Treatment factors to suppress delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage based on VASOGRADE: multicenter cohort study.

Delayed cerebral ischemia (DCI) is one of the most important outcome determinants for aneurysmal subarachnoid hemorrhage (aSAH). VASOGRADE, which combines World Federation of Neurological Surgeons grade and modified Fisher grade, is a useful scale for predicting DCI after aSAH. However, no studies have investigated whether VASOGRADE influences the treatment options. We retrospectively analyzed 781 aSAH patients who were prospectively enrolled in 9 primary stroke centers from 2013 to 2021. The total cohort consisted of 76 patients (9.7%) with VASOGRADE-Green, 390 patients (49.9%) with VASOGRADE-Yellow, and 315 patients (40.3%) with VASOGRADE-Red. Worse VASOGRADE had higher incidences of DCI, which occurred in 190 patients (24.3%). As only 5 patients (6.6%) with VASOGRADE-Green developed DCI, we searched for DCI-associated factors in patients with VASOGRADEs-Yellow and -Red. Multivariate analyses revealed independent treatment factors suppressing DCI as follows: no postoperative hemorrhagic complication, combined administration of fasudil hydrochloride and cilostazol, combination of clipping and cisternal drainage, and coiling for VASOGRADE-Yellow; and clipping, and administration of fasudil hydrochloride with or without cilostazol for VASOGRADE-Red. The findings suggest that treatment strategies should be determined based on VASOGRADE to prevent DCI after aSAH.

Rapid detection of the MYD88 L265P mutation for pre- and intra-operative diagnosis of primary central nervous system lymphoma.

The myeloid differentiation primary response gene 88 (MYD88) L265P mutation is a disease-specific mutation of primary central nervous system lymphoma (PCNSL) among the central nervous system tumors. Accordingly, this mutation is considered a reliable diagnostic molecular marker of PCNSL. As the intra-operative diagnosis of PCNSL is sometimes difficult to achieve using histological examinations alone, intra-operative detection of the MYD88 L265P mutation could be effective for the accurate diagnosis of PCNSL. Herein, we aimed to develop a novel rapid genotyping system (GeneSoC) using real-time polymerase chain reaction (PCR) based on microfluidic thermal cycling technology. This real-time PCR system shortened the analysis time, which enabled the detection of the MYD88 L265P mutation within 15 min. Rapid detection of the MYD88 L265P mutation was performed intra-operatively using GeneSoC in 24 consecutive cases with suspected malignant brain tumors, including 10 cases with suspected PCNSL before surgery. The MYD88 L265P mutation was detected in eight cases in which tumors were pathologically diagnosed as PCNSL after the operation, while wild-type MYD88 was detected in 16 cases. Although two of the 16 cases with wild-type MYD88 were pathologically diagnosed as PCNSL after the operation, MYD88 L265P could be detected in all eight PCNSL cases harboring MYD88 L265P. The MYD88 L265P mutation could also be detected using cell-free DNA derived from the cerebrospinal fluid of two PCNSL cases. Detection of the MYD88 L265P mutation using GeneSoC might not only improve the accuracy of intra-operative diagnosis of PCNSL but also help the future pre-operative diagnosis through liquid biopsy of cerebrospinal fluid.

Cholesterol Crystals in Embolic Debris are Associated with Postoperative Cerebral Embolism after Carotid Artery Stenting.

OBJECT: We investigated possible associations among the presence of cholesterol crystals in embolic debris, the proportions of debris components, and postoperative cerebral embolism in patients undergoing carotid artery stenting (CAS). METHODS: Sixty-seven consecutive procedures were performed for internal carotid artery stenosis with CAS at our hospital between November 2015 and February 2018. Procedures for emergency CAS for stroke in evolution or crescendo transient ischemic attack were excluded (n = 12). The embolic debris from remaining procedures (n = 55) was stained with hematoxylin-eosin and the red blood cells, white blood cells, and fibrin were quantified by color-based segmentation. Cholesterol crystals and calcification were examined histopathologically. Diffusion-weighted imaging (DWI) was performed 1-3 days after CAS, and the images were used to classify procedures according to the presence of new lesions. RESULTS: Of the 55 CAS procedures, new DWI lesions were identified after 32. One patient had symptomatic cerebral embolism. Higher proportions of patients with cholesterol crystals in embolic debris (17 vs. 78%, p < 0.001) and higher proportion of white blood cells (mean 2.3 [0-9.9] vs. 4.2% [0-29.9%], p < 0.01) were observed in the embolic debris of procedures with and without new DWI lesions. CONCLUSIONS: Cholesterol crystals were common in the embolic debris from patients with postoperative ischemic lesions after CAS. These results suggest that inflammatory destabilization of the intraplaque lipid component is related to postprocedural DWI lesions.

