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1.
Animals (Basel) ; 14(7)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38612251

RESUMO

The present study aimed to examine the stereoselective pharmacokinetics of racemic ketamine in dogs at low doses. The secondary aims were to identify associated behavioural effects and propose a ketamine infusion rate. The study was conducted on nine intact male beagles, with each dog undergoing two treatments (BOL and INF). For treatment BOL, an intravenous bolus of 1 mg/kg was administered over 2 min. The treatment INF involved an initial bolus of 0.5 mg/kg given over 1 min, followed by an infusion at 0.01 mg/kg/min for 1 h. Blood samples were collected for pharmacokinetic analysis. The median R/S enantiomer ratio of ketamine remained close to 1 throughout the study. Levels of S-norketamine were significantly higher than those of R-norketamine across all time points. Based on the collected data, the infusion rate predicted to achieve a steady-state racemic ketamine plasma concentration of 150 ng/mL was 0.028 mg/kg/min. Higher scores for behavioural effects were observed within the first five minutes following bolus administration. The most common behaviours observed were disorientation, head movements and staring eyes. Furthermore, employing ROC curve analysis, a racemic ketamine plasma concentration of 102 ng/mL was defined as the cut-off value, correlating with the occurrence of undesirable behavioural patterns.

3.
Eur J Cancer ; 198: 113475, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159337

RESUMO

BACKGROUND: Zotiraciclib (TG02) is an oral multi-cyclin dependent kinase (CDK) inhibitor thought to inhibit tumor growth via CDK-9-dependent depletion of survival proteins such as c-MYC and MCL-1 which are frequently overexpressed in glioblastoma. METHODS: EORTC 1608 (NCT03224104) (STEAM) had a three parallel group (A,B,C) phase Ib, open-label, non-randomized, multicenter design in IDH wild-type newly diagnosed glioblastoma or anaplastic astrocytoma. Groups A and B explored the maximum tolerated dose (MTD) of TG02 in elderly patients, in combination with hypofractionated radiotherapy alone (group A) or temozolomide alone (group B), according to O6-methylguanine DNA methyltransferase promoter methylation status determined centrally. Group C explored single agent activity of TG02 at first relapse after temozolomide chemoradiotherapy with a primary endpoint of progression-free survival at 6 months (PFS-6). Tumor expression of CDK-9, c-MYC and MCL-1 was determined by immunohistochemistry. RESULTS: The MTD was 150 mg twice weekly in combination with radiotherapy alone (group A) or temozolomide alone (group B). Two dose-limiting toxicities were observed at 150 mg: one in group A (grade 3 seizure), one in group B (multiple grade 1 events). Main toxicities included neutropenia, gastrointestinal disorders and hepatotoxicity. PFS-6 in group C was 6.7%. CDK-9, c-MYC and MCL-1 were confirmed to be expressed and their expression was moderately cross-correlated. High protein levels of MCL-1 were associated with inferior survival. CONCLUSIONS: TG02 exhibits overlapping toxicity with alkylating agents and low single agent clinical activity in recurrent glioblastoma. The role of CDK-9 and its down-stream effectors as prognostic factors and therapeutic targets in glioblastoma warrants further study.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Compostos Heterocíclicos de 4 ou mais Anéis , Humanos , Idoso , Glioblastoma/tratamento farmacológico , Glioblastoma/radioterapia , Temozolomida/uso terapêutico , Dacarbazina/uso terapêutico , Proteína de Sequência 1 de Leucemia de Células Mieloides/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/radioterapia , Recidiva Local de Neoplasia/tratamento farmacológico , Inibidores Enzimáticos , Antineoplásicos Alquilantes/uso terapêutico
4.
Sci Rep ; 13(1): 19551, 2023 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-37945629

