A Simple and Useful Predictive Assay for Evaluating the Quality of Isolated Hepatocytes for Hepatocyte Transplantation.

No optimal assay for assessing isolated hepatocytes before hepatocyte transplantation (HTx) has been established, therefore reliable and rapid assays are warranted. Isolated rat hepatocytes were dipped in a water bath (necrosis model), and were also cultured with Okadaic acid (apoptosis model) or vehicle, followed by cellular assessment including trypan blue exclusion (TBE) viability, ADP /ATP ratio, plating efficiency (PE), DNA quantity and ammonia elimination. Hepatocytes were transplanted into the liver of analbuminemic rats, subsequently engraftment was assessed by serum albumin and the histology of transplanted grafts. In the necrosis model, the ADP/ATP ratio was strongly and negatively correlated with the TBE (R2 = 0.559, P < 0.001). In the apoptosis model, the ADP/ATP ratio assay, PE, DNA quantification and an ammonia elimination test clearly distinguished the groups (P < 0.001, respectively). The ADP/ATP ratio, PE and DNA quantity were well-correlated and the ammonia elimination was slightly correlated with the transplant outcome. TBE could not distinguish the groups and was not correlated with the outcome. The ADP/ATP ratio assay predicted the transplant outcome. PE and DNA quantification may improve the accuracy of the retrospective (evaluations require several days) quality assessment of hepatocytes. The ADP/ATP ratio assay, alone or with a short-term metabolic assay could improve the efficiency of HTx.

Liver Transplantation for Homozygous Familial Hypercholesterolemia.

Pharmacological treatments to decrease low-density lipoprotein (LDL) cholesterol (LDL-C) have limited effects on patients with homozygous familial hypercholesterolemia (HoFH). Since LDL receptors are located mainly in the liver, liver transplantation is considered to be the only way to correct the hepatic cholesterol metabolism abnormalities in HoFH. Liver transplantations, including those combined with heart transplantation, for HoFH have been increasing since 1984, making this a globally established therapeutic option for HoFH. Plasma LDL-C is reported to be dramatically lowered, by 80%, after transplantation, with the rapid regression of cutaneous and tendinous xanthomas. However, long-term cardiovascular benefits remain unclear. The major concerns about liver transplantation include surgical complications, the need for lifelong immunosuppressive therapy, and rejection. In addition, organ transplantations from deceased donors are extremely rare in Japan. We experienced two pediatric siblings with HoFH who received living-donor liver transplantations from their heterozygous parents. Their plasma LDL-C levels decreased immediately and stabilized at approximately 200 mg/dL. Both developed normally with the administration of lipid-lowering medications and have been free of severe problems for more than 10 years, to date, since transplantation. In Japan, where the shortage of deceased donors is critical, the combination of living-donor liver transplant from a heterozygous donor, that is, usually a parent, and medication is regarded as a valid therapeutic option for HoFH. Further studies and clinical experience are required to establish liver transplantation as a safe and effective treatment for HoFH.

Bach2 Promotes B Cell Receptor-Induced Proliferation of B Lymphocytes and Represses Cyclin-Dependent Kinase Inhibitors.

