Masayuki Ohtsuka

Immunosuppression following surgical and traumatic injury.

Severe sepsis and organ failure are still the major causes of postoperative morbidity and mortality after major hepatobiliary pancreatic surgery. Despite recent progress in understanding the immune conditions of abdominal sepsis, the postoperative incidence of septic complications after major visceral surgery remains high. This review focuses on the clinical and immunological parameters that determine the risk of the development and lethal outcome of postoperative septic complication following major surgery and trauma. A review of the literature indicates that surgical and traumatic injury profoundly affects the innate and adaptive immune responses, and that a marked suppression in cell-mediated immunity following an excessive inflammatory response appears to be responsible for the increased susceptibility to subsequent sepsis. The innate and adaptive immune responses are initiated and modulated by pathogen-associated molecular-pattern molecules and by damage-associated molecular-pattern molecules through the pattern-recognition receptors. Suppression of cell-mediated immunity may be caused by multifaceted cytokine/inhibitor profiles in the circulation and other compartments of the host, excessive activation and dysregulated recruitment of polymorphonuclear neutrophils, induction of alternatively activated or regulatory macrophages that have anti-inflammatory properties, a shift in the T-helper (Th)1/Th2 balance toward Th2, appearance of regulatory T cells, which are potent suppressors of the innate and adaptive immune system, and lymphocyte apoptosis in patients with sepsis. Recent basic and clinical studies have elucidated the functional effects of surgical and traumatic injury on the immune system. The research studies of interest may in future aid in the selection of appropriate therapeutic protocols.

FGF10/FGFR2 signal induces cell migration and invasion in pancreatic cancer

Pancreatic cancer has one of the highest mortalities among all malignancies and there is an urgent need for new therapy. This might be achieved by resolving the detailed biological mechanism, and in this study we examined how pancreatic cancer cells develop aggressive properties by focusing on signalling through the fibroblast growth factor (FGF)10 and FGF receptor (FGFR)2, which play important roles in pancreatic organogenesis. Immunostaining of pancreatic cancer tissues showed that FGFR2 was expressed in cancer cells, whereas FGF10 was expressed in stromal cells surrounding the cancer cells. Patients with high FGFR2 expression in cancer cells had a shorter survival time compared to those with low FGFR2 expression. Fibroblast growth factor 10 induced cell migration and invasion of CFPAC-1 and AsPC-1 pancreatic cancer cells through interaction with FGFR2-IIIb, a specific isoform of FGFR2. Fibroblast growth factor 10 also induced expression of mRNA for membrane type 1-matrix metalloproteinase (MT1-MMP) and transforming growth factor (TGF)-β1, and increased secretion of TGF-β1 protein from these cell lines. These data indicate that stromal FGF10 induces migration and invasion in pancreatic cancer cells through interaction with FGFR2, resulting in a poor prognosis. This suggests that FGF10/FGFR2 signalling is a promising target for new molecular therapy against pancreatic cancer.

Usefulness of intraoperative fluorescence imaging to evaluate local anatomy in hepatobiliary surgery.

BACKGROUND/PURPOSE One of the major complications encountered in hepatobiliary surgery is the incidence of bile duct and blood vessel injuries. It is sometimes difficult during surgery to evaluate the local anatomy corresponding to hepatic arteries and bile ducts. We investigated the potential utility of an infrared camera system as a tool for evaluating local anatomy during hepatobiliary surgery. METHODS An infrared camera system was used to detect indocyanine green fluorescence in vitro. We also employed this system for the intraoperative fluorescence imaging of the arteries and biliary system in a pig. Further, we evaluated blood flow in the hepatic artery, portal vein, and liver parenchyma during a human liver transplant and we investigated local anatomy in patients undergoing cholecystectomy. RESULTS Fluorescence confirmed that indocyanine green was distributed in serum and bile. In the pig study, we confirmed the fluorescence of the biliary system for more than 1 h. In the liver transplant recipient, blood flow in the hepatic artery and portal vein was confirmed around the anastomosis. In most of the patients undergoing cholecystectomy, fluorescence was observed in the gallbladder, cystic and common bile ducts, and hepatic and cystic arteries. CONCLUSIONS Intraoperative fluorescence imaging in hepatobiliary surgery facilitates better understanding of the anatomy of arteries, the portal vein, and bile ducts.

