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June-Key Chung

Publications and source records attributed to June-Key Chung.

At least 37 records · Page 2Linked to original sources
PubMed2005

Effect of ginseng saponins on enhanced dopaminergic transmission and locomotor hyperactivity induced by nicotine.

Several studies have shown that behavioral hyperactivity induced by psychomotor stimulants is prevented by ginseng saponins. In an attempt to investigate whether the effect of ginseng saponins is through their inhibitory action on the enhanced dopaminergic transmission by psychomotor stimulants, we examined the effects of ginseng total saponin (GTS) presynaptically on nicotine-induced dopamine (DA) release in the striatum of freely moving rats using in vivo microdialysis technique and postsynaptically on the in vitro and in vivo binding of [3H]raclopride to DA D2 receptors. Also, we examined the effects of GTS on nicotine-induced locomotor hyperactivity and on nicotine-induced Fos protein expression in the nucleus accumbens and striatum. Systemic pretreatment with GTS (100 and 400 mg/kg, intraperitoneally (i.p.)) resulted in a dose-dependent inhibition of locomotor hyperactivity induced by nicotine. GTS decreased nicotine-induced DA release in the striatum in a dose-dependent manner. However, GTS had no effects on resting levels of locomotor activity and extracellular DA in the striatum. GTS inhibited the in vitro binding of [3H]raclopride to rat striatal membranes with an IC50 of 5.14+/-1.09 microM. High doses of GTS (400 and 800 mg/kg, i.p.) resulted in decreases in the in vivo binding of [3H]raclopride in the striatum. GTS decreased nicotine-induced Fos protein expression in the nucleus accumbens and striatum, reflecting the inhibition by GTS of nicotine-induced enhancement of dopaminergic transmission. The results of the present study suggest that GTS acts not only on dopaminergic neurons directly or indirectly to prevent nicotine-induced DA release but also postsynaptically by binding to DA D2 receptors. This may explain the blocking effect of GTS on behavioral activation induced by nicotine and conceivably by other psychostimulants. Our data raise the possibility that GTS, by attenuating nicotine-induced enhancement of dopaminergic transmission, may prove to be a useful therapeutic agent for nicotine addiction and warrant further investigation on its effect on nicotine's rewarding property.

Animals↗
PubMed2005

Evaluation of immediate post-stress wall motion on adenosine stress/rest thallium-201 gated myocardial SPECT.

As early as 10 min after adenosine stress, immediate post-stress wall motion can be evaluated on adenosine stress/rest Tl-201 gated myocardial SPECT. To widen the applications of Tl-201 in gated SPECT, we investigated the reproducibility of LV parameters (EF, EDV, and ESV), and the diagnostic competency of immediate post-stress wall motion evaluations obtained by adenosine stress/rest Tl-201 gated myocardial SPECT. Myocardial perfusion and wall motion were evaluated using a 5-point scoring system in 20-segment model using Cedas automatic gated software (AutoQUANT 4.3.1). The reproducibilities of LV parameters were examined through repeated acquisition (n=31). Diagnostic competency was evaluated vs. coronary angiography, and multivariate logistic regression analysis was used to determine whether stress abnormal perfusion (SSSp), stress abnormal wall motion (SSSwm), or reversible abnormal wall motion (SDSwm) predict coronary stenosis (>70%) (n=60). Two standard deviations for immediate post-stress wall motion were smaller than those for rest at EF (8.6 vs. 10.7%) and ESV (6.0 ml vs 8.4 ml). Univariate logistic regression analysis identified SSSp (p=0.006), SSSwm (p=0.016), and SDSwm (p=0.020) are significant predictors, but only SSSp (p=0.013) and SDSwm (p=0.039) were found to be significant by multivariate analysis. In addition, SSSwm or SDSwm were able to find undetected coronary artery disease in 54.5% (6/11) of patients with normal perfusion. We conclude that Tl-201 can be successfully applied to gated SPECT for immediate post-stress wall motion evaluation, and that reversible wall motion abnormality on adenosine stress/rest Tl-201 gated myocardial SPECT is an independent predictor of significant coronary artery disease.

Adenosine↗
PubMed2005

Voxel-based statistical analysis of cerebral glucose metabolism in the rat cortical deafness model by 3D reconstruction of brain from autoradiographic images.

