Polymorphisms of the uridine-diphosphoglucuronosyltransferase 1A1 gene and coronary artery disease

Bilirubin, an antioxidant in the blood, plays a role in protection from atherosclerosis. The level of bilirubin is highly correlated to the incidence of coronary artery disease (CAD). Unconjugated bilirubin is conjugated with glucuronic acid through the reaction of uridine 5′-diphosphate-glucuronosyl transferase 1A1 (UGT1A1). The interactions of CAD and the variations in the coding regions of the UGT1A1 gene have never been evaluated. The purpose of this study was to analyze the influence of the UGT1A1 variant on the incidence of CAD. There were 135 participants in this study: 61 in the experimental group, who had CAD, and 74 in the control group, who did not have CAD. The blood samples from all 135 participants were collected and assayed to clarify the relationship between bilirubin and CAD. The assay of the polymerase chain reaction and the sequence of the UGT1A1 gene were examined to find the gene’s polymorphisms. The bilirubin levels for the participants in the control group were significantly higher than for the patients in the CAD group. Although the concentration of bilirubin in the UGT1A1 variant was higher than the wild type for the patients in the CAD group, there was no significant difference in the polymorphism of UGT1A1 between the patients in the CAD group and the participants in the control group.     

虫食与熏蒸对马尾松挥发性化学物质的影响

通过接虫咬食伤害与茉莉酸甲酯和萜烯混合熏蒸处理,以正常盆栽马尾松为对照,用TCT-GC-MS分析各处理的正常枝、损伤枝、姊妹枝(正常或损伤对枝)、系统上枝(正常或损伤上枝)和系统下枝(正常或损伤下枝)中挥发物的成分及相对含量变化,以探讨马尾松对不同伤害的应急反应.结果显示,虫害和熏蒸处理后,水芹烯的相对含量在损伤枝、姊妹枝、系统上枝和系统下枝中均明显高于对照;β-蒎烯相对含量在损伤枝和姊妹枝中升高,而系统枝条中下降;α-蒎烯相对含量在所测4个部位中除熏蒸后系统下枝升高外其余全部降低;其他挥发性化学物质相对含量的变化没有明显的规律性.结果表明,茉莉酸甲酯和萜烯混合熏蒸能够代替虫害等外界伤害的刺激,使马尾松启动相似的信号防御系统,达到防御外界伤害的作用;茉莉酸甲酯和萜烯可作为马尾松响应伤害的报警信号分子.     

Synthesis of some novel imidazole-based dicationic carbazolophanes as potential antibacterials

Synthesis of fluorescent imidazole-based dicationic carbazolophanes incorporating various spacer units is described. Interestingly, the cyclophanes 2a and 5a incorporating a pyridine moiety exhibited superior antibacterial activity against most of the pathogenic bacteria in the tested concentrations as compared to the other cyclophanes as well as the test control, benzalkonium chloride (BAC), cetylpyridinium chloride (CPC) and tetracycline.     

Microbial population changes during bioremediation of nitroaromatic- and nitramine-contaminated lagoon

Nitration reactions of aromatic compounds are commonly involved in military industrial processes. Military industries treated their process effluents using lagoon systems for many years. In this study, the sediment of a lagoon was investigated from a bioremediation objective. The physico-chemical characterization of the sediments showed the organic nature of the sediment (25.4% carbon with a C:N=3) highly concentrated in RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) as well as two herbicides Dinoterb (2-tert-butyl-4,6-dinitrophenol) and Dinoseb (2-sec-butyl-4,6-dinitrophenol). Analysis of the 16S rRNA gene clone library revealed the presence of three dominant families, Geobacteriacea, Clostridiaceae and Pseudomonaceae. A bioremediation assay was carried out in anaerobic conditions in order to degrade organic compounds. In these conditions, 100% of Dinoterb and Dinoseb were degraded after 75 days of culture, while RDX and HMX were not consumed. The 16S rRNA gene clone library analysis of this incubation showed a drastic reduction of the final biodiversity composed by clones related to Enterobacteriaceae (especially Leclercia adecarboxylata) and Pseudomonaceae family. It was then suggested that Enterobacteriaceae and Pseudomonaceae were potentially involved in biodegradation of these two herbicides. To confirm this hypothesis, cultures were carried out with isolated species of Pseudomonas putida, Pseudomonas citronellolis and L. adecarboxylata in the presence of Dinoterb. The data confirmed that in the presence of glucose, these microorganisms are able to consume Dinoterb.     

植物与手性化合物的对映体选择性相互作用

植物与手性化合物存在着非常密切的联系.一方面,植物分泌、合成的一些手性化合物,如糖甙、酶、萜类化合物、有机酸及植物激素等,在植物的生理生化过程中起着重要的作用;另一方面,人工合成的手性化合物尤其是农药等环境污染物与植物具有对映体选择性相互作用,它们或是选择性地抑制植物的生长和生理过程,或是被植物选择性地吸收和代谢.因此,在开发、生产和使用手性化合物时需要考虑植物与对映体之间的选择性因素;同时,合理利用植物对手性污染物进行环境修复也具有重要意义.本文对植物与手性化合物相互作用中的对映体选择性进行了综述,并对手性污染物的植物修复进行了展望.     

