[Construction of human telomerase reverse transcriptase periodontal ligament cell line mediated by adenovirus].

OBJECTIVE: This study aims to establish an effective and stable periodontal ligament cell line stably expressing human telomerase reverse transcriptase (hTERT) gene by using the adenovirus method. METHODS: Polymerase chain reaction (PCR) was used to amplify the full length of hTERT gene to construct recombinant adenovirus plasmid pAd-pshuttle-cmv-hTERT. Packaged adenovirus particles were used for infection of human periodontal ligament cells. The expression levels of hTERT and osteogenic genes, such as alkaline phosphatase, Runt-related transcription factor 2, bone sialoprotein, osteocalcin, osteopontin, and collagen Ⅰ mRNA, were detected by quantitative real-time PCR (qRT-PCR). The ability of osteogenic differentiation was observed by alizarin red staining, and the cell proliferation was determined by CCK-8. RESULTS: Adenovirus particles containing the hTERT gene were successfully constructed and infected with periodontal ligament cells. The infected cells were similar to normal periodontal ligament cells. The qRT-PCR results showed that hTERT and osteogenesis-associated genes were highly expressed in the periodontal ligament cell lines constructed by adenoviruses. Alizarin red staining showed that the periodontal ligament cell line had strong osteogenic differentiation capability. CCK-8 showed that the periodontal ligament cell line had strong proliferation capability. CONCLUSIONS: The human periodontal ligament cell line with high efficiency and stable expression of hTERT was established by the adenovirus method, thereby providing an ideal cell line for studying the mechanism of periodontal regeneration.

A Facile Green Synthesis of Silver Nanoparticles Based on Poly-L-Lysine.

In this paper, we report a novel synthesis method for silver nanoparticles with facilely controllable morphology under mild conditions. The particles were synthesized by reducing silver nitrate in the presence of water soluble polymer of poly-L-Lysine (PLL) which was used as reducing agent and stabilizer. Experimental results revealed that size variation and overall formation mechanism of the resulting silver particles were mostly determined by the conformation of PLL which was in turn controlled by pH of solution and temperature. Due to biological activity and response ability of PLL to outer stimuli, the method provides a facile and controllable method for producing silver particles with different morphologies. We believe that the synthesis method will contribute to applications of the PLL and silver particles in biomaterials.

[Epidemiological investigation of imported falciparum malaria in Longlin County, Guangxi Zhuang Autonomous Region].

Among 41 people returned from Equatorial Guinea, 16 persons were infected with Plasmodium falciparum (39.02%) in Longlin County, Guangxi Zhuang Autonomous Region from October 2011 to February 2012. Among the 16 cases, Plasmodiumfalciparum was found in their blood smears of 15 cases, and 1 patient was diagnosed clinically as falciparum malaria. All the 41 people were once suffered from malaria and they received antimalarial drugs when they were in Equatorial Guinea. These imported malaria cases received the standard treatment and the foci were sprayed with insecticides. No secondary malaria cases were found. In conclusion, the measures of imported malaria control are effective. The persons returned from Equatorial Guinea have a high risk of malaria; therefore, it is necessary to strengthen the monitoring of malaria for the floating population from high malaria prevalent areas.