Prevalence of Vitamin A Deficiency in Pregnant and Lactating Women in the Republic of Congo

Vitamin A status in a sample of pregnant and lactating women living in several representative regions of Congo was assessed and compared between August and September 2004. This survey was conducted using a randomized two-stage cluster-sampling method with stratification on 90 clusters, each consisting of at least 15 women. Vitamin A status was determined in a total of 1,054 individuals, using the impression cytology with transfer (ICT) test, the modified relative dose response test (MRDR test) on dried blood spots (DBS), and clinical examination to detect signs of xerophthalmia. The clinical criterion defining vitamin A deficiency was the presence of active xerophthalmia (Bitot's spots [X1B]), active corneal disease), and/ or night blindness (XN stage). The prevalence of clinical signs of stage XN and X1B xerophthalmia in the Republic of Congo was found to be 16% and 19% respectively. The prevalence of clinical signs (X1B) was greater in the rural north than in urban areas, with a gradient running from urban (5%) to rural area (33%); 27% of all the ICT tests showed that the subjects were suffering from vitamin A deficiency. The deficiency rates were significantly higher (p<0.001) in urban surroundings (Brazzaville) than in the rural northern regions. The biochemical MRDR test showed the presence of vitamin A deficiency ( 650.06) in 26% of the mothers in Brazzaville compared to 6% in the town of Kouilou; 44% of the women had retinol levels of <10 \ub5g/dL in the rural north whereas these percentages were significantly lower in the urban areas surveyed (chi-square=62.30, p<0.001). A significant correlation was found to exist (p<0.001) between the ICT test and the MRDR test on DBS. In the population as a whole, 30% of the mothers suffering from malarial attack had abnormally low MRDR levels ( 650.06) compared to no malaria. The results of the present study confirm that vitamin A deficiency is a serious public-health issue in pregnant and lactating mothers in the Republic of Congo

Pathogenic Bacteria Target NEDD8-Conjugated Cullins to Hijack Host-Cell Signaling Pathways

The cycle inhibiting factors (Cif), produced by pathogenic bacteria isolated from vertebrates and invertebrates, belong to a family of molecules called cyclomodulins that interfere with the eukaryotic cell cycle. Cif blocks the cell cycle at both the G1/S and G2/M transitions by inducing the stabilization of cyclin-dependent kinase inhibitors p21waf1 and p27kip1. Using yeast two-hybrid screens, we identified the ubiquitin-like protein NEDD8 as a target of Cif. Cif co-compartmentalized with NEDD8 in the host cell nucleus and induced accumulation of NEDD8-conjugated cullins. This accumulation occurred early after cell infection and correlated with that of p21 and p27. Co-immunoprecipitation revealed that Cif interacted with cullin-RING ubiquitin ligase complexes (CRLs) through binding with the neddylated forms of cullins 1, 2, 3, 4A and 4B subunits of CRL. Using an in vitro ubiquitylation assay, we demonstrate that Cif directly inhibits the neddylated CUL1-associated ubiquitin ligase activity. Consistent with this inhibition and the interaction of Cif with several neddylated cullins, we further observed that Cif modulates the cellular half-lives of various CRL targets, which might contribute to the pathogenic potential of diverse bacteria

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

Méthodes d'évaluation du statut en vitamine A chez les enfants d'âge préscolaire et chez les femmes enceintes ou allaitantes dans le contexte du Congo Brazzaville

Le déficit en vitamine A est un grave problème de santé publique chez les femmes enceintes ou allaitantes et chez les jeunes enfants en République du Congo. Les travaux originaux et les résultats présentés dans notre travail de thèse contribuent significativement à la progression de la lutte contre la malnutrition et la carence en vitamine A sur le continent Africain en apportant les informations épidémiologiques et les données biologiques nécessaires à une cartographie de la xérophtalmie au Congo Brazzaville ainsi que des propositions d interventions nutritionnelles et de mesures d urgence palliatives sur le terrain. Les travaux présentés dans le manuscrit ont permis ont permis de valider une méthode innovante d évaluation du statut en vitamine A. La technique simple est applicable à grande échelle dans des conditions tropicales difficiles. Il s agit de la technique dite de dose-réponse relative modifiée (modified relative dose response) (MRDR) sur taches de sang séché (TSS) qui permet de préciser le niveau de déficit en vitamine A. Le test d impression oculaire (IOT), utilisé en complément de l outil analytique a permis d élargir le programme de dépistage et d évaluation. Les résultats du test MRDR sur TSS sont en faveur d une diminution des réserves hépatiques en vitamine A dans cette population à risquePARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Prevalence of Vitamin A Deficiency in Pregnant and Lactating Women in the Republic of Congo

