[Bioretention Media Screening for the Removal of Phosphorus in Urban Stormwater].

Urban runoff is an increasingly important source of excess phosphorus (P) to local receiving waters. Bioretention, a promising technology for urban stormwater pollution treatment, was investigated to determine whether the mixture of purple soil and sand could adsorb sufficient P at low concentrations in urban stormwater. The TP concentrations of urban runoff from variously impervious areas in Chongqing City ranged from 0. 04 to 7. 00 mg . L-1 (mean ± S. D. = 0. 75 mg . L-1 ± 1. 08 mg . L-1); the TDP concentrations ranged from 0. 02-0. 46 mg . L-1 ( mean ± S. D. = 0. 15 mg . L-1 ± 0. 10 mg . L-1). The media adsorption benchmark was determined for a bioretention facility sized at 10% of the 100% impervious catchment area and having 10 years of capacity according to annual rainfall pattern and the runoff TDP range. The media benchmark for adsorption was calculated as 7. 5 mg . kg-1 at soluble P concentration of 0. 30 mg . L-1 which provided the necessary stormwater treatment. The oxalate-extractable aluminum and iron content influenced the P sorption capacity for neutral and acid purple soils. A strong positive linear relationship was observed between the oxalate ratio [OR = (Alox + Feox)/Pox] and media P sorption capacity. The media mixture of 20% purple soil and 80% sand showed excellent P removal, meeting the developed benchmark for adsorptive behavior. The media mixture in a large-scale (60 cm) column consistently produced soluble reactive phosphorus effluent event with mean concentrations <0. 05 mg . L-1. The media mixture of purple soil and sand can be used as a bioretention media to treat low-concentration phosphorus in urban runoff under various hydrologic and pollutant concentration conditions.

Impact of adjuvant chemotherapy cycles on prognosis of resectable stomach cancer: a retrospective analysis.

AIMS: The aim of this study was to investigate the effects of adjuvant chemotherapy cycles on the prognosis of patients with post-operative stomach cancer through retrospective analysis. METHODS: A total of 128 patients with gastric cancer who underwent gastrectomy, followed by adjuvant chemotherapy consisting of epirubicin, cisplatin or oxaliplatin, leucovorin, and 5-fluorouracil, according to a defined schedule, were divided into three groups according to the number of chemotherapy cycles: Group I (<6 cycles); Group II (6 cycles); and Group III (>6 cycles). RESULTS: The 5-year overall survival (OS) was 20.8% in Group I, 45.0% in Group II, and 42.9% in Group III, with a median follow-up of 43 months. The 5-year relapse-free survival (RFS) was 15.1% in Group I, 40% in Group II, and 40% in Group III. The OS and RFS in Groups II and III were significantly better than in Group I (OS, p = 0.002 and p=0.003; RFS, P<0.001 and P=0.002). There was no difference in OS (p = 0.970) or in RFS (p = 0.722) between Groups II and III. Multivariate Cox hazard analysis determined that the number of adjuvant chemotherapy cycles was an independent factor that influenced OS and RFS. CONCLUSION: Six cycles of adjuvant chemotherapy gave encouraging outcomes in patients with resectable gastric cancer. Further prospective randomized controlled investigations are warranted in a multi-center setting.

Adjuvant probiotics improve the eradication effect of triple therapy for Helicobacter pylori infection.

