bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic and ventilatory responses during very low level exercise
Authors: Goldstein Susan A. , Weissman Charles , Askanazi Jeffrey , Rothkopf Michael , Milic-Emili J. , Kinney John M. 
Published: August 2015

1. Nine male and six female healthy subjects were studied during supine bicycle exercise at workloads of 12 and 37 W; pedalling rates varied between 30 and 50 cycles/min at each workload. Measurements were made of oxygen consumption (Vo2), carbon dioxide production (Vco2), minute ventilation (VE), tidal volume (VT), respiratory frequency (fR), inspiratory and expiratory time (TI, TE) and mean inspiratory flow (VT/TI) using a non-invasive canopy–computer–spirometer system.
2. At rest, males had greater values of VE, VT, TI, inspiratory duty cycle (TI/TTOT), Vco2 and Vo2, and a lower fR, than females.
3. At the lower workload, Vo2, Vco2, VE, VT and VT/TI increased linearly with increasing pedalling rate, whereas at the higher workload there was a decrease in Vo2 and little or no change in ventilatory parameters from 30 to 50 cycles/min except for an increase in fR in females.
4. While performing supine exercise, there was an effect of pedalling rate on ventilatory and metabolic parameters at the low workload (12 W) which diminished at the higher workload (37 W). An increase in pedalling rate appears to enhance efficiency at these low workloads.
5. Differences between the sexes during exercise generally include: (a) a higher breathing frequency, (b) a greater mechanical efficiency, and (c) lower ventilatory equivalents of O2 and CO2 (VE/Vo2 and VE/Vco2) during the higher workload in females than males.
Human atrial natriuretic polypeptide during escape from mineralocorticoid excess in man
Authors: Miyamori Isamu , Ikeda Masatoshi , Matsubara Takao , Okamoto Shinya , Koshida Hideo , Morise Toshio , Takeda Ryoyu 
Published: August 2015

1. Plasma concentrations of human α-atrial natriuretic polypeptide (h-αANP) during escape from the effects of mineralocorticoid excess were determined in six healthy volunteers.
2. Escape, as indicated by an abrupt increase in sodium excretion on the third to sixth day of 9α-fludrocortisone acetate administration (0.6 mg/day), was observed in all subjects.
3. The mean plasma h-αANP level was 30.9 ± sem 8.8 pmol/l on the control day; it increased exponentially in response to 9α-fludrocortisone acetate administration, reached a significant level (114.0 ± 22.4 pmol/l, P &lt; 0.05) on the day before escape and remained elevated during escape.
4. The 24 h creatinine clearance and blood pressure did not change significantly before the escape. Plasma h-αANP increased markedly when the cumulative sodium balance exceeded 220 mmol.
5. These results suggest that h-αANP may play a contributory role in natriuresis and diuresis after mineralocorticoid excess.
Whole body leucine turnover and nutritional status in continuous ambulatory peritoneal dialysis
Authors: Goodship T. H. J. , Lloyd S. , Clague M. B. , Bartlett K. , Ward M. K. , Wilkinson R. 
Published: August 2015

1. Nutritional status and leucine turnover has been measured in ten patients with chronic renal failure before the onset of continuous ambulatory peritoneal dialysis (CAPD) and after 3 months treatment, and in five normal subjects.
2. Somatic muscle protein reserves, as judged by anthropometry and measurement of total body potassium, showed no significant changes after 3 months treatment and were not significantly different from normal.
3. Visceral protein reserves, as judged by serum albumin and plasma amino acids, showed a significant fall after 3 months CAPD and were also lower than in normal subjects.
4. Protein turnover was lower in uraemic than in normal subjects, but the balance between synthesis and breakdown was significantly higher and was maintained after 3 months on CAPD.
Short-term studies on the use of amino acids as an osmotic agent in continuous ambulatory peritoneal dialysis
Authors: Goodship T. H. J. , Lloyd S. , McKenzie P. W. , Earnshaw M. , Smeaton I. , Bartlett K. , Ward M. K. , Wilkinson R. 
Published: August 2015

1. A 1% amino acid dialysis solution with a high concentration of the branched-chain amino acids has been compared with 1.36% glucose in short-term studies.
2. The 1% amino acid solution was as effective an agent as 1.36% glucose with respect to ultrafiltration and clearance of creatinine, urea and potassium.
3. Levels of branched-chain amino acids rose to the upper end of the normal range within 1 h and remained at this level over the entire period of the study. Total and non-essential amino acids had returned to baseline by the end of the cycle.
4. Blood glucose rose to significantly greater levels during the 1.36% glucose exchange than during the 1% amino acid exchange. There was an increase in serum insulin levels during both cycles; this was significantly greater with the 1% amino acid solution than the 1.36% glucose.
5. There was no evidence of short-term metabolic complications with the 1% amino acid solution.
Diurnal change in plasma atrial natriuretic peptide concentrations
Authors: Richards A. M. , Tonolo G. , Fraser R. , Morton J. J. , Leckie B. J. , Ball S. G. , Robertson J. I. S. 
Published: August 2015

