bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of the Contractility, Biochemistry and Morphology of an Isolated Preparation of Human Skeletal Muscle
Authors: Moulds R. F. W. , Young A. , Jones D. A. , Edwards R. H. T. 
Published: August 2015

1. A new method of studying isolated human skeletal muscle has been evaluated. This involves the incubation and electrical stimulation of strips of muscle, obtained at surgical biopsy, that are tied at the cut ends of the fibre bundles.
2. Morphological examination showed that the fibres were sealed off at the cut ends. Damage appeared to be restricted to the areas immediately adjacent to the ties.
3. Contractile properties were well maintained for several hours and measurements of tissue metabolites showed that muscle contents of the high-energy phosphate compounds were well preserved.
4. The isolated preparations were found to have the same contractile properties as human quadriceps femoris studied in vivo by the methods described in the preceding paper.
5. Correlation was found between the relaxation speed of the isolated preparations and their fibre-type composition histochemically determined.
6. It is concluded that this technique is a valid addition to the present methods of studying the physiology and pharmacology of human skeletal muscle.
Muscle-Protein Catabolism after Injury in Man, as Measured by Urinary Excretion of 3-Methylhistidine
Authors: Williamson D. H. , Farrell Rose , Kerr Alison , Smith R. 
Published: August 2015

1. Urinary excretion of 3-methylhistidine, an index of the rate of muscle breakdown, has been measured during the first 7 days in patients after elective surgery or accidental injury.
2. There was no major difference between the mean daily excretion after skin grafting or total hip replacement, or in injured patients who were hyperketonaemic for the first 24 h after admission.
3. The group of injured patients who did not develop hyperketonaemia had a mean urinary 3-methylhistidine excretion which was twice that of the other groups.
4. It is concluded that increased breakdown of muscle protein makes a major contribution to the greater urinary nitrogen excretion in the normoketonaemic group of injured patients.
Effects of Clonidine on Biochemical Indices of Sympathetic Function and Plasma Renin Activity in Normotensive Man
Authors: Wing L. M. H. , Reid J. L. , Hamilton C. A. , Sever P. , Davies D. S. , Dollery C. T. 
Published: August 2015

1. A single oral dose of clonidine hydrochloride (300 μg) lowered systolic blood pressure by 20 ± 2 mmHg and diastolic blood pressure by 15 ± 2 mmHg in seven healthy normotensive subjects.
2. Resting supine plasma noradrenaline concentration fell from 2·42 ± 0·47 nmol/l before dosing to a minimum of 0·59 ± 0·18 nmol/l at 6 h. The value subsequently rose and was not significantly different from that before the dose at 12 h. There was a significant reduction in urinary free catecholamine excretion in the first 12 h after dosing.
3. Resting supine plasma renin activity before dosing was 0·95 ± 0·16 pmol of angiotensin I h−1 ml−1 of plasma and rose significantly after clonidine to 3·50 ± 0·39 pmol of angiotensin I h−1 ml−1 of plasma at 6 h. By 12 h plasma renin activity had returned to control values.
4. When the same subjects were studied on a control, drug-free, day under the same conditions, there was no significant change in blood pressure or plasma noradrenaline. Although plasma renin activity rose during this control day, it was significantly lower than after clonidine.
5. In normotensive subjects single doses of clonidine lower blood pressure and are associated with a reduction of sympathetic nervous activity. Delayed elevation of plasma renin activity may be secondary to the fall in blood pressure. There is no evidence for an overshoot of sympathetic activity after a single dose of clonidine.
A Slow Component of Iodine Turnover in Athyreotic Individuals
Authors: Smith T. , Edmonds C. J. 
Published: August 2015

1. Whole-body retention and plasma values of 131I after a test dose were measured for up to 32 days in patients previously rendered athyreotic by surgery and 131I treatment for thyroid carcinoma, and who were without detectable functioning tissue at the time of study.
2. About 99·8% of the administered 131I was rapidly excreted, consistent with renal iodide excretion. The remainder (about 0·2%) was eliminated slowly, with mean half-life 15 days; we call this the slow-turnover component.
3. By the sixth day after the 131I dose, very little [131I]iodide remained in the plasma. The average protein-bound 131I was only 0·0035% of dose/l, with mean half-life 14·1 days; 90% was non-extractable in butanol. Labelled albumin accounted for about 80% of the non-extractable fraction.
4. The distribution space estimated from the slow-turnover component and protein-bound 131I was 34 1, indicating that most of the slow-turnover component is extravascular.
5. Stable potassium iodide administration, starting 2 days after giving 131I, had no observable effect on the variables measured.
6. Impairment of renal function delayed [131I]iodide excretion and increased both slow-turnover component and plasma protein-bound 131I.
7. A simple model describing iodine kinetics in athyreotic individuals is suggested. It predicts that the slow-turnover component contains only about 4 μg of iodine and, since this is distributed widely in body tissues, it is unlikely to be of biological significance.
The Crystalline Salts of Calcium Bilirubinate in Human Gallstones
Authors: Sutor D. June , Wilkie Lynette I. 
Published: August 2015

