To explore the regularity for the multiplication of avian influenza virus subtype H9N2 in large-scale microcarrier-based MDCK cell culture system, and to determine the optimal proliferation conditions. H9N2 subtype of avian influenza virus was inoculated into the MDCK cell growing on 24 well plate, and the HA titers of virus at different time were detected in the conditions of different infectious doses,different concentrations of TPCK- trypsin and different pH. The optimal conditions were determined. Then the H9N2 subtype avian influenza virus was grown in microcarrier-based MDCK cell in 250mL and 5L roller bottles. It was demonstrated that high viruse yield with a hemagglutination unit of 9 log2(1:512) could be obtained under the optimal conditions of multiplication . The result indicated the H9N2 subtype avian influenza virus could be produced in microcarrier-based MDCK cell in a large-scale culture system with a high virus yield and demonstrates the feasibility of the development of mammalian cell-based in influenza vaccine in microcarrier culture systems.

Objective To investigate the suppression effect of expressing parvovirus H-1 nonstructural protein 1 (NS1) gene on human gastric cancer cells and the possible mechanisms.Methods A recombinant enhanced green fluorescent protein (eGFP) labeled NS1 of parvovirus H-1 plasmid was constructed.Human gastric cancer cell line SGC7901 was transfected with recombinant plasmid (experiment group) or blank vector (negative control group) and blank control group was treated with equal amount of phosphate buffered saline (blank control group).After transfection,the distribution of fluorescent signal was observed under fluorescent microscope.The expression of NS1 at gene and protein level was measured.Cell growth curve of each group was drawn.The expression of cell senescence-associated β-galactosidase (SA-β-Gal) was tested.The changes of cell cycle were investigated by flowcytometry.Two groups' comparision was performed by t-test.Results After transfection,NS1 was expressed in SGC7901 cells at gene and protein level.Compared with negative control group,the fluorescent signal accumulated in cell nucleus in experiment group.The percentage of SA-β-Gal positive cell in experiment group ((30.5 ± 1.4) ％) was higher than that of negative control group ((4.4± 1.1) ％) and the difference was statistically significant (t =-12.931,P ＜ 0.01).The growth inhibition rate of SGC7901 cells from the first day to the fourth day was 45％,62％,73％ and 77％,respectively.The cell cycle of eGFP-NS1 expressed SGC7901 cells was arrested at G0/G1 phase.Conclusion Parvovirus H-1 NS1 play the role in cell nucleus of gastric cancer cell line SGC7901 and could make cell cycle arrested at G0/G1 phase,which effectively inhibited the proliferation SGC7901 cell.

Background As a main suppressing neurotransmitter in visual system,gamma-aminobutyric acid (GABA) participates in the transmission and regulation of visual information.GABA and dopamine (DA) coexist in the visual cortex,and their mutual effects should be clarified.Objective This study was to investigate the effect of DA on GABA-activated current in vitro in cultured visual cortical neurons of rats.Methods Neutrons from visual cortex of clean neonatal rats were isolated and cultured by explant culture method.The neutrons cultured for 11 -to 14- days were collected for the record of whole cell currents of GABA-A (IGABA) channels in vitro using patch clamp technique.The DA solution (100mmol/L),SKF38393 (10mmol/L) solution and quinpirole solution(10mmol/L) were prepared with double distilled water and then the extracellular fluid was added to different concentrations.The IGABA changing rate under the action of SKF38393+SCH23390,SKF38393+Quinpirole for different time was recorded respectively and compared with that of action of DA,SKF38393,SCH23390,Quinpirole.The IGABA activated by extracellular fluid along served as control.Results The IGABA was significantly attenuated after activated by ≥10μmol/L of DA or SKF38393 separately in comparison to that of extracellular fluid action (P＜0.05).In various time of action,there were obviously differences in IGABA between DA or SKF38393 action and extracellular fluid (P＜0.05,P＜0.01).No evident change in IGABA changing rate was found after only SCH23390 action in comparison with extracellular cells (P＜0.05).However,after combination of SCH23390 and SKF38393,IGABA changing rate reduced by 19.49%.No significant differences were found in the changing rates of IGABA among different concentrations of quinpirole action groups compared with extracellular fluid group (P＞0.05);while when quinpirole was combined with SKF38393,the IGABA was elevated in comparison with only SKF38393 action group (P＜0.05).Conclusion Dopamine participates in the transfer and regulation of visual information through suppressing GABA-activated currents from neutrons of visual cortex at time-dependent manner in vitro.

