OBJECTIVEThe study was aimed to investigate the inhibitory effect and mechanism of astragaloside IV (ASI) on the activation of microglial cells.

METHODAfter pre-incubated with ASI for 2 h, microglial cells BV-2 were stimulated with interferon-γ (IFN-γ) for 1. 5 h and 24 h, respectively. Secretion of nitric oxide (NO) in the medium was measured by Griess method. Production of tumor necrosis factor alpha (TNF-α) was detected by ELISA approach. Cellular gene expressions of CD11b, TNF-α, interleukin 1β (IL-1β) and induced nitric oxide synthase (iNOS) were examined by quantitative-PCR analysis. Total and phosphorylation of STAT1, IκB and NF-κB was analyzed by Western blot method.

RESULTASI could significantly inhibit the increased secretion of TNF-α and NO from BV-2 cells upon IFN-γ stimulation (P < 0.001). Further study showed that ASI significantly down-regulated gene expression of IL-1β and TNF-α (P < 0.01, P < 0.05) and exhibited a trend to reduce that of iNOS. IFN-γ and ASI have no obvious effect on gene expression of CD11b. Moreover, ASI inhibited the phosphorylation of STAT1, IκB and NF-κB elicited by IFN-γ stimulation.

CONCLUSIONASI could restrain microglial activation through interfering STAT1/IκB/NF-κB signaling pathway, reducing gene expres- sion of IL-1β and TNF-α, and thus inhibiting the production of proinflammatory mediators such as NO and TNF-α.

Animals ; Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; I-kappa B Proteins ; genetics ; metabolism ; Interferon-gamma ; genetics ; metabolism ; Mice ; NF-kappa B ; genetics ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; STAT1 Transcription Factor ; genetics ; metabolism ; Saponins ; pharmacology ; Signal Transduction ; drug effects ; Triterpenes ; pharmacology

Dust ; analysis ; Humans ; Magnoliopsida ; Pneumoconiosis ; epidemiology ; Prevalence

Selectable marker genes that usually encode antibiotic or herbicide resistances are widely used for the selection of the transgenic plants, but they become unnecessary and undesirable after transformation selection. An important strategy to improve the transgenic plants' biosafety is to eliminate the marker genes after successful selection. In the FLP/frt site-specific system of the 2 microm plasmid of Saccharomyces cerevisiae, the FLP enzyme efficiently catalyzes recombination between two directly repeated FLP recombination target (frt) sites, eliminating the sequence between them. By controlled expression of the FLP recombinase and specific allocation of the frt sites within transgenic constructs, the system can be applied to eliminate the marker genes after selection. Through a series of procedures, the plant FLP/frt site-specific recombination system was constructed, which included the frt containing vector pCAMBIA1300-betA-frt-als-frt and the FLP expression vector pCAMBIA1300-hsp-FLP-hpt. The FLP recombinase gene was introduced into transgenic (betA-frt-als-frt) tobacco plants by re-transformation. In re-transgenic plants, after heat shock treatment, the marker gene als flanked by two identical orientation frt sites could be excised by the inducible expression of FLP recombinase under the control of hsp promoter. Excision of the als gene was found in 41% re-transgenic tobacco plants, which indicated that this systerm could make a great contribution to obtain the marker free transgenic plants.
Base Sequence ; DNA Nucleotidyltransferases ; metabolism ; Molecular Sequence Data ; Plants, Genetically Modified ; genetics ; Polymerase Chain Reaction ; Promoter Regions, Genetic ; Recombination, Genetic ; Tobacco ; genetics

OBJECTIVETo optimize the synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid.

METHODUsing the DNA assembler method, one copy of Glycyrrhiza glabra beta-amyrin synthase (GgbAS), Medicago truncatula oleanolic acid synthase (MtOAS) and Arabidopsis thaliana cytochrome P450 reductase 1 (AtCPR1) genes were introduced into Saccharomyces cerevisiae strain BY-OA, resulting in strain BY-20A. YPD medium with different glucose concentration were then used to cultivate strain BY-2OA.

RESULTIncreasing gene copies of GgbAS, MtOAS and AtCPR1 resulted in increased beta-amyrin and oleanolic acid production. The strain BY-2OA produced 136.5 mg x L(-1) beta-amyrin and 92.5 mg x L(-1) oleanolic acid, which were 54% and 30% higher than the parent strain BY-OA. Finally, the titer of oleanolic acid increased to 165.7 mg x L(-1) when cultivated in YPD medium with 40 mg x L(-1) glucose.

