Molecular aspects of wound healing in diabetes

McLennan S, Yue DK, Twigg SM

Abstract
Previous research studies have clearly shown that failure of foot ulcer healing can eventually lead to amputation. It is therefore important that the diagnosis and treatment of ulcers is both timely and effective. Two major classes of regulators of extracellular matrix (ECM) – growth factors and the group of enzymes termed matrix metalloproteinases (MMPs) – and their effect on healing diabetic wounds are the focus of this study. A number of animal models of wound healing are also discussed, with the aim of developing strategies to improve the rate of tissue repair in diabetes.

<top>

---

Development and characterisation of human skin equivalents and their potential application as a burn wound model

Topping G, Malda J, Dawson R, Upton Z

Abstract
Wound healing is a complex physiological process; hence a reproducible in vitro model of skin provides a valuable tool to further understand the biology of dermal wound repair and to investigate techniques to improve wound healing. Human skin equivalent models (HSEs) have been proposed to serve as an in vitro model for these purposes; however, there is currently no readily available HSE model in Australia.
In this study, we describe the production of a HSE obtained by seeding human keratinocytes onto a de-epidermised dermis, (DED) which was then submerged in medium for 3 days and subsequently cultured at the air-liquid interface for up to 20 days. The model was characterised morphologically and biochemically over the 20 days of culture at the air-liquid interface and showed histological features similar to those observed in an in vivo epidermis. Immunohistochemistry of the epidermal markers keratin 6, keratin 14, keratins 1/10/11 and the basement membrane marker collagen type IV, revealed typical differentiation. The HSE was then examined for its potential as a burn wound healing model. Burn wounds were created in the model and the re-epithelialisation of the wounds was followed for 6 days by keratinocyte morphology; metabolic activity was analysed every 2 days. Keratinocytes began to migrate into the wound bed after 2 days and continued to migrate for the next 4 days, suggesting that the HSEs generated may be of great value for studies of the wound healing process and for the evaluation of new therapies.

<top>

---

Exploring cellular interactions relevant to wound healing

Ruzehaji G, Daehna I, Vareliasa A, Rayner T

Abstract
The specific involvement of individual cell types in wound repair is generally well understood. How cells interact with each other at the wound site and what effect this has on their healing-related functions, however, is not so clear. To begin exploring the influence cell-cell interactions have on wound healing, this article examines how inflammatory T cells effect skin fibroblast and keratinocyte function. Our studies show that T cells can reduce collagen production by fibroblasts and induce programmed cell death (apoptosis) in keratinocytes, with both of these outcomes having the potential to impair healing. Given that a number of different cell types are present in a wound, the challenge is to identify the cell-cell interactions that are beneficial and those that are detrimental to healing so they can be manipulated appropriately to promote repair.

<top>

---

Activated protein C (APC) as a novel agent to promote wound healing

Jackson CJ, Xue M

Abstract
Activated protein C (APC) is a serine protease that plays a central role in physiological anticoagulation and has, more recently, been shown to be a potent anti-inflammatory mediator. Recent work in our lab shows that APC upregulates expression and activation of matrix metalloproteinase-2 (MMP-2), an enzyme that plays a prominent role during angiogenesis in cultured human skin fibroblasts (HF), endothelial cells and keratinocytes (HK). Furthermore, APC promotes the migration and proliferation of these cells in vitro. In a full-thickness rat skin healing model, APC enhances wound healing compared to saline control. In summary, our results demonstrate that APC promotes cutaneous wound healing at least partly by upregulating MMP-2 activity, increasing angiogenesis, promoting re-epithelialisation and dampening inflammation. These unique properties of APC make it an attractive therapeutic agent to promote the healing of chronic wounds.

<top>

---

Role of sex hormones in acute and chronic wound healing

Strudwick X, Powell BC, Cowin AJ

Abstract
The sex hormones oestrogen and testosterone are important mediators of wound repair. Oestrogen enhances wound healing by reducing inflammation and enhancing matrix production. However, in post-menopausal women, when oestrogen levels are decreased, wound healing is impaired and susceptibility to chronic non-healing wounds increases. Surprisingly, although the speed of healing is impaired, an improvement in the quality of scarring is observed. Testosterone, in contrast, inhibits wound repair and is associated with enhanced inflammation.
One of the most important consequences of hormonal changes is the age-related delay in cutaneous wound healing observed in both males and females, which leads to substantial morbidity and mortality. Manipulation of hormone levels may provide alternative treatments for promoting healing in non-healing wounds and may be of value in promoting reduced scarring.

