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Biomedical subjects

C C Wan

Publications and source records attributed to C C Wan.

23 records · Page 2Linked to original sources
PubMed1976

beta-Mannosidase from the mushroom Polyporus sulfureus.

beta-D-Mannosidase (EC 3.2.1.25), a useful tool for the structural studies of heterosaccharide chains, has been isolated in a highly purified form from the fruiting bodies of the mushroom Polyporus sulfureus. This mushroom is unique among reported sources of this enzyme in that it has the advantage of being almost free of alpha-mannosidase activity. The purification procedure involves ammonium sulfate fractionation followed by Sephadex G-100 filtration and chromatography on columns of DEAE-cellulose and hydroxylapatite. The final enzyme preparation gives essentially a single band on disc gel electrophoresis. The purified enzyme liberates the beta-D-mannopyranosyl unit from various natural substrates such as the core glycopeptide, Man(GlcNAc)2-Asn isolated from ovalbumin, from Taka-amylase A, and from human alpha1-acid glycoprotein. It also hydrolyzes (Man)2-GlcNAc from the urine of an alpha-mannosidosis patient, 1,4-D-mannobiose and mannotriose isolated from ivory nut mannan, 4-O-beta-D-mannopyranosyl-L-rhamnose, 6-O-beta-D-mannopyranosyl-D-galactose and 4-O-beta-D-mannopyranosyl-N-acetylglucosamine. The molecular weight of this enzyme is estimated to be about 64,000 by gel filtration. For p-nitrophenyl-beta-D-mannopyranoside, the pH optimum is between 2.4 and 3.4 and the Km is 1.6 mM.

Basidiomycota↗
PubMedDate not supplied

Multivariate risks among extremely premature infants.

This study was designed to identify risk factors for mortality and morbidity of extremely premature infants born in the surfactant era. The study cohort included 194 infants born at < 29 weeks' gestation at one regional tertiary center between 1983 and 1986. Forty-one infants died. Blinded neurodevelopmental assessments were performed on 149 of 153 (97%) survivors at a mean age of 52 months. Thirty-one (21%) survivors had major impairments: 15 had mental retardation, 8 had multiple impairments, 7 had cerebral palsy, and 1 was blind. Logistic regression analysis identifies five significant risk factors for mortality: grade III or IV intraventricular hemorrhage, birth weight < 800 gm, 5-minute Apgar score < or = 3, male sex, and absence of surfactant therapy. Significant risk factors for any major impairment included sepsis (relative risks [RR] = 6.4), male sex (RR = 3.1), and nonwhite race (RR = 2.8). Hydrocephalus requiring shunting was a significant risk factor for cerebral palsy (RR = 16.4) and neonatal retardation (RR = 16.0). Nonwhite race (RR = 7.3), sepsis (RR = 6.8), and male sex (RR = 3.7) also were significant risk factors for mental retardation. Confirmation of these risk factors should facilitate development of targeted interventions for optimizing long-term outcome.

Blindness↗