In order to develop a simple and efficient site-directed mutagenesis solution, the Gibson assembly technique was used to clone the cyclin dependent kinase 4 gene with single or double site mutations, with the aim to simplify the overlap extension PCR. The gene fragments containing site mutations were amplified using a strategy similar to overlap extension PCR. Meanwhile, an empty plasmid was digested by double restriction endonucleases to generate a linearized vector with a short adaptor overlapping with the targeted gene fragments. The gene fragments were directly spliced with the linearized vector by Gibson assembly in an isothermal, single-reaction, creating a recombinant plasmid. After the recombinant plasmids were transformed into competent Escherichia coli DH5α, several clones were screened from each group. Through restriction analysis and DNA sequencing, it was found that the randomly selected clones were 100% target mutants. Since there was neither tedious multiple-round PCR amplification nor frequent DNA extraction operation, and there was no need to digest the original plasmid, this protocol circumvents many factors that may interfere with the conventional site-directed mutagenesis. Hence, genes with single or multiple mutations could be cloned easily and efficiently. In summary, the major defects associated with overlap extension PCR and rolling circle amplification were circumvented in this protocol, making it a good solution for site-directed mutagenesis.
Clone Cells ; Mutagenesis, Site-Directed ; Mutation ; Plasmids/genetics* ; Polymerase Chain Reaction/methods*

Overlap extension PCR is a common method for site-directed mutagenesis. As objective gene sequence growing longer, it is often difficult to obtain the target product in the second round of PCR, and it is highly possible to introduce unexpected mutations into a long gene fragment by PCR. To circumvent these problems, we can only amplify a small gene fragment which contain the target mutation by overlap extension PCR, and then ligate it with vector to get target plasmid. If the restriction site at the end of the amplified fragment was not a single one on plasmid vector, double fragments ligation method could be used to construct target plasmid. Partial amplification, combined with double fragments ligation, could solve lots of problems in long gene mutagenesis. Taking retinoblastoma gene 1 S780E mutagenesis as an example, it is difficult to amplify whole retinoblastoma gene 1 by overlap extension PCR because of long fragment interfering the overlapping extension of second round PCR. However, it is relatively easy to amplify the F3 (1 968-2 787) fragment which contains target mutation S780E. There is a Nhe I site which can be used for ligation on 5' end of F3 fragment, but another Nhe I site on the plasmid restrained from doing so directly. In order to circumvent this obstacle, we ligated F3 fragment, combining with F2 (900-1 968) fragment which was digested from wild type plasmid, with the vector which contain F1 (1-900) fragment of the gene. That double fragments ligated with one vector at the same time, though less efficient, can recombine into a complete plasmid. The sequences of the two selected recombinant plasmids were consistent with the target mutation, which verified the feasibility of this scheme. As an improvement of overlap extension PCR, partial amplification and double fragments ligation methods could provide solutions for site directed mutagenesis of many long genes.
Base Sequence ; Cloning, Molecular ; Genetic Vectors ; genetics ; Mutagenesis, Site-Directed ; methods ; Nucleic Acid Amplification Techniques ; Plasmids ; Polymerase Chain Reaction

OBJECTIVE： To determine and compare the contents of catalpol and aucubin in different parts （root， stem， leaf and flower） of wild Centranthera grandiflora， and to provide reference for the selection of medicinal parts and source development. METHODS： HPLC method was used to determine the contents of catalpol and aucubin in root， stem， leaf and flower of wild C. grandiflora， and the contents of different parts were analyzed comparatively. The determination of catalpol was performed on Agilent TC-C18 column with mobile phase consisted of methanol-0.1％ phosphoric acid （1 ∶ 99， V/V） at the flow rate of 1 mL/min； the detection wavelength was set at 210 nm， and sample size was 20 μL. The column temperature was 35 ℃； the determination of aucubin was performed on SPHERI-5RP-C18 column with mobile phase consisted of acetonitrile-water （3 ∶ 97， V/V） at the flow rate of 1 mL/min； the detection wavelength was set at 205 nm， and sample size was 20 μL； the column temperature was 25 ℃. RESULTS： The linear range of catalpol and aucubin were 0.061 5-3.321 and 0.000 36-0.216 mg/mL （all r＝0.999 9）. The limits of detection were 0.016 and 0.007 μg/mL. The limits of quantitation were 0.052 and 0.023 μg/mL. RSDs of precision， stability （24 h） and reproducibility tests were all lower than 2.00％ （n＝6）. The average recoveries were 99.34％ and 99.61％， and RSDs were 1.06％ and 1.12％， respectively （n＝6）. The average content of catalpol in root， stem， leaf and flower wild C. grandiflora were 1.609， 3.030， 11.095 and 1.921 mg/g， respectively. The contents of aucubin in different parts were 0.441， 0.020， 0.005 and 0.006 mg/g，respectively. CONCLUSIONS：The established HPLC method meets the requirements of quantitative analysis. Catalpol is mainly distributed in the leaves of wild C. grandiflora， and aucubin is mainly distributed in the roots of wild C. grandiflora. The experimental conclusion provides a reference for the reasonable selection of different medicinal parts as raw materials to develop medicine with different efficacy.