1. The acid, neutral and ‘intermediate’ salts of calcium bilirubinate have been synthesized.
2. All are crystalline, and the intermediate salt which has 1½ molecules of bilirubin per calcium atom probably has a crystal structure containing molecules of both acid and neutral salts.
3. The acid or intermediate salts have been found in 14 out of 70 gallstones analysed recently by X-ray diffraction.
Muscle Metabolism during Exercise in Hemiparetic Patients
Authors: Landin S. , Hagenfeldt L. , Saltin B. , Wahren J. 
Published: August 2015

1. A group of eight male patients with moderate hemiparesis was studied at rest and during 40 min of exercise on four occasions. Both two-leg and one-leg exercise were performed and each leg was studied separately. Arterial concentrations and leg exchange of carbohydrate substrates and free fatty acids were examined. In addition, the concentrations of intramuscular metabolites for each leg were measured at rest and immediately after exercise.
2. In two-leg exercise, oxygen uptake for the paretic leg was significantly lower than for the non-paretic leg at rest (55%) as well as during exercise (40%). Glucose uptake by the paretic leg was smaller (25–50%) and there was no measurable net leg exchange for lactate. Recordings of pedal pressure indicated that the paretic leg did considerably less work than the non-paretic leg throughout the exercise period. The rate of uptake of oleic acid was lower for the paretic leg (50%) in the resting state but similar for the two legs during exercise. The recovery of 14CO2 from [14C]oleic acid during exercise was significantly reduced for the paretic leg.
3. During one-leg exercise, oxygen and glucose uptakes by the working leg were similar for the paretic and non-paretic leg but lactate release was significantly greater for the paretic leg during exercise (30–45%).
4. The concentrations of ATP and creatine phosphate in the basal state were similar for the two legs. ATP and creatine phosphate fell significantly in the two legs during both the two-leg and the one-leg exercise period. The most marked decrease in ATP was noted for the paretic leg during one-leg exercise. The pattern of glycogen depletion during one-leg exercise for the paretic leg indicated primarily activation of the type II fibres. In contrast, the depletion pattern for the non-paretic leg suggested mainly recruitment of type I fibres.
5. The results indicate that, during exercise, paretic muscle shows a reduced blood flow, an augmented lactate production and a diminished capacity to oxidize free fatty acids. These metabolic derangements may be referrable to an augmented number and increased activation of type II muscle fibres as well as to alterations in the structure of muscle mitochondria. In addition, the present study indicates that one-leg exercise should be preferred to two-leg exercise when studying leg muscle circulation and metabolism in hemiparetic patients.
Total Protein Synthesis in Elderly People: A Comparison of Results with [15N]glycine and [14C]leucine
Authors: Golden M. H. N. , Waterlow J. C. 
Published: August 2015

1. Total body protein turnover was studied in six elderly patients.
2. During the study they were fed by continuous infusion of a liquid formula through a nasogastric tube. l-[1-14C]Leucine and [15N]glycine were infused at a constant rate for 30 h. The labelled glycine was infused into the intragastric line; the labelled leucine was given either by this route or intravenously.
3. The specific radioactivity of free leucine in plasma and the rate of output of 14CO2 in expired air both reached a plateau at 10 h, and remained constant until the end of the infusion at 30 h.
4. The 15N abundance in urinary urea and total N was very similar. In neither was a plateau reached by 30 h but in four out of the six patients the abundance in urinary NH4+ had attained a plateau by the end of the infusion.
5. Flux rates and rates of protein synthesis were calculated in four ways: (A) from the specific radioactivity of plasma leucine at plateau; (B) from the proportion of dose excreted as 14CO2 at plateau; (C) from the final rates of 15N excretion in urea or total urinary N; (D) from the final or plateau rates of 15N excretion in urinary NH4+.
6. On average, the estimates of synthesis rate obtained by methods B and C agreed closely; those given by methods A and D were lower. Methods A, B and D ranked the individual patients in almost identical order.
7. The comparison of methods makes it possible to examine the validity of the assumptions on which the different methods depend. Method B is probably theoretically the most satisfactory and, of the methods used in this work, probably gives the best estimate of the absolute turnover rate. The other methods can be used for comparative purposes.
8. The results suggest that the rate of protein turnover is reduced in the elderly, compared with younger subjects.
Two Methods for Determination of Renin Secretion Rates in Rats
Authors: Iaina A. , Nakash I. , Reisin E. , Spivack B. , Eliahou H. E. 
Published: August 2015

