369 research outputs found

    Противоречивые вопросы лечения рака почки: выбор дальнейшей стратегии в случае прогрессирования на фоне VEGF-т аргетной терапии

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    Эверолимус, представляющий собой ингибитор mTOR (mammalian target of rapamycin – мишень рапамицина у млекопитающих), и акситиниб, относящийся к группе ингибиторов тирозинкиназы (ИТК), в настоящее время являются единственными препаратами, официально зарегистрированными для лечения метастатического рака почки (МРП) после уже проведенной терапии первой линии. Экстраполяция достаточно убедительных результатов, полученных в исследованиях III фазы, позволяет предполагатьсхожие значения медианы выживаемости без прогрессирования (ВБП) при применении обоих этих препаратов. Таким образом, в процессе планирования схемы лечения МРП врач сталкивается с непростым вопросом: какая последовательность терапии более оптимальна – ингибитор mTOR после ИТК или 2 различных ИТК друг за другом? При этом из‑за отсутствия данных прямого сравнения акситиниба и эверолимуса клиницист не имеет ясных указаний относительно выбора терапии второй линии – какой из них будет наиболее обоснованным. В исследованиях III фазы было показано: как эверолимус, так и акситиниб предотвращали дальнейшее прогрессирование заболевания после уже проведенной терапии первой линии. Кумулятивная токсичность, характерная для последовательного применения различных ИТК, может послужить причиной более частых перерывов в терапии или снижения дозы, а также повысить вероятность нежелательных явлений. В то время как эверолимус представляется пред-почтительнее с точки зрения переносимости, акситиниб позволяет добиться более высокой частоты ответов; при этом увеличение ВБП в обоих случаях оказывается сопоставимым. Таким образом, при выборе последовательности лечения МРП доказательно обосновать превосходство одного вида терапии над другим не представляется возможным. Вместо этого в процессе планирования лечения необходимо принимать во внимание долгосрочные перспективы, включающие качество жизни, выбирая оптимальный баланс между контролем имеющихся клинических проявлений и контролем возможных нежелательных явлений, который при этом позволил бы свести к минимуму случаи перерывов в терапии или снижения доз. В отсутствие методов радикального лечения одна из основных задач подобной терапии должна заключаться в поддержании качества жизни, а приоритетным критерием для выбора препарата второй линии должна быть возможность выполнения этого условия путем сведения к минимуму вероятности нежелательных явлений

    Optimization-based reference calculation for Modular Multilevel Converters in balanced and unbalanced network conditions

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    © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper addresses an optimization-based algorithm to calculate the references of the Modular Multilevel Converter (MMC) during normal and constrained scenarios (when the prioritization of quantities is required). The optimization problem prioritizes to satisfy the positive- and negative-sequence active and reactive current set-points demanded by the Transmission System Operator (TSO) through the corresponding grid code. If the TSO’s requirements are achieved, the algorithm minimizes the arm impedances losses. Otherwise, it attempts to reduce the error between the current components and the TSO’s current set-points. The optimization-based current reference calculation is derived based on the steady-state equations of the MMC, considering the maximum currents that can flow through the MMC’s arms, the maximum and minimum arm applied voltages and the maximum sub-module capacitor’s voltage. Simulation in the time-domain have been conducted and the results indicate that this method can be potentially employed to calculate the converter’s references during both normal and faulted conditions.Peer ReviewedPostprint (author's final draft

    Improved current reference calculation for MMCs internal energy balancing control

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    © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper addresses an improved inner current reference calculation to be employed in the control of modular multilevel converters operating during either balanced or unbalanced conditions. The suggested reference calculation is derived based on the AC and DC additive and differential voltage components applied to the upper and lower arms of the converter. In addition, the impacts caused not only by the AC networks impedances but also by the MMCs arm impedances are also considered during the derivation of the AC additive current reference expressions. Another issue discussed in this article regards that singular voltage conditions, where the positive-sequence component is equal to the negative one, may occur not only in the AC network but also internally (within the converters applied voltages). Several different inner current reference calculation methods are compared and their applicability during the former fault conditions is analyzed. The paper presents a detailed formulation of the inner current reference calculation and applies it to different unbalanced AC grid faults where it is shown that the presented approach can be potentially used to maintain the internal energy of the converter balanced during normal and fault conditions.Peer ReviewedPostprint (author's final draft

    Real-time optimization-based reference calculation integrated control for MMCs considering converter limitations

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    © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper addresses a real-time optimization-based reference calculation integrated with a control structure for Modular Multilevel Converters (MMC) operating under normal and constrained situations (where it has reached current and/or voltage limitations, e.g. during system faults). The algorithm prioritizes to satisfy the Transmission System Operators (TSO) AC grid current demanded set-points. The constrained optimization problem is formulated based on the steady-state model of the MMC, whereby the prioritization is achieved through distinct weights defined in the Objective Function’s (OF) terms. The resultant optimization problem, however, is highly nonlinear requiring high computation burden to be solved in real-time. To overcome this issue, this paper applies a Linear Time-Varying (LTV) approximation, where the nonlinear dynamics of the system are represented as constant parameters, while a Linear Time-Invariant (LTI) system is used to formulate the optimization constraints. The converter's current references are determined in real-time by solving a constrained linearized optimization problem at each control time step, considering the TSO's demands, the current MMC operating point and its physical limitations. Finally, the linearized-optimization problem is integrated with the MMC controllers and evaluated under different network conditions, where the results indicated that method can be potentially employed to obtain the MMCs current references.Peer ReviewedPostprint (author's final draft

