bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardio-Pulmonary Responses and Gas Exchange during Exercise in Adults with Homozygous Sickle-Cell Disease (Sickle-Cell Anaemia)
Authors: Miller G. J. , Serjeant G. R. , Sivapragasam S. , Petch M. C. 
Published: August 2015

1. Cardio-pulmonary responses and gas exchange during progressive exercise, the ventilatory response to hypercapnia and anthropometric indices were measured in twenty-two Jamaican adults with homozygous sickle-cell disease. Their anthropometric indices and exercise performances were compared with those observed in healthy but sedentary adults in the Caribbean.
2. The patients had long lower limbs for their height; their body fat, proportion of lean body mass as muscle and vital capacity were reduced. Haemoglobin concentrations ranged from 4 to 10 g/100 ml. Heart rate and ventilation were normal at rest.
3. During exercise in the male patients haemoglobin concentrations below about 8 g/100 ml were associated with an increased demand for anaerobic metabolism. This resulted in excessive lacticacidaemia and increased ventilation at standard oxygen uptake (hyperpnoea). The ventilation-tidal volume relationship was normal. When allowance was made for differences in body muscle, anaemia did not appear to affect the heart-rate response to exercise.
4. Hyperventilation with respect to carbon dioxide output, increased alveolar-arterial oxygen-tension gradients and abnormal deadspace ventilation during exercise indicated a pulmonary perfusion disturbance with mixed venous shunting. The most likely basis for this disorder was considered to be the sickling phenomenon. Arterial hypoxaemia produced by the pulmonary shunt probably accounted for some of the exercise hyperpnoea, partly by increasing the chemoreceptor drive and partly by encouraging lacticacidaemia.
5. Reduced arterial carbon dioxide tensions and bicarbonate concentrations had lowered the threshold and increased the sensitivity of the ventilatory response to carbon dioxide as measured by rebreathing. Increased chemosensitivity was not thought to have contributed towards the exercise hyperpnoea since arterial carbon dioxide tensions were below the threshold value for ventilatory drive.
6. Exertional dyspnoea in sickle-cell disease was attributed to the combination of hyperpnoea and a reduced maximum breathing capacity (MBC) owing to small lung-volumes. The fraction of MBC used at standard work was therefore abnormally large, and the increased ventilatory effort produced a sensation of breathlessness in some patients.
The Effect of Cold on Blood Flow in the Hand of Patients with Raynaud's Phenomenon
Authors: Downey J. A. , Frewin D. B. 
Published: August 2015

1. The response of hand blood flow to a measured controlled cold stimulus was determined using venous occlusion plethysmography in normal subjects and patients exhibiting Raynaud's phenomenon.
2. Comparisons of percentage and absolute falls in hand blood flow, and also the recovery times after removal of the cold stimulus, were made in both the normal subjects and the patients and found to be similar.
3. The nature of the abnormality causing Raynaud's phenomenon was not elicited, but it did not appear to be due to an increased sensitivity of the hand vasculature to cold.
The Direct Interconversion of Glucose and Fructose in Human Skeletal Muscle with Special Reference to Childhood Muscular Dystrophy
Authors: Ellis D. A. , Strickland Jennifer M. , Eccleston J. F. 
Published: August 2015

1. Acid extracts of muscle-fibre preparations from human biopsies incubated with [U-14C]glucose were chromatographically analysed.
2. Radioactivity of fructose was significantly greater in muscle from childhood dystrophy patients and also in female carriers of the disease compared with normal, foetal, neurogenic muscle disease and polymyositis control groups.
3. Measurements of the activity of polyol-NADP oxidoreductase (EC 1.1.1.21) and L-iditol-NAD oxidoreductase (EC 1.1.1.14) in muscle extracts compared with the ability of extracts to dephosphorylate fructose 6-phosphate, indicated that the probable route of fructose formation from glucose is via glucitol. The mean activities of the two specified enzymes in dystrophic muscle showed 13- and 3–5-fold increases respectively compared with normal muscle, and smaller increases compared with other controls.
4. Direct comparison of labelling patterns following incubation of muscle-fibre preparations with d-[U-14C]glucose, d-[U-14C]fructose and d-[U-14C]glucitol showed that these three substances are rapidly interconvertible mutual major metabolic products, confirming the glucitol pathway as a major route of fructose formation.
5. [U-14C]fructose is readily metabolized by dystrophic muscle, excluding the possibility of its accumulation being the result of poor utilization.
6. Inhibition of polyol oxidoreductase in dystrophic muscle preparations by 3,3′-tetramethyleneglutarate drastically reduces the ability of the fibres to utilize [U-14C]-glucose, and prevents the formation of [14C]fructose.
7. Some implications of these results are discussed in relation to the pathogenesis of childhood muscular dystrophy.
Effect of Prostaglandins A1, A2, B1, E2 and F2α on Forearm Arterial Bed and Superficial Hand Veins in Man
Authors: Robinson B. F. , Collier J. G. , Karim S. M. M. , Somers K. 
Published: August 2015