1. Diurnal changes in plasma concentrations of atrial natriuretic peptide (ANP), renin, angiotensin II, aldosterone, Cortisol and antidiuretic hormone were investigated in seven normal volunteers studied under standardized conditions of dietary sodium, posture and physical activity. After completion of the diurnal study serial measurements of these variables were continued during, and on recovery from, a 2 day period of severe sodium depletion.
2. Clear diurnal variations in plasma concentrations of renin, angiotensin II, aldosterone, Cortisol and antidiuretic hormone were observed.
3. Plasma ANP concentrations also varied significantly over 24 h. Values peaked about mid-day and a distinct trough in peptide concentrations occurred in the early evening. However, variations in plasma ANP values were of relatively small amplitude and not clearly independent of modest parallel shifts in sodium balance.
4. Changes in plasma ANP concentrations both within the diurnal study period and during sodium deprivation were closely and positively correlated with concomitant changes in cumulative sodium balance.
5. No simple parallel or reciprocal relationships between plasma concentrations of ANP, on the one hand, and concurrent plasma concentrations of other hormones or in the rate of urinary sodium excretion, on the other, were observed during the 25 h of the diurnal study.
Vitamin B12 homoeostasis after haemorrhage in the rat: the importance of skeletal muscle
Authors: Bhatt H. R. , Linnell J. C. 
Published: August 2015

1. The effects of haemorrhage on vitamin B12 (cobalamin) homoeostasis have been studied in rats with and without prior administration of 57Co-labelled cyanocobalamin.
2. Arteriovenous differences in radioactivity and endogenous B12 were measured across the thigh extensor muscles. Radioactivity and endogenous B12 were also measured in skeletal muscle, liver and kidney.
3. Haemorrhage induced a marked rise in circulating B12 with a concomitant loss of the vitamin from skeletal muscle and liver, but in kidney there was a net gain. Restoration of the blood volume with autologous plasma did not prevent release of B12 from tissues.
4. The results suggest that vitamin B12 reserves may be seriously depleted by the wasting of skeletal muscle.
Glucocorticosteroid status in chronic alcoholics with and without skeletal muscle myopathy
Authors: Duane P. , Peters T. J. 
Published: August 2015

1. Chronic alcoholism is associated with a selective atrophy of type II skeletal muscle fibres. We studied the glucocorticoid status of chronic alcoholics with and without myopathy to determine if hypercortisolism is responsible for the myopathy.
2. Twenty-four hour urinary Cortisol excretion and diurnal serum Cortisol measurements were not significantly different in chronic alcoholics, with and without atrophy of type II skeletal muscle fibres.
3. Diurnal serum Cortisol variation was normal for both groups of alcoholics studied. None of the patients with myopathy had raised serum Cortisol levels.
4. We conclude that chronic alcoholic myopathy is not due to alcohol-related pseudo-Cushing's syndrome.
Effect of verapamil on polycythaemia secondary to hypoxia in rats
Authors: Douglas A. R. , Moore-Gillon J. C. , Sheldon J. W. S. , Cameron I. R. 
Published: August 2015

1. Polycythaemia occurs in man secondary to chronic hypoxaemia, and may lead to morbidity from hyperviscosity of the blood. Hypoxaemic rats develop similar changes. We have investigated the effect of the calcium antagonist verapamil upon the polycythaemic response to hypoxia in rats.
2. Control groups of 10 male rats breathed air in an environmental chamber for 28 days. Hypoxic groups breathed a normobaric atmosphere of 10% oxygen for 6 h each day, and air for the remaining 18 h. Control and hypoxic groups were treated with intraperitoneal or subcutaneous water, or with intraperitoneal or subcutaneous water plus verapamil.
3. On day 28, packed cell volume (PCV) was measured by a microhaematocrit technique and red cell mass (RCM) by dilution of injected 51Cr-labelled rat erythrocytes.
4. PCV and RCM were significantly higher in all the hypoxic groups compared with the control groups (P &lt; 0.01 in each case).
5. PCV and RCM were significantly lower in the hypoxic groups treated with intraperitoneal or subcutaneous verapamil than in the hypoxic groups treated with intraperitoneal or subcutaneous water (P &lt; 0.01). There were no significant differences between PCV and RCM in verapamil- and water-treated normoxic control groups. Verapamil had no effect on the shift of the oxygen/haemoglobin dissociation curve produced by hypoxia.
6. Verapamil reduces the polycythaemic response to repeated intermittent hypoxia in rats. Venesection is usually performed for excessive secondary polycythaemia in man. Our results suggest a possible therapeutic role for verapamil in such individuals.
Muscle strength in the triceps surae and objectively measured customary walking activity in men and women over 65 years of age
Authors: Bassey E. J. , Bendall M. J. , Pearson M. 
Published: August 2015

