bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of adrenaline infusion on fatty acid and glucose turnover in lean and obese human subjects in the post-absorptive and fed states
Authors: Connacher Alan A. , Bennet William M. , Jung Roland T. , Bier Dennis M. , Smith Christopher C. T. , Scrimgeour Charles M. , Rennie Michael J. 
Published: August 2015

1. Energy expenditure, plasma glucose and palmitate kinetics and leg glycerol release were determined simultaneously both before and during adrenaline infusion in lean and obese human subjects. Seven lean subjects (mean 96.5% of ideal body weight) were studied in the post-absorptive state and also during mixed nutrient liquid feeding, eight obese subjects (mean 165% of ideal body weight) were studied in the post-absorptive state and six obese subjects (mean 174% of ideal body weight) were studied during feeding.
2. Resting energy expenditure was higher in the obese subjects, but the thermic response to adrenaline, both in absolute and percentage terms, was similar in lean and obese subjects. Plasma adrenaline concentrations attained (3 nmol/l) were comparable in all groups and the infusion had no differential effects on the plasma insulin concentration. Before adrenaline infusion the plasma glucose flux was higher in the obese than in the lean subjects in the fed state only (45.8 ± 3.8 versus 36.6 ± 1.0 mmol/h, P &lt;0.05); it increased to the same extent in both groups with the adrenaline infusion.
3. Before the adrenaline infusion plasma palmitate flux was higher in the obese than in the lean subjects (by 51%, P &lt;0.01, in the post-absorptive state and by 78%, P &lt;0.05, in the fed state). However, there was no significant change during adrenaline infusion in the obese subjects (from 13.5 ± 1.00 to 15.0 ± 1.84 mmol/h, not significant, in the post-absorptive state and from 14.4 ± 2.13 to 15.7 ± 1.74 mmol/h, not significant, in the fed state), whereas there were increases in the lean subjects (from 8.93 ± 1.10 to 11.2 ± 1.19 mmol/h, P &lt;0.05, in the post-absorptive state, and from 8.06 ± 1.19 to 9.86 ± 0.93 mmol/h, P &lt;0.05, in the fed state).
4. Before adrenaline infusion the palmitate oxidation rate was also higher in the obese than in the lean subjects (1.86 ± 0.14 versus 1.22 ± .09 mmol/h, P &lt;0.01, in the post-absorptive state and 1,73 ± 0.25 versus 1.12 ± 0.12 mmol/h, P &lt;0.05, in the fed state). However, in response to adrenaline the fractional oxidation rate (% of flux) increased less in the obese than in the lean subjects, especially in the post-absorptive state (from 13.8 ± 1.02 to 14.9 ± 1.39%, not significant, versus from 13.7 ± 0.98 to 19.3 ± 1.92%, P &lt;0.05). These effects were independent of feeding. Leg glycerol release increased more in the lean subjects with adrenaline infusion, although increases in the plasma glycerol concentration did not differ between the groups.
5. These results suggest that in obese subjects plasma inter-organ transport of fatty acids and the subsequent fractional oxidation responses favour storage of triacylglycerol. These factors may be important determinants for the development and maintenance of the obese state.
Observations on the chemical nature of lead in human blood serum
Authors: Al-Modhefer A. J. A. , Bradbury M. W. B. , Simons T. J. B. 
Published: August 2015

1. The binding of lead to human blood serum, and components of serum, was studied by titration with the addition of Pb(NO3)2 solution, monitoring the free Pb2+ concentration with a Pb2+ electrode, and by equilibrium dialysis.
2. In fresh serum, about 4999 out of 5000 parts of added lead were bound. This suggests that the free Pb2+ concentration is around 1/5000th of the total lead concentration in the serum of normal subjects, i.e. about 1 × 10−12 mol/l.
3. About 60% of the binding of lead in serum is abolished by standing in air, by dialysis or by treatment with N-ethylmaleimide. This appears to be due to the presence of thiol compounds, mainly cysteine. The remaining 40% appears to be due to protein, mainly albumin.
Persistent albuminuria in normotensive non-insulin-dependent (type II) diabetic patients: comparative effects of angiotensin-converting enzyme inhibitors and β-adrenoceptor blockers
Authors: Stornello Michele , Valvo Enrico V. , Scapellato Luigi 
Published: August 2015