RESUMO

Erythrocyte aggregation kinetics is accelerated in diseases with a strong inflammation component. This study aimed to evaluate whether, in an emergency setting, a new point-of-care test measuring erythrocyte aggregation kinetics (EAK) can identify patients with underlying inflammation. Patients visiting an emergency department and needing a blood exam were successively included. EAK was measured at the point-of-care in 20 s directly on the blood samples collected in regular tubes without any manipulation. The primary measure was EAK's half-life during the first 5 s (EAK5s). Each patient's inflammation status was assessed blind to the EAK test results. Receiver Operating Characteristic (ROC) curves for inflammation status were built. 268 patients had their EAK5s measured, and a clear inflammation status was determined for 214 patients (65 had inflammation). Mean EAK5s were 2.18 s and 1.75 s for no inflammation and inflammation groups respectively (p < 0.001). EAK5s appears to be a better inflammation marker than C-Reactive protein (CRP), with an area under the ROC curve of 0.845 compared to 0.806 for CRP (p < 0.0001). The Youden threshold for prediction of inflammation was 1.86 s with 84.6% (78.5-89.9%) specificity and 70.8% (60-81.5%) sensitivity. Point-of-care EAK is an easily measured, immediately available marker of inflammation with a better predictive power than CRP's.


Assuntos
Proteína C-Reativa , Inflamação , Humanos , Sensibilidade e Especificidade , Valor Preditivo dos Testes , Inflamação/diagnóstico , Proteína C-Reativa/análise , Curva ROC , Testes Imediatos , Biomarcadores
5.
Arch Pediatr ; 30(1): 36-41, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36473753

RESUMO

In 2019, the French National Authority for Health (Haute Autorité de Santé, HAS) published guidelines on the diagnosis of undernutrition. The present article focuses on the impact of switching from the 2012 guidelines of the Nutrition Committee of the French Paediatric Society (CNSFP) to the HAS guidelines on the frequency of hospital undernutrition in children. We selected for the period 2010-2019 from the ePINUT database: (1) all children aged more than 2 years with (2) clinically confirmed nutritional status in (3) French sites. The frequency of undernutrition was 15.4% vs. 28.8% using the CNSFP and HAS criteria, respectively (p < 0.01; n = 6304). When compared to non-malnourished children regardless of the criteria used, malnourished children: (1) stayed longer in hospital (CNSFP: 9.0 ±â€¯11.8 vs. 6.5 ±â€¯8.7 days, p < 0.01; HAS: 7.8 ±â€¯10.1 vs. 6.4 ±â€¯8.4 days, p < 0.01), (2) gained more weight during hospitalization (% of weight at admission) (CNSFP: +1.4 ±â€¯4.1 vs. -0.3 ±â€¯3.5%, p < 0.01; HAS: +2.3 ±â€¯4.7 vs. -0.1 ±â€¯3.4%, p < 0.01), and (3) received nutritional support more frequently during hospitalization (CNSFP: 20% vs. 5%, p < 0.01; HAS: 13% vs. 4%, p < 0.01). Switching to the HAS guidelines resulted in an almost twofold higher frequency of undernutrition in hospitalized children. Initiation of nutritional care remained low considering the nutritional status. The present study warrants interventional studies to determine which children may benefit more from nutritional therapy to improve their outcome.


Assuntos
Desnutrição , Criança , Humanos , Desnutrição/diagnóstico , Desnutrição/epidemiologia , Estado Nutricional , Hospitalização , Apoio Nutricional , Hospitais , Avaliação Nutricional
6.
Metabolites ; 12(10)2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36295801

RESUMO

While clinical evidence remains limited, an extensive amount of research suggests a beneficial role of n-3 polyunsaturated fatty acid supplementation in cancer treatment. One potential benefit is an improvement of protein homeostasis, but how protein metabolism depends on proinflammatory cytokines in this context remains unclear. Here, using the natural abundance of the stable isotopes of nitrogen as a marker of changes in protein metabolism during a randomized, double-blind, controlled clinical trial, we show that protein homeostasis is affected way faster than proinflammatory cytokines in metastatic breast cancer patients supplemented with n-3 polyunsaturated fatty acids. We provide some evidence that this response is unrelated to major changes in whole-body substrate oxidation. In addition, we demonstrate that more fatty acids were impacted by metabolic regulations than by differences in their intake levels during the supplementation. This study documents that the percentage of patients that complied with the supplementation decreased with time, making compliance assessment crucial for the kinetic analysis of the metabolic and inflammatory responses. Our results highlight the time-dependent nature of metabolic and inflammatory changes during long-chain n-3 fatty acid supplementation.

