Momentum-Dependent Hybridization Gap and dispersive in-gap state of The Kondo Semiconductor SmB6

We report the temperature-dependent three-dimensional angle-resolved photoemission spectra of the Kondo semiconductor SmB$_6$. We found a difference in the temperature dependence of the peaks at the X and $\Gamma$ points, due to hybridization between the Sm 5d conduction band and the nearly localized Sm 4f state. The peak intensity at the X point has the same temperature dependence as the valence transition below 120 K, while that at the $\Gamma$ point is consistent with the magnetic excitation at Q=(0.5,0.5,0.5) below 30 K. This suggests that the hybridization with the valence transition mainly occurs at the X point, and the initial state of the magnetic excitation is located at the $\Gamma$ point.Comment: 5 pages, 3 figure

Histological characteristics of incidentally-found growing meningiomas

Object. With the wider use of CT and MRI, many meningiomas are discovered as incidental findings during diagnostic work-up for unrelated symptoms. The majority shows no or minimal growth. The purpose of this study was to distinguish pathological features of incidentally-found growing meningiomas by comparing incidentally-found with symptomatic meningiomas. Methods. One hundred and thirty two consecutive nonrecurrent surgically-treated meningiomas treated between 2005 and 2007 were divided into three categories : 19 incidentally-found growing meningiomas (IG), 50 incidentallyfound meningiomas (I), and 63 symptomatic (S) meningiomas. The average follow-up period for the IG meningiomas was 3.7 years. Six out of 19 patients of the IG meningiomas became symptomatic during observation. Results. There is a significant difference of the incidence of WHO grades I, II, and III between all three groups (p=0.035). The incidence of WHO grades II and III in groups IG, I, and S were 26%, 2%, and 10%, respectively. We compare MIB-1 staining index between three groups : an average was 3.8% in IG, 1.3% in I, and 2.4% in S meningiomas. Conclusions. Incidentally-found meningiomas need careful follow-up. One fourth of the meningiomas that showed signs of growing belonged to the atypical or malignant grade

Subocclusive thrombus at the origin of LSA

Optimal treatment of patients with intracranial subocclusive thrombus remains unclear. Such a rare case successfully managed with endovascular mechanical thrombectomy is presented. A 71-year-old man experienced a sudden onset of dysarthria and motor deficits. At the time of admission his National Institutes of Health Stroke Scale (NIHSS) score was 4. DWI demonstrated incomplete infarction within the left lenticulostriate artery (LSA) territory, MRA showed partial flow defect in the distal left M1 segment and non-visualization of the LSA, and ECG revealed atrial fibrillation, thus ischemic stroke caused by cardiogenic embolism was diagnosed. Tissue plasminogen activator was administered, but symptoms progressed and NIHSS score increased up to 8. Diagnostic angiogrpahy confirmed presence of the subocclusive thrombus within the distal left M1 segment and complete occlusion of LSA at its origin. Since conservative therapy was ineffective, mechanical thrombectomy utilizing ADAPT (a direct aspiration first-pass thrombectomy) technique was performed resulting in compete recanalization of the LSA accompanied by the prompt regress of neurological symptoms. Eventally, the patient demonstrated nearly full recovery (modified Rankin Scale score 1). Thus, mechanical thrombectomy should be considered as a reasonable option in cases of acute cerebral stroke caused by subocclusive thrombus and progressive neurological deficits despite standard conservative therapy

Gene expression in a canine basilar artery vasospasm model: a genome-wide network-based analysis

