According to our in vitro profiling of both HEPG2 and HuH-7 cells, we expected the highest rate of proliferation and EMT-like changes between days

3 and 5 after heat treatment at 48˚C or 50˚C (Supporting Figs. 6 and 7). Therefore, 5 × 106 HEPG2 cells kept at 37˚C, or pretreated at 45˚C, 48˚C, or 50˚C, were SC implanted http://www.selleckchem.com/products/Romidepsin-FK228.html on day 3 after heating. Tumor formation and ETW were evaluated every 3 days, and at day 15 after implantation, all mice were sacrificed. ETW showed that HCC grew faster in the 48˚C and 50˚C groups than in the 37˚C group (Fig. 7A). No mice died before sacrifice, and absence of tumor growth was observed in 1 mouse each of the 37˚C and 45˚C groups (Supporting Table 4). Median tumor weight was 298, 202, 57.5, and 19.5 mg in the

50˚C, 48˚C, 45˚C, and 37˚C groups, respectively (Fig. 7B; Supporting Table 4). Western blotting in harvested tumors showed higher p-Erk/Erk (p42/p44) ratio in the 48˚C and 50˚C groups than in the 37˚C group (P < 0.05 and P < 0.05, respectively; Fig. 7C). However, no significant changes were detected in Shc and p-Shc expression among these four groups (data not shown). Ki-67 positivity was higher in the center than in the periphery of tumors (P < 0.05 for the 48˚C and 50˚C groups; Fig. 7D). Transcript levels of Ki67 and of the EMT markers, TWIST1 and COL1A1, were significantly elevated in the 50˚C group, compared to the 37˚C group (P < 0.05; Fig. 7E). Other EMT or stem-cell–related selleck transcripts showed no significant difference and a trend to

be increased at best. Using hematoxylin and eosin histology, there was no difference in necrosis, vacularization, or invasiveness of the tumors of the four implantation groups. Moreover, the amount of Snail protein between the four groups was comparable (Supporting Fig. 8). Similarly, the groups did not show significant differences in pancytokeratin, CK7, CK19, and apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling staining; data not shown). Local recurrences of HCC can progress rapidly after RFA,[5, 6], and cancer cells up-regulate CK19 (i.e., a feature of cholangiocarcinoma and hepatic progenitor cells).[34, 35] Recent studies also describe other progenitor cell biomarkers, such as CD133, that characterize HCC with enhanced malignant 上海皓元 potential.[36, 37] Here, we demonstrate that hepatoma cells that were exposed to sublethal heat for 10 minutes adopted molecular and functional characteristics of hepatic progenitors (CK7, CK19, and CD133), coupled with increased proliferation, up-regulation of genes that are involved in EMT (TWIST1, Snail, COL1A1, and CHDL1) and an enhanced malignant potential in vivo. Moreover, the observed EMT and aggressiveness of HCC cells exposed to sublethal heat were dependent on activation of the MAPKs, Erk1/2 (and upstream Shc).

14 In line with these antiinflammatory effects, hepatic LRH-1 acts as a potent suppressor of

the acute phase response.15, 16 Functional LRH-1 binding sites have been found within the promoter regions of several genes implicated in Small molecule library ic50 lipid metabolism and transport such as Abcg5/Abcg8, APOA1, and SR-B1.17-19 LRH-1 has been proposed to function as an important transcription factor in control of bile salt synthesis. The first and rate-controlling step in the classic pathway of bile acid synthesis is catalyzed by the enzyme cholesterol 7α-hydroxylase (CYP7A1).20 Subsequently 7α-hydroxycholesterol is converted into cholic acid by 12α-hydroxylase (CYP8B1), which determines the ratio in which the primary bile salt species cholate (3α,7α,12α-trihydroxy-5β-cholate) over chenodeoxycholate (3α,7α-dihydroxy-5β-cholate) are being produced.21 Hepatic bile salt synthesis is tightly regulated by complex feedback mechanisms involving the consecutive and/or simultaneous actions of a number of hepatic nuclear receptors and transcription

