Effect of Histamine H2 Receptor Antagonists on All-Cause Mortality in Critically Ill Patients With Essential Hypertension: A Retrospective Cohort Study

Previous studies found that histamine H2 receptor antagonists (H2RAs) had blood pressure lowering and cardioprotective effects, but the impact of H2RAs on the survival outcomes of critically ill patients with essential hypertension is still unclear. The aim of this study was to investigate the association of H2RAs exposure with all-cause mortality in patients with essential hypertension based on Medical Information Mart for Intensive Care III database. A total of 17,739 patients were included, involving 8482 H2RAs users and 9257 non-H2RAs users. Propensity score matching (PSM) was performed to improve balance between 2 groups that were exposed to H2RAs or not. Kaplan-Meier survival curves were used to compare the cumulative survival rates and multivariable Cox regression models were performed to evaluate the association between H2RAs exposure and all-cause mortality. After 1:1 PSM, 4416 pairs of patients were enrolled. The results revealed potentially significant association between H2RAs exposure and decreased 30-day, 90-day, and 1-year mortalities in multivariate analyses (HR = 0.783, 95% CI: 0.696-0.882 for 30-day; HR = 0.860, 95% CI: 0.778-0.950 for 90-day; and HR = 0.883, 95% CI: 0.811-0.961 for 1-year mortality, respectively). Covariate effect analyses showed that the use of H2RAs was more beneficial in essential hypertension patients with age ≥ 60, BMI ≥ 25 kg/m2, coronary arteriosclerosis, stroke, and acute kidney failure, respectively. In conclusion, H2RAs exposure was related to lower mortalities in critically ill patients with essential hypertension, which provided novel potential strategy for the use of H2RAs in essential hypertension patients.

The benefit of omeprazole exposure on all-cause mortality and length of ICU/hospital stay might vary with age in critically ill pediatric patients: A cohort study

PURPOSE

To investigate the association between proton pump inhibitors (PPIs) administration during hospitalization and mortality and length of stay in critically ill pediatric patients.

MATERIALS AND METHODS

This is a retrospective observational cohort study on pediatric ICU patients (0 to 18 years). Propensity score matching (PSM), Kaplan-Meier curves, Cox proportional hazards model and Linear regression model was applied for assessing the effects of PPIs on mortality and other outcomes during hospitalization.

RESULTS

A total of 2269 pediatric ICU patients were included, involving 1378 omeprazole (OME) users and 891 non-OME users. The results showed significant association between OME exposure and decreased ICU stay (β -0.042; 95% CI -0.073--0.011; P = 0.008) but prolonged non-ICU hospital stay (β 0.121; 95% CI 0.097-0.155; P = 0.040). No statistical significance was observed between OME exposure and reduced mortality, but the OME group had a slightly decreased tendency in 28-day mortality (HR 0.701; 95% CI 0.418-1.176) and in-hospital mortality (HR 0.726; 95% CI 0.419-1.257). Furthermore, subgroup analyses revealed that the decreased tendency of mortality were more obvious in patients less than 1 year old compared with older pediatric patients, although not statistically significant. In addition, we also observed that OME exposure was significantly associated with reduced mortality of general ICU subgroup.

CONCLUSIONS

This study provided a sign that PPIs used only in the ICU, rather than throughout hospital stay, might provide more benefit for critically ill pediatric patients. Additionally, younger pediatric patients might gain relatively more benefit than older children when receiving PPIs.

Histamine H2 receptor antagonist exhibited comparable all-cause mortality-decreasing effect as β-blockers in critically ill patients with heart failure: a cohort study

Background: Our previous study reported that histamine H2 receptor antagonists (H2RAs) exposure was associated with decreased mortality in critically ill patients with heart failure (HF) through the same pharmacological mechanism as β-blockers. However, population-based clinical study directly comparing the efficacy of H2RAs and β-blockers on mortality of HF patients are still lacking. This study aims to compare the association difference of H2RAs and β-blockers on mortality in critically ill patients with HF using the Medical Information Mart for Intensive Care III database (MIMIC-III). Methods: Study population was divided into 4 groups: β-blockers + H2RAs group, β-blockers group, H2RAs group, and Non-β-blockers + Non-H2RAs group. Kaplan-Meier curves and multivariable Cox regression models were employed to evaluate the differences of all-cause mortalities among the 4 groups. Propensity score matching (PSM) was used to increase comparability of four groups. Results: A total of 5593 patients were included. After PSM, multivariate analyses showed that patients in H2RAs group had close all-cause mortality with patients in β-blockers group. Furthermore, 30-day, 1-year, 5-year and 10-year all-mortality of patients in β-blockers + H2RAs group were significantly lower than those of patients in β-blockers group, respectively (HR: 0.64, 95%CI: 0.50-0.82 for 30-day; HR: 0.80, 95%CI: 0.69-0.93 for 1-year mortality; HR: 0.83, 95%CI: 0.74-0.93 for 5-year mortality; and HR: 0.85, 95%CI: 0.76-0.94 for 10-year mortality, respectively). Conclusion: H2RAs exposure exhibited comparable all-cause mortality-decreasing effect as β-blockers; and, furthermore, H2RAs and β-blockers had additive or synergistic interactions to improve survival in critically ill patients with HF.

A meta-analysis of associations of IL-10 gene polymorphisms with acute leukemia susceptibility

BACKGROUND

Recently, increasing evidence has demonstrated that IL-10 single nucleotide polymorphisms (SNPs) are associated with the risk of acute leukemia (AL), but the findings of different articles remain controversial. Thus, we performed a meta-analysis to further investigate the exact roles of IL-10 SNPs in AL susceptibility.

METHODS

Six common Chinese and English databases were utilized to retrieve eligible studies. The strength of the association was assessed by calculating odds ratios and 95 % confidence intervals. All analyses were carried out using Review Manager (version 5.3) and STATA (version 15.1). The registered number of this research is CRD42022373362.

RESULTS

A total of 6391 participants were enrolled in this research. The results showed that the AG genotype of rs1800896 increased AL risk in the heterozygous codominant model (AG vs. AA, OR = 1.41, 95 % CI = 1.04-1.92, P = 0.03) and overdominant model (AG vs. AA + GG, OR = 1.32, 95 % CI = 1.04-1.70, P = 0.03). In the subgroup analysis, associations between the G allele, GG genotype, AG genotype, AG + GG genotype of rs1800896 and increased AL risk were also observed in the mixed population based on allelic, homozygote codominant, heterozygous codominant, dominant, and overdominant models. Furthermore, an association between the AC genotype of rs1800872 and increased AL risk was observed in the Caucasian population in the overdominant model. However, the rs1800871, rs3024489 and rs3024493 polymorphisms did not affect AL risk.

CONCLUSION

IL-10 rs1800896 and rs1800872 affected the susceptibility of AL and therefore may be biomarkers for early screening and risk prediction of AL.

Effectiveness and Safety of Histamine H2 Receptor Antagonists: An Umbrella Review of Meta-Analyses

Histamine H2 receptor antagonists (H2RAs) were widely used to inhibit gastric acid secretion, but its association with adverse events remains controversial and unclear. We conducted an umbrella review of meta-analyses to systematically assess the quality and credibility of the correlations between H2RA use with the risk of adverse outcomes through searching 4 major databases from inception to April 30, 2022. Forty-six individual meta-analyses were identified, including 29 meta-analyses of observation studies with 32 unique outcomes and 19 meta-analyses of randomized controlled trials with 3 unique outcomes for comparing the H2RA versus non-H2RA group. A Measurement Tool to Assess Systematic Reviews 2 rating for the included meta-analyses showed that 4 of 46 meta-analyses were assigned as high scores, 3 were assigned as "moderate," and 25 were assigned as low scores. Grading of Recommendations Assessment, Development and Evaluation assessment for combined results demonstrated that 6 outcomes were rated as "moderate," 9 outcomes were rated as "low," and 17 outcomes were rated as "very low." We confirmed significant associations of H2RA use with pneumonia, peritonitis, necrotizing enterocolitis, Clostridium difficile infection, liver cancer, gastric cancer, and hip fracture diseases. No associations for colorectal cancer, melanoma, kidney cancer, lung cancer, or common reproductive system cancer or renal, neurological, and cardiovascular system diseases were observed. We found a variety of evidence for the associations between H2RAs and adverse outcomes, which would give clinicians more positive guidance on prescription of H2RAs in clinical practice.

