Quantification of mcrA by fluorescent PCR in methanogenic and methanotrophic microbial communities

A quantitative fluorogenic PCR method for detecting methanogenic and methanotrophic orders was established using a refined primer set for the methyl coenzyme M reductase subunit A gene (mcrA). The method developed was applied to several microbial communities in which diversity and abundance of methanogens or anaerobic methanotrophs (ANMEs) was identified by 16S rRNA gene clone analysis, and strong correlations between the copy numbers of mcrA with those of archaeal 16S rRNA genes in the communities were observed. The assay can be applied to detecting and assessing the abundance of methanogens and/or ANMEs in anoxic environments that could not be detected by 16S rRNA gene sequence analyses.     

β—连接素在膀胱移行细胞癌中表达的意义

目的 探讨β－连接素（β－ctenin）蛋白的表达及其与膀胱移行细胞癌组织学特征和侵袭的关系。方法 采用免疫组化SP法检测46例膀胱移行细胞癌组织中的β－ctenin的表达。结果 正常膀胱粘膜上皮细胞全部表达β－ctenin,膀胱移行细胞癌中β－ctenin的表达率分别是“＋＋＋”为52．1％（24／46）,“＋＋”为32．6％（15／46）,“＋”O 15．2％（7／46）。侵袭型的膀胱移行细胞癌中β－ctenin表达率是“＋＋＋”为11．1％（1／9）,显著低于乳头状型者（P＜0．01）。结论 β－ctenin的表达与膀胱移行细胞组织学特征及侵袭有相关性,可作为判断肿瘤恶笥肿瘤、侵袭、预后的价值指标。     

Decreased Reactive Oxygen Species Production in Cells with Mitochondrial Haplogroups Associated with Longevity

Mitochondrial DNA (mtDNA) is highly polymorphic, and its variations in humans may contribute to individual differences in function. Zhang and colleagues found a strikingly higher frequency of a C150T transition in the D-loop of mtDNA from centenarians and twins of an Italian population, and also demonstrated that this base substitution causes a remodeling of the mtDNA 151 replication origin in human leukocytes and fibroblasts [1]. The C150T transition is a polymorphism associated with several haplogroups. To determine whether haplogroups that carry the C150T transition display any phenotype that may be advantageous for longevity, we analyzed cybrids carrying or not the C150T transition. These cybrids were obtained by fusing cytoplasts derived from human fibroblasts with human mtDNA-less cells (ρ⁰ cells). We chose for cybrid construction and analysis haplogroup-matched pairs of fibroblast strains containing or not the C150T transition. In particular, we used, as one pair of mtDNA donors, a fibroblast strain of the U3a haplogroup, carrying the C150T transition and a strain of the U-K2 haplogroup, without the C150T transition, and as another pair, fibroblasts of the J2b haplogroup, carrying the C150T transition and of the J1c haplogroup, without the C150T transition. We have found no association of respiratory capacity, mtDNA level, mitochondrial gene expression level, or growth rate with the presence of the C150T transition. However, we have found that the cybrids with haplogroups that include the C150T transition have in common a lower reactive oxygen species (ROS) production rate than the haplogroup-matched cybrids without that transition. Thus, the lower ROS production rate may be a factor in the increased longevity associated with the U and the J2 haplogroups. Of further interest, we found that cybrids with the U3a haplogroup exhibited a higher respiration rate than the other cybrids examined.     

Two lignan dimers from bamboo stems (Phyllostachys edulis)

Phyllostadimers A and B, two bis-lignans in which the two lignan units are directly connected by a C-C bond, were isolated from stems of bamboo, Phyllostachys edulis. Their structures were determined on the basis of spectral evidence. In addition, 14 known compounds were also obtained throughout the investigation. Phyllostadimer A significantly inhibited liposomal lipid peroxidation.     

The genome characteristics and predicted function of methyl-group oxidation pathway in the obligate aceticlastic methanogens, Methanosaeta spp

In this work, we report the complete genome sequence of an obligate aceticlastic methanogen, Methanosaeta harundinacea 6Ac. Genome comparison indicated that the three cultured Methanosaeta spp., M. thermophila, M. concilii and M. harundinacea 6Ac, each carry an entire suite of genes encoding the proteins involved in the methyl-group oxidation pathway, a pathway whose function is not well documented in the obligately aceticlastic methanogens. Phylogenetic analysis showed that the methyl-group oxidation-involving proteins, Fwd, Mtd, Mch, and Mer from Methanosaeta strains cluster with the methylotrophic methanogens, and were not closely related to those from the hydrogenotrophic methanogens. Quantitative PCR detected the expression of all genes for this pathway, albeit ten times lower than the genes for aceticlastic methanogenesis in strain 6Ac. Western blots also revealed the expression of fwd and mch, genes involved in methyl-group oxidation. Moreover, (13)C-labeling experiments suggested that the Methanosaeta strains might use the pathway as a methyl oxidation shunt during the aceticlastic metabolism. Because the mch mutants of Methanosarcina barkeri or M. acetivorans failed to grow on acetate, we suggest that Methanosaeta may use methyl-group oxidation pathway to generate reducing equivalents, possibly for biomass synthesis. An fpo operon, which encodes an electron transport complex for the reduction of CoM-CoB heterodisulfide, was found in the three genomes of the Methanosaeta strains. However, an incomplete protein complex lacking the FpoF subunit was predicted, as the gene for this protein was absent. Thus, F(420)H(2) was predicted not to serve as the electron donor. In addition, two gene clusters encoding the two types of heterodisulfide reductase (Hdr), hdrABC, and hdrED, respectively, were found in the three Methanosaeta genomes. Quantitative PCR determined that the expression of hdrED was about ten times higher than hdrABC, suggesting that hdrED plays a major role in aceticlastic methanogenesis.     

