FRET compatible long-wavelength labels and their application in immunoassays and hybridization assays

Ziel der Arbeit war die Synthese neuer langwelliger Fluoreszenzfarbstoffe, ihre Kopplung an Biomoleküle und deren Verwendung in Assay

Examining student satisfaction with higher education services: using a new measurement tool

Purpose – This paper aims to investigate how students perceive the services they are offered at a German university and how satisfied they are with them. Design/methodology/approach – An evaluation study using a new tool to measure 15 dimensions of student satisfaction at an institutional level that covers most aspects of student life was used. It was decided to develop a new measurement tool as many existing surveys are poorly designed, lack standardization and give no evidence concerning reliability or validity. Questionnaires were handed out in eight lectures for the pilot study and 18 lectures for the main study. The response rate was 99 percent. A total of 374 students (pilot study) and 544 students (main study) filled in the newly developed questionnaires using Likert scales. Findings – The study gave a valuable insight into how students perceive the quality of the services offered at a university and how satisfied they are with these offerings. The results show that students' satisfaction with their university is based on a relatively stable person-environment relationship. Thus, the satisfaction of students seems to reflect quite well perceived quality differences of offered services and of the wider environment. Students were particularly satisfied with the school placements and the atmosphere among students. Students were mostly dissatisfied with the university buildings and the quality of the lecture theatres. Research limitations/implications – As the study involved only two samples of students from one university, the results cannot be generalized to the German student population as a whole. Originality/value – The study was the first to successfully apply a measurement tool, which has previously not been used. The study has hopefully opened up an area of research and methodology that could provide considerable further benefits for researchers interested in this topic. It also shows how the concept of student satisfaction could be assessed in future studies

TSLP is a direct trigger for T cell migration in filaggrin-deficient skin equivalents

Mutations in the gene encoding for filaggrin (FLG) are major predisposing factors for atopic dermatitis (AD). Besides genetic predisposition, immunological dysregulations considerably contribute to its pathophysiology. For example, thymic stromal lymphopoietin (TSLP) is highly expressed in lesional atopic skin and significantly contributes to the pathogenesis of AD by activating dendritic cells that then initiate downstream effects on, for example, T cells. However, little is known about the direct interplay between TSLP, filaggrin-deficient skin and other immune cells such as T lymphocytes. In the present study, FLG knockdown skin equivalents, characterised by intrinsically high TSLP levels, were exposed to activated CD4+ T cells. T cell exposure resulted in an inflammatory phenotype of the skin equivalents. Furthermore, a distinct shift from a Th1/Th17 to a Th2/Th22 profile was observed following exposure of T cells to filaggrin-deficient skin equivalents. Interestingly, TSLP directly stimulated T cell migration exclusively in filaggrin-deficient skin equivalents even in the absence of dendritic cells, indicating a hitherto unknown role of TSLP in the pathogenesis of AD

The BRCT domain of mammalian Pes1 is crucial for nucleolar localization and rRNA processing

The nucleolar protein Pes1 interacts with Bop1 and WDR12 in a stable complex (PeBoW-complex) and its expression is tightly associated with cell proliferation. The yeast homologue Nop7p (Yph1p) functions in both, rRNA processing and cell cycle progression. The presence of a BRCT-domain (BRCA1 C-terminal) within Pes1 is quite unique for an rRNA processing factor, as this domain is normally found in factors involved in DNA-damage or repair pathways. Thus, the function of the BRCT-domain in Pes1 remains elusive. We established a conditional siRNA-based knock-down-knock-in system and analysed a panel of Pes1 truncation mutants for their functionality in ribosome synthesis in the absence of endogenous Pes1. Deletion of the BRCT-domain or single point mutations of highly conserved residues caused diffuse nucleoplasmic distribution and failure to replace endogenous Pes1 in rRNA processing. Further, the BRCT-mutants of Pes1 were less stable and not incorporated into the PeBoW-complex. Hence, the integrity of the BRCT-domain of Pes1 is crucial for nucleolar localization and its function in rRNA processing

Dominant-negative Pes1 mutants inhibit ribosomal RNA processing and cell proliferation via incorporation into the PeBoW-complex

The nucleolar PeBoW-complex, consisting of Pes1, Bop1 and WDR12, is essential for cell proliferation and processing of ribosomal RNA in mammalian cells. Here we have analysed the physical and functional interactions of Pes1 deletion mutants with the PeBoW-complex. Pes1 mutants M1 and M5, with N- and C-terminal truncations, respectively, displayed a dominant-negative phenotype. Both mutants showed nucleolar localization, blocked processing of the 36S/32S precursors to mature 28S rRNA, inhibited cell proliferation, and induced high p53 levels in proliferating, but not in resting cells. Mutant M1 and M5 proteins associated with large pre-ribosomal complexes and co-immunoprecipitated Bop1 and WDR12 proteins indicating their proper incorporation into the PeBoW-complex. We conclude that the dominant-negative effect of the M1 and M5 mutants is mediated by the impaired function of the PeBoW-complex

