Optimized cultivation of highly-efficient degradation bacterial strains and their degradation ability towards pyrene

Two bacterial strains, Py1 and Py4, have been tamed and isolated through long cultivation with polycyclic aromatic hydrocarbon—pyrene as the single carbon source. It has been proven that they are both highly-efficient pyrene degrading bacteria and both Bacillus sp.. The pyrene degradation ability of separated Py1, Py4 and the consortium of equal Py1 and Py4 was studied in this project. It is shown that pyrene degradation rates were 88% in 10hr by Py1, 84% in 14hr by Py4, and 88% in 8hr by the consortium. It was also determined that the best degradation temperatures were 37°C and pH 7.0 respectively. The influence of different nutrient substrates added in the degradation experiments was also studied. It was shown that sodium salicylate, sodium acetate and yeast extract had obvious simulative effect, but glucose had no obvious effect. __________ Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis (Natural Science Edition) 2006, 39: 71–74 [译自: 南开大学学报 (自然科学版)]     

天麦消渴片通过miRNA改善糖尿病大鼠血糖的机制

目的探讨天麦消渴片对糖尿病大鼠体重、血糖、血脂和胰岛素等相关代谢指标的影响,并且利用miRNA表达谱芯片和实时定量RT-PCR探讨天麦消渴片降血糖的机制。方法 SD大鼠通过高脂饮食/注射STZ法构建糖尿病大鼠模型。将SD大鼠分为小剂量天麦消渴片组[8只,给予50 mg/(kg·d)的天麦消渴片粉末悬浊液]、大剂量天麦消渴片组[8只,给予100 mg/(kg·d)的天麦消渴片粉末悬浊液]、糖尿病模型组(8只,给予等体积生理盐水)和正常对照组(8只,给予等体积生理盐水),均连续灌胃8周。每2周测定SD大鼠空腹血糖(FBG)和体重。7周末进行口服糖耐量实验(OGTT),测空腹和葡萄糖负荷后血糖。8周末测定大鼠空腹血糖、血清胰岛素和血脂水平,观察天麦消渴片对糖尿病大鼠血糖和血脂的改善作用。取大鼠胰腺组织进行miRNA表达谱芯片实验,并运用实时定量RT-PCR验证芯片结果,以期探讨天麦消渴片对糖尿病大鼠降血糖的机制。结果干预后,大剂量天麦消渴片组大鼠较糖尿病模型组空腹血糖和OGTT曲线下面积(AUC)显著下降。干预8周后,大剂量天麦消渴片组空腹血清胰岛素(FINS)和胰岛素抵抗指数(HOMA-IR)较糖尿病模型组显著降低(P0.01)。干预8周后,大剂量天麦消渴片组血总胆固醇(TC)和甘油三酯(TG)较糖尿病模型组显著降低(P0.05)。大剂量天麦消渴片组胰腺较糖尿病模型组有18个miRNA上调,3个miRNA下调。结论天麦消渴片不仅能有效降低糖尿病大鼠FBG,改善胰岛素敏感性,还能调节脂代谢。天麦消渴片可能是通过上调胰腺miR-375和miR-30d水平,刺激胰岛β细胞增殖,抑制胰岛α细胞增殖,增加胰岛素基因表达;上调胰腺let-7b、let-7e、miR-142-5p和miR-375,抑制细胞因子及受体相互作用通路和MAPK通路的功能,从而改善糖尿病大鼠血糖和胰岛素抵抗状态。     

A novel glucose biosensor based on the immobilization of glucose oxidase onto gold nanoparticles-modified Pb nanowires

A novel glucose biosensor was developed, based on the immobilization of glucose oxidase (GOD) with cross-linking in the matrix of bovine serum albumin (BSA) on a Pt electrode, which was modified with gold nanoparticles decorated Pb nanowires (GNPs-Pb NWs). Pb nanowires (Pb NWs) were synthesized by an l-cysteine-assisted self-assembly route, and then gold nanoparticles (GNPs) were attached onto the nanowire surface through –SH–Au specific interaction. The morphological characterization of GNPs-Pb NWs was examined by transmission electron microscopy (TEM). Cyclic voltammetry and chronoamperometry were used to study and to optimize the electrochemical performance of the resulting biosensor. The synergistic effect of Pb NWs and GNPs made the biosensor exhibit excellent electrocatalytic activity and good response performance to glucose. The effects of pH and applied potential on the amperometric response of the biosensor have been systemically studied. In pH 7.0, the biosensor showed the sensitivity of 135.5 μA mM⁻¹ cm⁻², the detection limit of 2 μM (S/N = 3), and the response time <5 s with a linear range of 5–2200 μM. Furthermore, the biosensor exhibits good reproducibility, long-term stability and relative good anti-interference.     