Comparative efficacy and safety of uricosuric agents in the treatment of gout or hyperuricemia: a systematic review and network meta-analysis

OBJECTIVES

The current world witnesses a greatly increased prevalence and incidence of hyperuricemia and gout with unfortunately the comparative efficacy and safety of present available uricosuric agents remaining uncertain. We herein aimed to investigate the most appropriate uricosuric agent for gout or hyperuricemia patients.

METHOD

PubMed, Embase, Cochrane Library databases, and ClinicalTrials.gov from inception to 2 July 2022 were searched to retrieve eligible studies assessing efficacy and safety of uricosuric drugs in hyperuricemia or gout patients. Network meta-analysis was carried out using the Stata 16.0 software.

RESULTS

Twelve randomized controlled trials comprising 1851 patients were eventually included. Network meta-analysis showed that dotinurad 4 mg once daily, verinurad, dotinurad 2 mg once daily, dotinurad 1 mg once daily, and benzbromarone were the top 5 effective treatments to achieve target serum uric acid. Furthermore, dotinurad 4 mg once daily was more effective at achieving urate-lowering targets (RR of dotinurad 4 mg once daily vs. probenecid: 1.68, 95% CI [1.13; 2.50]) and safer (RR of probenecid vs. dotinurad 4 mg once daily: 1.77, 95% CI [0.69; 4.56]) than probenecid.

CONCLUSIONS

This network meta-analysis demonstrated an important absolute benefit of dotinurad 4 mg once daily to achieve target serum uric acid and low risk of adverse events for drug treatment of gout or hyperuricemia patients. Additionally, verinurad might be used as an alternative uricosuric therapeutic option to dotinurad. These findings provided further comprehensive insight into the treatment value of current uricosuric agents for gout or hyperuricemia. Key Points 1. This is the first systematic review and network meta-analysis examining the efficacy and safety of currently available uricosuric agents in gout or hyperuricemia patients. 2. Recommended doses of dotinurad 4mg once daily used for the treatment of gout or hyperuricemia patients can significantly decrease serum uric acid levels. 3. The present findings will provide further comprehensive insight into the treatment value of certain uricosuric agents for gout or hyperuricemia.

The pyroptosis-related gene signature predicts prognosis and reveals characterization of the tumor immune microenvironment in acute myeloid leukemia

Background: Pyroptosis is a novel inflammatory form of programmed cell death and a prospective target for cancer therapy. Nevertheless, little is known about the association between pyroptosis-related genes (PRGs) and acute myeloid leukemia (AML) prognosis. Herein, we systematically investigated the specific functions and clinical prognostic value of multiple PRGs in AML.

Methods: Univariate and LASSO Cox regression analyses based on TCGA and GTEx databases were used to generate the PRG signature, whose predictive efficacy of survival was evaluated using survival analysis, ROC, univariate and multivariate Cox analyses as well as subgroup analysis. The BeatAML cohort was used for data validation. The association between risk score and immune cell infiltration, HLA, immune checkpoints, cancer stem cell (CSC), tumor mutation burden (TMB), and therapeutic drug sensitivity were also analyzed.

Results: Six -PRG signatures, namely, CASP3, ELANE, GSDMA, NOD1, PYCARD, and VDR were generated. The high-risk score represented a poorer prognosis and the PRG risk score was also validated as an independent predictor of prognosis. A nomogram including the cytogenetic risk, age, and risk score was constructed for accurate prediction of 1-, 3-, and 5-year survival probabilities. Meanwhile, this risk score was significantly associated with the tumor immune microenvironment (TIME). A high-risk score is characterized by high immune cell infiltration, HLA, and immune checkpoints, as well as low CSC and TMB. In addition, patients with low-risk scores presented significantly lower IC50 values for ATRA, cytarabine, midostaurin, doxorubicin, and etoposide.

Conclusion: Our findings might contribute to further understanding of PRGs in the prognosis and development of AML and provide novel and reliable biomarkers for its precise prevention and treatment.

Associations of FOXP3 gene polymorphisms with susceptibility and severity of preeclampsia: A meta-analysis

OBJECTIVE

FOXP3 single nucleotide polymorphisms (SNPs) were recently elucidated to influence the development of preeclampsia (PE), but the results on this issue still remained controversial. Thus, a meta-analysis was implemented to systematically investigate the roles of FOXP3 SNPs in PE.

METHODS

Eligible publications were identified by retrieving relevant electronic databases. Meanwhile, the association intensity was estimated by calculating odds ratios (ORs) and 95% confidence intervals (CIs) in various genetic models.

RESULTS

Totally eight investigations involving 3446 subjects were enrolled in the final meta-analysis. The AC and AC + CC genotypes of FOXP3 rs3761548 were related to the susceptibility of PE in over-dominant (OR = 1.19, 95%CI = 1.02-1.38, P = 0.03) and recessive (OR = 0.59, 95% CI: 0.36-0.97, P = 0.04) models. Furthermore, correlation between rs2232365 and PE was observed in recessive model (GG vs. GA + AA) (OR = 0.79, 95%CI: 0.65-0.97, P = 0.03). Moreover, rs2232365 GA and GG + GA genotypes were associated with the severity of PE. However, rs4824747, rs3761547 and rs2280883 polymorphisms had no significant impact on PE susceptibility.

CONCLUSIONS

FOXP3 rs3761548 and rs2232365 SNPs influenced the PE susceptibility and therefore may be potential biomarkers for prediction of PE risk.

Association between TNF-α gene polymorphisms and susceptibility of myelodysplastic syndromes: a meta-analysis

OBJECTIVE

Myelodysplastic syndromes (MDS) constitute a heterogeneous group of clonal hematological diseases. Previous investigations reported that tumor necrosis factor-alpha (TNF-α) gene polymorphisms were associated with MDS susceptibility, but the results remained controversial. Thus, we conducted a meta-analysis to higher elucidate the correlation between TNF-α gene polymorphisms and MDS susceptibility.

METHODS

The PubMed, Cochrane Library, Embase, Chinese National Knowledge Infrastructure (CNKI), and Wan Fang databases were searched for eligible literatures published up to July 2021. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were applied to evaluate the strength of association.

RESULTS

Eight studies involving 1180 MDS patients and 1387 controls were included in this meta-analysis. For the TNF-α G308A polymorphism, we confirmed that the G allele (G versus A: P = 0.001), GG genotypes (GG versus GA: P = 0.005; GG versus GA + AA: P = 0.002), and GG + AA genotypes (GG + AA versus GA: P = 0.008) was significantly associated with decreased MDS susceptibility according to different genetic models. Furthermore, the G308A polymorphism was significantly correlated with decreased occurrence risk of MDS in the Caucasian population as compared with Asians in the above four genetic models (P < 0.05). However, no significant association was observed between the TNF-α G238A polymorphism and MDS risk.

CONCLUSION

This research showed that TNF-α G308A polymorphism might be a potential biomarker in early clinical screening of MDS, which would contribute to improving the individualized prevention of MDS patients in clinic.

PARP1 as a prognostic biomarker for human cancers: a meta-analysis

Aim: A comprehensive meta-analysis was carried out to evaluate the association between high PARP1 expression and clinical outcomes in diverse types of cancers. Materials & methods: The electronic databases for all articles about PARP1 expression and cancers were searched. Additionally, bioinformatics analysis was utilized to validate the results of the meta-analysis. Results: Fifty-two studies with a total of 7140 patients were included in the current meta-analysis. High PARP1 expression was found to be significantly associated with poor overall survival and recurrence in various cancers, which were further strengthened and complemented by the results of bioinformatic analysis. Furthermore, increased PAPR1 expression was also related to clinicopathological features. Conclusion: Our findings confirmed that PARP1 might be a promising biomarker for prognosis in human cancers.

Association of ABCB1 polymorphisms with carbamazepine metabolism and resistance in epilepsy: A meta-analysis

OBJECTIVE

ABCB1 polymorphisms were previously demonstrated to be associated with the metabolism and resistance of carbamazepine (CBZ) in epilepsy, but the results still remained controversial. Therefore, we performed this meta-analysis to further evaluate the impacts of ABCB1 polymorphisms on CBZ metabolism and resistance.

METHODS

The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure, Chinese Science and Technique Journals Database and Wan Fang Database were searched for eligible publications up to 5 July 2021. The mean difference (MD), Odds ratio (OR) and 95 % confidence interval (CI) were calculated by Review Manager 5.3 software to assess the strength of the association.

