bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of frusemide and captopril on the relationship between biologically and immunologically active renin in human plasma
Authors: Higaki Jitsuo , Ogihara Toshio , Kumahara Yuichi 
Published: August 2015

1. The plasma renin concentration (PRC) and active renin concentration determined by radioimmunometric assay (ARC) were measured before and after administration of frusemide or captopril to normal volunteers.
2. Injection of 40 mg of frusemide followed by 1 h in the upright position significantly increased both PRC (P &lt; 0.001) and ARC (P &lt; 0.001). Oral administration of 50 mg of captopril also increased PRC (P &lt; 0.05) and ARC (P &lt; 0.05).
3. ARC and PRC were linearly correlated in the basal supine position [y = 0.635 x − 0.048 (y = PRC, x = ARC), r = 0.958, P &lt; 0.001], after frusemide injection and standing (y = 0.800x + 0.359, r = 0.793,P &lt; 0.02) and after captopril administration in the supine position (y = 0.938x − 0.555, r = 0.998,P &lt; 0.001).
4. A cross-calibration study in which pure human renin was added to pooled plasma and PRC and ARC were measured showed linearity between the values obtained by the two methods.
5. The regression line for values of PRC and ARC in the supine position after captopril administration had a significantly greater slope (P &lt; 0.001) and that for values after frusemide injection and standing was significantly elevated (P &lt; 0.001) compared with the regression line for basal values in the supine position.
6. These results show that the biological activity of renin may be increased by various acute stimulations of renin to inappropriately high levels compared with the immunological activity. This implies that the mode of processing of human plasma renin may be altered by acute stimulation of renin. Furthermore, current methods for assay of plasma active renin may give erroneous values in various pathophysiological conditions.
Urinary albumin excretion and blood pressure in the general population
Authors: Gosling Peter , Beevers D. G. 
Published: August 2015

1. Twenty-four hour urinary albumin excretion rate was measured by a sensitive radioimmunoassay in 99 male and 100 female randomly selected factory workers, aged between 20 and 60 years.
2 The median (range) albumin excretion rates for men and women of 4.67 (1.0–25.8) and 5.25 (0.2–33.0) mg/24 h, respectively, were not significantly different.
3. No correlation was established between diastolic, systolic or mean arterial blood pressure and albumin excretion rate for the whole group.
4. Twenty-eight subjects with systolic and/or diastolic blood pressures ≥ 140/90 mmHg (18.7/12.0 kPa) showed a positive correlation between mean arterial blood pressure and albumin excretion rate (r = 0.412,P &lt; 0.01).
5. There was no significant relationship between number of cigarettes smoked, age or alcohol intake and albumin excretion rate.
6. The data suggest that in the general population albumin excretion rate is variable and not dependent on blood pressure, but at blood pressures &gt; 140/90 mmHg (18.7/12.0 kPa) albumin excretion rate may become pressure dependent, although high albumin excretion rates were sometimes found in subjects with blood pressures &lt; 140/90 mmHg (18.7/12.0 kPa).
Plasma levels of the lyso-derivative of platelet-activating factor are related to age
Authors: Taylor Roger R. , Sturm Marian , Kendrew Philip J. , Vandongen Robert , Beilin Lawrence J. 
Published: August 2015

1. The effect of age on the plasma level of the lyso-derivative of platelet-activating factor (lyso-PAF) was studied in 72 normal subjects, (32 females, 40 males) aged 12–64 years. Lyso-PAF was acetylated in vitro to PAF which was measured by bioassay using 5-[14C]hydroxytryptamine-labelled rabbit platelets.
2. Under 40 years there were similar direct relations between plasma lyso-PAF and age in both sexes (linear regression; males, P &lt; 0.001; females, P &lt; 0.002), the level approximately doubling from the adolescent level around 100 ng/ml. However, in the later years the levels fell, the fall seeming to commence earlier in females, so that between 40 and 65 years the level was greater in males [169 ± 47(sd) vs 120 ± 30 ng/ml; P &lt; 0.01].
3. The increase in plasma lyso-PAF up to middle-age may be related to the reported increase in prostanoid production with age, since these platelet and vasoactive compounds can have a common origin in membrane phospholipid. This would be consistent with increasing phospholipase A2 activity and decreasing stability of cell membranes with age, but the later fall in lyso-PAF is then unexplained; the lesser values in females than males in the more advanced years could be related to females' generally lesser vascular disease. However, knowledge of the biological roles and metabolism of PAF is still very limited and the real significance of the findings remains to be determined.
Anaemia and reduced exercise capacity in patients on chronic haemodialysis
Authors: Mayer G. , Thum J. , Graf H. 
Published: August 2015

