Sialic Acids in Human Gastric Aspirates: Detection of 9-O-Lactyl- and 9-O-Acetyl-N-Acetylneuraminic Acids and a Decrease in Total Sialic Acid Concentration with Age

1993 ◽  
Vol 84 (5) ◽  
pp. 573-579 ◽  
Author(s):  
A. P. Corfield ◽  
S. A. Wagner ◽  
A. Safe ◽  
R. A. Mountford ◽  
J. R. Clamp ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Thin Layer ◽  
Acid Content ◽  
Colorimetric Assay ◽  
Sialic Acids ◽  
Gas Chromatography Mass Spectrometry ◽  
Sialic Acid Content ◽  
Acetylneuraminic Acid ◽  
Total Sialic Acid ◽  
Thin Layer Chromatographic Analysis

1. The total sialic acid content of human gastric aspirates was measured using a colorimetric assay. Care was taken to optimize the assay and to eliminate interference. 2. The sialic acid content of gastric aspirates collected under resting conditions from 77 patients with non-ulcer dyspepsia was found to decrease with age from >100 μg/ml at 25 years and younger to <20 μg/ml above 70 years of age. 3. Analysis of the sialic acids by gas chromatography, mass spectrometry and thin-layer chromatography showed the presence of N-acetylneuraminic acid and two O-acylated derivatives, 9-O-acetyl- and 9-O-lactyl-N-acetylneuraminic acids. These forms were predominantly glycosidically bound. 4. Thin-layer chromatographic analysis of individual aspirate samples showed that the O-acetylated sialic acids were present in all samples, with a maximum of 25% and a minimum of 5% of the total sialic acids.

Sialoglycoproteins and sialic acids ofPlasmodium knowlesischizont-infected erythrocytes and normal rhesus monkey erythrocytes

Parasitology ◽  
1986 ◽  
Vol 92 (3) ◽  
pp. 527-543 ◽  
Author(s):  
R. J. Howard ◽  
G. Reuter ◽  
J. W. Barnwell ◽  
R. Schauer
Keyword(s):  
Sialic Acid ◽  
Rhesus Monkey ◽  
Acid Content ◽  
Sialic Acids ◽  
Galactose Oxidase ◽  
Parasite Development ◽  
Sialic Acid Content ◽  
Acetylneuraminic Acid ◽  
Total Sialic Acid ◽  
Significant Difference

SUMMARYThe effects of malaria infection on RBC sialic acids and sialoglycoproteins were studied with asexual blood-stage infections ofPlasmodium knowlesiin rhesus monkeys. Glycoprotein radio-isotope labelling methods were used to compare the sialoglycoproteins of normal RBC andP. knowlesischizont-infected RBC (SI-RBC). Tritiation of glycoproteins from SI-RBC with the standard sialidase + galactose oxidase/NaB3H4method or standard periodate/NaB3H4method was significantly decreased when compared to normal RBC. However, tritium uptake into glycoproteins was normal when SI-RBC were treated with 5-fold higher concentrations of both enzymes in the first labelling method, or with a 5-fold increase in the molar ratio of periodate to sialic acid in the second method. The mobility of tritiated host cell glycoproteins on SDS–polyacrylamide gels was identical for SI-RBC and normal RBC. New bands, possibly glycoproteins, of 230, 160, 90, 52, and 30 kDa were detected after labelling SI-RBC by the modified periodate/NaB3H4method. Sialic acid analysis of normal rhesus monkey RBC (62μg/1010RBC) revealed that 46% of the total sialic acid wasN-glycolylneuraminic acid, 33% wasN-acetyl-9-O-acetylneuraminic acid, and the remainderN-acetylneuraminic acid. SI-RBC collected either directly from infected monkeys or afterin vitroculture of ring-infected RBC in horse serum, had increased total sialic acid (126 or 115μg/1010RBC, respectively). The sialic acid content of infected RBC must increase during parasite development since RBC infected with ring-stageP. knowlesihad the same content as normal RBC. There was no significant difference in the ratio of the three sialic acids of SI-RBC and normal RBC. In contrast, the uninfected RBC from infected blood of different monkeys showed marked variation in sialic acid composition and generally had a lower sialic acid content than normal RBC.

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.

scholarly journals Investigations on the oligosaccharide units of an A myeloma globulin

1968 ◽  
Vol 107 (3) ◽  
pp. 341-352 ◽  
Author(s):  
G. Dawson ◽  
J. R. Clamp
Keyword(s):  
Sialic Acid ◽  
Electrophoretic Mobility ◽  
Acid Content ◽  
Carbohydrate Content ◽  
Glycosidic Linkage ◽  
Core Oligosaccharide ◽  
Sialic Acid Content ◽  
Acetylneuraminic Acid ◽  
The Core ◽  
Polypeptide Chains