RESULTS

Twelve studies involving 2126 epilepsy patients were included in this meta-analysis. We found that the TC genotype (heterozygous model: TC vs. CC) of rs1045642 polymorphism was significantly connected with decreased CBZ concentration. Furthermore, this polymorphism was indicated to be associated with concentrations of carbamazepine-10, 11-epoxide (homozygote model: TT vs. CC; heterozygous model: TC vs CC; dominant model: TT + TC vs. CC; over-dominant model: TC vs. TT + CC) and carbamazepine-10, 11-trans dihydrodiol (heterozygous model: TC vs. CC; dominant model: TT + TC vs. CC). Moreover, the AG genotype of rs2032582 polymorphism was related to increased CBZ concentration in heterozygous (AG vs. GG), dominant (AA + AG vs. GG) and over-dominant (AG vs. AA + GG) models. Additionally, rs1128503 was associated with CBZ resistance in heterozygous model (TC vs. CC).

CONCLUSIONS

ABCB1 rs1045642 and rs2032582 polymorphisms were associated with CBZ metabolism for epilepsy, and rs1128503 was related to CBZ resistance. These findings would contribute to improving individualized therapy of epileptic patients.

[The association between Cathepsin S and pulmonary function and CT phenotypes in patients with chronic obstructive pulmonary disease]

Objective: To explore the value of cathepsin S in the bronchoalveolar lavage fluid (BALF) of patients with chronic obstructive pulmonary disease (COPD) in the evaluation of pulmonary function and CT phenotypes. Method: From April 2014 to April 2017, 46 patients with stable COPD were enrolled, and 29 healthy volunteers served as the control group. The patients were divided into 4 subgroups: GOLD Ⅰ(n=12), GOLD Ⅱ(n=6), GOLD Ⅲ(n=14), GOLD Ⅳ(n=14). The levels of cathepsin S and IFN-γ in BALF were determined by enzyme-linked immunosorbent assay (ELISA). The percentage ratio of low attenuation area to total lung area (LAA%), two times the ratio of airway wall thickness to outer diameter(2T/D), and the ratio of wall area to total cross-sectional area (WA) were measured by HRCT. Results: There were significant differences in the levels of cathepsin S in BALF between the groups (F=6.639, P=0.000). BALF cathepsin S levels were as follows: GOLD Ⅳ grou P>GOLD Ⅲ grou P>GOLD Ⅱ grou P>GOLD group Ⅰ >healthy control group (P value were all<0.05); LAA grade 3>LAA grade 2>LAA grade 1>LAA grade 0 (P value were all<0.05). Correlation analysis showed that BALF cathepsin S levels were correlated negatively with FEV(1)/FVC, FEV(1)% predicted, and DLCO% (r value was -0.065、-0.576、-0.392, respectively, P value were all<0.05), and but positively with RV/TLC%, LAA%, 2T/D, WA and IFN-γ(r value was 0.695, 0.497, 0.142, 0.309, 0.148, respectively, P value were all<0.05). Conclusion: The levels of cathepsin S were associated with the degree of airflow limitation and emphysema phenotype in COPD.

Associations between UGT2B7 polymorphisms and cancer susceptibility: A meta-analysis

BACKGROUND

UGT2B7 was recently acknowledged as a new critical enzyme involved in biotransformation of a variety of carcinogens, whose function was reported to be significantly associated with its encoding gene (UGT2B7) polymorphisms. However, results regarding the associations between single nucleotide polymorphisms (SNPs) of UGT2B7 and cancer risk still remained controversial. Therefore, a meta-analysis was conducted to further elucidate the role of UGT2B7 SNPs on cancer susceptibilities.

METHODS

PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure (CNKI), Technology of Chongqing (VIP) and Wan Fang Database were searched for eligible studies until March 2019. All analysis was carried out using the Review Manager 5.3 software. Subgroup analyses were performed by cancer types, ethnicity or source of controls.

RESULTS

13 studies with a total of 7688 cancer cases and 11,281 controls were included in this meta-analysis. The results showed that UGT2B7 rs7439366 increased the colorectal cancer risk in dominant model (OR = 0.76, 95% CI = 0.61-0.95, P = 0.02). However, as for the rs7435335 and rs12233719, we did not find their associations with cancer risk in all genetic models. In addition, the rs7441774 was found to be associated with breast cancer risk and significantly reduced papillary thyroid cancer risk in rs3924194 was also observed. Nevertheless, these findings remained to be further proven in future studies since these 2 SNPs were only respectively involved in 1 study.

CONCLUSION

This meta-analysis confirmed the association of UGT2B7 rs7439366 with colorectal cancer risk, which may be a potential promising biomarker for prediction of colorectal cancer risk.

[Correlation analysis of serum secreted frizzled-related protein 5 levels with airway inflammation and insulin resistance in chronic obstructive pulmonary disease patients]

Objective: To investigate the relationship between serum secreted frizzled-related protein 5(sfrp5) levels, insulin resistance, and airway inflammation in patients with chronic obstructive pulmonary disease(COPD). Method: A total of 178 COPD patients visiting our respiratory outpatient clinic from February 2015 to January 2017 were enrolled, and 99 healthy control subjects from the same time period were selected. Serum sfrp5 levels were compared between the 2 groups. Serum sfrp5 and inflammatory cytokines in induced sputum were observed in the 4 subgroups: insulin resistant COPD group [homeostasis model assessment of insulin resistance (HOMA-IR)≥2.29], non-insulin resistant COPD group, non-COPD insulin resistant group, and healthy control group. Results: Serum sfrp5 levels were found to be significantly higher in the COPD group as compared to the healthy control group (t=-14.29, P<0.001). Serum sfrp5 levels in the insulin resistant COPD group [(8±3)ng/ml] were significantly lower than that of the non-insulin resistant COPD group [(10±5)ng/ml], non-COPD insulin resistant group [(13±3)ng/ml], and normal control group [(14±4)ng/ml, F=35.85, P<0.01]. The insulin resistant COPD group had higher levels of In(Homa-IR), as well as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in induced sputum as compared to the non-insulin resistant COPD group, non-COPD insulin resistant group, and healthy control group (F values were 64.968, 41.40, 64.15, respectively, P value <0.01 for all items). The non-insulin resistant COPD group had higher levels of In(HOMA-IR) as well as TNF-α and IL-6 in induced sputum as compared to the non-COPD insulin resistant group and healthy control group. FEV(1)/FVC and FEV(1)% predicted were significantly lower in the insulin resistant COPD group as compared to those of non-insulin resistant COPD group and non-COPD insulin resistant group, and healthy control group (F values were 2.481 and 8.37, respectively, P value<0.05 for all items). FEV(1)/FVC and FEV(1)% predicted were significantly lower in the non-insulin resistant COPD group as compared to those of the healthy control group and non-COPD insulin-resistant group. Serum sfrp5 levels were positively correlated to FEV(1)/FVC and FEV(1) predicted (r values were 0.466 and 0.412, respectively; P values were <0.001 and 0.007, respectively) and inversely correlated to In(HOMA-IR) and TNF-α and IL-6 in induced sputum (r values were -0.304, -0.459, -0.517, respectively; P values were <0.001, 0.002, <0.001, respectively). BMI, ln(HOMA-IR), and IL-6 in induced sputum were independent related factors (r(2) values were 0.286, 0.176, 14.69, respectively; P values were <0.01 for all items) Conclusion: Sfrp5 may be concurrently associated with COPD and insulin resistance; insulin resistance may be associated with airway inflammation and airflow limitation. Sfrp5 may be involved in the development of COPD and may be the key link by which insulin resistance exerts its effects on airway inflammation.

Corrigendum PKR and HMGB1 expression and function in rheumatoid arthritis - Genet. Mol. Res. 14 (4): 17864-17870

Published online: December 22, 2015 (DOI: 10.4238/2015.December.22.11). Corrected after publication: June 3, 2016 (DOI: 10.4238/gmr.150267861). The correction is only in the name of the last author and should be: W.J. Wang, S.J. Yin and R.Q. Guo.

PKR and HMGB1 expression and function in rheumatoid arthritis

The pathogenesis of rheumatoid arthritis (RA) is characterized by inflammation. We aimed to examine the roles of double-stranded RNA-activated protein kinase (PKR) and high-mobility group box chromosomal protein 1 (HMGB1) in a rat model of RA. Male SD rats were divided into three groups: control, RA model, and intervention (RA model plus treatment). The model of RA was made by injecting Freund's adjuvant into the posterior right limb of the rat and the intervention group received a PKR-specific inhibitor C16 after RA modeling. The degree of limb swelling was measured following RA modeling and intervention. In addition, plasma levels of HMGB1 were determined using ELISA. The mRNA and protein levels of PKR and HMGB1 were detected in rat synovium using quantitative PCR and western blot, respectively. The degree of limb swelling in the RA model was increased compared to control, while it was decreased in the intervention model compared to the RA model. Plasma HMGB1 levels in the model group were significantly higher compared to the control group but were lower in the intervention group compared to the model group. PKR and HMGB1 protein and mRNA levels in the rat synovium were elevated in the model group and markedly reduced in the intervention group. Increased levels of PKR and HMGB1 in synovium or blood appear to be involved in the occurrence and development of RA in a rat model. Selective inhibition of PKR improves the symptoms of RA, perhaps by inhibiting the release of HMGB1.