7.
Sci Rep ; 12(1): 14798, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042260

RESUMO

Erythrocyte aggregation (EA) is a physiological process by which erythrocytes reversibly stick together within the blood vessels. EA plays a major role in blood viscosity in vivo, thereby impacting blood flow to organs. EA is no doubt greatly important in both physiological and pathophysiological conditions, but the studies its importance calls for are complicated by the lack of a reliable and easy way to measure it. We have developed a new point-of-care technique which can very specifically measure EA initial kinetics (EAK) in 20 s directly on blood samples routinely collected in tubes commonly used in clinical settings. We present the results of the validation studies of this EAK test: A mono-exponential curve explains 99% of EAK variance. EAK is normally distributed in healthy individuals, with an interindividual 15% coefficient of variation and is stable for least one hour after blood collection. Intraindividual coefficient of variation is 2.6%. EA can now be easily measured in any clinical setting.


Assuntos
Agregação Eritrocítica , Sistemas Automatizados de Assistência Junto ao Leito , Viscosidade Sanguínea , Eritrócitos , Humanos , Cinética
8.
BMC Womens Health ; 22(1): 218, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35689277

RESUMO

BACKGROUND: The COVID-19 pandemic has affected the health and well-being of people worldwide, yet few studies have qualitatively examined its cumulative effects on ciswomen living with HIV (WLWH). We aimed to explore how the pandemic has impacted WLWH, including challenges related to HIV care, employment, finances, and childcare. We also investigated how HIV status and different psychosocial stressors affected their mental health. METHODS: We performed 25 semi-structured qualitative interviews with WLWH regarding the ways in which COVID-19 impacted their social determinants of health and physical well-being during the pandemic. 19 WLWH who received care at the University of Chicago Medicine (UCM) and 6 women who received care at Howard Brown Health, a federally qualified health center (FQHC) in Chicago, were interviewed remotely from June 2020 to April 2021. All interviews were audio recorded and transcribed. Interviews were thematically analyzed for commonalities regarding HIV-specific and general experiences of WLWH during the pandemic. RESULTS: The majority of participants reported COVID-19 impacted their HIV care, such as appointment cancellations and difficulties adhering to antiretroviral therapy. In addition to HIV care obstacles, almost all participants described perceived heightened vulnerability to or fear of COVID-19. The pandemic also affected the socioeconomic well-being of participants, with reported financial strains and employment disruptions. Some mothers took on additional childcare responsibilities, such as homeschooling. Increased mental health concerns and negative psychological effects from the social isolation associated with the pandemic were also experienced by most participants. CONCLUSIONS: We gained invaluable insight into how WLWH were challenged by and adapted to the COVID-19 pandemic, including its destabilizing effects on their HIV care and mental health. Women described how they undertook additional childcare responsibilities during the pandemic and how their HIV status compounded their concerns (e.g., perceived heightened vulnerability to COVID-19). Strategies to better support WLWH in maintaining their overall health throughout the pandemic include childcare assistance, access to affordable mental health services, support groups, and education from HIV care providers. These findings have significant implications for examining future health crises through the perspective of potential gender inequalities.


Assuntos
COVID-19 , Infecções por HIV , Chicago/epidemiologia , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Humanos , Pandemias , Estigma Social , Fatores Socioeconômicos
9.
AIDS Care ; 34(11): 1405-1412, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35473487

RESUMO

COVID-19 has disrupted routine medical care and increased psychosocial and economic stressors on a global scale, yet the full impact on people living with HIV (PLWH) and the HIV continuum of care remains unknown. As the pandemic continues to pose a significant threat to PLWH and their care, this research qualitatively aimed to elicit COVID-19-related challenges and perspectives of PLWH during the early phase of the pandemic and to identify lessons learned and impactful strategies for facilitating HIV care. We recruited 32 PLWH who receive care at a large academic medical center for semi-structured remote interviews to assess psychological/structural stressors experienced during the pandemic and to discern strategies for improving care. Most participants identified as Black (91%) and heterosexual (56%). Overall, PLWH reported exacerbated mental health stressors (e.g., anxiety, depression, substance use). Most participants cited no issues with antiretroviral therapy (ART) adherence or retention in care, yet five participants reported appointment cancellations or physician inaccessibility. Participants provided specific feedback for facilitating continued engagement in care during the pandemic, including telemedicine and education/patient empowerment. By seeking participant-provided solutions, this study centered on PLWH's experiences and emphasized proactive HIV care strategies for prioritizing patient empowerment and healthcare adaptability during a rapidly evolving pandemic.


