bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Ratio between Thickness of Media and Internal Radius in Cerebral, Mesenteric and Renal Arterial Vessels in Spontaneously Hypertensive Rats
Authors: Nordborg C. , Johansson B. B. 
Published: August 2015

1. Larger arterial vessels of 15-day-old spontaneously hypertensive (SH) rats showed significantly greater media/internal radius ratio than those of Wistar—Kyoto rats in the brain, kidney and mesentery.
2. Since larger cerebral and renal arteries of adult SH rats did not differ from controls the above results indicate the presence of a non-pressure-dependent vascular abnormality in young SH rats.
3. There were marked differences between the vascular beds of adult SH rats in the increase of media/radius ratio. Thus the changes were evident in all sizes of mesenteric arteries but only in the smallest cerebral arteries.
The Effect of High Animal Protein Intake on the Risk of Calcium Stone-Formation in the Urinary Tract
Authors: Robertson W. G. , Heyburn P. J. , Peacock M. , Hanes F. A. , Swaminathan R. 
Published: August 2015

1. Studies were carried out on six normal male subjects to determine the short-term effect of increasing the dietary consumption of animal protein on the urinary risk factors for stone-formation, namely, volume, pH, calcium, oxalate, uric acid and glycosaminoglycans.
2. An increase of 34 g/day of animal protein in the diet significantly increased urinary calcium (23%) and oxalate (24%). Total urinary nitrogen increased by an average of 368 mmol/day. The accompanying increase in dietary purine (11 mmol of purine nitrogen/day) caused a 48% increase in the excretion of uric acid.
3. The overall relative probability of forming stones, calculated from a combination of the risk factors, was markedly increased (250%) throughout the period of high animal protein ingestion.
Activation of Inactive Plasma Renin by Plasma and Tissue Kallikreins
Authors: Derkx F. H. M. , Tan-Tjiong H. L. , Veld A. J. Man In 'T , Schalekamp M. P. A. , Schalekamp M. A. D. H. 
Published: August 2015

1. Normal human plasma contains a pro-activator of inactive renin. The pro-activator is activated at physiological pH in plasma that has been pretreated with acid. This activation in vitro leads to the conversion of inactive renin into the active form with simultaneous generation of kallikrein activity.
2. The endogenous activator of inactive renin has the same pH profile and inhibitor spectrum as plasma kallikrein.
3. Inactive renin can also be activated by exposure of plasma to exogenous trypsin, and in normal plasma the quantities of inactive renin that are activated after acidification and with trypsin are identical. Prekallikrein (Fletcher factor)-deficient plasma, however, has much lower renin activity after acidification than with trypsin. Thus acid activation of inactive renin depends on plasma prekallikrein, whereas the action of trypsin is independent of prekallikrein.
4. Highly purified tissue (pancreatic) kallikrein, in a concentration of less than 2 × 10−8 mol/l, activates inactive renin that has been isolated from plasma by ion-exchange chromatography. In this respect it is at least 100 times more potent than trypsin.
5. It is therefore possible that plasma and/or tissue (renal) kallikreins are also involved in the activation of inactive renin in vivo.
Protein Synthesis and Composition of Cardiac and Vascular Tissue in Spontaneously Hypertensive Rats and the Effects of β-Adrenergic Antagonist Treatment
Authors: Boström S.-L. , Fryklund J. 
Published: August 2015

1. Propranolol and metoprolol were given in the diet of spontaneously hypertensive (SH) rats during the development of hypertension.
2. At the early established phase of hypertension, protein synthesis and protein composition of the left ventricle, aorta, mesenteric artery and vena cava were measured.
3. The left ventricle, aorta and mesenteric artery from the SH rats were hypertrophied compared with control Wistar—Kyoto rats, and protein composition was not dramatically changed. The increased protein content could only in a few cases be assigned to an increased protein synthesis at this age.
4. Both β-adrenergic antagonists prevented the hypertrophy of aorta and mesenteric artery but not in heart.
Mathematical Analysis of the Diagnostic Relevance of Clinical Findings
Authors: Llewelyn D. E. H. 
Published: August 2015

1. The process of diagnosis by elimination in terms of probabilities is analysed mathematically.
2. A piece of evidence which is only associated with a small number of differential diagnoses is of particular importance.
3. To deal with a differential diagnosis, a feature is required which occurs commonly in a postulated diagnosis but rarely in its rivals, irrespective of its frequency in those already discriminated against.
4. By using this analysis, inadequate evidence may be identified, new tests developed, and their effectiveness assessed in a logical and efficient way.
5. The approach is illustrated by considering the differential diagnosis of localized right lower quadrant abdominal pain.
Origin of Kallikrein in Rat and Human Exocrine Glands and Kidney
Authors: Ørstavik T. B. , Nustad K. , Brandtzaeg P. 
Published: August 2015

