bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity-Related Conformational Changes in
d,d
-Carboxypeptidases Revealed by
In Vivo
Periplasmic Förster Resonance Energy Transfer Assay in
Escherichia coli
Authors: Meiresonne Nils Y. , van der Ploeg René , Hink Mark A. , den Blaauwen Tanneke 
Published: September 2017

ABSTRACT

One of the mechanisms of β-lactam antibiotic resistance requires the activity of
d,d
-carboxypeptidases (
d,d
-CPases) involved in peptidoglycan (PG) synthesis, making them putative targets for new antibiotic development. The activity of PG-synthesizing enzymes is often correlated with their association with other proteins. The PG layer is maintained in the periplasm between the two membranes of the Gram-negative cell envelope. Because no methods existed to detect
in vivo
interactions in this compartment, we have developed and validated a Förster resonance energy transfer assay. Using the fluorescent-protein donor-acceptor pair mNeonGreen-mCherry, periplasmic protein interactions were detected in fixed and in living bacteria, in single samples or in plate reader 96-well format. We show that the
d,d
-CPases PBP5, PBP6a, and PBP6b of
Escherichia coli
change dimer conformation between resting and active states. Complementation studies and changes in localization suggest that these
d,d
-CPases are not redundant but that their balanced activity is required for robust PG synthesis.

IMPORTANCE
The periplasmic space between the outer and the inner membrane of Gram-negative bacteria contains many essential regulatory, transport, and cell wall-synthesizing and -hydrolyzing proteins. To date, no assay is available to determine protein interactions in this compartment. We have developed a periplasmic protein interaction assay for living and fixed bacteria in single samples or 96-well-plate format. Using this assay, we were able to demonstrate conformation changes related to the activity of proteins that could not have been detected by any other living-cell method available. The assay uniquely expands our toolbox for antibiotic screening and mode-of-action studies.
Binding of NAD
+
-Glycohydrolase to Streptolysin O Stabilizes Both Toxins and Promotes Virulence of Group A
Streptococcus
Authors: Velarde Jorge J. , O’Seaghdha Maghnus , Baddal Buket , Bastiat-Sempe Benedicte , Wessels Michael R. 
Published: September 2017

ABSTRACT

The globally dominant, invasive M1T1 strain of group A
Streptococcus
(GAS) harbors polymorphisms in the promoter region of an operon that contains the genes encoding streptolysin O (SLO) and NAD
+
-glycohydrolase (NADase), resulting in high-level expression of these toxins. While both toxins have been shown experimentally to contribute to pathogenesis, many GAS isolates lack detectable NADase activity. DNA sequencing of such strains has revealed that reduced or absent enzymatic activity can be associated with a variety of point mutations in
nga
, the gene encoding NADase; a commonly observed polymorphism associated with near-complete abrogation of activity is a substitution of aspartic acid for glycine at position 330 (G330D). However,
nga
has not been observed to contain early termination codons or mutations that would result in a truncated protein, even when the gene product contains missense mutations that abrogate enzymatic activity. It has been suggested that NADase that lacks NAD-glycohydrolase activity retains an as-yet-unidentified inherent cytotoxicity to mammalian cells and thus is still a potent virulence factor. We now show that expression of NADase, either enzymatically active or inactive, augments SLO-mediated toxicity for keratinocytes. In culture supernatants, SLO and NADase are mutually interdependent for protein stability. We demonstrate that the two proteins interact in solution and that both the translocation domain and catalytic domain of NADase are required for maximal binding between the two toxins. We conclude that binding of NADase to SLO stabilizes both toxins, thereby enhancing GAS virulence.

