604 research outputs found

    Biofilm development in time on a silicone voice prosthesis:A case study

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    Voice prostheses from silicone elastomers become rapidly colonised by a mixed biofilm of bacteria and yeasts. In this study, microorganisms were isolated from biofilms on explanted prostheses after having been in place for various time intervals ranging from 1 to 67 d. The isolates were examined for their identity, adhesion to hexadecane and electrophoretic mobility. Bacteria from early (shorter than 8 d) and late (longer than 8 d) explants could not be classified according to their taxonomy, hydrophobicity or electrophoretic mobility. However, the yeasts clearly revealed a dominance of only hydrophilic Candida albicans isolates from early explants and only hydrophobic C. tropicalis isolates from late explants. These findings may be of significance for the development of strategies to control mixed biofilms on biomaterials.</p

    A comparative study on the mineralogy, chemical speciation, and combustion behavior of toxic elements of coal beneficiation products

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    The huge demand for high-quality coal in China has resulted in increased generation of preparation plant wastes of various properties. A series of beneficiation products collected from a preparation plant were characterized to understand their petrographic and mineralogical characteristics, as well as thermochemical and trace element behavior during combustion. The minerals in the Luling preparation plant wastes from Huaibei coalfield mainly included kaolinite and quartz, with minor calcite, ankerite, pyrite, illite, chalcopyrite, albite, K-feldspar, anatase/rutile, and iron-oxide minerals. Massive clay lumps of terrigenous origin, cleat-infilling carbonate, and pyrite of epigenetic origin were prone to be enriched in the middlings and coal gangue. Minor or trace heavy minerals also reported to the preparation plant wastes. The contents of low-density density vitrinite and liptinite were enhanced in the clean coal, while inertinite-maceral group were enriched in the middlings. The modes of occurrences of toxic elements differed between raw coal and the waste products; and their transformation behavior during heavy medium separation is largely controlled by clay minerals (V, Cr, Co, Sb, and Pb), carbonate minerals (Co and Pb), sulfide minerals (As, Cu, Ni, Cd, and Zn) and organic matters (V, Cr, Se, and Cu). Three groups were classified based on the volatile ratio (Vr) of toxic elements. Group 1 includes the highly volatile element Se with Vr &gt; 85%; Group 2 contained elements As, Pb, Zn, Cd and Sb, with the Vr in the range of 20&ndash;85% and V, Cr, Co, Ni and Cu with Vr less than 20% were placed into Group 3. Thermal reactivity of coal inferred from the combustion profiles could be significantly improved after coal beneficiation, whereas the increased inorganic components probably inhibited the thermal chemical reaction of wastes.<br style="line-height: normal; text-align: -webkit-auto; text-size-adjust: auto;" /

    Gene expression changes induced by the tumorigenic pyrrolizidine alkaloid riddelliine in liver of Big Blue rats

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    <p>Abstract</p> <p>Background</p> <p>Pyrrolizidine alkaloids (PAs) are probably the most common plant constituents that poison livestock, wildlife, and humans worldwide. Riddelliine is isolated from plants grown in the western United States and is a prototype of genotoxic PAs. Riddelliine was used to investigate the genotoxic effects of PAs via analysis of gene expression in the target tissue of rats in this study. Previously we observed that the mutant frequency in the liver of rats gavaged with riddelliine was 3-fold higher than that in the control group. Molecular analysis of the mutants indicated that there was a statistically significant difference between the mutational spectra from riddelliine-treated and control rats.</p> <p>Results</p> <p>Riddelliine-induced gene expression profiles in livers of Big Blue transgenic rats were determined. The female rats were gavaged with riddelliine at a dose of 1 mg/kg body weight 5 days a week for 12 weeks. Rat whole genome microarray was used to perform genome-wide gene expression studies. When a cutoff value of a two-fold change and a <it>P</it>-value less than 0.01 were used as gene selection criteria, 919 genes were identified as differentially expressed in riddelliine-treated rats compared to the control animals. By analysis with the Ingenuity Pathway Analysis Network, we found that these significantly changed genes were mainly involved in cancer, cell death, tissue development, cellular movement, tissue morphology, cell-to-cell signaling and interaction, and cellular growth and proliferation. We further analyzed the genes involved in metabolism, injury of endothelial cells, liver abnormalities, and cancer development in detail.</p> <p>Conclusion</p> <p>The alterations in gene expression were directly related to the pathological outcomes reported previously. These results provided further insight into the mechanisms involved in toxicity and carcinogenesis after exposure to riddelliine, and permitted us to investigate the interaction of gene products inside the signaling networks.</p

    Solution structure of a repeated unit of the ABA-1 nematode polyprotein allergen of ascaris reveals a novel fold and two discrete lipid-binding sites

