bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atrial natriuretic peptide: Physiological release associated with natriuresis during water immersion in man
Authors: Anderson J. V. , Millar N. D. , O'Hare J. P. , MacKenzie J. C. , Corrall R. J. M. , Bloom S. R. 
Published: August 2015

1. Thermoneutral water immersion produces a physiological increase of thoracic blood volume, raises central venous pressure and increases urinary sodium excretion by a hitherto ill-understood mechanism. We have investigated whether this enhanced sodium excretion could be mediated by the recently discovered natriuretic factor, atrial natriuretic peptide (ANP).
2. During water immersion there was a highly significant (P &lt; 0.001) twofold increase of the mean plasma ANP concentration and a doubling of the mean urinary sodium excretion. Both were unchanged during the control experiments.
3. These results are consistent with the hypotheses (a) that ANP is released into plasma in response to central blood volume expansion and (b) that it functions as a natriuretic hormone in normal man under physiological conditions.
The combined effects of two pairs of mediators, adenosine with methacholine and prostaglandin D2 with histamine, on airway calibre in asthma
Authors: Hardy C. C. , Braddeng P. , Robinson C. , Holgate S. T. 
Published: August 2015

1. Mediators released from mast cells and secondary effector cells in the airways contribute to bronchoconstriction of allergic asthma. This study investigates methods for defining the effect of two inflammatory mediators on airway calibre in asthma.
2. In an initial study on three asthmatic subjects, subconstrictor (subthreshold) concentrations of two mast cell derived mediators, histamine and prostaglandin (PG) D2, produced similar displacement to the left of a histamine concentration–specific airways conductance (sGaw) response curve. With both agonists enhancement of histamine-induced bronchoconstriction was greater at low histamine concentrations. Since potentiation of histamine-induced bronchoconstriction was independent of the class of subconstrictor agent given, it is likely to represent a physiological rather than a pharmacological interaction.
3. During provoked asthma different constrictor mediators are likely to be released simultaneously into the airways. A method was therefore devised to investigate the combined effect of equiconstrictor concentrations of two mediators on airway calibre.
4. Two pairs of inhaled bronchoconstrictor agonists were chosen for study: adenosine with methacholine and PGD2 with histamine. For each agonist, concentration–sGaw response curves were constructed, from which were derived the provocation concentrations of agonist causing a 25% fall in sGaw from baseline (PC25) and required to further this to 50%(PC50_25).
5. On separate days, eight subjects received paired inhalations of methacholine–adenosine, methacholine–methacholine and adenosine–adenosine. The concentration used for the first inhalation was the PC25 value and for the second inhalation the PC50_25 value. Before, immediately after the first inhalation, and at regular intervals after the second inhalation, sGaw was followed for 30 min. In seven subjects the study was repeated, replacing methacholine with PGD2 and adenosine with histamine.
6. When methacholine was combined with adenosine, and PGD2 was combined with histamine the maximum falls in sGaw and rates of recovery after inhalation of the second mediator were not statistically different from those values observed with paired inhalations of the same mediators.
7. Thus, employing pharmacologically active concentrations of two pairs of constrictor mediators, which act through separate receptor mechanisms, we have been unable to demonstrate any pharmacological interaction on airway calibre in asthma.
Impaired sodium excretion in response to volume expansion induced by water immersion in insulin-dependent diabetes mellitus
Authors: O'Hare J. P. , Roland J. M. , Walters G. , Corrall R. J. M. 
Published: August 2015

1. The renal response to volume expansion produced by water immersion to the neck at 35°C was examined in eight young normotensive uncomplicated insulin-dependent diabetic subjects and in eight matched normal control subjects.
2. Both the diabetic and normal subjects manifested a renal response of natriuresis and kaliuresis on immersion, but the natriuretic response was reduced in the diabetic group. Thus the induced excretion of sodium over the 4 h of immersion was 40 ± 5 mmol (mean ± sem) in the normal group compared with 22 ± 4 mmol in the diabetic group (P &lt; 0.02).
3. In the normal subjects creatinine clearance did not change during immersion compared with pre-immersion control values while in the diabetic group it rose from pre-immersion control values of 112 ± 11 ml/min to a mean value of 127 ± 11 ml/min during immersion (P &lt; 0.01).
4. The diabetic subjects thus excreted less sodium despite an increased filtered load during water immersion. Fractional excretion of sodium was significantly reduced in the diabetic subjects compared with the normal control subjects (P &lt; 0.05).
5. The suppression of plasma renin and aldosterone was similar in normal and diabetic groups.
6. Tubular sodium retention could be an early functional change in the diabetic kidney, and be implicated in the development of diabetic nephropathy.
Effect of ganglionic blockade on endogenous circulating pancreatic polypeptide, vasoactive intestinal polypeptide, substance P, neurotensin and noradrenaline in healthy controls and long-term insulin-dependent diabetic patients
Authors: Kastrup Jens , Henrksen Jens H. , Pedersen Jesper Holst , Fahrenkrug Jan , Schaffalitzky de Muckadell Ove B. , Schwartz Thue , Parving Hans-Henrik , Christensen Niels Juel 
Published: August 2015