To screen the specific anti-human intercellular adhesion molecule-1 (ICAM-1) single chain fragment variable (scFv) using phage display library technology and to identify its biological activity. P1 peptide was used as antigen, and the phage antibodies against human ICAM-1 antigen were panned by four binding-eluting-amplifying cycles using Tomlinson I+J phage display library. After four rounds of selective enrichment screening, the positive clones were determined by PCR, enzyme linked immunosorbent assay (ELISA)-based antigenic cross reaction and Dot blotting. Then the binding specificity and biological activity of purified scFv were identified by Western blotting, competitive ELISA and cell adhesion inhibition assay respectively. Furthermore, four positive clones were first panned through P1 peptide coated-ELISA assay, and then J-A1 was obtained and identified by PCR, ELISA-based antigenic cross reaction and Dot blotting, which could show a specific binding between P1 peptide and human ICAM-1 protein antigen. Subsequently, the purified scFv showed a satisfactory specificity and anti-adhesive activity in competitive ELISA and the cell adhesion inhibition assay. The specific anti-human ICAM-1 scFv was prepared successfully from Tomlinson I+J phage display library, which pave the way for further application of anti-human ICAM-1 scFv for inflammation diseases therapeutics.
Antibodies ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin Variable Region ; Intercellular Adhesion Molecule-1 ; immunology ; Peptide Library ; Single-Chain Antibodies

Objective To investigate the clinical efficacy of primary closure in laparoscopic common bile duct exploration (LCBDE).Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 2 429 patients who underwent primary closure in LCBDE in the Second Hospital of Chengdu City from March 1992 to December 2017 were collected.Patients underwent laparoscopic cholecystectomy (LC) + stone extraction using LCBDE or extracorporeal shock wave lithotripsy (ESWL),laparoscopic endoscopic sphincteropapillotomy (LEST) was performed selectively,then underwent laparoscopic endoscopic nasobiliary drainage (LENBD) or laparoscopic transabdominal antegrade-guide common bile duct stent implantation,finally underwent primary closure of common bile duct.Observation indicators:(1) surgical situations;(2) postoperative recovery;(3) postoperative short-term complications;(4) follow-up situation.Follow-up using outpatient examination and telephone interview was performed to observe long-term surgical complications once every 3 months up to 1 year postoperatively.Measurement data with normal distribution were represented as (x) ± s.Measurement data with skewed distribution were described as M (range).Results (1) Surgical situations:of 2 429 patients,2 251 underwent successful stone extraction using LCBDE,relief of the obstruction and primary closure of common bile duct,with depletion of stones;15 underwent stone extraction using conversion to open surgery,with depletion of stones;163 had residual stones or surgery-related complications.Of 2 429 patients,1 144,898,223,110 and 54 were respectively detected in grade N or 0,1,2,3 and 4 of laparoscopic distal of the common bile duct smooth classification (LDSC);599 underwent LEST,367 underwent LENBD,207 indwelled urinary catheter through cystic duct stump,125 underwent laparoscopic transabdominal antegrade-guide common bile duct stent implantation and 1 131 underwent primary closure in LCBDE only.Number of removing the stones,diameter of common bile duct,volume of intraoperative blood loss and operation time was (2.5±0.2)per case,(0.7±0.4)cm,(22.4±2.6)mL and (100±12) minutes,respectively.(2) Postoperative recovery:time of postoperative gastrointestinal function recovery,duration of hospital stay and treatment expenses were respectively (2.5±0.5) days,(7.3± 1.2) days and (2.7±0.3) × 104 yuan.Of 2 429 patients,367 removed nasobiliary catheter at 3-7 days postoperatively,207 removed urinary catheter at 3-6 weeks postoperatively,and 125 removed common bile duct stent through duodenoscope port at 1-4 months postoperatively.(3) Postoperative short-term complications:incidence of postoperative short-term complications in 2 429 patients was 6.711％ (163/2 429).① Ninety-four patients with bile leakage were cured after drainage and symptomatic and supportive treatment.② Of 29 patients with residual stones:25 with residual stones of common bile duct were cured by stone extraction using endoscopic sphincterotomy of duodenal papilla,and 4 with residual stones of intrahepatic bile duct didn't receive treatment.③ One patient died at 15 days after surgery for pancreatic cancer.④ Of 39 with postoperative other complications:2 with postoperative hemorrhage were cured by laparoscopic reoperation;12,19 and 3 were respectively complicated with postoperative inflammatory stenosis of duodenal papilla induced to short-term obstructive jaundice,mild acute pancreatitis and stress ulcer bleeding of upper digestive tract,and they were improved by endoscopy or non-operation treatment;2 with stenosis of bile duct didn't receive treatment;1 had a miss ligation at bending section of front zone of nasobiliary catheter,and ligation was removed by endoscopic retrograde cannulation of the pancreatic at 19 days postoperatively.(4) Follow-up situation:of 2 429 patients,1 749 were followed up for 3-12 months,with a median time of 6 months.During the follow-up,of 1 749 patients,2 had mild stenosis in the primary closure area of common bile duct incision and 1 had stenosis of duodenal papilla,they were not treated,and other patients didn't have related complications.Conclusion Controlling strictly the operative indication,primary closure of common bile duct in LCBDE is safe and feasible,with satisfactory clinical outcomes.

