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Biomedical subjects

T Uehara

Publications and source records attributed to T Uehara.

At least 145 records · Page 8Linked to original sources
PubMed1997

Quantification of systolic count increase in technetium-99m-MIBI gated myocardial SPECT.

UNLABELLED: This study was performed to clarify the validity of quantification of myocardial wall thickening by the count increase method using electrocardiography (ECG)-gated SPECT. METHODS: We performed a phantom study to examine the quantification of this method and to clarify the relationship between the changes of relative counts and objective size (such as myocardial wall) under various conditions. In addition, in volunteers, the percent count increase (%CI) was analyzed in left ventricular segments based on circumferential profile curve analysis by ECG-gated SPECT with 99mTc-MIBI (methoxyisobutyl-isonitrile), and it was compared with the regional systolic wall thickness (%Th) assessed by echocardiography during low-dose dobutamine infusion. RESULTS: In our phantom study, the relative count changes were correlated linearly with the object size only within less than 20 mm. Recovery coefficient curves were influenced by acquisition parameters such as type of collimator, diameter of camera rotation, counts and photon scattering. In ECG-gated SPECT, the %CI value was increased gradually at each stage after dobutamine infusion, in relation to the increase of the %Th seen on echocardiography, although there are significant large deviations between these two parameters. CONCLUSIONS: In this study, quantitative analysis based on the %CI in ECG-gated SPECT may underestimate regional wall thickening. These data should be considered in the evaluation of the %CI as an index of myocardial function.

Adult↗
PubMed1997

Intra-individual differences between technetium-99m-HMPAO and technetium-99m-ECD in the normal medial temporal lobe.

UNLABELLED: Regional distributions of 99mTc-hexamethyl propyleneamine oxime (99mTc-HMPAO) and 99mTc-ethyl cysteinate dimer (99mTc-ECD) were compared in the normal brain. METHODS: Six paid, healthy volunteers (mean age 26 yr) had high-resolution neuroperfusion SPECT using both 99mTc-HMPAO and 99mTc-ECD on separate days. RESULTS: Regional distribution of the two tracers differed. Technetium-99m-HMPAO accumulated more in the thalamus, frontal lobe, temporal lobe and cerebellum than 99mTc-ECD, which accumulated more in the occipital and parietal lobes. There was a considerable difference in the accumulation of the two tracers in the medial temporal lobe. The percent accumulations of 99mTc-HMPAO and 99mTc-ECD in the medial temporal lobe compared with the mean global cerebral cortical accumulation were 93.9% +/- 2.4% and 83.1% +/- 4.1% (mean +/- s.d.), respectively. CONCLUSION: The results suggest that 99mTc-HMPAO and 99mTc-ECD require specific and separate criteria for diagnosing temporal lobe pathologies, such as dementia and temporal lobe epilepsy.

Adult↗
PubMed1997

[Occlusive lesions of carotid and intracranial arteries in patients with symptomatic lacunar infarction--evaluation by MR angiography].

The purpose of this study is to elucidate the prevalence and degree of occlusive lesions of carotid and intracranial arteries in patients with symptomatic lacunar infarction. We performed carotid and intracranial MR angiography, and T2-weighted MRI on 65 patients with symptomatic lacunar infarction. Stenosis of more than 25% narrowing of the diameter was found in 12 patients (18.5%) in the extracranial carotid arteries and in 14 patients (21.5%) in the intracranial arteries. Most of the stenotic lesions were mild. Multiple logistic regression analysis showed that age was significant and independent predictor for carotid artery stenosis, and that diabetes mellitus was predictor for intracranial artery stenosis. The incidence of intracranial artery stenosis was statistically higher in patients with asymptomatic lacunar infarctions in subcortical white matter area on T2-weighted MRI than in patients without such lesions. Coexistence of carotid artery stenosis should be suspected in aged patients with symptomatic lacunar infarction, and the possibility of intracranial artery stenosis should be considered in patients with diabetes mellitus or asymptomatic lacunar infarctions in subcortical white matter area.

Adult↗
PubMed1996

Prognosis of hypertrophic cardiomyopathy: assessment by 123I-BMIPP (beta-methyl-p-(123I)iodophenyl pentadecanoic acid) myocardial single photon emission computed tomography.

