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Biomedical subjects

Andrew Burd

Publications and source records attributed to Andrew Burd.

At least 37 records · Page 2Linked to original sources
PubMed2005

Hypertrophic response and keloid diathesis: two very different forms of scar.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Have a greater appreciation of the extent of differences and similarities between keloid and hypertrophic scarring. 2. Have a greater appreciation of the significance of the stage of maturation of a keloid or hypertrophic scar with regard to its morphologic, biochemical, and molecular profile. 3. More critically review basic science research that is based on poorly characterized scar tissue. 4. More critically review clinical studies that are based on poorly characterized scar tissue. BACKGROUND: Hypertrophic and keloid scars remain extremely challenging, particularly in their variable response to treatment. The understanding of hypertrophic and keloid scarring is evolving from a position where they were regarded as different stages of the same process to the contemporary perspective of two separate entities. This article reviews the differences in the two forms of scarring and discusses the implications for future research. METHODS: The authors conducted a MEDLINE search of all English language reviews linking key words "hypertrophic," "keloid," and "scarring." RESULTS: Over the past four decades, there has been considerable clinical and experimental research looking at the biological nature and therapeutic response of keloid and hypertrophic scarring. As more differences are emerging regarding the fundamental biology of the scars, investigators are giving more detailed characterization of their source material. It is evident that even within the broad categories of hypertrophic and keloid scarring there is a heterogenous distribution of pathologic connective tissue matrix biology. CONCLUSION: Considerable advances have been made in our understanding of the fundamental biology of scarring. As research methodology becomes even more sophisticated, it will be even more crucial to extensively characterize source material, recognizing major differences not only between keloid and hypertrophic scar but also between scars of varying stages of maturation and histomorphological, biochemical, and molecular variations within individual scars.

Apoptosis↗
PubMed2005

A study of Q-switched Nd:YAG laser irradiation and paracrine function in human skin cells.

BACKGROUND AND OBJECTIVES: This preliminary laboratory-based study looks at the paracrine release from human skin cells subject to sublethal Q-switched Nd:YAG 532 nm laser irradiation. STUDY DESIGN/MATERIALS AND METHODS: Human dermal fibroblast and keratinocyte cultures were exposed to sublethal energy using the Nd:YAG 532 nm laser. Altered gene expression was then screened using RT-PCR for a range of paracrine factors known to affect melanogenesis, basic fibroblast growth factor (b-FGF), hepatocyte growth factor (HGF), stem cell factor (SCF), melanocyte stimulating hormone (MSH), endothelin-1 (ET-1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and protease-activated receptor-2 (PAR-2). Enzyme-linked immunosorbent assay (ELISA) was used to confirm protein production. Conditioned medium was used to assess altered melanogenesis in a melanoma cell line. RESULTS: Fibroblasts exposed to sublethal radiation showed upregulation of b-FGF, HGF and SCF. This contrasts with keratinocytes which showed upregulation of IL-6. Elevated protein levels of b-FGF and SCF were confirmed by ELISA assay. Conditioned fibroblast medium was shown to stimulate melanogenesis in a melanoma cell line. CONCLUSIONS: This preliminary laboratory study reports, for the first time, specific gene upregulation using the Q-switched Nd:YAG 532 nm laser.

Cells, Cultured↗
PubMed2004

Use of dermal regeneration template in contracture release procedures: a multicenter evaluation.