factors such as LXR, SREBPs, and HNF4.3, 22-25 In addition, LRH-1 binding sites have been identified in the proximal promoter parts of CYP7A1 and CYP8B1.8, 26 Data from cell studies showed that LRH-1 is able to induce the expression of CYP7A18, 22, 23 and CYP8B1.26 Therefore, LRH-1 has been proposed to function in feedback regulation of CYP7A1 expression as part of the FXR-SHP-LRH-1 cascade, in which bile acids can inhibit their own synthesis. In this cascade bile salt-activated hepatic FXR induces the expression of small heterodimer partner (SHP) that functions as a potent Pirfenidone ic50 repressor of hepatic LRH-1 activity,27 which then results in less activation of CYP7A1 by LRH-1. In addition, upon activation of intestinal FXR, the endocrine growth factor FGF15 is produced and transported to the liver, where it binds its receptor FGFR4 and represses CYP7A1 expression in the liver.28, 29 Thus, bile salt synthesis is under negative MCE feedback control from at least two distinct sites

in the enterohepatic system. Although the results from the initial cell studies8, 22, 23 were consistent with respect to the regulation of Cyp7a1 by LRH-1, they were in apparent contrast with those of subsequent in vivo studies using conditional Lrh-1 deletion.30, 31 Two independent studies showed that Cyp7a1 messenger RNA (mRNA) levels and protein activity were not reduced upon hepatocyte-specific Lrh-1 knockout, whereas, as expected, Cyp8b1 levels were.30, 31 These studies hence suggest that LRH-1 regulates composition and thus physicochemical properties of the bile salt pool but does not control bile salt synthesis rate in mice. Furthermore, heterozygous Lrh-1 knockout mice exhibited 5-7-fold higher Cyp7a1 expression levels and increased total bile acid pool sizes.32 Therefore, the proposed role of LRH-1 in the FXR-SHP-LRH-1 cascade, regulating Cyp7a1 expression, remained uncertain.

Overall, the 18O value of marine mammal body water is similar to that of environmental water, as their bioapatite phosphate and carbonate form in near isotopic equilibrium with environmental water. Clementz and Koch (2001) noted that there is a systematic difference in apatite 18O values between pinnipeds and cetaceans. Pinnipeds have

values expected for equilibrium with seawater at body temperature, whereas cetacean values are about 2‰ higher. They speculated on potential causes selleck screening library for this difference, but were unable to explain the difference. Clementz and Koch (2001) also noted that bioapatite 18O values from aquatic mammal teeth showed little within-population variability, presumably because body water 18O values vary little within an individual during its lifetime or among individuals in populations. Isotopic turnover rates can vary within or among individuals as a function of body size, growth rate, and protein turnover. A simple single-component box model shows that the rate of isotopic turnover is approximately equal to the net AP24534 datasheet rate of influx of new material divided

by the size of the pool of the element in the tissue. Because of the large daily fluxes of oxygen into and out of mammals, turnover times are rapid, on the scale of a week to a month, and are well established from the literature on isotope dilution and measurement of metabolic rate (Nagy and Costa 1980, Ortiz 2001). For carbon and nitrogen in tissues, the rate of elemental incorporation is approximately proportional to body mass (mb) to the 3/4 power (Martinez del Rio and Wolf 2005, Martinez del Rio et al. 2009), whereas the mass of animal tissues usually scales isometrically with mb. Thus, isotopic turnover of

metabolically active tissues is proportional to mb−1/4 (i.e., mb3/4/mb). This prediction has only been empirically tested on a single 上海皓元医药股份有限公司 tissue (red blood cells) from a few small bird species (Carleton and Martínez del Rio 2005). In addition to overall body size, both the growth of new tissue and the amount of tissue replacement due to catabolic turnover play fundamental roles in determining isotopic turnover rates. In short, the isotopic turnover rate equals the sum of the growth rate and the allometric effect of body size on catabolic turnover (mb−1/4). Most marine mammals undergo determinate growth, so for adults that are not nutritionally stressed, the growth term is zero; thus isotopic turnover rates should scale allometrically with mb−1/4. Like most endotherms, marine mammals only experience exponential growth during the first year of life and thus the growth of new tissue need only be considered for this ontogenetic stage. During this phase, mass-specific growth rate also scales with mb−1/4 because maximal growth rate (in units of mass per unit time) scales with mb3/4 (Martinez del Rio and Wolf 2005, Martinez del Rio et al. 2009).

