Characterization of carotid plaques using chemical exchange saturation transfer imaging.

PURPOSE: The preoperative assessment of carotid plaques is necessary to render revascularization safe and effective. The aim of this study is to evaluate the usefulness of chemical exchange saturation transfer (CEST)-MRI, particularly amide proton transfer (APT) imaging as a preoperative carotid plaque diagnostic tool. METHODS: We recorded the APT signal intensity on concentration maps of 34 patients scheduled for carotid endarterectomy. Plaques were categorized into group A (APT signal intensity ≥ 1.90 E-04; n = 12) and group B (APT signal intensity < 1.90 E-04; n = 22). Excised plaques were subjected to histopathological assessment and, using the classification promulgated by the American Heart Association, they were classified as intraplaque hemorrhage-positive [type VI-positive (tVI+)] and -negative [no intraplaque hemorrhage (tVI-)]. RESULTS: Of the 34 patients, 22 (64.7%) harbored tVI+- and 12 (35.3%) had tVI- plaques. The median APT signals were significantly higher in tVI+- than tIVI- patients (2.43 E-04 (IQR = 0.98-4.00 E-04) vs 0.54 E-04 (IQR = 0.14-1.09 E-04), p < .001). Histopathologically, the number of patients with tVI+ plaques was significantly greater in group A (100%, n = 12) than group B (45%, n = 22) (p < .01). The number of symptomatic patients or asymptomatic patients with worsening stenosis was also significantly greater in group A than group B (75% vs 36%, p < .01). CONCLUSION: In unstable plaques with intraplaque hemorrhage and in patients with symptoms or progressive stenosis, the ATP signals were significantly elevated. CEST-MRI studies has the potential for the preoperative assessment of the plaques' characteristics.

An imbalance between RAGE/MR/HMGB1 and ATP1α3 is associated with inflammatory changes in rat brain harboring cerebral aneurysms prone to rupture.

BACKGROUND AND PURPOSE: An aneurysmal subarachnoid hemorrhage is a devastating event. To establish an effective therapeutic strategy, its pathogenesis must be clarified, particularly the pathophysiology of brain harboring intracranial aneurysms (IAs). To elucidate the pathology in brain harboring IAs, we examined the significance of the receptor for advanced glycation end-products (RAGE)/mineralocorticoid receptor (MR) pathway and Na+/K+-ATPase (ATP1α3). METHODS: Ten-week-old female rats were subjected to oophorectomy as well as hypertension and hemodynamic changes to induce IAs, and were fed a high-salt diet. Brain damage in these rats was assessed by inflammatory changes in comparison to sham-operated rats fed a standard diet. RESULTS: Six weeks after IA induction (n = 30), irregular morphological changes, i.e., an enlarged vessel diameter and vascular wall, were observed in all of the left posterior cerebral arteries (Lt PCAs) prone to rupture. Approximately 20% of rats had ruptured IAs within 6 weeks. In brain harboring unruptured IAs at the PCA, the mRNA levels of RAGE and MR were higher, and that of ATP1α3 was lower than those in the sham-operated rats (p < 0.05, each). Immunohistochemically, elevated expression of RAGE and MR, and decreased expression of ATP1α3 were observed in the brain parenchyma adjacent to the Lt PCA, resulting in increased Iba-1 and S100B expression that reflected the inflammatory changes. There was no difference between the unruptured and ruptured aneurysm rat groups. Treatment with the MR antagonist esaxerenone abrogated these changes, and led to cerebral and vascular normalization and prolonged subarachnoid hemorrhage-free survival (p < 0.05). CONCLUSIONS: Regulation of the imbalance between the RAGE/MR pathway and ATP1α3 may help attenuate the damage in brain harboring IAs, and further studies are warranted to clarify the significance of the down-regulation of the MR/RAGE pathway and the up-regulation of ATP1α3 for attenuating the pathological changes in brain harboring IAs.

STING, a cytosolic DNA sensor, plays a critical role in atherogenesis: a link between innate immunity and chronic inflammation caused by lifestyle-related diseases.

