Unique prokaryotic consortia in geochemically distinct sediments from Red Sea Atlantis II and Discovery Deep brine pools

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS ONE 7 (2012): e42872, doi:10.1371/journal.pone.0042872.The seafloor is a unique environment, which allows insights into how geochemical processes affect the diversity of biological life. Among its diverse ecosystems are deep-sea brine pools - water bodies characterized by a unique combination of extreme conditions. The ‘polyextremophiles’ that constitute the microbial assemblage of these deep hot brines have not been comprehensively studied. We report a comparative taxonomic analysis of the prokaryotic communities of the sediments directly below the Red Sea brine pools, namely, Atlantis II, Discovery, Chain Deep, and an adjacent brine-influenced site. Analyses of sediment samples and high-throughput pyrosequencing of PCR-amplified environmental 16S ribosomal RNA genes (16S rDNA) revealed that one sulfur (S)-rich Atlantis II and one nitrogen (N)-rich Discovery Deep section contained distinct microbial populations that differed from those found in the other sediment samples examined. Proteobacteria, Actinobacteria, Cyanobacteria, Deferribacteres, and Euryarchaeota were the most abundant bacterial and archaeal phyla in both the S- and N-rich sections. Relative abundance-based hierarchical clustering of the 16S rDNA pyrotags assigned to major taxonomic groups allowed us to categorize the archaeal and bacterial communities into three major and distinct groups; group I was unique to the S-rich Atlantis II section (ATII-1), group II was characteristic for the N-rich Discovery sample (DD-1), and group III reflected the composition of the remaining sediments. Many of the groups detected in the S-rich Atlantis II section are likely to play a dominant role in the cycling of methane and sulfur due to their phylogenetic affiliations with bacteria and archaea involved in anaerobic methane oxidation and sulfate reduction.This work was supported by King Abdullah University for Science and Technology Global Collaborative Partners (GCR) program

Core Microbial Functional Activities in Ocean Environments Revealed by Global Metagenomic Profiling Analyses

Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world's oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs) of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light.This work was supported by King Abdullah University for Science and Technology Global Collaborative Partners (GCR) program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Expression of correctly processed human growth hormone in seeds of transgenic tobacco plants

Human growth hormone was expressed in transgenic tobacco seeds using the monocot tissue-specific promoter from sorghum gamma-kafirin seed storage protein gene. During tobacco seed ripening, the expressed hormone was directed to the endoplasmic reticulum by a signal peptide from a Coix prolamin and was secreted into the apoplastic space, where it accounted for 0.16% of total soluble seed protein. The expressed hormone has the same amino acid sequence and receptor-binding properties as the native mature hormone.61475

Efficacy of loco-regional treatment for hepatocellular carcinoma prior to living donor liver transplantation: a report from a single center in Egypt

Mohammad Kamal Shaker,1 Iman F Montasser,1 Mohamed Sakr,1 Mohamed Elgharib,2 Hany M Dabbous,1 Hend Ebada,1 Ahmed El Dorry,2 Mohamed Bahaa,3 Mahmoud El Meteini3 1Department of Tropical Medicine, 2Department of Radiodiagnosis and Interventional Radiology, 3Department of Hepatobiliary Surgery and Liver Transplantation, Ain Shams Center for Organ Transplantation (ASCOT), Ain Shams University, Cairo, Egypt Background and aim: The number of loco-regional therapies (LRTs) for hepatocellular carcinoma (HCC) has increased dramatically during the past decade, bridging or downstaging patients on the waiting list for liver transplantation. This study aimed to analyze the outcomes of LRTs prior to living donor liver transplantation in patients with HCC. Methods: Sixty-two HCC patients received living donor liver transplantation at Ain Shams Center for Organ Transplantation over a 2-year period. Data from 29 HCC patients were analyzed. Twenty patients (68.97%) met the Milan Criteria and 4 patients (13.8%) exceeded the Milan Criteria, but met the University of California, San Francisco Criteria. Five patients (17.2%) exceeded the University of California, San Francisco Criteria. All patients underwent preoperative LRTs. The protocol of bridging/downstaging, methods, duration of follow-up, the number of patients who were successfully downstaged before liver transplantation (LT), and their outcomes after LT were recorded.Results: There was a decrease in the mean overall size of focal lesions (from mean 5.46 to 4.11 cm) in the last abdominal computed tomography (CT) scan after LRT (p=0.0018). Discrepancies between the radiological findings and histopathology were as follows: in 16 patients (55.17%) the CT findings were consistent with the histopathological examination of the explanted liver. Underestimated tumor stage was documented in 10 patients (34.48%), and was overestimated by CT scan findings in 3 patients (10.34%). The 1-year survival rate was 93%. No patient had HCC recurrence after median follow-up of 21 months (range 1–46 months).Conclusion: These results encouraged tumor bridging/downstaging as a potential treatment option among carefully selected patients with HCC beyond conventional criteria for LT. Further studies on a large number of patients are necessary. Keywords: hepatocellular carcinoma, loco-regional therapy, LRT , liver transplantation, Milan criteria, beyond Milan, HCC recurrence, bridge/down stagin