612 research outputs found
Coexpression of Spectrally Distinct Rhodopsins in Aedes aegypti R7 Photoreceptors
The retina of the mosquito Aedes aegypti can be divided into four regions based on the non-overlapping expression of a UV sensitive Aaop8 rhodopsin and a long wavelength sensitive Aaop2 type rhodopsin in the R7 photoreceptors. We show here that another rhodopsin, Aaop9, is expressed in all R7 photoreceptors and a subset of R8 photoreceptors. In the dorsal region, Aaop9 is expressed in both the cell body and rhabdomere of R7 and R8 cells. In other retinal regions Aaop9 is expressed only in R7 cells, being localized to the R7 rhabdomere in the central and ventral regions and in both the cell body and rhabdomere within the ventral stripe. Within the dorsal-central transition area ommatidia do not show a strict pairing of R7–R8 cell types. Thus, Aaop9 is coexpressed in the two classes of R7 photoreceptors previously distinguished by the non-overlapping expression of Aaop8 and Aaop2 rhodopsins. Electroretinogram analysis of transgenic Drosophila shows that Aaop9 is a short wavelength rhodopsin with an optimal response to 400–450 nm light. The coexpressed Aaop2 rhodopsin has dual wavelength sensitivity of 500–550 nm and near 350 nm in the UV region. As predicted by the spectral properties of each rhodopsin, Drosophila photoreceptors expressing both Aaop9 and Aaop2 rhodopsins exhibit a uniform sensitivity across the broad 350–550 nm light range. We propose that rhodopsin coexpression is an adaptation within the R7 cells to improve visual function in the low-light environments in which Ae. aegypti is active
A meta-analysis of pharmacotherapy for social anxiety disorder: an examination of efficacy, moderators, and mediators
INTRODUCTION: Social anxiety disorder (SAD) is among the most prevalent mental disorders, associated with impaired functioning and poor quality of life. Pharmacotherapy is the most widely utilized treatment option. The current study provides an updated meta-analytic review of the efficacy of pharmacotherapy and examines moderators and mediators of treatment efficacy. Areas Covered: A comprehensive search of the current literature yielded 52 randomized, pill placebo-controlled trials of pharmacotherapy for adults diagnosed with SAD. Data on potential mediators of treatment outcome were collected, as well as data necessary to calculate pooled correlation matrices to compute indirect effects. Expert Opinion: The overall effect size of pharmacotherapy for SAD is small to medium (Hedges' g = 0.41). Effect sizes were not moderated by age, sex, length of treatment, initial severity, risk of study bias, or publication year. Furthermore, reductions in symptoms mediated pharmacotherapy's effect on quality of life. Support was found for reverse mediation. Future directions may include sustained efforts to examine treatment mechanisms of pharmacotherapy using rigorous longitudinal methodology to better establish temporal precedence
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Association of persistent and severe postnatal depression with child outcomes
IMPORTANCE Maternal postnatal depression (PND) is common and associated with adverse child outcomes. These effects are not inevitable, and it is critical to identify those most at risk. Previous work suggests that the risks of adverse outcomes are increased when PND is severe
and persistent, but this has not been systematically studied.
OBJECTIVE To examine the association between differing levels of persistence and severity of PND and long-term child outcomes.
DESIGN, SETTING, AND PARTICIPANTS The sample for this observational study comprised participants in the Avon Longitudinal Study of Parents and Children in the United Kingdom. Three thresholds of PND severity—moderate, marked, and severe—were defined using the self-rated Edinburgh Postnatal Depression Scale (EPDS). Depression was defined as persistent when the EPDS score was above the threshold level at both 2 and 8 months after
childbirth. For each of these severity and persistence categories, the following were examined: (1) the trajectories of later EPDS scores (6 time points between 21 months and 11 years after childbirth) and (2) child outcomes—behavioral problems at 3.5 years of age,
school-leaving mathematics grades at 16 years of age, and depression at 18 years of age. Data analysis was conducted from July 12, 2016, to February 8, 2017.
MAIN OUTCOMES AND MEASURES Child behavioral problems at 3.5 years of age using the Rutter total problems scale, school-leaving mathematics grades at 16 years of age extracted from records of external national public examinations, and offspring depression at 18 years of
age using the Clinical Interview Schedule–Revised.
