The genetic polymorphisms of aldehyde dehydrogenase-2 (ALDH2), alcohol dehydrogenase-2 (ADH2), ADH3, and glutathione S-transferase M1 (GSTM1) influence the metabolism of alcohol and other carcinogens. The ALDH2*1/2*2 genotype, which encodes inactive ALDH2, and ADH2*1/2*1, which encodes the low-activity form of ADH2, enhance the risk for esophageal cancer in East Asian alcoholics. This case-control study of whether the enzyme-related vulnerability for esophageal cancer can be extended to a general population involved 234 Japanese men with esophageal squamous cell carcinoma and 634 cancer-free Japanese men who received annual health checkups. The GSTM1 genotype was not associated with the risk for this cancer. Light drinkers (1-8.9 units/week) with ALDH2*1/2*2 had an esophageal cancer risk 5.82 times that of light drinkers with ALDH2*1/2*1 (reference category), and their risk was similar to that of moderate drinkers (9-17.9 units/week) with ALDH2*1/2*1 (odds ratio = 5.58). The risk for moderate drinkers with ALDH2*1/2*2 (OR = 55.84) exceeded that for heavy drinkers (18+ units/week) with ALDH2*1/2*1 (OR = 10.38). Similar increased risks were observed for those with ADH2*1/2*1. A multiple logistic model including ALDH2, ADH2, and ADH3 genotypes showed that the ADH3 genotype does not significantly affect the risk for esophageal cancer. For individuals with both ALDH2*1/2*2 and ADH2*1/2*1, the risk of esophageal cancer was enhanced in a multiplicative fashion (OR = 30.12), whereas for those with either ALDH2*1/2*2 or ADH2*1/2*1 alone the ORs were 7.36 and 4.11. In comparison with the estimated population-attributable risks for preference for strong alcoholic beverages (30.7%), smoking (53.6%) and for lower intake of green and yellow vegetables (25.7%) and fruit (37.6%), an extraordinarily high proportion of the excessive risk for esophageal cancer in the Japanese males can be attributed to drinking (90.9%), particularly drinking by persons with inactive heterozygous ALDH2 (68.5%). Education regarding these risky conditions in connection with ALDH2 and ADH2 is vitally important in a new strategic approach aimed at preventing esophageal cancer in East Asians.

The genetic polymorphisms of aldehyde dehydrogenase-2 (ALDH2), alcohol dehydrogenase-1B (ADH1B, previously called ADH2), and ADH1C (previously called ADH3) affect the metabolism of alcohol. The inactive ALDH2 encoded by ALDH2*1/*2 and the less-active ADH1B encoded by ADH1B*1/*1 increase the risk of esophageal squamous cell carcinoma in East Asian drinkers. This case-control study involved 96 Japanese men with oral and pharyngeal squamous cell carcinoma (hypopharyngeal cancer in 43 patients and oral/oropharyngeal cancer in 53) and 642 cancer-free Japanese men. The risk of the cancers overall and of hypopharyngeal cancer was increased 3.61- and 10.08-fold, respectively, by ALDH2*1/*2 among moderate-to-heavy drinkers (9+ units/week; one unit = 22 g of ethanol), but the risk of oral/oropharyngeal cancer was not significantly affected by the ALDH2 genotype. The results obtained with a simple alcohol flushing questionnaire were essentially comparable with those obtained by ALDH2 genotyping. Among moderate-to-heavy drinkers, men with the less-active ADH1B*1/*1 had a significantly higher risk of the cancers overall, of hypopharyngeal cancer, and of oral/oropharyngeal cancer (OR = 5.56, 7.21 and 4.24, respectively). In view of the linkage disequilibrium between ADH1B and ADH1C, the ADH1C genotype does not significantly affect cancer risk. The significant independent risk factors for oral and pharyngeal cancer overall among moderate-to-heavy drinkers were inactive ALDH2*1/*2, less-active ADH1B*1/*1, frequent drinking of strong alcohol beverages straight, smoking, and lower intake of green-yellow vegetables. Educating these risks for cancer of the upper aerodigestive tract could be a useful new strategic approach to the prevention of these cancers in Japanese.

DW-MRI exhibits high diagnostic performance in bladder cancer with excellent objectivity. The ADC value could potentially serve as a biomarker to predict clinical aggressiveness in bladder cancer.

In order to elucidate the participation of L-cysteinesulphinate decarboxylase (CSD) in taurine synthesis in Japanese¯ounder, and the synthetic ability of taurine in other ®sh species, hepatic (or hepatopancreatic) CSD activities of several ®sh species were compared. Enzyme activity was determined by measuring the production of hypotaurine during an incubation of crude enzyme preparation with L-cysteinesulphinate as a substrate. HPLC was used for the analysis of hypotaurine. The enzyme activities of ®sh were lower than those of mammals. Japanese¯ounder Paralichthys olivaceus (Temminck et Schlegel) showed half the activity of rainbow trout (Oncorhynchus mykiss Walbaum). As activity was almost constant throughout the ®sh growth cycle, CSD does not seem to be responsible for low production of taurine in juvenile Japanese¯ounder. On the other hand, CSD activity was not present in yellowtail (Seriola quinqueradiata Temminck et Schlegel), blue®n tuna Thunnus thynus (Linnaeus) or skipjack (Katsuwonus pelamis (Linnaeus)). The inability to synthesize taurine and the possible dietary requirement for taurine is suggested in these ®sh species.

The requirement for taurine in juvenile Japanese flounder Paralichthys olivaceus was determined by feeding diets containing various levels of taurine and cystine. Test diets supplemented with 0.5, 1.0 and 1.5% of taurine or with 0.5, 1.0 and 1.5% of L‐cystine were prepared. The basal diet contained 55% protein from white fish meal. These diets were fed to juvenile Japanese flounder with an initial mean bodyweight of 0.9 g (total length (TL) 48 mm) for 5 weeks. Approximately 1.4% taurine content in the diet was required for optimum growth of juvenile flounder. A positive linear relationship was noted between the content of taurine accumulated in the muscle, liver and brain and the level of taurine in the diet. However, there was no increased taurine content in tissues of fish fed the cystine‐supplemented diet. In contrast, the fish fed control and cystine‐supplemented diets showed higher contents of cystathionine in the tissues. The concentration of cystathionine in tissues rapidly decreased with an increase of taurine in the diet. It was also observed that for each of the dietary groups, a trace amount of taurine was excreted. These results suggest that the taurine content in the diet affects the sulfur amino acid metabolism of juvenile Japanese flounder, and indicate that juvenile flounder are unable to biosynthesize taurine from cystine.