Wound debridement potential of glycosidases of the wound-healing maggot, Lucilia sericata.

The wound-healing maggot, Lucilia sericata Meigen (Diptera: Calliphoridae), degrades extracellular matrix components by releasing enzymes. The purpose of this study was to investigate the glycosylation profiles of wound slough/eschar from chronic venous leg ulcers and the complementary presence of glycosidase activities in first-instar excretions/secretions (ES1) and to define their specificities. The predominant carbohydrate moieties present in wound slough/eschar were determined by probing one-dimensional Western blots with conjugated lectins of known specificities. The presence of specific glycosidase activities in ES1 was determined using chromogenic and fluorogenic substrates. The removal of carbohydrate moieties from slough/eschar proteins by glycosidases in ES1 was determined by two-dimensional electrophoresis and Emerald 300 glycoprotein staining. α-D-glucosyl, α-D-mannosyl and N-acetylglucosamine residues were detected on slough/eschar-derived proteins. Furthermore, it was demonstrated that the treatment of slough/eschar with ES1 significantly reduced uptake of the carbohydrate-specific stain. Subsequently, α-D-glucosidase, α-D-mannosidase and N-acetylglucosaminidase activities were identified in ES1. Specific chromogenic and fluorogenic substrates and gel filtration chromatography showed that these activities result from distinct enzymes. These activities were mirrored in the removal of α-D-glucosyl, α-D-mannosyl and N-acetylglucosamine residues from proteins of slough/eschar from maggot-treated wounds. These data suggest that maggot glycosidases remove sugars from slough/eschar proteins. This may contribute to debridement, which is ultimately accomplished by a suite of biochemically distinct enzymes present in ES1.

Maggot chymotrypsin I from Lucilia sericata is resistant to endogenous wound protease inhibitors.

BACKGROUND: A chymotrypsin found in the secretions of Lucilia sericata and manufactured as a recombinant enzyme degrades chronic wound eschar ex vivo. OBJECTIVES: To characterize the inhibition profile of the L. sericata recombinant chymotrypsin I. METHODS: Activity of recombinant chymotrypsin I and its sensitivity to endogenous inhibitors were determined enzymatically using the fluorogenic substrate succinyl-alanyl-alanyl-prolyl-phenylalanyl-aminomethyl coumarin. RESULTS: We report the presence of high concentrations of two endogenous inhibitors, α1-antichymotrypsin and α1-antitrypsin, in wound eschar and a trace of a third, α2-macroglobulin, with the potential to inhibit this debridement process. However, the addition of a soluble and inhibitor-containing extract of chronic wound eschar to chymotrypsin I did not affect activity of the enzyme, neither did the addition of purified native α1-antichymotrypsin or α1-antitrypsin, although chymotrypsin I was inhibited by α2-macroglobulin. Conversely, the mammalian equivalent, α-chymotrypsin, was inhibited by the purified native α1-antichymotrypsin, α1-antitrypsin and α2-macroglobulin and by the soluble extract of wound eschar. CONCLUSIONS: The data suggest that the maggot-derived chymotrypsin I is biochemically distinct from human α-chymotrypsin and the lack of inhibition by wound eschar suggests a means by which chymotrypsin I activity survives within the wound to contribute towards debridement during maggot biotherapy.

Degradation of eschar from venous leg ulcers using a recombinant chymotrypsin from Lucilia sericata.

