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1.
Can J Neurol Sci ; 50(3): 365-372, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35581937

RESUMO

Traumatic brain injury (TBI) was first proposed as a potential risk factor for developing a glioma in the 1800s, and conditions for establishing a causal relationship between brain injury and gliomas have since been proposed. Given the medical and legal ramifications, the current literature was reviewed to better understand this possible association. Articles that examined the relationship between TBI and glioma formation in adults and were published in English between 1978 and 2022 were reviewed. There were 19 case reports of 25 patients and 16 observational studies. The case reports describe glioma formation at the precise site of prior brain injury in continuity with traumatic scar; the observational studies report conflicting findings, but they largely demonstrate no association. Most of the observational studies are limited by their retrospective nature, but we identified one prospective cohort study which found a positive association. Altogether, we suggest that glioma formation after TBI is a rare occurrence that warrants further study.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas , Glioma , Humanos , Adulto , Estudos Retrospectivos , Estudos Prospectivos , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/epidemiologia , Glioma/complicações
2.
Nano Lett ; 21(22): 9805-9815, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34516144

RESUMO

The blood-brain barrier (BBB) is highly selective and acts as the interface between the central nervous system and circulation. While the BBB is critical for maintaining brain homeostasis, it represents a formidable challenge for drug delivery. Here we synthesized gold nanoparticles (AuNPs) for targeting the tight junction specifically and demonstrated that transcranial picosecond laser stimulation of these AuNPs post intravenous injection increases the BBB permeability. The BBB permeability change can be graded by laser intensity, is entirely reversible, and involves increased paracellular diffusion. BBB modulation does not lead to significant disruption in the spontaneous vasomotion or the structure of the neurovascular unit. This strategy allows the entry of immunoglobulins and viral gene therapy vectors, as well as cargo-laden liposomes. We anticipate this nanotechnology to be useful for tissue regions that are accessible to light or fiberoptic application and to open new avenues for drug screening and therapeutic interventions in the central nervous system.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Transporte Biológico , Barreira Hematoencefálica , Ouro/química , Lasers
3.
Magn Reson Med ; 86(4): 1818-1828, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33977579

RESUMO

PURPOSE: 1 H MRS provides a noninvasive tool for identifying mutations in isocitrate dehydrogenase (IDH). Quantification of the prominent 2-hydroxyglutarate (2HG) resonance at 2.25 ppm is often confounded by the lipid resonance at the same frequency in tumors with elevated lipids. We propose a new spectral fitting approach to separate these overlapped signals, therefore, improving 2HG evaluation. METHODS: TE 97 ms PRESS was acquired at 3T from 42 glioma patients. New lipid basis sets were created, in which the small lipid 2.25-ppm signal strength was preset with reference to the lipid signal at 0.9 ppm, incorporating published fat relaxation data. LCModel fitting using the new lipid bases (Fitting method 2) was conducted along with fitting using the LCModel built-in lipid basis set (Fitting method 1), in which the lipid 2.25-ppm signal is assessed with reference to the lipid 1.3-ppm signal. In-house basis spectra of low-molecular-weight metabolites were used in both fitting methods. RESULTS: Fitting method 2 showed marked improvement in identifying IDH mutational status compared with Fitting method 1. 2HG estimates from Fitting method 2 were overall smaller than those from Fitting method 1, which was because of differential assignment of the signal at 2.25 ppm to lipids. In receiver operating characteristic analysis, Fitting method 2 provided a complete distinction between IDH mutation and wild-type whereas Fitting method 1 did not. CONCLUSION: The data suggest that 1 H MR spectral fitting using the new lipid basis set provides a robust fitting strategy that improves 2HG evaluation in brain tumors with elevated lipids.