1. In order to evaluate the influence of varying degrees of anaemia on exercise capacity and haemodynamic parameters, 13 patients on chronic intermittent haemodialysis with haemoglobin levels between 5.1 and 12.2 g/100 ml were subjected to an exhaustive exercise test. Measurements during bicycle ergometry consisted of O2 uptake at the anaerobic threshold and of maximum O2 uptake. Resting haemodynamic parameters such as cardiac index, heart rate, stroke volume index and blood pressure were assessed non-invasively in the 13 patients undergoing exercise and in an additional three patients.
2. O2 uptake at the anaerobic threshold as well as maximum peripheral O2 uptake were severely impaired and were positively correlated with haemoglobin concentration. The strongest correlation was found between the impairment of O2 uptake at maximum workload, as assessed by maximum O2 uptake/predicted maximum O2 uptake, and haemoglobin concentration. Haemodynamic alterations in the resting state consisted of a cardiac index in the upper normal range and did not correlate with the haemoglobin concentration.
3. We conclude from our study that exercise capacity in patients on chronic intermittent haemodialysis is severely impaired and that the impairment of aerobic and anaerobic capacity is significantly correlated with the severity of renal anaemia.
Metabolic characteristics of human adipose tissue in vivo
Authors: Frayn K. N. , Coppack S. W. , Humphreys S. M. , Whyte P. L. 
Published: August 2015

1. A method was developed for sampling the venous drainage from the subcutaneous adipose tissue of the anterior abdominal wall. This is a large depot in many subjects, and seems well suited to such studies as it is completely separated from the venous drainage of the underlying muscle by the aponeurosis of the external oblique muscle.
2. Eight normal subjects were studied after an overnight fast, and for 120 min after ingestion of 75 g of glucose. Concentrations of substrates in the abdominal wall drainage were compared with those in arterialized blood and in forearm muscle drainage.
3. Non-esterified fatty acid and glycerol concentrations in the abdominal wall drainage were high (three to four times the arterial level) after overnight fast. After glucose ingestion, arterial and abdominal venous levels fell and the arteriovenous differences narrowed. The forearm showed uptake of non-esterified fatty acids when fasting but not after glucose ingestion, with no significant arteriovenous difference for glycerol at any time.
4. The abdominal wall tissues showed a small arteriovenous difference for glucose uptake during fasting, which increased after glucose ingestion. Although lactate was produced throughout, its molar ratio to glucose uptake was less than that reported for other superficial sites, suggesting only a minor contribution of skin metabolism. Forearm muscle showed a larger and more prolonged increase in arteriovenous difference for glucose uptake after the glucose load, but no consistent release or uptake of lactate.
5. We conclude that the tissue studied by this technique is predominantly adipose. This technique may have wide application in studies of the metabolic basis for body weight regulation in man.
Platelet efflux of noradrenaline in patients with type 1 diabetes mellitus
Authors: Smith C. C. T. , Wilson A. P. , Prichard B. N. C. , Betteridge D. J. 
Published: August 2015

1. Endogenous noradrenaline release from washed platelets incubated under resting conditions and in the presence of thrombin was examined in 14 normal subjects and 10 subjects with type 1 (insulin-dependent) diabetes.
2. Irreversible aggregation of platelets from both normal and diabetic subjects was induced by thrombin (0.3 unit/ml). Platelets from diabetic subjects were more sensitive than platelets from normal subjects, extents of aggregation being 89% and 76%, respectively (P &lt; 0.002).
3. Stimulation with thrombin (0.3 unit/ml) elicited marked platelet release of noradrenaline to the incubation medium in both normal and diabetic subjects. Supernatant noradrenaline concentrations obtained under thrombin-stimulated conditions did not significantly differ between normal and diabetic subjects. However, under resting conditions noradrenaline levels were significantly greater (+ 93%, P &lt; 0.02) for diabetic than normal subjects.
4. Measurement of platelet noradrenaline contents after thrombin stimulation revealed no difference between normal and diabetic subjects. Under resting conditions, however, platelet noradrenaline levels were significantly lower (−46%, P &lt; 0.02) for diabetic than normal subjects. Thus, in the diabetic subjects increased resting platelet efflux of noradrenaline is mirrored by a decreased platelet noradrenaline content.
5. A consequence of increases in resting catecholamine efflux may be enhanced platelet activity resulting in increased platelet aggregation.
Differential effect of high-dose naloxone on the plasma adrenaline response to the cold-pressor test
Authors: Bouloux P. M. G. , Newbould E. , Causon R. , Perry L. , Rees L. H. , Besser G. M. , Grossman A. 
Published: August 2015

