scholarly journals Development and assessment of the performance of a shared ventilatory system that uses clinically available components to individualize tidal volumes

2020 ◽  
Author(s):  
David M. Hannon ◽  
Tim Jones ◽  
Jack Conolly ◽  
Conor Judge ◽  
Talha Iqbal ◽  
...  
Keyword(s):  
Invasive Mechanical Ventilation ◽  
Ventilation System ◽  
List Type ◽  
Test Lung ◽  
Minimal Impact ◽  
Wide Range ◽  
The Impact ◽  
Ventilator Settings

AbstractObjectivesTo develop and assess the performance of a system for shared ventilation that uses clinically available components to individualize tidal volumes under a variety of clinically relevant conditions.DesignEvaluation and in vitro validation study.SettingVentilator shortage during the SARS-CoV-2 global pandemic.ParticipantsThe design and validation team consisted of intensive care physicians, bioengineers, computer programmers, and representatives from the medtech sector.MethodsUsing standard clinical components, a system of shared ventilation consisting of two ventilatory limbs was assembled and connected to a single ventilator. Individual monitors for each circuit were developed using widely available equipment and open source software. System performance was determined under 2 sets of conditions. First, the effect of altering ventilator settings (Inspiratory Pressure, Respiratory rate, I:E ratio) on the tidal volumes delivered to each lung circuit was determined. Second, the impact of altering the compliance and resistance in one simulated lung circuit on the tidal volumes delivered to that lung and the second lung circuit was determined. All measurements at each setting were repeated three times to determine the variability in the system.ResultsThe system permitted accurate and reproducible titration of tidal volumes to each ‘lung circuit’ over a wide range of ventilator settings and simulated lung conditions. Alteration of ventilator inspiratory pressures stepwise from 4-20cm H2O, of respiratory rates from 6-20 breaths/minute and I:E ratio from 1:1 to 1:4 resulted in near identical tidal volumes delivered under each set of conditions to each simulated ‘lung’. Stepwise alteration of compliance and resistance in one ‘test’ lung circuit resulted in reproducible alterations in tidal volume to the ‘test’ lung, with little change to tidal volumes in the ‘control’ lung (a change of only 6% is noted). All tidal volumes delivered were highly reproducible upon repetition.ConclusionsWe demonstrate the reliability of a simple shared ventilation system assembled using commonly available clinical components that allows individual titration of tidal volumes. This system may be useful as a temporary strategy of last resort where the numbers of patients requiring invasive mechanical ventilation exceeds supply of ventilators.Article SummaryStrengths and limitations of this studyThis solution provides the ability to safely and robustly ventilate two patients simultaneously while allowing differing tidal volumes in each limb.The designed solution uses equipment readily available in most hospitals.Accurate and reproducible titration of tidal volumes to each ‘lung’ was possible over a wide range of ventilator settings.Alteration of one simulated ‘lung’ conditions had minimal impact on the tidal volumes delivered to the unaffected lungThe system relies on patients being sedated and paralysed.We have not yet tested this solution in vivo, on COVID-19 patients.

scholarly journals In VivoEfficacy of Anuran Trypsin Inhibitory Peptides against Staphylococcal Skin Infection and the Impact of Peptide Cyclization

2015 ◽  
Vol 59 (4) ◽  
pp. 2113-2121 ◽  
Author(s):  
U. Malik ◽  
O. N. Silva ◽  
I. C. M. Fensterseifer ◽  
L. Y. Chan ◽  
R. J. Clark ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Sequence Similarity ◽  
Infection Model ◽  
Content Type ◽  
Wide Range ◽  
Inhibitory Activities ◽  
The Impact

