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131.
132.
Background
Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning.Methodology/Principal Findings
Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA), was investigated with respect to (i) microbial habitat type and (ii) coral species and color, as well as the three spatial components (iii) geomorphologic reef zoning, (iv) reef boundary, and (v) reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus) and ambient microbial habitats (seawater, sediments). This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity.Conclusions/Significance
This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has fundamental implications for the monitoring of microbial diversity and function in those ecosystems. 相似文献133.
Panagiotis Bargiotas Antje Krenz Hannah Monyer Markus Schwaninger 《Channels (Austin, Tex.)》2012,6(6):453-456
Pannexin (Px, Panx) channels have been implicated in several physiological and pathological processes. We recently studied the potential contribution of pannexins in ischemic brain damage using Px1-/- Px2-/- mice and provided evidence that (1) the release of IL-1β and hemichannel function in astrocytes are, in contrast to published data, not affected by the absence of Px1 and Px2, (2) channel function in neurons lacking Px1 and Px2 is impaired and (3) Px1-/- Px2-/- mice had a better functional outcome and smaller infarcts than wild-type mice when subjected to ischemic stroke. Here, we further investigate the neurological outcome of wild-type and pannexin double-knockout mice 48 h after permanent occlusion of the distal middle cerebral artery (MCAO). Pannexin double-knockout mice (Px1-/- Px2-/-) were less impaired in parameters such as exploration, anxiety, sensorimotor function and behavioral symmetry. 相似文献
134.
Biorecognition-element labeled liposomes are simple and versatile tools used to amplify signals for the detection of analytes of environmental, clinical, food safety, and national security interest. Relying on measurement of encapsulated species via electrochemical or spectroscopic techniques, or properties inherent to liposomes themselves (such as mass, refractive index, or charge), many advances have been made in both bench-scale and microfluidic applications. Some of these measurement techniques are inherently sensitivity limited, but through the inclusion of liposomes, reduced limits of detection potentially broaden the utility towards otherwise challenging levels of analytes. Other advances took advantage of the hydrophobic environment required by many biorecognition elements to expand the target selectivity range or utilized the amphipathic nature of the lipid bilayer to provide enhanced separation capabilities. Novel handling approaches included wavelength-specific release of contents encapsulated within thermosensitive liposomes or application of electric fields to move, concentrate, and strategically lyse liposomes. These and other topics are discussed in terms of either present incorporation or adaptation to microfluidic devices. 相似文献
135.
136.
H Gross C Hennard I Masouris C Cassel S Barth U Stober-Grässer A Mamiani B Moritz D Ostareck A Ostareck-Lederer N Neuenkirchen U Fischer W Deng H Leonhardt E Noessner E Kremmer FA Grässer 《PloS one》2012,7(8):e42106
The Epstein-Barr Virus (EBV) -encoded EBNA2 protein, which is essential for the in vitro transformation of B-lymphocytes, interferes with cellular processes by binding to proteins via conserved sequence motifs. Its Arginine-Glycine (RG) repeat element contains either symmetrically or asymmetrically di-methylated arginine residues (SDMA and ADMA, respectively). EBNA2 binds via its SDMA-modified RG-repeat to the survival motor neurons protein (SMN) and via the ADMA-RG-repeat to the NP9 protein of the human endogenous retrovirus K (HERV-K (HML-2) Type 1). The hypothesis of this work was that the methylated RG-repeat mimics an epitope shared with cellular proteins that is used for interaction with target structures. With monoclonal antibodies against the modified RG-repeat, we indeed identified cellular homologues that apparently have the same surface structure as methylated EBNA2. With the SDMA-specific antibodies, we precipitated the Sm protein D3 (SmD3) which, like EBNA2, binds via its SDMA-modified RG-repeat to SMN. With the ADMA-specific antibodies, we precipitated the heterogeneous ribonucleoprotein K (hnRNP K). Specific binding of the ADMA- antibody to hnRNP K was demonstrated using E. coli expressed/ADMA-methylated hnRNP K. In addition, we show that EBNA2 and hnRNP K form a complex in EBV- infected B-cells. Finally, hnRNP K, when co-expressed with EBNA2, strongly enhances viral latent membrane protein 2A (LMP2A) expression by an unknown mechanism as we did not detect a direct association of hnRNP K with DNA-bound EBNA2 in gel shift experiments. Our data support the notion that the methylated surface of EBNA2 mimics the surface structure of cellular proteins to interfere with or co-opt their functional properties. 相似文献
137.
