bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in fat and Carbohydrate Metabolism Caused by Moderate Exercise in Patients with Acromegaly
Authors: Johnson R. H. , Rennie M. J. 
Published: August 2015

1. Seven patients with acromegaly and nine controls were studied before, during and after 30 min of moderate steady exercise on a bicycle ergometer. Venous blood samples were taken for estimation of growth hormone (HGH), immunoreactive insulin (IRI), pyruvate, lactate, glucose, free fatty acids (FFA), glycerol and ketone bodies.
2. Exercise caused a rise in HGH concentrations in the acromegalic patients, despite their pituitary tumour, and also in control subjects. Concentrations of IRI fell during exercise in control subjects, but rose in the acromegalic patients.
3. Concentrations of glycerol, FFA and ketone bodies rose rapidly to a maximum during exercise in the acromegalics and appeared to be suppressed before the end of exercise: there was no increase in the concentration of ketone bodies after exercise. In control subjects there was a gradual increase in glycerol and FFA concentrations towards the end of exercise, but no change in ketone bodies occurred until the post-exercise period, when ketone-body concentrations rose.
4. We conclude that exercise causes remarkable differences in metabolite concentrations in the blood of acromegalic patients compared with controls, with the concentration of fat metabolites reaching a maximum, then decreasing during the period of constant exercise. There was also elevation, instead of the normal fall, of plasma IRI activity and it is suggested that the decreased concentration of fat metabolites occurred because of the change of insulin concentration. It is further suggested that in acromegaly insulin retains its effect on re-esterification of fat in spite of resistance to its effects on carbohydrate metabolism.
Plasma Zinc in Pre- and Post-Menopausal Women: Its Relationship to Oestrogen Therapy
Authors: Aitken J. M. , Lindsay R. , Hart D. McKay 
Published: August 2015

1. The specific gravity and zinc concentration of plasma obtained during fasting were measured in pre- and post-menopausal women. A number of the latter had been taking 20–40 μg of mestranol daily for at least 1 year.
2. A highly significant correlation was found between plasma zinc concentration and plasma specific gravity in the oophorectomized women who were not receiving oestrogens.
3. The mean plasma zinc concentration was 2 μg/100 ml lower in the pre-menopausal women than in the oophorectomized controls, and this was wholly consistent with the associated fall in plasma specific gravity.
4. The mean plasma zinc concentration in the mestranol-treated women was 12 μg/100 ml lower than that found in the oophorectomized controls, and could not be attributed to the small associated change in plasma specific gravity.
5. It is suggested that the fall in plasma zinc concentration associated with mestranol therapy could be due to either a qualitative change in the plasma proteins or to relative zinc depletion.
Long-Term Variation in Plasma Activities of Aspartate Transaminase and Alkaline Phosphatase in Health
Authors: Levin G. E. , McPherson C. K. , Fraser Patricia M. , Baron D. N. 
Published: August 2015

1. Plasma aspartate transaminase and alkaline phosphatase activities were measured weekly for approximately 30 weeks in a group of healthy males and females.
2. The magnitude of variation of the enzyme activities within any individual was studied with respect to four criteria: (a) the individual's normal range, (b) the normal range calculated for each sex separately, (c) the clinically accepted normal ranges, (d) the distribution of a derived term which excluded the variation of the predominant enzyme activities between individuals, and the between-batch variation.
3. The main conclusions were: (a) Normal variation for both these enzymes is small. (b) Most of the variability is contributed by analytical variation. Within-individual variation is very small, this applying particularly to the male subjects' activity of alkaline phosphatase, and the aspartate transaminase activity of female subjects. (c) Elevation of the two enzyme activities above clinical normal ranges was infrequent, never of great magnitude, and occurred almost exclusively in males. When elevations of enzyme activity occurred, they tended to be associated either with particular males, or to occur on certain weeks. (d) When the latter effects were allowed for, and a new set of criteria calculated, the resulting ‘abnormal’ values now appeared to be more randomly distributed.
The Measurement of Bidirectional Sodium Fluxes across the Intestinal Wall in Man Using Whole Gut Perfusion
Authors: Love A. H. G. , Rohde J. E. , Abrams M. E. , Veall N. 
Published: August 2015

