miRNA-101 Targets TGF-ßR1 to Retard the Progression of Oral Squamous Cell Carcinoma.

Despite the considerable knowledge on the involvement of microRNA-101 (miR-101) in the evolution of oral squamous cell carcinoma (OSCC), the underlying mechanisms remain obscure. In this study, miR-101 expression was markedly downregulated in the OSCC cell lines and tissues. Cell counting kit-8 (CCK-8), ethynyl deoxyuridine (EdU), and colony formation assays showed that miR-101 inhibited the proliferation of OSCC cells. Flow cytometry and caspase 3 activity assays indicated that miR-101 induced OSCC cell apoptosis. Transwell assays demonstrated that this miRNA also repressed OSCC cell migration and invasion. Moreover, tube formation assay showed that miR-101 abated the proangiogenesis of OSCC cells. Dual-luciferase reporter assay confirmed that miR-101 directly targeted transforming growth factor-ß receptor 1 (TGF-ßR1) in OSCC. Ectopic expression of TGF-ßR1 counteracted the effects of miR-101 on the OSCC cell characteristics. Thus, miR-101 significantly abolished the proliferation, motility, and proangiogenesis of OSCC cells and induced their apoptosis by targeting TGF-ßR1. These results imply the potential application of miR-101 in OSCC treatment.

Clinical study of root canal numbers in maxillary second primary molars / 口腔疾病防治

Objective@#To investigate the root canal numbers of maxillary second primary molars.@*Methods @#216 max illary second primary molars from 204 children aged 3-8 years old were selected. All the teeth need to do the root canal therapy. After opening the pulp chamber, the root canal were examined and determined with small size K file and 17％ethylene diaminetetraacetic acid (EDTA). Hand instruments were used for root canal preparation and then zinc-oxide iodoform paste was used for filling. @*Results @#216 maxillary second p rimary molars, 122 teeth had three root canals(56.5%), and 94 teeth had four root canals (43.5%). The incidence of second mesiobuccal canal (MB2) was 41.2%. There was no correlation between the incidence of the MB2 canal and gender and tooth position. @*Conclusion@# The root canals of maxillary second primary molars had more variations, and there was a high incidence of the second mesiobuccal canal.

Diversity and population structure of a dominant deciduous tree based on morphological and genetic data.

Knowledge of the genetic diversity and structure of tree species across their geographic ranges is essential for sustainable use and management of forest ecosystems. Acer grosseri Pax., an economically and ecologically important maple species, is mainly distributed in North China. In this study, the genetic diversity and population differentiation of 24 natural populations of this species were evaluated using sequence-related amplified polymorphism markers and morphological characters. The results show that highly significant differences occurred in 32 morphological traits. The coefficient of variation of 34 characters was 18.19 %. Principal component analysis indicated that 18 of 34 traits explained 60.20 % of the total variance. The phenotypic differentiation coefficient (VST) was 36.06 % for all morphological traits. The Shannon-Wiener index of 34 morphological characters was 6.09, while at the population level, it was 1.77. The percentage of polymorphic bands of all studied A. grosseri populations was 82.14 %. Nei's gene diversity (He) and Shannon's information index (I) were 0.35 and 0.50, respectively. Less genetic differentiation was detected among the natural populations (GST = 0.20, ΦST = 0.10). Twenty-four populations of A. grosseri formed two main clusters, which is consistent with morphological cluster analysis. Principal coordinates analysis and STRUCTURE analysis supported the UPGMA-cluster dendrogram. There was no significant correlation between genetic and geographical distances among populations. Both molecular and morphological data suggested that A. grosseri is rich in genetic diversity. The high level of genetic variation within populations could be affected by the biological characters, mating system and lifespan of A. grosseri, whereas the lower genetic diversity among populations could be caused by effective gene exchange, selective pressure from environmental heterogeneity and the species' geographical range.

[Concentration and size distribution of bioaerosols at non-haze and haze days in Beijing].

