An unusual cause of leg ulceration.
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Anticoagulants↗
Biomedical subjects
K G Harding
Publications and source records attributed to K G Harding.
Antibacterial activity of honey against strains of Staphylococcus aureus from infected wounds.
The antibacterial action of honey in infected wounds does not depend wholly on its high osmolarity. We tested the sensitivity of 58 strains of coagulase-positive Staphylococcus aureus, isolated from infected wounds, to a pasture honey and a manuka honey. There was little variation between the isolates in their sensitivity to honey: minimum inhibitory concentrations were all between 2 and 3% (v/v) for the manuka honey and between 3 and 4% for the pasture honey. Thus, these honeys would prevent growth of S. aureus if diluted by body fluids a further seven-fold to fourteen-fold beyond the point where their osmolarity ceased to be completely inhibitory. The antibacterial action of the pasture honey relied on release of hydrogen peroxide, which in vivo might be reduced by catalase activity in tissues or blood. The action of manuka honey stems partly from a phytochemical component, so this type of honey might be more effective in vivo. Comparative clinical trials with standardized honeys are needed.
Honey↗
Clinical evaluation of a new pressure-relieving mattress.
In introducing a new mattress into practice it is important to evaluate its performance from both the patient's and nurse's perspective. A total of 20 patients admitted to the integrated medical unit were recruited and nursed on a new pressure-relieving mattress offering two modes of pressure relief (Duo). All patients had been recently admitted to hospital and were considered to be 'at very high risk' of developing a pressure ulcer, with an initial Waterlow score > 20. Data were collected on admission, mid-point (three to four days) and study exit (seven days). The primary objective was to investigate the condition of patients' skin and the mode of choice for pressure relief. The secondary objective was to investigate reasons for nurses' and patients' choices. Structured interviews were conducted with the patient, ward nurse and research nurse whenever possible. Nineteen patients maintained or improved their skin condition during the evaluation.
Aged↗
Assessing practice in preventing pressure damage.
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Evidence-Based Medicine↗
The structure and composition of chronic wound eschar.
Wounds with a covering of eschar require debridement before optimal wound healing can proceed. There are several different methods available but these have been derived empirically with no direct evidence of the structure or composition of the tissue they are designed to remove, or of the potential autolytic mechanisms which are the targets for some of these treatments. The aim of this study therefore was to determine the composition of chronic wound eschar and hence identify potential targets for the induction of autolytic debridement. Chronic wound eschar was removed by surgical debridement and analysed using immunohistochemistry, polyacrylamide gel electrophoresis (PAGE) and gelatin zymography. Immunohistochemistry using antibodies specific for extracellular matrix (ECM) proteins revealed a definite tissue structure, consisting of many fibrous regions and fine fibrillar elements separated by areas of tissue which were of a more irregular and amorphous nature. An antibody specific for all leucocytes revealed the presence of leucocytes in the region of tissue closest to the wound bed. The presence of this leucocyte population correlated to elevated levels of gelatinase activity as identified by gelatin zymography. PAGE analysis identified various protein species in the range 3.5-60 kDa molecular weight. These data indicate that wound debridement is likely to require multiple enzyme specificities to degrade the eschar and that these enzymes may be supplied by inflammatory leucocytes infiltrating the eschar from the wound bed. The various protein species demonstrated by PAGE may represent ECM proteins, those with lower molecular weight possibly representing the degradation products of autolytic debridement.
Chronic Disease↗
How compression therapy works.
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Bandages↗
Human wound contraction: collagen organization, fibroblasts, and myofibroblasts.