AIMS: Lifestyle-related diseases promote atherosclerosis, a chronic inflammatory disease; however, the molecular mechanism remains largely unknown. Endogenous DNA fragments released under over-nutrient condition provoke sterile inflammation through the recognition by DNA sensors. Here, we investigated the role of stimulator of interferon genes (STING), a cytosolic DNA sensor, in atherogenesis. METHODS AND RESULTS: Apolipoprotein E-deficient (Apoe-/-) mice fed a western-type diet (WTD), a hypercholesterolaemic mouse model, showed higher STING expression and markers for DNA damage such as γH2AX, p53, and single-stranded DNA (ssDNA) accumulation in macrophages in the aorta compared with wild-type (WT) mice. The level of cGAMP, a STING agonist, in the aorta was higher in Apoe-/- mice. Genetic deletion of Sting in Apoe-/- mice reduced atherosclerotic lesions in the aortic arch, lipid, and macrophage accumulation in plaques, and inflammatory molecule expression in the aorta compared with the control. Pharmacological blockade of STING using a specific inhibitor, C-176, ameliorated atherogenesis in Apoe-/- mice. In contrast, bone marrow-specific STING expression in Apoe-/- mice stimulated atherogenesis. Expression or deletion of STING did not affect metabolic parameters and blood pressure. In vitro studies revealed that STING activation by cGAMP or mitochondrial DNA accelerated inflammatory molecule expression (e.g. TNF-α or IFN-ß) in mouse and human macrophages. Activation of nuclear factor-κB and TANK binding kinase 1 was involved in STING-associated vascular inflammation and macrophage activation. Furthermore, human atherosclerotic lesions in the carotid arteries expressed STING and cGAMP. CONCLUSION: Stimulator of interferon genes stimulates pro-inflammatory activation of macrophages, leading to the development of atherosclerosis. Stimulator of interferon genes signalling may serve as a potential therapeutic target for atherosclerosis.

Elevated Urinary Titin and its Associated Clinical Outcomes after Acute Stroke.

INTRODUCTION: Urinary titin is a biomarker of muscle atrophy, which is a serious complication after stroke. However, there are currently no clinical data regarding urinary titin in stroke patients. METHODS: Consecutive stroke patients admitted to the stroke care unit were included. Spot urine samples were collected immediately after admission, and on days 3, 5, and 7. The primary outcome was the trend of urinary titin in patients after acute stroke. The secondary outcomes included the association between the peak urinary titin level and the modified Rankin Scale (mRS) score, the National Institutes of Health Stroke Scale (NIHSS) score, and the Barthel index (BI) upon hospital discharge. Multivariate analysis was adjusted for age, sex, NIHSS at admission, and the peak urinary titin to predict poor outcome (mRS 3-6). RESULTS: Forty-one patients were included (29 male; age, 68 ± 15 years), 29 had ischemic stroke, 8 had intracerebral hemorrhage, and 4 had subarachnoid hemorrhage. The levels of urinary titin on days 1, 3, 5, and 7 were 9.9 (4.7-21.1), 16.2 (8.6-22.0), 8.9 (4.8-15.2), and 8.7 (3.6-16.2) pmol/mg Cr, respectively. The peak urinary titin level was associated with the mRS score (r = 0.55, p < 0.01), the NIHSS score (r = 0.72, p < 0.01), and the BI (r = -0.59, p < 0.01) upon hospital discharge. In multivariate analysis, the peak urinary titin was associated with poor outcome (p = 0.03). CONCLUSIONS: Urinary titin rapidly increased after stroke and was associated with impaired functional outcomes at hospital discharge.

The Claw Sign: An angiographic Predictor of Recanalization After Mechanical Thrombectomy for Cerebral Large Vessel Occlusion.

BACKGROUND: Mechanical thrombectomy undoubtedly improves functional outcomes for patients with acute ischemic stroke. Although we have observed occlusion sites that protrude proximally into the vessel on angiography, termed the "claw sign," we have been unable to state its clinical significance. In this study, we aimed to determine whether the presence of a claw sign was related to recanalization success after mechanical thrombectomy. MATERIALS AND METHODS: We retrospectively included 73 consecutive patients treated for acute cerebral large vessel occlusion by mechanical thrombectomy between January 2014 and December 2017. The angiographic claw sign was defined as a thrombus that protruded proximally by more than half the diameter of the parent artery. Claw sign positivity, clinical and etiological features, and outcomes were compared between groups with and without recanalization. RESULTS: The claw sign was observed in 29 of 73 (40%) patients and was positive significantly more frequently in those with recanalization (50.0%) than in those without recanalization (5.9%) (P < .01). By multivariate analysis, the claw sign was the only pretreatment parameter to predict successful recanalization (odds ratio, 12.50; 95% confidence interval, 1.50-103.00; P = .019). CONCLUSIONS: The presence of the claw sign might predict successful recanalization in patients undergoing mechanical thrombectomy for large vessel occlusion.