Assuntos
COVID-19 , Infecções por HIV , Humanos , Pandemias , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Antirretrovirais/uso terapêutico , Participação do Paciente
10.
Clin Cancer Res ; 28(12): 2527-2535, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35275197

RESUMO

PURPOSE: In a post hoc analysis of the CATNON trial (NCT00626990), we explored whether adding temozolomide to radiotherapy improves outcome in patients with IDH1/2 wildtype (wt) anaplastic astrocytomas with molecular features of glioblastoma [redesignated as glioblastoma, isocitrate dehydrogenase-wildtype (IDH-wt) in the 2021 World Health Organization (WHO) classification of central nervous system tumors]. PATIENTS AND METHODS: From the randomized phase III CATNON study examining the addition of adjuvant and concurrent temozolomide to radiotherapy in anaplastic astrocytomas, we selected a subgroup of IDH1/2wt and H3F3Awt tumors with presence of TERT promoter mutations and/or EGFR amplifications and/or combined gain of chromosome 7 and loss of chromosome 10. Molecular abnormalities including MGMT promoter methylation status were determined by next-generation sequencing, DNA methylation profiling, and SNaPshot analysis. RESULTS: Of the 751 patients entered in the CATNON study, 670 had fully molecularly characterized tumors. A total of 159 of these tumors met the WHO 2021 molecular criteria for glioblastoma, IDH-wt. Of these patients, 47 received radiotherapy only and 112 received a combination of radiotherapy and temozolomide. There was no added effect of temozolomide on either overall survival [HR, 1.19; 95% confidence interval (CI), 0.82-1.71] or progression-free survival (HR, 0.87; 95% CI, 0.61-1.24). MGMT promoter methylation was prognostic for overall survival, but was not predictive for outcome to temozolomide treatment either with respect to overall survival or progression-free survival. CONCLUSIONS: In this cohort of patients with glioblastoma, IDH-wt temozolomide treatment did not add benefit beyond that observed from radiotherapy, regardless of MGMT promoter status. These findings require a new well-powered prospective clinical study to explore the efficacy of temozolomide treatment in this patient population.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioblastoma , Antineoplásicos Alquilantes , Astrocitoma/tratamento farmacológico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/radioterapia , Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Dacarbazina , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/radioterapia , Humanos , Isocitrato Desidrogenase/genética , Estudos Prospectivos , Temozolomida/uso terapêutico
11.
Clin Cancer Res ; 28(11): 2440-2448, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35294545

RESUMO

PURPOSE: Despite recent advances in the molecular characterization of gliomas, it remains unclear which patients benefit most from which second-line treatments. The TAVAREC trial was a randomized, open-label phase II trial assessing the benefit of the addition of the angiogenesis inhibitor bevacizumab to treatment with temozolomide in patients with a first enhancing recurrence of World Health Organization grade 2 or 3 glioma without 1p/19q codeletion. We evaluated the prognostic significance of genome-wide DNA methylation profiles and copy-number variations on the TAVAREC trial samples. EXPERIMENTAL DESIGN: Isocitrate dehydrogenase (IDH) mutation status was determined via Sanger sequencing and IHC. DNA methylation analysis was performed using the MethylationEPIC BeadChip (Illumina) from which 1p/19q codeletion, MGMT promoter methylation (MGMT-STP27), and homozygous deletion of CDKN2A/B were determined. DNA methylation classes were determined according to classifiers developed in Heidelberg and The Cancer Genome Atlas (TCGA; "Heidelberg" and "TCGA" classifier respectively). RESULTS: DNA methylation profiles of 122 samples were successfully determined. As expected, most samples were IDH-mutant (89/122) and MGMT promotor methylated (89/122). Methylation classes were prognostic for time to progression. However, Heidelberg methylation classes determined at time of diagnosis were no longer prognostic following enhancing recurrence of the tumor. In contrast, TCGA methylation classes of primary samples remained prognostic also following enhancing recurrence. Homozygous deletions in CDKN2A/B were found in 10 of 87 IDH-mutated samples and were prognostically unfavorable at recurrence. CONCLUSIONS: DNA methylome Heidelberg classification at time of diagnosis is no longer of prognostic value at the time of enhancing recurrence. CDKN2A/B deletion status was predictive of survival from progression of IDH-mutated tumors.