1. Renin secretion rates in normal rats were determined with two different methods: (a) the product of renal plasma flow as measured by sodium p-aminohippurate and the difference between renal and peripheral vein renin activity; (b) the product of this latter difference and the renal plasma flow as calculated from the clearance and extraction of inulin.
2. The renin secretion rates, as calculated by these two methods, were not significantly different (P > 0·1) and were found to be highly correlated (r = 0·943; P < 0·001).
Detection of Na+ and K+ in the Rat Adrenal Cortex with the Electron Microprobe
Authors: Decorzant C. , Riondel A. M. , Philippe M.-J. , Bertrand J. , Vallotton M. B. 
Published: August 2015

1. In order to demonstrate whether modification of aldosterone secretion is mediated by parallel changes of K+ in the adrenal zona glomerulosa, the total (intracellular + extracellular) Na+ and K+ content of the rat adrenal cortex was determined with the electron microprobe.
2. Groups of rats were submitted to one of the following dietary regimens: standard, low Na+, high K+ or high Na+.
3. Distribution of Na+ and K+ across the zona glomerulosa and zona fasciculata was compared. Standards of known electrolyte concentration were also analysed.
4. The [Na+] was found to be greater in the zona glomerulosa than in the zona fasciculata but K+ was distributed evenly in both zones. This was independent of dietary regimen.
5. Aldosterone production, assessed by plasma aldosterone concentrations, could not be correlated with zona glomerulosa K+ content.
Intracellular pH and Bicarbonate Concentration as Determined in Biopsy Samples from the Quadriceps Muscle of Man at Rest
Authors: Sahlin K. , Alvestrand A. , Bergström J. , Hultman E. 
Published: August 2015

1. A method for measuring intracellular pH and bicarbonate concentration of human muscle is described.
2. Muscle biopsies from the quadriceps muscle of 13 healthy subjects at rest were analysed for acid-labile carbon dioxide and volume of extra- and intra-cellular water. Extracellular water volume was estimated from the chloride content and intracellular water volume from the potassium content, or alternatively derived from the sample weight.
3. The measured total carbon dioxide content in muscle was 9·84 ± 1·39 mmol/kg.
4. Assuming a normal membrane potential (88 mV) and Pco2 of muscle equal to venous blood, calculated intracellular pH was 7·00 ± 0·06 and intracellular bicarbonate concentration was 10·2 ± 1·2 mmol/l of water.
Effect of Inhibition of Prostaglandin Synthesis on the Natriuresis Induced by Saline Infusion in Man
Authors: Mountokalakis Th. , Karambasis Th. , Mayopoulousymvoulidou D. , Merikas G. 
Published: August 2015

1. The effect of oral administration of an inhibitor of prostaglandin synthetase, indomethacin, on the natriuresis induced by the infusion of sodium chloride (saline) was studied in 11 healthy volunteers.
2. The administration of indomethacin did not alter sodium excretion before saline infusion, but it resulted in a significant increase of the natriuresis after saline infusion. This increase was not accompanied by any change in post-infusion urine flow rate or free water reabsorption.
3. It is suggested that intrarenal prostaglandins might suppress the natriuretic effect of saline infusion, probably by increasing sodium reabsorption in the distal nephron.
Angiotensin II Blockade before and after Marked Sodium Depletion in Patients with Hypertension
Authors: Van Hoogdalem P. , Donker A. J. M. , Leenen F. H. H. 
Published: August 2015

