68 research outputs found
The Knowledge Handling Notation: building an interface to enable design conversation diagnosis
Abstract: With the development of the Knowledge Handling Notation (KHN) we were able to provide a model for a notation that captures modes of knowledge handling and visualizes its dynamics in design conversations. The KHN functions as an interface between transcript and pattern analysis for researchers or coaches who aim at diagnosing knowledge handling in conversational interactions in general, and design reviews in particular. We applied the notation to different design review sessions and iterated on the coding, which is presented in a coding manual. A visualization of the coding shows the dynamics of the conversational interaction. We developed the Knowledge Handling Notation (KHN) by integrating Nonaka’s concept of externalization and combination, enriched with sub-categories that account for transitions between those activities. In that, KHN maps out design conversations focused on the dynamics of knowledge handling and thereby serve as an orientation system for knowledge handling interactions in the context of design conversations
Pediatric papillary tumors of the pineal region: to observe or to treat following gross total resection?
Introduction: Papillary tumors of the pineal region (PTPR) are rare brain tumors characterized by frequent local recurrences. Standardized treatment strategies are not yet defined. Case report: We present the case of a 3-year-old girl diagnosed with PTPR. Due to her young age, adjuvant radiotherapy was omitted after gross total tumor resection. Thirty-six months later, local tumor recurrence occurred. Considering the possible risks of secondary surgery, the recurrent tumor was irradiated with proton radiotherapy. Three months later, the tumor showed near-complete remission. Discussion: Based on this experience and other pediatric case reports from the literature, local radiotherapy might be suggested also after complete tumor resectio
Natural history of a medulloblastoma: 30months of wait and see in a child with a cerebellar incidentaloma
Introduction: With the increasing use of neuroimaging studies, the discovery of incidental neoplastic lesions is becoming more frequent. However, standard procedures are lacking, and little is known about their optimal management. Case Report: We here present the case of a boy with a cerebellar mass incidentally discovered on a CT scan performed after head trauma. In another scan performed after another incident of head trauma 14months earlier, the lesion could be seen after retrospective examination. In view of the asymptomatic clinical and stable radiological status and the presumed diagnosis of a low-grade glioma, a watch-and-wait strategy was elected. After clinical and radiological progression was observed, the tumour was resected, 2½ years after the initial imaging study. Histological evaluation revealed a WNT pathway-activated classical medulloblastoma. Discussion: To our knowledge, this is the first description of such a long natural history and pre-symptomatic period of a medulloblastoma. The long period of stability followed by a period of accelerated tumour growth is compatible with increasing biological aggressiveness, possibly related to the stepwise accumulation of genetic change
Planung als Element berufspraktischer Professionalisierung. Das Praxismodell der PPH Augustinum
Astrid Kohl, Andrea Scheer, Julia Seyss-Inquart und Elisabeth Sturm betonen den Fokus auf die Planung als Element der berufspraktischen Professionalisierung und geben Einblicke in den Aufbau der entsprechenden Planungskompetenzen im Rahmen des Praxismodells der PPH Augustinum. Mit zusammenfassenden Ergebnissen aus der Begleitforschung werden drei zentrale Entwicklungsfelder für die berufspraktische Professionalisierung berichtet und daraus resultierende weiterführende Fragen formuliert. (DIPF/Orig.
JProGO: a novel tool for the functional interpretation of prokaryotic microarray data using Gene Ontology information
A novel program suite was implemented for the functional interpretation of high-throughput gene expression data based on the identification of Gene Ontology (GO) nodes. The focus of the analysis lies on the interpretation of microarray data from prokaryotes. The three well established statistical methods of the threshold value-based Fisher's exact test, as well as the threshold value-independent Kolmogorov–Smirnov and Student's t-test were employed in order to identify the groups of genes with a significantly altered expression profile. Furthermore, we provide the application of the rank-based unpaired Wilcoxon's test for a GO-based microarray data interpretation. Further features of the program include recognition of the alternative gene names and the correction for multiple testing. Obtained results are visualized interactively both as a table and as a GO subgraph including all significant nodes. Currently, JProGO enables the analysis of microarray data from more than 20 different prokaryotic species, including all important model organisms, and thus constitutes a useful web service for the microbial research community. JProGO is freely accessible via the web at the following address
Subunits of ADA-two-A-containing (ATAC) or Spt-Ada-Gcn<sub>5</sub>-acetyltrasferase (SAGA) coactivator complexes enhance the acetyltransferase activity of GCN<sub>5</sub>
