947 resultados para sickle cell anemia studies
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Introducción: actualmente la anemia y la obesidad durante el embarazo se consideran factores de riesgo modificables para hemorragia postparto. Estos pueden ser evitados desde el control prenatal y su manejo preconcepcional contribuye de una forma importante en la reducción de la morbimortalidad materno y perinatal. Metodología: se realizó una revisión sistemática de literatura con componente meta-analítico según la evidencia disponible hasta la fecha. Los términos mesH incluyeron postpartum hemorrhage, severe anemia, overweight, obesity entre otros. Todos los artículos fueron clasificados por su evidencia antes de calcular el componente meta-analítico. Resultados: se encontraron un total de 321 artículos relacionados con anemia, y 276 para obesidad, de los cuales 8 y 14 respectivamente cumplieron criterios para su selección. La mayoría de artículos fueron clasificados como evidencia IV para anemia y II-III para obesidad. Las causas más frecuentes de exclusión fueron el título y el tipo de estudio. Tanto la anemia como la obesidad (clasificada por IMC) muestran OR conjuntos no estadísticamente significativo y con intervalos de confianza amplios, aunque la tendencia de riesgo conjunto es a mayor peso, mayor riesgo de hemorragia. Discusión: los resultados de la revisión sistemática permiten mostrar tanto a la anemia como la obesidad como factores que muestran una tendencia al riesgo para hemorragia postparto, sin resultados estadísticamente significativos. Faltan más estudios sobre el tema en el país.MetodologíaSe realizó una revisión sistemática de literatura con componente meta-analítico según la evidencia disponible hasta la fecha. Los términos mesH incluyeron postpartum hemorrhage, severe anemia, overweight, obesity entre otros. Todos los artículos fueron clasificados por su evidencia antes de calcular el componente meta-analítico. ResultadosSe encontraron un total de 321 artículos relacionados con anemia, y 276 para obesidad, de los cuales 8 y 14 respectivamente cumplieron criterios para su selección. La mayoría de artículos fueron clasificados como evidencia IV para anemia y II-III para obesidad. Las causas más frecuentes de exclusión fueron el título y el tipo de estudio. Tanto la anemia como la obesidad (clasificada por IMC) muestran OR conjuntos no estadísticamente significativo y con intervalos de confianza amplios, aunque la tendencia de riesgo conjunto es a mayor peso, mayor riesgo de hemorragia. DiscusiónLos resultados de la revisión sistemática permiten mostrar tanto a la anemia como la obesidad como factores que muestran una tendencia al riesgo para hemorragia postparto, sin resultados estadísticamente significativos. Faltan más estudios sobre el tema en el país.
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El marcaje de proteínas con ubiquitina, conocido como ubiquitinación, cumple diferentes funciones que incluyen la regulación de varios procesos celulares, tales como: la degradación de proteínas por medio del proteosoma, la reparación del ADN, la señalización mediada por receptores de membrana, y la endocitosis, entre otras (1). Las moléculas de ubiquitina pueden ser removidas de sus sustratos gracias a la acción de un gran grupo de proteasas, llamadas enzimas deubiquitinizantes (DUBs) (2). Las DUBs son esenciales para la manutención de la homeostasis de la ubiquitina y para la regulación del estado de ubiquitinación de diferentes sustratos. El gran número y la diversidad de DUBs descritas refleja tanto su especificidad como su utilización para regular un amplio espectro de sustratos y vías celulares. Aunque muchas DUBs han sido estudiadas a profundidad, actualmente se desconocen los sustratos y las funciones biológicas de la mayoría de ellas. En este trabajo se investigaron las funciones de las DUBs: USP19, USP4 y UCH-L1. Utilizando varias técnicas de biología molecular y celular se encontró que: i) USP19 es regulada por las ubiquitin ligasas SIAH1 y SIAH2 ii) USP19 es importante para regular HIF-1α, un factor de transcripción clave en la respuesta celular a hipoxia, iii) USP4 interactúa con el proteosoma, iv) La quimera mCherry-UCH-L1 reproduce parcialmente los fenotipos que nuestro grupo ha descrito previamente al usar otros constructos de la misma enzima, y v) UCH-L1 promueve la internalización de la bacteria Yersinia pseudotuberculosis.
