Journal of burns and wounds最新文献

Objective: The purpose of this article is to familiarize the reader with the issue of bone loss that accompanies severe burn injury. Why is this important? How does it happen? How can we treat it?

Methods: The published findings on this subject are reviewed and integrated into a conceptual framework.

Results: Bone loss occurs quickly following a severe burn, is sustained, and increases the risk of postburn fracture. The likely mechanisms responsible are the increase in endogenous glucocorticoid production resulting from the stress response and resorptive cytokines resulting from the systemic inflammatory response and likely aggravated by progressive vitamin D deficiency. Calcium metabolism is also disrupted as the patients develop hypocalcemic hypoparathyroidism likely due to an upregulation of the parathyroid calcium-sensing receptor, possibly due to inflammatory cytokine stimulation. Treatment is achieved by use of anabolic agents and vitamin D supplementation. Studies of acute administration of the antiresorptive agent pamidronate are also promising.

Conclusion: Postburn bone loss should be looked for in patients with a burn injury of 40% or greater total body surface area. The cause is inherent to the adaptive mechanisms following burn injury. Methods are available to treat this condition.

Objective: In an attempt to find a better treatment for bacterial infections and burn wounds, various semisolid formulations containing 5% w/w of norfloxacin were prepared and evaluated for physicochemical parameters, in vitro drug release through cellophane membrane, antimicrobial activity, and burn wound healing properties. The prepared formulations were compared with silver sulfadiazine 1% cream, USP.

Methods: Various semisolid formulations were prepared with different bases like Carbopol, polyethylene glycol, and hydroxypropylmethyl cellulose, using standard procedures. The antimicrobial activity of these semisolid norfloxacin formulations, against various strains of aerobic and anaerobic microorganisms, was evaluated by using a standard cup-plate method. The wound healing property was evaluated by measuring the wound contraction and expressed as percentage of contraction of original wound size for each animal group.

Results: Antimicrobial activity of norfloxacin semisolid formulations was found to be equally effective against both aerobic and anaerobic bacteria in comparison to a formulation of silver sulfadiazine 1% cream, USP, available on the market.

Conclusion: The burn wound healing property of the prepared norfloxacin semisolid formulations was found to be in good agreement with silver sulfadiazine 1% cream, USP, available on the market.

Objective: The objective of this study was to observe the effects of cell culture on cellular polarity in cardiomyocytes as influenced by cytoskeletal proteins.

Methods: Cardiomyocytes from adult and neonatal rats were isolated and grown on 2 different extracellular matrices--laminin and a complex, fibroblast-derived extracellular matrix, cardiogel. The location of a number of proteins was visualized by means of fluorescence deconvolution microscopy, using specific fluorescent probes for alpha-adrenergic receptors, beta-adrenergic receptors, the sarcolemmal L-type calcium channel, and the sodium + potassium adenosine triphosphatase pump protein. Intracellular migration of these proteins during the first 4 days of culture was followed and microscopic stacked images were reconstructed. A fluorescein isothiocyanate-labeled probe for actin was used to ensure that cardiomyocytes were being examined, based on protein patterns.

Results: We examined 2 types of myocyte: freshly isolated neonates and cultured adult cardiomyocytes that undergo dedifferentiation. Initial, perinuclear clumping (endoplasmic reticulum/Golgi-associated) of the probes with an ensuing spread to the cytoplasm and periphery, accompanied by a better organization and more rapid response to biochemical stimuli, was seen on the complex matrix.

Conclusions: A complex matrix overcomes cell polarity at a faster rate than myocytes cultured on a simple matrix, although both culture matrices were able to support cell growth and differentiation, and single-layer cultures are a good method by which structural and biochemical data can be obtained. The use of a native, complex matrix is preferable to employing a simple, single protein, although temporal aspects of cell growth must be considered regarding the particular aspect of the cell structure development/biochemical pathways that the researcher intends focusing on.

