bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binding Sites for 125I-Labelled Endothelin-1 in the Kidneys: Differential Distribution in Rat, Pig and Man Demonstrated by Using Quantitative Autoradiography
Authors: Davenport Anthony P. , Nunez Derek J. , Brown Morris J. 
Published: August 2015

1. Quantitative receptor autoradiography in vitro has been used to determine the distribution and density of specific binding sites for 125I-labelled endothelin-1 in human, porcine and rat kidneys. Immunocytochemistry was used to visualize von Willebrand factor-positive endothelial cells in adjacent sections to those used for autoradiography.
2. High levels of specific binding were detected in the vasa recta and papilla of all three species with lower levels in the medulla and cortex.
3. A major difference between the species was observed within the glomeruli, where high levels of binding were found in the rat but no detectable binding sites in pig or man.
Diet-Induced Thermogenesis in Patients with Gastrointestinal Cancer Cachexia
Authors: Weston P. M. T. , King R. F. G. J. , Goode A. W. , Williams N. S. 
Published: August 2015

1. Indirect calorimetry has been used to measure resting energy expenditure (REE) and the thermogenic response to a test meal (diet-induced thermogenesis) in groups of weight-stable and weight-losing patients with gastrointestinal adenocarcinoma. Average daily intakes of energy and protein were computed from dietary assessment for the week before hospitalization. Results were compared with a control group of patients with benign gastrointestinal disease.
2. Weight-losing cancer patients had a significantly reduced mean total energy and protein intake.
3. There was no significant difference in REE between the groups when results were normalized in terms of metabolic body size (kJ/kg 0.75) and lean body mass (kJ/kg).
4. Diet-induced thermogenesis was reduced in weight-losing cancer patients.
5. It is suggested that the reduction of diet-induced thermogenesis in weight-losing cancer patients is another element of starvation adaptation, subsequent to their weight loss, and that altered thermogenesis does not contribute to the weight loss seen in cancer cachexia.
An Investigation of the Role of Possible Neural Mechanisms in Cholera Toxin-Induced Secretion in Rabbit Ileal Mucosa in Vitro
Authors: Moriarty K. J. , Higgs N. B. , Woodford M. , Turnberg L. A. 
Published: August 2015

1. Cholera toxin stimulates intestinal secretion in vitro by activation of mucosal adenylate cyclase. However, it has been proposed that cholera toxin promotes secretion in vivo mainly through an indirect mechanism involving enteric neural reflexes.
2. We examined this hypothesis further by studying the influence of neuronal blockade on cholera toxin-induced changes in fluid transport across rabbit ileum in vitro. Mucosa, stripped of muscle layers, was mounted in flux chambers and luminal application of crude cholera toxin (2 μg/ml) caused a delayed but sustained rise in the short-circuit current, electrical potential difference and Cl− secretion. Pretreatment with the nerve-blocking drug, tetrodotoxin (5 × 10−6 mol/l serosal side), failed to influence the secretory response to cholera toxin, and addition of tetrodotoxin at the peak response to cholera toxin also had no effect.
3. That tetrodotoxin could block neurally mediated secretagogues was confirmed by the demonstration that the electrical responses to neurotensin (10−7 mol/l and 10−8 mol/l) were blocked by tetrodotoxin (5 × 10−6 mol/l). Furthermore, the response to cholera toxin of segments of ileum, which included the myenteric, submucosal and mucosal nerve plexuses, was not inhibited by tetrodotoxin.
4. We conclude that cholera toxin-induced secretion in rabbit ileum in vitro is not mediated via a neurological mechanism.
Increased Plasma Atrial Natriuretic Factor and Reduced Plasma Renin in Patients with Poorly Controlled Diabetes Mellitus
Authors: Bell Gordon M. , Bernstein Richard K. , Laragh John H. , Atlas Steven A. , James Gary D. , Pecker Mark S. , Sealey Jean E. 
Published: August 2015

