Objective To investigat the safe time of SVC interruption in New Zealand rabbits, and help to find the safe time ofSVC interruption in chnical operation. Methods 25 New-Zealand rabbits were separated into 3 groups randomly. Bi-SVC was cross-clamped for one hour, two hours in animal models. The femoral artery or SVC pressures were monitored. The control group (sham op-eration group, 5) were opened chest both sides and monitored femoral artery pressure and SVC pressure for 2 hours. Samples of cere-brum, cerebellum and medulla of rabbits immediately post-operation were studied for water content, light and electric microscopies.The tiny change of brain cells in brain mantle, hippocampus and thalamencephal were observed under electron microscope. Results(1) The SVC pressure of rabbits varied regularly in occlusion groups, which displayed as "upgrade-degression- upgrade again-retain".(2) There was no obvious difference in water content of brain between the one hour group and the control group, both of which weremuch lower than two hours group. (3) The brain tissues were almost in normal construction in one hour group, but encephaledema wasobserved in two hours group. The pathological change of cony brain cells was light and reversible in one hour group. However, in twohours group, necrosis of neuron ceils in brain could be observed, which was irreversible. Concerto The animal model of acuteSVC obstruction was built successfully. Interruption of the SVC for 1 hour was proved safe, with longer interruption of SVC 2 hours,obvious encephaledema and necrosis of neuron cells can be observed.

The biological characteristic of carcinomas is determined both by the stromal microenvironment and the oncogene or anti-oncogene.The tumor stroma is also known as the reactive stroma which is composed of base member,immunocell,capillary,fibroblasts and ECM.Fibroblasts are the majority of tumor stromal cells.The relationship between fibroblasts and the initiation,progression of carcinoma has being in the spot light.In this review,we summarized the advance in the study of carcinoma-associated fibroblasts.

Objective:To evaluate the treatment effects of the half-columnar shaped mandibular block bone onlay grafting technique for augmentation of the resorbed maxillary anterior alveolar ridge after single tooth missing.Methods: A total of 15 sites of 14 patients received ridge augmentation surgeries.The recipient sites were prepared with trephines,the half-columnar shaped bone blocks were harvested from the ramus and external oblique ridges with trephines according to diameters of the recipient sites.The bone blocks were placed as lateral onlay grafts on recipient beds and secured by means of titanium screws.Particulate bone was added and absorbable membranes were used to stabilize and protect the grafts.After a mean interval of 4.5 months of healing the flaps were re-opened,the screws were removed and non-submerged implants were placed.The width and height of the alveolar ridges were recorded.After 3 months,implant-supported crowns were provided to the patients.One year later,the peri-impant condition and the marginal bone resorption on the proximal sites were observed.Results: Mean lateral augmentation obtained at the time of bone grafting was(3.8?0.8) mm(x?s),5 out of 15 sites exhibited a mean of 3 mm of vertical augmentation.The mean healing time was 4.5 months,the mean percentage of horizontal and vertical bone resorption in the mean time were 8% and 7% respectively.No major complications were recorded at donor sites.No implant was lost during the study period.Clinical parameters and probing depth(≤4 mm) demonstrated the presence of a healthy peri-implant mucosa after 1 year of prosthetic reconstruction.The clinical and radiographic bone observations showed no more than 1.2 mm of resorption after bone graft and implant placement.Conclusion: The half-columnar shaped mandibular bone graft(from the ramus and external oblique ridge) is a promising technique for bone augmentation in localized alveolar ridge defects after single tooth missing.This procedure offers easy access,good bone quantity for localized repair,low morbidity,decreased complaints of postoperative sensory disturbances or discomfort,minimal graft resorption,and a shorter healing time as compared with other methods for bone repair.

