Relationships between cigarette smoking, alcohol drinking, the ALDH2 genotype and adenomatous types of colorectal polyps in male self-defense force officials

Alcohol drinking as well as cigarette smoking has been associated with development of colorectal polyps, Asians such, as Japanese, Chinese and Korean have high frequency of genetic polymorphism in low Km aldehyde dehydrogenase (ALDH2) gene which greatly regulates alcohol intake. In the present study, we investigated associations of this polymorphism and lifestyles with colorectal polyps in self-defense forces personnels in Japan. All subjects received colonoscopy at a retirement health examination. The ALDH2 genotype was determined using polymerase chain reaction and restriction fragment length polymorphism method. Frequency of the ALDH2 genotype was not different between those with colorectal polyps (n=69) and those without the polyps (n=131). Smoking was associated with development of colorectal polyps (OR=4.7, 95% confidence interval=1.9-11.5) in the ALDH2 proficient genotype. The association appeared to be enhanced by drinking alcohol since a synergistic effect of smoking and alcohol drinking (> or =60 ml/day) was indicated (OR=9.9, 95% confidence interval=2.9-34.1) by logistic regression analysis. In the ALDH2 deficient genotype, however, we could not evaluate interactions of smoking and alcohol drinking on colorectal polyp development because of the small sample size of heavy alcohol drinkers. The genotype analysis would be useful in evaluating effects of environmental factors on outcomes for each genetically defined subpopulation.     

Cholecystectomy and the risk of colon cancer

Objective: The relationship between cholecystectomy and the occurrence of subsequent colon cancer has been controversial. Using data collected as part of an incident case-control study of colon cancer conducted in northern California, Minnesota, and Utah, we evaluated this association. Methods: Participants were between 30 and 79 yr of age and had a first primary colon cancer diagnosed between October 1, 1991 and September 30, 1994. Analyses were adjusted for age, gender, family history of colorectal cancer, body mass index, dietary energy and fiber intake, use of aspirin or nonsteroidal antiinflammatory drugs, and long-term leisure-time vigorous physical activity. Results: A weak positive association between cholecystectomy and proximal colon cancer (odds ratio [OR] and 95% confidence interval [CI] 1.3 [1.0–1.6]) was observed. This was counterbalanced by a weak, nonsignificant negative association (OR 0.8, 95% CI 0.6–1.1) with distal colon cancer leading to no overall association (OR 1.0, 95% CI 0.9–1.2). The association between colon cancer and cholecystectomy did not differ by gender or race, but it did differ by study area, with most of the increased association being attributed to the Minnesota population. The elevated risk of proximal colon cancer increased after cholecystectomy but disappeared after 14 years. Conclusions: Our results suggest that cholecystectomy or the underlying gallstone disease that prompts it may be related weakly to the risk of subsequent proximal colon cancer. However, the association may differ by geographic area of the country, and may be artifactual at least in part.     

Influence of the site of human gallbladder xenograft (Mz-ChA-1) on angiogenesis at the distant site

We reported that orthotopic xenograft of human gallbladder cancer (Mz-ChA-2) produced a greater amount of endogenous angiogenic inhibitory factors, however, only TGFbeta1 suppressed angiogenesis and tumor growth at the distant site (intracranium). The aim of this study was to confirm the validity of our previous findings that the site of the primary tumor would influence the angiogenesis in the distant site in a different xenograft of human gallbladder cancer (Mz-ChA-1). The growth rates, histology of the ectopic (flank) and orthotopic (gallbladder) xenografts, the plasma level of TGFbeta1, micro-circulation and angiogenesis in the distant site (intracranium) were estimated by size-measurement, hematoxylin and eosin staining, ELISA, intravital fluorescence microscopic observation and cranial window gel assay for angiogenesis. All experiments were performed in severe combined immunodeficient (SCID) mice. Orthotopic tumors grew faster and were less necrotic than ectopic tumors. Angiogenesis, vessel diameters, vessel density and leukocyte-rolling count in the distant site were significantly decreased in orthotopic tumor-bearing mice compared to those in either ectopic or no tumor-bearing mice. The plasma level of TGFbeta1 was significantly elevated in mice bearing orthotopic tumor as compared with ectopic and no tumor-bearing mice. Angiogenesis at the distant site was inhibited by the orthotopic xenograft of Mz-ChA-1 by the greatest amount of TGFbeta1 production. The results of the present study together with our previous study imply that the primary tumor microenvironment is conducive to the angiogenesis at a distant site by the production of the endogenous angiogenesis inhibitor TGFbeta1.     

Superoxide generation by snovial fluid neutrophils enhanced by immune complexes and suppressed by rheumatoid factor in synovial fluid

Summary Synovial fluid (SF) from patients with rheumatoid arthritis (RA) enhanced superoxide generation by neutrophils isolated from RA SF, in contrast to SF from patients with osteoarthritis. These superoxide generation-enhancing substances may be intermediate-sized immune complexes and a complement C5-derived fragment. Rheumatoid factor (RF) isolated from RA SF suppressed superoxide generation-enhancing activity of aggregated IgG. Therefore, biologically active RF may block the interaction of the immune complexes with neutrophils accumulating in RA SF, and protect the joint tissue from the effects of oxygen radicals or proteases.     

