Biomedical subjects
Publications and source records attributed to Na Li.
Two new oleanane-type triterpene saponins named pedunsaponins B (2) and C (3) were isolated from the roots of Pueraria peduncularis. Their structures were determined to be 3-O-(6-O-methyl)-beta-glucuronopyranosyl-3beta,15alpha-dihydroxyolean-12-en-16-one (2), and 3-O-beta-glucopyranosyl-(1 --> 3)-beta-glucuronopyranosyl-3beta,15alpha-dihydroxyoleana-12-en-16-one (3), on the basis of spectroscopic evidence.
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A new RLS (Resonance light scattering) probe is presented in this paper. In the Britton-Robinson buffer at pH 3.29, Arsenazo I combines with proteins by intermolecular forces, resulted in an enhanced Rayleigh light scattering. The RLS intensity reaches maximum at 400 nm and is proportional to the concentration of protein. A novel method for the determination of micro-amount of protein is developed. The assay is simple, rapid and sensitive with a detection limit at 60 ng.mL-1 and a linear range up to 18 micrograms.mL-1. This method is applied to the determination of human serum protein, and the results, compared to Bradford method, is satisfactory. The interaction of Arsenazo I with BSA, gamma-G, oval albumin, lysozyme, pepsin are investigated and the mechanism of RLS is also discussed.
This paper analyzes the scientific research guidance, author's area & units distribution, coauthor rate and quotations in "Chinese Journal of Medical Instrumentation", and offers some suggestions for the Journal so as to play an important role in scientific research in the future.
Mesenchymal stem cells (MSCs) have the potential to differentiate into distinct mesenchymal tissue cells. They are easy to expand while maintaining their undifferentiated state, which suggests that these cells could be an attractive cell source for tissue engineering of cartilage. In vitro high density micromass culture has been widely used for chondrogenesis induction. Our objective was to investigate human MSCs cell cycle, viability and differentiation in these conditions. Therefore, to induce human MSCs chondrogenesis, micromasses were cultured in the presence of transforming growth factor-beta1 in serum free medium for 21 days. Cell cycle, cell viability and cell phenotype were analyzed by flow cytometry. From day 0 to 7, the G0/G1 phase increased, whereas the S phase decreased gradually, but cell cycle phases (S, G0/G1 and G2/M) did not significantly change after day 7. Less than 10% of cells were apoptotic, but no necrosis was observed, even at day 21. We observed a decrease in CD90 and CD105 expression, from day 0 to 21. In conclusion, our results demonstrate a good viability of human MSCs in micromass culture during the whole period of culture. Moreover, micromass culture allowed human MSCs to be synchronized at the G0/G1 phase, while their phenotype suggested some degree of differentiation.