BACKGROUND:Current research on mesenchymal stem cels (MSCs) is mostly focused on its immune regulatory function, while little is reported on the antioxidant capacity of the cels and culture supernatant.OBJECTIVE: To investigate the anti-oxidative capacity of the supernatant harvested from human fetal placenta MSCs (fPMSCs) under a condition of serum free culture. METHODS:fPMSCs were cultured with serum free media, and the supernatants of cels at passages 2-6 were colected at 48 hours after culture. Vitamin C was added into the culture medium, as a positive control, and its concentration was 100 μmol/L. The total antioxidant capacity, scavenging capacity of free radicals and antioxidant enzymatic activities of supernatants were measured. RESULTS AND CONCLUSION: By comparing anti-oxidative activities of vitamin C and na?ve culture medium, supernatants colected from fPMSCs cultures exhibited obvious antioxidant capacities at different extents between passages of cel cultures. The total antioxidant capacity of the culture supernatant was comparable to 40-80 μmol/L vitamin C. In addition, al supernatants derived from cels with different passages displayed capacities to scavenge free radicals, including 2,2-diphenyl-1-picrylhydrazyl radical (DPPH?), hydroxyl radical (?OH), superoxide anion radical (O2-). Even more, activities of antioxidant enzymes, including superoxide dismutase and glutathione peroxidase, were also detected in supernatants colected from different passages of fPMSCs. Under the serum-free condition, the culture supernatants of fPMSCs have antioxidant capacities at certain extent. However, the antioxidant components and underlying mechanisms need to be further studied.

Amyloidosis ; Cardiomyopathy, Hypertrophic ; Humans

OBJECTIVE: To design a series of geometric indexes, which can improve the correlation between geometric parameters and dosimetric parameters. METHODS: 48 cases of upper abdomen were selected. Manual and automatic segmentation were performed for two organs at risk, which were stomach and duodenum. Three overlapping structures, which were the overlaps with target expanded by 5 mm, 10 mm and 20 mm, were generated for each organ at risk. The geometric parameters of overlapping structures were calculated. The relationship between these geometric parameters and the dosimetric parameters of organs was investigated. RESULTS: When the geometric parameters of overlapping structures related to the target expand 5 mm, 10 mm and 20 mm were larger than 0.4, 0.6 and 0.8 respectively, the maximum dose differences of manual and automatic segmentation were less than 3 Gy. For the case with no overlaps between the organs and the target expansions, the overlap structure corresponding to target expanding 20 mm were recommended for safety considerations. CONCLUSIONS For organs at risk in the upper abdomen, the overlapping geometric parameters were closely related to the maximum dose of organs. Overlapping geometric parameters could predict whether the difference of maximum dose caused by automaticsegmentation was clinically acceptable or not.
Organs at Risk ; Radiometry ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Radiotherapy, Intensity-Modulated