Objective To analyze our experience in primary closure of common bile duct after laparoscopic bile duct exploration.Methods From June 1992 to March 2018,2 740 patients underwent primary closure of common bile duct after laparoscopic common bile duct exploration in the Second People's Hospital of Chengdu.Results The operations were successfully carried out in 2 534 (92.4％) out of 2 740 patients,of whom 15 patients (0.6％) were converted to open common bile duct exploration.Bile leakage occurred in 113 patients (4.1％).Residual stones were found in 29 patients (1.1％).One patient (0.1％) who had a pancreatic carcinoma died on postoperation day 15.48 patients (1.8％) developed other complications.The total postoperative complication rate was 7.0％ (191/2 740).Conclusion In suitable patients,laparoscopic bile duct exploration with primary closure was feasible,safe and effective.

Objective To evaluate laparoscopic balloon nasobiliary biliary drainage (LBNBD),vs ureteral catheter drainage in one stage laparoscopy,choledochoscopy and duodenoscopy choledocholithotomy and primary closure of the small calibered common bile duct (diameter 0.3-0.8 cm).Methods During the period of Apr 2010 to Nov 2016 102 cases were enrolled including 50 cases receiving LBNBD and 52 cases using ureteral catheter drainage.Results Between the two groups,LBNBD was superior to ureteral catheter drainage in all the following parameters:the operation time,intraoperative blood loss,postoperative liver function,blood amylase and other laboratory indicators,gastrointestinal function recovery time,gastrointestinal symptoms and electrolyte imbalance,postoperative hospital stay,and bile duct drainage time with all differences statistically significant (P ＜ 0.05).Bile drainage differences during the postoperative first 3 days (averagely 200-400 ml a day) were not statistically different (P ＞ 0.05).Postoperative pancreatitis,bile leakage,and hemobilia were not statistically different (P ＞ 0.05).Conclusions The use of LBNBD is safe and effective in endoscopic choledocholithotomy in cases of small calibered common bile duct.

To explore the operation methods and indications of the duodenoscopic papillotomy (IEST) with endoscopic nasobiliary drainage (IENBD) for the treatment of duodenal papilla stenosis during the course of common bile duct operation.The clinical data of 219 cases of cholecystolithiasis with choledocholith and the stenosis of papillary underwent endoscopic sphincterotomy (IEST) plus endoscopic nasobiliary drainage (IENBD) in the Second People's Hospital of Chengdu were retrospectively analyzed.It was successful in 198 cases who had the gallbladder and common bile duct stones removed,and endoscopic papillary dissection was performed and the nasobiliary tube was successfully inserted.Nasobiliary drainage was successful in 186 cases (93.9％) of 198 cases.No liquid outflow was observed in nasobiliary drainage in 7 cases (3.5％).Nasal bile duct slipped early in 5 case (2.5％).Primary closure of bile duct incision was completed in 198 cases.It failed in 4 cases (2.0％) who had the bile leakage with primary closure of duct incision.Mild pancreatitis after operation occurred in 3 cases (1.5％).Nose bile duct ligation was performed in 1 case (0.5％).The overall postoperative complication rate was 4.0％ (8/198).IEST + IENBD in open laparotomy was successful in 21 cases.No perforation of intestine and bile duct,bleeding,severe pancreatitis and other complications and death were detected postoperatively in two groups.During the course of laparoscopy and open laparotomy,IEST + IENBD in treating cholecystolithiasis with choledocholith and the stenosis of papillary and primary closure of duct incision after the endoscopic nasobiliary drainage is safe and effective.