Overall, the 18O value of marine mammal body water is similar to that of environmental water, as their bioapatite phosphate and carbonate form in near isotopic equilibrium with environmental water. Clementz and Koch (2001) noted that there is a systematic difference in apatite 18O values between pinnipeds and cetaceans. Pinnipeds have

values expected for equilibrium with seawater at body temperature, whereas cetacean values are about 2‰ higher. They speculated on potential causes Dasatinib purchase for this difference, but were unable to explain the difference. Clementz and Koch (2001) also noted that bioapatite 18O values from aquatic mammal teeth showed little within-population variability, presumably because body water 18O values vary little within an individual during its lifetime or among individuals in populations. Isotopic turnover rates can vary within or among individuals as a function of body size, growth rate, and protein turnover. A simple single-component box model shows that the rate of isotopic turnover is approximately equal to the net PLX4032 in vitro rate of influx of new material divided

by the size of the pool of the element in the tissue. Because of the large daily fluxes of oxygen into and out of mammals, turnover times are rapid, on the scale of a week to a month, and are well established from the literature on isotope dilution and measurement of metabolic rate (Nagy and Costa 1980, Ortiz 2001). For carbon and nitrogen in tissues, the rate of elemental incorporation is approximately proportional to body mass (mb) to the 3/4 power (Martinez del Rio and Wolf 2005, Martinez del Rio et al. 2009), whereas the mass of animal tissues usually scales isometrically with mb. Thus, isotopic turnover of

metabolically active tissues is proportional to mb−1/4 (i.e., mb3/4/mb). This prediction has only been empirically tested on a single 上海皓元医药股份有限公司 tissue (red blood cells) from a few small bird species (Carleton and Martínez del Rio 2005). In addition to overall body size, both the growth of new tissue and the amount of tissue replacement due to catabolic turnover play fundamental roles in determining isotopic turnover rates. In short, the isotopic turnover rate equals the sum of the growth rate and the allometric effect of body size on catabolic turnover (mb−1/4). Most marine mammals undergo determinate growth, so for adults that are not nutritionally stressed, the growth term is zero; thus isotopic turnover rates should scale allometrically with mb−1/4. Like most endotherms, marine mammals only experience exponential growth during the first year of life and thus the growth of new tissue need only be considered for this ontogenetic stage. During this phase, mass-specific growth rate also scales with mb−1/4 because maximal growth rate (in units of mass per unit time) scales with mb3/4 (Martinez del Rio and Wolf 2005, Martinez del Rio et al. 2009).

Overall, the 18O value of marine mammal body water is similar to that of environmental water, as their bioapatite phosphate and carbonate form in near isotopic equilibrium with environmental water. Clementz and Koch (2001) noted that there is a systematic difference in apatite 18O values between pinnipeds and cetaceans. Pinnipeds have

values expected for equilibrium with seawater at body temperature, whereas cetacean values are about 2‰ higher. They speculated on potential causes selleck products for this difference, but were unable to explain the difference. Clementz and Koch (2001) also noted that bioapatite 18O values from aquatic mammal teeth showed little within-population variability, presumably because body water 18O values vary little within an individual during its lifetime or among individuals in populations. Isotopic turnover rates can vary within or among individuals as a function of body size, growth rate, and protein turnover. A simple single-component box model shows that the rate of isotopic turnover is approximately equal to the net Selleckchem BMS-777607 rate of influx of new material divided

by the size of the pool of the element in the tissue. Because of the large daily fluxes of oxygen into and out of mammals, turnover times are rapid, on the scale of a week to a month, and are well established from the literature on isotope dilution and measurement of metabolic rate (Nagy and Costa 1980, Ortiz 2001). For carbon and nitrogen in tissues, the rate of elemental incorporation is approximately proportional to body mass (mb) to the 3/4 power (Martinez del Rio and Wolf 2005, Martinez del Rio et al. 2009), whereas the mass of animal tissues usually scales isometrically with mb. Thus, isotopic turnover of

metabolically active tissues is proportional to mb−1/4 (i.e., mb3/4/mb). This prediction has only been empirically tested on a single 上海皓元医药股份有限公司 tissue (red blood cells) from a few small bird species (Carleton and Martínez del Rio 2005). In addition to overall body size, both the growth of new tissue and the amount of tissue replacement due to catabolic turnover play fundamental roles in determining isotopic turnover rates. In short, the isotopic turnover rate equals the sum of the growth rate and the allometric effect of body size on catabolic turnover (mb−1/4). Most marine mammals undergo determinate growth, so for adults that are not nutritionally stressed, the growth term is zero; thus isotopic turnover rates should scale allometrically with mb−1/4. Like most endotherms, marine mammals only experience exponential growth during the first year of life and thus the growth of new tissue need only be considered for this ontogenetic stage. During this phase, mass-specific growth rate also scales with mb−1/4 because maximal growth rate (in units of mass per unit time) scales with mb3/4 (Martinez del Rio and Wolf 2005, Martinez del Rio et al. 2009).

