Sadaki Asari

MESENCHYMAL STEM CELLS SUPPRESS B-CELL TERMINAL DIFFERENTIATION

OBJECTIVE Mesenchymal stem cells (MSCs) have been shown to possess immunomodulatory properties on a diverse array of immune cell lineages. However, their effect on B lymphocytes remains unclear. We investigated the effect of MSCs on B-cell modulation with a special emphasis on gene regulation mediated by MSC humoral factors. MATERIALS AND METHODS MSCs were isolated from C57BL/6 bone marrow and expanded in culture. Splenic B cells were purified using anti-CD43 antibody and immunomagnetic beads. B cells and MSCs were cocultured in separate compartments in a transwell system. For B-cell stimulation, lipopolysaccharide was used in vitro and T-dependent and T-independent antigens were used in vivo. RESULTS In MSC cocultures, lipopolysaccharide-stimulated B-cell proliferation was suppressed, CD138(+) cell percentage decreased, and the number of apoptotic CD138(+) cells decreased. In the B/MSC coculture, the IgM(+) cell percentage was higher and the IgM amount released in the medium was lower than in the control. The B-lymphocyte-induced maturation protein-1 messenger RNA expression in the coculture was suppressed throughout the 3-day culture period. Conditioned media derived from MSC cultures prevented terminal differentiation of B cells in vitro and significantly suppressed the antigen-specific immunoglobulin M and immunoglobulin G1 secretion in mice immunized with T-cell-independent as well as T-cell-dependent antigens in vivo. CONCLUSION Results indicate that humoral factor(s) released by MSCs exert a suppressive effect on the B-cell terminal differentiation. Suppression may be mediated through inhibition of B-lymphocyte-induced maturation protein-1 expression, but the nature of the factor(s) is yet to be determined.

A prospective randomized comparison between pylorus‐ and subtotal stomach‐preserving pancreatoduodenectomy on postoperative delayed gastric emptying occurrence and long‐term nutritional status

Pylorus‐preserving pancreatoduodenectomy (PPPD) has been associated with a high incidence of delayed gastric emptying (DGE). There are few studies comparing DGE associated with PPPD and subtotal stomach‐preserving pancreatoduodenectomy (SSPPD). Moreover, differences between the procedures with respect to long‐term results have not been reported. A prospective randomized study was conducted to compare perioperative complications and long‐term nutritional status with PPPD and SSPPD.

18-Fluorodeoxyglucose Positron Emission Tomography Does Not Aid in Diagnosis of Pancreatic Ductal Adenocarcinoma

BACKGROUND & AIMS There are no accurate and reliable tools for diagnosis of early stage pancreatic ductal adenocarcinoma (PDA) or small metastatic lesions. It is also a challenge to differentiate PDA from focal mass-forming pancreatitis (FMP). There is controversy regarding the efficacy of 18-fluorodeoxyglucose positron-emission tomography (FDG-PET) in the diagnosis of PDA. We investigated whether FDG-PET provides information that, combined with data from other imaging techniques, can aid in decision making for patients with suspected PDA. METHODS We performed a retrospective analysis of data collected from 232 consecutive patients with suspected PDA at Kobe University Hospital from January 2006 through June 2012. All patients underwent a diagnostic imaging protocol that included multidetector row computed tomography, superparamagnetic iron oxide-enhanced magnetic resonance imaging, and FDG-PET. Based on endoscopic ultrasonography, fine-needle aspiration biopsy, or endoscopic retrograde cholangiopancreatography analyses, 218 patients had PDA (89 underwent resection and 129 did not) and 14 patients had FMP (8 had focal mass-forming chronic pancreatitis and 6 had focal mass-forming autoimmune pancreatitis). RESULTS FDG-PET detected 50% of stages 0 and I, 91.9% of stage II, 100% of stage III, and 96.8% of stage IV tumors. Detection was affected significantly by tumor size (P = .024) and T stage (P = .023) in resected tumors. Multidetector row computed tomography detected significantly more liver metastases than FDG-PET. Few para-aortic lymph node or peritoneal metastases were detected by FDG-PET. FDG-PET correctly identified 11 of the 14 patients with FMP (5 of 8 with focal mass-forming chronic pancreatitis and 6 of 6 with focal mass-forming autoimmune pancreatitis). CONCLUSIONS FDG-PET is not effective in detecting early stage PDA and small metastases, or in differentiating PDA from FMP. Combining FDG-PET with current diagnostic techniques for PDA did not provide any decisive information, therefore it should not be included in this analysis.

