RESUMO
El Síndrome de Down es una enfermedad genética causada por trisomía del par 21. Actualmente existe la posibilidad de ofrecer diagnóstico prenatal de esta entidad mediante procedimientos no invasivos como la medición de hormonas maternas específicas durante el 1er y 2do trimestre de gestación y el estudio ecográfico del feto en busca de malformaciones, así como a través de procedimientos invasivos (amniocentesis) para cariotipo fetal o pruebas moleculares dirigidas. El diagnóstico prenatal se basa en la utilización conjunta de estos marcadores más la edad materna para evaluar el riesgo en un feto de tener anomalías congénitas (síndrome de Down y otros). La presente investigación describe la utilidad de la correlación sérica, ecográfica, citogenética y molecular de los marcadores prenatales de síndrome de Down. Se trata de una paciente de 21 años primigesta (16 semanas de gestación) con datos séricos y ecográficos compatibles con una cromosomopatía, la amniocentesis diagnóstica permitió obtener material genético del feto para análisis citogenético y caracterización molecular, con un cariotipo 47,XY,+21. De manera que se ilustra la relevancia de la evaluación integral en el diagnóstico prenatal, así como el enfoque multidisciplinario.
Down syndrome (DS) is a genetic disease caused by 21 chromosome, we have now the possibility to offer prenatal diagnosis by non-invasive procedures such as: serum measurement of maternal hormones during the first and second trimester of pregnancy and the fetus ultrasound study searching for malformations, and by invasive procedures like amniocentesis for fetal karyotype or directed molecular test. Prenatal diagnosis is based on combined use of these markers to assess the risk of having fetus with congenital abnormalities (Down syndrome and others). We describe the utility of serum, ultrasound, cytogenetic and molecular correlation like markers of prenatal Down syndrome. The case of a 21 year old female primigravida with 16 weeks pregnancy and serum plus ultrasound data consistent with a chromosomal abnormality. Diagnostic amniocentesis was performed also to obtain fetal genetic for cytogenetic study and molecular characterization), with a fetal karyotype 47,XY,+21. Therefore, importance of comprehensive assessment in prenatal diagnosis and the multidisciplinary approach.
Assuntos
Síndrome de DownRESUMO
CoA is required for many synthetic and degradative reactions in intermediary metabolism and is the principal acyl carrier in prokaryotic and eukaryotic cells. CoA is synthesized in five steps from pantothenate, and recently, the CoA biosynthetic genes of Arabidopsis have all been identified and characterized. Here, we demonstrate the biochemical and physiological characterization of a pyrophosphatase from Arabidopsis thaliana, called AtCoAse (locus tag At5g45940), cleaving CoA to 4'-phosphopantetheine and 3',5'-adenosine-diphosphate in the presence of Mg2+/Mn2+ ions. The CoA cleaving enzyme isa member of the Nudix hydrolases, pyrophosphatases that hydrolyze nucleoside diphosphates, already described as CoAse and now further characterized in detail by us. Mutagenesis of residues of the so-called Nudix and NuCoA motifs drastically reduced the hydrolase activity. AtCoAse is not absolute specific for CoA, and in the presence of Mn2+ ions, a minor hydrolyzing activity was observed with NADH as substrate. The AtCoAse expression is ubiquitous, strongly in flower and unaffected by abiotic stress. The immunohistochemical localization indicates that the AtCoAse protein is observed in the cytoplasm of distinct cells types from different heterotrophic Arabidopsis tissues, mainly restricted to the vascular elements of the root and shoot and in flower and developing embryo. Transgenic Arabidopsis plants, with increased AtCoAse expression, show altered growth rates and development, expanding their live cycle far away from the wild-type.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Coenzima A/metabolismo , Pirofosfatases/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/isolamento & purificação , Clonagem Molecular , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Pirofosfatases/genética , Pirofosfatases/isolamento & purificação , RNA de Plantas/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Nudix HidrolasesRESUMO
An extract of leaves and stems of Peperomia villipetiola has been found to contain myristicin (3-methoxy-4,5-methylenedioxy-allylbenzene) and seven chromenes, whose structures are methyl 5-hydroxy-7-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (1), methyl 5-methoxy-7-methyl-2,2-dimethyl-2H-1-chromene-8-carboxylate (2), methyl 7-hydroxy-5-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (3), methyl 7-methoxy-5-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (4), 5-methanol-7-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylic acid (5), 5-methanol-7-methoxy-2,2-dimethyl-2H-1-chromene-6-carboxylic acid (6), and methyl 5-acetoxymethanol-7-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate (7). A biosynthetic rationale for 1-7 suggests that orsellinic acid may be a common intermediate. The anti-fungal activities of the chromenes were measured bioautographically against Cladosporium cladosporioides and Cladosporium sphaerospermum: compounds 6 and 7 were found to be the most active.
