The present study was designed to investigate the regulatory effect of Xenopus oocyte cytoplasm on the functional activity of the injected mammalian erythroid nuclei taken from different developmental stages and the tumor cell nuclei from human HeLa and mouse plasmocytoma (Sp 2/0) cell lines. Experimental results demonstrated that: (1) only 1/3 of the injected erythroid nuclei derived from different physiological status survived and - were induced to become enlarged, accompanied by chromatin dispersion, clear nucleoplasm, and with the ability of incorporation of~3H-uridine for the synthesis of RNA, while most of the injected nuclei in pyknosis or in late differentiated stage were inactivated, stained black and degenerated steadily; (2) almost all the "injected tumor cell nuclei originally in active division of Sp 2/0 and HeLa survived and were activated by showing nuclei enlarged to about 10 to 200 times with fully chromatin dispersion, concomitant clear nucleoplasm and well developed nuclcoli. The state of activation is much more pronounced than that in erythroid nuclei; (3) isoelectrophoretic analysis of the oocytes with transplanted nuclei showed a dark band at pi 6.28 which is corresponding to a homologous component, but other than hemoglobin from rat bone marrow erythrocytes. It is suggested that the gene activities of the injected nuclei were reprogrammed by the oocyte cytoplasm, globin gene originally activated were closed and oocyte selected to open genes that suitable to host genetic state; (4) when injected into Xenopus oocyte with purified rat globin mRNA polyribosomes, it translated efficiently into hemoglobin. The above mentioned results could be concluded that the Xenopus oocyte provided favorable conditions for the translation of purified mRNA polysomes as well as to regulate or reprogram the expression of gones in the injected nuclei. The regulatory effect is closely related to the initial physiological status and the competence of the injected nuclei themselves responsed to oocyte cytoplasm, i.e. the efficiency is much more prominent in originally active proliferative nuclei than those in late or terminal differentiation.

Objective To study the molecular mechanism of medulloblastoma.Methods The cell line with PARP-1 and P53 null mutation was established and characterized.Mouse medulloblastoma cell line derived from PARP-1/P53 double knockout mice was established.We analyzed cell characters after 30 passages,using neuronal cell-specific markers by immunofluorescence.The cells were transfected with pEGFP-C1-Hparp-1 and pEGFP-C1 plasmids,the expression of PARP-1 protein was detected by immunofluorescence stainning and Western blot.Results The cells showed positive immunoactivity for the neuronal-specific markers such as Vimentin,Dcx and ?Ⅲ-Tubulin,and cells were negative for PARP-1 protein.Exogenous PARP-1 expression was visualized by immunofluorescence and Western blot analysis after pEGFP-C1-Hparp-1 transfection.Conclusion Mouse medulloblastoma cell line with defective function for DNA damage recovery has been successfully established,which provides a useful tool for further dissecting the molecular mechanism and pathogenesis of medulloblastoma.

onclusions Both three-dimensional CT and MR images integrated into an CARTO system can be successfully used to perform catheter ablation for AF and there was no difference in registration accuracy between the two groups.

Objective To assess the role of MR myocardial perfusion imaging (MRMPI) in detecting the viabilitive of myocardium in patient with old myocardial infarction (OMI) Methods MRMPI was performed in 47 patients suffering from old myocardial infarction with 1 5 T MR scanner Male 44, female 3, age ranged from 30 to 87 years with a mean of 61 years All patients were imaged during the first pass and delayed phase 5-30 min after injection of Gd DTPA 0 1 mmol/kg at 5 ml/s using IR turbo FLASH sequence Short axis images were acquired during the first pass, and both short axis and long axis images during delayed phase The left ventricular wall on short axis slice was divided into 8 segments A correlative study was carried out in 17 patients with the results of rest and stress 99m Tc SPECT scanning Results In 47 patients of old myocardial infarction, 29(61 7%) showed hypoenhancement during the first pass imaging (the SI was 50 20?7 45 percent of normal segment)and 46(97 9%) revealed delayed hyperenhancement(the SI was 491 0?197 26 percent of normal segment). For delayed hyperenhancement, 10(21 3%) was transmural ,15(31 9%) was nontransmural, and 21(44 7%) mixed, another one was normal 37 segments in 17 patients revealed to be nonviable by rest and stress 99m Tc SPECT, and the MRMPI all showed delayed hyperenhancement 116 viable segments on rest and stress 99m Tc SPECT, and no delayed hyperenhancement in 97 segments (83 6%) on MRMPI With the rest and stress 99m Tc SPECT as a standard of reference the sensitivity and the specificity of MRMPI were 100.0% and 83 6% respectively Conclusion The myocardial viability and nonviability as well as their severity and extent may be effectively evaluated with MRMPI in patients with OMI