IMPORTANCE
The global increase in invasive GAS infections in the 1980s was associated with the emergence of an M1T1 clone that harbors a 36-kb pathogenicity island, which codes for increased expression of toxins SLO and NADase. Polymorphisms in NADase that render it catalytically inactive can be detected in clinical isolates, including invasive strains. However, such isolates continue to produce full-length NADase. The rationale for this observation is not completely understood. This study characterizes the binding interaction between NADase and SLO and reports that the expression of each toxin is crucial for maximal expression and stability of the other. By this mechanism, the presence of both toxins increases toxicity to keratinocytes and is predicted to enhance GAS survival in the human host. These observations provide an explanation for conservation of full-length NADase expression even when it lacks enzymatic activity and suggest a critical role for binding of NADase to SLO in GAS pathogenesis.
Gene Expression in
Leishmania
Is Regulated Predominantly by Gene Dosage
Authors: Iantorno Stefano A. , Durrant Caroline , Khan Asis , Sanders Mandy J. , Beverley Stephen M. , Warren Wesley C. , Berriman Matthew , Sacks David L. , Cotton James A. , Grigg Michael E. 
Published: September 2017

ABSTRACT

Leishmania tropica
, a unicellular eukaryotic parasite present in North and East Africa, the Middle East, and the Indian subcontinent, has been linked to large outbreaks of cutaneous leishmaniasis in displaced populations in Iraq, Jordan, and Syria. Here, we report the genome sequence of this pathogen and 7,863 identified protein-coding genes, and we show that the majority of clinical isolates possess high levels of allelic diversity, genetic admixture, heterozygosity, and extensive aneuploidy. By utilizing paired genome-wide high-throughput DNA sequencing (DNA-seq) with RNA-seq, we found that gene dosage, at the level of individual genes or chromosomal “somy” (a general term covering disomy, trisomy, tetrasomy, etc.), accounted for greater than 85% of total gene expression variation in genes with a 2-fold or greater change in expression. High gene copy number variation (CNV) among membrane-bound transporters, a class of proteins previously implicated in drug resistance, was found for the most highly differentially expressed genes. Our results suggest that gene dosage is an adaptive trait that confers phenotypic plasticity among natural
Leishmania
populations by rapid down- or upregulation of transporter proteins to limit the effects of environmental stresses, such as drug selection.

IMPORTANCE
Leishmania
is a genus of unicellular eukaryotic parasites that is responsible for a spectrum of human diseases that range from cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL) to life-threatening visceral leishmaniasis (VL). Developmental and strain-specific gene expression is largely thought to be due to mRNA message stability or posttranscriptional regulatory networks for this species, whose genome is organized into polycistronic gene clusters in the absence of promoter-mediated regulation of transcription initiation of nuclear genes. Genetic hybridization has been demonstrated to yield dramatic structural genomic variation, but whether such changes in gene dosage impact gene expression has not been formally investigated. Here we show that the predominant mechanism determining transcript abundance differences (>85%) in
Leishmania tropica
is that of gene dosage at the level of individual genes or chromosomal somy.
Lactobacillus: the not so friendly bacteria
Authors: Pararajasingam Abirami , Uwagwu Juliet 
Published: September 2017

We present a 65-year-old diabetic patient with a complex liver abscess and bacteraemia fromLactobacillus paracasei. The abscess resulted in a prolonged hospital stay due to ongoing sepsis despite ultrasound-guided drainage and broad-spectrum antibiotics. Furthermore, the patient developed several secondary complications including a right-sided pleural effusion, an inferior vena cava thrombus and septic lung emboli. The abscess was eventually managed successfully with a prolonged course of antibiotics and multiple ultrasound-guided drainage procedures.To our knowledge, this is the first reported case of probiotic consumption, confirmed by strain identification, as the likely source of a liver abscess. Probiotic products have been widely used for many years and are advocated to the general public for their health benefits with no warning of side effects. Lactobacilli are one group of bacteria commonly used in these products. Although rare, complications have been reported. Susceptible patients, such as those who are immunocompromised, should be advised against excessive consumption.
Protocol for a systematic review of instruments for the assessment of quality of life and well-being in children and adolescents with cerebral palsy
Authors: Mpundu-Kaambwa Christine , Chen Gang , Huynh Elisabeth , Russo Remo , Ratcliffe Julie 
Published: September 2017

