3,156 research outputs found

    Differential Retinoic Acid Signaling in Tumors of Long- and Short-term Glioblastoma Survivors

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    Although the prognosis of most glioblastoma patients is poor, 3%-5% patients show long-term survival of 36 months or longer after diagnosis. To study the differences in activation of biochemical pathways, we performed mRNA and protein expression analyses of primary glioblastoma tissues from 11 long-term survivors (LTS; overall survival ≥ 36 months) and 12 short-term survivors (STS; overall survival ≤ 6 months). The mRNA expression ratio of the retinoic acid transporters fatty acid-binding protein 5 (FABP5) and cellular retinoic acid-binding protein 2 (CRABP2), which regulate the differential delivery of retinoic acid to either antioncogenic retinoic acid receptors or prooncogenic nuclear receptor peroxisome proliferator-activated receptor delta, was statistically significantly higher in the tumor tissues of STS than those of LTS (median ratio in STS tumors = 3.64, 10th-90th percentile = 1.43-4.54 vs median ratio in LTS tumors = 1.42, 10th-90th percentile = −0.98 to 2.59; P < .001). High FABP5 protein expression in STS tumors was associated with highly proliferating tumor cells and activation of 3-phosphoinositide-dependent protein kinase-1 and v-akt murine thymoma viral oncogene homolog. The data suggest that retinoic acid signaling activates different targets in glioblastomas from LTS and STS. All statistical tests were two-side

    The STR polymorphism (AAAAT)n within the intron 1 of the tumor protein 53 (TP53) locus in 17 populations of different ethnic groups of Africa, America, Asia and Europe

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    artículo arbitrado -- Universidad de Costa Rica, Instituto de investigaciones en Salud. 2004The SIR (A.AAAT). within intron 1 of the TP53 Locus was screened in 17 populations from 3 main ethnic groups: Europeans, Asiatics, and Africans. and from the hybrid population of Costa Rica (1968 samples). Three alleles, 126)7 (bp/copies of the repeat), 13118 and 136/9 were the most prevalent in all populations. Other alleles rarely reached frequencies of 10% or higher. Observed heterozygosities ranged between 0.351 and 0.829. Patterns of diversity fit well with both the geographic origin of the samples and the history of the populations screened. A statistical test suggests that single-step mutational events have been the main mechanism producing new alleles at this locus. Fixation indexes (R57) for this marker showed an effect of population subdivision on divergence only within the Asiatic group; they were insensitive at the level of major ethnic groups as well as within Africans and within EuropeansSe estudio el polimorfismo del microsatelite (AAAAI), del intron 1 del gene TP53 en 17 poblaciones de 3 grupos etnicos: europeos, asiaticos, y africanos subsaharianos, asi coma de la poblacion hibrida de Costa Rica (en total 1968 muestras). Tres aides, 12617 (pares de bases/ copias de la repetición), 131/8 y 136/9 fueron los mas frecuentes en todas las poblaciones, aunque se observaron otros alelos usualmente a frecuencias menores al 10%. Las heterocigosis observadas variaron de 0.351 a 0.829. La distribucion de la universidad parece concordar con el origen geográfico de las muestras y con la historia de las poblaciones estudiadas. Una prueba estadística indica que el evento mutacional que mas alelos nuevos produce en ese marcador es el de un solo paso (expansión o contracción de una cola copia de la repeticion). El indice de fijacion R„ mostro los efectos de la subdivision de poblaciones solo dentro del grupo de los asiaticos y mostro falta de sensibilidad cuando los grupos comparados eran de nivetes superiores de clasificacion (europeos, asiaticos, y africanos) o cuando la comparación se hizo entre los grupos mas antiguos (africanos y europeos).Universidad de costa Rica, Instituto de investigaciones en Salud.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

    A dual-tag microarray platform for high-performance nucleic acid and protein analyses

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    DNA microarrays serve to monitor a wide range of molecular events, but emerging applications like measurements of weakly expressed genes or of proteins and their interaction patterns will require enhanced performance to improve specificity of detection and dynamic range. To further extend the utility of DNA microarray-based approaches we present a high-performance tag microarray procedure that enables probe-based analysis of as little as 100 target cDNA molecules, and with a linear dynamic range close to 105. Furthermore, the protocol radically decreases the risk of cross-hybridization on microarrays compared to current approaches, and it also allows for quantification by single-molecule analysis and real-time on-chip monitoring of rolling-circle amplification. We provide proof of concept for microarray-based measurement of both mRNA molecules and of proteins, converted to tag DNA sequences by padlock and proximity probe ligation, respectively

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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