Pancreatic tumor antigen in transplantable adenocarcinomas induced by N-bis(2-hydroxypropyl)nitrosamine in hamsters

An attempt was made to detect a pancreatic tumor antigen (PTA) in transplantable pancreatic adenocarcinomas induced by N-bis(2-hydroxypropyl)nitrosamine (DHPN) in hamsters. Antibody against antigenic protein was raised by immunizing rabbits with whole homogenate of the tumors transplanted into the back of hamsters. PTA was purified by affinity chromatography and shown to have the physicochemical properties of a glycoprotein with a molecular weight of 800,000, migrating in the beta regions upon agarose gel electrophoresis. Loss of immunological properties was observed after heating at 65 degrees C for 30 min. Enzyme immunoassay revealed that the levels of PTA in the serum and tissue showed a positive correlation with the induction of the presence of tumor, and size of the tumor. It is tentatively suggested that PTA values above 150 ng/ml serum are indicators of tumors, because in normal hamsters the PTA range is from 25 to 130 ng/ml serum. Immunohistochemically, PTA was demonstrated to be localized within the cytoplasm of epithelial tumor cells of well-differentiated tubular adenocarcinomas.

Induction of gamma-glutamyltranspeptidase-positive foci in rat liver by deoxycholic acid

Initiating activities of the secondary bile acids, deoxycholic acid (DCA) and lithocholic acid (LCA), were examined in terms of the induction of gamma-glutamyltranspeptidase (GGT)-positive foci in rat liver. A rapid induction model of enzyme-altered foci was utilized. GGT-positive foci were clearly induced by DCA ranging from 0.05% to 0.5% in the diet. In contrast, the induction of GGT-positive foci by LCA was less pronounced and was not dose-dependent. These results suggest that DCA possesses initiating activity.

Combined effects of cholecystectomy and lithocholic acid on pancreatic carcinogenesis of N-nitrosobis(2-hydroxypropyl)amine in Syrian golden hamsters

The effects of cholecystectomy and/or lithocholic acid (LCA) on the composition of biliary bile acid and on pancreatic carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine (BHP) were examined in male Syrian golden hamsters. Cholecystectomy was performed 1 wk before BHP initiation. BHP (250 mg/kg of body weight) was injected s.c. once a wk for 5 wk. A diet containing 0.5% LCA was begun 1 wk after the final BHP injection. All hamsters were sacrificed 36 wk after cholecystectomy, and the pancreas was examined histologically. Only the LCA treatment but no other treatment influenced the bile acid composition, i.e., the increase in LCA and decrease in cholic acid. The incidence of pancreatic carcinoma was 23 of 30 (76.7%) in hamsters receiving cholecystectomy plus BHP followed by LCA diet. The tumor incidence was five of 18 (27.8%) with BHP followed by basal diet, ten of 18 (55.6%) with cholecystectomy plus BHP followed by basal diet, and six of 18 (33.3%) with BHP followed by LCA diet, respectively. The total number of pancreatic carcinomas in hamsters receiving cholecystectomy and BHP followed by LCA diet also increased significantly. These results indicate that combined treatments of cholecystectomy and dietary LCA enhanced BHP-inducing pancreatic carcinogenesis in hamsters.

Effects of phenobarbital and secondary bile acids on liver, gallbladder, and pancreas carcinogenesis initiated by N-nitrosobis (2-hydroxypropyl)amine in hamsters

The effects of dietary administration of phenobarbital [(PB) CAS: 50-06-6] or the secondary bile acids, deoxycholic acid [(DCA) CAS: 83-44-3] and lithocholic acid [(LCA) CAS: 434-13-9], on tumorigenesis in the liver, gallbladder, and pancreas were investigated in male Syrian golden hamsters after carcinogenic initiation by N-nitrosobis(2-hydroxypropyl)amine [(BHP) CAS: 53609-64-6]. BHP [500 mg/kg (body wt)] was injected sc once weekly for 5 weeks. The animals were then maintained on a basal diet or a diet containing either 0.05% PB, 0.1% DCA, 0.5% DCA, or 0.5% LCA for 30 weeks. DCA enhanced the development of cholangiocarcinomas without influencing that of hepatocellular lesions. PB promoted the induction of hepatocellular carcinomas but not that of cholangiocarcinomas. LCA was without effect on the induction of either hepatocellular carcinomas or cholangiocarcinomas. DCA at a dose of 0.5% enhanced the induction of polyps in the gallbladder. Both DCA, at a dose of 0.1%, and LCA significantly enhanced the induction of pancreas carcinomas. PB had no effect on the induction of polyps in the gallbladder or of pancreas carcinomas. These data document that different tumors may be differentially promoted following initiation with a common carcinogen.

