Objective : To investigate the protective effect of dimethyl fumarate(DMF) on maternal intrahepatic cholestasis(ICP) during pregnancy induced by di(2-ethylhexyl) phthalate(DEHP) exposure and its mechanism. Methods : Thirty-two 8-week-old female institute of cancer research(ICR) mice were randomly divided into 4 groups: Ctrl group, DEHP group, DMF group and DEHP+DMF group. DEHP and DEHP+DMF groups were treated with DEHP(200 mg/kg) by gavage every morning at 9:00 a.m. DMF and DEHP+DMF groups were treated with DMF(150 mg/kg) from day 13 to day 16 of gestation by gavage. After completion of gavage on day 16 of pregnancy, maternal blood, maternal liver, placenta, and amniotic fluid were collected from pregnant mice after a six-hour abrosia. The body weight of the mother rats and the body weight of the fetus rats were sorted and analyzed; the levels of total bile acid(TBA), alkaline phosphatase(ALP), aspartate aminotransferase/alanine aminotransferase(AST/ALT) in serum and TBA in liver, amniotic fluid and placenta were detected by biochemical analyzer; HE staining was used to observe the pathological changes of liver tissue; Quantitative reverse transcription PCR(RT-qPCR) was used to detect the expression levels of tumor necrosis factor-α(TNF-α), interleukin(IL)-6, IL-1, IL-18 and NOD-like receptor thermal protein domain associated protein 3(NLRP3) in the liver; Western blot was used to detect the expression of the nuclear factor KappaB(NF-κB) and NLRP3. Results : Compared with the control group, the body weight of the DEHP-treated dams and pups decreased(P<0.05); the levels of TBA, ALP, AST/ALT in the serum of dams and the levels of TBA in the liver, amniotic fluid, and placenta of dams increased(P<0.05); the histopathological results showed that liver tissue was damaged, bile ducts were deformed, and there was inflammatory cell infiltration around them; the levels of inflammation-related factors TNF-α, IL-6, IL-1, IL-18 and NLRP3 transcription in maternal liver increased(P<0.05); the expression of NF-κB and NLRP3 protein in maternal liver significantly increased( P<0. 05). Compared with the DEHP group,the body weight of both dams and fetuses significantly increased in DEHP + DMF group( P<0. 05); the levels of TBA,ALP,AST/ALT in the serum of dams and amniotic fluid of fetuses decreased( P<0. 05); the degree of liver lesions was improved; the transcription levels of inflammation-related factors TNF-α,IL-6,IL-1,IL-18 and NLRP3 in maternal liver decreased( P<0. 05); the expression of NF-κB and NLRP3 protein in maternal liver significantly decreased( P<0. 05). Conclusion DMF can effectively protect the DEHP exposure to lead to female ICP,and its mechanism may be through inhibiting the NF-κB/NLRP3 pathway and reducing liver inflammation.

Objective : To establish a method for measuring major organic acids in the tricarboxylic acid cycle using a high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) system, and to investigate the changes in six tricarboxylic acid cycle organic acids(fumaric acid, malic acid, succinic acid, α-ketoglutaric acid, cis-aconitic acid, and citric acid) in the serum, liver, and placenta of mice exposed to di(2-ethylhexyl) phthalate(DEHP) during pregnancy. Methods : The serum, liver and placental samples from pregnant mice were processed and eluted through a Waters ACQUITY UPLC BEH Amide Column(130 Å, 1.7 μm, 2.1 mm × 150 mm) using a gradient elution program. Mobile phase A comprised an aqueous solution of 10 mmol/L ammonium acetate and 5 μmol/L methanephosphonic acid, while mobile phase B consisted of a 90% acetonitrile aqueous solution containing 10 mmol/L ammonium acetate and 5 μmol/L methanephosphonic acid, with a flow rate maintained at 0.35 ml/min. The mass spectrometry detection system utilized an electrospray ionization technique with negative ion mode for multiple reaction monitoring. Results : The correlation coefficients of the standard curves for the six tricarboxylic acid cycle organic acid metabolites were all above 0.996 within the quantitative range. The method's accuracy ranged from 97.14% to 108.26%, with inter-day and intra-day precision relative standard deviation between 1.35% and 6.73%. The matrix effect was between 93.29% and 107.47%, and the extraction recovery rate ranged from 94.82% to 112.57%. Analysis of six tricarboxylic acid cycle organic acids in the liver, serum, and placenta of DEHP-exposed mice during pregnancy showed significant reductions in fumaric acid, malic acid, α-ketoglutaric acid, cis-aconitic acid, and citric acid compared to the control group(P<0.05). Conclusion The HPLC-MS/MS method established in this study for detecting six tricarboxylic acid cycle organic acids in the serum, liver, and placenta of DEHP-exposed pregnant mice is stable, highly sensitive and selective. Prenatal DEHP exposure induced alterations in the levels of tricarboxylic acid(TCA) cycle organic acid metabolites in the liver, serum, and placenta of mice, suggesting that DEHP exposure during pregnancy may interfere with mitochondrial TCA cycle processes. These findings indicate potential value in the diagnosis and treatment of diseases associated with prenatal DEHP exposure.

