7,470 research outputs found

    Mapping the genetic architecture of gene expression in human liver

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    Genetic variants that are associated with common human diseases do not lead directly to disease, but instead act on intermediate, molecular phenotypes that in turn induce changes in higher-order disease traits. Therefore, identifying the molecular phenotypes that vary in response to changes in DNA and that also associate with changes in disease traits has the potential to provide the functional information required to not only identify and validate the susceptibility genes that are directly affected by changes in DNA, but also to understand the molecular networks in which such genes operate and how changes in these networks lead to changes in disease traits. Toward that end, we profiled more than 39,000 transcripts and we genotyped 782,476 unique single nucleotide polymorphisms (SNPs) in more than 400 human liver samples to characterize the genetic architecture of gene expression in the human liver, a metabolically active tissue that is important in a number of common human diseases, including obesity, diabetes, and atherosclerosis. This genome-wide association study of gene expression resulted in the detection of more than 6,000 associations between SNP genotypes and liver gene expression traits, where many of the corresponding genes identified have already been implicated in a number of human diseases. The utility of these data for elucidating the causes of common human diseases is demonstrated by integrating them with genotypic and expression data from other human and mouse populations. This provides much-needed functional support for the candidate susceptibility genes being identified at a growing number of genetic loci that have been identified as key drivers of disease from genome-wide association studies of disease. By using an integrative genomics approach, we highlight how the gene RPS26 and not ERBB3 is supported by our data as the most likely susceptibility gene for a novel type 1 diabetes locus recently identified in a large-scale, genome-wide association study. We also identify SORT1 and CELSR2 as candidate susceptibility genes for a locus recently associated with coronary artery disease and plasma low-density lipoprotein cholesterol levels in the process. © 2008 Schadt et al

    The early life microbiota protects neonatal mice from pathological small intestinal epithelial cell shedding

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    The early life gut microbiota plays a crucial role in regulating and maintaining the intestinal barrier, with disturbances in these communities linked to dysregulated renewal and replenishment of intestinal epithelial cells. Here we sought to determine pathological cell shedding outcomes throughout the postnatal developmental period, and which host and microbial factors mediate these responses. Surprisingly, neonatal mice (Day 14 and 21) were highly refractory to induction of cell shedding after intraperitoneal administration of liposaccharide (LPS), with Day 29 mice showing strong pathological responses, more similar to those observed in adult mice. These differential responses were not linked to defects in the cellular mechanisms and pathways known to regulate cell shedding responses. When we profiled microbiota and metabolites, we observed significant alterations. Neonatal mice had high relative abundances of Streptococcus, Escherichia, and Enterococcus and increased primary bile acids. In contrast, older mice were dominated by Candidatus Arthromitus, Alistipes, and Lachnoclostridium, and had increased concentrations of SCFAs and methyamines. Antibiotic treatment of neonates restored LPS-induced small intestinal cell shedding, whereas adult fecal microbiota transplant alone had no effect. Our findings further support the importance of the early life window for microbiota-epithelial interactions in the presence of inflammatory stimuli and highlights areas for further investigation

    Traditional Biocidal Replacement Viability of Microcrystalline Silver Chloride

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    The antimicrobial effects of silver ions and silver chloride nanoparticles have been well established while the efficacy of microcrystalline silver chloride has been less studied. Certex-AM, a microcrystalline silver chloride product produced by Cerion, Rochester, NY, was tested for its antimicrobial properties as a possible replacement for traditional biocidal techniques used in water cooling towers. The minimum inhibitory concentration (MIC) of the compound was determined using a microtiter broth assay. The compound was found to have inhibitory effects on bacterial growth for all tested organisms at concentrations greater than 9 ppm. Additional testing simulating a water cooling system showed the effectiveness of reducing an established wild population at concentrations of 10 ppm of the microcrystalline silver chloride. Certex-AM was found to be a promising replacement for traditional biocides as well as for other applications. Introduction of effective antimicrobial compounds such as this could reduce the pathogenic risk to humans associated with water cooling towers

    Enhanced selectivity of hydrogel-based molecularly imprinted polymers (HydroMIPs) following buffer conditioning.

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    We have investigated the effect of buffer solution composition and pH during the preparation, washing and re-loading phases within a family of acrylamide-based molecularly imprinted polymers (MIPs) for bovine haemoglobin (BHb), equine myoglobin (EMb) and bovine catalyse (BCat). We investigated water, phosphate buffer saline (PBS), tris(hydroxymethyl)aminomethane (Tris) buffer and succinate buffer. Throughout the study MIP selectivity was highest for acrylamide, followed by N-hydroxymethylacrylamide, and then N-iso-propylacrylamide MIPs. The selectivity of the MIPs when compared with the NIPs decreased depending on the buffer conditions and pH in the order of Tris>PBS>succinate. The Tris buffer provided optimum imprinting conditions at 50mM and pH 7.4, and MIP selectivities for the imprinting of BHb in polyacrylamide increased from an initial 8:1 to a 128:1 ratio. It was noted that the buffer conditions for the re-loading stage was important for determining MIP selectivity and the buffer conditions for the preparation stage was found to be less critical. We demonstrated that once MIPs are conditioned using Tris or PBS buffers (pH7.4) protein reloading in water should be avoided as negative effects on the MIP's imprinting capability results in low selectivities of 0.8:1. Furthermore, acidifying the pH of the buffer solution below pH 5.9 also has a negative impact on MIP selectivity especially for proteins with high isoelectric points. These buffer conditioning effects have also been successfully demonstrated in terms of MIP efficiency in real biological samples, namely plasma and serum

