bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Metoprolol and Propranolol in Modification of Haemodynamic and Renin-Aldosterone Responses to Tilting in Humans
Authors: Viol G. W. , Smith E. K. M. , Fitzgerald J. D. 
Published: August 2015

1. Acute oral administration of metoprolol and propranolol to ten normal males resulted in equal reduction in heart rate both supine and after passive tilting to 60°.
2. Tilted systolic blood pressure was reduced by both agents but metoprolol alone reduced supine systolic blood pressure.
3. Tilted but not supine diastolic blood pressure was reduced by both agents.
4. Metoprolol and propranolol both reduced the rise in plasma renin activity induced by tilting.
5. No effect of tilting was observed on plasma aldosterone.
Differential Effects of Acute and Chronic β-Adrenoreceptor Blockade on Blood Pressure and the Renin—Angiotensin—Aldosterone System in Essential Hypertension
Authors: Kolloch R. , Stumpe K. O. , Vetter H. , Gramann W. , Krück F. 
Published: August 2015

1. Serial measurements of plasma renin activity (PRA), plasma aldosterone concentration (PA) and blood pressure were performed overnight in patients with borderline (group 1) and sustained essential hypertension (group 2) before and after acute and chronic administration of either propranolol or pindolol.
2. Group 1 patients exhibited a typical rhythm of recumbent PRA with low values before midnight and large increases early in the morning.
3. In contrast, no rhythm and very low PRA values were observed in patients of group 2. Blood pressure was higher in group 2 than in group 1. There was a significant correlation between the hyporeninaemic and hypotensive effect of either acute (r = 0·79) or chronic (r = 0·4) β-receptor blockade.
4. In group 1, after β-receptor blockade the day—night profile of renin was similar to that observed in group 2 before treatment. Thus, in this latter subgroup, low-renin profiles might reflect reduced β-adrenoreceptor activity.
5. Plasma aldosterone was lower in group 2 but appeared to be inappropriately high relative to renin.
6. The data suggest that in hypertensive patients classified according to their blood pressure and recumbent PRA profiles a significant relationship exists between changes in PRA and arterial pressure. Thus patients with high PRA respond better to treatment than patients with low renin. We conclude that in the patients studied sympathetic nervous system activity mainly determined renin values as well as anti-hypertensive effectiveness of the β-blocking drugs.
β-Receptor-Blockade Hypotension and the Central Nervous System
Authors: Lewis P. J. 
Published: August 2015

1. Intravenous infusion of propranolol (3·86 μmol h—1 kg—1) for 2 h lowered arterial pressure in the conscious rabbit whereas similar infusions of practolol (37·6 μmol h—1 kg—1) did not.
2. The fall in blood pressure produced by propranolol was accompanied by a decrease in splanchnic nerve activity. Practolol did not change splanchnic nerve activity.
3. A centrally mediated decrease in sympathetic nervous activity makes an important contribution to the hypotensive action of propranolol in the rabbit. This effect is not shown by practolol.
Within-Patient Comparisons between Different Anti-Hypertensive Drugs
Authors: Harvald B. 
Published: August 2015

1. By substituting one anti-hypertensive drug for the other in a panel of hypertensive patients equipotent doses have been determined.
2. Thus 40 mg of propranolol is equivalent to 4·5 mg of pindolol, 98 mg of practolol, 128 mg of alprenolol, 49 mg of metoprolol, 42 mg of tolamolol and 4·4 mg of timolol.
3. Bendorfluazide (10 mg) is eqivalent to 1·6 mg of bumetanide, 20 mg of chlorthalidone, 35 mg of mefruside and 3·5 mg of amiloride together with 35 mg of hydrochlorthiazide.
4. Methyldopa (250 mg) is equivalent to 6 0 mg of debrisoquine and 0·5 mg of St 600 (Boehringer), which is a clonidine-like substituted imidazoline.
The use of Minoxidil in the Treatment of Severe Essential Hypertension: A Report on 100 Patients
Authors: Jacomb R. G. , Brunnberg F. J. 
Published: August 2015

1. One hundred patients with severe essential hypertension have been treated with minoxidil for a mean period of 8·4 months in a study involving eleven European centres. Seventy-two males and twenty-eight females were included in the group; the mean age was 55 years and the initial supine systolic and diastolic pressures averaged 212 (range 150–270) and 125 (range 90–150) mmHg respectively.
2. Reduction of supine diastolic pressure to less than 100 mmHg occurred in 94% of patients within 4 weeks. After the average follow-up period of 8·4 months the mean pressures were 151/91 mmHg. Concomitant therapy with β-receptor-blocking agents and diuretics resulted in satisfactory control of heart rate and weight gain.
3. Side effects included increased hair growth, nausea, fatigue, rash and darkening of the skin. ECG showed mainly T-wave changes and echocardiographic examination indicated improved ventricular emptying.
Treatment of Severe and Moderate Hypertension with Minoxidil: Experience in Twenty-Eight Patients
Authors: Dunea G. , Mamdani B. , Mahurkar S. D. 
Published: August 2015

