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Toshiki Yoshimine and Takehiko Yanagihara

✓ The authors have created an experimental model of regional cerebral ischemia in gerbils that is reproducible and has a low mortality rate. In gerbils, either the posterior communicating artery (PCoA) or the middle cerebral artery (MCA) was occluded, and the distribution of cerebral ischemia from each surgical procedure was compared with that produced by occlusion of the common carotid artery (CCA). In contrast to the widespread cortical and subcortical infarctions seen after occlusion of the CCA, occlusion of the PCoA caused infarction that was restricted to the hippocampus, the piriform cortex, and the posterior part of the thalamus, and occlusion of the MCA resulted in infarction that was restricted to the central part of the cerebral hemisphere and the caudate nucleus and putamen. Intracranial occlusion of the PCoA or MCA in the gerbil resulted in lesions that were reproducible with low mortality rates over a long-term period. Occlusion of the PCoA, MCA, or CCA also produces a model that is suitable for investigation of the postischemic period. A combination of these three experimental models is useful for investigation of regional vulnerability and for the study of regional metabolic differences in cerebral ischemia.

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Toru Hayakawa, Kiyoo Kamikawa, Toshiteru Ohnishi, and Toshiki Yoshimine

✓ The authors describe the techniques employed in three patients with basilar artery aneurysms that were treated via the transoral transclival approach. To prevent the formation of cerebrospinal fluid fistulas and the risk of consequent meningitis, complete postoperative closure of the nasopharyngeal mucosa is essential. Long-term nasopharyngeal packing and continuous spinal drainage were found to be effective in these cases.

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Kazuo Yamada, Toru Hayakawa, Toshiki Yoshimine, and Yukitsks Ushio

✓ A model of transient hindbrain ischemia in Mongolian gerbils is described. The vertebrobasilar junction of gerbils was exposed by a transcervical approach through the space between the atlas and occipital bone. The origin of the basilar artery was occluded by a clip, and the local cerebral blood flow (CBF) was measured with carbon-14-iodoantipyrine autoradiography. This gerbil model produces ischemia in the thalamus, midbrain, pons, medulla, and cerebellum, where blood flow is supplied from the vertebrobasilar system. Recirculation of blood flow was easily accomplished by removing the clip. Local CBF returned to normal levels immediately after recirculation, then decreased at 30 minutes after recirculation (postischemic hypoperfusion). Almost no effects of local CBF in the forebrain structures were noted during and after hindbrain ischemia. The model may be useful to study the pathophysiological, metabolic, and histopathological effects of ischemia in the vertebrobasilar system.

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Shigeki Kubo, Hiroyuki Nakata, and Toshiki Yoshimine

✓ The authors used an endoscopic threaded imaging port that originally was developed for laparoscopy to access the peritoneal cavity, and applied this device to the placement of a peritoneal shunt tube in patients suffering from hydrocephalus. Using this system, the peritoneum can be opened quickly under direct vision by using an endoscope through a small skin incision. The peritoneal cavity is secured by replacing the cannula with a polyvinyl chloride (PVC) tube. At the end of surgery, the terminal end of the shunt tube is inserted through the PVC tube, which serves as a guiding catheter. Only one or two skin stitches are needed for closure. This method has proved to be safe, quick, and less invasive than conventional minilaparotomy.

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Kazumi Yamamoto, Fumiharu Akai, Toshiki Yoshimine, and Takehiko Yanagihara

✓ Progression and recovery of ischemic and postischemic damage after occlusion of the middle cerebral artery and subsequent reperfusion were investigated in the gerbil. This study was performed by immunohistochemical reaction testing for tubulin and creatine kinase BB-isoenzyme to visualize the neuronal structure and by immunohistochemical reaction testing for astroprotein (an astrocyte-specific protein) to visualize reactive astrocytes. The earliest ischemic lesion became visible in the frontoparietal cortex after 7 minutes of ischemia as a laminar loss of the reaction for tubulin involving the neuropil, neuronal perikarya, and dendrites. The earliest lesion in the caudoputamen evolved after 30 minutes of ischemia. After reestablishment of cerebral circulation, the immunohistochemical ischemic lesions in the neuronal structure disappeared if the ischemic period was 10 minutes or less and partially disappeared even after ischemia for 15 minutes in the cerebral cortex, while the postischemic lesion in the caudoputamen disappeared even after ischemia for 15 minutes. Reactive astrocytes were detected in the cerebral cortex and caudoputamen as early as 24 hours after reperfusion, both in the areas with and without the neuronal lesions. No lesion was identified in the hippocampus or thalamus. This experimental model is suitable for investigation of rapidly progressive regional ischemia in the cerebral cortex and for comparison with other regional or global cerebral ischemia in the gerbil or other animal species.

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Shigeki Kubo, Hiroshi Hasegawa, Toshihiko Inui, Shinsuke Tominaga, and Toshiki Yoshimine

✓ Reconstruction of the sellar floor after pituitary tumor removal is sometimes difficult because the repair graft is difficult to handle in the narrow space. This is especially problematic if the endonasal endoscopic approach is used. The authors devised a technique to facilitate this procedure by placing a suture knot on the repair splint. This allows the material to be grasped securely with forceps and improves manipulation even within the narrow nasal cavity. This technique has proved useful when performing the endonasal endoscopic approach, and it is also expected to be useful when conducting the conventional sublabial transsphenoidal approach.

