Search PubMed⌕ Search

Biomedical subjects

S Owen

Publications and source records attributed to S Owen.

At least 55 records · Page 3Linked to original sources
PubMed1994

DETERMINATION OF PROTEIN SYNTHESIS IN RAINBOW TROUT, ONCORHYNCHUS MYKISS, USING A STABLE ISOTOPE

It has been suggested (Houlihan, 1991) that the consumption of 1 g of protein in a variety of species of fish stimulates the synthesis of, approximately, an equal amount of protein. Although synthesis of protein may account for as much as 40 % of the whole-animal oxygen consumption (Lyndon et al. 1992), only about 30 % of the synthesized proteins are retained as growth (Houlihan et al. 1988; Carter et al. 1993a,b). Thus, one focus of attention is the potential advantage gained by fish in allocating a considerable proportion of assimilated energy to protein turnover in contrast to relatively low-cost, low-turnover protein growth (Houlihan et al. 1993). Rates of protein synthesis in several species of fish have been measured using radioactively labelled amino acids, frequently given as a flooding dose (reviewed by Fauconneau, 1985; Houlihan, 1991). These measurements cannot be made for longer than a few hours because of the decline in specific radioactivity in the amino acid free pool. However, as protein synthesis rates vary during the course of a day as a result of the post-prandial stimulation, and since radiolabelled amino acid methodology is invasive, short-term and terminal, it has been difficult to be certain of the relationship between protein growth measured in the long term and protein synthesis rates measured in the short term. This paper addresses these problems by developing a method using 15N in orally administered protein to measure protein synthesis rates in fish over relatively long periods, the aim being to use procedures that are as non-invasive and repeatable as possible. The use of stable isotopes to measure protein metabolism is well established in terrestrial mammals (see Rennie et al. 1991; Wolfe, 1992), but to our knowledge the only published data for aquatic ectotherms are on the blue mussel (Mytilus edulis L.) (Hawkins, 1985). In the present study, rates of protein synthesis of individual rainbow trout [Oncorhynchus mykiss (Walbaum)] were calculated from the enrichment of excreted ammonia with 15N over the 48 h following the feeding of a single meal (dose) containing protein uniformly labelled with 15N by use of an end-point stochastic model (Waterlow et al. 1978; Wolfe, 1992). Application of this type of modelling would appear to be ideal for measuring ammonotelic fish nitrogen metabolism since, unlike the situation in mammals, the catabolic flux of amino acids through urea is very small. Further, ammonia is excreted directly into the surrounding water via the gills and is not stored for any length of time, in contrast to the situation in mammals, so the rate of tracer appearance is easily measurable.

Journal Article↗
PubMed1993

Identifying a role for the nurse teacher in the clinical area.

This paper describes a project which sought to identify a model to provide direction for nurse teachers working in clinical areas. Using an action research approach, the clinical teaching role was explored by working with trained nurses on one psychiatric ward. Two action plans were formulated, implemented and evaluated. The first involved working towards improving the learning environment and the second towards developing the ward manager's teaching role. The author concludes by recommending that teachers need to adopt a multi-dimensional role in the clinical area working as researchers, teachers and change catalysts.

Clinical Competence↗
PubMed1992

Devising a checklist to evaluate the non-verbal aspects of teaching skills and delivery.

This article proposes that teachers should constantly reflect upon and evaluate their performance if they are to improve teaching skills and delivery. Interaction Analysis and a true qualitative (anthropological) approach to evaluation are critically reviewed and are considered unsuitable for a teacher wanting to self-assess performances regularly. The use of a checklist in combination with video recording of the session to be evaluated is suggested as an alternative. An example of a checklist designed to focus on non verbal skills is given together with an overview of 'ideal' teacher behaviours.

Employee Performance Appraisal↗
PubMed1991

Hypertonic citrate solution as an alternative to modified Euro-Collins' solution for lung preservation.

