bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Normal Alveolar-Arterial Oxygen-Tension Gradient in Man
Authors: Harris E. A. , Kenyon Alison M. , Nisbet Heather D. , Seelye Eve R. , Whitlock R. M. L. 
Published: August 2015

1. The alveolar-arterial oxygen-tension gradient was measured in duplicate, in forty-eight healthy subjects (twenty-four men and twenty-four women) aged from 20 to 74 years, while breathing oxygen concentrations of approximately 14, 21, 40, 60 and 100%.
2. The gradient increased with age and with inspired O2 concentration up to 60%. Above 60%, during normal breathing, there was no significant change in gradient.
3. Breathing 100% O2 in deep breaths decreased the gradient in all age-groups, significantly so in subjects of 50 years and younger. The remaining gradient was due to anatomical venous shunt.
4. When this anatomical shunt was allowed for, the differences in gradient between age-groups were largely abolished at all inspired O2 concentrations. The gradient which was not due to anatomical shunt, when breathing air, remained higher in subjects over 60 years than in the younger subjects.
5. The results can be interpreted to mean that three components contribute to the normal gradient: (a) irreversible anatomical shunt; (b) closed, unventilated alveoli which can only be inflated by deep breaths; and (c) cyclical airway closure during normal breathing in subjects over 60 years. Diffusion disequilibrium may contribute a gradient of up to 3 mmHg during the breathing of low O2 concentrations.
Plasma Enzyme and Isoenzyme Changes during Perfusion of the Isolated Pig Liver
Authors: Buttery J. E. , Parbhoo S. P. , Baron D. N. 
Published: August 2015

1. Changes in the perfusate activities of aspartate transaminase, lactate dehydrogenase, its ‘LD-5’ component, sorbitol dehydrogenase, ornithine carbamoyltransferase, and the isoenzyme patterns of lactate dehydrogenase and aspartate transaminase, were investigated in eleven perfusions of pig liver with human blood in order to assess liver cell damage during perfusion.
2. The aspartate transaminase values were a sensitive indicator of liver damage provided that, as was usually the case, the degree of haemolysis was small. Appearance on electrophoresis of the mitochondrial isoenzyme of aspartate transaminase indicated severe liver damage.
3. Measurement of sorbitol dehydrogenase activity was also shown to be a sensitive index of liver cell damage, and had the advantage that haemolysis did not interfere.
4. Measurement of total lactate dehydrogenase activity was unreliable as this largely reflected the degree of haemolysis rather than liver cell damage. However, the isoenzyme pattern of lactate dehydrogenase on electrophoresis distinguished liver cell damage from haemolysis. The chemical determination of ‘LD-5’ was not a sensitive index of pig liver damage as this fraction is found only in low concentration in pig liver.
5. Ornithine carbamoyltransferase was also found not to be a sensitive marker of liver cell damage.
Human Placental Transfer of Glucagon
Authors: Moore W. M. O. , Ward B. S. , Gordon C. 
Published: August 2015

1. The permeability of human chorion laeve in vitro to 125I-labelled glucagon was investigated. The problem caused by degradation of 125I-labelled glucagon in the preparation and a means to prevent this are described.
2. The human chorion laeve was found to be impermeable to iodinated glucagon.
Tissue Distribution of Coenzyme and other Forms of Vitamin B12 in Control Subjects and Patients with Pernicious Anaemia
Authors: Linnell J. C. , Hoffbrand A. V. , Hussein H. A-A. , Wise Irene J. , Matthews D. M. 
Published: August 2015

1. Methylcobalamin (Me-B12), adenosylcobalamin (Ado-B12), hydroxocobalamin (OH-B12) and cyanocobalamin (CN-B12) have been estimated by a chromatographic—bioautographic technique in plasma, erythrocytes, leucocytes and bone marrow from normal subjects, hospital controls and patients with untreated pernicious anaemia.
2. Estimates of concentrations of cobalamins have also been obtained in bile, cerebrospinal fluid, liver biopsies and in autopsy samples of liver, kidney, spleen, brain and pituitary.
3. In normal and control subjects, Ado-B12 predominated in all samples except plasma, in which Me-B12 was the predominant form. Me-B12, Ado-B12, OH-B12 and CN-B12 were found in normal erythrocytes, leucocytes and bone marrow and the proportion of each cobalamin was fairly similar in all these tissues. In liver, kidney, spleen, brain and pituitary, the proportions of the cobalamins were more variable. No CN-B12 was detected in these organs.
4. In untreated pernicious anaemia, Me-B12 was disproportionately reduced in plasma, but not in erythrocytes, leucocytes or bone marrow. There was a small increase in the proportion of CN-B12 in plasma, blood cells and bone marrow in untreated pernicious anaemia.
Metabolism of the Third Component of Complement (C3) in Normal Human Subjects
Authors: Charlesworth J. A. , Williams D. Gwyn , Sherington E. , Peters D. K. 
Published: August 2015

