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Objective: It has been proposed that cerebral blood flow (CBF) response to acetazolamide may be reduced according to the degree of autoregulatory vasodilation in regions with normal oxygen extraction fraction (OEF), whereas the CBF response may be absent in regions with increased OEF where vasodilation may be maximal in response to reduced perfusion pressure. The objective of this study was to test this hypothesis.Methods: Positron emission tomography (PET) was used to study 30 symptomatic patients with carotid artery steno-occlusive lesions. CBF at baseline and 10 minutes after an intravenous injection of 1 g acetazolamide was measured. The correlation between the change in CBF during acetazolamide administration and the baseline value of OEF in the affected hemisphere was examined.Results: The baseline OEF value was inversely and non-linearly correlated with the percentage change in CBF during acetazolamide administration (R(2) = 0.25, p = 0.02). There was an upward trend of OEF with diminishing acetazolamide response below a critical level around zero response. Acetazolamide response less than 6.65% over baseline (sensitivity 100%, specificity 89%, positive predictive value 50%, negative predictive value 100%) was established as most helpful in predicting abnormally high OEF.Conclusions: The inverse, non-linear relationship between OEF and CBF response to acetazolamide suggests that these two measurements may not identify haemodynamic impairment in the same patients. [ABSTRACT FROM AUTHOR]

In order to understand the effect of alloying elements on the damage structure evolution in metals, defect clusters near Hf in Ni were studied using the perturbed angular correlation (PAC) technique and positron annihilation spectroscopy (PAS). The volume size factor of Hf in Ni was determined to be 61% by measuring the lattice parameter. The positron annihilation mean lifetime of Ni–0.5 at.%Hf after neutron irradiation at 473 K up to a dose of 0.0053 dpa was 132 ps. The lifetime decreased with increasing annealing temperature and by annealing at 723 K the recovery was finished. The PAC spectrum of 181Ta (←181Hf) taken after the irradiation indicated that there were two components. The first component consisted of a Larmor frequency of 534 mega-radian/s (Mrad/s). The second consisted of a very broad range of frequencies which brought destructive interference among them and made the contribution to the spectrum almost zero. The component disappeared with annealing at 873 K. It was concluded that the first component and the second component represent Hf in the regular substitutional site and Hf with defect clusters, respectively. From the difference of annealing out temperature of defect clusters, clusters annihilated by 723 K were assigned as stacking fault tetrahedra (SFTs) and those by 873 K as interstitial clusters. [Copyright &y& Elsevier]

Various molecular processes including unfolded protein response, protein transport, synaptic transmission and transcription are implicated in the pathology of polyglutamine diseases caused by the expanded polyglutamine-containing proteins. More than 20 transcription-related factors have been reported to interact with disease proteins, and the pathological interaction is known to repress gene expression. The whole shape of nuclear events evoked by disease proteins is now emerging with information on these transcription-related factors and with findings on the similarity between nuclear bodies and pathological inclusion bodies. This article reviews ‘transcription theory’, a rapidly growing hypothesis in polyglutamine diseases. [ABSTRACT FROM AUTHOR]

Evidence that febrile seizures have a strong genetic predisposition has been well documented. In families of probands with multiple febrile convulsions, an autosomal dominant inheritance with reduced penetrance is suspected. Four candidate loci for febrile seizures have been suggested to date; FEB1 on 8q13–q21, FEB2 on 19p, FEB3 on 2q23–q24, and FEB4 on 5q14–15. A missense mutation was identified in the voltage-gated sodium (Na+)-channel β1 subunit gene, SCN1B at chromosome 19p13.1 in generalized epilepsy with the febrile seizures plus type 1 (GEFS+1) family. Several missense mutations of the (Na+)-channel α1 subunit (Nav1.1) gene, SCN1A were also identified in GEFS+2 families at chromosome 2q23–q24.3. The aim of this report is precisely to describe the phenotypes of Japanese patients with novel SCN1A mutations and to reevaluate the entity of GEFS+. Four family members over three generations and one isolated (phenotypically sporadic) case with SCN1A mutations were clinically investigated. The common seizure type in these patients was febrile and afebrile generalized tonic–clonic seizures (FS+). In addition to FS+, partial epilepsy phenotypes were suspected in all affected family members and electroencephalographically confirmed in three patients of two families. GEFS+ is genetically and clinically heterogenous, and associated with generalized epilepsy and partial epilepsy as well. The spectrum of GEFS+ should be expanded to include partial epilepsies and better to be termed autosomal dominant epilepsy with febrile seizures plus (ADEFS+). [Copyright &y& Elsevier]