1. Angiotensin II blockade before and after marked sodium depletion in patients with hypertension [unilateral renovascular (eight), bilateral renovascular (four) and essential (four)] was performed by intravenous administration of the angiotensin II antagonist Sar1-Ala8-angiotensin II (saralasin).
2. On normal sodium intake, saralasin decreased mean blood pressure by 8 mmHg in the unilateral renovascular group, by 6 mmHg in the bilateral renovascular group and increased it by 3 mmHg in the essential hypertensive group. After sodium depletion saralasin decreased mean blood pressure by 33 mmHg, 35 mmHg and 18 mmHg respectively. The saralasin-induced decrease in blood pressure significantly correlated with the log of the initial plasma renin activity.
3. Saralasin infusion decreased effective renal plasma flow (ERPF) in all three hypertension subgroups, both on normal sodium intake and after sodium depletion. Glomerular filtration rate decreased in direct relation to the hypotensive effect of saralasin but ERPF showed this relationship only after sodium depletion. On normal sodium intake saralasin increased filtration fraction by 17%, but decreased it by 7% after sodium depletion.
4. It is concluded that the hypotensive action of saralasin closely correlates with the value of circulating plasma renin activity, apparently independent of the aetiology of the hypertension. The decrease in ERPF during saralasin infusion in the patients on normal sodium intake seems mainly related to the agonistic activity of saralasin, but that after sodium depletion to the hypotensive effect of saralasin.
Intensive Iron-Chelation Therapy with Desferrioxamine in Iron-Loading Anaemias
Authors: Pippard M. J. , Callender S. T. , Weatherall D. J. 
Published: August 2015

1. Urinary iron excretion after desferrioxamine has been examined in nine patients with different iron-loading anaemias. Particular attention has been paid to individual variation in response and the kinetics of iron removal in order to determine the most efficient and convenient method of administration.
2. Twelve-hour subcutaneous infusions of desferrioxamine were comparable with intravenous infusions and gave a mean value of 62% more iron excretion than similar intramuscular bolus doses (range 20–125%).
3. Increasing doses as 12 h subcutaneous infusions produced a linear increase in iron excretion, which was followed by a tendency to reach a plateau. Iron excretion varied greatly between patients, was not related solely to age or estimated iron load, and in most cases was increased by ascorbic acid saturation.
4. Maximum iron-excretion rates were achieved after 3–6 h and then maintained throughout an infusion. With bolus injections excretion rates declined rapidly after the first 6 h, during which approximately 60% of the total iron excretion occurred.
5. The dose and method of administration should be ‘tailor-made’ for each patient. Overnight 12 h subcutaneous infusions can be both as effective as similar doses given over 24 h and a practical way of achieving substantial negative iron balance.
6. Since children receiving regular blood transfusions for congenital anaemias such as thalassaemia usually die at the end of the second decade, this approach to iron chelation offers the possibility of alleviating what have hitherto been fatal iron-loading states.
Characterization of Immunoreactive Angiotensin in Canine Cerebrospinal Fluid as Des-Asp1-Angiotensin II
Authors: Hutchinson J. S. , Csicsmann J. , Korner P. I. , Johnston C. I. 
Published: August 2015

1. Immunoreactive angiotensin II was measured in cerebrospinal fluid of four normal dogs.
2. The migration of this immunoreactive angiotensin II on polyacrylamide-slab gel electrophoresis was identical with the migration of the heptapeptide, Des-Asp1-angiotensin II, in each case.
3. The biological activity of the material from canine cerebrospinal fluid in a pressor bioassay was similar to that of Des-Asp1-angiotensin II.
4. The pressor activity of the canine material was abolished by treating the pressor bioassay rat with a competitive antagonistic analogue, Sar1-Ala8-angiotensin II.
5. The results suggest that the biologically active immunoreactive angiotensin II present in normal canine cerebrospinal fluid is composed mainly of the heptapeptide fragment of angiotensin II, Des-Asp1-angiotensin II.
Metabolism in Vitro of 25-Hydroxycholecalciferol in Chicks Fed on Phosphorus-Deficient Diets
Authors: Swaminathan R. , Sommerville Barbara A. , Care A. D. 
Published: August 2015