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Introducción: En los pacientes críticamente enfermos la terapia transfusional es una práctica común. Dentro de los estudios realizados no se han incluido a las ciudades a mayor altura. Este estudio pretende determinar los niveles de hemoglobina sobre los cuales se está transfundiendo a los pacientes en la unidad de cuidados intensivos del Hospital Universitario Fundación Santa Fe de Bogotá a 2600 metros sobre el nivel del mar, para determinar si los niveles de hemoglobina a los que se transfunde a nuestra altura son los óptimos. Métodos: Se realizó un estudio descriptivo retrospectivo, de los pacientes que fueron hospitalizados en la Unidad de Cuidado Intensivo del Hospital Universitario Fundación Santa Fe de Bogotá a partir del 01 de Junio de 2011 y hasta el 31 de Mayo de 2012. Resultados: Del total de los registros analizados el 13,8% de los pacientes presentaron una hemoglobina ≤ 7 y todos fueron transfundidos con glóbulos rojos; y en el rango de 7,1-9 se presentó el mayor porcentaje de transfusión. Se observó que los pacientes con hemoglobina ≤ 7 tienen 18,8 veces mayor riego de fallecimiento, lo que fue estadísticamente significativo (p:0,000). Conclusiones: Encontramos que la terapia transfusional en la unidad de cuidado intensivo, se realiza de acuerdo a recomendaciones dadas por las guías de manejo universalmente aceptadas. Dentro de los resultados de nuestro estudio podemos resaltar una tasa de mortalidad más alta en los pacientes en los cuales se instaura terapia transfusional con un nivel de hemoglobina por debajo de 7g/dl.
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We previously established an 80 kb haplotype upstream of TNFSF4 as a susceptibility locus in the autoimmune disease SLE. SLE-associated alleles at this locus are associated with inflammatory disorders, including atherosclerosis and ischaemic stroke. In Europeans, the TNFSF4 causal variants have remained elusive due to strong linkage disequilibrium exhibited by alleles spanning the region. Using a trans-ancestral approach to fine-map the locus, utilising 17,900 SLE and control subjects including Amerindian/Hispanics (1348 cases, 717 controls), African-Americans (AA) (1529, 2048) and better powered cohorts of Europeans and East Asians, we find strong association of risk alleles in all ethnicities; the AA association replicates in African-American Gullah (152,122). The best evidence of association comes from two adjacent markers: rs2205960-T (P = 1.71×10-34, OR = 1.43[1.26-1.60]) and rs1234317-T (P = 1.16×10-28, OR = 1.38[1.24-1.54]). Inference of fine-scale recombination rates for all populations tested finds the 80 kb risk and non-risk haplotypes in all except African-Americans. In this population the decay of recombination equates to an 11 kb risk haplotype, anchored in the 5′ region proximal to TNFSF4 and tagged by rs2205960-T after 1000 Genomes phase 1 (v3) imputation. Conditional regression analyses delineate the 5′ risk signal to rs2205960-T and the independent non-risk signal to rs1234314-C. Our case-only and SLE-control cohorts demonstrate robust association of rs2205960-T with autoantibody production. The rs2205960-T is predicted to form part of a decameric motif which binds NF-κBp65 with increased affinity compared to rs2205960-G. ChIP-seq data also indicate NF-κB interaction with the DNA sequence at this position in LCL cells. Our research suggests association of rs2205960-T with SLE across multiple groups and an independent non-risk signal at rs1234314-C. rs2205960-T is associated with autoantibody production and lymphopenia. Our data confirm a global signal at TNFSF4 and a role for the expressed product at multiple stages of lymphocyte dysregulation during SLE pathogenesis. We confirm the validity of trans-ancestral mapping in a complex trait. © 2013 Manku et al.