<top>

---

Role of the actin cytoskeleton in wound healing and scar formation

Cowin AJ

Abstract
The actin cytoskeleton is an essential network of filaments found in all cells and is important in the process of migration, adhesion and proliferation. All these processes are fundamental to wound repair. Members of the gelsolin family of actin-severing proteins are important regulators of cytoskeletal organisation. Manipulation of these proteins has revealed important roles in wound repair, suggesting that they may be potential new targets for therapeutic intervention to help improve wound healing and reduce scar formation.

<top>

---

---

Design and implementation for wound measurement application

Li D

Abstract
Chronic wounds are difficult clinical problems that consume a large amount of resources including medical and nursing time as well as cleansing solutions, other topical applications, dressing products, bandages and elastic stockings. Thus, there is a need to develop an accurate and fully objective database application for wound measurement. A software interface written in the VB.NET languages for the measurement of wounds has been developed. The system uses an accurate measurement method capable of detecting small changes in an open wound surface area. This paper further describes the development of a relational database to measure the surface area of a wound, with the intention of improving the efficiency of wound measurement.
Li D. Design and implementation for wound measurement application. Primary Intention 2006; 14(2): 56-58, 60-63, 66.

<top>

---

Collaborating to improve pressure ulcer prevention practices: The South Australian experience

McErlean B • Thomas L • Page T • Simunov K

Abstract
An examination of the organisational uptake of the Australian Wound Management Association's (AWMA) Guidelines for the Prediction and Prevention of Pressure Ulcers 1 in metropolitan hospitals across Adelaide identified that many were having difficulties implementing the recommendations, resulting in a continued high incidence and prevalence of pressure ulcer rates.
As a result, the South Australian Hospitals Safety and Quality Council funded a project to support organisations implement and evaluate local evidence-based prevention and management frameworks. Two project officers facilitated the process, bringing organisations together at regular intervals to share successes and stories and to learn from experts and from each other in order to identify strategies for each phase of implementation. An evaluation at the completion of the project identified some gains by all organisations and all had developed strategies to continue the work into the future.
Two participants' stories are described here to demonstrate the outcomes and achievements gained from organisations collaborating and supporting each other to achieve organisational change. Whilst it is too early to demonstrate reductions in prevalence rates, the project was successful in the goals of the collaborative, ensuring that all participants had truly begun the
task of implementing and evaluating robust and comprehensive evidence-based prevention and management frameworks across the continuum of care.
McErlean B, Thomas L, Page T, Simunov K. Collaborating to improve pressure ulcer prevention practices: the South Australian experience. Primary Intention 2006; 14(2): 67-73.

 

<top>

---

Small-vessel vasculitis

Rayner R

Abstract
Small-vessel vasculitis (SVV) refers to an inflammatory disorder of arterioles, venules and capillaries that leads to obstruction, ischaemia and infarction. The identification and management of SVV is a challenge for health professionals, with an accurate diagnosis requiring comprehensive evaluation of the clinical and pathological findings. Early diagnosis and aggressive management of the inflammatory process facilitate improved patient outcome. However, a lack of clinical trials means that treatment options vary according to the assessment, experts' advice and clinicians' experience.
Rayner R. Small-vessel vasculitis. Primary Intention 2006; 14(2): 76, 78-80.

 

Effects of cigarette smoking on cutaneous wound healing

Rayner R

Abstract
Cigarette smoking is one of the leading and most preventable health problems of Western society. Unfortunately, smokers provide a challenge for wound care practitioners as smoking is associated with impaired tissue restoration, increased risk of surgical wound infections and pressure ulcers and is a deleterious factor in the repair of post-surgical flaps and grafts.
Smoking inhibits healing through the effects of anoxia, hypoxia, impaired epithelialisation, vasoconstriction and enzymatic system toxicity. Individuals undergoing elective surgery may require additional assistance involving a multidisciplinary approach to cease smoking preoperatively. Managing patients' wounds that include an arterial component necessitates a holistic approach involving client education, regular dressing changes and liaison with the physician.

<top>

---

Improving pressure ulcer management in Australian nursing homes: results of the PRIME trial organisational study

