Expression of matrix metalloproteinase-8 and matrix metalloproteinase-13 in mast cells of human periapical lesions.

OBJECTIVE: This study aimed to detect the expression of matrix metalloproteinase-8 (MMP-8) and MMP-13 in mast cells (MCs) of human periapical lesions and to discuss the pathogenic role of MCs in periapical lesions. METHODS: Ninety samples were divided into three groups: (1) periapical granuloma group (n=30); (2) periapical cyst group (n=30); (3) normal periodontal membrane group (n=30). The samples were fixed in 10% neutral formalin for over 48 h and made into serial sections. After H&E staining, histological changes were observed under the optical microscope. Moreover, double immunofluorescence (DIF) staining was performed to detect expression of MMP-8 and MMP-13 in MCs of periapical lesions under the fluorescence microscope. RESULTS: Compared with the normal control group, the number of MMP-8 and MMP-13 double positive MCs in the periapical lesions increased significantly (P<0.01). There was no significant difference in the density of MMP-8 and MMP-13 double positive MCs in the periapical cyst group and periapical granuloma group (P>0.05). CONCLUSION: The number of MCs increased significantly in periapical lesions and there was a considerable increase in the density of MMP-8 and MMP-13 double positive MCs. These results indicate that MCs positive for MMP-8 and MMP-13 might contribute to the pathogenesis of chronic apical periodontitis.

Color-tunable mixed photoluminescence emission from Alq3 organic layer in metal-Alq3-metal surface plasmon structure.

This work reports the color-tunable mixed photoluminescence (PL) emission from an Alq3 organic layer in an Au-Alq3-Au plasmonic structure through the combination of organic fluorescence emission and another form of emission that is enabled by the surface plasmons in the plasmonic structure. The emission wavelength of the latter depends on the Alq3 thickness and can be tuned within the Alq3 fluorescent spectra. Therefore, a two-color broadband, color-tunable mixed PL structure was obtained. Obvious changes in the Commission Internationale d'Eclairage (CIE) coordinates and the corresponding emission colors of Au-Alq3-Au samples clearly varied with the Alq3 thickness (90, 130, and 156 nm).