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2009-06-01
Resumen en español La proteína verde fluorescente (o GFP, por sus siglas en inglés, Green Fluorescent Protein) es una proteína producida por la medusa Aequorea victoria que emite bioluminiscencia en la zona verde del espectro visible. El gen que codifica esta proteína ha sido clonado y se utiliza habitualmente en biología molecular como marcador. Los descubrimientos relacionados a la GFP merecieron el Premio Nobel de Química 2008, en conjunto a los tres investigadores, Dres Shimomura, (mas) Chalfie y Tsien que participaron escalonadamente en dilucidar la estructura y función de la proteína. El Dr. Shimomura descubrió y estudió las propiedades de GFP, el Dr. Chalfie usando técnicas de biología molecular logró introducir el gen que codificaba para la GFP en el ADN del gusano transparente C. elegans, e inició la era de GFP como marcador de procesos en células y organismos. Finalmente el Dr. Tsien modificó la estructura de la proteína para producir moléculas que emiten luz a distintas longitudes de onda, extendiendo la paleta de colores de las proteínas. Las proteínas fluorescentes, entre las cuales se encuentra la GFP, son muy versátiles y se utilizan en diversos campos como la microbiología, ingeniería genética, fisiología, e ingeniería ambiental. Permiten ver procesos previamente invisibles, como el desarrollo de neuronas, cómo se diseminan las células cancerosas, o la contaminación de agua con arsénico, por mencionar algunos usos. Con la obtención de proteínas de muchos colores complejas redes biológicas pueden ser marcadas diferencialmente, lo que permite visualizar la biología celular en acción. Resumen en inglés Green fluorescent protein (GFP) is a protein produced by the jellyfish Aequorea victoria, that emits bioluminescence in the green zone of the visible spectrum. The GFP gene has been cloned and is used in molecular biology as a marker. The three researchers that participated independently in elucidating the structure and function of this and its related proteins, Drs. Shimomura, Chalfie and Tsien were awarded the Nobel Prize in Chemistry 2008. Dr. Shimomura discovered and (mas) studied the properties of GFP. Using molecular biological techniques, Chalfie succeeded in introducing the GFP gene into the DNA of the small, almost transparent worm C. elegans, and initiated an era in which GFP would be used as a glowing marker for cellular biology. Finally, Dr.Tsien found precisely how GFP's structure produces the observed green fluorescence, and succeeded in modifying the structure to generate molecules that emit light at slightly different wavelengths, which gave tags of different colors. Fluorescent proteins are very versatile and are being used in many areas, such as microbiology, biotechnology, physiology, environmental engineering, development, etc. They can, for example, illuminate growing cancer tumours; show the development of Alzheimer's disease, or detect arsenic traces in water. Finding the key to how a marine organism produces light unexpectedly ended up providing researchers with a powerful array of tools with which to visualize cell biology in action.
2004-12-01
Resumen en español En conjunto, las agenesias dentarias son la malformación cráneofacial más frecuente. Su prevalencia alcanza el 20% en la dentición permanente, y su expresión puede variar desde la ausencia de una sola pieza, generalmente un tercer molar, hasta la de toda la dentición. En la pasada década, los estudios de ligamiento genético y biología molecular han permitido identificar algunas mutaciones responsables de distintos patrones de agenesias dentarias sindrómicas y no (mas) sindrómicas. Dichas mutaciones se encuentran en genes clave para el desarrollo de la dentición, como los que codifican a los factores de transcripción MSX1, PAX9 y PITX2, la proteína de señalización EDA y su receptor EDAR. Los estudios que están en curso podrían derivar en nuevas clasificaciones que relacionen los fenotipos observados con el defecto genético subyacente. De esta manera, se posibilitaría un diagnóstico previo a la aparición del defecto somático, que técnicas como la terapia génica o la ingeniería de tejidos y órganos, podrían llegar a solucionar. Resumen en inglés Tooth agenesis are the most common craniofacial malformations. Its prevalence in permanent dentition reaches 20% and its expressivity ranges from only one tooth, usually a third molar, to the whole dentition. Genetic linkage and molecular biology studies have allowed, in the last decade, the identification of mutations responsible for some patterns of syndromic and non-syndromic tooth agenesis. The mutated genes are key genes for the development of dentition, like the one (mas) s that encode the transcription factors MSX1, PAX9 and PITX2, the signalling protein EDA and its receptor EDAR. Current research would lead to the development of new classifications of tooth agenesis that took into account both the phenotypes and the genetic background. This would allow an early diagnosis of the condition, before the development of the somatic defect, that could eventually be repaired with gene therapy or tissue and organ engineering.
