Assessment of the stability of cell-surface components of microorganisms by MALDI-TOF-MS following preservation on lenticule discs

Strains representing the species Campylobacter coli, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enterica, and Staphylococcus aureus were randomly selected to assess the consistency of cells preserved on lenticule discs to those archived in traditional freeze-dried ampoules. Each matched pair was cultured using identical conditions and analysed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS) to profile the surface-associated molecules of the cells. In addition, the cytosolic/membrane-bound proteins of C. coli and S. aureus strains were further analysed by surface-enhanced laser desorption/ionization time-of-flight MS. The mass spectral profiles in all cases showed a high degree of concordance between cells preserved by both methods and suggest that the properties of cells preserved on lenticule disc are consistent with those archived by the traditional method of freeze-drying.     

Dependence of plasma alpha-tocopherol flux on very low-density triglyceride clearance in humans

To evaluate the effect of dietary fat-induced alterations in triglyceride (TG) metabolism on plasma and very low-density lipoprotein (VLDL)-alpha-tocopherol, nine healthy males (mean +/- SEM, age: 36 +/- 3 years, BMI: 24.7 +/- 1.1) consumed a 35%-fat diet (control) for one week followed by a 15% low-fat, high-carbohydrate diet for 5 weeks. After each dietary phase, the subjects ingested an evening meal along with a 50 mg capsule of (2)H(6)-RRR-alpha-tocopheryl acetate; blood samples were drawn over a 24 h period while the subjects remained fasted. Low-fat feeding increased fasting plasma TG concentrations by 53% (116 +/- 27 to 178 +/- 32, mg/dl, p < 0.0001) primarily by reducing VLDL-TG clearance. Total plasma alpha-tocopherol concentrations (labeled + unlabeled) were unchanged (25.8 +/- 2.3 vs. 26.4 +/- 3.0 nmol/ml plasma) and no differences between the diets were observed for plasma (2)H(6)-alpha-tocopherol concentration (4.8 +/- 0.6 nmol/ml, for both diets) or enrichments (18.1 +/- 1.8% average for both diets). However, low-fat feeding significantly increased the amount of alpha-tocopherol in the VLDL fraction (43%, p = 0.04) in concert with elevations in VLDL-apoB and TG. The alpha-tocopherol and TG content of VLDL varied in parallel in individual subjects and fractional replacement rates and clearance of alpha-tocopherol and TG in VLDL were closely correlated. Kinetic parameters were decreased by 32-39% from high-fat to low-fat. These data suggest that vitamin E bioavailability is similar between a 15 and 35% fat diet, with a redistribution of alpha-tocopherol in lipoproteins occurring during low-fat feeding (increased in the VLDL fraction, reduced in the other lipoproteins), and transfer of alpha-tocopherol from VLDL depends upon TG removal from the particle, consistent with previous observations in vitro and in animal studies.     

EFFECTS OF OXYGEN CONCENTRATION AND PRESSURE ON Drosophila melanogaster: OXIDATIVE STRESS,MITOCHONDRIAL ACTIVITY,AND SURVIVORSHIP

Organisms are known to be equipped with an adaptive plasticity as the phenotype of traits in response to the imposed environmental challenges as they grow and develop. In this study, the effects of extreme changes in oxygen availability and atmospheric pressure on physiological phenotypes of Drosophila melanogaster were investigated to explore adaptation mechanisms. The changes in citrate synthase activity (CSA), lifespan, and behavioral function in different atmospheric conditions were evaluated. In the CAS test, hyperoxia significantly increased CSA; both hypoxia and hyperbaric conditions caused a significant decrease in CSA. In the survivorship test, all changed atmospheric conditions caused a significant reduction in lifespan. The lifespan reduced more after hypoxia exposure than after hyperbaria exposure. In behavioral function test, when mechanical agitation was conducted, bang‐sensitive flies showed a stereotypical sequence of initial muscle spasm, paralysis, and recovery. The percentage of individuals that displayed paralysis or seizure was measured on the following day and after 2 weeks from each exposure. The majority of flies showed seizure behavior 15 days after exposure, especially after 3 h of exposure. The percentage of individuals that did not undergo paralysis or seizure and was able to move in the vial, was also tested. The number of flies that moved and raised the higher level of the vial decreased after exposure. Animal's speed decreased significantly 15 days after exposure to extreme environmental conditions. In summary, the alteration of oxygen availability and atmospheric pressure may lead to significant changes in mitochondria mass, lifespan, and behavioral function in D. melanogaster.     

