Enrichment and characteristics of mixed methane-oxidizing bacteria from a Chinese coal mine.

In methane-rich environments, methane-oxidizing bacteria usually occur predominantly among consortia including other types of microorganisms. In this study, artificial coal bed gas and methane gas were used to enrich mixed methanotrophic cultures from the soil of a coal mine in China, respectively. The changes in microbial community structure and function during the enrichment were examined. The microbial diversity was reduced as the enrichment proceeded, while the capacity for methane oxidation was significantly enhanced by the increased abundance of methanotrophs. The proportion of type II methanotrophs increased greatly from 7.84 % in the sampled soil to about 50 % in the enrichment cultures, due to the increase of methane concentration. After the microbial community of the cultures got stable, Methylomonas and Methylocystis became the dominant type I and type II methanotrophs, while Methylophilus was the prevailing methylotroph. The sequences affiliated with pigment-producing strains, Methylomonas rubra, Hydrogenophaga sp. AH-24, and Flavobacterium cucumis, could explain the orange appearance of the cultures. Comparing the two cultures, the multi-carbon sources in the artificial coal bed gas caused more variety of non-methanotrophic bacteria, but did not help to maintain the diversity or to increase the quantity and activity of methanotrophs. The results could help to understand the succession and interaction of microbial community in a methane-driven ecosystem.

Brain­derived neurotrophic factor gene polymorphisms are associated with coronary artery disease­related depression and antidepressant response.

Depression is a well­established risk factor for cardiac morbidity and mortality in patients with coronary artery disease (CAD). Previous studies have demonstrated that the level of brain­derived neurotrophic factor (BDNF) is decreased in depressed patients and this depletion may be reversed by antidepressants. Several recent studies have suggested that BDNF is involved in the pathogenesis of CAD. The aim of the present study was to investigate the possible association between seven single nucleotide polymorphisms (SNPs) of the BDNF gene (SNPs; rs16917204, rs6265, rs7103873, rs16917237, rs56164415, rs13306221 and rs10767664) and coronary artery disease­related depression (CAD­D). In the present study, 616 CAD patients without depression (CAD­nD) and 155 patients with CAD­D were recruited, and the response to an eight week sertraline antidepressant treatment regimen was also evaluated. The results demonstrated that a significant association existed between the SNP rs6265, located in exon 4 of the BDNF gene, and CAD­D [χ2=9.634, P=0.002, odds ratio (OR)=1.486, 95% confidence interval (CI)=1.156­1.910]. Another potential association was observed for rs13306221 (χ2=5.194, P=0.023, OR=2.139, 95% CI=1.096­4.175) in the promoter region of the BDNF gene. Strong linkage disequilibrium was observed in block 1 (rs16917204, rs6265; D'>0.9). However, there was no evidence of a significant linkage disequilibrium between the seven SNPs in our sample population. Additionally, carriers of the A allele of rs6265 exhibited improved responses to the sertraline treatment (χ2=8.942, P=0.003, OR=2.136, 95% CI=1.293­3.528). To the best of our knowledge, these results demonstrate, for the first time, the presence of a significant association between BDNF rs6265 and CAD­D, the identification of which may facilitate early diagnosis of CAD­D in the future.

The efficacy and safety of melatonin in concurrent chemotherapy or radiotherapy for solid tumors: a meta-analysis of randomized controlled trials.

BACKGROUND: Recently, melatonin has been associated with cancer both in vitro and in vivo. However, the value of melatonin in the treatment of cancer remains disputable. Hence, we performed a systematic review of randomized controlled trials (RCTs) of melatonin in solid tumor cancer patients and observed its effect on tumor remission, 1-year survival, and side effects due to radiochemotherapy. METHODS: An electronic search was conducted using the databases Pubmed, Medline, EMBASE, Cochrane library, and CNKI, from inception to November 2011. Trials using melatonin as adjunct treatment concurrent with chemotherapy or radiotherapy for cancer were included. Pooled relative risk (RR) for the tumor remission, 1-year survival, and radiochemotherapy-related side effects were calculated using the software Revman 5.0. RESULTS: The search strategy identified 8 eligible RCTs (n = 761), all of which studied solid tumor cancers. The dosage of melatonin used in the 8 included RCTs was 20 mg orally, once a day. Melatonin significantly improved the complete and partial remission (16.5 vs. 32.6%; RR = 1.95, 95% CI, 1.49-2.54; P < 0.00001) as well as 1-year survival rate (28.4 vs. 52.2%; RR = 1.90; 95% CI, 1.28-2.83; P = 0.001), and dramatically decreased radiochemotherapy-related side effects including thrombocytopenia (19.7 vs. 2.2%; RR = 0.13; 95% CI, 0.06-0.28; P < 0.00001), neurotoxicity (15.2 vs. 2.5%; RR = 0.19; 95% CI, 0.09-0.40; P < 0.0001), and fatigue (49.1 vs. 17.2%; RR = 0.37; 95% CI, 0.28-0.48; P < 0.00001). Effects were consistent across different types of cancer. No severe adverse events were reported. CONCLUSIONS: Melatonin as an adjuvant therapy for cancer led to substantial improvements in tumor remission, 1-year survival, and alleviation of radiochemotherapy-related side effects.

High-rate conversion of methane to methanol by Methylosinus trichosporium OB3b.

Methanol was produced from methane with a high conversion rate using a high cell density process with Methylosinus trichosporium OB3b in the presence of a high concentration of phosphate buffer. More than 1.1 g/L methanol accumulated in the reaction media under optimized reaction conditions (17 g dry cell/L, 400 mmol/L phosphate, and 10 mmol/L MgCl(2)) in the presence of 20 mmol/L sodium formate. The conversion rate of methane was over 60%. About 0.95 g/L methanol was produced when the biotransformation was carried out in a membrane aerated reactor into which methane and oxygen were introduced via two separate dense silicone tubing. Our results provide an efficient method and a promising process for high-rate conversion of methane to methanol.

A new jacaranone derivative from Senecio scandens var. incisus.

A new jacaranone derivative, 2-(1,6-dihydroxy-4-oxocyclohex-2-enyl) acetic acid (1), has been isolated from the whole plants of Senecio scandens var. incisus, together with three known compounds: 2'-(p-hydroxyl-cinnamoyl)-6'-jacaranone-D-glucopyranoside (2), 2'-caffeoyl-6'-jacaranone-D-glucopyranoside (3) and kampferol-3-rhamnoside (4). Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with the related known compounds. Cytotoxic activities of 1 against three human tumour cell lines have been evaluated by the MTT method.