IntroductionCerebral palsy is the most common cause of physical disability in children and adolescents and is associated with impairments that may reduce the quality of life (QOL) of this population. Patient-reported outcome measures (PROMs) can facilitate the assessment of the effect of disease and treatment on QOL, from a patient viewpoint. The purpose of this systematic review is to identify PROMs that are used to measure QOL and subjective well-being (SWB) outcomes in young people with cerebral palsy and to evaluate the suitability of these PROMs for application in economic evaluations within this population.Methods and analysisMEDLINE, Scopus, the Cochrane Library, Web of Science Core Collection, EconLit, PsycINFO, CINAHL, EMBASE and Informit will be systematically searched from inception to date of search. Published peer-reviewed, English-language articles reporting PROMs measuring QOL or SWB outcomes in children and adolescents with cerebral palsy will be included. One reviewer will conduct the initial search and screen titles and abstracts for potentially eligible studies. The search will be performed in November 2017. To reduce the likelihood of reviewer selection bias, two other reviewers will independently screen a randomly selected subsample (10%) of the citations. Two reviewers will then retrieve full texts of potentially eligible studies and assess them against predefined inclusion criteria. The suitability of selected PROMs for use in economic evaluations of young people with cerebral palsy will be assessed using the International Society of Quality of Life Research recommended Minimum Standards and the Patient-Centered Outcomes and Comparative Effectiveness Research checklist. A narrative synthesis of extracted data will be presented including study descriptive data, PROMs measurement properties, settings in which they were applied and the valuation methods. Recommendations for practice on the selection of PROMs for use in economic evaluations of children and adolescents with cerebral palsy will be presented.Ethics and disseminationEthical approval is not required as the proposed systematic review will not use primary data. The results of this study will be widely disseminated through publication in a peer-reviewed journal and conference presentation(s).Systematic review registration numberInternational Prospective Register of Systematic Reviews number: CRD42016049746.
Neck circumference and clustered cardiovascular risk factors in children and adolescents: cross-sectional study
Authors: Castro-Piñero José , Delgado-Alfonso Alvaro , Gracia-Marco Luis , Gómez-Martínez Sonia , Esteban-Cornejo Irene , Veiga Oscar L , Marcos Ascensión , Segura-Jiménez Víctor 
Published: September 2017

ObjectiveEarly detection of cardiovascular disease (CVD) risk factors, such as obesity, is crucial to prevent adverse long-term effects on individuals’ health. Therefore, the aims were: (1) to explore the robustness of neck circumference (NC) as a predictor of CVD and examine its association with numerous anthropometric and body composition indices and (2) to release sex and age-specific NC cut-off values to classify youths as overweight/obese.DesignCross-sectional study.Setting23 primary schools and 17 secondary schools from Spain.Participants2198 students (1060 girls), grades 1–4 and 7–10.MeasuresPubertal development, anthropometric and body composition indices, systolic and diastolic blood pressure (SBP and DBP, respectively), cardiorespiratory fitness, blood sampling triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), glucose and inflammatory markers. Homoeostasis model assessment (HOMA-IR) and cluster of CVD risk factors were calculated.ResultsNC was positively correlated with all anthropometric and body composition indices. NC was negatively associated with maximum oxygen consumption (R2=0.231, p<0.001 for boys; R2=0.018, p<0.001 for girls) and positively associated with SBP, DBP, TC/HDL-c, TG, HOMA, complement factors C-3 and C-4, leptin, adiponectin and clustered CVD risk factor in both sexes (R2from 0.035 to 0.353, p<0.01 for boys; R2from 0.024 to 0.215, p<0.001 for girls). Moreover, NC was positively associated with serum C reactive protein, LDL-c and visfatin only in boys (R2from 0.013 to 0.107, p<0.05).ConclusionNC is a simple, low-cost and practical screening tool of excess of upper body obesity and CVD risk factors in children and adolescents. Paediatricians can easily use it as a screening tool for overweight/obesity in children and adolescents. For this purpose, sex and age-specific thresholds to classify children and adolescents as normal weight or overweight/obese are provided.
A retrospective analysis of 34 potentially missed cases of female genital mutilation in the emergency department
Authors: Fawcett Richard John , Kernohan George 
Published: September 2017

