In Vitro Fatigue Test of Lung Volume Reduction Loop / 中国医疗器械杂志

Lung volume reduction loop uses bronchoscopic lung volume reduction(BLVR) technology to compress and collapse the necrotic emphysema tissue and exhaust the internal gas to achieve the purpose of lung volume reduction to treat emphysema. After the lung volume reduction loop is implanted into the human body, the compressed part of the lung tissue tends to expand with breathing, which makes the lung volume reduction loop expand into a linear trend periodically. Fatigue resistance is one of the most important performance indexes of the lung volume reduction loop. In the paper, Z-direction vibration fatigue machine was used to simulate the changes of human respiratory cycle movement to test the fatigue performance of lung volume reduction loop, which can provide some reference for the test method of in vitro fatigue performance of lung volume reduction related products in the future.

Comparison of two rat models of myocardial infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare two rat models of myocardial infarction established by coronary artery ligation and harmonic scalpel method for their advantages, disadvantages and applications.</p><p><b>METHODS</b>Sixty Sprague Dawley rats were randomly divided into sham-operated group, coronary artery ligation group and harmonic scalpel group. In the latter two groups, myocardial infarction was induced by ligation of the left anterior descending coronary artery and coagulation of the artery, respectively. Four weeks after the operations, the rats were sacrificed to measure the serum levels of CK, CK-MB, LDH and AST, and the hearts were collected for histopathological observation with HE staining.</p><p><b>RESULTS</b>The rats in the sham-operated group and coronary artery ligation group showed no significant differences in serum levels of CK , CK-MB , LDH or AST. Histologically, the myocardial tissues of the two models all showed coagulation necrosis and inflammatory cell infiltration, with granulation tissue ingrowth in the infracted tissues and scar formation. The mortality rate of the rats in coronary artery ligation group was 50% at 4 weeks, significantly higher than that of the harmonic scalpel group (20%, P<0.05).</p><p><b>CONCLUSION</b>Coronary artery ligation and harmonic scalpel method are both effective means to produce rat models of myocardial infarction. The latter method can establish a more stable model for studying the mechanism and treatment of myocardial infarction.</p>

NUSS procedure by video-assisted thoracoscopy for correction of pectus excavatum / 中南大学学报(医学版)

OBJECTIVE@#To review the management of NUSS procedure by video-assisted thoracoscopy for the correction of pectus excavatum in 18 patients, and to prevent and treat some complications.@*METHODS@#Eighteen patients with severe pectus excavatum underwent NUSS procedure by video-assisted thoracoscopy from December 2006 to September 2007.@*RESULTS@#The operation time ranged from 30 to 70 min ( average 45 min). Good Results were achieved for all patients after the operation. All of them recovered and were discharged 5 approximately 7 days after the operation. Minor complications occurred in 2 patients.@*CONCLUSION@#NUSS procedure is microinvasive and has beautiful outlook with shorter operation time and simple handling.The minimally invasive technique has a low complication rate with satisfactory short-term result. Proper management is important for the recovery at the early postoperative stage.