410 research outputs found

    Adult Living Donor Liver Transplantation with ABO-Incompatible Grafts: A German Single Center Experience

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    Adult living donor liver transplantations (ALDLTs) across the ABO blood group barrier have been reported in Asia, North Americas, and Europe, but not yet in Germany. Several strategies have been established to overcome the detrimental effects that are attached with such a disparity between donor and host, but no gold standard has yet emerged. Here, we present the first experiences with three ABO-incompatible adult living donor liver transplantations in Germany applying different immunosuppressive strategies. Four patient-donor couples were considered for ABO-incompatible ALDLT. In these patients, resident ABO blood group antibodies (isoagglutinins) were depleted by plasmapheresis or immunoadsorption and replenishment was inhibited by splenectomy and/or B-cell-targeted immunosuppression. Despite different treatments ALDLT could safely be performed in three patients and all patients had good initial graft function without signs for antibody-mediated rejection (AMR). Two patients had long-term graft survival with stable graft function. We thus propose the feasibility of ABO-incompatible ALDLT with these protocols and advocate further expansion of ABO incompatible ALDLT in multicenter trials to improve efficacy and safety

    Regulation of human cytomegalovirus transcription in latency: beyond the major immediate-early promoter.

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    Lytic infection of differentiated cell types with human cytomegalovirus (HCMV) results in the temporal expression of between 170-200 open reading frames (ORFs). A number of studies have demonstrated the temporal regulation of these ORFs and that this is orchestrated by both viral and cellular mechanisms associated with the co-ordinated recruitment of transcription complexes and, more recently, higher order chromatin structure. Importantly, HCMV, like all herpes viruses, establishes a lifelong latent infection of the host--one major site of latency being the undifferentiated haematopoietic progenitor cells resident in the bone marrow. Crucially, the establishment of latency is concomitant with the recruitment of cellular enzymes that promote extensive methylation of histones bound to the major immediate early promoter. As such, the repressive chromatin structure formed at the major immediate early promoter (MIEP) elicits inhibition of IE gene expression and is a major factor involved in maintenance of HCMV latency. However, it is becoming increasingly clear that a distinct subset of viral genes is also expressed during latency. In this review, we will discuss the mechanisms that control the expression of these latency-associated transcripts and illustrate that regulation of these latency-associated promoters is also subject to chromatin mediated regulation and that the instructive observations previously reported regarding the negative regulation of the MIEP during latency are paralleled in the regulation of latent gene expression

    Why did they do that?: the methodology of reasons for action

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    ‘Why did they do that?’ is one of the most common questions in International Relations. However, we cannot access other people’s reasons for action the same way that we perceive our own; we cannot introspect the reasons of other actors. This paper provides a unifying framework that delineates different types of knowledge claims regarding reason attribution. There are three possible methodological responses: (1) assume a possible reason and explain behavior in terms of that reason; (2) avoid the direct attribution of reason to individuals and locate explanatory leverage at an analytical level beyond the individual actor reason; and (3) use empirical evidence to adjudicate between possible reasons. Excessive skepticism of evidence of reasons lessens our understanding of the causes of action. When using empirical evidence, contrary to existing arguments, the paper shows that private settings do not systematically favor the true revelation of reasons. The paper also proposes a general principle, consilience, that allows evaluation of empirical claims of reason attribution that subsumes several existing methodological considerations, organizes them, and gives a consistent means of choosing between alternative reason attributions

    Genome-wide analysis of regions similar to promoters of histone genes

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    Background: The purpose of this study is to: i) develop a computational model of promoters of human histone-encoding genes (shortly histone genes), an important class of genes that participate in various critical cellular processes, ii) use the model so developed to identify regions across the human genome that have similar structure as promoters of histone genes; such regions could represent potential genomic regulatory regions, e.g. promoters, of genes that may be coregulated with histone genes, and iii/ identify in this way genes that have high likelihood of being coregulated with the histone genes. Results: We successfully developed a histone promoter model using a comprehensive collection of histone genes. Based on leave-one-out cross-validation test, the model produced good prediction accuracy (94.1% sensitivity, 92.6% specificity, and 92.8% positive predictive value). We used this model to predict across the genome a number of genes that shared similar promoter structures with the histone gene promoters. We thus hypothesize that these predicted genes could be coregulated with histone genes. This hypothesis matches well with the available gene expression, gene ontology, and pathways data. Jointly with promoters of the above-mentioned genes, we found a large number of intergenic regions with similar structure as histone promoters. Conclusions: This study represents one of the most comprehensive computational analyses conducted thus far on a genome-wide scale of promoters of human histone genes. Our analysis suggests a number of other human genes that share a high similarity of promoter structure with the histone genes and thus are highly likely to be coregulated, and consequently coexpressed, with the histone genes. We also found that there are a large number of intergenic regions across the genome with their structures similar to promoters of histone genes. These regions may be promoters of yet unidentified genes, or may represent remote control regions that participate in regulation of histone and histone-coregulated gene transcription initiation. While these hypotheses still remain to be verified, we believe that these form a useful resource for researchers to further explore regulation of human histone genes and human genome. It is worthwhile to note that the regulatory regions of the human genome remain largely un-annotated even today and this study is an attempt to supplement our understanding of histone regulatory regions.Statistic

    Small Molecule Inhibited Parathyroid Hormone Mediated cAMP Response by N–Terminal Peptide Binding

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    Ligand binding to certain classes of G protein coupled receptors (GPCRs) stimulates the rapid synthesis of cAMP through G protein. Human parathyroid hormone (PTH), a member of class B GPCRs, binds to its receptor via its N–terminal domain, thereby activating the pathway to this secondary messenger inside cells. Presently, GPCRs are the target of many pharmaceuticals however, these drugs target only a small fraction of structurally known GPCRs (about 10%). Coordination complexes are gaining interest due to their wide applications in the medicinal field. In the present studies we explored the potential of a coordination complex of Zn(II) and anthracenyl–terpyridine as a modulator of the parathyroid hormone response. Preferential interactions at the N–terminal domain of the peptide hormone were manifested by suppressed cAMP generation inside the cells. These observations contribute a regulatory component to the current GPCR–cAMP paradigm, where not the receptor itself, but the activating hormone is a target. To our knowledge, this is the first report about a coordination complex modulating GPCR activity at the level of deactivating its agonist. Developing such molecules might help in the control of pathogenic PTH function such as hyperparathyroidism, where control of excess hormonal activity is essentially required
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