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Objective:To evaluate the medium and long-term clinical efficacy of the treatment of lumbar degenerative diseases in Dynesys dynamic internal fixation combined with decompression.Methods:From March 2008 to March 2015, 145 patients (84 males and 61 females, mean age 55.9±7.1 years old) with symptoms of lumbar degenerative diseases (69 lumbar disc herniation, 53 lumbar spinal stenosis and 23 I grade lumbar degenerative spondylolisthesis) were treated by the lumbar discectomy using Dynesys dynamic internal fixation combined with decompression. The clinical symptoms before and after surgery were assessed by visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) and Oswestry disability index (ODI). Lumbar lateral radiographs were used to measure the height of intervertebral space between the surgical segment and the adjacent segment. The range of motion (ROM) between the surgical segment and the adjacent segment was measured by lumbar dynamic position X-ray. Surgical and adjacent segments degenerative were classified according to the Pfirrmann grade classification.Results:The VAS score, ODI and JOA score of lower back and lower limbs in patients with lumbar disc herniation were improved from 6.6±1.7, 7.1±1.4, 63.1%±10.2%, 12.5±2.4 preoperatively to 2.6±1.0, 2.8±0.9, 30.9%±9.8%, 22.4±2.1 at the latest follow-up. The differences were statistically significant. The VAS score, ODI score and JOA score of lower back and lower limbs in patients with lumbar spinal stenosis were improved from 6.3±2.2, 6.9±1.3, 63.4%±8.5%, 12.8±2.7 preoperatively to 2.4±1.2, 2.8±1.0, 35.1%±12.0%, 22.2±2.2 at the latest follow-up. The differences were statistically significant. The VAS score, ODI score and JOA score of lower back and lower limbs in patients with I degree lumbar degenerative spondylolisthesis were improved from 5.7±2.3, 6.7±0.9, 65.7%±10.0%, 12.5±2.7 preoperatively to 2.2±1.2, 2.7±1.1, 37.0%±11.8%, 22.4±2.6 at the latest follow-up. The differences were statistically significant. Comparing to preoperational value, the height of the operative segment and caudal intervertebral space were decreased at the 1 year postoperatively and last follow-up. But the difference was not significant. As for cranial adjacent segment, the height of intervertebral space preoperatively was decreased from 12.1±1.9 mm preoperatively to 11.7±1.6 mm at 1 year postoperatively, and to 11.3±1.8 mm at the latest follow-up. The difference between them was statistically significant ( F=6.46, P=0.001). The ROM of surgical segments was decreased from 7.6°±2.2° preoperatively to 5.5°±1.6° at 1 year postoperatively, and to 2.9°±1.4° at the latest follow-up. The difference between them was statistically significant ( F=267.9, P<0.001). Conversely, the ROM of cranial and caudal segments was increased from 8.2°±2.4°, 6.5°±1.6° preoperatively to 9.1°±2.1°, 7.1°±1.9° at 1 year postoperatively, and to 10.6°±2.5°, 7.2°±1.8° at the latest follow-up. The difference between them was statistically significant ( F=38.66, 3.81, P<0.001, 0.023). At the latest follow-up, 120 (51.9%) adjacent segments were to be defined adjacent segment degeneration which includes 103 radiological adjacent segment degeneration and 17 symptomatic adjacent segment degenerations. Conclusion:Dynesys dynamic internal fixation combined with decompression could achieve satisfying mid- and long-term therapeutic effect in the treatment of lumbar degenerative diseases. The ROM of surgical segments decreased with time, although part of the ROM was still retained at the latest follow-up. However, it does not seem to avoid the degeneration of adjacent segment.
