Search PubMed⌕ Search

Biomedical subjects

J Taki

Publications and source records attributed to J Taki.

At least 127 records · Page 7Linked to original sources
PubMed1993

[67Ga SPECT in the evaluation of orbital and ocular mass-like lesions].

We evaluated 67Ga SPECT in the differentiation of mass-like lesions in the orbital and ocular areas. A two-headed SPECT system equipped with parallel-hole collimator was used. 67Ga SPECT demonstrated three dimensionally the extent of tumors found by CT and MRI. 67Ga SPECT was especially useful in the assessment of localized lesions in and around the lacrimal gland. In a total of 43 patients studied, the overall accuracy of 67Ga SPECT in diagnosing orbital and ocular lesions was 72%. Sixteen of 21 malignant lesions (76%) showed true positive findings and 15 of 22 benign lesions (68%) showed true negative findings. All seven malignant lymphoma lesions showed true positive findings. One of four cases of malignant melanoma was not visualized. This lesion was less than 15 mm in diameter. None of the three cases of retinoblastoma was visualized, regardless of tumor size. Four of seven cases of pseudotumor or pseudolymphoma showed false positive findings. The differentiation of pseudotumor and pseudolymphoma from malignant lymphoma seemed to be difficult. We conclude that 67Ga SPECT is useful in the differentiation of lesions in the orbital and ocular areas and that evaluation of the extent of malignant lesions can be improved by comparing the findings obtained by morphological diagnostic modalities.

Adult↗
PubMed1993

Protective effect of the calcium channel blocker diltiazem on hepatic function following warm ischemia.

The purpose of this study was to investigate the protective effect of a calcium channel blocker diltiazem (DTZ) on hepatic ischemic injury using a canine model. Hepatic ischemia was induced by temporary clamping of hepatic afferent blood vessels for 60 min with establishment of a portojugular bypass. The administration of DTZ at a dose of 70 micrograms/kg bolus i.v. injection before hepatic ischemia and thereafter via the portal vein at a dose of 10 micrograms/kg/min well restored the hepatic blood flow (HBF, 92 +/- 5%; P < 0.01) and arterial ketone body ratio (AKBR, 1.15 +/- 0.16; P < 0.01) 1 hr after interruption compared with untreated controls (HBF, 61 +/- 7%; AKBR, 0.53 +/- 0.09). In addition, the increase of plasma lactate level and the decrease of mean arterial pressure were significantly suppressed after ischemia (P < 0.05). We concluded that DTZ has a protective effect on ischemia-induced hepatic damage and might be useful in the prevention of primary graft failure caused by warm ischemia in liver transplantation.

Animals↗
PubMed1993

Regional uptake of iodine-125-metaiodobenzylguanidine in the rat heart.

Regional uptake of iodine-125-metaiodobenzylguanidine ([125I]MIBG) was evaluated in normal (n = 12) and reserpinized (n = 12) rat hearts. At 15 min and 1, 3 and 6 h after injection of [125I]MIBG, tissue activities were calculated for the right ventricular myocardium (RV), the whole left ventricular myocardium (whole LV), the epicardial layer of the left ventricular myocardium (Ep LV), the endocardial layer of the left ventricular myocardium (En LV), the basal segment of the left ventricular myocardium and the apical segment of the left ventricular myocardium. The uptake of [125I]MIBG at 6 h after injection in the normal rat heart was higher in RV than in whole LV (0.45 +/- 0.09% vs 0.30 +/- 0.06% kg dose/g), and in Ep LV than in En LV (0.32 +/- 0.07% vs 0.25 +/- 0.05%). In the reserpinized rat heart, the difference in the uptake between Ep LV and En LV was smaller. This suggests that the difference in the regional [125I]MIBG uptake might reflect different intravesicular uptake in the layers of the heart. To our knowledge, the low uptake in the endocardial layer was a new finding which seems to indicate a difference in innervation between the epicardial and endocardial layers of the left ventricle in the rat heart. Autoradiographic study also showed the low uptake of [125I]MIBG in the endocardial layer, while homogeneous perfusion was observed with thallium-201, supporting the tissue uptake study. Thus, the endocardial and epicardial layers of the left ventricle in the rat heart were considered to be differently innervated.

