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find Keyword "Mechanism" 30 results
  • Study of Mechanism of Preoperative Oral Carbohydrate Involved in Attenuating Postoperative Insulin Resistance

    Objective To assess the tolerance of preoperative carbohydrate-rich beverage, to determine its effect on postoperative insulin resistance and analyze its potential mechanism. Methods Thirty-two patients undergoing elective colorectal cancer resection were recruited to this randomized controlled study and assigned to two groups at random. Patient in control group was fasted before operation, while patient in study group was given oral water. Homeostasis model assessment (HOMA) indexes, activity of PTK, and mRNA and (or) protein expressions of PKB, PI3K and GluT4 were measured before and (or) immediately after surgery. Furthermore preoperative well-beings of patients were studied. Results Among well-beings, feeling of thirst, hunger and anxiety tended to be better in patients receiving carbohydrate-rich beverages compared with fasted ones (P<0.05). Whole body insulin sensitivity decreased by 33% in the study group while 38% in the control group (P=0.007 2), and the activity of PTK, expressions of PI3K and PKB in study group were higher than those in control group (P<0.05, P<0.01), but no significantly difference was observed about GluT4 in both groups (Pgt;0.05). Conclusion Preoperative consumption of carbohydrate-containing fluids is safe and effective. Provision of carbohydrate energy source prior to surgery may attenuate immediate postoperative insulin resistance. A carbohydrate-rich drink enhances insulin action at the time of onset of anaesthesia or surgery by activating three kinases named PTK, PI3K, PKB which are key enzymes in pathway of insulin signal transduction. It is likely to explain the effects on postoperative insulin resistance.

    Release date:2016-09-08 11:07 Export PDF Favorites Scan
  • Plasma Exchange for Severe Haemolysis During ReCardiopulmonary Bypass to Patients with Cardiac Surgery

    Abstract: Objective To summarize the clinical experience of plasma exchange (PE) during recardiopulmonary bypass (CPB) of patients with severe haemolysis in cardiac surgery. Methods Between January 2001 and December 2005, five patients required PE for severe haemolysis after cardiac surgery. There were periprosthetic leakage and infective endocarditis in 3 patients, congenital heart disease of pulmonary artery stenosis with unsatisfied right ventricular outflow tract patching in 1 patient and thrombosis during extracorporeal membrane oxygenation (ECMO) in 1 patient. They all need blood purification to avoid acute renal failure. Results Five patients were successfully treated with PE during CPB without major complications. The amount of plasma and blood transfused in the 5 patients were 2.2±0.8L and 0.6±0.3L respectively. The volume of plasma exchange and ultrafiltrate were 3.9±1.8L and 2.4±1.3L respectively.The electrolytes and bloodgas analysis in all patients were maintained at the normal levels. The hemodynamics was stable. After heart resuscitation CPB stopped smoothly. Disappearance of periprosthetic leakage and satisfaction of right ventricular outflow tract patching were observed by echocardiograms after peration.Extubation was performed 24h after the operation in 5 patients, and they were discharged 12 to 53 d after the operation with fully recovery. The urine was clear and the body temperature was normal. Before they left thehospital, the concentration of free hemoglobin was tested in 3 patients. The concentration of free hemoglobin was slightly higher in 1 patient (68mg/L), and normal in 2 patients (lt;40mg/L). Conclusion PE during CPB in severe haemolysis is a safe technique which can effectively prevent acute renal failure caused by severe mechanical haemolysis after cardiac surgery.

    Release date:2016-08-30 06:15 Export PDF Favorites Scan
  • PROGRESS IN RESEARCH ON THE MECHANISM OF DENERVED SKELETAL MUSCLE ATROPHY

    Objective To summarize the recent progress in research on the mechanism of denerved skeletal muscle atrophy. Methods The recently-publ ished l iteratures at home and abroad on denerved skeletal muscle atrophy were reviewedand summarized. Results The mechanism of denerved skeletal muscle atrophy was very complex. At present, the studyof the mechanism was based on the changes in histology, cytology and molecules. Fiber thinning and disorderly arrangement of denerved skeletal muscles were observed and apoptotic bodies were detected. Apoptosis-promoting genes expressed upregulatedly and apoptosis-restraining genes expressed down-regulatedly. Muscle satell ite cells increased after denervation, but then they decreased and disappeared because they could not differentiate to mature muscle fibers. The structural change of cytomiscrosome and down-regulation of metabol ism-related enzymes induced cell metabol ism disorder. Conclusion The histological change of skeletal muscle fibers, the change of the number of muscle satell ite cells and differentiation, the structural change of cytomiscrosome and the change of apoptosis-related and metabol ism-related gene expressions contribute to denerved skeletal muscle atrophy.