Identification of genome-wide variations among three elite restorer lines for hybrid-rice

Rice restorer lines play an important role in three-line hybrid rice production. Previous research based on molecular tagging has suggested that the restorer lines used widely today have narrow genetic backgrounds. However, patterns of genetic variation at a genome-wide scale in these restorer lines remain largely unknown. The present study performed re-sequencing and genome-wide variation analysis of three important representative restorer lines, namely, IR24, MH63, and SH527, using the Solexa sequencing technology. With the genomic sequence of the Indica cultivar 9311 as the reference, the following genetic features were identified: 267,383 single-nucleotide polymorphisms (SNPs), 52,847 insertion/deletion polymorphisms (InDels), and 3,286 structural variations (SVs) in the genome of IR24; 288,764 SNPs, 59,658 InDels, and 3,226 SVs in MH63; and 259,862 SNPs, 55,500 InDels, and 3,127 SVs in SH527. Variations between samples were also determined by comparative analysis of authentic collections of SNPs, InDels, and SVs, and were functionally annotated. Furthermore, variations in several important genes were also surveyed by alignment analysis in these lines. Our results suggest that genetic variations among these lines, although far lower than those reported in the landrace population, are greater than expected, indicating a complicated genetic basis for the phenotypic diversity of the restorer lines. Identification of genome-wide variation and pattern analysis among the restorer lines will facilitate future genetic studies and the molecular improvement of hybrid rice.     

Use of apple seed meal as a new source of beta-glucosidase for enzymatic glucosylation of 4-substituted benzyl alcohols and tyrosol in monophasic aqueous-dioxane medium

A facile method for enzymatic glycosylation of 4-substituted benzyl alcohols and tyrosol with glucose in a monophasic aqueous-dioxane medium was reported, using a crude meal of apple seed as a new catalyst. The corresponding beta-d-glucosides were synthesized in moderate yields (13.1-23.1%), among which the salidroside was obtained in 15.8% yield.     

Nuclear Receptor Nur77 Facilitates Melanoma Cell Survival under Metabolic Stress by Protecting Fatty Acid Oxidation

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Study of thermodynamic parameters for solubilization of plant sterol and stanol in bile salt micelles

We investigated the difference between the molecular structures of plant sterols and stanols that affect the solubilization of cholesterol in bile salt micelles (in vitro study). First, the aqueous solubility of beta-sitosterol, beta-sitostanol, and campesterol was determined by considering the specific radioactivity by using a fairly small quantity of each radiolabeled compound. The order of their aqueous solubilities was as follows: cholesterol > campesterol > beta-sitostanol > beta-sitosterol. The maximum solubility of cholesterol and the above mentioned sterol/stanol in sodium taurodeoxycholate and sodium taurocholate solutions (single solubilizate system) was measured. Moreover, the preferential solubilization of cholesterol in bile salt solutions was systematically studied by using different types of plant sterols/stanols. The solubilization results showed that the cholesterol-lowering effect was similar for sterols and stanol. Thermodynamic analysis was applied to these experimental results. The Gibbs energy change (Delta G degrees ) for the solubilization of plant sterols/stanols showed a negative value larger than that for cholesterol.     

Effects of object color stimuli on human brain activities in perception and attention referred to EEG alpha band response

This study was designed to investigate the physiological effects of color in terms of blood pressure and the results of electroencephalogram (EEG) as subjects looked at the sheets of paper of various colors. A questionnaire was also used to assess psychological effects. Three colors (red, green, blue) were shown to each subject in randomized order. The various colors showed distinctly different effects on the mean power of the alpha band, theta band, and on the total power in the theta-beta EEG bandwidth and alpha attenuation coefficient (AAC). Scores of the subjective evaluations concerning heavy, excited, and warm feelings also indicated significant differences between red and blue conditions. Against to our prediction, blue elicited stronger arousal than did red as expressed by the results of AAC and the mean power of the alpha band, which conflicted with the results of the subjective evaluations scores. This phenomenon might be caused by bluish light's biological activating effect. The powers of the alpha band, and the theta band, and the total power of the theta-beta bandwidth as measured by EEG showed larger values while the subjects looked at red paper than while they looked at blue paper. This indicated that red possibly elicited an anxiety state and therefore caused a higher level of brain activity in the areas of perception and attention than did the color blue. Red paper's effect to activate the central cortical region with regard to perception and attention was considerably more distinguishable than was the biological activating effect of bluish light in our study.