Inhibition of NADPH oxidase 4 activates apoptosis via the AKT/apoptosis signal-regulating kinase 1 pathway in pancreatic cancer PANC-1 cells.

Pancreatic adenocarcinoma is an aggressive human malignancy and is characterized by resistance to apoptosis. Recently, NADPH oxidase (Nox) 4-mediated generation of intracellular reactive oxygen species (ROS) was proposed to confer antiapoptotic activity and thus a growth advantage to pancreatic cancer cells. The signaling mechanism by which Nox4 transmits cell survival signals remains unclear. Here, we show that both a flavoprotein inhibitor, diphenylene iodonium (DPI), and small interfering RNAs designed to target Nox4 mRNA (siNox4RNAs) inhibited superoxide production in PANC-1 pancreatic cancer cells, and depletion of ROS by DPI or siNox4RNAs induced apoptosis. Parallely, DPI treatment and siNox4RNA transfection blocked activation of the cell survival kinase AKT by attenuating phosphorylation of AKT. Furthermore, AKT phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) on Ser-83 was reduced by DPI and siNox4RNAs. When ASK1Ser83Ala (an AKT phosphorylation-defective ASK1 mutant) was introduced into PANC-1 cells, this mutant alone induced apoptosis. But, addition of DPI or co-transfection of siNox4RNA had no additive effect, indicating that the mutant can substitute for these reagents in apoptosis induction. Taken together, these findings suggest that ROS generated by Nox4, at least in part, transmit cell survival signals through the AKT-ASK1 pathway in pancreatic cancer cells and their depletion leads to apoptosis.

Roles of virD4 and cagG genes in the cag pathogenicity island of Helicobacter pylori using a Mongolian gerbil model.

BACKGROUND AND AIMS: The roles of the virD4 and the cagG genes in the cag pathogenicity island of Helicobacter pylori for gastroduodenal pathogenesis are unclear and their roles in vivo have not been examined. METHODS: Seven week old male Mongolian gerbils were inoculated with the wild type H pylori TN2GF4, its isogenic virD4, or cagG mutants. Animals were sacrificed at 4, 12, and 24 weeks after inoculation. Gastric inflammation and H pylori density were evaluated by histology, inflammatory response (as measured by interleukin (IL)-1beta mRNA levels), proliferative activity (as assessed by 5'-bromo-2'deoxyuridine labelling indices), and host systemic reaction (as measured by anti-H pylori IgG antibody). RESULTS: Degree of gastric inflammation, proliferative activity, and mucosal IL-1beta mRNA levels remained low throughout the first 12 weeks in gerbils infected with the virD4 mutants. Degree of gastric inflammation and proliferative activity increased at 24 weeks with the virD4 mutants reaching levels comparative with those seen at four weeks with the wild-type strains. Mucosal IL-1beta mRNA levels were also increased at 24 weeks with the virD4 mutants and levels at 24 weeks were similar between the wild-type and virD4 mutants. In contrast, gerbils infected with the cagG mutants had reduced ability to colonise gerbils, and no or little gastric inflammation or proliferative activity was observed. CONCLUSIONS: Loss of the virD4 gene temporally retarded but did not abrogate gastric inflammation. Loss of the cagG gene abolished gastric inflammation partially via reduced ability to colonise gerbils. Unknown factors related to the type IV secretion system other than CagA may influence gastric inflammation.

Paradoxical role of Helicobacter pylori infection: protective effect against ethanol-induced gastric mucosal injury in Mongolian gerbils.

We investigated the effect of ethanol (a representative necrotizing agent) on gastritis induced by Helicobacter pylori infection in Mongolian gerbils. Seventy-eight gerbils were used. Four and 12 weeks after H. pylori inoculation, 30% ethanol was administered into the stomach. The stomachs were removed after 30 min, the intramucosal prostaglandin (PG) E2 concentration was measured, and histopathology was recorded. H. pylori infection caused chronic active gastritis, gastric erosion, hypersecretion of mucin from gland mucus cells, and a rise in the activity of intramucosal PGE2. After ethanol administration, gastric erosion was significantly less in animals infected with H. pylori than in uninfected animals. In conclusion, in the early stage of H. pylori infection, accentuation of intramucosal PGE2 and hypersecretion of mucin from gland mucus cells have a protective effect against gastric mucosal injury induced by necrotizing agents.

