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1.
Cell ; 152(5): 1065-76, 2013 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-23452854

RESUMEN

Medulloblastoma is the most common pediatric malignant brain tumor. Although current therapies improve survival, these regimens are highly toxic and are associated with significant morbidity. Here, we report that placental growth factor (PlGF) is expressed in the majority of medulloblastomas, independent of their subtype. Moreover, high expression of PlGF receptor neuropilin 1 (Nrp1) correlates with poor overall survival in patients. We demonstrate that PlGF and Nrp1 are required for the growth and spread of medulloblastoma: PlGF/Nrp1 blockade results in direct antitumor effects in vivo, resulting in medulloblastoma regression, decreased metastasis, and increased mouse survival. We reveal that PlGF is produced in the cerebellar stroma via tumor-derived Sonic hedgehog (Shh) and show that PlGF acts through Nrp1-and not vascular endothelial growth factor receptor 1-to promote tumor cell survival. This critical tumor-stroma interaction-mediated by Shh, PlGF, and Nrp1 across medulloblastoma subtypes-supports the development of therapies targeting PlGF/Nrp1 pathway.


Asunto(s)
Neoplasias Cerebelosas/patología , Cerebelo/metabolismo , Meduloblastoma/patología , Neuropilina-1/metabolismo , Proteínas Gestacionales/metabolismo , Transducción de Señal , Animales , Células Cultivadas , Neoplasias Cerebelosas/metabolismo , Humanos , Meduloblastoma/metabolismo , Ratones , Ratones Noqueados , Trasplante de Neoplasias , Comunicación Paracrina , Factor de Crecimiento Placentario , Trasplante Heterólogo , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo
2.
Proc Natl Acad Sci U S A ; 113(16): 4470-5, 2016 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-27044097

RESUMEN

Glioblastomas (GBMs) rapidly become refractory to anti-VEGF therapies. We previously demonstrated that ectopic overexpression of angiopoietin-2 (Ang-2) compromises the benefits of anti-VEGF receptor (VEGFR) treatment in murine GBM models and that circulating Ang-2 levels in GBM patients rebound after an initial decrease following cediranib (a pan-VEGFR tyrosine kinase inhibitor) administration. Here we tested whether dual inhibition of VEGFR/Ang-2 could improve survival in two orthotopic models of GBM, Gl261 and U87. Dual therapy using cediranib and MEDI3617 (an anti-Ang-2-neutralizing antibody) improved survival over each therapy alone by delaying Gl261 growth and increasing U87 necrosis, effectively reducing viable tumor burden. Consistent with their vascular-modulating function, the dual therapies enhanced morphological normalization of vessels. Dual therapy also led to changes in tumor-associated macrophages (TAMs). Inhibition of TAM recruitment using an anti-colony-stimulating factor-1 antibody compromised the survival benefit of dual therapy. Thus, dual inhibition of VEGFR/Ang-2 prolongs survival in preclinical GBM models by reducing tumor burden, improving normalization, and altering TAMs. This approach may represent a potential therapeutic strategy to overcome the limitations of anti-VEGFR monotherapy in GBM patients by integrating the complementary effects of anti-Ang2 treatment on vessels and immune cells.


Asunto(s)
Anticuerpos Antineoplásicos/farmacología , Glioblastoma , Macrófagos , Proteínas de Neoplasias , Neoplasias Experimentales , Neovascularización Patológica , Quinazolinas/farmacología , Receptores de Factores de Crecimiento Endotelial Vascular , Ribonucleasa Pancreática , Animales , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patología , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/metabolismo , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Ribonucleasa Pancreática/antagonistas & inhibidores , Ribonucleasa Pancreática/metabolismo
3.
Artículo en Inglés | MEDLINE | ID: mdl-31550380

RESUMEN

A Native community developed the Wicozani Instrument, a 9-item self-report measure, to assess overall health and well-being from an Indigenous epistemology. The Wicozani Instrument measures mental, physical, and spiritual health and their importance to an individual's quality of life. The instrument's validity and reliability was examined through two studies. Study 1 utilized standardized measures from Native (i.e., Awareness of Connectedness Scale) and Western (i.e., Psychological Sense of School Membership and Suicide Ideation Questionnaire) epistemologies with Native and non-Native youth. Study 2 utilized a community created measure (i.e., Indigenous Healing Strategies Scale) with Dakota women. Results suggest the Wicozani Instrument is valid and reliable. The development of an Indigenous measure of overall health and well-being addresses Western atomistic frameworks, which often perpetuate the perception of Native identity as a risk factor for poor health, and works to disrupt the Cycle of Native Health Disparities.


