RESUMO
Objective The purpose of this study is to construct eukaryotic gene vector of herpes simplex virus type 1 thymidine kinase(HSV1-tk)and to observe the expression of HSV1-tk in lung adenocarcinoma AGZY cell line.Methods The full length HSV1-tk gene was amplified by PCR from plasmid pHSV 106 and was inserted into pMD18-T.The recombinant plasmid was recombined with eukaryotic vector plRES 2-EGFP u-sing gene recombinant technique .HSV1 -tk was transfected into adenocarcinoma AGZY cell line with Lipo-fectamineTM 2 000.Fluorescence microscopy was used to detect the transfection and expression of HSV 1-tk.RT-PCR was used to detect the mRNA levels of HSV 1-tk.The cell proliferation was measured by MTT assay .Re-sults A length of 1 130 bp gene sequence was obtained by PCR .The expressions of HSV 1-tk at mRNA and protein levels were displayed by RT -PCR and Western blot .MTT analysis showed that there were no significant changes cell survival on after transfection .Conclusion The eukaryotic expression vector of HSV 1 -tk report gene is successfully constructed and HSV 1-tk is effectively expressed in transfected AGZY cells .
RESUMO
Objective The purpose of the present study is to compare the pharmacokinetic and biodistribution properties of 99Tcm N-mercaptopyridine-N-oxide (99 Tcm N-MPO) with 99 Tcm-sestamibi (99 Tcm-MIBI) in normal dogs, and to investigate the potential of 99TcmN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Twelve healthy mongrel dogs were injected intravenously with 99TcmN-MPO (n = 6) or 99Tcm-MIBI (n = 6). Tracer kinetics in body fluids were determined by collecting blood of 1 ml via a femoral vein catheter at 30 s, 1,2,3,4,5, 10, 20, 30, 40, 60and 90 min post-injection (p. i.). The collected blood samples were weighed and counted for radioactivity in a γ-counter. Anterior and posterior planar γ-camera images were collected at 10, 20, 30, 60, 90, and 120 min after injection, with organ uptake quantified by region-of-interest (ROIs) analysis. For comparison, 99Tcm-MIBI was also evaluated in the same twelve dogs. Canine infarct models were set up by micro-invasive interventional embolization. SPECT images in the canine infarct model were collected 24 hours after myocardial infarction at 30 min and 60 min after the administration of 99Tcm N-MPO (n = 5) or 99Tcm-MIBI (n = 5). Results Both of 99Tcm N-MPO and 99Tcm-M1BI had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min [99TcmN-MPO: (35. 77 ± 6. 31)% ID/mg ,99Tcm-MIBI (34. 46 ± 6. 83) % ID/mg] and less than 5% at 30 min p. i. [99Tcm N-MPO(3. 11 ± 1.44) % ID/mg,99Tcm-MIBI (2.93 ±0. 39)% ID/mg] . After injection, 99TcmN-MPO showed significant accumulation in the myocardium and prolonged retention. This rapid liver clearance of 99TcmN-MPO led to favorable heart-to-liver ratios, reaching values of 0. 54 ±0. 06 at 10 min, 1.02 ±0. 06 at 30 min, and 1.38 ±0. 06 at 60 min p. i.In contrast, the heart/liver ratio of 99Tcm-MIBI remained low at all time points (0. 46 ± 0. 03 at 10 min,0. 63 ±0. 03 at 30 min, and 0. 62 ± 0. 12 at 60 min p. i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of 99TcmN-MPO, but not 99Tcm-MIBI. Conclusion The combination of high heart uptake and rapid liver clearance makes 99TcmN-MPO a promising new radiotracer for myocardial perfusion imaging.