| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
Biodistribution analysis and in-vivo contrast enhanced MR imaging were done on nude mice bearing a human pancreas cancer (panc-1) of 1-2 cm in diameter. Biodistribution analysis was done using 38 mice according to a timetable, I.e. pre-contrast, 5 min, 2 hrs and 24 hrs after the I.v, -either of HOP-9P (0.1mmol/kg) or HOP-8P (0.1mmol/kg). Mn concentrations in the blood, tumor, muscle, liver, kidneys and pancreas were measured with optical emission spectrometer. MRI was performed on a 3.0 T imager with a head coil using 7 nude mice. Coronal T1-weighted spin echo images (TR/TE=600/14) were acquired before and 2 hours and 24 hours after I.v. injection of HOP-9P (0.1mmol/kg). Mean signal intensities of the tumor and a standard phantom (1 mM CuSO4) were measured and the signal intensity ratios (SIR) were calculated. After the imaging, animals were sacrificed and frozen at -20℃ and sliced, fixed and stained with H&E.
The tissue concentration of Mn in the tumor showed nine-fold increase at 2 hrs post injection of HOP-9P. Tumor/pancreas tissue concentraion was also highest at 2 hours post-injection with mean value^^+__-SD of 0.86^^+__-0.66 as compared to precontrast value of 0.18^^+__-01.6 (p<0.05). Biodistribution data with HOP-8P showed similar trend, but less specificity to the tumor.
Since the biodistribution data of HOP-9P seemed to be more promising, in-vivo MR imaging was done with HOP-9P. The MR images demonstrated progressive and sustained enhancement of the tumor until 24 hrs (p<0.05) after HOP-9P administration (precontrast ; 0.18^^+__-0.01 (mean^^+__-SE), 30min ; 0.21 ^^+__-0.01, 2 hrs ; 0.22^^+__-0.01 and 24 hrs ; 0.23^^+__-0.01).
Imaging and Histological correlation showed that the contrast media can enhance both viable and necrotic portions of the tumor.
Our data suggest HOP-9P may be a promising contrast media to detect pancreatic cancer.
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