Flavonoids are a class of important active ingredients in traditional Chinese medicine, pharmacological activity and in vivo process is the focus of research in recent years. Calycosin is the main active ingredients of flavonoids in Astragali Radix, recent studies indicate that it has many kinds of pharmacological activity, but the absorption and transport characteristics in vivo is unclear. The experiment using Caco-2 cell model, with apigenin as internal standard substance, using the method for the determination of drug concentration by HPLC, were studied at different concentrations and absorption transport characteristics of respectively adding different types of protein inhibitors. Data were analyzed by Q test, the results show that low, middle, high concentration of P(app)(BL-AP)/ P(app)(AP-BL) = 1.38 < 1.5, respectively adding different types of protein inhibitors, compared with the control group of P(app)(BL-AP)/ P(app)(AP-BL), there were no significant differences. Calycosin absorption may mainly passive transport, also involved in active transport mechanism, the transport may not be affected by the P-protein, MRP2 protein, SGLT protein.
Absorption ; Biological Transport ; Caco-2 Cells ; Chromatography, High Pressure Liquid ; Culture Media, Conditioned ; chemistry ; Drug Stability ; Drugs, Chinese Herbal ; analysis ; pharmacokinetics ; Humans ; Hydrogen-Ion Concentration ; Isoflavones ; analysis ; pharmacokinetics ; Models, Biological

A new dynamic in vitro intestinal absorption model for screening and evaluating lipid formulations was established by means of the characteristics of the intestinal digestion and absorption of the lipid formulations. This model was composed of two systems, including intestinal digestion and the intestinal tissue culture, which drew the evaluation method of intestinal absorption into the in vitro lipolysis model. The influence of several important model parameters such as Ca2+, D-glucose, K+ on the two systems of this model has been investigated. The results showed that increasing of Ca2+ concentration could be significantly conductive to intestinal digestion. The increasing of D-glucose concentration could stepped significantly down the decay of the intestinal activity. K+ was able to maintain intestinal activity, but the influence of different concentration levels on the decay of the intestinal activity was of no significant difference. Thus the model parameters were set up as follows: Ca2+ for 10 mmol x L(-1), D-glucose for 15 mmol x L(-1) and K+ for 5.5 mmol x L(-1). Type I lipid formulation was evaluated with this model, and there was a significant correlation between the absorption curve in vitro and absorption curve in vivo of rats (r = 0.995 6, P < 0.01). These results demonstrated that this model can be an attractive and great potential method for the screening, evaluating and predicting of the lipid formulations.

This paper report the development of a new dosage form - self-microemulsifying mouth dissolving films, which can improve the oral bioavailability of water insoluble drugs and have good compliance. A three factor, three-level Box-Behnken design was used for optimizing formulation, investigated the effect of amounts of microcrystalline cellulose, low-substituted hydroxypropyl cellulose and hypromellose on the weight, disintegration time, cumulative release of indomethacin after 2 min, microemulsified particle size and stretchability. Optimized self-microemulsifying mouth dissolving films could fast disintegrate in (17.09 +/- 0.72) s; obtain microemulsified particle size at (28.81 +/- 3.26) nm; and release in vitro at 2 min to (66.18 +/- 1.94)%. Self-microemulsifying mouth dissolving films with broad application prospects have good compliance, strong tensile and can be released rapidly in the mouth through fast self-microemulsifying.

Solid carriers had important effects on the properties of solid self-microemulsifying drug delivery systems (S-SMEDDS). In order to make the basis for further development of S-SMEDDS, the influences of silica on the absorption of S-SMEDDS were investigated. An in vitro lipolysis model was used to evaluate the influence of silica on self-microemulsifying drug delivery system digestion from intestinal tract. S-SMEDDS containing silica were prepared by extrusion/spheronization. The drug release and absorption were investigated. The results showed that lipolysis rate and drug concentration in aqueous phase after intestinal lipolysis both increased by adding silica, which was benefit to drug absorption. And silica was not benefit to absorption for slowing drug release. Consistently, there was no significant influence of silica on intestinal absorption. This study implied that the influences of silica on lipolysis rate and drug release were both amount dependent and it is suggested that silica could be used as the solid carrier but the proportion needs to be optimized.

