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T Nishimura

Publications and source records attributed to T Nishimura.

At least 253 records · Page 14Linked to original sources
PubMed1999

Feasibility of fluorodeoxyglucose dual-head gamma camera coincidence imaging in the evaluation of lung cancer: comparison with FDG PET.

UNLABELLED: The purpose of this study was to elucidate the feasibility of fluorodeoxyglucose gamma camera coincidence imaging (FDG GCI) in the evaluation of lung cancer in comparison with FDG PET. METHODS: Twenty-three patients with recently diagnosed lung cancer were examined with both FDG PET and FDG GCI on the same day. Pulmonary lesions were analyzed visually and semiquantitatively using the ratio of lesion-to-background counts (L/B ratio). The L/B ratio of FDG PET without attenuation correction (AC) was also calculated and compared. Nodal stations were only visually analyzed. RESULTS: FDG GCI and FDG PET could detect 22 and 23, respectively, of 23 pulmonary lesions by visual analysis (95.7% versus 100%). The L/B ratio of FDG GCI was 4.26 +/- 2.55, and significantly lower than that of FDG PET (9.29 +/- 4.95; P < 0.01). The L/B ratio of FDG PET was significantly higher with AC than that without AC (9.29 +/- 4.95 vs. 6.66 +/- 4.65; P < 0.01). When the L/B ratio threshold was set at 5.0 for FDG PET and 2.7 for FDG GCI, their sensitivity was 87.0% and 73.9%, respectively. Of the 3 and 6 patients with false-negative results on semiquantitative analysis, the lesions in 3 patients on FDG PET and 4 patients on FDG GCI were less than or equal to 2.0 cm in greatest diameter, respectively. In the assessment of mediastinal involvement, FDG PET was 77.8% sensitive, 78.6% specific and 78.3% accurate, whereas FDG GCI was 77.8% sensitive, 92.9% specific and 87.0% accurate. In the hilar regions, FDG PET was 100% sensitive, 84.2% specific and 87.0% accurate, whereas FDG GCI was 75.0% sensitive, 89.5% specific and 87.0% accurate. CONCLUSION: In this study, FDG GCI yielded results comparable to FDG PET on visual analysis to detect pulmonary lesions and lymph node metastases. However, the lesion-to-background contrasts of pulmonary lesions and nodal involvement were lower in FDG GCI than in FDG PET. Comparison between the L/B ratio of FDG PET with and without AC indicated that, with AC, FDG GCI would be closer to FDG PET in the evaluation of lung cancer.

Adenocarcinoma↗
PubMed1999

[Clinical study of retroperitoneal lymph node dissection for patients with advanced germ cell tumors].

We performed retroperitoneal lymph node dissection (RPLND) on 14 patients (IIA: 1, IIB: 4, IIIA: 3, IIIB2: 2, IIIC: 4) with testicular and one with retroperitoneal germ cell tumor at the Nagoya University Hospital between 1986 and 1997. According to the international germ cell consensus classification, 4 patients were classified as "good-prognosis", three as "intermediate-prognosis" and eight as "poor-prognosis". RPLND was performed on 12 patients with the tumor marker levels normalized preoperatively and on three without the marker normalization. The mean surgical time was 510 (195-1, 125) minutes and the mean bleeding volume was 3,806 (100-12,598) g. The surgical time and bleeding volume were correlated with the size of the tumor in the body axis. Intraoperative complications occurred in 5 (33%) out of 15 patients: injury of renal artery (2), renal vein (1), ureter (1) and common iliac artery (2). Postoperative complications occurred in 2 patients: ileus (2) and lower extremity edema resulting from resection of the inferior vena cava (1) and would dehiscence (1). Of the 8 patients whose completely resected retroperitoneal tumors were necrosis/fibrosis or teratoma (psCR), 6 achieved survival with no evidence of disease (NED). Among 4 patients, whose tumor was not completely resected but pathologically diagnosed as necrosis/fibrosis or teratoma (pCR), NED without recurrence was achieved in 2 and also in one with resection of relapsed teratoma 2.5 years after RPLND. All three patients with cancer tissues pathologically retained in the resected tumors (sCR or psIR), consequently died of the disease. In six patients with relapse, the initial sign was elevation of the tumor marker levels, which was noted more than 30 days postoperatively in 2 patients with psCR and 7 to 15 days in 4 patients without psCR. We believe that RPLND is needed to examine the pathology and to predict the prognosis of the poor-risk patients with NSGCT. Careful dissection of vessels is needed to reduce vascular complications.

