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1.
Health Aff Sch ; 1(1): qxad007, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38756832

RESUMEN

The United States falls far short of its potential for delivering care that is effective, efficient, safe, timely, patient-centered, and equitable. We put forward the Better Care Plan, an overarching blueprint to address the flaws in our current system. The plan calls for continuously improving care, moving all payers to risk-adjusted prospective payment, and creating national entities for collecting, analyzing, and reporting patient safety and quality-of-care outcomes data. A number of recommendations are made to achieve these goals.

2.
Cancer Res ; 65(10): 4389-400, 2005 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-15899831

RESUMEN

Inhibition of vascular endothelial growth factor-A (VEGF) signaling is a promising therapeutic approach that aims to stabilize the progression of solid malignancies by abrogating tumor-induced angiogenesis. This may be accomplished by inhibiting the kinase activity of VEGF receptor-2 (KDR), which has a key role in mediating VEGF-induced responses. The novel indole-ether quinazoline AZD2171 is a highly potent (IC50 < 1 nmol/L) ATP-competitive inhibitor of recombinant KDR tyrosine kinase in vitro. Concordant with this activity, in human umbilical vein endothelial cells, AZD2171 inhibited VEGF-stimulated proliferation and KDR phosphorylation with IC50 values of 0.4 and 0.5 nmol/L, respectively. In a fibroblast/endothelial cell coculture model of vessel sprouting, AZD2171 also reduced vessel area, length, and branching at subnanomolar concentrations. Once-daily oral administration of AZD2171 ablated experimental (VEGF-induced) angiogenesis in vivo and inhibited endochondral ossification in bone or corpora luteal development in ovary; physiologic processes that are highly dependent upon neovascularization. The growth of established human tumor xenografts (colon, lung, prostate, breast, and ovary) in athymic mice was inhibited dose-dependently by AZD2171, with chronic administration of 1.5 mg per kg per day producing statistically significant inhibition in all models. A histologic analysis of Calu-6 lung tumors treated with AZD2171 revealed a reduction in microvessel density within 52 hours that became progressively greater with the duration of treatment. These changes are indicative of vascular regression within tumors. Collectively, the data obtained with AZD2171 are consistent with potent inhibition of VEGF signaling, angiogenesis, neovascular survival, and tumor growth. AZD2171 is being developed clinically as a once-daily oral therapy for the treatment of cancer.


Asunto(s)
Neoplasias/tratamiento farmacológico , Neoplasias/enzimología , Inhibidores de Proteínas Quinasas/farmacología , Quinazolinas/farmacología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Administración Oral , Animales , Disponibilidad Biológica , Desarrollo Óseo/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Cuerpo Lúteo/efectos de los fármacos , Cuerpo Lúteo/crecimiento & desarrollo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/enzimología , Células Endoteliales/metabolismo , Proteínas de la Matriz Extracelular , Femenino , Humanos , Ratones , Cadenas Pesadas de Miosina , Neoplasias/irrigación sanguínea , Neoplasias/patología , Miosina Tipo IIB no Muscular , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacocinética , Proteínas/antagonistas & inhibidores , Quinazolinas/farmacocinética , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Receptor 3 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Ensayos Antitumor por Modelo de Xenoinjerto
3.
Nat Commun ; 8(1): 12, 2017 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-28400552

RESUMEN

RNA-binding proteins play a key role in shaping gene expression profiles during stress, however, little is known about the dynamic nature of these interactions and how this influences the kinetics of gene expression. To address this, we developed kinetic cross-linking and analysis of cDNAs (χCRAC), an ultraviolet cross-linking method that enabled us to quantitatively measure the dynamics of protein-RNA interactions in vivo on a minute time-scale. Here, using χCRAC we measure the global RNA-binding dynamics of the yeast transcription termination factor Nab3 in response to glucose starvation. These measurements reveal rapid changes in protein-RNA interactions within 1 min following stress imposition. Changes in Nab3 binding are largely independent of alterations in transcription rate during the early stages of stress response, indicating orthogonal transcriptional control mechanisms. We also uncover a function for Nab3 in dampening expression of stress-responsive genes. χCRAC has the potential to greatly enhance our understanding of in vivo dynamics of protein-RNA interactions.Protein RNA interactions are dynamic and regulated in response to environmental changes. Here the authors describe 'kinetic CRAC', an approach that allows time resolved analyses of protein RNA interactions with minute time point resolution and apply it to gain insight into the function of the RNA-binding protein Nab3.


