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Biomedical subjects

J Taki

Publications and source records attributed to J Taki.

At least 91 records · Page 5Linked to original sources
PubMed1996

Liver transplantation for hepatocellular carcinoma: consideration from the findings on autopsy.

Extrahepatic spread of hepatocellular carcinoma was investigated in twenty autopsy cases with unresected hepatocellular carcinoma to define the appropriate patient selection criteria for liver transplantation. Diagnosis of extrahepatic spread of cancer by diagnostic imaging was not easy, and unsatisfactory prognosis after liver transplantation in patients with hepatocellular carcinoma might have been attributed to the high incidence of extrahepatic occult foci of cancer. All patients with multiple nodular, massive and diffuse tumor had extrahepatic spread of cancer. Only patients with a single nodular type tumor, no larger than 30 mm in diameter, had no extrahepatic metastasis, and these patients are the preferred candidates for liver transplantation.

Aged↗
PubMed1996

The Ilizarov method in the management of giant-cell tumours of the proximal tibia.

We have used the Ilizarov technique for the management of subarticular defects after the excision of giant-cell tumours in the proximal tibia in five patients. The defect was reconstructed with a segment of 5 to 6 cm obtained from the diaphysis of the affected tibia and by autogenous bone graft from the iliac crest. The newly developed defect in the diaphysis was reconstructed by distraction using the Ilizarov apparatus. Bone grafting at the docking site was performed soon after positioning the bone segments. The mean length of the bone defect was 5.7 cm and the mean duration of external fixation was 233 days. The relative blood flow in the leg measured by 99mTc angiography increased by 1.7 to 2.3 times that of the control level during distraction and consolidation. When seen at a mean of 43 months all patients showed a normal range of motion in the knee and ankle with no collapse of the articular surfaces.

Adolescent↗
PubMed1996

[Evaluation of pulmonary perfusion in a patient with agenesis of the left pulmonary artery: usefulness of radionuclide angiography].

We reported a case with agenesis of the left pulmonary artery, in which radionuclide angiography with 99mTc-HSA and time activity curve (TAC) were useful in evaluating pulmonary perfusion in the effected lung. The case involved a 32-year-old male, who underwent nuclear medicine examination including 99mTc-MAA scanning, 81mKr scanning and 99mTc-HSA angiography. 99mTc-MAA and 81mKr scanning showed the perfusion defect and decreased ventilation in the effected lung, respectively. On the other hand, the delayed images of 99mTc-HSA angiography showed the existence of perfusion in the effected lung, although the early images showed the perfusion defect in the same lung. The TAC whose region of interest was placed on the hilus showed that the effected lung was gradually filled with the blood flow through the collateral pathways. In addition, the ratio of area under the TAC on the contralateral lung versus the effected lung was 4.6, while the volume ratio of the contralateral lung versus the effected lung obtained from X-ray CT images was 2.7. Therefore, it was suggested that the perfusion per volume in the effected lung was decreased, compared with that in the contralateral lung. It was concluded that 99mTc-HSA angiography was useful in evaluating the perfusion of the effected lung in a patient with agenesis of the left pulmonary artery.

Adult↗
PubMed1996

Early and delayed technetium-99m-tetrofosmin myocardial SPECT compared in normal volunteers.

UNLABELLED: This study was performed to test the feasibility of early SPECT imaging with 99mTc-tetrofosmin with the presence of high hepatic activity. METHODS: Thirteen normal volunteers were injected 600-740 MBq of 99mTc-tetrofosmin at rest and were imaged at 10 min and 1 hr after injection. The SPECT images were reconstructed for 180 degrees 360 degrees data. The early and delayed SPECT and anterior planar projection images were analyzed. RESULTS: After excluding one subject because of high hepatic activity overlapping to the myocardium, 4 of 12 subjects (33%) had abnormal scans with reduced uptake in the inferior wall on the early 180 degrees SPECT image. In contrast, only one (8%) showed equivocally reduced uptake on the 360 degrees SPECT image. In the delayed images, all subjects had a normal 180 degrees and 360 degrees SPECT scan. Quantitative data showed reduced regional activities in the inferior wall on the early SPECT scan, especially in the 180 degrees data. There were no changes in the mean anterior-to-inferior ratio in the anterior planar projection images over time, suggesting that the reduced activity in the early SPECT images reflected an artifactual effect. CONCLUSION: Our data indicate that it would be best to perform late imaging in patients with suspected coronary artery disease using 99mTc-tetrofosmin.

