bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Magnesium on Ion Transport in Short-Circuited Rabbit Terminal Ileum
Authors: Booth I. W. , Milla P. J. , Harries J. T. 
Published: August 2015

1. The effects of MgCl2 on the electrical characteristics and sodium and chloride transport in short-circuited rabbit terminal ileum in vitro were studied.
2. Increasing the magnesium concentration from a basal concentration of 1.1 mmol/l to either 2.5 or 10.3 mmol/l (mucosal or serosal addition) resulted in increases in the unidirectional flux of chloride from serosa to mucosa (JCl sm), short-circuit current (SCC) and transmucosal potential difference (p.d.).
3. Increasing the magnesium concentration from a low basal concentration (0.3 mmol/l) to 10.3 mmol/l (mucosal or serosal addition) abolished net sodium absorption and converted net chloride absorption into net secretion, as a result of a decrease in the unidirectional flux of sodium from mucosa to serosa (JNa ms), and increases in the unidirectional fluxes of sodium and chloride from serosa to mucosa (JNa sm and JCl sm). Increases in SCC and p.d. occurred after mucosal, but not serosal, addition of magnesium.
4. Incubation of stripped ileal mucosa with MgCl2 (10.3 mmol/l) did not result in increased mucosal concentrations of cAMP or cGMP.
5. These data suggest that at least part of the carthartic effect of magesium salts is likely to result from marked changes in ileal ion transport and provide a rational explanation for the watery diarrhoea commonly seen after the oral administration of magnesium salts to hypomagnesaemic patients.
Effect of An Intraluminal Food-Bulk on Low Calorie Induced Hyperbilirubinaemia
Authors: Ricci Giovanni L. , Ricci Riccardo R. 
Published: August 2015

1. To test the hypothesis that the presence of food in the intestine plays a role in the control of serum bilirubin levels, the effect of a 1674 kJ (400 kcal) diet, including non-absorbable material able to produce an intestinal bulk, was compared with the effect of caloric restriction alone.
2. In normal individuals (n = 10) the rise of plasma bilirubin was comparable after the two trials. In patients with Gilbert's syndrome (n = 18), bilirubin concentration rose to a much greater extent during the caloric restriction as compared with controls, and to a lesser extent (P&lt;0.001) after the bulky diet, as compared with caloric restriction alone in the same patient.
3. It is proposed that a factor originating from the intestine, perhaps a hormone, the release of which is dependent on the presence of food-bulk, plays a role in the control of hyperbilirubinaemia associated with caloric restriction.
Factor XII and Prekallikrein—Kallikrein—Kinin in the Cryoactivation of Human Plasma Prorenin
Authors: Brown C. F. , Osmond D. H. 
Published: August 2015

1. Cryoactivation of human plasma ‘prorenin’ was followed for 24 h at −4°C. Chromogenic assays were used to determine factor XII (FXII), FXIIa, prekallikrein and kallikrein in relation to the observed cold-induced increase in plasma renin activity (PRA). Bradykinin activity was also determined using the rat uterus bioassay.
2. PRA increased rapidly and became significantly higher after just 6 h of cryoactivation, by which time prekallikrein had almost disappeared, while kallikrein and kinin levels increased. In contrast, FXII did not change notably, but some FXIIa was indeed formed.
3. The bacteriostat neomycin sulphate did not affect the course of cryoactivation, but did block the dextran sulphate- and kaolin-induced activation of prekallikrein and FXII respectively, and was therefore omitted.
4. Thus cryoactivation of prorenin is accompanied by, and may depend upon, the activation of FXII and prekallikrein, supporting other evidence in favour of this hypothesis.
Muscarinic Cholinergic Receptors in Peripheral Lung Tissue of Normal Subjects and of Patients with Chronic Obstructive Lung Disease
Authors: Raaijmakers J. A. M. , Terpstra G. K. , Van Rozen A. J. , Witter A. , Kreukniet J. 
Published: August 2015

1. Muscarinic cholinergic receptors have been identified and characterized by radioligand binding studies in human peripheral lung tissue. The tissue was obtained at thoracotomy of 12 patients, of whom four had chronic obstructive lung disease.
2. The radioligand l-quinuclidinyl[phenyl-4-3H]benzilate (3H-QNB) was used to label the muscarinic cholinergic receptors. Binding was saturable, protein dependent and showed a high affinity and stereospecificity. Specific binding could be inhibited by agonists and antagonists; molar inhibition constants determined for the agents used were of the same order of magnitude as those reported for 3H-QNB inhibition in various tissues of laboratory animals. Inhibition experiments with agonists resulted in Hill slopes which were significantly different from unity, indicating multiple binding sites. The stable GTP analogue guanyl-5′-imidodiphosphate had no effect on the Hill slopes of agonists or antagonists.
3. The number of binding sites was significantly less in lung tissue from patients with chronic obstructive lung disease.
Effect of alcohol withdrawal on blood pressure, plasma renin activity, aldosterone, cortisol and dopamine β-hydroxylase
Authors: Bannan L. T. , Potter J. F. , Beevers D. G. , Saunders J. B. , Walters J. R. F. , Ingram M. C. 
Published: August 2015

