2,670 research outputs found
Immunity to self co-generates regulatory T cells
Immune responses to self are kept in check by tolerance mechanisms, including suppression by regulatory T cells (Tregs). The defective generation of Tregs specific for self-antigens may lead to autoimmune disease. We identified a novel population of human CD4^+^ Tregs, characterized by high surface expression of CD52, which is co-generated in response to autoantigen. Blood CD4^+^CD52^hi^ T cells were generated preferentially in response to low-dose autoantigen and suppressed proliferation and interferon-[gamma] production by other T cells. Depletion of resting CD4^+^CD52^hi^ T cells enhanced the T-cell response to autoantigen. CD4^+^CD52^hi^ Tregs were neither derived from nor distinguished by markers of conventional resting CD4^+^CD25^+^ Tregs. In response to the pancreatic islet autoantigens glutamic acid decarboxylase, the generation of CD4^+^CD52^hi^ Tregs was impaired in individuals with and at-risk for type 1 diabetes, compared to healthy controls and individuals with type 2 diabetes. CD4^+^CD52^hi^ Tregs co-generated to self-antigen may therefore contribute to immune homeostasis and protect against autoimmune disease
Methylomic trajectories across human fetal brain development
Open access articleEpigenetic processes play a key role in orchestrating transcriptional regulation during development. The importance of DNA methylation in fetal brain development is highlighted by the dynamic expression of de novo DNA methyltransferases during the perinatal period and neurodevelopmental deficits associated with mutations in the methyl-CpG binding protein 2 (MECP2) gene. However, our knowledge about the temporal changes to the epigenome during fetal brain development has, to date, been limited. We quantified genome-wide patterns of DNA methylation at ∼ 400,000 sites in 179 human fetal brain samples (100 male, 79 female) spanning 23 to 184 d post-conception. We identified highly significant changes in DNA methylation across fetal brain development at >7% of sites, with an enrichment of loci becoming hypomethylated with fetal age. Sites associated with developmental changes in DNA methylation during fetal brain development were significantly underrepresented in promoter regulatory regions but significantly overrepresented in regions flanking CpG islands (shores and shelves) and gene bodies. Highly significant differences in DNA methylation were observed between males and females at a number of autosomal sites, with a small number of regions showing sex-specific DNA methylation trajectories across brain development. Weighted gene comethylation network analysis (WGCNA) revealed discrete modules of comethylated loci associated with fetal age that are significantly enriched for genes involved in neurodevelopmental processes. This is, to our knowledge, the most extensive study of DNA methylation across human fetal brain development to date, confirming the prenatal period as a time of considerable epigenomic plasticity.MRCUniversity of Exeter Medical SchoolWellcome Trus
Quality assurance of independent work of undergraduates: technological approach
The article reveals an effective way to stimulate learning motivation and activation of cognitive independence of the future masters of teacher educationВ статье раскрывается эффективный способ стимулирования учебной мотивации и активизации познавательной самостоятельности будущих магистров педагогического образовани
Clinical Presentation of Ocular Surface Squamous Neoplasia in Kenya.
IMPORTANCE: There is a trend toward treating conjunctival lesions suspected to be ocular surface squamous neoplasia (OSSN) based on the clinical impression. OBJECTIVE: To describe the presentation of OSSN and identify clinical features that distinguish it from benign lesions and subsequently evaluate their recognizability. DESIGN, SETTING, AND PARTICIPANTS: Prospective multicenter study in Kenya from July 2012 through July 2014 of 496 adults presenting with conjunctival lesions. One histopathologist examined all specimens. Six additional masked ophthalmologists independently examined photographs from 100 participants and assessed clinical features. EXPOSURES: Comprehensive history, slitlamp examination, and photography before excision biopsy. MAIN OUTCOMES AND MEASURES: Frequency of clinical features in OSSN and benign lesions were recorded. Proportions and means were compared using χ2, Fisher exact test, or t test as appropriate. Interobserver agreement was estimated using the κ statistic. Examiners' assessments were compared with a reference. RESULTS: Among 496 participants, OSSN was the most common (38%) histological diagnosis, followed by pterygium (36%) and actinic keratosis (19%). Patients with OSSN were slightly older (mean [SD] age, 41 [11.6] vs 38 [10.9] years; P = .002) and tended to have lower levels of education than patients with benign lesions (P = .001). Females predominated (67% of OSSN vs 64% of benign lesions; P = .65). Human immunodeficiency virus infection was common among patients with OSSN (74%). The most common location was the nasal limbus (61% OSSN vs 78% benign lesions; P < .001). Signs more frequent in OSSN included feeder