1. To investigate atrial natriuretic factor (ANF) and its relationship to the renin system in diabetes, we measured plasma immunoreactive ANF and plasma renin activity (PRA) in 27 non-ketotic diabetic patients without evidence of cardiac or overt renal disease, and compared them with 26 age- and sex-matched normal subjects.
2. Diabetic patients were divided prospectively into poor (PGC, n = 14) or moderate (MGC, n = 13) glycaemic control depending on their concurrent plasma glycohaemoglobin (HbA1) levels (&gt; 9% or &lt; 9%, respectively). Plasma ANF was elevated in PGC diabetic patients (15.7 ± 1.8 fmol/ml, mean ± sem) compared with MGC diabetics (9.9 ± 0.8 fmol/ml, P &lt; 0.001) and normal subjects (10.1 ± 1.3 fmol/ml, P &lt; 0.05).
3. In contrast, PRA was lower in the PGC diabetic patients (1.3 ± 0.3 pmol of angiotensin I h−1 ml−1) compared with the other groups (2.5 ± 0.5 and 2.1 ± 0.2 pmol of angiotensin I h−1 ml−1, P &lt; 0.05). Diabetic groups had proportionally more patients with high prorenin values (over 30 ng h−1 ml−1) than the normal group, but there was no difference between the diabetic groups.
4. Among the diabetic patients, ANF was directly related to HbA1 (r = 0.49, P &lt; 0.005) and urinary albumin excretion (r = 0.40, P &lt; 0.02), and was inversely related to PRA (r = −0.36, P &lt; 0.04) and plasma creatinine (r = −0.42, P &lt; 0.02).
5. Systolic blood pressure was greater in PGC diabetic patients [133 ± 5 mmHg (17.7 ± 0.7 kPa)] than in MGC diabetic patients [117 ± 4 (15.6 ± 0.5 kPa), P &lt; 0.05] and normal subjects [121 ± 3 (16.1 ± 0.4 kPa), P &lt; 0.05]. Diastolic pressure was not significantly different among the groups.
6. The directionally opposite changes in plasma ANF and plasma renin in PGC diabetic patients may reflect a normal response to expansion of intravascular volume. It remains to be established whether these changes are factors in the early renal dysfunction of diabetes mellitus.
Serum Digoxin-Like Substances in Pregnancy-Induced Hypertension
Authors: Poston L. , Morris J. F. , Wolfe C. D. , Hilton P. J. 
Published: August 2015

1. Endogenous digoxin-like immunoreactivity (EDLI) was measured in the serum of 85 normotensive pregnant (NTP) women and 77 women with pregnancy-induced hypertension (PIH) by a radioimmunoassay (New England Nuclear). All women were in the third trimester.
2. EDLI, which was undetectable in serum from nonpregnant women, was present in NTP and PIH and was significantly higher in PIH. EDLI correlated with gestational age in NTP, but not in PIH.
3. Ouabain-sensitive Na+ transport was estimated in normal peripheral blood leucocytes after incubation with sera from 50 NTP and 42 PIH women. Significant inhibition of active Na+ transport occurred only with the serum of hypertensive patients without proteinuria.
4. EDLI did not correlate with the effect of the sera on active Na+ transport. The radioimmunoassay therefore provides a poor index of Na+ transport inhibitory activity in PIH.
Altered Erythrocyte Cation Permeability in Familial Pseudohyperkalaemia
Authors: Dagher G. , Vantyghem M. C. , Doise B. , Lallau G. , Racadot A. , Lefebvre J. 
Published: August 2015

1. Erythrocyte cation transport pathways have been investigated in a family with pseudohyperkalaemia.
2. Ouabain- and bumetanide-resistant Na+ and K+ effluxes in three pseudohyperkalaemic patients were not different from those of control subjects when assessed at 37°C.
3. When the temperature was decreased to 20°C and 9°C, K+ passive permeability markedly increased and Na+ permeability remained unchanged in these patients. In contrast, in control subjects a reduction in temperature caused a marked reduction in Na+ and K+ passive permeability.
4. These findings could account for the marked increase in plasma K+ concentration observed at sub-physiological temperatures.
5. The Na+−K+ co-transport pathway was reduced in all members of the family, but the Na+−K+ pump was reduced in only two of them. These alterations were independent from the pseudohyperkalaemic state.
A Modified Method of Quantifying the Carotid Baroreceptor-Heart Rate Reflex in Man: The Effect of Age and Blood Pressure
Authors: Cowie M. R. , Rawles J. M. 
Published: August 2015