In the last

few years, a positive correlation between seroprevalence of H. pylori and lung cancer has been described. A study by Behroozian et al. seems to confirm these findings Liproxstatin-1 mouse [9]. In particular, they looked for the prevalence of anti-H. pylori antibodies among 66 patients with lung cancer and 66 controls. Interestingly, they found a higher prevalence of H. pylori in patients with lung cancer compared with controls (73 vs 51%; odds ratio (OR): 2.51; [95% CI: 1.14–5.54]; p <.05). Nevertheless, whether the higher prevalence of H. pylori in patients with lung cancer is casual or causative still remains undetermined. Smoking habits might be confounding in both events. Interestingly, a case report was published by Riviere et al. showing the disappearance

of pulmonary sarcoidosis in a patient after H. pylori eradication [10]. Also in this case, whether H. pylori is the cause or a coincidence is still unknown. Helicobacter pylori is a well-recognized cause of idiopathic thrombocytopenic purpura (ITP) [11,12]. Studies published in the last year are in favor of this association. A study by Kikuchi et al., who re-evaluated 11 patients with ITP 8 years after H. pylori eradication, clearly showed the presence of a complete remission in all patients [13]. Fan et al. tested the efficacy of amifostine, a cytoprotective agent reducing reactive oxygen species, in treating patients with refractory ITP. Interestingly, all patients treated with this drug experienced a long-lasting remission, except for two, and one of these two patients relapsed following an H. pylori infection [14]. Matsukawa et al. focused on a peculiar interaction between H. pylori infection RO4929097 and peripheral platelet count in patients without ITP. In particular, the authors reported

a significant decrease in peripheral platelet counts in patients with H. pylori infection, after its successful eradication [15]; the clinical significance of such a phenomenon is still unclear. A study conducted by Gursel et al. showed that H. pylori infection may cause dysfunction of platelets in children and can be reversed by H. pylori eradication [16]. Those studies clearly demonstrate the existence of a close interaction between H. pylori and platelets, which surely merits further investigation. MCE Diamantidis et al. reported a high prevalence of H. pylori infection in Greek patients with myelodysplastic syndromes; nevertheless, there is no evidence for a causal relationship between those conditions so far [17]. Finally, Matsukawa et al. described the case of a patient with H. pylori-positive atrophic gastritis, who showed a significant increase in IgE and eosinophils after successful eradication of the infection [18]. Rahbani-Nobar et al. evaluated the effect of H. pylori treatment on remission of idiopathic central serous chorioretinopathy [19]. Twenty-five patients with idiopathic central serous chorioretinopathy who were infected with H. pylori were treated with an anti-H.

Changes in phytoplankton communities provide a sensitive early warning for climate-driven perturbations to marine ecosystems. “
“Algae have been estimated to include anything from 30,000

to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on-line taxonomic database AlgaeBase (http://www.algaebase.org). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the various algal phyla and classes, a conservative approach results in an estimate of 72,500 algal species, names for 44,000 of which have probably been published, and 33,248 names have been processed by AlgaeBase to date (June 2012). Alisertib cost Some published estimates of diatom numbers are of over 200,000 species, which would result selleck in four to five diatom species for every other algal species. Concern is expressed at the decline and potential extinction of taxonomists worldwide capable of improving and completing the necessary systematic studies. “
“Multiple clonal isolates from a geographic population of Alexandrium tamarense (M. Lebour) Balech from the North Sea exhibited