1. Double-tracer studies have been carried out in order to investigate the validity of a whole-gut perfusion technique for the measurement of gut lumen-to-plasma and plasma-to-gut lumen sodium fluxes in man.
2. The use of two tracers permits differentiation between the unabsorbed orally administered sodium in the stools and the sodium which has been absorbed and resecreted. The latter is by no means negligible and may amount to some 30% of the recovered material.
3. The available data do not permit the calculation of the absolute values of the bidirectional fluxes without the introduction of some assumption concerning the reabsorption of the sodium which crosses from the plasma to the gut lumen. It is assumed here that this sodium is absorbed by the gut to the same extent as the orally administered material. Analysis of the kinetics of sodium transfer from mouth to stool direct and via the blood plasma in normal subjects and patients with diarrhoea provided experimental evidence confirming the correctness of this assumption.
4. In eleven normal volunteers the gut lumen-to-plasma flow of sodium averaged 13.0 mmol min−1, implying that the observed absorption averaging 1.65 mmol min−1 represents a relatively small imbalance between the bidirectional fluxes. Although one patient with post-gastrectomy dumping syndrome had high fluxes and another with malabsorption following gut resection gave low values, it is suggested that changes in the fluxes in the same patient are more significant than isolated observations on individuals.
5. Granted the validity of the primary assumption, a considerably simpler technique may be used for clinical and field studies which is sufficiently accurate for most purposes and employs a single tracer.
Bone Metabolism and Composition in the Protein-Deprived Rat
Authors: Le Roith D. , Pimstone B. L. 
Published: August 2015

1. Bone and calcium metabolism in protein-deprived 5-week-old male rats who exhibited no biochemical or histological features of rickets were compared with age-and weight-matched control animals.
2. Intestinal calcium absorption was significantly lower in protein-deprived rats. This was associated with a smaller exchangeable calcium pool and lower bone formation as measured by calcium accretion and proline incorporation into hydroxyproline. However, calcium resorption from bone barely changed in this group and a disproportionately high fraction of the calcium pool continued to be excreted.
3. As a consequence, retarded bone growth occurred in the protein-deprived rat, leading to bones which were shorter and lighter than those of age-matched control animals, the epiphyseal regions appearing to bear the brunt of the growth retardation. This was not accompanied by a change in quality of bone, as the percentage ash content of extirpated bone remained normal.
4. Though alternative hypotheses are possible, the data are consistent with a primary disturbance of intestinal, and possibly renal tubular, calcium transport, perhaps associated with impaired synthesis of calcium-binding protein. An independent depression of collagen synthesis is likely.
Urinary Tamm—Horsfall Glycoprotein in Certain Kidney Diseases and its Content in Renal and Bladder Calculi
Authors: Grant Anne M. S. , Baker L. R. I. , Neuberger A. 
Published: August 2015

1. Tamm—Horsfall (T—H) glycoprotein has been measured by a specific radioimmunoassay method in the urine of patients with chronic renal failure, cadmium nephropathy and Lignac—Fanconi syndrome, and in renal and bladder calculi.
2. Total T—H glycoprotein excretion/24 h was markedly reduced in patients with chronic renal failure compared with normals. A highly significant correlation was observed between T—H excretion rate and creatinine clearance corrected for surface area, in both normals and patients with renal impairment. However, the mean T—H excretion per functioning nephron unit did not differ significantly in patients with renal failure compared with normals.
3. Total T—H excretion/24 h was in the normal range in patients with cadmium nephropathy despite reduced glomerular filtration rates, owing to a highly significant increase in T—H excretion per functioning nephron unit. Similar findings were obtained in a group of children with Lignac—Fanconi syndrome whose T—H excretion per functioning nephron unit was much higher than that of normal children in the same age range. This indicates an increased T—H glycoprotein excretion per functioning nephron unit in both these conditions.
4. T—H glycoprotein content of bladder and renal calculi ranged from 0002 to 5.07 mg/g of calculus. There was no correlation between T—H glycoprotein content and either the total protein content or the qualitative inorganic composition of the stones.
Two Sites of Cardiovascular Action of Angiotensin II in the Brain of the Dog
Authors: Gildenberg P. L. , Ferrario C. M. , McCubbin J. W. 
Published: August 2015