BTB and CNC homology 2 (Bach2) is a transcriptional repressor that is required for the formation of the germinal center (GC) and reactions, including class switch recombination and somatic hypermutation of Ig genes in B cells, within the GC. Although BCR-induced proliferation is essential for GC reactions, the function of Bach2 in regulating B cell proliferation has not been elucidated. In this study, we demonstrate that Bach2 is required to sustain high levels of B cell proliferation in response to BCR signaling. Following BCR engagement in vitro, B cells from Bach2-deficient (Bach2-/-) mice showed lower incorporation of BrdU and reduced cell cycle progression compared with wild-type cells. Bach2-/- B cells also underwent increased apoptosis, as evidenced by an elevated frequency of sub-G1 cells and early apoptotic cells. Transcriptome analysis of BCR-engaged B cells from Bach2-/- mice revealed reduced expression of the antiapoptotic gene Bcl2l1 encoding Bcl-xL and elevated expression of cyclin-dependent kinase inhibitor (CKI) family genes, including Cdkn1a, Cdkn2a, and Cdkn2b Reconstitution of Bcl-xL expression partially rescued the proliferation defect of Bach2-/- B cells. Chromatin immunoprecipitation experiments showed that Bach2 bound to the CKI family genes, indicating that these genes are direct repression targets of Bach2. These findings identify Bach2 as a requisite factor for sustaining high levels of BCR-induced proliferation, survival, and cell cycle progression, and it promotes expression of Bcl-xL and repression of CKI genes. BCR-induced proliferation defects may contribute to the impaired GC formation observed in Bach2-/- mice.

The Effects of Short-term Subnormothermic Perfusion After Cold Preservation on Liver Grafts From Donors After Circulatory Death: An Ex Vivo Rat Model.

BACKGROUND: We previously reported that short oxygenated warm perfusion before cold storage (CS) had improved the graft viability of rat livers from donors after circulatory death (DCD). In this study, we investigated the effectiveness of short-term oxygenated subnormothermic perfusion for different durations after CS in a rat DCD model. METHODS: We used an isolated perfused rat liver system. In study 1: the grafts were retrieved from Wistar rats 30 minutes after cardiac arrest (thoracotomy), preserved in CS for 6 hours, and perfused with oxygenated subnormothermic (20-25°C) Krebs-Henseleit buffer for different durations (0, 15, 30, 60, and 90 minutes groups; n = 5 in each). In study 2: in addition to subnormothermic ex vivo liver perfusion (SELP), after 15-minute incubation at room temperature, the grafts were reperfused under normothermic condition for 60 minutes as a model of liver transplantation (0, 30, 60, and 90 minutes groups; n = 5 in each). RESULTS: In study 1, portal flow, bile production and tissue adenosine triphosphate increased with perfusion duration. In study 2, SELP significantly improved portal flow volume (P <0.05), and bile production (P <0.05), decreased liver enzymes (P <0.05) and cytokines (P <0.0001), and increased tissue adenosine triphosphate (P <0.01). Histological examinations showed that additional SELP ameliorated tissue deterioration, preserved the parenchymal structure, and decreased apoptosis (P <0.01). Furthermore, scanning electron microscopy revealed that additional SELP alleviated sinusoidal endothelial cells and hepatic microvasculature. CONCLUSIONS: Even 30 minutes of SELP after CS rescued DCD livers from ischemia-reperfusion injury, which may help the viability of the grafts.

Arterial and biliary complications after living donor liver transplantation: a single-center retrospective study and literature review.

AIM: The mortality of patients on the waiting list for deceased donor liver transplantation (DDLT) is high, especially in countries where donation rates are low. Thus, living donor liver transplantation (LDLT) is an attractive option. However, compared with DDLT, LDLT is associated with increased rates of arterial and biliary complications. We examined the rates of complications and risk factors following LDLT. METHODS: We retrospectively investigated and compared the rates of complications of DDLT and LDLT in our institute. We also performed univariate and multivariate analyses to identify the independent risk factors for these complications. The complications and specific disadvantages of LDLT were reviewed and discussed. RESULTS: The incidence rate of arterial complications in LDLT was 6.0%, compared with 3.2% (13/441) in DDLT. A multivariate analysis identified low body weight (P = 0.032) as the only independent risk factor for hepatic artery thrombosis. The rate of all biliary complications in LDLT was 17.3%, compared with 18.7% in DDLT. The risk factors for biliary stricture identified by the multivariate analysis were recurrent cholangitis and the number of bile ducts. The durations of hospital stay and overall survival rates were similar between the two groups. CONCLUSION: Given the shortage of deceased donor organs, we believe that LDLT is acceptable in an attempt to meet demand.