1. Sixty-five alcoholic patients admitted for detoxification had blood pressure, withdrawal symptoms, plasma cortisol (PC) and plasma aldosteron (PA) levels, plasma renin activity (PRA), and serum dopamin β-hydroxylase (DBH) levels measured on the first and fourth days after admission.
2. On the morning after admission blood pressure was elevated (&gt;140/90) in 32 patients (49%) and was 160/95mmHg or more in 21 (32%). PRA was initially elevated in 41 patients, PA levels in 14, and 13 patients had raised PC levels. By the fourth day, blood pressure and bio-chemical measures had fallen significantly while urine volume and sodium output, low on admission, had increased significantly. On admission urinary metanephrine levels were raised in four out of the 31 patients who had them measured.
3. The height of both the systolic and diastolic blood pressures was significantly related to the severity of the alcohol. withdrawal symptoms. Of the biochemical parameters measured, PC level correlated with systolic but not diastolic pressure, and urinary volume was inversely correlated with the height of the diastolic pressure. No relationship was found between blood pressure and PRA or PA level.
4. The pressor effect of alcohol withdrawal could be due to sympathetic nervous system overactivity, or possibly to hypercortisolaemia. The first hypothesis seems more likely.
Further analysis of cell membrane changes in genetic hypertension in rats by diphenylhexatriene fluorescence polarization
Authors: Aracon-Birlouez I. , Montenay-Carestier T. , Devynck M. A. 
Published: August 2015

1. Fluorescence Dolarization of dbhenvlhexa-triene embedded in membranes was used as an index of ‘microviscosity’ in platelets and ervthro—cyte ghosts of spontaneously hypertensive rats of the Okamoto-Aoki strain (SHR), Wistar-Kyoto strain (WKY) and of the hypertension-prone and -resistant Sabra strains (SBH and SBN), and the original Sabra strain (SB).
2. Microviscosity was increased both in erythrocyte ghosts and platelet membranes of male but not female SHR rats compared with WKY rats and in hypertension-prone Sabra rats compared with the original Sabra rats.
3. Acute and chronic salt loading increased the microviscosity of platelet membranes in all strains of rats but had no effect on the erythrocyte membranes.
4. Microviscosities of vesicles made of lipids extracted from SHR and WKY erythrocyte ghosts were similar. This supports the hypothesis that membrane proteins play a major role in the differences in microviscosity observed in SHR rats.
Bile Salts, Hypotension and Obstructive Jaundice
Authors: Bomzon A. , Finberg J. P. M. , Tovbin D. , Naidu S. G. , Better O. S. 
Published: August 2015

1. We have examined the effects of bile duct ligation on vascular and extravascular smooth muscle responsiveness to noradrenaline and tyramine using isolated rat hindlimb perfusion, and portal vein and vas deferens preparations.
2. Bile duct ligation reduced the contractile responses to noradrenaline of vascular and extra-vascular smooth muscle.
3. Exposure of smooth muscle to some bile salts caused a reduction in contractility.
4. This effect was dependent upon bile salt type and concentration.
5. These studies in vitro suggest that the reduced total peripheral resistance and hypotension seen in obstructive jaundice cannot be explained by a spasmolytic effect of some of the bile salts on smooth muscle.
Within-Breath Modulation of the Triggering of Extrasystoles in Man
Authors: Patrick J. M. , Gibson Zoë , Hanley S. P. 
Published: August 2015

1. Sufficient isolated extrasystoles were recorded during a period of quiet breathing in nine patients to test the null hypothesis that there is no within-breath influence of respiration on the triggering of extrasystoles.
2. In five patients a highly significant respiratory modulation of the firing of extrasystoles was seen. The frequency distribution of extrasystoles during the respiratory cycle appeared to be approximately sinusoidal.
3. The phase relations varied with respiratory frequency, and the peak incidence occurred relatively later in the cycle when breaths were shorter: always at about 2 s after the start of inspiration.
4. An autonomic reflex mechanism, equivalent to that causing sinus arrhythmia, appears to be the most likely explanation.
Renal Excretion of Antidiuretic Hormone in Healthy Subjects and Patients with Renal Failure
Authors: Pruszczynski Wojciech , Caillens Henri , Drieu Luc , Moulonguet-Doleris Luc , Ardaillou Raymond 
Published: August 2015

