Lipopolysaccharide biosynthesis and traffic in the envelope of the pathogen Brucella abortus.

Lipopolysaccharide is essential for most Gram-negative bacteria as it is a main component of the outer membrane. In the pathogen Brucella abortus, smooth lipopolysaccharide containing the O-antigen is required for virulence. Being part of the Rhizobiales, Brucella spp.

Histidine auxotroph mutant is defective for cell separation and allows the identification of crucial factors for cell division in Brucella abortus.

The pathogenic bacterium Brucella abortus invades and multiplies inside host cells. To grow inside host cells, B. abortus requires a functional histidine biosynthesis pathway.

Early Corticosteroid Therapy May Increase Ventilator-Associated Lower Respiratory Tract Infection in Critically Ill Patients with COVID-19: A Multicenter Retrospective Cohort Study.

Background: The coronavirus disease 2019 (COVID-19) pandemic has put significant pressure on hospitals and in particular on intensive care units (ICU). Some patients develop acute hypoxemic respiratory failure with profound hypoxia, which likely requires invasive mechanical ventilation during prolonged periods. Corticosteroids have become a cornerstone therapy for patients with severe COVID-19, though only little data are available regarding their potential harms and benefits, especially concerning the risk of a ventilator-associated lower respiratory tract infection (VA-LRTI).

PdeA is required for the rod shape morphology of Brucella abortus.

Cyclic-di-GMP plays crucial role in the cell cycle regulation of the α-Proteobacterium Caulobacter crescentus. Here we investigated its role in the α-Proteobacterium Brucella abortus, a zoonotic intracellular pathogen. Surprisingly, deletion of all predicted cyclic-di-GMP synthesizing or degrading enzymes did not drastically impair the growth of B.

Aconitate decarboxylase 1 participates in the control of pulmonary Brucella infection in mice.

Brucellosis is one of the most widespread bacterial zoonoses worldwide. Here, our aim was to identify the effector mechanisms controlling the early stages of intranasal infection with Brucella in C57BL/6 mice. During the first 48 hours of infection, alveolar macrophages (AMs) are the main cells infected in the lungs.

Development of mAb-loaded 3D-printed (FDM) implantable devices based on PLGA.

The main objective of this work was to explore the feasibility to print monoclonal antibody (mAb)-loaded implantable systems using fused-deposition modelling (FDM) to build complex dosage form designs. Indeed, to our knowledge, this work is the first investigation of mAb-loaded devices using FDM. To make this possible, different steps were developed and optimized.

Intracellular Growth and Cell Cycle Progression are Dependent on (p)ppGpp Synthetase/Hydrolase in .

is a pathogenic bacterium able to proliferate inside host cells. During the first steps of its trafficking, it is able to block the progression of its cell cycle, remaining at the G1 stage for several hours, before it reaches its replication niche. We hypothesized that starvation mediated by guanosine tetra- or penta-phosphate, (p)ppGpp, could be involved in the cell cycle arrest.

Feasibility study into the potential use of fused-deposition modeling to manufacture 3D-printed enteric capsules in compounding pharmacies.

The purpose of this work was to investigate the feasibility to manufacture enteric capsules, which could be used in compounding pharmacies, by fused-deposition modeling. It is well-known that conventional enteric dip coating of capsules in community pharmacies or hospitals is a time-consuming process which is characterized by an erratic efficacy. Fused-deposition modeling was selected as a potential 3D printing method due its ease and low-cost implementation.

Investigation of the parameters used in fused deposition modeling of poly(lactic acid) to optimize 3D printing sessions.

This study assesses the feasibility of printing implantable devices using 3D printing Fused deposition modeling (FDM) technology. The influence of the deposition temperature, the deposition rate and the layer thickness on the printing process and the physical properties of the devices were evaluated. The filaments were composed of neat poly(lactic acid) (PLA) and blends of different plasticizers (polyethylene glycol 400 (PEG 400), triacetine (TA), acetyltriethyl citrate (ATEC) and triethyl citrate (TEC)) at 10% (w/w).

Capnocytophaga canimorsus Capsular Serovar and Disease Severity, Helsinki Hospital District, Finland, 2000-2017.

We assembled a collection of 73 Capnocytophaga canimorsus isolates obtained from blood cultures taken from patients treated at Helsinki University Hospital (Helsinki, Finland) during 2000-2017. We serotyped these isolates by PCR and Western blot and attempted to correlate pathogen serovar with patient characteristics. Our analyses showed, in agreement with previous research, that 3 C.

Capsular serovars of virulent Capnocytophaga canimorsus are shared by the closely related species C. canis and C. cynodegmi.

Capnocytophaga canimorsus is a dog oral commensal bacterium that causes rare but life-threatening generalized infections in humans who have been in contact with its animal hosts. Two other dog commensals, Capnocytophaga canis and Capnocytophaga cynodegmi, cause rare, mild local infections. To date, nine capsular serovars have been described in C.

Breakdown of foster care placements in Flanders: incidence and associated factors.

In Flanders, family foster care is increasingly the option of choice for children in need of out-of-home care. Foster care is however an assailable intervention as is shown by the high number of placement disruptions. Knowledge regarding breakdown in Flanders remains scant.

