Untersuchungen zur transkriptionellen Regulation des Chromogranin A Gens und seine Anwendung zum zellspezifischen therapeutischen Gentransfer in neuroendokrine Pankreastumorzellen

Die Therapieoptionen zur Behandlung metastasierter neuroendokriner Tumore sind bisher ineffektiv. Der regulierte Gentransfer könnte eine weitere Möglichkeit eröffnen, metastasierte neuroendokrine Tumore zu behandeln. In der vorliegenden Arbeit wurde daher die transkriptionelle Regulation von Chromogranin A als Basis zur Gentherapie durch eine regulierte Genexpression in neuroendokrinen Tumorzellen untersucht. Chromogranin A (CgA) besitzt vielfältige Funktionen in der regulierten Sekretion von Peptidhormonen und Neurotransmittern. Es wird spezifisch in nahezu allen endokrinen und neuroendokrinen Zellen exprimiert und diagnostisch als Marker bei neuroendokrinen Tumorerkrankungen eingesetzt. Zur Identifizierung wichtiger cis-regulatorischer Elemente im humanen Chromogranin A Promotor wurde die 5'-flankierende Sequenz des hCgA Gens auf putative Transkriptionsfaktorbindungsseiten untersucht und eine Interspezieshomologie des humanen, bovinen, murinen und des Rattenchromogranin A Promotors erstellt. Es fand sich eine konservierte Sequenzhomologie in den proximalen Chromogranin A Promotorbereichen mit den putativen Transkriptionsfaktor-Bindungsseiten Egr-1/Sp1, CRE und TATA-Box. Untersuchungen zur zelltypspezifischen Regulation des Chromogranin A Promotors ergaben eine starke Expression von Chromogranin A in neuroendokrinen Pankreastumorzellen BON-1 und der Lungenkarzinomzelllinie EPLC 32M1, während sich nur eine geringe Expression in nicht neuroendokrinen Zelllinien wie z.B. der Fibroblastenzelllinie MSTO-211H zeigte. Die neuroendokrin-spezifische Regulation wurde im hCgA Promotor durch das im proximalen Promotorbereich gelegene CRE vermittelt. Ebenso konnte gezeigt werden, dass Gastrin und cAMP den hCgA Promotor über das CRE regulieren. Unter Anwendung des charakterisierten hCgA Promotors konnte die funktionelle Expression des Natriumjodidsymporters unter der Kontrolle des humanen CgA Promotors in BON 1 Zellen nachgewiesen werden. Dies bildet einen vielversprechenden neuen Therapieansatz, durch einen regulierten Gentransfer neuroendokrine Tumorzellen mittels einer Radiojodtherapie in Analogie zu Schilddrüsenkarzinomen zu behandeln

Assessment of a conduction-repolarisation metric to predict Arrhythmogenesis in right ventricular disorders

Background: The re-entry vulnerability index (RVI) is a recently proposed activation-repolarization metric designed to quantify tissue susceptibility to re-entry. This study aimed to test feasibility of an RVI-based algorithm to predict the earliest endocardial activation site of ventricular tachycardia (VT) during electrophysiological studies and occurrence of haemodynamically significant ventricular arrhythmias in follow-up. Methods: Patients with Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) (n = 11), Brugada Syndrome (BrS) (n = 13) and focal RV outflow tract VT (n = 9) underwent programmed stimulation with unipolar electrograms recorded from a non-contact array in the RV. Results: Lowest values of RVI co-localised with VT earliest activation site in ARVC/BrS but not in focal VT. The distance between region of lowest RVI and site of VT earliest site (D min ) was lower in ARVC/BrS than in focal VT (6.8 ± 6.7 mm vs 26.9 ± 13.3 mm, p = 0.005). ARVC/BrS patients with inducible VT had lower Global-RVI (RVI G ) than those who were non-inducible (−54.9 ± 13.0 ms vs −35.9 ± 8.6 ms, p = 0.005) or those with focal VT (−30.6 ± 11.5 ms, p = 0.001). Patients were followed up for 112 ± 19 months. Those with clinical VT events had lower Global-RVI than both ARVC and BrS patients without VT (−54.5 ± 13.5 ms vs −36.2 ± 8.8 ms, p = 0.007) and focal VT patients (−30.6 ± 11.5 ms, p = 0.002). Conclusions: RVI reliably identifies the earliest RV endocardial activation site of VT in BrS and ARVC but not focal ventricular arrhythmias and predicts the incidence of haemodynamically significant arrhythmias. Therefore, RVI may be of value in predicting VT exit sites and hence targeting of re-entrant arrhythmias

Questionnaire study to gain an insight into the manufacturing and fitting process of artificial eyes in children: an ocularist perspective

Purpose To gain an insight into the manufacturing and fitting of artificial eyes in children and potential improvements to the process. Method An online qualitative survey was distributed to 39 ocularists/prosthetists in Europe and Canada. Participants were recruited through purposive sampling, specifically maximum variation sampling from the researcher’s contacts and an online search. Results The findings highlighted the current impression technique as being the most difficult yet most important part of the current process for both the ocularist and child patient. Negatively affecting obtaining a good impression, the child patients distress can be reduced by their parents by providing encouragement, reassurance, practicing the insertion and removal of the artificial eye and being matter of fact. Whilst improvements to the current process provided mixed views, the incorporation of current technology was perceived as not being able to meet the requirements to produce aesthetically pleasing artificial eyes. Conclusion The current artificial eye process can be seen as an interaction with its success being dependent on the child patient’s acceptance and adjustment which is dependent on the factors associated to the process. Investigation into the needs of the patient and whether technology can improve the process are the next steps in its advancement

