bluuebunny/crossref_metadata_2025_split huggingface dataset:
Platelet fatty acid composition in relation to fatty acid composition in plasma and to serum lipoprotein lipids in healthy subjects with special reference to the linoleic acid pathway
Authors: Boberg M. , Croon L. B. , Gustafsson I.-B. , Vessby B. 
Published: August 2015

1. The fatty acid composition in platelet phospholipids and in the plasma lipid esters as well as the serum lipoprotein lipid concentrations were determined in 67 healthy male subjects in order to establish the relationships between blood lipids and platelets.
2. A positive correlation was found between the concentrations of the triglyceride rich serum lipoprotein lipids and the relative percentage of saturated and monounsaturated fatty acids in plasma. The correlations were also positive between the serum high density lipoprotein-cholesterol concentration and the relative content of linoleic acid in the plasma cholesterol esters and phospholipids.
3. Negative correlations were found between the relative percentage of saturated and monounsaturated fatty acids in the plasma lipid esters versus linoleic acid in plasma and in the platelets. On the other hand there were positive correlations between linoleic acid in the plasma lipid esters and in the platelet phospholipids. These results indicate a direct dietary influence on the platelet phospholipid fatty acid composition.
4. The correlations between the fatty acids of the n −6 series within plasma and platelets as well as between plasma and platelets indicate that a high linoleic acid content is not associated with an increased arachidonic acid concentration. The results also indicate that the limiting metabolic step in the conversion of linoleic acid into arachidonic acid may be located at different levels in plasma and in the platelets.
Lack of effect of indomethacin on systemic and splanchnic haemodynamics in portal hypertensive rats
Authors: Blanchart A. , Hernando N. , Fernández-Muñoz D. , Hernando L. , López-Novoa J. M. 
Published: August 2015

1. Portal hypertension was produced experimentally in rats by partial constriction of the portal vein.
2. Twelve rats were injected daily with indomethacin, 4 mg/kg body weight, and 12 with the vehicle (80% ethanol, 0.5 ml/day).
3. There were no differences in portal-systemic shunts nor systemic or splanchnic haemodynamics between indomethacin-treated and untreated rats.
4. These results suggest that cyclo-oxygenase products do not play a significative role in haemodynamic alterations shown by portal-ligated rats.
Exercise blood pressure and baroreflex function in borderline hypertensive and normotensive young men
Authors: Welsh Kevin , Ward Ann , Hanson Peter 
Published: August 2015

1. Resting carotid baroreflex sensitivity and blood pressure responses to standardized conditions of rest and exercise were measured in 17 borderline hypertensive males and 12 normotensive males.
2. The borderline hypertensive group had significantly higher systolic and diastolic blood pressures during orthostatic rest and isometric handgrip exercise and higher systolic blood pressure during supine rest and submaximum and maximum treadmill exercise.
3. The borderline hypertensive group had an attenuation of baroreflex sensitivity compared with the normotensive group. Resting baroreflex sensitivity was significantly correlated with absolute systolic blood pressure during supine rest, orthostatic rest, isometric handgrip exercise and submaximum treadmill exercise.
4. The results indicate that blood pressure is regulated at a significantly higher level during rest and exercise in borderline hypertension and is associated with reduced baroreflex sensitivity measured at supine rest.
Direct measurement of vascular α1-adrenoceptors
Authors: Hoffman Brian B. , Tsujimoto Gozoh 
Published: August 2015

1. α-Adrenoceptors play an important role in regulating vascular tone. [125I]BE2254, a high affinity antagonist, has been utilized to label α1-receptors in membrane preparations from rabbit aorta. [125I]BE2254 specifically labels a single class of binding sites with the characteristics of α1-receptors.
2. Catecholamines compete for [125I]BE2254 binding stereospecifically and with the characteristic α-adrenergic potency series (−)-adrenaline ≥ (−)-noradrenaline ≪ (−)-isoprenaline.
3. The α1-adrenoceptor selective antagonist prazosin is much more potent than yohimbine in competing for the [125I]BE2254 binding sites, which suggests that the α-adrenoceptor identified is predominantly of the α1 subtype.
4. The extension of radioligand binding techniques to individual rabbit aortas should simplify the study of vascular α-adrenoceptor regulation.
α-Adrenoceptor regulation in vivo and in vitro in the rabbit
Authors: Hamilton C. A. , Jones C. R. , Reid J. L. 
Published: August 2015

