[Show abstract][Hide abstract] ABSTRACT: Aptamers are ssDNA or RNA that binds to wide variety of target molecules with high affinity and specificity produced by systematic evolution of ligands by exponential enrichment (SELEX). Compared to RNA aptamer, DNA aptamer is muchmore stable, favourable to be used in many applications. The most critical step in DNA SELEX experiment is the conversion ofdsDNA to ssDNA. The purpose of this study was to develop an economic and efficient approach of generating ssDNA byusing asymmetric PCR. Our results showed that primer ratio (sense primer:antisense primer) of 20:1 and sense primer amountof 10 to 100 pmol, up to 20 PCR cycles using 20 ng of initial template, in combination with polyacrylamide gel electrophoresis,were the optimal conditions for generating good quality and quantity of ssDNA. The generation of ssDNA via this approachcan greatly enhance the success rate of DNA aptamer generation
Full-text · Article · Apr 2012 · Songklanakarin Journal of Science and Technology
[Show abstract][Hide abstract] ABSTRACT: This study aims to evaluate the cytotoxicity of a new fast set highly viscous conventional glass ionomer cement (GIC) with L929 fibroblasts.
The cement capsule was mixed and introduced into a paraffin wax mould. After setting, the cement was incubated in Dulbecco's Modified Eagle's Medium. Six replicates of the material extract were added to the culture medium in 96-well plates. L929 mouse fibroblast cells were added into the wells and then incubated for 48 h. Dimethylthiazol diphenyltetrazolium bromide test was performed for cytotoxicity evaluation.
The results showed that this GIC brand did not yield a half-maximal inhibitory concentration value, IC50, as the cell viability was above 50% at all concentrations. Cell viability over 90% was observed at the concentrations of 3.125 and 1.5625 mg/ml. Maximum concentration of the material showed cell viability of 59.4%.
This new fast set highly viscous conventional GIC showed low cytotoxicity to mouse fibroblast cells, and it can be suggested as a substitute for dental cements exhibiting a long setting time.
Full-text · Article · Oct 2011 · Journal of Conservative Dentistry
[Show abstract][Hide abstract] ABSTRACT: his study evaluated and compared the setting time and handling properties of white mineral trioxide aggregate (WMTA) and calcium chloride dihydrate (CaCl2•2H2O), when mixed with manuka honey, tualang honey, propolis and royal jelly. WMTA, CaCl2•2H2O and sterile water were mixed with various bee products and the mixtures were immediately transferred to stainless steel ring moulds and placed on an electronic weighing scale. Vertical load of 300-400 g was applied for 5 seconds to create indentations, which were examined under magnification and setting time was then calculated. Handling properties were observed during mixing and transferring of materials. WMTA was mixed with sterile water and this served as a negative control. WMTA mixed with CaCl2•2H2O and sterile water served as a positive control. Setting time and handling properties of various groups were compared with the control groups.
In terms of setting time, tualang honey showed the best results with a setting time range of 17-20 minutes followed by manuka honey in the range 29-36 minutes. Royal jelly was in the range of 76-86 minutes. Setting time with propolis mix was the highest being in the range of 125-152 minutes. Handling properties, which were compromised in both positive and negative control groups, were better with tualang honey, manuka honey and propolis. Results of this study suggest that handling properties were enhanced on adding tualang honey and manuka honey to WMTA and CaCl2•2H2O mix without a significant change in the setting time, as compared to the positive control.
Erratum: P.126: 2nd paragraph, 4th sentence should read: "This formulation of calcium chloride was chosen due to its reduced hygroscopic nature, which provides adequate time for the weighing of granules before adding them to MTA powder (as being less hygroscopic they would not absorb water so fast, which otherwise could lead to change in their state and also may cause an error in their weight)".
Full-text · Article · Aug 2011 · Journal of ApiProduct and ApiMedical Science
[Show abstract][Hide abstract] ABSTRACT: Aim: To determine the prevalence of human papillomavirus in the oral cavity of denture wearers.