The closure of ungrafted sacrococcygeal pilonidal sinus excisional wounds was studied in 15 patients. Wound punch biopsies were taken on a regular basis, and histologic sections were made. To document changes, computer-assisted morphometric image analysis was employed. Initial average wound depth was 37.8 +/- 4.6 mm, and complete closure (0 wound depth) was reached by 68 days. Wound contraction contributed 88 percent to wound closure, whereas the deposition of scar only contributed 12 percent. Maximum cells density within granulation tissue was reached by day 18. Myofibroblasts, identified by alpha-smooth muscle actin immunostaining, first appeared on day 11. Unlike those observed in laboratory animals, myofibroblasts were a minor cell population of granulation tissue, never exceeding 10 percent of the cells. The pattern of collagen fiber organization was documented by polarized light microscopy of Sirius red-stained sections. Early granulation tissue collagen fibers demonstrated a fine greenish birefringence, whereas more mature granulation tissue collagen fibers were thicker, displaying orange-yellowish birefringence. Myofibroblasts were associated exclusively with thicker collagen fibers, whereas fibroblasts were associated with both fine and thick collagen fibers. It is proposed that human wound contraction involves a volume change whereby normal dermal and adipose tissues are pulled into the defect by forces generated within fibroblasts.
Actins↗
A comparison of two amorphous hydrogels in the debridement of pressure sores.
This study compared the efficacy of two hydrogel dressings in the debridement of necrotic pressure sores. This randomised, controlled, assessor-blind, clinical trial involved 50 patients whose wounds were assessed weekly using computerised wound analysis for four weeks or until debrided. Debridement was identified when there was 80% red granulation tissue present and no sign of necrosis. There were no statistically significant differences in comfort, wound odour, surrounding skin condition or time to debridement between the two groups.
Adult↗
The use of cultured dermis in the treatment of diabetic foot ulcers.
The aim of this open, non-comparative study was to assess the potential benefit of tissue-engineered human dermis (Dermagraft) in healing long-standing, difficult-to-heal diabetic foot ulcers, and the practicality of its use in the UK. Six patients with full-thickness neuropathic diabetic foot ulcers which extended into subcutaneous tissue and had an area > 1 cm2 were included. The treatment was applied weekly for eight weeks and the patients were followed for a total of 24 weeks. Four patients completed the study, showing improvement ranging from a reduction of 26% in ulcer area to complete healing. Two patients were withdrawn after developing complications not associated with the treatment. We conclude that this tissue-engineered human dermis has a role in the treatment of diabetic foot ulcers as part of a comprehensive treatment package. A study to confirm effectiveness in a comparative trial and optimise patient selection is indicated.
Adult↗
Costs of dressings in the community.
This study compares the costs of dressings used in the treatment of patients with a variety of wound aetiologies. The two dressings investigated were a hydrocolloid dressing and a hydrocellular dressing. Secondary objectives included a comparison of dressing durability, time to complete healing, ease of wound cleansing and dressing removal. The study was an open prospective single-centre randomised parallel group trial involving 100 patients, treated in the community, who were randomised to the two dressing groups. For all aetiologies except pressure sores, the costs of the hydrocolloid dressing were less than the costs of the hydrocellular dressings. Similar healing rates were observed in the leg ulcer and 'other wound' groups. There were, however, significant differences in the number of healed wounds observed in patients with pressure sores treated with the hydrocellular dressing.
Aged↗
The chronic non-healing wound: how to make it better.
Chronic wounds are a commonly encountered problem. An understanding of their aetiology, combined with a systematic approach to their management, is fundamental to achieving an optimal environment for healing to take place.
Chronic Disease↗
Collagen VII expression in human chronic wounds and scars.
Collagen VII is the major structural component of the anchoring fibrils that stabilize the cutaneous basement membrane on the dermis. Disruption and, more usually, destruction of the basement membrane are characteristic of wounds that are slow, or fail, to heal, such as chronic lower-limb or pressure ulcers. In this study, the expression of collagen VII was analysed in 28 human chronic cutaneous wounds or scars using a reverse transcription-polymerase chain reaction (RT-PCR) technique. Collagen VII expression was detected in 26 of these 28 cutaneous wounds, but not in two wounds, neither of which showed any clinical evidence of healing.
Adult↗
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↗
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↗
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↗
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↗
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↗