Human high-density lipoprotein particles prevent activation of the JNK pathway induced by human oxidised low-density lipoprotein particles in pancreatic beta cells

Aims/hypothesis: We explored the potential adverse effects of pro-atherogenic oxidised LDL-cholesterol particles on beta cell function. Materials and methods: Isolated human and rat islets and different insulin-secreting cell lines were incubated with human oxidised LDL with or without HDL particles. The insulin level was monitored by ELISA, real-time PCR and a rat insulin promoter construct linked to luciferase gene reporter. Cell apoptosis was determined by scoring cells displaying pycnotic nuclei. Results: Prolonged incubation with human oxidised LDL particles led to a reduction in preproinsulin expression levels, whereas the insulin level was preserved in the presence of native LDL-cholesterol. The loss of insulin production occurred at the transcriptional levels and was associated with an increase in activator protein-1 transcriptional activity. The rise in activator protein-1 activity resulted from activation of c-Jun N-terminal kinases (JNK, now known as mitogen-activated protein kinase 8 [MAPK8]) due to a subsequent decrease in islet-brain 1 (IB1; now known as MAPK8 interacting protein 1) levels. Consistent with the pro-apoptotic role of the JNK pathway, oxidised LDL also induced a twofold increase in the rate of beta cell apoptosis. Treatment of the cells with JNK inhibitor peptides or HDL countered the effects mediated by oxidised LDL. Conclusions/interpretation: These data provide strong evidence that oxidised LDL particles exert deleterious effects in the progression of beta cell failure in diabetes and that these effects can be countered by HDL particle

Role for inducible cAMP early repressor in promoting pancreatic beta cell dysfunction evoked by oxidative stress in human and rat islets

Aims/hypothesis: Pro-atherogenic and pro-oxidant, oxidised LDL trigger adverse effects on pancreatic beta cells, possibly contributing to diabetes progression. Because oxidised LDL diminish the expression of genes regulated by the inducible cAMP early repressor (ICER), we investigated the involvement of this transcription factor and of oxidative stress in beta cell failure elicited by oxidised LDL. Methods: Isolated human and rat islets, and insulin-secreting cells were cultured with human native or oxidised LDL or with hydrogen peroxide. The expression of genes was determined by quantitative real-time PCR and western blotting. Insulin secretion was monitored by EIA kit. Cell apoptosis was determined by scoring cells displaying pycnotic nuclei. Results: Exposure of beta cell lines and islets to oxidised LDL, but not to native LDL raised the abundance of ICER. Induction of this repressor by the modified LDL compromised the expression of important beta cell genes, including insulin and anti-apoptotic islet brain 1, as well as of genes coding for key components of the secretory machinery. This led to hampering of insulin production and secretion, and of cell survival. Silencing of this transcription factor by RNA interference restored the expression of its target genes and alleviated beta cell dysfunction and death triggered by oxidised LDL. Induction of ICER was stimulated by oxidative stress, whereas antioxidant treatment with N-acetylcysteine or HDL prevented the rise of ICER elicited by oxidised LDL and restored beta cell functions. Conclusions/interpretation: Induction of ICER links oxidative stress to beta cell failure caused by oxidised LDL and can be effectively abrogated by antioxidant treatmen

Flexographic printing of ultra-thin semiconductor polymer layers

Methods of fabricating and controlling organic light emitting diode (OLED) or photovoltaic layers effectively are paramount for achieving a functional and durable device. The deposited film needs to be uniform and homogeneous to avoid non-uniform luminescence in the OLED. Although methods of depositing the ultra-thin sub 100 nm layers within OLED are effective, they are relatively slow and expensive. This paper therefore demonstrates flexography as an alternative method for depositing the semiconductor layer for OLED onto glass substrate. In this case a proprietary semiconducting polyflourine dispersed in xylene was used. This material functions as the hole injecting layer. The low polymer concentration and requirement for aromatic solvent presented challenges for the process; conventional photopolymer printing plates degraded rapidly on contact with xylene and rubber printing plates were found to be sufficiently resilient. Through optimisation of printing parameters and surface modification of both the printing plate and substrate with UV/ozone exposure, a consistent sub-100 nm film was achieved. Flexographic printing will enable a substantial reduction in layer fabrication time, as well as allowing roll to roll mass production at lower cost. The research indicated within this paper will aid the progression of flexography as a viable cost effective method for OLED or display technology application through continuous printing of ultra-thin layers

