Glycosylation of mucins present in gastric juice: the effect of helicobacter pylori eradication treatment

It is suggested that gastric mucins, and in particular some specific glycan structures that can act as carbohydrate receptors, are involved in the interactions with Helicobacter pylori adhesins. The main aim of our study was to evaluate glycosylation pattern of glycoproteins of gastric juice before and at the end of eradication therapy. Gastric juices were taken from 13 clinical patients and subjected to analysis. Pooled fractions of the void volume obtained after gel filtration were subjected to ELISA tests. To assess the relative amounts of carbohydrate structures, lectins and monoclonal antibodies were used. Changes in the level of MUC 1 and MUC 5AC mucins and of carbohydrate structures, which are suggested to be receptors for Helicobacter pylori adhesins, were observed by the end of the eradication treatment. Our results support the idea about the involvement of MUC 5AC and MUC 1 with some specific sugar structures in the mechanism of Helicobacter pylori infection

Replication and active partition of integrative and conjugative elements (ICEs) of the SXT/R391 family : the line between ICEs and conjugative plasmids is getting thinner

Integrative and Conjugative Elements (ICEs) of the SXT/R391 family disseminate multidrug resistance among pathogenic Gammaproteobacteria such as Vibrio cholerae. SXT/R391 ICEs are mobile genetic elements that reside in the chromosome of their host and eventually self-transfer to other bacteria by conjugation. Conjugative transfer of SXT/R391 ICEs involves a transient extrachromosomal circular plasmid-like form that is thought to be the substrate for single-stranded DNA translocation to the recipient cell through the mating pore. This plasmid-like form is thought to be non-replicative and is consequently expected to be highly unstable. We report here that the ICE R391 of Providencia rettgeri is impervious to loss upon cell division. We have investigated the genetic determinants contributing to R391 stability. First, we found that a hipAB-like toxin/antitoxin system improves R391 stability as its deletion resulted in a tenfold increase of R391 loss. Because hipAB is not a conserved feature of SXT/R391 ICEs, we sought for alternative and conserved stabilization mechanisms. We found that conjugation itself does not stabilize R391 as deletion of traG, which abolishes conjugative transfer, did not influence the frequency of loss. However, deletion of either the relaxase-encoding gene traI or the origin of transfer (oriT) led to a dramatic increase of R391 loss correlated with a copy number decrease of its plasmid-like form. This observation suggests that replication initiated at oriT by TraI is essential not only for conjugative transfer but also for stabilization of SXT/R391 ICEs. Finally, we uncovered srpMRC, a conserved locus coding for two proteins distantly related to the type II (actin-type ATPase) parMRC partitioning system of plasmid R1. R391 and plasmid stabilization assays demonstrate that srpMRC is active and contributes to reducing R391 loss. While partitioning systems usually stabilizes low-copy plasmids, srpMRC is the first to be reported that stabilizes a family of ICEs

Towards a deformable multi-surface approach to ligamentous spine models for predictive simulation-based scoliosis surgery planning

Scoliosis correction surgery is typically a highly invasive procedure that involves either an anterior or posterior release, which respectively entail the resection of ligaments and bone facets from the front or back of the spine, in order to make it sufficiently compliant to enable the correction of the deformity. In light of progress in other areas of surgery in minimally invasive therapies, orthopedic surgeons have begun envisioning computer simulation-assisted planning that could answer unprecedented what-if questions. This paper presents preliminary steps taken towards simulation-based surgery planning that will provide answers as to how much anterior or posterior release is truly necessary, provided we also establish the amplitude of surgical forces involved in corrective surgery. This question motivates us to pursue a medical image-based anatomical modeling pipeline that can support personalized finite elements simulation, based on models of the spine that not only feature vertebrae and inter-vertebral discs (IVDs), but also descriptive ligament models. This paper suggests a way of proceeding, based on the application of deformable multi-surface Simplex model applied to a CAD-based representation of the spine that makes explicit all spinal ligaments, along with vertebrae and IVDs. It presents a preliminary model-based segmentation study whereby Simplex meshes of CAD vertebrae are registered to the subject’s corresponding vertebrae in CT data, which then drives ligament and IVD model registration by aggregation of neighboring vertebral transformations. This framework also anticipates foreseen improvements in MR imaging that could achieve better contrasts in ligamentous tissues in the future

Inflammation affects the viability and plasticity of equine mesenchymal stem cells: possible implications in intra-articular treatments

Mesenchymal stem cells (MSCs) are gaining relevance for treating equine joint injuries because of their ability to limit inflammation and stimulate regeneration. Because inflammation activates MSC immunoregulatory function, proinflammatory priming could improve MSC efficacy. However, inflammatory molecules present in synovial fluid or added to the culture medium might have deleterious effects on MSCs. Therefore, this study was conducted to investigate the effects of inflammatory synovial fluid and proinflammatory cytokines priming on viability and plasticity of equine MSCs. Equine bone marrow derived MSCs (eBM-MSCs) from three animals were cultured for 72 h in media supplemented with: 20% inflammatory synovial fluid (SF); 50 ng/mL IFN-γ and TNF-α (CK50); and 20 ng/mL IFN-γ and TNF-α (CK20). Proliferation assay and expression of proliferation and apoptosis-related genes showed that SF exposed-eBM-MSCs maintained their viability, whereas the viability of CK primed-eBM-MSCs was significantly impaired. Tri-lineage differentiation assay revealed that exposure to inflammatory synovial fluid did not alter eBM-MSCs differentiation potential; however, eBM-MSCs primed with cytokines did not display osteogenic, adipogenic or chondrogenic phenotype. The inflammatory synovial environment is well tolerated by eBM-MSCs, whereas cytokine priming negatively affects the viability and differentiation abilities of eBM-MSCs, which might limit their in vivo efficacy