The Safety of Carotid Artery Stenting for Patients in the Acute Poststroke Phase.

BACKGROUND: The efficacy of carotid artery stenting (CAS) for patients in the acute poststroke phase has not been established. We investigated the outcome of CAS for patients with symptomatic internal carotid artery (ICA) stenosis in the acute poststroke phase. METHODS: We performed a retrospective analysis of all patients who underwent CAS for symptomatic ICA stenosis in our institution. Patients in whom the time interval between neurological deterioration and the CAS procedure was less than 3 days were included in the early group, and the other patients were included in the delayed group. Perioperative complications including major adverse events (MAEs) were compared between the early and the delayed groups. RESULTS: One hundred five patients were included in the study. Forty patients were assigned to the early group and 65 patients were assigned to the delayed group. The overall MAE rate was 4.8%. There was no significant increase in the perioperative MAE in the early group compared with the delayed group (early group 2.5% versus delayed group 6.5%, P = .65). In the early group, 25 of 40 patients (62.5%) were functionally independent (modified Rankin scale [mRS] score of 0-2) at discharge. Significant differences between the independent patients and the disabled patients (mRS score of 3-6) included age (independent 72 versus disabled 79, P < .01) and prevalence of transient ischemic attack (36.0% versus .0%, P = .02). CONCLUSIONS: CAS performed within 3 days from the last ischemic event did not increase the risk of perioperative complication. Early CAS may be a useful option for the treatment of symptomatic carotid artery stenosis.

[Pontine Hemorrhage Suspected due to Dural Arteriovenous Fistula at the Craniocervical Junction:A Case Report].

Dural arteriovenous fistulas occurring at the craniocervical junction(CCJd-AVF)are uncommon; however, they demonstrate a wide range of clinical presentations. We describe the case of a patient with pontine hemorrhage suspected due to CCJd-AVF. A 68-year-old man presented to our hospital with a sudden onset of left hemiparesis. Cranial computed tomography(CT)revealed pontine and subarachnoid hemorrhage. Magnetic resonance imaging, as well as MR, CT, and left vertebral angiograms were performed and showed a CCJd-AVF in addition to a varix coincident with the hematoma cavities. The patient was successfully treated using surgical drainer clipping. A CCJd-AVF presenting concomitantly with a pontine hemorrhage is extremely rare. Careful assessment of the anatomical relationship between the skull base and the surrounding vascular structures is important to plan neurosurgical procedures for direct interruption of the draining vein. Three-dimensional CT angiography is a useful modality that facilitates visualization of complex and anomalous anatomical structures.

A Combination of Amide Proton Transfer, Tumor Blood Flow, and Apparent Diffusion Coefficient Histogram Analysis Is Useful for Differentiating Malignant from Benign Intracranial Tumors in Young Patients: A Preliminary Study.

PURPOSE: To evaluate the amide proton transfer (APT), tumor blood flow (TBF), and apparent diffusion coefficient (ADC) combined diagnostic value for differentiating intracranial malignant tumors (MTs) from benign tumors (BTs) in young patients, as defined by the 2021 World Health Organization classification of central nervous system tumors. METHODS: Fifteen patients with intracranial MTs and 10 patients with BTs aged 0-30 years underwent MRI with APT, pseudocontinuous arterial spin labeling (pCASL), and diffusion-weighted imaging. All tumors were evaluated through the use of histogram analysis and the Mann-Whitney U test to compare 10 parameters for each sequence between the groups. The diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: The APT maximum, mean, 10th, 25th, 50th, 75th, and 90th percentiles were significantly higher in MTs than in BTs; the TBF minimum (min) was significantly lower in MTs than in BTs; TBF kurtosis was significantly higher in MTs than in BTs; the ADC min, 10th, and 25th percentiles were significantly lower in MTs than in BTs (all p < 0.05). The APT 50th percentile (0.900), TBF min (0.813), and ADC min (0.900) had the highest area under the curve (AUC) values of the parameters in each sequence. The AUC for the combination of these three parameters was 0.933. CONCLUSIONS: The combination of APT, TBF, and ADC evaluated through histogram analysis may be useful for differentiating intracranial MTs from BTs in young patients.