1. The cellular localization of kallikrein was investigated in rat and human exocrine glands and kidney by a direct immunofluorescence technique.
2. Kallikrein was found in the duct system of the rat and human major salivary glands.
3. Kallikrein was found in the distal tubular cells of the rat kidney. Attempts to localize kallikrein in the human kidney were unsuccessful.
4. In the rat and human pancreas, kallikrein was found as a pro-enzyme in the acinar cells.
Physical Activity and the Circadian Rhythm of Blood Pressure
Authors: Mann S. , Craig M. W. Millar , Melville D. I. , Balasubramanian V. , Raftery E. B. 
Published: August 2015

1. Ambulatory blood pressure monitoring was carried out in 10 subjects for a period of 48 h, the first or second 24 h part of which was selected randomly to be a period of complete bed rest.
2. Heart rate was significantly lower throughout the period of bed rest except for the period 04.00–08.00 hours, when there was little difference.
3. The circadian variation of blood pressure was reduced during the day of bed rest but this was mainly due to higher night-time pressures.
Relationship between the Basal Blood Alanine Concentration and the Removal of an Alanine Load in Various Clinical States in Man
Authors: Elia M. , Ilic Vera , Bacon Susan , Williamson D. H. , Smith R. 
Published: August 2015

1. Blood alanine was measured in six patients undergoing total hip replacement and in four normal subjects starved for 4 days. Hypoalaninaemia occurred in both groups and persisted in the surgical patients despite an adequate diet. The blood alanine was also low in four insulin-dependent diabetic patients and in four patients with muscular dystrophy; it was normal in four patients with cirrhotic liver disease.
2. The removal of an intravenous l-alanine load (12 g; 133 mmol) was significantly increased after surgery and in the diabetic patients, unaltered by starvation, and decreased in the cirrhotic patients.
3. Increases in blood glucose were observed when alanine infusion was performed 6 h after surgery and after 3 days' starvation. Increases in blood lactate and pyruvate always occurred after alanine infusion but were most marked 6 h after surgery.
4. These results show that the metabolic response to an alanine load and the ability of the body to remove it alter with change in physiological state, and that the hypoalaninaemia after surgery and in diabetes is related to an increased removal of intravenous alanine, whereas that during starvation is not.
Cooling Responses in Shivering and Non-Shivering Dogs during Induced Hypothermia
Authors: Auld C. D. , Light I. M. , Norman J. N. 
Published: August 2015

1. Hypothermia to a temperature of 30°C was induced in both shivering and non-shivering groups of dogs.
2. There was a sustained increase in oxygen consumption in the dogs allowed to shiver and this was up to 300% greater than the oxygen consumption in the relaxed dogs.
3. The increased tissue requirement for oxygen was met both by increased cardiac output and increased oxygen extraction from haemoglobin.
4. Oxygen utilization remained adequate in hypothermia, as shown by the absence of hypoxic acidosis.
5. Heart rate fell during cooling and stroke volume increased to meet the increased oxygen demands associated with shivering during the induction of hypothermia.
Resistive Load Detection during Passive Ventilation
Authors: Killian K. J. , Mahutte C. K. , Campbell E. J. M. 
Published: August 2015

1. By using standard psychophysical techniques resistive load detection was estimated in five normal subjects during spontaneous breathing and during passive ventilation in a Drinker respirator.
2. During assisted ventilation a gross deterioration in resistive load detection occurred.
3. The findings imply that active respiratory muscle contraction plays an essential role in the detection of added resistive loads.
Effects of Prostaglandins on Renin Substrate Production by the Liver
Authors: Murakami Eiki , Hiwada Kunio , Kokubu Tatsuo 
Published: August 2015

1. The effects of prostaglandin (PG) E1, PGE2 and PGF2α on plasma renin substrate concentration in rats and renin substrate production by perfused rat liver were investigated.
2. After bilateral nephrectomy, both plasma renin substrate concentration and renin substrate production were remarkably elevated.
3. The increase in plasma renin substrate level and production of renin substrate by the liver after nephrectomy was markedly suppressed by the treatment with PGE1 or PGE2.
4. In contrast PGF2α had no suppressive effect on renin substrate synthesis.
5. These findings suggest that PGE1 and PGE2 might be inhibitory factors in the regulation of renin substrate synthesis.
Presence of Postsynaptic α2-Adrenoreceptors of Predominantly Extrasynaptic Location in the Vascular Smooth Muscle of the Dog Hind Limb
Authors: Langer S. Z. , Massingham R. , Shepperson N. B. 
Published: August 2015