Role for inducible cAMP early repressor in promoting pancreatic beta cell dysfunction evoked by oxidative stress in human and rat islets

AIMS/HYPOTHESIS: Pro-atherogenic and pro-oxidant, oxidised LDL trigger adverse effects on pancreatic beta cells, possibly contributing to diabetes progression. Because oxidised LDL diminish the expression of genes regulated by the inducible cAMP early repressor (ICER), we investigated the involvement of this transcription factor and of oxidative stress in beta cell failure elicited by oxidised LDL. METHODS: Isolated human and rat islets, and insulin-secreting cells were cultured with human native or oxidised LDL or with hydrogen peroxide. The expression of genes was determined by quantitative real-time PCR and western blotting. Insulin secretion was monitored by EIA kit. Cell apoptosis was determined by scoring cells displaying pycnotic nuclei. RESULTS: Exposure of beta cell lines and islets to oxidised LDL, but not to native LDL raised the abundance of ICER. Induction of this repressor by the modified LDL compromised the expression of important beta cell genes, including insulin and anti-apoptotic islet brain 1, as well as of genes coding for key components of the secretory machinery. This led to hampering of insulin production and secretion, and of cell survival. Silencing of this transcription factor by RNA interference restored the expression of its target genes and alleviated beta cell dysfunction and death triggered by oxidised LDL. Induction of ICER was stimulated by oxidative stress, whereas antioxidant treatment with N-acetylcysteine or HDL prevented the rise of ICER elicited by oxidised LDL and restored beta cell functions. CONCLUSIONS/INTERPRETATION: Induction of ICER links oxidative stress to beta cell failure caused by oxidised LDL and can be effectively abrogated by antioxidant treatment

Decreasing Proportion of Recent Infections among Newly Diagnosed HIV-1 Cases in Switzerland, 2008 to 2013 Based on Line-Immunoassay-Based Algorithms.

BACKGROUND: HIV surveillance requires monitoring of new HIV diagnoses and differentiation of incident and older infections. In 2008, Switzerland implemented a system for monitoring incident HIV infections based on the results of a line immunoassay (Inno-Lia) mandatorily conducted for HIV confirmation and type differentiation (HIV-1, HIV-2) of all newly diagnosed patients. Based on this system, we assessed the proportion of incident HIV infection among newly diagnosed cases in Switzerland during 2008-2013. METHODS AND RESULTS: Inno-Lia antibody reaction patterns recorded in anonymous HIV notifications to the federal health authority were classified by 10 published algorithms into incident (up to 12 months) or older infections. Utilizing these data, annual incident infection estimates were obtained in two ways, (i) based on the diagnostic performance of the algorithms and utilizing the relationship 'incident = true incident + false incident', (ii) based on the window-periods of the algorithms and utilizing the relationship 'Prevalence = Incidence x Duration'. From 2008-2013, 3'851 HIV notifications were received. Adult HIV-1 infections amounted to 3'809 cases, and 3'636 of them (95.5%) contained Inno-Lia data. Incident infection totals calculated were similar for the performance- and window-based methods, amounting on average to 1'755 (95% confidence interval, 1588-1923) and 1'790 cases (95% CI, 1679-1900), respectively. More than half of these were among men who had sex with men. Both methods showed a continuous decline of annual incident infections 2008-2013, totaling -59.5% and -50.2%, respectively. The decline of incident infections continued even in 2012, when a 15% increase in HIV notifications had been observed. This increase was entirely due to older infections. Overall declines 2008-2013 were of similar extent among the major transmission groups. CONCLUSIONS: Inno-Lia based incident HIV-1 infection surveillance proved useful and reliable. It represents a free, additional public health benefit of the use of this relatively costly test for HIV confirmation and type differentiation

Generation of a Recombinant Gag Virus-Like-Particle Panel for the Evaluation of p24 Antigen Detection by Diagnostic HIV Tests.