Cilostazol May Improve Outcomes Even in Patients with Aneurysmal Subarachnoid Hemorrhage Aged 75 Years and Older: Multicenter Cohort Study and Propensity Score-Matched Analyses.

BACKGROUND: The opportunities to treat elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) are increasing globally, but the outcome remains poor. This study seeks to investigate treatment-related factors that can modify functional outcomes in patients with aSAH aged ≥75 years. METHODS: A total of 202 patients with aSAH aged ≥75 years prospectively enrolled in 9 primary stroke centers from 2013 to 2021 were retrospectively analyzed. Clinical variables including treatments for hydrocephalus, angiographic vasospasm, and delayed cerebral ischemia were compared between patients with good (modified Rankin Scale [mRS] score 0-2) and poor (mRS score 3-6) outcomes at 90 days from onset, followed by multivariate analyses to find independent outcome determinants. A modifiable treatment-related variable was evaluated after propensity score matching with adjustments for age, sex, pre-onset mRS score, aSAH severity, and treatment modality. RESULTS: More than half of patients showed World Federation of Neurological Societies grades IV-V on admission. Univariate analyses showed that advanced age, worse pre-onset mRS score, more severe neurologic status on admission, higher modified Fisher grade on admission computed tomography scans, and acute and chronic hydrocephalus were associated with poor outcomes. In contrast, administration of a phosphodiesterase type III inhibitor, cilostazol, was associated with good outcomes in both univariate (P = 0.036) and multivariate analyses (adjusted odds ratio, 0.305; 95% confidence interval, 0.097-0.955; P = 0.042). Propensity score matching analyses showed that patients treated with cilostazol had better outcomes (P = 0.016) with fewer incidences of delayed cerebral infarction (P = 0.008). CONCLUSIONS: Even in patients with aSAH aged ≥75 years, cilostazol administration may lead to better outcomes by suppressing the development of delayed cerebral infarction.

Effects of New-Generation Antiepileptic Drug Prophylaxis on Delayed Neurovascular Events After Aneurysmal Subarachnoid Hemorrhage.

Neuroelectric disruptions such as seizures and cortical spreading depolarization may contribute to the development of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH). However, effects of antiepileptic drug prophylaxis on outcomes remain controversial in SAH. The authors investigated if prophylactic administration of new-generation antiepileptic drugs levetiracetam and perampanel was beneficial against delayed neurovascular events after SAH. This was a retrospective single-center cohort study of 121 consecutive SAH patients including 56 patients of admission World Federation of Neurological Surgeons grades IV - V who underwent aneurysmal obliteration within 72 h post-SAH from 2013 to 2021. Prophylactic antiepileptic drugs differed depending on the study terms: none (2013 - 2015), levetiracetam for patients at high risks of seizures (2016 - 2019), and perampanel for all patients (2020 - 2021). The 3rd term had the lowest occurrence of delayed cerebral microinfarction on diffusion-weighted magnetic resonance imaging, which was related to less development of DCI. Other outcome measures were similar among the 3 terms including incidences of angiographic vasospasm, computed tomography-detectable delayed cerebral infarction, seizures, and 3-month good outcomes (modified Rankin Scale 0 - 2). The present study suggests that prophylactic administration of levetiracetam and perampanel was not associated with worse outcomes and that perampanel may have the potential to reduce DCI by preventing microcirculatory disturbances after SAH. Further studies are warranted to investigate anti-DCI effects of a selective α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonist perampanel in SAH patients in a large-scale prospective study.

Plasma SPARC Elevation in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage.

