A temperature control system for quantitive polymerase chain reaction (PCR) is presented in the paper with both software and hardware configuration. The performance of the control system has been improved by optimizing the software and hardware design according to the system's properties. The control system has been proven to have a good repeatability and reliability as well as high control precision.
Equipment Design ; Microcomputers ; Polymerase Chain Reaction ; instrumentation ; Software ; Software Design ; Temperature

According to the designed specific primers of gene fragment based on the Salvia miltiorrhiza transcriptome data, with the method of reverse transcription polymerase chain reaction (RT-PCR), this study cloned full-length cDNA sequence of 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase gene from Salvia miltiorrhiza bge.f.alba, this sequence is named as SmHDS and its GenBank registration number is KJ746807. SmHDS, 2 529 bp long, contains an ORF of 2 229 bp, encodes 742 amino acids, including 5' UTR 170 bp and 3' UTR 130 bp. Using bioinformatics software, having made a homology analysis of the obtained sequence, we can have a conclusion that SmHDS have a close genetic relationship with HDS of Salvia miltiorrhiza. Analysis result of prokaryotic expression revealed that in Escherichia coli, SmHDS expressed target proteins which in size are comparable with the protein predicted. Meanwhile, the 4 factors which can influence the protein expression were optimized, the 4 factors are inducing temperature, inducing time, IPTG concentrations and density of inducing host bacterium (A600). The optimal expression conditions of SmHDS were 30 degrees C until the A600 is 0.6, and add IPTG to a final concentration of 0.2 mmol x L(-1), and the induction time of 20 h. It provides theoretical basis for the further study of the function of 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase in the biosynthesis of tanshinone compounds.
Cloning, Molecular ; DNA, Complementary ; genetics ; Diterpenes, Abietane ; biosynthesis ; Enzymes ; biosynthesis ; genetics ; Escherichia coli ; metabolism ; Plant Proteins ; biosynthesis ; genetics ; Salvia miltiorrhiza ; enzymology ; genetics

Soxhlet extraction is a common method of sample preparation. However, there has been no discussion about the efficiency of Soxhlet extraction from different batches and the factors that cause content fluctuation. In this study, Panax ginseng was selected as a model sample. Soxhlet extraction by means of a water bath, which has always been neglected, was identified as a novel key factor in the poor repeat-ability in different batches of Soxhlet extraction, as it can affect the siphon times and reflux time, which have been positively correlated with the ginsenoside contents. By substituting round bottom flasks in the same column, the relative standard deviation of the most fluctuated compound, ginsenoside Rb1, was decreased from 24.6% to 5.02%. Scanning electron microscopy analysis confirmed that the breakdown of the surface of the ginseng powder in the Soxhlet extraction led to a better dissolution of ginsenosides, indicating that chloroform may promote the extraction of ginsenosides by disrupting the cell structure. Moreover, 70% methanol was regarded as the better solvent for extracting the ginsenosides. Overall, this work offers a practical and effective protocol for improving the accuracy and repeatability of Soxhlet extraction methodology for ginsenosides and other analytes.

AIMTo study the transfection and anti-hepatitis B virus (HBV) effect of the co-modified hepatocytes-targeting cationic liposomes encapsulating anti-HBV antisense oligonucleotides (asON) , and to investigate the transfection mechanisms of the liposomes.

METHODSDipalmitoylphosphatidylcholine (DPPC) and 3beta-[N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) were used as the lipids, beta-sitosterol-beta-D-glucoside (sito-G) and Brij 35 were used to modify the liposomes. Flow cytometry (FCM), fluorescence microscopy and enzyme-linked immunosorbent assay (ELISA) were utilized to evaluate the transfection improvement of the asON encapsulated in the liposomes in primary rat hepatocytes and the antigens inhibition activity in HepG 2.2.15 cells. The transfection mechanisms were evaluated based on the influence of wortmannin, nigericin, and asialofetuin on the antigens inhibition in HepG 2.2.15 cells by ELISA.

RESULTSThe co-modification with sito-G and Brij 35 significantly improved the transfection of the liposomes in primary rat hepatocytes and antigens inhibition effect in HepG 2.2.15 cells. Both transfection efficiency and antigens inhibition effect showed to be concentration-dependent with the asON-encapsulating liposomes. In fluorescence microscopy, the transfected cells showed strong fluorescence in primary rat hepatocytes, especially in the nuclei. Wortmannin, nigericin and asialofetuin decreased the antigens inhibition of the asON-encapsulating liposomes to different levels. Cationic liposomes modification with sito-G and Brij 35 could improve the transfection and antigens inhibition effect of the asON. The transfection mechanisms of the co-modified liposomes included endocytosis and membrane fusion. The ligand sito-G was confirmed to be able to enhance asialoglycoprotein receptor (ASGPR)-mediated endocytosis.

