Skeletal muscle possesses a remarkable ability for its regeneration and injured tissue repair. This ability depends on the activity and contributions of muscle satellite cells. Proliferating satellite cells, termed myogenic precursor cells or myoblasts, are activated and driven out of their quiescent state upon muscle injury. In this summary, we present a review to summarize the molecular regulation in skeletal satellite cells to light on the satellite cells' self-renewal mechanism.
ObjectiveTo explore clinical features and surgical strategies for patients with aortic dissection (AD) manifesting as pure aortic regurgitation (AR), avoid preoperative misdiagnosis, and provide reference for clinical diagnosis and treatment. MethodsClinical data of 5 AD patients who were preoperatively diagnosed as pure AR in Beijing Fu Wai Hospital from January 2005 to May 2012 were retrospectively analyzed. There were 4 male and 1 female patients with their median age of 41 (34-53) years. All the 5 patients were diagnosed as AD during the operation. One patient received aortic valvuloplasty, 1 patient received Wheat procedure, and 3 patients received Bentall procedure. Clinical manifestations, accessory examinations, intraoperative findings, surgical strategies and follow-up results were summarized. ResultsNo postoperative death or complication occurred in this study. Echocardiogram of patient 1 before discharge showed that transverse diameters of the ascending aorta and aortic sinus decreased with satisfactory closure of aortic valves but no AR. Echocardiogram and CT all showed normal function in mechanical valves and patent blood vessel prosthesis in the other 4 patients. All the 5 patients were followed up for 4 (1-5) years and were alive during follow-up. Echocardiogram showed normal function in mechanical valves and patent blood vessel prosthesis without paravalvular leak in 4 patients and mild AR in 1 patient. ConclusionAD manifesting as pure AR is rare and easily misdiagnosed preoperatively. Careful analysis of medical history and accessory examinations can reduce the risk of misdiagnosis. Appropriate surgical strategies should be chosen according to intraoperative findings of intimal tears and aortic sinus damage of AD.
ObjectiveTo investigate clinical outcomes of mitral valvuloplasty (MVP)for the treatment of infective endocarditis (IE)and mitral regurgitation (MR). MethodsFrom March 2002 to January 2012, 33 patients with IE and MR underwent MVP in Fu Wai Hospital. There were 23 male and 10 female patients with their age of 10-67 (35.7±17.8)years. Thirteen patients had previous cardiac anomalies. Preoperatively, there were 5 patients with mild MR, 15 patients with moderate MR and 13 patients with severe MR. There were 5 patients in New York Heart Association (NYHA)functional classⅠ, 23 patients in classⅡ, 4 patients in classⅢ and 1 patient in classⅣ. All the patients received MVP including 14 patients received MVP in active phase of IE. Concomitantly, 6 patients received aortic valve replacement, 5 patients received tricuspid valvuloplasty, 1 patient received coronary artery bypass grafting, 1 patient received resection of left atrial myxoma and 1 patient received repair of aortic sinus aneurysm. Surgical procedures included pericardial patch closure of leaflet perforation in 5 patients, leaflet excision and suturing in 17 patients, double-orifice method in 3 patients, chordae transfer and artificial chordae implantation in 5 patients, and annuloplastic ring implantation in 15 patients. ResultsOne patient died of acute myocardial infarction 7 days after the operation. All other 32 patients were successfully discharged. Echocardiography before discharge showed left ventricular end-diastolic diameter (LVEDD, 48.9±7.6 mm)and left atrial diameter (LAD, 31.7±7.4 mm)were significantly smaller than preoperative values (P=0.000). Thirty-two patients were followed up for 6-125 (73.0±38.6)months. There was no death, IE recurrence, bleeding or thromboembolism during follow-up. One patient received mitral valve replacement for mitral stenosis 3 years after discharge. There were 25 patients in NYHA func-tional classⅠ, 5 patients in classⅡand 2 patients in classⅢ. There were 4 patients with mild MR, 1 patient with moderate MR, and 26 patients had no MR. One patient had faster mitral inflow at diastolic phase (1.7 m/s). One patient had moderate aortic regurgitation. LVEDD and LAD during follow-up were not statistically different from those before discharge. Left ventricular ejection fraction during follow-up was significantly higher than that before discharge (60.9%±6.6% vs. 57.5%±6.7%, P=0.043). ConclusionMVP is a reliable surgical procedure for patients with IE and MR, and can significantly reduce left atrial and left ventricular diameter and improve cardiac function postoperatively.