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Sample records for augments n-glycolyl sialic

  1. Metabolism of Vertebrate Amino Sugars with N-Glycolyl Groups

    Science.gov (United States)

    Bergfeld, Anne K.; Pearce, Oliver M. T.; Diaz, Sandra L.; Pham, Tho; Varki, Ajit

    2012-01-01

    The two major mammalian sialic acids are N-acetylneuraminic acid and N-glycolylneuraminic acid (Neu5Gc). The only known biosynthetic pathway generating Neu5Gc is the conversion of CMP-N-acetylneuraminic acid into CMP-Neu5Gc, which is catalyzed by the CMP-Neu5Ac hydroxylase enzyme. Given the irreversible nature of this reaction, there must be pathways for elimination or degradation of Neu5Gc, which would allow animal cells to adjust Neu5Gc levels to their needs. Although humans are incapable of synthesizing Neu5Gc due to an inactivated CMAH gene, exogenous Neu5Gc from dietary sources can be metabolically incorporated into tissues in the face of an anti-Neu5Gc antibody response. However, the metabolic turnover of Neu5Gc, which apparently prevents human cells from continued accumulation of this immunoreactive sialic acid, has not yet been elucidated. In this study, we show that pre-loaded Neu5Gc is eliminated from human cells over time, and we propose a conceivable Neu5Gc-degrading pathway based on the well studied metabolism of N-acetylhexosamines. We demonstrate that murine tissue cytosolic extracts harbor the enzymatic machinery to sequentially convert Neu5Gc into N-glycolylmannosamine, N-glycolylglucosamine, and N-glycolylglucosamine 6-phosphate, whereupon irreversible de-N-glycolylation of the latter results in the ubiquitous metabolites glycolate and glucosamine 6-phosphate. We substantiate this finding by demonstrating activity of recombinant human enzymes in vitro and by studying the fate of radiolabeled pathway intermediates in cultured human cells, suggesting that this pathway likely occurs in vivo. Finally, we demonstrate that the proposed degradative pathway is partially reversible, showing that N-glycolylmannosamine and N-glycolylglucosamine (but not glycolate) can serve as precursors for biosynthesis of endogenous Neu5Gc. PMID:22692205

  2. Detection of N-Glycolyl GM3 Ganglioside in Neuroectodermal Tumors by Immunohistochemistry: An Attractive Vaccine Target for Aggressive Pediatric Cancer

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    Alejandra M. Scursoni

    2011-01-01

    Full Text Available The N-glycolylated ganglioside NeuGc-GM3 has been described in solid tumors such as breast carcinoma, nonsmall cell lung cancer, and melanoma, but is usually not detected in normal human cells. Our aim was to evaluate the presence of NeuGc-GM3 in pediatric neuroectodermal tumors by immunohistochemistry. Twenty-seven archival cases of neuroblastoma and Ewing sarcoma family of tumors (ESFT were analyzed. Formalin-fixed, paraffin-embedded tumor samples were cut into 5 μm sections. The monoclonal antibody 14F7, a mouse IgG1 that specifically recognizes NeuGc-GM3, and a peroxidase-labeled polymer conjugated to secondary antibodies were used. Presence of NeuGc-GM3 was evident in 23 of 27 cases (85%, with an average of about 70% of positive tumors cells. Immunoreactivity was moderate to intense in most tumors, showing a diffuse cytoplasmic and membranous staining, although cases of ESFT demonstrated a fine granular cytoplasmic pattern. No significant differences were observed between neuroblastoma with and without NMYC oncogene amplification, suggesting that expression of NeuGc-GM3 is preserved in more aggressive cancers. Until now, the expression of N-glycolylated gangliosides in pediatric neuroectodermal tumors has not been investigated. The present study evidenced the expression of NeuGc-GM3 in a high proportion of neuroectodermal tumors, suggesting its potential utility as a specific target of immunotherapy.

  3. Tissue micro array analysis of ganglioside N-glycolyl GM3 expression and signal transducer and activator of transcription (STAT-3 activation in relation to dendritic cell infiltration and microvessel density in non-small cell lung cancer

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    de Gruijl Tanja D

    2009-06-01

    Full Text Available Abstract Background Tumor immune escape and angiogenesis contribute to tumor progression, and gangliosides and activation of signal transducer and activator of transcription (STAT-3 are implicated in these processes. As both are considered as novel therapeutic targets, we assessed the possible association of ganglioside GM3 expression and STAT3 activation with suppression of dendritic cell (DC activation and angiogenesis in non-small cell lung cancer (NSCLC. Methods Immunohistochemistry was performed on a tissue array to determine N-glycolyl GM3 (GM3 and phosphorylated STAT3 (pSTAT3 expression in 176 primary NSCLC resections. Median values of GM3 and pSTAT3 expression were used as cut off. Microvessel density (MVD was determined by CD34 staining and morphology. CD1a and CD83 were used to determine infiltrating immature and mature dendritic cells, respectively. Results 94% and 71% of the NSCLC samples expressed GM3 and nuclear pSTAT3, respectively. Median overall survival was 40.0 months. Both low GM3 expression and high pSTAT3 expression were associated with a worse survival, which reached near significance for GM3 (P = 0.08. Microvessel density (MVD, determined by CD34 staining and morphology, was lower in NSCLC samples with high GM3 expression. CD1a+ cells (immature DCs were more frequent in NSCLC tissues as compared to peritumoral lung tissue, while CD83+ cells (mature DCs were more frequent in peritumoral lung tissue. CD83+ DCs were less frequent in NSCLC tissues with high GM3 expression. Conclusion GM3 and pSTAT3 are widely expressed in NSCLC. Based on CD83 expression, GM3, but not pSTAT3, appeared to be involved in tumor-induced DC suppression. pSTAT3 expression was not associated with MVD, while GM3 might play an anti-angiogenic role.

  4. Sialic Acid Receptors of Viruses.

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    Matrosovich, Mikhail; Herrler, Georg; Klenk, Hans Dieter

    2015-01-01

    Sialic acid linked to glycoproteins and gangliosides is used by many viruses as a receptor for cell entry. These viruses include important human and animal pathogens, such as influenza, parainfluenza, mumps, corona, noro, rota, and DNA tumor viruses. Attachment to sialic acid is mediated by receptor binding proteins that are constituents of viral envelopes or exposed at the surface of non-enveloped viruses. Some of these viruses are also equipped with a neuraminidase or a sialyl-O-acetyl-esterase. These receptor-destroying enzymes promote virus release from infected cells and neutralize sialic acid-containing soluble proteins interfering with cell surface binding of the virus. Variations in the receptor specificity are important determinants for host range, tissue tropism, pathogenicity, and transmissibility of these viruses.

  5. IMPORTANCE AND CLINICAL SIGNIFICANCE OF SERUM SIALIC ...

    African Journals Online (AJOL)

    Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. IMPORTANCE AND CLINICAL SIGNIFICANCE OF SERUM SIALIC ACID AND LACTATE DEHYDROGENASE DETERMINATION IN CERVICAL CANCER PATIENTS. Farouk H. Saber, Essam F. Hammouda, Mohamed Khaled M, Essam A. Afifi. Abstract.

  6. Quantification of free sialic acid in urine by HPLC-electrospray tandem mass spectrometry: A tool for the diagnosis of sialic acid storage disease

    NARCIS (Netherlands)

    Valianpour, Fredoen; Abeling, Nicolaas G. G. M.; Duran, Marinus; Huijmans, Jan G. M.; Kulik, Willem

    2004-01-01

    Background: Sialic acid storage diseases (SSDs) are severe autosomal recessive neurodegenerative disorders caused by a transport defect across the lysosomal membrane, which leads to accumulation of sialic acid in tissues, fibroblasts, and urine. Defective free sialic acid transport can be

  7. Characterisation of CMP-sialic acid transporter substrate recognition

    NARCIS (Netherlands)

    Maggioni, A.; Itzstein, M. von; Guzman, I.B. Rodriguez; Ashikov, A.M.; Stephens, A.S.; Haselhorst, T.; Tiralongo, J.

    2013-01-01

    CMP-sialic acid transporter: We report an in-depth, multidisciplinary, structural study that has identified the amino acid residues intimately involved in CMP-sialic acid transporter (CST) substrate specificity. Our data provide a significant contribution towards a better understanding the

  8. Determination of Sialic Acids by Acidic Ninhydrin Reaction

    OpenAIRE

    Yao,Kenzabroh; Ubuka,Toshihiko

    1987-01-01

    A new acidic ninhydrin method for determining free sialic acids is described. The method is based on the reaction of sialic acids with Gaitonde's acid ninhydrin reagent 2 which yields a stable color with an absorption maximum at 470 nm. The standard curve is linear in the range of 5 to 500 nmol of N-acetylneuraminic acid per 0.9 ml of reaction mixture. The reaction was specific only for sialic acids among the various sugars and sugar derivatives examined. Some interference of this method by c...

  9. Automated solid-phase synthesis of oligosaccharides containing sialic acids

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    Chian-Hui Lai

    2015-05-01

    Full Text Available A sialic acid glycosyl phosphate building block was designed and synthesized. This building block was used to prepare α-sialylated oligosaccharides by automated solid-phase synthesis selectively.

  10. Characterisation of CMP-sialic acid transporter substrate recognition.

    Science.gov (United States)

    Maggioni, Andrea; von Itzstein, Mark; Rodríguez Guzmán, Ingrid Bibiana; Ashikov, Angel; Stephens, Alexandre S; Haselhorst, Thomas; Tiralongo, Joe

    2013-10-11

    CMP-sialic acid transporter: We report an in-depth, multidisciplinary, structural study that has identified the amino acid residues intimately involved in CMP-sialic acid transporter (CST) substrate specificity. Our data provide a significant contribution towards a better understanding the structure-function relationship of this important family of transporters and the rational design of CST inhibitors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Biochemical engineering of cell surface sialic acids stimulates axonal growth.

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    Büttner, Bettina; Kannicht, Christoph; Schmidt, Carolin; Löster, Klemens; Reutter, Werner; Lee, Hye-Youn; Nöhring, Sabine; Horstkorte, Rüdiger

    2002-10-15

    Sialylation is essential for development and regeneration in mammals. Using N-propanoylmannosamine, a novel precursor of sialic acid, we were able to incorporate unnatural sialic acids with a prolonged N-acyl side chain (e.g., N-propanoylneuraminic acid) into cell surface glycoconjugates. Here we report that this biochemical engineering of sialic acid leads to a stimulation of neuronal cells. Both PC12 cells and cerebellar neurons showed a significant increase in neurite outgrowth after treatment with this novel sialic acid precursor. Furthermore, also the reestablishment of the perforant pathway was stimulated in brain slices. In addition, we surprisingly identified several cytosolic proteins with regulatory functions, which are differentially expressed after treatment with N-propanoylmannosamine. Because sialic acid is the only monosaccharide that is activated in the nucleus, we hypothesize that transcription could be modulated by the unnatural CMP-N-propanoylneuraminic acid and that sialic acid activation might be a general tool to regulate cellular functions, such as neurite outgrowth.

  12. Advances in the Biology and Chemistry of Sialic Acids

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    Chen, Xi; Varki, Ajit

    2010-01-01

    Sialic acids are a subset of nonulosonic acids, which are nine-carbon alpha-keto aldonic acids. Natural existing sialic acid-containing structures are presented in different sialic acid forms, various sialyl linkages, and on diverse underlying glycans. They play important roles in biological, pathological, and immunological processes. Sialobiology has been a challenging and yet attractive research area. Recent advances in chemical and chemoenzymatic synthesis as well as large-scale E. coli cell-based production have provided a large library of sialoside standards and derivatives in amounts sufficient for structure-activity relationship studies. Sialoglycan microarrays provide an efficient platform for quick identification of preferred ligands for sialic acid-binding proteins. Future research on sialic acid will continue to be at the interface of chemistry and biology. Research efforts will not only lead to a better understanding of the biological and pathological importance of sialic acids and their diversity, but could also lead to the development of therapeutics. PMID:20020717

  13. Evaluation of serum concentration of sialic acid in foals affected by Rhodococcosis

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    ali hassanpour

    2015-11-01

    Full Text Available This study was conducted for evaluation of sialic acid concentration in serum of 19 foals with Rhodococcosis and compared with 18 normal foals in horse stables in Tabriz area in Iran. Sick foals were detected using clinical and laboratory (culture of nasal discharge findings. Blood samples were collected from jugular vein in all foals and serum was separated. Sialic acid (serum total sialic acid, lipid-bound sialic acid and protein-bound sialic acid concentrations in the serum were measured in all samples. Increasing of total sialic acid, lipid-bound sialic acid and protein-bound sialic acid in the sick group was significant (p=0.000, p=0.012 and p=0.001, respectively. In the normal group, the correlation between serumic parameters was not significant. In the sick group, the correlation between total sialic acid and protein-bound sialic acid was not significant (r=0.095 but there was a significant correlation between total sialic acid and lipid-bound sialic acid (r=0.842. The correlation between lipid-bound and protein-bound sialic acid was also insignificant (r=0.196. The results obtained revealed that Rhodococcosis increases the serumic concentration of sialic acid and there is a correlation between increases in serumic concentration of various parameters.

  14. Discoveries of the structures of sialic acid and CMP-sialic acid (1957-1960): a letter from Saul Roseman.

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    Schnaar, Ronald L; Lee, Yuan C

    2017-06-01

    Sialic acids have a special place in vertebrate glycobiology, where they constitute the dominant terminal saccharides on many cell surface glycans. From early studies that identified sialoglycans as receptors for important pathogens and toxins to more recent discoveries of sialic acid-binding proteins essential for immune system (and other) functions in humans, sialic acids and sialoglycans have become cornerstones in understanding vertebrate glycobiology and pathology. During a remarkable 3-year period in the late 1950s, a newly minted postdoctoral fellow (Donald G. Comb) and his young mentor (Saul Roseman) made a surprising series of discoveries that put sialic acid research on sound chemical and biochemical footing. A detailed personal letter written by Dr. Roseman that describes this period of intense sialic acid discovery, complete with inserted figures, was given to one of us (Y.C.L.) several years later. The text and figures of this letter provide a look back at the enthusiasm, rigor and serendipity that led to their important findings through the eyes of one of the key figures in sialic acid research. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. The participation of sialic acids in microglia-neuron interactions.

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    Wielgat, Przemyslaw; Braszko, Jan J

    2012-01-01

    Since it is known that sialic acid participates in neuronal plasticity, it is resonable to investigate its role in microglia-neuron interactions. In this study, we tested the effects of enzymatic removal of sialic acid on neurite and cell body density in microglia-neuron co-cultures. Additionaly, we analyzed the expression of Siglec-F protein, putative receptor for sialic acids, in microglial cells as well as its affinity to neurons. The results showed that removal of sialic acids affects neuronal integrity and changes microglial morphology. In presence of microglial cells, endoneuraminidase and α-neuraminidase significantly reduced neurite density (p0.05) decreased the number of neuronal cell bodies in comparison to control co-cultures. Neuraminidases-treated neurons showed reduced binding of Siglec-F protein, which we found in microglial cells. Our results suggest that interactions between sialic acids and Siglec receptors may protect neuronal integrity during neurodegenerative processes. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. A CMP-sialic acid transporter cloned from Arabidopsis thaliana.

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    Bakker, Hans; Routier, Françoise; Ashikov, Angel; Neumann, Detlef; Bosch, Dirk; Gerardy-Schahn, Rita

    2008-08-11

    Sialylation of glycans is ubiquitous in vertebrates, but was believed to be absent in plants, arthropods, and fungi. However, recently evidence has been provided for the presence of sialic acid in these evolutionary clades. In addition, homologs of mammalian genes involved in sialylation can be found in the genomes of these taxa and for some Drosophila enzymes, involvement in sialic acid metabolism has been documented. In plant genomes, homologs of sialyltransferase genes have been identified, but there activity could not be confirmed. Several mammalian cell lines exist with defects in the sialylation pathway. One of these is the Chinese hamster ovary cell line Lec2, deficient in CMP-sialic acid transport to the Golgi lumen. These mutants provide the possibility to clone genes by functional complementation. Using expression cloning, we have identified an Arabidopsis thaliana nucleotide sugar transporter that is able to complement the CMP-sialic acid transport deficiency of Lec2 cells. The isolated gene (At5g41760) is a member of the triose-phosphate/nucleotide sugar transporter gene family. Recombinant expression of the gene in yeast and testing in vitro confirmed its ability to transport CMP-sialic acid.

  17. Expanding the diversity of unnatural cell surface sialic acids

    Energy Technology Data Exchange (ETDEWEB)

    Luchansky, Sarah J.; Goon, Scarlett; Bertozzi, Carolyn R.

    2003-10-30

    Novel chemical reactivity can be introduced onto cell surfaces through metabolic oligosaccharide engineering. This technique exploits the substrate promiscuity of cellular biosynthetic enzymes to deliver unnatural monosaccharides bearing bioorthogonal functional groups into cellular glycans. For example, derivatives of N-acetylmannosamine (ManNAc) are converted by the cellular biosynthetic machinery into the corresponding sialic acids and subsequently delivered to the cell surface in the form of sialoglycoconjugates. Analogs of N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) are also metabolized and incorporated into cell surface glycans, likely through the sialic acid and GalNAc salvage pathways, respectively. Furthermore, GlcNAc analogs can be incorporated into nucleocytoplasmic proteins in place of {beta}-O-GlcNAc residues. These pathways have been exploited to integrate unique electrophiles such as ketones and azides into the target glycoconjugate class. These functional groups can be further elaborated in a chemoselective fashion by condensation with hydrazides and by Staudinger ligation, respectively, thereby introducing detectable probes onto the cell. In conclusion, sialic acid derivatives are efficient vehicles for delivery of bulky functional groups to cell surfaces and masking of their hydroxyl groups improves their cellular uptake and utilization. Furthermore, the successful introduction of photoactivatable aryl azides into cell surface glycans opens up new avenues for studying sialic acid-binding proteins and elucidating the role of sialic acid in essential processes such as signaling and cell adhesion.

  18. Quantification of free and total sialic acid excretion by LC-MS/MS

    NARCIS (Netherlands)

    van der Ham, Maria; Prinsen, Berthil H C M T; Huijmans, Jan G M; Abeling, Nicolaas G G M; Dorland, Bert; Berger, Ruud; de Koning, Tom J; de Sain-van der Velden, Monique G M

    2007-01-01

    BACKGROUND: The main purpose for measuring urinary free sialic acid (FSA) is to diagnose sialic acid (SA) storage diseases. Elevated amounts of conjugated sialic acid (CSA) are observed in several diseases indicating the need to quantify CSA as well. A LC-MS/MS method for quantification of FSA and

  19. Membrane sialic acid influences basophil histamine release by interfering with calcium dependence

    DEFF Research Database (Denmark)

    Jensen, C; Norn, S; Skov, P S

    1987-01-01

    The influence of the cell membrane content of sialic acid on basophil histamine release was examined in vitro in allergic patients and normal controls. Enzymatical removal of sialic acid enhanced histamine release induced by allergen and anti-IgE, whereas an increase in membrane sialic acid content....... This difference, together with the previous finding that alterations in membrane sialic acid content is reflected in the cell sensitivity to extracellular calcium, suggest an interaction between membrane sialic acid and the calcium channels involved in basophil histamine release....

  20. Titanium dioxide enrichment of sialic acid-containing glycopeptides

    DEFF Research Database (Denmark)

    Palmisano, Giuseppe; Lendal, Sara E; Larsen, Martin Røssel

    2011-01-01

    the glycosylation site of N-linked sialylated glycoproteins. The method relies on the specificity of titanium dioxide affinity chromatography to isolate sialic acid-containing glycopeptides. After enzymatic release of the glycans, the enriched sialylated glycopeptides are analyzed by mass spectrometry...

  1. AUGMENTED REALITY

    DEFF Research Database (Denmark)

    Skov, Kirsten; Bahn, Anne Louise

    2017-01-01

    Projektets grundlæggende idé er udvikling af visuel, æstetisk læring med Augmented Reality, hvor intentionen er at bidrage med konkrete undersøgelser og udforskning af begrebet Augmented Reality – herunder koblingen mellem det analoge og digitale i forhold til læring, multimodalitet og it...

  2. Augmented Reality

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter Bech; Rahn, Annette

    2015-01-01

    This chapter describes the use of iPad-facilitated application of augmented reality in the teaching of highly complex anatomical and physiological subjects in the training of nurses at undergraduate level. The general aim of the project is to investigate the potentials of this application in terms...... of augmented reality are discussed....

  3. Socket augmentation

    OpenAIRE

    Shalu Chandna; Kimpreet Kaur; Navkiran Kaur; Anish Manocha

    2015-01-01

    Introduction of dental implants have come to the forefront of modern odontology. A successful osseointegration demands an ideal quantity and quality of alveolar bone. Socket augmentation techniques are effective in minimizing postextraction alveolar ridge resorption. The aim of this paper is to review the available literature on socket augmentation with special focus on its relation with implant.

  4. Socket augmentation

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    Shalu Chandna

    2015-01-01

    Full Text Available Introduction of dental implants have come to the forefront of modern odontology. A successful osseointegration demands an ideal quantity and quality of alveolar bone. Socket augmentation techniques are effective in minimizing postextraction alveolar ridge resorption. The aim of this paper is to review the available literature on socket augmentation with special focus on its relation with implant.

  5. Insights into the evolution of sialic acid catabolism among bacteria

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    Almagro-Moreno Salvador

    2009-05-01

    Full Text Available Abstract Background Sialic acids comprise a family of nine-carbon amino sugars that are prevalent in mucus rich environments. Sialic acids from the human host are used by a number of pathogens as an energy source. Here we explore the evolution of the genes involved in the catabolism of sialic acid. Results The cluster of genes encoding the enzymes N-acetylneuraminate lyase (NanA, epimerase (NanE, and kinase (NanK, necessary for the catabolism of sialic acid (the Nan cluster, are confined 46 bacterial species, 42 of which colonize mammals, 33 as pathogens and 9 as gut commensals. We found a putative sialic acid transporter associated with the Nan cluster in most species. We reconstructed the phylogenetic history of the NanA, NanE, and NanK proteins from the 46 species and compared them to the species tree based on 16S rRNA. Within the NanA phylogeny, Gram-negative and Gram-positive bacteria do not form distinct clades. NanA from Yersinia and Vibrio species was most closely related to the NanA clade from eukaryotes. To examine this further, we reconstructed the phylogeny of all NanA homologues in the databases. In this analysis of 83 NanA sequences, Bacteroidetes, a human commensal group formed a distinct clade with Verrucomicrobia, and branched with the Eukaryotes and the Yersinia/Vibrio clades. We speculate that pathogens such as V. cholerae may have acquired NanA from a commensal aiding their colonization of the human gut. Both the NanE and NanK phylogenies more closely represented the species tree but numerous incidences of incongruence are noted. We confirmed the predicted function of the sialic acid catabolism cluster in members the major intestinal pathogens Salmonella enterica, Vibrio cholerae, V. vulnificus, Yersinia enterocolitica and Y. pestis. Conclusion The Nan cluster among bacteria is confined to human pathogens and commensals conferring them the ability to utilize a ubiquitous carbon source in mucus rich surfaces of the human body

  6. Increased expression of sialic acid in cervical biopsies with squamous intraepithelial lesions

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    Vallejo-Ruiz Verónica

    2010-11-01

    Full Text Available Abstract Background Altered sialylation has been observed during oncogenic transformation. Sialylated oligosaccharides of glycoproteins and glycolipids have been implicated in tumor progression and metastases. In the cervical cancer high levels of sialic acid have been reported in the patients serum, and an increased of total sialic acid concentration has been reported for the cervical neoplasia and cervical cancer. This study investigates the changes in expression and distribution of α2,3-linked sialic acid and α2,6- linked sialic acid in low and high squamous intraepithelial lesions and in normal tissue. Methods Lectin histochemistry was used to examine the expression and distribution of sialic acid in different grades of cervical neoplasia. We applied Maackia amurensis lectin, which interacts with α2,3-linked sialic acid and Sambucus nigra lectin specific for α2,6-linked sialic acid. Results The histochemical analysis showed that α2,3-linked sialic acid and α2,6- linked sialic acid increased in intensity and distribution in concordance with the grade of squamous intraepithelial lesion (SIL. These results are in concordance with a previous study that reports increased RNAm levels of three sialyltransferases. Conclusions These results show that the change in sialylation occurs before cancer development and may play an important role in cellular transformation. These findings provide the basis for more detailed studies of the possible role of cell surface glycoconjugates bearing sialic acid in the cellular cervix transformation.

  7. Sialic acid feeding aged rats rejuvenates stimulated salivation and colon enteric neuron chemotypes.

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    Sprenger, Norbert; Julita, Monique; Donnicola, Dominique; Jann, Alfred

    2009-12-01

    Old age is linked to numerous changes of body functions such as salivation, gastrointestinal motility, and permeability all linked to central and enteric nervous system decline. Thus, gut motility and barrier functions suffer. Sialic acid plays a key role in the nervous system at large and for many receptor functions specifically. Decreased sialylation in the elderly suggests an endogenous sialic acid deficit. We used a rat model of aging, to ask whether sialic acid feeding would affect (i) stimulated salivation, (ii) gut functions, and (iii) sialic acid levels and neuronal markers in brain and gut. We observed reduced levels of pilocarpine-stimulated salivation in old versus young rats and restored this function by sialic acid feeding. Brain ganglioside bound sialic acid levels were found lower in aged versus young rats, and sialic acid feeding partly restored the levels. The hypothalamic expression of cholinergic and panneuronal markers was reduced in aged rats. The expression of the nitrergic marker nNOS was increased upon sialic acid feeding in aged rats. Neither fecal output nor gut permeability was different between young and aged rats studied here, and sialic acid feeding did not alter these parameters. However, the colonic expression of specific nervous system markers nNOS and Uchl1 and the key enzyme for sialic acid synthesis GNE were differentially affected in young and aged rats by sialic acid feeding indicating that regulatory mechanisms change with age. Investigation of sialic acid supplementation as a functional nutrient in the elderly may help those who suffer from disorders of reduced salivation. Further research is needed to understand the differential effects of sialic acid feeding in young and aged rats.

  8. Augmented reality

    National Research Council Canada - National Science Library

    Patrik Pucer

    2011-01-01

    .... In such a mixed reality, real and virtual objects coexist in the same environment. The reality, where users watch and use the real environment upgraded with virtual objects is called augmented reality...

  9. Breast Augmentation

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    ... augmentation About Doctors & Departments Care at Mayo Clinic Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  10. Augmented reality

    Directory of Open Access Journals (Sweden)

    Patrik Pucer

    2011-08-01

    Full Text Available Today we can obtain in a simple and rapid way most of the information that we need. Devices, such as personal computers and mobile phones, enable access to information in different formats (written, pictorial, audio or video whenever and wherever. Daily we use and encounter information that can be seen as virtual objects or objects that are part of the virtual world of computers. Everyone, at least once, wanted to bring these virtual objects from the virtual world of computers into real environments and thus mix virtual and real worlds. In such a mixed reality, real and virtual objects coexist in the same environment. The reality, where users watch and use the real environment upgraded with virtual objects is called augmented reality. In this article we describe the main properties of augmented reality. In addition to the basic properties that define a reality as augmented reality, we present the various building elements (possible hardware and software that provide an insight into such a reality and practical applications of augmented reality. The applications are divided into three groups depending on the information and functions that augmented reality offers, such as help, guide and simulator.

  11. Second Sialic Acid Binding Site in Newcastle Disease Virus Hemagglutinin-Neuraminidase: Implications for Fusion

    OpenAIRE

    Zaitsev, Viatcheslav; von Itzstein, Mark; Groves, Darrin; Kiefel, Milton; Takimoto, Toru; Portner, Allen; Taylor, Garry

    2004-01-01

    Paramyxoviruses are the leading cause of respiratory disease in children. Several paramyxoviruses possess a surface glycoprotein, the hemagglutinin-neuraminidase (HN), that is involved in attachment to sialic acid receptors, promotion of fusion, and removal of sialic acid from infected cells and progeny virions. Previously we showed that Newcastle disease virus (NDV) HN contained a pliable sialic acid recognition site that could take two states, a binding state and a catalytic state. Here we ...

  12. Pentavalent Bismuth-Mediated Glycosylation Methods to Activate Sialic and Uronic Acids and the Incorporation of Sialic Acids Into Insulin

    Science.gov (United States)

    Kabotso, Daniel Elorm Kwame

    The negative charge at physiological pH of carboxylic acid-containing monosaccharides modulate the properties of many natural biomolecules such as oligosaccharides and glycoconjugates. Unfortunately, these altered electronic properties also make the incorporation of such acidic sugars more challenging as compared to the more commonly studied neutral sugars. Herein are reported the first demonstration of glycosylation reactions mediated by triphenylbis(1,1,1-trifluoromethanesulfonato)-bismuth with thioglycosides containing carboxylic acid substituents protected as esters. Unlike with many neutral sugar substrates, the addition of 1-propanethiol to the reactions proved critical to obtaining good yields of the desired glycosylation products using sialic acid, galacturonic acid, and glucuronic acid. The protocol was demonstrated to be amenable to automation using a liquid-handling platform. The consequences of artificially incorporating carboxylic-acid-containing sugars into proteins were tested by the design of a linker containing 1 to 4 sialic acids--a sugar found in many human proteins and brain tissues--that was attached via reductive amination of trityl thiopropylaldehyde at the phenyl alanine terminal end of the protein insulin produced through solid-phase peptide synthesis. Removal of the trityl group with neat trifluoroacetic acid furnished the thiol-free modified insulin that was ligated via a disulfide bond to the peptide scaffold bearing acetyl protected sialic acids. A 14-15% ammonium hydroxide solution was found to be effective in deprotecting the acetyl groups without degradation of the disulfide bond. In addition to maintaining the potency and bioactivity of insulin, the sialic acid-containing linker rendered insulin more resistant to aggregation due to heat and mechanical agitation compared to the unmodified protein.

  13. Effects of pyrimidine antagonists on sialic acid regeneration in HL-60 cells.

    Science.gov (United States)

    Hindenburg, A A; Taub, R N; Grant, S; Chang, G; Baker, M A

    1985-07-01

    Because alterations in cell membrane sialoglycoconjugates can affect the behavior of neoplastic cells, we investigated the effects of in vitro treatment with antimetabolites used in cancer therapy on the expression of membrane sialic acid in cultured HL-60 leukemic cells. In these studies, cells were incubated with Vibrio cholerae neuraminidase to remove surface sialic acid. Reappearance of membrane sialic acid during drug treatment was followed (a) by measuring changes in radioactive surface labeling of viable cells with sodium metaperiodate-sodium[3H]-borohydride, (b) by measuring the decline in accessible surface galactosyl receptor sites which occurred coincident with membrane sialic acid replacement, and (c) by measuring the incorporation of [3H]glucosamine into membrane-associated neuraminidase-labile sialic acid. We were especially interested in learning whether drugs that affect intracellular pools of cytidine triphosphate (CTP), an important nucleotide intermediate in sialylation reactions, could inhibit regeneration of membrane sialic acid. 3-Deazauridine, a competitive inhibitor of CTP synthetase, depleted CTP pools and curtailed surface membrane resialylation with little or no effect on synthesis of de novo sialic acid from precursor sugars. The addition of cytidine restored CTP pools and sialic acid regeneration. Acivicin, a glutamine antagonist, also depleted CTP pools and curtailed surface membrane resialylation. In addition, it retarded de novo synthesis of sialic acid. The addition of cytidine restored intracellular CTP pools and sialic acid regeneration. However, both cytidine and guanosine were required to restore sialic acid synthesis from precursor sugars. 1-beta-D-Arabinofuranosylcytosine, a competitive inhibitor of sialic acid synthetase and of sialyltransferase, inhibited both de novo sialic acid synthesis and membrane resialylation. Only the latter effect was reversed by the addition of exogenous cytidine. Hydroxyurea, an agent shown

  14. Pasteurella multocida CMP-sialic acid synthetase and mutants of Neisseria meningitidis CMP-sialic acid synthetase with improved substrate promiscuity.

    Science.gov (United States)

    Li, Yanhong; Yu, Hai; Cao, Hongzhi; Muthana, Saddam; Chen, Xi

    2012-03-01

    Cytidine 5'-monophosphate (CMP)-sialic acid synthetases (CSSs) catalyze the formation of CMP-sialic acid from CTP and sialic acid, a key step for sialyltransferase-catalyzed biosynthesis of sialic acid-containing oligosaccharides and glycoconjugates. More than 50 different sialic acid forms have been identified in nature. To facilitate the enzymatic synthesis of sialosides with diverse naturally occurring sialic acid forms and their non-natural derivatives, CMP-sialic acid synthetases with promiscuous substrate specificity are needed. Herein we report the cloning, characterization, and substrate specificity studies of a new CSS from Pasteurella multocida strain P-1059 (PmCSS) and a CSS from Haemophillus ducreyi (HdCSS). Based on protein sequence alignment and substrate specificity studies of these two CSSs and a Neisseria meningitidis CSS (NmCSS), as well as crystal structure modeling and analysis of NmCSS, NmCSS mutants (NmCSS_S81R and NmCSS_Q163A) with improved substrate promiscuity were generated. The strategy of combining substrate specificity studies of enzymes from different sources and protein crystal structure studies can be a general approach for designing enzyme mutants with improved activity and substrate promiscuity.

  15. Augmented Reality

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Radmer, Ole

    2017-01-01

    Artiklen præsenterer resultater fra pilotafprøvning i 7.-klasses fysik/kemi og biologi af to Augmented Reality (AR)-apps til naturfagsundervisning. Muligheder og udfordringer ved lærerens stilladsering af elevernes undersøgende samtale og modelleringskompetence er undersøgt med interview...

  16. Effect of fluoride on salivary immunoglobulins and sialic acid

    Directory of Open Access Journals (Sweden)

    Kadriye Görkem Ulu Güzel

    Full Text Available Summary Objective: The aim of our study was to evaluate the effect of fluoride on salivary immunoglobulin and sialic acid levels in children with dental fluorosis and healthy teeth who live in places with high fluoride concentration in drinking water. Method: Fifty-one (51 healthy children between 6 and 12 years old with no caries were randomly selected from primary schools enrolled in the dental-care program operated by the Department of Pediatric Dentistry. The children were divided into two groups: group I comprised 26 children with dental fluorosis [Thylstrup-Fejerskov Dental Fluorosis Index (TFI = 4] who lived in Isparta (2.7-2.8 ppm, and group II consisted of 25 children without dental fluorosis who were born in low-fluoride areas and had lived in Isparta for only the previous two years. Stimulated and unstimulated saliva were collected and analyzed for fluoride, salivary immunoglobulins and sialic acid levels. Results: Sialic acid level was correlated negatively with age. Levels of secretory immunoglobulin A (sIgA and secretory immunoglobulin G (sIgG were higher in children with dental fluorosis compared with those in group II, although these differences were not significant. Conclusion: Increased sIgA and sIgG levels may arrest the progression of caries in subjects with dental fluorosis. Given the risks of dental fluorosis, further studies of the effects of different fluoride levels in drinking water on salivary composition of children with mixed dentition are needed to confirm the results of our study and to provide data for comparison.

  17. The effect of CoQ 10 and vitamin E on serum total sialic acid, lipid ...

    African Journals Online (AJOL)

    This study was designed to evaluate the effect of CoQ10 and vitamin E on serum total sialic acid (TSA), lipid bound sialic acid (LSA) and some elements in rat administered doxorubicin (DXR). Cu levels were increased in the group treated with DXR + vitamin E in comparison with DXR (p<0.05) and CoQ10 groups (p ...

  18. Sialic Acid Uptake Is Necessary for Virulence of Pasteurella multocida in turkeys

    Science.gov (United States)

    Many pathogenic bacteria employ systems to incorporate sialic acid into their membranes as a means of protection against host defense mechanisms. Pasteurella multocida is an opportunistic pathogen which causes diseases of economic importance in a wide range of animal species and sialic acid uptake p...

  19. Erythrocyte Sialic Acid Content during Aging in Humans: Correlation with Markers of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Mohammad Murtaza Mehdi

    2012-01-01

    Full Text Available Sialic acids are substituted neuraminic acid derivatives which are typically found at the outermost end of glycan chains on the membrane in all cell types. The role of erythrocyte membrane sialic acids during aging has been established however the relationship between sialic acid and oxidative stress is not fully understood. The present work was undertaken to analyze the relationship between erythrocyte membrane sialic acid with its plasma level, membrane and plasma lipid hydroperoxide levels and plasma total antioxidant capacity. Results show that sialic acid content decreases significantly (P < 0.001 in RBC membrane (r = −0.901 and increases in plasma (r = 0.860 as a function of age in humans. Lipid peroxidation measured in the form of hydroperoxides increases significantly (P < 0.001 in plasma (r = 0.830 and RBC membranes (r = 0.875 with age in humans. The Trolox Equivalent Total Antioxidant Capacity (TETAC of plasma was found to be significantly decreased (P < 0.001, r = −0.844. We observe significant correlations between decrease of erythrocyte membrane sialic acid and plasma lipid hydroperoxide and TETAC. Based on the observed correlations, we hypothesize that increase in oxidative stress during aging may influence the sialic acid decomposition from membrane thereby altering the membrane configuration affecting many enzymatic and transporter activities. Considering the importance of plasma sialic acid as a diagnostic parameter, it is important to establish age-dependent reference.

  20. Liquid chromatography-tandem mass spectrometry assay for the quantification of free and total sialic acid in human cerebrospinal fluid.

    NARCIS (Netherlands)

    Ham, M. van der; Koning, T.J. de; Lefeber, D.J.; Fleer, A.; Prinsen, B.H.; Sain-van der Velden, M.G. de

    2010-01-01

    BACKGROUND: Analysis of sialic acid (SA) metabolites in cerebrospinal fluid (CSF) is important for clinical diagnosis. In the present study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS) method for free sialic acid (FSA) and total sialic acid (TSA) in human CSF was

  1. Liquid chromatography-tandem mass spectrometry assay for the quantification of free and total sialic acid in human cerebrospinal fluid

    NARCIS (Netherlands)

    van der Ham, Maria; de Koning, Tom J; Lefeber, Dirk; Fleer, André; Prinsen, Berthil H C M T; de Sain-van der Velden, Monique G M

    2010-01-01

    BACKGROUND: Analysis of sialic acid (SA) metabolites in cerebrospinal fluid (CSF) is important for clinical diagnosis. In the present study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS) method for free sialic acid (FSA) and total sialic acid (TSA) in human CSF was

  2. Substrate specificity of the sialic acid biosynthetic pathway

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Christina L.; Goon, Scarlett; Yarema, Kevin J.; Hinderlich, Stephan; Hang, Howard C.; Chai, Diana H.; Bertozzi, Carolyn R.

    2001-07-18

    Unnatural analogs of sialic acid can be delivered to mammalian cell surfaces through the metabolic transformation of unnatural N-acetylmannosamine (ManNAc) derivatives. In previous studies, mannosamine analogs bearing simple N-acyl groups up to five carbon atoms in length were recognized as substrates by the biosynthetic machinery and transformed into cell-surface sialoglycoconjugates [Keppler, O. T., et al. (2001) Glycobiology 11, 11R-18R]. Such structural alterations to cell surface glycans can be used to probe carbohydrate-dependent phenomena. This report describes our investigation into the extent of tolerance of the pathway toward additional structural alterations of the N-acyl substituent of ManNAc. A panel of analogs with ketone-containing N-acyl groups that varied in the lengthor steric bulk was chemically synthesized and tested for metabolic conversion to cell-surface glycans. We found that extension of the N-acyl chain to six, seven, or eight carbon atoms dramatically reduced utilization by the biosynthetic machinery. Likewise, branching from the linear chain reduced metabolic conversion. Quantitation of metabolic intermediates suggested that cellular metabolism is limited by the phosphorylation of the N-acylmannosamines by ManNAc 6-kinase in the first step of the pathway. This was confirmed by enzymatic assay of the partially purified enzyme with unnatural substrates. Identification of ManNAc 6-kinase as a bottleneck for unnatural sialic acid biosynthesis provides a target for expanding the metabolic promiscuity of mammalian cells.

  3. Mobile Collaborative Augmented Reality: The Augmented Stroll

    OpenAIRE

    Renevier, Philippe; Nigay, Laurence

    2001-01-01

    International audience; The paper focuses on Augmented Reality systems in which interaction with the real world is augmented by the computer, the task being performed in the real world. We first define what mobile AR systems, collaborative AR systems and finally mobile and collaborative AR systems are. We then present the augmented stroll and its software design as one example of a mobile and collaborative AR system. The augmented stroll is applied to Archaeology in the MAGIC (Mobile Augmente...

  4. Sialic acid changes in Dalton's lymphoma-bearing mice after cyclophosphamide and cisplatin treatment

    Directory of Open Access Journals (Sweden)

    Nicol B.M.

    2002-01-01

    Full Text Available Sialic acid changes in Dalton's lymphoma cells and other tissues of 10-12-week-old Swiss albino mice were investigated in relation to tumour growth in vivo and following cyclophosphamide (ip, 200 mg/kg body weight or cisplatin (ip, 8 mg/kg body weight treatment. Three to four animals of both sexes were used in each experimental group. The sialic acid level of tumour cells (0.88 µmol/g increased with tumour progression (1.44-1.59 µmol/g; P<=0.05 in mice. Sialic acid concentration in other tissues (liver, kidney, testes and brain also increased (~40, 10, 30 and 58%, respectively in the tumour-bearing hosts as compared with that in the respective tissues of normal mice. In vivo cyclophosphamide or cisplatin treatment resulted in an overall decrease of sialic acid contents in the tissues. Cyclophosphamide was more efficient in lowering tissue sialic acid than cisplatin (P<=0.01, ANOVA. It is suggested that sialic acid residues could be an important factor contributing to the manifestation of malignant properties in cancer cells in general and Dalton's lymphoma cells in particular. A significant decrease in the sialic acid content of Dalton's lymphoma cells after cisplatin or cyclophosphamide treatment may bring about specific changes in tumour cells which could be associated with tumour regression.

  5. The sialic acid component of the beta1 subunit modulates voltage-gated sodium channel function.

    Science.gov (United States)

    Johnson, Daniel; Montpetit, Marty L; Stocker, Patrick J; Bennett, Eric S

    2004-10-22

    Voltage-gated sodium channels (Nav) are responsible for initiation and propagation of nerve, skeletal muscle, and cardiac action potentials. Nav are composed of a pore-forming alpha subunit and often one to several modulating beta subunits. Previous work showed that terminal sialic acid residues attached to alpha subunits affect channel gating. Here we show that the fully sialylated beta1 subunit induces a uniform, hyperpolarizing shift in steady state and kinetic gating of the cardiac and two neuronal alpha subunit isoforms. Under conditions of reduced sialylation, the beta1-induced gating effect was eliminated. Consistent with this, mutation of beta1 N-glycosylation sites abolished all effects of beta1 on channel gating. Data also suggest an interaction between the cis effect of alpha sialic acids and the trans effect of beta1 sialic acids on channel gating. Thus, beta1 sialic acids had no effect gating on the of the heavily glycosylated skeletal muscle alpha subunit. However, when glycosylation of the skeletal muscle alpha subunit was reduced through chimeragenesis such that alpha sialic acids did not impact gating, beta1 sialic acids caused a significant hyperpolarizing shift in channel gating. Together, the data indicate that beta1 N-linked sialic acids can modulate Nav gating through an apparent saturating electrostatic mechanism. A model is proposed in which a spectrum of differentially sialylated Nav can directly modulate channel gating, thereby impacting cardiac, skeletal muscle, and neuronal excitability.

  6. Analysis of CMP-sialic acid transporter-like proteins in plants.

    Science.gov (United States)

    Takashima, Shou; Seino, Junichi; Nakano, Takeshi; Fujiyama, Kazuhito; Tsujimoto, Masafumi; Ishida, Nobuhiro; Hashimoto, Yasuhiro

    2009-12-01

    It is commonly accepted that sialic acids do not exist in plants. However, putative gene homologs of animal sialyltransferases and CMP-sialic acid transporters have been detected in the genomes of some plants. To elucidate the physiological functions of these genes, we cloned 2 cDNAs from Oryza sativa (Japanese rice), each of which encodes a CMP-sialic acid transporter-like protein designated as OsCSTLP1 and OsCSTLP2. To examine the CMP-sialic acid transporter activity of OsCSTLP1 and OsCSTLP2, we introduced their expression vectors into CMP-sialic acid transporter activity-deficient Lec2 cells. Transfection with OsCSTLP1 resulted in recovery of the deficit phenotype of Lec2 cells, but transfection with OsCSTLP2 did not. We also performed an in vitro nucleotide sugar transport assay using a yeast expression system. Among the nucleotide sugars examined, the OsCSTLP1-containing yeast microsomal membrane vesicles specifically incorporated CMP-sialic acid, indicating that OsCSTLP1 has CMP-sialic acid transporter activity. On the other hand, OsCSTLP2 did not exhibit any nucleotide sugar transporter activity. T-DNA insertion lines of Arabidopsis thaliana targeting the homologs of the OsCSTLP1 and OsCSTLP2 genes exhibited a lethal phenotype, suggesting that these proteins play important roles in plant development and may transport important nucleotide sugars such as CMP-Kdo in physiological conditions.

  7. The in situ distribution of glycoprotein-bound 4-O-Acetylated sialic acids in vertebrates.

    Science.gov (United States)

    Aamelfot, Maria; Dale, Ole Bendik; Weli, Simon Chioma; Koppang, Erling Olaf; Falk, Knut

    2014-05-01

    Sialic acids are located at the terminal branches of the cell glycocalyx and secreted glycan molecules. O-Acetylation is an important modification of the sialic acids, however very few studies have demonstrated the in situ distribution of the O-Acetylated sialic acids. Here the distribution of glycoprotein bound 4-O-Acetylated sialic acids (4-O-Ac sias) in vertebrates was determined using a novel virus histochemistry assay. The 4-O-Ac sias were found in the circulatory system, i.e. on the surface of endothelial cells and RBCs, of several vertebrate species, though most frequently in the cartilaginous fish (class Chondrichthyes) and the bony fish (class Osteichthyes). The O-Acetylated sialic acid was detected in 64 % of the examined fish species. Even though the sialic acid was found less commonly in higher vertebrates, it was found at the same location in the positive species. The general significance of this endothelial labelling pattern distribution is discussed. The seemingly conserved local position through the evolution of the vertebrates, suggests an evolutionary advantage of this sialic acid modification.

  8. Sialic acid catabolism confers a competitive advantage to pathogenic vibrio cholerae in the mouse intestine.

    Science.gov (United States)

    Almagro-Moreno, Salvador; Boyd, E Fidelma

    2009-09-01

    Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae DeltananA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment.

  9. Sialic Acid Catabolism Confers a Competitive Advantage to Pathogenic Vibrio cholerae in the Mouse Intestine▿

    Science.gov (United States)

    Almagro-Moreno, Salvador; Boyd, E. Fidelma

    2009-01-01

    Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae ΔnanA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment. PMID:19564383

  10. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

    Directory of Open Access Journals (Sweden)

    Andrés B Lantos

    2016-04-01

    Full Text Available Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully

  11. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

    Science.gov (United States)

    Lantos, Andrés B.; Carlevaro, Giannina; Araoz, Beatriz; Ruiz Diaz, Pablo; Camara, María de los Milagros; Buscaglia, Carlos A.; Bossi, Mariano; Yu, Hai; Chen, Xi; Bertozzi, Carolyn R.; Mucci, Juan; Campetella, Oscar

    2016-01-01

    Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form. PMID

  12. Disease mutations in CMP-sialic acid transporter SLC35A1 result in abnormal α-dystroglycan O-mannosylation, independent from sialic acid.

    Science.gov (United States)

    Riemersma, Moniek; Sandrock, Julia; Boltje, Thomas J; Büll, Christian; Heise, Torben; Ashikov, Angel; Adema, Gosse J; van Bokhoven, Hans; Lefeber, Dirk J

    2015-04-15

    Binding of cellular α-dystroglycan (α-DG) to its extracellular matrix ligands is fully dependent on a unique O-mannose-linked glycan. Disrupted O-mannosylation is the hallmark of the muscular dystrophy-dystroglycanopathy (MDDG) syndromes. SLC35A1, encoding the transporter of cytidine 5'-monophosphate-sialic acid, was recently identified as MDDG candidate gene. This is surprising, since sialic acid itself is dispensable for α-DG-ligand binding. In a novel SLC35A1-deficient cell model, we demonstrated a lack of α-DG O-mannosylation, ligand binding and incorporation of sialic acids. Removal of sialic acids from HAP1 wild-type cells after incorporation or preventing sialylation during synthesis did not affect α-DG O-mannosylation or ligand binding but did affect sialylation. Lentiviral-mediated complementation with the only known disease mutation p.Q101H failed to restore deficient O-mannosylation in SLC35A1 knockout cells and partly restored sialylation. These data indicate a role for SLC35A1 in α-DG O-mannosylation that is distinct from sialic acid metabolism. In addition, human SLC35A1 deficiency can be considered as a combined disorder of α-DG O-mannosylation and sialylation, a novel variant of the MDDG syndromes. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. ARLearn: augmented reality meets augmented virtuality

    NARCIS (Netherlands)

    Ternier, Stefaan; Klemke, Roland; Kalz, Marco; Van Ulzen, Patricia; Specht, Marcus

    2012-01-01

    Ternier, S., Klemke, R., Kalz, M., Van Ulzen, P., & Specht, M. (2012). ARLearn: augmented reality meets augmented virtuality [Special issue]. Journal of Universal Computer Science - Technology for learning across physical and virtual spaces, 18(15), 2143-2164.

  14. Sialic acid accelerates the electrophoretic velocity of injured dorsal root ganglion neurons

    National Research Council Canada - National Science Library

    Chen-xu Li Guo-ying Ma Min-fang Guo Ying Liu

    2015-01-01

    .... With the increase of membrane proteins on soma and injured site neurons, the negatively charged sialic acids bind to the external domains of membrane proteins, resulting in an increase of this charge...

  15. Encephalopathy caused by novel mutations in the CMP-sialic acid transporter, SLC35A1.

    Science.gov (United States)

    Ng, Bobby G; Asteggiano, Carla G; Kircher, Martin; Buckingham, Kati J; Raymond, Kimiyo; Nickerson, Deborah A; Shendure, Jay; Bamshad, Michael J; Ensslen, Matthias; Freeze, Hudson H

    2017-11-01

    Transport of activated nucleotide-sugars into the Golgi is critical for proper glycosylation and mutations in these transporters cause a group of rare genetic disorders termed congenital disorders of glycosylation. We performed exome sequencing on an individual with a profound neurological presentation and identified rare compound heterozygous mutations, p.Thr156Arg and p.Glu196Lys, in the CMP-sialic acid transporter, SLC35A1. Patient primary fibroblasts and serum showed a considerable decrease in the amount of N- and O-glycans terminating in sialic acid. Direct measurement of CMP-sialic acid transport into the Golgi showed a substantial decrease in overall rate of transport. Here we report the identification of the third patient with CMP-sialic acid transporter deficiency, who presented with severe neurological phenotype, but without hematological abnormalities. © 2017 Wiley Periodicals, Inc.

  16. CMP-Sialic Acid Synthetase: The Point of Constriction in the Sialylation Pathway.

    Science.gov (United States)

    Sellmeier, Melanie; Weinhold, Birgit; Münster-Kühnel, Anja

    2015-01-01

    Sialoglycoconjugates form the outermost layer of animal cells and play a crucial role in cellular communication processes. An essential step in the biosynthesis of sialylated glycoconjugates is the activation of sialic acid to the monophosphate diester CMP-sialic acid. Only the activated sugar is transported into the Golgi apparatus and serves as a substrate for the linkage-specific sialyltransferases. Interference with sugar activation abolishes sialylation and is embryonic lethal in mammals. In this chapter we focus on the enzyme catalyzing the activation of sialic acid, the CMP-sialic acid synthetase (CMAS), and compare the enzymatic properties of CMASs isolated from different species. Information concerning the reaction mechanism and active site architecture is included. Moreover, the unusual nuclear localization of vertebrate CMASs as well as the biotechnological application of bacterial CMAS enzymes is addressed.

  17. Sialic acid and iron content in breastmilk of Chinese lactating women

    National Research Council Canada - National Science Library

    Wang, Hong-Jiao; Hua, Chun-Zhen; Ruan, Li-Li; Hong, Li-Quan; Sheng, Shao-Qin; Shang, Shi-Qiang

    2017-01-01

    ... stages.Sialic acid and iron content of colostrum, transitional milk, mature milk, and involutional milk were determined using a neuraminidase assay kit and the ferrozine method, respectively in 88 lactating women (58 Term, 30 Preterm).The mean (SD...

  18. Opsonic function of sialic acid specific lectin in freshwater crab Paratelphusa jacquemontii

    National Research Council Canada - National Science Library

    Denis, Maghil; Thayappan, Karthigayani; Ramasamy, Sivakumar Mullivanam; Munusamy, Arumugam

    2015-01-01

    The sialic acid specific humoral lectin, Pjlec of the freshwater crab Paratelphusa jacquemontii was investigated for its opsonin function with rabbit erythrocyte as target cell for phagocytosis by the crab’s hemocyte...

  19. Examination of Signatures of Recent Positive Selection on Genes Involved in Human Sialic Acid Biology.

    Science.gov (United States)

    Moon, Jiyun M; Aronoff, David M; Capra, John A; Abbot, Patrick; Rokas, Antonis

    2018-02-21

    Sialic acids are nine carbon sugars ubiquitously found on the surfaces of vertebrate cells and are involved in various immune response-related processes. In humans, at least 58 genes spanning diverse functions, from biosynthesis and activation to recycling and degradation, are involved in sialic acid biology. Because of their role in immunity, sialic acid biology genes have been hypothesized to exhibit elevated rates of evolutionary change. Consistent with this hypothesis, several genes involved in sialic acid biology have experienced higher rates of non-synonymous substitutions in the human lineage than their counterparts in other great apes, perhaps in response to ancient pathogens that infected hominins millions of years ago (paleopathogens). To test whether sialic acid biology genes have also experienced more recent positive selection during the evolution of the modern human lineage, reflecting adaptation to contemporary cosmopolitan or geographically-restricted pathogens, we examined whether their protein-coding regions showed evidence of recent hard and soft selective sweeps. This examination involved the calculation of four measures that quantify changes in allele frequency spectra, extent of population differentiation, and haplotype homozygosity caused by recent hard and soft selective sweeps for 55 sialic acid biology genes using publicly available whole genome sequencing data from 1,668 humans from three ethnic groups. To disentangle evidence for selection from confounding demographic effects, we compared the observed patterns in sialic acid biology genes to simulated sequences of the same length under a model of neutral evolution that takes into account human demographic history. We found that the patterns of genetic variation of most sialic acid biology genes did not significantly deviate from neutral expectations and were not significantly different among genes belonging to different functional categories. Those few sialic acid biology genes that

  20. Correlation between haptoglobin and sialic acid or mucoprotein in diseased bovine serum.

    Science.gov (United States)

    Makimura, S; Usui, M

    1990-12-01

    The correlation between haptoglobin (Hp) and mucoprotein or sialic acid in sera from diseased cattle was examined to evaluate the clinical application of serum Hp. First, the ranges of mucoprotein, sialic acid and hemoglobin binding capacity (HbBC) of 46 healthy cattle were determined. Then, levels of these reactants in 35 cattle suffering from various diseases were measured. The frequency of the abnormal values was 94.3% in mucoprotein, 45.7% in sialic acid and 82.9% in HbBC in diseased cattle. There was a significant correlation between mucoprotein and sialic acid, and between HbBC and mucoprotein or sialic acid. Some correlation between mucoprotein and neutrophils or alpha-globulin was also observed. In spite of high levels of mucoprotein and sialic acid, lower HbBC than expected levels were often observed in inflammatory disorders. Such cases might be complicated with some hemolytic disorders such as piroplasmosis. Determining serum HbBC together with other acute phase reactants might be useful for evaluating inflammatory diseases complicated with hemolytic disorders.

  1. Sialic acids in squamous cell carcinoma of the head and neck

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    Izabela Bronikowska

    2016-12-01

    Full Text Available Altered glycosylation is a universal characteristic of cancer cells, and various types of glycan structures are well‑known markers of tumor progression and invasion. The present article discusses this aspect of the role of sialic acid, biosynthesis of sialylglycoconjugates and the genetic basis of its disorder, as well as the effects and the correlation between altered sialylation and clinical prognosis in head and neck squamous cell carcinoma (HNSCC.Only a few studies concerning the level of sialic acid in head and neck tumors have been conducted so far. The conclusions of the published reports dedicated to that problem confirm the presence of elevated levels of total sialic acid in these tumors. The authors do not always agree with the level of free or associated form of sialic acid correlated with tumor size, severity of the condition, and lymph nodes. Comparing the progress that has been made in the diagnosis and treatment of other cancers thanks to extensive work on the role of sialic acids, we come to the conclusion that only further detailed studies of this subject in relation to HNSCC are able to answer the question whether the extent of glycoforms of sialic acid may act as a tumor marker or target of immunotherapy.

  2. Association between salivary sialic acid and periodontal health status among smokers.

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    Jawzali, Jwan Ibrahim

    2016-07-01

    Smoking is an environmental risk factor causing poor dental health. Sialic acid is a salivary marker of oxidative stress for research of periodontal diseases. To identify diagnostic sialic acid fraction and its scavenger effect for periodontal diseases among smokers and periodental health status. This study carried out in the Khanzad specialized dental center - Erbil city. The study population is composed of 62 convenient samples. A structured interview questionnaire form was used to collect data about socio-demographic properties and smoking history. Clinical measurements were carried out to measure periodontal health status. Un-stimulated whole saliva samples were collected for measuring sialic acid fractions. Statistical package for social science (SPSS, version 18), was used for analysis and odds ratio. Risk of smoking increased significantly in young to mid ages, which included most of the current smokers, with periodontal diseases, and high total free sialic acid. Risk of periodontitis and teeth missing increased significantly by long duration of smoking, bad tooth brushing, and poor eating habits. Risk of teeth mobility and loss decreased significantly by early smoking cessation and low income. High levels of free sialic acid correlated significantly in current smokers with medium and deep pocket depth. Salivary free sialic acid may be used as a diagnostic oxidative stress biomarker for periodontal diseases among young current smokers. Cumulative destructive effect of long duration of smoking on the periodontum can be controlled by smoking cessation, good oral hygiene and diet habit in early old ages.

  3. Adeno-Associated Virus Serotype 4 (AAV4) and AAV5 Both Require Sialic Acid Binding for Hemagglutination and Efficient Transduction but Differ in Sialic Acid Linkage Specificity

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    Kaludov, Nikola; Brown, Kevin E.; Walters, Robert W.; Zabner, Joseph; Chiorini, John A.

    2001-01-01

    Adeno-associated virus serotype 4 (AAV4) and AAV5 have different tropisms compared to AAV2 and to each other. We recently reported that α2-3 sialic acid is required for AAV5 binding and transduction. In this study, we characterized AAV4 binding and transduction and found it also binds sialic acid, but the specificity is significantly different from AAV5. AAV4 can hemagglutinate red blood cells from several species, whereas AAV5 hemagglutinates only rhesus monkey red blood cells. Treatment of ...

  4. Assessment of total sialic acid levels in patients with hyperemesis gravidarum: a preliminary study.

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    Demir, Sevgi Sari; Özcan, Hüseyin Çağlayan; Balat, Özcan; Öztürk, Ebru; Uğur, Mete Gurol; Gündüz, Reyhan; Taysi, Seyithan

    2018-02-01

    To determine the levels of serum total sialic acid (TSA) in patients with hyperemesis gravidarum (HG) and their gestational age-matched controls. Thirty pregnant women with HG, and 30 healthy pregnant women at up to 14 weeks of gestation were enrolled in this preliminary study. Total sialic acid levels in maternal serum were measured using the quantitative sandwich ELISA method. We observed statistically significant difference in TSA levels between HG and the control groups (p = .003). The identification of the role of SA in the prediction, diagnosis and follow-up of HG warrants more comprehensive studies in the future. Impact Statement What is already known on this subject? The derivatives of neuraminic acid are collectively referred to as sialic acid (SA). Changes in SA levels are known to trigger various conditions and disorders, including inflammatory, cardiovascular, neurological and endocrine diseases. Although a sensitive test capable of identifying hyperemesis gravidarum (HG) would be useful for diagnosis purposes, such a test is currently not available. Studies focussing on identifying new potential indicators and biomarkers for HG - as well as identifying their relevance in establishing diagnosis and assessing disease severity - would not only assist in elucidating the underlying causes of this condition but would also contribute to the development of new diagnostic tests for HG. What the results of this study add? Total sialic acid levels are significantly higher in sera of the patients with HG. The present study is the first in the literature to assess total sialic acid levels in patients with HG and healthy pregnant women before 14 weeks of gestation. What the implications are of these findings for clinical practice and/or further research? Total sialic acid levels could give an idea to clinicians in the etiopathogenesis of HG. The identification of the role of sialic acid in the prediction, diagnosis and follow-up of HG warrants more

  5. Estimation of salivary sialic acid in oral premalignancy and oral squamous cell carcinoma

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    Vishakha Chaudhari

    2016-01-01

    Full Text Available Aims: Oral cancer is the most life-threatening disease of oral tissues. In societies where the incidence of oral cancer is high, clinically recognizable premalignant lesions are particularly common. Diagnosing oral cancers at an early stage is critical in improving the survival rate and reducing the morbidity associated with the disease. Alterations in the sialic acid levels in cancer patients have stimulated interest in this sugar residue as a possible tumor marker. Settings and Design: The purpose of this study was to estimate the salivary sialic acid levels in patients with oral premalignancy and squamous cell carcinoma and to correlate it with their grades to develop a cost-effective and noninvasive diagnostic parameter. Materials and Methods: Unstimulated whole saliva was collected from the groups under study and subjected to biochemical analysis for determination of sialic acid levels. Statistical Analysis Used: The salivary sialic acid levels were correlated with the clinical stage and histological grade by one-way ANOVA (SPSS software version 15. Results: Salivary sialic acid was elevated in oral squamous cell carcinoma (OSCC compared to oral premalignancy and control group. A statistically significant correlation was observed between the grades of squamous cell carcinoma, grades of dysplasia in premalignancy, and sialic acid level. Conclusion and Clinical Significance: Evaluation of salivary sialic acid levels in premalignant and malignant lesions can serve as a screening tool. The mortality and morbidity of OSCC can be reduced if the lesions are diagnosed in early precancerous states using such noninvasive diagnostic methods for screening and monitoring of the population.

