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  • Author or Editor: Hirosuke Fujisawa x
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Sadahiro Nomura, Shiro Kashiwagi, Hirosuke Fujisawa, Haruhide Ito and Kazuyuki Nakamura

✓ Fibrinogen, fibrin monomer, and D dimer were analyzed in 41 cases of chronic subdural hematoma (SDH) to characterize local rebleeding, coagulation, and fibrinolysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Chronic SDH's were divided into five groups according to their appearance on computerized tomography: high-density, isodensity, low-density, mixed-density, and layering types. The concentration of fibrinogen, which indicates rebleeding, was higher in the mixed-density (15.7 ± 3.4 mg/dl (mean ± standard error of the mean)) and layering (15.7 ± 2.6 mg/dl) types of hematoma, and lower in the low-density hematomas (1.4 ± 0.6 mg/dl) compared with the isodense hematomas (6.9 ± 1.1 mg/dl). Fibrin monomer, which indicates coagulative activity, had a distribution similar to that of fibrinogen: 87 ± 22, 18 ± 8, 175 ± 40, and 177 ± 23 µg/ml in isodense, low and mixed-density, and layering types of hematomas, respectively. The D dimer, which indicates fibrinolytic activity, was higher in the layering hematoma type (2032 ± 384 µg/ml), and lower in low-density hematomas (301 ± 164 µg/ml) compared to isodense (1310 ± 256 µg/ml) and mixed-density (1039 ± 207 µg/ml) types of hematomas.

These observations suggest the following characterization of each type of chronic SDH. The layering type is active, with a high tendency to rebleed and for hyperfibrinolytic activity. The mixed-density type has a high tendency to rebleed with lower hyperfibrinolytic activity than the layering type. The low-density hematoma is stable with a low tendency to rebleed and to fibrinolytic activity.

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Makoto Ideguchi, Koji Kajiwara, Koichi Yoshikawa, Shoichi Kato, Hideyuki Ishihara, Masami Fujii, Hirosuke Fujisawa and Michiyasu Suzuki

A very rare case of continuous hypertension and tachycardia after excision of a cerebellar hemangioblastoma at the dorsal medulla oblongata is presented. This 21-year-old man was admitted to the authors' hospital with a headache and dizziness. Radiological examination revealed a tumor located behind the dorsal medulla oblongata and compressing it substantially. The tumor was completely resected, but after the surgery the patient experienced prolonged hypertension and tachycardia. Postoperative MR imaging showed a small injury at the dorsocaudal medulla that was located at the caudal site of the nucleus of the tractus solitarius (NTS). Because the NTS has been reported to play a central role in cardiovascular regulation along with the rostral ventrolateral medulla, the authors considered it possible that the NTS injury was the cause of the prolonged elevation of sympathetic tone.

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Makoto Ideguchi, Koji Kajiwara, Koichi Yoshikawa, Shoichi Kato, Masami Fujii, Hirosuke Fujisawa and Michiyasu Suzuki

The authors present a very rare case of benign fibrous histiocytoma of the skull with increased intracranial pressure caused by sinus occlusion. A 33-year-old woman was referred for investigation of a right occipital protrusion with tenderness and double vision. She had only mild divergence insufficiency and bilateral papilledema neurologically. Imaging findings showed that the skull tumor was located at the right occipital bone with bone disruption and a compressed right sigmoid sinus. When planning the resection, caution was required to spare the collateral flow so as to manage the intracranial pressure. Immunohistochemical analysis showed that the tumor was positive for CD68, α1-antichymotrypsin, and α1-antitrypsin. From these findings, the tumor was diagnosed as a primary benign fibrous histiocytoma of the skull.

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Nobuhiro Tanaka, Masami Fujii, Hirochika Imoto, Joji Uchiyama, Kimihiko Nakano, Sadahiro Nomura, Hirosuke Fujisawa, Ichiro Kunitsugu, Takashi Saito and Michiyasu Suzuki

Object

The use of focal brain cooling to eliminate epileptic discharges (EDs) has attracted increasing attention in the scientific community. In this study, the inhibitory effect of selective hippocampal cooling on experimental hippocampal seizures was investigated using a newly devised cooling system with a thermoelectric (Peltier) chip.

Methods

A copper needle coated with silicone and attached to the Peltier chip was used for the cooling device. The experiments were performed first in a phantom model with thermography and second in adult male Sprague–Dawley rats in a state of halothane anesthesia. The cooling needle, a thermocouple, and a needle electrode for electroencephalography recording were inserted into the right hippocampus. Kainic acid (KA) was injected into the right hippocampus to provoke the EDs. The animals were divided into hippocampal cooling (10 rats) and noncooling (control, 10 rats) groups.

