Comprehensive characterization of the patient-derived xenograft and the paralleled primary hepatocellular carcinoma cell line

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Water Oxidation Catalysed by Iron Complex of N,N′-dimethyl-2,11-diaza[3,3](2,6)pyridinophane. Spectroscopy of Iron–oxo Intermediates and Density Functional Theory Calculations

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Epigenetic regulation of the electrophysiological phenotype of human embryonic stem cell-derived ventricular cardiomyocytes: Insights for driven maturation and hypertrophic growth

Epigenetic regulation is implicated in embryonic development and the control of gene expression in a cell-specific manner. However, little is known about the role of histone methylation changes on human cardiac differentiation and maturation. Using human embryonic stem cells (hESCs) and their derived ventricular (V) cardiomyocytes (CMs) as a model, we examined trimethylation of histone H3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3) on promoters of genes associated with cardiac electrophysiology, contraction, and Ca2+ handling. To avoid ambiguities due to heterogeneous chamber-specific types, hESC-derived ventricular cardiomyocytes (VCMs) were selected by dual zeocin-GFP expression under the transcriptional control of the MLC2v promoter and confirmed electrophysiologically by its signature action potential phenotype. High levels of H3K4me3 are present on pluripotency genes in hESCs with an absence of H3K27me3. Human ESC-VCMS, relative to hESCs, were characterized by a profound loss of H3K27me3 and an enrichment of H3K4me3 marks on cardiac-specific genes, including MYH6, MYH7, MYL2, cTNT, and ANF. Gene transcripts encoding key voltage-gated ion channels and Ca2+-handling proteins in hESC-VCMs were significantly increased, which could be attributed to a distinct pattern of differential H3K4me3 and H3K27me3 profiles. Treatment of hESC-VCMs with the histone deacetylase inhibitor valproic acid increased H3K4me3 on gene promoters, induced hypertrophic growth (as gauged by cell volume and capacitance), and augmented cardiac gene expression, but it did not affect electrophysiological properties of these cells. Hence, cardiac differentiation of hESCs involves a dynamic shift in histone methylation, which differentially affects VCM gene expression and function. We conclude that the epigenetic state of hESC-VCMs is dynamic and primed to promote growth and developmental maturation, but that proper environmental stimuli with chromatin remodeling will be required to synergistically trigger global CM maturation to a more adult-like phenotype. © Mary Ann Liebert, Inc.published_or_final_versio

Establishment and characterization of a novel primary hepatocellular carcinoma cell line with metastatic ability in vivo

BACKGROUND: Hepatocellular carcinoma (HCC) is a highly aggressive and heterogeneous disease. HCC cell lines established from different patients would be useful in elucidating the molecular pathogenesis. However, success of HCC primary culture establishment remains at low rate. We aim to establish and characterize HCC primary culture and the derived cell line. METHODS: Fresh tumor tissues were collected from 30 HCC patients. Culture conditions were optimized for the attachment and growth of the isolated hepatocytes. Granulin-epithelin precursor (GEP), a growth factor reported to associate with cancer stem cell properties, was examined by flow cytometry to elucidate its role on primary culture establishment. The primary cell line was characterized in detail. RESULTS: Cells isolated from 16 out of 30 HCC cases (53%) had viability more than 70% and were subject to subsequent in vitro culture. 7 out of 16 cases (44%) could give rise to cells that were able to attach and grow in culture. GEP expression levels significantly correlated with the viability of isolated hepatocytes and success rate of subsequent primary culture establishment. Cells from HCC patient 21 grew and expanded rapidly in vitro and was selected to be further characterized. The line, designated HCC21, derived from a Hong Kong Chinese female patient with HCC at Stage II. The cells exhibited typical epithelial morphology and expressed albumin, AFP and HBV antigens. The cell line was authenticated by short tandem repeat analysis. Comparative genome hybridization analysis revealed chromosomal loss at 1p35-p36, 1q44, 2q11.2-q24.3, 2q37, 4q12-q13.3, 4q21.21-q35.2, 8p12-p23, 15q11.2-q14, 15q24-q26, 16p12.1-p13.3, 16q, 17p, 22q and gain at 1q21-q43 in both HCC21 cells and the original clinical tumor specimen. Sequence analysis revealed p53 gene mutation. Subcutaneous injection of HCC21 cells into immunodeficient mice showed that the cells were able to form tumors at the primary injection sites and metastatic tumors in the peritoneal cavity. CONCLUSIONS: The newly established cell line could serve as useful in vitro and in vivo models for studying primary HCC that possess metastasis ability.published_or_final_versio

