126 research outputs found
Determining the longitudinal validity and meaningful differences in HRQL of the PedsQL™ Sickle Cell Disease Module.
BACKGROUND: Detecting change in health status over time and ascertaining meaningful changes are critical elements when using health-related quality of life (HRQL) instruments to measure patient-centered outcomes. The PedsQL™ Sickle Cell Disease module, a disease specific HRQL instrument, has previously been shown to be valid and reliable. Our objectives were to determine the longitudinal validity of the PedsQL™ Sickle Cell Disease module and the change in HRQL that is meaningful to patients.
METHODS: An ancillary study was conducted utilizing a multi-center prospective trial design. Children ages 4-21 years with sickle cell disease admitted to the hospital for an acute painful vaso-oclusive crisis were eligible. Children completed HRQL assessments at three time points (in the Emergency Department, one week post-discharge, and at return to baseline (One to three months post-discharge). The primary outcome was change in HRQL score. Both distribution (effect size, standard error of measurement (SEM)) and anchor (global change assessment) based methods were used to determine the longitudinal validity and meaningful change in HRQL. Changes in HRQL meaningful to patients were identified by anchoring the change scores to the patient\u27s perception of global improvement in pain.
RESULTS: Moderate effect sizes (0.20-0.80) were determined for all domains except the Communication I and Cognitive Fatigue domains. The value of 1 SEM varied from 3.8-14.6 across all domains. Over 50% of patients improved by at least 1 SEM in Total HRQL score. A HRQL change score of 7-10 in the pain domains represented minimal perceived improvement in HRQL and a HRQL change score of 18 or greater represented moderate to large improvement.
CONCLUSIONS: The PedsQL™ Sickle Cell Disease Module is responsive to changes in HRQL in patients experiencing acute painful vaso-occlusive crises. The study data establish longitudinal validity and meaningful change parameters for the PedsQL™ Sickle Cell Disease Module.
TRIAL REGISTRATION: ClinicalTrials.gov (study identifier: NCT01197417 ). Date of registration: 08/30/2010
A Recurrent Silent Mutation Implicates fecA in Ethanol Tolerance by Escherichia coli.
BACKGROUND: An issue associated with efficient bioethanol production is the fact that the desired product is toxic to the biocatalyst. Among other effects, ethanol has previously been found to influence the membrane of E. coli in a dose-dependent manner and induce changes in the lipid composition of the plasma membrane. We describe here the characterization of a collection of ethanol-tolerant strains derived from the ethanologenic Escherichia coli strain FBR5.
RESULTS: Membrane permeability assays indicate that many of the strains in the collection have alterations in membrane permeability and/or responsiveness of the membrane to environmental changes such as temperature shifts or ethanol exposure. However, analysis of the strains by gas chromatography and mass spectrometry revealed no qualitative changes in the acyl chain composition of membrane lipids in response to ethanol or temperature. To determine whether these strains contain any mutations that might contribute to ethanol tolerance or changes in membrane permeability, we sequenced the entire genome of each strain. Unexpectedly, none of the strains displayed mutations in genes known to control membrane lipid synthesis, and a few strains carried no mutations at all. Interestingly, we found that four independently-isolated strains acquired an identical C → A (V244 V) silent mutation in the ferric citrate transporter gene fecA. Further, we demonstrated that either a deletion of fecA or over-expression of fecA can confer increased ethanol survival, suggesting that any misregulation of fecA expression affects the cellular response to ethanol.
