Masataka Hirabaru

Laparoscopic spleen-preserving distal pancreatectomy with and without splenic vessel preservation: The role of the Warshaw procedure

BACKGROUND/OBJECTIVES Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) for low-grade malignant pancreas tumors was recently demonstrated. Although the procedure with splenic vessel preservation (SVP) is optimal for LSPDP, SVP is not always possible in patients with a large tumor or a tumor attached to splenic vessels. This study aimed to analyze the safety of two procedures: LSPDP without SVP, known as the Warshaw technique (lap-WT), and LSPDP with SVP (lap-SVP). METHODS Seventeen patients who underwent a lap-WT and seven patients who underwent a lap-SVP were investigated retrospectively. RESULTS The median follow-up duration was 45 (range 17-105) months. In the lap-WT and lap-SVP patients, the sizes of the tumors were 5 (1.3-12) and 1.5 (1-4) cm; the operative times were 304 (168-512) and 319 (238-387) min; the blood loss was 210 (5-3250) and 60 (9-210) gr; the length of the postoperative hospital stay was 15 (8-29) and 18 (5-24) days; the peak platelet counts were 37.2 (14.6-65.2) and 26.4 (18.8-41) × 10(4)/μL, and splenomegaly was observed in 10 (59%) and three (43%) patients, respectively. In both procedures, there was no local recurrence. In the lap-WT group, splenic infarctions were seen in four (24%) patients and perigastric varices were seen in two (12%) patients. All of these patients were observed conservatively. CONCLUSIONS Both the lap-WT and lap-SVP were found to be safe and effective, and in cases in which the tumor is relatively large or close to the splenic vessels, lap-WT can be used as the more appropriate procedure.

Evaluation of SOX9 Expression in Pancreatic Ductal Adenocarcinoma and Intraductal Papillary Mucinous Neoplasm

Objectives Sex-determining region Y (SRY) box 9 (SOX9) is an important transcription factor required for development and has been implicated in several types of cancer. Sex-determining region Y box 9 has never been linked to pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasm (IPMN) of the pancreas. The aim of this study was to investigate the relationship between SOX9 and PDAC and that between SOX9 and IPMN. Methods Surgical specimens were obtained from 55 patients with PDAC and 68 patients with IPMN and were investigated using SOX9 immunohistochemical analysis. Results The rate of SOX9 positive cells to total pancreatic duct epithelial cells in a normal pancreas was 82.7%. On the other hand, the SOX9 positive rate in PDAC was 0.8%. There was a significant difference between the normal pancreas and PDAC (P = 0.0002). In IPMN, the SOX9 positive rate gradually decreased according to tumor progression, with the following rates observed: intraductal papillary mucinous adenoma (66.3%); noninvasive intraductal papillary mucinous carcinoma (46.3%); minimally invasive intraductal papillary mucinous carcinoma (30.5%); and invasive carcinoma originating in intraductal papillary mucinous carcinoma (2.3%). There were significant differences between each group (P < 0.05). Conclusions Our data suggested that SOX9 might contribute to carcinogenesis in PDAC and IPMN.

Endoscopic transpapillary pancreatic stenting for internal pancreatic fistula with the disruption of the pancreatic ductal system

BACKGROUND Internal pancreatic fistula (IPF) is a well-recognized complication of pancreatic diseases. Although there have been many reports concerning IPF, the therapy for IPF still remains controversial. We herein report our experiences with endoscopic transpapillary pancreatic stent therapy for IPF and evaluate its validity. METHOD Six patients with IPF who presented at our department and received endoscopic transpapillary pancreatic stent therapy were investigated, focusing on the clinical and imaging features as well as treatment strategies, the response to therapy and the outcome. RESULTS All patients were complicated with stenosis or obstruction of the main pancreatic duct, and in these cases the pancreatic ductal disruption developed distal to the areas of pancreatic stricture. The sites of pancreatic ductal disruption were the pancreatic body in five patients and the pancreatic tail in one patient. All patients received endoscopic stent placement over the stenosis site of the pancreatic duct. Three patients improved completely and one patient improved temporarily. Finally, three patients underwent surgical treatment for IPF. All patients have maintained a good course without a recurrence of IPF. CONCLUSION Endoscopic transpapillary pancreatic stent therapy may be an appropriate first-line treatment to be considered before surgical treatment. The point of stenting for IPF is to place a stent over the stenosis site of the pancreatic duct to reduce the pancreatic ductal pressure and the pseudocysts pressure.