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Introduction Fanconi anemia is an autosomal recessive disease characterized by a variety of congenital abnormalities, progressive bone marrow failure, increased chromosomal instability and higher risk to acute myeloid leukemia, solid tumors. This entity can be considered an appropriate biological model to analyze natural substances with possible genotoxic effect. The aims of this study were to describe and quantify structural chromosomal aberrations induced by 5 flavones, 2 isoflavones and a topoisomerase II chemotherapeutic inhibitor in Fanconi anemia lymphocytes in order to determine chromosomal numbers changes and/ or type of chromosomal damage. Materials and methods Chromosomes stimulated by phytohaemagglutinin M, from Fanconi anemia lymphocytes, were analysed by conventional cytogenetic culture. For each chemical substance and controls, one hundred metaphases were evaluated. Chromosomal alterations were documented by photography and imaging analyzer. To statistical analysis was used chi square test to identify significant differences between frequencies of chromosomal damage of basal and exposed cell cultured a P value less than 0.05. Results There were 431 chromosomal alterations in 1000 metaphases analysed; genistein was the more genotoxic bioflavonoid, followed in descendent order by genistin, fisetin, kaempferol, quercetin, baicalein and miricetin. Chromosomal aberrations observed were: chromatid breaks, chromosomal breaks, cromatid and chromosomal gaps, quadriratials exchanges, dicentrics chromosome and complex rearrangements. Conclusion Bioflavonoids as genistein, genistin and fisetin, which are commonly present in the human diet, showed statistical significance in the number of chromosomal aberrations in Fanconi anemia lymphocytes, regarding the basal damage.
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This paper investigates the relationship between hair cell proliferation and immunosuppression in chicks.
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The goal of the present study was to compare aging characteristics of the cochlear lateral wall in inbred mouse strains (CBA/J and CBA/CaJ) having very different endocochlear potential (EP)-versus-age profiles to see which anatomic differences might predict their EP differences.
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Hair cell death and regeneration on the zebrafish posterior lateral line was investigated after cisplatin administration. Hair cell regeneration was first observed by 24 hours of recovery and was further analyzed after specific recovery intervals. Disruption of the notch signaling pathways by the y-secretase inhibitor DAPT resulted in an increase in hair cells at three days of recovery.
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The L-glutamate transporter GLT-1 is an abundant CNS membrane protein of the excitatory amino acid transporter (EAAT) family which controls extracellular L-glutamate levels and is important in limiting excitotoxic neuronal death. Using RT-PCR, we have determined that four mRNAs encoding GLT-1 exist in mouse brain, with the potential to encode four GLT-1 isoforms that differ in their N- and C-termini. We expressed all four isoforms (termed MAST-KREK, MPK-KREK, MAST-DIETCI and MPK-DIETCI according to amino acid sequence) in a range of cell lines and primary astrocytes and show that each isoform can reach the cell surface. In transfected HEK-293 or COS-7 cells, all four isoforms support high-affinity sodium-dependent L-glutamate uptake with identical pharmacological and kinetic properties. Inserting a viral epitope (V5, HA or FLAG) into the second extracellular domain of each isoform allowed co-immunoprecipitation and tr-FRET studies using transfected HEK-293 cells. Here we show for the first time that each of the four isoforms are able to combine to form homomeric and heteromeric assemblies, each of which are expressed at the cell surface of primary astrocytes. After activation of protein kinase C by phorbol ester, V5-tagged GLT-1 is rapidly removed from the cell surface of HEK-293 cells and degraded. This study provides direct biochemical evidence for oligomeric assembly of GLT-1 and reports the development of novel tools to provide insight into the trafficking of GLT-1.