ObjectiveTo establish a polymerase chain reaction（PCR） method to accurately discriminate the crude materials of Murrayae Folium et Cacumen， Murraya exotica and M. paniculata. MethodBased on the difference in chloroplast genome sequences of M. exotica and M. paniculata， species-specific identification primers P03 and P04 of M. exotica and M. paniculata were designed according to single nucleotide polymorphism （SNP） on the chloroplast genome. A multiplex allele-specific PCR identification method was established for the identification of M. exotica and M. paniculata following the optimization of annealing temperature， number of cycles， and primer concentration ratio. The established PCR method for identification was explored and verified in terms of tolerance and feasibility by investigating the type of Taq polymerases and PCR system model. ResultIn this multiplex allele-specific PCR identification method， about 330 and 230 bp of specific fragments were amplified from DNA templates of M. exotica and M. paniculata， respectively， under the following conditions：cycle number of 31， annealing temperature of 60 ℃， and primer concentration ratio of P03 and P04 of 1∶2. Consistent results were obtained for samples from different sources. ConclusionThe multiplex allele-specific PCR identification method established in this study can accurately identify the origin of Murrayae Folium et Cacumen， which can be used for the simultaneous identification of M. exotica and M. paniculata by the length of fragments in a single identification assay.

Dissolving pulp consists of high purity cellulose and is widely used to as raw materials for the production of regenerated cellulose fiber, cellulose ester and cellulose ether. The characteristic of dissolving pulp affects greatly the production and processing performance of subsequent products. The α-cellulose content, hemicellulose content, pulp viscosity, ash, transition metal ion content, fiber morphology, molecular weight distribution of cellulose and the reactivity are the important properties. Because of its green, mild and high efficiency, the application of enzymes in improving the properties of dissolving pulp has a promising application prospect and has been researched significantly. In this review, the main properties of dissolving pulp are presented first, followed by a recommendation of the enzymes to improve these properties. The application and current research of cellulase and xylanase in improving the properties of dissolving pulp are emphasized. The main problems and the future research areas in improving the properties of dissolving pulp by enzymes are revealed. Finally, the technology prospects in this field are proposed.
Cellulase ; Molecular Weight ; Viscosity ; Wood

Objective To explore the possible role and mechanism of the Kupffer cells (KCs) in liver allo-geneic transplantation at the early stage. Methods In vitro cell contact coculture system was established. Culture supernatants were collected respectively on the 1st, 2nd, 4th, 6th d after cocul-ture and the KCs and PBMCs were harvested on the 6th day after culture. The expression of HLA-G on the membrane of the KCs and PBMCs was detected with immunochemistry. Nitrate reduction test was used to determine the concentration of nitric oxide. IFN-γ, IL-10, TGF-β1 cytokine levels in the supernatants were also measured with ELISA. The proliferation of lymphocytes was evaluated with MTT. Results six days later, no HLA-G molecules were detected on the membrane of the KCs and PBMCs. In the experimental group containing KCs, the levels of NO, IL-10 and TGF-β1 was signifi-cantly increased(P<0. 05), while the levels of IFN-γ was relatively lower(P<0. 05) as compared to the experimental group without KCs. No IL-10 and IFN-γ were detected in the control group, and on-ly few NO and TGF-β1 was found in the control group with KCs. MTT test showed that the value of optical density was lower in the experimental group with KCs than that in any other group(P<0. 05).Conclusion No HLA-G is expressed on the membrane of KCs and PBMCs after contact coculture.KCs may participate in regulating production of NO and Th2/Th3-like cytokines and suppressing the proliferation of lymphocytes, through which KCs probably take part in inducing immunotolerance of liver transplantation in early stage.

Objective To investigate the clinical outcome of tibiotalocalcaneal arthrodesis plus retrograde intramedullary nail in treatment of severe posttraumatic tibiotalar and talocalcaneal arthritis.Methods A total of 17 cases of severe posttraumatic tibiotalar and subtalar arthritis were treated with tibiotalocalcaneal arthrodesis plus retrograde intramedullary nail between June 2003 and June 2006.Patients were evaluated by a standardized follow-up examination using ankle-hindfoot scale of the American Orthopedic Foot & Ankle Society(OFAS)score. Results Of all,14 cases were followed up postoperatively,with a mean follow-up period of 14.6 months(6-23 months).Bony fusion was achieved in 12 cases (86%)after an average of 11.6 weeks(8-19 weeks)but a delayed union in 2 after 17-19 weeks.Two cases(12%)complained heel pain at the nail entry point at initial stage of operation.The average anklehindfoot score improved from 47 points(43-55 points)preoperatively to 75 points(69-86 points)postoperatively. Conclusion Tibiotalocalcancal arthrodesis plus retrograde intramedullary nailing is proved to be effective in treating severe posttraumatic tibiotalar and talocalcaneal arthritis by marked relief from pain and improvement of life quality.