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Biomedical subjects

Seungmin Bang

Publications and source records attributed to Seungmin Bang.

12 recordsLinked to original sources
PubMed2006

Endoscopic papillary balloon dilation with large balloon after limited sphincterotomy for retrieval of choledocholithiasis.

Endoscopic papillary balloon dilation (EBD) for choledocholithiasis is known to be comparable to endoscopic sphincterotomy (EST) especially in cases of small stones. With larger stones, EBD with conventional balloon, which have a diameter of 6-8 mm, was reported as less effective for extraction of stones. We evaluated the efficacy and complications of EBD with large balloons (10-15 mm) after limited EST for retrieval of choledocholithiasis. From February 2005, we have performed EBD with limited EST for retrieval of common bile duct (CBD) stones. The patients who admitted with hyperamylasemia and gallstone pancreatitis were excluded. In cases without CBD dilation, EPBD with 12 mm for 40 seconds was performed. And in cases with CBD dilation, we dilated the sphincters with 15 mm sized balloon for 40 seconds. Total 22 patients (11 of male) were performed EBD with limited EST for retrieval of CBD stones. The median diameter of the stones was 10 mm (5-25 mm). Ten cases had multiple stones and 6 cases periampullary diverticuli. Successful stone removal in the initial session of ERCP with EBD was accomplished in 16 patients (72.7%). And complete retrieval of bile duct stones was achieved in all patients with repeated ERCP. In the aspect of complications, any episodes of perforation, bleeding was not developed. Only one case of mild grade of post-procedural pancreatitis was noted. However, post-procedural hyperamylasemia was developed in 16 cases (68.2%). EBD with larger balloon seems to be a feasible and safe alternative technique for conventional EST in CBD stone extraction.

Aged↗
PubMed2006

Bile acid analysis in biliary tract cancer.

The etiology of biliary tract cancer is obscure, but there are evidences that bile acid plays a role in carcinogenesis. To find the association between biliary tract cancer and bile acid, this study compared the bile acid concentration and composition among patients with biliary cancer, biliary tract stones, and no biliary disease. Bile was compared among patients with biliary tract cancer (n = 26), biliary tract stones (n = 29), and disease free controls (n = 9). Samples were obtained by percutaneous transhepatic biliary drainage, endoscopic nasobiliary drainage, or gallbladder puncture, and analyzed for cholic, deoxycholic, chenodeoxycholic, lithocholic, and ursodeoxycholic acid composition. Total bile acid concentration was lower in the cancer group than the biliary stone and control groups; the proportions of deoxycholic (2.2% vs. 10.2% and 23.6%, p < 0.001 and p < 0.001, respectively) and lithocholic acid (0.3% vs. 0.6% and 1.0%, p = 0.065 and p < 0.001, respectively) were also lower. This result was similar when disease site was limited to bile duct or gallbladder. Analysis of cases with bilirubin <or= 2.0 mg/dL also showed lower total bile acid concentration and deoxycholic acid composition in the cancer group compared to controls (5.7% vs. 23.6%, p = 0.003). Although the presence of bile duct obstruction explains some of the difference in total concentration and composition of bile acid, there are other contributing mechanisms. We suspect the alteration of bile acid transport might decrease bile acid excretion and cause the accumulation of carcinogenic bile acid in bile duct epithelium.

Adolescent↗
PubMed2006

Phase II study of cisplatin combined with weekly gemcitabine in the treatment of patients with metastatic pancreatic carcinoma.

BACKGROUND/AIMS: Combination therapy of gemcitabine and cisplatin has been reported as an effective regimen for advanced pancreatic cancer. However, the toxicity and synergism are known to depend on the schedule of cisplatin. A phase II study was undertaken to determine the efficacy of a single dose of cisplatin in combination with weekly gemcitabine in patients with metastatic pancreatic carcinoma. METHODS: Patients with measurable, metastatic pancreatic carcinoma, not locally advanced diseases, were included. The patients were treated with a combination of gemcitabine 1,000 mg/m(2) i.v. over 30 min administered on days 1, 8, and 15 of each cycle and cisplatin 75 mg/m(2) i.v. administered 6 h after gemcitabine infusion on day 1 with adequate prehydration. Response and toxicity were assessed according to World Health Organization criteria. RESULTS: A total of 52 patients, 5 with recurrent disease after curative operation, were enrolled from January 2000 to March 2004. The objective response rate was 16 of 52 patients (1 complete response and 15 partial response). Disease stabilization was seen in 10 patients (20.8%). The median survival was 11.8 months (95% CI, 10.7-13.0 months), with 76.1% of patients alive at 6 months and 50% alive at 12 months. The median time to progression was 6.1 months (95% CI, 4.16-7.98 months). Major toxicity profiles were thrombocytopenia and neutropenia. CONCLUSIONS: The modified regimen of a single dose of cisplatin per cycle in combination with weekly gemcitabine appeared to have a more favorable therapeutic index and comparable toxicity profiles.

