Michio Fujimoto

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.

The effect of hematoma removal for reducing the development of brain edema in cases of putaminal hemorrhage.

INTRODUCTION Surgical intervention in putaminal hemorrhage has been a controversial issue. The aim of this research is to evaluate the benefits of surgery for reducing the development of brain edema. MATERIALS AND METHODS Sixteen cases of putaminal hemorrhage were examined. Eight patients were treated conservatively (C group), and the other 8 patients were treated surgically (S group). Head CT scans were performed on the day of onset (day 0) in C group or performed just after surgery (day 0) in S group, and performed again once per period on days 1-7, 8-14, and 15-21. The volume of the mass including hematoma and edema (H + E) was measured using CT scans and the (H + E)/H0 ratios were calculated (H0; hematoma volume on day 0). The (H + E)/H0 ratios for each period were compared statistically between the 2 groups using a t-test. RESULTS The mean values of(H + E)/H0 ratios at each period were 2.19, 2.63, 2.53 in C group, and 1.29, 1.29, 0.66 in S group. The values in S group were significantly lower as compared with C group in every period (p < 0.01, < 0.05, < 0.01). CONCLUSIONS Hematoma volume reduction by surgery reduced the development of brain edema.

Tissue reconstruction process in the area of peri-tumoural oedema caused by glioblastoma--immunohistochemical and graphical analysis using brain obtained at autopsy.

BACKGROUND In the area of peri-tumoural oedema, proteolytic agents derived from the tumour cause tissue degradation, which promotes tumour cell invasion. METHOD We investigated the biological processes in the area of peri-tumoural oedema, using a brain obtained at autopsy from a patient who died from glioblastoma. Immunohistochemistry was performed to detect vascular endothelial growth factor (VEGF), c-myc, p53, paternally expressed gene-3 (PEG-3), transforming growth factor beta (TGFB), and tumour necrosis factor alpha (TNFA). The data were translated into colour graphics and the localization of these proteins was analyzed. FINDINGS In the area of peri-tumoural oedema, Ki-67 and p53 positive cells were observed with TGFB expression. Moreover, c-myc, PEG-3, VEGF, and TNFA were also expressed strongly in the glial cells or extra-cellular spaces in the area of peri-tumoural oedema. INTERPRETATION These data suggest that in the area of peri-tumoural oedema, tissue reconstruction processes take place with concomitant anti-tumour activities. The expression of c-myc, VEGF, and TNFA in the area of peri-tumoural oedema may indicate that these proteins are not utilized for tumour growth, but may be used to guard the brain against tumour invasion. Peri-tumoural oedema does not only indicate the tissue damage caused by tumour, but many tissue reconstruction processes take place in these areas against tumour cell invasion.

Intracranial Bony Canal of the Middle Meningeal Artery - Morphological and Histological Analysis.

The middle meningeal artery (MMA) can play an important role in the surgical revascularization. However, the MMA can be easily injured if it passes through a bony canal. We investigated the morphological and histological features of the bony canal to improve surgical results. MATERIALS AND METHODS Fifty adult dry skulls were investigated. The length of the bony canal and the distance from the orbital rim to the bony canal were measured. Additionally, 28 cadaveric heads were examined histologically. RESULTS Sixty-three bony canals were found in 43 skulls. The mean length of bony canals was 9.2 mm, and the mean distance from the orbital rim was 24.0 mm. The bony canal ran mainly from the sphenoid bone (69.8%) to the parietal bone (73.0%). Histologically, both sides of the meningeal grooves gradually closed the distance, and formed the bony canal. The MMA inside the bony canal was enveloped with collagen tissues, divided into branches, and was accompanied by the vein. CONCLUSIONS The bony canal is located around the pterion and is formed during bone growth. The MMA is covered with collagen tissues inside the bony canal. It is possible to safely expose and preserve the MMA during craniotomy with careful drilling.

Continuous Echo‐guided Surgery in Brain Tumour Removal

Conventional intraoperative echo‐guided surgery through a cranial window has several problems such as, 1) the echo probe has to be applied intermittently 2) initially, clear images can be obtained, but during the operation the images deteriorate. Therefore, we have developed a new method to obtain clear echo images through the whole process of the surgery. We created another small cranial window at the opposite side of the operating field, into which an echoprobe was inserted. Using this method, we could see clear images throughout the operation and could perform the required surgery safely.