ABSTRACTStaphylococcus aureusis a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem, and the development of novel antimicrobial agents is crucial. Antimicrobial peptides from natural resources offer potential as new treatments against staphylococcal infections. In the current study, we have examined the antimicrobial properties of peptides isolated from anuran skin secretions and cyclized synthetic analogues of these peptides. The structures of the peptides were elucidated by nuclear magnetic resonance (NMR) spectroscopy, revealing high structural and sequence similarity with each other and with sunflower trypsin inhibitor 1 (SFTI-1). SFTI-1 is an ultrastable cyclic peptide isolated from sunflower seeds that has subnanomolar trypsin inhibitory activity, and this scaffold offers pharmaceutically relevant characteristics. The five anuran peptides were nonhemolytic and noncytotoxic and had trypsin inhibitory activities similar to that of SFTI-1. They demonstrated weakin vitroinhibitory activities againstS. aureus, but several had strong antibacterial activities againstS. aureusin anin vivomurine wound infection model. pYR, an immunomodulatory peptide fromRana sevosa, was the most potent, with complete bacterial clearance at 3 mg · kg−1. Cyclization of the peptides improved their stability but was associated with a concomitant decrease in antimicrobial activity. In summary, these anuran peptides are promising as novel therapeutic agents for treating infections from a clinically resistant pathogen.

Partially desulfated heparin modulates the interaction between anti-protamine/heparin antibodies and platelets

2016 ◽  
Vol 115 (02) ◽  
pp. 324-332 ◽  
Author(s):  
Rabie Jouni ◽  
Heike Zöllner ◽  
Ahmad Khadour ◽  
Jan Wesche ◽  
Anne Grotevendt ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Platelet Factor ◽  
Standard Drug ◽  
Platelet Surface ◽  
Minimal Impact ◽  
Platelet Survival ◽  
Heparin Complexes ◽  
The Impact

SummaryProtamine (PRT) is the standard drug to neutralise heparin. PRT/heparin complexes induce an immune response similar to that observed in heparin-induced thrombocytopenia (HIT). Partially desulfated heparin (ODSH) was shown to interfere with anti-platelet factor 4/heparin antibodies (Abs), which are responsible for HIT. In this study, we analyse the impact of ODSH on the interaction between anti-PRT/heparin Abs and platelets. The ability of ODSH to prevent anti-PRT/heparin Ab-induced platelet destruction in vivo was investigated using the NOD/ SCID mouse model. ODSH improved platelet survival in the presence of PRT, heparin and anti-PRT/heparin Abs (median platelet survival after 300 minutes (min) with 20 μg/ml ODSH: 75 %, range 70–81 % vs without ODSH: 49%, range 44–59%, p=0.006). Furthermore, when ODSH was applied 60 min after Ab injection platelet survival was improved (median platelet survival after 300 min with ODSH: 83 %, range 77–93 % vs without ODSH: 59 %, range 29–61 %, p=0.02). In in vitro experiments ODSH inhibited platelet activation at concentrations > 16 μg/mL (p< 0.001), as well as PRT/heparin complex binding to platelets (mean fluorescence intensity [MFI] without ODSH: 85 ± 14 vs with ODSH: 15 ± 0.6, p=0.013). ODSH also displaced pre-bound complexes from the platelet surface (MFI without ODSH: 324 ± 43 vs with 32 μg/ml ODSH: 53 ± 9, p< 0.001). While interfering with platelet activation by anti-PRT/heparin Abs, up to a concentration of 16 μg/ml, ODSH had only minimal impact on neutralisation of heparin by PRT. In conclusion, our study shows that ODSH is able to inhibit platelet activation and destruction suggesting a potential clinical use to reduce anti-PRT/heparin Ab-mediated adverse effects.

scholarly journals Sensing through Non-Sensing Ocular Ion Channels

2020 ◽  
Vol 21 (18) ◽  
pp. 6925
Author(s):  
Meha Kabra ◽  
Bikash Ranjan Pattnaik
Keyword(s):  
Ion Channels ◽  
Visual Processing ◽  
Signal Transmission ◽  
Dominant Negative ◽  
Dominant Negative Effect ◽  
Cone Dystrophy ◽  
Wide Range ◽  
The Impact

Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the eye. In the eye, ion channels are involved in various physiological processes, like signal transmission and visual processing. A wide range of mutations have been reported in the corresponding genes and their interacting subunit coding genes, which contribute significantly to an array of blindness, termed ocular channelopathies. These mutations result in either a loss- or gain-of channel functions affecting the structure, assembly, trafficking, and localization of channel proteins. A dominant-negative effect is caused in a few channels formed by the assembly of several subunits that exist as homo- or heteromeric proteins. Here, we review the role of different mutations in switching a “sensing” ion channel to “non-sensing,” leading to ocular channelopathies like Leber’s congenital amaurosis 16 (LCA16), cone dystrophy, congenital stationary night blindness (CSNB), achromatopsia, bestrophinopathies, retinitis pigmentosa, etc. We also discuss the various in vitro and in vivo disease models available to investigate the impact of mutations on channel properties, to dissect the disease mechanism, and understand the pathophysiology. Innovating the potential pharmacological and therapeutic approaches and their efficient delivery to the eye for reversing a “non-sensing” channel to “sensing” would be life-changing.

Plasma Deposition of Biomolecules for Enhanced Biomedical Applications

2015 ◽  
Vol 1723 ◽  
Author(s):  
Liam O’Neill ◽  
Barry Twomey ◽  
Peter Dobbyn ◽  
John O’Donoghue
Keyword(s):  
Wound Healing ◽  
Chronic Wounds ◽  
Plasma Deposition ◽  
Preclinical Trial ◽  
Minimal Impact ◽  
Plasma Device ◽  
Biological Performance ◽  
The Impact

ABSTRACTBiomolecules have been traditionally immobilised onto surfaces using wet chemical techniques for various medical applications. Recent decades have seen plasma methods being used to prepare these surfaces through various forms of surface modification, but the direct exposure of biomolecules to plasma has been avoided due to fears that the molecules would be denatured by the energetic plasma species. Recent results are now demonstrating that direct plasma deposition of biomolecule coatings can be achieved. This creates the possibility to directly modify the surface of implants without any form of surface pre-treatment and this opens up the possibility to alter the healing processes. Materials such as collagen, chitosan, catalase and heparin can be effectively deposited onto surfaces with minimal impact on biological performance and without any chemical binders, linkers or impurities. The performance of these materials has been characterised using both in vitro and in vivo methodologies. In a further step, the results of a preclinical trial are presented which reveal that direct deposition of biomolecules onto open wounds can also be achieved and the impact of this on wound healing is measured in an immunocompromised animal model. A non-thermal plasma device was used to deliver collagen on to chronic wounds and the treatment was shown to promote wound closure in a rabbit wound healing model.

scholarly journals Optogenetic control of protein binding using light-switchable nanobodies

2019 ◽  
Author(s):  
Agnieszka A. Gil ◽  
Evan M. Zhao ◽  
Maxwell Z. Wilson ◽  
Alexander G. Goglia ◽  
Cesar Carrasco-Lopez ◽  
...  
Keyword(s):  
Protein Binding ◽  
Target Protein ◽  
Size Exclusion ◽  
Light Illumination ◽  
List Type ◽  
Target Proteins ◽  
Wide Range ◽  
Endogenous Target

AbstractA growing number of optogenetic tools have been developed to control binding between two engineered protein domains. In contrast, relatively few tools confer light-switchable binding to a generic target protein of interest. Such a capability would offer substantial advantages, enabling photoswitchable binding to endogenous target proteins in vivo or light-based protein purification in vitro. Here, we report the development of opto-nanobodies (OptoNBs), a versatile class of chimeric photoswitchable proteins whose binding to proteins of interest can be enhanced or inhibited upon blue light illumination. We find that OptoNBs are suitable for a range of applications: modulating intracellular protein localization and signaling pathway activity and controlling target protein binding to surfaces and in protein separation columns. This work represents a first step towards programmable photoswitchable regulation of untagged, endogenous target proteins.HighlightsOpto-Nanobodies (OptoNBs) enable light-regulated binding to a wide range of protein targets.We identify an optimized LOV domain and two loop insertion sites for light-regulated binding.OptoNBs function in vivo: when expressed in cells and fused to signaling domains, OptoNBs enable light-activated and light-inhibited Ras/Erk signaling.OptoNBs function in vitro: Target proteins can be reversibly bound to OptoNB-coated beads and separated through size-exclusion chromatography.