BACKGROUND: Larvae of the greenbottle Lucilia sericata are used to debride nonhealing wounds and stimulate the production of fresh granulation tissue. Previous publications have shown that secretions from L. sericata contain a number of proteolytic activities including a chymotrypsin that degrades a number of extracellular matrix components such as fibronectin, laminin and collagen. OBJECTIVES: To produce a recombinant L. sericata chymotrypsin (chymotrypsin I) and determine its effects on the degradation of patient wound eschar. METHODS: An active recombinant chymotrypsin I from L. sericata was cloned and expressed in Sf9 cells and its subsequent effects ex vivo on eschar from venous leg ulcers were determined by two-dimensional electrophoresis. RESULTS: The recombinant enzyme had the attributes of a chymotrypsin, possessing sequence homology with other chymotrypsins and demonstrating attributes of the native enzyme including cleavage of the chymotrypsin substrate succinyl-alanyl-alanyl-prolyl-phenylalanyl-7-amino-4-methyl coumarin, inhibition by phenylmethylsulphonyl fluoride and lack of inhibition by amidinophenylmethylsulphonyl fluoride. Importantly, the recombinant chymotrypsin cleaved the majority of proteins from slough/eschar from venous leg ulcers in a superior manner to chymotrypsins from human and bovine sources. CONCLUSIONS: The ex vivo degradation of eschar from venous leg ulcers indicates the potential value of recombinant chymotrypsin I as a novel, stand-alone debridement agent.

Updates from the British Association of Dermatologists 87 th annual meeting, 10-13 July 2007, Birmingham, U.K.

This is a synopsis of the main research and clinical findings presented at the British Association of Dermatologists meeting held during 10-13 July 2007 in Birmingham, U.K. The conference highlighted the recent biological, epidemiological and therapeutic advances that have been made recently in the field of dermatology. The authors focus on the more important advances or summaries of findings, but this is not meant as a substitute for reading the conference proceedings and related references quoted in this article.

Enzymes, detergents and skin: facts and fantasies.

In their raw state, enzymes of bacterial/fungal origin cause allergic reactions in the lung. Proteolytic enzymes also cause irritation to skin, eyes and the respiratory tract. For 40 years, encapsulated enzymes have been used worldwide in detergent products, especially laundry formulations, and have increasing importance due to biodegradability and functionality at low temperatures, offering environmental benefits. Uniquely to the U.K., for years it has been suggested that the inclusion of enzymes in such products leads to adverse skin reactions, including erythema, pruritus and exacerbation of eczema. In this review, we look at the facts, asking whether there is evidence that the hazards identified for enzymes translate into any risk for consumer health. By considering the actual exposures in consumer use and exaggerated product usage, it is concluded that the irritating and allergenic hazards of enzyme raw materials do not translate into a risk of skin reactions, either irritant or allergic. Investigations of numerous individuals with skin complaints attributed to laundry products demonstrate convincingly that enzymes were not responsible. Indeed, enzyme-containing laundry products have an extensive history of safe use. Thus, the supposed adverse effects of enzymes on skin seem to be a consequence of a mythology. The important practical lesson is that when primary or secondary care practitioners are presented with a skin complaint, it should not be dismissed as a result of using an enzyme-containing laundry product as the diagnosis will certainly lie elsewhere. Education for healthcare professionals could usefully be enhanced to take this on board.

Intervention development in occupational research: an example from the printing industry.

BACKGROUND: Intervention development research is an essential prerequisite of any study that attempts to determine whether specific interventions work to prevent work related injury and illness. METHODS: Focus groups (n = 5) and direct observational studies (n = 21) of printers were used to elicit key issues that would aid the development of subsequent interventions. Transcripts from these were analysed by standard qualitative methods to identify common and related themes. RESULTS: The views of managers differed significantly from those of print workers in a number of areas, and working practices did not always follow policy. The majority of printers did not perceive dermatitis to be a major problem, although many complained of dry hands. Other key results included: the lack of skin care policy in most companies; poor understanding of the nature, causes, and treatment of dermatitis; low priority of dermatitis within health and safety concerns; little or no provision of occupational health services, particularly skin checks; variability in provision of and access to appropriate skin protection; and lack of accessible washing facilities. CONCLUSIONS: As a result it was decided to evaluate the implementation of four INTERVENTIONS: provision of (1) skin checks and treatment advice; (2) gloves of the correct type and size, and use of an after-work cream; (3) information on dermatitis within the printing industry; and (4) development of best practice skin care policy.

