178 research outputs found

    Treating breast cancer through novel inhibitors of the phosphatidylinositol 3'-kinase pathway

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    Recent studies indicate that constitutive signaling through the phosphatidylinositol 3'-kinase (PI3K) pathway is a cause of treatment resistance in breast cancer patients. This implies that patients with tumors that exhibit aberrant PI3K signaling may benefit from targeted pathway inhibitors. The first agents to make it to the clinic are the rapamycin analogs. These compounds inhibit the downstream PI3K effector mTOR (mammalian target of rapamycin). A study presented in this issue of Breast Cancer Research suggests that recently developed inhibitors of phosphoinositide-dependent protein kinase 1, a more proximal target of the PI3K pathway, may provide an alternative route to effective PI3K pathway inhibition for breast cancer treatment

    Mapping the Anthocyaninless (anl) Locus in Rapid-Cycling Brassica rapa (RBr) to Linkage Group R9

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    <p>Abstract</p> <p>Background</p> <p>Anthocyanins are flavonoid pigments that are responsible for purple coloration in the stems and leaves of a variety of plant species. <it>Anthocyaninless </it>(<it>anl</it>) mutants of <it>Brassica rapa </it>fail to produce anthocyanin pigments. In rapid-cycling <it>Brassica rapa</it>, also known as Wisconsin Fast Plants, the anthocyaninless trait, also called non-purple stem, is widely used as a model recessive trait for teaching genetics. Although anthocyanin genes have been mapped in other plants such as <it>Arabidopsis thaliana</it>, the <it>anl </it>locus has not been mapped in any <it>Brassica </it>species.</p> <p>Results</p> <p>We tested primer pairs known to amplify microsatellites in <it>Brassicas </it>and identified 37 that amplified a product in rapid-cycling <it>Brassica rapa</it>. We then developed three-generation pedigrees to assess linkage between the microsatellite markers and <it>anl</it>. 22 of the markers that we tested were polymorphic in our crosses. Based on 177 F<sub>2 </sub>offspring, we identified three markers linked to <it>anl </it>with LOD scores ≥ 5.0, forming a linkage group spanning 46.9 cM. Because one of these markers has been assigned to a known <it>B. rapa </it>linkage group, we can now assign the <it>anl </it>locus to <it>B. rapa </it>linkage group R9.</p> <p>Conclusion</p> <p>This study is the first to identify the chromosomal location of an anthocyanin pigment gene among the <it>Brassicas</it>. It also connects a classical mutant frequently used in genetics education with molecular markers and a known chromosomal location.</p

    The Main Belt Comets and ice in the Solar System

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    We review the evidence for buried ice in the asteroid belt; specifically the questions around the so-called Main Belt Comets (MBCs). We summarise the evidence for water throughout the Solar System, and describe the various methods for detecting it, including remote sensing from ultraviolet to radio wavelengths. We review progress in the first decade of study of MBCs, including observations, modelling of ice survival, and discussion on their origins. We then look at which methods will likely be most effective for further progress, including the key challenge of direct detection of (escaping) water in these bodies

    GOBO: Gene Expression-Based Outcome for Breast Cancer Online

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    Microarray-based gene expression analysis holds promise of improving prognostication and treatment decisions for breast cancer patients. However, the heterogeneity of breast cancer emphasizes the need for validation of prognostic gene signatures in larger sample sets stratified into relevant subgroups. Here, we describe a multifunctional user-friendly online tool, GOBO (http://co.bmc.lu.se/gobo), allowing a range of different analyses to be performed in an 1881-sample breast tumor data set, and a 51-sample breast cancer cell line set, both generated on Affymetrix U133A microarrays. GOBO supports a wide range of applications including: 1) rapid assessment of gene expression levels in subgroups of breast tumors and cell lines, 2) identification of co-expressed genes for creation of potential metagenes, 3) association with outcome for gene expression levels of single genes, sets of genes, or gene signatures in multiple subgroups of the 1881-sample breast cancer data set. The design and implementation of GOBO facilitate easy incorporation of additional query functions and applications, as well as additional data sets irrespective of tumor type and array platform

    Functional genomic analysis of drug sensitivity pathways to guide adjuvant strategies in breast cancer

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    The widespread introduction of high throughput RNA interference screening technology has revealed tumour drug sensitivity pathways to common cytotoxics such as paclitaxel, doxorubicin and 5-fluorouracil, targeted agents such as trastuzumab and inhibitors of AKT and Poly(ADP-ribose) polymerase (PARP) as well as endocrine therapies such as tamoxifen. Given the limited power of microarray signatures to predict therapeutic response in associative studies of small clinical trial cohorts, the use of functional genomic data combined with expression or sequence analysis of genes and microRNAs implicated in drug response in human tumours may provide a more robust method to guide adjuvant treatment strategies in breast cancer that are transferable across different expression platforms and patient cohorts

    Assessment of nerve involvement in the lumbar spine: agreement between magnetic resonance imaging, physical examination and pain drawing findings