  6. The sialic acid binding activity of the S protein facilitates infection by porcine transmissible gastroenteritis coronavirus

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    Enjuanes Luis

    2011-09-01

    Full Text Available Abstract Background Transmissible gastroenteritis virus (TGEV has a sialic acid binding activity that is believed to be important for enteropathogenicity, but that has so far appeared to be dispensable for infection of cultured cells. The aims of this study were to determine the effect of sialic acid binding for the infection of cultured cells under unfavorable conditions, and comparison of TGEV strains and mutants, as well as the avian coronavirus IBV concerning their dependence on the sialic acid binding activity. Methods The infectivity of different viruses was analyzed by a plaque assay after adsorption times of 5, 20, and 60 min. Prior to infection, cultured cells were either treated with neuraminidase to deplete sialic acids from the cell surface, or mock-treated. In a second approach, pre-treatment of the virus with porcine intestinal mucin was performed, followed by the plaque assay after a 5 min adsorption time. A student's t-test was used to verify the significance of the results. Results Desialylation of cells only had a minor effect on the infection by TGEV strain Purdue 46 when an adsorption period of 60 min was allowed for initiation of infection. However, when the adsorption time was reduced to 5 min the infectivity on desialylated cells decreased by more than 60%. A TGEV PUR46 mutant (HAD3 deficient in sialic acid binding showed a 77% lower titer than the parental virus after a 5 min adsorption time. After an adsorption time of 60 min the titer of HAD3 was 58% lower than that of TGEV PUR46. Another TGEV strain, TGEV Miller, and IBV Beaudette showed a reduction in infectivity after neuraminidase treatment of the cultured cells irrespective of the virion adsorption time. Conclusions Our results suggest that the sialic acid binding activity facilitates the infection by TGEV under unfavorable environmental conditions. The dependence on the sialic acid binding activity for an efficient infection differs in the analyzed TGEV strains.

  7. Role of extracellular sialic acid in regulation of neuronal and network excitability in the rat hippocampus.

    Science.gov (United States)

    Isaev, Dmytro; Isaeva, Elena; Shatskih, Tatiana; Zhao, Qian; Smits, Nicole C; Shworak, Nicholas W; Khazipov, Rustem; Holmes, Gregory L

    2007-10-24

    The extracellular membrane surface contains a substantial amount of negatively charged sialic acid residues. Some of the sialic acids are located close to the pore of voltage-gated channel, substantially influencing their gating properties. However, the role of sialylation of the extracellular membrane in modulation of neuronal and network activity remains primarily unknown. The level of sialylation is controlled by neuraminidase (NEU), the key enzyme that cleaves sialic acids. Here we show that NEU treatment causes a large depolarizing shift of voltage-gated sodium channel activation/inactivation and action potential (AP) threshold without any change in the resting membrane potential of hippocampal CA3 pyramidal neurons. Cleavage of sialic acids by NEU also reduced sensitivity of sodium channel gating and AP threshold to extracellular calcium. At the network level, exogenous NEU exerted powerful anticonvulsive action both in vitro and in acute and chronic in vivo models of epilepsy. In contrast, a NEU blocker (N-acetyl-2,3-dehydro-2-deoxyneuraminic acid) dramatically reduced seizure threshold and aggravated hippocampal seizures. Thus, sialylation appears to be a powerful mechanism to control neuronal and network excitability. We propose that decreasing the amount of extracellular sialic acid residues can be a useful approach to reduce neuronal excitability and serve as a novel therapeutic approach in the treatment of seizures.

  8. Polysialic acid bioengineering of neuronal cells by N-acyl sialic acid precursor treatment.

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    Pon, Robert A; Biggs, Nancy J; Jennings, Harold J

    2007-03-01

    The inherent promiscuity of the polysialic acid (PSA) biosynthetic pathway has been exploited by the use of exogenous unnatural sialic acid precursor molecules to introduce unnatural modifications into cellular PSA, and has found applications in nervous system development and tumor vaccine studies. The sialic acid precursor molecules N-propionyl- and N-butanoyl-mannosamine (ManPr, ManBu) have been variably reported to affect PSA biosynthesis ranging from complete inhibition to de novo production of modified PSA, thus illustrating the need for further investigation into their effects. In this study, we have used a monoclonal antibody (mAb) 13D9, specific to both N-propionyl-PSA and N-butanoyl-PSA (NPrPSA and NBuPSA), together with flow cytometry, to study precursor-treated tumor cells and NT2 neurons at different stages of their maturation. We report that both ManPr and ManBu sialic acid precursors are metabolized and the resultant unnatural sialic acids are incorporated into de novo surface sialylglycoconjugates in murine and human tumor cells and, for the first time, in human NT2 neurons. Furthermore, neither precursor treatment deleteriously affected endogenous PSA expression; however, with NT2 cells, PSA levels were naturally downregulated as a function of their maturation into polarized neurons independent of sialic acid precursor treatment.

  9. Bacterial periplasmic sialic acid-binding proteins exhibit a conserved binding site

    Energy Technology Data Exchange (ETDEWEB)

    Gangi Setty, Thanuja [Institute for Stem Cell Biology and Regenerative Medicine, NCBS Campus, GKVK Post, Bangalore, Karnataka 560 065 (India); Cho, Christine [Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109 (United States); Govindappa, Sowmya [Institute for Stem Cell Biology and Regenerative Medicine, NCBS Campus, GKVK Post, Bangalore, Karnataka 560 065 (India); Apicella, Michael A. [Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109 (United States); Ramaswamy, S., E-mail: ramas@instem.res.in [Institute for Stem Cell Biology and Regenerative Medicine, NCBS Campus, GKVK Post, Bangalore, Karnataka 560 065 (India)

    2014-07-01

    Structure–function studies of sialic acid-binding proteins from F. nucleatum, P. multocida, V. cholerae and H. influenzae reveal a conserved network of hydrogen bonds involved in conformational change on ligand binding. Sialic acids are a family of related nine-carbon sugar acids that play important roles in both eukaryotes and prokaryotes. These sialic acids are incorporated/decorated onto lipooligosaccharides as terminal sugars in multiple bacteria to evade the host immune system. Many pathogenic bacteria scavenge sialic acids from their host and use them for molecular mimicry. The first step of this process is the transport of sialic acid to the cytoplasm, which often takes place using a tripartite ATP-independent transport system consisting of a periplasmic binding protein and a membrane transporter. In this paper, the structural characterization of periplasmic binding proteins from the pathogenic bacteria Fusobacterium nucleatum, Pasteurella multocida and Vibrio cholerae and their thermodynamic characterization are reported. The binding affinities of several mutations in the Neu5Ac binding site of the Haemophilus influenzae protein are also reported. The structure and the thermodynamics of the binding of sugars suggest that all of these proteins have a very well conserved binding pocket and similar binding affinities. A significant conformational change occurs when these proteins bind the sugar. While the C1 carboxylate has been identified as the primary binding site, a second conserved hydrogen-bonding network is involved in the initiation and stabilization of the conformational states.

  10. Urinary excretion of sialic acid-containing saccharides in systemic lupus erythematosus.

    Science.gov (United States)

    Maury, C P; Sjöblom, C; Wegelius, O

    1981-09-01

    Urinary sialic acid-containing trisaccharides, total sialic acid, and serum sialic acid were studied in 17 patients with systemic lupus erythematosus (SLE) and in 15 healthy controls. The urinary excretion of sialyllactose, measured by a gas chromatographic method, was significantly greater in patients with SLE (37.4 +/- 21.4 mg/24 hours, SD) than in the control subjects (13.7 +/- 3.8 mg/24 hours, p less than 0.001). The mean excretion of sialyl-N-acetyllactosamine (16.6 +/- 8.5 mg/24 hours) and total sialic acid (82.5 +/- 29.4 mg/24 hours) was also greater in the SLE group than in the controls (8.7 +/- 2.8 and 58.0 +/- 16.0 mg/24 hours, respectively; p less than 0.01). Serum levels of sialic acid were correspondingly higher in the SLE patients (84.4 +/- 20.4 mg/100 ml) than in the controls (63.7 +/- 6.5 mg/100 ml, p less than 0.001). Urinary excretion of sialyl-lactose correlated positively with clinical disease activity (p less than 0.001) and with anti-DNA antibody levels (p less than 0.05). On the average, patients with moderate or severe disease excreted three times more sialyl-lactose than did those with mild or inactive disease. Our results suggest that the excretion of sialyl-oligosaccharides reflects disease activity in SLE.

  11. Sialic acid-triggered macroscopic properties switching on a smart polymer surface

    Science.gov (United States)

    Xiong, Yuting; Li, Minmin; Wang, Hongxi; Qing, Guangyan; Sun, Taolei

    2018-01-01

    Constructing smart surfaces with responsive polymers capable of dynamically and reversibly changing their chemical and physical properties by responding to the recognition of biomolecules remains a challenging task. And, the key to achieving this purpose relies on the design of polymers to precisely interact with the target molecule and successfully transform the interaction signal into tunable macroscopic properties, further achieve special bio-functions. Herein, inspired by carbohydrate-carbohydrate interaction (CCI) in life system, we developed a three-component copolymer poly(NIPAAm-co-PT-co-Glc) bearing a binding unit glucose (Glc) capable of recognizing sialic acid, a type of important molecular targets for cancer diagnosis and therapy, and reported the sialic acid triggered macroscopic properties switching on this smart polymer surface. Detailed mechanism studies indicated that multiple hydrogen bonding interactions between Glc unit and Neu5Ac destroyed the initial hydrogen bond network of the copolymer, leading to a reversible ;contraction-to-swelling; conformational transition of the copolymer chains, accompanied with distinct macroscopic property switching (i.e., surface wettability, morphology, stiffness) of the copolymer film. And these features enabled this copolymer to selectively capture sialic acid-containing glycopeptides from complex protein samples. This work provides an inspiration for the design of novel smart polymeric materials with sensitive responsiveness to sialic acid, which would promote the development of sialic acid-specific bio-devices and drug delivery systems.

  12. Porcine Milk Oligosaccharides and Sialic Acid Concentrations Vary Throughout Lactation.

    Science.gov (United States)

    Mudd, Austin T; Salcedo, Jaime; Alexander, Lindsey S; Johnson, Stacey K; Getty, Caitlyn M; Chichlowski, Maciej; Berg, Brian M; Barile, Daniela; Dilger, Ryan N

    2016-01-01

    Milk oligosaccharides (OSs) are bioactive components known to influence neonatal development. These compounds have specific physiological functions acting as prebiotics, immune system modulators, and enhancing intestine and brain development. The pig is a commonly used model for studying human nutrition, and there is interest in quantifying OS composition of porcine milk across lactation compared with human milk. In this study, we hypothesized that OS and sialic acid (SA) composition of porcine milk would be influenced by stage of lactation. Up to 250 mL of milk were collected from seven sows at each of three time points: day 0 (colostrum), days 7-9 (mature), and days 17-19 (weaning). Colostrum was collected within 6 h of farrowing and 3-day intervals were used for mature and weaning milk to ensure representative sampling. Milk samples were analyzed for OS profiles by Nano-LC Chip-QTOF MS, OS concentrations via HPAEC-PAD, and SA (total and free) was assessed by enzymatic reaction fluorescence detection. Sixty unique OSs were identified in porcine milk. Neutral OSs were the most abundant at each lactation stage (69-81%), followed by acidic-sialylated OSs (16-29%) and neutral-fucosylated OSs (2-4%). As lactation progressed, acidic OSs decreased (P = 0.003), whereas neutral-fucosylated (P mature milk in the pig, and SA concentrations shift from free to bound forms as lactation progresses. Our results suggest that although porcine milk OS concentration and the number of structures is lower than human milk, the OS profile appears to be closer to human milk rather than to bovine milk, based on previously published profiles.

  13. Gangliosides with O-acetylated sialic acids in tumors of neuroectodermal origin.

    Science.gov (United States)

    Kohla, Guido; Stockfleth, Eggert; Schauer, Roland

    2002-08-01

    Gangliosides, carrying an O-acetylated sialic acid in their carbohydrate moiety, are often found in growing and developing tissues, especially of neuro-ectodermal origin. The most prominent one is 9-O-Ac-GD3, which is considered as an oncofetal marker in animal and human tumors like neuronal tumors, melanoma, basalioma or breast cancer, as well as in psoriatic lesions. Also other gangliosides like GD2 or GT3 were found to be O-acetylated in their terminal sialic acid. In this review we are summarising the occurrence of such gangliosides in normal and transformed tissues and delineate a more general theory that O-acetylated sialic acids in gangliosides are a universal marker for growing cells and tissues.

  14. Sialic acid and cholesterol variations during oogenesis of an estuarine teleost

    Energy Technology Data Exchange (ETDEWEB)

    Veena, K.B.; Chacko, J. [Cochin, Univ. of Science and Technology (India). Dept. of Chemical Oceanography; Radhakrishnan, C.K. [Cochin, Univ. of Science and Technology (India). Dept. of Marine Biology. Biochemistry and Microbiology

    1995-12-31

    The pituitary gland, ovaries and blood of the three different stages of maturity of Etroplus maculatus (Bloch) were subjected to biochemical analysis. The changes in the concentrations of sialic acid in the pituitary gland and blood were observed to related oogenesis. A similar trend in concentrations of cholesterol in the ovary and blood were also observed. The amount of Sialic acid and cholesterol has been reported to give the measure of glycoprotein hormones in the pituitary gland (LICHT and PAPKOFF, 1972) and steroid hormones (NORRIS, 1985). The variation in the concentration of sialic acid and cholesterol in the tissues of the estuarine teleost Etroplus maculatus observed during oogenesis, emphasises their important roles during ovarian development.

  15. Regeneration of membrane sialic acid after neuraminidase treatment of leukemic granulocytes.

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    Taub, R N; Hindenburg, A A; Baker, M A

    1985-01-01

    Granulocytes from patients with chronic myelogenous leukemia (CML) were studied for their ability to regenerate surface sialic acid following treatment with Vibrio cholera neuraminidase (VCN) in vitro. Immediately after neuraminidase treatment, CML and normal granulocytes showed similar incorporation of radioactivity after surface labelling with sodium periodate/potassium-H3-borohydride (PI/BH3(4)). CML granulocytes treated with neuraminidase then incubated for 18 h in nutrient medium showed strikingly increased PI/BH3(4) labelling, usually greater than initial pretreatment values, consistent with a rapid reappearance of sialic acid in the cell membrane. This pattern was not seen in normal granulocytes. The aberrant regeneration of sialic acid in CML granulocytes in vitro could be inhibited by addition of 3 X 10(-6) M retinoic acid, suggesting either a direct effect on membrane glycoconjugate synthesis or an association with granulocyte differentiation.

  16. Histochemical properties of sialic acids and antimicrobial substances in canine anal glands

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    T. Nara

    2011-09-01

    Full Text Available The functional properties of sialic acids appear to be manifold. Additionally, antimicrobial substances serve as a non-specific defense against microorganisms. In this study, therefore, the localization of sialic acids and antimicrobial substances in the anal glands of dog was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium, luminal secretions and excretory ducts exhibited high levels of sialoglycoconjugates that terminated in Siaα2-6Gal/GalNAc or Siaα2-3Gal1-4GlcNAc. Additionally, O-acetylated sialic acids were detectable in these glandular structures. Antimicrobial substances, such as lysozyme, immunoglobulin A (IgA, lactoferrin and the peptide group of β-defensins, were also demonstrated as products of the anal glands. The results obtained are discussed with regard to the functional significance of the anal glands. These secretory products may create a defensive barrier against microbial invasion at the anal mucosa.

  17. Detection of Sialic Acid-Utilising Bacteria in a Caecal Community Batch Culture Using RNA-Based Stable Isotope Probing

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    Wayne Young

    2015-03-01

    Full Text Available Sialic acids are monosaccharides typically found on cell surfaces and attached to soluble proteins, or as essential components of ganglioside structures that play a critical role in brain development and neural transmission. Human milk also contains sialic acid conjugated to oligosaccharides, glycolipids, and glycoproteins. These nutrients can reach the large bowel where they may be metabolised by the microbiota. However, little is known about the members of the microbiota involved in this function. To identify intestinal bacteria that utilise sialic acid within a complex intestinal community, we cultured the caecal microbiota from piglets in the presence of 13C-labelled sialic acid. Using RNA-based stable isotope probing, we identified bacteria that consumed 13C-sialic acid by fractionating total RNA in isopycnic buoyant density gradients followed by 16S rRNA gene analysis. Addition of sialic acid caused significant microbial community changes. A relative rise in Prevotella and Lactobacillus species was accompanied by a corresponding reduction in the genera Escherichia/Shigella, Ruminococcus and Eubacterium. Inspection of isotopically labelled RNA sequences suggests that the labelled sialic acid was consumed by a wide range of bacteria. However, species affiliated with the genus Prevotella were clearly identified as the most prolific users, as solely their RNA showed significantly higher relative shares among the most labelled RNA species. Given the relevance of sialic acid in nutrition, this study contributes to a better understanding of their microbial transformation in the intestinal tract with potential implications for human health.

  18. Differential distribution of the JC virus receptor-type sialic acid in normal human tissues.

    Science.gov (United States)

    Eash, Sylvia; Tavares, Rosemarie; Stopa, Edward G; Robbins, Scott H; Brossay, Laurent; Atwood, Walter J

    2004-02-01

    JC virus (JCV), a member of the polyomavirus family, causes a demyelinating disease of the central nervous system (CNS) in humans known as progressive multifocal leukoencephalopathy. Although glial cells are the principal target of JCV productive infection in progressive multifocal leukoencephalopathy patients, little is known regarding the site of JCV persistence and the mechanisms by which the virus spreads to the CNS to cause disease. Previous work has demonstrated the presence of replicating JCV DNA in B lymphocytes from peripheral blood, tonsil, and spleen and it has been hypothesized that lymphocytes may be one site of JCV persistence. Detection of viral gene products in renal tubules and excretion of JC virions in the urine suggests JCV persistence in the kidney. A respiratory route of viral transmission has also been hypothesized implicating the lung as another possible site of persistent JCV infection. Earlier studies from our laboratory have shown that terminal alpha 2,6-linked sialic acid is a critical component of the JCV receptor. In this report we examined the tissue distribution of this JCV receptor-type sialic acid in a panel of normal human tissues. Our results demonstrate that in normal brain JCV receptor-type sialic acids are expressed on oligodendrocytes and astrocytes, but not on cortical neurons. The receptor-type sialic acid is also more highly expressed on B lymphocytes than on T lymphocytes in normal human spleen and tonsil. In addition, both the kidney and lung express abundant levels of alpha 2-6-linked sialic acids. Our data show a striking correlation between the expression of the JCV receptor-type sialic acid on cells and their susceptibility to infection by the virus. These findings also support the hypothesis of JCV persistence in lymphoid tissue and B-cell-facilitated viral dissemination to the CNS.

  19. A novel sugar analog enhances sialic acid production and biotherapeutic sialylation in CHO cells.

    Science.gov (United States)

    Yin, Bojiao; Wang, Qiong; Chung, Cheng-Yu; Bhattacharya, Rahul; Ren, Xiaozhi; Tang, Juechun; Yarema, Kevin J; Betenbaugh, Michael J

    2017-08-01

    A desirable feature of many therapeutic glycoprotein production processes is to maximize the final sialic acid content. In this study, the effect of applying a novel chemical analog of the sialic acid precursor N-acetylmannosamine (ManNAc) on the sialic acid content of cellular proteins and a model recombinant glycoprotein, erythropoietin (EPO), was investigated in CHO-K1 cells. By introducing the 1,3,4-O-Bu 3 ManNAc analog at 200-300 µM into cell culture media, the intracellular sialic acid content of EPO-expressing cells increased ∼8-fold over untreated controls while the level of cellular sialylated glycoconjugates increased significantly as well. For example, addition of 200-300 µM 1,3,4-O-Bu 3 ManNAc resulted in >40% increase in final sialic acid content of recombinant EPO, while natural ManNAc at ∼100 times higher concentration of 20 mM produced a less profound change in EPO sialylation. Collectively, these results indicate that butyrate-derivatization of ManNAc improves the capacity of cells to incorporate exogenous ManNAc into the sialic acid biosynthetic pathway and thereby increase sialylation of recombinant EPO and other glycoproteins. This study establishes 1,3,4-O-Bu 3 ManNAc as a novel chemical supplement to improve glycoprotein quality and sialylation levels at concentrations orders of magnitude lower than alternative approaches. Biotechnol. Bioeng. 2017;114: 1899-1902. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Relationship between Sialic acid and metabolic variables in Indian type 2 diabetic patients

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    Nayak B Shivananda

    2005-08-01

    Full Text Available Abstract Background Plasma sialic acid is a marker of the acute phase response. Objective is to study the relationship between sialic acid relationship with metabolic variables in Indian type 2 diabetes with and without microvascular complications. Research design and Methods Fasting Venous blood samples were taken from 200 subjects of which 50 were of diabetes mellitus (DM and nephropathy patients, 50 patients with type 2 diabetes and retinopathy, 50 patients with type 2 diabetes without any complications and 50 healthy individuals without diabetes. The Indian subject's aged 15–60 years with type 2 diabetes were recruited for the study. Simultaneously urine samples were also collected from each of the subjects. All the blood samples were analyzed for total cholesterol, triglyceride (TG, low-density lipoprotein (LDL, high-density lipoprotein (HDL, fasting and postprandial glucose on fully automated analyzer. Serum and urine sialic acid along with microalbumin levels were also estimated. Results There was a significantly increasing trend of plasma and urine sialic acid with severity of nephropathy (P 1c, serum triglyceride and cholesterol concentrations, waist-to-hip ratio and hypertension. Significant correlations were found between sialic acid concentration and cardiovascular risk factors like LDL and TG in the diabetic subjects. Conclusion The main finding of this study is that elevated serum and urinary sialic acid and microalbumin concentrations were strongly related to the presence of microvascular complications like diabetic nephropathy and retinopathy and cardiovascular risk factors in Indian type 2 diabetic subjects. Further study of acute-phase response markers and mediators as indicators or predictors of diabetic microvascular complications is therefore justified.

  1. Sialic acid-to-urea ratio as a measure of airway surface hydration.

    Science.gov (United States)

    Esther, Charles R; Hill, David B; Button, Brian; Shi, Shuai; Jania, Corey; Duncan, Elizabeth A; Doerschuk, Claire M; Chen, Gang; Ranganathan, Sarath; Stick, Stephen M; Boucher, Richard C

    2017-03-01

    Although airway mucus dehydration is key to pathophysiology of cystic fibrosis (CF) and other airways diseases, measuring mucus hydration is challenging. We explored a robust method to estimate mucus hydration using sialic acid as a marker for mucin content. Terminal sialic acid residues from mucins were cleaved by acid hydrolysis from airway samples, and concentrations of sialic acid, urea, and other biomarkers were analyzed by mass spectrometry. In mucins purified from human airway epithelial (HAE), sialic acid concentrations after acid hydrolysis correlated with mucin concentrations (r2 = 0.92). Sialic acid-to-urea ratios measured from filters applied to the apical surface of cultured HAE correlated to percent solids and were elevated in samples from CF HAEs relative to controls (2.2 ± 1.1 vs. 0.93 ± 1.8, P urea ratios were elevated in bronchoalveolar lavage fluid (BALF) from β-epithelial sodium channel (ENaC) transgenic mice, known to have reduced mucus hydration, and mice sensitized to house dust mite allergen. In a translational application, elevated sialic acid-to-urea ratios were measured in BALF from young children with CF who had airway infection relative to those who did not (5.5 ± 3.7 vs. 1.9 ± 1.4, P urea ratio performed similarly to percent solids, the gold standard measure of mucus hydration. The method proved robust and has potential to serve as flexible techniques to assess mucin hydration, particularly in samples like BALF in which established methods such as percent solids cannot be utilized. Copyright © 2017 the American Physiological Society.

  2. Sialic Acid Binding Properties of Soluble Coronavirus Spike (S1 Proteins: Differences between Infectious Bronchitis Virus and Transmissible Gastroenteritis Virus

    Directory of Open Access Journals (Sweden)

    Christine Winter

    2013-07-01

    Full Text Available The spike proteins of a number of coronaviruses are able to bind to sialic acids present on the cell surface. The importance of this sialic acid binding ability during infection is, however, quite different. We compared the spike protein of transmissible gastroenteritis virus (TGEV and the spike protein of infectious bronchitis virus (IBV. Whereas sialic acid is the only receptor determinant known so far for IBV, TGEV requires interaction with its receptor aminopeptidase N to initiate infection of cells. Binding tests with soluble spike proteins carrying an IgG Fc-tag revealed pronounced differences between these two viral proteins. Binding of the IBV spike protein to host cells was in all experiments sialic acid dependent, whereas the soluble TGEV spike showed binding to APN but had no detectable sialic acid binding activity. Our results underline the different ways in which binding to sialoglycoconjugates is mediated by coronavirus spike proteins.

  3. Porcine milk oligosaccharides and sialic acid concentrations vary throughout lactation

    Directory of Open Access Journals (Sweden)

    Austin T Mudd

    2016-09-01

    Full Text Available Background: Milk oligosaccharides (OS are bioactive components known to influence neonatal development. These compounds have specific physiological functions acting as prebiotics, immune system modulators, and enhancing intestine and brain development. Objectives: The pig is a commonly used model for studying human nutrition, and there is interest in characterizing and quantifying OS composition of porcine milk across lactation. In this study, we hypothesized that OS and sialic acid (SA composition of porcine milk would be influenced by stage of lactation. Methods: Up to 250 ml of milk was collected from 7 sows at each of three time points: d 0 (colostrum, d 7-9 (mature, and d 17-19 (weaning. Colostrum was collected within 6 h of farrowing and three-day intervals were used for mature and weaning milk to ensure representative sampling. Milk samples were analyzed for OS profiles by Nano LC Chip QTOF MS, OS concentrations via HPAEC-PAD, and SA (total and free was assessed by enzymatic reaction fluorescence detection.Results: Sixty unique OS were identified in porcine milk. Neutral OS were the most abundant at each lactation stage (69-81%, followed by acidic-sialylated OS (16-29% and neutral-fucosylated OS (2-4%. As lactation progressed, acidic OS decreased (P < 0.05, whereas neutral-fucosylated and neutral OS increased (P < 0.05 throughout lactation. Six OS were present in all samples analyzed across lactation (LDFH-I, 2´-FL, LNFP-I, LNnH, 3-Hex, 3´-SL, while LDFT was present only in colostrum samples. Analysis of individual OS concentrations indicated differences (P < 0.05 between days 0 and 7. Conversely, between days 7 and 18, OS concentrations remained stable with only LNnH and LNDFH-I decreasing (P < 0.05 over this period. Analysis of free SA indicated a decrease (P < 0.05 as lactation progressed, while bound and total SA increased (P < 0.05 across lactation. Conclusions: The present data suggest that while porcine milk OS profiles and

  4. Histochemical localization of sialic acids and antimicrobial substances in eccrine glands of porcine snout skin

    Directory of Open Access Journals (Sweden)

    K. Fukui

    2012-02-01

    Full Text Available The distribution of sialic acids and antimicrobial products (lysozyme, IgA, lactoferrin, β-defensin 2 as well as Rab3D in the eccrine glands of porcine snout skin was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium consisted of two types of secretory cells: dark and clear cells. The dark cells exhibited considerable amounts of sialoglycoconjugates, which included O-acetylated sialic acids, whereas sialic acids in the sequence Siaα2-3Gal1-4GlcNAc were confined to some of the dark cells. All antimicrobial substances and Rab3D were demonstrated to be also mainly present in some of the dark cells. Additionally, in the cytological and cytochemical features, the different characteristics were observed among the dark cells. The results obtained are discussed with regard to the functional significance of the eccrine glands. The secretory products elaborated by this gland type may function as protective agents in order to preserve the skin integrity of the snout region, considering that sialic acids and antimicrobial substances are important in general defense mechanisms.

  5. Sialic acid accelerates the electrophoretic velocity of injured dorsal root ganglion neurons.

    Science.gov (United States)

    Li, Chen-Xu; Ma, Guo-Ying; Guo, Min-Fang; Liu, Ying

    2015-06-01

    Peripheral nerve injury has been shown to result in ectopic spontaneous discharges on soma and injured sites of sensory neurons, thereby inducing neuropathic pain. With the increase of membrane proteins on soma and injured site neurons, the negatively charged sialic acids bind to the external domains of membrane proteins, resulting in an increase of this charge. We therefore speculate that the electrophoretic velocity of injured neurons may be faster than non-injured neurons. The present study established rat models of neuropathic pain via chronic constriction injury. Results of the cell electrophoresis test revealed that the electrophoretic velocity of injured neuronal cells was faster than that of non-injured (control) cells. We then treated cells with divalent cations of Ca(2+) and organic compounds with positive charges, polylysine to counteract the negatively charged sialic acids, or neuraminidase to specifically remove sialic acids from the membrane surface of injured neurons. All three treatments significantly reduced the electrophoretic velocity of injured neuronal cells. These findings suggest that enhanced sialic acids on injured neurons may accelerate the electrophoretic velocity of injured neurons.

  6. Manifold decrease of sialic acid synthase in fetal Down syndrome brain.

    Science.gov (United States)

    Gulesserian, T; Engidawork, E; Fountoulakis, M; Lubec, G

    2007-01-01

    Down syndrome (DS, trisomy 21) is the most common genetic cause of mental retardation. A large series of biochemical defects have been observed in fetal and adult DS brain that help in unraveling the molecular mechanisms underlying mental retardation. As sialylation of glycoconjugates plays an important role in brain development, this study aimed to look at the sialic acid metabolism by measuring sialic acid synthase (SAS; N-acetylneuraminate synthase) in early second trimester fetal control and DS brain. In this regard, protein profiling was performed by two-dimensional gel electrophoresis coupled to matrix-assisted laser desorption/ionization mass-spectrometry followed by database search and subsequent quantification of spot using specific software. SAS, the enzyme catalyzing synthesis of N-acetyl-neuraminic acid (syn: sialic acid) was represented as a single spot and found to be significantly and manifold reduced (P sialic acid metabolism, required for brain development and, more specifically, for sialylation of key brain proteins, including neuronal cell adhesion molecule and myelin associated glycoprotein.

  7. Sialic acid accelerates the electrophoretic velocity of injured dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Chen-xu Li

    2015-01-01

    Full Text Available Peripheral nerve injury has been shown to result in ectopic spontaneous discharges on soma and injured sites of sensory neurons, thereby inducing neuropathic pain. With the increase of membrane proteins on soma and injured site neurons, the negatively charged sialic acids bind to the external domains of membrane proteins, resulting in an increase of this charge. We therefore speculate that the electrophoretic velocity of injured neurons may be faster than non-injured neurons. The present study established rat models of neuropathic pain via chronic constriction injury. Results of the cell electrophoresis test revealed that the electrophoretic velocity of injured neuronal cells was faster than that of non-injured (control cells. We then treated cells with divalent cations of Ca 2+ and organic compounds with positive charges, polylysine to counteract the negatively charged sialic acids, or neuraminidase to specifically remove sialic acids from the membrane surface of injured neurons. All three treatments significantly reduced the electrophoretic velocity of injured neuronal cells. These findings suggest that enhanced sialic acids on injured neurons may accelerate the electrophoretic velocity of injured neurons.

  8. Intellectual disability and bleeding diathesis due to deficient CMP--sialic acid transport.

    Science.gov (United States)

    Mohamed, Miski; Ashikov, Angel; Guillard, Mailys; Robben, Joris H; Schmidt, Samuel; van den Heuvel, B; de Brouwer, Arjan P M; Gerardy-Schahn, Rita; Deen, Peter M T; Wevers, Ron A; Lefeber, Dirk J; Morava, Eva

    2013-08-13

    To identify the underlying genetic defect in a patient with intellectual disability, seizures, ataxia, macrothrombocytopenia, renal and cardiac involvement, and abnormal protein glycosylation. Genetic studies involved homozygosity mapping by 250K single nucleotide polymorphism array and SLC35A1 sequencing. Functional studies included biochemical assays for N-glycosylation and mucin-type O-glycosylation and SLC35A1-encoded cytidine 5'-monophosphosialic acid (CMP-sialic acid) transport after heterologous expression in yeast. We performed biochemical analysis and found combined N- and O-glycosylation abnormalities and specific reduction in sialylation in this patient. Homozygosity mapping revealed homozygosity for the CMP-sialic acid transporter SLC35A1. Mutation analysis identified a homozygous c.303G > C (p.Gln101His) missense mutation that was heterozygous in both parents. Functional analysis of mutant SLC35A1 showed normal Golgi localization but 50% reduction in transport activity of CMP-sialic acid in vitro. We confirm an autosomal recessive, generalized sialylation defect due to mutations in SLC35A1. The primary neurologic presentation consisting of ataxia, intellectual disability, and seizures, in combination with bleeding diathesis and proteinuria, is discriminative from a previous case described with deficient sialic acid transporter. Our study underlines the importance of sialylation for normal CNS development and regular organ function.

  9. Identification of new sialic acids derived from glycoproteins of bovine submandibular gland

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Reuter, G.; Pfeil, R.; Stoll, S.; Schauer, R.; Kamerling, J.P.; Versluis, C.

    1983-01-01

    Improvements in the isolation procedure and the analytical equipment enabled the detection of seven novel sialic acids in bovine submandibular gland glycoprotein: N-acetyl-8-O-acetylneuraminic acid, N-acetyl-8,9-di-O-acetylneuraminic acid, N-acetyl-7,8,9-tri-O-acetylneuraminic acid,

  10. [Variation of the sialic acid-protein ratio in the human cervical mucus (author's transl)].

    Science.gov (United States)

    Kesserü, E; Westphal, N

    1975-01-01

    Serial determinations of total protein and sialic acid concentrations were carried out in individual cervical mucus samples of normal women, throughout the menstrual cycle as well as under the influence of estrogen and progestagen steroids. Total protein was titrated by a modified micro-biuret method and sialic acid was determined using the "Direct Ehrlich" method. Both parameters diminished gradually during the follicular phase of the cycle with lowest values around the time of ovulation, and showed a strong increase during the luteal phase. Administration of ethinylestradiol yielded values significantly lower than those of normal ovulatory phase and under d-Nosgestrel treatment the values were significantly higher than in normal luteal phase. However the proportion of sialic acid as related to total protein showed an inverse behavior, i.e. increased under estrogenic and decreased under progestogenic influence. The cyclic and hormone-induced variations of this ratio were more specific than those of both separate components. Thus, estrogens produce an increase of the sialic acid containing fraction of cervical mucus proteins, while progestagens have an opposite effect. The role of these actions in reproductive physiology is discussed.

  11. Association between salivary sialic acid and periodontal health status among smokers

    Directory of Open Access Journals (Sweden)

    Jwan Ibrahim Jawzali

    2016-07-01

    Conclusion: Salivary free sialic acid may be used as a diagnostic oxidative stress biomarker for periodontal diseases among young current smokers. Cumulative destructive effect of long duration of smoking on the periodontum can be controlled by smoking cessation, good oral hygiene and diet habit in early old ages.

  12. Sialic Acids Attached to O-Glycans Modulate Voltage-gated Potassium Channel Gating*

    Science.gov (United States)

    Schwetz, Tara A.; Norring, Sarah A.; Ednie, Andrew R.; Bennett, Eric S.

    2011-01-01

    Neuronal, cardiac, and skeletal muscle action potentials are produced and conducted through the highly regulated activity of several types of voltage-gated ion channels. Voltage-gated potassium (Kv) channels are responsible for action potential repolarization. Glycans can be attached to glycoproteins through N- and O-linkages. Previous reports described the impact of N-glycans on voltage-gated ion channel function. Here, we show that sialic acids attached through O-linkages modulate gating of Kv2.1, Kv4.2, and Kv4.3. The conductance-voltage (G-V) relationships for each isoform were shifted uniquely by a depolarizing 8–16 mV under conditions of reduced sialylation. The data indicate that sialic acids modulate Kv channel activation through apparent electrostatic mechanisms that promote channel activity. Voltage-dependent steady-state inactivation was unaffected by changes in sialylation. N-Linked sialic acids cannot be responsible for the G-V shifts because Kv4.2 and Kv4.3 cannot be N-glycosylated, and immunoblot analysis confirmed Kv2.1 is not N-glycosylated. Glycosidase gel shift analysis suggested that Kv2.1, Kv4.2, and Kv4.3 were O-glycosylated and sialylated. To confirm this, azide-modified sugar residues involved specifically in O-glycan and sialic acid biosynthesis were shown to incorporate into all three Kv channel isoforms using Cu(I)-catalyzed cycloaddition chemistry. Together, the data indicate that sialic acids attached to O-glycans uniquely modulate gating of three Kv channel isoforms that are not N-glycosylated. These data provide the first evidence that external O-glycans, with core structures distinct from N-glycans in type and number of sugar residues, can modulate Kv channel function and thereby contribute to changes in electrical signaling that result from regulated ion channel expression and/or O-glycosylation. PMID:21115483

  13. Sensing the neuronal glycocalyx by glial sialic acid binding immunoglobulin-like lectins.

    Science.gov (United States)

    Linnartz-Gerlach, B; Mathews, M; Neumann, H

    2014-09-05

    Sialic acid binding immunoglobulin-like lectins (Siglecs) are cell surface receptors of microglia and oligodendrocytes that recognize the sialic acid cap of healthy neurons and neighboring glial cells. Upon ligand binding, Siglecs typically signal through an immunoreceptor tyrosine-based inhibition motif (ITIM) to keep the cell in a homeostatic status and support healthy neighboring cells. Siglecs can be divided into two groups; the first, being conserved among different species. The conserved Siglec-4/myelin-associated glycoprotein is expressed on oligodendrocytes and Schwann cells. Siglec-4 protects neurons from acute toxicity via interaction with sialic acids bound to neuronal gangliosides. The second group of Siglecs, named CD33-related Siglecs, is almost exclusively expressed on immune cells and is highly variable among different species. Microglial expression of Siglec-11 is human lineage-specific and prevents neurotoxicity via interaction with α2.8-linked sialic acid oligomers exposed on the neuronal glycocalyx. Microglial Siglec-E is a mouse CD33-related Siglec member that prevents microglial phagocytosis and the associated oxidative burst. Mouse Siglec-E of microglia binds to α2.8- and α2.3-linked sialic acid residues of the healthy glycocalyx of neuronal and glial cells. Recently, polymorphisms of the human Siglec-3/CD33 were linked to late onset Alzheimer's disease by genome-wide association studies. Human Siglec-3 is expressed on microglia and produces inhibitory signaling that decreases uptake of particular molecules such as amyloid-β aggregates. Thus, glial ITIM-signaling Siglecs recognize the intact glycocalyx of neurons and are involved in the modulation of neuron-glia interaction in healthy and diseased brain. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  14. Are humans prone to autoimmunity? Implications from evolutionary changes in hominin sialic acid biology.

    Science.gov (United States)

    Varki, Ajit

    2017-09-01

    Given varied intrinsic and extrinsic challenges to the immune system, it is unsurprising that each evolutionary lineage evolves distinctive features of immunoreactivity, and that tolerance mechanisms fail, allowing autoimmunity. Humans appear prone to many autoimmune diseases, with mechanisms both genetic and environmental. Another rapidly evolving biological system involves sialic acids, a family of monosaccharides that are terminal caps on cell surface and secreted molecules of vertebrates, and play multifarious roles in immunity. We have explored multiple genomic changes in sialic acid biology that occurred in human ancestors (hominins), some with implications for enhanced immunoreactivity, and hence for autoimmunity. Human ancestors lost the enzyme synthesizing the common mammalian sialic acid Neu5Gc, with an accumulation of the precursor sialic acid Neu5Ac. Resulting changes include an enhanced reactivity by some immune cells and increased ability of macrophages to kill bacteria, at the cost of increased endotoxin sensitivity. There are also multiple human-specific evolutionary changes in inhibitory and activating Siglecs, immune cell receptors that recognize sialic acids as "self-associated molecular patterns" (SAMPs) to modulate immunity, but can also be hijacked by pathogen molecular mimicry of SAMPs. Altered expression patterns and fixed or polymorphic SIGLEC pseudogenization in humans has modulated both innate and adaptive immunity, sometimes favoring over-reactivity. Meanwhile, dietary intake of Neu5Gc (derived primarily from red meats) allows metabolic incorporation of this non-human molecule into human cells--apparently the first example of "xeno-autoimmunity" involving "xeno-autoantigen" interactions with circulating "xeno-autoantibodies". Taken together, some of these factors may contribute to the apparent human propensity for autoimmunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Role of sialic acid in the kinetics of Streptococcus sanguis adhesion to artificial pellicle.

    Science.gov (United States)

    Cowan, M M; Taylor, K G; Doyle, R J

    1987-01-01

    Evaluation of the kinetics of adhesion of Streptococcus sanguis 10556 to saliva-coated hydroxylapatite revealed that sialic acid played a role in the formation of a stable cell-substratum complex. In a previous paper (M. M. Cowan, K. G. Taylor, and R. J. Doyle, J. Dent. Res. 65:1278-1283, 1986) the adhesion was found to take place in two distinct stages: a reversible equilibrium, probably governed by long-range forces, followed by a transition to higher-affinity binding. In the present study, artificial pellicle was treated with neuraminidase, and kinetic adsorption and desorption experiments with S. sanguis were conducted. The depletion of sialic acid from pellicle decreased the initial adsorption rate constant only slightly. The rate constant describing the initial desorption was unaffected. However, no transition to the second (high-affinity) association occurred. While S. sanguis desorption from control pellicles exhibited two sequential rates, with the second rate being approximately 10 times slower than the first, all desorption from sialo-deficient pellicles occurred at one rate that was equivalent to the initial rate constant for control desorption. The cells did not reach an equilibrium with the sialo-deficient pellicle, even after 6 h. Competing sialic acid did not decrease the rate or extent of adsorption, but desorption occurred to a greater extent when cells had adsorbed in the presence of sialic acid. These data suggest that sialic acid plays little role in the initial association of cell and pellicle but that it is necessary for the transition to high-affinity binding and the concomitant decreased propensity to desorb. Images PMID:3596799

  16. Racotumomab: an anti-idiotype vaccine related to N-glycolyl-containing gangliosides - preclinical and clinical data

    National Research Council Canada - National Science Library

    Vázquez, Ana M; Hernández, Ana M; Macías, Amparo; Montero, Enrique; Gómez, Daniel E; Alonso, Daniel F; Gabri, Mariano R; Gómez, Roberto E

    2012-01-01

    Neu-glycolyl (NeuGc)-containing gangliosides are attractive targets for immunotherapy with anti-idiotype mAbs, because these glycolipids are not normal components of the cytoplasmic membrane in humans...

  17. Confronting an augmented reality

    OpenAIRE

    John Hedberg; Robert Fitzgerald; James Steele; Anna Wilson; Matt Bacon; Danny Munnerley

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial...

  18. Adaptive Augmented Reality: Plasticity of Augmentations

    OpenAIRE

    Ghouaiel, Nehla; Cieutat, Jean-Marc; JESSEL, Jean-Pierre

    2014-01-01

    International audience; An augmented reality system is used to complete the real world with virtual objects (computer generated) so they seem to coexist in the same space as the real world. The concept of plasticity [4][5] was first introduced for Human Computer Interaction (HCI). It denotes the ability of an HCI interface to fit the context of use defined by the user, the environment and the platform. We believe that plasticity is a very important notion in the domain of augmented reality. T...

  19. First synthesis of a pentasaccharide moiety of ganglioside GAA-7 containing unusually modified sialic acids through the use of N-Troc-sialic acid derivative as a key unit.

    Science.gov (United States)

    Tamai, Hideki; Ando, Hiromune; Ishida, Hideharu; Kiso, Makoto

    2012-12-21

    The pentasaccharide part of the potent neuritogenic ganglioside GAA-7 has been synthesized for the first time. The unique branched terminus constituting partially modified sialic acids and N-acetylgalactosamine was successfully established by stereoselective double-sialylation using 8-O-methyl-N-Troc-sialic acid as a donor. The final 4 + 1 coupling reaction provided a high yield of pentasaccharide, which was deprotected to deliver the target molecule.

  20. Confronting an Augmented Reality

    Science.gov (United States)

    Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

  1. Chemoenzymatic synthesis of CMP-sialic acid derivatives by a one-pot two-enzyme system: comparison of substrate flexibility of three microbial CMP-sialic acid synthetases.

    Science.gov (United States)

    Yu, Hai; Yu, Hui; Karpel, Rebekah; Chen, Xi

    2004-12-15

    Three C terminal His6-tagged recombinant microbial CMP-sialic acid synthetases [EC 2.7.7.43] cloned from Neisseria meningitidis group B, Streptococcus agalactiae serotype V, and Escherichia coli K1, respectively, were evaluated for their ability in the synthesis of CMP-sialic acid derivatives in a one-pot two-enzyme system. In this system, N-acetylmannosamine or mannose analogs were condensed with pyruvate, catalyzed by a recombinant sialic acid aldolase [EC 4.1.3.3] cloned from E. coli K12 to provide sialic acid analogs as substrates for the CMP-sialic acid synthetases. The substrate flexibility and the reaction efficiency of the three recombinant CMP-sialic acid synthetases were compared, first by qualitative screening using thin layer chromatography, and then by quantitative analysis using high performance liquid chromatography. The N. meningitidis synthetase was shown to have the highest expression level, the most flexible substrate specificity, and the highest catalytic efficiency among the three synthetases. Finally, eight sugar nucleotides, including cytidine 5'-monophosphate N-acetylneuraminic acid (CMP-Neu5Ac) and its derivatives with substitutions at carbon-5, carbon-8, or carbon-9 of Neu5Ac, were synthesized in a preparative (100-200 mg) scale from their 5- or 6-carbon sugar precursors using the N. meningitidis synthetase and the aldolase.

  2. Specific synthesis of neurostatin and gangliosides O-acetylated in the outer sialic acids using a sialate transferase.

    Directory of Open Access Journals (Sweden)

    Lorenzo Romero-Ramírez

    Full Text Available Gangliosides are sialic acid containing glycosphingolipids, commonly found on the outer leaflet of the plasma membrane. O-acetylation of sialic acid hydroxyl groups is one of the most common modifications in gangliosides. Studies on the biological activity of O-acetylated gangliosides have been limited by their scarcity in nature. This comparatively small change in ganglioside structure causes major changes in their physiological properties. When the ganglioside GD1b was O-acetylated in the outer sialic acid, it became the potent inhibitor of astroblast and astrocytoma proliferation called Neurostatin. Although various chemical and enzymatic methods to O-acetylate commercial gangliosides have been described, O-acetylation was nonspecific and produced many side-products that reduced the yield. An enzyme with O-acetyltransferase activity (SOAT has been previously cloned from the bacteria Campylobacter jejuni. This enzyme catalyzed the acetylation of oligosaccharide-bound sialic acid, with high specificity for terminal alpha-2,8-linked residues. Using this enzyme and commercial gangliosides as starting material, we have specifically O-acetylated the gangliosides' outer sialic acids, to produce the corresponding gangliosides specifically O-acetylated in the sialic acid bound in alpha-2,3 and alpha-2,8 residues. We demonstrate here that O-acetylation occurred specifically in the C-9 position of the sialic acid. In summary, we present a new method of specific O-acetylation of ganglioside sialic acids that permits the large scale preparation of these modified glycosphingolipids, facilitating both, the study of their mechanism of antitumoral action and their use as therapeutic drugs for treating glioblastoma multiform (GBM patients.

  3. Sialic acid metabolism is involved in the regulation of gene expression during neuronal differentiation of PC12 cells.

    Science.gov (United States)

    Kontou, Maria; Bauer, Christian; Reutter, Werner; Horstkorte, Rüdiger

    2008-04-01

    Sialic acid precursors are mediators of the sialic acid pathway. In this manuscript we present evidence that the application of sialic acid a precursor modulates gene expression and cell differentiation. The concept that sugars are involved in cellular transcription was first proposed by Jacob and Monod nearly 40 years ago studying the regulation of the lac-operon in prokaryotes. Surprisingly, these findings have never been transferred to eukaryotic systems. For our studies we have chosen PC12 cells. PC12-cells differentiate after application of NGF into a neuron-like phenotype. It is shown that treatment of PC12 cells with two different sialic acid precursors N-acetyl- or N-propanoylmannosamine, without application of NGF also induces neurite outgrowth. Moreover, the PC12 cells show the same morphology as the NGF-treated cells. Surprisingly, after application of both sialic acid precursors the phosphorylation and translocation of erk1/2 into the nucleus are activated, thus influencing the expression of genes involved in the differentiation of cells, such as the transcription factor c-Jun or TOAD-64/Ulip/CRMP (Turned ON After Division, 64 kd/ unc-33-like phosphoprotein/Collapsin Response Mediator Protein). These are the first experimental data showing that the sialic acid metabolism is closely associated with signal transduction and regulation of neuronal differentiation.

  4. Glycoprotein 340 and sialic acid in minor-gland and whole saliva of children, adolescents, and adults.

    Science.gov (United States)

    Sonesson, Mikael; Ericson, Dan; Kinnby, Bertil; Wickström, Claes

    2011-12-01

    Glycoprotein 340 (gp-340) is a bacterial-binding glycoprotein found in major-gland and minor-gland saliva. Sialic acid, a common terminal structure of salivary glycoproteins, interacts with microorganisms and host ligands, as well as with free radicals. This study investigated the contents of gp-340 and sialic acid in minor-gland saliva and whole saliva of children (3 yr of age), adolescents (14 yr of age), and adults (20-25 yr of age). Labial-gland saliva and buccal-gland saliva were collected on filter paper, and unstimulated whole saliva was collected by draining into a tube. The relative amount of gp-340 and sialic acid was determined by ELISA and by enzyme-linked lectin assay (ELLA), respectively. In minor-gland saliva, no statistically significant differences in gp-340 and sialic acid were seen between the age-groups. Among adults, significantly lower amounts of gp-340 and sialic acid were seen in labial saliva compared with buccal saliva. In whole saliva, the amount of gp-340 was significantly lower among adults compared with children. No differences between genders were seen. Stable content of gp-340 and sialic acid in minor-gland saliva across the age-groups, and a higher content of gp-340 in the whole saliva of the youngest age-group (3-yr-olds) compared with the adult group, may reflect that those components are vital innate factors of immunity in children's saliva. © 2011 Eur J Oral Sci.

  5. Chemoenzymatic synthesis and enzymatic analysis of 8-modified cytidine monophosphate-sialic acid and sialyl lactose derivatives.

    Science.gov (United States)

    Morley, Thomas J; Withers, Stephen G

    2010-07-14

    The sialic acids found on eukaryotic glycans have remarkably diverse core structures, with a range of modifications at C5, C7, C8 and C9. These carbohydrates have been found to play key roles in cell-cell interactions within eukaryotes and often serve as the initial site of attachment for viruses and bacteria. Consequently simple changes to the structures of the sialic acids can result in profoundly different and often opposing biological effects. Of particular importance are modifications at the 8-position. These include O-acetylation, carried out by an acetyl transferase, and particularly polysialylation, catalyzed by a polysialyltransferase. As part of a structural and mechanistic study of sialyltransferases and polysialyltransferases, access was needed to sialic acid-containing oligosaccharides that are modified at the 8-position of the sialic acid to render this center non-nucleophilic. The free 8-modified sialic acid analogues were synthesized using a concise, divergent chemical synthetic approach, and each was converted to its cytidine monophosphate (CMP) sugar donor form using a bacterial CMP-sialic acid synthetase. The transfer of each of the modified donors to lactose by each of two sialyltransferases was investigated, and kinetic parameters were determined. These yielded insights into the roles of interactions occurring at that position during enzymatic sialyl transfer. A transferase from Campylobacter jejuni was identified as the most suitable for the enzymatic coupling and utilized to synthesize the 8''-modified sialyl lactose trisaccharides in multimilligram amounts.

  6. Sialic Acid Is Required for Neuronal Inhibition by Soluble MAG but not for Membrane Bound MAG

    Science.gov (United States)

    Al-Bashir, Najat; Mellado, Wilfredo; Filbin, Marie T.

    2016-01-01

    Myelin-Associated Glycoprotein (MAG), a major inhibitor of axonal growth, is a member of the immunoglobulin (Ig) super-family. Importantly, MAG (also known as Siglec-4) is a member of the Siglec family of proteins (sialic acid-binding, immunoglobulin-like lectins), MAG binds to complex gangliosides, specifically GD1a and/or GT1b. Therefore, it has been proposed as neuronal receptors for MAG inhibitory effect of axonal growth. Previously, we showed that MAG binds sialic acid through domain 1 at Arg118 and is able to inhibit axonal growth through domain 5. We developed a neurite outgrowth (NOG) assay, in which both wild type MAG and mutated MAG (MAG Arg118) are expressed on cells. In addition we also developed a soluble form NOG in which we utilized soluble MAG-Fc and mutated MAG (Arg118-Fc). Only MAG-Fc is able to inhibit NOG, but not mutated MAG (Arg118)-Fc that has been mutated at its sialic acid binding site. However, both forms of membrane bound MAG- and MAG (Arg118)- expressing cells still inhibit NOG. Here, we review various results from different groups regarding MAG’s inhibition of axonal growth. Also, we propose a model in which the sialic acid binding is not necessary for the inhibition induced by the membrane form of MAG, but it is necessary for the soluble form of MAG. This finding highlights the importance of understanding the different mechanisms by which MAG inhibits NOG in both the soluble fragmented form and the membrane-bound form in myelin debris following CNS damage. PMID:27065798

  7. Sialic acid accelerates the electrophoretic velocity of injured dorsal root ganglion neurons

    OpenAIRE

    Chen-xu Li; Guo-ying Ma; Min-fang Guo; Ying Liu

    2015-01-01

    Peripheral nerve injury has been shown to result in ectopic spontaneous discharges on soma and injured sites of sensory neurons, thereby inducing neuropathic pain. With the increase of membrane proteins on soma and injured site neurons, the negatively charged sialic acids bind to the external domains of membrane proteins, resulting in an increase of this charge. We therefore speculate that the electrophoretic velocity of injured neurons may be faster than non-injured neurons. The present stud...

  8. The lysosomal sialic acid transporter sialin is required for normal CNS myelination.

    Science.gov (United States)

    Prolo, Laura M; Vogel, Hannes; Reimer, Richard J

    2009-12-09

    Salla disease and infantile sialic acid storage disease are autosomal recessive lysosomal storage disorders caused by mutations in the gene encoding sialin, a membrane protein that transports free sialic acid out of the lysosome after it is cleaved from sialoglycoconjugates undergoing degradation. Accumulation of sialic acid in lysosomes defines these disorders, and the clinical phenotype is characterized by neurodevelopmental defects, including severe CNS hypomyelination. In this study, we used a sialin-deficient mouse to address how loss of sialin leads to the defect in myelination. Behavioral analysis of the sialin(-/-) mouse demonstrates poor coordination, seizures, and premature death. Analysis by histology, electron microscopy, and Western blotting reveals a decrease in myelination of the CNS but normal neuronal cytoarchitecture and normal myelination of the PNS. To investigate potential mechanisms underlying CNS hypomyelination, we studied myelination and oligodendrocyte development in optic nerves. We found reduced numbers of myelinated axons in optic nerves from sialin(-/-) mice, but the myelin that was present appeared grossly normal. Migration and density of oligodendrocyte precursor cells were normal; however, a marked decrease in the number of postmitotic oligodendrocytes and an associated increase in the number of apoptotic cells during the later stages of myelinogenesis were observed. These findings suggest that a defect in maturation of cells in the oligodendrocyte lineage leads to increased apoptosis and underlies the myelination defect associated with sialin loss.

  9. Biosynthetic incorporation of unnatural sialic acids into polysialic acid on neural cells.

    Science.gov (United States)

    Charter, N W; Mahal, L K; Koshland, D E; Bertozzi, C R

    2000-10-01

    In this study we demonstrate that polysialyltransferases are capable of accepting unnatural substrates in terminally differentiated human neurons. Polysialyltransferases catalyze the glycosylation of the neural cell adhesion molecule (NCAM) with polysialic acid (PSA). The unnatural sialic acid analog, N-levulinoyl sialic acid (SiaLev), was incorporated into cell surface glycoconjugates including PSA by the incubation of cultured neurons with the metabolic precursor N-levulinoylmannosamine (ManLev). The ketone group within the levulinoyl side chain of SiaLev was then used as a chemical handle for detection using a biotin probe. The incorporation of SiaLev residues into PSA was demonstrated by protection from sialidases that can cleave natural sialic acids but not those bearing unnatural N-acyl groups. The presence of SiaLev groups on the neuronal cell surface did not impede neurite outgrowth or significantly affect the distribution of PSA on neuronal compartments. Since PSA is important in neural plasticity and development, this mechanism for modulating PSA structure might be useful for functional studies.

  10. Sialic acid contributes to hyperexcitability of dorsal root ganglion neurons in rats with peripheral nerve injury.

    Science.gov (United States)

    Peng, Xiao-Qing; Zhang, Xiu-Lin; Fang, Yan; Xie, Wen-Rui; Xie, Yi-Kuan

    2004-11-12

    Axonal injury of the dorsal root ganglion (DRG) neurons may alter the synthesis of certain membrane proteins that are responsible for the development of abnormal hyperexcitability. The external domains of most of these membrane proteins are sialylated. Because sialic acid carries heavy negative charges, the increase of sialylated proteins may increase neurons' negative surface charges, which will have predictable effects on the voltage-gated channels, and affect the excitability of injured neurons. Using intracellular electrophysiological recording, we demonstrated that following chronic constriction injury (CCI) of the sciatic nerve, Aalpha/beta DRG neurons become hyperexcitable, as indicated by a more depolarized resting membrane potential (Vm) and a lowered threshold current (TIC). More interestingly, the excitability of injured DRG neurons was reduced substantially when the extracellular sialic acid was removed by pretreatment with neuraminidase. The Vm was less depolarized and the TIC increased robustly as compared to the CCI neurons without neuraminidase treatment. However, desialylation of normal, intact neurons had no significant effect on the Vm and less effect on the TIC. Our results suggest that the hyperexcitability of injured sensory neurons may be associated with increased negatively charged sialic acid residues on the surface of the neuronal somata.

  11. Augmented reality: a review.

    Science.gov (United States)

    Berryman, Donna R

    2012-01-01

    Augmented reality is a technology that overlays digital information on objects or places in the real world for the purpose of enhancing the user experience. It is not virtual reality, that is, the technology that creates a totally digital or computer created environment. Augmented reality, with its ability to combine reality and digital information, is being studied and implemented in medicine, marketing, museums, fashion, and numerous other areas. This article presents an overview of augmented reality, discussing what it is, how it works, its current implementations, and its potential impact on libraries.

  12. Myelin-associated Glycoprotein Interacts with Neurons via a Sialic Acid Binding Site at ARG118 and a Distinct Neurite Inhibition Site

    OpenAIRE

    Tang, Song; Shen, Ying Jing; DeBellard, Maria Elena; Mukhopadhyay, Gitali; Salzer, James L.; Crocker, Paul R.; Filbin, Marie T.

    1997-01-01

    Inhibitory components in myelin are largely responsible for the lack of regeneration in the mammalian CNS. Myelin-associated glycoprotein (MAG), a sialic acid binding protein and a component of myelin, is a potent inhibitor of neurite outgrowth from a variety of neurons both in vitro and in vivo. Here, we show that MAG's sialic acid binding site is distinct from its neurite inhibitory activity. Alone, sialic acid–dependent binding of MAG to neurons is insufficient to effect inhibition of axon...

  13. Augmenting the access grid using augmented reality

    Science.gov (United States)

    Li, Ying

    2012-01-01

    The Access Grid (AG) targets an advanced collaboration environment, with which multi-party group of people from remote sites can collaborate over high-performance networks. However, current AG still employs VIC (Video Conferencing Tool) to offer only pure video for remote communication, while most AG users expect to collaboratively refer and manipulate the 3D geometric models of grid services' results in live videos of AG session. Augmented Reality (AR) technique can overcome the deficiencies with its characteristics of combining virtual and real, real-time interaction and 3D registration, so it is necessary for AG to utilize AR to better assist the advanced collaboration environment. This paper introduces an effort to augment the AG by adding support for AR capability, which is encapsulated in the node service infrastructure, named as Augmented Reality Service (ARS). The ARS can merge the 3D geometric models of grid services' results and real video scene of AG into one AR environment, and provide the opportunity for distributed AG users to interactively and collaboratively participate in the AR environment with better experience.

  14. Metabolism of sialic acids from exogenously administered sialyllactose and mucin in mouse and rat.

    Science.gov (United States)

    Nöhle, U; Schauer, R

    1984-12-01

    A mixture of N-acetyl-[4,5,6,7,8,9-14C]neuraminosyl-alpha (2-3(6]-galactosyl-beta (1-4-glucose[( 14C]sialyl-lactose) and N-acetylneuraminosyl-alpha (2-3(6]-galactosyl-beta(1-4)-glucit-1-[3H]ol(sialyl-[3H]lactitol) as well as porcine submandibular gland mucin labeled with N-acetyl- and N-glycoloyl-[9-(3)H]neuraminic acid were administered orally to mice. The distribution of the different isotopes was followed in blood, tissues and excretion products of the animals. One half of the [14C]sialyl-lactose/sialyl-[3H]lactitol mixture given orally was excreted unchanged in the urine. The other half was hydrolysed by sialidase and partly metabolized further, followed by the excretion of 30% of the 14C-radioactivity as free N-acetyl-[4,5,6,7,8,9-14C]neuraminic acid and 60% of this radioactivity in the form of non-anionic compounds including expired 14CO2 within 24 h. The 14C-radioactivity derived from the [14C]sialyl-lactose/sialyl-[3H]lactitol mixture which remained in the bodies of fasted mice after 24 h was less than 1%. In the case of well-fed mice, a higher amount of the sialic acid residues was metabolized. The bulk of radioactivity of the mucin was resorbed within 24 h. About 40% of the radioactivity administered was excreted by the urine within 48 h; 30% of this radioactivity represented sialic acid and 70% other anionic and non-anionic metabolic products. 60% of the radioactivity administered remained in the body, and bound 3H-labeled sialic acids were isolated from liver. Sialyl-alpha (2-3)-[3H]lactitol was injected intravenously into rats; the substance was rapidly excreted in the urine without decomposition. These studies show that part of the sialic acids bound to oligosaccharides and glycoproteins can be hydrolysed in intestine by sialidase and be resorbed. This is followed either by excretion as free sialic acid or by metabolization at variable degrees, which apparently depends on the compound fed and on the retention time in the digestive tract.

  15. Interactive augmented reality

    OpenAIRE

    Moret Gabarró, Roger

    2010-01-01

    Projecte final de carrera realitzat en col.laboració amb el Royal Institute of Technology Augmented reality can provide a new experience to users by adding virtual objects where they are relevant in the real world. The new generation of mobile phones offers a platform to develop augmented reality application for industry as well as for the general public. Although some applications are reaching commercial viability, the technology is still limited. The main problem designers have to face w...

  16. Confronting an augmented reality

    Directory of Open Access Journals (Sweden)

    John Hedberg

    2012-08-01

    Full Text Available How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial augmentation of reality links to existing theories of education and learning, focusing on ideas of cognitive dissonance and the confrontation of new realities implied by exposure to new and varied perspectives. We also discuss connections with broader debates brought on by the social and cultural changes wrought by the increased digitalisation of our lives, especially the concept of the extended mind. Rather than offer a prescription for augmentation, our intention is to throw open debate and to provoke deep thinking about what interacting with and creating an augmented reality might mean for both teacher and learner.

