32 research outputs found
L’atteinte nerveuse au cours du syndrome de gougerot - sjögren, a propos d’un cas
Description Les complications neurologiques au cours du syndrome de Gougerot-Sjögren se voient dans 8,5 à 70 % des cas. Les données de la littérature concernant le système nerveux périphérique sont nombreuses et assez concordantes. En revanche les données concernant les manifestations centrales sont beaucoup plus rares et discordantes. Objectifs Décrire les différentes atteintes neurologiques qui peuvent se voir au cours du syndrome de Gougerot- Sjögren. Résultats Les auteurs rapportent l’observation d’une femme de 67 ans qui présentait une hypertrophie de toutes les glandes salivaires associée à une paralysie du facial droit et une hypoesthésie du territoire du trijumeau homolatéral. Les explorations paracliniques comprenant une biopsie labiale et une IRM cérébrale ont permis de conclure en faveur d’un syndrome de Gougerot-Sjögren. La patiente a bénéficié d’un traitement corticoïde par voie générale avec régression totale des atteintes salivaire et nerveuse au bout de 2 mois Conclusion Le syndrome de Gougerot-Sjögren est une pathologie chronique auto-immune qui touche essentiellement les glandes exocrines. Il peut associer aussi une atteinte extra-glandulaire. L’atteinte nerveuse est possible mais rarement vue dans le cadre de ce syndrome (20%). L’atteinte des paires crâniennes est encore plusrare et prédomine surtout sur le trijumeau
An adenovirus-based vaccine manufacturing technology platform for mucosal or parenteral immunization against poultry diseases in sub-Saharan Africa
Developing novel vaccine technology platforms to respond to emergency situations such as pandemic threats or zoonotic diseases is a worldwide high priority. Public health at a global scale is frequently influenced by the risk of transmission of infectious diseases from wildlife and domestic animals. Thus, veterinary vaccination and animal health monitoring are highly relevant for the deployment of a preventative global policy in the context of “one world, one health”.
In regions such as Sub-Saharan Africa, farmers’ activities are frequently affected by the impact of diseases in poultry such as avian influenza and Newcastle disease (ND). ND is one of the most critical, with several outbreaks per year. Currently, protection is provided by vaccination with live vaccines produced only in embryonated eggs, with limitations related to egg supply and the possibility of virus shedding by vaccinated poultry, leading to disease in non-vaccinated birds.
The purpose of this work was to develop an adenovirus (Ad) vectored vaccine platform technology suitable for the rapid adaptation to ND or other avian viral threats. The project involved the phylogenetic analysis of local isolates of Newcastle disease virus (NDV) and the construction of adenoviral vectors expressing the F and HN antigens from NDV genotype VI, either as individual antigens or in bicistronic vectors. Remarkably, adenoviral rescue and generation of primary stocks was streamlined by developing a novel procedure for single step amplification in suspension cultures.
Please click Download on the upper right corner to see the full abstract
Optimization of rAd5 vectored Newcastle vaccine production in HEK293 at high cell densities
Newcastle disease (ND) is a highly contagious and often severe global spread syndrome that affects birds including domestic poultry. It is caused by a virus belonging to the paramyxoviridae family.
Indeed, an outbreak of ND can be quite severe, and is considered as a constant threat to the industry and food security worldwide. The disease can be controlled through the administration of effective vaccines.
Immunizations with inactivated or live vaccines, although protective, have some eminent disadvantages.
The aims of this work is the development of a vectored vaccine using a non-replicative human adenovirus vector, expressing the F antigen from Newcastle Disease Virus (rAd-F-ND) in bioreactor. The recombinant vaccine is produced using the HEK293 cell line.
HEK293 cultures were carried out in suspension, first in shake flasks and then in stirred bioreactor at 37°C, 5% CO2 and 150 rpm in chemically defined media. The virus titers were determined by qPCR.
To improve rAd-F-ND virus productions in HEK-293 cells, we studied the effects of the following parameters in shake flask cultures: culture media (Hycell Trans FX-H and Xell-GM), cell density, multiplicity of infection (MOI) and feed (Xell-FS , Xell-GM and cell Boost 5).
Please click Download on the upper right corner to see the full abstract
Loss of genetic diversity as a signature of apricot domestication and diffusion into the Mediterranean Basin
Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699In order to reduce energy waste for artificial lights and subsequent air conditioning in plant growth chambers, the aim of this preliminary study was to evaluate the feasibility of growing the microvine under 100% of LED illumination. Plant growth under two different LED lights was compared amongst each other and with plants maintained in greenhouse conditions. Regarding the impact on the reproductive and vegetative systems, the study showed that LED light is suitable to grow microvines in confined environments. Plants exposed to LED light exhibited similar leaf emergence rate but reduced vegetative and reproductive organ size compared to plants grown in the greenhouse. Photosynthesis for plants exposed to LED light was higher than what is usually observed on grapevine under natural conditions
Long-term outcome of Tunisian children with primary ciliary dyskinesia confirmed by transmission electron microscopy.