AIM: To investigate whether the addition of probiotics can improve the eradication effect of triple therapy for Helicobacter pylori (H. pylori) infection. METHODS: This open randomized trial recruited 234 H. pylori positive gastritis patients from seven local centers. The patients were randomized to one-week standard triple therapy (omeprazole 20 mg bid, clarithromycin 500 mg bid, and amoxicillin 1000 mg bid; OCA group, n = 79); two weeks of pre-treatment with probiotics, containing 3 × 10(7)Lactobacillus acidophilus per day, prior to one week of triple therapy (POCA group, n = 78); or one week of triple therapy followed by two weeks of the same probiotics (OCAP group, n = 77). Successful eradication was defined as a negative C13 or C14 urease breath test four weeks after triple therapy. Patients were asked to report associated symptoms at baseline and during follow-up, and side effects related to therapy were recorded. Data were analyzed by both intention-to-treat (ITT) and per-protocol (PP) methods. RESULTS: PP analysis involved 228 patients, 78 in the OCA, 76 in the POCA and 74 in the OCAP group. Successful eradication was observed in 171 patients; by PP analysis, the eradication rates were significantly higher (P = 0.007 each) in the POCA (62/76; 81.6%, 95% CI 72.8%-90.4%) and OCAP (61/74; 82.4%, 95% CI 73.6%-91.2%) groups than in the OCA group (48/78; 61.5%, 95% CI 50.6%-72.4%). ITT analysis also showed that eradication rates were significantly higher in the POCA (62/78; 79.5%, 95% CI 70.4%-88.6%) and OCAP (61/77; 79.2%, 95% CI 70%-88.4%) groups than in the OCA group (48/79; 60.8%, 95% CI 49.9%-71.7%), (P = 0.014 and P = 0.015). The symptom relieving rates in the POCA, OCAP and OCA groups were 85.5%, 89.2% and 87.2%, respectively. Only one of the 228 patients experienced an adverse reaction. CONCLUSION: Administration of probiotics before or after standard triple therapy may improve H. pylori eradication rates.

Gastro-protecting effect of gefarnate on chronic erosive gastritis with dyspeptic symptoms.

BACKGROUND: The role of gastro-protecting agents on symptomatic chronic gastritis is unclear. This multicenter, open, randomized trial was designed to compare the comprehensive effects of gefarnate with sucralfate on erosive gastritis with dyspeptic symptoms. METHODS: Totally 253 dyspepsia patients confirmed with erosive gastritis were enrolled from six centers in China. They randomly received either daily 300 mg gefarnate or 3 g sucralfate for six weeks. The primary endpoint was the effective rate of both treatments on endoscopic erosion at week six. RESULTS: Gefarnate showed an effective rate of 72% and 67% on endoscopic score and dyspeptic symptom release, which is statistically higher than sucralfate (40.1% and 39.3%, P < 0.001, intension-to-treat). For histological improvement, gefarnate showed both effective in decreasing mucosal chronic inflammation (57.7% vs. 24.8%, P < 0.001, intension-to-treat) and active inflammation (36.4% vs. 23.1%, P < 0.05, intension-to-treat) than the control. A significant increase of prostaglandins and decrease of myeloperoxidase in mucosa were observed in gefarnate group. Severity of erosion is non-relevant to symptoms but Helicobacter pylori (H. pylori) status does affect the outcome of therapy. CONCLUSIONS: Gefarnate demonstrates an effective outcome on the mucosal inflammation in patients with chronic erosive gastritis. Endoscopic and inflammation score should be the major indexes used in gastritis-related trials.

Differential signature of fecal microRNAs in patients with pancreatic cancer.

The potential value of microRNAs as new biomarkers for pancreatic cancer (PCa) screening was explored in this study. Fecal microRNAs from stool samples obtained from 29 PCa patients, 22 chronic pancreatitis (CP) patients and 13 normal individuals were extracted, and 7 microRNAs (miR-16, miR-21, miR-155, miR-181a, miR-181b, miR-196a and miR-210) were detected. miR-181b and miR-210 discriminated PCa from normal individuals with receiver operating characteristic (ROC) curves and area under curve (AUC-ROC) of 0.745 and 0.772, respectively. There was a significant correlation between miR­196a and the maximum tumor diameter (Spearman r = 0.516, P = 0.041). These findings suggest that fecal microRNAs such as miR-181b and miR-210 may have potential to be used as new biomarkers for PCa screening.

Inhibitory effects of intravenous lansoprazole 30 mg and pantoprazole 40 mg twice daily on intragastric acidity in healthy Chinese volunteers: a randomized, open-labeled, two-way crossover study.