1. Urinary clearance of antidiuretic hormone (ADH) has been measured under basal conditions and during intravenous administration of arginine vasopressin in ten healthy subjects, and only under basal conditions in 18 patients with chronic renal failure and seven patients with acute renal failure at the polyuric phase of the disease.
2. In healthy subjects studied under conditions of mild water diuresis, plasma concentration, urinary excretion rate, urinary clearance and fractional clearance of ADH were 3.3 ± 0.36 pg/ml, 25.2 ± 5.5 pg/min, 7.5 ± 1.2 ml/min and 6.4 ± 1.0% (means ± sem) respectively. When plasma ADH was raised to levels between 7 and 26 pg/ml during intravenous administration of the hormone, urinary excretion rate and urinary clearance of ADH increased. Tubular reabsorption of ADH did not reach a plateau but progressively increased in the range of plasma ADH studied.
3. In patients with chronic renal failure, plasma concentration, urinary excretion rate, urinary clearance and fractional clearance of ADH were 2.8 ± 0.19 pg/ml, 9.4 ± 2.0 pg/min, 3.4 ± 0.6 ml/min and 10.0 ± 2.9% (means ± sem) respectively. Urinary excretion rate and urinary clearance were significantly lower than in healthy subjects.
4. In patients with acute renal failure, plasma concentration, urinary excretion rate, urinary clearance and fractional clearance of ADH were 4.6 ± 0.47 pg/ml, 52.8 ± 15.8 pg/min, 9.5 ± 2.7 ml/min and 24.9 ± 4.4% (means ± sem) respectively. Urinary excretion rate and fractional clearance were higher than in healthy subjects and patients with chronic renal failure.
5. These results demonstrate that most of the filtered ADH is reabsorbed by the tubules. The reabsorptive capability is markedly diminished in patients with acute renal failure at the polyuric phase of the disease.
The Lipid-Lowering Effects of 3-Hydroxy-3-Methylglutaric Acid and Bile Acid Drainage in WHHL Rabbits
Authors: Van Niekerk J. L. M. , Hendriks Th. , Leuven J. A. Gevers , Havekes L. , De Boer H. H. M. 
Published: August 2015

1. The effect of 3-hydroxy-3-methylglutaric acid (HMG) on serum cholesterol levels was investigated in Watanabe heritable hyperlipidaemic (WHHL) rabbits.
2. Oral administration of HMG resulted in a reduction of serum cholesterol by 39%.
3. Bile acid drainage, by means of either cholestyramine medication or partial ileal bypass (PIB) surgery, also led to significant reductions in circulating cholesterol, by 35 and 59% respectively.
4. Intraperitoneal injection of HMG after PIB surgery further reduced serum cholesterol by 35%.
5. Fibroblasts from the WHHL rabbits did not show high-affinity binding, uptake or degradation of 125I-labelled low density lipoprotein (LDL).
6. The working mechanism of these lipid-lowering therapies in WHHL rabbits is discussed in relation to recent literature.
7. The significant reductions in circulating cholesterol induced by HMG warrant further investigation into the use of this compound in the management of familial hypercholesterolaemia.
Histamine and Secretory Otitis Media
Authors: Collins M. P. , Bakhshi K. , Wareham C. A. , Church M. K. 
Published: August 2015

1. Histamine, both free and cell associated, has been demonstrated in middle ear fluid from patients with secretory otitis media (SOM).
2. Histamine, mainly free in solution, has also been shown to be present in nasopharyngeal secretions taken from close to the Eustachian tube openings into the nasopharynx.
3. The adenoids from patients with middle ear effusion contained significantly (P&lt;0.05) more histamine than those with no effusion.
4. However, in preliminary experiments, we could demonstrate no differences in the histamine secretory response of adenoids from SOM and non-SOM patients to anti-immunoglobulin E (anti-IgE), house dust mite antigen and calcium ionophore A23187 in vitro.
5. These results support the hypothesis of an inflammatory basis for SOM.
Assessment of Smoking Behaviour and Ventilation with Cigarettes of Differing Nicotine Yields
Authors: McBride Melanie J. , Guyatt Andrew R. , Kirkham Andrew J. T. , Cumming Gordon 
Published: August 2015

