Novel modulatory effects of neurosteroids and benzodiazepines on excitatory and inhibitory neurons excitability: a multi-electrode array (MEA) recording study.

The dynamic equilibrium between glutamate- and GABA-mediated synaptic neurotransmission in the brain is fundamental to the control of nervous system function. Such a balance is regulated by the \u2018tonic\u2019 release of a variety of neurotransmitters and endogenous factors that influence synaptic function. One such important group of modulatory molecules are the neurosteroids (NSs) which, similarly to benzodiazepines (BDZs), enhance GABAergic neurotransmission. The purpose of our work was to investigate, at in-vivo physiologically relevant concentrations, the effects of these two classes of GABA modulators on dissociated neocortical neuron networks grown in long-term culture. We used a multi-electrode array (MEA) recording technique and a novel method of analysis that was able to both identify the action potentials of engaged excitatory and inhibitory neurons and to detect novel drug-induced network up-states (burst). We found that the NSs tetrahydrodeoxycorticosterone (THDOC) and allopregnanolone (ALLO) applied at low nanomolar concentrations, produced different modulatory effects on the two neuronal clusters. Conversely, at high concentrations (1 \ub5M), both NSs, decreased excitatory and inhibitory neuron cluster excitability; however, even several hours after washout, the excitability of inhibitory neurons continued to be depressed, leading to a network long term depression (LTD). The BDZs clonazepam (CLZ) and midazolam (MDZ) also decreased the network excitability, but only MDZ caused LTD of inhibitory neuron cluster. To investigate the origin of the LTD after MDZ application, we tested finasteride (FIN), an inhibitor of endogenous NSs synthesis. FIN did not prevent the LTD induced by MDZ, but surprisingly induced it after application of CLZ. The significance and possible mechanisms underlying these LTD effects of NSs and BDZs are discussed. Taken together, our results not only demonstrate that ex-vivo neuronal networks show a sensitivity to drugs comparable to that expressed in vivo, but also provide a new global in-vitro description of the physiological mode of action of NSs and BDZs that can help in understanding their activity in more complex systems

Nanoindentation Response of 3D Printed PEGDA Hydrogels in a Hydrated Environment

Hydrogels are commonly used materials in tissue engineering and organ-on-chip devices. This study investigated the nanomechanical properties of monolithic and multilayered poly(ethylene glycol) diacrylate (PEGDA) hydrogels manufactured using bulk polymerization and layer-by-layer projection lithography processes, respectively. An increase in the number of layers (or reduction in layer thickness) from 1 to 8 and further to 60 results in a reduction in the elastic modulus from 5.53 to 1.69 and further to 0.67 MPa, respectively. It was found that a decrease in the number of layers induces a lower creep index (CIT) in three-dimensional (3D) printed PEGDA hydrogels. This reduction is attributed to mesoscale imperfections that appear as pockets of voids at the interfaces of the multilayered hydrogels attributed to localized regions of unreacted prepolymers, resulting in variations in defect density in the samples examined. An increase in the degree of cross-linking introduced by a higher dosage of ultraviolet (UV) exposure leads to a higher elastic modulus. This implies that the elastic modulus and creep behavior of hydrogels are governed and influenced by the degree of cross-linking and defect density of the layers and interfaces. These findings can guide an optimal manufacturing pathway to obtain the desirable nanomechanical properties in 3D printed PEGDA hydrogels, critical for the performance of living cells and tissues, which can be engineered through control of the fabrication parameters

Cross-linking of hydroxyl-terminated polyols with triethyleneglycol diglycidyl ether: an alternative to toxic isocyanates

Isocyanates are highly reactive and toxic substances with severe health effects. Certain diisocyanates are restricted under REACH – The European Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals. Triethyleneglycol diglycidyl ether (TEGDGE) was used as an alternative to toxic isocyanates for the cross-linking of hydroxyl-terminated pre-polymers at 70oC. The effect of three curing accelerators was determined while following the reaction kinetics by 1H-NMR spectroscopy and differential scanning calorimetry (DSC). Polybutadiene (Poly BD R45HT-LO) and acrylic ester (HyTemp 4454) successfully cross-linked in 7–10 days to produce thermally stable networks with low glass transition temperatures, as observed by DSC. Pre-aging the polybutadiene resin promoted cross-linking with TEGDGE. Four energetic compositions were then prepared using cyclotrimethylenetrinitramine (RDX) and pentaerythritoltetranitrate (PETN) as fillers, and polybutadiene (Poly BD R45HT-LO) and acrylic ester (HyTemp 4454) as binders. Both binders successfully cross-linked with TEGDGE in the presence of RDX and PETN, but only PETN was found to be chemically compatible with the cross-linked polymers. These results show that TEGDGE is suitable as a replacement for toxic isocyanates for the cross-linking of hydroxyl-terminated polyols

