218 research outputs found
Prototype Biology-Based Radiation Risk Module Project
Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis
Nitric Oxide Is an Upstream Signal of Vascular Endothelial Growth Factor-induced Extracellular Signal-regulated Kinase½ Activation in Postcapillary Endothelium
Abstract We recently demonstrated that nitric oxide (NO) significantly contributes to the mitogenic effect of vascular endothelial growth factor (VEGF), suggesting a role for the NO pathway in the signaling cascade following kinase-derivative receptor activation in vascular endothelium. The aim of this study was to investigate the intracellular pathways linked to VEGF/NO-induced endothelial cell proliferation. We assessed the activity of the mitogen-activated protein kinase (MAPK) that is specifically activated by growth factors, extracellular-regulated kinase (ERK½), on cultured microvascular endothelium isolated from coronary postcapillary venules. ERK½ was immunoprecipitated, and its activity was assessed with an immunocomplex kinase assay. In endothelial cells exposed for 5 min to the NO donor drug sodium nitroprusside at a concentration of 100 μm, ERK½ activity significantly increased. VEGF produced a time- and concentration-dependent activation of ERK½. Maximal activity was obtained after 5 min of stimulation at a concentration of 10 ng/ml. The specific MAPK kinase inhibitor PD 98059 abolished ERK½ activation and endothelial cell proliferation in a concentration-dependent manner in response to VEGF and sodium nitroprusside. The NO synthase inhibitorN ω-monomethyl-l-arginine, as well as the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, blocked the activation of ERK½ induced by VEGF, suggesting that NO and cGMP contributed to the VEGF-dependent ERK½ activation. These results demonstrate for the first time that kinase-derivative receptor activation triggers the NO synthase/guanylate cyclase pathway to activate the MAPK cascade and substantiates the hypothesis that the activation of ERK½ is necessary for VEGF-induced endothelial cell proliferation
Cardiovascular risk reduction in hypertensive black patients with left ventricular hypertrophy The life study
AbstractObjectivesWe report on a subanalysis of the effects of losartan and atenolol on cardiovascular events in black patients in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study.BackgroundThe LIFE study compared losartan-based to atenolol-based therapy in 9,193 hypertensive patients with left ventricular hypertrophy (LVH). Overall, the risk of the primary composite end point (cardiovascular death, stroke, myocardial infarction) was reduced by 13% (p = 0.021) with losartan, with similar blood pressure (BP) reduction in both treatment groups. There was a suggestion of interaction between ethnic background and treatment (p = 0.057).MethodsExploratory analyses were performed that placed LIFE study patients into black (n = 533) and non-black (n = 8,660) categories, overall, and in the U.S. (African American [n = 523]; non-black [n = 1,184]).ResultsA significant interaction existed between the dichotomized groups (black/non-black) and treatment (p = 0.005); a test for qualitative interaction was also significant (p = 0.016). The hazard ratio (losartan relative to atenolol) for the primary end point favored atenolol in black patients (1.666 [95% confidence interval (CI) 1.043 to 2.661]; p = 0.033) and favored losartan in non-blacks (0.829 [95% CI 0.733 to 0.938]; p = 0.003). In black patients, BP reduction was similar in both groups, and regression of electrocardiographic-LVH was greater with losartan.ConclusionsResults of the subanalysis are sufficient to generate the hypothesis that black patients with hypertension and LVH might not respond as favorably to losartan-based treatment as non-black patients with respect to cardiovascular outcomes, and do not support a recommendation for losartan as a first-line treatment for this purpose. The subanalysis is limited by the relatively small number of events
Digital play and the actualisation of the consumer imagination
In this article, the authors consider emerging consumer practices in digital virtual spaces. Building on constructions of consumer behavior as both a sense-making activity and a resource for the construction of daydreams, as well as anthropological readings of performance, the authors speculate that many performances during digital play are products of consumer fantasy. The authors develop an interpretation of the relationship between the real and the virtual that is better equipped to understand the movement between consumer daydreams and those practices actualized in the material and now also in digital virtual reality. The authors argue that digital virtual performances present opportunities for liminoid transformations through inversions, speculations, and playfulness acted out in aesthetic dramas. To illustrate, the authors consider specific examples of the theatrical productions available to consumers in digital spaces, highlighting the consumer imagination that feeds them, the performances they produce, and the potential for transformation in consumer-players
American College of Cardiology key data elements and definitions for measuring the clinical management and outcomes of patients with acute coronary syndromes.
Investigating the genetic architecture of dementia with Lewy bodies: a two-stage genome-wide association study
Background Dementia with Lewy bodies is the second most common form of dementia in elderly people but has been overshadowed in the research field, partly because of similarities between dementia with Lewy bodies, Parkinson’s disease, and Alzheimer’s disease. So far, to our knowledge, no large-scale genetic study of dementia with Lewy bodies has been done. To better understand the genetic basis of dementia with Lewy bodies, we have done a genome-wide association study with the aim of identifying genetic risk factors for this disorder.