1. Objective measurements of the maximal voluntary strength of triceps surae and the amount and speed of customary walking have been made in 56 men and 66 women aged over 65 years, who were living independently.
2. Strength was measured using a dynamometer based upon a hydraulic system (Bourdon tube). Walking was assessed, for amount using a mechanical accelerometer (pedometer) over a week, and for speed using a self-paced test for normal walking over 100 m on the level. The reliability and validity of these methods has been described.
3. The men were significantly stronger (1128 ± 206 vs 873 ± 177 N) even after adjustment for body weight; their amount of walking was similar to that of women, but they walked significantly faster (4.8 ±0.6 vs 4.2 ±0.6 km/h). Men were significantly more active in leisure pursuits (as assessed by questionnaire).
4. Significant associations between strength and chosen normal walking speed were found for both sexes (r = 0.41, P &lt; 0.001 for men and r = 0.36, P &lt; 0.01 for women). The amount of walking (daily stepscore as a mean from 7 consecutive days recorded) was significantly but less strongly correlated with strength (r = 0.30, P &lt; 0.05) in the men only.
5. Multiple regression analysis showed that in men neither age nor amount of walking had any further effect in addition to speed, but in women age had an additional effect (multiple R = 0.48).
6. An association has been demonstrated which raises the possibility of reversing loss of muscle strength through increased daily activity.
Plasma [3H]noradrenaline kinetics in man: is separation of alumina extracts by high performance liquid chromatography necessary?
Authors: McCance Alastair J. , Forfar J. Colin 
Published: August 2015

1. After an 80 min intravenous infusion of 1-[3H]noradrenaline ([3H]NA) in 19 subjects, the proportion of alumina-extractable 3H due to [3H]NA was 86 ± 2% in arterial and 78 ± 2% in venous plasma. [3H]Dihydroxy-phenylethyleneglycol ([3H]DHPG) accounted for 8 ± 1% in arterial and 13 ± 1% in venous plasma. [3H]Dihydroxymandelic acid ([3H]DOMA) was not detected.
2. No time-dependent change in the proportion of alumina-extractable 3H due to [3H]NA was seen in either arterial or venous plasma over this period. In venous plasma the proportion of alumina-extractable 3H due to [3H]DHPG increased slightly between 30 and 80 min, from 10 ± 1% to 13 ± 1%.
3. The results were unchanged with chronic β-blockade and with either 1-[2,5,6-3H]NA or 1-[7,8-3H]NA.
4. After [3H]NA infusion in man the radioactivity recovered after alumina extraction is predominantly [3H]NA and thus can be used directly to determine [3H]NA kinetics without the need for metabolite separation.
Abnormal diurnal variation in salt and water excretion in patients with obstructive sleep apnoea
Authors: Warley A. R. H. , Stradling J. R. 
Published: August 2015

1. In healthy individuals, sleep is associated with a fall in urine and sodium output.
2. Seven male patients with obstructive sleep apnoea exhibited a paradoxical rise in both urine and sodium output during the hours of sleep.
3. Continuous positive airway pressure applied via the nose abolished both the apnoea and the nocturnal rise in urine and sodium output, thereby restoring the diurnal pattern towards normal.
Decreased density of binding sites for atrial natriuretic peptide on platelets of patients with severe congestive heart failure
Authors: Schiffrin Ernesto L. 
Published: August 2015