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Model catalysts of Pd nanoparticles and films on TiO2 (I 10) were fabricated by metal vapour deposition (MVD). Molecular beam measurements show that the particles are active for CO adsorption, with a global sticking probability of 0.25, but that they are deactivated by annealing above 600 K, an effect indicative of SMSI. The Pd nanoparticles are single crystals oriented with their (I 11) plane parallel to the surface plane of the titania. Analysis of the surface by atomic resolution STM shows that new structures have formed at the surface of the Pd nanoparticles and films after annealing above 800 K. There are only two structures, a zigzag arrangement and a much more complex "pinwheel" structure. The former has a unit cell containing 7 atoms, and the latter is a bigger unit cell containing 25 atoms. These new structures are due to an overlayer of titania that has appeared on the surface of the Pd nanoparticles after annealing, and it is proposed that the surface layer that causes the SMSI effect is a mixed alloy of Pd and Ti, with only two discrete ratios of atoms: Pd/Ti of 1: 1 (pinwheel) and 1:2 (zigzag). We propose that it is these structures that cause the SMSI effect. (c) 2005 Elsevier Inc. All rights reserved.
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One of the major factors contributing to the failure of new wheat varieties is seasonal variability in end-use quality. Consequently, it is important to produce varieties which are robust and stable over a range of environmental conditions. Recently developed sample preparation methods have allowed the application of FT-IR spectroscopic imaging methods to the analysis of wheat endosperm cell wall composition, allowing the spatial distribution of structural components to be determined without the limitations of conventional chemical analysis. The advantages of the methods, described in this paper, are that they determine the composition of endosperm cell walls in situ and with minimal modification during preparation. Two bread-making wheat cultivars, Spark and Rialto, were selected to determine the impact of environmental conditions on the cell-wall composition of the starchy endosperm of the developing and mature grain, focusing on the period of grain filling (starting at about 14 days after anthesis). Studies carried out over two successive seasons show that the structure of the arabinoxylans in the endosperm cell walls changes from a highly branched form to a less branched form. Furthermore, during development the rate of restructuring was faster when the plants were grown at higher temperature with restricted water availability from 14 days after anthesis with differences in the rate of restructuring occurring between the two cultivars.
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Over the years, the MCF7 human breast cancer cell line has provided a model system for the study of cellular and molecular mechanisms in oestrogen regulation of cell proliferation and in progression to oestrogen and antioestrogen independent growth. Global gene expression profiling has shown that oestrogen action in MCF7 cells involves the coordinated regulation of hundreds of genes across a wide range of functional groupings and that more genes are down regulated than upregulated. Adaptation to long-term oestrogen deprivation, which results in loss of oestrogen-responsive growth, involves alterations to gene patterns not only at early time points (0-4 weeks) but continuing through to later times (20-55 weeks), and even involves alterations to patterns of oestrogen-regulated gene expression. Only 48% of the genes which were regulated >= 2-fold by oestradiol in oestrogen-responsive cells retained this responsiveness after long-term oestrogen deprivation but other genes developed de novo oestrogen regulation. Long-term exposure to fulvestrant, which resulted in loss of growth inhibition by the antioestrogen, resulted in some very large fold changes in gene expression up to 10,000-fold. Comparison of gene profiles produced by environmental chemicals with oestrogenic properties showed that each ligand gave its own unique expression profile which suggests that environmental oestrogens entering the human breast may give rise to a more complex web of interference in cell function than simply mimicking oestrogen action at inappropriate times. (C) 2009 Elsevier Ltd. All rights reserved.
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BACKGROUND: The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell function in vitro, and on follicle development in vivo. METHODS: Bovine granulosa and theca cells were cultured for six days and stimulated with FSH and/or IGF, or LH in combination with PD98059 (Erk inhibitor) and/or LY294002 (Akt inhibitor) and their effect on cell number and hormone secretion (estradiol, activin-A, inhibin-A, follistatin, progesterone and androstenedione) determined. In addition, ovarian follicles were treated in vivo with PD98059 and/or LY294002 in ewes on Day 3 of the cycle and follicles were recovered 48 hours later. RESULTS: We have shown that gonadotropin- and IGF-stimulated hormone production by granulosa and theca cells is reduced by treatment with PD98059 and LY294002 in vitro. Furthermore, treatment with PD98059 and LY294002 reduced follicle growth and oestradiol production in vivo. CONCLUSION: These results demonstrate an important functional role for the Akt and Erk signalling pathways in follicle function, growth and development.
