Tsukasa Fujimoto

Magnetic resonance imaging findings in cerebral fat embolism: correlation with clinical manifestations.

OBJECTIVES Cerebral fat embolism (CFE) is a serious complication after fracture of long bones. The mortality rate of CFE may be high. However, recent progress in treatment may decrease the mortality. We studied the validity of magnetic resonance imaging (MRI) to detect and grade severity of CFE in 11 patients with CFE. METHODS Glasgow Coma Scale score, PaO2, PaCO2 at the onset, and minimal hemoglobin and platelet levels were monitored, and phagocytes in bronchoalveolar lavage fluid were counted. Brain computed tomographic and MRI scans were performed serially. MRI findings were graded into four categories according to the severity of T2-weighted images. RESULTS High-intensity T2 signals were identified in the various brain regions as early as 4 hours after onset of CFE. The maximum MRI grade significantly correlated with Glasgow Coma Scale score at the onset of CFE (p < 0.01). High-intensity T2 signal lesions fused and enlarged with time. In most cases, they diminished within 2 weeks. Three patients had persistent morbidity. CONCLUSION MRI-T2-weighted imaging seems to be the most sensitive imaging technique for diagnosing CFE, and correlates well with the clinical severity of brain Injury. With the aid of proper treatment for pulmonary fat embolism, CFE is a potentially reversible disease that can have a good outcome.

Exclusively epidural arteriovenous fistula in the cervical spine with spinal cord symptoms: case report.

OBJECTIVE AND IMPORTANCE We describe the case of an epidural arteriovenous fistula (AVF) in the cervical spine draining only into the epidural and paravertebral plexus. An entirely epidural AVF having such drainage is extremely rare. CLINICAL PRESENTATION A 24-year-old man presented with a 4-month history of gradually progressive sensory and motor disturbances of the upper and lower extremities. Magnetic resonance imaging and magnetic resonance angiography revealed a peridural vascular lesion within the canal compressing the spinal cord from C5 to T2. Diagnostic angiography revealed a perimedullary and/or dural high-flow AVF, fed mainly by branches of ascending cervical and deep cervical arteries. The fistula drained into the epidural and paravertebral venous plexus without reflux into intradural venous systems. INTERVENTIONMultiple feeders of the AVF were embolized with a Liquid coil and n-butylcyanoacrylate via a two-step procedure. One week after embolization, the AVF was surgically removed. CONCLUSIONInteresting points of this case were the exclusively epidural location of the lesion, the exclusively epidural drainage of the AVF, and the etiology of the symptoms. Venous drainage of the fistula had no relation to any dural or intradural veins. Initially, spinal cord and nerve root compression by extradural veins with varicose dilation seemed to cause the radiculopathy and/or the myelopathy, and subsequent myelopathy caused by spinal venous hypertension was believed to be the main etiology in this case.

Astrocytes co-express aquaporin-1, -4, and vascular endothelial growth factor in brain edema tissue associated with brain contusion

INTRODUCTION Brain edema may be life threatening. The mechanisms underlying the development of traumatic brain edema are still unclear; however, mixed mechanisms including vasogenic, ischemic, and neurotoxic types of edema may be contributors. Recent studies indicate that astrocytes, aquaporins (AQPs; a protein family of water channels), and vascular endothelial growth factor (VEGF) may have important roles in the formation and resolution of brain edema. We studied the expression of AQPs and VEGF in the edematous brain. METHODS We investigated the expression of AQP1, AQP4, and vascular endothelial growth factor (VEGF) in contusional brain tissue surgically obtained from 6 patients. Glial fibrillary acidic protein (GFAP) was also stained to detect astrocytes and to clarify the location of those proteins. The specimens received immunohistological staining and 3-color immunofluorescent staining, and were observed using confocal laser scanning microscopy. RESULTS AQP1, AQP4, and VEGF were co-expressed in GFAP-positive astrocytes. AQP1 and AQP4 were expressed strongly in astrocytic end-feet. The astrocytes were located in the edematous tissue, and some cells surrounded cerebral capillaries. CONCLUSION Our results suggest that AQP1, AQP4, and VEGF are induced in astrocytes located in and surrounding edematous tissue. Those astrocytes may regulate the water in- and out-flow in the injured tissue.