Aim: To evaluate the capability of integrated 2-[18F]-fluoro-2-deoxy-d-glucose (FDG)-positron-emission tomography (PET)/magnetic resonance imaging (MRI) to characterise the distinct phenotypes of endometrial cancer.Materials and Methods: Thirty-one patients with endometrial cancer (23 with type I, including 17 G1 and six G2 endometrioid adenocarcinomas, and eight with type II, including three G3 endometrioid adenocarcinomas, two carcinosarcomas, and three serous carcinomas) underwent pretreatment FDG-PET/MRI with simultaneous reduced field-of-view diffusion-weighted imaging (DWI). The standardised uptake value (SUV), apparent diffusion coefficient (ADC), and SUV-to-ADC ratio were compared between low-risk (type I and stage I and negative for lymph-vascular space invasion [LVSI]) and high-risk cancers. The diagnostic accuracy for discriminating the cancer phenotypes was evaluated using receiver operating characteristic (ROC) analysis.Results: The SUV was not significantly different between low-risk and high-risk endometrial cancers. High-risk cancers had a significantly lower ADC (756±232×10-6) and a greater SUV-to-ADC ratio (21.7±7.7×109) than low-risk cancers (937±154×10-6, p<0.05 and 13.1±4.1×109, p<0.005, respectively). On comparison of the area under the ROC curves (AUCs), the SUV-to-ADC ratio demonstrated the greatest diagnostic accuracy (ratio 0.83, ADC 0.72, and SUV 0.66). The AUCs for the ratios were significantly higher than those for the SUV values (p<0.05). The optimal SUV-to-ADC cut-off value of 16.9×109 for predicting high-risk cancer revealed a sensitivity of 73%, specificity of 81%, and accuracy of 77%, which was significantly higher than the accuracy for SUV.Conclusion: The SUV-to-ADC ratio obtained using integrated FDG-PET/MRI with high-resolution DWI reflects tumour aggressiveness including LVSI, and will be useful for lesion characterisation to decide on an appropriate therapeutic strategy for endometrial cancer. [ABSTRACT FROM AUTHOR]

Presents a systems study on global high-data-rate satellite communications. Mission of the experimental Gigabit communications satellite; Key technologies for the Gigabit satellite; Ka-band scanning sport beams; On-board asynchronous transfer mode systems; Intersatellite laser links; Concept of the experimental Gigabit satellite communications payload.

This article outlines the role of 16α-[18F]fluoro-17β-oestradiol (18F-FES) positron emission tomography (PET) combined with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) in patients with oestrogen-related tumours for evaluating tumour phenotype. 18F-FES-PET combined with 18F-FDG is helpful in characterising the distinct phenotypic features of oestrogen-related tumours; that is, inter- and intrapatient tumour heterogeneity, which indicates its great potential as a determinant of individualised treatment and a prognostic predictor for patients with oestrogenrelated tumours. [ABSTRACT FROM AUTHOR]

Study Design: Evaluation of cervical spinal cord (CSC) of patients with compressive myelopathy by magnetic resonance imaging (MRI) and high-resolution (18F)fluoro-deoxyglucose (18FDG) positron emission tomography (PET). Objective: To determine changes in morphology, intramedullary signal intensity, and glucose metabolic rate in CSC after decompression, and to assess the utility of 18FDG-PET in evaluation of patients with cervical myelopathy. Summary Of Background Data: The significance of CSC enlargement after decompression and signal intensity changes within the cord remain elusive. No data are available on metabolic activity of the compressed CSC. Only a few studies have examined correlation between high-resolution MRI and 18FDG-PET neuroimaging in cervical myelopathy. Methods: We studied 24 patients who underwent cervical decompressive surgery in terms of postoperative neurologic improvement and changes in MRI and 18FDG-PET. Neurologic status was assessed by the Japanese Orthopedic Association scoring system (17-point scale). Signal intensity change in the cord was qualitatively assessed on both T1- and T2-weighted images. The transverse area of the CSC on MRIs and glucose metabolic rate (standardized uptake value [SUV]) from 18FDG-PET were measured digitally. Results: Neurologic improvement correlated with preoperative CSC transverse area at maximal compression (P < 0.01) and at follow-up (P < 0.001) and with mean SUV before surgery (P < 0.01) and at follow-up (P < 0.05). Preoperative signal intensity change on MRIs (low intramedullary signal intensity abnormality on T1-weighted image and high intramedullary on T2-weighted image) correlated negatively with neurologic improvement rate (P < 0.05). The transverse area of the CSC was significantly smaller after surgery in patients with preoperative MRI signal intensity changes (P < 0.05). The SUV at follow-up tended to normalize in association with neurologic improvement. Conclusion: Our results showed that postoperative neurologic improvement in patients with cervical compressive myelopathy correlated with increased transverse area of the spinal cord, signal intensity change on both T1- and T2-weighted image, and the mean SUV. [ABSTRACT FROM AUTHOR]