1. Some non-insulin-dependent (type II) diabetic patients show albuminuria without arterial hypertension. In these patients, angiotensin-converting enzyme inhibitors reduce urinary albumin excretion without producing any changes in systemic blood pressure and renal haemodynamics. However, up to now it has not been clear whether these favourable renal effects are specifically related to angiotensin-converting enzyme inhibition or not.
2. Twelve type II diabetic outpatients with persistent macroalbuminuria (greater than 300 mg/daily on at least three consecutive occasions), without any other signs of renal disease and whose blood pressure was persistently below 140/90 mmHg, were studied.
3. In a randomized sequence and in a double-blind fashion, after a 2-month run-in period, patients were allocated to receive 5 mg of enalapril or 50 mg of atenolol daily for the next 6 months. At the end of this first period and after 6 months on placebo in a cross-over fashion, active treatment was replicated. Blood pressure and urinary albumin excretion were measured every 2 months, whereas the other variables studied were determined at the end of each period.
4. Kidney function and blood pressure did not change significantly, whereas albuminuria decreased significantly, after both of the drugs.
5. These data suggest that the inhibition of tissue angiotensin formation and the consequent reduction in glomerular permeability, rather than changes in renal and systemic haemodynamics, are the common mechanisms by which both enalapril and atenolol decreased albuminuria in our patients.
Model-based determination of cut-off values for left ventricular hypertrophy from echocardiographic myocardial mass data
Authors: Morvan Daniel , Golmard Jean-Louis , Komajda Michel , Drobinski Gérard 
Published: August 2015

1. The left ventricular myocardial mass is a measurement that is easy to obtain by echocardiography. It is currently used for the definition of left ventricular hypertrophy, but cut-off values are often critical, since they depend on covariates of left ventricular myocardial mass such as sex, age, body surface area, physical training, blood pressure, etc. As it is very difficult in any laboratory to obtain a sufficient number of normal subjects for the establishment of left ventricular myocardial mass experimental distributions, we propose a non-linear model for the calculation of echocardiographic left ventricular myocardial mass distribution in normal subjects, from personal and literature data. Left ventricular myocardial mass probability density function was computed from the following two assumptions: the joint distribution of the internal and external left ventricular diameters is assumed to be bivariate normal, and the relation between left ventricular myocardial mass and ventricular diameters is given by the formula of Devereux & Reicheck (Devereux, R. B. & Reicheck, N. Circulation 1977; 55, 613-8).
2. The Gaussian assumption was tested by using skewness tests. The model was further developed for the myocardial mass index distribution. The calculated probability density functions were compared with experimental data and showed very good agreement. Furthermore, they were used to define cut-off values of left ventricular hypertrophy at selected false-positive ratios. Finally, since left ventricular myocardial mass may vary under normal conditions with co-variates, the model may provide co-variate-matched cut-off values for any, even small, series of non-diseased control subjects.
Effects of chronic administration of ephedrine during very-low-calorie diets on energy expenditure, protein metabolism and hormone levels in obese subjects
Authors: Pasquali Renato , Casimirri Francesco , Melchionda Nazario , Grossi Gabriele , Bortoluzzi Lucia , Labate Antonio Maria Morselli , Stefanini Chiara , Raitano Antonino 
Published: August 2015

