To evaluate whether hepatitis B virus (HBV) preS/S gene variability has any impact on serum hepatitis B surface antigen (HBsAg) levels and to analyze the replication capacity of naturally occurring preS/S variants, sera from 40 untreated patients with HBV-related chronic liver disease (hepatitis B e antigen [HBeAg]-positive, n = 11; HBeAg-negative, n = 29) were virologically characterized. Additionally, phenotypic analysis of three different preS/S variant isolates (carrying a 183-nucleotide deletion within the preS1 region, the deletion of preS2 start codon, and a stop signal at codon 182 within the S gene, respectively) was performed. HBV infecting 14 (35%) patients had single or multiple preS/S genomic mutations (i.e., preS1 and/or preS2 deletions, preS2 start codon mutations, C-terminally truncated and/or “a” determinant mutated S protein). Presence of preS/S variants negatively correlated with HBsAg titers ( r = −0.431; P = 0.005) and its prevalence did not significantly differ between HBeAg-positive and HBeAg-negative patients. No correlation was found between HBsAg and HBV DNA levels in patients infected with preS/S mutants, whereas a significant correlation was found between HBsAg and viremia levels ( r = 0.607; P = 0.001) in patients infected with wild-type HBV strains. HepG2 cells replicating the above-mentioned three preS/S variants showed significant reduction of HBsAg secretion, retention of envelope proteins in the endoplasmic reticulum, less efficient virion secretion and nuclear accumulation of significantly higher amounts of covalently closed circular DNA compared with wild-type HBV replicating cells. Conclusion: In patients infected with preS/S variants, HBV DNA replication and HBsAg synthesis/secretion appear to be dissociated. Therefore, the use of HBsAg titer as diagnostic/prognostic tool has to take into account the frequent emergence of preS/S variants in chronic HBV infection. (HEPATOLOGY 2012;)

Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm²) was similar in coronal zone (46,798±10,644) and apical zone (45,192±10,888), while in the middle zone they were lower in number (30,940±7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system.

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Periodontal disease is characterized by inflammation and bone loss. The balance between inflammatory mediators and their counter-regulatory molecules may be fundamental for determining the outcome of immune pathology of periodontal disease. Cytokines play crucial roles in the maintenance of tissue homeostasis, a process which requires a delicate balance between anabolic and catabolic activities. In particular, two families of growth factors-such as transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF) are thought to play important roles in modulating the proliferation and/or migration of structural cells involved in inflammation and regulation of immune responses. The aim of this work was to analyze gingival samples and periodontal tissue specimens collected from thirty-eight patients with chronic periodontal disease and from forty healthy individuals, in order to detect the expression and distribution of TGF-β1 and VEGF between the two groups. TGF-β1 and VEGF expression levels were detected using immunohistochemical analysis and computer-assisted morphometric analysis. The findings presented here suggest that biomarker such as TGF-β1 and VEGF have an important regulating role in the orchestration of the immune response, which in turn influence the outcome of disease establishment and evolution.