1. In the autoperfused hind limb of the dog prazosin (10μg/kg intravenously) markedly antagonized responses to lumbar sympathetic stimulation, whereas responses to injected nor-adrenaline were largely unaffected.
2. In β-adrenoreceptor- and ganglion-blocked animals, the hind limb pressor responses to phenylephrine were antagonized to a greater degree by prazosin than responses to injected noradrenaline.
3. Rauwolscine, a selective α2-adrenoreceptor-blocking agent, antagonized responses to the α2-adrenoreceptor agonist guanabenz, but not those to phenylephrine.
4. Hind limb pressor responses to noradrenaline were significantly inhibited by rauwolscine and further reduced by prazosin.
5. These results demonstrate that in this vascular bed α1- and α2-adrenoreceptors are located postsynaptically. Furthermore the results suggest that neuronally released noradrenaline acts mainly upon α1-adrenoreceptors, whereas exogenous noradrenaline acts upon α1- and α2-adrenoreceptors.
6. It is suggested that this selectivity of prazosin in blocking the vasoconstriction to neuronally-released noradrenaline may in part explain the effectiveness of this drug as an antihypertensive agent.
Metoprolol in Diabetes Mellitus: Effect on Glucose Homeostasis
Authors: Garrett B. N. , Raskin P. , Kaplan N. M. 
Published: August 2015

1. In eight hypertensive diabetic subjects receiving hydrochlorothiazide, glucose homeostasis as measured by the changes in plasma glucose, insulin and glucagon after an oral glucose load was not significantly affected by 8 weeks of therapy with metoprolol.
2. The combination of metoprolol plus hydrochlorothiazide significantly lowered blood pressure in all subjects.
3. Plasma renin activity was suppressed by therapy with metoprolol.
The Effect of Respiratory Muscle Fatigue on Respiratory Sensations
Authors: Gandevia S. C. , Killian K. J. , Campbell E. J. M. 
Published: August 2015

1. Eight subjects maintained maximal inspiratory pressure as long as possible. The subjects accurately judged the pressure developed, but considered that the sense of effort or motor command increased progressively during the contraction as fatigue developed.
2. A reference inspiratory load was overestimated after maximal inspiratory contractions.
3. These findings are consistent with the hypothesis that awareness of the motor command or effort contributes to the estimation of respiratory loads.
Dependence of Transcutaneous Oxygen Tension on Local Arteriovenous Pressure Gradient in Normal Subjects
Authors: Wyss C. R. , Matsen F. A. , King Racheal V. , Simmons C. W. , Burgess E. M. 
Published: August 2015

1. We studied the relationship between trans-cutaneous oxygen tension at the foot and local arteriovenous pressure difference in 15 normal men and women; arteriovenous pressure difference was varied by changing the height of the foot with respect to the heart and by applying external pressure to the foot.
2. Control transcutaneous oxygen tension was 67 ± 9 sd mmHg (8.9 ± 1.2 kPa) at a control arteriovenous pressure difference of 80 ± 6 sd mmHg (10.6 ± 0.8 kPa).
3. In every subject transcutaneous oxygen tension fell non-linearly with a decrease in arteriovenous pressure difference; transcutaneous oxygen tension was relatively insensitive to changes in arteriovenous pressure difference when arteriovenous pressure difference was high, but always fell sharply to zero at some positive arteriovenous pressure difference [range 13-34 mmHg (1.7-4.5 kPa)].
4. An analysis of the data indicated that transcutaneous oxygen tension varied with arteriovenous pressure difference approximately as the oxygen tension of cutaneous venous blood under the sensor varied (in the absence of changes in cutaneous vascular resistance and oxygen consumption).
5. This analysis was supported by studies in three subjects in whom the oxygen tension of superficial venous drainage from a warmed hand or foot was measured along with Transcutaneous oxygen tension while arteriovenous pressure difference was varied.
Regional Blood Flow in Borderline and Sustained Essential Hypertension
Authors: Temmar M. M. , Safar M. E. , Levenson J. A. , Totomoukouo J. M. , Simon A. Ch. 
Published: August 2015

