bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the Appearance of Radiolabelled Vitamin D3 and 25-Hydroxy-Vitamin D3 in the Chylomicron Fraction of Plasma after Oral Administration in Man
Authors: Compston Juliet E. , Merrett Anne L. , Hammett F. G. , Magill P. 
Published: August 2015

1. The uptake of either orally administered [3H]vitamin D3 or 25-[3H]hydroxy-vitamin D3 into the chylomicron fraction of plasma was studied in 12 healthy male subjects.
2. The amount of [3H]vitamin D3 in the chylomicron fraction expressed as a percentage of the total plasma radioactivity was higher than that of 25-[3H]hydroxy-vitamin D3.
3. It is suggested that the mechanism of intestinal absorption of vitamin D and 25-hydroxy-vitamin D may differ in man, the absorption of 25-hydroxy-vitamin D possibly being less dependent on bile acids.
Evidence of Altered Copper Metabolism in Patients with Chronic Pancreatitis
Authors: Braganza Joan M. , Klass H. J. , Bell M. , Sturniolo G. 
Published: August 2015

1. The copper content of duodenal juice obtained during secretin-pancreozymin tests has been compared in 12 healthy volunteers and 12 patients with chronic pancreatitis in whom normal gall-bladder function was confirmed by oral cholecystography. Of the 12 chronic pancreatitis patients 10 had not received any pancreatic supplement, one was on supplements for 10 years and one for 2 years.
2. In the control subjects the output of copper secretion into the duodenum displayed two phases: a sharp increase in the first 10 min after secretin [intravenous injection of 2 Crick-Harper-Raper units/kg of secretin (Boots)] and a second sharp rise in the first 10 min after pancreozymin [intravenous injection of 2 Crick-Harper-Raper units/kg of pancreozymin (Boots)].
3. In patients with chronic pancreatitis the pattern of copper secretion was similar to that of control subjects, but in the first 10 min after secretin the output of copper was significantly higher (P &lt; 0.001). The post-secretin output of bilirubin was also higher in chronic pancreatitis (P &lt; 0.02), but the volume of duodenal juice (P &lt; 0.01), the outputs of bicarbonate (P &lt; 0.001) and trypsin (0.05 &lt; P &lt; 0.1) were reduced compared with those of control subjects. The parallel increases in outputs of bilirubin and copper suggested that bile was the source of the increased copper in this group.
4. In the two chronic pancreatitis patients who received pancreatic supplements the post-secretin copper outputs were within normal limits. In a further group of five chronic pancreatitis patients who had been taking pancreatic supplements for many years the post-secretin copper output was not only less than in untreated chronic pancreatitis patients (P &lt; 0.001), but less than in control subjects (P &lt; 0.005). The output of bilirubin was similarly reduced (P &lt; 0.01 and &lt; 0.02 respectively).
5. Since bile is the major route for disposal of absorbed copper and since, under normal steady-state conditions, biliary copper excretion provides an index of copper absorption, our data suggest differences in long-term copper absorption between untreated and treated chronic pancreatitis patients. A component in pancreatic juice may therefore limit copper absorption under normal circumstances. Untreated chronic pancreatitis patients (who lack this factor) would absorb more copper, producing, over many years, an increase in hepatic and whole-body copper content. Long-term feeding of pancreatic supplements, by reducing copper absorption, would gradually deplete whole-body copper content.
Protein Degradation in Human Skeletal Muscle Tissue: The Effect of Insulin, Leucine, Amino Acids and Ions
Authors: Lundholm K. , Edström S. , Ekman L. , Karlberg I. , Walker P. , Scherstén T. 
Published: August 2015

1. The protein degradation rate of human skeletal muscle was evaluated in vitro in isolated fibre bundles from the rectus abdominus muscle by measuring the tyrosine released from muscle tissue proteins. Protein metabolism in this semi-intact preparation was compared with that of the intact extensor digitorum longus muscles from rats under the same experimental conditions.
2. Protein balance was negative in both preparations, but protein synthesis and degradation were two to three times higher in the rat muscles. Tyrosine was released at a constant rate for at least 3 h of incubation independent of whether protein synthesis was inhibited or not. Disintegration of the muscle fibres more than doubled the tyrosine release rate. Human red gastrocnemius muscle showed 37% higher degradation rate compared with the predominantly white rectus abdominus muscle. The half-life of human skeletal muscle protein in vitro was estimated to be 20 days when calculated from the rate of tyrosine release.
3. The addition of leucine to the incubation medium decreased the rate of protein degradation, which was further decreased by the addition of other amino acids. Insulin did not influence the protein degradation rate during 2 h of incubation. This did not reflect a lack of sensitivity to insulin of the preparation, since protein synthesis responded to insulin. Calcium (5 mmol/l) stimulated and zinc (0.1 mmol/l) inhibited the protein degradation.
4. This experimental system may be suitable as an additional tool for evaluating protein degradation in human skeletal muscles.
Renin and Aldosterone Release during Sympathetic Stimulation in Tetraplegia
Authors: Mathias C. J. , Frankel H. L. , Davies I. B. , James V. H. T. , Peart W. S. 
Published: August 2015