Objective: Burn wound depth is a significant determinant of patient treatment and morbidity. While superficial partial-thickness burns generally heal by re-epithelialization with minimal scarring, deeper wounds can form hypertrophic or contracted scars, often requiring surgical excision and grafting to prevent a suboptimal result. In addition, without timely intervention, more superficial burn wounds can convert to deeper wounds. As such, the rapid and accurate assessment of burn wound depth is a priority in treating burn-injured patients. The object of this article is to review current research on modalities useful in the assessment of burn wound depth with emphasis on the relative costs and benefits of each technique.

Methods: PubMed and Cochrane computerized databases were used for data retrieval, using the search terms "burns," "burn wounds," "burn depth," "burn depth measurement," and "burn depth progression." In addition, bibliographic references from prior reviews of burn depth were reviewed. All peer-reviewed, English-language articles relevant to the topic of burn depth measurement were reviewed, including those focusing on animal and human populations. Where appropriate, conclusions drawn from review articles and expert analyses were included.

Results: Although bedside evaluation remains the most common modality of diagnosing the depth of burn wounds, recent technological advances have broadened the scope of depth assessment modalities available to clinicians. Other depth assessment techniques include biopsy and histology, and perfusion measurements techniques such as thermography, vital dyes, indocyanine green video angiography, and laser Doppler techniques.

Conclusion: Of the depth assessment modalities currently used in clinical practice, LDI and ICG video angiography offer the best data-supported estimates of accuracy. Until the future of new modalities unfolds, a combination of clinical evaluation and another modality--thermography, biopsy, or, ideally, ICG video angiography or LDI--is advised to best assess the depth of acute burn wounds.

Objective: The objective of this article is to present and discuss the clinical characteristics of TEN (Toxic Epidermal Necrolysis) and GVHD (Graft Versus Host Disease) following orthotopic liver transplantation.

Methods: Recent experience with a patient who suffered a fatal desquamation syndrome within weeks of liver transplantation provides the basis for a discussion of differential diagnosis of these two conditions.

Results: TEN and GVHD demonstrate similar clinical presentations as well as etiology (CD8+ lymphocyte attack on epithelial surfaces). This case demonstrates the difficulty in distinguishing between these two conditions in this particular patient.

Conclusions: Advances in the understanding and treatment of one of these disease states may provide therapeutic insights into the other.

Objective: This study focuses on the growth-promoting and migration-enhancing role that Clostridial collagenase plays in vitro and in vivo.

Methods: For in vitro studies, biosynthesized extracellular matrices were treated with purified Clostridial collagenase, nonspecific proteases, or buffer controls. Keratinocytes were subsequently plated upon these matrices in the presence or absence of Clostridial collagenase and/or heparin-binding epidermal-like growth factor, and cell proliferation and migration were quantified. To examine the effects of Clostridial collagenase in vivo, we performed a double-blind study of full-thickness wounds on the backs of Yucatan Micropigs, testing the effects of purified Clostridial collagenase, Regranex (PDGF-BB), and Solosite (carboxymethyl cellulose) on wound healing.

Results:

In vitro studies: Matrix pretreatment with Clostridial collagenase stimulates a 2-fold increase in proliferation and postinjury migration; when Clostridial collagenase and/or heparin-binding epidermal-like growth factor are added to the growth media, there is an additional doubling of growth and migration, yielding approximately 5-fold enhancement of keratinocyte proliferation and migration. Papain-urea treatment under similar conditions results in a 50% decrease in cell number over a 1-week time course. In vivo studies: By all parameters measured, including granulation tissue formation, inflammation, re-epithelization, and time to wound closure, purified Clostridial collagenase was superior (analysis of variance, P > .05) to other treatments tested.

Conclusion: On the basis of these findings, we concluded that Clostridial collagenase stimulates keratinocyte cellular responses to injury in vitro and may represent a novel therapeutic approach for promotion of wound healing in vivo.

Objective: The aim of this study was visualization and localization of the human antimicrobials human beta defensins 1, 2, and 3, neutrophil defensin alpha (human neutrophil peptide), and the cathelicidin LL-37 in normal and burned skin, and determination of the cell types in which these antimicrobials were localized.

