Maximum occlusal force and medial mandibular flexure in relation to vertical facial pattern: a cross-sectional study

BACKGROUND: Vertical facial pattern may be related to the direction of pull of the masticatory muscles, yet its effect on occlusal force and elastic deformation of the mandible still is unclear. This study tested whether the variation in vertical facial pattern is related to the variation in maximum occlusal force (MOF) and medial mandibular flexure (MMF) in 51 fully-dentate adults. METHODS: Data from cephalometric analysis according to the method of Ricketts were used to divide the subjects into three groups: Dolichofacial (n = 6), Mesofacial (n = 10) and Brachyfacial (n = 35). Bilateral MOF was measured using a cross-arch force transducer placed in the first molar region. For MMF, impressions of the mandibular occlusal surface were made in rest (R) and in maximum opening (O) positions. The impressions were scanned, and reference points were selected on the occlusal surface of the contralateral first molars. MMF was calculated by subtracting the intermolar distance in O from the intermolar distance in R. Data were analysed by ANCOVA (fixed factors: facial pattern, sex; covariate: body mass index (BMI); alpha = 0.05). RESULTS: No significant difference of MOF or MMF was found among the three facial patterns (P = 0.62 and P = 0.72, respectively). BMI was not a significant covariate for MOF or MMF (P > 0.05). Sex was a significant factor only for MOF (P = 0.007); males had higher MOF values than females. CONCLUSION: These results suggest that MOF and MMF did not vary as a function of vertical facial pattern in this Brazilian sample

Deoxycholic acid induces the overexpression of intestinal mucin, MUC2, via NF-kB signaling pathway in human esophageal adenocarcinoma cells

<p>Abstract</p> <p>Background</p> <p>Mucin alterations are a common feature of esophageal neoplasia, and alterations in MUC2 mucin have been associated with tumor progression in the esophagus. Bile acids have been linked to esophageal adenocarcinoma and mucin secretion, but their effects on mucin gene expression in human esophageal adenocarcinoma cells is unknown.</p> <p>Methods</p> <p>Human esophageal adenocarcinoma cells were treated 18 hours with 50–300 μM deoxycholic acid, chenodeoxycholic acid, or taurocholic acid. MUC2 transcription was assayed using a MUC2 promoter reporter luciferase construct and MUC2 protein was assayed by Western blot analysis. Transcription Nuclear factor-κB activity was measured using a Nuclear factor-κB reporter construct and confirmed by Western blot analysis for Nuclear factor-κB p65.</p> <p>Results</p> <p>MUC2 transcription and MUC2 protein expression were increased four to five fold by bile acids in a time and dose-dependent manner with no effect on cell viability. Nuclear factor-κB activity was also increased. Treatment with the putative chemopreventive agent aspirin, which decreased Nuclear factor-κB activity, also decreased MUC2 transcription. Nuclear factor-κB p65 siRNA decreased MUC2 transcription, confirming the significance of Nuclear factor-κB in MUC2 induction by deoxycholic acid. Calphostin C, a specific inhibitor of protein kinase C (PKC), greatly decreased bile acid induced MUC2 transcription and Nuclear factor-κB activity, whereas inhibitors of MAP kinase had no effect.</p> <p>Conclusion</p> <p>Deoxycholic acid induced MUC2 overexpression in human esophageal adenocarcinoma cells by activation of Nuclear factor-κB transcription through a process involving PKC-dependent but not PKA, independent of activation of MAP kinase.</p

Cytotoxic isolates of Helicobacter pylori from Peptic Ulcer Diseases decrease K(+)-dependent ATPase Activity in HeLa cells

