Microglial re-modeling contributes to recovery from ischemic injury of rat brain: A study using a cytokine mixture containing granulocyte-macrophage colony-stimulating factor and interleukin-3.

Ischemic stroke is a leading cause of mortality and permanent disability. Chronic stroke lesions increase gradually due to the secondary neuroinflammation that occurs following acute ischemic neuronal degeneration. In this study, the ameliorating effect of a cytokine mixture consisting of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-3 was evaluated on ischemic brain injury using a rat stroke model prepared by transient middle cerebral artery occlusion (tMCAO). The mixture reduced infarct volume and ameliorated ischemia-induced motor and cognitive dysfunctions. Sorted microglia cells from the ischemic hemisphere of rats administered the mixture showed reduced mRNA expression of tumor necrosis factor (TNF)-α and IL-1ß at 3 days post-reperfusion. On flow cytometric analysis, the expression of CD86, a marker of pro-inflammatory type microglia, was suppressed, and the expression of CD163, a marker of tissue-repairing type microglia, was increased by the cytokine treatment. Immunoblotting and immunohistochemistry data showed that the cytokines increased the expression of the anti-apoptotic protein Bcl-xL in neurons in the ischemic lesion. Thus, the present study demonstrated that cytokine treatment markedly suppressed neurodegeneration during the chronic phase in the rat stroke model. The neuroprotective effects may be mediated by phenotypic changes of microglia that presumably lead to increased expression of Bcl-xL in ischemic lesions, while enhancing neuronal survival.

Relationship between Deep White Matter Hyperintensities on Magnetic Resonance Imaging and Postoperative Cognitive Function Following Clipping of Unruptured Intracranial Aneurysm.

To evaluate the effects on cognitive function of deep white matter hyperintensities (DWMHs) on magnetic resonance imaging (MRI) in patients treated surgically for unruptured intracranial aneurysms (UIAs). The subjects were 106 patients in whom a Wechsler adult intelligence scale-revised (WAIS-R) examination was performed 1 week before and 1 month after clipping surgery for asymptomatic UIAs. DWMH severity was evaluated on preoperative MR images by Fazekas scale, as follows: none (absence), mild (punctate foci), moderate (beginning confluence of foci), or severe (large confluent areas). A decrease of 7 or more points in intelligence quotient (IQ) postoperatively was considered deterioration. Fazekas score was none in 41 (none group), mild in 42 (mild group), moderate in 21, and severe in 2 patients (moderate/severe group). Patient characteristics, surgical factors, IQ change, and abnormal findings on postoperative MRI were compared among the groups. Although there was no statistically significant deterioration in IQ postoperatively in any group, the percentage of deteriorated patients was significantly higher in the moderate/severe group (34.8%) than in the other groups (4.9% in the none group, 7.1% in the mild group; p <0.01, p <0.05, respectively). Brain injury was observed more frequently on postoperative MR images in the moderate/severe group (17.4%) compared with the none group (2.4%; p = 0.052). The presence of moderate/severe DWMHs was an independent prognostic factor for postoperative cognitive dysfunction. In conclusion, the presence of moderate/severe DWMHs was a prognostic factor for postoperative cognitive dysfunction after surgery for UIAs.

Comparison of the detrimental features of microglia and infiltrated macrophages in traumatic brain injury: A study using a hypnotic bromovalerylurea.

Microglia and blood-borne macrophages in injured or diseased brains are difficult to distinguish because they share many common characteristics. However, the identification of microglia-specific markers and the use of flow cytometry have recently made it easy to discriminate these types of cells. In this study, we analyzed the features of blood-borne macrophages, and activated and resting microglia in a rat traumatic brain injury (TBI) model. Oxidative injury was indicated in macrophages and neurons in TBI lesions by the presence of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Generation of mitochondrial reactive oxygen species (ROS) was markedly observed in granulocytes and macrophages, but not in activated or resting microglia. Dihydroethidium staining supported microglia not being the major source of ROS in TBI lesions. Furthermore, macrophages expressed NADPH oxidase 2, interleukin-1ß (IL-1ß), and CD68 at higher levels than microglia. In contrast, microglia expressed transforming growth factor ß1 (TGFß1), interleukin-6 (IL-6), and tumor necrosis factor α at higher levels than macrophages. A hypnotic, bromovalerylurea (BU), which has anti-inflammatory effects, reduced both glycolysis and mitochondrial oxygen consumption. BU administration inhibited chemokine CCL2 expression, accumulation of monocytes/macrophages, 8-OHdG generation, mitochondrial ROS generation, and proinflammatory cytokine expression, and markedly ameliorated the outcome of the TBI model. Yet, BU did not inhibit microglial activation or expression of TGFß1 and insulin-like growth factor 1 (IGF-1). These results indicate that macrophages are the major aggravating cell type in TBI lesions, in particular during the acute phase. Activated microglia may even play favorable roles. Reduction of cellular energy metabolism in macrophages and suppression of CCL2 expression in injured tissue may lead to amelioration of TBI.

