Akira Mitoro

Covered self-expandable metal stents with an anti-migration system improve patency duration without increased complications compared with uncovered stents for distal biliary obstruction caused by pancreatic carcinoma: a randomized multicenter trial.

OBJECTIVES:The requirements of biliary stents used in the palliation of malignant biliary obstruction are a long duration of patency and minimal adverse effects. Covered self-expandable metal stents (SEMSs) have been shown to prevent tumor ingrowth, which is the most frequent complication of uncovered SEMSs. However, because they are prone to migration, the superiority of covered SEMS has yet to be convincingly demonstrated. The aim of this study was to evaluate the superiority of covered over uncovered SEMSs in the palliation of distal biliary obstruction due to unresectable pancreatic carcinoma, using both stent types with relatively low axial force and uncovered flared ends to prevent their migration.METHODS:From April 2009 to December 2010, 120 patients who were admitted to 22 tertiary-care centers because of distal biliary obstruction from unresectable pancreatic carcinomas were enrolled in this prospective randomized multicenter study. Patients were randomly assigned to receive a covered or uncovered SEMS deployed at the site of the biliary stricture during endoscopic retrograde cholangiopancreatography. Stent patency time, patient survival time, patient survival time without stent dysfunction (time to stent dysfunction or patient death), cause of stent dysfunction (ingrowth, overgrowth, migration, or sludge formation), and serious adverse events were compared between covered and uncovered SEMS groups.RESULTS:Patient survival time in the two groups did not significantly differ (median: 285 and 223 days, respectively; P=0.68). Patient survival time without stent dysfunction was significantly longer in the covered than in the uncovered SEMS group (median: 187 vs. 132 days; P=0.043). Stent patency was also significantly longer in the covered than in the uncovered SEMS group (mean±s.d.: 219.3±159.1 vs. 166.9±124.9 days; P=0.047). Reintervention for stent dysfunction was performed in 14 of 60 patients with covered SEMSs (23%) and in 22 of 60 patients with uncovered SEMSs (37%; P=0.08). Stent dysfunction was caused by tumor ingrowth, tumor overgrowth, and sludge formation in 0 (0%), 3 (5%), and 11 (18%) patients in the covered SEMSs group, and in 15 (25%), 2 (3%), and 6 (10%) patients in the uncovered SEMSs group, respectively. Stent migration was not observed in either group. Rates of tumor overgrowth and sludge formation did not significantly differ between the two groups, whereas the rate of tumor ingrowth was significantly lower in the covered than in the uncovered SEMS group (P<0.01). Acute pancreatitis occurred in only one patient in the covered SEMS group. Acute cholecystitis occurred in one patient in the covered SEMS group and in two patients in the uncovered SEMS group. There was no significant difference between the two groups in the incidence of serious adverse events.CONCLUSIONS:By preventing tumor ingrowth and migration, covered SEMSs with an anti-migration system had a longer duration of patency than uncovered SEMSs, which recommends their use in the palliative treatment of patients with biliary obstruction due to pancreatic carcinomas.

Particle-mediated gene transfer into murine livers using a newly developed gene gun

Although particle-mediated gene transfer using gene gun technology has been applied for gene transfer into epidermis, applications of this technology to visceral tissues have not been well investigated. Although all helium gas-driven gene gun instruments have used macrocarriers to discharge DNA-coated microprojectiles so far, we used a newly developed gene gun instrument, in which a hammering bullet is used to discharge microprojectiles. With the gene gun, gold particles coated with lacZ expression plasmid were discharged to murine livers. LacZ expression was induced much more profoundly in the liver by particle-mediated gene transfer than by simple plasmid injection and electroporation-mediated gene transfer. LacZ expression was broadly and randomly distributed throughout the bombarded livers, indicating that particle-mediated gene transfer can induce transgene expression even at relatively distant areas from the surface of the bombarded tissue. Furthermore, although transgene expression was at its peak on day 2 after the bombardment, it was still detectable even on day 28. These results indicate that particle-mediated gene transfer with a newly developed gene gun may provide a new approach to gene therapy for human diseases.

Combination of vitamin K2 and angiotensin-converting enzyme inhibitor ameliorates cumulative recurrence of hepatocellular carcinoma.

