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41.
Haixiang Wei Gan Shen Xiaolong Deng Dong Lou Binbin Sun Hao Wu Long Long Tao Ding Jian Zhao 《Cell and tissue banking》2013,14(4):699-706
Rheumatoid arthritis (RA) is the most common degenerative arthritic cartilage and represents a disease where the prospect of stem cell therapy offers considerable hope. Currently, bone marrow (BM) represents the major source of mesenchymal stem cells (MSCs) for cell therapy. In the pathology of RA, the pro-inflammatory cytokines, such as interleukin 6 (IL-6) play a pivotal role. To investigate the direct role of IL-6 in the chondrogenic differentiation of murine MSCs (mMSCs), we isolate MSCs from the murine bone marrow, and induce MSCs chondrogenesis with different concentrations of IL-6 in vitro. Through detecting the histological and histochemical qualities of the aggregates, we demonstrate that IL-6 inhibited the differentiation of MSCs into chondrocytes in the dose-dependence manner. These findings suggest that possible strategies for improving the clinical outcome of cartilage repair procedures. 相似文献
42.
Tubificidae is often used in the wastewater treatment systems to minimize the sludge production because it can be fed on the activated sludge. The process conditions have effect on the growth, reproduction, and sludge reduction efficiency of Tubificidae. The effects of the water quality, density of worms, pH, temperature and dissolved oxygen (DO) concentration on the respiration rate of Tubificidae were investigated to determine the optimal conditions for the growth and metabolism of the worms and reveal the mechanisms involving the efficient sludge reduction in terms of these conditions. It was observed that the respiration rate was highest in the water discharged from an ecosystem that included symbiotic Tubificidae and microbes and was lowest in distilled water. Considering density of the worms, the highest rate was 81.72±5.12 mg O2/g(dry weight)·h·L with 0.25 g (wet weight) of worms in 1 L test flask. The maximum Tubificidae respiration rate was observed at a pH of 8.0±0.05, a rate that was more than twice as high as those observed at other pH values. The respiration rate increased in the temperature range of ∼8°C–22°C, whereas the rate declined in the temperature range of ∼22°C–30°C. The respiration rate of Tubificidae was very high for DO range of ∼3.5–4.5 mg/L, and the rates were relatively low for out of this DO range. The results of this study revealed the process conditions which influenced the growth, and reproduction of Tubificidae and sludge reduction at a microscopic level, which could be a theoretical basis for the cultivation and application of Tubificidae in wastewater treatment plants. 相似文献
43.
Taoxiang Zhang Haizhen Wang Laosheng Wu Jun Lou Jianjun Wu Philip C. Brookes Jianming Xu 《PloS one》2013,8(12)
Escherichia coli O157:H7 (E. coli O157:H7) is recognized as a hazardous microorganism in the environment and for public health. The E. coli O157:H7 survival dynamics were investigated in 12 representative soils from Jiangsu Province, where the largest E. coli O157:H7 infection in China occurred. It was observed that E. coli O157:H7 declined rapidly in acidic soils (pH, 4.57 – 5.14) but slowly in neutral soils (pH, 6.51 – 7.39). The survival dynamics were well described by the Weibull model, with the calculated td value (survival time of the culturable E. coli O157:H7 needed to reach the detection limit of 100 CFU g−1) from 4.57 days in an acidic soil (pH, 4.57) to 34.34 days in a neutral soil (pH, 6.77). Stepwise multiple regression analysis indicated that soil pH and soil organic carbon favored E. coli O157:H7 survival, while a high initial ratio of Gram-negative bacteria phospholipid fatty acids (PLFAs) to Gram-positive bacteria PLFAs, and high content of exchangeable potassium inhibited E. coli O157:H7 survival. Principal component analysis clearly showed that the survival profiles in soils with high pH were different from those with low pH. 相似文献
44.
