Complete mitochondrial and chloroplast DNA sequences of the freshwater green microalga Medakamo hakoo.

We report the complete organellar genome sequences of an ultrasmall green alga, Medakamo hakoo strain M-hakoo 311, which has the smallest known nuclear genome in freshwater green algae. Medakamo hakoo has 90.8-kb chloroplast and 36.5-kb mitochondrial genomes containing 80 and 33 putative protein-coding genes, respectively. The mitochondrial genome is the smallest in the Trebouxiophyceae algae studied so far. The GC content of the nuclear genome is 73%, but those of chloroplast and mitochondrial genomes are 41% and 35%, respectively. Codon usages in the organellar genomes have a different tendency from that in the nuclear genome. The organellar genomes have unique characteristics, such as the biased encoding of mitochondrial genes on a single strand and the absence of operon structures in chloroplast ribosomal genes. Medakamo hakoo will be helpful for understanding the evolution of the organellar genome and the regulation of gene expression in chloroplasts and mitochondria.

Genomic analysis of an ultrasmall freshwater green alga, Medakamo hakoo.

Ultrasmall algae have attracted the attention of biologists investigating the basic mechanisms underlying living systems. Their potential as effective organisms for producing useful substances is also of interest in bioindustry. Although genomic information is indispensable for elucidating metabolism and promoting molecular breeding, many ultrasmall algae remain genetically uncharacterized. Here, we present the nuclear genome sequence of an ultrasmall green alga of freshwater habitats, Medakamo hakoo. Evolutionary analyses suggest that this species belongs to a new genus within the class Trebouxiophyceae. Sequencing analyses revealed that its genome, comprising 15.8 Mbp and 7629 genes, is among the smallest known genomes in the Viridiplantae. Its genome has relatively few genes associated with genetic information processing, basal transcription factors, and RNA transport. Comparative analyses revealed that 1263 orthogroups were shared among 15 ultrasmall algae from distinct phylogenetic lineages. The shared gene sets will enable identification of genes essential for algal metabolism and cellular functions.

Cyanidioschyzon merolae aurora kinase phosphorylates evolutionarily conserved sites on its target to regulate mitochondrial division.

The mitochondrion is an organelle that was derived from an endosymbiosis. Although regulation of mitochondrial growth by the host cell is necessary for the maintenance of mitochondria, it is unclear how this regulatory mechanism was acquired. To address this, we studied the primitive unicellular red alga Cyanidioschyzon merolae, which has the simplest eukaryotic genome and a single mitochondrion. Here we show that the C. merolae Aurora kinase ortholog CmAUR regulates mitochondrial division through phosphorylation of mitochondrial division ring components. One of the components, the Drp1 ortholog CmDnm1, has at least four sites phosphorylated by CmAUR. Depletion of the phosphorylation site conserved among eukaryotes induced defects such as mitochondrial distribution on one side of the cell. Taken together with the observation that human Aurora kinase phosphorylates Drp1 in vitro, we suggest that the phosphoregulation is conserved from the simplest eukaryotes to mammals, and was acquired at the primitive stage of endosymbiosis.

[Laparoscopic Gastrectomy for Gastric Adenocarcinoma of the Fundic Gland Type - Report of a Case].

A 69-year-old man underwent esophagogastroduodenoscopy, which showed a slightly depressed lesion at the greater curvature of the gastric body. We diagnosed gastric adenocarcinoma of the fundic gland type(GA-FG)from examination of the biopsy specimen. Endoscopic submucosal dissection(ESD)was performed for curative resection. The pathological examination revealed a positive vertical margin. Consequently, laparoscopic gastrectomy was additionally performed. GA-FG has recently been proposed as a new entity of gastric adenocarcinoma. GA-FG mostly develops without Helicobacter pylori infection and often invades the submucosa, regardless of size. However, GA-FG rarely demonstrates lymphatic and venous invasion despite deep submucosal invasion. Since most GA-FG cases undergo ESD, few reports of surgical resection exist. Here, we report our experience of laparoscopic gastrectomy for GA-FG.

Cerebral hemodynamic benefits after carotid artery stenting in patients with near occlusion.