1. The relationship between α-adrenoceptor number and response has been studied in rabbits under a range of physiological and pathological conditions.
2. The effects of irreversible α-adrenoceptor blockade, maturation, ageing, oestrogen treatment, adrenaline infusion, perinephritis hypertension and sinoaortic denervation on α-adrenoceptor number and response were examined.
3. α-Adrenoceptor number was measured by radioligand binding. [3H]Prazosin and [3H]clonidine were used as ligands to measure α1- and α2-adrenoceptor number in spleen and [3H]yohimbine to measure α2-adrenoceptor number on platelets. Responses in vivo were studied by examining the pressor responses to a range of α-adrenoceptor agonists. The functional response of platelets was examined in vitro by using the aggregatory response to adrenaline.
4. Reductions in α2-adrenoceptor ligand binding were consistently accompanied by equivalent reductions in α2-adrenoceptor-mediated responses. In contrast large reductions in [3H]prazosin binding were observed with little or no change in α1-adrenoceptor-mediated responses.
5. These results would be consistent with a large receptor reserve for α1-adrenoceptors but few if any spare α2-adrenoceptors in the vasculature or on platelets.
6. Increased responses to both α1- and α2-adrenoceptor agonists were observed in animals with sinoaortic denervation and to α1-adrenoceptor agonists in rabbits with perinephritis hypertension. These increases in response were not accompanied by increases in radioligand binding and may be related to alterations in the coupling of receptor activation to end-organ response.
Vascular α-adrenoceptors in man: interactions with adrenaline and noradrenaline
Authors: Brummelen Peter Van , Jie Kenneth , Vermey Pieter , Timmermans Pieter B. M. W. M. , Zwieten Pieter A. Van 
Published: August 2015

1. Adrenaline and noradrenaline were infused in cumulative doses into the brachial artery of six healthy volunteers and changes in forearm blood flow (FBF) were measured by plethysmography. The catecholamines were infused together with saline, yohimbine and doxazosin, in that order. All infusions were given in the presence of intraarterial propranolol - to prevent β-adrenoceptor-mediated effects.
2. Adrenaline and noradrenaline reduced FBF significantly. This decrease in FBF was significantly attenuated by doxazosin as well as by yohimbine. No differences were found between adrenaline and noradrenaline.
3. It is concluded that postjunctional α1- and α2-adrenoceptors are involved in the vasoconstriction caused by exogenous adrenaline and noradrenaline in man. The relevance of circulating adrenaline for the α2-adrenpceptor-mediated contribution to basal vascular tone remains to be established.
Bile Lipid Secretion in Obese and Non-Obese Individuals with and without Gallstones
Authors: Reuben A. , Maton P. N. , Murphy G. M. , Dowling R. H. 
Published: August 2015

1. Biliary lipid secretion rates were measured in non-obese and obese individuals with and without cholesterol gallstones, using a steady-state, amino acid duodenal perfusion method. In addition, biliary lipid secretion rates were measured in five obese gallstone patients receiving high-dose chenodeoxycholic acid therapy (16-22 mg day−1 kg−1).
2. Bile acid secretion rates in the non-obese patients with cholesterol gallstones (563+sem 70 μmol/h, n = 6) were significantly lower than in the non-obese controls (1078 + 210 μmol/h, n = 10, P &lt; 0.05), whereas cholesterol secretion rates were similar in the non-obese individuals with and without gallstones (51+7 and 42+4 μmol/h respectively).
3. In the obese, both with and without gallstones, the major abnormality was hypersecretion of cholesterol (107+7 μmol/h, n = 7, and 81 + 15 μmol/h, n = 7, respectively). Both these values were significantly greater than those in the non-obese controls (P &lt; 0.01-0.02).
4. Biliary cholesterol secretion rates correlated significantly with bile acid secretion rates but, for every mole of bile acid secreted, the obese secreted more cholesterol than the non-obese.
5. Chenodeoxycholic acid treatment lowered biliary cholesterol saturation in obese gallstone patients by reducing biliary cholesterol secretion.
6. These results suggest that there are two major types of defect in biliary lipid secretion in gallstone patients: reduced biliary bile acid secretion in non-obese gallstone patients and excessive biliary cholesterol secretion in the obese.
Evaluation of a Non-Invasive Method for the Measurement of Metabolic rate in Humans
Authors: Weissman Charles , Damask Michael C. , Askanazi Jeffrey , Rosenbaum Stanley H. , Kinney John M. 
Published: August 2015

