Ischemia-induced neuronal cell death is mediated by the endoplasmic reticulum stress pathway involving CHOP.

Brain ischemia induces apoptosis in neuronal cells, but the mechanism is not well understood. When wild-type mice were subjected to bilateral common carotid arteries occlusion (BCCAO) for 15 min, apoptosis-associated morphological changes and appearance of TUNEL-positive cells were observed in the striatum and in the hippocampus at 48 h after occlusion. RT-PCR analysis revealed that mRNAs for ER stress-associated proapoptotic factor CHOP and an ER chaperone BiP are markedly induced at 12 h after BCCAO. Immunohistochemical analysis showed that CHOP protein is induced in nuclei of damaged neurons at 24 h after occlusion. In contrast, ischemia-associated apoptotic loss of neurons was decreased in CHOP(-/-) mice. Primary hippocampal neurons from CHOP(-/-) mice were more resistant to hypoxia-reoxygenation-induced apoptosis than those from wild-type animals. These results indicate that ischemia-induced neuronal cell death is mediated by the ER stress pathway involving CHOP induction.

A nonadhesive liquid embolic agent of ethylene vinyl alcohol copolymer and ethanol mixture for cerebral arteriovenous malformations. Clinical experience.

SUMMARY: We report our experience using our new nonadhesive liquid embolic agent, an ethylene vinyl alcohol copolymer (EVAL)/Ethanol mixture, to treat human arteriovenous malformations (AVM). Between June 1995 and April 2001, 57 patients with confirmed AVM underwent embolization with the EVAL/Ethanol mixture. Using 87 procedures consisting of one to three stages, we embolized 185 feeding arteries to occlude as much of the AVM as possible. Repeated injections under fluoroscopic control could be performed smoothly without encountering cementing of the catheter in the vessel wall. Among 87 procedures undertaken in 57 patients, seven (8.0%) procedures in six patients produced new postembolization symptoms. Resolution of these symptoms occurred within hours or days following four of the seven procedures; permanent neurological deficits remained after three embolization procedures (3.4%). Of the 57 patients, three underwent postembolization radiosurgery, 54 were radically treated with microsurgical extirpation. Histopathological examinations of the 54 specimens disclosed mild inflammation within the embolized lumen without inflammatory reactions in the media or adventitia. Follow-up angiograms obtained three years after they underwent radiosurgery showed that in all three patients the nidus had completely disappeared. The EVAL/Ethanol mixture is handled easily and appears to be an effective and safe embolic agent for the preoperative embolization of AVM.

Brain stem venous congestion due to dural arteriovenous fistulas of the cavernous sinus.

BACKGROUND: Venous congestion of the brain stem due to dural arteriovenous fistulas (DAVFs) in the cavernous sinus is rare and presents therapeutic challenges. To assess the prognosis of patients with symptomatic DAVFs and brain stem dysfunction, we evaluated the degree of venous ischemia by examining pre- and post-treatment magnetic resonance images (MRI) in 2 patients presenting with venous congestion of the brain stem. METHODS: A 56-year-old woman with left hemiparesis and a 70-year-old woman with gait disturbance attributable to right cavernous sinus DAVFs were referred to our hospital. In both cases, T2-weighted magnetic resonance imaging (MRI) disclosed a hyperintensity lesion in the brainstem due to venous congestion. FINDINGS: Both patients underwent open surgery for direct embolization of the cavernous sinus because there were no approach routes for transvenous embolization. The patient whose pretreatment MRI demonstrated Gd enhancement continued to manifest neurological deficits and persistence of the abnormal hyperintensity on post-treatment T2-weighted MRI. In the other patient whose pretreatment MRI showed no Gd enhancement, treatment produced a complete response of her neurological deficit and disappearance of the abnormal hyperintensity area. CONCLUSIONS: We tentatively conclude that lesions corresponding to hyperintensity areas on non-Gd-enhanced, T2-weighted MRI may reflect a reversible condition whereas lesions identified as hyperintense areas on GD-enhanced T2-weighted MRI may be indicative of irreversibility.

Successful treatment by spinal cord stimulation for gait disturbance in a patient with diffuse axonal injury.

The authors present a case of diffuse axonal injury (DAI) treated by cervical spinal cord stimulation (C-SCS) for gait disturbance. The patient had right hemiparesis of moderate degree, mild ataxia, ideational apraxia and gait disturbance, when admitted to our hospital for rehabilitation. He could not walk by himself, nevertheless neurorehabilitation was done for four months. Xenon-CT was examined by C-SCS loading and the changes of regional cerebral blood flow were significantly increased in both hemispheres, especially in the thalamus. C-SCS was performed continuously on condition of 25 Hz, 200 microsec and 0.5 V, daily for a month. Neurological deficits, especially gait disturbance due to ideational apraxia, were gradually improved after initiation of C-SCS, and the patient could walk by himself. We speculate that C-SCS played a role in triggering improvement of gait disturbance at the chronic stage in our case, and SCS may be helpful for neurorehabilitation of focal symptoms after DAI.

