122 research outputs found
Recognition of Face Identity and Emotion in Expressive Specific Language Impairment
Objective: To study face and emotion recognition in children with mostly expressive specific language impairment (SLI-E). Subjects and Methods: A test movie to study perception and recognition of faces and mimic-gestural expression was applied to 24 children diagnosed as suffering from SLI-E and an age-matched control group of normally developing children. Results: Compared to a normal control group, the SLI-E children scored significantly worse in both the face and expression recognition tasks with a preponderant effect on emotion recognition. The performance of the SLI-E group could not be explained by reduced attention during the test session. Conclusion: We conclude that SLI-E is associated with a deficiency in decoding non-verbal emotional facial and gestural information, which might lead to profound and persistent problems in social interaction and development. Copyright (C) 2012 S. Karger AG, Base
Mycobacterium tuberculosis Glucosyl-3-Phosphoglycerate Synthase: Structure of a Key Enzyme in Methylglucose Lipopolysaccharide Biosynthesis
Tuberculosis constitutes today a serious threat to human health worldwide, aggravated by the increasing number of identified multi-resistant strains of Mycobacterium tuberculosis, its causative agent, as well as by the lack of development of novel mycobactericidal compounds for the last few decades. The increased resilience of this pathogen is due, to a great extent, to its complex, polysaccharide-rich, and unusually impermeable cell wall. The synthesis of this essential structure is still poorly understood despite the fact that enzymes involved in glycosidic bond synthesis represent more than 1% of all M. tuberculosis ORFs identified to date. One of them is GpgS, a retaining glycosyltransferase (GT) with low sequence homology to any other GTs of known structure, which has been identified in two species of mycobacteria and shown to be essential for the survival of M. tuberculosis. To further understand the biochemical properties of M. tuberculosis GpgS, we determined the three-dimensional structure of the apo enzyme, as well as of its ternary complex with UDP and 3-phosphoglycerate, by X-ray crystallography, to a resolution of 2.5 and 2.7 Å, respectively. GpgS, the first enzyme from the newly established GT-81 family to be structurally characterized, displays a dimeric architecture with an overall fold similar to that of other GT-A-type glycosyltransferases. These three-dimensional structures provide a molecular explanation for the enzyme's preference for UDP-containing donor substrates, as well as for its glucose versus mannose discrimination, and uncover the structural determinants for acceptor substrate selectivity. Glycosyltransferases constitute a growing family of enzymes for which structural and mechanistic data urges. The three-dimensional structures of M. tuberculosis GpgS now determined provide such data for a novel enzyme family, clearly establishing the molecular determinants for substrate recognition and catalysis, while providing an experimental scaffold for the structure-based rational design of specific inhibitors, which lay the foundation for the development of novel anti-tuberculosis therapies
Arabidopsis AtVPS15 is essential for pollen development and germination through modulating phosphatidylinositol 3-phosphate formation
Arabidopsis thaliana phosphatidylinositol 3-kinase (AtVPS34) functions in the development and germination of pollen by catalyzing the biosynthesis of phosphatidylinositol 3-phosphate (PI3P). In yeast, Vps15p is required for the membrane targeting and activity of Vps34. The expression of Arabidopsis thaliana VPS15 (AtVPS15), an ortholog of yeast Vps15, is mainly detected in pollen grains and pollen tubes. To determine its role in pollen development and pollen tube growth, we attempted to isolate the T-DNA insertion mutants of AtVPS15; however, homozygous lines of atvps15 were not obtained from the progeny of atvps15/+ heterozygotes. Genetic analysis revealed that the abnormal segregation is due to the failure of transmission of the atvps15 allele through pollen. Most pollen grains from the atvps15/+ genotype are viable, with normal exine structure and nuclei, but some mature pollen grains are characterized with unusual large vacuoles that are not observed in pollen grains from the wild AtVPS15 genotype. The germination ratio of pollen from the atvps15/+ genotype is about half when compared to that from the wild AtVPS15 genotype. When supplied with PI3P, in vitro pollen germination of the atvps15/+ genotype is greatly improved. Presumably, AtVPS15 functions in pollen development and germination by regulating PI3P biosynthesis in Arabidopsis
