Development of reverse genetics for Ibaraki virus to produce viable VP6-tagged IBAV.

Ibaraki virus (IBAV) is a member of the epizootic hemorrhagic disease virus (EHDV) serogroup, which belongs to the Orbivirus genus of the Reoviridae family. Although EHDV, including IBAV, represents an ongoing threat to livestock in the world, molecular mechanisms of EHDV replication and pathogenesis have been unclear. The reverse genetics (RG) system is one of the strong tools to understand molecular mechanisms of virus replication. Here, we developed a RG system for IBAV to identify the nonessential region of a minor structural protein, VP6, by generating VP6-truncated IBAV. Moreover, several tags were inserted into the truncated region to produce VP6-tagged IBAV. We demonstrated that all VP6-tagged IBAV could replicate in BHK cells in the absence of any helper VP6 protein. Further, tagged-VP6 proteins were first assembled into puncta in cells infected with VP6-tagged IBAV. Our data suggests that, in order to initiate primary replication, IBAV VP6 is likely to accumulate in some parts of infected cells to assemble efficiently into the primary replication complex (subcore)

Relationship between the severity of obstructive sleep apnea and impaired glucose metabolism in patients with obstructive sleep apnea

SummaryBackgroundThe relationship between the severity of obstructive sleep apnea (OSA) and impaired glucose metabolism (IGM) has not yet been fully elucidated in patients with OSA. Accordingly, we sought to clarify this relationship in Japanese patients with OSA.MethodsThe study population consisted of 129 Japanese patients with OSA (apnea-hypopnea index [AHI] ≥5). A 75-g oral glucose tolerance test was performed in all patients who had not been diagnosed as diabetes mellitus (DM). IGM was defined as either diabetes mellitus (DM) or impaired glucose tolerance (IGT).ResultsIGM was observed in 78 (60.5%) patients: DM in 39 (30.2%) and IGT in 39 (30.2%). The frequency of IGM was significantly different among patients with AHI ≥30, those with 15 ≤ AHI <30, and those with AHI <15 (72.1%; 53.7%; 35.0%; respectively, p=0.001). Univariate logistic regression analyses showed male sex, the BMI, the AHI, and the lowest SpO2 to be significantly associated with IGM. A stepwise multivariate logistic regression analysis showed a male sex and the AHI to be independently associated with IGM.ConclusionIGM was observed in 60.5% of Japanese patients with OSA (AHI ≥5), and the prevalence of IGM increased according to the severity of OSA. Furthermore, the AHI was independently associated with IGM, thus suggesting that OSA may contribute to the development of IGM

Analysis of Surface Crack Propagation Considering the Effect of Micro-separations

In the TMCP steels rolled at the finishing temperature in austenite-ferrite region by the Non-AcC type TMCP method, it becames clear that the fatigue fracture surface had a lot of micro-separations, and fatigue crack propagation was prevented by micro-separations in the case of propagation in the direction of plate thickness. In this study, the authors investigated on the behavior of surface crack propagation using three TMCP steels with different SImax, and proposed the method of crack propagation analysis considering the effect of micro-separations. The results may be summarized as follows: (1) As SImax increase, propagation pattern of surface crack become shallow. (2) The macroscopic fatigue crack propagation can be analyzed with the assumption that the fatigue crack propagation in the direction of plate thickness passes through between estimated microseparations. (3) This estimation method shows the good agreement with the experimental change of aspect ratio for surface crack

Accuracy of ventricular volume and ejection fraction measured by gated myocardial SPECT: Comparison of 4 software programs