Assuntos
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Glutaratos , Humanos , Lipídeos , Espectroscopia de Ressonância Magnética
4.
Cancer ; 126(12): 2821-2828, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32154928

RESUMO

BACKGROUND: Targeting vascular endothelial growth factor (VEGF) alone does not improve overall survival (OS) in recurrent glioblastoma (rGBM). The angiopoiein (Ang)-TIE2 system may play a role in tumor survival under VEGF inhibition. We conducted a phase 2, double-blinded, placebo-controlled trial of bevacizumab plus trebananib (a novel Fc fusion protein that sequesters Ang1/Ang2) over bevacizumab alone in rGBM. METHODS: Patients ≥18 years of age with a Karnofsky performance status ≥70 and GBM or variants in first or second relapse were randomized to bevacizumab 10 mg/kg every 2 weeks plus trebananib 15 mg/kg every week or bevacizumab plus placebo. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: After an initial 6-patient lead-in cohort confirmed the safety of combining bevacizumab and trebananib, 115 eligible patients were randomized to the control (n = 58) or experimental treatment (n = 57). In the control arm, 6-month PFS was 41.1%, median survival time was 11.5 months (95% CI, 8.4-14.2 months), median PFS was 4.8 months (95% CI, 3.8-7.1 months), and radiographic response (RR) was 5.9%. In the experimental arm, 6-month PFS was 22.6%, median survival time was 7.5 months (95% CI, 6.8-10.1 months), median PFS was 4.2 months (95% CI, 3.7-5.6 months), and RR was 4.2%. The rate of severe toxicities was not significantly different between arms. CONCLUSION: The combination of bevacizumab and trebananib was well tolerated but did not significantly improve 6-month PFS rate, PFS, or OS for patients with rGBM over bevacizumab alone. The shorter PFS in the experimental arm with a hazard ratio of 1.51 (P = .04) suggests that the addition of trebananib to bevacizumab is detrimental.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Glioblastoma/tratamento farmacológico , Gliossarcoma/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/administração & dosagem , Método Duplo-Cego , Feminino , Glioblastoma/mortalidade , Glioblastoma/patologia , Gliossarcoma/mortalidade , Gliossarcoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/farmacocinética , Resultado do Tratamento
5.
Magn Reson Med ; 84(3): 1152-1160, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32003035

RESUMO

PURPOSE: To generate a preclinical model of isocitrate dehydrogenase (IDH) mutant gliomas from glioma patients and design a MRS method to test the compatibility of 2-hydroxyglutarate (2HG) production between the preclinical model and patients. METHODS: Five patient-derived xenograft (PDX) mice were generated from two glioma patients with IDH1 R132H mutation. A PRESS sequence was tailored at 9.4 T, with computer simulation and phantom analyses, for improving 2HG detection in mice. 2HG and other metabolites in the PDX mice were measured using the optimized MRS at 9.4 T and compared with 3 T MRS measurements of the metabolites in the parental-tumor patients. Spectral fitting was performed with LCModel using in-house basis spectra. Metabolite levels were quantified with reference to water. RESULTS: The PRESS TE was optimized to be 96 ms, at which the 2HG 2.25 ppm signal was narrow and inverted, thereby leading to unequivocal separation of the 2HG resonance from adjacent signals from other metabolites. The optimized MRS provided precise detection of 2HG in mice compared to short-TE MRS at 9.4 T. The 2HG estimates in PDX mice were in excellent agreement with the 2HG measurements in the patients. CONCLUSION: The similarity of 2HG production between PDX models and parental-tumor patients indicates that PDX tumors retain the parental IDH metabolic fingerprint and can serve as a preclinical model for improving our understanding of the IDH-mutation associated metabolic reprogramming.


Assuntos
Neoplasias Encefálicas , Glioma , Animais , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Simulação por Computador , Glioma/diagnóstico por imagem , Glioma/genética , Glutaratos , Humanos , Isocitrato Desidrogenase/genética , Espectroscopia de Ressonância Magnética , Camundongos , Transplante de Neoplasias
6.
Magn Reson Med ; 81(2): 795-802, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30277274

RESUMO

PURPOSE: To develop 3D high-resolution imaging of 2-hydroxyglutarate (2HG) at 3T in vivo. METHODS: Echo-planar spectroscopic imaging with dual-readout alternated-gradients (DRAG-EPSI), which was recently reported for 2D imaging of 2HG at 7T, was tested for 3D imaging of 2HG at 3T. The frequency drifts and acoustic noise induced by DRAG-EPSI were investigated in comparison with conventional EPSI. Four patients with IDH-mutant gliomas were enrolled for 3D imaging of 2HG and other metabolites. A previously reported 2HG-tailored TE 97-ms PRESS sequence preceded the DRAG-EPSI readout gradients. Unsuppressed water, acquired with EPSI, was used as reference for multi-channel combination, eddy-current compensation, and metabolite quantification. Spectral fitting was conducted with the LCModel using in-house basis sets. RESULTS: With gradient strength of 4 mT/m and slew rate of 20 mT/m/ms, DRAG-EPSI produced frequency drifts smaller by 5.5-fold and acoustic noise lower by 25 dB compared to conventional EPSI. In a 19-min scan, 3D DRAG-EPSI provided images of 2HG with precision (CRLB <10%) at a resolution of 10 × 10 × 10 mm3 for a field of view of 240 × 180 × 80 mm3 . 2HG was estimated to be 5 mM in a pre-treatment patient. In 3 post-surgery patients, 2HG estimates were 3-6 mM, and the 2HG distribution was different from the water-T2 image pattern or highly concentrated in the post-contrast enhancing region. CONCLUSION: Together with 2HG-optimized PRESS, DRAG-EPSI provides an effective tool for reliable 3D high-resolution imaging of 2HG at 3T in vivo.