  17. Determination of sialic acids in the nervous system of silkworm (Bombyx mori L.: Effects of aging and development

    Directory of Open Access Journals (Sweden)

    Soya Seçkin

    2017-01-01

    Full Text Available Sialic acids mainly occur as components on cell surface glycoproteins and glycolipids. They play a major role in the chemical and biological diversity of glycoconjugates. Although sialic acids exhibit great structural variability in vertebrates, glycoconjugates with sialic acids have also been determined in small amounts in invertebrates. It has been suggested that sialic acids play important roles in the development and function of the nervous system. Despite Bombyx mori being a model organism for the investigation of many physiological processes, sialic acid changes in its nervous system have not been examined during development and aging. Therefore, in this study we aimed to determine sialic acid changes in the nervous system of Bombyx mori during development and aging processes. Liquid chromatography-mass spectrometry (LC-MS and lectin immunohistochemistry were carried out in order to find variations among different developmental stages. Developmental stages were selected as 3rd instar (the youngest and 5th larval instar (young, motionless prepupa (the oldest and 13-day-old pupa (adult development. At all stages, only Neu5Ac was present, however, it dramatically decreased during the developmental and aging stages. On the other hand, an increase was observed in the amount of Neu5Ac during the pupal stage. In immunohistochemistry experiments with Maackia amurensis agglutinin (MAA and Sambucus nigra agglutinin (SNA lectins, the obtained staining was consistent with the obtained LC-MS results. These findings indicate that sialic acids are abundant at the younger stages but that they decrease in the insect nervous system during development and aging, similarly as in mammals.

  18. DmSAS is required for sialic acid biosynthesis in cultured Drosophila third instar larvae CNS neurons.

    Science.gov (United States)

    Granell, Annelise E von Bergen; Palter, Karen B; Akan, Ihan; Aich, Udayanath; Yarema, Kevin J; Betenbaugh, Michael J; Thornhill, William B; Recio-Pinto, Esperanza

    2011-11-18

    Sialylation is an important carbohydrate modification of glycoconjugates that has been shown to modulate many cellular/molecular interactions in vertebrates. In Drosophila melanogaster (Dm), using sequence homology, several enzymes of the sialylation pathway have been cloned and their function tested in expression systems. Here we investigated whether sialic acid incorporation in cultured Dm central nervous system (CNS) neurons required endogenously expressed Dm sialic acid synthase (DmSAS). We compared neurons derived from wild type Dm larvae with those containing a DmSAS mutation (148 bp deletion). The ability of these cells to produce Sia5NAz (sialic acid form) from Ac(4)ManNAz (azide-derivatized N-acetylmannosamine) and incorporate it into their glycoconjugates was measured by tagging the azide group of Sia5NAz with fluorescent agents via Click-iT chemistry. We found that most of the wild type Dm CNS neurons incorporated Sia5NAz into their glycoconjugates. Sialic acid incorporation was higher at the soma than at the neurite and could also be detected at perinuclear regions and the plasma membrane. In contrast, neurons from the DmSAS mutant did not incorporate Sia5NAz unless DmSAS was reintroduced (rescue mutant). Most of the neurons expressed α2,6-sialyltransferase. These results confirm that the mutation was a null mutation and that no redundant sialic acid biosynthetic activity exists in Dm cells, i.e., there is only one DmSAS. They also provide the strongest proof to date that DmSAS is a key enzyme in the biosynthesis of sialic acids in Dm CNS neurons, and the observed subcellular distribution of the newly synthesized sialic acids offers insights into their biological function.

  19. Estimation and comparative study of serum total sialic acid levels as tumor markers in oral cancer and precancer

    Directory of Open Access Journals (Sweden)

    Joshi Manjiri

    2010-01-01

    Full Text Available Background: Tumor markers are a major part of the secondary prevention and thus the detection of malignancies. Neoplasms often have an increased concentration of sialic acid on the tumor cell surface and are shed or secreted by some of these cells which increase the concentration in blood. Materials and Methods: The study was conducted on 90 subjects equally divided into three groups viz, healthy individuals, oral cancer and precancer. The estimation of serum total sialic acid level was done according to Plucinsky et al by resorcinol reagent method. The statistical analysis was carried out by using SPSS 10.0 software. Results: The mean serum total sialic acid (TSA level in oral precancer and oral cancer group was statistically significant (P<0.05. In oral cancer group when stage I and stage II were compared with stage III and stage IV, it was statistically significant (P<0.05. Histopathologically, oral cancer and precancer did not show statistically significant values (P>0.05. The present study also suggested that no correlation exists between habit of tobacco chewing / betel nut chewing / smoking or alcohol consumption with that of serum total sialic acid levels. Conclusion: Serum total sialic acid levels can be used as an adjunctive diagnostic marker in head and neck cancer.

  20. Exploring the mechanism of beta-amyloid toxicity attenuation by multivalent sialic acid polymers through the use of mathematical models.

    Science.gov (United States)

    Cowan, Christopher B; Patel, Dhara A; Good, Theresa A

    2009-05-21

    beta-Amyloid peptide (A beta), the primary protein component in senile plaques associated with Alzheimer's disease (AD), has been implicated in neurotoxicity associated with AD. Previous studies have shown that the A beta-neuronal membrane interaction plays a role in the mechanism of A beta toxicity. More specifically, it is thought that A beta interacts with ganglioside rich and sialic acid rich regions of cell surfaces. In light of such evidence, we have used a number of different sialic acid compounds of different valency or number of sialic acid moieties per molecule to attenuate A beta toxicity in a cell culture model. In this work, we proposed various mathematical models of A beta interaction with both the cell membrane and with the multivalent sialic acid compounds, designed to act as membrane mimics. These models allow us to explore the mechanism of action of this class of sialic acid membrane mimics in attenuating the toxicity of A beta. The mathematical models, when compared with experimental data, facilitate the discrimination between different modes of action of these materials. Understanding the mechanism of action of A beta toxicity inhibitors should provide insight into the design of the next generation of molecules that could be used to prevent A beta toxicity associated with AD.

  1. Lectin staining and Western blot data showing differential sialylation of nutrient-deprived cancer cells to sialic acid supplementation

    Directory of Open Access Journals (Sweden)

    Haitham A. Badr

    2015-12-01

    Full Text Available This report provides data that are specifically related to the differential sialylation of nutrient deprived breast cancer cells to sialic acid supplementation in support of the research article entitled, “Nutrient-deprived cancer cells preferentially use sialic acid to maintain cell surface glycosylation" [1]. Particularly, breast cancer cells, when supplemented with sialic acid under nutrient deprivation, display sialylated glycans at the cell surface, but non-malignant mammary cells show sialylated glycans intracellularly. The impact of sialic acid supplementation under nutrient deprivation was demonstrated by measuring levels of expression and sialylation of two markers, EGFR1 and MUC1. This Data in Brief article complements the main manuscript by providing detailed instructions and representative results for cell-level imaging and Western blot analyses of changes in sialylation during nutrient deprivation and sialic acid supplementation. These methods can be readily generalized for the study of many types of glycosylation and various glycoprotein markers through the appropriate selection of fluorescently-labeled lectins.

  2. Everything Augmented: On the Real in Augmented Reality

    Directory of Open Access Journals (Sweden)

    Hanna Schraffenberger

    2014-12-01

    Full Text Available What is augmented in Augmented Reality (AR? In this paper, we review existing opinions and show how little consensus exists on this matter. Subsequently, we approach the question from a theoretical and technology-independent perspective. We identify spatial and content-based relationships between the virtual and the real as being decisive for AR and come to the conclusion that virtual content augments that to which it relates. Subsequently, we categorize different forms of AR based on what is augmented. We distinguish between augmented environments, augmented objects, augmented humans and augmented content and consider the possibility of augmented perception. The categories are illustrated with AR (art works and conceptual differences between them are pointed out. Moreover, we discuss what the real contributes to AR and how it can shape (future AR experiences. A summary of our findings and suggestions for future research and practice, such as research into multimodal and crossmodal AR, conclude the paper.

  3. Serum Sialic Acid Concentration and Content in ApoB-Containing Lipoproteins in Liver Diseases.

    Science.gov (United States)

    Gudowska, Monika; Gruszewska, Ewa; Cylwik, Bogdan; Panasiuk, Anatol; Filisiak, Robert; Szmitkowski, Maciej; Chrostek, Lech

    2016-01-01

    The great significance for the metabolism of lipoproteins is the composition of carbohydrate chain of apolipoproteins, where sialic acid (SA) is located. In VILDL and LDL sialic acid is attached to apolipoprotein B. The sialylation of serum proteins including apolipoprotein B can be affected in the course of liver diseases. Therefore, the aim of this study was to assess the effect of liver diseases on the concentration and content of SA in ApoB-containing lipoproteins. The tested group consisted of 165 patients (118 males, 47 females) with liver diseases: alcoholic cirrhosis, non-alcoholic cirrhosis, chronic hepatitis, toxic hepatitis, chronic viral hepatitis, and liver cancer. ApoB-containing lipoproteins were isolated by a turbidimetric procedure and SA concentration was measured according to an enzymatic method. There was a significant increase in the serum concentration of SA in ApoB-containing lipoproteins in viral hepatitis. Although the serum concentration of ApoB was not significantly different between specific liver diseases, the serum levels of SA in ApoB-containing lipoproteins appeared to be different. There is an association between SA concentration and triglycerides in alcoholic cirrhosis and viral hepatitis. Also, in viral hepatitis SA concentration correlated negatively with HDL-cholesterol. The content of SA in ApoB-containing lipoproteins in alcoholic cirrhosis and viral hepatitis was significantly higher than that in the control group, but did not differ between diseases. This study may explain the variations in serum lipids and lipoproteins in liver diseases. It seems that the reason for these abnormalities is the changes in the concentration of sialic acid in ApoB-containing lipoproteins.

  4. Effects of altered sialic acid biosynthesis on N-linked glycan branching and cell surface interactions.

    Science.gov (United States)

    Pham, Nam D; Pang, Poh-Choo; Krishnamurthy, Soumya; Wands, Amberlyn M; Grassi, Paola; Dell, Anne; Haslam, Stuart M; Kohler, Jennifer J

    2017-06-09

    GNE (UDP-GlcNAc 2-epimerase/ManNAc kinase) myopathy is a rare muscle disorder associated with aging and is related to sporadic inclusion body myositis, the most common acquired muscle disease of aging. Although the cause of sporadic inclusion body myositis is unknown, GNE myopathy is associated with mutations in GNE. GNE harbors two enzymatic activities required for biosynthesis of sialic acid in mammalian cells. Mutations to both GNE domains are linked to GNE myopathy. However, correlation between mutation-associated reductions in sialic acid production and disease severity is imperfect. To investigate other potential effects of GNE mutations, we compared sialic acid production in cell lines expressing wild type or mutant forms of GNE. Although we did not detect any differences attributable to disease-associated mutations, lectin binding and mass spectrometry analysis revealed that GNE deficiency is associated with unanticipated effects on the structure of cell-surface glycans. In addition to exhibiting low levels of sialylation, GNE-deficient cells produced distinct N-linked glycan structures with increased branching and extended poly-N-acetyllactosamine. GNE deficiency may affect levels of UDP-GlcNAc, a key metabolite in the nutrient-sensing hexosamine biosynthetic pathway, but this modest effect did not fully account for the change in N-linked glycan structure. Furthermore, GNE deficiency and glucose supplementation acted independently and additively to increase N-linked glycan branching. Notably, N-linked glycans produced by GNE-deficient cells displayed enhanced binding to galectin-1, indicating that changes in GNE activity can alter affinity of cell-surface glycoproteins for the galectin lattice. These findings suggest an unanticipated mechanism by which GNE activity might affect signaling through cell-surface receptors. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. The Golgi CMP-sialic acid transporter: A new CHO mutant provides functional insights.

    Science.gov (United States)

    Lim, Sing Fee; Lee, May May; Zhang, Peiqing; Song, Zhiwei

    2008-11-01

    A CHO mutant line, MAR-11, was isolated using a cytotoxic lectin, Maackia amurensis agglutinin (MAA). This mutant has decreased levels of cell surface sialic acid relative to both wild-type CHO-K1 and Lec2 mutant CHO cells. The CMP-sialic acid transporter (CMP-SAT) gene in the MAR-11 mutant cell has a C-T mutation that results in a premature stop codon. As a result, MAR-11 cells express a truncated version of CMP-SAT which contains only 100 amino acids rather than the normal CMP-SAT which contains 336 amino acids. Biochemical analyses indicate that recombinant interferon-gamma (IFN-gamma) produced by the mutant cells lack sialic acid. Using MAR-11 as host cells, an EPO/IEF assay for the structure-function study of CMP-SAT was developed. This assay seems more sensitive than previous assays that were used to analyze sialylation in Lec2 cells. Cotransfection of constructs that express CMP-SAT into MAR-11 cells completely converted the recombinant EPO to a sialylation pattern that is similar to the EPO produced by the wild-type CHO cells. Using this assay, we showed that CMP-SAT lacking C-terminal 18 amino acids from the cytosolic tail was able to allow high levels of EPO sialylation. Substitution of the Gly residues with Ile in three different transmembrane domains of CMP-SAT resulted in dramatic decreases in transporter's activity. The CMP-SAT only lost partial activity if the same Gly residues were substituted with Ala, suggesting that the lack of side chain in Gly residues in the transmembrane domains is essential for transport activity.

  6. Engineering intracellular CMP-sialic acid metabolism into insect cells and methods to enhance its generation.

    Science.gov (United States)

    Viswanathan, Karthik; Narang, Someet; Hinderlich, Stephan; Lee, Yuan C; Betenbaugh, Michael J

    2005-05-24

    Previous studies have reported that insect cell lines lack the capacity to generate endogenously the nucleotide sugar, CMP-Neu5Ac, required for sialylation of glycoconjugates. In this study, the biosynthesis of this activated form of sialic acid completely from endogenous metabolites is demonstrated for the first time in insect cells by expressing the mammalian genes required for the multistep conversion of endogenous UDP-GlcNAc to CMP-Neu5Ac. The genes for UDP-GlcNAc-2-epimerase/ManNAc kinase (EK), sialic acid 9-phosphate synthase (SAS), and CMP-sialic acid synthetase (CSAS) were coexpressed in insect cells using baculovirus expression vectors, but the CMP-Neu5Ac and precursor Neu5Ac levels synthesized were found to be lower than those achieved with ManNAc supplementation due to feedback inhibition of the EK enzyme by CMP-Neu5Ac. When sialuria-like mutant EK genes, in which the site for feedback regulation has been mutated, were used, CMP-Neu5Ac was synthesized at levels more than 4 times higher than that achieved with the wild-type EK and 2.5 times higher than that achieved with ManNAc feeding. Addition of N-acetylglucosamine (GlcNAc), a precursor for UDP-GlcNAc, to the media increased the levels of CMP-Neu5Ac even more to a level 7.5 times higher than that achieved with ManNAc supplementation, creating a bottleneck in the conversion of Neu5Ac to CMP-Neu5Ac at higher levels of UDP-GlcNAc. The present study provides a useful biochemical strategy to synthesize and enhance the levels of the sialylation donor molecule, CMP-Neu5Ac, a critical limiting substrate for the generation of complex glycoproteins in insect cells and other cell culture systems.

  7. Improved workflow for the efficient preparation of ready to use CMP-activated sialic acids.

    Science.gov (United States)

    Gilormini, Pierre-André; Lion, Cédric; Noel, Maxence; Krzewinski-Recchi, Marie-Ange; Harduin-Lepers, Anne; Guérardel, Yann; Biot, Christophe

    2016-11-01

    Natural and synthetically modified cytidine monophosphate activated sialic acids (CMP-Sias) are essential research assets in the field of glycobiology: among other applications, they can be used to probe glycans, detect sialylation defects at the cell surface or carry out detailed studies of sialyltransferase activities. However, these chemical tools are notoriously unstable because of hydrolytic decomposition, and are very time-consuming and costly to obtain. They are nigh impossible to store with satisfactory purity, and their preparation requires multiple laborious purification steps that usually lead to heavy product loss. Using in situ time-resolved 31P phosphorus nuclear magnetic resonance (31P NMR), we precisely established the kinetics of formation and degradation of a number of CMP-Sias including CMP-Neu5Ac, CMP-Neu5Gc, CMP-SiaNAl and CMP-SiaNAz in several experimental conditions. 31P NMR can be carried out in undeuterated solvents and is a sensitive and nondestructive technique that allows for direct in situ monitoring and optimization of chemo-enzymatic syntheses that involve phosphorus-containing species. Thus, we showed that CMP-sialic acid derivatives can be robustly obtained in high yields using the readily available Neisseria meningitidis CMP-sialic acid synthase. This integrated workflow takes less than an hour, and the freshly prepared CMP-Sias can be directly transferred to sialylation biological assays without any purification step. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Characterization of Drosophila CMP-sialic acid synthetase activity reveals unusual enzymatic properties.

    Science.gov (United States)

    Mertsalov, Ilya B; Novikov, Boris N; Scott, Hilary; Dangott, Lawrence; Panin, Vladislav M

    2016-07-01

    CMP-sialic acid synthetase (CSAS) is a key enzyme of the sialylation pathway. CSAS produces the activated sugar donor, CMP-sialic acid, which serves as a substrate for sialyltransferases to modify glycan termini with sialic acid. Unlike other animal CSASs that normally localize in the nucleus, Drosophila melanogaster CSAS (DmCSAS) localizes in the cell secretory compartment, predominantly in the Golgi, which suggests that this enzyme has properties distinct from those of its vertebrate counterparts. To test this hypothesis, we purified recombinant DmCSAS and characterized its activity in vitro Our experiments revealed several unique features of this enzyme. DmCSAS displays specificity for N-acetylneuraminic acid as a substrate, shows preference for lower pH and can function with a broad range of metal cofactors. When tested at a pH corresponding to the Golgi compartment, the enzyme showed significant activity with several metal cations, including Zn(2+), Fe(2+), Co(2+) and Mn(2+), whereas the activity with Mg(2+) was found to be low. Protein sequence analysis and site-specific mutagenesis identified an aspartic acid residue that is necessary for enzymatic activity and predicted to be involved in co-ordinating a metal cofactor. DmCSAS enzymatic activity was found to be essential in vivo for rescuing the phenotype of DmCSAS mutants. Finally, our experiments revealed a steep dependence of the enzymatic activity on temperature. Taken together, our results indicate that DmCSAS underwent evolutionary adaptation to pH and ionic environment different from that of counterpart synthetases in vertebrates. Our data also suggest that environmental temperatures can regulate Drosophila sialylation, thus modulating neural transmission. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  9. Characterisation of Drosophila CMP-sialic acid synthetase activity reveals unusual enzymatic properties

    Science.gov (United States)

    Mertsalov, Ilya B.; Novikov, Boris N.; Scott, Hilary; Dangott, Lawrence; Panin, Vladislav M.

    2016-01-01

    CMP-sialic acid synthetase (CSAS) is a key enzyme of the sialylation pathway. CSAS produces the activated sugar donor, CMP-sialic acid, which serves as a substrate for sialyltransferases to modify glycan termini with sialic acid. Unlike other animal CMP-Sia synthetases that normally localize in the nucleus, Drosophila melanogaster CSAS (DmCSAS) localizes in the cell secretory compartment, predominantly in the Golgi, which suggests that this enzyme has properties distinct from those of its vertebrate counterparts. To test this hypothesis, we purified recombinant DmCSAS and characterised its activity in vitro. Our experiments revealed several unique features of this enzyme. DmCSAS displays specificity for N-acetylneuraminic acid as a substrate, shows preference for lower pH and can function with a broad range of metal cofactors. When tested at a pH corresponding to the Golgi compartment, the enzyme showed significant activity with several metal cations, including Zn2+, Fe2+, Co2+ and Mn2+, while the activity with Mg2+ was found to be low. Protein sequence analysis and site-specific mutagenesis identified an aspartic acid residue that is necessary for enzymatic activity and predicted to be involved in coordinating a metal cofactor. DmCSAS enzymatic activity was found to be essential in vivo for rescuing the phenotype of DmCSAS mutants. Finally, our experiments revealed a steep dependence of the enzymatic activity on temperature. Taken together, our results indicate that DmCSAS underwent evolutionary adaptation to pH and ionic environment different from that of counterpart synthetases in vertebrates. Our data also suggest that environmental temperatures can regulate Drosophila sialylation, thus modulating neural transmission. PMID:27114558

  10. Augmented marked graphs

    CERN Document Server

    Cheung, King Sing

    2014-01-01

    Petri nets are a formal and theoretically rich model for the modelling and analysis of systems. A subclass of Petri nets, augmented marked graphs possess a structure that is especially desirable for the modelling and analysis of systems with concurrent processes and shared resources.This monograph consists of three parts: Part I provides the conceptual background for readers who have no prior knowledge on Petri nets; Part II elaborates the theory of augmented marked graphs; finally, Part III discusses the application to system integration. The book is suitable as a first self-contained volume

  11. Prototyping Augmented Reality

    CERN Document Server

    Mullen, Tony

    2011-01-01

    Learn to create augmented reality apps using Processing open-source programming language Augmented reality (AR) is used all over, and you may not even realize it. Smartphones overlay data onto live camera views to show homes for sale, restaurants, or historical sites. American football broadcasts use AR to show the invisible first-down line on the field to TV viewers. Nike and Budweiser, among others, have used AR in ads. Now, you can learn to create AR prototypes using 3D data, Processing open-source programming language, and other languages. This unique book is an easy-to-follow guide on how

  12. The Augmented Book

    OpenAIRE

    Miller, D

    2015-01-01

    The Augmented Book: Sherwood Rise 30 January 2015 at 14:48 From 2012-13 I carried out practice-based research for the UNESCO future of the book project. The aim was to consider the future of the book using new media technology, particularly Augmented Reality (AR) on mobile phones. My research question was: How could digital media and physical books work together and interact to make a coherent story? I set about making an interactive story where participatory interaction with digital media vi...

  13. Complement Receptor 1 Is a Sialic Acid-Independent Erythrocyte Receptor of Plasmodium falciparum

    Science.gov (United States)

    2010-06-17

    Investigaciones Científicas y Servicios de Alta Tecnología-AIP (INDICASAT- AIP), Ciudad del Saber, Clayton, Panamá, 4 Division of Malaria Vaccine Development, the...erythrocytes (rosetting) [18]. RESULTS Antibodies to CR1 and Soluble CR1 (sCR1) Block Sialic Acid-independent Invasion In order to test the hypothesis...stable inhibition of invasion within a wide range of starting parasitemias (Figure S1). Next, to further test the specificity of our findings and narrow

  14. Characterization of the Adeno-Associated Virus 1 and 6 Sialic Acid Binding Site

    OpenAIRE

    Huang, Lin-Ya; Patel, Ami; Ng, Robert; Miller, Edward Blake; Halder, Sujata; McKenna, Robert; Asokan, Aravind; Agbandje-McKenna, Mavis

    2016-01-01

    The adeno-associated viruses (AAVs), which are being developed as gene delivery vectors, display differential cell surface glycan binding and subsequent tissue tropisms. For AAV serotype 1 (AAV1), the first viral vector approved as a gene therapy treatment, and its closely related AAV6, sialic acid (SIA) serves as their primary cellular surface receptor. Toward characterizing the SIA binding site(s), the structure of the AAV1-SIA complex was determined by X-ray crystallography to 3.0 Å. Densi...

  15. 3DSDSCAR--a three dimensional structural database for sialic acid-containing carbohydrates through molecular dynamics simulation.

    Science.gov (United States)

    Veluraja, Kasinadar; Selvin, Jeyasigamani F A; Venkateshwari, Selvakumar; Priyadarzini, Thanu R K

    2010-09-23

    The inherent flexibility and lack of strong intramolecular interactions of oligosaccharides demand the use of theoretical methods for their structural elucidation. In spite of the developments of theoretical methods, not much research on glycoinformatics is done so far when compared to bioinformatics research on proteins and nucleic acids. We have developed three dimensional structural database for a sialic acid-containing carbohydrates (3DSDSCAR). This is an open-access database that provides 3D structural models of a given sialic acid-containing carbohydrate. At present, 3DSDSCAR contains 60 conformational models, belonging to 14 different sialic acid-containing carbohydrates, deduced through 10 ns molecular dynamics (MD) simulations. The database is available at the URL: http://www.3dsdscar.org. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Infection with human H1N1 influenza virus affects the expression of sialic acids of metaplastic mucous cells in the ferret airways

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Martel, Cyril Jean-Marie; Aasted, Bent

    2009-01-01

    Glycans terminating in sialic acids serve as receptors for influenza viruses. In this study ferrets were infected with influenza virus A/New Caledonia/20/99, and the in situ localization of sialic acids linked a2-3 and a2-6 in the airways was investigated in infected and non-infected animals by u...

  17. Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality.

    Science.gov (United States)

    Grubert, Jens; Langlotz, Tobias; Zollmann, Stefanie; Regenbrecht, Holger

    2017-06-01

    Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

  18. Augmented Reality Binoculars.

    Science.gov (United States)

    Oskiper, Taragay; Sizintsev, Mikhail; Branzoi, Vlad; Samarasekera, Supun; Kumar, Rakesh

    2015-05-01

    In this paper we present an augmented reality binocular system to allow long range high precision augmentation of live telescopic imagery with aerial and terrain based synthetic objects, vehicles, people and effects. The inserted objects must appear stable in the display and must not jitter and drift as the user pans around and examines the scene with the binoculars. The design of the system is based on using two different cameras with wide field of view and narrow field of view lenses enclosed in a binocular shaped shell. Using the wide field of view gives us context and enables us to recover the 3D location and orientation of the binoculars much more robustly, whereas the narrow field of view is used for the actual augmentation as well as to increase precision in tracking. We present our navigation algorithm that uses the two cameras in combination with an inertial measurement unit and global positioning system in an extended Kalman filter and provides jitter free, robust and real-time pose estimation for precise augmentation. We have demonstrated successful use of our system as part of information sharing example as well as a live simulated training system for observer training, in which fixed and rotary wing aircrafts, ground vehicles, and weapon effects are combined with real world scenes.

  19. Collaboration in Augmented Reality

    NARCIS (Netherlands)

    Lukosch, S.; Billinghurst, M.; Alem, L.; Kiyokawa, K.

    2015-01-01

    Augmented Reality (AR) is a technology that allows users to view and interact in real time with virtual images seamlessly superimposed over the real world. AR systems can be used to create unique collaborative experiences. For example, co-located users can see shared 3D virtual objects that they

  20. Augmented reality som wearable

    DEFF Research Database (Denmark)

    Buhl, Mie; Rahn, Annette

    2015-01-01

    Artiklen omhandler design og implementering af Augmented Reality (AR) i form af en wearable i sygeplejerskeuddannelsens anatomiundervisning, mere specifikt undervisning i lungeanatomi og respiration, med fokus på potentialer for visuel læring. Projektet undersøger, hvordan en udviklet AR...

  1. Augmented Reality og kulturarv

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Kirkedahl Lysholm

    2013-01-01

    Museerne står overfor at skulle omfavne den digitale kultur i håndteringen af den store mængde viden, institutionerne repræsenterer. Augmented Reality-systemer forbinder ved hjælp af moderne teknologi det virtuelle med det virkelige, og kan derfor synes som en oplagt anvendelsesmulighed i...

  2. Augmented Reality i naturfagsundervisningen

    DEFF Research Database (Denmark)

    Radmer, Ole; Surland, Mogens; Nielsen, Birgitte Lund

    Augmented Reality (AR) giver ny mulighed for, at elever kan lave undersøgelser i naturfag med enkel teknologi, hvor animationer og simulationer kobles med det virkelige fænomen. I workshoppen kan I afprøve AR eksempler, udviklet i et internationalt EU projekt. Der vil være noget, der direkte kan...

  3. Sialic Acid-Responsive Polymeric Interface Material: From Molecular Recognition to Macroscopic Property Switching

    Science.gov (United States)

    Xiong, Yuting; Jiang, Ge; Li, Minmin; Qing, Guangyan; Li, Xiuling; Liang, Xinmiao; Sun, Taolei

    2017-01-01

    Biological systems that utilize multiple weak non-covalent interactions and hierarchical assemblies to achieve various bio-functions bring much inspiration for the design of artificial biomaterials. However, it remains a big challenge to correlate underlying biomolecule interactions with macroscopic level of materials, for example, recognizing such weak interaction, further transforming it into regulating material’s macroscopic property and contributing to some new bio-applications. Here we designed a novel smart polymer based on polyacrylamide (PAM) grafted with lactose units (PAM-g-lactose0.11), and reported carbohydrate-carbohydrate interaction (CCI)-promoted macroscopic properties switching on this smart polymer surface. Detailed investigations indicated that the binding of sialic acid molecules with the grafted lactose units via the CCIs induced conformational transformation of the polymer chains, further resulted in remarkable and reversible switching in surface topography, wettability and stiffness. With these excellent recognition and response capacities towards sialic acid, the PAM-g-lactose0.11 further facilitated good selectivity, strong anti-interference and high adsorption capacity in the capture of sialylated glycopeptides (important biomarkers for cancers). This work provides some enlightenment for the development of biointerface materials with tunable property, as well as high-performance glycopeptide enrichment materials.

  4. Sialic Acid within the Glycosylphosphatidylinositol Anchor Targets the Cellular Prion Protein to Synapses*

    Science.gov (United States)

    Bate, Clive; Nolan, William; McHale-Owen, Harriet; Williams, Alun

    2016-01-01

    Although the cellular prion protein (PrPC) is concentrated at synapses, the factors that target PrPC to synapses are not understood. Here we demonstrate that exogenous PrPC was rapidly targeted to synapses in recipient neurons derived from Prnp knock-out(0/0) mice. The targeting of PrPC to synapses was dependent upon both neuronal cholesterol concentrations and the lipid and glycan composition of its glycosylphosphatidylinositol (GPI) anchor. Thus, the removal of either an acyl chain or sialic acid from the GPI anchor reduced the targeting of PrPC to synapses. Isolated GPIs (derived from PrPC) were also targeted to synapses, as was IgG conjugated to these GPIs. The removal of sialic acid from GPIs prevented the targeting of either the isolated GPIs or the IgG-GPI conjugate to synapses. Competition studies showed that pretreatment with sialylated GPIs prevented the targeting of PrPC to synapses. These results are consistent with the hypothesis that the sialylated GPI anchor attached to PrPC acts as a synapse homing signal. PMID:27325697

  5. Sialic Acid within the Glycosylphosphatidylinositol Anchor Targets the Cellular Prion Protein to Synapses.

    Science.gov (United States)

    Bate, Clive; Nolan, William; McHale-Owen, Harriet; Williams, Alun

    2016-08-12

    Although the cellular prion protein (PrP(C)) is concentrated at synapses, the factors that target PrP(C) to synapses are not understood. Here we demonstrate that exogenous PrP(C) was rapidly targeted to synapses in recipient neurons derived from Prnp knock-out((0/0)) mice. The targeting of PrP(C) to synapses was dependent upon both neuronal cholesterol concentrations and the lipid and glycan composition of its glycosylphosphatidylinositol (GPI) anchor. Thus, the removal of either an acyl chain or sialic acid from the GPI anchor reduced the targeting of PrP(C) to synapses. Isolated GPIs (derived from PrP(C)) were also targeted to synapses, as was IgG conjugated to these GPIs. The removal of sialic acid from GPIs prevented the targeting of either the isolated GPIs or the IgG-GPI conjugate to synapses. Competition studies showed that pretreatment with sialylated GPIs prevented the targeting of PrP(C) to synapses. These results are consistent with the hypothesis that the sialylated GPI anchor attached to PrP(C) acts as a synapse homing signal. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Complementing the sugar code: role of GAGs and sialic acid in complement regulation

    Directory of Open Access Journals (Sweden)

    Alex eLangford-Smith

    2015-02-01

    Full Text Available Sugar molecules play a vital role on both microbial and mammalian cells, where they are involved in cellular communication, govern microbial virulence and modulate host immunity and inflammatory responses. The complement cascade, as part of a host’s innate immune system, is a potent weapon against invading bacteria but has to be tightly regulated to prevent inappropriate attack and damage to host tissues. A number of complement regulators, such as factor H and properdin, interact with sugar molecules, such as glycosaminoglycans and sialic acid, on host and pathogen membranes and direct the appropriate complement response by either promoting the binding of complement activators or inhibitors. The binding of these complement regulators to sugar molecules can vary from location to location, due to their different specificities and because distinct structural and functional subpopulations of sugars are found in different human organs, such as the brain, kidney and eye. This review will cover recent studies that have provided important new insights into the role of glycosaminoglycans and sialic acid in complement regulation and how sugar recognition may be compromised in disease

  7. Physiological significance of Fuc and Sialic acid containing glycans in the body

    Directory of Open Access Journals (Sweden)

    Muhammad Ramzan Manwar Hussain

    2016-09-01

    Full Text Available Complex biomolecular machinery carrying diverse glycan chains are involved in a wide range of physiological activities including blood group determination, cancer recognition protein stabilization and sperm–egg interaction. Diversity of glycan chains, linked to lipids and proteins is due to isomeric and conformational modifications of various sugar residues, giving rise to unique carbohydrate structures with a wide range of anomeric linkages. This unique and significant structural diversity of naturally occurring oligosaccharide structures make them the best recognition markers for countless physiological activities. This is a challenging task to explore the relationship between biological processes and stereochemical behavior of sugar residues. Current review article is related with the physiological significance of glycans carrying fucose and/or sialic residues in complex biomolecular assemblies. Both the sugar units have a diverse range of anomery and linkages with the penultimate sugars. The existing literature and databases did not contain comprehensive information regarding structure–function relationship of glycans. Therefore, the current study is scheduled to debate on the structure–function relationship of glycans carrying Fuc and sialic acid in their backbone structures.

  8. Synthesis of Sulfo-Sialic Acid Analogues: Potent Neuraminidase Inhibitors in Regards to Anomeric Functionality.

    Science.gov (United States)

    Vavricka, Christopher J; Muto, Chiaki; Hasunuma, Tomohisa; Kimura, Yoshinobu; Araki, Michihiro; Wu, Yan; Gao, George F; Ohrui, Hiroshi; Izumi, Minoru; Kiyota, Hiromasa

    2017-08-15

    The design, synthesis and application of N-acetylneuraminic acid-derived compounds bearing anomeric sulfo functional groups are described. These novel compounds, which we refer to as sulfo-sialic acid analogues, include 2-decarboxy-2-deoxy-2-sulfo-N-acetylneuraminic acid and its 4-deoxy-3,4-dehydrogenated pseudoglycal. While 2-decarboxy-2-deoxy-2-sulfo-N-acetylneuraminic acid contains no further modifications of the 2-deoxy-pyranose ring, it is still a more potent inhibitor of avian-origin H5N1 neuraminidase (NA) and drug-resistant His275Tyr NA as compared to the oxocarbenium ion transition state analogue 2,3-dehydro-2-deoxy-N-acetylneuraminic acid. The sulfo-sialic acid analogues described in this report are also more potent inhibitors of influenza NA (up to 40-fold) and bacterial NA (up to 8.5-fold) relative to the corresponding anomeric phosphonic acids. These results confirm that this novel anomeric sulfo modification offers great potential to improve the potency of next-generation NA inhibitors including covalent inhibitors.

  9. Sialic acids and antimicrobial substances in the apocrine glands of porcine perianal skin.

    Science.gov (United States)

    Nara, Takayuki; Yasui, Tadashi; Fujimori, Osamu; Meyer, Wilfried; Tsukise, Azuma

    2012-10-01

    The porcine perianal skin shows prominent apocrine glands with large saccular dilatations, whereby the functional significance of the glandular secretions is rather unexplained. Our study focuses on the demonstration of sialoglycoconjugates and antimicrobial substances in these glands, using glycoconjugate histochemical and immunohistochemical methods. The result obtained emphasized the general presence of sialic acids, linked to α2-6Gal/GalNAc and α2-3Gaβl1-4GlcNAc, in the secretory cells. The secretory epithelium and luminal secretions also contained a spectrum of antimicrobial substances, such as lysozyme, IgA, lactoferrin, and the peptide group of β-defensins. Realizing that sialic acids possess diverging functional properties through various saccharide residues, and that antimicrobial substances serve as a non-specific defense against microorganisms, these secretory products may function as protective agents in order to preserve the integrity of the perianal region. This view includes that the amounts of bacteria on the skin surface are controlled and maintained at the certain level.

  10. AR DOC: Augmented reality documentaries

    DEFF Research Database (Denmark)

    Vistisen, Peter

    2014-01-01

    Augmented Reality Documentaries (AR DOC) er et ’lille’ Shareplay projekt (ansøgte midler augmented reality cross media løsninger, til at skabe engagerende publikumsformidling...... indenfor oplevelsesindustrien. Projektet har genereret ny viden omkring, hvordan fysisk og digital formidling kan understøttes via Augmented Reality som formidlingsformat....

  11. Augmenting Clozapine With Sertindole

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Emborg, Charlotte; Gydesen, Susanne

    2012-01-01

    . The study design was a 12-week, double-blind, randomized, placebo-controlled study including patients with International Statistical Classification of Diseases, 10th Revision schizophrenia (F20.0-F20.3) and treated with clozapine for at least 6 months who had not achieved sufficient response. Patients were...... Inventory, fasting glucose, lipids, and electrocardiogram. Clozapine augmentation with sertindole was not superior to placebo regarding total score or subscale score of the Positive and Negative Syndrome Scale, Clinical Global Impression, World Health Organization Quality of Life Brief, or Drug Attitude...... Inventory. No increased adverse effects compared with placebo were found. Four patients randomized to sertindole experienced a significant worsening of psychosis, and 2 of them required psychiatric admission. Metabolic parameters were unchanged during the study, but augmentation of clozapine with sertindole...

  12. Transaxillary Endoscopic Breast Augmentation

    Directory of Open Access Journals (Sweden)

    Hyung-Bo Sim

    2014-09-01

    Full Text Available The axillary technique is the most popular approach to breast augmentation among Korean women. Transaxillary breast augmentation is now conducted with sharp electrocautery dissection under direct endoscopic vision throughout the entire process. The aims of this method are clear: both a bloodless pocket and a sharp non-traumatic dissection. Round textured or anatomical cohesive gel implants have been used to make predictable well-defined inframammary creases because textured surface implants demonstrated a better stability attributable to tissue adherence compared with smooth surface implants. The axillary endoscopic technique has greatly evolved, and now the surgical results are comparable to those with the inframammary approach. The author feels that this technique is an excellent choice for young patients with an indistinct or absent inframammary fold, who do not want a scar in the aesthetic unit of their chest.

  13. Sialic acid mediated transcriptional modulation of a highly conserved sialometabolism gene cluster in Haemophilus influenzae and its effect on virulence

    Directory of Open Access Journals (Sweden)

    Moxon Richard

    2010-02-01

    Full Text Available Abstract Background Sialic acid has been shown to be a major virulence determinant in the pathogenesis of otitis media caused by the bacterium Haemophilus influenzae. This study aimed to characterise the expression of genes required for the metabolism of sialic acid and to investigate the role of these genes in virulence. Results Using qRT-PCR, we observed decreased transcriptional activity of genes within a cluster that are required for uptake and catabolism of 5-acetyl neuraminic acid (Neu5Ac, when bacteria were cultured in the presence of the sugar. We show that these uptake and catabolic genes, including a sialic acid regulatory gene (siaR, are highly conserved in the H. influenzae natural population. Mutant strains were constructed for seven of the nine genes and their influence upon LPS sialylation and resistance of the bacteria to the killing effect of normal human serum were assessed. Mutations in the Neu5Ac uptake (TRAP transporter genes decreased virulence in the chinchilla model of otitis media, but the attenuation was strain dependent. In contrast, mutations in catabolism genes and genes regulating sialic acid metabolism (siaR and crp did not attenuate virulence. Conclusion The commensal and pathogenic behaviour of H. influenzae involves LPS sialylation that can be influenced by a complex regulatory interplay of sialometabolism genes.

  14. Intestinal neuraminidase activity of suckling rats and other mammals. Relationship to the sialic acid content of milk.

    Science.gov (United States)

    Dickson, J J; Messer, M

    1978-02-15

    1. The neuraminidase activity of homogenates of the mucosa of the middle and distal thirds of the small intestine of rats increased about 5-fold between birth and 4 to 8 days of age, and then gradually declined to the much lower adult activity by 24 days. No comparable changes occurred in the proximal third. 2. In 8-day-old rats, the neuraminidase activity of the middle and distal thirds of the small intestine was about 10 times greater than that of the proximal third, 20 times greater than that of the colon and at least 100 times greater than that of the liver, brain, gastric mucosa or pancreas. 3. In all other species investigated (mice, rabbits, cats and guinea pigs), the neuraminidase activity of the middle and distal thirds of the small intestine was greater in suckling animals than in adults. 4. The sialic acid content of rat milk increased about 2-fold between birth and 8 days post partum and then declined. 5. There was a highly significant positive correlation between the intestinal neuraminidase activity of suckling animals of various species and ages and the sialic acid content of milk obtained from the corresponding species and stage of lactation. 6. It is suggested that the intestinal neuraminidase of suckling mammals functions primarily to remove sialic acid from various components of milk, thus providing sialic acid for the synthesis of sialoglycoproteins and gangliosides by the young.

  15. Contribution of Sialic Acid-Binding Adhesin to Pathogenesis of Experimental Endocarditis Caused by Streptococcus gordonii DL1

    Science.gov (United States)

    Takahashi, Yukihiro; Takashima, Eizo; Shimazu, Kisaki; Yagishita, Hisao; Aoba, Takaaki; Konishi, Kiyoshi

    2006-01-01

    An insertional mutation in hsa, the gene encoding the sialic acid-binding adhesin of Streptococcus gordonii DL1, resulted in a significant reduction of the infection rate of the organism and an inflammatory reaction in the rat aortic valve with experimental endocarditis, suggesting that the adhesin contributes to the infectivity of the organism for heart valves. PMID:16369032

  16. Sialic acid on the neuronal glycocalyx prevents complement C1 binding and complement receptor-3-mediated removal by microglia.

    Science.gov (United States)

    Linnartz, Bettina; Kopatz, Jens; Tenner, Andrea J; Neumann, Harald

    2012-01-18

    Microglial cells are professional phagocytes of the CNS responsible for clearance of unwanted structures. Neuronal processes are marked by complement C1 before they are removed in development or during disease processes. Target molecules involved in C1 binding and mechanisms of clearance are still unclear. Here we show that the terminal sugar residue sialic acid of the mouse neuronal glycocalyx determines complement C1 binding and microglial-mediated clearance function. Several early components of the classical complement cascade including C1q, C1r, C1s, and C3 were produced by cultured mouse microglia. The opsonin C1q was binding to neurites after enzymatic removal of sialic acid residues from the neuronal glycocalyx. Desialylated neurites, but not neurites with intact sialic acid caps, were cleared and taken up by cocultured microglial cells. The removal of the desialylated neurites was mediated via the complement receptor-3 (CR3; CD11b/CD18). Data demonstrate that mouse microglial cells via CR3 recognize and remove neuronal structures with an altered neuronal glycocalyx lacking terminal sialic acid.

  17. Impact of a human CMP-sialic acid transporter on recombinant glycoprotein sialylation in glycoengineered insect cells.

    Science.gov (United States)

    Mabashi-Asazuma, Hideaki; Shi, Xianzong; Geisler, Christoph; Kuo, Chu-Wei; Khoo, Kay-Hooi; Jarvis, Donald L

    2013-02-01

    Insect cells are widely used for recombinant glycoprotein production, but they cannot provide the glycosylation patterns required for some biotechnological applications. This problem has been addressed by genetically engineering insect cells to express mammalian genes encoding various glycoprotein glycan processing functions. However, for various reasons, the impact of a mammalian cytosine-5'-monophospho (CMP)-sialic acid transporter has not yet been examined. Thus, we transformed Spodoptera frugiperda (Sf9) cells with six mammalian genes to generate a new cell line, SfSWT-4, that can produce sialylated glycoproteins when cultured with the sialic acid precursor, N-acetylmannosamine. We then super-transformed SfSWT-4 with a human CMP-sialic acid transporter (hCSAT) gene to isolate a daughter cell line, SfSWT-6, which expressed the hCSAT gene in addition to the other mammalian glycogenes. SfSWT-6 cells had higher levels of cell surface sialylation and also supported higher levels of recombinant glycoprotein sialylation, particularly when cultured with low concentrations of N-acetylmannosamine. Thus, hCSAT expression has an impact on glycoprotein sialylation, can reduce the cost of recombinant glycoprotein production and therefore should be included in ongoing efforts to glycoengineer the baculovirus-insect cell system. The results of this study also contributed new insights into the endogenous mechanism and potential mechanisms of CMP-sialic acid accumulation in the Golgi apparatus of lepidopteran insect cells.

  18. Augmented reality services

    Directory of Open Access Journals (Sweden)

    Tomáš Koubek

    2013-01-01

    Full Text Available We assume that one of the key reasons is in the difference between a standalone application and a web service. Both architectures have some advantages and disadvantages. The Standalone application (e.g. Nokia/OVI Maps provides the required functionality. From the user point of view, main asset of this “offline” approach is network connectivity independence. However, this kind of applications must be upgraded manually. Moreover, it is hard to get any data about the application usage because it requires additional actions from the user – data are usually acquired through conventional ways, such as email or web forms.The online service such as Google Maps (including its mobile application can offer the same functionality as the offline application. Nevertheless, a permanent connection to provider servers is necessary. This can be taken as a drawback. On the other hand, usage data collection is easier and can be done without the user intervention. The data collection provides a valuable analysis basis of the user habits and needs. This analysis is necessary for design of a complex “user” based solutions such as Google Now.Augmented reality applications are usually based on the first mentioned approach. In this article, we describe our model of augmented reality as a service and compare its features with standalone solutions. Further, other important key aspects for large emergence of augmented reality services in a mainstream market are discussed.

  19. Amino acid residues important for CMP-sialic acid recognition by the CMP-sialic acid transporter: analysis of the substrate specificity of UDP-galactose/CMP-sialic acid transporter chimeras.

    Science.gov (United States)

    Takeshima-Futagami, Taro; Sakaguchi, Masayoshi; Uehara, Eriko; Aoki, Kazuhisa; Ishida, Nobuhiro; Sanai, Yutaka; Sugahara, Yasusato; Kawakita, Masao

    2012-12-01

    In our previous studies, we demonstrated that chimeric molecules of the CMP-sialic acid (CMP-Sia) transporter (CST) and the UDP-galactose (Gal) transporter (UGT) in which the seventh transmembrane helix-containing segment was derived from the CST could transport both CMP-Sia and UDP-Gal and that the CST-derived seventh transmembrane helix segment was sufficient for the chimera to recognize CMP-Sia in the otherwise UGT context. In this study, we continued to more precisely define the submolecular region that is necessary for CMP-Sia recognition, and we demonstrated that the N-terminal half of the seventh transmembrane helix of CST is essential for the CMP-Sia transport mediated by the chimeric transporters. We further showed that Tyr214Gly and Ser216Phe mutations of a chimeric transporter that was capable of transporting both CMP-Sia and UDP-Gal led to the selective loss of CMP-Sia transport activity without affecting UDP-Gal transport activity. Conversely, when a residue in a chimeric transporter that was active for UDP-Gal transport but not CMP-Sia transport was replaced by Tyr, so that Tyr occupied the same position as in the CMP-Sia transporter, the resulting mutant chimera acquired the ability to transport CMP-Sia. These results demonstrated that Tyr214 and Ser216, located in the seventh transmembrane helix of the human CST, are critically important for the recognition of CMP-Sia as a transport substrate. Identification of determinants critical for the discrimination between relevant and irrelevant substrates will advance our understanding of the mechanisms of substrate recognition by nucleotide sugar transporters.

  20. Myelin-associated glycoprotein interacts with neurons via a sialic acid binding site at ARG118 and a distinct neurite inhibition site.

    Science.gov (United States)

    Tang, S; Shen, Y J; DeBellard, M E; Mukhopadhyay, G; Salzer, J L; Crocker, P R; Filbin, M T

    1997-09-22

    Inhibitory components in myelin are largely responsible for the lack of regeneration in the mammalian CNS. Myelin-associated glycoprotein (MAG), a sialic acid binding protein and a component of myelin, is a potent inhibitor of neurite outgrowth from a variety of neurons both in vitro and in vivo. Here, we show that MAG's sialic acid binding site is distinct from its neurite inhibitory activity. Alone, sialic acid-dependent binding of MAG to neurons is insufficient to effect inhibition of axonal growth. Thus, while soluble MAG-Fc (MAG extracellular domain fused to Fc), a truncated form of MAG-Fc missing Ig-domains 4 and 5, MAG(d1-3)-Fc, and another sialic acid binding protein, sialoadhesin, each bind to neurons in a sialic acid- dependent manner, only full-length MAG-Fc inhibits neurite outgrowth. These results suggest that a second site must exist on MAG which elicits this response. Consistent with this model, mutation of arginine 118 (R118) in MAG to either alanine or aspartate abolishes its sialic acid-dependent binding. However, when expressed at the surface of either CHO or Schwann cells, R118-mutated MAG retains the ability to inhibit axonal outgrowth. Hence, MAG has two recognition sites for neurons, the sialic acid binding site at R118 and a distinct inhibition site which is absent from the first three Ig domains.

  1. Myelin-associated Glycoprotein Interacts with Neurons via a Sialic Acid Binding Site at ARG118 and a Distinct Neurite Inhibition Site

    Science.gov (United States)

    Tang, Song; Shen, Ying Jing; DeBellard, Maria Elena; Mukhopadhyay, Gitali; Salzer, James L.; Crocker, Paul R.; Filbin, Marie T.

    1997-01-01

    Inhibitory components in myelin are largely responsible for the lack of regeneration in the mammalian CNS. Myelin-associated glycoprotein (MAG), a sialic acid binding protein and a component of myelin, is a potent inhibitor of neurite outgrowth from a variety of neurons both in vitro and in vivo. Here, we show that MAG's sialic acid binding site is distinct from its neurite inhibitory activity. Alone, sialic acid–dependent binding of MAG to neurons is insufficient to effect inhibition of axonal growth. Thus, while soluble MAG-Fc (MAG extracellular domain fused to Fc), a truncated form of MAG-Fc missing Ig-domains 4 and 5, MAG(d1-3)-Fc, and another sialic acid binding protein, sialoadhesin, each bind to neurons in a sialic acid– dependent manner, only full-length MAG-Fc inhibits neurite outgrowth. These results suggest that a second site must exist on MAG which elicits this response. Consistent with this model, mutation of arginine 118 (R118) in MAG to either alanine or aspartate abolishes its sialic acid–dependent binding. However, when expressed at the surface of either CHO or Schwann cells, R118-mutated MAG retains the ability to inhibit axonal outgrowth. Hence, MAG has two recognition sites for neurons, the sialic acid binding site at R118 and a distinct inhibition site which is absent from the first three Ig domains. PMID:9298990

  2. A novel approach to decrease sialic acid expression in cells by a C-3-modified N-acetylmannosamine.

    Science.gov (United States)

    Wratil, Paul R; Rigol, Stephan; Solecka, Barbara; Kohla, Guido; Kannicht, Christoph; Reutter, Werner; Giannis, Athanassios; Nguyen, Long D

    2014-11-14

    Due to its position at the outermost of glycans, sialic acid is involved in a myriad of physiological and pathophysiological cell functions such as host-pathogen interactions, immune regulation, and tumor evasion. Inhibitors of cell surface sialylation could be a useful tool in cancer, immune, antibiotic, or antiviral therapy. In this work, four different C-3 modified N-acetylmannosamine analogs were tested as potential inhibitors of cell surface sialylation. Peracetylated 2-acetylamino-2-deoxy-3-O-methyl-D-mannose decreases cell surface sialylation in Jurkat cells in a dose-dependent manner up to 80%, quantified by flow cytometry and enzyme-linked lectin assays. High-performance liquid chromatography experiments revealed that not only the concentration of membrane bound but also of cytosolic sialic acid is reduced in treated cells. We have strong evidence that the observed reduction of sialic acid expression in cells is caused by the inhibition of the bifunctional enzyme UDP-GlcNAc-2-epimerase/ManNAc kinase. 2-Acetylamino-2-deoxy-3-O-methyl-D-mannose inhibits the human ManNAc kinase domain of the UDP-GlcNAc-2-epimerase/ManNAc kinase. Binding kinetics of the inhibitor and human N-acetylmannosamine kinase were evaluated using surface plasmon resonance. Specificity studies with human N-acetylglucosamine kinase and hexokinase IV indicated a high specificity of 2-acetylamino-2-deoxy-3-O-methyl-D-mannose for MNK. This substance represents a novel class of inhibitors of sialic acid expression in cells, targeting the key enzyme of sialic acid de novo biosynthesis. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. A Novel Approach to Decrease Sialic Acid Expression in Cells by a C-3-modified N-Acetylmannosamine*

    Science.gov (United States)

    Wratil, Paul R.; Rigol, Stephan; Solecka, Barbara; Kohla, Guido; Kannicht, Christoph; Reutter, Werner; Giannis, Athanassios; Nguyen, Long D.

    2014-01-01

    Due to its position at the outermost of glycans, sialic acid is involved in a myriad of physiological and pathophysiological cell functions such as host-pathogen interactions, immune regulation, and tumor evasion. Inhibitors of cell surface sialylation could be a useful tool in cancer, immune, antibiotic, or antiviral therapy. In this work, four different C-3 modified N-acetylmannosamine analogs were tested as potential inhibitors of cell surface sialylation. Peracetylated 2-acetylamino-2-deoxy-3-O-methyl-d-mannose decreases cell surface sialylation in Jurkat cells in a dose-dependent manner up to 80%, quantified by flow cytometry and enzyme-linked lectin assays. High-performance liquid chromatography experiments revealed that not only the concentration of membrane bound but also of cytosolic sialic acid is reduced in treated cells. We have strong evidence that the observed reduction of sialic acid expression in cells is caused by the inhibition of the bifunctional enzyme UDP-GlcNAc-2-epimerase/ManNAc kinase. 2-Acetylamino-2-deoxy-3-O-methyl-d-mannose inhibits the human ManNAc kinase domain of the UDP-GlcNAc-2-epimerase/ManNAc kinase. Binding kinetics of the inhibitor and human N-acetylmannosamine kinase were evaluated using surface plasmon resonance. Specificity studies with human N-acetylglucosamine kinase and hexokinase IV indicated a high specificity of 2-acetylamino-2-deoxy-3-O-methyl-d-mannose for MNK. This substance represents a novel class of inhibitors of sialic acid expression in cells, targeting the key enzyme of sialic acid de novo biosynthesis. PMID:25278018

  4. Rapid regulation of sialidase activity in response to neural activity and sialic acid removal during memory processing in rat hippocampus.

    Science.gov (United States)

    Minami, Akira; Meguro, Yuko; Ishibashi, Sayaka; Ishii, Ami; Shiratori, Mako; Sai, Saki; Horii, Yuuki; Shimizu, Hirotaka; Fukumoto, Hokuto; Shimba, Sumika; Taguchi, Risa; Takahashi, Tadanobu; Otsubo, Tadamune; Ikeda, Kiyoshi; Suzuki, Takashi

    2017-04-07

    Sialidase cleaves sialic acids on the extracellular cell surface as well as inside the cell and is necessary for normal long-term potentiation (LTP) at mossy fiber-CA3 pyramidal cell synapses and for hippocampus-dependent spatial memory. Here, we investigated in detail the role of sialidase in memory processing. Sialidase activity measured with 4-methylumbelliferyl-α-d-N-acetylneuraminic acid (4MU-Neu5Ac) or 5-bromo-4-chloroindol-3-yl-α-d-N-acetylneuraminic acid (X-Neu5Ac) and Fast Red Violet LB was increased by high-K+-induced membrane depolarization. Sialidase activity was also increased by chemical LTP induction with forskolin and activation of BDNF signaling, non-NMDA receptors, or NMDA receptors. The increase in sialidase activity with neural excitation appears to be caused not by secreted sialidase or by an increase in sialidase expression but by a change in the subcellular localization of sialidase. Astrocytes as well as neurons are also involved in the neural activity-dependent increase in sialidase activity. Sialidase activity visualized with a benzothiazolylphenol-based sialic acid derivative (BTP3-Neu5Ac), a highly sensitive histochemical imaging probe for sialidase activity, at the CA3 stratum lucidum of rat acute hippocampal slices was immediately increased in response to LTP-inducible high-frequency stimulation on a time scale of seconds. To obtain direct evidence for sialic acid removal on the extracellular cell surface during neural excitation, the extracellular free sialic acid level in the hippocampus was monitored using in vivo microdialysis. The free sialic acid level was increased by high-K+-induced membrane depolarization. Desialylation also occurred during hippocampus-dependent memory formation in a contextual fear-conditioning paradigm. Our results show that neural activity-dependent desialylation by sialidase may be involved in hippocampal memory processing. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Analyses of N-linked glycans of PrPSc revealed predominantly 2,6-linked sialic acid residues.

    Science.gov (United States)

    Katorcha, Elizaveta; Baskakov, Ilia V

    2017-11-01

    Mammalian prions (PrPSc ) consist of misfolded, conformationally altered, self-replicating states of the sialoglycoprotein called prion protein or PrPC . Recent studies revealed that the sialylation status of PrPSc plays a major role in evading innate immunity and infecting a host. Establishing the type of linkage by which sialic acid residues are attached to galactose is important, as it helps to identify the sialyltransferases responsible for sialylating PrPC and outline strategies for manipulating the sialyation status of PrPSc . Using enzymatic treatment with sialidases and lectin blots, this study demonstrated that in N-linked glycans of PrPSc , the sialic acid residues are predominantly alpha 2,6-linked. High percentages of alpha 2,6-linked sialic acids were observed in PrPSc of three prion strains 22L, RML, and ME7, as well as PrPSc from brain, spleen, or N2a cells cultured in vitro. Moreover, the variation in the percentage of alpha 2,3- versus 2,6-linked sialic acid was found to be relatively minor between brain-, spleen-, or cell-derived PrPSc , suggesting that the type of linkage is independent of tissue type. Based on the current results, we propose that sialyltransferases of St6Gal family, which is responsible for attaching sialic acids via alpha 2,6-linkages to N-linked glycans, controls sialylation of PrPC and PrPSc . © 2017 Federation of European Biochemical Societies.

  6. Development of magnetic resonance imaging based detection methods for beta amyloids via sialic acid-functionalized magnetic nanoparticles

    Science.gov (United States)

    Kouyoumdjian, Hovig

    The development of a non-invasive method for the detection of Alzheimer's disease is of high current interest, which can be critical in early diagnosis and in guiding preventive treatment of the disease. The aggregates of beta amyloids are a pathological hallmark of Alzheimer's disease. Carbohydrates such as sialic acid terminated gangliosides have been shown to play significant roles in initiation of amyloid aggregation. Herein, we report a biomimetic approach using sialic acid coated iron oxide superparamagnetic nanoparticles for in vitro detection in addition to the assessment of the in vivo mouse-BBB (Blood brain barrier) crossing of the BSA (bovine serum albumin)-modified ones. The sialic acid functionalized dextran nanoparticles were shown to bind with beta amyloids through several techniques including ELISA (enzyme linked immunosorbent assay), MRI (magnetic resonance imaging), TEM (transmission electron microscopy), gel electrophoresis and tyrosine fluorescence assay. The superparamagnetic nature of the nanoparticles allowed easy detection of the beta amyloids in mouse brains in both in vitro and ex vivo model by magnetic resonance imaging. Furthermore, the sialic acid nanoparticles greatly reduced beta amyloid induced cytotoxicity to SH-SY5Y neuroblastoma cells, highlighting the potential of the glyconanoparticles for detection and imaging of beta amyloids. Sialic acid functionalized BSA (bovine serum albumin) nanoparticles also showed significant binding to beta amyloids, through ELISA and ex vivo mouse brain MRI experiments. Alternatively, the BBB crossing was demonstrated by several techniques such as confocal microscopy, endocytosis, exocytosis assays and were affirmed by nanoparticles transcytosis assays through bEnd.3 endothelial cells. Finally, the BBB crossing was confirmed by analyzing the MRI signal of nanoparticle-injected CD-1 mice.

  7. [Measurement of sialic acid from lipoproteins and human plasma by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Guo, Shoudong; Sang, Hui; Yang, Nana; Kan, Yujie; Li, Fuyu; Li, Yu; Li, Fangyuan; Qin, Shucun

    2014-11-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to quantify sialic acid (N-acetylneuraminic acid, NANA) from lipoproteins and human plasma. The method was used to investigate the different contents of NANA from lipoproteins between diabetic with an average age of 51.6 years and healthy participants with an average age of 50.7 years. The NANA from lipoprotein samples was hydrolyzed by acetic acid (pH = 2) at 80 °C for 2 h and analyzed by the optimized LC-MS/MS method after high speed centrifugation and filtration. The limits of detection and quantification of NANA were 7.4 and 24.5 pg, respectively. The linear range was 2.5-80 ng/mL for NANA and the correlation coefficient (R2) was more than 0.998. The levels of NANA in the plasma of type II diabetics and healthy participants were (548.3 ± 88.9) and (415.3 ± 55.5) mg/L, respectively; and the levels of NANA from very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) of the type II diabetics and the healthy participants were (4.91 ± 0.19), (6.95 ± 0.28), (3.61 ± 0.22) μg/mg and (2.90 ± 0.27), (7.03 ± 0.04), (2.40 ± 0.09) μg/mg, respectively. The sialic acid levels of VLDL and HDL from the type II diabetics were markedly higher than those of the corresponding healthy participants with the similar ages (P lipoproteins, and is reproducible and time saving.

