Analysis of Epstein-Barr Virus Infection in Oral Potentially Malignant Disorders and Oral Cancer: A Cross-Sectional Study.

Aims and Objectives: The primary objective of this study is to determine the prevalence of Epstein-Barr virus (EBV) in oral potentially malignant disorders (OPMDs) and oral cancer (OC) in a group of Thais using polymerase chain reaction (PCR) and Epstein-Barr encoding regions (EBERs) in situ hybridization (ISH). The secondary objective is to investigate the risk factors of OC and the association between the presence of EBV and risk factors of OC/site of oral lesions. Materials and Methods: Sixty-one participants attending the screening project for OC and OPMDs at the Northeastern district hospitals of Thailand were recruited. Information related to risk factors and biopsy tissues for histopathological diagnosis was collected. Sixty-seven paraffin tissue blocks, including 52 OPMDs and 15 OC specimens, were investigated for EBV infection, using PCR analysis with latent membrane protein-1 (LMP-1) primer and EBERs ISH. Pearson's Chi-square or Fisher's exact test was used to analyze the differences in variables between participants with OPMDs and OC, as appropriate. The association between EBV infection and related risk factors was analyzed using logistic regression with a significant level at 0.05. Results: Using PCR analysis, 8 of 67 specimens (11.94%) were positive for LMP-1. Three cases of OPMDs were positive for both LMP-1 PCR and EBERs ISH. Regarding risk factors of OC, the two most common risk factors were betel nut chewing (52.46%) and working in sunlight (42.62%). The habit of taking alcohol was significantly different between the OC and the OPMDs groups (p = 0.009). The association between LMP-1 and the lesion at the tongue was statistically significant, with odds ratio = 4.900 (95% confidence interval = 1.046-22.943; p = 0.044). Conclusions: The prevalence of EBV infection in this group of participants was low. However, OPMDs at the tongue exhibited a significant association with EBV infection.

Presence of Candida and its associated factors in participants attending oral cancer screening in the lower northeastern area of Thailand.

BACKGROUND: Certain evidence indicated high prevalence of Candida in oral potentially malignant disorders (OPMDs) and oral cancer (OC). This study was aimed to investigate the presence of Candida and its associated factors in participants who attended the oral cancer screening program in the lower northeastern districts of Thailand. METHODS: Convenient participants residing in the lower northeastern districts of Thailand who attended the oral cancer screening were enrolled. A questionnaire retrieving demographic characteristics, risk factors of oral cancer, and risk of having Candida was completed. Oral examination was performed by oral medicine specialists or oral surgeons. The participants were categorized into 4 groups according to their clinical diagnosis, namely normal oral mucosa (NOM), OPMDs/OC, non-OPMDs/OC and clinically suspected oral candidiasis (CSOC). Stimulated saliva flow rate was measured. Dip-slide test was performed in each participant to evaluate the presence of Candida. The levels of Candida were categorized into high and low levels according to the score received from the dip-slide test. Factors associated with high levels of Candida were identified using multivariate logistic regression analysis. RESULTS: A total of 577 participants were recruited. High levels of Candida were found in 31.3%, 24.7%, 25.9% and 18.1% in the OPMDs/OC, the non-OPMDs/OC, the CSOC and the NOM groups, respectively. According to multivariate logistic regression analysis, age above 60 years, female gender, betel quid chewing habit, use of denture, hyposalivation, and being in the CSOC group were found to be significantly associated with high levels of Candida. CONCLUSION: Higher number of participants in the OPMDs/OC group was found to have high levels of Candida. Increasing age, female gender, betel quid chewing habit, use of denture, hyposalivation and having CSOC lesions were associated with high levels of Candida.

Epstein-Barr Virus Detection and LMP-1 Expression in Thai Patients with Oral Squamous Cell Carcinoma.

BACKGROUND: To date, high-risk human papillomavirus (HPV) is primarily linked to oropharyngeal carcinoma, but only a small subset of oral squamous cell carcinoma (OSCC) is truly driven by high-risk HPV. In addition, Epstein-Barr virus (EBV) is another potential oncogenic virus for OSCC development. This study aims to investigate the role of EBV infection in Thai patients with OSCC. METHODS: Forty-seven formalin-fixed paraffin-embedded specimens of OSCC were obtained. EBV DNA was detected by polymerase chain reaction analysis using primers for LMP-1 region of EBV. EBV-positive OSCC cases were subjected to LMP-1 immunohistochemical analysis and EBV-encoded small RNA (EBER) in situ hybridization to determine EBV cellular localization in OSCC. LMP-1 immunohistochemical analysis was also performed in all EBV-negative OSCC cases. RESULTS: Of the 47 OSCC specimens, ten (21%) exhibited EBV DNA by PCR analysis. Seven of ten (70%) EBV-positive specimens showed high-grade LMP-1 expression by immunohistochemistry. However, no EBER expression was detected in all EBV-positive OSCC specimens. In EBV-negative specimens, LMP-1 was also negative except in 3 specimens which showed low grade expression of LMP-1. CONCLUSION: The prevalence of EBV infection in OSCC in this group of Thai patients was 21%. Most of EBV-positive OSCC cases showed LMP-1 expression but a lack of EBER expression. From our findings, we presume that EBV may take some roles in OSCC development in this group of participants.

