2,209 research outputs found

    Detection of lymphangiogenesis in non-small cell lung cancer and its prognostic value

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    <p>Abstract</p> <p>Background</p> <p>Our aim was to detect lymphatic endothelial marker podoplanin, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and vascular endothelial growth factor receptor-3 (VEGFR)-3 and study the prognostic relevance of lymphangiogenesis in non-small cell lung cancer (NSCLC).</p> <p>Materials</p> <p>82 paraffin-embedded tissues and 40 fresh frozen tissues from patients with NSCLC were studied. Tumor samples were immunostained for the lymphatic endothelial markers. Lymphangiogenesis was assessed by immunohistochemical double stains for Podoplanin and Ki-67. The prognostic relevance of lymphangiogenesis-related clinicopathological parameters in NSCLC was evaluated.</p> <p>Results</p> <p>We found that the number of podoplanin positive vessels was correlated positively with the number of LYVE-1 positive vessels. Most of VEGFR-3 positive, few of LYVE-1 positive and none of podoplanin positive vessels were blood vessels. Peritumoral lymphatic vessel density (ptLVD), pathologic stage, lymph node status, lymphatic vessel invasion (LVI), vascular endothelial growth factor-C (VEGF-C) expression and Ki-67 index of the endothelium cells of the micro lymphatic vessels (Ki67%) were associated significantly with a higher risk of tumor progress. ptLVD, pathologic stage, lymph-node metastasis and Ki67% were independent prognostic parameters for overall survival.</p> <p>Conclusion</p> <p>Podoplanin positive ptLVD might play important roles in the lymphangiogenesis and progression of NSCLC. Patients with high podoplanin+ ptLVD have a poor prognosis.</p

    Computational Understanding of the Selectivities in Metalloenzymes

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    Metalloenzymes catalyze many different types of biological reactions with high efficiency and remarkable selectivity. The quantum chemical cluster approach and the combined quantum mechanics/molecular mechanics methods have proven very successful in the elucidation of the reaction mechanism and rationalization of selectivities in enzymes. In this review, recent progress in the computational understanding of various selectivities including chemoselectivity, regioselectivity, and stereoselectivity, in metalloenzymes, is discussed

    HCV genotype 6 prevalence, spontaneous clearance and diversity amongst elderly members of the Li ethnic minority in Baisha County, China

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    The epidemiology of hepatitis C virus varies widely across geographical regions and ethnic groups. Our previous study showed that 6 strains isolated from Baisha County, Hainan Island, China, were all new genotype 6 (gt6) subtypes which differed significantly from subtypes of other regions. In the current study, we conducted a comprehensive epidemiological survey of HCV in the Li ethnic group, native to Baisha County. Anti‐HCV antibodies were detected by 2 independent ELISAs in all participants, and positive results confirmed by the recombinant immunoblot assay (RIBA) and HCV RNA viral loads were measured. Univariate chi‐square test and multivariable logistic regression analyses were used to determine the risk factors for HCV infection and spontaneous clearance rates. Indeterminate RIBA results were excluded or included in analyses; consequently, findings were expressed as a range. Direct sequencing of partial regions within NS5B and E1 was employed for genotyping. Among 1682 participants, 117 to 153 were anti‐HCV positive (7.0%‐9.1%), with 42.7%‐52.6% confirmed to have cleared infection. Anti‐HCV positivity was associated with older age (≥60 years) (OR = 0.02, 95% CI 0.01‐0.05, P &lt; 0.01) and surgery (OR = 2.75, 95% CI 1.36‐5.57, P &lt; 0.01), with no significant difference found between the HCV infection group and the HCV spontaneous clearance group. The gt6 subtype distribution characteristics of Baisha County were unique, complex and diverse. The sequences did not cluster with known gt6 subtypes but formed 4 Baisha community‐specific groups. HCV infection in members of the Li minority ethnic group is characterized by high prevalence rates in the elderly, high spontaneous clearance rates and broad gt6 diversity

    Glycine Potentiates AMPA Receptor Function through Metabotropic Activation of GIuN2A-Containing NMDA Receptors

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    NMDA receptors are Ca2+.-permeable ion channels. The activation of NMDA receptors requires agonist glutamate and co-agonist glycine. Recent evidence indicates that NMDA receptor also has metabotropic function. Here we report that in cultured mouse hippocampal neurons, glycine increases AMPA receptor -mediated currents independent of the channel activity of NMDA receptors and the activation of glycine receptors. The potentiation of AMPA receptor function by glycine is antagonized by the inhibition of ERK1/2. In the hippocampal neurons and in the HEK293 cells transfected with different combinations of NMDA receptors, glycine preferentially acts on GIuN2A-containing NMDA receptors (GIuN2ARs), but not GIuN2B-containing NMDA receptors (GIuN2BRs), to enhance ERK1/2 phosphorylation independent of the channel activity of GIuN2ARs. Without requiring the channel activity of GIuN2ARs, glycine increases AMPA receptor -mediated currents through GIuN2ARs. Thus, these results reveal a metabotropic function of GIuN2ARs in mediating glycine-induced potentiation of AMPA receptor function via ERK1/2 activation

