Biomedical subjects

Shogo Yamada

Publications and source records attributed to Shogo Yamada.

At least 55 records · Page 3Linked to original sources

PubMed2004

Usefulness of asialoglycoprotein receptor imaging for the evaluation of liver metastasis of neuroblastoma.

Neuroblastoma, derived from the neural crest ectoderm, is the most common type of solid abdominal mass seen in infancy. The diagnosis, staging, and follow-up of neuroblastoma are often performed using metaiodobenzylguanidine (MIBG) imaging. However, the evaluation of liver metastasis by this method is complicated by the normal physiological uptake of MIBG by the liver. The asialoglycoprotein receptor is a hepatic cell-surface receptor specific for galactose-terminated glycoprotein, and 99mTc-DTPA-galactosyl human serum albumin (GSA) accumulates selectively in hepatic cells. Here, we report a case of congenital neuroblastoma with liver metastasis in which GSA scans were useful for differentiation between normal and metastatic sites in the liver.

3-Iodobenzylguanidine↗

PubMed2004

Scatter and cross-talk correction for one-day acquisition of 123I-BMIPP and 99mtc-tetrofosmin myocardial SPECT.

OBJECTIVE: 123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-tetrofosmin (TET) are widely used for evaluation of myocardial fatty acid metabolism and perfusion, respectively. ECG-gated TET SPECT is also used for evaluation of myocardial wall motion. These tests are often performed on the same day to minimize both the time required and inconvenience to patients and medical staff. However, as 123I and 99mTc have similar emission energies (159 keV and 140 keV, respectively), it is necessary to consider not only scattered photons, but also primary photons of each radionuclide detected in the wrong window (cross-talk). In this study, we developed and evaluated the effectiveness of a new scatter and cross-talk correction imaging protocol. METHODS: Fourteen patients with ischemic heart disease or heart failure (8 men and 6 women with a mean age of 69.4 yr, ranging from 45 to 94 yr) were enrolled in this study. In the routine one-day acquisition protocol, BMIPP SPECT was performed in the morning, with TET SPECT performed 4 h later. An additional SPECT was performed just before injection of TET with the energy window for 99mTc. These data correspond to the scatter and cross-talk factor of the next TET SPECT. The correction was performed by subtraction of the scatter and cross-talk factor from TET SPECT. Data are presented as means +/- S.E. Statistical analyses were performed using Wilcoxon's matched-pairs signed-ranks test, and p < 0.05 was considered significant. RESULTS: The percentage of scatter and cross-talk relative to the corrected total count was 26.0 +/- 5.3%. EDV and ESV after correction were significantly greater than those before correction (p = 0.019 and 0.016, respectively). After correction, EF was smaller than that before correction, but the difference was not significant. Perfusion scores (17 segments per heart) were significantly lower after as compared with those before correction (p < 0.001). CONCLUSIONS: Scatter and cross-talk correction revealed significant differences in EDV, ESV, and perfusion scores. These observations indicate that scatter and cross-talk correction is required for one-day acquisition of 123I-BMIPP and 99mTc-tetrofosmin SPECT.

Aged↗

PubMed2004

Local control and recurrence of stage I non-small cell lung cancer after carbon ion radiotherapy.

BACKGROUND AND PURPOSE: For a proper evaluation of the relationship between carbon ion beam dose escalation and local control in the 81 patients with 82 lesions of stage I non-small cell lung cancer, we have identified the incidence of in-field recurrence by collating the dose distribution with the CT images. PATIENTS AND METHODS: Eighteen fractions over 6 weeks for 47 patients (48 lesions) and nine fractions over 3 weeks for 34 patients were applied in the carbon dose escalation method from 59.4 to 95.4 gray equivalents (GyE) by a 10% increment and from 68.4 to 79.2GyE by a 5% increment, respectively. The radiation target consisted of primary tumor. Image analysis of the patients with local recurrence was systematically performed after the treatment by focusing attention on the enhanced thin slice CT images of the primary lesion. By superimposing the dose distribution on the planning CT image and marking the anatomically identified loci of recurrence, it was possible to establish the relationship between the dose distribution and the incipient loci of recurrence and to classify the recurrence patterns from the differences in the recurrence loci. RESULTS: Local recurrence was found in 19 (23.2%) out of a total of 82 lesions. It is possible to distinguish between three recurrence patterns: Pattern 1 representing marginal recurrence and patterns 2a and 2b, which are both instances of in-field recurrence. In pattern 1, four recurrences take place from a region on the upper tumor margin. In pattern 2a, 13 recurrences take place from the center of the tumor. In pattern 2b, two recurrences take place from the near-center of the tumor. CONCLUSIONS: For the 15 in-field recurrence lesions (patterns 2a and 2b) after excluding the four marginal recurrence lesions (patterns 1), we have established that the local control shows dose-dependence. Based on this, we have determined the optimal therapeutic dose.

Adult↗

PubMed2004

E4F1, a novel estrogen-responsive gene in possible atheroprotection, revealed by microarray analysis.

Estrogen has been postulated to be involved in inhibition of vascular smooth muscle cell (VSMC) proliferation mainly via estrogen receptor (ER), but the detailed mechanism has remained primarily unknown. Therefore, in this study, microarray analysis was used in two types of cultured human VSMCs: one positive for ER alpha, and the other for ER beta, which were treated by estrogens to detect the estrogen-responsive genes. We also used quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) to evaluate mRNA levels of selective target gene (TG) in these cells. We further studied whether the TG product was involved in inhibition of proliferation using small interfering RNA (siRNA) of the TG transfection. We subsequently used quantitative RT-PCR and in situ hybridization analysis to evaluate the expression of these gene products in human aorta. E4F1, a possible inducer of cell growth arrest, was markedly increased only in ER alpha-positive VSMCs by estrogens in both microarray and RT-PCR analyses. Blocking of E4F1 using siRNA suppressed estrogenic inhibition of ER alpha-positive VSMC proliferation. E4F1 mRNA was abundant in premenopausal female aorta with mild atherosclerotic changes. E4F1 is therefore considered one of the estrogen-responsive genes involving ER alpha-mediated inhibition of VSMC proliferation and may play an important role in estrogen-related atheroprotection of human aorta.

Adenovirus E4 Proteins↗

PubMed2004

Intrinsic radiosensitivity by metallothionein expression has no great influence on clinical radiosensitivity in esophageal carcinoma.

Several studies have shown that macroscopically infiltrative type of esophageal carcinoma generally has a poorer local response to radiation therapy than that of localized type. The aim of this study was to determine the role of metallothionein (MT) as a radioprotective agent in the difference of clinical radiosensitivities in esophageal carcinoma. A total of 45 surgically resected esophageal carcinoma tissues [20 macroscopically localized type without preoperative treatment (PT), 20 macroscopically infiltrative type without PT and 5 macroscopically infiltrative type with PT] were stained for MT by immunohistochemistry and were analyzed. MT expression level of macroscopically localized type of esophageal carcinoma was significantly higher than that of infiltrative type without PT (P=0.026) and was significantly higher than that of infiltrative type with PT (P=0.024). No significant difference was found between MT expression levels in infiltrative type of esophageal carcinoma without PT and that with PT. The results of this study suggest that there is less possibility that clinical radioresistance of the tumor is due to MT expression in esophageal carcinoma and also suggest that there is less possibility that MT synthesis is induced by fractionated irradiation of a moderate dose or by an anti-cancer agent during a course of treatment.

Aged↗

PubMed2004

[Peripheral venous stenoses of hemodialysis shunts: improved long-term patency rates with stent placement].

PURPOSE: The purpose of this study was to evaluate the effectiveness of endovascular stents placed in the peripheral veins of hemodialysis shunts. MATERIALS AND METHODS: 156 endovascular stents were placed in the peripheral veins of 155 hemodialysis shunts with 220 stenoses. Among these, 106 stenoses of 93 hemodialysis shunts had been treated by percutaneous transluminal angioplasty (PTA) before stent placement. RESULTS: The initial success rate was 97.7%. Primary radiologic patency rates of the stents at 6 months, 1 year, and 2 years were 69.8%, 49.1%, and 45.8%, respectively. Secondary radiologic patency rates at 1 year, 2 years, and 3 years were 94.0%, 91.8%, and 88.0%, respectively. Primary clinical patency rates at 6 months, 1 year, and 2 years were 64.4%, 43.4%, and 27.3%; while secondary clinical patency rates at 1 year, 2 years, and 3 years were 93.5%, 86.5%, and 73.4%, respectively. Radiologic and clinical primary patency rates of 106 stenoses and 93 hemodialysis shunts were significantly higher than those of PTA that had been performed before stents were placed. CONCLUSION: Stent placement for stenoses of the peripheral veins of hemodialysis shunts recurring in three months and treated by PTA alone can improve long-term patency.

Adult↗

PubMed2003

A novel support system for patient immobilization and transportation for daily computed tomographic localization of target prior to radiation therapy.

PURPOSE: To develop a method for quick and smooth transportation of patients from a computed tomography (CT) table to a linear accelerator (linac) table for confirming tumor center before radiation therapy. MATERIALS AND METHODS: We developed a system using a subtable for patient immobilization that is transported via a customized stretcher. The patient lies on the subtable and is immobilized by a vacuum cushion and thermoplastic body cast. The subtable stretcher is used to carry the subtable from the CT table to the linac table. During transportation, the subtable is kept flat and shock to the subtable is carefully avoided. Between August 2001 and September 2002, a total of 9 patients with solitary upper lung tumors (superior to carina) were treated using this system. RESULTS: Intrafractional tumor motion along the x (left-right), y (anterior-posterior), and z axis (superior-inferior) ranged from -2 mm to 2 mm, -2 mm to 2 mm, and -5 mm to 3 mm, respectively. The standard deviation of intrafractional tumor motion along the x, y, and z axis ranged from 0.5 mm to 1.5 mm, 0 mm to 1.7 mm, and 0.6 mm to 3.5 mm, respectively. Interfractional setup errors along the x, y, and z axis ranged from -5 mm to 4 mm, -6 mm to 8 mm, and -6 mm to 6 mm, respectively, and we could reduce interfractional setup errors in the majority of treatment sessions. CONCLUSIONS: We developed a system that allows patients to be immobilized and transported to verify tumor location on a daily basis. This system is highly useful for reducing setup errors.

Aged↗

PubMed2003

Steroid sulfatase and estrogen sulfotransferase in the atherosclerotic human aorta.

Various epidemiological studies have demonstrated a relatively low incidence of cardiovascular events in premenopausal women and its marked increment after menopause. In addition, estrogens have been postulated to exert direct anti-atherogenic effects via binding to estrogen receptors in vascular smooth muscle cells (VSMCs). However, not all postmenopausal women develop atherosclerosis despite decreased levels of serum estrogen. Therefore, we believe it is important to examine the status of estrogen metabolism in situ in the human cardiovascular system. Estrone sulfate (E1S) is a major circulating plasma estrogen that is converted into the biologically active estrogen, estrone (E1) by steroid sulfatase (STS). E1 is also sulfated and reverted into E1S by estrogen sulfotransferase (EST). These two enzymes have recently been shown to play important roles in the in situ estrogen actions of estrogen-dependent human tissues and various sex steroid-dependent tumors. STS and EST, however, have not been studied in detail in the human vascular system associated with atherosclerotic changes. In the present study, we evaluated the relative abundance of STS- and EST-immunoreactive protein and mRNA expression in human aorta using immunohistochemistry and reverse transcription followed by quantitative polymerase chain reaction in addition to enzyme activity. STS expression levels were found to be significantly higher in the VSMCs obtained from female aortas with mild atherosclerotic changes than in those with severe atherosclerotic changes and in male aortas regardless of atherosclerotic changes. EST expression levels in the VSMCs of these aortas, however, were significantly higher in female aortas with severe atherosclerotic changes and in male aortas than in female aortas with mild atherosclerotic changes. We believe it is important to examine factors regulating the expression and activity of these estrogen-metabolizing enzymes in the human aorta. Various cytokines have been proposed to function as regulators of these enzymes in other tissues. In the present study, we studied the effects of interleukin (IL)-1beta, known to be produced in human atherosclerotic lesions, on the expression of these enzymes using cultured human VSMCs originally obtained from a female patient. IL-1beta markedly inhibited the expression of STS mRNA and enzyme activity, but stimulated the expression of EST mRNA and enzyme activity. In addition, IL-1beta also reduced E2 production from E1S and E1 in VSMCs. Results from the present study seem to suggest that the expression levels of both STS and EST mRNA and activity may be significantly associated with the degree of atherosclerotic changes in the female aorta, which may be related to cytokines produced in situ, such as IL-1beta, in human atherosclerotic lesions.

Adult↗

PubMed2003

Radiation therapy combined with cis-diammine-glycolatoplatinum (Nedaplatin) and 5-fluorouracil for untreated and recurrent esophageal cancer.

From January 1999 to November 2000, a total of 24 esophageal cancer patients (17 untreated and 7 recurrent cases) were treated with radiation therapy (60-70 Gy) combined with cis-diammine-glycolatoplatinum (Nedaplatin) (80-120 mg/body) and 5-fluorouracil (5-FU) (500-1,000 mg/body/24 h, continuous infusion for 5 days). Grade III leukocytopenia was observed in 6 (25%) of the patients. Grade III and IV thrombocytopenia was observed in one patient each. The 1-year and 2-year survival rates for definitively irradiated patients were 59% and 39%, respectively, and for patients with postoperative recurrence 69% and 69%, respectively. High-dose radiation combined with Nedaplatin and 5-FU is a safe and effective method for treating esophageal cancer.

Adult↗

PubMed2003

Time-related changes of radiofrequency ablation lesion in the normal rabbit liver: findings of magnetic resonance imaging and histopathology.

RATIONALE AND OBJECTIVES: To study time-related magnetic resonance imaging (MRI) and histopathological findings after radiofrequency ablation (RFA) in the normal liver. METHODS: Under ultrasound guidance, RFA was performed in 22 rabbits with a 15-gauge expandable probe inserted into the liver. The RF power was applied at 10 W initially with a 5-W increment every minute until RF power "roll-off" occurred. The rabbits subjected to postmortem MRI at 3 days (n = 6), 2 weeks (n = 6), 4 weeks (n = 6), and 12 weeks (n = 4) after RFA. Spin-echo (SE) T(1)-weighted image (WI) (TR/TE=500/12) and fast SE T2-WI (TR/TE= 3500/99) were obtained. The liver specimens were excised and processed for conventional histologic study. The MRI and pathologic findings were compared qualitatively and quantitatively. RESULTS: The lesion diameters measured with MRI and liver specimen were well correlated (P < 0.05). The coagulated regions presented 2 of 4 laminar patterns on T1/T2-WI 3 days after RFA, and 2 of 3 laminar patterns on T1/T2-WI 2 to 4 weeks after RFA. 12 weeks after RFA, the signal intensity in coagulated regions increased on T1-WI with a 2-laminar pattern still visible on T2-WI, the same as that of 2 to 4 weeks. The observed pathologic changes (enlarged sinusoids, marginal fibrous tissue and hepatocyte degeneration) could be responsible for the MRI laminar patterns and signal intensity changes. CONCLUSION: The time-related pathologic changes of RFA lesions in rabbit livers can be reflected as laminar patterns on MR images. Understanding of the zone structure of the lesions is useful for the evaluation of follow-up MRI.

Animals↗

PubMed2003

Results of radiation therapy for uterine cervical cancer using high dose rate remote after loading system.

In Japan, radiotherapy with high dose rate remote after loading system (HDR-RALS) for intracavitary brachytherapy is the standard treatment for more than 30 years. This report showed the usefulness of HDR-RALS for uterine cervical cancer. From 1980 through 1999, 442 patients with uterine cervical cancers (stage I: 66, stage II: 161, stage III: 165, stage IV: 50) were treated. Radiotherapy was performed both external teletherapy and HDR-RALS. Overall survival rate at 5 years was 60.2%. The 5-year actuarial incidence of all complications was 16.4%. The 5-year actuarial incidence of all complications in cases treated with the sum doses of whole pelvic irradiation (without central shield) and RALS up to 49 Gy, 50 to 59 Gy or larger doses were 7.5%, 11.0% and 25.2%, respectively. Radiation therapy using HDR-RALS was very effective. While the dose of whole pelvic irradiation was increased, the actuarial incidence of all complications was increased.

Actuarial Analysis↗

PubMed2003

Practical visualization of internal structure of white matter for image interpretation: staining a spin-echo T2-weighted image with three echo-planar diffusion-weighted images.

BACKGROUND AND PURPOSE: To our knowledge, no method satisfactory for clinical use has been developed to visualize white matter fiber tracts with diffusion-weighted MR imaging. The purpose of this study was to determine whether superposition of a spin-echo T2-weighted image and a color-coded image derived from three orthogonal diffusion-weighted images could show fiber tract architecture of the brain with an image quality appropriate for accurate reading with a computer monitor. METHODS: MR images from 50 consecutive cases were reviewed. Three diffusion-weighted images per section were acquired with three orthogonal motion-probing gradients. These images were registered to a corresponding spin-echo T2-weighted image. A color-coded image was synthesized from three diffusion-weighted images by assigning red, green, or blue to each diffusion-weighted image and then adding a spin-echo T2-weighted image with a weighting factor. The ability of the superposed image to delineate the white matter pathways was evaluated on the basis of the known anatomy of these pathways and qualitatively compared with that of the spin-echo T2-weighted image. RESULTS: The main white matter fiber pathways, in particular the superior longitudinal fascicle, corpus callosum, tapetum, optic radiation, and internal capsule, were more clearly and easily identified on the superposed image than on the spin-echo T2-weighted image. The time required to produce the superposed image was approximately 40 minutes. CONCLUSION: Superposition of a spin-echo T2-weighted image and a color-coded image created from three orthogonal diffusion-weighted images showed structures of the brain that were not clearly visible on the spin-echo T2-weighted image alone. Such superposition presents images that are easy to interpret correctly.

Adolescent↗

PubMed2002

Intraoperative radiation therapy (IORT) for previously untreated malignant gliomas.

BACKGROUND: Intraoperative radiation therapy (IORT) is one of the methods used to deliver a large single dose to the tumor tissue while reducing the exposure of normal surrounding tissue. However, the usefulness of intraoperative electron therapy for malignant gliomas has not been established. METHODS: During the period from 1987 to 1997, 32 patients with malignant gliomas were treated with IORT. The histological diagnoses were anaplastic astrocytoma in 11 patients and glioblastoma in 21 patients. Therapy consisted of surgical resection and intraoperative electron therapy using a dose of 12--15 Gy (median, 15 Gy). The patients later underwent postoperative external radiation therapy (EXRT) with a median total dose of 60 Gy. Each of the 32 patients treated with IORT was randomly matched with patients who had been treated with postoperative EXRT alone (control). Patients were matched according to histological grade, age, extent of tumor removal, and tumor location. RESULTS: In the anaplastic astrocytoma group, the one-, two- and five-year survival rates were 81%, 51% and 15%, respectively in the IORT patients and 54%, 43% and 21%, respectively in the control patients. In the glioblastoma group, one-, two- and five-year survival rates were 63%, 26% and 0%, respectively in the IORT patients and 70%, 18% and 6%, respectively in the control patients. There was no significant difference between survival rates in the IORT patients and control patients in either the anaplastic astrocytoma group or glioblastoma group. CONCLUSIONS: IORT dose not improve survival of patients with malignant gliomas compared to that of patients who have received EXRT alone.

Adult↗

PubMed2002

Safety and clinical benefits of transsubxiphoidal left ventricular puncture.

We performed a transsubxiphoidal LV puncture (TSLVP) to evaluate left ventricular function in 21 patients with both mechanical prosthetic aortic and mitral valves and successfully obtained hemodynamic information on each patient. Analyzing cardiac hemodynamic information and ventriculographic findings obtained with TSLVP, we concluded that seven of the patients required repair of their prosthetic valves. Five of these seven patients agreed to replacement of their valves, whereas two did not. TSLVP was performed adequately and safely without severe complications, suggesting that this maneuver is easier than that of transapical LV puncture and should be recommended for the assessment of left ventricular hemodynamic functions instead of the transapical LV puncture, especially in patients requiring replacement of two valves.

Adult↗

PubMed2002

Radiation therapy for limited-stage small-cell esophageal cancer.

Between 1985 and 1999, 20 patients with limited-stage small-cell carcinoma of the esophagus (SCEC) received radiation therapy at Tohoku University Hospital and Miyagi Cancer Center Hospital. Twelve patients received definitive radiation therapy and eight patients received postoperative prophylactic irradiation after surgery. The 1-, 2-, and 5-year survival rates of all cases were 44%, 37%, and 19%, respectively. Distant metastasis was the most frequent pattern of recurrence. Survival rates differed significantly between the 6 patients who were not treated with chemotherapy (median survival time, 5 months) and the 14 patients who were (24 months) (p = 0.0061). Good local control rates can be obtained by definite or postoperative radiation therapy for SCEC. However, SCEC should be regarded as a systemic disease, and chemotherapy should be given. Multiinstitutional studies are needed to obtain sufficiently large populations for investigation and optimization of local therapy for this disease.

Aged↗

PubMed2002

Predominant involvement of ipsilateral anterior and posterior circulations in moyamoya disease.

BACKGROUND AND PURPOSE: We encountered several patients with childhood onset of moyamoya disease in whom the ipsilateral anterior and posterior circulations were predominantly involved. This study investigated whether this is an angiographic characteristic of this disease. METHODS: We evaluated steno-occlusive lesions on angiograms of 85 patients with pediatric onset of moyamoya disease, using two 4-stage angiographic classification scales for the internal carotid artery and posterior cerebral artery systems (ICA and PCA staging, respectively) and determined whether lesions with more advanced ICA and PCA stages were on ipsilateral sides. RESULTS: When positive laterality was defined as the presence of a difference by > or =1 stage between the stages on both sides, lateralities in the ICA stages and in the PCA stages were present in 40 (47%) and 27 patients (32%), respectively. Lesions with more advanced ICA and PCA stages were on the same side, with significant probability (P=0.024, Fisher's exact test). Lateralities in both ICA and PCA lesions were found in 17 patients. In 14 (82%) of the 17 patients, the more advanced side of ICA lesions was the same as that of PCA lesions, while it was contralateral in 3 patients (18%). CONCLUSIONS: In pediatric-onset moyamoya disease, asymmetrical involvement of bilateral ICAs and PCAs was common, and the ipsilateral ICA and PCA tended to be predominantly involved.

Adolescent↗

PubMed2002

Stability of electron-beam energy monitor for quality assurance of the electron-beam energy from radiotherapy accelerators.

Information on electron energy is important in planning radiation therapy using electrons. The Geske 3405 electron beam energy monitor (Geske monitor, PTW Nuclear Associates, Carle Place, NY, USA) is a device containing nine ionization chambers for checking the energy of the electron beams produced by radiotherapy accelerators. We wondered whether this might increase the likelihood of ionization chamber trouble. In spite of the importance of the stability of such a quality assurance (QA) device, there are no reports on the stability of values measured with a Geske monitor. The purpose of this paper was therefore to describe the stability of a Geske monitor. It was found that the largest coefficient of variation (CV) of the Geske monitor measurements was approximately 0.96% over a 21-week period. In conclusion, the stability of Geske monitor measurements of the energy of electron beams from a linear accelerator was excellent.

Electrons↗

PubMed2002

Imaging of ischemic but viable myocardium using a new 18F-labeled 2-nitroimidazole analog, 18F-FRP170.

UNLABELLED: RP170, 1-(2-hydroxy-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole, is a new hypoxic radiosensitizer. We recently succeeded in labeling this compound with 18F to make 18F-FRP170, 1-(2-fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole. In this study, we attempted to visualize the ischemic but viable myocardium of rats as hot-spot images using 18F-FRP170. We also compared the distribution of 18F-FRP170 with myocardial perfusion, fatty acid metabolism, and glucose metabolism. METHODS: In open-chest rats, the left coronary artery was ligated to make an ischemic myocardial model. We evaluated the myocardial accumulation of radiotracers by the double-tracer autoradiography technique. 14C-Iodoantipyrine (IAP), 125I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP), and 14C-deoxyglucose (DG) were used as markers of myocardial perfusion, fatty acid metabolism, and glucose metabolism, respectively. Approximately 80 small circular regions of interest were placed throughout the left ventricular wall of the midventricular level section. The uptake in each region of interest was expressed as the percentage uptake of the average count in the remote area. We then defined the 18F-FRP170 high-uptake area (H-FRP) as that area where the percentage of FRP was >120% and the 18F-FRP170 low-uptake area (L-FRP) as that area where the percentage of FRP was <80%. RESULTS: On the 18F-FRP170 image of the ischemic myocardium, there was a low-uptake area in the center, which was bounded by a high-uptake area. The percentages of IAP in the H-FRP and the L-FRP were 48.5% +/- 5.8% and 2.2% +/- 0.2%, respectively; the percentages of BMIPP in the H-FRP and the L-FRP were 46.8% +/- 3.1% and 4.3% +/- 0.4%, respectively; and the percentages of DG in the H-FRP and the L-FRP were 107.0% +/- 6.8% and 4.3% +/- 0.4%, respectively. In diabetic rats, the percentages of DG in the H-FRP and the L-FRP were 407.7% +/- 14.9% and 72.5% +/- 5.0%, respectively, but the remote area on the DG image was insufficiently visualized. Histologic data using 2,3,5-triphenyltetrazolium chloride staining suggest that the high-uptake areas on 18F-FRP170 images reflect ischemic but viable myocardium. CONCLUSION: We succeeded in visualizing the ischemic but viable myocardium as a hot spot on the 18F-FRP170 image. 18F-FRP170 can be expected to provide important information for determining the necessity of coronary intervention in ischemic heart disease patients, including diabetic patients.

Animals↗