Histopathological and risk factor analyses of oral potentially malignant disorders and oral cancer in a proactive screening in northeastern Thailand.

BACKGROUND: Lip and oral cavity cancer has been reported as the 10th most common cancer in Thailand. Recently, a screening program for oral potentially malignant disorders (OPMDs) and oral cancer was conducted in the northeastern Thailand which took into consideration a total of 371,911 people who resided in the provinces of Buriram, Chaiyaphum, Nakhon Ratchasima, and Surin. METHODS: A total of 330,914 subjects were consecutively screened for risk factors of oral cancer by village health volunteers (VHVs) using a questionnaire (S1). Then, 186,710 subjects with one or more risk factors for oral cancer were referred for oral screening by dental auxiliaries or dentists at sub-district level hospitals (S2) where 86,941 subjects were subsequently screened. Afterwards, 1576 subjects with suspicious oral lesions for OPMDs or oral cancer attended local hospitals for further investigation and treatment. Oral medicine specialists, oral surgeons, and local dentists at the district level hospitals performed biopsies and the samples were sent for histopathological analysis. The objectives of the study were to report the histopathology findings from the biopsies obtained from these subjects and the associated risk factors. RESULTS: Out of 427 subjects who received biopsies, complete diagnostic results were obtained from 409 patients (462 specimens). The 5 most common histopathological results from these specimens were mild epithelial dysplasia (27.3%), fibroepithelial hyperplasia (14.5%), oral lichen planus/oral lichenoid reactions (11.5%), moderate epithelial dysplasia (8%), and acanthosis with or without hyperkeratosis (5%). Oral squamous cell carcinoma was detected in 14 subjects and 11 other forms of oral cancer were revealed. Among the analyzed risk factors, habitual betel quid chewing was established as a statistically significant risk factor associated with OPMDs and oral cancer. CONCLUSION: The most frequently observed histopathological results of clinically suspected oral cancer and OPMDs included mild epithelial dysplasia, fibroepithelial hyperplasia, oral lichen planus/oral lichenoid reactions, moderate epithelial dysplasia, and acanthosis with or without hyperkeratosis. Betel quid chewing habit was found to be associated with OPMDs and oral cancer.

Production and antimicrobial activity of trans-resveratrol, trans-arachidin-1 and trans-arachidin-3 from elicited peanut hairy root cultures in shake flasks compared with bioreactors.

Obtaining large-scale hairy root cultures is a major challenge to increasing root biomass and secondary metabolite production. Enhanced production of stilbene compounds such as trans-resveratrol, trans-arachidin-1 and trans-arachidin-3 was achieved using an elicitor treatment procedure. Two different hairy root inoculum densities were investigated and compared between shake flask and bioreactor cultures. The lowest growth index was observed using a 20 g/L inoculum size in the bioreactor, which differed significantly from bioreactor of 5 g/L. Increasing the hairy root inoculum size from 5 g/L to 20 g/L in both the shake flask and bioreactor significantly improve antioxidant activity, phenolic content and stilbene compound levels. The highest ABTS and FRAP antioxidant activity, and levels of total phenolic compounds, trans-arachidin-1 and trans-arachidin-3 in the crude extract were demonstrated in shake flask cultures with a 20 g/L inoculum after elicitation for 72 h. The minimum inhibitory concentrations (MICs) of the crude extract to inhibit growth of foodborne microbes, S. aureus, S. typhimurium and E. coli, were 187.5, 250 and 500 µg/mL, respectively. This was due to the ability of the crude extract to disrupt the cell membrane, as observed by scanning electron microscopy (SEM) showing ruptured pores on the S. aureus and S. typhimurium cell surfaces. Moreover, the E. coli cell division process could be inhibited by the crude extract, which promoted an increase in cell size. A DNA nicking assay indicated that a 50 µg/mL concentration of the crude extract caused plasmid DNA damage that might be due to a genotoxic effect of the pro-oxidant activity of the crude extract.