Comparative histochemical investigation of the glutathione S-transferase placental form and gamma-glutamyltranspeptidase during N-nitrosobis(2-hydroxypropyl)amine-induced pancreatic carcinogenesis in hamsters

Immunohistochemical staining using anti-rat glutathione S-transferase placental form (GST-P) rabbit antibody and enzyme histochemical staining for gamma-glutamyltranspeptidase (gamma-GT) were investigated in putative preneoplastic lesions and adenocarcinomas in the pancreas of Syrian golden hamsters treated with N-nitrosobis(2-hydroxypropyl)amine (BHP). Areas with ductular proliferation, ductal hyperplasia, and intraductal carcinoma were strongly positive for GST-P binding and negative for gamma-GT. Cystic adenoma, microcarcinoma, and carcinomas were constantly positively stained by GST-P and partially positive for gamma-GT. GST-P appears to be useful as a positive marker for putative preneoplastic lesions in pancreatic carcinogenesis. Since normal acinar cells are strongly positive for gamma-GT, the findings might suggest that acinar cells contribute to the development of cystic adenoma, microcarcinoma, and carcinomas.

Vascular changes associated with growth of primary and transplantable pancreatic adenocarcinomas induced in Syrian golden hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) and N-nitrosobis(2-hydroxypropyl)amine (BHP)

Microangiographic and histological methods were used to characterize vascular structure of primary and transplantable pancreatic adenocarcinomas induced by propylnitrosamines in Syrian golden hamsters. Originally of well-differentiated tubular morphology, serial transplantation subcutaneously to the back region was not associated with change in histopathological pattern or increase in invasive or metastatic potential. In contrast, pancreatic subserosal grafts displayed prominent invasion of surrounding tissues. Whereas primary tumors induced by N-nitrosobis(2-oxopropyl)amine (BOP) and those transplanted subserosally were characterized by hypovascularity, subcutaneous transplantation resulted in hypervascular tumors. Encasement, which is defined as invasion of normal arteries by the tumor, showing uneven caliber, irregular outline, appeared on earlier microangiographic findings rather than luminal irregularity, which is change of tumor vessels in neovascularization and occurs in tumor blood vessels subsequent to transplantation. The vascular component of subcutaneously transplanted tumors had a total vessel length ranging from 9.2 +/- 0.7 mm to 18.1 +/- 1.1 mm, a total vessel surface from 2.5 +/- 0.4 mm2 to 9.3 +/- 0.6 mm2 and a total vessel volume from 0.07 +/- 0.02 mm3 to 0.49 +/- 0.04 mm3, indicating that the vessels were of relatively large diameter and short length.

[Clinical studies on combination chemotherapy with fosfomycin and dibekacin in complicated urinary tract infection]

Clinical studies were performed on combination chemotherapy with Fosfomycin and Dibekacin. Sixteen patients with complicated urinary tract infections were treated with a combination of Fosfomycin (4 g/day, d.i.v.) and Dibekacin (200 mg/day, i.m.) for 5 days; and, 15 of them were clinically evaluated by criteria of UTI committee. The clinical effects proved excellent in 3 patients, good in 8 patients, and poor in 4 patients overall effective rate was 73.3%. Out of 19 strains isolated from the patients, 12 strains disappeared after the therapy. No side effect was observed in 16 cases. Clinical use of the combination chemotherapy with Fosfomycin and Dibekacin was thought to be effective and safe for patients with complicated urinary tract infections, because the combination acts not only synergistically, but also because Fosfomycin acts to protect against the nephrotoxicity induced by Dibekacin.