39 research outputs found

    ¿Qué es y cómo opera la evaluación en el aula de Química, según docentes en ejercicio? entre el discurso y la práctica

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    En esta investigación nos propusimos comprender las finalidades de las prácticas evaluativas de profesores de Química en ejercicio de Enseñanza Media, con el fin de entregar un aporte a la comunidad docente para desarrollar competencias de pensamiento científico. ¿qué y cuáles con las finalidades de las prácticas evaluativas de los profesores de Química en ejercicio?, ¿Cuáles son las concepciones teóricas sobre evaluación de aprendizajes en la clase de química? ¿Qué tipos de estrategias evaluativas e instrumentos utilizan los profesores de Química en ejercicio? La búsqueda de respuestas a estas preguntas a través de una investigación y su posterior análisis documentado entrega un aporte al conocimiento teórico, teniendo presente al proceso de evaluación como una herramienta al servicio del aprendizaje científico

    Optimizing CIGB-300 intralesional delivery in locally advanced cervical cancer

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    Background:We conducted a phase 1 trial in patients with locally advanced cervical cancer by injecting 0.5 ml of the CK2-antagonist CIGB-300 in two different sites on tumours to assess tumour uptake, safety, pharmacodynamic activity and identify the recommended dose.Methods:Fourteen patients were treated with intralesional injections containing 35 or 70 mg of CIGB-300 in three alternate cycles of three consecutive days each before standard chemoradiotherapy. Tumour uptake was determined using 99 Tc-radiolabelled peptide. In situ B23/nucleophosmin was determined by immunohistochemistry.Results:Maximum tumour uptake for CIGB-300 70-mg dose was significantly higher than the one observed for 35 mg: 16.1±8.9 vs 31.3±12.9 mg (P=0.01). Both, AUC 24h and biological half-life were also significantly higher using 70 mg of CIGB-300 (P<0.001). Unincorporated CIGB-300 diffused rapidly to blood and was mainly distributed towards kidneys, and marginally in liver, lungs, heart and spleen. There was no DLT and moderate allergic-like reactions were the most common systemic side effect with strong correlation between unincorporated CIGB-300 and histamine levels in blood. CIGB-300, 70 mg, downregulated B23/nucleophosmin (P=0.03) in tumour specimens.Conclusion:Intralesional injections of 70 mg CIGB-300 in two sites (0.5 ml per injection) and this treatment plan are recommended to be evaluated in phase 2 studies.Fil: Sarduy, M. R.. Medical-surgical Research Center; CubaFil: García, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Coca, M. A.. Clinical Investigation Center; CubaFil: Perera, A.. Clinical Investigation Center; CubaFil: Torres, L. A.. Clinical Investigation Center; CubaFil: Valenzuela, C. M.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Baladrón, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Solares, M.. Hospital Materno Ramón González Coro; CubaFil: Reyes, V.. Center For Genetic Engineering And Biotechnology Havana; CubaFil: Hernández, I.. Isotope Center; CubaFil: Perera, Y.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Martínez, Y. M.. Medical-surgical Research Center; CubaFil: Molina, L.. Medical-surgical Research Center; CubaFil: González, Y. M.. Medical-surgical Research Center; CubaFil: Ancízar, J. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Prats, A.. Clinical Investigation Center; CubaFil: González, L.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Casacó, C. A.. Clinical Investigation Center; CubaFil: Acevedo, B. E.. Centro de Ingeniería Genética y Biotecnología; CubaFil: López Saura, P. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes; ArgentinaFil: Gómez, R.. Elea Laboratories; ArgentinaFil: Perea Rodríguez, S. E.. Center For Genetic Engineering And Biotechnology Havana; Cuba. Centro de Ingeniería Genética y Biotecnología; Cub