Matricellular proteins have been implicated in pathologies after subarachnoid hemorrhage (SAH). To find a new therapeutic molecular target, the present study aimed to clarify the relationships between serially measured plasma levels of a matricellular protein, secreted protein acidic and rich in cysteine (SPARC), and delayed cerebral ischemia (DCI) in 117 consecutive aneurysmal SAH patients with admission World Federation of Neurological Surgeons (WFNS) grades I-III. DCI developed in 25 patients with higher incidences of past history of hypertension and dyslipidemia, preoperative WFNS grade III, modified Fisher grade 4, spinal drainage, and angiographic vasospasm. Plasma SPARC levels were increased after SAH, and significantly higher in patients with than without DCI at days 7-9, and in patients with VASOGRADE-Yellow compared with VASOGRADE-Green at days 1-3 and 7-9. However, there were no relationships between plasma SPARC levels and angiographic vasospasm. Receiver-operating characteristic curves differentiating DCI from no DCI determined the cut-off value of plasma SPARC ≥ 82.1 ng/ml at days 7 - 9 (sensitivity, 0.800; specificity, 0.533; and area under the curve, 0.708), which was found to be an independent determinant of DCI development in multivariate analyses. This is the first study to show that SPARC is upregulated in peripheral blood after SAH, and that SPARC may be involved in the development of DCI without angiographic vasospasm in a clinical setting.

TUG1-mediated R-loop resolution at microsatellite loci as a prerequisite for cancer cell proliferation.

Oncogene-induced DNA replication stress (RS) and consequent pathogenic R-loop formation are known to impede S phase progression. Nonetheless, cancer cells continuously proliferate under such high-stressed conditions through incompletely understood mechanisms. Here, we report taurine upregulated gene 1 (TUG1) long noncoding RNA (lncRNA), which is highly expressed in many types of cancers, as an important regulator of intrinsic R-loop in cancer cells. Under RS conditions, TUG1 is rapidly upregulated via activation of the ATR-CHK1 signaling pathway, interacts with RPA and DHX9, and engages in resolving R-loops at certain loci, particularly at the CA repeat microsatellite loci. Depletion of TUG1 leads to overabundant R-loops and enhanced RS, leading to substantial inhibition of tumor growth. Our data reveal a role of TUG1 as molecule important for resolving R-loop accumulation in cancer cells and suggest targeting TUG1 as a potent therapeutic approach for cancer treatment.

Mutation detection of urinary cell-free DNA via catch-and-release isolation on nanowires for liquid biopsy.

Cell-free DNA (cfDNA) and extracellular vesicles (EVs) are molecular biomarkers in liquid biopsies that can be applied for cancer detection, which are known to carry information on the necessary conditions for oncogenesis and cancer cell-specific activities after oncogenesis, respectively. Analyses for both cfDNA and EVs from the same body fluid can provide insights into screening and identifying the molecular subtypes of cancer; however, a major bottleneck is the lack of efficient and standardized techniques for the isolation of cfDNA and EVs from clinical specimens. Here, we achieved catch-and-release isolation by hydrogen bond-mediated binding of cfDNA in urine to zinc oxide (ZnO) nanowires, which also capture EVs by surface charge, and subsequently we identified genetic mutations in urinary cfDNA. The binding strength of hydrogen bonds between single-crystal ZnO nanowires and DNA was found to be equal to or larger than that of conventional hydrophobic interactions, suggesting the possibility of isolating trace amounts of cfDNA. Our results demonstrated that nanowire-based cancer screening assay can screen cancer and can identify the molecular subtypes of cancer in urine from brain tumor patients through EV analysis and cfDNA mutation analysis. We anticipate our method to be a starting point for more sophisticated diagnostic models of cancer screening and identification.

CD79B Y196 mutation is a potent predictive marker for favorable response to R-MPV in primary central nervous system lymphoma.

