Analysis of efficacy of antihypertensive drugs.
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Clonidine↗
Biomedical subjects
A Petrie
Publications and source records attributed to A Petrie.
Effect of orciprenaline on hypoxic pulmonary vasoconstriction in dogs.
The effect of orciprenaline on hypoxic pulmonary vasoconstriction and arterial oxygen tension (PaO2) was studied in 8 dogs by measuring the redistribution of blood flow in response to unilateral alveolar hypoxia. The distribution of blood flow was recorded continuously by measuring the radioactivity of the mixed expired gas from each lung during the continuous intravenous infusion of xenon-133. The hypoxic vasoconstrictor response was significantly depressed by an infusion of 1.0 micrograms/kg/min of orciprenaline but not by a dose of 0.1 micrograms/kg/min. PaO2 during unilateral hypoxia was significantly lower during the infusion of the high dose of orciprenaline than it was in the control periods before or after the infusion. A bolus dose of 0.5 mg significantly increased blood flow to a lung with established hypoxic vasoconstriction and also caused a significant reduction in PaO2. Since these effects were produced in the absence of airway pressure or pulmonary vascular pressure changes, it is concluded that orciprenaline may depress the hypoxic pulmonary vasoconstrictor response in dogs.
Animals↗
Changes in ionized calcium and other plasma constituents associated with cardiopulmonary bypass.
Plasma concentrations of calcium fractions, proteins, phosphate and magnesium were measured before, during and after cardiopulmonary bypass in 15 patients undergoing cardiac surgery. When calcium chloride was added to a pump priming solution which contained little or no blood, the concentrations of all calcium fractions were significantly greater after bypass than before, with a mean ionized calcium concentration of 1.52 mmol litre-1 plasma water, 30 min after completion of bypass. This iatrogenic hypercalcaemia was increased significantly by the administration of more than 10 mg kg-1 calcium chloride in the first 30 min after bypass. Other plasma constituents showed the dilutional effect of the pump prime during bypass and only the magnesium concentration failed to return towards normal values after operation.
Adolescent↗
Plasma clearance and renal excretion of erythrocyte cryoprotectant hydroxyethylated amylopectin.
The value of low molecular weight-hydroxyethylated amylopectin (cryo-HES) as an extracellular cryoprotectant has been demonstrated in vitro. It is important that details of the intravascular persistence and urinary excretion be determined to compare with data already available as other grades of HES and with data on transfusion of cryo-HES cryoprotected blood. Following a single 400 ml (14% solution) infusion in man, the intravascular clearance of cryo-HES was well described mathematically by the equation: y = 3.30+6.49e-0.15kappa. The plasma concentration of cryo-HES fell to half its peak value in approximately 9.6 h. Approximately 20% of the total infused cryo-HES was excreted in the urine during the first post-injection hour, and 50% by 72 h. The ESR was not altered significantly by the presence of this material. The present study indicates that cryo-HES is eliminated rapidly and may thus be safe for transfusion to recipients of frozen blood.
Adult↗
Prevalence of vibration-induced white finger in fluorspar mines in Weardale.
A combined epidemiological and clinical study of vibration-induced white finger (VWF) was carried out involving 115 men in four fluorspar mines. The overall prevalence of VWF was found to be 50% among 42 vibration-exposed subjects, while that of constitutional white finger (CWF) was 5-6% in all men studied. The VWF latent interval was 1-19 years with a mean of 5-6 years. An association was observed between the exposure time and VWF stages which included 18 men in Stage 0, three in the intermediate Stage of 0T/0N, five in Stage 2 and 16 in Stage 3; no men were seen at Stage 1. Among those with VWF in Stage 3, the index, middle and ring fingers were affected in both hands and the little fingers and thumbs were last to be involved. Clinically, on general examination, apart from vibration-induced white finger, the men in the 'vibration' group were not as healthy as those in the 'control' group. The circumference of the index fingers was not significantly different for the different groups. Neurological tests showed that the ridge test and, to a lesser extent, the two-point discrimination and the light touch tests, could be regarded as useful for the diagnosis of VWF.
Adolescent↗
Comment on "augmentation-reduction and pain experience" by Elton, et al.
Some of the troubling aspects in the work of Elton, et al. (1978) are detailed. Included are matters related to the measurement of pain tolerance, as well as that of reduction and augmentation.
Adolescent↗
Comparative clinical study of protein SAP (amyloid P component) and C-reactive protein in serum.
The serum concentration of protein SAP (amyloid P component) has been measured for the first time in a substantial series of normal individuals and patients with various diseases, and the results contrasted with the levels of the related protein C-reactive protein (CRP). The mean +/- s.d. concentration of protein SAP was 43 +/- 14 microgram/ml in seventy-six normal men, 33 +/- 10 microgram/ml in eighty-six normal women and 4 +/- 2 microgram/ml in thirty-six normal cord sera. Unlike CRP, whick is a major acute phase reactant, protein SAP was only slightly elevated in inflammatory and neoplastic diseases in which CRP was greatly increased. The level of protein SAP was significantly depressed in patients with hepatic disease, suggesting that its measurement might be of value in their management.
Amyloid↗
Analysis of possible factors influencing PaO2 and (PaO2--PaO2) in patients awaiting operation.
Data on arterial oxygen tension (PaO2) and alveolar-arterial PO2 difference (PAO2--PaO2) have been obtained from 337 patients awaiting elective surgery. Statistical analysis of these data has assessed both the individual and the combined influence of various factors on PaO2 and (PAO2-PaO2). The factors of importance in relation to PaO2 include age, smoking habits, body build and PAO2. In relation to (PAO2-PaO2) the significant factors include age, PaCO2, weight and smoking habits.
