80 research outputs found

    Irreducible triangulations of surfaces with boundary

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    A triangulation of a surface is irreducible if no edge can be contracted to produce a triangulation of the same surface. In this paper, we investigate irreducible triangulations of surfaces with boundary. We prove that the number of vertices of an irreducible triangulation of a (possibly non-orientable) surface of genus g>=0 with b>=0 boundaries is O(g+b). So far, the result was known only for surfaces without boundary (b=0). While our technique yields a worse constant in the O(.) notation, the present proof is elementary, and simpler than the previous ones in the case of surfaces without boundary

    Cell cycle and aging, morphogenesis, and response to stimuli genes are individualized biomarkers of glioblastoma progression and survival

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    <p>Abstract</p> <p>Background</p> <p>Glioblastoma is a complex multifactorial disorder that has swift and devastating consequences. Few genes have been consistently identified as prognostic biomarkers of glioblastoma survival. The goal of this study was to identify general and clinical-dependent biomarker genes and biological processes of three complementary events: lifetime, overall and progression-free glioblastoma survival.</p> <p>Methods</p> <p>A novel analytical strategy was developed to identify general associations between the biomarkers and glioblastoma, and associations that depend on cohort groups, such as race, gender, and therapy. Gene network inference, cross-validation and functional analyses further supported the identified biomarkers.</p> <p>Results</p> <p>A total of 61, 47 and 60 gene expression profiles were significantly associated with lifetime, overall, and progression-free survival, respectively. The vast majority of these genes have been previously reported to be associated with glioblastoma (35, 24, and 35 genes, respectively) or with other cancers (10, 19, and 15 genes, respectively) and the rest (16, 4, and 10 genes, respectively) are novel associations. <it>Pik3r1</it>, <it>E2f3, Akr1c3</it>, <it>Csf1</it>, <it>Jag2</it>, <it>Plcg1</it>, <it>Rpl37a</it>, <it>Sod2</it>, <it>Topors</it>, <it>Hras</it>, <it>Mdm2, Camk2g</it>, <it>Fstl1</it>, <it>Il13ra1</it>, <it>Mtap </it>and <it>Tp53 </it>were associated with multiple survival events.</p> <p>Most genes (from 90 to 96%) were associated with survival in a general or cohort-independent manner and thus the same trend is observed across all clinical levels studied. The most extreme associations between profiles and survival were observed for <it>Syne1</it>, <it>Pdcd4</it>, <it>Ighg1</it>, <it>Tgfa</it>, <it>Pla2g7</it>, and <it>Paics</it>. Several genes were found to have a cohort-dependent association with survival and these associations are the basis for individualized prognostic and gene-based therapies. <it>C2</it>, <it>Egfr</it>, <it>Prkcb</it>, <it>Igf2bp3</it>, and <it>Gdf10 </it>had gender-dependent associations; <it>Sox10</it>, <it>Rps20</it>, <it>Rab31</it>, and <it>Vav3 </it>had race-dependent associations; <it>Chi3l1</it>, <it>Prkcb</it>, <it>Polr2d</it>, and <it>Apool </it>had therapy-dependent associations. Biological processes associated glioblastoma survival included morphogenesis, cell cycle, aging, response to stimuli, and programmed cell death.</p> <p>Conclusions</p> <p>Known biomarkers of glioblastoma survival were confirmed, and new general and clinical-dependent gene profiles were uncovered. The comparison of biomarkers across glioblastoma phases and functional analyses offered insights into the role of genes. These findings support the development of more accurate and personalized prognostic tools and gene-based therapies that improve the survival and quality of life of individuals afflicted by glioblastoma multiforme.</p

    Open side-to-side repair for non-repairable tendon-to-bone rotator cuff tear. Clinical and anatomic outcome at a mean 5 years' follow-up

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    AbstractIntroductionAnatomical tendon-to-bone repair of retracted rotator cuff tear is a difficult challenge given the high rate of recurrence.HypothesisThe study hypothesis was that side-to-side repair of U-shaped retracted tear allows tendon healing with satisfactory medium-term clinical results.Materials and methodsBetween 1999 and 2007, 35patients (mean age 53.5years) were operated on with this open technique. On the De Orio and Cofield classification, tendon lesions were medium in 5cases, large in 25 and massive in 5. Subacromial space was in all cases greater than 7mm. Fatty infiltration grade was less than or equal to 2 on Goutallier's classification in all cases except for 1 grade3 (supraspinatus only). At last follow-up, patients were assessed clinically (Constant score) and radiographically. Tendon healing was assessed by ultrasound (31 cases) or CT-arthrography (4cases).ResultsMean follow-up was 60months. Constant score improved significantly, from 64.7±10 preoperatively to 77.1±14 postoperatively (P<0.05). Recurrence rate was 17.1%. Subacromial space was<6mm postoperatively in 2cases.DiscussionSide-to-side repair, bringing the posterior cuff onto the anterior edge of the tear, allowed tension-free repair of retracted tear if the preoperative reparability criteria are met: subacromial space equal to or greater than 7mm, and absence of fatty infiltration significantly greater than grade 2 on the Goutallier classification. Under these conditions, clinical and anatomical results were satisfactory at a mean 5years’ follow-up.Level of evidenceIV, retrospective
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