Associations of polymorphisms in histidine decarboxylase, histamine N-methyltransferase and histamine receptor H3 genes with breast cancer

We previously found that genetic polymorphisms in gene coding for histamine H₄ receptors were related to the risk and malignant degree of breast cancer. The roles of polymorphisms in other histamine-related genes, such as histidine decarboxylase (HDC), histamine N-methyltransferase (HNMT) and histamine H₃ receptor (HRH3), remain unexplored. The aim of this study is to analyze the clinical associations of polymorphisms in HDC, HNMT and HRH3 with breast cancer. Two hundred and one unrelated Chinese Han breast cancer patients and 205 ethnicity-matched health controls were recruited for case-control investigation. Genomic DNA from the participants was extracted and 5 single nucleotide polymorphisms (SNPs) in HDC, HNMT and HRH3 were genotyped. We found that polymorphisms of HNMT and HRH3 were irrelevant with breast cancer in the present study. However, the T allele of rs7164386 in HDC significantly decreased the risk of breast cancer (adjusted odds ratios [ORs], 0.387; 95% confidence intervals [CIs], 0.208–0.720; P = 0.003). Furthermore, for HDC haplotypes, the CG haplotype of rs7164386-rs7182203 was more frequent among breast cancer patients (adjusted OR, 1.828; 95% CI, 1.218–2.744; P = 0.004) while the TG haplotype was more frequent among health controls (adjusted OR, 0.351; 95% CI, 0.182–0.678; P = 0.002). These findings indicated that polymorphisms of HDC gene were significantly associated with breast cancer in Chinese Han population and may be novel diagnostic or therapeutic targets for breast cancer. Further studies with larger participants worldwide are still needed for conclusion validation.

Activation of histamine H4 receptors decreases epithelial-to-mesenchymal transition progress by inhibiting transforming growth factor-β1 signalling pathway in non-small cell lung cancer

Previous investigations found that epithelial-to-mesenchymal transition (EMT) was an important character of non-small cell lung cancer (NSCLC) and it was also suggested that histamine H4 receptors may have a role in preventing EMT progress in certain kind of tumours. However, the effect of H4 receptor activation on EMT progress of NSCLC and its potential mechanisms remain unclear. Therefore, we performed both in vitro and in vivo experiments to explore the effects of specific H4 receptor agonist 4-methylhistamine and antagonist JNJ7777120 on EMT progress. We showed the expression of H4 receptors in NSCLC and found that 4-methylhistamine increased the expression of the epithelial marker E-cadherin and decreased the expression of Vimentin, the mesenchymal marker, in both NSCLC cell lines and xenograft NSCLC tumours. Pretreatment with JNJ7777120 or H4 receptor gene silencing decreased while overexpression of H4 receptors facilitated this effect of 4-methylhistamine. Furthermore, we showed that down-regulation of cyclic adenosine monophosphate (cAMP) was the secondary signalling after H4 receptor activation, which in turn resulted in inactivation of transforming growth factor-β1 (TGF-β1) pathway and down-regulation of several important EMT inducing factors such as ZEB1, Snail and Slug. In conclusion, these findings revealed the anti-EMT effect of histamine H4 receptor activation in NSCLC, which provide novel insight into the development mechanism of NSCLC; and H4 receptors may be a new therapeutic target for NSCLC treatment.

Human endogenous retrovirus W family envelope gene activates the small conductance Ca2+-activated K+ channel in human neuroblastoma cells through CREB

Numerous studies have shown that human endogenous retrovirus W family (HERV-W) envelope gene (env) is related to various diseases but the underlying mechanism has remained poorly understood. Our previous study showed that there was abnormal expression of HERV-W env in sera of patients with schizophrenia. In this paper, we reported that overexpression of the HERV-W env elevated the levels of small conductance Ca(2+)-activated K(+) channel protein 3 (SK3) in human neuroblastoma cells. Using a luciferase reporter system and RNA interference method, we found that functional cAMP response element site was required for the expression of SK3 triggered by HERV-W env. In addition, it was also found that the SK3 channel was activated by HERV-W env. Further study indicated that cAMP response element-binding protein (CREB) was required for the activation of the SK3 channel. Thus, a novel signaling mechanism of how HERV-W env influences neuronal activity and contributes to mental illnesses such as schizophrenia was proposed.

[The characteristic unit discharges related to epilepsy recorded synchronously from dual hippocampi induced by tetanization of the right dorsal hippocampus in rats]

AIM

To study the characteristics of unit discharges related to epilepsy of hippocampal neuron in both hemispheres in intact rats.

METHODS

44 pairs of cells were extracellularly recorded with dual glass microelectrodes from bilateral hippocampi before or after administration of repetitive tetani (0.4 - 0.6 mA, 2 s, 60 Hz) to the right dorsal hippocampus. Repeated tetani were used about ten times at 5 or 10 min intervals to ensure full expression of afterdischarges without the tissue being in postictal refractory period.

RESULTS

Primary or secondary unit afterdischarges of hippocampal neurons were evoked by tetani. They were characterized by bilateral asymmetry, moveability and interconversion between two hemispheres, which were observed in temporal lobe epileptic humans. In addition facilitatory or inhibitory, modulating or demodulating effect of tetani on spontaneous unit discharges depended on the basic firing rates or patterns of hippocampal cells before stimulation. Rhythmic cell bursting of the hippocampus was demodulated to tonic firing by Scopolamine (0.05 mg/kg, i.p.). Tetanus-induced inhibition of hippocampal unit discharges was observed after administration of scopolamine.

CONCLUSION

Abnormal electrophysiological activity of bilateral hippocampi neurons evoked by tetanus may be the pathophysiological bases for dual hemispherical sclerosis and atrophy in temporal lobe epilepsy.

Characteristic behavioral seizures and abnormal signal asymmetry of magnetic resonance imaging in an electrogenic rat model of chronic epilepsy

Chronic tetani (60 Hz, 2 s, 0.4~0.6 mA) were administered to the dorsal hippocampus (DHPC) or the medial temporal lobe neocortex (MTNC) of rats, to study the role of the entorhinal cortex (EC)-hippocampal loop in temporal lobe epileptogenesis. This was repeated once a day for 7 or 10 days. Magnification of hyper-intensity was induced by tetanization of the HPC or the MTNC, as detected by contralateral T(2) weighed magnetic resonance imaging (T(2)-WI). The effects were associated with an enlarged volume of the lateral ventricle (LV), which was verified histologically. T(2)-WI hper-intensities, contralateral to the tetanized hemispheres, were observed with high frequency primary wet dog shakes (WEDS) in the DHPC-stimulated rats and with low frequency WEDS in the MTNC-stimulated rats. It seems likely that the same neural mechanisms are shared by chronic tetanization of the right HPC and the righ MTNC, involving the closed EC-HPC loop. Poor correlation between contralateral T(2)-WI hper-intensities and light primary behavioral seizures in the MTNC-stimulated rats might be attributed to a controlled information flow into or out of this loop because of potential EC gating. In addition, asymmetric T(2)-WI hyper-intensities in the LV area reflected a hemispheric dependence, contralateral to the electrogenic focus in our model of rat epilepsy.

Possible role of dentate gyrus in greneration of rat temporal lobe epilepsy induced by electrical stimulation

Possible role of the dentate gyrus (DG) and the hippocampus (HPC) in temporal lobe epileptogensis was investigated in an electrogenic model of rat epilepsy. Chronic tetani (60 Hz, 0.4-0.6 mA. 2 s) were administered once daily for 7 days to the right dorsal hippocampus (DHPC) or the right DG. Animal behavior was observed and depth electro-graphic seizures and T(2)-weighted magnetic resonance images (T(2)-WI) were measured. Results indicated that the frequency of primary wet dog shakes (WEDS) in the DG-stimulated rats was much lower than that in the DHPC-stimulated rats (P<0.05). The mean maximal wave-amplitude in DG electrographs was also much lower than that in HPC electrographs (P<0.05). The oscillations proportion of DHPC electrographs increased after DHPC-tetanization (from 2/9 up to 7/9 rats). T(2)-WI hyperintensity in the lateral ventricle area was detected only in the DHPC-tetanized rats, not in the DG-tetanized rats (P<0.05). These results suggest that the DG acts as a filtering site in the entorhinal cortex-HPC neuronal circuitry and its dysfunction causes damage to the HPC and the generation of temporal lobe epilepsy.