1. The effects of local infusions of prostaglandins (PG) A1, A2, B1, E2 and F2α have been studied in the forearm arterial bed and superficial hand veins of man.
2. Prostaglandins A1, A2, B1, E2 and F2α all gave rise to a dose-dependent increase in forearm blood flow when infused into the brachial artery. At dosages just below the dilator range, PGF2α caused a transient fall in forearm flow, but this was not seen with any of the other prostaglandins.
3. Prostaglandins A1, A2 and E2 had no effect when infused locally into relaxed veins but caused dose-dependent dilatation when given into veins preconstricted with either noradrenaline or 5-hydroxytryptamine. Prostaglandins B1 and F2α caused dose-dependent constriction when given into relaxed veins and had no dilator effect when infused into preconstricted veins.
4. The results suggest that there are at least two types of receptors mediating responses to prostaglandins in peripheral blood vessels.
Comparison of Absorption Rates of Glucose and Maltose in Man in Vivo
Authors: Cook G. C. 
Published: August 2015

1. Using a double-lumen tube perfusion technique in vivo, the absorption rates of glucose from a glucose (200 mmol l−1) and from a maltose (100 mmol l−1) solution were measured in the proximal jejunum of six Zambian African adults.
2. In all of the subjects the rate of glucose absorption from the maltose solution was greater than that from the glucose solution. The difference between the mean rates was approximately 15% and is significant (P < 0.01).
Effects on Serum Lipids of Different Dietary Fats Associated with a High Sucrose Diet
Authors: Mann J. I. , Watermeyer G. S. , Manning E. B. , Randles J. , Truswell A. S. 
Published: August 2015

1. Each of nine volunteers was fed three different diets. The percentage of total daily energy provided by fat, carbohydrate and protein remained constant, but the nature of the fat and carbohydrate was altered. The first diet contained ordinary amounts of sucrose and predominantly saturated fat. During the second dietary period, fat remained saturated, but the quantity of sucrose was increased at the expense of complex carbohydrate. In the third dietary period, the sucrose intake remained high, but fat was supplied chiefly in the polyunsaturated form.
2. A small but statistically significant increase of serum fasting cholesterol and triglyceride was observed during the second dietary period, but on the third diet levels of both lipids fell to concentrations not significantly different from those seen on the first diet.
Plasma Dopamine β-Hydroxylase and Noradrenaline Amounts in Essential Hypertension
Authors: Geffen L. B. , Rush R. A. , Louis W. J. , Doyle A. E. 
Published: August 2015

1. Plasma dopamine β-hydroxylase (DβH) amounts were measured by radioimmunoassay in twenty-eight patients, twenty of whom had essential hypertension. There was a positive correlation between resting diastolic blood pressure and plasma DβH concentration.
2. Plasma DβH amounts also correlated significantly with those of plasma noradrenaline (NA) in individual patients.
3. These findings provide further support for the conclusions drawn from studies of plasma catecholamines that the sympathetic nervous system contributes toward the maintenance of the elevated blood pressure in essential hypertension.
Histamine Metabolism in Human Gastric Mucosa
Authors: Dencker H. , Kahlson G. , Kockum Inger , Norryd C. , Rosengren Elsa 
Published: August 2015

1. The histamine-forming capacity, i.e. histidine decarboxylase activity, was studied in the acid-secreting mucosa of the human stomach employing a highly sensitive and specific isotope-dilution method. Activity was observed in each of six specimens.
2. The enzyme, histamine methyltransferase, which methylates ring nitrogen, was also present and the product, which is inactive as a gastric acid secretogogue, was observed.
3. The products of side-chain N-methylation, N-methylhistamine and N-dimethylhistamine, both of which are highly active in promoting acid secretion, could not be detected by biological and chromatographic techniques.
Altered Bile Acid Metabolism during Treatment with Phenobarbitone
Authors: Miller N. E. , Nestel P. J. 
Published: August 2015

