Modulation index predicts the effect of ethosuximide on developmental and epileptic encephalopathy with spike-and-wave activation in sleep.

PURPOSE: In developmental and epileptic encephalopathy with spike-and-wave activation in sleep (DEE-SWAS), the thalamocortical network is suggested to play an important role in the pathophysiology of the progression from focal epilepsy to DEE-SWAS. Ethosuximide (ESM) exerts effects by blocking T-type calcium channels in thalamic neurons. With the thalamocortical network in mind, we studied the prediction of ESM effectiveness in DEE-SWAS treatment using phase-amplitude coupling (PAC) analysis. METHODS: We retrospectively enrolled children with DEE-SWAS who had an electroencephalogram (EEG) recorded between January 2009 and September 2022 and were prescribed ESM at Okayama University Hospital. Only patients whose EEG showed continuous spike-and-wave during sleep were included. We extracted 5-min non-rapid eye movement sleep stage N2 segments from EEG recorded before starting ESM. We calculated the modulation index (MI) as the measure of PAC in pair combination comprising one of two fast oscillation types (gamma, 40-80 Hz; ripples, 80-150 Hz) and one of five slow-wave bands (delta, 0.5-1, 1-2, 2-3, and 3-4 Hz; theta, 4-8 Hz), and compared it between ESM responders and non-responders. RESULTS: We identified 20 children with a diagnosis of DEE-SWAS who took ESM. Fifteen were ESM responders. Regarding gamma oscillations, significant differences were seen only in MI with 0.5-1 Hz slow waves in the frontal pole and occipital regions. Regarding ripples, ESM responders had significantly higher MI in coupling with all slow waves in the frontal pole region, 0.5-1, 3-4, and 4-8 Hz slow waves in the frontal region, 3-4 Hz slow waves in the parietal region, 0.5-1, 2-3, 3-4, and 4-8 Hz slow waves in the occipital region, and 3-4 Hz slow waves in the anterior-temporal region. SIGNIFICANCE: High MI in a wider area of the brain may represent the epileptic network mediated by the thalamus in DEE-SWAS and may be a predictor of ESM effectiveness.

Centrifugal Field-Flow Fractionation Enables Detection of Slight Aggregation of Nanoparticles That Impacts Their Biomedical Applications.

Nanoparticles (NPs) are anticipated to be used for various biomedical applications in which their aggregation has been an important issue. However, concerns regarding slightly aggregated but apparently monodispersed NPs have been difficult to address because of a lack of appropriate evaluation methods. Here, we report centrifugal field-flow fractionation (CF3) as a powerful method for analyzing the slight aggregation of NPs, using antibody-modified gold NPs (Ab-AuNPs) prepared by a conventional protocol with centrifugal purification as a model. While common evaluation methods such as dynamic light scattering cannot detect significant signs of aggregation, CF3 successfully detects distinct peaks of slightly aggregated NPs, including dimers and trimers. Their impact on biological interactions was also demonstrated by a cellular uptake study: slightly aggregated Ab-AuNPs exhibited 1.8 times higher cellular uptake than monodispersed Ab-AuNPs. These results suggest the importance of aggregate evaluation via CF3 as well as the need for careful attention to the bioconjugation procedures for NPs.

Improving image quality using the pause function combination to PROPELLER sequence in brain MRI: a phantom study.

While some MRI systems offer a "pause" function, combining it with the PROPELLER method for image quality improvement remains underexplored. This study investigated whether repositioning the head after pausing during PROPELLER imaging enhances image quality. All brain phantom images in this study were obtained using a 3.0 T MRI and acquired using the fast spin-echo T2WI-based PROPELLER with motion correction. By combining the angle of rotational motion of the head phantom and the number of repositioning after a pause, two studies including seven trials were performed. Increasing the rotation angle decreased the image quality; however, pausing the image and repositioning the head phantom to the original angle improved the image quality. A similar result was obtained by repositioning the angle closer to its original angle. Experiments with multiple head movements showed that pausing the scan and repositioning the phantom with each movement improved image quality.

Exploration of urine metabolic biomarkers for new-onset, untreated pediatric epilepsy: A gas and liquid chromatography mass spectrometry-based metabolomics study.