Integra dermal regeneration template (Integra Life Sciences, Plainsboro, N.J.) is an effective treatment for full-thickness burns. It can also be useful in contracture release procedures; however, the clinical utility of a dermal regeneration template in contracture release procedures has not been adequately characterized. In this multicenter investigation, the outcomes of release procedures incorporating a dermal regeneration template for 89 consecutive patients, who underwent a total of 127 contracture releases, were retrospectively evaluated. The procedures involved the application of Integra, which includes a temporary silicone epidermal substitute and an artificial dermal layer. After formation of a neodermis, the silicone layer is removed and replaced with an epidermal autograft. Data on patient and contracture site history, treatment methods, physician assessments of range of motion or function, patient satisfaction, recurrence, and adverse events were collected with a standardized questionnaire. Release procedures for the study patients involved the neck, axilla, trunk, elbow, knee, hand, and other anatomical sites. The mean postoperative follow-up period was 11.4 months. At 76 percent of the release sites, range of motion or function was rated as good (significant improvement in range of motion or function) or excellent (maximal range of motion or function possible) by physicians. Responding patients expressed satisfaction with the overall results of treatment at 82 percent of the sites. No recurrence of contracture at 75 percent of the sites was observed during follow-up monitoring. Patient age and prior surgical treatment at the site did not significantly affect the results of treatment. However, outcomes were superior at mature sites, i.e., those for which more than 12 months had elapsed since the original injury. Postoperative complications rarely necessitated regrafting. These results indicate that a dermal regeneration template provides a useful alternative technique for contracture release procedures. The study data indicate that this approach leads to favorable functional outcomes and a high rate of patient satisfaction. This modality also seems to be versatile, because a range of anatomical sites are amenable to treatment with a dermal regeneration template, regardless of prior surgical treatment, and both pediatric and adult patients respond well to this form of therapy. Furthermore, Integra confers functional and cosmetic benefits similar to those of full-thickness grafts but without comparable potential for donor-site morbidity.

Adolescent↗
PubMed2004

Plastic surgery in the undergraduate curriculum: the importance of considering students' perceptions.

As the undergraduate medical curriculum becomes increasingly crowded the competition for time inevitably increases and surgical specialties have decreasing representation. Plastic surgery is regarded with some confusion in terms of its relevance to the generic doctor. Plastic surgeons have no doubt about the relevance of the specialty to undergraduates. Others see this as a very technical specialty dealing with complex reconstructions and surgical interventions or, as a rather indulgent specialty focusing mainly on glamour and cosmesis. This study focuses on students' perceptions of an undergraduate teaching program in plastic surgery. The reality is that highly pressured undergraduates do not have the luxury of time to consider the finer details of the specialties to which they are exposed. Their priority is to pass their examinations and, having addressed that concern, further information becomes an acceptable bonus. The conclusion is that if plastic surgeons are going to gain greater involvement in the undergraduate curriculum they must start with involvement in examinations and assessments. The students will then ensure that adequate and appropriate teaching time is allocated.

Attitude of Health Personnel↗
PubMed2004

In vitro cytotoxity of silver: implication for clinical wound care.

In this study, we look at the cytotoxic effects of silver on keratinocytes and fibroblasts. We have assessed the viability of monolayer cultures using the MTT and BrdU assays. The composition of the culture medium and also the culture technique were modified to assess the effects of culture 'environment' on the susceptibility of the cells to the toxic action of silver. Further in vitro, experiments were performed using tissue culture models to allow cellular behavior in three dimensional planes which more closely simulated in vivo behavior. The silver source was both silver released from silver nitrate solution but also nanocrystalline silver released from a commercially available dressing. The results show that silver is highly toxic to both keratinocytes and fibroblasts in monolayer culture. When using optimized and individualized culture the fibroblasts appear to be more sensitive to silver than keratinocytes. However, when both cell types were grown in the same medium their viability was the same. Using tissue culture models again indicated an 'environmental effect' with decreased sensitivity of the cells to the cytotoxic effects of the silver. Nevertheless in these studies the toxic dose of skin cells ranging from 7 x 10(-4) to 55 x 10(-4)% was similar to that of bacteria. These results suggest that consideration of the cytotoxic effects of silver and silver-based products should be taken when deciding on dressings for specific wound care strategies. This is important when using keratinocyte culture, in situ, which is playing an increasing role in contemporary wound and burn care.

3T3 Cells↗
PubMed2004

Syncope and burns.

