202 research outputs found
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Investigating the cultural and contextual determinants of antimicrobial stewardship programmes across low-, middle- and high-income countries—A qualitative study
Background
Most of the evidence on antimicrobial stewardship programmes (ASP) to help sustain the effectiveness of antimicrobials is generated in high income countries. We report a study investigating implementation of ASP in secondary care across low-, middle- and high-income countries. The objective of this study was to map the key contextual, including cultural, drivers of the development and implementation of ASP across different resource settings.
Materials and methods
Healthcare professionals responsible for implementing ASP in hospitals in England, France, Norway, India, and Burkina Faso were invited to participate in face-to face interviews. Field notes from observations, documentary evidence, and interview transcripts were analysed using grounded theory approach. The key emerging categories were analysed iteratively using constant comparison, initial coding, going back the field for further data collection, and focused coding. Theoretical sampling was applied until the categories were saturated. Cross-validation and triangulation of the findings were achieved through the multiple data sources.
Results
54 participants from 24 hospitals (England 9 participants/4 hospitals; Norway 13 participants/4 hospitals; France 9 participants/7 hospitals; India 13 participants/ 7 hospitals; Burkina Faso 8 participants/2 hospitals) were interviewed. Across Norway, France and England there was consistency in ASP structures. In India and Burkina Faso there were country level heterogeneity in ASP. State support for ASP was perceived as essential in countries where it is lacking (India, Burkina Faso), and where it was present, it was perceived as a barrier (England, France). Professional boundaries are one of the key cultural determinants dictating involvement in initiatives with doctors recognised as leaders in ASP. Nurse and pharmacist involvement was limited to England. The surgical specialty was identified as most difficult to engage with in each country. Despite challenges, one hospital in India provided the best example of interdisciplinary ASP, championed through organisational leadership.
Conclusions
ASP initiatives in this study were restricted by professional boundaries and hierarchies, with lack of engagement with the wider healthcare workforce. There needs to be promotion of interdisciplinary team work including pharmacists and nurses, depending on the available healthcare workforce in different countries, in ASP. The surgical pathway remains a hard to reach, but critical target for ASP globally. There is a need to develop contextually driven ASP targeting the surgical pathway in different resource settings
Introduction of highly resistant bacteria into a hospital via patients repatriated or recently hospitalized in a foreign country
AbstractWe describe the prevalence of carriage and variables associated with introduction of highly drug-resistant microorganisms (HDRMO) into a French hospital via patients repatriated or recently hospitalized in a foreign country. The prevalence of HDRMO was 11% (15/132), with nine carbapenamase-producing Enterobacteriaceae, nine carbapenem-resistant Acinetobacter baumannii and six glycopeptide-resistant enterococci. Half of the admitted patients (63/132, 48%) were colonized with extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBLPE). Among the four episodes with secondary cases, three involved A. baumannii
A regulatory region on RIPK2 is required for XIAP binding and NOD signaling activity.
Signaling via the intracellular pathogen receptors nucleotide-binding oligomerization domain-containing proteins NOD1 and NOD2 requires receptor interacting kinase 2 (RIPK2), an adaptor kinase that can be targeted for the treatment of various inflammatory diseases. However, the molecular mechanisms of how RIPK2 contributes to NOD signaling are not completely understood. We generated FLAG-tagged RIPK2 knock-in mice using CRISPR/Cas9 technology to study NOD signaling mechanisms at the endogenous level. Using cells from these mice, we were able to generate a detailed map of post-translational modifications on RIPK2. Similar to other reports, we did not detect ubiquitination of RIPK2 lysine 209 during NOD2 signaling. However, using site-directed mutagenesis we identified a new regulatory region on RIPK2, which dictates the crucial interaction with the E3 ligase XIAP and downstream signaling outcomes. © 2020 The Authors
Single-layer vs double-layer uterine closure during cesarean delivery:3-year follow-up of a randomized controlled trial (2Close study)
