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Biomedical subjects

D R Buchanan

Publications and source records attributed to D R Buchanan.

At least 19 recordsLinked to original sources

A public health perspective on research ethics.

Ethical guidelines for conducting clinical trials have historically been based on a perceived therapeutic obligation to treat and benefit the patient-participants. The origins of this ethical framework can be traced to the Hippocratic oath originally written to guide doctors in caring for their patients, where the overriding moral obligation of doctors is strictly to do what is best for the individual patient, irrespective of other social considerations. In contrast, although medicine focuses on the health of the person, public health is concerned with the health of the entire population, and thus, public health ethics is founded on the societal responsibility to protect and promote the health of the population as a whole. From a public health perspective, research ethics should be guided by giving due consideration to the risks and benefits to society in addition to the individual research participants. On the basis of a duty to protect the population as a whole, a fiduciary obligation to realise the social value of the research and the moral responsibility to distribute the benefits and burdens of research fairly across society, how a public health perspective on research ethics results in fundamental re-assessments of the proper course of action for two salient topical issues in research ethics is shown: stopping trials early for reasons of efficacy and the conduct of research on less expensive yet less effective interventions.

Bioethical Issues↗

Reflections on the relationship between theory and practice.

The paper presents an analysis of the problems that have created a gulf between theory and practice in health education. Drawing on the classical distinction made by Aristotle between theoria (natural processes) and praxis (social practices), the analysis traces the roots of the problem to the inadequacy and inappropriateness of the natural sciences model for studying human behavior. Because of the limits of the positivist methodology, the results of experimental, hypothesis-testing research can at best provide only minimal guidance to practitioners in program development. The paper then describes an alternative conceptualization of theory, and concludes with the implications of this alternative model for closing the gap between theory, research and practice.

Acquired Immunodeficiency Syndrome↗

An uneasy alliance: combining qualitative and quantitative research methods.

The paper describes the difficulties encountered in trying to combine qualitative and quantitative research methods in a study of the relationship between moral reasoning and teenage drug use. Four problems that arose in the attempt to reduce qualitative data to a quantitative format are described. These problems are: (1) making analytic sense of singular responses; (2) a mistaken logical inference that demands that each pattern of judgment should have discrete behavioral indicators; (3) the construction and use of ideal types; and (4) making analytic sense of universal responses. The roots of these problems are then traced to the underlying philosophical premises that distinguish the qualitative and quantitative research paradigms. The implications of the different goals, assumptions, and standards of evaluation informing each of the respective methods for future research are discussed.

Adolescent↗

Effectiveness of acarbose, an alpha-glucosidase inhibitor, in uncontrolled non-obese non-insulin dependent diabetes.

The effect of acarbose, an alpha-glucosidase inhibitor, on glycaemic control, was compared with placebo in a double-blind, randomised, group comparison study during 16 weeks in 20 non-obese non-insulin dependent diabetic patients in whom sulphonylurea treatment had been withdrawn. There was significant deterioration in glycaemic control as assessed by HbA1 following withdrawal of the sulphonylurea. There was no significant improvement in HbA1 between weeks 0 and 16 in either the acarbose (11.3% and 12.4% respectively) or the placebo group (10.6% and 12.2% respectively). In both the acarbose and placebo treated groups fasting glucose and insulin concentrations were unaltered. This study also suggests that acarbose was not an effective substitute for sulphonylureas in non-obese Type 2 diabetes uncontrolled by diet alone.

Acarbose↗

Cryptogenic bilateral fibrosing pleuritis.

We describe four patients with bilateral pleural effusions progressing to diffuse pleural thickening for which we have been unable to find any evidence of an infective, embolic or occupational aetiology. In order to avoid confusion with diffuse pleural thickening attributable to asbestos-related disease, the term cryptogenic bilateral fibrosing pleuritis is suggested. The patients differed from those with pleural shadowing due to asbestos in that none of them gave a history of asbestos exposure, all were ill, presented with chest pain which was not always pleuritic in character, and had dyspnoea, cough or malaise. They had pleural effusions of variable size, pleural shadowing radiographically and raised sedimentation rates. Computed tomography revealed bilateral extensive pleural thickening in all cases. All four were HLA B44 positive. Histology showed that in all cases the pleura was thickened by fibrous tissue. Both layers were affected and the pleural space was often obliterated. Otherwise the pleural surface was covered by organizing fibrin. Focal collections of lymphocytes were often present when the fibrous tissue abutted on the subpleural fat. No asbestos bodies were seen in any of the cases and in one patient electron microscopic fibre counts showed no excess of asbestos. Pleural decortication was successful in three patients. In one of these, contralateral disease was successfully controlled with corticosteroids, but the fourth patient has not improved on corticosteroids.

Adult↗

Neutrophil chemotactic activity in acute severe asthma (status asthmaticus).

