Development of a Questionnaire Method to Discriminate Between Typical and Atypical Genotypes of Low Km Aldehyde Dehydrogenase in a Japanese Population

Nearly half of all Orientals exhibit aversive symptoms, such as "Oriental flushing" or palpitation, during alcohol consumption. This high alcohol sensitivity among Orientals has been attributed to a highly prevalent polymorphism in low K_m aldehyde dehydrogenase (ALDH2). In the present study, we attempted to develop a reliable questionnaire method to probe the frequency of alcohol drinking-related symptoms to estimate the ALDH2 genotype. Four-hundred twenty-four male and 100 female workers provided blood samples for polymerase chain reaction analysis and completed the questionnaire. We performed a stepwise logistic regression analysis to discriminate between the typical homozygote ( ALDH2*1/*1 ) and the atypical heterozygote ( ALDH2*1/*2 ) in male subjects. Because of the limitation in the sample size for ALDH2*2/*2 , this genotype was not included in the analysis. Results revealed that only three symptoms (facial flushing, flushing elsewhere, and palpitation) were enough to correctly predict the ALDH2 genotypes in ∼89% of all subjects. The present questionnaire method ( AL cohol Sensitivity screening Test; ALST) takes a little time and effort for the genotype determination, and may be especially useful in epidemiological studies with a large sample size or with subjects from whom DNA samples are not available.     

Relevance of Both Daily Hassles and the ALDH2 Genotype to Problem Drinking among Japanese Male Workers

The effects of genetic polymorphisms in the ALDH2 and ADH2 genes and stress levels, as assessed by the daily hassles scale on the prevalence of problem drinkers, were investigated in males in a Japanese occupational population. The frequency of problem drinkers was estimated by the Kurihama Alcoholism Screening Test (KAST). The prevalence of those with a high KAST score (≥0.0) was significantly higher in ALDH2*1/*1 (18.4%) than in ALDH2*1/*2 (4.8%). Multiple logistic regression analysis revealed significant contributions by levels of alcohol consumption, the ALDH2 genotype, and daily hassles to the prevalence of those with a high KAST score. When we analyzed the data for each ALDH2 genotype, heavier alcohol consumption (≥28.8 ml/day), older age (≥40 years old), and very high daily hassles levels (≥20) significantly increased the prevalence of problem drinkers in ALDH2*1/*1. On the contrary, no variables other than heavier alcohol consumption influenced the prevalence in ALDH2*1/*2. In summary, the present study revealed significant contributions of both daily hassles and the ALDH2 genotype to the increase of problem drinkers in an occupational population. Health promotion activities to prevent from alcohol dependence should focus on ALDH2*1/*1 , especially those of middle age, and should include stress management as a part of their activities.     

Screening of Dihydropyrimidine Dehydrogenase Genetic Variants by Direct Sequencing in Different Ethnic Groups

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.     

Effect of Aldehyde Dehydrogenase 2 Gene Polymorphism on Hemodynamics After Nitroglycerin Intervention in Northern Chinese Han Population

Background:Nitroglycerin (NTG) is one of the few immediate treatments for acute angina.Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme in the human body that facilitates the biological metabolism of N...     

Identification of the Human P-450 Enzymes Responsible for the Sulfoxidation and Thiono-Oxidation of Diethyldithiocarbamate Methyl Ester: Role of P-450 Enzymes in Disulfiram Bioactivation

Diethyldithiocarbamate methyl ester (DDTC-Me) is a precursor to the formation of S-methyl-N,N-diethyliolcarbamate sulfoxide, the active metabolite proposed to be responsible for the alcohol deterrent effects of disulfiram. The present study investigated the role of human cytochrome P-450 (CYP) enzymes in sulfoxidation and thiono-oxidation of DDTC-Me, intermediary steps in the activation of disulfiram. Several approaches were used in an attempt to delineate the particular P-450 enzyme(s) involved in the sulfoxidation and thiono-oxidation of DDTC-Me. These approaches included the use of cDNA-expressed human P-450 enzymes, correlation analysis with sample-to-sample variation in human P-450 enzymes in a bank of human liver microsomes, and chemical and antibody inhibition studies. Multiple human P-450 enzymes (CYP3A4, CYPlA2, CYP2A6, and CYP2D6) catalyzed the sulfoxidation of DDTC-Me, as determined with cDNA-expressed enzymes. Several lines of evidence suggest that the sulfoxidation of DDTC-Me by human liver microsomes is primarily catalyzed by CYP3A4/5, including (1) a high correlation between DDTC-Me sulfoxidation and testosterone 6β-hydroxylation; (2) increased DDTC-Me sulfoxidation in the presence of α-naphthoflavone, an activator of CYP3A enzymes; (3) inhibition of this reaction by inhibitors of CYP3A4/5 enzymes, such as troleandomycin and ketoconazole; and (4) inhibition of DDTC-Mesulfoxidation by antibodies against CYP3A enzymes. On the other hand, several lines of evidence suggested that the thiono-oxidation of DDTC-Me by human liver microsomes is catalyzed in part by CYPlA2, CYP266, CYPPEl, and CYP3A4/5, including (1) these human P450 enzymes among others have the capacity to catalyze this reaction, as determined with cDNA-expressed enzymes; (2) a high correlation between DDTC-Me thiono-oxidation and testosterone 6β-hydroxylation, weak inhibition by ketoconazole, troleandomycin, and anti-CYP3A antibodies suggested a minor role for CYP3A4; (3) a high correlation with immunoreactive CYP2B6 suggested involvement of this enzyme; (4) weak inhibition of DDTC-Me thiono-oxidation by furafylline and anti-CYPlA antibody suggested involvement of CYPlA2, and (5) inhibition of DDTC-Me thiono-oxidation by DDTC and anti-CYP2E antibodies suggested a role for CYP2E1. Collectively, these data suggested CYP3A4/5 enzymes are the major contributors to the sulfoxidation of DDTC-Me by human liver microsomes, and CYPlA2, CYP2B6, CYP2E1, and CYP3A4/5 contribute toward DDTC-Me thiono-oxidation by human liver microsomes. This study, in conjunction with others (Madan et al., Drug Metab. Dispos. 23:1153–1162, 1995), may help explain the variability in disulfiram's effectiveness as an alcohol deterrent.     

Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

OBJECTIVE:

It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage.

METHODS:

We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student''s t-test.

RESULTS:

The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group.

CONCLUSION:

For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion.     

Subjective Feelings of Alcohol Intoxication in Asians with Genetic Variations of ALDH2 Alleles

Asian-American men who possess ALDH2*2 alleles and who experience a facial flush after consuming alcohol were carefully matched on drinking history and demographic variables with nonflushing Asian males with only ALDH2*1 alleles. Each man was tested following placebo and a challenge dose of 0.75 ml/kg alcohol. Following alcohol, flushers reported experiencing significantly more positive feelings of intoxication than nonflushers, despite equivalent blood alcohol concentrations. These data suggest that Asians who flush after drinking, particularly those with ALDH2*1/2*2 genotype, have a more intense, although not necessarily a more negative, response to alcohol than comparable nonflushing Asians. This alcohol sensitivity reaction that many Asian flushers experience may contribute to their lower tendency to drink excessively, even though their response to alcohol is not predominantly negative.     

Alcohol and aldehyde dehydrogenase gene polymorphisms influence susceptibility to esophageal cancer in Japanese alcoholics

BACKGROUND: Studies have consistently demonstrated that inactive aldehyde dehydrogenase-2 (ALDH2), encoded by ALDH2*1/2*2, is closely associated with alcohol-related carcinogenesis. Recently, the contributions of alcohol dehydrogenase-2 (ADH2) polymorphism to alcoholism, esophageal cancer, and the flushing response have also been described. METHODS: To determine the effects of ALDH2 and ADH2 genotypes in genetically based cancer susceptibility, lymphocyte DNA samples from 668 Japanese alcoholic men more than 40 years of age (91 with and 577 without esophageal cancer) were genotyped and the results were expressed as odds ratios (ORs). This study also tested 82 of the alcoholics with esophageal cancer to determine whether cancer susceptibility is associated with patients' responses to simple questions about current or former flushing after drinking a glass of beer. RESULTS: The frequencies of ADH2*1/2*1 and ALDH2*1/2*2 were significantly higher in alcoholics with, than in those without, esophageal cancer (0.473 vs. 0.289 and 0.560 vs. 0.099, respectively). After adjustment for drinking and smoking, the analysis showed significantly increased cancer risk for alcoholics with either ADH2*1/2*I (OR = 2.03) or ALDH2*1/2*2 (OR = 12.76). For those having ADH2*1/2*1 combined with ALDH2*1/2*2, the esophageal cancer risk was enhanced in a multiplicative fashion (OR = 27.66). Responses to flushing questions showed that only 47.8% of the ALDH2*1/2*2 heterozygotes with ADH2*1/ 2*1, compared with 92.3% of those with ALDH2*1/2*2 and the ADH2*2 allele, reported current or former flushing. Genotyping showed that for alcoholics who reported ever flushing, the questionnaire was 71.4% correct in identifying ALDH2*1/2*2 and 87.9% correct in identifying ALDH2*1/2*1. CONCLUSION: Japanese alcoholics can be divided into cancer susceptibility groups on the basis of their combined ADH2 and ALDH2 genotypes. The flushing questionnaire can predict high risk ALDH2*1/2*2 fairly accurately in persons with ADH2*2 allele, but a reliable screening procedure for the highest risk gene combination (ADH2*1/2*1 and ALDH2*1/2*2) will require further investigation.