1. Cardiac output, lower-limb blood flow, hepatic and renal blood flows were studied in 16 patients with borderline and 16 patients with sustained essential hypertension and compared with 16 age-matched control subjects.
2. In borderline hypertension cardiac output and lower-limb blood flow were significantly elevated, while hepatic and renal blood flows were within the normal range. Cardiac output and lower-limb blood flow were positively correlated.
3. In sustained hypertension cardiac output, lower-limb blood flow and hepatic blood flow were within the normal range. Renal blood flow was significantly reduced. Lower-limb blood flow was negatively correlated with mean arterial pressure.
4. If borderline hypertension is an early stage of fixed hypertension, the present study suggests that the changes in cardiac output observed in hypertension are mainly related to lower-limb (and muscle) blood flow.
Variations in Individual Organ Release of Noradrenaline Measured by An Improved Radioenzymatic Technique; Limitations of Peripheral Venous Measurements in the Assessment of Sympathetic Nervous Activity
Authors: Brown M. J. , Jenner D. A. , Allison D. J. , Dollery C. T. 
Published: August 2015

1. The validity of plasma noradrenaline as an index of sympathetic nervous activity was assessed by estimating variation in individual organ contribution to circulating concentrations.
2. Arteriovenous (A—V) differences in noradrenaline and adrenaline concentration were measured across several organs in nine patients with mild essential hypertension, in five with renal artery stenosis and 15 phaeochromocytoma patients.
3. In patients with phaeochromocytomas the percentage extraction of noradrenaline and adrenaline (estimated from the A—V differences) was similar across all organs, suggesting that adrenaline extraction could be used as a marker for noradrenaline extraction.
4. In the non-tumour patients the A—V difference for noradrenaline was less than that for adrenaline across most organs studied, reflecting the net result of noradrenaline release and extraction. The estimated contribution of various organs to the noradrenaline concentrations in their venous effluent was: heart. 21%; kidney 47%; legs 68%.
5. This pattern of A—V difference proved a positive diagnostic feature for non-tumour patients since it was not found even in the patients with small phaeochromocytomas, whose peripheral venous noradrenaline concentration alone did not distinguish them.
6. The venous-arterial difference across the adrenal glands of non-tumour patients was more than 10-fold greater for adrenaline than that for noradrenaline. Since the mean arterial concentration of noradrenaline was more than fivefold higher than that of adrenaline, the normal adrenal contribution to circulating noradrenaline is likely to be less than 2%.
7. In the patients with renal artery stenosis renal venous concentrations of noradrenaline (from the ischaemic kidney) were higher than arterial values, but mean arterial values were no higher than in the essential hypertensive patients.
8. Local variations in sympathetic activity may occur without altering the plasma noradrenaline concentration measured in peripheral plasma.
Relation of Arterial Pressure with Exchangeable and Total Body Sodium and with Plasma Exchangeable and Total Body Potassium in Essential Hypertension
Authors: Beretta-Piccoli C. , Davies D. L. , Boddy K. , Brown J. J. , Cumming A. M. M. , East W. B. , Fraser R. , Lever A. F. , Padfield P. , Robertson J. I. S. , Weidmann P. , Williams E. D. 
Published: August 2015

1. Arterial pressure, plasma electrolytes and exchangeable sodium were measured in 91 patients with essential hypertension and in 121 normal control subjects. Total body sodium, exchangeable potassium and total body potassium were also measured in some of the hypertensive patients.
2. Mean plasma sodium concentration was slightly but significantly lower in the hypertensive patients as a group, but mean values for other electrolyte measurements were close to normal or predicted normal.
3. Exchangeable sodium was not related to arterial pressure in normal subjects but in hypertensive patients exchangeable sodium correlated significantly with systolic and diastolic pressures. These correlations were significant with two methods of expressing exchangeable sodium, in the whole group of patients, in men and in older patients. Exchangeable sodium was not significantly related to arterial pressure in young patients.
4. Total body sodium also correlated significantly with systolic and diastolic pressures in hypertensive patients.
5. Exchangeable sodium was significantly related to age in hypertensive patients but not in normal subjects. Mean exchangeable sodium was significantly lower than normal in young patients.
6. Plasma potassium concentration was not related to arterial pressure in normal subjects but in essential hypertensive patients plasma potassium concentration, exchangeable potassium and total body potassium correlated negatively with systolic and diastolic pressures. These correlations were also significant in young, but not in old patients.
Adrenaline Neurons and PNMT Activity in the Brain and Spinal Cord of Genetically Hypertensive Rats and Rats with DOCA—salt Hypertension
Authors: Chalmers J. P. , Howe P. R. C. , Wallmann Y. , Tumuls I. 
Published: August 2015

