104 research outputs found

    A comparison of A-level performance in economics and business studies: how much more difficult is economics?

    Get PDF
    This paper uses ALIS data to compare academic performance in two subjects often viewed as relatively close substitutes for one another at A-level. The important role of GCSE achievement is confirmed for both subjects. There is evidence of strong gender effects and variation in outcomes across Examination Boards. A counterfactual exercise suggests that if the sample of Business Studies candidates had studied Economics nearly 40% of those who obtained a grade C or better in the former subject would not have done so in the latter. The opposite exercise uggests that 12% more Economics candidates would have achieved a grade C or better if they had taken Business Studies. In order to render a Business Studies A-level grade comparable to an Economics one in terms of relative difficulty, we estimate that a downward adjustment of 1.5 UCAS points should be applied to the former subject. This adjustment is lower than that suggested by correction factors based on conventional subject pair analysis for these two subjects

    Modeling Therapy Resistance in <i>BRCA1/2</i>-Mutant Cancers.

    Get PDF
    Although PARP inhibitors target BRCA1- or BRCA2-mutant tumor cells, drug resistance is a problem. PARP inhibitor resistance is sometimes associated with the presence of secondary or "revertant" mutations in BRCA1 or BRCA2 Whether secondary mutant tumor cells are selected for in a Darwinian fashion by treatment is unclear. Furthermore, how PARP inhibitor resistance might be therapeutically targeted is also poorly understood. Using CRISPR mutagenesis, we generated isogenic tumor cell models with secondary BRCA1 or BRCA2 mutations. Using these in heterogeneous in vitro culture or in vivo xenograft experiments in which the clonal composition of tumor cell populations in response to therapy was monitored, we established that PARP inhibitor or platinum salt exposure selects for secondary mutant clones in a Darwinian fashion, with the periodicity of PARP inhibitor administration and the pretreatment frequency of secondary mutant tumor cells influencing the eventual clonal composition of the tumor cell population. In xenograft studies, the presence of secondary mutant cells in tumors impaired the therapeutic effect of a clinical PARP inhibitor. However, we found that both PARP inhibitor-sensitive and PARP inhibitor-resistant BRCA2 mutant tumor cells were sensitive to AZD-1775, a WEE1 kinase inhibitor. In mice carrying heterogeneous tumors, AZD-1775 delivered a greater therapeutic benefit than olaparib treatment. This suggests that despite the restoration of some BRCA1 or BRCA2 gene function in "revertant" tumor cells, vulnerabilities still exist that could be therapeutically exploited. Mol Cancer Ther; 16(9); 2022-34. Ā©2017 AACR

    Gene expression profile of circulating tumor cells in breast cancer by RT-qPCR

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Circulating tumor cells (CTCs) have been associated with prognosis especially in breast cancer and have been proposed as a liquid biopsy for repeated follow up examinations. Molecular characterization of CTCs is difficult to address since they are very rare and the amount of available sample is very limited.</p> <p>Methods</p> <p>We quantified by RT-qPCR <it>CK-19, MAGE-A3, HER-2, TWIST1, hTERT Ī±+Ī²+</it>, and <it>mammaglobin </it>gene transcripts in immunomagnetically positively selected CTCs from 92 breast cancer patients, and 28 healthy individuals. We also compared our results with the CellSearch system in 33 of these patients with early breast cancer.</p> <p>Results</p> <p>RT-qPCR is highly sensitive and specific and can detect the expression of each individual gene at the one cell level. None of the genes tested was detected in the group of healthy donors. In 66 operable breast cancer patients, <it>CK-19 </it>was detected in 42.4%, <it>HER-2 </it>in 13.6%, <it>MAGE-A3 </it>in 21.2%, <it>hMAM </it>in 13.6%, <it>TWIST-1 </it>in 42.4%, and <it>hTERT Ī±+Ī²+ </it>in 10.2%. In 26 patients with verified metastasis, <it>CK-19 </it>was detected in 53.8%, <it>HER-2 </it>in 19.2%, <it>MAGE-A3 </it>in 15.4%, <it>hMAM </it>in 30.8%, <it>TWIST-1 </it>in 38.5% and <it>hTERT </it>Ī±<sup>+</sup>Ī²<sup>+</sup>in 19.2%. Our preliminary data on the comparison between RT-qPCR and CellSearch in 33 early breast cancer patients showed that RT-qPCR gives more positive results in respect to CellSearch.</p> <p>Conclusions</p> <p>Molecular characterization of CTCs has revealed a remarkable heterogeneity of gene expression between breast cancer patients. In a small percentage of patients, CTCs were positive for all six genes tested, while in some patients only one of these genes was expressed. The clinical significance of these findings in early breast cancer remains to be elucidated when the clinical outcome for these patients is known.</p

    Evidence for a Novel Marine Harmful Algal Bloom: Cyanotoxin (Microcystin) Transfer from Land to Sea Otters