To investigate the changes of gene expression on the cerebral vasospasm after subarachnoid hemorrhage, we used genome-wide microarray for a canine double-hemorrhage model and analyzed the data by using a network-based analysis. Six dogs were assigned to two groups of three animals: control and hemorrhage. The effects were assessed by the changes in gene expressions in the artery 7 days after the first blood injection. Among 23,914 genes, 447 and 66 genes were up-regulated more than two- and fivefold, respectively, and 332 and 25 genes were down-regulated more than two- and fivefold, respectively. According to gene ontology, genes related to cell communication (P = 5.28E-10), host–pathogen interaction (7.65E-8), and defense–immunity protein activity (0.000183) were significantly overrepresented. The top high-level function for the merged network derived from the network-based analysis was cell signaling, revealing that the subgroup that regulates the quantity of Ca2+ to have the strongest association significance (P = 4.75E-16). Canine microarray analysis followed by gene ontology profiling and connectivity analysis identified several functional groups and individual genes responding to cerebral vasospasm. Ca2+ regulation may play a key role in these gene expression changes and may be involved in the pathogenesis of cerebral vasospasm

Trigonal cavernous malformation with intraventricular hemorrhage : A case report and literature review

We reported a case of trigonal cavernous malformation (CM) with intraventricular hemorrhage. This 67-year-old woman experienced sudden onset of loss of consciousness and her Glasgow Coma Scale (GCS) was 5 points (E1V1M3) on admission. CT scan demonstrated intraventricular hemorrhage and acute hydrocephalus. Angiography did not demonstrate any vascular abnormality. Ventricular drainage was performed for acute hydrocephalus and the postoperative course was good. CT showed a hyperdense lesion in the left trigone, which was contrast-enhanced on T1-weighted MR. Removal of CM was performed via the left middle temporal sulcus. We conducted a Pub Med search for trigonal CM and found 17 cases. Herein we discuss the symptoms, CT and MR findings and treatment

Sensitivity of CT perfusion for the diagnosis of cerebral infarction

We aimed to determine the sensitivity of CT perfusion (CTP) for the diagnosis of cerebral infarction in the acute stage. We retrospectively reviewed patients with ischemic stroke who underwent brain CTP on arrival and MRI-diffusion weighted image (DWI) after hospitalization between October 2008 and October 2011. Final diagnosis was made from MRI-DWI findings and 87 patients were identified. Fifty-five out of 87 patients (63%) could be diagnosed with cerebral infarction by initial CTP. The sensitivity depends on the area size (s) : 29% for S<3 cm2, 83% for S≥3 cm2-<6 cm2, 88% for S≥6 cm2-<9 cm2, 80% for S≥9 cm2-<12 cm2, and 96% for S≥12 cm2 (p<0.001). Sensitivity depends on the type of infarction : 0% for lacunar, 74% for atherothrombotic, and 92% for cardioembolism (p<0.001). Sensitivity is not correlated with hours after onset. CT perfusion is an effective imaging modality for the diagnosis and treatment decisions for acute stroke, particularly more serious strokes

Clinical and radiological features related to the growth potential of meningioma

Clinical and radiological features that help predict the growth potential of meningioma would be beneficial. The purpose of this study is to clarify the characteristics related to proliferating potential using the MIB-1 staining index. We analyzed the relationship of MIB-1 staining indices to characteristics of 342 consecutive patients with meningioma surgically removed between 1995 and 2004 by logistic regression analysis. One hundred and forty-nine of the patients with meningioma were ≥60 in age; 89 male; 48 recurrent; 203 symptomatic; 157 at the skull base; 124 over 20 cm(3); 24 multiple; 136 with edema; 117 with calcification. The MIB-1 staining index in 56 of 296 grade I meningiomas in WHO classification was ≥ 3.0; in 27 of 28 grade II; and in 17 of 18 grade III, respectively. Logistic regression analysis demonstrated that male (odds ratio [OR], 2.374, p=0.003), recurrence (OR, 7.574, p=0.0001), skull base (OR, 0.540, p=0.035), calcification (OR, 0.498, p=0.019) were independent risk factors for a high MIB-1 staining index (≥3.0); age, symptomatic, volume, multiple, edema were not. Male, recurrence, non-skull base, absence of calcification are independent risk factors for a high proliferative potential. These should be taken into consideration when managing meningiomas