52 research outputs found
Étude prospective secondaire visant à préciser l’influence de la température de conservation des urines sur le profil électrophorétique des protéines urinaires sur gel d’agarose chez le chien protéinurique.
No full textUne étude sur les variations préanalytiques des électrophorèses des protéines urinaires de chien a mis en évidence une modification des profils après conservation des spécimens urinaires à - 20°C pour une durée de 15j. Ces modifications n'ont pas été visualisées lors de conservation à T°C ambiante, à 4° ou à -80°C. L'objectif de cette étude prospective est de préciser après quel délai de congélation à -20°C ces modifications apparaissaient et si la nature du tube les influence. Vingt chiens protéinuriques ont été inclus. Après examen urinaire complet, un RPCU et une électrophorèse des protéines urinaires sur gel d’agarose ont été obtenus. L'urine a ensuite été répartie dans différents tubes (Eppendorf® classique, Eppendorf® Protein LoBind et Nunc Cryotube®) et les spécimens ont été congelés à -20°C. Les électrophorèses ont été réitérées après 1, 2, 5 et 15jours. Les mêmes modifications ont été retrouvées quelques soit le tube utilisé. Quatre profils sont modifiés dès J1 ; deux profils supplémentaires sont modifiés dès J2, un et un profil dès J5 et J15, respectivement. L'apparition des modifications est significativement associée à la protéinurie, ainsi qu'à la classification initiale du type de profil. La congélation à -20°C des urines est déconseillée quelle que soit sa durée, pour une interprétation fiable des profils électrophorétiques des protéines urinaires de chiens
Single Frequency Network in a Mobile Broadcast System Based on a Hybrid Satellite/Terrestrial Infrastructure
No full textÉtude prospective secondaire visant à préciser l’influence de la température de conservation des urines sur le profil électrophorétique des protéines urinaires sur gel d’agarose chez le chien protéinurique
No full textA recent study on preanalytical variations of canine UPCR and urine proteins electrophoresis showed that qualitative modifications of electrophoretic patterns were visible when urine specimen were stored for 15 days at -20°C, while they remained unchanged when stored at room temperature, 4°C or -80°C. The objectives of this prospective study were to assess the minimal duration of storage at -20°C before the apparition of these modifications, as well as to evaluate the influence of the tube used for storage. Twenty proteinuric dogs were included after complete urinalysis. Initial UPCR and urine proteins electrophoretic migration on agarose gel were recorded. Urine specimens were aliquoted into different tubes (Eppendorf® classique, Eppendorf® Protein LoBind and Nunc Cryotube) that were stored at -20°C. Urine proteins electrophoresis were performed after 1, 2, 5 and 15 days of storage and compared to the initial profile. Four, 2, 1 and 1 profiles were modified as soon as 1, 2, 5 and 15 days of storage and thereafter, respectively. Apparition of modifications was significantly associated with proteinuria and initial classification of electrophoretic patterns. Storage at -20°C is not recommended, whatever its duration, for a better interpretation of canine urine proteins electrophoretic profiles.Une étude sur les variations préanalytiques des électrophorèses des protéines urinaires de chien a mis en évidence une modification des profils après conservation des spécimens urinaires à - 20°C pour une durée de 15j. Ces modifications n'ont pas été visualisées lors de conservation à T°C ambiante, à 4° ou à -80°C. L'objectif de cette étude prospective est de préciser après quel délai de congélation à -20°C ces modifications apparaissaient et si la nature du tube les influence. Vingt chiens protéinuriques ont été inclus. Après examen urinaire complet, un RPCU et une électrophorèse des protéines urinaires sur gel d’agarose ont été obtenus. L'urine a ensuite été répartie dans différents tubes (Eppendorf® classique, Eppendorf® Protein LoBind et Nunc Cryotube®) et les spécimens ont été congelés à -20°C. Les électrophorèses ont été réitérées après 1, 2, 5 et 15jours. Les mêmes modifications ont été retrouvées quelques soit le tube utilisé. Quatre profils sont modifiés dès J1 ; deux profils supplémentaires sont modifiés dès J2, un et un profil dès J5 et J15, respectivement. L'apparition des modifications est significativement associée à la protéinurie, ainsi qu'à la classification initiale du type de profil. La congélation à -20°C des urines est déconseillée quelle que soit sa durée, pour une interprétation fiable des profils électrophorétiques des protéines urinaires de chiens
The helicase HAGE prevents interferon-a-induced PML expression in ABCB5+ malignant melanoma-initiating cells by promoting the expression of SOCS1
No full textThe tumour suppressor PML (promyelocytic leukaemia protein) regulates several cellular pathways involving cell growth, apoptosis, differentiation and senescence. PML also has an important role in the regulation of stem cell proliferation and differentiation. Here, we show the involvement of the helicase HAGE in the transcriptional repression of PML expression in ABCB5 + malignant melanoma-initiating cells (ABCB5 + MMICs), a population of cancer stem cells which are responsible for melanoma growth, progression and resistance to drug-based therapy. HAGE prevents PML gene expression by inhibiting the activation of the JAK-STAT (janus kinase-signal transducers and activators of transcription) pathway in a mechanism which implicates the suppressor of cytokine signalling 1 (SOCS1). Knockdown of HAGE led to a significant decrease in SOCS1 protein expression, activation of the JAK-STAT signalling cascade and a consequent increase of PML expression. To confirm that the reduction in SOCS1 expression was dependent on the HAGE helicase activity, we showed that SOCS1, effectively silenced by small interfering RNA, could be rescued by re-introduction of HAGE into cells lacking HAGE. Furthermore, we provide a mechanism by which HAGE promotes SOCS1 mRNA unwinding and protein expression in vitro
Identification of Genomic Regions Associated with Phenotypic Variation between Dog Breeds using Selection Mapping