金沢大学大学院医学系研究科Gated myocardial perfusion SPECT has been used to calculate ejection fraction (EF) and end-diastolic volume (EDV) and has correlated well with conventional methods. However, the comparative accuracy of and correlations across various types of gated SPECT software are not well understood. Methods: Mathematic phantoms of cylindric-hemispheric hybrid models, ranging in volume from 34 to 266 mL, were generated. The clinical cases consisted of 30 patients who participated in a radionuclide angiography and gated blood-pool (GBP) study in addition to undergoing 99mTc-sestamibi gated SPECT. Four kinds of software, Quantitative Gated SPECT (QGS), the Emory Cardiac Toolbox (ECT), 4D-MSPECT, and Perfusion and Functional Analysis for Gated SPECT (pFAST) were used to compute EF and EDV, and the results were analyzed by multiple comparisons tests. Patients were classified into 4 groups (i.e., no defect, small defect, large defect, and small heart) so that factors affecting variation could be analyzed. Results: In mathematic models ≥74 mL, volume error was within ±15%, whereas for a small volume (34 mL), QGS and 4D-MSPECT underestimated the volume and pFAST overestimated it. The respective intra- and interobserver reproducibility of the results was good for QGS (r=0.99 and 1.00), ECT (r=0.98 and 0.98), and 4D-MSPECT (r=0.98 and 0.98) and fair for pFAST (r=0.88 and 0.85). The correlation coefficient for EF between gated SPECT and the GBP study was 0.82, 0.78, 0.69, and 0.84 for QGS, ECT, 4D-MSPECT, and pFAST, respectively. The correlation coefficient for EDV between gated SPECT and the GBP study was 0.88, 0.89, 0.85, and 0.90, respectively. Although good correlation was observed among the 4 software packages, QGS, ECT, and 4D-MSPECT overestimated EF in patients with small hearts, and pFAST overestimated the true volume in patients with large perfusion defects. Correlation coefficients among the 4 kinds of software were 0.80-0.95 for EF and 0.89-0.98 for EDV. Conclusion: All 4 software programs showed good correlation between EF or EDV and the GBP study. Good correlation was observed also between each pair of quantification methods. However, because each method has unique characteristics that depend on its specific algorithm and thus behaves differently in the various patient subgroups, the methods should not be used interchangeably

Predicting the outcome of distraction osteogenesis by 3-phase bone scintigraphy

金沢大学大学院医学系研究科Distraction osteogenesis is an effective method for lengthening long bones and filling bone defects that result from bone resection. Insufficiency of bone consolidation in the distraction segment is problematic. In this study, we examined whether 3-phase bone scintigraphy can predict the outcome of distraction osteogenesis. We also investigated the effects of chemotherapy and surgical treatment on distraction osteogenesis. Methods: We performed 3-phase bone scintigraphy on 60 patients (9 high-grade malignant bone tumors as group A, 11 low-grade malignant or benign tumors as group B, 40 nontumoral conditions as group C) with distraction osteogenesis at the lengthening phase of the long bones. By setting the region of interest on the distraction segment and contralateral normal area, we calculated the perfusion index (PI), the uptake ratio of the blood-pool image (BPR), and the uptake ratio of the delayed image (DR). Patients were classified into poor and good consolidation groups from the radiographic findings of the distraction segment. Results: Good to fair correlations were obtained between the PI and BPR, the PI and DR, and the BPR and DR (r = 0.65, 0.45, and 0.57, respectively). The PI and BPR indicated no significant differences among group A-C (1.7 ± 0.6, 2.1 ± 0.7, and 1.8 ± 0.8 in PI, respectively; 1.8 ± 1.1, 1.9 ± 0.5, and 2.0 ± 0.7, in BPR, respectively). The DR of group A (2.4 ± 1.2) was significantly lower than that of group B (6.3 ± 1.8; P = 0.001) and group C (5.9 ± 2.8; P < 0.001). Eleven patients were classified in the poor consolidation group. The other 49 patients showed good consolidation. The poor consolidation group showed lower values in all indices obtained by 3-phase bone scintigraphy than the good consolidation group. The optimal cutoff levels, sensitivity, specificity, and accuracy of each index for detection of patients with poor consolidation were as follows: 1.1, 36%, 90%, and 80% in the PI, respectively; 1.2, 55%, 94%, and 87% in the BPR, respectively; and 2.2, 82%, 96%, and 93% in the DR, respectively. Conclusion: Three-phase bone scintigraphy is a promising method for the assessment of distraction osteogenesis. The delayed image of 3-phase bone scintigraphy, especially, is an excellent modality for predicting the outcome of distraction osteogenesis

Quantification of myocardial perfusion SPECT using freeware package (cardioBull)