ObjectivesTo discover if healthcare professionals working within an ED are able to make a diagnosis of female genital mutilation (FGM) in those patients who have previously undergone the procedure and report it as per UK law.DesignA retrospective analysis of patients’ notes who were assigned an FGM code during the period of May 2015 to August 2016.SettingSingle-centre, large UK major trauma centre offering a tertiary FGM clinic.ParticipantsAny woman coded during the study period as having undergone FGM.Primary outcomeNumber of FGM cases identified by the ED.Secondary outcomesMean age, presenting complaint, discharge diagnosis, genitourinary exam and defibulation status.Results34 patients were identified as having undergone FGM, 19 had previously attended ED and none had their FGM identified during their ED attendance. The age range of those identified was 23 to 40 years. None had undergone defibulation.ConclusionThis study demonstrates that the identification of FGM victims by an ED is very poor, and more work needs to be done to increase awareness of the subject by front-line staff.
Education and health and well-being: direct and indirect effects with multiple mediators and interactions with multiple imputed data in Stata
Authors: Sheikh Mashhood Ahmed , Abelsen Birgit , Olsen Jan Abel 
Published: September 2017

BackgroundPrevious methods for assessing mediation assume no multiplicative interactions. The inverse odds weighting (IOW) approach has been presented as a method that can be used even when interactions exist. The substantive aim of this study was to assess the indirect effect of education on health and well-being via four indicators of adult socioeconomic status (SES): income, management position, occupational hierarchy position and subjective social status.Methods8516 men and women from the Tromsø Study (Norway) were followed for 17 years. Education was measured at age 25–74 years, while SES and health and well-being were measured at age 42–91 years. Natural direct and indirect effects (NIE) were estimated using weighted Poisson regression models with IOW. Stata code is provided that makes it easy to assess mediation in any multiple imputed dataset with multiple mediators and interactions.ResultsLow education was associated with lower SES. Consequently, low SES was associated with being unhealthy and having a low level of well-being. The effect (NIE) of education on health and well-being is mediated by income, management position, occupational hierarchy position and subjective social status.ConclusionThis study contributes to the literature on mediation analysis, as well as the literature on the importance of education for health-related quality of life and subjective well-being. The influence of education on health and well-being had different pathways in this Norwegian sample.
Subacute endovascular recanalization of symptomatic cerebral artery occlusion: a propensity score-matched analysis
Authors: Lee Sang Hun , Suh Dae Chul , Cho Su Hee , Sheen Jae Jon , Lee Deok Hee , Kim Jong S 
Published: September 2017

BackgroundThe interval between the onset of cerebral vessel occlusion and recanalization has been shown to be an independent predictor of poor outcomes. However, endovascular recanalization of symptomatic cerebral vessel occlusion in the subacute period has not been well documented. We investigated the safety and efficacy of subacute recanalization of occluded cerebral vessels in patients with ischemic stroke or transient ischemic attacks (TIAs).MethodsBetween 2014 and 2015, 98 patients were admitted to the emergency room for ischemic stroke or TIA with a small infarct core, which was defined as modest early ischemic change on non-contrast CT or overt diffusion–perfusion mismatch. All patients underwent pre-transfemoral cerebral angiography and post-endovascular treatment. The patients were classified according to acute (onset-to-groin puncture time ≤6 hours) or subacute (onset-to-groin puncture time >6 hours) recanalization. Using propensity score analysis, recipients of acute and subacute recanalization underwent 1:1 matching.ResultsFollowing 1:1 propensity score matching, 32 patients who underwent acute and 32 who underwent subacute intra-arterial thrombolysis were matched. There were no significant differences in National Institutes of Health Stroke Scale at discharge, modified Rankin scale (mRS), the proportion of patients with an mRS value of 0–2, mortality at discharge, intracerebral bleeding, postprocedural infarct extension, newly detected infarction, and hyperintense acute reperfusion marker on follow-up images between the acute and subacute recanalization groups.ConclusionsIn selected patients with clinically unstable cerebral artery occlusions, a diffusion–perfusion mismatch and small CT lesions, subacute and acute recanalization has comparable safety and efficacy rates.
Epidural interlaminar injections in severe degenerative lumbar spine: fluoroscopy should not be a luxury
Authors: Filippiadis Dimitrios K , Rodt Thomas , Kitsou Maria-Chrysanthi , Batistaki Chrysanthi , Kelekis Nikolaos , Kostopanagiotou Georgia , Kelekis Alexis 
Published: September 2017