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Objective@#To summarize the effect of modified David technique on acute type A aortic dissection sinus formation.@*Methods@#From March 2018 to September 2018, modified David technique was applied to aortic sinus remodeling in acute A-type aortic dissection in 19 patients, 13 males and 6 females. The age was 45-67(50.42±15.37) years old and the weight was 45-112(60.32±25.18) kg. Single sinus(noncoronary sinus) was repaired in 15 cases, double sinus formation(noncoronary sinus+ right coronary sinus+ coronary artery transplantation) in 2 cases, left sinus Florid sleeve technical treatment plus double sinus formation(noncoronary sinus+ right coronary sinus+ coronary artery transplantation) in 1 case, Single sinus(noncoronary sinus) repaired and aortic vavle replacement in 1 case. Frozen elephant trunk and total arch replacement in 13 cases, hemiarch replacement in 3 cases.@*Results@#There were no deaths in this group. The cardiopulmonary bypass time was 176-245(193.27±32.46) minutes, the aortic cross clamp time was 105-187(122.36±18.57)minutes, and the operation time was 6.5-11.0(7.63±1.31) hours. The mechanical ventilation time was 18-122(48.27±34.73)hours, the intensive care unit stay time was 2-10(5.35±2.62) days, and the postoperative hospital stay was 7-22(12.63±3.25)days. There was no delayed sternal closure during operation, and there was no secondary thoracotomy after operation. One patient developed a transient advanced atrioventricular block. Transient neurological dysfunction was observed in 5 patients. All patients were followed up for more than half a year. The color Doppler echocardiography and computed tomography angiograph(CTA)showed no aortic regurgitation or residual dissection.@*Conclusion@#The application of modified David technique in the remodeling of aortic root sinus in acute type A aortic dissection is an effective technique with relatively simple process, which is worth promoting.
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Objective Total aortic arch replacement and stented elephant trunk surgery is an important surgical method for acute type A aortic dissection, and the short, middle, long term curative effect has been recognized by more and more experts at home and abroad.Circulatory arrest was an independent risk factor for postoperative complications and mortality in patients with type A aortic dissection.The aim of this article is to observed the effection of a new technology to block aortic arch, whicn can shorten the circulatory arrest time to 2 minutes and avoid harm of circulatory arrest on patients.Methods From May 2016 to February 2017, 68 patients with acute type A aortic dissection were divided into the conventional group and the modified group.All the patients underwent total arch replacement and stented elephant trunk surgery.The rectal temperature of the conventional group was 25℃ and circulatory arrest time was 20 min.While the rectal temperature of the modified group was 28℃ and and circulatory arrest time was 2 min.Results In the conventional operation group, 3 patients died after operation while all the patients in the modified group were cured and discharged.There are no differences between the two groups in the time of cardiopulmonary bypass(CPB) and heart arrest time(P>0.05).There are Significant differences in CPB time, circulatory arrest time, postoperative awake time, intubation time, amount of blood used, the amount of drainage during the first two days after operation, the time staying in ICU and the postoperative time in hospital.And the modified group was much better.(P<0.05)Conclusion The results of new technology blocking aortic arch in the patients with acute type A aortic dissection are better than the conventional surgical approach during the perioperative period.This technology is simple and effective.It is worth promoting.
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ObjectiveTo research the intestinal absorption characteristics in rats of multiple constituents,when Wuwei-Jiangya recipe was used in rats and showed reducing blood pressure effects.Methods ① After extracting Wuwei-Jiangya recipe,we fed it to rats once daily,until the blood pressure reduced; ②Establish Wuwei-Jiangya recipe and intestinal absorption of multiple constituents fingerprint by using reverted gut sac method and RP-HPLC fmgerprint.ResultsAfter one week's administration,there was the hypotensive effects and multiple constituents can be absorbed by intestine.ConclusionWhen the drug works,reverted gut sac method for studying intestinal absorption constituents can be used for locking the exposure constituents.