Photopatterned Membranes and Chemical Gradients Enable Scalable Phenotypic Organization of Primary Human Colon Epithelial Models

2019 ◽  
Author(s):  
Sam Hinman ◽  
Yuli Wang ◽  
Nancy Allbritton
Keyword(s):  
Human Colon ◽  
Cell Types ◽  
Self Renewal ◽  
Chemical Gradients ◽  
Plate Spacing ◽  
Wide Range ◽  
Cell Compartmentalization ◽  
The Impact

Biochemical gradients across the intestinal epithelium play a major role in governing intestinal stem cell compartmentalization, differentiation dynamics, and organ-level self-renewal. Advances in primary cell-derived <i>in vitro</i> models, in which a full suite of stem and differentiated cell types are present, have vastly accelerated our understanding of intestinal homeostasis and disease. However, scalable platforms that recapitulate the architecture and gradients present <i>in vivo</i> are absent. We present a platform in which individually addressable arrays of chemical gradients along the crypt long axis can be generated, enabling scalable culture of <i>in vitro</i> colonic epithelial replicas. The platform utilizes standardized well plate spacing, maintains access to basal and luminal compartments, and relies on a photopatterned porous membrane to act as diffusion windows while supporting the<i> in vitro </i>crypts. Simultaneous fabrication of 3,875 crypts over a single membrane was developed. Growth factor gradients were modelled and then experimentally optimized to promote long-term health and self-renewal of the crypts which were assayed <i>in situ</i> by confocal fluorescence microscopy. The cultured <i>in vitro</i> crypt arrays successfully recapitulated the architecture, stem/proliferative and differentiated cell compartmentalization, and luminal-to-basal polarity observed <i>in vivo</i>. Furthermore, known signaling regulators produced measurable and predictable effects on the proliferative and differentiated cell compartments. This platform is readily adaptable to the screening of tissue from individual patients to assay the impact of food and bacterial metabolites and/or drugs on colonic crypt dynamics. Importantly, the cassette is compatible with a wide range of sensing/detection modalities, and the developed fabrication methods should find applications for other cell and tissue types.

scholarly journals Immunotoxic Effects Induced by Microcystins and Cylindrospermopsin: A Review

Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 711
Author(s):  
Leticia Diez-Quijada ◽  
Maria del Monte Benítez-González ◽  
María Puerto ◽  
Angeles Jos ◽  
Ana M. Cameán
Keyword(s):  
Immune System ◽  
Scientific Literature ◽  
Anthropogenic Activities ◽  
In Vivo Studies ◽  
Wide Range ◽  
Full Picture ◽  
Underlying Mechanisms ◽  
The Impact

Cyanotoxin occurrence is gaining importance due to anthropogenic activities, climate change and eutrophication. Among them, Microcystins (MCs) and Cylindrospermopsin (CYN) are the most frequently studied due to their ubiquity and toxicity. Although MCs are primary classified as hepatotoxins and CYN as a cytotoxin, they have been shown to induce deleterious effects in a wide range of organs. However, their effects on the immune system are as yet scarcely investigated. Thus, to know the impact of cyanotoxins on the immune system, due to its importance in organisms’ homeostasis, is considered of interest. A review of the scientific literature dealing with the immunotoxicity of MCs and CYN has been performed, and both in vitro and in vivo studies have been considered. Results have confirmed the scarcity of reports on the topic, particularly for CYN. Decreased cell viability, apoptosis or altered functions of immune cells, and changed levels and mRNA expression of cytokines are among the most common effects reported. Underlying mechanisms, however, are still not yet fully elucidated. Further research is needed in order to have a full picture of cyanotoxin immunotoxicity.

scholarly journals Reconstitution of eukaryotic chromosomes and manipulation of DNA N6-methyladenine alters chromatin and gene expression

2018 ◽  
Author(s):  
Leslie Y. Beh ◽  
Galia T. Debelouchina ◽  
Derek M. Clay ◽  
Robert E. Thompson ◽  
Kelsi A. Lindblad ◽  
...  
Keyword(s):  
De Novo ◽  
Nucleosome Occupancy ◽  
Dna Methyltransferases ◽  
Chromatin Organization ◽  
Sexual Cycle ◽  
List Type ◽  
Adenine Methylation ◽  
The Impact