The carbohydrate content of an A myeloma globulin was investigated. The carbohydrate content was found to be unchanged when the protein was isolated from the patient over a period of 18 months. The various polymeric forms of the protein contained similar proportions of carbohydrate. The A myeloma globulin contained approx. 2 residues of 6-deoxy-l-galactose (l-fucose), 14–15 of d-mannose, 12–13 of d-galactose, 12–13 of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine), 6 of 2-acetamido-2-deoxy-d-galactose (N-acetyl-d-galactosamine) and 5 of N-acetylneuraminic acid (sialic acid), and these were distributed between six oligosaccharide units all of which were present on the heavy polypeptide chains. The oligosaccharide units showed two kinds of heterogeneity, which have been termed central and peripheral. Central heterogeneity was shown by the presence of three completely different core units, which had the following compositions: (1) 3 residues of d-galactose and 3 of 2-acetamido-2-deoxy-d-galactose, joined to protein by an O-glycosidic linkage between acetamidohexose and serine; (2) 3 residues of d-mannose, 2 of d-galactose and 3 of 2-acetamido-2-deoxy-d-glucose, joined to protein by an N-glycosidic linkage between acetamidohexose and aspartic acid; (3) 4 residues of d-mannose and 3 of 2-acetamido-2-deoxy-d-glucose with a linkage similar to that in (2). The core oligosaccharide units showed peripheral heterogeneity in the attachment of 6-deoxy-l-galactose, 2-acetamido-2-deoxy-d-glucose and N-acetylneuraminic acid. Tentative structures are proposed for these various types of oligosaccharide unit. Glycopeptides were isolated in which the sialic acid content exceeded that of d-galactose. Explanations are given for the electrophoretic mobility and staining characteristics of the various glycopeptides.

Removal of O-acetylated sialic acids from rat colonic epithelial glycoproteins by cell-free extracts of rat faeces

1983 ◽  
Vol 61 (8) ◽  
pp. 868-874 ◽  
Author(s):  
H. Poon ◽  
P. E. Reid ◽  
C. W. Ramey ◽  
W. L. Dunn ◽  
M. G. Clay
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Minimal Medium ◽  
Wistar Rat ◽  
Sialic Acids ◽  
Side Chain ◽  
Sialic Acid Content ◽  
Vibrio Cholera ◽  
Sterile Cell

Sterile, cell-free, extracts of freshly defaecated Wistar rat faeces in a pH 7.0 "minimal medium" contain neuraminidase(s), capable of removing sialic acids both with and without side-chain substituents from bovine submandibular mucin and rat colonic epithelial glycoproteins, and an esterase which removes O-acetyl substituents from the side chain of sialic acid residues. Studies of the removal of sialic acids from bovine submandibular mucin and rat colonic epithelial glycoproteins indicated that (i) the faecal enzymes removed a greater proportion of the sialic acid of both the de-O-acetylated and native glycoproteins than was removed with Vibrio cholera neuraminidase, (ii) sialic acids were removed more rapidly from de-O-acetylated glycoproteins, and (iii) the resistance to removal of sialic acids was apparently dependent at least in part upon the O-acetyl sialic acid content of the substrate.

Sialic acid analysis and tritium-labelling of sialoglycoproteins of mouse erythrocytes infected withPlasmodium berghei

Parasitology ◽  
1986 ◽  
Vol 92 (3) ◽  
pp. 545-557 ◽  
Author(s):  
R. J. Howard ◽  
D. C. Seeley ◽  
Vivien Kao ◽  
Margreat Wember ◽  
R. Schauer
Keyword(s):  
Sialic Acid ◽  
Sialic Acids ◽  
Mouse Serum ◽  
Sialic Acid Content ◽  
Infected Blood ◽  
Acetylneuraminic Acid ◽  
Molar Ratios ◽  
Infected Cells ◽  
Quantitative Changes ◽  
Qualitative Changes

SUMMARYSchizont-infected red blood cells (SI-RBC) fromPlasmodium berghei-infected mice contain between 2 and 10 times as much sialic acid as uninfected RBC from the same blood (99–550 μg/1010RBC versus 33–65 μg/1010RBC). Total RBC samples from infected animals containing up to 63% ring- and trophozoite-infected cells had identical sialic acid contents to purified RBC samples (of < 3% parasitaemia) from the same blood (52–64 μg/1010RBC). We conclude that RBC containing immature parasites have the same sialic acid content as uninfected RBC from infected blood and that total cellular sialic acid increases during maturation to the schizont stage. Uninfected RBC from infected blood had 25–50% as much sialic acid as normal mouse RBC (33–65 μg/1010RBC versus 126 μg/1010RBC). There were no qualitative changes in RBC sialic acids, all RBC samples having 60–70%N-acetyl neuraminic acid, 30–40%N-acetyl-9-O-acetylneuraminic acid and 5–10%N-gly colylneuraminic acid. The quantitative changes we observed during infection must reflect changes in murine sialoglycoconjugates, as we have shown elsewhere that Plasmodia do not synthesize or contain sialic acids. Since the sialic acid composition of mouse serum glycoconjugates is quite different to that of the RBC fractions studied here, the quantitative data suggest that part of the sialic acids of the uninfected RBC has been transferred to SI-RBC. With higher molar ratios of periodate to substrate than generally used, we were able to radio-isotopically label normal murine sialoglycoproteins on SI-RBC and purified uninfected RBC from infected blood by the periodate/NaB3H4method. Several new proteins were then tritiated with SI-RBC but these proteins may be intracellular and could even lack sialie acid.

