A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Rapid establishment of the European Bank for induced Pluripotent Stem Cells (EBiSC):The Hot Start experience

A fast track “Hot Start” process was implemented to launch the European Bank for Induced Pluripotent Stem Cells (EBiSC) to provide early release of a range of established control and disease linked human induced pluripotent stem cell (hiPSC) lines. Established practice amongst consortium members was surveyed to arrive at harmonised and publically accessible Standard Operations Procedures (SOPs) for tissue procurement, bio-sample tracking, iPSC expansion, cryopreservation, qualification and distribution to the research community. These were implemented to create a quality managed foundational collection of lines and associated data made available for distribution. Here we report on the successful outcome of this experience and work flow for banking and facilitating access to an otherwise disparate European resource, with lessons to benefit the international research community. eTOC: The report focuses on the EBiSC experience of rapidly establishing an operational capacity to procure, bank and distribute a foundational collection of established hiPSC lines. It validates the feasibility and defines the challenges of harnessing and integrating the capability and productivity of centres across Europe using commonly available resources currently in the field

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

Model of maltose-binding protein/chemoreceptor complex supports intrasubunit signaling mechanism

The Tar protein of Escherichia coli is unique among known bacterial chemoreceptors in that it generates additive responses to two very disparate ligands, aspartate and maltose. Aspartate binds directly to the periplasmic (extracytoplasmic) domain of Tar. Maltose first binds to maltose-binding protein (MBP). MBP then assumes a closed conformation in which it can interact with the periplasmic domain of Tar. MBP residues critical for binding Tar were identified in a screen of mutations that cause specific defects in maltose chemotaxis. Mutations were introduced into a plasmid-borne malE gene that encodes a mutant form of MBP in which two engineered Cys residues spontaneously generate a disulfide bond in the oxidizing environment of the periplasmic space. This disulfide covalently crosslinks the NH(3)-terminal and COOH-terminal domains of MBP and locks the protein into a closed conformation. Double-Cys MBP confers a dominant-negative phenotype for maltose taxis, and we reasoned that third mutations that relieve this negative dominance probably alter residues that are important for the initial interaction of MBP with Tar. The published three-dimensional structures of MBP and the periplasmic domain of E. coli Tar were docked in a computer simulation that juxtaposed the residues in MBP identified in this way with residues in Tar that have been implicated in maltose taxis. The resulting model of the MBP-Tar complex exhibits good complementarity between the surfaces of the two proteins and supports the idea that aspartate and MBP may each initiate an attractant signal through Tar by inducing similar conformational changes in the chemoreceptor