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Biomedical subjects

T Toyama

Publications and source records attributed to T Toyama.

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

The level of mRNA transcribed from psaL, which encodes a subunit of photosystem I, is increased by cytokinin in darkness in etiolated cotyledons of cucumber.

A cDNA clone for an mRNA whose level increased within 2 h of the start of treatment with N6-benzyladenine in etiolated cotyledons of cucumber was isolated by differential hybridization. The cDNA was homologous to psaL, which encodes subunit XI (PSI-L) of photosystem I. The accumulation of psaL mRNA was specifically induced by cytokinins or light.

Amino Acid Sequence↗
PubMed1996

Evaluation of cardiac sympathetic nervous function by 123I-metaiodobenzylguanidine scintigraphy in insulin-treated non-insulin dependent diabetics with hypoglycemia unawareness.

The association between the lack of adrenergic symptoms during hypoglycemia and myocardial 123I-metaiodobenzylguanidine (MIBG) accumulation was investigated in 12 insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) patients who had no evidence of heart disease. These patients were divided into 2 groups according to the presence (group A) or absence (group B) of adrenergic symptoms during hypoglycemia. Autonomic function tests revealed significantly severe autonomic dysfunction in group B compared to that in group A. Insulin infusion test indicated no significant difference in the catecholamine response between the two groups. 123I-MIBG scintigraphy showed that the heart/mediastinum ratio of MIBG uptake was significantly lower, and scintigraphic defect was greater in group B than in group A. There were no significant differences in the washout rate between the two groups. These results suggested that the lack of adrenergic symptoms during hypoglycemia may be associated with cardiac sympathetic nervous dysfunction in insulin-treated NIDDM patients, and this dysfunction is mainly due to cardiac sympathetic denervation.

3-Iodobenzylguanidine↗
PubMed1996

[Molecular analysis of the estrogen receptor (ER) gene in association with ER negativity in breast cancer].

DNA from ninety-eight primary breast cancer biopsies has been examined for loss of heterozygosity (LOH). Thirteen of seventy-two informative cases (18.1%) were positive for LOH, which correlated with age at operation but not with ER status. This result suggests that LOH of the ER gene does not have an important role in the lack of ER function in breast cancer tissues. Thirteen breast cancers with ER negative/progesterone receptor (PgR) positive were screened for mutation analysis of the ER gene using single strand conformational polymorphism (SSCP). We found 2 polymorphisms in codon 10 (C to G) codon 325 (C to T), although neither germline nor somatic mutation was detected. Since the sequence variant of codon 325 tends to be more frequently seen in ER negative/PgR negative breast cancer patients than non-cancer control patients, it is suggested that this polymorphism was related to negativity and function of ER in breast cancer tissues.

Breast Neoplasms↗
PubMed1996

[The regional wall motion and the myocardial fatty acid metabolism at hibernating myocardium].

To evaluate the regional wall motion and the myocardial fatty acid metabolism at hibernating myocardium after revascularization (PTCA or CABG), we performed dual SPECT with 201Tl and 123I-beta-methyliodophenyl-pentadecanoic acid (BMIPP), and left ventriculography (LVG) in 34 patients with coronary artery disease before and 3 to 4 months after revascularization. In the SPECT, regional tracer uptake was estimated qualitatively (visual) and quantitatively (% uptake). Regional wall motion was estimated qualitatively (visual) and quantitatively (shortening fraction). At the 78 hibernating areas, the improvement of regional wall motion was more significantly (p < 0.05) correlated with that of regional tracer uptake of 123I-BMIPP (r = 0.63) than 201Tl (r = 0.39), and also correlated with the improvement of the difference between 201Tl and 123I-BMIPP regional uptake (r = 0.36). These results suggest that the improvement of wall motion at hibernating myocardium is more significantly correlated with the improvement of 123I-BMIPP than 201Tl uptake after revascularization.

Adult↗
PubMed1995

Pathogenesis of thymolipoma: report of three cases.

Three case reports of thymolipoma are herein presented. One patient presented with myasthenia gravis, while the other patients were asymptomatic. The tumors in our cases all had histopathologically different features: case 1, lipoma of the thymus; case 2, involuted thymic hyperplasia; and case 3, typical thymolipoma. The histopathological findings of thymolipoma are discussed in the context of the pathogenesis of thymolipoma.

Child, Preschool↗
PubMed1995

Usefulness of dipyridamole-thallium imaging in 257 patients with atherosclerotic vascular disease.

