93 research outputs found
Helicobacter Pylori Infection in Pediatric Patients Living in Europe: Results of the EuroPedHP Registry 2013 to 2016
Objectives: The aim of the study was to assess clinical presentation, endoscopic findings, antibiotic susceptibility and treatment success of Helicobacter pylori (H. pylori) infected pediatric patients.
Methods: Between 2013 and 2016, 23 pediatric hospitals from 17 countries prospectively submitted data on consecutive H. pylori-infected (culture positive) patients to the EuroPedHP-Registry.
Results: Of 1333 patients recruited (55.1% girls, median age 12.6 years), 1168 (87.6%) were therapy naïve (group A) and 165 (12.4%) had failed treatment (group B). Patients resided in North/Western (29.6%), Southern (34.1%) and Eastern Europe (23.0%), or Israel/Turkey (13.4%). Main indications for endoscopy were abdominal pain or dyspepsia (81.2%, 1078/1328). Antral nodularity was reported in 77.8% (1031/1326) of patients, gastric or duodenal ulcers and erosions in 5.1% and 12.8%, respectively. Primary resistance to clarithromycin (CLA) and metronidazole (MET) occurred in 25% and 21%, respectively, and increased after failed therapy. Bacterial strains were fully susceptible in 60.5% of group A, but in only 27.4% of group B. Primary CLA resistance was higher in Southern and Eastern Europe (adjusted odds ratio [ORadj] = 3.44, 95% confidence interval [CI] 2.22-5.32, P < 0.001 and 2.62, 95% CI: 1.63-4.22, P < 0.001, respectively) compared with Northern/Western Europe. Children born outside Europe showed higher primary MET resistance (ORadj = 3.81, 95% CI: 2.25-6.45, P < 0.001). Treatment success in group A reached only 79.8% (568/712) with 7 to 14 days triple therapy tailored to antibiotic susceptibility.
Conclusions: Peptic ulcers are rare in dyspeptic H. pylori-infected children. Primary resistance to CLA and MET is markedly dependent on geographical regions of birth and residence. The ongoing survey will show whether implementation of the updated ESPGHAN/NASPGHAN guidelines will improve the eradication success.info:eu-repo/semantics/publishedVersio
Structure and Functional Analysis of the RNA- and Viral Phosphoprotein-Binding Domain of Respiratory Syncytial Virus M2-1 Protein
Respiratory syncytial virus (RSV) protein M2-1 functions as an essential transcriptional cofactor of the viral RNA-dependent RNA polymerase (RdRp) complex by increasing polymerase processivity. M2-1 is a modular RNA binding protein that also interacts with the viral phosphoprotein P, another component of the RdRp complex. These binding properties are related to the core region of M2-1 encompassing residues S58 to K177. Here we report the NMR structure of the RSV M2-158–177 core domain, which is structurally homologous to the C-terminal domain of Ebola virus VP30, a transcription co-factor sharing functional similarity with M2-1. The partial overlap of RNA and P interaction surfaces on M2-158–177, as determined by NMR, rationalizes the previously observed competitive behavior of RNA versus P. Using site-directed mutagenesis, we identified eight residues located on these surfaces that are critical for an efficient transcription activity of the RdRp complex. Single mutations of these residues disrupted specifically either P or RNA binding to M2-1 in vitro. M2-1 recruitment to cytoplasmic inclusion bodies, which are regarded as sites of viral RNA synthesis, was impaired by mutations affecting only binding to P, but not to RNA, suggesting that M2-1 is associated to the holonucleocapsid by interacting with P. These results reveal that RNA and P binding to M2-1 can be uncoupled and that both are critical for the transcriptional antitermination function of M2-1
Drugs in focus: Botulinum toxin in the therapy of gastrointestinal disorders in children
What is Known
Botulinum toxin (BoNT) causes muscle relaxation by inhibiting acetylcholine release from presynaptic motor neurons at the neuromuscular junction.
What is New
In children with achalasia, BoNT can be considered only in patients in whom rapid weight gain is important to improve surgical outcomes.
BoNT has been suggested for treating cricopharyngeal achalasia and delayed gastric emptying.
Anal achalasia and constipation after Hirschsprung disease corrective surgery are very promising indications for BoNT use.