Sustained anti-inflammatory effects of TGF-ß1 on microglia/macrophages.

Ischemic brain injuries caused release of damage-associated molecular patterns (DAMPs) that activate microglia/macrophages (MG/MPs) by binding to Toll-like receptors. Using middle cerebral artery transiently occluded rats, we confirmed that MG/MPs expressed inducible nitric oxide synthase (iNOS) on 3days after reperfusion (dpr) in ischemic rat brain. iNOS expression almost disappeared on 7dpr when transforming growth factor-ß1 (TGF-ß1) expression was robustly increased. After transient incubation with TGF-ß1 for 24h, rat primary microglial cells were incubated with lipopolysaccharide (LPS) and released NO level was measured. The NO release was persistently suppressed even 72h after removal of TGF-ß1. The sustained TGF-ß1 effects were not attributable to microglia-derived endogenous TGF-ß1, as revealed by TGF-ß1 knockdown and in vitro quantification studies. Then, boiled supernatants prepared from ischemic brain tissues showed the similar sustained inhibitory effects on LPS-treated microglial cells that were prevented by the TGF-ß1 receptor-selective blocker SB525334. After incubation with TGF-ß1 for 24h and its subsequent removal, LPS-induced phosphorylation of IκB kinases (IKKs), IκB degradation, and NFκB nuclear translocation were inhibited in a sustained manner. SB525334 abolished all these effects of TGF-ß1. In consistent with the in vitro results, phosphorylated IKK-immunoreactivity was abundant in MG/MPs in ischemic brain lesion on 3dpr, whereas it was almost disappeared on 7dpr. The findings suggest that abundantly produced TGF-ß1 in ischemic brain displays sustained anti-inflammatory effects on microglial cells by persistently inhibiting endogenous Toll-like receptor ligand-induced IκB degradation.

Plasma thrombin-cleaved osteopontin as a potential biomarker of acute atherothrombotic ischemic stroke.

We investigated whether thrombin-cleaved osteopontin N-terminal is useful as a blood biomarker of acute atherothrombotic ischemic stroke. Acute ischemic stroke patients were prospectively evaluated with brain magnetic resonance imaging and cardiac evaluations for etiological diagnosis according to the Trial of Org 10172 in Acute Stroke Treatment classification. They were divided into the atherothrombotic and non-atherothrombotic groups. Thrombin-cleaved osteopontin N-terminal, osteopontin, matrix metalloproteinase-9, S100B, C-reactive protein and D-dimer levels were measured from blood samples collected at admission. After excluding patients who met the exclusion criteria or had stroke of other/undetermined etiology, 60 of the 100 patients initially enrolled were included in the final analysis. The ischemic stroke subtypes were atherothrombotic (n=28, 46.7%), cardioembolic (n=19, 31.7%) and lacunar (n=13, 21.7%). Thrombin-cleaved osteopontin N-terminal and matrix metalloproteinase-9 levels were significantly higher in the atherothrombotic than in the non-atherothrombotic group (median (interquartile range): 5.83 (0.0-8.6 ) vs. 0.0 (0.0-3.3) pmol l-1, P=0.03 and 544 (322-749 ) vs. 343 (254-485) ng ml-1, P=0.01, respectively). After adjustment for the prevalence of hypertension, diabetes and dyslipidemia, thrombin-cleaved osteopontin N-terminal levels of >5.47 pmol l-1 (odds ratio, 16.81; 95% confidence interval, 3.53-80.10) and matrix metalloproteinase-9 levels of >605.5 ng ml-1 (6.59; 1.77-24.60) were identified as independent predictors of atherothrombosis. Within 3 h from stroke onset, only thrombin-cleaved osteopontin N-terminal independently predicted atherothrombosis and thus may add valuable, time-sensitive diagnostic information in the early evaluation of ischemic stroke, especially the atherothrombotic subtype.

