J-J Lee

National Taiwan University Hospital, T’ai-pei, Taipei, Taiwan

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Publications (4)11.96 Total impact

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    ABSTRACT: OBJECTIVE: Placenta growth factor (PlGF) is associated with the progression and prognosis of oral cancer. MATERIALS AND METHODS: This study used ELISA, quantitative polymerase chain reaction, and Western blotting to study the arecoline-stimulated (PlGF) protein or mRNA expression in human gingival epithelial S-G cells. RESULTS: Arecoline, a major areca nut alkaloid and an oral carcinogen, could stimulate PlGF protein synthesis in S-G cells in a dose- and time-dependent manner. The levels of PlGF protein secretion increased about 3.1- and 3.8-fold after 24-h exposure to 0.4 and 0.8 mM arecoline, respectively. Pretreatment with antioxidant N-acetyl-l-cysteine (NAC) and ERK inhibitor PD98059, but not NF-κB inhibitor Bay 11-7082, JNK inhibitor SP600125, p38 MAPK inhibitor SB203580, and PI3-K inhibitor LY294002, significantly reduced arecoline-induced PlGF protein synthesis. ELISA analyses demonstrated that NAC and PD98059 reduced about 43% and 38% of the arecoline-induced PlGF protein secretion, respectively. However, combined treatment with NAC and PD98059 did not show additive effect. Moreover, 10 μM curcumin and 4 mM NAC significantly inhibited arecoline-induced ERK activation. Furthermore, 10 μM curcumin completely blocked arecoline-induced PlGF mRNA expression. CONCLUSION: Arecoline-induced PlGF synthesis is probably mediated by reactive oxygen species/ERK pathways, and curcumin may be an useful agent in controlling oral carcinogenesis.
    Oral Diseases 10/2012; · 2.38 Impact Factor
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    ABSTRACT: Biocompatibility of dentin bonding agents (DBA) and composite resin may affect the treatment outcome (e.g., healthy pulp, pulpal inflammation, pulp necrosis) after operative restoration. Bisphenol-glycidyl methacrylate (BisGMA) is one of the major monomers present in DBA and resin. Prior studies focused on salivary esterase for metabolism and degradation of resin monomers clinically. This study found that human dental pulp cells expressed mainly carboxylesterase-2 (CES2) and smaller amounts of CES1A1 and CES3 isoforms. Exposure to BisGMA stimulated CES isoforms expression of pulp cells, and this event was inhibited by catalase. Exogenous addition of porcine esterase prevented BisGMA- and DBA-induced cytotoxicity. Interestingly, inhibition of CES by bis(p-nitrophenyl) phosphate (BNPP) and CES2 by loperamide enhanced the cytotoxicity of BisGMA and DBA. Addition of porcine esterase or N-acetyl-l-cysteine prevented BisGMA-induced prostaglandin E(2) (PGE(2)) and PGF(2α) production. In contrast, addition of BNPP and loperamide, but not mevastatin, enhanced BisGMA-induced PGE(2) and PGF(2α) production in dental pulp cells. These results suggest that BisGMA may induce the cytotoxicity and prostanoid production of pulp cells, leading to pulpal inflammation or necrosis via reactive oxygen species production. Expression of CES, especially CES2, in dental pulp cells can be an adaptive response to protect dental pulp against BisGMA-induced cytotoxicity and prostanoid release. Resin monomers are the main toxic components in DBA, and the ester group is crucial for monomer toxicity.
    Acta biomaterialia 09/2011; 8(3):1380-7. · 5.68 Impact Factor
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    ABSTRACT: To investigate the incidence and risk factors of post-tooth extraction sepsis in patients without locoregional infection. We assessed all claim records of the Taiwanese National Health Insurance program in 2005. Admissions for patients aged > or =16 years containing a discharge diagnosis of sepsis, and who received tooth extraction within 14 days before the admission were identified. Patient charts were reviewed to confirm the diagnosis of sepsis and rule out other infection sources. The relationship between postextraction sepsis (PES) and clinical parameters was analyzed. Thirty-three of the 2 223 971 extraction cases met the criteria of PES, an incidence of 1.48 per 100 000, and seven patients (21.2%) died of the disease. Aging significantly increased the risk of PES (P < 0.001). Pre-existing comorbidities were found in 20 of the 33 cases, with diabetes mellitus and hematologic diseases the most common. The method, number, and position of extraction had no influence on PES incidence. Blood cultures were positive in 25 patients (75.8%) and isolates included species of the Streptococcus, Actinomyces, Klebsiella, Bacteroides, Prevotella, and Enterococcus genera. Tooth extraction is associated with a low but significant risk of postoperative sepsis, especially in the elderly and patients with underlying diseases.
    Oral Diseases 08/2009; 15(8):602-7. · 2.38 Impact Factor
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    ABSTRACT: The purpose of this study was to compare the periodontal healing of mandibular second molars after the removal of impacted mandibular third molars using distolingual alveolectomy and tooth division techniques. A total of 120 consecutive healthy patients who presented with bilaterally impacted mandibular third molars were included in this study. The same operator removed the impacted third molars on both sides in all patients. The third molar on one side was removed by distolingual alveolectomy using a chisel, whereas the contralateral tooth was removed by the tooth division technique using burs. Attachment level, periodontal pocket depth and bone healing distal to the mandibular second molars were assessed at 7 days, 3 months and 6 months after surgery. The results showed better periodontal healing and bone healing when distolingual alveolectomy was employed, especially in the removal of deeply impacted mandibular third molars.
    International Journal of Oral and Maxillofacial Surgery 02/2004; 33(1):32-7. · 1.52 Impact Factor