Biomedical subjects

Jun Yeon Won

Publications and source records attributed to Jun Yeon Won.

3 recordsLinked to original sources

PubMed2004

The effect of cellular retinoic acid binding protein-I expression on the CYP26-mediated catabolism of all-trans retinoic acid and cell proliferation in head and neck squamous cell carcinoma.

The aim of this study was to confirm if catabolism of all-trans retinoic acid (RA) is enhanced by type I cellular retinoic acid binding protein (CRABP-I) expression and to investigate the effect of this enhanced catabolism on cell proliferation of the head and neck squamous cell carcinoma (HNSCC) cell line, AMC-HN-7. We also analyzed the effects of CRABP-I on RA-induced retinoic acid receptor (RAR) activity. The expression of the CRABP-I in stably transfected AMC-HN-7 cell lines (HN7-BPIa and HN7-BPIb) resulted in a lower sensitivity to administered RA compared with that of controls in a clonogenic assay. HN7-BPIs cells showed an increased amount of polar metabolites of RA in thin-layer chromatography. The transcriptional activity of the reporter plasmid RARE(DR5)-tk-CAT after the treatment of RA was lesser in HN7-BPIs than in controls. These results suggest that the increased CYP26-mediated catabolism of RA by CRABP-I transfection might decrease the amount of RA that is accessible to the nuclear receptors and make HNSCC cells resistant to RA.

Blotting, Western↗

PubMed2004

Extratympanic electrocochleographic changes on noise-induced temporary threshold shift.

OBJECTIVE: Electrocochleography (ECoG) is a sensitive evoked-response test for evaluating changes in cochlear function. We investigated the extratympanic ECoG in a noise-induced temporary threshold shift (TTS) to evaluate the usefulness of ECoG in the early detection of noise-induced hearing loss (NIHL). STUDY DESIGN AND METHODS: In a prospective analysis, 15 healthy ears were exposed to 90.3- to 105.0-dB noise for 3 hours in the same computer-game arcade. Pure-tone audiometry and ECoG were performed before, immediately after, and 24 hours after the exposure. RESULTS: Before the exposure, the average hearing level was 5.8 +/- 2.7 dB, which increased significantly to 12.8 +/- 2.8 dB immediately after exposure. A marked increment in the SP/AP (summating potential/action potential) ratio was observed with the TTS. The mean ratio was 0.22 +/- 0.11 before the exposure, 0.46 +/- 0.18 in the TTS phase, and 0.20 +/- 0.11 after resolution. CONCLUSION: The results of this study suggest that the SP/AP ratio is useful for the early detection and monitoring of NIHL.

Action Potentials↗

PubMedDate not supplied

Inflammatory pseudotumor in the epidural space of the thoracic spine: a case report and literature review of MR imaging findings.

We present a rare case of pathologically proven inflammatory pseudotumor in the thoracic spine. The lesion showed an isointense signal on T1-weighted images, a heterogeneous iso- and hyperintense signal on T2-weighted images, and strong homogeneous enhancement. There was no evidence of abnormalities in the adjacent bone. Whereas the exact pathogenesis of this lesion is unknown, it has been regarded as an unusual response to insults such as trauma or acute infection, a post-inflammatory reparative process, or low-grade malignancy.

Adult↗