Biomedical subjects

Y John Wang

Publications and source records attributed to Y John Wang.

4 recordsLinked to original sources

PubMed2005

A 2-year follow-up study of alcohol consumption and risk of dementia.

BACKGROUND: This report focused on investigating the relationship between alcohol consumption and dementia in elderly people through prospective studies. METHODS: We conducted a 2-year follow-up study of elderly people from six communities in Chongqing, China. Dementia was detected using the Mini-Mental State Examination (MMSE) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). The relationship between alcohol consumption and dementia was investigated using multiple logistic regression models, adjusting for the potential confounders age, sex, educational level and cigarette smoking. RESULTS: Light-to-moderate drinking was associated with a significantly lower risk of dementia compared with non-drinking. Excessive drinking was related to a higher risk of dementia. The effect of light-to-moderate drinking seemed most prominent among vascular dementia, 0.63 (0.55-0.72) for Alzheimer's disease, 0.31 (0.19-0.51) for vascular dementia and 0.45 (0.12-1.69) for other dementia. In a model adjusting for confounding variables, a light-to-moderate intake of beer was associated with a significantly higher risk of dementia than a non-drinker of beer. For wine, a significantly lower risk of dementia existed for a light-to-moderate drinker. CONCLUSIONS: Light-to-moderate drinking was associated with a significantly lower risk of dementia compared with a non-drinker.

Aged↗

PubMed2003

Coagulation factor VIII: structure and stability.

Factor VIII (FVIII), a coagulation factor in the blood, is one of the most complex proteins known today. To facilitate the rapid development of a more convenient and safer FVIII product and to improve the quality of life for hemophilia patients, this short article reviews the recent investigations on the structure, activity, and more importantly, stability of FVIII.

Animals↗

PubMed2002

Peroxide formation in polysorbate 80 and protein stability.

Nonionic surfactants are widely used in the development of protein pharmaceuticals. However, the low level of residual peroxides in surfactants can potentially affect the stability of oxidation-sensitive proteins. In this report, we examined the peroxide formation in polysorbate 80 under a variety of storage conditions and tested the potential of peroxides in polysorbate 80 to oxidize a model protein, IL-2 mutein. For the first time, we demonstrated that peroxides can be easily generated in neat polysorbate 80 in the presence of air during incubation at elevated temperatures. Polysorbate 80 in aqueous solution exhibited a faster rate of peroxide formation and a greater amount of peroxides during incubation, which is further promoted/catalyzed by light. Peroxide formation can be greatly inhibited by preventing any contact with air/oxygen during storage. IL-2 mutein can be easily oxidized both in liquid and solid states. A lower level of peroxides in polysorbate 80 did not change the rate of IL-2 mutein oxidation in liquid state but significantly accelerated its oxidation in solid state under air. A higher level of peroxides in polysorbate 80 caused a significant increase in IL-2 mutein oxidation both in liquid and solid states, and glutathione can significantly inhibit the peroxide-induced oxidation of IL-2 mutein in a lyophilized formulation. In addition, a higher level of peroxides in polysorbate 80 caused immediate IL-2 mutein oxidation during annealing in lyophilization, suggesting that implementation of an annealing step needs to be carefully evaluated in the development of a lyophilization process for oxidation-sensitive proteins in the presence of polysorbate.

Air↗

PubMedDate not supplied

Oxidation of protein by vaporized sanitizing agents.

For the first time, it has been demonstrated that a protein product can be oxidized readily by certain sanitizing agents through vapor transfer not only in a closed system but also in an open environment. The effect of several sanitizing agents on the oxidation of a model protein, IL-2 mutein, was investigated under different processing conditions. Reversed phase-high performance liquid chromatography (RP-HPLC) was used to separate and quantitate both intact and oxidized IL-2 mutein. It was found that peracetic acid or NaOCl oxidizes IL-2 mutein instantaneously, while H2O2-induced oxidation of IL-2 mutein is much slower in solution. The amount of protein oxidation product is proportional to the duration of sample exposure and the type and concentration of the sanitizing agent. In addition, sanitizing agents can accelerate protein oxidation during lyophilization, and the residual amount can promote oxidation of the lyophilized product during storage. These results strongly suggest that the sanitization process needs to be properly controlled and closely monitored during manufacturing of drug products that are sensitive to oxidation.

Chromatography, High Pressure Liquid↗