55 research outputs found

    The Challenges and Opportunities of Analogue Game-Based Learning

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    The report will be built on best existing practice in the area of game-based teaching and assessment from experts from all over Europe. It will include materials, resources, research and documented case studies of game-based approaches to teaching. Also, it will describe the challenges experts were facing during implementation of the practice and an articulated set of advice on how to confront the above challenges

    3640 Unique EST Clusters from the Medaka Testis and Their Potential Use for Identifying Conserved Testicular Gene Expression in Fish and Mammals

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    BACKGROUND: The fish medaka is the first vertebrate capable of full spermatogenesis in vitro from self-renewing spermatogonial stem cells to motile test-tube sperm. Precise staging and molecular dissection of this process has been hampered by the lack of suitable molecular markers. METHODOLOGY AND PRINCIPAL FINDINGS: We have generated a normalized medaka testis cDNA library and obtained 7040 high quality sequences representing 3641 unique gene clusters. Among these, 1197 unique clusters are homologous to known genes, and 2444 appear to be novel genes. Ontology analysis shows that the 1197 gene products are implicated in diverse molecular and cellular processes. These genes include markers for all major types of testicular somatic and germ cells. Furthermore, markers were identified for major spermatogenic stages ranging from spermatogonial stem cell self-renewal to meiosis entry, progression and completion. Intriguingly, the medaka testis expresses at least 13 homologs of the 33 mouse X-chromosomal genes that are enriched in the testis. More importantly, we show that key components of several signaling pathways known to be important for testicular function in mammals are well represented in the medaka testicular EST collection. CONCLUSIONS/SIGNIFICANCE: Medaka exhibits a considerable similarity in testicular gene expression to mammals. The medaka testicular EST collection we obtained has wide range coverage and will not only consolidate our knowledge on the comparative analysis of known genes' functions in the testis but also provide a rich resource to dissect molecular events and mechanism of spermatogenesis in vivo and in vitro in medaka as an excellent vertebrate model

    Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

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    Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

    Alternative splicing and transcriptome profiling of experimental autoimmune encephalomyelitis using genome-wide exon arrays

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    BACKGROUND: Multiple Sclerosis (MS) is a chronic inflammatory disease causing demyelination and nerve loss in the central nervous system. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS that is widely used to investigate complex pathogenic mechanisms. Transcriptional control through isoform selection and mRNA levels determines pathway activation and ultimately susceptibility to disease. METHODOLOGY/PRINCIPAL FINDINGS: We have studied the role of alternative splicing and differential expression in lymph node cells from EAE-susceptible Dark Agouti (DA) and EAE-resistant Piebald Virol Glaxo.AV1 (PVG) inbred rat strains using Affymetrix Gene Chip Rat Exon 1.0 ST Arrays. Comparing the two strains, we identified 11 differentially spliced and 206 differentially expressed genes at day 7 post-immunization, as well as 9 differentially spliced and 144 differentially expressed genes upon autoantigen re-stimulation. Functional clustering and pathway analysis implicate genes for glycosylation, lymphocyte activation, potassium channel activity and cellular differentiation in EAE susceptibility. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that alternative splicing occurs during complex disease and may govern EAE susceptibility. Additionally, transcriptome analysis not only identified previously defined EAE pathways regulating the immune system, but also novel mechanisms. Furthermore, several identified genes overlap known quantitative trait loci, providing novel causative candidate targets governing EAE

    Fine-mapping genomic loci refines bipolar disorder risk genes

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    Bipolar disorder (BD) is a heritable mental illness with complex etiology. While the largest published genome-wide association study identified 64 BD risk loci, the causal SNPs and genes within these loci remain unknown. We applied a suite of statistical and functional fine-mapping methods to these loci, and prioritized 22 likely causal SNPs for BD. We mapped these SNPs to genes, and investigated their likely functional consequences by integrating variant annotations, brain cell-type epigenomic annotations, brain quantitative trait loci, and results from rare variant exome sequencing in BD. Convergent lines of evidence supported the roles of SCN2A, TRANK1, DCLK3, INSYN2B, SYNE1, THSD7A, CACNA1B, TUBBP5, PLCB3, PRDX5, KCNK4, AP001453.3, TRPT1, FKBP2, DNAJC4, RASGRP1, FURIN, FES, YWHAE, DPH1, GSDMB, MED24, THRA, EEF1A2, and KCNQ2 in BD. These represent promising candidates for functional experiments to understand biological mechanisms and therapeutic potential. Additionally, we demonstrated that fine-mapping effect sizes can improve performance and transferability of BD polygenic risk scores across ancestrally diverse populations, and present a high-throughput fine-mapping pipeline (https://github.com/mkoromina/SAFFARI)