BACKGROUND: Detection of HIV-1 p24 antigen permits early identification of primary HIV infection and timely intervention to limit further spread of the infection. Principally, HIV screening should equally detect all viral variants, but reagents for a standardised test evaluation are limited. Therefore, we aimed to create an inexhaustible panel of diverse HIV-1 p24 antigens. METHODS: We generated a panel of 43 recombinantly expressed virus-like particles (VLPs), containing the structural Gag proteins of HIV-1 subtypes A-H and circulating recombinant forms (CRF) CRF01_AE, CRF02_AG, CRF12_BF, CRF20_BG and group O. Eleven 4th generation antigen/antibody tests and five antigen-only tests were evaluated for their ability to detect VLPs diluted in human plasma to p24 concentrations equivalent to 50, 10 and 2 IU/ml of the WHO p24 standard. Three tests were also evaluated for their ability to detect p24 after heat-denaturation for immune-complex disruption, a pre-requisite for ultrasensitive p24 detection. RESULTS: Our VLP panel exhibited an average intra-clade p24 diversity of 6.7%. Among the 4th generation tests, the Abbott Architect and Siemens Enzygnost Integral 4 had the highest sensitivity of 97.7% and 93%, respectively. Alere Determine Combo and BioRad Access were least sensitive with 10.1% and 40.3%, respectively. Antigen-only tests were slightly more sensitive than combination tests. Almost all tests detected the WHO HIV-1 p24 standard at a concentration of 2 IU/ml, but their ability to detect this input for different subtypes varied greatly. Heat-treatment lowered overall detectability of HIV-1 p24 in two of the three tests, but only few VLPs had a more than 3-fold loss in p24 detection. CONCLUSIONS: The HIV-1 Gag subtype panel has a broad diversity and proved useful for a standardised evaluation of the detection limit and breadth of subtype detection of p24 antigen-detecting tests. Several tests exhibited problems, particularly with non-B subtypes

Evaluation study of the suitability of instrumentation to measure ambient NH3 concentrations under field conditions

The uncertainties in emissions of ammonia (NH3) in Europe are large, partially due to the difficulty in monitoring of ambient concentrations due to its sticky nature. In the European Monitoring and Evaluation Program (EMEP) the current recommended guidelines to measure NH3 are by coated annular denuders with offline analysis. This method, however, is no longer used in most European countries and each one has taken a different strategy to monitor atmospheric ammonia due to the increase of commercial NH3 monitoring instrumentation available over the last 20 years. In June 2014, a 3 year project funded under the European Metrology Research Programme, “Metrology for Ammonia in Ambient Air” (MetNH3), started with the aim to develop metrological traceability for the measurement of NH3 in air from primary gas mixtures and instrumental standards to field application. This study presents the results from the field intercomparison (15 instruments) which was held in South East Scotland in August 2016 over an intensively managed grassland. The study compared active sampling methods to a meteorological traceable method which was developed during the project with the aim to produce a series of guidelines for ambient NH3 measurements. Preliminary results highlight both the importance of inlets and management of relative humidity in the measurement of ambient NH3 and of the requirement to carry out frequent intercomparison of NH3 instrumentation. Overall, it would be recommended from this study that a WMO-GAW world centre for NH3 would be established and support integration of standards into both routine and research measurements

Tracing digital transformation in educational organizations

This chapter describes the quantitative approaches for assessing various aspects of digital transformation from the joint research and development project #ko.vernetzt. In an application-oriented case study approach, the operationalization of a maturity model of digital transformation for educational organizations (MMEO) and the design and implementation of a multi-perspective evaluation concept are outlined. While the MMEO provides a state perspective on the digital transformation of an educational organization and its employees, the evaluation concept aims at tracing developments of media-related professional competencies. MMEO has been implemented in a study with N = 222 participants, while N = 59 learners were subject to the evaluation polls. The results provide the necessary evidence for implementing and continuously improving a qualification program in the regarded research context. However, the methodology can also be transferred to other organizations in the education sector and beyond