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Biomedical subjects

K G Harding

Publications and source records attributed to K G Harding.

At least 55 records · Page 3Linked to original sources
PubMed1997

Iodine released from the wound dressing Iodosorb modulates the secretion of cytokines by human macrophages responding to bacterial lipopolysaccharide.

Clinical data suggests that iodine released into the wound environment by Iodosorb may enhance the healing of chronic leg ulcers by a mechanism additional to its anti-bacterial activity. The macrophage is considered to play a central role in controlling wound healing and this study was designed to determine whether interaction with iodine could modulate macrophage cytokine output. The human macrophage cell line U937 was co-cultured with Iodosorb, Iodosorb conditioned medium or elemental iodine in the presence of optimal and sub-optimal stimulatory concentrations of bacterial lipopolysaccharide (LPS). The concentration of tumour necrosis factor-alpha (TNF alpha) and interleukin-6 (IL-6) were assayed in the culture medium after 24 hr culture. Co-culture with 0.25% Iodosorb, Iodosorb conditioned medium or 20 micrograms/ml iodine enhanced TNF alpha secretion (48 +/- 3% cytotoxicity in L929 bioassay to 78 +/- 2% cytotoxicity, +/-SD) by U937 cells stimulated with sub-optimal concentrations of LPS (0.25 ng/ml) and inhibited secretion of IL-6 from cells stimulated with 10 ng/ml LPS (> 750 pg/ml to 267 +/- 52 pg/ml, +/-SD, n = 4). Immunohistological staining of sections prepared from biopsies of chronic leg ulcers indicated that the majority of macrophages present were negative for TNF alpha. Thus one potential mechanism of action of iodine released from Iodosorb used as a wound dressing is to provide a pro-inflammatory stimulus in the wound tissue by activation of the resident macrophage population. This would result in a localized production of pro-inflammatory cytokines and generate an influx of monocytes and T-lymphocytes into the wound that may trigger the wound into a healing phase.

Animals↗
PubMed1997

T lymphocytes and the lack of activated macrophages in wound margin biopsies from chronic leg ulcers.

The objective of this study was to characterize the leucocyte infiltrate which accumulates at the margin of chronic wounds. These leucocytes are a rich source of cytokines and growth factors, and an inappropriate function of these cells may contribute to the maintenance of wound chronicity. The leucocyte populations were stained immunohistochemically with monoclonal antibodies specific for surface receptors which give an indication of cellular function. Wound margin biopsies taken from chronic leg ulcers exhibited a localized infiltrate of CD45+ leucocytes associated with vascularized tissue in the dermis adjacent to the wound margin. Lymphocytes were identified in highest numbers in this area and CD45RO+ T lymphocytes predominated over B lymphocytes, which were either absent or present in very low numbers. In the majority of chronic wounds examined, CD4+ T lymphocytes were present in greater numbers than CD8+ T lymphocytes with a mean (+/-SD) ratio of CD4+:CD8+ of 1.5 +/- 0.6. CD68+ macrophages were identified in all layers of the dermis at the chronic wound margin. In 60% of wounds examined, macrophages were negative for the activation associated markers CD16 (Fc gamma III receptor) and CD35 (C3b receptor). In those biopsies where CD16 and CD35 positive macrophages were observed these were preferentially located in the perivascular regions. These data indicate that as monocytes extravasate into chronic wound tissue they may be subjected to microenvironmental influences which either suppress or do not induce macrophage activation. Suppression of macrophage activation may lead to an inappropriate cytokine/growth factor secretion and contribute to the maintenance of wound chronicity.

Antigens, CD↗
PubMed1997

A comparison of two dressings in pressure sore management.

This study compared a polyurethane foam dressing with a hydrocolloid dressing for ease of application and removal, adhesion, conformability, absorbency and wear time. A randomised study was carried out, including 61 patients with stage two or three pressure sores in five centres in the UK. Dressings were applied for up to 30 days and assessments were carried out at each dressing change. The results indicated that both dressings are easy and convenient to apply; absorbency and ease of removal were significantly better with the polyurethane foam dressing than the hydrocolloid dressing; wear times were similar.

Aged↗
PubMed1997

A comparison of two dressings in the management of chronic wounds.

A hydropolymer dressing (Tielle) and a hydrocolloid dressing (Granuflex) were compared in a randomised controlled clinical study involving 100 patients with leg ulcers and 99 patients with pressure sores in the community. Statistically significant differences in favour of the hydropolymer dressing were detected for dressing leakage and odour production, but no statistically significant differences were recorded in the number of patients with either leg ulcers or pressure sores who healed in each treatment group.

Aged↗
PubMed1997

Social support for elderly patients with chronic wounds.

Few attempts have been made to measure the social support received by elderly patients with chronic wounds. To focus research on these issues, an established model integrating the various roles played by social support in the adaptation of patients to stressful situations was applied. Two questionnaires were used to measure perceived social support and coping in a sample of patients with leg ulcers (N = 15, mean age 70.4 years) or diabetic foot ulcers (N = 15, mean age 63.6 years) at two time-points over a four-month period. The results indicate that there were no statistical differences between the groups. The overall levels of social support were low, with emotional support recorded most frequently. The standardised scores for types of coping indicate no unusual patterns, although the scores for logical analysis were low. However, there was considerable variation in the types of coping strategies used by individuals.

Adaptation, Psychological↗
PubMed1996

Social support: some pragmatic implications for health care professionals.

The role of social support in promoting recovery from chronic illness has been the focus of a debate within the nursing and social science research communities. This paper reviews the literature on this important issue and discusses the implications for patient management. In providing holistic patient care, health care professionals need to reflect on the impact of this research for their clinical practice.

Chronic Disease↗
PubMed1996

Dressings for treating cavity wounds.

Two treatment protocols for the management of patients with non-infected cavity wounds were studied, using data obtained from both the community and the outpatients clinic. Patients were treated with either a polyurethane foam hydrophilic dressing (Allevyn) or a calcium sodium alginate dressing (Kaltostat). Although alginate fibres were found to be incorporated in tissue, both dressing regimes were found to be easy to use, effective and acceptable to patients and clinicians.

Adult↗
PubMed1995

Martorell's ulcer.

This paper reports a rare form of ulceration of the lower leg and, as a result of subsequent investigations and literature review, readdresses a recent debate regarding the legitimate classification of these ulcers as a separate disease entity.

Female↗
PubMed1995

Pressure sore prevention in a hospice.

This study investigated the influence on the number of pressure sores developing in patients nursed in a hospice when three levels of pressure support were used in association with a risk assessment tool. The study was designed as phase one of an epidemiological study examining the use of a modified Norton scoring system. This was followed by a second phase of the study, when patients were allocated to pressure sore support systems according to their risk assessment score. A total of 327 patients entered, 223 in phase one and 104 in phase two. A significant reduction in the development of pressure sores was observed in the second phase of the study.

Aged↗