Syncope is a common condition that may lead to serious injuries including burns and head injury. To date, here has been no specific discussion of syncope and burns in the literature. A retrospective case-note review of consecutive patients admitted to a Tertiary Burns Centre over a 3.5-year-period was conducted. Five hundred and fifty nine patients were admitted during the study period. Six of these had burns related to alterations of consciousness that excluded alcohol/drug ingestion and epilepsy. The mean percentage body surface area burnt was 9.7%, the mean length of hospital stay was 28.5 days and the mean length of stay per percentage surface area burnt was 4.0 days per percent body surface burnt. The mean size of the injury in syncopal patients is slightly larger than the general burns patients (8.4%) but the length of stay is doubled. This is partly related to surgery being delayed due to investigation of the syncope episode. Focused investigations should reduce both the overall length of hospital stay and the number of investigations.

Aged↗
PubMed2003

Prospective study on the treatment of postburn hyperpigmentation by intense pulsed light.

BACKGROUND AND OBJECTIVES: Postburn hyperpigmentation is a common phenomenon among Asian especially over grafted areas and sometimes over donor sites and healed wounds without skin graft. This condition is difficult to treat and can cause severe psychological distress. Intense pulsed light (IPL) has been used to treat melanocytic lesions with promising result. The role of IPL in treating postburn hyperpigmentation has not been explored. The purpose of this study was to assess the efficacy and complication of IPL in the treatment of postburn hyperpigmentation prospectively. STUDY DESIGN/MATERIALS AND METHODS: Nineteen Chinese patients with postburn hyperpigmentation were treated by IPL. There were 14 females and 5 males. Their age ranged from 8 to 51 years with a mean age of 29.4 +/- 11.6 years. The cutoff filters of 550, 570, and 590 nm were used for 3-7 treatments at intervals of 3-4 weeks. Patients were treated with an energy fluence of 28-46 J/cm(2), pulse width of 1.7-4 milliseconds, double pulse mode, and a delay of 15-40 milliseconds. RESULTS: Treatment results and complications were evaluated and scored after each treatment. Over 78% of the patients showed more than 50% clinical clearance and nearly 32% of the patients were able to achieve more than 75% clearing. Although two patients had no clinical response, one patient had 100% clearing. Three patients developed blisters and one patient had erythema that all resolved within 1 week without leaving permanent marks. They have been followed-up from 11-32 months and there was no recurrence of the hyperpigmentation. CONCLUSIONS: IPL is effective and safe in treating postburn hyperpigmentation in Asian patients.

Adolescent↗
PubMed2002

Allogenic skin: transplant or dressing?

The use of biological dressings is an established aspect of contemporary burns care. The type and source of these biological materials can give rise to both legal and ethical issues. This paper looks at these issues in relation to allogenic skin. It is argued, from a medical perspective, that non-viable allogenic skin, cannot be transplanted and so should therefore be classified both medically and legally as a dressing.

Animals↗
PubMed2002

Before the paradigm shift: concepts and communication between doctors and nurses in a burns team.

The evolution of care delivered by a multidisciplinary burns team is a function of the effectiveness of the professional communication between team members. In this exercise, we have explored concepts and communication between nurses and doctors in a burns team. Loosely structured weekly meetings were held over a 4-month period. The explicit objective was to determine and define the current model of burns care in a regional burn centre. The implicit objective, however, was to develop a mutual appreciation of actual and potential problems in communication. Consensus task identification was achieved at the end of each meeting with full compliance in completing the tasks before the next meeting. Although there was a unanimous commitment to the team concept, traditional, professional, paradigms persist. For nurses, the concept of holistic modelling predominated, whilst the disease centred paradigm remained the focus of medical modelling. Linguistic, cultural and professional barriers to effective communication were identified but did not readily conform to prior expectations. Experience in burns care can transcend these barriers more effectively than a common culture or profession. In conclusion, team work and team building is a complex process that can benefit from an ongoing process of re-evaluation. An obvious yet common error is to assume a level of mutual understanding that does not in fact exist. Stepping aside to re-explore fundamental principles on which team members base their personal and professional practice can help in elucidating and determining new paradigms of care, which can be evaluated and appropriately implemented. The consensus conclusion was that this approach was a very valuable investment in time in pursuing excellence in the field of burns care.

Attitude of Health Personnel↗