OBJECTIVE: The discovery of objective indicators for recent epileptic seizures will help confirm the diagnosis of epilepsy and evaluate therapeutic effects. Past studies had shortcomings such as the inclusion of patients under treatment and those with various etiologies that could confound the analysis results significantly. We aimed to minimize such confounding effects and to explore the small molecule biomarkers associated with the recent occurrence of epileptic seizures using urine metabolomics. METHODS: This is a multicenter prospective study. Subjects included pediatric patients aged 2 to 12 years old with new-onset, untreated epilepsy, who had had the last seizure within 1 month before urine collection. Controls included healthy children aged 2 to 12 years old. Those with underlying or chronic diseases, acute illnesses, or recent administration of medications or supplements were excluded. Targeted metabolome analysis of spot urine samples was conducted using gas chromatography (GC)- and liquid chromatography (LC)-tandem mass spectrometry (MS/MS). RESULTS: We enrolled 17 patients and 21 controls. Among 172 metabolites measured by GC/MS/MS and 41 metabolites measured by LC/MS/MS, only taurine was consistently reduced in the epilepsy group. This finding was subsequently confirmed by the absolute quantification of amino acids. No other metabolites were consistently altered between the two groups. CONCLUSIONS: Urine metabolome analysis, which covers a larger number of metabolites than conventional biochemistry analyses, found no consistently altered small molecule metabolites except for reduced taurine in epilepsy patients compared to healthy controls. Further studies with larger samples, subjects with different ages, expanded target metabolites, and the investigation of plasma samples are required.

Effective Epilepsy Surgery for Post-Traumatic West Syndrome Following Abusive Head Trauma.

West syndrome, an infantile developmental and epileptic encephalopathy with a deleterious impact on long-term development, requires early treatment to minimize developmental abnormality; in such cases, epilepsy surgery should be considered a powerful therapeutic option. We describe a 10-month-old female admitted with West syndrome associated with a hemispheric lesion following abusive head trauma. Her seizures were suppressed by hemispherotomy at 12 months of age, leading to developmental improvement. Surgical treatment of West syndrome following traumatic brain injury has not been reported previously but is worth considering as a treatment option, depending on patient age and brain plasticity.

A female patient with adolescent-onset progressive myoclonus epilepsy carrying a truncating MECP2 mutation.

BACKGROUND: MECP2 is a well-known causative gene for Rett syndrome but other phenotypes have also been reported. Here, we report a case of a female patient with adolescent-onset progressive myoclonus epilepsy (PME) carrying a novel truncating mutation in the MECP2 gene. CASE REPORT: The patient was a 29-year-old woman with infantile-onset intellectual disability of unspecified cause. She had demonstrated slow but steady development with moderate intellectual disability until the age of 16, when she started having epileptic seizures. Her epilepsy progressed intractably with multiple seizure types accompanied by myoclonus, tremor, and gradual regression. She is currently apathetic and requires extensive assistance in all aspects of life. After an extensive work-up for underlying diseases for PME turned out negative, whole-exome sequencing revealed a de novo 113-bp deletion and 3-bp insertion in MECP2, a variant of NM_004992.4:c.1099_1211delinsGGG, p.(His367Glyfs*32). CONCLUSIONS: The clinical presentation of this case was inconsistent with Rett syndrome, and the rapid regression in the patient's twenties was considered characteristic. Mutations of MECP2 may result in variable neurodevelopmental phenotypes and may also be considered a causative gene for adolescent-onset PME.

A case of giant cell myocarditis mimicking cardiac sarcoidosis successfully maintained by prednisolone and tacrolimus.

A 45-year-old woman with no medical history underwent pacemaker implantation for a symptomatic complete atrioventricular block. On day 6, she noticed diplopia and then fever, general malaise, and elevation of serum creatinine kinase (CK). She was transferred to our hospital on day 21. Serum CK was elevated to 4543 IU/L, and echocardiography revealed a left ventricular ejection fraction of 43 %. We diagnosed her with giant cell myocarditis (GCM) via an emergent myocardial biopsy that revealed a proliferation of lymphocytes, eosinophils, and giant cells without granulomas. Initial treatment with high doses of intravenous methylprednisolone and immunoglobulin improved her symptoms in a few days, and prednisolone was given as follow-up treatment. CK was normalized in a week and a thinning of the interventricular septum mimicking cardiac sarcoidosis (CS) occurred. On day 38, we added a calcineurin inhibitor, tacrolimus, and maintained her with a combination of prednisolone and tacrolimus at a target dose of 10-15 ng/mL. Six months after the onset, there were no signs of relapse despite the persistent mild elevation of troponin I levels. We present a case of GCM mimicking CS successfully maintained by a combination of two immunosuppressive agents. Learning objective: Recommended treatment for giant cell myocarditis (GCM), a potentially fatal disease, is a combination of three immunosuppressive agents. However, GCM shares many characteristics with cardiac sarcoidosis (CS), which is treated using prednisolone alone in many cases. Recent studies on GCM and CS suggest they are different spectrums of a common entity. Although they can clinically overlap, they have different progressive speeds and severities. We present a case of GCM mimicking CS successfully treated with a combination of two immunosuppressive agents.

