Sulfate-reducing bacteria in leachate-polluted aquifers along the shore of the East China Sea.

The diversity of sulfate-reducing bacteria (SRB) in the aquifer underlying the Laogang Landfill along the shore of the East China Sea was investigated. The DNA extracted from 15 groundwater samples was subjected to PCR amplification of the dissimilatory sulfite reductase (dsr) gene. Full-length dsrAB amplicons (approximately 1.9 kb) were then used to construct 4 clone libraries, while the dsrB amplicons (approximately 350 bp) were used for denaturing gradient gel electrophoresis (DGGE) analysis. The clones in the 4 libraries covered all cultured SRB lineages, as well as a deeply branching clade not affiliated with any cultured SRB. In addition, nearly 80% of the 388 clones in the 4 libraries were similar to sequences of the Deltaproteobacteria, Desulfobacteriaceae, Desulfovibrionales, Syntrophaceae, and Desulfobulbaceae. Furthermore, a wide variety of marine SRB was detected, which indicated that seawater has infiltrated the aquifer. Indeed, the DGGE profiles revealed obvious variations in SRB diversity among the 15 samples, which clustered in accordance with the sulfate concentration of the samples ([SO4(2-)]). Moreover, the sulfate concentrations and SRB diversity along the leachate plume did not show regular variation, which suggests the impact of both groundwater flow and seawater intrusion.

Investigation of total bacterial and ammonia-oxidizing bacterial community composition in a full-scale aerated submerged biofilm reactor for drinking water pretreatment in China.

The community composition of total bacteria and ammonia-oxidizing bacteria in a full-scale aerated submerged biofilm reactor for drinking water pretreatment was characterized by analysis of 16S rRNA gene and the functional gene amoA, respectively. Sampling was performed in February and in July. 16S rRNA gene clone libraries revealed 13 bacterial divisions. At both sampling dates, the majority of clone sequences were related to the Alpha- and Betaproteobacteria. A minor proportion belonged to the following groups: Gammaproteobacteria, Deltaproteobacteria, Nitrospira, Firmicutes, Acidobacteria, Verrucomicrobia, Actinobacteria, Planctomycetes, Chloroflexi, Gemmatimonadetes and the Cytophaga-Flavobacterium-Bacteroides group. Some sequences related to bacteria owning high potential metabolic capacities were detected in both samples, such as Rhodobacter-like rRNA gene sequences. Surveys of cloned amoA genes from the two biofilm samples revealed ammonia-oxidizing bacterial sequences affiliated with the Nitrosomonas oligotropha lineage, Nitrosomonas communis lineage. An unknown Nitrosomonas group of amoA gene sequences was also detected.

Molecular analysis of microbial community in a groundwater sample polluted by landfill leachate and seawater.

Seashore landfill aquifers are environments of special physicochemical conditions (high organic load and high salinity), and microbes in leachate-polluted aquifers play a significant role for intrinsic bioremediation. In order to characterize microbial diversity and look for clues on the relationship between microbial community structure and hydrochemistry, a culture-independent examination of a typical groundwater sample obtained from a seashore landfill was conducted by sequence analysis of 16S rDNA clone library. Two sets of universal 16S rDNA primers were used to amplify DNA extracted from the groundwater so that problems arising from primer efficiency and specificity could be reduced. Of 74 clones randomly selected from the libraries, 30 contained unique sequences whose analysis showed that the majority of them belonged to bacteria (95.9%), with Proteobacteria (63.5%) being the dominant division. One archaeal sequence and one eukaryotic sequence were found as well. Bacterial sequences belonging to the following phylogenic groups were identified: Bacteroidetes (20.3%), beta, gamma, delta and epsilon-subdivisions of Proteobacteria (47.3%, 9.5%, 5.4% and 1.3%, respectively), Firmicutes (1.4%), Actinobacteria (2.7%), Cyanobacteria (2.7%). The percentages of Proteobacteria and Bacteroides in seawater were greater than those in the groundwater from a non-seashore landfill, indicating a possible influence of seawater. Quite a few sequences had close relatives in marine or hypersaline environments. Many sequences showed affiliations with microbes involved in anaerobic fermentation. The remarkable abundance of sequences related to (per)chlorate-reducing bacteria (ClRB) in the groundwater was significant and worthy of further study.

Variations of dominant microbial populations in groundwater in response to the leachate from Laogang Landfill.

Temporal changes of dominant microbial populations in groundwater in response to the leachate from Shanghai Laogang Landfill were investigated. Concentrations of dissolved redox-relevant species in groundwater suggested that the dominating redox process had changed from denitrification to methane-production/sulfate-reduction due to landfilling. Dominant microbial populations were determined using restriction fragment length polymorphism( RFLP) analyses of 16S rRNA gene libraries, which were further studied by sequencing and phylogenetic analyses. The results indicated that obvious shifts of dominant microbial populations had occurred in groundwater in response to the pollution of leachate. The closest relatives of some dominant clones are accordant with the dominating redox processes determined by hydrochemical analyses, based on the GenBank's indications on the ability to perform redox reactions.

