ADH Genotypes and Alcohol Use and Dependence in Europeans

We have tested for effects of alcohol dehydrogenase ( ADH ) genotypes on self-reported alcohol consumption and symptoms of alcohol dependence, recorded on three occasions up to 15 years apart, in 377 male and female subjects of European descent. ADH2 genotype had significant effects on both consumption and dependence in the men, but not in the women. The effects of ADH3 genotype were considerably less than those of ADH2 , but significant results could be demonstrated when the combined genotypes were considered. The direction of the effects on alcohol consumption and dependence risk were consistent with reports on Asian subjects, and with the in vitro properties of ADH isoenzymes. As with previous studies on the relationship between ADH type and alcohol use, population stratification cannot be excluded as a contributing factor in these results.     

A Korean female patient with thiamine-responsive pyruvate dehydrogenase complex deficiency due to a novel point mutation (Y161C)in the PDHA1 gene

Pyruvate dehydrogenase complex (PDHC) deficiency is mostly due to mutations in the X-linked E1alpha subunit gene (PDHA1). Some of the patients with PDHC deficiency showed clinical improvements with thiamine treatment. We report the results of biochemical and molecular analysis in a female patient with lactic acidemia. The PDHC activity was assayed at different concentrations of thiamine pyrophosphate (TPP). The PDHC activity showed null activity at low TPP concentration (1 x 10(-3) mM), but significantly increased at a high TPP concentration (1 mM). Sequencing analysis of PDHA1 gene of the patient revealed a substitution of cysteine for tyrosine at position 161 (Y161C). Thiamine treatment resulted in reduction of the patient's serum lactate concentration and dramatic clinical improvement. Biochemical, molecular, and clinical data suggest that this patient has a thiamine-responsive PDHC deficiency due to a novel mutation, Y161C. Therefore, to detect the thiamine responsiveness it is necessary to measure activities of PDHC not only at high but also at low concentration of TPP.     

COX-2抑制剂对胃癌细胞生长及其15-PGDH表达的影响

背景:15-羟基前列腺素脱氢酶(15-PGDH)是前列腺素生物降解的关键酶,环氧合酶-2(COX-2)是前列腺素合成的重要限速酶,目前两者间的关系尚不明确。目的:观察非选择性和选择性COX-2抑制剂对胃癌细胞生长、凋亡以及15-PGDH、COX-2表达的影响,探讨胃癌中15-PGDH与COX-2的关系。方法:以不同浓度吲哚美辛和塞来昔布干预人胃癌细胞株SGC-7901,MTF法检测细胞生长抑制情况,RT-PCR检测凋亡相关基因survivin、bax、bcl-xL表达,RT-PCR和蛋白质印迹法检测15-PGDH、COX-2表达。结果:吲哚美辛和塞来昔布均能抑制SGC-7901细胞生长,抑制作用呈时间/浓度依赖性。药物干预后,SGC-7901细胞的15-PGDH mRNA和蛋白表达显著升高,COX-2 mRNA和蛋白表达显著降低;同时抗凋亡基因survivin、bcl-xL mRNA表达降低,促凋亡基因bax mRNA表达升高。结论:非选择性和选择性COX-2抑制剂均可诱导胃癌细胞15-PGDH表达,抑制COX-2表达,提示胃癌中15-PGDH低表达与COX-2过表达相关。COX-2抑制剂可能通过促进15-PGDH表达、下调抗凋亡基因表达、上调促凋亡基因表达而抑制胃癌细胞生长。     

Effects of actinomycin D on fetal growth in rats

Objective : The goal of this study was to determine the effects of actinomycin D on fetal growth and prostaglandin dehydrogenase activity and to determine whether these effects could be obtained by administering extracts of fetal calf serum (SS-094). Methods : Actinomycin D (7 &#119 g/100 g body weight) was injected intraperitoneally on days 11 and 12 of pregnancy to induce growth restriction in rats. In another group, SS-094 was given (0.1 ml/100 g body weight) on days 12, 15, 17 and 19 of pregnancy, following the administration of actinomycin D. Placental prostaglandin dehydrogenase (PGDH) activity was measured on days 15 and 21 of pregnancy. Statistical analysis was performed by ANOVA and Dunnet's test. Results : In the group injected with actinomycin D, fetal weight was significantly restricted (on day 15; p < 0.05; on day 21; p < 0.01), compared to the controls, and this restriction was successfully reversed by SS-094. PGDH activity in the placenta was significantly ( p < 0.01) decreased in growth-restricted rats and remained low even after fetal weight recovered. Conclusions : Growth restriction in pregnant rats was successfully induced by actinomycin D, and SS-094 reversed this restriction. It does not seem that prostaglandin metabolism in the placenta is responsible for growth restriction.     