1. Nine established cigarette smokers were each studied four times, smoking two identical cigarettes on each occasion. After an acclimatization study, they smoked one of three types of cigarettes, either their usual brand or one of two types of special low tar cigarettes. These latter both had tar yields of about 8 mg with nicotine yields of 0.55 (LN) and 0.90 (MN) mg respectively. The test order was randomized between individuals and before using the special cigarettes the subjects were given a pack to accustomize themselves.
2. While smoking each cigarette, magnetic tape recordings were made of puff rate, ventilation measured by respiratory inductive plethysmography (RIP) and nasal airflow measured with a modified oxygen cannula. The data were then processed digitally off-line.
3. Salivary nicotine and alveolar carbon monoxide levels were measured before and after smoking each cigarette, and the cigarette butt was analysed for nicotine.
4. While smoking behaviour varied considerably between the various subjects only small differences were seen between the different cigarette types in puff volume and duration and shape of the puff profile. Some changes in smoking behaviour occurred during the course of smoking a single cigarette.
5. Ventilatory patterns showed consistent inter-subject differences but there were no apparent variations due to the various cigarettes. Most subjects puffed during an expiration with the buccal cavity closed off, and then took a slower, deeper inspiration breathing through the mouth. Others, however, took puffs at any point in the respiratory cycle.
6. The different nicotine yields of the cigarettes produced marked changes in the butt and salivary nicotine measurements, but neither these, nor the changes in alveolar carbon monoxide, were closely related to ventilatory measurements. Possible explanations for these discrepancies are discussed.
Resistance to Methylprednisolone in Cultures of Blood Mononuclear Cells from Glucocorticoid-Resistant Asthmatic Patients
Authors: Poznansky Mark C. , Gordon Alastair C. H. , Douglas J. Graham , Krajewski Andrew S. , Wyllie Andrew H. , Grant Ian W. B. 
Published: August 2015

1. In order to investigate the cellular mechanism of glucocorticoid resistance in chronic asthma, peripheral blood mononuclear cells (MNC) from asthmatic patients were cultured in soft agar.
2. Cells from patients known to be clinically sensitive to glucocorticoid therapy did not differ significantly from those of clinically resistant patients in terms of their immunophenotype or the number of colonies generated by culture in the presence of phytohaemagglutinin.
3. The glucocorticoid methylprednisolone (MP) at low concentration (10 nmol/l) inhibited colony growth from cells of glucocorticoid-sensitive patients, whereas there was much less inhibition of colony growth from resistant patients' cells.
4. In a small prospective study inhibition of colony growth by methylprednisolone in vitro correlated with the subsequently determined sensitivity of the patients' asthma to glucocorticoid therapy.
5. Assessment in vitro of glucocorticoid sensitivity may help to predict which patients may be spared ineffectual glucocorticoid medication. The results raise the possibility that peripheral blood mononuclear cells may respond to glucocorticoid in a similar manner to cells involved in the pathogenesis of asthma.
Effect of Sodium Loading on the Urinary Excretion of Prostaglandins E2 and F2α in Rats with Hereditary Diabetes Insipidus (Brattleboro Rats)
Authors: Rathaus M. , Kariv N. , Shapira J. , Bernheim J. 
Published: August 2015

1. Current evidence suggests that the antidiuretic hormone (ADH) and changes in sodium balance influence renal prostaglandins (PGs). To separate these two mechanisms, the effect of sodium loading on the urinary excretion of PGE2 and PGF2α was studied in female Brattleboro rats with diabetes insipidus (DIHO) and compared with that in female, age matched, heterozygous Long Evans controls (LEHE).
2. Ten DIHO and ten LEHE rats had a normal sodium intake. In ten DIHO rats a 0.16% NaCl solution was supplied instead of drinking water for either 8 days (n = 5) or 14 days (n = 5). In two groups of LEHE rats, sodium loading was obtained with a 0.80% NaCl solution for the same study periods. Urine PGs were measured by radioimmunoassay in three 24 h urine collections for each rat.
3. Urine PGs were significantly increased in the 8 day loaded but not in the 14 day loaded LEHE rats. In DIHO rats, a non-significant increase in both PGE2 and PGF2α was present after 8 days of sodium loading, while PGE2 and the E/F ratio were decreased after 14 days of salt loading.
4. The findings suggest that the natriuresis induced by sodium loading in the rat may be mediated in part by increased production of PGs. In addition, it seems that ADH plays a role in this response.
Pharmacokinetics of Synthetic Human Parathyroid Hormone 1-34 in man Measured by Cytochemical Bioassay and Radioimmunoassay
Authors: Kent G. N. , Loveridge N. , Reeve J. , Zanelli Joan M. 
Published: August 2015