Sialic Acid Content of Red Blood Cells from Protein-Calorie Malnourished Children and During Recovery, and from Normal Children and Adults

1973 ◽  
Vol 51 (11) ◽  
pp. 853-858
Author(s):  
C. Contreras ◽  
F. E. Viteri
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Recovery Period ◽  
Serum Vitamin ◽  
Sialic Acids ◽  
Red Cells ◽  
Control Group ◽  
Red Cell ◽  
Normal Children ◽  
Sialic Acid Content

Sialic acids were measured in the red cells of two groups of subjects. One group consisted of 12 children with severe protein-calorie malnutrition (P.C.M.); six of them were followed longitudinally throughout the recovery period. The control group included 28 normal children and 11 normal adults. All subjects were studied hematologically and the sialic acid content of the red cells was determined in three layers of erythrocytes, separated according to their density by ultracentrifugation. The results indicate that there are no alterations in the content of sialic acids in the red cells of children with severe P.C.M. Furthermore, they show that the sialic acid content of the red cell is not influenced by various levels of red cell folates nor by differences in the concentration of serum proteins, serum iron, percentage saturation of transferrin, serum folates, or serum vitamin B12.

SIALIC ACID CONTENT OF NORMAL RAT LIVER AND OF DAB-INDUCED HEPATOMATA

1964 ◽  
Vol 42 (1) ◽  
pp. 25-31 ◽  
Author(s):  
H. Kalant ◽  
Wilhelmina Mons ◽  
Marta Guttman
Keyword(s):  
Sialic Acid ◽  
Rat Liver ◽  
Acid Content ◽  
Thiobarbituric Acid ◽  
Normal Liver ◽  
Fresh Tissue ◽  
Sialic Acid Content ◽  
Tissue Samples ◽  
Total Sialic Acid ◽  
Normal Rat

Total sialic acid content of rat livers and tumors was determined by acid hydrolysis of tissue samples, isolation on Dowex-2 columns, and reaction with thiobarbituric acid. Normal rat liver was found to contain 465 μg of neuraminic acid per g of fresh tissue. In rats bearing hepatomata induced by the feeding of p-dimethylaminoazobenzene, the tumors contained an average of 1162 μg/g, while the surrounding liver contained 587 μg/g. Treatment of tissue sections with purified neuraminidase liberated only 27–28% of the sialic acid from liver tissue, but 49% of that in the hepatomata. Paper chromatographic analysis indicated a difference between normal liver and hepatomata with respect to the types of sialic acid present.

Relationship Between Sputum Viscosity and Total Sialic Acid Content

1968 ◽  
Vol 57 (5) ◽  
pp. 824-827 ◽  
Author(s):  
R. Munies ◽  
T.C. Grubb ◽  
R.E. Caliari
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Sialic Acid Content ◽  
Total Sialic Acid

scholarly journals Protection through L-Carnitine on Tissue Oxidant Status and Sialic Acid Content in Tilmicosin-Induced Alterations in BALB/c Mice

2007 ◽  
Vol 76 (2) ◽  
pp. 203-207 ◽  
Author(s):  
A. Kart ◽  
M. Karapehlivan ◽  
K. Yapar ◽  
M. Citil ◽  
A. Akpinar
Keyword(s):  
Sialic Acid ◽  
Acid Content ◽  
Control Group ◽  
Sialic Acid Content ◽  
Tissue Samples ◽  
Total Sialic Acid ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2

The macrolide antibiotic tilmicosin is known to induce cardiotoxic effect when administered at large doses. In this work, the effects of tilmicosin were evaluated with respect to alterations in total sialic acid, malondialdehyde and glutathione content of the heart, liver, kidney and lung tissues after single subcutaneous injection of 75 mg/kg tilmicosin with or without L-carnitine (500 mg/kg for 5 days daily via s.c. route) in BALB/c mice. L-carnitine is a co-factor serving in the mitochondrial β-oxidation of long chain fatty acids, and it was reported to be protective in several types of toxicity cases probably via multi-factorial mechanisms. Twenty eight mice were divided into 4 groups including group 1 (control), group 2 (L-carnitine), group 3 (tilmicosin) and group 4 (tilmicosin plus L-carnitine). Following the administration of treatments, tissue samples were collected, and the samples were assayed for malondialdehyde, glutathione and total sialic acid content. Mice receiving tilmicosin treatment alone had significantly higher malondialdehyde and total sialic acid concentrations (except for MDA of lungs) but lower glutathione concentration in selected tissues compared to those of the control, group 2 (Carnitine only) and group 4 (L-carnitine plus tilmicosin) (p < 0.05). However, no significant difference was found associated with the assayed indicators between the control and mice treated with L-carnitine plus tilmicosin. These results suggest that tilmicosin may cause oxidative stress in the heart, liver, lung and kidneys, but the adverse effects could be attenuated by L-carnitine administration.

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