123I-BMIPP (beta-methyl-iodophenyl pentadecanoic acid) has shown unique properties for potential use in assessing myocardial metabolism. Previous basic and clinical studies demonstrated that the disturbances of myocardial metabolism precede the occurrence of myocardial perfusion abnormalities by using 201Tl in hypertrophic myocardium. The present study was therefore undertaken to determine whether or not 123I-BMIPP myocardial SPECT is useful in predicting the prognosis of hypertrophic cardiomyopathy (HCM) in 65 patients in 6 facilities. There were 33 patients with non-obstructive HCM, 12 with obstructive HCM, 12 with apical HCM and 8 with dilated-phase HCM. Fasted patients at rest received an intravenous injection of 111 MBq of 123I-BMIPP. Twenty to thirty minutes later, myocardial SPECT was carried out. The BMIPP severity score (BMIPP SS) was evaluated semiquantitatively by using representative short axial SPECT images. We followed up the incidence of cardiac events for a mean period of 3.0 +/- 0.6 years. Cardiac events occurred in 13 patients. Of these, 11 developed heart failure and 6 died (4 from heart failure and 2 from sudden death). The BMIPP SS in the dilated-phase HCM was significantly lower than that for the nonsurvivors. The BMIPP SS was particularly high in patients with fatal heart failure. Furthermore, there was a close negative correlation between the BMIPP SS and percent fractional shortening measured by echocardiography (r = -0.49). Finally, the mortality over the three years increased according to the extent of the BMIPP SS. In conclusion, these results indicate that BMIPP SS is useful in evaluating the severity of HCM. We conclude that 123I-BMIPP is a valuable metabolic tracer in predicting the outcome of HCM.

Adult↗
PubMed1996

Paradoxical uptake of F-18 fluorodeoxyglucose by successfully reperfused myocardium during the sub-acute phase in patients with acute myocardial infarction.

The myocardial uptake of F-18 fluorodeoxyglucose (FDG) has been shown to indicate ischemia. To elucidate whether this is applicable to reperfused myocardium in patients with acute myocardial infarction (AMI), Tl-201 SPECT and F-18 FDG PET were performed in 10 patients with successfully recanalized AMI (male myocardial perfusion on the infarct-related area was classified, on the basis of Tl-201 images, into 2 groups (normal and defect) during the sub-acute phase, and into 3 grades (normal, redistribution (RD), and persistent defect) during the chronic phase (1 and 3 months after onset). Regional FDG uptake was calculated as FDG uptake in the region of interest normalized relative to that in a normal area. During the chronic phase, FDG accumulated only in the region of RD, indicating ischemia, but during the sub-acute phase, FDG accumulated mainly in the peri-infarct area. To elucidate whether the reperfused myocardium itself shows signs of accelerated glucose uptake, an experimental study was performed in rats. Glucose uptake in the isolated heart was measured by deoxyglucose and 31P-NMR spectroscopy, and was significantly increased after reperfusion compared with the pre-ischemic level. In conclusion, the enhancement of FDG uptake during the sub-acute phase was observed in successfully reperfused myocardium of patients with acute myocardial infarction. Such augmentation disappeared during the chronic phase. An experimental study in rats indicated that ischemia and reperfusion themselves augment glucose uptake. This mechanism may be responsible for the increase in FDG uptake of reperfused myocardium observed clinically.

Aged↗
PubMed1996

An increased NM23H1 copy number may be a poor prognostic factor independent of LOH on 1p in neuroblastomas.

In a study of 154 neuroblastomas, loss of heterozygosity (LOH) was observed on 1p (13%, 19/143), 11q (19%, 11/59), 14q (15%, 15/97), 17p (5%, 5/105) and 17q (17%, 9/52). We also found an increase in NM23H1 copy number in 14% (13/95) of neuroblastomas. All except one tumour with an increased copy number stained positive with anti-NM23H1 monoclonal antibody. Event-free survival (EFS) was significantly shorter in 19 patients with LOH on 1p than in 128 without (41% vs 77% 4 year EFS, P=0.0093), and in 13 patients with increased NM23H1 copy numbers than in 82 with normal copy numbers of the gene (61% vs 84% 4 year EFS, P=0.0103). LOH on 11q, 14q or 17q did not affect EFS. Most tumours with LOH on 1p, increased NM23H1 copy numbers or MYCN amplification occurred in patients aged 12 months or more, those with advanced stage disease, and those who showed near diploidy or pseudodiploidy. However, LOH on 1p was found in only 1 of the 13 tumours with increased NM23H1 copy numbers, and MYCN amplification of four copies occurred in only one other such tumour. These findings suggest that the increased NM23H1 copy number may be a predictor for poor prognosis, independent of LOH on 1p, and probably also of MYCN amplification.

