Group - Keloid

Abstract: Earlobe keloid can form after cosmetic ear piercing, trauma, or burns, and it poses several difficulties in treatment and distinctive cosmetic implications. Treatment methods for earlobe keloids include both surgical and nonsurgical methods. After excision of the earlobe keloid, healing by secondary intention, primary suture, skin graft, or local flap has revealed some disadvantages. The authors approached this problem with a new excision and covering method. The surgery was performed under local anesthesia. Skin over the keloid was dissected from the keloid mass as a flap, which they termed a...

Abstract: Extracellular matrix hyaluronan is prominent during wound healing, appearing at elevated levels early in the repair process. It is prevalent throughout the course of fetal wound healing, which is scar-free, but decreases late in adult wound repair, that is often marked by scarring. To determine whether aberrant hyaluronan metabolism is associated with the excessive scarring that characterizes keloids, cultured fibroblasts derived from keloids and from the dermis of normal human skin and scar were compared. Levels of hyaluronan in 48 h conditioned media of keloid-derived cultures were significa...

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Abstract: The biological mechanism underlying steroid therapy for treating keloids remains unclear. Analytical results demonstrated that topical intra-lesional steroid injections suppress vascular endothelial growth factor (VEGF) expression in keloid tissue and induce its regression in vivo. This study investigated whether glucocorticoid (dexamethasone) downregulates VEGF expression and hinders keloid fibroblast (KF) proliferation in keloid regression. Primary KF cultures were treated with various concentrations of dexamethasone, glucocorticoid receptor (GR) antagonist (mifeprostone, RU-486), VEGF-A ant...

Abstract: Keloids and hypertrophic scars result from excessive collagen deposition, the cause of which is not yet known. Unlike hypertrophic scars, keloids frequently persist at the site of injury, often recur after excision and always overgrow the boundaries of the original wound. There have been many trials to control keloids, but most of them have been unsuccessful. The authors propose a new surgical technique to treat keloids and name it keloid core extirpation. They excise the inner fibrous core from the keloid and cover the defect with a keloid rind flap, which is arterialized by the subcapsular v...

Abstract: Background: Keloids are characterized by excess collagen deposition within the dermis. Although the exact cause of the potentially overactive fibroblasts has yet to be elucidated, many etiological possibilities have been suggested. As fibroblasts originating from keloids appear to have an increased migration and proliferation rate, cell-signaling studies examining these factors may offer an opportunity to further our understanding of the pathogenesis of this disease. One of such cell-signaling messengers is the enzyme Ras-related C3 botulinum toxin substrate (RAC), which has never been investi...

Abstract: A technique is described using the epithelium over a keloid as a graft after excision of the keloid. Advantages of this procedure are availability of skin and avoidance of the danger of keloid formation in a distant donor site. Results in a series of five patients followed for five years were satisfactory in three.

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Abstract: AIMS: Keloid is characterized by excessive deposition of collagen, resulting from aberrant extracellular matrix (ECM) production and degradation. The aim was to investigate the role of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in pathological wound healing in keloids. METHODS AND RESULTS: Semiquantitative analysis of 60 keloid tissue samples and 25 mature scar tissue samples demonstrated significantly increased expression of MMP-2, TIMP-2 and TIMP-3 in keloids compared with mature scars. Within keloid regions, MMP-2 expression was significantly higher ...

Abstract: Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and development of pathological scarring. To examine the phenomenon of apoptosis and its involvement in the process of pathological scarring, we immunohistochemically quantified differential levels of expression of caspase-3 and -2, which are activated during apoptosis in vitro, in surgical resected scar tissues. We divided 33 cases of normally healed flat scars and 18 cases of pathological scars (15 cases of hypertrophic scars and 3 cases of keloid) into three groups (S1 = 40...

Abstract: Keloid disease (KD) is an abnormal form of scarring with a familial predisposition. Genetic studies have yet to identify the genes involved in KD. Transforming growth factor beta (TGF-beta) has multiple cellular activities including cellular proliferation, differentiation and extracellular matrix production. TGF-beta family members such as TGF-beta(1) and TGF-beta(2) are known to be involved in KD formation. However, we previously demonstrated a lack of association between common TGF-beta(1) and TGF-beta(2) polymorphisms and KD. Other studies have implicated TGF-beta receptors in KD pathogenes...

Abstract: BACKGROUND: Keloid scars represent a pathological response to cutaneous injury. Overproliferation of fibroblasts and overproduction of collagen characterize these abnormal scars. The pathology of these scars remains poorly understood. The role of epithelial-mesenchymal interactions in keloid pathogenesis and scar contracture has recently been explored. OBJECTIVES: To test our hypothesis that epithelial-mesenchymal interactions play a major role in modulating keloid scar contracture. METHODS: A coculture model was employed wherein keloid and normal keratinocytes were cocultured with keloid or n...

Abstract: OBJECTIVE: To investigate the relations between thymosin beta 4 and pathologic scars by comparing the mRNA levels of thymosin beta 4 in keloid, hypertrophic scar and normal skin. METHODS: The primary fibroblasts from the patients of keloid (KFB), hypertrophic scar (HFB) and normal skin (NFB, n=7) were cultured in vitro with tissue culture system. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay was used to assess the thymosin beta 4 mRNA levels in the tissues and fibroblasts obtained from the patients of three groups. RESULTS: The mRNA levels of thymosin beta 4 ...

Abstract: Keloids are characterized by the deposition of excessive extracellular-matrix collagen by abnormal fibroblasts in response to cutaneous injury. Studies to date have largely concentrated on the role of the keloid fibroblast in the pathogenesis of this lesion. Recent studies have highlighted the important concept of epithelial-mesenchymal interactions in normal skin biology. Extrapolating this to keloids in two recent serum-free in vitro studies, we demonstrated increased growth and proliferation, as well as induction of keloid-like collagen secretory characteristics in normal fibroblasts co-cul...

Abstract: Regulation of collagen gene expression was studied in keloids and fibroblast cultures established from keloid biopsies from 9 patients. The collagen concentration in keloid tissue was not different from that in normal skin. The activities of 2 enzymes catalyzing intracellular collagen biosynthesis, prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT) were significantly elevated in the keloids, the mean increase in the former enzyme being 5-fold and in the latter 3-fold with respect to the controls. The mean procollagen production rate in the keloid fibroblasts was at ...