RESULTS For the 9848 mothers in the sample, the mean (SD) age at delivery was 28.5 (4.7) years. Of the 8287 children, 4227 (51%) were boys and 4060 (49%) were girls. Compared with women with PND that was not persistent and women who did not score above the EPDS threshold, for all 3 severity levels, women with persistent PND showed elevated depressive symptoms up to 11 years after childbirth. Whether persistent or not, PND doubled the risk of child behavior disturbance. The odds ratio (OR) for child behavioral disturbance for mothers
with moderate PND was 2.22 (95% CI, 1.74-2.83), for mothers with marked PND was 1.91 (95% CI, 1.36-2.68), and for mothers with severe PND was 2.39 (95% CI, 1.78-3.22).
Persistence of severe PND was particularly important to child development, substantially increasing the risk for behavioral problems at 3.5 years of age (OR, 4.84; 95% CI, 2.94-7.98), lower mathematics grades at 16 years of age (OR, 2.65; 95% CI, 1.26-5.57), and higher prevalence of depression at 18 years of age (OR, 7.44; 95% CI, 2.89-19.11).
CONCLUSIONS AND RELEVANCE Persistent and severe PND substantially raises the risk for adverse outcome on all child measures. Meeting criteria for depression both early and late in the postnatal year, especially when the mood disturbance is severe, should alert health care
professionals to a depression that is likely to be persistent and to be associated with an especially elevated risk of multiple adverse child outcomes. Treatment for this group should be prioritized
Isothermal DNA amplification using the T4 replisome: circular nicking endonuclease-dependent amplification and primase-based whole-genome amplification.
In vitro reconstitution of the bacteriophage T4 replication machinery provides a novel system for fast and processive isothermal DNA amplification. We have characterized this system in two formats: (i) in circular nicking endonuclease-dependent amplification (cNDA), the T4 replisome is supplemented with a nicking endonuclease (Nb.BbvCI) and a reverse primer to generate a well-defined uniform double-stranded linear product and to achieve up to 1100-fold linear amplification of a plasmid in 1 h. (ii) The T4 replisome with its primase (gp61) can also support priming and exponential amplification of genomic DNA in primase-based whole-genome amplification (T4 pWGA). Low amplification biases between 4.8 and 9.8 among eight loci for 0.3-10 ng template DNA suggest that this method is indeed suitable for uniform whole-genome amplification. Finally, the utility of the T4 replisome for isothermal DNA amplification is demonstrated in various applications, including incorporation of functional tags for DNA labeling and immobilization; template generation for in vitro transcription/translation and sequencing; and colony screening and DNA quantification
Helicobacter pylori Lipopolysaccharide Is Synthesized via a Novel Pathway with an Evolutionary Connection to Protein N-Glycosylation
Lipopolysaccharide (LPS) is a major component on the surface of Gram negative bacteria and is composed of lipid A-core and the O antigen polysaccharide. O polysaccharides of the gastric pathogen Helicobacter pylori contain Lewis antigens, mimicking glycan structures produced by human cells. The interaction of Lewis antigens with human dendritic cells induces a modulation of the immune response, contributing to the H. pylori virulence. The amount and position of Lewis antigens in the LPS varies among H. pylori isolates, indicating an adaptation to the host. In contrast to most bacteria, the genes for H. pylori O antigen biosynthesis are spread throughout the chromosome, which likely contributed to the fact that the LPS assembly pathway remained uncharacterized. In this study, two enzymes typically involved in LPS biosynthesis were found encoded in the H. pylori genome; the initiating glycosyltransferase WecA, and the O antigen ligase WaaL. Fluorescence microscopy and analysis of LPS from H. pylori mutants revealed that WecA and WaaL are involved in LPS production. Activity of WecA was additionally demonstrated with complementation experiments in Escherichia coli. WaaL ligase activity was shown in vitro. Analysis of the H. pylori genome failed to detect a flippase typically involved in O antigen synthesis. Instead, we identified a homolog of a flippase involved in protein N-glycosylation in other bacteria, although this pathway is not present in H. pylori. This flippase named Wzk was essential for O antigen display in H. pylori and was able to transport various glycans in E. coli. Whereas the O antigen mutants showed normal swimming motility and injection of the toxin CagA into host cells, the uptake of DNA seemed to be affected. We conclude that H. pylori uses a novel LPS biosynthetic pathway, evolutionarily connected to bacterial protein N-glycosylation
Are fetal growth impairment and preterm birth causally related to child attention problems and ADHD?:Evidence from a comparison between high-income and middle-income cohorts