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variety of transcription factors including Wilms tumor gene (Wt-1), steroidogenic factor 1 (Sf-1), dosage-sensitive sex reversal, adrenal hypoplasia congenita on the X-chromosome, Gene 1 (Dax-1), and pre-B-cell transcription factor 1 (Pbx1) have been defined as necessary for regular adrenocortical development. However, the role of Pbx1 for adrenal growth and function in the adult organism together with the molecular relationship between Pbx1 and these other transcription factors have not been characterized. We demonstrate that Pbx haploinsufficiency (Pbx1(+/-)) in mice is accompanied by a significant lower adrenal weight in adult animals compared with wild-type controls. Accordingly, baseline proliferating cell nuclear antigen levels are lower in Pbx1(+/-) mice, and unilateral adrenalectomy results in impaired contralateral compensatory adrenal growth, indicating a lower proliferative potential in the context of Pbx1 haploinsufficiency. In accordance with the key role of IGFs in adrenocortical proliferation and development, real-time RT-PCR demonstrates significant lower expression levels of the IGF-I receptor, and up-regulation of IGF binding protein-2. Functionally, Pbx1(+/-) mice display a blunted corticosterone response after ACTH stimulation coincident with lower adrenal expression of the ACTH receptor (melanocortin 2 receptor, Mc2-r). Mechanistically, in vitro studies reveal that Pbx1 and Sf-1 synergistically stimulates Mc2-r promoter activity. Moreover, Sf-1 directly activates the Pbx1 promoter activity in vitro and in vivo. Taken together, these studies provide evidence for a role of Pbx1 in the maintenance of a functional adrenal cortex mediated by synergistic actions of Pbx1 and Sf-1 in the transcriptional regulation of the critical effector of adrenocortical differentiation, the ACTH receptor.
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This paper addresses the question of whether p-hydroxybenzoic acid, the common metabolite of parabens, possesses oestrogenic activity in human breast cancer cell lines. The alkyl esters of p-hydroxybenzoic acid (parabens) are used widely as preservatives in consumer products to which the human population is exposed and have been shown previously to possess oestrogenic activity and to be present in human breast tumour tissue, which is an oestrogen-responsive tissue. Recent work has shown p-hydroxybenzoic acid to give an oestrogenic response in the rodent uterotrophic assay. We report here that p-hydroxybenzoic acid possesses oestrogenic activity in a panel of assays in human breast cancer cell lines. p-Hydroxybenzoic acid was able to displace [H-3]oestradiol from cytosolic oestrogen receptor of MCF7 human breast cancer cells by 54% at 5 x 10(6)-fold molar excess and by 99% at 10(7)-fold molar excess. It was able to increase the expression of a stably integrated oestrogen responsive reporter gene (ERE-CAT) at a concentration of 5 x 10(-4) M in MCF7 cells after 24 h and 7 days, which could be inhibited by the anti-oestrogen ICI 182 780 (Faslodex, fulvestrant). Proliferation of two human breast cancer cell lines (MCF7, ZR-75-1) could be increased by 10(-5) M p-hydroxybenzoic acid. Following on from previous studies showing a decrease in oestrogenic activity of parabens with shortening of the linear alkyl chain length, this study has compared the oestrogenic activity of p-hydroxybenzoic acid where the alkyl grouping is no longer present with methylparaben, which has the shortest alkyl group. Intrinsic oestrogenic activity of p-hydroxybenzoic acid was similar to that of methylparaben in terms of relative binding to the oestrogen receptor but its oestrogenic activity on gene expression and cell proliferation was lower than that of methylparaben. It can be concluded that removal of the ester group from parabens does not abrogate its oestrogenic activity and that p-hydroxybenzoic acid can give oestrogenic responses in human breast cancer cells. Copyright (C) 2005 John Wiley & Sons, Ltd.