  8. Sialic Acid on the Glycosylphosphatidylinositol Anchor Regulates PrP-mediated Cell Signaling and Prion Formation*

    Science.gov (United States)

    Bate, Clive; Nolan, William; Williams, Alun

    2016-01-01

    The prion diseases occur following the conversion of the cellular prion protein (PrPC) into disease-related isoforms (PrPSc). In this study, the role of the glycosylphosphatidylinositol (GPI) anchor attached to PrPC in prion formation was examined using a cell painting technique. PrPSc formation in two prion-infected neuronal cell lines (ScGT1 and ScN2a cells) and in scrapie-infected primary cortical neurons was increased following the introduction of PrPC. In contrast, PrPC containing a GPI anchor from which the sialic acid had been removed (desialylated PrPC) was not converted to PrPSc. Furthermore, the presence of desialylated PrPC inhibited the production of PrPSc within prion-infected cortical neurons and ScGT1 and ScN2a cells. The membrane rafts surrounding desialylated PrPC contained greater amounts of sialylated gangliosides and cholesterol than membrane rafts surrounding PrPC. Desialylated PrPC was less sensitive to cholesterol depletion than PrPC and was not released from cells by treatment with glimepiride. The presence of desialylated PrPC in neurons caused the dissociation of cytoplasmic phospholipase A2 from PrP-containing membrane rafts and reduced the activation of cytoplasmic phospholipase A2. These findings show that the sialic acid moiety of the GPI attached to PrPC modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrPSc formation. These results suggest that pharmacological modification of GPI glycosylation might constitute a novel therapeutic approach to prion diseases. PMID:26553874

  9. Sialic Acid on the Glycosylphosphatidylinositol Anchor Regulates PrP-mediated Cell Signaling and Prion Formation.

    Science.gov (United States)

    Bate, Clive; Nolan, William; Williams, Alun

    2016-01-01

    The prion diseases occur following the conversion of the cellular prion protein (PrP(C)) into disease-related isoforms (PrP(Sc)). In this study, the role of the glycosylphosphatidylinositol (GPI) anchor attached to PrP(C) in prion formation was examined using a cell painting technique. PrP(Sc) formation in two prion-infected neuronal cell lines (ScGT1 and ScN2a cells) and in scrapie-infected primary cortical neurons was increased following the introduction of PrP(C). In contrast, PrP(C) containing a GPI anchor from which the sialic acid had been removed (desialylated PrP(C)) was not converted to PrP(Sc). Furthermore, the presence of desialylated PrP(C) inhibited the production of PrP(Sc) within prion-infected cortical neurons and ScGT1 and ScN2a cells. The membrane rafts surrounding desialylated PrP(C) contained greater amounts of sialylated gangliosides and cholesterol than membrane rafts surrounding PrP(C). Desialylated PrP(C) was less sensitive to cholesterol depletion than PrP(C) and was not released from cells by treatment with glimepiride. The presence of desialylated PrP(C) in neurons caused the dissociation of cytoplasmic phospholipase A2 from PrP-containing membrane rafts and reduced the activation of cytoplasmic phospholipase A2. These findings show that the sialic acid moiety of the GPI attached to PrP(C) modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrP(Sc) formation. These results suggest that pharmacological modification of GPI glycosylation might constitute a novel therapeutic approach to prion diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Correlation of radiotherapy with serum total and lipid-bound sialic acid in OSCC patients

    Directory of Open Access Journals (Sweden)

    Saurabh Srivastava

    2014-01-01

    Full Text Available Context: Increased quantities of glycoconjugates such as Total Sialic Acid (TSA and Lipid-bound Sialic Acid (LSA have been detected in the plasma and serum of patients with various malignancies, indicating their usefulness in diagnosis or monitoring of the treatment modality. Aims: (1 To estimate and compare the serum TSA and LSA levels in Oral Squamous Cell Carcinoma (OSCC patients before and after radiotherapy, as also in healthy individuals. (2 To determine the correlation, if any, between Tumor-Node-Metastasis (TNM staging and levels of TSA and LSA. (3 To determine the use of serum TSA and LSA as biomarkers of OSCC. Settings and Design: The study was designed as a case-control study and was undertaken in a dental college and cancer hospital. Materials and Methods: It was planned to estimate the serum TSA and LSA levels of 20 healthy individuals and of 20 OSCC patients, spectrophotometrically; before starting and one month after completion of radiotherapy. Statistical Analysis: The Statistical Package for Social Sciences (SPSS Version 10.0 was used. Results: The mean serum TSA and LSA levels in OSCC patients decreased significantly after radiotherapy; however, they were still higher than the levels in the controls. In untreated OSCC patients, a statistically significant positive correlation was observed between the TNM stage of the disease and the serum TSA levels; but the same was not found between the TNM stage of the disease and the serum LSA levels. In OSCC, the serum TSA and LSA levels had a positive relationship with the TNM stages. These levels decreased significantly after radiotherapy. Conclusion: Serum TSA and LSA can be utilized as potential diagnostic and prognostic indicators in OSCC.

  11. Radiative Augmented Combustion.

    Science.gov (United States)

    1985-08-12

    86-0085 In 00I to RADIATIVE AUGMENTED COMBUSTION MOSHE LAVID M.L. ENERGIA , INC. P.O. BOX 1468 1 PRINCETON, NEW JERSEY 08542 AUGUST 1985 *.. plo...Combustion conducted at M.L. ENERGIA . It is funded by the Air Force Office of Scientific Research under Contract No. F49620-83-C-0133, with Dr. J.M...reported. It covers the second year of the contract, from July 15, 1984 through July 14, 1985. The work was performed at ENERGIA , Princeton, New Jersey

  12. AMI: Augmented Michelson Interferometer

    Science.gov (United States)

    Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

    2015-10-01

    Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

  13. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne

    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student...... involvement. The AR-sci-project (Augmented Reality for SCIence education) addresses the issue of applying augmented reality in developing innovative science education and enhancing the quality of science teaching and learning....

  14. Augmented reality in medical education?

    National Research Council Canada - National Science Library

    Kamphuis, Carolien; Barsom, Esther; Schijven, Marlies; Christoph, Noor

    2014-01-01

    .... Educational technology and more specifically augmented reality (AR) has the potential to offer a highly realistic situated learning experience supportive of complex medical learning and transfer...

  15. Effects of Tamm-Horsfall protein with normal and reduced sialic acid content upon the crystallization of calcium phosphate and calcium oxalate in human urine

    National Research Council Canada - National Science Library

    Hallson, P C; Choong, S K; Kasidas, G P; Samuell, C T

    1997-01-01

    To examine the effects of Tamm-Horsfall protein (THP) of normal and low sialic acid content on urinary crystallization, and establish whether there are changes conducive to the formation of kidney stones...

  16. Anti-Aβ Oligomer IgG and Surface Sialic Acid in Intravenous Immunoglobulin: Measurement and Correlation with Clinical Outcomes in Alzheimer’s Disease Treatment

    Science.gov (United States)

    Kwon, Hyewon; Finke, John M.

    2015-01-01

    The fraction of IgG antibodies with anti-oligomeric Aβ affinity and surface sialic acid was compared between Octagam and Gammagard intravenous immunoglobulin (IVIG) using two complementary surface plasmon resonance methods. These comparisons were performed to identify if an elevated fraction existed in Gammagard, which reported small putative benefits in a recent Phase III clinical trial for Alzheimer’s Disease. The fraction of anti-oligomeric Aβ IgG was found to be higher in Octagam, for which no cognitive benefits were reported. The fraction and location of surface-accessible sialic acid in the Fab domain was found to be similar between Gammagard and Octagam. These findings indicate that anti-oligomeric Aβ IgG and total surface sialic acid alone cannot account for reported clinical differences in the two IVIG products. A combined analysis of sialic acid in anti-oligomeric Aβ IgG did reveal a notable finding that this subgroup exhibited a high degree of surface sialic acid lacking the conventional α2,6 linkage. These results demonstrate that the IVIG antibodies used to engage oligomeric Aβ in both Gammagard and Octagam clinical trials did not possess α2,6-linked surface sialic acid at the time of administration. Anti-oligomeric Aβ IgG with α2,6 linkages remains untested as an AD treatment. PMID:25826319

  17. [Augmented spontaneous breathing].

    Science.gov (United States)

    Hachenberg, T

    1996-09-01

    Impaired pulmonary gas exchange can result from lung parenchymal failure inducing oxygenation deficiency and fatigue of the respiratory muscles, which is characterized by hypercapnia or a combination of both mechanisms. Contractility of and coordination between the diaphragm and the thoracoabdominal respiratory muscles predominantly determine the efficiency of spontaneous breathing. Sepsis, cardiac failure, malnutrition or acute changes of the load conditions may induce fatigue of the respiratory muscles. Augmentation of spontaneous breathing is not only achieved by the application of different technical principles or devices; it also has to improve perfusion, metabolism, load conditions and contractility of the respiratory muscles. Intermittent mandatory ventilation (IMV) allows spontaneous breathing of the patient and augments alveolar ventilation by periodically applying positive airway pressure tidal volumes, which are generated by the respirator. Potential advantages include lower mean airway pressure (PAW), as compared with controlled mechanical ventilation, and improved haemodynamics. Suboptimal IMV systems may impose increased work and oxygen cost of breathing, fatigue of the respiratory muscles and CO2 retention. During pressure support ventilation (PSV), inspiratory alterations of PAW or gas flow (trigger) are detected by the respirator, which delivers a gas flow to maintain PAW at a fixed value (usually 5-20 cm H2O) during inspiration. PSV may be combined with other modalities of respiratory therapy such as IMV or CPAP. Claimed advantages of PSV include decreased effort of breathing, reduced systemic and respiratory muscle consumption of oxygen, prophylaxis of diaphragmatic fatigue and an improved extubation rate after prolonged periods of mechanical ventilation. Minimum alveolar ventilation is not guaranteed during PSV; thus, close observation of the patient is mandatory to avoid serious respiratory complications. Continuous positive airway pressure

  18. Augmented reality system

    Science.gov (United States)

    Lin, Chien-Liang; Su, Yu-Zheng; Hung, Min-Wei; Huang, Kuo-Cheng

    2010-08-01

    In recent years, Augmented Reality (AR)[1][2][3] is very popular in universities and research organizations. The AR technology has been widely used in Virtual Reality (VR) fields, such as sophisticated weapons, flight vehicle development, data model visualization, virtual training, entertainment and arts. AR has characteristics to enhance the display output as a real environment with specific user interactive functions or specific object recognitions. It can be use in medical treatment, anatomy training, precision instrument casting, warplane guidance, engineering and distance robot control. AR has a lot of vantages than VR. This system developed combines sensors, software and imaging algorithms to make users feel real, actual and existing. Imaging algorithms include gray level method, image binarization method, and white balance method in order to make accurate image recognition and overcome the effects of light.

  19. Augmented Virtual Reality Laboratory

    Science.gov (United States)

    Tully-Hanson, Benjamin

    2015-01-01

    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  20. Today in breast augmentation

    Directory of Open Access Journals (Sweden)

    Juan Manuel Calderón

    2016-02-01

    Full Text Available Breast augmentation is one of the most commonly performed procedures worldwide among aesthetic reconstructive surgeries. Among the indications for performing the procedure are primary and secondary alterations related to breasts shape and volume. During the initial assessment, emphasis should be placed in the anamnesis and physical examination, allowing to define target sizing and realistic expectations to prospectively determine the possible postoperative satisfaction rates. There are several methods used to select the appropriate implants that have become more accurate with time and with the use of technology. Although there are multiple materials developed, to this moment silicone implants continue to be the ones most used worldwide with low complication rates depending on each patient and on the technique used. It is considered as one of the aesthetic reconstructive surgeries with the highest degree of acceptance among the general population who undergo this type of procedures.

  1. Augmented nonlinear differentiator design

    Science.gov (United States)

    Shao, Xingling; Liu, Jun; Yang, Wei; Tang, Jun; Li, Jie

    2017-06-01

    This paper presents a sigmoid function based augmented nonlinear differentiator (AND) for calculating the noise-less time derivative from a noisy measurement. The prominent advantages of the present differentiation technique are: (i) compared to the existing tracking differentiators, better noise suppression ability can be achieved without appreciable delay; (ii) the enhanced noise-filtering mechanism not only can be applied to the designed differentiator, but also can be extended for improving noise-tolerance capability of the available differentiators. In addition, the convergence property and robustness performance against noises are investigated via singular perturbation theory and describing function method, respectively. Also, comparison with several classical differentiators is given to illustrate the superiority of AND in noise suppression. Finally, applications on autopilot design and displacement following for nonlinear mass spring mechanical system are given to demonstrate the effectiveness and applicability of the proposed AND technique.

  2. Maxillary sinus augmentation

    Directory of Open Access Journals (Sweden)

    A B Tarun Kumar

    2015-01-01

    Full Text Available Placing dental implants in the maxillary posterior region can be both challenging and un-nerving for a regular implant dentist who is not well versed with advanced surgical procedures. It is vital for a general dentist to understand the fundamentals of bone grafting the maxillary sinus if he/she is really committed to providing the best health care for their patients. The dental practice is seeing an increasing group of patients who are living longer, and this group of older baby boomers often has an edentulous posterior maxilla either unilateral or bilateral. When edentulous, the posterior maxilla more likely has diminished bone height, which does not allow for the placement of dental implants without creating additional bone. Through grafting the maxillary sinus, bone of ideal quality can be created (allowing for placement of dental implants, which offer many advantages over other tooth replacement modalities. The sinus graft offers the dental patient a predictable procedure of regenerating lost osseous structure in the posterior maxilla. This offers the patient many advantages for long-term success. If dentists understand these concepts, they can better educate their patients and guide them to have the procedure performed. This article outlines bone grafting of the maxillary sinus for the purpose of placing dental implants. This review will help the readers to understand the intricacies of sinus augmentation. They can relate their patient's condition with the available literature and chalk out the best treatment plan for the patient, especially by using indirect sinus augmentation procedures which are less invasive and highly successful if done using prescribed technique.

  3. Augmented Reality Comes to Physics

    Science.gov (United States)

    Buesing, Mark; Cook, Michael

    2013-01-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

  4. The Augmented REality Sandtable (ARES)

    Science.gov (United States)

    2015-10-01

    Augmented Reality Interface Tactical map with browser and manipulators / tangible markers Yes Yes Unknown No Kalphat (2009) Tactical......Augmented REality Sandtable (ARES) by Charles R Amburn, Nathan L Vey, and MAJ Jerry R Mize Human Research and Engineering Directorate, ARL Michael

  5. Rapid adhesion of nerve cells to muscle fibers from adult rats is mediated by a sialic acid-binding receptor

    OpenAIRE

    1986-01-01

    Single viable muscle fibers isolated from adult rats by collagenase digestion rapidly bind dissociated spinal neurons or PC-12 cells but not a variety of other cells tested. The adhesion process is calcium- independent, temperature-sensitive, and is not blocked by pretreating cells with inhibitors of energy metabolism or actin polymerization. Adhesion is mediated by a carbohydrate-binding protein and can be inhibited by N-acetylneuraminic acid or mucin, a glycoprotein with high sialic acids c...

  6. Host-Derived Sialic Acids Are an Important Nutrient Source Required for Optimal Bacterial Fitness In Vivo

    Directory of Open Access Journals (Sweden)

    Nathan D. McDonald

    2016-04-01

    Full Text Available A major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota. Vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. In this study, we demonstrated that V. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite ATP-independent periplasmic SiaPQM strain, transporter-deficient mutant NC1777, was attenuated for colonization using a streptomycin-pretreated adult mouse model. In in vivo competition assays, NC1777 was significantly outcompeted for up to 3 days postinfection. NC1777 was also significantly outcompeted in in vitro competition assays in M9 minimal medium supplemented with intestinal mucus, indicating that sialic acid uptake is essential for fitness. Phylogenetic analyses demonstrated that the ability to utilize sialic acid was distributed among 452 bacterial species from eight phyla. The majority of species belonged to four phyla, Actinobacteria (members of Actinobacillus, Corynebacterium, Mycoplasma, and Streptomyces, Bacteroidetes (mainly Bacteroides, Capnocytophaga, and Prevotella, Firmicutes (members of Streptococcus, Staphylococcus, Clostridium, and Lactobacillus, and Proteobacteria (including Escherichia, Shigella, Salmonella, Citrobacter, Haemophilus, Klebsiella, Pasteurella, Photobacterium, Vibrio, and Yersinia species, mostly commensals and/or pathogens. Overall, our data demonstrate that the ability to take up host-derived sugars and sialic acid specifically allows V. cholerae a competitive advantage in intestinal colonization and that this is a trait that is sporadic in its occurrence and phylogenetic distribution and ancestral in some genera but horizontally acquired in others.

  7. The random co-polymer glatiramer acetate rapidly kills primary human leukocytes through sialic-acid-dependent cell membrane damage

    DEFF Research Database (Denmark)

    Christiansen, Stig Hill; Zhang, Xianwei; Juul-Madsen, Kristian

    2017-01-01

    in innate immunity. It shares the positive charge and amphipathic character of GA, and, as shown here, also the ability to kill human leukocyte. The cytotoxicity of both compounds depends on sialic acid in the cell membrane. The killing was associated with the generation of CD45 + debris, derived from cell...... of certain oligomeric and chemical properties to support cytotoxic effects of cationic polymers targeting human leukocytes....

  8. Sialic acid residues on astrocytes regulate neuritogenesis by controlling the assembly of laminin matrices.

    Science.gov (United States)

    Freire, Elisabete; Gomes, Flávia C A; Jotha-Mattos, Tatiana; Neto, Vivaldo Moura; Silva Filho, Fernando C; Coelho-Sampaio, Tatiana

    2004-08-15

    In the developing nervous system migrating neurons and growing axons are guided by diffusible and/or substrate-bound cues, such as extracellular matrix-associated laminin. In a previous work we demonstrated that laminin molecules could self-assemble in two different manners, giving rise to matrices that could favor either neuritogenesis or proliferation of cortical precursor cells. We investigated whether the ability of astrocytes to promote neuritogenesis of co-cultivated neurons was modulated by the assembling mode of the laminin matrix secreted by them. We compared the morphologies and neuritogenic potentials of laminin deposited by in vitro-differentiated astrocytes obtained from embryonic or neonatal rat brain cortices. We showed that, while permissive astrocytes derived from embryonic brain produced a flat laminin matrix that remained associated to the cell surface, astrocytes derived from newborn brain secreted a laminin matrix resembling a fibrillar web that protruded from the cell plane. The average neurite lengths obtained for E16 neurons cultured on each astrocyte layer were 198+/-22 and 123+/-13 microm, respectively. Analyses of surface-associated electrostatic potentials revealed that embryonic astrocytes presented a pI of -2.8, while in newborn cells this value was -3.8. Removal of the sialic acid groups on the embryonic monolayer by neuraminidase treatment led to the immediate release of matrix-associated laminin. Interestingly, laminin reassembled 1 hour after neuraminidase removal converted to the features of the newborn matrix. Alternatively, treatment of astrocytes with the cholesterol-solubilizing detergent methyl-beta-cyclodextrin also resulted in release of the extracellular laminin. To test the hypothesis that sialic-acid-containing lipids localized at cholesterol-rich membrane domains could affect the process of laminin assembly, we devised a cell-free assay where laminin polymerization was carried out over artificial lipid films. Films of

  9. Comparative distribution of human and avian type sialic acid influenza receptors in the pig

    Directory of Open Access Journals (Sweden)

    Perez Belinda

    2010-01-01

    Full Text Available Abstract Background A major determinant of influenza infection is the presence of virus receptors on susceptible host cells to which the viral haemagglutinin is able to bind. Avian viruses preferentially bind to sialic acid α2,3-galactose (SAα2,3-Gal linked receptors, whereas human strains bind to sialic acid α2,6-galactose (SAα2,6-Gal linked receptors. To date, there has been no detailed account published on the distribution of SA receptors in the pig, a model host that is susceptible to avian and human influenza subtypes, thus with potential for virus reassortment. We examined the relative expression and spatial distribution of SAα2,3-GalG(1-3GalNAc and SAα2,6-Gal receptors in the major organs from normal post-weaned pigs by binding with lectins Maackia amurensis agglutinins (MAA II and Sambucus nigra agglutinin (SNA respectively. Results Both SAα2,3-Gal and SAα2,6-Gal receptors were extensively detected in the major porcine organs examined (trachea, lung, liver, kidney, spleen, heart, skeletal muscle, cerebrum, small intestine and colon. Furthermore, distribution of both SA receptors in the pig respiratory tract closely resembled the published data of the human tract. Similar expression patterns of SA receptors between pig and human in other major organs were found, with exception of the intestinal tract. Unlike the limited reports on the scarcity of influenza receptors in human intestines, we found increasing presence of SAα2,3-Gal and SAα2,6-Gal receptors from duodenum to colon in the pig. Conclusions The extensive presence of SAα2,3-Gal and SAα2,6-Gal receptors in the major organs examined suggests that each major organ may be permissive to influenza virus entry or infection. The high similarity of SA expression patterns between pig and human, in particular in the respiratory tract, suggests that pigs are not more likely to be potential hosts for virus reassortment than humans. Our finding of relative abundance of SA receptors

  10. Characterization of the Adeno-Associated Virus 1 and 6 Sialic Acid Binding Site.

    Science.gov (United States)

    Huang, Lin-Ya; Patel, Ami; Ng, Robert; Miller, Edward Blake; Halder, Sujata; McKenna, Robert; Asokan, Aravind; Agbandje-McKenna, Mavis

    2016-06-01

    The adeno-associated viruses (AAVs), which are being developed as gene delivery vectors, display differential cell surface glycan binding and subsequent tissue tropisms. For AAV serotype 1 (AAV1), the first viral vector approved as a gene therapy treatment, and its closely related AAV6, sialic acid (SIA) serves as their primary cellular surface receptor. Toward characterizing the SIA binding site(s), the structure of the AAV1-SIA complex was determined by X-ray crystallography to 3.0 Å. Density consistent with SIA was observed in a pocket located at the base of capsid protrusions surrounding icosahedral 3-fold axes. Site-directed mutagenesis substitution of the amino acids forming this pocket with structurally equivalent residues from AAV2, a heparan sulfate binding serotype, followed by cell binding and transduction assays, further mapped the critical residues conferring SIA binding to AAV1 and AAV6. For both viruses five of the six binding pocket residues mutated (N447S, V473D, N500E, T502S, and W503A) abolished SIA binding, whereas S472R increased binding. All six mutations abolished or decreased transduction by at least 50% in AAV1. Surprisingly, the T502S substitution did not affect transduction efficiency of wild-type AAV6. Furthermore, three of the AAV1 SIA binding site mutants-S472R, V473D, and N500E-escaped recognition by the anti-AAV1 capsid antibody ADK1a. These observations demonstrate that common key capsid surface residues dictate both virus binding and entry processes, as well as antigenic reactivity. This study identifies an important functional capsid surface "hot spot" dictating receptor attachment, transduction efficiency, and antigenicity which could prove useful for vector engineering. The adeno-associated virus (AAV) vector gene delivery system has shown promise in several clinical trials and an AAV1-based vector has been approved as the first gene therapy treatment. However, limitations still exist with respect to transduction efficiency and

  11. Assay of urinary protein-bound sialic acid can differentiate steroidsensitive nephrotic syndrome from steroid-resistant cases

    Directory of Open Access Journals (Sweden)

    Niranjan Gopal

    2016-01-01

    Full Text Available The protein selectivity index as measured from the ratio of urinary immunoglobulin to albumin failed to differentiate between steroid-sensitive (SS and steroid-resistant (SR cases of nephrotic syndrome (NS. Sialic acid contributes negative charges to many plasma proteins. The negative charge is a determinant of protein excretion rate. The prognostic significance of assay of urinary excretion of protein-bound sialic acid in NS has not been evaluated. Hence, the present study was designed to evaluate whether measurement of urinary protein bound sialic acid (UPBSA can be used as a marker to differentiate SS from SR cases of NS. The urine samples of 70 (47 SS and 23 SR pediatric NS children were assayed for UPBSA by Aminoff′s method. The levels were compared and the receiver-operator curve was drawn to determine the optimum cutoff point to differentiate among the groups before starting the therapy. The excretion of UPBSA in SR cases of NS was significantly higher than that of SS cases (P<0.05. The optimum cutoff limit for UPBSA was 2.71 μg/mg of proteins with 75% sensitivity and 75.5% specificity for differentiating SS cases from SR cases (area under the plasma- concentration time curve = 0.814, P = 0.009. We conclude that UPBSA can differentiate SR cases from SS cases of NS in pediatric patients and may help in predicting the response to steroid therapy.

  12. Differential effects of unnatural sialic acids on the polysialylation of the neural cell adhesion molecule and neuronal behavior.

    Science.gov (United States)

    Charter, Neil W; Mahal, Lara K; Koshland, Daniel E; Bertozzi, Carolyn R

    2002-03-15

    In this study we have examined how unnatural sialic acids can alter polysialic acid expression and influence the adhesive properties of the neural cell adhesion molecule (NCAM). Unnatural sialic acids are generated by metabolic conversion of synthetic N-acyl mannosamines and are typically incorporated into cell-surface glycoconjugates. However, N-butanoylmannosamine and N-pentanoylmannosamine are effective inhibitors of polysialic acid (PSA) synthesis in stably transfected HeLa cells expressing NCAM and the polysialyltransferase STX. These cells were used as substrates to examine the effect of inhibiting PSA synthesis on the development of neurons derived from the chick dorsal root ganglion. N-butanoylmannosamine blocked polysialylation of NCAM and significantly reduced neurite outgrowth comparable with enzymatic removal of PSA by endoneuraminidases. As a result, neurite outgrowth was similar to that observed for non-polysialylated NCAM. In contrast, previous studies have shown that N-propanoyl sialic acid (SiaProp), generated from N-propanoylmannosamine, is readily accepted by polysialyltransferases and permits the extension of poly(SiaProp) on NCAM. Despite being immunologically distinct, poly(SiaProp) can promote neurite outgrowth similarly to natural polysialic acid. Thus, subtle structural differences in PSA resulting from the incorporation of SiaProp residues do not alter the antiadhesive properties of polysialylated NCAM.

  13. Sialic acid-binding dwarf elder four-chain lectin displays nucleic acid N-glycosidase activity.

    Science.gov (United States)

    Iglesias, Rosario; Citores, Lucía; Ferreras, J Miguel; Pérez, Yolanda; Jiménez, Pilar; Gayoso, Manuel J; Olsnes, Sjur; Tamburino, Rachele; Di Maro, Antimo; Parente, Augusto; Girbés, Tomás

    2010-01-01

    Sialic acid-binding dwarf elder agglutinin (SEA) present only in rhizomes of the medicinal plant Sambucus ebulus L., was found to be a tetrameric glycoprotein consisting of two covalently-associated dimers of an enzymic A chain with rRNA N-glycosidase activity (EC 3.2.2.22) linked to a B chain with agglutinin properties. The lectin inhibited protein synthesis by a cell-free system and depurinated ribosomes. Cloning of the corresponding gene and molecular modeling of the deduced amino acid sequence demonstrated that SEA has a three-dimensional structure which resembles that reported for other two tetrameric type 2 RIPs from Sambucus (SNAI and SSA). The lectin agglutinated red blood cells and displayed sugar affinity for sialic acid residues apart from d-galactose, binding to the mucin-producing gut goblet cells. Since sialic acid is present in animal cells, especially in epithelial lining gut cells, but not in plants, SEA could play a role in the defense against insect attack. The nucleotide sequence reported in this paper has been submitted to the GenBank nucleotide database under accession number AM981401. 2009 Elsevier Masson SAS. All rights reserved.

  14. Molecular Mechanism Underlying Sialic Acid as an Essential Nutrient for Brain Development and Cognition123

    Science.gov (United States)

    Wang, Bing

    2012-01-01

    The early stages of neurodevelopment in infants are crucial for establishing neural structures and synaptic connections that influence brain biochemistry well into adulthood. This postnatal period of rapid neural growth is of critical importance for cell migration, neurite outgrowth, synaptic plasticity, and axon fasciculation. These processes thus place an unusually high demand on the intracellular pool of nutrients and biochemical precursors. Sialic acid (Sia), a family of 9-carbon sugar acids, occurs in large amounts in human milk oligosaccharides and is an essential component of brain gangliosides and sialylated glycoproteins, particularly as precursors for the synthesis of the polysialic acid (polySia) glycan that post-translationally modify the cell membrane-associated neural cell adhesion molecules (NCAM). Human milk is noteworthy in containing exceptionally high levels of Sia-glycoconjugates. The predominate form of Sia in human milk is N-acetylneuraminic acid (Neu5Ac). Infant formula, however, contains low levels of Sia consisting of both Neu5Ac and N-glycolyneuraminic acid (Neu5Gc). Current studies implicate Neu5Gc in several human inflammatory diseases. Polysialylated NCAM and neural gangliosides both play critical roles in mediating cell-to-cell interactions important for neuronal outgrowth, synaptic connectivity, and memory formation. A diet rich in Sia also increases the level of Sia in the brains of postnatal piglets, the expression level of 2 learning-related genes, and enhances learning and memory. PMID:22585926

  15. Expression, solubilisation, and purification of a functional CMP-sialic acid transporter in Pichia pastoris.

    Science.gov (United States)

    Maggioni, Andrea; Hadley, Barbara; von Itzstein, Mark; Tiralongo, Joe

    2014-09-01

    Membrane proteins, including solute transporters play crucial roles in cellular function and have been implicated in a variety of important diseases, and as such are considered important targets for drug development. Currently the drug discovery process is heavily reliant on the structural and functional information discerned from high-resolution crystal structures. However, membrane protein structure determination is notoriously difficult, due in part to challenges faced in their expression, solubilisation and purification. The CMP-sialic acid transporter (CST) is considered to be an attractive target for drug discovery. CST inhibition reduces cancer cell sialylation and decreases the metastatic potential of cancer cells and to date, no crystal structure of the CST, or any other nucleotide sugar transporter exists. Here we describe the optimised conditions for expression in Pichia pastoris, solubilisation using n-nonyl β-d-maltopyranoside (NM) and single step purification of a functional CST. Importantly we show that despite being able to solubilise and purify the CST using a number of different detergents, only NM was able to maintain CST functionality. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Molecular mechanism underlying sialic acid as an essential nutrient for brain development and cognition.

    Science.gov (United States)

    Wang, Bing

    2012-05-01

    The early stages of neurodevelopment in infants are crucial for establishing neural structures and synaptic connections that influence brain biochemistry well into adulthood. This postnatal period of rapid neural growth is of critical importance for cell migration, neurite outgrowth, synaptic plasticity, and axon fasciculation. These processes thus place an unusually high demand on the intracellular pool of nutrients and biochemical precursors. Sialic acid (Sia), a family of 9-carbon sugar acids, occurs in large amounts in human milk oligosaccharides and is an essential component of brain gangliosides and sialylated glycoproteins, particularly as precursors for the synthesis of the polysialic acid (polySia) glycan that post-translationally modify the cell membrane-associated neural cell adhesion molecules (NCAM). Human milk is noteworthy in containing exceptionally high levels of Sia-glycoconjugates. The predominate form of Sia in human milk is N-acetylneuraminic acid (Neu5Ac). Infant formula, however, contains low levels of Sia consisting of both Neu5Ac and N-glycolyneuraminic acid (Neu5Gc). Current studies implicate Neu5Gc in several human inflammatory diseases. Polysialylated NCAM and neural gangliosides both play critical roles in mediating cell-to-cell interactions important for neuronal outgrowth, synaptic connectivity, and memory formation. A diet rich in Sia also increases the level of Sia in the brains of postnatal piglets, the expression level of 2 learning-related genes, and enhances learning and memory.

  17. Sialic acid is an essential nutrient for brain development and cognition.

    Science.gov (United States)

    Wang, Bing

    2009-01-01

    The rapid growth of infant brains places an exceptionally high demand on the supply of nutrients from the diet, particularly for preterm infants. Sialic acid (Sia) is an essential component of brain gangliosides and the polysialic acid (polySia) chains that modify neural cell adhesion molecules (NCAM). Sia levels are high in human breast milk, predominately as N-acetylneuraminic acid (Neu5Ac). In contrast, infant formulas contain a low level of Sia consisting of both Neu5Ac and N-glycolylneuraminic acid (Neu5Gc). Neu5Gc is implicated in some human inflammatory diseases. Brain gangliosides and polysialylated NCAM play crucial roles in cell-to-cell interactions, neuronal outgrowth, modifying synaptic connectivity, and memory formation. In piglets, a diet rich in Sia increases the level of brain Sia and the expression of two learning-related genes and enhances learning and memory. The purpose of this review is to summarize the evidence showing the importance of dietary Sia as an essential nutrient for brain development and cognition.

  18. Understanding augmented reality concepts and applications

    CERN Document Server

    Craig, Alan B

    2013-01-01

    Augmented reality is not a technology. Augmented reality is a medium. Likewise, a book on augmented reality that only addresses the technology that is required to support the medium of augmented reality falls far short of providing the background that is needed to produce, or critically consume augmented reality applications. One reads a book. One watches a movie. One experiences augmented reality. Understanding Augmented Reality addresses the elements that are required to create compelling augmented reality experiences. The technology that supports

  19. Augmented Reality Comes to Physics

    Science.gov (United States)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  20. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne

    2015-01-01

    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student i...... involvement. The AR-sci-project (Augmented Reality for SCIence education) addresses the issue of applying augmented reality in developing innovative science education and enhancing the quality of science teaching and learning....

  1. Augmented reality som wearable technology

    DEFF Research Database (Denmark)

    Rahn, Annette

    the potential of Augmented reality increasing students level of understanding, interaction and engagement with the object. I will demonstrate the technology and show you the human lungs in your body and the future perspectives of the technology. Organization: developed in collaboration with Mie Buhl, Professor......“How Augmented reality can facilitate learning in visualizing human anatomy “ At this station I demonstrate how Augmented reality can be used to visualize the human lungs in situ and as a wearable technology which establish connection between body, image and technology in education. I will show...

  2. Crime Scenes as Augmented Reality

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    2010-01-01

    , physical damage: they are all readable and interpretable signs. As augmented reality the crime scene carries a narrative which at first is hidden and must be revealed. Due to the process of investigation and the detective's ability to reason and deduce, the crime scene as place is reconstructed as virtual......Using the concept of augmented reality, this article will investigate how places in various ways have become augmented by means of different mediatization strategies. Augmentation of reality implies an enhancement of the places' emotional character: a certain mood, atmosphere or narrative surplus...... of meaning has been implemented. This may take place at different levels, which will be presented and investigated in this article and exemplified by some cases from the fields of tourism and computer games.                       The article suggests that we may use the forensic term crime scene in order...

  3. Military Applications of Augmented Reality

    Science.gov (United States)

    2011-01-01

    interest in AR technology has a long history. The Ultrasound Augmented Reality project [State et al(1996)] is one note- worthy example of a project...Many military bases have “towns” for training that consist of concrete block buildings with multiple levels and architec- tural configurations. AR...Livingston MA, Hirota G, Garrett WF, Whitton MC, Pisano ED, Fuchs H (1996) Technologies for augmented reality systems: Realizing ultrasound -guided

  4. Alpha2,3 and alpha2,6 N-linked sialic acids facilitate efficient binding and transduction by adeno-associated virus types 1 and 6.

    Science.gov (United States)

    Wu, Zhijian; Miller, Edward; Agbandje-McKenna, Mavis; Samulski, Richard Jude

    2006-09-01

    Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be the attachment receptors for AAV type 2 and types 4 and 5, respectively. In this report, we identify the receptor for the two closely related serotypes, AAV1 and AAV6. First, we demonstrate using coinfection experiments and luciferase reporter analysis that AAV1 and AAV6 compete for similar receptors. Unlike heparin sulfate, enzymatic or genetic removal of sialic acid markedly reduced AAV1 and AAV6 binding and transduction. Further analysis using lectin staining and lectin competition assays identified that AAV1 and AAV6 use either alpha2,3-linked or alpha2,6-linked sialic acid when transducing numerous cell types (HepG2, Pro-5, and Cos-7). Treatment of cells with proteinase K but not glycolipid inhibitor reduced AAV1 and AAV6 infection, supporting the hypothesis that the sialic acid that facilitates infection is associated with glycoproteins rather than glycolipids. In addition, we determined by inhibitor (N-benzyl GalNAc)- and cell line-specific (Lec-1) studies that AAV1 and AAV6 require N-linked and not O-linked sialic acid. Furthermore, a resialylation experiment on a deficient Lec-2 cell line confirmed a 2,3 and 2,6 N-linked sialic acid requirement, while studies of mucin with O-linked sialic acid showed no inhibition effect for AAV1 and AAV6 transduction on Cos-7 cells. Finally, using a glycan array binding assay we determined that AAV1 efficiently binds to NeuAcalpha2-3GalNAcbeta1-4GlcNAc, as well as two glycoproteins with alpha2,3 and alpha2,6 N-linked sialic acids. Taken together, competition, genetic, inhibitor, enzymatic reconstitution, and glycan array experiments support alpha2,3 and alpha2,6 sialic acids that

  5. α2,3 and α2,6 N-Linked Sialic Acids Facilitate Efficient Binding and Transduction by Adeno-Associated Virus Types 1 and 6

    Science.gov (United States)

    Wu, Zhijian; Miller, Edward; Agbandje-McKenna, Mavis; Samulski, Richard Jude

    2006-01-01

    Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be the attachment receptors for AAV type 2 and types 4 and 5, respectively. In this report, we identify the receptor for the two closely related serotypes, AAV1 and AAV6. First, we demonstrate using coinfection experiments and luciferase reporter analysis that AAV1 and AAV6 compete for similar receptors. Unlike heparin sulfate, enzymatic or genetic removal of sialic acid markedly reduced AAV1 and AAV6 binding and transduction. Further analysis using lectin staining and lectin competition assays identified that AAV1 and AAV6 use either α2,3-linked or α2,6-linked sialic acid when transducing numerous cell types (HepG2, Pro-5, and Cos-7). Treatment of cells with proteinase K but not glycolipid inhibitor reduced AAV1 and AAV6 infection, supporting the hypothesis that the sialic acid that facilitates infection is associated with glycoproteins rather than glycolipids. In addition, we determined by inhibitor (N-benzyl GalNAc)- and cell line-specific (Lec-1) studies that AAV1 and AAV6 require N-linked and not O-linked sialic acid. Furthermore, a resialylation experiment on a deficient Lec-2 cell line confirmed a 2,3 and 2,6 N-linked sialic acid requirement, while studies of mucin with O-linked sialic acid showed no inhibition effect for AAV1 and AAV6 transduction on Cos-7 cells. Finally, using a glycan array binding assay we determined that AAV1 efficiently binds to NeuAcα2-3GalNAcβ1-4GlcNAc, as well as two glycoproteins with α2,3 and α2,6 N-linked sialic acids. Taken together, competition, genetic, inhibitor, enzymatic reconstitution, and glycan array experiments support α2,3 and α2,6 sialic acids that are present on N

  6. Immunoreactivity of the 14F7 Mab (Raised against N-Glycolyl GM3 Ganglioside as a Positive Prognostic Factor in Non-Small-Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Rancés Blanco

    2012-01-01

    Full Text Available Lung carcinoma is the leading cause of cancer-related mortality worldwide. Therefore, numerous studies are focusing on the assessment of other biological and molecular prognostic factors in these tumors. We evaluated the relationship between 14F7 Mab reactivity, pathological features, DNA-content and S-phase fraction (SPF, and their impact in the survival of NSCLC patients. Hematoxylin and eosin staining and immunohistochemistry optical microscopy assays as well as DNA content and SPF measuring using flow cytometry were performed. The 14F7 reactivity was widely observed in NSCLC sections, no depending of the clinicopathological characteristics. We also obtained differences in the intensity of reaction with 14F7 as well as in the SPF between diploid and aneuploid carcinomas. Patients with diploid tumors showing higher SPF and 14F7 reaction joint to a low mitotic index displayed higher survival rates. Our results are in agreement with the assumption of the possible positive prognostic value of 14F7 staining in NSCLC.

  7. Comparative analysis of salivary sialic acid levels in patients with chronic obstructive pulmonary disease and chronic periodontitis patients: A biochemical study

    Directory of Open Access Journals (Sweden)

    Surekha Rathod

    2018-01-01

    Full Text Available Aim: Sialic acid plays a central role in the functioning of biological systems, in stabilizing the glycoproteins and cellular membranes, assisting in cell–cell recognition and interaction. The aim of this study is to evaluate and compare the periodontal health status and salivary Sialic acid levels in patients suffering from chronic obstructive pulmonary diseases (COPD and chronic periodontitis patients. Materials and Methods: Ninety subjects were included in the study, which were divided into the following groups, 30 in each group. Group 1: patients suffering from COPD and chronic periodontitis, Group 2: periodontitis patients without any systemic diseases Group 3: healthy subjects. Unstimulated whole saliva samples were collected around 9–10 AM; 2 h after the subjects had breakfast. The sialic acid content was determined by a combined modification of the thiobarbituric acid method of Skoza and Mohos. Results: The mean salivary sialic acid levels were least in the healthy group followed by the periodontitis group, and it was highest in the COPD group. Conclusions: We can thus conclude that promotion of dental care knowledge is very much essential in the prevention and treatment of COPD. Thus, estimation of levels of salivary sialic acid can be used as an adjunct to diagnose the current periodontal disease status and to assess the treatment outcomes in subjects with COPD and chronic periodontitis.

  8. Asthma induction in mice leads to appearance of alpha2-3- and alpha2-6-linked sialic acid residues in respiratory goblet-like cells

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Jensen, Niels-Erik Viby; Mandel, Ulla

    2008-01-01

    Allergic asthmatic inflammation in mice was induced by sensitization with ovalbumin and lipopolysaccharide from Escherichia coli and visualized in the airways of asthmatic mice by spatial and temporal changes of carbohydrates containing sialic acid residues. Immunohistochemistry was used to demon......Allergic asthmatic inflammation in mice was induced by sensitization with ovalbumin and lipopolysaccharide from Escherichia coli and visualized in the airways of asthmatic mice by spatial and temporal changes of carbohydrates containing sialic acid residues. Immunohistochemistry was used...... to demonstrate binding of lectins and antibodies that detect alpha2-3- and alpha2-6-linked sialic acid residues. After sensitization and challenge, the histology of the lung changed markedly, and goblet-like cells appeared, most likely caused by Clara cell metaplasia. Normal Clara cells showed no reaction after...... incubation with the sialic acid detecting agents, while the goblet-like cells expressed both alpha2-3- and alpha2-6-linked sialic acid residues in the asthmatic animals. The lectins but not the antibodies reacted with intestinal goblet cells. Instead, an antibody recognizing a disialoganglioside, stained...

  9. Analysis of the changes in expression levels of sialic acid on influenza-virus-infected cells using lectin-tagged polymeric nanoparticles

    Directory of Open Access Journals (Sweden)

    Jaebum Cho

    2016-07-01

    Full Text Available Viral infections affect millions around the world, sometimes leading to severe consequences or even epidemics. Understanding the molecular dynamics during viral infections would provide crucial information for preventing or stopping the progress of infections. However, the current methods often involve the disruption of the infected cells or expensive and time-consuming procedures. In this study, fluorescent polymeric nanoparticles were fabricated and used as bioimaging nanoprobes that can monitor the progression of influenza viral infection through the changes in the expression levels of sialic acids expressed on the cell membrane. The nanoparticles were composed of a biocompatible monomer to prevent non-specific interactions, a hydrophobic monomer to form the core, a fluorescent monomer, and a protein-binding monomer to conjugate lectin, which binds sialic acids. It was shown that these lectin-tagged nanoparticles that specifically target sialic acids could track the changes in the expression levels of sialic acids caused by influenza viral infections in human lung epithelial cells. There was a sudden drop in the levels of sialic acid at the initial onset of virus infection (t = 0~1 hr and at approximately 4~5 hrs post-infection. The latter drop correlated with the production of viral proteins that was confirmed using traditional techniques. Thus, the accuracy, the rapidity and the efficacy of the nanoprobes were demonstrated. Such molecular bioimaging tools, which allow easy-handling and in situ monitoring, would be useful to directly observe and decipher the viral infection mechanisms.

  10. Innovations in host and microbial sialic acid biosynthesis revealed by phylogenomic prediction of nonulosonic acid structure.

    Science.gov (United States)

    Lewis, Amanda L; Desa, Nolan; Hansen, Elizabeth E; Knirel, Yuriy A; Gordon, Jeffrey I; Gagneux, Pascal; Nizet, Victor; Varki, Ajit

    2009-08-11

    Sialic acids (Sias) are nonulosonic acid (NulO) sugars prominently displayed on vertebrate cells and occasionally mimicked by bacterial pathogens using homologous biosynthetic pathways. It has been suggested that Sias were an animal innovation and later emerged in pathogens by convergent evolution or horizontal gene transfer. To better illuminate the evolutionary processes underlying the phenomenon of Sia molecular mimicry, we performed phylogenomic analyses of biosynthetic pathways for Sias and related higher sugars derived from 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids. Examination of approximately 1,000 sequenced microbial genomes indicated that such biosynthetic pathways are far more widely distributed than previously realized. Phylogenetic analysis, validated by targeted biochemistry, was used to predict NulO types (i.e., neuraminic, legionaminic, or pseudaminic acids) expressed by various organisms. This approach uncovered previously unreported occurrences of Sia pathways in pathogenic and symbiotic bacteria and identified at least one instance in which a human archaeal symbiont tentatively reported to express Sias in fact expressed the related pseudaminic acid structure. Evaluation of targeted phylogenies and protein domain organization revealed that the "unique" Sia biosynthetic pathway of animals was instead a much more ancient innovation. Pathway phylogenies suggest that bacterial pathogens may have acquired Sia expression via adaptation of pathways for legionaminic acid biosynthesis, one of at least 3 evolutionary paths for de novo Sia synthesis. Together, these data indicate that some of the long-standing paradigms in Sia biology should be reconsidered in a wider evolutionary context of the extended family of NulO sugars.

  11. The role of functionally defective rare germline variants of sialic acid acetylesterase in autoimmune Addison's disease

    Science.gov (United States)

    Gan, Earn H; MacArthur, Katie; Mitchell, Anna L; Pearce, Simon H S

    2012-01-01

    Background Autoimmune Addison's disease (AAD) is a rare condition with a complex genetic basis. A panel of rare and functionally defective genetic variants in the sialic acid acetylesterase (SIAE) gene has recently been implicated in several common autoimmune conditions. We performed a case–control study to determine whether these rare variants are associated with a rarer condition, AAD. Method We analysed nine SIAE gene variants (W48X, M89V, C196F, C226G, R230W, T312M, Y349C, F404S and R479C) in a United Kingdom cohort of 378 AAD subjects and 387 healthy controls. All samples were genotyped using Sequenom iPlex chemistry to characterise primer extension products. Results A heterozygous rare allele at codon 312 (312*M) was found in one AAD patient (0.13%) but was not detected in the healthy controls. The commoner, functionally recessive variant at codon 89 (89*V) was found to be homozygous in two AAD patients but was only found in the heterozygous state in controls. Taking into account all nine alleles examined, 4/378 (1.06%) AAD patients and 1/387 (0.25%) healthy controls carried the defective SIAE alleles, with a calculated odds ratio of 4.13 (95% CI 0.44–97.45, two-tailed P value 0.212, NS). Conclusion We demonstrated the presence of 89*V homozygotes and the 312*M rare allele in the AAD cohort, but overall, our analysis does not support a role for rare variants in SIAE in the pathogenesis of AAD. However, the relatively small collection of AAD patients limits the power to exclude a small effect. PMID:23011869

  12. Identification and biochemical characterization of two functional CMP-sialic acid synthetases in Danio rerio.

    Science.gov (United States)

    Schaper, Wiebke; Bentrop, Joachim; Ustinova, Jana; Blume, Linda; Kats, Elina; Tiralongo, Joe; Weinhold, Birgit; Bastmeyer, Martin; Münster-Kühnel, Anja-K

    2012-04-13

    Sialic acids (Sia) form the nonreducing end of the bulk of cell surface-expressed glycoconjugates. They are, therefore, major elements in intercellular communication processes. The addition of Sia to glycoconjugates requires metabolic activation to CMP-Sia, catalyzed by CMP-Sia synthetase (CMAS). This highly conserved enzyme is located in the cell nucleus in all vertebrates investigated to date, but its nuclear function remains elusive. Here, we describe the identification and characterization of two Cmas enzymes in Danio rerio (dreCmas), one of which is exclusively localized in the cytosol. We show that the two cmas genes most likely originated from the third whole genome duplication, which occurred at the base of teleost radiation. cmas paralogues were maintained in fishes of the Otocephala clade, whereas one copy got subsequently lost in Euteleostei (e.g. rainbow trout). In zebrafish, the two genes exhibited a distinct spatial expression pattern. The products of these genes (dreCmas1 and dreCmas2) diverged not only with respect to subcellular localization but also in substrate specificity. Nuclear dreCmas1 favored N-acetylneuraminic acid, whereas the cytosolic dreCmas2 showed highest affinity for 5-deamino-neuraminic acid. The subcellular localization was confirmed for the endogenous enzymes in fractionated zebrafish lysates. Nuclear entry of dreCmas1 was mediated by a bipartite nuclear localization signal, which seemed irrelevant for other enzymatic functions. With the current demonstration that in zebrafish two subfunctionalized cmas paralogues co-exist, we introduce a novel and unique model to detail the roles that CMAS has in the nucleus and in the sialylation pathways of animal cells.

  13. Diverse subcellular localizations of the insect CMP-sialic acid synthetases.

    Science.gov (United States)

    Di, Wu; Fujita, Akiko; Hamaguchi, Kayo; Delannoy, Philippe; Sato, Chihiro; Kitajima, Ken

    2017-04-01

    The occurrence and biological importance of sialic acid (Sia) and its metabolic enzymes in insects have been studied using Drosophila melanogaster. The most prominent feature of D. melanogaster CMP-Sia synthetase (DmCSS) is its Golgi-localization, contrasted with nuclear localization of vertebrate CSSs. However, it remains unclear if the Golgi-localization is common to other insect CSSs and why it happens. To answer these questions, Aedes aegypti (mosquito) CSS (AaCSS) and Tribolium castaneum (beetle) CSS (TcCSS) were cloned and characterized for their activity and subcellular localization. Our new findings show: (1) AaCSS and TcCSS share a common overall structure with DmCSS in terms of evolutionarily conserved motifs and the absence of the C-terminal domain typical to vertebrate CSSs; (2) when expressed in mammalian and insect cells, AaCSS and TcCSS showed in vivo and in vitro CSS activities, similar to DmCSS. In contrast, when expressed in bacteria, they lacked CSS activity because the N-terminal hydrophobic region appeared to induce protein aggregation; (3) when expressed in Drosophila S2 cells, AaCSS and TcCSS were predominantly localized in the ER, but not in the Golgi. Surprisingly, DmCSS was mainly secreted into the culture medium, although partially detected in Golgi. Consistent with these results, the N-terminal hydrophobic regions of AaCSS and TcCSS functioned as a signal peptide to render them soluble in the ER, while the N-terminus of DmCSS functioned as a membrane-spanning region of type II transmembrane proteins whose cytosolic KLK sequence functioned as an ER export signal. Accordingly, the differential subcellular localization of insect CSSs are distinctively more diverse than previously recognized. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Sialic Acids on Varicella-Zoster Virus Glycoprotein B Are Required for Cell-Cell Fusion.

    Science.gov (United States)

    Suenaga, Tadahiro; Matsumoto, Maki; Arisawa, Fuminori; Kohyama, Masako; Hirayasu, Kouyuki; Mori, Yasuko; Arase, Hisashi

    2015-08-07

    Varicella-zoster virus (VZV) is a member of the human Herpesvirus family that causes varicella (chicken pox) and zoster (shingles). VZV latently infects sensory ganglia and is also responsible for encephalomyelitis. Myelin-associated glycoprotein (MAG), a member of the sialic acid (SA)-binding immunoglobulin-like lectin family, is mainly expressed in neural tissues. VZV glycoprotein B (gB) associates with MAG and mediates membrane fusion during VZV entry into host cells. The SA requirements of MAG when associating with its ligands vary depending on the specific ligand, but it is unclear whether the SAs on gB are involved in the association with MAG. In this study, we found that SAs on gB are essential for the association with MAG as well as for membrane fusion during VZV infection. MAG with a point mutation in the SA-binding site did not bind to gB and did not mediate cell-cell fusion or VZV entry. Cell-cell fusion and VZV entry mediated by the gB-MAG interaction were blocked by sialidase treatment. N-glycosylation or O-glycosylation inhibitors also inhibited the fusion and entry mediated by gB-MAG interaction. Furthermore, gB with mutations in N-glycosylation sites, i.e. asparagine residues 557 and 686, did not associate with MAG, and the cell-cell fusion efficiency was low. Fusion between the viral envelope and cellular membrane is essential for host cell entry by herpesviruses. Therefore, these results suggest that SAs on gB play important roles in MAG-mediated VZV infection. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Polysaccharide capsule and sialic acid-mediated regulation promote biofilm-like intracellular bacterial communities during cystitis.

    Science.gov (United States)

    Anderson, Gregory G; Goller, Carlos C; Justice, Sheryl; Hultgren, Scott J; Seed, Patrick C

    2010-03-01

    Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs). A murine UTI model has revealed an infection cascade whereby UPEC undergoes cycles of invasion of the bladder epithelium, intracellular proliferation in polysaccharide-containing biofilm-like masses called intracellular bacterial communities (IBC), and then dispersal into the bladder lumen to initiate further rounds of epithelial colonization and invasion. We predicted that the UPEC K1 polysaccharide capsule is a key constituent of the IBC matrix. Compared to prototypic E. coli K1 strain UTI89, a capsule assembly mutant had a fitness defect in functionally TLR4(+) and TLR4(-) mice, suggesting a protective role of capsule in inflamed and noninflamed hosts. K1 capsule assembly and synthesis mutants had dramatically reduced IBC formation, demonstrating the common requirement for K1 polysaccharide in IBC development. The capsule assembly mutant appeared dispersed in the cytoplasm of the bladder epithelial cells and failed to undergo high-density intracellular replication during later stages of infection, when the wild-type strain continued to form serial generations of IBC. Deletion of the sialic acid regulator gene nanR partially restored IBC formation in the capsule assembly mutant. These data suggest that capsule is necessary for efficient IBC formation and that aberrant sialic acid accumulation, resulting from disruption of K1 capsule assembly, produces a NanR-mediated defect in intracellular proliferation and IBC development. Together, these data demonstrate the complex but important roles of UPEC polysaccharide encapsulation and sialic acid signaling in multiple stages of UTI pathogenesis.

  16. Sialic Acids in the Brain: Gangliosides and Polysialic Acid in Nervous System Development, Stability, Disease, and Regeneration

    Science.gov (United States)

    Gerardy-Schahn, Rita; Hildebrandt, Herbert

    2014-01-01

    Every cell in nature carries a rich surface coat of glycans, its glycocalyx, which constitutes the cell's interface with its environment. In eukaryotes, the glycocalyx is composed of glycolipids, glycoproteins, and proteoglycans, the compositions of which vary among different tissues and cell types. Many of the linear and branched glycans on cell surface glycoproteins and glycolipids of vertebrates are terminated with sialic acids, nine-carbon sugars with a carboxylic acid, a glycerol side-chain, and an N-acyl group that, along with their display at the outmost end of cell surface glycans, provide for varied molecular interactions. Among their functions, sialic acids regulate cell-cell interactions, modulate the activities of their glycoprotein and glycolipid scaffolds as well as other cell surface molecules, and are receptors for pathogens and toxins. In the brain, two families of sialoglycans are of particular interest: gangliosides and polysialic acid. Gangliosides, sialylated glycosphingolipids, are the most abundant sialoglycans of nerve cells. Mouse genetic studies and human disorders of ganglioside metabolism implicate gangliosides in axon-myelin interactions, axon stability, axon regeneration, and the modulation of nerve cell excitability. Polysialic acid is a unique homopolymer that reaches >90 sialic acid residues attached to select glycoproteins, especially the neural cell adhesion molecule in the brain. Molecular, cellular, and genetic studies implicate polysialic acid in the control of cell-cell and cell-matrix interactions, intermolecular interactions at cell surfaces, and interactions with other molecules in the cellular environment. Polysialic acid is essential for appropriate brain development, and polymorphisms in the human genes responsible for polysialic acid biosynthesis are associated with psychiatric disorders including schizophrenia, autism, and bipolar disorder. Polysialic acid also appears to play a role in adult brain plasticity

  17. Sialic acids regulate microvessel permeability, revealed by novel in vivo studies of endothelial glycocalyx structure and function

    Science.gov (United States)

    Betteridge, Kai B.; Arkill, Kenton P.; Neal, Christopher R.; Harper, Steven J.; Foster, Rebecca R.; Satchell, Simon C.; Bates, David O.

    2017-01-01

    Key points We have developed novel techniques for paired, direct, real‐time in vivo quantification of endothelial glycocalyx structure and associated microvessel permeability.Commonly used imaging and analysis techniques yield measurements of endothelial glycocalyx depth that vary by over an order of magnitude within the same vessel.The anatomical distance between maximal glycocalyx label and maximal endothelial cell plasma membrane label provides the most sensitive and reliable measure of endothelial glycocalyx depth.Sialic acid residues of the endothelial glycocalyx regulate glycocalyx structure and microvessel permeability to both water and albumin. Abstract The endothelial glycocalyx forms a continuous coat over the luminal surface of all vessels, and regulates multiple vascular functions. The contribution of individual components of the endothelial glycocalyx to one critical vascular function, microvascular permeability, remains unclear. We developed novel, real‐time, paired methodologies to study the contribution of sialic acids within the endothelial glycocalyx to the structural and functional permeability properties of the same microvessel in vivo. Single perfused rat mesenteric microvessels were perfused with fluorescent endothelial cell membrane and glycocalyx labels, and imaged with confocal microscopy. A broad range of glycocalyx depth measurements (0.17–3.02 μm) were obtained with different labels, imaging techniques and analysis methods. The distance between peak cell membrane and peak glycocalyx label provided the most reliable measure of endothelial glycocalyx anatomy, correlating with paired, numerically smaller values of endothelial glycocalyx depth (0.078 ± 0.016 μm) from electron micrographs of the same portion of the same vessel. Disruption of sialic acid residues within the endothelial glycocalyx using neuraminidase perfusion decreased endothelial glycocalyx depth and increased apparent solute permeability to albumin in the same

  18. Tethering of Ficolin-1 to cell surfaces through recognition of sialic acid by the fibrinogen-like domain

    DEFF Research Database (Denmark)

    Honore, C.; Rorvig, S.; Hummelshoj, T.

    2010-01-01

    domain, and no binding partners have been identified. To gain further insight in the physiological role of Ficolin-1, we sought to identify the molecular mechanism responsible for the membrane association of Ficolin-1 to monocytes and granulocytes. We demonstrate that expression of Ficolin-1 on the cell...... surface is restricted to monocytes and granulocytes. Ficolin-1 is tethered to the cell surface of these cells through its fibrinogen-like domain, and the ligand involved in the binding of Ficolin-1 is shown to be sialic acid. Moreover, rFicolin-1 bound activated but not resting T lymphocytes. Together...

  19. The random co-polymer glatiramer acetate rapidly kills primary human leukocytes through sialic-acid-dependent cell membrane damage

    DEFF Research Database (Denmark)

    Christiansen, Stig Hill; Zhang, Xianwei; Juul-Madsen, Kristian

    2017-01-01

    in innate immunity. It shares the positive charge and amphipathic character of GA, and, as shown here, also the ability to kill human leukocyte. The cytotoxicity of both compounds depends on sialic acid in the cell membrane. The killing was associated with the generation of CD45 + debris, derived from cell...... membrane deformation. Nanoparticle tracking analysis confirmed the formation of such debris, even at low GA concentrations. Electric cell-substrate impedance sensing measurements also recorded stable alterations in T lymphocytes following such treatment. LL-37 forms oligomers through weak hydrophobic...

  20. Bayesian Alternation During Tactile Augmentation

    Directory of Open Access Journals (Sweden)

    Caspar Mathias Goeke

    2016-10-01

    Full Text Available A large number of studies suggest that the integration of multisensory signals by humans is well described by Bayesian principles. However, there are very few reports about cue combination between a native and an augmented sense. In particular, we asked the question whether adult participants are able to integrate an augmented sensory cue with existing native sensory information. Hence for the purpose of this study we build a tactile augmentation device. Consequently, we compared different hypotheses of how untrained adult participants combine information from a native and an augmented sense. In a two-interval forced choice (2 IFC task, while subjects were blindfolded and seated on a rotating platform, our sensory augmentation device translated information on whole body yaw rotation to tactile stimulation. Three conditions were realized: tactile stimulation only (augmented condition, rotation only (native condition, and both augmented and native information (bimodal condition. Participants had to choose one out of two consecutive rotations with higher angular rotation. For the analysis, we fitted the participants’ responses with a probit model and calculated the just notable difference (JND. Then we compared several models for predicting bimodal from unimodal responses. An objective Bayesian alternation model yielded a better prediction (χred2 = 1.67 than the Bayesian integration model (χred2= 4.34. Slightly higher accuracy showed a non-Bayesian winner takes all model (χred2= 1.64, which either used only native or only augmented values per subject for prediction. However the performance of the Bayesian alternation model could be substantially improved (χred2= 1.09 utilizing subjective weights obtained by a questionnaire. As a result, the subjective Bayesian alternation model predicted bimodal performance most accurately among all tested models. These results suggest that information from augmented and existing sensory modalities in

  1. Comprehensible visualization for augmented reality.

    Science.gov (United States)

    Kalkofen, Denis; Mendez, Erick; Schmalstieg, Dieter

    2009-01-01

    This article presents interactive visualizations to support the comprehension of spatial relationships between virtual and real world objects for Augmented Reality (AR) applications. To enhance the clarity of such relationships we discuss visualization techniques and their suitability for AR. We apply them on different AR applications with different goals, e.g. in X-Ray vision or in applications which draw a user's attention to an object of interest. We demonstrate how Focus and Context (F+C) visualizations are used to affect the user's perception of hidden or nearby objects by presenting contextual information in the area of augmentation. We discuss the organization and the possible sources of data for visualizations in Augmented Reality and present cascaded and multi level F+C visualizations to address complex, cluttered scenes that are inevitable in real environments. This article also shows filters and tools to interactively control the amount of augmentation. It compares the impact of real world context preserving to a pure virtual and uniform enhancement of these structures for augmentations of real world imagery. Finally this paper discusses the stylization of sparse object representations for AR to improve X-Ray vision.

  2. Augmented reality for breast imaging.

    Science.gov (United States)

    Rancati, Alberto; Angrigiani, Claudio; Nava, Maurizio B; Catanuto, Giuseppe; Rocco, Nicola; Ventrice, Fernando; Dorr, Julio

    2018-02-21

    Augmented reality (AR) enables the superimposition of virtual reality reconstructions onto clinical images of a real patient, in real time. This allows visualization of internal structures through overlying tissues, thereby providing a virtual transparency vision of surgical anatomy. AR has been applied to neurosurgery, which utilizes a relatively fixed space, frames, and bony references; the application of AR facilitates the relationship between virtual and real data. Augmented Breast imaging (ABI) is described. Breast MRI studies for breast implant patients with seroma were performed using a Siemens 3T system with a body coil and a four-channel bilateral phased-array breast coil as the transmitter and receiver, respectively. The contrast agent used was (CA) gadolinium (Gd) injection (0.1 mmol/kg at 2 ml/s) by a programmable power injector. Dicom formated images data from 10 MRI cases of breast implant seroma and 10 MRI cases with T1-2 N0 M0 breast cancer, were imported and transformed into Augmented reality images. Augmented breast imaging (ABI) demonstrated stereoscopic depth perception, focal point convergence, 3D cursor use, and joystick fly-through. Augmented breast imaging (ABI) to the breast can improve clinical outcomes, giving an enhanced view of the structures to work on. It should be further studied to determine its utility in clinical practice.