BACKGROUND: Until now there has been no study that directly compares the effect of lansoprazole and pantoprazole administered intravenously on intragastric acidity. The aim of this study is to compare the effect of lansoprazole (30 mg) and pantoprazole (40 mg) administered intravenously on gastric acidity. MATERIAL/METHODS: Helicobacter pylori-negative healthy volunteers were recruited in this open-label, randomized, two-way crossover, single centre study. Lansoprazole at 30 mg or pantoprazole at 40 mg was intravenously administered twice daily for 5 consecutive days with at least a 14-day washout interval. Twenty-four-hour intragastric pH was continuously monitored on days 1 and 5 of each dosing period. RESULTS: Twenty-five volunteers completed the 2 dosing periods. The mean intragastric pH values were higher in subjects treated with lansoprazole than those with pantoprazole on both day 1 (6.41 ± 0.14 vs. 5.49 ± 0.13, P=0.0003) and day 5 (7.09 ± 0.07 vs. 6.64 ± 0.07, P=0.0002). Significantly higher percentages of time with intragastric pH >4 and pH >6 were found in the subjects treated with lansoprazole than those with pantoprazole on day 1 (pH >4, 87.12 ± 4.55% vs. 62.28 ± 4.15%, P=0.0012; pH >6, 62.12 ± 4.12% vs. 47.25 ± 3.76%, P=0.0216) and pH >6 on day 5 (76.79 ± 3.77% vs. 58.20 ± 3.77%, P=0.0025). CONCLUSIONS: Intravenous lansoprazole produces a longer and more potent inhibitory effect on intragastric acidity than does intravenous pantoprazole.

Acid inhibition effect of ilaprazole on Helicobacter pylori-negative healthy volunteers: an open randomized cross-over study.

OBJECTIVE: The aim of this study was to evaluate the effects and safety of different doses of ilaprazole on healthy volunteers without a Helicobacter pylori infection. METHODS: A total of 12 healthy Chinese volunteers were enrolled and divided into four groups randomly, with a 5-day treatment of oral ilaprazole 5mg, 10mg and 20mg or omeprazole 20mg, respectively. After an interval of a 14-day washout phase, each was switched to another dose group and eventually completed all four regimens. The percentage time of intragastric pH>4 was the major index. The polymorphisms of the metabolic enzyme CYP2C19 in these volunteers were also detected. RESULTS: The percentage time of intragastric pH>4 in the ilaprazole 5, 10 and 20mg groups were 80.4%, 88.1% and 91.0%, respectively, during the first 24h, compared to that of the 20mg omeprazole group (76.6%, P>0.05). Ilaprazole 20mg provided a significant higher mean 24-h pH than that of the same dose of omeprazole both on Day 1 (7.78 vs 6.67, P<0.01) and Day 5 (7.95 vs 7.44, P<0.05). No CYP2C19-dependent difference or obvious adverse effect were found in any ilaprazole groups. CONCLUSION: Low dose ilaprazole offers a gastric acid inhibition comparable to a routine dose of omeprazole, and further investigations in patients with acid-associated diseases are needed.

Soluble triggering receptor expressed on myeloid cells in severe acute pancreatitis: a biological marker of infected necrosis.

PURPOSE: The diagnosis and treatment of secondary infection of pancreatic necrotic tissue remain a major challenge. The level of soluble triggering receptor expressed on myeloid cells (sTREM-1) in fine needle aspiration (FNA) fluid may be a good marker of infected necrosis. METHODS: Patients with a clinical suspicion of secondary infection of necrotic tissue were enrolled. The serum levels of C-reactive protein, amylase, procalcitonin (PCT), and sTREM-1 and the fluid levels of sTREM-1, PCT, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and amylase were examined. When infected necrosis was defined, the first step was percutaneous or endoscopic drainage. If there was no improvement after 72 h, an open necrosectomy was performed. RESULTS: In 30 patients with suspected infection, 18 patients were diagnosed as having secondary infection of necrotic tissue. The levels of sTREM-1 and PCT in FNA fluid were found to have the closest correlation with the diagnosis of infected necrosis [sTREM-1: area under the receiver operating characteristic curve (AUC) 0.972; 95% confidence interval (95%CI) 0.837-1.000; PCT: AUC 0.903; 95%CI 0.670-0.990, P > 0.05]. A fluid sTREM-1 cutoff value of 285.6 pg/ml had a sensitivity of 94.4% and a specificity of 91.7%. In a multiple logistic regression analysis, an sTREM-1 level of more than 285 pg/ml and a PCT level of more than 2.0 ng/ml in FNA fluid were independent predictors of infected necrosis. CONCLUSIONS: The fluid level of sTREM-1 will help in the rapid and accurate diagnosis of secondary infection of necrotic tissue in patients with severe acute pancreatitis (SAP).