1. Infusion of angiotensin into both vertebral arteries or into a lateral cerebral ventricle of dogs anaesthetized with morphine-chloralose elicited a centrally mediated rise in blood pressure.
2. Heat coagulation of the area postrema and immediately adjacent structures abolished the pressor response to infusion of angiotensin into the circulation of the vertebral arteries, but did not alter the pressor response when the peptide was delivered into a cerebral lateral ventricle; transection of the midbrain eliminated the latter response but not the former.
3. It is concluded that there are at least two areas in the dog's brain that respond to angiotensin by inducing a raised blood pressure.
Impairment of Phenylalanine Hydroxylation in Chronic Renal Insufficiency
Authors: Young G. A. , Parsons F. M. 
Published: August 2015

1. Plasma tyrosine and phenylalanine were measured in patients with chronic renal failure and in normal subjects. Plasma tyrosine to phenylalanine ratio was greatly decreased in patients with creatinine clearance less than 16 ml/min, suggesting an impairment of phenylalanine hydroxylation. This ratio correlated with the percentage of essential to total amino nitrogen in the plasma.
2. Phenylalanine hydroxylase from rat liver was inhibited or inactivated (15%) by uraemic plasma but this could not be attributed to the individual effects of urea, creatinine, uric acid, oxalic acid, phenylpyruvic acid, glycine or phosphate. It is unlikely that the degree of inhibition was sufficient to account for the impairment of phenylalanine hydroxylation in chronic renal insufficiency.
3. Phenylalanine hydroxylase was present in rat kidney but at a very low activity relative to that present in liver; consequently, the loss of functional kidney tissue associated with chronic renal insufficiency is unlikely to impair phenylalanine hydroxylation.
4. Plasma tyrosine and liver phenylalanine hydroxylase activity were significantly decreased in partially nephrectomized rats when protein intake was inadequate.
Intestinal Absorption of Stereoisomers of Dipeptides in the Rat
Authors: Asatoor A. M. , Chadha Amrit , Milne M. D. , Prosser D. I. 
Published: August 2015

1. Studies have been made of jejunal absorption rates in vivo in the rat of the stereoisomers of alanylphenylalanine, leucyl-leucine and glycyltryptophan. Absorption rates of l-alanyl-l-phenylalanine were about 200 times those of d-alanyl-d-phenylalanine, l-leucyl-l-leucine about 24 times those of the dd-isomer, and glycyl-l-tryptophan 5 times those of glycyl-d-tryptophan. The mixed ld- and ld-isomers were absorbed at intermediate rates.
2. Absorption rates were positively correlated with the rate of hydrolysis of each dipeptide by homogenates of rat intestinal mucosa. The transport rate and rate of hydrolysis of glycyl-d-tryptophan, d-alanyl-d-phenylalanine and d-leucyl-d-leucine were significantly greater in the ileum than in the jejunum.
3. When given by stomach tube the most slowly absorbed dipeptides, d-alanyl-d- phenylalanine, d-leucyl-d-leucine and glycyl-d-tryptophan were the only ones to be excreted in significant amounts in the urine, showing that they were absorbed as the entire molecule and were resistant to hydrolysis by tissue peptidases.
4. There was a close inverse correlation between the rates of transport by rat jejunum of glycine, d-alanine, d-leucine, d-phenylalanine, d-tryptophan, d-alanyl-d- phenylalanine, d-leucyl-d-leucine and glycyl-d-tryptophan and the molecular weight of each compound, suggesting that diffusion mechanisms play an appreciable part in jejunal absorption of these compounds. No such correlation was found in the case of the ileum.
The Effect of Conjugated and Unconjugated Bile Acids on Water and Electrolyte Absorption in the Human Jejunum
Authors: Russell R. I. , Allan J. G. , Gerskowitch V. P. , Cochran K. M. 
Published: August 2015