Bioactive food components and cancer risk reduction

Research over the last three decades has provided convincing evidence to support the premise that diets rich in fruits and vegetables may be protective against the risk of different types of cancers. Initial evidence for protective effect of fruits and vegetables against cancer risk came from population-based case-control studies, which prompted intense research aimed at (a) identification of bioactive component(s) responsible for the anticancer effects of fruits and vegetables, (b) elucidation of the mechanisms by which bioactive food components may prevent cancer, and (c) determination of their efficacy for prevention of cancer in animal models. The bioactive components responsible for cancer chemopreventive effects of various edible plants have now been identified. For instance, anticancer effect of Allium vegetables including garlic is attributed to organosulfur compounds (e.g., diallyl trisulfide). Interestingly, unlike cancer chemotherapy drugs, many bioactive food components selectively target cancer cells. Molecular basis for selectivity of anticancer bioactive food components towards cancer cells remains elusive, but these agents appear promiscuous and target multiple signal transduction pathways to inhibit cancer cell growth in vitro and in vivo. Despite convincing observational and experimental evidence, however, limited effort has been directed towards clinical investigations to determine efficacy of bioactive food components for prevention of human cancers. This article reviews current knowledge on cancer chemopreventive effects of a few highly promising dietary constituents, including garlic-derived organosulfides, berry compounds, and cruciferous vegetable-derived isothiocyanates, and serves to illustrate complexity of the signal transduction mechanisms in cancer chemoprevention by these promising bioactive food components.     

Increased heart rate variability in mice overexpressing the Cu/Zn superoxide dismutase

Cu/Zn superoxide dismutase (SOD1) is implicated in various pathological conditions including Down's syndrome, neurodegenerative diseases, and afflictions of the autonomic nervous system (ANS). To assess the SOD1 contribution to ANS dysfunction, especially its influence on cardiac regulation, we studied the heart rate variability (HRV) and cardiac arrhythmias in conscious 12-month-old male and female transgenic mice for the human SOD1 gene (TghSOD1). TghSOD1 mice presented heart rate reduction as compared with control FVB/N individuals. All HRV parameters reflecting parasympathetic activity were increased in TghSOD1. Pharmacological studies confirmed that the parasympathetic tone was exacerbated and the sympathetic pathway was functional in TghSOD1 mice. A high frequency of atrioventricular block and premature ventricular contractions was observed in TghSOD1. By biochemical assays we found that SOD1 activities were multiplied by 9 and 4 respectively in the heart and brainstem of transgenic mice. A twofold decrease in cholinesterase activity was observed in the heart but not in the brainstem. We demonstrate that SOD1 overexpression induces an ANS dysfunction by an exacerbated vagal tone that may be related to impaired cardiac activity of the cholinesterases and may explain the high occurrence of arrhythmias.     

In vitro photostability and photoprotection studies of a novel 'multi-active' UV-absorber

This paper reports on the synthesis and properties of a new UV-absorber (OC-NO) based on the most popular UV filter worldwide, ethylhexyl methoxycinnamate (OMC) in which the methoxy group has been replaced with a pyrrolidine nitroxide bearing antioxidant activity. This sunscreen active has therefore both UV-absorbing and antioxidant properties which could ideally address both the UV-B and UV-A skin photo-damage. For broad-spectrum coverage, the combinations of OC-NO with two commonly used UV-A absorbers (BMDBM and DHHB) were also studied. The results obtained reveal that OC-NO: (a) is as photostable as OMC after UV-A exposure; (b) acts as free radical scavenger as demonstrated by EPR and chemical studies; (c) reduces UV-A and UV-A+BMDBM induced lipid peroxidation in liposomes and cells, measured as reduced TBARS levels and increased C11-BODIPY red fluorescence, respectively; (d) has comparable antioxidant activity to that of vitamin E and BHT commonly used in skin care formulations; (e) is non-cytotoxic to human skin fibroblasts as assessed with the MTT assay when exposed to increasing doses of UV-A; and (f) OC-NO+DHHB is a promising, photostable broad spectrum UV-filter combination that concomitantly reduces UV-induced free radical damage. These results suggest that nitroxide/antioxidant-based UV-absorbers may pave the way for the utilization of 'multi-active' ingredients in sunscreens thereby reducing the number of ingredients in these formulations.     

Thioredoxins of a parasitic nematode: comparison of the 16- and 12-kDA thioredoxins from Haemonchus contortus

Thioredoxins are a family of small proteins conserved through evolution, which are essential for the maintenance of cellular homeostasis. The "classic" thioredoxin, identified in most species, is a 12-kDa protein with a Cys-Pro-Gly-Cys (CPGC) active site. However, in nematodes a larger protein, 16 kDa, with a Cys-Pro-Pro-Cys (CPPC) active site was identified. We report that in the parasitic nematode Haemonchus contortus, both the 12-kDa (HcTrx1) and the 16-kDa (HcTrx3) species are expressed through the life cycle. However, the HcTrx3 is expressed at higher concentrations. Recombinant HcTrx1 and HcTrx3 were produced and both reduced insulin at a rate similar to that observed with ovine (host) and Escherichia coli thioredoxins and both were regenerated by a mammalian thioredoxin reductase, demonstrating that they have similar thioredoxin activity. Unlike mammalian thioredoxins, both proteins were able to reduce oxidised glutathione and hydrogen peroxide. This suggests essential roles for these proteins in response to oxidative stress and the host immune attack. Analysis of ivermectin-resistant H. contortus showed that expression of both genes were increased in a drug-resistant strain relative to a sensitive strain. Involvement in drug resistance identifies these thioredoxin proteins as potential drug targets for parasite control.