Extracellular Polysaccharides Matrix—An Often Forgotten Virulence Factor in Oral Biofilm Research

Oral diseases related to dental biofilms continue to afflict the majority of the world＇s population. Among them, dental caries continues to be the single most prevalent and costly oral infectious disease （Marsh, 2003; Dye et al., 2007）. Dental caries results from the interaction of specific bacteria with constituents of the diet within a dental biofilm known as plaque （Bowen, 2002）. Sucrose is considered to be the ＂arch criminal＂ from the dietary aspect because it serves as a substrate for synthesis of extracellular （EPS） and intracellular （IPS） polysaccharides in dental biofilm and is also fermentable （Bowen, 2002）.

Research and perspectives on criteria for evaluation of nursing research achievements

This paper introduces concepts related to scientific research achievements, analyzes current evaluation methods with regard to nursing research achievements and their application at home and abroad, and summarizes findings from the investigation of obstacles to the application of nursing research results in China, aiming to provide reference points for the evaluation and application of nursing research results in China.

Effect of Ligustrazine Nanoparticles Nano Spray on Transforming Growth Factor-β/Smad Signal Pathway of Rat Peritoneal Mesothelial Cells Induced by Tumor Necrosis Factor-α

Objective： To study the effect of ligustrazine nanoparticles nano spray（LNNS） on transforming growth factor β（TGF-β）/Smad signal protein of rat peritoneal mesothelial cells（RPMC） induced by tumor necrosis factor α（TNF-α）, and the anti-adhesion mechanism of LNNS in the abdominal cavity. Methods： The primary culture and subculture of rat peritoneal mesothelial cells（RPMC） was processed by trypsin digestion method in vitro. The third generation was identified for experiment and divided into 5 groups： a blank group： RPMC without treatment; a control group： RPMC stimulated with TNF-α; RPMC treated by a low-dosage LNNS group（2.5 mg/L）; RPMC treated by a medium-dosage LNNS group（5 mg/L）; and RPMC treated by a high-dosage LNNS group（10 mg/L）. Reverse transcription-polymerase chain reaction was applied to test the expression of fibronectin, collagen Ⅰ（COL-Ⅰ）, TGF-β m RNA, and Western blot method to test the Smad protein 7 expression of RPMC. Results： Compared with the blank group, a significant elevation in fibronectin（FN）, COL-Ⅰ and TGF-β m RNA expression of RPMC were observed in the control group（P〈0.05）. Compared with the control group, LNNS suppressed the expressions of FN, COL-Ⅰ and TGF-β m RNA in a concentrationdependent manner（P〈0.05）. The expression of Smad7 protein of RPMC was down-regulated by TNF-α stimulation, and up-regulated with the increase of LNNS dose（P〈0.05）. Conclusions： TNF-α may induce changes in RPMC＇s viability, leading to peritoneal injury. LNNS could reverse the induction of fibrosis related cytokine FN, COL-Ⅰ and TGF-β, up-regulating the expression of Smad7 by TNF-α in RPMC, thus attenuate peritoneal injury by repairing mesothelial cells.