Combined pre-conditioning with salidroside and hypoxia improves proliferation, migration and stress tolerance of adipose-derived stem cells.

Oxidative stress after ischaemia impairs the function of transplanted stem cells. Increasing evidence has suggested that either salidroside (SAL) or hypoxia regulates growth of stem cells. However, the role of SAL in regulating function of hypoxia-pre-conditioned stem cells remains elusive. Thus, this study aimed to determine the effect of SAL and hypoxia pre-conditionings on the proliferation, migration and tolerance against oxidative stress in rat adipose-derived stem cells (rASCs). rASCs treated with SAL under normoxia (20% O2 ) or hypoxia (5% O2 ) were analysed for the cell viability, proliferation, migration and resistance against H2 O2 -induced oxidative stress. In addition, the activation of Akt, Erk1/2, LC3, NF-κB and apoptosis-associated pathways was assayed by Western blot. The results showed that SAL and hypoxia treatments synergistically enhanced the viability (fold) and proliferation of rASCs under non-stressed conditions in association with increased autophagic flux and activation of Akt, Erk1/2 and LC3. H2 O2 -induced oxidative stress, cytotoxicity, apoptosis, autophagic cell death and NF-κB activation were inhibited by SAL or hypoxia, and further attenuated by the combined SAL and hypoxia pre-treatment. The SAL and hypoxia pre-treatment also enhanced the proliferation and migration of rASCs under oxidative stress in association with Akt and Erk1/2 activation; however, the combined pre-treatment exhibited a more profound enhancement in the migration than proliferation. Our data suggest that SAL combined with hypoxia pre-conditioning may enhance the therapeutic capacity of ASCs in post-ischaemic repair.

[The Establishment of Atrial Septal Defect Model in Pigs with Extracorporeal Circulation Followed by Patch Repairment].

OBJECTIVE: To investigate the establishment of atrial septal defect model with high success rate in pigs with extracorporeal circulation and the method of followed patch repair. METHODS: Twenty Chinese miniature pigs weighing 45.3-55.7 kg were used, four of which were used for blood donationand the remaining for models. General anesthesia was conducted with intubation. Thoracotomy was performed through the right fourth intercostal space, and the ascending aorta cannulation with a wire-guide technique was carried out. The extra-pericardial method was used for the superior and inferior vena cava cannulation. The ascending aorta was not cross-clamped. After snaring the superior and inferior vena cava, the right atrium was opened on pump. Sutures were preset and a clamp was used to create and expand an interatrial septal hole followed by the implantation of the experimental patch. RESULTS: One animal died due to the aortic root torn and hemorrhage while exposing the right atrial appendage. The remaining 15 pigs successfully completed the operation. Among these 15 experimental animals, one had postoperative hypotension. The average pressure was decreased to 38 mmHg (1 mmHg=0.133 kPa), which was corrected by vasoactive agents and fluid resuscitation. One animal had intraoperative cardiac arrest and was resuscitated by heart massage. Fifteen experimental animals were raised for 6 months and all survived. CONCLUSION: The selection of suitable experimental animals like swine and well-established surgical methods could ensure the success establishment of experimental models and patch repairment.

MicroRNA-1 Regulates the Differentiation of Adipose-Derived Stem Cells into Cardiomyocyte-Like Cells.

Stem cell transplantation is one of most valuable methods in the treatment of myocardial infarction, and adipose-derived stem cells (ASCs) are becoming a hot topic in medical research. Previous studies have shown that ASCs can be differentiated into cardiomyocyte-like cells, but the efficiency and survival rates are low. We investigated the role and mechanism of microRNA-1 (miR-1) in the differentiation of ASCs into cardiomyocyte-like cells. ASCs and cardiomyocytes were isolated from neonatal rats. We constructed lentivirus for overexpressing miR-1 and used DAPT, an antagonist of the Notch1 pathway, for in vitro analyses. We performed cocultures with ASCs and cardiomyocytes. The differentiation efficiency of ASCs was detected by cell-specific surface antigens. Our results showed that miR-1 can promote the expression of Notch1 and reduce the expression of Hes1, a Notch pathway factor, and overexpression of miR-1 can promote the differentiation of ASCs into cardiomyocyte-like cells, which may occur by regulating Notch1 and Hes1.