1. Plasma pancreatic polypeptide (PP), vasoactive intestinal polypeptide (VIP), substance P (SP), neurotensin (NT) and noradrenaline (NA) were measured in eight healthy subjects and 12 long-term insulin-dependent diabetic patients with and without autonomic neuropathy, before and after intravenous infusion of the ganglionic blocking agent trimethaphan camsylate, in order to determine the influence of the autonomic nervous system on the baseline values of the substances.
2. The basal levels of the measured substances were not significantly different in healthy subjects and patients with or without diabetic autonomic neuropathy.
3. In healthy subjects, the ganglionic blockade induced a significant decrease in PP (80%) (P &lt; 0.02), NA (58%) (P &lt;0.05), NT (27%) (P &lt; 0.05) and a significant increase in SP (30%) (P &lt; 0.05), while the VIP concentration remained unchanged.
4. The diabetic patients had nearly the same significant decrease in PP (68%) (P &lt; 0.01), NA (50%) (P &lt; 0.01), NT (22%) (P &lt; 0.02), VIP (21%) (P &lt; 0.05) and increase in SP (73%) (P &lt; 0.01). No relationship was found between the autonomic neuropathy and changes of the substances during ganglionic blockade.
5. The results indicate that the postganglionic part of the autonomic nervous system participates in the maintenance of a normal baseline level of PP, NT and NA, but not of VIP. The regulation of VIP may be disturbed in long-term diabetic subjects.
The exchange of blood-borne amino acids in the leg during abdominal surgical trauma: Effects of glucose infusion
Authors: Lund J. , Stjernström H. , Bergholm U. , Jorfeldt L. , Vinnars E. , Wiklund L. 
Published: August 2015

1. The exchange of plasma amino acids and glucose, lactate, glycerol and 3-hydroxybutyrate in the leg was studied in otherwise healthy patients undergoing elective cholecystectomy.
2. Seven patients were given a constant intravenous infusion of glucose at a rate of 1.1 mmol/min throughout the study. Seven other patients who received normal saline only served as a control group.
3. Measurement of leg blood flow and arterio-femoral venous differences of amino acids and other energy metabolites were made on four occasions: (I) before surgery, (II) 10 min after skin incision, (III) at the end of surgery, and (IV) 30 min after the end of anaesthesia.
4. The release of amino acids from the leg was comparable in the two groups before and during the early part of surgery. At the end of surgery the release of several individual amino acids, as well as the total release of amino acids, from the leg was higher in the patients given glucose infusion compared with the control patients.
5. The infusion of glucose prevented the intraoperative rise in arterial levels and uptake of 3-hydroxybutyrate in the leg. A high release of amino acids at the end of surgery was thus associated with low arterial levels of 3-hydroxybutyrate while the reverse pattern was seen in the control patients.
6. These effects of glucose infusion were qualitatively different from those seen in uninjured post-absorptive man.
Chlorpropamide–alcohol flush reaction and isoenzyme profiles of alcohol dehydrogenase and aldehyde dehydrogenase
Authors: Johnston C. , Saunders J. B. , Barnett A. H. , Ricciardi B. R. , Hopkinson D. A. , Pyke D. A. 
Published: August 2015

1. To investigate the enzymatic basis of the chlorpropamide–alcohol flush reaction (CPAF) we compared the isoenzyme profiles of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) from liver biopsies, and of ALDH alone from erythrocytes and leucocytes, in CPAF-positive and CPAF-negative subjects.
2. No differences were seen in ADH or ALDH phenotypes, or in the relative activities of the isoenzymes, between the two groups before chlorpropamide was given; in particular, no subjects showed the ‘null’ ALDH phenotype that is associated with the alcohol flush reaction in oriental subjects.
3. There was a significant decrease in erythrocyte ALDH activity after 7 days' treatment with chlorpropamide in CPAF-positive individuals but no such difference was seen in CPAF-negative subjects.
4. These results indicate that CPAF has a different enzymatic basis from the alcohol flush reaction of oriental subjects and suggest that in CPAF-positive subjects erythrocyte ALDH may be particularly susceptible to inhibition by chlorpropamide.
Respiratory and cardiovascular effects of central and peripheral intravenous injections of capsaicin in man: Evidence for pulmonary chemosensitivity
Authors: Winning A. J. , Hamilton R. D. , Shea S. A. , Guz A. 
Published: August 2015

