Contrast-enhanced nano-CT reveals soft dental tissues and cellular layers

Aim: To introduce a methodology designed to simultaneously visualize dental ultrastructures, including cellular and soft tissue components, by utilizing phosphotungstic acid (PTA) as a contrast-enhancement agent. Methodology: Sound third molars were collected from healthy human adults and fixed in 4% buffered paraformaldehyde. To evaluate the impact of PTA in concentrations of 0.3%, 0.7% and 1% on dental soft and hard tissues for CT imaging, cementum and dentine-pulp sections were cut, dehydrated and stained with immersion periods of 12, 24 h, 2 days or 5 days. The samples were scanned in a high-resolution nano-CT device using pixel sizes down to 0.5 µm to examine both the cementum and pulpal regions. Results: Dental cementum and periodontium as well as odontoblasts and predentine were made visible through PTA staining in high-resolution three-dimensional nano-CT scans. Different segments of the tooth required different staining protocols. The thickness of the cementum could be computed over the length of the tooth once it was made visible by the PTA-enhanced contrast, and the attached soft tissue components of the interior of the tooth could be shown on the dentine-pulp interface in greater detail. Three-dimensional illustrations allowed a histology-like visualization of the sections in all orientations with a single scan and easy sample preparation. The segmentation of the sigmoidal dentinal tubules and the surrounding dentine allowed a three-dimensional investigation and quantitative of the dentine composition, such as the tubular lumen or the ratio of the tubular lumen area to the dentinal surface. Conclusion: The staining protocol made it possible to visualize hard tissues along with cellular layers and soft tissues in teeth using a laboratory-based nano-CT technique. The protocol depended on both tissue type and size. This methodology offers enhanced possibilities for the concomitant visualization of soft and hard dental tissues. © 2021 The Authors. International Endodontic Journal published by John Wiley & Sons Ltd on behalf of British Endodontic Societ

Heterologously-expressed and Liposome-reconstituted Human Transient Receptor Potential Melastatin 4 Channel (TRPM4) is a Functional Tetramer

Mutation, irregular expression and sustained activation of the Transient Receptor Potential Channel, type Melastatin 4 (TRPM4), have been linked to various cardiovascular diseases. However, much remains unknown about the structure of this important ion channel. Here, we have purified a heterologously expressed TRPM4-eGFP fusion protein and investigated the oligomeric state of TRPM4-eGFP in detergent micelles using crosslinking, native gel electrophoresis, multi-angle laser light scattering and electron microscopy. Our data indicate that TRPM4 is tetrameric, like other TRP channels studied to date. Furthermore, the functionality of liposome reconstituted TRPM4-eGFP was examined using electrophysiology. Single-channel recordings from TRPM4-eGFP proteoliposomes showed inhibition of the channel using Flufenamic acid, a well-established inhibitor of TRPM4, suggesting that the channels are functional upon reconstitution. Our characterisation of the oligomeric structure of TRPM4 and the ability to reconstitute functional channels in liposomes should facilitate future studies into the structure, function and pharmacology of this therapeutically relevant channel

Digestibility in selected rainbow trout families and modelling of growth from the specific intake of digestible protein

The experiments aimed to clarify variations in digestibility of dietary nutrients in rainbow trout. Furthermore, the objective was to study how differences in digestibility might be related to growth and feed utilisation at various growth rates. When comparing the results from the experiments it appeared that particularly protein digestibility was closely related to specific growth rate and feed conversion ratio at high growth rates. As a tool to visualise the relationship between protein digestibility and growth of rainbow trout a growth model was developed based on the specific intake of digestible protein, and general assumptions on protein content and protein retention efficiency in rainbow trout. The model indicated that increased protein digestibility only partly explained growth increase and that additional factors were important for growth increment

Adult advanced life support: Section 3 of the European Resuscitation Council Guidelines for Resuscitation 2015

Erweiterte lebensrettende Maßnahmen für Erwachsene („advanced life support“, ALS) kommen zum Einsatz, nachdem Basismaßnahmen zur Wiederbelebung („basic life support“, BLS) begonnen und, wenn sinnvoll, ein automatisierter externer Defibrillator (AED) verwendet wurde. Die Basismaßnahmen zur Wiederbelebung eines Erwachsenen und der Einsatz von AEDs wird in Kap. 2 ausgeführt. Basis- und erweiterte Maßnahmen sollen nahtlos ineinander übergehen, da erstere fortgeführt werden und sich mit den erweiterten überschneiden. Dieses Kapitel über die erweiterten Maßnahmen beinhaltet die Vermeidung des Kreislaufstillstands, spezielle Aspekte des außerklinischen ALS, den Start der innerklinischen Reanimation, den ALS-Algorithmus, die manuelle Defibrillation, das Atemwegsmanagement während der Reanimaton, Medikamente und ihre Anwendung während der Reanimation sowie die Behandlung von Periarrest-Arrhythmien. Es gibt zwei Änderungen in der äußeren Form dieser Leitlinien des Europäischen Rats für Wiederbelebung seit den Leitlinien von 2010: [1] Das Kapitel „Elektrotherapie“ [2] ist nicht mehr eigenständig, sondern Teil dieses Kapitels; und die Leitlinien zur Behandlung nach Reanimation sind in ein neues Kapitel ausgegliedert, welches die Bedeutung dieses letzten Glieds der Überlebenskette unterstreicht [3]. Diese Leitlinien basieren auf den International Liaison Committee on Resuscitation (ILCOR) Consensus on Science and Treatment Recommendations (CoSTR) für ALS von 2015 [4]. Die Überprüfung der ILCOR-Empfehlungen von 2015 konzentrierte sich auf 42 Themen, entsprechend der zeitlichen Abfolge der erweiterten Maßnahmen: Defibrillation, Atemwege, Oxygenierung und Ventilation, Kreislaufunterstützung und Überwachung und Einsatz von Medikamenten während der Reanimation. Für diese Leitlinien wurden die ILCOR-Empfehlungen durch ein gezieltes Literatur-Review ergänzt, welches von der ERC-ALS-Leitlinien Autorengruppe zu den Themen die nicht in den ILCOR-CoSTR-Empfehlungen von 2015 überarbeitet wurden erstellt wurde. Die Leitlinien wurden ausgearbeitet, von den ALS-Verfassern geprüft und abschließend von der ERC-Vollversammlung und dem ERC-Vorstand abgesegnet