ObjectiveTo assess technical efficacy, accuracy, and safety of epidural (interlaminar) injections performed blindly in patients with a severely degenerated lumbar spine.MethodsOver 12 consecutive months, 138 patients with a severe degenerative lumbar spine underwent epidural (interlaminar) injection as therapy for low back pain and neuralgia. Patients had already undergone a blind epidural infiltration with minimum or no pain reduction. The session was repeated in the angiography suite. Patients were placed in the lateral decubitus position. The injection was performed without image guidance by an anaesthesiologist; the target level was defined before the beginning of the procedure. Once air resistance loss was felt it was presumed that the needle was inside the epidural space. Verification of needle position was performed by injection of 1–3 mL of iodinated contrast medium under fluoroscopy in a lateral projection.ResultsCorrect needle position inside the epidural space was documented in 82/138 cases (59.4%); unexpected extraepidural location was seen in 56/138 cases (40.6%). Target level was reached in 96/138 cases (69.6%); in 42/138 cases (30.4%) the needle was positioned in a non-target level. In 5/138 (3.6%) cases, there was inadvertent intradural position of the needle. Image guidance was subsequently used for correct positioning of the needle, which was feasible in all cases.ConclusionBlind interlaminar epidural injections lack the accuracy of exact needle location that imaging guidance offers in approximately 40% of cases, when there is difficult spine anatomy and the initial epidural approach has failed to provide pain relief. Image guidance for interlaminar epidural injection ensures accurate needle placement, enhancing the safety and efficacy of the procedure.
Stability of hand force production. I. Hand level control variables and multifinger synergies
Authors: Reschechtko Sasha , Latash Mark L. 
Published: September 2017

We combined the theory of neural control of movement with referent coordinates and the uncontrolled manifold hypothesis to explore synergies stabilizing the hand action in accurate four-finger pressing tasks. In particular, we tested a hypothesis on two classes of synergies, those among the four fingers and those within a pair of control variables, stabilizing hand action under visual feedback and disappearing without visual feedback. Subjects performed four-finger total force and moment production tasks under visual feedback; the feedback was later partially or completely removed. The “inverse piano” device was used to lift and lower the fingers smoothly at the beginning and at the end of each trial. These data were used to compute pairs of hypothetical control variables. Intertrial analysis of variance within the finger force space was used to quantify multifinger synergies stabilizing both force and moment. A data permutation method was used to quantify synergies among control variables. Under visual feedback, synergies in the spaces of finger forces and hypothetical control variables were found to stabilize total force. Without visual feedback, the subjects showed a force drift to lower magnitudes and a moment drift toward pronation. This was accompanied by disappearance of the four-finger synergies and strong attenuation of the control variable synergies. The indexes of the two types of synergies correlated with each other. The findings are interpreted within the scheme with multiple levels of abundant variables. NEW & NOTEWORTHY We extended the idea of hierarchical control with referent spatial coordinates for the effectors and explored two types of synergies stabilizing multifinger force production tasks. We observed synergies among finger forces and synergies between hypothetical control variables that stabilized performance under visual feedback but failed to stabilize it after visual feedback had been removed. Indexes of two types of synergies correlated with each other. The data suggest the existence of multiple mechanisms stabilizing motor actions.