1. The effects of phenobarbitone on cholesterol and bile acid metabolism have been examined in healthy humans.
2. In three of four subjects the faecal excretion of bile acids was increased by phenobarbitone. This was associated with an increased pool size and turnover of cholic acid. Cholesterol excretion was not clearly affected. The fourth subject who did not respond was also exceptional in not showing an increase in the plasma clearance of antipyrine.
3. The three responsive subjects also developed significant increases in plasma cholesterol and triglyceride concentrations. These findings were associated with an early rise in very-low-density lipoprotein and a fall in plasma cholesterol specific radioactivity in one patient, changes compatible with increased cholesterol synthesis.
The Bioassay of Human Endogenous Pyrogen
Authors: Allison E. S. , Cranston W. I. , Duff G. W. , Luff R. H. , Rawlins M. D. 
Published: August 2015

1. A method is described for the quantitative assay of human endogenous pyrogen in saline and plasma which is valid in the presence of exogenous pyrogens.
2. The value of the assay is demonstrated by a study of the relation between endotoxin concentration and endogenous pyrogen production by human leucocytes in vitro.
Radioimmunoassay of Aldosterone in Plasma and Urine: Validation of a Novel Separation Technique and a Rapid Urine Assay
Authors: Jowett T. P. , Slater J. D. H. , Piyasena R. D. , Ekins R. P. 
Published: August 2015

1. A rapid, robust, accurate and sensitive radioimmunoassay procedure is described for the measurement of plasma and urinary aldosterone.
2. A new, simple method is validated for the separation of free from bound moieties which has general applicability and which involves the measurement of free steroid by direct extraction into toluene-based liquid scintillator.
3. A new method, of validated specificity, is described for the measurement of the acid-labile metabolite of aldosterone in urine which avoids the necessity for preliminary chromatographic purification.
The Organization of a Multi-Centre Randomized Control Therapeutic Trial for Mild to Moderate Hypertension
Authors: Peart W. S. 
Published: August 2015

1. The organization of a multi-centre randomized therapeutic trial for mild hypertension is described.
2. Particular attention will be paid to the effect of blood pressure lowering on susceptibility to myocardial infarction.
3. It is calculated that screening of around 180 000 subjects will be required, and that approx. 9000 men and 9000 women will eventually enter the treated group, and a similar number be randomly allocated to the control group.
4. Two separate hypotensive drugs, with different modes of action, will be employed in the treated group.
An Epidemiological Study of Hypertension
Authors: Kimura Takeshi 
Published: August 2015

1. Epidemiological studies in Iwate, Northern Japan, have confirmed a higher incidence of cerebrovascular accidents and a lower incidence of ischaemic heart diseases in Japan than in North America and Western Europe.
2. The average daily diet in Iwate is relatively low in animal proteins and fat, but relatively high in sodium.
3. Serum cholesterol is relatively low in inhabitants of Iwate.
4. The higher incidence of cerebrovascular accidents may be related to the higher sodium intake, whereas the lower incidence of ischaemic heart disease may be related to the lower intake of animal protein and fat and probably consequent lower serum cholesterol.
Sympathetic Activity and Essential Hypertension
Authors: Louis W. J. , Doyle A. E. , Anavekar S. N. , Chua K. G. 
Published: August 2015

1. In thirty-one patients with essential hypertension there was a close relationship between resting diastolic blood pressure and basal plasma noradrenaline levels (r = 0.729, P<O.001).
2. After ganglionic blockade there was a highly significant correlation between change in resting blood pressure and change in plasma noradrenaline (r = 0.813, P<0*001).
3. Patients with the highest resting blood pressure had the largest falls in blood pressure and plasma noradrenaline.
4. These results suggest that the level of the blood pressure in essential hypertension is at least in part due to excess of sympathetic activity.
Reversibility of Baroreceptor Adaptation in Chronic Hypertension
Authors: Salgado Helio Cesar , Krieger Eduardo Moacyr 
Published: August 2015