Interleukin 18 causes hepatic ischemia/reperfusion injury by suppressing anti‐inflammatory cytokine expression in mice

Hepatic ischemia/reperfusion injury is a clinically important problem. While the mechanisms of the initial event and subsequent neutrophil‐dependent injury are somewhat understood, little is known about the regulation of endogenous hepatoprotective effects on this injury. Interleukin 12 (IL‐12) plays a role in the induction of this injury, but involvement of interleukin 18 (IL‐18) has not been clarified. Using a murine model of partial hepatic ischemia and subsequent reperfusion, the aim of the current study was to determine whether IL‐18 is up‐regulated during hepatic ischemia/reperfusion and to determine the role of endogenous IL‐18 in the development and regulation of inflammatory hepatic ischemia/reperfusion injury. Hepatic IL‐18 expression was up‐regulated from 1 to 8 hours after reperfusion. Hepatic ischemia/reperfusion induced nuclear factor‐κB (NF‐κB) and activator protein 1 (AP‐1) activation, as defined by electrophoretic mobility shift assay, and caused significant increases in liver neutrophil recruitment, apoptosis, hepatocellular injury, and liver edema as defined by liver myeloperoxidase content, terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate biotin nick end‐labeling (TUNEL) staining, serum aminotransferase levels, and liver wet‐to‐dry weight ratios. In mice treated with neutralizing antibody to IL‐18, ischemia/reperfusion‐induced increases in CXC chemokine expression, activation of NF‐κB and AP‐1, and apoptosis were greatly reduced. Furthermore, under blockade of IL‐18, anti‐inflammatory cytokines such as IL‐4 and IL‐10 were greatly up‐regulated. Signal transducer and activator of transcription 6 (STAT6) was significantly activated under blockade of IL‐18. These conditions also caused significant reduction in liver neutrophil sequestration and liver injury. In conclusion, the data suggest that IL‐18 is required for facilitating neutrophil‐dependent hepatic ischemia/reperfusion injury through suppressing anti‐inflammatory cytokine expression. (HEPATOLOGY 2004;39:699–710.)

Expression of an activated mammalian target of rapamycin (mTOR) in gastroenteropancreatic neuroendocrine tumors

AimsGastroenteropancreatic neuroendocrine tumors are rare, and the current WHO classification divides this tumor entity into well-differentiated (neuro)endocrine tumors, well-differentiated (neuro)endocrine carcinomas, and poorly differentiated (neuro)endocrine carcinomas. Poorly differentiated (neuro)endocrine carcinoma is extremely aggressive, and no appropriate therapeutic approach has been established. The mammalian target of rapamycin (mTOR), an important regulator of cell proliferation and protein translation, is activated in various malignancies. Recent phase II trial has revealed the efficacy of mTOR inhibitor (RAD001; everolimus) against low-to-intermediate grade neuroendocrine tumors. However, the beneficial role of mTOR inhibitor against poorly neuroendocrine carcinoma remains uncertain. The purpose of the present study was to determine the activation of mTOR in gastropancreatic neuroendocrine tumors, especially in poorly differentiated neuroendocrine carcinomas.MethodsExpression of p-mTOR(Ser2448) was assessed by immunohistochemistry in 20 gastropancreatic neuroendocrine tumors (seven well-differentiated neuroendocrine tumors, four well-differentiated neuroendocrine carcinomas, and nine poorly differentiated neuroendocrine carcinomas). Double immunohistochemistry was performed with p-Akt for patients with high p-mTOR expression.ResultsExpression of mTOR was seen in 9 (45%) of 20 gastroenteropancreatic neuroendocrine tumors. High expression of p-mTOR was seen in 6 (67%) of 9 poorly differentiated neuroendocrine carcinomas which was higher than the expression rate of well-differentiated neuroendocrine tumors and carcinomas, 3 (27%) of 11. All large cell neuroendocrine carcinomas showed high p-mTOR expression. Some tumor cells showed positive staining for p-mTOR co-expressed p-Akt.ConclusionsHigh expression rate of p-mTOR in poorly differentiated neuroendocrine carcinomas (large-cell type) may suggest the potential role of mTOR inhibitors as effective therapeutic agents for this highly malignant disease.