1. Twenty patients with severe or moderate hypertension were treated with minoxidil for 284 patient-months.
2. The blood pressure was controlled in all patients, including those refractory to maximal doses of conventional anti-hypertensive agents.
3. In patients with moderate hypertension control with minoxidil was achieved earlier and more easily than with hydrallazine.
4. Three patients developed secondary resistance and required addition of guanethidine or increased doses of diuretics.
5. Fluid retention and hypertrichosis were the main side effects with minoxidil.
Clinical and Haemodynamic Study of Minoxidil in Moderately Hypertensive Patients
Authors: Jensen H. Ærenlund , Rasmussen K. , Mosbæk N. 
Published: August 2015

1. We have evaluated the effectiveness and safety of minoxidil in moderately hypertensive out-patients. Eight patients were treated with hydrochlorothiazide and minoxidil for 5 months. The only female patient developed slight, reversible facial hair growth. In the other seven patients there was a moderate decrease in blood pressure. There were only minimal side-effects. Mild exertional tachycardia and a mean increase in body weight of 0·5 kg was found, but no oedema or signs of cardiac insufficiency were observed. No abnormalities were seen during routine blood tests.
2. This study shows that minoxidil combined with a diuretic may be successfully used in treating moderately hypertensive male patients.
Treatment of Hypertension in Middle-Aged Men: A Feasibility Study in a Community
Authors: Åberg H. , Hedstrand H. 
Published: August 2015

1. In a health examination survey of 2322 men, aged 49–50 years, the prevalence of hypertension was 7·5%. All men with a supine diastolic blood pressure ≥ 105 mmHg were invited to a hypertension clinic.
2. Two years' treatment in eighty-six men achieved a blood pressure reduction of 31/16 mmHg, which was maintained for a 4 years period and considered satisfactory in 80% of the subjects. Propranolol was used in more than 80% of the cases.
3. The study indicates that it is possible to obtain acceptable blood pressure control in the community.
Pharmacokinetic and Pharmacological Studies with Clonidine in Normal Subjects
Authors: Davies D. S. , Wing L. M. H. , Reid J. L. , Tippett P. , Dollery C. T. 
Published: August 2015

1. A highly specific and sensitive assay based on stable isotope dilution and mass fragmentography has been developed to measure clonidine in plasma.
2. Plasma half-lives of clonidine ranged from 6·9 to 9·4 h in five normotensive subjects.
3. Plasma clonidine concentration correlated with reduction in salivary flow and degree of sedation but not with change in blood pressure.
Haemodynamic and Endocrine Changes during Antihypertensive Treatment with Clonidine and its Derivative St 600
Authors: Kho T. L. , Zaal G. A. , Wester A. , De Leeuw P. W. , Birkenhäger W. H. 
Published: August 2015

1. The cardio-renal haemodynamic and endocrine effects of the anti-hypertensive agents 2-(2,6-dichlorophenylamine)-2-imidazoline hydrochloride (clonidine, St 155) and 2-(5-fluor-o-toluidine)-2-imidazoline hydrochloride (St 600) were investigated in twelve patients with essential hypertension.
2. The anti-hypertensive action of both compounds was similar and was accompanied by a reduction in heart rate and in cardiac output, total peripheral resistance being unchanged. There was no alteration in renal blood flow and glomerular filtration rate, and renal vascular resistance showed a significant decrease. Blood volume and plasma renin concentration did not change significantly. An inverse relation between changes in plasma volume and plasma aldosterone concentration was observed. In the face of similar reductions in blood pressure, no differences were observed between systemic and renal haemodynamic and endocrine responses after clonidine and St 600.
Characteristics and Prognosis for Women with Hypertension in a Community: Results of a Longitudinal Study in Göteborg, Sweden
Authors: Bengtsson C. , Lindquist O. 
Published: August 2015