Methods In this two-stage genome-wide association study, we collected samples from white participants of European ancestry who had been diagnosed with dementia with Lewy bodies according to established clinical or pathological criteria. In the discovery stage (with the case cohort recruited from 22 centres in ten countries and the controls derived from two publicly available database of Genotypes and Phenotypes studies [phs000404.v1.p1 and phs000982.v1.p1] in the USA), we performed genotyping and exploited the recently established Haplotype Reference Consortium panel as the basis for imputation. Pathological samples were ascertained following autopsy in each individual brain bank, whereas clinical samples were collected by clinical teams after clinical examination. There was no specific timeframe for collection of samples. We did association analyses in all participants with dementia with Lewy bodies, and also in only participants with pathological diagnosis. In the replication stage, we performed genotyping of significant and suggestive results from the discovery stage. Lastly, we did a meta-analysis of both stages under a fixed-effects model and used logistic regression to test for association in each stage.
Findings This study included 1743 patients with dementia with Lewy bodies (1324 with pathological diagnosis) and 4454 controls (1216 patients with dementia with Lewy bodies vs 3791 controls in the discovery stage; 527 vs 663 in the replication stage). Results confirm previously reported associations: APOE (rs429358; odds ratio [OR] 2·40, 95% CI 2·14–2·70; p=1·05 × 10–⁴⁸), SNCA (rs7681440; OR 0·73, 0·66–0·81; p=6·39 × 10–¹⁰), and GBA (rs35749011; OR 2·55, 1·88–3·46; p=1·78 × 10–⁹). They also provide some evidence for a novel candidate locus, namely CNTN1 (rs7314908; OR 1·51, 1·27–1·79; p=2·21 × 10–⁶); further replication will be important. Additionally, we estimate the heritable component of dementia with Lewy bodies to be about 36%.
Interpretation Despite the small sample size for a genome-wide association study, and acknowledging the potential biases from ascertaining samples from multiple locations, we present the most comprehensive and well powered genetic study in dementia with Lewy bodies so far. These data show that common genetic variability has a role in the disease
History, Commemoration, and Belief: Abraham Lincoln in American Memory, 1945-2001
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91765/1/Schuman-History_Commemoration_Belief.pd
A comprehensive screening of copy number variability in dementia with Lewy bodies
The role of genetic variability in dementia with Lewy bodies (DLB) is now indisputable; however, data regarding copy number variation (CNV) in this disease has been lacking. Here, we used whole-genome genotyping of 1454 DLB cases and 1525 controls to assess copy number variability. We used 2 algorithms to confidently detect CNVs, performed a case-control association analysis, screened for candidate CNVs previously associated with DLB-related diseases, and performed a candidate gene approach to fully explore the data. We identified 5 CNV regions with a significant genome-wide association to DLB; 2 of these were only present in cases and absent from publicly available databases: one of the regions overlapped LAPTM4B, a known lysosomal protein, whereas the other overlapped the NME1 locus and SPAG9. We also identified DLB cases presenting rare CNVs in genes previously associated with DLB or related neurodegenerative diseases, such as SNCA, APP, and MAPT. To our knowledge, this is the first study reporting genome-wide CNVs in a large DLB cohort. These results provide preliminary evidence for the contribution of CNVs in DLB risk. (C) 2019 Elsevier Inc. All rights reserved.Peer reviewe
Analysis of neurodegenerative disease-causing genes in dementia with Lewy bodies
Dementia with Lewy bodies (DLB) is a clinically heterogeneous disorder with a substantial burden on healthcare. Despite this, the genetic basis of the disorder is not well defined and its boundaries with other neurodegenerative diseases are unclear. Here, we performed whole exome sequencing of a cohort of 1118 Caucasian DLB patients, and focused on genes causative of monogenic neurodegenerative diseases. We analyzed variants in 60 genes implicated in DLB, Alzheimer's disease, Parkinson's disease, frontotemporal dementia, and atypical parkinsonian or dementia disorders, in order to determine their frequency in DLB. We focused on variants that have previously been reported as pathogenic, and also describe variants reported as pathogenic which remain of unknown clinical significance, as well as variants associated with strong risk. Rare missense variants of unknown significance were found in APP, CHCHD2, DCTN1, GRN, MAPT, NOTCH3, SQSTM1, TBK1 and TIA1. Additionally, we identified a pathogenic GRN p.Arg493* mutation, potentially adding to the diversity of phenotypes associated with this mutation. The rarity of previously reported pathogenic mutations in this cohort suggests that the genetic overlap of other neurodegenerative diseases with DLB is not substantial. Since it is now clear that genetics plays a role in DLB, these data suggest that other genetic loci play a role in this disease.Peer reviewe
Analysis of C9orf72 repeat expansions in a large international cohort of dementia with Lewy bodies
C9orf72 repeat expansions are a common cause of amyotrophic lateral sclerosis and frontotemporal dementia. To date, no large-scale study of dementia with Lewy bodies (DLB) has been undertaken to assess the role of C9orf72 repeat expansions in the disease. Here, we investigated the prevalence of C9orf72 repeat expansions in a large cohort of DLB cases and identified no pathogenic repeat expansions in neuropathologically or clinically defined cases, showing that C9orf72 repeat expansions are not causally associated with DLB. (C) 2016 Elsevier Inc. All rights reserved.Peer reviewe
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