Metabolomic profiling of Burkholderia pseudomallei using UHPLC-ESI-Q-TOF-MS reveals specific biomarkers including 4-methyl-5-thiazoleethanol and unique thiamine degradation pathway

© 2015 Lau et al.Background: Burkholderia pseudomallei is an emerging pathogen that causes melioidosis, a serious and potentially fatal disease which requires prolonged antibiotics to prevent relapse. However, diagnosis of melioidosis can be difficult, especially in culture-negative cases. While metabolomics represents an uprising tool for studying infectious diseases, there were no reports on its applications to B. pseudomallei. To search for potential specific biomarkers, we compared the metabolomics profiles of culture supernatants of B. pseudomallei (15 strains), B. thailandensis (3 strains), B. cepacia complex (14 strains), P. aeruginosa (4 strains) and E. coli (3 strains), using ultra-high performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry (UHPLC-ESI-Q-TOF-MS). Multi- and univariate analyses were used to identify specific metabolites in B. pseudomallei. Results: Principal component and partial-least squares discrimination analysis readily distinguished the metabolomes between B. pseudomallei and other bacterial species. Using multi-variate and univariate analysis, eight metabolites with significantly higher levels in B. pseudomallei were identified. Three of the eight metabolites were identified by MS/MS, while five metabolites were unidentified against database matching, suggesting that they may be potentially novel compounds. One metabolite, m/z 144.048, was identified as 4-methyl-5-thiazoleethanol, a degradation product of thiamine (vitamin B1), with molecular formula C6H9NOS by database searches and confirmed by MS/MS using commercially available authentic chemical standard. Two metabolites, m/z 512.282 and m/z 542.2921, were identified as tetrapeptides, Ile-His-Lys-Asp with molecular formula C22H37N7O7 and Pro-Arg-Arg-Asn with molecular formula C21H39N11O6, respectively. To investigate the high levels of 4-methyl-5-thiazoleethanol in B. pseudomallei, we compared the thiamine degradation pathways encoded in genomes of B. pseudomallei and B. thailandensis. While both B. pseudomallei and B. thailandensis possess thiaminase I which catalyzes degradation of thiamine to 4-methyl-5-thiazoleethanol, thiM, which encodes hydroxyethylthiazole kinase responsible for degradation of 4-methyl-5-thiazoleethanol, is present and expressed in B. thailandensis as detected by PCR/RT-PCR, but absent or not expressed in all B. pseudomallei strains. This suggests that the high 4-methyl-5-thiazoleethanol level in B. pseudomallei is likely due to the absence of hydroxyethylthiazole kinase and hence reduced downstream degradation. Conclusion: Eight novel biomarkers, including 4-methyl-5-thiazoleethanol and two tetrapeptides, were identified in the culture supernatant of B. pseudomallei.published_or_final_versio

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry for rapid identification of mold and yeast cultures of Penicillium marneffei

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Ricci Flow Gravity

A theory of gravitation is proposed, modeled after the notion of a Ricci flow. In addition to the metric an independent volume enters as a fundamental geometric structure. Einstein gravity is included as a limiting case. Despite being a scalar-tensor theory the coupling to matter is different from Jordan-Brans-Dicke gravity. In particular there is no adjustable coupling constant. For the solar system the effects of Ricci flow gravity cannot be distinguished from Einstein gravity and therefore it passes all classical tests. However for cosmology significant deviations from standard Einstein cosmology will appear.Comment: 15 pages. V2: improved presentation, in particular Jordan vs. Brans-Dicke and on viability. Added section on physical interpretation. V3: more references. Reworked to agree with published versio

Elizabethkingia anophelis bacteremia is associated with clinically significant infections and high mortality

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Harvesting convalescent plasma for hyperimmune intravenous globulin production: a multicentre randomised double-blind controlled trial for treatment of patients with serious S-OIV H1N1 infection

Poster Presentations: Emerging / Infectious Diseases: abstract no. P107-Ab0089Symposium Theme: Translating Health Research into Policy and Practice for Health of the Populationpublished_or_final_versio