Growth responses of Picea mongolica seedlings to defoliation rate.

Picea mongolica W. D. Xu. is an endemic species in China. The spruce forest is only found in semi-arid habitat in Inner Mongolia Autonomous Region of China. Based on the simulative defoliation experiment, it was proved that Picea mongolica seedlings had the compensatory and overcompensatory effects under the certain defoliation rate. The results of variance analysis on growth indexes showed that in PM I (natural regeneration seedlings under Picea mongolica forest), the differences of H1 (height in June 23) and H2 (height in September 3) were extremely significant, and the difference of D(diameter at the breast height) were not significant. In PM II (artificial regeneration seedlings under Betula platyphylla Suk. forest), the difference of H1 was significant, the difference of H2 was not significant, and the difference of D was extremely significant. The regression equations were established and the compensatory and overcompensatory points were obtained. In PM I, the compensatory points of H1, H2, and D were 0.7628, 0.7436, 0.5725, and the overcompensatory points were 0.6056, 0.5802 and 0.2909 respectively. In PM II, the compensatory points of H,, H2, and D are 0.5012, 0.3421, 0.2488, and the overcompensatory points are 0.4137, 0.2633 and 0.0747 respectively. These results suggested that the induction of compensatory growth mechanisms in spruce seedlings required a threshold level of defoliation, and the insects in Picea mongolica forest could be controlled in a certain degree.

Outcomes for jejunal interposition reconstruction compared with Roux-en-Y anastomosis: A meta-analysis.

AIM: To compare the clinical outcomes between jejunal interposition reconstruction and Roux-en-Y anastomosis after total gastrostomy in patients with gastric cancer. METHODS: A systematic literature search was conducted by two independent researchers on PubMed, EMBASE, the Cochrane Library, Google Scholar, and other English literature databases, as well as the Chinese Academic Journal, Chinese Biomedical Literature Database, and other Chinese literature databases using "Gastrostomy", "Roux-en-Y", and "Interposition" as keywords. Data extraction and verification were performed on the literature included in this study. RevMan 5.2 software was used for data processing. A fixed-effects model was applied in the absence of heterogeneity between studies. A random effects model was applied in the presence of heterogeneity between studies. RESULTS: Ten studies with a total of 762 gastric cancer patients who underwent total gastrostomy were included in this study. Among them, 357 received jejunal interposition reconstruction after total gastrostomy, and 405 received Roux-en-Y anastomosis. Compared with Roux-en-Y anastomosis, jejunal interposition reconstruction significantly decreased the incidence of dumping syndrome (OR = 0.18, 95%CI: 0.10-0.31; P < 0.001), increased the prognostic nutritional index [weighted mean difference (WMD) = 6.02, 95%CI: 1.82-10.22; P < 0.001], and improved the degree of postoperative weight loss [WMD = 2.47, 95%CI: -3.19-(-1.75); P < 0.001]. However, there is no statistically significant difference in operative time, hospital stay, or incidence of reflux esophagitis. CONCLUSION: Compared with Roux-en-Y anastomosis, patients who underwent jejunal interposition reconstruction after total gastrostomy had a lower risk of postoperative long-term complications and improved life quality.

[Bronchial and pulmonary arterial sleeve resection and reconstruction in the treatment of central NSCLC].

OBJECTIVE: To evaluate the indications and surgical procedure of bronchial and pulmonary artery sleeve resection for patients with centrally located non-small cell lung cancer, and how to prevent complications. METHODS: From July 1989 to Aug 2000, 32 cases of central NSCLC were treated with bronchial and pulmonary arterial sleeve resection and reconstruction. The results were retrospectively analyzed. RESULTS: The complication rate was 25.0% (8/32), the mortality rate in 30-day postoperation was 6.3% (2/32), the overall 1-, 3- and 5-year survival rate was 82.8% (24/29), 50.0% (11/22) and 33.3% (4/12), respectively. CONCLUSION: Bronchial and pulmonary arterial sleeve resection and reconstruction in the treatment of patients with central NSCLC can not only maximize preservation of functional pulmonary parenchyma and improve patients, quality of life, but also provide an opportunity for those patients with poor pulmonary function to receive surgical resection of the tumor.

Seasonal variation in communities of ammonia-oxidizing bacteria based on polymerase chain reaction - denaturing gradient gel electrophoresis in a biofilm reactor for drinking water pretreatment.

The diversity and variation of total and active ammonia-oxidizing bacteria in a full-scale aerated submerged biofilm reactor for drinking water pretreatment were characterized by clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA and its gene during a whole year. Sequences obtained from clone libraries affiliated with the Nitrosomonas oligotropha lineage and the Nitrosomonas communis lineage. An uncultured subgroup of Nitrosomonas communis lineage was also detected. Seasonal variations in both total and active ammonia-oxidizing bacteria communities were observed in the DGGE profiles, but an RNA-based analysis reflected more obvious dynamic changes in ammonia-oxidizer community than a DNA-based approach. Statistical study based on canonical correspondence analysis showed that a community shift of active ammonia oxidizers was significantly influenced by temperature and pH, but no significant correlation was found between environmental variables and total ammonia-oxidizer community shift.