OBJECTIVE: The natural history and management of patients with near occlusion (NO) of the internal carotid artery are controversial. In particular, it is unclear whether cerebral hemodynamics are compromised in these patients and whether improvement by carotid revascularization leads to the prevention of ischemic stroke. In this study, we measured cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) using single-photon emission computed tomography before and after carotid artery stenting (CAS) for NO to examine the effectiveness of CAS from the perspective of cerebral hemodynamics. METHODS: CAS was performed in 15 patients with NO and in 78 with severe stenosis (≥70%) but without NO at our institution. Resting CBF and CVR to acetazolamide were measured using N-isopropyl-p-[I-123] iodoamphetamine single-photon emission computed tomography before and at 3 to 6 months after CAS. We also measured CBF using the same method for healthy individuals and compared the results among the three groups. RESULTS: CAS was successfully performed in all patients. Before CAS, the mean resting CBF was 26.68 ± 4.23 mL/100 g/min, and the mean CVR was -0.8% ± 15.1% in the patients with NO, both of which were significantly lower than in patients with severe stenosis without NO and in healthy individuals. After CAS, the mean resting CBF and mean CVR in patients with NO increased significantly to 30.07 ± 5.67 mL/100 g/min and 37.0% ± 21.4%, respectively, and there were no significant differences among the three groups. CONCLUSIONS: Before CAS, patients with NO were more hemodynamically compromised than those with severe stenosis without NO. After CAS, significant cerebral hemodynamic improvement and normalization occurred long-term. Thus, from a hemodynamic perspective, CAS was effective in patients with NO.

The kinesin-like protein TOP promotes Aurora localisation and induces mitochondrial, chloroplast and nuclear division.

The cell cycle usually refers to the mitotic cycle, but the cell-division cycle in the plant kingdom consists of not only nuclear but also mitochondrial and chloroplast division cycle. However, an integrated control system that initiates division of the three organelles has not been found. We report that a novel C-terminal kinesin-like protein, three-organelle division-inducing protein (TOP), controls nuclear, mitochondrial and chloroplast divisions in the red alga Cyanidioschyzon merolae. A proteomics study revealed that TOP is a member of a complex of mitochondrial-dividing (MD) and plastid-dividing (PD) machineries (MD/PD machinery complex) just prior to constriction. After TOP localizes at the MD/PD machinery complex, mitochondrial and chloroplast divisions occur and the components of the MD/PD machinery complexes are phosphorylated. Furthermore, we found that TOP downregulation impaired both mitochondrial and chloroplast divisions. MD/PD machinery complexes were formed normally at each division site but they were neither phosphorylated nor constricted in these cells. Immunofluorescence signals of Aurora kinase (AUR) were localized around the MD machinery before constriction, whereas AUR was dispersed in the cytosol by TOP downregulation, suggesting that AUR is required for the constriction. Taken together our results suggest that TOP induces phosphorylation of MD/PD machinery components to accomplish mitochondrial and chloroplast divisions prior to nuclear division, by relocalization of AUR. In addition, given the presence of TOP homologs throughout the eukaryotes, and the involvement of TOP in mitochondrial and chloroplast division may illuminate the original function of C-terminal kinesin-like proteins.

Cognitive outcome differences on the side of carotid artery stenting.

OBJECTIVE: The right and left sides of the brain play different roles in cognition. Therefore, the side of treatment should be taken into consideration when evaluating cognitive outcome following revascularization. Thus, we designed a study to evaluate changes in right hemisphere cognitive function in patients undergoing right carotid artery stentings (CAS) and left hemispheric cognitive function in patients undergoing left CAS. In addition, we studied CAS-related changes in regional cerebral blood flow to determine potential correlations with changes in cognitive function. METHODS: We performed a prospective assessment of 39 CAS patients, all of whom were right-handed. Patients with contralateral stenotic lesions were excluded. Twenty-one patients underwent CAS of the right internal carotid artery (Right CAS group) and 18 underwent CAS of the left internal carotid artery (Left CAS group). Neuropsychological testing was performed preoperatively and 6 months after endovascular treatment. Cerebral blood flow was determined by 123I-labeled N-isopropyl-p-iodoamphetamine single-photon emission computed tomography before and 6 months after CAS. RESULTS: In the Right CAS group, postoperative performance intelligence quotient score (91.1±18.2) was significantly improved compared with the preoperative score (84.9±16.7; P<.001). In the Left CAS group, postoperative verbal intelligence quotient score (104.0±18.8) was significantly higher than that before endovascular treatment (97.9±15.8; P<.005). Postoperative regional cerebral blood flow was not significantly different from that before endovascular treatment in either group. However, regional cerebrovascular reactivity of the treated side showed significant improvement after treatment. CONCLUSIONS: Amelioration of cognitive function may be dependent on the side of revascularization. Performance intelligence quotient improved after CAS in patients with severe carotid artery stenosis on the right side. Verbal intelligence quotient also improved on the left side after endovascular treatment. These effects seemed to involve improvement in regional cerebrovascular reactivity by CAS.