Assuntos
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/patologia , Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Glioma/patologia , Homozigoto , Humanos , Isocitrato Desidrogenase/genética , Imageamento por Ressonância Magnética , Mutação , Recidiva Local de Neoplasia/genética , Prognóstico , Deleção de Sequência
12.
Nat Metab ; 4(2): 213-224, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35177854

RESUMO

During starvation, mammalian brains can adapt their metabolism, switching from glucose to alternative peripheral fuel sources. In the Drosophila starved brain, memory formation is subject to adaptative plasticity, but whether this adaptive plasticity relies on metabolic adaptation remains unclear. Here we show that during starvation, neurons of the fly olfactory memory centre import and use ketone bodies (KBs) as an energy substrate to sustain aversive memory formation. We identify local providers within the brain, the cortex glia, that use their own lipid store to synthesize KBs before exporting them to neurons via monocarboxylate transporters. Finally, we show that the master energy sensor AMP-activated protein kinase regulates both lipid mobilization and KB export in cortex glia. Our data provide a general schema of the metabolic interactions within the brain to support memory when glucose is scarce.


Assuntos
Corpos Cetônicos , Inanição , Animais , Drosophila/metabolismo , Glucose/metabolismo , Corpos Cetônicos/metabolismo , Mamíferos/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Inanição/metabolismo
13.
Eur Radiol ; 32(5): 3436-3446, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34932165

RESUMO

OBJECTIVES: Cardiovascular magnetic resonance feature tracking (CMR-FT) is an emerging technique for assessing myocardial strain with valuable diagnostic and prognostic potential. However, the reproducibility of biventricular CMR-FT analysis in a large cardiovascular population has not been assessed. Also, evidence of confounders impacting reader reproducibility for CMR-FT in patients is unknown and currently limits the clinical implementation of this technique. METHODS: From a dual-center database of patients referred to CMR for suspected myocarditis, 125 patients were randomly selected to undergo biventricular CMR-FT analysis for 2-dimensional systolic and diastolic measures, with additional 3-dimensional analysis for the left ventricle. All image analysis was replicated by a single reader and by a second reader for intra- and inter-reader analysis (Circle Cardiovascular Imaging). Reliability was tested with intraclass correlation (ICC) tests, and the impact of imaging confounders on agreement was assessed through multivariable analysis. RESULTS: Left and right ventricular ejection fractions were reduced in 34% and 37% of the patients, respectively. Good to excellent reliability was shown for 2D (all ICC > 0.85) and 3D (all ICC > 0.70) peak strain and early diastolic strain rate for both ventricles in longitudinal orientation as well as circumferential orientations for the left ventricle. An increased slice number improved agreement while the presence of pericardial effusion compromised diastolic strain rate agreement, and arrhythmia compromised right ventricular agreement. CONCLUSION: In a large clinical cohort, we could show CMR-FT yields excellent inter-reader and intra-reader reproducibility. Multi-parametric CMR-FT of the right and left ventricles appears to be a robust tool in cardiovascular patients referred to CMR. CLINICALTRIALS: gov Identifier: NCT03470571, NCT04774549. Key Points • Cardiovascular magnetic resonance feature tracking (CMR-FT) is an emerging technique to measure myocardial strain in cardiovascular patients referred for CMR; however, the evaluation of its reproducibility in a large cohort has not yet been performed. • In a large clinical cohort, CMR-FT yields excellent inter-reader and intra-reader reproducibility for both left and right ventricular systolic and diastolic parameters. • Arrhythmia and pericardial effusion compromise agreement of select FT parameters, but poor ejection fraction does not.