Immunohistochemical analysis of reactive astrocytes around glioblastoma: an immunohistochemical study of postmortem glioblastoma cases

To investigate the mechanisms of proteolysis within the glioma, and tissue reactions against glioblastoma, immunohistochemical detection both outside and inside of the tumor was performed using seven brains with glioblastoma that were obtained from autopsies. Immunohistochemistry was performed to detect vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMP)-1,-2,-9, membrane-type matrix metalloproteinase (MT-MMP), interleukin (IL)1-beta, and IL-6. The data were translated into color graphics and the localization of these proteins was analyzed. In glial cells around the tumor, GFAP, VEGF, MMP-2, and MT-MMP were strongly expressed. Moreover, IL1-beta was also expressed strongly in the glial cells at the periphery of the tumor. IL-6 was recognized outside of the tumor, but was expressed only in the swollen astrocytes and normal pyramidal cells. These data suggest that in the periphery of the tumor, tissue reconstruction processes take place with concomitant degradation of the matrix by MMP-2 and MT-MMP, as well as vascular remodeling promoted by VEGF. The fact that IL1-beta, but not IL-6, was expressed strongly in the glial cells around the tumor, may indicate that these proteins expressed outside of the tumor are not utilized for tumor growth, but may be used to guard the tumor against invasions, such as immune response.

Progressive expression of vascular endothelial growth factor (VEGF) and angiogenesis after chronic ischemic hypoperfusion in rat.

Cerebrovascular stenosis caused by arteriosclerosis induces failure of the cerebral circulation. Even if chronic cerebral hypoperfusion does not induce acute neuronal cell death, cerebral hypoperfusion may be a risk factor for neurodegenerative diseases. The purpose of this study was to determine if vasodilation, expression of VEGF, and neovascularization are homeostatic signs of cerebral circulation failure after permanent common carotid artery occlusion (CCAO) in the rat. Neuronal cell death in neocortex was observed 2 weeks after CCAO and gradually increased in a time-dependent manner. The diameter of capillaries and expression of VEGF also increased progressively after CCAO. Moreover, we observed unusual irregular angiogenic vasculature at 4 weeks. In conclusion, chronic hypoperfusion results in mechanisms to compensate for insufficiency in blood flow including vasodilation, VEGF expression, and neovascularization in the ischemic region. These results suggest that angiogenesis might be induced in adult brain through the support of growth factors and transplantation of vascular progenitor cells, and that neovascularization might be a therapeutic strategy for children and adults with diseases such as vascular dementia.

Graphic analysis of microscopic tumor cell infiltration, proliferative potential, and vascular endothelial growth factor expression in an autopsy brain with glioblastoma

BACKGROUND Growth of brain tumors requires tumor-cell attachment to adjacent structures, degradation of surrounding matrixes, migration of tumor cells, proliferation of vasculature, and tumor cell proliferation. Comparison of the findings on neuroimaging, degrees and patterns of tumor invasion, regional tumor cell viability detected by Ki-67 immunohistochemistry, and regional vascular endothelial growth factor (VEGF) expression in whole-brain specimen of glioblastoma therefore is of great interest, and will facilitate study of the host reaction against the glioblastoma. METHODS We graphically analyzed microscopic tumor-cell infiltration, regional differences in Ki-67 labeling indices (LI), and immunohistochemical expression of VEGF in an autopsy brain with glioblastoma. RESULTS Glioblastoma cells infiltrated the brain far beyond the gross limits of the tumor and the areas with high signal intensity on T2-weighted magnetic resonance images. A wide range of histologic malignancy was apparent from hematoxylin-eosin staining and the Ki-67 labeling indices. VEGF was highly expressed in normal astrocytes located outside the tumor. CONCLUSION Graphic analysis of histologic and immunohistochemical patterns is a useful method of investigating the mechanisms of glioma growth, tumor cell infiltration in the brain, and the host reaction of the brain against neoplasms.