vessels (odds ratio [OR], 5.8 [95% CI, 3.2-10.5]), moderate inflammation (OR, 3.5 [95% CI, 1.8-6.8]), corneal involvement (OR, 2.7 [95% CI, 1.8-4.0]), leukoplakia (OR, 2.6 [95% CI, 1.7-3.9]), papilliform surface (OR, 2.1 [95% CI, 1.3-3.5]), pigmentation (OR, 1.5 [95% CI, 1.0-2.2]), temporal location (OR, 2.0 [95% CI, 1.2-3.2]), circumlimbal location (6.7% vs 0.3%; P < .001), severe inflammation (6.7% vs 0.3%; P < .001), and larger mean (SD) diameter (6.8 [3.2] vs 4.8 [2.8] mm; P < .001). All OSSN signs were also observed in benign lesions. There was slight to fair interobserver agreement in assessment of most signs and diagnosis (κ, 0.1-0.4). The positive predictive value of clinical appearance in identifying OSSN was 54% (interquartile range, 51%-56%) from photographs in which prevalence was 32%. CONCLUSIONS AND RELEVANCE: With overlapping phenotypes and modest interobserver agreement, OSSN and benign conjunctival lesions are not reliably distinguished clinically. Point-of-care diagnostic tools may help
Role of public and private funding in the rising caesarean section rate:a cohort study
Objective: The caesarean section rates have been rising in the developed world for over two decades. This study assessed the involvement of the public and private health sectors in this increase. Design: Population-based, retrospective cohort study. Setting: Public and private hospitals in Western Australia. Participants: Included in this study were 155 646 births to nulliparous women during 1996-2008. Main outcome measures: Caesarean section rates were calculated separately for four patient type groups defined according to mothers' funding source at the time of birth (public/private) and type of delivery hospital ( public/private). The average annual per cent change (AAPC) for the caesarean section rates was calculated using joinpoint regression. Results: Overall, there were 45 903 caesarean sections performed (29%) during the study period, 24 803 in-labour and 21 100 prelabour. Until 2005, the rate of caesarean deliveries increased most rapidly on average annually for private patients delivering in private hospitals (AAPC=6.5%) compared with public patients in public hospitals (AAPC=4.3%, p<0.0001). This increase could mostly be attributed to an increase in prelabour caesarean deliveries for this group of women and could not be explained by an increase in breech deliveries, placenta praevia or multiple pregnancies. Conclusions: Our results indicate that an increase in the prelabour caesarean delivery rate for private patients in private hospitals has been driving the increase in the caesarean section rate for nulliparous women since 1996. Future research with more detailed information on indication for the prelabour caesarean section is needed to understand the reasons for these findings
Toluidine Blue 0.05% Vital Staining for the Diagnosis of Ocular Surface Squamous Neoplasia in Kenya.
IMPORTANCE: Clinical features are unreliable for distinguishing ocular surface squamous neoplasia (OSSN) from benign conjunctival lesions. OBJECTIVE: To evaluate the adverse effects, accuracy, and interobserver variation of toluidine blue 0.05% vital staining in distinguishing OSSN, confirmed by histopathology, from other conjunctival lesions. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study in Kenya from July 2012 through July 2014 of 419 adults with suspicious conjunctival lesions. Pregnant and breastfeeding women were excluded. EXPOSURES: Comprehensive ophthalmic slitlamp examination was conducted. Vital staining with toluidine blue 0.05% aqueous solution was performed before surgery. Initial safety testing was conducted on large tumors scheduled for exenteration looking for corneal toxicity on histology before testing smaller tumors. We asked about pain or discomfort after staining and evaluated the cornea at the slitlamp for epithelial defects. Lesions were photographed before and after staining. MAIN OUTCOMES AND MEASURES: Diagnosis was confirmed by histopathology. Six examiners assessed photographs from a subset of 100 consecutive participants for staining and made a diagnosis of OSSN vs non-OSSN. Staining was compared with histopathology to estimate sensitivity, specificity, and predictive values. Adverse effects were enumerated. Interobserver agreement was estimated using the κ statistic. RESULTS: A total of 143 of 419 participants (34%) had OSSN by histopathology. The median age of all participants was 37 years (interquartile range, 32-45 years) and 278 (66%) were female. A total of 322 of the 419 participants had positive staining while 2 of 419 were equivocal. There was no histological evidence of corneal toxicity. Mild discomfort was reported by 88 (21%) and mild superficial punctate keratopathy seen in 7 (1.7%). For detecting OSSN, toluidine blue had a sensitivity of 92% (95% CI, 87%-96%), specificity of 31% (95% CI, 25%-36%), positive predictive value of 41% (95% CI, 35%-46%), and negative predictive value of 88% (95% CI, 80%-94%). Interobserver agreement was substantial for staining (κ = 0.76) and moderate for diagnosis (κ = 0.40). CONCLUSIONS AND RELEVANCE: With the high sensitivity and low specificity for OSSN compared with histopathology among patients with conjunctival lesions, toluidine blue 0.05% vital staining is a good screening tool. However, it is not a good diagnostic tool owing to a high frequency of false-positives. The high negative predictive value suggests that a negative staining result indicates that OSSN is relatively unlikely