Chemical signaling between organisms is a ubiquitous and evolutionarily dynamic process that helps to ensure mate recognition, location of nutrients, avoidance of toxins, and social cooperation. Evolutionary changes in chemical communication systems progress through natural variation within the organism generating the signal as well as the responding individuals. A promising yet poorly understood system with which to probe the importance of this variation exists between D. melanogaster and S. cerevisiae. D. melanogaster relies on yeast for nutrients, while also serving as a vector for yeast cell dispersal. Both are outstanding genetic and genomic models, with Drosophila also serving as a preeminent model for sensory neurobiology. To help develop these two genetic models as an ecological model, we have tested if - and to what extent - S. cerevisiae is capable of producing polymorphic signaling through variation in metabolic volatiles. We have carried out a chemical phenotyping experiment for 14 diverse accessions within a common garden random block design. Leveraging genomic sequences for 11 of the accessions, we ensured a genetically broad sample and tested for phylogenetic signal arising from phenotypic dataset. Our results demonstrate that significant quantitative differences for volatile blends do exist among S. cerevisiae accessions. Of particular ecological relevance, the compounds driving the blend differences (acetoin, 2-phenyl ethanol and 3-methyl-1-butanol) are known ligands for D. melanogasters chemosensory receptors, and are related to sensory behaviors. Though unable to correlate the genetic and volatile measurements, our data point clear ways forward for behavioral assays aimed at understanding the implications of this variation. 相似文献
45.
Yi-Yan Chen Ying Zhu Qiu-Hong Wan Ji-Kang Lou Wen-Jing Li Yun-Fa Ge Sheng-Guo Fang 《PloS one》2013,8(7)
Genetic variation plays a significant role in maintaining the evolutionary potential of a species. Comparing the patterns of adaptive and neutral diversity in extant populations is useful for understanding the local adaptations of a species. In this study, we determined the fine-scale genetic structure of 6 extant populations of the giant panda (Ailuropoda melanoleuca) using mtDNA and DNA fingerprints, and then overlaid adaptive variations in 6 functional Aime-MHC class II genes (DRA, DRB3, DQA1, DQA2, DQB1, and DQB2) on this framework. We found that: (1) analysis of the mtDNA and DNA fingerprint-based networks of the 6 populations identified the independent evolutionary histories of the 2 panda subspecies; (2) the basal (ancestral) branches of the fingerprint-based Sichuan-derived network all originated from the smallest Xiaoxiangling (XXL) population, suggesting the status of a glacial refuge in XXL; (3) the MHC variations among the tested populations showed that the XXL population exhibited extraordinary high levels of MHC diversity in allelic richness, which is consistent with the diversity characteristics of a glacial refuge; (4) the phylogenetic tree showed that the basal clades of giant panda DQB sequences were all occupied by XXL-specific sequences, providing evidence for the ancestor-resembling traits of XXL. Finally, we found that the giant panda had many more DQ alleles than DR alleles (33∶13), contrary to other mammals, and that the XXL refuge showed special characteristics in the DQB loci, with 7 DQB members of 9 XXL-unique alleles. Thus, this study identified XXL as a glacial refuge, specifically harboring the most number of primitive DQB alleles. 相似文献
46.
Fangyou Yu Ying Liu Yuanyuan Xu Yongpeng Shang Danping Lou Zhiqiang Qin Chris Parsons Wu Zhou Xiaoying Huang Yuping Li Longhua Hu Liangxing Wang 《PloS one》2013,8(12)
Panton-Valentine leukocidin (PVL; gene designation lukF/S-PV) is likely an important virulence factor for Staphylococcus aureus (S. aureus), as qualitative expression of the protein correlates with severity for specific clinical presentations, including skin and soft tissue infections (SSTIs). Development of genetic approaches for risk-assessment of patients with S. aureus infections may prove clinically useful, and whether lukF/S-PV gene expression correlates with specific clinical presentations for S. aureus has been largely unexplored. In the present study, we quantified lukS-PV mRNA among 96 S. aureus isolates to determine whether expression levels correlated with specific clinical presentations in adults and children. Expression level of lukS-PV mRNA among isolates from skin and soft tissue infections (SSTIs) was significantly greater than among isolates from blood stream infection (BSIs), and expression level of lukS-PV mRNA among BSI isolates from children was significantly greater than for BSI isolates among adults. Moreover, expression level of lukS-PV mRNA among community-acquired (CA) isolates was significantly greater than for hospital-acquired (HA) isolates. These data justify additional studies to determine the potential clinical utility for lukS-PV mRNA quantification as a predictive tool for severity of S. aureus infection. 相似文献
47.