In selected children with resistant type of functional constipation and chronic anal fissure, BoNT is a viable option for treating
Microtubule Actin Crosslinking Factor 1 Regulates the Balbiani Body and Animal-Vegetal Polarity of the Zebrafish Oocyte
Although of fundamental importance in developmental biology, the genetic basis for the symmetry breaking events that polarize the vertebrate oocyte and egg are largely unknown. In vertebrates, the first morphological asymmetry in the oocyte is the Balbiani body, a highly conserved, transient structure found in vertebrates and invertebrates including Drosophila, Xenopus, human, and mouse. We report the identification of the zebrafish magellan (mgn) mutant, which exhibits a novel enlarged Balbiani body phenotype and a disruption of oocyte polarity. To determine the molecular identity of the mgn gene, we positionally cloned the gene, employing a novel DNA capture method to target region-specific genomic DNA of 600 kb for massively parallel sequencing. Using this technique, we were able to enrich for the genomic region linked to our mutation within one week and then identify the mutation in mgn using massively parallel sequencing. This is one of the first successful uses of genomic DNA enrichment combined with massively parallel sequencing to determine the molecular identity of a gene associated with a mutant phenotype. We anticipate that the combination of these technologies will have wide applicability for the efficient identification of mutant genes in all organisms. We identified the mutation in mgn as a deletion in the coding sequence of the zebrafish microtubule actin crosslinking factor 1 (macf1) gene. macf1 is a member of the highly conserved spectraplakin family of cytoskeletal linker proteins, which play diverse roles in polarized cells such as neurons, muscle cells, and epithelial cells. In mgn mutants, the oocyte nucleus is mislocalized; and the Balbiani body, localized mRNAs, and organelles are absent from the periphery of the oocyte, consistent with a function for macf1 in nuclear anchoring and cortical localization. These data provide the first evidence for a role for spectraplakins in polarization of the vertebrate oocyte and egg
The Phylogenetic Origin of oskar Coincided with the Origin of Maternally Provisioned Germ Plasm and Pole Cells at the Base of the Holometabola
The establishment of the germline is a critical, yet surprisingly evolutionarily
labile, event in the development of sexually reproducing animals. In the fly
Drosophila, germ cells acquire their fate early during
development through the inheritance of the germ plasm, a specialized maternal
cytoplasm localized at the posterior pole of the oocyte. The gene
oskar (osk) is both necessary and
sufficient for assembling this substance. Both maternal germ plasm and
oskar are evolutionary novelties within the insects, as the
germline is specified by zygotic induction in basally branching insects, and
osk has until now only been detected in dipterans. In order
to understand the origin of these evolutionary novelties, we used comparative
genomics, parental RNAi, and gene expression analyses in multiple insect
species. We have found that the origin of osk and its role in
specifying the germline coincided with the innovation of maternal germ plasm and
pole cells at the base of the holometabolous insects and that losses of
osk are correlated with changes in germline determination
strategies within the Holometabola. Our results indicate that the invention of
the novel gene osk was a key innovation that allowed the
transition from the ancestral late zygotic mode of germline induction to a
maternally controlled establishment of the germline found in many holometabolous
insect species. We propose that the ancestral role of osk was
to connect an upstream network ancestrally involved in mRNA localization and
translational control to a downstream regulatory network ancestrally involved in
executing the germ cell program
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
Choix de localisation et signalement de la qualité par les prix
National audienceLes auteurs étudient un modèle de concurrence au sein d'un duopole dans un contexte de différenciation horizontale. Les produits vendus par les firmes peuvent aussi potentiellement différer selon leur qualité. Les firmes choisissent tout d'abord leurs localisations de manière séquentielle puis simultanément leurs prix. A l'étape de localisation, la qualité du suiveur est connaissance commune tandis que la qualité du leader est incertaine mais révélée de manière privée avant l'étape de compétition par les prix. Ils montrent que la perspective de devoir signaler une qualité haute par le prix induit le leader à accroître au maximum la différenciation horizontale du produit. Ce résultat contraste fortement avec l'équilibre en information complète, qui peut impliquer une différenciation minimale ou intermédiaire selon les paramètres du modèle. Ainsi, le principe de différentiation maximale est restauré en présence d'information incomplète
Estimation de la valeur énergétique des aliments pour le porc
National audienceEnergy supply represents the main cost in pig production (>50 %). Therefore, it is quite important to evaluate precisely both the energy requirements of pigs and the energy value of compound feeds or ingredients. This review presents the concepts and the information used for calculating the energy value for pigs of the ingredients (n = 120) listed in the Feeding Tables published by INRA and AFZ in 2002. Simplified methods for estimating the energy value of ingredients whose chemical composition differs from the values given in the Feeding Tables are also proposed. The results are based on a compilation of available literature information and according to the most recent concepts. Six energy values resulting from the combination of three modes of expression (digestible energy, metabolizable energy and net energy) and two stages of pig production (growing pigs and adult sows) have been proposed. The effects of other factors such as technology (pelleting, grinding, …) or feeding level on energy value are also presented. However, the available literature information was insufficient for taking them into account in the estimation of energy value.Cet article présente la démarche adoptée pour le calcul des données de valeur énergétique, pour le porc, des matières premières (n = 120) des Tables publiées par l’INRA et l’AFZ en 2002. Elle propose également des méthodes simplifiées pour le calcul des valeurs énergétiques de produits dont la composition chimique diffère de celle rapportée dans les Tables. Les résultats sont basés sur la compilation des données de la bibliographie et l’utilisation des connaissances les plus récentes en termes de concepts. Six valeurs énergétiques résultant de la combinaison de trois modes d’expression (ED, EM ou EN) et de deux stades physiologiques (porc en croissance et truie adulte) sont proposées. Les effets de facteurs de variation de la valeur énergétique tels que la technologie (granulation, broyage …) ou le niveau d’alimentation sont également abordés, mais les données disponibles dans la bibliographie ne permettaient pas de les prendre en compte, du moins de façon systématique
[Les effets stratégiques des marques de distributeurs]
Série D ; 98-08D ; Diffusion du document : INRA Unité d'Economie et Sociologie rurales CRA Auzeville BP 27 31326 Castanet-Tolosan (FRA) ; Cote de localisation : F4 589 98-08DDans le cadre des relations détaillants-producteurs, les auteurs s'intéressent à la concurrence, au niveau de la distribution, entre un bien sous marque nationale et un autre sous marque de distributeur. C'est une concurrence en prix pour des produits différenciés verticalement : le bien de haute qualité étant le bien de marque nationale et le bien de basse qualité celui de la marque de distributeur. Ils envisagent le cas où les coûts marginaux de production des deux types de biens sont différents, la production d'un bien de haute qualité étant plus coûteuse que celle du bien de basse qualité. Les auteurs étudient les stratégies de prix d'équilibre selon le niveau de qualité du produit sous marque de distributeur et le choix optima de qualité pour la marque de distributeur. L'introduction d'une marque de distributeur réduit le phénomène de double marginalisation. Ils analysent l'effet d'une telle introduction sur les marges et les profits des différents agents
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