1. The respiratory and cardiovascular effects of capsaicin injection into the superior vena cava and an arm vein were studied in three normal subjects.
2. No changes were seen in tidal volume, inspiratory time or expiratory time after capsaicin injection. Instantaneous heart rate, systolic blood pressure and diastolic blood pressure remained unchanged.
3. Central and peripheral intravenous injections of capsaicin but not control solution above a threshold of 0.5 μg/kg produced dose-dependent sensations sequentially in the chest, face, rectum and extremities. The chest sensation, a ‘raw, burning’ feeling, occurred 3–4 s after central capsaicin injection. No subject reported feeling breathless. In one subject the maximum tolerable dose of capsaicin (4 μg/kg) produced paroxysmal coughing 3.9 s after a central injection.
4. In two of the subjects capsaicin injection was repeated after inhalation of a 5% bupivacaine aerosol (aerodynamic mass median diameter 4.8, μm), sufficient to block the cough reflex to a 5% citric acid aerosol. Prior inhalation of local anaesthetic aerosol abolished the chest sensation after capsaicin injection; the other sensations were unaffected.
5. This study demonstrates that stimulation of receptors accessible from the pulmonary vascular bed does not evoke the pulmonary chemoreflex in conscious man but can produce coughing. It provides evidence for the existence of a nociceptive system of nerve endings in the lung parenchyma that can be blocked by inhaled local anaesthetic aerosol.
Vasopressin and catecholamine secretion during apomorphine-induced nausea mediate acute changes in haemostatic function in man
Authors: Grant P. J. , Hughes J. R. , Dean H. G. , Davies J. A. , Prentice C. R. M. 
Published: August 2015

1. Seven male volunteers were given apomorphine (14–20 μg/kg) subcutaneously on a total of ten occasions. Nausea was experienced on six occasions and on four occasions there was no effect.
2. Venous samples were taken before injection, at peak nausea and 20 min later for assay of factor VIII coagulant activity (FVIIIC), von Willebrand factor antigen (vWFAg), the ristocetin cofactor (FVIIIRiCof), euglobulin clot lysis time (ECLT), fibrinopeptide A (FPA), FPA generation time, activated partial thromboplastin time (APTT), vasopressin (aVP) and adrenaline.
3. During nausea plasma aVP concentrations rose from median values of 0.4 pg/ml (at time 0) to 76 pg/ml at peak nausea and fell to 32 pg/ml 20 min later. Adrenaline rose from 0.36 to 0.91 nmol/l (P &lt; 0.05) before falling to 0.55 nmol/l.
4. During nausea, FVIIIC rose from 100% to 143% (P &lt; 0.05) and to 214% (P &lt; 0.05) 20 min later. FVIIIRiCof and vWFAg showed similar changes. Plasminogen activator activity (106/ECLT2) rose from 23 units at time 0 to 592 units during nausea and 1135 units (P &lt; 0.05) after 20 min.
5. The APTT fell from 49 s to 44 s during the study, plasma FPA levels and the FPA generation time both remained unchanged.
6. On the four occasions nausea was not experienced, there were no changes in vasopressin and catecholamine concentrations nor in haemostatic function.
7. During the study, plasma aVP concentrations rose to levels previously shown to influence haemostatic function. This provides further support for the view that aVP has a secondary role as a mediator of acute changes in haemostasis, and during nausea contributes with adrenaline to an abrupt change in factor VIII and fibrinolytic activator activity.
Morphological and functional characteristics of isolated resistance vessels in advanced uraemia
Authors: Aalkjær C. , Pedersen E. B. , Danielsen H. , Fjeldborg O. , Jespersen B. , kjær T. , Sørensen S. S. , Mulvany M. J. 
Published: August 2015

