Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Nat Aging ; 3(7): 846-865, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37231196

RESUMEN

Aging markedly increases cancer risk, yet our mechanistic understanding of how aging influences cancer initiation is limited. Here we demonstrate that the loss of ZNRF3, an inhibitor of Wnt signaling that is frequently mutated in adrenocortical carcinoma, leads to the induction of cellular senescence that remodels the tissue microenvironment and ultimately permits metastatic adrenal cancer in old animals. The effects are sexually dimorphic, with males exhibiting earlier senescence activation and a greater innate immune response, driven in part by androgens, resulting in high myeloid cell accumulation and lower incidence of malignancy. Conversely, females present a dampened immune response and increased susceptibility to metastatic cancer. Senescence-recruited myeloid cells become depleted as tumors progress, which is recapitulated in patients in whom a low myeloid signature is associated with worse outcomes. Our study uncovers a role for myeloid cells in restraining adrenal cancer with substantial prognostic value and provides a model for interrogating pleiotropic effects of cellular senescence in cancer.


Asunto(s)
Neoplasias de la Corteza Suprarrenal , Carcinoma Corticosuprarrenal , Masculino , Animales , Femenino , Carcinoma Corticosuprarrenal/genética , Envejecimiento , Senescencia Celular , Transducción de Señal , Neoplasias de la Corteza Suprarrenal/genética , Microambiente Tumoral
2.
Eval Program Plann ; 97: 102262, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36907053

RESUMEN

Federal funding agencies have invested significant resources supporting evidence-based, innovative approaches that address education problems and incorporate rigorous design and evaluation, particularly through randomized controlled trials (RCTs), the gold standard for yielding causal inference in scientific research. In this study, we introduced factors (i.e., evaluation design, attrition, outcome measures, analytic approach, and fidelity of implementation) that are often times required in the Federal Notice for application by the U.S. Department of Education, with an emphasis on What Works Clearinghouse (WWC) standards. We further presented a federally funded research protocol with a multi-year, clustered RCT design to determine the impact of an instructional intervention on students' academic performance in high-needs schools. In the protocol, we elaborated on how our research design, evaluation plan, power analysis, as well as confirmatory research questions and analytical approaches were aligned with the grant requirement and WWC standards. We intend to provide a road map to meeting WWC standards and to increase the likelihood of successful grant applications.


Asunto(s)
Organización de la Financiación , Estudiantes , Humanos , Evaluación de Programas y Proyectos de Salud , Escolaridad , Instituciones Académicas
3.
Matrix Biol ; 117: 1-14, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36773748

RESUMEN

Supravalvular aortic stenosis (SVAS) is an autosomal dominant disease resulting from elastin (ELN) haploinsufficiency. Individuals with SVAS typically develop a thickened arterial media with an increased number of elastic lamellae and smooth muscle cell (SMC) layers and stenosis superior to the aortic valve. A mouse model of SVAS (Eln+/-) was generated that recapitulates many aspects of the human disease, including increased medial SMC layers and elastic lamellae, large artery stiffness, and hypertension. The vascular changes in these mice were thought to be responsible for the hypertension phenotype. However, a renin gene (Ren) duplication in the original 129/Sv genetic background and carried through numerous strain backcrosses raised the possibility of renin-mediated effects on blood pressure. To exclude excess renin activity as a disease modifier, we utilized the Cre-LoxP system to rederive Eln hemizygous mice on a pure C57BL/6 background (Sox2-Cre;Elnf/f). Here we show that Sox2-Cre;Eln+/f mice, with a single Ren1 gene and normal renin levels, phenocopy the original global knockout line. Characteristic traits include an increased number of elastic lamellae and SMC layers, stiff elastic arteries, and systolic hypertension with widened pulse pressure. Importantly, small resistance arteries of Sox2-Cre;Eln+/f mice exhibit a significant change in endothelial cell function and hypercontractility to angiotensin II, findings that point to pathway-specific alterations in resistance arteries that contribute to the hypertensive phenotype. These data confirm that the cardiovascular changes, particularly systolic hypertension, seen in Eln+/- mice are due to Eln hemizygosity rather than Ren duplication.