BACKGROUND: Rituximab, high-dose methotrexate (HD-MTX), procarbazine and vincristine (R-MPV), has significantly prolonged the survival of patients with primary central nervous system lymphoma (PCNSL), but predictive factors for response to R-MPV have not yet been investigated. Herein, we investigated the correlation of MYD88 L265P and CD79B Y196 mutations, which are the most frequently found molecular alterations in PCNSL, with prognosis of patients with PCNSL treated with R-MPV. METHODS: We investigated the long-term clinical course and status of MYD88 and CD79B genes in 85 patients with PCNSL treated with R-MPV or HD-MTX treatment, and the correlation of these genetic mutations with prognosis. RESULTS: R-MPV achieved an excellent tumor control rate (61.6% and 69.9% of 5-year progression-free and overall survival rates, respectively). While MYD88 L265P mutation had no significant effect on survival, patients with CD79B Y196 mutations exhibited prolonged survival (p < 0.05). However, the association of CD79B Y196 mutation with a better prognosis was not observed in the HD-MTX cohort, which indicated that CD79B Y196 mutation was a predictive marker for a favorable response to R-MPV. Furthermore, we established an all-in-one rapid genotyping system for these genetic mutations. CONCLUSIONS: In conclusion, CD79B Y196 mutation is a potent predictive marker for favorable response to R-MPV in PCNSL. The rapid identification of MYD88 L265P and CD79B Y196 mutations can be helpful not only for the accurate molecular diagnosis of PCNSL but also for the prediction of response to R-MPV.

Reliability of IDH1-R132H and ATRX and/or p53 immunohistochemistry for molecular subclassification of Grade 2/3 gliomas.

Since the World Health Organization 2016 classification (2016 WHO), genetic status has been incorporated into the diagnosis of Grade 2/3 gliomas (lower-grade gliomas). Therefore, immunohistochemistry (IHC) of IDH1-R132H, ATRX, and p53 have been used in place of genetic status. We report the associations between histological findings, IHC, and genetic status. We performed IHC of IDH1-R132H, ATRX, and p53 in 76 lower-grade gliomas and discussed its validity based on the 2016 WHO and the upcoming 2021 WHO classification. The sensitivity and specificity of anti-ATRX, p53, and IDH1-R132H IHC were 40.9%/98.1%, 78.6%/85.4%, and 90.5%/84.6%, respectively. Among 21 IDH1-mutant gliomas without 1p/19q codeletion, two gliomas (9.5%) mimicked the so-called classic for oligodendroglioma (CFO) in their morphology. Of the 42 gliomas with 1p/19q codeletion, four cases were difficult to diagnose as oligodendroglioma through morphological examination. Moreover, there were three confusing cases with ATRX mutations but with retained ATRX-IHC positivity. The lessons learned from this study are as follows: (1) ATRX-IHC and p53-IHC should be supplementary to morphological diagnosis, (2) rare IDH mutations other than IDH1 R132H should be considered, and (3) there is no complete alternative test to detect molecular features of glioblastoma under the 2021 WHO classification.

Driver Genetic Mutations in Spinal Cord Gliomas Direct the Degree of Functional Impairment in Tumor-Associated Spinal Cord Injury.

Genetic analysis in glioma has been developed recently. Spinal cord glioma is less common than intracranial glioma. Thus, the clinical significance of genetic mutations in spinal cord gliomas remains unclear. Furthermore, because the spinal cord is an important communication channel between the brain and the rest of the body, increased attention should be paid to its functional prognosis. In this study, we investigated the functional prognosis and driver genetic mutations in eight patients with spinal cord gliomas (World Health Organization grade I, three cases; grade II, two cases; grade III/IV, three cases). IDH mutations were detected in all grade II cases and H3F3A mutations were detected in all grade III/IV cases. The functional status of grade I and II gliomas remained unchanged or improved 1 year after surgery, whereas grade III/IV gliomas remained unchanged or deteriorated. Spinal glioma progenitor cells with H3F3A mutations were associated with accelerated tumor-associated spinal cord injury, which led to functional impairment. Conversely, the presence of IDH mutations, which are rarely reported in spinal gliomas, indicated a relatively favorable functional prognosis.

Annealed ZnO/Al2O3 Core-Shell Nanowire as a Platform to Capture RNA in Blood Plasma.

RNA analytical platforms gained extensive attention recently for RNA-based molecular analysis. However, the major challenge for analyzing RNAs is their low concentration in blood plasma samples, hindering the use of RNAs for diagnostics. Platforms that can enrich RNAs are essential to enhance molecular detection. Here, we developed the annealed ZnO/Al2O3 core-shell nanowire device as a platform to capture RNAs. We showed that the annealed ZnO/Al2O3 core-shell nanowire could capture RNAs with high efficiency compared to that of other circulating nucleic acids, including genomic DNA (gDNA) and cell-free DNA (cfDNA). Moreover, the nanowire was considered to be biocompatible with blood plasma samples due to the crystalline structure of the Al2O3 shell which serves as a protective layer to prevent nanowire degradation. Our developed device has the potential to be a platform for RNA-based extraction and detection.