1. The effect of endogenous sympathetic stimulation (induced by urinary bladder stimulation) and intravenous infusion of noradrenaline and isoprenaline on blood pressure, heart rate and levels of plasma renin activity and plasma aldosterone were studied in six tetraplegic patients. Data from infusion studies were compared with data from six normal subjects studied in an identical manner.
2. Bladder stimulation in the tetraplegic patients caused a marked rise in blood pressure and fall in heart rate, but no change in plasma renin activity or plasma aldosterone.
3. Noradrenaline infusion resulted in an enhanced pressor response in the tetraplegic patients when compared with the normal subjects. Heart rate fell in both groups. Plasma renin activity and plasma aldosterone did not change in either group.
4. Isoprenaline infusion caused a fall in both systolic and diastolic blood pressure in the tetraplegic patients, unlike the normal subjects in whom there was a rise in systolic and a fall in diastolic blood pressure. Heart rate and plasma renin activity rose in both groups. Plasma aldosterone did not change in either group.
5. We conclude that in tetraplegic patients neither endogenous sympathetic stimulation by bladder stimulation nor infusion of noradrenaline raises plasma renin activity. Isoprenaline increases plasma renin activity to the same extent as in normal subjects. Renin release mechanisms in tetraplegic patients therefore do not appear to be hypersensitive to catecholamines. Plasma aldosterone is not influenced by any of the stimuli.
Activities of Hexokinase, Phosphofructokinase, Fructose Bisphosphatase and 2-Oxoglutarate Dehydrogenase in Muscle of Normal Subjects and Very Ill Surgical Patients
Authors: King R. F. G. J. , MacFie J. , Hill G. 
Published: August 2015

1. The activities of hexokinase, phosphofructokinase, fructose bisphosphatase and 2-oxoglutarate dehydrogenase have been measured in the vastus lateralis and rectus abdominus muscle of normal human subjects and in very ill surgical patients.
2. The activities of these enzymes in the muscle of control subjects were similar to the pattern seen in the skeletal muscle of other mammals and lower vertebrates.
3. Fructose bisphosphatase and phosphofructokinase activities were significantly lower in the muscle of ill patients although the depression of the activity of fructose bisphosphatase was much greater than that of phosphofructokinase in both muscle types of ill patients.
4. The maximum rate of cycling in the fructose 6-phosphate-fructose 1,6-diphosphate cycle may be altered in the ill.
5. This decreased cycling may have a direct influence on the sensitivity of glycolysis to regulators such as the adenine nucleotides and may reduce the ability to maintain body temperature.
6. Increased glycogen synthesis in these muscles may indicate that the role of fructose bisphosphatase is unlikely to be solely in glycogen resynthesis.
Plasma Noradrenaline Concentration and α-Adrenoceptor-Mediated Vasoconstriction in Normotensive and Hypertensive Man
Authors: Kiowski W. , Bühler F. R. , Vanbrummelen P. , Amann F. W. 
Published: August 2015

1. Plasma noradrenaline concentrations and blood pressure were measured in 45 patients with essential hypertension and 34 matched normotensive subjects. Plasma noradrenaline was similar in both groups, but in the hypertensive patients plasma noradrenaline correlated with blood pressure.
2. The increase in forearm flow in response to an intra-arterial infusion of phentolamine was determined in 12 of the hypertensive and 14 of the normotensive subjects to assess the α-adrenoceptor-mediated component of vascular resistance. Although the dilator response to phentolamine was similar in both groups, in the hypertensive patients it was correlated with the control plasma noradrenaline (r = 0.83, P&lt;0.01) as well as the height of mean blood pressure (r = 0.73, P&lt;0.01).
3. These results suggest that in hypertensive patients plasma noradrenaline can be a marker for both sympathetic activity and the α-adrenoceptor-mediated component of vascular resistance.
Serial Estimations of Carbon Monoxide Diffusing Capacity in Intrapulmonary Haemorrhage
Authors: Greening A. P. , Hughes J. M. B. 
Published: August 2015

