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Xin-Yu Qin

Publications and source records attributed to Xin-Yu Qin.

10 recordsLinked to original sources
PubMed2006

Regulated production of mature insulin in rat hepatoma cells: insulin production is up-regulated by dexamethasone and down-regulated by insulin.

We engineered an artificial beta cell line that produces an up-regulation of insulin in response to dexamethasone, and a down-regulation in response to insulin. A regulatory secretion system was devised by placing proinsulin cDNA containing genetically engineered furin endoprotease cleavage sites and a regulatory promoter for phosphoenolpyruvate carboxykinase (PEPCK), and an insulin expressing retrovirus vector (pN-PEPCK-mINS) was constructed and transfected into Hepa1-6 cells. The levels of insulin in culture medium and expression of insulin gene was estimated by radioimmunoassay and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The clone (Hepa1-6/INS21), which secreted the highest level of insulin (10.79 microIU/106 cells per day), was selected for the regulation experiment. Compared with the non-treated Hepa1-6/INS21 cells, insulin production was augmented 3.6-fold by the addition of 10-7 M of dexamethasone. Addition of exogenous insulin to the culture medium decreased insulin mRNA expression remarkably on RT-PCR results, while dexamethasone increased insulin gene expression at the transcriptional level. The data indicated that genetically engineered Hepa1-6 cells could synthesize process and secrete insulin in a physiological manner.

Animals↗
PubMed2006

Application of needle-knife in difficult biliary cannulation for endoscopic retrograde cholangiopancreatography.

BACKGROUND: Getting directly into the common bile duct (CBD) is the most important step for successful therapeutic biliary endoscopy. In 5%-10% of cases, the CBD remains inaccessible, necessitating pre-cut papillotomy or fistulotomy with a needle-knife. The aim of this study was to assess the value of early application of the needle-knife in difficult biliary cannulation for endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Patients with failed biliary cannulation after 10 minutes or guide wire entering the pancreatic tube 3 times were randomly divided into group of needle-knife cut and group of persistent cannulation by standard techniques. The cannulation times, success rates and complication rates were compared between the two groups. RESULTS: A total of 948 therapeutic biliary ERCP procedures were performed between October 2004 and February 2006. Of 91 patients with difficult biliary cannulation, 43 patients underwent needle-knife cut: the cannulation success rate was 90.7%, the mean cannulation time was 5.6 minutes, and the complication rate was 9.3%. The other 48 patients underwent persistent cannulation by standard techniques: the cannulation success rate was 75%, the mean cannulation time was 10.2 minutes, and the complication rate was 14.6%. Significant differences were observed in cannulation success rate and cannulation time but in complication rate between the two groups. CONCLUSION: The early application of the needle-knife in difficult biliary cannulation is time-saving, safe and effective, with no increase in complication rate.

Aged↗
PubMed2004

Role of endoscopic miniprobe ultrasonography in diagnosis of submucosal tumor of large intestine.

AIM: To evaluate the role of miniprobe ultrasonography under colonoscope in the diagnosis of submucosal tumor of the large intestine, and to determine its imaging characteristics. METHODS: Thirty-five patients with submucosal tumors of the large intestine underwent miniprobe ultrasonography under colonoscope. The diagnostic results of miniprobe ultrasonography were compared with pathological findings of specimens by biopsy and surgical resection. RESULTS: Lipomas were visualized as hyperechoic homogeneous masses located in the submucosa with a distinct border. Leiomyomas were visualized as hypoechoic homogeneous mass originated from the muscularis propria. Leiomyosarcomas were shown with inhomogeneous echo and irregular border. Carcinoids were presented as submucosal hypoechoic masses with homogenous echo and distinct border. Lymphangiomas were shown as submocosal hypoechoic masses with cystic septal structures. Malignant lymphomas displayed as hypoechoic masses from mucosa to muscularis propria, while pneumatosis cystoids intestinalis originated from submucosa with a special sonic shadow. One large leiomyoma was misdiagnosed as leiomyosarcoma. CONCLUSION: Endoscopic miniprobe ultrasonography can provide precise information about the size, layer of origin, border of submucosal tumor of the large intestine and has a high accuracy in the diagnosis of submucosal tumor of the large intestine. Pre-operative miniprobe ultrasonography under colonoscope may play an important role in the choice of therapy for submucosal tumor of the large intestine.

Adult↗
PubMed2003

Effects of two methods of reconstruction of digestive tract after total gastrectomy on gastrointestinal motility in rats.