Asunto(s)
Regulación Fúngica de la Expresión Génica , Proteínas Nucleares/genética , ARN de Hongos/genética , Proteínas de Unión al ARN/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Transcriptoma , Medios de Cultivo/farmacología , ADN Complementario/genética , ADN Complementario/metabolismo , Perfilación de la Expresión Génica , Glucosa/deficiencia , Cinética , Proteínas Nucleares/metabolismo , Unión Proteica , ARN de Hongos/metabolismo , Proteínas de Unión al ARN/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efectos de la radiación , Proteínas de Saccharomyces cerevisiae/metabolismo , Estrés Fisiológico , Factores de Tiempo , Rayos Ultravioleta
4.
Cancer Res ; 62(16): 4645-55, 2002 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12183421

RESUMEN

ZD6474 [N-(4-bromo-2-fluorophenyl)-6-methoxy-7-[(1-methylpiperidin-4-yl)methoxy]quinazolin-4-amine]is a potent, p.o. active, low molecular weight inhibitor of kinase insert domain-containing receptor [KDR/vascular endothelial growth factor receptor (VEGFR) 2] tyrosine kinase activity (IC(50) = 40 nM). This compound has some additional activity versus the tyrosine kinase activity of fms-like tyrosine kinase 4 (VEGFR3;IC(50) = 110 nM) and epidermal growth factor receptor (EGFR/HER1; IC(50) = 500 nM) and yet demonstrates selectivity against a range of other tyrosine and serine-threonine kinases. The activity of ZD6474 versus KDR tyrosine kinase translates into potent inhibition of vascular endothelial growth factor-A (VEGF)-stimulated endothelial cell (human umbilical vein endothelial cell) proliferation in vitro (IC(50) = 60 nM). Selective inhibition of VEGF signaling has been demonstrated in vivo in a growth factor-induced hypotension model in anesthetized rat: administration of ZD6474 (2.5 mg/kg, i.v.) reversed a hypotensive change induced by VEGF (by 63%) but did not significantly affect that induced by basic fibroblast growth factor. Once-daily oral administration of ZD6474 to growing rats for 14 days produced a dose-dependent increase in the femoro-tibial epiphyseal growth plate zone of hypertrophy, which is consistent with inhibition of VEGF signaling and angiogenesis in vivo. Administration of 50 mg/kg/day ZD6474 (once-daily, p.o.) to athymic mice with intradermally implanted A549 tumor cells also inhibited tumor-induced neovascularization significantly (63% inhibition after 5 days; P < 0.001). Oral administration of ZD6474 to athymic mice bearing established (0.15-0.47 cm(3)), histologically distinct (lung, prostate, breast, ovarian, colon, or vulval) human tumor xenografts or after implantation of aggressive syngeneic rodent tumors (lung, melanoma) in immunocompetent mice, produced a dose-dependent inhibition of tumor growth in all cases. Statistically significant antitumor activity was evident in each model with at least 25 mg/kg ZD6474 once daily (P < 0.05, one-tailed t test). Histological analysis of Calu-6 tumors treated with 50 mg/kg/day ZD6474 for 24 days showed a significant reduction (>70%) in CD31 (endothelial cell) staining in nonnecrotic regions. ZD6474 also restrained growth of much larger (0.9 cm(3) volume) Calu-6 lung tumor xenografts and induced profound regression in established PC-3 prostate tumors of 1.4 cm(3) volume. ZD6474 is currently in Phase I clinical development as a once-daily oral therapy in patients with advanced cancer.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antineoplásicos/farmacología , Factores de Crecimiento Endotelial/antagonistas & inhibidores , Linfocinas/antagonistas & inhibidores , Piperidinas/farmacología , Quinazolinas/farmacología , Administración Oral , Animales , División Celular/efectos de los fármacos , Factores de Crecimiento Endotelial/fisiología , Inhibidores Enzimáticos/farmacología , Femenino , Humanos , Linfocinas/fisiología , Masculino , Ratones , Neoplasias Experimentales/irrigación sanguínea , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Neovascularización Patológica/tratamiento farmacológico , Ratas , Ratas Wistar , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Receptores de Factores de Crecimiento/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular , Transducción de Señal/efectos de los fármacos , Células Tumorales Cultivadas , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Anticancer Res ; 23(5A): 3639-50, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14666659

RESUMEN

From immunohistochemical and ligand-binding studies, it is known that the epidermal growth factor receptor (EGFR), a member of the erbB family of receptors, is expressed in tissues of epithelial, mesenchymal and neuronal origin and plays a major role in normal cellular processes such as proliferation, differentiation and development. EGFR is highly expressed in a number of solid tumours and its expression correlates with tumour progression, resistance to chemotherapy and a poor prognosis; it is consequently an attractive target for the rational design of novel anticancer agents. Knowledge of the role of EGFR in normal tissues will help the understanding of the adverse events associated with such agents. Studies in knockout mice and preclinical toxicology studies have shown that the major effects of inhibiting the EGFR are skin and gastrointestinal toxicities. Clinical studies with inhibitors of EGFR, such as gefitinib, cetuximab and erlotinib, have shown a favourable adverse-event profile, primarily consisting of skin and gastrointestinal toxicities, as predicted from the mechanism-based effects observed in preclinical studies.