Progression of stenosis into occlusion of the distal posterior cerebral artery supplying an occipital arteriovenous malformation manifesting as multiple ischemic attacks: case report.

A 31-year-old healthy male presented with a rare case of cerebral arteriovenous malformation (AVM) manifesting as repeated ischemic attacks and cerebral infarction causing left sensori-motor disturbance. Neuroimaging revealed cerebral infarction in the right thalamus as well as right occipital AVM without bleeding. The AVM was mainly fed by the right angular artery, and the right posterior cerebral artery (PCA) showed mild stenosis and segmental dilation at the P(2)-P(3) portion. After referral to our hospital, transient ischemic attacks causing left homonymous hemianopsia, and left arm and leg numbness were frequently recognized. Additional imaging revealed a new ischemic lesion in the occipital lobe, and repeated cerebral angiography showed right PCA occlusion at the P(2)-P(3) segment. Cerebral AVM presenting with cerebral infarction due to occlusion of feeding arteries is rare. In our case, intimal injury due to increased blood flow or spontaneous dissection of the artery were possible causes. We should monitor any changes in the architecture and rheology of the feeding vessels during the clinical course to prevent ischemic complications.

External carotid artery stenting and superficial temporal artery to middle cerebral artery anastomosis for internal carotid artery occlusion with external carotid artery severe stenosis: case report.

Superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis may have inadequate effects in patients with internal carotid artery (ICA) occlusion and severe stenosis of the ipsilateral external carotid artery (ECA), because poor blood flow in the STA leads to insufficient flow to the MCA. In these patients, dilation of the stenotic ECA is required to improve the blood flow in the STA before STA-MCA anastomosis. A 71-year-old man presented with left hemiparesis and dysarthria. Magnetic resonance imaging revealed an old watershed infarction in the right cerebral hemisphere. Right carotid angiography showed right ICA occlusion and severe ipsilateral ECA stenosis. Single photon emission computed tomography (SPECT) demonstrated severe hemodynamic insufficiency in the right MCA territory. Instead of endarterectomy of the ECA, angioplasty and stenting (CAS) for ECA was performed to ensure adequate blood flow in the STA, due to the history of myocardial infarction and bifurcation of the common carotid artery at a high level (C2 level). Then STA-MCA anastomosis was performed 1 month later. Postoperative SPECT demonstrated marked improvement of hemodynamic insufficiency in the right MCA territory. After treatment, the patient had no ischemic events. This case suggests external CAS together with STA-MCA anastomosis is a good therapeutic option for a patient with symptomatic ICA occlusion and severe stenosis of the ipsilateral ECA if external CEA is difficult to perform.

Intra-operative monitoring of lower extremity motor-evoked potentials by direct cortical stimulation.

OBJECTIVE: Motor-evoked potentials (MEPs) are commonly recorded from upper-extremity muscles, whereas lower-extremity MEP (LE-MEP) monitoring has not been adequately established. The goal of the study was to develop a MEP monitoring method using direct cortical stimulation (DCS) for predicting motor deficits of lower extremities. METHODS: Intra-operative LE-MEP monitoring was performed in 22 patients. After craniotomy, a subdural electrode was placed on the cortex so that the optimal contact was positioned 2 cm lateral from the midline on the motor cortex. The electrodes for stimulation consisted of a cathode at Fpz and an anode at the optimal contact site on the motor cortex. After stimulation was performed with short trains of five stimuli, LE-MEPs were recorded from the lower-limb muscles. RESULTS: LE-MEPs were consistently recorded in all patients. Disappearance or amplitude reduction of MEP waveforms was observed in five patients, but the MEP waveforms had recovered and remained at the control level by dural closure, and no permanent motor deficit was observed in any patient. CONCLUSIONS: We accomplished LE-MEP recording during supratentorial surgery using monopolar DCS with a subdural electrode placed on the convex side of the motor cortex. SIGNIFICANCE: A useful method of intra-operative LE-MEP recording was described.

Fate of clots in patients with subarachnoid hemorrhage after different surgical treatment modality: a comparison between surgical clipping and Guglielmi detachable coil embolization.

BACKGROUND: Subarachnoid clot is important in the development of delayed vasospasm after subarachnoid hemorrhage (SAH). OBJECTIVE: To compare the clearance of subarachnoid clot and the incidence of symptomatic vasospasm in surgical clipping and embolization with Guglielmi detachable coils for aneurysmal SAH. METHODS: The subjects were 115 patients with Fisher group 3 aneurysmal SAH on computed tomography scan at admission whose aneurysm was treated by surgical clipping (clip group; n = 86) or Guglielmi detachable coil embolization (coil group; n = 29) within 72 hours of ictus. Software-based volumetric quantification of the subarachnoid clot was performed, and the amount of hemoglobin in drained cerebrospinal fluid was measured. RESULTS: Clearance of the subarachnoid clot on the computed tomography scan was rapid in the clip group until the day after the operation but slow in the coil group (58.9% removed vs 27.8% removed; P = .008). However, postoperative clearance of the clot occurred more rapidly in the coil group. Reduction of the clot until days 3 through 5 did not differ significantly between the 2 groups (72.9% removed vs 75.2% removed). The amount of hemoglobin in the clip group was > 0.8 g/d until day 3 and then gradually decreased (n = 15), but hemoglobin in the coil group remained at > 0.8 g/d until day 5 (n = 17). The incidence of symptomatic vasospasm did not differ between the groups. CONCLUSION: Subarachnoid clot can be removed directly during surgical clipping, which is not possible with endovascular treatment. However, the percentage reduction of the clot on days 3 through 5 did not differ between the 2 groups.

Evaluation of small ischemic lesions after carotid artery stenting: the usefulness of thin-slice diffusion-weighted MR imaging.

INTRODUCTION: There has been concern regarding the usefulness of diffusion-weighted imaging (DWI) to evaluate the ischemic lesions associated with carotid artery stent placement (CAS). Some small lesions may be detected not by standard DWI but by thin-slice DWI alone, since most of the cerebral lesions are very small in size and clinically silent. The purpose of this study is to compare the detectability of the small ischemic lesions after CAS by standard and thin-slice DWI. METHODS: Both standard DWI with slice thickness of 6 mm and thin-slice DWI with slice thickness of 2 mm were obtained at the same MR examination within 2 to 7 days after 20 procedures of CAS in 17 patients. Number and measured diameter size of the detected lesions on both DWI were compared. RESULTS: All CAS procedures in 17 patients were successfully completed. The focal ischemic lesions were detected in 14 of 20 on thin-slice DWI and seven examinations on standard DWI. The total numbers of hyperintense lesions were 31 on thin-slice DWI and ten on standard DWI (p < 0.001). The sizes of these ten lesions on thin-slice DWI were larger than those of standard DWI, and the mean size of the thin-slice DWI and that of standard DWI were significantly different (p < 0.005). CONCLUSION: Thin-slice DWI was able to detect small cortical lesions better than standard DWI. Thin-slice DWI may be useful to evaluate small silent ischemic lesions after CAS.

Delayed parenchymal hemorrhage following successful embolization of brainstem arteriovenous malformation. Case report.

A 64-year-old man presented with subarachnoid hemorrhage from a small brainstem arteriovenous malformation (AVM). Cerebral angiography showed a small AVM in the lateral midbrain, which was fed by a basilar perforating artery, and drained into the right transverse pontine vein and superior petrous vein. Endovascular embolization in the acute stage was selected to occlude the arteriovenous shunt and provide additional intensive treatment for cerebral spasm with lower risk of rebleeding. The AVM was occluded by embolization using n-butyl cyanoacrylate. Intraparenchymal hemorrhage in the ipsilateral pons was detected 1 month after treatment. The causes of the hemorrhage remain unclear.