Xiao‐Bin Li Fei Xie Shan‐Shan Liu Ying Li Jin‐Chuan Zhou Yong‐Qing Liu Hui‐Qing Yuan Hong‐Xiang Lou 《化学与生物多样性》2013,10(7):1193-1201
Bioactivity‐guided fractionation of the cytotoxic extract of Aspergillus niger, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph .) Schiffn ., afforded five new naphtho‐γ‐pyrones, rubrofusarin‐6‐O‐α‐D ‐ribofuranoside ( 1 ), (R)‐10‐(3‐succinimidyl)‐TMC‐256A1 ( 2 ), asperpyrone E ( 3 ), isoaurasperone A ( 4 ), and isoaurasperone F ( 5 ), as well as four known ones, dianhydroaurasperone C ( 6 ), aurasperone D ( 7 ), asperpyrone D ( 8 ), and asperpyrone A ( 9 ), together with a cytotoxic cyclic pentapeptide, malformin A1 ( 10 ). Their structures were determined by extensive spectroscopic analysis. The absolute configurations of dimeric naphtho‐γ‐pyrones 3 – 9 were also determined by analysis of their respective CD spectra. 相似文献
48.
The endolithic environment is a ubiquitous microbial habitat for microorganisms, such as lichens, Cyanobacteria and fungi, and it provides mineral nutrients and growth surfaces. In extremely environments, such as hot and cold desert, endolithic communities are often the main form of life. More recently, endolithic microbial communities have been observed inhabiting a variety of rock types ranging from hard granite to porous rocks such as basalt, dolomite, limestone, sandstone and granites. Regardless of geographic location and rock type, each of these habitats is characterized by a subsurface microclimate that prevents endolithic microorganisms growth. Photosynthesis-based endolithic microbial communities commonly inhabit the outer millimeters to centimeters of rocks exposed to the surface. The ability to fix carbon dioxide and in some cases atmospheric dinitrogen, gives the Cyanobacteria a clear competitive advantage over heterotrophic bacteria, so it is been called the main primary producer. Light quality and intensity appear to be the main determinant of the maximum depth to which growth occurs in endolithic phototrophic communities. Valleys of Fantastic Rocks in Bole is close to Alashankou Port of Xinjiang which belongs to extreme continental climate. In order to investigate the structure, composition and diversity of endolithic bacterial community in exposed granitic porphyry in the Valleys of Fantastic Rocks, environmental DNA was directly extracted from granite rock, the 16S rRNA genes were amplified from the total DNA by PCR with bacterial-specific primers, and an endolithic bacterial clone library was constructed. Positive clones were randomly selected from the library and identified by Restriction Fragment Length Polymorphism (RFLP). The unique rRNA types clones were sequenced, analysised and then constructed phylogenetic tree. In total, 129 positive clones were screened and grouped into 46 operational taxonomic unites (OTUs). The clone coverage C value was 89.15%, indicating that most of the estimated endolithic bacterial diversity was sampled. BLAST analysis indicated that 46 OTUs were divided into seven phyla (Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Planctomycetes, Proteobacteria) and five unknown groups. Cyanobacteria (43%), especially the Gp I, form the functional basis for an endolithic bacteria community which contain a wide spectrum species of chemotrophic bacteria (33%) with mainly Actinobacteria, α-Proteobacteria, Acidobacteria. Additionally, most clones that derived from the endolithic bacteria clone library showed high similarity to the sequence deposited in GenBank database with 97%–99%. Besides, 35% of the clones showed less than 97% of sequence similarity, of which 12% sequences were affiliated to genus Rubrobacter. The results suggested that endolithic bacteria in Valleys of Fantastic Rocks in Xinjiang were highly diverse in species richness, and maybe have a diversity of potential novel species and lineages. 相似文献
49.
Xun Liu Yanni Wang Cheng Wang Chenggang Shi Cailian Cheng Jinxia Chen Huijuan Ma Linsheng Lv Lin Li Tanqi Lou 《PloS one》2013,8(11)