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Shingo Toyota, Hiroshi Takimoto, Jun Karasawa, Amami Kato, and Toshiki Yoshimine

Object. The purpose of this study was to analyze the change in cardiac sympathetic function by performing a 123I-metaiodobenzylguanidine (MIBG) imaging study after endoscopic upper thoracic sympathectomy (EUTS) in patients with palmar hyperhidrosis before and after surgery.

Methods. Between February 1999 and February 2002, 135 patients underwent bilateral EUTS to treat palmar hyperhidrosis. Between September 2001 and February 2002, 12 of these consecutively enrolled patients were also included in a 123I-MIBG imaging study. These patients underwent cardiac 123I-MIBG imaging 1 day before and 7 days after they had undergone EUTS. The heart/mediastinum (H/M) ratio and the washout rate were calculated for both early and late phases, and single-photon emission computerized tomography (SPECT) imaging of the early phase was performed.

Excessive perspiration from the palms disappeared immediately after EUTS in all patients, and they showed no symptoms of a circulatory condition following the procedure. On the 123I-MIBG imaging studies, the early H/M ratio before EUTS was 2.35 ± 0.26 and postoperatively it was 2.29 ± 0.23. The delayed H/M ratio before EUTS was 2.59 ± 0.3 and after the procedure it was 2.66 ± 0.27. There was no significant difference between the H/M ratio before and after EUTS. The washout rate after EUTS (14.27 ± 4.71%) was significantly lower than that measured before EUTS (18.36 ± 5.13%; p < 0.01). No apparent local defects of accumulation of MIBG were found on SPECT images obtained post-EUTS.

Conclusions. Endoscopic upper thoracic sympathectomy is a minimally invasive procedure; no local denervation was found after EUTS. Findings on 123I-MIBG imaging studies indicate that EUTS suppresses the activation of the sympathetic nervous system slightly, similar to beta-blocker therapy.

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Koshi Ninomiya, Koichi Iwatsuki, Yu-ichiro Ohnishi, Toshika Ohkawa, and Toshiki Yoshimine

OBJECT

The intranasal delivery of bone marrow stromal cells (BMSCs) or mesenchymal stem cells to the injured brains of rodents has been previously reported. In this study, the authors investigated whether BMSCs migrate to spinal cord lesions through an intranasal route and whether the administration affected functional recovery.

METHODS

Forty Sprague-Dawley rats that were subjected to spinal cord injuries at the T7–8 level were divided into 5 groups (injured + intranasal BMSC–treated group, injured + intrathecal BMSC–treated group, injured-only group, injured + intranasal vehicle–treated group, and injured + intrathecal vehicle–treated group). The Basso-Beattie-Bresnahan (BBB) scale was used to assess hind limb motor functional recovery for 2 or 4 weeks. Intralesionally migrated BMSCs were examined histologically and counted at 2 and 4 weeks. To evaluate the neuroprotective and trophic effects of BMSCs, the relative volume of the lesion cavity was measured at 4 weeks. In addition, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) levels in the CSF were evaluated at 2 weeks.

RESULTS

Intranasally administered BMSCs were confirmed within spinal cord sections at both 2 and 4 weeks. The highest number, which was detected in the intrathecal BMSC–treated group at 2 weeks, was significantly higher than that in all the other groups. The BBB score of the intranasal BMSC–treated group showed statistically significant improvements by 1 week compared with the control group. However, in the final BBB scores, there was a statistically significant difference only between the intrathecal BMSC–treated group and the control group. The cavity ratios in the BMSC-treated groups were smaller than those of the control groups, but the authors did not find any significant differences in the NGF and BDNF levels in the CSF among the treatment and control groups.

CONCLUSIONS

BMSCs reached the injured spinal cord through the intranasal route and contributed to the recovery of hind limb motor function and lesion cavity reduction. However, the effects were not as significant as those seen in the intrathecal BMSC–treated group.

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Toru Hayakawa, Kazuyoshi Morimoto, Yukitaka Ushio, Takesada Mori, Toshiki Yoshimine, Akio Myoga, and Heitaro Mogami

✓ Levels of astroprotein (an astrocyte-specific protein found in the cerebrum) were measured by radioimmunoassay in the cerebrospinal fluid (CSF) of 120 patients with intracranial diseases and eight control subjects. The astroprotein level was elevated (above 25 ng/ml) in 13 of 30 cases (43.3%) of glial tumors, nine of 57 cases (15.8%) of nongliomatous intracranial tumors, seven of 33 cases (21.2%) of non-neoplastic intracranial diseases, but in none of the eight control cases. In glioblastoma patients, CSF astroprotein was elevated in eight of 12 cases (66.7%), in three of them to a remarkable degree (above 500 ng/ml). The possible role of this test is briefly discussed, and the mechanism of increase of the astroprotein levels in the CSF considered.

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Naoki Tani, Youichi Saitoh, Masayuki Hirata, Amami Kato, and Toshiki Yoshimine

✓ The relief of intractable pain after spinal cord injury (SCI) is very difficult to obtain, even with dorsal root entry zone lesioning, spinal cord stimulation, and thalamic stimulation. Using bilateral motor cortex stimulation (MCS) the authors successfully treated a woman who experienced deafferentation pain 4 years after sustaining an SCI. To the authors' knowledge, this is the first report of bilateral MCS for pain relief after SCI. The success they achieved using this method indicates that MCS could be a new treatment option for deafferentation pain following SCI.