29 research outputs found

    Retropseudogenes derived from the human Ro/SS-A autoantigen-associated hY RNAs

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    We report the characterization in the human genome of 966 pseudogenes derived from the four human Y (hY) RNAs, components of the Ro/SS-A autoantigen. About 95% of the Y RNA pseudogenes are found in corresponding locations on the chimpanzee and human chromosomes. On the contrary, Y pseudogenes in mice are both infrequent and found in different genomic regions. In addition to this rodent/primate discrepancy, the conservation of hY pseudogenes relative to hY genes suggests that they occurred after rodent/primate divergence. Flanking regions of hY pseudogenes contain convincing evidence for involvement of the L1 retrotransposition machinery. Although Alu elements are found in close proximity to most hY pseudogenes, these are not chimeric retrogenes. Point mutations in hY RNA transcripts specifically affecting binding of Ro60 protein likely contributed to their selection for direct trans retrotransposition. This represents a novel requirement for the selection of specific RNAs for their genomic integration by the L1 retrotransposition machinery. Over 40% of the hY pseudogenes are found in intronic regions of protein-coding genes. Considering the functions of proteins known to bind subsets of hY RNAs, hY pseudogenes constitute a new class of L1-dependent non-autonomous retroelements, potentially involved in post-transcriptional regulation of gene expression

    Charles Gagnon

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    Catalogue for a retrospective exhibition of Gagnon's work since the 1950s. The three authors maintain the importance of Gagnon’s innovations to the development of visual arts in Quebec, stressing the diversity, yet coherence, of the artist ’s production. Godmer reviews the ensemble of works in an analytic/biographical text; Asselin discusses themes of natural landscape, the urban environment and the use of text; while Goyette concentrates on Gagnon’s little-known film work from 1966-1970. Their analyses reveal certain recurrent characteristics: the dynamic potential of fragmentation; the window and sky motifs; the use of codes; movement and exuberance; the spectator’s active role. List of works. Texts in French and English. Biographical information 20 p. Circa 40 bibl. ref

    Transjugular intrahepatic portosystemic shunt before abdominal surgery in cirrhotic patients: A retrospective, comparative study

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    Surgery in cirrhotic patients is associated with high morbidity and mortality related to portal hypertension and liver insufficiency. Therefore, preoperative portal decompression is a logical approach to facilitate abdominal surgery and hopefully to improve postoperative survival. The present study evaluated the clinical outcomes of 18 patients (mean age 58 years) with cirrhosis (seven alcoholics and 11 nonalcoholics) who underwent transjugular intrahepatic portosystemic shunt (TIPS) placement before antrectomy (n=5), colectomy (n=10), small-bowel resection (n=1), pancreatectomy (n=1) and nephrectomy (n=1). TIPS was performed a mean (± SD) of 72±21 days before surgery and induced a marked mean decrease in portohepatic gradient from 21.4±3.9 mmHg to 8.4±3.4 mmHg. Cirrhotic patients (n=17) who underwent elective abdominal surgery without preoperative TIPS placement were used as the control group. Both groups were matched for age, etiology of cirrhosis, indications for surgery, type of surgery and coagulation parameters. The mean Pugh score was significantly higher in the TIPS group (7.7 versus 6.2). No significant differences were observed for operative blood loss, postoperative complications, duration of hospitalization and one-month (83% versus 88%) or one-year (54% versus 63%) cumulative survival rate. Analysis using the Cox proportional hazards model showed that neither TIPS placement nor preoperative Pugh score were independent predictors for survival. The present study suggests that preoperative TIPS placement does not improve postoperative evolution after abdominal surgery in cirrhotic patients with good or moderately impaired liver function
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