Adenocarcinoma↗
PubMed2006

[6]-Gingerol induces cell cycle arrest and cell death of mutant p53-expressing pancreatic cancer cells.

[6]-Gingerol, a major phenolic compound derived from ginger, has anti-bacterial, anti-inflammatory and anti-tumor activities. While several molecular mechanisms have been described to underlie its effects on cells in vitro and in vivo, the underlying mechanisms by which [6]-gingerol exerts anti-tumorigenic effects are largely unknown. The purpose of this study was to investigate the action of [6]-gingerol on two human pancreatic cancer cell lines, HPAC expressing wild- type (wt) p53 and BxPC-3 expressing mutated p53. We found that [6]-gingerol inhibited the cell growth through cell cycle arrest at G1 phase in both cell lines. Western blot analyses indicated that [6]-gingerol decreased both Cyclin A and Cyclin-dependent kinase (Cdk) expression. These events led to reduction in Rb phosphorylation followed by blocking of S phase entry. p53 expression was decreased by [6]-gingerol treatment in both cell lines suggesting that the induction of Cyclin-dependent kinase inhibitor, p21cip1, was p53-independent. [6]-Gingerol induced mostly apoptotic death in the mutant p53-expressing cells, while no signs of early apoptosis were detected in wild type p53-expressing cells and this was related to the increased phosphorylation of AKT. These results suggest that [6]-gingerol can circumvent the resistance of mutant p53- expressing cells towards chemotherapy by inducing apoptotic cell death while it exerts cytostatic effect on wild type p53- expressing cells by inducing temporal growth arrest.

Antineoplastic Agents↗
PubMed2006

The relationship of anatomic variation of pancreatic ductal system and pancreaticobiliary diseases.

The aims of this study were to identify the morphological diversities and anatomical variations of pancreatic ductal system and to define the relationships between pancreatic ductal systems, pancreaticobiliary diseases, and procedure- related complications, including post-ERCP pancreatitis. This study included 582 patients in whom both pancreatic duct (PD) and common bile duct were clearly visible by ERCP. PD systems were categorized into four types according to the relationship between common bile duct and PD. In types A and B, Wirsung duct formed the main PD. In type C, Wirsung duct did not form the main PD. If PD system did not fall into any of these three types, it was categorized as type D. The distribution of types among pancreatic ducts examined was as follows: type A: 491 cases (84.4%), type B: 56 cases (9.6%), type C: 20 cases (3.4%), and type D: 15 cases (2.6%). The anomalous anatomic variations of PD systems were divided into migration, fusion, and duplication anomalies. PD anomalies were noted in 51 patients, of which 19 (3.3%) were fusion anomalies (12 complete pancreas divisum, 7 incomplete pancreas divisum), and 32 (5.5%) were duplication anomalies (5 number variations, 27 form variations). No significant relationships between various PD morphologies and pancreaticobiliary diseases were found. However, post- ERCP hyperamylasemia was more frequently found in types C (41.7%), D (50%) and A (19.8%) than in type B (9.4%). In summary, whether Wirsung duct forms the main PD and the presence or absence of the opening of the Santorini duct are both important factors in determining the development of pancreatitis and hyperamylasemia after ERCP.

Bile Ducts↗
PubMed2006

The clinicopathologic significance of the expression of vascular endothelial growth factor-C in intrahepatic cholangiocarcinoma.