Sífilis congênita e recusa terapêutica da gestante: análise jurídica e bioética

Resumo A infecção congênita pela sífilis é uma doença que, apesar dos esforços públicos, ainda se mantém na rotina do sistema de saúde. Embora haja métodos de prevenção efetivos e muito disseminados, tratamento com alto custo-benefício e disponível no Sistema Único de Saúde, além de assistência pré-natal com alta cobertura, as taxas epidemiológicas da enfermidade continuam relevantes e preocupantes. Umas das barreiras à erradicação desse cenário é a recusa terapêutica da genitora. Com isso, indagações importantes são levantadas, como a responsabilidade médica em relação à recusa, a responsabilidade da gestante para com o nascituro e as implicações jurídicas que perpassam essa problemática. O propósito deste artigo é responder a essas questões e suas repercussões bioéticas e jurídicas

Primary alkylphosphine–borane polymers: Synthesis, low glass transition temperature, and a predictive capability thereof

With a multitude of potential applications, poly(phosphine–borane)s are an interesting class of polymer comprising main-group elements within the inorganic polymer backbone. A new family of primary alkylphosphine–borane polymers was synthesized by a solvent-free rhodium-catalyzed dehydrocoupling reaction and characterized by conventional chemicophysical techniques. The thermal stability of the polymers is strongly affected by the size and shape of the alkyl side chain with longer substituents imparting greater stability. The polymers show substantial stability toward UV illumination and immersion in water; however, they undergo a loss of alkylphosphine units during thermal degradation. The polymers exhibit glass transition temperatures (Tg) as low as −70 °C. A group interaction model (GIM) framework was developed to allow the semiquantitative prediction of Tg values, and the properties of the materials in this study were used to validate the model

Pencil it in: pencil drawn electrochemical sensing platforms.

Inspired by recent reports concerning the utilisation of hand drawn pencil macroelectrodes (PDEs), we report the fabrication, characterisation (physicochemical and electrochemical) and implementation (electrochemical sensing) of various PDEs drawn upon a flexible polyester substrate. Electrochemical characterisation reveals that there are no quantifiable electrochemical responses upon utilising these PDEs with an electroactive analyte that requires an electrochemical oxidation step first, therefore the PDEs have been examined towards the electroactive redox probes hexaammineruthenium(iii) chloride, potassium ferricyanide and ammonium iron(ii) sulfate. For the first time, characterisation of the number of drawn pencil layers and the grade of pencil are examined; these parameters are commonly overlooked when utilising PDEs. It is demonstrated that a PDE drawn ten times with a 6B pencil presented the most advantageous electrochemical platform, in terms of electrochemical reversibility and peak height/analytical signal. In consideration of the aforementioned limitation, analytes requiring an electrochemical reduction as the first process were solely analysed. We demonstrate the beneficial electroanalytical capabilities of these PDEs towards p-benzoquinone and the simultaneous detection of heavy metals, namely lead(ii) and cadmium(ii), all of which are explored for the first time utilising PDEs. Initially, the detection limits of this system were higher than desired for electroanalytical platforms, however upon implementation of the PDEs in a back-to-back configuration (in which two PDEs are placed back-to-back sharing a single connection to the potentiostat), the detection limits for lead(ii) and cadmium(ii) correspond to 10 μg L(-1) and 98 μg L(-1) respectively within model aqueous (0.1 M HCl) solutions

Aberrant survival of hippocampal Cajal-Retzius cells leads to memory deficits, gamma rhythmopathies and susceptibility to seizures in adult mice

Cajal-Retzius cells (CRs) are transient neurons, disappearing almost completely in the postnatal neocortex by programmed cell death (PCD), with a percentage surviving up to adulthood in the hippocampus. Here, we evaluate CR’s role in the establishment of adult neuronal and cognitive function using a mouse model preventing Bax-dependent PCD. CRs abnormal survival resulted in impairment of hippocampus-dependent memory, associated in vivo with attenuated theta oscillations and enhanced gamma activity in the dorsal CA1. At the cellular level, we observed transient changes in the number of NPY cells and altered CA1 pyramidal cell spine density. At the synaptic level, these changes translated into enhanced inhibitory currents in hippocampal pyramidal cells. Finally, adult mutants displayed an increased susceptibility to lethal tonic-clonic seizures in a kainate model of epilepsy. Our data reveal that aberrant survival of a small proportion of postnatal hippocampal CRs results in cognitive deficits and epilepsy-prone phenotypes in adulthood.We thank Dr. P. Billuart for critical reading of the manuscript and suggestions during the course of the study, the NeuroImag platform at the IPNP and SFR Necker Imaging and histology platforms at the Imagine Institute for help with acquisition, the animal house facility (LEAT) and Animalliance for animal care. We are grateful to N. Ramezanidoraki and P. Billuart for initiating the first MEA experiment as well as members of the Pierani’s lab for technical support and helpful discussions.We thank Ann Kennedy for mouse profile (Zenodo, 2020) doi:10.5281/zenodo.3925921and for the mouse scheme in Fig. 3a, French Ministry of Research (BioSPc Doctoral school) (M.R.), Fondation pour la recherche médicale, FDT20201201037 (M.R.), Centre national de la recherche scientifique (CNRS) (A.P.), Agence Nationale de la Recherche, ANR-15-CE16-0003-01, ANR-19-CE16-0017-03 and ANR20-CE16-0001-01 (A.P.), Fondation pour la recherche médicale, Équipe FRM DEQ20130326521 and EQU201903007836) (A.P.), Agence Nationale de la Recherche under “Investissements d’avenir” program, ANR10-IAHU-01) (Imagine Institute), Fondation pour la recherche médicale (F.O.), AGEMED-INSERM (F.O.), NRJ for Neuroscience (F.O.), European Research Council (Consolidator grant #683154) (N. Rouach), European Research Council (Starting Grant #678250) (N. Rebola), Agence Nationale de la Recherche ANR-21-CE16-0020 and ANR-20-CE16-0009 (N. Rebola), and ANR-21-NEU2-0007-01 Eranet-Neuron ROSSINI project (A.P. and L.M.d.l.P.)