Methods: Swabs were collected from 72 denture wearers and 72 controls (non-denture wearers) to obtain DNA. Amplification of the β-globin gene was performed by polymerase chain reaction to check the integrity of extracted DNA. The presence of human papillomavirus in the DNA sample was detected by nested polymerase chain reaction.
Results: The prevalence of human papillomavirus was found to be significantly higher in the oral cavity of denture wearers (38/72, 52.8%) than in the controls (17/72, 23.6%; odds ratio = 3.612, confidence interval = 1.771/7.385, P = <0.001). When adjusted for variables, including age, sex, ethnicity, and smoking habit, human papillomavirus was still found to be significantly associated with denture wearing, with an adjusted odds of 3.2 (P = 0.008). No association of human papillomavirus positivity was found with denture variables, including denture type, denture material type, duration of denture wearing, and denture hygiene (P > 0.05). Low-risk human papillomavirus types were found to be more frequent in both groups.
Conclusions: The prevalence of human papillomavirus in the oral cavity of denture wearers was found to be significantly higher compared to controls; however, it was mainly low-risk types.
No preview · Article · Jun 2011 · Journal of investigative and clinical dentistry
[Show abstract][Hide abstract] ABSTRACT: The treatment of oral squamous cell carcinomas (OSCC) and human osteosarcoma (HOS) includes surgery and/or radiotherapy which often lead to reduced quality of life. This study was aimed to study the antiproliferative activity of local honey (Tualang) on OSCC and HOS cell lines.
Several concentrations of Tualang honey (1% - 20%) were applied on OSCC and HOS cell lines for 3, 6, 12, 24, 48 and 72 hours. Morphological characteristics were observed under light and fluorescent microscope. Cell viability was assessed using MTT assay and the optical density for absorbance values in each experiment was measured at 570 nm by an ELISA reader. Detection of cellular apoptosis was done using the Annexin V-FITC Apoptosis Detection Kit.
Morphological appearance showed apoptotic cellular changes like becoming rounded, reduction in cell number, blebbed membrane and apoptotic nuclear changes like nuclear shrinkage, chromatin condensation and fragmented nucleus on OSCC and HOS cell lines. Cell viability assay showed a time and dose-dependent inhibitory effect of honey on both cell lines. The 50% inhibitory concentration (IC50) for OSCC and HOS cell lines was found to be 4% and 3.5% respectively. The maximum inhibition of cell growth of ≥80% was obtained at 15% for both cell lines. Early apoptosis was evident by flow cytometry where percentage of early apoptotic cells increased in dose and time dependent manner.
Tualang honey showed antiproliferative effect on OSCC and HOS cell lines by inducing early apoptosis.
Full-text · Article · Sep 2010 · BMC Complementary and Alternative Medicine
[Show abstract][Hide abstract] ABSTRACT: This study was aimed to determine the prevalence of oral mucosal lesions (OML) in patients with diabetes mellitus (DM) and non-diabetic subjects without any oral habits and to investigate the association of DM with oral precancerous lesions.
This cross-sectional study involved 420 diabetic and 420 non-diabetic control subjects without any oral habits. Detailed oral examination was performed based on international criteria.
A significantly greater proportion of subjects with DM (45%) had one or more OML in comparison to non-diabetics (38.3%). Patients with DM showed a significantly greater prevalence of geographic tongue, denture stomatitis and angular cheilitis than non-diabetics (p<0.05). The results also showed an association between occurrence of one or more OML and metabolic control of diabetic patients (p<0.05). For precancerous lesions, lichen planus was found in two diabetic patients while none of controls had any precancerous lesion (p>0.05).
Prevalence of OML was significantly higher in diabetic patients than non-diabetics and this prevalence was associated with the metabolic control of the patients. However, no association was observed between DM and oral precancerous lesions.