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BACKGROUND: Polypyrrole (PPy) has been widely applied in biomedical fields due to its special electronic property. Past 20 years, there are an increasing number of studies on the application of PPy as a potentially electrically addressable tissue/cell support substrate for tissue/cell regeneration.OBJECTIVE: To overall review the application of PPy in tissue engineering field, and to provide a new approach for the research and development of medical biomaterials.METHODS: Pubmed and Chinese biomedicine literature database were searched using key word of "polypyrrole" for documents published between 1990 and 2010. Literatures related to application of PPy in tissue engineering field were included, and the repetitive articles were excluded.RESULTS AND CONCLUSION: Totally 762 papers were searched by computer, according to the inclusive and exclusive criteria, 51 literature were reviewed. Currently, PPy has been widely used in the fields of cardiovascular tissue engineering, bone and muscle tissue engineering, as well as skin tissue engineering. Application of PPy and PPy-based biomaterials hold great potential in development of novel biomedical materials applied in tissue engineering due to their versatile functionality and superior biocompatibility.
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Form 2008 to 2009, four patients with complex thoracic aortic disease, including aortic aneurysms and dissections, were successfully treated in our department with a new treatment approach: hybrid procedure. Combined open surgery and endovascular repair were performed in these patients without deep hypothermia or circulatory arrest. Compared to those who underwent traditional open surgery in the same period, time of mechanical ventilation and ICU stay was decreased in these four patients. All of them were discharged soon after operation without postoperative complications or death. The result suggests that this new approach could be an option for thoracic aortic disease, but long-term and large-population studies are still required to demonstrate the safety and validity.
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Objective To compare the results of mitral valve reconstruction and replacement as treatments for moderate to severe ischemic mitral regurgitation(IMR), and report the mid-term outcome. Methods From June 2002 to May 2008, 83 pa-tients with moderate IMR(35 cases) and severe IMR (48 cases) underwent coronary artery bypass grafting(CABG) combined with mitral valvuloplasty (MVP) (n = 43) or mitral valve replacement (MVR) (n = 40). There were 49 males and 34 females with a mean age of (59.3±7.5) years(51 -77years). The procedures of MVP included annuloplasty with a Dacron or autologous per-icardium ring in 21cases, commissural annuloplasty in 9, quadrangular resection of the posterior leaflet in 9 and using St. Jude mitral annuloplasty ring in 4. In the cases underwent MVR, 28 patients received mechanical prostheses and 12 received biopros-theses. Results 30-day mortality rate was 2.3% for MVP and 5.0% for MVR (P >0.05). The 30-day complication rate was similar for the 2 groups but mechanical ventilation time was longer for MVR patients. Mild MR ocurred in 6 patients with MVP (P <0.05). Sevonty-six patients were followed by outpatient department visit or telephone for (20.2 ± 4.9) months (3 - 60 months). During the follow-up period, 7 patients with MVP had mild insufficiency but free off etber complications. All the valve prothesis functioned well. However, 3 cases had thromboembolic complications and 7 late deaths were recorded in MVR group. Five-year complication-free survival rate was 90% for MVP group and 61% for MVR. Conclusion MVP resulted in excellent durability and provided significant mid-term survival benefit over MVR. MVP should be the first choice for patients with chronic IMR.
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Objective To study the impact of NF-kappaB activation on TNF-a and IL-1β expression in myocardial ischemia/reperfusion(I/R) injury.Methods Sixty-five Sprague-Dawley rats were randomly divided into three groups:sham,n=5;I/R:30 min of myocardial ischemia followed by 0,15,30,60,120.240 min of reperfusion,n=5 per subgroup;I/R+PDTC:PDTC(15 mg/kg)was given before ischemia,and the time points were the same as those in I/R group.TNF-a and IL-1β mRNA expression was detected by RT-PCR,activity of NF-KB was measured by electrophoretic mobility shift assay (EMSA),and MDA level in myocardium was assayed by TBA method.Results The expression of TNF-a and IL-1β was increased before reperfusion,reached their peak at the time point of reperfusion 30.60 min respectively.and remained high level at the 2nd h after reperfusion.NF-KB was activated 15 min after reperfusion,reached its peak at the first h after reperfusion.In I/R+PDTC group,NF-κB activation was blocked by PDTC.As compared with I/R group,the expression levels of TNF-a and IL-1β were decreased to varying degrees at each time point.and the content of MDA was also reduced in I/R+PDTC group.Conclusion NF-KB activation could play a pivotabrole in the expression of cytokine.Inhibition of NF-κB signal pathway might be a potential therapeutic strategy in reperfusion injury.