Asunto(s)
Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/fisiología , Animales , Antineoplásicos/farmacología , Inhibidores Enzimáticos/farmacología , Receptores ErbB/metabolismo , Gefitinib , Humanos , Ratones , Ratones Noqueados , Quinazolinas/farmacología
6.
Exp Toxicol Pathol ; 55(6): 413-31, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15384248

RESUMEN

This is the second part of a series of three articles on trimming instructions of rat and mouse protocol organs and tissues in regulatory type toxicity studies, covering the respiratory, male and female genital, and the endocrine systems. The article is based on the experience of the European RITA and American NACAD working groups and is an extended revision of trimming guides published in 1995 (Bahnemann et al.). The optimum localization for tissue preparation, the sample size, the direction of sectioning and the number of sections to be prepared is described organ by organ. These descriptions are illustrated for each organ by a schematic drawing and/or a macro-photograph showing the plane of section as well as a low magnification of the H&E stained slide demonstrating the optimum "end-product". The objectives of this work, as addressed in detail in the first part (Ruehl-Fehlert et al. 2003), are to standardize tissue sampling and trimming, to improve the comparability of historical data obtained from different studies and different laboratories, ensure the presence of all relevant target sites for histopathological evaluation and provide technical advice for preparatory techniques during necropsy, fixation and trimming. dardize tissue sampling and trimming, to improve the comparability of historical data obtained from different studies and different laboratories, ensure the presence of all relevant target sites for histopathological evaluation and provide technical advice for preparatory techniques during necropsy, fixation and trimming.


Asunto(s)
Técnicas de Preparación Histocitológica/normas , Manejo de Especímenes/normas , Pruebas de Toxicidad/métodos , Animales , Femenino , Masculino , Ratones , Ratas
7.
Toxicol Pathol ; 34(2): 131-47, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16537292

RESUMEN

The formation of new blood vessels from a pre-existing vascular bed, termed "angiogenesis," is of critical importance for the growth and development of the animal since it is required for the growth of the skeleton during endochondral ossification, development and cycling of the corpus luteum and uterus, and for the repair of tissues during wound healing. "Vasculogenesis," the de novo formation of blood vessels is also important for the proper function and development of the vascular system in the embryo. New blood vessel formation is a prominent feature and permissive factor in the relentless progression of many human diseases, one of the most important examples of which is neoplasia. It is for this reason that angiogenesis is considered to be one of the hallmarks of cancer. The development of new classes of drugs that inhibit the growth and proper functioning of new blood vessels in vivo is likely to provide significant therapeutic benefit in the treatment of cancer, as well as other conditions where angiogenesis is a strong driver to the disease process. During the preclinical safety testing of these drugs, it is becoming increasingly clear that their in vivo efficacy is reflected in the profile of "expected toxicity" (resulting from pharmacology) observed in laboratory animals, so much so, that this profile of "desired" toxicity may act as a signature for their anti-angiogenic effect. In this article we review the major mechanisms controlling angiogenesis and its role during endochondral ossification. We also review the effects of perturbation of endochondral ossification through four mechanisms-inhibition of vascular endothelial growth factor (VEGF), pp60 c-Src kinase and matrix metalloproteinases as well as disruption of the blood supply with vascular targeting agents. Inhibition through each of these mechanisms appears to have broadly similar effects on the epiphyseal growth plate characterised by thickening due to the retention of hypertrophic chondrocytes resulting from the inhibition of angiogenesis. In contrast, in the metaphysis there are differing effects reflecting the specific role of these targets at this site.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Placa de Crecimiento/irrigación sanguínea , Placa de Crecimiento/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos , Angiopoyetinas/fisiología , Animales , Matriz Extracelular/fisiología , Placa de Crecimiento/citología , Humanos , Neovascularización Fisiológica/fisiología , Osteogénesis/efectos de los fármacos , Pericitos/fisiología , Proteínas Proto-Oncogénicas pp60(c-src)/antagonistas & inhibidores , Proteínas Proto-Oncogénicas pp60(c-src)/fisiología , Ratas , Ratas Sprague-Dawley , Receptores de Factores de Crecimiento Endotelial Vascular/fisiología , Factor A de Crecimiento Endotelial Vascular/fisiología
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