Comprehensive study of metabolic changes induced by a ketogenic diet therapy using GC/MS- and LC/MS-based metabolomics.

OBJECTIVE: The ketogenic diet (KD), a high-fat and low-carbohydrate diet, is effective for a subset of patients with drug-resistant epilepsy, although the mechanisms of the KD have not been fully elucidated. The aims of this observational study were to investigate comprehensive short-term metabolic changes induced by the KD and to explore candidate metabolites or pathways for potential new therapeutic targets. METHODS: Subjects included patients with intractable epilepsy who had undergone the KD therapy (the medium-chain triglyceride [MCT] KD or the modified Atkins diet using MCT oil). Plasma and urine samples were obtained before and at 2-4 weeks after initiation of the KD. Targeted metabolome analyses of these samples were performed using gas chromatography-tandem mass spectrometry (GC/MS/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). RESULTS: Samples from 10 and 11 patients were analysed using GC/MS/MS and LC/MS/MS, respectively. The KD increased ketone bodies, various fatty acids, lipids, and their conjugates. In addition, levels of metabolites located upstream of acetyl-CoA and propionyl-CoA, including catabolites of branched-chain amino acids and structural analogues of γ-aminobutyric acid and lactic acid, were elevated. CONCLUSIONS: The metabolites that were significantly changed after the initiation of the KD and related metabolites may be candidates for further studies for neuronal actions to develop new anti-seizure medications.

Intraocular Water Movement Visualization Using 1 H-MRI With Eye Drops of O-17-Labeled Saline: First-in-Human Study.

BACKGROUND: Visualization of aqueous humor flow in MR contrast images using gadolinium is challenging because of the delayed contrast effects associated with the blood-retinal and blood-aqueous humor barriers. However, oxygen-17 water (H2 17 O) might be used as an ocular contrast agent. PURPOSE: To observe the distribution of H2 17 O in the human eye, and its flow in and out of the anterior chamber, using dynamic T2-weighted MRI. STUDY TYPE: Prospective. POPULATION: Six ophthalmologically normal volunteers (20-37 years, six females). FIELD STRENGTH/SEQUENCE: A 3 T/dynamic T2-weighted MRI. ASSESSMENT: H2 17 O eye drops were administered to the right eye. Time-series images were created by subtracting the image before the eye drops from each of the images obtained after the eye drops. The normalized signal intensity of the right anterior chamber (nAC) was obtained by dividing the signal intensity of the right anterior chamber region by that of the left. The inflow and outflow constants of H2 17 O and H2 17 O concentration were calculated from the nAC. STATISTICAL TESTS: A paired t-test was used to compare the flow-related values and temporal changes in signal intensity. P-values < 0.05 were considered statistically significant. RESULTS: Significantly decreased signal intensity was observed in the right anterior chamber but not the right vitreous body (P = 0.39). The nAC signal intensity decreased significantly and then recovered. The inflow and outflow constants were 0.36-0.94 min-1 and 0.023-0.13 min-1 , respectively. The maximum H2 17 O concentration was 0.078%-0.24%. DATA CONCLUSION: H2 17 O were distributed in the anterior chamber. The H2 17 O inflow into the anterior chamber was significantly faster than that of the outflow. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

Artificial Intelligence-based Detection of Epileptic Discharges from Pediatric Scalp Electroencephalograms: A Pilot Study.

We developed an artificial intelligence (AI) technique to identify epileptic discharges (spikes) in pediatric scalp electroencephalograms (EEGs). We built a convolutional neural network (CNN) model to automatically classify steep potential images into spikes and background activity. For the CNN model' training and validation, we examined 100 children with spikes in EEGs and another 100 without spikes. A different group of 20 children with spikes and 20 without spikes were the actual test subjects. All subjects were ≥ 3 to < 18 years old. The accuracy, sensitivity, and specificity of the analysis were >0.97 when referential and combination EEG montages were used, and < 0.97 with a bipolar montage. The correct classification of background activity in individual patients was significantly better with a referential montage than with a bipolar montage (p=0.0107). Receiver operating characteristic curves yielded an area under the curve > 0.99, indicating high performance of the classification method. EEG patterns that interfered with correct classification included vertex sharp transients, sleep spindles, alpha rhythm, and low-amplitude ill-formed spikes in a run. Our results demonstrate that AI is a promising tool for automatically interpreting pediatric EEGs. Some avenues for improving the technique were also indicated by our findings.

