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Objective@#To observe the cardiomyocytes regeneration after myocardial infarction in Chinese small pigs, analyze the mechanism of myocardial fibrosis after myocardial regeneration.@*Methods@#Nine Chinese small pigs, weight 18-20 kg, 6 pigs in the experimental group(to ligate LAD at the equal blood flow point), and 3 in the control group(no any operation was performed). Monitor the hemodynamics of the left ventricle. Cardiac specimens were taken after 4 weeks of LAD ligation, the left ventricle was divided into 17 segments, and fixed in 4% paraformaldehyde for 1 week. Hematoxylin-Eosin/(HE) staining, PTAH、Ki-67-DAB and α-sarcomeric-actin-DAB staining for pathological observation.@*Results@#Four weeks of LAD ligation, different range of infarct size could be found in all the 17 segment of left ventricle. There was significant systolic pressure difference between the proximal and distal part in the left ventricular cavity. After 4 weeks of LAD ligation, there were a large number of new cardiomyocytes around the infarction area, which connected with the original mature cardiomyocytes directly. Large number of disassembled cardiomyocytes in the infarcted area and myocardial fibers were broken, cell structure disappeared, and nuclei were scattered in fibrotic tissues.@*Conclusion@#New cardiomyocytes after myocardial infarction were derived from the mature cardiomyocytes. Myocardial regeneration, cell disintegration, and myocardial fibrosis were performed synchronously under the influence of myocardial tension.
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Objective To observe the cardiomyocytes regeneration after myocardial infarction in Chinese small pigs, ana-lyze the mechanism of myocardial fibrosis after myocardial regeneration. Methods Nine Chinese small pigs, weight 18-20 kg, 6 pigs in the experimental group( to ligate LAD at the equal blood flow point) , and 3 in the control group( no any operation was performed) . Monitor the hemodynamics of the left ventricle. Cardiac specimens were taken after 4 weeks of LAD ligation, the left ventricle was divided into 17 segments, and fixed in 4％ paraformaldehyde for 1 week. Hematoxylin-Eosin/( HE) stai-ning,PTAH、Ki-67-DAB and α-sarcomeric-actin-DAB staining for pathological observation. Results Four weeks of LAD liga-tion, different range of infarct size could be found in all the 17 segment of left ventricle. There was significant systolic pressure difference between the proximal and distal part in the left ventricular cavity. After 4 weeks of LAD ligation, there were a large number of new cardiomyocytes around the infarction area, which connected with the original mature cardiomyocytes directly. Large number of disassembled cardiomyocytes in the infarcted area and myocardial fibers were broken, cell structure disap-peared, and nuclei were scattered in fibrotic tissues. Conclusion New cardiomyocytes after myocardial infarction were derived from the mature cardiomyocytes. Myocardial regeneration, cell disintegration, and myocardial fibrosis were performed synchro-nously under the influence of myocardial tension.
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<p><b>OBJECTIVE</b>To evaluate the methods used to diagnose and surgically treat ruptured aneurysm in sinus of Valsalva (RASV).</p><p><b>METHODS</b>Thirty-seven hospitalized patients with ruptured aneurysms in the sinus of Valsalva from September 1981 to April 2001, including 21 cases (56.7%) of RASV associated with ventricular septal defects (VSD) and 11 (29.7%) with aortic valvular prolapse were given surgical interventions. Under hypothermia and extracorporeal circulation, we successfully performed the surgical correction of RASV for all 37 patients VSD repair in 21 patients, aortic valvuloplasty in 6 and aortic valvular replacement in 2.</p><p><b>RESULTS</b>There was no hospital deaths among these patients, although residual shunting occurred in two patients and acute renal failure was found one. Follow-up study of one month to 20 years in the patients undergoing repair of RASV revealed that the mostly individuals treated with operation obtained satisfactory cardiac function.</p><p><b>CONCLUSION</b>Correct diagnosis of ruptured aneurysm in sinus of Valsalva should be confirmed immediately and surgical correction should be carried out as soon as possible.</p>
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Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Aortic Aneurysm , Diagnosis , General Surgery , Aortic Rupture , Diagnosis , General Surgery , Sinus of ValsalvaABSTRACT
<p><b>OBJECTIVE</b>To study the effects of skeletal muscle satellite cells implanted into infarcted myocardium on the volume of remnant myocytes.</p><p><b>METHODS</b>Thirty-six adult mongrel canines were divided randomly into implantation group and control group. In the implantation group, skeletal muscle satellite cells taken from the gluteus maximus muscles of the dogs were cultured, proliferated and labeled with 4',6-diamidino-2-phenylindone (DAPI) in vitro. In both groups, a model of acute myocardial infarction was established in every dog. In the implantation group, each dog was injected with M199 solution containing autologous skeletal muscle satellite cells. The dogs in the control group received M199 solution without skeletal muscle satellite cells. The dogs of both groups were killed 2, 4 and 8 weeks after implantation (six dogs in a separate group each time). Both infarcted myocardium and normal myocytes distal from the infracted regions isolated were observed under optical and fluorescent microscope. Their volumes were determined using a confocal microscopy image analysis system and analyzed using SAS. A P < 0.05 was considered significant.</p><p><b>RESULTS</b>A portion of the implanted cells differentiated into muscle fiber with striations and were connected with intercalated discs. Cross-sectional area and cell volume were increased in normal myocardium. Hypertrophy of remnant myocytes in the infarcted site after skeletal muscle cell implantation was much more evident than in the control group. Cross-sectional area, cell area and cell volume differed significantly from those of the control group (P < 0.05). Hypertrophy of the cells occurred predominantly in terms of width and thickness, whereas cell length remained unchanged.</p><p><b>CONCLUSION</b>Skeletal muscle satellite cells implanted into infarct myocardium, could induce the hypertrophy of remnant myocyte cells in the infarcted site and could also aid in the recovery of the contractile force of the infarcted myocardium.</p>