Results

In the phantom study, the cooling effects (9°C) occurred in the spherical areas around the needle tip. In the rats the temperature of the cooled hippocampus decreased below 20°C within a 1.6-mm radius and below 25°C within a 2.4-mm radius from the cooling center. The temperature at the needle tip decreased below 20°C within 1 minute and was maintained at the same level until the end of the cooling process. The amplitude of the EDs was suppressed to 68.1 ± 4.8% of the precooling value and remained low thereafter. No histological damage due to cooling was observed in the rat hippocampus.

Conclusions

Selective hippocampal cooling effectively suppresses the KA-induced hippocampal EDs. Direct hippocampal cooling with a permanently implantable system is potentially useful as a minimally invasive therapy for temporal lobe epilepsy and therefore could be an alternative to the temporal lobectomy.

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Hirochika Imoto, Masami Fujii, Jouji Uchiyama, Hirosuke Fujisawa, Kimihiko Nakano, Ichiro Kunitsugu, Sadahiro Nomura, Takashi Saito and Michiyasu Suzuki

✓ Local cortical cooling for termination of epileptic discharges (EDs) has recently become a focus of research. The authors report on a newly devised cooling system that uses a thermoelectric (Peltier) chip and examine the system’s performance in experimental neocortical seizures. Experiments were performed in adult male Sprague–Dawley rats after induction of halothane anesthesia. The Peltier chip was attached to a heat sink with a water channel. Two silicon tubes were connected to the heat sink, and water at 37°C was circulated in the channel. The newly designed device was placed on the surface of the cortex. Kainic acid (KA) was injected into the cortex to provoke EDs. In the nonepileptic cortex, the temperature of the cortical surface decreased to 14.8 ± 1.5°C and that 2 mm below the surface to 27.1 ± 3.1°C within 30 seconds after the start of cooling. The temperature of the heated side of the chip was maintained at approximately 36.9°C. Without water circulation, the temperature of the cortical surface decreased to 20°C but soon began to increase, peaking at 30°C. The temperature of the heated side of the chip rose to more than 60°C. The EDs, which appeared within 20 minutes after KA injection, began to decrease in amplitude immediately after cooling began and continued to decrease as the temperature of the cortex was lowered. Sufficient miniaturization and good performance of the cooling device was demonstrated. Further efforts to develop implantable cooling systems and improve existing ones should be continued.

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Yoshihiko Maeda, Sadahiro Nomura, Tetsu Kurokawa, Hideyuki Ishihara, Kei Harada, Hiroshi Yoneda, Shoichi Kato, Hirosuke Fujisawa and Michiyasu Suzuki

The authors report on the case of a girl with cerebrovascular moyamoya disease born with severe respiratory failure caused by a congenital diaphragmatic hernia. Cardiopulmonary management included extracorporeal membrane oxygenation until the diaphragm defect was repaired. The right common carotid artery (CA) was interrupted and cannulated for extracorporeal membrane oxygenation. When she was 5 years of age, the patient experienced ischemic symptoms in her right extremities. Angiography revealed stenosis of the terminal portion of the internal CA (ICA) with the development of moyamoya vessels on the left side of the brain; the right ICA was supplied by extracranial anastomotic arteries. Indirect extracranial–intracranial bypass surgery was performed in the left hemisphere, and the hypoperfusion improved. The same change in the intracranial ICA with the development of moyamoya vessels occurred on her right side when she was 7 years old. Decreased cerebral blood flow occurred twice, and the moyamoya vessels developed to compensate for the cerebral ischemia. However, the occlusion of the extracranial common CA in infancy induced extracranial anastomosis rather than moyamoya vessel proliferation, and collateral circulation was formed at the lesion site. This finding indicates that neoangiogenesis requires both cerebral ischemia and growth factors derived from the lesion.

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Hisashi Kubota, Ehichi Suehiro, Hiroshi Yoneda, Sadahiro Nomura, Koji Kajiwara, Masami Fujii, Hirosuke Fujisawa, Shoichi Kato and Michiyasu Suzuki

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Takayuki Amano, Koji Kajiwara, Koichi Yoshikawa, Jun Morioka, Sadahiro Nomura, Hirosuke Fujisawa, Shoichi Kato, Masami Fujii, Mikiko Fukui, Yuji Hinoda and Michiyasu Suzuki

Object

The receptor for hyaluronan-mediated motility (RHAMM) is frequently overexpressed in brain tumors and was recently identified as an immunogenic antigen by using serological screening of cDNA expression libraries. In this study, which was conducted using a mouse glioma model, the authors tested the hypothesis that vaccination with dendritic cells transfected with RHAMM mRNA induces strong immunological antitumor effects.