  3. Augmented Reality Tower Technology Assessment

    Science.gov (United States)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  4. Augmented reality som wearable technology

    DEFF Research Database (Denmark)

    Rahn, Annette

    2016-01-01

    “How Augmented reality can facilitate learning in visualizing human anatomy “ At this station I demonstrate how Augmented reality can be used to visualize the human lungs in situ and as a wearable technology which establish connection between body, image and technology in education. I will show...... the potential of Augmented reality increasing students level of understanding, interaction and engagement with the object. I will demonstrate the technology and show you the human lungs in your body and the future perspectives of the technology. Organization: developed in collaboration with Mie Buhl, Professor...... MSO, Aalborg University, Copenhagen. Annette Rahn, MSc, senior lecturer and teacher in anatomy and physiology at the School of Nursing, VIA Health- and Welfare Technology, VIA University College....

  5. One-pot SSA-catalyzed β-elimination: An efficient and inexpensive protocol for easy access to the glycal of sialic acid

    OpenAIRE

    Paragas, Erickson M.; Monreal, I. Abrrey; Vasil, Chris M.; Saludes, Jonel P.

    2014-01-01

    Neu5Ac2en1Me per-OAc, the fully protected glycal of sialic acid, is a key intermediate in the discovery of therapeutics and diagnostics, including anti-influenza drugs and proteolysis resistant peptidomimetic foldamers. The synthesis of this sialic acid derivative, however, still relies on standard sugar chemistry that utilizes multi-step methodologies. Herein we report a facile and highly efficient microwave-assisted preparation of Neu5Ac1Me using silica sulfuric acid (SSA) as solid-supporte...

  6. Augmentation-related brain plasticity

    Science.gov (United States)

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

  7. AUGMENTATION-RELATED BRAIN PLASTICITY

    Directory of Open Access Journals (Sweden)

    Giovanni eDi Pino

    2014-06-01

    Full Text Available Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyzes the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain.Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools.Augmentation modifies function and structure of a number of areas, i.e. primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the

  8. Augmented reality for anatomical education.

    Science.gov (United States)

    Thomas, Rhys Gethin; John, Nigel William; Delieu, John Michael

    2010-03-01

    The use of Virtual Environments has been widely reported as a method of teaching anatomy. Generally such environments only convey the shape of the anatomy to the student. We present the Bangor Augmented Reality Education Tool for Anatomy (BARETA), a system that combines Augmented Reality (AR) technology with models produced using Rapid Prototyping (RP) technology, to provide the student with stimulation for touch as well as sight. The principal aims of this work were to provide an interface more intuitive than a mouse and keyboard, and to evaluate such a system as a viable supplement to traditional cadaver based education.

  9. Augmented Reality in Science Education

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Swenson, Hakon

    Augmented reality (AR) holds great promise as a learning tool. However, most extant studies in this field have focused on the technology itself. The poster presents findings from the first stage of the AR-sci project addressing the issue of applying AR for educational purposes. Benefits and chall......Augmented reality (AR) holds great promise as a learning tool. However, most extant studies in this field have focused on the technology itself. The poster presents findings from the first stage of the AR-sci project addressing the issue of applying AR for educational purposes. Benefits...

  10. Harnessing cancer cell metabolism for theranostic applications using metabolic glycoengineering of sialic acid in breast cancer as a pioneering example.

    Science.gov (United States)

    Badr, Haitham A; AlSadek, Dina M M; El-Houseini, Motawa E; Saeui, Christopher T; Mathew, Mohit P; Yarema, Kevin J; Ahmed, Hafiz

    2017-02-01

    Abnormal cell surface display of sialic acids - a family of unusual 9-carbon sugars - is widely recognized as distinguishing feature of many types of cancer. Sialoglycans, however, typically cannot be identified with sufficiently high reproducibility and sensitivity to serve as clinically accepted biomarkers and similarly, almost all efforts to exploit cancer-specific differences in sialylation signatures for therapy remain in early stage development. In this report we provide an overview of important facets of glycosylation that contribute to cancer in general with a focus on breast cancer as an example of malignant disease characterized by aberrant sialylation. We then describe how cancer cells experience nutrient deprivation during oncogenesis and discuss how the resulting metabolic reprogramming, which endows breast cancer cells with the ability to obtain nutrients during scarcity, constitutes an "Achilles' heel" that we believe can be exploited by metabolic glycoengineering (MGE) strategies to develop new diagnostic methods and therapeutic approaches. In particular, we hypothesize that adaptations made by breast cancer cells that allow them to efficiently scavenge sialic acid during times of nutrient deprivation renders them vulnerable to MGE, which refers to the use of exogenously-supplied, non-natural monosaccharide analogues to modulate targeted aspects of glycosylation in living cells and animals. In specific, once non-natural sialosides are incorporated into the cancer "sialome" they can be exploited as epitopes for immunotherapy or as chemical tags for targeted delivery of imaging or therapeutic agents selectively to tumors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Expression and localization of MCsialec, a sialic acid-specific lectin in the marine bivalve Manila clam, Ruditapes philppinarum.

    Science.gov (United States)

    Adhya, M; Choi, K-S; Yu, Y; Cho, M

    2010-11-01

    A novel sialic acid-specific lectin (MCsialec) was detected from an expressed sequenced tag (EST) sequence from Manila clam haemocytes infected with Perkinsus olseni. The cDNA of the lectin was cloned using gene-specific primers based on a previously determined EST and characterized. The full-length cDNA of MCsialec is 603 bp in length and encodes a polypeptide of 200 amino acids with a calculated molecular mass of 21.928 kDa. Sequence alignment and protein motif analyses showed that MCsialec shares identity with sialic acid-specific invertebrate lectins from Cepaea hortensis, Helix pomatia and Haliotis discus discus. The lectin was expressed in Escherichia coli M15 cells and purified using a Ni-NTA His-binding resin matrix for antibody production. The presence of the lectin in various tissues of Perkinsus-infected and uninfected Manila clams was analysed by both PCR and immunohistochemical localization assays. MCsialec was detected in each tissue of the clams; however, upon infection, the level of expression of the lectin increased in each tissue. Vibrio tapetis infection also induced high-level expression of MCsialec in the haemocytes. These data suggest that MCsialec plays a crucial role in the immune system of the Manila clam during pathogenic infection. © 2010 Blackwell Publishing Ltd.

  12. Increased excretion of two sialic acid-containing trisaccharides in the urine of patients with rheumatoid arthritis.

    Science.gov (United States)

    Maury, P

    1978-12-01

    The urinary excretion of sialic acid-containing trisaccharides in patients with active rheumatoid arthritis was studied. Sialyl-lactose and sialyl-N-acetyllactosamine were identified and their excretion patterns studied by thin layer and gas chromatography. The urinary output of sialyl-lactose was greater in patients with active rheumatoid arthritis (48.2 +/- 6.1 mg/24 h, SEM, n = 6) than in healthy subjects (19.8 +/- 3.7 mg/24 h, SEM, n = 5; P less than 0.01). The excretion of sialyl-N-acetyllactosamine was also higher in the rheumatoid group (18.5 +/- 2.1 mg/24 h, SEM, n = 6) than in the controls (11.1 +/- 1.2 mg/24 h, SEM, n = 5; P less than 0.05). The qualitative excretion patterns of the sialyl-oligosaccharide fraction were similar for the two groups as judged from the thin layer chromatograms. Correlating the results with the clinical state of the patients with rheumatoid arthritis suggests that the urinary level of the sialyl-oligosaccharides reflects the activity of the disease. A proposed mechanism for the increased excretion of sialic acid-containing trisaccharides in rheumatoid arthritis is presented.

  13. Distribution of sialic acid receptors and influenza A viruses of avian and swine origin and in experimentally infected pigs

    DEFF Research Database (Denmark)

    Trebbien, Ramona; Larsen, Lars Erik; Viuff, Birgitte M.

    2011-01-01

    Background: Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SAalpha- 2,3)) and swine/human (SA-alpha-2,6) influenza viruses in the up......Background: Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SAalpha- 2,3)) and swine/human (SA-alpha-2,6) influenza viruses...... and AIV virus was found, and this difference was in accordance with the distribution of the SA-alpha-2,6 and SA-alpha-2,3 receptor, respectively. The results indicated that the distribution of influenza A virus receptors in pigs are similar to that of humans and therefore challenge the theory that the pig...

  14. Salmonella O48 Serum Resistance is Connected with the Elongation of the Lipopolysaccharide O-Antigen Containing Sialic Acid

    Directory of Open Access Journals (Sweden)

    Aleksandra Pawlak

    2017-09-01

    Full Text Available Complement is one of the most important parts of the innate immune system. Some bacteria can gain resistance against the bactericidal action of complement by decorating their outer cell surface with lipopolysaccharides (LPSs containing a very long O-antigen or with specific outer membrane proteins. Additionally, the presence of sialic acid in the LPS molecules can provide a level of protection for bacteria, likening them to human cells, a phenomenon known as molecular mimicry. Salmonella O48, which contains sialic acid in the O-antigen, is the major cause of reptile-associated salmonellosis, a worldwide public health problem. In this study, we tested the effect of prolonged exposure to human serum on strains from Salmonella serogroup O48, specifically on the O-antigen length. After multiple passages in serum, three out of four tested strains became resistant to serum action. The gas-liquid chromatography/tandem mass spectrometry analysis showed that, for most of the strains, the average length of the LPS O-antigen increased. Thus, we have discovered a link between the resistance of bacterial cells to serum and the elongation of the LPS O-antigen.

  15. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne

    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student i...

  16. Augmented Reality in Science Education

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Swensen, Hakon

    Augmented reality (AR) holds great promise as a learning tool. However, most extant studies in this field have focused on the technology itself. The poster presents findings from the first stage of the AR-sci project addressing the issue of applying AR for educational purposes. Benefits...

  17. Inhibition of basophil histamine release by gangliosides. Further studies on the significance of cell membrane sialic acid in the histamine release process

    DEFF Research Database (Denmark)

    Jensen, C; Norn, S; Thastrup, Ole

    1987-01-01

    Histamine release from human basophils was inhibited by preincubation of the cells with a glucolipid mixture containing sialic acid-containing gangliosides. This was true for histamine release induced by anti-IgE, Concanavalin A and the calcium ionophore A23187, whereas the release induced by S. ...

  18. Enzymatic Decoration of Prebiotic Galacto-oligosaccharides (Vivinal® GOS) with Sialic Acid using Trypanosoma cruzi Trans-Sialidase and Two Bovine Sialoglycoconjugates as Donor Substrates

    NARCIS (Netherlands)

    Wilbrink, Maarten Hotse; Ten Kate, Geert Albert; Sanders, Peter; Gerwig, Gerrit J; van Leeuwen, Sander S; Sallomons, Erik; Klarenbeek, Bert; Hage, Johannes H; van Vuure, Carine A; Dijkhuizen, Lubbert; Kamerling, Johannis P

    2015-01-01

    Decoration of prebiotic galacto-oligosaccharides (GOS) with sialic acid yields mixtures of GOS and sialylated GOS (Sia-GOS), novel products that are expected to have both prebiotic and anti-adhesive functionalities. The recombinantly produced trans-sialidase enzyme from Trypanosoma cruzi (TcTS), an

  19. Augmented assessment as a means to augmented reality.

    Science.gov (United States)

    Bergeron, Bryan

    2006-01-01

    Rigorous scientific assessment of educational technologies typically lags behind the availability of the technologies by years because of the lack of validated instruments and benchmarks. Even when the appropriate assessment instruments are available, they may not be applied because of time and monetary constraints. Work in augmented reality, instrumented mannequins, serious gaming, and similar promising educational technologies that haven't undergone timely, rigorous evaluation, highlights the need for assessment methodologies that address the limitations of traditional approaches. The most promising augmented assessment solutions incorporate elements of rapid prototyping used in the software industry, simulation-based assessment techniques modeled after methods used in bioinformatics, and object-oriented analysis methods borrowed from object oriented programming.

  20. Use of Augmented Reality in Education

    OpenAIRE

    Jeřábek, Tomáš

    2014-01-01

    This thesis deals with phenomena of augmented reality in context of didactics. The thesis aims to define augmented reality in conceptual and content area and focuses on augmented reality in the structure of educational tools and identification of its functions and use from the didactical standpoint. The thesis characterizes augmented reality as a specific technological-perceptual concept and establishes a system of perceptual, technological and resulting aspects that reflect important paramet...

  1. Augmented Reality for Multi-disciplinary Collaboration

    OpenAIRE

    Wang, Xiangyu; Rui,

    2010-01-01

    This chapter presents a framework for multi-disciplinary collaboration. Tangible Augmented Reality has been raised as one of suitable systems for design collaboration. Furthermore, it emphasizes the advantages of Tangible Augmented Reality to illustrate the needs for integrating the Tangible User Interfaces and Augmented Reality Systems.

  2. Ridge augmentation in implant dentistry

    Directory of Open Access Journals (Sweden)

    Manoj Goyal

    2015-01-01

    Full Text Available Dimensional changes in the alveolar ridge after extraction often compromises on achieving optimal implant stability and placement of implants in the right prosthodontic positions. These situations demand augmentation of the residual ridge to achieve successful implant placement and long-term survival. Although the available literature speaks of an overabundance of techniques and agents for ridge augmentation, there is a relative paucity of quality evidence to guide the selection of suitable techniques and material. Henceforth, this paper is an endeavor to develop and describe an evidence-based decision pathway for the selection of suitable techniques for various clinical situations. Additionally, a descriptive overview of various techniques and materials is presented.

  3. Augmented reality building operations tool

    Science.gov (United States)

    Brackney, Larry J.

    2014-09-09

    A method (700) for providing an augmented reality operations tool to a mobile client (642) positioned in a building (604). The method (700) includes, with a server (660), receiving (720) from the client (642) an augmented reality request for building system equipment (612) managed by an energy management system (EMS) (620). The method (700) includes transmitting (740) a data request for the equipment (612) to the EMS (620) and receiving (750) building management data (634) for the equipment (612). The method (700) includes generating (760) an overlay (656) with an object created based on the building management data (634), which may be sensor data, diagnostic procedures, or the like. The overlay (656) is configured for concurrent display on a display screen (652) of the client (642) with a real-time image of the building equipment (612). The method (700) includes transmitting (770) the overlay (656) to the client (642).

  4. Digital Illumination for Augmented Studios

    OpenAIRE

    Bimber, Oliver; Grundhöfer, Anselm; Zollmann, Stefanie; Kolster, Daniel

    2006-01-01

    Virtual studio technology plays an important role for modern television productions. Blue-screen matting is a common technique for integrating real actors or moderators into computer generated sceneries. Augmented reality offers the possibility to mix real and virtual in a more general context. This article proposes a new technological approach for combining real studio content with computergenerated information. Digital light projection allows a controlled spatial, temporal, chrominance a...

  5. Media-Augmented Exercise Machines

    Science.gov (United States)

    Krueger, T.

    2002-01-01

    Cardio-vascular exercise has been used to mitigate the muscle and cardiac atrophy associated with adaptation to micro-gravity environments. Several hours per day may be required. In confined spaces and long duration missions this kind of exercise is inevitably repetitive and rapidly becomes uninteresting. At the same time, there are pressures to accomplish as much as possible given the cost- per-hour for humans occupying orbiting or interplanetary. Media augmentation provides a the means to overlap activities in time by supplementing the exercise with social, recreational, training or collaborative activities and thereby reducing time pressures. In addition, the machine functions as an interface to a wide range of digital environments allowing for spatial variety in an otherwise confined environment. We hypothesize that the adoption of media augmented exercise machines will have a positive effect on psycho-social well-being on long duration missions. By organizing and supplementing exercise machines, data acquisition hardware, computers and displays into an interacting system this proposal increases functionality with limited additional mass. This paper reviews preliminary work on a project to augment exercise equipment in a manner that addresses these issues and at the same time opens possibilities for additional benefits. A testbed augmented exercise machine uses a specialty built cycle trainer as both input to a virtual environment and as an output device from it using spatialized sound, and visual displays, vibration transducers and variable resistance. The resulting interactivity increases a sense of engagement in the exercise, provides a rich experience of the digital environments. Activities in the virtual environment and accompanying physiological and psychological indicators may be correlated to track and evaluate the health of the crew.

  6. Real-time augmented face

    OpenAIRE

    Lepetit, V.; Vacchetti, L; Thalmann, D; Fua, P.

    2003-01-01

    This real-time augmented reality demonstration relies on our tracking algorithm described in V. Lepetit et al (2003). This algorithm considers natural feature points, and then does not require engineering of the environment. It merges the information from preceding frames in traditional recursive tracking fashion with that provided by a very limited number of reference frames. This combination results in a system that does not suffer from jitter and drift, and can deal with drastic changes. T...

  7. Sialic acid transport and catabolism are cooperatively regulated by SiaR and CRP in nontypeable Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Johnston Jason W

    2010-09-01

    Full Text Available Abstract Background The transport and catabolism of sialic acid, a critical virulence factor for nontypeable Haemophilus influenzae, is regulated by two transcription factors, SiaR and CRP. Results Using a mutagenesis approach, glucosamine-6-phosphate (GlcN-6P was identified as a co-activator for SiaR. Evidence for the cooperative regulation of both the sialic acid catabolic and transport operons suggested that cooperativity between SiaR and CRP is required for regulation. cAMP was unable to influence the expression of the catabolic operon in the absence of SiaR but was able to induce catabolic operon expression when both SiaR and GlcN-6P were present. Alteration of helical phasing supported this observation by uncoupling SiaR and CRP regulation. The insertion of one half-turn of DNA between the SiaR and CRP operators resulted in the loss of SiaR-mediated repression of the transport operon while eliminating cAMP-dependent induction of the catabolic operon when GlcN-6P was present. SiaR and CRP were found to bind to their respective operators simultaneously and GlcN-6P altered the interaction of SiaR with its operator. Conclusions These results suggest multiple novel features for the regulation of these two adjacent operons. SiaR functions as both a repressor and an activator and SiaR and CRP interact to regulate both operons from a single set of operators.

  8. Canine and feline parvoviruses preferentially recognize the non-human cell surface sialic acid N-glycolylneuraminic acid

    Energy Technology Data Exchange (ETDEWEB)

    Löfling, Jonas [Departments of Medicine and Cellular and Molecular Medicine, Glycobiology Research and Training Center, Center for Academic Research and Training in Anthropogeny, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093 (United States); Michael Lyi, Sangbom; Parrish, Colin R. [Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (United States); Varki, Ajit, E-mail: a1varki@ucsd.edu [Departments of Medicine and Cellular and Molecular Medicine, Glycobiology Research and Training Center, Center for Academic Research and Training in Anthropogeny, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093 (United States)

    2013-05-25

    Feline panleukopenia virus (FPV) is a pathogen whose canine-adapted form (canine parvovirus (CPV)) emerged in 1978. These viruses infect by binding host transferrin receptor type-1 (TfR), but also hemagglutinate erythrocytes. We show that hemagglutination involves selective recognition of the non-human sialic acid N-glycolylneuraminic acid (Neu5Gc) but not N-acetylneuraminic acid (Neu5Ac), which differs by only one oxygen atom from Neu5Gc. Overexpression of α2-6 sialyltransferase did not change binding, indicating that both α2-3 and α2-6 linkages are recognized. However, Neu5Gc expression on target cells did not enhance CPV or FPV infection in vitro. Thus, the conserved Neu5Gc-binding preference of these viruses likely plays a role in the natural history of the virus in vivo. Further studies must clarify relationships between virus infection and host Neu5Gc expression. As a first step, we show that transcripts of CMAH (which generates Neu5Gc from Neu5Ac) are at very low levels in Western dog breed cells. - Highlights: ► Feline and canine parvoviruses recognize Neu5Gc but not Neu5Ac, which differ by one oxygen atom. ► The underlying linkage of these sialic acids does not affect recognition. ► Induced Neu5Gc expression on target cells that normally express Neu5Ac did not enhance infection. ► Thus, the conserved binding preference plays an important yet unknown role in in vivo infections. ► Population and breed variations in Neu5Gc expression occur, likely by regulating the gene CMAH.

  9. Comparison of backbone dynamics of the type III antifreeze protein and antifreeze-like domain of human sialic acid synthase

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong-Geun [Gyeongsang National University, Department of Chemistry and Research Institute of Natural Science (Korea, Republic of); Park, Chin-Ju [Gwangju Institute of Science and Technology, Division of Liberal Arts and Sciences and Department of Chemistry (Korea, Republic of); Kim, Hee-Eun; Seo, Yeo-Jin; Lee, Ae-Ree; Choi, Seo-Ree; Lee, Shim Sung; Lee, Joon-Hwa, E-mail: joonhwa@gnu.ac.kr [Gyeongsang National University, Department of Chemistry and Research Institute of Natural Science (Korea, Republic of)

    2015-02-15

    Antifreeze proteins (AFPs) are found in a variety of cold-adapted (psychrophilic) organisms to promote survival at subzero temperatures by binding to ice crystals and decreasing the freezing temperature of body fluids. The type III AFPs are small globular proteins that consist of one α-helix, three 3{sub 10}-helices, and two β-strands. Sialic acids play important roles in a variety of biological functions, such as development, recognition, and cell adhesion and are synthesized by conserved enzymatic pathways that include sialic acid synthase (SAS). SAS consists of an N-terminal catalytic domain and a C-terminal antifreeze-like (AFL) domain, which is similar to the type III AFPs. Despite having very similar structures, AFL and the type III AFPs exhibit very different temperature-dependent stability and activity. In this study, we have performed backbone dynamics analyses of a type III AFP (HPLC12 isoform) and the AFL domain of human SAS (hAFL) at various temperatures. We also characterized the structural/dynamic properties of the ice-binding surfaces by analyzing the temperature gradient of the amide proton chemical shift and its correlation with chemical shift deviation from random coil. The dynamic properties of the two proteins were very different from each other. While HPLC12 was mostly rigid with a few residues exhibiting slow motions, hAFL showed fast internal motions at low temperature. Our results provide insight into the molecular basis of thermostability and structural flexibility in homologous psychrophilic HPLC12 and mesophilic hAFL proteins.

  10. Both α2,3- and α2,6-linked sialic acids on O-linked glycoproteins act as functional receptors for porcine Sapovirus.

    Directory of Open Access Journals (Sweden)

    Deok-Song Kim

    2014-06-01

    Full Text Available Sapovirus, a member of the Caliciviridae family, is an important cause of acute gastroenteritis in humans and pigs. Currently, the porcine sapovirus (PSaV Cowden strain remains the only cultivable member of the Sapovirus genus. While some caliciviruses are known to utilize carbohydrate receptors for entry and infection, a functional receptor for sapovirus is unknown. To characterize the functional receptor of the Cowden strain of PSaV, we undertook a comprehensive series of protein-ligand biochemical assays in mock and PSaV-infected cell culture and/or piglet intestinal tissue sections. PSaV revealed neither hemagglutination activity with red blood cells from any species nor binding activity to synthetic histo-blood group antigens, indicating that PSaV does not use histo-blood group antigens as receptors. Attachment and infection of PSaV were markedly blocked by sialic acid and Vibrio cholerae neuraminidase (NA, suggesting a role for α2,3-linked, α2,6-linked or α2,8-linked sialic acid in virus attachment. However, viral attachment and infection were only partially inhibited by treatment of cells with sialidase S (SS or Maackia amurensis lectin (MAL, both specific for α2,3-linked sialic acid, or Sambucus nigra lectin (SNL, specific for α2,6-linked sialic acid. These results indicated that PSaV recognizes both α2,3- and α2,6-linked sialic acids for viral attachment and infection. Treatment of cells with proteases or with benzyl 4-O-β-D-galactopyranosyl-β-D-glucopyranoside (benzylGalNAc, which inhibits O-linked glycosylation, also reduced virus binding and infection, whereas inhibition of glycolipd synthesis or N-linked glycosylation had no such effect on virus binding or infection. These data suggest PSaV binds to cellular receptors that consist of α2,3- and α2,6-linked sialic acids on glycoproteins attached via O-linked glycosylation.

  11. Robotic assisted laparoscopic augmentation ileocystoplasty

    Directory of Open Access Journals (Sweden)

    Peter A. Caputo

    Full Text Available ABSTRACT Introduction: Augmentation ileocystoplasty is a common treatment in adults with low capacity bladders due to neurogenic bladder dysfunction. We describe here our technique for robotic assisted laparoscopic augmentation ileocystoplasty in an adult with a low capacity bladder due to neurogenic bladder dysfunction. Materials and Methods: The patient is a 35 years-old man with neurogenic bladder due to a C6 spinal cord injury in 2004. Cystometrogram shows a maximum capacity of 96cc and Pdet at maximum capacity of 97cmH2O. He manages his bladder with intermittent catheterization and experiences multiple episodes of incontinence between catheterizations. He experiences severe autonomic dysreflexia symptoms with indwelling urethral catheter. He has previously failed non operative management options of his bladder dysfunction. Our surgical technique utilizes 6 trocars, of note a 12mm assistant trocar is placed 1cm superior to the pubic symphysis, and this trocar is solely used to pass a laparoscopic stapler to facilitate the excision of the ileal segment and the enteric anastomosis. Surgical steps include: development of the space of Retzius/dropping the bladder; opening the bladder from the anterior to posterior bladder neck; excision of a segment of ileum; enteric anastomosis; detubularizing the ileal segment; suturing the ileal segment to the incised bladder edge. Results: The surgery had no intraoperative complications. Operative time was 286 minutes (4.8 hours. Estimated blood loss was 50cc. Length of hospital stay was 8 days. He did experience a postoperative complication on hospital day 3 of hematemesis, which did not require blood transfusion. Cystometrogram at 22 days post operatively showed a maximum bladder capacity of 165cc with a Pdet at maximum capacity of 10cmH2O. Conclusions: As surgeon comfort and experience with robotic assisted surgery grows, robotic surgery can successfully be applied to less frequently performed procedures

  12. Webizing mobile augmented reality content

    Science.gov (United States)

    Ahn, Sangchul; Ko, Heedong; Yoo, Byounghyun

    2014-01-01

    This paper presents a content structure for building mobile augmented reality (AR) applications in HTML5 to achieve a clean separation of the mobile AR content and the application logic for scaling as on the Web. We propose that the content structure contains the physical world as well as virtual assets for mobile AR applications as document object model (DOM) elements and that their behaviour and user interactions are controlled through DOM events by representing objects and places with a uniform resource identifier. Our content structure enables mobile AR applications to be seamlessly developed as normal HTML documents under the current Web eco-system.

  13. Augmented reality in intraventricular neuroendoscopy.

    Science.gov (United States)

    Finger, T; Schaumann, A; Schulz, M; Thomale, Ulrich-W

    2017-06-01

    Individual planning of the entry point and the use of navigation has become more relevant in intraventricular neuroendoscopy. Navigated neuroendoscopic solutions are continuously improving. We describe experimentally measured accuracy and our first experience with augmented reality-enhanced navigated neuroendoscopy for intraventricular pathologies. Augmented reality-enhanced navigated endoscopy was tested for accuracy in an experimental setting. Therefore, a 3D-printed head model with a right parietal lesion was scanned with a thin-sliced computer tomography. Segmentation of the tumor lesion was performed using Scopis NovaPlan navigation software. An optical reference matrix is used to register the neuroendoscope's geometry and its field of view. The pre-planned ROI and trajectory are superimposed in the endoscopic image. The accuracy of the superimposed contour fitting on endoscopically visualized lesion was acquired by measuring the deviation of both midpoints to one another. The technique was subsequently used in 29 cases with CSF circulation pathologies. Navigation planning included defining the entry points, regions of interests and trajectories, superimposed as augmented reality on the endoscopic video screen during intervention. Patients were evaluated for postoperative imaging, reoperations, and possible complications. The experimental setup revealed a deviation of the ROI's midpoint from the real target by 1.2 ± 0.4 mm. The clinical study included 18 cyst fenestrations, ten biopsies, seven endoscopic third ventriculostomies, six stent placements, and two shunt implantations, being eventually combined in some patients. In cases of cyst fenestrations postoperatively, the cyst volume was significantly reduced in all patients by mean of 47%. In biopsies, the diagnostic yield was 100%. Reoperations during a follow-up period of 11.4 ± 10.2 months were necessary in two cases. Complications included one postoperative hygroma and one insufficient

  14. Augmented reality in medical education?

    Science.gov (United States)

    Kamphuis, Carolien; Barsom, Esther; Schijven, Marlies; Christoph, Noor

    2014-09-01

    Learning in the medical domain is to a large extent workplace learning and involves mastery of complex skills that require performance up to professional standards in the work environment. Since training in this real-life context is not always possible for reasons of safety, costs, or didactics, alternative ways are needed to achieve clinical excellence. Educational technology and more specifically augmented reality (AR) has the potential to offer a highly realistic situated learning experience supportive of complex medical learning and transfer. AR is a technology that adds virtual content to the physical real world, thereby augmenting the perception of reality. Three examples of dedicated AR learning environments for the medical domain are described. Five types of research questions are identified that may guide empirical research into the effects of these learning environments. Up to now, empirical research mainly appears to focus on the development, usability and initial implementation of AR for learning. Limited review results reflect the motivational value of AR, its potential for training psychomotor skills and the capacity to visualize the invisible, possibly leading to enhanced conceptual understanding of complex causality.

  15. Aspects of User Experience in Augmented Reality

    OpenAIRE

    Madsen, Jacob Boesen

    2016-01-01

    In Augmented Reality applications, the real environment is annotated or enhanced with computer-generated graphics.This is a topic that has been researched in the recent decades, but for many people this is a brand new and never heard of topic.The main focus of this thesis is investigations in human factors related to Augmented Reality. This is investigated partly as how Augmented Reality applications are used in unsupervised settings, and partly in specific evaluations related to user perform...

  16. AB027. Penile augmentation: informed text briefing

    OpenAIRE

    Park, Nam Cheol

    2016-01-01

    The men?s desire to have larger and longer penis have created endless medical demands throughout human history. Until up to date, various medical skills for penile augmentation have developed in aspect of experimental and clinical outcome. Recently with throwing away socially unacceptable ideas, the need for penile augmentation is considered as equivalent level with mammoplasty for breast augmentation in women for cosmetic and psychological reason. Concurrently advanced technologies in medica...

  17. Interactive Assembly Guide using Augmented Reality

    DEFF Research Database (Denmark)

    Andersen, Martin; Andersen, Rasmus Skovgaard; Larsen, Christian Lindequist

    2009-01-01

    This paper presents an Augmented Reality system for aiding a pump assembling process at Grundfos, one of the leading pump producers. Stable pose estimation of the pump is required in order to augment the graphics correctly. This is achieved by matching image edges with synthesized edges from CAD...... norm. A dynamic visualization of the augmented graphics provides the user with guidance. Usability tests show that the accuracy of the system is sufficient for assembling the pump....

  18. Enhancing tourism with augmented and virtual reality

    OpenAIRE

    Jenny, Sandra

    2017-01-01

    Augmented and virtual reality are on the advance. In the last twelve months, several interesting devices have entered the market. Since tourism is one of the fastest growing economic sectors in the world and has become one of the major players in international commerce, the aim of this thesis was to examine how tourism could be enhanced with augmented and virtual reality. The differences and functional principles of augmented and virtual reality were investigated, general uses were described ...

  19. Probing the CMP‐Sialic Acid Donor Specificity of Two Human β‐d‐Galactoside Sialyltransferases (ST3Gal I and ST6Gal I) Selectively Acting on O‐ and N‐Glycosylproteins

    Science.gov (United States)

    Noel, Maxence; Gilormini, Pierre‐André; Cogez, Virginie; Yamakawa, Nao; Vicogne, Dorothée; Lion, Cédric; Biot, Christophe; Guérardel, Yann

    2017-01-01

    Abstract Sialylation of glycoproteins and glycolipids is catalyzed by sialyltransferases in the Golgi of mammalian cells, whereby sialic acid residues are added at the nonreducing ends of oligosaccharides. Because sialylated glycans play critical roles in a number of human physio‐pathological processes, the past two decades have witnessed the development of modified sialic acid derivatives for a better understanding of sialic acid biology and for the development of new therapeutic targets. However, nothing is known about how individual mammalian sialyltransferases tolerate and behave towards these unnatural CMP‐sialic acid donors. In this study, we devised several approaches to investigate the donor specificity of the human β‐d‐galactoside sialyltransferases ST6Gal I and ST3Gal I by using two CMP‐sialic acids: CMP‐Neu5Ac, and CMP‐Neu5N‐(4pentynoyl)neuraminic acid (CMP‐SiaNAl), an unnatural CMP‐sialic acid donor with an extended and functionalized N‐acyl moiety. PMID:28395125

  20. Probing the CMP-Sialic Acid Donor Specificity of Two Human β-d-Galactoside Sialyltransferases (ST3Gal I and ST6Gal I) Selectively Acting on O- and N-Glycosylproteins.

    Science.gov (United States)

    Noel, Maxence; Gilormini, Pierre-André; Cogez, Virginie; Yamakawa, Nao; Vicogne, Dorothée; Lion, Cédric; Biot, Christophe; Guérardel, Yann; Harduin-Lepers, Anne

    2017-07-04

    Sialylation of glycoproteins and glycolipids is catalyzed by sialyltransferases in the Golgi of mammalian cells, whereby sialic acid residues are added at the nonreducing ends of oligosaccharides. Because sialylated glycans play critical roles in a number of human physio-pathological processes, the past two decades have witnessed the development of modified sialic acid derivatives for a better understanding of sialic acid biology and for the development of new therapeutic targets. However, nothing is known about how individual mammalian sialyltransferases tolerate and behave towards these unnatural CMP-sialic acid donors. In this study, we devised several approaches to investigate the donor specificity of the human β-d-galactoside sialyltransferases ST6Gal I and ST3Gal I by using two CMP-sialic acids: CMP-Neu5Ac, and CMP-Neu5N-(4pentynoyl)neuraminic acid (CMP-SiaNAl), an unnatural CMP-sialic acid donor with an extended and functionalized N-acyl moiety. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  1. Augmented reality in dentistry: a current perspective.

    Science.gov (United States)

    Kwon, Ho-Beom; Park, Young-Seok; Han, Jung-Suk

    2018-02-21

    Augmentation reality technology offers virtual information in addition to that of the real environment and thus opens new possibilities in various fields. The medical applications of augmentation reality are generally concentrated on surgery types, including neurosurgery, laparoscopic surgery and plastic surgery. Augmentation reality technology is also widely used in medical education and training. In dentistry, oral and maxillofacial surgery is the primary area of use, where dental implant placement and orthognathic surgery are the most frequent applications. Recent technological advancements are enabling new applications of restorative dentistry, orthodontics and endodontics. This review briefly summarizes the history, definitions, features, and components of augmented reality technology and discusses its applications and future perspectives in dentistry.

  2. A study on volunteer augmentation navigation technology

    Science.gov (United States)

    Wu, HaiTao; Lu, XiaoChun; Zou, DeCai; Han, Tao

    2011-06-01

    Navigation augmentation technology is one of the most common methods to increase the continuity, reliability and integrity of the global satellite navigation system. The concept of volunteer augmentation navigation (VNA) is proposed and the elements and topological structure of VNA are also analyzed in this paper. The study focuses on the neural network model that volunteers and ordinary users use modern communication information network to exchange self-organizing information. The neural cell model of Volunteer Augmentation Navigation using shared information is built. Thus interactive general relative positioning is realized. Then basic theories and methods of volunteer augmentation navigation are formed on the basis of the above-mentioned study. This study of realization mechanism of volunteer augmentation technology helps to form a relatively integral architecture of volunteer augmentation navigation. A user self-service satellite navigation augmentation which combines information exchange and navigation services may strengthen the continuity, reliability and integrity of the navigation system. The volunteer augmentation navigation theory proposed in this paper improves the traditional satellite navigation application model and expands the connotation and denotation of satellite navigation augmentation methods.

  3. A small-molecule modulator of poly-alpha 2,8-sialic acid expression on cultured neurons and tumor cells.

    Science.gov (United States)

    Mahal, L K; Charter, N W; Angata, K; Fukuda, M; Koshland, D E; Bertozzi, C R

    2001-10-12

    Poly-alpha2,8-sialic acid (PSA) has been implicated in numerous normal and pathological processes, including development, neuronal plasticity, and tumor metastasis. We report that cell surface PSA expression can be reversibly inhibited by a small molecule, N-butanoylmannosamine (ManBut). Inhibition occurs through a metabolic mechanism in which ManBut is converted to unnatural sialic acid derivatives that effectively act as chain terminators during cellular PSA biosynthesis. N-Propanoylmannosamine (ManProp), which differs from ManBut by a single methylene group, did not inhibit PSA biosynthesis. Modulation of PSA expression by chemical means has a role complementary to genetic and biochemical approaches in the study of complex PSA-mediated events.

  4. NanR, a Transcriptional Regulator That Binds to the Promoters of Genes Involved in Sialic Acid Metabolism in the Anaerobic Pathogen Clostridium perfringens.

    Directory of Open Access Journals (Sweden)

    Blair Therit

    Full Text Available Among many other virulence factors, Clostridium perfringens produces three sialidases NanH, NanI and NanJ. NanH lacks a secretion signal peptide and is predicted to be an intracellular enzyme, while NanI and NanJ are secreted. Previously, we had identified part of an operon encoding NanE (epimerase and NanA (sialic acid lyase enzymes. Further analysis of the entire operon suggests that it encodes a complete pathway for the transport and metabolism of sialic acid along with a putative transcriptional regulator, NanR. The addition of 30 mM N-acetyl neuraminic acid (Neu5Ac to a semi-defined medium significantly enhanced the growth yield of strain 13, suggesting that Neu5Ac can be used as a nutrient. C. perfringens strain 13 lacks a nanH gene, but has NanI- and NanJ-encoding genes. Analysis of nanI, nanJ, and nanInanJ mutants constructed by homologous recombination revealed that the expression of the major sialidase, NanI, was induced by the addition of Neu5Ac to the medium, and that in separate experiments, the same was true of a nanI-gusA transcriptional fusion. For the nanI and nanJ genes, primer extension identified three and two putative transcription start sites, respectively. Gel mobility shift assays using purified NanR and DNA from the promoter regions of the nanI and nanE genes showed high affinity, specific binding by NanR. We propose that NanR is a global regulator of sialic acid-associated genes and that it responds, in a positive feedback loop, to the concentration of sialic acid in the cell.

  5. NanR, a Transcriptional Regulator That Binds to the Promoters of Genes Involved in Sialic Acid Metabolism in the Anaerobic Pathogen Clostridium perfringens.

    Science.gov (United States)

    Therit, Blair; Cheung, Jackie K; Rood, Julian I; Melville, Stephen B

    2015-01-01

    Among many other virulence factors, Clostridium perfringens produces three sialidases NanH, NanI and NanJ. NanH lacks a secretion signal peptide and is predicted to be an intracellular enzyme, while NanI and NanJ are secreted. Previously, we had identified part of an operon encoding NanE (epimerase) and NanA (sialic acid lyase) enzymes. Further analysis of the entire operon suggests that it encodes a complete pathway for the transport and metabolism of sialic acid along with a putative transcriptional regulator, NanR. The addition of 30 mM N-acetyl neuraminic acid (Neu5Ac) to a semi-defined medium significantly enhanced the growth yield of strain 13, suggesting that Neu5Ac can be used as a nutrient. C. perfringens strain 13 lacks a nanH gene, but has NanI- and NanJ-encoding genes. Analysis of nanI, nanJ, and nanInanJ mutants constructed by homologous recombination revealed that the expression of the major sialidase, NanI, was induced by the addition of Neu5Ac to the medium, and that in separate experiments, the same was true of a nanI-gusA transcriptional fusion. For the nanI and nanJ genes, primer extension identified three and two putative transcription start sites, respectively. Gel mobility shift assays using purified NanR and DNA from the promoter regions of the nanI and nanE genes showed high affinity, specific binding by NanR. We propose that NanR is a global regulator of sialic acid-associated genes and that it responds, in a positive feedback loop, to the concentration of sialic acid in the cell.

  6. Sialic Acids Attached to N- and O-glycans Within the Nav1.4 D1S5-S6 Linker Contribute to Channel Gating

    Science.gov (United States)

    Ednie, Andrew R.; Harper, Jean M.; Bennett, Eric S.

    2014-01-01

    Background Voltage-gated Na+ channels (Nav) are responsible for the initiation and conduction of neuronal and muscle action potentials. Nav gating can be altered by sialic acids attached to channel N-glycans, typically through isoform-specific electrostatic mechanisms. Methods Using two sets of Chinese Hamster Ovary cell lines with varying abilities to glycosylate glycoproteins, we show for the first time that sialic acids attached to O-glycans and N-glycans within the Nav1.4 D1S5-S6 linker modulate Nav gating. Results All measured steady-state and kinetic parameters were shifted to more depolarized potentials under conditions of essentially no sialylation. When sialylation of only N-glycans or of only O-glycans was prevented, the observed voltage-dependent parameter values were intermediate between those observed under full versus no sialylation. Immunoblot gel shift analyses support the biophysical data. Conclusions The data indicate that sialic acids attached to both N- and O-glycans residing within the Nav1.4 D1S5-S6 linker modulate channel gating through electrostatic mechanisms, with the relative contribution of sialic acids attached to N- versus O-glycans on channel gating being similar. General Significance Protein N- and O-glycosylation can modulate ion channel gating simultaneously. These data also suggest that Nav gating might be altered simply through exposure to different levels of sugar residues that serve as substrates for N- and O-glycosylation. Thus, in disease states that affect sugar substrate levels, the glycosylation process would be impacted, likely resulting in changes in Nav sialylation levels that would lead to modulated channel gating, AP waveforms and conduction. PMID:25450184

  7. α2,3 and α2,6 N-Linked Sialic Acids Facilitate Efficient Binding and Transduction by Adeno-Associated Virus Types 1 and 6

    OpenAIRE

    Wu, Zhijian; Miller, Edward; Agbandje-McKenna, Mavis; Samulski, Richard Jude

    2006-01-01

    Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be the attachment receptors for AAV type 2 and types 4 and 5, respectively. In this report, we identify the receptor for the two closely related serotype...

  8. Replication of avian, human and swine influenza viruses in porcine respiratory explants and association with sialic acid distribution

    Directory of Open Access Journals (Sweden)

    Nauwynck Hans J

    2010-02-01

    Full Text Available Abstract Background Throughout the history of human influenza pandemics, pigs have been considered the most likely "mixing vessel" for reassortment between human and avian influenza viruses (AIVs. However, the replication efficiencies of influenza viruses from various hosts, as well as the expression of sialic acid (Sia receptor variants in the entire porcine respiratory tract have never been studied in detail. Therefore, we established porcine nasal, tracheal, bronchial and lung explants, which cover the entire porcine respiratory tract with maximal similarity to the in vivo situation. Subsequently, we assessed virus yields of three porcine, two human and six AIVs in these explants. Since our results on virus replication were in disagreement with the previously reported presence of putative avian virus receptors in the trachea, we additionally studied the distribution of sialic acid receptors by means of lectin histochemistry. Human (Siaα2-6Gal and avian virus receptors (Siaα2-3Gal were identified with Sambucus Nigra and Maackia amurensis lectins respectively. Results Compared to swine and human influenza viruses, replication of the AIVs was limited in all cultures but most strikingly in nasal and tracheal explants. Results of virus titrations were confirmed by quantification of infected cells using immunohistochemistry. By lectin histochemistry we found moderate to abundant expression of the human-like virus receptors in all explant systems but minimal binding of the lectins that identify avian-like receptors, especially in the nasal, tracheal and bronchial epithelium. Conclusions The species barrier that restricts the transmission of influenza viruses from one host to another remains preserved in our porcine respiratory explants. Therefore this system offers a valuable alternative to study virus and/or host properties required for adaptation or reassortment of influenza viruses. Our results indicate that, based on the expression of Sia

  9. A Study of Lipid- and Protein- Bound Sialic Acids for the Diagnosis of Bladder Cancer and Their Relationships with the Severity of Malignancy

    Directory of Open Access Journals (Sweden)

    Shima Habibi

    2014-05-01

    Full Text Available Background: The gold standard for detection of bladder cancer is cystoscopy, which is an invasive and complicated procedure. Our study was conducted to find a tumor marker with high specificity, sensitivity, and accuracy for the diagnosis of bladder cancer. Methods: Serum samples were collected from 58 bladder cancer patients and 60 healthy control subjects. Levels of lipid-bound sialic acid (LBSA, and protein-bound sialic acid (PBSA were measured spectrophotometrically by Aminoff’s method. Results: Mean levels of both markers were found to be significantly higher in the patients than the healthy controls. Positive correlations were observed between serum levels of lipid- (r=0.283, p<0.05 and protein- bound (r=0.56, p<0.05 sialic acids and the grade of malignancy. To differentiate patients with bladder tumors from healthy controls, cut-offpoints were determined for each of the two parameters based on Receiver Operating Characteristic (ROC curve analysis (LBSA=21.25 mg/dL, PBSA=6.15 mg/dL. The data showed good sensitivities (LBSA=89%, PBSA=79%, specificities (LBSA=70%, PBSA=70% and accuracies (LBSA=83%, PBSA=81% for both markers. Conclusion: Measuring serum LBSA and PBSA by this simple, reproducible, noninvasive, and inexpensive method can accurately discriminate cancer patients from healthy individuals.

  10. Sperm and Egg Jelly Coat from Sea Urchin Lytechinus variegatus Collected in Rio de Janeiro Contain Distinct Sialic Acid-Rich Polysaccharides

    Directory of Open Access Journals (Sweden)

    Gabrielle M. Valle

    2015-08-01

    Full Text Available This work found the occurrence of a distinct sialic acid-rich polysaccharide in the sperm surface of the sea urchin Lytechinus variegatus, which differed significantly from a similar molecule found in the egg jelly. The sperm polysaccharide extracted by protease digestion was purified using anion exchange chromatography and characterized using agarose gel electrophoresis, gas chromatography/mass spectrometry and NMR spectroscopy. This polysaccharide was highly sulfated and composed almost exclusively of N-acetylneuraminic acid. In contrast, the sialic acid-rich polysaccharide from the egg jelly was composed of N-glycolylneuraminic acid and contains several other hexoses in its structure. This new molecule could help to characterize in further detail the mechanism of fertilization in the sea urchin model system. Sulfated polysaccharides from the jelly coat of sea urchins showed species-specificity in inducing the sperm acrosome reaction, providing an example of a signal transduction event regulated by the sulfated polysaccharide. The new sialic acid-rich polysaccharide found in the sperm head could represent a new molecule involved in the biology of the sea urchin fertilization.

  11. Increased protein oxidation and loss of protein-bound sialic acid in hepatic tissues of D-galactose induced aged rats.

    Science.gov (United States)

    Cakatay, Ufuk; Aydın, Seval; Atukeren, Pınar; Yanar, Karolin; Sitar, Mustafa E; Dalo, Enis; Uslu, Ezel

    2013-07-01

    A redox basis of the increased oxidative protein damage and free radical-mediated desialylation have not been fully elucidated in aging. It is well known that the incidence of several liver diseases increase with age. This original research focuses on protein oxidation mechanisms and protein-bound sialic acid levels in liver tissue of the mimetic aging rats. Injection of D-galactose (60 mg/kg/day) for six weeks to male Sprague-Dawley rats (20-week-old) used to establish mimetic aging model. We investigated the tissue levels of various protein oxidation markers such as protein carbonyl groups, suitable advanced oxidation protein products and protein thiol groups. Our study also covered protein-bound sialic acid in liver tissue of D-galactose-induced aging rats. PCO (Protein Carbonyl Groups), P-OOH (Protein Hydroperoxides) and AOPP (Advanced Oxidation Protein Products) levels in aging rats were significantly higher compared to young control groups. On the other hand, P-SH (Protein Thiol Groups) levels were not found to be different between two groups. SA (Sialic Acid) levels in D-galactose-induced aging rats were significantly lower compared to control groups. Our results demonstrated greater susceptibility to hepatic oxidative protein damage and desialylation of hepatocellular proteins in Dgalactose- induced aging rats. These molecular mechanisms may be operative in the many age-related liver diseases, which are pertinent to increased oxidative stress and altered redox homeostasis.

  12. Characterization of the sialic acid binding activity of influenza A viruses using soluble variants of the H7 and H9 hemagglutinins.

    Directory of Open Access Journals (Sweden)

    Anne-Kathrin Sauer

    Full Text Available Binding of influenza viruses to target cells is mediated by the viral surface protein hemagglutinin. To determine the presence of binding sites for influenza A viruses on cells and tissues, soluble hemagglutinins of the H7 and H9 subtype were generated by connecting the hemagglutinin ectodomain to the Fc portion of human immunoglobulin G (H7Fc and H9Fc. Both chimeric proteins bound to different cells and tissues in a sialic acid-dependent manner. Pronounced differences were observed between H7Fc and H9Fc, in the binding both to different mammalian and avian cultured cells and to cryosections of the respiratory epithelium of different virus host species (turkey, chicken and pig. Binding of the soluble hemagglutinins was similar to the binding of virus particles, but showed differences in the binding pattern when compared to two sialic acid-specific plant lectins. These findings were substantiated by a comparative glycan array analysis revealing a very narrow recognition of sialoglycoconjugates by the plant lectins that does not reflect the glycan structures preferentially recognized by H7Fc and H9Fc. Thus, soluble hemagglutinins may serve as sialic acid-specific lectins and are a more reliable indicator of the presence of binding sites for influenza virus HA than the commonly used plant lectins.

  13. Augmented reality for improved safety

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    Sometimes, CERN experts have to operate in low visibility conditions or in the presence of possible hazards. Minimising the duration of the operation and reducing the risk of errors is therefore crucial to ensuring the safety of personnel. The EDUSAFE project integrates different technologies to create a wearable personnel safety system based on augmented reality.    The EDUSAFE integrated safety system uses a camera mounted on the helmet to monitor the working area.  In its everyday operation of machines and facilities, CERN adopts a whole set of measures and safety equipment to ensure the safety of its personnel, including personal wearable safety devices and access control systems. However, sometimes, scheduled and emergency maintenance work needs to be done in zones with potential cryogenic hazards, in the presence of radioactive equipment or simply in demanding conditions where visibility is low and moving around is difficult. The EDUSAFE Marie Curie Innovative&...

  14. Augmented Reality and Mobile Art

    Science.gov (United States)

    Gwilt, Ian

    The combined notions of augmented-reality (AR) and mobile art are based on the amalgamation of a number of enabling technologies including computer imaging, emergent display and tracking systems and the increased computing-power in hand-held devices such as Tablet PCs, smart phones, or personal digital assistants (PDAs) which have been utilized in the making of works of art. There is much published research on the technical aspects of AR and the ongoing work being undertaken in the development of faster more efficient AR systems [1] [2]. In this text I intend to concentrate on how AR and its associated typologies can be applied in the context of new media art practices, with particular reference to its application on hand-held or mobile devices.

  15. Sensory augmentation for the blind

    Directory of Open Access Journals (Sweden)

    Silke Manuela Kärcher

    2012-03-01

    Full Text Available Enacted theories of consciousness conjecture that perception and cognition arise from an active experience of the regular relations that are tying together the sensory stimulation of different modalities and associated motor actions. Previous experiments investigated this concept by employing the technique of sensory substitution. Building on these studies, here we test a set of hypotheses derived from this framework and investigate the utility of sensory augmentation in handicapped people. We provide a late blind subject with a new set of sensorimotor laws: A vibro-tactile belt continually signals the direction of magnetic north. The subject completed a set of behavioral tests before and after an extended training period. The tests were complemented by questionnaires and interviews. This newly supplied information improved performance on different time scales. In a pointing task we demonstrate an instant improvement of performance based on the signal provided by the device. Furthermore, the signal was helpful in relevant daily tasks, often complicated for the blind, such as keeping a direction over longer distances or taking shortcuts in familiar environments. A homing task with an additional attentional load demonstrated a significant improvement after training. The subject found the directional information highly expedient for the adjustment of his inner maps of familiar environments and describes an increase in his feeling of security when exploring unfamiliar environments with the belt. The results give evidence for a firm integration of the newly supplied signals into the behavior of this late blind subject with better navigational performance and more courageous behavior in unfamiliar environments. Most importantly, the complementary information provided by the belt lead to a positive emotional impact with enhanced feeling of security. This experimental approach demonstrates the potential of sensory augmentation devices for the help of

  16. Use of engineered bone for sinus augmentation.

    Science.gov (United States)

    Beaumont, Christian; Schmidt, Roswitha J; Tatakis, Dimitris N; Zafiropoulos, Gregory-George

    2008-03-01

    Tissue-engineered bone grafts represent an appealing alternative for maxillary sinus augmentation because they eliminate the significant drawbacks associated with extra- and intraoral bone-harvesting procedures. In the present case series, we document the outcomes of sinus augmentation surgery using tissue-engineered bone grafts. Three patients requiring bilateral sinus augmentation received tissue-engineered bone grafts combined with xenograft prior to implant placement. Implants were placed and loaded 6 and 12 months postaugmentation, respectively. Radiographs were taken and clinical examinations were performed preoperatively and at 4, 6, 12, and 18 months postaugmentation. Biopsies were obtained at 4 and 6 months postaugmentation. Standardized orthopantomograms were used to measure the posterior maxilla bone height. None of the patients experienced untoward complications during or following the therapeutic procedures. Ten implants were inserted into the augmented sinuses and loaded. Biopsies revealed a lack of inflammation or pathology; newly formed fibrous bone with osteoblastic activity and xenograft particles was evident. Compared to 4 months postaugmentation, augmented tissue was more mature at 6 months. The postoperative (18 months) bone height in augmented areas was significantly greater than the preoperative height (P bone height. Sinus augmentation using tissue-engineered bone grafts was successful in all three cases, permitting the subsequent insertion and loading of dental implants. The present cases demonstrated the feasibility of using engineered bone for sinus augmentation. Controlled clinical trials will be required to evaluate this new and evolving treatment modality.

  17. Enhancing Education through Mobile Augmented Reality

    Science.gov (United States)

    Joan, D. R. Robert

    2015-01-01

    In this article, the author has discussed about the Mobile Augmented Reality and enhancing education through it. The aim of the present study was to give some general information about mobile augmented reality which helps to boost education. Purpose of the current study reveals the mobile networks which are used in the institution campus as well…

  18. Augmented Reality Interfaces for Additive Manufacturing

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Frisvad, Jeppe Revall

    2017-01-01

    This paper explores potential use cases for using augmented reality (AR) as a tool to operate industrial machines. As a baseline we use an additive manufacturing system, more commonly known as a 3D printer. We implement novel augmented interfaces and controls using readily available open source...

  19. From Augmentation Media to Meme Media.

    Science.gov (United States)

    Tanaka, Yuzuru

    Computers as meta media are now evolving from augmentation media vehicles to meme media vehicles. While an augmentation media system provides a seamlessly integrated environment of various tools and documents, meme media system provides further functions to edit and distribute tools and documents. Documents and tools on meme media can easily…

  20. Aspects of User Experience in Augmented Reality

    DEFF Research Database (Denmark)

    Madsen, Jacob Boesen

    In Augmented Reality applications, the real environment is annotated or enhanced with computer-generated graphics. This is a topic that has been researched in the recent decades, but for many people this is a brand new and never heard of topic. The main focus of this thesis is investigations...... in human factors related to Augmented Reality. This is investigated partly as how Augmented Reality applications are used in unsupervised settings, and partly in specific evaluations related to user performance in supervised settings. The thesis starts by introducing Augmented Reality to the reader......, followed by a presentation of the technical areas related to the field, and different human factor areas. As a contribution to the research area, this thesis presents five separate, but sequential, papers within the area of Augmented Reality....

  1. Co-expression of sialic acid receptors compatible with avian and human influenza virus binding in emus (Dromaius novaehollandiae).

    Science.gov (United States)

    Gujjar, Naveen; Chothe, Shubhada K; Gawai, Shashikant; Nissly, Ruth; Bhushan, Gitanjali; Kanagaraj, Vijayarani; Jayarao, Bhushan M; Kathaperumal, Kumanan; Subbiah, Madhuri; Kuchipudi, Suresh V

    2017-01-01

    Influenza A viruses (IAVs) continue to threaten animal and human health with constant emergence of novel variants. While aquatic birds are a major reservoir of most IAVs, the role of other terrestrial birds in the evolution of IAVs is becoming increasingly evident. Since 2006, several reports of IAV isolations from emus have surfaced and avian influenza infection of emus can lead to the selection of mammalian like PB2-E627K and PB2-D701N mutants. However, the potential of emus to be co-infected with avian and mammalian IAVs is not yet understood. As a first step, we investigated sialic acid (SA) receptor distribution across major organs and body systems of emu and found a widespread co-expression of both SAα2,3Gal and SAα2,6Gal receptors in various tissues that are compatible with avian and human IAV binding. Our results suggest that emus could allow genetic recombination and hence play an important role in the evolution of IAVs. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Short-term intra-nasal erythropoietin administration with low sialic acid content is without toxicity or erythropoietic effects.

    Science.gov (United States)

    Lagarto, Alicia; Bueno, Viviana; Sanchez, Jose A; Couret, Micaela; Valdes, Odalys; Barzaga, Pedro; Lopez, Raisell; Guerra, Isbel; Gabilondo, Tatiana; Vega, Yamile; Beausoleil, Irene

    2012-11-01

    The objective of this investigation was to assess the toxicological potential of nasal formulation of erythropoietin with low sialic acid content (Neuro EPO) after 28 days of intra-nasal dosing in rats besides to evaluate the immunogenicity and erythropoietic effect of the test substance. Healthy Wistar rats of both sexes were used for 28 days subacute toxicity and immunogenicity assays. Doses evaluated were 3450, 4830 and 6900 UI/kg/day. The toxicological endpoints examined included animal body weight, food consumption, hematological and biochemical patterns, antibodies determination, selected tissue weights and histopathological examination. Reversibility of toxic effects was evaluated at high dose 14 days after treatment period. Female B6D2F1 mice were used for evaluated erythropoietic effect of the nasal formulation. Hematological endpoints were examined every week during 28 days of intra-nasal dosing of 6900 UI/kg/day. Variations of hematological patterns were not observed after 28 days of intranasal dosing. A slight increase in glucose level of treated animals within the normal range was observed. This effect was not dose related and was reversible. Antibody formation was not observed in any of the test doses. Histopathological examination of organs and tissues did not reveal treatment induced changes. The administration of Neuro EPO in normocythaemic mice did not produce erythropoietic effect. These results suggest that Neuro EPO could be used as a neuroprotective agent, without significant systemic haematological side effects.

  3. A fast and biocompatible living virus labeling method based on sialic acid-phenylboronic acid recognition system.

    Science.gov (United States)

    Huang, Li-Li; Jin, Yong-Jie; Zhao, Dongxu; Yu, Chao; Hao, Jian; Xie, Hai-Yan

    2014-04-01

    The sialic acid (SA)-phenylboronic acid (PBA) recognition system is of particular interest in the bioconjugation field, because it is simple, fast, efficient, and biocompatible. In this paper, we report a novel method for reversibly labeling living virus with quantum dots (QDs) by taking advantage of this SA-PBA recognition system. The QDs were initially modified with PBA (QDs-PBA) to target them to the surface of vesicular stomatitis virus (VSV), which has abundant with SA on its envelope. The QDs-PBA was of good monodispersity and strong fluorescence, and could be conjugated with VSV by simply incubating with native VSV for 10 min at 37 °C, producing QDs-VSV that was capable of being imaged at the single virion level. The labeling efficiency attained 83 ± 4.3 % (mean ± SD); meanwhile, the activity and recognition ability of the labeled virus were minimally affected. This method was simple, rapid, and reversible. This work promotes the virus labeling development to a new step. That is, native viruses can be reversibly labeled without any modification.

  4. Clostridium botulinum serotype D neurotoxin and toxin complex bind to bovine aortic endothelial cells via sialic acid.

    Science.gov (United States)

    Yoneyama, Tohru; Miyata, Keita; Chikai, Tomoyuki; Mikami, Akifumi; Suzuki, Tomonori; Hasegawa, Kimiko; Ikeda, Toshihiko; Watanabe, Toshihiro; Ohyama, Tohru; Niwa, Koichi

    2008-12-01

    Botulinum neurotoxin (BoNT) is produced as a large toxin complex (L-TC) associated with nontoxic nonhemagglutinin (NTNHA) and three hemagglutinin subcomponents (HA-70, -33 and -17). The binding properties of BoNT to neurons and L-TC to intestinal epithelial cells are well documented, while those to other tissues are largely unknown. Here, to obtain novel insights into the pathogenesis of foodborne botulism, we examine whether botulinum toxins bind to vascular endothelial cells. BoNT and 750 kDa L-TC (a complex of BoNT, NTNHA and HAs) of Clostridium botulinum serotype D were incubated with bovine aortic endothelial cells (BAECs), and binding to the cells was assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot. Both BoNT and L-TC bound to BAECs, with L-TC showing stronger binding. Binding of BoNT and L-TC to BAECs was significantly inhibited by N-acetyl neuraminic acid in the cell culture medium or by treatment of the cells with neuraminidase. However, galactose, lactose or N-acetyl galactosamine did not significantly inhibit toxin binding to the cells. This is the first report demonstrating that BoNT and L-TC bind to BAECs via sialic acid, and this mechanism may be important in the trafficking pathway of BoNT in foodborne botulism.

  5. Functional expression of the CMP-sialic acid transporter in Escherichia coli and its identification as a simple mobile carrier.

    Science.gov (United States)

    Tiralongo, Joe; Ashikov, Angel; Routier, Françoise; Eckhardt, Matthias; Bakker, Hans; Gerardy-Schahn, Rita; von Itzstein, Mark

    2006-01-01

    The architectural conservation of nucleotide sugar transport proteins (NSTs) enabled the theoretical prediction of putative NSTs in diverse gene databases. In the human genome, 17 NST sequences have been identified but only six have been unequivocally characterized with respect to their transport specificities. Defining transport characteristics of recombinant NSTs has become a major challenge because true zero background systems are widely absent. Production of recombinant NSTs in heterologous systems has developed multifunctionality for some NSTs leading to a novel level of complexity in the field. Assuming that (1) the specificity of NSTs is determined at the primary sequence level and (2) the proteins are autonomously functional units, final definition of the substrate specificity will depend on the use of isolated transport proteins. Herein, we describe the first report of the functional expression of mouse CMP-sialic acid transporter (CST) in Escherichia coli and thus provide significant progress towards the production of transporter proteins in quantities suitable for functional and structural analyses. Recovery of the active NST from inclusion bodies was achieved after solubilization with 8 M urea and stepwise renaturation. After reconstitution into phospholipid vesicles, the recombinant protein demonstrated specific transport for CMP-N-acetylneuraminic acid (CMP-Neu5Ac) with no transport of UDP-sugars. Kinetic studies carried out with CMP-Neu5Ac and established CMP-Neu5Ac antagonist's evaluated natural conformation of the reconstituted protein and clearly demonstrate that the transporter acts as a simple mobile carrier.

  6. Synthesis of CMP-9''-modified-sialic acids as donor substrate analogues for mammalian and bacterial sialyltransferases.