1. We have studied the number of phenylethanolamine-N-methyltransferase (PNMT)-containing nerve cells in the medulla and the activity of PNMT in the medulla, spinal cord and hypothalamus of the rat.
2. At 4 weeks of age there was an increase in the number of PNMT cells counted in the medulla of the spontaneously hypertensive rat (SHR; 21%, P &lt; 0.01) and the stroke-prone spontaneously hypertensive rat (SHR-SP; 22%, P &lt; 0.01) compared with the Wistar-Kyoto (WKY) control rat.
3. At 4 months of age there were no significant differences in the number of medullary PNMT cells in two normotensive strains (WKY and Fisher rats), two genetically hypertensive strains (SHR and SHR-SP) and in DOCA-salt hypertensive rats.
4. In four week old rats the activity of PNMT was increased by about 50% in the spinal cord and medulla of the SHR and SHR-SP compared with the WKY rats, and immunotitration experiments suggest that this is due to an increased concentration of enzyme.
5. At 4 months of age there were no increases in PNMT activity of either genetically hypertensive rats or DOCA-salt hypertensive rats.
Effect of Converting Enzyme Inhibition on the Systemic and Renal Responses to Acute Isotonic Volume Expansion in Normal Man
Authors: Mimran A. , Ribstein J. 
Published: August 2015

1. Systemic, humoral and renal responses to isotonic volume expansion (1800 ml in 3 h) were assessed in normal subjects before and during captopril administration.
2. Captopril, which otherwise induced a decrease in pre-saline mean arterial pressure (MAP), unmasked the volume-dependence of MAP, which increased linearly during volume expansion (+ 18.7 ± 3.8% at the end of volume expansion).
3. Captopril prevented the fall in plasma aldosterone produced by volume expansion but did not modify the natriuretic response to saline.
4. These results suggest that intrarenal rather than circulating angiotensin II may be one of the determinants of the natriuretic response to volume expansion in normal man.
Kallikrein and Renin: Molecular Biology and Biosynthesis
Authors: Morris B. J. , Catanzaro D. F. , Richards R. I. , Mason A. , Shine J. 
Published: August 2015

1. A cDNA clone library was constructed from male mouse submandibular gland poly(A)+RNA.
2. A 500 base-pair sequence consisting of a 3′ untranslated region plus a 447 base-pair region coding for an amino acid sequnce having 57% homology with the C-terminal 149 amino acids in the 230 amino acid chain of porcine pancreatic kallikrein was identified.
3. The sequence was strongly but not completely homologous with known mouse submandibular gland serine proteinase sequences and represents the first report of a DNA base sequence for a serine proteinase. It may be part of the gene coding for kallikrein.
4. The biosynthetic pathway for renin was established by continuous-labelling, pulse-chase and cell-free translation studies of submandibular gland tissue from normal and testosterone-induced mice.
5. Renin was synthesized as a mol. wt. 46 000 preprorenin which is likely to be hydrolysed before completion of the nascent chain. A prorenin of mol. wt. 44 500, pI 6.4 was identified and shown to be rapidly converted into a mol. wt. 40 000, pI 6.2 renin, which was then converted more slowly into forms of mol. wt. 35 500, pI 5.6 and mol. wt. 34 000, pI 5.4.
BM 12.434, a Novel Compound with Vasodilating and β-Adrenoceptor-Blocking Activities
Authors: Von Möllendorff E. , Huschka C. , Schröter E. , Abshagen U. 
Published: August 2015

1. BM 12.434 was compared with a known β-adrenoceptor-blocking agent, metipranolol, and a combination of metipranolol and isosorbide-5-mononitrate in healthy volunteers. BM 12.434 and metipranolol were given in equi-effective β-adrenoceptor-blocking doses (reduction of exercise-increased pulse-pressure product).
2. Responses of the cardiovascular system were determined by non-invasive methods.
3. BM 12.434 increased the peripheral resistance less than metipranolol.
4. After BM 12.434, in contrast to metipranolol, both arterial flow and the venous capacity showed significant increase.
5. The combination of isosorbide-5-mononitrate and metipranolol differed from metipranolol alone mainly by the effect on venous capacity, which showed a slight increase.
6. BM 12.434 is a β-adrenoceptor-blocking agent whose additional actions on the veins and arteries are potentially useful for the treatment of both coronary heart disease and of arterial hypertension.