Hypertrophic versus non hypertrophic scars compared by immunohistochemistry and laser confocal microscopy: type I and III collagens.

Although dermal collagens appear increased in hypertrophic scars, this has not been tested in tissue samples using objective methods. We compared the expression of types I and III collagen in hypertrophic and non hypertrophic scars at 6-12 and 18-24 months after burn using a quantitative method. Among 17 patients with extensive burns, 3 patients had acute scars, 8 had hypertrophic or non hypertrophic scars at 6-12 months after burn and 6 had hypertrophic or non hypertrophic scars at 18-24 months after burn. After clinical assessment of scars using the Vancouver scale, immunohistochemistry for types I and III collagens was performed. Images were captured with a laser scanning confocal microscope and the relative amounts of types I and III collagens were determined in superficial and deep dermis. The effects of time and scar type were assessed using two-way analysis of variance (ANOVA) and Tukey's test. Collagen III scar/normal ratios were higher in hypertrophic scars at both time points (P = 0.05). There were no differences in collagen I scar/normal ratios. Large variation was observed in scars during the acute phase regarding the expression of collagens. Easily accessed by immunohistochemistry and confocal microscopy, type III collagen deposition may help in determining scar phenotype, differentiating hypertrophic and non hypertrophic scars.

Transfection of cells attached to selected cell based biosensor surfaces.

Mammalian cell attachment studies were conducted on a variety of common microchip surfaces for potential use in cell based biosensors. COS-7 cell attachment to Au, Pt or ITO, per unit area was greater than to SiO(2) surfaces. The number of cells that would attach was essentially maximized 3 h after cell seeding. HL-1 cells attached more readily to surfaces precoated with fibronectin, but by 3 h equivalent number of cells had attached independent of fibronectin precoating. Inclusion of serum in media during the initial period of attachment decreased the number of COS-7 cells attached to SiO(2) surfaces, but no dependence on serum was seen for ITO surfaces. The number of cells attached per unit area varied with the composition of the surface. However, no differences were observed in the percentage of cells transfected with a green fluorescent protein gene, or in the level of reporter gene expression over the population of transfected cells on ITO, SiO(2), Pt, Ag, or Au surfaces. Similar FACS analysis of transfected Hep G2 cells revealed lower levels of both transfection efficiency and levels of GFP fluorescence. Hep G2 cells plated on Ag did not remain attached for analysis, but there were no significant differences between tissue culture plastic and the other biosensor surfaces in the percentage of cells transfected. This suggests that, in general, cells will attach to the various conducting and nonconducting biosensor surfaces studied and will provide comparable data in reporter gene expression assays.

Collagen XVIII and fibronectin involvement in bullous scleroderma.

BACKGROUND: Endostatin, an anti-angiogenic C-terminal fragment of collagen XVIII, has been recently reported to play a role in scleroderma pathogenesis, but collagen XVIII immunohistochemistry in scleroderma skin has still not been performed. Bullous scleroderma, a rare form of scleroderma, may have altered angiogenic and lymphangiogenic characteristics. OBJECTIVE: Our aim is to report a rare case of bullous scleroderma, studying the presence of fibronectin and collagens type I, III and XVIII in sclerodermic skin. METHODS: We describe the progression of bullous scleroderma in a 67-year-old patient since the first symptoms. Histological and immunohistochemical aspects of skin biopsies are compared to normal skin from a patient without scleroderma and are correlated with the pathogenesis of the disease. Indirect immunofluorescence measured by laser confocal microscopy allows quantitative determination of fibronectin and collagens type I, III and XVIII. RESULTS AND CONCLUSIONS: Dermo-epidermal cleavage, fibrosis and inflammation are the main histological findings. The dermal distribution and amounts of collagens and in the scleroderma patient are similar to normal skin. Conversely, both fibronectin and collagen XVIII are increased in scleroderma skin, suggesting their involvement in the pathogenesis of bullous scleroderma.