Objective: To develop a headspace gas chromatography ( HS-GC ) assay for simultaneous determination of dichloroacetic acid ( DCA ) and trichloroacetic acid ( TCA ) in urine. Methods: Urine samples (5 mL) were transferred to a 22 mL headspace bottle, added with 0.5 mL 10% sodium acetate solution , immediately sealed, and shaken evenly. The bottle was placed in the HS-GC system, and equilibrated at 90 ℃ for 60 minutes. The mixture was separated with the HP-INNOWAX chromatographic column, and the DCA and TCA concentrations were detected with the hydrogen flame detector. Results: Under the optimal experimental conditions, the correlation coefficient of DCA and TAC was both > 0.999 0 within the range of 10-500.0 μg/L, and the lowest detection limits of DCA and TAC were 2.0 and 3.5 μg/L, with the spike recovery rate of 87.40% to 101.44%, and relative standard deviations of 1.89% to 3.25%. Of the 35 urine samples sampled from occupational populations, DCA and TCA were not detected. Conclusions The establishment of the HS-GAS assay through addition of sodium acetate and optimization of the headspace conditions, has high recovery and precision, which is effective to meet the requirements for daily determination of DCA and TCA in urine samples.

Objective· To compare the impacts on clinical efficiency and safety between 0.014 inch Synchro microwire and Transend microwire used during mechanical thrombectomy for acute ischemic stroke (AIS) caused by large artery occlusion.Methods· Forty-six patients undergoing mechanical thrombectomy with stent retrievers between October 2012 and January 2016 were included,who were classified into Synchro group (21cases) and Transend group (25 cases).The clinical outcome,procedure time,and safety were analyzed and compared between two groups.Results· The recanalization rates were similar between two groups (P=0.600),but time from puncture to vascular recanalization of Synchro group was much shorter than that of Transend goup (48.88 min vs 82.33 min,P=0.001).The rates of functional independence (modified Rankin scale score ≤ 2) were similar between two groups (P=1.000).There was no significant difference of the rates of post-procedure subarachnoid hemorrhage (PSAH) between two groups (P=1.000).However,there were two cases that had fatal subarachnoid hemorrhage with intracranial hematoma in Transend group,while there was only one case of mild subarachnoid hemorrhage who recovered well in Synchro group.Conclusion· Compared with Transend microwire,Synchro microwire can significantly shorten the procedure time of mechanical thrombectomy,and the risk of fatal subarachnoid hemorrhage is rather small.

Objective:To explore the associations of MYH9 gene polymorphisms with ESRD in Han population in the fragment between exon 23 and 24.Methods:A hospital-based case control study was carried out including 180 patients and 118 controls in this study.Single nucleotide polymorphisms of MYH9 gene were determined using PCR sequencing,and the haplotypes were calculated using phase software(version 2.0),and transcription factor binding sites were predicted using AliBaba2.Univariate analysis was conducted for exploring the associations between polymorphisms and ESRD.Results: Five newly discovered and three previously reported SNP loci [Rs4821480(MYH9-92),Rs2032487(MYH9-273) and Rs4821481(MYH9-787)]were homozygote genotyped by bidirectional se-quencing.Among newly discovered polymorphisms,two were found at the 489 locus(G→A)and the 616 locus(A→C) in the 901 bp fragment which located in the intron 23 of MYH9 gene.A G489A transversion was very likely a risk mutation contribute to the occurrence of ESRD(P=0.013).No association was observed between ESRD and three previous reported sites [Rs4821480(MYH9-92),Rs2032487(MYH9-273)and Rs4821481(MYH9-787)].The most common haplotype was TCTCGGAT,which was less frequent in the cases than that in the controls.Moreover, TCTCGGCT and TCTCAGAT haplotypes were more in the cases than that in the controls.The number of transcription binding sites increased from 82 ( wild ) to 85 ( mutation ) in the 23th intron of MYH9 gene.Conclusion:Polymorphisms of MYH9 at intron 23 may influence the prevalence of ESRD in Chinese Han population and TCTCGGAT haplotype may be one protective haplotype.TCTCGGCT and TCTCAGAT may be risk haplotypes attributed to ESRD.The polymorphism of MYH9 at the 23th intron may company with the amount alteration of transcription factor binding sites.

