The six best abstracts submitted by ETRS members (of less than 40-years of age) for the Young Investigators Award were selected by a jury comprising five members of the ETRS board. They were unable to appoint a single winner, so the Best Presentation Prize was shared by Dr Sorensen (Copenhagen, Denmark) and Dr Patel (Cardiff, UK). The six selected each received a £500 travel award and an attractive souvenir. Both winners received an extra prize of £250 each. The three best posters submitted by ETRS members were also selected by a jury of ETRS board members. Those chosen were: Dr Chassot (Nice, France), Dr Dalton (Bristol, UK) and Dr Toriseva (Turku, Finland). They all received an award of £500, and an atractive souvenir.

The nine winning abstracts follow:

ABSTINENCE FROM SMOKING ENHANCES NEUTROPHIL BACTERICIDAL ACTIVITY AND REDUCES WOUND INFECTION

L T Sorensen1, H B Nielsen2, A Kharazmi3, T Karlsmark4 and F Gottrup4
1H:S Bispebjerg Hospital, Department of Surgery K and Copenhagen Wound Healing Center, Copenhagen, Denmark; 2H:S Rigshospitalet, Department of Anaesthesiology, Copenhagen, Denmark; 3H:S Rigshospitalet, Department of Microbiology, Copenhagen, Denmark; 4H:S Bispebjerg Hospital, Copenhagen Wound Healing Center, Copenhagen, Denmark

Background: Surgical wound infection is more common in smokers than non-smokers. The mechanisms are not clear but smoking-induced reduction in peripheral blood flow and tissue oxygen has been suggested.

Objective: The aim was to evaluate the effect of smoking and abstinence on neutrophil oxidative killing and healing of incisional wounds.

Methods: Two studies were conducted.
Study A: Blood sampling was done in twenty smokers during smoking and abstinence and once in sixteen never smokers. Neutrophil oxidative burst was determined by chemiluminescence of neutrophils stimulated with opsonized zymosan and formyl-Met-Leu-Phe.
Study B: Standardized incisional wounds were made on the nates in 48 smokers and 30 never smokers. Following one week of smoking, the smokers were randomized to continuous smoking or abstinence. Wounding was made after 1,4, 8, and 12 weeks and once in controls. Criteria for infection were purulent discharge with or without wound rupture or painful, hot, extending erythema indicative of cellulitis.

Results: In study A, the oxidative burst was 50% lower in smokers than never smokers (p<0.05) and after three weeks of abstinence the oxidative burst was equal to the level of never smokers. In study B, 12% of the wounds in smokers were infected compared to 2% in never smokers (p<0.05). Four weeks of abstinence reduced infections by 30% compared to continuous smoking (p<0.05).

Conclusions: Abstinence from smoking restores the bactericidal activity of neutrophils and reduces wound infections. Smokers should be encouraged to quit smoking four weeks before surgery to reduce the risk of wound infection.

MULTIPLE KERATINOCYTE PHENOTYPES ARE INVOLVED IN ACUTE AND CHRONIC WOUND RE-EPITHELIALISATION

G K Patel1, P E Bowler2, C Wilson3, P Price3, A Y Finlay2 and K G Harding3
1University of Wales College of Medicine, Dermatology, Cardiff, UK. Tel: +44 2920 747747, Fax: +44 2920 745161, patelgk@cf.ac.uk; 2University of Wales College of Medicine, Dermatology, Cardiff, UK; 3University of Wales College of Medicine, Wound Healing Research Unit, Cardiff, UK.

Keratinocyte maturation is characterised by expression of different cytoskeletal proteins, called keratins. Keratin expression is altered during wound re-epithelialisation. Keratins can be used to define keratinocyte phenotypes. The hypothesis that wound re-epithelialisation involves a single cell phenotype was studied in acute normal and moist wounds in healthy individuals (AW-H, n = 16), acute wound in venous leg ulcer patients (AW-D, n = 15), healing venous leg ulcers (H-VLU, n = 7) and non-healing wound venous leg ulcers (NH-VLU, n = 13), H-VLU was defined by a 40% or greater reduction in wound area over four weeks using conventional therapy. Immuno-histochemistry and -flourescence using monoclonal antibodies, conventional and also confocal laser scanning microscopy were used to characterise keratinocyte phenotypes. In AW-D and AW-H, irrespective dry or moist wound healing, 6 keratinocyte phenotypes were demonstrated (K5+K14, K10, K10+K16, K16, K16+K17 and K17). A comparison of clinical variables showed NH-VLU to be of greater duration (2 years, p = 0.02) and size (10cm2, p = 0.09) compared to H-VLU. The keratinocytes phenotypes were similar to those observed in acute wounds, but the expression of Kq10 was greater in ulcers 10cm2 (p = 0.05). Expression of a proliferation marker and integrins alpha 3, 5 and 6 were restricted to a single keratinocyte phenotype (K5+ K14). Also this keratinocyte phenotype (K5+K14) differed from others in its expression of the regulatory proteins NFIL-6, pc-Jun, STAT-1 and beta-catenin. These findings support the view that multiple keratinocyte phenotypes are involved in wound re-epithelialisation. Models of wound re-epithelialisation, epidermal culture and gene therapy in wound healing may need to be reconsidered, to include keratinocyte types.