    Science.gov (United States)

    Kajihara, Yasuhiro; Kamitani, Toshimi; Sato, Reiko; Kamei, Naoki; Miyazaki, Tatsuo; Okamoto, Ryo; Sakakibara, Thoru; Tsuji, Takashi; Yamamoto, Takeshi

    2007-09-03

    Cytidine-5'-monophospho-sialic acid (CMP-Neu5Ac) derivatives bearing a phenyl group in which the tether length between the phenyl group and the 9-position of Neu5Ac varied were synthesized and evaluated as substrates for sialyltransferases. In the synthesis of the compounds, a coupling reaction between methyl 5-acetamido-4,7,8-tri-O-acetyl-9-azido-3,5,9-trideoxy-beta-D-glycero-D-galacto-2-nonulopyranosonate and 2-cyanoethyl 2',3'-O,N4, triacetylcytidine-5'-yl N,N-diisopropylphosphoramidite was carried out and the phosphite derivative thus obtained was oxidized and then deprotected to yield CMP-9''-azido-Neu5Ac. Modification of the 9-amino group prepared by reduction of the azido groups was performed by the use of several phenyl-substituted alkylcarboxylic acid derivatives. Using these CMP-9''-modified-Neu5Ac analogues bearing the phenyl-substituted alkyl-amide group, sialyltransferase assays were performed with both rat liver alpha-(2-->6)-sialyltransferase and Photobacterium alpha-(2-->6)-sialyltransferase. These 9-modified analogues could be transferred to disaccharide acceptors, and a practical enzymatic synthesis using CMP-9''-modified-Neu5Ac yielded sialoside analogues and sialylglycoproteins in good yield. These experiments demonstrate that the Photobacterium sialyltransferase can be used in the synthesis of sialoside analogues having a large substituent at the 9-position of Neu5Ac.

  7. Sialic Acid Expression in the Mosquito Aedes aegypti and Its Possible Role in Dengue Virus-Vector Interactions

    Directory of Open Access Journals (Sweden)

    Jorge Cime-Castillo

    2015-01-01

    Full Text Available Dengue fever (DF is the most prevalent arthropod-borne viral disease which affects humans. DF is caused by the four dengue virus (DENV serotypes, which are transmitted to the host by the mosquito Aedes aegypti that has key roles in DENV infection, replication, and viral transmission (vector competence. Mosquito saliva also plays an important role during DENV transmission. In this study, we detected the presence of sialic acid (Sia in Aedes aegypti tissues, which may have an important role during DENV-vector competence. We also identified genome sequences encoding enzymes involved in Sia pathways. The cDNA for Aedes aegypti CMP-Sia synthase (CSAS was amplified, cloned, and functionally evaluated via the complementation of LEC29.Lec32 CSAS-deficient CHO cells. AedesCSAS-transfected LEC29.Lec32 cells were able to express Sia moieties on the cell surface. Sequences related to α-2,6-sialyltransferase were detected in the Aedes aegypti genome. Likewise, we identified Sia-α-2,6-DENV interactions in different mosquito tissues. In addition, we evaluated the possible role of sialylated molecules in a salivary gland extract during DENV internalization in mammalian cells. The knowledge of early DENV-host interactions could facilitate a better understanding of viral tropism and pathogenesis to allow the development of new strategies for controlling DENV transmission.

  8. Fluorescent labeling of a carboxyl group of sialic acid for MALDI-MS analysis of sialyloligosaccharides and ganglioside.

    Science.gov (United States)

    Endo, Shin-ichi; Morita, Minoru; Ueno, Masaki; Maeda, Tadakazu; Terabayashi, Takashi

    2009-01-23

    We developed a modified method enabling stable MALDI-MS analysis and fluorescent detection of sialyl-compounds. The modification involved the amidation of sialic acid (Neu5Ac) at the position of the carboxyl group using the fluorescent reagent, 2-(2-pyridilamino)ethylamine (PAEA). In this study the following sialyl-compounds were amidated, 3'-sialyllactose (3'-SL), 6'-sialyllactose (6'-SL), and ganglioside GM3. Yields of PAEA-3'-SL, PAEA-6'-SL, and PAEA-GM3 were 45%, 60%, and 30%, respectively. The PAEA-amidation enabled fluorescence detection of structural isomers using HPLC and TLC at sensitivity levels as low as pmol. In MALDI-TOF-MS and/or MS/MS analysis in positive ion mode, PAEA-amidation provided the following advantages: suppression of preferential cleavage of Neu5Ac; enhancement of molecular-related ion intensities; simplification of MS spectra; and finally, since PAEA-amidation did not cleave the linkage between sugar and aglycon of sialylglycoconjugate, MALDI-TOF-MS and MS/MS analyses revealed the complete structure of the molecule.

  9. Augmentation Quotients for Real Representation Rings of Cyclic ...

    Indian Academy of Sciences (India)

    29

    Augmentation Quotients for Real Representation Rings of Cyclic Groups. Article Type: Reseach Article. Keywords: cyclic group; real representation; augmentation ideal; augmentation quotient. Corresponding Author: Hang Liu, Ph.D. Shaanxi Normal University. Xi'an, Shaanxi CHINA. Corresponding Author Secondary.

  10. Augmented Reality in Tourism - Research and Applications Overview

    National Research Council Canada - National Science Library

    Anabel L. Kečkeš; Igor Tomičić

    2017-01-01

    Augmented reality is a complex interdisciplinary field utilizing information technologies in diverse areas such as medicine, education, architecture, industry, tourism and others, augmenting the real...

  11. Augmented reality: past, present, future

    Science.gov (United States)

    Inzerillo, Laura

    2013-03-01

    A great opportunity has permitted to carry out a cultural, historical, architectural and social research with great impact factor on the international cultural interest. We are talking about the realization of a museum whose the main theme is the visit and the discovery of a monument of great prestige: the monumental building the "Steri" in Palermo. The museum is divided into sub themes including the one above all, that has aroused the international interest so much that it has been presented the instance to include the museum in the cultural heritage of UNESCO. It is the realization of a museum path that regards the cells of the Inquisition, which are located just inside of some buildings of the monumental building. The project, as a whole, is faced, in a total view, between the various competences implicated: historic, chemic, architectonic, topographic, drawing, representation, virtual communication, informatics. The birth of the museum will be a sum of the results of all these disciplines involved. Methodology, implementation, fruition, virtual museum, goals, 2D graphic restitution, effects on the cultural heritage and landscape environmental, augmented reality, Surveying 2D and 3D, hi-touch screen, Photogrammetric survey, Photographic survey, representation, drawing 3D and more than this has been dealt with this research.

  12. Digital Augmented Reality Audio Headset

    Directory of Open Access Journals (Sweden)

    Jussi Rämö

    2012-01-01

    Full Text Available Augmented reality audio (ARA combines virtual sound sources with the real sonic environment of the user. An ARA system can be realized with a headset containing binaural microphones. Ideally, the ARA headset should be acoustically transparent, that is, it should not cause audible modification to the surrounding sound. A practical implementation of an ARA mixer requires a low-latency headphone reproduction system with additional equalization to compensate for the attenuation and the modified ear canal resonances caused by the headphones. This paper proposes digital IIR filters to realize the required equalization and evaluates a real-time prototype ARA system. Measurements show that the throughput latency of the digital prototype ARA system can be less than 1.4 ms, which is sufficiently small in practice. When the direct and processed sounds are combined in the ear, a comb filtering effect is brought about and appears as notches in the frequency response. The comb filter effect in speech and music signals was studied in a listening test and it was found to be inaudible when the attenuation is 20 dB. Insert ARA headphones have a sufficient attenuation at frequencies above about 1 kHz. The proposed digital ARA system enables several immersive audio applications, such as a virtual audio tourist guide and audio teleconferencing.

  13. Augmented reality for mining teleoperation

    Science.gov (United States)

    Park, Andrew J.; Kazman, Rick N.

    1995-12-01

    Automated mining has been proposed as a solution to reducing mining costs associated with labor and development. Quite simply, no-one will need to work underground. A series of special-purpose mining vehicles is currently being designed for both semi-autonomous operation and teleoperation. A preliminary implementation at INCO's North Mine complex in Copper Cliff, Ontario, Canada, has met with great success. Improvements are required, however, in the presentation and integration of feedback from the remotely operated vehicle due to the poor video image quality. Depth cues in particular have been found to be deficient. Work currently underway at the University of Waterloo involves the development of a graphics engine responsible for the integration and rendering of data from various sources including: live video (analog and/or digital), range-finding data, an intelligent vision system, CAD mine models, and supervisory control and data acquisition systems. Graphical overlays on a live video feed are being examined as a means of enhancing and augmenting the human operator's visual input. We are investigating a tool-set which addresses the requirements of teleoperation in the context of a mining environment. This includes the integration of data from a number of different sources for the purpose of interactive mine planning and operation.

  14. Augmented reality in surgical procedures

    Science.gov (United States)

    Samset, E.; Schmalstieg, D.; Vander Sloten, J.; Freudenthal, A.; Declerck, J.; Casciaro, S.; Rideng, Ø.; Gersak, B.

    2008-02-01

    Minimally invasive therapy (MIT) is one of the most important trends in modern medicine. It includes a wide range of therapies in videoscopic surgery and interventional radiology and is performed through small incisions. It reduces hospital stay-time by allowing faster recovery and offers substantially improved cost-effectiveness for the hospital and the society. However, the introduction of MIT has also led to new problems. The manipulation of structures within the body through small incisions reduces dexterity and tactile feedback. It requires a different approach than conventional surgical procedures, since eye-hand co-ordination is not based on direct vision, but more predominantly on image guidance via endoscopes or radiological imaging modalities. ARIS*ER is a multidisciplinary consortium developing a new generation of decision support tools for MIT by augmenting visual and sensorial feedback. We will present tools based on novel concepts in visualization, robotics and haptics providing tailored solutions for a range of clinical applications. Examples from radio-frequency ablation of liver-tumors, laparoscopic liver surgery and minimally invasive cardiac surgery will be presented. Demonstrators were developed with the aim to provide a seamless workflow for the clinical user conducting image-guided therapy.

  15. Augmented reality for personalized nanomedicines.

    Science.gov (United States)

    Lee, Yugyung; Lee, Chi H

    As our understanding of onset and progress of diseases at the genetic and molecular level rapidly progresses, the potential of advanced technologies, such as 3D-printing, Socially-Assistive Robots (SARs) or augmented reality (AR), that are applied to personalized nanomedicines (PNMs) to alleviate pathological conditions, has become more prominent. Among advanced technologies, AR in particular has the greatest potential to address those challenges and facilitate the translation of PNMs into formidable clinical application of personalized therapy. As AR is about to adapt additional new methods, such as speech, voice recognition, eye tracing and motion tracking, to enable interaction with host response or biological systems in 3-D space, a combination of multiple approaches to accommodate varying environmental conditions, such as public noise and atmosphere brightness, will be explored to improve its therapeutic outcomes in clinical applications. For instance, AR glasses still being developed by Facebook or Microsoft will serve as new platform that can provide people with the health information they are interested in or various measures through which they can interact with medical services. This review has addressed the current progress and impact of AR on PNMs and its application to the biomedical field. Special emphasis is placed on the application of AR based PNMs to the treatment strategies against senior care, drug addiction and medication adherence. Published by Elsevier Inc.

  16. Determination of student opinions in augmented reality

    Directory of Open Access Journals (Sweden)

    Huseyin Bicen

    2016-11-01

    Full Text Available The rapid development of the new technology has changed classroom teaching methods and tools in a positive way. This study investigated the classroom learning with augmented reality and the impact of student opinions. 97 volunteer undergraduate students took part in this study. Results included data in the form of frequencies, percentages and descriptive statistics. The results show that, with gamification methods, augmented reality content affected students’ opinions in a positive way. When QR codes are used in the classroom, students feel independent from classroom materials and can access various resources. Moreover, students think that, when augmented reality in the classroom is used, education is more enjoyable.

  17. Augmented Reality in Architecture: Rebuilding Archeological Heritage

    Science.gov (United States)

    de la Fuente Prieto, J.; Castaño Perea, E.; Labrador Arroyo, F.

    2017-02-01

    With the development in recent years of augmented reality and the appearance of new mobile terminals and storage bases on-line, we find the possibility of using a powerful tool for transmitting architecture. This paper analyzes the relationship between Augmented Reality and Architecture. Firstly, connects the theoretical framework of both disciplines through the Representation concept. Secondly, describes the milestones and possibilities of Augmented Reality in the particular field of archaeological reconstruction. And lastly, once recognized the technology developed, we face the same analysis from a critical point of view, assessing their suitability to the discipline that concerns us is the architecture and within archeology.

  18. Evidence-Based Medicine: Breast Augmentation.

    Science.gov (United States)

    Schwartz, Michael R

    2017-07-01

    After reading this article, the participant should be able to: 1. Understand the key decisions in patient evaluation for cosmetic breast augmentation. 2. Cite key decisions in preoperative planning. 3. Discuss the risks and complications, and key patient education points in breast augmentation. Breast augmentation remains one of the most popular procedures in plastic surgery. The integral information necessary for proper patient selection, preoperative assessment, and surgical approaches are discussed. Current data regarding long term safety and complications are presented to guide the plastic surgeon to an evidence-based approach to the patient seeking breast enhancement to obtain optimal results.

  19. Importance of sialic acid residues illuminated by live animal imaging using phosphorylcholine self-assembled monolayer-coated quantum dots.

    Science.gov (United States)

    Ohyanagi, Tatsuya; Nagahori, Noriko; Shimawaki, Ken; Hinou, Hiroshi; Yamashita, Tadashi; Sasaki, Akira; Jin, Takashi; Iwanaga, Toshihiko; Kinjo, Masataka; Nishimura, Shin-ichiro

    2011-08-17

    Glycans are expected to be one of the potential signal molecules for controlling drug targeting/delivery or long-term circulation of biopharmaceuticals. However, the effect of the carbohydrates of artificially glycosylated derivatives on in vivo dynamic distribution profiles after intravenous injection of model animals remains unclear due to the lack of standardized methodology and a suitable platform. We report herein an efficient and versatile method for the preparation of multifunctional quantum dots (QDs) displaying common synthetic glycosides with excellent solubility and long-term stability in aqueous solution without loss of quantum yields. Combined use of an aminooxy-terminated thiol derivative, 11,11'-dithio bis[undec-11-yl 12-(aminooxyacetyl)amino hexa(ethyleneglycol)], and a phosphorylcholine derivative, 11-mercaptoundecylphosphorylcholine, provided QDs with novel functions for the chemical ligation of ketone-functionalized compounds and the prevention of nonspecific protein adsorption concurrently. In vivo near-infrared (NIR) fluorescence imaging of phosphorylcholine self-assembled monolayer (SAM)-coated QDs displaying various simple sugars (glyco-PC-QDs) after administration into the tail vein of the mouse revealed that distinct long-term delocalization over 2 h can be achieved in cases of QDs modified with α-sialic acid residue (Neu5Ac-PC-QDs) and control PC-QDs, while QDs bearing other common sugars, such as α-glucose (Glc-PC-QDs), α-mannose (Man-PC-QDs), α-fucose (Fuc-PC-QDs), lactose (Lac-PC-QDs), β-glucuronic acid (GlcA-PC-QDs), N-acetyl-β-D-glucosamine (GlcNAc-PC-QDs), and N-acetyl-β-D-galactosamine (GalNAc-PC-QDs) residues, accumulated rapidly (5-10 min) in the liver. Sequential enzymatic modifications of GlcNAc-PC-QDs gave Galβ1,4GlcNAc-PC-QDs (LacNAc-PC-QDs), Galβ1,4(Fucα1,3)GlcNAc-PC-QDs (Le(x)-PC-QDs), Neu5Acα2,3Galβ1,4GlcNAc-PC-QDs (sialyl LacNAc-PC-QDs), and Neu5Acα2,3Galβ1,4(Fucα1,3)GlcNAc-PC-QDs (sialyl Le(x)-PC-QDs) in

  20. Siglec-15, a member of the sialic acid-binding lectin, is a novel regulator for osteoclast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Hiruma, Yoshiharu, E-mail: hiruma.yoshiharu.hy@daiichisankyo.co.jp [Biological Research Laboratories, Daiichi Sankyo Co. Ltd., Tokyo 134-8630 (Japan); Hirai, Takehiro [Translational Medicine and Clinical Pharmacology Department, Daiichi Sankyo Co. Ltd., Tokyo 134-8630 (Japan); Tsuda, Eisuke [Biological Research Laboratories, Daiichi Sankyo Co. Ltd., Tokyo 134-8630 (Japan)

    2011-06-10

    Highlights: {yields} Siglec-15 was identified as a gene overexpressed in giant cell tumor. {yields} Siglec-15 mRNA expression increased in association with osteoclast differentiation. {yields} Polyclonal antibody to Siglec-15 inhibited osteoclast differentiation in vitro. -- Abstract: Osteoclasts are tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells derived from monocyte/macrophage-lineage precursors and are critically responsible for bone resorption. In giant cell tumor of bone (GCT), numerous TRAP-positive multinucleated giant cells emerge and severe osteolytic bone destruction occurs, implying that the emerged giant cells are biologically similar to osteoclasts. To identify novel genes involved in osteoclastogenesis, we searched genes whose expression pattern was significantly different in GCT from normal and other bone tumor tissues. By screening a human gene expression database, we identified sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) as one of the genes markedly overexpressed in GCT. The mRNA expression level of Siglec-15 increased in association with osteoclast differentiation in cultures of mouse primary unfractionated bone marrow cells (UBMC), RAW264.7 cells of the mouse macrophage cell line and human osteoclast precursors (OCP). Treatment with polyclonal antibody to mouse Siglec-15 markedly inhibited osteoclast differentiation in primary mouse bone marrow monocyte/macrophage (BMM) cells stimulated with receptor activator of nuclear factor {kappa}B ligand (RANKL) or tumor necrosis factor (TNF)-{alpha}. The antibody also inhibited osteoclast differentiation in cultures of mouse UBMC and RAW264.7 cells stimulated with active vitamin D{sub 3} and RANKL, respectively. Finally, treatment with polyclonal antibody to human Siglec-15 inhibited RANKL-induced TRAP-positive multinuclear cell formation in a human OCP culture. These results suggest that Siglec-15 plays an important role in osteoclast differentiation.

  1. Absence of hematological side effects in acute and subacute nasal dosing of erythropoietin with a low content of sialic acid.

    Science.gov (United States)

    Lagarto, Alicia; Bueno, Viviana; Guerra, Isbel; Valdés, Odalys; Couret, Micaela; López, Raisel; Vega, Yamile

    2011-09-01

    The use of human recombinant erythropoietin (EPO) as a neuroprotective agent is limited due to its hematological side effects. An erythropoietin along with a low content of sialic acid (rhEPOb), similar to that produced in the brain during hypoxia, may be used as a neuroprotective agent without risk of thrombotic events. The objective of this investigation was to assess the toxicological potential of a nasal formulation with rhEPOb in acute, subacute and nasal irritation assays in rats. Healthy Wistar rats (Cenp:Wistar) were used for the assays. In an irritation test, animals received 15 μl of rhEPOb into the right nostril. Rats were sacrificed after 24 h and slides of the nasal mucosa tissues were examined. Control and treated groups showed signs of a minimal irritation consisting of week edema and vascular congestion in all animals. In the acute toxicity test, the dose of 47,143 UI/kg was administered by nasal route. Hematological patterns, body weight, relative organ weight, and organ integrity were not affected by single dosing with rhEPOb. In the subacute toxicity test, Wistar rats of both sexes received 6,600 UI/kg/day for 14 days. The toxicological endpoints examined included animal body weight, food consumption, hematological and biochemical patterns, selected tissue weights, and histopathological examinations. An increase of lymphocytes was observed in males that was considered to reflect an immune response to treatment. Histopathological examination of organs and tissues did not reveal treatment-induced changes. The administration of rhEPOb at daily doses of 6,600 UI/kg during 14 days did not produce hematological side effects. These results suggest that rhEPOb could offer the same neuroprotection as EPO, without hematological side effects. Copyright © 2010 Elsevier GmbH. All rights reserved.

  2. Alveolar ridge augmentation by osteoinduction in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1990-01-01

    The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were...

  3. Applied Augmented Reality for High Precision Maintenance

    Science.gov (United States)

    Dever, Clark

    Augmented Reality had a major consumer breakthrough this year with Pokemon Go. The underlying technologies that made that app a success with gamers can be applied to improve the efficiency and efficacy of workers. This session will explore some of the use cases for augmented reality in an industrial environment. In doing so, the environmental impacts and human factors that must be considered will be explored. Additionally, the sensors, algorithms, and visualization techniques used to realize augmented reality will be discussed. The benefits of augmented reality solutions in industrial environments include automated data recording, improved quality assurance, reduction in training costs and improved mean-time-to-resolution. As technology continues to follow Moore's law, more applications will become feasible as performance-per-dollar increases across all system components.

  4. ARC Code TI: ROC Curve Code Augmentation

    Data.gov (United States)

    National Aeronautics and Space Administration — ROC (Receiver Operating Characteristic) curve Code Augmentation was written by Rodney Martin and John Stutz at NASA Ames Research Center and is a modification of ROC...

  5. Augmented Reality Simulations on Handheld Computers

    Science.gov (United States)

    Squire, Kurt; Klopfer, Eric

    2007-01-01

    Advancements in handheld computing, particularly its portability, social interactivity, context sensitivity, connectivity, and individuality, open new opportunities for immersive learning environments. This article articulates the pedagogical potential of augmented reality simulations in environmental engineering education by immersing students in…

  6. Affordances in Mobile Augmented Reality Applications

    Directory of Open Access Journals (Sweden)

    Tor Gjøsæter

    2014-10-01

    Full Text Available This paper explores the affordances of augmented reality content in a mobile augmented reality application. A user study was conducted by performing a multi-camera video recording of seven think aloud sessions. The think aloud sessions consisted of individual users performing tasks, exploring and experiencing a mobile augmented reality (MAR application we developed for the iOS platform named ARad. We discuss the instrumental affordances we observed when users interacted with augmented reality content, as well as more complex affordances rising from conventions from media content, AR and the traditional WIMP paradigm. We find that remediation of traditional newspaper content through the MAR medium can provide engaging, pleasing and exciting user experiences. However, the some of the content still suffers from being shoveled onto the MAR platform without adapting it properly. Finally, we discuss what content was most successfully mediated to the user and how the content impacts the user experience.

  7. Improved diffuser for augmenting a wind turbine

    Science.gov (United States)

    Foreman, K.M.; Gilbert, B.L.

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  8. Determination of student opinions in augmented reality

    OpenAIRE

    Huseyin Bicen; Erkan Bal

    2016-01-01

    The rapid development of the new technology has changed classroom teaching methods and tools in a positive way. This study investigated the classroom learning with augmented reality and the impact of student opinions. 97 volunteer undergraduate students took part in this study. Results included data in the form of frequencies, percentages and descriptive statistics. The results show that, with gamification methods, augmented reality content affected students’ opinions in a positive way. When ...

  9. Augmented monomials in terms of power sums.

    Science.gov (United States)

    Merca, Mircea

    2015-01-01

    The problem of base changes for the classical symmetric functions has been solved a long time ago and has been incorporated into most computer software packages for symmetric functions. In this paper, we develop a simple recursive formula for the expansion of the augmented monomial symmetric functions into power sum symmetric functions. As corollaries, we present two algorithms that can be used to expressing the augmented monomial symmetric functions in terms of the power sum symmetric functions.

  10. A Survey of Augmented Reality Navigation

    OpenAIRE

    Bhorkar, Gaurav

    2017-01-01

    Navigation has been a popular area of research in both academia and industry. Combined with maps, and different localization technologies, navigation systems have become robust and more usable. By combining navigation with augmented reality, it can be improved further to become realistic and user friendly. This paper surveys existing researches carried out in this area, describes existing techniques for building augmented reality navigation systems, and the problems faced.

  11. Augmented sport : exploring collective user experience

    OpenAIRE

    Pallot, Marc; EYNARD, Rémy; POUSSARD, Benjamin; CHRISTMANN, Olivier; Richir, Simon

    2013-01-01

    This paper explores existing theories, frameworks and models for handling collective user experience in the context of Distributed Interactive Multimedia Environments (DIME) and more specifically Augmented Sport applications. Besides discussing previous experimental work in the domain of Augmented Sport, we introduce Future Media Internet (FMI) technologies in relation with Mixed Reality (MR) platforms, user experience (UX), quality of Service (QoS) and quality of Experience (QoE) within 3D T...

  12. Visual Analysis and Filtering to Augment Cognition

    OpenAIRE

    Kölsch, Mathias; Wachs, Juan; Sadagic, Amela

    2013-01-01

    We built and demonstrated a system that augments instructors’ sensing abilities and augments their cognition through analysis and filtering of visual information. Called BASE-IT, our system helps US Marine instructors provide excellent training despite the challenging environment, hundreds of trainees and high trainee-to-instructor ratios, non-stop action, and diverse training objectives. To accomplish these objectives, BASE-IT widens the sensory input in multiple dimensions...

  13. Augmenting a guitar with its digital footprint

    OpenAIRE

    Benford, Steve; Hazzard, Adrian; Chamberlain, Alan; Xu, Liming

    2015-01-01

    We explore how to digitally augment musical instruments by connecting them to their social histories. We describe the use of Internet of Things technologies to connect an acoustic guitar to its digital footprint – a record of how it was designed, built and played. We introduce the approach of crafting interactive decorative inlay into the body of an instrument that can then be scanned using mobile devices to reveal its digital footprint. We describe the design and construction of an augmented...

  14. Augmented Reality Interfaces for Additive Manufacturing

    OpenAIRE

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Frisvad, Jeppe Revall; Skovmand, Linda; Heun, Valentin; Maes, Pattie; Aanæs, Henrik

    2017-01-01

    This paper explores potential use cases for using augmented reality (AR) as a tool to operate industrial machines. As a baseline we use an additive manufacturing system, more commonly known as a 3D printer. We implement novel augmented interfaces and controls using readily available open source frameworks and low cost hardware. Our results show that the technology enables richer and more intuitive printer control and performance monitoring than currently available on the market. Therefore, th...

  15. Augmenting the Web through Open Hypermedia

    DEFF Research Database (Denmark)

    Bouvin, N.O.

    2003-01-01

    Based on an overview of Web augmentation and detailing the three basic approaches to extend the hypermedia functionality of the Web, the author presents a general open hypermedia framework (the Arakne framework) to augment the Web. The aim is to provide users with the ability to link, annotate......, and otherwise structure Web pages, as they see fit. The paper further discusses the possibilities of the concept through the description of various experiments performed with an implementation of the framework, the Arakne Environment...

  16. Thrust augmentation for a small turbojet engine

    OpenAIRE

    Hackaday, Gary L.

    1999-01-01

    Approved for public release; distribution is unlimited A Sophia J450 (nine pounds of thrust) gas turbine engine was used first to examine the thrust augmentation generated using an ejector shroud. Experimental results obtained with and without the ejector were compared with performance predicted using an engine code and a one-dimensional ejector analysis. The engine code was revised to incorporate a radial turbine and the correct compressor map. Thrust augmentation of 3-10% was measured an...

  17. Augmented Reality for Maintenance and Repair (ARMAR)

    Science.gov (United States)

    2007-08-01

    of tracking and display technologies, and computer graphics hardware and software, and has a long tradition of research in AR theory and practice ... practice , a user can learn to negotiate the nearby augmented controls while keeping their eyes focused on the repair area. Second, because the...2005, pp. 47-54. [8] A. C. Boud, D. J. Haniff, C. Baber , and S. J. Steiner, "Virtual Reality and Augmented Reality as a Training Tool for

  18. Augmented reality implementation methods in mainstream applications

    Directory of Open Access Journals (Sweden)

    David Procházka

    2011-01-01

    Full Text Available Augmented reality has became an useful tool in many areas from space exploration to military applications. Although used theoretical principles are well known for almost a decade, the augmented reality is almost exclusively used in high budget solutions with a special hardware. However, in last few years we could see rising popularity of many projects focused on deployment of the augmented reality on dif­ferent mobile devices. Our article is aimed on developers who consider development of an augmented reality application for the mainstream market. Such developers will be forced to keep the application price, therefore also the development price, at reasonable level. Usage of existing image processing software library could bring a significant cut-down of the development costs. In the theoretical part of the article is presented an overview of the augmented reality application structure. Further, an approach for selection appropriate library as well as the review of the existing software libraries focused in this area is described. The last part of the article out­lines our implementation of key parts of the augmented reality application using the OpenCV library.

  19. Augmentation techniques for rotator cuff repair.

    Science.gov (United States)

    Papalia, Rocco; Franceschi, Francesco; Zampogna, Biagio; D'Adamio, Stefano; Maffulli, Nicola; Denaro, Vincenzo

    2013-01-01

    There is a high rate of recurrence of tear and failed healing after rotator cuff repair. Several strategies have proposed to augment rotator cuff repairs to improve postoperative outcome and shoulder performance. We systematically review the literature on clinical outcome following rotator cuff augmentation. We performed a comprehensive search of Medline, CINAHL, Embase and the Cochrane Central Registry of Controlled Trials, from inception of the database to 20 June 2012, using various combinations of keywords. The reference lists of the previously selected articles were then examined by hand. Only studies focusing on clinical outcomes of human patients who had undergone augmented rotator cuff repair were selected. We then evaluated the methodological quality of each article using the Coleman methodology score (CMS), a 10 criteria scoring list assessing the methodological quality of the selected studies (CMS). Thirty-two articles were included in the present review. Two were retrospective studies, and 30 were prospective. Biologic, synthetic and cellular devices were used in 24, 7 and 1 studies, respectively. The mean modified Coleman methodology score was 64.0. Heterogeneity of the clinical outcome scores makes it difficult to compare different studies. None of the augmentation devices available is without problems, and each one presents intrinsic weaknesses. There is no dramatic increase in clinical and functional assessment after augmented procedures, especially if compared with control groups. More and better scientific evidence is necessary to use augmentation of rotator cuff repairs in routine clinical practice.

  20. Horizontal bone augmentation: the decision tree.

    Science.gov (United States)

    Fu, Jia-Hui; Wang, Hom-Lay

    2011-01-01

    The emergence of implant dentistry has led to the need for bone augmentation procedures. With the removal of a tooth, there is an inevitable three-dimensional (3D) loss of alveolar bone. More often than not, horizontal bone loss occurs at a faster rate and to a greater extent compared to vertical bone loss. This led to the development of several horizontal bone augmentation techniques, such as guided bone regeneration, ridge expansion, distraction osteogenesis, and block grafts. These proposed augmentation techniques aim to place the implant in an ideal 3D position for successful restorative therapy. The literature has shown that horizontal bone augmentation is fairly predictable if certain criteria are fulfilled. However, with numerous techniques and materials currently available, it is difficult to choose the most suitable treatment modality. A search of the literature available was conducted to validate the decision-making process when planning for a horizontal ridge augmentation procedure. The decision tree proposed in this paper stems from the 3D buccolingual bone width available at the site of implant placement (⋝ 3.5 mm, factors such as the tissue thickness, the arch position, and the availability of autogenous bone. The decision tree provides insight on how clinicians can choose the most appropriate and predictable horizontal ridge augmentation procedure to minimize unnecessary complications.

  1. Empirical evaluation of augmented prototyping effectiveness

    Directory of Open Access Journals (Sweden)

    Tomáš Koubek

    2012-01-01

    Full Text Available Augmented reality is a scientific field well known for more than twenty years. Although there is a huge number of projects that present promising results, the real usage of augmented reality applications for fulfilling common tasks is almost negligible. We believe that one of the principal reasons is insufficient usability of these applications. The situation is analogous to the desktop, mobile or cloud application development or even to the web pages design. The first phase of a technology adoption is the exploration of its potential. As soon as the technical problems are overcome and the technology is widely accepted, the usability is a principal issue. The usability is utmost important also from the business point of view. The cost of augmented reality implementation into the production process is substantial, therefore, the usability that is directly responsible for the implemented solution effectiveness must be appropriately tested. Consequently, the benefit of the implemented solution can be measured.This article briefly outlines common techniques used for usability evaluation. Discussed techniques were designed especially for evaluation of desktop applications, mobile solutions and web pages. In spite of this drawback, their application on augmented reality products is usually possible. Further, a review of existing augmented reality project evaluations is presented.Based on this review, a usability evaluation method for our augmented prototyping application is proposed. This method must overcome the fact that the design is a creative process. Therefore, it is not possible to take into account common criteria such as time consumption.

  2. Augmenting digital displays with computation

    Science.gov (United States)

    Liu, Jing

    As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

  3. ARSC: Augmented Reality Student Card--An Augmented Reality Solution for the Education Field

    Science.gov (United States)

    El Sayed, Neven A. M.; Zayed, Hala H.; Sharawy, Mohamed I.

    2011-01-01

    Augmented Reality (AR) is the technology of adding virtual objects to real scenes through enabling the addition of missing information in real life. As the lack of resources is a problem that can be solved through AR, this paper presents and explains the usage of AR technology we introduce Augmented Reality Student Card (ARSC) as an application of…

  4. Augmented Reality for the Improvement of Remote Laboratories: An Augmented Remote Laboratory

    Science.gov (United States)

    Andujar, J. M.; Mejias, A.; Marquez, M. A.

    2011-01-01

    Augmented reality (AR) provides huge opportunities for online teaching in science and engineering, as these disciplines place emphasis on practical training and unsuited to completely nonclassroom training. This paper proposes a new concept in virtual and remote laboratories: the augmented remote laboratory (ARL). ARL is being tested in the first…

  5. Augmented “Ouch!”. : How to create intersubjective augmented objects into which we can bump

    NARCIS (Netherlands)

    Liberati, Nicola

    2015-01-01

    The aim of this work is to provide the elements to design an intersubjective augmented reality in order to make the augmented objects part of our everyday world. This work will analyse intersubjectivity from a phenomenological point of view using the works by Husserl and Schutz. Thanks to these two

  6. Augmented reality and ubiquitous computing : The hidden potentialities of augmented reality

    NARCIS (Netherlands)

    Liberati, Nicola

    2016-01-01

    The aim of this paper was to highlight the augmented reality’s potentialities, depicting its main characteristics and focusing attention on what its goal should be in order to have a new technology completely different from those that already exist. From a technological point of view, augmented

  7. Utilizing CMP-Sialic Acid Analogs to Unravel Neisseria gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance and Design Novel Therapeutics.

    Directory of Open Access Journals (Sweden)

    Sunita Gulati

    2015-12-01

    Full Text Available Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT structure of lipooligosaccharide (LOS is capped by the bacterial sialyltransferase, using host cytidine-5'-monophosphate (CMP-activated forms of the nine-carbon nonulosonate (NulO sugar N-acetyl-neuraminic acid (Neu5Ac, a sialic acid (Sia abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH, an inhibitor of the alternative complement pathway, and by limiting classical pathway activation ("serum-resistance". We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac and pseudaminic acid (Pse5Ac7Ac, to define structural requirements of Sia-mediated serum-resistance. While all NulOs except Pse5Ac7Ac were incorporated into the LNnT-LOS, only Neu5Gc incorporation yielded high-level serum-resistance and FH binding that was comparable to Neu5Ac, whereas Neu5Ac9Az and Leg5Ac7Ac incorporation left bacteria fully serum-sensitive and did not enhance FH binding. Neu5Ac9Ac and Neu5Gc8Me rendered bacteria resistant only to low serum concentrations. While serum-resistance mediated by Neu5Ac was associated with classical pathway inhibition (decreased IgG binding and C4 deposition, Leg5Ac7Ac and Neu5Ac9Az incorporation did not inhibit the classical pathway. Remarkably, CMP-Neu5Ac9Az and CMP-Leg5Ac7Ac each prevented serum-resistance despite a 100-fold molar excess of CMP-Neu5Ac in growth media. The concomitant presence of Leg5Ac7Ac and Neu5Ac on LOS resulted in uninhibited classical pathway activation. Surprisingly, despite near-maximal FH binding in this instance, the alternative pathway was not regulated and factor Bb remained associated with bacteria. Intravaginal administration of CMP-Leg5Ac7Ac to BALB/c mice infected with gonorrhea (including a multidrug-resistant isolate reduced clearance times and infection burden. Bacteria recovered

  8. Utilizing CMP-Sialic Acid Analogs to Unravel Neisseria gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance and Design Novel Therapeutics.

    Science.gov (United States)

    Gulati, Sunita; Schoenhofen, Ian C; Whitfield, Dennis M; Cox, Andrew D; Li, Jianjun; St Michael, Frank; Vinogradov, Evgeny V; Stupak, Jacek; Zheng, Bo; Ohnishi, Makoto; Unemo, Magnus; Lewis, Lisa A; Taylor, Rachel E; Landig, Corinna S; Diaz, Sandra; Reed, George W; Varki, Ajit; Rice, Peter A; Ram, Sanjay

    2015-12-01

    Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT) structure of lipooligosaccharide (LOS) is capped by the bacterial sialyltransferase, using host cytidine-5'-monophosphate (CMP)-activated forms of the nine-carbon nonulosonate (NulO) sugar N-acetyl-neuraminic acid (Neu5Ac), a sialic acid (Sia) abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH), an inhibitor of the alternative complement pathway, and by limiting classical pathway activation ("serum-resistance"). We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac) and pseudaminic acid (Pse5Ac7Ac), to define structural requirements of Sia-mediated serum-resistance. While all NulOs except Pse5Ac7Ac were incorporated into the LNnT-LOS, only Neu5Gc incorporation yielded high-level serum-resistance and FH binding that was comparable to Neu5Ac, whereas Neu5Ac9Az and Leg5Ac7Ac incorporation left bacteria fully serum-sensitive and did not enhance FH binding. Neu5Ac9Ac and Neu5Gc8Me rendered bacteria resistant only to low serum concentrations. While serum-resistance mediated by Neu5Ac was associated with classical pathway inhibition (decreased IgG binding and C4 deposition), Leg5Ac7Ac and Neu5Ac9Az incorporation did not inhibit the classical pathway. Remarkably, CMP-Neu5Ac9Az and CMP-Leg5Ac7Ac each prevented serum-resistance despite a 100-fold molar excess of CMP-Neu5Ac in growth media. The concomitant presence of Leg5Ac7Ac and Neu5Ac on LOS resulted in uninhibited classical pathway activation. Surprisingly, despite near-maximal FH binding in this instance, the alternative pathway was not regulated and factor Bb remained associated with bacteria. Intravaginal administration of CMP-Leg5Ac7Ac to BALB/c mice infected with gonorrhea (including a multidrug-resistant isolate) reduced clearance times and infection burden. Bacteria recovered from CMP

  9. Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs

    Directory of Open Access Journals (Sweden)

    Viuff Birgitte M

    2011-09-01

    Full Text Available Abstract Background Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SA-alpha-2,3 and swine/human (SA-alpha-2,6 influenza viruses in the upper respiratory tract. Furthermore, experimental and natural infections in pigs have been reported with influenza A virus from avian and human sources. Methods This study investigated the receptor distribution in the entire respiratory tract of pigs using specific lectins Maackia Amurensis (MAA I, and II, and Sambucus Nigra (SNA. Furthermore, the predilection sites of swine influenza virus (SIV subtypes H1N1 and H1N2 as well as avian influenza virus (AIV subtype H4N6 were investigated in the respiratory tract of experimentally infected pigs using immunohistochemical methods. Results SIV antigen was widely distributed in bronchi, but was also present in epithelial cells of the nose, trachea, bronchioles, and alveolar type I and II epithelial cells in severely affected animals. AIV was found in the lower respiratory tract, especially in alveolar type II epithelial cells and occasionally in bronchiolar epithelial cells. SA-alpha-2,6 was the predominant receptor in all areas of the respiratory tract with an average of 80-100% lining at the epithelial cells. On the contrary, the SA-alpha-2,3 was not present (0% at epithelial cells of nose, trachea, and most bronchi, but was found in small amounts in bronchioles, and in alveoli reaching an average of 20-40% at the epithelial cells. Interestingly, the receptor expression of both SA-alpha-2,3 and 2,6 was markedly diminished in influenza infected areas compared to non-infected areas. Conclusions A difference in predilection sites between SIV and AIV virus was found, and this difference was in accordance with the distribution of the SA-alpha-2,6 and SA-alpha-2,3 receptor, respectively. The results indicated

  10. Comparison of the nature of interactions of two sialic acid specific lectins Saraca indica and Sambucus nigra with N-acetylneuraminic acid by spectroscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Singha, Shuvendu [Department of Natural Science, West Bengal University of Technology, Kolkata 700064 (India); Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700032 (India); Bose, Partha P. [Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844101 (India); Ganguly, Tapan [School of Laser Science and Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Campana, Patricia T. [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, 03828-000 São Paulo (Brazil); Ghosh, Rina [Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700032 (India); Chatterjee, Bishnu P., E-mail: cbishnup@gmail.com [Department of Natural Science, West Bengal University of Technology, Kolkata 700064 (India)

    2015-04-15

    The present paper deals with the isolation and purification of a new sialic acid binding lectin from the seed integument of Saraca indica (Ashok) and the purified lectin was designated Saracin II. Comparative studies on the interactions of saracin II and another sialic acid specific lectin Sambucus nigra agglutinin (SNA) with N-acetylneuraminic acid (NANA) were made using UV–vis absorption, steady state and time resolved fluorescence along with circular dichroism (CD) spectroscopy to reveal the nature and mechanisms of binding of these two lectins with NANA. The experimental observations obtained from UV–vis, steady state and time resolved fluorescence measurements demonstrated that SNA–NANA system formed relatively stronger ground state complex than saracin II–NANA pair. CD measurements further substantiated the propositions made from steady state and time resolved spectroscopic investigations. It was inferred that during interaction of SNA with NANA, the lectin adopted a relatively looser conformation with the extended polypeptide structures leading to the exposure of the hydrophobic cavities which favoured stronger binding with NANA. - Highlights: • Of the two lectins, stronger binding of SNA with NANA is observed. • Full exposure of the hydrophobic cavities of SNA favors the stronger interactions. • Saracin II can be used for the new generation of lectin based-therapeutics.

  11. Handling Occlusions for Robust Augmented Reality Systems

    Directory of Open Access Journals (Sweden)

    Madjid Maidi

    2010-01-01

    Full Text Available In Augmented Reality applications, the human perception is enhanced with computer-generated graphics. These graphics must be exactly registered to real objects in the scene and this requires an effective Augmented Reality system to track the user's viewpoint. In this paper, a robust tracking algorithm based on coded fiducials is presented. Square targets are identified and pose parameters are computed using a hybrid approach based on a direct method combined with the Kalman filter. An important factor for providing a robust Augmented Reality system is the correct handling of targets occlusions by real scene elements. To overcome tracking failure due to occlusions, we extend our method using an optical flow approach to track visible points and maintain virtual graphics overlaying when targets are not identified. Our proposed real-time algorithm is tested with different camera viewpoints under various image conditions and shows to be accurate and robust.

  12. Formwork application optimization by using augmented reality

    Science.gov (United States)

    Diaconu, R.; Petruse, R.; Brindasu, P. D.

    2016-11-01

    By using the PLM (Product Lifecycle Management) principle on the formwork case study, after determining the functions and the technical solutions, the application must be made as optimum as possible in order to assure productivity and provide the necessary information as quick as possible. The concept is to create a complex management for the formwork based on augmented reality. By taking into account the development rate of the information, augmented reality is tending to be one of the widest (in term of domain) visualization instrument. Also used in the construction domain, augmented reality can be applied also for the case of formwork design and management. The application of the solution will be retrieved in the construction of the product, its transportation and deposit. The usage of this concept will help reduce, even eliminate human or technical errors and can offer a precise state of a specific required formwork from the stock.

  13. Therapeutics: Alpha-1 Antitrypsin Augmentation Therapy.

    Science.gov (United States)

    Campos, Michael; Lascano, Jorge

    2017-01-01

    Subjects with alpha-1 antitrypsin deficiency who develop pulmonary disease are managed following general treatment guidelines, including disease management interventions. In addition, administration of intravenous infusions of alpha-1 proteinase inhibitor (augmentation therapy) at regular schedules is a specific therapy for individuals with AATD with pulmonary involvement.This chapter summarizes the manufacturing differences of commercially available formulations and the available evidence of the effects of augmentation therapy. Biologically, there is clear evidence of in vivo local antiprotease effects in the lung and systemic immunomodulatory effects. Clinically, there is cumulative evidence of slowing lung function decline and emphysema progression. The optimal dose of augmentation therapy is being revised as well as more individualized assessment of who needs this therapy.

  14. Handling Occlusions for Robust Augmented Reality Systems

    Directory of Open Access Journals (Sweden)

    Maidi Madjid

    2010-01-01

    Full Text Available Abstract In Augmented Reality applications, the human perception is enhanced with computer-generated graphics. These graphics must be exactly registered to real objects in the scene and this requires an effective Augmented Reality system to track the user's viewpoint. In this paper, a robust tracking algorithm based on coded fiducials is presented. Square targets are identified and pose parameters are computed using a hybrid approach based on a direct method combined with the Kalman filter. An important factor for providing a robust Augmented Reality system is the correct handling of targets occlusions by real scene elements. To overcome tracking failure due to occlusions, we extend our method using an optical flow approach to track visible points and maintain virtual graphics overlaying when targets are not identified. Our proposed real-time algorithm is tested with different camera viewpoints under various image conditions and shows to be accurate and robust.

  15. Pemanfaatan Augmented Reality Pada Permainan Othello

    Directory of Open Access Journals (Sweden)

    Rendy Layman Aguston

    2016-11-01

    Full Text Available Perkembangan teknologi telah mengubah cara pengerjaan suatu pekerjaan dari cara konvensional menjadi cara yang lebih praktis. Dengan hadirnya teknologi Augmented Reality, cara bermain yang menggunakan pion dan membalikkan pion musuh secara manual menjadi lebih mudah dalam memainkan permainan selain juga dapat berinteraksi langsung. Pembuatan permainan Othello menggunakan program Unity dengan framework Vuforia untuk mewujudkan Augmented Reality pada permainan Othello. Untuk menerapkan Augmented Reality dengan baik, dibutuhkan papan permainan sebagai image target yang sesuai dengan kriteria, jenis kamera yang digunakan, jarak kamera terhadap papan permainan, intensitas cahaya yang ditangkap kamera, serta tingkat sensitivitas tombol virtual. Pada permainan Othello ini tersedia fitur komputer yang menggunakan algoritma Alpha Beta Pruning dengan 3 level kedalaman yang menggunakan perhitungan fungsi evaluasi berupa mobility, potential mobility dan penguasaan corner yang menghasilkan kemenangan mencapai 73,33% dari 15 kali uji coba terhadap aplikasi Othello serupa dan 78,34% dari 37 kali uji coba terhadap user.

  16. Augmented reality-assisted skull base surgery.

    Science.gov (United States)

    Cabrilo, I; Sarrafzadeh, A; Bijlenga, P; Landis, B N; Schaller, K

    2014-12-01

    Neuronavigation is widely considered as a valuable tool during skull base surgery. Advances in neuronavigation technology, with the integration of augmented reality, present advantages over traditional point-based neuronavigation. However, this development has not yet made its way into routine surgical practice, possibly due to a lack of acquaintance with these systems. In this report, we illustrate the usefulness and easy application of augmented reality-based neuronavigation through a case example of a patient with a clivus chordoma. We also demonstrate how augmented reality can help throughout all phases of a skull base procedure, from the verification of neuronavigation accuracy to intraoperative image-guidance. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Cognitive Cost of Using Augmented Reality Displays.

    Science.gov (United States)

    Baumeister, James; Ssin, Seung Youb; ElSayed, Neven A M; Dorrian, Jillian; Webb, David P; Walsh, James A; Simon, Timothy M; Irlitti, Andrew; Smith, Ross T; Kohler, Mark; Thomas, Bruce H

    2017-11-01

    This paper presents the results of two cognitive load studies comparing three augmented reality display technologies: spatial augmented reality, the optical see-through Microsoft HoloLens, and the video see-through Samsung Gear VR. In particular, the two experiments focused on isolating the cognitive load cost of receiving instructions for a button-pressing procedural task. The studies employed a self-assessment cognitive load methodology, as well as an additional dual-task cognitive load methodology. The results showed that spatial augmented reality led to increased performance and reduced cognitive load. Additionally, it was discovered that a limited field of view can introduce increased cognitive load requirements. The findings suggest that some of the inherent restrictions of head-mounted displays materialize as increased user cognitive load.

  18. Resonance frequency analysis of implant stability in augmented and non-augmented sinus sites

    Directory of Open Access Journals (Sweden)

    Amir Moeintaghavi

    2015-12-01

    Full Text Available Background and aim:  Although there have been substantial developments in dental implant therapies, achieving good implant stability (ISQ >60 for implants inserted in augmented sinus sites appears to be challenging in comparison with non-augmented sites due to the high prevalence of bone resorption in posterior regions of maxilla. This study aimed to evaluate and compare the time required to achieve good implant stability between implants inserted in sites that had undergone a sinus augmentation procedure with implants inserted in non-augmented similar regions of maxilla. Methods: Thirty Stroman ITI Dental Implants were inserted in 14 patients (8 females and 6 males with average age of 55 ± 10 years. Fourteen implants were inserted in sinus augmented sites (open sinus elevation and Demineralized Freezed Bone Allograft  or DFDBA 6 months after healing (test group, and 16 implants were inserted into non-augmented  posterior areas of maxilla (control group. The implant stability quotient (ISQ for each implant was measured at the time of insertion (baseline, ISQ0 and at 1, 2 and 3 months later (ISQ1, ISQ2, ISQ3. Residual and augmented bone heights were also recorded. Results: The average residual bone height was 2.92 ± 0.63mm and 10.41 ± 1.46mm for the augmented bone height. The difference between ISQ values in the test and control groups was only significant at the baseline (p=0.023. No significant correlation was found between ISQ and bone height (residual and augmented, and there was no significant correlation between ISQ values and the implant diameter and length. In the test group, the differences between ISQ0 and ISQ1, ISQ1 and ISQ3 and ISQ2 and ISQ3 were all statistically significant (p=0.006, p=0.032, p=0.046. In the control group, the difference was only significant between ISQ0 and ISQ1 (p=0.002. Conclusion:  ISQ values were not statistically significant between implants inserted in natural and augmented bone six months after sinus

  19. Resonance frequency analysis of implant stability in augmented and non-augmented sinus sites

    Directory of Open Access Journals (Sweden)

    Amir Moeintaghavi

    2016-03-01

    Full Text Available Background and aim:  Although there have been substantial developments in dental implant therapies, achieving good implant stability (ISQ >60 for implants inserted in augmented sinus sites appears to be challenging in comparison with non-augmented sites due to the high prevalence of bone resorption in posterior regions of maxilla. This study aimed to evaluate and compare the time required to achieve good implant stability between implants inserted in sites that had undergone a sinus augmentation procedure with implants inserted in non-augmented similar regions of maxilla. Methods: Thirty Stroman ITI Dental Implants were inserted in 14 patients (8 females and 6 males with average age of 55 ± 10 years. Fourteen implants were inserted in sinus augmented sites (open sinus elevation and Demineralized Freezed Bone Allograft  or DFDBA 6 months after healing (test group, and 16 implants were inserted into non-augmented  posterior areas of maxilla (control group. The implant stability quotient (ISQ for each implant was measured at the time of insertion (baseline, ISQ0 and at 1, 2 and 3 months later (ISQ1, ISQ2, ISQ3. Residual and augmented bone heights were also recorded. Results: The average residual bone height was 2.92 ± 0.63mm and 10.41 ± 1.46mm for the augmented bone height. The difference between ISQ values in the test and control groups was only significant at the baseline (p=0.023. No significant correlation was found between ISQ and bone height (residual and augmented, and there was no significant correlation between ISQ values and the implant diameter and length. In the test group, the differences between ISQ0 and ISQ1, ISQ1 and ISQ3 and ISQ2 and ISQ3 were all statistically significant (p=0.006, p=0.032, p=0.046. In the control group, the difference was only significant between ISQ0 and ISQ1 (p=0.002. Conclusion:  ISQ values were not statistically significant between implants inserted in natural and augmented bone six months after sinus

  20. Gluteal Augmentation Techniques: A Comprehensive Literature Review.

    Science.gov (United States)

    Oranges, Carlo M; Tremp, Mathias; di Summa, Pietro G; Haug, Martin; Kalbermatten, Daniel F; Harder, Yves; Schaefer, Dirk J

    2017-05-01

    Many studies of gluteal augmentation techniques have been published in recent decades, including case reports, retrospective and prospective case series, and multicenter survey reviews. However, to date, there has been no study of the overall complications or satisfaction rates associated with the broad spectrum of techniques. The authors performed a comprehensive literature review to determine outcomes and complications of gluteoplasty techniques, including patient satisfaction. A search on PubMed/Medline was performed for clinical studies involving gluteal augmentation techniques. A priori criteria were used to review the resulting articles. Fifty-two studies, published from 1969 through 2015, were included - representing 7834 treated patients. Five gluteal augmentation techniques were identified from these studies: gluteal augmentation with implants (n = 4781), autologous fat grafting (n = 2609), local flaps (n = 369), hyaluronic acid gel injection (n = 69), and local tissue rearrangement (n = 6). The overall complication rates of the most commonly utilized techniques were: 30.5% for gluteal augmentation with implants, 10.5% for autologous fat grafting, and 22% for local flaps. Patients' satisfaction was reported as consistently high for all the five techniques. Implant-based gluteal augmentation is associated with high patients' satisfaction despite a high complication rate, while autologous fat grafting is associated with the lowest complication rate yet including serious major complications such as fat embolism. Local flaps and local tissue rearrangements are the ideal procedures in case of massive weight loss patients. A paucity of data is available for hyaluronic acid gel injections, which appear to be effective but temporary and expensive.

  1. Guidelines for designing augmented reality games

    OpenAIRE

    Wetzel, Richard; McCall, Rod; Braun, Anne-Kathrin; Broll, Wolfgang

    2008-01-01

    The growing popularity of augmented reality (AR) games in both a research and more recently commercial context has led for a need to take a closer look at design related issues which impact on player experience. While issues relating to this area have been considered, to date most of the emphasis has been on the technology aspects. Furthermore it is almost always assumed that the augmented reality element in itself will provide a sufficient experience for the player. This has led to a need to...

  2. Comparison between intact and desialylated human serum amyloid P component by laser photo CIDNP (chemically induced dynamic nuclear polarization) technique: an indication for a conformational impact of sialic acid

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Siebert, H.-C; André, S.; Reuter, G.; Kaptein, R.; Gabius, H.-J.

    1997-01-01

    The human pentraxin serum amyloid P component (SAP) exhibits no microheterogeneity in its complex di-antennary glycan. To elucidate whether the removal of sialic acids from this glycoprotein might affect the accessibility of certain amino acid residues of the protein we employed the laser photo

  3. Post-Training Intrahippocampal Injection of Synthetic Poly-Alpha-2,8-Sialic Acid-Neural Cell Adhesion Molecule Mimetic Peptide Improves Spatial Long-Term Performance in Mice

    Science.gov (United States)

    Florian, Cedrick; Foltz, Jane; Norreel, Jean-Chretien; Rougon, Genevieve; Roullet, Pascal

    2006-01-01

    Several data have shown that the neural cell adhesion molecule (NCAM) is necessary for long-term memory formation and might play a role in the structural reorganization of synapses. The NCAM, encoded by a single gene, is represented by several isoforms that differ with regard to their content of alpha-2,8-linked sialic acid residues (PSA) on their…

  4. Role of sialic acid for platelet life span: exposure of beta-galactose results in the rapid clearance of platelets from the circulation by asialoglycoprotein receptor-expressing liver macrophages and hepatocytes

    DEFF Research Database (Denmark)

    Sørensen, Anne Louise; Rumjantseva, Viktoria; Nayeb-Hashemi, Sara

    2009-01-01

    Although surface sialic acid is considered a key determinant for the survival of circulating blood cells and glycoproteins, its role in platelet circulation lifetime is not fully clarified. We show that thrombocytopenia in mice deficient in the St3gal4 sialyltransferase gene (St3Gal-IV(-/-) mice)...

  5. Understanding the Conics through Augmented Reality

    Science.gov (United States)

    Salinas, Patricia; Pulido, Ricardo

    2017-01-01

    This paper discusses the production of a digital environment to foster the learning of conics through augmented reality. The name conic refers to curves obtained by the intersection of a plane with a right circular conical surface. The environment gives students the opportunity to interact with the cone and the plane as virtual objects in real…

  6. Get Real: Augmented Reality for the Classroom

    Science.gov (United States)

    Mitchell, Rebecca; DeBay, Dennis

    2012-01-01

    Kids love augmented reality (AR) simulations because they are like real-life video games. AR simulations allow students to learn content while collaborating face to face and interacting with a multimedia-enhanced version of the world around them. Although the technology may seem advanced, AR software makes it easy to develop content-based…

  7. Augmentation ureterocystoplasty: is it the preferred choice ...

    African Journals Online (AJOL)

    Objective: To evaluate our experience with ureterocystoplasty as to whether it is the preferred method for bladder augmentation to achieve continence and preserve the upper urinary tract. Design: Retrospective study. Setting: Paediatric urology unit, Dana Children\\'s hospital, Tel Aviv Medical Center (affiliated to the Sackler ...

  8. Augmentation ureterocystoplasty: is it the preferred choice ...

    African Journals Online (AJOL)

    The urinary bladder in all patients is spherical with good capacity and no vesicoureteral reflux was demonstrated. The upper urinary tracts are stable and the renal function tests are normal. Conclusion: Ureterocystoplasty is our preferred choice of bladder augmentation in patients with small, inelastic, poor compliant bladder ...

  9. Augmented Lagrangian Method For Discretized Optimal Control ...

    African Journals Online (AJOL)

    With the aid of Augmented Lagrangian method, a quadratic function with a control operator (penalized matrix) amenable to conjugate gradient method is generated. Numerical experiments verify the efficiency of the proposed technique which compares much more favourably to the existing scheme. Keywords: Trapezoidal ...

  10. Toward natural fiducials for augmented reality

    Science.gov (United States)

    Kitchin, Paul; Martinez, Kirk

    2005-03-01

    Augmented Reality (AR) requires a mapping between the camera(s) and the world, so that virtual objects can be correctly registered. Current AR applications either use pre-prepared fiducial markers or specialist equipment or impose significant constraints on lighting and background. Each of these approaches has significant drawbacks. Fiducial markers are susceptible to loss or damage, can be awkward to work with and may require significant effort to prepare an area for Augmented interaction. Use of such markers may also present an imposition to non-augmented observers, especially in environments such as museums or historical landmarks. Specialist equipment is expensive and not universally available. Lighting and background constraints are often impractical for real-world applications. This paper presents initial results in using the palm of the hand as a pseudo-fiducial marker in a natural real-world environment, through colour, feature and edge analysis. The eventual aim of this research is to enable fiducial marker cards to be dispensed with entirely in some situations in order to allow more natural interaction in Augmented environments. Examples of this would be allowing users to "hold" virtual 3D objects in the palm of their hand or use gestures to interact with virtual objects.

  11. Aplikasi Museum Zoologi Berbasis Augmented Reality

    OpenAIRE

    Gonydjaja, Rosny; Mayongga, Yongki

    2014-01-01

    Museum Zoologi adalah museum yang terletak di kota Bogor, yang memilikikoleksi yang berkaitan dengan dunia satwa dari berbagai spesimen yangdiawetkan maupun fosil hewan. Pada awal pembangunannya tahun 1894,tempat ini berfungsi sebagai laboratorium zoologi yang menjadi wadahpenelitian yang berkaitan dengan pertanian dan zoologi, meliputi kegiataninventarisasi fauna Indonesia dengan nama Landbouw ZoologischLaboratorium. Augmented reality (AR) adalah sebuah lingkungan yangmenggabungkan dunia nya...

  12. (Re-)Examination of Multimodal Augmented Reality

    NARCIS (Netherlands)

    Rosa, N.E.; Werkhoven, P.J.; Hürst, W.O.

    2016-01-01

    The majority of augmented reality (AR) research has been concerned with visual perception, however the move towards multimodality is imminent. At the same time, there is no clear vision of what multimodal AR is. The purpose of this position paper is to consider possible ways of examining AR other

  13. Augmented Reality in Sports: Today and Tomorrow

    Directory of Open Access Journals (Sweden)

    Zafer BOZYER

    2015-08-01

    Full Text Available The rapid change experienced in the field of Information Technologies makes the informati cs more tangible in daily life. Today, it became possible to encounter with the informatics applications almost all the disciplines. As a matter of course, many informatics applications are put into the practice regarding the sports discipline. Because of the condition that the power of information processing has increased and the studies on wearable technol ogies in addition to the expert system design, augmented reality (AR has become a topic which gains imp ortance in the field of sports. There are many studies that are conducted with the aim of increasing the efficiency of physical activities done in many sports branches, ensuring a more fair management of competitions and providing the opportunity for spectators to watch the competitions in a more comfortable and efficient way. In this study; the information about the current augmented reality practices th at are used in various sports branches has been given and the mobile and interactive augmented reality practices which are possible to be seen in future have been mentioned. In addition, there is an augmented reality practice which is designed with the aim of ensuring that the shoots of sports people who are interested in archery, are more stable and of ensuring that the trainings and exercises are more efficient by stating to the sports people whether he or she is in the right position for shoot which is c alled as T shape seen at the time of releasing the arrow.

  14. Some augmentation quotients of integral group rings

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    Some augmentation quotients of integral group rings. DEEPAK KUMAR GUMBER1, RAM KARAN2 and INDU PAL2. 1School of Mathematics and Computer Applications, Thapar University,. Patiala 147 004, India. 2Department of Mathematics, Kurukshetra University, Kurukshetra 136 119, India. E-mail: dkgumber@yahoo.

  15. Augmentation of board games using smartphones

    DEFF Research Database (Denmark)

    Kulsinskas, Arturas; Balan, Catalin; Egede Bukdahl, Nicholas

    2015-01-01

    This paper contains details about research into the effect of digital augmentation on social presence in board games. A case study of the board game Tobago was performed during the project and a prototype application for smartphones was developed in order to compare the players’ social presence...