Adolescent↗
PubMed1999

Applicability of 99mTc-HL91, a putative hypoxic tracer, to detection of tumor hypoxia.

UNLABELLED: To elucidate the applicability of 99mTc-HL91 (HL91) a putative hypoxic tracer, to the imaging of hypoxia in tumors, a biodistribution study of the tracer was performed. The intratumoral distribution of HL91 was compared with that of 14C-deoxyglucose (DG) and the expression of glucose transporter 1 (GLUT1) in an implanted tumor. METHODS: Biodistribution of HL91 after intravenous injection into Wistar rats with rat mammary tumor (Walker-256) was studied by determining blood and tissue levels of radioactivity from 15 min to 6 h after injection. Dual ex vivo autoradiography was performed on sections of the tumor using HL91 (74 MBq) and DG (185 kBq). The same sections were immunohistologically analyzed with anti-GLUT1 antibody. Tumor tissue was histologically divided into areas of viable cancer cells, necrosis and granulation tissue. The viable cancer cell area was further divided into normoxic and hypoxic areas. Uptake of both tracers in each area was measured quantitatively. The intensity of GLUT1 staining (relative optical density [ROD]) in each area was evaluated by densitometry. RESULTS: The uptake of HL91 in the tumor reached a maximal value (0.897 +/- 0.118% ID [injected dose], mean +/- SD, n = 5) at 120 min after intravenous injection of HL91, then gradually decreased. The tumor-to-muscle ratio continued to increase until 360 min (4.34 at 120 min, 7.01 at 240 min and 10.4 at 360 min). HL91 accumulated to significantly higher levels in the hypoxic area than those in the other tissues (P < 0.0001). Uptake of DG and expression of GLUT1 were significantly higher in the hypoxic area than in the normoxic area (P < 0.0001). In the viable cancer cell area, uptake of HL91 and expression of GLUT1 were strongly correlated (r = 0.624-0.868, mean r = 0.743, P < 0.0001), and DG uptake was moderately correlated with GLUT1 expression (r = 0.328-0.669, mean r = 0.505, P < 0.0001). CONCLUSION: These results indicate that HL91 can be used to detect tumor hypoxia.

Animals↗
PubMed1999

[Assessment of cardiac function and myocardial metabolism by nuclear medicine].

Simultaneous assessment of myocardial perfusion and cardiac function came to be possible by 99mTc myocardial perfusion agents. We can use ECG-gated SPECT and first pass radionuclide angiocardiography for it. ECG-gated SPECT made it possible to assess wall motion using wall thickening and QGS (quantitative gated SPECT) analysis, which are useful in various clinical situations. First pass radionuclide angiocardiography gives good assessment of cardiac function during stress, and supports the diagnosis of myocardial ischemia. On the other hand, the assessment of myocardial metabolism is another specific feature of nuclear cardiology. 123I-BMIPP SPECT is applicable to various cardiac diseases such as ischemic heart disease, and 18F-FDG PET has been considered as the gold standard of myocardial viability. Recently, gamma camera for 18F-FDG imaging has been developed, which may make FDG imaging more popular.

Heart↗
PubMed1999

Comparison of dual-head coincidence gamma camera FDG imaging with FDG PET in detection of breast cancer and axillary lymph node metastasis.

UNLABELLED: Dual-head coincidence gamma camera 18F-fluorodeoxyglucose (FDG) imaging was compared with FDG PET in the detection of breast cancer and axillary lymph node metastasis. METHODS: Both coincidence gamma camera FDG imaging and FDG PET were performed in a cylindrical phantom containing spheres of different sizes and activity ratios (5:1, 10:1 and 15:1) and in 30 women (age range 32-78 y) with suspected breast cancer. Biopsies or mastectomies were performed in all patients. Images were visually assessed, and the count ratio between tumor and normal tissue (T/N ratio) was calculated. RESULTS: In the phantom studies, coincidence gamma camera imaging visualized the smallest sphere (1.0 cm) at a ratio of 15:1 but not at ratios of 5:1 and 10:1. Coincidence gamma camera imaging visualized the other spheres (> or =1.3 cm) at all ratios. PET visualized all spheres at all ratios. In the clinical studies, 22 of 26 breast carcinomas detected by PET were also detected by coincidence gamma camera imaging.. Coincidence gamma camera imaging detected all of the carcinomas > or =2 cm in diameter (n = 10) and 12 of 16 carcinomas <2 cm. In breast carcinomas detected by both PET and coincidence gamma camera imaging, the T/N ratio in non-attenuation-corrected PET (7.12 +/- 7.13) was significantly higher than in coincidence gamma camera imaging (2.90 +/- 1.47, P < 0.005). Four of 8 axillary lymph node metastases detected by PET were detected by coincidence gamma camera imaging. Of 9 axillary lymph node metastases <1.0 cm in diameter, 7 and 3 were detected by PET and coincidence gamma camera imaging, respectively. CONCLUSION: Coincidence gamma camera imaging is useful in detecting breast carcinoma > or =2 cm in diameter but is not reliable for breast carcinoma <2 cm in diameter. Coincidence gamma camera imaging may be useless or even dangerous in the detection of axillary lymph node metastasis.

Adult↗
PubMed1999

Determination of the cross-linked residues in homo-dimerization of S19 ribosomal protein concomitant with exhibition of monocyte chemotactic activity.

When S19 ribosomal protein molecules are intermolecularly cross-linked by a transglutaminase-catalyzed reaction, the monocyte chemotactic activity is newly expressed. Heparin, at a concentration of 1 U/ml, greatly augmented the cross-linking reaction. This augmentation was due to binding affinity of S19 ribosomal protein to heparin. The major heparin-binding region of S19 ribosomal proteins was identified to Lys23-Lys-Ser-Gly-Lys-Leu-Lys29, using region-directed mutant proteins. The amino acid residues of S19 ribosomal protein used for the intermolecular cross-linkage were then determined by the peptide map analysis with amino acid sequencing and by the site-directed mutagenesis; Gln137 and Lys122 were used in the intermolecular cross-linkage.

Amino Acid Sequence↗
PubMed1999

Prolonged nonpulsatile left heart bypass diminishes vascular contractility.

We investigated possible functional changes in the vascular system accompanying the morphological change in prolonged nonpulsatile left heart bypass (LHB). Three adult goats underwent pulsatile LHB. Two weeks postoperatively, the pulsatile ventricular assist device was replaced with a centrifugal pump and nonpulsatile LHB was subsequently conducted for 4 weeks. The mean aortic pulse pressure was 39 and 16 mmHg during the pulsatile and nonpulsatile LHB, respectively Systemic vascular resistance (SVR) and plasma norepinephrine levels were measured at the end of pulsatile LHB (PUL), and at the end of 1st, 2nd, 3rd, and 4th week of nonpulsatile LHB (NP1w, NP2w, NP3w, NP4w, respectively). At each point, 50 microg/kg nitroglycerin and 1 microg/kg norepinephrine were injected and the minimal and maximal values of SVR after injection were calculated as parameters reflecting the vascular tonus and contractility. The SVR and plasma nor epinephrine level did not significantly change during the entire course (SVR: 1106, 895, 982, 920, and 938 dyne x sec x cm(-5); norepinephrine level: 0.3, 0.2, 0.1, 0.2, and 0.1 ng/ml; at PUL, NP1w, NP2w, NP3w, and NP4w, respectively). The minimal value of SVR after nitroglycerin injection remained unchanged, indicating that vascular tonus was stable during the entire course (618, 687, 623, 560, 653 dyne x sec x cm(-5), respectively). In contrast, the maximal value of SVR after norepinephrine injection at NP3w and NP4w (1695 and 1759 dyne x sec x cm(-5)) became significantly reduced compared to that at PUL (2346 dyne x sec x cm(-5)). These results indicated that prolonged nonpulsatile left heart bypass did not affect the vascular tonus, but significantly diminished the vascular contractility.

Animals↗
PubMed1999

Left ventricular volumes and ejection fraction calculated from quantitative electrocardiographic-gated 99mTc-tetrofosmin myocardial SPECT.

UNLABELLED: We compared the left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) as calculated by Cedars automated quantitative gated SPECT (QGS) to those determined by first-pass radionuclide angiography (FPRNA) and contrast left ventriculography (LVG) in a group of 21 patients (mean age 61.4 +/- 9.2 y). METHODS: A total of 740 MBq 99mTc-tetrofosmin was administered rapidly into the right cubital vein at rest, and FPRNA was performed using a multicrystal gamma camera. One hour after injection, QGS was performed with a temporal resolution of 10 frames per R-R interval. LVG was performed within 2 wk. RESULTS: The EDV, ESV and LVEF calculated by QGS were highly reproducible (intraobserver, r = 0.99, r = 0.99 and r = 0.99, respectively; interobserver, r = 0.99, r = 0.99 and r = 0.99, respectively; P < 0.01) and were more consistent than those determined by FPRNA (intraobserver, r = 0.97, r = 0.95 and r = 0.93, respectively; interobserver, r = 0.86, r = 0.96 and r = 0.91, respectively; P < 0.01). There was a good correlation between EDV, ESV and LVEF by FPRNA and those by LVG (r = 0.61, r = 0.72 and r = 0.91, respectively; P < 0.01), and there was an excellent correlation between QGS and LVG (r = 0.73, r = 0.83 and r = 0.87, respectively; P < 0.01). The mean EDV by QGS (100 +/- 11.3 mL) was significantly lower than by FPRNA (132 +/- 16.8 mL) or LVG (130 +/- 8.1 mL), and the mean ESV by QGS (53.8 +/- 9.3 mL) was lower than by FPRNA (73.0 +/- 13.3 mL). Ejection fraction values were highest by LVG (57.1% +/- 3.2%), then QGS (51.8% +/- 3.0%) and FPRNA (48.9% +/- 2.4%). CONCLUSION: QGS gave more reproducible results than FPRNA. LV volumes and LVEF calculated by QGS correlated well to those by LVG.

Adult↗
PubMed1999

[Development of a multiple side-hole sheath introducer for use in aortography].

We developed a multiple side-holed sheath introducer that can also be used as a catheter for aortography before selective arteriography of the pelvic organs or lower extremities, as an alternative to straight or pig-tail catheters, which were formerly used for aortography. Aortography using the multiple side holed sheath introducer provided good detection of arteries in 100% of 10 cases, without any complications or difficulties. Thus, the present sheath introducer can replace straight or pig-tail catheters, resulting in the more economical use of one catheter prior to selective arteriography.

Aortography↗
PubMed1999

Perception and conception: separate memory systems in the medial temporal lobe.

The purpose of the present study was to investigate, by using positron emission tomography, whether the functionally different types of information are subserved by different memory systems in human medial temporal lobe structures. Before explicit retrieval tests during scans, subjects studied words in perceptually and conceptually processed manners separately. It was found that different parts of the medial temporal lobe structures were involved in each of the different conditions. These results indicated that perceptually and conceptually processed types of information were subserved by at least two partially segregated memory systems in human medial temporal lobe structures.

Adult↗
PubMed1999

Validity of 18F-fluorodeoxyglucose imaging with a dual-head coincidence gamma camera for detection of myocardial viability.

UNLABELLED: This study investigated the validity of myocardial 18F-fluorodeoxyglucose (FDG) imaging with a dual-head gamma camera operated in coincidence detection mode (DCD-I) by comparing this technique with conventional PET and SPECT with ultra-high-energy general-purpose collimators (UHGPs). METHODS: The subjects included 5 healthy volunteers and 20 patients with a history of myocardial infarction. FDG (370 MBq) was injected intravenously after 75-g oral glucose loading, and PET, UHGP SPECT and DCD-I were performed 45, 60 and 210 min, respectively, after the injection. The target-to-background ratio of each imaging method was evaluated for the healthy volunteers by comparing myocardial uptake with uptake in the upper lungs or left ventricular cavity. Agreement between the results of the various imaging methods was investigated for the myocardial infarction patients, as was the validity of DCD-I for assessing myocardial viability as judged by comparison with myocardial perfusion SPECT. The left ventricular wall was divided into 18 regions, and uptake was evaluated using a five-grade defect score (0 = normal; 1-3 = low uptake; 4 = defect). RESULTS: The mean ratio of myocardial counts to lung counts was lower on the DCD images (2.77 +/- 1.12) than on the UHGP SPECT images (3.69 +/- 0.98) (P < 0.05). In contrast, the mean ratio of myocardial counts to left ventricular cavity counts was higher on the DCD images (2.76 +/- 1.36) than on the UHGP SPECT images (1.98 +/- 0.70) (P < 0.05). For the patients, only 30.6% of the defect scores obtained by DCD-I agreed with the scores obtained by PET, and the defect scores in the inferior and septal walls were higher for the DCD images than for the PET images. When DCD-I was compared with PET without attenuation correction (AC), agreement improved to 58.3%. When corrected by a modified AC method, DCD-I improved to 48.1%. Agreement between UHGP SPECT and PET was 55.0%. Of the segments (64) for which the defect score of the myocardial perfusion image was greater than that for the FDG PET image, DCD-I without AC, DCD-I with AC and UHGP SPECT allowed an accurate diagnosis in 12 (18.8%), 31 (48.4%) and 43 (67.2%), respectively. CONCLUSION: The image quality of DCD-I is superior to that of UHGP SPECT. However, because the effect of attenuation is marked, accurate AC, by the transmission method, for example, is required to equal the validity of PET.

Female↗
PubMed1999

[Iodine-123-MIBG scintigraphy in neuroblastoma; relationship between the intensity of uptake and tumor characteristics].

Iodine-123-MIBG (123I-MIBG) scintigraphy were performed for 23 patients with neuroblastoma at diagnosis. The intensity of MIBG activity in the primary tumor was evaluated visually (grade 3; intense uptake-grade 0; no definite uptake), and its relationship to the size, degree of tumor spread, urinary catecholamine metabolites (VMA, HVA), and histological types were investigated. The results of 123I-MIBG uptake grade were as follows: grade 3; 44% (10/23), grade 2; 30% (7/23), grade 1; 17% (4/23), grade 0; 9% (2/23). The grade was not associated with the tumor size, or the degree of tumor extension to the distant lesion, either. The more catecholamine metabolites were excreted in the urine, the tumor tended to have more intense uptake. The tumors of neuroblastoma rosette fibrillary type, and ganglioneuroblastoma poorly differentiated type had more intense uptake than neuroblastoma round cell type and ganglioneuroblastoma well differentiated type. The case of ganglioneuroma did not have definite MIBG uptake. The intensity of MIBG uptake is not relevant to the pathological grade of neuroblastoma, but considering the electromicroscopical features of neuroblastoma reported previously, it is thought to reflect the histological type.

3-Iodobenzylguanidine↗
PubMed1999

[A case of stage IV esophageal cancer successfully treated by chemoradiation].

A 63-year-old man was admitted to our institution with a hard tumor on the left side of the neck. He was diagnosed as having advanced esophageal cancer (Stage IV) with a massive supraclavicular lymph node metastasis, and the lesion was thought to be unresectable. He was treated with chemotherapy (CDDP-VDS-5-FU) and radiation therapy, and all the tumors completely disappeared on endoscopic and CT examination. A stricture with scarring was detected in the esophagus at 6 months after treatment. No neoplastic tissue was detected in the lesion, and his dysphagia was relieved by dilation of the stricture. Recurrence on the left side of the neck was detected by CT at 2.5 years after chemoradiation therapy. However, the tumor has not grown over the 2-year interval since then, so it seems to be dormant. He has now survived with a good QOL for 5 years since the first hospital admission. We conclude that advanced esophageal cancer can be treated with chemoradiation therapy if the patient is in sufficiently good overall condition.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Hemodynamic changes around cerebral arteriovenous malformation before and after embolization measured with PET.

