Dents, implants, et pathologies sinusiennes, stratégies de prise en charge : travail préliminaire pour l'établissement de bonnes pratiques cliniques

Introduction : Les pathologies sinusiennes d’origine dentaire représentent un motif de consultation très fréquent ; 40% des sinusites maxillaires chroniques sont d’origine dentaire. L’essor actuel de l’implantologie et de la chirurgie pré-implantaire confronte le médecin otorhinolaryngologiste à de nouvelles situations cliniques. À l’heure actuelle, aucune recommandation n’a été mise en place dans ce domaine. Les objectifs de ce travail étaient de proposer une classification des pathologies sinusiennes d’origine dentaire et d’établir une stratégie de prise en charge diagnostique et thérapeutique spécifique.<br>Matériel et méthode : Il s’agit d’une étude longitudinale observationnelle portant sur une série de patients présentant une pathologie sinusienne liée aux dents ou aux implants, menée de janvier 2012 à août 2014, au Centre Hospitalier et Universitaire de Nice. Les patients ont été pris en charge soit dans le service d’ORL, soit dans le service d’odontologie de l’hôpital Saint Roch. L’ensemble des patients inclus a permis d’établir une base de données. À partir de celle-ci, nous avons choisi d’illustrer un cas par type de pathologie sinusienne d’origine dentaire. Les cas sélectionnés étaient ceux qui présentaient le tableau clinique et paraclinique le plus typique de la pathologie pour illustrer au mieux leur prise en charge dans notre service.<br>Résultats : 118 dossiers ont été étudiés ; 60 ont été inclus et ont constitué notre base de données. Dans cette dernière, 34 cas cliniques ont été sélectionnés. Nous avons proposé une classification des pathologies sinusiennes liées aux dents et une stratégie de prise en charge diagnostique et thérapeutique adaptée. Nous avons comparé notre prise en charge à celle de la littérature.<br>Conclusion : Ce travail préliminaire soulève certaines questions et constate le manque de recommandations. Il pourrait servir à l’ébauche de nouvelles recommandations de bonnes pratiques cliniques au moyen d’études prospectives bien menées

Conserved presence of G-quadruplex forming sequences in the Long Terminal Repeat Promoter of Lentiviruses

G-quadruplexes (G4s) are secondary structures of nucleic acids that epigenetically regulate cellular processes. In the human immunodeficiency lentivirus 1 (HIV-1), dynamic G4s are located in the unique viral LTR promoter. Folding of HIV-1 LTR G4s inhibits viral transcription; stabilization by G4 ligands intensifies this effect. Cellular proteins modulate viral transcription by inducing/unfolding LTR G4s. We here expanded our investigation on the presence of LTR G4s to all lentiviruses. G4s in the 5'-LTR U3 region were completely conserved in primate lentiviruses. A G4 was also present in a cattle-infecting lentivirus. All other non-primate lentiviruses displayed hints of less stable G4s. In primate lentiviruses, the possibility to fold into G4s was highly conserved among strains. LTR G4 sequences were very similar among phylogenetically related primate viruses, while they increasingly differed in viruses that diverged early from a common ancestor. A strong correlation between primate lentivirus LTR G4s and Sp1/NF\u3baB binding sites was found. All LTR G4s folded: their complexity was assessed by polymerase stop assay. Our data support a role of the lentiviruses 5'-LTR G4 region as control centre of viral transcription, where folding/unfolding of G4s and multiple recruitment of factors based on both sequence and structure may take place

Absence of Resistance Mutations in the Integrase Coding Region among ART-Experienced Patients in the Republic of the Congo

