OBJECTIVE To establish an in vitro blood-cerebrospinal fluid barrier (BCB) model to investigate the underlying mechanism of lead-induced BCB injuries.METHODS The in vitro BCB model was established by Z310 cells.Different concentrations of Pb(AC)2 (2.5,5.0 and 10.0 mmol·L-1) were used for 24,48 and 72 h.Transendothelial electrical resistance (TEER) and flux of FITC-dextran were performed to determine the permeability of the in vitro BCB model.Western blotting and immunofluorescence methods were used to observe the expression of tight junction protein ZO-1 and occludin.RESULTS Compared with control group,Pb(AC)2 2.5,5.0 and 10.0 mmol· L-1 exposure for 48 h to Z310 cells had no significant effect on survival rate and density.TEER in different groups was gradually increasing.At the 12th day after Pb(AC)2 exposure,the values of TEER and flux of FITC-dextran in Pb(AC)2 5 and 10 mmol· L-1 groups were significantly decreased (P＜0.05).Western blotting and immunofluorescence images showed that the expression of ZO-1 and occludin were significantly decreased (P＜0.05) after Pb(AC)2 exposure for 48 h.CONCLUSION Lead exposure can cause the breakdown of BCB barriers,and this effect may be mediated by reducing the expression of ZO-1 and occludin proteins.

Objective:To evaluate the effects of Sander Ⅱ appliance in the orthodontic treatment of adolescent ClassⅡmalocclusion. Methods:15 cases (6 male and 9 female)of adolescent ClassⅡ malocclusion with mandibular retrution were treated with Sander Ⅱappliance.Pre-treatment and post-treatment Lateral cephalogram measurements were traced and analyzed in terms of 28 indicators. SPSS 19.0 software package was used for paired t test.Results:After treatment,15 patients achieved remarkable improvement in the maxillofacial profile and normal overjet of teeth.The cephalometric analysis showed that ANB,OJ,H°and U1-E decreased(P <0. 05),SNB,B-OLP,Pg-OLP(mm),Ii-OLP,Ms-OLP(mm),Mi-OLP(mm),N-Me,ANS-Me,S-Go,Go-Gn,N'-Pg'/FH,Cm-Sn-Ls and Pg-Pg'increased(P <0.05).There was no significant change in SN-MP,SN-OL and Y-axis before and after treatment. Conclusion:Sander Ⅱ appliance is effective in the treatment of adolescent early Class Ⅱmalocclusion.

OBJECTIVETo understand the transmission mode of human infection with avian influenza A (H7N9) virus.

METHODSField epidemiological investigation was conducted for a family clustering of human infection with H7N9 virus in Hengxian county, Guangxi Zhuang Autonomous Region in February 2014. Two patients and their 82 close contacts were surveyed. The samples collected from the patients, environments and poultry were tested by using real time reverse transcriptase-polymerase chain reaction (rRT-PCR), and the samples from patients were used for virus isolation. The samples from 5 close contacts were tested with RT-PCR. The clinical data, exposure histories of the patients and the detection results of the isolates and their homology were analyzed.

RESULTSPatient A became ill 4 days after her last exposure to poultry in Zhongshan, Guangdong province, and returned to her hometown in Hengxian 2 days after onset. Patient B was patient A's 5 years old son, who had no known exposure to poultry but slept with patient A for 4 days. He developed symptoms 4 days after last contact with his mother. Two strains of H7N9 virus were isolated from the two patients. The 2 isolates were highly homogenous (almost 100%) indicated by gene sequencing and phylogenetic tree. None of the other 81 close contacts developed symptoms of H7N9 virus infection.

CONCLUSIONPatients B was infected through close contact with patient A, indicating that avian H7N9 virus can spread from person to person, but the transmissibility is limited and non-sustainable.

Animals ; Child, Preschool ; China ; Cluster Analysis ; Contact Tracing ; Family ; Female ; Homozygote ; Humans ; Influenza A Virus, H7N9 Subtype ; genetics ; isolation & purification ; Influenza, Human ; transmission ; virology ; Male ; Phylogeny ; Poultry ; virology ; Real-Time Polymerase Chain Reaction ; Sleep