Comparison of antioxidative and antifibrotic effects of α-tocopherol with those of tocotrienol-rich fraction in a rat model of chronic pancreatitis.

OBJECTIVES: The α-tocopherol and tocotrienol-rich fraction (TRF) are considered effective antioxidants. This study aimed to compare the antioxidative and antifibrotic effects of α-tocopherol and TFR in dibutylin dichloride (DBTC)-induced chronic pancreatitis (CP) rats. METHODS: Oral administration of α-tocopherol and TFR (both 800 mg/kg per day) started the next day after DBTC (8 mg/kg) infusion into the tail vein for 4 weeks. Histological examination, Sirius red staining, and measurement of the contents of hydroxyproline and malondialdehyde of the pancreas were performed to evaluate pancreatic damage and fibrosis. Immunohistochemical analysis of α-smooth muscle actin and real-time reverse transcription polymerase chain reaction for transforming growth factor-ß1 (TGF-ß1) and collagen-α1(I) were performed to evaluate the activation of pancreatic stellate cells and the mRNA levels of fibrosis-related genes, respectively. RESULTS: Both α-tocopherol and TRF reduced oxidative stress, ameliorated inflammation and fibrosis, and down-regulated the mRNA expression of TGF-ß1 and collagen-α1(I) in DBTC-induced CP. The TRF was superior to α-tocopherol in alleviating inflammation and fibrosis and down-regulating TGF-ß1 mRNA expression. CONCLUSIONS: Oral administration of α-tocopherol and TRF improves pancreatic inflammation and fibrosis in DBTC-induced CP rats, with TRF being more effective than α-tocopherol. Therefore, TRF may be a novel option for alleviating inflammation and, particularly, the fibrotic process in CP.

An experimental study of betadine irrigation for preventing infection during the natural orifice transluminal endoscopic surgery (NOTES) procedure.

OBJECTIVE: To study the effect and feasibility of using betadine irrigation of the gastrointestinal tract for preventing infection during the natural orifice transluminal endoscopic surgery (NOTES) procedure. METHODS: Twelve sows were used in this study. Four sows in the control group were lavaged with 500 mL saline. The eight sows in the experimental group were first lavaged with 500 mL saline and then irrigated with 200 mL betadine. A total of 5 mL of gastrointestinal (GI) tract fluid was collected before and after lavage, respectively, and 5 mL of peritoneal fluid was collected at the end of the NOTES procedure. A follow-up endoscopic examination of the GI tract was performed 24 h after NOTES. The animals were killed and necropsied after 3 weeks. RESULTS: Irrigation with betadine of the GI tract significantly reduced the bacterial load of GI fluid. One sow died of diaphragmatic injury. No inflammation, ulcer or bleeding were observed in the experimental group by endoscopy after 24 h. More adhesions and abscesses were found in the control group than in the experimental group after 3 weeks. Only one case of adhesion was observed in the experimental group using the transcolonic approach. CONCLUSIONS: Betadine irrigation of the GI tract is effective and feasible for preventing infection during the NOTES procedure. Further studies are needed for assessing the effectiveness and safety of betadine irrigation in the clinical application of NOTES.

Continuous and low-energy 125I seed irradiation changes DNA methyltransferases expression patterns and inhibits pancreatic cancer tumor growth.