No sex and age influence on the expression pattern and activities of human gastric alcohol and aldehyde dehydrogenases

BACKGROUND

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes responsible for ethanol metabolism in humans. The stomach is involved in the metabolism of alcohol during absorption. Conflicting reports exist with regard to the influence of sex and age on the activity of ADH in the human gastric mucosa. The purpose of the present study was to determine the effects of age and sex on the expression pattern and activities of stomach ADH and ALDH.

METHODS

A total of 115 endoscopic gastric biopsy specimens were investigated from Han Chinese men (n = 70) and women (n = 45) aged 20-79 years with approximately even distribution among 10-year age intervals. The expression patterns of ADH and ALDH were identified by isoelectric focusing, and the activities were assayed spectrophotometrically.

RESULTS

The expression patterns of gastric ADH and ALDH remained unchanged with respect to sex and age. At 33 mM or 500 mM ethanol, pH 7.5, the ADH activities did not differ significantly among the various age groups or between men and women. At 200 microM or 20 mM acetaldehyde, the ALDH activities did not differ significantly in relation to sex and age. No correlations were found between the ADH or ALDH activities at both the high and low substrate concentrations and the ages in men and women.

CONCLUSIONS

The results indicate that there is no significant effect of either sex or age on the expression pattern and activity of ADH and ALDH in the human gastric mucosa. The stomach ADH seems unlikely to account for possible variations in the first-pass metabolism of alcohol with regard to sex and age.

Genetic and environmental influences on alcohol metabolism in humans

This manuscript represents the proceedings of a symposium at the 2000 RSA Meeting in Denver, Colorado. The organizer/chair was Ting-Kai Li. The presentations were: (1) Introduction to the Symposium, by Ting-Kai Li; (2) ALDH2 polymorphism and alcohol metabolism, by Shih-Jiun Yin; (3) ALDH2 promoter polymorphism and alcohol metabolism, by David W. Crabb; (4) Use of BrAC clamping to estimate alcohol elimination rates: Application to studies of the influence of genetic and environmental determinants, by Sean O'Connor; and (5) Effect of food and food composition on alcohol elimination rates as determined by clamping, by Vijay A. Ramchandani.

Alcohol metabolism and cardiovascular response in an alcoholic patient homozygous for the ALDH2*2 variant gene allele

BACKGROUND

Alcohol metabolism is one of the biological determinants that can influence drinking behavior. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes involved in ethanol metabolism. Allelic variation of the ADH and ALDH genes can significantly affect vulnerability for the development of alcoholism. Homozygosity of the variant ALDH2*2 allele previously was believed to fully protect East Asian populations against the development of alcoholism.

METHODS

Eighty Han Chinese alcoholics who met DSM-III-R criteria for alcohol dependence and 144 nonalcohol-dependent subjects were recruited and their data combined with data from 340 alcohol-dependent and 545 nonalcohol-dependent subjects described in an earlier report (Chen et al., 1999) to assess risk for alcoholism by logistic regression analysis. Genotypes of ADH2, ADH3, and ALDH2 were determined by polymerase chain reaction and restriction fragment length polymorphism. The ALDH2 genotype was confirmed by direct nucleotide sequencing. Blood ethanol concentration was determined by headspace gas chromatography and acetaldehyde concentration by high-performance liquid chromatography with fluorescence detection of the derivatized product. Cardiovascular hemodynamic parameters were measured by two-dimensional Doppler echocardiography and sphygmomanometry. Extracranial arterial blood flow was measured by Doppler ultrasonography.

RESULTS

An alcohol-dependent patient was identified to be ALDH2*2/*2, ADH2*2/*2, and ADH3*1/*2. Following challenge with a moderate oral dose of ethanol (0.5 g/kg of body weight), the patient exhibited peak concentrations for ethanol (55.7 mg/dl) and acetaldehyde (125 microM). During 130 min postingestion, the patient generally displayed similar or even less intense cardiovascular hemodynamic alterations when compared to a previously published study of nonalcoholic individuals with ALDH2*2/*2 who had received a lower dose of ethanol (0.2 g/kg). Logistic regression analysis of the combinatorial genotypes of ADH2 and ALDH2 in 420 alcohol-dependent and 689 nonalcohol-dependent subjects indicated that risk for alcoholism was 100-fold lower for the ADH2*2/*2-ALDH2*2/*2 individuals than the ADH2*1/*1-ALDH2*1/*1 individuals.

CONCLUSIONS

The gene status of ALDH2*2/*2 alone can tremendously but not completely (as thought previously) protect against development of alcohol dependence. Individuals carrying the combinatorial genotype of ADH2*2/*2-ALDH2*2/*2 are at the least risk for the disease in East Asians. Physiological tolerance or innate insensitivity to the accumulation of blood acetaldehyde following alcohol ingestion may be crucial for the development of alcoholism in individuals homozygous for ALDH2*2.

Interaction between the functional polymorphisms of the alcohol-metabolism genes in protection against alcoholism

The genes that encode the major enzymes of alcohol metabolism, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), exhibit functional polymorphism. The variant alleles ADH2*2 and ADH3*1, which encode high-activity ADH isoforms, and the ALDH2*2 allele, which encodes the low-activity form of ALDH2, protect against alcoholism in East Asians. To investigate possible interactions among these protective genes, we genotyped 340 alcoholic and 545 control Han Chinese living in Taiwan at the ADH2, ADH3, and ALDH2 loci. After the influence of ALDH2*2 was controlled for, multiple logistic regression analysis indicated that allelic variation at ADH3 exerts no significant effect on the risk of alcoholism. This can be accounted for by linkage disequlibrium between ADH3*1 and ADH2*2 ALDH2*2 homozygosity, regardless of the ADH2 genotypes, was fully protective against alcoholism; no individual showing such homozygosity was found among the alcoholics. Logistic regression analyses of the remaining six combinatorial genotypes of the polymorphic ADH2 and ALDH2 loci indicated that individuals carrying one or two copies of ADH2*2 and a single copy of ALDH2*2 had the lowest risk (ORs 0.04-0.05) for alcoholism, as compared with the ADH2*1/*1 and ALDH2*1/*1 genotype. The disease risk associated with the ADH2*2/*2-ALDH2*1/*1 genotype appeared to be about half of that associated with the ADH2*1/*2-ALDH2*1/*1 genotype. The results suggest that protection afforded by the ADH2*2 allele may be independent of that afforded by ALDH2*2.

Involvement of acetaldehyde for full protection against alcoholism by homozygosity of the variant allele of mitochondrial aldehyde dehydrogenase gene in Asians

There is a functional polymorphism of the mitochondrial aldehyde dehydrogenase (ALDH2) gene with the variant allele (ALDH2*2) encoding a protein subunit that confers low activity to the tetrameric enzyme. Genetic epidemiologic studies have strongly suggested that homozygosity for the allele ALDH2*2 is sufficient in completely inhibiting the development of alcoholism in Asians. To study the pathophysiology of this unique pharmacogenetic effect, we recruited a total of eighteen adult Han Chinese men, matched by age, body-mass index, nutritional state and homozygosity at the alcohol dehydrogenase gene loci from a population base of 273 men. Six individuals were chosen for each of the three ALDH2 allelotypes: homozygous ALDH2*2/*2, heterozygous ALDH2*1/*2, and homozygous ALDH2*1/*1. Following a low dose of ethanol (0.2 g/kg body weight), blood ethanol/acetaldehyde concentrations, cardiac and extracranial/intracranial arterial hemodynamic parameters, as well as self-rated subjective sensations, were measured for 130 min. Homozygous ALDH2*2 individuals were found to be strikingly responsive to the small amount of alcohol, as evidenced by the pronounced cardiovascular hemodynamic effects as well as subjective perception of general discomfort for as long as 2 h following ingestion. This low-dose alcohol hypersensitivity, accompanied by a prolonged and large accumulation of acetaldehyde in blood, provides an explanation for the strong protection against heavy drinking and alcoholism in individuals homozygous for the ALDH2*2 gene allele.