1. Carotid baroreceptor-heart rate sensitivity has been measured non-invasively by a modified neck-chamber method that utilizes all cardiac intervals recorded in 6 min during 84 respiratory cycles.
2. In a replication study in 10 subjects the mean baroreflex sensitivity was 5.52 ms/mmHg and the mean (sd) difference between determinations was 0.70 (0.74) ms/mmHg.
3. Baroreflex sensitivity was measured in 48 untreated subjects of mean age 43 (range 20–71) years with blood pressures ranging from 104 to 202 mmHg (13.9 to 26.9 kPa) systolic and 52 to 120 mmHg (6.9 to 16.0 kPa) diastolic [average 142/87 mmHg (18.9/11.6 kPa)]. Both systolic and diastolic pressures correlated with age (r = 0.53, P &lt; 0.001 and r = 0.44, P &lt; 0.01).
4. Baroreflex sensitivity determined throughout respiration was log-normally distributed with a median value of 2.24 ms/mmHg, which declined with age (r = −0.63, P &lt; 0.001).
5. After allowing for the effects of age, baroreflex sensitivity throughout respiration was not independently related to either systolic or diastolic blood pressure.
Carbidopa Does Not Affect the Renal Response to Atrial Natriuretic Factor in Man
Authors: Lewis Helen M. , Wilkins M. R. , Kendall M. J. , Lee M. R. 
Published: August 2015

1. The dependence of atrial natriuretic factor on renal dopamine for its renal effects in man was examined in 10 healthy volunteers using the dopa decarboxylase inhibitor carbidopa.
2. Each volunteer attended on two occasions, and received an infusion of atrial natriuretic factor (4 pmol min−1 kg−1) for 60 min after pretreatment with either placebo or carbidopa orally. These were administered in random, double-blind fashion.
3. A similar increase in plasma atrial natriuretic factor concentration was seen after atrial natriuretic factor infusion on both visits.
4. Infusion of atrial natriuretic factor produced a small unsustained rise in urinary dopamine excretion. This increase in urinary dopamine excretion was blocked by carbidopa with no effect on the natriuresis.
5. Urinary guanosine 3′:5′-cyclic monophosphate excretion increased in response to the atrial natriuretic factor infusion whether placebo or carbidopa was given. Guanosine 3′:5′-cyclic monophosphate, but not dopamine, may be a mediator of the renal response to atrial natriuretic factor in man.
Lithium Clearance in Chronic Nephropathy
Authors: Kamper A.-L. , Holstein-Rathlou N.-H. , Leyssac P. P. , Strandgaard S. 
Published: August 2015

1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function.
2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption of lithium or influence of osmotic diuresis.
3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min.
4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min.
5. Lithium clearance data were independent of whether renal disease was of primarily glomerular or tubular origin and, further, were not influenced by long-term conventional antihypertensive treatment.
6. It is concluded that, even with a reduced kidney function, the data are compatible with the suggestion that lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct). With more severe impairment the proximal tubule also becomes involved in the adjustment.
Relation between Plasma β-Endorphin and the Ventilatory Response to Hypercapnia in Humans
Authors: Levick M. P. , Lovelock M. , Smith R. , Saunders N. A. 
Published: August 2015

1. Endogenous opioids have been implicated in the control of breathing in neonates, but their role in ventilatory control in adults remains unclear.
2. We studied the relationship between circulating immunoreactive β-endorphin and the ventilatory and mouth occlusion pressure responses to hypercapnia in 12 healthy male subjects. In addition, we examined the effect of repetitive hypercapnia on plasma β-endorphin and Cortisol levels.
3. A weak but significant negative relationship between the ventilatory response to hypercapnia and basal plasma β-endorphin levels was observed (r = −0.35, P &lt; 0.01). A similar negative relationship was noted between mouth occlusion pressure response to hypercapnia and basal plasma β-endorphin levels (r = −0.36, P &lt; 0.01).
4. Repetitive hypercapnia prevented the fall in plasma Cortisol that occurred under control conditions (P &lt; 0.02) but had no effect on plasma β-endorphin.
5. We conclude that plasma β-endorphin may play a role in the central chemical control of breathing in man.
Does Residual Insulin Secretion (Assessed by C-Peptide Concentration) Affect Lipid and Lipoprotein Levels in Insulin-Dependent Diabetes Mellitus?
Authors: Winocour Peter H. , Durrington Paul N. , Ishola Monica , Gordon Chris , Jeacock Julie , Anderson David C. 
Published: August 2015

