal changes in APA. Plasma renin activity and plasma and urinary aldosterone were unchanged in APA. In IHA there was a small increase in upright plasma renin activity and a slight decrease in both plasma and urinary aldosterone, but these changes were not significant.
4. These findings further support the idea that idiopathic hyperaldosteronism is a clinical state different from that occurring in primary aldosteronism due to adenoma, and may be more closely related to essential hypertension.
Optimum Tryptic Activation of Inactive Renin in Human Plasma is Independent of Endogenous Anti-Tryptic Activity
Authors: Rappelli Alessandro , Dessi'-Fulgheri Paolo , Madeddu Paolo , Meloni Franca , Fiori Caterina , Sanna Giovanni , Glorioso Nicola 
Published: August 2015

1. Plasma samples from 31 normal subjects were treated (at 4°C, pH 7.0, for 2 min) with different concentrations of trypsin (500, 1000, 2000, 3000 and 4000 μg/ml) in order to assess which concentration yielded the maximum activation of inactive renin.
2. Endogenous antitryptic activity was also measured in all samples; the mean value ± sd (in μg of trypsin inhibited by 1 ml of plasma) was 953 ± 550 μg/ml (range 34–1800 μg/ml).
3. In the entire group of subjects the values of trypsin-activated renin measured with trypsin at 2000 μg/ml were significantly higher than those obtained with lower or higher trypsin concentrations.
4. With subjects divided into subgroups according to their endogenous anti-tryptic activity, the maximum yield of activation was reached with trypsin at 2000 μg/ml.
5. No significant correlations were found between single values of active, inactive or trypsin-activated renin and the corresponding levels of endogenous anti-tryptic activity. However, a weak but significant correlation (r = 0.39, P &lt; 0.05) was found between single values of anti-tryptic activity and the corresponding percentage of activation of inactive renin.
6. Thus the maximum activation of inactive renin at 4°C for 2 min is obtained with trypsin at 2000 μg/ml independently of the corresponding endogenous anti-tryptic activity. It is not excluded that the content of protease inhibitors in human plasma might affect the proportion in vivo of circulating active and inactive renin.
Derivation of Neutral Antihypertensive Lipid from Renal Venous Effluent in Rats
Authors: Muirhead E. E. , Byers L. W. , Pitcock J. A. , Desiderio D. M. , Brooks B. , Brown Peggy , Brosius W. L. 
Published: August 2015

1. The antihypertensive neutral renomedullary lipid (ANRL) is a natural product derived from fresh renal medulla and from venous blood.
2. ANRL appears to be an antihypertensive hormone secreted when the kidney exerts its antihypertensive function after unclipping.
3. The kidney appears to be the main source of ANRL, maintaining a basal rate of secretion of ANRL.
4. The kidney of the one-kidney, one-clip hypertensive rat appears to secrete an inappropriate amount of ANRL. Thus a deficiency of the secretion of the antihypertensive hormone may play a role in the pathogenesis of the one-kidney, one-clip hypertensive model.
5. Degranulation of the renomedullary interstitial cells (RIC) occurs as the kidney exerts its antihypertensive action after unclipping, supporting these cells as the source of ANRL.
6. Channels between collecting duct cells may encourage water reabsorption while the clip is in place; conversely, the closure of these channels when the clip is removed may encourage the diuresis that is observed.
Influence of Family History of Hypertension on the Relationships between Blood Pressure, Body Weight, Electrolyte Metabolism, Renin, Prolactin and Parathormone
Authors: Wessels F. , Hoffmann D. , Wagner H. , Zumkley H. 
Published: August 2015