1. Serial estimations of the diffusing capacity for carbon monoxide, with a standard single-breath technique, were used to assist the monitoring of disease activity in patients at risk from intrapulmonary haemorrhage.
2. A reversible rise in diffusing capacity for carbon monoxide per unit alveolar volume (DLco/VA) of 50% or more above baseline values was detected on 61 occasions and in the diffusing capacity for carbon monoxide (DLco) alone on 45 occasions in 39 patients.
3. Concurrent with these rises in DLco/VA or DLco, two or more traditional indicators of intrapulmonary haemorrhage (haemoptysis, abrupt fall in haemoglobin concentration, chest X-ray opacities) were found on 47 occasions.
4. In the appropriate clinical context, acute reversible rises in DLco/VA or DLco reflect active intrapulmonary haemorrhage.
Deamination of Adenosine 5′-Phosphate and Adenosine as a Possible Source of Ammonia in Human and Bovine Parotid Glands
Authors: Bereznowski Z. , Stankiewicz A. , Makarewicz W. 
Published: August 2015

1. The liberation of ammonia from adenosine 5′-phosphate (AMP) and adenosine and the release of inorganic phosphate from AMP were investigated in homogenates of bovine and human parotid glands.
2. Adenosine phosphate deaminase (AMP deaminase) was purified from bovine and human parotid glands. The enzyme preparations obtained were free from adenosine deaminase and 5′-nucleotidase activities.
3. AMP incubated with human parotid gland homogenate produced inosine 5′-phosphate, adenosine, inosine and ammonia. The amount of ammonia accumulating in the incubation mixture was equal to the sum of inosine 5′-phosphate plus inosine.
4. These results demonstrate the presence in human parotid of AMP deaminase and adenosine deaminase.
Effects of Salt and Water Depletion on the Early Phase of Hypertension in Goldblatt two-Kidney Hypertensive Dogs
Authors: Watson M. L. , McCormick J. , Thom A. , Whelpdale P. , Ungar A. 
Published: August 2015

1. Hypertension was induced in dogs by partial occulsion of one renal artery, the opposite kidney remaining intact, and the changes in blood pressure, plasma renin activity, aldosterone and prostaglandin E (PGE) were monitored.
2. Two days after induction of hypertension, the retained sodium and water were removed by haemodialysis and the animals were then maintained on a low dietary intake of sodium for the following 7 days.
3. Removal of the accumulated sodium and water had no immediate effect on blood pressure, but during the ensuing 7 days there was a small decrease in blood pressure, which again increased after re-institution of a normal sodium intake.
4. Plasma renin activity and aldosterone increased during development of hypertension and remained elevated during the period of sodium restriction.
5. Sodium and water retained during the development of hypertension was not responsible for the elevated blood pressure.
6. The concentration of PGE in arterial plasma and renal venous plasma from the undamped kidney were unchanged during the study, although we have previously shown that in the absence of sodium depletion, PGE rises.
7. PGE released from the kidney may be important in mediating the excretion of sodium and water that is retained during the development of renal hypertension.
A Method for Assessing Responses of Small Arteries in Man: Effect of Physiological and Pharmacological Stimuli
Authors: Robinson B. F. , Dobbs R. J. , Kelsey C. R. , Saverymuttu S. 
Published: August 2015

1. A method has been developed for estimating resistance to blood flow in the collateral arteries around the elbow. Arterial pressure is recorded continuously from the radial artery and blood flow in the forearm and hand is measured by venous occlusion plethysmography. The brachial artery is occluded for short periods, and the pressure drop across the collaterals and the flow through them are determined. From these observations an index of resistance can be calculated.
2. During 2 min occlusions of the brachial artery, collateral arterial resistance fell progressively to reach a level that was on average 45% lower than the initial resistance (P &lt; 0.01).
3. There was an inverse relation between distending pressure in the collateral arteries and calculated resistance.
4. Ergotamine tartrate (0.25 mg intravenously) increased collateral resistance by an average of 135%. Glyceryl trinitrate (0.5 mg sublingually) reduced collateral resistance by an average of 45%. Hydrallazine and isoprenaline had an inconsistent dilator effect; the direct action of these drugs may have been offset by the reduction in distending pressure which they induced.
5. The elbow collateral arteries provide a useful model for studying physiological and pharmacological responses of small limb arteries in man.
The Disposition of Intravenous Potassium in Normal Man: The Role of Insulin
Authors: Sterns R. H. , Guzzo J. , Feig P. U. 
Published: August 2015