    Release date:2016-09-01 09:19 Export PDF Favorites Scan
  • Mechanism of Spontaneous Rupture of Hepatocellular Carcinoma

    【Abstract】ObjectiveTo study the mechanism of spontaneous rupture of hepatocellular carcinoma (HCC). MethodsArticles have been reviewed to find out the theory of spontaneous rupture of HCC. ResultsResearchful results suggested that the injury of small arteries was usually followed in patients of spontaneous rupture of HCC. In this review, the immune complex, which composed of hepatitis B virus e antigen, complement C1q and immunoglobulins, was found deposited in the elastic membrane of arteries. Likely as a result of immune complex deposition, vascular injury occurs mainly in the small arteries where the deposition of immune complex was present. The small arteries in which immune complex deposited are readily injuried and cause hemorrhage and rupture of HCC during vascular load increase. ConclusionWe would conclude that immune complex deposition in vessel wall led to the small arteries injury may be the factor involved in the pathogenesis of spontaneous ruptured HCC.

    Release date:2016-09-08 11:52 Export PDF Favorites Scan
  • DEVELOPMENT PROGRESS OF MESENCHYMAL STEM CELLS SENESCENCE

    ObjectiveTo summarize the research situation of mesenchymal stem cells (MSCs) senescence, including the characteristics and mechanisms of senescence. MethodsThe original articles in recent years about MSCs senescence were extensively reviewed, and comprehensively analyzed. ResultsThe senescence of MSCs which manifests as morphological senescence, reduced proliferation and differentiation potential, altered immunoregulation are found during the cultivation in experiment, which profoundly affects clinical application of MSCs. The research about the mechanisms of MSCs senescence includes telomere and telomerase, and stress-mediated injury etc, involving regulation of telomerase, and regulation of signal pathways of p53/p21, P13K/Akt, and Wnt/β-catenin etc. ConclusionThe further study of senescence mechanisms will help to accelerate the clinical application of MSCs in the future.

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  • Advances in Erythropoietin's Myocardial Protective Effects

    Erythropoietin (EPO) is known as a classical hematopoietic growth factor, which has been used to treat anemia caused by different reasons. In recent years, EPO's non-hematopoietic biological effects have gradually become a focus. Among these effects, EPO's tissue protection is most attractive and EPO has been proved to protect many different tissues and organs. Myocardial protection has always been the important and key topic in the field of cardiovascular diseases. Reports about EPO's myocardial protective effects have been published in the recent two years, which direct the research about myocardial protection with new ideas. In this article, the discoveries and unsolved problems associated with EPO's myocardial protection were reviewed.

    Release date:2016-08-30 06:18 Export PDF Favorites Scan
  • Mechanism of TGF-β/Smad Signaling Pathway Regulating Epithelial-mesenchymal Transition in Tracheal Stenosis after Transplantation