PURPOSE: Animal models of cortical deafness are essential for investigation of the cerebral glucose metabolism in congenital or prelingual deafness. Autoradiographic imaging is mainly used to assess the cerebral glucose metabolism in rodents. In this study, procedures for the 3D voxel-based statistical analysis of autoradiographic data were established to enable investigations of the within-modal and cross-modal plasticity through entire areas of the brain of sensory-deprived animals without lumping together heterogeneous subregions within each brain structure into a large region of interest. METHODS: Thirteen 2-[1-(14)C]-deoxy-D: -glucose autoradiographic images were acquired from six deaf and seven age-matched normal rats (age 6-10 weeks). The deafness was induced by surgical ablation. For the 3D voxel-based statistical analysis, brain slices were extracted semiautomatically from the autoradiographic images, which contained the coronal sections of the brain, and were stacked into 3D volume data. Using principal axes matching and mutual information maximization algorithms, the adjacent coronal sections were co-registered using a rigid body transformation, and all sections were realigned to the first section. A study-specific template was composed and the realigned images were spatially normalized onto the template. Following count normalization, voxel-wise t tests were performed to reveal the areas with significant differences in cerebral glucose metabolism between the deaf and the control rats. RESULTS: Continuous and clear edges were detected in each image after registration between the coronal sections, and the internal and external landmarks extracted from the spatially normalized images were well matched, demonstrating the reliability of the spatial processing procedures. Voxel-wise t tests showed that the glucose metabolism in the bilateral auditory cortices of the deaf rats was significantly (P<0.001) lower than that in the controls. There was no significantly reduced metabolism in any other area, and no area showed a significant increase in metabolism in the deaf rats with the same threshold, demonstrating the high localization accuracy and specificity of the method developed in this study. CONCLUSION: This study established new procedures for the 3D reconstruction and voxel-based analysis of autoradiographic data which will be useful for examining the cerebral glucose metabolism in a rat cortical deafness model.

Algorithms↗
PubMed2005

Visualization of endogenous p53-mediated transcription in vivo using sodium iodide symporter.

PURPOSE: To develop a gamma camera imaging method for the determination of endogenous gene expression, we evaluated the expression of endogenous p53 gene using human sodium iodide symporter (hNIS) gene as reporter. EXPERIMENTAL DESIGN: We constructed cis-p53RE-hNIS reporter vector placed under control of an artificial enhancer (p53RE). Moreover, we transfected it into human hepatoma cell line SK-Hep1 by liposome. Geneticin was used for the selection of stable transfectant (SK-Hep1p53NIS). To evaluate the function of hNIS, the inhibition study was examined with 1 mmol/L potassium perchlorate. After treatment of Adriamycin with serial dose for 24 hours, we measured the uptake of 125I and did Western blot analysis to evaluate expression of p53 protein. Tumor xenografts were produced in nude mice by s.c. injection of SK-Hep1p53NIS cells. After 7 days, scintigraphic images of nude mice before and after Adriamycin treatment were obtained using [99mTc]-pertechnetate. RESULTS: In the SK-Hep1p53NIS cells, Adriamycin-treated cells accumulated up to three times higher than did nontreated cells. Potassium perchlorate inhibited completely the uptake of 125I. As Adriamycin dose increased, radioiodide uptake was significantly correlated with activated p53 as well as total p53 protein level. When Adriamycin (2 mg/kg) was treated in the same mice, a significantly higher uptake of [99mTc]-pertechnetate was observed in SK-Hep1p53NIS xenografts compared with nontreated xenografts (P < 0.05, unpaired t test). CONCLUSIONS: These results suggest that p53 expression level can be monitored by NIS gene expression using cis-p53RE-hNIS system in vitro and in vivo.

Animals↗
PubMed2005

Regional cerebral blood flow in children with attention deficit hyperactivity disorder: comparison before and after methylphenidate treatment.

