Cerenkov luminescence imaging ( CLI) , as an emerging molecular imaging method, has been extensively studied in tumor imaging, therapy monitoring and some other aspects. However, because of the weak penetration of Cerenkov radiation, CLI can not image the deep tissues. This review summarizes the modalities to overcome this problem.

Aim To assess the regulatory effects of Po-lygonatum sibiricum polysaccharides(PSP)on Toll-like receptor 4 (TLR4 )-myeloid differentiation factor 88 (MyD88)-nuclear factor κB(NF-κB)signaling path-way in anoxia /reoxygenation-H9c2 myocardial cells. Methods The H9c2 myocardial cells cultured in vitro were randomly divided into groups:control group (C group),hypoxia /reoxygenation group (H/R group), PSP group,TLR4 inhibitor group(TAK-242 group)and PSP +TLR4 inhibitor group(PSP +TAK-242 group). The cells were cultured in normal condition for 27 h in C group.The cells were subjected to 21 h hypoxia fol-lowed by 6 h reoxygenation in H/R.Definitely,the cells in TAK-242,PSP and PSP +TAK-242 groups were treated with PSP and TAK-242 with the final con-centration of 1 .5 g·L -1 and 1 μmol·L -1 for 1 2 h before 21 h hypoxia,then the cells were exposed to the normal culture condition for another 6 h.After the treatment,cell survival rate was tested by MTT method. The contents of tumor necrosis factor-α(TNF-α)and interleukin-1 β(IL-1 β)were determined by enzyme-linked immunosorbent assay(ELISA).The protein ex-pression levels of NF-κB and inhibitor κBα(IκBα) were detected by Western blot,and the expression lev-els of TLR4 and MyD88 mRNA were detected by fluo-rescence quantitative PCR method.Results Compared with H/R group,the cell survival rates were significant-ly increased,while the inflammatory cytokines contents and NF-κB protein expression were dramatically de-creased in groups PSP,TAK-242 and PSP +TAK-242, whereas the NF-κB expression was significantly down-regulated,and the IκBα protein expression was in-creased.The mRNA expression levels of TLR4 and MyD88 were markedly decreased.Conclusion PSP might protect H9c2 myocardial cells against H/R inju-ry,which may be associated with the inhibition of TLR4-MyD88-NF-κB pathway.

Objective To quantitatively compare the diagnostic capability of 68Ga-NGR and 18F-FDG in well-differentiated hepatocellular carcinoma (HCC) bearing mice by microPET/CT imaging.Methods The in vitro cellular uptake, in vivo microPET/CT imaging and biodistribution studies of 68Ga-NGR and 18F-FDG were quantitatively compared in SMMC-7721-based well-differentiated HCC.The human fibrosarcoma (HT-1080) and human colorectal adenocarcinoma (HT-29) cells/xenografts were respectively used as positive and negative reference groups for CD13.The expression of CD13 was qualitatively verified by immunohistostaining.The levels of CD13 and glucose-6-phosphatase (G6Pase) were semi-quantitatively analyzed by Western blot test for all 3 types of tumors.Two-sample t test was used for data analysis.Results The in vitro cellular uptake showed that the 68Ga-NGR uptake in SMMC-7721 and HT-1080 cells was higher than that in HT-29 cells, and the 68Ga-NGR uptake was higher than 18F-FDG uptake in SMMC-7721 cells.The in vivo microPET/CT imaging results revealed that the uptake of 68Ga-NGR in SMMC-7721 tumor was (2.17±0.21) %ID/g, remarkably higher compared to (0.73±0.26) %ID/g of 18F-FDG uptake (t=8.826, P<0.01).The tumor/liver ratio of 68Ga-NGR was 2.05±0.16, which was 2.03-fold higher than that of 18F-FDG.In the HT-1080 tumors, the uptakes of 68Ga-NGR and 18F-FDG were both high, and the values were (2.46±0.23) %ID/g, (3.47±0.31) %ID/g.The uptake of 68Ga-NGR was significantly lower than that of 18F-FDG in HT-29 tumors: (0.67±0.20) %ID/g vs (3.17±0.29) %ID/g;t=4.221, P<0.01.Western blot and immunohistostaining results were as follows: HT-1080(CD13+, G6Pase-), SMMC-7721(CD13+, G6Pase+), HT-29(CD13-, G6Pase-).Conclusions The uptake of 68Ga-NGR is higher than 18F-FDG uptake in SMMC-7721 tumor bearing mice, therefore it is worthwhile to consider the feasibility of clinical translation for PET/CT in diagnosis of HCC.Furthermore, because of the difference in 68Ga-NGR and 18F-FDG avidities in tumors with different molecular phenotypes of CD13 and G6Pase, there is an underlying potential for molecular imaging in the determination of molecular phenotypes.

