Chi-Cheng Tsai

Antimicrobial activity of tannin components from Vaccinium vitis-idaea L.

Reactive oxygen species have been implicated as important pathological mediators in many clinical disorders, including periodontal disease. As a possible alternative for the treatment of periodontal disease, the antimicrobial activity of six tannins isolated from Vaccinium vitis‐idaea L., with confirmed antioxidant activity, were assayed by the agar dilution method against selected periodontal pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia. The results showed that epicatechin‐(4β → 8)‐epicatechin‐(4β → 8, 2β → O → 7)‐catechin had strong antimicrobial activity against P. gingivalis and P. intermedia, but not A. actinomycetemcomitans. The other tannins tested did not show antimicrobial activity. We conclude that tannins isolated from V. vitis‐idaea L. with antimicrobial activity could potentially be used for the treatment of periodontal disease.

Antioxidant activity of tannin components from Vaccinium vitis-idaea L.

Reactive oxygen molecules have been implicated as important pathological mediators in many clinical disorders and periodontal disease. To provide possible alternative treatment of periodontal disease, six tannins isolated from Vaccinium vitis‐idaea L. were evaluated for anti‐lipid peroxidation, anti‐superoxide formation and free radical scavenging activity.

Polymorphisms of COX-2 -765G > C and p53 codon 72 and risks of oral squamous cell carcinoma in a Taiwan population

The association between polymorphisms of COX-2 -765G>C and p53 codon 72, and oral squamous cell carcinoma (OSCC) remains unclear. We investigated the associations between COX-2 and p53 polymorphisms, oral precancerous lesions (OPL), and OSCC. Demographic data and substance use (smoking, drinking, and betel quid chewing) data were collected from 297 patients with OSCC, 70 with oral leukoplakia (OL), 39 with oral submucosal fibrosis (OSF), and 280 healthy controls. COX-2 and p53 polymorphisms were determined by PCR-RFLP methods. A significantly higher proportion of OSCC and OPL patients were male, and frequent habitual users of the three substances. No association was found between p53 and COX-2 polymorphisms, ethnicity, and gender. Polymorphisms of p53 were not associated with OSCC development and malignant potential of OPL, OSF, and OL. The frequency of COX-2 -765G/G genotype was significantly higher in healthy controls (chi(2)=93.83, p<0.0001). After adjusting for possible confounding factors, COX-2 -765C allele vs. -765G/G genotype (OR=0.22, 95%CI=0.12-0.39) was a protective factor against OSCC development, but was a risk factor for malignant potential of OSF (OR=3.20, 95%CI=1.32-8.94) and OL (OR=6.73, 95%CI=2.84-19.87). We suggest that COX-2 -765G>C polymorphisms play a different role in OSCC development than in malignant potential of OSF and OL. However, p53 codon 72 polymorphisms show no such correlation.

Changes in Gingival Crevicular Fluid Interleukin-4 and Interferon-gamma in Patients with Chronic Periodontitis Before and After Periodontal Initial Therapy

Cytokines are pivotal to the immune response of chronic periodontitis. The present study investigated the changes of gingival crevicular fluid (GCF) interleukin‐4 (IL‐4) and interferon‐gamma (IFN‐γ) in patients with chronic periodontitis before and after initial nonsurgical periodontal therapy (NSPT). GCF was collected from 17 patients by means of Periopaper® at baseline and 1 month after NSPT. IL‐4 and IFN‐γ were measured by enzyme‐linked immunoabsorbent assay. NSPT resulted in decreased total amount of IFN‐γ, increased concentration of IL‐4, and increased ratio of IL‐4 to IFN‐γ levels. We suggest that a low ratio of IL‐4 to IFN‐γ levels might be involved in the destruction (diseased sites) of periodontal tissue, whereas an increased ratio of IL‐4 to IFN‐γ levels could be related to the improvement of clinical periodontal health.

Cyclooxygenase-2 Gene-765 single nucleotide polymorphism as a protective factor against periodontitis in Taiwanese.

