Distinct patterns of distribution, community assembly and cross-domain co-occurrence of planktonic archaea in four major estuaries of China.

BACKGROUND: Archaea are key mediators of estuarine biogeochemical cycles, but comprehensive studies comparing archaeal communities among multiple estuaries with unified experimental protocols during the same sampling periods are scarce. Here, we investigated the distribution, community assembly, and cross-domain microbial co-occurrence of archaea in surface waters across four major estuaries (Yellow River, Yangtze River, Qiantang River, and Pearl River) of China cross climatic zones (~ 1,800 km) during the winter and summer cruises. RESULTS: The relative abundance of archaea in the prokaryotic community and archaeal community composition varied with estuaries, seasons, and stations (reflecting local environmental changes such as salinity). Archaeal communities in four estuaries were overall predominated by ammonia-oxidizing archaea (AOA) (aka. Marine Group (MG) I; primarily Nitrosopumilus), while the genus Poseidonia of Poseidoniales (aka. MGII) was occasionally predominant in Pearl River estuary. The cross-estuary dispersal of archaea was largely limited and the assembly mechanism of archaea varied with estuaries in the winter cruise, while selection governed archaeal assembly in all estuaries in the summer cruise. Although the majority of archaea taxa in microbial networks were peripherals and/or connectors, extensive and distinct cross-domain associations of archaea with bacteria were found across the estuaries, with AOA as the most crucial archaeal group. Furthermore, the expanded associations of MGII taxa with heterotrophic bacteria were observed, speculatively indicating the endogenous demand for co-processing high amount and diversity of organic matters in the estuarine ecosystem highly impacted by terrestrial/anthropogenic input, which is worthy of further study. CONCLUSIONS: Our results highlight the lack of common patterns in the dynamics of estuarine archaeal communities along the geographic gradient, expanding the understanding of roles of archaea in microbial networks of this highly dynamic ecosystem.

Comparative analysis of laparoscopic proximal gastrectomy plus semi-embedded valve anastomosis with laparoscopic total gastrectomy for adenocarcinoma of the esophagogastric junction: a single-center retrospective cohort study.

BACKGROUND: We invented a new antireflux anastomosis method for use in proximal gastrectomy for adenocarcinoma of the esophagogastric junction (AEG) and named it semi-embedded valve anastomosis (SEV). This study was conducted to compare and analyze the short-term efficacy and long-term prognosis of this anastomosis reconstruction method versus laparoscopic total gastrectomy (LTG). METHODS: We retrospectively analyzed the general data and surgical outcomes of patients with AEG who underwent three united laparoscopic proximal gastrectomy plus semi-embedded valve anastomosis (TULPG-SEV, N = 20) and LTG (N = 20) at our hospital from January 2015 to September 2017 and investigated the incidence of postoperative reflux esophagitis and postoperative nutritional status between the two groups. Survival analysis was also performed. RESULTS: The operative time (178.25 ± 15.41 vs 196.5 ± 21.16 min) and the gastrointestinal reconstruction time (19.3 ± 2.53 vs 34.65 ± 4.88 min) of the TULPG-SEV group were significantly less than that of the LTG group. There was no difference in intraoperative blood loss, length of hospital stay, and postoperative complications. There was no difference in the scores on the postoperative reflux disease questionnaires (RDQs) conducted 1 month (P = 0.501), 3 months (P = 0.238), and 6 months (P = 0.655) after surgery between the TULPG-SEV group and LTG group. Gastroscopy revealed 2 cases of reflux esophagitis (grade B or higher) in each group. The postoperative hemoglobin level was better in the TULPG-SEV group than in the LTG group, and the difference was most noticeable at 1 month after surgery (P = 0.024) and 3 months after surgery (P = 0.029). The levels of albumin and total protein were not significantly different between the groups. There were more patients with weight loss over 5 kg after surgery in the LTG group than in the TULPG-SEV group (P = 0.043). There was no significant difference in the 3-year overall survival rate between the two groups (P = 0.356). CONCLUSION: SEV has a certain antireflux effect and can reduce the anastomosis time. Proximal gastrectomy may be better than total gastrectomy for maintaining postoperative hemoglobin levels and reducing weight loss.

The role of the Epstein-Barr virus-encoded BARF1 gene expressed in human gastric epithelial cells.

BACKGROUND/AIMS: The study aimed to explore the effects of Epstein-Barr virus--encoded BARF1 in human gastric epithelial cells (GES-1). MATERIALS AND METHODS: A eukaryotic expression vector carrying BARF1 gene (pcDNA3.1-BARF1) was constructed. The pcDNA3.1-BARF1 was transfected into GES-1 cells, and they were selected by G418. The GES-1 cells lines that expressed BARF1 (GES-1-BARF1) were obtained. The cycle of GES-1-pcDNA3.1 cells (GES-1 cells transfected with empty vector), GES-1-BARF1 cells (GES-1 cells transfected with BARF1), and TPA-GES-1-BARF1(GES-1-BARF1 cells stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA) were analyzed by flow cytometry. Colony formation in soft agar and tumorigenicity of the transfected cells in mice with severe combined immunodeficiency (SCID) were also observed. RESULTS: The morphology of GES-1-BARF1 cells were changed from the original shuttle to round, the adhesion between the cells and bottle wall was weakened, and the cells showed overlapping growth. The proliferation rate of GES-1-BARF1 and TPA-GES-1-BARF1 cells were faster than GES-1 and GES-1-pcDNA3.1 cells; the S phase was significantly prolonged for GES-1-BARF1 and TPA-GES-1-BARF1. GES-1-BARF1 and TPA-GES-1-BARF1 cells formed colonies in soft agar, with a cloning rate of 24.2% (58/240) and 40.0% (96/240), respectively; GES-1 and GES-1-pcDNA3.1 cells did not form colonies in soft agar. Tumors were formed in mice with SCID after injecting TPA-GES-1-BARF1 cell groups. Tumor formation did not occur in mice with SCID after injecting GES-1 and GES-1-pcDNA3.1 cell groups, but nodules were formed in the mice with SCID after injecting GES-1-BARF1 cell groups. CONCLUSION: GES-1-BARF1 cells malignant transformation was induced by transfected BARF1 gene and TPA stimulation. This result indicated that tumor formation not only require oncogenes, but also the stimulation of cancer-promoting substance.