The present and future of cardiac arrest care : international experts reach out to caregivers and healthcare authorities

The purpose of this review is to describe the epidemiology of out-of-hospital cardiac arrest (OHCA), disparities in organisation and outcome, recent advances in treatment and ongoing controversies. We also outline the standard of care that should be provided by the critical care specialist and propose future directions for cardiac arrest research. Narrative review with contributions from international resuscitation experts. Although it is recognised that survival rates from OHCA are increasing there is considerable scope for improvement and many countries have implemented national strategies in an attempt to achieve this goal. More resources are required to enable high-quality randomised trials in resuscitation. Increasing international collaboration should facilitate resuscitation research and knowledge translation. The International Liaison Committee on Resuscitation (ILCOR) has adopted a continuous evidence review process, which facilitate the implementation of resuscitation interventions proven to improve patient outcomes.Peer reviewe

Discrete molecular dynamics simulations of peptide aggregation

We study the aggregation of peptides using the discrete molecular dynamics simulations. At temperatures above the alpha-helix melting temperature of a single peptide, the model peptides aggregate into a multi-layer parallel beta-sheet structure. This structure has an inter-strand distance of 0.48 nm and an inter-sheet distance of 1.0 nm, which agree with experimental observations. In this model, the hydrogen bond interactions give rise to the inter-strand spacing in beta-sheets, while the Go interactions among side chains make beta-strands parallel to each other and allow beta-sheets to pack into layers. The aggregates also contain free edges which may allow for further aggregation of model peptides to form elongated fibrils.Comment: 15 pages, 8 figure

Influence of circulatory shock at hospital admission on outcome after out-of-hospital cardiac arrest

Hypotension after cardiac arrest could aggravate prolonged hypoxic ischemic encephalopathy. The association of circulatory shock at hospital admission with outcome after cardiac arrest has not been well studied. The objective of this study was to investigate the independent association of circulatory shock at hospital admission with neurologic outcome, and to evaluate whether cardiovascular comorbidities interact with circulatory shock. 4004 adult patients with out-of-hospital cardiac arrest enrolled in the International Cardiac Arrest Registry 2006–2017 were included in analysis. Circulatory shock was defined as a systolic blood pressure below 90 mmHg and/or medical or mechanical supportive measures to maintain adequate perfusion during hospital admission. Primary outcome was cerebral performance category (CPC) dichotomized as good, (CPC 1–2) versus poor (CPC 3–5) outcome at hospital discharge. 38% of included patients were in circulatory shock at hospital admission, 32% had good neurologic outcome at hospital discharge. The adjusted odds ratio for good neurologic outcome in patients without preexisting cardiovascular disease with circulatory shock at hospital admission was 0.60 [0.46–0.79]. No significant interaction was detected with preexisting comorbidities in the main analysis. We conclude that circulatory shock at hospital admission after out-of-hospital cardiac arrest is independently associated with poor neurologic outcome.publishedVersio

Prediction of peptide and protein propensity for amyloid formation

Understanding which peptides and proteins have the potential to undergo amyloid formation and what driving forces are responsible for amyloid-like fiber formation and stabilization remains limited. This is mainly because proteins that can undergo structural changes, which lead to amyloid formation, are quite diverse and share no obvious sequence or structural homology, despite the structural similarity found in the fibrils. To address these issues, a novel approach based on recursive feature selection and feed-forward neural networks was undertaken to identify key features highly correlated with the self-assembly problem. This approach allowed the identification of seven physicochemical and biochemical properties of the amino acids highly associated with the self-assembly of peptides and proteins into amyloid-like fibrils (normalized frequency of β-sheet, normalized frequency of β-sheet from LG, weights for β-sheet at the window position of 1, isoelectric point, atom-based hydrophobic moment, helix termination parameter at position j+1 and ΔGº values for peptides extrapolated in 0 M urea). Moreover, these features enabled the development of a new predictor (available at http://cran.r-project.org/web/packages/appnn/index.html) capable of accurately and reliably predicting the amyloidogenic propensity from the polypeptide sequence alone with a prediction accuracy of 84.9 % against an external validation dataset of sequences with experimental in vitro, evidence of amyloid formation