    Therapeutic targeting of CK2 in acute and chronic leukemias

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    Phosphorylation can regulate almost every property of a protein and is involved in all fundamental cellular processes. Thus, proper regulation of phosphorylation events is critical to the homeostatic functions of cell signaling. Indeed, deregulation of signaling pathways underlies many human diseases, including cancer.[1] The importance of phosphorylation makes protein kinases and phosphatases promising therapeutic targets for a wide variety of disorders.[2] CK2, formerly known as casein kinase II, was discovered in 1954, [3] although only recently, and especially over the last two decades, it has become one of the most studied protein kinases, due to its ubiquity, pleiotropy and constitutive activity. In particular, appreciation of its pleiotropy has completely changed our vision of CK2 biology, from an ordinary cell homeostasis-maintaining enzyme to a master kinase potentially implicated in many human physiological and pathological events. CK2 is responsible for about 25% of the phosphoproteome,[4] as it catalyzes the phosphorylation of >300 substrates.[5] This partly explains the CK2 interconnected roles that underlie its involvement in many signaling pathways. However, CK2 prevalent roles are promotion of cell growth and suppression of apoptosis. Accordingly, several lines of evidence support the notion that CK2 is a key player in the pathogenesis of cancer. High levels of CK2 transcript and protein expression, as well as increased kinase activity are associated with the pathological functions of CK2 in a number of neoplasias.[6] It was only over the last decade, after extensive analyses in solid tumors, that basic and translational studies have provided evidence for a pivotal role of CK2 in driving the growth of different blood cancers as well, although the first report demonstrating increased CK2 expression in acute myelogenous leukemia (AML) dates back to 1985.[7] Since then, CK2 overexpression/activity has been demonstrated in other hematological malignancies, including acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL) and chronic myelogenous leukemia (CML). [8] With the notable exceptions of CML and pediatric ALL, many patients with leukemias still have a poor outcome, despite the development of protocols with optimized chemotherapy combinations. Insufficient response to first-line therapy and unsalvageable relapses present major therapeutic challenges. Moreover, chemotherapy, even if successful, could have deleterious long-term biological and psychological effects, especially in children.[9] Furthermore, CML patients can develop resistance to tyrosine kinase inhibitors (TKIs), while both primary chemoresistant and relapsed pediatric ALL cases still remain an unresolved issue.[9

    La psicología educacional y el sistema de educación en Cuba

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    Interleukin 2 immune response generating formulation, used for treating cancer, comprises IL 2 coupled to transport protein, monoclonal anti IL 2 antibody or monoclonal anti CD 25 antibody

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    NOVELTY - A formulation comprising one or more components chosen from interleukin (IL)-2 or a derivative thereof coupled to a transport protein, a monoclonal anti-IL-2 antibody, a cancer vaccine based on specific antigens of tumors or tumor growth factors or a monoclonal anti-CD25 antibody, is new. USE - The formulations are used to produce drugs for inducing an anti-IL-2 immune response capable of inhibiting the growth of tumors in cancer patients (claimed). ADVANTAGE - Auto-antibodies which block binding of IL-2 to its receptor are induced and inhibit tumor growth. DETAILED DESCRIPTION - A therapeutic formulation capable of generating an immune response to Interleukin 2 (IL-2), used for treating cancer patients, comprises at least one component chosen from: (a) IL-2 or a derivative thereof coupled to a transport protein genetically or by chemical bonding, as well as a suitable adjuvant; (b) a monoclonal anti-IL-2 antibody; (c) a cancer vaccine based on specific antigens of tumors or tumor growth factors; or (d) a monoclonal anti-CD25 antibody

    Tropane alkaloids from the leaves and stem bark of Erythroxylon alaternifolium and Erythroxylon rotundifolium

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    Abstract: A novel 3α,6β,7β-triol tropanealkaloid esterified by two benzoyl residues was isolated from the leaves of the endemic cuban species, Erythroxylonalaternifolium. Another novel 3α,6α,7β-triol tropanealkaloid esterified by trimethoxycinnamoyl and trimethoxybenzoyl residues was isolated from the leaves and stembark of a second endemic cuban species, Erythroxylonrotundifolium. Their structures were elucidated as 3α,7β-dibenzoyloxy-6β-hydroxy-tropane and 3α-(3,4,5-trimethoxy-cinnamoyloxy)-7β-(3,4,5-trimethoxybenzoyloxy)-6α-hydroxy-tropane by spectroscopic methods including 2D-NMR techniques

    Real-time monitoring of protein conformational changes using a nano-mechanical sensor.

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    Proteins can switch between different conformations in response to stimuli, such as pH or temperature variations, or to the binding of ligands. Such plasticity and its kinetics can have a crucial functional role, and their characterization has taken center stage in protein research. As an example, Topoisomerases are particularly interesting enzymes capable of managing tangled and supercoiled double-stranded DNA, thus facilitating many physiological processes. In this work, we describe the use of a cantilever-based nanomotion sensor to characterize the dynamics of human topoisomerase II (Topo II) enzymes and their response to different kinds of ligands, such as ATP, which enhance the conformational dynamics. The sensitivity and time resolution of this sensor allow determining quantitatively the correlation between the ATP concentration and the rate of Topo II conformational changes. Furthermore, we show how to rationalize the experimental results in a comprehensive model that takes into account both the physics of the cantilever and the dynamics of the ATPase cycle of the enzyme, shedding light on the kinetics of the process. Finally, we study the effect of aclarubicin, an anticancer drug, demonstrating that it affects directly the Topo II molecule inhibiting its conformational changes. These results pave the way to a new way of studying the intrinsic dynamics of proteins and of protein complexes allowing new applications ranging from fundamental proteomics to drug discovery and development and possibly to clinical practice
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