CONCLUSIONS: The fact that no mutations were observed in several ethanol-tolerant strains suggested that epigenetic mechanisms play a role in E. coli ethanol tolerance and membrane permeability. Our data also represent the first direct phenotypic evidence that the fecA gene plays a role in ethanol tolerance. We propose that the recurring silent mutation may exert an effect on phenotype by altering RNA-mediated regulation of fecA expression
Global Burden of Sickle Cell Anaemia in Children under Five, 2010-2050: Modelling Based on Demographics, Excess Mortality, and Interventions
The global burden of sickle cell anaemia (SCA) is set to rise as a consequence of improved survival in high-prevalence low- and middle-income countries and population migration to higher-income countries. The host of quantitative evidence documenting these changes has not been assembled at the global level. The purpose of this study is to estimate trends in the future number of newborns with SCA and the number of lives that could be saved in under-five children with SCA by the implementation of different levels of health interventions.First, we calculated projected numbers of newborns with SCA for each 5-y interval between 2010 and 2050 by combining estimates of national SCA frequencies with projected demographic data. We then accounted for under-five mortality (U5m) projections and tested different levels of excess mortality for children with SCA, reflecting the benefits of implementing specific health interventions for under-five patients in 2015, to assess the number of lives that could be saved with appropriate health care services. The estimated number of newborns with SCA globally will increase from 305,800 (confidence interval [CI]: 238,400-398,800) in 2010 to 404,200 (CI: 242,500-657,600) in 2050. It is likely that Nigeria (2010: 91,000 newborns with SCA [CI: 77,900-106,100]; 2050: 140,800 [CI: 95,500-200,600]) and the Democratic Republic of the Congo (2010: 39,700 [CI: 32,600-48,800]; 2050: 44,700 [CI: 27,100-70,500]) will remain the countries most in need of policies for the prevention and management of SCA. We predict a decrease in the annual number of newborns with SCA in India (2010: 44,400 [CI: 33,700-59,100]; 2050: 33,900 [CI: 15,900-64,700]). The implementation of basic health interventions (e.g., prenatal diagnosis, penicillin prophylaxis, and vaccination) for SCA in 2015, leading to significant reductions in excess mortality among under-five children with SCA, could, by 2050, prolong the lives of 5,302,900 [CI: 3,174,800-6,699,100] newborns with SCA. Similarly, large-scale universal screening could save the lives of up to 9,806,000 (CI: 6,745,800-14,232,700) newborns with SCA globally, 85% (CI: 81%-88%) of whom will be born in sub-Saharan Africa. The study findings are limited by the uncertainty in the estimates and the assumptions around mortality reductions associated with interventions.Our quantitative approach confirms that the global burden of SCA is increasing, and highlights the need to develop specific national policies for appropriate public health planning, particularly in low- and middle-income countries. Further empirical collaborative epidemiological studies are vital to assess current and future health care needs, especially in Nigeria, the Democratic Republic of the Congo, and India
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Mapping Antimicrobial Stewardship in Undergraduate Medical, Dental, Pharmacy, Nursing and Veterinary Education in the United Kingdom.
OBJECTIVES: To investigate the teaching of antimicrobial stewardship (AS) in undergraduate healthcare educational degree programmes in the United Kingdom (UK). PARTICIPANTS AND METHODS: Cross-sectional survey of undergraduate programmes in human and veterinary medicine, dentistry, pharmacy and nursing in the UK. The main outcome measures included prevalence of AS teaching; stewardship principles taught; estimated hours apportioned; mode of content delivery and teaching strategies; evaluation methodologies; and frequency of multidisciplinary learning. RESULTS: 80% (112/140) of programmes responded adequately. The majority of programmes teach AS principles (88/109, 80.7%). 'Adopting necessary infection prevention and control precautions' was the most frequently taught principle (83/88, 94.3%), followed by 'timely collection of microbiological samples for microscopy, culture and sensitivity' (73/88, 82.9%) and 'minimisation of unnecessary antimicrobial prescribing' (72/88, 81.8%). The 'use of intravenous administration only to patients who are severely ill, or unable to tolerate oral treatment' was reported in ~50% of courses. Only 32/88 (36.3%) programmes included all recommended principles. DISCUSSION: Antimicrobial stewardship principles are included in most undergraduate healthcare and veterinary degree programmes in the UK. However, future professionals responsible for using antimicrobials receive disparate education. Education may be boosted by standardisation and strengthening of less frequently discussed principles
Health-related quality-of-life measures for long-term follow-up in children after major trauma
Objective: Our objective was to review measures of health-related quality of life (HRQL) for long-term follow
up in children after major trauma and to determine the measures that are suitable for a large age range, reliable
and valid, and cover a substantial amount of the domains of functioning using the International Classification of Functioning, Disability, and Health (ICF) of the World Health Organization (WHO).