A Truncated form of CD200 (CD200S) Expressed on Glioma Cells Prolonged Survival in a Rat Glioma Model by Induction of a Dendritic Cell-Like Phenotype in Tumor-Associated Macrophages.

CD200 induces immunosuppression in myeloid cells expressing its receptor CD200R, which may have consequences for tumor immunity. We found that human carcinoma tissues express not only full-length CD200 (CD200L) but also its truncated form, CD200S. Although CD200S is reported to antagonize the immunosuppressive actions of CD200L, the role of CD200S in tumor immunity has never been investigated. We established rat C6 glioma cell lines that expressed either CD200L or CD200S; the original C6 cell line did not express CD200 molecules. The cell lines showed no significant differences in growth. Upon transplantation into the neonatal Wistar rat forebrain parenchyma, rats transplanted with C6-CD200S cells survived for a significantly longer period than those transplanted with the original C6 and C6-CD200L cells. The C6-CD200S tumors were smaller than the C6-CD200L or C6-original tumors, and many apoptotic cells were found in the tumor cell aggregates. Tumor-associated macrophages (TAMs) in C6-CD200S tumors displayed dendritic cell (DC)-like morphology with multiple processes and CD86 expression. Furthermore, CD3(+), CD4(+) or CD8(+) cells were more frequently found in C6-CD200S tumors, and the expression of DC markers, granzyme, and perforin was increased in C6-CD200S tumors. Isolated TAMs from original C6 tumors were co-cultured with C6-CD200S cells and showed increased expression of DC markers. These results suggest that CD200S activates TAMs to become DC-like antigen presenting cells, leading to the activation of CD8(+) cytotoxic T lymphocytes, which induce apoptotic elimination of tumor cells. The findings on CD200S action may provide a novel therapeutic modality for the treatment of carcinomas.

Evaluation of serial changes on computed tomography and magnetic resonance imaging after implantation of carmustine wafers in patients with malignant gliomas for differential diagnosis of tumor recurrence.

Carmustine wafers are approved for localized treatment of malignant glioma. In this study, overall changes in computed tomography (CT) and magnetic resonance (MR) images of malignant glioma patients treated with carmustine wafer implantation were evaluated. The subjects were 25 patients undergoing craniotomy for malignant glioma resection and carmustine wafer implantation. Changes in the appearance of wafers, the resection cavity, and the adjacent parenchyma on CT and MR imaging were evaluated retrospectively. On CT, the wafers changed from an initially high-dense to an iso-dense appearance. All MR studies showed a low-intense wafer within 2 days. The wafers changed to a high- or iso-intense appearance on fluid attenuated inversion recovery and T1-weighted imaging, whereas they changed to an iso- to low-intense appearance on T2-weighted imaging. Gas in the cavity increased gradually after surgery, achieved a peak at 1 week postoperatively, and then disappeared in 1-3 months. Increased volume of the resection cavity was observed in 48% of patients. Regarding changes in the adjacent parenchyma, obvious contrast enhancement at the wall of the resection cavity was seen in 91% of cases at 1 month, but this disappeared gradually. Edema around the resection cavity was increased in 7 patients (28%), of whom only two experienced symptoms due to edema. We conclude that these radiological changes after carmustine wafer implantation should be carefully followed up, because these changes can easily be mistaken for infectious disease or recurrent tumors.

[A Case of Peripheral Middle Cerebral Artery Aneurysm Showing Repeated Morphological Changes].

We describe a case of a peripheral ruptured middle cerebral artery(MCA)aneurysm showing repeated morphological changes within a short period of 3 months. A 69-year-old woman was admitted to her primary care hospital with headache. Cranial computed tomography (CT) showed subarachnoid hemorrhage (SAH), but ruptured aneurysm was not confirmed on 4-vessel cerebral angiography. Conservative treatment was provided in the form of pain relief and blood pressure control. However, left internal carotid artery angiography (ICAG) conducted 12 days post-onset showed a peripheral MCA aneurysm, which was enlarged 1 week later. The patient did not tolerate balloon test occlusion, showing neurological deficit. Direct surgery was planned, but angiography on day 30 revealed a reduction in aneurysm size. Medical therapy was therefore continued for 1 month; however, the aneurysm showed repeated enlargements over 3 months. The patient therefore consulted our hospital for surgery, which was performed using a transsylvian approach. As we were unable to rule out pseudoaneurysm, we performed superficial temporal artery-MCA anastomosis as a form of trapping surgery. However, the lesion appeared to likely represent a congenital aneurysm when viewed macroscopically, so we performed neck clipping as a definitive treatment. Navigation and motor-evoked potential monitoring were useful to approach the aneurysm and predict the preservation of motor function. Histological examination revealed a congenital aneurysm with organized thrombus. The postoperative course was uneventful and the patient was discharged 2 weeks after surgery without any neurological deficit.

