683 research outputs found

    TEAD and YAP regulate the enhancer network of human embryonic pancreatic progenitors.

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    The genomic regulatory programmes that underlie human organogenesis are poorly understood. Pancreas development, in particular, has pivotal implications for pancreatic regeneration, cancer and diabetes. We have now characterized the regulatory landscape of embryonic multipotent progenitor cells that give rise to all pancreatic epithelial lineages. Using human embryonic pancreas and embryonic-stem-cell-derived progenitors we identify stage-specific transcripts and associated enhancers, many of which are co-occupied by transcription factors that are essential for pancreas development. We further show that TEAD1, a Hippo signalling effector, is an integral component of the transcription factor combinatorial code of pancreatic progenitor enhancers. TEAD and its coactivator YAP activate key pancreatic signalling mediators and transcription factors, and regulate the expansion of pancreatic progenitors. This work therefore uncovers a central role for TEAD and YAP as signal-responsive regulators of multipotent pancreatic progenitors, and provides a resource for the study of embryonic development of the human pancreas

    International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe

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    In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible

    Behaviour patterns preceding a railway suicide: Explorative study of German Federal Police officers' experiences

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    <p>Abstract</p> <p>Background</p> <p>Constant high-level numbers of railway suicides indicate that prevention strategies against railway suicides are urgently needed. The main question of the present study was whether pre-crash railway suicide behaviour can be identified, using German Federal Police officers experience with suicidal events in railway related environments.</p> <p>Methods</p> <p>To collect information on pre-crash railway suicide behaviour, a questionnaire was used and made available on the German Federal Police intranet. A total of 202 subjects (mean age: 41 years, sex: 84.9% male) were included in the analysis. Multivariate logistic regression analyses were performed to predict the prevention of suicide (first model) or demand for counselling (second model) as outcomes. Sex, age, years of service, number of experienced suicides, suicides personally observed, information on suicides obtained from witnesses and finally either counselling/debriefing (first model) or whether officers had prevented a suicide (second model) were used as predictors.</p> <p>Results</p> <p>A considerable proportion of police officers reported behavioural patterns preceding a suicide. Half of them observed the dropping or leaving behind of personal belongings or the avoidance of eye contact, more than a third erratic gesture, mimic or movement. Erratic communication patterns and general confusion were each reported by about one quarter. One fifth indicated the influence of alcohol. Less frequently observed behaviour was aimlessly wandering (14.3%) and out of the ordinary clothing (4%). About one third of all railway suicide victims committed suicide in stations. Of those, 70% had chosen an eminent spot. The multivariate logistic regression model using prevented suicides as the outcome identified the number of suicides experienced, counselling/debriefing and having personally observed a suicide as variables with significant impact. The model using counselling/debriefing as the outcome identified age and having prevented a suicide as variables with a significant association.</p> <p>Conclusions</p> <p>Our results provide evidence that railway suicides are preceded by identifiable behavioural patterns. This emphasizes the importance of educational efforts, taking into account the knowledge and skills of experienced police officers.</p

    An integrated MR/PET system: prospective applications

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    Radiology is strongly depending on medical imaging technology and consequently directing technological progress. A novel technology can only be established, however, if improved diagnostic accuracy influence on therapeutic management and/or overall reduced cost can be evidenced. It has been demonstrated recently that Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) can technologically be integrated into one single hybrid system. Some scientific arguments on the benefits are obvious, e.g., that simultaneous imaging of morphological and functional information will improve tissue characterization. However, crossfire of questions still remains: What unmet radiological needs are addressed by the novel system? What level of hardware integration is reasonable, or would software-based image co-registration be sufficient? Will MR/PET achieve higher diagnostic accuracy compared to separate imaging? What is the added value compared to other hybrid imaging modalities like PET/CT? And finally, is the system economically reasonable and has the potential to reduce overall costs for therapy planning and monitoring? This article tries to highlight some perspectives of applying an integrated MR/PET system for simultaneous morphologic and functional imaging

    Stabilization of Peptide Vesicles by Introducing Inter-Peptide Disulfide Bonds

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    PURPOSE: Previously, we have shown that the amphiphilic oligopeptide SA2 (Ac-Ala-Ala-Val-Val-Leu-Leu-Leu-Trp-Glu-Glu-COOH) spontaneously self-assemble into nano-sized vesicles in aqueous environment. Relative weak individual intermolecular interactions dominate such oligopeptide assemblies. In this study we aimed at improving the stability of such peptide vesicles by covalently crosslinking the oligopeptide vesicles using disulfide bonds. Two and three cysteines were introduced in the SA2 peptide sequence to allow crosslinking (Ac-Ala-Cys-Val-Cys-Leu-(Leu/Cys)-Leu-Trp-Glu-Glu-COOH). RESULTS: Upon disulfide formation the crosslinked vesicles remained stable under conditions that disrupted the non-crosslinked peptide vesicles. The stabilized vesicles were more closely examined in terms of particle size (distribution) using atomic force microscopy, cryogenic electron microscopy, as well as dynamic light scattering analysis, showing an average particle radius in number between 15 and 20 nm. Using entrapment of calcein it was shown that intermolecular crosslinking of peptides within the vesicles did not affect the permeability for calcein. CONCLUSION: Introduction of cysteines into the hydrophobic domain of the SA2 amphiphilic oligopeptides is a feasible strategy for crosslinking the peptide vesicles. Such small crosslinked oligopeptide vesicles may hold promise for drug delivery applications

    Association of daily tar and nicotine intake with incident myocardial infarction: Results from the population-based MONICA/KORA Augsburg Cohort Study 1984 - 2002