No full textThe extraordinary phenotypic diversity of dog breeds has been sculpted by a unique population history accompanied by selection for novel and desirable traits. Here we perform a comprehensive analysis using multiple test statistics to identify regions under selection in 509 dogs from 46 diverse breeds using a newly developed high-density genotyping array consisting of >170,000 evenly spaced SNPs. We first identify 44 genomic regions exhibiting extreme differentiation across multiple breeds. Genetic variation in these regions correlates with variation in several phenotypic traits that vary between breeds, and we identify novel associations with both morphological and behavioral traits. We next scan the genome for signatures of selective sweeps in single breeds, characterized by long regions of reduced heterozygosity and fixation of extended haplotypes. These scans identify hundreds of regions, including 22 blocks of homozygosity longer than one megabase in certain breeds. Candidate selection loci are strongly enriched for developmental genes. We chose one highly differentiated region, associated with body size and ear morphology, and characterized it using high-throughput sequencing to provide a list of variants that may directly affect these traits. This study provides a catalogue of genomic regions showing extreme reduction in genetic variation or population differentiation in dogs, including many linked to phenotypic variation. The many blocks of reduced haplotype diversity observed across the genome in dog breeds are the result of both selection and genetic drift, but extended blocks of homozygosity on a megabase scale appear to be best explained by selection. Further elucidation of the variants under selection will help to uncover the genetic basis of complex traits and disease.LUPA Consortiu
PML isoforms in response to arsenic: high-resolution analysis of PML body structure and degradation
No full textArsenic is a clinically effective treatment for acute promyelocytic leukaemia (APL) in which the promyelocytic leukaemia (PML) protein is fused to retinoic receptor alpha (RARα). PML-RARα is degraded by the proteasome by a SUMO-dependent, ubiquitin-mediated pathway in response to arsenic treatment, curing the disease. Six major PML isoforms are expressed as a result of alternative splicing, each of which encodes a unique C-terminal region. Using a system in which only a single EYFP-linked PML isoform is expressed, we demonstrate that PMLI, PMLII and PMLVI accumulate in the cytoplasm following arsenic treatment, whereas PMLIII, PMLIV and PMLV do not. 3D structured illumination was used to obtain super-resolution images of PML bodies, revealing spherical shells of PML along with associated SUMO. Arsenic treatment results in dramatic isoform-specific changes to PML body ultrastructure. After extended arsenic treatment most PML isoforms are degraded, leaving SUMO at the core of the nuclear bodies. A high-content imaging assay identifies PMLV as the isoform most readily degraded following arsenic treatment, and PMLIV as relatively resistant to degradation. Immunoprecipitation analysis demonstrates that all PML isoforms are modified by SUMO and ubiquitin after arsenic treatment, and by using siRNA, we demonstrate that arsenic-induced degradation of all PML isoforms is dependent on the ubiquitin E3 ligase RNF4. Intriguingly, depletion of RNF4 results in marked accumulation of PMLV, suggesting that this isoform is an optimal substrate for RNF4. Thus the variable C-terminal domain influences the rate and location of degradation of PML isoforms following arsenic treatment
Genesis of ancestral haplotypes: RNA modifications and reverse transcription–mediated polymorphisms
No full textUnderstanding the genesis of the block haplotype structure of the genome is a major challenge. With the completion of the sequencing of the Human Genome and the initiation of the HapMap project the concept that the chromosomes of the mammalian genome are a mosaic, or patchwork, of conserved extended block haplotype sequences is now accepted by the mainstream genomics research community. Ancestral Haplotypes (AHs) can be viewed as a recombined string of smaller Polymorphic Frozen Blocks (PFBs). How have such variant extended DNA sequence tracts emerged in evolution? Here the relevant literature on the problem is reviewed from various fields of molecular and cell biology particularly molecular immunology and comparative and functional genomics. Based on our synthesis we then advance a testable molecular and cellular model. A critical part of the analysis concerns the origin of the strand biased mutation signatures in the transcribed regions of the human and higher primate genome, A-to-G versus T-to-C (ratio ~1.5 fold) and C-to-T versus G-to-A (≥1.5 fold). A comparison and evaluation of the current state of the fields of immunoglobulin Somatic Hypermutation (SHM) and Transcription-Coupled DNA Repair focused on how mutations in newly synthesized RNA might be copied back to DNA thus accounting for some of the genome-wide strand biases (e.g., the A-to-G vs T-to-C component of the strand biased spectrum). We hypothesize that the genesis of PFBs and extended AHs occurs during mutagenic episodes in evolution (e.g., retroviral infections) and that many of the critical DNA sequence diversifying events occur first at the RNA level, e.g., recombination between RNA strings resulting in tandem and dispersed RNA duplications (retroduplications), RNA mutations via adenosine-to-inosine pre-mRNA editing events as well as error prone RNA synthesis. These are then copied back into DNA by a cellular reverse transcription process (also likely to be error-prone) that we have called "reverse transcription-mediated long DNA conversion." Finally we suggest that all these activities and others can be envisaged as being brought physically under the umbrella of special sites in the nucleus involved in transcription known as "transcription factories."
Hybrid satellite and terrestrial infrastructure for mobile broadcast services delivery: An outlook to the ‘Unlimited Mobile TV’ system performance
No full text
- …
