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Background: Our previous studies showed that topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) is very effective for oral verrucous hyperplasia (OVH) and relatively less effective for oral leukoplakia (OL) lesions. Nevertheless, there has been no report on the association of the expression of apoptosis-related proteins in OVH and OL biopsy tissues prior to PDT with PDT treatment outcomes., Methods: This study used immunohistochemistry to evaluate whether the expression of Bak, Mcl-1, caspase-3, caspase-8, caspase-9, p53, p21, or PCNA protein in biopsy specimens of OVH and OL lesions could be used to predict the clinical outcomes of 18 OVH and 40 OL lesions treated with topical ALA-PDT. The marker labeling score (LS) was defined as labeling index (positive cells/total cells) multiplied by staining intensity. The lesions after ALA-PDT treatment were divided into complete response (CR) group and partial or no response (PR/NR) group., Results: The mean Bak LS and the mean Bak/Mcl-1 LS ratio were significantly higher in the CR group than in the PR/NR group. However, there was no significant difference in the Mcl-1, caspase-3, caspase-8, caspase-9, p53, p21, or PCNA protein LS between the CR and PR/NR groups., Conclusion: We conclude that the Bak LS or Bak/Mcl-1 LS ratio may be a useful biomarker to predict the clinical outcomes of OVH and OL lesions treated with topical ALA-PDT. Pre-PDT epithelial cell levels of Mcl-1, caspase-3, caspase-8, caspase-9, p53, p21, and PCNA may not have a significant influence on the clinical outcome of OVH and OL lesions treated with topical ALA-PDT., (© 2012 John Wiley & Sons A/S. All rights reserved.)

Data from epidemiological studies have indicated that diets rich in fruits and vegetables are likely to benefit many aspects of the prevention of oral malignancy. Lycopene is a red-coloured carotenoid predominantly accumulated in tomatoes as well as other fruits and vegetables. It has been claimed to alleviate chronic diseases such as cancers and cardiovascular disease. Hence, the aim of this review is to summarize the features and its potential significance of lycopene in the development, prevention and treatment of oral premalignant lesions and oral cancer. Studies showed that lycopene might have beneficial effects in the management of some premalignant lesions in the oral cavity including oral submucous fibrosis and oral leukoplakia and may be an adjunct in the prevention and therapy of oral cancer. However, more mechanistic studies and randomized controlled trials of large sample size are necessary to further confirm these effects and to eventually make lycopene to be used in the community prevention and clinically routine management of these diseases., (© 2010 John Wiley & Sons A/S.)

Background: Oral verrucous hyperplasia (OVH) and oral erythroleukoplakia (OEL) are two oral precancerous lesions with relatively high malignant transformation potential. One of the best cancer prevention strategies is to use a conservative and effective treatment modality to eliminate oral precancers to stop their further malignant transformation. Our previous studies have shown that the topical 5-aminolevulinic acid-mediated photodynamic therapy (topical ALA-PDT) using the 635-nm light-emitting diode (LED) light is very effective for OVH and OEL lesions., Methods: Because the laser machine is a more-popular light source than the LED device in PDT clinics, in this study 40 OVH and 40 OEL lesions were treated once a week with the same PDT protocol but using the 635-nm laser light to evaluate whether this laser light-mediated topical ALA-PDT was also effective for OVH and OEL lesions., Results: We found that all the 40 OVH lesions exhibited complete response (CR) after an average of 3.6 PDT treatments. Of the 40 OEL lesions, 38 showed CR after an average of 3.4 PDT treatments and two showed partial response (PR). Better PDT outcomes were significantly associated with OVH and OEL lesions with the smaller size, pink to red color, epithelial dysplasia, or thinner surface keratin layer., Conclusion: This study indicates that the laser light-mediated topical ALA-PDT is also very effective for OVH and OEL lesions. Therefore, we suggest that topical ALA-PDT using either the LED or laser light may serve as the first-line treatment of choice for OVH and OEL lesions., (© 2010 John Wiley & Sons A/S.)

Objective: To examine the effects of polaprezinc on morphologic change of the tongue epithelium and on cell cycle regulation of taste bud cells by using zinc-deficient rats, an animal model of taste disturbance., Methods: After 28 days of feeding with zinc-sufficient or -deficient diet, the rats fed a zinc-deficient diet were divided into four groups in which 0, 1, 3 and 10 mg/kg of polaprezinc were administered for 28 days with continuation of diet. Histopathological and morphological examinations of the tongue were carried out., Results: Parakeratosis was observed in all rats receiving the zinc-deficient diet and 1 mg/kg polaprezinc but not in rats receiving 3 and 10 mg/kg polaprezinc. The ratio of keratinizing epithelium in the outer and inner circumference were significantly increased from 9.6% and 11.3%, respectively, in zinc-sufficient rats to 36.9% and 32.9%, respectively, in zinc-deficient rats (P<0.001 and <0.01). This increase was reversed to 13.7% and 12.3% in rats that received 3 and 10 mg/kg polaprezinc in the outer circumference, respectively. Same phenomenon was seen in the inner circumference part, 13.0% and 10.8% (P<0.01), respectively. In addition, proliferating cell nuclear antigen-positive cells in the taste bud were significantly decreased from 75.5% in zinc-sufficient rats to 32.2% in zinc-deficient rats (P<0.001). This decrease was reversed to 70.3%, 83.1% and 81.2% in rats that received 1, 3 and 10 mg/kg polaprezinc, respectively., Conclusion: Polaprezinc improves parakeratosis and decreases taste bud cell proliferation caused by zinc deficiency. These effects may be involved in mechanisms underlying improvement of taste disorders in animal models., (© 2010 Zeria Pharmaceutical Co., Ltd. Journal of Oral Pathology & Medicine © 2010 John Wiley & Sons A/S.)

Background: Photodynamic therapy (PDT) is a non-invasive method for topical and selective treatment of pre-malignant lesions of oral cavity. The aim of our study was to determine therapeutic response to PDT in patients with oral leukoplakia., Methods: Twelve patients participated in our study. Lesions affected a variety of intraoral sites. The most common location was buccal, gingival and mandibular mucosa. Patients were treated with topically applied 10% delta-aminolevulinic acid (ALA) and light from an argon-pumped dye laser. Irradiation was performed in several (6-8) sessions using light at 635 nm wavelength, delivering a total dose of 100 J/cm2 per session., Results: A complete response was obtained in 10 out of 12 treated patients. One recurrence was observed during 6 months., Conclusion: Photodynamic therapy appears to be a feasible alternative to conventional therapy of pre-malignant lesions of oral cavity.