ABSTRACT
BACKGROUND:Until now, there is yet no complete recovery from spinal cord injury in terms of structure and functional recoveries. Neurotrophic factors have limited effects on nerve regeneration. Currently, stem cel transplantation may be an effective way to repair spinal cord injury. OBJECTIVE:To separate, cultivate and purify mouse spinal cord-derived neural stem cels using serum-free suspension method folowed by morphological observation, immunofluorescence technology and multi-lineage differentiation experiments. METHODS:By using the suspension culture method, mouse spinal cord-derived neural stem cels at embryonic day 13.5 were cultured and purified. Cel morphology changes were observed under inverted microscope. Cel proliferation ability was detected using cel counting kit-8. Nestin and Sox2 expression was detected by immunofluorescence technology. Multilineage differentiation of spinal cord-derived neural stem cels at passage 4 was detected by natural differentiation method in order to prove the differentiation ability. RESULTS AND CONCLUSION: Serum-free medium suspension culture method was successfuly applied to separate spinal cord-derived neural stem cels. Cultured cels had good proliferative ability and highly expressed Nestin and Sox2 that was in accordance with the results of DAPI nucleus staining, suggesting the high purity of cels. After induction, the cels could express both Tuj1 and GFAP, indicating the cels had good differentiation potential. This experiment has successfuly established the isolation, culture, identification system of spinal cord-derived neural stem cels, providing experimental basis for subsequent studies of neural stem cels.
ABSTRACT
Objective To determine the postprandial acid distributions in patients with gastroesophageal reflux disease (GERD), and their potential relationship with esophageal acid exposure. Methods Esophageal and gastric pH were recorded in a 1 h fasting segment and a 4 h postprandial segments using a triple-channel pH catheter with three antimony electrodes, which were positioned 5 cm proximal to the upper margin of LES(LES-5 cm), 5 cm and 10 cm distal to the upper margin of LES(LES+5 cm and LES+10 cm), respectively. Esophageal acid exposure and gastric integrated acidity (IA) were calculated for each ambulatory pH study. Ten healthy subjects (HS) and 10 patients with GERD were enrolled. Results (1) Total postprandial IA had a trend to be lower at LES+5 cm than at LES+10 cm in HS, but there was no significant difference between the two positions in patients with GERD. (2)Two hours after meal, there was no significant difference of gastric IAs and baseline in HS. Whereas gastric IAs in patients with GERD returned back to a higher level than baseline: LES+5 cm: 5.4 (1.8-6.8) mmol/L?h vs 1.8(0.3-3.1) mmol/L?h (P