Search results for " nuclei"
showing 10 items of 602 documents
Molecular basis of the primary and secondary radiation damage to DNA/RNA nucleobases
2017
La interacción radiación-materia ha sido una de las grandes preocupaciones científicas de los últimos tiempos, y es que es clave para entender la vida en la Tierra tal y como la conocemos. En este contexto, son de especial relevancia los procesos inducidos en sistemas celulares por radicación externa, en particular, aquellos localizados en los ácidos nucleicos, ya que éstos son los portadores de la información genética de todos los seres vivos. Sólo la comprensión de la competitividad entre procesos inocuos y lesivos inducidos por radiación llevará al entendimiento del sutil equilibrio entre integridad y cambio, salud y enfermedad, y en términos más globales, inmovilidad y evolución. La Tes…
Nitric oxide increases the decay of matrix metalloproteinase 9 mRNA by inhibiting the expression of mRNA-stabilizing factor HuR.
2003
Dysregulation of extracellular matrix turnover is an important feature of many inflammatory processes. Rat renal mesangial cells express high levels of matrix metalloproteinase 9 (MMP-9) in response to inflammatory cytokines such as interleukin-1 beta. We demonstrate that NO does strongly destabilize MMP-9 mRNA, since different luciferase reporter gene constructs containing the MMP-9 3' untranslated region (UTR) displayed significant reduced luciferase activity in response to the presence of NO. Moreover, by use of an in vitro degradation assay we found that the cytoplasmic fractions of NO-treated cells contained a higher capacity to degrade MMP-9 transcripts than those obtained from contro…
The untranslated region of exon 2 of the human neuronal nitric oxide synthase (NOS1) gene exerts regulatory activity.
2007
Expressional dysregulation of the human neuronal nitric oxide synthase (NOS1) gene represents an important mechanism in the pathogenesis of certain neuronal disease states. The structure and regulation of the human NOS1 gene is highly complex based on cell type- and stimulus-dependent usage of multiple exon 1 variants. Here we demonstrate that the untranslated region of exon 2 exerts promoter and enhancer functions as well, facilitated in large part by cooperative interaction of two conserved adjacent CREB/AP-1 binding sites. In human neuronal A673 cells, NOS1 expression is stimulated by several compounds which act through these sites, but also stimulate the combined promoter region of exon…
A sequence element downstream of the yeast HTB1 gene contributes to mRNA 3' processing and cell cycle regulation.
2002
Histone mRNAs accumulate in the S phase and are rapidly degraded as cells progress into the G(2) phase of the cell cycle. In Saccharomyces cerevisiae, fusion of the 3' untranslated region and downstream sequences of the yeast histone gene HTB1 to a neomycin phosphotransferase open reading frame is sufficient to confer cell cycle regulation on the resulting chimera gene (neo-HTB1). We have identified a sequence element, designated the distal downstream element (DDE), that influences both the 3'-end cleavage site selection and the cell cycle regulation of the neo-HTB1 mRNA. Mutations in the DDE, which is located approximately 110 nucleotides downstream of the HTB1 gene, lead to a delay in the…
DNASE1L3 deficiency, new phenotypes, and evidence for a transient type I IFN signaling.
2022
Background: Deoxyribonuclease 1 like 3 (DNASE1L3) is a secreted enzyme that has been shown to digest the extracellular chromatin derived from apoptotic bodies, and DNASE1L3 pathogenic variants have been associated with a lupus phenotype. It is unclear whether interferon signaling is sustained in DNASE1L3 deficiency in humans. Objectives: To explore interferon signaling in DNASE1L3 deficient patients. To depict the characteristic features of DNASE1L3 deficiencies in human. Methods: We identified, characterized, and analyzed five new patients carrying biallelic DNASE1L3 variations. Whole or targeted exome and/or Sanger sequencing was performed to detect pathogenic variations in five juvenile …
15. Functional mapping of monaural auditory brainstem responses
2012
Background and aims: The pedunculopontine nucleus (PPN) is a new deep brain stimulation (DBS) target, thought to be particularly for useful in ameliorating gait disturbance in Parkinson’s disease. Recent evidence shows a prominent theta (4–7 Hz) rhythm in the PPN (Tsang et al., Neurology, 2010; Simon et al., J. Neurophysiol., 2010; Shimamoto et al., JNNP, 2010). Given that theta activity is modulated by vestibular signals elsewhere in the brain, e.g. hippocampus, (Shin, Synapse, 2010; Chen et al., Neuroimage, 2010), we assessed whether vestibular signals modulate PPN theta activity. Methods: We recorded local field potentials (LFPs) in three patients with implanted bilateral subthalamic nuc…
P13. Dendato-thalamo-cortical pathways in association with otolith dysfunction
2015
Introduction The processing of otolith information within the human cortex is still poorly understood (Lopez and Blanke, 2011). Two distinct anatomical otolith pathways within the thalamo-cortical vestibular network were proposed in patients with thalamic infarctions who presented with contra- or ipsiversive tilts of the subjective visual vertical (SVV) (Dieterich and Brandt, 1993; Baier et al., submitted for publication). Aim of this study was to investigate the dendato-thalamo-cortical pathways in association with otolith dysfunction by means of DTI (diffusion tensor imaging) based on the regions found in a recent patient study using statistical lesion-behavior mapping (Baier et al., subm…
Functional brain imaging of peripheral and central vestibular disorders.
2008
This review summarizes our current knowledge of multisensory vestibular structures and their functions in humans. Most of it derives from brain activation studies with PET and fMRI conducted over the last decade. The patterns of activations and deactivations during caloric and galvanic vestibular stimulations in healthy subjects have been compared with those in patients with acute and chronic peripheral and central vestibular disorders. Major findings are the following: (1) In patients with vestibular neuritis the central vestibular system exhibits a spontaneous visual-vestibular activation–deactivation pattern similar to that described in healthy volunteers during unilateral vestibular sti…
The topographic diagnosis of acquired nystagmus in brainstem disorders.
2002
Evidence is presented for a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex (VOR): yaw, pitch, and roll. The plane-specific vestibular syndromes are determined by ocular motor, postural, and perceptual signs. Yaw plane signs are horizontal nystagmus, horizontal past pointing, rotational and lateral body falls to the right or to the left, and horizontal deviation of perceived straight-ahead. Pitch plane signs are upbeat/downbeat nystagmus, forward/backward tilts and falls, and upward or downward deviations of the perceived horizontal. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, …
Vertigo, Masseter Paresis or Masseter Reflex Abnormality, and Impaired Caloric Response
1993
Symptoms and signs of acute peripheral-type vestibular abnormalities occasionally occur in patients with multiple sclerosis and brain-stem ischemia. Such patients may show reduced excitability of the lateral semicircular canal. From this observation, the question arises as to the location of the causative lesion.