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    Parasitic nematode worms cause serious health problems in humans and other animals. They can induce allergic-type immune responses, which can be harmful but may at the same time protect against the infections. Allergens are proteins that trigger allergic reactions and these parasites produce a type that is confined to nematodes, the nematode polyprotein allergens (NPAs). These are synthesized as large precursor proteins comprising repeating units of similar amino acid sequence that are subsequently cleaved into multiple copies of the allergen protein. NPAs bind small lipids such as fatty acids and retinol (Vitamin A) and probably transport these sensitive and insoluble compounds between the tissues of the worms. Nematodes cannot synthesize these lipids, so NPAs may also be crucial for extracting nutrients from their hosts. They may also be involved in altering immune responses by controlling the lipids by which the immune and inflammatory cells communicate. We describe the molecular structure of one unit of an NPA, the well-known ABA-1 allergen of Ascaris and find its structure to be of a type not previously found for lipid-binding proteins, and we describe the unusual sites where lipids bind within this structur

    Sex-specific regulation of chemokine Cxcl5/6 controls neutrophil recruitment and tissue injury in acute inflammatory states

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    This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Barts and The London Trustees Studentship (SM), Marie Curie fellowships (MB, JD), Arthritis Research UK career development fellowship (JW), William Harvey Research Foundation grant (JW/RSS), Kidney Research UK fellowship (NSAP), Barts and The London Vacation Scholarship (ISN), Wellcome Trust senior fellowship (DWG), and a Wellcome Trust career development fellowship (RSS). This work forms part of the research themes contributing to the translational research portfolio of Barts and The London Cardiovascular Biomedical Research Unit, which is supported and funded by National Institute for Health Researc

    Neutrophils in cancer: neutral no more

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    Neutrophils are indispensable antagonists of microbial infection and facilitators of wound healing. In the cancer setting, a newfound appreciation for neutrophils has come into view. The traditionally held belief that neutrophils are inert bystanders is being challenged by the recent literature. Emerging evidence indicates that tumours manipulate neutrophils, sometimes early in their differentiation process, to create diverse phenotypic and functional polarization states able to alter tumour behaviour. In this Review, we discuss the involvement of neutrophils in cancer initiation and progression, and their potential as clinical biomarkers and therapeutic targets

    Ambulatory blood pressure monitoring and renal functions in children with a solitary kidney

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    The aim of this study is to investigate the blood pressure (BP) profile, microalbuminuria, renal functions, and relations with remaining normal kidney size in children with unilateral functioning solitary kidney (UFSK). Sixty-six children with UFSK were equally divided into three groups: unilateral renal agenesis (URA), unilateral atrophic kidney (UAK), and unilateral nephrectomy (UNP). Twenty-two age-, weight-, and height-matched healthy children were considered as a control group. The serum creatinine level and first-morning urine microalbumin and creatinine concentrations were determined by the standard methods. Also, the BP profile was determined by ambulatory blood pressure monitoring (ABPM). We found that the serum creatinine level was higher and creatinine clearance was lower in each patient groups compared to those of the control group (p < 0.05). Compared with the controls, each group of patients had mean office, 24-h, daytime, and night-time systolic and diastolic BP values similar to those of the controls (p > 0.05). An inverse correlation was found between the renal size standard deviation scores (SDS) of normal kidneys and 24-h systolic and diastolic BP load SDS in all of the patients (p < 0.05; r = −0.372, r = −0.295, respectively). The observed relationship between renal size SDS and 24-h mean arterial pressure (MAP), systolic and diastolic BP load SDS suggests that children with UFSK should be evaluated by using ABPM for the risk of hypertension

    A FRUITFULL-like gene is associated with genetic variation for fruit flesh firmness in apple (Malus domestica Borkh.)

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    The FRUITFULL (FUL) and SHATTERPROOF (SHP) genes are involved in regulating fruit development and dehiscence in Arabidopsis. We tested the hypothesis that this class of genes are also involved in regulating the development of fleshy fruits, by exploring genetic and phenotypic variation within the apple (Malus domestica) gene pool. We isolated and characterised the genomic sequences of two candidate orthologous FUL-like genes, MdMADS2.1 and MdMADS2.2. These were mapped using the reference population ‘Prima x Fiesta’ to loci on Malus linkage groups LG14 and LG06, respectively. An additional MADS-box gene, MdMADS14, shares high amino acid identity with the Arabidopsis SHATTERPROOF1/2 genes and was mapped to Malus linkage group LG09. Association analysis between quantitative fruit flesh firmness estimates of ‘Prima x Fiesta’ progeny and the MdMADS2.1, MdMADS2.2 and MdMADS14 loci was carried out using a mixed model analysis of variance. This revealed a significant association (P < 0.01) between MdMADS2.1 and fruit flesh firmness. Further evidence for the association between MdMADS2.1 and fruit flesh firmness was obtained using a case–control population-based genetic association approach. For this, a polymorphic repeat, (AT)n, in the 3′ UTR of MdMADS2.1 was used as a locus-specific marker to screen 168 apple accessions for which historical assessments of fruit texture attributes were available. This analysis revealed a significant association between the MdMADS2.1 and fruit flesh firmness at both allelic (χ 2 = 34, df = 9, P < 0.001) and genotypic (χ 2 = 57, df = 32, P < 0.01) levels
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