1. Measurements of oxygen consumption (VO2) and carbon dioxide production (VCO2) can be used to calculate energy expenditure. Such data are useful in the nutritional management of a variety of pathological conditions.
2. This study is an evaluation in vitro and in vivo of the mating of a canopy and a Beckman metabolic measurement cart 1 (MMC). The canopy allows for the collection of expired gases without facial attachments.
3. Studies in vitro demonstrated the necessity of calibrating the CO2 analyser at the concentrations used in such a system (0.50-0.80% CO2). Measurements of Vo2 were within +12% to −8% of predicted values, and when calibrated at 0.50% and 0.75% CO2, measurements of Vco2 were within +2% and −7% of predicted values.
4. The studies in vivo revealed that VO2 and Vco2 were within ± 11% of the values obtained by using a canopy-spirometer-computer system.
5. The MMC plus canopy may provide an alternative method for the clinical measurement of Vo2 and Vco2, especially in subjects unable to tolerate a tight-fitting mask for prolonged periods.
Biochemical and Morphometric Properties of Mitochondrial Populations in Human Muscle Fibres
Authors: Elander Anna , Sjöström Michael , Lundgren Fredrik , Scherstén Tore , Bylund-Fellenius Ann-Christin 
Published: August 2015

1. Two mitochondrial subpopulations were evaluated with biochemical and morphological techniques in human gastrocnemius muscle of 10 patients with peripheral arterial insufficiency and 12 control individuals.
2. The subsarcolemmal mitochondria were released by gentle homogenization, with a recovery of 32-37%, and the intermyofibrillar by enzymic digestion and further mechanical disintegration, recovery 18-21%. The subsarcolemmal mitochondria were morphologically defined as those located within 2 μm from the sarcolemma membrane and the intermyofibrillar mitochondria as those located in the rest of the fibre.
3. In the controls the intermyofibrillar mitochondria had a lower respiratory ratio than the subsarcolemmal, owing to a higher state II respiration. The subsarcolemmal space, which contained 25% of the mitochondria, had a mitochondrial volume density two- to three-fold that of the intermyofibrillar space in the controls.
4. The patients, who had a 48-64% higher oxidative enzyme capacity in their muscle tissue, had higher respiratory rate and respiratory control index with similar ADP/O ratio in the subsarcolemmal fraction in comparison with the controls. The citrate synthase activity was higher in both mitochondrial fractions of the patients. The volume densities of mitochondria, total as well as for both subpopulations, were also higher in the patients, which was further reflected in higher yields of mitochondrial protein.
5. The results demonstrate that both sub-populations of muscle mitochondria are able to adapt quantitatively and/or qualitatively. Furthermore, they show that the increased oxidative enzyme capacity of the patients is associated with an increased quantity of both mitochondrial populations and a qualitative improvement of the respiratory activity of the subsarcolemmal mitochondria.
Maximal short term Exercise Capacity in Healthy Subjects Aged 15-70 Years
Authors: Makrides Lydia , Heigenhauser George J. F. , Mccartney Neil , Jones Norman L. 
Published: August 2015

1. Fifty males and 50 females, 15-71 years of age, exercised maximally for 30 s on an isokinetic ergometer at a pedalling frequency of 60 rev./min. Results were compared with maximal oxygen uptake (VO2 max.) obtained in a progressive incremental exercise test.
2. Total work in 30 s was higher in males than females, declined linearly by about 6% per decade of age (r = −0.65), and was related closely to height (r = 0.75) and to lean thigh volume estimated anthropometrically (r = 0.84). A close association with vital capacity (r = 0.86) was also found that accounted statistically for the combined effects of age and height.
3. The percentage decline in power during 30 s (fatigue index) was lower in subjects reporting greater leisure activity.
4. A close relationship was found between total work in 30 s and Vo2 max. (r = 0.86), with vital capacity and leisure activity exerting additional influences on Vo2 max. (P &lt; 0.001; multiple r = 0.93).
5. The well-established reduction with age in Vo2 max. is associated with an apparent parallel reduction in the power output capacity of large muscle groups recruited in heavy dynamic leg exercise.
Effects of Synthetic Atrial Natriuretic Peptides on Sodium-Potassium Transport in Human Erythrocytes
Authors: Sagnella G. A. , Nolan D. A. , Shore A. C. , MacGregor G. A. 
Published: August 2015