Background: HIV infects around one hundred thousand patients in the Republic of the Congo. Approximately 25% of them receive an antiretroviral treatment; current first-line regimens include two NRTIs and one NNRTI, reverse transcriptase inhibitors. Recently, protease inhibitors (PIs) were also introduced as second-line therapy upon clinical signs of treatment failure. Due to the limited number of molecular characterizations and amount of drug resistance data available in the Republic of the Congo, this study aims to evaluate the prevalence of circulating resistance mutations within the pol region. Methods: HIV-positive, ART-experienced patients have been enrolled in four semi-urban localities in the Republic of the Congo. Plasma samples were collected, and viral RNA was extracted. The viral load for each patient was evaluated by RT-qPCR, following the general diagnostic procedures of the University Hospital of Bordeaux. Finally, drug resistance genotyping and phylogenetic analysis were conducted following Sanger sequencing of the pol region. Results: A high diversity of HIV-1 strains was observed with many recombinant forms. Drug resistance mutations in RT and PR genes were determined and correlated to HAART. Because integrase inhibitors are rarely included in treatments in the Republic of the Congo, the prevalence of integrase drug resistance mutations before treatment was also determined. Interestingly, very few mutations were observed. Conclusions: We confirmed a high diversity of HIV-1 in the Republic of the Congo. Most patients presented an accumulation of mutations conferring resistance against NRTIs, NNRTIs and PIs. Nonetheless, the absence of integrase mutations associated with drug resistance suggests that the introduction of integrase inhibitors into therapy will be highly beneficial to patients in the Republic of the Congo

Potential antiviral effects of pantethine against SARS-CoV-2

Abstract SARS-CoV-2 interacts with cellular cholesterol during many stages of its replication cycle. Pantethine was reported to reduce total cholesterol levels and fatty acid synthesis and potentially alter different processes that might be involved in the SARS-CoV-2 replication cycle. Here, we explored the potential antiviral effects of pantethine in two in vitro experimental models of SARS-CoV-2 infection.Pantethine reduced the infection of cells by SARS-CoV-2 in both preinfection and postinfection treatment regimens. Accordingly, cellular expression of the viral spike and nucleocapsid proteins was substantially reduced, and we observed a significant reduction in viral copy numbers in the supernatant of cells treated with pantethine. In addition, pantethine inhibited the infection-induced increase in TMPRSS2 and HECT E3 ligase expression in infected cells as well as the increase in antiviral interferon-beta response and inflammatory gene expression in Calu-3a cells. Our results demonstrate that pantethine, which is well tolerated in humans, was very effective in controlling SARS-CoV-2 infection and might represent a new therapeutic drug that can be repurposed for the prevention or treatment of COVID-19 and long COVID syndrome

Unprocessed Viral DNA Could Be the Primary Target of the HIV-1 Integrase Inhibitor Raltegravir

Integration of HIV DNA into host chromosome requires a 3′-processing (3′-P) and a strand transfer (ST) reactions catalyzed by virus integrase (IN). Raltegravir (RAL), commonly used in AIDS therapy, belongs to the family of IN ST inhibitors (INSTIs) acting on IN-viral DNA complexes (intasomes). However, studies show that RAL fails to bind IN alone, but nothing has been reported on the behaviour of RAL toward free viral DNA. Here, we assessed whether free viral DNA could be a primary target for RAL, assuming that the DNA molecule is a receptor for a huge number of pharmacological agents. Optical spectroscopy, molecular dynamics and free energy calculations, showed that RAL is a tight binder of both processed and unprocessed LTR (long terminal repeat) ends. Complex formation involved mainly van der Waals forces and was enthalpy driven. Dissociation constants (Kds) revealed that RAL affinity for unbound LTRs was stronger than for bound LTRs. Moreover, Kd value for binding of RAL to LTRs and IC50 value (half concentration for inhibition) were in same range, suggesting that RAL binding to DNA and ST inhibition are correlated events. Accommodation of RAL into terminal base-pairs of unprocessed LTR is facilitated by an extensive end fraying that lowers the RAL binding energy barrier. The RAL binding entails a weak damping of fraying and correlatively of 3′-P inhibition. Noteworthy, present calculated RAL structures bound to free viral DNA resemble those found in RAL-intasome crystals, especially concerning the contacts between the fluorobenzyl group and the conserved 5′C4pA33′ step. We propose that RAL inhibits IN, in binding first unprocessed DNA. Similarly to anticancer drug poisons acting on topoisomerases, its interaction with DNA does not alter the cut, but blocks the subsequent joining reaction. We also speculate that INSTIs having viral DNA rather IN as main target could induce less resistance

Etude de l'intégrase de VIH-1 et du 93del (à la recherche de nouveaux inhibiteurs dans la lutte contre le SIDA)

