bluuebunny/crossref_metadata_2025_split huggingface dataset:
The osmotic thresholds for thirst and vasopressin release are similar in healthy man
Authors: Thompson C. J. , Bland J. , Burd J. , Baylis P. H. 
Published: August 2015

1. The relationship between thirst perception and plasma osmolality was studied during hypertonic and physiological saline infusion in ten healthy volunteers.
2. Thirst perception was quantified using a linear visual analogue scale which volunteers marked at intervals during the infusion periods.
3. Infusion of hypertonic saline caused a steady rise in plasma osmolality together with a progressive linear increase in thirst perception and also plasma arginine vasopressin. No significant changes in thirst, plasma osmolality or plasma arginine vasopressin occurred during infusion of physiological saline.
4. Linear regression analysis of the results defined the functions. Thirst (cm) = 0.3 (plasma osmolality −281) (r = + 0.92, P &lt; 0.001) and plasma arginine vasopressin (pmol/l) = 0.4 (plasma osmolality −285) (r = + 0.96, P &lt; 0.001). The osmolar threshold for thirst onset thus defined (281 mosmol/kg) was much lower than in previous studies and similar to the theoretical osmolar threshold for vasopressin release (285 mosmol/kg).
5. We conclude that thirst perception rises in a progressive fashion throughout a wide range of plasma osmolality and that the osmolar threshold for thirst onset is similar to the theoretical osmolar threshold for vasopressin release.
6. The results are compatible with the concept of either a single osmoreceptor subserving both thirst and vasopressin release, or two osmoreceptors sharing similar functional characteristics.
Effect of dietary sodium chloride and posture on plasma immunoreactive atrial natriuretic peptide concentrations in man
Authors: Solomon L. R. , Atherton J. C. , Bobinski H. , Green R. 
Published: August 2015

1. The effect of changes of dietary sodium chloride intake and posture on plasma atrial natriuretic peptide concentration and renal function was studied in 11 normal human volunteers.
2. Plasma atrial natriuretic peptide concentration was higher in the upright posture on a high than it was on a medium or low salt diet. On the medium and high but not on the low salt diet the concentration increased significantly on adoption of the supine posture.
3. Creatinine, sodium, lithium and fractional lithium clearances, fractional distal sodium excretion and total distal water and sodium reabsorption, which were estimated by the lithium clearance technique, were significantly higher on the high than on the low salt diet. The medium salt intake gave intermediate values.
4. Heart rate while upright was significantly higher on the low than on either the medium or the high salt diets. Systolic blood pressure was unaffected by salt intake. Diastolic blood pressure in the supine position was significantly higher on the low than on the medium or high salt diets.
5. Both plasma noradrenaline concentrations and plasma renin activity were significantly higher on the low than on the high salt diet. Values on the medium salt intake were intermediate. Plasma concentrations of both hormones were higher in the upright than in the supine posture on all three salt intakes.
6. The data are consistent with the hypothesis that atrial natriuretic peptide contributes to the cardiovascular and renal adjustments to changes in dietary sodium chloride, and the possible role of the peptide is discussed.
Loss of spontaneous variability of fingertip anastomotic blood flow in diabetic autonomic neuropathy
Authors: Corcoran J. S. , Yudkin J. S. 
Published: August 2015

1. We have employed a thermal clearance probe to study fingertip blood flow, which comprises predominantly arteriovenous anastomotic flow.
2. In non-diabetic subjects there was a marked variability in resting fingertip blood flow which was of similar magnitude to that in diabetic subjects without autonomic neuropathy.
3. In 20 diabetic subjects with increasing severity of autonomic neuropathy there was a reduction of spontaneous variability in flow (r= 0.59, P &lt; 0.001), which was not related to differences in basal flow, in skin thickness or in age.
4. There was no relationship between maximal flow and severity of autonomic neuropathy (r= 0.08), although basal flow was decreased in subjects with moderate, but not those with severe, autonomic neuropathy (P &lt; 0.01 and P &gt; 0.4 compared with controls).
5. Our failure to find an increase in basal fingertip flow in autonomic neuropathy could imply that spontaneous variability of anastomic flow is lost before increased arteriovenous shunting becomes apparent, but it could result from the indirect heating employed in the study causing vasodilatation in subjects without neuropathy.
Arterial oxygen saturation and breathlessness in patients with chronic obstructive airways disease
Authors: Lane R. , Cockcroft A. , Adams L. , Guz A. 
Published: August 2015