We evaluated the usefulness of dipyridamole-thallium imaging for the detection of ischaemic heart disease in 257 patients with atherosclerotic vascular disease (80 patients with arteriosclerosis obliterans, 81 patients with aneurysm of the abdominal aorta, 60 patients with aneurysm of the thoracic aorta and 36 patients with dissecting aortic aneurysm). Clinical evidence of ischaemic heart disease was found in 69 of 257 (27%) patients, including 32 patients with arteriosclerosis obliterans, 23 with aneurysm of the abdominal aorta, 9 with aneurysm of the thoracic aorta and 5 with dissecting aortic aneurysm. Dipyridamole-thallium imaging identified myocardial ischaemia in 49 of 69 (71%) patients with clinical evidence of ischaemic heart disease. Dipyridamole-thallium imaging showed positive results in 67 of 81 (83%) patients with aneurysm of the abdominal aorta. In patients with no clinical evidence of ischaemic heart disease, the results of dipyridamole-thallium imaging were positive in 39 of 188 (21%) patients. Dipyridamole-thallium imaging was positive in 90 of the 257 (35%) patients as a whole. When we combined the patients with positive dipyridamole-thallium imaging with those with negative dipyridamole-thallium imaging but who had clinical evidence of ischaemic heart disease, 42% of all patients had evidence of ischaemic heart disease. Our findings suggest that atherosclerotic vascular disease is strongly associated with ischaemic heart disease and that dipyridamole-thallium imaging is useful for the detection of ischaemic heart disease.

Aged↗
PubMed1995

Myocardial uptake of an iodinated branched fatty acid analog, assessed by SPECT, may detect metabolic derangement of the myocardium in diabetic patients with coronary heart disease.

The clinical implications of single-photon emission computed tomography using both a beta-methyl-branched fatty acid analog, 123I-15-(p-iodophenyl)-3-methyl-pentadecanoic acid (BMIPP), and thallium-201 (201Tl) were assessed in 30 patients with myocardial infarction (MI), 8 diabetics, 4 patients with impaired glucose tolerance, and 18 nondiabetic patients. Discordant decreases in BMIPP uptake, as compared with 201Tl uptake, in diabetic patients were significantly (p < 0.01) more frequent than in nondiabetic patients. The left ventricular (LV) ejection fraction in diabetics was significantly (p < 0.05) reduced and the LV diastolic dimension was significantly increased (p < 0.01), as compared with those in nondiabetic subjects. Analysis of peripheral blood showed no significant differences among the three test groups in metabolic abnormality. A discordant decrease in BMIPP uptake, as compared with Tl uptake, in cardiac tomography may indicate a metabolic derangement of the myocardium in diabetic patients with MI.

Adenosine Triphosphate↗
PubMed1995

[Usefulness of 123I-MIBG and 123I-BMIPP myocardial scintigraphy for detecting coronary artery disease and for evaluating left ventricular function].

We evaluated the diagnostic value of 123I-metaiodobenzylguanidine (MIBG) and 123I-labeled beta-methyliodophenyl pentadecanoic acid (BMIPP) myocardial SPECTs for evaluating coronary artery disease and left ventricular function, in comparison with the diagnostic value of 201Tl (Tl) SPECT. For forty-nine patients with coronary artery disease, resting MIBG and BMIPP SPECTs were performed to detect coronary artery stenosis, compared with the diagnostic value of exercise Tl. Left ventricular ejection fraction and regional wall motion were compared with the total US (TUS) and regional US (RUS) of resting MIBG and BMIPP SPECTs, and in turn, compared with resting Tl SPECT. The sensitivity of resting BMIPP SPECT for detecting coronary artery stenosis was lower, and the specificity of resting MIBG SPECT was lower than the other two methods. The accuracy of resting MIBG SPECT for evaluating coronary lesions was nearly the same as the accuracy of exercise Tl, but higher than that of BMIPP SPECT. Left ventricular ejection fraction was well correlated with TUS of resting MIBG SPECT (r = 0.80), resting BMIPP SPECT (r = 0.77), and resting Tl SPECT (r = 0.68). Regional wall motion was most correlated with RUS of resting BMIPP SPECT, compared with that of resting Tl and MIBG SPECTs. These data suggest that resting MIBG SPECT is useful for detecting coronary artery disease and that resting BMIPP SPECT is valuable in evaluating regional left ventricular function.

3-Iodobenzylguanidine↗
PubMed1995

[Study on prognostic factors in twenty-five patients with myelodysplastic syndrome].