In a canine model of acute ischemic lung injury, a hypertonic citrate solution (HTC) widely used for renal preservation in the United Kingdom, was compared with modified Euro-Collins' solution (ECS) currently the most widely clinically used pulmonary perfusate. Ten beagle dogs underwent left thoracotomy and exclusion of the left lung in situ. The lung was flushed with 30 ml/kg of either HTC or ECS and subjected to 60 min of warm ischemia. The circulation to the lung was then restored, the contralateral lung excluded, and the animal ventilated at a fixed FiO2 of 0.4 for 4 hr. Lung function was assessed by arterial oxygenation and hemodynamic measurements and, following sacrifice, by lung weight gain, bronchoalveolar lavage, and ultrastructural studies. Flush perfusion with HTC was associated with significantly less severe reperfusion injury, as determined by superior arterial oxygenation (PaO2 at 1 hr: HTC--152 mmHg [(95% confidence interval) CI] [122-182], ECS--59 [47-70]; PaO2 at 4 hr: HTC--124 [100-149], ECS--51 [42-61]), lower pulmonary vascular resistance index (PVRI at 4 hrs: HTC--838 dynes sec cm-5m-2 [651-1075], ECS--1233 [963-1588]); and lower lung weight (HTC--85 g [66-107], ECS--146 [114-184]). Bronchoalveolar lavage studies demonstrated an influx of neutrophils following reperfusion that was significantly less marked in the HTC group (increase in % neutrophils: HTC 24 [19-29], ECS 77 [72-82]). Lung injury assessed by electron microscopy tended to be less severe in the HTC animals. We conclude that HTC may offer an alternative superior to ECS for lung preservation.

Animals↗
PubMed1991

Acquired cervical spine impairment in young adults with cerebral palsy.

Three patients with spastic cerebral palsy and no associated movement disorder--each of whom presented with loss of functional skills and delay in the definitive diagnosis of cervical myelopathy--are reported, in order to increase awareness of the possibility of cervical spine pathology in these adults. The possibility of myelopathy should be investigated when considering the etiology of functional deterioration. A functional neurological examination for all multiply disabled individuals is proposed as a reference for future comparison.

Adult↗
PubMed1990

Attenuation of nocturnal asthma by cromakalim.

In a randomised, double-blind, crossover study, single oral doses of cromakalim, a potassium-channel activator, or placebo were given to 23 patients with nocturnal asthma. There was a significant reduction (p less than 0.005) in the early morning fall in forced expiratory volume in 1 s (FEV1) after 0.5 mg cromakalim (fall 9.8% [SEM 3.2%]) compared with placebo (18.5 [2.8]%). In a repeat dosing study, administration of 0.25 mg and 0.5 mg cromakalim on 5 consecutive nights to a further group of 8 asthmatic subjects significantly reduced the early morning fall in FEV1 from 28.7 (6.5)% after placebo to 19 (4.2)% after 0.25 mg and 14.9 (6.5)% after 0.5 mg. Potassium-channel activators may be useful in the treatment of asthma, especially for nocturnal symptoms.

Adult↗
PubMed1990

Control of house dust mite antigen in bedding.

Bedding has been constructed with a vapour-permeable waterproof fabric that is impermeable to house dust mite antigen (Der p1). Der p1 levels per gram of mattress dust after 12 weeks' use of the new covering were 1% of levels in control samples from mattresses cleaned conventionally.

Adolescent↗
PubMed1990

Amelioration of lung ischemic injury with prostacyclin.

The single-flush technique of lung preservation is thought to be enhanced by prostaglandin treatment. In order to test this hypothesis, ten beagle dogs underwent thoracotomy and in situ flush perfusion of the excluded left lung with 30 ml/kg of cold, modified Euro-Collins' solution. Group 1 (n = 5) received pretreatment with 30 ng/kg/min of PGI2 by infusion and as an additive to the flush (20 micrograms/L). Group 2 (n = 5) received no PGI2 and served as controls. Following 60 min of warm ischemia, the left lung was reperfused, the contralateral lung excluded, and the animal ventilated at a fixed FiO2 of 0.4 for 4 hr. The severity of reperfusion injury was assessed by arterial oxygenation and hemodynamic measurements and, following sacrifice, by lung weight gain and bronchoalveolar lavage and ultrastructural studies. PGI2 therapy resulted in significant amelioration of reperfusion injury, with superior oxygenation at both 1 and 4 hr (PaO2 at 1 and 4 hr, respectively; PGI2: 145 mmHg +/- 17.0 and 114 +/- 11.2; no PGI2: 59 mmHg +/- 5.8 and 51 +/- 4.5; P less than 0.01 at both times), lower pulmonary vascular resistance index at 4 hr (PVRI; PGI2: 913 dynes sec cm-5m-2 +/- 91; no PGI2: 1239 +/- 68; P less than 0.05) and lower lung weight (PGI2: 76 g +/- 4; no PGI2: 146 +/- 10; P less than 0.001). Bronchoalveolar lavage studies revealed an influx of neutrophils following reperfusion that was less marked in the PGI2 group (increase in % neutrophils; PGI2: 50.4 +/- 6.7; no PGI2: 76.9 +/- 6.0; P less than 0.05). Lung injury score assessed by electron microscopy was lower in the PGI2 group (PGI2: 5.2 +/- 1.1; no PGI2; 8.1 +/- 0.5; P less than 0.05). It is concluded that PGI2 treatment is protective against ischemic lung injury in this model.

