Serotonin signaling regulates actomyosin contractility during morphogenesis in evolutionarily divergent lineages.

Serotonin is a neurotransmitter that signals through 5-HT receptors to control key functions in the nervous system. Serotonin receptors are also ubiquitously expressed in various organs and have been detected in embryos of different organisms. Potential morphogenetic functions of serotonin signaling have been proposed based on pharmacological studies but a mechanistic understanding is still lacking.

Experiences of Inter-Hospital Transfers (IHT) by Patients and Relatives during the COVID-19 Pandemic in France: A Qualitative Study.

Background: The first wave of the COVID-19 epidemic led to a rapid and unexpected saturation of the French ICU, forcing the health care system to adapt. Among other emergency measures, inter-hospital transfers were carried out.

Objective: To assess the psychological experience of patients and their relatives regarding inter-hospital transfers.

Impact of ICU transfers on the mortality rate of patients with COVID-19: insights from comprehensive national database in France.

Background: The first wave of the COVID-19 pandemic confronted healthcare systems around the world with unprecedented organizational challenges, particularly regarding the availability of intensive care unit (ICU) beds. One strategy implemented in France to alleviate healthcare pressure during the first COVID-19 wave was inter-hospital transfers of selected ICU patients from overwhelmed areas towards less saturated ones. At the time, the impact of this transfer strategy on patient mortality was unknown.

TRANSCOV cohort protocol: an epidemiological study assessing the impact of critically ill COVID-19 patients long distance transfers between intensive care units.

Introduction: During spring 2020, four regions of France faced a surge of severe COVID-19 patients which threatened to overflow local intensive care units (ICU) capacities. As an emergency response, between 13 March 2020 and 10 April 2020, an estimated 661 patients were transferred from overcrowded ICUs to eight other French regions and four neighbouring countries. The intensity, geographical spread and the diversity of vectors used are unprecedented.

Psychological impact of an acute intervention on medical-psychological emergency unit professionals: the example of hurricane Irma.

Background: Medical-psychological emergency units (Cellules d'Urgence Médico-Psychologiques, CUMP) are deployed following major events where there is a risk of psychological trauma, in order to provide acute and proper psychological care for the victims.

Aims: To describe and evaluate the risk of a psychological impact on CUMP professionals after their participation in the aftermath of the hurricane Irma natural disaster. CUMP teams consist of medical and paramedical staff, who can have permanent or volunteer status.

Formation of polarized contractile interfaces by self-organized Toll-8/Cirl GPCR asymmetry.

Interfaces between cells with distinct genetic identities elicit signals to organize local cell behaviors driving tissue morphogenesis. The Drosophila embryonic axis extension requires planar polarized enrichment of myosin-II powering oriented cell intercalations. Myosin-II levels are quantitatively controlled by GPCR signaling, whereas myosin-II polarity requires patterned expression of several Toll receptors.

An appropriate and reactive response to the repeated waves of the COVID-19 pandemic by the national medico-psychological network (CUMP) in France.

Introduction: France has been impacted by the COVID-19 pandemic. Anxiety, depression, burn out and the high proportion of post-traumatic stress disorder proved to be the most expected troubles caused by this pandemic and the confinement. Medico-psychological emergency units (CUMP) have been solicited at the very early stage of the pandemic because CUMP units are very well known by the French government and systematically associated to emergency plans.

Assembly of a persistent apical actin network by the formin Frl/Fmnl tunes epithelial cell deformability.

Tissue remodelling during Drosophila embryogenesis is notably driven by epithelial cell contractility. This behaviour arises from the Rho1-Rok-induced pulsatile accumulation of non-muscle myosin II pulling on actin filaments of the medioapical cortex. While recent studies have highlighted the mechanisms governing the emergence of Rho1-Rok-myosin II pulsatility, little is known about how F-actin organization influences this process.

Distinct RhoGEFs Activate Apical and Junctional Contractility under Control of G Proteins during Epithelial Morphogenesis.

Small RhoGTPases direct cell shape changes and movements during tissue morphogenesis. Their activities are tightly regulated in space and time to specify the desired pattern of actomyosin contractility that supports tissue morphogenesis. This is expected to stem from polarized surface stimuli and from polarized signaling processing inside cells.

Distinct contributions of tensile and shear stress on E-cadherin levels during morphogenesis.

During epithelial morphogenesis, cell contacts (junctions) are constantly remodeled by mechanical forces that work against adhesive forces. E-cadherin complexes play a pivotal role in this process by providing persistent cell adhesion and by transmitting mechanical tension. In this context, it is unclear how mechanical forces affect E-cadherin adhesion and junction dynamics.

Quantitative Control of GPCR Organization and Signaling by Endocytosis in Epithelial Morphogenesis.