CONCLUSIONProduction of oleanoic acid increased significantly in the yeast strain BY-2OA, which can provide the basis for creating an alternative way for production of oleanoic acid in place of extraction from plant sources.

Biomass ; Biotechnology ; methods ; Dose-Response Relationship, Drug ; Fermentation ; Glucose ; pharmacology ; Oleanolic Acid ; biosynthesis ; Saccharomyces cerevisiae ; cytology ; drug effects ; metabolism

OBJECTIVETo investigate the dynamic changes of the epididymal size 1 year after vasectomy.

METHODSFifty male volunteers received vasoligation. Before and at 1, 2, 3, 6, and 12 months after operation, we measured the size and detected the internal echoes of the epididymis using color Doppler ultrasonography.

RESULTSThe bilateral epididymides were both thickened post-operatively in all the 50 cases, with statistically significant differences between the baseline and the 1st month, the 1st and the 2nd month, the 2nd and the 3rd month, or the 3rd and the 6th month after surgery (all P < 0.01), but not between the 6th and the 12th month (P > 0.05).

CONCLUSIONWithin 6 months after vasectomy, the bilateral epididymides manifested a progressive thickening, but basically restored their balance of secretion-absorption after 6 months.

Epididymis ; diagnostic imaging ; pathology ; physiology ; Humans ; Male ; Organ Size ; Postoperative Period ; Time Factors ; Ultrasonography, Doppler, Color ; Vasectomy

Objective To evaluate 99Tcm-Arg-Glu-Ser (99Tcm-RES) as a potential tumor imaging agent. Methods RES was synthesized using solid phase peptide synthesis. The optimal labeling conditions of RES were determined under different reagents and reacting temperatures using SnC12 as reducing agent.The biodistribution of 99Tcm-RES was studied in nude mice bearing human lung cancer A549. Results The radiochemical purity of 99Tcm-RES was up to 85% and the radiochemical purity was 75% ever after 6 h at room temperature. The tumor uptake of 99Tcm-RES was obvious and the radioactivity ratios of tumor/blood,tumor/heart, tumor/liver, tumor/lung, tumor/spleen and tumor/muscle were 5.31, 1.88, 1.57, 3.58,4. 16 and 5.92, respectively at 6 h after 99Tcm-RES injection. Gamma camera imaging showed that tumor uptake of 99Tcm-RES was negative in rabbits with inflammatory mass but positive in those bearing tumor.The radioactivity ratio of tumor/inflammation was 3.12 at 6 h after injection. Conclusion 99Tcm-RES might possibly become a potential tumor imaging agent.

OBJECTIVETo investigate the effect of 5-Aza-2'-deoxycytidine (5-Aza-dC) on TIP30 gene expression and the relationship between TIP30 expression and the sensitivity to 5-fluouracil (5-Fu) in colorectal cancer cells.

METHODSThe methylation profile of TIP30 gene in HCT116 colorectal cancer cells was determined by methylation-specific PCR. The levels of TIP30 mRNA and protein were determined by RT-PCR and Western blot after the 5-Aza-dC treatment. MTT assay was used to detect the chemosensitivity of HCT116 cells to 5-Fu.

RESULTSTIP30 gene displayed complete DNA methylation in the HCT116 cells without 5-Aza-dC pretreatment. After the 5-Aza-dC treatment for 3 days, only demethylating PCR amplification product was detected and TIP30 gene showed DNA demethylation. With the prolongation of the time of removal of 5-Aza-dC treatment, methylated and demethylated PCR amplification products were observed and TIP30 gene displayed both DNA methylation and DNA demethylation in the colorectal cancer cells. At the day 10 after removal of 5-Aza-dC, methylating PCR amplification product appeared and TIP30 gene showed DNA methylation. No expressions of TIP30 mRNA and protein were detected in the HCT116 cells untreated with 5-Aza-dC. After the treatment of 5-Aza-dC for 3 d and then removed the 5-Aza-dC, the expressions of TIP30 mRNA and protein were increased obviously. With the prolonged time after 5-Aza-dC removal, the expressions of TIP30 mRNA and protein decreased and reached the lowest level on day 10. The IC50 values of 5-Fu were 41.62, 33.17 and 4.96 µg/ml in the HCT116 cells pretreated with 5-Aza-dC, d0 and d10 with the drug removal after drug treatment for 3 d, respectively.