AIM: To compare the effects of Roux-en-Y and jejunum interposition reconstruction procedures after total gastrectomy on intestinal motility. METHODS: Fifty male Sprague-Dawley rats were randomly divided into 5 groups: the control group (C), the laparotomy group (L), the jejunal transection group (JT) where the jejunum was transected 10 cm distal from the Treitz ligament and anastomosed, the Roux-en-Y group (RY) and the jejunal interposition group (JI) after total gastrectomy. To evaluate intestinal transit, the animals were given 0.1 ml Evans Blue solution through an orogastric tube. The rats were executed by CO(2) inhalation 30 minutes later and the intestinal transmit was determined as the distance between the site of esophageojejunal anastomosis and the most distal site of small intestine colored with blue. RESULTS: One month after operation, the body weight of rats among JI and RY were almost identical (274.6+/-9.5 vs 270.4+/-10.6, P>0.05), but were significantly lighter than those of JT and L group. Four months after the operation, the body weight in the JI group increased compared to the preoperative level (345.2+/-15.7 g vs 299.5+/-8.3 g, P<0.01). However, the body weight of RY group decreased compared to preoperative (255.1+/-11.3 g vs 295.0+/-12.0 g, P<0.01). The difference was more significant at six months postoperative. Small bowel transmit time in RY was slower than that in JI group and C group (P<0.01). CONCLUSION: Changes of body weight and intestinal motility in JI group are less influenced than in RY group.

Anastomosis, Roux-en-Y↗
PubMed2003

Involvement of dopamine D3 and neuropeptide Y Y5 receptors in diabetic gastroparetic rats without response to erythromycin.

Erythromycin may accelerate gastric emptying in animals and human probably as an motilin agonist, but its prokinetic effects show obvious individual disparity. This study was to find the mechanism of this phenomenon. Microarray analysis was used to screen genes that might be involved in the response of diabetic gastroparesis rats to erythromycin. It was found that erythromycin accelerated gastric emptying of diabetic rats with great individual disparity. Through microarray analysis we screened differential expression genes that might be involved in the effect of erythromycin. Among 10 genes screened out, dopamine D3 receptor (DRD3) and neuropeptide Y Y5 receptor (NPYY5) genes were submitted to RT-PCR quantification and showed consistent results with microarray. It can be concluded that erythromycin promote gastric emptying of gastroparetic rats; DRD3 and NPYY5 may be involved in prokinetic action of erythromycin; and targets other than motilin receptor of erythromycin might exist as prokinetics.

Animals↗
PubMed2003

Endoscopic diagnosis and treatment of post-cholecystectomy syndrome.

OBJECTIVE: To assess the value of endoscopy in the etiological diagnosis and treatment of post- cholecystectomy syndrome (PCS). METHODS: 386 patients with PCS were given endoscopic retrograde cholangiopancreatography (ERCP). Having been made the etiology clear, patients with choledocholithiasis were subjected to endoscopic sphincterotomy (EST) or endoscopic papillary balloon dilatation (EPBD) to extract stones, those with papillary inflammatory stricture to EST or EPBD, those with papillary diverticulum and sphincter of Oddi dysfunction (SOD) to EPBD, those with papillary tumor and hepatobiliary tumor to endoscopic metal biliary endoprosthese (EMBE), and those with biliary stricture in the mid bile duct, purulent cholangitis, choledocholithiasis (stones not extracted one time) and bile leakage to endoscopic nose-biliary drainage (ENBD). RESULTS: ERCP was performed successfully in 371 patients (96.1%). No abnormalities were found endoscopically in 30 patients. In 243 patients with choledocholithiasis, 235 had stones removed after one to three times. Thirty-nine patients with papillary inflammatory stricture were successfully treated with EST or EPBD. Nine patients with papillary diverticulum which oppressed the papillary opening and 7 patients with SOD were also successfully treated with EPBD. In 16 patients with stricture in the mid bile duct, 11 showed improvement after ENBD. Six patients with papillary tumor and 5 patients with hepatobiliary stricture after EMBE showed significant alleviation of jaundice. Six patients with bile leakage caused by cholecystectomy received ENBD successfully, avoiding re-operation. Six patients developed gastroduodenal ulcer and 4 residual stones in the cholecystic duct. Complications occurred in 21 patients (5.7%). CONCLUSIONS: ERCP may detect the etiology of post-cholecystectomy syndrome at early stage, and therapeutic measures can be taken accordingly in clinical practice.

Adult↗
PubMed2003

Endoscopic biliary drainage for biliary obstruction.

OBJECTIVE: To improve the successful rate of endoscopic biliary drainage. METHODS: Three hundred and fifty-two patients with biliary obstruction were given biliary drainage via duodenoscope from January 1998 to December 2002. 258 patients received endoscopic naso-biliary drainage (ENBD), 51 endoscopic retrograde biliary drainage (ERBD), and 43 endoscopic metal biliary endoprothesis (EMBE). RESULTS: Of the 352 patients with biliary obstruction, 337 succeeded in drainage by endoscopy and 15 failed. Ten ENBD failed patients were handled successfully by readjustment of the site of the naso-biliary tube. In 3 ERBD failed patients, 2 were given plastic stents with appropriate length and got a fluent drainage. Percutaneous transhepatic biliary drainage (PTBD) was performed in one patient after failure of endoscopic management. In 2 patients with failed EMBE, one stent could not exceed the site of tumor stricture and one was obstructed by tumor implantation only one month after EMBE. Placement of another metallic stent and a plastic stent through the previous prothesis for each patient ensured a successful drainage. CONCLUSIONS: The effect of endoscopic biliary drainage for biliary obstruction is definite. Drainage failure can be avoided or remedied as early as possible by taking some active measures.