Assuntos
Miocardite , Derrame Pericárdico , Humanos , Imagem Cinética por Ressonância Magnética/métodos , Miocardite/diagnóstico por imagem , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Função Ventricular Esquerda
14.
J Pediatr ; 239: 67-73.e3, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34437911

RESUMO

OBJECTIVE: To capture the early effects of the coronavirus disease 2019 (COVID-19) pandemic on pediatric clinical research. STUDY DESIGN: Pediatric clinical research networks from 20 countries and 50 of their affiliated research sites completed two surveys over one month from early May to early June 2020. Networks liaised with their affiliated sites and contributed to the interpretation of results through pan-European group discussions. Based on first detection dates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), countries formed 1 early detecting and 1 late detecting cluster. We tested the hypothesis that this clustering influenced clinical research. RESULTS: Research sites were first impacted by the pandemic in mid-March 2020 (March 16 ± 10 days, the same date as lockdown initiation; P = .99). From first impact up until early June, site initiation and feasibility analysis processes were affected for >50% of the sites. Staff were redirected to COVID-19 research for 44% of the sites, and 75.5% of sites were involved in pediatric COVID-19 research (only 6.3% reported COVID-19 cases in their other pediatric trials). Mitigation strategies were used differently between the early and late detecting country clusters and between countries with and without a pediatric COVID-19 research taskforce. Positive effects include the development of teleworking capacities. CONCLUSIONS: Through this collaborative effort from pediatric research networks, we found that pediatric trials were affected and conducted with a range of unequally applied mitigations across countries during the pandemic. The global impact might be greater than captured. In a context where clinical research is increasingly multinational, this report reveals the importance of collaboration between national networks.


Assuntos
COVID-19/epidemiologia , Ensaios Clínicos como Assunto/organização & administração , Canadá/epidemiologia , Criança , Europa (Continente)/epidemiologia , Humanos
15.
Nanoscale Horiz ; 6(7): 559-567, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-33999985

RESUMO

GaAs nanowires are regarded as promising building blocks of future optoelectronic devices. Despite progress, the growth of high optical quality GaAs nanowires is a standing challenge. Understanding the role of twin defects and nanowire facets on the optical emission and minority carrier lifetime of GaAs nanowires is key for the engineering of their optoelectronic properties. Here, we present new insights into the microstructural parameters controlling the optical properties of GaAs nanowires, grown via selective-area metal-organic vapor-phase epitaxy. We observe that these GaAs nanowires have a twinned zinc blende crystal structure with taper-free {110} side facets that result in an ultra-low surface recombination velocity of 3.5 × 104 cm s-1. This is an order of magnitude lower than that reported for defect-free GaAs nanowires grown by the vapor-liquid-solid technique. Using time-resolved photoluminescence and cathodoluminescence measurements, we untangle the local correlation between structural and optical properties demonstrating the superior role of the side facets in determining recombination rates over that played by twin defects. The low surface recombination velocity of these taper-free {110} side facets enable us to demonstrate, for the first time, low-temperature lasing from bare (unpassivated) GaAs nanowires, and also efficient room-temperature lasing after passivation with an AlGaAs shell.

