Search

Abstract Cytokinesis partitions cellular content between daughter cells. It relies on the formation of an acto-myosin contractile ring, whose constriction induces the ingression of the cleavage furrow between the segregated chromatids. Rho1 GTPase and its RhoGEF (Pbl) are essential for this process. However, how Rho1 is regulated to sustain furrow ingression while maintaining correct furrow position remains poorly defined. Here, we show that during asymmetric division of Drosophila neuroblasts, Rho1 is controlled by two Pbl isoforms with distinct localisation. Spindle midzone- and furrow-enriched Pbl-A focuses Rho1 at the furrow to sustain efficient ingression, while Pbl-B pan-plasma membrane localization promotes the broadening of Rho1 activity and the subsequent enrichment of myosin on the entire cortex. This enlarged zone of Rho1 activity is critical to adjust furrow position, thereby preserving correct daughter cell size asymmetry. Our work highlights how the use of isoforms with distinct localisation makes an essential process more robust.

The aim of the present study was to evaluate the effect of activin A on the activation of in vitro folliculogenesis of human ovarian tissues from transgender men with or without our new compartmented chitosan hydrogel microbioreactor (“three-dimensional (3D)-structure”) enabling a three-dimensional tissue culture. Five fresh ovarian human tissues were cultured in vitro for 20 or 22 days in four groups with 100 ng/mL activin A or without activin A during the last six to eight days of culture, and within a 3D-structure or without the 3D-structure in standard conditions. Follicular density and quality were evaluated, and follicular diameters were measured. Estradiol secretion was quantified. Proliferation and apoptosis through immunostaining were also performed. The proportion of primordial follicles was significantly reduced, and the proportion of primary and secondary follicles was significantly increased in all four groups (p < 0.001). Tertiary follicles were observed in the four culture groups. Activin A supplementation did not significantly affect the follicular density, follicular quality, follicular growth, or estradiol secretion (p > 0.05). The 3D-structure increased the density of primary follicles and decreased the estradiol secretion (p < 0.001). Follicular proliferation was significantly lower in the 3D-structure group compared to the non-3D-structure group (p = 0.008). Regarding follicular apoptosis, it was significantly higher in the activin group compared to the non-activin group (p = 0.006). Activin A did not seem to play a key role in the in vitro folliculogenesis activation in our culture conditions. However, the results may indicate that the 3D-structure could be more physiological and could prevent a detrimental in vitro folliculogenesis flare-up.

Abstract In this article, we report the conception and the use of dialysis-based medical device for the extraction of metals. The medical device is obtained by addition in the dialysate of a functionalized chitosan that can chelate endogenous metals like iron or copper. This water-soluble functionalized chitosan is obtained after controlled reacetylation and grafting of DOTAGA. Due to the high mass of chitosan, the polymer cannot cross through the membrane and the metals are trapped in the dialysate during hemodialysis. Copper extraction has been evaluated in vitro using an hemodialysis protocol. Feasibility study has been performed on healthy sheep showing no acute toxicity througout the entire dialysis procedure and first insights of metallic extraction even on healthy animals.

For the last twenty years, the number of participative approaches in the field of landscape architecture has increased. Although many different ideas have been experimented with, none of these has necessarily been firmly based on theoretical or methodological fundamentals. By making a detailed analysis of approximately twenty participative landscape projects carried out over the last fifteen years in Europe, we propose a "matrix" that can be used as a basis for reflecting on the implementation, analysis and/or evaluation of participative landscape projects. Our primary aim is to shed light on the conditions and means of implementation of these approaches adapted to targeted objectives.