1. During the years 1968–69 a population study of 1462 women aged 38–60 years was carried out in Göteborg, Sweden. A total of 126 women were classified as hypertensive.
2. Hypertensive women reported a history of albuminuria and hypertension during pregnancy more often than women in the general population. Albuminuria, alterations of the eye-ground vessels and ECG changes indicating left ventricular strain were more often found in hypertensive women. Hypertensive women were on average heavier.
3. The same population sample was re-studied 6 years later. Two of the 126 women classified as hypertensive had died during the 6 years interval since the first examination, both from myocardial infarction. The death rate was similar to the population sample as a whole.
Blood Pressure and its Spontaneous Variations in a Northern Italian Population
Authors: Ambrosio G. B. , Bugaro L. , Gabaldo S. , Pigato R. , Zamboni S. , Dal Palù C. 
Published: August 2015

1. Blood pressure has been measured in a random sample of 5852 subjects (both sexes, 20–64 years old). The prevalence of hypertension (blood pressure ≥ 160 mmHg and/or 95 mmHg; 150 mmHg and/or 90 mmHg under the age of 30 years) was 29·5%.
2. In a cohort of 972 detected hypertensive subjects, longitudinal changes (2 and 5 months after the initial examination) were evaluated. The phenomenon of regression toward the mean value was evident.
3. The implications of the variability of blood pressure in a community control programme of hypertension are discussed.
Reversed Diurnal Blood Pressure Rhythm in Hypertensive Pregnancies
Authors: Redman C. W. G. , Beilin L. J. , Bonnar J. 
Published: August 2015

1. Reversal of the normal diurnal blood pressure pattern has been demonstrated in women with severe hypertension and renal impairment in pregnancy (pre-eclampsia).
2. Maximum arterial pressure occurred at night in these women. The phenomenon was not due to hypotensive drug therapy or posture. Patients with uncomplicated essential hypertension in pregnancy retained a normal diurnal blood pressure pattern.
3. Nocturnal hypertension in pre-eclampsia is of theoretical interest and practical importance.
Biosynthesis of Folate Polyglutamate in the Rat with Different Tracers
Authors: Reed B. , Weir D. G. , Scott J. M. 
Published: August 2015

1. The recent suggestions that folate polyglutamate biosynthesis demonstrated in vivo with [3′5′9(n)-3H]folic acid is due to exchange and cannot be achieved with [2-14C]folic acid has been demonstrated to be untrue.
2. The compounds formed with both types of radioactive tracer have been shown to be folate polyglutamates from their elution position from precalibrated ion-exchange columns and their susceptibility to hydrolysis by a γ-carboxypeptidase (conjugase) from human sera.
3. By the use of the methods involving [2-14C]folic acid, reported by others to give only folate monoglutamates, we have been able to demonstrate clearly the presence of folate polyglutamates.
The Forms of Vitamin B12 on the Transcobalamins
Authors: MacDonald Caroline M. L. A. , Farquharson J. , Bessent R. G. , Adams J. F. 
Published: August 2015

1. The transcobalamins from normal serum were obtained in two fractions. One contained transcobalamin I and transcobalamin III: the other contained transcobalamin II. The forms of vitamin B12 in the two fractions were then examined.
2. Methylcobalamin and adenosylcobalamin were found in both fractions. Hydroxocobalamin was found in the fraction containing transcobalamin I and transcobalamin III. Cyanocobalamin was found in both fractions in two cases, in the transcobalamin III fraction only in one case and was absent in one case.
The Role of the False Neurotransmitter Octopamine in the Hypotension of Fulminant Hepatic Failure
Authors: Trewby P. N. , Chase R. A. , Davis M. , Williams R. 
Published: August 2015

1. An investigation was carried out into the mechanism of unexplained hypotension in patients with fulminant hepatic failure. The cardiac output and peripheral resistance were compared in normotensive and hypotensive patients. In addition, the serum concentration of the false neurotransmitter octopamine and the pressor response to noradrenaline, and to the indirectly acting sympathomimetic agent tyramine, were measured in hypotensive and normotensive patients with fulminant hepatic failure and in healthy subjects.
2. The cardiac output and the peripheral resistance were decreased in the hypotensive patients, and their mean heart rate was slower than in the normotensive patients. Although the serum octopamine concentration was significantly elevated in the patients compared with the control subjects, the highest octopamine concentrations were unexpectedly found in the normotensive patients and a significant positive correlation could be demonstrated between the resting blood pressure and the serum octopamine concentration. The pressor response to tyramine and noradrenaline were similar in the hypotensive patients, the normotensive patients and control subjects.
3. These results suggest that neither increased serum concentrations of the false neurotransmitter octopamine, nor end-organ insensitivity to released noradrenaline are responsible for the hypotension. A more likely explanation is toxic depression of the vasomotor centre. The opening of peripheral arteriovenous shunts, possibly as a result of endotoxaemia, might be an additional factor.
Functional and Structural Changes after Disuse of Human Muscle
Authors: Sargeant A. J. , Davies C. T. M. , Edwards R. H. T. , Maunder C. , Young A. 
Published: August 2015

