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Several LGSO samples with different Ce doping were studied in comparison to GSO crystal. The light output, non-proportionality of the light response, energy resolution and intrinsic resolution were measured and compared to the intensity of the afterglow recorded in the second range of time. A high light output of 17000 [+ or -] 1700 ph/MeV and a good energy resolution of 6.54 [+ or -] 0.2% for 662 keV gamma rays from a [sup.137]Cs source were obtained for the best sample, doped with 1 mol% of Ce. The energy resolution and, in particularly the intrinsic resolution varied with the concentration of Ce in the tested crystals and were not correlated with their common non-proportionality characteristics. In contrast, the observed correlation of the intrinsic energy resolution of the LGSO crystals and the intensity of their afterglow indicates that the energy resolution of scintillation detectors may be affected by a strong afterglow of the crystals. Thus, it suggests to the manufacturers to make more efforts to reduce afterglow in the crystals. Index Terms--Afterglow, Ce doped scintillators, energy resolution, non-proportionality of the light yield.

We developed [Lu.sub.0.4][Gd.sub.1.6]Si[O.sub.5] (LGSO) crystal as a new scintillator for medical imaging applications. The size of the LGSO ingot obtained for this investigation was approximately 60 mm in diameter and 170 mm in length. The as-grown crystal was yellow in color. To eliminate the tint, the crystal was annealed in pure [N.sub.2] atmosphere after the growth. As a result, the LGSO became colorless with uniform and large light output which is about 2.0 times that of GSO. Index Terms--Annealing, LGSO, scintillation properties.

The emission spectra for X-ray and UV excitation, decay curve for emission above 460 nm under [gamma]-ray excitation, and energy spectrum by using avalanche photodiode (APD) for excitation with [sup.137] Cs [gamma]-rays have been measured for [Lu.sub.0.4] [Gd.sub.1.6] Si[O.sub.5] having 2.0 mol% Ce. The emission spectrum under X-ray excitation showed two peaks around 430 and 495 nm. The excitation-emission spectrum under UV excitation also had two peaks at 425 and 510 nm for excitation wavelength of 285 and 385 nm, respectively. There was no significant difference in decay constants of emission between the longer and shorter wavelength components. Energy resolution by using an APD was 8.0% for [sup.137] Cs [gamma]-ray excitation. Index Terms--Emission wavelength, radiation detector, scintillator.

Cerium doped [Gd.sub.2] Si[O.sub.5] (GSO:Ce) single crystal is used as a scintillator for Positron Emission Tomography (PET). GSO:Ce has a good balance of every scintillation properties, but the only disadvantage is the decreasing light output by coloring caused by a small amount of [Ce.sup.4+] in the crystal especially at higher concentration of Ce. In order to improve the scintillation performance, we have tried to grow co-doped GSO:Ce single crystal using conventional starting materials with additional impurities, and evaluate the scintillation performance. Zr doping is found to be effective in preventing coloring and in improving light output. Around 200 ppm Zr doped GSO:Ce have shown maximum light output which is about 20% larger than that of conventional GSO:Ce. This improvement can be explained by the fact that the amount of [Ce.sup.4+] in the crystal might be changed to [Ce.sup.3+] due to charge compensation caused by dopant [Zr.sup.4+] in a [Gd.sup.3+] site thereby decreasing the light absorption in the crystal. Index Terms--Crystal growth, gadolinium compounds, positron emission tomography, scintillation detectors.

We propose and test a one-dimensional (l-D) sharing block detector using dual photo-multiplier tubes (PMT). The detector consists of scintillator blocks and dual PMTs. The dual PMTs are optically coupled on the scintillator blocks and overlap in one dimensional. With this configuration, the scintillator size of the block detector can be reduced to half that of a conventional block detector in one direction, and isotropic spatial resolution can be obtained in transaxial and axial directions using commercially available dual PMTs. First, we measure the position and energy response for minimum configuration; one GSO block and two dual PMTs. The size of a single GSO is 2.9 mm x 2.9 mm x 20 mm. The scintillators are arranged in an 8 x 8 matrix with multi-layer optical film inserted partly between scintillators to obtain the resolved position response. We obtain good position and energy responses with this configuration. Next, we fabricate a 1-D sharing block detector with five GSO blocks and six dual PMTs. With this configuration, we also obtain reasonable position and energy responses. These results indicate that the proposed 1-D sharing block detector is a promising solution for developing high-resolution and low cost PET systems. Index Terms--Dual photomultiplier tube, positron emission tomography, sharing block detector.

We have developed [Lu.sub.0.4][Gd.sub.1.6]Si[O.sub.5]:Ce (LGSO) crystals as a new scintillator for medical applications. Scintillation properties of LGSO crystal of various Ce concentrations and their dependence on annealing effect were studied. Its absorption coefficient at 511 KeV gamma rays is 0.70 [cm.sup.-1]. We observed that the light output and decay time are dependent on the Ce concentration in the crystal. Decay constant decreases with increasing Ce. Annealing of the colored crystal having 2.0 mol% Ce makes it colorless with better scintillation properties: large light output (40% of NaI:TI), good energy resolution (8.3% for 4 x 6 x 20 [mm.sup.3] crystal) and fast decay constant (65 ns of primary component and 180 ns of secondary component).

