168 research outputs found

    New complexity results for parallel identical machine scheduling problems with preemption, release dates and regular criteria

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    In this paper, we are interested in parallel identical machine scheduling problems with preemption and release dates in case of a regular criterion to be minimized. We show that solutions having a permutation flow shop structure are dominant if there exists an optimal solution with completion times scheduled in the same order as the release dates, or if there is no release date. We also prove that, for a subclass of these problems, the completion times of all jobs can be ordered in an optimal solution. Using these two results, we provide new results on polynomially solvable problems and hence refine the boundary between P and NP for these problems

    Anatomical and functional results of ossiculoplasty using titanium prosthesis

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    Titanium ossicular chain replacement prosthesis is often used for rehabilitation of the columellar effect in otologic surgeries. This retrospective study aims to analyse the anatomical and functional results of surgeries in which a titanium prosthesis was used. Two hundred and eighty procedures in 256 patients operated on in a tertiary referral center were analysed. Aetiologies, preoperative audiograms, peropera-tive data and postoperative outcomes at 2 and 12 months postoperatively were reviewed. Chronic suppurative otitis media with or without cholesteatoma was the main aetiology (89%). There was no difference in anatomical results between partial and total ossicular replacement prosthesis, with an overall dislocation rate of 6%, and an overall extrusion rate of 3%. Regarding functional results, a postoperative air-bone gap ≤ 20 dB was achieved in 65% of cases, with a better result for partial compared to total ossiculoplasty (p = 0.02). A significant difference in air bone gap closure was found when comparing aetiologies, with a higher air-bone gap closure in malformation cases compared to chronic suppurative otitis media with cholesteatoma or retraction cases (p = 0.03). Ossiculoplasty using titanium prosthesis is a safe and effective procedure for rehabilitation of hearing loss, which allows reaching an air-bone gap ≤ 20 dB in the majority of patients

    Luxation obturatrice de la hanche: un traumatisme rare en pratique sportive

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    Les luxations antérieures traumatiques de la hanche sans fracture du cotyle ou de la tête fémorale sont rares. Elles sont souvent secondaires à des accidents de haute énergie cinétique. La prise en charge thérapeutique nécessite un chirurgien vigilant et prévenu du risque de complications. Nous rapportons le cas d'une luxation obturatrice (antéro-inférieure) chez un jeune de 18 ans pratiquant le rolle

    LIPOSARCOME DU SEIN. A PROPOS D’UN CAS

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    Liposarcoma of the breast is an unfrequent tumor that can be found in 45-55 year old nwomen, usually with benign clinical and radiological characteristics. We report the case of a 51-year-old patient. Symptomatology began since 1 month by an increase from the left breast with general conservation of the state. The cytoponction evoke the diagnosis of liposarcoma. Four years and half of follow up after mastectomy alone, the evolution is well. No relapse was observed. Beyond the not very frequent character of this pathology, our observation underlines the interest of the early diagnosis of this type of tumour, by screening of breast cancers without mammography among menopausal women.Le liposarcome du sein est une lésion rare, pouvant toucher la femme de 45 à 55 ans en moyenne et qui présente les caractéristiques cliniques et radiologiques d'une lésion bénigne. Nous rapportons ici le cas d'une patiente de 51 ans ménopausée. La symptomatologie débutait depuis un  mois par une augmentation du sein gauche sans signes associés avec conservation de l’état général. La ponction biopsie anatomopathologique a permis d’évoquer le diagnostic de liposarcome du sein. 4 ans et demi de recul après mastectomie seule, l'évolution est satisfaisante. Au-delà du caractère peu fréquent de cette pathologie, notre observation souligne l’intérêt du  diagnostic précoce de ce type de tumeur, grâce aux mammographies systématiques annuelles chez les femmes ménopausées

    Engineering the surface properties of a human monoclonal antibody prevents self-association and rapid clearance in vivo

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    Uncontrolled self-association is a major challenge in the exploitation of proteins as therapeutics. Here we describe the development of a structural proteomics approach to identify the amino acids responsible for aberrant self-association of monoclonal antibodies and the design of a variant with reduced aggregation and increased serum persistence in vivo. We show that the human monoclonal antibody, MEDI1912, selected against nerve growth factor binds with picomolar affinity, but undergoes reversible self-association and has a poor pharmacokinetic profile in both rat and cynomolgus monkeys. Using hydrogen/deuterium exchange and cross-linking-mass spectrometry we map the residues responsible for self-association of MEDI1912 and show that disruption of the self-interaction interface by three mutations enhances its biophysical properties and serum persistence, whilst maintaining high affinity and potency. Immunohistochemistry suggests that this is achieved via reduction of non-specific tissue binding. The strategy developed represents a powerful and generic approach to improve the properties of therapeutic proteins

    Promoter Hypermethylation-Related Reduced Somatostatin Production Promotes Uncontrolled Cell Proliferation in Colorectal Cancer.