Improvement of canine islet yield by donor pancreas infusion with a p38MAPK inhibitor.

Background. The activation of p38 mitogen-activated protein kinases (MAPK) is implicated in cold ischemia-reperfusion injury of donor organs. The islet isolation process, from pancreas procurement through islet collection, may activate p38MAPK leading to cytokine release and islet damage. This damage may be prevented by treating pancreata with a p38MAPK inhibitor (p38IH) before cold preservation. Methods. Pancreata removed from Beagle dogs were infused with University of Wisconsin solution containing the p38IH, SB203580, and Pefabloc (n=6) or vehicle (dimethyl sulfoxide and Pefabloc) alone (n=7), through the pancreatic duct and preserved using the two-layer method. After 20 to 22 hr, islets were isolated and 3000 IEQ/kg were autotransplanted into the corresponding dog to monitor glucose metabolism. Results. p38IH-treated pancreata yielded significantly more islets than control pancreata (IEQ/g: 2134±297 vs. 1477±145 IEQ/g or 65,012±9385 vs. 45,700±5103 IEQ/pancreas; P<0.05). Apoptotic &bgr;-cell percentages assessed by laser scanning cytometry were lower in p38IH-treated than the controls (44%±9.4% vs. 61.6%±4.8%, P<0.05). Tumor necrosis factor-&agr; expression assessed by real-time reverse transcription polymerase chain reaction was significantly lower in the p38IH-treated group than controls. All dogs (3000 IEQ/kg) transplanted with p38IH-treated islets (n=5) became euglycemic versus four of five dogs that received untreated islets. Plasma C-peptide levels after glucagon challenge were higher in animals receiving p38IH-treated islets (n=5) versus untreated islets (n=4) (0.40±0.78 vs. 0.21±0.05 ng/mL, P<0.05). Conclusions. Infusion of pancreata with University of Wisconsin solution containing p38IH through the duct before preservation suppresses cytokine release, prevents &bgr;-cell apoptosis, and improves islet yield significantly with no adverse effect on islet function after transplantation. p38IH treatment of human pancreata may improve islet yield for use in clinical transplantation.

Proposed preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after surgical resection: A multi-center retrospective study

BACKGROUND/OBJECTIVE Although surgical resection remains the only chance for cure in patients with pancreatic ductal adenocarcinoma (PDAC), postoperative early recurrence (ER) is frequently encountered. The purpose of this study is to determine the preoperative predictive factors for ER after upfront surgical resection. METHODS Between 2001 and 2012, 968 patients who underwent upfront surgery with R0 or R1 resection for PDAC at seven high-volume centers in Japan were retrospectively reviewed. ER was defined as relapse within 6 months after surgery. Study analysis stratified by resectable (R) and borderline resectable (BR) PDACs was conducted according to the National Comprehensive Cancer Network guidelines. RESULTS ER occurred in 239 patients (25%) with a median survival time (MST) of 8.8 months. Modified Glasgow prognostic score = 2 (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.05-3.95; P = 0.044), preoperative CA19-9 ≥300 U/ml (OR 1.94, 1.29-2.90; P = 0.003), and tumor size ≥30 mm (OR 1.72, 1.16-2.56; P = 0.006), were identified as preoperative independent predictive risk factors for ER in patients with R-PDAC. In the R-PDAC patients, MST was 35.5, 26.3, and 15.9 months in patients with 0, 1 and ≥2 risk factors, respectively. There were significant differences in overall survival between the three groups (P < 0.001). No preoperative risk factors were identified in BR-PDAC patients with a high rate of ER (39%). CONCLUSIONS There is a high-risk subset for ER even in patients with R-PDAC and a simple risk scoring system is useful for prediction of ER.