1. Although the opiate antagonist naloxone has been shown to affect sympathoadrenomedullary function in some studies, this has not been a uniform finding in all investigations, using different doses of naloxone. We have therefore investigated the actions of saline placebo and increasing bolus doses of intravenous naloxone (25, 100 and 250 μg/kg) on the plasma noradrenaline, adrenaline, adrenocorticotrophin (ACTH) and cortisol responses to a cold-pressor test in six males and two females in a double-blind randomized study.
2. Basal levels of adrenaline did not differ on any of the study occasions: the cold-pressor stimulus produced a significant rise in mean plasma adrenaline to a peak of 0.16 nmol/l, with a peak incremental rise of 0.08 nmol/l. In the presence of the two higher doses of naloxone, the incremental rise in the mean adrenaline level was significantly enhanced, reaching 0.30 nmol/l at 100 μg of naloxone/kg and 0.29 nmol/l at 250 μg of naloxone/kg, with no significant enhancement observed at the lowest dose of naloxone. The rise in plasma noradrenaline, systolic and diastolic blood pressure and pulse rate during the cold-pressor test was not consistently altered by any dose of naloxone, but there was a significant trend for the degree of discomfort to increase with the dose of naloxone.
3. Neither plasma ACTH nor serum cortisol rose in response to the cold-pressor stimulus. Analysis of variance demonstrated a significant naloxone-treatment effect for both ACTH and cortisol, with the 100 μg/kg and 250 μg/kg doses of naloxone leading to a significant rise in mean plasma ACTH not seen at the lowest dose of 25 μg/kg.
4. In a separate study of the effect of naloxone on the clearance of plasma adrenaline, adrenaline was infused on two occasions into eight normal male subjects to a maximum dose of 5 μg/min for 15 min, and blood was sampled at regular intervals during and after termination of the infusion, preceded by 8 mg of naloxone or placebo. After termination of the adrenaline infusion, there was a rapid fall in plasma adrenaline (Λ = −1.9 ± 0.3 min), which was not altered by naloxone (Λ = −1.8 ± 0.3 min).
5. We conclude that the potentiation of the adrenaline response to a cold-pressor test by naloxone is mediated by increased secretion of adrenaline and not by a reduction in its clearance rate, and that this response is of low naloxone sensitivity.
Haemodynamic responses to vasopressin in anaesthetized young and adult Brattleboro rats
Authors: Obika L. F. O. , Laycock J. F. 
Published: August 2015

1. The cardiovascular effects of pressor doses of arginine vasopressin were examined in anaesthetized Brattleboro rats with hereditary diabetes insipidus (BDI) and normal rats of the parent Long Evans (LE) strain, either 37 or 85 days old.
2. Control mean arterial blood pressure and total peripheral resistance were similar in adult animals of the two strains but were significantly lower in the young BDI rats compared with the young LE rats.
3. The three doses of vasopressin produced greater pressor responses in the young, immature LE rats compared with the young BDI rats, whereas in the adult animals vasopressin had the greater pressor effect in the BDI rats compared with the LE rats of comparable age.
4. There was little effect of vasopressin on cardiac output after the initial decrease, particularly in the BDI rats whether immature or adult, despite more prolonged decreases in heart rate.
5. These studies indicate important age-related differences in the pressor response to vasopressin in anaesthetized rats, in addition to the clear differences in response between the animals with (LE) or without (BDI) the circulating endogenous peptide.
Coumarin and 7-Hydroxycoumarin Treatment of Canine Obstructive Lymphoedema
Authors: Knight Kenneth R. , Khazanchi Rakesh K. , Pederson W. Christopher , McCann John J. , Coe Serena A. , O'Brien Bernard McC. 
Published: August 2015