Usefulness of the fusion imaging of 3D-CT and MRA for carotid artery stenting with minimum use of contrast medium in patient with renal dysfunction.

Patients with severe internal carotid artery (ICA) stenosis with multiple medical problems generally undergo carotid artery stenting (CAS). However, it is difficult to perform CAS in some patients because iodinated contrast medium is hard to use. We report a patient with asymptomatic ICA stenosis and chronic renal failure, in whom successful treatment was achieved using CAS with minimal use of iodinated contrast medium. A 68-year-old man with severely chronic renal failure was consulted for treatment of left ICA stenosis. Magnetic resonance angiography (MRA) and carotid echography revealed left ICA severe stenosis, and systemic non-contrast MRA showed left femoral artery constriction, but right femoral artery to be intact. CAS was therefore performed through the right femoral artery, using non-contrast three-dimensional computed tomography (3D-CT) with MRA fusion imaging, intravascular ultrasonography, and a small amount of iodinated low-osmolar contrast medium. Postoperative course was uneventful with no aggravation of renal dysfunction, and he was discharged 7 days postoperatively. These techniques are very useful for patients with chronic renal failure, and this present case represents the first report of CAS treated by using non-contrast 3D-CT with MRA fusion image technique.

CD200+ and CD200- macrophages accumulated in ischemic lesions of rat brain: the two populations cannot be classified as either M1 or M2 macrophages.

Two types of macrophages in lesion core of rat stroke model were identified according to NG2 chondroitin sulfate proteoglycan (NG2) and CD200 expression. NG2(+) macrophages were CD200(-), and vice versa. NG2(-) macrophages expressed two splice variants of CD200 that are CD200L and CD200S. CD200(+) macrophages expressed CD8, CD68, CD163, CCL2, inducible nitric oxide synthase, interleukin-1ß, Toll-like receptor 4 and transforming growth factor ß, whilst NG2(+) cells expressed a costimulatory factor CD86. Both cell types expressed insulin-like growth factor 1 and CD200R. These results demonstrate that the two macrophage types cannot be classified as either M1 or M2.

[A case of cerebellar hemangioblastoma complicated by pregnancy and concerns about the surgical period].

We report herein a case of cerebellar hemangioblastoma complicated by pregnancy and concerns about the period in which surgery could be performed successfully. A 19-year-old woman, who was also 35 weeks pregnant, was admitted to our hospital with headache, nausea, and general fatigue. Neurological examination on admission revealed disturbed consciousness, and the patient's general condition was poor. Computed tomography and magnetic resonance imaging showed a large tumor in the cerebellar vermis along with an obstructive hydrocephalus. Computed tomographic angiography with three-dimensional reconstruction revealed feeding arteries and a draining vein in this tumor. Based on the clinical features, hemangioblastoma was suspected, and surgical excision and extraction of the fetus were scheduled. However, because of rapid neurological deterioration due to tumor progression, an emergency cesarean section was performed under general anesthesia. After extracting the fetus, the level of consciousness improved, so a tumor resection was planned after the patient's general condition improved. However, the neurological state deteriorated again due to the worsening hydrocephalus, which was suspected to be caused by the increased cerebral blood flow following uterine contraction. Emergency surgery for the brain tumor was performed two days after delivery. The tumor was resected completely and histopathological examination confirmed a diagnosis of hemangioblastoma. The postoperative course was uneventful, and the patient and newborn were discharged with no neurological deficits three weeks after the operation. This case suggested that if we encounter patients with brain tumors complicated by pregnancy, not only is earlier diagnosis from clinical features important, but also persistent additional treatment should be carried out without delay to effectively control intracranial pressure.

Utility of 3-dimensional ultrasound imaging to evaluate carotid artery stenosis: comparison with magnetic resonance angiography.