Vitamin A status in a sample of pregnant and lactating women living in several representative regions of Congo was assessed and compared between August and September 2004. This survey was conducted using a randomized two-stage cluster-sampling method with stratification on 90 clusters, each consisting of at least 15 women. Vitamin A status was determined in a total of 1,054 individuals, using the impression cytology with transfer (ICT) test, the modified relative dose response test (MRDR test) on dried blood spots (DBS), and clinical examination to detect signs of xerophthalmia. The clinical criterion defining vitamin A deficiency was the presence of active xerophthalmia (Bitot's spots [X1B]), active corneal disease), and/ or night blindness (XN stage). The prevalence of clinical signs of stage XN and X1B xerophthalmia in the Republic of Congo was found to be 16% and 19% respectively. The prevalence of clinical signs (X1B) was greater in the rural north than in urban areas, with a gradient running from urban (5%) to rural area (33%); 27% of all the ICT tests showed that the subjects were suffering from vitamin A deficiency. The deficiency rates were significantly higher (p<0.001) in urban surroundings (Brazzaville) than in the rural northern regions. The biochemical MRDR test showed the presence of vitamin A deficiency (≥0.06) in 26% of the mothers in Brazzaville compared to 6% in the town of Kouilou; 44% of the women had retinol levels of <10 µg/dL in the rural north whereas these percentages were significantly lower in the urban areas surveyed (chi-square=62.30, p<0.001). A significant correlation was found to exist (p<0.001) between the ICT test and the MRDR test on DBS. In the population as a whole, 30% of the mothers suffering from malarial attack had abnormally low MRDR levels (≥0.06) compared to no malaria. The results of the present study confirm that vitamin A deficiency is a serious public-health issue in pregnant and lactating mothers in the Republic of Congo

Le vécu délirant à travers le Rorschach (phénomènes structuraux et contexte culturel)

Vécu délirant, contexte culturel. Etude phénoméno-structurale à partie des images produites au Rorschach : outil privilégié et apte à mieux les produire et les analyser. Le Rorschach met en valeur vision en images, vécu du sujet, structure mentale individuelle, délire et culture. En saisissant le dynamisme de la structure mentale, il permet d'articuler les traits pathologiques et culturels. En référence à la typologie et aux mécanismes essentiels (Lien-Coupure) de F. Minkowska, l'image est connection avec la réalité, lien (cf G. Bachelard, F. Minkowska, Z. Helman) ; de même la culture, cette structure commune porteuse, espace de lien et de partage, qui fait image nous fait tenir ensemble et tenir les mythes. Or le délire est davantage coupure. Comment se fait-il que le délirant voit en image ? L'image délirante ne tient pas, se tranforme par manque d'ancrage, d'enracinement devant la durée. Dans les bouffées délirantes (cf 1ère thèse : 1981), la coupure ne va pas jusqu'au bout, car "Coupure uniquement dans la durée et Appel à l'image". Avec 2ème thèse des délirants chroniques congolais (kongo-lari) in situ, la coupure totale, est dans l'image même. Il y a dissociation, transformation et magie. Sous traitement : -Transformation masquée liée à la poussée sensori-motrice, -Enrichissement de la qualité expressive : rôle de l'émotion et de la magie (FClob) lié à la tradition culturelle. Grâce à l'image + durée (cf 1er gr.) : enrichissement (ou gain sensoriel) de l'image mais sur fond de coupure. En réalité, c'est discordant mais contact un peu meilleur. En revanche (cf 2ème gr.) pas d'image, pas de poussée sensori-motrice -spatialisation, immobilisme, géométrisme voire topologisation de la vision - Pauvreté expressive - La coupure s'aggrave, en dépit parfois de l'émotion, sans image, qui, à elle seule, ne suffit pasLILLE3-BU (590092101) / SudocSudocFranceF

