ABSTRACT
Objective To explore the value of 3‐dimensional volumetric diagnosis system in quantitative measurement of pulmona‐ry lobar volumetry using a 64 row MDCT .Methods Seventy‐seven adult volunteers were scanned twice on a 64 row MDCT at the end of the maximum inspiratory and maximum expiratory end respectively .On a volumetric computer‐aided diagnosis system ,the en‐tire lung was semiautomatically separated into 5 anatomy lobes including the right upper lobe ,right middle lobe ,right lower lobe ,left upper lobe ,and left lower lobe .Each lobar volume was measured .Results The lung volume of left upper lobe ,right lower lobe ,left lower lobe ,right upper lobe ,right middle lobe in male volunteers were 1 303 .90 mL and 938 .31 mL ,1 276 .90 mL and 737 .69 mL , 1 204 .47 mL and 678 .67 mL ,1 048 .49 mL and 754 .83 mL ,519 .53 mL and 407 .86 mL at the end of the inspiratory and expiratory respectively .The lung volume of left upper lobe ,right lower lobe ,left lower lobe ,right upper lobe ,right middle lobe in female volun‐teers were 915 .78 mL and 666 .23 mL ,913 .87 mL and 576 .62 mL ,822 .17 mL and 509 .30 mL ,734 .20 mL and 530 .23 mL ,389 .13 mL and 316 .70 mL at the end of the inspiratory and expiratory respectively .The values of each lobe volume between the full inspiration phase and expiration phase group showed significant difference the same sex group (P<0 .05) .The values of each lobe volume in the man group were significantly larger than those of female group in both respiratory phase (P<0 .05) .Of the D‐value in the each lobe volume in 5 anatomy lobe at full inspiration phase and expiration phase in both sex group ,both of the lower lobes were the largest , followed by the left upper lobe ,right upper lobe and right middle lobe .The D‐value in the each lobe volume at full inspiration phase and expiration phase in the man group were significantly larger than those of female group .Conclusion Three‐dimensional volumet‐ric diagnosis system and 64 row MDCT images can be used to assess the volume of each lung lobe .
ABSTRACT
Objective To prepare the 99Tcm-labeled human epidermal growth factor receptor type 2 (HER2) affibody molecule ZHER2:342 and evaluate its receptor binding specificity in vitro.Methods The molecular ZHERa:342 was labeled with 99Tcm using the ligand exchange method.The labeling efficiency and radiochemical purity were measured by HPLC.The major factors,such as the mass of SnC12 and NaOH and reaction time were analyzed,and the optimal method was summarized.Cell binding kinetics and cellular retention of the probe were investigated in HER2-expressing SKOV-3 cells and MDA-MB-231 cells with low HER2 expression respectively.HER2 binding specificity of 99Tcm-ZHER2:342 was analyzed by a pre-injection of excess unlabeled ZHER2:342 to saturate HER2 receptors.One-way analysis of variance and two-sample t test were used.Results The optimal labeling procedure was as follows:5 μg (1 g/L) of ZHER2:342 was mixed with 5 μg of NaOH (1 g/L),then 8.8 μg SnC12(1 g/L,solution) was added,followed by 150 μl (37 MBq) 99TcmO4-solution,and finally the mixture was slightly vortexed and incubated for 1 h at room temperature.99TcmZHER2:342 was stable in vitro with a high labeling efficiency of (98.10± 1.73)％.The radiochemical purity was ＞ 98％,and was more than 85％ after the incubation for 24 h in saline and fresh human serum.The cell binding of 99Tcm-ZHER2:342 with HER2-expressing SKOV-3 cells gradually increased over time with a peak of (9.95± 1.02)％ at 6 h.The binding of 99Tcm-ZHER2:342 in SKOV-3 cells was significantly higher than that in MDA-MB-231 cells at every time point (5.68-9.88 vs 0.56-2.11 ; t:from-34.50 to-13.14,all P＜0.01).The labeled molecular probe retained the capacity to bind specifically to HER2-expressing SKOV-3 cells since the cell binding decreased from (9.95 ± 1.02) ％ to (2.11 ±0.27) ％ after receptor saturation (t =-13.14,P＜0.01).Conclusions 99Tcm-ZHER2:342 has a high labeling efficiency,good stability and optimal binding specificity.These characteristics enable it to be a promising molecular probe for HER2-targeting imaging.
ABSTRACT
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.