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    <p>Abstract</p> <p>Background</p> <p>Detection of nerve involvement originating in the spine is a primary concern in the assessment of spine symptoms. Magnetic resonance imaging (MRI) has become the diagnostic method of choice for this detection. However, the agreement between MRI and other diagnostic methods for detecting nerve involvement has not been fully evaluated. The aim of this diagnostic study was to evaluate the agreement between nerve involvement visible in MRI and findings of nerve involvement detected in a structured physical examination and a simplified pain drawing.</p> <p>Methods</p> <p>Sixty-one consecutive patients referred for MRI of the lumbar spine were - without knowledge of MRI findings - assessed for nerve involvement with a simplified pain drawing and a structured physical examination. Agreement between findings was calculated as overall agreement, the p value for McNemar's exact test, specificity, sensitivity, and positive and negative predictive values.</p> <p>Results</p> <p>MRI-visible nerve involvement was significantly less common than, and showed weak agreement with, physical examination and pain drawing findings of nerve involvement in corresponding body segments. In spine segment L4-5, where most findings of nerve involvement were detected, the mean sensitivity of MRI-visible nerve involvement to a positive neurological test in the physical examination ranged from 16-37%. The mean specificity of MRI-visible nerve involvement in the same segment ranged from 61-77%. Positive and negative predictive values of MRI-visible nerve involvement in segment L4-5 ranged from 22-78% and 28-56% respectively.</p> <p>Conclusion</p> <p>In patients with long-standing nerve root symptoms referred for lumbar MRI, MRI-visible nerve involvement significantly underestimates the presence of nerve involvement detected by a physical examination and a pain drawing. A structured physical examination and a simplified pain drawing may reveal that many patients with "MRI-invisible" lumbar symptoms need treatment aimed at nerve involvement. Factors other than present MRI-visible nerve involvement may be responsible for findings of nerve involvement in the physical examination and the pain drawing.</p

    Mechanisms of initiation and reversal of drug-seeking behavior induced by prenatal exposure to glucocorticoids

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    We would like to thank the members of the Neuroscience Research Domain at ICVS for all the helpful discussions and suggestions. We are especially thankful to the animal facility caretakers, and to Drs Sara Silva, António Melo and Ana Paula Silva and Dieter Fischer for their helpStress and exposure to glucocorticoids (GC) during early life render individuals vulnerable to brain disorders by inducing structural and chemical alterations in specific neural substrates. Here we show that adult rats that had been exposed to in utero GCs (iuGC) display increased preference for opiates and ethanol, and are more responsive to the psychostimulatory actions of morphine. These animals presented prominent changes in the nucleus accumbens (NAcc), a key component of the mesolimbic reward circuitry; specifically, cell numbers and dopamine (DA) levels were significantly reduced, whereas DA receptor 2 (Drd2) mRNA expression levels were markedly upregulated in the NAcc. Interestingly, repeated morphine exposure significantly downregulated Drd2 expression in iuGC-exposed animals, in parallel with increased DNA methylation of the Drd2 gene. Administration of a therapeutic dose of L-dopa reverted the hypodopaminergic state in the NAcc of iuGC animals, normalized Drd2 expression and prevented morphine-induced hypermethylation of the Drd2 promoter. In addition, L-dopa treatment promoted dendritic and synaptic plasticity in the NAcc and, importantly, reversed drug-seeking behavior. These results reveal a new mechanism through which drug-seeking behaviors may emerge and suggest that a brief and simple pharmacological intervention can restrain these behaviors in vulnerable individuals.This work was supported by the Institute for the Study of Affective Neuroscience (ISAN). AJR, BC and MC were supported by Fundação para a Ciência e Tecnologia (FCT) fellowship

    A High Density Consensus Map of Rye (Secale cereale L.) Based on DArT Markers

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    L.) is an economically important crop, exhibiting unique features such as outstanding resistance to biotic and abiotic stresses and high nutrient use efficiency. This species presents a challenge to geneticists and breeders due to its large genome containing a high proportion of repetitive sequences, self incompatibility, severe inbreeding depression and tissue culture recalcitrance. The genomic resources currently available for rye are underdeveloped in comparison with other crops of similar economic importance. The aim of this study was to create a highly saturated, multilocus linkage map of rye via consensus mapping, based on Diversity Arrays Technology (DArT) markers.Recombinant inbred lines (RILs) from 5 populations (564 in total) were genotyped using DArT markers and subjected to linkage analysis using Join Map 4.0 and Multipoint Consensus 2.2 software. A consensus map was constructed using a total of 9703 segregating markers. The average chromosome map length ranged from 199.9 cM (2R) to 251.4 cM (4R) and the average map density was 1.1 cM. The integrated map comprised 4048 loci with the number of markers per chromosome ranging from 454 for 7R to 805 for 4R. In comparison with previously published studies on rye, this represents an eight-fold increase in the number of loci placed on a consensus map and a more than two-fold increase in the number of genetically mapped DArT markers.Through the careful choice of marker type, mapping populations and the use of software packages implementing powerful algorithms for map order optimization, we produced a valuable resource for rye and triticale genomics and breeding, which provides an excellent starting point for more in-depth studies on rye genome organization
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