1. In order to obtain direct information on the properties of the resistance vasculature of patients with advanced uraemia, a technique was developed to dissect out small arteries (internal diameter about 165 μm) from biopsies of subcutaneous fat.
2. Such arteries responded in a concentration-dependent manner to noradrenaline and angiotensin II, and the maximal force developed suggested that the vessels were fully viable.
3. Although the biopsies were normally taken during operations under general anaesthesia, biopsies taken under local anaesthesia also appeared to be fully viable, suggesting that this technique may prove useful as a general method for studying the intrinsic vascular properties of humans.
4. Biopsies were taken from 20 patients with uraemia, all of whom were treated with chronic intermittent dialysis, and 11 control subjects; up to three vessels were examined per biopsy.
5. The uraemic state was not associated with changes in vascular morphology, or in vascular reactivity or sensitivity to noradrenaline, angiotensin II, potassium or calcium. However, for the uraemic patients and for the controls there was a positive correlation between mean blood pressure and the ratio of vessel media thickness to lumen diameter, as well as a negative correlation between mean blood pressure and vessel active media stress.
6. The results suggest that uraemia treated with dialysis may not be associated with altered properties of the resistance vasculature. However, it appears that uraemic hypertension is associated with both morphological and functional abnormalities of the resistance vasculature.
Muscle morphology and enzymes in proximal and distal muscle groups of lower limb from patients with corticosteroid treated rheumatoid arthritis: the relationship to maximal isokinetic muscle strength
Authors: Danneskiold-Samsøe B. , Grimby G. 
Published: August 2015

1. Abnormal morphological and enzymatic patterns in the lateral vastus muscle have been found in women with corticosteroid treated rheumatoid arthritis. By means of biopsies from the lateral heads of right gastrocnemius muscles, the histology and enzyme activities were compared with those found in right vastus lateralis biopsies. The findings were correlated with isometric and isokinetic strength of the plantar flexors.
2. The relative occurrence of type I fibres in the gastrocnemius muscle was 46.4 ± 18.7 (sd) %, which is significantly higher than found in the vastus lateralis [35.7 ± 13.3 (sd) %] (P &lt; 0.03).
3. The relatively lower percentage of type II fibres in the gastrocnemius muscle was due to a relatively low percentage of type II A fibres [mean 27.9 ± 16.4 (sd) %] (P &lt; 0.05).
4. The area of type I fibres in the gastrocnemius muscle was 26.1 × 102 ± 10.0 (sd) μm2, which is 74% of the mean area for type I fibres found in the vastus lateralis (P &lt; 0.01).
5. The area of type II fibres in the gastrocnemius was 14.9 × 102 ± 7.1 (sd) μm2, which is 77% of the mean area for type II fibres found in the vastus lateralis.
6. The isokinetic muscle strength of the plantar flexors in corticosteroid treated patients with rheumatoid arthritis was reduced to less than 50% at all angular velocities when compared with healthy women. The same difference was found in the knee extensors.
7. Both type I and type II fibre areas correlated positively with the activity of β-hydroxyacyl-CoA dehydrogenase (r = 0.72, P &lt; 0.02; r = 0.77, P &lt; 0.01). The activity of the oxidative enzyme citric acid synthase (but not β-hydroxyacyl-CoA dehydrogenase) correlated positively with the isokinetic muscle strength of the plantar flexors at all the angular velocities (r = 0.75, P &lt; 0.01; r = 0.57, P &lt; 0.05).
8. The isokinetic strength as well as the type I and II fibre areas in the vastus lateralis biopsies correlated well with the same parameters in the gastrocnemius muscle (r approx. 0.70, P &lt; 0.001). The vastus lateralis and the gastrocnemius muscles had similar morphology in the same subjects. In the control subjects and in the patients a close correlation was found between the isokinetic strength of the knee extensors and the plantar flexors.
9. It is concluded that the corticosteroid effect on muscles seems to occur in both the proximal and distal skeletal muscles.
The influence of prednisone on the muscle morphology and muscle enzymes in patients with rheumatoid arthritis
Authors: Danneskiold-Samsøe B. , Grimby G. 
Published: August 2015

