Nebulised heparin: a new approach to the treatment of acute lung injury?

The administration of heparin by nebulisation has been proposed for the 'local' treatment of pulmonary coagulation disturbances in acute lung injury (ALI). Alveolar and lung micro-vascular fibrin accumulation and breakdown inhibition indeed play a central role in the development and clinical course of this disease. Preclinical studies provide some evidence of the beneficial effects of heparin inhalation in several animal models of ALI. Clinical investigations are sparse, and trials such as the one presented by Dixon and colleagues in a recent issue of Critical Care are welcome as they provide insight into the possible clinical use of nebulised heparin in this situation. This phase 1 trial involved 16 patients with early ALI, and showed the feasibility of the approach. In addition, non-significant changes in respiratory functions and systemic anticoagulant effects were documented with the four doses tested. The study of Dixon and colleagues adds to data that helps pave the way towards a possible clinical use of heparin by nebulisation in ALI. It remains to be clarified in which clinical situations, at what time points and with which dosages the best chances exist for a beneficial effect on the prognosis of these patients

Axon Outgrowth: Motor Protein Moonlights in Microtubule Sliding

SummaryNeurons develop from small, spherical precursors into the largest, most asymmetric of all metazoan cells by extending thin axonal processes over enormous distances. Although the forces for this extension have been unclear, recent work shows that the initial axonal extension may involve an unexpected mechanism: sliding of microtubules, driven by a motor protein previously thought to be deployed only in organelle transport

Binding between the neural cell adhesion molecules axonin-1 and Nr- CAM/Bravo is involved in neuron-glia interaction

Neural cell adhesion molecules of the immunoglobulin superfamily mediate cellular interactions via homophilic binding to identical molecules and heterophilic binding to other family members or structurally unrelated cell-surface glycoproteins. Here we report on an interaction between axonin-1 and Nr-CAM/Bravo. In search for novel ligands of axonin-1, fluorescent polystyrene microspheres conjugated with axonin-1 were found to bind to peripheral glial cells from dorsal root ganglia. By antibody blockage experiments an axonin-1 receptor on the glial cells was identified as Nr-CAM. The specificity of the interaction was confirmed with binding studies using purified axonin-1 and Nr-CAM. In cultures of dissociated dorsal root ganglia antibodies against axonin-1 and Nr-CAM perturbed the formation of contacts between neurites and peripheral glial cells. Together, these results implicate a binding between axonin-1 of the neuritic and Nr-CAM of the glial cell membrane in the early phase of axon ensheathment in the peripheral nervous system

A study of stress gradients in a titanium alloy

A study of the stress gradient developed in a Ti-7AL sample is examined using the technique of High-Energy Diffraction Microscopy. The experiment is conducted at beamline 1-ID of the Advanced Photon Source of Argonne National Laboratory, using high-resolution monochromator. A map of grain orientation in the cross-section of the sample is determined through use of a near-field technique. The near-field study is complemented by analysis using data from a far-field detector to develop lattice strain on a grain-by-grain basis. A state of bending with superposed tension is revealed through correlation of the near-field grain map with the far-field center of mass result. A comparison of “macro” stress and the “grain scale” stresses is featured. An assessment is given on the benefits and limitations of using the high-resolution monochromator in the strain analysis of far-field detector images

How connectivity rules and synaptic properties shape the efficacy of pattern separation in the entorhinal cortex–dentate gyrus–CA3 network

Pattern separation is a fundamental brain computation that converts small differences in input patterns into large differences in output patterns. Several synaptic mechanisms of pattern separation have been proposed, including code expansion, inhibition and plasticity; however, which of these mechanisms play a role in the entorhinal cortex (EC)–dentate gyrus (DG)–CA3 circuit, a classical pattern separation circuit, remains unclear. Here we show that a biologically realistic, full-scale EC–DG–CA3 circuit model, including granule cells (GCs) and parvalbumin-positive inhibitory interneurons (PV+-INs) in the DG, is an efficient pattern separator. Both external gamma-modulated inhibition and internal lateral inhibition mediated by PV+-INs substantially contributed to pattern separation. Both local connectivity and fast signaling at GC–PV+-IN synapses were important for maximum effectiveness. Similarly, mossy fiber synapses with conditional detonator properties contributed to pattern separation. By contrast, perforant path synapses with Hebbian synaptic plasticity and direct EC–CA3 connection shifted the network towards pattern completion. Our results demonstrate that the specific properties of cells and synapses optimize higher-order computations in biological networks and might be useful to improve the deep learning capabilities of technical networks

