ABSTRACT
Objective To explore whether hyperbaric oxygen could enhance the effects of the transplanted stem cell on treating myocardial infarction rats.Methods A total of 70 Sprague-Dawley (SD) Rats was randomly divided into four groups,sham operated,acute myocardial infarction (AMI),mesenchymal stem cells (MSCs) (Stem Cell Transplanting),and hyperbaric oxygen (HBO) + MSCs group,respectively.Myocardial infarction rat model was established,hyperbaric oxygen treatment was carried out every day at the first to 30 day after AMI.Human umbilical cord Wharton jelly mesenchyme cell was transplanted at the third day after AMI.The densities of polymorphonuclear neutrophils and macrophages in the infracted border zones and in the infarcted area of heart were determined with hematoxylin and eosin (HE) staining.The cardiac function was assessed with M-mode transthoracic echocardiography,in vivo.Results (1)Compared to MSCs group,the stem cell proliferation and survival rates were increased significantly at the forth week (276.6 ±73.8 versus 20.5 ± 12.3,P ＜0.01).(2)Compared to the AMI and MSCs groups,the infracted area and the number of inflammatory cell infiltration were significantly reduced in HBO alone and MSCs + HBO groups.(3) Compared to the AMI group,the cardiac function was significantly improved at the different degree in the other three groups;among these groups,cardiac function was significantly improved in the MSCs + HBO group (P ＜0.01),except for the volume of end-dilation (P ＞0.05).Conclusions Hyperbaric oxygenation could significantly promote the proliferation and survival rate of stem cells,and improve the cardiac function.Thus further enhance the effect of the transplanted stem cell on treating the infarcted heart.
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Objective To explore whether hyperbaric oxyGen could improve microenvironment of transplanted stem cell in myocardial infarction rats or not. Methods Sixty-six SD rats were randomly divided into four Groups:sham operated,myocardial infarction( MI),Stem Cell Transplanted( SC),hiGh oxyGen pressure ( HBO)+SC Groups respectively. MI rat model was established,and then HBO treatment was carried out every day from the first day to 30th day. Human umbilical cord Wharton jelly mesenchyme cell was transplanted on the 7th day after MI. The serum level of superoxide dismutase( SOD ) and nitric oxide( NO ) were assayed respectively by xanthine oxidase method and nitric acid reduction colorimetric technique on the lst,7th,l4th and 30th day after MI. Human Whartonˊs jelly stem cells was marked with electronic display unit for tracinG in vivo. Stem cell proliferation and survival rate were identified by immunofluorescence method. Results ( l ) Compared with MI and SC Group respectively,the level of SOD increased siGnificantly in HBO +SC Group( P<0. 05).(2)Compared with MI Group,the level of NO increased siGnificantly in HBO+SC Group all time( P<0. 05),and compared with SC Group,the level of NO also increased siGnificantly at the l4th and 30th day( P<0. 05).(3)Compared with SC Group,the stem cell proliferation and survival rate all increased siGnificantly in HBO+SC Group at the l4th and 30th day(55. 00% vs 80. 58%,34. 28% vs 79. l2%,P<0. 05). Conclusion Stem cell transplanted assisted with hyperbaric oxyGenation could siGnificantly increase the level of NO and SOD,so as to improve the stress state after MI and promot the proliferation and survival rate of stem cell.
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Objective To assess the value of exercise treadmill testing (bruce protocol) in diagnosing early atherosclerotic lesions of the lower limb. Methods Between March and September 2008, 173 outpatients with high risks of peripheral arterial disease (PAD) were enrolled randomly from the cardiology clinic of Chinese PLA General Hospital. The patients were subjected to exercise treadmill testing (Bruce protocol) and ankle-brachial index (ABI) determination, as well as lower limb artery ultrasonography within one week. Using ultrasonic findings as diagnostic criteria, the diagnostic sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of exercise treadmill testing for early atherosclerotic lesions of the lower limb were analyzed, and the diagnostic value of exercise treadmill testing was assessed using the ROC curve. Results After exercise, ABI decrement (R value) increased in subjects with high risks for PAD with atherosclerotic lesions of the lower limb aggravating. Using the presence of large atherosclerotic plaques (area > 20 mm2 ), atherosclerotic plaques and atherosclerotic lesions in lower limb arteries as positive diagnostic criteria, the area under curve of ROC was 0. 80 (95% CI: 0.72-0.88), 0.78 (95% CI: 0.71-0.85) and 0. 60 (95% CI: 0.44-0.76), respectively. Using the presence of large atherosclerotic plaques in lower extremities as positive diagnosis, R value was 0.80, with a sensitivity of 54. 0%, a specificity of 96. 7%, a LR+ of 16. 4, and a LR- of 0. 58, meanwhile, R value was 0. 85, with a sensitivity of 70.0%, a specificity of 91.9%, a LR + of 8.64, and a LR- of 0.33. Conclusions Exercise treadmill testing (Bruce protocol) in combination with ABI determination is a safe, accurate, objective tool for detecting early atherosclerotic lesions of the lower limb. Immediately after exercise, 0.85 is the cut-off R value appropriate for diagnosing large atherosclerotic plaques of the lower limb (area > 20 mm2).