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INTRODUCTION: The three common odontogenic cysts include radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs). Among these 3 cysts, OKC is recently been classified as benign keratocystic odontogenic tumor attributing to its aggressive behavior, recurrence rate, and malignant potential. The present study involved qualitative and quantitative analysis of inducible nitric oxide synthase (iNOS) expression in epithelial lining of RCs, DCs, and OKCs, compare iNOS expression in epithelial linings of all the 3 cysts and determined overexpression of iNOS in OKCs which might contribute to its aggressive behavior and malignant potential. AIMS: The present study is to investigate the role of iNOS in the pathogenesis of OKCs, DCs, and RCs by evaluating the iNOS expression in the epithelial lining of these cysts. SUBJECTS AND METHODS: Analysis of iNOS expression in epithelial lining cells of 20 RCs, 20 DCs, and 20 OKCs using immunohistochemistry done. STATISTICAL ANALYSIS USED: The percentage of positive cells and intensity of stain was assessed and compared among all the 3 cysts using contingency coefficient. Kappa statistics for the two observers were computed for finding interobserver agreement. RESULTS: The percentage of iNOS-positive cells was found to be remarkably high in OKCs (12/20) -57.1% as compared to RCs (6/20) - 28.6% and DCs (3/20) - 14.3%. The interobserver agreement for iNOS-positive percentage cells was arrived with kappa values with OKCs â Statistically significant (P > 0.000), RCs â statistically significant (P > 0.001) with no significant values for DCs. No statistical difference exists among 3 study samples in regard to the intensity of staining with iNOS. CONCLUSIONS: Increased iNOS expression in OKCs may contribute to bone resorption and accumulation of wild-type p53, hence, making OKCs more aggressive.
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BACKGROUND: Mucins alteration in glycosylation is associated with the development and progression of malignant diseases. Therefore, mucins are used as valuable markers to distinguish normal and disease conditions. Many studies on MUC1 expression have been conducted on variety of neoplastic lesions other than head and neck region. None of the study has made an attempt to show its significance in potentially malignant disorders (PMDs) and oral squamous cell carcinoma (OSCC). Hence, ours is one of the pioneer studies done to assess and evaluate the same. AIMS: This study aims to compare and correlate the expression of MUC1 mucin protein in normal oral mucosa (NOM), PMD's and OSCC by immunohistochemical method. MATERIALS AND METHODS: Institutional study, archived tissue sections of OSCC (n = 20), PMD's (n = 20) and NOM (n = 20) were immunostained for MUC1 mucin and percentage of positive cells evaluated. Results obtained were statistically analyzed using Kruskal-Wallis test, Mann-Whitney test and Student's t-test. RESULTS: The mean MUC1 mucin positive cells in the study groups were as follows, 40% in OSCC, 28% in PMD's and 0.75% in NOM. Higher mean immunohistochemical score was observed in OSCC group followed by PMD's group and NOM group. The difference in immunohistochemical score among the groups was found to be statistically significant (P < 0.001). CONCLUSION: The result of the current study suggests that determination of MUC1 mucin expression may be a parameter in the diagnosis of malignant behavior of PMD's to OSCC. MUC1 mucin expression may be a useful diagnostic marker for prediction of the invasive/metastatic potential of OSCC.