Treatment of Unruptured Cerebral Aneurysms with the Mineralocorticoid Receptor Blocker Eplerenone-Pilot Study.

BACKGROUND: Currently there are no pharmacological therapies for patients with unruptured cerebral aneurysms. Elsewhere we showed that the mineralocorticoid receptor antagonist eplerenone prevented the formation of cerebral aneurysms in our ovariectomized hypertensive aneurysm rat model. The current pilot study evaluated whether it can be used to prevent the growth and rupture of cerebral aneurysms in hypertensive patients. METHODS: Between August 2011 and May 2014, we enrolled 82 patients with 90 aneurysms in an open-label uncontrolled clinical trial. All provided prior informed consent for inclusion in this study, and all were treated with eplerenone (25-100 mg/d). The primary end points of our study were the rupture and enlargement of the cerebral aneurysms. RESULTS: Of the 82 patients, 80 (88 unruptured aneurysms) were followed for a mean of 21.3 months (153.4 aneurysm-years); 12 patients (15.0%) permanently discontinued taking the drug. One month after the start of eplerenone administration and throughout the follow-up period, eplerenone kept the blood pressure within the normal range. Most notably, no aneurysms smaller than 9 mm ruptured or enlarged. However, of 2 large thrombosed aneurysms, 1 enlarged and the other ruptured. The overall annual rupture rate was .65%; it was 13.16% for aneurysms larger than 10 mm; the overall annual rate for reaching the primary end points was 1.30%. CONCLUSION: Our observations suggest that eplerenone may help to prevent the growth and rupture of unruptured cerebral aneurysms smaller than 9 mm. To assess its potential long-term clinical benefits, large clinical trials are needed.

Optimal Timing of Diffusion-Weighted Imaging to Avoid False-Negative Findings in Patients With Transient Ischemic Attack.

BACKGROUND AND PURPOSE: We aimed to investigate the optimal timing of diffusion-weighted imaging (DWI) in patients with transient ischemic attack (TIA). METHODS: Seventy-three consecutive patients with TIA underwent DWI on admission (initial DWI) and at 24 hours after admission (second DWI). Patients were divided into 2 groups based on initial DWI findings in relation to the second examination: false negative (group 1) and other (group 2). The probability of initial false-negative findings was determined for each hour from TIA onset to initial DWI. Multivariate analysis was used to evaluate the independent risk factors associated with false-negative findings on initial DWI. RESULTS: Of the 73 patients examined (56 men; mean age, 68 years), 9 (12%) were categorized into group 1. The latency from TIA onset to initial DWI was 1.7±0.6 hours for group 1 (range, 1-2.8 hours) and 3.3±2.6 hours for group 2 (range, 35 minutes to 12 hours). The probability of false-negative findings on initial DWI decreased in a time-dependent manner (25%, 21%, and 7% for 1, 2, and 3 hours, respectively), and no false-negative findings were observed on initial DWI performed at >3 hours from symptom onset. Short latency (≤2 hours) from TIA onset to initial DWI was an independent risk factor related to false-negative findings (odds ratio, 13.11; 95% confidence interval, 1.07-161.38; P=0.045). CONCLUSIONS: If the duration between TIA symptom onset and initial DWI is <2 hours, a repeat examination should be performed to minimize the risk of false-positive findings.

Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment.

PURPOSE: Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. METHODS: Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). RESULTS: Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. CONCLUSION: High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site.

Risk Factors of Neurological Deterioration in Patients with Cerebral Infarction due to Large-Artery Atherosclerosis.

