Goro Nagashima

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.

Immunohistochemical detection of progesterone receptors and the correlation with Ki-67 labeling indices in paraffin-embedded sections of meningiomas

Female sex steroids may play a role in the proliferation of meningiomas. We investigated the progesterone receptor (PgR) immunoreactivities and the Ki-67 labeling indices in the formalin-fixed, paraffin-embedded sections of meningiomas from 39 patients. After autoclave pretreatment of the sections (which were immersed in a citrate buffer), the sections were incubated with the monoclonal antibody for the PgR and the MIB-1 monoclonal antibody for the Ki-67 antigen. In the meningiomas studied, the immunoreactivity for the PgR was moderately to strongly positive in 51%, weakly positive in 21%, and negative in 28%. The nuclear staining for the PgR was clear, and no tumors were positive for the estrogen receptor. The Ki-67 labeling indices of the PgR-positive meningiomas (mean +/- standard deviation, 2.35 +/- 2.12%) were significantly lower than those of the PgR-negative meningiomas (6.53 +/- 4.83%) (P < 0.05). Two meningiomas that had recurred more than once showed high Ki-67 labeling indices and negative immunostaining for the PgR. These findings indicate that the PgR status may be closely related to the growth potentials of the meningiomas. Our results confirm that the immunodetection of the PgR and the Ki-67 antigen on the paraffin sections of meningiomas provides a practical tool for estimating the biological behavior of the meningiomas.

Tumour suppressor activity of human imprinted gene PEG3 in a glioma cell line

Mouse imprinted gene Peg3 encodes a large C2H2 type zinc finger protein with unique characteristics. Peg3 knockout mice were found to show an impairment in maternal behaviour of the adult female. Mouse Peg3 is located on the proximal region of chromosome 7 which is syntenic to the long arm of human chromosome 19. It has been reported that a loss of heterozygosity (LOH) of chromosome 19q occurs frequently in several glioma types.

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.

Immunolocalization of matrix metalloproteinases in rabbit carotid arteries after balloon denudation

Abstract Extracellular matrix-degrading enzymes may play a key role in vascular remodeling after arterial wall injury. We investigated the immunolocalization of matrix metalloproteinases (MMPs) in rabbit carotid arteries after balloon denudation. Positive immunostaining for MMP-1, -2, -3, and -9 appeared through the neointima 1 week after balloon denudation. The localization of immunopositive smooth muscle cells (SMCs) for MMP-1, -3, and -9, particularly for MMP-9, was almost similar to that of replicative SMCs and became confined to the luminal surface layer of the neointima at later time periods. However, MMP-2-positive SMCs appeared also in the basal layer of the neointima at 2 weeks, increased at 4 weeks, and then totally occupied the neointima at 6 weeks. The MMP-2-positive SMCs in the basal layer of the neointima at 4 and 6 weeks were negative for proliferation-associated antigens and were surrounded by extracellular matrix proteins. Our results suggest that all MMPs act in coordination to promote replication and migration of SMCs in the earlier phases of neointimal formation and that MMP-2 independently contributes to the later stages by facilitating the migration but not replication of SMCs from the media to the intima.

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.

P53 Overexpression and Proliferative Potential in Malignant Meningiomas

Summary Meningiomas are generally benign, but some meningiomas show malignancy with invasion and high recurrence rates. We investigated whether alterations in p53 protein may contribute to malignant progression in meningiomas. Immunostaining for p53 protein was performed on paraffin and frozen sections from 61 patients with different grades of meningiomas using monoclonal antibodies (mAbs) DO-1 and pAb240. Immunoblot analysis was performed to quantitate the amount of p53 protein. Mutations in p53 genes were assessed by single-strand conformational polymorphism (SSCP) analysis. MIB-1 immunostaining was used to detect proliferative potentials of meningiomas. We found an overexpression of p53 protein in all of five cases of anaplastic meningiomas by immunohistochemistry using DO-1 mAb. No p53 positive cells were recognized in atypical meningiomas, and several cells were weakly stained in only two of 52 benign meningiomas. p53 staining index and immunoblot analysis indicated increasing amounts of p53 protein associated with subsequent recurrences of anaplastic meningiomas. The MIB-1 staining index was positively correlated with tumour grade and p53 protein overexpression. Immunostaining of frozen sections using the mutant-specific mAb pAb240, as well as mutation gene analysis by SSCP, indicate that the overexpressed p53 protein is not a mutant- but wild-type p53 protein. Four atypical meningiomas did not recur after surgical removal and radiation, while 4 anaplastic meningiomas with overexpressed p53 protein recurred repeatedly at short intervals even after radiation. Our results suggest that accumulation of p53 protein associated with highly proliferative potentials is a common and characteristic feature that may indicate malignant biological behaviour in meningiomas.

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.