BACKGROUND: We evaluated the utility of 3-dimensional (3-D) ultrasound imaging for assessment of carotid artery stenosis, as compared with similar assessment via magnetic resonance angiography (MRA). METHODS: Subjects comprised 58 patients with carotid stenosis who underwent both 3-D ultrasound imaging and MRA. We studied whether abnormal findings detected by ultrasound imaging could be diagnosed using MRA. Ultrasound images were generated using Voluson 730 Expert and Voluson E8. RESULTS: The degree of stenosis was mild in 17, moderate in 16, and severe in 25 patients, according to ultrasound imaging. Stenosis could not be recognized using MRA in 4 of 17 patients diagnosed with mild stenosis using ultrasound imaging. Ultrasound imaging showed ulceration in 13 patients and mobile plaque in 6 patients. When assessing these patients, MRA showed ulceration in only 2 of 13 patients and did not detect mobile plaque in any of these 6 patients. Static 3-D B mode images demonstrated distributions of plaque, ulceration, and mobile plaque, and static 3-D flow images showed flow configuration as a total structure. Real-time 3-D B mode images demonstrated plaque and vessel movement. Carotid artery stenting was not selected for patients diagnosed with ulceration or mobile plaque. CONCLUSIONS: Ultrasound imaging was necessary to detect mild stenosis, ulcerated plaque, or mobile plaque in comparison with MRA, and 3-D ultrasound imaging was useful to recognize carotid stenosis and flow pattern as a total structure by static and real-time 3-D demonstration. This information may contribute to surgical planning.

Surgical results of tumor resection using tractography-integrated navigation-guided fence-post catheter techniques and motor-evoked potentials for preservation of motor function in patients with glioblastomas near the pyramidal tracts.

The current optimal surgery for glioblastomas (GBMs) near the pyramidal tract (PT) is to remove as much tumor as possible and to preserve motor function. The purpose of this study is to investigate the usefulness of tractography-integrated navigation-guided fence-post catheter techniques and motor-evoked potentials (MEPs) for preserving postoperative motor function after GBM surgery. We retrospectively examined 49 patients who underwent resection for GBM near the PT. Diffusion tensor (DT) imaging-based tractography of the PT was performed preoperatively and integrated into the navigation system. When possible, silicon catheters were used as "fence-posts" and were inserted along the tumor boundaries, avoiding the PT, before tumor removal using the navigation system (fence-post catheter techniques). Cortical and subcortical MEPs were also monitored during resection of the tumor. Fence-post catheter techniques using a tractography-integrated navigation system were used in 45 of 49 patients. This technique enabled placement of the catheters, avoided the motor pathways, and allowed easier resection of the tumors. Tumors near the PT were resected using subcortical and cortical MEPs. The amplitudes of cortical MEPs after tumor removal were maintained at over 33 % of those obtained before resection. Thirty-six patients showed obvious responses of subcortical MEPs at ≤20 mA. The degree of resection was gross total in 21 patients, subtotal in 21, and partial in seven. One month after surgery, only one patient showed worsened motor function. Therefore, fence-post catheter techniques using a tractography-integrated navigation system and MEPs may contribute to preserving motor function after surgery for GBMs that are near the PT.

Ethmoidal dural arteriovenous fistula with unusual drainage route treated by transarterial embolization.

Ethmoidal dural arteriovenous fistulas (AVFs) are rare intracranial lesions associated with a high risk of intracranial hemorrhage. In particular, this entity with reflux drainage directly into the ophthalmic vein is extremely rare. We report a case of ethmoidal dural AVF with direct drainage of the superior ophthalmic vein (SOV) and inferior ophthalmic vein (IOV), successfully treated by endovascular surgery. A 58-year-old man presented with progressive diplopia. Angiography and contrast-enhanced CT showed an ethmoidal dural AVF supplied via the bilateral anterior ethmoidal arteries and venous drainage through the left SOV and IOV. A transarterial approach through the bilateral anterior ethmoidal arteries was used to place the microcatheter close to the fistula site. After intra-arterial embolization with 20% N-butyl cyanoacrylate, the dural AVF was completely occluded. In patients with good vascular access, endovascular transarterial embolization may be an effective and less invasive treatment strategy for ethmoidal dural AVF.

[Pathogenesis of in-stent thrombosis after carotid artery stenting].