BACKGROUND: Iodine 125 (125I) seed irradiation is an effective treatment for unresectable pancreatic cancers. However, the radiobiological mechanisms underlying brachytherapy remain unclear. Therefore, we investigated the influence of continuous and low-energy 125I irradiation on apoptosis, expression of DNA methyltransferases (DNMTs) and cell growth in pancreatic cancers. MATERIALS AND METHODS: For in vitro 125I seed irradiation, SW-1990 cells were divided into three groups: control (0 Gy), 2 Gy, and 4 Gy. To create an animal model of pancreatic cancer, the SW 1990 cells were surgically implanted into the mouse pancreas. At 10 d post-implantation, the 30 mice with pancreatic cancer underwent 125I seed implantation and were separated into three groups: 0 Gy, 2 Gy, and 4 Gy group. At 48 or 72 h after irradiation, apoptosis was detected by flow cytometry; changes in DNMTs mRNA and protein expression were assessed by real-time PCR and western blotting analysis, respectively. At 28 d after 125I seed implantation, in vivo apoptosis was evaluated with TUNEL staining, while DNMTs protein expression was detected with immunohistochemical staining. The tumor volume was measured 0 and 28 d after 125I seed implantation. RESULTS: 125I seed irradiation induced significant apoptosis, especially at 4 Gy. DNMT1 and DNMT3b mRNA and protein expression were substantially higher in the 2 Gy group than in the control group. Conversely, the 4 Gy cell group exhibited significantly decreased DNMT3b mRNA and protein expression relative to the control group. There were substantially more TUNEL positive in the 125I seed implantation treatment group than in the control group, especially at 4 Gy. The 4 Gy seed implantation group showed weaker staining for DNMT1 and DNMT3b protein relative to the control group. Consequently, 125I seed implantation inhibited cancer growth and reduced cancer volume. CONCLUSION: 125I seed implantation kills pancreatic cancer cells, especially at 4 Gy. 125I-induced apoptosis and changes in DNMT1 and DNMT3b expression suggest potential mechanisms underlying effective brachytherapy.

Plasma miR-216a as a potential marker of pancreatic injury in a rat model of acute pancreatitis.

AIM: To study the potential value and specificity of plasma miR-216a as a marker for pancreatic injury. METHODS: Two rat models were applied in this article: L-arginine-induced acute pancreatitis was used as one model to explore the potential value of plasma miR-216a for detection of pancreatic injury; nonlethal sepsis induced in rats by single puncture cecal ligation and puncture (CLP) was used as the other model to evaluate the specificity of plasma miR-216a compared with two commonly used markers (amylase and lipase) for acute pancreatitis. Plasmas were sampled from rats at indicated time points and total RNA was isolated. Real-Time Quantitative reverse transcriptase-polymerase chain reaction was used to quantify miR-216a in plasmas. RESULTS: In the acute pancreatitis model, among five time points at which plasmas were sampled, miR-216a concentrations were significantly elevated 24 h after arginine administration and remained significantly increased until 48 h after operation (compared with 0 h time point, P < 0.01, Kruskal-Wallis Test). In the CLP model, plasma amylase and lipase, two commonly used biomarkers for acute pancreatitis, were significantly elevated 24 h after operation (compared with 0 h time point, P < 0.01 and 0.05 respectively, Pairwise Bonferroni corrected t-tests), while miR-216a remained undetectable among four tested time points. CONCLUSION: Our article showed for the first time that plasma miR-216a might serve as a candidate marker of pancreatic injury with novel specificity.

Upregulated histone deacetylase 1 expression in pancreatic ductal adenocarcinoma and specific siRNA inhibits the growth of cancer cells.