1. We investigated the effects of the chronic administration of a sympathomimetic agent on energy expenditure, protein metabolism and levels of thyroid hormones and catecholamines in 10 obese subjects after a 6-week very-low-calorie-diet programme (1965 kJ, 60 g of protein, 45 g of carbohydrates). l-(-)-Ephedrine hydrochloride (50 mg three times a day by mouth) or placebo were administered during 2-week periods (weeks 2-5 of the VLCD programme) in a randomized, double-blind, crossover design. Five subjects began with ephedrine and five with placebo.
2. The results were analysed separately in the two groups. No difference was found between them as regards weight loss during the very-low-calorie diet and drug treatments. Conversely, ephedrine therapy induced a significantly lower daily urinary excretion of nitrogen (and, consequently, a better nitrogen balance) with respect to placebo, independently of the drug sequence. Daily urinary levels of 3-methylhistidine during ephedrine and placebo treatments were similar. The fasting resting metabolic rate (oxygen consumption, ml STP/min) fell significantly during the very-low-calorie diet in both groups, but this effect was partially and significantly prevented by administration of ephedrine. Diet therapy significantly reduced 24 h urine levels of vanillylmandelic acid and homovanillic acid, which, however, increased to pretreatment values during ephedrine treatment. No significant effects were shown on 24 h urinary concentrations of adrenaline, noradrenaline and dopamine during the very-low-calorie diet and/or ephedrine treatment. There were also no effects on the serum levels of thyrotropin, thyroxine, free-tri-iodothyronine and free-thyroxine, but ephedrine significantly prevented a further fall in the serum tri-iodothyronine level and the serum triiodothyronine/thyroxine ratio during the very-low-calorie diet.
3. These findings demonstrate that in obese subjects following a very-low-calorie-diet programme, administration of chronic adrenoceptor agonists, such as ephedrine, partially prevented the fall in resting metabolic rate and significantly improved the nitrogen balance. These effects may be of importance in the treatment of patients in whom a reduced capacity for energy expenditure may be involved in their obese state.
Correlation of the ratio of S-adenosyl-l-methionine to S-adenosyl-l-homocysteine in the brain and cerebrospinal fluid of the pig: implications for the determination of this methylation ratio in human brain
Authors: Weir D. G. , Molloy A. M. , Keating J. N. , Young P. B. , Kennedy S. , Kennedy D. G. , Scott J. M. 
Published: August 2015

1. Pigs were maintained in air or in an atmosphere of nitrous oxide which dramatically changes the S-adenosyl-l-methionine to S-adenosyl-l-homocysteine ratio in neural tissues. Samples of cerebrospinal fluid, cortex, cerebellum and spinal cord were then extracted and analysed for S-adenosyl-l-methionine and S-adenosyl-l-homocysteine. Regression analyses were carried out on values obtained in cerebrospinal fluid and in neural tissues.
2. Highly significant correlations were obtained between levels of S-adenosyl-l-homocysteine (r2 = 0.42-0.69; P &lt; 0.001) and S-adenosyl-l-methionine/S-adenosyl-l-homocysteine ratios (r2 = 0.56-0.65; P &lt; 0.001) in cerebrospinal fluid and levels and ratios in cortex, cerebellum and spinal cord. The levels of S-adenosyl-l-methionine did not show a significant correlation.
3. We conclude that the ratio of these metabolites in the cerebrospinal fluid may reflect the ratio in the central nervous system and we suggest that this may also be true in human tissues. This finding will permit the determination of the probable methylation ratio in the central nervous system in human conditions, such as vitamin B12 deficiency and acquired immune deficiency syndrome, where a similar myelopathy occurs to that seen in the nitrous oxide-treated pig. All three myelopathies may arise from an inhibition of methyltransferases involved in the synthesis of myelin that would occur when the methylation ratio is reduced.
Renal haemodynamic, hormonal and excretory effects of low-dose atrial natriuretic factor infusion in renal transplant recipients
Authors: Lipkin G. W. , Dawnay A. B. S. , Harwood S. M. , Kendall R. G. , Cattell W. R. , Raine A. E. G. 
Published: August 2015

1. In experimental studies, activation of renal sympathetic nerves attenuates the natriuretic response to atrial natriuretic factor. We therefore investigated the response to low-dose infusion of atrial natriuretic factor in renal transplant recipients.
2. Eight male cyclosporin-treated renal transplant recipients received human-α atrial natriuretic factor (1–28) at a dose of 1.2 pmol min−1 kg−1 or placebo for 2 h in a placebo-controlled, randomized, cross-over study. The plasma atrial natriuretic factor concentration rose from 18.5 to 49.2 pmol/l in association with an immediate natriuresis (a rise of 49.1 μmol/min in the first 30 min, P&lt;0.05; peaking at a 61% increase from baseline, P&lt;0.01), diuresis (from 3.37 to 7.46 ml/min) and a threefold rise in urinary cyclic GMP excretion.
3. In response to infusion of atrial natriuretic factor, the packed cell volume rose by 4.2% (P &lt; 0.001) and the filtration fraction by 5% (from 22 to 27%, P&lt;0.05), but there was no significant change in renal plasma flow, glomerular filtration rate or mean arterial blood pressure. Likewise, the plasma catecholamine concentrations, plasma renin activity and serum erythropoietin concentration remained unchanged.
4. The sensitivity of the renal allograft to plasma atrial natriuretic factor concentrations in the high physiological range suggests a role for endogenous atrial natriuretic factor in the modulation of graft function. Furthermore, the immediate natriuretic response to atrial natriuretic factor in the effectively denervated transplant kidney, in contrast to the delayed response seen in normal subjects, may imply that sympathetic nerves have an inhibitory effect on the renal response to atrial natriuretic factor in normal man.
5. In contrast to the findings of studies in vitro, infusion of atrial natriuretic factor had no effect on the serum erythropoietin concentration.
Mutual interactions of respiratory sinus arrhythmia and the carotid baroreceptor-heart rate reflex
Authors: Cross S. J. , Cowie M. R. , Rawles J. M. 
Published: August 2015