We developed remaining service life diagnostic technology of phenol insulators for circuit breakers. Phenol insulators were analyzed by chemical evaluation such as ion concentration and coloration, and the results were diagnosed by the Mahalanobis-Taguchi system (MTS), which is a pattern information technology. Particularly effective items for diagnosis included ions of nitric acid, sulfuric acid, chloride, and calcium. Since there was a good relationship between the results diagnosed by MIS and the actual measurement results of surface resistivity, we found that applying MIS to the chemical evaluation results allowed deterioration diagnosis of phenol insulators instead of surface resistivity, which couldn't be measured on-site. Time was defined as the end of the service life when electrical discharge was initiated and remaining service life was predicted. The linear relationship (master curve of service life) was clarified between the real number value of elapsed time and the logarithmic value of surface resistivity at 50% RH, and remaining service life was predicted from the diagnosis results by MIS and the year in which the master curve and the threshold value intersect. Surface resistivity (threshold value) for electrical discharge initiation was derived from creepage distance, permittivity of phenol insulators, frequency, etc. We substantiated that the remaining service life of the phenol insulators could be predicted by this technology because a good relationship existed between the check examination results of the electric discharge initiation in the laboratory and the prediction results. [ABSTRACT FROM AUTHOR]

Background: In internal carotid artery (ICA) occlusion, increased oxygen extraction fraction (OEF) indicates inadequate collateral blood flow distal to the occlusion, which may be caused by poor function of collateral pathways. In ICA occlusion, the circle of Willis may be the major collateral pathway, while the collaterals through the ophthalmic artery and leptomeningeal vessels may be recruited when collateral flow through the circle of Willis is inadequate. Conversely, ischaemic lesions may affect the adequacy of collateral blood flow by reducing the metabolic demand of the brain. Objective: To determine whether the pattern of collateral pathways and the type of infarcts are independent predictors of OEF in ICA occlusion. Methods: We studied 42 patients with symptomatic ICA occlusion. The presence of Willisian, ophthalmic, or leptomeningeal collaterals was evaluated by conventional four vessel angiography. The infarcts on magnetic resonance imaging were categorised as territorial, border zone (external or internal), striatocapsular, lacunar, and other white matter infarcts. The value of OEF in the affected hemisphere was measured with positron emission tomography as an index of haemodynamic impairment. Results: Using multivariate analysis, the presence of any ophthalmic or leptomeningeal collaterals and the absence of striatocapsular infarcts were significant and independent predictors of increased OEF. Conclusions: In patients with symptomatic ICA occlusion, the supply of collateral flow, which is affected by the pattern of collateral pathways, and the metabolic demand of the brain, which is affected by the type of infarct, may be important factors determining the severity of haemodynamic impairment. [ABSTRACT FROM AUTHOR]

Unlabelled: Two preterm infants with extensive periventricular leukomalacia (PVL) were examined by [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) at the corrected ages of 18 and 34 days. They showed similar clinical courses including oculoclonic seizure, hypsarrhythmia and severe mental retardation, in addition, to spastic quadriplegia. FDG-PET study of these two infants with severe PVL disclosed poorly developed metabolic activity in the primary sensorimotor cortex, while the MRI images displayed only periventricular white matter lesions.Conclusions: Positron emission tomography may disclose cortical involvement in infants with severe periventricular leukomalacia. [ABSTRACT FROM AUTHOR]

Two preterm infants with extensive periventricular leukomalacia (PVL) were examined by [[sup 18] F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) at the corrected ages of 18 and 34 days. They showed similar clinical courses including oculoclonic seizure, hypsarrhythmia and severe mental retardation, in addition to spastic quadriplegia. FDG-PET study of these two infants with severe PVL disclosed poorly developed metabolic activity in the primary sensorimotor cortex, while the MRI images displayed only periventricular white matter lesions.Conclusion Positron emission tomography may dis-close cortical involvement in infants with severe periventricular leukomalacia. [ABSTRACT FROM AUTHOR]