BACKGROUND/AIMS No chemopreventive agent has been approved against hepatocellular carcinoma (HCC) yet. Since neovascularization plays a pivotal role in HCC, an angiostatic agent is considered as one of the promising approaches. The aim of this study was to elucidate the combined effect of the clinically used vitamin K(2) (VK) and angiotensin-converting enzyme inhibitor (ACE-I) on cumulative recurrence after curative treatment on a total of 87 patients, especially in consideration of neovascularization. METHODS VK (menatetrenone; 45 mg/day) and/or ACE-I (perindopril; 4 mg/day) were administered for 36-48 months after curative therapy for HCC. The cumulative recurrence and several indices were analyzed. RESULTS A 48-month follow-up revealed that the combination treatment with VK and ACE-I markedly inhibited the cumulative recurrence of HCC in association with suppression of the serum level of the vascular endothelial growth factor (VEGF); a central angiogenic factor. The serum level of lectin-reactive alpha-fetoprotein was also suppressed almost in parallel with VEGF. These beneficial effects were not observed with single treatment using VK or ACE-I. CONCLUSIONS The combination treatment of VK and ACE-I may suppress the cumulative recurrence of HCC after the curative therapy, at least partly through suppression of the VEGF-mediated neovascularization.

Assessment of efficiency and safety of adenovirus mediated gene transfer into normal and damaged murine livers

BACKGROUND When recombinant adenoviruses are infused directly into the circulation, transgene expression is almost completely restricted to the liver. AIMS Efficiency and safety of adenovirus mediated gene transfer into damaged livers were examined in mice with liver cirrhosis or fulminant hepatitis. METHODS Liver cirrhosis and fulminant hepatitis were induced by intraperitoneal administration of thioacetamide and d-galactosamine followed by lipopolysaccharide, respectively. Mice were infused with adenoviruses carrying the Escherichia coliβ-galactosidase gene, lacZ gene, into the tail vein. Transduction efficiency of thelacZ gene was estimated histochemically by X-gal staining and quantitatively using a chemiluminescent assay. Activation of adenovirus specific T cells and development of neutralising antibodies against adenovirus were also examined. RESULTS Histochemical evaluation revealed that approximately 40%, 80%, and 40% of cells in normal, cirrhotic, and fulminant hepatitis livers, respectively, were stained blue using X-gal staining. Quantitative analyses revealed that levels of lacZ expression in cirrhotic livers were approximately 2.5-fold and sixfold greater than those in normal and fulminant hepatitis livers, respectively. Although transgene expression in fulminant hepatitis livers was significantly lower than that in normal livers, marked levels of transgene expression were achieved even in fulminant hepatitis livers. Significant adverse effects of adenoviruses were not observed in damaged livers. There were no significant differences in cellular or humoral immune responses to adenoviruses among animals with normal, cirrhotic, and fulminant hepatitis livers. CONCLUSIONS Our results suggest that gene therapy with adenoviruses may be used efficiently and safely, even in patients with severe liver disease.

Randomised controlled trial of long-term maintenance corticosteroid therapy in patients with autoimmune pancreatitis

Objective Corticosteroid has been established as the standard therapy for autoimmune pancreatitis (AIP), but the requirement for maintenance corticosteroid therapy is controversial. We conducted a randomised controlled trial to clarify the efficacy of maintenance corticosteroid therapy in patients with AIP. Design We conducted a multicentre, tertiary setting, randomised controlled trial. After the induction of remission with the initial oral prednisolone (PSL) treatment, maintenance therapy with PSL at 5–7.5 mg/day was continued for 3 years or withdrawn at 26 weeks. The primary endpoint was relapse-free survival over 3 years and the secondary endpoint was serious corticosteroid-related complications. All analyses were performed on an intention-to-treat basis. Results Between April 2009 and March 2012, 49 patients with AIP were randomly assigned to the maintenance therapy group (n=30) or the cessation group (n=19). Baseline characteristics were not different between the two groups. Relapses occurred within 3 years in 11 out of 19 (57.9%) patients assigned to the cessation group, and in 7 of 30 (23.3%) patients in the maintenance therapy group. The relapse rate over 3 years was significantly lower in the maintenance therapy group than that in the cessation group (p=0.011). The relapse-free survival was significantly longer in the maintenance therapy group than that in the cessation group (p=0.007). No serious corticosteroid-related complications requiring discontinuation of PSL were observed. Conclusions Maintenance corticosteroid therapy for 3 years may decrease relapses in patients with AIP compared with those who discontinued the therapy at 26 weeks. Trial registration number UMIN000001818; Results.