Duodenal atresia in dizygotic twins.

The authors report duodenal atresia occurring in both members of dizygotic twins who showed no signs of Down's syndrome, and both had normal chromosomal constitutions. They both had the two unlinked end type of atresia in the second portion of the duodenum, and direct end-to-end duodenoduodenostomy was carried out. Their postoperative courses were smooth, and both babies were discharged 32 days after birth. Their mother underwent pituitary adenoma removal and partial parathyroidectomy for multiple endocrine neoplasia (MEN-type I). She had been given hormonal supplement therapy after surgery and became pregnant after exogenous gonadotropin therapy. Environmental factors may be responsible for some cases of duodenal atresia.

Successful left trisegmentectomy for ruptured hepatoblastoma using intraoperative transarterial embolization.

Although surgical treatment with resection for spontaneous rupture of hepatoblastoma into the free abdominal cavity is difficult in small children, it may be the only treatment available. The authors describe a 16-month-old girl who showed a progressive decrease in hematocrit and no response to blood transfusion, after spontaneous rupture of a large hepatoblastoma that extended to the pubic bone. Percutaneous transcatheter arterial embolization could not be performed because selective catheterization was impossible. Therefore, emergency surgery was conducted. After intraoperative transcatheter arterial embolization (IOTAE) to control hemorrhage, left trisegmentectomy was performed. The patient then underwent chemotherapy, followed by autologous bone marrow transplantation. The hemorrhage from the ruptured tumor was completely arrested by IOTAE, and the postoperative course was uneventful. Hepatic resection after IOTAE, followed by chemotherapy and bone marrow transplantation, represents a promising treatment for ruptured hepatoblastoma.

Calculation of child and adult standard liver volume for liver transplantation.

Despite refinements in surgical techniques for liver transplantation, liver size disparity remains one of the most common problems in pediatric patients. Optimal liver graft size remains unknown and the volume of diseased liver in the recipient is not indicative of the volume (standard liver volume [LV]) optimal for the recipient's metabolic demands. To establish a formula for calculating the standard LV in the pediatric and adult populations for liver transplantation, whole LVs were measured using computed tomography (CT) in 96 patients (65 pediatric and 31 adolescent or adult subjects) with normal liver whose disease conditions did not seem to affect body weight (BW) or LV. In the 96 subjects, the ratio of estimated LV to BW decreased gradually as age increased until approximately 16 years, when it started to level off. On the other hand, there seemed to be a directly proportional relationship between the estimated LV in vivo and body surface area (BSA) (r = .981; r2 = .962; P < .0001) in the subjects as a whole, and the formula, LV (mL) = 706.2 x BSA (m2) + 2.4, was established from the measured data by simple regression analysis. Another predicting equation, LV (mL) = 2.223 x BW (kg)0.426 x body height (BH) (cm)0.682, was produced by multiple regression analysis (r2 = .969; P < .0001). Considering its simplicity of use, we adopted the first formula for predicting standard LV in an individual patient.

Partial liver transplantation from a living donor: experimental research and clinical experience.

Partial liver transplantation (PLTR) was studied experimentally, using 60 monkeys (20 recipients, 20 donors, 20 blood donors). The left lobe of the donors was transplanted orthotopically, using a veno-venous bypass catheter that was inserted in the portal vein and the other side passed through the hepatic portion of the inferior vena cava. The donor survival rate at 1 week was 70%. Seven recipients survived for more than 58 hours (58, 60, 64, 68, 72, 110, and 252 hours), and 13 died within 48 hours of surgery because of postoperative complications. Clinical living related liver transplantation (LRLT) was performed between June 1990 and March 1992 on six patients with biliary atresia and on one with liver cirrhosis and hepatocellular carcinoma. In all, the father's left lobe was transplanted orthotopically. Cyclosporine, azathioprine, and methyl prednisolone were administered. In addition, FK-506 was given to two patients in whom rejection was observed; one died 37 days after surgery because of acute rejection followed by systemic cytomegalovirus infection. The other six patients have survived for 8 to 29 months since transplantation. All six have been discharged from the hospital and are enjoying normal daily life. The postoperative course of all donors was uneventful. They were discharged 2 weeks after the operation and returned to their jobs in 2 months. The authors conclude that PLTR from a living donor is a promising therapeutic alternative to liver transplantation from a cadaver.