Dual-Energy Computed Tomography-Based Iodine Concentration Estimation for Evaluating Choroidal Malignant Melanoma Response to Treatment: Optimization and Primary Validation.

Contrast-enhanced imaging for choroidal malignant melanoma (CMM) is mostly limited to detecting metastatic tumors, possibly due to difficulties in fixing the eye position. We aimed to (1) validate the appropriateness of estimating iodine concentration based on dual-energy computed tomography (DECT) for CMM and optimize the calculation parameters for estimation, and (2) perform a primary clinical validation by assessing the ability of this technique to show changes in CMM after charged-particle radiation therapy. The accuracy of the optimized estimate (eIC_optimized) was compared to an estimate obtained by commercial software (eIC_commercial) by determining the difference from the ground truth. Then, eIC_optimized, tumor volume, and CT values (80 kVp, 140 kVp, and synthesized 120 kVp) were measured at pre-treatment and 3 months and 1.5−2 years after treatment. The difference from the ground truth was significantly smaller in eIC_optimized than in eIC_commercial (p < 0.01). Tumor volume, CT values, and eIC_optimized all decreased significantly at 1.5−2 years after treatment, but only eIC_commercial showed a significant reduction at 3 months after treatment (p < 0.01). eIC_optimized can quantify contrast enhancement in primary CMM lesions and has high sensitivity for detecting the response to charged-particle radiation therapy, making it potentially useful for treatment monitoring.

A Case of Chronic Heart Failure Complicated by Primary Biliary Cholangitis and Skeletal Myopathy.

Several autoantigens related to inflammatory myopathy have been identified. Antimitochondrial antibody M2 (AMA-M2) is known as one of the serologic hallmarks of primary biliary cholangitis (PBC). There have been several reports on the association between AMA-M2 and various types of inflammatory myopathy, including cardiomyopathy. We report a case of a 58-year-old man with decompensated heart failure who also had PBC and skeletal inflammatory myopathy. Endomyocardial biopsy revealed severe fibrotic replacement of the myocardium without massive inflammatory infiltration, which was pathologically similar to what happens in dilated cardiomyopathy (DCM). Although the potential relationship between chronic autoimmune inflammation and DCM has been discussed, the concept of the inflammatory DCM has not yet been established. When we see elevated liver enzymes, and which is not simply due to congestive hepatopathy, we should consider the coexisting disease such as PBC.

Long-Term Outcomes in Patients with Not-Retrieval Inferior Vena Cava Filter Under Anticoagulation.

Since permanent inferior vena cava (IVC) filters increase deep vein thrombosis (DVT), filter retrieval should be performed as possible. Despite the guideline recommendation, IVC filters are not always retrieved in clinical practice. To date, many patients with not-retrieval IVC filters have been prescribed anticoagulant therapy, but the long-term prognosis, including venous thromboembolism (VTE) and bleeding events, remains unknown. In this study, 195 patients who underwent IVC filter implantation between 2006 and 2017 at 3 institutions in Niigata City have been investigated about their deaths, VTE recurrence, and bleeding events. After peaking 2009, the number of IVC filter implantation gradually decreased. During observational period, there were 158 patients with not-retrieval IVC filters (the overall retrieval rate of 19.0%). The not-retrieval group included significantly older and more patients with cancer compared to the retrieval group. Anticoagulation therapy was continued in 88% of the not-retrieval group. During a mean follow-up of 5.0 years, 6 symptomatic DVT events associated with inadequate control of anticoagulation and 13 bleeding events were observed. A total of 52 patients died and only the presence of cancer was prognostic risk factor. Although long-term anticoagulation therapy may be associated with bleeding events, there were few recurrent VTE under optimal anticoagulation. It is anticipated that even if the IVC filter cannot be retrieved, appropriate anticoagulation is useful for prevention of DVT recurrence despite the risk of bleeding.

