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G C Tsay

Publications and source records attributed to G C Tsay.

15 recordsLinked to original sources
PubMed1993

Process-scale purification of immunoglobulin M concentrate.

An IgM concentrate was purified from Cohn fraction III. Efficiency of euglobin precipitation was shown to be controlled by pH and ionic strength. Prekallikrein activator activity in the product was insignificant. Overall yield from the octanoic acid supernate and purity of the concentrate were 66 +/- 8 (n = 16) and 50 +/- 5% (n = 16), respectively. Solvent-detergent treatment to inactivate lipid-enveloped viruses was demonstrated and implemented into the process. Process studies to control residual virucidal agents and C4a generating activity are presented.

Chemical Fractionation↗
PubMed1984

Preparation and characterization of a nontoxic polysaccharide-protein conjugate that induces active immunity and passively protective antibody against Pseudomonas aeruginosa immunotype 1 in mice.

Acid treatment of Pseudomonas aeruginosa immunotype 1 lipopolysaccharide generated a low-molecular-weight polysaccharide fraction that was detectable in agar gel immunodiffusion but did not induce antibodies or resistance to infection in mice. The polysaccharide was treated with periodate to generate additional aldehyde groups. Oxidized polysaccharide was covalently coupled by reductive amination to 1,4-diaminobutyl-derivatized bovine serum albumin. Physical properties of the conjugate were characterized by gel filtration and high-pressure liquid chromatography. The gelation activity of the conjugate in the Limulus amoebocyte lysate assay was 4,000-fold less than native lipopolysaccharide by weight. Mice immunized with the conjugate resisted challenge with P. aeruginosa immunotype 1 that killed 90% of mice immunized with saline. Immunization with the conjugate vaccine induced humoral immunoglobulin G that passively protected normal and burned mice. These results indicate that conjugation of nonimmunogenic polysaccharide antigen of P. aeruginosa restores immunogenicity similar to that of native lipopolysaccharide without restoring endotoxicity inherent in lipopolysaccharide.

Animals↗
PubMed1976

Structure of the accumulating oligosaccharide in fucosidosis.

Two water-soluble complex carbohydrate storage products were isolated from tissues and urine of patients with an inherited deficiency of lysosomal alpha-L-fucosidase (fucosidosis). The major component was an oligosaccharide of approximate molecular weight 1700, indicating that it was a dekasaccharide. From a combination of sequential digestion with purified exo-glycosidases, periodate oxidation and permethylation in conjunction with gas-liquid chromatography mass spectrometric analysis, the structure was found to be: Fuc(alpha 1 leads to 2)Gal-(beta 1 leads to 4) GlcNAc (beta1 leads to 2)Man [Fuc(alpha1 leads to 2) Gal (beta1 leads to 4) GlcNAc(beta1 leads to 2) Man] (alpha 1 leads to 3/6) Man (beta1 leads to 4) GlcNAc, although there was some evidence for heterogeneity at the mannose branchpoint. This material is structurally related to the stored oligosaccharides in patients with inherited deficiencies of beta-galactosidase (G M1-gangliosidosis) and N-acetyl-beta-hexosaminidase (G M2-gangliosidosis). A dissaccharide with the probable structure Fuc(alpha1 leads to 6)GlcNAc was found in lesser amounts in tissues; both are believed to be derived from the impaired catabolism of large numbers of different glycoproteins.

Acetylglucosamine↗
PubMed1976

Fucosidosis.

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Adult↗
PubMed1975

Structure of the glycopeptide storage material in GM 1 gangliosidosis. Sequence determination with specific endo- and exoglycosidases.

1. An endo-beta-galactosidase from Escherichia freundii, specific for the hydrolysis of desulfated keratan sulfate, quantitatively liberated a trisaccharide (Gal-GlcNAc-Gal) from a glycopeptide (Mr 1800) isolated from the liver of a patient with GM 1 (generalized) gangliosidosis. 2. The remaining glycopeptide was susceptible to sequential digestion with purified beta-N-acetylhexosaminidase and exo-beta-galactosidase from Jack Bean meal. 3. These and other studies established the structure of the stored glycopeptide to be:(see article) which probably represents the desulfated linkage region of skeletal keratan sulfate.

Amino Acids↗
PubMed1975

Glycopeptide storage in skin fibroblasts cultured from a patient with alpha-mannosidase deficiency.

Patients with mannosidosis, an inherited deficiency of lysosomal alpha-mannosidase, accumulate large amounts of mannose-rich oligosaccharides (the "core" of the carbohydrate units of many glocoproteins) in brain and liver and excrete these partial degradation products in their urine. A profound alpha-mannosidase deficiency was demonstrated in fibroblasts cultured from a skin biopsy obtained from a child with mannosidosis. Further, abnormal glycopeptides rich in mannose and similar to oligosaccharides found in the patient's urine were isolated from fibroblast extracts by a variety of chromatographic procedures and by virtue of their binding to a concanavalin A-Sepharose 4B affinity column. This storage material contained mannose, N-acetylglucosamine, and asparagine in the ratio 3 : 1 : 1 together with a few toher amino acids and had a molecular weight of approximately 1,100. There was no evidence for excretion of storage material by mannosidosis fibroblasts or for any abnormality in cell surface glycoprotein composition. The glycopeptide nature of the storage material isolated from cultured skin fibroblasts may be attributed to the low level of N-aspartyl-beta-glucosamindase (EC 3.5.1.-) activity in these cells.

Asparaginase↗
PubMedDate not supplied

Immunoglobulin G: potentiation of tobramycin and azlocillin in the treatment of Pseudomonas aeruginosa sepsis in neutropenic mice and neutralization of exotoxin A in vivo.

Mice with cyclophosphamide-induced neutropenia were challenged with four immunotypes of Pseudomonas aeruginosa by contamination of a small dorsal surface wound. The infections were lethal; 100% of control animals (n = 80) treated only with albumin died. Administration of an immunoglobulin G intravenous preparation (IGIV) and/or therapy with tobramycin or azlocillin was begun 16 hr after challenge. Mortality among mice (n = 120) treated only with an antibiotic was 75.0%, while that among mice (n = 80) treated only with IGIV was 78.8%. Combination therapy with IGIV and an antibiotic (n = 120) resulted in mortality of 38.3%. The protection afforded by IGIV may have resulted in part from neutralization of exotoxin A, as mice treated with IGIV before challenge with exotoxin A were subject to lower mortality and had lower levels of serum aspartate and alanine aminotransferases than controls.

ADP Ribose Transferases↗