2007-03-01
Resumen en español Se efectuó una revisión sobre el síndrome frágil X, del cual en Cuba no existían reportes desde el punto de vista poblacional, hasta la realización del estudio psicopedagógico, social y clínico genético de las personas con retraso mental; mediante el cual pudo detectarse un total de 75 personas con defectos del gen FMR-1, que es el gen relacionado con esta enfermedad. Es un síndrome causado en la gran mayoría de los casos por la amplificación o mutación diná (mas) mica de las repeticiones del trinucleótido citosina-guanina-guanina (CGG) en la región promotora del gen FMR-1. La traducción de este gen da lugar a una proteína denominada FMRP. Se plantea que la ausencia o deficiencia de esta proteína ocasiona modificaciones de la actividad neuronal. Hoy día no hay cura para el síndrome frágil X, aunque se están desarrollando experimentos basados tanto en la terapia como la ingeniería genética, consistentes en reproducir la carencia de la proteína causante de la enfermedad. El tratamiento médico se limitará a reducir y palear todos los síntomas que pueden observarse en este síndrome. La temprana identificación del síndrome frágil X, resulta muy beneficiosa para los padres y la familia del paciente; pues reduce el impacto psicológico inicial y propicia que se apliquen programas de intervención precoz; proporcionando una mejor comprensión de la historia natural de la enfermedad y el estudio genético entre otros aspectos Resumen en inglés It was made a review of the Fragile X Syndrome, of which there were no reports in Cuba from the population point of view, until a psychopedagogical, social and clinico-genetic study of the persons with mental retardation was undertaken. 75 persons with defects of the FMR-1 gene, that is the gene related to this disease, were detected. It is a syndrome caused in most of the cases by the dynamic amplification or mutation of the repetitions of the cytosine-guanine-guanine (C (mas) GG) trinucleotide in the promoter region of the FMR-1gene. The translation of this gene gives rise to a protein denominated FMRP. It is stated that the absence or deficiency of this protein produces modifications of the neuronal activity. Today, there is no cure for the Fragile X Syndrome, eventhough experiments based on the therapy and genetic engineering are being developed to reproduce the lack of the protein causing the disease. The medical treatment will llimit itself to reduce and palliate all the symptoms that may be observed in this syndrome. The early identification of the Fragile X Syndrome is very benefitial for the parents and the family of the patient, since it diminishes the initial psychological impact and propitiates the implementation of early intervention programs, allowing a better comprehension of the natural history of the disease and the genetic study, among other aspects.
The final version of record is available at: http://www.biochemj.org/bj/default.htm | We report the isolation and amino acid sequences of six novel dimeric disintegrins from the venoms of Vipera lebetina obtusa (VLO), V. berus (VB), V. ammodytes (VA), Echis ocellatus (EO) and Echis multisquamatus (E...
