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- Danielsson, Christian, et al.
(författare)
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Exploration of human, rat, and rabbit embryonic cardiomyocytes suggests K-channel block as a common teratogenic mechanism
- 2013
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Ingår i: Cardiovascular Research. - : Oxford University Press (OUP): Policy B. - 0008-6363 .- 1755-3245. ; 97:1, s. 23-32
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Tidskriftsartikel (refereegranskat)abstract
- Several drugs blocking the rapidly activating potassium (K-r) channel cause malformations (including cardiac defects) and embryonic death in animal teratology studies. In humans, these drugs have an established risk for acquired long-QT syndrome and arrhythmia. Recently, associations between cardiac defects and spontaneous abortions have been reported for drugs widely used in pregnancy (e.g. antidepressants), with long-QT syndrome risk. To investigate whether a common embryonic adverse-effect mechanism exists in the human, rat, and rabbit embryos, we made a comparative study of embryonic cardiomyocytes from all three species. less thanbrgreater than less thanbrgreater thanPatch-clamp and quantitative-mRNA measurements of K-r and slowly activating K (K-s) channels were performed on human, rat, and rabbit primary cardiomyocytes and cardiac samples from different embryo-foetal stages. The K-r channel was present when the heart started to beat in all species, but was, in contrast to human and rabbit, lost in rats in late organogenesis. The specific K-r-channel blocker E-4031 prolonged the action potential in a species- and development-dependent fashion, consistent with the observed K-r-channel expression pattern and reported sensitive periods of developmental toxicity. E-4031 also increased the QT interval and induced 2:1 atrio-ventricular block in multi-electrode array electrographic recordings of rat embryos. The K-s channel was expressed in human and rat throughout the embryo-foetal period but not in rabbit. less thanbrgreater than less thanbrgreater thanThis first comparison of mRNA expression, potassium currents, and action-potential characteristics, with and without a specific K-r-channel blocker in human, rat, and rabbit embryos provides evidence of K-r-channel inhibition as a common mechanism for embryonic malformations and death.
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- Svensson, Marcus, et al.
(författare)
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Heat stabilization of the tissue proteome : a new technology for improved proteomics
- 2009
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 8:2, s. 974-981
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Tidskriftsartikel (refereegranskat)abstract
- After tissue or body fluid sampling, proteases and other protein-modifying enzymes can rapidly change composition of the proteome. As a direct consequence, analytical results will reflect a mix of in vivo proteome and ex vivo degradation products. Vital information about the presampling state may be destroyed or distorted, leading to variation between samples and incorrect conclusions. Sample stabilization and standardization of sample handling can reduce or eliminate this problem. Here, a novel tissue stabilization system which utilizes a combination of heat and pressure under vacuum was used to stop degradation in mouse brain tissue immediately after sampling. It was found by biochemical assays that enzymatic activity was reduced to background levels in stabilized samples. Western blot analysis confirmed that post-translational phosphorylations of analyzed proteins were stable and conserved for up to 2 h at room temperature and that peptide extracts were devoid of abundant protein degradation fragments. The combination of reduced complexity and proteolytic inactivation enabled mass spectrometric identification of several neuropeptides and endogenous peptides including modified species at higher levels compared to nonstabilized samples. The tissue stabilizing system ensures reproducible and rapid inactivation of enzymes. Therefore, the system provides a powerful improvement to proteomics by greatly reducing the complexity and dynamic range of the proteome in tissue samples and enables enhanced possibilities for discovery and analysis of clinically relevant protein/peptide biomarkers.
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- Söderberg, Stefan, et al.
(författare)
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MEASURES OF WAIST AND HIP MODIFY SEX-SPECIFIC ASSOCIATIONS BETWEEN BODY MASS INDEX AND PREVALENCE OF CORONARY ARTERY CALCIFICATION IN OPPOSITE DIRECTIONS
- 2019
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Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 13-13
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Obesity is associated with increased risk of cardiovascular disease. However, there is still a debate whether accumulation of fat in certain depots modifies this risk. Using data from the CArdioPulmonary bioImage Study (SCAPIS), we investigated if anthropometric measurements of obesity (waist and hip) modifies the risk of coronary artery calcification. Methods: In the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on coronary artery calcification score (CACS) and anthropometry were recorded and traditional cardiovascular risk factors were measured. Body mass index (BMI) was categorized as; <25, 25-30, 30-35 and >35 kg/m2 , quartiles of waist and hip circumferences were constructed within each BMI category and compared using the lowest quartile as reference. Results were adjusted for site, age, smoking and diabetes status. Results: Obesity (BMI >30 kg/m2 ) was found in 21.9% of men and in 20.5% of women. In both sexes the odds ratio (OR) for CACS >0 increased with increasing BMI categories: comparing <25 and >35 kg/m2 , OR = 2.1 (95% CI: 1.6-2.7) for men and OR = 1.4 (1.2-1.8) for women. In addition, increasing quartiles of waist significantly increased the prevalence of CACS >0 for men [p = 0.05; OR = 1.2 (1.0-1.4) for highest quartile] and women [p = 0.005; OR = 1.3 (1.1-1.5)] while increasing quartiles of hip significantly decreased the prevalence for men [p = 0.005; OR = 0.8 (0.6-0.9)] and women [p = 0.04; OR = 0.8 (0.7-0.9)]. Data on education level and physical activity did not affect the model. Conclusion: Increased BMI is associated with increased prevalence of coronary artery calcification and the distribution of fat modifies this risk. Our results suggest that gluteofemoral adipose tissue (hip) counteracts the negative effects associated with BMI and abdominal adipose tissue (waist).
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