1. In six healthy subjects the amplitude and phase of respiratory sinus arrhythmia were determined at five different respiratory cycle lengths ranging from 3 to 9.5 s.
2. At each respiratory cycle length the carotid baroreceptor-heart rate reflex response was determined by cyclical neck suction at −40 mmHg at five different cycle lengths covering the same range of 3–9.5 s.
3. The application of cyclical neck suction increased the amplitude of respiratory sinus arrhythmia in all but the longest respiratory cycle lengths.
4. With increasing respiratory cycle length the amplitude of sinus arrhythmia increased, and R-R intervals were at their longest at an earlier phase of the respiratory cycle. Similarly, with increasing suction cycle length the amplitude of the cardiac interval response increased and the phase angle decreased.
5. The cardiac interval responses to respiration and to neck suction at different frequencies were independent of each other, the heart rate at any moment resulting from the algebraic summation of the two responses.
Comparative study of pressor and heart rate responses to angiotensin II and noradrenaline in pregnant and non-pregnant women
Authors: Ramsay Margaret , Pipkin Fiona Broughton , Rubin Peter 
Published: August 2015

1. Twenty-eight healthy non-pregnant women and 28 women in the first or second trimester of pregnancy were studied. They were given an incremental intravenous infusion of either noradrenaline or angiotensin II. Pressor and heart rate responses were documented.
2. Dose-pressor response curves were constructed for the two agents in pregnant and non-pregnant women (n=14 in each group). The regression parameters of slope and intercept were calculated, and were used to derive the variables of dose required to elicit a 10 mmHg rise in systolic or diastolic blood pressure.
3. The pressor response to angiotensin II was diminished in pregnancy, with approximately twice the dose being required to raise the systolic or diastolic arterial blood pressure as in non-pregnant subjects.
4. The systolic pressor response to noradrenaline was slightly diminished in pregnancy, but the diastolic pressor response was unchanged. There were no significant differences between the doses of noradrenaline required to elicit a 10 mmHg rise in systolic or diastolic arterial blood pressure in pregnant or non-pregnant subjects.
5. There was a diminution in the bradycardia evoked in response to both hormones in pregnancy.
6. We conclude that the well-documented pressor insensitivity to angiotensin II during pregnancy is a specific phenomenon, not a manifestation of a generalized reduction in vascular reactivity.
Effects of methotrexate on rat liver regeneration after partial hepatectomy
Authors: Tsukamoto Ikuyo , Kojo Shosuke 
Published: August 2015

1. Methotrexate was administered immediately after partial (70%) hepatectomy, resulting in complete inhibition of dihydrofolate reductase in 24 h-regenerating liver.
2. At 48 h and 72 h after partial hepatectomy, thymidylate synthase activity was increased, whereas thymidine kinase was inhibited, by the injection of methotrexate. The DNA and RNA contents and the liver weight were also reduced in methotrexate-treated rats.
3. The immunoblotting assay showed that methotrexate stimulated the synthesis of thymidylate synthase protein in 48 h-regenerating liver. At the same time, thymidylate synthase activity was directly inhibited by methotrexate. The mechanisms of inhibition of these enzymes by methotrexate appeared to be different.
Effects of early amino acid administration during total parenteral nutrition on protein metabolism in pre-term infants
Authors: van Lingen R. A. , van Goudoever J. B. , Luijendijk I. H. T. , Wattimena J. L. D. , Sauer P. J. J. 
Published: August 2015

