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Biomedical subjects

P Potter

Publications and source records attributed to P Potter.

51 records · Page 3Linked to original sources

Treatment of Mooren's ulcer with cyclosporin A: report of three cases.

Three patients with severe, bilateral, progressive Mooren's ulcers, unresponsive to medical and surgical therapy, were treated with cyclosporin A. All three responded rapidly to the drug and there has been no recurrence of the Mooren's ulcers since (average follow-up 14 months). Peripheral blood T lymphocyte subsets were estimated prior to and during treatment. No significant abnormalities were found initially. Suppressor cells increased on treatment, and a corresponding drop of the helper/suppressor cell ratio occurred in two patients.

Aged↗

Leuko-araiosis: an ancient term for a new problem.

Recent research with computerized tomography (CT) and magnetic resonance imaging (MR) of the brain has revealed a type of tissue change for which no fitting term exists. The change appears as areas of decreased density on CT and changed signals of the white matter in MR images. Because neither a definite pathological change nor a specific clinical deficit has been linked with the CT and MR changes, a designation is required that limits itself to describing the changes themselves. We propose "leuko-araiosis". The Greek root leuko-, signifying "white", has found wide usage in modern medical terminology: e.g. leucine, leukocyte, leukorrhoea. Also several precedents exist for its application to the white matter of the central nervous system: e.g. leukoencephalitis, leukomyelitis, leukotomy. Araios is an adjective meaning "rarefield", and the suffix -osis converts the adjective to a noun meaning "rarefaction, diminution of density", a word used in the Hippocratic Collection to describe a state of excessive porosity of the lung. A descriptive term precludes premature presuppositions and encourages the search for causes.

Brain↗

A simple and sensitive method of acetylcholine identification and assay. Bioassay combined with minicolumn gel filtration or high-performance liquid chromatography.

A modified technique of acetylcholine assay on the guinea pig ileum has been combined with either minivolume gel filtration or high-performance liquid chromatography separation of the samples. In addition, labeled acetylcholine (14C-ACh) was eluted with unlabeled acetylcholine or with the samples expected to contain acetylcholine, and their elution profiles were compared by bioassay plus radioassay of eluate fractions. When the elution of both biological activity and label occurred in the same eluates, it was concluded that the substance assayed on guinea pig ileum was acetylcholine. The method was sensitive to 0.5 ng (1.8 pmol) of acetylcholine and its reproducibility was within 5%. It thus represents a substantial improvement in chemical specificity over the previous bioassay method described by Paton and Vizi (1969).

Acetylcholine↗

The effect of propranolol and dimethylpropranolol on cardiac conduction.

Isolated dog hearts perfused with blood from a donor dogand driven at two heart rates were used to compare the effects of propranolol with those of its quaternary ammonium derivative on atrial, atrioventricular (AV) nodal, and His-Purkinje conduction. Propranolol slowed only AV-nodal conduction, increasing the minimal conduction time and the effect of prematurity, without affecting fatigue. Practolol did not have this effect. Dimethylpropranolol had similar but not identical effects on the AV node, but also slowed atrial and ventricular conduction. In contrast with the quaternary derivative of lidocaine, dimethylpropranolol's effect on atrial and ventricular conduction was not dependent on the heart rate. The effect of dimethylpropranolol on ventricular conduction was observed at doses lower than those reported by others to be antiarrhythmic.

Animals↗

Echoencephalographs of 100 consecutive acute psychiatric admissions.

Echoencephalography (ECHO) on 100 consecutive acute short-term psychiatric admissions showed a high (12 per cent) incidence of abnormalities. Incidence of midline ECHO abnormalities was 2 per cent, comparable to similar studies. Ventricular enlargement accounted for the majority of ECHO abnormalities. This study also confirmed a previous report of a relationship between third ventricular size and response to treatment. Use of the ECHO as a screening test for these patients was safe and rapid. Correlative studies tended to confirm ECHO findings.

Adolescent↗

An upper body musculoskeletal assessment instrument for patients with work-related musculoskeletal disorders: a pilot study.