SummaryDNA N6-adenine methylation (6mA) has recently been reported in diverse eukaryotes, spanning unicellular organisms to metazoans. Yet the functional significance of 6mA remains elusive due to its low abundance, difficulty of manipulation within native DNA, and lack of understanding of eukaryotic 6mA writers. Here, we report a novel DNA 6mA methyltransferase in ciliates, termed MTA1. The enzyme contains an MT-A70 domain but is phylogenetically distinct from all known RNA and DNA methyltransferases. Disruption of MTA1in vivoleads to the genome-wide loss of 6mA in asexually growing cells and abolishment of the consensus ApT dimethylated motif. Genes exhibit subtle changes in chromatin organization or RNA expression upon loss of 6mA, depending on their starting methylation level. Mutants fail to complete the sexual cycle, which normally coincides with a peak of MTA1 expression. Thus, MTA1 functions in a developmental stage-specific manner. We determine the impact of 6mA on chromatin organizationin vitroby reconstructing complete, full-length ciliate chromosomes harboring 6mA in native or ectopic positions. Using these synthetic chromosomes, we show that 6mA directly disfavors nucleosomesin vitroin a local, quantitative manner, independent of DNA sequence. Furthermore, the chromatin remodeler ACF can overcome this effect. Our study identifies a novel MT-A70 protein necessary for eukaryotic 6mA methylation and defines the impact of 6mA on chromatin organization using epigenetically defined synthetic chromosomes.HighlightsThe MT-A70 protein MTA1 mediates DNA N6-adenine methylation inOxytrichaMTA1 mutants exhibit subtle changes in nucleosome organization and transcriptionin vivo6mA directly disfavors nucleosome occupancy in natural and synthetic chromosomesin vitroDe novosynthesis of complete, epigenetically definedOxytrichachromosomes

Photopatterned Membranes and Chemical Gradients Enable Scalable Phenotypic Organization of Primary Human Colon Epithelial Models

2019 ◽  
Author(s):  
Sam Hinman ◽  
Yuli Wang ◽  
Nancy Allbritton
Keyword(s):  
Human Colon ◽  
Cell Types ◽  
Self Renewal ◽  
Chemical Gradients ◽  
Plate Spacing ◽  
Wide Range ◽  
Cell Compartmentalization ◽  
The Impact

Biochemical gradients across the intestinal epithelium play a major role in governing intestinal stem cell compartmentalization, differentiation dynamics, and organ-level self-renewal. Advances in primary cell-derived <i>in vitro</i> models, in which a full suite of stem and differentiated cell types are present, have vastly accelerated our understanding of intestinal homeostasis and disease. However, scalable platforms that recapitulate the architecture and gradients present <i>in vivo</i> are absent. We present a platform in which individually addressable arrays of chemical gradients along the crypt long axis can be generated, enabling scalable culture of <i>in vitro</i> colonic epithelial replicas. The platform utilizes standardized well plate spacing, maintains access to basal and luminal compartments, and relies on a photopatterned porous membrane to act as diffusion windows while supporting the<i> in vitro </i>crypts. Simultaneous fabrication of 3,875 crypts over a single membrane was developed. Growth factor gradients were modelled and then experimentally optimized to promote long-term health and self-renewal of the crypts which were assayed <i>in situ</i> by confocal fluorescence microscopy. The cultured <i>in vitro</i> crypt arrays successfully recapitulated the architecture, stem/proliferative and differentiated cell compartmentalization, and luminal-to-basal polarity observed <i>in vivo</i>. Furthermore, known signaling regulators produced measurable and predictable effects on the proliferative and differentiated cell compartments. This platform is readily adaptable to the screening of tissue from individual patients to assay the impact of food and bacterial metabolites and/or drugs on colonic crypt dynamics. Importantly, the cassette is compatible with a wide range of sensing/detection modalities, and the developed fabrication methods should find applications for other cell and tissue types.

scholarly journals 687 Enhancement of anti-tumor immunity by ICT01: a novel g9d2 T cell-activating antibody targeting butyrophilin-3A (BTN3A)