Twenty-five consecutive patients with myelodysplastic syndrome (MDS) were followed in the Second Department of Internal Medicine, Miyazaki Medical School from 1984 to 1993. The diagnosis of MDS was morphologically based on the criteria of FAB. At the time of diagnosis, 9 patients had refractory anemia (RA), 1 had RA with ring sideroblasts (RARS), 6 had RA with excess blasts (RAEB), 6 had RAEB in transformation (RAEB-t), and 3 had chronic myelomonocytic leukemia (CMMoL). Prognostic factors involved in survival times and progression to leukemia were analyzed in these patients; FAB classification of MDS, age, sex, peripheral blood cell counts, bone marrow examination, karyotype, numbers of blasts. None of these prognostic factors had a significant effect on the prognosis of MDS patients. Study of the therapeutic effects on MDS patients revealed no significant increase of survival time in treated MDS patients compared to non-treated patients. Further, no significant difference in survival time was found between MDS patients treated with or without anticancer drugs. These results indicated that MDS patients were pathologically and therapeutically heterogeneous.

Aged↗
PubMed1995

[Prognostic significance of 123I-metaiodobenzylguanidine scintigraphy in dilated cardiomyopathy].

The prognostic factor was identified by performing 123I-Metaiodobenzylguanidine (MIBG) myocardial scintigraphy on 17 patients with dilated cardiomyopathy (DCM). During 5 years period, 9 patients had cardiac events, four of whom died, six were admitted due to heart failure and five had ventricular tachycardiac events. At the starting point, we collected rest early and 3-hr-delayed MIBG SPECT along with rest 201T1 (T1) SPECT. In the SPECT, regional tracer uptake was scored using 4-grades defect score (0 = normal to 3 = uptake-defect), and summed up to total defect score (TDS). At the same time, we estimated left ventricular end-diastolic dimension/body surface area (LVDd/BSA), end-systolic dimension/body surface area (LVDs/BSA) and left ventricular ejection fraction (LVEF) by echo-cardiography, pulmonary arterial wedge pressure (PAWP) and New York Heart Association (NYHA) symptom class. We compared the clinical and hemodynamic parameters between the patients with cardiac events (group A) and the other patients (group B). TDS of delayed MIBG SPECT (p < 0.001), TDS of early MIBG SPECT (p < 0.05), TDS of T1 SPECT (p < 0.01), LVDd/BSA (p < 0.01), LVDs/BSA (p < 0.001) and NYHA class (p < 0.05) of group A were significantly larger than those of group B. But, LVEF of group A was significantly less than that of group B (p < 0.01). On multivariate analysis, the following parameters were independent predictors of cardiac events: TDS of delayed MIBG SPECT (p < 0.001), PAWP (p = 0.0124) and LVDd/BSA (p = 0.0026). These data suggest that delayed MIBG scintigraphy is thought to be important to predict cardiac events in patients with DCM.

3-Iodobenzylguanidine↗
PubMed1995

Cytokinin induces a rapid decrease in the levels of mRNAs for catalase, 3-hydroxy-3-methylglutaryl CoA reductase, lectin and other unidentified proteins in etiolated cotyledons of cucumber.

Large-scale differential hybridization was performed to examine rapid changes in gene expression caused by a phytohormone, cytokinin, in etiolated cotyledons of cucumber (Cucumis sativus L.). We isolated 86 cDNA clones for mRNAs whose levels decreased within 2 h of the start of treatment with N6-benzyladenine (BA). Partial nucleotide sequences showed that some of the cDNAs were homologous to those for catalase, 3-hydroxy-3-methylglutaryl CoA reductase (HMGR) and a lectin. This is the first report that the levels of the mRNAs for those proteins are regulated by a cytokinin in darkness. Together with previous results [Teramoto et al. (1993) Physiol. Plant. 87: 584, (1994) Planta 193: 573, (1995) Planta 196: 387], the present study suggests that the cytokinin act to lower the levels of mRNAs transcribed from various genes in etiolated cotyledons.

Adenine↗
PubMed1994

Evaluation of short axial blood flow pattern in thoracic descending aorta by use of tagging cine magnetic resonance.

The authors, for the first time, evaluated the short axial blood flow profile by using tagging cine magnetic resonance (MR). Cine MR was performed on 15 healthy volunteers aged 51.5 +/- 23.1 (SD) years. The transverse plane of the thoracic descending aorta was imaged at the middle level of the left ventricle. Two or four radial tags, whose thickness was 3 mm width each, were established to the short axial image of the descending aorta at 2 msec and 300 msec following the R wave of the subjects' QRS complex on the electrocardiogram. They observed the flow patterns and measured the rotating flow velocity of the thoracic descending aorta in early systole and late systole from the following formula: v = d/t, (v = velocity, d = displacement of tags over the interval, t = time interval between the time of presaturation and the time of imaging). In the short axial image of the descending aorta, 13 subjects showed the clockwise rotation of tags in the supine position from the foot side view. Flow image of the other 2 subjects showed as undefined. Rotating flow velocity was 1.63 +/- 0.88 cm/sec in early systole and was 1.37 +/- 1.11 cm/sec in late systole. Tagging cine MR is useful to evaluate the blood flow profile in the thoracic descending aorta.