The Optimization of the Prevascularization Procedures for Improving Subcutaneous Islet Engraftment.

BACKGROUND: Subcutaneous islet transplantation is associated with minimal invasiveness, but poor vascularization. Thus, the optimization of the prevascularization procedures is crucial for improving the outcomes. Although the effectiveness of basic fibroblast growth factor (bFGF) was reported, the optimal procedures remain unclear. We sought to optimize the prevascularization procedures including the use of a novel scaffold, recombinant peptide (RCP). METHODS: Devices containing various amount of bFGF with/without heparin or RCP were implanted into the subcutaneous space of diabetic C57BL/6 mice. Syngeneic islets were transplanted into the prevascularized space. Blood glucose, intraperitoneal glucose tolerance, and immunohistochemistry were evaluated. RESULTS: The cure rates in all the device groups irrespective of bFGF doses were considerably higher than in the nondevice group. The cure rate in the bFGF0 group was unexpectedly higher than that in the subcutaneous islet transplant alone group (the None group) (57.1% vs 28.6%). Glucose tolerance was ameliorated in the bFGF10(-), 10(+) and 15(-) groups. The number of von Willebrand factor-positive vessels in the bFGF10(+) group was significantly higher than that in the None and bFGF0 groups (P < 0.01). Taken together, the bFGF10(+) group was considered to have received optimized procedures. In a marginal graft model, the efficiency in the RCP group was better than that in the bFGF10(+) group, furthermore, comparable to that in the intraportal transplantation group. Unlike bFGF, no bleeding and effusion were observed in the RCP group. CONCLUSIONS: These results suggest that optimizing biomaterials to induce efficient prevascularization could be a novel strategy for improving subcutaneous islet transplantation.

The Optimization of Short-Term Hepatocyte Preservation Before Transplantation.

BACKGROUND: No optimal methods for short-term hepatocyte preservation have been established. We have recently developed a prominent oxygen-permeable bag (Tohoku Device [TD]) for pancreatic islet culture and transplantation. In this study, we investigated whether TD is also effective for hepatocyte preservation and tried to optimize other conditions. METHODS: Hepatocytes were preserved in the following conditions, and their outcomes were observed. First, the effectiveness of TD was investigated. Second, hepatocyte medium (HM) and organ preservation solutions with or without fetal bovine serum (FBS) were compared. Third, as supplementations, FBS and human serum albumin (HSA) were compared. Fourth, low, room and high temperature were compared. And finally, hepatocytes preserved in various conditions were transplanted into the subrenal capsule space of nonalbumin rats and engrafted areas were assessed. RESULTS: The survival rate of hepatocytes preserved in TD tended to be higher and their viability and function were maintained significantly greater than those of non-TD group. Irrespective of FBS supplementation, the survival rate of HM group was significantly higher than those of organ preservation solution group while viabilities and plating efficiency were similar among them. Although survival rates of groups without FBS were extremely low, results of HSA supplemented group were not inferior to FBS supplemented group. Hepatocytes preserved at high temperature had the worst results. The engrafted area of TD group tended to be higher than those of other groups. CONCLUSIONS: TD is effective for short-term hepatocyte preservation. HSA is a useful substitute for FBS, and preserving in HM at low temperature is recommended.

Early post-transplant hyperbilirubinemia is a possible predictive factor for developing neurological complications in pediatric living donor liver transplant patients receiving tacrolimus.