Comparison of Gene Therapy with the Herpes Simplex Virus Thymidine Kinase Gene and the Bacterial Cytosine Deaminase Gene for the Treatment of Hepatocellular Carcinoma

BACKGROUND Bystander effects induced by suicide gene/prodrug systems play an essential role in achieving successful antitumor effects. Although it has been shown in several in vitro studies that the bacterial cytosine deaminase (CD) gene/5-fluorocytosine (5-FC) system is superior to the herpes simplex virus thymidine kinase (HSV-TK) gene/ganciclovir (GCV) system, we examined here which suicide gene system was more promising in vivo for the treatment of hepatocellular carcinoma (HCC). METHODS BNL1ME A.7R.1 murine HCC cells were retrovirally transduced with the HSV-TK or CD gene, and bystander effects caused by the appropriate prodrug treatment were examined not only in vitro but also in vivo. RESULTS The CD/5-FC system was superior to the HSV-TK/GCV system in HCC cell elimination in vitro. The bystander effect of the HSV-TK/GCV was shown to be substantially dependent on cell-to-cell contact, whereas that of the CD/5-FC was not. However, antitumor effects on HCC and tumor immunity to parental HCC induced by the HSV-TK/GCV system were not inferior and even superior to those induced by the CD/5-FC system. Bystander effects induced by the suicide gene/prodrug systems in immunocompetent syngeneic mice were much more profound than those induced in vitro. However, significant bystander effects were not observed in athymic nude mice. CONCLUSIONS These results suggest that both HSV-TK/GCV and CD/5-FC systems are useful for the treatment of HCC. The results also suggest that T-cell-mediated immune responses elicited by the suicide gene/prodrug systems play a substantial role in antitumor effects in vivo.

Hepatocellular carcinoma in an orthotopic mouse model metastasizes intrahepatically in cirrhotic but not in normal liver

Prognosis of hepatocellular carcinoma (HCC) still remains poor mainly because of intrahepatic metastasis. In the majority of cases, HCC is found in conjunction with liver cirrhosis. It is, therefore, of great importance to investigate the invasive and metastatic behavior of HCC in cirrhotic liver. To examine this, a liver cirrhosis model was produced by injecting thioacetamide i.p. into mice. Murine HCC cells were labeled with the fluorescent carbocyanine dye, DiI, and implanted directly under the capsule of cirrhotic and normal livers of syngeneic mice. DiI‐labeled HCC cells in the liver were observed under fluorescent and confocal microscopy. Histological analysis of cirrhotic and normal livers revealed that implanted HCC cells migrated to and invaded the adjacent periportal regions, but not the adjacent centrolobular areas. This characteristic behavior of HCC was more evident in cirrhotic liver than in normal liver. Furthermore, intrahepatic metastasis to unimplanted hepatic lobes was observed in cirrhotic liver as early as 7 days after implantation, while it was not detected in normal liver even 4 weeks later. Thus, an orthotopic animal model for HCC with cirrhosis described here may be suitable for investigating the invasive and metastatic behavior of HCC. Importantly, labeling tumor cells with a fluorescent dye before orthotopic implantation may be a convenient and useful method to investigate the invasive and metastatic behavior of various types of cancer. Int. J. Cancer 80:471–476, 1999.

Combination of branched-chain amino acids and angiotensin-converting enzyme inhibitor suppresses the cumulative recurrence of hepatocellular carcinoma: A randomized control trial