1. The pressure thresholds at which the aortic baroreceptors cease firing and attain continuous firing were determined in rats with renal hypertension of up to 2 months' duration.
2. After control recording the kidney was undipped and, if necessary, the rats were bled to restore normal pressure. After 1 and 6 h the baroreceptors were again studied.
3. It was found that the entire baroreceptor pressure range shifted progressively downward to normal levels after the normalization of pressure.
The Value of Portably Recorded Blood Pressures in the Initiation of Treatment of Moderate Hypertension
Authors: Sokolow Maurice , Perloff Dorothee , Cowan Ronald 
Published: August 2015

1. The value of making portable-recorder measurements of blood pressure has been studied.
2. The danger associated with mild arterial pressure elevation is not immediate, but almost any reduction in pressure is likely to reduce risk.
3. Patient and doctor together must decide what burden of side effects of hypotensive therapy is tolerable.
4. Such decisions will become rational only when the probability of vascular involvement can be accurately assessed in a given patient.
5. The likelihood of arresting the disease through antihypertensive therapy must similarly be assessed.
The Vicious Circle in Acute Malignant Hypertension of Rats
Authors: Dauda G. , Möhring J. , Hofbauer K. G. , Homsy E. , Miksche Ulrike , Orth H. , Gross F. 
Published: August 2015

1. In renal hypertensive rats, increase in blood pressure above 180 mmHg may induce sodium and water loss, reduced growth rate, elevated haematocrit, a marked rise in plasma renin concentration, an increase in renin extractable from the clamped and the contralateral kidney and malignant nephrosclerosis of the contralateral kidney. These symptoms characterize the malignant phase of renal hypertension in rats.
2. When water was given as drinking fluid, ten of eighteen rats developed signs of malignant hypertension and malignant nephrosclerosis within 3–4 weeks. Administration of 0.9% saline instead of water induced higher blood-pressure levels, but only five of eighteen rats showed malignant nephrosclerosis. When drinking fluid was changed from water to saline shortly before or shortly after the onset of malignant hypertension, the condition improved, and in only one of twelve rats was malignant nephrosclerosis observed.
3. It is concluded that in renal hypertensive rats sodium supplements may improve or prevent signs of malignant hypertension and the development of malignant nephrosclerosis.
Ionic Composition of Arterial Wall in Experimental Hypertension
Authors: Rorive G. L. F. J. , Van Cauwenberge H. 
Published: August 2015

1. To obtain additional information on the role of the ionic composition of the vascular wall in the pathogenesis of arterial hypertension, we studied the distribution of ions in aorta and tail arteries of rats with experimental renal hypertension.
2. The water content of rat aorta is markedly increased in hypertensive animals [1992 ml/kg-dry weight (DW) compared with 1688 ml/kg DW].
3. Na, K, Ca, Mg and to a less extent Cl content is increased in both aorta and tail arteries.
4. These modifications are not affected by incubation in vitro.
5. Compartmental analysis as well as pharmacological studies suggest that part of the water increase and most of the potassium excess are related to a hypertrophy of smooth-muscle cells in hypertensive arteries.
6. The sodium excess in the vessels of hypertensive rats is bound in the extracellular space on anionic sites.
7. From these observations, it seems unlikely that the ionic modification described could affect the membrane potential of smooth-muscle cells, since the ratio between extra- and intra-cellular concentration is not markedly affected.
8. The bound sodium could affect the viscoelastic properties of the arteries of hypertensive animals. Cell hypertrophy by itself could explain at least partly the modification of the ionic composition and the increased reactivity of hypertensive vessels.
Effects of Angiotensin on Plasma Electrolyte Concentrations in Rabbits and in Man
Authors: Healy J. K. , Elliott A. J. , Harrison L. C. 
Published: August 2015

