BACKGROUND:Stem celltherapy research has been able to continue to observe the different types of stem cells, but there is stil no single imaging mode for a comprehensive evaluation of the effect of stem celltherapy.
OBJECTIVE:To review the tracing of cellmarkers and imaging technology in stem celltherapy and to prospect the clinical application of molecular imaging in stem celltherapy.
METHODS:The first author retrieved the PubMed for articles (January 2005 to December 2012) regarding application of molecular imaging in stem celltherapy, cellmarking methods and imaging technology, ideal imaging mode for stem celltherapy, and tracing of different stem cells using molecular imaging method. The key words were“molecular imaging, stem celltherapy, celltransplantation, regenerative medicine”in English. Twenty of 269 papers were included in result analysis.
RESULTS AND CONCLUSION:At present, the ability to continuously monitor the biological processes of the transplanted stem cells relies on the histological analysis at different times. However, molecular imaging can observe in vivo complex system functions at the molecular, cellular, organ, and whole body level. As the technology improves, the change in the molecular level can be assessed in the context of the living organism. At the same time, a number of methods are available and meeting the demands to track stem cells by molecular imaging. Imaging technology increases the feasibility of stem celltherapy, and contributes to clarify the new biological mechanism during the stem celltherapy.

Objective To investigate the gamma (γ) passing rates for volumetric-modulated arc therapy (VMAT) dosimetric verification with different techniques.Methods A total of 12 VMAT plans for the treatment of different anatomical sites in cancer patients were chosen.The Octavius 4D system was used to measure the dose distributions in two different settings:the gantry was rotating (three-dimensional (3D) and 2D γ-analysis) and the gantry was fixed at 0°(2D γ-analysis).The γ passing rates were analyzed with 3%/3 mm and 2%/2 mm criteria, using the paired t test or Wilcoxon signed-rank test.The 2D γ passing rates for different irradiation methods were calculated.Results For the 3D and 2D dose distributions obtained at a rotating gantry angle as well as the 2D dose distribution obtained at zero gantry angle, the average γ passing rates were 96.03%, 96.98%, and 98.90% for 3%/3 mm (P=0.227, P=0.000, P=0.003);82.08%, 84.04%, and 90.90% for 2%/2 mm (P=0.379, P=0.000, P=0.000).For the 2D dose distributions obtained with different irradiation methods, the average γ passing rate was 98.99% for 3%/3 mm and 93.68% for 2%/2 mm.Conclusions The VMAT dosimetric verification based on a 3D volumetric dosimeter at a rotating gantry position can be clinically useful for delivery quality assurance (QA), and can achieve the most reliable dose calculation for VMAT, which has more referential values.

Objective To investigate the feasibility of detector array in Monaco modeling for MLC parameters adjustment.Methods One parameter was fixed, and then the other parameter was changed.The γ pass rates of the test beams, namely 3ABUT, 7SegA, and FOUR L, were assessed to determine the values of leaf transmission and leaf offset.A total of 12 tumor cases from different anatomical sites were randomly selected.Two-dimensional dose verification (rack angle zero) of Step& Shot and dMLC plans as well as three-dimensional dose validation of VMAT plan were performed using Octavius 4D system.The γ pass rates were analyzed at a standard of 3%/3 mm.Meanwhile, the point dose verification for these three plans was analyzed to obtain the dose deviations.Results The values of leaf transmission and leaf offset were 0.0105 and-0.08 mm, respectively.The average γ pass rates (%) of Step& Shot, dMLC, and VMAT plans were 88.59±2.94, 87.81±3.28, and 87.45±2.24 before adjustment and 98.45±1.23, 98.9±1.01, and 96.03±1.66 after adjustment.In addition, the average dose deviations (%) according to the point dose verification were 0.85±0.75, 0.95±0.39, and 0.98±0.40 before adjustment and 0.97±0.57, 1.08±0.76, and 0.86±0.45 after adjustment.Conclusions Octavius detector 729 ionization chamber array is a feasible and reliable device in Monaco modeling for MLC parameters adjustment.

