SIALIC ACID AND SIALIDASE ACTIVITY IN HUMAN ENDOMETRIAL TISSUE, UTERINE FLUID AND PLASMA UNDER DIFFERENT CONDITIONS OF UTERINE DYSFUNCTION

1976 ◽  
Vol 81 (3) ◽  
pp. 574-579 ◽  
Author(s):  
S. Ganguly ◽  
D. Sarkar ◽  
J. J. Ghosh
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Antagonistic Effect ◽  
Endometrial Tissue ◽  
Sialic Acid Content ◽  
Sialidase Activity ◽  
Uterine Fluid

ABSTRACT Sialic acid content in endometrial tissue and sialidase activity in the endometrium, uterine fluid and plasma has been measured in normal and in conditions of uterine dysfunctions. It has been observed that an antagonistic effect exists between endometrial sialidase and sialic acid content, but in all the cases of uterine dysfunctions, the sialidase activity in uterine fluid and plasma decreases, whereas it increases during pregnancy.

scholarly journals Sialic Acid and Sialidase Activity in Acute Stroke

2008 ◽  
Vol 25 (3) ◽  
pp. 167-173 ◽  
Author(s):  
L. Nanetti ◽  
A. Vignini ◽  
F. Raffaelli ◽  
R. Taffi ◽  
M. Silvestrini ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Stroke Severity ◽  
Sialic Acid Content ◽  
Sialidase Activity ◽  
Disease Mechanisms ◽  
Study Population ◽  
Cerebral Ischemic ◽  
Cerebral Ischemic Damage

Stroke is a heterogeneous syndrome caused by multiple disease mechanisms, resulting in a disruption of cerebral blood flow with subsequent tissue damage. It is well known that erythrocytes have a large amount of sialic acid and could represent a model to investigate changes occurring in a pathology like stroke. The aim of this study was to investigate a possible relationship among erythrocyte membrane, plasma and sialic acid content. The possible impact of the sialic acid content and the activity of sialidase on stroke severity was also evaluated.The study population consisted of 54 patients with a first stroke and of 53 age-and sex matched healthy volunteers.The total bound sialic acid was substantially decreased in patients. There was a significant correlation between the sialidase activity values and the severity of the neurological deficit defined by the National Institute of Health Stroke Scale.This study shows that low sialic acid erythrocyte concentrations with contemporary high sialic acid plasma levels and elevated sialidase activity can be considered as markers of ischemic stroke. Further investigations are needed to clarify the possible role of these biochemical changes in producing and sustaining cerebral ischemic damage.

The Human Platelet Glycome and Its Variations Among Healthy Volunteers and Storage

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2300-2300
Author(s):  
Renata Grozovsky ◽  
Qiyong Peter Liu ◽  
Andrew Hanneman ◽  
David J. Ashline ◽  
Hailong Zhang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Sialic Acid ◽  
Acid Content ◽  
Healthy Subjects ◽  
Sialic Acid Content ◽  
Platelet Surface ◽  
Standard Methods ◽  
Sialidase Activity ◽  
Platelet Storage ◽  
Terminal Galactose

Abstract Platelets have the shortest shelf-life of all major blood components and are the most difficult to store complicating platelet transfusion practices. Transfused fresh radiolabeled autologous platelets differ significantly in recovery and survival among healthy subjects, however the cause of the inter-individual differences remains unclear. We demonstrated that the loss of sialic acid from the surfaces of cold-stored and transfused platelets promotes their clearance by Ashwell Morell receptors. The loss of platelet surface sialic acid correlates with increases in surface sialidase activity during platelet storage. Here we investigated whether fresh platelets from individual donors exhibit differences in surface sialidase expression and glycan exposure and sialic acid content changes with storage. Methods Platelets were isolated by standard methods from the venous blood of healthy volunteers or from standard platelet concentrates (PCs) and analyzed by flow cytometry for surface β-galactose using FITC-conjugated E. cristagalli lectin (ECL). Platelet surface sialidase expression was measured by flow cytometry using antibodies to sialidases Neu1 and Neu3. Sialidase activities were assayed using standard methods, Platelet uptake by hepatocytes was measured by using the human hepatoma cell line HepG2. To further elucidate these issues in a structural biology context we performed baseline study of the N- and O-linked glycans and glycosphingolipids (GSLs) in platelets, and any structural changes observed during storage, by employing HPLC, LC-MS/(MS), and sequential mass spectrometry (MSn) approaches. Results We found that terminal galactose on freshly-isolated platelet glycoproteins varies considerably among healthy subjects: Seven of ten individuals had low levels of exposed galactose (15.3 ± 4.1, MFI) and three subjects exhibited significantly higher levels of terminal galactose as detected by flow cytometry using lectins. Reduced sialic acid content correlated with increased surface sialidase activity and expression. Platelets with high terminal galactose were ingested with a higher rate by HepG2 cells, i.e via Ashwell Morell receptors. Importantly, individuals with low sialic acid levels correlate with low platelet counts at steady state. Structural analysis revlealed that fresh platelet N-glycan pools include a significant amount of high-mannose (Man5-Man9) and asialo complex glycans, however, are dominated by a diverse range of complex sialylated structures with two to four antennae, up to four NeuAcs, and include antennary fucosylation, and five or more lactosamine extensions. The O-linked fractions are comprised of core-1 and core-2 glycans having zero, one, or two NeuAc residues. A significant decrease in sialylation during conventional platelet storage at room temperature was confirmed at the level of individual O-glycan structures. Quantitative analysis of the more structurally complex N-glycan pools is ongoing. Conclusion Our results show that fresh platelets from healthy individuals vary in surface sialidase activity and sialic acid content and exhibit a high complexity in glycan structures. Collectively we propose that individual platelet counts may be dependent on surface sialic acid content and that the surface sialic acid could represent a factor that affects the recovery and survival of transfused platelets. Disclosures: No relevant conflicts of interest to declare.

