A new method was proposed for analysis of the organic compounds in cigarette smoke by high resolution Orbitrap mass spectrometry based on polyacrylonitrile-silica (PAN-SiO2) nanofiber membrane extraction and methanol elution.Hydrophobic PAN-SiO2 nanofiber membrane which was used to enrich small molecular organic compounds in cigarette smoke was prepared by the technology of electrospinning.Several parameters including the concentrations of PAN and SiO2 nanopartical,elecrospining voltage,needle aperture and flow rate of spinning solution were optimized.Under the optimal conditions,a PAN-SiO2 nanofiber membrane with good adsorption performance and great physical strength was obtained.A total of 21 compounds including acetone,styrene,acrolein,isoprene,and acrylonitrile were identified by analyzing the cigarette smoke with Orbitrap MS spectrometry in the positive ion mode.Six organic acids including salicylic acid,malic acid and lactic acid were detected in negative ion mode.The limits of detection and quantification for nicotine were 0.071 ng/L and 0.236 ng/L,respectively.

Objective To investigate the mechanism of protective effects of 17-β estradiol on the experimental model of spinal cord injury (SCI) rats.Methods First,the primary astrocytes were cultured and identified.When the third generation astrocytes were cultured,they were induced by H202 whose concentrations were established by the method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT).The cells were randomly divided into five groups:control group; the group of treatment with 400 μmol/L H2O2 for 24 hours; the group of treatment with 20 nmol/L estrogen for 2 hours prior to exposure to 400 μmol/L H2O2 for 24 hours; the group of treatment with 20 nmol/L estrogen for 26 hours and the group of treatment with dimethyl sulfoxide for 26 hours.The proteins which were extracted from these cells after treatments with H2O2 for 24 hours were detected by Western blotting.Results The absorbances of the astrocytes of treatments with H2O2 were reduced( q' =-11.45,P =0.001 ).But exposure to estrogen prior to exposure to H2O2 provided partial restoration of the absorbances (q' =7.025,P =0.0025 ).The absorbances of the astrocytes among different groups showed significant differences( F =69.69,P =0.0025 ).The results suggested that estrogen might increase the cell viability in astrocytes.Compared with the group of treatment cells with H2O2,treatment cells with 17-β estradiol prior to H2O2 exposure down-regulated the expressions of both phosphatase and tensin homologue deleted on chromosome 10 ( PTEN ) ( F =290.003,P =0.001 ) and caspase-3 ( F =46.158,P =0.023 ).And,17-β estradiol treatment of cells increased the levels of p-Akt ( F =49.173,P =0.033 ) and Bcl-2 ( F =115.916,P =0.001 ) when compared with the group of treatment astrocytes with H2O2.Conclusion These findings suggest that the attenuation of PTEN expression mediated by estrogen is associated with an increase in phosphorylation/activation of the Akt and the Bel-2 expressions.These results suggest that the protective effects of 17-β estradiol on the experimental model of SCI rats may depend on the estrogen protection to the astrocytes which may be mediated by decreasing the PTEN expression.

OBJECTIVETo explore the correlation between F10 gene mutation and its phenotype in a Chinese pedigree affected with FX deficiency.

METHODSProthrombin time(PT), activated partial thromboplastin time(APTT), fibrinogen, FII activity(FII:C), FVII activity(FVII:C), FIX activity (FIX:C), FX activity(FX:C) were determined with a one-stage clotting assay. The FX antigen(FX:Ag) was detected with an enzyme linked immunosorbent assay(ELISA). The 8 exons, introns and 5' and 3' untranslated regions(UTR) of the F10 gene of the proband and her family members were subjected to PCR amplification and Sanger sequencing. Suspected mutation was confirmed by reverse sequencing. Polymorphisms were excluded by direct sequencing of 100 healthy individuals.

RESULTSThe PT and APTT of the proband have prolonged to 16.1 s and 49.0 s, respectively. Her FX:C and FX:Ag were reduced by 27% and 56%, and her mother's PT, APTT, FX:C and FX:Ag were 14.8 s, 37.4 s, 44%, 34%, respectively. Her grandmother's PT, APTT, FX:C and FX:Ag were 15.8 s, 42.2 s, 31%, 45%, respectively. The results of her father and other family members were all within the normal range. Genetic analysis has revealed a heterozygous G to A mutation in the proband at position 28076 in exon 8 of the F10 gene, which resulted in a p.Gly363Ser substitution. The same mutation was also found in her mother and grandmother. No mutation of the F10 gene was found in her father. Gly363Ser may result in changes in the secondary structure of the FX protein and reduction of its activity.

CONCLUSIONThe g.28076G to A(p.Gly363Ser) mutation of the F10 gene probably underlies the FX deficiency in this pedigree. The mutation was discovered for the first time in Chinese patients.

Objective: To evaluate the role of hippocampal mast cells in the early postoperative cognitive impairment in rats. Methods: Eighty male Sprague-Dawley rats, aged 6-8 weeks, weighing 200-250 g, were divided into 4 groups (n=20 each) using a random number table method: normal saline control group (group C), cromolyn injected into lateral cerebral ventricle group (group L), operation group (group O), and cromolyn injected into lateral cerebral ventricle plus operation group (group LO). Cromolyn 2 μl (100 μg/ul) was intracerebroventricularly injected in L and LO groups.The equal volume of normal saline was given instead in C and O groups.Open reduction and internal fixation was performed after tibial fracture was induced 30 min later in O and LO groups.Contextual fear conditioning and Y-maze tests were performed at 1 and 3 days after operation, and the freezing time and the number of learning trails were recorded.The animals were then sacrificed, and hippocampal tissues were obtained for determination of activated mast cell count (by toluidine blue staining) and expression of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) mRNA (by polymerase chain reaction). Results: Compared with group C, the number of learning trails was significantly increased, and the freezing time was shortened, the number of activated mast cells in hippocampi was increased, and the expression of IL-1β mRNA was up-regulated at 1 and 3 days after operation, and the expression of TNF-α mRNA was up-regulated at 1 day after operation in group O(P<0.05), and no significant change was found in the parameters mentioned above in group L (P>0.05). Compared with group O, the number of learning trails was significantly decreased, and the freezing time was prolonged, the number of activated mast cells in hippocampi was decreased, and the expression of IL-1β mRNA in hippocampi was down-regulated at 1 and 3 days after operation, and the expression of TNF-α mRNA in hippocampi was down-regulated at 1 day after operation in group LO (P<0.05). Conclusion Activation of hippocampal mast cells can induce central inflammatory responses and is involved in the mechanism of early postoperative cognitive impairment in rats.