Objective To observe the effect of RNAi targeting Livin gene on biology characteristics such as apoptosis and proliferation in human prostate cancer cells.Methods siRNA expression vector targeting Livin gene was constructed and transfected into human prostate cancer cell line PC3.The expressions of Livin mRNA and protein were detected by real-time PCR and Western-blot,cell apoptosis and cell cycle were assayed by flow cytometry,proliferation and colony formation were detected by MTT and colony formation assay,and the tumor growth in vivo was observed in nude mice.Results After transfection,downregulation of Livin mRNA and protein expression in PC3 cells was observed (P＜0.01).Compared with the control group,the proliferation of cancer cells was inhibited significantly (P＜0.01) and the apoptotic ratio was (26.5±3.3) ％ (P＜0.01).The Caspase3 activity increased obviously (P＜0.05),and the experimental group showed a decreased colony formation rate (P＜0.01).The tumor volume of xenografts in nude mouse in experimental and control group was (1.79± 0.07) and (4.40 ± 0.06) cm3 respectively (P ＜ 0.01).Conclusions The siRNA recombinant expression vector targeting Livin gene was constructed and can knockdown the expression of Livin mRNA and protein.It can inhibit PC3 cell proliferation,induce apoptosis and inhibit tumor growth in vivo.

Objective To investigate mobilization of the bone-marrow-derived stem cell (BMSC) into peripheral blood by granulocyte-colony stimulating factor (G-CSF) to accelerate the renal regeneration.Methods Six-week-old transgenic C57BL/6J mice labeled with green fluorescent protein (GFP) as bone marrow donors and C57BL/6 mice without fluorescence label as recipients ( n =20 ) of bone marrow transplantation were used.All recipients received lethal dose of 8.5 Gy total body γ-ray irradiation with 137 Cs before bone marrow transplantation,and the transplantation of bone marrow mononuclear cells 2 × 105 by retrobulbar injection was done two hours later after irradiation. Bone marrow reconstruction after transplantation was proved by flow cytometry five weeks after transplantation.Six weeks after the bone marrow reconstruction completed,left renal pedicles of all mice were cross-clasped for 30 minutes followed by reperfusion to establish the animal model of ischemia-reperfusion injury.Mice were divided into two groups:( 1 ) Saline control group ( n =10),saline 0.2 ml/day was injected subcutaneously into chimeric mice from 3 days before to 4 days after operation ; (2) G-CSF mobilization group (n =10),chimeric mice were injected subcutanously with recombinant human G-CSF,200μg/kg/day,once a day from three days before surgery for a week.On the 1st day after mobilization,the percentage of stem cell in non-erythroid cells of peripheral blood was detected by using flow cytometry.One week after ischemia,the homing of BMSC to kidney was identified by flow cytometory.Renal tissue sections were stained with Hemotoxylin and Eosin staining method for pathological study,and the degree of renal tubular injury was analyzed by semiquantitative method of Vyacheslav.Four weeks after ischemia,the differences in degree of renal regeneration between the two groups by analysis the numbers of vascular endothelial cells in the kidney.Results After G-CSF mobilization,the percentage of stem cells with Sca-1 +,c-Kit +,CD29 and CD34 + antigen in peripheral blood in G-CSF mobilization group were higher than those in control group.One week after ischemia,mice of mobilization group showed higher percentage of Sca-1 +,c-Kit + and CD34 + bone marrow derived stem cells in tbe kidney compared to control group (P ＜0.05).One week after ischemia,the tubular epithelial damage score of mobilization group was lower significantly than that of the control group (P ＜ 0.05 ) studied by Hemotoxylin and Eosin staining. Four weeks after ischemia,mice of G-CSF mobilization group showed more CD31 positive cells in the kidney compared to control group (P ＜ 0.05 ).Conclusions G-CSF can effectively mediate the mobilization of bone marrow derived stem cells to peripheral blood and homing to kidney.G-CSF mobilization can accelerate renal regeneration and alleviate the degree of renal histopathological changes after ischemia.

