43,863 research outputs found

    How best to manage the patient in term labor whose group B strep status is unknown?

    Get PDF
    Monitor the patient and treat her with intrapartum chemoprophylaxis based on identified risk factors, unless a rapid, highly sensitive (greater than or equal to 85%) polymerase chain reaction (PCR) test is immediately available to evaluate for group B Streptococcus (GBS) (strength of recommendation: B, inconsistent or limited quality evidence)

    \u3cem\u3eIn vitro\u3c/em\u3e Effect of Graphene Structures as an Osteoinductive Factor in Bone Tissue Engineering: A Systematic Review

    Get PDF
    Graphene and its derivatives have been well‐known as influential factors in differentiating stem/progenitor cells toward the osteoblastic lineage. However, there have been many controversies in the literature regarding the parameters effect on bone regeneration, including graphene concentration, size, type, dimension, hydrophilicity, functionalization, and composition. This study attempts to produce a comprehensive review regarding the given parameters and their effects on stimulating cell behaviors such as proliferation, viability, attachment and osteogenic differentiation. In this study, a systematic search of MEDLINE database was conducted for in vitro studies on the use of graphene and its derivatives for bone tissue engineering from January 2000 to February 2018, organized according to the PRISMA statement. According to reviewed articles, different graphene derivative, including graphene, graphene oxide (GO) and reduced graphene oxide (RGO) with mass ratio ≤1.5 wt % for all and concentration up to 50 μg/mL for graphene and GO, and 60 μg/mL for RGO, are considered to be safe for most cell types. However, these concentrations highly depend on the types of cells. It was discovered that graphene with lateral size less than 5 µm, along with GO and RGO with lateral dimension less than 1 µm decrease cell viability. In addition, the three‐dimensional structure of graphene can promote cell‐cell interaction, migration and proliferation. When graphene and its derivatives are incorporated with metals, polymers, and minerals, they frequently show promoted mechanical properties and bioactivity. Last, graphene and its derivatives have been found to increase the surface roughness and porosity, which can highly enhance cell adhesion and differentiation

    Utilizing osteocyte derived factors to enhance cell viability and osteogenic matrix deposition within IPN hydrogels

    Get PDF
    Many bone defects arising due to traumatic injury, disease, or surgery are unable to regenerate, requiring intervention. More than four million graft procedures are performed each year to treat these defects making bone the second most commonly transplanted tissue worldwide. However, these types of graft suffer from a limited supply, a second surgical site, donor site morbidity, and pain. Due to the unmet clinical need for new materials to promote skeletal repair, this study aimed to produce novel biomimetic materials to enhance stem/stromal cell osteogenesis and bone repair by recapitulating aspects of the biophysical and biochemical cues found within the bone microenvironment. Utilizing a collagen type I-alginate interpenetrating polymer network we fabricated a material which mirrors the mechanical and structural properties of unmineralized bone, consisting of a porous fibrous matrix with a young's modulus of 64 kPa, both of which have been shown to enhance mesenchymal stromal/stem cell (MSC) osteogenesis. Moreover, by combining this material with biochemical paracrine factors released by statically cultured and mechanically stimulated osteocytes, we further mirrored the biochemical environment of the bone niche, enhancing stromal/stem cell viability, differentiation, and matrix deposition. Therefore, this biomimetic material represents a novel approach to promote skeletal repair

    Structural and functional characterization of Pseudomonas aeruginosa CupB chaperones

    Get PDF
    Pseudomonas aeruginosa, an important human pathogen, is estimated to be responsible for,10% of nosocomial infections worldwide. The pathogenesis of P. aeruginosa starts from its colonization in the damaged tissue or medical devices (e. g. catheters, prothesis and implanted heart valve etc.) facilitated by several extracellular adhesive factors including fimbrial pili. Several clusters containing fimbrial genes have been previously identified on the P. aeruginosa chromosome and named cup [1]. The assembly of the CupB pili is thought to be coordinated by two chaperones, CupB2 and CupB4. However, due to the lack of structural and biochemical data, their chaperone activities remain speculative. In this study, we report the 2.5 A crystal structure of P. aeruginosa CupB2. Based on the structure, we further tested the binding specificity of CupB2 and CupB4 towards CupB1 (the presumed major pilus subunit) and CupB6 (the putative adhesin) using limited trypsin digestion and strep-tactin pull-down assay. The structural and biochemical data suggest that CupB2 and CupB4 might play different, but not redundant, roles in CupB secretion. CupB2 is likely to be the chaperone of CupB1, and CupB4 could be the chaperone of CupB4:CupB5:CupB6, in which the interaction of CupB4 and CupB6 might be mediated via CupB5

    Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue

    Get PDF
    The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+) T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+) T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi) T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+) T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines

    Antibiotic prescribing by general dental practitioners in the Greater Glasgow Health Board, Scotland

    Get PDF
    OBJECTIVE: To investigate antibiotic prescribing patterns by general dental practitioners (GDPs) in the Greater Glasgow Health Board Area, Scotland. STUDY DESIGN: A 10% sample of prescriptions were selected at random from 35,545 prescriptions written by GDPs over a 6-month period. MAIN OUTCOME MEASURES: Absolute and relative frequencies were used to describe the different classes of antibiotics used and the variations in prescribing practice. RESULTS: GDPs prescribed a wide range of antibiotics. Seventeen different antibiotics were prescribed with amoxycillin, metronidazole and penicillin V accounting for almost 90% of the prescriptions. In general the antibiotics were prescribed at the British National Formulary (BNF) recommended doses. There were, however, wide variations in the frequencies and durations of the prescriptions for all antibiotics. CONCLUSIONS: The present study provides evidence of sub-optimal prescribing of antibiotics by dentists in Scotland, with considerable variation from the recommended frequencies and doses

    The role of agriculture for overcoming rural poverty in Romania

    Get PDF
    Topical literature sees agriculture's ability to provide food and cash income as a major role in poverty reduction. However, it can only be a driving force for economic development for very poor countries. Economic indicators confirm that Romania is not a very poor country, although poverty has been an issue. During recent years, Romania has progressed successfully in reducing poverty. On the one hand, this can be attributed to its positive overall economic development. On the other hand, agriculture has served as a social safety net for many millions of people. Now the agricultural sector is dominated by subsistent and semi-subsistent farm households headed by persons of retirement age without formal agricultural training. Only 40% of the utilised agricultural area (UAA) is operated from commercial private and corporate farms. Thus, their creating incentives for economic growth are unlikely. While large-scale corporate farms are already integrated in agri-food chains, the upcoming group of commercial private farmers will have to show that it can compete on the agri-food market. Although agriculture has been contributing to poverty reduction, there are good reasons to believe that future economic development will rather come from outside the agricultural sector and agriculture will continue to play the role of a social safety net. Strengthening the Romanian agricultural sector calls for concerted policy actions that are targeted to different groups. Fostering land restitution to former owner families, developing a functioning land sales and rental market, and providing access to agricultural product markets could promote the resurgence of a highly productive group of commercial private farmers. Non-farm job creation in rural areas could provide income opportunities for an abundant agricultural labour force. Both new farmers and potential non-farm employees seem to require profession-specific advice and training to become competitive in their transition environment. The large group of pensioners could be convinced to exit the agricultural sector if they could rely on an income from social provisions that covers their daily needs. --

    Conjugative transfer frequencies of mef(A)-containing Tn1207.3 to macrolide-susceptible Streptococcus pyogenes belonging to different emm types

    Get PDF
    The aim of this study was to examine the gene transfer potential of mef(A)-containing Tn120.3 to macrolide-susceptible Streptococcus pyogenes belonging to different emm types. Using the filter mating technique, Tn1207.3 was transferred by conjugation to 23 macrolide-susceptible recipients representing 11 emm types. PCR analysis confirmed the presence of the mef(A) gene and the comEC junction regions of the Tn1207.3 insertion in resultant transconjugants. Significant variation was found in the transfer frequency of Tn1207.3 to different Strep. pyogenes strains, and this phenomenon may contribute to the differences in mef(A) frequency observed among clinical isolates. Significance and Impact of the Study: The spread of antimicrobial resistance among pathogenic bacteria is an important problem, but the mechanisms of horizontal transfer between strains and species are often poorly understood. For instance, little is known on how macrolide resistance spreads between strains of the human pathogen Strep. pyogenes and why certain strains more commonly display resistance than others. Here, we show that Strep. pyogenes strains vary greatly in their ability to acquire a transposon encoding macrolide resistance by horizontal gene transfer in vitro. These data provide a novel insight into the transfer of antibiotic resistance between bacterial strains and offer an explanation for the differences in the frequency of resistance determinates and resistance seen among clinical isolates. © 2014 The Authors Letters in Applied Microbiology
    corecore