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Flexible endoscopy can enhance detailed inspection of oral cavity mucosa and can be a powerful tool for examining oral leukoplakia. The IPCL patterns shown by NBI system can be helpful in detecting oral leukoplakia with higher grade dysplasia or invasive carcinoma.

The NBI images of twisted elongation of IPCL and IPCL pattern destruction are indicators of high-grade dysplasia or carcinomatous lesions in oral leukoplakia.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), originally identified as the major receptor for oxidized low-density lipoprotein (oxLDL) in endothelial cells, plays a major role in the pathology of vascular diseases. Green tea consumption is associated with reduced cardiovascular mortality in some epidemiological studies. In the present study, we hypothesized that the most abundant polyphenolic compound in tea, epigallocatechin-3-gallate (EGCG), can downregulate parameters of endothelial dysfunction by modulating LOX-1-regulated cell signaling. In cultured human umbilical vein endothelial cells (HUVECs), exposure to oxLDL (130 microg/ml), which led to an increase in LOX-1 expression at the RNA and protein levels, was abrogated by addition of EGCG or DPI, a well-known inhibitor of flavoproteins, suggesting the involvement of NADPH oxidase. Furthermore, oxLDL rapidly activated the membrane translocation of Rac-1 and p47phox and the subsequent induction of ROS generation, which was suppressed markedly by pretreatment with EGCG or anti-LOX-1 monoclonal antibody. OxLDL also increased p38 MAPK phosphorylation and decreased phosphorylation of the amino-terminal region of Akt, with maximal induction at about 30 min, and NF-kappaB phosphorylation within 1 h, resulting in redox-sensitive signaling. In addition, oxLDL diminished the expression of endothelial nitric oxide synthase (eNOS), enhanced the expression of endothelin-1 and adhesion molecules (ICAM, E-selectin, and monocyte chemoattractant protein-1), and increased the adherence of monocytic THP-1 cells to HUVECs. Pretreatment with EGCG, however, exerted significant cytoprotective effects in all events. These data suggest that EGCG inhibits the oxLDL-induced LOX-1-mediated signaling pathway, at least in part, by inhibiting NADPH oxidase and consequent ROS-enhanced LOX-1 expression, which contributes to further ROS generation and the subsequent activation of NF-kappaB via the p38 MAPK pathway. Results from this study may provide insight into a possible molecular mechanism by which EGCG suppresses oxLDL-mediated vascular endothelial dysfunction.

The aim of this study is to evaluate the treatment outcome and analyze the associated factors of postoperative recurrence in patients who received transoral laser microsurgery for vocal cord leukoplakia. The demographic, histopathological data were retrospectively reviewed and the factors associated with recurrence of vocal leukoplakia after surgery were analyzed statistically. A total of 44 patients, including 36 males and 8 females, with a mean age of 50.4 ± 13.4 years, were enrolled. All the patients received excision of the vocal leukoplakia by carbon dioxide laser (2-4 Watt, ultrapulse mode) under general anesthesia. No patients had malignant transformation after surgery. Postoperative recurrence occurred in 10 patients (22.7 %). Univariate analysis showed that patients who had the habit of cigarette smoking, alcohol drinking, and presence of gastroesophageal reflux disease tended to recur. Among these risk factors, presence of gastroesophageal reflux disease (odds ratio 8.43) was the independent prognostic factor for recurrence using multivariate logistic regression analysis. Carbon dioxide laser excision is effective for treating vocal leukoplakia that is still confined to dysplasia of any degree, with acceptable morbidity. This study suggests that the presence of gastroesophageal reflux disease is the prognostic indicator for postoperative recurrence of vocal leukoplakia. Aggressive treatment of reflux disease for those who have received surgical excision for vocal leukoplakia is indicated.

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<i>Purpose:</i> To evaluate the clinical usefulness of endoscopy with a narrow-band imaging (NBI) system for the evaluation and management of homogeneous oral leukoplakia. <i>Methods:</i> The chart records, morphology of vascular architecture of NBI, and histopathology of patients with homogeneous leukoplakia were retrospectively reviewed and analyzed. <i>Results:</i> A total of 160 patients, with an average age of 50.96 ± 10.25 years, were enrolled. In 35 cases of thin leukoplakia, only intraepithelium papillary capillary loop (IPCL) type I was shown by NBI, and only squamous hyperplasia was revealed pathologically. In 125 cases of thick leukoplakia, IPCL type I was found in 94, IPCL type II in 29, and IPCL type III in 2. The Kendall rank correlation between pathology and NBI images was significant (p < 0.0001). <i>Conclusions:</i> The dichotomous classification of homogeneous leukoplakia by NBI is meaningful, and endoscopy with the NBI system is a promising tool for the evaluation and management of homogeneous oral leukoplakia.