Biomedical subjects

C P Choi

Publications and source records attributed to C P Choi.

3 recordsLinked to original sources

PubMed2006

The effect of narrowband ultraviolet B on the expression of matrix metalloproteinase-1, transforming growth factor-beta1 and type I collagen in human skin fibroblasts.

BACKGROUND: Ultraviolet (UV) irradiation induces chronic skin diseases, such as skin cancer and photoageing, and the mechanisms of this skin damage are associated with the upregulation of matrix metalloproteinases (MMPs) and decreased collagen synthesis. Narrowband ultraviolet B (NB-UVB) radiation is a relatively new treatment modality for vitiligo and psoriasis. However, the mechanism of NB-UVB action on photoageing is not completely understood. Aims. We investigated the effects of NB-UVB on the expression of MMP-1, transforming growth factor (TGF)-beta1 and type I collagen in cultured human skin fibroblasts. METHODS: Cultured human fibroblasts were irradiated with either NB-UVB (50-800 mJ/cm(2)) or broadband UVB (BB-UVB; 25 mJ/cm(2)). The expression of MMP-1, TGF-beta1 and type I collagen mRNA was determined by reverse-transcription PCR. Expression of MMP-1 and TGF-beta1 protein was determined by ELISA and that of type I collagen by Western blotting. RESULTS: NB-UVB induced the expression of MMP-1 and reduced the expression of TGF-beta1 and type I collagen at the mRNA and protein levels in a dose-dependent manner. The expression of type I collagen protein decreased more after irradiation with 25 mJ/cm(2) of BB-UVB than 400 mJ/cm(2) of NB-UVB. CONCLUSIONS: This study indicates that NB-UVB irradiation reduces type I collagen synthesis in human skin fibroblasts by inhibiting TGF-beta1 expression and stimulating the release of MMP-1. It also suggested that the photoageing-related effects of NB-UVB are weaker than those of BB-UVB in vitro.

Cells, Cultured↗

PubMed2006

Skin problems after a tsunami.

BACKGROUND: On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated. OBJECTIVE: To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami. METHODS: Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh Province, Indonesia. RESULTS: The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. Contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected. CONCLUSIONS: Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.

Adult↗

PubMed1996

Genomic structure and chromosomal mapping of the mouse nov gene.

The nov gene encodes a cysteine-rich protein that is overexpressed in avian nephroblastomas. It is a member of the CCN family of proteins, all of which are involved in cell growth. Genomic and cDNA clones encompassing the mouse nov gene have been isolated and characterized. The mouse nov gene is highly conserved with the human and chick nov genes at the level of nucleotide sequence and genomic organization. The exon structure reflects the modular organization of the NOV protein in a number of structural domains. These are highly conserved with other members of the CCN family, as is the distribution of 38 of its 40 cysteine residues. The nov gene maps to chromosome 15, between D15 Mit 153 and D15 Mit 183, in a region of conserved synteny with human chromosome 8.

Amino Acid Sequence↗