CONCLUSIONCo-modified hepatocytes-targeting cationic liposomes would be a specific and effective carrier to transfer asON into hepatocytes.

Androstadienes ; pharmacology ; Animals ; Asialoglycoproteins ; pharmacology ; Cell Line, Tumor ; Cell Nucleus ; metabolism ; Cell Survival ; Cells, Cultured ; Endocytosis ; drug effects ; Female ; Fetuins ; Flow Cytometry ; Hepatitis B Antigens ; metabolism ; Hepatitis B virus ; genetics ; immunology ; Hepatocytes ; cytology ; drug effects ; metabolism ; Humans ; Liposomes ; Microscopy, Fluorescence ; Nigericin ; pharmacology ; Oligonucleotides, Antisense ; chemistry ; genetics ; Polyethylene Glycols ; chemistry ; Rats ; Rats, Wistar ; Sitosterols ; chemistry ; Transfection ; methods ; alpha-Fetoproteins ; pharmacology

Aged ; Arthroplasty, Replacement, Knee ; methods ; Female ; Femur ; surgery ; Humans ; Osteoarthritis ; surgery ; Osteotomy ; methods

Objective To explore the activation and function of Janus protein-tyrosine kinase (JAK)/ signal transducer and activator of transcription (STAT1) signal transduction pathway in kidney,lung and brain of MRL/lpr mice.Methods MRL/lpr mice with systemic lupus erythematosus (SLE) were studied at the age of 12 weeks up.Non-SLE MRL/lpr mice were used as controls.We used phosphospecific antibodies to detect STAT1 activation in kidney,lung and brain by immunohistochemistry and Western blots.Gene expression of the STAT induced feedback inhibitors of cytokine signaling 1 (SOCS-1) was investigated by SYBR green I real-time reverse transcriptase polymerase chain reaction (PCR).Results Phosphorylation of STAT1 protein was markedly activated in these three organs,although renal and pulmonary STAT1 activation were much more evidently activated.SOCS-1 gene expression increased in all three organs,while renal SOCS-1 gene expres- sion increased less than lung and brain.Conclusion The activation of JAK/STATI signal transduction path- way may be pathogenic in the organ involvement and progression of SLE.The pathogenesis of lupus nephritis may also be associated with the down-regulation of SOCS-1 feedback inhibition.

Objective To establish a LC-MS/MS method for pharmacokinetics study of methylergonovine in healthy Chinese volunteers after single and multiple-dose administration of methylergonovine maleate tablets. Methods 6-hydroxyflavone was used as internal standard.The separation was achieved on a Waters Xterra C18 (2. 1 mm × 100 mm, 3. 5 μm) with a mobile phase consisting of 0. 05％ ammonium acetate and methanol-acetonitrile (80:20) solution. At a flow rate of 0. 3 m L·min-1 within 12 min. Methylergonovine and 6-hydroxyflavone were measured by ESI in positive electron mode using multiple reaction monitoring (MRM) . The extracted ions monitored following MRM transitions were m/z 340. 3 →223. 2 for methylergonovine and m/z 239. 2 →129. 1 for 6-hydroxyflavone. Plasma samples were pretreated by liquid-liquid extraction. Results The calibration curve was linear within the range of 0. 1-20. 0 ng·m L-1. The Lower limit of quantitation was 0. 1 ng·m L-1 and CV％ of intra-and inter-day were less than 15％. The plasma samples were stable at room temperature (25 ℃) for 4 h, at-70℃ for 4 months and during three freeze-thaw cycles. There was no accumulationafter ultiple-dose of methylergonovine maleate tablets.Conclusion The method was proved to be accurate and sensitive suitable for the pharmacokinetics of methylergonovine in volunteers after oral administration of 0. 125, 0. 25, 0. 5 mg methylergonovine maleate tablets.

AIMTo investigate the effect of brassinolide, a plant growth modulator, on multidrug resistance (MDR) of human T lymphoblastoid cell line CCRF-VCR 1000 which was obtained by progressively addition of vincristine (VCR) to sensitive CCRF-CEM cells, and to explore preliminarily the mechanism of reversing action.

METHODSMTT method was used to detect the resistant factor of resistant cell line and the reversing fold after addition of brassinolide. The intracellular accumulation of rhodamine 123, a fluorescent dye transported by P-glycoprotein was detected by flow cytometry, the catalytic activity of topoisomerase II was assessed by Sulliven method to find the effect of brassinolide on resistance. The protein expression of p53 was measured using Western blotting in the sensitive cells and resistant cells to explore the effect of brassinolide.