high genotypic and phenotypic variation. Genetic heterogeneity was such that no clonal lineage was repeatedly sampled according to genotypic markers specified by amplified fragment length polymorphism (AFLP) and microsatellites. Subsampling of genotypic data from both markers showed that ordination of individuals by pair-wise genetic dissimilarity indices was more reliable by AFLP (482 biallelic loci) than by microsatellites (18 loci). However, resulting patterns of pair-wise genetic similarities from both markers were significantly correlated (Mantel test P < 0.005). The composition of neurotoxins associated with paralytic shellfish poisoning (PSP) was also highly diverse among these isolates and allowed clustering of toxin phenotypes based MCE on prevalence of individual toxins. Correlation analysis

of pair-wise relatedness of individual clones according to PSP-toxin profiles and both genotypic characters failed to yield close associations. The expression of allelochemical properties against the cryptophyte Rhodomonas salina (Wisłouch) D. R. A. Hill et Wetherbee and the predatory dinoflagellate Oxyrrhis marina Dujard. manifested population-wide variation of responses in the target species, from no visible effect to complete lysis of target cells. Whereas the high genotypic variation indicates high potential for adaptability of the population, we interpret the wide phenotypic variation as evidence for lack of strong selective pressure on respective phenotypic traits at the time the population was sampled.

Changes in phytoplankton communities provide a sensitive early warning for climate-driven perturbations to marine ecosystems. “
“Algae have been estimated to include anything from 30,000

to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on-line taxonomic database AlgaeBase (http://www.algaebase.org). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the various algal phyla and classes, a conservative approach results in an estimate of 72,500 algal species, names for 44,000 of which have probably been published, and 33,248 names have been processed by AlgaeBase to date (June 2012). Acalabrutinib Some published estimates of diatom numbers are of over 200,000 species, which would result RG7204 cost in four to five diatom species for every other algal species. Concern is expressed at the decline and potential extinction of taxonomists worldwide capable of improving and completing the necessary systematic studies. “
“Multiple clonal isolates from a geographic population of Alexandrium tamarense (M. Lebour) Balech from the North Sea exhibited

high genotypic and phenotypic variation. Genetic heterogeneity was such that no clonal lineage was repeatedly sampled according to genotypic markers specified by amplified fragment length polymorphism (AFLP) and microsatellites. Subsampling of genotypic data from both markers showed that ordination of individuals by pair-wise genetic dissimilarity indices was more reliable by AFLP (482 biallelic loci) than by microsatellites (18 loci). However, resulting patterns of pair-wise genetic similarities from both markers were significantly correlated (Mantel test P < 0.005). The composition of neurotoxins associated with paralytic shellfish poisoning (PSP) was also highly diverse among these isolates and allowed clustering of toxin phenotypes based MCE公司 on prevalence of individual toxins. Correlation analysis

of pair-wise relatedness of individual clones according to PSP-toxin profiles and both genotypic characters failed to yield close associations. The expression of allelochemical properties against the cryptophyte Rhodomonas salina (Wisłouch) D. R. A. Hill et Wetherbee and the predatory dinoflagellate Oxyrrhis marina Dujard. manifested population-wide variation of responses in the target species, from no visible effect to complete lysis of target cells. Whereas the high genotypic variation indicates high potential for adaptability of the population, we interpret the wide phenotypic variation as evidence for lack of strong selective pressure on respective phenotypic traits at the time the population was sampled.

A group of patients who are closely followed

might avoid unnecessary surgery. Key Word(s): 1. NETs; 2. endoscopic treatment; 3. residual tumor; 4. risk factors; Presenting Author: JING WEN Additional Authors: ZHONGSHENG LU, YUNSHENG YANG, ENQIANG LINGHU, QINGSHEN LIU, XIANGDONG WANG, HONG DU, HONGBIN WANG Corresponding Author: ZHONGSHENG LU Affiliations: Department of Gastroenterology and Hepatology, Chinese PLA General Hospital Objective: To explore the risk factors and prognosis on positive resection margin after endoscopic submucosal dissection (ESD) for early esophageal cancer. Palbociclib cost Methods: A retrospective analysis of prospective collected data was performed on consecutive 148 lesions in 145 patients who underwent ESD. Age, sex, location, maximum diameter of resected specimens, macroscopic type, circumferential tumor sizes, different operators, depth of tumor invasion were evaluated as potential risk factors. Multivariable BAY 57-1293 concentration logistic regression analyse was used to determine risk factors for positive margin of resection. Results: There were 17 patients presenting with positive