14C]Benzyl acetate is a potential radiotracer for the measurement of glial metabolism in the rat brain

In order to develop a suitable radiotracer for the measurement of glial metabolism, we synthesized four different types of ester derivatives of [¹⁴C]acetate, namely, [¹⁴C]phenyl acetate, [¹⁴C]para-nitrophenyl acetate, [¹⁴C]2,4-dinitrophenyl acetate and [¹⁴C]benzyl acetate ([¹⁴C]BA), and evaluated their potencies in rats. Among the derivatives, the highest brain uptake at 30 s postinjection was observed for [¹⁴C]BA, which was more than 23 times higher than that of [¹⁴C]acetate itself. A long-term retention of [¹⁴C]BA radioactivity in the brain was observed, whereas rapid clearance of radioactivity was seen in the heart. [¹⁴C]BA was rapidly hydrolyzed in the intact rat brain, and less than 5% of radiolabeled parent was observed 1 min after the injection. Radiochemical analysis using thin-layer chromatography revealed that [¹⁴C]BA was rapidly converted to [¹⁴C]glutamine and [¹⁴C]glutamate in the cortex within 10 min after injection. Furthermore, the uptake of [¹⁴C]BA was significantly decreased following microinjection of fluorocitrate, a selective glial toxin. These results strongly suggest that [¹⁴C]BA may be a useful radiotracer for the measurement of glial metabolism in the intact rat brain.     

Establishment and characterization of unique human gallbladder cancer cell lines

Gallbladder cancer has a dismal prognosis. Understanding the disease at the biological, genetic, molecular, cellular, and clinical level is essential for effective diagnostics and therapeutics. However, the currently established gallbladder cell lines are insufficient for better understanding and further research. The aim of our present study was to establish and characterize human gallbladder cancer cell lines. We established 5 cell lines from resected specimens of gallbladder cancers. These cell lines revealed typical tumor histopathological characteristics. We examined growth characteristics and the colony-forming ability of established cell lines in terms of their cell cycle parameters, expression of tumor markers (carcinoembryonic antigen; CEA, carbohydrated antigen 19-9; CA19-9, MUC-1 and c-kit) and the oncogene c-erbB2 by flow cytometer. Comparative genomic hybridization (CGH) analysis with specific gene probes was performed to detect changes in the gene copy numbers. Human origin of cell lines was confirmed by chromosomal analysis. Cells maintained differentiation characteristics of the original tumors. The doubling time of different cell lines varied from 30 to 96 h. All 5 cell lines formed colonies in the colony forming assays and expressed CEA, CA19-9, MUC-1 and the oncogene c-erbB2 and showed chromosomal aneuploidy. CGH analysis demonstrated gain of chromosomal region bearing SRC, RAB1, and PAP in all cell lines and hTERT in 4 cell lines. These newly established cell lines might serve as a useful model for studying the molecular pathogenesis of gallbladder cancer. Furthermore, they may serve as a model for testing new therapeutics against gallbladder cancer. These chromosomal aberrations and imbalances provide a starting point for molecular analyses of genomic regions and genes in gallbladder carcinogenesis.     

A case of gastric cancer with liver metastasis in which obstruction of the bile duct and choledocholithiasis was caused by intra-hepatic arterial infusion chemotherapy

A 64-year-old man underwent gastrectomy and partial liver resection for gastric cancer and liver metastasis, and was administered intra-arterial infusion chemotherapy for metastases of the remnant liver. This treatment was very effective against the liver metastases, but 13 months after the operation obstructive jaundice occurred. An examination revealed obstruction of the bile duct and choledocholithiasis. The choledocholithiasis was treated using a percutaneous transhepatic cholangio-scope, and choledocho-duodenostomy was performed for the obstruction of the bile duct. Findings from the operation suggested that the obstruction was caused by the intra-arterial infusion chemotherapy. At present, 2 years after the first operation, the patient is alive without the regrowth of the liver metastasis.     

Establishment and characterization of novel xenograft models of human biliary tract carcinomas

In order to develop new therapeutic regimens for biliary tract cancers, which carry dismal prognoses, the establishment of a human biliary tract cancer xenograft model is essential. Herein, we report the successful establishment and characterization of two xenograft models of human biliary tract cancers. An adenosquamous gallbladder cancer cell line (TGBC-44) and a bile duct adenocarcinoma cell line (TGBC-47) were obtained from fresh surgical specimens in our department and subcutaneously inoculated into nude mice. The overall tumor take rate was 100% and solid tumors grew measurable after 5 and 7 days for TGBC-44 and TGBC-47, respectively. Tumor doubling time was 3.9+/-1.1 and 4.1+/-0.5 days in the exponential growth phase in TGBC-44 and TGBC-47 xenografts, respectively. Isozyme test and karyotype analysis confirmed the human origin. Histopathology analysis revealed that the TGBC-44 xenograft retained both the squamous and the adenocarcinoma components, and the TGBC-47 xenograft exhibited poorly differentiated adenocarcinoma as in the corresponding original tumors. Immunohistochemistry and Western blotting studies revealed positive and similar expression of platelet derived endothelial growth factor/thymidine phosphorylase (PDGF/TP), thymidylate synthase (TS), and cyclooxygenase-2 (COX-2) in both original tumors and xenograft models. No macroscopic metastases were found at the time of sacrifice. We have successfully established two models of human biliary tract cancer, gallbladder and bile duct cancer. Models retained the morphological and biochemical characteristics of the original tumor and demonstrated constant biological behavior in all transplanted mice. These models could be useful tools for developing new diagnostic and therapeutic strategies against biliary tract cancers.