Effect of Tobacco Smoking on The Clinical, Histopathological, and Serological Manifestations of Sjögren’s Syndrome
The authors wish to thank Dr. A. Darise Farris for her critical review of the cellular immune response discussion.Objectives To assess the association of smoking habits with the clinical, serological, and histopathological manifestations of Sjögren’s syndrome (SS) and non-Sjögren’s sicca (non-SS sicca). Methods Cross-sectional case-control study of 1288 patients with sicca symptoms (587 SS and 701 non-SS sicca) evaluated in a multi-disciplinary research clinic. Smoking patterns were obtained from questionnaire data and disease-related clinical and laboratory data were compared between current, past, ever, and never smokers. Results Current smoking rates were 4.6% for SS patients compared to 14.1% in non-SS sicca (p = 5.17x10E-09), 18% in a local lupus cohort (p = 1.13x10E-14) and 16.8% in the community (p = 4.12x10E-15). Current smoking was protective against SS classification (OR 0.35, 95%CI 0.22–0.56, FDR q = 1.9E10-05), focal lymphocytic sialadenitis (OR 0.26, 95%CI 0.15–0.44, FDR q = 1.52x10E-06), focus score ≥1 (OR 0.22, 95%CI 0.13–0.39, FDR q = 1.43x10E-07), and anti-Ro/SSA(+) (OR 0.36, 95%CI 0.2–0.64, FDR q = 0.0009); ever smoking was protective against the same features and against anti-La/SSB(+) (OR 0.52, 95%CI 0.39–0.70, FDR q = 5.82x10E-05). Duration of smoking was inversely correlated with SS even after controlling for socioeconomic status, BMI, alcohol and caffeine consumption. Conclusions Current tobacco smoking is negatively and independently associated with SS, protecting against disease-associated humoral and cellular autoimmunity. The overall smoking rate amongst SS patients is significantly lower than in matched populations and the effects of smoking are proportional to exposure duration. In spite of the protective effects of tobacco on SS manifestations, it is associated with other serious comorbidities such as lung disease, cardiovascular risk and malignancy, and should thus be strongly discouraged in patients with sicca.Yeshttp://www.plosone.org/static/editorial#pee
The impact of biologics and tofacitinib on cardiovascular risk factors and outcomes in patients with rheumatic disease: a systematic literature review
Introduction Rheumatic diseases are autoimmune, inflammatory diseases often associated with cardiovascular (CV) disease, a major cause of mortality in these patients. In recent years, treatment with biologic and targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs), either as monotherapy or in combination with other drugs, have become the standard of treatment. In this systematic literature review, we evaluated the effect of treatment with biologic or tofacitinib on the CV risk and outcomes in these patients. Methods A systematic search was performed in MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for articles reporting on CV risk and events in patients with rheumatic disease treated with a biologic agent or tofacitinib. Articles identified were subjected to two levels of screening. Articles that passed the first level based on title and abstract were assessed on full-text evaluation. The quality of randomized clinical trials was assessed by Jadad scoring system and the quality of the other studies and abstracts was assessed using the Downs and Black instrument. The data extracted included study design, baseline patient characteristics, and measurements of CV risk and events. Results Of the 5722 articles identified in the initial search, screening yielded 105 unique publications from 90 unique studies (33 clinical trials, 39 prospective cohort studies, and an additional 18 retrospective studies) that reported CV risk outcomes. A risk of bias analysis for each type of report indicated that they were of good or excellent quality. Importantly, despite some limitations in data reported, there were no indications of significant increase in adverse CV events or risk in response to treatment with the agents evaluated. Conclusions Treatment with biologic or tofacitinib appears to be well-tolerated with respect to CV outcomes in these patients
The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist
Yeast vacuoles fragment in an asymmetrical two-phase process with distinct protein requirements.