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    <p>Abstract</p> <p>Background</p> <p>Cigarette smoking has been shown to be one of the most important risk factors for cardiovascular diseases. However, little is known about cumulative effects of daily tar and nicotine intake on the risk of incident myocardial infarction (MI) so far. To bridge this gap, we conducted an analysis in a large prospective study from Southern Germany investigating associations of daily tar and nicotine intake with an incident MI event.</p> <p>Methods</p> <p>The study was based on 4,099 men and 4,197 women participating in two population-based MONICA Augsburg surveys between 1984 and 1990 and followed up within the KORA framework until 2002. During a mean follow-up of 13.3 years, a number of 307 men and 80 women developed an incident MI event. Relative risks were calculated as hazard ratios (HRs) estimated by Cox proportional hazards models adjusted for cardiovascular risk factors.</p> <p>Results</p> <p>In the present study, male regular smokers consumed on average more cigarettes per day than female regular smokers (20 versus 15) and had a higher tar and nicotine intake per day. In men, the MI risk compared to never-smokers increased with higher tar intake: HRs were 2.24 (95% CI 1.40-3.56) for 1-129 mg/day, 2.12 (95% CI 1.37-3.29) for 130-259 mg/day and 3.01 (95% CI 2.08-4.36) for ≥ 260 mg/day. In women, the corresponding associations were comparable but more pronounced for high tar intake (HR 4.67, 95% CI 1.76-12.40). Similar associations were observed for nicotine intake.</p> <p>Conclusions</p> <p>The present study based on a large population-based sample adds important evidence of cumulative effects of tar and nicotine intake on the risk of incident MI. Even low or medium tar and nicotine intake revealed substantial risk increases as compared to never-smokers. Therefore, reduction of tar and nicotine contents in cigarettes cannot be seen as a suitable public health policy in preventing myocardial infarction.</p

    Disulphide Bridges of Phospholipase C of Chlamydomonas reinhardtii Modulates Lipid Interaction and Dimer Stability

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    BACKGROUND: Phospholipase C (PLC) is an enzyme that plays pivotal role in a number of signaling cascades. These are active in the plasma membrane and triggers cellular responses by catalyzing the hydrolysis of membrane phospholipids and thereby generating the secondary messengers. Phosphatidylinositol-PLC (PI-PLC) specifically interacts with phosphoinositide and/or phosphoinositol and catalyzes specific cleavage of sn-3- phosphodiester bond. Several isoforms of PLC are known to form and function as dimer but very little is known about the molecular basis of the dimerization and its importance in the lipid interaction. PRINCIPAL FINDINGS: We herein report that, the disruption of disulphide bond of a novel PI-specific PLC of C. reinhardtii (CrPLC) can modulate its interaction affinity with a set of phospholipids and also the stability of its dimer. CrPLC was found to form a mixture of higher oligomeric states with monomer and dimer as major species. Dimer adduct of CrPLC disappeared in the presence of DTT, which suggested the involvement of disulphide bond(s) in CrPLC oligomerization. Dimer-monomer equilibrium studies with the isolated fractions of CrPLC monomer and dimer supported the involvement of covalent forces in the dimerization of CrPLC. A disulphide bridge was found to be responsible for the dimerization and Cys7 seems to be involved in the formation of the disulphide bond. This crucial disulphide bond also modulated the lipid affinity of CrPLC. Oligomers of CrPLC were also captured in in vivo condition. CrPLC was mainly found to be localized in the plasma membrane of the cell. The cell surface localization of CrPLC may have significant implication in the downstream regulatory function of CrPLC. SIGNIFICANCE: This study helps in establishing the role of CrPLC (or similar proteins) in the quaternary structure of the molecule its affinities during lipid interactions

    Deep Sequencing of MYC DNA-Binding Sites in Burkitt Lymphoma

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    BACKGROUND: MYC is a key transcription factor involved in central cellular processes such as regulation of the cell cycle, histone acetylation and ribosomal biogenesis. It is overexpressed in the majority of human tumors including aggressive B-cell lymphoma. Especially Burkitt lymphoma (BL) is a highlight example for MYC overexpression due to a chromosomal translocation involving the c-MYC gene. However, no genome-wide analysis of MYC-binding sites by chromatin immunoprecipitation (ChIP) followed by next generation sequencing (ChIP-Seq) has been conducted in BL so far. METHODOLOGY/PRINCIPAL FINDINGS: ChIP-Seq was performed on 5 BL cell lines with a MYC-specific antibody giving rise to 7,054 MYC-binding sites after bioinformatics analysis of a total of approx. 19 million sequence reads. In line with previous findings, binding sites accumulate in gene sets known to be involved in the cell cycle, ribosomal biogenesis, histone acetyltransferase and methyltransferase complexes demonstrating a regulatory role of MYC in these processes. Unexpectedly, MYC-binding sites also accumulate in many B-cell relevant genes. To assess the functional consequences of MYC binding, the ChIP-Seq data were supplemented with siRNA- mediated knock-downs of MYC in BL cell lines followed by gene expression profiling. Interestingly, amongst others, genes involved in the B-cell function were up-regulated in response to MYC silencing. CONCLUSION/SIGNIFICANCE: The 7,054 MYC-binding sites identified by our ChIP-Seq approach greatly extend the knowledge regarding MYC binding in BL and shed further light on the enormous complexity of the MYC regulatory network. Especially our observations that (i) many B-cell relevant genes are targeted by MYC and (ii) that MYC down-regulation leads to an up-regulation of B-cell genes highlight an interesting aspect of BL biology
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