BACKGROUND:In the process of cardiac stem cel culture in vitro, the growth microenvironment may have some effects on the cel proliferation.
OBJECTIVE:To investigate the possible mechanism of proliferation and migration of rat cardiac stem cel s cultured in vitro.
METHODS:Cardiac tissues from 10 Sprague-Dawley rats were obtained for primary culture and subculture. Passage 3 cel s were col ected for immunofluorescence staining, and stem cel growth factor receptor (c-kit) and CD45, CD90 were detected. Cultured tissues were col ected and randomly divided into two groups:in group 1, paraformaldehyde fixation, paraffin embedding, hematoxylin-eosin staining, Masson staining, and detecting apoptotic cel s using TUNEL method were conducted;in group 2, EdU labeling of proliferated cel s, immunofluorescent detection of c-kit positive expression, matrix metal oproteinases 2, 9 and transforming growth factorβ1 using immunofluorescent staining were done.
RESULTS AND CONCLUSION:After 7-10 days of myocardial tissue culture, bright and round cel s were visible, and after adhesion, fusiform cel s exhibited strong growth and proliferation ability. Immunofluorescence staining showed a large number of c-kit, CD45 positive cel s but CD90 negative cel s. After culture, a great number of newborn cel s were found, accompanied by apoptosis of myocardial cel s. After EdU staining, the positive cel s were distributed in the myocardial gap, and showed a smal amount of matrix metal oproteinases 2, 9 and transforming growth factorβ1, while in the surrounding myocardium there was a large number of matrix metal oproteinases 2, 9 and transforming growth factorβ1. Taken together, our findings show that cardiac stem cel s could be obtained through myocardial tissue culture in vitro, accompanied by cel proliferation and migration. The mechanism is related to the expression of matrix metal oproteinases 2, 9 and transforming growth factorβ1.

Objective To summarize the experiences with early treatment of the wounded associated with 4 · 20 Lushan earthquake in army hospitals.Methods Emergency response programs were started and tent hospitals were set up.According to the basic principle of wartime wound treatment regulation,emergency triage,emergency medical care,transferring,specialized treatment and evacuation were performed for the wounded in this earthquake.Results After the earthquake,the emergency rescue programs were started in the hospital.Twenty minutes later,emergence medical team with full equipment were set out for the epicenter and the tent hospitals were set up.A total of 181 earthquake cases were admitted within two weeks,of which 68 (37.6％) were transferred from the scene of earthquake and 113 (62.4％) were transferred after the primary treatment (including cases evacuating from other hospitals).Forty-nine surgeries had been done,including 30 emergence ones.Thirty-four cases (including 14 severe wounded) were evacuated to superior hospitals as their vital signs turned stable.There was no death or surgical wound infection.Conclusions Peacetime complete emergence programs and materials reserves,unified and well-organized command as well as normative grading treatment system in army hospitals assure the standardized medical care with high efficiency and high quality for earthquake victims.However,more researches are needed over diagnosis methods and standards for wound severity,equipment improvement and standards for casualty evacuation.