Assuntos
Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Imagem Ecoplanar , Glioma/diagnóstico por imagem , Glutaratos/análise , Imageamento Tridimensional , Oligodendroglioma/diagnóstico por imagem , Acústica , Adulto , Algoritmos , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Meios de Contraste , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Mutação , Imagens de Fantasmas , Imagem Corporal Total
7.
Magn Reson Med ; 79(4): 1851-1861, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28833542

RESUMO

PURPOSE: To develop echo-planar spectroscopic imaging (EPSI) with large spectral width and accomplish high-resolution imaging of 2-hydroxyglutarate (2HG) at 7 T. METHODS: We designed a new EPSI readout scheme at 7 T. Data were recorded with dual-readout alternated gradients and combined according to the gradient polarity. Following validation of its performance in phantoms, the new readout scheme, together with previously reported 2HG-optimized magnetic resonance spectroscopy (point-resolved spectroscopy echo time of 78 ms), was used for time-efficient and high-resolution imaging of 2HG and other metabolites in five glioma patients before treatment. Unsuppressed water, acquired with EPSI, was used as reference for multichannel combination, eddy-current compensation, and metabolite quantification. Spectral fitting was conducted with the LCModel using in-house calculated basis sets. RESULTS: Using a readout gradient strength of 9.5 mT/m and slew rate of 90 mT/m/ms, dual-readout alternated gradients EPSI permitted 1638-Hz spectral width with 6 × 6 mm2 in-plane resolution at 7 T. Phantom data indicated that dual-readout alternated gradients EPSI provides proper metabolite signals and induces much less frequency drifts than conventional EPSI. For a spatial resolution of 0.5 mL, 2HG was detected in tumors with precision (Cramer-Rao lower bound < 10%). The 2HG was estimated to be 2.3 to 3.3 mM in tumors of three patients with biopsy-proven isocitrate dehydrogenase (IDH) mutant gliomas. The 2HG was undetectable in an IDH wild-type glioblastoma. For a radiographically suggested glioma, the estimated 2HG of 2.3 ± 0.2 mM (Cramer-Rao lower bound < 10%) indicated that the lesion may be an IDH mutant glioma. CONCLUSIONS: The data indicated that the dual-readout alternated gradients EPSI can provide reliable high-resolution imaging of 2HG in glioma patients at 7 T in vivo. Magn Reson Med 79:1851-1861, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Imagem Ecoplanar/métodos , Glioma/diagnóstico por imagem , Glutaratos/química , Espectroscopia de Ressonância Magnética/métodos , Adulto , Biomarcadores , Neoplasias Encefálicas/genética , Feminino , Glioma/genética , Humanos , Processamento de Imagem Assistida por Computador/métodos , Isocitrato Desidrogenase/genética , Masculino , Pessoa de Meia-Idade , Mutação , Oligodendroglioma/diagnóstico por imagem , Oligodendroglioma/genética , Imagens de Fantasmas
8.
J Neurooncol ; 139(3): 731-738, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29882044