Motor-Impedanzmessungen im aktiven Betriebszustand anhand einer permanentmagneterregten Synchronmaschine

Aufgrund ihres Schaltverhaltens können Wechselrichter (WR) hohe elektromagnetische Emissionen erzeugen. Zur Sicherstellung der elektromagnetischen Verträglichkeit (EMV) werden deshalb u.a. Emissionsmessungen durchgeführt. Bei Emissionsmessungen von Kfz-Wechselrichtern nach CISPR 25 [1] wird der zugehörige Motor als Peripherie betrachtet. Aus diesem Grund kann stattdessen eine möglichst realistische Ersatzlast verwendet werden. Häufig wird hierzu eine passive Impedanznachbildung eingesetzt, welche zwar eine gute Reproduzierbarkeit gewährleistet, allerdings nicht den realen Lastbedingungen entspricht. Für möglichst reale Lastbedingungen bieten einige wenige EMV-Labore Emissionsmessungen mit einer externen Last am Motor (hydraulisch oder mithilfe einer zusätzlichen Lastmaschine) an. Nachteilig sind hierbei u.a. die erhöhten Sicherheitsanforderungen aufgrund rotierender Teile sowie hohe Anschaffungs- und Prüfkosten. Vor diesem Hintergrund entstand die Idee, eine aktive elektrische Ersatzlast zu verwenden. Die aktive Impedanznachbildung soll sowohl das niederfrequente Funktionsverhalten als auch die hochfrequenten (HF) Koppelpfade einer belasteten elektrischen Maschine emulieren können. Für funktionale Prüfungen von Wechselrichtern werden bereits Systeme angeboten, welche das funktionale Verhalten abbilden und als elektrische Maschinenemulatoren bezeichnet werden (u.a. [2]). Bild 1 zeigt den zu prüfenden Wechselrichter (DUT, engl. device under test) sowie den über ein Koppelnetzwerk angeschlossenen Emulator. Um die Maschinenemulation auch bei EMV-Prüfungen verwenden zu können, muss diese die HF-Impedanz der belasteten Maschine ausreichend genau nachbilden, bei vernachlässigbar geringen Eigenemissionen. Eine genauere Ausführung zu diesem Ansatz und den Anforderungen sowie erste Messergebnisse werden in [3] präsentiert. Ziel dieses Papers ist die Untersuchung der Impedanzen für Gleichtakt (CM) und Gegentakt (DM) von elektrischen Maschinen im aktiven Betrieb. Die Ergebnisse sollen anschließend zur Nachbildung des HF-Verhaltens bei der elektrischen Maschinenemulation verwendet werden. Zunächst wird die verwendete Messmethode vorgestellt und validiert. Dann werden beispielhaft die CM- und DM-Impedanzen einer permanentmagneterregten Synchronmaschine (PMSM) bei verschiedenen Betriebsmodi analysiert. Abschließend werden Verhaltensmodelle zur Nachbildung der Motorimpedanz erstellt und die Werte der Streuparameter aus den Messkurven extrahiert

The Determination of Immunomodulation and Its Impact on Survival of Rectal Cancer Patients Depends on the Area Comprising a Tissue Microarray.