A Focal Mass-Forming Autoimmune Pancreatitis Mimicking Pancreatic Cancer with Obstruction of the Main Pancreatic Duct

Introduction and backgroundAutoimmune pancreatitis (AIP) is a rare disease that closely mimics pancreatic cancer (PC) in its presentation. It is very important for clinicians to distinguish one from the other because their treatment and prognosis are vastly different. Typical radiological imaging findings, in particular observation of diffusely or segmentally narrowed main pancreatic duct (MPD) with an irregular wall by endoscopic retrograde cholangiopancreatography (ERCP), are essential for making the diagnosis of AIP. On the other hand, MPD obstruction is one of the most frequent features on ERCP.Case reportWe report a rare case of a patient with focal mass-forming AIP strongly suspected of being PC because of MPD obstruction on ERCP.ConclusionIt was difficult to distinguish PC from AIP with current diagnostic modalities. We will continue to make an effort to distinguish between the two disorders to prevent unnecessary surgery.

Mesenchymal stem cells facilitate mixed hematopoietic chimerism induction and prevent onset of diabetes in nonobese diabetic mice.

Objectives: Allogeneic mesenchymal stem cells (MSCs) and bone marrow cells (BMCs) were cotransplanted in nonobese diabetic mice after none myeloablative preconditioning and the development of chimerism, insulitis, diabetes, and graft-versus-host disease (GVHD) were monitored. Methods: Eight-week-old female nonobese diabetic mice were injected intravenously with 2 × 107 BMCs and 5 × 105 MSCs from C57BL/6 mice after treatment with 2 intraperitoneal injections of anti-CD3 antibody (days −7 and −4) and 3-Gy total body irradiation (day −1). Thereafter, blood glucose and chimerism were monitored on peripheral blood samples. Results: Stable mixed chimerism (3−>90% of donor phenotype) was induced in 63.2% of BMCs-MSCs recipients (n = 19) and 45.0% of BMCs-alone recipients (n = 20, P = 0.256). Insulitis was prevented, and euglycemia persisted for more than 18 weeks in 89.5% of BMCs-MSCs recipients including those with less than 3% chimerism and 55% of BM-alone recipients (P < 0.05). In controls, 9.1% of mice receiving preconditioning treatment alone (n = 11) and 16.7% of preconditioned mice receiving only MSCs (n = 12) were nondiabetic. Graft-versus-host disease was not detected in all mice. Conclusions: Coinjection of MSCs and BMCs increased the success rate in inducing chimerism and preventing insulitis and overt diabetes with no incidence of GVHD. Results also indicated that even microchimerism with less than 3% donor cells is sufficient for blocking autoimmunity.Abbreviations: Ab - antibody, BM - bone marrow, BMCs - bone marrow cells, FACS - fluorescence-activated cell sorting, GVHD - graft-versus-host disease, IL - interleukin, IV - intravenous(ly), L - ligand, mAb - monoclonal antibody, MLR - mixed lymphocyte reaction, MSCs - mesenchymal stem cells, NOD - nonobese diabetic, P - passage, PBLs - peripheral blood lymphocytes, PBS - phosphate-buffered saline, TBI - total body irradiation

Second primary pancreatic ductal carcinoma in the remnant pancreas after pancreatectomy for pancreatic ductal carcinoma: High cumulative incidence rates at 5 years after pancreatectomy

OBJECTIVES The aim of this study was to determine the incidence rate and clinical features of second primary pancreatic ductal carcinoma (SPPDC) in the remnant pancreas after pancreatectomy for pancreatic ductal carcinoma (PDC). METHODS Data of patients undergoing R0 resection for PDC at a single high-volume center were reviewed. SPPDC was defined as a tumor in the remnant pancreas after R0 resection for PDC, and SPPDC met at least one of the following conditions: 1) the time interval between initial pancreatectomy and development of a new tumor was 3 years or more; 2) the new tumor was not located in contact with the pancreatic stump. We investigated the clinical features and treatment outcomes of patients with SPPDC. RESULTS This study included 130 patients who underwent surgical resection for PDC between 2005 and 2014. Six (4.6%) patients developed SPPDC. The cumulative 3- and 5-year incidence rates were 3.1% and 17.7%, respectively. Four patients underwent remnant pancreatectomy for SPPDC. They were diagnosed with the disease in stage IIA or higher and developed recurrence within 6 months after remnant pancreatectomy. One patient received carbon ion radiotherapy and survived 45 months. One patient refused treatment and died 19 months after the diagnosis of SPPDC. CONCLUSIONS The incidence rate of SPPDC is not negligible, and the cumulative 5-year incidence rate of SPPDC is markedly high. Post-operative surveillance of the remnant pancreas is critical for the early detection of SPPDC, even in long-term survivors after PDC resection.