Differences in brain activity of children with attention deficit hyperactivity disorder (ADHD) have been compared to normal healthy controls, suggesting neural correlates of cognitive/behavioral symptoms. Symptoms are improved with methylphenidate treatment but limited sources can be cited to show how brain activity in ADHD is altered after pharmacologic treatment. We investigated how long-term oral medication of methylphenidate affects the resting regional cerebral blood flow (rCBF) in ADHD children, using single photon emission computerized tomography (SPECT). rCBF was decreased in the orbitofrontal cortex and middle temporal gyrus in the right hemisphere whereas it was increased in the dorsomedial prefrontal and somatosensory area bilaterally in drug-naive ADHD children compared to control child subjects. After treatment with methylphenidate, the extent of hyperperfusion in the somatosensory area was reduced and significant reduction of rCBF was found in the right striatum for the first time. Methylphenidate treatment also resulted in rCBF increase in superior prefrontal and reduction in ventral higher visual areas bilaterally. The results indicated that improving ADHD symptom after methylphenidate is associated with normalization of abnormally reduced orbitofrontal activity and abnormally increased somatosensory cortical activity. These changes were accompanied with reduced striatum activity lower than that of normal controls. These changes might be associated with improving ADHD to control attention and motor response to irrelevant environmental stimuli after methylphenidate treatment.

Attention Deficit Disorder with Hyperactivity↗
PubMed2005

Correlation between serum CEA level and metabolic volume as determined by FDG PET in postoperative patients with recurrent colorectal cancer.

To determine the correlation between serum CEA level and the metabolic volume by FDG PET in postoperative patients with recurrent colorectal cancer, FDG PET was performed in 29 consecutive patients with recurrent or metastatic colorectal cancer whose CEA levels were higher than 5 ng/ml. A whole body emission scan was performed 60 minutes after injecting 370-555 MBq of F-18 FDG. "PET volume" and "PET metabolic volume" of tumors were measured on FDG PET images. Based on an isocontour plot of tumor mass at 2.5 SUV (standardized uptake value), the metabolically active tumor "PET volume" was calculated. "PET metabolic volume" was obtained by multiplying the "PET volume" by the mean SUV of the tumor. All recurrent or metastatic lesions were single or multiple lesions of measurable size (axial diameter > 1 cm, minimum "PET volume" 3.5 cm3), and were verified by operation or by other imaging modalities (CT or MRI). There was a linear associations between "PET volume" and serum CEA level. Further regression analysis by least squares showed a highly significant model with an equation of volume = 41.2 + 0.471 x CEA (r2 = 0.629). However, no such association was found between "PET metabolic volume" and serum CEA level according to the residual normality test. In conclusion, "PET volume" measured by FDG PET and serum CEA level in colorectal cancer are significantly correlated. Tumor volume determined by FDG PET can be used as an effective marker of tumor burden in postoperative patients with colorectal carcinoma.

Biomarkers, Tumor↗
PubMed2005

Development and applications of a software for Functional Image Registration (FIRE).

Image registration with anatomical modalities, such as CT and MRI, facilitates the anatomical identification and localization in the interpretation of nuclear medicine images that lack anatomical information. The implementation of Functional Image Registration (FIRE), an operating system (OS) and platform independent multimodal image registration software is reported. In order to register the images without an operator's interaction, several automatic algorithms were implemented. These include principal axes matching and maximization of the mutual information methods. The user interface was designed to support the manual registration of the images. Fused images were composed by overlaying one image with the other one transparently, in which the opacity of the overlaid image was interactively controlled. FIRE was successfully applied to many clinical cases for which automatic and/or manual registration was required. An OS and platform independent program for image registration developed in this study will be useful for the clinical application of image registration techniques.

Algorithms↗
PubMed2005

Biological properties of 2'-[18F]fluoroflumazenil for central benzodiazepine receptor imaging.

A novel positron emitting agent, 2'-[18F]fluoroflumazenil (fluoroethyl 8-fluoro-5-methyl-6-oxo-5,6-dihydro-4H-benzo-[f]imidazo[1,5-a][1,4]diazepine-3-carboxylate, FFMZ), has been reported for benzodiazepine imaging. In the present study, biological properties of [18F]FFMZ were investigated. Stability tests of [18F]FFMZ in human and rat sera were performed. Biodistribution was investigated in mice and phosphorimages of brains were obtained from rats. A receptor binding assay was performed using rat brain (mixture of cortex and cerebellum) homogenate. A static positron emission tomography (PET) image was obtained from a normal human volunteer. Although [18F]FFMZ was stable in human serum, it was rapidly hydrolyzed in rat serum. The hydrolysis was 39%, 63% and 92% at 10, 30 and 60 min, respectively. According to the biodistribution study in mice, somewhat even distribution (between 2 approximately 3% ID/g) was observed in most organs. Intestinal uptake increased up to 6% ID/g at 1 h due to biliary excretion. Bone uptake slowly increased from 1.5% to 3.5% ID/g at 1 h. High uptakes in the cortex, thalamus and cerebellum, which could be completely blocked by coinjection of cold FMZ, were observed by phosphorimaging study using rats. Determination of Kd value and Bmax using rat brain tissue was performed by Scatchard plotting and found 1.45+/-0.26 nM and 1.08+/-0.03 pmol/mg protein, respectively. The PET image of the normal human volunteer showed high uptake in the following decreasing order: frontal cortex, temporal cortex, occipital cortex, cerebellum, parietal cortex and thalamus. In conclusion, the new FMZ derivative, [18F]FFMZ appears to be a promising PET agent for central benzodiazepine receptor imaging with a convenient labeling procedure and a specific binding property.

