57 research outputs found
Functional analysis of the Helicobacter pullorum N-linked protein glycosylation system.
N-linked protein glycosylation systems operate in species from all three domains of life. The model bacterial N-linked glycosylation system from Campylobacter jejuni is encoded by pgl genes present at a single chromosomal locus. This gene cluster includes the pglB oligosaccharyltransferase responsible for transfer of glycan from lipid carrier to protein. Although all genomes from species of the Campylobacter genus contain a pgl locus, among the related Helicobacter genus only three evolutionarily related species (H. pullorum, H. canadensis and H. winghamensis) potentially encode N-linked protein glycosylation systems. Helicobacter putative pgl genes are scattered in five chromosomal loci and include two putative oligosaccharyltransferase-encoding pglB genes per genome. We have previously demonstrated the in vitro N-linked glycosylation activity of H. pullorum resulting in transfer of a pentasaccharide to a peptide at asparagine within the sequon (D/E)XNXS/T. In this study, we identified the first H. pullorum N-linked glycoprotein, termed HgpA. Production of histidine-tagged HgpA in the background of insertional knockout mutants of H. pullorum pgl/wbp genes followed by analysis of HgpA glycan structures demonstrated the role of individual gene products in the PglB1-dependent N-linked protein glycosylation pathway. Glycopeptide purification by zwitterionic-hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry identified six glycosites from five H. pullorum proteins, which was consistent with proteins reactive with a polyclonal antiserum generated against glycosylated HgpA. This study demonstrates functioning of a H. pullorum N-linked general protein glycosylation system
Examination of Type IV Pilus Expression and Pilus-Associated Phenotypes in Kingella kingae Clinical Isolates▿
Kingella kingae is a gram-negative bacterium that is being recognized increasingly as a cause of septic arthritis and osteomyelitis in young children. Previous work established that K. kingae expresses type IV pili that mediate adherence to respiratory epithelial and synovial cells. PilA1 is the major pilus subunit in K. kingae type IV pili and is essential for pilus assembly. To develop a better understanding of the role of K. kingae type IV pili during colonization and invasive disease, we examined a collection of clinical isolates for pilus expression and in vitro adherence. In addition, in a subset of isolates we performed nucleotide sequencing to assess the level of conservation of PilA1. The majority of respiratory and nonendocarditis blood isolates were piliated, while the majority of joint fluid, bone, and endocarditis blood isolates were nonpiliated. The piliated isolates formed either spreading/corroding or nonspreading/noncorroding colonies and were uniformly adherent, while the nonpiliated isolates formed domed colonies and were nonadherent. PilA1 sequence varied significantly from strain to strain, resulting in substantial variability in antibody reactivity. These results suggest that type IV pili may confer a selective advantage on K. kingae early in infection and a selective disadvantage on K. kingae at later stages in the pathogenic process. We speculate that PilA1 is immunogenic during natural infection and undergoes antigenic variation to escape the immune response
Diseño de una cartilla y un video de orientación conceptual a docentes sin formación disciplinar en el área de artes plásticas para los grados segundo a quinto de educación básica primaria
El presente proyecto de investigación pretende aportar a los docentes sin formación en artes una cartilla y un video de orientación conceptual que oriente a docentes sin formación en Artes Plásticas, elementos, conceptos y propuestas que 15 beneficien el desarrollo de actividades propias para los cursos de Segundo a Quinto de Primaria. En algunas Instituciones Educativas Públicas y Privadas, se han encontrado dificultades en el Área, debido a que los Docentes que asumen esta asignatura, no tienen la formación disciplinar en Educación Artística, es así, como el grupo de docentes en formación decide realizar una diagnostico con respecto a la Didáctica de las Artes Plásticas que practican los docentes no idóneos, para ayudar a cualificar sus procesos educativos en artes. Se encuentra que algunos Docentes a cargo del Área desconocen las tendencias artísticas, conceptos y técnicas que ayuden al estudiante a relacionarse con el arte y a desarrollar en los educandos todas aquellas habilidades motrices y conceptuales que permiten las Artes Plásticas
Diseño de una cartilla y un video de orientación conceptual a docentes sin formación disciplinar en el área de artes plásticas para los grados segundo a quinto de educación básica primaria
El presente proyecto de investigación pretende aportar a los docentes sin formación en artes una cartilla y un video de orientación conceptual que oriente a docentes sin formación en Artes Plásticas, elementos, conceptos y propuestas que 15 beneficien el desarrollo de actividades propias para los cursos de Segundo a Quinto de Primaria. En algunas Instituciones Educativas Públicas y Privadas, se han encontrado dificultades en el Área, debido a que los Docentes que asumen esta asignatura, no tienen la formación disciplinar en Educación Artística, es así, como el grupo de docentes en formación decide realizar una diagnostico con respecto a la Didáctica de las Artes Plásticas que practican los docentes no idóneos, para ayudar a cualificar sus procesos educativos en artes. Se encuentra que algunos Docentes a cargo del Área desconocen las tendencias artísticas, conceptos y técnicas que ayuden al estudiante a relacionarse con el arte y a desarrollar en los educandos todas aquellas habilidades motrices y conceptuales que permiten las Artes Plásticas
Analysis of Sleep Macrostructure in Patients Diagnosed with Parkinson’s Disease