Objective: We have developed freeware package for automatically quantifying myocardial perfusion and 123I-labeled radiopharmaceutical single-photon emission computed tomography (SPECT), which is called "cardioBull". We aim to evaluate diagnostic performance of the detection of coronary artery disease (CAD) on the developed software in comparison with commercially available software package [Quantitative Perfusion SPECT (QPS)]. Methods: Stress-rest 99mTc-sestamibi myocardial perfusion SPECT was performed in 36 patients with CAD and 35 control patients. A ≥75% stenosis in the coronary artery was identified by coronary angiography in the CAD group. Segmental perfusion defect score was automatically calculated by both cardioBull and QPS software. Summed stress score (SSS) was obtained to detect CAD by the receiver operator characteristic (ROC) analysis. Areas under the ROC curves (AUC) were calculated in patient-based and coronary-based analyses. Results: Mean SSSs showed no significant difference between cardioBull and QPS (6.0 ± 7.1 vs. 5.6 ± 7.0). The AUC for cardioBull was equivalent to that for QPS (0.91 ± 0.04 vs. 0.87 ± 0.04, p = n.s.). Sensitivity, specificity, and accuracy for cardioBull were 89, 74, and 82%, respectively. For the regional detection of CAD, the AUC showed largest value in left anterior descending coronary artery (LAD) territory (0.86 ± 0.06 for cardioBull, 0.87 ± 0.06 for QPS, p = n.s.). Sensitivity, specificity and accuracy of cardioBull were 70, 88, and 83% for the LAD; 91, 62, and 66% for the left circumflex coronary artery (LCx); and 78, 69, and 70% for the right coronary artery (RCA), respectively. Conclusions: The AUC, sensitivity, specificity and accuracy for the detection of CAD showed high diagnostic performance on the developed software. In addition, the developed software provided comparable diagnostic performance to the commercially available software package. © 2011 The Japanese Society of Nuclear Medicine

Diastolic dysfunction in patients with systemic sclerosis detected by gated myocardial perfusion SPECT: An early sign of cardiac involvement

金沢大学大学院Diagnosis of cardiac involvement is important for the management of patients with systemic sclerosis (SSc). This study was undertaken to determine the significance of gated myocardial perfusion SPECT in patients with SSc and whether diastolic function measured by gated SPECT is an early sign of cardiac complications. Methods: Thirty-four patients with SSc and 16 control patients were studied using exercise nongated and resting gated myocardial perfusion SPECT. The SSc was classified by the modified Rodnan total skin score (TSS) into high-TSS (score ≥ 10; n = 18) and low-TSS (score < 10; n = 16) groups. Gated SPECT was performed using 99mTc-methoxyisobutyl-isonitrile with 16 frames per cardiac cycle and quantitatively analyzed by QGS software and Fourier filtering of the volume curve. The parameters of ejection fraction (EF), peak filling rate (PFR), one-third mean filling rate, and time to PFR (TPFR) were calculated. Results: A slight perfusion abnormality was observed in four and five patients in the low-TSS and high-TSS groups, respectively (not statistically significant). A decreased resting EF less than 55% was found in no and two patients in the low-TSS and high-TSS groups, respectively. TPFR was 166 ± 22, 168 ± 38, and 216 ± 82 ms (P = 0.05, high-TSS group versus low-TSS group; P = 0.04, control group versus high-TSS group) and TPFR/R-R interval was 0.18 ± 0.02, 0.19 ± 0.04, and 0.26 ± 0.09 (P = 0.01, high-TSS group versus low-TSS group; P = 0.005, control group versus high-TSS group) for the control, low-TSS, and high-TSS groups, respectively. Conclusion: Diastolic function can be evaluated by gated myocardial perfusion SPECT. Significant diastolic abnormalities were shown even in patients with normal perfusion and systolic function and were related to the severity of SSc

The validity of multi-center common normal database for identifying myocardial ischemia: Japanese Society of Nuclear Medicine Working Group Database

金沢大学医薬保健研究域医学系Purpose The Japanese Society of Nuclear Medicine (JSNM) working group has created a myocardial perfusion imaging database applicable to standard acquisition protocol. The aim of this study is to validate the diagnostic accuracy of the common normal database compared with the expert interpretation of each institute. Methods Five institutions participated in this study and used different acquisition settings which included 360°/ 180° rotation, camera configuration and camera orbits. The software and its version used in each institution also varied. The working group database was applied to detect the culprit coronary territory from a total of 166 patients with coronary artery disease (CAD) and 145 patients with lowlikelihood of CAD. Results When summed stress score C4 was defined as significant abnormality, overall sensitivity, specificity and accuracy of patient-based analysis were 77, 72 and 75%, respectively, based on quantitative analysis using the common database, whereas those by institutional visual expert reading were 72, 79 and 75%, respectively. Conclusion The common database, which was created by a multi-center working group and separated between male/ female with 180/360° acquisitions, demonstrated comparable diagnostic accuracy to expert interpretation by each institute, and it may be applicable to multi-center studies