1. Binding sites for atrial natriuretic peptide (ANP) with a specificity similar to that of vascular ANP receptors have been demonstrated previously in human platelets. The density of these binding sites for ANP on platelets is decreased after increased dietary sodium intake, when plasma ANP levels increase. ANP-binding sites were investigated in patients with severe congestive heart failure (CHF), a condition in which there is an increase in the concentration of ANP in plasma.
2. In 24 patients with a clinical diagnosis of functional class III–IV CHF, plasma ANP (90.3 ± 13.4 fmol/ml, mean ± sem) was significantly higher (P &lt; 0.001) than in 16 age-matched patients without cardiac disease (15.4 ± 2.0 fmol/ml). The density of ANP-binding sites on platelets was significantly lower (P &lt; 0.01) in the 24 CHF patients (6.3 ± 0.8 fmol/109 cells) than in the non-cardiac patients (11.8 ± 1.4 fmol/109 cells). There was no significant difference in affinity of the ANP-binding sites between both groups. There was a significiant non-linear inverse correlation of the density of ANP-binding sites on platelets with plasma ANP concentration. These results could not be explained by prior receptor occupancy secondary to the elevated concentration of circulating ANP.
3. In conclusion, ANP-binding sites on platelets are decreased in patients with severe CHF and with significantly elevated concentration of ANP in plasma.
Inherited glomerular properties and their role in the expression of various forms of experimental glomerular injury
Authors: Chandrachud Lata , Jones J. M. Boulton 
Published: August 2015

1. Glomeruli possess properties which vary between Lewis and DA strains of rat.
2. These properties may account for differences in the expression of various forms of experimental glomerular injury.
3. The difference in susceptibility to Heymann nephritis in the Lewis strain was confirmed.
4. Chronic serum sickness induced by cationic human serum albumin led to capillary loop deposits in Lewis rats, whereas DA rats had mesangial deposits of rat immunoglobulin G even in control kidneys.
5. Lewis rats developed proteinuria after infusion of the polycation hexadimethrine whereas DA rats did not.
6. DA rats developed greater proteinuria after injection of puromycin aminonucleoside.
7. These results support the hypothesis that an individual's susceptibility to different forms of glomerulonephritis may result from their glomerular properties and not necessarily from their immune responses.
Ventilation and breathlessness on maximal exercise in patients with interstitial lung disease after local anaesthetic aerosol inhalation
Authors: Winning A. J. , Hamilton R. D. , Guz A. 
Published: August 2015

1. The ventilatory response to maximal incremental exercise and the accompanying sensation of breathlessness were studied after the inhalation of 0.9% sodium chloride (saline) and 5% bupivacaine aerosols in six patients with interstitial lung disease.
2. The adequacy of airway anaesthesia induced by bupivacaine aerosol was confirmed by the absence of the cough reflex to 5% citric acid aerosol on completion of exercise.
3. All subjects first performed a trial exercise test to familiarize them with the procedure and to assess the degree of arterial oxygen desaturation on exercise. In subsequent tests, supplementary oxygen was given to maintain the saturation at 95% or above.
4. Airway anaesthesia had no effect on the ability to perform exercise as assessed by maximum workload, CO2 production or heart rate. No significant changes were seen on the pattern of breathing, minute ventilation or endtidal Pco2 on exercise. There was, however, a small but statistically significant increase in ventilation related to CO2 production (VE/Vco2) at the end of exercise.
5. There was a tendency for breathlessness to be increased by airway anaesthesia but this did not reach statistical significance.
6. These results provide no evidence that vagal afferent activity is responsible for the abnormal ventilatory response to exercise in patients with interstitial lung disease. The perception of breathlessness in these patients was not diminished by anaesthesia of the airway.
A DNA polymorphism of the apolipoprotein C-III gene in extracoronary atherosclerosis
Authors: O'Connor G. , Stocks J. , Lumley J. , Galton D. J. 
Published: August 2015

1. A genetic polymorphism of apolipoprotein (apo) C-III was studied in 49 Caucasian patients with extra-coronary atherosclerosis demonstrated by angiography.
2. Twelve patients (24%) possessed an uncommon allelic variant of the apo A-I/C-III gene cluster compared with two (4%) in 50 healthy controls (P &lt; 0.01).
3. Of 27 patients with carotid atherosclerosis, 22% had the uncommon genotype (P &lt; 0.02), and in aortofemoral atherosclerosis (n = 22) 27% possessed the uncommon variant (P &lt; 0.01).
4. When normotriglyceridaemic subgroups (n = 32) with arterial disease were studied the difference in genotype frequencies persisted, 22% having the uncommon allele (P &lt; 0.01), suggesting that such genetic variants have effects independent of circulating levels of plasma lipids.
Effect of high protein intake on sodium, potassium-dependent adenosine triphosphatase activity in the thick ascending limb of Henle's loop in the rat
Authors: Bouby Nadine , Bankir Lise 
Published: August 2015