Adolescent↗
PubMed2002

Construction and preliminary screening of a human phage single-chain antibody library associated with gastric cancer.

BACKGROUND: The aim of this study was to construct a phage library of human single-chain antibodies associated with gastric cancer and screen such a library for CEA binding scFv. MATERIALS AND METHODS: The cDNA library of antibody variable regions was constructed using mRNA from metastatic lymph nodes or spleen of patients with stomach cancer by RT-PCR. These cDNA were assembled into a single-chain format and cloned into phagemid pCANTAB-5 and then transformed into Escherichia coli TG1. The scFv gene library was rescued by M13KO7 helper phage. CEA and the viable CEA-positive gastric cancer cell line MKN-28 were used to screen the phage antibody library. Indirect and tumor cell ELISA was used to determine the specificity of phage antibody. Fixed cell immunofluorescence and live cell FACS analysis were used to further characterize the binding of phage scFv. RESULTS: After transformation into E. coli TG1, 2.5 x 10(7) cfu/microg ampicillin-resistant clones grew. Sequences of those positive insert clones showed that the V(H) genes were derived from the V(H) III subgroup, while the V(L) genes belonged to the V(kappa) III subgroup. After four rounds of panning, the titer of eluted binding phage increased 135- to 158-fold and ELISA results showed that 20/95 clones can bind CEA and 47/95 clones can bind fixed tumor cells. Immunofluorescence and FACS analysis results showed that these phage scFv fragments could bind CEA-positive cells. CONCLUSIONS: We successfully constructed a human phage antibody library from lymph nodes of stomach cancer patients. Such kinds of library prove useful for generating tumor-antigen-specific human antibody fragments.

Amino Acid Sequence↗
PubMed2002

Establishment of an artificial beta-cell line expressing insulin under the control of doxycycline.

AIM: Artificial beta-cell lines may offer an abundant source of cells for the treatment of type I diabetes, but insulin secretion in beta-cells is tightly regulated in physiological conditions. The Tet-On system is a "gene switch" system, which can induce gene expression by administration of tetracycline (Tet) derivatives such as doxcycline (Dox). Using this system, we established 293 cells to an artificial cell line secreting insulin in response to stimulation by Dox. METHODS: The mutated proinsulin cDNA was obtained from plasmid pcDNA3.1/C-mINS by the polymerase chain reaction (PCR), and was inserted downstream from the promoter on the expression vector pTRE2, to construct a recombined expression vector pTRE2mINS. The promoter on pTRE2 consists of the tetracycline-response element and the CMV minimal promoter and is thus activated by the reverse tetracycline-controlled transactivator (rtTA) when Dox is administrated. pTRE2mINS and plasmid pTK-Hyg encoding hygromycin were co-transfected in the tet293 cells, which express rtTA stably. Following hygromycin screening, the survived cells expressing insulin were selected and enriched. Dox was used to control the expression of insulin in these cells. At the levels of mRNA and protein, the regulating effect of Dox in culture medium on the expression of proinsulin gene was estimated respectively with Northern blot, RT-PCR, and radioimmunoassay. RESULTS: From the 28 hygromycin-resistant cell strains, we selected one cell strain (tet293/Ins6) secreting insulin not only automatically, but in response to stimulation by Dox. The amount on insulin secretion was dependent on the Dox dose (0,10,100,200,400,800 and 1000 microg.L(-1)), the level of insulin secreted by the cells treated with Dox (1000 microg.L(-1)) was 241.0pU.d(-1).cell(-1) , which was 25-fold that of 9.7pU.d(-1).cell(-1) without Dox treatment. Northern blot analyses and RT-PCR further confirmed that the transcription of insulin gene had already been up-regulated after exposing tet293/Ins6 cells to Dox for 15 minutes, and was also induced in a dose-dependent manner. However, the concentration of insulin in the media did not increase significantly until 5 hours following the addition of Dox. CONCLUSION: Human proinsulin gene was transfected successfully and expressed efficiently in 293 cells, and the expression was modulated by tetracycline and its derivatives, improving the accuracy, safety, and reliability of gene therapy, suggesting that conditional establishment of artificial beta-cells may be a useful approach to develop cellular therapy for diabetes mellitus.

Cell Line↗