Population dynamics of ammonia-oxidizing bacteria in an aerated submerged biofilm reactor for micropolluted raw water pretreatment.

Population dynamics of ammonia-oxidizing bacteria (AOB) in a full-scale aerated submerged biofilm reactor for micropolluted raw water pretreatment was investigated using molecular techniques for a period of 1 year. The ammonia monooxygenase (amoA) gene fragments were amplified from DNA and RNA extracts of biofilm samples. Denaturing gradient gel electrophoresis (DGGE) profile based on the amoA messenger RNA approach exhibited a more variable pattern of temporal dynamics of AOB communities than the DNA-derived approach during the study. Phylogenetic analysis of excised DGGE bands revealed three AOB groups affiliated with the Nitrosomonas oligotropha lineage, Nitrosomonas communis lineage, and an unknown Nitrosomonas group. The population size of betaproteobacterial AOB, quantified with 16S ribosomal RNA gene real-time polymerase chain reaction assay, ranged from 6.63 x 10(5) to 2.67 x 10(9) cells per gram of dry biofilm and corresponded to 0.23-1.8% of the total bacterial fraction. Quantitative results of amoA gene of the three specific AOB groups revealed changes in competitive dominance between AOB of the N. oligotropha lineage and N. communis lineage. Water temperature is shown to have major influence on AOB population size in the reactor by the statistic analysis, and a positive correlation between AOB cell numbers and ammonia removal efficiency is suggested (r = 0.628, P < 0.05).

[The effects of vascular endothelial growth factor on dendritic cells in esophageal tumor tissue].

AIM: To investigate the relationship between vascular endothelial growth factor (VEGF) and S100 protein positive dendritic cell (DC) in esophagelal tumor tissue. METHODS: VEGF and S100 protein in 94 patients with esophageal carcinoma were detected by HRP Labelled streptavidin biotin(LSAB) immunohistochemical method. RESULTS: Postive rate of VEGF in esophageal tumor tissues was 74.46%(70/94); and the later the clinical stage and the lower the differentiation level was the more VEGF was(r=0.864, 0.803, respectively; P<0.05); while the later the clinical stage and the lower the differentiation level was, the less number of S100(+) DCs existed (r=-0.763, -0.908, respectively; P<0.05). Furthermore, there was a reverse correlation between the expression of VEGF and S100(+) DC (r=-0.817, P<0.05). CONCLUSION: There may be a reverse relationship between the expression of VEGF and S100(+) DC in esophageal tumor tissue, VEGF could decrease the number of S100(+) DC and impair the immunological function of the body.

[Comparison of the characteristics in recurrence and metastasis between bronchioloalveolar carcinoma and other lung adenocarcinomas].

BACKGROUND & OBJECTIVE: The histological definition of bronchioloalveolar carcinoma (BAC) has been changed recently by the revised World Health Organization (WHO) classification. Although bronchioloalveolar carcinoma is a subtype of lung adenocarcinoma, its biological features are better than those of other lung adenocarcinomas. This study was to analyze differences in metastatic activity between bronchioloalveolar carcinoma and other lung adenocarcinomas. METHODS: The expression of E-Cadherin, Collagen IV, vascular endothelial growth factor receptor-2 (VEGFR-2), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in 28 specimens of stage I bronchioloalveolar carcinoma confirmed pathologically and 40 specimens of other stage I lung adenocarcinomas were detected by immunohistochemistry. Their correlations to tumor recurrence and metastasis were analyzed. RESULTS: The 5-year survival rate was significantly higher in ths patients with bronchioloalveolar carcinoma than in the patients with other lung adenocarcinomas (88.7% vs. 57.3%, P < 0.05). The intrathoracic recurrence rate was significantly higher and the extrathoracic metastasis rate was significantly lower in the patients with bronchioloalveolar carcinoma than in the patients with other lung adenocarcinomas (75% vs. 33.3%, 25% vs. 66.7%, P < 0.05). The positive rates of Collagen IV, E-Cadherin and TIMP-1 were significantly higher in bronchioloalveolar carcinoma than in other lung adenocarcinomas (78.6% vs. 42.5%, 78.6% vs. 40.0%, 67.5% vs. 42.9%, all P < 0.01). The positive rate of VEGFR-2 was significantly higher in other lung adenocarcinomas than in bronchioloalveolar carcinoma (85.7% vs. 77.5%, P < 0.05). There was no significant difference in the positive rate of MMP-9 between bronchioloalveolar carcinoma and other lung adenocarcinomas (85.0% vs. 78.6%, P = 0.494). CONCLUSION: As compared with other lung adenocarcinomas, stage I bronchioloalveolar carcinoma is less aggressive in clinical behavior and likely to develop intrathoracic recurrence, with less extrathoracic metastases and better prognosis.