AIM:To determine the effects of Tongxinluo (TXL) on connexin 43 (Cx43) remodeling and ven-tricular arrhythmia ( VA) after myocardial infarction ( MI) in rats .METHODS:Male SD rats were randomly divided into sham-operated (sham) group (n=25) and operation group (n=75).The left anterior descending (LAD) was ligated in operated group , while the rats in sham group only underwent pericardiotomy .The rats in operation group which survived for 3 d after operation were randomly assigned to TXL group and MI group .The rats in TXL group was administrated with TXL (2 g? kg-1? d-1, intragastric administration) for 4 weeks, while normal saline was applied to the rats in sham group and MI group.The levels of interleukin-1β(IL-1β) and endothelin-1 (ET-1) in the tissue from the border zone were measured by ELISA after treatment .The distribution and the mRNA and protein expression of Cx 43 were detected by immunohisto-chemical staining , RT-PCR and Western blotting , respectively .The burst pacing was used to induce ventricular arrhythmia ( VA) .RESULTS:Compared with sham group , the levels of IL-1βand ET-1 and the incidence of VA were significantly increased , while the mRNA and protein expression of Cx 43 was markedly reduced with irregular distribution in MI group (P<0.05).Compared with MI group, the levels of IL-1βand ET-1 and the incidence of VA were significantly reduced , while the expression of Cx 43 at mRNA and protein levels was markedly increased with augmented linear distribution in the myocardial cell intercalated disc in TXL group (P<0.05).CONCLUSION:TXL reduces the incidence of VA after MI via inhibiting the Cx43 remodeling .

OBJECTIVETo explore the prevalence and the different risk factors for asthma in children between urban and rural areas in Fuzhou, Fujian province.

METHODThe epidemiological survey of asthma in 0-14 years old children was conducted from October 2009 to October 2010 between Fuzhou urban and rural areas in Fujian province. The investigation subjects were selected in urban and rural areas by phased stratified random cluster sampling. The 2010 third national epidemiological survey questionnaire of children with asthma was used for screening for possible patients. Diagnosis of asthma was confirmed by physical examination. The children with asthma were designated as the positive cases, while non asthmatic children who were age, gender, ethnic, and living environment matched with asthmatic patients were designated as negative control. Comparison of the prevalence of asthma in children between Fuzhou urban and rural areas was performed. The influencing factors of asthma were analyzed and screened by the regression equation model of two element Logistic regression.

RESULTTotally 12 235 questionnaires of children with asthma and allergic disease screening were issued and 11 738 questionnaire were sent back (6 221 were male and 5 517 were female). The return rate was 95.9% in urban Fuzhou; 648 children were diagnosed as asthma. The prevalence of asthma in male was 6.48% and female children was 4.44% (comparison of the prevalence of gender χ(2) = 23.267, P < 0.001) in urban areas . A total of 6 000 questionnaires of children with asthma and allergic disease screening were sent out and 5 860 were responded (male children 3 228, female children 2 632). The recovery rate was 97.7% in rural Fuzhou; 135 children with asthma was diagnosed. The prevalence of asthma in male was 2.73%and female children and was 1.79%. Adding protein supplement before 6 months (OR = 1.908, 95%CI:1.233-2.959), the use of antibiotics in the treatment of asthma (OR = 14.541, 95%CI:8.920-23.705), furniture materials (non wood) (OR = 2.432, 95%CI:1.563-3.785) were the main risk factors of children with asthma in urban. Adding protein supplement before 6 months(OR = 3.021, 95%CI:1.357-6.711), the use of antibiotics in the treatment of asthma(OR = 14.784, 95%CI:3.842-56.885), the use of coal as fuel (OR = 63.339, 95% CI: 7.993-501.943), domesticated livestock (OR = 13.659, 95% CI:1.342-139.068), the family smoking before and after birth (OR = 6.226, 95%CI:2.674-14.495) and chemical fiber pillow (OR = 3.638, 95%CI:1.241-10.666) were the main risk factors of children with asthma in rural areas.

CONCLUSIONThe prevalence of children with asthma in urban areas was higher than that in rural areas. The prevalence of asthma in male children was higher than in female children. Adding protein food supplement before 6 months, the use of antibiotics and non solid wood furniture material were the main risk factors in children with asthma in urban areas. Adding protein supplement before 6 months, the use of antibiotics, domesticated livestock, the use of coal as fuel and the family smoking before and after birth were the main risk factor of asthma in children in rural areas.

Adolescent ; Anti-Bacterial Agents ; administration & dosage ; adverse effects ; Asthma ; epidemiology ; etiology ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Logistic Models ; Male ; Prevalence ; Risk Factors ; Rural Population ; statistics & numerical data ; Sampling Studies ; Smoking ; adverse effects ; Surveys and Questionnaires ; Urban Population ; statistics & numerical data