Contribution of NADH Increases to Ethanol's Inhibition of Retinol Oxidation by Human ADH Isoforms

Background:  A decrease in retinoic acid levels due to alcohol consumption has been proposed as a contributor to such conditions as fetal alcohol spectrum diseases and ethanol-induced cancers. One molecular mechanism, competitive inhibition by ethanol of the catalytic activity of human alcohol dehydrogenase (EC 1.1.1.1) (ADH) on all-trans-retinol oxidation has been shown for the ADH7 isoform. Ethanol metabolism also causes an increase in the free reduced nicotinamide adenine dinucleotide (NADH) in cells, which might reasonably be expected to decrease the retinol oxidation rate by product inhibition of ADH isoforms.
Methods:  To understand the relative importance of these two mechanisms by which ethanol decreases the retinol oxidation in vivo we need to assess them quantitatively. We have built a model system of 4 reactions: (1) ADH oxidation of ethanol and NAD⁺, (2) ADH oxidation of retinol and NAD⁺, (3) oxidation of ethanol by a generalized Ethanol_oxidase that uses NAD⁺, (4) NADH_oxidase which carries out NADH turnover.
Results:  Using the metabolic modeling package S crum P y , we have shown that the ethanol-induced increase in NADH contributes from 0% to 90% of the inhibition by ethanol, depending on (ethanol) and ADH isoform. Furthermore, while the majority of flux control of retinaldehyde production is exerted by ADH, Ethanol_oxidase and the NADH_oxidase contribute as well.
Conclusions:  Our results show that the ethanol-induced increase in NADH makes a contribution of comparable importance to the ethanol competitive inhibition throughout the range of conditions likely to occur in vivo, and must be considered in the assessment of the in vivo mechanism of ethanol interference with fetal development and other diseases.     

一种丝状真菌活细胞生物量测定方法的研究

研究了一种基于测定脱氢酶活（DHA）的生化方法，用以测定真菌活细胞生物量和评价菌丝活力。四唑盐（TTC）在活细胞体内经脱氢酶还原生成红色甲臌（TF）。以氢化可的松生产菌株Abasidia coerulea为模式菌，通过优化染色时间（60min）、温度（45℃）、pH值8．0，提高了该方法的灵敏度。活细胞湿重与吸光度线形相关（r2=0．98），验证了该方法的有效性。另外，使用优化后的方法，所测脱氢酶比活力可以用来准确评价菌丝体活力。     

Lactic dehydrogenase isoenzyme in cerebrospinal fluid of children with febrile convulsions

Aim: To study the lactic dehydrogenase isoenzyme values in children with simple and complex febrile convulsions. Methods: Cerebrospinal fluid samples were collected from 115 children, 57 with simple febrile convulsions, 27 with complex febrile convulsions and 31 with no neurological or intracranial pathology (controls). Lactic dehydrogenase activity and isoenzyme levels were measured on a Hitachi analyser. Results: Mean total lactic dehydrogenase activity was similar in the three groups. In the control group, lactic dehydrogenase-1 was the main fraction, followed by lactic dehydrogenase-2 and lactic dehydrogenase-3; only small percentages of lactic dehydrogenase-4 and lactic dehydrogenase-5 were detected. In the febrile convulsion group, the lactic dehydrogenase-1 fraction percentage was lower and lactic dehydrogenase-2, lactic dehydrogenase-3 percentages were higher than those in the control group; and the differences were statistically significant between the control and study groups (p 3 0.01). Values of lactic dehydrogenase-4 and lactic dehydrogenase-5 were similar in all three groups.

Conclusion: This is the first report on the lactic dehydrogenase isoenzyme pattern in the cerebrospinal fluid of patients with simple and complex febrile convulsions. The important finding that focal and general febrile convulsions are not associated with cell damage and changes in aerobic and anaerobic metabolism as lactic dehydrogenase remained unchanged. Analysis of cerebrospinal fluid lactic dehydrogenase isoenzyme levels can assist clinicians in differentiating febrile convulsions from clinical situations that might mimic them.     

Anaerobic enzyme adaptations to sprint training in rats

Summary The adaptability of several regulatory glycolytic enzymes to chronic sprint exercise has been investigated. Ten animals were subjected to an 11-week running program consisting of 30-sec sprints interposed with 30-sec rest periods and were running up to 18 sprints a day at 80.5 m/min during the eleventh week. Ten animals served as sedentary controls. Phosphorylase (PHOS), phosphofructokinase (PFK), and pyruvate kinase (PK) activities were estimated in samples from the red and white portions of the gastrocnemius muscle (RG and WG), the red area of the vastus lateralis muscle (RV), and the soleus muscle (S). In control animals the activities of PHOS, PFK, and PK were highest in the WG, followed in order by the RV, RG, and S. Significantly more fast-twitch fibers were classified as high-oxidative in the WG of the trained animals. Only the S showed a consistent increase in glycolytic enzyme capacity with training. The findings indicate that most skeletal muscles possess sufficient anaerobic capacity to meet the demands of heavy, short-term intermittent work without adaptation to a higher level.