Objective:To study the biological behavior of nasopharyngeal carcinoma stem cells and to explore the activation of Ras signaling pathway regulated by CD44.Methods:CNE2-SC and 5-8F-SC were nasopharyngeal carcinoma stem cells and obtained by serum-free suspension culture. Cell counting kit-8 (CCK-8) assay, colony formation assay, Transwell migration assay, cell adhesion array were used to investigate the growth, proliferation, migration and adhesion of nasopharyngeal carcinoma stem cells. Western blot test was used to detect the expressions of Ras signaling pathway related proteins and siRNA-mediated interference was used to determine the activation of Ras signaling pathway regulated by CD44.Results:The growth rates of CNE2-SC and 5-8F-SC cells were significantly lower than those of nasopharyngeal carcinoma cells at 24, 48 and 72 hours after inoculation ( P<0.05). After 14 days of implantation, the colony formation rates of CNE2-SC (44.5±1.9)% and 5-8F-SC (47.4±1.8)% were higher than those of CNE2 (34.9±1.5)% and 5-8F (37.2±1.7)%, respectively( P<0.01). The migration cell number of CNE2-SC was (87.6±7.8), 3.97 times higher than that of CNE2 ( P<0.01). The migration cell number of 5-8F-SC was (67.2±5.7), 3.07 times higher than 5-8F ( P<0.01). The adhesion rates of CNE2-SC and CNE2 cells were (42.1±7.6)% and (8.9±2.0)%, respectively at 3 hours after inoculation and were (82.4±5.0)% and (12.1±2.2)% at 6 hours after inoculation, respectively. The adhesion rate of CNE2-SC cells was higher than that of CNE2 cells (all P<0.01). The adhesion rates of 5-8F-SC and 5-8F cells were (53.6±6.1)% and (7.3±1.5)% at 3 hours after inoculation, and (90.7±3.6)% and (11.0±1.2)% at 6 hours after inoculation, respectively. The adhesion rate of 5-8F-SC cells was higher than that of 5-8F cells ( P<0.01). The expression levels of CD44, Ras and N-cadherin were significantly higher, while phosphatase and tensin homolog deleted on chromosome 10 (PTEN), E-cadherin in nasopharyngeal carcinoma stem cells were lower than those of the nasopharyngeal carcinoma cells. Furthermore, the levels of phosphorylated mitogen extracellular kinase1/2 (p-MEK1/2) and phosphorylated extracellular signal-regulated protein kinase1/2 (p-ERK1/2)were significantly increased in nasopharyngeal carcinoma stem cells ( P<0.01). Correlation analysis showed that the protein expression levels of CD44 was highly positively correlated with RAS in nasopharyngeal carcinoma stem cells( r=0.985, P=0.002; r=0.962, P=0.038). Deletion of CD44 in CNE2-SC decreased the expression levels of HER-2, Ras and p-ERK1/2, p-Akt and phosphorylated protein kinase C-δ(p-PKCδ) ( P<0.01). Conclusions:Despite compare to the nasopharyngeal carcinoma cell, nasopharyngeal carcinoma stem cells grows at a relatively slow rate, the capacities of clone formation, migration, adhesion are promoted. This may be related to the CD44-regulated abnormal activation of Ras signaling pathway.

Objective:To study the biological behavior of nasopharyngeal carcinoma stem cells and to explore the activation of Ras signaling pathway regulated by CD44.Methods:CNE2-SC and 5-8F-SC were nasopharyngeal carcinoma stem cells and obtained by serum-free suspension culture. Cell counting kit-8 (CCK-8) assay, colony formation assay, Transwell migration assay, cell adhesion array were used to investigate the growth, proliferation, migration and adhesion of nasopharyngeal carcinoma stem cells. Western blot test was used to detect the expressions of Ras signaling pathway related proteins and siRNA-mediated interference was used to determine the activation of Ras signaling pathway regulated by CD44.Results:The growth rates of CNE2-SC and 5-8F-SC cells were significantly lower than those of nasopharyngeal carcinoma cells at 24, 48 and 72 hours after inoculation ( P<0.05). After 14 days of implantation, the colony formation rates of CNE2-SC (44.5±1.9)% and 5-8F-SC (47.4±1.8)% were higher than those of CNE2 (34.9±1.5)% and 5-8F (37.2±1.7)%, respectively( P<0.01). The migration cell number of CNE2-SC was (87.6±7.8), 3.97 times higher than that of CNE2 ( P<0.01). The migration cell number of 5-8F-SC was (67.2±5.7), 3.07 times higher than 5-8F ( P<0.01). The adhesion rates of CNE2-SC and CNE2 cells were (42.1±7.6)% and (8.9±2.0)%, respectively at 3 hours after inoculation and were (82.4±5.0)% and (12.1±2.2)% at 6 hours after inoculation, respectively. The adhesion rate of CNE2-SC cells was higher than that of CNE2 cells (all P<0.01). The adhesion rates of 5-8F-SC and 5-8F cells were (53.6±6.1)% and (7.3±1.5)% at 3 hours after inoculation, and (90.7±3.6)% and (11.0±1.2)% at 6 hours after inoculation, respectively. The adhesion rate of 5-8F-SC cells was higher than that of 5-8F cells ( P<0.01). The expression levels of CD44, Ras and N-cadherin were significantly higher, while phosphatase and tensin homolog deleted on chromosome 10 (PTEN), E-cadherin in nasopharyngeal carcinoma stem cells were lower than those of the nasopharyngeal carcinoma cells. Furthermore, the levels of phosphorylated mitogen extracellular kinase1/2 (p-MEK1/2) and phosphorylated extracellular signal-regulated protein kinase1/2 (p-ERK1/2)were significantly increased in nasopharyngeal carcinoma stem cells ( P<0.01). Correlation analysis showed that the protein expression levels of CD44 was highly positively correlated with RAS in nasopharyngeal carcinoma stem cells( r=0.985, P=0.002; r=0.962, P=0.038). Deletion of CD44 in CNE2-SC decreased the expression levels of HER-2, Ras and p-ERK1/2, p-Akt and phosphorylated protein kinase C-δ(p-PKCδ) ( P<0.01). Conclusions:Despite compare to the nasopharyngeal carcinoma cell, nasopharyngeal carcinoma stem cells grows at a relatively slow rate, the capacities of clone formation, migration, adhesion are promoted. This may be related to the CD44-regulated abnormal activation of Ras signaling pathway.