1. Nine patients with chronic obstructive airways disease performed a 6 min self-paced walk (breathing air) on a treadmill and then identical (but operator-controlled) treadmill walks breathing either air or supplemental oxygen sufficient to just prevent arterial oxygen desaturation during the exercise.
2. During the exercises, ventilation was recorded and patients recorded their sensation of breathlessness on a visual analogue scale (VAS) every 30 s.
3. Breathing supplemental oxygen produced a small fall in mean exercise ventilation and a large and consistent reduction in mean exercise breathlessness. In seven patients the VAS scores were higher on air than with supplemental oxygen, at similar levels of ventilation. An analysis of co-variance, to control for reduction in ventilation, showed a decrease in mean breathlessness when breathing supplemental oxygen, significant at the 8% level.
4. The reduction in breathlessness produced by preventing exercise desaturation cannot be explained by the decrease in ventilation. This suggests that hypoxia may be a stimulus for breathlessness. The mechanism is unknown.
Bile acid binding to dietary casein: A study in vitro and in vivo
Authors: Lanzini A. , Fitzpatrick W. J. F. , Pigozzi M. G. , Northfield T. C. 
Published: August 2015

1. Studies were carried out in vitro using an ultracentrifugation method to quantify bile acid binding to the different components of a Lundh test meal, and to determine what factors influence bile acid binding to one of the components (casein). We validated the ultracentrifugation method by showing good agreement with the equilibrium dialysis method. Studies were carried out in vivo on jejunal aspirate from 10 ileal resection patients in order to determine whether bile acid binding to casein could be demonstrated, and whether this influenced aqueous-phase bile acid and fatty acid concentrations.
2. In vitro, the Lundh test meal was found to adsorb bile acid. The protein content of the meal (casein) alone accounted for this binding, which was abolished by use of casein hydrolysate. The binding to casein was a saturable process. Both binding affinity and binding capacity were significantly greater for taurocholate at pH 4.5 than at pH 6.5, and for dihydroxylated than for trihydroxylated bile acid, suggesting that hydrophobic bonding was involved.
3. In vivo, jejunal samples aspirated at pH &gt; 6 from 10 ileal resection patients showed 25% binding of bile acid to protein. On substitution of amino acids for casein, mean binding was reduced to 16% (P &lt; 0.05), residual binding being attributed to endogenous protein. This was associated with an increase in fatty acid solubilization from 28% to 60% (P &lt; 0.025).
4. These findings suggest that protein binding may have a critical effect on aqueous-phase bile acid and fatty acid concentrations in certain patients with a reduced total bile acid concentration as in ileectomy steatorrhoea, and in patients with defective lipolysis as in pancreatic insufficiency. This finding may provide an additional rationale for the use of elemental diets in severely ill patients with steatorrhoea.
Effect of changes in local skin temperature on postural vasoconstriction in man
Authors: Hassan Ahmad A. K. , Tooke J. E. 
Published: August 2015

1. The effects of locally induced alterations in skin temperature on the postural changes in skin blood flow of the foot were assessed in 38 healthy subjects in a constant-temperature environment (22 ± 0.5°C, mean ± sd).
2. Moderate local cooling and warming of the foot (26–36°C) was induced by blowing cold or hot air. Higher ranges of temperature (38–44°C) were achieved by a thermostatically controlled disc heater.
3. Skin blood flow was measured before and during each change in local skin temperature using a laser Doppler flowmeter with the foot maintained at heart level, and placed passively 50 cm below the heart. Blood flow was measured in two skin areas: (i) the dorsum of the foot, where arteriovenous anastomoses are absent, and (ii) the pulp of the big toe, where these anastomoses are relatively numerous.
4. It was found that within the physiological temperature range of 26–36°C the normal postural fall in foot skin blood flow was preserved, whereas it was markedly attenuated or totally abolished at higher temperatures (38–44°C). The pattern of response was quite similar in areas having or lacking arteriovenous anastomoses.
5. It is suggested that the failure of postural vasoconstriction observed at the higher skin temperatures might contribute to some of the problems of cardiovascular adaptations seen in a hot environment.
Antihypertensive and renal effects of cilazapril and their reversal by angiotensin in renovascular hypertensive rats
Authors: Ding Yu-An , Chang Shin-Tsu , Shieh Shyh-Ming , Huang Wann-Chu 
Published: August 2015