Distribution of Sulfate-Reducing Communities from Estuarine to Marine Bay Waters.

Estuaries are highly dynamic ecosystems in which freshwater and seawater mix together. Depending on tide and river inflows, particles originating from rivers or from the remobilization of sediments accumulate in the water column. Due to the salinity gradient and the high heterotrophic activity in the estuarine plume, hypoxic and anoxic microniches may form in oxygenated waters, sustaining favorable conditions for resuspended anaerobic microorganisms.

Presynaptic hyperpolarization induces a fast analogue modulation of spike-evoked transmission mediated by axonal sodium channels.

In the mammalian brain, synaptic transmission usually depends on presynaptic action potentials (APs) in an all-or-none (or digital) manner. Recent studies suggest, however, that subthreshold depolarization in the presynaptic cell facilitates spike-evoked transmission, thus creating an analogue modulation of a digital process (or analogue-digital (AD) modulation). At most synapses, this process is slow and not ideally suited for the fast dynamics of neural networks.

Analog modulation of spike-evoked transmission in CA3 circuits is determined by axonal Kv1.1 channels in a time-dependent manner.

Synaptic transmission usually depends on action potentials (APs) in an all-or-none (digital) fashion. Recent studies indicate, however, that subthreshold presynaptic depolarization may facilitate spike-evoked transmission, thus creating an analog modulation of spike-evoked synaptic transmission, also called analog-digital (AD) synaptic facilitation. Yet, the underlying mechanisms behind this facilitation remain unclear.

AaTX1, from Androctonus australis scorpion venom: purification, synthesis and characterization in dopaminergic neurons.

We have purified the AaTX1 peptide from the Androctonus australis (Aa) scorpion venom, previously cloned and sequenced by Legros and collaborators in a venom gland cDNA library from Aa scorpion. AaTX1 belongs to the α-Ktx15 scorpion toxins family (αKTx15-4). Characterized members of this family share high sequence similarity and were found to block preferentially IA-type voltage-dependent K(+) currents in rat cerebellum granular cells in an irreversible way.

ATP-P2X7 Receptor Modulates Axon Initial Segment Composition and Function in Physiological Conditions and Brain Injury.

Axon properties, including action potential initiation and modulation, depend on both AIS integrity and the regulation of ion channel expression in the AIS. Alteration of the axon initial segment (AIS) has been implicated in neurodegenerative, psychiatric, and brain trauma diseases, thus identification of the physiological mechanisms that regulate the AIS is required to understand and circumvent AIS alterations in pathological conditions. Here, we show that the purinergic P2X7 receptor and its agonist, adenosine triphosphate (ATP), modulate both structural proteins and ion channel density at the AIS in cultured neurons and brain slices.

GSK3 and β-catenin determines functional expression of sodium channels at the axon initial segment.

Neuronal action potentials are generated through voltage-gated sodium channels, which are tethered by ankyrinG at the membrane of the axon initial segment (AIS). Despite the importance of the AIS in the control of neuronal excitability, the cellular and molecular mechanisms regulating sodium channel expression at the AIS remain elusive. Our results show that GSK3α/β and β-catenin phosphorylated by GSK3 (S33/37/T41) are localized at the AIS and are new components of this essential neuronal domain.

Calmodulin and calcium differentially regulate the neuronal Nav1.1 voltage-dependent sodium channel.

Mutations in the neuronal Nav1.1 voltage-gated sodium channel are responsible for mild to severe epileptic syndromes. The ubiquitous calcium sensor calmodulin (CaM) bound to rat brain Nav1.

The role of hyperpolarization-activated cationic current in spike-time precision and intrinsic resonance in cortical neurons in vitro.

Hyperpolarization-activated cyclic nucleotide modulated current (I(h)) sets resonance frequency within the θ-range (5–12 Hz) in pyramidal neurons. However, its precise contribution to the temporal fidelity of spike generation in response to stimulation of excitatory or inhibitory synapses remains unclear. In conditions where pharmacological blockade of I(h) does not affect synaptic transmission, we show that postsynaptic h-channels improve spike time precision in CA1 pyramidal neurons through two main mechanisms.

Axon physiology.

Axons are generally considered as reliable transmission cables in which stable propagation occurs once an action potential is generated. Axon dysfunction occupies a central position in many inherited and acquired neurological disorders that affect both peripheral and central neurons. Recent findings suggest that the functional and computational repertoire of the axon is much richer than traditionally thought.

Characterization of rhizosphere bacteria for control of phytopathogenic fungi of tomato.

Fluorescent Pseudomonas spp., isolated from rhizosphere soil of tomato and pepper plants, were evaluated in vitro as potential antagonists of fungal pathogens. Strains were characterized using the API 20NE biochemical system, and tested against the causal agents of stem canker and leaf blight (Alternaria alternata f.

[Thrombocytopenia and acute kidney injury].

A 31-year old man is addressed to the emergency department for fever, abdominal pain and vomiting. Laboratory tests reveal an inflammatory syndrome, thrombocytopenia, acute kidney injury associated with major proteinuria (more than 3 g/24 h). Evaluation will conclude to an acute interstitial nephritis and the serology is positive for Hantavirus.