Histone acetyl transferases (HATs) play a crucial role in eukaryotes by regulating chromatin architecture and locus specific transcription. GCN5 (KAT2A) is a member of the GNAT (Gcn5-related N-acetyltransferase) family of HATs. In metazoans this enzyme is found in two functionally distinct coactivator complexes, SAGA (Spt Ada Gcn5 acetyltransferase) and ATAC (Ada Two A-containing). These two multiprotein complexes comprise complex-specific and shared subunits, which are organized in functional modules. The HAT module of ATAC is composed of GCN5, ADA2a, ADA3, and SGF29, whereas in the SAGA HAT module ADA2b is present instead of ADA2a. To better understand how the activity of human (h) hGCN5 is regulated in the two related, but different, HAT complexes we carried out in vitro HAT assays. We compared the activity of hGCN5 alone with its activity when it was part of purified recombinant hATAC or hSAGA HAT modules or endogenous hATAC or hSAGA complexes using histone tail peptides and full-length histones as substrates. We demonstrated that the subunit environment of the HAT complexes into which GCN5 incorporates determines the enhancement of GCN5 activity. On histone peptides we show that all the tested GCN5-containing complexes acetylate mainly histone H3K14. Our results suggest a stronger influence of ADA2b as compared with ADA2a on the activity of GCN5. However, the lysine acetylation specificity of GCN5 on histone tails or full-length histones was not changed when incorporated in the HAT modules of ATAC or SAGA complexes. Our results thus demonstrate that the catalytic activity of GCN5 is stimulated by subunits of the ADA2a- or ADA2b-containing HAT modules and is further increased by incorporation of the distinct HAT modules in the ATAC or SAGA holo-complexes
Rhea—a manually curated resource of biochemical reactions
Rhea (http://www.ebi.ac.uk/rhea) is a comprehensive resource of expert-curated biochemical reactions. Rhea provides a non-redundant set of chemical transformations for use in a broad spectrum of applications, including metabolic network reconstruction and pathway inference. Rhea includes enzyme-catalyzed reactions (covering the IUBMB Enzyme Nomenclature list), transport reactions and spontaneously occurring reactions. Rhea reactions are described using chemical species from the Chemical Entities of Biological Interest ontology (ChEBI) and are stoichiometrically balanced for mass and charge. They are extensively manually curated with links to source literature and other public resources on metabolism including enzyme and pathway databases. This cross-referencing facilitates the mapping and reconciliation of common reactions and compounds between distinct resources, which is a common first step in the reconstruction of genome scale metabolic networks and models
De novo variants in ATXN7L3 lead to developmental delay, hypotonia and distinctive facial features
Deubiquitination is critical for the proper functioning of numerous biological pathways such as DNA repair, cell cycle progression, transcription, signal transduction, and autophagy. Accordingly, pathogenic variants in deubiquitinating enzymes (DUBs) have been implicated in neurodevelopmental disorders (ND) and congenital abnormalities. ATXN7L3 is a component of the DUB module of the SAGA complex, and two other related DUB modules, and serves as an obligate adaptor protein of 3 ubiquitin-specific proteases (USP22, USP27X or USP51).
Through exome sequencing and GeneMatching, we identified nine individuals with heterozygous variants in ATXN7L3. The core phenotype included global motor and language developmental delay, hypotonia, and distinctive facial characteristics including hypertelorism, epicanthal folds, blepharoptosis, a small nose and mouth, and low-set posteriorly rotated ears.
In order to assess pathogenicity, we investigated the effects of a recurrent nonsense variant [c.340C>T; p.(Arg114Ter)] in fibroblasts of an affected individual. ATXN7L3 protein levels were reduced, and deubiquitylation was impaired, as indicated by an increase in histone H2Bub1 levels.
This is consistent with the previous observation of increased H2Bub1 levels in Atxn7l3-null mouse embryos, which have developmental delay and embryonic lethality. In conclusion, we present clinical information and biochemical characterization supporting ATXN7L3 variants in the pathogenesis of a rare syndromic ND
Chaperonin CCT Checkpoint Function in Basal Transcription Factor TFIID Assembly
International audienc
Identification of a Small TAF Complex and Its Role in the Assembly of TAF-Containing Complexes
TFIID plays a role in nucleating RNA polymerase II preinitiation complex assembly on protein-coding genes. TFIID is a multisubunit complex comprised of the TATA box binding protein (TBP) and 14 TBP-associated factors (TAFs). Another class of multiprotein transcriptional regulatory complexes having histone acetyl transferase (HAT) activity, and containing TAFs, includes TFTC, STAGA and the PCAF/GCN5 complex. Looking for as yet undiscovered subunits by a proteomic approach, we had identified TAF8 and SPT7L in human TFTC preparations. Subsequently, however, we demonstrated that TAF8 was not a stable component of TFTC, but that it is present in a small TAF complex (SMAT), containing TAF8, TAF10 and SPT7L, that co-purified with TFTC. Thus, TAF8 is a subunit of both TFIID and SMAT. The latter has to be involved in a pathway of complex formation distinct from the other known TAF complexes, since these three histone fold (HF)-containing proteins (TAF8, TAF10 and SPT7L) can never be found together either in TFIID or in STAGA/TFTC HAT complexes. Here we show that TAF8 is absolutely necessary for the integration of TAF10 in a higher order TFIID core complex containing seven TAFs. TAF8 forms a heterodimer with TAF10 through its HF and proline rich domains, and also interacts with SPT7L through its C-terminal region, and the three proteins form a complex in vitro and in vivo. Thus, the TAF8-TAF10 and TAF10-SPT7L HF pairs, and also the SMAT complex, seem to be important regulators of the composition of different TFIID and/or STAGA/TFTC complexes in the nucleus and consequently may play a role in gene regulation
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