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.

Epilepsy in Children With Congenital Heart Disease: Risk Factors and Characteristic Presentations.

BACKGROUND: Children with a congenital heart disease (CHD) are at a higher risk of developing epilepsy than the general population, but detailed characteristics of CHD-associated epilepsy have not been clarified. The purposes of this study were to determine the risk factors for developing epilepsy associated with CHD and to elucidate the characteristics of such epilepsy. METHODS: We performed a retrospective cohort study based on medical records of pediatric patients with CHD who were born between January 2006 and December 2016, underwent cardiac surgery at Okayama University Hospital, and were followed up until at least age three years. Multivariate logistic regression analysis was used to determine factors particularly associated with epilepsy occurrence. In patients who developed epilepsy, clinical data on seizure characteristics were further investigated. RESULTS: We collected data from 1024 patients, and 41 (4.0%) developed epilepsy. The presence of underlying disease (odds ratio [OR]: 2.413; 95% confidence interval [CI]: 1.150 to 4.883) and the Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery score category 2 (OR: 4.373; 95% CI: 1.090 to 29.150) and category 5 (OR: 10.385; 95% CI: 1.717 to 89.016) were significantly related to epilepsy occurrence. Of the 41 patients with epilepsy, 15 (including nine with hypoplastic left heart syndrome) had focal impaired awareness seizures specified as autonomic seizures with vomiting, which tends to escape detection. CONCLUSIONS: We clarified the risk factors for developing epilepsy in children with CHD. We also found that autonomic seizure with vomiting is an important symptom in these children.

Role of FBXW2 in explant cultures of bovine periosteum-derived cells.

OBJECTIVE: Bone regeneration is a potential technique for treating osteoporosis. A previous study reported that F-box and WD-40 domain-containing protein 2 (FBXW2) localized with osteocalcin in bovine periosteum after 5 weeks of explant culture. However, the osteoblastic functions of FBXW2 remain unclear. In this study, double-fluorescent immunostaining was used to investigate the potential role of FBXW2 and its relationship with osteocalcin. RESULTS: At day 0, FBXW2 was expressed in the cambium layer between the bone and periosteum, while osteocalcin was expressed in bone. After explant culture, changes in the periosteum were observed from weeks 1 to 7. At week 1, partial FBXW2 expression was seen with a small amount of osteocalcin. At week 2, a layer of FBXW2 was observed. From weeks 3 to 7, tube-like structures of FBXW and osteocalcin were observed, and periosteum-derived cells were released from the periosteum in areas where no FBXW2 was observed. Bovine periosteum-derived cells can form a three-dimensional cell pellet, because multilayered cell sheets are formed inside of the periosteum in vitro. It is shown that in results FBXW2 is produced in periosteal explants near sites where initial osteogenic activity is observed, suggesting that it may be involved in periosteal osteogenesis.

Significance of High-frequency Electrical Brain Activity.

　Electroencephalogram (EEG) data include broadband electrical brain activity ranging from infra-slow bands (< 0.1 Hz) to traditional frequency bands (e.g., the approx. 10 Hz alpha rhythm) to high-frequency bands of up to 500 Hz. High-frequency oscillations (HFOs) including ripple and fast ripple oscillations (80-200 Hz and>200 / 250 Hz, respectively) are particularly of note due to their very close relationship to epileptogenicity, with the possibility that they could function as a surrogate biomarker of epileptogenicity. In contrast, physiological high-frequency activity plays an important role in higher brain functions, and the differentiation between pathological / epileptic and physiological HFOs is a critical issue, especially in epilepsy surgery. HFOs were initially recorded with intracranial electrodes in patients with intractable epilepsy as part of a long-term invasive seizure monitoring study. However, fast oscillations (FOs) in the ripple and gamma bands (40-80 Hz) are now noninvasively detected by scalp EEG and magnetoencephalography, and thus the scope of studies on HFOs /FOs is rapidly expanding.

Complex observation of scalp fast (40-150 Hz) oscillations in West syndrome and related disorders with structural brain pathology.

