Haizal Mohd Hussaini

Revisiting the association between candidal infection and carcinoma, particularly oral squamous cell carcinoma

Abstract Background: Tobacco and alcohol are risk factors associated with cancer of the upper aerodigestive tract, but increasingly the role of infection and chronic inflammation is recognized as being significant in cancer development. Bacteria, particularly Helicobacter pylori, and viruses such as members of the human papilloma virus family and hepatitis B and C are strongly implicated as etiological factors in certain cancers. There is less evidence for an association between fungi and cancer, although it has been recognized for many years that white patches on the oral mucosa, which are infected with Candida, have a greater likelihood of undergoing malignant transformation than those that are not infected. Objective: This article reviews the association between the development of oral squamous cell carcinoma in potentially malignant oral lesions with chronic candidal infection and describes mechanisms that may be involved in Candida-associated malignant transformation.

Transcriptional profiling of oral squamous cell carcinoma using formalin-fixed paraffin-embedded samples.

Despite the advances in cancer treatment, the 5-year survival rate for oral cancer has not changed significantly for the past 40 years and still remains among the worst of all anatomic sites. Gene expression microarrays have been used successfully in the identification of genetic alterations in cancer development, however, these have hitherto been limited by the need for specimens with good quality intact RNA. Here, we demonstrated the use of formalin-fixed paraffin-embedded tissues in microarray experiments to identify genes differentially expressed between cancerous and normal oral tissues. Forty-three tissue samples were macrodissected and gene expression analyses were conducted using the Illumina DASL assay. We report RNA yield of 2.4 and 0.8 microg/mm(3) from tumour and normal tissues, respectively and this correlated directly with the tissue volume used for RNA extraction. Using unsupervised hierarchical clustering, distinct gene expression profiles for tumour and normal samples could be generated, and differentially expressed genes could be identified. The majority of these genes were involved in regulation of apoptosis and cell cycle, metastasis and cell adhesion including BCL2A1, BIRC5, MMP1, MMP9 and ITGB4. Representative genes were further validated in independent samples suggesting that these genes may be directly associated with oral cancer development. The ability to conduct microarrays on formalin-fixed paraffin-embedded specimens represents a significant advancement that could open up avenues for finding genes that could be used as prognostication and predictive tools for cancer.

Toll-Like Receptors and Cancer, Particularly Oral Squamous Cell Carcinoma

It is becoming increasingly apparent that the tumor microenvironment plays an important role in the progression of cancer. The microenvironment may promote tumor cell survival and proliferation or, alternatively may induce tumor cell apoptosis. Toll-like receptors (TLRs) are transmembrane proteins, expressed on immune cells and epithelial cells, that recognize exogenous and endogenous macromolecules. Once activated, they initiate signaling pathways leading to the release of cytokines and chemokines, which recruit immune cells inducing further cytokine production, the production of angiogenic mediators and growth factors, all of which may influence tumor progression. This paper examines the actions of TLRs in carcinogenesis with particular emphasis on their role in oral squamous cell carcinoma.

A retrospective study of oral and maxillofacial injuries in Seremban Hospital, Malaysia

INTRODUCTION Aetiology of oral and maxillofacial injuries in this country includes motorvehicle accident (MVA), fall, industrial accidents and others. Among these causes, MVA accident is the predominant cause of injury in Malaysia. MATERIALS AND METHODS A retrospective record review was carried out using hospital records of all patients who sustained oral and maxillofacial injury at the Department of Oral Surgery, Seremban Hospital, Negeri Sembilan, Malaysia between 1998 and 2002. Information related to demographics, aetiology of trauma, vehicles involved in collision, location of injuries and treatment modalities were reviewed. RESULTS Two thousand nine hundred and eighty-six patients sustained oral and maxillofacial injuries. Of these patients, 79.2% were men and the remaining were women. Among all the races, Malays had the highest involvement (50.6%) followed by Indians (24.5%), Chinese (19.6%) and others (5.3%). There were statistically significant results on the association of aetiology and the ethnic groups, in the age group of 30 years or less and male gender (P < 0.001). The most common injury was the soft-tissue injury followed by dental and dentoalveolar injuries and bony fracture. Among all facial fractures, 66.3% were managed conservatively, 13% were treated surgically and 19.7% did not have any intervention. In relation to dental and dentoalveolar injuries, 64.8% had treatment in the form of splinting, restorations or dental extraction. The rest of the patients (35.2%) were referred to their dentists or did not have any active treatment at Seremban Hospital. CONCLUSION Most of the dental and facial injuries in Seremban Hospital were caused by MVA and were predominantly managed using conservative methods.

Toll-like receptor 2 is present in the microenvironment of oral squamous cell carcinoma

Background:The aim of this study was to investigate the expression of toll-like receptor 2 (TLR2) on cells associated with oral squamous cell carcinoma, epithelial dysplasia and irritative hyperplasia, using immunohistochemistry.Results:More immune cells expressed TLR2 in carcinoma and dysplasia than in hyperplasia (P<0.001). No hyperplastic samples showed positive TLR2 staining on keratinocytes, whereas keratinocytes in 64% of cases of carcinoma and 74% of cases of dysplasia were TLR2 positive.Conclusion:Positive TLR2 expression in the microenvironment suggests activation of immune surveillance against the altered epithelium, whereas TLR2 expression by malignant keratinocytes may be indicative of resistance to apoptosis as a pro-survival mechanism.