Methods: The Medline and EMBASE databases were searched in all years up to October 2007 for generic HRQL
measures suitable for children aged 5-18 years old and validated in English or Dutch. Measures were reviewed with
respect to the age range for which the measure was suitable and reliability, validity, and content related to the ICF.
Results: The search resulted in 1,235 hits and 21 related articles. Seventy-nine papers met the inclusion criteria, describing in total 14 measures: Child Health and Illness Profile Adolescent and Child Edition (CHIP-AE/CE), Child Health Questionnaire Child and Parent Forms (CHQCF87/PF50/PF28), DISABKIDS, Functional Status II (FS II)(R), Health Utilities Index Mark 2 (HUI 2), KIDSCREEN 52/27, KINDL, Pediatric Quality of Life
Inventory (PedsQL), TNO Institute of Prevention and Health and the Leiden University Hospital (TNO-AZL),
TNO-AZL Children’s Quality Of Life (TACQOL), and Youth Quality of Life Instrument-Research Version
(YQOL-R). Measures that were suitable for a large age range were CHQ-PF50/PF28, DISABKIDS, FS II(R), HUI
2, KIDSCREEN, PedsQL, and TACQOL. All measures had moderate to good psychometric properties, except for
CHQ-PF50/PF28, KINDL, and TACQOL, which had either low internal consistency or bad test-retest reliability.
The measures that covered more than six chapters of the ICF domains were CHIP-AE/CE, CHQ-CF87/PF50, DISABKIDS,
KIDSCREEN-52, PedsQL, and TACQOL.
Conclusions: DISABKIDS, KIDSCREEN 52, and Peds-QL are suitable for long-term follow-up measurement of
HRQL in children after major trauma. They cover a large age range, have good psychometric properties, and cover
the ICF substantially
Extracellular Fibrils of Pathogenic Yeast Cryptococcus gattii Are Important for Ecological Niche, Murine Virulence and Human Neutrophil Interactions
Cryptococcus gattii, an emerging fungal pathogen of humans and animals, is found on a variety of trees in tropical and temperate regions. The ecological niche and virulence of this yeast remain poorly defined. We used Arabidopsis thaliana plants and plant-derived substrates to model C. gattii in its natural habitat. Yeast cells readily colonized scratch-wounded plant leaves and formed distinctive extracellular fibrils (40–100 nm diameter ×500–3000 nm length). Extracellular fibrils were observed on live plants and plant-derived substrates by scanning electron microscopy (SEM) and by high voltage- EM (HVEM). Only encapsulated yeast cells formed extracellular fibrils as a capsule-deficient C. gattii mutant completely lacked fibrils. Cells deficient in environmental sensing only formed disorganized extracellular fibrils as apparent from experiments with a C. gattii STE12α mutant. C. gattii cells with extracellular fibrils were more virulent in murine model of pulmonary and systemic cryptococcosis than cells lacking fibrils. C. gattii cells with extracellular fibrils were also significantly more resistant to killing by human polymorphonuclear neutrophils (PMN) in vitro even though these PMN produced elaborate neutrophil extracellular traps (NETs). These observations suggest that extracellular fibril formation could be a structural adaptation of C. gattii for cell-to-cell, cell-to-substrate and/or cell-to- phagocyte communications. Such ecological adaptation of C. gattii could play roles in enhanced virulence in mammalian hosts at least initially via inhibition of host PMN– mediated killing
Characterization of Yeast Extracellular Vesicles: Evidence for the Participation of Different Pathways of Cellular Traffic in Vesicle Biogenesis
Background: Extracellular vesicles in yeast cells are involved in the molecular traffic across the cell wall. In yeast pathogens, these vesicles have been implicated in the transport of proteins, lipids, polysaccharide and pigments to the extracellular space. Cellular pathways required for the biogenesis of yeast extracellular vesicles are largely unknown. Methodology/Principal Findings: We characterized extracellular vesicle production in wild type (WT) and mutant strains of the model yeast Saccharomyces cerevisiae using transmission electron microscopy in combination with light scattering analysis, lipid extraction and proteomics. WT cells and mutants with defective expression of Sec4p, a secretory vesicleassociated Rab GTPase essential for Golgi-derived exocytosis, or Snf7p, which is involved in multivesicular body (MVB) formation, were analyzed in parallel. Bilayered vesicles with diameters at the 100–300 nm range were found in extracellular fractions from yeast cultures. Proteomic analysis of vesicular fractions from the cells aforementioned and additional mutants with defects in conventional secretion pathways (sec1-1, fusion of Golgi-derived exocytic vesicles with the plasm