Animals↗
PubMed2005

Diagnostic performance of 18F-FDG PET and ictal 99mTc-HMPAO SPET in pediatric temporal lobe epilepsy: quantitative analysis by statistical parametric mapping, statistical probabilistic anatomical map, and subtraction ictal SPET.

We investigated the diagnostic performance of 18F-FDG PET and ictal (99m)Tc-HMPAO SPET in pediatric temporal lobe epilepsy (TLE). Twenty-one pediatric TLE patients were enrolled in this study. Their diagnoses were confirmed by histology and post-surgical outcome (Engel class I or II). The patients' ages were 18 or younger (15+/-3 years). Of the 21 patients, 21 patients underwent 18F-FDG PET scan and 15 underwent ictal (99m)Tc-HMPAO SPET. Preoperative PET and/or ictal SPET images were reviewed by simple visual assessment and by statistical parametric mapping (SPM). Asymmetric indices (AI) were calculated using statistical probabilistic anatomical map (SPAM) on 18F-FDG PET. In nine patients who underwent both ictal and interictal SPET, SISCOM (subtraction ictal SPET coregistered to MR template) was performed. PET correctly localized epileptogenic zones in 20 of 21 (95%) by visual assessment. SPM analysis of PET correctly localized epileptogenic zones in 18 of 21 (86%). Ictal SPET correctly localized epileptogenic zones in 12 of 15 (80%) by visual assessment. SPM analysis of ictal SPET correctly localized epileptogenic zones in 12 of 15 (80%). SISCOM correctly localized 8 of 9 (89%), which was equal to that of visual assessment of ictal SPET. The AIs of the temporal lobes by PET were -15+/-8.4 in the left and 9.9+/-8.9 in the right TLE (normal control: -2.9+/-2.8), and correctly localized epileptogenic zones in all cases. As is found in adult TLE, PET and ictal SPET efficiently localized epileptogenic zones in pediatric TLE. SPM analysis of PET or ictal SPET could be used as an aid to visual assessment. Moreover, SISCOM was equal visual assessment of ictal SPET images in terms of lesion localizations.

Adolescent↗
PubMed2005

Altered gene expression profiles by sodium/iodide symporter gene transfection in a human anaplastic thyroid carcinoma cell line using a radioactive complementary DNA microarray.

BACKGROUND: The sodium/iodide symporter (NIS) is a membrane glycoprotein that mediates active 131I uptake during the treatment of cancer of the thyroid gland and extrathyroidal tissues. NIS gene transfection, a gene-therapy modality, has been introduced in many types of cancer, such as prostate cancer and breast cancer, and has demonstrated a high potential for the treatment of non-thyroidal cancers. AIM: To investigate the pattern of NIS gene expression and provide evidence of its beneficial effects in human anaplastic cancer ARO cells by using a radioactive complementary DNA (cDNA) microarray. METHODS: For cDNA microarray data analysis, superimposed images and clustergrams were prepared from basic radioactivity data obtained using a phosphoimager system. Gene expression profiles were constructed using the Z-transformed values of genes related to cancer biology. RESULTS: Radioactive cDNA microarray studies showed that 11 genes were upregulated (Z ratio > 1.5) and 31 genes were downregulated (Z ratio < -1.5) in response to NIS gene transfection. Of these differentially expressed genes, 33% were related to cell proliferation and apoptosis. Moreover, NIS gene transfection into an anaplastic thyroid cancer cell line affected the expression of the protein tyrosine phosphatase (PTP) family and Ras oncogene family, including Ras, Rac and Rab. CONCLUSION: The identification of changes in the patterns of gene expression may provide a better understanding of the response of molecular mechanisms to NIS gene transfection.

