[en] Exercise echocardiography and exercise thallium-201 (²⁰¹Tl) single photon emission computed tomography (SPECT) were performed in 152 patients with suspected coronary artery disease, including 61 patients with old myocardial infarction. All patients underwent coronary arteriography, and coronary artery disease was defined as ≥75% diameter stenosis. Digital two-dimensional echocardiography was performed before and after the treadmill exercise test, and wall motion abnormality was evaluated using quad-screen. Sensitivity and specificity for the diagnosis of coronary artery disease were similar for the 2 exercise tests (77% and 80% for echocardiography and 75%, and 83% for SPECT, respectively). Diagnoses for one-vessel disease, 2-vessel disease and 3-vessel disease were similar for echocardiography (79%, 72% and 77%, respectively) and SPECT (74%, 75% and 77%, respectively). Sensitivity for the diagnosis of ischemia at the area remote from infarct area was low for both exercise echocardiography and exercise SPECT (45% and 48%, respectively). Exercise echocardiography has comparable diagnostic value to SPECT for the detection of coronary artery disease. However, both exercise tests have limitations for the diagnosis of ischemia at the area remote from infarct area. (author)

[en] HTLV-I carriers or patients with HTLV-I associated myelopathy (HAM) are prone to immune-mediated inflammatory disorders. We present a 44-year-old female with HAM who developed Graves' disease. She developed severe Graves' ophthalmopathy shortly after ¹³¹I therapy, concurrently with a remarkable increase in TSH-receptor antibody titer. Ophthalmopathy was aggravated in spite of prednisolone therapy and euthyroidism being maintained by thyroxine replacement. Uveitis also developed after ¹³¹I therapy and iridocyclitis finally required trabeculotomy. This case suggests that HAM patients may have a higher risk of immune-mediated Graves' ophthalmopathy after ¹³¹I therapy.(author)

[en] Experimental and clinical studies suggest that X-irradiation to the coronary artery may enhance vasoconstrictive response. This study aimed to clarify the effect of X-irradiation on the vasomotor response of porcine coronary artery. X-ray (15 Gy) was selectively irradiated to the left anterior descending coronary artery (LAD) in 14 Goettingen miniature pigs. The coronary vasomotor responses to serotonin at the irradiated site (LAD) and the control site (the left circumflex artery; LCX) were assessed by quantitative arteriography before and 1 h and 1, 2, and 4 weeks after X-irradiation. At 2 weeks, endothelium-dependent vasodilation in response to substance P was also evaluated arteriographically in vivo. At 2 weeks, isometric tension studies were performed to evaluate the constrictive responses of medial muscle strips and endothelium-dependent relaxation. Coronary vasoconstriction in response to serotonin was enhanced 1 week after, and further augmentation was noted 2 and 4 weeks after x-irradiation. Endothelium-dependent vasodilation in response to substance P in vivo was preserved 2 weeks after X-irradiation. Coronary arteriography showed no organic stenosis at the irradiated site. In vitro studies demonstrated that medial muscle strips of the irradiated site showed hypercontraction in response to serotonin and that endothelium-dependent relaxation in response to serotonin and substance P was preserved at the irradiated site. A histological study revealed no appreciable changes of the endothelial cells or intimal thickening. These results suggest that coronary vasoconstriction in response to serotonin was enhanced 1 week after X-irradiation, and that this hyperconstriction was caused by the increased constrictive response of medial smooth muscle, but not by impaired endothelium-dependent relaxation or by a geometric effect due to intimal thickening. (author)

[en] Arrhythmogenic right ventricular dysplasia (ARVD) is a recently identified clinical entity and its diagnosis rests on documentation of ventricular tachycardia (VT) of right ventricular origin and morphologic changes of the right ventricle. However, the diagnosis of ARVD is difficult noninvasively and often requires angiography. The usefulness of equilibrium radionuclide ventriculography as a noninvasive method for the diagnosis of ARVD has not been fully evaluated. We performed equilibrium radionuclide ventriculography in 7 patients with ARVD, 10 normal subjects and 9 patients with dilated cardiomyopathy (DCM). The right ventricular ejection fraction (EF) in patients with ARVD (25 ± 8 %, mean ± SD) was lower (p < 0.001) than that in normal subjects (56 ± 7 %) but was not significantly different from that in patients with DCM (32 ± 10 %). The left ventricular EF in patients with ARVD (57 ± 12 %) was lower (p < 0.05) than that in normal subjects (70 ± 7 %), but higher (p < 0.001) than that in patients with DCM (27 ± 7 %). These findings suggest that ARVD is a specific from of DCM which predominantly affects the right ventricle and that equilibrium radionuclide ventriculography may be a useful noninvasive method for the diagnosis of this disorder. In addition, we present a family in which 3 of 6 siblings were affected by ARVD, suggesting that some genetic factors may be involved in the etiology of this disorder. (author)

[en] The X-band linear accelerator, which can generate such a short pulse as 100fs, is under design at the Nuclear Engineering Research Laboratory, the University of Tokyo. The design study of the X-band linac is carried out by using PARMELA and SUPERFISH. Then it is found that 600 ps (tail-to-tail) emission from a thermionic gun can be bunched to about 1 ps (FWHM) at the end of the 2nd accelerating tube and 80% of the initial charge is transmitted. (author)