129: Sialic Acid Content of Urinary TAMM-Horsfall Protein is Reduced in Interstitial Cystitis Patients

2007 ◽  
Vol 177 (4S) ◽  
pp. 44-45
Author(s):  
C. Lowell Parsons ◽  
Mahadevan Rajasekaran ◽  
Marianne Chenoweth ◽  
Paul Stein
Keyword(s):  
Sialic Acid ◽  
Interstitial Cystitis ◽  
Acid Content ◽  
Sialic Acid Content

scholarly journals Differences in Sialic Acid Content of Human Interferons

1978 ◽  
Vol 41 (1) ◽  
pp. 175-178 ◽  
Author(s):  
J. Morser ◽  
J. P. Kabayo ◽  
D. W. Hutchinson
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Sialic Acid Content

scholarly journals Infection with Listeria monocytogenes impairs sialic acid addition to host cell glycoproteins.

1994 ◽  
Vol 180 (6) ◽  
pp. 2137-2145 ◽  
Author(s):  
M S Villanueva ◽  
C J Beckers ◽  
E G Pamer
Keyword(s):  
Listeria Monocytogenes ◽  
Sialic Acid ◽  
Host Cell ◽  
Mhc Class I ◽  
Acid Content ◽  
Class I ◽  
Sialic Acid Content ◽  
Infected Cells ◽  
The Impact ◽  
Glycosylation Defect

Listeria monocytogenes is a facultative intracellular bacterium that causes severe disease in neonates and immunocompromised adults. Although entry, multiplication, and locomotion of Listeria in the cytosol of infected cells are well described, the impact of such infection on the host cell is unknown. In this report, we investigate the effect of L. monocytogenes infection on MHC class I synthesis, processing, and intracellular trafficking. We show that L. monocytogenes infection interferes with normal processing of N-linked oligosaccharides on the major histocompatibility complex (MHC) class I heavy chain molecule, H-2Kd, resulting in a reduced sialic acid content. The glycosylation defect is more pronounced as the infection progresses and results from interference with the addition of sialic acid rather than its removal by a neuraminidase. The effect is found in two different cell lines and is not limited to MHC class I molecules since CD45, a surface glycoprotein, and LGP120, a lysosomal glycoprotein, are similarly affected by L. monocytogenes infection. The glycosylation defect is specific for infection by L. monocytogenes since neither Trypanosoma cruzi nor Yersinia enterocolitica, two other intracellular pathogens, reproduces the effect. The resultant hyposialylation of H-2Kd does not impair its surface expression in infected cells. Diminished sialic acid content of surface glycoproteins may enhance host-defense by increasing susceptibility to lysis and promoting clearance of Listeria-infected cells.

scholarly journals Erythrocyte Sialic Acid Content during Aging in Humans: Correlation with Markers of Oxidative Stress

2012 ◽  
Vol 32 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Mohammad Murtaza Mehdi ◽  
Prabhakar Singh ◽  
Syed Ibrahim Rizvi
Keyword(s):  
Oxidative Stress ◽  
Sialic Acid ◽  
Erythrocyte Membrane ◽  
Acid Content ◽  
Lipid Hydroperoxide ◽  
Plasma Lipid ◽  
Sialic Acids ◽  
Sialic Acid Content ◽  
Total Antioxidant ◽  
The Relationship

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.

Tamm-Horsfall glycoprotein: role in inhibition and promotion of renal calcium oxalate stone formation studied with Fourier-transform infrared spectroscopy

1994 ◽  
Vol 40 (9) ◽  
pp. 1739-1743 ◽  
Author(s):  
R Knörle ◽  
P Schnierle ◽  
A Koch ◽  
N P Buchholz ◽  
F Hering ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Sialic Acid ◽  
Calcium Oxalate ◽  
Fourier Transform Infrared Spectroscopy ◽  
Acid Content ◽  
Stone Formation ◽  
Fourier Transform Infrared ◽  
Sialic Acid Content ◽  
Stone Formers

Abstract Tamm-Horsfall glycoprotein (THP) from healthy probands inhibits the precipitation of calcium oxalate, whereas THP from individuals who repeatedly develop calcium oxalate stones has no effect or even promotes precipitation. Using Fourier-transform infrared spectroscopy, we found a structural differentiation between these functionally different THPs: a decisive difference in sialic acid content. Quantitative analysis for sialic acid showed the same results. THP from healthy probands had a high sialic acid content (51 +/- 9 g/kg), whereas THP from recurrent stone formers had a decreased sialic acid content (21 +/- 4 g/kg). This explains the dual role of THP in the precipitation of calcium oxalate and the formation of renal stones and shows the importance of glycosylation in the function of this glycoprotein.

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