Asunto(s)
Estenosis Aórtica Supravalvular , Hipertensión , Animales , Humanos , Ratones , Presión Sanguínea , Elastina/genética , Elastina/metabolismo , Haploinsuficiencia , Hipertensión/genética , Hipertensión/metabolismo , Ratones Endogámicos C57BL , Renina/genética
4.
Pediatr Crit Care Med ; 24(2): e76-e83, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36661427

RESUMEN

OBJECTIVES: Examine initial feasibility and utility of a battery of measures administered via telephone interview with a caregiver for describing long-term outcomes in individuals with a history of disorders of consciousness (DoC) after pediatric acquired brain injury (ABI). DESIGN: Cross-sectional. SETTING: Caregiver interview administered via telephone. PATIENTS: Convenience sample admitted to an inpatient pediatric neurorehabilitation unit with DoC after ABI at least 1 year prior to assessment (n = 41, 5-22 yr old at assessment). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The Vineland Adaptive Behavior Scales, Third Edition (Vineland-3), and Glasgow Outcome Scale-Extended Pediatric Revision (GOS-E Peds) were examined. Administration time of the Vineland-3 ranged from 13 to 101 minutes (m = 50) and the GOS-E Peds ranged from 2 to 10 minutes (m = 3). Vineland-3 Adaptive Behavior Composite (ABC) ranged from standard scores (SSs) of 20 (exceptionally low) to 100 (average) and GOS-E Peds scores ranged from 3 (i.e., upper moderate disability) to 7 (vegetative state). Lower adaptive functioning on the Vineland-3 ABC was strongly associated with greater disability on the GOS-E Peds (r = -0.805). On the Vineland-3 ABC, 19.5% earned the lowest possible score, whereas 12.2% obtained the lowest possible score for survivors on the GOS-E Peds; only 7.3% earned lowest scores on both measures. CONCLUSIONS: The Vineland-3 and GOS-E Peds were feasibly administered by telephone and were complementary in this cohort; the GOS-E provided a quick and easy measure of gross functional outcome, whereas the Vineland-3 took longer to administer but provided a greater level of detail about functioning. When both measures were used together, the range and variability of scores were maximized.


Asunto(s)
Lesiones Encefálicas , Trastornos de la Conciencia , Niño , Humanos , Escala de Consecuencias de Glasgow , Trastornos de la Conciencia/etiología , Estudios Transversales , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/rehabilitación , Adaptación Psicológica
5.
Orbit ; 41(5): 642-646, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33926355

RESUMEN

Malignant peripheral nerve sheath tumor is a rare tumor which infrequently involves the orbit. They occur most often in the setting of neurofibromatosis 1 (NF1), and therefore the involvement of the orbit without a history of NF1 is even less common. Management of this tumor is fraught with a high rate of recurrences and metastases, with a high mortality rate. Primary surgical excision with tumor-free margins remains the primary treatment, while adjuvant modalities such as radiation and chemotherapy play a more minor role.


Asunto(s)
Neoplasias de la Vaina del Nervio , Neurofibromatosis 1 , Neurofibrosarcoma , Humanos , Neoplasias de la Vaina del Nervio/diagnóstico por imagen , Neoplasias de la Vaina del Nervio/cirugía , Neurofibromatosis 1/patología , Neurofibrosarcoma/diagnóstico por imagen , Neurofibrosarcoma/cirugía , Órbita/patología
6.
Behav Sci (Basel) ; 10(6)2020 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-32604770