The cause of post-transplant CNI-NCs is multifactorial and not ascribed solely to CNI toxicity. A total of 90 children (aged <20 years) who underwent LDLT were evaluated to investigate the predictive factors associated with CNI-NCs. Twelve patients (13.3%) developed CNI-NCs after LDLT (age range, 2-15 years). The symptoms of CNI-NCs were seizures, VD, and stupor. The median onset of CNI-NCs was 10 days (range, 5-30 days) post-transplant. In the univariate analysis, higher recipient age at LDLT, donor age and recipient's BW, lower actual GV/SLV and TAC dosage/BW, and higher mean T-Bil and sodium level for 7 days after transplantation were independently significantly associated with TAC-NCs. Multivariate analysis showed that the T-Bil level in the first week after LDLT was the only significant independent predictive factor for TAC-NCs (HR, 1.588; 95% CI, 1.042-2.358; P=.031). In conclusion, CNI-NCs occurred most frequently in children over 5 years and were associated with hyperbilirubinemia for 7 days post-transplant, regardless of TAC levels. The transplant team should refer to a neurologist to define the diagnosis and to collaborate to resolve the neurological problems.

Soluble Thrombomodulin Ameliorates Ischemia-Reperfusion Injury of Liver Grafts by Modulating the Proinflammatory Role of High-Mobility Group Box 1.

Transplantation using grafts obtained after cardiac death (CD) is considered a promising solution for graft shortages. However, no standard criteria for organ preservation have been established for CD donors. High-mobility group box 1 (HMGB1) is a DNA-binding protein that is released from dying hepatocytes as an early mediator of inflammation and organ tissue damage. HMGB1 stimulates immunocytes to produce inflammatory cytokines, thereby amplifying the inflammatory response. Thrombomodulin is an integral membrane protein that functions as an endothelial anticoagulant cofactor, and it binds HMGB1 through the extracellular domain. We investigated the effects of ART-123, recombinant human soluble thrombomodulin, on warm ischemia-reperfusion injury in liver grafts. Male Wistar rats were divided into four ex vivo groups: heart-beating (HB) group, in which livers were isolated from HB donors; CD group, in which livers were isolated from CD donors exposed to apnea-induced conditions and warm ischemic conditions for 30 min after cardiac arrest; and two CD groups pretreated with ART-123 (1 or 5 mg/kg). Each isolated liver was reperfused for 1 h after cold preservation for 6 h. The perfusate levels of HMGB1, LDH, TNF-α, and IL-6 were significantly lower in the CD group pretreated with ART-123 (5 mg/kg) than in the CD group. Bile production was significantly higher in the CD group pretreated with ART-123 (5 mg/kg) than in the CD group. The sinusoidal spaces were significantly narrower in the CD group than in the other groups. We propose that ART-123 maintains sinusoidal microcirculation by reducing endothelial cell damage during warm ischemia-reperfusion injury.

National Clinical Database feedback implementation for quality improvement of cancer treatment in Japan: from good to great through transparency.

The National Clinical Database (NCD) of Japan was established in April, 2010 with ten surgical subspecialty societies on the platform of the Japan Surgical Society. Registrations began in 2011 and over 4,000,000 cases from more than 4100 facilities were registered over a 3-year period. The gastroenterological section of the NCD collaborates with the American College of Surgeons' National Surgical Quality Improvement Program, which shares a similar goal of developing a standardized surgical database for surgical quality improvement, with similar variables for risk adjustment. Risk models of mortality for eight procedures; namely, esophagectomy, partial/total gastrectomy, right hemicolectomy, low anterior resection, hepatectomy, pancreaticoduodenectomy, and surgery for acute diffuse peritonitis, have been established, and feedback reports to participants will be implemented. The outcome measures of this study were 30-day mortality and operative mortality. In this review, we examine the eight risk models, compare the procedural outcomes, outline the feedback reporting, and discuss the future evolution of the NCD.

Pure laparoscopic hepatectomy combined with a pure laparoscopic pringle maneuver in patients with severe cirrhosis.