Carcinoma↗
PubMed2005

Reversing the silencing of reporter sodium/iodide symporter transgene for stem cell tracking.

UNLABELLED: To track neural stem cells transfected with reporter gene, perpetual stem cell transgene expression is required. Referring to the knowledge about epigenetic modulation, we succeeded in reversing the silencing of sodium/sodide symporter (hNIS) transgenes transfected into human neural stem (HB1.F3) cells. METHODS: hNIS and hygromycin resistance gene were linked with IRES (Internal Ribosome Entry Site) under control of cytomegalovirus promoter, and this construct was transfected into HB1.F3 cells to yield the F3-NIS cell lines. hNIS transgene expression was examined by (125)I uptake and reverse transcriptase polymerase chain reaction (RT-PCR). The iodide uptake of F3-NIS III cells was initially higher by up to 12.9-fold than that of nontransfected HB1.F3 cells. However, repeated passage gradually silenced hNIS expression. The recovery of hNIS transgene expression by demethylating agent (5-azacytidine) or histone deacetylase inhibitor (trichostatin A; TSA) treatment was investigated. RESULTS: As hNIS transgene was gradually silenced in F3-NIS III cells, after the eighth passage its iodide uptake was 1.9-fold higher than that of nontransfected HB1.F3 cells. 5-azacytidine treatment (up to 40 micromol/L) for 24 h in F3-NIS III cells increased iodide uptake and hNIS messenger RNA (mRNA) 1.8- and 1.9-fold versus nontreated F3-NIS cells, respectively. Moreover, after TSA treatment (up to 62.5 nmol/L) for 24 h, iodide uptake and hNIS mRNA in F3-NIS III cells increased 36- and 1.9-fold versus nontreated F3-NIS III cells, respectively. The synergistic effect of demethylation and histone deacetylation inhibition was significant at high-dose 5-azacytidine and low-dose of TSA treatment. After treating F3-NIS III cells in vitro for 24 h with 62.5 nmol/L TSA, the cells were implanted into BALB/c nude mice. The TSA-treated F3-NIS III cells were clearly visible on gamma-camera imaging using (99m)Tc-pertechnetate as compared with F3-NIS III cells not treated with TSA. CONCLUSION: These results suggest that 2 well-known mechanisms of epigenetic modulation synergistically are involved in silencing reporter hNIS transgene in a neural stem cell line. Transgene silencing was reversed using demethylation and histone deacetylation inhibition. We conclude that silenced reporter transgenes once successfully expressed in stem cells might be awakened by pharmacologic treatment before infusion to track stem cells in vivo.

Animals↗
PubMed2005

Development of a sodium/iodide symporter (NIS)-transgenic mouse for imaging of cardiomyocyte-specific reporter gene expression.

UNLABELLED: Development of a small animal imaging system for differentiated cell-specific reporter gene expression will enable us to image cellular differentiation in vivo. In this study, we developed a sodium/iodide symporter (NIS)-transgenic mouse in which NIS is constitutively expressed as an imaging reporter gene only in cardiomyocytes. METHODS: To express NIS gene in cardiomyocytes, alpha-myosin heavy chain (alpha-MHC)-NIS was constructed and used for the production of NIS-transgenic mice. Twelve lines of positive founder were obtained. The adequacy of the transgenic mouse model was tested by in vivo scintigraphy, microPET, and a biodistribution study. RESULTS: The myocardium of transgenic mice showed rapid and intense uptake of 131I, which was much higher than that of the thyroid, and also showed long retention by gamma-camera pinhole imaging. The relative uptake ratio of the heart of transgenic mice was 4.6 +/- 1.5, which was 3.8 +/- 1.2 times higher than that of control wild-type mice. The uptake of the heart was completely blocked by oral administration of KClO4, an NIS inhibitor. The heart of transgenic mouse was also clearly and intensely visualized on microPET using 124I. Biodistribution data of these mice showed the uptake of 40-160 %ID/g (percentage injected dose per gram of tissue) of (99m)Tc-pertechnetate in the heart compared with 40-60 %ID/g in the stomach, respectively. NIS expression in the myocardium was confirmed by immunohistochemistry using a NIS-specific antibody. CONCLUSION: We developed a transgenic mouse model to image cardiomyocytes with a gamma-camera and microPET using an alpha-MHC promoter and NIS. The transgenic mouse can be used as an imaging model for cardiomyocyte-specific reporter gene expression and cellular differentiation into cardiomyocytes after cardiac stem or progenitor cell transplantation.

