Gelatin for purification and proliferation of primary keratinocyte culture for use in chronic wounds and burns.

OBJECTIVES: Human epidermal keratinocytes are currently established as a treatment for burns and wounds and have laboratory applications. Keratinocyte culture contamination by unwanted cells and inhibition of cell proliferation are barriers in primary keratinocyte culture. According to the recent literature, these cells are hard to culture. The present study was conducted to evaluate the efficacy of gelatin-coated surfaces in keratinocyte cultures. MATERIALS AND METHODS: After enzymatic isolation of keratinocytes from normal epidermis by trypsin, the cells were cultured on gelatin-coated flasks in serum-free medium. Another group of cells were cultured as a control group without gelatin coating. RESULTS: We showed positive effects of surface coating with gelatin on the primary culture of keratinocytes. Culture of these cells on a gelatincoated surface showed better proliferation with suitable morphology. By using gelatin, adhesion of these cells to the surface was more efficient and without contamination by small round cells. CONCLUSIONS: Successful primary culture of keratinocytes on a gelatin-coated surface may provide better yield and optimal number of cells for research and clinical applications.

Considerations in the improvement of human epidermal keratinocyte culture in vitro.

OBJECTIVES: Large-scale expansion of epidermal keratinocytes is essential in the application of these cells for severe burn treatment in patients. Therefore, this study was designed to evaluate various conditions in the expansion of human epidermal keratinocytes. MATERIALS AND METHODS: The epidermis was separated from the dermis of skin samples using dispase. The epidermis was trypsinized for keratinocyte isolation. Keratinocytes were cultured in various conditions, with or without a human dermal fibroblast feeder layer, mitomycin C treatment, and different culture media. RESULTS: Our results suggest that keratinocytes cultured on a human dermal fibroblast feeder layer were grown for several passages. Extensive deformation and rapid deterioration were observed in the cultured cells without a feeder layer and in serum-free medium. CONCLUSIONS: Human dermal fibroblasts treated with mitomycin C can provide optimal conditions for proliferation of keratinocytes.

Effect of CD40 silenced dendritic cells by RNA interference on mice skin allograft rejection.

AIM: Tolerogenic dendritic cells (DCs) play a critical role in inducing and maintaining tolerance. CD40 is a member of tumor necrosis factor receptor super family and is a potent T-cell costimulatory molecule. Therefore, in this study we evaluated the effect of CD40 silenced DCs by RNA interference on mice skin allograft rejection. MATERIALS & METHODS: Skin transplantation was performed from C57BL/6 to BALB/c mouse. Skin allograft recipients were assigned to four groups (n = 5). CD40 downregulated DCs were injected to the BALB/c mice intravenously 7 days before transplantation. Then, graft survival time, Treg generation, CD4(+) and CD8(+) T cells infiltration and cytokine levels in serum of this group were compared with those of untreated and cyclosporine groups. RESULTS: In comparison with untreated group, BALB/c mice injected with CD40 siRNA transfected DCs showed an increased graft survival time, Treg cells, IL-4 and IL-10 cytokine levels as well as decreased number of intragraft CD4(+) and CD8(+) T cells. IFN-γ and IL-12 secretion were diminished, too. CONCLUSION: Taken together, these data demonstrate that downregulation of CD40 in DCs can expand Treg cells and increase skin allograft survival.

Lipofibromatosis accompanied by several congenital anomalies, report of a rare case.

Lipofibromatosis is a rare tumor of infancy, which has been reported about 10 years ago, and since then very few reports have been published. This tumor has been reported in association with congenital anomalies such as macrosyndactyly, but there is no report of multiple congenital anomalies with lipofibromatosis in the English literature as far as our knowledge goes. Herein, we report a case of this tumor associated with syndactyly, bilateral complete cleft lip and palate, trigonocephaly, and atrial septal defect.

Merkel cell carcinoma in a 17-year-old boy, report of a highly aggressive fatal case and review of the literature.

Merkel cell carcinoma is a rare tumor frequently involving the skin with an aggressive behavior and fatal outcome. It occurs mostly in the caucasian race between 60-80 years of age and it is rare in children. Herein we report our experience with a highly aggressive fatal Merkel cell carcinoma in an immunocompetent 17-year-old boy. Its characteristics and treatment modalities will be also discussed.

Early excision and skin grafting versus delayed skin grafting in deep hand burns (a randomised clinical controlled trial).

INTRODUCTION: Early excision and grafting (E&G) of burn wounds has been reported to decrease hospital stay, hospital costs and septic complications, and some purport reduced mortality while decreasing hospital costs. In today's practice, all burn wounds unlikely to achieve spontaneous closure within 3 weeks are excised and grafted. Early studies did not demonstrate dramatic differences in cosmetic or functional results. This is particularly true with burns of the face, hands and feet. In this study, early excision and skin grafting was compared with delayed skin grafting in deep hand burns. MATERIALS AND METHODS: From September 2006 to February 2008, 50 patients with hand burns and average burn size less than 30% total body surface area (TBSA) deep second- and third-degree were randomly divided into early E&G group (group I) and delayed grafting group (group II). Gradual and careful limb and digit range of motion was started on about 10th-14th postoperative day. We used a questionnaire based on the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire to evaluate final functional outcome. Further, hypertrophic scar formation, contracture and deformities were followed and managed accordingly. RESULTS: The most common site of involvement was the metacarpophalangeal (MCP) joint with frequency of 39% and 40% in groups I and II, respectively. There were no statistically significant differences between both groups regarding deformity severity, scar formation, sensation, major activities and overall satisfaction. DISCUSSION: In treating burns of the hand, the primary goal should always be to restore the functionality of the hand. Although early surgery shortens the healing time and lessens the hospital stay, our results did not show any significant difference between these two methods regarding the function, scar formation, daily activity limitation and overall satisfaction.

Proteinase-activated receptor-2 expression in basal and squamous cell carcinomas compared with normal skin.

Proteinase-activated receptor-2 (PAR-2) is a transmembrane G-protein expressed in many normal tissues and overexpressed in several cancer cell lines. It contributes to metastasis, promotes epidermal growth factor receptor proliferation, angiogenesis and tumor progression in many carcinomas. The purpose of this study was to investigate the expression of PAR-2 in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in comparison with that of normal skin. Immunohistochemical (IHC) expression of PAR-2 was examined using paraffin-embedded sections from 30 BCCs, 30 SCCs and also 30 normal sun-exposed skin specimens. PAR-2 was expressed in all specimens of SCC and normal skin. In marked contrast, all BCC specimens had negative IHC staining. Given the important role of PAR-2 in angiogenesis and metastasis, our finding can explain the far less aggressive behavior of BCC as compared with SCC.