Adult↗
PubMed1994

Cloning and sequence analysis of a plasmid-encoded 2-haloacid dehalogenase gene from Pseudomonas putida No. 109.

The 2-haloacid dehalogenase of Pseudomonas putida No. 109 was mediated by a 74-kb conjugative plasmid, which was transferred by mating into Pseudomonas and Escherichia coli and there expressed the dehalogenase. A 2.8-kb EcoRI-fragment generated from the plasmid was cloned and sequenced. The dehalogenase gene (dehH109) was identified by comparison with the N-terminal amino acid sequence and the molecular weight of the enzyme protein. The gene dehH109 coded for a 224-amino acid protein of M(r) 25,231, which showed significant homology to the other four L-specific 2-haloacid dehalogenases from Pseudomonas sp. CBS3, P. putida AJ1, and Xanthobacter autotrophicus GJ10 and also to the haloacetate dehalogenase H-2 from Moraxella sp. strain B, but no homology with another haloacetate dehalogenase H-1 and the D-specific 2-haloacid dehalogenase from P. putida AJ1.

Amino Acid Sequence↗
PubMed1994

[Myocardial washout of 99mTc-hexakis-2-methoxy isobutyl isonitrile (99mTc-MIBI) at exercise myocardial scintigraphy in patients with ischemic heart disease].

Myocardial washout of the new myocardial perfusion imaging agent, 99mTc-hexakis-2-methoxy isobutyl isonitrile (99mTc-MIBI) was studied in 23 patients with coronary artery disease. These patients were divided into three groups; 8 patients with effort angina pectoris (AP group), 6 with myocardial infarction who had reversible defect (MI-RD (+) group) and 9 with myocardial infarction who had not reversible defect (MI-RD (-) group). Regional radioactivities were determined with postexercise 1- and 3-hour myocardial planar images. In AP group, 99mTc-MIBI washout rate in ischemic area was smaller than in normal area (3.8 +/- 7.5% vs. 8.3 +/- 5.6%, p < 0.05), however, in the remaining two groups, there were no difference in washout between normal and infarct areas. Defect/normal ratios from postexercise 1 hour to 3 hours were slightly increased in AP and MI-RD (+) groups. Our results indicate that 99mTc-MIBI showed slight and incomplete myocardial redistribution in ischemic areas. These data showed to be considered in the interpretation of 99mTc-MIBI myocardial imaging.

Aged↗
PubMed1994

[Simultaneous assessment of exercise-induced abnormalities in myocardial perfusion and regional wall motion by using 99mTc-tetrofosmin].

To clarify the usefulness of the combined assessment of exercise (EX)-induced abnormalities in myocardial perfusion and regional wall motion for detecting coronary artery disease (CAD), we carried out first-pass radionuclide angiography and myocardial perfusion imaging during EX and at rest by 99mTc-tetrofosmin. Twenty-four patients with angiographically proven CAD, 9 (Gp A) with single and 15 (Gp B) with multivessel disease, were studied. The sensitivity for the detection of CAD was 78% of Gp A, 73% of Gp B in planar image and 78%, 87% in SPECT image, respectively. When left ventricular ejection fraction and regional ejection fraction (rEF) were combined with the result of myocardial perfusion, sensitivity increased up to 89% of Gp A, 100% of Gp B. Diagnostic accuracy of LAD, LCX and RCA was 79%, 88% and 83%, respectively. Regional EF in ischemic areas decreased during EX in both Gps, particularly in Gp B. Regional EF in relatively normal perfusion areas did not significantly change in Gp A, but decreased in Gp B. These results suggest that 99mTc-tetrofosmin contributes to the improvement of sensitivity for CAD by combined assessment of EX-induced wall motion and myocardial perfusion abnormalities.

Aged↗
PubMed1993

Synthesis and anthelmintic activity of 13-alkoxymilbemycin derivatives.

The synthesis of milbemycin derivatives having alkyloxy groups at the C-13 position was studied and a series of these analogs of milbemycin A4 and A3 was prepared by the reaction of 13-iodomilbemycin with a variety of alcohols. 13 beta-Phenethyloxy derivatives were found to possess excellent anthelmintic activity. Especially, the activities of derivatives with N-substituted 4-aminophenethyloxy groups were comparable to or superior to ivermectin against Nippostrongylus brasiliensis in rats.

Animals↗