Synergistic plant-microbes interactions in the rhizosphere: a potential headway for the remediation of hydrocarbon polluted soils

Soil pollution is an unavoidable evil; many crude-oil exploring communities have been identified to be the most ecologically impacted regions around the world due to hydrocarbon pollution and their concurrent health risks. Several clean-up technologies have been reported on the removal of hydrocarbons in polluted soils but most of them are either very expensive, require the integration of advanced mechanization and/or cannot be implemented in small scale. However, “Bioremediation” has been reported as an efficient, cost-effective and environment-friendly technology for clean-up of hydrocarbon”s contaminated soils. Here, we suggest the implementation of synergistic mechanism of bioremediation such as the use of rhizosphere mechanism which involves the actions of plant and microorganisms, which involves the exploitation of plant and microorganisms for effective and speedy remediation of hydrocarbon”s contaminated soils. In this mechanism, plant”s action is synergized with the soil microorganisms through the root rhizosphere to promote soil remediation. The microorganisms benefit from the root metabolites (exudates) and the plant in turn benefits from the microbial recycling/solubilizing of mineral nutrients. Harnessing the abilities of plants and microorganisms is a potential headway for cost-effective clean-up of hydrocarbon”s polluted sites; such technology could be very important in countries with great oil producing activities/records over many years but still developing.     

基因工程改善植物生物质能利用的研究进展

利用植物木质纤维资源发酵产乙醇越来越受到人们的重视,但是要达到工业生产仍然存在很多难题。最近在利用植物基因工程技术改善植物自身性状,以利于能源植物的研究方面取得了一定的进展,这些研究包括减少植物自身细胞壁中的木质素含量、细胞中积累表达纤维素酶和木聚耱酶等的方法,使产生的生物质更利于降解利用。     

Impact of Dissolved Oxygen during UV-Irradiation on the Chemical Composition and Function of CHO Cell Culture Media

Ultraviolet (UV) irradiation is advantageous as a sterilization technique in the biopharmaceutical industry since it is capable of targeting non-enveloped viruses that are typically challenging to destroy, as well as smaller viruses that can be difficult to remove via conventional separation techniques. In this work, we investigated the influence of oxygen in the media during UV irradiation and characterized the effect on chemical composition using NMR and LC-MS, as well as the ability of the irradiated media to support cell culture. Chemically defined Chinese hamster ovary cell growth media was irradiated at high fluences in a continuous-flow UV reactor. UV-irradiation caused the depletion of pyridoxamine, pyridoxine, pyruvate, riboflavin, tryptophan, and tyrosine; and accumulation of acetate, formate, kynurenine, lumichrome, and sarcosine. Pyridoxamine was the only compound to undergo complete degradation within the fluences considered; complete depletion of pyridoxamine was observed at 200 mJ/cm². Although in both oxygen- and nitrogen-saturated media, the cell culture performance was affected at fluences above 200 mJ/cm², there was less of an impact on cell culture performance in the nitrogen-saturated media. Based on these results, minimization of oxygen in cell culture media prior to UV treatment is recommended to minimize the negative impact on sensitive media.     

隐喻加工复合模式的ERP研究

本研究使用S1→S2范式研究中国人大脑隐喻加工模式是否与"等级显性理论"一致。被试对隐喻匹配任务和不相关匹配模式进行"是"和"否"隐喻的判断,同时脑电设备记录他们进行任务加工时的事件相关电位(ERP)。通过对相关电极N400的分析发现,右脑加工两个任务时,激活程度呈递增的趋势,与"等级显性理论"一致。另外,两个任务中顶叶空间加工区参与程度的差异说明,隐喻意义的整合需要对相似性、熟悉度等确定后再进行空间联系。     

Relationship between Smoking and Obesity: A Cross-Sectional Study of 499,504 Middle-Aged Adults in the UK General Population

Background

There is a general perception that smoking protects against weight gain and this may influence commencement and continuation of smoking, especially among young women.

Methods

A cross-sectional study was conducted using baseline data from UK Biobank. Logistic regression analyses were used to explore the association between smoking and obesity; defined as body mass index (BMI) >30kg/m². Smoking was examined in terms of smoking status, amount smoked, duration of smoking and time since quitting and we adjusted for the potential confounding effects of age, sex, socioeconomic deprivation, physical activity, alcohol consumption, hypertension and diabetes.

Results

The study comprised 499,504 adults aged 31 to 69 years. Overall, current smokers were less likely to be obese than never smokers (adjusted OR 0.83 95% CI 0.81-0.86). However, there was no significant association in the youngest sub-group (≤40 years). Former smokers were more likely to be obese than both current smokers (adjusted OR 1.33 95% CI 1.30-1.37) and never smokers (adjusted OR 1.14 95% CI 1.12-1.15). Among smokers, the risk of obesity increased with the amount smoked and former heavy smokers were more likely to be obese than former light smokers (adjusted OR 1.60, 95% 1.56-1.64, p<0.001). Risk of obesity fell with time from quitting. After 30 years, former smokers still had higher risk of obesity than current smokers but the same risk as never smokers.

Conclusion

Beliefs that smoking protects against obesity may be over-simplistic; especially among younger and heavier smokers. Quitting smoking may be associated with temporary weight gain. Therefore, smoking cessation interventions should include weight management support.