1. Residual endogenous insulin secretion can be assessed by the circulating C-peptide concentration and is present in up to 15% of subjects with established insulin-dependent diabetes mellitus (IDDM). Its role in lipid metabolism in IDDM is not clearly defined. We examined the relationships between serum lipid and lipoprotein concentrations and the response of circulating C-peptide to a test meal in 205 subjects with IDDM.
2. Lipid and lipoprotein levels and glycaemic control did not differ significantly between patients with undetectable, low or high C-peptide responses.
3. High density lipoprotein (HDL) cholesterol and its subfractions were inversely related to concentrations of serum triacylglycerols (P &lt; 0.01–0.001), but not to C-peptide or glycated haemoglobin (HbA,) levels. Levels of HbA, and triacylglycerols were correlated with one another (P &lt; 0.01). Analysis of variance revealed that differences in gender and triacylglycerol concentrations were the most important determinants of HDL and HDL2 cholesterol levels. C-peptide only exerted a weak effect on HDL2 cholesterol levels and no significant predictors of HDL3 cholesterol were found.
4. It is concluded that endogenous insulin secretion (assessed by C-peptide concentration) is relatively unimportant in modifying HDL metabolism in IDDM and that associated clinical features, in particular ambient hypertriglyceridaemia, are of greater importance.
Human Forearm Arteriovenous Differences of Carnitine, Short-Chain Acylcarnitine and Long-Chain Acylcarnitine
Authors: Bartlett Dr K. , Bhuiyan A. K. M. J. , Aynsley-Green A. , Butler P. C. , Alberti K. G. M. M. 
Published: August 2015

1. Forearm arterial and venous concentrations of free carnitine, short-chain acylcarnitine, long-chain acylcarnitine, glucose, lactate, pyruvate, alanine, non-esterified fatty acids, glycerol, 3-hydroxybutyrate and acetoacetate were measured in fasted adult subjects.
2. In all subjects there was net uptake of short-chain acylcarnitine, 3-hydroxybutyrate and acetoacetate and net release of free carnitine and non-esterified fatty acids. The arteriovenous differences of the other metabolites were not consistent.
3. These observations support the concept that short-chain acylcarnitine (largely acetylcarnitine) contributes to the flux of metabolic fuels from the liver to muscle in the fasted state, although to a limited extent in comparison with 3-hydroxybutyrate (&lt; 5% on a molar basis).
Effect of Ligustrazine on Pulmonary Vascular Changes Induced by Chronic Hypoxia in Rats
Authors: Cai Y. N. , Barer G. R. 
Published: August 2015

1. Acute and chronic effects on the pulmonary circulation of ligustrazine, a chemically identified and synthesized principle of a Chinese herb, were studied in rats. It dilated lung vessels and reversed hypoxic pulmonary vasoconstriction.
2. In rats kept 2 weeks in 10% O2 in a normobaric chamber and simultaneously treated with ligustrazine, right ventricular hypertrophy and muscularization of pulmonary arterioles were attenuated compared with saline-treated rats. Pulmonary artery pressure, measured in isolated lungs perfused at a constant flow rate, was also less in ligustrazine-treated rats.
3. In isolated blood-perfused lungs of chronically hypoxic and control rats, the relation between pressure and flow was measured during normoxia (ventilation with air plus 5% CO2), hypoxia (2% O2 plus 5% CO2) and after ligustrazine during continued hypoxia. Alveolar pressure was always greater than left atrial pressure; thus flow was determined by the pulmonary artery minus alveolar pressure difference.
4. Pressure/flow lines were measured during normoxia in four groups of rats: (1) control, saline-treated; (2) control, ligustrazine-treated; (3) chronically hypoxic, saline-treated; (4) chronically hypoxic, ligustrazine-treated. Both chronically hypoxic groups had steeper lines (higher resistance) than the control groups, which were similar in all respects. However, in chronically hypoxic rats, the extrapolated intercept of the line on the pressure axis, probably attributable to small newly muscularized arterioles in a state of tore, was much increased in the saline-treated group but did not differ from controls in the ligustrazine-treated group.
5. The proportion of muscularized small vessels in the four groups was: control, saline-treated 6.3 ± 1.0%, control, ligustrazine-treated 5.7 ± 0.6% (not significant), chronically hypoxic, saline-treated 27 ± 3.1%, chronically hypoxic, ligustrazine-treated 14.7 ± 2.1% (P &lt; 0.01). We attribute the change in the pressure/flow line in ligustrazine-treated hypoxic rats to this attenuation of new muscle growth.
6. After chronic ligustrazine treatment, its acute effect was undiminished.
Haemodynamic and Cerebrovascular Responses to Glycerol Infusion in Dogs
Authors: Chen Jiann-Liang , Wang Yeou-Chih , Wang Jia-Yi 
Published: August 2015