    Association of Glycemic Indices (Hyperglycemia, Glucose Variability, and Hypoglycemia) with Oxidative Stress and Diabetic Complications

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    Oxidative stress (OS) is defined as a disturbance in the prooxidant-antioxidant balance of the cell, in favor of the former, which results in the antioxidant capacity of the cell to be overpowered. Excess reactive oxygen species (ROS) production is very harmful to cell constituents, especially proteins, lipids, and DNA, thus causing damage to the cell. Oxidative stress has been associated with a variety of pathologic conditions, including diabetes mellitus (DM), cancer, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and accelerated aging. Regarding DM specifically, previous experimental and clinical studies have pointed to the fact that oxidative stress probably plays a major role in the pathogenesis and development of diabetic complications. It is postulated that hyperglycemia induces free radicals and impairs endogenous antioxidant defense systems through several different mechanisms. In particular, hyperglycemia promotes the creation of advanced glycation end-products (AGEs), the activation of protein kinase C (PKC), and the hyperactivity of hexosamine and sorbitol pathways, leading to the development of insulin resistance, impaired insulin secretion, and endothelial dysfunction, by inducing excessive ROS production and OS. Furthermore, glucose variability has been associated with OS as well, and recent evidence suggests that also hypoglycemia may be playing an important role in favoring diabetic vascular complications through OS, inflammation, prothrombotic events, and endothelial dysfunction. The association of these diabetic parameters (i.e., hyperglycemia, glucose variability, and hypoglycemia) with oxidative stress will be reviewed here. © 2020 Eleftheria Papachristoforou et al

    Regulation of postabsorptive and postprandial glucose metabolism by insulin-dependent and insulin-independent mechanisms: An integrative approach

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    Glucose levels in blood must be constantly maintained within a tight physiological range to sustain anabolism. Insulin regulates glucose homeostasis via its effects on glucose production from the liver and kidneys and glucose disposal in peripheral tissues (mainly skeletal muscle). Blood levels of glucose are regulated simultaneously by insulin-mediated rates of glucose production from the liver (and kidneys) and removal from muscle; adipose tissue is a key partner in this scenario, providing nonesterified fatty acids (NEFA) as an alternative fuel for skeletal muscle and liver when blood glucose levels are depleted. During sleep at night, the gradual development of insulin resistance, due to growth hormone and cortisol surges, ensures that blood glucose levels will be maintained within normal levels by: (a) switching from glucose to NEFA oxidation in mus-cle; (b) modulating glucose production from the liver/kidneys. After meals, several mechanisms (sequence/composition of meals, gastric emptying/intestinal glucose absorption, gastrointestinal hormones, hyperglycemia mass action effects, insulin/glucagon secretion/action, de novo lipogene-sis and glucose disposal) operate in concert for optimal regulation of postprandial glucose fluctua-tions. The contribution of the liver in postprandial glucose homeostasis is critical. The liver is pref-erentially used to dispose over 50% of the ingested glucose and restrict the acute increases of glucose and insulin in the bloodstream after meals, thus protecting the circulation and tissues from the adverse effects of marked hyperglycemia and hyperinsulinemia. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Serum levels of novel adipokines in patients with acute ischemic stroke: Potential contribution to diagnosis and prognosis

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    This study evaluated serum levels of novel adipokines in acute ischemic stroke (AIS) and their association with prognosis. We enrolled 168 patients with AIS and 58 stroke-free age- and sex-matched individuals (controls). Clinical parameters, carotid ultrasound, metabolic profile, vaspin, apelin, visfatin, and ghrelin were assayed. Stroke-patients were sampled at hospital admission and were prospectively followed-up (median 16 months) for the cardiovascular endpoint (cardiovascular death/stroke/myocardial infarction). At admission, stroke-patients appeared with higher levels of systolic blood pressure, hsCRP and worse metabolic profile (p < 0.05), (p > 0.05). Compared to controls, AIS group had significantly higher serum concentrations of visfatin (22.92 ± 9.72 ng/ml vs 16.56 ± 7.82 ng/ml, p = 0.006) and lower of vaspin (0.94 ± 0.43 ng/ml vs 1.84 ± 0.82 ng/ml, p = 0.019) and ghrelin (3.47 ± 1.44 ng/ml vs 5.93 ± 2.78 ng/ml, p < 0.001), while apelin did not differ between groups. Similar differences in adipokines were found between stroke subgroups with and without significant ipsilateral carotid stenosis (>50%) (p < 0.05). In stepwise logistic regression analysis adjusted for diabetes, hypertension, dyslipidemia and age, visfatin (p = 0.026) and ghrelin (p = 0.012) proved to be independent predictors of AIS. During follow-up, 27 patients achieved cardiovascular endpoint. In addition to coronary artery disease and NIHSS score, visfatin serum levels was associated with cardiovascular endpoint (HR: 1.255, 95% CI: 1.025-1.576). Our results suggested the association of AIS with higher visfatin and lower vaspin and ghrelin serum levels. Visfatin levels can be a predictor of cardiovascular mortality and morbidity in AIS. © 2014 Elsevier Inc