RESUMO

PURPOSE: Pseudoprogression is often indistinguishable from true tumor progression on conventional 2-dimensional (2D) MRI in glioblastoma multiforme (GBM) patients. The aim of this study was to determine the association between post-gadolinium 3-dimensional (3D) characteristics and clinical state in GBM patients. METHODS: Standardized 3D brain MRI studies were performed, and contrast enhancing portions of each tumor were segmented and analyzed, blinded to clinical state, using principal component analysis (PCA), medial axis transformation (MAT), and coverage analysis. Associations between the 3D characteristics of the post-gadolinium enhanced regions and the clinical status of patients were performed. RESULTS: A total of 15 GBM patients [male: 11 (73%); median age (range): 62 years (36-72)] with a median disease duration of 6 months (range 2-24 months) were studied cross-sectionally with 6 (40%) patients identified with tumor progression. Post-gadolinium features corresponding to the group with progressive disease exhibited a more spherical and symmetric shape relative to their stable counterparts (p = 0.005). The predictive value of a more uniformly full post-gadolinium enhanced shell to clinical progression was determined with a sensitivity of 66.7% (95% CI 29.9-92.5), specificity of 100% (54.1-100), and PPV of 100% (p = 0.028, 2-tailed Fisher's exact test). There did not appear to be an association between the thickness of the contrast enhanced shell to clinical state. CONCLUSIONS: The application of 3D technology with post-gadolinium imaging data may inform healthcare providers with new insights into disease states based on spatial, surface, and structural patterns.


Assuntos
Neoplasias Encefálicas/patologia , Quimiorradioterapia/métodos , Gadolínio/metabolismo , Glioblastoma/patologia , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/terapia , Estudos de Coortes , Progressão da Doença , Feminino , Seguimentos , Glioblastoma/metabolismo , Glioblastoma/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
9.
Magn Reson Med ; 77(3): 936-944, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26991680

RESUMO

PURPOSE: To test the efficacy of 7T MRS for in vivo detection of 2-hydroxyglutarate (2HG) in brain tumors. METHODS: The subecho times of point-resolved spectroscopy (PRESS) were optimized at 7T with density-matrix simulations and phantom validation to improve the 2HG signal selectivity with respect to the neighboring resonances of γ-aminobutyric acid (GABA), glutamate (Glu), and glutamine (Gln). MRS data were acquired from 12 subjects with gliomas in vivo and analyzed with LCModel using calculated basis spectra. Metabolite levels were quantified using unsuppressed short echo time (TE) water as a reference. RESULTS: The PRESS TE was optimized as TE = 78 ms (TE1 = 58 ms and TE2 = 20 ms), at which the 2HG 2.25 ppm resonance appeared as a temporally maximum inverted narrow peak and the GABA, Glu, and Gln resonances between 2.2 and 2.5 ppm were all positive peaks. The PRESS TE = 78 ms method offered improved discrimination of 2HG from Glu, Gln, and GABA when compared with short-TE MRS. 2HG was detected in all patients enrolled in the study, the estimated 2HG concentrations ranging from 1.0 to 6.2 mM, with percentage standard deviation of 2%-7%. CONCLUSION: Data indicate that the optimized MRS provides good selectivity of 2HG from other metabolite signals and may confer reliable in vivo detection of 2HG at relatively low concentrations. Magn Reson Med 77:936-944, 2017. © 2016 International Society for Magnetic Resonance in Medicine.


Assuntos
Algoritmos , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Glutaratos/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Processamento de Sinais Assistido por Computador , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
Magn Reson Med ; 78(1): 40-48, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27454352

RESUMO

PURPOSE: To test the efficacy of triple-refocusing MR spectroscopy (MRS) for improved detection of 2-hydroxyglutarate (2HG) in brain tumors at 3T in vivo. METHODS: The triple-refocusing sequence parameters were tailored at 3T, with density-matrix simulations and phantom validation, for enhancing the 2HG 2.25-ppm signal selectivity with respect to the adjacent resonances of glutamate (Glu), glutamine (Gln), and gamma-aminobutyric acid (GABA). In vivo MRS data were acquired from 15 glioma patients and analyzed with LCModel using calculated basis spectra. Metabolites were quantified with reference to water. RESULTS: A triple-refocusing sequence (echo time = 137 ms) was obtained for 2HG detection. The 2HG 2.25-ppm signal was large and narrow while the Glu and Gln signals between 2.2 and 2.3 ppm were minimal. The optimized triple refocusing offered improved separation of 2HG from Glu, Gln and GABA when compared with published MRS methods. 2HG was detected in all 15 patients, the estimated 2HG concentrations ranging from 2.4 to 15.0 mM, with Cramer-Rao lower bounds of 2%-11%. The 2HG estimates did not show significant correlation with total choline. CONCLUSION: The optimized triple refocusing provides excellent 2HG signal discrimination from adjacent resonances and may confer reliable in vivo measurement of 2HG at relatively low concentrations. Magn Reson Med 78:40-48, 2017. © 2016 International Society for Magnetic Resonance in Medicine.