INDOCYANIN GREEN VIDEO ANGIOGRAPHY; QUALITATIVE AND QUANTITATIVE EVAULATION OF BURN DEPTH

L P K Kamolz1, H L A Andel2, W Winter2, G Meissel2, M Frey1
1Division of Plastic & Reconstructive Surgery, Department of Surgery, Vienna, Austria. 2Department of Anaesthesia and Intensive Care, Dept of A. Vienna, Austria

Background: The key decision in the treatment of burns is to determine its depth. Traditionally, this had involved serial clinical examinations, a more or less subjective technique. Therefore, various techniaues, supplementing the clinical diagnosis, have been suggested, but none has achieved widespread acceptance. It has often been suggested that the blood flow in injured tissue indicates the extent of its damage. Aim of this study was to evaluate the impact of ICG angiographies in determining burn depth.

Methods: ICG angiographies were performed in twenty-five patients. All kinds of depth and aetiologies were analysed. Each patient was injected intravenously with a single dose of 0.2mg/kg ICG (ICG-Pulsion®). Perfusion of burn wounds was measured using the technique of laser-fluorescence-videography (IC-VIEW®). Digital videos were acquired, showing the uptake, steady state distribution, and the clearance of dye-marked blood from the burn area. The ICG-videos were interpreted qualitatively and quantitatively (fluorescence intensities of different areas with the burn wound) using a quantification software (IC-CALC®).

Results: ICG measurements correlated well with the burn depth, which was determined clinically and histogically (biopsies). 2a&deg; burns: areas of bright and homogenous fluorescence, quick uptake, constant and high steady state distribution and quick clearance, indicating patency of the small vessels of the sub-papillary and dermal plexus. 2b&deg; burns: darker areas yielding mottled fluorescence; slower uptake, less steady state distribution, indicating partial patency of the dermal plexus. 3&deb; burns: only large and discrete vessels or no signs of fluorescence, indicating little or no remaining blood flow in the dermis.

Conclusions: Our results indicate that ICG fluorescence angiography allows objective, qualitative and quantitative evaluation of burn depth.

THE DERMAL SCARTCH – A NEW MODEL OF PARTIAL THICKNESS WOUND HEALING IN HUMANS

C S J Dunkin1, J M Plear2, P Gillespie2, A Roberts2, M P H Tyler2 and D A Mcgrouther2
1Stoke Mandeville Burns & Reconstructive Surgery Research Trust, Aylesbury, UK,
<mrdunks@doctors.org,uk> 2Stoke Mandeville Burns & Reconstructive Surgery Research Trust, Aylesbury, UK.

Background: Surgeons caring for patients with burns have long recognised the association between depth of dermal injury and outcome in terms of scarring. There may be a crucial depth beyond which there is a phenotypic change in wound healing response. Previous work on this model has shown a quantitative difference in the cellular response to dermal injury.

Methods: To investigate the relationship between the depth of dermal injury and wound healing we have developed a dermal wound model that is graded from deep dermal at one end of the superficial dermal at the other. Wounds were observed for 36 weeks: blood flow changes were investigated using laser Doppler imaging (LDI); the appearance of the wound was recorded using digital photography; and scar development beneath the surface was studied in vivo using high frequency ultrasound (HFUS).

Results: A stereotyped dermal wound was produced on the lateral hip in 113 healthy volunteers. LCI demonstrated a clear stepwise increase in blood flow with increasing depth of injury. Digital photography demonstrated the development of scarring at the deep end of the wound with no obvious scarring at the superficial end. The 3D picture was completed by HFUS, which quantified the development of scar at the deep end of the wound.

Conclusions: We present a novel model of human wound healing that is well accepted with low morbidity. In 113 subjects we demonstrate that scarring is dependant on depth of dermal injury. This new model provides a powerful tool for the investigation of scarring and development of anti-scarring agents with intrawound and intrapatient controls. In vivo scar development in human incisional wounds using HFU has not been demonstrated previously.

THE CYTOKINE AND IMMUNOHISTOCHEMICAL PROFILES OF WOUNDS TREATED WITH A LIVING SKIN SUBSTITUTE COMPARED TO SPLIT-SKIN GRAFT OR DRESSING

M Griffiths, N O Ojeh and H A Navsaria
Queen Mary, Cutaneous Research, London, UK

Background: The living skin substitute, Apligraf, consists of allogenic neonatal keratinocytes and fibroblasts supported by a collagen gel. It has been shown to have some benefit in the healing of human wounds, however, the mechanism has not been elucidated in vivo.

Objectives: The aim of this study was to establish cytokine profiles using real time PCR in an acute
human wound healing model.

Method: Human volunteers had cosmetic tattoos removed by tangential excision to create 32 acute deep-dermal wounds. Apligraf sheets were applied to 16 wounds while non-adherent dressings (8) or conventional split skin grafts (8) were applied to control wounds. Four biopsies were taken per time point (1, 2, 3 or 7 days). RNA extraction, reverse transcription and analysis by real time-PCR were performed to determine the profile of IL-1, TGF-a, TGF-b1, TGF-b3 and (KGF). A panel of antibodies to inflammatory and wound healing proteins was used to examine angiogenesis, immune response, keratinocyte differentiation, keratinocyte proliferation and extracellular matrix formation.

Results: Levels of IL-1, TGF-b3 and KGF were elevated in Apligraf wounds compared to controls. All cytokines peaked at 48hrs, however TGF-b3 and KGF remained high at 7 days. Apligraf treated wounds had a significantly increased inflammatory response and proliferation but a decreased level of angiogenesis. Epidermal differentiation and collagen deposition were not affected at the early time points.

Conclusion: A distinct profile of cytokine expression is observed in acute wounds using quantitative PCR. Increased and sustained expression of TGF-b3 and KGF have pathological implications on the final clinical result. An increased inflammatory response may be due to the presence of an allogenic material.