Psychometric properties of the Quality of Life Inventory-Disability (QI-Disability) measure
PURPOSE: Children with intellectual disability encounter daily challenges beyond those captured in current quality of life measures. This study evaluated a new parent-report measure for children with intellectual disability, the Quality of Life Inventory-Disability (QI-Disability). METHODS: QI-Disability was administered to 253 primary caregivers of children (aged 5-18 years) with intellectual disability across four diagnostic groups: Rett syndrome, Down syndrome, cerebral palsy or autism spectrum disorder. Exploratory and confirmatory factor analyses were conducted and goodness of fit of the factor structure assessed. Associations between QI-Disability scores, and diagnostic and age groups were examined with linear regression. RESULTS: Six domains were identified: physical health, positive emotions, negative emotions, social interaction, leisure and the outdoors, and independence. Goodness-of-fit statistics were satisfactory and similar for the whole sample and when the sample was split by ability to walk or talk. On 100 point scales and compared to Rett syndrome, children with Down syndrome had higher leisure and the outdoors (coefficient 10.6, 95% CI 3.4,17.8) and independence (coefficient 29.7, 95% CI 22.9, 36.5) scores, whereas children with autism spectrum disorder had lower social interaction scores (coefficient -?12.8, 95% CI -?19.3, -?6.4). Scores for positive emotions (coefficient -?6.1, 95% CI -?10.7, -?1.6) and leisure and the outdoors (coefficient 5.4, 95% CI -?10.6, -?0.1) were lower for adolescents compared with children. CONCLUSIONS: Initial evaluation suggests that QI-Disability is a reliable and valid measure of quality of life across the spectrum of intellectual disability. It has the potential to allow clearer identification of support needs and measure responsiveness to interventions
Early mortality and primary causes of death in mothers of children with ID or ASD: a retrospective cohort study
INTRODUCTION: Mothers of children with intellectual disability or autism spectrum disorder (ASD) have poorer health than other mothers. Yet no research has explored whether this poorer health is reflected in mortality rates or whether certain causes of death are more likely. We aimed to calculate the hazard ratios for death and for the primary causes of death in mothers of children with intellectual disability or ASD compared to other mothers. METHODS: The study population comprised all mothers of live-born children in Western Australia from 1983-2005. We accessed state-wide databases which enabled us to link socio-demographic details, birth dates, diagnoses of intellectual disability or ASD in the children and dates and causes of death for all mothers who had died prior to 2011. Using Cox Regression with death by any cause and death by each of the three primary causes as the event of interest, we calculated hazard ratios for death for mothers of children intellectual disability or ASD compared to other mothers. RESULTS AND DISCUSSION: During the study period, mothers of children with intellectual disability or ASD had more than twice the risk of death. Mothers of children with intellectual disability were 40% more likely to die of cancer; 150% more likely to die of cardiovascular disease and nearly 200% more likely to die from misadventure than other mothers. Due to small numbers, only hazard ratios for cancer were calculated for mothers of children with ASD. These mothers were about 50% more likely to die from cancer than other mothers. Possible causes and implications of our results are discussed. CONCLUSION: Similar studies, pooling data from registries elsewhere, would improve our understanding of factors increasing the mortality of mothers of children with intellectual disability or ASD. This would allow the implementation of informed services and interventions to improve these mothers' longevity
Homogenization via formal multiscale asymptotics and volume averaging: How do the two techniques compare?
A wide variety of techniques have been developed to homogenize transport equations in multiscale and multiphase systems. This has yielded a rich and diverse field, but has also resulted in the emergence of isolated scientific communities and disconnected bodies of literature. Here, our goal is to bridge the gap between formal multiscale asymptotics and the volume averaging theory. We illustrate the methodologies via a simple example application describing a parabolic transport problem and, in so doing, compare their respective advantages/disadvantages from a practical point of view. This paper is also intended as a pedagogical guide and may be viewed as a tutorial for graduate students as we provide historical context, detail subtle points with great care, and reference many fundamental works
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