Assuntos
Algoritmos , Biomarcadores Tumorais/análise , Neoplasias Encefálicas/química , Neoplasias Encefálicas/diagnóstico , Glutaratos/análise , Espectroscopia de Ressonância Magnética/métodos , Processamento de Sinais Assistido por Computador , Adulto , Idoso , Neoplasias Encefálicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
NMR Biomed ; 30(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28548710

RESUMO

Glycine (Gly) has been implicated in several neurological disorders, including malignant brain tumors. The precise measurement of Gly is challenging largely as a result of the spectral overlap with myo-inositol (mI). We report a new triple-refocusing sequence for the reliable co-detection of Gly and mI at 3 T and for the evaluation of Gly in healthy and tumorous brain. The sequence parameters were optimized with density-matrix simulations and phantom validation. With a total TE of 134 ms, the sequence gave complete suppression of the mI signal between 3.5 and 3.6 ppm and, consequently, well-defined Gly (3.55 ppm) and mI (3.64 ppm) peaks. In vivo 1 H magnetic resonance spectroscopy (MRS) data were acquired from the gray matter (GM)-dominant medial occipital and white matter (WM)-dominant left parietal regions in six healthy subjects, and analyzed with LCModel using in-house-calculated basis spectra. Tissue segmentation was performed to obtain the GM and WM contents within the MRS voxels. Metabolites were quantified with reference to GM-rich medial occipital total creatine at 8 mM. The Gly and mI concentrations were estimated to be 0.63 ± 0.05 and 8.6 ± 0.6 mM for the medial occipital and 0.34 ± 0.05 and 5.3 ± 0.8 mM for the left parietal regions, respectively. From linear regression of the metabolite estimates versus fractional GM content, the concentration ratios between pure GM and pure WM were estimated to be 2.6 and 2.1 for Gly and mI, respectively. Clinical application of the optimized sequence was performed in four subjects with brain tumor. The Gly levels in tumors were higher than those of healthy brain. Gly elevation was more extensive in a post-contrast enhancing region than in a non-enhancing region. The data indicate that the optimized triple-refocusing sequence may provide reliable co-detection of Gly and mI, and alterations of Gly in brain tumors can be precisely evaluated.


Assuntos
Neoplasias Encefálicas/metabolismo , Encéfalo/metabolismo , Glicina/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Adulto , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Feminino , Substância Cinzenta/metabolismo , Humanos , Inositol/metabolismo , Modelos Lineares , Masculino , Imagens de Fantasmas
12.
J Neurooncol ; 133(1): 183-192, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28421459

RESUMO

According to the recently updated World Health Organization (WHO) classification (2016), grade II-III astrocytomas are divided into IDH-wildtype and IDH-mutant groups, the latter being significantly less aggressive in terms of both progression-free and total survival. We identified a small cohort of WHO grade II-III astrocytomas that harbored the IDH1 R132H mutation, as confirmed by both immunohistochemistry and molecular sequence analysis, which nonetheless had unexpectedly rapid recurrence and subsequent progression to glioblastoma. Among these four cases, the mean time to recurrence as glioblastoma was only 16 months and the mean total survival among the three patients who have died during the follow-up was only 31 months. We hypothesized that these tumors had other, unfavorable genetic or epigenetic alterations that negated the favorable effect of the IDH mutation. We applied genome-wide profiling with a methylation array (Illumina Infinium Human Methylation 450k) to screen for genetic and epigenetic alterations in these tumors. As expected, the methylation profiles of all four tumors were found to match most closely with IDH-mutant astrocytomas. Compared with a control group of four indolent, age-similar WHO grade II-III astrocytomas, the tumors showed markedly increased levels of overall copy number changes, but no consistent specific genetic alterations were seen across all of the tumors. While most IDH-mutant WHO grade II-III astrocytomas are relatively indolent, a subset may rapidly recur and progress to glioblastoma. The precise underlying cause of the increased aggressiveness in these gliomas remains unknown, although it may be associated with increased genomic instability.


Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Glioblastoma/genética , Isocitrato Desidrogenase/genética , Mutação , Adulto , Astrocitoma/mortalidade , Astrocitoma/patologia , Astrocitoma/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Variações do Número de Cópias de DNA , Metilação de DNA , Progressão da Doença , Feminino , Seguimentos , Estudo de Associação Genômica Ampla , Glioblastoma/mortalidade , Glioblastoma/patologia , Glioblastoma/fisiopatologia , Humanos , Imuno-Histoquímica , Isocitrato Desidrogenase/metabolismo , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/mortalidade , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo
13.
Proc Natl Acad Sci U S A ; 111(12): 4542-7, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24616497

RESUMO

Glioblastoma multiforme (GBM), which account for more than 50% of all gliomas, is among the deadliest of all human cancers. Given the dismal prognosis of GBM, it would be advantageous to identify early biomarkers of a response to therapy to avoid continuing ineffective treatments and to initiate other therapeutic strategies. The present in vivo longitudinal study in an orthotopic mouse model demonstrates quantitative assessment of early treatment response during short-term chemotherapy with temozolomide (TMZ) by amide proton transfer (APT) imaging. In a GBM line, only one course of TMZ (3 d exposure and 4 d rest) at a dose of 80 mg/kg resulted in substantial reduction in APT signal compared with untreated control animals, in which the APT signal continued to increase. Although there were no detectable differences in tumor volume, cell density, or apoptosis rate between groups, levels of Ki67 (index of cell proliferation) were substantially reduced in treated tumors. In another TMZ-resistant GBM line, the APT signal and levels of Ki67 increased despite the same course of TMZ treatment. As metabolite changes are known to occur early in the time course of chemotherapy and precede morphologic changes, these results suggest that the APT signal in glioma may be a useful functional biomarker of treatment response or degree of tumor progression. Thus, APT imaging may serve as a sensitive biomarker of early treatment response and could potentially replace invasive biopsies to provide a definitive diagnosis. This would have a major impact on the clinical management of patients with glioma.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/análogos & derivados , Glioblastoma/tratamento farmacológico , Animais , Dacarbazina/uso terapêutico , Humanos , Camundongos , Camundongos SCID , Prognóstico , Temozolomida , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
14.
J Neurooncol ; 130(3): 571-579, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27826680

RESUMO

Antiangiogenic therapies for malignant gliomas often result in transient response, and recurrent disease is characterized by adoption of invasive and hypoxic phenotype. The notch signaling pathway is activated in gliomas, and augments cell migration and hypoxic response. Here we report a clinical study of the combination of bevacizumab and RO4929097, an inhibitor of the notch signaling cascade. A phase I clinical trial was conducted through the Adult Brain Tumor Consortium in subjects with recurrent malignant glioma. Primary objectives were to assess safety and to define the maximum tolerated dose of RO4929097 in combination with bevacizumab. Secondary objectives were to determine overall survival, progression free survival, radiographic response, pharmacokinetic evaluation, and tissue biomarker analysis. Thirteen subjects were enrolled. Of the three subjects treated with the highest dose of RO4929097, one grade 3 toxicity and one grade 2 toxicity were observed. Definitive maximum tolerated dose of RO4929097 in combination with bevacizumab was not identified due to manufacturer's decision to halt drug production. 2 of 12 evaluable subjects demonstrated radiographic response; one subject experienced CR and the second PR. The median overall survival was 10.9 months with a median progression-free survival of 3.7 months. Two subjects remained free of disease progression at 6 months from treatment initiation. PK evaluation did not identify clinically significant drug-drug interactions. All analyzed tissue specimens revealed activation of notch signaling. Combination of RO4929097 and bevacizumab was well-tolerated. Given the compelling scientific rationale, additional studies of antiangiogenic and notch signaling inhibitors should be considered.


Assuntos
Antineoplásicos/uso terapêutico , Benzazepinas/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Adulto , Neoplasias Encefálicas/mortalidade , Feminino , Glioma/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
15.
J Neurooncol ; 119(2): 413-20, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24965340

