Ken-ichi Matsumura

Meningioma: proliferating potential and clinicoradiological features.

We examined the proliferative potentials of meningiomas in 120 patients using the MIB-1 antibody against the Ki-67 antigen and compared them with the clinicoradiological features. The Ki-67 staining index (SI) did not relate to the age and sex of the patients or the location of the tumors. Asymptomatic meningiomas showed significantly lower SIs (mean +/- standard deviation [SD], 0.87 +/- 0.56%) than symptomatic meningiomas (mean +/- SD, 1.63 +/- 2.17%). We found no relation between SIs and clinical symptoms and signs in the symptomatic meningiomas. A weak correlation was found between the size of tumors and Ki-67 SIs (r = 0.21; P = 0.024). There were significant differences in SIs between calcified (mean +/- SD, 0.77 +/- 0.41%) and noncalcified tumor (mean +/- SD, 1.75 +/- 2.25%). Diffusely calcified tumors (mean +/- SD, 0.57 +/- 0.34%) showed lower SIs than focally calcified tumors (mean +/- SD, 0.92 +/- 0.41%). Lobulated tumors showed higher SIs (mean +/- SD, 2.85 +/- 3.68%) than round tumors (mean +/- SD, 1.06 +/- 0.67%). Tumors with perifocal edema or unclear borders had higher SIs than did those without such features. Signal intensities on T1-weighted magnetic resonance images had no relation to SIs, whereas low-intensity tumors on T2-weighted images, most of which presented diffuse calcification on computed tomographic scans, showed lower SIs. This study indicates that several clinicoradiological features relate to the proliferative potential of meningiomas and that they may contribute to the management of patients.

Interface between the meningioma and the brain on magnetic resonance imaging

Magnetic resonance imaging of 31 meningiomas in 29 patients was retrospectively reviewed and compared with pathologic specimens in 25 tumors to investigate how magnetic resonance imaging could delineate a tumor-brain interface. The thick, collagenous connective tissue, which was seen around four tumors, was shown as a low signal intensity rim on both a T1-weighted image and a T2-weighted image. A rim of low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted image most likely represented cerebrospinal fluid space: this finding was seen around eight tumors. No distinct rim could be identified in five tumors. Of these five, two tumors grew invasively into the brain. Although mixed features predominated in meningiomas, magnetic resonance imaging could well delineate a tumor-brain relationship in most of the cases.

Magnetic resonance imaging with aneurysmal subarachnoid hemorrhage : comparison with computed tomography scan

Magnetic resonance studies of 27 consecutive preoperative and 33 postoperative patients with cerebral aneurysm and subarachnoid hemorrhage were reviewed. Magnetic resonance imaging using a 0.5- or 0.22-Tesla unit was at least as accurate as computed tomography scan for detection of acute subarachnoid hemorrhage. Magnetic resonance imaging was superior to computed tomography scan for demonstrating blood in the ventricles or posterior fossa subarachnoid space, transependymal migration of the cerebrospinal fluid, and several kinds of iatrogenic intracranial pathologies in postoperative patients. Ischemic lesions, particularly fresh lesions caused by delayed cerebral vasospasm, were much better shown on magnetic resonance imaging than on computed tomography scan. Nonferromagnetic Sugita clips caused significant artifacts, but the area of artifacts was consistently smaller, and a reasonable evaluation of structures relatively closer to the clip was possible with magnetic resonance imaging rather than computed tomography scan.

Circumstances Precipitating Aneurysmal Subarachnoid Hemorrhage

To determine the precipitating factors of aneurysmal rupture, the medical records of 425 consecutive patients with aneurysmal subarachnoid hemorrhage were reviewed. As for the time of onset, a signifi

Immunohistochemical localization of glycosaminoglycans in experimental rat glioma models

Changes of glycosaminoglycan distribution in and around C6 glioma and ethylnitrosourea(ENU)-induced glioma in rats were investigated using monoclonal antibodies that specifically recognize epitopes on chondroitin-0-sulfate proteoglycan (C-0-S), chondroitin-4-sulfate proteoglycan (C-4-S), dermatan sulfate proteoglycan (DS), chondroitin-6-sulfate proteoglycan (C-6-S) and keratan sulfate proteoglycan (KS) after chondroitinase ABC digestion. In the normal brain tissues, C-0-S was located on the surface of the neurons. In addition, extracellular staining in the cerebral cortex and axoplasmic staining in the brain stem and the reticular thalamic nucleus were seen. C-0-S was negative, however, both in the C6 and ENU-induced gliomas. C-4-S or DS was detected only in some of the neurons in the normal brain tissues. They were detected in the peripheral part of the ENU-induced gliomas, but not in the C6 gliomas. C-6-S was located on the surface of some neurons and in the white matter of the normal brain, but it was not detected in C6 gliomas. In all ENU-induced gliomas, C-6-S was identified in the adventitia of the vascular structures within the tumor. In some of them, C-6-S appeared in the peripheral part of the tumor. KS was immunostained in the glial cells in the hippocampus, corpus callosum, brain stem, and the floor of the third ventricle. It was also detected in the peritumoral brain tissues both in the C6 and ENU-induced rat gliomas. The significance of glycosaminoglycans in these glioma models was discussed.

Lectin histochemistry of normal and neoplastic peripheral nerve sheath

The binding patterns of lectins to normal peripheral nerves were examined. Twelve biotinylated lectins were used in this study; Canavalia ensiformis (Con A), Pisum sativum (PSA), Lens culinaris (LCA), Ricinus communis 1 (RCA-1), Arachis hypogaea (PNA), Glycine max (SBA), Sophora japonica (SJA), Bandeiraea simplicifolia 1 (BSL-1), Triticum vulgaris (WGA), succinylated WGA (s-WGA), Ulex europaeus 1 (UEA-1) and Helix pomatia (HPA). Cytoplasm of Schwann cells and perineurial cells was stained by Con A, PSA, LCA, s-WGA and WGA. PNA showed specific binding to perineurial cells, while after neuraminidase treatment stain with this lectin was demonstrated also in Schwann cells. Myelin sheaths were stained with fewer lectins. SBA and HPA with sialic acid removal rarely showed reactivity to the peripheral nerve structure in surgical specimens, in contrast to clear staining of Schwann cells, perineurial cells and myelin sheaths in autopsy specimens. The present study shows distinct lectin stainings of specific structures of the normal human peripheral nerves, and provides important basic information on the alterations of lectin binding patterns during pathological processes in the peripheral nerves.

MRI of vertebrobasilar disecting aneurysms: diagnostic value and pitfalls of spin-echo sequences

Magnetic resonance imaging (MRI) features of 12 cases with vertebrobasilar dissecting aneurysms (VBDA) were compared with those of 80 cases with nondissecting aneurysms (NDA). Seven patients with VBDA showed an eccentrically narrowed true lumen adjacent to the semilunar clot in the false lumen. Such findings were also found in patients with thrombosed NDA. However, the segment of the mural haematoma was longer in those with VBDA. An intimal flap was detected in only 3 cases of VBDA. Two patients with VBDA showed only iso- or high signal intensity of the vertebral artery; therefore, differentiation from obstruction of the vertebral artery was difficult. Flow-dependent spatial misregistration, seen adjacent to the normal vessels, sometimes mimics intramural haematoma.