1. The effects of an intravenous infusion of angiotensin on plasma electrolytes were examined in normal, adrenalectomized and nephrectomized groups of rabbits and in normal man. Rabbits were given 1 μg kg−1 min−1 and human subjects 0.008–0.030 μg kg−1 min−1 of angiotensin.
2. In normal rabbits, angiotensin increased arterial and venous plasma K within 2 min by 0.8 and 0.4 mmol l−1 respectively, some hyperkalaemia persisting for 30–60 min. After 60 min arterial plasma Na decreased by 3.8 mmol l−1 and Cl by 2.4 mmol l−1. Arterial blood pH increased 0.04 units after 15 min, and arterial plasma Mg and Ca rose slightly after 2 min. Pressor response was 20–28 mmHg.
3. In adrenalectomized and nephrectomized rabbits, arterial plasma K rose within 2 min by 2.6 and 3.8 mmol l−1 respectively. Arterial plasma Na fell after 60 min in both groups, and also after 2 min in nephrectomized animals. Venous plasma K and Na showed similar although less marked changes. Changes in plasma Mg, Ca and blood pH were not significant. Pressor response in both groups exceeded that in normal rabbits.
4. In man, a sustained rise of 0.2–0.3 mmol 1-1 occurred in arterial plasma K during angiotensin infusion. Arterial blood pH rose 0.01 units after 15 min. Pressor response was 12–15 mmHg.
5. It was concluded that plasma electrolyte levels may change during angiotensin administration in rabbits and man, and that these changes may influence interpretation of physiological actions of angiotensin.
Plasma Oxalate Concentration and Renal Excretion of Oxalate in Man
Authors: Hodgkinson A. , Wilkinson R. 
Published: August 2015

1. The concentration of oxalate in plasma was determined by an isotopic method involving the simultaneous measurement of [14C]oxalate activities in plasma and urine and the concentration of stable oxalate in the urine.
2. Plasma oxalate concentrations ranged from 1.3 to 1.6 μmol/l (11.8–14.3 μg/100 ml) in three normal men; in fifteen male patients with renal calcium oxalate stones the mean value was 1.73 μmol/l (15.6 μg/100 ml), SD = 0.55 μmol/l (4.98 μg/100 ml).
3. The renal clearance of [14C]oxalate ranged from 162 to 358 ml/min (mean = 249 ml/min) in the normal subjects and from 95 to 315 ml/min (mean = 201 ml/min) in the patients. A direct and statistically significant relationship was observed between the oxalate and creatinine clearances.
4. The oxalate/creatinine clearance ratio ranged from 1.42 to 2.60 (mean = 1.95) in the normal subjects and from 1.04 to 2.33 (mean = 1.76) in the patients, implying a net renal tubular secretion of oxalate. However, oxalate excretion was unaffected by probenecid, a drug known to inhibit the active tubular transport of organic anions.
5. Possible errors in the determination of plasma oxalate concentration and oxalate clearance by chemical and isotopic methods are discussed.
6. Intravenous administration of [14C]oxalate to eight subjects allowed estimations of the miscible oxalate pool [mean = 53.3 μmol (4.80 mg); SD = 18.7 μmol (1.68 mg)], the volume of distribution of [14C]oxalate (mean = 45.2% of body weight; SD = 5.65) and the biological half-life of [14C]oxalate (mean = 91.10 min; SD = 13.89).
An Increasing Work RATE Test for Assessing the Physiological Strain of Submaximal Exercise
Authors: Spiro S. G. , Juniper E. , Bowman P. , Edwards R. H. T. 
Published: August 2015

1. A progressive exercise test was performed on forty-four male and twenty-nine female healthy Europeans, aged between 20 and 64 years. Values for cardiac frequency (fH) and ventilation (V̇) were interpolated to standard (submaximal) oxygen uptakes (V̇o2) of 0·751/min and 1·01/min. The tidal volume (Vt) at a ventilation of 20 and 301 BTPS/min was also determined (Vt 20 and Vt 30 respectively).
2. The slope of the linear relationship between cardiac frequency or ventilation and oxygen uptake (SfH and SV̇ respectively) can be used as a measure of the fitness of an individual, as it indicates the increase in fH or V̇ that is obligatory for an increase in energy expenditure equivalent to an additional oxygen uptake of 1·0 1/min (about the increase necessary for walking on the level at a normal speed). By analogy with the responses of an athlete, a ‘fit’ subject is one in whom responses are economically low, i.e. SfH and SV̇ are lower than in sedentary individuals. Measures of SfH and SV̇ can also be used to indicate the demands of everyday activities on fH and V̇.
3. When SfH and SV̇ are related to the individual's capacity to adapt fH and V̇ from resting to predicted maximum values (‘adaptation capacity’ ACfH and ACV̇ respectively), the resulting index (SfH × 100/ACfH or SV̇ × 100/ACV̇) expresses the percentage of the adaptation capacity used for an additional energy expenditure equivalent to a V̇o2 of 1·01/min, and can be considered a measure of the ‘physiological strain’ of exercise. The effects on exercise responses of differences in body muscle can be allowed for by multiplying this index by lean body mass (LBM). The lower the (size-adjusted) physiological strain index, the fitter the individual subject.