Tissue morphogenesis arises from controlled cell deformations in response to cellular contractility. During Drosophila gastrulation, apical activation of the actomyosin networks drives apical constriction in the invaginating mesoderm and cell-cell intercalation in the extending ectoderm. Myosin II (MyoII) is activated by cell-surface G protein-coupled receptors (GPCRs), such as Smog and Mist, that activate G proteins, the small GTPase Rho1, and the kinase Rok.

Pre-assembled Nuclear Pores Insert into the Nuclear Envelope during Early Development.

Nuclear pore complexes (NPCs) span the nuclear envelope (NE) and mediate nucleocytoplasmic transport. In metazoan oocytes and early embryos, NPCs reside not only within the NE, but also at some endoplasmic reticulum (ER) membrane sheets, termed annulate lamellae (AL). Although a role for AL as NPC storage pools has been discussed, it remains controversial whether and how they contribute to the NPC density at the NE.

French Ministry of Health's response to Paris attacks of 13 November 2015.

On Friday November 13th at 9:20 pm, three kamikaze bombs went off around the Stade de France a stadium in Saint-Denis just outside Paris, 4 different shootings took place and bombings in Paris and hundreds of people were held hostage in a theater.This multi-site terrorist attack was the first of this magnitude in France. Drawing the lessons of these attacks and those which occurred in other countries from a health perspective is essential to continuously adapt and improve the French response to possible future attacks.

Modular activation of Rho1 by GPCR signalling imparts polarized myosin II activation during morphogenesis.

Polarized cell shape changes during tissue morphogenesis arise by controlling the subcellular distribution of myosin II. For instance, during Drosophila melanogaster gastrulation, apical constriction and cell intercalation are mediated by medial-apical myosin II pulses that power deformations, and polarized accumulation of myosin II that stabilizes these deformations. It remains unclear how tissue-specific factors control different patterns of myosin II activation and the ratchet-like myosin II dynamics.

A self-organized biomechanical network drives shape changes during tissue morphogenesis.

Tissue morphogenesis is orchestrated by cell shape changes. Forces required to power these changes are generated by non-muscle myosin II (MyoII) motor proteins pulling filamentous actin (F-actin). Actomyosin networks undergo cycles of assembly and disassembly (pulses) to cause cell deformations alternating with steps of stabilization to result in irreversible shape changes.

A screening tool to prioritize public health risk associated with accidental or deliberate release of chemicals into the atmosphere.

The Chemical Events Working Group of the Global Health Security Initiative has developed a flexible screening tool for chemicals that present a risk when accidentally or deliberately released into the atmosphere. The tool is generic, semi-quantitative, independent of site, situation and scenario, encompasses all chemical hazards (toxicity, flammability and reactivity), and can be easily and quickly implemented by non-subject matter experts using freely available, authoritative information. Public health practitioners and planners can use the screening tool to assist them in directing their activities in each of the five stages of the disaster management cycle.

Spatial control of actin organization at adherens junctions by a synaptotagmin-like protein Btsz.

Epithelial tissues maintain a robust architecture during development. This fundamental property relies on intercellular adhesion through the formation of adherens junctions containing E-cadherin molecules. Localization of E-cadherin is stabilized through a pathway involving the recruitment of actin filaments by E-cadherin.

Developmental control of nuclear morphogenesis and anchoring by charleston, identified in a functional genomic screen of Drosophila cellularisation.

Morphogenesis of epithelial tissues relies on the precise developmental control of cell polarity and architecture. In the early Drosophila embryo, the primary epithelium forms during cellularisation, following a tightly controlled genetic programme where specific sets of genes are upregulated. Some of them, for example, control membrane invagination between the nuclei anchored at the apical surface of the syncytium.

Specific sorting of the a1 isoform of the V-H+ATPase a subunit to nerve terminals where it associates with both synaptic vesicles and the presynaptic plasma membrane.

Vacuolar H+ATPase (V-ATPase) accumulates protons inside various intracellular organelles, generating the electrochemical proton gradient required for many vital cellular processes. V-ATPase is a complex enzyme with many subunits that are organized into two domains. The membrane domain that translocates protons contains a proteolipid oligomer of several c subunits and a 100 kDa a subunit.

Functional expression of V-ATPases in the plasma membrane of glial cells.

Vacuolar H(+) ATPase (V-ATPase) activity is essential for many cellular processes, including intracellular membrane traffic, protein processing and degradation, and receptor-mediated endocytosis. Proton transport by V-ATPases could also play a role during cell transformation, tumorigenesis, and cell metastasis, and V-ATPase c-subunit overexpression was reported to be correlated with invasiveness of pancreatic tumors (Ohta et al., 1996).