3-Iodobenzylguanidine↗
PubMed1993

Flow capacities of arterial grafts for coronary artery bypass grafting.

The flow capacities of arterial and saphenous vein grafts in 100 patients who had coronary artery bypass grafting were compared under exercise conditions by continuous ventricular function monitoring, which records serial beat-to-beat radionuclide data and calculates left ventricular ejection fractions every 20 seconds. Ejection fraction profiles during graded bicycle exercise were divided into four types. In type A, the ejection fraction continued to increase. In type B, the ejection fraction initially increased, but decreased during the late exercise stage. In type C, the ejection fraction did not change. In type D, the ejection fraction continued to decrease throughout exercise. A decrease in ejection fraction, observed in type B or D, is an early indicator of myocardial ischemia. Before operation, 10 patients showed type A, 30 type B, 11 type C, and 49 type D responses. After operation, 68 patients showed type A, 21 type B, and 11 type C responses. Patients were divided into three groups according the type of bypass graft. Group 1 included 21 patients with two arterial grafts and vein grafts; group 2, 61 patients with an internal thoracic artery graft and vein grafts; group 3, 18 patients with only vein grafts. All of the grafts were patent on angiography. Eight patients (38%) in group 1 and 13 (21%) in group 2 showed a postoperative type B response, but none of the patients in group 3 had a postoperative type B response (p < 0.02). Seven of 8 patients in group 1 with postoperative type B responses had only arterial grafts to the left-side coronary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Intense gallium-67 uptake in ovarian dysgerminoma.

In a patient with an ovarian dysgerminoma, intense uptake of gallium-67 citrate was demonstrated. This report indicates that dysgerminoma should be added to the list showing abnormal accumulation of gallium-67 citrate in the abdomen.

Adolescent↗
PubMed1993

123I-labelled BMIPP fatty acid myocardial scintigraphy in patients with hypertropic cardiomyopathy: SPECT comparison with stress 201Tl.

123I-labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) was performed in 17 patients with hypertrophic cardiomyopathy, and was compared with 201Tl exercise stress myocardial perfusion SPECT images. Fourteen patients showed asymmetrical hypertrophy, and three demonstrated apical hypertrophy. SPECT was performed 20 min and 3 h after injection of 111 MBq 123I-BMIPP at rest. Exercise stress 201Tl SPECT was performed at 10 min and 3 h after injection and was compared with BMIPP imaging. In 13 patients BMIPP accumulation in the hypertrophied area in the 20 min image was lower than that of 3 h 201Tl uptake. Interestingly, six patients demonstrated 201Tl redistribution in the region where the uncoupling of BMIPP uptake at 20 min and 201Tl accumulation at 3 h after exercise was observed. These findings suggest that impaired fatty acid metabolism or utilization in hypertrophic myocardium and ischaemia or impaired coronary flow reserve may be one of the causes of the abnormality of fatty acid accumulation.

Adult↗
PubMed1993

Evaluation of suspected malignant pulmonary lesions with 201Tl single photon emission computed tomography.

201Tl single photon emission computed tomography (SPECT) was evaluated in 170 patients suspected of having a malignant pulmonary lesion greater than 20 mm in diameter on the surgical specimen. Delayed SPECT (at 3 h after injection) visualized all of the 147 malignant pulmonary lesions and 16 of the 23 (69.6%) benign pulmonary lesions, and generally exhibited the lesion more clearly than the early SPECT images (at 15 min after injection). There was no significant difference in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) among the various histological groups except between the adenocarcinoma and large cell carcinoma groups (P < 0.05), and no difference was noted between the malignant and benign lesions. However, in retention index (degree of retention in the lesion) a significant difference was noted between the malignant and benign lesions (P < 0.01), although there was no significant difference in this index among malignant different histology groups. These results indicate that this method is useful for visualizing malignant pulmonary lesions greater than 20 mm in diameter to exclude the possibility of malignancy in the lesions when no abnormal 201Tl accumulation is observed. When the lesion shows abnormal 201Tl accumulation, the retention index seems to help differentiate malignant from benign lesions.

Adenocarcinoma↗
PubMed1993

Cytoimmunologic monitoring using DNA analysis in canine liver transplantation.

In this experiment, we evaluated the significance of flow cytometric DNA content measurement of circulating blood mononuclear cells in early detection of canine hepatic allograft rejection. In nonimmunosuppressed controls, the SG2M% of blood mononuclear cells significantly increased on days 5-6 after liver transplantation compared with the pretransplant values (P < 0.01). At the time of SG2M% elevation, microscopic examination of the graft revealed acute mild rejection. These changes in SG2M% and histological findings were observed one or two days earlier than biochemical changes indicative of liver injury. On the other hand, nonrejected cases under sufficient immunosuppression with cyclosporine or FK506 maintained low levels of SG2M% in comparison with the pretransplant values (P < 0.05). The rejecting cases under insufficient immunosuppression showed significantly elevated SG2M% (P < 0.05), and successful steroid pulse therapy provided to the recipients immediate normalization of SG2M% with histological restoration. Moreover, other complications such as pulmonary infection, peritonitis, and marasmus--rather than the rejection reaction--did not influence on SG2M%. These results led us to believe that flow cytometric DNA content measurement of blood mononuclear cells provides relevant and early information with respect to ongoing canine hepatic allograft rejection. The diagnostic value for differentiation between hepatic allograft rejection and infection of the transplant by hepatitic viruses needs further evaluation.

Animals↗
PubMed1993

[Evaluation of early kinetics of 123I-BMIPP in patients with ischemic heart disease].

Early kinetics of 123I-BMIPP was evaluated in 200 left ventricular myocardial segments from 10 patients with old myocardial infarction, employing dynamic SPECT. Dynamic SPECT acquisition was performed from 2 minutes to 14 minutes after injection of 123I-BMIPP. Conventional static SPECT with 123I-BMIPP (BM-S) at 20 min after injection and delayed image from stress 201Tl SPECT (Tl-RD) were visually evaluated by dividing each myocardial segment into the following four groups, NL (the segments with normal radioactivity in BM-S and Tl-RD), Tl < BM (the segments with reduced radioactivity in Tl-RD compared with BM-S), Tl > BM (the segments with reduced radioactivity in BM-S compared with Tl-RD) and Tl = BM < NL (the segments with equally reduced radioactivity in BM-S and Tl-RD). In the dynamic SPECT, washout rate (WR) from 2-4 to 12-14 minutes images was calculated. The WR of Tl > BM group (12.9 +/- 15.5% (mean +/- SD), 55 of 200 segments) was significantly higher than those of NL (-8.6 +/- 11.9%, 95 of 200 segments), Tl = BM < NL (-0.6 +/- 16.0%, 45 of 200 segments) and Tl > BM (-4.4 +/- 9.2%, 5 of 200 segments) groups. This high WR of Tl > BM group may reflect "back diffusion" from myocardium in early phase after injection of 123I-BMIPP.

Adult↗
PubMed1993

Myocardial perfusion imaging and dynamic analysis with technetium-99m tetrofosmin.

Technetium-99m tetrofosmin is a new myocardial perfusion imaging agent that accumulates rapidly and shows slow clearance from the myocardium. Dynamic acquisition and SPECT imaging were performed in a total of 26 patients. Using exercise-rest protocol, the single-photon emission computed tomography (SPECT) findings of 130 myocardial segments were classified as infarction, ischemia and partial filling and compared to those with 201Tl. Complete concordance of findings was obtained in 108 segments (83%) between images with 99mTc tetrofosmin and 201Tl. Partial filling was observed in 24 segments with 201Tl and 14 segments with tetrofosmin, showing a greater number of ischemic regions in 201Tl. However, in comparison with coronary arteriography (n = 19), overall sensitivity and specificity for detecting coronary artery stenosis (> or = 75%) was 15 of 25 (0.60) and 27 of 32 (0.84), respectively, which did not differ significantly from those of 201Tl, which was 18 of 25 (0.72) and 27 of 32 (0.84), respectively. Graphic analysis that assumes unidirectional transfer of the tracer was applied to initial dynamic changes and uptake constant k and distribution volume V were computed. Multiple vessel disease and congestive heart failure showed a low perfusion index (k/V), and may be used in this type of tracer with unidirectional uptake. This preliminary study in the clinical trial showed the usefulness of 99mTc tetrofosmin as a myocardial perfusion imaging agent.

Coronary Angiography↗
PubMed1993

[DNA analysis of peripheral blood mononuclear cells for early detection of hepatic graft rejection].

We evaluated the significance of flow cytometric DNA content measurement of peripheral blood mononuclear cells for early detection of hepatic allograft rejection. A total of 15 orthotopic liver transplantation was performed using canine model. Animals were divided in two groups consisting of 5 dogs as untreated controls, and administered cyclosporine (n = 6) or FK506 (n = 4). Blood mononuclear cells DNA contents were analyzed by Propidium iodine method using FACScan. In untreated controls (n = 5), SG2M% of the mononuclear cells value significantly elevated on day 5 or 6 to 15.6 +/- 0.7% (mean +/- SE) compared to pretransplantation value (10.2 +/- 0.6%) (p < 0.01). At the time of SG2M% elevation, microscopic examination of the graft revealed acute mild rejection. These changes in SG2M% and histological finding were observed one or two days earlier than biochemical changes indicative of liver injury. On the other hand, non-rejected case under sufficient immunosuppression, SG2M% remained low levels (3.8 +/- 1.1%) in comparison with pretransplant values (8.8 +/- 0.6%) (p < 0.05). The rejecting cases under insufficient immunosuppression, SG2M% significantly elevated to 13.6 +/- 1.3% (p < 0.01). When steroid pulse therapy was successfully performed, it subsequently decreased to 5.6 +/- 0.7% (p < 0.01), and histological rejection reaction was disappeared. We concluded that serial measurement of DNA content of peripheral blood mononuclear cells may serve as an useful means for monitoring the immunological status of hepatic recipients.

Animals↗
PubMed1993

[Assessment of congenital heart disease by a thallium-201 SPECT study in children: accuracy of estimated right to left ventricular pressure ratio].

The characteristics of correlation between the right-to-left ventricular systolic pressure ratios (RVp/LVp) and the thallium-201 right-to-left ventricular (201Tl R/L) count ratios was investigated in children with various congenital heart diseases. High-resolution three-headed SPECT system equipped with either parallel-hole or fan-beam collimators was used. In a total of 102 patients, the correlation between RVp/LVp and 201Tl R/L average count ratios was good in both planar (r = 0.89, p = 0.0001) and SPECT studies (r = 0.80, p = 0.0001). Quantitative analysis of myocardial uptake by SPECT demonstrated the characteristic pattern of each disease as well as the differences in the right ventricular overload types. When the linear regression analysis was performed in each heart disease, ventricular septal defect showed most excellent correlation. Complex heart anomalies also showed positive correlation (r = 0.51, p = 0.05) with RVp/LVp, and it can be used to estimate right ventricular pressure. After surgical treatment of tetralogy of Fallot and pulmonary stenosis, the decrease of 201Tl R/L count ratio was in accordance with improvement of right ventricular overload. We conclude that 201Tl SPECT study can be a good indicator for estimation of right ventricular pressure.

Adolescent↗
PubMed1992

Comparison of painful and painless left ventricular dysfunction recorded during ambulatory ventricular function monitoring in angina pectoris secondary to coronary artery disease.

Left ventricular (LV) function and the electrocardiogram of 55 patients with coronary artery disease and angina were monitored for a mean of 3.2 +/- 1.9 hours with an ambulatory LV function monitor. During the monitoring interval, patients performed daily activities such as sitting, walking, climbing stairs, and eating. Sixty episodes of transient reduction in ejection fraction of > 5% lasting > 60 seconds were observed in 24 patients; 13 episodes were associated with typical angina, but 47 were asymptomatic. Asymptomatic episodes had a shorter duration of ventricular dysfunction (116 +/- 49 vs 189 +/- 113 seconds; p < 0.05), and smaller increases in relative end-diastolic and end-systolic volumes (end-diastolic 0.9 +/- 5.4% vs 4.6 +/- 4.9% [p < 0.05], and end-systolic 21 +/- 11% vs 35 +/- 20% [p < 0.05]) than did symptomatic ones. When a subset of patients with both symptomatic and asymptomatic episodes were analyzed, similar results were observed: in asymptomatic episodes, duration was shorter (82 +/- 31 vs 200 +/- 110 seconds; p < 0.005), ejection fraction decrease was smaller (-7.3 +/- 2.6% vs -11.0 +/- 4.7%; p < 0.05), and end-systolic volume increase was smaller (23 +/- 12% vs 37 +/- 19%; p < 0.05). The data suggest that asymptomatic transient LV dysfunction is less severe and of shorter duration in patients with angina pectoris.