1. A single, biologically active, highly purified preparation of the third component of complement (C3) has been used to study C3 metabolism in eleven normal subjects.
2. Half-life of the radioactive protein ranged from 64 to 81 h with fractional catabolic rates (FCR) of 1·36–1·95% of the plasma pool/h. Extravascular/intravascular pool ratios were 0·19–0·55.
3. Analysis of plasma and extravascular radioactivity curves suggested that the primary site of C3 metabolism was intravascular.
Interstitial Gel Swelling Pressure in Human Subcutaneous Tissue Measured with a Cotton Wick
Authors: Snashall P. D. , Boother Frances A. 
Published: August 2015

1. A cotton wick probe has been used to measure the pressure in subcutaneous interstitial tissues of man.
2. The probe was inserted with minimal trauma into a plane of natural dissection at the level of the deep fascia in three sites: dorsum of the hand and foot, and the forearm.
3. The pressure was subatmospheric on every occasion (mean pressure: hand, −3·01 ± SD 0·50 cmH2O; foot, −3·54 ± SD 1·74 cmH2O; forearm, −2·41 ± SD 0·85 cmH2O).
4. Taking the three sites together, there was a positive correlation between wick pressure and locally measured tissue temperature (r = 0·55; P < 0·01), but when each site was analysed separately the relationship was significant only in the hand.
5. Wick pressure rose when the subcutaneous tissues were warmed.
6. A negative correlation was observed between wick pressure from the forearm and the subject's plasma colloid osmotic pressure (r = 0·73; P < 0·01), but no such relationship was observed in the hand or foot.
Maximal Expiratory Flow and Lung Volume Changes Associated with Exercise-Induced Asthma in Children and the Effect of Breathing a Low-Density Gas Mixture
Authors: Benatar S. R. , König P. 
Published: August 2015

1. Lung volumes and maximum expiratory flow volume (MEFV) curves were measured before and after exercise and after a bronchodilator in eight asthmatic children.
2. Exercise produced significant changes in all volumes and flow rates measured, but the most sensitive measurement was of flow rate at an absolute volume in the terminal portion of the forced vital capacity. Of the more simply obtained measurements maximal flow at 50% of the exhaled vital capacity was the most sensitive, but reductions in forced expiratory volume at 1 s and peak flow rate were almost as marked.
3. The marked reductions in flow rates at low lung volumes after exercise were accompanied by large increases in residual volume and a reduction in the slope of the MEFV curve. These changes suggest functional closure of some lung units and an increase in the time-constant of emptying of other units.
4. The response of flow to breathing helium—oxygen (79:21, v/v) was assessed in the dilated state (before exercise or after bronchodilator) and the constricted state (after exercise) in five of the subjects.
5. An increase in density-dependence of flow rates at all lung volumes during constriction is evidence that, despite the reduction in flow rates, convective acceleration and turbulent flow constitute a greater proportion of the total upstream resistance after exercise than before exercise. The implication is that the cross-sectional area at equal pressure points (EPP) is smaller after exercise than before exercise. This could result from either bronchoconstriction with no change in the location of EPP, or from progression of the EPP further upstream to a region where loss of airways or reduction in their diameter has rendered the total cross-sectional area considerably smaller than under normal circumstances.
The Reflex Hypoxic Respiratory Drive in Patients with Chronic Bronchitis
Authors: Lee K. D. , Bishop J. M. 
Published: August 2015