The distribution fate and solubilization behavior of indomethacin through the intestinal tract were investigated with in vitro lipolysis model, by comparing the Capmul MCM and Labrafil M 1944 CS type I lipid formulations. The results showed that the more favorable solubilization was in the aqueous digestion phase from each lipid formulations for indomethacin. The lipolysis rate and extent were decided with chemical constitution of the lipid excipients, which meant that less indomethacin was transferred from the long chain polar oil lipid solution into the aqueous digestion phase. Increasing the concentration of indomethacin in the lipid formualitons from a solution to a suspension led to a linear increase in the concentration of indomethacin attained in the aqueous digestion phase from lipid formulations. This study also implied that adverse effects of the lipolysis rate and extent on drug absorption were could be taken into consideration when screening lipid formulations. Lipid suspensions likely had better enhancement of drug absorption. Last, this study demonstrated that a potential basis for optimizing and assessing type I lipid formulations and also researching in vivo-in vitro correlations of lipid formulations were provided by an in vitro lipolysis model.

The intraspecies quorum sensing system of Streptococcus mutans is involved with com genes family.ComE is a kind of response regulator and act as a promoter to the quorum sensing genes.S.mutans comE mutant strain IFD140?comE was constructed using the inframe-deletion system via twice homologous recombination.In current genetic studies of S.mutans,insertion duplication and allelic exchange mutagenesis techniques routinely create polar effects to downstream genes.In-frame deletions are essentially free of these polar effects because the mutation does not introduce any genetic markers.By PCR,sequencing and RT-PCR,it was confirmed that IFD140?comE has only 717bp deleted within the comE gene and the transcription of the downstream gene comD was not interfered.The research of the morphological characteristics indicated that IFD140?comE formed clumps and cells accumulated at the bottom of the glass tubes and light-microscopic observations displayed that the mutant strain formed significantly longer chains compared to those formed by the wild strain.The successfully construction of IFD140?comE lay a foundation for further quorum sensing research.

Study on the effects of Astragali Radix main active flavone calycosin-7-O-β-D-glucoside on Saposhnikoviae Radix main active ingredients prim-O-glucosylcimifugin and cimifugin, a UPLC-MS/MS method for simultaneous determination of prim-O-glucosylcimifugin and cimifugin in rat plasma was established, and the comparative pharmacokinetics of prim-O-glucosylcimifugin and cimifugin after oral administration of prim-O-glucosylcimifugin and calycosin-7-O-β-D-glucoside-prim-O-glucosylcimifugin to rats were carried out, which might be conductive in exploring the rationality of Astragali Radix - Saposhnikoviae Radix herb couple. Twelve male SD rats were divided into two groups. Prim-O-glucosylcimifugin and cimifugin in rat plasma of different time points after oral administration of prim-O-glucosylcimifugin and calycosin-7-O-β-D-glucoside - prim-O-glucosylcimifugin to rats were determinated. And the main pharmacokinetic parameters were investigated using DAS 3. 2. 4. The established method was rapid, accurate and sensitive for simultaneous determination of prim-O-glucosylcimifugin and cimifugin in rat plasma. The analysis was performed on a Waters Acquity BEH C18 column (2.1 mm x 100 mm, 1.7 μm) with the mixture of acetonitrile and 0.1% formic acid/water as mobile phase, and the gradient elution at a flow rate of 0.3 mL x min(-1). The analytes were detected by tandem mass spectrometry with the electrospray ionization (ESI) source and in the multiple reaction monitoring (MRM) mode. Compared with prim-O-glucosylcimifugin group, the AUC(0-t)., and AUC(0-∞) of p-O-glucosylcimifugin as well as the C(max) of cimifugin significantly increased (P < 0.05) in calycosin-7-O-β-D-glucoside-prim-O-glucosylcimifugin group. Calycosin-7-O-β-D-glucoside could enhance the absorption of prim-O-glucosylcimifugin and cimifugin and improve the bioavailability, explaining preliminarily the rationality of Astragali Radix-Saposhnikoviae Radix herb couple.
Animals ; Chromatography, High Pressure Liquid ; Chromones ; blood ; pharmacokinetics ; Drug Interactions ; Drugs, Chinese Herbal ; pharmacokinetics ; Glucosides ; blood ; pharmacology ; Isoflavones ; blood ; pharmacology ; Male ; Monosaccharides ; blood ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Xanthenes ; blood ; pharmacokinetics