Updates from the British Society for Investigative Dermatology Annual Meeting, 16-18 April 2007, Nottingham, U.K.

This is a synopsis of the main research findings presented at the British Society for Investigative Dermatology meeting held during 16-18 April 2007 in Nottingham, U.K. The conference highlighted the recent biological, epidemiological and therapeutic advances that have been made in the field of dermatology. The authors focus on the more important advances or summaries of findings, but this is not meant as a substitute for reading the conference proceedings and related references quoted in this article.

Updates from the British Association of Dermatologists 86th annual meeting, 4-7 July 2006, Manchester, U.K.

Here we provide a synopsis of the main clinical and research advances in clinical, epidemiological and biological dermatology that were presented at the meeting of the British Association of Dermatologists (BAD) held during 4-7 July 2006, in Manchester, U.K. Only the more important advances or summaries of findings are mentioned. The meeting was held at the Manchester International Conference Centre (Fig. 1). The annual dinner was held at Manchester Town Hall, in the Great Hall decorated with magnificent murals by Ford Madox Brown, with Dr Susan Burge as host.

Updates from the British Association of Dermatologists 85th annual meeting, 5-8 July 2005, Glasgow, U.K.

The conference highlighted the progress made in understanding recent biological, epidemiological and therapeutic advances in dermatology. Here we provide a synopsis of the main research and clinical findings presented at the meeting of the British Association of Dermatologists (BAD) held during 5-8 July 2005, in Glasgow, U.K., drawing attention to the most important advances and summaries. The BAD meeting was held at the Scottish Exhibition and Conference Centre, Glasgow (Fig. 1). The annual dinner was held in the wonderful setting of Stirling Castle, with Dr Robin Graham-Brown as host.

Updates from the British Association of Dermatologists 84th annual meeting, 6-9 July 2004, Belfast, U.K.

Herein is a synopsis of the main research and clinical findings presented at the British Association of Dermatologists meeting held during 6-9 July 2004, in Belfast, U.K. The conference highlighted the progress that has been made in understanding the increasing biological, epidemiological and therapeutic advances that have been made recently in the field of dermatology. The authors highlight the more important advances or summaries, but this is not meant as a substitute for reading the conference proceedings and related references quoted in this article.

Environmental effects and skin disease.

The skin is the largest organ in the body and one of its main functions is to protect the body from noxious substances, whether they are ultraviolet radiation, toxic chemicals or prolonged/repeated exposure to water. It is the level of exposure that determines if damage to the organism will result. The harm that can occur to the skin with sufficient exposure will be considered. Contact dermatitis, halogen acne, chemical depigmentation, connective tissue diseases and skin cancer are the conditions that will be covered in this chapter, as environmental exposure is important in their aetiologies. Systemic absorption will not be dealt with. Most environmental exposure to harmful substances will occur at work, but exposure may occur at home or during normal day-to-day activities.

Clinical examinations to validate self-completion questionnaires: dermatitis in the UK printing industry.

A self-completion questionnaire sent to 2600 Nottinghamshire members of the Graphical Paper and Media Union elicited a 62% response. Forty one per cent of respondents reported suffering a skin complaint at some time and 11% had a current skin problem on the hand. This paper reports the validation stage of the study. Samples of 45 'cases' of self-reported dermatitis and 60 'controls', who reported they had never suffered a skin complaint, were clinically examined. All 45 self-reported cases were clinically confirmed as dermatitis. Occupationally related irritant contact dermatitis (ICD) was diagnosed in 20 (44%); 26 (58%) complaints were thought to be induced or exacerbated by occupation. Of the controls, 21 (35%) were also diagnosed with a skin complaint, the majority being mild, with an occupational association in 17, the majority (15) being ICD. Sixteen ICD cases were patch tested resulting in positive reactions to colophony, neomycin, nickel and potassium dichromate (2 of each). Two cases of basal cell carcinoma on the face were also identified, of which the participants were unaware. Although there was no false positive self-reporting there was a considerable number of false negatives, demonstrating the importance of clinical validation of questionnaires relating to industrial skin disease. This study has highlighted the need for improvement in skin care provision in the printing industry.