The Role of Information Provision in Economic Evaluations of Newborn Bloodspot Screening: A Systematic Review
Silencing of Vlaro2 for chorismate synthase revealed that the phytopathogen Verticillium longisporum induces the cross-pathway control in the xylem
The first leaky auxotrophic mutant for aromatic amino acids of the near-diploid fungal plant pathogen Verticillium longisporum (VL) has been generated. VL enters its host Brassica napus through the roots and colonizes the xylem vessels. The xylem contains little nutrients including low concentrations of amino acids. We isolated the gene Vlaro2 encoding chorismate synthase by complementation of the corresponding yeast mutant strain. Chorismate synthase produces the first branch point intermediate of aromatic amino acid biosynthesis. A novel RNA-mediated gene silencing method reduced gene expression of both isogenes by 80% and resulted in a bradytrophic mutant, which is a leaky auxotroph due to impaired expression of chorismate synthase. In contrast to the wild type, silencing resulted in increased expression of the cross-pathway regulatory gene VlcpcA (similar to cpcA/GCN4) during saprotrophic life. The mutant fungus is still able to infect the host plant B. napus and the model Arabidopsis thaliana with reduced efficiency. VlcpcA expression is increased in planta in the mutant and the wild-type fungus. We assume that xylem colonization requires induction of the cross-pathway control, presumably because the fungus has to overcome imbalanced amino acid supply in the xylem
Sub-Telomere Directed Gene Expression during Initiation of Invasive Aspergillosis
Aspergillus fumigatus is a common mould whose spores are a
component of the normal airborne flora. Immune dysfunction permits developmental
growth of inhaled spores in the human lung causing aspergillosis, a significant
threat to human health in the form of allergic, and life-threatening invasive
infections. The success of A. fumigatus as a pathogen is unique
among close phylogenetic relatives and is poorly characterised at the molecular
level. Recent genome sequencing of several Aspergillus species
provides an exceptional opportunity to analyse fungal virulence attributes
within a genomic and evolutionary context. To identify genes preferentially
expressed during adaptation to the mammalian host niche, we generated multiple
gene expression profiles from minute samplings of A. fumigatus
germlings during initiation of murine infection. They reveal a highly
co-ordinated A. fumigatus gene expression programme, governing
metabolic and physiological adaptation, which allows the organism to prosper
within the mammalian niche. As functions of phylogenetic conservation and
genetic locus, 28% and 30%, respectively, of the
A. fumigatus subtelomeric and lineage-specific gene
repertoires are induced relative to laboratory culture, and physically clustered
genes including loci directing pseurotin, gliotoxin and siderophore biosyntheses
are a prominent feature. Locationally biased A. fumigatus gene
expression is not prompted by in vitro iron limitation, acid,
alkaline, anaerobic or oxidative stress. However, subtelomeric gene expression
is favoured following ex vivo neutrophil exposure and in
comparative analyses of richly and poorly nourished laboratory cultured
germlings. We found remarkable concordance between the A.
fumigatus host-adaptation transcriptome and those resulting from
in vitro iron depletion, alkaline shift, nitrogen
starvation and loss of the methyltransferase LaeA. This first transcriptional
snapshot of a fungal genome during initiation of mammalian infection provides
the global perspective required to direct much-needed diagnostic and therapeutic
strategies and reveals genome organisation and subtelomeric diversity as
potential driving forces in the evolution of pathogenicity in the genus
Aspergillus
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