Morphometric analysis of oral submucous fibrosis and its correlation with histological staging and clinical severity of trismus

AbstractAimTo quantify the histopathological changes in oral submucous fibrosis morphometrically and to correlate those findings with the histological grading and clinical severity of trismus.MethodsA total of hundred histological sections of oral submucous fibrosis were analysed morphometrically by using interactive image analysis system (Image Pro-Plus,V 6.0). Histological staging and the severity of trismus were then compared with the morphometry results. ANOVA and Pearson’s chi square tests were applied using the software SPSS V. 13.0 for statistical analysis.ResultsThe thickness of the epithelium and subepithelial collagen showed no statistically significant differences between the different stages (p value>0.05). However, blood vessel density, mean blood vessel area and mean diameter of the vessels were indirectly proportional to the histological stages (p value<0.001). Histological stages directly correlate the frequency of trismus, but the severity of trismus showed relation neither with the staging nor with the degree of collagenization, measured morphometrically (p value>0.05).ConclusionsThe thickness of the epithelium and subepithelial collagen should not be included in the histological staging criteria of oral submucous fibrosis. Probably the degree of hyalinization of collagen fibres and involvement of muscle fibres are more important in causing trismus, rather than a simple increase in the subepithelial collagen thickness

Conformational stability and thermodynamic characterization of homotetrameric Plasmodium falciparum β-ketoacyl-ACP reductase

The conformational stability of the homotetrameric Plasmodium falciparum β-ketoacyl-ACP reductase (FabG) was determined by guanidinium chloride-induced isothermal and thermal denaturation. The reversible unfolding transitions were monitored by intrinsic fluorescence, circular dichroism (CD) spectroscopy and by measuring the enzyme activity of FabG. The denaturation profiles were analyzed to obtain the thermodynamic parameters associated with unfolding of the protein. The data confirm the simple A4 ↔ 4A model of unfolding, based on the corroboration of CD data by fluorescence transition and similar Δ G estimation for denaturation curves obtained at four different concentration of the FabG. Denaturation is well described by the linear extrapolation model for denaturant-protein interactions. In addition, the conformational stability (Δ Gs) as well as the Δ Cp for the protein unfolding is quite high, 22.68 kcal/mole and 5.83 kcal/(mole K), respectively, which may be a reflection of the relatively large size of the tetrameric molecule (Mr 120, 000) and a large buried hydrophobic core in the folded protein. This study provides a prototype for determining conformational stability of other members of the short-chain alcohol dehydrogenase/reductase superfamily of proteins to which PfFabG belongs