[en] The present study was to assess coronary blood flow associated with extensive intimal dissection early after percutaneous transcatheter angioplasty (PTCA) by examining the relationship between stress SPECT findings and coronary flow reserve (CFR). Before performing PTCA, 45 patients with angina pectoris were divided into two groups: (I) patients having positive stress-induced perfusion defect (SPD) and 51% or more coronary stenosis and (II) those having negative SPD and less than 51% coronary stenosis. A mean CFR was 1.54±0.44 in Group I, compared to 4.81±0.26 in Group II. SPECT had a sensitivity of 93% for less than 2.0 of CFR and a specificity of 98% for 2.0 or more. After performing PTCA, the patients were divided into two groups: those having coronary angiographically proven extensive intimal dissection (D) and those having not definitive dissection (N). There was no significant difference in severity of coronary stenosis between the groups. CFR tended to be lower in Group D than Group N (3.22±0.51 vs 4.32±0.44), but this was not statistically significant. Positive SPD was seen in 2 patients in Group D and one patient in Group N. It was concluded that there was good correlation between CFR and the ability of SPECT to detect ischemia and that extensive intimal dissection may be less frequently associated with ischemia. (N.K.)

[en] Femtosecond quantum phenomena research project is proposed at Nuclear Engineering Research Laboratory, University of Tokyo. The research facility consists of an X-band (11.424 GHz) femtosecond electron linac, a femtosecond wavelength tunable laser, two S-band (2.856 GHz) picosecond electron linacs and measuring equipments. Especially, we aim to generate a 100fs (FWHM) electron single bunch with more than 1nC at the X-band linac. Ultrafast processes in radiation physics, chemistry, material science and microscopic electromagnetic phenomena are going to be analyzed there. The specification of the facility is presented. (author)

[en] Proliferation of vascular smooth muscle cells (VSMCs) is induced by various mitogens through activation of extracellular signal-regulated protein kinase (ERK) pathway. We recently reported that peroxisome proliferator-activated receptor (PPAR)γ activators such as 15-deoxy-Δ^12,14-prostaglandin J2 (15-d-PGJ2) and thiazolidinediones (TZDs) activated MEK/ERK pathway through phosphatidylinositol 3-kinase (PI3-K) and induced proliferation of VSMCs. However, the precise mechanisms of PPARγ activators-induced activation of PI3-K/ERK pathway have not been determined. We examined whether transactivation of growth factor receptor is involved in this process. Stimulation of VSMCs with 15-d-PGJ2 or TZDs for 15 min induced phosphorylation of ERK1/2 and Akt. 15-d-PGJ2- or TZDs-induced phosphorylation of ERK1/2 and Akt was inhibited by AG1478, an inhibitor of epidermal growth factor receptor (EGF-R) as well as AG1295, an inhibitor of platelet derived growth factor receptor (PDGF-R). 15-d-PGJ2-induced phosphorylation of both EGF-R and PDGF-R. GM6001, a matrix metalloproteinase inhibitor, and PP2, a Src family protein kinase inhibitor, suppressed 15-d-PGJ2- and TZDs-induced phosphorylation of EGF-R and PDGFβ-R as well as activation of ERK1/2 and Akt. PDGFβ-R was co-immunoprecipitated with EGF-R, regardless of the presence or absence of 15-d-PGJ2. These data suggest that 15-d-PGJ2 and TZDs activate PI3-K/ERK pathway through Src family kinase- and matrix metalloproteinase-dependent transactivation of EGF-R and PDGF-R. Both receptors seemed to associate constitutively. This novel signaling mechanisms may contribute to diverse biological functions of PPARγ activators

[en] Recently, we reported the presence of distinct cell clusters named acinar-like cell clusters touching Langerhans islets with thin interstitial surrounding (ATLANTIS) in human pancreas. A morphological study in humans demonstrated that ATLANTIS and islet cell clusters are found together in the microenvironment enclosed by a common basement membrane, and ATLANTIS releases vesicles containing Regenerating gene protein (REG Iα) to islet cell clusters. We examined 1) the presence or absence of ATLANTIS in homozygous Reg I (mouse homologue of human REG Iα) deficient (Reg I^−/-) and wild-type mice, and 2) the possible role of ATLANTIS in the regeneration of beta cell clusters after encephalomyocarditis (EMC) virus (D-variant) infection in Reg I^−/- and wild-type mice. ATLANTIS was found in both wild-type and Reg I^−/- mice. In both groups, mean blood glucose increased transiently to greater than 14.0 mmol/L at 5 days after EMC virus infection and recovered to baseline at 12 days. At 12 days after EMC virus infection, lower BrdU labeling indices were observed in islet beta cells of Reg I^−/- mice compared to wild-type mice. Beta cell volume 12 days after EMC virus infection in Reg I^−/- mice did not differ from that of wild-type mice. These results suggest that Reg I, which is released from ATLANTIS to islet beta cell clusters, has a crucial role in beta cell regeneration in EMC virus-induced diabetes. The presence of mechanism(s) other than that mediated by Reg I in beta cell restoration after destruction by EMC virus was also suggested.