1. The effect of conjugated and unconjugated bile acids in various concentrations on the absorption of water, sodium and chloride in the proximal jejunum in man has been studied using a perfusion system incorporating a proximal occluding balloon.
2. Unconjugated cholic acid and its glycine and taurine conjugates had no significant effect on water and electrolyte absorption. Unconjugated deoxycholic acid significantly inhibited water and electrolyte absorption at 3 mm concentration and net secretion occurred at concentrations of 5 mm, 7 mm and 10 mm. Similar results were found when taurodeoxycholic and glycodeoxycholic acid solutions were used. A greater effect was noted when higher concentrations of bile acids were used.
3. Unconjugated chenodeoxycholic acid caused net water and electrolyte secretion at 3 mm concentration and this effect became more marked with higher bile acid concentrations. Inhibition of absorption also occurred with taurochenodeoxycholic acid in a concentration of 3 mm and net secretion occurred at a concentration of 10 mm.
4. The results show that dihydroxy bile acids, conjugated or unconjugated, inhibit water and electrolyte absorption in the proximal jejunum in low concentration and cause net secretion in high concentration.
Circadian Variation in Plasma Iron Concentration and Reticuloendothelial Iron Release in the Rat
Authors: Lynch S. R. , Simon Monica , Bothwell T. H. , Charlton R. W. 
Published: August 2015

1. As in man, the plasma iron concentration in rats exhibits a circadian variation, with an early morning peak and an evening trough.
2. The release into the plasma of iron liberated from haemoglobin within the reticuloendothelial cells of the liver and spleen was studied by injecting heat-damaged erythrocytes containing 59Fe-labelled haemoglobin.
3. The percentage of 59Fe released was lower in the morning than in the evening.
4. These observations suggest that a circadian variation in reticuloendothelial cell behaviour influences the plasma iron concentration.
Some Aspects of Pulmonary Function after Rapid Saline Infusion in Healthy Subjects
Authors: Collins J. V. , Cochrane G. M. , Davis Jane , Benatar S. R. , Clark T. J. H. 
Published: August 2015

1. Rapid intravenous (i.v.) infusions of saline were administered to five healthy male volunteers. Measurements were made of static and dynamic lung volumes, ‘closing volume’ and pulmonary compliance before and after infusion; all measurements were made in the seated upright position.
2. Following a 1 litre infusion small decreases occurred in static and dynamic lung volumes in all studies and were associated in each case with an increase in ‘closing volume’. ‘Closing volume’ returned to normal within 1 h of the infusion.
3. After 2 litre infusions more marked decreases in all lung volumes occurred and were associated with variable changes in ‘closing volume’. The pattern of change varied between individual subjects and this is thought to reflect differences in localization within the lungs of the effects of the saline load in different subjects.
4. After 2 litre infusions static compliance was decreased in all subjects during the first 10–15 min. Changes in dynamic compliance showed marked individual variation.
Hepatic Synthesis of Transcobalamin II in the Rat
Authors: England J. M. , Tavill A. S. , Chanarin I. 
Published: August 2015

1. Perfusion of the isolated rat liver was accompanied by a rising level of transcobalamin II in the perfusate. There was no change in the concentration of transcobalamin I over the 5 h perfusion period.
2. When [G-14C]leucine was added to the perfusate a 14C-labelled protein appeared in the same position as transcobalamin II on column chromatography.
3. It was concluded that transcobalamin II is synthesized by rat liver.
Influence of Albumin on the Extravascular Distribution of Unconjugated Bilirubin
Authors: Bloomer J. R. , Berk P. D. , Vergalla J. , Berlin N. I. 
Published: August 2015

1. [3H]Bilirubin and 131I-labelled albumin were given simultaneously to six healthy adults by intravenous route and the amounts in the plasma were measured for several days. Multicompartmental analysis of the data showed that the rate of movement of [3H]bilirubin from the plasma into the extrahepatic extravascular space was 29·7 ± 7·3% (mean ± SEM) of the plasma pool/h, whereas the rate of movement of 131I-labelled albumin from plasma into the extravascular space was only 7·2 ± 1·0% of the plasma pool/h.
2. [14C]Bilirubin was found to equilibrate throughout the body of a child with the Crigler-Najjar syndrome within 24 h of intravenous administration, whereas 131I-labelled albumin required 4–5 days in human subjects.
3. Multicompartmental analysis of the plasma data in the six healthy adults indicated that the mass of material in the extrahepatic extravascular space relative to that in plasma was greater for unconjugated bilirubin than for albumin.
4. Studies of the tissue distribution of unconjugated bilirubin in homozygous Gunn rats demonstrated that the organs which comprise the rapidly exchanging extravascular albumin pool (liver, kidney and intestine) accumulated unconjugated bilirubin in excess of their albumin content, whereas lesser amounts of unconjugated bilirubin were accumulated in the tissues which make up the slowly exchanging extravascular albumin pool (muscle, fat and skin).
5. These findings indicate that unconjugated bilirubin moves more rapidly between plasma and extrahepatic extravascular sites than can be accounted for by transport bound to albumin. They also indicate that extravascular binding of unconjugated bilirubin includes tissue sites, as well as extravascular albumin.
Relationship between Plasma Cortisol and Peak Expiratory Flow Rate in Exercise-Induced Asthma and the Effect of Sodium Cromoglycate
Authors: Jaffe P. , König P. , Ijaduola O. , Walker S. , Godfrey S. 
Published: August 2015