resection margin after ESD and the positive rate was 11.4%. Among 16 Successfully followed patients, 3 patients were converted to surgery, one was received radiotherapy, three underwent additional endoscopic resection, and the other 9 patients who were initially followed up during a median period of 16.4 (range = 2–43) months had neither recurrence nor metastasis. On univariate analysis revealed that maximum diameter of resected specimens, depth of tumor invasion, macroscopic type were correlated with positive resection margin. Multivariable logistic regression analyse showed maximum

diameter MCE of resected specimens and depth of tumor invasion were risk factors on positive resection margin. Conclusion: Low incidence of positive resection margin was related with the depth of tumor invasion not to exceed submucosa and maximum diameter of resected specimens smaller than 3 cm. Key Word(s): 1. esophageal cancer; 2. ESD; 3. positive margin; 4. risk factors; Presenting Author: YOUXIANG CHEN Additional Authors: CHUN-YAN ZENG, GUO-HUA LI, XIAO-JIANG ZHOU, NONG-HUA LV Corresponding Author: YOUXIANG CHEN Affiliations: the First Affiliated Hospital of Nanchang University Objective: To explore the factors that may affect re-obstruction after metal stent (without covering) drainage for malignant biliary obstruction. Methods: Retrospective analysis of 63 cases with re-obstruction after metal stent (without covering) drainage in our hospital during recent eight years. To analyze the factors which affect the stent drainage patency period such as the sites, the range and the causes of obstruction, the methods of stent implantation, and so on. All of the datas were analyzed with SPSS statistics V17.0 software.

A group of patients who are closely followed

might avoid unnecessary surgery. Key Word(s): 1. NETs; 2. endoscopic treatment; 3. residual tumor; 4. risk factors; Presenting Author: JING WEN Additional Authors: ZHONGSHENG LU, YUNSHENG YANG, ENQIANG LINGHU, QINGSHEN LIU, XIANGDONG WANG, HONG DU, HONGBIN WANG Corresponding Author: ZHONGSHENG LU Affiliations: Department of Gastroenterology and Hepatology, Chinese PLA General Hospital Objective: To explore the risk factors and prognosis on positive resection margin after endoscopic submucosal dissection (ESD) for early esophageal cancer. check details Methods: A retrospective analysis of prospective collected data was performed on consecutive 148 lesions in 145 patients who underwent ESD. Age, sex, location, maximum diameter of resected specimens, macroscopic type, circumferential tumor sizes, different operators, depth of tumor invasion were evaluated as potential risk factors. Multivariable http://www.selleckchem.com/products/pexidartinib-plx3397.html logistic regression analyse was used to determine risk factors for positive margin of resection. Results: There were 17 patients presenting with positive

resection margin after ESD and the positive rate was 11.4%. Among 16 Successfully followed patients, 3 patients were converted to surgery, one was received radiotherapy, three underwent additional endoscopic resection, and the other 9 patients who were initially followed up during a median period of 16.4 (range = 2–43) months had neither recurrence nor metastasis. On univariate analysis revealed that maximum diameter of resected specimens, depth of tumor invasion, macroscopic type were correlated with positive resection margin. Multivariable logistic regression analyse showed maximum

diameter MCE公司 of resected specimens and depth of tumor invasion were risk factors on positive resection margin. Conclusion: Low incidence of positive resection margin was related with the depth of tumor invasion not to exceed submucosa and maximum diameter of resected specimens smaller than 3 cm. Key Word(s): 1. esophageal cancer; 2. ESD; 3. positive margin; 4. risk factors; Presenting Author: YOUXIANG CHEN Additional Authors: CHUN-YAN ZENG, GUO-HUA LI, XIAO-JIANG ZHOU, NONG-HUA LV Corresponding Author: YOUXIANG CHEN Affiliations: the First Affiliated Hospital of Nanchang University Objective: To explore the factors that may affect re-obstruction after metal stent (without covering) drainage for malignant biliary obstruction. Methods: Retrospective analysis of 63 cases with re-obstruction after metal stent (without covering) drainage in our hospital during recent eight years. To analyze the factors which affect the stent drainage patency period such as the sites, the range and the causes of obstruction, the methods of stent implantation, and so on. All of the datas were analyzed with SPSS statistics V17.0 software.