RESULTSThe resistant factors of CCRF-VCR cells on adriamycin, VP-16 and VCR are respectively as 153.1, 55.9 and 8123.1 folds comparing to the sensitive cell line CCRF-CEM. After treatment of brassinolide under the concentration of 0.001 - 10.0 microg x mL(-1), the resistance of CCRF-VCR was reversed partly with the reversing folds respectively as 4.4 - 11.6. The intracellular accumulation of rhodamine 123 was significantly reduced in the resistant cells. After treatment of brassinolide, the accumulation increased, the level of fluorescent dye was situated between resistant cells and sensitive cells. No alteration of the catalytic activity of topoisomerase II was found among three groups. The level of protein expression of p53 in resistant cells was higher than that of sensitive cells. After brassinolide treatment, the expression of p53 in CCRF-VCR cells restored to the level of sensitive cells.

CONCLUSIONBrassinolide could effectively reverse the resistance of CCRF-VCR cells by inhibiting the effusion of drug transported by P-glucoprotein. To down regulate the abnormal expression of p53 maybe one of the mechanisms of reversing MDR for brassinolide.

Brassica rapa ; chemistry ; Brassinosteroids ; Cell Line, Tumor ; drug effects ; Cholestanols ; isolation & purification ; pharmacology ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Humans ; Leukemia, T-Cell ; metabolism ; pathology ; Plant Growth Regulators ; pharmacology ; Pollen ; chemistry ; Steroids, Heterocyclic ; isolation & purification ; pharmacology ; Tumor Suppressor Protein p53 ; metabolism

AIMTo study the metabolic kinetics of MN9202 in Beagle dog liver microsome.

METHODSBeagle dog liver microsomes were prepared by using ultracentrifuge method. After incubating 0.4 micromol x L(-1) MN9202 with 1 g x L(-1) microsomes for 30 min at 37 degrees C, the reaction was terminated by adding 0.5 mL alkalization. The RP-HPLC was used to determine the drug in the incubation mixture. The Michaelis-Menten parameters Km, and Vmax in Beagle dog liver microsomes were initially estimated by analyzing Lineweave-Brurk plot. Various selective CYP inhibitors were used to investigate their inhibitory effect on the metabolism of MN9202.

RESULTSThe Km, Vmax and CLint of MN9202 were (22.6 +/- 8.0) micromol x L(-1), (0.54 +/- 0.17) micromol x g(-1) x min(-1) and (0.0242 +/- 0.0009) L x g(-1) x min(-1), respectively. The metabolism of MN9202 was significantly inhibited by ketoconazole (Ket) and troleandomycin (Tro) in Beagle dog liver microsomes. Tranylcypromine (Tra) could inhibit the metabolism of drug as well. While other inhibitors showed little inhibitory effect on the metabolism of MN9202.

CONCLUSIONIt was shown that CYP3A and CYP2C19 were involved in MN9202 metabolism. The inhibitors of human CYP3A and CYP2C19 may have potential interaction with MN9202, and this can reduce the metabolism rate and increase the toxicity of MN9202.

Animals ; Aryl Hydrocarbon Hydroxylases ; antagonists & inhibitors ; Calcium Channel Blockers ; metabolism ; pharmacokinetics ; Cytochrome P-450 CYP2C19 ; Cytochrome P-450 CYP3A Inhibitors ; Dihydropyridines ; metabolism ; pharmacokinetics ; Dogs ; Ketoconazole ; pharmacology ; Microsomes, Liver ; metabolism ; Mixed Function Oxygenases ; antagonists & inhibitors ; Nitrobenzenes ; metabolism ; pharmacokinetics ; Tranylcypromine ; pharmacology ; Troleandomycin ; pharmacology

AIMTo study preventive and therapeutic effect of zinc sulfate on lung injury during superior mesenteric artery occlusion (SMAO) shock and their mechanism of action.

METHODSModel of rabbit SMAO shock was made. The effect of zinc sulfate on the malondialdehyde (MDA) in erythrocyte membrane and plasma, oxidase (XOD) in plasma, superoxide dismutase (SOD) in erythrocyte and MDA, SOD and pulmonary surfactant (PS) in lung tissues homogenate were observed.

RESULTSThe administration of zinc sulfate decreased MDA and XOD, prevented the reduction of SOD and PS, and alleviated lung injury.

CONCLUSIONIt is suggested that lung is injured during SMAO shock and zinc sulfate possesses preventive and therapeutic effect, through stabilized membrane.

Animals ; Female ; Lung ; metabolism ; Lung Injury ; drug therapy ; etiology ; metabolism ; Male ; Mesenteric Artery, Superior ; pathology ; Mesenteric Vascular Occlusion ; complications ; drug therapy ; metabolism ; Rabbits ; Shock ; complications ; drug therapy ; metabolism ; Zinc Sulfate ; therapeutic use