164 research outputs found
Coupled variability in primary sensory areas and the hippocampus during spontaneous activity
The cerebral cortex is an anatomically divided and functionally specialized structure. It includes distinct areas, which work on different states over time. The structural features of spiking activity in sensory cortices have been characterized during spontaneous and evoked activity. However, the coordination among cortical and sub-cortical neurons during spontaneous activity across different states remains poorly characterized. We addressed this issue by studying the temporal coupling of spiking variability recorded from primary sensory cortices and hippocampus of anesthetized or freely behaving rats. During spontaneous activity, spiking variability was highly correlated across primary cortical sensory areas at both small and large spatial scales, whereas the cortico-hippocampal correlation was modest. This general pattern of spiking variability was observed under urethane anesthesia, as well as during waking, slow-wave sleep and rapid-eye-movement sleep, and was unchanged by novel stimulation. These results support the notion that primary sensory areas are strongly coupled during spontaneous activity.project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). NAPV was supported by Centro Universitario do Rio Grande do Norte, Champalimaud Foundation, and Brazilian National Council for Scientific and Technological Development (CNPq, Grant 249991/2013-6), CC-S (SFRH/BD/51992/2012). AJR (IF/00883/2013). SR by UFRN, CNPq (Research Productivity Grant 308775/2015-5), and S. Paulo Research Foundation FAPESP - Center for Neuromathematics (Grant 2013/07699-0)info:eu-repo/semantics/publishedVersio
Genome analysis and physiological comparison of Alicycliphilus denitrificans strains BC and K601T
The genomes of the Betaproteobacteria Alicycliphilus denitrificans strains BC and K601T have been sequenced to get insight into the physiology of the two strains. Strain BC degrades benzene with chlorate as electron acceptor. The cyclohexanol-degrading denitrifying strain K601T is not able to use chlorate as electron acceptor, while strain BC cannot degrade cyclohexanol. The 16S rRNA sequences of strains BC and K601T are identical and the fatty acid methyl ester patterns of the strains are similar. Basic Local Alignment Search Tool (BLAST) analysis of predicted open reading frames of both strains showed most hits with Acidovorax sp. JS42, a bacterium that degrades nitro-aromatics. The genomes include strain-specific plasmids (pAlide201 in strain K601T and pAlide01 and pAlide02 in strain BC). Key genes of chlorate reduction in strain BC were located on a 120 kb megaplasmid (pAlide01), which was absent in strain K601T. Genes involved in cyclohexanol degradation were only found in strain K601T. Benzene and toluene are degraded via oxygenase-mediated pathways in both strains. Genes involved in the meta-cleavage pathway of catechol are present in the genomes of both strains. Strain BC also contains all genes of the ortho-cleavage pathway. The large number of mono- and dioxygenase genes in the genomes suggests that the two strains have a broader substrate range than known thus far.This research was supported by the Technology Foundation, the Applied Science Division (STW) of the Netherlands Organization for Scientific Research (NWO), project number 08053, the graduate school WIMEK (Wageningen Institute for Environment and Climate Research, which is part of SENSE Research School for Socio-Economic and Natural Sciences of the Environment, www.wimek-new.wur.nl and www.sense.nl), SKB (Dutch Centre for Soil Quality Management and Knowledge Transfer, www.skbodem.nl) and the Consolider project CSD-2007-00055. The research was incorporated in the TRIAS (TRIpartite Approaches 469 toward Soil systems processes) program (http://www.nwo.nl/en/research-and-results/programmes/alw/trias-tripartite-approach-to-soil-system-processes/index. html). Flávia Talarico Saia was supported by a FAPESP (the State of São Paulo Research Foundation) scholarship (2006-01997/5). The work conducted by the DOE JGI is supported by the Office of Science of the United States Department of Energy under contract number DE-AC02-05CH11231. Alfons Stams acknowledges support by an ERC (European Research Counsil) advanced grant (project 323009). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
The ongoing pursuit of neuroprotective therapies in Parkinson disease
Many agents developed for neuroprotective treatment of Parkinson disease (PD) have shown great promise in the laboratory, but none have translated to positive results in patients with PD. Potential neuroprotective drugs, such as ubiquinone, creatine and PYM50028, have failed to show any clinical benefits in recent high-profile clinical trials. This 'failure to translate' is likely to be related primarily to our incomplete understanding of the pathogenic mechanisms underlying PD, and excessive reliance on data from toxin-based animal models to judge which agents should be selected for clinical trials. Restricted resources inevitably mean that difficult compromises must be made in terms of trial design, and reliable estimation of efficacy is further hampered by the absence of validated biomarkers of disease progression. Drug development in PD dementia has been mostly unsuccessful; however, emerging biochemical, genetic and pathological evidence suggests a link between tau and amyloid-β deposition and cognitive decline in PD, potentially opening up new possibilities for therapeutic intervention. This Review discusses the most important 'druggable' disease mechanisms in PD, as well as the most-promising drugs that are being evaluated for their potential efficiency in treatment of motor and cognitive impairments in PD