Objective To evaluate the feasibility of 320-row volume CT myocardial perfusion imaging (CT-MPI) in detecting myocardial perfusion defect.MethodsFourteen patients with positive single-positron emission computed tomography myocardial perfusion imaging (SPECT-MPI)findings underwent both rest and adenosine stress 320-row volume CT-MPI.Rest and stress CT perfusion images were analyzed by employing dedicated software in 320-row CT workstation.Both SPECT-MPI and CT-MPI were evaluated for fixed and reversible perfusion defects using a 16-segment model (apex was excluded).The sensitivity,specificity of 320-row volume CT-MPI in detecting myocardial perfusion defect were evaluated by taking SPECT-MPI as a reference standard.ResultsBoth rest and stress 320-row volume CT-MPI were successfully performed in all patients.Thirty nine segments with fixed or reversible perfusion defects in all patients were depicted by SPECT-MPI,while 34 perfusion defects in 12 patients were identified by CT-MPI.The sensitivity,specificity of 320-row volume CT-MPI for detection of perfusion defects were 87.2％(34/39),91.4％ ( 169/185 ),respectively.Conclusion320-row volume CT-MPI has high sensitivity and specificity for detection of myocardial perfusion defects.

Objective To evaluate the in vitro effect on tumor cell uptake,tumor imaging and in vivo biodistribution of 99Tcm-epidermal growth factor receptor (EGFR) mRNA antisense PNA probe mediated by cationic liposome.Methods The oligonucleotide with sequence complementary to part of the EGFR mRNA antisense PNA was hybridized in an anti-parallel orientation targeted PNA.PNA hybridization complexes were labeled with 99Tcm by ligand exchange.The assembly of lipofectamine and 99Tcm-labeled heteroduplex was achieved by electrostatic interactions,and the radiolabeled purity was determined by reversedphase HPLC (RP-HPLC).The disparities of cell uptake in SKOV3 cells and the differences of biodistribution and molecular imaging in BALB/c nude mice bearing SKOV3 xenografts between lipofectanine-mediated 99Tcm-EGFR mRNA antisense PNA (group 1) and 99Tcm-EGFR mRNA antisense PNA (group 2) were analyzed.Two-sample t (or t') test and Wilcoxon rank sum test were used for statistical analysis.Results The labeling rates of both group 1 and group 2 were more than 95％ within 6 h.The cell uptake at 1,2,4,6,12,24 h after injection was (28.90±1.12)％,(32.76±1.20)％,(38.20±3.11)％,(41.23±1.60)％,(46.63±1.55)％ and (46.78±2.14)％ in group 1,and was (3.51±0.39)％,(3.90±0.40)％,(4.69±0.18)％,(5.91±0.26)％,(5.30±0.22)％ and (5.39±0.17)％ in group 2 respectively (t'=47.11-58.67,Z=2.80,all P＜0.05).The retention ratios showed significant difference between the two groups (t'=7.25-11.55,Z=2.80,all P＜0.05).The SKOV3 tumor could be visualized in both groups at 1 h post injection but much better visualized in group 1.The T/NT ratios were higher in group 1 at all time points (t =3.96,t'=12.65-14.69,Z=2.83-5.29,all P＜0.05).The T/NT ratios at uptake peak were 5.02 and 3.95,respectively.The probe accumulated mainly in tumor,kidneys and liver.Tumor uptake increased with time ((1.49±0.09) ％ID/g and (2.15±0.21) ％ID/g at 1 h,(3.90±0.65) ％ID/g and (5.00±0.10) ％ID/g at 6 h) after lipofectamine treatment.The ratios of tumor to contralateral muscle were also higher in group 1 (t =11.24,t' =3.96-11.94,all P＜0.05).Conclusions Lipofectamine-mediation can significantly improve the intracellular delivery of radionuclide molecular probe.Lipofectamine-mediated 99Tcm-EGFR mRNA antisense PNA can greatly improve imaging contrast and visualization of EGFR-over-expressing tumors.