Recommended nomenclature for the vertebrate alcohol dehydrogenase gene family

The alcohol dehydrogenase (ADH) gene family encodes enzymes that metabolize a wide variety of substrates, including ethanol, retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. Studies on 19 vertebrate animals have identified ADH orthologs across several species, and this has now led to questions of how best to name ADH proteins and genes. Seven distinct classes of vertebrate ADH encoded by non-orthologous genes have been defined based upon sequence homology as well as unique catalytic properties or gene expression patterns. Each class of vertebrate ADH shares <70% sequence identity with other classes of ADH in the same species. Classes may be further divided into multiple closely related isoenzymes sharing >80% sequence identity such as the case for class I ADH where humans have three class I ADH genes, horses have two, and mice have only one. Presented here is a nomenclature that uses the widely accepted vertebrate ADH class system as its basis. It follows the guidelines of human and mouse gene nomenclature committees, which recommend coordinating names across species boundaries and eliminating Roman numerals and Greek symbols. We recommend that enzyme subunits be referred to by the symbol "ADH" (alcohol dehydrogenase) followed by an Arabic number denoting the class; i.e. ADH1 for class I ADH. For genes we recommend the italicized root symbol "ADH" for human and "Adh" for mouse, followed by the appropriate Arabic number for the class; i.e. ADH1 or Adh1 for class I ADH genes. For organisms where multiple species-specific isoenzymes exist within a class, we recommend adding a capital letter after the Arabic number; i.e. ADH1A, ADH1B, and ADH1C for human alpha, beta, and gamma class I ADHs, respectively. This nomenclature will accommodate newly discovered members of the vertebrate ADH family, and will facilitate functional and evolutionary studies.

No association between DRD2 locus and alcoholism after controlling the ADH and ALDH genotypes in Chinese Han population

BACKGROUND

Recent studies on the genetics of alcoholism have examined the association between alcoholism and the dopamine D2 receptor locus (DRD2); our study of Chinese Han gave negative results (Lu et al., 1996). The different genotypes at the genes encoding the enzymes involved in alcohol metabolism, class one alcohol dehydrogenase (ADH2 and ADH3) and mitochondrial aldehyde dehydrogenase (ALDH2), have previously been shown to confer different predispositions to the development of alcoholism in Chinese Han males (Thomasson et al., 1991; Chen WJ et al., 1996; Chen CC et al., unpublished data). Therefore, association studies of alcoholism in Chinese Han might be more sensitive if controlled for the genotypes of ADH2,ADH3, and ALDH2, when other loci, such as DRD2, are examined. This study employs such controls to evaluate the evidence for an association between alcoholism and TaqI-A and TaqI-B genotypes and haplotypes at DRD2 in the Chinese Han population.

METHODS

We studied 213 Chinese Han subjects (128 alcoholics and 85 nonalcoholics) with alcohol dependence defined according to DSM-III-R criteria.

RESULTS

Significant linkage disequilibrium was observed between the TaqI-A and TaqI-B sites at the DRD2 locus, as previously seen in smaller samples, but no significant association was observed between these genetic variants at the DRD2 locus and alcoholism in Chinese Han. Several different stratifications by ADH and ALDH2 genotypes were examined; no genotypes or haplotypes at DRD2 differ between alcoholics and nonalcoholics except for a small number of nominally significant p-values which do not constitute significant results given the many tests done, some of which are not independent of one another due to linkage disequilibrium. These tests included considering the high risk (ADH2*1/*1; *1/*2; ADH3*1/*2; *2/*2; and ALDH2*1/*1) and the low risk (ADH2*2/*2; ADH3*1/*1; and ALDH2*1/*2; *2/*2) groups of alcoholics, as well as nonalcoholic controls.

CONCLUSIONS

After stratification by the relevant genotypes of ADH2, ADH3, and ALDH2 no significant association exists between the genetic variants at the DRD2 locus and alcoholism in the Chinese Han population.

Linkage disequilibrium at the ADH2 and ADH3 loci and risk of alcoholism

Two of the three class I alcohol dehydrogenase (ADH) genes (ADH2 and ADH3) encode known functional variants that act on alcohol with different efficiencies. Variants at both these genes have been implicated in alcoholism in some populations because allele frequencies differ between alcoholics and controls. Specifically, controls have higher frequencies of the variants with higher Vmax (ADH2*2 and ADH3*1). In samples both of alcoholics and of controls from three Taiwanese populations (Chinese, Ami, and Atayal) we found significant pairwise disequilibrium for all comparisons of the two functional polymorphisms and a third, presumably neutral, intronic polymorphism in ADH2. The class I ADH genes all lie within 80 kb on chromosome 4; thus, variants are not inherited independently, and haplotypes must be analyzed when evaluating the risk of alcoholism. In the Taiwanese Chinese we found that, only among those chromosomes containing the ADH3*1 variant (high Vmax), the proportions of chromosomes with ADH2*1 (low Vmax) and those with ADH2*2 (high Vmax) are significantly different between alcoholics and controls (P<10-5). The proportions of chromosomes with ADH3*1 and those with ADH3*2 are not significantly different between alcoholics and controls, on a constant ADH2 background (with ADH2*1, P=.83; with ADH2*2, P=.53). Thus, the observed differences in the frequency of the functional polymorphism at ADH3, between alcoholics and controls, can be accounted for by the disequilibrium with ADH2 in this population.

Contribution to first-pass metabolism of ethanol and inhibition by ethanol for retinol oxidation in human alcohol dehydrogenase family--implications for etiology of fetal alcohol syndrome and alcohol-related diseases

The alcohol dehydrogenase (ADH) family is involved in the metabolism of both ethanol and retinoids. To quantitatively assess the potential contributions to first-pass metabolism of ethanol and the ethanol interference with retinoid homeostasis, saturation kinetics for ethanol oxidation as well as inhibition kinetics by ethanol for all-trans-retinol oxidation of human class I alpha alpha, beta1beta1, beta2beta2, gamma1gamma1, class II pi pi, class III chi chi, and class IV mu mu were evaluated and compared. Class I and class II ADHs exhibited substrate inhibition with inhibition constants ranging over 250-720 mM (except gamma1gamma1) ethanol. Class IV ADH displayed no appreciable inhibition up to 1 M ethanol. Activity of the class III enzyme (190 nM subunit) was undetectable at 250 mM ethanol. The kinetic simulations indicate that the hepatic pi pi and the gastric mu mu can most effectively contribute to first-pass metabolism of alcohol. The Michaelis constant (Km), turnover number (k(cat)), and catalytic efficiency (k(cat)/Km) for retinol oxidation relative to that for ethanol oxidation in class I, class II, and class IV ADHs ranged over 0.00022-1.3, 0.071-0.48, and 0.24-650, respectively. Ethanol was a competitive inhibitor against retinol for class I, II, and IV ADHs with apparent inhibition constants ranging over 0.037-11 mM, indicating that retinoic acid synthesis through the ADH pathways can be tremendously blocked during social/heavy drinking. These findings support the notion that first-pass metabolism of alcohol may occur mainly in the liver through class II pi pi and that cellular retinoid signaling may be perturbed by ethanol via ADH pathways.

Human hepatic alcohol and aldehyde dehydrogenases: genetic polymorphism and activities

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the major enzymes responsible for the metabolism of ethanol in the body. Both exhibit genetic polymorphism in racial populations. To determine hepatic ethanol metabolizing activities in relation to genetic polymorphism, a total of 23 surgical specimens were investigated. The expression patterns of ADH and ALDH isoenzymes were identified by means of agarose isoelectric focusing, and the activities were assayed spectrophotometrically. At 33 mM ethanol, pH 7.5, the activities in the liver with the homozygous phenotype ADH2 1-1 and ADH2 2-2 and the heterozygous phenotype ADH2 1-2 were determined to be 2.9 +/- 0.7, 16.0 +/- 2.5, and 13.6 +/- 1.0 U/g tissue, respectively. The activities of the ALDH2-active and ALDH2-inactive phenotypes at 200 microM acetaldehyde were determined to be 1.06 +/- 0.13 and 0.71 +/- 0.07 U/g tissue, respectively. These findings indicate that human hepatic ethanol-metabolizing activities differ significantly with respect to polymorphism at both the ADH2 and ALDH2 loci. The results suggest that this genetically determined differential hepatic activity may influence drinking behavior and the development of alcoholism among Orientals.

Human stomach alcohol and aldehyde dehydrogenases: comparison of expression pattern and activities in alimentary tract

BACKGROUND & AIMS

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the major enzymes responsible for ethanol metabolism in humans. The human stomach has been documented to be involved in the metabolism of first-passed alcohol. The aim of this study was to determine ethanol-metabolizing activities in the stomach with regard to sex, age, enzyme pattern, and polymorphism.