1. We investigated the effects of starting amino acid administration on post-natal day 2 on protein turnover and nitrogen balance in appropriate-for-gestational-age, very-low-birth-weight infants. Eighteen infants were divided into two groups. Group A received from day 2 onwards an amino acid solution, whereas group B started on this solution after day 4. Both groups were exclusively parenterally fed, 200 kJ day−1 kg−1 on post-natal days 3 and 4. Group A (birth weight 1.5 ± 0.3 kg) received 4.6 g of glucose, 1.9 g of fat and 2.3 g of amino acids day−1 kg−1 body weight. Group B (birth weight 1.4 ± 0.2 kg) received 7.0 g of glucose and 1.9 g of fat day−1 kg−1 body weight.
2. At post-natal day 3, a primed constant infusion of 3 mg of [15N]glycine day−1 kg−1 was given. Protein flux, protein synthesis and protein breakdown were calculated from the 15N enrichment in urinary ammonia. In five out of nine infants in group B no plateau of 15N enrichment in urinary urea could be detected, whereas in group A two out of nine infants did not reach a plateau. For this reason we did not use the end product urea for our calculations.
3. The administration of the amino acids resulted in a higher protein flux (6.9 ± 1.5 g day−1 kg−1 versus 5.2 ± 0.9 g day−1 kg−1) and a higher protein synthesis rate (6.0 ± 1.4 g day−1 kg−1 versus 4.6 ± 0.8 g day−1 kg−1) in group A. There was no statistically significant difference in protein breakdown. The administration of amino acids reversed a negative protein balance (−0.6 ± 0.2 g day−1 kg−1) into a positive one (1.4 ± 0.2 g day−1 kg−1. No adverse effects of the amino acid infusion were seen.
4. We conclude that the early introduction of amino acids has, even at this relatively low energy intake of 200 kJ day−1 kg−1, a positive effect on protein balance by increasing protein synthesis.
Contractile properties and susceptibility to exercise-induced damage of normal and mdx mouse tibialis anterior muscle
Authors: Sacco P. , Jones D. A. , Dick J. R. T. , Vrbová G. 
Published: August 2015

1. The functional properties of tibialis anterior muscles of normal adult (C57BL/10) and age-matched dystrophin-deficient (C57BL/10 mdx) mice have been investigated in situ. Comparisons were made between tibialis anterior muscle strength, rates of force development and relaxation, force-frequency responses and fatiguability. Subjecting mdx and C57 muscles to a regimen of eccentric exercise allowed the hypothesis to be tested that dystrophin-deficient muscles are more susceptible to exercise-induced muscle damage.
2. mdx muscles were, on average, 30% stronger than C57 muscles and almost 80% heavier, but both had similar muscle lengths. Thus, although mdx muscles were stronger in absolute terms, their estimated force per unit cross-sectional area was significantly less than that of C57 muscles.
3. The force-frequency relationships of C57 and mdx muscles differed in that whilst, at 40 Hz, the former developed 70% of the force developed at 100 Hz, the latter developed only 55% of the maximal force. Twitch force was normal in mdx muscles, but contraction time was shortened, and the consequent reduction in fusion frequency probably explains the force-frequency differences observed between the two groups.
4. mdx muscles were less fatiguable than normal muscles when stimulated repeatedly at a frequency of 40 Hz. It is possible that the lower relative force at 40 Hz in mdx muscles entailed a lower energy demand and thus a slower rate of fatigue than seen in normal muscles.
5. Eccentrically exercised C57 muscles showed a large loss of maximal force for up to 12 days after exercise. Maximal force loss occurred 3 days after exercise (55% of non-exercised tibialis anterior muscle), which also corresponded with the period of greatest fibre necrosis. C57 muscles showed a significantly reduced 40 Hz/100 Hz force-frequency ratio at 1 and 3 days after exercise. This was primarily due to a reduced twitch amplitude rather than to a change in the time course of the twitch. It is unlikely, therefore, that the altered contractile characteristics of mdx muscle were a result of the presence of damaged but otherwise normal fibres.
6. C57 and mdx tibialis anterior muscles displayed similar degrees of force loss after exercise. Furthermore, the rate of recovery after the nadir of force loss was very similar for the two groups. By 12 days after exercise, force recovered to 76% and 80% of control in C57 and mdx muscles, respectively. Our findings do not support the hypothesis that dystrophin-deficient muscle is more susceptible to exercise-induced muscle damage.