1. The extent of the reflex hypoxic respiratory drive was investigated in a group of patients who were hypoxaemic because of chronic bronchitis.
2. Oxygen was substituted for the inspired air for periods of 1–2 min. This produced a rise in arterial Po2 (Pa,o2) which varied considerably from patient to patient, but in each case the rate of rise was effectively linear with time. The resulting fall in ventilation, measured over 15 s periods, was compared with the Pa,o2 achieved.
3. In most patients the Pa,o2 did not reach hyperoxic levels. The total contribution of their peripheral chemoreceptor reflexes to their resting ventilation could not therefore be measured. The fraction of the ventilation abolished when the Pa,o2 was corrected to near-normal levels was measured instead. In two patients whose Pa,o2 on air was 6·0 and 6·5 kPa (45 and 49 torr) this fraction was 25 and 27%. In three patients whose initial Pa,o2 was 8·0–8·8 kPa (60–66 torr), it was 18–21%. In three patients with an initial Pa,o2 of more than 9·3 kPa (70 torr), it was 5–16%.
4. Each of these patients therefore had a reflex hypoxic respiratory drive. In the more severely hypoxaemic patients the fraction measured was an important part of the overall efferent drive to the respiratory muscles.
The Effect of Aldosterone on Colonic Potential Difference and Renal Electrolyte Excretion in Normal Man
Authors: Efstratopoulos A. D. , Peart W. S. , Wilson G. A. 
Published: August 2015

1. The effect of the intravenous administration of aldosterone on the colonic potential difference has been studied in eight normal young males and compared with effects on renal function.
2. Under control conditions the colonic potential was remarkably stable over a period of 10 h of recumbency whereas with infusions of aldosterone ranging from 5·6 to 89·6 pmol min−1 kg−1 (2 to 32 ng min−1 kg−1), the colonic potential difference increased in a quantitatively reproducible fashion. The correlation between change in plasma aldosterone and in colonic potential was highly significant.
3. The delay between the end of the infusion and the maximum change in colonic potential was 4 h. The shortest latent period before any change in colonic potential occurred was 70 min after the start at infusion rates of 11·2 pmol min−1 kg−1 or more. The effect, although still present at 10 h, had returned to control values at 20 h after the start.
4. The main renal effect of aldosterone was on sodium excretion, which was reduced at infusion rates of 11·2 pmol min−1 kg−1 and more, but the relation to dose of aldosterone was not very quantitative and the effect was more like a threshold response.
5. The conclusion is that the colonic potential difference may be used as a quantitative indicator of the actions of aldosterone and is more sensitive and dose-dependent than the renal effects.
Influence of Salmon Calcitonin on Radio-Phosphorus Distribution in Polycythaemic Patients
Authors: Paillard Françoise , Ardaillou R. , Vallée G. 
Published: August 2015

1. Salmon calcitonin injected 5 min after a therapeutic dose of 32P in polycythaemic patients produced a significant increase in rate of disappearance of 32P from plasma when compared with a control group.
2. Salmon calcitonin injected 120 min after 32P injection did not modify the curve of 32P disappearance from plasma.
3. Salmon calcitonin injected 10 days after 32P injection did not produce any change in 32P plasma radioactivity or specific radioactivity.
RÉSUMÉ
1. La calcitonine de saumon (sCT) injectée 5 min après une dose thérapeutique de 32P chez des malades polyglobuliques produit une disparition du 32P du plasma plus rapide que dans un groupe témoin.
2. La sCT injectée 120 min après le 32P ne modifie pas la courbe de disparition du 32P du plasma.
3. La sCT injectée 10 jours après le 32P ne produit aucun changement dans la radioactivité (RA) ou l'activité spécifique (SA) du 32P du plasma.
Evidence for Active Transport of the Dipeptide Carnosine (β-Alanyl-l-Histidine) by Hamster Jejunum in Vitro
Authors: Matthews D. M. , Addison Jill M. , Burston D. 
Published: August 2015