OBJECTIVES: So far, there are no investigations about the role of histone deacetylase 1 (HDAC1) in tumorigenesis of pancreatic ductal adenocarcinoma. This study was designed to elucidate the roles and mechanisms of HDAC1 in tumorigenesis of pancreatic ductal adenocarcinoma. METHODS: Real-time reverse transcription-polymerase chain reaction and immunohistochemistry techniques were adopted to detect the expression of HDAC1 in human pancreatic ductal adenocarcinoma tissues and paired paracancerous tissues. The roles of HDAC1 in human pancreatic cell line PaTu8988 were investigated using siRNA. RESULTS: Histone deacetylase 1 mRNA in pancreatic cancer tissues were significantly higher than in paracancerous tissues (P < 0.05). Immunohistochemistry showed that the indices of HDAC1 in pancreatic cancer tissues and paracancerous tissues were 56.4% (SD, 23.1%) and 6.7% (SD, 5.0%), respectively (P < 0.001). Knockdown of HDAC1 can generate a remarkable defect in proliferation and also can significantly induce apoptosis and S-phase arrest in PaTu8988 cells (P < 0.05). The Bcl-2 mRNA expression was significantly downregulated, whereas the p21 and Bax mRNA expression were significantly upregulated. CONCLUSIONS: The HDAC1 overexpression might play an important role in tumorigenesis of pancreatic cancer. Our data support the development of selective inhibitors targeting HDAC1 for the treatment of pancreatic ductal adenocarcinoma. Histone deacetylase 1 could be a new gene therapy target in pancreatic ductal adenocarcinoma.

Reduction of pancreatic cancer cell viability and induction of apoptosis mediated by siRNA targeting DNMT1 through suppression of total DNA methyltransferase activity.

Aberrant methylation leads to epigenetic changes in human genes that may cause carcinogenesis. DNA methyltransferase 1 (DNMT1) plays an important role in maintaining DNA methylation patterns during genomic DNA replication. To understand the role of this protein in pancreatic cancer cell growth and apoptosis, small interfering RNA (siRNA) oligonucleotides were used to knockdown DNMT1 expression in pancreatic cancer PaTu8988 cells. We found that the DNMT1 siRNA markedly decreased DNMT1 expression and total DNA methyltransferase activity in the cells. Upon the inhibition of DNMT1 expression, the proliferation of the tumor cells was inhibited. Tumor cell growth was arrested in the S-phase of the cell cycle and cells underwent apoptosis. The expression of p21 was up-regulated and the ratio of Bax/Bcl-2 expression was increased after DNMT1 knockdown in PaTu8988 cells. Furthermore, DNMT1 siRNA caused demethylation of the tumor suppressor gene hMLH1, resulting in its re-expression in PaTu8988 cells. The results of this study suggest that DNMT1 siRNA oligonucleotides are candidates for further evaluation as therapeutic tools for the clinical control of pancreatic cancer.

Significance of DNA methyltransferase-1 and histone deacetylase-1 in pancreatic cancer.

Epigenetic modifications play an important role during carcinogenesis. The main goal of this study was to examine expression levels of two critical enzymes, DNA methyltransferase-1 (DNMT1) and histone deacetylase-1 (HDAC1), by immunohistochemistry (IHC) in human pancreatic cancer and precancerous lesions: 20 foci containing normal ductal epithelial cells without an inflammatory back-ground (DE), 30 containing ductal epithelial cells with an inflammatory background (DEI), 48 of pancreatic intraepithelial neoplasia-1A (PanIN-1A), 103 of PanIN-1B, 99 of PanIN-2, 30 of PanIN-3, 18 of intraductal papillary mucinous neoplasm A (IPMA), 10 of IPMB, 20 of IPMC, and 54 of pancreatic ductal adenocarcinoma (PDAC). The expression levels of both DNMT1 and HDAC1 increased from normal to precancerous lesions to pancreatic cancer, in a malignancy-dependent manner. Correlations between expression levels and clinicopathological features of the 54 PDAC patients were also analyzed. The expression of DNMT1 significantly correlated with nerve infiltration, degree of tumor differentiation and TNM staging (p<0.05), while that of HDAC1 correlated with proliferative activity, degree of tumor differentiation and TNM staging (p<0.05). Patients with higher expression of DNMT1 and/or HDAC1 had an overall lower survival than those with lower expression (p<0.05). Higher expression of DNMT1 and HDAC1 correlated with advanced stages of the disease and reflect the malignancy of pancreatic carcinoma. They may become new prognostic markers and potential therapeutic targets for pancreatic cancer.

A novel approach for treatment of unresectable extrahepatic bile duct carcinoma: design of radioactive stents and an experimental trial in healthy pigs.