Angina Pectoris↗
PubMed1992

Initial hepatic metabolic function in canine liver and pancreas cluster transplantation.

In this study, initial hepatic metabolic function was evaluated by determining the arterial ketone body ratio (AKBR) and plasma amino acid concentrations in an experimental orthotopic combined hepatopancreatic transplantation (OHPT), and comparing the same values in orthotopic liver transplantation (OLT). In OHPT, AKBR decreased in the anhepatic phase and recovered to the preoperative value just 1 h after reperfusion. On the other hand, in OLT, the recovery of AKBR took 3 h after reperfusion with a significant difference compared to OHPT (P less than 0.05). Plasma amino acid levels, especially alanine and total free plasma amino acids increased in the anhepatic phase and recovered within 1 h of reperfusion in OHPT. However, they did not recover until 3 h after reperfusion in OLT. This rapid recovery of hepatic metabolic function in OHPT should be attributed to the order of reperfusion in which the reconstruction of arterial blood flow precedes that of portal blood flow. This model is useful for assessing the best way by which the grafted liver can for assessing the best way by which the grafted liver can control the timing, order, rate, and volume of blood that should be released.

Amino Acids↗
PubMed1992

Asymmetric abnormality of renal perfusion with symmetric function in aortic dissection.

Two cases of aortic dissection are presented in which discordance between renal perfusion and function has been demonstrated with Tc-99m DTPA. Renal perfusion on the affected side was decreased on blood flow imaging, whereas renal function, including parenchymal accumulation and excretion assessed by subsequent sequential imaging, were similar for both kidneys. These results suggest that blood flow imaging more readily demonstrates a unilateral renal abnormality in patients with aortic dissection.

Aortic Dissection↗
PubMed1992

Acute subendocardial infarction with diffuse intense Tc-99m PYP uptake and minimal Tl-201 abnormality.

Tc-99m PYP scintigraphy performed on a patient with severe anterior chest pain showed diffuse intense uptake with central decreased activity corresponding to the left ventricular cavity. Tl-201 myocardial perfusion scintigraphy at rest revealed a minimal perfusion abnormality with decreased apical uptake in the lateral view. Because of these findings, diffuse subendocardial infarction was suggested.

Acute Disease↗
PubMed1992

Long-term course and cardiac sympathetic nerve activity in patients with hypertrophic cardiomyopathy.

OBJECTIVE: To investigate the relation between regional myocardial sympathetic nerve activity and the electrocardiographic and cardiac functional changes in hypertrophic cardiomyopathy. DESIGN: A retrospective study to compare the findings of myocardial scintigraphy with iodine-123 metaiodobenzylguanidine (MIBG) and the serial electrocardiographic changes. SETTING: Myocardial scintigraphy was performed with iodine-123 MIBG and thallium-201 and single photon emission computed tomography (SPECT) in the division of nuclear medicine of Kanazawa University Hospital. Both SPECT studies were performed within a week. PATIENTS: 22 patients with hypertrophic cardiomyopathy classified according to their serial electrocardiographic changes--namely, 15 patients with an increase in or the appearance of a negative T wave (group A) and seven patients with a conduction disturbance or a decrease in or disappearance of the negative T wave (group B). The mean follow up period was 45 (range 12-143) months. RESULTS: Group B showed a high rate of decreased activity or defects in MIBG uptake compared with group A (p less than 0.005). The areas of decreased activity or defects corresponded with the hypertrophied portion of the left ventricular wall. Although the early myocardial uptake (MIBG: thallium ratio) was similar in both groups, the mean (SD) MIBG clearance rate was significantly higher (p less than 0.05) in group B (0.25 (0.17)) than in group A (0.10 (0.15)). CONCLUSION: Abnormalities of regional myocardial sympathetic nerve activity may be important in patients with hypertrophic cardiomyopathy and suspected progression of myocardial damage.

3-Iodobenzylguanidine↗