Sporadic Infantile Epileptic Encephalopathy Caused by Mutations in PCDH19 Resembles Dravet Syndrome but Mainly Affects Females

Dravet syndrome (DS) is a genetically determined epileptic encephalopathy mainly caused by de novo mutations in the SCN1A gene. Since 2003, we have performed molecular analyses in a large series of patients with DS, 27% of whom were negative for mutations or rearrangements in SCN1A. In order to identify new genes responsible for the disorder in the SCN1A-negative patients, 41 probands were screened for micro-rearrangements with Illumina high-density SNP microarrays. A hemizygous deletion on chromosome Xq22.1, encompassing the PCDH19 gene, was found in one male patient. To confirm that PCDH19 is responsible for a Dravet-like syndrome, we sequenced its coding region in 73 additional SCN1A-negative patients. Nine different point mutations (four missense and five truncating mutations) were identified in 11 unrelated female patients. In addition, we demonstrated that the fibroblasts of our male patient were mosaic for the PCDH19 deletion. Patients with PCDH19 and SCN1A mutations had very similar clinical features including the association of early febrile and afebrile seizures, seizures occurring in clusters, developmental and language delays, behavioural disturbances, and cognitive regression. There were, however, slight but constant differences in the evolution of the patients, including fewer polymorphic seizures (in particular rare myoclonic jerks and atypical absences) in those with PCDH19 mutations. These results suggest that PCDH19 plays a major role in epileptic encephalopathies, with a clinical spectrum overlapping that of DS. This disorder mainly affects females. The identification of an affected mosaic male strongly supports the hypothesis that cellular interference is the pathogenic mechanism

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Structural, biochemical and functional analyses of tRNA-monooxygenase enzyme MiaE from Pseudomonas putida provide insights into tRNA/MiaE interaction

International audienceMiaE (2-methylthio-N6-isopentenyl-adenosine37-tRNA monooxygenase) is a unique non-heme diiron enzyme that catalyzes the O2-dependent post-transcriptional allylic hydroxylation of a hypermodified nucleotide 2-methylthio-N6-isopentenyl-adenosine (ms2i6A37) at position 37 of selected tRNA molecules to produce 2-methylthio-N6–4-hydroxyisopentenyl-adenosine (ms2io6A37). Here, we report the in vivo activity, biochemical, spectroscopic characterization and X-ray crystal structure of MiaE from Pseudomonas putida. The investigation demonstrates that the putative pp-2188 gene encodes a MiaE enzyme. The structure shows that Pp-MiaE consists of a catalytic diiron(III) domain with a four alpha-helix bundle fold. A docking model of Pp-MiaE in complex with tRNA, combined with site directed mutagenesis and in vivo activity shed light on the importance of an additional linker region for substrate tRNA recognition. Finally, krypton-pressurized Pp-MiaE experiments, revealed the presence of defined O2 site along a conserved hydrophobic tunnel leading to the diiron active center

Discovery and characterization of auxiliary proteins encoded by type 3 Simian T-cell Lymphotropic Viruses

International audienceHuman T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 encode auxiliary proteins that play important roles in viral replication, viral latency, and immune escape. The presence of auxiliary protein-encoding open reading frames (ORFs) in HTLV-3, the latest HTLV to be discovered, is unknown. Simian T-cell lymphotropic virus type 3 (STLV-3) is almost identical to HTLV-3. Given the lack of HTLV-3-infected cell lines, we took advantage of STLV-3-infected cells and of an STLV-3 molecular clone to search for the presence of auxiliary transcripts. Using reverse transcriptase PCR (RT-PCR), we first uncovered the presence of three unknown viral mRNAs encoding putative proteins of 5, 8, and 9 kDa and confirmed the presence of the previously reported RorfII transcript. The existence of these viral mRNAs was confirmed by using splice site-specific RT-PCR with ex vivo samples. We showed that p5 is distributed throughout the cell and does not colocalize with a specific organelle. The p9 localization is similar to that of HTLV-1 p12 and induced a strong decrease in the calreticulin signal, similarly to HTLV-1 p12. Although p8, RorfII, and Rex-3 share an N-terminal sequence that is predicted to contain a nucleolar localization signal (NoLS), only p8 is found in the nucleolus. The p8 location in the nucleolus is linked to a bipartite NoLS. p8 and, to a lesser extent, p9 repressed viral expression but did not alter Rex-3-dependent mRNA export. Using a transformation assay, we finally showed that none of the STLV-3 auxiliary proteins had the ability to induce colony formation, while both Tax-3 and antisense protein of HTLV-3 (APH-3) promoted cellular transformation. Altogether, these results complete the characterization of the newly described primate T-lymphotropic virus type 3 (PTLV-3). IMPORTANCE: Together with their simian counterparts, HTLVs form the primate T-lymphotropic viruses. HTLVs arose from interspecies transmission between nonhuman primates and humans. HTLV-1 and HTLV-2 encode auxiliary proteins that play important roles in viral replication, viral latency, and immune escape. The presence of ORFs encoding auxiliary proteins in HTLV-3 or STLV-3 genomes was unknown. Using in silico analyses, ex vivo samples, or in vitro experiments, we have uncovered the presence of 3 previously unknown viral mRNAs encoding putative proteins and confirmed the presence of a previously reported viral transcript. We characterized the intracellular localization of the four proteins. We showed that two of these proteins repress viral expression but that none of them have the ability to induce colony formation. However, both Tax and the antisense protein APH-3 promote cell transformation. Our results allowed us to characterize 4 new retroviral proteins for the first time