Laparoscopic hepatectomy is a standard surgical procedure. However, it is difficult to perform in patients with severe cirrhosis because of fibrosis and a high risk of hemorrhage. We report our recent experience in five cases of pure laparoscopic hepatectomy combined with a pure laparoscopic Pringle maneuver in patients with severe cirrhosis. From 2012 to 2014, we performed pure laparoscopic partial hepatectomy in five patients with severe liver cirrhosis (indocyanine green retention rate at 15 min [ICG R15] >30% and fibrosis stage f4). A pure laparoscopic Pringle maneuver was employed in all patients. We investigated operative time, blood loss, duration of hospitalization and the days when discharge was possible, and compared these findings with those of patients with a normal liver (ICG R15 <10%, f0) who underwent pure laparoscopic partial hepatectomy during the same period (n = 7). As a result, operative time, blood loss, duration of hospitalization and the days when discharge was possible were similar in patients with cirrhosis undergoing pure laparoscopic hepatectomy combined with a pure laparoscopic Pringle maneuver to those in patients with a normal liver undergoing pure laparoscopic partial hepatectomy. In conclusion, pure laparoscopic hepatectomy combined with a pure laparoscopic Pringle maneuver appears to be safe in patients with severe cirrhosis.

Synergistic Effect of Neutral Protease and Clostripain on Rat Pancreatic Islet Isolation.

BACKGROUND: Islet isolation currently requires collagenase, neutral protease and other components. Thermolysin (TL) from Bacillus thermoproteolyticus is the gold standard neutral protease. However, we speculated that neutral protease derived from Clostridium histolyticum (Ch; ChNP) would be biologically superior for islet isolation. Tryptic-like activity has also been reported to be important. Therefore, we focused on clostripain (CP), since it is one of the main proteases in Clostridium histolyticum which possesses tryptic-like activity. We then examined the synergistic effects of highly purified ChNP and CP on rat islet isolation. METHODS: The same amount of collagenase was used in all four groups (TL, ChNP, TL+CP and ChNP+CP; n = 12/group). The efficiency was evaluated by the islet yield and function. An immunohistochemical analysis, in vitro digestion assay for each enzyme component and evaluation of the activation of endogenous exocrine proteases during islet isolation were also performed. RESULTS: The islet yield of the TL group was significantly higher than that of the ChNP group (P < 0.01). The islet yield was dose dependently increased in the ChNP+CP group, but was decreased in the TL + CP group. The islet yield in the ChNP + CP group was significantly higher than that in the TL group, but their islet function was similar. Different specificities for laminin, especially laminin-511, were observed in the TL, ChNP, and CP groups. CONCLUSIONS: Clostripain had a strong synergistic effect with ChNP, but not with TL. Therefore, ChNP and CP, in combination with collagenase derived from the same bacteria, may effectively increase the isolation efficiency without affecting the quality of islets.

Epstein-Barr virus--associated posttransplantation lymphoproliferative disorder with tacrolimus metabolism deterioration in infants after living-donor liver transplantation.

BACKGROUND: Posttransplantation lymphoproliferative disorder (PTLD) in infants after liver transplantation is strongly associated with tacrolimus (Tac) administration and primary Epstein-Barr virus (EBV) transmission. METHODS: From 1991 to 2012, 32 survivors younger than 2 years who had undergone living-donor liver transplantation using Tac for primary immunosuppression were retrospectively investigated for changes in Tac trough levels before and at the onset of posttransplantation viral infection episodes. RESULTS: Twenty-one recipients experienced 33 viral infection episodes associated with EBV-related PTLD (n = 5), symptomatic EBV infection without development of PTLD (n = 8), and other viral infections (n = 20). Although the average Tac trough levels during the 2 months before the onset of viral infection episodes were similar among the 33 episodes (9.0 ± 2.8 ng/mL), the Tac trough levels at the onset were significantly higher in the episodes with PTLD than in those with EBV infection without the development of PTLD and with other viral infections (19.2 ± 9.0 ng/mL vs. 9.3 ± 5.2 ng/mL and 10.6 ± 5.1 ng/mL, respectively) (P<0.05). Tacrolimus trough levels at the onset of PTLD were significantly higher during the 2 months before the onset (median, 1.83 times higher than average) compared with EBV infection (1.14 times higher) and other viral infections (1.06 times higher) (P<0.05). The Tac blood concentration-to-dose ratio at the onset of PTLD was more than twice as high as the average value during the 2 months before the onset. CONCLUSION: Deteriorated Tac metabolism accompanied by a positive change in the blood EBV DNA load may enable us to predict the development of PTLD in liver-transplanted infants with viral infection.