BACKGROUND: In some patients with acute ischemic stroke, neurological deterioration (ND) is observed, and it is difficult to predict at the time of admission. Especially in some patients with large-artery atherosclerosis (LAA), aggressive medical treatments and surgical interventions might be helpful to prevent ND. Therefore, we investigated factors associated with ND in patients with LAA. METHODS: We studied patients with LAA who were admitted to our hospital. We divided them into 2 groups with (group 1) and without deterioration (group 2), and evaluated their medical records, risk factors, and radiological findings, such as number of diffusion-positive lesion and degree of stenosis. RESULTS: Our study population consisted of 171 patients; 71 (41.5%) did and 100 (58.5%) did not suffer deterioration. By univariate analysis, blood pressure (BP), heart rate, National Institutes of Health Stroke Scale (NIHSS) score, number of diffusion-positive lesion, count of red blood cell, high-density lipoprotein, and degree of stenosis differed significantly between the 2 groups. By multivariate analysis, systolic BP (≥170 mm Hg, odds ratio: 7.20, P <.001) was associated with ND. Furthermore, number of diffusion-weighted image (DWI)-positive lesion (≥8), degree of stenosis (>80.0%), and NIHSS score (≥4) were also independent factors associated with ND. CONCLUSIONS: High BP, severity of neurological deficit at the time of admission, and radiological findings, such as degree of stenosis and number of DWI-positive lesion, are independently associated with ND in patients with LAA.

Hyperhomocysteinemia induced by excessive methionine intake promotes rupture of cerebral aneurysms in ovariectomized rats.

BACKGROUND: Hyperhomocysteinemia (HHcy) is associated with inflammation and a rise in the expression of matrix metalloproteinase-9 (MMP-9) in the vascular wall. However, the role of HHcy in the growth and rupture of cerebral aneurysms remains unclear. METHODS: Thirteen-week-old female Sprague-Dawley rats were subject to bilateral ovariectomy and ligation of the right common carotid artery and fed an 8 % high-salt diet to induce cerebral aneurysms. Two weeks later, they underwent ligation of the bilateral posterior renal arteries. They were divided into two groups and methionine (MET) was or was not added to their drinking water. In another set of experiments, the role of folic acid (FA) against cerebral aneurysms was assessed. RESULTS: During a 12-week observation period, subarachnoid hemorrhage due to aneurysm rupture was observed at the anterior communicating artery (AcomA) or the posterior half of the circle of Willis. HHcy induced by excessive MET intake significantly increased the incidence of ruptured aneurysms at 6-8 weeks. At the AcomA of rats treated with MET, we observed the promotion of aneurysmal growth and infiltration by M1 macrophages. Furthermore, the mRNA level of MMP-9, the ratio of MMP-9 to the tissue inhibitor of metalloproteinase-2, and the level of interleukin-6 were higher in these rats. Treatment with FA abolished the effect of MET, suggesting that the inflammatory response and vascular degradation at the AcomA is attributable to HHcy due to excessive MET intake. CONCLUSIONS: We first demonstrate that in hypertensive ovariectomized rats, HHcy induced by excessive MET intake may be associated with the propensity of the aneurysm wall to rupture.

Improvement of Plasma Biomarkers after Switching Stroke Patients from Other Angiotensin II Type I Receptor Blockers to Olmesartan.

BACKGROUND: Managing hypertension is crucial for preventing stroke recurrence. Some stroke patients experience resistant hypertension. In our experimental stroke model, olmesartan increased the expression of angiotensin (Ang) II converting enzyme-2. We hypothesized that switching to olmesartan affects biomarkers and the blood pressure (BP) in stroke patients whose BP is insufficiently controlled by standard doses of Ang II type I receptor blockers (ARBs) other than olmesartan. METHODS: We recruited 25 patients to study our hypothesis. All had a history of stroke or silent cerebral infarction. We switched them to olmesartan (10-40 mg per day) for 12 weeks and determined their plasma level of Ang-(1-7), peroxiredoxin, oxidized low-density lipoprotein (oxLDL)/ß-2-glycoprotein I (ß2GPI) complex, adiponectin, high mobility group box 1 (HMGB1), and tumor necrosis factor-α (TNFα) and recorded their BP before and after olmesartan treatment. RESULTS: After switching the patients to olmesartan, their plasma level of Ang-(1-7) as a vasoprotective indicator and adiponectin regulating metabolic syndrome was increased, and peroxiredoxin and the oxLDL/ß2GPI complex indicating its antioxidative stress and its proatherogenicity were lower than their baseline. This suggests that olmesartan may be more effective than other ARBs to improve these conditions. Neither HMGB1 nor TNFα reflecting an inflammatory response was affected, suggesting that the anti-inflammatory effects of olmesartan are similar to those of other ARBs. The recommended BP (<140/90) was obtained in 10 of the 25 patients after switching to olmesartan. No adverse events occurred. CONCLUSIONS: Switching from other ARBs to olmesartan may be a promising therapeutic option in patients with resistant hypertension.