OBJECTIVES: Vascular endothelial growth factor-C (VEGF-C) is known to be an important lymphangiogenetic factor. Lymphatic spread is a key prognostic factor in intrahepatic cholangiocarcinoma (ICC). We studied the expression of VEGF-C in ICC tissues to clarify its clinicopathologic significance. METHODS: The expression of VEGF-C in surgical specimens obtained from 36 patients with ICC who underwent hepatic resection was examined by immunohistochemistry and Western blotting. Strong staining was defined as the presence of VEGF-C immunoreactivity in at least 50% of the tumor cells. Immunoreactivity in approximately 10% to approximately 50% of the tumor cells was considered as weak staining, and less than 10% as no staining. RESULTS: Of the 36 patients with ICC, 15 patients (41.7%) showed a strong positive result for VEGF-C. Eleven cases (30.6%) were negative and 10 cases (27.8%) showed weak immunoreactivity. VEGF-C expression was significantly correlated with lymph node metastasis (P = 0.032) and positive surgical margin (P = 0.03). Patients who had strong positive staining for VEGF-C showed significantly less favorable survival rates compared with patients who had negative or weak staining (P < 0.01). Other significant prognostic factors by univariate analysis were vascular invasion, lymph node involvement, and positive surgical margin. Multivariate analysis demonstrated that strong VEGF-C expression (P = 0.028) and vascular invasion (P = 0.021) were independent factors indicating poor prognosis. CONCLUSIONS: Our data suggest that VEGF-C expression serves as an independent and important prognostic factor in ICC patients, and it may play an important role in the lymph node metastasis of ICC.

Adult↗
PubMed2006

Differences in immune cells engaged in cell-mediated immunity after chemotherapy for far advanced pancreatic cancer.

OBJECTIVES: Little is known about the effects of chemotherapy on the immunity of cancer patient or the ideal timing for immunotherapy combined with chemotherapy. To address these questions, we evaluated the effect of gemcitabine and cisplatin combination chemotherapy on the immunity of pancreatic cancer patients. METHODS: Thirteen patients with far advanced pancreatic cancer were enrolled and 7 sex- and age-matched healthy volunteers were included as a control group. RESULTS: Compared with healthy controls, the amounts of peripheral blood mononuclear cells, dendritic cells (DCs), natural killer cells, CD4, and CD8 T cells were reduced. With this numerical suppression, NK cell cytotoxicity to K562 leukemia cells was also significantly impaired (7.7% +/- 4.9% versus 21.7% +/- 7.9% of DNA loss; P = 0.016). Serum concentrations of VEGF and interleukin-10 (IL-10) were higher than the control group (192.1 +/- 114.7 versus 50.8 +/- 39.5 pg/mL of vascular endothelial growth factor (VEGF) and 122 +/- 68.9 versus 111.4 +/- 37.4 pg/mL of IL-10). After 1 cycle of gemcitabine and cisplatin chemotherapy, the impaired immunity of patients with pancreatic cancer was restored. Specifically, the recovery of DCs occurred rapidly and exceeded the value of healthy controls. Levels of the immunosuppressive cytokines, IL-10 and VEGF, gradually decreased during chemotherapy. CONCLUSIONS: Systemic chemotherapy seems to be beneficial for restoring the impaired immunity of patients with pancreatic cancer, and one of the ideal times to collect DCs for immunotherapy is after completing each cycle of chemotherapy.

Aged↗
PubMed2006

Phase II study of gemcitabine and cisplatin in advanced biliary tract cancer.

BACKGROUND: The aim of this phase II study was to determine the efficacy of gemcitabine plus cisplatin chemotherapy in patients with advanced biliary tract cancer. METHODS: Eligibility criteria included histologically confirmed adenocarcinoma with measurable tumor in the biliary tract that was unresectable and either locally advanced or metastatic. Patients received a combination of gemcitabine (1000 mg/m(2) intravenously [IV] on days 1, 8, and 15) and cisplatin (75 mg/m(2) IV on day 1). Cycles were repeated every 28 days. Objective tumor response rates and toxicities were evaluated according to World Health Organization criteria. RESULTS: Twenty-seven patients were enrolled in the study and a total of 120 cycles of chemotherapy were administrated. Objective partial response was observed in nine (33.3%) patients, while stable disease was found in seven (25.9%) patients. The median survival time was 10.0 months and the 1-year survival rate was 36%. Median time to disease progression was 5.6 months. The most common grade 3-4 toxicities were leukopenia (25.9%), anemia (29.6%), thrombocytopenia (22.2%), and vomiting (18.5%). Only one patient was hospitalized for chemotherapy-related complications. CONCLUSION: Gemcitabine and cisplatin combination chemotherapy is an effective, safe, and well-tolerated regimen for the treatment of advanced biliary tract cancer.