1. The antihypertensive and renal effects of cilazapril, a new angiotensin converting enzyme inhibitor, were evaluated in both two-kidney, one-clip Goldblatt hypertensive rats (n = 11) and normotensive rats (n = 6).
2. Intravenous infusion of cilazapril (1 mg/kg followed by 25 μg min−1 kg−1) caused significant reductions of blood pressure from 163 ± 3 to 122 ± 4 mmHg and from 157 ± 2 to 113 ± 3 mmHg in two separate groups of hypertensive rats and from 124 ± 1 to 105 ± 2 mmHg in normotensive rats. The hypotensive effect in terms of absolute value or percentage change was greater in hypertensive rats than in normotensive rats (41 ± 6 vs 20 ± 3 mmHg or 25 ± 4% vs 16 ± 2%, respectively).
3. Cilazapril increased glomerular filtration rate, urine flow, and absolute and fractional excretion rates of sodium and potassium in the non-clipped kidney of hypertensive rats. In contrast, the clipped kidney exhibited a depressed renal function during cilazapril infusion.
4. In normotensive rats, the hypotensive and enhanced renal function responses to cilazapril were much less than those of the non-clipped kidney of hypertensive rats.
5. Superimposed administration of either angiotensin II or angiotensin III during cilazapril infusion completely reversed the blood pressure and bilateral renal responses of cilazapril in both hypertensive and normotensive rats.
6. These results indicate that cilazapril reduces arterial pressure and enhances renal excretion mainly via inhibition of angiotensin II and angiotensin III formation.
Effect of hyperoxia and hypoxia on exercise-induced breathlessness in normal subjects
Authors: Chronos N. , Adams L. , Guz A. 
Published: August 2015

1. The subjective changes accompanying alterations in inspired oxygen concentration during heavy exercise have been investigated single blind, in normal subjects.
2. In particular, the intensity of the sensation of breathlessness was quantified using a visual analogue scale and changes were compared with those in objective ventilatory measures.
3. Eleven subjects performed three steady-state workload exercise tests on different days and 100% O2, 15% O2 or air were randomly administered for a fixed interval during each test.
4. Compared with air breathing, all subjects felt less breathless during 100% O2 breathing, and ten of them felt more breathless when inspiring 15% O2; these changes were reversed on return to air breathing.
5. During and after 100% O2, the time course of changes in breathlessness was similar to those for ear arterial oxygen saturation and minute ventilation such that it could be a secondary response to either. However, during and after inspiration of 15% O2, changes in breathlessness occurred relatively more quickly than those in ventilation, more closely reflecting changes in oxygen saturation; this suggests that hypoxia, per se, could contribute to the genesis of this sensation.
6. Individual variability in breathlessness responses to exercise and changes in inspired oxygen concentration did not correlate with objective ventilatory changes; neither were changes in breathlessness in the group particularly associated with changes in respiratory frequency or tidal volume.
Osmoregulation of thirst and vasopressin secretion in insulin-dependent diabetes mellitus
Authors: Thompson C. J. , Davis S. N. , Butler P. C. , Charlton J. A. , Baylis P. H. 
Published: August 2015

1. Osmotically stimulated thirst and vasopressin release were studied during infusions of hypertonic sodium chloride and hypertonic d-glucose in euglycaemic clamped diabetic patients and healthy controls.
2. Infusion of hypertonic sodium chloride caused similar elevations of plasma osmolality in diabetic patients (288.0 ± 1.0 to 304.1 ± 1.6 mosmol/kg, mean ± sem, P &lt; 0.001) and controls (288.6 ± 0.9 to 305.7 ± 0.6 mosmol/kg, P &lt; 0.001), accompanied by progressive increases in plasma vasopressin (diabetic patients, 0.9 ± 0.3 to 7.7 ± 1.5 pmol/l, P &lt; 0.001; controls 0.5 ± 0.1 to 6.5 ± 1.0 pmol/l, P &lt; 0.001) and thirst ratings (diabetic patients 1.0 ± 0.2 to 7.1 ± 0.5 cm, P &lt; 0.001; controls 1.8 ± 0.4 to 8.0 ± 0.5 cm, P &lt; 0.001) in both groups.
3. Drinking rapidly abolished thirst and vasopressin secretion before major changes in plasma osmolality occurred in both diabetic patients and healthy controls.
4. There were close and significant correlations between plasma vasopressin and plasma osmolality (diabetic patients, r = + 0.89, controls r = + 0.93) and between thirst and plasma osmolality (diabetic patients r = +0.95, controls r = +0.97) in both diabetic patients and healthy controls during hypertonic saline infusion.
5. Hypertonic d-glucose infusion caused similar elevations in blood glucose in diabetic patients (4.0 ± 0.2 to 20.1 ± 1.2 mmol/l, P &lt; 0.001) and healthy controls (4.3 ± 0.1 to 19.3 ± 1.2 mmol/l, P &lt; 0.001) but did not change plasma vasopressin or thirst ratings. There was no correlation between plasma osmolality and either thirst or plasma vasopressin during hypertonic d-glucose infusion.
6. The characteristics of osmoregulated thirst and vasopressin release are similar in health and diabetes mellitus. As hyperglycaemia was not dipsogenic, however, the thirst of poorly controlled diabetes mellitus may be due to hypovolaemia secondary to polyuria rather than hyperosmolality due to elevated blood glucose concentrations.
Prostaglandin precursor fatty acids in cirrhosis with ascites: Effect of linoleic acid infusion in functional renal failure
Authors: Rimola Antoni , Ginés Pere , Cusó Eulàlia , Camps Jordi , Gaya Joan , Arroyo Vincente , Rodés Joan 
Published: August 2015