We investigated the relationship between the scalp distribution of fast (40-150 Hz) oscillations (FOs) and epileptogenic lesions in West syndrome (WS) and related disorders. Subjects were 9 pediatric patients with surgically confirmed structural epileptogenic pathology (age at initial electroencephalogram [EEG] recording: mean 7.1 months, range 1-22 months). The diagnosis was WS in 7 patients, Ohtahara syndrome in 1, and a transitional state from Ohtahara syndrome to WS in the other. In the scalp EEG data of these patients, we conservatively detected FOs, and then examined the distribution of FOs. In five patients, the scalp distribution of FOs was consistent and concordant with the lateralization of cerebral pathology. In another patient, FOs were consistently dominant over the healthy cerebral hemisphere, and the EEG was relatively low in amplitude over the pathological atrophic hemisphere. In the remaining 3 patients, the dominance of FOs was inconsistent and, in 2 of these patients, the epileptogenic hemisphere was reduced in volume, which may result from atrophy or hypoplasia. The correspondence between the scalp distribution of FOs and the epileptogenic lesion should be studied, taking the type of lesion into account. The factors affecting scalp FOs remain to be elucidated.

Importance of the multisystem follow-up in patients with tuberous sclerosis complex.

Objective: Tuberous sclerosis complex (TSC) is a multisystem disorder characterized by the formation of hamartoma in multiple organ systems of the body. However, without a well-established cooperative system involving related departments, some organ lesions might be overlooked until symptoms appear or even until the disorder progresses. Therefore, the purpose of this study is to investigate the current status of follow-ups in the TSC patients in the Department of Child Neurology at Okayama University Medical Hospital. Methods: We performed a retrospective chart review of 38 patients with TSC who visited our hospital at least twice between January 2005 and December 2014. Patients were between 3 years and 48 years of age at their latest visit. We divided the patients into a child group and an adult group, and investigated the patients' follow-up data while focusing on the various multiorgan systems. Results: The follow-ups were well conducted in the child group in terms of every organ. In the adult group, neuroimaging tests were unsatisfactorily performed. The kidney has not been examined in seven patients more than five years even though these patients all had kidney lesions. The lung was not been examined in 7 out of 14 female patients over 18 years of age who are most at risk for lymphangioleiomyomatosis (LAM). In 12 out of 18 child patients, echocardiograms were performed every few years, while electrocardiograms to assess underlying conduction defects were rarely performed in either age group. Conclusions: In Europe, guidelines for the management of TSC have been well established. However, in our hospital, the multiorgan system follow-up is not satisfactorily performed especially in adult patients. We decided the establishment of a TSC board in our hospital for the management of this multiorgan disorder.

Simultaneous measurement of monoamine metabolites and 5-methyltetrahydrofolate in the cerebrospinal fluid of children.

BACKGROUND: We describe a new method for simultaneous measurement of monoamine metabolites (3-O-methyldopa [3-OMD], 3-methoxy-4-hydroxyphenylethyleneglycol [MHPG], 5-hydroxyindoleacetic acid [5-HIAA], and homovanillic acid [HVA]) and 5-methyltetrahydrofolate (5-MTHF) and its use on cerebrospinal fluid (CSF) samples from pediatric patients. METHODS: Monoamine metabolites and 5-MTHF were measured by high-performance liquid chromatography with fluorescence detection. CSF samples were prospectively collected from children according to a standardized collection protocol in which the first 1-ml fraction was used for analysis. RESULTS: Monoamine metabolites and 5-MTHF were separated within 10min. They showed linearity from the limit of detection to 1024nmol/l. The limit of quantification of each metabolite was sufficiently low for the CSF sample assay. In 42 CSF samples after excluding cases with possibly altered neurotransmitter profiles, the concentrations of 3-OMD, MHPG, 5-HIAA, HVA, and 5-MTHF showed significant age dependence and their ranges were comparable with the reference values in the literature. The metabolite profiles of aromatic l-amino acid decarboxylase deficiency, Segawa disease, and folate receptor α defect by this method were compatible with those in the literature. CONCLUSIONS: This method is a simple means of measuring CSF monoamine metabolites and 5-MTHF, and is especially useful for laboratories not equipped with electrochemical detectors.

Determination of CSF 5-methyltetrahydrofolate in children and its application for defects of folate transport and metabolism.