Genetic Variants in the Folate Pathway and the Risk of Neural Tube Defects: A Meta-Analysis of the Published Literature

Background

Neural Tube Defects (NTDs) are among the most prevalent and most severe congenital malformations worldwide. Polymorphisms in key genes involving the folate pathway have been reported to be associated with the risk of NTDs. However, the results from these published studies are conflicting. We surveyed the literature (1996–2011) and performed a comprehensive meta-analysis to provide empirical evidence on the association.

Methods and Findings

We investigated the effects of 5 genetic variants from 47 study populations, for a total of 85 case-control comparisons MTHFR C677T (42 studies; 4374 cases, 7232 controls), MTHFR A1298C (22 studies; 2602 cases, 4070 controls), MTR A2756G (9 studies; 843 cases, 1006 controls), MTRR A66G (8 studies; 703 cases, 1572 controls), and RFC-1 A80G (4 studies; 1107 cases, 1585 controls). We found a convincing evidence of dominant effects of MTHFR C677T (OR 1.23; 95%CI 1.07–1.42) and suggestive evidence of RFC-1 A80G (OR 1.55; 95%CI 1.24–1.92). However, we found no significant effects of MTHFR A1298C, MTR A2756G, MTRR A66G in risk of NTDs in dominant, recessive or in allelic models.

Conclusions

Our meta-analysis strongly suggested a significant association of the variant MTHFR C677T and a suggestive association of RFC-1 A80G with increased risk of NTDs. However, other variants involved in folate pathway do not demonstrate any evidence for a significant marginal association on susceptibility to NTDs.     

Evolution of a desaturase involved in female pheromonal cuticular hydrocarbon biosynthesis and courtship behavior in Drosophila

Drosophila species exhibit polymorphism in female pheromonal cuticular hydrocarbons, with 7-monoenes produced in Drosophila simulans and 7,11-dienes in most populations of Drosophila melanogaster (5,9-dienes in several African populations). A female-biased desaturase, desatF, expressed only in D. melanogaster is involved in the synthesis of 7,11-dienes. We investigated the role of desatF in 5,9-diene flies. We constructed a 5,9-diene strain knock-down for desatF and showed that desatF is involved in 5,9-diene formation. We also studied D. melanogaster/D. simulans hybrids. These hybrid females produced dienes and received normal courtship from D. melanogaster males, but copulation success was reduced. With D. simulans males, courtship was decreased and no copulation occurred. Hybrids with a chromosomal deletion of the D. melanogaster desatF gene had no dienes and received normal courtship from D. simulans males; depending on the D. simulans parental strain, 7-19% of them succeeded in mating. D. simulans desatF promoter region shows 21-23% gaps and 86-89% identity with D. melanogaster promoter region, the coding region 93-94% identity, depending on the strain. These differences could explain the functional polymorphism of desatF observed between both species, contributing to different cuticular hydrocarbon profiles, that constitute an effective barrier between species.     

Increasing Prevalence of Metabolic Syndrome in a Chinese Elderly Population: 2001–2010

Objective

The information on the changes of prevalence of MetS in China is limited. Our objective was to assess a 10-year’s change of the prevalence of MetS in a Chinese elderly population between 2001 and 2010.

Methods

We conducted two cross-sectional surveys in a representative sample of elderly population aged 60 to 95 years in Beijing in 2001 and 2010 respectively. MetS was defined according to the 2009 harmonizing definition.

Results

A total of 2,334 participants (943 male, 1,391 female) in 2001 and 2,102 participants (848 male, 1,254 female) in 2010 completed the survey. The prevalence of MetS was 50.4% (95%CI: 48.4%–52.4%) in 2001 and 58.1% (95%CI: 56.0%–60.2%) in 2010. The absolute change of prevalence of MetS was 7.7% over the 10-year’s period (p<0.001). The syndrome was more common in female than male in both survey years. Among the five components, hypertriglyceridemia and low HDL-C had increased most, with an increase of 14.8% (from 29.4% to 44.2%) and 9.9% (from 28.3% to 38.2%) respectively. The adjusted ORs of MetS for CHD, stroke and CVD were 1.67(95%CI: 1.39–1.99), 1.50(95%CI: 1.19–1.88) and 1.70(95%CI: 1.43–2.01) respectively in 2001, and were 1.74(95%CI: 1.40–2.17), 1.25(95%CI: 0.95–1.63) and 1.52(95%CI: 1.25–1.86) respectively in 2010.