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A726-A726
Author(s):  
Aude de Gassart ◽  
Patrick Brune ◽  
LE Suong ◽  
Sophie Agaugue ◽  
Emmanuel Valentin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
T Cell Activation ◽  
Cell Subset ◽  
List Type ◽  
Human Cancers ◽  
Wide Range

BackgroundgdT-cells are innate-like lymphocytes described as potent killer of cancer cells whose infiltration into tumors is associated with a positive prognosis.1 2 This supports gd T-cells use in cancer immunotherapy. BTN3A, which belongs to the B7-subfamily of Ig proteins, is required for the recognition of malignant or infected cells by human g9d2 T-cells by sensing intracellular accumulation of phosphoantigens.3 ImCheck Therapeutics is developing ICT01, a humanized anti-BTN3A (IgG1, Fc-silenced), g9d2 T-cell-activating antibody for the treatment of patients with solid or hematologic tumors.MethodsA complete IND-enabling program was conducted to characterize the preclinical activity and safety of ICT01. ICT01 effects on human and cynomolgus PBMCs were characterized in vitro using flow cytometry. ICT01-mediated killing activity of g9d2 T-cells was assessed using in vitro co-cultures with tumor and non-tumor cells. Immunocompromised mice bearing human tumors and adoptively transferred with human g9d2 T cells were used to assess ICT01 anti-tumor activity in vivo. The PK, PD and safety of intravenous ICT01 (0.1 to 100 mg/kg single- and repeated-dose) were evaluated in Cynomolgus monkeys.ResultsICT01 selectively binds to all three BTN3A isoforms with high affinity (<10nM). When assayed in human and cynomolgus PBMCs in vitro, ICT01 promoted a robust and specific activation of g9d2 T-cells as shown by concentration dependent increase in cell surface CD69 and CD25 and cytokines secretion (IFNγ, TNFα). In co-culture experiments, ~20% of target occupancy on tumor cells is sufficient for maximal g9d2 T-cell degranulation (e.g. CD107a/b expression). ICT01-activated g9d2 T-cells continuously and serially kill a wide range of tumor cells in multi-day co-culture conditions. In contrast, non-tumoral BTN3A-expressing B cells, HUVEC and fibroblasts were unaffected. In mouse AML and ovarian cancer models, repeated injections of ICT01 delayed tumor growth and significantly prolonged animal survival. In primates, ICT01 exposure and target engagement was dose-dependent, with all tested doses producing a specific g9d2 T cell activation and trafficking out of the circulation within 1 hour. ICT01 administration was well tolerated with no safety signals observed at doses up to 25 mg/kg/week based on clinical, laboratory, and anatomic pathology parameters.ConclusionsThe combined in vitro and in vivo pharmacology data provide evidence that ICT01 is an attractive and novel therapeutic approach for enhancing the innate anti-tumor potential of g9d2 T-cells by activating BTN3A. Importantly, ICT01 did not affect healthy BTN3A-expressing cells, and NHP studies confirmed ICT01 safety with a wide therapeutic index. Therefore, ICT01 is being tested in the ongoing EVICTION trial (NCT04243499).Ethics ApprovalPseudonymized samples isolated from healthy volunteers’ whole blood by ImCheck Therapeutics under the agreement n° 7173 between ImCheck Therapeutic SAS and EFS PACA (Etablissement Français du Sang Provence-Alpes-cote d’Azur)ReferencesGentles AJ, Newman AM, Liu CL, et al. The prognostic landscape of genes and infiltrating immune cells across human cancers. Nature Medicine 2015;21(8):938–945.Tosolini M, Pont F, Poupot M, et al. Assessment of tumor-infiltrating TCRVγ9Vδ2 γδ lymphocyte abundance by deconvolution of human cancers microarrays. OncoImmunology. 2017;6(3):e1284723.Harly C, Guillaume Y, Nedellec S, et al. Key implication of CD277/butyrophilin-3 (BTN3A) in cellular stress sensing by a major human γδ T-cell subset. Blood 2012;120(11):2269–2279.

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