廣瀬 雄一

The ventricular-subventricular zone (V-SVZ) is the largest neurogenic niche in the postnatal mammalian brain, but its organization and migratory dynamics remain poorly understood in gyrencephalic species. Here, we provide ultrastructural and three-dimensional characterization of the V-SVZ neuroblasts in postnatal microminipigs, the smallest pig strain with unique advantages for experimental neuroscience. Transmission electron microscopy revealed developmental changes in cell composition and cytoarchitecture, with migratory neuroblasts consistently associated with glial cells and vasculatures. Notably, serial block-face scanning electron microscopy revealed that tier 3 neuroblasts, a gyrencephalic-specific population, formed elongated, chain-like clusters aligned along vessels, with conserved intracellular features such as polarized organelle distributions and growth cone extension. Radial glial fibers were prominent in neonates but diminished with age, suggesting a developmental shift to vascular scaffolds as primary migration guides. These findings establish microminipigs as a tractable gyrencephalic model for studying postnatal neurogenesis, offering new opportunities for translational research on brain repair.

PURPOSE: Digital subtraction angiography (DSA) is the gold standard for follow-up evaluation of intracranial aneurysms treated with the Woven EndoBridge (WEB) device. This study aimed to assess the efficacy of high-resolution CT angiography (HR-CTA) as a less invasive alternative by comparing its diagnostic performance with that of DSA. METHODS: This single-center retrospective study analyzed the angiographic and clinical data of patients treated with the WEB device for cerebral aneurysms between January 2021 and December 2024. Patients who underwent HR-CTA within 2 weeks before or after follow-up DSA were included. Occlusion status was assessed using the Bicêtre Occlusion Scale Score (BOSS) and binary classification. The concordance rate between HR-CTA and DSA was evaluated. RESULTS: A total of 54 eligible examinations were identified. Using the BOSS, 46 examinations were concordant, resulting in an agreement rate of 85.2%. The Cohen's κ coefficient was 0.81 (95% CI 0.69 to 0.93), indicating a very high level of agreement. All discordant cases resulted from HR-CTA overestimating occlusion status; however, HR-CTA accurately identified aneurysm remnants. Univariate analyses identified BOSS 0' as the only significant factor contributing to discrepancies. In the binary evaluation, all 54 examinations were fully concordant (κ=1.00, 95% CI 1.00 to 1.00). CONCLUSIONS: HR-CTA demonstrated a high concordance rate with DSA for evaluating occlusion status after WEB placement. Its reliable assessment of aneurysm remnants suggests HR-CTA could serve as a practical and less invasive alternative to DSA in follow-up evaluations.

BRAF p.V600E-mutant gliomas and glioneuronal tumors comprise a wide clinicopathological spectrum, yet the relationship between genomic alteration burden and histological grade remains incompletely defined. We analyzed 15 BRAF p.V600E-mutant gliomas and glioneuronal tumors across histological grades using the PleSSision Rapid sequencing platform. Single-nucleotide variants (SNVs) and copy-number alterations were assessed in parallel to characterize genomic alteration profiles. Low-grade tumors generally exhibited limited genomic alterations; however, a subset of low-grade tumors showed increased numbers of SNVs. High-grade tumors demonstrated more extensive genomic alterations, characterized predominantly by copy-number gains. A trend toward increased copy-number gains with higher WHO grade was observed. Homozygous deletion of CDKN2A was observed in pleomorphic xanthoastrocytoma, including both CNS WHO grade 2 and grade 3 tumors, and epithelioid glioblastoma. These findings indicate substantial genomic heterogeneity among BRAF p.V600E-mutant gliomas and glioneuronal tumors. While low-grade tumors are generally genomically quiet, a subset shows increased alterations, and high-grade tumors tend to acquire copy-number changes, highlighting the limitations of genomic event counts alone as a surrogate for malignant potential.