Coexistence of anterior choroidal artery and posterior cerebral artery retia mirabilia presenting with subarachnoid hemorrhage: illustrative case.

BACKGROUND: A rete mirabile is a rare vascular anomaly, with posterior cerebral artery (PCA) involvement being especially rare. Its pathogenesis has been speculated as a remnant of "distal annexation" between the primitive anterior choroidal artery (AchA) and the PCA at this site, but the exact mechanisms remain unclear. OBSERVATIONS: A 29-year-old man presented with subarachnoid hemorrhage. Arteriovenous malformation in the medial temporal lobe was initially suspected, but an arteriovenous shunt was not detected. First, conservative treatment was administered; however, rebleeding occurred 1 month later. Carotid angiography revealed a network-like cluster of blood vessels at the choroidal point of the AchA, suggesting a rete mirabile; these vessel clusters led to the persistent temporo-occipital branch of the AchA. Furthermore, an aneurysm was detected at the junction between the rete mirabile and the persistent temporo-occipital branch of the AchA. Additionally, vertebral angiography demonstrated a rete mirabile at the P2 segment. These findings suggested the coexistence of AchA and PCA retia mirabilia. Consequently, the aneurysm was clipped using a subtemporal approach to prevent re-rupture, and the postoperative course was uneventful. LESSONS: This first report of coexisting AchA and PCA retia mirabilia supports the remnant of distal annexation between the primitive AchA and the PCA as the reason for rete formation at this site.

Nonconvulsive status epilepticus in patients with acute subarachnoid hemorrhage is associated with negative arterial spin labeling on peri-ictal magnetic resonance images.

Purpose: Non-convulsive status epilepticus (NCSE) is characterized by repetitive or continuous seizures without convulsions. Arterial spin labeling (ASL) is useful for assessing hyperperfusion due to neurovascular unit coupling in patients with NCSE; subarachnoid hemorrhage (SAH) impairs the neurovascular unit. We hypothesized that the sensitivity of ASL in detecting NCSE is low in patients with SAH during the acute phase. Methods: Based on ASL findings obtained within 48 h after the clinical suspicion of focal-onset NCSE, we divided 34 patients into ASL-negative (no hyperperfusion; n = 10) and ASL-positive (confirmed hyperperfusion; n = 24) groups. We further divided the two groups according to the NCSE etiology: patients who were diagnosed with NCSE within 14 days after SAH onset (acute SAH, n = 11) and patients with NCSE due to factors other acute SAH (n = 23) and compared their characteristics. Results: In 10 of the 34 patients (29.4 %) the ASL findings were normal. The rate of acute SAH was significantly higher in ASL-negative- (n = 8, 80.0 %) than ASL-positive patients (n = 3, 12.5 %). The rate of patients in aphasic status was significantly lower in ASL-negative patients (n = 1, 10 %) than in ASL-positive patients (n = 12, 50.0 %). Conclusion: Normal ASL findings alone should not be used to exclude a diagnosis of NCSE particularly in patients in the acute phase of SAH with deterioration or no improvement in consciousness.

Efficacy of Utilizing Both 3-Dimensional Multimodal Fusion Image and Intra-Arterial Indocyanine Green Videoangiography in Cerebral Arteriovenous Malformation Surgery.

OBJECTIVE: An understanding of the complex morphology of an arteriovenous malformation (AVM) is important for successful resection. We have previously reported the utility of intra-arterial indocyanine green (ICG) videoangiography for this purpose, but that method cannot detect the angioarchitecture covered by brain tissue. 3-dimensional (3D) multimodal fusion imaging is reportedly useful for this same purpose, but cannot always visualize the exact angioarchitecture due to poor source images and processing techniques. This study examined the results of utilizing both techniques in patients with AVMs. METHODS: Both techniques were applied in 12 patients with AVMs. Both images were compared with surgical views and evaluated by surgeons. RESULTS: Although evaluations for identifying superficial feeders by ICG videoangiography were high in all cases, the more complicated the AVM, the lower the evaluation by 3D multimodal fusion imaging. Conversely, evaluation of the estimated range of the nidus was high in all cases by 3D multimodal fusion imaging, but low in all but one case by ICG videoangiography. Nidus flow reduction was recognized by Flow 800 analysis obtained after ICG videoangiography. CONCLUSIONS: These results showed that utilizing both techniques together was more useful than each modality alone in AVM surgery. This was particularly effective in identifying superficial feeders and estimating the range of the nidus. This technique is expected to offer an optimal tool for AVM surgery.