1. Canine obstructive lymphoedema was created in one hind leg of 30 dogs by irradiation of the groin and surgical removal of surviving lymph glands and lymphatics. The opposite leg served as a control. Once the oedema had stabilized, groups of 10 dogs were treated orally with 12.5 mg day−1 kg−1 for 8 months with either one of the benzopyrones coumarin (2H-1-benzopyran-2-one) and 7-hydroxycoumarin (7-hydroxy-2H-1-benzopyran-2-one), or placebo.
2. The two benzopyrones significantly (P &lt; 0.01) but gradually reduced the oedema by 20–30% over 8 months, as judged by circumferential measurements of the oedematous and control limbs. There was no change with the placebo.
3. In the oedematous fluids (lymph and interstitial fluid), benzopyrone treatment reduced the protein content and increased acid and neutral proteinase activity compared with the control limbs, while the levels of the proteinase inhibitor α2-macroglobulin remained unchanged. Furthermore, these active drugs reduced the excess water content, thickness and hydroxyproline content of skin biopsies from oedematous limbs compared with those from control limbs. No changes were observed for the placebo group.
4. These biochemical changes suggest that benzopyrones can reduce the excess proteinaceous fluid in lymphoedema by increasing the levels of proteinase activity relative to the number of proteinase inhibitors. As a secondary event the amount of fibrosis in the skin is also reduced, presumably by an increase in collagenase activity from the mononuclear phagocytes.
5. These results support the hypothesis that benzopyrones activate the production of proteinases by mononuclear phagocytes. The resultant small peptides can drain locally into the bloodstream, thus bypassing the blocked lymphatics and reducing the protein concentration and its associated oedema fluid.
The 57 mm Thermal Clearance Probe: A Non-Invasive Tool for Measuring Subcutaneous Blood Flow
Authors: Greenhalgh P. M. , Jones J. R. , Yudkin J. S. 
Published: August 2015

1. The segmented thermal clearance probe is a noninvasive instrument which measures heat thermal clearance, a variable directly proportional to superficial blood flow, with a depth sensitivity theoretically proportional to the sensor diameter. We compared an 18 mm sensor and a recently developed 57 mm sensor with the reference technique of xenon washout.
2. The theoretical depth sensitivity of the sensors was assessed using Perspex spacers. Ninety-five per cent of sensitivity had been lost at the respective depths of 3.5 mm and 7.1 mm for the 18 mm and 57 mm sensors.
3. A comparison was made between heat thermal clearance reading and 133Xe decay curves using the two probes for 15 min after injection of 133Xe at 2 mm and 6 mm depths in the anterior thigh in 41 subjects. The 57 mm sensor showed similar correlation with xenon washout at 2 mm injection depth (r = 0.89) and 6 mm injection depth (r = 0.86), whereas the 18 mm sensor showed greater correlation at 2 mm (r = 0.92) than at 6 mm (r = 0.62).
4. The 57 mm sensor was compared with xenon washout at 6 mm in eight insulin-treated diabetic subjects. The relationship was similar to that in non-diabetic subjects (r = 0.79), with no significant difference in slope or intercept.
5. It is concluded that the 57 mm thermal clearance probe may be used to study blood flow at the depth of insulin injection (6 mm) in diabetic and non-diabetic subjects.
Effect of Catecholamines and Insulin on Plasma Volume and Intravascular Mass of Albumin in Man
Authors: Hilsted J. , Christensen N. J. , Larsen S. 
Published: August 2015

1. The effect of intravenous catecholamine infusions and of intravenous insulin on plasma volume and intravascular mass of albumin was investigated in healthy males.
2. Physiological doses of adrenaline (0.5 μg/min and 3 μg/min) increased peripheral venous packed cell volume significantly; intravenous noradrenaline at 0.5 μg/min had no effect on packed cell volume, whereas packed cell volume increased significantly at 3 μg of noradrenaline/min. No significant change in packed cell volume was found during saline infusion.
3. During adrenaline infusion at 6 μg/min, packed cell volume increased, plasma volume decreased and intravascular mass of albumin decreased significantly. During noradrenaline infusion at 6 μg/min, packed cell volume increased and plasma volume decreased, but intravascular mass of albumin did not change.
4. Application of a hyperinsulinaemic, euglycaemic glucose clamp led to an increase in transcapillary escape rate of albumin and a decrease in intravascular mass of albumin. Packed cell volume remained constant, while plasma volume, measured by radiolabeled albumin, decreased.
5. We conclude that the previously reported changes in packed cell volume, plasma volume, intravascular mass of albumin and transcapillary escape rate of albumin during hypoglycaemia may be explained by the combined actions of adrenaline and insulin.
Problems in Measuring Human Leucocyte Cation Content: Effects of Cell Preparation and Handling
Authors: Main J. , Thomas T. H. , Wilkinson R. 
Published: August 2015