Alleles↗
PubMed1996

Regulation of Bcl-2 protein expression in human neuroblastoma SH-SY5Y cells: positive and negative effects of protein kinases C and A, respectively.

The regulatory mechanism of Bcl-2 protein expression was investigated in SH-SY5Y cells, the human neuroblastoma cell line that expresses natively Bcl-2 proteins. WHen the cells were treated with 12-O-tetradecanoylphorbol 13-acetate (TPA) or retinoic acid, the level of Bcl-2 protein was increased compared with the control. These effects were inhibited by pretreatment with a protein kinase C (PKC) inhibitor, staurosporine or calphostin C. The level of Bcl-2 protein was also increased by treatment with carbachol, a muscarinic acetylcholine receptor (mAChR) agonist, and the effect were also inhibited by pretreatment with staurosporine or calphostin C. An addition, a carbachol-induced increase in Bcl-2 protein levels and a transient elevation of [Ca2+]i were inhibited by pretreatment with 4-DAMP (4-diphenylacetoxy-N-methylpiperidine), an m3 mAChR antagonist. In contrast, the level of Bcl-2 protein was decreased by treatment with dibutyryl cAMP (diBu-cAMP), forskolin, or cholera toxin, and the effects of diBu-cAMP were inhibited by pretreatment with a protein kinase A (PKA) inhibitor, H-89. From these results, we suggest that the expression of Bcl-2 proteins is regulated by PKC and PKA in positive and negative manners, respectively, in SH-SY5Y cells. Furthermore, the nucleosomal DNA fragmentation induced by serum depletion for 4 h was observed in SH-SY5Y cells when the level of Bcl-2 protein was down-regulated by treatment with 1 mM diBu-cAMP for 3 days, although the DNA fragmentation by serum depletion for 4 h was not observed in nontreatment cells, indicating that Bcl-2 proteins whose expression is regulated by PKC and PKA play important roles in serum depletion-induced apoptosis.

Apoptosis↗
PubMed1996

Reliability of the Japanese version of the Inventory to Diagnose Depression.

The reliability of the Japanese version of the Inventory to Diagnose Depression (IDD) which is a self-report to diagnose major depressive disorders (MDD) of DSM-III-R, was investigated in 30 cases with MDD and 30 control subjects. On test-retest reliability, the agreement of diagnostic performance was substantial (kappa = 0.64, P < 0.001) for 60 subjects, and scores of total and individual items correlated significantly (P < 0.001) between test and retest except for decreased energy, decreased interest, and decreased concentration. The average score of the total IDD severity at test (38.4) was significantly higher than that at retest (28.0; P < 0.01). However, excluding the recovered 10 cases, there was no significant difference seen on the average total score between test and retest (38.8, 30.1, respectively). Internal consistency (Cronbach's alpha = 0.80) and split-half reliability (0.79) were sufficient, and item-total correlations of the IDD were significant (P < 0.01) except for weight gain. The IDD might be useful as a screening tool and for clinical evaluation of subjects in Japan; however, it is necessary to examine the validity of this instrument.

Adolescent↗
PubMed1996

The relationship of DSM-III-R personality disorder to clinical variables in patients with major depression: possible difference between personality disorder clusters.

The relationship of DSM-III-R personality disorder (PD) to demographic and clinical variables was investigated based on 96 consecutive outpatients with major depression. No significant difference in the variables was found between those with and those without PD. Those with PD from each cluster were compared with those without PD in terms of the variables. In these comparisons many relationships of PD to the variables were found, and these relationships were different between the three PD clusters detailed in DSM-III-R. Patients with cluster B PD demonstrated a prominent uniqueness in his/her relationship to the variables. This uniqueness was similar to what had been reported previously with regard to patients with PD. There was no significant difference in the variables between those with cluster C PD and those without PD. Those with cluster A PD may have a negative family history of affective disorders.

Adult↗
PubMed1996

Discriminant validity of the inventory to diagnose depression, lifetime version.

We examined the discriminant validity of the Inventory to Diagnose Depression, lifetime version (IDDL), that is, a self-report instrument designed to diagnose a lifetime history of major depressive disorder. Remitted patients with major depression (MD), remitted patients with anxiety disorders (ADs) and controls completed the IDDL. The IDDL results were then compared in the three contrasts: MD vs. ADs + controls, MD vs. ADs, and MD vs. controls. The agreement between the IDDL and clinical diagnoses was high in each of the three contrasts, and the IDDL total score in the MD group was the highest among the three groups and distinguished from the ADs group or controls. However, the IDDL occasionally diagnosed subjects with a lifetime history of ADs as having a lifetime history of MD.