16.
Lancet Oncol ; 22(6): 813-823, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34000245

RESUMO

BACKGROUND: The CATNON trial investigated the addition of concurrent, adjuvant, and both current and adjuvant temozolomide to radiotherapy in adults with newly diagnosed 1p/19q non-co-deleted anaplastic gliomas. The benefit of concurrent temozolomide chemotherapy and relevance of mutations in the IDH1 and IDH2 genes remain unclear. METHODS: This randomised, open-label, phase 3 study done in 137 institutions across Australia, Europe, and North America included patients aged 18 years or older with newly diagnosed 1p/19q non-co-deleted anaplastic gliomas and a WHO performance status of 0-2. Patients were randomly assigned (1:1:1:1) centrally using a minimisation technique to radiotherapy alone (59·4 Gy in 33 fractions; three-dimensional conformal radiotherapy or intensity-modulated radiotherapy), radiotherapy with concurrent oral temozolomide (75 mg/m2 per day), radiotherapy with adjuvant oral temozolomide (12 4-week cycles of 150-200 mg/m2 temozolomide given on days 1-5), or radiotherapy with both concurrent and adjuvant temozolomide. Patients were stratified by institution, WHO performance status score, age, 1p loss of heterozygosity, the presence of oligodendroglial elements on microscopy, and MGMT promoter methylation status. The primary endpoint was overall survival adjusted by stratification factors at randomisation in the intention-to-treat population. A second interim analysis requested by the independent data monitoring committee was planned when two-thirds of total required events were observed to test superiority or futility of concurrent temozolomide. This study is registered with ClinicalTrials.gov, NCT00626990. FINDINGS: Between Dec 4, 2007, and Sept 11, 2015, 751 patients were randomly assigned (189 to radiotherapy alone, 188 to radiotherapy with concurrent temozolomide, 186 to radiotherapy and adjuvant temozolomide, and 188 to radiotherapy with concurrent and adjuvant temozolomide). Median follow-up was 55·7 months (IQR 41·0-77·3). The second interim analysis declared futility of concurrent temozolomide (median overall survival was 66·9 months [95% CI 45·7-82·3] with concurrent temozolomide vs 60·4 months [45·7-71·5] without concurrent temozolomide; hazard ratio [HR] 0·97 [99·1% CI 0·73-1·28], p=0·76). By contrast, adjuvant temozolomide improved overall survival compared with no adjuvant temozolomide (median overall survival 82·3 months [95% CI 67·2-116·6] vs 46·9 months [37·9-56·9]; HR 0·64 [95% CI 0·52-0·79], p<0·0001). The most frequent grade 3 and 4 toxicities were haematological, occurring in no patients in the radiotherapy only group, 16 (9%) of 185 patients in the concurrent temozolomide group, and 55 (15%) of 368 patients in both groups with adjuvant temozolomide. No treatment-related deaths were reported. INTERPRETATION: Adjuvant temozolomide chemotherapy, but not concurrent temozolomide chemotherapy, was associated with a survival benefit in patients with 1p/19q non-co-deleted anaplastic glioma. Clinical benefit was dependent on IDH1 and IDH2 mutational status. FUNDING: Merck Sharpe & Dohme.


Assuntos
Glioma/tratamento farmacológico , Isocitrato Desidrogenase/genética , Temozolomida/administração & dosagem , Adolescente , Adulto , Idoso , Austrália , Quimioterapia Adjuvante , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 19/genética , Terapia Combinada , Dacarbazina/administração & dosagem , Dacarbazina/efeitos adversos , Europa (Continente) , Feminino , Glioma/genética , Glioma/patologia , Glioma/radioterapia , Humanos , Perda de Heterozigosidade/genética , Masculino , Pessoa de Meia-Idade , América do Norte , Radioterapia Conformacional , Adulto Jovem
17.
Neuro Oncol ; 23(9): 1547-1559, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33914057

RESUMO

BACKGROUND: Survival in patients with IDH1/2-mutant (mt) anaplastic astrocytomas is highly variable. We have used the prospective phase 3 CATNON trial to identify molecular factors related to outcome in IDH1/2mt anaplastic astrocytoma patients. METHODS: The CATNON trial randomized 751 adult patients with newly diagnosed 1p/19q non-codeleted anaplastic glioma to 59.4 Gy radiotherapy +/- concurrent and/or adjuvant temozolomide. The presence of necrosis and/or microvascular proliferation was scored at central pathology review. Infinium MethylationEPIC BeadChip arrays were used for genome-wide DNA methylation analysis and the determination of copy number variations (CNV). Two DNA methylation-based tumor classifiers were used for risk stratification. Next-generation sequencing (NGS) was performed using 1 of the 2 glioma-tailored NGS panels. The primary endpoint was overall survival measured from the date of randomization. RESULTS: Full analysis (genome-wide DNA methylation and NGS) was successfully performed on 654 tumors. Of these, 432 tumors were IDH1/2mt anaplastic astrocytomas. Both epigenetic classifiers identified poor prognosis patients that partially overlapped. A predictive prognostic Cox proportional hazard model identified that independent prognostic factors for IDH1/2mt anaplastic astrocytoma patients included; age, mini-mental state examination score, treatment with concurrent and/or adjuvant temozolomide, the epigenetic classifiers, PDGFRA amplification, CDKN2A/B homozygous deletion, PI3K mutations, and total CNV load. Independent recursive partitioning analysis highlights the importance of these factors for patient prognostication. CONCLUSION: Both clinical and molecular factors identify IDH1/2mt anaplastic astrocytoma patients with worse outcome. These results will further refine the current WHO criteria for glioma classification.