Ellis I, Santamaria N, Carville K, Prentice J, Ellis T, Lewin G & Newall N

Summary
Pressure ulcer prevalence is frequently cited as a factor used to determine the quality of nursing care and is used as a proxy measure for nursing home quality. This paper reports the results of the organisational study conducted as a subcomponent of the PRIME trial. The PRIME trial was a multi-dimensional clinical trial designed to investigate the effectiveness of an integrated pressure ulcer management system in reducing the pressure ulcer prevalence and incidence in a cohort of Australian nursing homes. A stratified random sample of staff were interviewed from 17 consenting nursing homes (n=120). The interviews used a 10 question, semi-structured questionnaire covering four organisational quality factors and six PRIME trial implementation factors. Responses to questions were ranked on a scale of 1-5,1 representing no evidence and 5 representing embedded practice. Data were aggregated by nursing home and the mean scores were calculated. Data were correlated with baseline pressure ulcer prevalence and the post PRIME pressure ulcer prevalence.
The results of this study show that there was no relationship between baseline pressure ulcer prevalence and the context of care as measured by a range of organisational factors, including staff development planning, equipment and resource management, communication management and effectiveness of staff and resident feedback. The PRIME trial was able to significantly reduce prevalence of pressure ulcers regardless of the context of care. Paired sample t-tests showed a significant difference between the mean baseline prevalence (25.8%) and the mean post PRIME pressure ulcer prevalence (16.6%) (p=0.008) in nursing homes participating in the organisational component of the PRIME trial.

<top>

---

Case study: Fournier's gangrene: management of an extensive wound

Gibbins S

Abstract
Mr L, a 43 year old male with Type 2 diabetes, developed an infection in the right groin after a fall. He was diagnosed with Fournier's gangrene and underwent surgery four times for debridement of infected, necrotic tissue. An extensive wound extending from the right groin around to the right buttock with a 2cm margin from the anus was created. After 10 days of normal saline gauze packs, use of a topical negative pressure dressing was suggested. Problems with the irregularity of the wound margins, the location of the wound in the groin, and its proximity to the anus were overcome by an innovative approach to wound management.

<top>

 

Pressure injury: an exploration of the relationship between risk factors and interface pressure

Anne Gardner, Ann Marie Dunk, Marlene Eggert, Glenn Gardner & David Wellman

Abstract
Pressure injuries are a serious risk for patients admitted to hospital and are thought to result from a number of forces operating on skin tissue (pressure, shear and friction). Most research on interface pressure (IP) has taken place using healthy volunteers or mannequins. Little is currently known about the relationship between pressure injury risk and IP for hospital patients.
This relationship was investigated with a sample of 121 adult hospital patients. Pressure injury risk was evaluated using the Waterlow Risk Assessment Tool (WRAT) and IP was measured at the sacrum using a Tekscan ClinSeat™ IP sensor mat. Other factors considered were body mass index (BMI), blood pressure, reason for hospital admission, comorbidities and admission route to hospital. Patients were classified according to WRAT categories ('low risk', 'at risk', 'high risk', 'very high risk') and then remained still on a standard hospital mattress for 10 minutes while IP was measured.
Participants in the 'low risk' group were significantly younger than all other groups (p<O.OO1) and there were some group differences in BMI. IP readings were compared between the 'low risk' group and all of the participants at greater risk. The 'low risk' group had significantly lower IP at the sacrum on a standard hospital mattress than those at greater risk (p=O.002). Those at greater risk tended to have IP readings at the low end of the compromised IP range.
This study is significant because it describes a new, clinically relevant methodology and presents findings that challenge clinician assumptions about the relationships between pressure injury risk assessment and IP.

<top>

---

Wound cleansing: sorely neglected?

Michelle Carr

Abstract
Many authors are questioning the need to cleanse every wound, yet despite limited investigation on the topic, wound cleansing can reach ceremonial proportions and remains an integral element of wound management. Recent systematic reviews have examined physiological elements of wound cleansing and concluded that few practices are able to be definitively supported or refuted. The results of several influential studies that have been inducted into wound cleansing legend are marred by poor methodology, raising questions about their conclusions. While many authors dismiss wound cleansing practices as ritualistic, few studies have considered how nurses actually cleanse wounds. No studies have yet examined the psychological, cultural and socioeconomic aspects of wound cleansing and considered patient expectations and preferences.
This discussion paper examines nursing literature to consider the purpose of wound cleansing, to discover how nurses are actually cleansing wounds, to consider non-physiological elements of wound cleansing and to summarise recently published recommendations. This paper concludes that there is little evidence to guide wound cleansing practices and that there is an urgent need to further examine all aspects of this topic.

<top>

---

The role of nurse-led clinics in the management of chronic leg wounds

Rayner R

Abstract
Leg ulcerations are a chronic and debilitating condition that predominantly affects older adults. The management of leg ulcers consumes a substantial amount of financial and human resources in acute, chronic and community health settings. This literature review examines the prevalence of leg ulcers and their impact on the individual and on Australia's healthcare system. The review considers the need for comprehensive client and wound assessment to determine appropriate management options, and discusses the potential contribution that community leg ulcer clinics can make in the management of chronic lower extremity ulcerations.

<top>

---