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Kwang-Hyun Cho

Publications and source records attributed to Kwang-Hyun Cho.

5 recordsLinked to original sources
PubMed2003

Two types of ion channel formation of tolaasin, a Pseudomonas peptide toxin.

Tolaasin is a peptide toxin produced by Pseudomonas tolaasii and causes brown blotch disease of the cultivated mushrooms. Two types of ion channels were identified by the incorporation of tolaasin into lipid bilayer. The slope conductance of type 1 channel measured in the buffer containing 100 mM KCl was 150 pS with a linear current vs. voltage relationship. The type 2 tolaasin channel had two subconductance states of 300 and 500 pS. Both channels were inhibited by Zn(2+). Ion channel formations of tolaasin were concentration-dependent and single channel currents were successfully obtained at 0.6 unit tolaasin, 15.9 nM. The type 1 channel was obtained more frequently than the type 2 channel and the ratio of their appearance was approximately 4:1, respectively.

Agaricales↗
PubMed2002

Vitamin D receptor genotypes are not associated with clinical response to calcipotriol in Korean psoriasis patients.

Conflicting results have been reported on the association between BsmI restriction fragment length polymorphism (RFLP) at the vitamin D receptor gene (VDR) locus and the clinical response of psoriasis patients to calcitriol or calcipotriol therapy. We evaluated RFLPs of the VDR gene by analyzing the restriction pattern of polymerase chain reaction products in 55 Korean psoriasis patients receiving topical calcipotriol therapy, and evaluated the clinical response. Of the 55 patients, 43 completed the 8-week treatment protocol, and the response was evaluated as excellent in 9 patients, good in 20, and poor in 14. Thus, in our 43 patients BsmI and ApaI polymorphism in the VDR gene did not correlate with response to calcipotriol. The marked predominance of the b allele in the Korean population precludes the possibility that BsmI polymorphism is associated with clinical response to calcipotriol. The pattern of prevalence of the VDR genotypes in the Korean population is very different from that in Western populations. There were no differences in VDR genotype between controls and psoriasis patients at the BsmI site, but there were significant difference in terms of ApaI RFLP as previously reported. In conclusion, polymorphism analysis of the VDR gene with BsmI and ApaI restriction enzymes in psoriasis patients was not helpful in predicting clinical response to calcipotriol.

Adolescent↗
PubMed2002

Fibroblasts and ascorbate regulate epidermalization in reconstructed human epidermis.

Skin equivalent model provides a new investigating system to study the role of extracellular matrix and dermal factors such as collagen, basement membrane components and fibroblasts (Fb) which contribute to cell-cell and cell-matrix interactions. Although basement membrane factors is known to play an important role in epidermal differentiation and epidermal-matrix adhesion, comparative effects of these extracellular matrix and dermal factors on the reconstruction of epidermis are little known. In this study, we investigated effects of type I collagen (Coll I), type IV collagen plus laminin (LAM) coated Coll I (Coll IV+LAM), and human Fb enriched Coll I (Coll I+Fb) on epidermal reconstruction. When human keratinocytes were cultured on three different gels containing Coll I, Coll IV+LAM and Coll I+Fb, basal keratinocytes were cuboidal and perpendicular to the dermo-epidermal junction only in the gel containing Coll I+Fb. Proliferation marker expression was prominent and differentiation marker expression was similar with those of normal skin in the gel containing Coll I+Fb than in the other gel models. Since ascorbate is suspected to exert an effect as a modulator of proliferation and differentiation in keratinocytes, we tested the effects of ascorbate on human epidermis reconstruction. When 25 microg/ml ascorbate was added, disordered arrangement of epidermis was disappeared and differentiation marker expression was similar with its expression in normal skin. These data indicate that human Fb and a modulator of proliferation and differentiation such as ascorbate are essential for epidermalization in reconstructed epidermis.

Ascorbic Acid↗
PubMed2002

A case of multiple disseminated eruptive Spitz nevi.

Spitz nevus is usually a solitary lesion. However, multiple Spitz nevi do arise and can be divided into two variants, agminated (grouped) or disseminated. We report an interesting case of multiple disseminated eruptive Spitz nevi with an unusual feature. The appearance of most of the nevi resembled that of melanocytic nevi, and clinically it was impossible to distinguish these multiple disseminated eruptive Spitz nevi from eruptive melanocytic one.

Adult↗