1. Previous published measurements of leucocyte cation content are inconsistent, with sodium concentrations having particularly high coefficients of variation. We have measured the effects of recovery time after isolation, different types of handling, and centrifugation on leucocyte sodium and potassium content.
2. Sodium content fell markedly during the first 30 min after isolation and was stable from 1 to 3 h of incubation. There was a small but significant rise in potassium content over the same time period.
3. During incubation, occasional gentle resuspension of the cells gave optimal sodium contents, whereas mixing by inversion caused large falls in sodium and potassium content.
4. Centrifugation of stable cells at 200 g for 6 min caused marked increases in sodium content.
Lipoxin A4 and Lipoxin B4 Inhibit Chemotactic Responses of Human Neutrophils Stimulated by Leukotriene B4 and N-Formyl-l-Methionyl-l-Leucyl-l-Phenylalanine
Authors: Lee Tak H. , Horton Claire E. , Kyan-Aung U. , Haskard Dorian , Crea Atttlio E. G. , Spur Bernd W. 
Published: August 2015

1. Lipoxin A4 (LXA4) and lipoxin B4 (LXB4) have been evaluated for their capacities to modulate neutrophil (PMN) migration and endothelial cell adherence using compounds prepared by total chemical synthesis.
2. Increased PMN migration was seen with concentrations of LXA4 from 10−9 mol/l to 10−7 mol/l. LXA4 was 100-fold less potent than leukotriene B4 (LTB4) and it elicited only one-half of the maximal response of LTB4.
3. The (5S,6S,15S)-isomer of LXA4 induced only a weak migratory response and LXB4 was inactive, suggesting that the activity of LXA4 was stereospecific.
4. Modified chequerboard analysis indicated that LXA4 was a chemokinetic agent.
5. Preincubation of PMN with increasing concentrations of LXA4 induced a very similar dose- and time-dependent inhibition of the subsequent response to 10−7 mol/l LTB4 or 10−7 mol/l N-formyl-l-methionyl-l-leucyl-l-phenylalanine (FMLP). The inhibition was observed at 10−10 mol/l LXA4; the concentration which produced 50% inhibition was 10−8 mol/l and 100% inhibition of PMN locomotion occurred at 10−6 mol/l LXA4.
6. The (5S,6S,15S)-isomers of LXA4 and LXB4 were 5- and 100-fold less potent than LXA4, respectively, in suppressing LTB4- or FMLP-induced PMN migration.
7. Preincubation of PMN with LXA4 led to a suppression of calcium mobilization, as assessed by Quin2-AM fluorescence, when the cells were subsequently stimulated under optimal conditions by LTB4 or FMLP.
8. These results suggest that the inhibitory activity of lipoxins may be related to the capacity of these molecules to regulate calcium ion mobilization.
9. LXA4 and LXB4 did not promote PMN adherence to human endothelial cell monolayers and they did not modulate FMLP-stimulated PMN-endothelial cell adhesion.
Effects of Underfeeding and of Starvation on Thermoregulatory Responses to Cooling in Women
Authors: Mansell P. I. , Macdonald I. A. 
Published: August 2015

1. The effects of acute alterations in energy intake on the thermoregulatory responses to a cooling stimulus were studied in healthy, normal weight, young female subjects. On separate occasions, seven subjects were underfed for 7 days at 60 kJ day−1 kg−1 ideal body weight and six subjects were starved for 48 h. The cooling stimulus was provided by a coverall perfused with water at 16°C.
2. After the application of the cooling stimulus, central body (auditory canal) temperature rose initially in both studies. After underfeeding, the magnitude of this rise in temperature was not significantly different from that seen in the normally fed state. After 48 h starvation, the rise in temperature on cooling was reduced from 0.30 (sem 0.03) to 0.10 (0.04)°C (P &lt; 0.01). In two subjects in whom central body temperature had been maintained in the normally fed state, a fall occurred after starvation.
3. Underfeeding for 7 days did not affect thermogenesis or the degree of vasoconstriction in the forearm or hand in response to cooling.
4. After 48 h starvation, the thermogenic response to cooling was abolished and blood flow in the forearm remained higher than in the normally fed state.
5. In normal weight young females, thermoregulatory responses to a cooling stimulus were therefore substantially affected by 48 h starvation but not by 7 days underfeeding.