Insight into Elderly ALS Patients in the Emilia Romagna Region: Epidemiological and Clinical Features of Late-Onset ALS in a Prospective, Population-Based Study

Few studies have focused on elderly (>80 years) amyotrophic lateral sclerosis (ALS) patients, who represent a fragile subgroup generally not included in clinical trials and often neglected because they are more difficult to diagnose and manage. We analyzed the clinical and genetic features of very late-onset ALS patients through a prospective, population-based study in the Emilia Romagna Region of Italy. From 2009 to 2019, 222 (13.76%) out of 1613 patients in incident cases were over 80 years old at diagnosis, with a female predominance (F:M = 1.18). Elderly ALS patients represented 12.02% of patients before 2015 and 15.91% from 2015 onwards (p = 0.024). This group presented with bulbar onset in 38.29% of cases and had worse clinical conditions at diagnosis compared to younger patients, with a lower average BMI (23.12 vs. 24.57 Kg/m2), a higher progression rate (1.43 vs. 0.95 points/month), and a shorter length of survival (a median of 20.77 vs. 36 months). For this subgroup, genetic analyses have seldom been carried out (25% vs. 39.11%) and are generally negative. Finally, elderly patients underwent less frequent nutritional- and respiratory-supporting procedures, and multidisciplinary teams were less involved at follow-up, except for specialist palliative care. The genotypic and phenotypic features of elderly ALS patients could help identify the different environmental and genetic risk factors that determine the age at which disease onset occurs. Since multidisciplinary management can improve a patient’s prognosis, it should be more extensively applied to this fragile group of patients

Qualidade física e sanitária de sementes de Zea mays L. colhidas por colhedoras radiais

Este trabalho foi desenvolvido com o objetivo de avaliar a qualidade física e sanitária de sementes de milho em duas colhedoras operando em velocidades distintas e em amostras coletadas em diferentes locais na máquina. Utilizou-se um esquema fatorial 2x2x2, delineamento inteiramente casualizado com quatro repetições. Os tratamentos foram constituídos por duas colhedoras (New Holland TC 57 e New Holland TC 59), operando em duas velocidades (4 km h-1 e 5 km h-1) e dois locais de coleta das amostras (entrada do tanque graneleiro e saída do tubo de descarga). Para todos os tratamentos avaliou-se: pureza, porcentagem de sementes quebradas, danificadas e a presença de fungos associados às sementes. Houve interação significativa entre os fatores, apenas na obtenção das médias de sementes puras. Constatou-se, principalmente, a presença de Fusarium sp., Cladosporium sp., Aspergillus spp. e Penicillium sp. Menores perdas foram observadas quando se utilizou a colhedora TC 57 à velocidade de 4 km h-1. Não houve diferença entre velocidades para perdas qualitativas de sementes colhidas pela colhedora TC 59. Sementes colhidas pelas duas colhedoras e nas duas velocidades testadas apresentaram diferenças quanto à presença de fungos, mostrando maior incidência nas sementes coletadas na saída do tubo de descarga. Este trabajo fue desarrollado con el objetivo de evaluar la calidad física y sanitaria de semillas de maíz en dos cosechadoras operando a velocidades distintas y en muestras recolectadas de diferentes lugares en la máquina. Se utilizó un diseño factorial 2x2x2, delineamiento enteramente casualizado con cuatro repeticiones. Los tratamientos fueron constituidos por dos cosechadoras (New Holland TC 57 y New Holland TC 59), operando en dos velocidades (4 km.h-1 y 5 km.h-1) y dos lugares de recolección de las muestras (entrada del tanque granelero y salida del tubo de descarga). Para todos los tratamientos se evaluó: pureza, porcentaje de semillas quebradas, dañadas y la presencia de hongos asociados a las semillas. Hubo interacción significativa entre los factores sólo en la obtención de los promedios de semillas puras. Se constató, principalmente, la presencia de Fusarium sp., Cladosporium sp., Aspergillus spp. y Penicillium sp. Menores pérdidas fueron observadas cuando se utilizó la cosechadora TC 57 a una velocidad de 4 km.h-1. No hubo diferencias entre velocidades para pérdidas cualitativas de semillas recolectadas por la cosechadora TC 59. Semillas recolectadas por ambas cosechadoras y en las dos velocidades presentaron diferencias en presencia de hongos, mostrando mayor incidencia en las semillas cosechadas en la salida del tubo de descarga