Methods

The authors constructed a plasmid for transduction of the mRNAs transcribed in vitro into dendritic cells, which were then used to transport the intracellular protein RHAMM efficiently into major histocompatibility complex class II compartments by adding a late endosomal–lysosomal sorting signal to the RHAMM gene. The dendritic cells transfected with this RHAMM mRNA were injected intraperitoneally into the mouse glioma model 3 and 10 days after tumor cell implantation. The antitumor effects of the vaccine were estimated by the survival rate, histological analysis, and immunohistochemical findings for immune cells.

Mice in the group treated by vaccination therapy with dendritic cells transfected with RHAMM mRNA survived significantly longer than those in the control groups. Immunohistochemical analysis revealed that greater numbers of T lymphocytes containing T cells activated by CD4+, CD8+, and CD25+ were found in the group vaccinated with dendritic cells transfected with RHAMM mRNA.

Conclusions

These results demonstrate the therapeutic potential of vaccination with dendritic cells transfected with RHAMM mRNA for the treatment of malignant glioma.

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Makoto Saka, Takayuki Amano, Koji Kajiwara, Koichi Yoshikawa, Makoto Ideguchi, Sadahiro Nomura, Hirosuke Fujisawa, Shoichi Kato, Masami Fujii, Koji Ueno, Yuji Hinoda and Michiyasu Suzuki

Object

The Il13ra2 gene is often overexpressed in brain tumors, making Il13ra2 one of the vaccine targets for immunotherapy of glioma. In this study, using a mouse glioma model, the authors tested the hypothesis that vaccination using dendritic cells transfected with Il13ra2 mRNA induces strong immunological antitumor effects.

Methods

A plasmid was constructed for transduction of the mRNAs transcribed in vitro into dendritic cells. This was done to transport the intracellular protein efficiently into major histocompatibility complex class II compartments by adding a late endosomal/lysosomal sorting signal to the Il13ra2 gene. The dendritic cells transfected with this Il13ra2 mRNA were injected intraperitoneally into the mouse glioma model at 3 and 10 days after tumor cell implantation. The antitumor effects were estimated based on the survival rate, results of histological analysis, and immunohistochemical findings for immune cells.

Results

The group treated by vaccination therapy with dendritic cells transfected with Il13ra2 mRNA survived significantly longer than did the control groups. Immunohistochemical analysis revealed that greater numbers of T lymphocytes containing CD4+ and CD8+ T cells were found in the group vaccinated with dendritic cells transfected with Il13ra2 mRNA.

Conclusions

These results demonstrate the therapeutic potential of vaccination with dendritic cells transfected with Il13ra2 mRNA for the treatment of malignant glioma.

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Takayuki Oku, Masami Fujii, Nobuhiro Tanaka, Hirochika Imoto, Joji Uchiyama, Fumiaki Oka, Ichiro Kunitsugu, Hiroshi Fujioka, Sadahiro Nomura, Koji Kajiwara, Hirosuke Fujisawa, Shoichi Kato, Takashi Saito and Michiyasu Suzuki

Object

Focal brain cooling has been recognized to have a suppressive effect on epileptiform discharges or a protective effect on brain tissue. However, the precise influence of brain cooling on normal brain function and histology has not yet been thoroughly investigated. The aim of this study was to investigate the neurophysiopathological consequences of focal cooling and to detect the threshold temperature that causes irreversible histological change and motor dysfunction.

Methods

The experiments were performed in adult male Sprague-Dawley rats (weighing 250–350 g) after induction of halothane anesthesia. A thermoelectric chip (6 × 6 × 2 mm) was used as a cooling device and was placed on the surface of the sensorimotor cortex after a 10 × 8–mm craniotomy. A thermocouple was placed between the chip and the brain surface. Focal cooling of the cortex was performed at the temperatures of 20, 15, 10, 5, 0, and −5°C for 1 hour (5 rats in each group). Thereafter, the cranial window was repaired. Motor function was evaluated using the beam-walking scale (BWS) every day for 7 days. The rats were killed 7 days after the operation for histological examination with H & E, Klüver-Barrera, glial fibrillary acidic protein, and terminal deoxynucleotidyl transferasemediated deoxyuridine triphosphate nick-end labeling stainings. The authors also euthanized some rats 24 hours after cooling and obtained brain sections by the same methods.

Results

The BWS score was decreased on the day after cooling only in the −5°C group (p < 0.05), whereas the score did not change in the other temperature groups. Histologically, the appearance of cryoinjury such as necrosis, apoptosis, loss of neurons, and marked proliferation of astrocytes at the periphery of the lesion was observed only in the −5°C group, while no apparent changes were observed in the other temperature groups.

Conclusions

The present study confirmed that the focal cooling of the cortex for 1 hour above the temperature of 0°C did not induce any irreversible histological change or motor dysfunction. These results suggest that focal brain cooling above 0°C has the potential to be a minimally invasive and valuable modality for the treatment of severe brain injury or to assist in the examination of brain function.