    Identification of prefoldin amplification (1q23.3-q24.1) in bladder cancer using comparative genomic hybridization (CGH) arrays of urinary DNA

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    Background: Array-CGH represents a comprehensive tool to discover genomic disease alterations that could potentially be applied to body fluids. In this report, we aimed at applying array-CGH to urinary samples to characterize bladder cancer. Methods: Urinary DNA from bladder cancer patients and controls were hybridized on 44K oligonucleotide arrays. Validation analyses of identified regions and candidates included fluorescent in situ hybridization (FISH) and immunohistochemistry in an independent set of bladder tumors spotted on custom-made tissue arrays (n = 181). Results: Quality control of array-CGH provided high reproducibility in dilution experiments and when comparing reference pools. The most frequent genomic alterations (minimal recurrent regions) among bladder cancer urinary specimens included gains at 1q and 5p, and losses at 10p and 11p. Supervised hierarchical clustering identified the gain at 1q23.3-q24.1 significantly correlated to stage (p = 0.011), and grade (p = 0.002). The amplification and overexpression of Prefoldin (PFND2), a selected candidate mapping to 1q23.3-q24.1, correlated to increasing stage and tumor grade by means of custom-designed and optimized FISH (p = 0.013 and p = 0.023, respectively), and immunohistochemistry (p ≤0.0005 and p = 0.011, respectively), in an independent set of bladder tumors included in tissue arrays. Moreover, PFND2 overexpression was significantly associated with poor disease-specific survival (p ≤0.0005). PFND2 was amplified and overexpressed in bladder tumors belonging to patients providing urinary specimens where 1q23.3q24.1 amplification was detected by array-CGH. Conclusions: Genomic profiles of urinary DNA mirrowed bladder tumors. Molecular profiling of urinary DNA using array-CGH contributed to further characterize genomic alterations involved in bladder cancer progression. PFND2 was identified as a tumor stratification and clinical outcome prognostic biomarker for bladder cancer patients

    Identification of prefoldin amplification (1q23.3-q24.1) in bladder cancer using comparative genomic hybridization (CGH) arrays of urinary DNA

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    Array-CGH represents a comprehensive tool to discover genomic disease alterations that could potentially be applied to body fluids. In this report, we aimed at applying array-CGH to urinary samples to characterize bladder cancer. Methods: Urinary DNA from bladder cancer patients and controls were hybridized on 44K oligonucleotide arrays. Validation analyses of identified regions and candidates included fluorescent in situ hybridization (FISH) and immunohistochemistry in an independent set of bladder tumors spotted on custom-made tissue arrays (n = 181). Results: Quality control of array-CGH provided high reproducibility in dilution experiments and when comparing reference pools. The most frequent genomic alterations (minimal recurrent regions) among bladder cancer urinary specimens included gains at 1q and 5p, and losses at 10p and 11p. Supervised hierarchical clustering identified the gain at 1q23.3-q24.1 significantly correlated to stage (p = 0.011), and grade (p = 0.002). The amplification and overexpression of Prefoldin (PFND2), a selected candidate mapping to 1q23.3-q24.1, correlated to increasing stage and tumor grade by means of custom-designed and optimized FISH (p = 0.013 and p = 0.023, respectively), and immunohistochemistry (p ≤0.0005 and p = 0.011, respectively), in an independent set of bladder tumors included in tissue arrays. Moreover, PFND2 overexpression was significantly associated with poor disease-specific survival (p ≤0.0005). PFND2 was amplified and overexpressed in bladder tumors belonging to patients providing urinary specimens where 1q23.3q24.1 amplification was detected by array-CGH. Conclusions: Genomic profiles of urinary DNA mirrowed bladder tumors. Molecular profiling of urinary DNA using array-CGH contributed to further characterize genomic alterations involved in bladder cancer progression. PFND2 was identified as a tumor stratification and clinical outcome prognostic biomarker for bladder cancer patientsSupported by grants (SAF2009-13035 and SAF2012-40206) from the Spanish Ministry of Education and Culture (to Dr Sánchez-Carbayo). Virginia López is recipient of a predoctoral award from the Spanish Ministry of Education and Cultur

    Reexamining treatment of high-grade T1 bladder cancer according to depth of lamina propria invasion: a prospective trial of 200 patients