Objective To investigate the effects of Pseudomonas aeruginosa vaccine (PA) on proliferation and invasiveness of the hepatocellular carcinoma cell line MHCC97L with metastatic potential. Methods Proliferation, growth curve, plate efficiency, flow cytometry, transwell invasion assay, cell motility assay, scarification test, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP2) protein activity were evaluated after cells were treated with PA at various concentrations. Results PA can inhibit the proliferation and plate efficiency of MHCC97L cell markedly in a dose-dependent manner. The IC50 of cells treated with PA for 48 h and 72 h was 3.1 ×108/ml and 1.9 × 108/ml, respectively. The doubling time increased and plate efficiency decreased gradually when cells treated with 0.5 × 108/ml, 1 × 108/ml and 2 × 108/ml PA (P＜0.01). PA could induce cell cycle arrest at the G1 phase in a dose-dependent manner by flow cytometric analysis. The average amount of invading cell per field in cell invasion assay and motility assay were 4. 8 ± 1.3 and 8. 8±2.2 when cells treated with 1× 108/ml PA, which was significantly lower than that of control group (8. 6±2. 1 and 15. 6±1.2 ) (P＜0.01) Scarification test showed that the metastatic ability of cells treated with 1 × 108/ml PA significantly lower than that in the control group. Comparison between cells treated with 1 × 108/ml PA and control group, no remarkable difference was found regarding expression of VEGF and MMP2 in supernatant of cell culture. Conclusion PA can inhibit proliferation and plate efficiency of HCC cell line MHCC97L, which is in part mediated by the cell cycle arrest at the G1 phase. PA could inhibit invasiveness of HCC cell line MHCC97L, which is unrelated to the VEGF and MMP2 protein activity.

This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.

Objective To assess multi-detector CT (MDCT), MR and single photon emission computed tomography (SPECT) in detection of chronic myocardial ischemia in Chinese mini-swine models. Methods Six male pigs received MDCT scan firstly. Then Ameroid narrow ring was placed in the left descending branch and MDCT, MR were performed at the same day. On the 2nd, 27th day, SPECT was given. Coronary angiography (CAG) was given on the 28th day, and then MDCT and MRI. The animals were killed after allexaminations. The pathological examination was given at last. Results Two pigs died during the rearing and another 4 had results. Pathology showed 3 had subendocardium infarction and 1 had no infarction. CAG showed infarction in 3 pigs with stenosis more than 50%. Areas of reduced perfusion in arterial phase MSCT, first-pass MRI and SPECT were consistent to findings of TTC staining. MDCT detected that ESV on the 28th day was higher than that of preoperative and postoperative day (P<0.05), the other indexes had no difference. MRI displayed that EDV on the 28th day was higher than that of postoperative day (P<0.001), the other indexes had no differences. SV and EDV measured with MDCT were higher than those with MRI (all P<0.05). ESV and EF measured with MDCT and MRI had no statistical difference (all P>0.05). CT value of left ventricular anterior wall on preoperative, postoperative day and the 28th day were statistically different (F=10.274, P=0.011). Conclusion Arterial phase of MDCT, first-pass perfusion of MRI and SPECT all show reducing perfusion in left ventricular anterior wall corresponded to myocardial infarction with TTC staining. CT value of myocardial ischemia decreases after myocardial ischemia.

Objective To evaluate the effect and mechanism of bone morrow MSCs transplantation in swine with AMI by cell biology and molecular imaging methods including PET/CT, SPECT, and MRI. Methods Twenty?four Chinese mini?swine ( ( 25 ± 5 ) kg ) were randomly divided into 2 groups: MSCs group ( n=12) and control group ( n=12) . Myocardial infarction was induced in swine hearts by occlusion of the LAD. Thirty minutes later, the MSCs group received autologous MSCs transplantation through in?tramyocardial injection into the peri?infarcted areas (2×107,2 ml) and the control group was subjected to cell culture medium in the same way. At the 1st and 4th weeks after MSCs transplantation, myocardial glu?cose metabolism, myocardial perfusion and cardiac function were evaluated in the two groups through PET/CT, SPECT and MRI. The minimum FDG mean signal intensity ( MSI ) , summed MSI, SRS, SRS%, LVEF, ESV, stroke volume ( SV) and cardiac output ( CO) were calculated. On the 4th week, HE and Masson′s Trichrome stains were performed. Mann?Whitney u test and non?parametric Wilcoxon test were used. Results (1) As evaluated by PET in the 1st week, the MSI and summed MSI in MSCs group were less than those in control group ( 22. 10 ± 3. 18 vs 35. 70 ± 3. 02, z=-2. 65; 1 013. 50 ± 29. 37 vs 1 084. 00 ± 21?15, z=-1.97;both P<0.05) . Compared to the minimum MSI and summed MSI in the 1st week, those in MSCs group increased significantly (34.00±4.25, z=-2.81;1 075.50±28.30, z=-2.80;both P<0?01) in the 4th week. SRS and SRS% decreased in the 4th week compared to those in the 1st week (20.20±2.24 vs 23.80±1.58, (29.80±3.31)% vs (35.10±2.34)%;both z=-2.08, both P<0.05). The averaged MSI in left ventricular infarction area (MSI<70) also increased (56.25±3.54 vs 48.14±2.71;z=-2.80, P<0.01). The a?bove?mentioned parameters had no statistically significant differences in the 4th week compared to those in the 1st week in the control group (all P>0.05). (2) In the 1st week, the perfusion variables had no signifi?cant differences between the two groups ( P>0.05) . There was no significant difference in any perfusion vari?ables between the 1st and 4th weeks in the two groups, respectively (P>0.05). (3) As evaluated by MRI, the cardiac functional parameters had no significant differences between the two groups at the 1st week. In the MSCs groups, LVEF increased significantly ((54.41±2.62)% vs (47.54±2.43)%;z=-2.60, P<0.01) and ESV reduced significantly ((22.85±1.91) vs (27.07±1.67) ml;z=-2.70, P<0.01) in the 4th week com?pared to those in the 1st week; SV and cardiac CO in the 4th week also increased significantly ((29.35± 1?84) vs (26.52±1.46) ml, (2.23±0.14) vs (1.96±0.13) L/min;z=-2.09 and -1.99, both P<0?05). In the control group, there were no significant differences in the cardiac functional parameters between the 1st and 4th weeks ( all P>0.05) . Conclusions Four weeks after MSCs transplantation for AMI, cardiac func?tion and myocardial glucose metabolism improved significantly but without significant myocardial perfusion improvement. Therefore, the cardiac function improvement might be associated with increased myocardial glucose metabolism.