Urinary MicroRNA-Based Diagnostic Model for Central Nervous System Tumors Using Nanowire Scaffolds.

There are no accurate mass screening methods for early detection of central nervous system (CNS) tumors. Recently, liquid biopsy has received a lot of attention for less-invasive cancer screening. Unlike other cancers, CNS tumors require efforts to find biomarkers due to the blood-brain barrier, which restricts molecular exchange between the parenchyma and blood. Additionally, because a satisfactory way to collect urinary biomarkers is lacking, urine-based liquid biopsy has not been fully investigated despite the fact that it has some advantages compared to blood or cerebrospinal fluid-based biopsy. Here, we have developed a mass-producible and sterilizable nanowire-based device that can extract urinary microRNAs efficiently. Urinary microRNAs from patients with CNS tumors (n = 119) and noncancer individuals (n = 100) were analyzed using a microarray to yield comprehensive microRNA expression profiles. To clarify the origin of urinary microRNAs of patients with CNS tumors, glioblastoma organoids were generated. Glioblastoma organoid-derived differentially expressed microRNAs (DEMs) included 73.4% of the DEMs in urine of patients with parental tumors but included only 3.9% of those in urine of noncancer individuals, which suggested that many CNS tumor-derived microRNAs could be identified in urine directly. We constructed the diagnostic model based on the expression of the selected microRNAs and found that it was able to differentiate patients and noncancer individuals at a sensitivity and specificity of 100 and 97%, respectively, in an independent dataset. Our findings demonstrate that urinary microRNAs extracted with the nanowire device offer a well-fitted strategy for mass screening of CNS tumors.

Newly established patient-derived organoid model of intracranial meningioma.

BACKGROUND: Recent comprehensive studies have revealed several molecular alterations that are frequently found in meningiomas. However, effective treatment reagents targeting specific molecular alterations have not yet been identified because of the limited number of representative research models of meningiomas. METHODS: We performed organoid cultures using meningioma cells and meningioma tumor tissues. Using immunohistochemistry and molecular analyses consisting of whole-exome sequencing, RNA-seq, and DNA methylation analyses, we compared the histological findings and molecular profiling of organoid models with those of parental tumors. Further, using these organoid models together with a public database of meningiomas, we explored molecular alterations, which are a potent treatment target for meningioma. RESULTS: We established 18 organoid models comprising of two malignant meningioma cells (HKBMM and IOMM-Lee), 10 benign meningiomas, four malignant meningiomas, and two solitary fibrous tumors (SFTs). The organoids exhibited consistent histological features and molecular profiles with those of the parental tumors. Using a public database, we identified that upregulated forkhead box M1 (FOXM1) was correlated with increased tumor proliferation. Overexpression of FOXM1 in benign meningioma organoids increased organoid proliferation; depletion of FOXM1 in malignant organoids decreased proliferation. Additionally, thiostrepton, a FOXM1 inhibitor combined with radiation therapy, significantly inhibited the proliferation of malignant meningioma organoid models. CONCLUSIONS: An organoid model for meningioma enabled us to elucidate the tumor biology of meningioma along with potent treatment targets for meningioma.

Mathematical Modeling and Mutational Analysis Reveal Optimal Therapy to Prevent Malignant Transformation in Grade II IDH-Mutant Gliomas.