1. Synthetic human parathyroid hormone (hPTH) 1-34 was given by intravenous injection to two healthy men. The time course of its appearance in and disappearance from the plasma was monitored both by cytochemical bioassay and by a specific radioimmunoassay (RIA) system.
2. Immunoreactive N-region parathyroid hormone (iPTH) reached peak concentrations in plasma at 2 min after injection, whereas peak concentrations of biologically active parathyroid hormone (bioPTH) were delayed until 4-6 min. Bioassayable PTH-like activity then disappeared from the plasma (mean transit times 5.8 and 8.6 min), approximately twice as fast as immuno-reactivity.
3. After separate subcutaneous administrations, a calculated 22-37% of administered hPTH 1-34 was subsequently detected in the plasma, by both assay systems.
4. It was not possible to explain fully the non-parallel appearances of bio- and immuno-reactivities in the plasma after intravenous injection nor the non-parallel disappearances after both intravenous and subcutaneous injections on the basis of the present data. It seems likely, however, that in the process of biological degradation the immunoreactive locus is inactivated by a different reaction from that which destroys bioactivity.
5. To investigate these activity dissociations further will require the application of microfractionation procedures in conjunction with both types of assay system.
Cardiovascular Properties of Metkephamid, a δ Opioid Receptor Agonist, in Man
Authors: Pasanisi Fabrizio , Sloan Lesley , Rubin Peter C. 
Published: August 2015

1. Opioid receptors exist in at least three forms: μ, δ and κ. Agonists at μ receptors produce orthostatic hypotension in man by a mechanism involving a reduction in baroreflex sensitivity. We describe here the cardiovascular properties of metkephamid, a relatively selective δ opioid receptor agonist.
2. Blood pressure, heart rate and plasma noradrenaline concentration were measured over a 7 h period in eight normal young male volunteers in the supine position and after 70° 5 min head-up tilt, after receiving metkephamid (50 mg intramuscularly) or placebo.
3. Metkephamid increased heart rate in the supine position with no change in blood pressure or plasma noradrenaline concentration. This was accompanied by symptoms consistent with an anti-muscarinic anticholinergic effect.
4. Head-up tilt resulted in substantial hypotension after metkephamid with an attenuated change in heart rate and no increase in noradrenaline concentration.
5. We conclude that δ as well as μ opioid receptor agonists can produce orthostatic hypotension with attenuation of heart rate response. Metkephamid possesses anticholinergic properties not seen with μ receptor agonists, suggesting a possible role of δ opioid receptors in cholinergic activity.
Dopamine reduces aldosterone and 18-hydroxycorticosterone response to angiotensin II in patients with essential low-renin hypertension and idiopathic hyperaldosteronism
Authors: Witzgall Helmut , Lorenz Reinhard , Werder Klaus Von , Weber Peter C. 
Published: August 2015

1. Plasma aldosterone, 18-hydroxycorticosterone (18-OH-B), 18-hydroxydeoxycorticosterone (18-OH-DOC), corticosterone, cortisol and prolactin levels were determined during an angiotensin II infusion at increasing rates both with and without a simultaneous infusion of dopamine in seven normotensive subjects, in ten patients with essential hypertension, and in ten patients with primary aldosteronism. In a second set of experiments, maximum increases of these plasma levels were determined after metoclopramide (10 mg intravenously) in all subgroups.
2. As compared with the other groups, an exaggerated angiotensin II-induced response of plasma aldosterone and 18-OH-B levels was observed in the five patients with low-renin essential hypertension (LREH) and in five patients with idiopathic hyperaldosteronism (IHA).
3. Dopamine reduced the maximal increase of aldosterone and of 18-OH-B after angiotensin II to 259 ± 48 (sem) pg/ml and 511 ± 152 pg/ml repectively in LREH (without dopamine: 515 ± 74 and 908 ± 201 respectively; P&lt;0.05), and to 466 ± 197 and 741 ± 212 in IHA (without dopamine: 766 ± 193 and 1264 ± 337 respectively; P&lt;0.05).
4. The maximal increases of plasma aldosterone, 18-OH-B, and prolactin after metoclopramide (10 mg intravenously) were higher (P&lt;0.01) in patients with LREH and in patients with primary aldosteronism. Plasma levels of 18-OH-DOC, corticosterone and cortisol were not affected by the stimuli applied.
5. The exaggerated response to metoclopramide as well as to angiotensin II and its reversion only by pharmacological doses of dopamine are consistent with an increased but ineffective dopamine inhibition of aldosterone and 18-OH-B in LREH and IHA.