A Method for Performing Islet Transplantation Using Tissue-Engineered Sheets of Islets and Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) are known to have a protective effect on islet cells. Cell sheets developed using tissue engineering help maintain the function of the cells themselves. This study describes a tissue engineering approach using islets with MSC sheets to improve the therapeutic effect of islet transplantation. MSCs were obtained from Fischer 344 rats and engineered into cell sheets using temperature-responsive culture dishes. The islets obtained from Fischer 344 rats were seeded onto MSC sheets, and the islets with MSC sheets were harvested by low-temperature treatment after coculture. The functional activity of the islets with MSC sheets was confirmed by a histological examination, insulin secretion assay, and quantification of the levels of cytokines. The therapeutic effects of the islets with MSC sheets were investigated by transplanting the sheets at subcutaneous sites in severe combined immunodeficiency (SCID) mice with streptozotocin-induced diabetes. Improvement of islet function and viability was shown in situ on the MSC sheet, and the histological examination showed that the MSC sheet maintained adhesion factor on the surface. In the recipient mice, normoglycemia was maintained for at least 84 days after transplantation, and neovascularization was observed. These results demonstrated that islet transplantation in a subcutaneous site would be possible by using the MSC sheet as a scaffold for islets.

Sox9 expression in carcinogenesis and its clinical significance in intrahepatic cholangiocarcinoma

BACKGROUND Intrahepatic cholangiocarcinomas develop through a multi-step carcinogenesis. Precancerous lesions are defined as biliary intraepithelial neoplasia. Sex determining region Y-box9 (Sox9) is required for the normal differentiation of the biliary tract. AIMS To evaluate the Sox9 expression in carcinogenesis and its correlation with clinicopathological features in intrahepatic cholangiocarcinoma. METHODS Sox9 expression in normal epithelium, biliary intraepithelial neoplasia, and intrahepatic cholangiocarcinoma were investigated immunohistochemically using 43 specimens of intrahepatic cholangiocarcinoma. Sox9 expression in intrahepatic cholangiocarcinoma was compared with the clinicopathological features. The molecular effects of Sox9 were investigated by gene transfection to intrahepatic cholangiocarcinoma cell lines. RESULTS Sox9 expression was decreased from the normal epithelium to the biliary intraepithelial neoplasia in a stepwise fashion. In 51.2% (22/43) of the patients with intrahepatic cholangiocarcinoma, Sox9 expression was positive, and Sox9 expression was significantly associated with the biliary infiltration (P=0.034) and poor overall survival (P=0.039). Upregulation of Sox9 promoted the cell migration and invasion, and decreased the E-cadherin expression and increased the vimentin and α-SMA expression in cell lines. CONCLUSIONS Decreased Sox9 expression may be related to the early stage of the carcinogenesis of intrahepatic cholangiocarcinoma. Sox9 overexpression in intrahepatic cholangiocarcinoma is related to biliary infiltration and poorer prognosis, and it promotes cell migration and invasion, via the epithelial-to-mesenchymal transition.

Expression of alpha smooth muscle actin in living donor liver transplant recipients

Recently, there have been reports from liver biopsies that showed the progression of liver fibrosis in liver transplant patients after the cessation of immunosuppression. Herein, we focused on activated hepatic stellate cells expressing alpha smooth muscle actin (α-SMA) to understand the correlation between immunosuppressant medication and liver fibrosis. The study enrolled two pediatric patients who underwent living donor liver transplantation and ceased immunosuppressant therapy. The number of α-SMA-positive cells in the specimens obtained by liver biopsy from these two patients showed a three-fold increase compared with the number from four transplanted pediatric patients who were continuing immunosuppressant therapy. In addition, the α-SMA-positive area evaluated using the WinRooF image processing software program continued to increase over time in three adult transplanted patients with liver fibrosis, and the α-SMA-positive area was increasing even during the pre-fibrotic stage in these adult cases, according to a retrospective review. Therefore, α-SMA could be a useful marker for the detection of early stage fibrosis.

Human Fibroblast Sheet Promotes Human Pancreatic Islet Survival and Function In Vitro.

In previous work, we engineered functional cell sheets using bone marrow-derived mesenchymal stem cells (BM-MSCs) to promote islet graft survival. In the present study, we hypothesized that a cell sheet using dermal fibroblasts could be an alternative to MSCs, and then we aimed to evaluate the effects of this cell sheet on the functional viability of human islets. Fibroblast sheets were fabricated using temperature-responsive culture dishes. Human islets were seeded onto fibroblast sheets. The efficacy of the fibroblast sheets was evaluated by dividing islets into three groups: the islets-alone group, the coculture with fibroblasts group, and the islet culture on fibroblast sheet group. The ultrastructure of the islets cultured on each fibroblast sheet was examined by electron microscopy. The fibroblast sheet expression of fibronectin (as a component of the extracellular matrix) was quantified by Western blotting. After 3 days of culture, islet viabilities were 70.2 ± 9.8%, 87.4 ± 5.8%, and 88.6 ± 4.5%, and survival rates were 60.3 ± 6.8%, 65.3 ± 3.0%, and 75.8 ± 5.6%, respectively. Insulin secretions in response to high-glucose stimulation were 5.1 ± 1.6, 9.4 ± 3.8, and 23.5 ± 12.4 μIU/islet, and interleukin-6 (IL-6) secretions were 3.0 ± 0.7, 5.1 ± 1.2, and 7.3 ± 1.0 ng/day, respectively. Islets were found to incorporate into the fibroblast sheets while maintaining a three-dimensional structure and well-preserved extracellular matrix. The fibroblast sheets exhibited a higher expression of fibronectin compared to fibroblasts alone. In conclusion, human dermal fibroblast sheets fabricated by tissue-engineering techniques could provide an optimal substrate for human islets, as a source of cytokines and extracellular matrix.