Standardization of the heart-to-mediastinum ratio of 123I- labelled-metaiodobenzylguanidine uptake using the dual energy window method: Feasibility of correction with different camera-collimator combinations

金沢大学附属病院核医学診療科Background: Although the heart-to-mediastinum (H/M) ratio in a planar image has been used for practical quantification in 123I- metaiodobenzylguanidine (MIBG) imaging, standardization of the parameter is not yet established. We hypothesized that the value of the H/M ratio could be standardized to the various camera-collimator combinations. Methods and results: Standard phantoms consisting of the heart and mediastinum were made. A low-energy high-resolution (LEHR) collimator and a medium-energy (ME) collimator were used. We examined multi-window correction methods with 123I- dual-window (IDW) acquisition, and planar images were obtained with IDW correction and the LEHR collimator. The images were obtained using the following gamma camera systems: GCA 9300A (Toshiba, Tokyo), E.CAM Signature (Toshiba/Siemens, Tokyo) and Varicam (GE, Tokyo). Cardiac phantom studies demonstrated that contamination of the H/M count ratio was greater with the LEHR collimator and least with the ME collimator. The corrected H/M ratio with the LEHR collimator was similar to that with ME collimators. The uncorrected H/M ratio with the ME collimator was linearly related to the H/M ratio with IDW correction with the LEHR collimator. The relationship between the uncorrected H/M ratios determined with the LEHR (E.CAM) and the ME collimators was y = 0.56x + 0.49, where y = H/M ratio with the E.CAM and x = H/M ratio with the ME collimator. The average normal values for the low-energy collimator (n=18) were 2.2±0.2 (initial H/M ratio) and 2.42±0.2 (delayed H/M ratio), and for the low/medium-energy (LME) collimator (n=14) were 2.63±0.25 (initial H/M ratio) and 2.87±0.19 (delayed H/M ratio). H/M ratios in previous clinical studies using LEHR collimators are comparable to those with ME collimators. Conclusion: The IDW-corrected H/M ratios determined with the LEHR collimator were similar to those determined with the ME collimator. This finding could make it possible to standardize the H/M ratio in planar imaging among various collimators in the clinical setting. © 2008 Springer-Verlag

Changes in cardiac sympathetic nerve innervation and activity in pathophysiologic transition from typical to end-stage hypertrophic cardiomyopathy

金沢大学大学院医学系研究科Left ventricular (LV) systolic function in hypertrophic cardiomyopathy (HCM) is usually normal. Late in the disease, however, LV systolic dysfunction and dilatation are recognized. Although abnormalities in cardiac sympathetic nerve activity in patients with HCM have been demonstrated using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, the changes of cardiac sympathetic nerve activity throughout the clinical course from typical to end-stage HCM are unclear. The objective of this study was to evaluate the relationship between abnormalities on 123I-MIBG myocardial scintigraphy and pathophysiologic changes in patients with HCM. Methods: We performed 123I-MIBG scintigraphy on 46 patients with HCM and 18 age-matched control subjects. The patients were categorized into 3 groups: 28 patients with normal LV systolic function (group A), 9 patients with LV systolic dysfunction (group B), and 9 patients with LV systolic dysfunction and dilatation (group C). With planar 123I-MIBG imaging, the heart-to-mediastinum ratio for early and delayed acquisitions and the washout rate were calculated. With SPECT, polar maps of the LV myocardium were divided into 20 segments. The regional uptake and washout rate were calculated from semiquantitative 20-segment bull\u27s-eye analysis. Results: The early uptake was significantly lower in group C than in the control group (P < 0.01). The washout rate was progressively higher in group A, group B, and group C (P < 0.01). Reduced regional early uptake was found in 2.9 ± 3.4 (group A), 4.1 ± 4.7 (group B), and 7.4 ± 4.3 (group C) segments, respectively. In group C, regional early uptake was significantly reduced, predominantly in the interventricular septal wall, and regional washout rate was increased in the apex and lateral wall. Conclusion: These results suggest that cardiac sympathetic nerve abnormalities in patients with HCM may advance with development of LV systolic dysfunction and dilatation and that 123I-MIBG myocardial scintigraphy may be a useful tool for the evaluation of pathophysiologic changes in HCM