Activation Pattern of Langerhans Cells in the Afferent and Efferent Phases of Contact Hypersensitivity

Langerhans cells are MHC class II (Ia) positive antigen- presenting cells that play a crucial role in the induction of contact hypersensitivity (CHS). The topical application of a hapten modifies the cell surface moieties of Langerhans cells, and activates Langerhans cells to increase their size and Ia intensity. The haptenated and activated Langerhans cells emigrate from the epidermis and thus the in situ density of Langerhans cells usually decreases during 24-48h after the hapten application in CHS. To determine whether the early activation pattern of Langerhans cells is different between the afferent phase and the efferent phase of CHS, we compared the density and morphologic changes of Langerhans cells in CHS to trinitrochlorobenzene using nonsensitized and sensitized mice. We found that the application of a hapten induces more significant enlargement of Langerhans cell size in the afferent phase than in the efferent phase, whereas the reduction of Langerhans cell density is more marked in the efferent than in the afferent phase of CHS. Moreover, topical immunosuppressive drugs inhibit the in situ activation of Langerhans cells

Matrix metalloproteinase-1 up-regulation by hepatocyte growth factor in human dermal fibroblasts via ERK signaling pathway involves Ets1 and Fli1

In this study, we clarified the molecular mechanism(s) underlying the regulation of matrix metalloproteinase (MMP)-1 gene by hepatocyte growth factor (HGF) in cultured human dermal fibroblasts. HGF induced MMP-1 protein as well as mRNA at a transcriptional level via extracellular signal-regulated kinase (ERK) signaling pathway. The region in the MMP-1 promoter mediating the inducible responsiveness to HGF, defined by the transient transfection analysis of the serial 5′ deletion constructs, contained an Ets binding site. Mutation of this Ets binding site abrogated the HGF-inducible promoter activity. Ets1 up-regulated the expression of MMP-1 promoter activity, whereas Fli1 had antagonistic effects on them. After HGF treatment, the protein level and the binding activity of Ets1 was increased and those of Fli1 was decreased, which were canceled by PD98059. These results suggest that HGF up-regulates MMP-1 expression via ERK signaling pathway through the balance of Ets1 and Fli1, which may be a novel mechanism of regulating MMP-1 gene expression

Visualization based on grid computing for large-scale volume data

第10回IEEE広島支部学生シンポジウム(HISS), ポスター ; 開催場所:広島 ; 開催日:2008年11月21-23

Visualization based on grid computing for large-scale volume data

第10回IEEE広島支部学生シンポジウム(HISS), ポスター ; 開催場所:広島 ; 開催日:2008年11月21-23

Percutaneous Absorption Of Betamethasone 17-Benzoate Measured By Radioimmunoassay

Percutaneous absorption was studied in patients following topical application of betamethasone 17-benzoate cream and gel with occlusion by means of a sensitive and specific radioimmunoassay method. Concentrations of betamethasone 17-benzoate in plasma were between 0.3 and 5 ng/ml, indicating approximately 0.05 to 0.3% of the steroid applied to the skin was detected in plasma. Plasma betamethasone 17-benzoate levels increased in proportion to the amount of the steroid applied to the skin. High correlation between plasma betamethasone 17-benzoate levels and percent inhibition of plasma cortisol was also observed. Approximately 3 ng/ml levels of betamethasone 17-benzoate in plasma induced 90% inhibition of plasma cortisol. The data suggest that betamethasone 17-benzoate in gel base was more readily absorbed than in cream base