Animals↗
PubMed2005

Generation of parametric image of regional myocardial blood flow using H(2)(15)O dynamic PET and a linear least-squares method.

UNLABELLED: Although a parametric image of myocardial blood flow (MBF) can be obtained from H(2)(15)O PET using factor and cluster analysis, this approach is limited when factor analysis fails to extract each cardiac component. In this study, a linear least-squares (LLS) method for estimating MBF and generating a MBF parametric image was developed to overcome this limitation. The computer simulation was performed to investigate the statistical properties of the LLS method, and MBF values obtained from the MBF parametric images in dogs were compared with those obtained using the conventional region of interest (ROI) and invasive microsphere methods. METHODS: A differential model equation for H(2)(15)O in the myocardium was modified to incorporate the partial-volume and spillover effect. The equation was integrated from time 0 to each PET sampling point to obtain a linearlized H(2)(15)O model equation. The LLS solution of this equation was estimated and used to calculate the MBF, the perfusable tissue fraction (PTF), and the arterial blood volume fraction (V(a)). A computer simulation was performed using the input function obtained from canine experiments and the tissue time-activity curves contaminated by various levels of Poisson noise. The parametric image of the MBF, PTF, and V(a) was constructed using the PET data from dogs (n = 7) at rest and after pharmacologic stress. The regional MBF from the parametric image was compared with those produced by the ROI method using a nonlinear least-squares (NLS) estimation and an invasive radiolabeled microsphere technique. RESULTS: The simulation study showed that the LLS method was better than the NLS method in terms of statistical reliability, and the parametric images of the MBF, PTF, and V(a) using the LLS method had good image quality and contrast. The regional MBF values using the parametric image showed a good correlation with those using the ROI method (y = 0.84x + 0.40; r = 0.99) and the microsphere technique (y = 0.95x + 0.29; r = 0.96). The computation time was approximately 10 s for the 32 x 32 x 6 x18 (pixel x pixel x plane x frame) matrix. CONCLUSION: A noninvasive, very fast, and accurate method for estimating the MBF and generating a MBF parametric image was developed using the LLS estimation technique and H(2)(15)O dynamic myocardial PET.

Animals↗
PubMed2004

Time course of functional recovery after coronary artery bypass grafting surgery according to the preoperative reversibility of perfusion impairment on myocardial SPECT.

PURPOSE: Ischaemic myocardial dysfunction shows different time courses of functional recovery according to the pathophysiological characteristics of the dysfunction. In this study, we investigated the time course of functional recovery according to the preoperative reversibility of perfusion impairment on myocardial single-photon emission computed tomography (SPECT) after revascularisation surgery. METHODS: Forty-eight patients (42 men and 6 women; mean age 59+/-9 years) who underwent revascularisation surgery were included in the study. 201Tl rest/dipyridamole stress (99m)Tc-sestamibi gated SPECT was performed 10+/-8 days before (preoperative), 105+/-13 days after (early follow-up) and 497+/-66 days after (late follow-up) surgery. Using a 20-segment model, segmental perfusion and thickening were quantified with automatic software. As an indicator of the reversibility of perfusion impairment, a reversibility score (RevS) was defined as a measure of rest minus stress perfusion values. Segmental dysfunction and functional recovery were defined from quantified thickening values. Function-recovered segments were divided into early recovery and late recovery groups, and preoperative perfusion status was compared in these groups. Function-recovered segments were also re-classified into high-RevS and low-RevS groups according to the preoperative RevS, and the time courses of functional recovery were investigated in each group. RESULTS: A total of 502 segments were included in the analysis and 263 were finally classified as function-recovered segments. Of these, 172 were in the early recovery and 91 in the late recovery group. In terms of preoperative perfusion status, RevS was 8.9+/-10.8 in the early recovery group and 5.4+/-11.0 in the late recovery group (P=0.01). When all 502 segments were classified by RevS, no difference in the proportion of final function recovery was observed between the high-RevS and the low-RevS group (54% vs 51%). However, the proportion of early recovery was higher in the high-RevS group (73%) than in the low-RevS group (57%) (P=0.01). CONCLUSION: Ischaemic dysfunctional myocardium with reversible perfusion impairment tends to recover function earlier after revascularisation surgery than myocardium with a persistent decrease in perfusion.

Coronary Artery Bypass↗
PubMed2004

11C-methionine PET as a prognostic marker in patients with glioma: comparison with 18F-FDG PET.

PURPOSE: The purpose of this study was to compare the prognostic value of 11C-methionine (MET) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in glioma patients. METHODS: The study population comprised 47 patients with gliomas (19 glioblastoma, 28 others). Pretreatment magnetic resonance imaging, MET PET and FDG PET were performed within a time interval of 2 weeks in all patients. The uptake ratio and standard uptake values were calculated. Univariate and multivariate analyses were done to determine significant prognostic factors. Ki-67 index was measured by immunohistochemical staining, and compared with FDG and MET uptake in glioma. RESULTS: Among the several clinicopathological prognostic factors, tumour pathology (glioblastoma or not), age (> or =60 or <60 years), Karnofsky performance status (KPS) (> or =70 or <70) and MET PET (higher uptake or not compared with normal cortex) were found to be significant predictors by univariate analysis. In multivariate analysis, tumour pathology, KPS and MET PET were identified as significant independent predictors. The Ki-67 proliferation index was significantly correlated with MET uptake (r=0.64), but not with FDG uptake. CONCLUSION: Compared with FDG PET in glioma, MET PET was an independent significant prognostic factor and MET uptake was correlated with cellular proliferation. MET PET may be a useful biological prognostic marker in glioma patients.

Brain Neoplasms↗
PubMed2004

Site-specific 99mTc-labeling of antibody using dihydrazinophthalazine (DHZ) conjugation to Fc region of heavy chain.

The development of an antibody labeling method with 99mTc is important for cancer imaging. Most bifunctional chelate methods for 99mTc labeling of antibody incorporate a 99mTc chelator through a linkage to lysine residue. In the present study, a novel site-specific 99mTc labeling method at carbohydrate side chain in the Fc region of 2 antibodies (T101 and rabbit anti-human serum albumin antibody (RPAb)) using dihydrazinophthalazine (DHZ) which has 2 hydrazino groups was developed. The antibodies were oxidized with sodium periodate to produce aldehyde on the Fc region. Then, one hydrazine group of DHZ was conjugated with an aldehyde group of antibody through the formation of a hydrazone. The other hydrazine group was used for labeling with 99mTc. The number of conjugated DHZ was 1.7 per antibody. 99mTc labeling efficiency was 46-85% for T101 and 67-87% for RPAb. Indirect labeling with DHZ conjugated antibodies showed higher stability than direct labeling with reduced antibodies. High immunoreactivities were conserved for both indirectly and directly labeled antibodies. A biodistribution study found high blood activity related to directly labeled T101 at early time point as well as low liver activity due to indirectly labeled T101 at later time point. However, these findings do not affect practical use. No significantly different biodistribution was observed in the other organs. The research concluded that DHZ can be used as a site-specific bifunctional chelating agent for labeling antibody with 99mTc. Moreover, 99mTc labeled antibody via DHZ was found to have excellent chemical and biological properties for nuclear medicine imaging.

Animals↗
PubMed2004

[18F]FDG PET as a substitute for second-look laparotomy in patients with advanced ovarian carcinoma.

The aim of this study was to compare the prognostic value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) with that of second-look laparotomy (SLL) in patients with advanced ovarian carcinoma following primary chemotherapy. Fifty-five patients who had undergone cytoreductive surgery and adjuvant chemotherapy for advanced ovarian carcinoma were enrolled in the study. Thirty patients underwent SLL after primary treatment (SLL group), while 25 underwent FDG PET after primary treatment without SLL (PET group) We retrospectively reviewed the medical records of the 55 patients for comparison of progression-free interval and disease-free interval between the two groups. Ovarian carcinomas recurred in 37 of the 55 patients. When the progression-free interval and the disease-free interval in patients in the PET group were compared with those in the SLL group, no significant differences were observed. The progression-free interval in the PET and SLL groups were 28.8 +/- 12.7 months and 30.6 +/- 13.7 months, respectively (P = 0.29). The disease-free interval in the negative PET group was 40.5 +/- 11.6 months, and that in the negative SLL group was 48.6 +/- 12.1 months (P = 0.12). In conclusion, FDG PET has a similar prognostic value to SLL, and can substitute for SLL in the follow-up of patients who have had ovarian carcinoma, especially when there is a high risk for recurrence.

Adult↗