OBJECTIVES: To examine the reliability and validity of a new outcome measure, the Upper Body Musculoskeletal Assessment (UBMA). DESIGN: Twenty subjects physician-diagnosed as having work-related musculoskeletal disorders (WRMD) and ten healthy subjects were assessed using the UBMA on three separate occasions. All subjects with WRMD attributed their injury to equipment use on their job. RESULTS: The WRMD group had significantly higher UBMA scores on the side of equipment use than on the other side (p <0.01), whereas the healthy group had similar scores on both sides (p> 0.05). UBMA scores for the WRMD group were significantly greater on both sides of the body than scores for the healthy group (p<0.01). Only one test occasion was required to produce excellent reliability coefficients (ICCs>0.88). Although group reliability was excellent, changes of 24% for patients with WRMD and 44% for healthy subjects would be required for confidence that UBMA scores for individual patients on the side of equipment use had changed from baseline. CONCLUSIONS: Although testing on one occasion produced reliable UBMA scores, healthy subjects could be distinguished from patients with WRMD, and the side of equipment use could be distinguished from the other side in patients with WRMD, prediction of individual UBMA scores was poor. In its present form, the UBMA is useful for making decisions about groups but not about individual patients. Modifications of the current UBMA are required to reduce measurement error.

Adult↗

Environmental tobacco smoke exposure in children: household and community determinants.

To determine the most important sources of environmental tobacco smoke exposure to young children, the authors studied the associations among urinary cotinine, reported household smoking habits, and socioeconomic variables in 575 schoolchildren aged 6-11 y. The school children were among a population of prodigious smokers in Cape Town, South Africa. Eighty percent of the children were exposed to environmental tobacco smoke. Maternal smoking, which was adjusted for creatinine, accounted for 21.8% of the variation in urinary cotinine--more than all other sources combined. The male parent and other household smokers accounted for 12.7% of the variation, and socioeconomic indicators explained an additional 4.8%. By defining the ecological variable of smoking prevalence per school, the authors estimated a "community" contribution of 3.3%. The relative importance of different sources of smoke should be taken into account in the prevention of environmental tobacco smoke exposure in young children. Most importantly, of all the sources of environmental tobacco smoke, mothers' smoking habits had the greatest impact on exposure to children.

Adult↗

Steroids and bowel rest versus elemental diet in the treatment of patients with Crohn's disease: the effects on protein metabolism and immune function.

Recent studies have shown an elemental diet to be as effective as bowel rest plus steroids in the management of acute Crohn's disease. In order to investigate the metabolic and immunological effects of these two therapies, six patients with an acute inflammatory attack of ileal Crohn's disease were randomly assigned to receive steroids or elemental diet for 7 days. Immunological and protein metabolic studies were performed before and after therapy, protein kinetic rates being measured by the method of constant intravenous infusion of 14C-labeled leucine tracer. Clinical and symptomatic improvement was noted in all six patients with significant falls in sedimentation rate and platelet counts and increases in albumin concentrations. Both forms of treatment increased plasma amino acid flux and oxidation rates, whole body protein turnover and rates of incorporation of amino acid into albumin. However, the increased rates of protein metabolism in the patients given steroids were at the expense of body protein stores with a net (average) loss of 58 g of nitrogen over 7 days. While both forms of therapy were associated with suppression of lymphocyte subsets, complement and circulating immune complexes only the steroid regimen was associated with suppression of in vivo IgG synthesis rates. The results indicated that both forms of therapy were associated with clinical improvement, increases in protein turnover and evidence of reduced inflammatory activity. However, the beneficial effects of steroid regimen must be balanced against the deleterious effects on body protein stores; steroids and bowel rest without nutritional support should be avoided in malnourished patients.

Adult↗

Communicating the threat of emerging infections to the public.

Communication theory and techniques, aided by the electronic revolution, provide new opportunities and challenges for the effective transfer of laboratory, epidemiologic, surveillance, and other public health data to the public who funds them. We review the applicability of communication theory, particularly the audience-source-message-channel meta-model, to emerging infectious disease issues. Emergence of new infectious organisms, microbial resistance to therapeutic drugs, and increased emphasis on prevention have expanded the role of communication as a vital component of public health practice. In the absence of cure, as in AIDS and many other public health problems, an effectively crafted and disseminated prevention message is the key control measure. Applying communication theory to disease prevention messages can increase the effectiveness of the messages and improve public health.

Communicable Disease Control↗