Anthony Cahn,1 J Nicole Hamblin,2 Jon Robertson,3 Malcolm Begg,2 Emily Jarvis,3 Robert Wilson,1 Gordon Dear,4 Claudia Leemereise,5 Yi Cui,6 Maki Mizuma,7 Mickael Montembault,8 Cedric Van Holsbeke,9 Wim Vos,9 Wilfried De Backer,10 Jan De Backer,9 Edith M Hessel2 1Discovery Medicine, GlaxoSmithKline, Stevenage, UK; 2Refractory Respiratory Inflammation Discovery Performance Unit, GlaxoSmithKline, Stevenage, UK; 3Biostatistics, GlaxoSmithKline, Stevenage, UK; 4Mechanistic Safety & Disposition, GlaxoSmithKline, Ware, UK; 5Global Clinical Sciences & Delivery, GlaxoSmithKline, Amersfoort, the Netherlands; 6Pharma Safety, GlaxoSmithKline, Brentford, Middlesex, UK; 7Data Management & Strategy, GlaxoSmithKline, Tokyo, Japan; 8Global Clinical Sciences & Delivery, GlaxoSmithKline, Brentford, Middlesex, UK; 9FLUIDDA nv, Kontich, 2550, Belgium; 10Pulmonary Medicine & Pulmonary Rehabilitation, University of Antwerp, Antwerp, BelgiumCorrespondence: Anthony CahnDiscovery Medicine, GlaxoSmithKline, Stevenage, UKTel +44 1438766374Email tony.x.cahn@gsk.comPurpose: This study evaluated the safety and efficacy of inhaled nemiralisib, a phosphoinositide 3-kinase δ (PI3Kδ) inhibitor, in patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD).Methods: In this double-blind, placebo-controlled study, 126 patients (40– 80 years with a post-bronchodilator forced expiratory volume in 1 sec (FEV1) ≤ 80% of predicted (previously documented)) were randomized 1:1 to once daily inhaled nemiralisib (1 mg) or placebo for 84 days, added to standard of care. The primary endpoint was specific imaging airway volume (siVaw) after 28 treatment days and was analyzed using a Bayesian repeated measures model (clintrials.gov: NCT02294734).Results: A total of 126 patients were randomized to treatment; 55 on active treatment and 49 on placebo completed the study. When comparing nemiralisib and placebo-treated patients, an 18% placebo-corrected increase from baseline in distal siVaw (95% credible intervals (Cr I) (− 1%, 42%)) was observed on Day 28. The probability that the true treatment ratio was > 0% (Pr(θ> 0)) was 96%, suggestive of a real treatment effect. Improvements were observed across all lung lobes. Patients treated with nemiralisib experienced a 107.3 mL improvement in posterior median FEV1 (change from baseline, 95% Cr I (− 2.1, 215.5)) at day 84, compared with placebo. Adverse events were reported by 41 patients on placebo and 49 on nemiralisib, the most common being post-inhalation cough on nemiralisib (35%) vs placebo (3%).Conclusion: These data show that addition of nemiralisib to usual care delivers more effective recovery from an acute exacerbation and improves lung function parameters including siVaw and FEV1. Although post-inhalation cough was identified, nemiralisib was otherwise well tolerated, providing a promising novel therapy for this acutely ill patient group.Keywords: acute exacerbation, COPD, nemiralisib

Current pulpotomy is limited in its ability to induce regeneration of the dental-pulp (DP) complex. Hydrogels are reported to be well-suited for tissue engineering and are unlikely to induce an inflammatory response that might damage the remaining tissue. The present study investigated the molecular and cellular actors in the early inflammatory/immune response and deciphered M1/M2 macrophage polarisation to a chitosan-enriched fibrin hydrogel in pulpotomised rat incisors. Both fibrin and fibrin-chitosan hydrogels induced a strong increase in interleukin-6 (IL-6) transcript in the DP when compared to the DP of untreated teeth. Gene expression of other inflammatory mediators was not significantly modified after 3 h. In the viable DP cell population, the percentage of leukocytes assessed by flow cytometry was similar to fibrin and fibrin-chitosan hydrogels after 1 d. In this leukocyte population, the proportion of granulocytes increased beneath both hydrogels whereas the antigen-presenting cell, myeloid dendritic cells, T cells and B cells decreased. The natural killer (NK) cell population was significantly decreased only in DPs from teeth treated with fibrin-chitosan hydrogel. Immunolabeling analysis of the DP/hydrogel interface showed accumulation of neutrophil granulocytes in contact with both hydrogels 1 d after treatment. The DP close to this granulocyte area contained M2 but no M1 macrophages. These data collectively demonstrated that fibrin-chitosan hydrogels induced an inflammatory/immune response similar to that of the fibrin hydrogel. The results confirmed the potential clinical use of fibrin-chitosan hydrogel as a new scaffold for vital-pulp therapies.

