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- Vasan, Ramachandran S, et al.
(författare)
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Genetic variants associated with cardiac structure and function : a meta-analysis and replication of genome-wide association data
- 2009
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 302:2, s. 168-178
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Echocardiographic measures of left ventricular (LV) structure and function are heritable phenotypes of cardiovascular disease. OBJECTIVE: To identify common genetic variants associated with cardiac structure and function by conducting a meta-analysis of genome-wide association data in 5 population-based cohort studies (stage 1) with replication (stage 2) in 2 other community-based samples. DESIGN, SETTING, AND PARTICIPANTS: Within each of 5 community-based cohorts comprising the EchoGen consortium (stage 1; n = 12 612 individuals of European ancestry; 55% women, aged 26-95 years; examinations between 1978-2008), we estimated the association between approximately 2.5 million single-nucleotide polymorphisms (SNPs; imputed to the HapMap CEU panel) and echocardiographic traits. In stage 2, SNPs significantly associated with traits in stage 1 were tested for association in 2 other cohorts (n = 4094 people of European ancestry). Using a prespecified P value threshold of 5 x 10(-7) to indicate genome-wide significance, we performed an inverse variance-weighted fixed-effects meta-analysis of genome-wide association data from each cohort. MAIN OUTCOME MEASURES: Echocardiographic traits: LV mass, internal dimensions, wall thickness, systolic dysfunction, aortic root, and left atrial size. RESULTS: In stage 1, 16 genetic loci were associated with 5 echocardiographic traits: 1 each with LV internal dimensions and systolic dysfunction, 3 each with LV mass and wall thickness, and 8 with aortic root size. In stage 2, 5 loci replicated (6q22 locus associated with LV diastolic dimensions, explaining <1% of trait variance; 5q23, 12p12, 12q14, and 17p13 associated with aortic root size, explaining 1%-3% of trait variance). CONCLUSIONS: We identified 5 genetic loci harboring common variants that were associated with variation in LV diastolic dimensions and aortic root size, but such findings explained a very small proportion of variance. Further studies are required to replicate these findings, identify the causal variants at or near these loci, characterize their functional significance, and determine whether they are related to overt cardiovascular disease.
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- Berger, S. A., et al.
(författare)
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Water temperature and mixing depth affect timing and magnitude of events during spring succession of the plankton
- 2007
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Ingår i: Oecologia. ; 150:4, s. 643-654
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Tidskriftsartikel (refereegranskat)abstract
- In many lakes, the most conspicuous seasonal events are the phytoplankton spring bloom and the subsequent clear-water phase, a period of low-phytoplankton biomass that is frequently caused by mesozooplankton (Daphnia) grazing. In Central European lakes, the timing of the clear-water phase is linked to large-scale climatic forcing, with warmer winters being followed by an earlier onset of the clear-water phase. Mild winters may favour an early build-up of Daphnia populations, both directly through increased surface temperatures and indirectly by reducing light limitation and enhancing algal production, all being a consequence of earlier thermal stratification. We conducted a field experiment to disentangle the separate impacts of stratification depth (affecting light supply) and temperature on the magnitude and timing of successional events in the plankton. We followed the dynamics of the phytoplankton spring bloom, the clear-water phase and the spring peak in Daphnia abundance in response to our experimental manipulations. Deeper mixing delayed the timing of all spring seasonal events and reduced the magnitudes of the phytoplankton bloom and the subsequent Daphnia peak. Colder temperatures retarded the timing of the clear-water phase and the subsequent Daphnia peak, whereas the timing of the phytoplankton peak was unrelated to temperature. Most effects of mixing depth (light) and temperature manipulations were independent, effects of mixing depth being more prevalent than effects of temperature. Because mixing depth governs both the light climate and the temperature regime in the mixed surface layer, we propose that climate-driven changes in the timing and depth of water column stratification may have far-reaching consequences for plankton dynamics and should receive increased attention.
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- Hicks, Andrew A., et al.
