Direct quantitative analysis of the natural moisturizing factor (NMF) in the stratum corneum by direct analysis in real time mass spectrometry (DART-MS)

Analyzing the natural moisturizing factor (NMF) in the stratum corneum (SC), such as amino acids, pyrrolidone carboxylic acid, and urocanic acid, is important in dermatology research.

Preparation for Humidity Control Composite Paperboard and their Humidity Control Properties

The humidity control composite paperboard with excellent humidity control performance was prepared, comprising sodium chloride, anhydrous potassium carbonate, diatomite, pyrrolidone carboxylic acid-Na, carboxymethyl cellulose and self-made humidity control material. The moisture absorption and desorption rate of the sample are about 0.6231 (g/7h•g-1) and 0.5852 (g/7h•g-1), respectively. The equilibrium humidity fluctuates from 52% to 56% and moisture capacity is 31 %. Moreover, it can reach to the equilibrium levels within 60 minutes. Above all, it shows outstanding humidity control properties, meeting the requirement of micro-environment particularly for something sensitive to humidity such as cultural relic.

Regulatory responses to an orald-glutamate load: formation ofd-pyrrolidone carboxylic acid in humans

Previously published studies have shown d-glutamate to be the most potent natural inhibitor of glutathione synthesis known, yet how d-glutamate is handled in humans is unknown. Therefore, we administered an oral d-glutamate load to four healthy volunteers and monitored the plasma d-glutamate concentration and excretion over a 3-h postload period. Compared with time controls, the plasma d-glutamate concentration increased 10-fold in the 1st h and then reached a plateau over the remaining time course. In contrast, plasma d-pyrrolidone carboxylic acid increased progressively throughout the 3-h time course to a level 10-fold higher than the d-glutamate plasma concentration. Excretion of d-glutamate progressively increased despite a constant filtered d-glutamate load rising from only 5 to 95% of the filtered amount. Excretion ofd-pyrrolidone carboxylic acid increased with the rise in filtered load without significant reabsorption. The amount ofd-pyrrolidone carboxylic acid excreted over the 3-h time course was 10 times the amount excreted as d-glutamate and accounted for almost 20% of the administered d-glutamate. These findings indicate that plasma d-glutamate concentration is tightly regulated through two mechanisms: 1) the transport into cells and metabolic conversion tod-pyrrolidone carboxylic acid and excretion, and 2) the enhancement of d-glutamate clearance by the kidneys.