Experience of using coronary perfusion balloon catheter for acute middle cerebral artery occlusion.

Background: We present the case of an individual with acute occlusion of the middle cerebral artery caused by atherosclerosis. The patient underwent angioplasty using a coronary perfusion balloon, which resulted in a favorable clinical outcome. Case Description: A 66-year-old male patient presented with an acute onset of right hemiplegia and dysarthria. Magnetic resonance imaging revealed an occlusion of the left middle cerebral artery, and alteplase was administered, followed by a mechanical thrombectomy and intracranial balloon catheter angioplasty. Due to restenosis, a coronary perfusion balloon catheter was used for a 15-minute angioplasty procedure while maintaining the perfusion. This treatment approach led to the recanalization of the artery and favorable clinical outcomes. Conclusion: The coronary perfusion balloon may represent a viable therapeutic alternative for the management of refractory intracranial atherosclerotic large vessel occlusion.

Activation of the NLRP3/IL-1ß/MMP-9 pathway and intracranial aneurysm rupture associated with the depletion of ERα and Sirt1 in oophorectomized rats.

OBJECTIVE: Subarachnoid hemorrhage (SAH) due to intracranial aneurysm (IA) rupture is often a devastating event. Since the incidence of SAH increases especially in menopause, it is crucial to clarify the detailed pathogenesis of these events. The activation of vascular nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasomes has been studied in ischemic stroke and cardiovascular disease. However, the role of NLRP3 in IA rupture still needs to be explained. The authors sought to test their hypothesis that, under estrogen-deficient conditions, activation of NLRP3 inflammasomes via downregulation of the estrogen receptor (ER) facilitates IA rupture. METHODS: Ten-week-old female Sprague Dawley rats with and without oophorectomy were subjected to hemodynamic changes and hypertension (OVX+/HT and OVX-/HT, respectively) and fed a high-salt diet. Separately, using human brain endothelial cells (HBECs) and human brain smooth muscle cells (HBSMCs), the authors tested the effect of NLRP3 under estrogen-free conditions and in the presence of estradiol or of ER agonists. RESULTS: In OVX+/HT rats, the frequency of IA rupture was significantly higher than in OVX-/HT rats (p = 0.03). In the left posterior cerebral artery prone to rupture in OVX+/HT rats, the levels of the mRNAs encoding ERα and Sirt1, but not of that encoding ERß, were decreased, and the levels of the mRNAs encoding NLRP3, interleukin-1ß (IL-1ß), and matrix metalloproteinase 9 (MMP-9) were elevated. Immunohistochemical analysis demonstrated that the expression profiles of these proteins correlated with their mRNA levels. Treatment with an ER modulator, bazedoxifene, normalized the expression profiles of these proteins and improved SAH-free survival. In HBECs and HBSMCs under estrogen-free conditions, the depletion of ERα and Sirt1 and the accumulation of NLRP3 were counteracted by exposure to estradiol or to an ERα agonist but not to an ERß agonist. CONCLUSIONS: To the authors' knowledge, this work represents the first demonstration that, in an aneurysm model under estrogen-deficient conditions, the depletion of ERα and Sirt1 may contribute to activation of the NLRP3/IL-1ß/MMP-9 pathway, facilitating the rupture of IAs in the estrogen-deficient rat IA rupture model.

Imaging features of a myoepithelial carcinoma of the nasal cavity: A case report and literature review.