RESUMO

A phase I study was conducted to evaluate the dose-limiting toxicities (DLTs) and to determine the maximum tolerated dose (MTD)/recommended phase II dose of bendamustine with concurrent whole brain radiation (WBR) in patients with brain metastases (BM) from solid tumors. Four doses of intravenous weekly bendamustine were administered with 3 weeks of WBR at three dose levels (60, 80, and 100 mg/m(2)) according to a standard 3 + 3 phase I design. A total of 12 patients with solid tumor BM were enrolled in the study (six with non-small cell lung cancer, four with melanoma, one with breast cancer, and one with neuroendocrine carcinoma). The first two dose levels had three patients each, and the third dose level had six total patients. Plasma pharmacokinetic studies of bendamustine demonstrated no significant differences from pharmacokinetic characteristics of bendamustine in other studies. No DLTs were noted at any dose levels, and no grade 4 toxicities occurred. The MTD of weekly bendamustine with concurrent WBR was 100 mg/m(2). The majority of trial patients died from progressive systemic disease rather than their brain disease. The combination of weekly bendamustine with concurrent WBR was acceptably tolerated. The efficacy of this combination may be evaluated in a phase II trial with stratification by histologies.


Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Compostos de Mostarda Nitrogenada/administração & dosagem , Adulto , Idoso , Antineoplásicos Alquilantes/efeitos adversos , Antineoplásicos Alquilantes/farmacocinética , Cloridrato de Bendamustina , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Carcinoma Neuroendócrino/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Estudos de Coortes , Terapia Combinada , Esquema de Medicação , Feminino , Seguimentos , Humanos , Masculino , Dose Máxima Tolerável , Melanoma/patologia , Pessoa de Meia-Idade , Compostos de Mostarda Nitrogenada/efeitos adversos , Compostos de Mostarda Nitrogenada/farmacocinética , Análise de Sobrevida , Resultado do Tratamento
16.
Cancer Causes Control ; 24(5): 1025-31, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23456313

RESUMO

INTRODUCTION: Increased height and greater adiposity have been linked to an increased risk of many cancer types, though few large studies have examined these associations in glioma. We examined body weight and height as potential risk factors for glioma in a large US-based case-control study. METHODS: The analysis included 1,111 glioma cases and 1,096 community controls. In a structured interview, participants reported their height and weight at 21 years of age, lowest and highest weight in adulthood, and weight 1-5 years in the past. RESULTS: Being underweight at age 21 (BMI < 18.5 kg/m(2)) was inversely associated with the risk of glioma development. This protective association was observed in both men and women, but reached statistical significance in women only (multivariate OR 0.68; 95 % CI 0.48, 0.96). When BMI at age 21 was assessed as a continuous variate, a small but significant increase in risk was observed per unit increase in kg/m(2) (OR 1.04; 95 % CI 1.02, 1.07). Adult height, recent body weight, and weight change in adulthood were not associated with glioma risk. All results were similar among never smokers and were consistent after stratifying by glioma subtype. CONCLUSION: The present data suggest that a low body weight in early adulthood is associated with a reduced risk of glioma later in life. Results are consistent with previous studies in showing no material association of glioma risk with usual adult body weight. The present study does not support any association of adult stature with glioma risk.


Assuntos
Estatura , Peso Corporal , Neoplasias do Sistema Nervoso Central/epidemiologia , Glioma/epidemiologia , Adulto , Idoso , Antropometria , Estudos de Casos e Controles , Neoplasias do Sistema Nervoso Central/etiologia , Feminino , Glioma/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco
17.
Eur J Epidemiol ; 28(9): 753-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23681776

RESUMO

Exposure to common infections in early life may stimulate immune development and reduce the risk for developing cancer. Birth order and family size are proxies for the timing of exposure to childhood infections with several studies showing a reduced risk of glioma associated with a higher order of birth (and presumed younger age at infection). The aim of this study was to examine whether birth order, family size, and other early life exposures are associated with the risk of glioma in adults using data collected in a large clinic-based US case-control study including 889 glioma cases and 903 community controls. A structured interviewer-administered questionnaire was used to collect information on family structure, childhood exposures and other potential risk factors. Logistic regression was used to calculate odds ratios (OR) and corresponding 95% confidence intervals (CI) for the association between early life factors and glioma risk. Persons having any siblings were at significantly lower risk for glioma when compared to those reporting no siblings (OR=0.64; 95% CI 0.44-0.93; p=0.020). Compared to first-borns, individuals with older siblings had a significantly lower risk (OR=0.75; 95% CI 0.61-0.91; p=0.004). Birth weight, having been breast fed in infancy, and season of birth were not associated with glioma risk. The current findings lend further support to a growing body of evidence that early exposure to childhood infections reduces the risk of glioma onset in children and adults.