1. The effects of synthetic human and rat atrial peptides on sodium and potassium ion transport has been investigated in intact human erythrocytes.
2. The effects of these peptides have been tested on the active, sodium pump-dependent (ouabain-sensitive) and on the sodium-potassium cotransport system (bumetanide-sensitive) with 86Rb used as a tracer.
3. Human (α-ANP, 28 amino acids) or rat (atriopeptin III) atrial peptides, over a wide range of concentrations, did not influence the uptake of 86Rb in either the ouabain-sensitive or the bumetanide-sensitive transport system.
4. These results suggest that the natriuretic effect of the atrial peptides is not mediated through inhibition of the sodium pump or the loop-diuretic-sensitive Na-K cotransport.
α-Adrenoceptor Changes after Oestrogen Treatment in Platelets and other Tissues in Female Rabbits
Authors: Mishra N. , Hamilton C. A. , Jones C. R. , Leslie C. , Reid J. L. 
Published: August 2015

1. α2-Adrenoceptors on blood platelets have been widely used as a model for α-adrenoceptors in less accessible tissues.
2. The effect of oestrogen (200 μg/day intramuscularly) on α2-adrenoceptor number and function was studied in immature female rabbits. α2-Adrenoceptor number was measured in whole platelets, and membrane preparations of forebrain, hindbrain, spleen and kidney by radioligand binding. α2-Adrenoceptor function was examined by measuring platelet aggregation in vitro and circulatory responses to selective α2-adrenoceptor agonists in vivo.
3. Oestrogen treatment resulted in a significant decrease in platelet α2-adrenoceptor number and function. However, no changes were observed either in receptor number in other tissues or in responses to α2-agonists in vivo.
4. The results suggest that oestrogen modulation of rabbit platelet α2-adrenoreceptor number and function may be different from that of brain, kidney and spleen. Caution should be exercised in extrapolating results from platelets to α-adrenoceptors at other sites.
Increased albumin and normal dextran clearances in protein-overload proteinuria in the rat
Authors: Bliss David J. , Brewer Douglas B. 
Published: August 2015

1. Female Wistar rats were made heavily proteinuric by daily intraperitoneal injections of bovine serum albumin over 5 days.
2. The size and charge permeability characteristics of the glomerular filter in this condition were determined by studying the renal handling of poly-dispersed uncharged dextran over the range of molecular radii 2–6 nm (albumin 3.6 nm), and of endogenous rat serum albumin over the same clearance period.
3. In proteinuric rats the clearance of rat serum albumin was significantly increased with a resultant reduction in the circulating levels of rat serum albumin. The clearance of uncharged dextran was not significantly different in proteinuric rats compared with control animals.
4. There does not appear to be any size selective defect of the glomerular filtration barrier in this condition. This suggests that the observed increase in the clearance of the negatively charged endogenous albumin may be due to a reduction in the glomerular charge barrier.
Ventilatory saving by external chest wall compression or oral high-frequency oscillation in normal subjects and those with chronic airflow obstruction
Authors: George R. J. D. , Winter R. J. D. , Flockton S. J. , Geddes D. M. 
Published: August 2015

