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Biomedical subjects

P Ebden

Publications and source records attributed to P Ebden.

31 records · Page 2Linked to original sources
PubMed1987

The effect of cigarette withdrawal on asthmatics who smoke.

Fourteen asthmatics volunteered to stop smoking. Seven managed to stop for only 24 h and seven for 1 week. There was a significant increase in peak flow and specific airways conductance as early as the first 24 h of abstention, while after 7 days of abstention there was a further increase in peak flow and specific airways conductance and a reduction in bronchial responsiveness to histamine. Two subjects felt that their symptoms were worse while abstaining and one of these showed an increase in bronchial responsiveness. After abstention for 1 week, four of the seven subjects recorded an improvement in symptoms. Asthmatics who smoke should be encouraged to stop. Despite an improvement in symptoms and objective measurements, asthmatics may find it difficult to stop smoking and will need considerable help and encouragement if they are to succeed.

Adult↗
PubMed1986

Bone tuberculosis: results and experience in Leicestershire.

Management of tuberculosis falls to the thoracic physician and includes extrapulmonary sites. We have conducted a survey of notification of bone tuberculosis in Leicestershire from 1978 to 1983 inclusive. Eighty-one cases were notified, 75 were traced and 69 confirmed tuberculosis (mean age 40.2 years, 39 male, 54 from the Indian sub-continent (ISC)). Mean length of symptoms was 8.4 months, the commonest being pain and swelling. The diagnosis was established by evidence of bone involvement plus at least one of the following: positive Heaf test (54/56), positive culture at bone sites for Mycobacterium tuberculosis (45/47), or suggestive histology (30/34). There were no resistant organisms. Chemotherapy (mean duration 16.2 months) was well tolerated. Spine was the site most often involved (37 patients, 34 ISC), with abscess formation common (17 patients). Four who presented with spinal cord compression received a mean of 8 months' bed rest, three required decompression and one died. No patient developed new neurological signs on treatment. Fourteen others received an average of 2.3 months' bed rest. In this predominantly ISC immigrant population, spinal tuberculosis is common but does not progress to cord compression on treatment. For those without cord compression the course and outcome were similar whether or not they were treated with bed rest.

Adolescent↗
PubMed1986

The disposition of theophylline in blood in chronic obstructive lung disease.

In 42 subjects with chronic obstructive lung disease receiving chronic oral theophylline therapy, the venous whole blood theophylline concentration was closely related to the total plasma theophylline concentrations (r = 0.976, p less than 0.001). The blood/plasma concentration ratio was 0.85 +/- 0.13 and was not related to the haematocrit or the free fraction of theophylline in plasma. The red blood cell theophylline concentration was closely related and numerically similar to the free plasma concentration. This indicates that the free plasma concentration is the most important determinant of red blood cell concentration, and that binding of drug by red blood cells or active uptake into erythrocytes is unlikely to occur. Whole blood concentration can be used to predict plasma theophylline concentration in subjects with obstructive lung disease in situations where preparation of plasma is inconvenient. The therapeutic range for whole blood concentration is approximately 8.5-17 mg/L.

Adolescent↗
PubMed1986

Comparison of two high dose corticosteroid aerosol treatments, beclomethasone dipropionate (1500 micrograms/day) and budesonide (1600 micrograms/day), for chronic asthma.

Twenty eight patients with chronic asthma took part in a double blind single crossover controlled trial of inhaled budesonide and inhaled beclomethasone dipropionate, using high doses of 1600 micrograms and 1500 micrograms daily respectively. Both drugs were administered by pressurised aerosol inhaler; the inhaler containing budesonide and its matching placebo were fitted with a collapsible spacer device. There was no significant difference in the control of asthma during the two six week treatment periods. There was no significant difference in FEV1 and forced vital capacity after four and six weeks of treatment or in mean morning and evening peak expiratory flow rates for the last 21 days of treatment. There was a small but statistically significant reduction in the daytime wheeze score while they were taking high dose budesonide but there was no difference for daytime activity, cough, and night symptoms. The mean basal cortisol concentrations were significantly lower after six weeks of high dose treatment than before treatment (budesonide p less than 0.01, beclomethasone p less than 0.05). There was no difference between mean basal cortisol values after six weeks of high dose treatment, and there was no effect on the rise of cortisol obtained after a short tetracosactrin test. High dose inhaled corticosteroids produced few side effects and were well tolerated.

Adult↗
PubMed1985

Relationship between saliva and free and total plasma theophylline concentrations in patients with chronic airflow obstruction.