No preview · Article · Sep 2010 · Diabetes research and clinical practice
[Show abstract][Hide abstract] ABSTRACT: Association of High-risk Human Papillomavirus (HR-HPV) with oral cancer has been established recently. Detecting these viruses in oral cavity is important to prevent oral lesions related to them. The purpose of this study was to evaluate the prevalence of HR-HPV in the oral cavity of women with cervical cancer, and their children. A total of 70 women, previously diagnosed with cervical cancer, and 46 children of these women, born by vaginal delivery only, were selected for this study. Buccal swabs were collected from their oral cavity and HPV detection was carried out using Hybrid Capture 2 high-risk HPV (HC2 HR-HPV) detection system.
Out of 70 women with cervical cancer, four (5.71%) were found to be positive for HR-HPV in their oral cavity. No association of HR-HPV was found with sociodemographic profile, marital status, reproductive history, tobacco and alcohol usage, contraceptive pills usage, and presence of oral lesions (p>0.05). Among children, HR-HPV in the oral cavity was detected in only 1 of the 46 subjects examined (2.17%). Clinically healthy oral mucosa, without any oral lesions, was observed in all the HR-HPV positive subjects.
The result of this study showed that there is low, if any, risk of HR-HPV infection in the oral cavity of women with cervical cancer. Further, our study suggests that there is very low risk for children of women with cervical cancer, to acquire and sustain HR-HPV in their oral cavity until childhood or adolescence.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to evaluate the role of HPV and p53 polymorphisms in oral squamous cell carcinomas (OSCC) affecting Malaysian population.
We analysed frozen samples from 105 OSCC as well as 105 oral specimens derived from healthy individuals. PCR assays targeting two regions of the virus were used. PCR amplification for the analysis of p53 codon 72 arginine/proline alleles was carried out in a separate reaction.
HPV DNA was detected in 51.4% OSCC samples, while 24.8% controls were found to be HPV positive. HPV was found to be significantly associated with OSCC (P < 0.001, OR = 4.3 after adjustment for habits) when compared to controls. High-risk HPV was found to be significantly associated with OSCC cases (P < 0.05). Demographic profiles of age, gender, race and habits were not associated with HPV presence in cases and controls. However, significantly less HPV positivity was seen in poorly differentiated compared to well-differentiated OSCCs. No significant association was found between HPV positivity and p53 polymorphisms in cases and control groups. Additionally, we found no association of codon 72 polymorphism with oral cancer.
This study indicates that high-risk HPV infection is one of the contributing factors for OSCCs. HPV 16 was the predominant type found in Malaysian patients with OSCC. Further, we did not find any association between p53 codon 72 polymorphism and HPV infection or between the p53 polymorphism and the risk of oral cancer.
No preview · Article · Apr 2010 · Journal of Cancer Research and Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: There is a growing appreciation of the potential value for routine screening for the presence of HPV not only for cervical specimens but also from oral cavity. The purpose of this study was to develop and clinically evaluate a single-tube seminested PCR assay for the detection of HPV. Several parameters such as PCR primers, primer annealing temperature, the number of PCR cycles and concentration of PCR components were optimized. The assay was evaluated using HPV inserts of type 6, 11, 16, 18, 31, 33, 38 and 51. Evaluation of seminested PCR assay was performed with cervical scrapings from 30 patients and buccal swabs from 30 head and neck cancer patients and results were compared with those of two-tube nested PCR. The results were found to be comparable with a total of 60% (36/60) of samples being positive for HPV using the single-tube assay, while 62% (37/60) positivity was found with two-tube PCR assay. We succeeded in developing a single-tube seminested PCR method for HPV DNA detection which is easier than the conventional nested PCR and can be further evaluated as a potential screening tool for detecting HPV in oral and cervical regions.