1. Oscillation of the air within the lungs at high frequency is associated with an increased clearance of CO2. Because of the high frequency and low volume of these oscillations, spontaneous breathing is unhindered and the technique has potential value as a supplement to ventilation.
2. High-frequency oscillations were superimposed upon tidal breathing by using a loudspeaker attached to a mouthpiece (oral high-frequency oscillation, OHFO) or by external chest wall compression (ECWC). We set out (a) to compare the changes in ventilation and breathlessness by using OHFO and ECWC in normal subjects with those in patients with chronic airflow obstruction (CAO), and (b) to relate the pattern of saving to the resonant frequencies of the respiratory system as a whole (fOT, 5–10 Hz in normal subjects, 16–26 Hz in CAO) and those of the ribcage(foc,70 Hz).
3. OHFO reduced minute ventilation (VE) by up to 46% in normal subjects (P &lt; 0.01) and 29% in CAO (P &lt; 0.01) without any rise in CO2. ECWC reduced VE by 27% in normal subjects (P &lt; 0.01) and 16% in CAO (P &lt; 0.01) without a rise in CO2.
4. High-frequency oscillation by either method relieved breathlessness in those with CAO and was comfortable and well tolerated.
5. In normal subjects for was discrete and varied little with respiration. Maximum savings occurred around for (5–10 Hz).
6. In CAO, there was no obvious single resonant frequency and flow and pressure signals were intermittently in phase over a band of about 10 Hz. Thus the reductions in minute ventilation were only loosely related to for (13–26 Hz). Neither group reduced VE at foc (65–75 Hz).
7. OHFO has considerable potential in the management of patients with CAO, where it may be of value as an assistance to breathing and in the relief of breathlessness. ECWC, although effective in principle, is impractical by our methods and awaits the development of an acceptable delivery system.
Changes in plasma free 3,4-dihydroxyphenylethylene glycol and noradrenaline levels after acute alcohol administration
Authors: Howes L. G. , Reid J. L. 
Published: August 2015

1. The effects of alcohol (0.9 g/kg) compared with placebo (400 ml of orange juice) on plasma noradrenaline and 3,4-dihydroxyphenylethylene glycol levels, and on erect and supine blood pressures and heart rates, were studied in eight normal male volunteers.
2. Alcohol caused a rise in noradrenaline levels that commenced approximately 30 min after drinking and lasted about 4h. In contrast, 3,4-dihydroxyphenylethylene glycol levels fell immediately after alcohol administration and remained low for at least 6h. Acute alcohol administration alters noradrenaline catabolism, and may have a dual effect of increasing noradrenaline release and decreasing noradrenaline clearance.
3. Alcohol caused a transient rise in erect and supine blood pressures that preceded the rise in plasma noradrenaline. Thereafter erect blood pressures fell compared with control. This fall was associated with a progressive rise in both supine and erect rates, and reached a maximum several hours after the maximum levels of blood alcohol.
4. The major effect of acute alcohol administration is to lower blood pressure and induce a reflex tachycardia. Changes in noradrenaline and 3,4-dihydroxyphenylethylene glycol levels did not readily explain changes in blood pressure or heart rate, suggesting that alcohol induced changes in noradrenaline metabolism occur largely independent of changes in blood pressure and heart rate.
Twenty-four hour hormonal and metabolic profiles in uraemic patients before and during treatment with continuous ambulatory peritoneal dialysis
Authors: Heaton A. , Johnston D. G. , Haigh J. W. , Ward M. K. , Alberti K. G. M. M. , Kerr D. N. S. 
Published: August 2015

1. Circulating intermediary metabolite and hormone concentrations were measured at intervals over 24 h in five uraemic patients before starting dialysis and after 3 months' treatment with continuous ambulatory peritoneal dialysis (CAPD) and in 13 non-uraemic normal controls.
2. Fasting and postprandial glucose concentrations were significantly raised in uraemic patients undialysed and on CAPD but 24 h mean (±sem) levels fell from 6.63 ± 0.40 to 6.00 ± 0.26 mmol/l (P &lt; 0.02) after 3 months' dialysis despite peritoneal glucose absorption. Insulin levels were raised in uraemic patients but were unchanged by CAPD.
3. Uraemia was associated with raised levels of the gluconeogenic precursors lactate and alanine and a further rise in fasting and 24 h mean alanine concentrations occurred with CAPD. Fasting total ketone body concentrations were raised in undialysed uraemic patients but concentrations were suppressed throughout the 24 h in CAPD subjects.
4. Fasting triglyceride concentrations were increased in uraemic subjects and mean 24 h levels rose by 30% from 1.55 ± 0.42 mmol/l before dialysis to 2.02 ± 0.59 mmol/l during CAPD. Non-esterified fatty acid concentrations were low in uraemic patients and remained low during CAPD.
5. Undialysed and dialysed uraemic patients displayed raised plasma glucagon concentrations throughout the 24 h, suppression of the normal nocturnal secretion of growth hormone and raised mean cortisol levels, which were 23% (CAPD) to 57% (undialysed) higher than in normal controls.
6. The endocrine and metabolic abnormalities of uraemia are not fully corrected by CAPD. Many of the additional changes observed during CAPD reflect an adaptation to the constant absorption of peritoneal glucose.