  16. Determination of Student Opinions in Augmented Reality

    Science.gov (United States)

    Bicen, Huseyin; Bal, Erkan

    2016-01-01

    The rapid development of the new technology has changed classroom teaching methods and tools in a positive way. This study investigated the classroom learning with augmented reality and the impact of student opinions. 97 volunteer undergraduate students took part in this study. Results included data in the form of frequencies, percentages and…

  17. CARE: Creating Augmented Reality in Education

    Science.gov (United States)

    Latif, Farzana

    2012-01-01

    This paper explores how Augmented Reality using mobile phones can enhance teaching and learning in education. It specifically examines its application in two cases, where it is identified that the agility of mobile devices and the ability to overlay context specific resources offers opportunities to enhance learning that would not otherwise exist.…

  18. Location-Based Learning through Augmented Reality

    Science.gov (United States)

    Chou, Te-Lien; Chanlin, Lih-Juan

    2014-01-01

    A context-aware and mixed-reality exploring tool cannot only effectively provide an information-rich environment to users, but also allows them to quickly utilize useful resources and enhance environment awareness. This study integrates Augmented Reality (AR) technology into smartphones to create a stimulating learning experience at a university…

  19. Design Principles for Augmented Reality Learning

    Science.gov (United States)

    Dunleavy, Matt

    2014-01-01

    Augmented reality is an emerging technology that utilizes mobile, context-aware devices (e.g., smartphones, tablets) that enable participants to interact with digital information embedded within the physical environment. This overview of design principles focuses on specific strategies that instructional designers can use to develop AR learning…

  20. The Educational Possibilities of Augmented Reality

    Science.gov (United States)

    Cabero, Julio; Barroso, Julio

    2016-01-01

    A large number of emergent technologies have been acquiring a strong impulse in recent years. One of these emergent technologies is Augmented Reality (RA), which will surely have a high level of penetration into all our educational centers, including universities, in the next 3 to 5 years, as a number of different reports have already highlighted.…

  1. Temporal Coherence Strategies for Augmented Reality Labeling

    DEFF Research Database (Denmark)

    Madsen, Jacob Boesen; Tatzgern, Markus; Madsen, Claus B.

    2016-01-01

    Temporal coherence of annotations is an important factor in augmented reality user interfaces and for information visualization. In this paper, we empirically evaluate four different techniques for annotation. Based on these findings, we follow up with subjective evaluations in a second experiment...

  2. Intelligent Augmented Reality Training for Motherboard Assembly

    Science.gov (United States)

    Westerfield, Giles; Mitrovic, Antonija; Billinghurst, Mark

    2015-01-01

    We investigate the combination of Augmented Reality (AR) with Intelligent Tutoring Systems (ITS) to assist with training for manual assembly tasks. Our approach combines AR graphics with adaptive guidance from the ITS to provide a more effective learning experience. We have developed a modular software framework for intelligent AR training…

  3. Design Patterns for Augmented Reality Learning Games

    NARCIS (Netherlands)

    Emmerich, Felix; Klemke, Roland; Hummes, Thomas

    2017-01-01

    Augmented Reality (AR) is expected to receive a major uptake with the recent availability of high quality wearable AR devices such as Microsoft’s Hololens. However, the design of interaction with AR applications and games is still a field of experimentation and upcoming innovations in

  4. Design Patterns for Augmented Reality Learning Games

    NARCIS (Netherlands)

    Emmerich, Felix; Klemke, Roland; Hummes, Thomas

    2017-01-01

    Augmented Reality (AR) is expected to receive a major uptake with the recent availability of high quality wearable AR devices such as Microsoft’s Hololens. However, the design of interaction with AR applications and games is still a field of experimentation and upcoming innovations in sensor

  5. Accurate overlaying for mobile augmented reality

    NARCIS (Netherlands)

    Pasman, W; van der Schaaf, A; Lagendijk, RL; Jansen, F.W.

    1999-01-01

    Mobile augmented reality requires accurate alignment of virtual information with objects visible in the real world. We describe a system for mobile communications to be developed to meet these strict alignment criteria using a combination of computer vision. inertial tracking and low-latency

  6. Aloqa and layar augmented reality feeds

    NARCIS (Netherlands)

    Ternier, Stefaan

    2010-01-01

    Aloqa is a service that proactively notifies the user of Point Of Interests (POIs). It runs on iPhone, blackberry and android. With this tool you can easily get directions to events, places, buildings or other places of interests. Layar builds on the same principle, but has a browser that augments

  7. Personalized augmented reality for anatomy education.

    Science.gov (United States)

    Ma, Meng; Fallavollita, Pascal; Seelbach, Ina; Von Der Heide, Anna Maria; Euler, Ekkehard; Waschke, Jens; Navab, Nassir

    2016-05-01

    Anatomy education is a challenging but vital element in forming future medical professionals. In this work, a personalized and interactive augmented reality system is developed to facilitate education. This system behaves as a "magic mirror" which allows personalized in-situ visualization of anatomy on the user's body. Real-time volume visualization of a CT dataset creates the illusion that the user can look inside their body. The system comprises a RGB-D sensor as a real-time tracking device to detect the user moving in front of a display. In addition, the magic mirror system shows text information, medical images, and 3D models of organs that the user can interact with. Through the participation of 7 clinicians and 72 students, two user studies were designed to respectively assess the precision and acceptability of the magic mirror system for education. The results of the first study demonstrated that the average precision of the augmented reality overlay on the user body was 0.96 cm, while the results of the second study indicate 86.1% approval for the educational value of the magic mirror, and 91.7% approval for the augmented reality capability of displaying organs in three dimensions. The usefulness of this unique type of personalized augmented reality technology has been demonstrated in this paper. © 2015 Wiley Periodicals, Inc.

  8. Augmented reality for Android application development

    CERN Document Server

    Grubert, Jens

    2013-01-01

    A step-by-step tutorial-based guide aimed at giving you hands-on practical experience to develop AR applications for Android.Augmented Reality for Android Application Development is for Android mobile application developers who are familiar with Android Development Tools and deployment, JMonkeyEngine, and the Vuforia SDK.

  9. Augmenting the ADDIE Paradigm for Instructional Design

    Science.gov (United States)

    Ni, Xiaopeng; Branch, Robert Maribe

    2008-01-01

    The authors discuss topics appropriate for augmenting the ADDIE paradigm for instructional design. The topics selected are based on data from a study of working professionals who successfully completed an instructional design and technology certificate program and who identified related topics that they regarded as beneficial. The participants…

  10. E-Learning: Between Augmentation and Disruption?

    Science.gov (United States)

    Heilesen, Simon B.; Josephsen, Jens

    2008-01-01

    Based on a framework for analysis combining diffusion theory, content layer analysis and sense making, this paper discusses the theme of "e-learning as augmentation or disruption" from the point of view of technological innovation. Two cases of on-campus blended learning at Roskilde University, Denmark, are introduced to illustrate the…

  11. Global Navigation Satellite System and Augmentation

    Indian Academy of Sciences (India)

    Global Navigation Satellite System and Augmentation. K C T Swamy. Dr. K C T Swamy is an. Associate Professor in ECE at. G Pullaih College of. Engineering and Technology,. Kurnool, Andhra Pradesh. His research interests are global navigation satellite system and antennas. He has been carrying out research in.

  12. Sensitive and specific detection of the non-human sialic Acid N-glycolylneuraminic acid in human tissues and biotherapeutic products.

    Directory of Open Access Journals (Sweden)

    Sandra L Diaz

    Full Text Available BACKGROUND: Humans are genetically defective in synthesizing the common mammalian sialic acid N-glycolylneuraminic acid (Neu5Gc, but can metabolically incorporate it from dietary sources (particularly red meat and milk into glycoproteins and glycolipids of human tumors, fetuses and some normal tissues. Metabolic incorporation of Neu5Gc from animal-derived cells and medium components also results in variable contamination of molecules and cells intended for human therapies. These Neu5Gc-incorporation phenomena are practically significant, because normal humans can have high levels of circulating anti-Neu5Gc antibodies. Thus, there is need for the sensitive and specific detection of Neu5Gc in human tissues and biotherapeutic products. Unlike monoclonal antibodies that recognize Neu5Gc only in the context of underlying structures, chicken immunoglobulin Y (IgY polyclonal antibodies can recognize Neu5Gc in broader contexts. However, prior preparations of such antibodies (including our own suffered from some non-specificity, as well as some cross-reactivity with the human sialic acid N-acetylneuraminic acid (Neu5Ac. METHODOLOGY/PRINCIPAL FINDINGS: We have developed a novel affinity method utilizing sequential columns of immobilized human and chimpanzee serum sialoglycoproteins, followed by specific elution from the latter column by free Neu5Gc. The resulting mono-specific antibody shows no staining in tissues or cells from mice with a human-like defect in Neu5Gc production. It allows sensitive and specific detection of Neu5Gc in all underlying glycan structural contexts studied, and is applicable to immunohistochemical, enzyme-linked immunosorbent assay (ELISA, Western blot and flow cytometry analyses. Non-immune chicken IgY is used as a reliable negative control. We show that these approaches allow sensitive detection of Neu5Gc in human tissue samples and in some biotherapeutic products, and finally show an example of how Neu5Gc might be eliminated

  13. The CMP-sialic acid transporter is localized in the medial-trans Golgi and possesses two specific endoplasmic reticulum export motifs in its carboxyl-terminal cytoplasmic tail.

    Science.gov (United States)

    Zhao, Weihan; Chen, Tung-Ling L; Vertel, Barbara M; Colley, Karen J

    2006-10-13

    The addition of sialic acid to glycoproteins and glycolipids requires Golgi sialyltransferases to have access to their glycoconjugate substrates and nucleotide sugar donor, CMP-sialic acid. CMP-sialic acid is transported into the lumen of the Golgi complex through the CMP-sialic acid transporter, an antiporter that also functions to transport CMP into the cytosol. We localized the transporter using immunofluorescence and deconvolution microscopy to test the prediction that it is broadly distributed across the Golgi stack to serve the many sialyltransferases involved in glycoconjugate sialylation. The transporter co-localized with ST6GalI in the medial and trans Golgi, showed partial overlap with a medial Golgi marker and little overlap with early Golgi or trans Golgi network markers. Endoplasmic reticulum-retained forms of sialyltransferases did not redistribute the transporter from the Golgi to the endoplasmic reticulum, suggesting that transporter-sialyltransferase complexes are not involved in transporter localization. Next we evaluated the role of the transporter's N- and C-terminal cytoplasmic tails in its trafficking and localization. The N-tail was not required for either endoplasmic reticulum export or Golgi localization. The C-tail was required for endoplasmic reticulum export and contained di-Ile and terminal Val motifs at its very C terminus that function as independent endoplasmic reticulum export signals. Deletion of the last four amino acids of the C-tail (IIGV) eliminated these export signals and prevented endoplasmic reticulum export of the transporter. This form of the transporter supplied limited amounts of CMP-sialic acid to Golgi sialyltransferases but was unable to completely rescue the transporter defect of Lec2 Chinese hamster ovary cells.

  14. Motion in Augmented Reality Games: An Engine for Creating Plausible Physical Interactions in Augmented Reality Games

    OpenAIRE

    Brian Mac Namee; David Beaney; Qingqing Dong

    2010-01-01

    The next generation of Augmented Reality (AR) games will require real and virtual objects to coexist in motion in immersive game environments. This will require the illusion that real and virtual objects interact physically together in a plausible way. The Motion in Augmented Reality Games (MARG) engine described in this paper has been developed to allow these kinds of game environments. The paper describes the design and implementation of the MARG engine and presents two proof-of-concept AR ...

  15. The role of imaging in pediatric bladder augmentation

    Energy Technology Data Exchange (ETDEWEB)

    Breen, Micheal; Chow, Jeanne S. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Phelps, Andrew [UCSF Benioff Children' s Hospital San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Estrada, Carlos [Boston Children' s Hospital, Department of Urology, Boston, MA (United States)

    2015-09-15

    Bladder augmentation (also called augmentation cystoplasty) refers to a number of surgical methods that increase the capacity and compliance of the urinary bladder. Imaging has an important role in the postoperative evaluation of bladder augmentation. The most common augmentation procedures utilize enteric segments to augment the bladder. The various types of bladder augmentation have characteristic appearances on different imaging modalities. Spontaneous bladder perforation is a complication that is seen in both early and late post-operative periods and it is one of the most important complications for radiologists to be aware of as it is life-threatening. We review the indications for bladder augmentation in children, the surgical techniques employed, the normal postoperative appearances on imaging studies and the role of imaging complications of bladder augmentation including delayed spontaneous bladder rupture, which is life-threatening. (orig.)

  16. Adeno-Associated Virus Type 12 (AAV12): a Novel AAV Serotype with Sialic Acid- and Heparan Sulfate Proteoglycan-Independent Transduction Activity▿

    Science.gov (United States)

    Schmidt, Michael; Voutetakis, Antonis; Afione, Sandra; Zheng, Changyu; Mandikian, Danielle; Chiorini, John A.

    2008-01-01

    Recombinant adeno-associated virus (rAAV) is a promising vector for gene therapy. Recent isolations of novel AAV serotypes have led to significant advances by broadening the tropism and increasing the efficiency of gene transfer to the desired target cell. However, a major concern that remains is the strong preexisting immune responses to several vectors. In this paper, we describe the isolation and characterization of AAV12, an AAV serotype with unique biological and immunological properties. In contrast to those of all other reported AAVs, AAV12 cell attachment and transduction do not require cell surface sialic acids or heparan sulfate proteoglycans. Furthermore, rAAV12 is resistant to neutralization by circulating antibodies from human serum. The feasibility of rAAV12 as a vector was demonstrated in a mouse model in which muscle and salivary glands were transduced. These characteristics make rAAV12 an interesting candidate for gene transfer applications. PMID:18045941

  17. Projector augmented wave method: ab initio molecular dynamics ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. A brief introduction to the projector augmented wave method is given and recent developments are reviewed. The projector augmented wave method is an all-electron method for efficient ab initio molecular dynamics simulations with full wave functions. It extends and combines the traditions of existing augmented.

  18. Initial Model of Social Acceptability for Human Augmentation Technologies

    NARCIS (Netherlands)

    Eghtebas, Chloe; Pay, Yun Suen; Väänänen, Kaisa; Pfeiffer, Ties; Meyer, Joachim; Lukosch, S.G.

    2017-01-01

    Academia and industry engage in major efforts to develop technologies for augmenting human senses and activities. Many of these technologies, such as augmented reality (AR) and virtual reality (VR) head mounted displays (HMD), haptic augmentation systems, and exoskeletons can be applied in numerous

  19. Current concepts on complications associated with sinus augmentation procedures

    NARCIS (Netherlands)

    Boffano, P.; Forouzanfar, T.

    2014-01-01

    The sinus augmentation, or sinus lift procedure, is an internal augmentation of the maxillary sinus, which is intended to increase the vertical bony dimension in the lateral maxilla to make the placement of dental implants possible. Complication rate associated with maxillary sinus augmentation

  20. Current Concepts on Complications Associated With Sinus Augmentation Procedures

    NARCIS (Netherlands)

    Boffano, P.; Forouzanfar, T.

    2014-01-01

    The sinus augmentation, or sinus lift procedure, is an internal augmentation of the maxillary sinus, which is intended to increase the vertical bony dimension in the lateral maxilla to make the placement of dental implants possible. Complication rate associated with maxillary sinus augmentation

  1. Engineering the fragment crystallizable (Fc) region of human IgG1 multimers and monomers to fine-tune interactions with sialic acid-dependent receptors.

    Science.gov (United States)

    Blundell, Patricia A; Le, Ngoc Phuong Lan; Allen, Joel; Watanabe, Yasunori; Pleass, Richard J

    2017-08-04

    Multimeric fragment crystallizable (Fc) regions and Fc-fusion proteins are actively being explored as biomimetic replacements for IVIG therapy, which is deployed to manage many diseases and conditions but is expensive and not always efficient. The Fc region of human IgG1 (IgG1-Fc) can be engineered into multimeric structures (hexa-Fcs) that bind their cognate receptors with high avidity. The critical influence of the unique N-linked glycan attached at Asn-297 on the structure and function of IgG1-Fc is well documented; however, whether the N-linked glycan has a similarly critical role in multimeric, avidly binding Fcs, is unknown. Hexa-Fc contains two N-linked sites at Asn-77 (equivalent to Asn-297 in the Fc of IgG1) and Asn-236 (equivalent to Asn-563 in the tail piece of IgM). We report here that glycosylation at Asn-297 is critical for interactions with Fc receptors and complement and that glycosylation at Asn-563 is essential for controlling multimerization. We also found that introduction of an additional fully occupied N-linked glycosylation site at the N terminus at position 1 (equivalent to Asp-221 in the Fc of IgG1) dramatically enhances overall sialic acid content of the Fc multimers. Furthermore, replacement of Cys-575 in the IgM tail piece of multimers resulted in monomers with enhanced sialic acid content and differential receptor-binding profiles. Thus insertion of additional N-linked glycans into either the hinge or tail piece of monomers or multimers leads to molecules with enhanced sialylation that may be suitable for managing inflammation or blocking pathogen invasion. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Detection of Glycomic Alterations Induced by Overexpression of P-Glycoprotein on the Surfaces of L1210 Cells Using Sialic Acid Binding Lectins

    Directory of Open Access Journals (Sweden)

    Albert Breier

    2012-11-01

    Full Text Available P-glycoprotein (P-gp overexpression is the most frequently observed cause of multidrug resistance in neoplastic cells. In our experiments, P-gp was expressed in L1210 mice leukemia cells (S cells by selection with vincristine (R cells or transfection with the gene encoding human P-gp (T cells. Remodeling of cell surface sugars is associated with P-gp expression in L1210 cells as a secondary cellular response. In this study, we monitored the alteration of cell surface saccharides by Sambucus nigra agglutinin (SNA, wheat germ agglutinin (WGA and Maackia amurensis agglutinin (MAA. Sialic acid is predominantly linked to the surface of S, R and T cells via α-2,6 branched sugars that tightly bind SNA. The presence of sialic acid linked to the cell surface via α-2,3 branched sugars was negligible, and the binding of MAA (recognizing this branch was much less pronounced than SNA. WGA induced greater cell death than SNA, which was bound to the cell surface and agglutinated all three L1210 cell-variants more effectively than WGA. Thus, the ability of lectins to induce cell death did not correlate with their binding efficiency and agglutination potency. Compared to S cells, P-gp positive R and T cells contain a higher amount of N-acetyl-glucosamine on their cell surface, which is associated with improved WGA binding. Both P-gp positive variants of L1210 cells are strongly resistant to vincristine as P-gp prototypical drug. This resistance could not be altered by liberalization of terminal sialyl residues from the cell surface by sialidase.

  3. Engineering of the glycan-binding specificity of Agrocybe cylindracea galectin towards α(2,3)-linked sialic acid by saturation mutagenesis.

    Science.gov (United States)

    Imamura, Koji; Takeuchi, Hideaki; Yabe, Rikio; Tateno, Hiroaki; Hirabayashi, Jun

    2011-11-01

    Sialic acid represents a critical sugar component located at the outermost position of glycoconjugates, playing important roles in extensive biological processes. To date, however, there have been only few probes which show affinity to α(2,3)-linked sialic acid-containing glycoconjugates. Agrocybe cylindracea galectin is known to have a relatively high affinity towards Neu5Acα(2,3)Galβ(1,4)Glc (3'-sialyl lactose), but it significantly recognizes various β-galactosides, such as Galβ(1,4)GlcNAcβ (LacNAc) and Galβ(1,3)GalNAcα (T-antigen). To eliminate this background specificity, we focused an acidic amino acid residue (Glu86), which interacts with the glucose unit of 3'-sialyl lactose and substituted it with all other amino acids. Carbohydrate-binding specificity of the derived 14 mutants was analysed by surface plasmon resonance, and it was found that E86D mutant (Glu86 substituted with Asp) substantially lost the binding ability to LacNAc and T-antigen, while it retained the high affinity for 3'-sialyl lactose. Further, frontal affinity chromatography analysis using 132 pyridylaminated oligosaccharides confirmed that the E86D mutant had a strong preference for α(2,3)-disialo biantennary N-linked glycan. However, it showed the large decrease in the affinity for any of the asialo complex-type N-glycans and the glycolipid-type glycans. Thus, the developed mutant E86D will be of practical use in various fields relevant to cell biology and glycotechnology.

  4. Perancangan Augmented Reality untuk Peta Topografi

    Directory of Open Access Journals (Sweden)

    Agustinna Yosanny

    2013-12-01

    Full Text Available Topography is the science about the earth's surface and other objects such as planets, satellites, and asteroids. Topography is studied at school and is found quite difficult to understand because it requires imagination to understand the meaning of contour maps as well as the lines. To motivate students in learning topography,we design an learning application of interactive topographic map with 3D features using Augmented reality technology. In this research we implement analysis and design method. The result achieved is a learning topographic map application based on augmented reality. The conclusion that can be drawn is the teaching and learning of topography can be more interesting with 3D features so that students can more easily recognize the meaning of contour lines in a topographic map.

  5. Camera Based Navigation System with Augmented Reality

    Directory of Open Access Journals (Sweden)

    M. Marcu

    2012-06-01

    Full Text Available Nowadays smart mobile devices have enough processing power, memory, storage and always connected wireless communication bandwidth that makes them available for any type of application. Augmented reality (AR proposes a new type of applications that tries to enhance the real world by superimposing or combining virtual objects or computer generated information with it. In this paper we present a camera based navigation system with augmented reality integration. The proposed system aims to the following: the user points the camera of the smartphone towards a point of interest, like a building or any other place, and the application searches for relevant information about that specific place and superimposes the data over the video feed on the display. When the user moves the camera away, changing its orientation, the data changes as well, in real-time, with the proper information about the place that is now in the camera view.

  6. Interactive learning environments in augmented reality technology

    Directory of Open Access Journals (Sweden)

    Rafał Wojciechowski

    2010-01-01

    Full Text Available In this paper, the problem of creation of learning environments based on augmented reality (AR is considered. The concept of AR is presented as a tool for safe and cheap experimental learning. In AR learning environments students may acquire knowledge by personally carrying out experiments on virtual objects by manipulating real objects located in real environments. In the paper, a new approach to creation of interactive educational scenarios, called Augmented Reality Interactive Scenario Modeling (ARISM, is mentioned. In this approach, the process of building learning environments is divided into three stages, each of them performed by users with different technical and domain knowledge. The ARISM approach enables teachers who are not computer science experts to create AR learning environments adapted to the needs of their students.

  7. The effects of augmented reality on learning.

    Science.gov (United States)

    Hsiao, Kuei-Fang

    2010-01-01

    In this study, a new approach to the implementation of Augmented Reality (AR) in the educational environment was taken by creating a Chemistry Augmented Reality Learning System (CARLS), using the existing teaching curriculum, together with physical activity. This system combined learning with three types of physical activity: aerobic fitness, muscle strength and flexibility fitness. This study reveals that the students using all three types of physical activity together with CARLS result in significantly higher academic performance compared to the traditional Keyboard-Mouse CAI (KMCAI). This improvement is most evident for the non-memorized knowledge component of Science. Moreover, the students in the AR group with 'muscle strength' physical activity had significantly more positive learning attitude change toward Science than those in the KMCAI group. A great additional benefit of our approach is that, students also obtained more physical fitness while learning.

  8. Viscoelastic-augmented trabeculectomy: A newer concept

    Directory of Open Access Journals (Sweden)

    Meghna Solanki

    2017-01-01

    Full Text Available Purpose: Comparison of conventional trabeculectomy (CT and viscoelastic-augmented trabeculectomy (VAT in primary open-angle glaucoma. Methods: A total of 65 primary open-angle glaucoma cases were taken for each of the two groups, i.e., CT and VAT. Viscoelastic-augmented trabeculectomy constituted lamellar scleral flap, deep scleral flap, penetrating trabeculectomy, peripheral iridectomy, filling of the anterior chamber with viscoelastic (sodium hyaluronate and balanced salt solution, movement of visco in bleb, and tight flap closure. Success criteria included intraocular pressure (IOP <14 mmHg with no devastating complications. P < 0.05 was considered statistically significant. Results: Mean IOP was significantly lower after VAT compared to CT at 6 weeks, 12 weeks, and 6 months postoperatively. Target IOP was achieved in 60% cases in VAT group compared to 36.92% in CT group. Conclusion: VAT is effective in reducing IOP to the target level for advanced glaucoma with lower postoperative complications.

  9. Survey on Urban Warfare Augmented Reality

    Directory of Open Access Journals (Sweden)

    Xiong You

    2018-01-01

    Full Text Available Urban warfare has become one of the main forms of modern combat in the twenty-first century. The main reason why urban warfare results in hundreds of casualties is that the situational information of the combatant is insufficient. Accessing information via an Augmented Reality system can elevate combatants’ situational awareness to effectively improve the efficiency of decision-making and reduce the injuries. This paper begins with the concept of Urban Warfare Augmented Reality (UWAR and illuminates the objectives of developing UWAR, i.e., transparent battlefield, intuitional perception and natural interaction. Real-time outdoor registration, information presentation and natural interaction are presented as key technologies of a practical UWAR system. Then, the history and current research state of these technologies are summarized and their future developments are highlighted from three perspectives, i.e., (1 Better integration with Geographic Information System and Virtual Geographic Environment; (2 More intelligent software; (3 More powerful hardware.

  10. Augmented Interactive Scores for Music Creation

    OpenAIRE

    Fober, Dominique; Orlarey, Yann; Letz, Stéphane

    2014-01-01

    International audience; This article addresses music representation issues in the context of the contemporary music creation and performance. It exposes the main challenges in terms of music notation and representation, in regard of the new forms of music and with an emphasis on interactive music issues. It presents INScore, an environment for the design of augmented, interactive music scores that has been developed in response to current artistic evolutions. It gives an overview of the syste...

  11. (Re-)Examination of Multimodal Augmented Reality

    OpenAIRE

    Rosa, N.E.; Werkhoven, P.J.; Hürst, W.O.

    2016-01-01

    The majority of augmented reality (AR) research has been concerned with visual perception, however the move towards multimodality is imminent. At the same time, there is no clear vision of what multimodal AR is. The purpose of this position paper is to consider possible ways of examining AR other than using popular notions and definitions, in order to come to an understanding of multimodal AR. Three concepts are introduced. First, the commonly used terms 'real' and 'virtual' are redefined in ...

  12. CIRSE Guidelines on Percutaneous Vertebral Augmentation

    Energy Technology Data Exchange (ETDEWEB)

    Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Too, Chow Wei, E-mail: spyder55@gmail.com; Koch, Guillaume, E-mail: guillaume.koch@gmail.com; Caudrelier, Jean, E-mail: jean.caudrelier@chru-strasbourg.fr; Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Garnon, Julien, E-mail: juliengarnon@gmail.com; Gangi, Afshin, E-mail: gangi@unistra.fr [Strasbourg University Hospital, Interventional Radiology Department (France)

    2017-03-15

    Vertebral compression fracture (VCF) is an important cause of severe debilitating back pain, adversely affecting quality of life, physical function, psychosocial performance, mental health and survival. Different vertebral augmentation procedures (VAPs) are used in order to consolidate the VCFs, relief pain,and whenever posible achieve vertebral body height restoration. In the present review we give the indications, contraindications, safety profile and outcomes of the existing percutaneous VAPs.

  13. Augmented REality Sandtables (ARESs) Impact on Learning

    Science.gov (United States)

    2016-07-01

    knowledge and spatial-reasoning skills over traditional maps (e.g., paper map and digitized 2-D displays) by providing multimodal and multisensory learning...SUBJECT TERMS ARES, augmented reality, sand table, map reading , terrain, visualization, topography 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...2.6 Procedure 5 3. Results and Discussion 6 3.1 Data Reduction and Analysis 6 3.1.1 Outlier Analysis 8 3.1.2 Normality Testing 8 3.1.3 Sphericity

  14. Multiple Kernel Learning with Data Augmentation

    Science.gov (United States)

    2016-11-22

    Intelligence and Artificial Neural Networks Symposium (TAINN 96. Citeseer, 1996. Erling D Andersen and Knud D Andersen. The mosek interior point optimizer...Zien, and Sören Sonnen- burg. Efficient and accurate lp-norm multiple kernel learning . In Advances in neural information processing systems, pages 997...JMLR: Workshop and Conference Proceedings 63:49–64, 2016 ACML 2016 Multiple Kernel Learning with Data Augmentation Khanh Nguyen nkhanh@deakin.edu.au

  15. Augmentation Mammaplasty Using Implants: A Review

    Directory of Open Access Journals (Sweden)

    Susumu Takayanagi

    2012-09-01

    Full Text Available One of the techniques for augmentation mammaplasty is the procedure using implants. Eventhough this technique has been used for many years, there are still several controversial issuesto be discussed and overcome for patient safety. In this review article, capsular contracture,leak or rupture of the implants, possible systemic disease, relation with breast cancer, andrecent problems with Poly Implant Prothese implants are described and discussed.

  16. nARratives of augmented worlds

    OpenAIRE

    Shilkrot, Roy; Montfort, Nick; Maes, Patricia

    2014-01-01

    This paper presents an examination of augmented reality (AR) as a rising form of interactive narrative that combines computer-generated elements with reality, fictional with non-fictional objects, in the same immersive experience. Based on contemporary theory in narratology, we propose to view this blending of reality worlds as a metalepsis, a transgression of reality and fiction boundaries, and argue that authors could benefit from using existing conventions of narration to emphasize the tra...

  17. Augmented reality visualization for thoracoscopic spine surgery

    Science.gov (United States)

    Sauer, Frank; Vogt, Sebastian; Khamene, Ali; Heining, Sandro; Euler, Ekkehard; Schneberger, Marc; Zuerl, Konrad; Mutschler, Wolf

    2006-03-01

    We are developing an augmented reality (AR) image guidance system in which information derived from medical images is overlaid onto a video view of the patient. The centerpiece of the system is a head-mounted display custom fitted with two miniature color video cameras that capture the stereo view of the scene. Medical graphics is overlaid onto the video view and appears firmly anchored in the scene, without perceivable time lag or jitter. We have been testing the system for different clinical applications. In this paper we discuss minimally invasive thoracoscopic spine surgery as a promising new orthopedic application. In the standard approach, the thoracoscope - a rigid endoscope - provides visual feedback for the minimally invasive procedure of removing a damaged disc and fusing the two neighboring vertebrae. The navigation challenges are twofold. From a global perspective, the correct vertebrae on the spine have to be located with the inserted instruments. From a local perspective, the actual spine procedure has to be performed precisely. Visual feedback from the thoracoscope provides only limited support for both of these tasks. In the augmented reality approach, we give the surgeon additional anatomical context for the navigation. Before the surgery, we derive a model of the patient's anatomy from a CT scan, and during surgery we track the location of the surgical instruments in relation to patient and model. With this information, we can help the surgeon in both the global and local navigation, providing a global map and 3D information beyond the local 2D view of the thoracoscope. Augmented reality visualization is a particularly intuitive method of displaying this information to the surgeon. To adapt our augmented reality system to this application, we had to add an external optical tracking system, which works now in combination with our head-mounted tracking camera. The surgeon's feedback to the initial phantom experiments is very positive.

  18. Augmented Reality to Training Spatial Skills

    OpenAIRE

    Martín-Gutiérrez, Jorge; Contero, Manuel; Alcañiz, Mariano

    2015-01-01

    La Laguna University has been offering courses for the development of spatial skills since 2004. Each year since that time spatial ability of engineering students has been measured before and after the courses to check progress after each training session. We have developed a spatial skills training course based on augmented reality and graphic engineering contents, and designed the AR_Dehaes tool, which is based on its own library the uses computer vision techniques for incorporating vis...

  19. Index matrices towards an augmented matrix calculus

    CERN Document Server

    Atanassov, Krassimir T

    2014-01-01

    This book presents the very concept of an index matrix and its related augmented matrix calculus in a comprehensive form. It mostly illustrates the exposition with examples related to the generalized nets and intuitionistic fuzzy sets which are examples of an extremely wide array of possible application areas. The present book contains the basic results of the author over index matrices and some of its open problems with the aim to stimulating more researchers to start working in this area.

  20. Augmented reality for non-rigid surfaces

    OpenAIRE

    Pilet, Julien

    2008-01-01

    Augmented Reality (AR) is the process of integrating virtual elements in reality, often by mixing computer graphics into a live video stream of a real scene. It requires registration of the target object with respect to the cameras. To this end, some approaches rely on dedicated hardware, such as magnetic trackers or infra-red cameras, but they are too expensive and cumbersome to reach a large public. Others are based on specifically designed markers which usually look like bar-codes. However...

  1. Comparative efficacy and acceptability of seven augmentation ...

    African Journals Online (AJOL)

    The results revealed that T3 was more efficacious than lithium, TCAs, AAPs, AEDs, buspirone and CBT with odds ratios (ORs) of 1.58, 1.56, 1.51, 1.47, 1.77 and 1.25, respectively. ORs favoured CBT compared with lithium, TCAs, AAPs, AEDs and buspirone. Buspirone was the least efficacious of all the other augmentation ...

  2. Conical polyurethane implants: an uplifting augmentation.

    Science.gov (United States)

    Georgeu, Garrick A; Frame, James D; Frame, James D

    2013-11-01

    Polyurethane-coated conical implants were introduced by Silimed (US distributor: Sientra, Santa Barbara, California) in 2008 and offer an alternative to round or anatomically shaped implants. By their design and volume distribution, they naturally create central volume and give a reasonable fullness to the upper pole while lifting some ptotic breasts, thus avoiding the need for classical mastopexy. The authors discuss the advantages of conical implants as an alternative to conventional silicone implants for women with breast ptosis. In the 2-year period between December 2010 and December 2012, a consecutive series of 302 women underwent implant-based breast surgery procedures (236 primary augmentations, 59 revisions, and 7 mastopexy-augmentations) with conical polyurethane devices. Implant volumes ranged from 225 to 560 cc, with low- to medium-profile devices predominating. No extra-high-profile implants were used. Only 1 patient had a drain inserted on completion of a revision augmentation. There were no infections (0%) and no wound dehiscence (0%). Four cases required reoperation (1.3%). Patient satisfaction scores were universally high (average, 9.94/10). There have been no capsular contractures to date, but follow-up is short. The modern conical, polyurethane implant has many advantages over the conventional round or anatomically shaped implants and offers patients an ideal compromise between volume, natural upper pole fullness, and a lift without mastopexy scars.

  3. Labor Augmentation with Oxytocin Decreases Glutathione Level

    Directory of Open Access Journals (Sweden)

    Naomi Schneid-Kofman

    2009-01-01

    Full Text Available Objective. To compare oxidative stress following spontaneous vaginal delivery with that induced by Oxytocin augmented delivery. Methods. 98 women recruited prior to labor. 57 delivered spontaneously, while 41 received Oxytocin for augmentation of labor. Complicated deliveries and high-risk pregnancies were excluded. Informed consent was documented. Arterial cord blood gases, levels of Hematocrit, Hemoglobin, and Bilirubin were studied. Glutathione (GSH concentration was measured by a spectroscopic method. Plasma and red blood cell (RBC levels of Malondialdehyde indicated lipid peroxidation. RBC uptake of phenol red denoted cell penetrability. SPSS data analysis was used. Results. Cord blood GSH was significantly lower in the Oxytocin group (2.3±0.55 mM versus 2.55±0.55 mM, =.01. No differences were found in plasma or RBC levels of MDA or in uptake of Phenol red between the groups. Conclusion. Lower GSH levels following Oxytocin augmentation indicate an oxidative stress, though selected measures of oxidative stress demonstrate no cell damage.

  4. Augmented spaces, a look beyond advertising

    Directory of Open Access Journals (Sweden)

    Oana Andreea Căplescu

    2014-03-01

    Full Text Available From billboards to urban screens and now to media facades, the augmentation of our cities has expanded, changing social behaviours and public space consumption. Smart buildings are being developed and, much like the smartphones, these hybrids are not only in sci-fi movies anymore. One of the main promoters of media facades and media architecture has been the advertising industry. But artists and designers showed the potential of different approaches, experimenting with digitally augmented spaces both indoors and outdoors. Going beyond the commercial aspect of being an advertising and branding tool, these hybrids offer a variety of uses. Questions of how and where we use them and how they can improve our life quality are discussed here emphasizing that we developed a media behaviour, adjusting our relation to the physical and information environments. I examine some of the most notable experiments outside of the advertising sphere, offering a base for future development of augmented spaces and opening the discussion over the language of new media architecture.

  5. A Mobile Augmented Reality Emulator for Android

    Directory of Open Access Journals (Sweden)

    Donald Munro

    2017-07-01

    Full Text Available Augmented Reality (AR provides a fusion of the real and virtual worlds by superimposing virtual objects on real world scenery. The implementation of AR on mobile devices is known as Mobile Augmented Reality (MAR. MAR is in its infancy and MAR development software is in the process of maturing. Dating back to the origin of Computer Science as an independent field, software development tools have been an integral part of the process of software creation. MAR, being a relatively new technology, is still lacking such related software development tools. With the rapid progression of mobile devices, the development of MAR applications fusing advanced Computer Vision techniques with mobile device sensors have become increasingly feasible. However, testing and debugging of MAR applications present a new challenge in that they require the developer be at the location that is being augmented at some point during the development process. In this research study, a MAR recorder application was developed as well as emulation class libraries for Android devices that allows the recording and off-site playback of video, location and motion sensor data. The research objective was to provide a software emulator which provides debugging, testing and prototyping capabilities for a MAR application including the ability to emulate the combination of computer vision with locational and motion sensors using previously recorded data. The emulator was evaluated using different mobile technologies. The results indicate that this research could assist developers of MAR applications to implement applications more rapidly, without being at the location.

  6. Adaptive information design for outdoor augmented reality.

    Science.gov (United States)

    Neuhöfer, Jan A; Govaers, Felix; El Mokni, Hichem; Alexander, Thomas

    2012-01-01

    Augmented Reality focuses on the enrichment of the user's natural field of view by consistent integration of text, symbols and interactive three-dimensional objects in real time. Placing virtual objects directly into the user's view in a natural context empowers highly dynamic applications. On the other hand, this necessitates deliberate choice of information design and density, in particular for deployment in hazardous environments like military combat scenarios. As the amount of information needed is not foreseeable and strongly depends on the individual mission, an appropriate system must offer adequate adaptation capabilities. The paper presents a prototypical, vehicle-mountable Augmented Reality vision system, designed for enhancing situation awareness in stressful urban warfare scenarios. Tracking, as one of the most crucial challenges for outdoor Augmented Reality, is accomplished by means of a Differential-GPS approach while the type of display to attach can be modified, ranging from ocular displays to standard LCD mini-screens. The overall concept also includes envisioning of own troops (blue forces), for which a multi-sensor tracking approach has been chosen. As a main feature, the system allows switching between different information categories, focusing on friendly, hostile, unidentified or neutral data. Results of an empirical study on the superiority of an in-view navigation cue approach conclude the paper.

  7. Girth augmentation of the penis using flaps "Shaeer's augmentation phalloplasty": the superficial circumflex iliac flap.

    Science.gov (United States)

    Shaeer, Osama

    2014-07-01

    Penile girth augmentation can be achieved by various techniques, among which are liposuction injection, synthetic grafts, and autologous grafts, with variable outcome, mostly related to viability and receptivity of the tissue used for augmentation. Flaps are considered superior to grafts considering their uninterrupted blood supply. The current work describes long-term experience with penile girth augmentation using the superficial circumflex iliac artery and vein (SCIAV) flap. SCIAV flap was used for penile girth augmentation in 40 candidates who followed up for a minimum of 18 months. The flap was mobilized from the groin region. The penis was pulled out of a peno-pubic incision. The flap was tunneled under the pubic region to emerge at the base of the penis and was sutured to the subcoronal area and on either sides of the spongiosum. Another session was required for either de-bulking of the oversized flap (four overweight candidates), flap pedicle (n = 6), or for donor site scar revision (n = 11). Gain in girth in centimeters was evaluated. Excluding dropouts (n = 8) and participants who had encountered de-bulking of the flap body (n = 4), 40 participants had a preoperative average flaccid girth (AFG) of 9.3 ± 1.1 cm. Immediately postoperative AFG was 14.9 ± 1.1 cm (P < 0.001). Postoperative AFG at the final follow-up visit (a minimum of 18 months) was 14.5 ± 1.1 cm (55.6% gain compared with baseline, P < 0.001). SCIAV flap is a reliable option for long-lasting and sizable penile girth augmentation. One-stage augmentation is more suited for non-obese candidates. A second session may be indicated in overweight candidates or for scar revision. © 2014 International Society for Sexual Medicine.

  8. Repeated vertebral augmentation for new vertebral compression fractures of postvertebral augmentation patients: a nationwide cohort study

    Directory of Open Access Journals (Sweden)

    Liang CL

    2015-03-01

    Full Text Available Cheng-Loong Liang,1 Hao-Kwan Wang,1 Fei-Kai Syu,2 Kuo-Wei Wang,1 Kang Lu,1 Po-Chou Liliang1 1Department of Neurosurgery, E-Da Hospital, I-Shou University, Kaohsiung City, Taiwan; 2Department of Pharmacy, China Medical University Hospital, Taichung City, Taiwan Purpose: Postvertebral augmentation vertebral compression fractures are common; repeated vertebral augmentation is usually performed for prompt pain relief. This study aimed to evaluate the incidence and risk factors of repeat vertebral augmentation.Methods: We performed a retrospective, nationwide, population-based longitudinal observation study, using the National Health Insurance Research Database (NHIRD of Taiwan. All patients who received vertebral augmentation for vertebral compression fractures were evaluated. The collected data included patient characteristics (demographics, comorbidities, and medication exposure and repeat vertebral augmentation. Kaplan–Meier and stratified Cox proportional hazard regressions were performed for analyses.Results: The overall incidence of repeat vertebral augmentation was 11.3% during the follow-up until 2010. Patients with the following characteristics were at greater risk for repeat vertebral augmentation: female sex (AOR=1.24; 95% confidence interval [CI]: 1.10–2.36, advanced age (AOR=1.60; 95% CI: 1.32–2.08, diabetes mellitus (AOR=4.31; 95% CI: 4.05–5.88, cerebrovascular disease (AOR=4.09; 95% CI: 3.44–5.76, dementia (AOR=1.97; 95% CI: 1.69–2.33, blindness or low vision (AOR=3.72; 95% CI: 2.32–3.95, hypertension (AOR=2.58; 95% CI: 2.35–3.47, and hyperlipidemia (AOR=2.09; 95% CI: 1.67–2.22. Patients taking calcium/ vitamin D (AOR=2.98; 95% CI: 1.83–3.93, bisphosphonates (AOR=2.11; 95% CI: 1.26–2.61, or calcitonin (AOR=4.59; 95% CI: 3.40–5.77 were less likely to undergo repeat vertebral augmentation; however, those taking steroids (AOR=7.28; 95% CI: 6.32–8.08, acetaminophen (AOR=3.54; 95% CI: 2.75–4.83, or nonsteroidal

  9. Complications of Fat Transfer for Breast Augmentation.

    Science.gov (United States)

    Kontoes, Paraskevas; Gounnaris, George

    2017-10-01

    Autologous fat grafting is quite common for breast augmentations as well as for reconstructive breast surgery. Coleman has described the surgical technique of fat grafting. Fat is harvested, and after centrifugation and refinement, blunt infiltration cannulas are used to place the fat through small incisions. The grafted tissue is placed in small aliquots with each withdrawal of the cannula. In order to achieve an aesthetically pleasing contour of the breast, the fat should be layered into different levels from the chest wall to the skin. However, autogenous lipotransfer if not performed lege artis might lead to complications such as fat necrosis, calcification, formation of encapsulated fatty masses (cystic lesions), lymphadenopathy, disfigurement of breast contouring, hypersensitive breasts, itchy nipples. A 36-year old female patient, presented with multiple palpable cystic lesions, disrupted breast contouring, asymmetry, hypersensation and pain during examination, 6 months after autologous fat grafting for breast augmentation elsewhere. The patient had ultrasound and MRI screening, which revealed the multiple bilateral cysts formation in the breast tissue. Surgical removal of the large lesions was performed, and specimens were sent for pathology and cytology consideration and screening. A few months after surgical removal of these lesions and after symptoms subsided, breast augmentation was performed with silicone implants. An aesthetically pleasing result together with relief of the patient's initial symptomatology was achieved. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  10. SPRINT spray intercooling augments LM6000 output

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David

    1998-09-01

    By injecting water between the low pressure and high pressure compressors of an aeroderivative gas turbine, GE-IAD engineers have demonstrated that a 9 per cent increase in output accompanied by reduced life cycle costs can be achieved. Designated the SPRINT system, uprated LM 6000 units with augmented efficiency have been introduced to the market. The first two production units, both supplied to Southern Electric Power Generation in England for mid-merit independent power generation plants at Chickerell in Dorset and Burghfield in Berkshire, have each clocked in excess of 500 operating hours since start-up in early April 1998. MPS visited the Chickerell installation in late July 1998. (UK)

  11. Augmented reality for breast tumors visualization.

    Science.gov (United States)

    Ghaderi, Mohammad Ali; Heydarzadeh, Mehrdad; Nourani, Mehrdad; Gupta, Gopal; Tamil, Lakshman

    2016-08-01

    3D visualization of breast tumors are shown to be effective by previous studies. In this paper, we introduce a new augmented reality application that can help doctors and surgeons to have a more accurate visualization of breast tumors; this system uses a marker-based image-processing technique to render a 3D model of the tumors on the body. The model can be created using a combination of breast 3D mammography by experts. We have tested the system using an Android smartphone and a head-mounted device. This proof of concept can be useful for oncologists to have a more effective screening, and surgeons to plan the surgery.

  12. Pulmonary Embolism with Vertebral Augmentation Procedures

    Directory of Open Access Journals (Sweden)

    Swetha Bopparaju

    2013-01-01

    Full Text Available With the prevalence of an aging American population on the rise, osteoporotic vertebral fractures are becoming a common occurrence, resulting in an increase in vertebral augmentation procedures and associated complications such as cement leakage, vertebral compressions, and pulmonary embolism. We describe a patient who presented with respiratory distress three years following kyphoplasty of the lumbar vertebra. Computed tomography (CT angiogram of the chest confirmed the presence of polymethylmethacrylate (PMMA cement in the lung fields and pulmonary vessels. We conducted a systematic review of the published literature identifying effective management strategies for the treatment of vertebroplasty-associated pulmonary embolism.

  13. Extended overview techniques for outdoor augmented reality.

    Science.gov (United States)

    Veas, Eduardo; Grasset, Raphaël; Kruijff, Ernst; Schmalstieg, Dieter

    2012-04-01

    In this paper, we explore techniques that aim to improve site understanding for outdoor Augmented Reality (AR) applications. While the first person perspective in AR is a direct way of filtering and zooming on a portion of the data set, it severely narrows overview of the situation, particularly over large areas. We present two interactive techniques to overcome this problem: multi-view AR and variable perspective view. We describe in details the conceptual, visualization and interaction aspects of these techniques and their evaluation through a comparative user study. The results we have obtained strengthen the validity of our approach and the applicability of our methods to a large range of application domains.

  14. Freegaming: Mobile, Collaborative, Adaptive and Augmented Exergaming

    Directory of Open Access Journals (Sweden)

    Levent Görgü

    2012-01-01

    Full Text Available Addressing the obesity epidemic that plagues many societies remains an outstanding public health issue. One innovative approach to addressing this problem is Exergaming. A combination of Exercise and Gaming, the objective is to motivate people participate in exercise regimes, usually in their home environment. In this article a more holistic interpretation of this exercise paradigm is proposed. Freegaming augments Exergaming in a number of key dimensions but especially through the promotion of games in outdoor mobile contexts and within a social environment. The design and implementation of a platform for Freegaming is described and illustrated through the description of a sample game.

  15. Increase of Visible Veins After Breast Augmentation A Retrospective Analysis of 78 Consecutive Breast Augmentation Patients

    NARCIS (Netherlands)

    Andonakis, Yuri; van der Lei, Berend

    2009-01-01

    A retrospective study was undertaken to determine file pre- and postoperative presence of visible veins in the skin across the breast of patients seeking breast augmentation, and the impact of this phenomenon oil patient satisfaction. From a series of 97 consecutive patients who underwent cosmetic

  16. Augmenting Your Own Reality: Student Authoring of Science-Based Augmented Reality Games

    Science.gov (United States)

    Klopfer, Eric; Sheldon, Josh

    2010-01-01

    Augmented Reality (AR) simulations superimpose a virtual overlay of data and interactions onto a real-world context. The simulation engine at the heart of this technology is built to afford elements of game play that support explorations and learning in students' natural context--their own community and surroundings. In one of the more recent…

  17. The development of augmented video system on postcards

    Science.gov (United States)

    Chen, Chien-Hsu; Chou, Yin-Ju

    2013-03-01

    This study focuses on development of augmented video system on traditional picture postcards. The system will provide users to print out the augmented reality marker on the sticker to stick on the picture postcard, and it also allows users to record their real time image and video to augment on that stick marker. According dynamic image, users can share travel moods, greeting, and travel experience to their friends. Without changing in the traditional picture postcards, we develop augmented video system on them by augmented reality (AR) technology. It not only keeps the functions of traditional picture postcards, but also enhances user's experience to keep the user's memories and emotional expression by augmented digital media information on them.

  18. Unique self-anhydride formation in the degradation of cytidine-5'-monophosphosialic acid (CMP-Neu5Ac) and cytidine-5'-diphosphosialic acid (CDP-Neu5Ac) and its application in CMP-sialic acid analogue synthesis.

    Science.gov (United States)

    Kajihara, Yasuhiro; Nishigaki, Sachiko; Hanzawa, Daisuke; Nakanishi, Go; Okamoto, Ryo; Yamamoto, Naoki

    2011-06-27

    Sialyloligosaccharides are synthesised by various glycosyltransferases and sugar nucleotides. All of these nucleotides are diphosphate compounds except for cytidine-5'-monophosphosialic acid (CMP-Neu5Ac). To obtain an insight into why cytidine-5'-diphosphosialic acid (CDP-Neu5Ac) has not been used for the sialyltransferase reaction and why it is not found in biological organisms, the compound was synthesised. This synthesis provided the interesting finding that the carboxylic acid moiety of the sialic acid attacks the attached phosphate group. This interaction yields an activated anhydride between carboxylic acid and the phosphate group and leads to hydrolysis of the pyrophosphate linkage. The mechanism was demonstrated by stable isotope-labelling experiments. This finding suggested that CMP-Neu5Ac might also form the corresponding anhydride structure between carboxylic acid and phosphate, and this seems to be the reason why CMP-Neu5Ac is acid labile in relation to other sugar nucleotides. To confirm the role of the carboxylic acid, CMP-Neu5Ac derivatives in which the carboxylic acid moiety in the sialic acid was substituted with amide or ester groups were synthesised. These analogues clearly exhibited resistance to acid hydrolysis. This result indicated that the carboxylic acid of Neu5Ac is associated with its stability in solution. This finding also enabled the development of a novel chemical synthetic method for CMP-Neu5Ac and CMP-sialic acid derivatives. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Preconditioning stimuli that augment chromaffin cell secretion.

    Science.gov (United States)

    Tapia, Laura; García-Eguiagaray, Josefina; García, Antonio G; Gandía, Luis

    2009-04-01

    We have investigated here whether a preconditioned stimulation of nicotinic and muscarinic receptors augmented the catecholamine release responses elicited by supramaximal 3-s pulses of 100 muM acetylcholine (100ACh) or 100 mM K(+) (100K(+)) applied to fast-perifused bovine adrenal chromaffin cells. Threshold concentrations of nicotine (1-3 muM) that caused only a tiny secretion did, however, augment the responses elicited by 100ACh or 100K(+) by 2- to 3.5-fold. This effect was suppressed by mecamylamine and by Ca(2+) deprivation, was developed with a half-time (t(1/2)) of 1 min, and was reversible. The nicotine effect was mimicked by threshold concentrations of ACh, choline, epibatidine, and oxotremorine-M but not by methacholine. Threshold concentrations of K(+) caused lesser potentiation of secretion compared with that of threshold nicotine. The data are compatible with an hypothesis implying 1) that continuous low-frequency sympathetic discharge places chromaffin cells at the adrenal gland in a permanent "hypersensitive" state; and 2) this allows an explosive secretion of catecholamines by high-frequency sympathetic discharge during stress.

  20. The educational possibilities of Augmented Reality

    Directory of Open Access Journals (Sweden)

    Julio Cabero Almenara

    2016-01-01

    Full Text Available A large number of emergent technologies have been acquiring a strong impulse in recent years. One of these emergent technologies is Augmented Reality (RA, which will surely have a high level of penetration into all our educational centers, including universities, in the next 3 to 5 years, as a number of different reports have already highlighted. The present paper shows various elements which, in our opinion, play an essential role when it comes to the incorporation of Augmented Reality into teaching, stressing the fact that this incorporation should not entail a technological problem but an educational and didactic issue. A mention is additionally made of several studies which have been performed with regard to the didactic exploitation of this emergent technology, as well as to the potential that it offers us. Our study forms part of an R&D&I initiative undertaken within the framework of the Plan Estatal de Fomento de la Investigación Científica y Técnica de Excelencia 2013-2016 [2013-16 State (National Plan for the Promotion of Excellence Scientific and Technical Research], with reference EDU2014-57446-P.

  1. Augmented reality in bone tumour resection

    Science.gov (United States)

    Park, Y. K.; Gupta, S.; Yoon, C.; Han, I.; Kim, H-S.; Choi, H.; Hong, J.

    2017-01-01

    Objectives We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. Methods We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. Results The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137–143. PMID:28258117

  2. Boosting physics education through mobile augmented reality

    Science.gov (United States)

    Crǎciun, Dana; Bunoiu, Mǎdǎlin

    2017-12-01

    The integration of collaborative applications, based on modern learning technologies and the Internet, of various visualization techniques and digital strategies in open, flexible modern learning environments which facilitate access to resources, represents a challenge for physics teachers in Romania in general, and for novice teachers in particular. Although large efforts have been made worldwide to invest in educational technologies, their impact on the students' learning outcomes is quite modest. In this paper, we describe and analyze various curricular and extracurricular activities specifically designed for and undertaken by pre-service physics teachers. These activities employ new educational technologies, mobile augmented reality (MAR) and are based on modern teaching and learning theories. MAR is an extension for mobile devices of augmented reality, an interactive and in real time combination, of real and virtual objects overlaid in the real environment. The obtained results show that pre-service physics teachers are confident in using MAR in their teaching and learning activities, and consider that the activities performed helped them develop the skills necessary for science teachers in a technology-based society and to reflect upon the role of technology in the current Romanian educational context.

  3. Flow interaction of diffuser augmented wind turbines

    Science.gov (United States)

    Göltenbott, U.; Ohya, Y.; Yoshida, S.; Jamieson, P.

    2016-09-01

    Up-scaling of wind turbines has been a major trend in order to reduce the cost of energy generation from the wind. Recent studies however show that for a given technology, the cost always rises with upscaling, notably due to the increased mass of the system. To reach capacities beyond 10 MW, multi-rotor systems (MRS) have promising advantages. On the other hand, diffuser augmented wind turbines (DAWTs) can significantly increase the performance of the rotor. Up to now, diffuser augmentation has only been applied to single small wind turbines. In the present research, DAWTs are used in a multi-rotor system. In wind tunnel experiments, the aerodynamics of two and three DAWTs, spaced in close vicinity in the same plane normal to a uniform flow, have been analysed. Power increases of up to 5% and 9% for the two and three rotor configurations are respectively achieved in comparison to a stand-alone turbine. The physical dynamics of the flows are analysed on the basis of the results obtained with a stand-alone turbine.

  4. Prospects for optogenetic augmentation of brain function

    Directory of Open Access Journals (Sweden)

    Sarah eJarvis

    2015-11-01

    Full Text Available The ability to optically control neural activity opens up possibilities for the restoration of normal function following neurological disorders. The temporal precision, spatial resolution and neuronal specificity that optogenetics offers is unequalled by other available methods, so will it be suitable for not only restoring but also extending brain function? As the first demonstrations of optically ``implanted'' novel memories emerge, we examine the suitability of optogenetics as a technique for extending neural function. While optogenetics is an effective tool for altering neural activity, the largest impediment for optogenetics in neural augmentation is our systems level understanding of brain function. Furthermore, a number of clinical limitations currently remain as substantial hurdles for the applications proposed. While neurotechnologies for treating brain disorders and interfacing with prosthetics have advanced rapidly in the past few years, partially addressing some of these critical problems, optogenetics is not yet suitable for use in humans. Instead we conclude that for the immediate future, optogenetics is the neurological equivalent of the 3D printer: its flexibility providing an ideal tool for testing and prototyping solutions for treating brain disorders and augmenting brain function.

  5. [Arthroscopic rotator cuff repair with patch augmentation].

    Science.gov (United States)

    Flury, M

    2012-11-01

    SURGICAL OBJECTIVE: Augmentation of the rotator cuff with an ECM patch during arthroscopic rotator cuff repair is performed in order to unload the reconstruction and to activate biological healing. Reconstructable rotator cuff ruptures with reduced tendon quality. Non-reconstructable tendon defects. After tendon reconstruction the graft is shuttled and fixed on the cuff with two medially placed pulling sutures. With two lateral sutures the graft is pulled laterally over the reconstructed cuff and on the lateral tuberculum majus. Immobilization in an abduction pillow for 6 weeks with passive motion, active motion the next 6 weeks, and weight bearing after 12 weeks. Eight patients with a reconstructable re-rupture were augmented with an ECM patch. Short-term results after 6 months showed 5 (62.5%) healed tendons, 1 complete (12.5%) and 2 incomplete re-ruptures (25%). The CS (Constant Score) and SSV (Subjective Shoulder Value) were improved from 51 to 57% and 51 to 71%, which was not significant (p > 0.05). The Oxford shoulder score improved significantly from 21 to 38 (p < 0.05). There were no relevant intra- or postoperative complications.

  6. Recent Development of Augmented Reality in Surgery: A Review

    OpenAIRE

    P. Vávra; Roman,J.; P. Zonča; P. Ihnát; M. Němec; Kumar, J; Habib, N; El-Gendi, A.

    2017-01-01

    Introduction. The development augmented reality devices allow physicians to incorporate data visualization into diagnostic and treatment procedures to improve work efficiency, safety, and cost and to enhance surgical training. However, the awareness of possibilities of augmented reality is generally low. This review evaluates whether augmented reality can presently improve the results of surgical procedures. Methods. We performed a review of available literature dating from 2010 to November 2...

  7. Augmented sculptures: what you see is not what you see

    OpenAIRE

    Artut, Selçuk Hüseyin; Artut, Selcuk Huseyin

    2015-01-01

    The idea of Augmented Reality Technologies enhances our ability to perceive a location with additional 3D visual elements. A point of interest becomes meta-constructed with addition of extended layers via augmented space elements. Augmented Reality presents us a virtually enriched version of a visually noticeable reality world which already exists and can easily be seen. In this article, in addition to questioning the representative existence of the art object in the work of art called “What ...

  8. Maintenance applications of augmented reality for the Chinese aerospace industry

    OpenAIRE

    Ou, Peng

    2011-01-01

    Since augmented reality has not reached full maturity in use, it is not widely adopted within the aerospace industry. According to the literature review, minimal research efforts have been conducted to assess the cost-benefit or cost- effectiveness of augmented reality so far. Moreover, to the best of researcher’s knowledge, no research has been carried out to develop a systematic process for selecting and implementing augmented reality within the Chinese aerospace industry....

  9. AUGMENTED REALITY - STATE OF KNOWLEDGE, USE AND EXPERIMENTATION

    OpenAIRE

    Mihaela Filofteia TUTUNEA

    2013-01-01

    Technologies for augmenting reality have been consolidated during the last decades, extending their applicability to more and more socio-economic areas. The rapid evolution of mobile technologies and virtualization of the digital environment have created auspicious conditions for massive extension and implementation of solutions for augmenting reality at global level. Experience has already shown that augmented reality, alongside virtual reality can offer very important support so...

  10. Augmented Reality in Tourism – Research and Applications Overview

    OpenAIRE

    Kečkeš, Anabel L.; Igor Tomičić

    2017-01-01

    Augmented reality is a complex interdisciplinary field utilizing information technologies in diverse areas such as medicine, education, architecture, industry, tourism and others, augmenting the real-time, real-world view with additional superimposed information in chosen format(s). The aim of this paper is to present an overview of both research and application aspects of using augmented reality technologies in tourism domain. While most research, and especially applications, are dealing wit...

  11. Consumer Experience With Augmented Reality At Brands' Events

    National Research Council Canada - National Science Library

    Ana Javornik; Andreina Mandelli

    2013-01-01

    .... This exploratory study assesses the appropriateness of the variables of interactivity, telepresence and vividness for evaluating the customer experience with augmented reality at brands' events...

  12. Competitive Intelligence Analysis of Augmented Reality Technology Using Patent Information

    National Research Council Canada - National Science Library

    Byeongki Jeong; Janghyeok Yoon

    2017-01-01

    .... Despite the growing attraction of augmented reality, trend analyses in this emerging technology have relied on qualitative literature review, failing to provide comprehensive competitive intelligence...

  13. Exploring Alternative Radiolabeling Strategies for Sialic Acid-Binding Immunoglobulin-Like Lectin 9 Peptide: [68Ga]Ga- and [18F]AlF-NOTA-Siglec-9

    Directory of Open Access Journals (Sweden)

    Olli Moisio

    2018-01-01

    Full Text Available Amino acid residues 283–297 from sialic acid-binding immunoglobulin-like lectin 9 (Siglec-9 form a cyclic peptide ligand targeting vascular adhesion protein-1 (VAP-1. VAP-1 is associated with the transfer of leukocytes from blood to tissues upon inflammation. Therefore, analogs of Siglec-9 peptide are good candidates for visualizing inflammation non-invasively using positron emission tomography (PET. Gallium-68-labeled 1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid (DOTA-conjugated Siglec-9 has been evaluated extensively for this purpose. Here, we explored two alternative strategies for radiolabeling Siglec-9 peptide using a 1,4,7-triazacyclononane-triacetic acid (NOTA-chelator to bind [68Ga]Ga or [18F]AlF. The radioligands were evaluated by in vivo PET imaging and ex vivo γ-counting of turpentine-induced sterile skin/muscle inflammation in Sprague-Dawley rats. Both tracers showed clear accumulation in the inflamed tissues. The whole-body biodistribution patterns of the tracers were similar.

  14. An exposed carboxyl group on sialic acid is essential for gangliosides to inhibit calcium uptake via the sarco/endoplasmic reticulum Ca2+-ATPase: relevance to gangliosidoses.

    Science.gov (United States)

    Ginzburg, Luba; Li, Su-Chen; Li, Yu-Teh; Futerman, Anthony H

    2008-01-01

    We previously observed that gangliosides GM2, GM1, and GM3 inhibit Ca2+-uptake via the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) in neurons and in brain microsomes. We now systematically examine the effect of various gangliosides and their analogs on Ca2+-uptake via SERCA and demonstrate that an exposed carboxyl group on the ganglioside sialic acid residue is required for inhibition. Thus, asialo-GM2 and asialo-GM1 have no inhibitory effect, and modifications of the carboxyl group of GM1 and GM2 into a hydroxymethyl residue (CH2OH), a methyl ester (COOCH3) or a taurine-conjugated amide (CONHCH2CH2SO3H) drastically diminish their inhibitory activities. We also demonstrate that the saccharides must be attached to a ceramide backbone in order to inhibit SERCA as the ceramide-free ganglioside saccharides only inhibit SERCA to a minimal extent. Finally, we attempted to use the ceramide-free ganglioside saccharides to antagonize the effects of the gangliosides on SERCA; although some reversal was observed, the inhibitory effects of the gangliosides were not completely abolished.