Le virus de l'immunodéficience humaine de type 1 est un virus infection responsable d'une pandémie incurable. Les traitements actuels permettent, malgré des effets secondaires importants, de contenir la maladie associée, le SIDA. Nous avons développé au laboratoire une stratégie combinatoire (SELEX) dans le but d'isoler de petits ODN présentant une haute affinité pour la RNase H. Gardant en tête que le domaine RNase H et le core catalytique de l'IN soont structuralement proches, ces aptamères ont été testés pour leur capacité à inhiber l'IN. Le 93del inhibe spécifiquement les activités in vitro de l'IN mais également la réplication virale dans le contexte de cellules humaines infectées. Le mécanisme d'action ex vivo de cet inhibiteur a été étudié. La quantification des différents acides nucléiques viraux montre que le 93del a une action multimodale sur la réplication virale (entrée, transcription inverse, intégration). L'étude de l'entrée du 93del dans les cellules humaines révèle que le virus est capable d'augmenter l'entrée de l'inhibiteur dans différentes lignées de manière indépendante du CD4. Pour étudier spécifiquement le mécanisme d'inhibition du 93del dans le milieu intracellulaire, des expériences de transfections ont été réalisées. Dans ces conditions, le 93del inhibe l'étape d'intégration de manière plus spécifique. D'un autre côté, les petits ligands comme le 93del, peuvent être utilisés pour stabiliser l'IN dans des essais de cristallisation. Plusieurs cristaux d'IN en complexe ou non avec le 93del ont été obtenus. La résolution de la structure de l'IN entière sauvage serait alors une avancée importante permettant l'élaboration de nouveaux inhibiteurs.Human Immunodeficiency Virus type 1 (HIV-1) is a pandemic infectious virus. Incurable disease associate can almost be contained with several treatments. Secondary effects are important and resistant virus appears quickly. We developed in the laboratory combinatorial strategies (SELEX) to isolate ODN with high affinity for RNase H. Keeping in mind that RNAse H and IN core are structurally homologous, ODN were tested in IN inhibition assays. 93 del (dimeric G quadraduplex) inhibit specifically in vitro IN activities and is able to inhibit HIV replication in human infected cells. This ex vivo mechanism of inhibition by 93del was studied. 93del seems to inhibit early steps of replication in a multi-target way (entry, reverse transcription and integration). 93del entry in human cells was then evaluated. HIV-1 viral particles enhance ODN entrance in several cells line in a CD4 independent manner. Transfection of 93del was performed prior to infection. In these conditions, we can observe diminution of viral DNA integrated whereas total DNA keep constant. A new step in this study will be to determinate 93del availability in vivo and in a viral context to see if the molecule in current form could be attractive for therapy. Short ligands like ODN can be used to stabilize IN in crystallization assays. Entire IN without mutation was prepared in S. cerevisiae. Several crystals (enzyme alone or in complex with 93del) were obtained. Resolution of the IN structure would be an important step to design specific inhibitor more easily.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Epidémiologie des accidents de plongée survenus en région marseillaise de 2000 à 2009

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocSudocFranceF

Biochimie

During clinical trials, a number of fully characterized molecules are dropped along the way because they do not provide enough benefit for the patient. Some of them show limited side effects and might be of great use for other applications. AS1411 is a nucleolin-targeting aptamer that underwent phase II clinical trials as anticancer agent. Here, we show that AS1411 exhibits extremely potent antiviral activity and is therefore an attractive new lead as anti-HIV agent

Sci Rep

Mosquito- and tick-borne pathogens including Chikungunya, Dengue, Japanese encephalitis, West Nile, Yellow fever and Zika virus, represent a new economic and public health challenge. In the absence of effective vaccines and specific therapies, only supportive regimens are administrated for most of these infections. Thus, the development of a targeted therapy is mandatory to stop the rapid progression of these pathogens and preoccupant associated burdens such as Guillain-Barre syndrome, microcephaly. For this, it is essential to develop biochemical tools to help study and target key viral enzymes involved in replication such as helicase complexes, methyl-transferases and RNA-dependent RNA polymerases. Here, we show that a highly purified ZIKV polymerase domain is active in vitro. Importantly, we show that this isolated domain is capable of de novo synthesis of the viral genome and efficient elongation without terminal nucleotide transferase activity. Altogether, this isolated polymerase domain will be a precious tool to screen and optimize specific nucleoside and non-nucleoside inhibitors to fight against Zika infections