Von Bezold assimilation effect reverses in stereoscopic conditions

Lightness contrast and lightness assimilation are opposite phenomena: in contrast, grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in assimilation, the opposite occurs. The question is: which visual process favours the occurrence of one phenomenon over the other? Researchers provided three answers to this question. The first asserts that both phenomena are caused by peripheral processes; the second attributes their occurrence to central processes; and the third claims that contrast involves central processes, whilst assimilation involves peripheral ones. To test these hypotheses, an experiment on an IT system equipped with goggles for stereo vision was run. Observers were asked to evaluate the lightness of a grey target, and two variables were systematically manipulated: (i) the apparent distance of the inducers; and (ii) brightness of the inducers. The retinal stimulation was kept constant throughout, so that the peripheral processes remained the same. The results show that the lightness of the target depends on both variables. As the retinal stimulation was kept constant, we conclude that central mechanisms are involved in both lightness contrast and lightness assimilation

A database of microRNA expression patterns in Xenopus laevis

MicroRNAs (miRNAs) are short, non-coding RNAs around 22 nucleotides long. They inhibit gene expression either by translational repression or by causing the degradation of the mRNAs they bind to. Many are highly conserved amongst diverse organisms and have restricted spatio-temporal expression patterns during embryonic development where they are thought to be involved in generating accuracy of developmental timing and in supporting cell fate decisions and tissue identity. We determined the expression patterns of 180 miRNAs in Xenopus laevis embryos using LNA oligonucleotides. In addition we carried out small RNA-seq on different stages of early Xenopus development, identified 44 miRNAs belonging to 29 new families and characterized the expression of 5 of these. Our analyses identified miRNA expression in many organs of the developing embryo. In particular a large number were expressed in neural tissue and in the somites. Surprisingly none of the miRNAs we have looked at show expression in the heart. Our results have been made freely available as a resource in both XenMARK and Xenbase

Antonio Gramsci’s impact on critical pedagogy

This paper provides an account of Antonio Gramsci’s impact on the area of critical pedagogy. It indicates the Gramscian influence on the thinking of major exponents of the field. It foregrounds Gramsci's ideas and then indicates how they have been taken up by a selection of critical pedagogy exponents who were chosen on the strength of their identification and engagement with Gramsci's ideas, some of them even having written entire essays on Gramsci. The essay concludes with a discussion concerning an aspect of Gramsci's concerns, the question of powerful knowledge, which, in the present author's view, provides a formidable challenge to critical pedagogues.peer-reviewe

Altruism can proliferate through group/kin selection despite high random gene flow

The ways in which natural selection can allow the proliferation of cooperative behavior have long been seen as a central problem in evolutionary biology. Most of the literature has focused on interactions between pairs of individuals and on linear public goods games. This emphasis led to the conclusion that even modest levels of migration would pose a serious problem to the spread of altruism in group structured populations. Here we challenge this conclusion, by analyzing evolution in a framework which allows for complex group interactions and random migration among groups. We conclude that contingent forms of strong altruism can spread when rare under realistic group sizes and levels of migration. Our analysis combines group-centric and gene-centric perspectives, allows for arbitrary strength of selection, and leads to extensions of Hamilton's rule for the spread of altruistic alleles, applicable under broad conditions.Comment: 5 pages, 2 figures. Supplementary material with 50 pages and 26 figure

Anti-tumour activity of bisphosphonates in preclinical models of breast cancer

There is increasing evidence of anti-tumour effects of bisphosphonates from pre-clinical studies, supporting a role for these drugs beyond their traditional use in treatment of cancer-induced bone disease. A range of model systems have been used to investigate the effects of different bisphosphonates on tumour growth, both in bone and at peripheral sites. Most of these studies conclude that bisphosphonates cause a reduction in tumour burden, but that early intervention and the use of high and/or repeated dosing is required. Successful eradication of cancer may only be achievable by targeting the tumour cells directly whilst also modifying the tumour microenvironment. In line with this, bisphosphonates are demonstrated to be particularly effective at reducing breast tumour growth when used in combination with agents that directly target cancer cells. Recent studies have shown that the effects of bisphosphonates on breast tumours are not limited to bone, and that prolonged anti-tumour effects may be achieved following their inclusion in combination therapy. This has opened the field to a new strand of bisphosphonate research, focussed on elucidating their effects on cells and components of the local, regional and distal tumour microenvironment. This review highlights the recent developments in relation to proposed anti-tumour effects of bisphosphonates reported from in vitro and in vivo models, and summarises the data from key breast cancer studies. Evidence for effects on different processes and cell types involved in cancer development and progression is discussed, and the main outstanding issues identified

Publishing and sharing multi-dimensional image data with OMERO

Imaging data are used in the life and biomedical sciences to measure the molecular and structural composition and dynamics of cells, tissues, and organisms. Datasets range in size from megabytes to terabytes and usually contain a combination of binary pixel data and metadata that describe the acquisition process and any derived results. The OMERO image data management platform allows users to securely share image datasets according to specific permissions levels: data can be held privately, shared with a set of colleagues, or made available via a public URL. Users control access by assigning data to specific Groups with defined membership and access rights. OMERO’s Permission system supports simple data sharing in a lab, collaborative data analysis, and even teaching environments. OMERO software is open source and released by the OME Consortium at www.openmicroscopy.org

Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions

The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions