Imaging of Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression with Radiolabeled 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in Liver by Hydrodynamic-based Procedure / 핵의학분자영상

PURPOSE: Hydrodynamic-based procedure is a simple and effective gene delivery method to lead a high gene expression in liver tissue. Non-invasive imaging reporter gene system has been used widely with herpes simplex virus type 1 thymidine kinase (HSV1-tk) and its various substrates. In the present study, we investigated to image the expression of HSV1-tk gene with 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in mouse liver by the hydrodynamicbased procedure. MATERIALS AND METHODS: HSV1-tk or enhanced green fluorescence protein (EGFP) encoded plasmid DNA was transferred into the mouse liver by hydrodynaminc injection. At 24 h post-injection, RT-PCR, biodistribution, fluorescence imaging, nuclear imaging and digital wholebody autoradiography (DWBA) were performed to confirm transferred gene expression. RESULTS: In RT-PCR assay using mRNA from the mouse liver, specific bands of HSV1-tk and EGFP gene were observed in HSV1-tk and EGFP expressing plasmid injected mouse, respectively. Higher uptake of radiolabeled IVDU was exhibited in liver of HSV1-tk gene transferred mouse by biodistribution study. In fluorescence imaging, the liver showed specific fluorescence signal in EGFP gene transferred mouse. Gamma-camera image and DWBA results showed that radiolabeled IVDU was accumulated in the liver of HSV1-tk gene transferred mouse. CONCLUSION: In this study, hydrodynamic-based procedure was effective in liver-specific gene delivery and it could be quantified with molecular imaging methods. Therefore, co-expression of HSV1-tk reporter gene and target gene by hydrodynamic-based procedure is expected to be a useful method for the evaluation of the target gene expression level with radiolabeled IVDU.

Small Animal PET Imaging with 124IFIAU for Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression in a Hepatoma Model / 핵의학분자영상

PURPOSE: The HSV1-tk gene has been extensively studied as a type of reporter gene. In hepatocellular carcinoma (HCC), only a small proportion of patients are eligible for surgical resection and there is limitation in palliative options. Therefore, there is a need for the develoopement of new treatment modalities and gene therapy is a leading candidate. In the present study, we investigated the usefulness of substrate, 2'-fluoro-2'-deoxy-1-beta-D-arabino-furanosyl-5-[124/125I]iodo- uracil ([124/125I]FIAU) as a non-invasive imaging agent for HSV1-tk gene therapy in hepatoma model using small animal PET. MATERIAL AND METHODS: With the Morris hepatoma MCA cell line and MCA-tk cell line which was transduced with the HSV1-tk gene, in vitro uptake and correlation study between [125I]FIAU uptake according to increasing numeric count of percentage of MCA-tk cell were performed. The biodistribution data and small animal PET images with [124I]FIAU were obtained with Balb/c-nude mice bearing both MCA and MCA-tk tumors. RESULTS: Specific accumulation of [125I]FIAU was observed in MCA-tk cells but uptake was low in MCA cells. Uptake in MCA-tk cells was 15 times higher than that of MCA cells at 480 min. [125I]FIAU uptake was linearly correlated (R2=0.964, p=0.01) with increasing percentage of MCA-tk numeric cell count. Biodistribution results showed that [125I]FIAU was mainly excreted via the renal system in the early phase. Ratios of MCA-tk tumor to blood acting were 10, 41, and 641 at 1 h, 4 h, and 24 h post-injection, respectively. The maximum ratio of MCA-tk to MCA tumor was 192.7 at 24 h. Ratios of MCA-tk tumor to liver were 13.8, 66.8, and 588.3 at 1 h, 4 h, and 24 h, respectively. On small aninal PET, [124I]FIAU accumulated in substantial higher levels in MCA-tk tumor and liver than MCA tumor. CONCLUSION: FIAU shows selective accumulation to HSV1-tk expressing hepatoma cell tumors with minimal uptake in normal liver. Therefore, radiolabelled FIAU is expected to be a useful substrate for non-invasive imaging of HSV1-tk gene therapy and therapeutic response monitoring of HCC.

Imaging of Lung Metastasis Tumor Mouse Model using 18FFDG Small Animal PET and CT / 핵의학분자영상

PURPOSE: The purpose of this study is to image metastaic lung melanoma model with optimal pre-conditions for animal handling by using [18F]FDG small animal PET and clinical CT. MATERIALS AND METHODS: The pre-conditions for lung region tumor imaging were 16-22 h fasting and warming temperature at 30 degrees C. Small animal PET image was obtained at 60 min postinjection of 7.4 MBq [18F]FDG and compared pattern of [18F]FDG uptake and glucose standard uptake value (SUVG) of lung region between Ketamine/Xylazine (Ke/Xy) and Isoflurane (Iso) anesthetized group in normal mice. Metastasis tumor mouse model to lung was established by intravenous injection of B16-F10 cells in C57BL/6 mice. In lung metastasis tumor model, [18F]FDG image was obtained and fused with anatomical clinical CT image. RESULTS: Average blood glucose concentration in normal mice were 128.0+/-23.87 and 86.0+/-21.65 mg/dL in Ke/Xy group and Iso group, respectively. Ke/Xy group showed 1.5 fold higher blood glucose concentration than Iso group. Lung to Background ratio (L/B) in SUVG image was 8.6+/-0.48 and 12.1+/-0.63 in Ke/Xy group and Iso group, respectively. In tumor detection in lung region, [18F]FDG image of Iso group was better than that of Ke/Xy group, because of high L/B ratio. Metastatic tumor location in [18F]FDG small animal PET image was confirmed by fusion image using clinical CT. CONCLUSION: Tumor imaging in small animal lung region with [18F]FDG small animal PET should be considered pre-conditions which fasting, warming and an anesthesia during [18F]FDG uptake. Fused imaging with small animal PET and CT image could be useful for the detection of metastatic tumor in lung region.

A Study on Preparation of 3'-18FFluoro-3'-deoxythymidine and Its Biodistribution in 9L Glioma Bearing Rats / 핵의학분자영상

PURPOSE: Several radioisotope-labeled thymidine derivatives such as [11C]thymidine was developed to demonstrate cell proliferation in tumor. But it is difficult to track metabolism with [11C]thymidine due to rapid in vivo degradation and its short physical half-life. 3'-[18F]fluoro-3'-deoxythymidine ([18F]FLT) was reported to have the longer half life of fluorine-18 and the lack of metabolic degradation in vivo. Here, we described the synthesis of the 3'-[18F]fluoro-3'-deoxythymidine ([18F]FLT) and compared with [18F]FET and [18F]FDG in cultured 9L cell and obtained the biodistribution and PET image in 9L tumor bearing rats. MATERIAL AND METHOD: For the synthesis of [18F]FLT, 3-N-tert-butoxycarbonyl-(5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-deoxy-3'-O-(4-nitrobenzenesulfonyl)-beta-D-threopentofuranosyl)thymine was used as a FLT precursor, on which the tert-butyloxycarbonyl group was introduced to protect N3-position and nitrobenzenesulfonyl group. Radiolabeling of nosyl substitued precursor with 18F was performed in acetonitrile at 120 degrees C and deproteced with 0.5 N HCl. The cell uptake was measured in cultured 9L glioma cell. The biodistribution was evaluated in 9L tumor bearing rats after intravenous injection at 10 min, 30 min, 60 min and 120 min and obtained PET image 60 minutes after injection. RESULTS: The radiochemical yield was about 20-30% and radiochemical purity was more than 95% after HPLC purification. Cellular uptake of [18F]FLT was increased as time elapsed. At 120 min post-injection, the ratios of tumor/blood, tumor/muscle and tumor/brain were 1.61+/-0.34, 1.70+/-0.30 and 9.33+/-2.22, respectively. The 9L tumor was well visualized at 60 min post injection in PET image. CONCLUSION: The uptake of [18F]FLT in tumor was higher than in normal brain and PET image of [18F]FLT was acceptable. These results suggest the possibility of [18F]FLT as an imaging agent for brain tumor.

Synthesis and Preliminary Evaluation of 9-(4-18FFluoro-3-hydroxymethylbutyl) Guanine (18FFHBG) in HSV1-tk Gene Transduced Hepatoma Cell / 핵의학분자영상

PURPOSE: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), 9-(4-[18F]fluoro-3-hydroxymethylbutyl)guanine ([18F]FHBG) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. MATERIALS AND METHODS: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with K[18F]/K2.2.2. in acetonitrile using N2-monomethoxytrityl-9-[4-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of [18F]FHBG were performed, and was analyzed correlation between [18F]FHBG uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. RESULTS: [18F]FHBG was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiochemical yield was about 20-25% (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 GBq/micro mol. Specific accumulation of [18F]FHBG was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked [18F]FHBG was retained inside of cells. The uptake of [18F]FHBG was showed a highly significant linear correlation (R2=0.995) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. CONCLUSION: [18F]FHBG appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.

In Vivo Nuclear Imaging of Apoptosis / 대한핵의학회잡지

Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis is a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about 10 (-9) M for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with 99mTc by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

In Vitro Uptakes of Radiolabeled IVDU and IVFRU in Herpes Simplex Virus Type-1 Thymidine Kinase (HSV1-tk) Gene Transduced Morris Hepatoma Cell Line / 대한핵의학회잡지

PURPOSE: The herpes simplex virus type 1 thymidine kinase gene (HSV1-tk) is an attractive candidate as a reporter gene in noninvasive reporter gene monitoring system. The HSV1-tk gene was chosen as a reporter gene, because it has been extensively studied, and there are appropriate reporter probes, substrates of HSV1-tk gene product, to apply for HSV1-tk gene imaging. We used radiolabeled 5-iodovinyl-2'-deoxyuridine (IVDU) and 5-Iodovinyl-2'-fluoro-2'-deoxyuridine (IVFRU) as reporter probes for HSV1-tk gene monitoring system. MATERIALS AND METHODS: We prepared HSV1-tk gene transduced Morris hepatoma cell line using retroviral vector, MOLTEN containing HSV1-tk gene. And we confirmed the HSV1-tk gene expression by Northern blotting and Western blotting. We compared in vitro uptakes of radioiodinated IVDU and IVFRU to monitor HSV1-tk gene expression in Morris hepatoma cell line (MCA) and HSV1-tk gene tranduced MCA (MCA-tk) cells until 480 minutes. We also performed correlation analysis between percentage of HSV1-tk gene tranduced MCA cell % (MCA-tk%) and uptakes of radiolabeled IVDU or IVFRU. RESULTS: MCA-tk cell expressed HSV1-tk mRNA and HSV1-TK protein. Two compounds showed minimal uptake in MCA, but increased uptake was observed in MCA-tk. IVDU showed 4-fold higher accumulation than IVFRU at 480 min in MCA-tk (p 0.96) with increasing MCA-tk%. CONCLUSION: The radiolabeld IVDU and IVFRU showed higher specific accumulation in retrovirally HSV1-tk gene transfected Morris hepatoma cell line. Both IVDU and IVFRU could be used as good substrates for evaluation of HSV1-tk gene expression.

Radioimmunoassay for Determination of Serum Macrophage Migration Inhibitory Factor / 대한핵의학회잡지

PURPOSE: There has been a renewal of interest in Macrophage migration inhibitory factor (MIF), especially correlation in pathogenesis of sepsis by many infectious diseases and in regulation of host inflammatory and immune response. We developed immunoradiometric assay (IRMA) to determine serum human MIF concentration. MATERIALS AND METHODS: The IRMA system utilizes solid phase bound monoclonal anti-recombinant human MIF (rhMIF) antibody as a capture antibody, biotinylated polyclonal anti-rhMIF antibody as a detector antibody. We applied with rhMIF that concentration of standard solutions increased from 0 ng/ml to 100 ng/ml. We used 125I-streptavidin (SA) as radiotracer to determination of rhMIF concentration. Streptavidin was labeled with 125I by Chloramine-T method and 125I-SA was purified by ultracentrifugation. 125I-SA stability was evaluated by ITLC analysis at 4 degrees C and room temperatures until 60days. To validate IRMA system for MIF, we experimented intra-assay and inter-assay coefficients of variation, recovery test and dilution test. RESULTS: Radiolabeling yield of 125I-SA was 87% and purified 125I-SA retained above 99% radiochemical purity. 125I-SA showed above 93% stability in 4 degrees C until 60days that it is good for immunoradiometric assay as radiotracer. Plotted standard dose response curve showed that increased concentration of rhMIF linearly correlated (R2=0.99) with bound radioactivity of 125I-SA. The highest intra- and inter-assay coefficients of variation were 5.5% and 7.6%, respectively. The average of recovery of MIF in samples was 102%. In dilution test, linear response curves were obtained (R2=0.97). CONCLUSION: Radioimmunoassay using 125I-SA as radiotracer thought to be useful for the determination of serum MIF concentration, and further, its data will be used to evaluate the correlation between clinical significance and serum MIF concentration in patients with various inflammatory diseases.

Preparation of 125I-Iodotyraminehemisuccinyltaxol ( 125ITHT ) for Competitive Taxol Radioimmunoassay / 대한핵의학회잡지

No abstract available.

Studies on Scintillation Proximity Assay for the mesurement of alpha - hCG / 대한핵의학회잡지

No abstract available.

Preparation of 99mTc-HYNIC-PEG-liposomes for Imaging of the Focal Sites of Infection / 대한핵의학회잡지

No abstract available.

Preparation of 99mTc-HYNIC-PEG-liposomes for Imaging of the Focal Sites of Infection / 대한핵의학회잡지

No abstract available.

In Vivo Image and Biodistribution of 123I-15-(p-iodophenyl)-3-R , S - methylpentadecanoic acid ( BMIPP ) in Liposarcoma Bearing Nude Mice / 대한핵의학회잡지

No abstract available.

A Clinical Analysis of Treatment of Cervical Fracture and Dislocation

Recently, the authors experienced the thirty-one cases of cervical fracture and dislocation. Among them, nineteen cases underwent surgical treatment and remained conservative treatment. There are three ways in operation ; 1) anterior approach(Cloward, Smith-Robinson method). 2) posterior approach. 3) combined approach(modified Smith-Robinson and posterior fusion). We did a combined approach and the results were excellent.

Two Cases of Spontaneously Absorbed Chronic Subdural Hematoma

The authors managed forty cases of chronic subdural hematoma which were diagnosed by carotid angiography and computerized tomographic scanning. Within fortieth-day after onset, only two cases are absorbed without any specific treatment and clearly.