Cross-cohort comparison is an established method for improving causal inference. This study compared 2 cohorts, 1 from a high-income country and another from a middle-income country, to (1) establish whether birth exposures may play a causal role in the development of childhood attention problems; and (2) identify whether confounding structures play a different role in parent-reported attention difficulties compared with attention deficit hyperactivity disorder (ADHD) diagnoses.Birth exposures included low birth weight (LBW), small-for-gestational age (SGA), small head circumference (HC) and preterm birth (PTB)). Outcomes of interest were attention difficulties (Strengths and Difficulties Questionnaire, SDQ) and ADHD (Development and Well-Being Assessment, DAWBA). Associations between exposures and outcomes were compared between 7-year-old children from the Avon Longitudinal Study of Parents and Children (ALSPAC) in the UK (N=6849) and the 2004 Pelotas cohort in Brazil (N=3509).For attention difficulties (SDQ), the pattern of association with birth exposures was similar between cohorts: following adjustment, attention difficulties were associated with SGA (OR=1.59, 95% CI 1.20 to 2.19) and small HC (OR=1.64, 95% CI 1.11 to 2.41) in ALSPAC and SGA (OR=1.35, 95% CI 1.04 to 1.75) in Pelotas. For ADHD, however, the pattern of association following adjustment differed markedly between cohorts. In ALSPAC, ADHD was associated with LBW (OR=2.29, 95% CI 1.09 to 4.80) and PTB (OR=2.33, 95% CI 1.23 to 4.42). In the Pelotas cohort, however, ADHD was associated with SGA (OR=1.69, 95% CI 1.02 to 2.82).The findings suggest that fetal growth impairment may play a causal role in the development of attention difficulties in childhood, as similar associations were identified across both cohorts. Confounding structures, however, appear to play a greater role in determining whether a child meets the full diagnostic criteria for ADHD
Genome-wide screening for DNA variants associated with reading and language traits
This research was funded by: Max Planck Society, the University of St Andrews - Grant Number: 018696, US National Institutes of Health - Grant Number: P50 HD027802, Wellcome Trust - Grant Number: 090532/Z/09/Z, and Medical Research Council Hub Grant Grant Number: G0900747 91070Reading and language abilities are heritable traits that are likely to share some genetic influences with each other. To identify pleiotropic genetic variants affecting these traits, we first performed a genome‐wide association scan (GWAS) meta‐analysis using three richly characterized datasets comprising individuals with histories of reading or language problems, and their siblings. GWAS was performed in a total of 1862 participants using the first principal component computed from several quantitative measures of reading‐ and language‐related abilities, both before and after adjustment for performance IQ. We identified novel suggestive associations at the SNPs rs59197085 and rs5995177 (uncorrected P ≈ 10–7 for each SNP), located respectively at the CCDC136/FLNC and RBFOX2 genes. Each of these SNPs then showed evidence for effects across multiple reading and language traits in univariate association testing against the individual traits. FLNC encodes a structural protein involved in cytoskeleton remodelling, while RBFOX2 is an important regulator of alternative splicing in neurons. The CCDC136/FLNC locus showed association with a comparable reading/language measure in an independent sample of 6434 participants from the general population, although involving distinct alleles of the associated SNP. Our datasets will form an important part of on‐going international efforts to identify genes contributing to reading and language skills.Publisher PDFPeer reviewe
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Maternal postnatal depression and anxiety and their association with child emotional negativity and behavior problems at two years
Postnatal maternal depression is associated with poorer child emotional and behavioral functioning, but it is unclear whether this occurs following brief episodes or only with persistent depression. Little research has examined the relation between postnatal anxiety and child outcomes. The present study examined the role of postnatal major depressive disorder (MDD) and generalized anxiety disorder (GAD) symptom chronicity on children’s emotional and behavioral functioning at 24 months. Following postnatal screening mothers (n = 296) were identified as having MDD, GAD, MDD and GAD, or no disorder at 3 months postnatal; the average age was 32.3 (SD = 5.0), 91.9% self-identified as Caucasian, and 62.2% were married. Maternal disorder symptom severity was assessed by questionnaires and structured interview at 3, 6, 10, 14, and 24 months postpartum. At 24 months, child emotional negativity and behavior were assessed using questionnaires and by direct observation. Latent trait-state-occasion modeling was used to represent maternal disorder symptom chronicity; both stable trait and time-specific occasion portions of maternal symptomatology were examined in relation to child outcomes. Only the stable trait portion of maternal MDD and GAD symptom severity were related to maternal report of child behavior problems and higher levels of emotional negativity. Persistent maternal MDD, but not GAD, symptom severity was related to higher levels of child emotional negativity as measured observationally. These data suggest that children’s behavior problems and emotional negativity are adversely affected by persistent maternal depression, and possibly anxiety. This has implications for interventions to prevent negative effects of postnatal psychopathology on children
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