1. Potassium infusion causes an increase in immunoreactive insulin levels in dogs, but either a small (30%) or no increase in humans. Since insulin stimulates the uptake of K+ by cells, a regulatory role for K+-induced insulin release has been postulated. To study the role of insulin in regulating cellular K+ uptake, six fasting normal volunteer subjects underwent two K+ infusions on separate days. Both infusions delivered 0.6 mmol h−1 kg−1 for 3 h. In one subject glucose was simultaneously infused at 0.67 mmol h−1 kg−1 (a rate known to increase peripheral insulin levels by 40–100%); the other infusion contained no glucose.
2. Plasma insulin levels did not increase during the glucose-free infusions. During glucose-containing infusions, insulin levels were 40% higher than those during glucose-free infusions. Despite this, neither urinary potassium excretion nor the increment in plasma K+ concentration or the calculated cellular K+ uptake differed significantly during the 3 h of glucose-free and glucose-containing infusions respectively.
3. These data do not support the view that potassium-induced insulin secretion regulates cellular potassium uptake within the physiological range of plasma K+ concentration.
Acute Effects of Captopril on Blood Pressure and Circulating Hormone Levels in Salt-Replete and Depleted Normal Subjects and Essential Hypertensive Patients
Authors: Millar J. A. , McGrath B. P. , Matthews P. G. , Johnston C. I. 
Published: August 2015

1. The acute effects of a single oral dose of captopril on blood pressure, pulse rate and circulating levels of angiotensin I (ANG I), angiotensin II (ANG II), renin, bradykinin and catecholamines were studied in three groups: eight normal subjects, six salt-depleted normal subjects and 16 patients with essential hypertension.
2. Captopril treatment did not cause any significant fall in supine blood pressure in salt-replete normal subjects or patients with untreated essential hypertension but was associated with a fall in mean blood pressure from 85 ± 2 to 75 ± 2 mmHg in salt-depleted normal subjects and from 131 ± 7 to 117 ± 5 mmHg in patients with essential hypertension treated with diuretics. There was no change in pulse rate in any group.
3. Hormonal responses to captopril were qualitatively similar in the three groups and consisted of significant falls in ANG II with corresponding increases in ANG I and plasma renin concentration. The changes in plasma renin concentration and ANG I were greater in salt-depleted normal subjects (mean values at 90 min were 1140% and 990% of basal levels respectively) than in salt-replete normal subjects (410%, 190%) and were blunted in patients with essential hypertension (140%, 120%). Blood bradykinin, noradrenaline and adrenaline concentrations did not change after captopril in any group.
4. The parallel fall in blood pressure and ANG II levels in salt-depleted normal subjects is consistent with maintenance of blood pressure by increased levels of ANG II in sodium depletion.
5. The failure of captopril to reduce acutely blood pressure in patients with essential hypertension despite suppression of plasma ANG II and without change in circulating bradykinin confirms that the renin-angiotensin system does not play a primary role in essential hypertension.
[Asp1, Val5] Angiotensin-(1–8)octapeptide Does Not Stimulate Aldosterone Secretion in Sodium-Depleted Sheep
Authors: Scoggins B. A. , McDougall J. G. , Butkus Aldona , Coghlan J. P. , Denton D. A. , Hardy K. J. , Wright R. D. 
Published: August 2015

1. To test the hypothesis that [Asp1,Val5]-angiotensin-(1–8)octapeptide ([Asp1,Val5]ANG II) is a more potent agonist to aldosterone secretion in the sodium-depleted animal than is [Asn1,Val5]angiotensin-(1–8)octapeptide ([Asn1,Val5]ANG II), local adrenal arterial infusion of the two peptides has been carried out in sheep with cervical adrenal autotransplants.
2. Neither [Asp1,Val5]ANG II nor [Asn1,Vak5]-ANG II further stimulated the increased level of aldosterone secretion in conscious moderately sodium-depleted sheep. Greater sodium deficiency further increased aldosterone secretion.
3. The conclusion of Campbell, Schmitz & Itskovitz [Clinical Science (1979), 56, 325–333] that the free acid form of angiotensin II was a more potent agonist of aldosterone secretion than was the amide form under conditions of reduced sodium status is not supported by studies in sodium-depleted sheep.
Arterial Plasma Histamine after Exercise in Normal Individuals and in Patients with Exercise-Induced Asthma
Authors: Hartley J. P. R. , Charles T. J. , Monie R. D. H. , Seaton A. , Taylor W. H. , Westwood A. , Williams J. D. 
Published: August 2015