BACKGROUND AND PURPOSE: In-stent thrombosis (IST) after carotid artery stenting (CAS) is a rare complication that can lead to severe thromboembolic events. The purpose of this study was to investigate the pathogenesis of IST after CAS. PATIENTS AND METHODS: A total of 101 patients underwent CAS from January 2006 to September 2013 at our hospital. Five of these patients experienced IST. We reviewed their clinical course and treatment. In addition, we compared various parameters, including basal disease, preceding anti-platelet therapy, rate of stenosis, length of stenosis, preoperative examination, type of stent, length of stent, post dilatation, and postoperative examination, between the IST and the non-IST groups. OUTCOME: All cases in the IST group had low echoic plaque and open cell stent, and all thrombi were located at the dorsal side of the internal carotid artery and the distal side of the stent flexion. Four cases without neurological symptoms were found to have resolution of IST at 3-6 weeks after CAS with anticoagulant therapy. One case had symptomatic thromboembolism at 1 month after CAS, and the thrombus was removed along with the stent due to growth of the thrombus despite anticoagulant therapy. No significant differences were observed between the IST and non-IST groups with regard to the factors described in the methods section. CONCLUSIONS: This study did not identify factors related to IST. We hypothesize that soft plaque can easily protuberate in the context of a stent with a large cell and that protrusion plaque may increase the risk of thrombus formation in combination with turbulent flow at the site of stent flexion. Further investigation in a larger number of patients is needed to clarify the risk factors related to IST.

[Successful recanalization of intracranial internal carotid artery occlusion by rapidly changing from the Penumbra System® to the Merci® Retrieval System to retrieve a predicted white thrombus: a case report].

This report describes a case of successful recanalization of intracranial internal carotid artery occlusion by rapidly changing from the Penumbra System® to the Merci® Retrieval System for the retrieval of a predicted white thrombus. A 72-year-old man was consulted to our department with a consciousness disturbance. The patient had undergone graft placement for the management of a thoracic aortic aneurysm 14 days prior. Neurological examination revealed left-sided severe motor weakness and dysarthria. Magnetic resonance(MR)imaging showed a cerebral infarction in the territory of the right internal carotid artery(ICA), while MR angiography revealed occlusion of the right ICA. The systemic intravenous injection of recombinant tissue plasminogen activator was contraindicated, so a mechanical thrombectomy was performed. The use of the Penumbra System® failed to achieve recanalization of the right ICA;therefore, revascularization using the Merci® Retrieval System was performed. As a result, complete recanalization was achieved approximately 2 hours and 45 minutes after symptom onset. The retrieved specimen was elastic and hard, and histological examination revealed a white thrombus without endovascular organization. Postoperatively, the patient was restless for 1 day but did not show any neurological abnormalities. His postoperative course was uneventful, and he was discharged 7 days later without any neurological deficits.

Ethmoidal dural arteriovenous fistula with unusual drainage route treated by transarterial embolization.

Ethmoidal dural arteriovenous fistulas (AVFs) are rare intracranial lesions associated with a high risk of intracranial hemorrhage. In particular, this entity with reflux drainage directly into the ophthalmic vein is extremely rare. We report a case of ethmoidal dural AVF with direct drainage of the superior ophthalmic vein (SOV) and inferior ophthalmic vein (IOV), successfully treated by endovascular surgery. A 58-year-old man presented with progressive diplopia. Angiography and contrast-enhanced CT showed an ethmoidal dural AVF supplied via the bilateral anterior ethmoidal arteries and venous drainage through the left SOV and IOV. A transarterial approach through the bilateral anterior ethmoidal arteries was used to place the microcatheter close to the fistula site. After intra-arterial embolization with 20% N-butyl cyanoacrylate, the dural AVF was completely occluded. In patients with good vascular access, endovascular transarterial embolization may be an effective and less invasive treatment strategy for ethmoidal dural AVF.

Microvasculature of carotid atheromatous plaques: hemorrhagic plaques have dense microvessels with fenestrations to the arterial lumen.