    Evolutional selection of a combinatorial phage library displaying randomly-rearranged various single domains of immunoglobulin (Ig)-binding proteins (IBPs) with four kinds of Ig molecules

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    <p>Abstract</p> <p>Background</p> <p>Protein A, protein G and protein L are three well-defined immunoglobulin (Ig)-binding proteins (IBPs), which show affinity for specific sites on Ig of mammalian hosts. Although the precise functions of these molecules are not fully understood, it is thought that they play an important role in pathogenicity of bacteria. The single domains of protein A, protein G and protein L were all demonstrated to have function to bind to Ig. Whether combinations of Ig-binding domains of various IBPs could exhibit useful novel binding is interesting.</p> <p>Results</p> <p>We used a combinatorial phage library which displayed randomly-rearranged various-peptide-linked molecules of D and A domains of protein A, designated PA(D) and PA(A) respectively, B2 domain of protein G (PG) and B3 domain of protein L (PL) for affinity selection with human IgG (hIgG), human IgM (hIgM), human IgA (hIgA) and recombinant hIgG1-Fc as bait respectively. Two kinds of novel combinatorial molecules with characteristic structure of PA(A)-PG and PA(A)-PL were obtained in hIgG (hIgG1-Fc) and hIgM (hIgA) post-selection populations respectively. In addition, the linking peptides among all PA(A)-PG and PA(A)-PL structures was strongly selected, and showed interestingly divergent and convergent distribution. The phage binding assays and competitive inhibition experiments demonstrated that PA(A)-PG and PA(A)-PL combinations possess comparable binding advantages with hIgG/hIgG1-Fc and hIgM/hIgA respectively.</p> <p>Conclusion</p> <p>In this work, a combinatorial phage library displaying Ig-binding domains of protein A, protein G, or protein L joined by various random linking peptides was used to conducted evolutional selection <it>in vitro</it> with four kinds of Ig molecules. Two kinds of novel combinations of Ig-binding domains, PA(A)-PG and PA(A)-PL, were obtained, and demonstrate the novel Ig binding properties.</p

    Microarray-based analysis of microRNA expression in breast cancer stem cells

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    <p>Abstract</p> <p>Background</p> <p>This study aimed to determine the miRNA profile in breast cancer stem cells (BCSCs) and to explore the functions of characteristic BCSC miRNAs.</p> <p>Methods</p> <p>We isolated ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>BCSCs from MCF-7 cells using fluorescence-activated cell sorting (FACS). A human breast cancer xenograft assay was performed to validate the stem cell properties of the isolated cells, and microarray analysis was performed to screen for BCSC-related miRNAs. These BCSC-related miRNAs were selected for bioinformatic analysis and target prediction using online software programs.</p> <p>Results</p> <p>The ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>cells had up to 100- to 1000-fold greater tumor-initiating capability than the MCF-7 cells. Tumors initiated from the ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>cells were included of luminal epithelial and myoepithelial cells, indicating stem cell properties. We also obtained miRNA profiles of ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>BCSCs. Most of the possible targets of potential tumorigenesis-related miRNAs were oncogenes, anti-oncogenes or regulatory genes.</p> <p>Conclusions</p> <p>We identified a subset of miRNAs that were differentially expressed in BCSCs, providing a starting point to explore the functions of these miRNAs. Evaluating characteristic BCSC miRNAs represents a new method for studying breast cancer-initiating cells and developing therapeutic strategies aimed at eradicating the tumorigenic subpopulation of cells in breast cancer.</p

    Optimization of a static headspace GC-MS method and its application in metabolic fingerprinting of the leaf volatiles of 42 citrus cultivars

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    Citrus leaves, which are a rich source of plant volatiles, have the beneficial attributes of rapid growth, large biomass, and availability throughout the year. Establishing the leaf volatile profiles of different citrus genotypes would make a valuable contribution to citrus species identification and chemotaxonomic studies. In this study, we developed an efficient and convenient static headspace (HS) sampling technique combined with gas chromatography-mass spectrometry (GC-MS) analysis and optimized the extraction conditions (a 15-min incubation at 100 ˚C without the addition of salt). Using a large set of 42 citrus cultivars, we validated the applicability of the optimized HS-GC-MS system in determining leaf volatile profiles. A total of 83 volatile metabolites, including monoterpene hydrocarbons, alcohols, sesquiterpene hydrocarbons, aldehydes, monoterpenoids, esters, and ketones were identified and quantified. Multivariate statistical analysis and hierarchical clustering revealed that mandarin (Citrus reticulata Blanco) and orange (Citrus sinensis L. Osbeck) groups exhibited notably differential volatile profiles, and that the mandarin group cultivars were characterized by the complex volatile profiles, thereby indicating the complex nature and diversity of these mandarin cultivars. We also identified those volatile compounds deemed to be the most useful in discriminating amongst citrus cultivars. This method developed in this study provides a rapid, simple, and reliable approach for the extraction and identification of citrus leaf volatile organic compound, and based on this methodology, we propose a leaf volatile profile-based classification model for citrus
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