Adolescent↗
PubMed1996

The test-retest reliability of the inventory to diagnose depression, lifetime version.

The test-retest reliability of the Inventory to Diagnose Depression, Lifetime Version (IDDL) was investigated, based on 57 first-degree relatives of probands with major depression. The subjects were first interviewed using the SCID, and then the IDDL was administered to them twice at a 1-month interval. The chance-corrected agreement in diagnosing a lifetime history of DSM-III-R major depression was high between the 2 trials of the IDDL (kappa = 0.77), and between the SCID and each of the 2 IDDL trials (kappa = 0.75 for the 1 trial, and 0.68 for the 2nd trial). The positiveness on all items except "increased appetite' and "weight gain' was also highly concordant between the 2 trials. These results strongly suggest that time-stable data with sufficient validity for diagnosing a lifetime history of depression can be given by using the IDDL.

Adult↗
PubMed1996

Asymptomatic occlusive lesions of carotid and intracranial arteries in Japanese patients with ischemic heart disease: evaluation by brain magnetic resonance angiography.

BACKGROUND AND PURPOSE: The purpose of this study was to elucidate the prevalence and degree of asymptomatic occlusive lesions in the carotid and intracranial arteries in Japanese patients with ischemic heart disease (IHD). METHODS: We performed carotid and intracranial MR angiography (MRA) on 67 patients (49 men, 18 women; age range, 40 to 78 years; mean age, 60.1 years) who had received selective coronary angiography for the clinical diagnosis of IHD. On the basis of these images, degree of stenosis in the regions of the bilateral carotid artery bifurcation and five regions of the intracranial arteries, ie, bilateral intracranial portions of the internal carotid arteries and the middle cerebral arteries and the basilar artery were estimated. RESULTS: Stenosis of more than 25% narrowing of the diameter of the target arteries was found in 15 patients (22.4%) in the extracranial carotid arteries and in 11 patients (16.4%) in the intracranial arteries. Most of the stenotic lesions were mild. The incidence of extracranial carotid stenosis and the severity of coronary atherosclerosis showed a significant correlation. The mean age of the patients with intracranial arterial lesions was statistically higher than those without intracranial lesions. CONCLUSIONS: Our data suggest that asymptomatic occlusive lesions in the carotid and intracranial arteries are fairly common in Japanese patients with IHD, although the degree of stenosis is relatively mild. Coexistence of carotid atherosclerosis should be suspected in IHD patients with severe coronary atherosclerosis, and the possibility of atherosclerosis in the intracranial arteries should be considered in aged IHD patients.

Adult↗
PubMed1996

Cytologic assessment of metastatic ovarian carcinoma.

Significance of routine cytologic examination in the diagnosis of metastatic ovarian carcinoma was assessed. Twenty-one cases of metastatic carcinoma of the ovary were examined both pathologically and cytologically. Primary sites of the carcinoma were the stomach, breast, large bowel and uterine corpus. Cytology specimens were taken from the portio, endocervix and endometrium of the uterus, ascites and vaginal surgical stump. Malignant cells were detected in the samples from the portio, endocervix and endometrium in two, three and eight cases, respectively. One of the portio and endocervix and two of the endometrial specimens indicated the cases to be from endometrial primary sites. Primary sites of the remaining cases were the stomach and breast. Preoperative and intraoperative cytology of ascites were done in 16 cases and positive results were obtained in 11 cases. Postoperative recurrence was found cytologically in the surgical stump and ascites in two cases. Preoperative routine cytology of the uterus is considered to have diagnostic potential and ascite cytology to be an accurate index of intra-peritoneal spread in the case of metastatic ovarian carcinoma.

Adult↗
PubMed1996

[Evaluation of 123I-iomazenil SPECT in patients with ischemic cerebrovascular disease: comparative study with 123I-IMP SPECT].