RESUMEN

In this study, we described and compared an English as a foreign language (EFL) teacher's pedagogical behaviors in traditional and problem-based learning (PBL) classroom settings in a Chinese university. In spring 2019, we collected six 45-min videos, three in each condition, covering three modules: (a) warm-up and vocabulary, (b) essay structure, and (c) writing. The analyses of the teacher's pedagogical behaviors and her interaction with students indicated that the instructor spent most of the instructional time delivering higher-order thinking content in both traditional and PBL classes. The teacher's activity structure influenced students' communication mode. Although the instructor provided students with more group discussion activities in the PBL classroom, lecturing was observed to be the primary delivery method in both classes. These results suggest that the application of PBL strategies in the EFL classroom did not significantly restructure the teacher's pedagogical behaviors, and thus, failed to achieve the goal of providing students with more opportunities for improving their expressive English language proficiency. These findings underscore the need to develop an effective PBL-related curriculum and professional development opportunities for EFL teachers to effectively implement the PBL approach in the classroom.

7.
Evolution ; 72(11): 2378-2393, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30246244

RESUMEN

Closely related taxa with dissimilar morphologies are often considered to have diverged via natural selection favoring different phenotypes. However, some studies have found these scenarios to be paired with limited or no genetic differentiation. Desmognathus quadramaculatus and D. marmoratus are sympatric salamander species thought to represent a case of ecological speciation based on distinct morphologies, but the results of previous studies have not resolved corresponding patterns of lineage divergence. Here, we use genome-wide data to test this hypothesis of ecological speciation. Population structure analyses partitioned individuals geographically, but not morphologically, into two adjacent regions of western North Carolina: Pisgah and Nantahala. Phylogenetic analyses confirmed the nominal species are nonmonophyletic and resolved deep divergence between the two geographic clusters. Model-testing overwhelmingly supported the hypothesis that lineage divergence followed geography. Finally, ecological niche modeling showed that Pisgah and Nantahala individuals occupy different climatic niches, and geographic boundaries for the two lineages correspond to differences in precipitation regimes across southern Appalachia. Overall, we reject the previous hypothesis of ecological speciation based on microhabitat partitioning. Instead, our results suggest that there are two cryptic lineages, each containing the same pair of morphotypes.


Asunto(s)
Genoma , Urodelos/clasificación , Urodelos/genética , Animales , Clima , Especiación Genética , North Carolina , Fenotipo , Filogeografía , Análisis de Secuencia de ADN , Especificidad de la Especie , Simpatría , Urodelos/anatomía & histología
8.
Mol Cancer Ther ; 4(10): 1541-7, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16227403

RESUMEN

Incomplete DNA repair or misrepair can contribute to the cytotoxicity of DNA double-strand breaks. Consequently, interference with double-strand break repair, by pharmacologic or genetic means, is likely to sensitize tumor cells to ionizing radiation. The current studies were designed to inhibit the nonhomologous end joining repair pathway by interfering with the function of the XRCC4/ligase IV complex. A PCR-generated fragment of the XRCC4 gene, encompassing the homodimerization and ligase IV-binding domains, was inserted into a plasmid vector (pFLAG-CMV-2) expressing the FLAG peptide and the cassette encoding FLAG-tagged XRCC4 fragment was cloned into an adenoviral vector. Both the plasmid and the corresponding adenovirus elicited robust expression of a truncated XRCC4 protein designed to compete in a dominant-negative fashion with full-length XRCC4 for binding to ligase IV. Binding of the XRCC4 fragment to ligase IV in vivo was confirmed by immunoprecipitation. Clonogenic survival assays showed that the adenovirus expressing the truncated XRCC4 protein sensitizes MDA-MB-231 breast tumor cells to ionizing radiation, presumably through interference with the functional activity of ligase IV, leading to inhibition of the final ligation step in end joining. These studies support the potential clinical utility of combining radiation therapy with agents that inhibit DNA double-strand break repair.


