RESUMO
Purpose To explore whether potassium perchlorate shall be taken orally to occlude gastric mucosa before taking 99Tcm-3PRGD2 SPECT/CT gastric image,and to provide theoretical evidence for clinical application.Material and Methods Eighteen adult male Wistar rats were divided into three groups randomly:low dose group of potassium perchlorate (36 mg/kg),high dose group (72 mg/kg) and normal saline control group,with six rats in each group.All rats were conducted with gavage of 1 ml/100 g respectively and,one hour later,injected with 99Tcm-3PRGD2 intravenously to rat tail.Then 99Tcm-3PRGD2 gastric image was taken two hours later.The same film reader carried out audio analysis of the image and then gastric and radioactivity ratio (T/N) on the lung of the same side were analyzed.Results Preparation of 99Tcm-3PRGD2 was simple and radiochemical purity of final products was (98.90±0.70)％.Rat weights in high dose group of potassium perchlorate,low dose group and control group were (479.7t21.5) g,(481.0± 17.6) g and (478.5± 16.5) g,respectively.The differences were of no statistical significance (F=0.027,P＞0.05).T/N values in rat stomach area were 1.2219±0.0165,1.2204±0.0167 and 1.2186±0.0175,respectively.The differences were of no statistical significance (F=0.055,P＞0.05).Conclusion Preparation of 99Tcm-3PRGD2 is simple and radiochemical purity is high.There is great possibility of no need to take potassium perchlorate orally to occlude gastric mucosa when taking 99Tcm-3PRGD2 SPECT/CT image (especially when the radiochemical purity of final products is over 98％),making it convenient in clinical promotion and utilization.
RESUMO
BACKGROUND: Embryonic stem cells fESCs) develop from early blastular inner cell mass.Under proper condition,ESCs can maintain undifferentiated state in vitro,normal diploid nuclear type,and proliferative potential.In addition,ESCs possess multi-directional differentiation capacity and can differentiate into all sorts of cells of three germ layers. OBJECTIVE: To investigate the feasibility of directed differentiation of ESCs towards thyroid cells in vitro as well as related molecular expression. DESIGN,TIME AND SETTING: A cell-based observational experiment was performed at the Bank of Cord Blood,Second Hospital Affiliated to Sun Yat-sen University between January 2004 and December 2006.MATERIALS: Balb/c pregnant mice at pregnancy 12.5-14.5 days were used for preparation of embryonic fibroblast feeder layer.E14 mouse embryonic stem cell (ESC) strains were gifted by professor Xu from Harvard University.METHODS: Murine El4 ESCs were cultured in methylcellulose semisolid medium to form embryoid bodies (Ebs).These Ebs were transferred for further inductive culture with the stepwise addition of growth factors- thyrotropin (TSH),insulin and kalium iodidum (KI).The cultured thyroid cells of adult Kunming mice were taken as positive control.MAIN OUTCOME MEASURES: ①Cellular morphological change in the process of differentiation.② Detection of expression levels of TSHR,PAX8,TTF-2,and TIF-1 by immunofluorescence assay.③ Detection of expression levels of TSHR,PAX8,NIS,TPO,and Tg by reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: The differentiated cells had clear boundary,exhibiting round,oval,shuttle-shaped,or polygon adhesive growth.On day 6 of inductive ifferentiation,the differentiated cells showed the expression of PAX8,NIS,TPO,Tg,and TSHR,the specific gene of thyroid ceils.On day 8 of inductive differentiation,the expression of TSHR,TIF-1,PAX8,and TIF-2 was detectable in the differentiated cells with morphous similar to thyroid cells.CONCLUSION: ESCs can differentiate towards thyroid cells under given inductive conditions.