Methods: Tissue sections were probed with antimicrobial antibodies, tagged with fluorescently labeled secondary antibodies, and subjected to fluorescence deconvolution microscopy and image reconstruction. Images were generated by stacking multiple-section scans, which were then volume rendered by rotating stacks 360 degrees about an axis, or modeled in 3 dimensions.

Results: This technique yields a definitive image, providing a rapid basis for further quantification and manipulation from a full 3-dimensional aspect. In normal skin, human beta defensin-1 was localized to the perinuclear region of keratinocytes; human beta defensin-2 was primarily localized to the stratum germinativum; human beta defensin-3 was found in dendritic cells of the stratum spinosum; human neutrophil peptide was randomly distributed in the papillary dermis; and LL-37 was concentrated in the stratum corneum and along ducts. In burned skin, in which keratinocytes are lost or destroyed, human beta defensin-1 was present in dermal glandular structures including hair shafts; human beta defensin-2 and human beta defensin-3 were found in the remaining keratin layers and glands of the lower dermis; human neutrophil peptide was primarily localized to hair shafts, though visible in residual keratin layers; and LL-37 was evident in very high concentrations in the epithelium of sweat ducts.

Conclusion: We conclude via this technique that cells in the lower dermal and subdermal regions of burned skin synthesize antimicrobials after burn injury, and maintain something of a barrier against infection. This methodology is discussed and explained in this article.

Objective: The purpose of this report is to present the results of a preliminary treatment regimen for hypertrophic scars combining topical 2% salicylic acid cream (Avosil) with an overlay of hydrogel dressing (Avogel).

Methods: The study group consisted of 3 patients with symptomatic hypertrophic scars: 2 presternal and 1 on the inner thigh. Scars were divided into 3 equal-size areas: (1) untreated control, (2) hydrogel alone, and (3) 2% salicylic acid with hydrogel cover. Treatments were applied every 8 to 12 hours and a Velcro appliance was employed to cover the area during treatment. The total length of treatment was 60 days.

Results: At the end of the 60-day treatment protocol, the area treated with 2% salicylic acid and hydrogel was asymptomatic. In contrast, the hydrogel-treated and untreated control areas remained erythematous and symptomatic for burning pain and pruritus.

Conclusion: This small study suggests the efficacy of combined salicylic acid and hydrogel therapy in the treatment of hypertrophic scars. More extensive studies of scar treatment with salicylic acid and hydrogel are needed. These studies must be larger in scope to carefully document the spectrum of patient responses and should include methods for evaluating alterations in the levels of different inflammatory mediators.

Objective: This article reports the first application of subatmospheric pressure management to a deep, partial-thickness human thermal burn.

Methods: After cleaning the wound, the decision was made to treat the hand and distal forearm with subatmospheric pressure (V.A.C., KCI, Inc, San Antonio, Tex). The sponge was applied directly to the burned skin without additional interface at approximately 6 hours after injury. The dressing was maintained at a continuous negative pressure of 125 mm Hg over the next 40 hours, with interruption only for routine clinical evaluation at 5, 16, and 24 hours after initiation of treatment. This was accomplished by opening the dressing without completely changing it. The treatment was tolerated well by the patient, requiring no excessive pain medication. After the subatmospheric pressure treatment was stopped, the wound appeared to be of indeterminate depth and the patient was started on twice daily applications of silver sulfadiazine.

Results: The clinical impression at this time was that the hand burn had not progressed but had stabilized and had minimal edema. He was followed as an outpatient and returned to work by 8 weeks. At approximately 4 weeks postinjury, his skin not only was functional but also appeared more normal, with less hyperemia than adjacent areas treated with topical antibacterials.

Conclusion: The present case does not prove that subatmospheric pressure treatment prevents burn wound progression. However, when combined with the previously reported laboratory studies it suggests the need for further research. Currently, a prospective, randomized, blinded, controlled multicenter trial is underway to evaluate the clinical importance of these observations.