6 research outputs found

    Preparation and mesomorphic properties of 1-methyl-<i>1H</i>-benzimidazole-based compounds

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    <p>A series of 1-methyl-<i>1H</i>-benzimidazole-based compounds, 2-(4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-1-methyl- <i>1H</i>-1,3-benzimidazole derivatives (nPPMx-M) with terminal hydrogen, methyl and nitro moieties (coded as nPPMH-M, nPPMM-M and nPPMN-M, respectively), were prepared and their structures were characterised. The compounds display enantiotropic smectic mesophases for hydrogen and methyl terminated compounds (nPPMH-M and nPPMM-M), and enantiotropic nematic mesophases for nitro terminated compounds (nPPMN-M) with short alkoxy chain below than 10 carbon atoms, where the mesophase ranges are 24–72°C and 74–104°C on heating and cooling processes for nPPMH-M, 90–119°C and 110–135°C for nPPMM-M, and 102–129°C and 113–207°C for nPPMN-M, respectively. It is noted that the compounds nPPMx-M exhibit much lower melting points and much wider mesophase range both in heating and cooling than non-1-methyl substituted analogs, which are ascribed to the disruption of hydrogen bonding among the molecules caused by methyl substitution at 1-position of benzimidazole. Meanwhile, among the compounds nPPMx-M, much wider mesophase ranges are obtained for nPPMM-M and nPPMN-M, indicating a much high mesophase stability for the compounds bearing terminal moiety (CH<sub>3</sub> and NO<sub>2</sub>).</p

    NOD2 genetic variants and sarcoidosis-associated uveitis

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    Purpose: Identifying genetic risk factors for developing sarcoidosis-associated uveitis could provide insights into its pathogenesis which is poorly understood. We determine if variants in NOD2 confer an increased risk of developing uveitis in adults with sarcoidosis. Methods: In this genetic case-control study, 51 total subjects were enrolled: 39 patients diagnosed with sarcoid-related uveitis and 12 patients with systemic sarcoidosis without ocular involvement as controls. Sanger sequencing of the eleven exons of the NOD2 gene was performed on DNA obtained from whole blood. Sanger sequencing data were aligned against the NOD2 NCBI-RefSeq reference sequence to identify novel mutations in uveitis patients. For common variants, allele frequencies in cases versus controls were compared using the chi-square test. Results: There were no significant differences in NOD2 common variant allele frequencies between sarcoidosis patients with and without uveitis, and none of the pathogenic NOD2 mutations associated with Blau syndrome were found in this cohort. However, four rare, non-synonymous variants were identified in four patients with ocular sarcoidosis and none of the controls. Variants rs149071116, rs35285618, and 16:g.50745164T > C have never been previously reported to be associated with any disease and may be pathogenic. The fourth variant, rs2066845, is associated with Crohn’s disease and psoriatic arthritis. Conclusions: Despite the phenotypic overlap between sarcoidosis and Blau syndrome, none of the established pathogenic NOD2 variants were present in adults with sarcoidosis. However, four novel, rare, non-synonymous variants were identified in four cases with ocular sarcoidosis. Further investigation is needed to explore the potential clinical significance of these polymorphisms
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