Yeast vacuoles fragment and fuse in response to environmental conditions, such as changes in osmotic conditions or nutrient availability. Here we analyze osmotically induced vacuole fragmentation by time-lapse microscopy. Small fragmentation products originate directly from the large central vacuole. This happens by asymmetrical scission rather than by consecutive equal divisions. Fragmentation occurs in two distinct phases. Initially, vacuoles shrink and generate deep invaginations that leave behind tubular structures in their vicinity. Already this invagination requires the dynamin-like GTPase Vps1p and the vacuolar proton gradient. Invaginations are stabilized by phosphatidylinositol 3-phosphate (PI(3)P) produced by the phosphoinositide 3-kinase complex II. Subsequently, vesicles pinch off from the tips of the tubular structures in a polarized manner, directly generating fragmentation products of the final size. This phase depends on the production of phosphatidylinositol-3,5-bisphosphate and the Fab1 complex. It is accelerated by the PI(3)P- and phosphatidylinositol 3,5-bisphosphate-binding protein Atg18p. Thus vacuoles fragment in two steps with distinct protein and lipid requirements
Is there a higher genetic load of susceptibility loci in familial ankylosing spondylitis?
Several genetic risk variants for ankylosing spondylitis (AS) have been identified in genome-wide association studies. Our objective was to examine whether familial AS cases have a higher genetic load of these susceptibility variants.Overall, 502 AS patients were examined, consisting of 312 patients who had first-degree relatives (FDRs) with AS (familial) and 190 patients who had no FDRs with AS or spondylarthritis (sporadic). All patients and affected FDRs fulfilled the modified New York criteria for AS. The patients were recruited from 2 US cohorts (the North American Spondylitis Consortium and the Prospective Study of Outcomes in Ankylosing Spondylitis) and from the UK-Oxford cohort. The frequencies of AS susceptibility loci in IL-23R, IL1R2, ANTXR2, ERAP-1, 2 intergenic regions on chromosomes 2p15 and 21q22, and HLA-B27 status as determined by the tag single-nucleotide polymorphism (SNP) rs4349859 were compared between familial and sporadic cases of AS. Association between SNPs and multiplex status was assessed by logistic regression controlling for sibship size.HLA-B27 was significantly more prevalent in familial than sporadic cases of AS (odds ratio 4.44 [95% confidence interval 2.06, 9.55], P = 0.0001). Furthermore, the AS risk allele at chromosome 21q22 intergenic region showed a trend toward higher frequency in the multiplex cases (P = 0.08). The frequency of the other AS risk variants did not differ significantly between familial and sporadic cases, either individually or combined.HLA-B27 is more prevalent in familial than sporadic cases of AS, demonstrating higher familial aggregation of AS in patients with HLA-B27 positivity. The frequency of the recently described non-major histocompatibility complex susceptibility loci is not markedly different between the sporadic and familial cases of AS
Oskar-induced endocytic activation and actin remodeling for anchorage of the Drosophila germ plasm
In many animals, germ-cell fate is specified by inheritance of the germ plasm, which is enriched in maternal RNAs and proteins. Assembly of the Drosophila germ (pole) plasm begins with the localization and translation of oskar (osk) RNA at the oocyte posterior pole. osk RNA produces two isoforms, long and short Osk. Short Osk recruits other pole plasm components, and long Osk restricts them to the oocyte cortex. Although molecular functions of long Osk remain mysterious, it is known to be involved in endocytic activation and actin cytoskeletal remodeling. We identified several vesicular trafficking machinery components that act downstream of long Osk in pole plasm assembly. These included the Rab5 effector protein Rabenosyn-5 (Rbsn-5) and the Golgi/endosomal protein Mon2, both of which were crucial for Osk-induced actin remodeling and the anchoring of pole plasm components. We propose that, in response to long Osk, the Rab5/Rbsn-5-dependent endocytic pathway promotes the formation of specialized vesicles, and Mon2 acts on these vesicles as a scaffold to instruct actin nucleators like Cappuccino and Spire to remodel the actin cytoskeleton, which anchors pole plasm components to the cortex. This mechanism may be applicable to the asymmetric localization of macromolecular structures such as protein-RNA complexes in other systems
- …