Full-text · Article · Feb 2009 · The Open Microbiology Journal
[Show abstract][Hide abstract] ABSTRACT: The main objective of a root end filling material is to provide an apical seal that prevents the movement of bacteria and the diffusion of bacterial products from the root canal system into periapical tissues. The aim of this study was to compare the microleakage of three root end filling materials Mineral trioxide aggregate (MTA), Glass ionomer cement (GIC) and Silver GIC (Miracle Mix) using dye penetration technique under stereomicroscope. Forty-five extracted human maxillary central incisors were instrumented and obturated with gutta percha using lateral compaction technique. Following this, the teeth were stored in saline. After one week, teeth were apically resected at an angle of 90° to the long axis of the root and root end cavities were prepared. The teeth were divided into three groups of fifteen specimens each and were filled with Group I -MTA, Group II - GIC and Group III - Miracle Mix. The samples were coated with varnish and after drying, they were immersed in 1% methylene blue dye for 72 hours. The teeth were then rinsed, sectioned longitudinally and observed under stereomicroscope. The depth of dye penetration was measured in millimeters. Microleakage was found to be significantly less in MTA (0.83 mm) when compared to GIC (1.32 mm) (p < 0.001) and with Miracle Mix (1.39 mm) (p < 0.001) No significant difference was found when microleakage in Miracle Mix was compared to that of GIC (p = 0.752). Thus we concluded that MTA is a better material as root end filling material to prevent microleakage, in comparison to GIC and Miracle Mix.
[Show abstract][Hide abstract] ABSTRACT: In order to investigate the reliability of detecting HPV DNA in cervical smears, we compared the performance of nested MY/GP PCR and FDA approved-Hybrid Capture II (HCII) using clinical cervical scrapings from 40 patients. It was found that PCR was more sensitive (81.8%) in comparison to HCII (36.4%) in detecting HPV although specificity of HCII was much higher (96.6%) than PCR (58.6%). The Negative Predictive Value (NPV) of both the techniques were quite similar but Positive Predictive Value (PPV) of HCII was much higher (80.0%) compared to PCR (42.9%). While the HCII method showed good specificity for HPV detection, its lack of sensitivity as compared to PCR may be a drawback for diagnostic use.
Full-text · Article · Sep 2007 · The Medical journal of Malaysia
[Show abstract][Hide abstract] ABSTRACT: Chondrosarcomas are malignant tumours of cartilaginous origin. They range from a well-differentiated growth resembling a benign cartilage tumour to a high-grade malignancy with aggressive local behaviour and the potential to metastasize. Only 5% to 10% of chondrosarcomas are known to occur in the head and neck region. A case of chondrosarcoma of the anterior region of the mandible is presented, along with a review of the relevant literature.
[Show abstract][Hide abstract] ABSTRACT: Lack of awareness of signs and symptoms and risk factors of oral cancer can lead to late presentation of the disease that contributes to poor survival of patients who contract it. This study aims to determine the level of awareness regarding oral cancer in adult patients attending School of Dental Sciences, Universiti Sains Malaysia.
This was a cross-sectional study in which face-to-face interview of 108 subjects aged 20-65 was conducted. The questionnaire consisted of personnel details and questions regarding awareness of risk factors, complications, signs and symptoms, and prevention of oral cancer. Each response was assigned scores where one (1) mark was given for a correct answer and one (1) mark was subtracted for every wrong answer. The scores were added up to obtain total individual score.
Majority of the patients interviewed were from the age range of 20-29. Most of the respondents were Malays with females having a higher percentage (52.8%) than males (47.2%). Majority of the patients (89.9%) were aware regarding the presence of the oral cancer. However, there was no significant association of age range and gender (p > 0.05). 96.7% of subjects who have had higher education were significantly more aware about the presence of oral cancer when compared to those without any schooling (p < 0.05). There was a high awareness of the link between smoking, tobacco chewing, betel nut chewing, and alcohol (93.5%, 85.2%, 75.9%, and 68.5%, respectively) with oral cancer. Almost three-fourth (73%) scored between 10 and 19 out of the maximum of 23 with the mean score of 13.4 (standard deviation, 4.37). All our subjects agreed that early detection of oral cancer could improve chances of successfully treating them.
There was a moderate level of awareness regarding oral cancer towards its risk factors, complications, signs and symptoms, and prevention of oral cancer.
No preview · Article · Jan 2007 · Singapore dental journal