Assuntos
Neoplasias Encefálicas , Glioma , Adulto , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Cromossomos Humanos Par 1 , Variações do Número de Cópias de DNA , Metilação de DNA , Glioma/genética , Glioma/terapia , Homozigoto , Humanos , Isocitrato Desidrogenase/genética , Mutação , Prognóstico , Estudos Prospectivos , Deleção de Sequência
18.
Acta Neuropathol ; 141(6): 945-957, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33740099

RESUMO

Somatic mutations in the isocitrate dehydrogenase genes IDH1 and IDH2 occur at high frequency in several tumour types. Even though these mutations are confined to distinct hotspots, we show that gliomas are the only tumour type with an exceptionally high percentage of IDH1R132H mutations. Patients harbouring IDH1R132H mutated tumours have lower levels of genome-wide DNA-methylation, and an associated increased gene expression, compared to tumours with other IDH1/2 mutations ("non-R132H IDH1/2 mutations"). This reduced methylation is seen in multiple tumour types and thus appears independent of the site of origin. For 1p/19q non-codeleted glioma (astrocytoma) patients, we show that this difference is clinically relevant: in samples of the randomised phase III CATNON trial, patients harbouring tumours with IDH mutations other than IDH1R132H have a better outcome (hazard ratio 0.41, 95% CI [0.24, 0.71], p = 0.0013). Such non-R132H IDH1/2-mutated tumours also had a significantly lower proportion of tumours assigned to prognostically poor DNA-methylation classes (p < 0.001). IDH mutation-type was independent in a multivariable model containing known clinical and molecular prognostic factors. To confirm these observations, we validated the prognostic effect of IDH mutation type on a large independent dataset. The observation that non-R132H IDH1/2-mutated astrocytomas have a more favourable prognosis than their IDH1R132H mutated counterpart indicates that not all IDH-mutations are identical. This difference is clinically relevant and should be taken into account for patient prognostication.


Assuntos
Astrocitoma/diagnóstico , Astrocitoma/genética , Neoplasias Encefálicas/genética , Metilação de DNA/genética , Isocitrato Desidrogenase/genética , Mutação , Neoplasias Encefálicas/diagnóstico , Humanos , Prognóstico , Taxa de Sobrevida
19.
Nutrients ; 12(10)2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32998302

RESUMO

Food choices affect the isotopic composition of the body with each food item leaving its distinct isotopic imprint. The common view is that the natural abundance of the stable isotopes of nitrogen (expressed as δ15N) is higher in animals than in plants that constitute our contemporary diets. Higher δ15N is thus increasingly viewed as a biomarker for meat and fish intake. Here we show that organic compared to conventional farming increases plant δ15N to an extent that can appreciably impact the performance of δ15N as a biomarker. The error that can arise when organic plants are consumed was modelled for the entire range of proportions of plant versus animal protein intake, and accounting for various intakes of organic and conventionally grown crops. This mass balance model allows the interpretation of differences in δ15N in light of organic food consumption. Our approach shows that the relationship between δ15N and meat and fish intake is highly contextual and susceptible to variation at the population, community or group level. We recommend that fertilization practices and organic plant consumption must not be overlooked when using δ15N as a biomarker for meat and fish intake or to assess compliance to nutritional interventions.


Assuntos
Proteínas Animais da Dieta/análise , Ingestão de Alimentos/fisiologia , Alimentos Orgânicos/análise , Isótopos de Nitrogênio/sangue , Proteínas de Vegetais Comestíveis/análise , Biomarcadores/sangue , Humanos , Carne/análise , Agricultura Orgânica/métodos , Plantas Comestíveis/química , Alimentos Marinhos/análise
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