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Extensive Heterogeneity (extensive + heterogeneity)
Selected AbstractsLipopolysaccharides of anaerobic beer spoilage bacteria of the genus Pectinatus, lipopolysaccharides of a Gram-positive genusFEMS MICROBIOLOGY REVIEWS, Issue 5 2004Ilkka M. Helander Abstract Bacteria of the genus Pectinatus emerged during the seventies as contaminants and spoilage organisms in packaged beer. This genus comprises two species, Pectinatus cerevisiiphilus and Pectinatus frisingensis; both are strict anaerobes. On the basis of genomic properties the genus is placed among low GC Gram-positive bacteria (phylum Firmicutes, class Clostridia, order Clostridiales, family Acidaminococcaceae). Despite this assignment, Pectinatus bacteria possess an outer membrane and lipopolysaccharide (LPS) typical of Gram-negative bacteria. The present review compiles the structural and compositional studies performed on Pectinatus LPS. These lipopolysaccharides exhibit extensive heterogeneity, i.e. several macromolecularly and structurally distinct LPS molecules are produced by each strain. Whereas heterogeneity is a common property in lipopolysaccharides, Pectinatus LPS have been shown to contain exceptional carbohydrate structures, consisting of a fairly conserved core region that carries a large non-repetitive saccharide that probably replaces the O-specific chain. Such structures represent a novel architectural principle of the LPS molecule. [source] Genomic convergence to identify candidate genes for Alzheimer Disease on chromosome 10HUMAN MUTATION, Issue 3 2009Xueying Liang Abstract A broad region of chromosome 10 (chr10) has engendered continued interest in the etiology of late-onset Alzheimer Disease (LOAD) from both linkage and candidate gene studies. However, there is a very extensive heterogeneity on chr10. We converged linkage analysis and gene expression data using the concept of genomic convergence that suggests that genes showing positive results across multiple different data types are more likely to be involved in AD. We identified and examined 28 genes on chr10 for association with AD in a Caucasian case-control dataset of 506 cases and 558 controls with substantial clinical information. The cases were all LOAD (minimum age at onset ,60 years). Both single marker and haplotypic associations were tested in the overall dataset and 8 subsets defined by age, gender, ApoE and clinical status. PTPLA showed allelic, genotypic and haplotypic association in the overall dataset. SORCS1 was significant in the overall data sets (p=0.0025) and most significant in the female subset (allelic association p=0.00002, a 3-locus haplotype had p=0.0005). Odds Ratio of SORCS1 in the female subset was 1.7 (p<0.0001). SORCS1 is an interesting candidate gene involved in the A, pathway. Therefore, genetic variations in PTPLA and SORCS1 may be associated and have modest effect to the risk of AD by affecting A, pathway. The replication of the effect of these genes in different study populations and search for susceptible variants and functional studies of these genes are necessary to get a better understanding of the roles of the genes in Alzheimer disease. 30, 463,471, 2009. © 2008 Wiley-Liss, Inc. [source] Complex patterns of mitochondrial dynamics in human pancreatic cells revealed by fluorescent confocal imagingJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1-2 2010Andrey V. Kuznetsov Abstract Mitochondrial morphology and intracellular organization are tightly controlled by the processes of mitochondrial fission,fusion. Moreover, mitochondrial movement and redistribution provide a local ATP supply at cellular sites of particular demands. Here we analysed mitochondrial dynamics in isolated primary human pancreatic cells. Using real time confocal microscopy and mitochondria-specific fluorescent probes tetramethylrhodamine methyl ester and MitoTracker Green we documented complex and novel patterns of spatial and temporal organization of mitochondria, mitochondrial morphology and motility. The most commonly observed types of mitochondrial dynamics were (i) fast fission and fusion; (ii) small oscillating movements of the mitochondrial network; (iii) larger movements, including filament extension, retraction, fast (0.1,0.3 ,m/sec.) and frequent oscillating (back and forth) branching in the mitochondrial network; (iv) as well as combinations of these actions and (v) long-distance intracellular translocation of single spherical mitochondria or separated mitochondrial filaments with velocity up to 0.5 ,m/sec. Moreover, we show here for the first time, a formation of unusual mitochondrial shapes like rings, loops, and astonishingly even knots created from one or more mitochondrial filaments. These data demonstrate the presence of extensive heterogeneity in mitochondrial morphology and dynamics in living cells under primary culture conditions. In summary, this study reports new patterns of morphological changes and dynamic motion of mitochondria in human pancreatic cells, suggesting an important role of integrations of mitochondria with other intracellular structures and systems. [source] Characterization of sialylated and fucosylated glycopeptides of ,2-glycoprotein I by a combination of HILIC LC and MALDI MS/MSJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6-7 2010Akira Kondo Abstract Characterization of low microgram levels of glycoprotein remains a challenge due to extensive heterogeneity of the conjugated N -glycans at each individual glycosylation site. We present an optimized, sensitive workflow for glycopeptide isolation and characterization that exploits the complementary features of RP (Poros R2) and hydrophilic (zwitter-ionic hydrophilic interaction chromatography) chromatographic resins. The glycopeptide analysis workflow was applied to human ,2-glycoprotein I (,2-GPI, apolipoprotein H), which contains multiple N -glycosylation sites. Conditions for rapid proteolytic digestion of ,2-GPI using low-specificity proteases were optimized to detect ,2-GPI glycopeptides by MS. We demonstrate the importance of ensuring sufficient column capacity of both hydrophobic and hydrophilic stationary phases for optimal glycoprofiling by MS. The enriched glycopeptides were characterized using MALDI quadrupole TOF MS/MS. A total of 23 glycan structures, including sialylated bi- and tri-antennary complex type glycans, were characterized at three N -glycosylation sites, namely Asn-143, Asn-174 and Asn-234, of ,2-GPI. Further exploration of the complementary nature of RP and HILIC stationary phases for glycopeptide isolation prior to MS analysis may eventually enable systematic analysis of complex glycoprotein samples in functional proteomic research and advance our understanding of the biological role of protein glycosylation. [source] Dental fear in adults: a meta-analysis of behavioral interventionsCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 4 2004Gerd Kvale Abstract , Objectives:, The aim of this meta-analytic and systematic quantitative approach is to examine the effects of behavioral interventions for dental anxiety and dental phobia. Methods:, Eighty studies were identified where dental fear treatment with behavioral methods was evaluated. Thirty-eight of 80 met entry criteria and were included in a meta-analysis. Results:, The calculated effect sizes (ESs) for self-reported anxiety after intervention indicate positive changes in 36 of the 38 studies and no changes in two. The overall ES = 1.8 (95% CI: 1.6, 1.8). The percent of subjects with post-treatment dental visits in the first 6 months post-treatment varied between 50 and 100%. The overall ES for attendance at dental visits, weighted by sample size, is 1.4 (95% CI: 1.3, 1.6). The homogeneity analysis indicates that the studies cannot be adequately described in one ES. The reported percentage of subjects with a dental visit between 6 months and 4 years post-treatment varied from 48 to 100%. The overall weighted ES for visiting the dentist, adjusted for drop-outs in the studies, is 1.2 (95% CI: 0.99, 1.4). Conclusions:, Despite extensive heterogeneity, changes in self-reported anxiety represent medium to large ESs. Patients signing up for a behavioral intervention for dental fear can be expected to report a significant reduction in their fear, and this effect generally seems to be lasting. Mean long-term attendance (>4 years after treatment) is 77%. [source] | |||||||||||||