Preoperative prediction of outcome in 283 poor-grade patients with subarachnoid hemorrhage: a project of the Chugoku-Shikoku Division of the Japan Neurosurgical Society.

BACKGROUND: The management of patients with poor-grade subarachnoid hemorrhage (SAH) continues to be controversial. The objective of this study was to examine predictors of outcome of poor-grade SAH after surgical obliteration of the aneurysm. METHODS: The study was performed as a retrospective review of 283 patients with poor-grade SAH who underwent surgical obliteration of the aneurysm at multiple centers in Chugoku and Shikoku, Japan. RESULTS: A favorable outcome at discharge was achieved in 97 of the 283 patients (34.3%). Age (p < 0.001), World Federation of Neurosurgical Societies (WFNS) grade V at admission (p = 0.002), improvement in WFNS grade after admission (p = 0.002), Fisher grade (p = 0.039) and a low-density area (LDA) associated with vasospasm on computed tomography (CT; p < 0.001) showed a significant association with outcome. Further analysis of WFNS grades indicated that most patients who only improved to preoperative grade IV from grade V at admission did not have a favorable outcome. Multivariate analysis identified age (especially of > or =65 years; p < 0.001), WFNS grade V (p < 0.001) and LDA associated with vasospasm on CT (p < 0.001) as predictors of a poor outcome, and improvement in WFNS grade (p = 0.001) as a predictor of a favorable outcome after surgical obliteration of the aneurysm. CONCLUSIONS: Advanced age, WFNS grade V, improvement in WFNS grade, and LDA associated with vasospasm on CT were found to be independent predictors of clinical outcome, whereas rebleeding, early aneurysm surgery and treatment modality (surgical clipping or Guglielmi detachable coil embolization) were not independently associated with outcome in patients with poor-grade aneurysm.

Operative open intra-aneurysmal thrombectomy for ruptured cerebral aneurysm and peripheral ischemia associated with vasospasm.

The endovascular approach has become the standard treatment for ruptured aneurysms during the vasospasm risk period following subarachnoid hemorrhage; however, it may be disadvantageous under certain conditions. We report a patient with a ruptured middle cerebral artery aneurysm with severe vasospasm and thrombosis within the aneurysm immediately after angiography. Emergent operative open thrombectomy of the intra-aneurysmal thrombus restored blood flow to the ischemic penumbra territory demonstrated by single photon emission CT scan and diffusion-weighted MRI.

Vaccine therapy with dendritic cells transfected with Il13ra2 mRNA for glioma in mice.

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.

Continuous hypertension and tachycardia after resection of a hemangioblastoma behind the dorsal medulla oblongata: relationship to sympathetic overactivity at the neurogenic vasomotor center.

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.

Elevated concentrations of sphingosylphosphorylcholine in cerebrospinal fluid after subarachnoid hemorrhage: a possible role as a spasmogen.

This study investigates the role of sphingosylphosphorylcholine (SPC) in the mechanisms underlying cerebral vasospasm after subarachnoid hemorrhage (SAH). The levels of SPC were measured in cerebrospinal fluid (CSF) of patients with SAH and also in an experimental canine model. CSF samples were collected from 11 patients with SAH, and from dogs that had received an injection of SPC into the cisterna magna to examine SPC kinetics in the CSF. SPC was assayed using solid-phase extraction and triple quadrupole mass spectrometry. The SPC concentrations in SAH patients on days 3, 8, and 14 after the onset of SAH were significantly higher than those in normal CSF. In the canine model, rapid dilution of SPC in CSF was observed. In combination with data from previous studies, these results suggest that SPC is involved in the development of cerebral vasospasm. Rapid dilution of SPC in CSF suggests that SPC is released into CSF at higher concentrations than those measured in the present study.

Cerebrovascular moyamoya disease in a 5-year-old girl who underwent interruption of the right common carotid artery in the neonatal period.

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.

The influence of focal brain cooling on neurophysiopathology: validation for clinical application.

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 x 6 x 2 mm) was used as a cooling device and was placed on the surface of the sensorimotor cortex after a 10 x 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 degrees 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 degrees 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 degrees 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 degrees C did not induce any irreversible histological change or motor dysfunction. These results suggest that focal brain cooling above 0 degrees 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.