    Get PDF
    ā€œSuper-bloomsā€ of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine ā€œharmful algal bloomā€ in the Pacific coastal environment; that of hepatotoxic shellfish poisoning (HSP), suggesting that animals and humans are at risk from microcystin poisoning when consuming shellfish harvested at the land-sea interface

    Large-Scale Profiling of Kinase Dependencies in Cancer Cell Lines

    Get PDF
    One approach to identifying cancer-specific vulnerabilities and therapeutic targets is to profile genetic dependencies in cancer cell lines. Here, we describe data from a series of siRNA screens that identify the kinase genetic dependencies in 117 cancer cell lines from ten cancer types. By integrating the siRNA screen data with molecular profiling data, including exome sequencing data, we show how vulnerabilities/genetic dependencies that are associated with mutations in specific cancer driver genes can be identified. By integrating additional data sets into this analysis, including protein-protein interaction data, we also demonstrate that the genetic dependencies associated with many cancer driver genes form dense connections on functional interaction networks. We demonstrate the utility of this resource by using it to predict the drug sensitivity of genetically or histologically defined subsets of tumor cell lines, including an increased sensitivity of osteosarcoma cell lines to FGFR inhibitors and SMAD4 mutant tumor cells to mitotic inhibitors

    The relation between neuromechanical parameters and Ashworth score in stroke patients

    Get PDF
    Quantifying increased joint resistance into its contributing factors i.e. stiffness and viscosity ("hypertonia") and stretch reflexes ("hyperreflexia") is important in stroke rehabilitation. Existing clinical tests, such as the Ashworth Score, do not permit discrimination between underlying tissue and reflexive (neural) properties. We propose an instrumented identification paradigm for early and tailor made interventions.BioMechanical EngineeringMechanical, Maritime and Materials Engineerin

    The Intensity of IUGR-Induced Transcriptome Deregulations Is Inversely Correlated with the Onset of Organ Function in a Rat Model

    Get PDF
    A low-protein diet applied during pregnancy in the rat results in intrauterine growth restricted (IUGR) fetuses. In humans, IUGR is associated with increased perinatal morbidity, higher incidence of neuro-developmental defects and increased risk of adult metabolic anomalies, such as diabetes and cardiovascular disease. Development and function of many organs are affected by environmental conditions such as those inducing fetal and early postnatal growth restriction. This phenomenon, termed ā€œfetal programmingā€ has been studied unconnectedly in some organs, but very few studies (if any) have investigated at the same time several organs, on a more comparative basis. However, it is quite probable that IUGR affects differentially most organ systems, with possible persistent changes in gene expression. In this study we address transcriptional alterations induced by IUGR in a multi-organ perspective, by systematic analysis of 20-days rat fetuses. We show that (1) expressional alterations are apparently stronger in organs functioning late in foetal or postnatal life than in organs that are functioning early (2) hierarchical classification of the deregulations put together kidney and placenta in one cluster, liver, lungs and heart in another; (3) the epigenetic machinery is set up especially in the placenta, while its alterations are rather mild in other organs; (4) the genes appear deregulated in chromosome clusters; (5) the altered expression cascades varies from organ to organ, with noticeably a very significant modification of the complement and coagulation cascades in the kidney; (6) we found a significant increase in TF binding site for HNF4 proteins specifically for liver genes that are down-regulated in IUGR, suggesting that this decrease is achieved through the action of HNF transcription factors, that are themselves transcriptionnally induced in the liver by IUGR (x 1.84 fold). Altogether, our study suggests that a combination of tissue-specific mechanisms contributes to bring about tissue-driven modifications of gene cascades. The question of these cascades being activated to adapt the organ to harsh environmental condition, or as an endpoint consequence is still raised

    Targeting poly(ADP-ribose) polymerase activity for cancer therapy

    Get PDF
    Poly(ADP-ribosyl)ation is a ubiquitous protein modification found in mammalian cells that modulates many cellular responses, including DNA repair. The poly(ADP-ribose) polymerase (PARP) family catalyze the formation and addition onto proteins of negatively charged ADP-ribose polymers synthesized from NAD+. The absence of PARP-1 and PARP-2, both of which are activated by DNA damage, results in hypersensitivity to ionizing radiation and alkylating agents. PARP inhibitors that compete with NAD+ at the enzymeā€™s activity site are effective chemo- and radiopotentiation agents and, in BRCA-deficient tumors, can be used as single-agent therapies acting through the principle of synthetic lethality. Through extensive drug-development programs, third-generation inhibitors have now entered clinical trials and are showing great promise. However, both PARP-1 and PARP-2 are not only involved in DNA repair but also in transcription regulation, chromatin modification, and cellular homeostasis. The impact on these processes of PARP inhibition on long-term therapeutic responses needs to be investigated
    • ā€¦
    corecore