    ObjectiveTo investigate that the TGF- beta/Smad signaling pathway mediated epithelial mesenchymal transition (EMT) in trachea stenosis after transplantation. Methods180-220 g male rats (n=50) were randomly divided into a control group and an experimental group. no surgical operation rats were in the control group. tracheal transplantation rats (Wistar-SD rat) were in the experimental group. Graft specimens were obtained in rats on 3,7,10,14,35,90 days after operation. HE staining is used to explain the fibrosis degree of tracheal stenosis. The fibrosis degree of tracheal stenosis was detected by calculating the fibrosis rate. Immunohistochemical staining was used to detect transplanted tracheal, such as EMT related molecules E-cadherin, vimentin, alpha-SMA expression, p-Smad2/3 expression and transcription factor ZEB1, Snail1 expression in tracheal graft specimens. ResultsHE staining showed that the tracheal fibrosis rate of the control group was 0.171±0.020, fibrosis rate was 0.537±0.013 (P < 0.01) on the third day after transplantation. The result of immunohistochemical staining showed that vimentin positive epithelial cells increased significantly (P < 0.05). E-cadherin expression significantly reduced (P < 0.05). Compared with the control group, TGF- beta expression increased (P < 0.05) in the experiment group. Compared with the control group, the expression of p-Smad2/3, the transcription factor ZEB1 and Snail1 significantly increased (P < 0.05) in the experiment group. ConclusionMechanism of tracheal stenosis may be due to EMT. At the same time, TGF- beta/Smad signaling pathway and transcription factor ZEB1, Snail1 may regulate the EMT.

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  • BASIC RESEARCH ON THE MECHANISM OF VENOUS REVERSE FLOW IN REVERSE-FLOW ISLAND FLAP

    Objective To investigate the basic mechanism of venous flow in reverseflow island flap. Methods Recent relevant literature on the mechanism of venous reverse flow in reverseflow island flap wereextensively reviewed. Results The mechanism of venous reverse flow was a multifactorial phenomenon. “Communicating and collateral by pass route” and “incompetent valve route” were two theories. Conclusion The two routes of venous reverse flow in reverse-flow island flap coexistand complement each other.

    Release date:2016-09-01 09:30 Export PDF Favorites Scan
  • Protective Effects of Recombinant Human Growth Hormone on Intestinal Barrier Function

    Objective To investigate the protective effects and the mechanism of recombinant human growth hormone on the intestinal barrier function. Methods The literatures of recent years were reviewed and summarized. Results The recombinant human growth hormone not only prevent mucosal cells and immunological cells from apoptosis, but also antagonize the damage of NO, cytokines, as well as endotoxin on intestinal barrier. What’s more, it increases the intestinal uptake and utilization of glutamine. All of the above could maintain the integrity and functions of the intestinal barrier. Conclusion The recombinant human growth hormone protects the intestinal barrier function through different ways.

    Release date:2016-09-08 10:56 Export PDF Favorites Scan
  • Mechanism of Mesenchymal Stem Cells Transplantation for Chronic Hindlimb Ischemia in Lewis Rat

    Objective To explore the mechanism of mesenchymal stem cells (MSCs) transplantation for chronic hindlimb ischemia in Lewis rats by using cell tracer technique. Methods MSCs were isolated and cultured by using density gradient centrifugation and adherence method respectively, then labeled by 5-bromo-2-deoxyuridine (BrdU). Eight chronic hindlimb ischemia models of Lewis rats were prepared by using suture-occluded method and then divided randomly to MSCs transplantation group and control group, each group enrolled 4 rats, accepting MSCs transplantation and saline respectively. Then on 7 days and 14 days after transplantation, clinical observation, determination of blood flow, and angiography were performed on rats of the 2 groups. At the same time points after previous tests, rats of the 2 groups were sacrificed to get quadriceps tissues and gastrocnemius tissues to perform HE staining and BrdU immunohis-tochemistry. Results The 8 rats were all survived on 14 days after transplantation, with no tumor happened and necroses in the transplanted area. On 14 days after transplantation, the blood flow ratio of operated side to un-operated side in the hindlimb (1.773 vs. 1.279) of rats in MSCs transplantation group and control group increased, and the angiography results showed that there were no much increase in ratio of collateral vessels number (0.908 vs. 0.835). There were no significant change in the quadriceps tissues and gastrocnemius tissues by HE staining. The BrdU positive kernels located in the inter-stitial substance cells and vascular endothelia cells, and divided differently in different parts of hindlimb at different time points, that the ratio of positive cells in gastrocnemius tissue was higher than those of quadriceps tissue on 7 days after transplantation, but lower on 14 days. Conclusions MSCs transplantation can increases the blood perfusion of hindlimb in the early stage of chronic hindlimb ischemia model, and the possible mechanism may be the paracrine effect of MSCs but not the number increase of collateral vessels.

    Release date:2016-09-08 10:34 Export PDF Favorites Scan
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