Background and Objectives: To test the long-term ability of human ovarian cortex cells to develop in unconventional culture conditions. Materials and Methods. Ovarian cortex cells from fetuses aged 23 to 39 weeks gestation were cultured for 90 days in hollow chitosan hydrogel micro-bioreactors and concurrently in traditional wells. Various cell-type counts were considered. Results: With intact follicles as a denominator, the percentage of growing intact follicles at Day 0 varied widely between ovaries (0 to 31.7%). This percentage tended to increase or stay relatively constant in bioreactor as in control cultures; it tended more toward an increase over time in bioreactor vs. control cultures. Modeled percentages showed differences (though not significant) in favor of bioreactor cultures (16.12% difference at D50 but only 0.12% difference at D90). With all follicles present as a denominator, the percentage of growing primary and secondary follicles at D0 varied widely between ovaries (0 to 29.3%). This percentage tended to increase over time in bioreactor cultures but to decrease in control cultures. Modeled percentages showed significant differences in favor of bioreactor cultures (8.9% difference at D50 and 11.1% difference at D90). At D50 and D90, there were only few and sparse apoptotic cells in bioreactor cultures vs. no apoptotic cells in control cultures. Conclusions: Over three months, bioreactor folliculogenesis outperformed slightly traditional culture. This is an interesting perspective for follicle preservation and long-term toxicological studies.

Vectorization of microRNAs has shown to be a smart approach for their potential delivery to treat many diseases (i.e., cancer, osteopathy, vascular, and infectious diseases). However, there are barriers to genetic in vivo delivery regarding stability, targeting, specificity, and internalization. Polymeric nanoparticles can be very promising candidates to overcome these challenges. One of the most suitable polymers for this purpose is chitosan. Chitosan (CS), a biodegradable biocompatible natural polysaccharide, has always been of interest for drug and gene delivery. Being cationic, chitosan can easily form particles with anionic polymers to encapsulate microRNA or even complex readily forming polyplexes. However, fine tuning of chitosan characteristics is necessary for a successful formulation. In this review, we cover all chitosan miRNA formulations investigated in the last 10 years, to the best of our knowledge, so that we can distinguish their differences in terms of materials, formulation processes, and intended applications. The factors that make some optimized systems superior to their predecessors are also discussed to reach the highest potential of chitosan microRNA nanocarriers.

Due to limited space and resources, it can be difficult to train students on audiological procedures adequately. In the present study, we compared audiology training outcomes between a traditional approach and a recently developed immersive virtual reality (VR) approach in audiology students. Twenty-nine first-year audiology students participated in the study; 14 received traditional training ("TT group"), and 15 received the VR training ("VRT group"). Pre- and post-training evaluation included a 20-item test developed by an audiology educator. Post-training satisfaction and self-confidence were evaluated using Likert scales. Mean post-training test scores improved by 6.9±9.8 percentage points in the TT group and by 21.1±7.8 points in the VRT group; the improvement in scores was significant for both groups. After completing the traditional training, the TT group was subsequently trained with the VR system, after which mean scores further improved by 7.5 points; there was no significant difference in post-VR training scores between the TT and VRT groups. After training, the TT and VRT groups completed satisfaction and self-confidence questionnaires. Satisfaction and self-confidence ratings were significantly higher for the VR training group, compared to the traditional training group. Satisfaction ratings were "good" (4 on Likert scale) for 74% of the TT group and 100% of the VRT group. Self-confidence ratings were "good" for 71% of the TT group and 92% of the VRT group. These results suggest that a VR training approach may be an effective alternative or supplement to traditional training for audiology students.

Chromatid segregation must be coordinated with cytokinesis to preserve genomic stability. Here the authors show that cells clear trailing chromatids from the cleavage site in a two-step cell elongation and demonstrate the role of myosin efflux in the second phase.

The development of non-cellularized composites of chitosan (CHI) hydrogels, filled with cellulose nanofibers (CNFs) of the type nanofibrillated cellulose, was proposed for the repair and regeneration of the intervertebral disc (IVD) annulus fibrosus (AF) tissue. With the achievement of CNF-filled CHI hydrogels, biomaterial-based implants were designed to restore damaged/degenerated discs. The structural, mechanical and biological properties of the developed hydrogel composites were investigated. The neutralization of weakly acidic aqueous CNF/CHI viscous suspensions in NaOH yielded composites of physical hydrogels in which the cellulose nanofibers reinforced the CHI matrix, as investigated by means of microtensile testing under controlled humidity. We assessed the suitability of the achieved biomaterials for intervertebral disc tissue engineering in ex vivo experiments using spine pig models. Cellulose nanofiber-filled chitosan hydrogels can be used as implants in AF tissue defects to restore IVD biomechanics and constitute contention patches against disc nucleus protrusion while serving as support for IVD regeneration.