A "Candidate-Interactome" Aggregate Analysis of Genome-Wide Association Data in Multiple Sclerosis
Though difficult, the study of gene-environment interactions in multifactorial diseases is crucial for interpreting the relevance of non-heritable factors and prevents from overlooking genetic associations with small but measurable effects. We propose a “candidate interactome” (i.e. a group of genes whose products are known to physically interact with environmental factors that may be relevant for disease pathogenesis) analysis of genome-wide association data in multiple sclerosis. We looked for statistical enrichment of associations among interactomes that, at the current state of knowledge, may be representative of gene-environment interactions of potential, uncertain or unlikely relevance for multiple sclerosis pathogenesis: Epstein-Barr virus, human immunodeficiency virus, hepatitis B virus, hepatitis C virus, cytomegalovirus, HHV8-Kaposi sarcoma, H1N1-influenza, JC virus, human innate immunity interactome for type I interferon, autoimmune regulator, vitamin D receptor, aryl hydrocarbon receptor and a panel of proteins targeted by 70 innate immune-modulating viral open reading frames from 30 viral species. Interactomes were either obtained from the literature or were manually curated. The P values of all single nucleotide polymorphism mapping to a given interactome were obtained from the last genome-wide association study of the International Multiple Sclerosis Genetics Consortium & the Wellcome Trust Case Control Consortium, 2. The interaction between genotype and Epstein Barr virus emerges as relevant for multiple sclerosis etiology. However, in line with recent data on the coexistence of common and unique strategies used by viruses to perturb the human molecular system, also other viruses have a similar potential, though probably less relevant in epidemiological terms
Gastrointestinal failure in intensive care: a retrospective clinical study in three different intensive care units in Germany and Estonia
BACKGROUND: While gastrointestinal problems are common in ICU patients with multiple organ failure, gastrointestinal failure has not been given the consideration other organ systems receive. The aim of this study was to evaluate the incidence of gastrointestinal failure (GIF), to identify its risk factors, and to determine its association with ICU mortality. METHODS: A retrospective analysis of adult patients (n = 2588) admitted to three different ICUs (two ICUs at the university hospital Charité-Universitätsmedizin Berlin, Germany and one at Tartu University Clinics, Estonia) during the year 2002 was performed. Data recorded in a computerized database were used in Berlin. In Tartu, the data documented in the patients' charts was retrospectively transferred into a similar database. GIF was defined as documented gastrointestinal problems (food intolerance, gastrointestinal haemorrhage, and/or ileus) in the patient data at any period of their ICU stay. ICU mortality, length of stay, and duration of mechanical ventilation were assessed as outcome parameters. RESULTS: GIF was identified in 252 patients (9.7% of all patients). Only 20% of GIF patients were identifiable at admission. GIF was related to significantly higher mortality (43.7% vs. 5.3% in patients without GIF), as well as prolonged length of ICU stay (10 vs. 2 days) and mechanical ventilation (8 vs. 1 day), p < 0.001, respectively. Patients' profile (emergency surgical or medical), APACHE II and SOFA scores and the use of catecholamines at admission were identified as independent risk factors for the development of GIF. Development of GIF during ICU stay was an independent predictor for death. CONCLUSION: Gastrointestinal failure represents a relevant clinical problem accompanied by an increased mortality, longer ICU stay and mechanical ventilation
Mining Virulence Genes Using Metagenomics
When a bacterial genome is compared to the metagenome of an environment it inhabits, most genes recruit at high sequence identity. In free-living bacteria (for instance marine bacteria compared against the ocean metagenome) certain genomic regions are totally absent in recruitment plots, representing therefore genes unique to individual bacterial isolates. We show that these Metagenomic Islands (MIs) are also visible in bacteria living in human hosts when their genomes are compared to sequences from the human microbiome, despite the compartmentalized structure of human-related environments such as the gut. From an applied point of view, MIs of human pathogens (e.g. those identified in enterohaemorragic Escherichia coli against the gut metagenome or in pathogenic Neisseria meningitidis against the oral metagenome) include virulence genes that appear to be absent in related strains or species present in the microbiome of healthy individuals. We propose that this strategy (i.e. recruitment analysis of pathogenic bacteria against the metagenome of healthy subjects) can be used to detect pathogenicity regions in species where the genes involved in virulence are poorly characterized. Using this approach, we detect well-known pathogenicity islands and identify new potential virulence genes in several human pathogens
Genetic variability of histamine receptors in patients with Parkinson's disease