1. The changes in peak expiratory flow rate (PEF) and plasma cortisol were studied in relation to a 6 min period of treadmill running in six normal and eighteen asthmatic subjects. Of the asthmatics patients, five were not receiving treatment with steroids, six were receiving low doses of steroids (under 7·5 mg of prednisone daily) and seven were receiving high doses of steroids (over 7·5 mg of prednisone daily) at the time of study.
2. All subjects were studied twice within 1 week at similar times of day, once after premedication with sodium cromoglycate (SCG) and once after a placebo.
3. Resting PEF and plasma cortisol did not differ between placebo and SCG tests.
4. No change in PEF occurred as a result of exercise in the control subjects. The asthmatic patients developed post-exercise bronchoconstriction which was partly prevented by SCG but was not affected by steroids.
5. Plasma cortisol rose after exercise in the asthmatic subjects but not in the control subjects. The rise may have been related to the stress of exercise-induced asthma. SCG had no significant effect on plasma cortisol after exercise.
Turnover of Cholesteryl Esters in Plasma Low-Density and High-Density Lipoproteins in Familial Hyperbetalipoproteinaemia
Authors: Myant N. B. , Balasubramaniam S. , Moutafis C. D. , Mancini M. , Slack Joan 
Published: August 2015

1. The turnover of cholesteryl esters in plasma high-density (HDL) and low-density (LDL) lipoproteins was measured in patients with familial hyperbetalipoproteinaemia in the homozygous and heterozygous forms and in control subjects.
2. The fractional rates of turnover of HDL and LDL cholesteryl esters were significantly lower in the patients than in the control subjects, but there was no significant difference between the absolute rates of turnover (expressed in mg h−1 kg body wt.−1) in the patients and controls.
Relationships between Ion and Water Movement in the Human Jejunum, Ileum and Colon during Perfusion with Bile Acids
Authors: Wingate D. L. , Krag E. , Mekhjian H. S. , Phillips S. F. 
Published: August 2015

1. Perfusion of the human jejunum with low concentrations of glycine-conjugated bile acids in physiological solutions induced net fluid flow that varied between absorption and secretion, with only slight variation of the luminal osmotic and ionic milieu.
2. Transmucosal net flux rates for water and the principal ions were calculated. Regression analysis of the flux data was consistent with the concept of a ‘net transported fluid’ which was iso-osmotic with respect to the lumen, with a superimposed fixed net anion exchange unaffected by the rate or direction of bulk flow.
3. Recalculation of earlier data from comparable studies of the human colon showed similar relationships consistent with varying iso-osmotic bulk flow and fixed ion exchange, the latter differing from that found in the proximal bowel.
4. Studies were performed also in the human ileum. Variable iso-osmotic bulk flow was again encountered, but ion exchange was of a lower magnitude than in the jejunum or colon. Qualitatively, ion exchange in the ileum was intermediate between the jejunum and colon.
5. These analyses suggest that transmucosal bulk flow and ion exchange may be quantitatively and spatially independent processes. They provide support for the hypothesis that bulk flow may be intercellular (and hence extracellular), while ion exchange may take place across the luminal face of the mucosal cell.
6. Secretory agents, such as the dihydroxy bile acids, provide a useful means of analysing solute-solvent flow relationships in greatly differing bulk flow conditions with relatively stable physicochemical parameters.
Plasma Porphyrin Concentrations in Porphyria Cutanea Tarda
Authors: Moore M. R. , Thompson G. G. , Allen B. R. , Hunter J. A. A. , Parker Sheena 
Published: August 2015

1. Plasma porphyrin concentrations in twelve patients with porphyria cutanea tarda (symptomatica) were compared with twenty normal controls.
2. The concentrations in porphyria cutanea tarda were significantly elevated.