To estimate the changes in regional cerebral blood flow (rCBF) around cerebral arteriovenous malformation (AVM) before and after embolization, 6 patients with AVM were sequentially examined with positron emission tomography (PET). PET depicted the remodeling of rCBF in the ipsilateral hemisphere of AVM after embolization. Decrease of rCBF in the ipsilateral hemisphere was also detected in patients with focal symptoms before embolization, and improvement of clinical symptoms after embolization corresponded to disappearance of rCBF decrease. PET can detect hemodynamic changes after embolization, and has a possibility to estimate the effect of embolization in patients with AVM.

Adult↗
PubMed1998

Sensitive and specific method for the determination of josamycin in human plasma by liquid chromatography-mass spectrometry.

A highly sensitive and specific method for the determination of josamycin in human plasma by LC-MS was developed and validated. Josamycin was extracted from human plasma by a single-step liquid-liquid extraction and analyzed by LC-MS via an electrospray ionization interface. Selected ion monitoring was used to detect josamycin and its internal standard. The intra-day precision and accuracy, expressed as C.V. and R.E., ranged from 2.8% to 13.5% and -10.3% to 7.6%, respectively. The lower limit of detection was 0.1 ng/ml and the lower limit of quantitation was set at 1 ng/ml when 0.5 ml of plasma was used. No endogenous interference was observed in human plasma obtained from drug-free volunteers.

Anti-Bacterial Agents↗
PubMed1998

In vitro biotransformation of atrazine by rat liver microsomal cytochrome P450 enzymes.

We studied atrazine (ATZ) metabolism in male and female rat liver microsomes in vitro, and the major metabolite was deisopropylatrazine (DeiPr-ATZ) with deethylatrazine (DeEt-ATZ) and 1-hydroxyisopropylatrazine (iPrOH-ATZ) as minor metabolites in both sexes. The enzyme kinetics of ATZ biotransformation were examined by means of Eadie-Hofstee analyses. Although no remarkable sex difference of Michaelis Menten values for each pathway was observed, Cl(int)S (Vmax/Km) for DeiPr-ATZ, DeEt-ATZ and iPrOH-ATZ were slightly higher in female than in male rats. The formation of DeiPr-ATZ, DeEt-ATZ and iPrOH-ATZ from ATZ was substantially inhibited by SKF-525A, metyrapone, diallyl sulfide, 7-ethoxycoumarin, benzphetamine, nicotine, testosterone and lauric acid in both sexes. Cimetidine effectively inhibited the formation of all metabolites in male rats. On the other hand, the inhibition rates of the formation of DeiPr-ATZ and iPrOH-ATZ by cimetidine in female rats were lower than those in male rats, and DeEt-ATZ was hardly affected by the chemicals. In contrast with the results for cimetidine, the inhibition of ATZ biotransformation by bufuralol was more effective in female than in male rats. Anti-rat CYP2B1 and CYP2E1 antibodies effectively inhibited DeiPr-ATZ, DeEt-ATZ and iPrOH-ATZ formations in both sexes. Anti-rat CYP2C11 antibody also inhibited the three metabolites in both sexes, with the inhibition rates higher in male than in female rats, similar to cimetidine. In the case of anti-rat CYP2D1 antibody, the inhibitory effect on ATZ biotransformation in male rats was less than that in female rats. On the other hand, anti-rat CYP1A2, CYP3A2 and CYP4A1 antibodies did not affect the ATZ biotransformation in either sex. There was no significant correlation between the formation rate of ATZ metabolites and P450 isoform levels in either sex. These results may mean that CYP2B2, CYP2C11, CYP2D1 (only iPrOH-ATZ formation) and CYP2E1 in male rats, and CYP2B2, CYP2D1 and CYP2E1 in female rats are involved ATZ metabolism in liver, and that the substrate specificity of P450 isoforms for ATZ is broad.

Animals↗