BACKGROUND: Patients diagnosed with extrahepatic bile duct carcinoma (EBDC) have a poor prognosis. OBJECTIVE: The purpose of these studies was to design radioactive stents for EBDC and to evaluate the feasibility and safety of the stents in healthy pigs. DESIGN: Plastic stents with inserted iodine-125 seeds were designed and tested in 11 healthy pigs. The pigs were divided into 4 groups on the basis of radiation doses. INTERVENTIONS: The stents with estimated radiation dose at a 5-mm radial distance from the axis of the seeds of 30 Gy, 60 Gy, and 90 Gy were implanted in the common bile duct (CBD) in groups A, B, and C (n = 3 in each group), with the control group (n = 2) being implanted with the stents containing nonradioactive seeds. MAIN OUTCOME MEASUREMENTS: Histologic evaluation was performed under a light microscope. RESULTS: The procedures were successfully performed on all pigs. Severe hyperplasia of the mucosa was seen in the control group. In the experimental groups, obvious mucosal necrosis near the radioactive seeds was observed but without perforation of the CBD wall. In lower-dose groups (30 Gy), mild hyperplasia of mucosal glands with fibrosis under the necrosis layer was seen. However, after the increase of the dose, mucosal glands were disappearing without a visible mucosal layer. CONCLUSIONS: The radioactive stents are safe at each dose in healthy pigs. Moreover, our observations indicate the feasibility to design specific radioactive stents according to the size, shape, and position of EBDC in future clinical applications.

[An experiment of 125I radioactive pancreatic duct stents implanted in the pancreatic ducts of pigs].

OBJECTIVE: To evaluate the feasibility and safety of radioactive pancreatic duct stents implanted in the pancreatic ducts of pigs by endoscopy. METHODS: Different doses of 125I radioactive pancreatic duct stents were implanted in the pancreatic ducts of pigs by endoscopy. Blood tests were conducted before and after implantation. 14, 30 and 60 days after implantation of the radioactive stents, the pigs were euthanized in batch. All animals underwent post mortem examination to exclude intra-abdominal hemorrhage, pancreatic fistula or peritonitis. During autopsy, the liver, bile ducts, head of the pancreas, stomach and duodenum were examined for perforation, stricture or dilation and damage of the surrounding structures. RESULTS: Fourteen pigs were implanted with pancreatic duct stents by endoscopic procedures. There was no effusion, hemorrhage or necrosis in the adjacent duodenum, stomach, liver or right kidney. The normal morphological structures of the duct of Wirsung disappeared in all the treated pigs. Histopathological examination revealed that the stents were surrounded by necrotic tissue and outside fibrous tissue. During the follow-up period, the width of outside fibrous tissue gradually increased. There were no serious abnormalities noted in the blood tests after implantation. CONCLUSION: It is indicated that the radioactive stents are safe in all the different dose groups. For future clinical application, it is feasible to design a special radioactive stent for each patient according to the size, shape and position of the pancreatic tumor.

[mRNA expression of GLI1 in pancreatic carcinoma and clinical significance thereof].

OBJECTIVE: To investigate the mRNA expression of GLI1, a transcription regulator of Hedgehog signaling pathway, in human pancreatic carcinoma and to explore its clinical significance. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GLI1 in the tumor tissues, tissues near tumor, and normal tissues obtained during operation from 25 pancreatic carcinoma patients. RESULTS: The GLI1 mRNA expression rate of the tumor tissues was 68.0% (17/25), significantly higher than those of the tissues near tumor, and normal tissues [24.0% (6/25) and 0 (0/25) respectively, both P < 0.01]. The GLI1 mRNA expression rate was significantly associated with the differentiation degree of tumor tissue (P = 0.014), and not significantly associated with the tumor size, invasion, and metastasis (all P > 0.05). CONCLUSION: GLI1 mRNA expression is strong in pancreatic carcinoma tissues and is significantly associated with the differentiation degree of tumor tissue. With diagnostic implication, GLI1 mRNA expression may be regarded as a parameter of determining the degree of malignancy and prognosis of pancreatic carcinoma.