Assuntos
Ordem de Nascimento , Exposição Ambiental/efeitos adversos , Características da Família , Glioma/etiologia , Irmãos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Feminino , Glioma/epidemiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Parto , Fatores de Risco , Estações do Ano , Fatores Socioeconômicos , Inquéritos e Questionários , Estados Unidos/epidemiologia , Adulto Jovem
18.
Cancers (Basel) ; 15(15)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37568623

RESUMO

The challenges in identifying effective therapies for CNS tumors continue to be daunting [...].

19.
J Neurooncol ; 110(1): 111-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22832897

RESUMO

Single-agent sunitinib, an oral small molecule inhibitor of multiple tyrosine kinase receptors, was evaluated for treatment of patients with recurrent glioblastoma (GB) and anaplastic astrocytoma (AA). Fourteen AA and 16 GB patients, all previously treated with surgery, radiotherapy, and temozolomide, were enrolled in a prospective phase II study at either first or second relapse. Patients were treated with daily sunitinib for 4 consecutive weeks, followed by a 2-week break. For AA patients, the most common side effects were fatigue (86 %), diarrhea (43 %), hand-foot syndrome (36 %), neutropenia (36 %), thrombocytopenia (36 %), and nausea (29 %). In the GB cohort, the most common side effects were fatigue (56 %), diarrhea (44 %), neutropenia (31 %), and thrombocytopenia (25 %). Six of 14 (43 %) AA and 5 of 16 (31 %) GB patients experienced grade 3 or greater toxicities. Five patients discontinued study due to drug toxicities. There were no partial or complete responses in either cohort; 8/14 (57 %) AA and 5/16 (31 %) GB patients had stable disease at the first planned assessment. Progression-free survival at 6 months was 21.5 % (AA) and 16.7 % (GB). Median overall survival was 12.1 months (AA) and 12.6 months (GB). These results are comparable to those reported in the literature in patients treated with standard cytotoxic therapies. This is the largest reported trial of sunitinib in recurrent malignant astrocytic gliomas to date, as well as contains the largest AA cohort. Nonetheless, sunitinib did not demonstrate significant anti-glioma activity in patients with recurrent malignant astrocytic gliomas.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Indóis/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , Pirróis/uso terapêutico , Adulto , Idoso , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Intervalo Livre de Doença , Feminino , Glioma/mortalidade , Glioma/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Sunitinibe
20.
Neurology ; 98(2): e164-e173, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34675104

RESUMO

OBJECTIVE: To determine the effectiveness of a 6-month, interactive, multimodal, Web-based EEG teaching program (EEGonline) in improving EEG analysis and interpretation skills for neurologists, neurology residents, and technologists, particularly in resource-limited settings. METHODS: Between June 2017 and November 2018, 179 learners originating from 20 African countries, Europe, and the United States were registered on the EEGonline course. Of these, 128 learners (91% African) participated in the study. Pre- and postcourse multiple choice question (MCQ) test results and EEGonline user logs were analyzed. Differences in pre- and posttest performance were correlated with quantified exposure to various EEGonline learning modalities. Participants' impressions of EEGonline efficacy and usefulness were assessed through pre- and postcourse satisfaction surveys. RESULTS: Ninety-one participants attempted both pre- and postcourse tests (71% response rate). Mean scores improved from 46.7% ± 17.6% to 64.1% ± 18%, respectively (p < 0.001, Cohen d 0.974). The largest improvement was in correct identification of normal features (43.2%-59.1%; p < 0.001, Cohen d 0.664) and artifacts (43.3%-61.6%; p < 0.001, Cohen d 0.836). Improvement in knowledge was associated with improved subjective confidence in EEG analysis. Overall confidence among postcourse survey respondents improved significantly from 35.9% to 81.9% (p < 0.001). Lecture notes, self-assessment quizzes, and discussion forums were the most utilized learning modalities. The majority of survey respondents (97.2%) concluded that EEGonline was a useful learning tool and 93% recommended that similar courses should be included in EEG training curricula. CONCLUSIONS: This study demonstrated that a multimodal, online EEG teaching tool was effective in improving EEG analysis and interpretation skills and may be useful in resource-poor settings.


Assuntos
Educação a Distância , Competência Clínica , Currículo , Eletroencefalografia , Humanos , Aprendizagem , Estudos Prospectivos , Ensino
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