The Enteropathogenic Escherichia coli Effector Cif Induces Delayed Apoptosis in Epithelial Cells▿

The cycle inhibiting factor (Cif) belongs to a family of bacterial toxins, the cyclomodulins, which modulate the host cell cycle. Upon injection into the host cell by the type III secretion system of enteropathogenic Escherichia coli (EPEC), Cif induces both G2 and G1 cell cycle arrests. The cell cycle arrests correlate with the accumulation of p21waf1 and p27kip1 proteins that inhibit CDK-cyclin complexes, whose activation is required for G1/S and G2/M transitions. Increases of p21 and p27 levels are independent of p53 transcriptional induction and result from protein stabilization through inhibition of the ubiquitin/proteasome degradation pathway. In this study, we show that Cif not only induces cell cycle arrest but also eventually provokes a delayed cell death. Indeed, 48 h after infection with EPEC expressing Cif, cultured IEC-6 intestinal cells were positive for extracellular binding of annexin V and exhibited high levels of cleaved caspase-3 and lactate dehydrogenase release, indicating evidence of apoptosis. Cif was necessary and sufficient for inducing this late apoptosis, and the cysteine residue of the catalytic site was required for Cif activity. These results highlight a more complex role of Cif than previously thought, as a cyclomodulin but also as an apoptosis inducer

Bacterial cyclomodulin Cif blocks the host cell cycle by stabilizing the cyclin-dependent kinase inhibitors p21 waf1 and p27 kip1

The cycle inhibiting factor (Cif) is a cyclomodulin produced by enteropathogenic and enterohemorrhagic Escherichia coli. Upon injection into the host cell by the bacterial type III secretion system, Cif inhibits the G2/M transition via sustained inhibition of the mitosis inducer CDK1 independently of the DNA damage response. In this study, we show that Cif induces not only G2, but also G1 cell cycle arrest depending on the stage of cells in the cell cycle during the infection. In various cell lines including differentiated and untransformed enterocytes, the cell cycle arrests are correlated with the accumulation of the cyclin‐dependent kinase inhibitors p21waf1/cip1 and p27kip1. Cif‐induced cyclin‐dependent kinase inhibitor accumulation is independent of the p53 pathway but occurs through inhibition of their proteasome‐mediated degradation. Our results provide a direct link between the mode of action of Cif and the host cell cycle control

Evaluation of remotely sensed rainfall products over Central Africa.

24 pagesInternational audienceAn intercomparison of seven gridded rainfall products incorporating satellite data (ARC, CHIRPS, CMORPH, PERSIANN, TAPEER, TARCAT, TMPA) is carried out over Central Africa, by evaluating them against three observed datasets: (a) the WaTFor database, consisting of 293 (monthly records) and 154 (daily records) rain‐gauge stations collected from global datasets, national meteorological services and monitoring projects, (b) the WorldClim v2 gridded database, and (c) a set of stations expanded from the FAOCLIM network, these two latter sets describing climate normals. All products fairly well reproduce the mean rainfall regimes and the spatial patterns of mean annual rainfall, although with some discrepancies in the east–west gradient. A systematic positive bias is found in the CMORPH product. Despite its lower spatial resolution, TAPEER shows reasonable skills. When considering daily rainfall amounts, TMPA shows best skills, followed by CMORPH, but over the central part of the Democratic Republic of the Congo, TARCAT is amongst the best products. Skills ranking is however different at the interannual time‐scale, with CHIRPS and TMPA performing best, though PERSIANN has comparable skills when only fully independent stations are used as reference. A preliminary study of Southern Hemisphere dry season variability, from the example of Kinshasa, shows that it is a difficult variable to capture with satellite‐based rainfall products. Users should still be careful when using any product in the most data‐sparse regions, especially for trend assessment