1. Functional renal failure (FRF) in cirrhosis with ascites could be related to an inappropriately low renal prostaglandin (PG) production. To investigate whether the impaired renal PG synthesis in these patients is related to a PG precursor fatty acid deficiency, serum levels of linoleic and arachidonic acids and the urinary excretion of PGE2, 6-keto-PGF1α and thromboxane B2 (TxB2) were measured in 10 normal subjects, 17 non-azotaemic cirrhotic patients with ascites and 10 cirrhotic patients with ascites and FRF.
2. Serum linoleic acid levels were similar in the three groups studied. Both groups of cirrhotic patients showed lower arachidonic acid levels than normal subjects; however, non-azotaemic cirrhotic patients and patients with FRF did not differ in relation to serum arachidonic acid.
3. Non-azotaemic cirrhotic patients had higher urinary PGE2, 6-keto-PGF1α and TxB2 excretion than normal subjects and cirrhotic patients with FRF. Patients with FRF showed similar urinary PGE2 and TxB2 and lower urinary 6-keto-PGF1α than normal subjects. In all cirrhotic patients no significant correlation was found between serum linoleic and arachidonic acid levels and urinary PGs.
4. In seven patients with FRF an acute intravenous infusion of linoleic acid induced a marked increase in serum levels of this fatty acid. However, no increase in serum arachidonic acid levels and urinary PG excretion and no improvement in renal function was observed.
5. This study suggests that an arachidonic acid deficiency is present in cirrhotic patients with ascites but that this abnormality is not a major determinant of renal function and PG production in these patients. Acute intravenous administration of linoleic acid is not associated with any change in renal PG production and renal function in cirrhotic patients with FRF.
Detection of brown adipose tissue uncoupling protein mRNA in adult patients by a human genomic probe
Authors: Bouillaud Frédéric , Villarroya Francesc , Hentz Eliane , Raimbault Serge , Cassard Anne-Marie , Ricquier Daniel 
Published: August 2015

1. Studies on human brown adipose tissue require specific molecular probes. A human genomic library has been screened with a complementary DNA corresponding to the uncoupling protein (UCP) of rat brown adipose tissue mitochondria.
2. Two recombinant phages were isolated, carrying genomic sequences of human UCP. From them we have subcloned a 0.5 kilobase fragment. This fragment, H-Ucp-0.5, contained two intronic regions and two exonic regions. Exonic regions encoded a sequence of 84 amino acids which exhibited a strong homology with central domain at rat UCP. The organization of H-Ucp-0.5 was confirmed by SI mapping analysis.
3. A Southern analysis suggested that the gene is single type in the human, as it is in rodents.
4. In Northern analysis experiments, H-Ucp-0.5 detected a specific 1.8 kb mRNA in human brown adipose tissue obtained from six patients with phaeochromocytoma and from one patient with a hibernoma. This molecular probe is a new, sensitive and reliable tool with which to study human brown adipocytes.
Investigation of serum creatine kinase variability after muscle-damaging exercise
Authors: Clarkson Priscilla M. , Ebbeling Cara 
Published: August 2015

1. The present study examined if the presence of creatine kinase (CK) inhibitors might explain the large variability in blood levels of CK among subjects after exercise-induced muscle damage.
2. Twenty-four women performed an eccentric exercise with the forearm flexors and were then classified as no CK responders, low CK responders and high CK responders. High CK responders repeated the exercise two weeks later (bout two).
3. Sera from high CK responders were mixed with sera from no CK responders or low CK responders. Also, serum from high CK responders obtained after bout one was mixed with the same subject's serum from after bout two.
4. In all cases, the differences between the expected and observed CK activity for the mixes were within the expected variability for the assay.
5. Although CK inhibitors have been previously observed in sera from patients with muscle injury or disease, we were unable to demonstrate the presence of CK inhibitors in the sera from subjects who showed evidence of exercise-induced muscle damage.
Longitudinal study of renal prostaglandin excretion in cirrhotic rats: Relationship with the renin–aldosterone system
Authors: Solá Javier , Camps Jordi , Arroyo Vicente , Guarner Francisco , Gaya Joan , Rivera Francisca , Rodes Joan 
Published: August 2015