Asunto(s)
Disparidades en el Estado de Salud , Indígenas Norteamericanos , Salud de las Minorías , Satisfacción Personal , Psicometría/normas , Calidad de Vida , Autoinforme/normas , Humanos , Estados Unidos
4.
Eur J Pharm Biopharm ; 117: 286-291, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28411056

RESUMEN

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been studied as potential carriers for both dermal and transdermal drug delivery. SLN contain lipid droplets that are fully crystallized and have a highly-ordered crystalline structure. NLC are modified SLN in which the lipid phase contains both solid and liquid lipids at room temperature. SLN and NLC are thought to combine the advantages of polymeric particles, liposomes and emulsions. Therefore they provide high encapsulation percentages, better protection for incorporated actives and allow for control of desired release profile. In this work, Resveratrol, Vitamin E (VE), and Epigallocatechin Gallate (EGCG) all potent antioxidants known to provide protection to the skin, were formulated into lipid nanoparticles. Several different formulations were successfully developed and demonstrated high uniformity and stability. Both resveratrol and VE lipid nanoparticles provided effective protection of actives against UV induced degradation. However, lipid nanoparticles did not show protection from UV degradation for EGCG in this work. An active release study exhibited a sustained release of resveratrol over 70% after 24h. Skin penetration studies showed that lipid nanoparticles directionally improved the penetration of resveratrol through the stratum corneum. Our findings suggest that lipid nanoparticles are promising viable carriers for the delivery of resveratrol and VE to provide longlasting antioxidant benefits to the skin.


Asunto(s)
Catequina/análogos & derivados , Nanopartículas/metabolismo , Cuidados de la Piel/métodos , Piel/metabolismo , Estilbenos/metabolismo , Vitamina E/metabolismo , Catequina/administración & dosificación , Catequina/síntesis química , Catequina/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Femenino , Humanos , Metabolismo de los Lípidos , Lípidos/administración & dosificación , Lípidos/química , Persona de Mediana Edad , Nanopartículas/administración & dosificación , Nanopartículas/química , Técnicas de Cultivo de Órganos , Resveratrol , Piel/efectos de los fármacos , Estilbenos/administración & dosificación , Estilbenos/síntesis química , Vitamina E/administración & dosificación , Vitamina E/síntesis química
5.
Med Phys ; 44(8): 4009-4024, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28543961

RESUMEN

PURPOSE: Low contrast (LC) detectability is a common test criterion for diagnostic radiologic quality control (QC) programs. Automation of this test is desirable in order to reduce human variability and to speed up analysis. However, automation is challenging due to the complexity of the human visual perception system and the ability to create algorithms that mimic this response. This paper describes the development and testing of an automated LC detection algorithm for use in the analysis of magnetic resonance (MR) images of the American College of Radiology (ACR) QC phantom. METHODS: The detection algorithm includes fuzzy logic decision processes and various edge detection methods to quantify LC detectability. Algorithm performance was first evaluated using a single LC phantom MR image with the addition of incremental zero mean Gaussian noise resulting in a total of 200 images. A c-statistic was calculated to determine the role of CNR to indicate when the algorithm would detect ten spokes. To evaluate inter-rater agreement between experienced observers and the algorithm, a blinded observer study was performed on 196 LC phantom images acquired from nine clinical MR scanners. The nine scanners included two MR manufacturers and two field strengths (1.5 T, 3.0 T). Inter-rater and algorithm-rater agreement was quantified using Krippendorff's alpha. RESULTS: For the Gaussian noise added data, CNR ranged from 0.519 to 11.7 with CNR being considered an excellent discriminator of algorithm performance (c-statistic = 0.9777). Reviewer scoring of the clinical phantom data resulted in an inter-rater agreement of 0.673 with the agreement between observers and algorithm equal to 0.652, both of which indicate significant agreement. CONCLUSIONS: This study demonstrates that the detection of LC test patterns for MR imaging QC programs can be successfully developed and that their response can model the human visual detection system of expert MR QC readers.


Asunto(s)
Algoritmos , Imagen por Resonancia Magnética , Reconocimiento de Normas Patrones Automatizadas , Humanos , Espectroscopía de Resonancia Magnética , Fantasmas de Imagen
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