Exclusion of the Possibility of "False Ripples" From Ripple Band High-Frequency Oscillations Recorded From Scalp Electroencephalogram in Children With Epilepsy.

AIM: Ripple-band epileptic high-frequency oscillations (HFOs) can be recorded by scalp electroencephalography (EEG), and tend to be associated with epileptic spikes. However, there is a concern that the filtration of steep waveforms such as spikes may cause spurious oscillations or "false ripples." We excluded such possibility from at least some ripples by EEG differentiation, which, in theory, enhances high-frequency signals and does not generate spurious oscillations or ringing. METHODS: The subjects were 50 pediatric patients, and ten consecutive spikes during sleep were selected for each patient. Five hundred spike data segments were initially reviewed by two experienced electroencephalographers using consensus to identify the presence or absence of ripples in the ordinary filtered EEG and an associated spectral blob in time-frequency analysis (Session A). These EEG data were subjected to numerical differentiation (the second derivative was denoted as EEG″). The EEG″ trace of each spike data segment was shown to two other electroencephalographers who judged independently whether there were clear ripple oscillations or uncertain ripple oscillations or an absence of oscillations (Session B). RESULTS: In Session A, ripples were identified in 57 spike data segments (Group A-R), but not in the other 443 data segments (Group A-N). In Session B, both reviewers identified clear ripples (strict criterion) in 11 spike data segments, all of which were in Group A-R (p < 0.0001 by Fisher's exact test). When the extended criterion that included clear and/or uncertain ripples was used in Session B, both reviewers identified 25 spike data segments that fulfilled the criterion: 24 of these were in Group A-R (p < 0.0001). DISCUSSION: We have demonstrated that real ripples over scalp spikes exist in a certain proportion of patients. Ripples that were visualized consistently using both ordinary filters and the EEG″ method should be true, but failure to clarify ripples using the EEG″ method does not mean that true ripples are absent. CONCLUSION: The numerical differentiation of EEG data provides convincing evidence that HFOs were detected in terms of the presence of such unusually fast oscillations over the scalp and the importance of this electrophysiological phenomenon.

A study on the relationship between non-epileptic fast (40 - 200 Hz) oscillations in scalp EEG and development in children.

OBJECTIVE: Physiological gamma and ripple activities may be linked to neurocognitive functions. This study investigated the relationship between development and non-epileptic, probably physiological, fast (40-200 Hz) oscillations (FOs) including gamma (40 - 80 Hz) and ripple (80 - 200 Hz) oscillations in scalp EEG in children with neurodevelopmental disorders. METHODS: Participants were 124 children with autism spectrum disorder (ASD) and/or attention deficit/hyperactivity disorder (ADHD). Gamma and ripple oscillations were explored from 60-second-long sleep EEG data in each subject using a semi-automatic detection tool supplemented with visual confirmation and time-frequency analysis. RESULTS: Gamma and ripple oscillations were detected in 25 (20.2%) and 22 (17.7%) children, respectively. The observation of one or more occurrence(s) of ripple oscillations, but not gamma oscillations, was significantly related to lower age at EEG recording (odds ratio, OR: 0.727 [95% confidence interval, CI: 0.568-0.929]), higher intelligence/developmental quotient (OR: 1.041, 95% CI: 1.002-1.082), and lack of a diagnosis with ADHD (OR: 0.191, 95% CI: 0.039 - 0.937) according to a binominal logistic regression analysis that included diagnosis with ASD, sex, history of perinatal complications, history of febrile seizures, and use of a sedative agent for the EEG recording as the other non-significant parameters. Diagnostic group was not related to frequency or power of spectral peaks of FOs. CONCLUSION: The production of non-epileptic scalp ripples was confirmed to be associated with brain development and function/dysfunction in childhood. Further investigation is necessary to interpret all of the information on higher brain functions that may be embedded in scalp FOs.

Effect of growth hormone therapy on thyroid function in isolated growth hormone deficient and short small for gestational age children: a two-year study, including on assessment of the usefulness of the thyrotropin-releasing hormone (TRH) stimulation test.