Aggressive Surgical Resection for Hilar Cholangiocarcinoma of the Left-Side Predominance: Radicality and Safety of Left-Sided Hepatectomy

Objectives:To evaluate the clinicopathologic outcomes in patients with hilar cholangiocarcinoma (HC) after left-sided hepatectomy (L-H). Summary Background Data:L-H is indicated as radical surgery for HC, predominantly involving left hepatic duct. However, several reports have demonstrated that L-H often results in tumor-positive margin and unfavorable prognosis compared with right-sided hepatectomy (R-H). Methods:A total of 224 patients with HC underwent surgical resection with curative intent at our institution: L-H for Bismuth-Corlette (B-C) type IIIb tumors in 88 patients (39.3%) including 75 left hemihepatectomies and 13 left trisectionectomies, and R-H mainly for B-C type IIIa and IV tumors in 84 patients (37.5%). In this study, clinicopathologic outcomes and perioperative morbidity and mortality rates after L-H were investigated and compared with those after R-H. Results:Histologically negative margin (R0) resection was achieved in 56 cases (63.6%) with L-H, similar to the results for R-H (58/84, 69.1%). However, the R0 resection rate in L-H cases with portal vein (PV) resection was lower (11/25, 44.0%), and various types of PV reconstruction were required. Proximal ductal stumps and excisional surface at periductal structures were the most common sites of positive margins. However, when curative resection was achieved, 5-year survival was comparable to that in R-H cases. Furthermore, lower mortality was noted in L-H cases, even with left trisectionectomy. Multivariate analysis indicated curability and hepatic artery resection as independent prognostic factors. Conclusions:Since L-H is a safe procedure and represents the only curative resectional option for type IIIb tumor, aggressive surgical resection should be performed even in cases with PV involvement, if R0 resection is possible.

Effects of perioperative immunonutrition on cell-mediated immunity, T helper type 1 (Th1)/Th2 differentiation, and Th17 response after pancreaticoduodenectomy

BACKGROUND The mechanisms of immunonutrition on reducing infectious complications are still poorly understood. This prospective randomized study was designed to determine whether immunonutrition influences the following factors: cell-mediated immunity, differentiation of T helper type 1 (Th1) and Th2 cells, interleukin (IL)-17-producing CD4(+) helper T (Th17) cell response, and infectious complication rate after pancreaticoduodenectomy. METHODS Thirty patients who underwent pancreaticoduodenectomy were divided into 3 groups. Ten patients in the perioperative group received immune-enhancing diets enriched with arginine, omega-3 fatty acids, and RNA for 5 days before operative resection, which was prolonged after operative resection by enteral infusion. Ten patients in the postoperative group received early postoperative enteral infusion of the same enriched formula with no artificial nutrition before operative resection. Ten patients in the control group received total parenteral nutrition postoperatively. The primary endpoint was immune responses; the secondary endpoint was the rate of infectious complications. RESULTS Concanavalin A (Con A)- or phytohemagglutinin (PHA)-stimulated lymphocyte proliferation and natural killer cell activity were significantly higher in the perioperative group than in the other groups. Messenger RNA (mRNA) expression levels of T-bet, interferon-gamma (IFN-gamma), related orphan receptor gammat (RORgammat), and interleukin-17F (IL-17F) were significantly higher in the perioperative group than in the other groups. In the perioperative group, the rate of infectious complications was significantly reduced compared with that in the other groups. CONCLUSION Perioperative immunonutrition reduced stress-induced immunosuppression after a major stressful operative resection. The modulation of Th1/Th2 differentiation and Th17 response may play important roles in this immunologic effect.

Classification of biliary tract cancers established by the Japanese Society of Hepato‐Biliary‐Pancreatic Surgery: 3rd English edition

The 3rd English edition of the Japanese classification of biliary tract cancers was released approximately 10 years after the 5th Japanese edition and the 2nd English edition. Since the first Japanese edition was published in 1981, the Japanese classification has been in extensive use, particularly among Japanese surgeons and pathologists, because the cancer status and clinical outcomes in surgically resected cases have been the main objects of interest. However, recent advances in the diagnosis, management and research of the disease prompted the revision of the classification that can be used by not only surgeons and pathologists but also by all clinicians and researchers, for the evaluation of current disease status, the determination of current appropriate treatment, and the future development of medical practice for biliary tract cancers. Furthermore, during the past 10 years, globalization has advanced rapidly, and therefore, internationalization of the classification was an important issue to revise the Japanese original staging system, which would facilitate to compare the disease information among institutions worldwide. In order to achieve these objectives, the new Japanese classification of the biliary tract cancers principally adopted the 7th edition of staging system developed by the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC). However, because there are some points pending in these systems, several distinctive points were also included for the purpose of collection of information for the future optimization of the staging system. Free mobile application of the new Japanese classification of the biliary tract cancers is available via http://www.jshbps.jp/en/classification/cbt15.html.

