[Changes in the expression of Dlx5, Msx2, and Dlx5/Msx2 in hPDLSCs loaded with cyclic tensile stress].

OBJECTIVE: To investigate the changes in the expression of Dlx5 and Msx2 in human periodontal ligament stem cells (hPDLSCs) loaded with cyclic tensile stress. METHODS: hPDLSCs were subjected to cyclic tensile stress (0.5 Hz, 3000 microm strain) for 3, 6, 12, 24 h through a four-point bending strain system. The expressions of Dlx5 and Msx2 mRNA were determined by real time PCR. RESULTS: Strong expressions of Dlx5 and Msx2 were found in the periodontal fibroblasts of the tension side 20 minutes after mechanical loading. The expression of Dlx5 mRNA decreased over time with the stress. The expression of Msx2 mRNA increased over time with the stress. CONCLUSION: Both Dlx5 and Msx2 are sensitive to mechanical stress. Cyclic tensile stress may induce differentiating of hPDLSCs towards mineralized tissue cells by promoting Dlx5 mRNA expression and decreasing Msx2 expression.

Large-scale survey of a neglected agent of sparganosis Spirometra erinaceieuropaei (Cestoda: Diphyllobothriidae) in wild frogs in China.

BACKGROUND: In China, frogs play an understudied role in the spread of human sparganosis (caused by the larval form of Spirometra). However, our knowledge about the prevalence of sparganum infection in frogs remains fragmented, and the taxonomic identification of the parasite is still controversial. METHODOLOGY/PRINCIPAL FINDINGS: The prevalence of sparganum infection in wild frogs was surveyed at 145 geographical locations from 28 of the 34 provinces/autonomous regions/municipalities in China for six years. The collected sparganum isolates from the different locations were subjected to molecular identification by a multiplex PCR assay and then were analysed with clustering analysis. In the survey, sparganum infection was found in 8 out of 13 of the collected frog species, and the most frequently infected species was Pelophylax nigromaculatus (the infection rate was up to 14.07%). Infected frogs were found in 80 of the 145 surveyed locations. The sparganum infection rates in the wild frogs in several regions of China were still high (above 10%), especially in South and Southwest China. A total of 72 spargana were selected for molecular identification, and the clustering analysis showed that sequences from the Chinese isolates were very similar to those identified as from Spirometra erinaceieuropaei. However, the taxonomy of the genus remains confused and further analysis is required. CONCLUSIONS: Eating wild frogs is associated with considerable health risks in China. Several traditional Chinese folk remedies may increase the risk of infection. The sparganum isolates in China are most likely from S. erinaceieuropaei, but new studies, especially comprehensive morphological analyses, are needed in the future.

[Distal horizontal impaction of right mandibular first molar: a case report].

Impacted molars are more common in maxillary and mandibular third molars, whereas impacted first molars are relatively rare. A case of horizontal impaction of mandibular first molar is reported in this study, and the relevant literature are presented.