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The study summarizes the clinical experience of surgical treatments of various types of thoracic aneurysm and aortic dissection. Clinical data of 122 patients with thoracic aneurysm and aortic dissection during July 2005 to July 2008 were retrospectively analyzed. The elective operations were performed in 107 patients while emergency surgery was done in 15 cases. Different surgical strategies were employed on the basis of diseased region, including simple ascending aortic replacement (n=3), aortic root replacement (n=43), hemi-arch replacement /total arch replacement+elephant trunk technique (n=32), thoracic/thoracoabdominal aortic replacement (n=8) and endovascular repair (n=36). In this series, there is 4 cases of perioperative death due to massive cerebral hemorrhage (n=1), respiratory failure (n=1) and multiple organ dysfunction syndrome (MODS) (n=2). Three cases developed post-operative massive cerebral infarction and the relatives of the patients abandoned treatment. Instant success rate of endovascular repair was 100%. The intimal rupture was sealed. Blood flow was unobstructed in true lumen and no false lumen was visualized. It was concluded that aggressive surgery should be considered in the patients with thoracic aneurysm and aortic dissection. Surgical procedures should vary with the location and the nature of the lesions.
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Young Adult , Aortic Dissection/surgery , Aortic Aneurysm, Thoracic/surgery , Retrospective Studies , Vascular Surgical Procedures/methodsABSTRACT
The effects of stromal-derived factor 1 preconditioning (PC) on apoptosis of bone mesenchymal stem cells (BMSCs) treated with hypoxia plus serum deprivation were investigated. Bone mesenchymal stem cells were cultured with the whole marrow-adherence technique. RT-PCR and immunohistochemistry were used to detect the expression of CXCR4. BMSCs were incubated in medium for 24 h with 10 ng/mL and 100 ng/mL SDF-1 respectively, and then they were treated with hypoxia plus serum deprivation for 6 h. Apoptosis rate was determined by flow cytometry and TUNEL method. The results showed that BMSCs had CXCR4 expression. The number of apoptotic cells was significantly reduced in SDF-1 PC group as compared with the control group, and 100 ng/mL SDF-1 PC group had the lowest level of apoptosis. It was concluded that SDF-1 preconditioning suppresses the apoptosis of BMSCs treated with hypoxia plus serum deprivation.
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Objective To investigate the effects of preconditioning (PC) with stromal-derived factor 1 alpha (SDF-1) on the levels of apoptosis of bone marrow stromal cells (BMSC) treated with hypoxia plus serum deprivation, and observe the therapeutic efficacy of cellular transplant with BMSC preconditioned with SDF-1 in rats with acute myocardial infarction. Methods BMSC were cultured with the whole marrow-adherence way. RT-PCR and immunohistochemistry were used to determine the expression of CXCR4. BMSC were incubated in medium for 24 h with 10 and 100 μg/L SDF-1 respectively, then treated with hypoxia plus serum deprivation for 6 h. The levels of apoptosis were detected by flow cytometry and TUNEL method. Acute myocardial infarction (AMI) model was established in SD rats, and BMSC preconditioned or non-preconditioned with SDF-1 were transplanted into border zone around infarct area, then heart function was measured after two weeks by ultrasonography. Results BMSC exhibited the CXCR4 expression. The number of apoptotic cells was significantly reduced in SDF-1 PC group than in control group (P<0.05), and 100μg/L SDF-1 PC group had the lowest level of apoptosis. AMI model was established successfully. Two weeks after BMSC transplant, significant improvement in cardiac function was observed in 100 μg/L SDF-1 PC group as compared with the non-PC group (P<0.05). Conclusions PC with the chemokine SDF-1 suppresses the apoptosis of BMSC treated with hypoxia plus serum deprivation. SDF-1 PC is a novel approach for enhancing therapeutic efficacy of cellular transplant in rats with AML
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In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion (I/R) in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups (n=8 in each group): control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate (EP) group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 min before ischemia and throughout reperfusion. Myocardial malonaldehyde (MDA) content was measured. Myocardial apoptotic index (AI) was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group (P<0.05). These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.