CW Ip A Kroner J Groh M Huber D Klein I Spahn R Diem SK Williams KA Nave JM Edgar R Martini 《PloS one》2012,7(8):e42554
Mice overexpressing proteolipid protein (PLP) develop a leukodystrophy-like disease involving cytotoxic, CD8+ T-lymphocytes. Here we show that these cytotoxic T-lymphocytes perturb retrograde axonal transport. Using fluorogold stereotactically injected into the colliculus superior, we found that PLP overexpression in oligodendrocytes led to significantly reduced retrograde axonal transport in retina ganglion cell axons. We also observed an accumulation of mitochondria in the juxtaparanodal axonal swellings, indicative for a disturbed axonal transport. PLP overexpression in the absence of T-lymphocytes rescued retrograde axonal transport defects and abolished axonal swellings. Bone marrow transfer from wildtype mice, but not from perforin- or granzyme B-deficient mutants, into lymphocyte-deficient PLP mutant mice led again to impaired axonal transport and the formation of axonal swellings, which are predominantly located at the juxtaparanodal region. This demonstrates that the adaptive immune system, including cytotoxic T-lymphocytes which release perforin and granzyme B, are necessary to perturb axonal integrity in the PLP-transgenic disease model. Based on our observations, so far not attended molecular and cellular players belonging to the immune system should be considered to understand pathogenesis in inherited myelin disorders with progressive axonal damage. 相似文献
138.
Ann-Kathrin Oehme Asia N. Rashed Barbara Hefele Ian C. K. Wong Wolfgang Rascher Antje Neubert 《PloS one》2012,7(9)
Background
In recent years, efforts have been made to improve paediatric drug therapy. The aim of this research was to investigate any changes regarding the frequency and nature of adverse drug reactions (ADRs) in hospitalized children in one paediatric general medical ward over a 9-year period.Methodology
Two prospective observational cohort studies were conducted at a large University hospital in Germany in 1999 and 2008, respectively. Children aged 0–18 years admitted to the study ward during the study periods were included. ADRs were identified using intensive chart review. Uni- and multivariable regression has been used for data analysis.Results
A total of 520 patients (574 admissions) were included [1999: n = 144 (167); 2008: n = 376 (407)]. Patients received a total of 2053 drugs [median 3, interquartile range (IQR) 2–5]. 19% of patients did not receive any medication. Median length of stay was 4 days (IQR 3–7; range 1–190 days) with a significantly longer length of stay in 1999. The overall ADR incidence was 13.1% (95% CI, 9.8–16.3) varying significantly between the two study cohorts [1999: 21.9%, 95% CI, 14.7–29.0; 2008: 9.2%, 95% CI, 5.9–12.5 (p<0.001)]. Antibacterials and corticosteroids for systemic use caused most of the ADRs in both cohorts (1999; 2008). Exposure to systemic antibacterials decreased from 62.9% to 43.5% whereas exposure to analgesics and anti-inflammatory drugs increased from 17.4% to 45.2%, respectively. The use of high risk drugs decreased from 75% to 62.2%. In 1999, 45.7% and in 2008 96.2% of ADRs were identified by treating clinicians (p<0.001).Conclusions
Between 1999 and 2008, the incidence of ADRs decreased significantly. Improved treatment strategies and an increased awareness of ADRs by physicians are most likely to be the cause for this positive development. Nevertheless further research on ADRs particularly in primary care and the establishment of prospective pharmacovigilance systems are still needed. 相似文献139.
Wegener G Bausch M Holler T Thang NM Prieto Mollar X Kellermann MY Hinrichs KU Boetius A 《Environmental microbiology》2012,14(6):1517-1527
Sub‐seafloor sediments are populated by large numbers of microbial cells but not much is known about their metabolic activities, growth rates and carbon assimilation pathways. Here we introduce a new method enabling the sensitive detection of microbial lipid production and the distinction of auto‐ and heterotrophic carbon assimilation. Application of this approach to anoxic sediments from a Swedish fjord allowed to compare the activity of different functional groups, the growth and turnover times of the bacterial and archaeal communities. The assay involves dual stable isotope probing (SIP) with deuterated water (D2O) and 13CDIC (d issolved i norganic c arbon). Culture experiments confirmed that the D content in newly synthesized lipids is in equilibrium with the D content in labelled water, independent of whether the culture grew hetero‐ or autotrophically. The ratio of 13CDIC to D2O incorporation enables distinction between these two carbon pathways in studies of microbial cultures and in environmental communities. Furthermore, D2O‐SIP is sufficiently sensitive to detect the formation of few hundred cells per day in a gram of sediment. In anoxic sediments from a Swedish fjord, we found that > 99% of newly formed lipids were attributed to predominantly heterotrophic bacteria. The production rate of bacterial lipids was highest in the top 5 cm and decreased 60‐fold below this depth while the production rate of archaeal lipids was rather low throughout the top meter of seabed. The contrasting patterns in the rates of archaeal and bacterial lipid formation indicate that the factors controlling the presence of these two lipid groups must differ fundamentally. 相似文献
140.
James P Higham Michael Heistermann Carina Saggau Muhammad Agil Dyah Perwitasari-Farajallah Antje Engelhardt 《BMC evolutionary biology》2012,12(1):1-10