1. Three groups of 10-days-old chicks were fed on one of three diets having phosphorus contents of 0·08 mol/kg, 0·14 mol/kg or 0·21 mol/kg. Ten days later duodenal calcium absorption by the ligated loop technique in vivo, and plasma calcium and phosphorus concentrations, were measured. In addition the metabolism in vitro of 25-hydroxycholecalciferol [25-(OH)D3] by kidney homogenates was studied.
2. In the low phosphorus group (0·08 mol/kg) calcium absorption and the activity of 25-(OH)D3-1-hydroxylase were significantly higher than those of the high phosphorus group (0·21 mol/kg). However, in the medium phosphorus group (0·14 mol/kg), calcium absorption was significantly higher although the activity of 25-(OH)D3-1-hydroxylase was not significantly higher when compared with the high phosphorus group (0·21 mol/kg).
3. It is concluded that in phosphorus deprivation, unlike in calcium deprivation, a diet very low in phosphorus is required to stimulate the renal 25-(OH)D3-1-hydroxylase activity.
Muscle Electrolytes and Fluid Compartments in Six Children with Bartter's Syndrome
Authors: Delaporte Christine , Stulzaft J. , Loirat C. , Broyer M. 
Published: August 2015

1. Muscle electrolyte (Na, K, Cl, P) concentrations and fluid compartments of six children with Bartter's syndrome were compared with those of 17 control children. From four of the patients biopsies were taken twice, before and after treatment with potassium chloride and spironolactone. Muscle electrolytes were determined by neutron activation in tissue sampled by needle biopsy. Results were expressed in relation to fat-free dry solids. Trapped extracellular fluid was calculated from the chloride space, a normal resting membrane potential being assumed.
2. In hypokalaemic patients total muscle potassium (Km) (33·0 ± 2·1 sem) was below the normal range (43·8 ± 0·7 mmol/100 g of fat-free dry solids) in all cases. When plasma potassium was corrected, total muscle potassium returned to normal. There was a significant correlation between plasma potassium concentration and total muscle potassium (r = 0·87; P < 0·01). Total muscle sodium (Nam) was increased: 18·7 ± 2·9 mmol/100 g in hypokalaemic patients (11·3 ± 0·6 mmol/100 g of fat-free dry solids in control subjects). A negative relationship was found between Km and Nam (r = —0·85; P < 0·01). With treatment, intracellular potassium concentration remained low (142·0 mmol/l of intracellular water; control, 163·0 ± 2·4 mmol/l) despite normokalaemia and normal total muscle potassium. Muscle phosphorus (32·1 ± 1·8 mmol/100 g) was higher than in control subjects (28·1 ± 0·4 mmol/100 g of fat-free dry solids).
3. These data suggest that sodium replaces potassium in muscle of patients with Bartter's syndrome. The low intracellular potassium concentration in the binephrectomized sister of one child and in all treated children suggests that there are generalized anomalies in the handling of cations in Bartter's syndrome.
Parathyroid Hormone-like Biological Activity in Urine
Authors: Wolf N. Nijs-De , De Nutte N. , Brauman H. , Corvilain J. 
Published: August 2015

1. The parathyroid hormone-like biological activity of concentrated urine was measured by the increase of plasma calcium concentration after intravenous injection of the sample into chickens.
2. Urine was tested in hypoparathyroid patients, normal volunteer subjects, primary hyperparathyroid patients before and after surgery and patients with secondary hyperparathyroidism.
3. In primary and secondary hyperparathyroidism the biological activity was significantly higher than in urine from normal subjects, which was in turn significantly higher than the activity in the urine of hypoparathyroid patients. This bioactivity diminished after surgical removal of a hyperparathyroid adenoma.
4. Decreased activity after trypsinization indicated the peptidic nature of the hypercalcaemic substance.
Effect of Streptozotocin-Diabetes on the Local and General Responses to Injury in the Rat
Authors: Elebute E. A. , Little R. A. 
Published: August 2015

1. The effects of streptozotocin-diabetes on the local and general responses to a 4 h period of bilateral hind-limb ischaemia in the rat have been investigated. The rats were injured 48 h after the intravenous injection of the streptozotocin.
2. Less fluid was lost from the circulation into the injured limbs after injury in the diabetic rats and this was directly related to the severity of the diabetes, but could not be explained by dehydration. However, when the diabetic and non-diabetic injured rats were considered together there was a significant negative correlation between either plasma osmolality or plasma glucose concentration and water content in the injured hind limb.
3. The relationship between plasma glucose concentration and plasma osmolality was changed by injury such that, particularly in the injured diabetic rats, plasma osmolality at a given glucose concentration was higher than that predicted from the relationship between these variables in the uninjured rat.