Complement depletion during haemofiltration with polyacrilonitrile membranes

Background Polyacrylonitrile (PAN, AN69®) dialysis membranes have been shown to improve the outcome of critically ill patients. Factor D is an essential enzyme of the alternative pathway of complement and is increased during renal failure. On the other hand the contact of blood with biomaterials activates the complement cascade through the alternative pathway. PAN filters adsorb factor D which looses its enzymatic activity whilst bound to the membrane [1] the complement alternative pathway function of serum exposed to PAN filters is greatly diminished and restored after addition of purified factor D [1]. The aim of our study was to measure the time course of factor D adsorption and its blood concentration during CVVH in critically ill patients with acute renal failure. Methods We studied seven critically ill patients with ARF before, during and after continuous veno-venous haemofiltration (CVVH) with AN69. Results There was a rapid decrease of factor D levels to 62(±6%) of the pre-CVVH value during the first 2 h, which continued to 51(±7.3%) after 12 h; at 24 h there was a slight rise to 62±12%. Sequential use of Polyacrylonitrile (AN69®) filters lowered factor D levels below the normal plasma concentration in three patients, thus producing a state of factor D depletion. Conclusions The significant reduction of factor D levels during CVVH with PAN filters suggests that frequent changes of PAN filters may reduce alternative pathway function by lowering factor D levels. CVVH (as opposed to intermittent dialysis) with PAN membranes may further improve the outcome of critically ill patient

Swiss Sepsis National Action Plan: A coordinated national action plan to stop sepsis-related preventable deaths and to improve the support of people affected by sepsis in Switzerland

Background: Sepsis is a devastating disease which causes yearly over 10 million deaths worldwide. In 2017, the World Health Organization (WHO) issued a resolution prompting member states to improve the prevention, recognition, and management of sepsis. The 2021 European Sepsis Report revealed that-contrary to other European countries-Switzerland had not yet actioned the sepsis resolution. Methods: A panel of experts convened at a policy workshop to address how to improve awareness, prevention, and treatment of sepsis in Switzerland. Goal of the workshop was to formulate a set of consensus recommendations toward creating a Swiss Sepsis National Action Plan (SSNAP). In a first part, stakeholders presented existing international sepsis quality improvement programs and national health programs relevant for sepsis. Thereafter, the participants were allocated into three working groups to identify opportunities, barriers, and solutions on (i) prevention and awareness, (ii) early detection and treatment, and (iii) support for sepsis survivors. Finally, the entire panel summarized the findings from the working groups and identified priorities and strategies for the SSNAP. All discussions during the workshop were transcribed into the present document. All workshop participants and key experts reviewed the document. Results: The panel formulated 14 recommendations to address sepsis in Switzerland. These focused on four domains, including (i) raising awareness in the community, (ii) improving healthcare workforce training on sepsis recognition and sepsis management; (iii) establishing standards for rapid detection, treatment and follow-up in sepsis patients across all age groups; and (iv) promoting sepsis research with particular focus on diagnostic and interventional trials. Conclusion: There is urgency to tackle sepsis. Switzerland has a unique opportunity to leverage from lessons learnt during the COVID-19 pandemic to address sepsis as the major infection-related threat to society. This report details consensus recommendations, the rationale thereof, and key discussion points made by the stakeholders on the workshop day. The report presents a coordinated national action plan to prevent, measure, and sustainably reduce the personal, financial and societal burden, death and disability arising from sepsis in Switzerland

Photon Assisted Tunneling of Zero Modes in a Majorana Wire

Hybrid nanowires with proximity-induced superconductivity in the topological regime host Majorana zero modes (MZMs) at their ends, and networks of such structures can produce topologically protected qubits. In a double-island geometry where each segment hosts a pair of MZMs, inter-pair coupling mixes the charge parity of the islands and opens an energy gap between the even and odd charge states at the inter-island charge degeneracy. Here, we report on the spectroscopic measurement of such an energy gap in an InAs/Al double-island device by tracking the position of the microwave-induced quasiparticle (qp) transitions using a radio-frequency (rf) charge sensor. In zero magnetic field, photon assisted tunneling (PAT) of Cooper pairs gives rise to resonant lines in the 2e-2e periodic charge stability diagram. In the presence of a magnetic field aligned along the nanowire, resonance lines are observed parallel to the inter-island charge degeneracy of the 1e-1e periodic charge stability diagram, where the 1e periodicity results from a zero-energy sub-gap state that emerges in magnetic field. Resonant lines in the charge stability diagram indicate coherent photon assisted tunneling of single-electron states, changing the parity of the two islands. The dependence of resonant frequency on detuning indicates a sizable (GHz-scale) hybridization of zero modes across the junction separating islands