Conclusion

The prevalence of MetS is high and increasing rapidly in this Chinese elderly population. Participants with Mets and its individual components are at significantly elevated ORs for CVD. Urgent public health actions are needed to control MetS and its components, especially for dislipidemia.     

Higher Plasma Myostatin Levels in Cor Pulmonale Secondary to Chronic Obstructive Pulmonary Disease

Objective

To analyze plasma myostatin levels and investigate their relationship with right ventricular (RV) function in patients with cor pulmonale secondary to chronic obstructive pulmonary disease (COPD).

Methods

The study recruited 81 patients with advanced COPD and 40 age-matched controls. The patients were divided into two groups: those with cor pulmonale and those without. Echocardiography was used to evaluate RV function and morphology, and the value of tricuspid annular plane systolic excursion (TAPSE) less than 16 mm was considered RV dysfunction. Plasma myostatin levels were analyzed by enzyme-linked immunosorbent assay, and B-type natriuretic peptide (BNP) levels were analyzed as a comparison of myostatin.

Results

The data detected cor pulmonale in 39/81 patients, with the mean value of TAPSE of 14.3 mm. Plasma myostatin levels (ng/mL) were significantly higher in patients with cor pulmonale (16.68 ± 2.95) than in those without (13.56 ± 3.09), and much higher than in controls (8.79±2.79), with each p<0.01. Significant differences were also found in plasma BNP levels among the three groups (p<0.05). Multivariate regression analysis suggested that myostatin levels were significantly correlated with the values of TAPSE and RV myocardium performance index among the COPD patients, and that BNP levels were significantly correlated only with systolic pulmonary arterial pressure, with each p<0.05.

Conclusions

Plasma myostatin levels are increased in COPD patients who have cor pulmonale. Stronger correlations of plasma myostatin levels with echocardiographic indexes of the right heart suggest that myostatin might be superior to BNP in the early diagnosis of cor pulmonale in COPD.     

模拟湿地系统中土壤氮磷释放的动态研究

温室中建立模拟湿地系统,定期定量用人工污水灌溉１ａ,取污灌土壤测定其所含营养元素,以研究其释放动态．结果显示,Ｐ元素释放的快速反应于浸提１ｈ基本达到平衡,缓慢过程则达到平衡所需的应在浸提２４ｈ以上．Ｎ的解吸与吸附平衡过程也可用Ｐ素释放的快速反应和缓慢过程来解释．持续１ａ的排污并未造成土壤中Ｎ、Ｐ行为的显著改变,也即土壤对人工污水的承受力较大．     

Characterization of the complete mitochondrial genome of the giant silkworm moth, Eriogyna pyretorum (Lepidoptera: Saturniidae)

The complete mitochondrial genome (mitogenome) of Eriogyna pyretorum (Lepidoptera: Saturniidae) was determined as being composed of 15,327 base pairs (bp), including 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a control region. The arrangement of the PCGs is the same as that found in the other sequenced lepidopteran. The AT skewness for the E. pyretorum mitogenome is slightly negative (-0.031), indicating the occurrence of more Ts than As. The nucleotide composition of the E. pyretorum mitogenome is also biased toward A + T nucleotides (80.82%). All PCGs are initiated by ATN codons, except for cytochrome c oxidase subunit 1 and 2 (cox1 and cox2). Two of the 13 PCGs harbor the incomplete termination codon by T. All tRNA genes have a typical clover-leaf structure of mitochondrial tRNA, with the exception of trnS1(AGN) and trnS2(UCN). Phylogenetic analysis among the available lepidopteran species supports the current morphology-based hypothesis that Bombycoidea, Geometroidea, Notodontidea, Papilionoidea and Pyraloidea are monophyletic. As has been previously suggested, Bombycidae (Bombyx mori and Bombyx mandarina), Sphingoidae (Manduca sexta) and Saturniidae (Antheraea pernyi, Antheraea yamamai, E. pyretorum and Caligula boisduvalii) formed a group.