OBJECTIVE: To describe an assay of 5-methyltetrahydrofolate (5MTHF) in the cerebrospinal fluid (CSF) of children, to determine reference values, and to report the clinical significance of this assay in metabolic disorders affecting folate transport and metabolism. METHODS: CSF 5MTHF was determined by high-performance liquid chromatography with fluorescent detection in pediatric patients including one with FOLR1 gene mutation and one with methylenetetrahydrofolate reductase (MTHFR) deficiency. CSF total folate was measured using an automated analyzer. RESULTS: 5MTHF and total folate were determined in 188 and 93 CSF samples, respectively. CSF 5MTHF was high throughout the first six months of life and subsequently declined with age. Reference values of CSF 5MTHF and total folate were determined from 162 and 82 samples, respectively. The patient with FOLR1 gene mutation had extremely low CSF 5MTHF and total folate, though these values normalized after folinic acid supplementation. The patient with MTHFR deficiency had extremely low 5MTHF and moderately low total folate; these values were not associated and showed no significant change after folic acid supplementation. CONCLUSIONS: This 5MTHF assay is simple, rapid, sensitive, reliable, and cost-effective. It will aid in the diagnosis and therapeutic monitoring of metabolic disorders affecting folate transport and metabolism.

Spatial relationship between fast and slow components of ictal activities and interictal epileptiform discharges in epileptic spasms.

OBJECTIVE: We analyzed the spatial distribution and concordance of fast (>10Hz) and slow (<5Hz) electroencephalogram (EEG) components of ictal activities and interictal epileptiform discharges (IIED) recorded by intracranial video EEG (IVEEG) in children with epileptic spasms (ES). METHODS: We studied eight children with ES, who underwent IVEEG before resective surgery for epilepsy. We quantified the root-mean-square (RMS) amplitude of the fast and slow components of ictal activities during ES and IIED. We compared the concordance between the spatial distributions of the fast and slow components of ES and IIED. RESULTS: There was a larger concordance between the spatial distributions of the fast and slow components in IIED than in ES (p=0.0206 and 0.0401). CONCLUSIONS: The spatial concordance between the fast and slow EEG components was significantly different between ES and IIED. SIGNIFICANCE: The mechanisms underlying the generation of slow EEG components may differ between ES and IIED. The slow EEG components of ES might indicate an extensive epileptic network involving remote symptomatic zones for ES in either the cortical or subcortical areas. The high spatial concordance between the fast and slow components of IIED suggests the involvement of a local inhibitory process within the epileptic cortex.

Prevalence of anti-phospholipase A2 receptor antibodies in Japanese patients with membranous nephropathy.

BACKGROUND: Membranous nephropathy (MN) is the leading cause of nephrotic syndrome in adults. Anti-M-type phospholipase A2 receptor (anti-PLA2R) antibodies are found in most patients with idiopathic MN (iMN) worldwide, but the prevalence of anti-PLA2R antibodies among Japanese patients with MN is unknown. In this study, we determined the prevalence of anti-PLA2R antibodies in Japanese patients with MN. METHODS: The study population of our retrospective cross-sectional consisted of 131 patients with biopsy-proven MN who had not received any immunosuppressive treatments at time of both renal biopsy and serum sample collection. Of these, 100 had iMN and 31 had secondary MN (sMN). The circulating anti-PLA2R antibodies were analyzed using a highly sensitive Western blot analysis. Analysis was performed under non-reducing conditions with a human glomerular extract at serum dilutions of 1:25, 1:10, and 1 as the primary antibody. RESULTS: Anti-PLA2R antibodies were detected in 53 (53 %) of 100 patients with iMN and 0 (0 %) of 31 patients with sMN. The prevalence of anti-PLA2R antibodies was higher in patients with nephrotic syndrome (61 %) than in patients without nephrotic syndrome (43 %). The number of patients with serum albumin ≤ 3.0 g/dL was significantly higher in those with anti-PLA2R antibodies (92 %) than that in those without them (68 %). CONCLUSIONS: Anti-PLA2R antibodies were found in Japanese patients with iMN; however, the prevalence was lower than that of any other Asian country. This may indicate that the presence of other pathogenic antigens plays a significant role in Japanese patients with iMN.

High kurtosis of intracranial electroencephalogram as a marker of ictogenicity in pediatric epilepsy surgery.

