591 research outputs found

    Combined Striatum, Brain Stem, and Optic Nerve Involvement due to Mycoplasma pneumoniae in an Ambulatory Child

    Get PDF
    In children, Mycoplasma pneumoniae encephalitis has been characterized by acute onset of an encephalopathy associated with extrapyramidal symptoms and symmetric basal ganglia with or without brain stem involvement on magnetic resonance imaging. Our case, showing unilateral optic neuritis, ophthalmoplegia, no extrapyramidal symptoms, and typical striatal involvement on magnetic resonance imaging, broadens the spectrum of varying clinical manifestations of childhood M. pneumoniae-associated encephalopathy

    Association between polymorphisms of arachidonate 12-lipoxygenase (ALOX12) and schizophrenia in a Korean population

    Get PDF
    Arachidonic acid (AA), an essential polyunsaturated fatty acid, is one of the major components of neural membranes, which show an altered phospholipid composition in schizophrenia. Arachidonate 12-lipoxygenase (ALOX12), an important enzyme, metabolizes AA to 12-HPETE, which affects catecholamine synthesis. However, research has yet to show the genetic association between ALOX12 and schizophrenia. Therefore, we investigated single nucleotide polymorphisms (SNP) of the ALOX12 gene in schizophrenia, recruiting patients with schizophrenia (n = 289) and normal controls (n = 306) from a Korean population. We selected three SNPs (rs1126667, rs434473, and rs1042357) of the ALOX12 gene and genotyped them by direct sequencing. We reviewed the schizophrenic patients' medical records and assessed them clinically using the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), and the Operational Criteria Checklist (OPCRIT). Then we statistically analyzed the genetic associations between the SNPs and schizophrenia, finding a genetic association between both rs1126667 and rs1042357 and schizophrenia, in the recessive model (p = 0.015 and 0.015, respectively). We also found an association between rs434473 and negative symptoms, defined through a factor analysis of the OPCRIT data (p = 0.040). Consequently, we suggest that SNPs of the ALOX12 gene might be associated with schizophrenia and negative symptoms in this Korean population. These weak positives require additional study

    Two distinct red giant branch populations in the globular cluster NGC 2419 as tracers of a merger event in the Milky Way

    Full text link
    Recent spectroscopic observations of the outer halo globular cluster (GC) NGC 2419 show that it is unique among GCs, in terms of chemical abundance patterns, and some suggest that it was originated in the nucleus of a dwarf galaxy. Here we show, from the Subaru narrow-band photometry employing a calcium filter, that the red giant-branch (RGB) of this GC is split into two distinct subpopulations. Comparison with spectroscopy has confirmed that the redder RGB stars in the hkhk[=(Ca−b)−(b−y)-b)-(b-y)] index are enhanced in [Ca/H] by ∼\sim0.2 dex compared to the bluer RGB stars. Our population model further indicates that the calcium-rich second generation stars are also enhanced in helium abundance by a large amount (Δ\DeltaY = 0.19). Our photometry, together with the results for other massive GCs (e.g., ω\omega Cen, M22, and NGC 1851), suggests that the discrete distribution of RGB stars in the hkhk index might be a universal characteristic of this growing group of peculiar GCs. The planned narrow-band calcium photometry for the Local Group dwarf galaxies would help to establish an empirical connection between these GCs and the primordial building blocks in the hierarchical merging paradigm of galaxy formation.Comment: 4 pages, 4 figures, 1 table, accepted for the publication in ApJ

    Ammonium Inhibits Chromomethylase 3-Mediated Methylation of the Arabidopsis Nitrate Reductase Gene NIA2

    Get PDF
    Gene methylation is an important mechanism regulating gene expression and genome stability. Our previous work showed that methylation of the nitrate reductase (NR) gene NIA2 was dependent on chromomethylase 3 (CMT3). Here, we show that CMT3-mediated NIA2 methylation is regulated by ammonium in Arabidopsis thaliana. CHG sequences (where H can be A, T, or C) were methylated in NIA2 but not in NIA1, and ammonium [(NH4)2SO4] treatment completely blocked CHG methylation in NIA2. By contrast, ammonium had no effect on CMT3 methylation, indicating that ammonium negatively regulates CMT3-mediated NIA2 methylation without affecting CMT3 methylation. Ammonium upregulated NIA2 mRNA expression, which was consistent with the repression of NIA2 methylation by ammonium. Ammonium treatment also reduced the overall genome methylation level of wild-type Arabidopsis. Moreover, CMT3 bound to specific promoter and intragenic regions of NIA2. These combined results indicate that ammonium inhibits CMT3-mediated methylation of NIA2 and that of other target genes, and CMT3 selectively binds to target DNA sequences for methylation
    • …
    corecore