Adult↗
PubMed1995

The enhanced immunosuppressive efficacy of newly developed liposomal FK506 in canine liver transplantation.

Local delivery of immunosuppressants to the graft and lymphatic tissue is a potential appraoch to enhance the immunosuppressive efficacy and to alleviate systemic adverse effects simultaneously. By taking advantage of this method, we developed liposomal FK506. Previous pharmacokinetic study of liposomal FK506 indicated increased FK506 levels in the liver and spleen. Because the liver is the site of the allograft in liver transplantation and the spleen is a major lymphoid tissue, we hypothesized that liposomal FK506 would increase immunosuppressive efficacy in liver transplantation. We evaluated this hypothesis in a canine model. Orthotopic liver transplantation was performed using beagle dogs, and the recipients were divided into the following groups: group I, no immunosuppression (n = 5); group II, 0.05 mg/kg/day of FK506 i.v. in a commercially available i.v. formulation for 14 days (n = 5); and group III, 0.05 mg/kg/day of FK506 i.v. in a liposomal formulation for 14 days (n = 5). All recipients in group I died within 2 weeks. Recipients in group II died within 33 days. In contrast, three recipients in group III survived for more than 200 days (P < 0.05 versus group I or group II). In DNA analysis, splenocyte proliferation activity in group III was significantly suppressed in comparison with group II. These results suggest that liposomal FK506 markedly increase the immunosuppressive efficacy of FK506 in liver transplantation. A local immunosuppressive effect in the grafted liver and significant suppression of splenocyte proliferation might contribute to enhancement of the immunosuppressive efficacy of liposomal FK506.

Animals↗
PubMed1995

Successful management of portal hypertension following artificial arterioportal shunting: report of a case.

A 63-year-old woman diagnosed as having hepatic hilar cancer underwent an extended left lobectomy of the liver with excision of the right hepatic artery which was involved by the tumor. Because the hepatic artery could not be reconstructed by direct anastomosis, an artificial arterioportal (A-P) shunt was constructed between the common hepatic artery and the portal vein. However, 4 weeks after the operation, portal hypertension with severe esophageal varices developed. Under the diagnosis of portal hypertension caused by excessive blood flow from the A-P shunt, coil embolization of the common hepatic artery was performed using an angiographic technique, following which the esophageal varices completely disappeared. This case demonstrates that portal hypertension after A-P shunting can be effectively treated with coil embolization.

Angiography↗
PubMed1995

Impairment of regional fatty acid uptake in relation to wall motion and thallium-201 uptake in ischaemic but viable myocardium: assessment with iodine-123-labelled beta-methyl-branched fatty acid.

In coronary artery disease, discrepancy in the uptake of thallium-201 and of methyl-branched fatty acid at rest has been described. The purpose of this study was to evaluate iodine-123 labelled beta-methyl-branched fatty acid (BMIPP) myocardial uptake and wall motion at rest in segments with stress-induced ischaemia identified by stress 201Tl tomography in patients with chronic coronary artery disease. 123I-BMIPP myocardial tomography was performed at rest and was compared with the findings of exercise-reinjection 201Tl tomography in 45 patients with chronic coronary artery disease. Regional wall motion was evaluated by contrast left ventriculography in 36 patients. Among 237 segments with reversible 201Tl defects, equally decreased uptake on both reinjection 201Tl and BMIPP images was observed in 93 (39%), more severely decreased uptake of BMIPP in 118 (50%) and more severely decreased uptake of reinjection 201Tl in 26 (11%). On the other hand, among 90 segments with non-reversible 201Tl defects, each pattern was observed in 71 (79%), 6 (7%) and 13 (14%) segments, respectively. When comparing the ischaemic segments with and without more severely reduced uptake of BMIPP than of reinjection 201Tl, wall motion was impaired to a greater extent in the segments with more severely reduced uptake of BMIPP than of reinjection 201Tl [severe hypo- or dyskinesis was present in 64 (70%) of 91 segments and in 24 (22%) of 110 segments, respectively, P<0.005]. In patients with chronic coronary artery disease, resting fatty acid uptake was frequently more reduced than reinjection 201Tl in the segments with stress-induced ischaemia, while in most of the fixed perfusion defects BMIPP and reinjection 201Tl uptake decreased concordantly. In ischaemic myocardium, wall motion was impaired to a greater extent in those segments which showed more severely reduced uptake of BMIPP than of reinjection 201Tl. In ischaemic but viable myocardium, discordant BMIPP uptake less than reinjection 201Tl uptake may indicate metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities. In conclusion, the combination of resting BMIPP and stress-reinjection 201Tl imaging may provide information on metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities.

Adult↗
PubMed1995

Intense accumulation of Tc-99m MDP and Ga-67 in multiple periapical cemental dysplasia.

A case of multiple periapical cemental dysplasia is presented and intensive accumulation of Tc-99m MDP and Ga-67 is described. A 53-year-old woman was admitted with an intermittent pain and swelling of the left buccal region. The radiograph showed multiple sclerotic masses covering entire periapical regions of the teeth, in both the maxilla and mandibula. Biopsy of the maxilla facilitated a definitive diagnosis of multiple periapical cemental dysplasia.

Dental Cementum↗
PubMed1995

Ki-ras mutations and p53 protein expressions in intrahepatic cholangiocarcinomas: relation to gross tumor morphology.

BACKGROUND & AIMS: We previously reported that intrahepatic cholangiocarcinomas (ICCs) can be divided into three categories according to their gross appearance with possible links to biological behavior. Ki-ras and p53 gene alterations are thought to be involved in early and late phases of carcinogenesis, respectively. This study was performed to investigate the relationship between the gross appearance and genetic alterations of ICC. METHODS: We examined 21 patients with ICC. Ki-ras point mutations were assessed by polymerase chain reaction/single-strand conformation polymorphism methods followed by direct DNA sequencing. Expressions of p53 protein were immunohistochemically assessed. RESULTS: Ki-ras point mutations were found in 10 patients (48%), and expressions of p53 protein were detected in 4 (19%). Applying the gross classification that we previously proposed, Ki-ras mutations were prominent in the periductal extension type (4 of 6; 67%) and the spicula-forming type (6 of 10; 60%). On the other hand, none of the five mass-forming-type tumors harbored Ki-ras mutations. Expressions of p53 protein did not show any clear association with gross appearance. CONCLUSIONS: Ki-ras gene alterations may be involved in the cholangiocarcinogenesis of periductal extension and spicula-forming but not mass-forming types, suggesting that the underlying processes of development are different.

Adult↗
PubMed1995

Effects of short-term aminophylline administration on cardiac functional reserve in patients with syndrome X.

OBJECTIVES: This study sought to evaluate the effect of adenosine receptor blockade by aminophylline on cardiac functional reserve in patients with syndrome X. BACKGROUND: Aminophylline may have a potentially antiischemic effect through the inhibition of adenosine and, thus, the coronary steal phenomenon in patients with syndrome X. METHODS: A single-blind, placebo-controlled study of an intravenous infusion of aminophylline (6 mg/kg body weight over 15 min) or placebo (20 ml of saline solution over 15 min) was performed during continuous radionuclide monitoring of left ventricular ejection fraction in 12 patients performing supine bicycle ergometric exercise. RESULTS: Aminophylline increased exercise time (aminophylline 400 s vs. placebo 355 s, p < 0.01), decreased degree of ST segment depression (aminophylline 1.6 mm vs. placebo 2.4 mm, p < 0.01) and either abolished (seven patients) or diminished (five patients) chest pain during exercise. Aminophylline also increased left ventricular ejection fraction at rest (aminophylline 66.5% vs. placebo 62.3%, p < 0.05) but did not improve its deterioration at peak exercise (aminophylline 60.1% vs. placebo 56.6%, p = NS) or shorten the abnormally prolonged interval between the end of exercise and the overshoot (aminophylline 115 s vs. placebo 130 s, p = NS). CONCLUSIONS: Aminophylline infusion increases ischemic threshold and prolongs exercise duration in patients with syndrome X. It is hypothesized that aminophylline acts by inhibiting the coronary steal phenomenon through adenosine receptor blockade. It does not improve the deterioration in left ventricular function at peak exercise or the delayed response in ejection fraction in the recovery period, presumably because the beneficial effects of aminophylline that result from the redistribution of coronary blood flow are limited.

Aminophylline↗
PubMed1995

Variable portal circulation from inferior mesenteric vein assessed by per-rectal radionuclide administration.

The intrahepatic distribution of radioactivity after the per-rectal administration of 201T-chloride and/or 99Tcm-pertechnetate was investigated in 177 studies in 149 patients with no liver disease or diffuse liver disease and compared with that of 99Tcm-stannous (99Tcm-Sn) colloid scintigrams. The patients were classified into two groups: distribution of intrahepatic radioactivity of 201Tl and/or 99Tcm-pertechnetate scintigrams similar to (homogeneous) or different from (heterogeneous) that of 99Tcm-Sn-colloid scintigrams. The heterogeneous group was divided into three subgroups: increased radioactivity of the right lobe (right dominant pattern), increased radioactivity of the left lobe (left dominant pattern) and uneven distribution of radioactivity in both lobes (uneven pattern). Of the 80 patients in whom the studies were performed in the supine position at rest, 14 (17.5%) showed a heterogeneous pattern (8 right dominant, 4 left dominant, 2 uneven) and 66 (82.5%) a homogeneous pattern. In the 97 patients allowed free body movement, 6 (6.2%) showed a heterogeneous (1 right dominant, 5 left dominant) and 91 (93.8%) a homogeneous pattern. A significant difference in the incidence of heterogeneous distribution between the resting and free body movement groups was found (P < 0.05). One patient with a left dominant pattern after free body movement with 201Tl showed a right dominant pattern at rest in the 99Tcm-pertechnetate study. It is concluded that a heterogeneous intrahepatic distribution of inferior mesenteric vein blood is sometimes observed and that the distribution of portal vein blood flow seems to be affected by the patient's positioning and free body movement.

Administration, Rectal↗
PubMed1995

Comparison of 99Tcm-pyrophosphate, 201T1 perfusion, 123I-labelled methyl-branched fatty acid and sympathetic imaging in acute coronary syndrome.

Among a group of patients (n = 15) with acute coronary syndrome, the results of using two new myocardial radiopharmaceuticals--123I-labelled 15-(p-iodo-phenyl)-3,R,S-methylpentadecanoic acid (BMIPP) and 123I-meta-iodobenzyl guanidine (MIBG)--were compared with dual 201Tl/99Tcm-pyrophosphate (Tl-PYP) imaging using single photon emission tomography (SPET). Defect scores were evaluated on a segment-by-segment basis for a total of 270 segments. For the 201Tl, BMIPP, and early and delayed MIBG studies, the mean (+/- S.D.) sums of defect scores were 9 +/- 8, 18 +/- 9, 22 +/- 12 and 29 +/- 9, respectively, revealing significantly higher scores for BMIPP and MIBG than 201Tl (P < 0.005). This was the case irrespective of various functional conditions, such as successful recanalization, failure of coronary angioplasty or restenosis. The culprit coronary artery was best identified using BMIPP, while MIBG SPET showed the most extensive defects. Normal perfusion with decreased BMIPP and MIBG uptake was frequently observed and associated with hypokinesis. 123I-BMIPP and MIBG are more sensitive for the detection of damaged myocardium, and the difference between perfusion and metabolism seems to reflect myocardial stunning.

3-Iodobenzylguanidine↗
PubMed1995

Comparison of 99Tcm-sestamibi and 201Tl-chloride to estimate right ventricular overload in children.

To evaluate right ventricular overload in paediatric patients with congenital cardiac disease (n = 25), the uptakes of 201Tl and 99Tcm-sestamibi (99Tcm-MIBI) were compared. 99Tcm-MIBI showed a clearer myocardial border and better contrast between the myocardium and ventricular cavity. Although hepatic activity may influence right ventricular myocardial activity, it did not have a significant effect on the quantitative data of myocardial uptake. The right ventricle-to-background (RV/BG) ratio and left ventricle-to-background (LV/BG) ratio were lower with 99Tcm-MIBI than with 201Tl, and the RV/LV count ratio was also significantly lower in the 99Tcm-MIBI study. The parameters of the RV/LV count ratios showed good correlations between the 201Tl and 99Tcm-MIBI studies. The RV/LV pressure ratio was estimated using the formula: RV/LV pressure ratio = 0.99 (RV/LVav) + 0.02 (R = 0.90, P < 0.0001). To estimate RV overload or the RV/LV pressure ratio scintigraphically, we conclude that 99Tcm-MIBI be used instead of 201Tl. 99Tcm-MIBI studies are a good adjunct to perfusion studies when estimating RV pressure.

Child, Preschool↗
PubMed1995

Utility of iodine-123-BMIPP in the diagnosis and follow-up of vasospastic angina.

UNLABELLED: Myocardial damage caused by vasospastic angina (VSA) may be detected by [123I]BMIPP, a beta-methyl-branched fatty acid. We investigated whether BMIPP could be used in the diagnosis and follow-up of patients with VSA. METHODS: Thirty-two patients with VSA were studied with resting BMIPP-SPECT in comparison to stress perfusion imaging with either 201Tl or 99mTc-MIBI. During coronary arteriography, spasm was induced by provocative testing with acetylcholine or ergonovine, and only total or subtotal occlusion was considered positive. Decreased BMIPP uptake was semiquantitatively evaluated segmentally aided by polar map display. RESULTS: Reduced BMIPP uptake was observed in 25 of 32 patients (78%), with complete or partial agreement between the BMIPP abnormality and coronary territory seen in 23 patients (72%). In contrast, a perfusion abnormality was seen in only 10 patients (31%). In the repeat BMIPP study (n = 23) during the follow-up period (average 206 days), 11 of 14 patients who showed BMIPP improvement also had improved angina attacks. Conversely, two of nine patients with nonimproved BMIPP showed improved symptoms (p < 0.05). CONCLUSION: BMIPP can detect myocardial injury associated with VSA and may be useful in monitoring response to treatment.

Acetylcholine↗
PubMed1995

Myocardial viability assessment with technetium-99m-tetrofosmin and thallium-201 reinjection in coronary artery disease.

UNLABELLED: Exercise-rest 99mTc-tetrofosmin myocardial perfusion images with a 2-day protocol was compared to exercise-redistribution-reinjection 201Tl images to assess the ability of 99mTc-tetrofosmin to detect viable myocardium. METHODS: We studied 25 patients with coronary artery disease and regional or global left ventricular dysfunction. Myocardial SPECT images with 99mTc-tetrofosmin were obtained 10 min after injection during exercise and 1 and 3 hr after rest injection. Within 1 wk of the 99mTc-tetrofosmin study, exercise-redistribution-reinjection 201Tl SPECT imaging was performed. RESULTS: Visual analysis demonstrated concordance between 201Tl and 99mTc-tetrofosmin imaging for defect reversibility in 126 of 209 segments (60%), with initial defects on both exercise 201Tl and 99mTc-tetrofosmin images. In the remaining discordant 83 segments (40%), 73 (88%) appeared nonreversible on 99mTc-tetrofosmin imaging but were reversible on 201Tl imaging. CONCLUSION: On the basis of defect reversibility by visual analysis, exercise-rest 99mTc-tetrofosmin imaging underestimates myocardial viability compared to 201Tl reinjection imaging. The identification of viable myocardium with both 99mTc-tetrofosmin and 201Tl can be greatly enhanced to a similar degree if the severity of reduction in activity within nonreversible defects is considered. These two agents may provide comparable information about myocardial viability by quantitative analysis of defect severity.

Coronary Disease↗
PubMed1995

Improved myocardial fatty acid utilization after percutaneous transluminal coronary angioplasty.

Exercise-reinjection 201Tl imaging and resting 20-min and 3-hr BMIPP imaging were performed before and 4 mo after percutaneous transluminal coronary angioplasty (PTCA) in a patient with effort angina. Before PTCA, exercise 201Tl imaging showed decreased 201Tl activity in the septal wall, with significant fill-in on the reinjection 201Tl image. The resting 20-min BMIPP image showed decreased activity in the septal wall, with a slight redistribution on the 3-hr BMIPP image. The 201Tl and BMIPP images 4 mo after PTCA showed significant improvement in the 201Tl pattern and BMIPP uptake in the septal wall with no abnormally decreased activities.

Aged↗