In recent years, haze has been observed frequently in Beijing. Haze was one of the atmospheric phenomena caused by the accumulation of particulate matter. As an important fraction of particular matter, bioaerosol could potentially cause significantly negative health effects. In this study, we detected the concentration and size distribution of viable bioaerosol during non-haze and haze days, analyzed correlation of viable bioaerosol with the ambient temperature and relative humidity using Spearman's correlation coefficient and finally detected the changing of size distribution of viable bioaerosol in summer and winter. Results indicated that concentrations of viable bioaerosol exhibited a negative correlation with Air Quality Index (AQI) of PM2.5 and positive correlation with temperature. Relative humidity had a negative correlation with airborne bacteria while positive correlation with airborne fungi. The highest concentration of airborne bacteria and fungi were detected at size arrange of 4.5-7.0 µm and 2. 1-3.3 µm in the winter, respectively. In the summer, both the highest concentration of airborne bacteria and fungi were observed at size arrange of 3.3-4.5 µm. The results of this study will provide the basis data for hazard evaluation of bioaerosol on human health at non-haze and haze days.

[Clinical and radiographic study of the fractured immature anterior permanent teeth after pulpotomy].

OBJECTIVE: To observe the outcome of the fractured immature anterior permanent teeth after pulpotomy by X-ray measurement. METHODS: A total of 31 (25 cases) fractured immature anterior permanent teeth after pulpotomy was reviewed. Radiographic measurements were performed on 12 cases with unilateral fractured central incisors and completely formed roots after pulpotomy and 100 (50 subjects) healthy maxillary central incisors. RESULTS: The roots development continued after pulpotomy, and the root length and periapical configuration were both similar to the healthy teeth, but some root canals became narrow or even nearly obturated at the root apex. There was no significant difference in root canal width between healthy right and left maxillary central incisors at the site of 1/4 [right: (0.67 +/- 0.14) mm, left: (0.66 +/- 0.12) mm, P > 0.05], 1/2 [right: (1.05 +/- 0.19) mm, left: (1.04 +/- 0.17) mm, P > 0.05], 3/4 [right: (1.78 +/- 0.34) mm, left: (1.76 +/- 0.30) mm, P > 0.05] of root, but the root canal width of the fractured incisors at the same site was significantly different from that of the contralateral healthy incisor, the 1/4 site pulpotomy: (0.70 +/- 0.23) mm, control: (0.99 +/- 0.17) mm, the 1/2 site pulpotomy: (1.16 +/- 0.24) mm, control: (1.51 +/- 0.25) mm; the 3/4 site pulpotomy: (1.96 +/- 0.34) mm, control: (2.24 +/- 0.36) mm. CONCLUSIONS: There was a tendency that the root canals of fractured teeth after pulpotomy became narrowed and obturated. It should not be followed up for too long to perform root canal treatment when roots completely formed.

[The histological and immunohistochemical manifestation of the immature anterior teeth after pulpotomy].

OBJECTIVE: To observe the histological and immunohistochemical characteristics of the pulp of teeth after pulpotomy. METHODS: Twenty-nine permanent anterior teeth with completely formed roots after pulpotomy due to dental trauma were selected. Thirty permanent premolars with completely formed roots served as control, which were extracted for orthodontic treatment. HE stain and immunohistochemical study of collagen I and collagen III were performed on the root pulp of these two groups. RESULTS: There were degenerative changes in root pulp of the teeth after pulpotomy, such as vacuolization and homogenization of the odontoblasts, cell reduction, fibrosis, hyaline degeneration and calcification. In healthy root pulp, collagen I had a dispersed distribution, calcification substance was stained positive, but collagen III weakly stained in the extreme at peripheric pulp, and calcification substance stained negative. While in pulp of teeth after pulpotomy, both types of collagens had increased expression, fibers aggregated forming thick fiber bundles. In the wall of blood vessels collagen I had increased expression, but collagen III decreased. CONCLUSIONS: The root pulp below dentin bridge after pulpotomy was different from the healthy pulp, and there were some histological degenerative changes in the pulp of the immature anterior teeth after pulpotomy. It is suggested that root canal treatment should eventually be performed on these teeth.