HiGHmed - An Open Platform Approach to Enhance Care and Research across Institutional Boundaries.

INTRODUCTION: This article is part of the Focus Theme of Methods of Information in Medicine on the German Medical Informatics Initiative. HiGHmed brings together 24 partners from academia and industry, aiming at improvements in care provision, biomedical research and epidemiology. By establishing a shared information governance framework, data integration centers and an open platform architecture in cooperation with independent healthcare providers, the meaningful reuse of data will be facilitated. Complementary, HiGHmed integrates a total of seven Medical Informatics curricula to develop collaborative structures and processes to train medical informatics professionals, physicians and researchers in new forms of data analytics. GOVERNANCE AND POLICIES: We describe governance structures and policies that have proven effective during the conceptual phase. These were further adapted to take into account the specific needs of the development and networking phase, such as roll-out, carerelated aspects and our focus on curricula development in Medical Inform atics. ARCHITECTURAL FRAMEWORK AND METHODOLOGY: To address the challenges of organizational, technical and semantic interoperability, a concept for a scalable platform architecture, the HiGHmed Platform, was developed. We outline the basic principles and design goals of the open platform approach as well as the roles of standards and specifications such as IHE XDS, openEHR, SNOMED CT and HL7 FHIR. A shared governance framework provides the semantic artifacts which are needed to establish semantic interoperability. USE CASES: Three use cases in the fields of oncology, cardiology and infection control will demonstrate the capabilities of the HiGHmed approach. Each of the use cases entails diverse challenges in terms of data protection, privacy and security, including clinical use of genome sequencing data (oncology), continuous longitudinal monitoring of physical activity (cardiology) and cross-site analysis of patient movement data (infection control). DISCUSSION: Besides the need for a shared governance framework and a technical infrastructure, backing from clinical leaders is a crucial factor. Moreover, firm and sustainable commitment by participating organizations to collaborate in further development of their information system architectures is needed. Other challenges including topics such as data quality, privacy regulations, and patient consent will be addressed throughout the project.

N-truncated Aß4-x peptides in sporadic Alzheimer's disease cases and transgenic Alzheimer mouse models.

BACKGROUND: The deposition of neurotoxic amyloid-ß (Aß) peptides in plaques in the brain parenchyma and in cerebral blood vessels is considered to be a key event in Alzheimer's disease (AD) pathogenesis. Although the presence and impact of full-length Aß peptides such as Aß1-40 and Aß1-42 have been analyzed extensively, the deposition of N-terminally truncated Aß peptide species has received much less attention, largely because of the lack of specific antibodies. METHODS: This paper describes the generation and characterization of novel antibodies selective for Aß4-x peptides and provides immunohistochemical evidence of Aß4-x in the human brain and its distribution in the APP/PS1KI and 5XFAD transgenic mouse models. RESULTS: The Aß4-x staining pattern was restricted mainly to amyloid plaque cores and cerebral amyloid angiopathy in AD and Down syndrome cases and in both AD mouse models. In contrast, diffuse amyloid deposits were largely negative for Aß4-x immunoreactivity. No overt intraneuronal staining was observed. CONCLUSIONS: The findings of this study are consistent with previous reports demonstrating a high aggregation propensity of Aß4-x peptides and suggest an important role of these N-truncated Aß species in the process of amyloidogenesis and plaque core formation.

Validation of a Commercial Chemiluminescence Immunoassay for the Simultaneous Measurement of Three Different Amyloid-ß Peptides in Human Cerebrospinal Fluid and Application to a Clinical Cohort.

A comprehensive assay validation campaign of a commercially available chemiluminescence multiplex immunoassay for the simultaneous measurement of the amyloid-ß peptides Aß38, Aß40, and Aß42 in human cerebrospinal fluid (CSF) is presented. The assay quality parameters we addressed included impact of sample dilution, parallelism, lower limits of detection, lower limits of quantification, intra- and inter-assay repeatability, analytical spike recoveries, and between laboratory reproducibility of the measurements. The assay performed well in our hands and fulfilled a number of predefined acceptance criteria. The CSF levels of Aß40 and Aß42 determined in a clinical cohort (n = 203) were statistically significantly correlated with available ELISA data of Aß1-40 (n = 158) and Aß1-42 (n = 179) from a different laboratory. However, Bland-Altman method comparison indicated systematic differences between the assays. The data presented here furthermore indicate that the CSF concentration of Aß40 can surrogate total CSF Aß and support the hypothesis that the Aß42/Aß40 ratio outperforms CSF Aß42 alone as a biomarker for Alzheimer's disease due to a normalization to total Aß levels.

Detection and Differentiation of Threonine- and Tyrosine-Monophosphorylated Forms of ERK1/2 by Capillary Isoelectric Focusing-Immunoassay.

The extracellular signal regulated kinases ERK1/2 play important roles in the regulation of diverse cellular functions and have been implicated in several human diseases. In addition to the fully activated, diphosphorylated ERK1/2 protein, monophosphorylated forms of ERK1/2 have been observed, which may have distinct biological functions. We report here on the highly sensitive detection and differentiation of unphosphorylated, threonine-phosphorylated (pT), tyrosine-phosphorylated (pY) and diphosphorylated ERK1 and ERK2 by capillary isoelectric focusing followed by immunological detection (CIEF-immunoassay). Eight different phosphorylated and unphosphorylated forms of ERK1/2 were resolved according to charge. The unequivocal identification and differentiation of ERK1 and ERK2 forms monophosphorylated at either threonine or tyrosine was achieved by competitive blocking with specific phospho-peptides and different phosphorylation-sensitive antibodies. The suitability of the additional pT-ERK1/2 and pY-ERK1/2 differentiation for the time-resolved in-depth study of phospho-form distribution in response to specific stimuli is demonstrated in human neuroblastoma SH-SY5Y and monocytic THP-1 cell lines, and in human peripheral blood mononuclear cells.

Membrane region M2C2 in subunit KtrB of the K+ uptake system KtrAB from Vibrio alginolyticus forms a flexible gate controlling K+ flux: an electron paramagnetic resonance study.

Transmembrane stretch M(2C) from the bacterial K(+)-translocating protein KtrB is unusually long. In its middle part, termed M(2C2), it contains several small and polar amino acids. This region is flanked by the two alpha-helices M(2C1) and M(2C3) and may form a flexible gate at the cytoplasmic side of the membrane controlling K(+) translocation. In this study, we provide experimental evidence for this notion by using continuous wave and pulse EPR measurements of single and double spin-labeled cysteine variants of KtrB. Most of the spin-labeled residues in M(2C2) were shown to be immobile, pointing to a compact structure. However, the high polarity revealed for the microenvironment of residue positions 317, 318, and 327 indicated the existence of a water-accessible cavity. Upon the addition of K(+) ions, M(2C2) residue Thr-318R1 (R1 indicates the bound spin label) moved with respect to M(2B) residue Asp-222R1 and M(2C3) residue Val-331R1 but not with respect to M(2C1) residue Met-311R1. Based on distances determined between spin-labeled residues of double-labeled variants of KtrB in the presence and absence of K(+) ions, structural models of the open and closed conformations were developed.