Renal function status in liver transplant patients in the first month post-transplant is associated with progressive chronic kidney disease.

AIM: Renal dysfunction is a common complication of liver transplantation (LT), related to hepatorenal syndrome with end-stage liver disease or calcineurin-inhibitor nephrotoxicity. Chronic kidney disease (CKD) is also a common problem in long-term survivors post-LT. This study was done to investigate the association between renal functional status soon after LT and the development of CKD. METHODS: We retrospectively evaluated 63 patients who were aged 18 years or older, and underwent LT at Tohoku University Hospital. The estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease study equation for Japan. RESULTS: Before transplantation, 25 patients (39.7%) were diagnosed with CKD (eGFR, <60 mL/min per 1.73 m(2) ). The incidence of CKD was 22.4% (13/58) at 2 years, 23.2% (13/56) at 3 years and 22.7% (12/54) at 5 years. The patients with CKD at 2 years post-transplant were more likely to have a history of glomerulonephritis, and were significantly older at the time of LT, compared to those without CKD. Levels of eGFR of less than 60 mL/min per 1.73 m(2) in the first month post-transplant and a volume of intraoperative blood loss of more than 300 mL/kg were predictive factors for the development of CKD at 2 years post-transplant and thereafter. CONCLUSION: We have shown that there is an improvement of renal function in the majority of patients after LT. Regardless of the presence of pre-existing CKD, both renal function status at the first month post-transplant and a volume of intraoperative blood loss were predictive factors for the development of CKD at 2 years post-transplant and thereafter.

Hepatic venous reconstruction using the superficial femoral vein in a right-lobe living donor liver transplant patient with interrupted inferior vena cava.

Anatomical abnormalities in patients with BA often include polysplenia, preduodenal portal vein, interrupted retrohepatic IVC, cardiac abnormalities, and situs inversus. In LDLT patients who had congenital vascular anomalies, additional surgical modifications for the reconstruction of hepatic venous branches are sometimes necessary to prevent venous parenchymal congestion. We report a 12-yr-old female with post-Kasai BA with interrupted retrohepatic IVC who underwent right-lobe LDLT because the left liver graft volume was insufficient. The donor right liver graft had three major hepatic branches, including the RHV, IRHV, and MHV tributary (V8). We performed hepatic venous reconstruction by creating a large, wide triple orifice consisting of the RHV and two SFVs, which were anastomosed to the V8 and IRHV using the donor's SFV as an interposition graft. In conclusion, the reconstruction of venous orifices for right-lobe LDLT patients with the absent retrohepatic IVC is can be carried out using an SFV graft derived from the living donor or the recipient.

A novel resting strategy for improving islet engraftment in the liver.

BACKGROUND: Several studies have revealed that posttransplant insulin treatment is beneficial to rest the islet grafts. However, insulin infusion per se is not enough to completely suppress the heavy workload arising caused by postprandial hyperglycemia. Therefore, the present study examined whether short-term fasting combined with insulin treatment could effectively prevent graft exhaustion after intraportal islet transplantation. METHODS: A marginal dose of syngeneic rat islet grafts were transplanted intraportally into the control, insulin-treated, and insulin+rest groups of streptozotocin-induced diabetic rats. The control group fed freely without insulin treatment, and the other groups were continuously treated with an optimal amount of insulin to maintain normoglycemia. In addition, the insulin+rest group fasted and received total parenteral nutrition during the 2 weeks after transplantation. RESULTS: The curative rate was significantly higher in both the insulin and insulin+rest groups than the control group (P<0.0001). The glucose tolerance, residual graft mass, and graft function were significantly ameliorated in the insulin+rest group, but not in the insulin group, compared to the control group (P<0.01, P=0.03, P=0.001). CONCLUSIONS: These data suggest that short-term fasting combined with insulin treatment, especially during the avascular period of the grafts, could therefore be a promising regimen for improving pancreatic islet engraftment in the liver.