AIM Prostaglandin E(2) (PGE(2)) is considered to be an important mediator of tissue destruction in periodontitis. The cyclooxygenase (COX) catalyses the production of PGs. COX-2, which is induced in an inflammatory response, is responsible for PGs synthesis at sites of inflammation. A single nucleotide polymorphism of COX-2(-765) has been shown to alter the expression of the COX-2 gene. The purpose of the present study was to evaluate the association of the COX-2(-765) polymorphism and susceptibility to periodontitis in Taiwanese. MATERIAL AND METHODS Eighty-five cases of aggressive periodontitis (AgP), 343 cases of chronic periodontitis (CP) and 153 cases of healthy controls (HC) were recruited for the study. Genotypes of COX-2(-765) were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The distribution of genotypes among groups was compared by logistic regression analyses. The risk for periodontitis associated with genotypes was calculated as the odds ratio (OR). RESULTS The prevalence of the GC and CC genotypes was significantly lower in AgP (5%) and in CP (29%) compared with the HC (42%). The ORs for carriage of the -765C allele (GC+CC versus GG) in AgP and CP were 0.068 (95% CI=0.020-0.173, p<0.0001) and 0.571 (95% CI=0.385-0.849, p=0.006), respectively. After adjustment for age, gender and smoking status, the OR was 0.071 (95% CI=0.017-0.219) and 0.552 (95% CI=0.367-0.829) for AgP and CP, respectively. CONCLUSIONS The results of the study suggest that the -765G to C polymorphism of the COX-2 gene is associated with a decreased risk for periodontitis in Taiwanese, especially in AgP. However, the biological meaning needs further investigation.

Prognostic factors associated with the survival of oral and pharyngeal carcinoma in Taiwan

BackgroundIn Taiwan, a distinct ethnic group variation in incidence and mortality rates has been suggested for most carcinomas. Our aim is to identify the role of prognostic factors associated with the survival of oral and pharyngeal carcinoma in Taiwan.MethodsTaiwan Cancer Registry records of 9039 subjects diagnosed with oral and pharyngeal carcinoma were analyzed. The population was divided into three ethnic groups by residence, which were Taiwanese aborigines, Hakka and Hokkien communities. Five-year survival rates were estimated by Kaplan-Meier methods. Ethnic curves differed significantly by log-rank test; therefore separate models for Taiwanese aborigines, Hakka and Hokkien were carried out. The Cox multivariate proportional hazards model was used to examine the role of prognostic factors on ethnic survival.ResultsThe five-year survival rates of oral and pharyngeal carcinoma were significantly poorer for Hokkien community (53.9%) and Taiwanese aborigines community (58.1%) compared with Hakka community (60.5%). The adjusted hazard ratio of Taiwanese aborigines versus Hakka was 1.07 (95%CI, 0.86–1.33) for oral and pharyngeal carcinoma mortality, and 1.16 (95%CI, 1.01–1.33) for Hokkien versus Hakka. Males had significantly poor prognosis than females. Subjects with tongue and/or mouth carcinoma presented the worst prognosis, whereas lip carcinoma had the best prognosis. Subjects with verrucous carcinoma had better survival than squamous cell carcinoma. Prognosis was the worst in elderly subjects, and subjects who underwent surgery had the highest survival rate.ConclusionOur study presented that predictive variables in oral and pharyngeal carcinoma survival have been: ethnic groups, period of diagnosis, gender, diagnostic age, anatomic site, morphologic type, and therapy.

Polymorphisms in the apoptosis-associated genes FAS and FASL and risk of oral cancer and malignant potential of oral premalignant lesions in a Taiwanese population.

BACKGROUND Our aim was to measure the relationship of FAS (-1377G>A and -670A>G), FASL (-844C>T) gene variants and risk of oral cancer. METHODS Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to determine the FAS and FASL polymorphisms in 294 oral squamous cell carcinoma (OSCC), 53 oral submucous fibrosis (OSF), and 84 oral leukoplakia (OL) patients, as well as in 333 healthy controls. A standardized questionnaire was applied to collect demographic data, and potential confounding factors. JMP statistical software was used to analyze the association. RESULTS FAS and FASL polymorphisms were not correlated with OSCC development or the malignant potential of OL by simple and multivariate logistic regression. However, a two- to fourfold difference in the risks of betel quid chewing, alcohol consumption, and smoking on OSCC development were observed between participants with different FAS polymorphisms. FAS polymorphisms were significantly correlated with the malignant potential of OSF. Multivariate logistic regression analysis indicated that FAS A(-1377)-G(-670) vs. G(-1377)-A(-670) haplotype (OR = 2.26, 95% CI = 1.16-4.41) was correlated with the malignant potential of OSF. CONCLUSIONS We suggest that FAS and FASL polymorphisms are not significantly correlated with OSCC development or malignant potential of OL. The impact of substance usage on OSCC development could be differentiated by FAS polymorphisms. FAS A(-1377)-G(-670) haplotype may play a role in the malignant potential of OSF.