Objective To explore the feasibility of delineation of the atherosclerotic plaque in carotid artery using compressed sensing three dimensional motion-sensitized driven equilibrium prepared rapid gradient echo (CS-3D MERGE) technique. Methods Twenty-three patients who underwent carotid endarterectomy (CEA) were enrolled prospectively. In all patients, bilateral carotid arteries were scanned by CS-3D MERGE and contrast-enhanced MR angiography (MRA) simultaneously. Image quality of CS-3D MERGE images was scored. Images from the CS-3D MERGE sequence and contrast-enhanced MRA were used to measure the carotid stenosis, which were divided into four groups:normal group, mild stenosis group, moderate stenosis group, and severe stenosis group. The results were compared between the two methods. And images from the CS-3D MERGE sequence were compared with corresponding histology in identifying major plaque components including lipid rich necrotic core (LRNC), intraplaque hemorrhage (IPH), and calcification (CA). Spearman rank correlation coefficient was used to compare the correlation between the CS-3D MERGE sequence and contrast-enhanced MRA in measuring the carotid stenosis. Agreement was tested comparing images from the CS-3D MERGE sequence with corresponding histology in identifying major plaque components including lipid-rich necrotic core, intraplaque hemorrhage, and calcification. Results Twenty-three CEA patients finished bilateral CS-3D MERGE scanning successfully. Image quality was 3.16±0.25. There was an excellent correlation between CS-3D MERGE and MRA in measuring stenosis (r=0.95, P<0.01). The agreement between CS-3D MERGE and histological results for LRNC detection was 76.2% (16/21). It was less sensitive for IPH detection (71.4%, 15/21). CS-3D MERGE identified all CA accurately (100.0%, 21/21). Sensitivity and specificity were 86.6% (13/15) and 50.0% (3/6) for LRNC, 73.3% (11/15) and 66.6% (4/6) for IPH, 100.0% for CA respectively(16/16, 5/5). Conclusion CS-3D MERGE, a single sequence, can be used to quantify carotid stenosis and plaque components conveniently.

Objective To study the value of dual-source CT(DSCT)in assessing aortic mechanical valve with 3D cardiovascular imaging technique.Methods Thirty-four patients with mechanical aortic valve transplantation were enrolled.Nineteen cases transplanted with On-x valve and 15 cases with St jude valre.CT scan was performed in all 34 patients and MRI scan in 30 patients.The CT imaging quality of On-x valve with St jude valve was compared by two independent samples Wilcoxon rank test.Two independent sampies test was used to compare tlle valve angle in the two kinds of valve and also in the same group.The relative functional index of left ventricle in CT and MR analysis by paired-samples t Test. Results The image quality was dirided into three grades.Six hundred and eighty phases in all 34 patients.which included 391 phases with grade 1,171 phases with grade 2 and 118 phases with grade 3.There were no significant different between two kinds of mechanical valve in image quality(image quality of grade 1:Z=-1.084,P=0.286;grade 2:Z=-0.088,P=0.945;grad 3:Z=-1.045,P=0.319).The mean bileaflet angle of 34 cases was 82.0°±4.4°in completely opening and 34.5°±5.7°in completely closing.The mean radian gradient over openess and closure was 47.5°±7.5°.The radian gradient of St iude group(55.0°±1.8°)was obviously larger than On-x group(41.5°±4.1°)(t=-11.732,P=0.000).But,there were no significant difference between dual-source CT and 1.5 T MR when evaluate the left ventrical fuction,including EF[MR.EF(57.2-1-2.8)%,CT-EF(57.9±2.8)%,f:-0.496,P=0.623],EDV[MR-EDV (121.6±9.1)ml,CT-EDV(132.9±11.2)ml,t=-1.198,P:0.240],ESV[MR-ESV(55.1±6.9)ml,CT-ESV(59.5±7.6)ml,t=-1.094,P=0.283],myocardium mass at ED[MR-Myo.mass (155.5 ±12.6)g,CT-Myo.mass(147.9±11.6)g,t=1.823,P=0.079]and CO[MR-CO(5.7±0.4)ml/min,CT-CO(5.9±0.5)ml/min,t=-3.211,P=0.775].Conclusions Dual source CT with 3D cardiovascular imaging technique is valuable and effective for evaluating aortic mechanical valve.The shape of the whole valve and movement of bileaflet reappears well.With the postprocessing software,it allows evaluating aortic mechanical valve function,reliable measurements of opening and closing leaflet angles and left ventrieal function.