Immunomodulatory drugs in multiple myeloma: Impact of the SCARMET (Self CARe and MEdication Toxicity) educational intervention on outpatients' knowledge to manage adverse effects.

Long-term multiple myeloma therapy by immunomodulatory drugs (IMiDs) raises the question of management of adverse effects. The aim of this study is to assess the impact of an educational session for patients on the acquisition of knowledge to manage hematologic and thromboembolic adverse effects of IMiDs. In this prospective single-center study, patients attended an educational session with a hospital clinical pharmacist and a nurse. The primary endpoint was the patient's level of knowledge for the management of IMiDs adverse effects, assess with a dedicated questionnaire administered before the session then 1 and 6 months after. Assessment of knowledge was combined with self-assessment of certainty. The secondary endpoints were adherence and IMiD treatment satisfaction. 50 patients were included. Patient knowledge increased at 1 month (p<0.001) despite a loss of knowledge at 6 months (p<0.05). Six months after the educational intervention, the number of patients with skills considered satisfactory by the pharmacist and nurse increased (p<0.01). Most patients showed satisfactory adherence, with medication possession ratio ≥ 80%. The Self CARe and MEdication Toxicity (SCARMET) study highlighted the impact of multidisciplinary follow-up in multiple myeloma patients to improve knowledge of toxicity self-management

De l’agglomération antique de <i>Cassinomagus</i> au village de Chassenon (Charente) : un bilan des connaissances

International audienceThis article represents an opportunity to draft a developed and detailed assessment of the major advances in knowledge, provided by the last eight years of research, and pertaining to the Cassinomagus agglomeration. Indeed, two successive Collective Research Projects (CRP) have deepened, and in some cases even renewed, our understanding of this site whose occupation would appear to be attested to the Second Iron Age onward. A diachronic study, which implements both a global and interdisciplinary approach, allowed us to confront the question of the evolution of the urban structuring of this ancient site. A functional organization of the site’s various neighborhoods around a well-established road network, including a densification of habitat and a diversification of artisanal activities emerged during the 1st c. AD. The peak of its monumentalization during the 2nd c. AD –accompanied by a reorganization of the urban fabric– allowed us to question more broadly the role of urban concentration in the structuring of community in the Lemovices civitas. Beginning in the 3rd c. AD, the site subsequently experienced a gradual decline, though consideration of the impact of its location near the border endured thanks to historical research carried out within the parish of Chassenon.Cet article est l’occasion de dresser un bilan développé et détaillé des principaux acquis sur l’agglomération de Cassinomagus, issus des huit dernières années de recherches. Deux projets collectifs de recherche (PCR) successifs ont en effet conduit à approfondir, voire, dans certains cas, à renouveler les connaissances sur ce site dont la fréquentation semble être attestée dès le second âge du Fer. Une étude diachronique, qui met en œuvre une approche tant globale qu’interdisciplinaire, permet d’aborder l’évolution de la structuration urbaine du site antique. Une organisation fonctionnelle des quartiers, autour d’un réseau viaire bien établi, se dessine ainsi pendant le Ier s. apr. J.-C., avec une densification de l’habitat et une diversification des activités artisanales. Le temps fort que représente sa monumentalisation au IIe s. apr. J.-C. – s’accompagnant d’une réorganisation du tissu urbain – permet plus largement d’interroger la place de l’agglomération dans la structuration communautaire de la cité des Lémovices. L’agglomération connaît ensuite une lente désaffection amorcée dès le IIIe s. apr. J.-C., mais la réflexion sur les effets de sa position frontalière se poursuit grâce aux recherches historiques menées sur la paroisse de Chassenon