BACKGROUND: Helicobacter pylori is a Gram negative bacterium that plays a central role in the etiology of chronic gastritis and peptic ulcer diseases. However, not all H. pylori positive cases develop advanced disease. This discriminatory behavior has been attributed to the difference in virulence of the bacteria. Among all virulence factors, cytotoxin released by H. pylori is the most important factor. In this work, we studied variation in H. pylori isolates from Indian dyspeptic patients on the basis of cytotoxin production and associated changes in K(+)-dependent ATPase (one of its targets) enzyme activity in HeLa cells. METHODS: The patients were retrospectively grouped on the basis of endoscopic and histopathological observation as having gastritis or peptic ulcer. The HeLa cells were incubated with the broth culture filtrates (BCFs) of H. pylori isolates from patients of both groups and observed for the cytopathic effects: morphological changes and viability. In addition, the K(+)-dependent ATPase activity was measured in HeLa cells extracts. RESULTS: The cytotoxin production was observed in 3/7 (gastritis) and 4/4 (peptic ulcer) H. pylori isolates. The BCFs of cytotoxin producing H. pylori strains reduced the ATPase activity of HeLa cells to 40% of that measured with non-cytotoxin producing H. pylori strains (1.33 μmole Pi/mg protein and 3.36 μmole Pi/mg protein, respectively, p < 0.05). The decreased activity of ATPase enzyme or the release of cytotoxin also correlated with the increased pathogenicity indices of the patients. CONCLUSIONS: Our results suggest that the isolation of cytotoxic H. pylori is more common in severe form of acid peptic diseases (peptic ulcer) than in gastritis patients from India. Also the cytotoxin released by H. pylori impairs the ion-transporting ATPase and is a measure of cytotoxicity

Reliability of a digital image method for measuring medial mandibular flexure in dentate subjects Confiabilidade de um método de imagem digital para medição de deflexão mandibular medial em adultos dentados

Medial mandibular flexure (MMF) is the functional approximation of hemi-mandibles in jaw opening and protrusion, which may affect conventional or implant-supported arch prostheses. OBJECTIVE: This study evaluated the intra- and inter-rater reliability of a digital image method for linear measurement of MMF in dentate subjects. MATERIAL AND METHODS: Mandibular occlusal impressions in vinyl polysiloxane during rest and maximum opening were obtained from seven adult volunteers. Each impression and the Mitutoyo digital calipers with a 10mm opening were scanned at a 200% magnification. The images were processed using Adobe Photoshop software to get reference points on contralateral first molars. Linear intermolar measurements were taken using the Image Tool software (UTHSCSA), which was calibrated with the standard opening of the digital calipers. Intermolar distance was measured in triplicate for each image by two independent examiners. MMF was calculated by subtracting the intermolar distance in maximum opening (or protrusion) from the distance in rest position. Data were analyzed by intraclass correlation (ICC) tests for estimating intra- and inter-rater reliability. RESULTS: MMF values ranged from -0.21 to 0.44mm. Intra-rater ICCs were 0.982 and 0.993, and inter-rater ICC was 0.696. CONCLUSION: The present results show excellent intra-rater and good inter-rater reliability of this digital image method for measuring MMF in dentate subjects.<br>A deflexão mandibular medial (MMF) é uma deformação funcional que ocorre com a aproximação das hemi-mandíbulas em abertura e protrusão, podendo afetar próteses convencionais e implanto-suportadas em arco. OBJETIVOS: Este trabalho avaliou a confiabilidade intra- e inter-examinador de um método de imagem digital para aferição linear da MMF. MATERIAL E MÉTODOS: Foram selecionados sete voluntários adultos dentados, obtendo-se registros oclusais inferiores de silicona de adição em repouso, abertura e protrusão máximas. Os registros foram escaneados juntamente com um paquímetro Mitutoyo com abertura de 10mm num aumento de 200%. A imagem foi processada no programa Adobe Photoshop obtendo-se pontos de referência intermolares, e as medições lineares foram feitas no programa ImageTool (UTHSCSA) calibrado com a medida padrão do paquímetro. Foram feitas medições em triplicata da medida da distância intermolar para cada imagem. A MMF foi calculada subtraindo-se a distância intermolar em abertura da distância em repouso/ protrusão. Os dados foram analisados por coeficientes de correlação intraclasse (ICC) para estimar a confiabilidade intra- e inter-examinadores. RESULTADOS: Os valores de MMF variaram de -0,21 a 0,44mm. Os ICCs intra-examinador foram 0,982 e 0,993, e o ICC inter-examinador foi 0,696. CONCLUSÃO: Os resultados demonstram excelente confiabilidade intra-examinador e boa confiabilidade inter-examinador deste método de imagem digital para aferição de MMF em adultos dentados