1. Seven patients who had suffered unilateral leg fracture were studied after removal of immobilizing plaster casts.
2. Leg volume measured anthropometrically was reduced by 12% in the injured leg (5·68 ± 1·05 litres) compared with the uninjured (6·43 ± 0·87 litres). Associated with this loss was a similar reduction in the net maximum oxygen uptake achieved in one-leg cycling, from 1·89 ± 0·21 l/min in the uninjured leg to 1·57±0·18 l/min in the injured.
3. Measured by a percutaneous needle biopsy technique, a reduction of 42% was found in the cross-sectional area of the muscle fibres sampled from the vastus lateralis of the injured compared with the uninjured leg.
4. Staining for myosin adenosine triphosphatase activity showed that both type I and II fibres were affected, being reduced respectively from 3410 to 1840 μm2 and from 3810 to 2390 μm2 cross-sectional area.
5. Possible reasons and implications are discussed for the discrepancy between the magnitude of the difference observed in the gross measurement of leg function (maximum oxygen uptake) and structure (leg volume) as compared with the cellular level (cross-sectional fibre area).
Suppression of Plasma Renin Activity by Intravenous Infusion of Antidiuretic Hormone in Man
Authors: Hesse B. , Nielsen I. 
Published: August 2015

1. Ten patients on maintenance diuretic treatment received an intravenous infusion of antidiuretic hormone at a low rate for 1 h.
2. A gradual reduction in mean plasma renin activity was observed and this was significant at 60 min.
3. There was a significant correlation between the initial value and the extent of the fall in plasma renin activity. There was no consistent change in blood pressure, heart rate and blood volume.
4. The results point to an intrarenal site of action of antidiuretic hormone.
Erythrocyte Adenosine Triphosphate and 2,3-Diphosphoglycerate after Human Renal Transplantation: Dissociation from Hypophosphataemia
Authors: Barcenas C. G. , Paez P. , Uyeda K. , Peters P. C. , Hull A. R. 
Published: August 2015

1. Erythrocyte 2,3-diphosphoglycerate (2,3-DPG) and adenosine triphosphate (ATP) were determined in normal individuals, uraemic patients on chronic haemodialysis and patients who underwent renal transplantation, and correlated with plasma phosphate and arterial blood pH.
2. Significant increases in the 2,3-DPG and ATP content were found in the uraemic patients and these persisted after transplantation in spite of marked hypophosphataemia.
3. No correlation was established with plasma phosphate for either of the compounds but 2,3-DPG had a significant correlation with arterial blood pH.
4. Normal values for ATP and 2,3-DPG were observed in post-transplant patients with normal haematological values. The high amounts of erythrocyte 2,3-DPG and ATP in the early post-transplant period are independent of the circulating concentration of inorganic phosphate, and might represent the response of erythrocyte glycolysis to changing arterial blood pH.
Plasma Noradrenaline Concentrations in Experimental Renovascular Hypertension in the Rat
Authors: Dargie H. J. , Franklin S. S. , Reid J. L. 
Published: August 2015

1. Plasma noradrenaline concentrations and dopamine β-hydroxylase activity have been measured at various stages in the development of hypertension in the one-kidney Goldblatt rat (unilateral renal arterial constriction and contralateral nephrectomy).
2. Although plasma noradrenaline concentrations were significantly elevated from control values at 7, 14 and 28 days, plasma dopamine β-hydroxylase activity was not significantly different from control values except at 24 h.
3. These findings suggest that peripheral sympathetic activity is increased in the one-kidney Goldblatt model of experimental hypertension but that plasma dopamine β-hydroxylase activity is a poor index of this increase.
4. Both the rise in blood pressure and the rise in plasma noradrenaline concentrations were prevented by pretreatment with intracisternal 6-hydroxydopamine, suggesting that the increased sympathetic activity is at least in part centrally mediated.
Intrarenal Role of Angiotensin II in Controlling Sodium Excretion during Dehydration in Dogs
Authors: Trippodo N. C. , Hall J. E. , Lohmeier T. E. , Guyton A. C. 
Published: August 2015

