Biomedical subjects

O Nixon

Publications and source records attributed to O Nixon.

3 recordsLinked to original sources

PubMed2004

Arachidonic acid reduces the stress response of gilthead seabream Sparus aurata L.

In this study the influence of the dietary level of the fatty acid arachidonic acid (ArA, 20:4n-6) was determined on the acute stress response and osmoregulation of adult gilthead seabream Sparus aurata L. Seabream were fed a diet containing either 0.9% or 2.4% of total fatty acids as ArA for 18 days before being subjected to a 5 min period of net confinement. Prior to this stressor, a subgroup of fish from both dietary treatment groups was treated with acetylsalicylic acid (ASA), an irreversible blocker of cyclooxygenase (COX). This would indicate whether any effects were caused by an enhanced synthesis of prostaglandins derived from ArA. The highest ArA levels were found in the kidneys, and these were further enhanced by dietary ArA-supplementation. In gill tissues, there were significant changes in all selected fatty acid classes 24 h after confinement, except for the docosahexaenoic acid (DHA, 22:6n-3): eicosapentaenoic acid (EPA, 20:5n-3) ratio. ArA feeding strongly reduced the cortisol response to confinement, which was partially counteracted by ASA treatment. ArA also attenuated the stress-associated increase in plasma osmolality and, in combination with ASA, enhanced the osmolality and plasma chloride levels, but reduced plasma sodium levels after confinement. Furthermore, ArA enhanced the branchial Na(+), K(+)-ATPase activity both before and after confinement, whereas feeding ASA diminished this effect. It appeared that the effects of ArA-supplementation could not always be ascribed to an increase in prostaglandin synthesis. It is advisable to determine the long-term effects of replacing fish oils in commercial diets with vegetable oils that contain no long-chain fatty acids, particularly in carnivorous/marine species with low fatty acid elongation and desaturation activities. The effects of a low dietary intake of ArA (and other polyunsaturated fatty acids) should be studied over a longer term, taking into account any consequences for the health of the fish.

Analysis of Variance↗

PubMed2000

Evaluation of a problem-based learning workshop using pre- and post-test objective structured clinical examinations and standardized patients.

BACKGROUND: Osteoporosis is a health care issue in which family physicians play a major role. Although awareness of osteoporosis is high, recent studies suggest that application of recent advances in its treatment to the clinical setting may be low. We have developed a problem-based learning intervention for osteoporosis in which paired rheumatologists and family physicians developed nine problem-solving clinical scenarios. An educational matrix was used to link specific case scenarios with individual teaching objectives, developed via a previous needs assessment. Family physicians participated in the workshop, developing best practice responses to the clinical scenarios with a trained facilitator and content expert. METHODS: To assess the impact of this intervention, family physicians participated in a pre- and post-test evaluation, using objective structured clinical examinations and standardized patients. Objective structured clinical examination stations tested knowledge, skills, and judgment relating to osteoporosis with respect to risk factors, use of appropriate investigations including bone mineral densitometry (BMD), strategies for the prevention of osteoporosis (both pharmacologic and nonpharmacologic), treatment options for established osteoporosis (bisphosphonates and hormone replacement therapy), and management of recent osteoporosis fracture. Participants were evaluated using a predetermined score generated by their responses to objective structured clinical examinations and standardized patients (max. score = 101). Evaluations were conducted anonymously, although participants had access to their own pre- and post-test results for personal feedback. The impact of the workshop was assessed by comparing pre- and post-test responses by group, by individual, and by station. RESULTS: Participants demonstrated a significant improvement in their post-workshop scores. Of 40 participants, 26 showed improvement in score (> +10), 13 showed modest change (+1 to +10), and 1 showed a marked decrease (> -10). The greatest improvements were seen in the management of the male osteoporosis patient, determination of risk factors for osteoporosis, and the use and interpretation of bone mineral densitometry. Family physicians reported general satisfaction with the content and format of both the workshop and the evaluation process. IMPLICATIONS: We conclude that this type of problem-based learning intervention workshop results in improved knowledge, skills, and judgment in the management of osteoporosis by family physicians as objectively assessed using a pre- and post-test format including objective structured clinical examinations and standardized patients.

Clinical Competence↗

PubMed1999

Case studies in osteoporosis: a problem based learning intervention for family physicians.

OBJECTIVE: To develop and evaluate a practice based small group (PBSG) learning intervention on osteoporosis for primary care physicians. METHODS: A needs assessment on osteoporosis was performed and objectives for a continuing medical education (CME) program developed by an interdisciplinary advisory committee. Nine clinical cases were developed for evaluation by CME participants with a trained facilitator and content expert using the PBSG format. The effect of the CME intervention was evaluated using a pre and post-test consisting of objective structured clinical examination stations and standardized patients. RESULTS: Fifty-four family physicians participated in 4 pilot PBSG learning sessions. The program format, content, and participant satisfaction was highly rated (> 3.35:4.0). Participants expected the program to have a significant effect on the practices (3:40:4.0). Ninety-eight percent of participants improved their pretest scores, with a mean increase of 13% (range 1-36%). CONCLUSION: Based on our experience, we advocate the use of PBSG learning interventions as an effective and acceptable method of providing CME by rheumatologists for their family physician colleagues. This format appears to be associated with a significant effect on knowledge, skills, and behavior as assessed by our study.

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