10.3969/j.issn.2095-4344.2013.24.002

BACKGROUND:Embryonic stem cel s have the capacity of multi-differentiation potential, and have been utilized for the therapy of acute liver injury. However, the migration and proliferation of embryonic stem cel s after transplantation remains not wel characterized.
OBJECTIVE:To track the transplanted embryonic stem cel s in repairing acute liver injury by bioluminescence imaging technology.
METHODS:Murine embryonic stem cel s (D3) were transducted with a construct composed of firefly luciferase, monomeric red fluorescence protein and herpes simplex virus truncated thymidine kinase triple fusion reporter genes by lentivirus system. Stable D3 embryonic stem cel s integrating three report genes were screened. The undifferentiated embryonic stem cel s or differentiated embryonic stem cel s from the 6-day-old embryoid body were transplanted into acute liver injury model of SV129 mouse through spleen, and the transplanted cel s were monitored by bioluminescence imaging technology.
RESULTS AND CONCLUSION:Reverse transcription PCR results showed that the expression level of Oct-4 and Nanog was not affected in embryonic stem cel s transducted with triple fusion reporter gene compared with wild-type embryonic stem cel s. The migration process of transplanted cel s was visualized by bioluminescence imaging technology. Teratomas were found in both triple fusion-embryonic stem cel s treatment group and triple fusion-embryoid body cel s treatment group at liver, and the teratoma formation could be suppressed by ganciclovir administration because ganciclovir can react with herpes simplex virus truncated thymidine kinase and trigger cel necrosis process. Histological analysis showed that teratomas comprised tissues from al three germ layers. These results demonstrate that triple gene fusion does not affect differentiation potential of embryonic stem cel s and it is risky to utilize embryonic stem cel s for cel therapy, because it affects repair of liver injury. The therapy strategy requires further improvement and real-time visualizing of embryonic stem cel s in vivo is absolutely necessary.

BACKGROUND:Studies have shown that low-intensity and short-time vibration with a certain frequency can reduce the absorption of bone tissue and increase the quantity and quality of bone through promoting the proliferation and differentiation of osteoblasts.
OBJECTIVE:To investigate the effects of different frequencies of vibration strains on cycle, proliferation and differentiation potency of RAW264.7 cel s cultured in vitro.
METHODS:Passage 6 RAW264.7 cel s in good conditions were randomly divided into six groups, and each group was induced cultured with Dulbecco’s modified Eagle’s medium containing receptor activator of nuclear factor kappa B ligand. The final concentration of receptor activator of nuclear factor kappa B ligand was adjusted to 50μg/L, and then kept without changes. The non-loading group did not loaded with vibration strain, and the other five groups were loaded with 3-10 Hz, 15-35 Hz, 35-45 Hz, 50-70 Hz and 70-90 Hz vibration strains on the RAW264.7 cel s respectively. The other vibration parameters were consistent;the vibration time was 15 min/time with the vibration intensity of 0.3 g, twice per day. The cel cycle and cel proliferation were detected at 3 and 6 days after loading of vibration strains.
RESULTS AND CONCLUSION:After composite vibration loading for 6 days, the cel cycle phase in the vibration groups was changed to some extent when compared with the non-loading group. Compared with non-loading group, the cel number in the G 1 phase of the vibration group was significantly increased (P<0.01);the cel number in the S phase and G 2+M phase of the vibration group was significantly decreased (P<0.01);the vibration parameters in the vibration group were significantly decreased (P<0.01). The results indicate that different frequencies of vibration strains can affect the cel cycle and proliferation, and can inhibit the proliferation and differentiation of osteoblasts.

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 effects of parallel versus perpendicular double plating for distal humerus fracture of type C. Methods: A standardized comprehensive literature search was performed by PubMed, Embase, Cochrane library, CMB, CNKI and Medline datebase.Randomized controlled studies on comparison between parallel versus perpendicular double plating for distal humerus fracture of type C before December 2015 were enrolled in the study.All date were analyzed by the RevMan 5.2 software. Results: Six studies, including 284 patients, met the inclusion criteria.There were 155 patients in perpendicular double plating group, 129 patients in parallel double plating group.The results of Meta-analysis indicated that there were statistically significant difference between the two groups in complications (OR=2.59, 95%CI: 1.03 to 6.53, P=0.04). There was no significant difference between the two groups in surgical duration (MD=-1.84, 95% CI: -9.06 to 5.39, P=0.62), bone union time (MD=0.09, 95%CI: -0.06 to 0.24, P=0.22), Mayo Elbow Performance Score (MD=0.09, 95%CI: -0.06 to 0.24, P=0.22), Range of Motions (MD=-0.92, 95%CI: -4.65 to 2.81, P=0.63) and the rate of excellent and good results (OR=0.64, 95%CI: 0.27 to 1.52, P=0.31). Conclusion Both perpendicular and parallel double plating are effective in distal humerus fracture of type C, parallel double plating has less complications.