Diagonal root separation method for extracting impacted double-root mandibular third molars / 华西口腔医学杂志

Double-root mandibular third molars are the common types of mandibular third molars that are prone to impac-tion. Based on the summary of clinical cases and experience, the commonly used crown-root separation technique is improved as diagonal root separation technique that divides the roots by the line connecting the distal axis angle to the root furcation. This new method improves the efficiency of the operation and reduces surgical trauma. This paper details the surgical method, minimally invasive mechanics, and key points of this technique, compares the technique with the crown-root separation tech-nique, and discusses their joint applications.

The effect of DNA methyltransferase 1 low expression on the global genome DNA methylation status of 16HBE cell / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To construct DNA methyltransferase 1 (DNMT1) low expression 16HBE cell line and observe the variation of cell cycle and global genomic DNA methylation.</p><p><b>METHODS</b>The method of Lenti-virus induced RNA interference was applied to introduce four different shRNA fragment into 16HBE cells. Flow cytometry and 5-mC immunofluorescence methods were used to observe the cell cycle and global DNA methylation status of DNMT1 low expression 16HBE cells.</p><p><b>RESULTS</b>The DNMT1 protein relative expression level of 16HBE-shDNMT1-4 cell line was down regulated about 44% (P < 0.05) compared with the control. No obvious differences of cell cycle and global genome DNA methylation status were observed between the 16HBE and 16HBE-shDNMT1.</p><p><b>CONCLUSION</b>The DNMT1 gene low expression cell is successfully constructed, and there are no obvious changes happened on the cell cycle and global genomic DNA methylation.</p>

Effects of pretreatment with small dose of lipopolysaccharide on cardiac function in endotoxemic rats / 中华麻醉学杂志

Objective It was reported that pretreatment with small dose of lipopolysaccharide (LPS) could protect the animal from lethal dose endotoxin. The purpose of this study was to investigate the effects of pretreatment with small dose of LPS on cardiac function in endotoxemic rats and the possible mechanism. Methods Sixty male Wistar rats weighing 200-280 g were randomly divided into 3 groups: group I normal saline(NS) ( n = 12); group Ⅱ LPS (n = 24) and group Ⅲ LPS-pretreatment ( n = 24). Group Ⅱ and group Ⅲ were further divided into 3 groups: 2 h,4 h and 6 h subgroups based the time when blood sample was taken and the animal was sacrificed. The table shows the LPS given in the 3 groups:groupⅠⅡ Ⅲ0hNSNSLPS 0.25 mg?kg-1ip24 hNSNSLPS0.5mg?kg-1ip96 hNSLPS 10 mg?kg-1 Ⅳ LPS 10 mg?kg-1 TVThe animals were anesthetized with 3 % pentobarbital 30 mg?kg ip and intubated. Right femoral artery and vein were cannulated for MAP monitoring and fluid infusion. Cardiac catheter was placed in the left ventricle for measurement of left ventricular systolic pressure (LVSP) and?dp/dt max. Blood samples were taken 2 h,4 h and 6 h after intravenous LPS (10 mg?kg-1) for determination of plasma levels of L-lactate-dehydrogenase (LDH) and creatine kinase (CK) . The animals were sacrificed right after blood sampling and the heart was removed for determination of myocardial HSP 70 expression using immuno-histochemical staining. Results LVSP and?dp/dt max gradually decreased 1h after intravenous administration of LPS in group Ⅱ (LPS group); while in group DI (pretreatment group) the cardiac contractility was maintained and LVSP,?dp/dt max did not decrease as compared with the baseline value. Plasma LDH concentration and CK activity increased significantly 4 h and 6 h after intravenous IPS in group Ⅱ . The plasma LDH and CK levels were significantly lower in groupⅢthan those in group Ⅱ ( P