BACKGROUND: T cell density in colorectal cancer (CRC) has proven to be of high prognostic importance. Here, we evaluated the influence of a hyperfractionated preoperative short-term radiation protocol (25 Gy) on immune cell density in tumor samples of rectal cancer (RC) patients and on patient survival. In addition, we assessed spatial tumor heterogeneity by comparison of analogue T cell quantification on full tissue sections with digital T cell quantification on a virtually established tissue microarray (TMA). METHODS: A total of 75 RC patients (60 irradiated, 15 treatment-naïve) were defined for retrospective analysis. RC samples were processed for immunohistochemistry (CD3, CD8, PD-1, PD-L1). Analogue (score 0-3) as well as digital quantification (TMA: 2 cores vs. 6 cores, mean T cell count) of marker expression in 2 areas (central tumor, CT; invasive margin, IM) was performed. Survival was estimated on the basis of analogue as well as digital marker densities calculated from 2 cores (Immunoscore: CD3/CD8 ratio) and 6 cores per tumor area. RESULTS: Irradiated RC samples showed a significant decrease in CD3 and CD8 positive T cells, independent of quantification mode. T cell densities of 6 virtual cores approximated to T cell densities of full tissue sections, independent of individual core density or location. Survival analysis based on full tissue section quantification demonstrated that CD3 and CD8 positive T cells as well as PD-1 positive tumor infiltrating leucocytes (TILs) in the CT and the IM had a significant impact on disease-free survival (DFS) as well as overall survival (OS). In addition, CD3 and CD8 positive T cells as well as PD-1 positive TILs in the IM proved as independent prognostic factors for DFS and OS; in the CT, PD-1 positive TILs predicted DFS and CD3 and CD8 positive T cells as well as PD-1 positive TILs predicted OS. Survival analysis based on virtual TMA showed no impact on DFS or OS. CONCLUSION: Spatial tumor heterogeneity might result in inadequate quantification of immune marker expression; however, if using a TMA, 6 cores per tumor area and patient sample represent comparable amounts of T cell densities to those quantified on full tissue sections. Consistently, the tissue area used for immune marker quantification represents a crucial factor for the evaluation of prognostic and predictive biomarker potential

BNip3 regulates mitochondrial function and lipid metabolism in the liver

BNip3 localizes to the outer mitochondrial membrane, where it functions in mitophagy and mitochondrial dynamics. While the BNip3 protein is constitutively expressed in adult liver from fed mice, we have shown that its expression is superinduced by fasting of mice, consistent with a role in responses to nutrient deprivation. Loss of BNip3 resulted in increased lipid synthesis in the liver that was associated with elevated ATP levels, reduced AMP-regulated kinase (AMPK) activity, and increased expression of lipogenic enzymes. Conversely, there was reduced β-oxidation of fatty acids in BNip3 null liver and also defective glucose output under fasting conditions. These metabolic defects in BNip3 null liver were linked to increased mitochondrial mass and increased hepatocellular respiration in the presence of glucose. However, despite elevated mitochondrial mass, an increased proportion of mitochondria exhibited loss of mitochondrial membrane potential, abnormal structure, and reduced oxygen consumption. Elevated reactive oxygen species, inflammation, and features of steatohepatitis were also observed in the livers of BNip3 null mice. These results identify a role for BNip3 in limiting mitochondrial mass and maintaining mitochondrial integrity in the liver that has consequences for lipid metabolism and disease

Mammalian WDR12 is a novel member of the Pes1–Bop1 complex and is required for ribosome biogenesis and cell proliferation

Target genes of the protooncogene c-myc are implicated in cell cycle and growth control, yet the linkage of both is still unexplored. Here, we show that the products of the nucleolar target genes Pes1 and Bop1 form a stable complex with a novel member, WDR12 (PeBoW complex). Endogenous WDR12, a WD40 repeat protein, is crucial for processing of the 32S precursor ribosomal RNA (rRNA) and cell proliferation. Further, a conditionally expressed dominant-negative mutant of WDR12 also blocks rRNA processing and induces a reversible cell cycle arrest. Mutant WDR12 triggers accumulation of p53 in a p19ARF-independent manner in proliferating cells but not in quiescent cells. Interestingly, a potential homologous complex of Pes1–Bop1–WDR12 in yeast (Nop7p–Erb1p–Ytm1p) is involved in the control of ribosome biogenesis and S phase entry. In conclusion, the integrity of the PeBoW complex is required for ribosome biogenesis and cell proliferation in mammalian cells

Views and Experiences of Persons with Chronic Diseases about Strategies that Aim to Integrate and Re-Integrate Them into Work: A Systematic Review of Qualitative Studies

The effectiveness of strategies targeting professional integration and reintegration strongly depends on the experiences of participants. The aim of this systematic literature review is to synthesize European qualitative studies exploring views and experiences of persons with chronic conditions regarding strategies for integration and reintegration into work. The systematic search was conducted in Medline, PsycINFO, CDR-HTA, CDR-DARE and Cochrane Systematic Reviews. Overall, 24 studies published in English between January 2011 and April 2016 were included. Most studies were carried out in Nordic countries or in the UK, and most participants were persons with either mental or musculoskeletal disorders. Ten themes emerged: individual and holistic approach, clarity of strategy and processes, timing of rehabilitation processes, experience with professionals, at the workplace and with peer groups, changes in the understanding of health and work, active involvement in the process, competencies development and motivating aspects of work. Findings highlight, among others, the need to actively involve participants in the return to work process and to provide timely and clearly structured processes and interventions. This review provides stakeholders key information to develop, plan, implement and evaluate interventions to integrate and re-integrate persons with chronic conditions into work in Europe