Adult↗
PubMed2005

Enhancement of antitumor immunity of dendritic cells pulsed with heat-treated tumor lysate in murine pancreatic cancer.

Cancer vaccines using dendritic cells (DCs) have been shown to induce antitumor immunity and have recently been applied to non-immunogenic cancers, such as pancreatic cancer. In this study, we utilized DCs loaded with heat-treated tumor lysate (HTL-DC) as a vaccine in order to stimulate antitumor immunity in a murine pancreatic cancer model and compared them to DCs loaded with tumor lysate (TL-DC). The poorly immunogenic mouse ductal pancreatic cancer cell line PANC02 with syngeneic mouse strain C57BL/6 was used as a model. Inducible heat shock proteins (HSPs) were significantly increased in HTL (HSP70 and HSP90). Tumor size measurements indicated that HTL-DC induced stronger tumor suppression than unpulsed DC or TL-DC (43% reduction in tumor volume compared to control group). T cell proliferation assay and IFN-gamma ELISPOT assay showed that T cell activation increased in the following order: DC<TL-DC<HTL-DC. Furthermore, repeated HTL-DC vaccinations led to higher expansion of IFN-gamma-secreting T cells. Cytotoxicity assay revealed that HTL-DC were more efficient in priming PANC02-specific T cells. Our study identifies HTL as an effective source of tumor-associated antigens (TAAs) for pulsing DCs, and demonstrates that HTL-DC can generate a stronger and broader T cell response against fatal cancers, such as pancreatic cancer.

Animals↗
PubMed2003

CMV enteritis causing ileal perforation in underlying lupus enteritis.

We report a case of cytomegalovirus (CMV) enteritis in a 31 year-old -woman with lupus enteritis. In August 2002 the patient complained of severe abdominal pain. An abdominopelvic CT scan at the time showed free air in the peritoneal cavity and wall thickening of the ileal loop. She was diagnosed as having panperitonitis due to an ileal perforation, and underwent an emergency laparotomy. The surgical specimen revealed CMV inclusion bodies in the infarcted lesion. Her symptoms improved following the initiation of ganciclovir therapy. To the best of our knowledge, this is the first report in the English literature of an ileal perforation due to CMV infection in a patient with lupus enteritis.

Adult↗
PubMedDate not supplied

The clinical usefulness of 18-fluorodeoxyglucose positron emission tomography in the differential diagnosis, staging, and response evaluation after concurrent chemoradiotherapy for pancreatic cancer.

GOALS: The aims of this study were to determine the clinical use of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) in the differential diagnosis of patients with suspected pancreatic cancer and in the determination of tumor response after concurrent chemoradiotherapy for pancreatic cancer. BACKGROUND: Despite advances in diagnostic tools for pancreatic cancer, it is difficult to differentiate pancreatic cancer from mass-forming pancreatitis. Even with current imaging modalities, it is also difficult to assess tumor response to therapeutic intervention. STUDY: One hundred two patients with suspected pancreatic cancer were selected for this study. Dynamic computerized tomography (CT) scan and FDG-PET were used sequentially to diagnose pancreatic cancer. After diagnostic confirmation their diagnostic yields were compared. We also evaluated the treatment response in 15 patients who underwent chemoradiation therapy with dynamic CT scan and FDG-PET and compared their results. RESULTS: In 93 out of 102 patients, pancreatic cancer was confirmed. FDG-PET showed higher diagnostic accuracy than CT scan (95.1% vs. 76.5%). FDG-PET was also superior to CT in the detection of liver metastasis. FDG-PET detected treatment response in 5 out of 15 cases after chemoradiation therapy, whereas CT could not detect any treatment response. Comparing responder and nonresponder, FDG-PET was able to predict significantly different prognosis (399 vs. 233 d, P<0.05). CONCLUSIONS: FDG-PET is a very useful tool in diagnosing pancreatic cancer. FDG-PET may be also used as an adjunct for determining the treatment modality of pancreatic cancer and evaluating tumor response to chemoradiation therapy.

Aged↗