METHODS

A total of 209 surgical gastric mucosal specimens were investigated. The expression patterns of ADH and ALDH were identified by isoelectric focusing, and the activities were assayed spectrophotometrically.

RESULTS

At 33 or 500 mmol/L ethanol, pH 7.5, the activities in the ADH3 1-1 phenotypic and mu-ADH-expressing mucosal specimens were significantly greater than that in the ADH3 1-2 phenotypic and mu-ADH absent mucosal specimens, respectively. The activities of the ALDH2-inactive phenotypes were significantly lower than that of the ALDH2-active phenotypes at 200 micromol/L acetaldehyde. The gastric ADH and ALDH activities were not significantly different between men and women with respect to age and genetic polymorphism.

CONCLUSIONS

The stomach may contribute only a small portion of the alcohol metabolism observed in humans, and the liver may be the major site for first-pass metabolism. Differential expression patterns of ADH and ALDH in the alimentary tract suggest that different vulnerabilities to ethanol-induced mucosal injury may exist.

Expression and activities of class IV alcohol dehydrogenase and class III aldehyde dehydrogenase in human mouth

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes responsible for the oxidation of ingested ethanol in humans. To study these two enzymes in surgical specimens of attached gingiva and tongue, we have examined the isozyme patterns by agarose isoelectric focusing and determined the enzyme activities. Class IV mu-ADH, class III chi-ADH, and class III ALDH3 were detected in the oral mucosa tissues. Gingival mu-ADH exhibited a pH optimum for ethanol oxidation at 10 and the K(m) value for ethanol (pH 7.5) was estimated to be 27 mM. At pH 7.5 and 30 degrees C, the ADH activities in the gingiva and tongue samples were determined to be 90.0 +/- 5.8 (mean +/- SE; n = 24) and 50.6 +/- 5.1 (n = 3) nmol/min/g tissue (at 33 mM ethanol), and 138 +/- 11 and 55.1 +/- 4.7 nmol/min/g tissue (at 500 mM ethanol), respectively. The ALDH activities at 20 mM acetaldehyde were determined to be 169 +/- 19 and 50.3 +/- 8.1 nmol/min/g tissue for the gingiva and tongue, respectively. We conclude that ethanol can be significantly metabolized in human attached gingiva and lingual mucosa by mu-ADH. The result also suggests that, due to lacking activity of low K(m) ALDH2 and ALDH1, cytotoxic metabolite acetaldehyde may be involved in the etiology of alcohol-related oral injury.

Cytochrome P4502E1 genotypes, alcoholism, and alcoholic cirrhosis in Han Chinese and Atayal Natives of Taiwan

Genetic factors may play a role in the development of alcoholic liver disease (ALD). Cytochrome P4502E1 (CYP2E1) catalyzes the oxidation of ethanol, producing acetaldehyde and free radicals capable of reacting with and peroxidizing cell membranes. Polymorphisms have been identified in the 5-flanking region of the CYP2E1 gene that may alter the transcriptional activity. In our laboratory, no difference in c1 and c2 allele frequencies was observed between alcoholic patients with or without liver disease in Caucasian men, but there is reported data to the contrary for other populations. To determine if there is a differential susceptibility to ALD between ethnic groups that differ in the frequency of the c2 allele, we studied 30 Han Chinese with severe alcoholic liver disease. Allele frequencies of alcoholics with cirrhosis were compared with 46 alcoholic and 100 nonalcoholic Han individuals without liver disease. To identify the type A (homozygous for c1), type B (heterozygous for c1 and c2) and type C (homozygous for c2) genotypes, DNA encompassing the polymorphisms was amplified by polymerase chain reaction, slot-blotted, and probed with allele-specific oligonucleotides, No significant differences in c2 allele frequencies were found: 0.23 for alcoholics with severe liver disease, 0.20 for alcoholics without liver disease, and 0.26 for the normal population. There also was no difference in c2 allele frequencies between alcoholic and nonalcoholic Atayal natives from Taiwan. Therefore, our results suggest that the allelic variations at the CYP2E1 gene locus also do not significantly affect the development of alcoholism or ALD in Han Chinese and Atayal natives of Taiwan.

Distribution and evolution of CTG repeats at the myotonin protein kinase gene in human populations

We have analyzed the CTG repeat length and the neighboring Alu insertion/deletion (+/-) polymorphism in DNA samples from 16 ethnically and geographically diverse human populations to understand the evolutionary dynamics of the myotonic dystrophy-associated CTG repeat. Our results show that the CTG repeat length is variable in human populations. Although the (CTG)5 repeat is the most common allele in the majority of populations, this allele is absent among Costa Ricans and New Guinea highlanders. We have detected a (CTG)4 repeat allele, the smallest CTG known allele, in an American Samoan individual. (CTG) > or = 19 alleles are the most frequent in Europeans followed by the populations of Asian origin and are absent or rare in Africans. To understand the evolution of CTG repeats, we have used haplotype data from the CTG repeat and Alu(+/-) locus. Our results are consistent with previous studies, which show that among individuals of Caucasian and Japanese origin, the association of the Alu(+) allele with CTG repeats of 5 and > or = 19 is complete, whereas the Alu(-) allele is associated with (CTG)11-16 repeats. However, these associations are not exclusive in non-Caucasian populations. Most significantly, we have detected the (CTG)5 repeat allele on an Alu(-) background in several populations including Native Africans. As no (CTG)5 repeat allele on an Alu(-) background was observed thus far, it was proposed that the Alu(-) allele arose on a (CTG)11-13 background. Our data now suggest that the most parsimonious evolutionary model is (1) (CTG)5-Alu(+) is the ancestral haplotype; (2) (CTG)5-Alu(-) arose from a (CTG)5-Alu(+) chromosome later in evolution; and (3) expansion of CTG alleles occurred from (CTG)5 alleles on both Alu(+) and Alu(-) backgrounds.

Helicobacter Pylori Infection in Patients with Gastric Adenocarcinoma

We examined the biologic tumor behavior in Helicobacter pylori-seropositive patients with gastric adenocarcinoma. A total of 214 consecutive patients with pathologically confirmed adenocarcinoma of the stomach who underwent gastric resection were studied. The stored serum samples were tested for serum antibody to H. pylori by using a highly sensitive and specific IgG enzyme-linked immunosorbent assay. The difference in H. pylori-seropositive and seronegative patients with gastric adenocarcinoma was evaluated in terms of various clinicopathologic parameters. A multivariate logistic regression analysis was used to adjust for potential confounding variables. Antibodies to H. pylori were detected in 65.9% of patients with gastric adenocarcinoma. H. pylori-seropositive patients were younger than seronegative patients and had infiltrative tumor according to Ming's criteria. When adjusted for age, infiltrative tumor come out stronger. These findings suggest that H. pylori infection may be related to infiltrative type gastric adenocarcinoma; further study is necessary.

Ethanol and acetaldehyde metabolism in chinese with different aldehyde dehydrogenase-2 genotypes

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the major enzymes responsible for ethanol metabolism in humans. Both enzymes exhibit genetic polymorphisms among racial populations. About half of the Chinese population lack mitochondrial ALDH2 activity and such a deficiency has been believed to be a negative risk factor for the development of alcoholism. To assess ethanol and acetaldehyde metabolism in Chinese with different ALDH2 genotypes, we genotyped 273 male adults at the ADH2, ADH3, and ALDH2 loci by using polymerase chain reaction-directed mutagenesis and restriction fragment length polymorphisms. Of the 143 individuals homozygous for both the ADH2*2 and the ADH3*1 alleles, 80, 55, and 8 were identified as ALDH2*1/*1, ALDH2*1/*2, and ALDH2*/*2, respectively. Five each from the above three ALDH2 genotypic subjects underwent alcohol elimination testing. Blood ethanol and acetaldehyde levels were determined at various times up to 130 min after intaking a low dose of ethanol (0.2 g/kg body weight) by using head-space gas chromatography and high-performance liquid chromatography with fluorescence detection, respectively. The mutant homozygotes of ALDH2*2/*2 and the heterozygotes exhibited significantly higher peak acetaldehyde concentrations and also greater areas under the blood concentrations-time curve (AUC) than did the normal homozygotes of ALDH2*1/*1, with the mutant homozygotes both being the largest. The mutant homozygotes displayed significantly higher peak ethanol levels and AUC compared to the normal homozygotes. Of the 17 subjective feeling items tested, palpitation, facial warming, effects of alcohol, and dizziness were found to be most pronounced among the mutant homozygotes.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic polymorphism and activities of human colon alcohol and aldehyde dehydrogenases: no gender and age differences

