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41.
Metronomic treatment in immunocompetent preclinical GL261 glioblastoma: effects of cyclophosphamide and temozolomide 下载免费PDF全文
Laura Ferrer‐Font Nuria Arias‐Ramos Silvia Lope‐Piedrafita Margarida Julià‐Sapé Martí Pumarola Carles Arús Ana Paula Candiota 《NMR in biomedicine》2017,30(9)
Glioblastoma (GBM) causes poor survival in patients even when applying aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment, but resistance always ensues. In previous years, efforts have focused on new therapeutic regimens with conventional drugs to activate immune responses that may enhance tumor regression and prevent regrowth, for example the “metronomic” approaches. In metronomic scheduling studies, cyclophosphamide (CPA) in GL261 GBM growing subcutaneously in C57BL/6 mice was shown not only to activate antitumor CD8+ T‐cell response, but also to induce long‐term specific T‐cell tumor memory. Accordingly, we have evaluated whether metronomic CPA or TMZ administration could increase survival in orthotopic GL261 in C57BL/6 mice, an immunocompetent model. Longitudinal in vivo studies with CPA (140 mg/kg) or TMZ (range 140–240 mg/kg) metronomic administration (every 6 days) were performed in tumor‐bearing mice. Tumor evolution was monitored at 7 T with MRI (T2‐weighted, diffusion‐weighted imaging) and MRSI‐based nosological images of response to therapy. Obtained results demonstrated that both treatments resulted in increased survival (38.6 ± 21.0 days, n = 30) compared with control (19.4 ± 2.4 days, n = 18). Best results were obtained with 140 mg/kg TMZ (treated, 44.9 ± 29.0 days, n = 12, versus control, 19.3 ± 2.3 days, n = 12), achieving a longer survival rate than previous group work using three cycles of TMZ therapy at 60 mg/kg (33.9 ± 11.7 days, n = 38). Additional interesting findings were, first, clear edema appearance during chemotherapeutic treatment, second, the ability to apply the semi‐supervised source analysis previously developed in our group for non‐invasive TMZ therapy response monitoring to detect CPA‐induced response, and third, the necropsy findings in mice cured from GBM after high TMZ cumulative dosage (980–1400 mg/kg), which demonstrated lymphoma incidence. In summary, every 6 day administration schedule of TMZ or CPA improves survival in orthotopic GL261 GBM with respect to controls or non‐metronomic therapy, in partial agreement with previous work on subcutaneous GL261. 相似文献
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Tim Segers Pieter Kruizinga Maarten P. Kok Guillaume Lajoinie Nico de Jong Michel Versluis 《Ultrasound in medicine & biology》2018,44(7):1482-1492
It has been proposed that monodisperse microbubble ultrasound contrast agents further increase the signal-to-noise ratio of contrast-enhanced ultrasound imaging. Here, the sensitivity of a polydisperse pre-clinical agent was compared experimentally with that of its size- and acoustically sorted derivatives by using narrowband pressure- and frequency-dependent scattering and attenuation measurements. The sorted monodisperse agents had up to a two-orders-of-magnitude increase in sensitivity, that is, in the average scattering cross section per bubble. Moreover, we found, for the first time, that the highly non-linear response of acoustically sorted microbubbles can be exploited to confine scattering and attenuation to the focal region of ultrasound fields used in clinical imaging. This property is a result of minimal pre-focal scattering and attenuation and can be used to minimize shadowing effects in deep tissue imaging. Moreover, it potentially allows for more localized therapy using microbubbles through the spatial control of resonant microbubble oscillations. 相似文献
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Background: The sanction that an athlete receives when an anti-doping rule violation has been committed depends on the specific circumstances of the case. Anti-doping tribunals decide on the final sanction, following the rules of the World Anti-Doping Code. Objectives: To assess the athletes’ degree of fault based on the length of sanctions imposed on them to feed policy-related discussions. Methods: Analysing data from the results management database of the World Anti-Doping Agency for anonymous information of anti-doping rule violations in eight selected sports covering the years 2010-2012. Results: Four out of ten athletes who committed an anti-doping rule violation received a suspension that was lower than the standard. This is an indication that tribunals in many instances are not convinced that the athletes concerned were completely at fault, that mitigating circumstances were applicable, or that full responsibility of the suspected violation should not be held against them. Anabolic agents, peptide hormones, and hormone modulators lead to higher sanctions, as do combinations of several anti-doping rule violations. Conclusions: This first analysis of information from the World Anti-Doping Agency's results management database indicates that a large proportion of the athletes who commit anti-doping rule violations may have done this unintentionally. Anti-doping professionals should strive to improve this situation in various ways. 相似文献