Objective To evaluate the value of MSCT, MRI and SPECT in detecting acute myocardial ischemia in Chinese mini-swine model. Methods A total of six male mini-pigs were recruited with a mean body weight of (21.6 ± 1.2) kg. All pigs were scanned on MSCT before the ligation of distal segment of Left anterior descending artery. Then, MSCT was rescanned every 2 h from ligation till 8 h latter.MRI, SPECT and the last MSCT scan were performed within 24 h one by one. Finally pathological examination was carried out right after the pig killed. Results One pig died during operation, the other 5 finished all the examinations. The pathological staining showed the same areas of myocardial infarction in the left ventricular anterior wall with the all the imaging findings, including low perfusion region of MSCT arterial phase at 2-24 h, low perfusion region of SPECT at 24 h and low perfusion region of MRI first pass phase at 24 h. Three of 5 pigs showed enhanced edge of low perfusion region on MSCT delayed scan at 4-8 h. The mean CT values in the region with reduced first-pass perfusion were 75.9,36.4, 35. 2,37. 8,37.4,33.3 HU on MDCT image at baseline, 2-8 h after operation and within 24 h after operation, respectively,and there were statistically significant difference of CT values ( F = 12. 341, P ＜0. 01 ) between preoperative and all postoperative MSCT scan. There were no statistically significant difference (F = 2. 278, P = 0. 792)among all postoperative MSCT scan. At baseline, 2-8 h after operation and within 24 h, the average volumes of stroke volume(SV)were 21.7,11.9,10.3,11.4,12. 3,12.6 ml, respectively, while the average volume of end-systolic volume( ESV)were 15.2,23.4,25.0,24. 4,25.3,22. 8 ml,respectively. The average volume of end-diastolic volume ( EDV ) at these time point were 37. 0,35.4,35.0,35.7,37. 6,37.5 ml,respectively and the average percentage of ejection fraction (EF) were 58.9% ,33.8% ,29. 0%, 31.9%,32.6% ,33.5% ,respectively. SV(F =22. 349, P＜0.01) ,ESV (F=8. 810, P＜0.01) ,EF(F =27. 240,P ＜ 0. 01 ) were all significantly different among all postoperative MSCT scan except EDV ( F = 2. 339, P =0. 079). Infarct size, which was defined as the proportion of the area of infarction to that of the entire heart,were (39.4 ±12.6)% for MSCT,(37.2 ± 10.0)% for MRI, (35.9 ±9.6)% for TTC, respectively.There were no significant differences of infarct size between TTC and MSCT (t =0. 612, P =0. 574), TTC and MRI (t=0.820, P=0.458), MSCTand MR (t=0. 425 ,P =0. 692 ). Conclusions MSCT,MRI and SPECT were all able to be used to detect the myocardial infarction in acute myocardial ischemia model The infarct size defined on MSCT, MRI and pathology were consistent. The density of ischemic myocardium and cardiac function did not change over the time within 24 h right after infarction.