(författare)
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Genetic determinants of circulating sphingolipid concentrations in European populations
- 2009
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Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 5:10, s. e1000672-
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Tidskriftsartikel (refereegranskat)abstract
- Sphingolipids have essential roles as structural components of cell membranes and in cell signalling, and disruption of their metabolism causes several diseases, with diverse neurological, psychiatric, and metabolic consequences. Increasingly, variants within a few of the genes that encode enzymes involved in sphingolipid metabolism are being associated with complex disease phenotypes. Direct experimental evidence supports a role of specific sphingolipid species in several common complex chronic disease processes including atherosclerotic plaque formation, myocardial infarction (MI), cardiomyopathy, pancreatic β-cell failure, insulin resistance, and type 2 diabetes mellitus. Therefore, sphingolipids represent novel and important intermediate phenotypes for genetic analysis, yet little is known about the major genetic variants that influence their circulating levels in the general population. We performed a genome-wide association study (GWAS) between 318,237 single-nucleotide polymorphisms (SNPs) and levels of circulating sphingomyelin (SM), dihydrosphingomyelin (Dih-SM), ceramide (Cer), and glucosylceramide (GluCer) single lipid species (33 traits); and 43 matched metabolite ratios measured in 4,400 subjects from five diverse European populations. Associated variants (32) in five genomic regions were identified with genome-wide significant corrected p-values ranging down to 9.08×10−66. The strongest associations were observed in or near 7 genes functionally involved in ceramide biosynthesis and trafficking: SPTLC3, LASS4, SGPP1, ATP10D, and FADS1–3. Variants in 3 loci (ATP10D, FADS3, and SPTLC3) associate with MI in a series of three German MI studies. An additional 70 variants across 23 candidate genes involved in sphingolipid-metabolizing pathways also demonstrate association (p = 10−4 or less). Circulating concentrations of several key components in sphingolipid metabolism are thus under strong genetic control, and variants in these loci can be tested for a role in the development of common cardiovascular, metabolic, neurological, and psychiatric diseases.
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- Marroni, Fabio, et al.
(författare)
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A genome-wide association scan of RR and QT interval duration in 3 European genetically isolated populations : the EUROSPAN project
- 2009
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Ingår i: Circulation: Cardiovascular Genetics. - 1942-3268. ; 2:4, s. 322-328
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We set out to identify common genetic determinants of the length of the RR and QT intervals in 2325 individuals from isolated European populations. METHODS AND RESULTS: We analyzed the heart rate at rest, measured as the RR interval, and the length of the corrected QT interval for association with 318 237 single-nucleotide polymorphisms. The RR interval was associated with common variants within GPR133, a G-protein-coupled receptor (rs885389, P=3.9 x 10(-8)). The QT interval was associated with the earlier reported NOS1AP gene (rs2880058, P=2.00 x 10(-10)) and with a region on chromosome 13 (rs2478333, P=4.34 x 10(-8)), which is 100 kb from the closest known transcript LOC730174 and has previously not been associated with the length of the QT interval. CONCLUSIONS: Our results suggested an association between the RR interval and GPR133 and confirmed an association between the QT interval and NOS1AP.
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- Porkka, Kimmo, et al.
(författare)
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Dasatinib crosses the blood-brain barrier and is an efficient therapy for central nervous system Philadelphia chromosome-positive leukemia
- 2008
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 112:4, s. 1005-12
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Tidskriftsartikel (refereegranskat)abstract
- Although imatinib, a BCR-ABL tyrosine kinase inhibitor, is used to treat acute Philadelphia chromosome-positive (Ph(+)) leukemia, it does not prevent central nervous system (CNS) relapses resulting from poor drug penetration through the blood-brain barrier. Imatinib and dasa-tinib (a dual-specific SRC/BCR-ABL kinase inhibitor) were compared in a preclinical mouse model of intracranial Ph(+) leukemia. Clinical dasatinib treatment in patients with CNS Ph(+) leukemia was assessed. In preclinical studies, dasatinib increased survival, whereas imatinib failed to inhibit intracranial tumor growth. Stabilization and regression of CNS disease were achieved with continued dasa-tinib administration. The drug also demonstrated substantial activity in 11 adult and pediatric patients with CNS Ph(+) leukemia. Eleven evaluable patients had clinically significant, long-lasting responses, which were complete in 7 patients. In 3 additional patients, isolated CNS relapse occurred during dasatinib therapy; and in 2 of them, it was caused by expansion of a BCR-ABL-mutated dasatinib-resistant clone, implying selection pressure exerted by the compound in the CNS. Dasatinib has promising therapeutic potential in managing intracranial leukemic disease and substantial clinical activity in patients who experience CNS relapse while on imatinib therapy. This study is registered at ClinicalTrials.gov as CA180006 (#NCT00108719) and CA180015 (#NCT00110097).
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