2008-01-01
Resumen en inglés Current strategies to treat type 2 diabetes (DMT2) include reducing insulin resistance using glitazones, supplementing with exogenous insulin, increasing endogenous insulin production with sulfonylureas and meglitinides, reducing hepatic glucose production through biguanides, and limiting postprandial glucose absorption with alpha-glucosidase inhibitors. In all of these areas, new generations of molecules with improved efficacy and safety profiles, are being investigated. (mas) Promising biological targets are rapidly emerging such as the role of lipotoxicity as a cause of glucometabolic insulin resistance, leading to a host of new molecular drug targets such as AMP-activated protein kinase (AMPK) activators, recombinant adiponectin derivatives, and fatty acid synthase (FAS) inhibitors. Insulin action can be enhanced in muscle, liver and fat, with small-molecule activators of the insulin receptor or inhibitors of protein tyrosine phosphatase (FTP)-IB. Defective glucose-stimulated insulin secretion by pancreatic B-cells could be alleviated with recombinant glucagon-like peptide (GLP-1) or agonists to the GLP-1 receptor. This review presents a new approach for obesity and DMT2 drug discovery through pharmacogenomics. Several compounds have already been validated through genetic engineering in animal models or the preliminary use of therapeutic compounds in humans (Rev Méd Chile 2008; 136:107-17)
2003-12-01
Resumen en inglés The fusion of a murine B cell and a myeloma cell generates a hybridoma that produces monoclonal antibody (mAb). These murine mAb induce the HAMA (human anti-mouse antibodies) response. Murine mAb have been modified by genetic engineering, producing molecules with a higher proportion of human protein. At present, chimeric, humanized and fully human mAb are available. mAb block interactions between target molecules and their ligands or trigger the lyses of mAb-coated tumor (mas) cells. Numerous mAb have been developed using the recombinant DNA technology and several are available in the market. Trastuzumab, against HER2/neu, is useful in breast cancer; rituximab, against CD20 in B lymphocytes is useful in lymphoma; alemtuzumab, against CD52 is used in lymphoma and leukemia; daclizumab and basiliximab block the IL-2 receptor interaction and reduce acute rejection in kidney transplantion; abciximab, an antagonist of GPIIb/IIIa platelet receptor, is used in patients undergoing acute coronary syndromes. In autoimmunity diseases, blocking tumor necrosis factor by infliximab and adalimumab has demonstrated excellent results. Thus, infliximab is useful in the treatment of rheumatoid arthritis (RA), Crohn's disease and ulcerative colitis while adalimumab is the first fully human mAb available for RA. Infliximab and adalimumab reduce signs and symptoms in RA and they also interfere with progression of joint damage. Finally, the direct benefits of antagonist treatment can occur at the expense of a major adverse effect in some other biological function (Rev Méd Chile 2003; 131: 1445-53)
Establecimiento de un material de referencia de trabajo para interleucina-2 recombinante
2005-08-01
Resumen en español Resumen La interleucina-2 es una glicoproteína humana de 133 aminoácidos que resulta vital para obtener una respuesta inmunológica efectiva. En el Centro de Ingeniería Genética y Biotecnología ha podido obtenerse por vía recombinante a partir de una cepa de Escherichia coli. Para el control de la calidad de cada lote producido se hizo necesaria la elaboración de un material de referencia de trabajo. En esta publicación se describen los pasos seguidos en la obtenc (mas) ión del lote candidato y la preparación del material de referencia como tal. Se demostró que el patrón de trabajo preparado es homogéneo para el uso en las técnicas analíticas de control de calidad de la interleucina-2 y se predijo una pérdida de actividad inferior al 5 % anual mediante un estudio de estabilidad acelerada. Se obtuvieron valores adecuados para la pureza del material de referencia, evaluada por electroforesis y para la actividad biológica, que se estableció con trazabilidad al material de referencia internacional para este producto. Resumen en inglés Establishment of a working reference material for recombinant interleukin-2 Interleukin-2 is a human glycoprotein with 133 aminoacids that is crucial for attaining an effective immunological reaction. In the Center of Genetic Engineering and Biotechnology this protein has been obtained as a recombinant product from Eschericia coli bacteria. For the quality control of every batch produced, it was necessary to establish a working reference material. In this paper we describ (mas) e the steps taken to obtain a candidate batch and the preparation of the working material as such. It was proved that the working pattern obtained.is homogenous for its use in the analytical techniques of quality control of interleukin-2. A loss of activity lower than an annual 5 % was predicted by an accelerated stability study. Adequate values were attained for the purity of the reference material, evaluated by electrophoresis, and for the biological activity that was established with traceability to the international reference material for this product.
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