Senescence in oral lichen planus as assessed by the immunohistochemical evaluation of senescence marker protein-30 (Regucalcin).

Background: Oral lichen planus is a T-cell-mediated chronic inflammatory disease affecting approximately 1% to 2% of the population, the etiology of which is currently unknown. The objectives of this study were to observe if senescence occurs in oral lichen planus, through the assessment of the immunohistochemical expression of a novel marker for senescence called Senescence marker protein-30 or regucalcin, and compare the expression to that in oral lichenoid reaction and non-specific inflammation. Subjects and Methods: The study material consisted of 30 cases of oral lichen planus, 15 cases of oral lichenoid reaction and 15 cases of non-specific inflammation. The number of positive cells in ten randomly selected high power fields were counted in the epithelium and the connective tissue separately and the mean was determined. Results: Mann-Whitney U test was used to statistically analyze if there was any significant difference in the expression of Senescence marker protein-30 between oral lichen planus, oral lichenoid reaction and non-specific inflammation. Even though a greater expression was seen in the oral lichen planus cases than oral lichenoid reaction, the difference in both the epithelium and connective tissue was not statistically significant. Conclusion: This study shows that in addition to the already known mechanisms like apoptosis and increased cell proliferation rates, the activated T-lymphocytes may also trigger a senescent change in the cells of oral lichen planus. As with the other mechanisms, this is also seen only in a small proportion of the cases.

Evidence of Extended Thermo-Stability of Typhoid Polysaccharide Conjugate Vaccines.

Typhoid conjugate vaccines (TCV) are effective in preventing enteric fever caused by Salmonella enterica serovar Typhi in Southeast Asia and Africa. To facilitate vaccination with the Vi capsular polysaccharide-tetanus toxoid conjugate vaccine, Typbar TCV, and allow it to be transported and stored outside a cold chain just prior to administration, an extended controlled-temperature conditions (ECTC) study was performed to confirm the quality of the vaccine at 40 °C for 3 days at the end of its shelf-life (36 months at 2-8 °C). Studies performed in parallel by the vaccine manufacturer, Bharat Biotech International Limited, and an independent national control laboratory (NIBSC) monitored its stability-indicating parameters: O-acetylation of the Vi polysaccharide, integrity of the polysaccharide-protein conjugate, and its molecular size and pH. ECTC samples stored at 40 °C and 45 °C in comparison with control samples stored at 4 °C and 55 or 56 °C, were shown to have stable O-acetylation and pH; only very slight increases in the percentage of free saccharide and corresponding decreases in molecular size were observed. The deoxycholate method for precipitating conjugated polysaccharide was very sensitive to small incremental increases in percentage of free saccharide, in line with storage temperature and duration. This extended ECTC study demonstrated minimal structural changes to the Vi polysaccharide and conjugate vaccine and a stable formulation following extended exposure to elevated temperatures for the desired durations. This outcome supports the manufacturer's ECTC claim for the vaccine to be allowed to be taken outside the cold chain before its administration.

An In Vitro Comparative Evaluation of Shear Bond Strengths of Veneering Porcelain and Different Core Materials.

AIM: The aim of the present study was to evaluate and compare the bond strengths of different core structures to veneering porcelain. MATERIALS AND METHODS: Sixty specimens were divided into 4 groups of 15 each. Specimen fabrication was done according to the International Organization for Standardization (ISO) specifications 9693:1999. Group 1 comprised core structure made of cast alloy, group 2 from sintered metal, group 3 from milled zirconia and group 4 milled zirconia without liner at the interface. The shear bond strengths were recorded and the values obtained were statistically examined. RESULTS: Highest values were recorded in group 3 and there were significant differences between groups 1 and 3 while groups 3 and 4 were not statistically different. This led us to imply that zirconia as a core structure provided maximum strengths and laser sintered metal came second. The results also pointed out that the role of the zirconia liner is not that crucial to attaining adequate strength. CONCLUSION: The present study concluded that zirconia and laser sintered metal are excellent core materials and feasible alternatives to cast alloy. We also concluded from our study that a zirconia liner did not affect the bond strength significantly and is not absolutely essential. CLINICAL SIGNIFICANCE: This study helps us to understand the role of materials used as core structures in enhancing the shear bond strength to veneer porcelains and also clarifies the role of a zirconia liner in the process.

Assessment of Tumor Associated Tissue Eosinophilia (TATE) in Oral Squamous Cell Carcinoma Using Carbol Chromotrope Stain / Evaluación de la Eosinofilia Tisular Asociada al Tumor (TATE) en el Carcinoma Oral de Células Escamosas Mediante la Tinción de Carbol Cromótropo

Tumor related tissue eosinophilia (TATE) is a known phenomenon but its role in prognostics and correlation with size of the primary tumor is still controversial. Using a stain, like Carbol chromotrope, that targets eosinophils exclusively and vividly, offers an advantage over haematoxylin and eosin, which was used in most of the studies. Forty-nine cases of oral squamous cell carcinoma, where the TNM staging has been recorded in their history, was taken and stained with Lendrum's carbol chromotrope. Significant difference in the eosinophil count with varying size of the tumor and a parallel increase in the number noted, with increase in size. There is a corresponding increase in the number of eosinophils infiltrating the tumor with increase in size of oral squamous cell carcinoma.

La eosinofilia tisular asociada a tumores (TATE) es un fenómeno conocido, sin embargo su pronóstico y correlación con el tamaño del tumor primario aún es tema de controversia. El uso de cromotropo como tinción dirigida exclusivamente a los eosinófilos, ofrece una ventaja sobre la hematoxilina-eosina, que ha sido utilizada en la mayoría de los estudios. Se estudiaron células escamosas en 49 casos de carcinoma oral, con registro del estadio TNM. Las células fueron teñidas con carbol cromotropo de Lendrum. Se observó una diferencia significativa en el recuento de eosinófilos con el tamaño del tumor y un aumento paralelo en número, con el aumento de tamaño. Hay un aumento correspondiente en el número de eosinófilos que infiltran el tumor con aumento en el tamaño de carcinoma de células escamosas orales.