Isocitrate dehydrogenase-mutant low-grade gliomas (IDHmut-LGG) grow slowly but frequently undergo malignant transformation, which eventually leads to premature death. Chemotherapy and radiotherapy treatments prolong survival, but can also induce genetic (or epigenetic) alterations involved in transformation. Here, we developed a mathematical model of tumor progression based on serial tumor volume data and treatment history of 276 IDHmut-LGGs classified by chromosome 1p/19q codeletion (IDHmut/1p19qcodel and IDHmut/1p19qnoncodel) and performed genome-wide mutational analyses, including targeted sequencing and longitudinal whole-exome sequencing data. These analyses showed that tumor mutational burden correlated positively with malignant transformation rate, and chemotherapy and radiotherapy significantly suppressed tumor growth but increased malignant transformation rate per cell by 1.8 to 2.8 times compared with before treatment. This model revealed that prompt adjuvant chemoradiotherapy prolonged malignant transformation-free survival in small IDHmut-LGGs (≤ 50 cm3). Furthermore, optimal treatment differed according to genetic alterations for large IDHmut-LGGs (> 50 cm3); adjuvant therapies delayed malignant transformation in IDHmut/1p19qnoncodel but often accelerated it in IDHmut/1p19qcodel. Notably, PI3K mutation was not associated with malignant transformation but increased net postoperative proliferation rate and decreased malignant transformation-free survival, prompting the need for adjuvant therapy in IDHmut/1p19qcodel. Overall, this model uncovered therapeutic strategies that could prevent malignant transformation and, consequently, improve overall survival in patients with IDHmut-LGGs. SIGNIFICANCE: A mathematical model successfully estimates malignant transformation-free survival and reveals a link between genetic alterations and progression, identifying precision medicine approaches for optimal treatment of IDH-mutant low-grade gliomas.

H3F3A mutant allele specific imbalance in an aggressive subtype of diffuse midline glioma, H3 K27M-mutant.

Diffuse midline glioma, H3 K27M-mutant is a lethal brain tumor located in the thalamus, brain stem, or spinal cord. H3 K27M encoded by the mutation of a histone H3 gene such as H3F3A plays a pivotal role in the tumorigenesis of this type of glioma. Although several studies have revealed comprehensive genetic and epigenetic profiling, the prognostic factors of these tumors have not been identified to date. In various cancers, oncogenic driver genes have been found to exhibit characteristic copy number alterations termed mutant allele specific imbalance (MASI). Here, we showed that several diffuse midline glioma, H3 K27M-mutant exhibited high variant allele frequency (VAF) of the mutated H3F3A gene using droplet digital polymerase chain reaction (ddPCR) assays. Whole-genome sequencing (WGS) revealed that these cases had various copy number alterations that affected the mutant and/or wild-type alleles of the H3F3A gene. We also found that these MASI cases showed a significantly higher Ki-67 index and poorer survival compared with those in the lower VAF cases (P < 0.05). Our results indicated that the MASI of the H3F3A K27M mutation was associated with the aggressive phenotype of the diffuse midline glioma, H3 K27M-mutant via upregulation of the H3 K27M mutant protein, resulting in downregulation of H3K27me3 modification.

Erythrocyte-Rich Thrombus Is Associated with Reduced Number of Maneuvers and Procedure Time in Patients with Acute Ischemic Stroke Undergoing Mechanical Thrombectomy.

BACKGROUND: Only few studies have investigated the relationship between the histopathology of retrieved thrombi and clinical outcomes. This study aimed to evaluate thrombus composition and its association with clinical, laboratory, and neurointerventional findings in patients treated by mechanical thrombectomy due to acute large vessel occlusion. METHODS: At our institution, 79 patients were treated by mechanical thrombectomy using a stent retriever and/or aspiration catheter between August 2015 and August 2016. The retrieved thrombi were quantitatively analyzed to quantify red blood cells, white blood cells, and fibrin by area. We divided the patients into two groups - a fibrin-rich group and an erythrocyte-rich group - based on the predominant composition in the thrombus. The groups were compared for imaging, clinical, and neurointerventional data. RESULTS: The retrieved thrombi from 43 patients with acute stroke from internal carotid artery, middle cerebral artery, or basilar artery occlusion were histologically analyzed. Erythrocyte-rich thrombi were present in 18 cases, while fibrin-rich thrombi were present in 25 cases. A cardioembolic etiology was significantly more prevalent among the patients with fibrin-rich thrombi than among those with erythrocyte-rich thrombi. Attenuation of thrombus density as shown on computed tomography images was greater in patients with erythrocyte-rich thrombi than in those with fibrin-rich thrombi. All other clinical and laboratory characteristics remained the same. Patients with erythrocyte-rich thrombi had a smaller number of recanalization maneuvers, shorter procedure times, a shorter time interval between arrival and recanalization, and a higher percentage of stent retrievers in the final recanalization procedure. The occluded vessels did not differ significantly. CONCLUSIONS: In this study, erythrocyte-rich thrombus was associated with noncardioembolic etiology, higher thrombus density, and reduced procedure time.