1. The influence of family history of hypertension on the relationships between blood pressure, relative body weight, sodium/creatinine ratio of the 24 h urine, plasma renin activity and the plasma concentration of prolactin and parathormone were examined in 102 healthy male students.
2. Grouping together results from all students showed significant positive correlations between systolic blood pressure and prolactin, parathormone as well as relative body weight, between plasma renin activity and prolactin and a significant negative correlation between plasma renin activity and sodium/creatinine ratio of the 24 h urine.
3. By dividing the students into two groups according to their family history of hypertension we could demonstrate in those with family history of hypertension a highly significant positive correlation between mean blood pressure and sodium/creatinine ratio of the 24 h urine and an improvement of the correlations between systolic blood pressure and prolactin and between sodium/creatinine ratio of the 24 h urine and plasma renin activity. In students without family history of hypertension these relationships were no longer detectable. In the students without family history of hypertension the correlations between systolic blood pressure and relative body weight as well as between plasma renin activity and prolactin gained substantially in significance. In students with positive family history of hypertension these correlations could no longer be demonstrated. The correlations between systolic blood pressure and parathormone remained unaffected by family history of hypertension.
4. The results suggest that a genetic predisposition to essential hypertension is able to intensify the blood pressure effect of Na intake and of prolactin, which, besides its function as a sex hormone, is presumed additionally to be able to retain salt. However, the positive relationship between body weight and blood pressure, as well as between plasma renin activity and prolactin, the significance of which increases greatly in subjects without family history of hypertension, appears to be lost as the result of the increased sensitivity to salt in positive family history of hypertension.
Hypertension in the Elderly: Haemodynamic, Fluid Volume and Endocrine Findings
Authors: Messerli F. H. , Glade L. B. , Dreslinski G. R. , Dunn F. G. , Reisin E. , MacPhee A. A. , Frohlich E. D. 
Published: August 2015

1. Systemic and renal haemodynamics, intravascular volume, circulating catecholamines and plasma renin activity were measured in 18 patients with established essential hypertension who were older than 60 years of age. Each patient was matched with respect to mean arterial pressure, body surface area, race and sex with a patient that was younger than 42 years of age.
2. When compared with the younger group, elderly patients had a lower cardiac output, impaired myocardial reserve, lesser aortic elasticity, higher total peripheral resistance, more contracted intravascular volume and higher circulating noradrenaline levels.
3. Similar effects of age, although less pronounced, have been reported in normotensive subjects. We conclude that essential hypertension is a pathophysiological process that seems to accelerate the natural physiological haemodynamic, fluid volume and endocrine processes of aging.
Percutaneous Transluminal Dilatation or Surgery in the Management of Renal Vascular Hypertension?
Authors: Grim C. E. , Yune H. Y. , Weinberger M. H. , Donohue J. P. 
Published: August 2015

1. Twelve patients with renal artery stenosis due to fibromuscular disease (FMD) were treated with percutaneous transluminal dilation (PTD) and their results (first year) compared with those for 26 patients treated with attempted renal artery bypass. The cumulative probability of cure at 1 year was 0.67 for PTD and 0.36 for surgery (P = N.S.) in patients with FMD. The cumulative probability of being improved or cured was 0.92 for PTD and 0.88 for surgery.
2. Eighteen patients with renal artery stenosis due to atherosclerosis were treated with PTD and their results compared with those of 28 patients treated by surgery. The cumulative probability of cure at 1 year was 0.11 for PTD and 0.17 for surgery (P = N.S.). The cumulative probability for cure or improvement at 1 year was 0.30 for PTD and 0.88 for surgery (P &lt; 0.001).
3. We conclude that PTD may be a satisfactory alternative to surgery in fibromuscular disease, but is inferior to surgery in atherosclerotic disease causing renal artery stenosis.
4. A randomized clinical trial is needed to define the role of PTD and surgery in renal artery stenosis.
Can Placebo Therapy Influence Arterial Blood Pressure?
Authors: Gould B. A. , Mann S. , Davies A. B. , Altman D. G. , Raftery E. B. 
Published: August 2015

1. With standard sphygmomanometric techniques used in conjunction with continuous intra-arterial monitoring the antihypertensive effect of placebo was examined in a group of patients participating in a controlled clinical trial.
2. Twelve of the 20 patients entered completed all stages of a randomized double-blind controlled trial of placebo and indoramin. Clinic blood pressure in patients receiving placebo showed reductions which were highly significant (P &lt; 0.001). Simultaneous intra-arterial monitoring showed no reduction of the blood pressure over the 24 h studied.
3. The clinic pressures showed minimal reduction of blood pressure in response to indoramin therapy whereas intra-arterial pressures showed a significant fall (P &lt; 0.01).
4. The response of the blood pressure to placebo appears to be an artifact of the indirect sphygmomanometric method and its use as a control in this study led to under-estimation of the efficacy of indoramin.