Evaluation of conditioned medium from placenta-derived mesenchymal stem cells as a storage medium for avulsed teeth: An in vitro study.

BACKGROUND/AIM: The viability of periodontal ligament cells on the root surface is a major factor that influences the healing of replanted teeth. A suitable storage medium is necessary to preserve avulsed teeth before replantation. Conditioned medium from placenta-derived mesenchymal stem cells (PMSC-CM) contains a variety of growth factors. The aim of this study was to evaluate the effectiveness of PMSC-CM as a storage medium to maintain the cell viability of avulsed teeth. MATERIAL AND METHODS: Extracted premolars from healthy humans were randomly stored in Hank's balanced salt solution (HBSS) and PMSC-CM for 6, 12 and 24 hours, respectively, at room temperature, and then the ratio of apoptosis of the periodontal ligament (PDL) cells was identified by flow cytometry. Human periodontal ligament stem cells (PDLSCs) were incubated with HBSS and PMSC-CM, respectively, for 6, 12, 24 and 48 hours in 5% CO2 at 37°C. Then, the cell viability of PDLSCs was determined using the cell counting kit-8 (CCK-8) and a cell cycle assay was performed. RESULTS: The apoptosis rate of PDL cells in PMSC-CM was significantly lower than that in HBSS at 24 hours (P < .001), while the two groups showed similar cell apoptosis rates at 6 and 12 hours (P > .05). The cell proliferation of PDLSCs treated with PMSC-CM significantly increased compared with the HBSS group (P < .05). The cell cycle assay revealed that the PDLSCs treated with HBSS were arrested at the G1 phase, while there was no difference between the PMSC-CM group and the control group (P > .05). CONCLUSIONS: Compared with HBSS, PMSC-CM showed better inhibition of apoptosis of PDL cells and promoted the proliferation of PDLSCs. Thus, PMSC-CM could be a promising storage medium for avulsed teeth.

Characterization of the changes in comparative genomic hybridization in esophageal cancer patients with family history / 南方医科大学学报

<p><b>OBJECTIVE</b>To characterize the profile of chromosomal imbalances in esophageal cancer (EC) with or without family history in Linzhou, Henan Province of China.</p><p><b>METHODS</b>Comparative genomic hybridization (CGH) was used to examine 13 cases with positive family history of EC and 32 cases with negative family history of EC. RESULTS DNA copy number gains on chromosome 10q was observed only in the cases with postivie family history of EC (30%), and none in cases with a negative family history (P<0.05). DNA copy number losses on chromosome 15q were significantly higher in cases with postivie family history (38% vs 6%, P<0.05). The frequency of DNA copy number gains in 3q, 5p, 7p, 8q and DNA copy number losses in 3p, 19q, 9q were similar in the two groups (both beyond 20%) (P>0.05).</p><p><b>CONCLUSIONS</b>Frequent DNA copy number gains on chromosome 10q and losses on chromosome 15q in EC casers with postivie family history indicate that these chromosome sites may harbor the genes related to high susceptibility to EC. Such chromosomal sites as 3q, 5p, 7p, 8q, 3p, 19q, and 9q may contain important genes related with the environmental risk factors of esophageal carcinogenesis.</p>