Effect of granulocyte colony-stimulating factor on neutropenia in liver transplant recipients with hypersplenism.

The authors present details of their initial experience with use of recombinant human granulocyte colony-stimulating factor (rhG-CSF) for preventing neutropenia caused by hypersplenism, and, possibly, for reducing the risk of postoperative infections in pediatric liver transplant recipients. Seven patients with end-stage liver disease, three of whom had severe hypersplenism, underwent living related liver transplantation (LRLT). The rhG-CSF was administered to the latter three patients. Peripheral neutrophil counts decreased immediately after reperfusion (to 1500 +/- 300/microL) in the three patients, and returned to normal with use of rhG-CSF 3 to 10 days after transplantation. The dosage was adjusted to maintain peripheral leukocyte and granulocyte counts above 5,000/microL and 2,000/microL, respectively. This initial clinical trial showed that rhG-CSF administration restores the leukocyte counts of patients who have hypersplenism, without any significant adverse effects, and that rhG-CSF holds promise for reducing the risk of infections after liver transplantation.

[Cyclosporine disposition in living related donor partial liver transplant recipients].

We studied the disposition of cyclosporine (CyA) in 8 living related donor partial liver transplant recipients (patient A-H). CyA blood levels were determined by fluorescence polarization immunoassay with specific monoclonal antibody (m-FPIA) and fluorescence polarization immunoassay with non-specific polyclonal antibody (p-FPIA). The ratio of the blood levels of CyA determined by p-FPIA to those by m-FPIA varied significantly, because the levels determined by p-FPIA were influenced by the function of graft liver. Thus, the levels of CyA determined by p-FPIA could not be used for the adjustment of CyA dose. The CyA dose ratios [DR; CyA blood level (mg/l)/dose (mg/kg)] of 3 in 8 patients were relatively large in 1-4 d after the transplant operation, however, it decreased within 2-5 d after the operation. CyA DR gradually increased from 5-8 d after the transplantation, and it reached to a maximum in 10-13 d in 5 patients to whom CyA was administered intravenously over 12 d after transplantation. The average ratio of DR in oral administration to that in intravenous one was about 43%. CyA bioavailability in the patient of living related partial liver transplantation was as usual as that in other organ transplant patient except for cadaveric liver transplant patients. The average DR of intravenous CyA administration in liver transplant recipients was 1.5 times larger than that in bone marrow transplant patients. CyA disposition had large inter-individual and intra-individual variation, and CyA blood level and DR varied in clinical time course at least within 1.5 month after operation. Therefore, it is necessary to measure CyA blood level frequently and to adjust CyA dose.

Liver regeneration in recipients and donors after transplantation.

Reduced-size liver grafts from related donors may not be of an optimal size for adequate function in the recipient. Therefore, liver-graft regeneration is clinically important. We evaluated liver regeneration by liver-volume determinations with serial computed tomography scans in four recipients (aged 9 months to 12 years) and their donors (all fathers of the recipients) after living-related liver transplantation. Standard liver volume was calculated from the recipient's body-surface area. In each recipient, the size of the transplanted liver tended to converge to the standard liver volume with time, regardless of whether initial liver-graft volume was smaller or larger than standard liver volume. In addition, transplanted liver in the recipient regenerated much faster than remnant liver in the donor, even though both consisted of the same hepatocytes, which suggests that regeneration is regulated mainly by factors other than the hepatocytes themselves.