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1.
New Dir Child Adolesc Dev ; 2017(158): 25-41, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29243385

RESUMO

We present results from early learning programs in six African countries: Ethiopia, Kenya, Liberia, Malawi, Tanzania, and Uganda. In partnership with ministries of education, RTI International has worked within government systems to support the design and deployment of locally contextualized materials, training, and assessment tools, with the goal of improving outcomes for early learners in primary schools, and in Kenya and Tanzania preprimary as well. Here we report on the experience and evidence of impact from specific programs in each country, including summary assessment results when available. In several countries with completed impact evaluations, there are significant and important learning gains of between 0.2 and 2.57 SD in effect size; in one case the percentage of students reaching grade-level reading proficiency increased from 12% to 47%. In the context of increased urgency surrounding what UNESCO has called a "global learning crisis," these experiences provide useful lessons for policymakers and practitioners alike.


Assuntos
Desempenho Acadêmico , Intervenção Educacional Precoce , Aprendizagem , Desempenho Acadêmico/estatística & dados numéricos , Criança , Pré-Escolar , Intervenção Educacional Precoce/estatística & dados numéricos , Etiópia , Humanos , Quênia , Libéria , Malaui , Tanzânia , Uganda
2.
Mol Cancer Res ; 7(4): 498-510, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19372579

RESUMO

Several breast cancer tumor models respond to estradiol (E(2)) by undergoing apoptosis, a phenomenon known to occur in clinical breast cancer. Before the application of tamoxifen as an endocrine therapy, high-dose E(2) or diethystilbesterol treatment was successfully used, albeit with unfavorable side effects. It is now recognized that such an approach may be a potential endocrine therapy option. We have explored the mechanism of E(2)-induced tumor regression in our T47D:A18/PKCalpha tumor model that exhibits autonomous growth, tamoxifen resistance, and E(2)-induced tumor regression. Fulvestrant, a selective estrogen receptor (ER) down-regulator, prevents T47D:A18/PKCalpha E(2)-induced tumor growth inhibition and regression when given before or after tumor establishment, respectively. Interestingly, E(2)-induced growth inhibition is only observed in vivo or when cells are grown in Matrigel but not in two-dimensional tissue culture, suggesting the requirement of the extracellular matrix. Tumor regression is accompanied by increased expression of the proapoptotic FasL/FasL ligand proteins and down-regulation of the prosurvival Akt pathway. Inhibition of colony formation in Matrigel by E(2) is accompanied by increased expression of FasL and short hairpin RNA knockdown partially reverses colony formation inhibition. Classic estrogen-responsive element-regulated transcription of pS2, PR, transforming growth factor-alpha, C3, and cathepsin D is independent of the inhibitory effects of E(2). A membrane-impermeable E(2)-BSA conjugate is capable of mediating growth inhibition, suggesting the involvement of a plasma membrane ER. We conclude that E(2)-induced T47D:A18/PKCalpha tumor regression requires participation of ER-alpha, the extracellular matrix, FasL/FasL ligand, and Akt pathways, allowing the opportunity to explore new predictive markers and therapeutic targets.


Assuntos
Estradiol/farmacologia , Estrogênios/farmacologia , Matriz Extracelular/metabolismo , Neoplasias Mamárias Experimentais/prevenção & controle , Proteína Quinase C-alfa/metabolismo , Receptores de Estrogênio/metabolismo , Animais , Apoptose/fisiologia , Catepsina D/genética , Catepsina D/metabolismo , Linhagem Celular Tumoral , Ensaio de Unidades Formadoras de Colônias , Complemento C3/genética , Complemento C3/metabolismo , Proteína Ligante Fas/antagonistas & inibidores , Proteína Ligante Fas/metabolismo , Humanos , Neoplasias Mamárias Experimentais/metabolismo , Camundongos , Camundongos Nus , Presenilina-2/genética , Presenilina-2/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Fator de Crescimento Transformador alfa/genética , Fator de Crescimento Transformador alfa/metabolismo
3.
Curr Gene Ther ; 8(1): 24-41, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18336247

RESUMO

The treatment of rheumatoid arthritis (RA) in the last decade has made enormous advances with the use of biological therapies. However, these therapies have serious limitations such as the expense, side-effects, and the requirement for repeated injections, each of which can potentially be obviated by gene therapy. A gene therapy approach for the treatment of RA has the potential to stably deliver a gene product or multiple products in a target-specific, disease-inducible manner. There are many studies investigating gene therapy in RA, the majority of which have been designed to test proof-of-principle in an animal model. With an abundance of animal studies that have established much promise, the field is now at the early stage of moving towards human trials, where patient benefit needs to overshadow associated risks, especially since RA is publicly perceived as a non-life-threatening disease. Here, we provide an overview that focuses on advances in the application of gene therapy to RA over the last five years, including: novel targets and approaches; the viral and non-viral applications most likely to succeed in the clinic; advances in our understanding of the contralateral effect; the latest successes with anti-inflammatory cytokines; and a review of advancements towards clinical trials.


Assuntos
Artrite Reumatoide/terapia , Terapia Genética/métodos , Animais , Artrite Reumatoide/genética , Humanos
4.
DNA Cell Biol ; 26(9): 673-82, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17691867

RESUMO

Cathepsin B contributes to the invasiveness of B16 melanoma cells in mice, with the highly metastatic B16a melanoma producing six- to eightfold more cathepsin B mRNA and protein than the less metastatic B16F1 variant. The proximal promoter region of the cathepsin B (Ctsb) gene (-149 to +94) was previously found to be capable of reproducing this pattern of differential gene activation in B16 melanoma variants. The binding of B16 melanoma nuclear proteins to this promoter region has now been mapped to three GC-boxes (Sp1 transcription factor binding sites) and a potential X-box [tax response element (TRE)/c-AMP responsive element (CRE) site]. Mutation of the GC-boxes at -55 and -37 independently decreased the expression of a luciferase reporter gene in B16a cells to the level observed in B16F1 cells. Promoter activity was also attenuated by mutations within the GC-rich segment between +6 and +16, but not by mutation of the putative X-box. Both Sp1 and Sp3 bound the GC-boxes in the Ctsb promoter, and western blotting showed the level of Sp1 to be greater in B16a compared to B16F1 cells. B16F1 cells that were made to express Sp1 at levels observed in B16a cells produced corresponding increased amounts of endogenous cathepsin B mRNA and enzyme activity. Thus, the difference in cathepsin B expression between high and low metastatic B16 melanoma variants is largely due to different levels of Sp1.


Assuntos
Catepsina B/genética , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Melanoma Experimental/genética , Fator de Transcrição Sp1/metabolismo , Animais , Composição de Bases , Sequência de Bases , Sítios de Ligação , Catepsina B/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Melanoma Experimental/enzimologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Elementos de Resposta , Deleção de Sequência , Fator de Transcrição Sp3/metabolismo , Transcrição Gênica , Ativação Transcricional , Transfecção , Células Tumorais Cultivadas
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