Background The relationship between growth hormone (GH)-replacement therapy and the thyroid axis in GH-deficient (GHD) children remains controversial. Furthermore, there have been few reports regarding non-GHD children. We aimed to determine the effect of GH therapy on thyroid function in GHD and non-GHD children and to assess whether thyrotropin-releasing hormone (TRH) stimulation test is helpful for the identification of central hypothyroidism before GH therapy. Methods We retrospectively analyzed data from patients that started GH therapy between 2005 and 2015. The free thyroxine (FT4) and thyroid-stimulating hormone (TSH) concentrations were measured before and during 24 months of GH therapy. The participants were 149 children appropriate for gestational age with GHD (IGHD: isolated GHD) (group 1), 29 small for gestational age (SGA) children with GHD (group 2), and 25 short SGA children (group 3). Results In groups 1 and 2, but not in group 3, serum FT4 concentration transiently decreased. Two IGHD participants exhibited central hypothyroidism during GH therapy, and required levothyroxine (LT4) replacement. They showed either delayed and/or prolonged responses to TRH stimulation tests before start of GH therapy. Conclusions GH therapy had little pharmacological effect on thyroid function, similar changes in serum FT4 concentrations were not observed in participants with SGA but not GHD cases who were administered GH at a pharmacological dose. However, two IGHD participants showed central hypothyroidism and needed LT4 replacement therapy during GH therapy. TRH stimulation test before GH therapy could identify such patients and provoke careful follow-up evaluation of serum FT4 and TSH concentrations.

Longitudinal correspondence of epilepsy and scalp EEG fast (40-200 Hz) oscillations in pediatric patients with tuberous sclerosis complex.

INTRODUCTION: Epilepsy associated with tuberous sclerosis complex (TSC) has very complex clinical characteristics. Scalp electroencephalogram (EEG) fast (40-200 Hz) oscillations (FOs) were recently suggested to indicate epilepsy severity. Epileptic FOs may undergo age-dependent longitudinal change in individual patients, however, and the typical pattern of such change is not yet fully clarified. We therefore investigated the age-related correspondence between clinical courses and FOs in pediatric patients with TSC-associated epilepsy. SUBJECTS AND METHODS: FOs were semi-automatically detected from scalp sleep EEG data recorded from 23 children (15 boys, 8 girls; initial data obtained at <10 years of age) with TSC-associated epilepsy. RESULTS: The number of FOs per patient that were associated with spikes was significantly greater than that of FOs unassociated with spikes (median 145 and 5, respectively; p = 0.0001 by the Wilcoxon signed-rank test). In the eight patients who had West syndrome (WS) in infancy, FOs associated with spikes were abundant during the WS period prior to adrenocorticotropic hormone therapy, with significantly greater numbers of FOs compared to the post-WS period (median 242 and 0, respectively; p = 0.0078). As there was no such time-dependent difference regarding FOs unassociated with spikes, FOs associated with spikes were identified as epileptic. The detected FOs included both gamma and ripple oscillations with no consistent age-dependent shifts in dominant frequency. There were no apparent age-related changes in FO duration. CONCLUSIONS: Epileptic scalp FOs are confirmed to correspond to severity of epileptic encephalopathy, particularly in WS, even during the long-term evolutional courses of TSC-associated epilepsy.

Structural origin of high-density Gd2O3-MoO3-B2O3 glass and low-density ß'-Gd2(MoO4)3 crystal: a study conducted using high-energy x-ray diffraction and EXAFS at high temperatures.

In this study, the short- and medium-range ordering of 21.25Gd2O3-63.75MoO3-15B2O3 glass (GM15B glass) was studied at temperatures ranging from 297 K to above the crystallization temperature. This was achieved using extended x-ray absorption fine structure and high-energy x-ray diffraction analyses to elucidate the structural origin of the higher glass density (d) as compared to that of precipitated crystals, i.e. GM15B glass with d = 4.762 g cm-3 and ß'-Gd2(MoO4)3 crystal with d = 4.555 g cm-3, and the self-powdering phenomenon in GM15B glass. The bond lengths in the short-range order, i.e. Gd-O, Mo-O, and Gd-Mo in GM15B, were extremely similar to those in the ß-phase; Gd-Gd and Mo-Mo bonds in Gd-O-Gd and Mo-O-Mo, respectively, were not found. The distance between the Gd-Gd pairs in Gd-O-Mo-O-Gd in GM15B glass, r(Gd-Gd) = 6.19 Å, was considerably smaller than that in ß-Gd2(MoO4)3 crystals (6.71 Å) in the crystallized glass at 808 K. This indicates that the glass had a more packed structure than did the precipitated crystals. The probable origin of the self-powdering phenomenon in GM15B glass was the large expansion of the structure during crystallization, which is due to the formation of an open structure with long Gd-Gd pairs and varying bond angles.