Objective To study the influence of three different ways of myogenic induction on Ca2+ regulation of mesenchymal stem cells (MSCs) derived from umbilical cord blood. Methods From January 2007 to April 2010, three different ways of myogenic induction including the adoptions of 5azacytidine, extraction of myocardium, and myocardial differentiation medium were used to induce MSCs derived from the umbilical cord blood of dogs in Xinhua Hospital of Shanghai Jiaotong University. Confocal laser scanning microscope was used to detect cells induced by the three abovementioned methods, cardiomyocytes and Ca2+ combined with Fluo3/AM inside the MSCs. For each group of cells, 2 to 5 visual fields were chosen, and 30 visual fields were recorded for each kind of cells. The mean fluorescence intensity of ten images shot in one minute was used to reflect the concentration of free intracellular Ca2+. Furthermore, the change of the concentration was continuously monitored by optical density(OD) value. Results After induction, the Ca2+ concentration inside the MSCs was significantly higher than that inside the cardiomyocytes (F=59.400, P=0.000). There was a statistical difference among the intracellular Ca2+ concentration induced respectively by 5azacytidine, extraction of myocardium, and myocardial differentiation medium (F=18.988, P=0.000). No significant difference existed between the intracellular Ca2+ concentration induced by 5-azacytidine and extraction of myocardium (OD value: 1 076.88±44.65 vs. 1 040.90±37.48, P=0.186), while the intracellular Ca2+ concentration induced by 5azacytidine was significantly higher than that induced by myocardial differentiation medium (OD value: 1 076.88±44.65 vs. 973.91±46.49, P=0.001), and the intracellular Ca2+ concentration induced by extraction of myocardium was significantly higher than that induced by myocardial differentiation medium (OD value: 1 040.90±37.48 vs. 973.91±46.49, P=0.001). The concentration of intracellular Ca2+ induced by all the three different methods fluctuated spontaneously, which was quite similar with the cardiomyocytes, but the frequency and the scope of the fluctuation were quite different. Ca2+ was released instantly by KCl stimulation in the two groups of MSCs pretreated by 5-aza and extraction of myocardium. Though MSCs pretreated by myocardial differentiation medium had response to KCl stimulation, Ca2+ could not be released in this group. On the contrary, the duration of Ca2+ release was prolonged. Conclusion Ca2+ regulation system of MSCs derived from umbilical cord blood can be influenced by these myogenic inductions. However, the reason and effect of the differences need to be elucidated by further investigation.
目的 总结单心室瓣膜反流的外科治疗经验，观察治疗效果。 方法 回顾性分析2006年7月至2012年1月上海交通大学医学院附属新华医院61例单心室患者的临床资料，其中男36例，女25例；手术年龄2个月至 20岁；体重2～58 kg。右心室型41例，左心室型13例，未定型型7例。根据瓣膜反流程度不同分为3组，无/微量反流组：28例，瓣膜未行处理；轻/中度反流组：21例，瓣膜未行处理；重度反流组：12例，手术同期行瓣膜成形。收集所有患者住院及随访资料，分析轻/中度反流组、重度反流组瓣膜反流变化趋势，以及影响瓣膜反流的因素。结果 住院死亡5例，住院死亡率8.2% （5/61）。重度反流组患者行瓣膜成形术后反流程度较术前明显减轻（由术前4.00级下降至术后2.08级）。随访56例，随访时间6～38个月，重度反流组随访10例，随访期间死亡2例，其余8例中重度反流2例，中度反流3例，轻度反流2例，微量反流1例；瓣膜反流程度增加趋势明显（由术后平均2.08级增加至平均2.75级）。轻/中度反流组随访19例，随访中无死亡，其中反流程度增加至重度3例（原1例轻度反流，2例中度反流），反流程度由轻度增加至中度3例，瓣膜反流程度由术后平均2.33级增加为平均2.58级。轻/中度反流组瓣膜反流增加率与无/轻微反流组比较差异无统计学意义（瓣膜反流增加率为31.5% vs. 19.2%，χ2=0.36，P=0.55）。单因素分析结果显示，瓣膜反流增加者在随访过程中心功能较瓣膜反流无变化或减轻者明显降低（术后左心室射血分数53.11%±5.61% vs. 59.65%±3.32%，t =-5.49，P=0.00），而左心室舒张期末容积较瓣膜反流无变化或减轻者明显增加（t =2.58，P=0.01）。 结论 单心室合并重度瓣膜反流行瓣膜成形术近期效果较好，但随着心功能下降、心室扩张，瓣膜反流程度加重趋势明显；轻/中度瓣膜反流可暂不进行处理，但部分患者瓣膜反流有增加趋势，提示应注重术后随访。
Abstract： Objective To improve therapeutic outcomes for severe leftsided atrioventricular valve regurgitation (LAVVR) after repair of atrioventricular septal defect (AVSD) through discussing pathological changes of the valve and surgical management for these patients, and summarizing the medical experiences of perioperative managements. Methods We retrospectively analyzed the clinical data of 29 patients including 16 males and 13 females with LAVVR after repair of AVSD treated in Xinhua Hospital, Medical College of Shanghai Jiaotong University between January 1995 and December 2009. The age of these patients ranged from 4 to 62 years, averaging at 26.5. According the classification of New York Heart Association (NYHA), there were 10 patients of class Ⅱ, 17 of class Ⅲ and 2 of class Ⅳ before reoperation. Partial repair of AVSD had been carried out for 18 patients, and complete repair had been performed on 11 patients. At reoperation, valve rerepair was performed on 17 patients and mechanical valve replacement (MVR) was necessary in 12 patients. Results In the early period after operation, one patient died of multiple organ failure, one patient had a permanent pacemaker inserted because of complete atrioventricular block, and 1 patient aged 4 years got recovery after 56 hours of circulatory support for severe cardiac failure after reoperation. A mean follow-up of 8.2 years (6 months to 14 years) was done for 25 patients with 3 missing. During the follow-up for 14 patients undergone heart valve repair, there was no obvious acceleration of the forward blood flow of the leftside atrioventricular valve. Ten patients had mild or less LAVVR, 1 had moderate LAVVR and 3 underwent successful left atrioventricular valve replacement at 10 days, 3 years or 6 years after reoperation because of severe LAVVR. Clinical status, as assessed by the NYHA classification, improved after surgery for LAVVR in 25 patients who were followed up with 17 in NYHA class Ⅰ, 6 in class Ⅱ, and 2 in class Ⅲ. Podoid decreased significantly and cardiothoracic ratio was 0.53-0.67 (0.60±0.11) in chest Xray picture. There was no late death. Conclusion With timely surgical treatment, and appropriate surgical method, LAVVR after complete or partial AVSD repair can be managed with excellent shortterm and longterm outcomes.