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    BACKGROUND: Somatostatin (SST) has anti-proliferative and pro-apoptotic effects. Our aims were to analyze and compare the SST expression during normal aging and colorectal carcinogenesis at mRNA and protein levels. Furthermore, we tested the methylation status of SST in biopsy samples, and the cell growth inhibitory effect of the SST analogue octreotide in human colorectal adenocarcinoma cell line. METHODS: Colonic samples were collected from healthy children (n1 = 6), healthy adults (n2 = 41) and colorectal cancer patients (CRCs) (n3 = 34) for SST mRNA expression analysis, using HGU133 Plus2.0 microarrays. Results were validated both on original (n1 = 6; n2 = 6; n3 = 6) and independent samples ((n1 = 6; n2 = 6; n3 = 6) by real-time PCR. SST expressing cells were detected by immunohistochemistry on colonic biopsy samples (n1 = 14; n2 = 20; n3 = 23). The effect of octreotide on cell growth was tested on Caco-2 cell line. SST methylation percentage in biopsy samples (n1 = 5; n2 = 5; n3 = 9) was defined using methylation-sensitive restriction enzyme digestion. RESULTS: In case of normal aging SST mRNA expression did not alter, but decreased in cancer (p<0.05). The ratio of SST immunoreactive cells was significantly higher in children (0.70%+/-0.79%) compared to CRC (0%+/-0%) (p<0.05). Octreotide significantly increased the proportion of apoptotic Caco-2 cells. SST showed significantly higher methylation level in tumor samples (30.2%+/-11.6%) compared to healthy young individuals (3.5%+/-1.9%) (p<0.05). CONCLUSIONS: In cancerous colonic mucosa the reduced SST production may contribute to the uncontrolled cell proliferation. Our observation that in colon cancer cells octreotide significantly enhanced cell death and attenuated cell proliferation suggests that SST may act as a regulator of epithelial cell kinetics. The inhibition of SST expression in CRC can be epigenetically regulated by promoter hypermethylation

    The direct effect of Focal Adhesion Kinase (FAK), dominant-negative FAK, FAK-CD and FAK siRNA on gene expression and human MCF-7 breast cancer cell tumorigenesis

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    <p>Abstract</p> <p>Background</p> <p>Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in survival signaling. FAK has been shown to be overexpressed in breast cancer tumors at early stages of tumorigenesis.</p> <p>Methods</p> <p>To study the direct effect of FAK on breast tumorigenesis, we developed Tet-ON (tetracycline-inducible) system of MCF-7 breast cancer cells stably transfected with FAK or dominant-negative, C-terminal domain of FAK (FAK-CD), and also FAKsiRNA with silenced FAK MCF-7 stable cell line. Increased expression of FAK in isogenic Tet-inducible MCF-7 cells caused increased cell growth, adhesion and soft agar colony formation <it>in vitro</it>, while expression of dominant-negative FAK inhibitor caused inhibition of these cellular processes. To study the role of induced FAK and FAK-CD <it>in vivo</it>, we inoculated these Tet-inducible cells in nude mice to generate tumors in the presence or absence of doxycycline in the drinking water. FAKsiRNA-MCF-7 cells were also injected into nude mice to generate xenograft tumors.</p> <p>Results</p> <p>Induction of FAK resulted in significant increased tumorigenesis, while induced FAK-CD resulted in decreased tumorigenesis. Taq Man Low Density Array assay demonstrated specific induction of FAKmRNA in MCF-7-Tet-ON-FAK cells. DMP1, encoding cyclin D binding myb-like protein 1 was one of the genes specifically affected by Tet-inducible FAK or FAK-CD in breast xenograft tumors. In addition, silencing of FAK in MCF-7 cells with FAK siRNA caused increased cell rounding, decreased cell viability <it>in vitro </it>and inhibited tumorigenesis <it>in vivo</it>. Importantly, Affymetrix microarray gene profiling analysis using Human Genome U133A GeneChips revealed >4300 genes, known to be involved in apoptosis, cell cycle, and adhesion that were significantly down- or up-regulated (p < 0.05) by FAKsiRNA.</p> <p>Conclusion</p> <p>Thus, these data for the first time demonstrate the direct effect of FAK expression and function on MCF-7 breast cancer tumorigenesis <it>in vivo </it>and reveal specific expression of genes affected by silencing of FAK.</p
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