    Thyroid hormones are positively associated with insulin resistance early in the development of type 2 diabetes

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    Thyroid hormones have generally been found normal in diabetic patients. The question of whether variation within the euthyroid range influences insulin sensitivity in type 2 diabetes remains to be established. To investigate this, a meal was given to four groups: 17 healthy volunteers (controls), 22 first-degree relatives of type 2 diabetic subjects (relatives), 15 subjects with impaired glucose tolerance (IGT), and 24 subjects with overt type 2 diabetes (DM). Blood was drawn for 360 min for measurements of glucose and insulin. Plasma-free-T4(FT4) and plasma-free-T3(FT3) levels were measured. Fasting and postprandial insulin resistance was assessed by HOMA-IR and ISI indices, respectively. FT4 levels were found to be lower in controls (13.73 ± 0.48 pmol/l) than relatives, IGT, and DM (15.33 ± 0.52, 16.13 ± 0.65, and 17.7 ± 0.85 pmol/l, respectively, P = 0.007). FT3 levels were lower in controls (3.68 ± 0.09 pmol/l) than in relatives, IGT, and DM (4.35 ± 0.1, 4.8 ± 0.067, and 4.87 ± 0.11 pmol/l, respectively, P = 0.001). HOMA-IR was positively associated with FT4 and FT3 levels (β-co-efficient = 1.876 ± 0.476, P = 0.001; and 0.406 ± 0.090, P = 0.001, respectively). ISI was negatively associated with FT4 and FT3 levels (β-co-efficient = -0.051 ± 0.009, P = 0.001 and -0.009 ± 0.002, P = 0.001, respectively). In conclusion, increases of thyroid hormone levels within the normal range associate positively with insulin resistance. These data suggest that thyroid hormones may be part of the pathogenetic mechanism to explain metabolic derangement early in the development of type 2 diabetes. © 2010 Springer Science+Business Media, LLC

    Insufficient glucocorticoid receptor signaling and flattened salivary cortisol profile are associated with metabolic and inflammatory indices in type 2 diabetes

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    Purpose: Impaired negative feedback and hyperactivation of the hypothalamic–pituitary–adrenal (HPA) axis characterizes type 2 diabetes mellitus (T2DM). The glucocorticoid receptor (GR) is a key mediator of HPA axis negative feedback; however, its role in linking hypercortisolemia and T2DM-associated hyperglycemia, hyperlipidemia and inflammation is not yet known. Methods: In peripheral mononuclear cells (PBMC) from 31 T2DM patients and 24 healthy controls, we measured various GR-signaling parameters such as phosphorylated GR (pGR-S211), GRα/GRβ gene expression and GC-sensitivity [using the basal and dexamethasone (DEX)-induced leucine zipper (GILZ) and FK506 binding-protein (FKBP5) mRNA levels as well as the basal interleukin (IL)-1β protein levels]. Diurnal salivary cortisol curve parameters such as the cortisol awaking response (CAR) and area under the curve (AUCtotal and AUCi) as well as inflammatory and metabolic indices were also determined. Results: T2DM patients exhibited diminished pGR-S211 protein content, increased GRβ, decreased basal GILZ and FKBP5 mRNA levels and increased IL-1β levels. Flattened DEX-induced GILZ and FKBP5 response curves and a flattened salivary cortisol profile characterized T2DM patients. Significant associations of GR measures and saliva cortisol curve parameters with biochemical and clinical characteristics were found. Conclusion: Our novel data implicate an insufficient GR signaling in PBMCs in T2DM patients and HPA axis dysfunction. The significant associations of GR-signaling parameters with inflammatory and metabolic indices implicate that GR may be the critical link between HPA axis dysfunction, hypercortisolemia and diabetes-associated metabolic disturbances. Our findings provide significant insights into the contribution of GR-mediated mechanisms in T2DM aetiopathology and therapy. © 2020, Italian Society of Endocrinology (SIE)
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