Collagenase H is crucial for isolation of rat pancreatic islets.

The role(s) of collagenase G (ColG) and collagenase H (ColH) during pancreatic islet isolation remains controversial, possibly due to the enzyme blends used in the previous studies. We herein examined the role of ColG and ColH using highly pure enzyme blends of recombinant collagenase of each subtype. Rat pancreases were digested using thermolysin, together with ColG, ColH, or ColG/ColH (n = 9, respectively). No tryptic-like activity was detected in any components of the enzyme blends. The efficiency of the collagenase subtypes was evaluated by islet yield and function. Immunohistochemical analysis, in vitro collagen digestion assay, and mass spectrometry were also performed to examine the target matrix components of the crucial collagenase subtype. The islet yield was highest in the ColG/ColH group (4,101 ± 460 islet equivalents). A substantial number of functional islets (2,811 ± 581 islet equivalents) was obtained in the ColH group, whereas no islets were retrieved in the ColG group. Mass spectrometry demonstrated that ColH reacts with collagen I and III. In the immunohistochemical analysis, both collagen I and III were located in exocrine tissues, although collagen III expression was more pronounced. The collagen digestion assay showed that collagen III was more effectively digested by ColH than by ColG. The present study reveals that ColH is crucial, while ColG plays only a supporting role, in rat islet isolation. In addition, collagen III appears to be one of the key targets of ColH.

Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas: report of a case.

We report a rare case of an intraductal papillary mucinous neoplasm (IPMN) originating from a jejunal heterotopic pancreas, found incidentally during surgery. A 75-year-old woman was referred to our department for surgical treatment of an abdominal aortic aneurysm (AAA) and a concurrent oropharyngeal tumor. During surgery to correct the AAA, we found a jejunal tumor incidentally and performed partial resection of the jejunum. Microscopically, the jejunal tumor showed dilated ducts containing intraluminal papillae lined with mucinous epithelium with low-grade cytological and architectural atypia within the pancreatic tissue. Immunohistochemical staining revealed MUC1 (-), MUC2 (-), MUC5AC (+), and MUC6 (-) proteins. To the best of our knowledge, only six cases of IPMN originating from a heterotopic pancreas have been reported in English, and this is the first report of an IPMN originating from a jejunal heterotopic pancreas.

Enhanced cancer metastasis in mice deficient in vasohibin-1 gene.

Vasohibin-1 (VASH1) is isolated as an endogenous angiogenesis inhibitor produced by the vascular endothelium. We previously reported that tumor growth and tumor angiogenesis were augmented in VASH1 (-/-) mice. Here we examined whether VASH1 plays any role in cancer metastasis. When Lewis lung carcinoma (LLC) cells were inoculated in the footpad to observe spontaneous metastasis, a significant increase in lung metastasis together with inguinal lymph node metastasis was evident in the VASH1 (-/-) mice. Histological analyses revealed that vessels of the footpad tumor in VASH1 (-/-) mice were more immature, having fewer mural cells. However, when LLC cells were injected into a tail vein, the extent of lung metastasis was unchanged between wild-type mice and VASH1 (-/-) mice. When VASH1 in endothelial cells in culture was knocked-down by siRNA, we observed a decrease in the content of ZO-1, a component of tight junctions, which decrease resulted in increased transmigration of cancer cells across the endothelial cell monolayer. These results indicate that endogenous VASH1 tightens the endothelial barrier and makes tumor vessels resistant to cancer metastasis.