Increased expression of PHD3 represses the HIF-1 signaling pathway and contributes to poor neovascularization in pancreatic ductal adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma (PDAC) is known as one of the most malignant potential diseases with poor neovascularization. By comparing PDAC to hepatocellular carcinoma (HCC), which is well vascularized, we investigated the mechanisms and tumor biological significance of the poor neovascularization in PDAC.MethodsSurgical specimens from primary PDAC and HCC patients were immunohistologically stained to detect the expressions of CD105, CD44, HIF-1α, PHD3, and Siah2. We also used two PDAC and two HCC cell lines to compare the expressions of HIF-1α, PHD3, and CD44, as well as the production of VEGF in hypoxic condition. The role of PHD3 in regulating HIF-1α expression was further confirmed by siRNA knockdown in a PDAC cell line that highly expressed PHD3.ResultsThere were significantly fewer microvessels but more cancer stem cells in PDAC specimens compared to HCC specimens. The expression of CD105 was reversely related to the expression of CD44 in PDAC and HCC specimens. PDAC specimens also showed higher expressions of PHD3 but lower expressions of HIF-1α. Similarly, the expression of PHD3 was observed clearly in PDAC cell lines, but was almost completely negative in HCC cell lines. Hypoxic stimulation clearly enhanced HIF-1α expression and VEGF secretion in both HCC cell lines, but did not significantly change in PDAC cell lines. The knockdown of PHD3 in PDAC cells restored the hypoxic-induced HIF-1α expression, which accordingly stimulated the cells’ VEGF secretion.ConclusionsThe enhanced expression of PHD3 might likely contribute to the poor neovascularization and affect the biological characterization in PDAC cancer cells.

A Selective Cyclooxygenase-2 Inhibitor (Etodolac) Prevents Spontaneous Biliary Tumorigenesis in a Hamster Bilioenterostomy Model

Background: Secondary biliary carcinomas are associated with persistent reflux cholangitis after bilioenterostomy. Cyclooxygenase-2 (COX-2) has been a target for cancer prevention. The aim of this study was to evaluate the chemopreventive efficacy of long-term treatment with a selective COX-2 inhibitor medication during the natural course after bilioenterostomy without chemical induction. Methods: Syrian golden hamsters which underwent choledochojejunostomy were randomly divided into two groups: the control group (n = 31), which was fed a normal diet, and the etodolac group (n = 33), which was fed 0.01% etodolac (a selective COX-2 inhibitor) mixed in the meal. The hamsters were killed at the postoperative weeks 20-39, 40-59, 60-79, or 80-100. Biliary neoplasms, cholangitis, proliferating cell nuclear antigen labeling index (PCNA-LI) of the biliary epithelium, and prostaglandin E2 (PGE2) production were evaluated. Results: The occurrence rates of biliary neoplasm were 43.8 and 15.2% in the control and etodolac groups, respectively (p < 0.05). The incidence of biliary neoplasm increased as time progressed in the control group, whereas it remained at a low level throughout the experimental period in the etodolac group. PGE2 products tended to be lower in the etodolac group, and PCNA-LI was significantly lower in the etodolac group (p < 0.01). These results suggest that the medication etodolac suppresses cell proliferation of the biliary epithelium, thereby preventing biliary carcinogenesis. Conclusions: Etodolac is expected to prevent secondary biliary carcinogenesis caused by persistent reflux cholangitis after bilioenterostomy.

Dietary Zinc Supplementation to the Donor Improves Insulin Secretion After Islet Transplantation in Chemically Induced Diabetic Rats

Objectives Zinc (Zn) is related to insulin synthesis, storage, and secretion. This study demonstrates the effects of Zn supplementation in donor rats on the outcomes of islet transplantation. Methods Donor rats received 3 different regimens of dietary Zn supplementation for 2 weeks before undergoing pancreas donation: a standard diet containing Zn at 50 ppm (control), 1 ppm (low-Zn group) or 1000 ppm (high-Zn group), respectively. Diabetic recipient rats underwent islet transplantation, and the blood glucose levels and insulin secretion were monitored for 7 days after transplantation. Results The serum and pancreatic Zn levels at the time of donation were significantly lower in the low-Zn group (48.8 ± 25.5 µg/dL and 11.3 ± 1.9 µg/g) and higher in the high-Zn group (147.3 ± 17.6 µg/dL and 18.7 ± 2.2 µg/g) when compared with those observed in the controls (118.7 ± 7.9 µg/dL and 14.6 ± 2.0 µg/g) (P < 0.05). The blood glucose levels became re-elevated 2 days after transplantation in rats receiving islet grafts from the controls and the low-Zn groups. In contrast, in the rats that received islets from the high-Zn groups, these were maintained within a reference range (P < 0.01). Conclusions These data indicate that a Zn-rich diet for donor rats improves the function of islet grafts in chemically induced diabetic rats.