Cerium-doped [Gd.sub.2]Si[O.sub.5] (GSO) scintillator has good scintillation properties such as high density, intense light output, short decay time, excellent temperature stability, and extremely good energy resolution. In order to apply GSO single-crystal scintillators to a commercial PET, we have tried to increase the size of the GSO single-crystal for increasing production capacity and reducing production cost. To grow the large GSO single-crystal, we have optimized growth conditions and atmosphere in the furnace. We have developed growing technology of large GSO single crystals with a diameter of 100 ram. Thousands of specimens with a size of 4 x 6 x 20 [mm.sup.3] were sampled from each ingot. Uniformity of the light output, energy resolution and decay time in the crystal has been demonstrated for PET application. Index Terms--Crystal growth, gadolinium compounds, positron emission tomography (PET), scintillation detectors.

Aim To examine the contribution of the FUT2 gene and ABO blood type to the development of Type 1 diabetes in Japanese children. Methods We analysed FUT2 variants and ABO genotypes in a total of 531 Japanese children diagnosed with Type 1 diabetes and 448 control subjects. The possible association of FUT2 variants and ABO genotypes with the onset of Type 1 diabetes was statistically examined. Results The se2 genotype (c.385A>T) of the FUT2 gene was found to confer susceptibility to Type 1A diabetes in a recessive effects model [odds ratio for se2/se2, 1.68 (95% CI 1.20-2.35); corrected P value = 0.0075]. Conclusions The FUT2 gene contributed to the development of Type 1 diabetes in the present cohort of Japanese children. [ABSTRACT FROM AUTHOR]

Aims The aim of this study was to clarify the significance of previously reported susceptibility variants in the development of autoimmune Type 1 diabetes in non-white children. Tested variants included rs2290400, which has been linked to Type 1 diabetes only in one study on white people. Haplotypes at 17q12-q21 encompassing rs2290400 are known to determine the susceptibility of early-onset asthma by affecting the expression of flanking genes. Methods We genotyped 63 variants in 428 Japanese people with childhood-onset autoimmune Type 1 diabetes and 457 individuals without diabetes. Possible association between variants and age at diabetes onset was examined using age-specific quantitative trait locus analysis and ordered-subset regression analysis. Results Ten variants, including rs2290400 in GSDMB, were more frequent among the people with Type 1 diabetes than those without diabetes. Of these, rs689 in INS and rs231775 in CTLA4 yielded particularly high odds ratios of 5.58 (corrected P value 0.001; 95% CI 2.15-14.47) and 1.64 (corrected P value 5.3 × 10-5; 95% CI 1.34-2.01), respectively. Age-specific effects on diabetes susceptibility were suggested for rs2290400; heterozygosity of the risk alleles was associated with relatively early onset of diabetes, and the allele was linked to the phenotype exclusively in the subgroup of age at onset ≤ 5.0 years. Conclusions The results indicate that rs2290400 in GSDMB and polymorphisms in INS and CTLA4 are associated with the risk of Type 1 diabetes in Japanese children. Importantly, cis-regulatory haplotypes at 17q12-q21 encompassing rs2290400 probably determine the risk of autoimmune Type 1 diabetes predominantly in early childhood. [ABSTRACT FROM AUTHOR]

Aims: Many patients with idiopathic dilated cardiomyopathy (DCM) have been diagnosed on the basis of the exclusion of significant coronary stenosis and the presence of left ventricular (LV) dysfunction. In the present study, we investigated the possibility that coronary multispasm is one of the mechanisms leading to diffuse idiopathic DCM-like LV dysfunction. Methods and Results: Forty-two patients with severely depressed LV function but without significant coronary stenosis were enrolled (baseline LV ejection fraction, 33 ± 11%). An acetylcholine (ACh) provocation test was performed at the time of coronary angiography. In patients with a positive ACh provocation test (n = 20), coronary angiography revealed multivessel diffuse coronary spasm with marked electrocardiogram changes. In patients with a negative ACh provocation test (n = 22), significant findings compatible with idiopathic DCM were more frequently observed on magnetic resonance imaging (MRI) or in LV biopsies compared with the ACh-positive group (MRI, 73% vs. 12%; and LV biopsy, 71% vs. 0%, respectively; P < 0.01). In the ACh-positive group, LV function significantly improved after the administration of calcium channel blockers (LV ejection fraction, 34 ± 12% vs. 54 ± 10%; and brain natriuretic peptide, 803 ± 482 pg/mL vs. 69 ± 84 pg/mL, at baseline and 1 year, respectively; P < 0.01). Conclusions: Our results raise the possibility that patients with LV dysfunction due to repeated coronary multispasm are being diagnosed as idiopathic DCM, and that calcium channel blockers may prove to be a promising therapeutic strategy in those patients. [ABSTRACT FROM AUTHOR]