Cross-reactivity patterns to budesonide.

Allergic contact dermatitis from topical corticosteroids is not uncommon. Budesonide has been included in the European standard series as a marker for corticosteroid allergy, though little is known of its cross-reactivity with other corticosteroids. Twelve patients previously positive to budesonide on patch testing were given further patch and intradermal tests to a range of corticosteroids. Six patients previously negative to budesonide on patch testing were used as a control group. Budesonide cross-reacts with hydrocortisone-21-sodium phosphate and triamcinolone acetonide. Patients positive to budesonide should therefore avoid hydrocortisone and triamcinolone acetonide. Patch testing, unfortunately, is an inaccurate method of determining cross-reactivity patterns among corticosteroids.

A randomized controlled trial of nurse follow-up clinics: do they help patients and do they free up consultants' time?

BACKGROUND: Nurse follow-up clinics have become increasingly popular in recent years. Their impact on service delivery within dermatology may be useful in relation to chronic diseases, where education and treatment concordance are important factors in disease management. OBJECTIVE: To assess the impact of providing a nurse follow-up clinic in addition to the normal service provided by the dermatology outpatient department at Queen's Medical Centre, Nottingham, and to obtain pilot data with which to inform future study design. METHODS: Newly referred patients aged >/= 14 years and with a diagnosis of either eczema or psoriasis were identified. In a randomized, parallel-group study with a follow-up period of 6 weeks, participants were randomized either to normal care, or to receive an additional session with a dermatology nurse specialist immediately after their consultation with the dermatologist. The primary outcome measure was change in quality of life at 6 weeks, as assessed by the Dermatology Life Quality Index (DLQI). Secondary outcomes comprised a comparison of patient knowledge at 6 weeks and the number of consultations (in secondary and primary care) that occurred during the 6-week follow-up period. RESULTS: Both groups improved by approximately 3 points on the DLQI scale after 6 weeks. The between-group difference was 0.27 (95% confidence interval - 2.3 to 2.8, P = 0.83). Patients who had seen the nurse were more likely to know how long they should apply treatment (P = 0.05). There was also a marked difference in patients' understanding of how to obtain a repeat prescription (P = 0.01) and from whom they could receive further support (P < 0.001). Following the addition of this service, 33% of follow-up appointments with a doctor were cancelled in the nurse intervention group. CONCLUSIONS: Dermatology nurses can add to a dermatology consultation and provide effective patient education and support in managing a skin condition. With this added service nurses could help to free up dermatologists' time, thus allowing them to see more new patients. Cost-effectiveness studies are now needed.

Type IV hypersensitivity reactions to natural rubber latex: results of a multicentre study.

BACKGROUND: Positive patch test reactions to natural rubber latex (NRL) have been interpreted as allergic or irritant by different groups. Additives to the NRL test solution have also caused positive reactions in previous studies. OBJECTIVES: Five centres of the British Contact Dermatitis Group conducted a prospective study on the prevalence of type IV hypersensitivity to NRL, using ammonia-preserved NRL solution for testing. PATIENTS AND METHODS: A total of 2738 consecutive patients were patch tested. Where clinically indicated, specific IgE was measured or a prick test done. RESULTS: Twenty-seven patients (1%) had a positive patch test reaction to NRL, which was considered to be allergic and of current relevance in 19 (70%) patients. Fourteen of these also had a positive prick test or specific IgE. Thirteen patients (48%) were male, 19 (70%) atopic and 13 (48%) had eczema on their hands. CONCLUSIONS: We conclude that delayed-type hypersensitivity to NRL is a problem for a proportion of patients with eczema, particularly on their hands, and that patch testing with ammonia-preserved NRL can be recommended to identify these patients. Patients with a positive patch test should be investigated for contact urticaria to NRL.