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    BACKGROUND: Management of high-grade T1 (HGT1) bladder cancer represents a major challenge. We studied a treatment strategy according to substaging by depth of lamina propria invasion. METHODS: In this prospective observational cohort study, patients received initial transurethral resection (TUR), mitomycin-C, and BCG. Subjects with shallower lamina propria invasion (HGT1a) were followed without further surgery, whereas subjects with HGT1b received a second TUR. Association of clinical and histological features with outcomes (primary: progression; secondary: recurrence and cancer-specific survival) was assessed using Cox regression. RESULTS: Median age was 71 years; 89.5% were males, with 89 (44.5%) cases T1a and 111 (55.5%) T1b. At median follow-up of 71 months, disease progression was observed in 31 (15.5%) and in univariate analysis, substaging, carcinoma in situ, tumour size, and tumour pattern predicted progression. On multivariate analysis only substaging, associated carcinoma in situ, and tumour size remained significant for progression. CONCLUSIONS: In HGT1 bladder cancer, the strategy of performing a second TUR only in T1b cases results in a global low progression rate of 15.5%. Tumours deeply invading the lamina propria (HGT1b) showed a three-fold increase in risk of progression. Substaging should be routinely evaluated, with HGT1b cases being thoroughly evaluated for cystectomy. Inclusion in the TNM system should also be carefully considered

    Transcriptomic analysis of micropapillary high grade T1 urothelial bladder cancer

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    No consensus currently exist on the optimal treatment of patients with high-risk nonmuscle invasive (HGT1) micropapillary variant of bladder cancer (MPBC). Transcripsome analysis may allow stratification of MPBC-HGT1 enabling prediction of recurrence and guide therapeutic management for individual patients. Whole transcriptome RNA-Sequencing of tumors from 23 patients with MPBC-HGT1 and 64 conventional urothelial carcinomas (cUC) (reference set) was performed. Differentially expressed genes between MPBC-HGT1 and cUC-HGT1 were explored. Cox proportional hazard models and Kapplan-Meier methods were used to assess the relation between time to progression (TTP) and individual gene expression adjusting for clinical covariates. Over 3000 genes were differentially expressed in MPBC-HGT1 as compared with cUC-HGT1 and a 26-gene signature is characteristic of MPBC within HGT1. A set of three genes; CD36, FAPB3 and RAETE1 ; were significantly associated with TTP. High expression of FABP3 and CD36 were associated with shorter TTP (p = 0.045 and p = 0.08) as was low expression of RAET1E (p = 0.01). Our study suggest that a 26-gene signature can define MPBC-HGT1 within conventional urothelial carcinomas. A prognostic risk index of three genes (FABP3, CD36 and RAET1E) was found to be associated with shorter TTP and may help classify a group of patients with MPBC-HGT1 with high-risk of early progression. These observations might have implications in terms of radical cystectomy recommendation in MPBC patients

    Mocetinostat for patients with previously treated, locally advanced/metastatic urothelial carcinoma and inactivating alterations of acetyltransferase genes

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    BackgroundThe authors evaluated mocetinostat (a class I/IV histone deacetylase inhibitor) in patients with urothelial carcinoma harboring inactivating mutations or deletions in CREB binding protein [CREBBP] and/or E1A binding protein p300 [EP300] histone acetyltransferase genes in a singleâ arm, openâ label phase 2 study.MethodsEligible patients with platinumâ treated, advanced/metastatic disease received oral mocetinostat (at a dose of 70 mg 3 times per week [TIW] escalating to 90 mg TIW) in 28â day cycles in a 3â stage study (ClinicalTrials.gov identifier NCT02236195). The primary endpoint was the objective response rate.ResultsGenomic testing was feasible in 155 of 175 patients (89%). Qualifying tumor mutations were CREBBP (15%), EP300 (8%), and both CREBBP and EP300 (1%). A total of 17 patients were enrolled into stage 1 (the intentâ toâ treat population); no patients were enrolled in subsequent stages. One partial response was observed (11% [1 of 9 patients; the population that was evaluable for efficacy comprised 9 of the 15 planned patients]); activity was deemed insufficient to progress to stage 2 (null hypothesis: objective response rate of â ¤15%). All patients experienced â ¥1 adverse event, most commonly nausea (13 of 17 patients; 77%) and fatigue (12 of 17 patients; 71%). The median duration of treatment was 46 days; treatment interruptions (14 of 17 patients; 82%) and dose reductions (5 of 17 patients; 29%) were common. Mocetinostat exposure was lower than anticipated (doseâ normalized maximum serum concentration [Cmax] after TIW dosing of 0.2 ng/mL/mg).ConclusionsTo the authorsâ knowledge, the current study represents the first clinical trial using genomicâ based selection to identify patients with urothelial cancer who are likely to benefit from selective histone deacetylase inhibition. Mocetinostat was associated with significant toxicities that impacted drug exposure and may have contributed to modest clinical activity in these pretreated patients. The efficacy observed was considered insufficient to warrant further investigation of mocetinostat as a single agent in this setting.After the genomicâ based selection of patients with urothelial cancer with inactivating mutations/deletions in the histone acetyltransferase genes CREBBP and/or EP300, singleâ agent mocetinostat appears to be associated with significant toxicities that limit drug exposure. This may have contributed to the limited activity noted in the current phase 2 study (response rate of 11%) among heavily pretreated patients with platinumâ refractory disease.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147860/1/cncr31817_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147860/2/cncr31817.pd
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