摘要:

Calmodulin, a major calcium-binding protein, is important in the regulation of cell proliferation. In human keratinocytes we found that culture confluence was accompanied by a decrease in calmodulin content. Ciclosporin A, 1–10 μg/ml, was found to inhibit the proliferation of the cells but did not affect their calmodulin content as measured by bioassay or radioimmunoass

ISSN:1660-5527    

DOI:10.1159/000210864

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The cytotoxic effects of a range of antiseptic agents were examined on cultured human fibroblasts and basal keratinocytes and compared to those on a transformed keratinocyte line (SVK 14 cells). Cells were exposed to chlorhexidine, hydrogen peroxide and sodium hypochlorite for 15 min and cell viability was assessed 24 h later with a colorimetric assay which utilizes the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). At concentrations recommended for wound cleansing all agents produced 100% killing of all cell types. The results show that fibroblasts and keratinocytes, cells which are fundamental to the wound healing process are equally sensitive to the effects of the antiseptic agents tested, and are highly susceptible to the effects of free-chlorine containing agents. These observations are of particular importance to the use of cultured keratinocytes (culture grafts) to enhance wound healing; the application of antiseptics to such wounds is contraindicated. All three cell types tested showed similar susceptibilities to the agents tested. These findings suggest that the transformed cell line, which has the advantage of immortality and ready availability, can replace fibroblasts and keratinocytes in studies designed to investigate the adverse effects of antiseptic agents in vitro. Comparison of the ED5o concentration for each agent on all cell types to the standard use concentration produced a ranking order of toxicity which showed chlorhexidine to be the least toxic agent and sodium hypochlorite the most. These findings are in agreement with recent in vivo studies on wound healing which have shown that chlorhexidine does not inhibit wound healing but that sodium hypochlorite inhibits both the formation of granulation tissue and re-epithelialization.

ISSN:1660-5527    

DOI:10.1159/000210865

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The effect of tiacrilast, a mast cell mediator-release inhibitor, was studied in dinitrofluorobenzene-induced allergic and croton oil- or dimethyl sulfoxide-induced irritant murine contact dermatitis. At 1 % concentration, the compound significantly reduced the ear swelling in both allergic and irritant dermatitis and preserved the mast cell architecture on histopathology. These findings suggest that mast cells participate in the elicitation of murine contact dermatitis.

ISSN:1660-5527    

DOI:10.1159/000210866

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

A clinical therapy for psoriasis, a hyperproliferative disease of the skin, utilizes topical application of crude coal tar sometimes followed by UV irradiation (Goeckerman therapy). To investigate the formation of covalent DNA adducts resulting from this therapy, skin biopsies were obtained from treated patients and controls. Indirect immunofluorescence staining with antisera generated against benzo(a)pyrene diol epoxide-modified DNA was used to investigate cell-specific localization of adduct formation. Specific nuclear staining was detected in the epidermal cells of all biopsies from treated patients but not from control biopsies obtained from untreated individuals. 32P postlabeling of DNA isolated from the biopsies was used to determine the spectrum of hydrophobic adducts present. A pattern of multiple adducts was detected in the samples obtained from the treated patients but not from controls.

ISSN:1660-5527    

DOI:10.1159/000210867

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Human skin showed high activity of cytosolic N-acetylation for two typical arylamine substrates, p-aminobenzoic acid (PABA) and 2-aminofluorene (AF). Their specific activities (per milligram protein basis) were comparable with those of hamster skin, which is known to have high acetylating capacities for several arylamines. In hamster skin, two other types of acetylation, N-hydroxy-4-acetylaminobiphenyl-dependent N-acetylation of AF (NN´-acetyltransfer) and acetyl CoA-dependent O-acetylation of 2-hydroxyamino-6-methyl-pyrido[1,2-α:3´,2´-d]irnidazole (O-acetylation) also occurred, but no appreciable activity was observed in human skin for these two reactions. These results suggest that arylamines including prohaptens and carcinogens may be modified metabolically through N-acetylation at the first contact site, human skin. In addition, a good correlation was observed for N-acetylations of PABA and AF in human skin, implying that these N-acetylations may be catalyzed by the same or a closely related enzyme in human s

ISSN:1660-5527    

DOI:10.1159/000210868

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:1660-5527    

DOI:10.1159/000210869

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:1660-5527    

DOI:10.1159/000210870

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:1660-5527    

DOI:10.1159/000210871

出版商:S. Karger AG    

年代:1990

数据来源: Karger