Serum neutrophil chemotactic activity (NCA) was measured in patients with acute severe asthma (status asthmaticus) and compared with that in control subjects (mild asthma, stable chronic irreversible air-flow obstruction, allergic rhinitis, noninfective lung conditions, or asymptomatic). There were 9 subjects in each group. Statistically significant elevations (p less than 0.002) in NCA were detected in acute severe asthma when compared with each control group. Serial measurements of NCA were subsequently undertaken in 12 patients with acute asthma, at the time of admission to hospital, after 3 days of treatment, and on discharge after approximately 7 days. A highly significant (p less than 0.001) reduction in serum NCA activity on Day 7 compared with that on Day 0 was observed, and this correlated inversely with the improvement in lung function (PEFR). Gel filtration by fast protein liquid chromatography (FPLC) using Superose 6 prep grade (6PG) indicated that NCA in acute severe asthma was heterogeneous and consisted of at least 4 peaks of activity associated with proteins with molecular weights of approximately 800, 600, 150, and less than 20 kD. The 800- and 150-kD peaks were also observed in control subjects, but to a lesser degree. The 600- and less than 20-kD activities were virtually confined to the patients with acute severe asthma. FPLC chromatofocusing of the 600-MW peak from the acute asthmatics, using a Mono-P column and a pH gradient from 8.3 to 5.0, revealed considerable activity in fractions eluting between pH 6.0 and 7.0, which was not observed in the normal control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Ocular toxicity following ethambutol in standard dosage.

We describe a patient who developed rapid irreversible blindness following treatment with ethambutol in the recommended dose of 15 mg/kg body weight which in clinical practice is widely considered to be safe. This case exemplifies the potential risks of ethambutol and re-emphasizes the importance of instructing patients to stop the drug at once if they develop visual symptoms.

Adult↗

Effect of attitudes and beliefs on exercise tolerance in chronic bronchitis.

In 50 patients with chronic bronchitis the relation was assessed between exercise tolerance and pulmonary function and psychological factors, including subjective perception of exertion, mood, general psychiatric disturbance, and the attitudes and beliefs held by patients concerning themselves, their illness, and its treatment. Ventilatory capacity was significantly correlated with but a poor predictor of exercise tolerance. Subjective perception of exertion was most closely correlated with exercise tolerance. The distance walked in a 12-minute exercise test was significantly correlated with measurements of mood and with several attitudes and beliefs. Attitudes and beliefs greatly outweighed measurements of mood and ventilatory capacity as components in a multiple regression predicting distance walked in 12 minutes. This method of psychological assessment emphasises the importance of attitudes and beliefs in respiratory disability and may have useful applications in rehabilitation in other chronic diseases.

Adult↗

Enzymatic removal of formalin-fixed tissues from polyester arteries, and its effect on physical properties of fibers.

A method is presented that can be utilized for the removal of formalin-fixed tissues from arterial grafts without affecting fiber material properties. Such a method could prove highly useful for studying the changes in the structure and properties of graft fiber as functions of important clinical variables. Information on what actually happens to the arterial graft material in situ with passage of time is greatly lacking in the current graft literature. The method proposed involves treatment of the formalin-fixed fiber-tissue complex with an enzymatic preparation containing enzymes derived from the porcine pancreas (pancreatin) in solution with tris(hydroxymethyl) aminomethane buffer at pH 7.6. Studies with two different grafts--a Microknit Dacron Bifurcation from a clinical patient 10 1/4 years after implantation and stored in formalin for 11 months, and a Sauvage Filamentous Velour of Dacron from an animal 24 h after implantation and stored in formalin for nine months--showed that the treatment was highly effective in completely removing the tissues at concentrations of pancreatin as low as 2.5%. The same treatment given to the virgin yarns of grafts revealed no significant effects on tensile, dimensional, and morphological properties.

Animals↗

Saprophytic invasion of infarcted pulmonary tissue by Aspergillus species.

Saprophytic invasion of infarcted pulmonary tissue has received only passing reference in published reports. Five patients with colonisation of pulmonary infarcts by aspergillus are described, with discussion of the clinical and histopathological features. The characteristic features were widespread invasion of dead tissue by fungal hyphae, in three cases with liquefaction resulting in the production of a cavitated lesion. There was no evidence that the vascular thrombosis and the consequent infarction present in four cases were caused by the fungus. In two cases the lesions were resected as possible peripheral cavitated tumours, and in two they were incidental findings at necropsy in patients who had had carcinoma and received radiotherapy. In the fifth case the clinical diagnosis was pneumococcal pneumonia but the possibility of primary aspergillus pneumonia was raised.

Aged↗

Psychodrama: A humanistic approach to psychiatric treatment for the elderly.

Elderly psychiatric patients confined to institutions frequently become increasingly isolated and debilitated. The verbal therapies and medications traditionally used to help remotivate patients have not been found to be as effective in dealing with these patients. Psychodrama and the tenets of sociometry, however, have been found effective. The author describes a psychodrama program at St. Elizabeths Hospital in Washington, D.C., that has helped remotivate elderly patients and reintegrate them into a more active life in the hospital. The author provides a brief review of the literature and an introduction to the methodology and techniques of psychodrama, and presents two case studies of how the program has helped aged patients.

Aged↗