<p>Abstract</p> <p>Background</p> <p>Changes in the density and expression of histamine receptors (HRH) have been detected in Parkinson's disease (PD) patients, and HRH antagonists bring about improvements in motor and other symptoms, thus suggesting that HRH play a role in the clinical response of PD patients. This study is aimed to analyse polymorphic variations of HRH in patients with PD.</p> <p>Methods</p> <p>Leukocytary DNA from 195 PD patients and a control group of 231 unrelated healthy individuals was studied for the nonsynonymous HRH1Leu449Ser and the promoter HRH2G-1018A polymorphisms by using amplification-restriction analyses.</p> <p>Results</p> <p>The HRH1Leu449Ser amino acid substitution was identified in two women with late-onset PD whereas it was not observed among healthy subjects. The HRH2G-1018A polymorphism was observed with allele frequencies = 3.59 (95% CI = 1.74–5.44) and 5.0 (95% CI = 3.00–6.96) for patients with PD and healthy controls, respectively. These frequencies were independent of gender and age of onset of the disease. Multiple comparison analyses revealed that differences were not statistically significant.</p> <p>Conclusion</p> <p>These results indicate that the polymorphisms analyzed are not a major risk factor for PD, although the HRH1Leu449Ser amino acid substitution might be related to PD.</p
Plasma cytokines IL-6, IL-8, and IL-10 are associated with the development of acute respiratory distress syndrome in patients with severe traumatic brain injury
Routine human papillomavirus genotyping by DNA sequencing in community hospital laboratories
<p>Abstract</p> <p>Background</p> <p>Human papillomavirus (HPV) genotyping is important for following up patients with persistent HPV infection and for evaluation of prevention strategy for the individual patients to be immunized with type-specific HPV vaccines. The aim of this study was to optimize a robust "low-temperature" (LoTemp™) PCR system to streamline the research protocols for HPV DNA nested PCR-amplification followed by genotyping with direct DNA sequencing. The protocol optimization facilitates transferring this molecular technology into clinical laboratory practice. In particular, lowering the temperature by 10°C at each step of thermocycling during <it>in vitro </it>DNA amplification yields more homogeneous PCR products. With this protocol, template purification before enzymatic cycle primer extensions is no longer necessary.</p> <p>Results</p> <p>The HPV genomic DNA extracted from liquid-based alcohol-preserved cervicovaginal cells was first amplified by the consensus MY09/MY11 primer pair followed by nested PCR with GP5+/GP6+ primers. The 150 bp nested PCR products were subjected to direct DNA sequencing. The hypervariable 34–50 bp DNA sequence downstream of the GP5+ primer site was compared to the known HPV DNA sequences stored in the GenBank using on-line BLAST for genotyping. The LoTemp™ ready-to-use PCR polymerase reagents proved to be stable at room temperature for at least 6 weeks. Nested PCR detected 107 isolates of HPV in 513 cervicovaginal clinical samples, all validated by DNA sequencing. HPV-16 was the most prevalent genotype constituting 29 of 107 positive cases (27.2%), followed by HPV-56 (8.5%). For comparison, Digene HC2 test detected 62.6% of the 107 HPV isolates and returned 11 (37.9%) of the 29 HPV-16 positive cases as "positive for high-risk HPV".</p> <p>Conclusion</p> <p>The LoTemp™ ready-to-use PCR polymerase system which allows thermocycling at 85°C for denaturing, 40°C for annealing and 65°C for primer extension can be adapted for target HPV DNA amplification by nested PCR and for preparation of clinical materials for genotyping by direct DNA sequencing. HPV genotyping is performed by on-line BLAST algorithm of a hypervariable L1 region. The DNA sequence is included in each report to the physician for comparison in following up patients with persistent HPV infection, a recognized tumor promoter in cancer induction.</p
Edwardsiella Comparative Phylogenomics Reveal the New Intra/Inter-Species Taxonomic Relationships, Virulence Evolution and Niche Adaptation Mechanisms
Edwardsiella bacteria are leading fish pathogens causing huge losses to aquaculture industries worldwide. E. tarda is a broad-host range pathogen that infects more than 20 species of fish and other animals including humans while E. ictaluri is host-adapted to channel catfish causing enteric septicemia of catfish (ESC). Thus, these two species consist of a useful comparative system for studying the intricacies of pathogen evolution. Here we present for the first time the phylogenomic comparisons of 8 genomes of E. tarda and E. ictaluri isolates. Genome-based phylogenetic analysis revealed that E. tarda could be separate into two kinds of genotypes (genotype I, EdwGI and genotype II, EdwGII) based on the sequence similarity. E. tarda strains of EdwGI were clustered together with the E. ictaluri lineage and showed low sequence conservation to E. tarda strains of EdwGII. Multilocus sequence analysis (MLSA) of 48 distinct Edwardsiella strains also supports the new taxonomic relationship of the lineages. We identified the type III and VI secretion systems (T3SS and T6SS) as well as iron scavenging related genes that fulfilled the criteria of a key evolutionary factor likely facilitating the virulence evolution and adaptation to a broad range of hosts in EdwGI E. tarda. The surface structure-related genes may underlie the adaptive evolution of E. ictaluri in the host specification processes. Virulence and competition assays of the null mutants of the representative genes experimentally confirmed their contributive roles in the evolution/niche adaptive processes. We also reconstructed the hypothetical evolutionary pathway to highlight the virulence evolution and niche adaptation mechanisms of Edwardsiella. This study may facilitate the development of diagnostics, vaccines, and therapeutics for this under-studied pathogen
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