Background: The rising rate of cesarean deliveries has led to an increased incidence of long long-term complications, including niche formation in the uterine scar. Niche development is associated with various gynecologic complaints and complications in subsequent pregnancies, such as uterine rupture and placenta accreta spectrum disorders. Although uterine closure technique is considered a potential risk factor for niche development, consensus on the optimal technique remains elusive. Objective: We aimed to evaluate the effect of single-layer vs double-layer closure of the uterine incision on live birth rate at a 3-year follow-up with secondary objectives focusing on gynecologic, fertility, and obstetrical outcomes at the same follow-up. Study Design: A multicenter, double-blind, randomized controlled trial was performed at 32 hospitals in the Netherlands. Women ≥18 years old undergoing a first cesarean delivery were randomly assigned (1:1) to receive either single-layer or double-layer closure of the uterine incision. The primary outcome of the long-term follow-up was the live birth rate; with secondary outcomes, including pregnancy rate, the need for fertility treatment, mode of delivery, and obstetrical and gynecologic complications. This trial is registered on the International Clinical Trials Registry Platform www.who.int (NTR5480; trial finished). Results: Between 2016 and 2018, the 2Close study randomly assigned 2292 women, with 830 of 1144 and 818 of 1148 responding to the 3-year questionnaire in the single-layer and double-layer closure. No differences were observed in live birth rates; also there were no differences in pregnancy rate, need for fertility treatments, mode of delivery, or uterine ruptures in subsequent pregnancies. High rates of gynecologic symptoms, including spotting (30%–32%), dysmenorrhea (47%–49%), and sexual dysfunction (Female Sexual Function Index score, 23) are reported in both groups. Conclusion: The study did not demonstrate the superiority of double-layer closure over single-layer closure in terms of reproductive outcomes after a first cesarean delivery. This challenges the current recommendation favoring double-layer closure, and we propose that surgeons can choose their preferred technique. Furthermore, the high risk of gynecologic symptoms after a cesarean delivery should be discussed with patients.</p
Granulovirus PK-1 kinase activity relies on a side-to-side dimerization mode centered on the regulatory αC helix
The life cycle of Baculoviridae family insect viruses depends on the viral protein kinase, PK-1, to phosphorylate the regulatory protein, p6.9, to induce baculoviral genome release. Here, we report the crystal structure of Cydia pomenella granulovirus PK-1, which, owing to its likely ancestral origin among host cell AGC kinases, exhibits a eukaryotic protein kinase fold. PK-1 occurs as a rigid dimer, where an antiparallel arrangement of the αC helices at the dimer core stabilizes PK-1 in a closed, active conformation. Dimerization is facilitated by C-lobe:C-lobe and N-lobe:N-lobe interactions between protomers, including the domain-swapping of an N-terminal helix that crowns a contiguous β-sheet formed by the two N-lobes. PK-1 retains a dimeric conformation in solution, which is crucial for catalytic activity. Our studies raise the prospect that parallel, side-to-side dimeric arrangements that lock kinase domains in a catalytically-active conformation could function more broadly as a regulatory mechanism among eukaryotic protein kinases
Comparison and evaluation of experimental mediastinitis models: precolonized foreign body implants and bacterial suspension inoculation seems promising
BACKGROUND: Post-sternotomy mediastinitis (PSM) is a devastating surgical complication affecting 1–3% of patients that undergo cardiac surgery. Staphylococcus aureus is one of the most commonly encountered bacterial pathogen cultured from mediastinal samples obtained from patients with PSM. A component of the membrane of the gram positive bacteria, lipoteichoic acid, stimulates the blood monocytes and macrophages to secrete cytokines, radicals and nitrogen species leading to oxido-inflammatory damage. This seems to be responsible for the high mortality rate in PSM. For the evaluation of the pathogenesis of infection or for the investigation of alternative treatment models in infection, no standard model of mediastinitis seems to be available. In this study, we evaluated four mediastinitis models in rats. METHODS: The rats were divided into four groups to form different infection models. Group A: A suspension of 1 × 10(7 )colony-forming units Staphylococcus aureus in 0,5 mL was inoculated from the right second intercostal space into the mediastinum. Group B: A hole was created in the right second intercostal space and a piece of stainless-steel implant with a length of 0.5 cm was inserted into the mediastinum and a suspension of 1 × 10(7 )cfu bacteria in 0,5 mL was administered via the tail vein. Group C: Precolonized stainless-steel implant was inserted into the mediastinum. Group D: Precolonized stainless-steel implant was inserted into the mediastinum and the bacteria suspension was also injected into the mediastinum. On the 10(th )day, rats were sacrificed and the extension of infection in the mediastenae was evaluated by quantitative cultures. Myeloperoxidase activity (MPO) and malondialdehyde (MDA) levels were determined in the sera to evaluate the neutrophil activation and assess the inflammatory oxidation. RESULTS: The degree of infection in group C and D were 83.3% and 100% respectively (P < 0.001). MDA levels were significantly higher in these two groups than the others (P < 0.001). CONCLUSION: Infected implants and high bacterial concentration administration were the two important components that played a significant role in the outcome of a successful infection in mediastinum in a rat model
MRSA prevalence in european healthcare settings: a review
