Objective To investigate the significance of changes of esophageal peristalsis in hiatal hernia patients. Methods 32 patients with symptom of gastroesophageal reflux(esophageal hernia 10, hiatal hernia with esophagitis 12 and esophagitis 10) and 9 patients without symptom of reflux were selected.Lower esophageal sphincter (LES) pressure ,esophageal peristaltic velocity ,amplitude and duration were detected respectively;the degree of esophagitis was identified with gastroscopy. Results LES pressures in hiatal hernia with esophagitis group and simple esophagitis group were significantly lower than those in control group , there was no significant difference between hiatal hernia group and control group . In hiatal hernia group ,the peristaltic amplitudes of proximal and distal esophagus (51.3?5.4 mmHg and 83.6?8.3 mmHg) were significantly higher than those in the other three groups , while esophagitis group was significantly the lowest . There were no significant difference about esophageal peristltic duration both of proxmial and distal esophagus between these four groups .Furthermore , distal esophageal peristaltic velocity was significantly higher in hiatal hernia group than that in the other three groups , and it was the lowest in esophagitis group .Conclusion The changes of esophageal peristalsis in patient with hiatal hernia play an important role in the pathogenesis of gastroesophageal reflux and mucosal injury.[

BACKGROUND: Increasing evidences support that the physical properties, especially stiffness, can regulate the directional differentiation of stem cells.OBJECTIVE: To review the effects of extracellular matrix on stem cell behaviors, and the research progress concerning the influence of physical properties of biomaterials on stem cell differentiation.METHODS: The first author retrieved CNKI and Web of Science databases using the keywords of extracellular matrix, bioscaffolds materials, chemical property, physical property, substrate rigidity, stem cell differentiation in Chinese and English, respectively. Finally, a total of 31 literatures were included for analysis.RESULTS AND CONCLUSION: The physicochemical properties expose effects on the cell proliferation, migration and differentiation, and especially the regulatory effect of stiffness on the cell differentiation has a revelation for tissue engineering and regenerative medicine. Searching for more biochemical and physical factors interacting with the stiffness of extracellular matrix will enable us to control cell behaviors accurately and to prepare an ideal scaffold closely similar to in vivo environment.

[ ABSTRACT] AIM:To develop the cell model of polymer/liquid crystal and to study the effect of their elasticity on the adhesion of rat bone marrow mesenchymal stem cells (rBM-MSCs).METHODS: Using the method of solvent e-vaporation induced phase separation, the cell model of polymer/liquid crystal was constructed.The surface morphology and phase separation structure were determined by polarized optical microscopy ( POM) , scanning electron microscopy ( SEM) and small angle X-ray scattering ( SAXS ) .rBM-MSCs were separated and expanded by adherent culture.The surface markers of rBM-MSCs were detected by flow cytometry.The cells were induced to osteogenic differentiation and adipogenic differentiation for 2 weeks.After 3 passages, the cells were divided into 4 groups, including total PU control group, 10%membrane group, 30%membrane group and 50%membrane group.The cells were then incubated with rhodamine phalloi-din for cytoskeleton staining and were observed under the confocal laser scanning microscope after cultured for 24 h.RE-SULTS:The cell model of polymer/liquid crystal was constructed successfully using the method of solvent evaporation in-duced phase separation.Flow cytometry results showed that the rBM-MSCs positively expressed CD29, CD44 and CD90, and negatively expressed CD34 and CD45.After stained with alizarin red S and oil red O, the calcium nodule and lipid droplets in rBM-MSCs were observed obviously.The cytoskeleton staining result indicated that the area in total PU control group, 10%membrane group and 30%membrane group were greater, and the actin microfilaments were also clearer than
that in 50%membrane group.CONCLUSION:The cell model with suitable content of liquid crystal made a contribution to the rBM-MSCs’ adhesion, but too much liquid crystal inhibits cell adhesion.

AIM:To explore a novel method to isolate human nucleus pulposus mesenchymal stem cells (hNP-MSCs) in vitro and to identify their biological characteristics.METHODS:The explant culture method was employed to isolate hNP-MSCs from nucleus pulposus tissue obtained by percutaneous endoscopic lumbar discectomy (PELD).The isolated cells were passaged for purification and cultured in vitro followed by morphological observation.The cell proliferation ability was detected by CCK-8 assay.Growth curves of the cells were drawn and surface antigens were detected by flow cytometry.The cells at the 3rd~6th passages were induced for adipogenic, osteogenic and chondrogenic differentiation, and examined by oil red O staining, alizarin red staining and Alcian blue staining.RESULTS:The cells with self-renewal were obtained from nucleus pulposus tissue obtained by PELD.The results of flow cytometry analysis revealed that the cells were positive for CD29, CD44, CD90, CD73 and CD105, but negative for CD34 and CD45.The proliferative capacity was consistent with the growth characteristics of MSCs and multilineage differentiation potential was identified.CONCLUSION:A novel method to efficiently isolate and culture hNP-MSCs,PELD combined with explant culture method,was established, which would promote the study of regenerative medicine based on hNP-MSCs.