Adult↗
Comparison of levodopa with carbidopa or benserazide in parkinsonism.
The therapeutic efficacy and side-effects of two preparations of levodopa with extracerebral decarboxylase inhibitors have been compared in 19 patients with idiopathic parkinsonism in a blind randomised crossover trial. The mean daily dose of levodopa was 658 +/- 64 mg/day (mean +/- S.E.M.) when given together with carbidopa 66 mg/day and 605 +/- 59 mg/day when levodopa was combined with benserazide 151 mg/day. There was no significant difference between the treatment regimens either in beneficial effects on parkinsonian symptoms and signs or in the adverse effects of levodopa assessed by a clinical observer unaware of the treatment given. Of the 19 patients studied, 9 preferred the carbidopa preparation, 8 preferred the benserazide preparation, and 2 had no preference. It is concluded that there is no significant difference in therapeutic effects or adverse reactions between the two commercially available decarboxylase inhibitor-containing preparations. Central-nervous-system actions and side-effects depend on the daily dose of levodopa, regardless of the different ratios of decarboxylase inhibitors to levodopa.
Aged↗
A method for performing a calcium balance study in man and the interpretation of results.
Methods for the measurement of calcium in the diet, urine and faeces for the performance of a calcium balance study was described, along with experiments on analytical procedures including recovery values. A means of calculating the inherent "technical error" in such a balance is given, and a method for determining the significance of any change in a patient's balance is described. These are illustrated by worked examples of data from a patient suffering from Paget's disease and one with osteoporosis before and after treatment with calcitonin.
Calcium↗
Deterioration of glucose tolerance in hypertensive patients on prolonged diuretic treatment.
Glucose tolerance was investigated in 51 hypertensive patients before and after 1 and 6 years of treatment with oral diuretics. Glucose tolerance was unchanged after 1 year but had deteriorated significantly after 6 years' therapy. In a comparable group of 16 patients tested at similar intervals in which diuretic therapy had been given only for 3 of the 6 years there was no change in glucose tolerance, suggesting that prolonged oral treatment with thiazide diuretics is diabetogenic.
Administration, Oral↗
Pain during continuous nitrous oxide administration.
The continuous administration of nitrous oxide, in subjects who remain conscious, caused only a relatively small increase in the threshold of appreciation of pain, induced experimentally by tibial pressure and a hot wire applied to the thenar eminence. The threshold reached a maximum at 10 min. A concentration of 50% nitrous oxide caused only a marginally greater effect than 33%. In some subjects pain thresholds returned to control values during administration of the gas. In contrast, when a concentration of 50% nitrous oxide was approached in step changes of 7-10% over a period of 45 min, the effect on the pain threshold was more than doubled. It was concluded that, with respect to analgesia, adaptation of the nervous system to a constant concentration of nitrous oxide can occur in some subjects.
Analgesia↗
Proceedings: Factors influencing arterial oxygen tension and alveolar-arterial oxygen partial pressure difference in surgical patients.
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Humans↗
Idiopathic parkinsonism treated with bromocriptine.
The efficacy and toxicity of bromocriptine, a drug which simulates dopamine, have been studied in twenty-eight patients with idiopathic parkinsonism. A double-blind, within-patient comparison between maximum tolerated doses of bromocriptine (mean 46-9 mg daily) and placebo revealed a substantial and statistically significant therapeutic response to the active drug. Adverse reactions were dose dependent, reversible, and similar to those encountered with levodopa. While taking bromocriptine fourteen patients were able to stop levodopa (with or without carbidopa); in five patients the dose of levodopa was reduced by 54% (mean). Eight patients could not tolerate bromocriptine; one patient failed to comply with prescribed adjustments of dosage.
Aged↗
Tardive dyskinesia treated with pimozide.
We have investigated the action of pimozide in tardive dyskinesia induced by prolonged administration of phenothiazines. Improvement was recorded in a double blind study of 18 patients treated with maximum tolerated dosage (mean 18.8 mg/day) for 6 weeks. There was no deterioration in the therapeutic action of pimozide over this time. Parkinsonism and sedation were the main adverse effects. They were corrected by reduction of the dose of pimozide, but often recurred so that further adjustments of dosage were necessary. Our findings support the view that tardive dyskinesia is produced by a disturbance in the balance of central transmitters such that dopaminergic transmission is increased.
Aged↗
Clinical experience with use of ultrasound sphygmomanometer.
The performance of an ultrasound sphygmomanometer (Arteriosonde 1217) has been compared with that of the London School of Hygiene and Tropical Medicine and Hawksley sphygmomanometers. The Arteriosonde gave closely similar values of systolic blood pressure of the other instruments but diastolic blood pressure lay midway between phase 4 and phase 5 of the Korotkoff sounds. Observers using the Arteriosonde showed a significant preference for even terminal digits.
Blood Pressure Determination↗
Arterial blood pressure in patients with Parkinson's disease.
The casual arterial blood pressure of 411 patients with Parkinson's disease was compared with that of a representative sample of the general population. The patients were also divided into various sub-groups, and comparisons of blood pressure were made between them. The results provided no support for the widely held belief that blood pressure tends to be low in patients with Parkinson's disease.
Adult↗
Dopaminergic agonists in Parkinsonism.
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Aged↗