This study was aimed to examine the effect of TREK-1 silencing on the function of astrocytes. Three 21-nucleotide small interfering RNA (siRNA) duplexes (siT1, siT2, siT3) targeting TREK-1 were constructed. Cy3-labeled dsRNA oligmers were used to determine the transfection efficiency in cultured astrocytes. TREK-1-specific siRNA duplexes (siT1, siT2, siT3) at the optimal concentration were transfected into cultured astrocytes, and the most efficient siRNA was identified by the method of immunocytochemical staining and Western blotting. The proliferation of astrocytes tranfected with TREK-1-targeting siRNA under hypoxia condition was measured by fluorescence-activated cell sorting (FACS). The results showed that TREK-1 was expressed in cultured astrocytes. The dsRNA oligmers targeting TREK-1 could be transfected efficiently in cultured astrocytes and down-regulate the expression of TREK-1 in astrocytes. Moreover, the down-regulation of TREK-1 in astrocytes contributed to the proliferation of astrocytes under hypoxia condition as determined by cell cycle analysis. It was concluded that siRNA is a powerful technique that can be used to knockdown the expression of TREK-1 in astrocytes, which helps further investigate the function of TREK-1 channel in astrocytes under physicological and pathological condition.
Animals ; Astrocytes ; physiology ; Cells, Cultured ; Gene Silencing ; physiology ; Potassium Channels ; Potassium Channels, Tandem Pore Domain ; genetics ; RNA Interference ; physiology ; RNA, Small Interfering ; genetics ; Rats

Objective To investigate the ability of magnetic resonance imaging (MRI) in tracking magnetically labeled mesenchymal stem cells (MR-MSCs) in a swine myocardial infarction (MI) model.Methods Adult Chinese mini-pigs (n = 6) were subjected to open-chest experimental MI operation.Their antegeneic bone marrow-derived mesenchymal stem cells ( MSCs ) was cultured and doubly labeled with ferumoxides and DAPL On the 14 th day after MSCs transplantation, the size and location of the myocardial infarction were assessed by using delayed-enhancement MRI (DE-MRI). Then the labeled MSCs were injected intramyocardially into peri-infarct zone and normal myocardium. At 24 hrs and 3 weeks after injection, the contrast and the volume of the MR-MSCs hypointense lesion from the MR images were acquired, and the contrast was determined using the difference in signal intensity between the hypointense and normal myocardium divided by signal intensity of the normal region.After humane euthanasia, the heart was excised and histology corresponding to MRI slices that demonstrated MR-MSCs lesions was performed.Repeated-measures ANOVA and a paired t test were used for comparison of the contrast and the volume of the MR-MSCs hypointense lesion at different time points. Comparisons between independent groups were performed with the standard Student t test.Results The labeling efficiency of ferumoxides and DAPI was 100% . On the 14 th day after the MI operation, the average percentage of infracted myocardial area was (33.6±8.9)% .Twenty- four hours after MSCs transplantation, MSCs injection sites appeared as ovoid hypointensive lesions with sharp border on T2 * images. At 24 h after injection, the signal contrast [(67.00±5.48)% vs (61.92 ±7.76)%,t = 1.65,P =0.1158] and the size [(0.56 ±0.24) cm2 vs (0.52 ± 0.25 ) cm2, t = 0.39, P = 0.7044 ] of the lesions showed no statistical difference between the peri infarct zone and the normal myocardium.At 3 weeks after injection, the signal contrast decreased and the size diminished both in the peri-infarct zone and in the normal myocardium. Moreover, the contrast of the lesions in peri-infarct zone decreased more significantly than that in normal myocardium [(26.88 +7.27)%vs (15.00 :t:4.51)%, F =20.08, P =0.0003].Post mortem analysis found the fluorescontly labeled MSCs demonstrated on histological sections.There were much more dense fluorescently labled MSCs per high power fields at injection sites of normal myocardium than at injection sites of peri-infarct zone [ (106 ±25 )/HPF vs ( 143 ± 31 )/HPF, t = - 2.47, P = 0.0293 ].In MSCs injection sites of the peri-infarct zone,the capillary density was significantly higher than that in control sites [ (13.4 ± 4.0 )/HPF vs (9.4 ±3.1 )/HPF, t = 2.49, P = 0.0229].At 3 weeks after injection, ferumoxide was contained within partial original MSCs.Conclusion Magnetic resonance imaging of MSCs is a feasible method for the in vivo tracking of transplanted stem cells and could reflect the tendency of the local stem cell quantity, but there still has limitation for the semi-quantitation of the transplanted stem cells.