Facial trauma in geriatric patients in a selected Malaysian hospital

Background:  Road traffic accidents are the main cause of trauma in Malaysia. It has been shown that there was an increase in admissions for trauma patients older than 60 years in the last decade. The purpose of this study was to determine the pattern of maxillofacial injuries in the geriatric patients referred to Seremban Hospital, Malaysia.

Effectiveness of influenza vaccine in preventing influenza-like illness among Faculty of Dentistry staff and students in Universiti Kebangsaan Malaysia

Abstract Influenza is a highly contagious respiratory disease and potentially hazardous for patients and dental personnel in dental clinics. The objective of this study was to evaluate the effectiveness and safety of influenza vaccine among the staff and students of the Faculty of Dentistry, Universiti Kebangsaan Malaysia. The project was conducted from Mayto September 2005. Atotal of 346 participants volunteered for the study and were assigned randomly to a vaccination (170) and control group (176). Participants in the vaccination group were given influenza vaccine for the southern hemisphere season 2005. Demographic data of the participants, data on adverse effects after vaccination and occurrence of influenza-like illness (ILI) were obtained through questionnaires. Results showed that vaccination significantly reduced ILI prevalence by 52.6% ( P =0.002). Frequency of recurrence of the ILI episode, absenteeism and visits to doctors among the vaccinated group were 77.0% ( P =0.031), 76.1% ( P =0.001) and 52.7% ( P =0.004), respectively. Vaccination also provided indirect protection to family members or housemates of the vaccinated participants, with 71.6% effectiveness ( P =0.026). The most common adverse event reported by vaccinated individuals was pain at the site of injection. In conclusion, influenza vaccine is safe and beneficial for dental staff and students. Annual influenza vaccination of dental staff, students and other healthcare workers who have direct contact with patients should be encouraged.

Metastases to the oral region from pleural mesothelioma: Clinicopathologic review.

Malignant mesothelioma is a rare neoplasm that usually develops after exposure to asbestos and particularly involves the pleural cavity. It has a poor prognosis with aggressive local invasion and metastatic spread.

Prevalence of oral cancer, oral potentially malignant disorders and other oral mucosal lesions in Cambodia

ABSTRACT Objectives: To obtain data on the prevalence of oral mucosal lesions (OMLs) among Cambodians, and to assess the relationship between known risk habits of oral diseases with prevalence of oral potentially malignant disorders (OPMDs). Design: This was a population-based, cross-sectional study whereby subjects were adults aged 18 years old and above. A workshop on the identification of OML was held to train and calibrate dental officers prior to data collection in the field. Sociodemographic and risk habits data were collected via face-to-face interview, whilst presence of OML and clinical details of lesions such as type and site were collected following clinical oral examination by the examiners. Data analysis was carried out using the Statistical Package for Social Science (SPSS) version 12.0. The association between risk habits and risk of OPMD was explored using logistic regression analysis. Results: A total of 1634 subjects were recruited. Prevalence of OML for this population was 54.1%. Linea alba was the most common lesion seen (28.7%). This study showed an overall OPMD prevalence of 5.6%. The most common type of OPMD was leukoplakia (64.8%), followed by lichen planus (30.8%). Subjects who only smoked were found to have an increased risk for OPMD of almost four-fold (RR 3.74, 95%CI 1.89–7.41). The highest risk was found for betel quid chewers, where the increased risk observed was more than six times (RR 6.75, 95%CI 3.32–13.72). Alcohol consumption on its own did not seem to confer an increased risk for OPMD, however when practiced concurrently with smoking, a significant risk of more than five times was noted (RR 5.69 95%CI 3.14–10.29). Conclusion: The prevalence of OML was 54.1%, with linea alba being the most commonly occurring lesion. Smoking, alcohol consumption and betel quid chewing were found to be associated with the prevalence of OPMD, which was 5.6%.

Forkhead box-P3+ regulatory T cells and toll-like receptor 2 co-expression in oral squamous cell carcinoma

BACKGROUND The function of forkhead box-P3 (FoxP3) regulatory T cells (Treg) and toll-like receptor (TLR)2 protein in the oral cancer microenvironment is not fully understood, but evidence from other malignancies suggests it is likely they are involved with tumour development and progression. The aim of this study was to investigate the distribution of FoxP3+cells, TLR2+ cells and double-labelled FoxP3+TLR2+ immune cells in oral squamous cell carcinoma (OSCC), using immunohistochemistry (IHC) and immunofluorescence (IF). METHODS 25 archival cases of OSCC were immunostained with anti-FoxP3 and anti-TLR2 antibodies. Inflamed hyperplastic oral mucosal tissues were used as controls. The proportion of single-labelled, double-labelled and negative cells was determined. RESULTS A higher frequency of double-labelled FoxP3+TLR2+ Tregs was observed within the immune cells of OSCC compared to inflamed controls using IHC (p<0.05). Cell-to-cell contact between single-stained TLR2+ cells and FoxP3+ cells was noted. Double IF studies validated demonstration of co-expression of FoxP3+/TLR2+ immune cells in OSCC. CONCLUSION The presence of FoxP3+TLR2+ cells within the OSCC microenvironment may represent a dendritic cell-dependent pathway capable of inhibiting Treg suppressive activity, potentially enhancing the anti-tumour response. Modulation of TLR2-Treg interactions should be further explored to determine if they have a role in the therapeutic management of OSCC.