1. Thirty-five female patients, mean age 63 years, suffering from rheumatoid arthritis participated the study. Twenty patients had been on long-term low-dose corticosteroid treatment. Fifteen patients had never received corticosteroids. A control group of 15 age- and sex-matched healthy subjects was also studied.
2. Examination of muscle biopsies from the (right) vastus lateralis and measurements of isokinetic and isometric knee-extension muscle strength were performed in all subjects.
3. Rheumatoid arthritis patients treated with corticosteroid showed a low percentage of type I fibres, mean 35.7 (range 17–66) % compared with patients who did not receive corticosteroid (P &lt; 0.005). The latter group did not differ from the controls.
4. The muscle fibre areas also were affected in the corticosteroid treated rheumatoid patients. Type I and type II mean fibre areas were reduced by 32% and 50%, respectively, when compared with non-prednisone treated patients. The latter group did not differ from the controls in this respect.
5. A correlation was found between the isokinetic muscle strength of the knee extensors and the mean areas of type I and type II in patients treated with prednisone (r = 0.48, P &lt; 0.05 and r = 0.58, P &lt; 0.02 respectively). No such correlation was found when using isometric measurements of the knee extensors. A positive correlation was found in both groups of rheumatoid arthritis patients between the areas of the type I and type II fibres (r = 0.66–0.68, P &lt; 0.05–0.02).
6. It is concluded that the observed abnormal muscle morphology and low knee-extension capacity found in the corticosteroid treated patients is due to the treatment rather than to other factors, as there were no other differences between the two groups of patients.
Intracellular acid-base and electrolyte metabolism in skeletal muscle of patients with chronic obstructive lung disease and acute respiratory failure
Authors: Fiaccadori E. , Del Canale S. , Arduini U. , Antonucci C. , Coffrini E. , Vitali P. , Meley R. , Guariglia A. 
Published: August 2015

1. Quadriceps femoris muscle needle biopsies were performed in 21 patients with chronic obstructive lung disease (COLD) and acute respiratory failure (ARF) and in 21 age-matched healthy control subjects.
2. Muscle samples were analysed to obtain intracellular bicarbonate and pH values from total acid-labile carbon dioxide content. Muscle potassium, magnesium and sodium content were also determined, as well as water compartments.
3. Skeletal muscle of COLD patients with ARF showed intracellular acidosis and reduced potassium and magnesium content. Total muscle water increase was linked to extracellular water increment.
4. It was concluded that in COLD patients with ARF an overall derangement of skeletal muscle metabolism is present.
Non-esterified fatty acids may regulate human leucocyte sodium pump activity
Authors: Ng L. L. , Hockaday T. D. R. 
Published: August 2015

1. Human leucocyte sodium pump activity was studied in normal fasting subjects by measuring the ouabain-sensitive 22Na+ efflux rate constants.
2. This 22Na+ efflux rate constant was inversely related to the fasting plasma non-esterified fatty acid level (rs = −0.73, P &lt; 0.0001).
3. An oral glucose load (40 g/m2 surface area) led to an increase in the leucocyte ouabain-sensitive 22Na+ efflux rate constant after 2 h (1.97 ± 0.25 to 2.44 ± 0.19 h−1, P &lt; 0.0001, n = 11). There was a concomitant fall in the plasma non-esterified fatty acid level.
4. Incubation of leucocytes in vitro with 100 μmol/l linoleic acid inhibited the leucocyte ouabain-sensitive 22Na+ efflux rate constant (1.52 ± 0.27 vs 0.84 ± 0.24 h−1, P &lt; 0.001, n = 8).
5. The leucocyte Na+,K+-dependent adenosine triphosphatase (Na+,K+-ATPase) activity was inhibited in vitro by long chain non-esterified fatty acids, especially when unsaturated.
6. Non-esterified fatty acids may account for some of the Na+,K+-ATPase inhibitory activity of plasma.
Cerebrospinal fluid γ-aminobutyric acid levels in dogs with chronic portosystemic encephalopathy
Authors: Maddison J. E. , Yau D. , Stewart P. , Farrell G. C. 
Published: August 2015

1. Cerebrospinal fluid (CSF) γ-aminobutyric acid (GABA) levels were measured in a dog model of spontaneous chronic portosystemic encephalopathy.
2. Dogs with congenital portacaval shunts (intra- or extra-hepatic) develop neurological features of abnormal psychomotor behaviour and depressed consciousness that are consistent with the symptoms of chronic portosystemic encephalopathy in humans. In the five dogs studied, plasma ammonia was elevated, as was CSF tryptophan, both usual biochemical abnormalities in portosystemic encephalopathy.
3. CSF levels of GABA in five dogs with portosystemic encephalopathy (100 ± 13 pmol/ml) were not significantly different from those in five control dogs (96 ± 14 pmol/ml). CSF levels of GABA were not altered after ammonia infusion.
4. If enhanced GABA-ergic neurotransmission, due to influx of gut-derived GABA into the brain, is responsible for the pathophysiology of chronic portosystemic encephalopathy in this model, it is not reflected by increased levels of GABA in CSF.