Animals↗
PubMed1990

AIDS and UK respiratory physicians: attitudes to confidentiality, infection control, and management.

Respiratory physicians are concerned in the management of most patients with AIDS. Attitudes and practices of 463 respiratory physicians in the United Kingdom in relation to confidentiality, infection control, and treatment were sought by questionnaire from December 1987 to March 1988; 266 replies were received. Thirty eight per cent of respondents had not seen an HIV positive patient at the time of the survey. Respiratory physicians followed General Medical Council guidelines in relation to consent and confidentiality, except that if the patient's consent was withheld three quarters of the physicians would still inform an at risk hospital health care worker; only a quarter, however, would inform an at risk spouse. Routine infection control was frequently inadequate and "disease specific"--that is, substantially increased for known HIV positive patients. Given an HIV positive patient with respiratory symptoms and an abnormal chest radiograph, two thirds of respiratory physicians said that they would treat empirically for Pneumocystis carinii pneumonia as opposed to immediate bronchoscopy for accurate diagnosis. If a patient with AIDS who had pneumocystis pneumonia developed respiratory failure, half the physicians said at that time that they would elect not to ventilate the patient.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Human selenium status and glutathione peroxidase activity in north-west England.

Nutritional selenium deficiency disease, due to low soil selenium content, is well recognized in British livestock. The adequacy of the selenium status of 25 healthy human volunteers, 50 blood donors, 94 general medical patients and 106 allergy clinic patients was investigated in 1987/8 by measuring serum selenium concentration and platelet glutathione peroxidase activity. Mean serum selenium concentration for the entire study population was 92 micrograms/l. Significant linear correlations between serum selenium concentration and peroxidase activity indicate that a substantial proportion of both healthy volunteers and medical patients are of low selenium nutritional status. Twenty-five per cent of healthy volunteers and 50 per cent of medical patients had serum selenium values below those required for full expression of selenium-dependent enzyme activity. Deficiency of the antioxidant activities of selenium and selenium-dependent enzymes may be relevant to geographical differences in morbidity from a wide range of human disease states.

Administration, Oral↗
PubMed1989

MS: a localized immune disease of the central nervous system.

The precise role of T cells in multiple sclerosis (MS) remains to be defined. No MS-specific antigen has been found. The autoimmune hypothesis for MS rests on immune changes seen in the spinal fluid and brain and on the demonstration, in an experimental animal model, that T cells raised to myelin basic protein transfer demyelination. In this review, Virginia Calder and colleagues focus on recent studies suggesting that in MS, the initial T-cell response occurs within the central nervous system and that the blood poorly reflects this immune activity. This contrasts with the animal model, experimental allergic encephalomyelitis, where the initial immune response is peripheral.

Central Nervous System↗
PubMed1989

Correlates of drug therapy of diastolic blood pressure between 80-89 mm Hg by physicians in the community.

We have conducted a random probability survey of primary care physicians (n = 477) to examine the factors which might influence the level of diastolic blood pressure (DBP) felt by physicians to warrant antihypertensive drug therapy in young adults. Of the responding physicians, 18.4% reported treating young adults who had a DBP of less than 90 mm Hg. This practice was correlated with physician opinions about the efficacy of hypertension treatment and the reported influence of pharmaceutical representatives on physician practice. We conclude that reported therapy of DBP less than 90 mm Hg in young adults is highly prevalent. Such therapy is correlated with physician opinions as well as the perceived influence of pharmaceutical sources of information.

Adult↗