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Apoptosis , In Situ Nick-End Labeling , Malondialdehyde/pharmacology , Myocardium/pathology , Myocytes, Cardiac/cytology , Oxidative Stress , Proto-Oncogene Proteins c-bcl-2/metabolism , Pyruvates/pharmacology , Rats, Sprague-Dawley , Reperfusion Injury , Tissue Distribution , bcl-2-Associated X Protein/metabolismABSTRACT
To develop a more efficient antithrombotic way after coronary artery bypass grafting (CABG), the anticoagulant effects were compared of human tissue factor pathway inhibitor (TFPI) gene transfection and aspirin oral administration (traditional method) on vein grafts. An eukaryotic expression plasmid pCMV-(Kozak) TFPI was prepared. Animal model of carotid artery bypass grafting was constructed. In operation, endothelial cells of vein grafts in TFPI group and empty plasmid control group were transfected with pCMV-(Kozak) TFPI and empty plasmid pCMV respectively, while no transfection was conducted in aspirin control group. After operation, aspirin (2 mg.kg(-1).(-1)) was administered (i.g.) in aspirin control group. Three days later, grafts (n=10) were harvested for RT-PCR, Western blotting and immunohistochemical analyses of exogenous gene expression and for pathological, scanning electron microscopic observation of thrombus. Thirty days later, the patency rates of remnant grafts (n=10) were recorded by vessel Doppler ultrasonography. Human TFPI gene products were detected in gene transferred vein grafts. Three days later, thrombi were found in 7 animals of aspirin control group and in 8 animals of empty plasmid control group, but in only 1 of TFPI group (P<0.01). Thirty days later, 5 grafts were occluded in empty plasmid control group, but none of grafts was occluded in the other groups (P<0.05). The endothelial surfaces of grafts in both of the control groups were covered with aggregated erythrocytes and platelets, and it were not seen in TFPI group. It was suggested that the anticoagulant effects on vein grafts of human TFPI gene transfection are better than those of aspirin.
Subject(s)
Administration, Oral , Anticoagulants/metabolism , Aspirin/administration & dosage , Aspirin/metabolism , Coronary Artery Bypass , Disease Models, Animal , Lipoproteins/metabolism , Plasmids/metabolism , Tissue Transplantation/methods , Transfection , Ultrasonography, Doppler/methods , Veins/transplantation , Venous Thrombosis/metabolismABSTRACT
The effects of oxidized low density lipoprotein (ox-LDL) on the proliferation of cultured human vascular smooth muscle cells (vSMC) were investigated in vitro. By using NaBr density gradient centrifugation, LDL was isolated and purified from human plasma. Ox-LDL was produced from LDL by being incubated with CuSO(4). ox-LDL was then added to the culture medium at different concentrations (35, 60, 85, 110, 135 and 160 microg/mL) for 7 days. The influence of ox-LDL on vSMC proliferation was observed in growth curve, mitosis index, and in situ determination of apoptosis. The data were analyzed with SPSS 10.0 software. The results showed that the ox-LDL produced in vitro had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in atherosclerotic plaque. ox-LDL at a concentration of 35 microg/mL demonstrated the strongest proliferation inducement, and at a concentration of 135 microg/mL, ox-LDL could inhibit the growth of vSMC. ox-LDL at concentrations of 35 and 50 microg/mL presented powerful mitotic trigger, and with the increase of ox-LDL concentration, the mitotic index of vSMC was decreased gradually. ox-LDL at higher concentrations promoted more apoptotic vSMCs. ox-LDL at lower concentrations triggered proliferation of vSMCs, and at higher concentrations induced apoptosis in vSMCs. ox-LDL played a promotional role in the pathogenesis and development of atherosclerosis by affecting vSMC proliferation and apoptosis.