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzyme patterns from 69 (men, 47; women, 22) surgical colon mucosal specimens were identified by agarose isoelectric focusing. gamma-ADH was found to be the predominant form in the mucosa, whereas only beta-ADH was detectable in the muscle layer. ALDH1, ALDH2, and ALDH3 were detectable in the mucosa, with cytosolic ALDH1 being the major form. At pH 7.5, the ADH activities in the colon mucosae with the homozygous phenotype (exhibiting gamma 1 gamma 1) and the heterozygous phenotype (exhibiting gamma 1 gamma 1, gamma 1, gamma 2, gamma 2, gamma 2) were determined to be 183 +/- 13 and 156 +/- 30 nmol/min/g tissue, respectively. The ALDH activities in the ALDH2-active and ALDH2-inactive phenotypes were determined to be 40.2 +/- 2.3 and 34.6 +/- 2.0 nmol/min/g tissue, respectively. The lack of significant difference in the ALDH activities between these two phenotypic groups can be attributed to the very low expression of the mitochondrial ALDH2 in the colon mucosa. No significant differences in the ADH or the ALDH activities were found between the men and women studied and between the three age groups (20-40, 49-70, and 72-83 years). The ascending, transverse, descending, and sigmoid colons exhibited similar ADH and ALDH activities. The isoenzyme patterns of ADH and ALDH remained unaltered in colon carcinomas, except that a significant reduction of the enzyme activities was found in the cancer tissue as compared with the adjacent normal portions. it is concluded that human colon mucosa exhibits significant amounts of ethanol- and acetaldehyde-oxidizing activities.

Genotyping of alcohol dehydrogenase at the ADH2 and ADH3 loci by using a polymerase chain reaction and restriction-fragment-length polymorphism in Chinese alcoholic cirrhotics and non-alcoholics

We investigated the genotype of ADH2 and ADH3 in Chinese alcoholic cirrhotics and non-alcoholics by using a polymerase chain reaction and restriction-fragment-length polymorphism. This method is non-radioactive, easy to implement with good reproducibility. In the Chinese population, the frequencies of the ADH2*1 and ADH3*2 alleles were significantly higher in the alcoholic cirrhotic patients (53%; 23%) than in the viral hepatitis cirrhotics (32%; 8%) and the gastric and/or duodenal ulcer control patients (25%; 6%). On the other hand, the gastric and/or duodenal ulcer control patients and the viral hepatitis cirrhotic patients showed similar allele frequencies for the polymorphic ADH2 and ADH3 genes. These findings suggest that the alleles ADH2*2 and ADH3*1, coding for the high-Vmax beta 2-ADH and gamma 1-ADH, respectively, may play a protective role against alcoholism in Chinese patients.

Low frequency of the ADH2*2 allele among Atayal natives of Taiwan with alcohol use disorders

Genetic variation at two polymorphic alcohol dehydrogenase loci, ADH2 and ADH3, and at the polymorphic mitochondrial aldehyde dehydrogenase locus, ALDH2, may influence the risk of developing alcoholism by modulating the rate of elimination of ethanol and the rate of formation and elimination of acetaldehyde. Populations differ in allele frequencies at these loci. We determined the genotypes at all three of these loci in Atayal natives of Taiwan. The frequencies of ADH2*2, ADH3*1, and ALDH2*1 alleles (0.91, 0.99, and 0.95, respectively) were significantly higher among the Atayal than among a predominantly Han Chinese population from Taiwan. Among the Atayal, the group with alcohol use disorders (alcohol dependence and alcohol abuse) had a significantly lower frequency of the ADH2*2 allele (0.82) than those without alcohol use disorders (0.91). The ADH2*2 allele encodes the beta 2 subunit; isozymes containing beta 2 subunits oxidize alcohol faster in vitro than the beta 1 beta 1 isozyme encoded by ADH2*1. Thus, the simplest explanation for these data is that individuals with a beta 2 isozymes have a higher rate of ethanol oxidation, which is a deterrent to alcohol abuse and dependence in some individuals. The Atayal with alcohol use disorders also had a lower frequency of ALDH2*2 than the controls; this allele is known to be responsible for the alcohol-flush reaction among Asians, and thereby deters drinking.

Polymorphism of alcohol and aldehyde dehydrogenase genes and alcoholic cirrhosis in Chinese patients

Liver alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), the principal enzymes responsible for the oxidation of ethanol, are polymorphic at the ADH2, ADH3 and ALDH2 loci in human beings. Our previous studies have shown that, compared with nonalcoholic individuals, Chinese alcoholic patients without liver disease had significantly lower frequencies of the ADH2*2 and ADH3*1 alleles, which encode high maximum velocity beta 2- and gamma 1-ADH subunits, respectively, as well as a lower frequency of the ALDH2*2 allele, which encodes an enzymatically inactive subunit. The data strongly suggest that genetic variation in both ADH and ALDH may influence drinking behavior and the risk of alcoholism developing through acetaldehyde formation. To further investigate the possible role of acetaldehyde in the pathogenesis of alcoholic liver disease, we determined the ADH and ALDH genotype frequencies in patients with alcohol-related cirrhosis (n = 27), viral hepatitis-related cirrhosis (n = 29) and gastric and duodenal ulcer without relevance to alcohol (n = 30). We developed a new restriction fragment length polymorphism method to genotype the mutant and normal ALDH2 alleles by using polymerase chain reaction-directed mutagenesis, which proved to be simpler and faster than the conventional detection methods that use hybridization with allele-specific oligonucleotide probes. We found that the frequencies of the alleles ADH2*2 (57%), ADH3*1 (78%) and ALDH2*2 (9%) in the alcoholic cirrhotic patients were significantly lower than those in the healthy controls and in the patients with cirrhosis from viral hepatitis and with gastric and duodenal ulcer.(ABSTRACT TRUNCATED AT 250 WORDS)

Dominance of the mutant ALDH2(2) allele in the expression of human stomach aldehyde dehydrogenase-2 activity

About half of Chinese individuals lack mitochondrial aldehyde dehydrogenase-2 (ALDH2) activity, which is responsible for the oxidation of acetaldehyde produced during ethanol metabolism. The ALDH2 deficiency in Chinese has been implicated in alcohol flush reaction and reported to be a negative risk factor for development of alcohol dependence. To assess the effects of inactive ALDH2 subunits, encoded by the mutant ALDH2(2) allele, on the catalytic activity of tetrameric enzyme molecules, we have phenotyped ALDH2 from 30 gastroendoscopic biopsies by using agarose isoelectric focusing and determined the genotypes from leukocytes of the same individuals by using polymerase-chain-reaction amplification and hybridization with allele-specific oligonucleotide probes. Sixteen subjects were homozygous for the ALDH2(1) allele, one was homozygous for ALDH2(2), and thirteen were the heterozygous genotype. None of the subjects with the mutant homozygotic and the heterozygotic genotypes exhibited the ALDH2 activity band or intermediate bands between ALDH2 and ALDH1 on isoelectric focusing gels. Our results support the notion that the mutant allele is dominant and that the heterotetrameric ALDH2 molecules containing the mutant subunits are enzymatically inactive or far less active.

Alcohol and aldehyde dehydrogenases in human esophagus: comparison with the stomach enzyme activities

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzymes from surgical esophageal and gastric mucosa were compared by agarose isoelectric focusing. Two prominent ADH forms, designated mu 1 (equivalent to the recently reported mu-form) and mu 2, were expressed in all the 15 esophagus specimens studied, whereas only four of seven examined gastric specimens exhibited a weak to moderately strong mu 1-ADH activity band on the isoelectric focusing gels. pI values of the esophageal mu 1-ADH and mu 2-ADH, and the liver pi-ADH were determined to be 8.61, 8.13, and 8.90, respectively. mu-ADHs exhibited high Km for ethanol (12 mM) and low sensitivity to 4-methylpyrazole inhibition. ALDH3 (BB form) and ALDH1 were the major high- and low-Km aldehyde dehydrogenase in the esophagus, respectively. The ADH and ALDH activities were determined at pH 7.5 to be 751 +/- 78 and 29.9 +/- 3.0 nmol/min/g tissue, respectively (measured at 500 mM ethanol or at 200 microM acetaldehyde; mean +/- SEM; N = 15). The esophageal ADH activity was approximately 4-fold and the ALDH activity 20% that of the stomach enzyme. Because the presence of high activity and high Km mu-ADHs as well as low-activity ALDH1 were found in human esophageal mucosa, it is suggested that there may exist an accumulation of intracellular acetaldehyde during alcohol ingestion. This reactive and toxic metabolite may be involved in the pathogenesis of alcohol-induced esophageal disorders.