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Diffusion‐prepared stimulated‐echo turbo spin echo (DPsti‐TSE): An eddy current‐insensitive sequence for three‐dimensional high‐resolution and undistorted diffusion‐weighted imaging 下载免费PDF全文
Qinwei Zhang Bram F. Coolen Maarten J. Versluis Gustav J. Strijkers Aart J. Nederveen 《NMR in biomedicine》2017,30(7)
In this study, we present a new three‐dimensional (3D), diffusion‐prepared turbo spin echo sequence based on a stimulated‐echo read‐out (DPsti‐TSE) enabling high‐resolution and undistorted diffusion‐weighted imaging (DWI). A dephasing gradient in the diffusion preparation module and rephasing gradients in the turbo spin echo module create stimulated echoes, which prevent signal loss caused by eddy currents. Near to perfect agreement of apparent diffusion coefficient (ADC) values between DPsti‐TSE and diffusion‐weighted echo planar imaging (DW‐EPI) was demonstrated in both phantom transient signal experiments and phantom imaging experiments. High‐resolution and undistorted DPsti‐TSE was demonstrated in vivo in prostate and carotid vessel wall. 3D whole‐prostate DWI was achieved with four b values in only 6 min. Undistorted ADC maps of the prostate peripheral zone were obtained at low and high imaging resolutions with no change in mean ADC values [(1.60 ± 0.10) × 10?3 versus (1.60 ± 0.02) × 10?3 mm2/s]. High‐resolution 3D DWI of the carotid vessel wall was achieved in 12 min, with consistent ADC values [(1.40 ± 0.23) × 10?3 mm2/s] across different subjects, as well as slice locations through the imaging volume. This study shows that DPsti‐TSE can serve as a robust 3D diffusion‐weighted sequence and is an attractive alternative to the traditional two‐dimensional DW‐EPI approaches. 相似文献
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Omer Onur Cakir Fabio Castiglione Zafer Tandogdu Justin Collins Hussain M. Alnajjar Clare Akers Maarten Albersen Constantine Alifrangis Benjamin Ayres Oscar Brouwer Ivor Cullen Peter Hawkey Jakob Kristian Jakobsen Truls Erik Bjerklund Johansen Odunayo Kalejaiye Asheesh Kaul Bela Köves Vivekanandan Kumar Asif Muneer 《Urologic oncology》2021,39(3):197.e9-197.e17
ObjectivesTo develop an international consensus on managing penile cancer patients during the COVID-19 acute waves. A major concern for patients with penile cancer during the coronavirus disease 2019 (COVID-19) pandemic is how the enforced safety measures will affect their disease management. Delays in diagnosis and treatment initiation may have an impact on the extent of the primary lesion as well as the cancer-specific survival because of the development and progression of inguinal lymph node metastases.Materials and methodsA review of the COVID-19 literature was conducted in conjunction with analysis of current international guidelines on the management of penile cancer. Results were presented to an international panel of experts on penile cancer and infection control by a virtual accelerated Delphi process using 4 survey rounds. Consensus opinion was defined as an agreement of ≥80%, which was used to reconfigure management pathways for penile cancer.ResultsLimited evidence is available for delaying penile cancer management. The consensus rate of agreement was 100% that penile cancer pathways should be reconfigured, and measures should be developed to prevent perioperative nosocomial transmission of COVID-19. The panel also reached a consensus on several statements aimed at reconfiguring the management of penile cancer patients during the COVID-19 pandemic.ConclusionsThe international consensus panel proposed a framework for the diagnostic and invasive therapeutic procedures for penile cancer within a low-risk environment for COVID-19. 相似文献
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Maarten Bloemen Stefaan Vandendriessche Vincent Goovaerts Ward Brullot Maarten Vanbel Sophie Carron Nick Geukens Tatjana Parac-Vogt Thierry Verbiest 《Materials》2014,7(2):1155-1164
Rare earth atoms exhibit several interesting properties, for example, large magnetic moments and luminescence. Introducing these atoms into a different matrix can lead to a material that shows multiple interesting effects. Holmium atoms were incorporated into an iron oxide nanoparticle and the concentration of the dopant atom was changed in order to determine its influence on the host crystal. Its magnetic and magneto-optical properties were investigated by vibrating sample magnetometry and Faraday rotation measurements. The luminescent characteristics of the material, in solution and incorporated in a polymer thin film, were probed by fluorescence experiments. 相似文献
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