OBJECTIVE: We determined whether kurtosis analysis of intracranial electroencephalogram (EEG) can estimate the localization of the epileptogenic zone. METHODS: We analyzed 29 pediatric epilepsy patients who underwent intracranial EEG before focal resective surgery. We localized the brain regions with high kurtosis, the seizure onset zone (SOZ) and the regions with high-rate, high-amplitude and long-duration interictal paroxysms ≥20 Hz. We tested correlations between the surgical resection of those regions and post-surgical seizure outcome, and correlations between kurtosis and the rate/amplitude/duration of interictal paroxysms. RESULTS: The resection of the regions with high kurtosis correlated with 1-year post-surgical seizure outcome (p=0.028) but not with 2-year outcome. Kurtosis showed more significant correlation with 1-year seizure outcome than the SOZ and the rate/amplitude/duration of interictal paroxysms. Kurtosis showed positive, independent correlations with the amplitude and duration of interictal paroxysms (p<0.0001) but not with the rate (p=0.4). CONCLUSIONS: The regions with high kurtosis provide more reliable information to predict seizure outcome than the SOZ and the regions with high-rate/amplitude and long-duration interictal paroxysms. Kurtosis reflects combined effects of the amplitude and duration of the interictal paroxysms. SIGNIFICANCE: High kurtosis suggests the regions with acquired ictogenicity within the irritative zone.

Focal resection of fast ripples on extraoperative intracranial EEG improves seizure outcome in pediatric epilepsy.

PURPOSE: High-frequency oscillations (HFOs), termed ripples at 80-200 Hz and fast ripples (FRs) at >200/250 Hz, recorded by intracranial electroencephalography (EEG), may be a valuable surrogate marker for the localization of the epileptogenic zone. We evaluated the relationship of the resection of focal brain regions containing high-rate interictal HFOs and the seizure-onset zone (SOZ) determined by visual EEG analysis with the postsurgical seizure outcome, using extraoperative intracranial EEG monitoring in pediatric patients and automated HFO detection. METHODS: We retrospectively analyzed 28 pediatric epilepsy patients who underwent extraoperative intracranial video-EEG monitoring prior to focal resection. Utilizing the automated analysis, we identified interictal HFOs during 20 min of sleep EEG and determined the brain regions containing high-rate HFOs. We investigated spatial relationships between regions with high-rate HFOs and SOZs. We compared the size of these regions, the surgical resection, and the amount of the regions with high-rate HFOs/SOZs within the resection area with seizure outcome. KEY FINDINGS: Ten patients were completely seizure-free and 18 were not at 2 years after surgery. The brain regions with high-rate ripples were larger than those with high-rate FRs (p = 0.0011) with partial overlap. More complete resection of the regions with high-rate FRs significantly correlated with a better seizure outcome (p = 0.046). More complete resection of the regions with high-rate ripples tended to improve seizure outcome (p = 0.091); however, the resection of SOZ did not influence seizure outcome (p = 0.18). The size of surgical resection was not associated with seizure outcome (p = 0.22-0.39). SIGNIFICANCE: The interictal high-rate FRs are a possible surrogate marker of the epileptogenic zone. Interictal ripples are not as specific a marker of the epileptogenic zone as interictal FRs. Resection of the brain regions with high-rate interictal FRs in addition to the SOZ may achieve a better seizure outcome.

Connexin32 protects against vascular inflammation by modulating inflammatory cytokine expression by endothelial cells.

Gap junctions (GJs) play an important role in vascular function, stability, and homeostasis in endothelial cells (ECs), and GJs are comprised of members of the connexin (Cx) family. GJs of vascular ECs are assembled from Cx37, Cx40, and Cx43, and we showed that ECs also express Cx32. In this study, we investigated a potential role for Cx32 during vascular inflammation. Expression of Cx32 mRNA and protein by human umbilical venous ECs (HUVECs) decreased following treatment with tumor necrosis factor (TNF)-α, but lipopolysaccharide (LPS) and interleukin (IL)-1ß did not affect Cx32 expression. Intracellular transfer of an inhibitory anti-Cx32 monoclonal antibody significantly enhanced TNF-α-induced monocyte chemotactic protein (MCP)-1 and IL-6 expression, but overexpression of Cx32 abrogated TNF-α-induced MCP-1 and IL-6 expression. LPS treatment of Cx32 knock-out mice significantly increased the serum concentrations of TNF-α, interferon-γ, IL-6 and MCP-1, compared to wild-type littermate mice. These data suggest that Cx32 protects ECs from inflammation by regulating cytokine expression and plays an important role in the maintenance of vascular function.