45 research outputs found

    Optimising halting station of passenger railway lines

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    In many real life passenger railway networks, the types of stations and lines characterisethe halting stations of the train lines. Common types are Regional, Interregional or Intercity.This paper considers the problem of altering the halts of lines by both upgrading and downgrading stations, such that this results in less total travel time. We propose a combination of reduction methods, Lagrangian relaxation, and a problem-specific multiplier adjustment algorithm to solve the presented mixed integer linear programming formulation. A computational study of several real-life instances based on problem data of the Dutch passenger railway operator NS Reizigers is included.mathematical economics and econometrics ;

    A branch-and-cut approach for solving line planning problems

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    An important strategic element in the planning process of a railway operator is the development of a line plan, i.e., a set of routes (paths) in a network of tracks, operated at a given hourly frequency. We consider a model formulation of the line planning problem where total operating costs are to be minimized. This model is solved with a branch-and-cut approach, for which we develop a variety of valid inequalities and reduction methods. A computational study of five real-life instances is included.operations research and management science;

    Teaching an old dog new tricks : activity-on-target interferon to treat T-cell acute lymphoblastic leukemia

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    Background Type 1 interferon (IFN) has a long history in the treatment of cancer, including hematological malignancies. The anti-cancer effects induced by IFN result from a combination of 1) direct cancer cell growth inhibition by cell cycle arrest, apoptosis, or differentiation and 2) the activation of the immune system involving antigen presentation by Clec9A+ dendritic cells and priming of cytotoxic CD8+ T-cells. However, IFN therapy experienced variable and unpredictable success in the clinic. Its clinical application is severely impeded by a complex pattern of adverse side-effects, due to the multifaceted activity pattern of IFN. Therefore, safe exploitation of the anti-cancer potential of IFN requires strategies to direct their activity to selected target cells, avoiding systemic toxicity. Aims Safe exploitation of the anti-cancer potential of IFN requires strategies to direct their activity to selected target cells, avoiding systemic toxicity. Methods To improve the therapeutic index of IFN, we have developed AcTaferons (Activity-on-Target Interferon), optimized (mutant) immunocytokines. Mutated IFNa2Q124R, with a strongly reduced affinity for its receptor complex, was fused to single domain antibodies targeting cell-specific domains, which selectively restores the AcTaferon (AFN) activity in a cell-type specific manner. As such, CD8-AFN and Clec9A-AFN were generated which selectively target either CD8+ T(-ALL) cells or Clec9A+ dendritic cells. Results Using CD8- and CD8+ mouse T-ALL cell lines, we evaluated the direct and indirect anti-leukemic effects of our novel AFNs, in vitro and in vivo upon transplantation in immunocompromised and immunocompetent syngeneic hosts. A significant reduction in the leukemic burden was observed. These anti-cancer effects of AFN were similar as observed for the wildtype IFN, but in a cell-type specific manner and with drastically reduced adverse side-effects. Monotherapy was even sufficient to completely cure a proportion of leukemic mice, which highlights the strong anti-leukemic power of these optimized immunocytokines. Strinkingly only the direct effect CD8-AFN on in vivo CD8+ T-ALL was synergistic with asparaginase treatment. No synergism was observed between asparaginase and the indirect immune-mediated Clec9A-AFN anti-leukemic effect. Conclusion In conclusion, we have developed novel optimized immunocytokines as an off-the-shelve targeted immunotherapy for T-ALL

    TP53 outperforms other androgen receptor biomarkers to predict abiraterone or enzalutamide outcome in metastatic castration-resistant prostate cancer

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    Purpose: To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from patients with metastatic castration-resistant prostate cancer (mCRPC) starting a new line of AR signaling inhibitors (ARSi). Experimental Design: Between March 2014 and April 2017, we recruited patients with mCRPC (n = 168) prior to ARSi in a cohort study encompassing 10 European centers. Blood samples were collected for comprehensive profiling of Cell Search-enriched circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). Targeted CTC RNA sequencing (RNA-seq) allowed the detection of eight AR splice variants (ARV). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss of heterozygosity, mutations, and structural rearrangements in ctDNA. Clinical or radiologic progression-free survival (PFS) was estimated by Kaplan-Meier analysis, and independent associations were determined using multivariable Cox regression models. Results: Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumor burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value [HR 1.88; 95% confidence interval (CI), 1.18-3.00; P = 0.008], and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs. 7.51 vs. 2.62 months; P < 0.0001), which was validated in an independent mCRPC cohort (n = 202) starting first-line ARSi (median, 14.3 vs. 6.39 vs. 2.23 months; P < 0.0001). Conclusions: In an all-comer cohort, tumor burden estimates and TP53 outperform any AR perturbation to infer prognosis. See related commentary by Rebello et al., p. 169
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