Single-stage surgery experience in a case of coarctation of the aorta with an arch aneurysm combined with severe coronary artery disease.

The best surgical approach for coarctation of the aorta (COA) combined with other cardiac diseases is uncertain. The simultaneous intracardiac repair of complex pathologies is desirable because multistage procedures may lead to a higher rate of mortality. We describe a case involving a 61-year-old woman who was suffering from COA with a concomitant arch aneurysm and coronary artery disease. We managed her case via single-stage surgery that included a median sternotomy.

[The predictive values of EuroSCORE of early mortality in coronary artery bypass grafting patients].

OBJECTIVE: To verify the predictive value of EuroSCORE of early mortality in coronary artery bypass grafting (CABG) patients. METHOD: From January 2005 to March 2007, 310 consecutive patients were operated with CABG. Detailed data for the EuroSCORE risk factor were collected and all patients were scored according to the EuroSCORE additive model, retrospectively or prospectively. Expected or predicted mortality was calculated for individual patients using the EuroSCORE algorithms, arranged sequentially in order of predicted score. The population was divided into three clinically relevant risk categories according to the range of predicted mortality rate. Expected mortality was compared to observed or actual mortality for each risk category. Mortality was defined as death from any cause within 30 days of operation or within the same hospital admission. RESULTS: Preoperative overall patients: low-risk group was 25.2% (78/310), middle-risk group was 48.4% (150/310), high-risk group was 26.4% (82/310). In the EuroSCORE model, predicted mortality was 1.4% for low-risk group, 2.7% for middle-risk group, 7.4% for high-risk group, and 3.6% for overall patients. Actual mortality was 0, 1.3% and 3.7% respectively, overall early mortality was 1.6%. Area under the ROC curve was 0.78. CONCLUSION: The EuroSCORE yield good predictive value for hospital mortality of patients undergoing CABG, especially in off-pump CABG.

[Assessment of early mortality risk factors undergoing coronary artery bypass graft surgery].

OBJECTIVE: To analyze early mortality risk factors and clinical characteristics in our patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: Clinical data of 310 consecutive patients undergoing CABG from January 2005 to March 2007 were collected. Twenty-two risk factors were evaluated by univariate and multivariate Logistic stepwise regression analysis. RESULTS: Univariate statistical analysis revealed that factors significantly correlated with early death were 12 variables including age, diabetes, neurological dysfunction, old myocardial infarction, acute myocardial infarction, ejection function, left main artery stenosis, emergency procedure, cardiopulmonary bypass time, aortic cross-calming time, and mechanical ventilation time. Logistic stepwise regression analysis showed that emergency procedure, ejection function, age, cardiopulmonary bypass time, and mechanical ventilation time were independent risk factor of early mortality after procedure. CONCLUSION: Emergency procedure, ejection function, age, cardiopulmonary bypass time, and mechanical ventilation time are independent risk factors of early mortality after CABG procedure.

Flow of power-law fluids in self-affine fracture channels.

The two-dimensional pressure driven flow of non-Newtonian power-law fluids in self-affine fracture channels at finite Reynolds number is calculated. The channels have constant mean aperture and two values zeta=0.5 and 0.8 of the Hurst exponent are considered. The calculation is based on the lattice-Boltzmann method, using a different technique to obtain a power-law variation in viscosity, and the behavior of shear-thinning, Newtonian, and shear-thickening liquids is compared. Local aspects of the flow fields, such as maximum velocity and pressure fluctuations, are studied, and the non-Newtonian fluids are compared to the (previously studied) Newtonian case. We find a scaling relation between permeability and mean aperture in the low Reynolds number regime, generalizing an earlier result for Newtonian fluids. As the Reynolds number increases, we observe the same sequence of transitions to nonlinearity found in intergranular porous media. Furthermore, the permeability results may be collapsed into a master curve of friction factor vs Reynolds number, using a scaling similar to that employed for power-law fluids in porous media.