Asunto(s)
Neoplasias de la Mama/radioterapia , Proteínas de Unión al ADN/fisiología , Adenoviridae/genética , Sitios de Unión , Western Blotting , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular , Línea Celular Tumoral , ADN Ligasa (ATP) , ADN Ligasas/aislamiento & purificación , ADN Ligasas/metabolismo , Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Fragmentos de Péptidos/biosíntesis , Fragmentos de Péptidos/genética , Tolerancia a Radiación/genética
9.
Biochem Pharmacol ; 68(9): 1699-708, 2004 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-15450935

RESUMEN

The influence of p53 function and caspase 3 activity on the capacity of the antifolate, methotrexate, to promote senescence arrest and apoptotic cell death was investigated in breast tumor cells. In p53 wild-type, but caspase 3 deficient MCF-7 breast tumor cells, death of approximately 40% of the cell population was observed immediately after acute exposure to 10 microM methotrexate (the IC80 value for a 2 h drug exposure). There was no evidence of either DNA fragmentation, a sub G0 population or morphological alterations indicative of apoptosis; however, PARP cleavage was detected. Cell death was succeeded by growth arrest for at least 72 h--where arrest was characterized by expression of the senescence marker, beta-galactosidase. The response to methotrexate in MCF-7/E6 cells with attenuated p53 function was also primarily growth arrest--but lacking characteristics of senescence. In contrast, MCF-7 cells which expressed caspase 3 demonstrated a gradual and continuous loss of cell viability and unequivocal morphological evidence of apoptosis. DNA fragmentation indicative of apoptosis was also detected after exposure to methotrexate in p53 mutant MDA-MB231 breast tumor cells which also express caspase 3. Methotrexate-induced both p53 and p21waf1/cip1 in MCF-7 cells within 6 h; however, no significant DNA strand breakage was evident before 18 h, suggesting that the induction of p53 reflects a response to cellular stress other than DNA damage, such as nucleotide depletion. Overall, these studies suggest that the nature of the cellular response to methotrexate depends, in large part, on p53 and caspase function. p53 appears to be required for methotrexate-induced senescence, but not apoptosis, caspase 3 is required for DNA fragmentation and the morphological changes associated with apoptosis, while neither p53 nor caspase 3 are required for methotrexate-induced growth arrest. Furthermore, the senescence phenotype may occur in the absence of direct DNA damage.


Asunto(s)
Apoptosis/efectos de los fármacos , Caspasas/fisiología , Senescencia Celular/efectos de los fármacos , Metotrexato/farmacología , Proteína p53 Supresora de Tumor/fisiología , Apoptosis/fisiología , Neoplasias de la Mama/patología , Caspasa 3 , Senescencia Celular/fisiología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/biosíntesis , Daño del ADN/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Células Tumorales Cultivadas
10.
J Steroid Biochem Mol Biol ; 92(5): 365-74, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15698541

RESUMEN

A senescence-like growth arrest succeeded by recovery of proliferative capacity was observed in MCF-7 breast tumor cells exposed to fractionated radiation, 5 x 2 Gy. Exposure to EB 1089, an analog of the steroid hormone 1alpha, 25 dihydroxycholecalciferol (1alpha, 25 dihydroxy Vitamin D(3); calcitriol), prior to irradiation promoted cell death and delayed both the development of a senescent phenotype and the recovery of proliferative capacity. EB 1089 also reduced clonogenic survival over and above that produced by fractionated radiation alone and further conferred susceptibility to apoptosis in MCF-7 cells exposed to radiation. In contrast, EB 1089 failed to enhance the response to radiation (or to promote apoptosis) in normal breast epithelial cells or BJ fibroblast cells. EB 1089 treatment and fractionated radiation additively promoted ceramide generation and suppressed expression of polo-like kinase 1. Taken together, these data indicate that EB 1089 (and 1alpha, 25 dihydroxycholecalciferol or its analogs) could selectively enhance breast tumor cell sensitivity to radiation through the promotion of cell death, in part through the generation of ceramide and the suppression of polo-like kinase.


Asunto(s)
Neoplasias de la Mama/patología , Calcitriol/análogos & derivados , Calcitriol/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Ceramidas/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/efectos de la radiación , Humanos , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Quinasa Tipo Polo 1
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...