ABSTRACT
Objective To synthesize 99Tcm labeled VEGF fragment (VEGF125-136) and evaluate its biodistribution and imaging in the nude mice bearing human osteosarcoma,in order to find a probe to improve the early diagnosis and targeted therapy of osteosarcoma.Methods VEGF125-136 was synthesized by conventional solid phase synthesis method,and directly coupled with MAG3 to form MAG3-VEGF125-136,then MAG3-VEGF125-136 was labeled with 99Tcm.The osteosarcoma bearing nude mice were randomly divided into four groups by random number table and studied for 99Tcm-MAG3-VEGF125-136 distribution at 0.5,1,2,4 h,respectively.The other 10 osteosarcoma bearing nude mices were divided into the experimental group and competitive inhibition group,and underwent radionuclide imaging.The T/NT ratio was calculated.Data were analyzed using two-sample t test.Results The radioactive labeling rate was greater than 95％,radiochemical purity was still greater than 85％ after 12 h in room temperature.The 99Tcm-MAG3-VEGF125-136 was cleared fast in blood and mainly excreted through the kidneys and liver.Tumor uptake of 99Tcm-MAG3-VEGF125-136 was highest at 1 h with (0.28±0.02) ％ID/g.The T/NT ratios of experimental group at 0.5,1,2,4 h were 1.07±0.10,3.10±0.19,2.63±0.14,1.90±0.09,respectively.In competitive inhibition group,no obvious radioactivity concentration was observed in tumors.The T/NT ratios were 0.99± 0.05,1.06± 0.06,0.98±0.03,0.97±0.03 at 0.5,1,2,4 h respectively.The T/NT ratios were significantly different between the two groups at 1,2,4 h (t=22.52,26.36 and 22.31,all P＜0.05),but no significant difference was observed at 0.5 h (t =1.44,P＞0.05).Conclusion 99Tcm-MAG3-VEGF125-136 has high labeling efficacy,good stability and high specificity to osteosarcoma.It can be used as an agent for early diagnosis and therapy monitoring in osteosarcoma.
ABSTRACT
Amyotrophic lateral sclerosis (ALS),a neurodegenerative disorder,is subtle in disease onset,difficult to diagnose,and fast-growing at progression.There.are at present little specific neurological imaging characteristics of ALS.Functional brain imaging techniques,such as SPECT and PET,were the early tools for investigation of ALS.The application of pixel-based analysis software (such as SPM) renders research in this area more convenient and objective.In recent years,improvement in brain receptor PET imaging has demonstrated its important value in the early diagnosis of ALS and evaluation of cognitive impairment.
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Objective To investigate the usefulness of 99Tcm-MDP whole body bone scan in bone malignant fibrous histiocytoma (BMFH).Methods Fifteen patients (11 males,4 females,age ranged from 23 to 60 years,average age (50.4±12.8) years) who had documented BMFH and underwent 99Tcm-MDP whole body bone scan were retrospectively analyzed.The appearance of increased uptake,decreased uptake or defect in radioactivity on bone was considered as positive.The typical scintigraphic manifestations of BMFH were summarized and compared to other radiological imaging data.Results All 15 patients showed positive results.The lesions involved femoral in 10 cases(66.7％),46.7％(7/15) of which was distal femur.The lesions also involved sacrum,tibia,humerus,radius each in 1 case and multiple lesions in 1 case.Among 27 lesions found,63.0％ (17/27) showed strong increased radioactivity together with reduced or defect area and 37.0％ (10/27) showed strong increased radioactivity only.X-ray found 20 lesions.Twelve cases underwent CT and 7 cases underwent MRI.Abnormal spots showed on CT and MRI were also positive on the whole body bone scan.Conclusions The most common site of BMFH is femur,especially distal femur.BMFH lesions are presented as strong increased radioactivity together with sparse and defect area on bone scan.The whole body bone scan may be an auxiliary examination to evaluate whether there are multiple bone lesions and bone metastasis.