A novel approach for treatment of unresectable pancreatic cancer: design of radioactive stents and trial studies on normal pigs.

PURPOSE: Patients diagnosed with pancreatic cancer typically have a poor prognosis. The aims of these studies were to design radioactive stents and to evaluate the feasibility and safety of the stents in animals. EXPERIMENTAL DESIGN: To combine the effects of stents and brachytherapy, plastic stents with inserted iodine-125 seeds were designed and tested in 18 normal pigs. The pigs were divided into five groups on the basis of radiation dose. The estimated radiation dose at a 5-mm radial distance from the axis of the seeds was 50 Gy in group A, 100 Gy in group B, 150 Gy in group C, and 200 Gy in group D, with four pigs in each group. In the control group (n = 2), the same plastic stents with non-radioactive seeds were implanted in the pancreatic duct. RESULTS: The procedures were successfully done on 14 of 18 (78%) pigs, whereas pancreatic duct perforation occurred in four pigs (22%). The thickened wall of the dilated pancreatic duct was clearly observed in the control group. However, the normal morphologic structure of the pancreatic duct wall disappeared in the experimental groups. Histopathologic examination revealed that the stents were surrounded with necrotic tissues and lateral fibrous tissues. During the follow-up period, the width of outside fibrous tissues gradually increased. CONCLUSIONS: These results indicate that the radioactive stents are safe in all dose groups, and it is feasible to design a special radioactive stent for each patient according to the size, shape, and position of the pancreatic tumor.

Construction of recombinant attenuated Salmonella typhimurium DNA vaccine expressing H pylori ureB and IL-2.

AIM: To construct a recombinant live attenuated Salmonella typhimurium DNA vaccine encoding H pylori ureB gene and mouse IL-2 gene and to detect its immunogenicity in vitro and in vivo. METHODS: H pylori ureB and mouse IL-2 gene fragments were amplified by polymerase chain reaction (PCR) and cloned into pUCmT vector. DNA sequence of the amplified ureB and IL-2 genes was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions resulting in pIRES-ureB and pIRES-ureB-IL-2. The recombinant plasmids were used to transform competent E. coli DH5alpha, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-ureB and pIRES-ureB-IL-2 were used to transform LB5000 and the recombinant plasmids extracted from LB5000 were finally introduced into the final host SL7207. After that, recombinant strains were grown in vitro repeatedly. In order to detect the immunogenicity of the vaccine in vitro, pIRES-ureB and pIRES-ureB-IL-2 were transfected to COS-7 cells using Lipofectamine 2000, the immunogenicity of expressed UreB and IL-2 proteins was assayed with SDS-PAGE and Western blot. C57BL/6 mice were orally immunized with 1 x 10(8) recombinant attenuated Salmonella typhimurium DNA vaccine. Four weeks after vaccination, mice were challenged with 1 x 10(7) CFU of live H pylori SS1. Mice were sacrificed and the stomach was isolated for examination of H pylori 4 wk post-challenge. RESULTS: The 1700 base pair ureB gene fragment amplified from the genomic DNA was consistent with the sequence of H pylori ureB by sequence analysis. The amplified 510 base pair fragment was consistent with the sequence of mouse IL-2 in gene bank. It was confirmed by PCR and restriction enzyme digestion that H pylori ureB and mouse IL-2 genes were inserted into the eukaryotic expression vector pIRES. The experiments in vitro showed that stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying ureB and IL-2 genes was successfully constructed and the specific strips of UreB and IL-2 expressed by recombinant plasmids were detected through Western blot. Study in vivo showed that the positive rate of rapid urease test of the immunized group including ureB and ureB-IL-2 was 37.5% and 12.5% respectively, and was significantly lower than that (100%) in the control group (P<0.01). CONCLUSION: Recombinant attenuated Salmonella typhimurium DNA vaccine expressing UreB protein and IL-2 protein with immunogenicity can be constructed. It can protect mice against H pylori infection, which may help the development of a human-use H pylori DNA vaccine.