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The effects of oxidized low density lipoprotein (ox-LDL) on the proliferation of culturedhuman vascular smooth muscle cells (vSMC) were investigated in vitro. By using NaBr density gradient centrifugation, LDL was isolated and purified from human plasma. Ox-LDL was produced from LDL by being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations (35, 60, 85, 110, 135 and 160 μg/mL) for 7 days. The influence of ox-LDL on vSMC proliferation was observed in growth curve, mitosis index, and in situ determination of apoptosis. The data were analyzed with SPSS 10.0 software. The results showed that the ox-LDL produced in vitro had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in atherosclerotic plaque. ox-LDL at a concentration of 35 μg/mL demonstrated the strongest proliferation inducement, and at a concentration of 135 μg/mL, ox-LDL could inhibit the growth of vSMC. ox-LDL at concentrations of 35 and 50 μg/mL presented powerful mitotic trigger, and with the increase of ox-LDL concentration, the mitotic index of vSMC was decreased gradually. ox-LDL at higher concentrations promoted more apoptotic vSMCs. ox-LDL at lower concentrations triggered proliferation of vSMCs, and at higher concentrations induced apoptosis in vSMCs. ox-LDL played a promotional role in the pathogenesis and development of atherosclerosis by affecting vSMC proliferation and apoptosis.
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We have established a human umbilical vein endothelial cell (HUVEC) line monoclonal cells with the stable expression of human tissue-type plasminogen activator (t-PA) gene to provide a basis for further study on the vascular tissue engineering. Recombinant plasmid pcDNA3. 1-Myc-His B (-)/t-PA was constructed by insertion of t-PAcDNA originated from PBS/t-PA into eukaryotic expression vector pcDNA3. 1-Myc-His B(-) and transfected into hUVEC line cells mediated by lipofectamine. The positive clones were obtained by the screen of G418. The transcription and expression of t-PA gene were investigated by RT-PCR and Western blotting respectively. The t-PA activity was measured by chromogenic substrate assay. The positive clone cells which transcripted the mRNA of t-PA gene was obtained by RT-PCR. Immunoreactive human t-PA of the medium was significantly increased in the group of transfected gene when compared with that in the controlled and transfected plasmid without t-PA gene group. The biological activity of the protein of the t-PA in the media was increased significantly in the positive clone cells with t-PA gene transfected. The HUVEC line monoclonal cells with the stable expression of t-PA gene was established successfully.
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Humans , Cell Line , Human Umbilical Vein Endothelial Cells , Metabolism , Lipids , Pharmacology , RNA, Messenger , Genetics , Recombinant Proteins , Genetics , Tissue Engineering , Tissue Plasminogen Activator , Genetics , TransfectionABSTRACT
To investigate whether peroxisome proliferators-activated receptor-y (PPARγ) ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human saphenous vein graft were collected from 9 patients undergoing coronary bypass surgery and then divided into two equal parts of control and test specimens, were stored in ei-ther heparinized blood (control group) or heparinized blood containing 20 μmol/L troglitazone (test group) for 1 h at room temperature. Tissue distribution and protein expression of VCAM-1, ICAM-1, and endothelial nitric oxide synthase (eNOS) were compared using immunohistochemistry and West-ern blot analysis. Myeloperoxidase (MPO) activity, a marker of neutrophil sequestration in human saphenous vein grafts, was also measured in each group. The expression of ICAM-1 (753±132 versus 7201±934; P<0.01) , VCAM-1 (3731±294 versus 8292±793; P<0.01), and MPO activity (1.52±0.42 U/g, 5.04±1.26 U/g P<0.01) were significantly lower in test group. In contract, eNOS expression (7983±834 versus 3989±1008; P<0.01) was significantly higher in test group. PPARγ ligand troglita- zone might reduce endothelial injury during the storage period of human saphenous vein grafts.