1. The characteristics of intestinal transport and hydrolysis of carnosine (β-alanyl-l-histidine) have been studied in rings of everted hamster jejunum in vitro.
2. During incubation with carnosine, large amounts of intact peptide appeared in the intestinal wall, accompanied by small amounts of the constituent amino acids in the free form. Although there was some extracellular hydrolysis, the free amino acids appearing in the intestinal wall were almost entirely derived from intracellular hydrolysis of the peptide. Incubation in l-alanyl-l-histidine resulted in uptake of the constituent amino acids in the free form without appearance of intact peptide in the intestinal wall.
3. Total uptake of β-alanine (both peptide-bound and free) and total uptake of histidine were greater from a low concentration (1 μmol/ml) of carnosine than uptake of these amino acids from the equivalent amino acid mixture. At a high concentration of carnosine (20 μmol/ml), total uptake of β-alanine was greater from the peptide than from the equivalent amino acid mixture but total uptake of histidine was less. At this concentration, total uptake of β-alanine plus total uptake of histidine from the peptide was approximately the same as from the amino acid mixture.
4. Uptake of carnosine by jejunal rings was the result of a saturable process (Kt 9·4 μmol/ml, Vmax. 2·7 μmol g−1 initial wet wt. min−1). Intact carnosine was concentrated in the intestinal wall, the concentration ratio between intracellular fluid and incubation medium being up to 3·4/1. Uptake of carnosine was reduced by anoxia, metabolic inhibitors and replacement of medium Na+. Na+-dependent active transport was shown to be involved in uptake of carnosine by hamster jejunum in vitro.
Studies of the Metabolism of Asialotransferrins: Evidence that Transferrin Does not Undergo Desialylation in Vivo
Authors: Wong K.-L. , Charlwood P. A. , Hatton M. W. C. , Regoeczi E. 
Published: August 2015

1. Experiments are reported which aimed at determining whether transferrin loses sialyl residues from the carbohydrate side-chains during the biological lifetime of the molecule. To explore this possibility, transferrin fractions of relatively high sialic acid content (referred to as sialotransferrin) were prepared from purified rabbit and bovine transferrin by preparative polyacrylamide-gel electrophoresis. After labelling with 125I, the preparations were injected into a group of three rabbits each. From the plasma samples obtained between 1 h and 6–8 days after injection, transferrin was partially purified, mixed with 131I-labelled asialotransferrin of the corresponding species and run in preparative polyacrylamide-gel electrophoresis. In each specimen examined, the 125I radioactivity migrated ahead of the marker asialotransferrin, and no portion of the dose was detected with the electrophoretic mobility of asialotransferrin.
2. Evidence is presented that bovine transferrin desialylated in vitro remains detectable in the plasma of rabbits for intervals which are comparable with those found in previous studies with rabbit asialotransferrin.
3. A mathematical model is described for the computation of asialo- to sialotransferrin radioactivity ratios in the plasma, continuous desialylation of pulse-injected sialotransferrin being assumed. Calculations were made at various hypothetical rates of desialylation.
4. On the basis of the experimental data and the model it is concluded that transferrin (both rabbit and bovine) is not subjected to systematic desialylation in rabbits. Random desialylation of some transferrin could take place at rates less than 5% of the fractional catabolic rate of transferrin, which would be without any biological significance.
Changes in Body Fluid Distribution and Interstitial Tissue Compliance during the Development and Reversal of Experimental Renal Hypertension in the Rat
Authors: Lucas J. , Floyer M. A. 
Published: August 2015

1. To determine the part played by changes in interstitial tissue compliance in the mechanism of experimental renal hypertension, pressure and volume measurements were made in rats 60 days after partial constriction of one renal artery with a clip and removal of the opposite kidney. Tissue pressure and venous pressure were found to be significantly higher in rats which developed systolic arterial blood pressure of 140 mmHg or above than in loosely clipped controls with normal blood pressure. Plasma volume (PV) was also increased in the hypertensive animals, but there was no difference in interstitial fluid volume (IFV); the PV/IFV ratio was significantly higher in the hypertensive rats.
2. Removal of the clip in the hypertensive rats restored blood pressure to normal in 1 h; this was associated with a fall in venous pressure and plasma volume. Tissue pressure fell despite a rise in interstitial fluid volume; the PV/IFV ratio fell.
3. It is suggested that renal artery constriction, possibly by a humoral mechanism, causes a fall in interstitial space compliance and that this, by causing changes in body fluid distribution, plays a part in the mechanism of experimental renal hypertension. This mechanism may have a physiological role in the maintenance of adequate plasma volume during water shortage.
The Single-Passage Extraction of 18F in Rabbit Bone
Authors: Wootton R. 
Published: August 2015

1. The uptake of an intra-arterial injection of 18F was compared with the uptake of a simultaneous injection of 51Cr-labelled microparticles in rabbit bone.
2. The mean single-passage extraction ratio of 18F was 102% (sem 11%, n = 9) in the femur and 119% (sem 9%, n = 10) in the tibia.
3. A mean of 41% (sem 3%, n = 9) of the afferent blood to the femur and 28% (sem 4%, n = 10) to the tibia was found to flow to the marrow.
4. All the efferent blood from the marrow was cleared of 18F by bone.
5. It is concluded that 18F is suitable as a tracer for the measurement of bone blood flow in man and as a reference tracer for measuring the extraction ratios of other bone-seeking radiopharmaceuticals.
Adrenocortical Function in Obesity and Cushing's Syndrome
Authors: Hankin Margaret E. , Theile Helen M. , Steinbeck A. W. 
Published: August 2015