Insulin resistance (IR) is reportedly involved in the progression of hepatocellular carcinoma (HCC). Since neovascularization plays an important role in hepatocarcinogenesis and IR, an angiostatic therapy may be considered as one of the promising approaches for chemoprevention against HCC. The aim of the current study was to examine the combination effect of a clinically used branched-chain amino acid (BCAA) and an angiotensin-converting enzyme inhibitor (ACE-I), both reportedly possess anti-angiogenic and IR-improving activities, on the cumulative recurrence after curative therapy. BCAA granules (Livact; 12 g/day) and/or ACE-I (perindopril; 4 mg/day) were administered after the curative therapy for HCC, and several indices were analyzed. A 48-month follow-up revealed that the combination treatment with BCAA and ACE-I markedly inhibited the cumulative recurrence of HCC under IR conditions, whereas neither single treatment exerted a significant inhibition. The soluble form of the vascular endothelial growth factor (VEGF; a central angiogenic factor) receptor-2 (sVEGFR2) was significantly decreased only three months after the treatment without recurrence. We also observed that IR, determined by the homeostasis model assessment (HOMA-IR), was significantly improved by this regimen, indicating that an inhibitory effect was achieved, at least partly, by coordinated effects of anti-angiogenesis and IR improvement. In conclusion, since both BCAA and ACE-I are widely used in clinical practice with safety, this combination therapy may represent a potential new strategy for chemoprevention against IR-based HCC recurrence in the future. Moreover, sVEGFR2 may become a useful clinical predictive marker of this combination treatment.

Plasma ADAMTS13 activity parallels the APACHE II score, reflecting an early prognostic indicator for patients with severe acute pancreatitis.

Objective. Severe acute pancreatitis (SAP) frequently progresses to pancreatitis-associated multiorgan failure (MOF) with high mortality. Decreased plasma ADAMTS13 activity (ADAMTS13:AC) results in the accumulation of unusually large von Willebrand factor multimers (UL-VWFM) and the formation of platelet thrombi, ultimately leading to MOF. The purpose of the study was to investigate the potential role of ADAMTS13:AC in the severity of SAP. Material and methods. Plasma ADAMTS13:AC and its related parameters were sequentially determined in 13 SAP patients. ADAMTS13:AC was determined by the chromogenic act-ELISA. Results. Within 1 or 2 days after admission, ADAMTS13:AC was lower in SAP patients (mean 28%) than in healthy controls (99%), and gradually recovered in the 11 survivors but further decreased in the 2 non-survivors. Patients with higher sepsis-related organ failure assessment (SOFA) scores showed lower ADAMTS13:AC than those without these scores. The inhibitor against ADAMTS13 was undetectable. On day 1, von Willebrand factor antigen (VWF:Ag) was higher (402%, p<0.001) in SAP patients than in controls (100%). VWF:Ag gradually decreased in the survivors, except in the 3 patients needing a necrosectomy, but remained high in the non-survivors. ADAMTS13:AC was inversely correlated with the APACHE II score (r=−0.750, p<0.005), and increased plasma concentrations of interleukin 6 (IL-6) and IL-8 at admission. UL-VWFM-positive patients had lower ADAMTS13:AC and decreased serum calcium concentrations, but higher VWF:Ag and IL-8 concentrations than UL-VWFM-negative patients. Conclusions. Plasma ADAMTS13:AC was closely related to the APACHE II score. This intimate relationship may serve as an early prognostic indicator for SAP patients. The imbalance between decreased ADAMTS13:AC and increased UL-VWFM could contribute to SAP pathogenesis through enhanced thrombogenesis.

Immunomodulation with FK506 around the time of intravenous re-administration of an adenoviral vector facilitates gene transfer into primed rat liver

Although adenoviruses are an attractive vehicle for gene transfer into tissues including various tumors, in vivo adenoviral administration elicits a neutralizing antibody response which eliminates or substantially reduces the efficacy of subsequent treatments. Transiently immunosuppressive strategies at the time of initial adenoviral exposure have shown to prevent the formation of neutralizing antibodies and permit the successful adenoviral readministration in animals. Initial treatment in humans may, however, correspond to adenoviral readministration into animals, because the exposure to wild‐type adenoviruses is common in humans. In the present study, we infused Adex1CAlacZ adenoviruses carrying the lacZ gene into the tail vein of rats, and examined whether a transient treatment with the immunosuppressant FK506 around the time of i.v. readministration of adenoviruses could induce the re‐expression of the lacZ gene in animals primed with adenoviruses. Although i.v. infusion of adenoviruses carrying the lacZ gene resulted in transiently high levels of transgene expression in rat liver, i.v. reinfusion of adenoviruses failed to induce detectable levels of transgene expression. Conversely, when animals were treated transiently with FK506 around the time of adenoviral reinfusion, development of neutralizing antibodies and antigen‐specific T cell proliferation in response to adenoviral reinfusion were significantly suppressed, and re‐expression of the transgene was achievable. Int. J. Cancer 85:839–844, 2000.