1. We have previously shown that the hypertrophy of the kidney induced by a high protein diet consists of a preferential hypertrophy of the thick ascending limb (TAL) of Henle's loop. This might be related to an increase in the active salt transport by this segment. Sodium, potassium-dependent adenosine triphosphatase (Na+,K+-ATPase) activity was measured in TAL from kidneys of rats fed either a low (LP) or a high (HP) protein diet for several weeks.
2. Enzymatic activity was measured by microdensitometry, after appropriate cytochemical reaction, for an adenosine 5′-triphosphate (ATP) concentration of 0–66 mmol/l. Both activity per unit tubular length and mean activity per unit tissue volume were recorded. A calibration was designed to convert usual microdensitometry units (extinction) into conventional biochemical units (mol of product formed).
3. For non-limiting substrate concentrations, the Na+,K+-ATPase activity, expressed per unit length of tubule on the sections, was 50% higher in HP than in LP rats, an increase proportional to that of the simultaneously measured tubule diameter. When expressed per unit tubular volume, Na+,K+-ATPase activity was similar in both groups of rats. The dissociation constant for ATP was also similar in both groups.
4. Results show that a high protein diet induces an increase in Na+,K+-ATPase activity in TAL, thus enabling an enhanced NaCl transport in this segment. This increase in transport capacity is not due to an increase in the density of enzymatic units but to an increase in their number, in relation to the hypertrophy of the TAL.
Renal transplantation: HLA-linked, non-cytotoxic antibodies develop after blood transfusion
Authors: MacLeod Alison M. , Stewart Keith N. , Urbaniak Stanislaw , Catto Graeme R. D. 
Published: August 2015

1. A previously untransfused dialysis patient was given blood from a single donor on three occasions and sera were obtained from the recipient before and after transfusion.
2. The sera were tested against B-lymphocytes from the blood donor and his family in the erythrocyte–antibody rosette inhibition assay to determine whether any Fc-receptor-blocking activity which developed was HLA linked.
3. Antibody activity was noted after the second transfusion and was directed toward B-lymphocytes from the blood donor and his family members sharing the haplotype HLA A11, B12 with him.
4. These antibodies were removed by the absorption of active sera with lymphocytes from the blood donor but not from (a) his sibling who shared no HLA antigens with him or (b) the transfusion recipient. Absorption of the active sera with platelets from the blood donor did not remove activity.
5. These results indicate that Fc-receptor-blocking antibodies developing after blood transfusion are directed to HLA-linked antigens on donor lymphocytes.
Hepatic cholesterol synthesis and esterification in rats after chronic ethanol feeding
Authors: Venkatesan S. , Simpson K. J. , Peters T. J. 
Published: August 2015

1. Chronic (5 weeks) alcohol-fed and isocaloric glucose pair-fed control rats had similar body weights, liver weights and liver protein contents.
2. Hepatic esterified cholesterol and triacylglycerol levels were two- to three-fold higher in alcohol-fed rats than in controls.
3. Hepatic cholesterol synthesis rates measured in vivo with 3H2O were significantly reduced in alcohol-fed rats.
4. Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (NADPH) (EC 1.1.1.34) activity was increased and the apparent Km for 3-hydroxymethyl-3-glutaryl-CoA was decreased in alcohol-fed rats.
5. Hepatic acyl-CoA:cholesterol acyltransferase (cholesterol acyltransferase; EC 2.3.1.26) activity was significantly increased in alcohol-fed rats.
6. These results indicate that there is no direct relationship between 3-hydroxy-3-methylglutaryl-CoA reductase activity and sterol synthesis in liver of alcohol-fed rats.
Acute effects of ethanol on protein synthesis in different muscles and muscle protein fractions of the rat
Authors: Preedy Victor R. , Peters Timothy J. 
Published: August 2015

1. The effects of a single dose of ethanol (75 mmol/kg body weight) on rates of muscle protein synthesis were examined in young rats. Fractional rates of protein synthesis were measured in the soleus, plantaris, gastrocnemius, diaphragm and stomach by the large ‘flooding-dose’ technique.
2. After 150 min, the fractional synthesis rates of all muscles were reduced by 15–35%. Skeletal muscles containing a predominance of anaerobic (fast-twitch, type II) fibres showed greater changes when compared with skeletal muscles with a predominance of aerobic (slow-twitch, type I) fibres.
3. Gastrocnemius muscles were separated into sarcoplasmic, stromal and myofibrillar protein fractions. Protein synthesis was reduced similarly in all fractions by ethanol treatment, by approximately 30%.
4. As skeletal muscle mass comprises 40% of body weight, the responses have important physiological implications and may also be responsible for the muscle atrophy observed in alcoholic patients.