  15. Sialic acid deposition impairs the utility of AAV9, but not peptide-modified AAVs for brain gene therapy in a mouse model of lysosomal storage disease.

    Science.gov (United States)

    Chen, Yong Hong; Claflin, Kristin; Geoghegan, James C; Davidson, Beverly L

    2012-07-01

    Recombinant vector systems have been recently identified that when delivered systemically can transduce neurons, glia, and endothelia in the central nervous system (CNS), providing an opportunity to develop therapies for diseases affecting the brain without performing direct intracranial injections. Vector systems based on adeno-associated virus (AAV) include AAV serotype 9 (AAV9) and AAVs that have been re-engineered at the capsid level for CNS tropism. Here, we performed a head-to-head comparison of AAV9 and a capsid modified AAV for their abilities to rescue CNS and peripheral disease in an animal model of lysosomal storage disease (LSD), the mucopolysacharidoses (MPS) VII mouse. While the peptide-modified AAV reversed cognitive deficits, improved storage burden in the brain, and substantially prolonged survival, we were surprised to find that AAV9 provided no CNS benefit. Additional experiments demonstrated that sialic acid, a known inhibitor of AAV9, is elevated in the CNS of MPS VII mice. These studies highlight how disease manifestations can dramatically impact the known tropism of recombinant vectors, and raise awareness to assuming similar transduction profiles between normal and disease models.

  16. Anion exchange chromatographic distribution of human monoclonal immunoglobulin G is determined by heavy chain subclass and level of sialic acid expression

    Directory of Open Access Journals (Sweden)

    Ilić Vesna

    2012-01-01

    Full Text Available Anion exchange chromatography is widely accepted method for purification of immunoglobulins. In this work, we used human monoclonal immunoglobulin G (IgG with structure and solubility of normal human IgG as a model for studying chromatographic behavior of particular molecular forms of IgG. Human sera with monoclonal IgG were fractionated on strong anion exchanger, Q Sepharose Fast Flow. With 20 mM Tris pH 7.5 as a start buffer, 42% of human monoclonal IgG passed through column, and 58% of them remained adsorbed. Bound monoclonal IgG were eluted from the exchanger by linear increasing of concentration of NaCl from 0 to 0.5 M. Chromatographic distribution of human monoclonal IgG correlated with their electrophoretic mobility in agarose gels, and it was dependent on γ heavy chain isotype. Light chain type, as well as serum concentration of monoclonal IgG did not influence their chromatographic behavior. The level of heavy chain sialic acid expression, but not of galactose and N-acetylglucosamine, significantly determined chromatographic distribution of serum monoclonal IgG. Additionally to the information on the chromatographic behavior of human monoclonal IgG, we believe that presented data could provide useful information about the possible use of Q Sepharose Fast Flow matrix for the isolation of specific molecular forms of human IgG.

  17. A missense single-nucleotide polymorphism in the sialic acid acetylesterase (SIAE) gene is associated with anti-PIT-1 antibody syndrome.

    Science.gov (United States)

    Yamamoto, Masaaki; Iguchi, Genzo; Bando, Hironori; Fukuoka, Hidenori; Suda, Kentaro; Takahashi, Michiko; Nishizawa, Hitoshi; Matsumoto, Ryusaku; Tojo, Katsuyoshi; Mokubo, Atsuko; Ogata, Tsutomu; Takahashi, Yutaka

    2014-01-01

    A novel clinical entity related to autoimmune polygladular syndrome (APS) termed "anti-PIT-1 antibody syndrome" is characterized by a presence of circulating autoantibody against the pituitary-specific transcriptional factor-1 (PIT-1) with acquired specific defect in GH, PRL, and TSH. Although autoimmunity to PIT-1 has been suggested, the underlying mechanisms remain to be elucidated. Sialic acid acetylesterase (SIAE) plays a crucial role in regulating the threshold of autoantibody production of B-cells and the defective variants of SIAE are associated with an increased risk of various autoimmune diseases such as type 1 diabetes (T1DM). To explore the link between anti-PIT-1 antibody syndrome and SIAE, we analyzed SIAE gene in 3 patients with anti-PIT-1 antibody syndrome and 200 healthy control subjects, and compared the prevalence of single nucleotide polymorphisms. Intriguingly, we found A467V SIAE variants (c.1400C>T, rs7941523) in a heterozygous state in all the patients with anti-PIT-1 antibody syndrome, while we detected in 6 % of control subjects, in which the prevalence was significantly increased in the patients (PPIT-1 antibody syndrome, present data imply a novel aspect of the pathogenesis in this disease.

  18. Twoplex (12/13) C6 aniline stable isotope and linkage-specific sialic acid labeling 2D-LC-MS workflow for quantitative N-glycomics.

    Science.gov (United States)

    Albrecht, Simone; Mittermayr, Stefan; Smith, Josh; Martín, Silvia Millán; Doherty, Margaret; Bones, Jonathan

    2017-01-01

    Quantitative glycomics represents an actively expanding research field ranging from the discovery of disease-associated glycan alterations to the quantitative characterization of N-glycans on therapeutic proteins. Commonly used analytical platforms for comparative relative quantitation of complex glycan samples include MALDI-TOF-MS or chromatographic glycan profiling with subsequent data alignment and statistical evaluation. Limitations of such approaches include run-to-run technical variation and the potential introduction of subjectivity during data processing. Here, we introduce an offline 2D LC-MS(E) workflow for the fractionation and relative quantitation of twoplex isotopically labeled N-linked oligosaccharides using neutral (12) C6 and (13) C6 aniline (Δmass = 6 Da). Additional linkage-specific derivatization of sialic acids using 4-(4,6-dimethoxy-1,3,5-trizain-2-yl)-4-methylmorpholinium chloride offered simultaneous and advanced in-depth structural characterization. The potential of the method was demonstrated for the differential analysis of structurally defined N-glycans released from serum proteins of patients diagnosed with various stages of colorectal cancer. The described twoplex (12) C6 /(13) C6 aniline 2D LC-MS platform is ideally suited for differential glycomic analysis of structurally complex N-glycan pools due to combination and analysis of samples in a single LC-MS injection and the associated minimization in technical variation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Sialic Acid-Binding Immunoglobulin-like Lectin G Promotes Atherosclerosis and Liver Inflammation by Suppressing the Protective Functions of B-1 Cells

    Directory of Open Access Journals (Sweden)

    Sabrina Gruber

    2016-03-01

    Full Text Available Atherosclerosis is initiated and sustained by hypercholesterolemia, which results in the generation of oxidized LDL (OxLDL and other metabolic byproducts that trigger inflammation. Specific immune responses have been shown to modulate the inflammatory response during atherogenesis. The sialic acid-binding immunoglobulin-like lectin G (Siglec-G is a negative regulator of the functions of several immune cells, including myeloid cells and B-1 cells. Here, we show that deficiency of Siglec-G in atherosclerosis-prone mice inhibits plaque formation and diet-induced hepatic inflammation. We further demonstrate that selective deficiency of Siglec-G in B cells alone is sufficient to mediate these effects. Levels of B-1 cell-derived natural IgM with specificity for OxLDL were significantly increased in the plasma and peritoneal cavity of Siglec-G-deficient mice. Consistent with the neutralizing functions of OxLDL-specific IgM, Siglec-G-deficient mice were protected from OxLDL-induced sterile inflammation. Thus, Siglec-G promotes atherosclerosis and hepatic inflammation by suppressing protective anti-inflammatory effector functions of B cells.

  20. Sialic acid and sialyl-lactose glyco-conjugates: design, synthesis and binding assays to lectins and swine influenza H1N1 virus.

    Science.gov (United States)

    Zevgiti, Stella; Zabala, Juliana Gonzalez; Darji, Ayub; Dietrich, Ursula; Panou-Pomonis, Eugenia; Sakarellos-Daitsiotis, Maria

    2012-01-01

    The terminal parts of the influenza hemagglutinin (HA) receptors α2,6- and α2,3-sialyllactoses were conjugated to an artificial carrier, named sequential oligopeptide carrier (SOC(4) ), to formulate human and avian receptor mimics, respectively. SOC(4) , formed by the tripeptide unit Lys-Aib-Gly, adopts a rigid helicoids-type conformation, which enables the conjugation of biomolecules to the Lys-N(ε) H(2) groups. By doing so, it preserves their initial conformations and functionalities of the epitopes. We report that SOC(4) -glyco-conjugate bearing two copies of the α2,6-sialyllactose is specifically recognized by the biotinylated Sambucus nigra (elderberry) bark lectin, which binds preferentially to sialic acid in an α2,6-linkage. SOC(4) -glyco-conjugate bearing two copies of the α2,3-sialyllactose was not recognized by the biotinylated Maackia amurensis lectin, despite its well-known α2,3-sialyl bond specificity. However, preliminary immune blot assays showed that H1N1 virus binds to both the SOC(4) -glyco-conjugates immobilized onto nitrocellulose membrane. It is concluded that Ac-SOC(4) [(Ac)(2) ,(3'SL-Aoa)(2) ]-NH(2) 5 and Ac-SOC(4) [(Ac)(2) ,(6'SL-Aoa)(2) ]-NH(2) 6 mimic the HA receptors. These findings could be useful for easy screening of binding and inhibition assays of virus-receptor interactions. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.

  1. Development of the augmented musculature device.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Pankretz, Ty

    2004-12-01

    We developed an Augmented Musculature Device (AMD) that assists the movements of its wearer. It has direct application to aiding military and law enforcement personnel, the neurologically impaired, or those requiring any type of cybernetic assistance. The AMD consists of a collection of artificial muscles, each individually actuated, strategically placed along the surface of the human body. The actuators employed by the AMD are known as 'air muscles' and operate pneumatically. They are commercially available from several vendors and are relatively inexpensive. They have a remarkably high force-to-weight ratio--as high as 400:1 (as compared with 16:1 typical of DC motors). They are flexible and elastic, even when powered, making them ideal for interaction with humans.

  2. Visualizing Sea Level Rise with Augmented Reality

    Science.gov (United States)

    Kintisch, E. S.

    2013-12-01

    Looking Glass is an application on the iPhone that visualizes in 3-D future scenarios of sea level rise, overlaid on live camera imagery in situ. Using a technology known as augmented reality, the app allows a layperson user to explore various scenarios of sea level rise using a visual interface. Then the user can see, in an immersive, dynamic way, how those scenarios would affect a real place. The first part of the experience activates users' cognitive, quantitative thinking process, teaching them how global sea level rise, tides and storm surge contribute to flooding; the second allows an emotional response to a striking visual depiction of possible future catastrophe. This project represents a partnership between a science journalist, MIT, and the Rhode Island School of Design, and the talk will touch on lessons this projects provides on structuring and executing such multidisciplinary efforts on future design projects.

  3. Out of the Cube: Augmented Rubik's Cube

    Directory of Open Access Journals (Sweden)

    Oriel Bergig

    2011-01-01

    Full Text Available Computer gaming habits have a tendency to evolve with technology, the best being ones that immerse both our imagination and intellect. Here, we describe a new game platform, an Augmented Reality Rubik's cube. The cube acts simultaneously as both the controller and the game board. Gameplay is controlled by the cube, and game assets are rendered on top of it. Shuffling and tilting operations on the cube are mapped to game interaction. We discuss the game design decisions involved in developing a game for this platform, as well as the technological challenges in implementing it. Ultimately, we describe two games and discuss the conclusions of an informal user study based on those games.

  4. Augmented reality i en industriell tillverkningsprocess

    OpenAIRE

    Wass, Anton; Löwenborg Forsberg, Eddie

    2017-01-01

    Med den digitalisering som sker just nu i den industriella världen väcks stor nyfikenhet på hur framtidens tekniker såsom “Augmented Reality” kan appliceras i industriella tillverkningsprocesser. Målet med examensarbetet var att undersöka om och hur AR-teknik kan utnyttjas i industrin för att förbättra nuvarande arbetsprocesser. Två prototyper utvecklades för AR-glasögonen Microsoft HoloLens och utvärderades genom att jämföra tidigare arbetssätt med nya. Testerna av prototyperna visade att ef...

  5. Digital Facial Augmentation for Interactive Entertainment

    Directory of Open Access Journals (Sweden)

    Naoto Hieda

    2015-08-01

    Full Text Available Digital projection technology allows for effective and entertaining spatial augmented reality applications. Leveraging the capabilities of reasonably accurate object tracking using commodity cameras and/or depth sensors to determine the 3D position and pose of objects in real time, it is possible to project dynamic graphical content on arbitrary surfaces, such as a person’s face. Coupling these capabilities with a simple drawing application, participants can have the experience of "painting" on someone’s face, or even on their own, by observing the projection in a mirror. Similarly, integrating 2D rigid-body, fluid and gravity simulation, one may interact with virtual objects projected on their own face or body.

  6. Augmented reality approach for metabolic pathways teaching

    Directory of Open Access Journals (Sweden)

    Juan Carlos Vega Garzón

    2014-12-01

    Full Text Available A glycolysis paper puzzle has been used as strategy to teach metabolic pathways, but this kind of game demands a higher number of instructors and limits the follow up of the students’ difficulties. A technology called Augmented Reality (AR was applied to enable the puzzle usage in large audiences, and to provid feedback to students and instructors. Drafted as flashcards readable by an app installed in tablets, it conveys information as molecules 3D-structure, clues for correct assembling of the metabolic pathway and results of student progression in the activity. Such technological improvement brought more autonomy to students for solving proposed exercises and an embedded performance data collection system helpful to understand,and after to unravel students’ difficulties.

  7. Temporal Coherence Strategies for Augmented Reality Labeling.

    Science.gov (United States)

    Madsen, Jacob Boesen; Tatzqern, Markus; Madsen, Claus B; Schmalstieg, Dieter; Kalkofen, Denis

    2016-04-01

    Temporal coherence of annotations is an important factor in augmented reality user interfaces and for information visualization. In this paper, we empirically evaluate four different techniques for annotation. Based on these findings, we follow up with subjective evaluations in a second experiment. Results show that presenting annotations in object space or image space leads to a significant difference in task performance. Furthermore, there is a significant interaction between rendering space and update frequency of annotations. Participants improve significantly in locating annotations, when annotations are presented in object space, and view management update rate is limited. In a follow-up experiment, participants appear to be more satisfied with limited update rate in comparison to a continuous update rate of the view management system.

  8. Googles Augmented-Reality-Game "Ingress"

    Directory of Open Access Journals (Sweden)

    Karl H. Stingeder

    2013-12-01

    Full Text Available Das an das "Geocoaching"-Spielprinzip erinnernde Augmented-­Reality-Game "Ingress" ist auf allen mit Android-Betriebssystem ausgestatteten Smartphones spielbar. Das Alleinstellungsmerkmal des Spiels ist gleich­zeitig auch das beste Patent-Rezept für bzw. gegen notorisches "Couch-Potato-ing": Das Game-Design des "Draußenspiels" erfordert jedoch stets die physische Anwesenheit der SpielerInnen am realen Ort des Geschehens, meist touristisch attraktive Sehenswürdigkeiten und architektonisch markante Plätze. Sobald "Ingress" per App am Smart­phone gestartet wird, stehen Interaktionen und Machtverhältnisse auf dem Handy-Display im Dreh- und Angelpunkt des Geschehens. Die Spielgrafik ist auf das Wesentliche reduziert und erinnert an die Optik von Videospielen der 80er Jahre. "Ingress" im Allgemeinen sowie "Magnus13", die erste von Google organisierte Fan-Veranstaltung Österreichs mit mehreren Hundert TeilnehmerInnen und ist mit einer "digitalen Schnitzeljagd" vergleichbar: Gemeinsam ist der klassischen "Schnitzeljagd" und dem digitalen "Schere-Schein-Papier" Prinzip von "Ingress" die tragende Rolle des im Spiel entstehenden Gemeinschaftsgefühls, welche in einer hohen Langzeitmotivation mündet. Trotz aller Euphorie, ob des unkonventionellen Augmented-Reality-Spielkonzepts und des in Folge der sozialen Dynamik außergewöhnlichen Sucht­potentials, ist angesichts von Edward Snowden und vielfältiger NSA-Abhörmaßnahmen, eine gesunde Portion Skepsis angebracht: Welchen Zweck erfüllt "Ingress"? Gibt es ein verhülltes "Mittel zum Zweck"? Welche Gefahren bestehen mit einer systematischen Auswertung des umfangreichen, ortsrelevanten Daten-Sammelsuriums? "Ingress" verdeutlicht trotz aller Risiken den soziokulturellen Bedeutungswandel des digitalen Spiels: Spiele per se und das Spiel als soziale Interaktion sind aktuell dabei, alle Bereiche unseres Lebens zu erfassen.

  9. Augmented reality in a tumor resection model.

    Science.gov (United States)

    Chauvet, Pauline; Collins, Toby; Debize, Clement; Novais-Gameiro, Lorraine; Pereira, Bruno; Bartoli, Adrien; Canis, Michel; Bourdel, Nicolas

    2018-03-01

    Augmented Reality (AR) guidance is a technology that allows a surgeon to see sub-surface structures, by overlaying pre-operative imaging data on a live laparoscopic video. Our objectives were to evaluate a state-of-the-art AR guidance system in a tumor surgical resection model, comparing the accuracy of the resection with and without the system. Our system has three phases. Phase 1: using the MRI images, the kidney's and pseudotumor's surfaces are segmented to construct a 3D model. Phase 2: the intra-operative 3D model of the kidney is computed. Phase 3: the pre-operative and intra-operative models are registered, and the laparoscopic view is augmented with the pre-operative data. We performed a prospective experimental study on ex vivo porcine kidneys. Alginate was injected into the parenchyma to create pseudotumors measuring 4-10 mm. The kidneys were then analyzed by MRI. Next, the kidneys were placed into pelvictrainers, and the pseudotumors were laparoscopically resected. The AR guidance system allows the surgeon to see tumors and margins using classical laparoscopic instruments, and a classical screen. The resection margins were measured microscopically to evaluate the accuracy of resection. Ninety tumors were segmented: 28 were used to optimize the AR software, and 62 were used to randomly compare surgical resection: 29 tumors were resected using AR and 33 without AR. The analysis of our pathological results showed 4 failures (tumor with positive margins) (13.8%) in the AR group, and 10 (30.3%) in the Non-AR group. There was no complete miss in the AR group, while there were 4 complete misses in the non-AR group. In total, 14 (42.4%) tumors were completely missed or had a positive margin in the non-AR group. Our AR system enhances the accuracy of surgical resection, particularly for small tumors. Crucial information such as resection margins and vascularization could also be displayed.

  10. Augmented reality in neurosurgery: a systematic review.

    Science.gov (United States)

    Meola, Antonio; Cutolo, Fabrizio; Carbone, Marina; Cagnazzo, Federico; Ferrari, Mauro; Ferrari, Vincenzo

    2017-10-01

    Neuronavigation has become an essential neurosurgical tool in pursuing minimal invasiveness and maximal safety, even though it has several technical limitations. Augmented reality (AR) neuronavigation is a significant advance, providing a real-time updated 3D virtual model of anatomical details, overlaid on the real surgical field. Currently, only a few AR systems have been tested in a clinical setting. The aim is to review such devices. We performed a PubMed search of reports restricted to human studies of in vivo applications of AR in any neurosurgical procedure using the search terms "Augmented reality" and "Neurosurgery." Eligibility assessment was performed independently by two reviewers in an unblinded standardized manner. The systems were qualitatively evaluated on the basis of the following: neurosurgical subspecialty of application, pathology of treated lesions and lesion locations, real data source, virtual data source, tracking modality, registration technique, visualization processing, display type, and perception location. Eighteen studies were included during the period 1996 to September 30, 2015. The AR systems were grouped by the real data source: microscope (8), hand- or head-held cameras (4), direct patient view (2), endoscope (1), and X-ray fluoroscopy (1) head-mounted display (1). A total of 195 lesions were treated: 75 (38.46 %) were neoplastic, 77 (39.48 %) neurovascular, and 1 (0.51 %) hydrocephalus, and 42 (21.53 %) were undetermined. Current literature confirms that AR is a reliable and versatile tool when performing minimally invasive approaches in a wide range of neurosurgical diseases, although prospective randomized studies are not yet available and technical improvements are needed.

  11. A Systematic Review of Pliance, Tracking, and Augmenting

    NARCIS (Netherlands)

    Kissi, Ama; Hughes, Sean; Mertens, Gaëtan; Barnes-Holmes, Dermot; De Houwer, Jan; Crombez, Geert

    Within relational frame theory, a distinction has been made between three types of rule-governed behavior known as pliance, tracking, and augmenting. This review examined whether there is support for the concepts of pliance, tracking, and augmenting in the experimental analysis of behavior; whether

  12. Routine sensor-augmented pump therapy in type 1 diabetes

    DEFF Research Database (Denmark)

    Nørgaard, Kirsten; Scaramuzza, Andrea; Bratina, Natasa

    2013-01-01

    Sensor-augmented pump (SAP) therapy can improve glycemic control, compared with multiple daily insulin injections or with insulin pump therapy alone, without increasing the risk of hypoglycemia.......Sensor-augmented pump (SAP) therapy can improve glycemic control, compared with multiple daily insulin injections or with insulin pump therapy alone, without increasing the risk of hypoglycemia....

  13. Projector augmented wave method: ab initio molecular dynamics ...

    Indian Academy of Sciences (India)

    http://www.ias.ac.in/article/fulltext/boms/026/01/0033-0041 ... A brief introduction to the projector augmented wave method is given and recent developments are reviewed. The projector augmented wave method is an all-electron method for efficient ab initio molecular dynamics simulations with full wave functions. It extends ...

  14. Buspirone is an effective augmenting agent of serotonin selective re ...

    African Journals Online (AJOL)

    Background. Buspirone has previously been reported to be effective in the augmentation of the antidepressant effect of serotonin selective re-uptake inhibitors (SSRls) in depressed outpatients. We report on buspirone augmentation of SSRls in severe treatment-refractory depression in inpatients. Methods. A retrospective ...

  15. Augmentative biological control of arthropods in Latin America

    NARCIS (Netherlands)

    Lenteren, van J.C.; Bueno, V.H.P.

    2003-01-01

    Augmentative forms of biological control, where natural enemies are periodically introduced, are applied over large areas in various cropping systems in Latin America. About 25% of the world area under augmentative control is situated in this region. Well-known examples are the use of species of the

  16. Augmented Reality, the Future of Contextual Mobile Learning

    Science.gov (United States)

    Sungkur, Roopesh Kevin; Panchoo, Akshay; Bhoyroo, Nitisha Kirtee

    2016-01-01

    Purpose: This study aims to show the relevance of augmented reality (AR) in mobile learning for the 21st century. With AR, any real-world environment can be augmented by providing users with accurate digital overlays. AR is a promising technology that has the potential to encourage learners to explore learning materials from a totally new…

  17. Augmented Local Anaesthesia In Selected Cases Of Thyroidectomy ...

    African Journals Online (AJOL)

    An augmentation of anaesthesia in 12 selected cases of thyroidectomy in a rural practice is presented. The cases were selected according to well defined criteria. The augmentation involved the use of general anaesthesia with ketarmine hydrochloride and diazepam, at the state of mobilizing the superior poles of the gland.

  18. Complications 15 years after breast augmentation with polyacrylamide

    Directory of Open Access Journals (Sweden)

    Habib M. Ghasemi

    2015-06-01

    Full Text Available Polyacrylamide hydrogel (PAAG has been used as an injectable, permanent filler for soft-tissue augmentation for more than two decades. Several complications have been reported worldwide. In this case report, we present a woman with long-term complications 15 years after bilateral breast augmentation with PAAG injections.

  19. AUGMENTED REALITY - STATE OF KNOWLEDGE, USE AND EXPERIMENTATION

    Directory of Open Access Journals (Sweden)

    Mihaela Filofteia TUTUNEA

    2013-12-01

    Full Text Available Technologies for augmenting reality have been consolidated during the last decades, extending their applicability to more and more socio-economic areas. The rapid evolution of mobile technologies and virtualization of the digital environment have created auspicious conditions for massive extension and implementation of solutions for augmenting reality at global level. Experience has already shown that augmented reality, alongside virtual reality can offer very important support solutions in modeling the real world with the aim of extending the human capabilities of perception, allowing the opening of a new phase in the world’s socio-economic development. Starting from the evident tendencies that have manifested at global level in the development and implementation of augmented reality technologies, the paper begins with the presentation of the most important aspects related to augmented reality technologies, highlighting their main areas of application, and presents the study realized for identifying the level of knowledge, use and effective experimentation of augmented reality applications by mobile device users. The results of this study could be very useful to the socio-economic environment, starting with the field of research, continuing with developers and providers of augmented reality solutions, manufacturers and providers of hardware infrastructure support for augmented reality solutions and systems, final users of these solutions, both individuals and businesses, and experimenting digital communities.

  20. Pose estimation for mobile devices and augmented reality

    NARCIS (Netherlands)

    Caarls, J.

    2009-01-01

    In this thesis we introduce the reader to the field of Augmented Reality (AR) and describe aspects of an AR system. We show the current uses in treatment of phobias, games, sports and industry. We present the challenges for Optical See-Through Augmented Reality in which the real world is perceived

  1. Augmented Reality Learning Experiences: Survey of Prototype Design and Evaluation

    Science.gov (United States)

    Santos, Marc Ericson C.; Chen, Angie; Taketomi, Takafumi; Yamamoto, Goshiro; Miyazaki, Jun; Kato, Hirokazu

    2014-01-01

    Augmented reality (AR) technology is mature for creating learning experiences for K-12 (pre-school, grade school, and high school) educational settings. We reviewed the applications intended to complement traditional curriculum materials for K-12. We found 87 research articles on augmented reality learning experiences (ARLEs) in the IEEE Xplore…

  2. Augmenting a Child's Reality: Using Educational Tablet Technology

    Science.gov (United States)

    Tanner, Patricia; Karas, Carly; Schofield, Damian

    2014-01-01

    This study investigates the classroom integration of an innovative technology, augmented reality. Although the process of adding new technologies into a classroom setting can be daunting, the concept of augmented reality has demonstrated the ability to educate students and to assist with their comprehension of a procedural task. One half of the…

  3. The Local Games Lab ABQ: Homegrown Augmented Reality

    Science.gov (United States)

    Holden, Christopher

    2014-01-01

    Experiments in the use of augmented reality games formerly required extensive material resources and expertise to implement above and beyond what might be possible within the usual educational contexts. Currently, the more common availability of hardware in these contexts and the existence of easy-to-use, general purpose augmented reality design…

  4. Potential Use of Augmented Reality in LIS Education

    Science.gov (United States)

    Wójcik, Magdalena

    2016-01-01

    The subject of this article is the use of augmented reality technology in library and information science education. The aim is to determine the scope and potential uses of augmented reality in the education of information professionals. In order to determine the scope and forms of potential use of AR technology in LIS education a two-step…

  5. Pose estimation for mobile devices and augmented reality

    NARCIS (Netherlands)

    Van Vliet, L.J.; Jonker, P.P.; Caarls, J.

    In this thesis we introduce the reader to the field of Augmented Reality (AR) and describe aspects of an AR system. We show the current uses in treatment of phobias, games, sports and industry. We present the challenges for Optical See-Through Augmented Reality in which the real world is perceived

  6. Augmented Reality Learning Experiences: Survey of Prototype Design and Evaluation

    Science.gov (United States)

    Santos, Marc Ericson C.; Chen, Angie; Taketomi, Takafumi; Yamamoto, Goshiro; Miyazaki, Jun; Kato, Hirokazu

    Augmented reality (AR) technology is mature for creating learning experiences for K-12 (pre-school, grade school, and high school) educational settings. We reviewed the applications intended to complement traditional curriculum materials for K-12. We found 87 research articles on augmented reality learning experiences (ARLEs) in the IEEE Xplore…

  7. Augmented Reality at the Tactical and Operational Levels of War

    Science.gov (United States)

    2015-10-24

    currently available AR smart -glasses and AR contact lenses . Microsoft – HoloLens. Microsoft has dedicated over a thousand employees and a billion dollars...Augmented Reality Visors, Glasses, and Contact Lenses .................................................................... 20 How Augmented Reality... contact lenses . As such, they provide continuous access to AR content. With their arrival, AR systems will fundamentally change how users interact

  8. ARLearn: Learning activities and interaction in augmented reality

    NARCIS (Netherlands)

    Ternier, Stefaan; Tabuenca, Bernardo; Specht, Marcus

    2013-01-01

    Ternier, S., Tabuenca, B., & Specht, M. (2012). ARLearn: Learning activities and interaction in augmented reality. In M. Specht, J. Multisilta, & M. Sharples (Eds.), Proceedings of the Mobile Augmented Reality for Education Workshop (pp. 10-13). October, 16-17, 2012, Helsinki, Finland.

  9. International workshop on multimodal virtual and augmented reality (workshop summary)

    NARCIS (Netherlands)

    Hürst, W.O.; Iwai, Daisuke; Balakrishnan, Prabhakaran

    2016-01-01

    Virtual reality (VR) and augmented reality (AR) are expected by many to become the next wave of computing with significant impacts on our daily lives. Motivated by this, we organized a workshop on “Multimodal Virtual and Augmented Reality (MVAR)” at the 18th ACM International Conference on

  10. Augmenting cognition: Reviewing the symbiotic relation between man and machine

    NARCIS (Netherlands)

    Greef, T.E. de; Dongen, C.J.G. van; Grootjen, M.; Lindenberg, J.

    2007-01-01

    One of the goals of augmented cognition is creation of adaptive human-machine collaboration that continually optimizes performance of the human-machine system. Augmented Cognition aims to compensate for temporal limitations in human information processing, for instance in the case of overload,

  11. the use of augmented reality in command and control situation ...

    African Journals Online (AJOL)

    Abel

    Augmented reality is not completely new technology, but rather an interesting combination of existing technologies, ... Augmented reality applications are becoming more popular due to the remarkable progress in ultra-mobile ..... 1) increased loading on operators to provide status reports;. 2) dissemination of status reports;.

  12. Sensor-augmented pump therapy at 36 months

    DEFF Research Database (Denmark)

    Schmidt, Signe; Nørgaard, Kirsten

    2012-01-01

    This follow-up study investigates the metabolic and psychosocial effects of sensor-augmented pump (SAP) therapy in adults with type 1 diabetes 36 months after therapy start.......This follow-up study investigates the metabolic and psychosocial effects of sensor-augmented pump (SAP) therapy in adults with type 1 diabetes 36 months after therapy start....

  13. 14 CFR 91.1061 - Augmented flight crews.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Augmented flight crews. 91.1061 Section 91...) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any flight...

  14. PARAMETERS OF AUGMENTED REALITY AND ITS USE IN EDUCATION

    Directory of Open Access Journals (Sweden)

    JEŘÁBEK, Tomáš

    2013-12-01

    Full Text Available This article examines the issue of augmented reality and possibilities of its application in education. It briefly reports on selected results of a broader survey focused on technological, psychological, physiological and didactical aspects of the issue. It presumes that augmented reality has its unique place in technical teaching tools since it is a technological-perception concept, which in certain didactical situations creates more suitable perceptual environment than real environment itself on one hand, or virtual environment on the other. It focuses on identification of the technological-functional properties and specifics of augmented reality systems and on verification of model examples of augmented reality applications in school practice. It characterizes the course and results of empirical research project based on a descriptive case study exploring the cases of implementing selected application solutions of augmented reality into learning experience in accordance with the model of pro-active action research.

  15. Applying Augmented Reality in practical classes for engineering students

    Science.gov (United States)

    Bazarov, S. E.; Kholodilin, I. Yu; Nesterov, A. S.; Sokhina, A. V.

    2017-10-01

    In this article the Augmented Reality application for teaching engineering students of electrical and technological specialties is introduced. In order to increase the motivation for learning and the independence of students, new practical guidelines on Augmented Reality were developed in the application to practical classes. During the application development, the authors used software such as Unity 3D and Vuforia. The Augmented Reality content consists of 3D-models, images and animations, which are superimposed on real objects, helping students to study specific tasks. A user who has a smartphone, a tablet PC, or Augmented Reality glasses can visualize on-screen virtual objects added to a real environment. Having analyzed the current situation in higher education: the learner’s interest in studying, their satisfaction with the educational process, and the impact of the Augmented Reality application on students, a questionnaire was developed and offered to students; the study involved 24 learners.

  16. Augmented Reality as a Countermeasure for Sleep Deprivation.

    Science.gov (United States)

    Baumeister, James; Dorrlan, Jillian; Banks, Siobhan; Chatburn, Alex; Smith, Ross T; Carskadon, Mary A; Lushington, Kurt; Thomas, Bruce H

    2016-04-01

    Sleep deprivation is known to have serious deleterious effects on executive functioning and job performance. Augmented reality has an ability to place pertinent information at the fore, guiding visual focus and reducing instructional complexity. This paper presents a study to explore how spatial augmented reality instructions impact procedural task performance on sleep deprived users. The user study was conducted to examine performance on a procedural task at six time points over the course of a night of total sleep deprivation. Tasks were provided either by spatial augmented reality-based projections or on an adjacent monitor. The results indicate that participant errors significantly increased with the monitor condition when sleep deprived. The augmented reality condition exhibited a positive influence with participant errors and completion time having no significant increase when sleep deprived. The results of our study show that spatial augmented reality is an effective sleep deprivation countermeasure under laboratory conditions.

  17. Computational modelling of bone augmentation in the spine

    Directory of Open Access Journals (Sweden)

    Sandro D. Badilatti

    2015-10-01

    Full Text Available Computational models are gaining importance not only for basic science, but also for the analysis of clinical interventions and to support clinicians prior to intervention. Vertebroplasty has been used to stabilise compression fractures in the spine for years, yet there are still diverging ideas on the ideal deposition location, volume, and augmentation material. In particular, little is known about the long-term effects of the intervention on the surrounding biological tissue. This review aims to investigate computational efforts made in the field of vertebroplasty, from the augmentation procedure to strength prediction and long-term in silico bone biology in augmented human vertebrae. While there is ample work on simulating the augmentation procedure and strength prediction, simulations predicting long-term effects are lacking. Recent developments in bone remodelling simulations have the potential to show adaptation to cement augmentation and, thus, close this gap.

  18. Augmented Reality in Tourism - Research and Applications Overview

    Directory of Open Access Journals (Sweden)

    Anabel L. Kečkeš

    2017-06-01

    Full Text Available Augmented reality is a complex interdisciplinary field utilizing information technologies in diverse areas such as medicine, education, architecture, industry, tourism and others, augmenting the real-time, real-world view with additional superimposed information in chosen format(s. The aim of this paper is to present an overview of both research and application aspects of using augmented reality technologies in tourism domain. While most research, and especially applications, are dealing with and developing visual-based augmented reality systems, there is a relevant amount of research discussing the utilization of other human senses such as tactioception and audioception, both being discussed within this work. A comprehensive literature analysis within this paper resulted with the identification, compilation and categorization of the key factors having the most relevant impact on the success of utilization of augmented technology in tourism domain.

  19. Augmented reality usage for prototyping speed up

    Directory of Open Access Journals (Sweden)

    Jiří Šťastný

    2011-01-01

    Full Text Available The integral part of production process in many companies is prototyping. Although, these companies commonly have high quality visualization tools (large screen projections, virtual reality, prototyping was never abandoned. There is a number of reasons. The most important is the possibility of model observation from any angle without any physical constraints and its haptic feedback. The interactivity of model adjustments is important as well. The direct work with the model allows the designers to focus on the creative process more than work with a computer. There is still a problem with a difficult adjustability of the model. More significant changes demand completely new prototype or at least longer time for its realization.The first part of the article describes our approach for solution of this problem by means of Augmented Reality. The merging of the real world model and digital objects allows streamline the work with the model and speed up the whole production phase significantly. The main advantage of augmented reality is the possibility of direct manipulation with the scene using a portable digital camera. Also adding digital objects into the scene could be done using identification markers placed on the surface of the model. Therefore it is not necessary to work with special input devices and lose the contact with the real world model. Adjustments are done directly on the model. The key problem of outlined solution is the ability of identification of an object within the camera picture and its replacement with the digital object. The second part of the article is focused especially on the identification of exact position and orientation of the marker within the picture. The identification marker is generalized into the triple of points which represents a general plane in space. There is discussed the space identification of these points and the description of representation of their position and orientation be means of transformation

  20. The Nogo-66 receptor homolog NgR2 is a sialic acid-dependent receptor selective for myelin-associated glycoprotein.

    Science.gov (United States)

    Venkatesh, Karthik; Chivatakarn, Onanong; Lee, Hakjoo; Joshi, Pushkar S; Kantor, David B; Newman, Barbara A; Mage, Rose; Rader, Christoph; Giger, Roman J

    2005-01-26

    The Nogo-66 receptor (NgR1) is a promiscuous receptor for the myelin inhibitory proteins Nogo/Nogo-66, myelin-associated glycoprotein (MAG), and oligodendrocyte myelin glycoprotein (OMgp). NgR1, an axonal glycoprotein, is the founding member of a protein family composed of the structurally related molecules NgR1, NgR2, and NgR3. Here we show that NgR2 is a novel receptor for MAG and acts selectively to mediate MAG inhibitory responses. MAG binds NgR2 directly and with greater affinity than NgR1. In neurons NgR1 and NgR2 support MAG binding in a sialic acid-dependent Vibrio cholerae neuraminidase-sensitive manner. Forced expression of NgR2 is sufficient to impart MAG inhibition to neonatal sensory neurons. Soluble NgR2 has MAG antagonistic capacity and promotes neuronal growth on MAG and CNS myelin substrate in vitro. Structural studies have revealed that the NgR2 leucine-rich repeat cluster and the NgR2 "unique" domain are necessary for high-affinity MAG binding. Consistent with its role as a neuronal MAG receptor, NgR2 is an axonassociated glycoprotein. In postnatal brain NgR1 and NgR2 are strongly enriched in Triton X-100-insoluble lipid rafts. Neural expression studies of NgR1 and NgR2 have revealed broad and overlapping, yet distinct, distribution in the mature CNS. Taken together, our studies identify NgRs as a family of receptors (or components of receptors) for myelin inhibitors and provide insights into how interactions between MAG and members of the Nogo receptor family function to coordinate myelin inhibitory responses.

  1. NeuA O-acetylesterase activity is specific for CMP-activated O-acetyl sialic acid in Streptococcus suis serotype 2.

    Science.gov (United States)

    Song, Lili; Zhou, Hui; Cai, Xuehui; Li, Chunyang; Liang, Jingnan; Jin, Cheng

    2011-07-01

    Several bacteria causing meningitis, such as Escherichia coli K1, Streptococcus suis, Neisseria meningitidis, and group B Streptococci (GBS), produce sialic acid (Neu5Ac)-containing capsular polysaccharide (CPS). Biosynthesis of the Neu5Ac-containing CPS requires CMP-Neu5Ac as substrate, which is synthesized by CMP-Neu5Ac synthetase from CTP and Neu5Ac. In E. coli or GBS, the NeuA protein encoded by the neuA gene has been known encoding a bifunctional enzyme that possesses both CMP-Neu5Ac synthetase and O-acetylesterase activity. In this report, we found that the S. suis NeuA (SsNeuA) was also a bifunctional CMP-Neu5Ac synthetase/O-acetylesterase. Biochemical analyses revealed that the SsNeuA strictly de-O-acetylated CMP-O-acetyl-Neu5Ac, whereas the E. coli NeuA (EcNeuA) preferentially de-O-acetylated CMP-O-acetyl-Neu5Ac. E. coli devoid of NeuA O-acetylesterase activity was unable to produce capsule and only CMP-Neu5Ac synthetase activity of the EcNeuA or SsNeuA could not restore its ability to produce capsule. These results suggest that the O-acetylesterase is essential for the synthesis of capsular Neu5Ac in E. coli, probably in S. suis and GBS as well. Our findings are key to understanding the biosynthesis of capsular Neu5Ac in E. coli, S. suis and GBS. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. The rainbow trout CMP-sialic acid synthetase utilises a nuclear localization signal different from that identified in the mouse enzyme.

    Science.gov (United States)

    Tiralongo, Joe; Fujita, Akiko; Sato, Chihiro; Kitajima, Ken; Lehmann, Friederike; Oschlies, Melanie; Gerardy-Schahn, Rita; Münster-Kühnel, Anja K

    2007-09-01

    The terminal sugar sialic acid (Sia) plays a pivotal role in cell-cell interaction and recognition. A prerequisite for the biosynthesis of sialoglycoconjugates is the activation of Sia to cytidine monophosphate-Sia (CMP-Sia), by CMP-Sia synthetases (CMP-Sia-syn). CMP-Sia-syn are conserved from bacteria to man, and have been found to reside in the nucleus of all vertebrate species analysed to date. We previously cloned the CMP-Sia-syn from rainbow trout (rt) and identified three clusters of basic amino acids (BC) that might act as nuclear localization signals (NLS). Here, we utilised chimeric proteins and rt CMP-Sia-syn mutants in which putative NLS sequences were deleted, to identify the nuclear transport signal. Divergent from the mouse enzyme, where the crucial NLS is part of the enzyme's active site, in the rt CMP-Sia-syn the NLS and active site are disparate. The crucial NLS in the fish enzyme is bipartite and the functionality depends on a free N-terminus. Comparative analysis of all putative rt NLS in mouse and fish cells identified a second inferior motif (rtBC5-6), which was functional only in fish cells suggesting some differences in transport mechanism or folding variabilities in fish. Moreover, based on computational analyses of putative CMP-Sia-syn from distant deuterostomian organisms it was concluded that CMP-Sia-syn nuclear localization is a relatively recent invention, originating in echinoderms. In summary, our data describing structural differences in the NLS of vertebrate CMP-Sia-syn, and the independence of Sia activation from the subcellular localization of the enzyme, provide supporting evidence that nuclear localization is linked to a second yet unknown function.

  3. Fluorescent molecularly imprinted polymers as plastic antibodies for selective labeling and imaging of hyaluronan and sialic acid on fixed and living cells.

    Science.gov (United States)

    Panagiotopoulou, Maria; Kunath, Stephanie; Medina-Rangel, Paulina Ximena; Haupt, Karsten; Tse Sum Bui, Bernadette

    2017-02-15

    Altered glycosylation levels or distribution of sialic acids (SA) or hyaluronan in animal cells are indicators of pathological conditions like infection or malignancy. We applied fluorescently-labeled molecularly imprinted polymer (MIP) particles for bioimaging of fixed and living human keratinocytes, to localize hyaluronan and sialylation sites. MIPs were prepared with the templates D-glucuronic acid (GlcA), a substructure of hyaluronan, and N-acetylneuraminic acid (NANA), the most common member of SA. Both MIPs were found to be highly selective towards their target monosaccharides, as no cross-reactivity was observed with other sugars like N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-glucose and D-galactose, present on the cell surface. The dye rhodamine and two InP/ZnS quantum dots (QDs) emitting in the green and in the red regions were used as fluorescent probes. Rhodamine-MIPGlcA and rhodamine-MIPNANA were synthesized as monodispersed 400nm sized particles and were found to bind selectively their targets located in the extracellular region, as imaged by epifluorescence and confocal microscopy. In contrast, when MIP-GlcA and MIP-NANA particles with a smaller size (125nm) were used, the MIPs being synthesized as thin shells around green and red emitting QDs respectively, it was possible to stain the intracellular and pericellular regions as well. In addition, simultaneous dual-color imaging with the two different colored QDs-MIPs was demonstrated. Importantly, the MIPs were not cytotoxic and did not affect cell viability; neither was the cells morphology affected as demonstrated by live cell imaging. These synthetic receptors could offer a new and promising imaging tool to monitor disease progression. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) mediates periarticular bone loss, but not joint destruction, in murine antigen-induced arthritis.

    Science.gov (United States)

    Shimizu, Tomohiro; Takahata, Masahiko; Kameda, Yusuke; Endo, Tsutomu; Hamano, Hiroki; Hiratsuka, Shigeto; Ota, Masahiro; Iwasaki, Norimasa

    2015-10-01

    Osteoclastogenesis requires immunoreceptor tyrosine-based activation motif signaling. Multiple immunoreceptors associated with immunoreceptor tyrosine-based activation motif adaptor proteins, including DNAX-activating protein 12 kDa (DAP12) and Fc receptor common γ (FcRγ), have been identified in osteoclast lineage cells, and some are involved in arthritis-induced bone destruction. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is an immunoreceptor that regulates osteoclast development and bone resorption in association with DAP12. Whether Siglec-15 is involved in arthritis-induced bone lesions, however, remains unknown. Here we used a murine antigen-induced arthritis model to examine the role of Siglec-15 in the development of bone lesions induced by joint inflammation. Arthritis was unilaterally induced in the knee joints of 8-week-old female wild-type (WT) and Siglec-15(-/-) mice, and the contralateral knees were used as a control. The degree of joint inflammation, and cartilage and subchondral bone destruction in Siglec-15(-/-) mice was comparable to that in WT mice, indicating that Siglec-15 is not involved in the development of arthritis and concomitant cartilage and subchondral bone destruction. On the other hand, the degree of periarticular bone loss in the proximal tibia of the arthritic knee was significantly lower in Siglec-15(-/-) mice compared to WT mice. Although osteoclast formation in the metaphysis was enhanced in both WT and Siglec-15(-/-) mice after arthritis induction, mature multinucleated osteoclast formation was impaired in Siglec-15(-/-) mice, indicating impaired osteoclast bone resorptive function in the periarticular regions of the arthritic joint in Siglec-15(-/-) mice. Confirming this result, Siglec-15(-/-) primary unfractionated bone marrow cells harvested from arthritic femurs and tibiae failed to develop into mature multinuclear osteoclasts. Our findings suggest that Siglec-15 is a therapeutic target for periarticular

  5. Sialic acid associated with αvβ3 integrin mediates HIV-1 Tat protein interaction and endothelial cell proangiogenic activation.

    Science.gov (United States)

    Chiodelli, Paola; Urbinati, Chiara; Mitola, Stefania; Tanghetti, Elena; Rusnati, Marco

    2012-06-08

    Sialic acid (NeuAc) is a major anion on endothelial cells (ECs) that regulates different biological processes including angiogenesis. NeuAc is present in the oligosaccharidic portion of integrins, receptors that interact with extracellular matrix components and growth factors regulating cell adhesion, migration, and proliferation. Tat is a cationic polypeptide that, once released by HIV-1(+) cells, accumulates in the extracellular matrix, promoting EC adhesion and proangiogenic activation by engaging α(v)β(3). By using two complementary approaches (NeuAc removal by neuraminidase or its masking by NeuAc-binding lectin from Maackia amurensis, MAA), we investigated the presence of NeuAc on endothelial α(v)β(3) and its role in Tat interaction, EC adhesion, and proangiogenic activation. α(v)β(3) immunoprecipitation with biotinylated MAA or Western blot analysis of neuraminidase-treated ECs demonstrated that NeuAc is associated with both the α(v) and the β(3) subunits. Surface plasmon resonance analysis demonstrated that the masking of α(v)β(3)-associated NeuAc by MAA prevents Tat/α(v)β(3) interaction. MAA and neuraminidase prevent α(v)β(3)-dependent EC adhesion to Tat, the consequent FAK and ERK1/2 phosphorylation, and EC proliferation, migration, and regeneration in a wound-healing assay. Finally, MAA inhibits Tat-induced neovascularization in the ex vivo human artery ring sprouting assay. The inhibitions are specific because the NeuAc-unrelated lectin from Ulex europaeus is ineffective on Tat. Also, MAA and neuraminidase affect only weakly integrin-dependent EC adhesion and proangiogenic activation by fibronectin. In conclusion, NeuAc is associated with endothelial α(v)β(3) and mediates Tat-dependent EC adhesion and proangiogenic activation. These data point to the possibility to target integrin glycosylation for the treatment of angiogenesis/AIDS-associated pathologies.

  6. Recent Development of Augmented Reality in Surgery: A Review

    Directory of Open Access Journals (Sweden)

    P. Vávra

    2017-01-01

    Full Text Available Introduction. The development augmented reality devices allow physicians to incorporate data visualization into diagnostic and treatment procedures to improve work efficiency, safety, and cost and to enhance surgical training. However, the awareness of possibilities of augmented reality is generally low. This review evaluates whether augmented reality can presently improve the results of surgical procedures. Methods. We performed a review of available literature dating from 2010 to November 2016 by searching PubMed and Scopus using the terms “augmented reality” and “surgery.” Results. The initial search yielded 808 studies. After removing duplicates and including only journal articles, a total of 417 studies were identified. By reading of abstracts, 91 relevant studies were chosen to be included. 11 references were gathered by cross-referencing. A total of 102 studies were included in this review. Conclusions. The present literature suggest an increasing interest of surgeons regarding employing augmented reality into surgery leading to improved safety and efficacy of surgical procedures. Many studies showed that the performance of newly devised augmented reality systems is comparable to traditional techniques. However, several problems need to be addressed before augmented reality is implemented into the routine practice.

  7. Adaptive multimodal interaction in mobile augmented reality: A conceptual framework

    Science.gov (United States)

    Abidin, Rimaniza Zainal; Arshad, Haslina; Shukri, Saidatul A'isyah Ahmad

    2017-10-01

    Recently, Augmented Reality (AR) is an emerging technology in many mobile applications. Mobile AR was defined as a medium for displaying information merged with the real world environment mapped with augmented reality surrounding in a single view. There are four main types of mobile augmented reality interfaces and one of them are multimodal interfaces. Multimodal interface processes two or more combined user input modes (such as speech, pen, touch, manual gesture, gaze, and head and body movements) in a coordinated manner with multimedia system output. In multimodal interface, many frameworks have been proposed to guide the designer to develop a multimodal applications including in augmented reality environment but there has been little work reviewing the framework of adaptive multimodal interface in mobile augmented reality. The main goal of this study is to propose a conceptual framework to illustrate the adaptive multimodal interface in mobile augmented reality. We reviewed several frameworks that have been proposed in the field of multimodal interfaces, adaptive interface and augmented reality. We analyzed the components in the previous frameworks and measure which can be applied in mobile devices. Our framework can be used as a guide for designers and developer to develop a mobile AR application with an adaptive multimodal interfaces.

  8. Recent Development of Augmented Reality in Surgery: A Review

    Science.gov (United States)

    Vávra, P.; Zonča, P.; Ihnát, P.; El-Gendi, A.

    2017-01-01

    Introduction The development augmented reality devices allow physicians to incorporate data visualization into diagnostic and treatment procedures to improve work efficiency, safety, and cost and to enhance surgical training. However, the awareness of possibilities of augmented reality is generally low. This review evaluates whether augmented reality can presently improve the results of surgical procedures. Methods We performed a review of available literature dating from 2010 to November 2016 by searching PubMed and Scopus using the terms “augmented reality” and “surgery.” Results. The initial search yielded 808 studies. After removing duplicates and including only journal articles, a total of 417 studies were identified. By reading of abstracts, 91 relevant studies were chosen to be included. 11 references were gathered by cross-referencing. A total of 102 studies were included in this review. Conclusions The present literature suggest an increasing interest of surgeons regarding employing augmented reality into surgery leading to improved safety and efficacy of surgical procedures. Many studies showed that the performance of newly devised augmented reality systems is comparable to traditional techniques. However, several problems need to be addressed before augmented reality is implemented into the routine practice.

  9. Recent Development of Augmented Reality in Surgery: A Review.

    Science.gov (United States)

    Vávra, P; Roman, J; Zonča, P; Ihnát, P; Němec, M; Kumar, J; Habib, N; El-Gendi, A

    2017-01-01

    The development augmented reality devices allow physicians to incorporate data visualization into diagnostic and treatment procedures to improve work efficiency, safety, and cost and to enhance surgical training. However, the awareness of possibilities of augmented reality is generally low. This review evaluates whether augmented reality can presently improve the results of surgical procedures. We performed a review of available literature dating from 2010 to November 2016 by searching PubMed and Scopus using the terms "augmented reality" and "surgery." Results. The initial search yielded 808 studies. After removing duplicates and including only journal articles, a total of 417 studies were identified. By reading of abstracts, 91 relevant studies were chosen to be included. 11 references were gathered by cross-referencing. A total of 102 studies were included in this review. The present literature suggest an increasing interest of surgeons regarding employing augmented reality into surgery leading to improved safety and efficacy of surgical procedures. Many studies showed that the performance of newly devised augmented reality systems is comparable to traditional techniques. However, several problems need to be addressed before augmented reality is implemented into the routine practice.

  10. Prototype Application of Portable Augmented Reality Technology for Enhancement of Space and Planetary Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For this project, several different augmentation techniques for locating ground articles from distance through an augmented live view were investigated....

  11. Telerobotic control with stereoscopic augmented reality

    Science.gov (United States)

    Rastogi, Anu; Milgram, Paul; Drascic, David; Grodski, Julius J.

    1996-04-01

    Teleoperation in unstructured environments is conventionally restricted to direct manual control of the robot. Under such circumstances operator performance can be affected by inadequate visual feedback from the remote site, caused by, for example, limitations in the bandwidth of the communication channel. This paper introduces ARTEMIS (Augmented Reality TEleManipulation Interface System), a new display interface for enabling local teleoperation task simulation. An important feature of the interface is that the display can be generated in the absence of a model of the remote operating site. The display consists of a stereographical model of the robot overlaid on real stereovideo images from the remote site. This stereographical robot is used to simulate manipulation with respect to objects visible in the stereovideo image, following which sequences of robot control instructions can be transmitted to the remote site. In the present system, the update rate of video images can be very low, since continuous feedback is no longer needed for direct manual control of the robot. Several features of the system are presented and its advantages discussed, together with an illustrative example of a pick-and-place task.

  12. Augmenting painted architectures for communicating cultural heritage

    Directory of Open Access Journals (Sweden)

    Alberto Sdegno

    2015-07-01

    Full Text Available The paper presents a research under development at the University of Trieste to analyze a painted architecture by Paolo Veronese and to present the results using AR systems (Augmented Reality Systems. The canvas was painted in 1573 and it is now at the Gallerie dell’Accademia Museum in Venice. The aim of the research was to transform a two-dimensional work of art in a three dimensional one, allowing all the visitors of a museum to enter the space of the representation and perceive it in a more direct way. After the geometrical analysis of the picture, we started the digital restitution of the perspective references and proceed to model the virtual scene using Boolean primitives and applying all the textures to render the scene in a very realistic way. The further step was to convert the model into a dynamic form with AR algorithms and associate it with spatial references to allow users to do a virtual experience of it.

  13. Augmented Reality Marker Hiding with Texture Deformation.

    Science.gov (United States)

    Kawai, Norihiko; Sato, Tomokazu; Nakashima, Yuta; Yokoya, Naokazu

    2017-10-01

    Augmented reality (AR) marker hiding is a technique to visually remove AR markers in a real-time video stream. A conventional approach transforms a background image with a homography matrix calculated on the basis of a camera pose and overlays the transformed image on an AR marker region in a real-time frame, assuming that the AR marker is on a planar surface. However, this approach may cause discontinuities in textures around the boundary between the marker and its surrounding area when the planar surface assumption is not satisfied. This paper proposes a method for AR marker hiding without discontinuities around texture boundaries even under nonplanar background geometry without measuring it. For doing this, our method estimates the dense motion in the marker's background by analyzing the motion of sparse feature points around it, together with a smooth motion assumption, and deforms the background image according to it. Our experiments demonstrate the effectiveness of the proposed method in various environments with different background geometries and textures.

  14. Augmented Fish Health Monitoring, 1990 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Warren, James W.

    1990-08-15

    Augmented Fish Health Monitoring Contract AI79-87BP35585 was implemented on July 20, 1987. This report briefly describes third-year work being done to meet contract requirements for fish disease surveillance at Service facilities in the Columbia River basin and for histopathological support services provided to participating state agencies. It also summarizes the health status of fish reared at participating Service hatcheries and provides a summary of case history data for calendar year 1989. Items of note included severe disease losses to infectious hematopoietic necrosis (IHN) in summer steelhead trout in Idaho, the detection of IHN virus in juvenile spring chinook salmon at hatcheries on the lower Columbia River, and improved bacterial kidney disease (BKD) detection and adult assay by enzyme-linked immunosorbent assay (ELISA) technology at the Dworshak Fish Health Center. Complete diagnostic and inspection services were provided to 13 Columbia River Basin National Fish Hatcheries. Case history data was fully documented in a computerized data base for storage and analysis and is summarized herein. 2 refs., 1 fig., 4 tabs.

  15. Escape route simulator utilizing augmented reality

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Karen Salazar Ribeiro de; Mó, Antônio Carlos de A.; Santo, André Cotelli do E.; Silva, Marcio Henrique, E-mail: karensalazar.1190@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Centro Universitário Carioca (UniCarioca), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Due to increasing demand and interest in the interaction of technology platforms and integration of different types of systems and technologies, some tools are already providing practical ways to develop integrated applications. The tools explored by this article are Unity, a platform for game development, and Vuforia, an SDK, software development kit, for augmented reality creation. The coalition proposal of these resources is to create an intuitive escape route that can be used for the evacuation of buildings or open spaces in view of imminent danger, such as radiation leakage, and that can be accessed from a target available at the institution. It has also the intention of simulating situations that involve training of personnel in order to obtain methods that allow to save financial resources, and even to avoid that those who are involved are exposed to risks unnecessarily. The simulator is expected to help design, test, and improve ways to maintain the physical integrity of the facility and provide end users with a better sense of immersion and attractiveness. (author)

  16. Spacecraft 3D Augmented Reality Mobile App

    Science.gov (United States)

    Hussey, Kevin J.; Doronila, Paul R.; Kumanchik, Brian E.; Chan, Evan G.; Ellison, Douglas J.; Boeck, Andrea; Moore, Justin M.

    2013-01-01

    The Spacecraft 3D application allows users to learn about and interact with iconic NASA missions in a new and immersive way using common mobile devices. Using Augmented Reality (AR) techniques to project 3D renditions of the mission spacecraft into real-world surroundings, users can interact with and learn about Curiosity, GRAIL, Cassini, and Voyager. Additional updates on future missions, animations, and information will be ongoing. Using a printed AR Target and camera on a mobile device, users can get up close with these robotic explorers, see how some move, and learn about these engineering feats, which are used to expand knowledge and understanding about space. The software receives input from the mobile device's camera to recognize the presence of an AR marker in the camera's field of view. It then displays a 3D rendition of the selected spacecraft in the user's physical surroundings, on the mobile device's screen, while it tracks the device's movement in relation to the physical position of the spacecraft's 3D image on the AR marker.

  17. Evaluating User Experience of Augmented Reality Eyeglasses.

    Science.gov (United States)

    Gamberini, Luciano; Orso, Valeria; Beretta, Andrea; Jacucci, Giulio; Spagnolli, Anna; Rimondi, Romina

    2015-01-01

    Augmented reality based applications have been experimented with in various contexts. Typically, the interaction is supported by handled devices, which, in specific scenarios, may hinder the interaction and spoil the experience of use, as the user is forced to hold the device and to keep her eyes on it at all times. The recent launch on the market of light-weight, unobtrusive head-mounted displays may change this circumstance. Nevertheless, investigations are needed to understand if such head-worn devices effectively outperform handheld devices in terms of comfort and pleasant experience of use. Here we present two experiments aimed at assessing the comfort of wearing a head-worn, see-through AR viewer in both a controlled and a natural setting. Besides the comfort of wearing the device, aspects related to the user experience were also investigated in the field evaluation. Our findings suggest that the head-mounted display examined is comfortable to wear regardless of the context of use. Interestingly in the field trails, participants did not express concern for the impression they would have made on other people and the experience of use was overall pleasant. Possible issues related to visual fatigue emerged.

  18. Opportunistic tangible user interfaces for augmented reality.

    Science.gov (United States)

    Henderson, Steven; Feiner, Steven

    2010-01-01

    Opportunistic Controls are a class of user interaction techniques that we have developed for augmented reality (AR) applications to support gesturing on, and receiving feedback from, otherwise unused affordances already present in the domain environment. By leveraging characteristics of these affordances to provide passive haptics that ease gesture input, Opportunistic Controls simplify gesture recognition, and provide tangible feedback to the user. In this approach, 3D widgets are tightly coupled with affordances to provide visual feedback and hints about the functionality of the control. For example, a set of buttons can be mapped to existing tactile features on domain objects. We describe examples of Opportunistic Controls that we have designed and implemented using optical marker tracking, combined with appearance-based gesture recognition. We present the results of two user studies. In the first, participants performed a simulated maintenance inspection of an aircraft engine using a set of virtual buttons implemented both as Opportunistic Controls and using simpler passive haptics. Opportunistic Controls allowed participants to complete their tasks significantly faster and were preferred over the baseline technique. In the second, participants proposed and demonstrated user interfaces incorporating Opportunistic Controls for two domains, allowing us to gain additional insights into how user interfaces featuring Opportunistic Controls might be designed.

  19. HUNT: Scavenger Hunt with Augmented Reality

    Directory of Open Access Journals (Sweden)

    Yan Lu

    2015-04-01

    Full Text Available This project shows a creative approach to the familiar scavenger hunt game. It involved the implementation of an iPhone application, HUNT, with Augmented Reality (AR capability for the users to play the game as well as an administrative website that game organizers can use to create and make available games for users to play. Using the HUNT mobile app, users will first make a selection from a list of games, and they will then be shown a list of objects that they must seek. Once the user finds a correct object and scans it with the built-in camera on the smartphone, the application will attempt to verify if it is the correct object and then display associated multi-media AR content that may include images and videos overlaid on top of real world views. HUNT not only provides entertaining activities within an environment that players can explore, but the AR contents can serve as an educational tool. The project is designed to increase user involvement by using a familiar and enjoyable game as a basis and adding an educational dimension by incorporating AR technology and engaging and interactive multimedia to provide users with facts about the objects that they have located

  20. Thrust Augmentation with Mixer/Ejector Systems

    Science.gov (United States)

    Presz, Walter M., Jr.; Reynolds, Gary; Hunter, Craig

    2002-01-01

    Older commercial aircraft often exceed FAA (Federal Aviation Administration) sideline noise regulations. The major problem is the jet noise associated with the high exhaust velocities of the low bypass ratio engines on such aircraft. Mixer/ejector exhaust systems can provide a simple means of reducing the jet noise on these aircraft by mixing cool ambient air with the high velocity engine gases before they are exhausted to ambient. This paper presents new information on thrust performance predictions, and thrust augmentation capabilities of mixer/ejectors. Results are presented from the recent development program of the patented Alternating Lobe Mixer Ejector Concept (ALMEC) suppressor system for the Gulfstream GII, GIIB and GIII aircraft. Mixer/ejector performance procedures are presented which include classical control volume analyses, compound compressible flow theory, lobed nozzle loss correlations and state of the art computational fluid dynamic predictions. The mixer/ejector thrust predictions are compared to subscale wind tunnel test model data and actual aircraft flight test measurements. The results demonstrate that a properly designed mixer/ejector noise suppressor can increase effective engine bypass ratio and generate large thrust gains at takeoff conditions with little or no thrust loss at cruise conditions. The cruise performance obtained for such noise suppressor systems is shown to be a strong function of installation effects on the aircraft.