Effect of cold-ischemia time on C-X-C chemokine expression and neutrophil accumulation in the graft liver after orthotopic liver transplantation in rats.

Background. The precise mechanisms leading to polymorphonuclear neutrophil (PMN) recruitment and activation in the extended cold-preserved liver after transplantation are not yet fully understood. Methods. We histologically evaluated the number of accumulated PMNs in graft livers, with varying time periods of cold ischemia (1, 6, and 24 hr in University of Wisconsin solution at 4°C), after liver transplantation in rats. Intragraft expression of macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) mRNA, as well as immunohistochemical expression of MIP-2 and CINC in the graft liver, were investigated after reperfusion. The levels of MIP-2 and CINC in the hepatic vein, and tumor necrosis factor (TNF)-&agr;, which stimulates these chemokine production, were also monitored. Results. The number of accumulated PMNs in sinusoids significantly increased in the 24-hr cold-ischemia group within 3 hr after reperfusion, compared with the 1-hr and 6-hr groups. Serum MIP-2 levels in the 24-hr group significantly increased at 3, 6, and 12 hr after reperfusion, compared with the other groups. Intragraft MIP-2 mRNA was also up-regulated to a greater extent in the 24-hr group. Similarly, serum CINC levels in the 24-hr group significantly increased at 3 hr, compared with the 1-hr group. CINC mRNA also increased as cold-ischemia time was prolonged. Immunohistochemical staining revealed that hepatocytes were the main source of both MIP-2 and CINC protein. In addition, TNF-&agr; in the hepatic vein was detected only in the 24-hr group after reperfusion. Conclusion. Extended cold preservation of the graft liver might up-regulate MIP-2 and CINC expression of hepatocytes, most probably through elevated TNF-&agr;, and might contribute to PMN recruitment and activation after reperfusion.

Repeat pancreatectomy for pancreatic ductal cancer recurrence in the remnant pancreas after initial pancreatectomy: Is it worthwhile?

BACKGROUND The clinical implications of repeat completion pancreatectomy for recurrent pancreatic cancer in the remnant pancreas after initial pancreatectomy have not been clarified. We retrospectively analyzed our patients and evaluated the clinical implications of repeat pancreatectomy for isolated local recurrence in the remnant pancreas after initial resection for pancreatic cancer. METHODS One-hundred seventy patients who had recurrence of pancreatic cancer out of 326 patients who had initially undergone resection for pancreatic cancer were included in this study. Sixty-seven of 170 recurrent patients were diagnosed as having isolated local recurrence of pancreatic cancer. Eleven of these 67 patients with isolated local recurrence only in the remnant pancreas underwent repeat pancreatectomy. Characteristics and operative outcomes for these 11 patients with repeat pancreatectomy were analyzed and evaluated in comparison with other recurrent patients. RESULTS Among 170 patients with recurrence after initial resection for pancreatic cancer, the median survival time was 78.2 and 20.3 months after initial resection, in the repeat pancreatectomy group and the unresectable group, respectively (P < .001), and the 2- and 5-year survival probability rates after initial resection were 91%, and 82% vs 42%, and 13%, respectively. Among 67 patients with isolated local recurrence, the median survival time after repeat resection or diagnosis of recurrence was 25.0 and 9.3 months, and the 2- and 5-year survival probability rates after repeat resection or diagnosis of recurrence were and 61% and 46% vs 19% and 6.2% in the repeat pancreatectomy group and the unresectable group, respectively (P < .01). There was no difference in survivals between the unresectable isolated local recurrence group and the unresectable nonlocal recurrence group. CONCLUSION Repeat pancreatectomy might bring about beneficial effects on prognosis in selected patients with isolated local recurrence in the remnant pancreas after initial pancreatectomy for pancreatic cancer without increased operative morbidity or mortality.