Objective To investigate the feasibility and accuracy of enhanced magnetic resonance pulmonary perfusion imaging(MRPP) in the diagnosis and follow-up of pulmonary embolism(PE). Methods Sixty patients suspected of PE underwent MRPP. Twenty-seven patients also underwent radionuclide perfusion imaging. 22 patients repeated MRPP examination after 3 day to 1 month anticoagulation or thrombolytic therapy. The feasibility and accuracy of MRPP in the diagnosis and follow-up of PE were evaluated according to the transformation rate of signal (TROS), time-signal curve and some parameters of main pulmonary artery(such as peak value of flow,mean flow velocity and flow rate). The t test and rank sum test were used for the statistics. Results MRPP showed a high agreement with radionuclide perfusion imaging. TROS was (2. 86 ± 2. 48 ) vs ( 6. 72 ± 2. 54) ( t = 3. 370, P ＜ 0. 01 ), the peak time was ( 13.98 ±5.60) vs ( 12. 33 ± 3.63 ) s ( t = 3. 930, P ＜ 0. 01 ), the peak value of main pulmonary blood flow was (60.39 ± 15. 17) vs (69.93±13.22) cm/s(t=2.930, P＜0. 01) and mean flow velocity (11.68±5.46) vs ( 13.54 ± 4. 18 ) cm/s ( t = 2. 380, P ＜ 0. 05 ) before and after anticoagulation or thrombolytic therapy. The flow rate per unit was (80. 57 ± 24. 87) vs ( 85.48 ± 11.81 ) ml/s ( t = 0. 86,P ＞ 0. 05 ) . Conclusion MRPP shows a high agreement with radionuclide perfusion imaging and is a useful method for the diagnosis and follow-up of PE.

Objective To compare the protective effect of different dose of penehyclidine hydrochloride (PHC) in rats with myocardial ischemia/reperfusion (I/R) injury.Methods Forty-eight healthy male Wistar rats were randomly divided into six groups (n =8 each):sham group,sham + 1.0 mg/kg PHC group (sham + H-PHC group),I/R group,I/R + 0.1 mg/kg PHC preconditioning group (I/R + L-PHC group),I/R + 0.3 mg/kg PHC preconditioning group (I/R + M-PHC group),and I/R + 1.0 mg/kg PHC preconditioning group (I/R + H-PHC group).I/R injury model was reproduced by ligation followed by release of the coronary artery,and PHC in different dosages was given at 30 minutes before model reproduction.At 3 hours after reperfusion,the left ventricular end-diastolic pressure (LVEDP),left ventricular end-systolic pressure (LVESP),ejection fraction (EF),and fractional shortening (FS) were recorded.The levels of aspertate aminotransferase (AST),MB isoenzyme of creatine kinase (CK-MB),and lactate dehydrogenase (LDH) were determined.The myocardial tissues were harvested for the determination of the area at risk (AAR) and the infarct area (AI),and the percentage of AI/AAR was calculated.The examination of myocardial fiber was performed with electron microscopy.Results Compared with sham and sham + H-PHC groups,LVEDP was increased in I/R groups,LVESP,EF and FS were decreased,and the levels of AST,CK-MB and LDH,as well as the AI/AAR were increased.Compared with I/R group,in pretreatment groups with different doses of PHC,LVEDP was decreased,LVESP,EF and FS were increased,the levels of AST,CK-MB,LDH,and AI/AAR were also decreased,especially in I/R+M-PHC and I/R+H-PHC groups [LVEDP (mmHg,I mmHg =0.133 kPa):11.33± 1.17,9.85± 1.09 vs.15.82 ± 1.79,LVESP (mmHg):98.9 ± 10.6,112.8 ± 10.0 vs.87.8 ± 9.2,EF:0.681 ± 0.074,0.741 ± 0.070 vs.0.569 ± 0.072,FS:(42.4 ± 4.6)％,(46.0 ± 5.1)％ vs.(36.8 ± 3.9)％,AST (U/L):386.97 ± 80.65,298.31 ± 54.88 vs.603.47 ± 173.66,CK-MB (U/L):3.12 ± 0.84,2.88 ± 0.72 vs.7.14 ± 1.54,LDH (U/L):1 784.23 ± 488.49,1 629.37 ± 436.34 vs.2 489.14 ± 460.80,AI/AAR:0.284 ± 0.014,0.223 ± 0.008 vs.0.377 ± 0.011,all P ＜ 0.05].There was significant difference in LVEDP,LVESP,and AI/AAR between I/R + M-PHC group and I/R + H-PHC group (all P ＜ 0.05),and no significant difference in other parameters (all P ＞ 0.05).It was showed by electron microscopic examination that after I/R injury,the myocyte mitochondria membranes were broken,mitochondria were markedly swollen,mitochondrial cristae disappeared;however in I/R+M-PHC and I/R+H-PHC groups,mitochondrial swelling was mild,the capsule was more or less intact,mitochondrial cristae were partly visible,the structure was complete,especially in the group I/R+H-PHC,and the mitochondrial structure was close to normal.Conclusions PHC could protect myocardial from I/R injury.Mid dose of PHC (0.3 mg/kg) and high dose of PHC (1.0 mg/kg) could provide better protective effect than low dose of PHC (0.1 mg/kg),and high dose of PHC is better in effect than the middle dose.