1. Arterial plasma histamine concentrations, forced expiratory volume in 1.0 s (FEV1.0) and peak expiratory flow rate were determined in nine patients with exercise-induced asthma and in five control subjects before and after 8 min of cycle-ergometer exercise.
2. In the controls neither FEV1.0 nor peak expiratory flow rate fell by more than 5% in any individual during the 30 min postexercise period. The asthmatic patients all experienced a fall in FEV1.0 or peak expiratory flow rate, or both, of 15% or more in the period 5–20 min after completion of the exercise.
3. There was no difference between the control subjects and the asthmatic patients in the plasma histamine response to exercise. In both groups there was an insignificant rise of about 40% during exercise, although the initial levels were higher in the asthmatic patients.
4. The mean plasma histamine peak of the asthmatic patients preceded the mean maximal fall of FEV1.0 and peak expiratory flow rate by approximately 15 min. However, no positive correlation was found between rise in, or peak, plasma histamine levels and decrease in lung function.
5. Three non-atopic asthmatic patients had a significantly higher mean plasma histamine concentration during exercise than had the atopic subjects.
6. A strong positive correlation in asthmatic patients, and asthmatic and control subjects together was found between age and mean postexercise plasma histamine concentrations.
7. The results do not support a direct role for histamine in the production of exercise-induced asthma.
Respiratory Activity of the Vocal Cords in Normal Subjects and Patients with Airflow Obstruction: An Electromyographic Study
Authors: Payne Julia , Higenbottam T. , Guindi G. 
Published: August 2015

1. A surface electrode was used to record electromyographic activity of the posterior crico-arytenoid muscle during breathing in normal subjects and patients with airflow obstruction.
2. Phasic activity of the posterior crico-arytenoid muscle was demonstrated. This was present on inspiration and absent on expiration.
3. Phasic inspiratory activity in normal subjects was present only during periods of voluntary hyperventilation, increasing with tidal volume, whereas in patients with airflow obstruction inspiratory activity was present even during resting breathing and failed to increase further during voluntary hyperventilation.
4. The posterior crico-arytenoid muscle may be considered as an inspiratory muscle acting analogously to other accessory respiratory muscles.
Haemodynamics, Plasma Noradrenaline and Plasma Renin in Hypertensive and Normotensive Teenagers
Authors: Hofman A. , Roelandt J. T. R. C. , Boomsma F. , Schalekamp M. A. D. H. , Valkenburg H. A. 
Published: August 2015

1. Plasma noradrenaline, active and inactive plasma renin, cardiac index and total peripheral vascular resistance were studied in 41 subjects, initially aged 10–19 years, who were followed up for at least 2 years after a blood pressure reading of 140 and/or 90 mmHg or more (initial hypertensives) and in 41 normotensive control subjects selected from the same population and matched for age, sex and body-mass index.
2. The initial hypertensive subjects had a lower mean cardiac index (3.63 ± sd 0.83 vs 4.00 ± 0.89 litre min−1 m−2), a higher mean total peripheral resistance (26.8 ± 5.7 vs 22.8 ± 5.5 units) and a higher mean plasma noradrenaline concentration (336 ± 146 vs 281 ± 126 pg/ml) than the control subjects.
3. Mean plasma noradrenaline concentration was higher in initial hypertensive subjects with a high active renin concentration than in those with a normal renin concentration (442 ± 70 vs 324 ± 100 pg/ml).
4. A weight-adjusted standardized regression coefficient of 0.77 between active plasma renin concentration and left ventricular mass was found in normotensive control subjects.
5. These findings are at variance with the existence of a hyperkinetic phase in young hypertensive subjects and suggest that sympathetic overactivity may be related to early essential hypertension through increase of peripheral vascular resistance.
Evaluation of the Mineralocorticoid Activity of 18-Hydroxycorticosterone
Authors: Huston G. , Martin V. I. , Al-Dujaili E. A. S. , Edwards C. R. W. 
Published: August 2015

1. The mineralocorticoid activity of 18-hydroxycorticosterone (18-OH-B) has been compared with that of aldosterone by using human bioassay in vivo with measurement of rectal potential difference and urinary log 10 Na+/K+ ratio.
2. A log-linear relationship was found between maximum change in rectal potential difference and increasing doses of aldosterone.
3. No mineralocorticoid activity could be demonstrated after an intravenous bolus and infusion of 18-OH-B.
4. The half-life of clearance of 18-OH-B was measured in three subjects and found to be 28, 48 and 24 min.