Potential Role of Vascular Endothelial Growth Factor, Interleukin-8 and Monocyte Chemoattractant Protein-1 in Periodontal Diseases

Host‐mediated immunoinflammatory pathways activated by bacteria lead to destruction of the periodontal connective tissues and alveolar bone. The objective of this study was to elucidate the activation of the inflammatory processes in periodontal disease by quantitative assessment of cytokines and periodontopathogens. Gingival crevicular fluids (GCF) and subgingival plaque samples were collected from patients with chronic periodontitis and gingivitis and from periodontally healthy sites. Vascular endothelial growth factor (VEGF), monocyte chemoattractant protein‐1 (MCP‐1), and interleukin 8 (IL‐8) in GCF were analyzed by enzyme‐linked immunosorbent assay. Periodontopathogens, including Bacteroides forsythus, Campylobacter rectus, Porphyromonas gingivalis and Prevotella intermedia, were analyzed by immunofluorescence and dark‐field microscopy. There was significantly more VEGF and IL‐8 in chronic periodontitis and gingivitis sites than in periodontally healthy sites. There were significant positive correlations between the concentrations and total amounts of VEGF and IL‐8 in chronic periodontitis and gingivitis sites, and between the levels of periodontopathogens and the total amounts of VEGF, MCP‐1 and IL‐8. These data indicate that inflammatory processes induced by periodontopathogens and the activation of certain cytokines (VEGF, MCP‐1, IL‐8) in periodontal diseases may be relevant to host‐mediated destruction in chronic periodontitis.

Interleukin-1 ß in Oral Submucous Fibrosis, Verrucous Hyperplasia and Squamous Cell Carcinoma Tissues

Interleukin-1 beta (IL-1 beta) has been proven to be a multi-effect mediator of inflammation including in the promotion of inflammatory cells to move from blood to inflamed tissues, the regulation of the synthesis and decomposition of extra-cellular matrix, and indirectly in causing bone resorption and inhibition of bone growth. In this study, the amounts of IL-1 beta in the biopsied specimens of normal oral mucosa, oral submucous fibrosis (OSF), oral squamous cell carcinoma (OSCC), and verrucous hyperplasia (VerH) were quantified by ELISA. The results showed that the amounts of IL-1 beta (pg per mg tissue, mean +/- SD) in normal oral mucosa, OSF, OSCC, and VerH were 1.07 +/- 0.53, 0.76 +/- 0.56, 4.37 +/- 0.87 and 3.97 +/- 1.93 respectively. There were no significant differences (p > 0.05, Mann-Whitney U Test) between the amounts of IL-1 beta in normal oral mucosa and OSF, and between VerH and OSCC. However, a significant difference in IL-1 beta level was found (p < 0.001) between normal oral mucosa and OSCC or VerH. Immunohistochemistry staining technique using antibody against IL-1 beta showed positive staining in hyperplastic epithelium (VerH) and tumor cells of OSCC. These results might suggest a correlation between the amounts of IL-1 beta in oral precancerous and cancerous lesions and cell transformation. On the other hand, the amount of IL-1 beta did not change significantly as OSF progressed. Thus, IL-1 beta levels may not be useful to gauge the seriousness of fibrosis, but the gradual increase in IL-1 beta level from normal oral mucosa through VerH to OSCC suggests that IL-1 beta may play an important role in oral carcinogenesis.

Risk Factors for Edentulism among the Elderly of Taiwan

Object: The purpose of this study is to explore the possible causes of edentulism among Taiwanese over 65 years elders. Methods: A sample of 1,600 elders was randomly selected. Measurement parameters used in this research were structured questionnaires composed by the researchers. Information gathering was done by trained individuals who visited the subjects at their homes. A logistic regression analysis was performed to determine the factors that cause the elders to become completely toothless. Results: The risk factors of edentulism are as follows: individuals who are older age i.e., aging, female, having lower education level, having lower frequency of weekly social activities, having lower frequency of tooth brushing, having the habit of chewing betel nuts, or having hypertension and diabetes, not having regular dental checked, not visiting a fixed dental clinic for service, not using the dental floss. Conclusions: In the future, the government shall exert great efforts to establish the family-dentist system for better dental health care and protection, to publicize the correct knowledge of dental hygiene, to instruct the correct guidance of keeping good oral health condition; and also, to regularly follow up the oral screen and dental check on particular population with chronic disease in order to provide the therapy as needed.