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Excisional Wounds (excisional + wound)
Selected AbstractsNitric oxide synthesis inhibition alters rat cutaneous wound healingJOURNAL OF CUTANEOUS PATHOLOGY, Issue 7 2006Thaís P. Amadeu Background:, Nitric oxide (NO) is an important molecule that participates in wound repair, but its effects on cutaneous wound healing are not well understood. The aim of this study was to investigate the effects of NO synthesis blockade on rat cutaneous wound healing by the administration of NG -nitro- l -arginine methyl ester (l -NAME), a non-selective inhibitor of NO synthases. Methods:, NO synthesis was inhibited by administration of l -NAME (20 mg/kg/day) in drinking water. An excisional wound was done, and the animals were killed 7, 14, and 21 days later. Wound contraction and blood pressure were evaluated. The lesion and adjacent skin were formalin fixed and paraffin embedded. Mast cells were quantified, and vessels were evaluated using stereological methods. Results:,l -NAME-treated animals presented delayed wound contraction, alterations in collagen organization, and neoepidermis thickness. The inhibition of NO synthesis increased mast cell migration 7 days after wounding, but decreased 21 days after wounding. Volume density of vessels was decreased in l -NAME-treated animals, 21 days after lesion. Surface density of vessels was frequently smaller in l -NAME-treated animals than in controls. Conclusion:, The blockade of NO synthesis impaired cutaneous wound healing, acting in early and late phases of wound repair. [source] Comparative analysis of global gene expression profiles between diabetic rat wounds treated with vacuum-assisted closure therapy, moist wound healing or gauze under suctionINTERNATIONAL WOUND JOURNAL, Issue 5 2008Kathleen L Derrick Abstract How differential gene expression affects wound healing is not well understood. In this study, Zucker diabetic fatty (fa/fa) male inbred rats were used to investigate gene expression during wound healing in an impaired wound-healing model. Whole genome microarray surveys were used to gain insight into the biological pathways and healing processes in acute excisional wounds treated with vacuum-assisted closure (V.A.C.®) Therapy, moist wound healing (MWH) or gauze under suction (GUS). Global gene expression analyses after 2 days of healing indicated major differences with respect to both number of genes showing fold changes and pathway regulation between the three different wound treatments. Statistical analysis of expression profiles indicated that 5072 genes showed a >1·6-fold change with V.A.C. Therapy compared with 3601 genes with MWH and 3952 genes with GUS. Pathways and related genes associated with the early phases of wound healing diverged between treatment groups. For example, pathways involving angiogenesis, cytoskeletal regulation and inflammation were associated with elevated gene expression following V.A.C. Therapy. This study is the first to assess wound healing by whole genome interrogation in a diabetic rat model treated with different healing modalities. [source] A coordinated approach to cutaneous wound healing: vibrational microscopy and molecular biologyJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 5b 2008K. L. Andrew Chan Abstract The repair of cutaneous wounds in the adult body involves a complex series of spatially and temporally organized processes to prevent infection and restore homeostasis. Three characteristic phases of wound repair (inflammation, proliferation including re-epithelialization and remodelling) overlap in time and space. We have utilized a human skin wound-healing model to correlate changes in genotype and pheno-type with infrared (IR) and confocal Raman spectroscopic images during the re-epithelialization of excisional wounds. The experimental protocols validated as IR images clearly delineate the keratin-rich migrating epithelial tongue from the collagen-rich wound bed. Multivariate statistical analysis of IR datasets acquired 6 days post-wounding reveal subtle spectral differences that map to distinct spatial distributions, which are correlated with immunofluorescent staining patterns of different keratin types. Images computed within collagen-rich regions expose complementary spatial patterns and identify elastin in the wound bed. The temporal sequence of events is explored through a comparison of gene array analysis with confocal Raman microscopy. Our approach demonstrates the feasibility of acquiring detailed molecular structure information from the various proteins and their subclasses involved in the wound-healing process. [source] Rapid Control of Wound Infections by Targeted Photodynamic Therapy Monitored by In Vivo Bioluminescence Imaging,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2002Michael R. Hamblin ABSTRACT The worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. In this study we report on the first use of a photochemical approach to destroy bacteria infecting a wound in an animal model. Following topical application, a targeted polycationic photosensitizer conjugate between poly- l -lysine and chlorine6 penetrated the Gram (,) outer bacterial membrane, and subsequent activation with 660 nm laser light rapidly killed Escherichia coli infecting excisional wounds in mice. To facilitate real-time monitoring of infection, we used bacteria that expressed the lux operon from Photorhabdus luminescens; these cells emitted a bioluminescent signal that allowed the infection to be rapidly quantified, using a low-light imaging system. There was a light-dose dependent loss of luminescence in the wound treated with conjugate and light, not seen in untreated wounds. Treated wounds healed as well as control wounds, showing that the photodynamic treatment did not damage the host tissue. Our study points to the possible use of this methodology in the rapid control of wounds and other localized infections. [source] Optical Coherence Tomography: A Noninvasive Method to Assess Wound ReepithelializationACADEMIC EMERGENCY MEDICINE, Issue 5 2007Adam J. Singer MD BackgroundAccurate assessment of wound healing may require invasive tissue biopsies, limiting its clinical usefulness in humans. Optical coherence tomography (OCT) is a novel, high-resolution method using light reflection to obtain noninvasive cross sectional imaging of biological tissues. ObjectivesTo evaluate the utility of OCT for assessing wound reepithelialization in a porcine model. MethodsThe authors conducted an animal study with two domestic pigs. Excisional cutaneous wounds were created over the ventral surface of the animals using an electric dermatome set at a depth of 600 ,m. The wounds were excised two or three days later and precisely marked to guide initial OCT and subsequent tissue slicing and microscopy. Comparing hematoxylin and eosin,stained histologic sections and the corresponding OCT images from each tissue sample permitted identification of the correlative micromorphology. Scatter and Bland,Altman plots were used to present the data. The primary measure of agreement was the standard deviation of the pairwise differences in percent reepithelialization between OCT and histology together with a 95% confidence interval. ResultsIn normal skin, the epidermis was characterized by a thin, bright layer indicating a high degree of light scattering on OCT. The dermis below was characterized by a thicker, darker area indicating less scattering of light. All fresh excisional wounds lacked an outer bright layer of epidermis immediately after injury. At days 2 and 3, the wounds were partially reepithelialized. A new bright layer with intense light scattering was present on OCT corresponding to the neoepidermis on hematoxylin and eosin,stained sections. The correlation between percent reepithelialization measured with OCT and histology was 0.66 (p < 0.001), and the standard deviation of the differences was 11.0% (95% confidence interval = 8.4% to 16.1%). ConclusionsOCT accurately detects the presence or absence of the epidermal layer of skin, allowing noninvasive tracking of wound reepithelialization. [source] | ||||||||||