    Diagnosing social anxiety in Parkinson’s disease: Characteristics and frequencies according to two diagnostic criteria

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    BACKGROUND: Studies found inconsistent frequencies of social anxiety disorder (SAD) in Parkinson’s disease (PD) (9.7%-50%). Previous reports did not test the impact of applying DSM-IV restrictive criteria that recommends the exclusion of secondary cases when diagnosing SAD in PD. OBJECTIVE: Our aim is to estimate the frequency of social anxiety according to DSM-IV criteria and according to an inclusive broader approach. Methods: One hundred and ten PD patients were assessed for the presence of SAD using SCID-I, diagnosis of social anxiety were determined according to two different criteria: following and not following DSM-IV recommendation for exclusion of cases though to be secondary to a general medical condition. RESULTS: SAD was present in 34 (31%) of patients, but 17 (15.5%) were secondary to a general medical condition. Patients with SAD were significantly younger, had earlier disease onset, had more severe PD symptoms, and were more frequently depressed. There was no difference in demographic and clinical features between primary and secondary SAD. DISCUSSION: We conclude that the use of different diagnostic criteria may have a massive impact in the estimation of frequency of SAD in PD

    Isolation and characterization of a thermophilic, obligately anaerobic and heterotrophic marine Chloroflexi bacterium from a Chloroflexi dominated microbial community associated with a Japanese shallow hydrothermal system, and proposal for Thermomarinilinea lacunofontalis gen. nov., sp. nov.

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    A novel marine thermophilic and heterotrophic Anaerolineae bacterium in the phylum Chloroflexi, strain SW7T, was isolated from an in situ colonization system deployed in the main hydrothermal vent of the Taketomi submarine hot spring field located on the southern part of Yaeyama Archipelago, Japan. The microbial community associated with the hydrothermal vent was predominated by thermophilic heterotrophs such as Thermococcaceae and Anaerolineae, and the next dominant population was thermophilic sulfur oxidizers. Both aerobic and anaerobic hydrogenotrophs including methanogens were detected as minor populations. During the culture-dependent viable count analysis in this study, an Anaerolineae strain SW7T was isolated from an enrichment culture at a high dilution rate. Strain SW7T was an obligately anaerobic heterotroph grew with fermentation, and non-motile thin rods 3.5-16.5 μm in length and 0.2 μm in width constituting multicellular filament. Growth was observed between 37-65 ℃ (optimum 60℃), pH 5.5-7.3 (optimum pH 6.0), 0.5-3.5% (w/v) NaCl concentration (optimum 1.0%). Based on physiological and phylogenetic features of a new isolate, we propose a new species representing a novel genus Thermomarinilinea: the type strain of Thermomarinilinea lacunofontalis sp. nov., is SW7T (= JCM15506T = KCTC5908T)

    Determination of MecA Gene in Staphylococcus Spp., Isolate Subclinical Mastitis Ettawa Crossbred Goat Milk in Sleman Regency

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    . Antibiotic treatment is one of the recommended approaches to reduce intramammary infection. Currently, antibiotic resistance is problem in the livestock treatment, especially Methichilin resistance Staphylococcus aureus (MRSA). The mec A gene has a role in MRSA coding. Therefore, the aim of the present study was to determine the mecA gene in Staphylococcus spp., isolate subclinical mastitis Ettawa crosbreed goat's milk from Sleman Regency. A total of seven Stapylococcus spp., isolate subclinical mastitis Ettawa crosbreed goat be composed isolate S. aureus (1), S. epidermidis (1), S. hyicus (2) and S. intermedius (3) were used. Antibiotic susceptibility against Stapylococcus spp., isolate was determined by agar diffusion methode using the following antibiotic Cefoxitime and Oxacillin. The mecA gene was detected by polymerase chain reaction (PCR). The study showed that all isolate S. aureus, S. epidermidis, S. hyicus and S. intermedius resistance Cefoxitime, whereas Oxacillin resistance occured in two isolate S. intermedius and one isolate S. hyicus. The mecA gene only detected in one isolate S. hyicus, but none in the others isolate

    Determination of protein binding affinities within hydrogel-based molecularly imprinted polymers (HydroMIPs)

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    Hydrogel-based molecularly imprinted polymers (HydroMIPs) were prepared for several proteins (haemoglobin, myoglobin and catalase) using a family of acrylamide-based monomers. Protein affinity towards the HydroMIPs was investigated under equilibrium conditions and over a range of concentrations using specific binding with Hill slope saturation profiles. We report HydroMIP binding affinities, in terms of equilibrium dissociation constants (Kd) within the micro-molar range (25 ± 4 mM, 44 ± 3 mM, 17 ± 2 mM for haemoglobin, myoglobin and catalase respectively within a polyacrylamide-based MIP). The extent of non-specific binding or cross-selectivity for non-target proteins has also been assessed. It is concluded that both selectivity and affinity for both cognate and non-cognate proteins towards the MIPs were dependent on the concentration and the complementarity of their structures and size. This is tentatively attributed to the formation of protein complexes during both the polymerisation and rebinding stages at high protein concentrations. We have used atomic force spectroscopy to characterize molecular interactions in the MIP cavities using protein-modified AFM tips. Attractive and repulsive force curves were obtained for the MIP and NIP (non-imprinted polymer) surfaces (under protein loaded or unloaded states). Our force data suggest that we have produced selective cavities for the template protein in the MIPs and we have been able to quantify the extent of non-specific protein binding on, for example, a non-imprinted polymer (NIP) control surface
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