1. The response of cerebral blood vessels to hyperosmolar agents in vivo remains controversial, and little is known about the effect of glycerol on cerebral vessels. In this study we investigated the cerebrovascular response to intravenous administration of glycerol (1 g/kg, infused over 25 min) in dogs under pentobarbital anaesthesia.
2. Intracranial pressure, systemic arterial pressure, mean arterial blood pressure, serum osmolarity and packed cell volume were continuously monitored, and blood gases were checked frequently. Through a parietal cranial window, pial vessel diameter was measured by means of a surgical microscope and a video image-analyser.
3. Pial vessel diameter increased gradually with a maximum at 30 min after the beginning of glycerol infusion. The maximum increase in diameter in small (&lt; 100 μm) vessels was 14.3%, whereas that in large (&gt; 100 μm) vessels was 10.3%. There was only a slight increase (&lt; 4%) in pial vessel diameter in vehicle-infused animals. The intracranial pressure decreased drastically after glycerol infusion, whereas the mean arterial blood pressure remained constant. There were correlations between the rise in serum osmolarity, fall in packed cell volume and vasodilatation, indicating that glycerol caused vasodilatation accompanied by plasma volume expansion.
4. Our data suggest that glycerol produces cerebral vasodilatation, which might be beneficial in cerebral ischaemia and vasospasm, in addition to its intracranial pressure-reducing effect on normal or oedematous brain. The degree of vasodilatation was not sufficient to affect the predominant intracranial pressure drop resulting from cerebral dehydration.
Vasopressin Secretion in Diabetic Subjects with and without Autonomic Neuropathy: Responses to Osmotic and Postural Stimulation
Authors: Reid W. , Ewing D. J. , Lightman S. L. , Eadington D. , Williams T. D. M. , Roulston J. E. , Clarke B. F. 
Published: August 2015

1. The release of arginine vasopressin (AVP) after an osmotic stimulus and head-up tilt was assessed in diabetic subjects with and without autonomic neuropathy
2. Six diabetic subjects with (DAN +ve) and five without (DAN − ve) evidence of autonomic neuropathy and five normal subjects were infused with 5% (w/v) NaCl at a rate of 0.05 ml min−1 kg−1 body weight for 120 min. Blood pressure, heart rate and plasma AVP were measured over this period
3. Seven DAN +ve, six DAN −ve and six normal subjects were tilted head-up to 45° for 120 min. Blood pressure, heart rate and plasma AVP were measured during the study
4. Infusion of 5% (w/v) NaCl produced appropriate rises in plasma osmolality and plasma AVP levels which did not differ between the three groups, confirming the normal osmotic release of AVP in the diabetic subjects
5. During head-up tilt, there were no differences in AVP responses between the three groups, despite a major hypotensive stimulus in the DAN + ve group
6. We conclude that osmotic release of AVP is normal in diabetes, but that cardiovascular release of AVP is impaired in diabetic subjects with cardiovascular reflex evidence of autonomic neuropathy, reflecting an afferent defect.
Effects of Insulin on Human Adipose Tissue Metabolism in Vivo
Authors: Coppack S. W. , Frayn K. N. , Humphreys S. M. , Dhar H. , Hockaday T. D. R. 
Published: August 2015

1. The metabolic effects of insulin on human adipose tissue were studied by combining the euglycaemic clamp technique with measurement of arteriovenous differences across the subcutaneous adipose tissue of the anterior abdominal wall
2. Eight normal subjects were studied after an overnight fast, and for 120 min during infusion of insulin (mean arterialized plasma insulin 50–55 m-units/l)
3. During the insulin infusion, the arterialized and abdominal venous levels of both non-esterified fatty acids and glycerol fell, and the arteriovenous differences for the release of these substances narrowed. The fractional rate of re-esterification of fatty acids was around 20% in the fasting state and increased to almost 100% during hyper-insulinaemia
4. In the fasting state the uptake of glucose and 3-hydroxybutyrate by adipose tissue could account for only 20% of the oxygen uptake. During insulin infusion, adipose tissue glucose uptake increased and could account for more than 100% of oxygen uptake, implying storage of glucose
5. Net balances of different substrates across adipose tissue were examined by calculating fluxes in terms of μg-atoms of carbon. In the fasting state adipose tissue was in marked negative carbon balance (because of the export of non-esterified fatty acids); during insulin infusion it just reached ‘carbon balance’. These results were in contrast to those from a previous study of glucose ingestion, in which the adipose tissue showed marked positive carbon balance (net substrate deposition).