Different distribution of c-myc and MIB-1 positive cells in malignant meningiomas with reference to TGFs, PDGF, and PgR expression

We investigated the expression of transforming growth factors (TGFs), platelet-derived growth factor (PDGF), progesterone receptor (PgR), and c-myc in 20 cases of meningioma of various grades: 17 benign, 2 atypical, and 1 anaplastic. All cases of atypical and anaplastic meningioma were positive for c-myc, whereas all 17 benign meningiomas were negative for c-myc immunostaining. Expression of TGF-α, TGF-β, and PDGF-BB proteins was seen in more than 80% of the meningioma cases and was not restricted to their histological grade of meningioma. PgR was expressed mainly in benign meningiomas. Moreover, the cells expressing c-myc protein were not usually stained by MIB-1. These results indicate that c-myc does not directly work on the proliferation of meningioma cells, and even in homogeneous meningioma cells, there may be many functional variations that lead the meningioma cells to their growth.

Dural invasion of meningioma: a histological and immunohistochemical study

Meningioma usually grows and expands into the brain, but invasion into the brain parenchyma is relatively rare. Meningioma arises from arachnoid cap cells, and infiltration into dura mater is the main growth pattern of meningiomas. However, little is known about the mechanism of meningioma invasion into the dura mater. In this study, seven specimens, including dural attachments, from seven cases of meningioma were used for immunohistochemical analysis. Matrix metalloproteinase (MMP)-1, -2, -9, urokinase-type plasminogen activator (uPA), vascular endothelial growth factors (VEGF), flt-1, E-cadherin, estrogen receptor (EgR), progesterone receptor (PgR), and aquaporin (AQP)-1, -4 were used as primary antibodies. There were several patterns of meningioma invasion into the dura mater: papillary-shaped invasion with destruction of dural structure, infiltration along the fibers of the dura mater, and invasion of several tumor cell units with fibroblast infiltration. Strong immunostaining was obtained with MMP-1, followed by AQP-1 and uPA, within the invading tumor cells. Neovasculature and extravasated erythrocytes, which stained with AQP-1, were also occasionally observed around the invading tumor cells. Simpson grade II removal of meningiomas results in high recurrence rates, and the inhibition of meningioma growth via dural invasion will facilitate improved remission in many cases with meningioma. In this study, MMP-1, AQP-1, and uPA are considered to have some role in the dural infiltration of meningioma cells. The fact that AQP-1 was highly expressed at the dural attachment and invading front of meningioma may indicate that dural invasion of the meningioma may be facilitated by AQP-1-induced water flow and neovascularization.

Meningoencephalocele Associated with Tripterygium wilfordii Treatment

We treated a male infant with occipital meningoencephalocele associated with the taking of Tripterygium wilfordii. The infant was delivered normally at 38 weeks of gestation with a huge cystic mass protruding from the occiput. He was diagnosed with occipital meningoencephalocele and cerebellar agenesis. His mother had taken T. wilfordii for rheumatoid arthritis early in her pregnancy. T. wilfordii is a herbal medicine used for rheumatoid arthritis and male contraception. Since its toxicity is high and its use during pregnancy is restricted, it is the most likely cause of this infants anomalies.

Fluorescence automatic cell sorter and immunohistochemical investigation of CD68-positive cells in meningioma

Infiltration of brain neoplasms by mononuclear cells including monocytes/macrophages has attracted little attention since they have marked morphological heterogeneity. Twenty-seven meningiomas were studied by anti-CD68 antibody-gated flow cytometry and by immunohistochemical analysis using the anti-CD68 antibodies. Flow cytometric analysis divided cells contained within tumor tissues into CD68-positive and -negative cells. In addition, eight gliomas, eight metastatic brain tumor, and 12 pituitary adenomas were investigated in the same way to compare meningiomas. The mean contents of CD68-positive cells were 24.0 +/- 3.7% in meningiomas, 4.4 +/- 1.4% in gliomas, 9.5 +/- 3.9% in metastatic brain tumors, and 4.5 +/- 1.8% in pituitary adenomas. Immunohistochemically, CD68-positive cells showed significant heterogeneity and were detected as round, rod-shaped, ameboid and ramified cells in meningiomas. Although the infiltrated mononuclear cells in gliomas have been investigated to some degree and showed that they express cytokines and/or growth factors, these infiltrated cells in meningioma have barely been studied. The CD68-positive cells detected in this study are likely to be monocytes, macrophages and microglias, and are presumed to be in various functional stages and to play important roles in growth regulation in meningioma.