Objective To quantitatively compare the diagnostic capability of 68Ga-NGR and 18F-FDG in well-differentiated hepatocellular carcinoma (HCC) bearing mice by microPET/CT imaging.Methods The in vitro cellular uptake,in vivo microPET/CT imaging and biodistribution studies of 68Ga-NGR and 18F-FDG were quantitatively compared in SMMC-7721-based well-differentiated HCC.The human fibrosarcoma (HT-1080) and human colorectal adenocarcinoma (HT-29) cells/xenografts were respectively used as positive and negative reference groups for CD13.The expression of CD13 was qualitatively verified by immunohistostaining.The levels of CD13 and glucose-6-phosphatase (G6Pase) were semi-quantitatively analyzed by Western blot test for all 3 types of tumors.Two-sample t test was used for data analysis.Results The in vitro cellular uptake showed that the 68Ga-NGR uptake in SMMC-7721 and HT-1080 cells was higher than that in HT-29 cells,and the 68Ga-NGR uptake was higher than 18F-FDG uptake in SMMC-7721 cells.The in vivo micro-PET/CT imaging results revealed that the uptake of 68Ga-NGR in SMMC-7721 tumor was (2.17±0.21) ％ID/g,remarkably higher compared to (0.73±0.26) ％ID/g of 18F-FDG uptake (t =8.826,P＜0.01).The tumor/liver ratio of 68Ga-NGR was 2.05±0.16,which was 2.03-fold higher than that of 18F-FDG.In the HT-1080 tumors,the uptakes of 68 Ga-NGR and 18F-FDG were both high,and the values were (2.46±0.23) ％ID/g,(3.47±0.31) ％ID/g.The uptake of 68Ga-NGR was significantly lower than that of 18F-FDG in HT-29 tumors:(0.67±0.20) ％ID/g vs (3.17±0.29) ％ID/g;t=4.221,P＜0.01.Western blot and immunohistostaining results were as follows:HT-1080(CD13+,G6Pase-),SMMC-7721(CD13+,G6Pase+),HT-29 (CD13-,G6Pase-).Conclusions The uptake of 68Ga-NGR is higher than 18F-FDG uptake in SMMC-7721 tumor bearing mice,therefore it is worthwhile to consider the feasibility of clinical translation for PET/CT in diagnosis of HCC.Furthermore,because of the difference in 68Ga-NGR and 18F-FDG avidities in tumors with different molecular phenotypes of CD13 and G6Pase,there is an underlying potential for molecular imaging in the determination of molecular phenotypes.

Objective Using Cerenkov radiation energy transfer (CRET) effect of rare earth nanoparticles (RENPs) to enhance and convert Cerenkov luminescence into Cerenkov luminescence excited fluorescence,and to compare the accuracy of Cerenkov luminescence tomography (CLT) and Cerenkov luminescence excited fluorescence tomography (CLFT).Methods 68Ga (0.74 MBq) was used to respectively excite Y2O3 ∶Eu3+,Er2O3 and Eu2O3(10 mg/ml).Various radioactivities of 68Ga (3.70,1.85,0.92,0.46,0.23 MBq) were used to respectively excite Y2O3 ∶Eu3+ with a fixed concentration (10 mg/ml).A fixed radioactivity of 68Ga (3.70 MBq) was used to excite Y2O3 ∶Eu3+ with different concentrations (10.0,5.0,2.5,1.2,0.6 mg/ml) in order to find the relationships between the optical intensity and the radioactivity of 68Ga or the concentration of Y2O3 ∶Eu3+.Polyethylene tubes containing 68Ga (0.74 MBq) and 68Ga (0.74 MBq) +Y2O3 ∶Eu3+(1 mg) were respectively implanted into two nude mice,then PET/CT and optical imaging were acquired.Three-dimensional reconstruction was proceeded.One-way analysis of variance,two-sample t test,linear correlation analysis were used for data analysis.Results Y2O3 ∶Eu3+ could significantly and stably enhance the Cerenkov optical signal (F=53.35,q =17.03,P＜0.001).The enhanced optical signal intensity had linear relationships with the radioactivity of 68Ga or the concentration of Y2O3 ∶Eu3+(r values:0.99and 0.93).Three-dimensional reconstruction result showed that CLFT had significantly higher similarity than CLT (0.43±0.14 vs 0.16±0.06,t =5.090,P＜0.05).Conclusion CLFT could reflect the distribution of radiopharmaceuticals more precisely than CLT,and therefore might have potential in biologic optical imaging.

OBJECTIVETo optimize the protocols for isolation and culture of mesenchymal stem cells from rat bone marrow (BMSCs).

METHODSBMSCs were isolated by adherence to plastic with frequent medium change and reduced trypsinization time. The cell growth curves were drawn and the surface markers of BMSCs were detected by flow cytometry. The cells were induced to differentiate into osteogenic, adipogenic, hepatic and cholic lineages.

RESULTSThe cells isolated using this method were positive for CD29, CD44, and CD90 and negative for the hematopoietic surface markers CD45. The osteogenic and adipogenic differentiation of the BMSCs was verified by alkaline phosphatase staining, Alizarin red staining and Oil red staining. The cell subcultures up to passage 10 maintained capacities of differentiation into osteogenic and adipogenic lineages. The BMSCs induced with sequential addition of growth factors, cytokines and hormones differentiated into cells expressing hepatocyte- and cholangiocyte-specific markers.

CONCLUSIONThe optimized method allows efficient isolation of homogenous populations of MSCs from rat bone marrow, which can be induced into multiple cell lineages.

Animals ; Cell Culture Techniques ; Cell Differentiation ; Cell Proliferation ; Cell Separation ; Flow Cytometry ; Mesenchymal Stromal Cells ; cytology ; Rats