CONCLUSIONSThe results of this study show that the expression of TIP30 gene may be associated with its DNA methylation status and may affect the sensitivity of colorectal cancer cells to 5-Fu.

Acetyltransferases ; genetics ; metabolism ; Antimetabolites, Antineoplastic ; pharmacology ; Azacitidine ; analogs & derivatives ; pharmacology ; Cell Proliferation ; drug effects ; CpG Islands ; genetics ; DNA Methylation ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Fluorouracil ; pharmacology ; Gene Expression Regulation, Neoplastic ; HCT116 Cells ; Humans ; Inhibitory Concentration 50 ; RNA, Messenger ; metabolism ; Transcription Factors ; genetics ; metabolism

OBJECTIVETo prepare monoclonal antibody (mAb) against prM epitope.

METHODSThe gene encoding prM was isolated using RT-PCR from brain of JEV infected mouse and cloned into prokaryotic expression vector pET-32a. Recombinant plasmid was transformed into E.coli BL21/DE3/LysS, then the transformed cells were expressed with the induction of IPTG. The expression and purification of the prM protein was analyzed by SDS-PAGE. The BALB/c mice were immunized with purified prM protein. Hybridoma cell lines secreting monoclonal antibodies against prM were established after cell fusion of mouse splenic cell and P3-X63-Ag8.653 cells. The specificity of mAb was identified by ELISA, Western Blot and Immunohistochemistry assay.

RESULTSmAb against prM epitope of JEV was prepared successfully.

CONCLUSIONThe obtained prM specific mAb was valuable for the prevention and dignosis of Japanese encephalitis.

Animals ; Antibodies, Monoclonal ; analysis ; immunology ; isolation & purification ; Antibody Specificity ; BALB 3T3 Cells ; Cell Line ; Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Encephalitis Virus, Japanese ; genetics ; immunology ; Epitopes ; immunology ; Escherichia coli ; genetics ; Mice ; Plasmids ; genetics ; metabolism ; Prokaryotic Cells ; metabolism ; Sequence Analysis, DNA ; Viral Proteins ; biosynthesis ; genetics ; immunology ; isolation & purification

A two-stage pH control method was employed in batch fermentation of curdlan by Alcaligenes faecalis WX-C12 where cell-growth stage was constantly controlled at pH 7.0 and stationary stage was controlled at a constant pH as well. The influence of pH control on the curdlan production was investigated. The optimal pH control of batch process for curdlan production was obtained when cell-growth stage was controlled at pH 7.0 and stationary stage was constantly controlled at pH 5.6. Production and productivity of curdlan, QP and YP/S reached 28.19 g/L, 291 mg/(L.h), 132.27 mg/(L.h.g) and 0.659, an improvement of 20.4%, 38.1%, 38.1% and 29.5% compared to a pH uncontrolled operation respectively.
Alcaligenes ; growth & development ; metabolism ; Fermentation ; Glucans ; biosynthesis ; Hydrogen-Ion Concentration ; beta-Glucans

Persistent baculovirus infection is observed frequently in insect populations. Persistent infection can be transformed to a replicative and infective state caused by stress factors and plays an important role in regulating the size of insect population and in epizoology of baculoviruses. The aim of this study is to establish a persistently baculovirus-infected cell system to explore the molecular mechanisms of baculoviral persistence. Spodoptera exigua nucleopolyhedrovirus (SeMNPV) was serially undiluted passaged in Se301 cells to reduce virulence. Upon infection of Se301 cells with the SeMNPV up to passage 8, a few cells survived even if most of cells died due to virus infection. The surviving cells were passaged and designated as P8-Se301 cell strain. P8-Se301 cells had a population doubling time of 58-65 hours and grew slower than Se301 cells. Light microscopy and electron microscopy observation showed symptom of baculovirus infection, such as virogenic stroma, viral particles and occlusion bodies, in some of P8-Se301 cells. End-point dilution assay and infectious center assay showed that 4.14% +/- 0.99% cells continually released infectious progeny virus which replicated slower than SeMNPV in Se301 cells. The result indicated that P8-Se301 cells show a typical character trait of baculovirus persistent infection.
Animals ; Cells, Cultured ; Nucleopolyhedrovirus ; growth & development ; physiology ; Spodoptera ; virology ; Virus Cultivation ; methods