BACKGROUND: Microvessels in atheromatous plaques are well known to play a role in plaque vulnerability associated with intraplaque hemorrhage, but their architecture remains unclear. The morphometry of the microvasculature and hemorrhage of human carotid atheromatous plaques (CAPs) were evaluated, and 3-dimensional (3D) reconstruction of the microvessels was performed. METHODS: CAPs were obtained by endarterectomy in 42 patients. The specimens were analyzed using light microscopy. Plaque hemorrhage was defined as an area-containing red blood cells (>1 mm2). To determine the histopathologic features of plaque hemorrhage, the plaque area was divided into 4 regions: cap, shoulder, lipid/necrotic core, and media. Then, the density of microvessels and macrophages in each region was quantified. Two representative lesions with either hemorrhagic or nonhemorrhagic plaque were cut into 90 serial sections. The sections were double stained with anti-CD34 and anti-α smooth muscle actin antibodies, scanned using a digital microscope, and reconstructed using TRI-SRF2 software. RESULTS: The hemorrhagic plaques showed a higher density of microvessels than nonhemorrhagic plaques in the shoulder, cap, and lipid/necrotic core (P=.03, .009, and .001, respectively), and there was positive correlations between its density and macrophages in each regions (P<.001, .001, and .019, respectively). 3D imaging also revealed dense microvessels with a network structure in the cap and shoulder regions of hemorrhagic plaques, and some of the vessels were fenestrated to the arterial lumen. CONCLUSIONS: The microvasculature of plaques with intraplaque hemorrhage was dense, some of which fenestrated to the arterial lumen. The pathologic 3D imaging revealed precise architecture of microvasculature of plaques.

Activated microglia in a rat stroke model express NG2 proteoglycan in peri-infarct tissue through the involvement of TGF-ß1.

We investigated activated microglia in ischemic brain lesions from rats that had been subjected to transient middle cerebral artery occlusion. Activated microglia expressing NG2 chondroitin sulfate proteoglycan (NG2) were found only in the narrow zone (demarcation zone) that demarcated the peri-infarct tissue and ischemic core. NG2(-) activated microglia were abundantly distributed in the peri-infarct tissue outside the demarcation zone. NG2(+) microglia but not NG2(-) microglia expressed both CD68 and a triggering receptor expressed on myeloid cells 2 (TREM-2), suggesting that NG2(+) microglia eliminated apoptotic neurons. In fact, NG2(+) microglia often attached to degenerating neurons and sometimes internalized NeuN(+) or neurofilament protein(+) material. Kinetic studies using quantitative real-time RT-PCR revealed that expression of transforming growth factor-ß1 (TGF-ß1) was most evident in the ischemic core; with this marker produced mainly by macrophages located in this region. TGF-ß receptor mRNA expression peaked at 3 days post reperfusion (dpr) in the peri-infarct tissue, including the demarcation zone. Primary cultured rat microglia also expressed the receptor mRNA. In response to TGF-ß1, primary microglia enhanced the expression of NG2 protein and TREM-2 mRNA as well as migratory activity. A TGF-ß1 inhibitor, SB525334, abolished these effects. The present results suggest that TGF-ß1 produced in the ischemic core diffused toward the peri-infarct tissue, driving activated microglial cells to eliminate degenerating neurons. Appropriate control of NG2(+) microglia in the demarcation zone might be a novel target for the suppression of secondary neurodegeneration in the peri-infarct tissue.

[Emergency carotid artery stenting within 24 hours after intravenous thrombolysis for acute ischemic stroke: a case report].

We report a case treated successfully by emergency carotid artery stenting(CAS)within 24 h after intravenous thrombolysis for acute ischemic stroke. An 80-year-old man was admitted to our hospital with disturbance of consciousness. Neurological examination on admission revealed severe right-sided motor weakness and motor aphasia. Magnetic resonance(MR)imaging showed cerebral infarction in the territory of the perforating artery and cortical branch of the left middle cerebral artery(MCA). MR angiography(MRA)revealed occlusion of the bilateral cervical internal carotid arteries(ICAs). Systemic intravenous injection of recombinant tissue plasminogen activator(iv rt-PA)was therefore performed 2.5h after onset. Following iv rt-PA therapy, neurological symptoms improved for 1h, but MRA and cerebral angiography revealed severe stenosis of the left cervical ICA, complete occlusion of the right cervical ICA and left MCA occlusion. Revascularization of the left cervical ICA was then performed using endovascular surgery(percutaneous transluminal angioplasty and CAS)3.5h after iv rt-PA therapy. Postoperative course was uneventful except for mild restlessness, and hyperperfusion syndrome(HPS)did not develop. Strict control of blood pressure under dexmedetomidine anesthesia allowed effective prevention of HPS. After 1 week, recanalization of the left MCA was recognized on MRA and 123I-IMP-single photon emission computed tomography. The patient was discharged with no neurological deficit after 2 weeks.