Myoepithelial carcinoma of the nasal cavity is extremely rare. We report the case of a 66-year-old man with myoepithelial carcinoma of the nasal cavity. Computed tomography (CT) and magnetic resonance imaging revealed a lobulated soft tissue mass with central necrosis and hemorrhage, as well as an invasion of the skull base and left orbit. The patient presented with continuous nasal congestion and heavy head and had no elevated level of squamous cell carcinoma-related antigen. CT, magnetic resonance imaging, or 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT revealed no evidence of a metastatic lesion. 18F-FDG accumulation in the tumor was inhomogeneous and moderate. Histopathological examination of the resected specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was a myoepithelial carcinoma of the left nasal cavity. This case shows that nasal myoepithelial carcinoma might appear as a well-defined lobulated mass with hemorrhagic necrosis and intense contrast enhancement in the solid component. We conjecture that hemorrhagic necrosis and intense enhancement values may be potential markers of nasal myoepithelial carcinoma.

Long-sheath Introducer-assisted Revascularization (L-SHARE) Technique for Treating Large-vessel Occlusion by a Giant Clot.

Revascularization for common carotid artery (CCA) occlusion might be difficult. We reported our strategy for revascularizing CCA occlusion by giant clots. A 94-year-old woman was transferred to our hospital because of right hemiparesis and aphasia. CCA occlusion and giant clots were detected on ultrasonography. We performed mechanical thrombectomy using a 9-Fr balloon-guiding catheter, stent retriever, and aspiration catheter through a 9-Fr long-sheath introducer [long-sheath introducer-assisted revascularization (L-SHARE) technique]. We successfully recanalized CCA occlusion using this method. The L-SHARE technique might be useful for recanalization of CCA occlusion.

Stent retrieval for free-floating thrombus attached to carotid artery stenosis: A report of two cases.

Background: We report two cases who underwent mechanical thrombectomy using a stent retriever in advance of urgent carotid artery stenting (CAS) for carotid artery stenosis with free-floating thrombus (FFT). Case Description: Two patients showing symptomatic carotid artery stenosis with FFT underwent urgent endovascular surgery due to progressive neurological symptoms. The first case showed an FFT with 70% internal carotid artery (ICA) stenosis. After the completion of the common and external carotid artery balloon and distal ICA filter protection, we deployed a 6-mm-diameter stent retriever in the distal part of the stenosis. The white thrombus was retrieved; the angiographic shadow of the FFT disappeared; and CAS was performed. In the second case, due to a 90% severe stenosis lesion with FFT, balloon angioplasty was performed on the lesion using the push wire of the stent retriever. After angioplasty, the stent retriever was smoothly retrieved, and CAS was performed. Postoperative magnetic resonance imaging showed an increase in cerebral embolism in the first case; however, the patient's neurological symptoms improved. The second case showed in-stent plaque protrusion and required two additional stent placements; the patient showed no worsening of his neurological symptoms. Conclusion: In cases of carotid artery stenosis with FFT, it is technically possible to retrieve a thrombus with a stent retriever. Although thrombus removal may help reduce the risk of ischemic complications in a series of urgent CAS procedures, there are concerns such as mechanical irritation to the carotid artery plaque, and its indications and alternative treatments should be carefully considered.

Prognostic factors for acute large vessel occlusion with NIHSS 5 or lower.

BACKGROUND: Intravenous recombinant tissue plasminogen activator (IV rt-PA) and endovascular treatment have been performed for severe large vessel occlusion (LVO) and the results have been reported at high levels of evidence. However, acute treatment for LVO with mild symptom remains controversial. We retrospectively examined prognostic factors for LVO with mild symptoms. METHOD: We studied retrospectively the patients within 24 h of onset with large vessel occlusion with NIHSS score ??5. Outcomes were evaluated by modified Rankin Scale (mRS) at 90 days, with 0?2 defined as a good outcome and 3?6 as a poor outcome. Clinical characteristics of each case were examined. RESULT: Participants comprised 76 patients. Of the 76 patients. ICA occlusion showed good outcome in 17?/?19 cases (90%), whereas MCA occlusion showed good outcome in 36?/?54 cases (67%). Among the 14 cases showing positive results for distal intraarterial signal (d-IAS), outcomes were good in 6 cases (43%). On the other hand, the 32 d-IAS-negative cases showed good outcome in 28 cases (88%). Outcomes were thus significantly poorer for d-IAS-positive cases. CONCLUSION: MCA occlusion is associated with poor prognosis, even with NIHSS score ??5, and d-IAS may provide a predictor. J. Med. Invest. 70 : 22-27, February, 2023.