1. The intrarenal role of angiotensin II in controlling sodium excretion was examined in anaesthetized, dehydrated dogs by infusing the angiotensin II antagonist Sar1-Ile8-angiotensin II directly into the renal artery. Comparisons were made with dehydrated dogs receiving only sodium chloride solution intrarenally.
2. Intrarenal angiotensin II blockade resulted in significant increases in urinary sodium excretion and urine flow rate.
3. The results indicate that during the high-renin state of dehydration endogenous angiotensin II has intrarenal effects which lead to salt and water retention.
Studies on the Kinetics of Unconjugated [14C]Bilirubin Metabolism in Normal Subjects and Patients with Compensated Cirrhosis
Authors: Owens D. , Jones E. A. , Carson E. R. 
Published: August 2015

1. The kinetics of unconjugated [14C]-bilirubin metabolism have been investigated and analysed in terms of a three-pool model in a group of seven normal subjects and in a group of eight cirrhotic patients who had appreciable impairment of liver cell function.
2. In the patients with cirrhosis, the plasma unconjugated bilirubin was either normal or only slightly increased but the metabolism of unconjugated bilirubin was deranged.
3. The mean volume of distribution, the mean 4 h retention, and the mean mass of the rapidly mixing pool were all significantly greater than in the normal subjects. In contrast, mean fractional clearance rate and mean estimated erythrocyte life-span were significantly less than in the normal subjects.
4. The mean fractional transfer rates and fluxes from pool 1 (rapidly mixing pool—‘plasma’) to pool 3 (‘extravascular’) and vice versa were significantly greater than the corresponding values in the normal subjects.
5. The results indicate that, in patients with compensated cirrhosis, the efficiency of the liver in extracting unconjugated bilirubin from plasma against a concentration gradient is impaired, even though the liver's capacity to conjugate bilirubin may be normal. As a consequence of the increased volume of distribution, the absolute hepatic clearance of unconjugated bilirubin is relatively well maintained.
The Assessment of Left Ventricular Ejection Fraction in Patients with Ischaemic Heart Disease by Contrast Ventriculography and Nuclear Angiography
Authors: Muir A. L. , Hannan W. J. , Brash H. M. , Baldwa V. , Miller H. C. , Ogilvie B. 
Published: August 2015

1. In 18 patients with ischaemic heart disease left ventricular ejection fraction, measured by two different nuclear angiographic methods, has been compared with ejection fraction measured by single-plane contrast angiography.
2. The first nuclear angiographic technique involves detection of variation in the radioactivity from the left ventricle during the initial passage of a bolus of 99Tcm-labelled human serum albumin injected intravenously; the second is our own modification of a ‘gated’ method, which accumulates the radioactivity detected during the continuing recirculation of the plasma bound radioisotope, so presenting an ‘averaged’ ventricular volume curve.
3. Ejection fraction, measured by the ‘bolus’ method, is lower than that measured either by contrast ventriculography or by the ‘gated’ method. This may be due to a damping effect.
4. Ejection fraction measured by the ‘gated’ method is well correlated with that measured by contrast ventriculography (r = 0·89).
5. Our modification of the ‘gated’ method, which presents the changes in ventricular volume throughout the cardiac cycle, without needing computer facilities, is a useful non-invasive means for assessment of left ventricular function.
Effects of Hexachlorobenzene Feeding and Iron Overload on Enzymes of Haem Biosynthesis and Cytochrome P450 in Rat Liver
Authors: Louw M. , Neethling A. C. , Percy V. A. , Carstens M. , Shanley B. C. 
Published: August 2015

1. The effect of hexachlorobenzene feeding on liver δ-aminolaevulinate synthase, uroporphyrinogen decarboxylase and cytochrome P450 was studied at various time-intervals in siderotic and non-siderotic rats.
2. In the non-siderotic group hexachlorobenzene feeding led to a progressive decrease in liver uroporphyrinogen decarboxylase activity, accompanied by a progressive increase in δ-aminolaevulinate synthase activity. Cytochrome P450 concentrations were above normal throughout but fell toward the end of the experiment.
3. Similar but more marked changes were found in the siderotic animals. The fall in uroporphyrinogen decarboxylase activity occurred earlier and was significantly greater in these animals, whereas the increase in δ-aminolaevulinate synthase activity was consistently larger. Liver cytochrome P450 concentration also rose but to a lesser extent than that in the non-siderotic rats.
4. Hexachlorobenzene-induced porphyria would seem to be attributable to inhibition or inactivation of hepatic uroporphyrinogen decarboxylase. Hepatic siderosis has a synergistic effect with hexachlorobenzene on this enzyme and may exert additional effects by promoting cytochrome P450 turnover.