Patients diagnosed with Parkinson’s disease present sleep disorders with a higher frequency than the general population. The sleep architecture in these patients shows variations with respect to the normal population, so in this work it was decided to investigate the characteristics of the macroarchitecture of sleep in patients diagnosed with Parkinson’s disease. A polysomnographic study was carried out on 77 patients diagnosed with Parkinson’s disease. All the studies were processed according to the AASM Manual for the Scoring of Sleep and Associated Events v.2.2, and to the criteria of the International Classification of Sleep Disorders 3rd ed. (2014). Processing was carried out using descriptive statistics, as well as non-parametric analysis for comparison between cases and controls. The group of patients showed significant reductions of the N2, N3, and REM sleep stages when compared with a control group, as well as a significant increase in intra-sleep wakefulness. The number of REM–NoREM sleep cycles and sleep efficiency showed marked reduction compared to the control group. There was a statistically significant difference in the macroarchitecture of sleep between patients diagnosed with Parkinson’s disease and healthy controls
Case-Only Survival Analysis Reveals Unique Effects of Genotype, Sex, and Coronary Disease Severity on Survivorship
<div><p>Survival bias may unduly impact genetic association with complex diseases; gene-specific survival effects may further complicate such investigations. Coronary artery disease (CAD) is a complex phenotype for which little is understood about gene-specific survival effects; yet, such information can offer insight into refining genetic associations, improving replications, and can provide candidate genes for both mortality risk and improved survivorship in CAD. Building on our previous work, the purpose of this current study was to: evaluate <i>LSAMP</i> SNP-specific hazards for all-cause mortality post-catheterization in a larger cohort of our CAD cases; and, perform additional replication in an independent dataset. We examined two <i>LSAMP</i> SNPs—rs1462845 and rs6788787—using CAD case-only Cox proportional hazards regression for additive genetic effects, censored on time-to-all-cause mortality or last follow-up among Caucasian subjects from the Catheterization Genetics Study (CATHGEN; <i>n</i> = 2,224) and the Intermountain Heart Collaborative Study (IMHC; <i>n</i> = 3,008). Only after controlling for age, sex, body mass index, histories of smoking, type 2 diabetes, hyperlipidemia and hypertension (<i>HR</i> = 1.11, 95%<i>CI</i> = 1.01–1.22, <i>p</i> = 0.032), rs1462845 conferred significantly increased hazards of all-cause mortality among CAD cases. Even after controlling for multiple covariates, but in only the primary cohort, rs6788787 conferred significantly improved survival (<i>HR</i> = 0.80, 95% <i>CI</i> = 0.69–0.92, <i>p</i> = 0.002). Post-hoc analyses further stratifying by sex and disease severity revealed replicated effects for rs1462845: even after adjusting for aforementioned covariates and coronary interventional procedures, males with severe burden of CAD had significantly amplified hazards of death with the minor variant of rs1462845 in both cohorts (<i>HR</i> = 1.29, <i>95% CI</i> = 1.08–1.55, <i>p</i> = 0.00456; replication <i>HR</i> = 1.25, <i>95% CI</i> = 1.05–1.49, <i>p</i> = 0.013). Kaplan-Meier curves revealed unique cohort-specific genotype effects on survival. Additional analyses demonstrated that the homozygous risk genotype (‘A/A’) fully explained the increased hazard in both cohorts. None of the post-hoc analyses in control subjects were significant for any model. This suggests that genetic effects of rs1462845 on survival are unique to CAD presence. This represents formal, replicated evidence of genetic contribution of rs1462845 to increased risk for all-cause mortality; the contribution is unique to CAD case status and specific to males with severe burden of CAD.</p></div
Genetic Variants in the Bone Morphogenic Protein Gene Family Modify the Association between Residential Exposure to Traffic and Peripheral Arterial Disease.
There is a growing literature indicating that genetic variants modify many of the associations between environmental exposures and clinical outcomes, potentially by increasing susceptibility to these exposures. However, genome-scale investigations of these interactions have been rarely performed particularly in the case of air pollution exposures. We performed race-stratified genome-wide gene-environment interaction association studies on European-American (EA, N = 1623) and African-American (AA, N = 554) cohorts to investigate the joint influence of common single nucleotide polymorphisms (SNPs) and residential exposure to traffic ("traffic exposure")-a recognized vascular disease risk factor-on peripheral arterial disease (PAD). Traffic exposure was estimated via the distance from the primary residence to the nearest major roadway, defined as the nearest limited access highways or major arterial. The rs755249-traffic exposure interaction was associated with PAD at a genome-wide significant level (P = 2.29x10-8) in European-Americans. Rs755249 is located in the 3' untranslated region of BMP8A, a member of the bone morphogenic protein (BMP) gene family. Further investigation revealed several variants in BMP genes associated with PAD via an interaction with traffic exposure in both the EA and AA cohorts; this included interactions with non-synonymous variants in BMP2, which is regulated by air pollution exposure. The BMP family of genes is linked to vascular growth and calcification and is a novel gene family for the study of PAD pathophysiology. Further investigation of BMP8A using the Genotype Tissue Expression Database revealed multiple variants with nominally significant (P < 0.05) interaction P-values in our EA cohort were significant BMP8A eQTLs in tissue types highlight relevant for PAD such as rs755249 (tibial nerve, eQTL P = 3.6x10-6) and rs1180341 (tibial artery, eQTL P = 5.3x10-6). Together these results reveal a novel gene, and possibly gene family, associated with PAD via an interaction with traffic air pollution exposure. These results also highlight the potential for interactions studies, particularly at the genome scale, to reveal novel biology linking environmental exposures to clinical outcomes
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