<p>Abstract</p> <p>Background</p> <p>During the past two decades, methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) has become increasingly common as a source of nosocomial infections. Most studies of MRSA surveillance were performed during outbreaks, so that results are not applicable to settings in which MRSA is endemic. This paper gives an overview of MRSA prevalence in hospitals and other healthcare institutions in non-outbreak situations in Western Europe.</p> <p>Methods</p> <p>A keyword search was conducted in the Medline database (2000 through June 2010). Titles and abstracts were screened to identify studies on MRSA prevalence in patients in non-outbreak situations in European healthcare facilities. Each study was assessed using seven quality criteria (outcome definition, time unit, target population, participants, observer bias, screening procedure, swabbing sites) and categorized as 'good', 'fair', or 'poor'.</p> <p>Results</p> <p>31 observational studies were included in the review. Four of the studies were of good quality. Surveillance screening of MRSA was performed in long-term care (11 studies) and acute care (20 studies). Prevalence rates varied over a wide range, from less than 1% to greater than 20%. Prevalence in the acute care and long-term care settings was comparable. The prevalence of MRSA was expressed in various ways - the percentage of MRSA among patients (range between 1% and 24%), the percentage of MRSA among <it>S. aureus </it>isolates (range between 5% and 54%), and as the prevalence density (range between 0.4 and 4 MRSA cases per 1,000 patient days). The screening policy differed with respect to time points (on admission or during hospital stay), selection criteria (all admissions or patients at high risk for MRSA) and anatomical sampling sites.</p> <p>Conclusions</p> <p>This review underlines the methodological differences between studies of MRSA surveillance. For comparisons between different healthcare settings, surveillance methods and outcome calculations should be standardized.</p
JAK2 V617F Constitutive Activation Requires JH2 Residue F595: A Pseudokinase Domain Target for Specific Inhibitors
The JAK2 V617F mutation present in over 95% of Polycythemia Vera patients and in 50% of Essential Thrombocythemia and Primary Myelofibrosis patients renders the kinase constitutively active. In the absence of a three-dimensional structure for the full-length protein, the mechanism of activation of JAK2 V617F has remained elusive. In this study, we used functional mutagenesis to investigate the involvement of the JH2 αC helix in the constitutive activation of JAK2 V617F. We show that residue F595, located in the middle of the αC helix of JH2, is indispensable for the constitutive activity of JAK2 V617F. Mutation of F595 to Ala, Lys, Val or Ile significantly decreases the constitutive activity of JAK2 V617F, but F595W and F595Y are able to restore it, implying an aromaticity requirement at position 595. Substitution of F595 to Ala was also able to decrease the constitutive activity of two other JAK2 mutants, T875N and R683G, as well as JAK2 K539L, albeit to a lower extent. In contrast, the F595 mutants are activated by erythropoietin-bound EpoR. We also explored the relationship between the dimeric conformation of EpoR and several JAK2 mutants. Since residue F595 is crucial to the constitutive activation of JAK2 V617F but not to initiation of JAK2 activation by cytokines, we suggest that small molecules that target the region around this residue might specifically block oncogenic JAK2 and spare JAK2 wild-type
Analysis of jak2 catalytic function by peptide microarrays: The role of the JH2 domain and V617F mutation
Janus kinase 2 (JAK2) initiates signaling from several cytokine receptors and is required for biological responses such as erythropoiesis. JAK2 activity is controlled by regulatory proteins such as Suppressor of Cytokine Signaling (SOCS) proteins and protein tyrosine phosphatases. JAK2 activity is also intrinsically controlled by regulatory domains, where the pseudokinase (JAK homology 2, JH2) domain has been shown to play an essential role. The physiological role of the JH2 domain in the regulation of JAK2 activity was highlighted by the discovery of the acquired missense point mutation V617F in myeloproliferative neoplasms (MPN). Hence, determining the precise role of this domain is critical for understanding disease pathogenesis and design of new treatment modalities. Here, we have evaluated the effect of inter-domain interactions in kinase activity and substrate specificity. By using for the first time purified recombinant JAK2 proteins and a novel peptide micro-array platform, we have determined initial phosphorylation rates and peptide substrate preference for the recombinant kinase domain (JH1) of JAK2, and two constructs comprising both the kinase and pseudokinase domains (JH1-JH2) of JAK2. The data demonstrate that (i) JH2 drastically decreases the activity of the JAK2 JH1 domain, (ii) JH2 increased the Kmfor ATP (iii) JH2 modulates the peptide preference of JAK2 (iv) the V617F mutation partially releases this inhibitory mechanism but does not significantly affect substrate preference or Kmfor ATP. These results provide the biochemical basis for understanding the interaction between the kinase and the pseudokinase domain of JAK2 and identify a novel regulatory role for the JAK2 pseudokinase domain. Additionally, this method can be used to identify new regulatory mechanisms for protein kinases that provide a better platform for designing specific strategies for therapeutic approaches
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