β-galactosidase of ROSA26 mice is a useful marker for detecting the definitive erythropoiesis after stem cell transplantation

Background. Hematopoietic reconstitution after stem cell transplantation has been analyzed by using stem cells of Ly5 congenic mice. However, the early erythropoiesis has never been analyzed because this marker is not expressed on all of the erythroid lineage cells. The transgenic mouse expressing &bgr;-galactosidase (&bgr;-gal) or green fluorescent protein (GFP) has been reported. Using these markers, we analyzed the early erythropoiesis after stem cell transplantation. Methods. The &bgr;-gal activity and GFP were examined in the hematopoietic cells of ROSA26 and GFP transgenic mice, respectively, by flow cytometry. The primitive hematopoietic stem cell fraction (Lin−c-kit+Sca-1+) in bone marrow (BM) cells of ROSA26 mice was transferred into lethally irradiated mice. The kinetics of hematopoietic reconstitution was analyzed in the BM and spleen after transplantation. Results. The &bgr;-gal activity, but not the GFP and Ly5, was detected in all of the erythroid (TER119+) cells. The &bgr;-gal activity was also detected in the donor-derived myeloid (Mac-1+), B lymphoid (B220+), and T lymphoid (Thy-1+) cells in the BM and spleen after stem cell transplantation. The kinetics of the hematopoietic reconstitution demonstrated that early erythroid (TER119lowCD71med) cells were developed in the BM and spleen within 2 days after transplantation before development of proerythroblasts (TER119+CD71high), and that massive erythropoiesis and myelopoiesis were observed in the spleen until 2 and 4 weeks after transplantation, respectively. Conclusions. The &bgr;-gal of ROSA26 mice can be a useful marker to identify the donor-derived hematopoietic cells, including early erythroid cells, and the first major wave of erythropoiesis occurring in the spleen after stem cell transplantation.

Duodenal protrusion by carcinosarcoma of the extrahepatic bile duct

Carcinosarcoma is a rare tumor and is pathologically composed of a mixture of malignant epithelial and mesenchymal components. We report a rare case of carcinosarcoma of the bile duct in which the tumor extended from the bile duct to the second portion of the duodenum. A 71-year-old man was admitted to our hospital due to repeated cholangitis. Contrast enhanced computed tomography showed an obstruction of the common bile duct and duodenum by a huge tumor extending from the bile duct to the duodenum (Fig. 1). Endoscopic retrograde cholangiopancreatography revealed a huge tumor with bleeding at the papilla of Vater, and a stent was successfully placed into the common bile duct (Fig. 2). The patient underwent pancreaticoduodenectomy. Gross examination of the resected specimen revealed a huge polypoid tumor (75 ¥ 50 mm) extending from the common bile duct into the duodenum. Histology showed both sarcomatous and adenocarcinomatous components. The sarcomatous lesion was dominant, and a few carcinomatous components existed in the bile duct wall and at the invasive front of the tumor. Sarcomatous cells were negative both for epithelial and nonepithelial markers, indicating that the tumor had no particular differentiation. The tumor was finally diagnosed as carcinosarcoma of the bile duct. Ki-67 index of the sarcomatous cells was 40%. His postoperative course was uneventful. Solitary liver metastasis was detected 3 months after the operation, and he died 10 months after the operation. Carcinosarcoma of the bile duct is extremely rare and has a dismal prognosis with no knowledge about the effective chemotherapy and radiotherapy. The only recognized treatment for this tumor is surgery. Although this tumor is generally discovered as a big polypoid tumor within the bile duct, our case developed beyond the bile duct into the duodenum. The high Ki-67 index of this tumor was indicative of the high proliferative activity of this tumor.