1. A cross-sectional study (protocol A) was performed in 19 rats with cirrhosis, induced by carbon tetrachloride (CCl4), and ascites and in 10 control animals to assess renal prostaglandin (PG) excretion in experimental cirrhosis. In an additional group of animals, including nine rats chronically exposed to CCl4 (CCl4 rats) and six control rats, a longitudinal study (protocol B) was performed to investigate the temporal relationship between changes in renal PG excretion, the renin—aldosterone system and renal function.
2. Urinary PG excretion was assessed by specific radioimmunoassay of PGE2, PGF2α, 6-keto-PGF1α and thromboxane (TX) B2 after extraction with octadecyl silica cartridges and h.p.l.c. purification. Recoveries for each prostanoid (61 ± 8% for PGE2, 64 ± 12% for PGF2α, 65 ±11% for 6-keto-PGF1α and 66 ±17% for TXB2) were determined in every sample by adding tritiated standards, and the final values were corrected according to the individual recoveries.
3. Cirrhotic rats with ascites in protocol A showed a significantly higher plasma renin and aldosterone concentrations and urinary excretion of 6-keto-PGF1α and TXB2 than did control animals. Urinary excretion of PGE2 and PGF2α, however, was significantly reduced in cirrhotic animals as compared with controls.
4. In CCl4 rats included in protocol B, there was a close chronological relationship between the activation of the renin-aldosterone system, as estimated by urinary aldosterone excretion, the onset of sodium retention and the increase in urinary excretion of 6-keto-PGF1α and TXB2. The urinary excretion of PGE2 and PGF2α in CCl4 rats was reduced throughout the study.
5. These results suggest that in rats with CCl4-induced cirrhosis, the increased renal production of prostacyclin and TXA2 is a consequence of the stimulation of endogenous vasoconstrictor systems. The impaired urinary excretion of PGE2 and PGF2α in CCl4 rats may be secondary to an inhibitory effect of CCl4 on PG synthesis in the renal tubules.
Muscle and bone in paraplegic patients, and the effect of functional electrical stimulation
Authors: Pacy P. J. , Hesp R. , Halliday D. A. , Katz D. , Cameron Gillian , Reeve J. 
Published: August 2015

1. Four paraplegic men volunteered for an exercise programme in which their paralysed quadriceps muscles were stimulated by means of computer-regulated electrical impulses applied through external electrodes. The first exercise regimen consisted of leg raising against a graded load, and during the second regimen exercise took the form of cycling on a modified bicycle ergometer. Each subject exercised five times weekly for 10 weeks during the first regimen and 32 weeks during the second regimen.
2. Whole-body protein turnover determined by l-[1-13C]leucine during feeding remained constant during both exercise regimens, when expressed either in terms of body weight or fat-free mass derived from measurements of total body potassium.
3. Quadriceps muscle protein synthetic rate increased during the study, from 0.0712 to 0.0985%/h (P &lt; 0.05), as did quadriceps muscle area assessed by computed tomography.
4. Bone mineral content for lumbar vertebrae was normal in all four patients, but for the femoral mid-shaft bone mineral content averaged only 66% of normal for three of the patients. Trabecular bone density in the distal tibia ranged from normal to 2% of normal for the men with the shortest and longest periods of disability, respectively. No changes in bone mineral content or bone density occurred during the exercise period.
Atrial natriuretic peptide vascular receptor: regulation of low-affinity binding by calcium
Authors: Morton J. J. , Beattie Elisabeth C. , Lyall Fiona 
Published: August 2015

1. In the presence of calcium, both high- [dissociation equilibrium constant (Kd) 5.8 × 10−11 mol/l] and low-(Kd 1.2 × 10−8 mol/l) affinity binding of atrial natriuretic peptide was detected on plasma membranes prepared from sodium-depleted rats.
2. In contrast, under calcium-free conditions only high-affinity binding (Kd 6.9 × 10−11 mol/l) was detected.
3. The requirement for calcium for low-affinity binding suggests a different mechanism of action than that for the high-affinity receptor.