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BACKGROUND: Telomerase is an RNA-dependent DNA polymerase that synthesizes TTAGGG telomeric DNA sequences and almost universally provides the molecular basis for unlimited proliferative potential. The telomeres become shorter with each cycle of replication and reach a critical limit; most cells die or enter stage of replicative senescence. Telomere length maintenance by telomerase is required for all the cells that exhibit limitless replicative potential. It has been postulated that reactivation of telomerase expression is necessary for the continuous proliferation of neoplastic cells to attain immortality. Use of immunohistochemistry (IHC) is a useful, reliable method of localizing the human telomerase reverse transcriptase (hTERT) protein in tissue sections which permits cellular localization. Although there exists a lot of information on telomerase in oral cancer, little is known about their expression in oral epithelial dysplasia and their progression to oral squamous cell carcinoma (OSCC) compared to normal oral mucosa. This study addresses this lacuna. AIMS: To compare the expression of hTERT protein in oral epithelial dysplasia and OSCC with normal oral mucosa by Immunohistochemical method. SUBJECTS AND METHODS: In this preliminary study, IHC was used to detect the expression of hTERT protein in OSCC (n = 20), oral epithelial dysplasia (n = 21) and normal oral mucosa (n = 10). The tissue localization of immunostain, cellular localization of immunostain, nature of stain, intensity of stain, percentage of cells stained with hTERT protein were studied. A total number of 100 cells were counted in each slide. STATISTICAL ANALYSIS: All the data were analyzed using SPSS software version 16.0. The tissue localization, cellular localization of cytoplasmic/nuclear/both of hTERT stain, staining intensity was compared across the groups using Pearson's Chi-square test. The mean percentage of cells stained for oral epithelial dysplasia, OSCC and normal oral mucosa were compared using analysis of variance (ANOVA). A P < 0.05 was considered to be statistically significant. RESULTS: The mean hTERT positive cells in the study groups were as follows, 62.91% in normal oral mucosa samples, 77.06% in oral epithelial dysplasia cases, and 81.48% in OSCC. In 61.9% of oral epithelial dysplasia and 65% of OSCC in our study, staining was visualized within the nucleus predominantly in the dot like pattern. There was a statistically significant difference in the nature of nuclear stain between oral epithelial dysplasia and OSCC (P = 0.023). CONCLUSIONS: Our results suggests that the mean percentage of cells showing hTERT expression steadily increased from normal oral mucosa to oral epithelial dysplasia to OSCC. The steady trend of increase in the percentage of cells was evident in different grades of oral epithelial dysplasia group and OSCC. The nature of hTERT staining did show variations among the three groups and promise to be a potential surrogate marker for malignant transformation. Further studies using IHC on larger sample size and clinical follow-up of these patients will be ascertaining the full potential of hTERT as a surrogate marker of epithelial transformation.
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CONTEXT: Onychophagia or habitual nail-biting is widespread among children and adolescents, between 10 and 18 years. Prevalence estimates range from 30% during childhood to 45% in adolescence. Nail-biting habit can result in autoinoculation of pathogens and transmission of infection between body parts. AIMS: The purpose of the study was to evaluate the differences in prevalence of Enterobacteriaceae (E. coli and Enterobacter spp) in saliva samples from subjects with and without chronic nail-biting habit. SUBJECTS AND METHODS: One hundred and twenty-two subjects with chronic nail-biting habit and 122 subjects with no oral habit were enrolled in the study. All subjects were aged 11-15 years. The saliva samples were collected by oral rinse technique, samples were studied microbiologically. STATISTICAL ANALYSIS USED: Two-tailed Student's t-test and Chi-square/Fisher's exact test were used to find the significance of study parameters between the groups. RESULTS: Enterobacteriaceae were detected in the saliva samples of 80 of the 122 nail-biting subjects, whereas Enterobacteriaceae were detected in the saliva samples of only 10 of the 122 subjects who were not nail-biters. This difference in prevalence was statistically significant (P < 0.001). CONCLUSIONS: Our results suggest a higher carriage of Enterobacteriaceae in the individuals having nail-biting habits when compared to individuals with no habits. Further studies need to be done to know the prevalence of Enterobacteriaceae species in different age groups.
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CONTEXT: In routine histopathology, decalcification of bone and teeth is often an essential and important step during tissue processing. Various decalcifying agents have been used in the past. The rate of decalcification and the effect of decalcifying agents on the tissue and its staining characteristics are two important parameters which influence the selection of decalcifying solutions. Though some agents remove the calcium ions completely and rapidly, they adversely affect the staining characteristics and may also damage the organic components. There have been very few studies which have systematically evaluated the efficacy of these agents in decalcifying dental hard tissues. AIMS: The present study was done to evaluate the rate of decalcification of six different decalcifying agents and also their effect on staining characteristics on dental hard tissues. MATERIALS AND METHODS: Six decalcifying agents namely, neutral ethylene diamine tetra acetic acid (EDTA) decalcifying solution, 5% nitric acid, Perenyi's fluid, formalin-nitric acid, 5% trichloracetic acid, and 10% formic acid were used to decalcify 24 natural teeth (four in each solution). The endpoint of decalcification was evaluated by radiographic and chemical methods. The decalcified teeth were then routinely processed, sectioned, and stained with hematoxylin and eosin stains. RESULTS: Neutral EDTA was the most considerate to the soft and hard tissues and 5% nitric acid was the least considerate to the tooth structure. CONCLUSIONS: Neutral EDTA, though being the slowest decalcifying agent among the six agents used in the study, gave excellent results for soft-tissue integrity, and best quality of both soft-tissue and hard-tissue stainings.
