315 research outputs found
The determinants of vulnerability to currency crises: country-specific factors versus regional factors
We investigate the determinants of exchange market pressures (EMP) for some new EU member states at both the national and regional levels, where macroeconomic and financial variables are considered as potential sources. The regional common factors are extracted from these variables by using dynamic factor analysis. The linear empirical analysis, in general, highlights the importance of country-specific factors to defend themselves against vulnerability in their external sectors. Yet, given a significant impact of the common component in credit on EMP, a contagion effect is apparent through the conduit of credit market integration across these countries under investigation
The future of metabolomics in ELIXIR.
Metabolomics, the youngest of the major omics technologies, is supported by an active community of researchers and infrastructure developers across Europe. To coordinate and focus efforts around infrastructure building for metabolomics within Europe, a workshop on the "Future of metabolomics in ELIXIR" was organised at Frankfurt Airport in Germany. This one-day strategic workshop involved representatives of ELIXIR Nodes, members of the PhenoMeNal consortium developing an e-infrastructure that supports workflow-based metabolomics analysis pipelines, and experts from the international metabolomics community. The workshop established metabolite identification as the critical area, where a maximal impact of computational metabolomics and data management on other fields could be achieved. In particular, the existing four ELIXIR Use Cases, where the metabolomics community - both industry and academia - would benefit most, and which could be exhaustively mapped onto the current five ELIXIR Platforms were discussed. This opinion article is a call for support for a new ELIXIR metabolomics Use Case, which aligns with and complements the existing and planned ELIXIR Platforms and Use Cases
Gene expression profiles derived from fine needle aspiration correlate with response to systemic chemotherapy in breast cancer
BACKGROUND: Drug resistance in breast cancer is a major obstacle to successful chemotherapy. In this study we used cDNA microarray technology to examine gene expression profiles obtained from fine needle aspiration (FNA) of primary breast tumors before and after systemic chemotherapy. Our goal was to determine the feasibility of obtaining representative expression array profiles from limited amounts of tissue and to identify those expression profiles that correlate with treatment response. METHODS: Repeat presurgical FNA samples were taken from six patients who were to undergo primary surgical treatment. Additionally, a group of 10 patients who were to receive neoadjuvant chemotherapy underwent two FNAs before chemotherapy (adriamycin 60 mg/m(2) and cyclophosphamide 600 mg/m(2)) followed by another FNA on day 21 after the first cycle. Total RNA was amplified with T7 Eberwine's procedure and labeled cDNA was hybridized onto a 7600-feature glass cDNA microarray. RESULTS: We identified candidate gene expression profiles that might distinguish tumors with complete response to chemotherapy from tumors that do not respond, and found that the number of genes that change after one cycle of chemotherapy was 10 times greater in the responding group than in the non-responding group. CONCLUSION: This study supports the suitability of FNA-derived cDNA microarray expression profiling of breast cancers as a comprehensive genomic approach for studying the mechanisms of drug resistance. Our findings also demonstrate the potential of monitoring post-chemotherapy changes in expression profiles as a measure of pharmacodynamic effect and suggests that these approaches might yield useful results when validated by larger studies
Economic Crisis and Investor Behaviour
This study investigates the effects of crises on domestic and foreign investors’ behaviours by utilizing a nonlinear approach. Considering the nonlinearity inherent in many financial variables, this study proposes an appropriate econometric modelling for analysing the investors’ behaviour, particularly during turbulent times. Specifically, STAR-STGARCH family models and generalized impulse response function analysis (GIRF) are employed to understand the different reactions of foreign and domestic investors at the Malaysian Stock Exchange market during the 1997 Asian crisis. The results of the model and the GIRF analysis have shown that foreign investors exhibited a herding behavior during the crisis and responded the shock more quickly than the domestic investors. When the same analysis is applied to understand the effects of the 2008 Subprime Mortgage Crisis in the Malaysian market, the behaviors of foreign and domestic investors are found to be very similar
Q&A: ChIP-seq technologies and the study of gene regulation
10.1186/1741-7007-8-56BMC Biology85
ESR1 and EGF genetic variation in relation to breast cancer risk and survival
The main purposes of this thesis were to analyse common genetic variation in candidate
genes and candidate pathways in relation to breast cancer risk, prognosticators and
survival, to develop statistical methods for genetic association analysis for evaluating
the joint importance of genes, and to investigate the potential impact of adding genetic
information to clinical risk factors for projecting individualised risk of developing
breast cancer over specific time periods.
In Paper I we studied genetic variation in the estrogen receptor α and epidermal growth
factor genes in relation to breast cancer risk and survival. We located a region in the
estrogen receptor α gene which showed a moderate signal for association with breast
cancer risk but were unable to link common variation in the epidermal growth factor
gene with breast cancer aetiology or prognosis.
In Paper II we investigated whether suspected breast cancer risk SNPs within genes
involved in androgen-to-estrogen conversion are associated with breast cancer
prognosticators grade, lymph node status and tumour size. The strongest association
was observed for a marker within the CYP19A1 gene with histological grade. We also
found evidence that a second marker from the same gene is associated with histological
grade and tumour size.
In Paper III we developed a novel test of association which incorporates multivariate
measures of categorical and continuous heterogeneity. In this work we described both a
single-SNP and a global multi-SNP test and used simulated data to demonstrate the
power of the tests when genetic effects differ across disease subtypes.
In Paper IV we assessed the extent to which recently associated genetic risk variants
improve breast cancer risk-assessment models. We investigated empirically the
performance of eighteen breast cancer risk SNPs together with mammographic density
and clinical risk factors in predicting absolute risk of breast cancer. We also examined
the usefulness of various prediction models considered at a population level for a
variety of individualised breast cancer screening approaches.
The goal of a genetic association study is to establish statistical associations between
genetic variants and disease states. Each variant linked to a disease can lead the way to
a better understanding of the underlying biological mechanisms that govern the
development of a disease. Increased knowledge of molecular variation provides the
opportunity to stratify populations according to genetic makeup, which in turn has the
potential to lead to improved disease prevention programs and improved patient care
Global Profiling of DNA Replication Timing and Efficiency Reveals that Efficient Replication/Firing Occurs Late during S-Phase in S. pombe
10.1371/journal.pone.0000722PLoS ONE2
Hormone-replacement therapy influences gene expression profiles and is associated with breast-cancer prognosis: a cohort study
BACKGROUND: Postmenopausal hormone-replacement therapy (HRT) increases breast-cancer risk. The influence of HRT on the biology of the primary tumor, however, is not well understood. METHODS: We obtained breast-cancer gene expression profiles using Affymetrix human genome U133A arrays. We examined the relationship between HRT-regulated gene profiles, tumor characteristics, and recurrence-free survival in 72 postmenopausal women. RESULTS: HRT use in patients with estrogen receptor (ER) protein positive tumors (n = 72) was associated with an altered regulation of 276 genes. Expression profiles based on these genes clustered ER-positive tumors into two molecular subclasses, one of which was associated with HRT use and had significantly better recurrence free survival despite lower ER levels. A comparison with external data suggested that gene regulation in tumors associated with HRT was negatively correlated with gene regulation induced by short-term estrogen exposure, but positively correlated with the effect of tamoxifen. CONCLUSION: Our findings suggest that post-menopausal HRT use is associated with a distinct gene expression profile related to better recurrence-free survival and lower ER protein levels. Tentatively, HRT-associated gene expression in tumors resembles the effect of tamoxifen exposure on MCF-7 cells
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