Clinical evaluation of 123I-iomazenil, a new imaging agent for central-type benzodiazepine receptors with SPECT, was performed in patients with ischemic cerebrovascular disease. We investigated 15 patients with angiographically-proven severe occlusive lesions (occlusion or > 70% stenosis) in the unilateral carotid system. 123I-iomazenil SPECT images were compared with cerebral blood flow (CBF) images and the cerebral perfusion reserve, which were measured using the "split dose 123I-IMP SPECT method" before and after the intravenous injection of 1 g of acetazolamide. For the detection of ischemic lesions, CBF images were superior to 123I-iomazenil images based on visual analysis. Regarding the count ratio of the affected MCA territory to the non-affected (L/N), 123I-IMP was lower than 123I-iomazenil in most of the cases. In five patients showing "crossed cerebellar diaschisis" by 123I-IMP, asymmetry of the cerebellar accumulation was observed in only one patient with 123I-iomazenil, which was less prominent than with 123I-IMP. There was no significant correlation between the L/N ratio with 123I-iomazenil and the cerebral perfusion reserve in the affected MCA territory. However, in some cases showing a decreased L/N ratio (< 90%) with 123I-iomazenil, a decreased CBF with normal perfusion reserve and cerebral hemi-atrophy were observed with 123I-IMP and MRI, which suggested the influence of neuronal loss due to chronic ischemia. These results indicate that 123I-iomazenil SPECT, which provides new information regarding neuronal loss due to ischemic damage to the brain, is useful for the evaluation of ischemic cerebrovascular disease.

Adult↗
PubMed1996

Pathological aspects of normal-sized ovarian carcinoma.

Twenty cases of ovarian carcinoma with normal-sized ovaries were examined histologically. Fifteen of them had metastatic disease of the peritoneal cavity and three of the remaining showed uterine involvement. Only in one case was the tumor confined to the ovary, but this patient had experienced systemic chemotherapy before surgery. The remaining case had metastasis of the stomach. Thus, "normal-sized" ovarian carcinoma has a great tendency to spread externally. Histology of the carcinoma was that of common epithelial carcinoma of the ovary with variable degrees of differentiation except for three cases of apparent ovarian metastasis. No cases of definite mesothelioma with ovarian involvement were encountered. A search for determinants of the peritoneal spread was performed using immunohistochemistry for p53 and bcl-2 proteins. However, no differences were found in the antigen expression between the group with and without peritoneal metastasis.

Adult↗
PubMed1996

[Usefulness of 123I-BMIPP scanning for distinction of ischemic from nonischemic dilated cardiomyopathy].

To determine if imaging of blood flow (using 201Tl) and fatty acid (using 123-I-BMIPP) with SPECT can distinguish cardiomyopathy of coronary artery disease from nonischemic dilated cardiomyopathy, 24 patients with severe left ventricular dysfunction were evaluated. The origin of left ventricular dysfunction had been previously determined by coronary angiography to be ischemic (9 patients) or nonischemic (15 patients). Images were visually analyzed by three observers on a graded scale (score 0; normal, 1; mild uptake reduction, 2; severe uptake reduction, and 3; defect) in 20 left ventricular segments revealed higher defect score in ICM compared with NCM for 123I-BMIPP (35.5 +/- 14.4 versus 14.1 +/- 9.3, p <0.0005) and 201Tl (27.6 +/- 14.6 versus 12.1 +/- 7.4, p <0.005). The defect score/segment ratio also revealed higher value in ICM compared with NCM for 123I-BMIPP (2.25 +/- 0.52 versus 1.36 +/- 0.36, p <0.0001) and 201Tl (1.92 +/- 0.51 versus 1.24 +/- 0.42, p <0.005). Myocardium of ICM is more severely damaged than that of NCM. Thus, noninvasive SPECT imaging with 123I-BMIPP is helpful in distinguishing patients with severe left ventricular dysfunction secondary to coronary artery disease from those with nonischemic cardiomyopathy.

Adult↗
PubMed1996

Abnormal iodine-123-MIBG images in healthy volunteers.

We have encountered two healthy volunteers with significant reductions of myocardial [123I]MIBG (metaiodobenzylguanidine) uptake and rapid clearance. In one of these subjects (a 31-yr-old man), we performed additional examinations to clarify the mechanism of the abnormal myocardial MIBG uptake. There was no abnormality on orthostatic test, maximal exercise test (bicycle ergometer) or in plasma norepinephrine concentration. Nevertheless, power spectral analysis (PSA) of heart rate variability revealed that the percent low frequency component (%LF), an index of sympathetic nerve activity, was increased. Furthermore, [123I]MIBG scintigraphy after oral administration of an alpha 2 agonist (guanabenz acetate; 4 mg) demonstrated that myocardial uptake and clearance of MIBG returned to normal, as did the %LF. These results suggest that reduced uptake and rapid clearance of myocardial MIBG in this subject was strongly related to the increased release of norepinephrine from sympathetic nerve terminals due to augmented sympathetic activity. This subject illustrated that unsuspected, subclinical variants of normal or abnormal sympathetic functions may pose a diagnostic pitfall in interpretating myocardial MIBG images.

3-Iodobenzylguanidine↗