Background: Primary ciliary dyskinesia (PCD) is rare. Its diagnosis
requires experienced specialists and expensive infrastructure. Its
prognosis is variable. Objective: To study the long-term outcome of PCD
in Tunisian children with ciliary ultra-structure defects detected by
electron microscope. Methods: Covering a period of 20 years
(1996-2015), this retrospective study included all patients with
definite PCD (outer dynein arms (DA) defects and/or situs inversus) and
presumed PCD (other ciliary ultra-structure defects). The clinical data
and the investigations made were registered at diagnosis and during the
follow-up. Results: Patients with a definite PCD (G1, n=7) were
diagnosed earlier compared to those with a presumed PCD (G2, n=13) (2.5
vs. 9.3 years on average). At diagnosis, bronchiectasis was more
frequent in G1 (3/7 vs. 4/13). The inner DA loss was constant in G1 and
predominant in G2. The treatment adhesion was more often irregular in
G2 (2/7 vs. 8/13). During a mean follow-up of 11 years, G1 showed less
severe outcome (clubbing (0 vs. 3), bronchiectasis (3 vs. 11; more
expanded in G2), proximal and distal airway obstruction (0/3 vs. 5/7),
lobectomy (0 vs. 2), and death (0 vs. 2)). Conclusion: Precocious
diagnosis and regular treatment may enhance the PCD prognosis
Recommended from our members
Pacifica: Poetry International: Revolutions in Tunisian Poetry
A collection of contemporary poetry from Tunisia, including poems in translation with their French and Arabic original texts
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Process intensification for an enhanced replication of a newly adapted RM-65 sheep pox virus strain in Vero cells grown in stirred bioreactor
International audienceSheep pox virus initially adapted to replicate in primary lamb kidney cells was adapted to Vero cells by serial passages in monolayer cultures. After nine passages the virus was able to correctly replicate in Vero cells, virus titer achieved was 10(5.875) TCID50 (median tissue culture infective dose) ml(-1). To optimize the production process, the effects of MO! (multiplicity of infection), TOI (time of infection) and the culture medium were investigated. Cell infection at a MO! of 0.005 concurrently with cell seeding showed the best results in terms of specific virus productivity. The effect of MEM enrichment with several components was investigated using the experimental design approach. 67 experiments were performed in 6-well plates to select the best combination. The highest titer was achieved when MEM was supplemented with 5 mM glucose, 5 mM fructose and 25 mM sucrose. Spinner culture confirms these data; virus titer was 10(7.375) TCID50 ml(-1). In addition Vero cells were cultivated in a 7-1 bioreactor in batch mode on 3 gl(-1) Cytodex1, and infected at cell seeding at a MO! of 0.005. Maximal virus titer was 10(7.275) TCID50 ml(-1). This corresponds to 44-fold factor enhancement compared to spinner cultures conducted in MEM + 2% FCS. (C) 2014 Elsevier B.V. All rights reserved
Optimization of virus yield as a strategy to improve rabies vaccine production by Vero cells in a bioreactor
International audienceTo improve rabies vaccine production by Vero cells, we have developed a strategy based on high cell density culture and optimization of virus yield. We have first optimized cell growth in spinner flask using a Taguchi's L8 experimental design. We analyzed the effects of the following factors: initial glucose and glutamine concentrations, Cytodex 1 concentration and the regulation of glucose level at 1 g l(-1). We have also investigated the effect of the following factor interactions: Cytodex 1 concentration/glutamine concentration, Cytodex 1 concentration/glucose concentration and glucose concentration/glutamine concentration. Statistical analysis of the collected data pointed to the initial glucose concentration, the regulation of glucose level at 1 g l(-1) and the interactions between Cytodex 1 concentration/initial glucose concentration and Cytodex 1 concentration/initial glutamine concentration as the parameters that affected cell growth. Using the optimal conditions determined earlier, we have studied Vero cell growth in a 7-l bioreactor and in batch culture, and obtained a cell density level equal to 3.6 +/- 0.2 x 10(6) cells ml-1. Cell infection with rabies virus (LP 2061/Vero strain) at a multiplicity of infection (MOI) of 0.3 using M199 medium supplemented with 0.2% bovine serum albumin (BSA), yielded a maximal virus titer equal to 8 +/- 1.6 x 10(7) Fluorescent Focus Units (FFU) ml-1. We have also studied Vero cell growth in a 7-l bioreactor using recirculation as a perfusion culture mode during cell proliferation step and perfusion for virus multiplication phase. In comparison to batch culture, we reached a higher cell density level that was equal to 10.1 +/- 0.5 x 10(6) cells ml-1. Cell infection under the conditions previously indicated, yielded 14l of virus harvest that had a virus titer equal to 2.6 +/- 0.5 x 10(7) FFU ml-1. The activity of the inactivated virus harvest showed a protective activity that meets WHO requirements
Comparison of various culture modes for the production of rabies virus by Vero cells grown on microcarriers in a 2-l bioreactor
International audienceWe studied Vero cell growth on Cytodex 1 (3 g/l) and MEM supplemented with foetal calf serum (FCS) in a 2-l bioreactor using continuous (recirculation and perfusion) and batch culture modes. We achieved a cell density level equal to 4.35 × 106 cells/ml using the recirculation culture mode while perfused cultures yielded a higher cell density level equal to 4.73 × 106 cells/ml. However, as compared to the recirculation culture mode, the specific medium consumption rate was two-fold higher. Batch culture of Vero cells resulted in 2.2 × 106 cells/ml with a specific medium consumption rate similar to recirculation culture.Rabies virus production (LP 2061/Vero strain) by Vero cells was also investigated. We analysed in spinner flasks, the effects on virus multiplication of multiplicity of infection (MOI), regulation of glucose level to 1 g/l and type of medium. The highest virus titer was reached when cells were infected at an MOI of 0.3 in M199 medium supplemented with 0.2% of bovine serum albumin (BSA) and without regulating glucose level. In these conditions, virus titer was equal to 1.5 × 106 fluorescent focus units (FFU)/ml.We then evaluated rabies virus production by Vero cells grown on 3 g/l of Cytodex 1 using recirculation culture mode during the growth phase. Cells were infected at the optimal conditions previously determined. The maximal virus titer was equal to 2 × 107 FFU/ml. The activity of the experimental vaccine prepared showed a protective activity that meets WHO requirements