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Biomedical subjects

David Hall

Publications and source records attributed to David Hall.

26 records · Page 2Linked to original sources
PubMed2003

A mouse model for studying rapid intraoperative methods of skin closure and wound healing.

BACKGROUND: We re-examine the adequacy of an albino (hairless) mouse dorsal distally based skin flap model by determining elastic modulus and by assessing viability after application of rapid intermittent stretch to facilitate wound closure. MATERIAL/METHODS: Modulus of elasticity was determined with materials testing. Viability was accessed by laser Doppler flowmetry and by quantifying marginal tissue necrosis (mm2) at 5 days. Effective length gained and tension relieved were measured by subjecting flaps to simple undermining plus 3-10 g of initial tension (linear stretch) using a skin hook. Immediate hemispherical stretch was applied with an implanted subcutaneous silicone balloon (Rapid Intraoperative Tissue Expansion or RITE) at 1 or 2 cycles of 3-8 min and 6-12 ml for each cycle. Flaps subjected to simple and extensive undermining with or without application of initial linear stretch served as postoperative controls. RESULTS: The elastic modulus of 9.85 (1.02) N/mm2 approximated the skin of the human face. Flowmetry demonstrated that all flaps were adequately perfused. Stretching significantly decreased flap tension and increased flap length over simple undermining alone. It drastically improved flap viability by provoking a 50-75% decline in 5-day necrosis. The benefits were dependent upon the initial linear tension applied, but independent of the timing, cycling, and volume selected for RITE and the flap dimensions at closure. CONCLUSIONS: Results demonstrate that the albino (hairless) mouse dorsal distally based skin flap is a reliable model for studying wound closure and that rapid intermittent stretching in this model facilitates closure and wound healing.

Animals↗
PubMed2002

A homogeneous high throughput nonradioactive method for measurement of functional activity of Gs-coupled receptors in membranes.

A method is described for measuring the activity of G(s)-coupled receptors in a nonradioactive homogeneous membrane-based assay. This method has several major advantages over currently used methods for measuring functional activity of G(s)-coupled receptors. The assay is high throughput (>150,000 data points/day using a single reader). Dimethyl sulfoxide tolerance is high ( approximately 10%). Compared to complex cell-based assays, there is limited potential for nonspecific compound action. This resulted in low compound hit rates in robustness screening, where hit rates from a simulated screen were 1.0% (antagonist screen) and 0.1% (agonist screen). No continuous cell culture is required for the assay, reducing cell culture overheads and allowing the screen to run every day. Automation is simple and requires no temperature- or humidity-controlled incubation. No radioactivity is required. The method relies on measurement of cyclic AMP (cAMP) generation by fluorescence polarization assay using commercially available reagents. Membranes (1-2 microg protein per well, containing anti-cAMP antibody) are transferred to 384-well plates containing 1 microl test compound. For antagonist screens, agonist is added 15 min later. After 30 min incubation at room temperature, one further assay reagent (fluorescein-cAMP in a buffer containing detergent) is added. The signal may be read after 1 h and is stable for greater than 12 h. Typical Z' for the assay is approximately 0.5.

Adrenergic beta-Agonists↗
PubMed1998

Leaving paediatrics: the experience of service transition for young disabled people and their family carers.

In February 1994 the Department of Health commissioned the authors of this article to look into the transition between paediatric services and adult services for young physically disabled people in the Trent Region. In carrying out this study 87 young people or carers were interviewed in three districts, Sheffield, Rotherham and Chesterfield. One of the main findings of the research was that there was a great deal of confusion around the notion of 'transition' from one service to another. For many the experience was summed up by feelings of abandonment; while others felt unsure about the implications of moving between services. This is highlighted in the differing perspectives of carers and young people. In this paper we describe the transition procedure in one of the three districts, Sheffield, and highlight the gaps that allow young people to fall through the service's net.

Journal Article↗
PubMedDate not supplied

Role of a paediatric nurse in primary care 1: research issues.

This study, which looked at the potential for the role of a paediatric nurse in primary care, was a tripartite partnership arrangement with Community Health Sheffield NHS Trust, the University of Sheffield and the Children's Hospital Sheffield. The study focused on the role and function of two qualified children's nurses each working within a different primary healthcare team (PHCT). It was important to allow the role to evolve without undue pressure, so that members of the PHCT could work with the nurses to establish what would be the most useful and relevant tasks to be carried out by the team. The methodological problems posed in this type of study where little was known about how a children's nurse would work in a PHCT resulted in exploring the concept of a formative evaluation process. The major data source and contribution to the evaluation were the nurses' reflective accounts of their role and function as members of the PHCT. Case studies written in the form of reflective diaries provided a self-critical approach to the record of tasks undertaken and explained why the service was taken up. Five constructions emerged: duplication and perceived threats to established nursing roles within the PHCT; improved care of children in PHCT settings; the nature of support for children and families; working as a nurse practitioner; and meeting unmet need. A clear need was demonstrated for a qualified children's nurse working in a community setting to raise the overall support and quality of care for a whole range of conditions which are currently low profile. There was evidence that these nurses met unmet need and were, at times, functioning as nurse practitioners and at times as advanced practitioners. This article, the first of two parts, focuses on the methods used and the associated problems. The second part will present the findings and discussions of the research.

Adolescent↗
PubMedDate not supplied

Role of a paediatric nurse in primary care 2: research findings.

This article is the second of a two-part article that presents the findings of a study focusing on the role and function of two qualified children's nurses, each working within a different primary healthcare team (PHCT). The first part described the variation in settings for community paediatric nurses, the paucity of literature discussing the role of a paediatric nurse working as a member of a PHCT, the application of a research methodology that incorporated practitioner values and experience, the application of naturalist inquiry and the use of a formative evaluation strategy which enabled the researcher to be involved in directing and supporting the research nurses with the data collection (Vol 11(22): 1452-60). This second part focuses on the findings and discussions where it was demonstrated that qualified children's nurses working in community setting contributes to raising the overall support and quality of care for a whole range of conditions currently perceived as low profile. There was evidence that these nurses catered for unmet needs and were, at times, functioning as nurse practitioners and on occasions as advanced practitioners. These findings may contribute as a catalyst for change in informing the development of children's nursing services as part of the Children's National Service Framework.

Community Health Nursing↗