1. The 24 h urinary excretions of Porter—Silber (P—S) chromogens, 17-hydroxycorticosteroids (17-OHCS) and free cortisol, and day-night variation of plasma P—S chromogens, were studied in normal and obese women and patients with a confirmed diagnosis of Cushing's syndrome.
2. The mean absolute values of P—S chromogens, 17-OHCS and free cortisol were similar for the normal and obese subjects and elevated in Cushing's syndrome. With the exception of the 17-OHCS there was some overlapping of the individual values within the three groups. All the subjects with Cushing's syndrome and several of the obese subjects had values of 17-OHCS which were outside the normal range.
3. The 24 h urinary 17-OHCS and free cortisol excretion expressed per kg body weight were significantly lower for the obese than for the control subjects and subjects with Cushing's syndrome. The values were significantly higher for the subjects with Cushing's syndrome than for the obese and normal subjects. There was some overlapping of the individual values.
4. Two normal and two obese subjects failed to show significant day-night variation, whereas only four of the patients with Cushing's syndrome had significant day-night variation of plasma P—S chromogens.
5. The urinary 17-OHCS for four of the obese subjects with some symptoms of adrenocortical hyperactivity were suppressed normally on a low dose of dexamethasone whereas those with Cushing's syndrome failed to do so.
Lung Function in Chronic Uraemia before and after Removal of Excess of Fluid by Haemodialysis
Authors: Stănescu D. C. , Veriter C. , De Plaen J. F. , Frans A. , De Strihou C. Van Ypersele , Brasseur L. 
Published: August 2015

1. Measurements of lung volumes, airway resistance, maximal expiratory flow rates and closing volume were made in twelve patients with chronic renal insufficiency and fluid overload, before and after haemodialysis.
2. Before dialysis, these measurements were within normal limits, except for peak expiratory flow rate, which was significantly lower, and closing volume, which was significantly higher than predicted values.
3. After dialysis body weight decreased significantly and the removal of excess of fluid was accompanied by a significant decrease of closing volume.
4. Measurements of closing volume and the other pulmonary tests were made in six healthy subjects, the same timing being observed as in the patients. Mean as well as individual values of closing volume did not alter, thus excluding the possibility that the changes observed in the patients were due to a circadian rhythm.
5. It is suggested that the higher than predicted closing volume was due to the accumulation of fluid in the dependent areas of the lung, promoting a premature airway closure. Removal of excess of fluid allowed airways to close at a lower lung volume.
The Redistribution of Body Sodium in Women on Long-Term Oestrogen Therapy
Authors: Aitken J. M. , Lindsay R. , Hart D. M. 
Published: August 2015

1. The effects on the serum electrolytes of long-term treatment with either mestranol or a placebo were determined in 175 healthy middle-aged oophorectomized women. In forty of these women the packed cell volume (PCV), serum albumin, serum and urinary osmolality, inulin space and total exchangeable sodium (Nae) were also measured.
2. The mean serum sodium and chloride concentrations were significantly lower in the mestranol-treated women, and this was associated with a significant reduction in the mean PCV and the mean serum albumin concentration by comparison with the placebo-treated group.
3. The mean urinary osmolality was higher and the mean serum osmolality lower in the mestranol group such that there was a significant increase in the mean urine/serum osmolality ratio as compared with the placebo group.
4. The mean inulin space was significantly higher in the mestranol group as compared with the controls, but there was no significant difference in Nae.
5. These findings support the hypothesis that oestrogen-induced fluid retention is the result of primary water retention with secondary redistribution of body sodium.
The Ventilatory Response to Carbon Dioxide in Patients Who Have Recovered from Cardiogenic Pulmonary Oedema
Authors: Spierer M. 
Published: August 2015

1. The arterial partial pressure of carbon dioxide in a group of patients with acute cardiogenic pulmonary oedema was compared with their ventilatory response to carbon dioxide after recovery from the acute episode of pulmonary oedema.
2. There was no significant correlation between the degree of carbon dioxide retention during acute pulmonary oedema and the ventilatory response to carbon dioxide after recovery.