Total plasma and mixed stimulated saliva theophylline concentrations (by high performance liquid chromatography) and free plasma theophylline concentrations (by equilibrium dialysis) were measured in simultaneously collected samples from 32 outpatients receiving chronic oral theophylline treatment, who had received the drug at least two hours before sampling. There was a close relationship between saliva and total plasma theophylline concentration and between total saliva and free plasma concentration. The mean saliva to total plasma drug concentration ratio was 0.69 (SE 0.09) and the mean difference between paired saliva and free plasma concentration was 0.65 (0.17) microgram/ml. It is concluded that stimulated mixed saliva provides a simple, non-invasive method of assessing total (and free) plasma theophylline concentrations during chronic oral treatment. The therapeutic range for saliva, corresponding to the generally accepted total plasma concentration range (10-20 micrograms/ml), is approximately 7-14 micrograms/ml.

Adult↗
PubMed1985

Association between rise in antibodies and increase in airway sensitivity after intramuscular injection of killed influenza virus in asthmatic patients.

Nineteen stable asthmatic patients were given killed influenza virus intramuscularly. In 9 patients who developed a fourfold or greater rise in haemagglutination antibodies, an increase in airway sensitivity to histamine was demonstrated 48 h later. There was no significant change in histamine sensitivity in those patients who failed to develop a fourfold rise in haemagglutination antibodies. The increased histamine sensitivity was not associated with a deterioration in asthma symptoms, peak expiratory flow, nor an increase in bronchodilator requirements.

Adolescent↗
PubMed1984

Comparison of the absorption and metabolism of sulphasalazine and acrylic-coated 5-amino salicylic acid in normal subjects and patients with colitis.

Serum levels of 5-amino salicylic acid ( 5ASA ) and acetyl 5ASA have been measured in volunteers after ingestion of sulphasalazine (6 g) and compared with levels after an equivalent dose of acrylic coated 5ASA (2.4 g). The serum levels of both 5ASA and acetyl 5ASA were similar after each preparation apart from an early peak of 5ASA following acrylic coated 5ASA . Serum and urinary levels for 5ASA and acetyl 5ASA have been measured in colitic patients following equivalent doses of sulphasalazine and acrylic coated 5ASA . Serum levels were similar; 25% of the calculated ingested 5ASA was excreted in the urine after sulphasalazine compared with 20% following acrylic coated 5ASA .

Adult↗
PubMed1984

Free and total plasma theophylline concentrations in chronic airflow obstruction.

It has been suggested that the variability in clinical response between individuals at any given total plasma theophylline concentration may be related to interpatient variability in theophylline plasma protein binding. We therefore measured the plasma protein binding of theophylline in plasma from 39 outpatients with chronic airflow obstruction who were receiving long term oral theophylline treatment. The protein binding was measured at 37 degrees C and pH 7.4 by equilibrium dialysis. Total plasma theophylline concentration was measured by high performance liquid chromatography and the free concentration calculated by multiplying total concentration by the free (unbound) fraction. The total plasma theophylline concentration varied from 0.7 to 22.0 micrograms/ml, mean 10.6 (SD 5.3) micrograms/ml (3.9-121 mumol/l, mean 58.3 (29.2) mumol/l). The free fraction of theophylline varied only from 0.58 to 0.69 (mean 0.626 (0.024] microgram/ml and was not related to the total concentration (r = -0.236, n = 39, p greater than 0.05). There was a very close relationship between free and total plasma concentrations (r = 0.996, n = 39, p less than 0.001). It is concluded that there is little variability in plasma protein binding of theophylline in patients with chronic airflow obstruction. Other factors appear to be responsible for variability between individuals in the response to a given total plasma theophylline concentration.

Adolescent↗
PubMed1973

Effect on respiration of changes in the form of the naturally occurring oscillation in arterial pH.

We have previously shorn that the respiratory control system in the cat has the requisite sensitivity and speed to respond to changes in arterial pH which are equal to, or smaller than, the normal fluctuations in pH with respiration. A respiratory response was only observed when the changes in pH were produced by alterations in PCO2 and not when they were induced by non-gaseous acids. We describe now the respiratory effect produced by various procedures which modify or abolish the naturally occurring arterial pH oscillations before they reach the peripheral chemoreceptors. The pH oscillations were abolished by a mixing chamber, whilst their phase relationship to respiration was altered by delay coils; by presenting a moving plastic surface to the arterial blood stream it was possible to distort the shape of the oscillations without increasing the transport lag between lung and peripheral chemoreceptors. All manoeuvres produced a brief period of respiratory stimulation which was greater than could occur by chance. We were particularly concerned in these experiments with the possibility of artefacts in our experimental design. We feel that we have excluded respiratory effects due to changes in arterial pressure, blood temperature and mean pH. We are less confident that we have excluded changes in ventilation resulting from the release of a substance (or substances) from the contact of blood with plastic or glass surfaces. This problem is discussed in relation to experiments on the control of breathing where blood, which is perfusing the chemoreceptors, has been in contact with artificial surfaces.

Animals↗