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Data from 736 patients undergoing prosthetic heart valve replacement surgery and concomitant surgery (combined surgery) from January 1998 to January 2004 at Union Hospital were retrospectively reviewed. Univariate logistic regression analyses were conducted to identify risk factors For prolonged mechanical ventilation. The results showed that prolonged cardiopulmonary bypass duration, prolonged aortic cross clamp time and low ejection fraction less than 50 percent (50%) were found to be independent predictors for prolonged mechanical ventilation. Meanwhile age, weight, and preoperative hospital stay (days) were not found to be associated with prolonged mechanical ventilation. It was concluded that, for age and weight, this might be due to the lower number of old age patients (70 years and above) included in our study and genetic body structure of majority Chinese population that favor them to be in normal weight, respectively.
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In order to study the cardioprotective effects of diazoxide on the myocardial ischemia/reperfusion injury of rats and mechanisms, the healthy SD rats were randomly divided into 2 groups: the rats in the experimental group were injected with diazoxide for preconditioning with the dosage of 12.5 mg/kg through the right femoral vein and those in the control group was only administered with the equal volume of media. After 10 min, a left thoracotomy was performed and the left anterior descending branch was occluded for 2 h. Two h later, the left anterior descending branch was reperfused for 2 h and then the heart was quickly excised to be used for measurement of MDA, SOD and the infarct size, in situ cell apoptosis detection and observation of the cell ultrastructure by electron microscopy. The results showed that as compared with the control group. MDA, the infarct size and cell apoptosis in the experimental group were greatly reduced (P0.05). It was concluded that diazoxide could protect the rats from myocardial ischemia/reperfusion injury, which might be contributed to the reduction of lipid peroxidation and cell apoptosis.
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The effects of in vivo local expression of recombined human tissue-type plasminogen activator (t-PA) gene on the thrombosis and neointima formation of vein grafts were explored. Jugular vein-to-artery bypass grafting was performed on 72 New Zealand white rabbits. The rabbits were divided into 3 groups according to the different processing methods: transfected t-PA gene group (n = 24), vector group (n = 24) and blank control group (n = 24). Samples of vein grafts were harvested at different time points after surgery. The expression of t-PA gene in vein graft was detected by RT-PCR and the synthesis of t-PA protein by Western-Blot assay. The t-PA activity was measured by chromogenic substrate assay. The Cr51 labeled platelets accumulation in vein grafts was counted. The histopathological changes were compared in intima hyperplasia index among the three groups after operation. The results showed that at the 2nd, 5th, 14th and 28th day after operation, RT-PCR and Western-blot confirmed the expression of t-PA mRNA and protein at the site of gene transfer. The t-PA activity detected on the 2nd, 5th, 14th and 28th day in experimental group was 370.63 +/- 59.44, 344.13 +/- 48.47, 252.87 +/- 51.80 and 161.75 +/- 68.94 U/g respectively, and disappeared on the 60th day and undetected in the control groups. The number of platelets accumulated in the vein grafts in gene group, vector group and blank control group was (85.04 +/- 21.58) 10(6), (225.87 +/- 85.13) 10(6) and (211.7 +/- 78.02) 10(6) respectively. The number of platelets accumulated in gene group was significantly fewer than that in the control groups. Morphometric analysis revealed that intimal hyperplasia was markedly reduced in the t-PA gene group as compared with that in the control groups. It was suggested that the local expression of t-PA gene in vein graft significantly inhibited the accumulation of platelets, thrombosis and concomitant intimal hyperplasia, by which stenosis of bypass graft could be prevented effectively.