The neuroprotective effect of a novel calmodulin antagonist, 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate, in transient forebrain ischemia.

A novel calmodulin (CaM) antagonist DY-9760e, (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate), with an apparent neuroprotective effect in vivo, potently inhibits CaM-dependent nitric oxide synthase in situ. In the present study, we determined whether DY-9760e inhibits nitric oxide (NO) production and protein nitration by peroxynitrite (ONOO(-)) formation in the hippocampal CA1 region of gerbils after transient forebrain ischemia. In freely moving gerbils, NO production after 10-minute forebrain ischemia was monitored consecutively with in vivo brain microdialysis. Pretreatment with DY-9760e (50 mg/kg i.p.) significantly decreased the increased levels of NO(x)(-) (NO metabolites, NO(2)(-) plus NO(3)(-)) immediately after, 24 h after cerebral ischemia-reperfusion to the control levels of sham-operated animals. Western blot and immunohistochemical analyses using an anti-nitrotyrosine antibody as a marker of ONOO(-) formation indicated a marked increase in nitrotyrosine immunoreactivity in the pyramidal neurons of the CA1 region 2 h after reperfusion, and DY-9760e significantly inhibited increased nitrotyrosine immunoreactivity. Coincident with the inhibition of the NO production and protein tyrosine nitration, pretreatment with DY-9760e rescued the delayed neuronal death in the hippocampal CA1 region. These results suggest that the inhibitory effects of DY-9760e on the NO-ONOO(-) pathway partly account for its neuroprotective effects in cerebral ischemia.

Endovascular coil trapping for ruptured vertebral artery dissecting aneurysms by using double microcatheters technique in the acute stage.

BACKGROUND: In the treatment of vertebral artery (VA) dissecting aneurysms, only proximal occlusion of the VA does not necessarily prevent rerupture. We evaluated the efficacy of coil trapping for the ruptured VA dissecting aneurysms using the double microcatheters technique. METHODS: We treated 11 patients who presented with subarachnoid haemorrhage (SAH) due to rupture of a VA dissecting aneurysm which did not involve the posterior inferior cerebellar artery at the site of dissection. All patients tolerated the balloon occlusion test. Within 3 days of the SAH, the dissection site was trapped with a Guglielmi detachable coil (GDC) using the double microcatheters technique. The proximal and distal sites of the dissecting aneurysm were embolized simultaneously. FINDINGS: GDC trapping at the affected site was successful in all 11 patients. Radiographic findings showed complete occlusion of the dissection site and patency of the unaffected artery. Although one patient experienced transient dysphagia, there were no major complications. INTERPRETATION: The double microcatheters technique is effective for coil trapping of ruptured VA dissecting aneurysms in selected patients. The risks posed by this simple technique are minimal, even in the acute stage.

Nontraumatic spinal subdural haematoma occurring in a postpartum period.

Spontaneous occurrence of spinal subdural haematoma (SSH) is very rare. While many neurological disorders can develop in pregnant patients in relation to haemostatic imbalance, there have been no reports in the literature suggesting that pregnancy and/or childbirth per se could be a single risk factor for acute SSH.A 38-year-old previously healthy woman gave birth to a baby via transvaginal normal delivery. The patient had no history of receiving anticoagulants. Eight days after delivery, she experienced sudden onset severe interscapular back pain, and the next day she developed dysesthesia in the both legs and mild urinary retention. Severe meningeal signs were noted. Lumbar puncture revealed bloody cerebrospinal fluid. Magnetic resonance images revealed SSH in the ventral position spreading from levels Th1 to Th7. The patient underwent conservative treatment after which the symptoms gradually improved. Serial MRI study at 17 and 69 days after onset showed spontaneous regression of the SSH. Spinal angiography did not show any vascular malformations, but simultaneous cerebral angiography revealed a co-existing cerebral aneurysm on the C2 segment of the left internal carotid artery. It is unlikely that the cerebral aneurysm was the origin of the SSH, based on the clinical and radiographic findings. Moreover, we confirmed the unruptured nature of the aneurysm during the clipping procedure at open surgery. We report the unique case of subacute SSH occurring 8 days after childbirth without other known risk factors. The possible etiology and magnetic resonance imaging (MRI) findings in this case, and the current controversy concerning therapy for SSH are discussed.

Expression of lymphocyte-specific chemokines in human malignant glioma: Essential role of LARC in cellular immunity of malignant glioma.

Lymphocytes are frequently observed in human malignant glioma, the mechanism(s) underlying their appearance is not fully understood. To clarify tumor immunity in malignant gliomas, we analyzed the expression of 8 novel lymphocyte-specific chemokines in human glioma cell lines and glioma tissues by RT-PCR, Northern blot, immunoblot and immunohistochemistry, and examined the correlation with the infiltration of various subsets of lymphocytes. For the 8 chemokines examined (LARC, TARC, ELC, SLC, PARC, LEC, HCC-2, and SCM-1alpha), expression of LARC was clearly detectable in all 12 glioma cell lines by RT-PCR. Additionally, expression of TARC and SCM-1alpha was detectable in the majority of glioma cell lines. However, the expression level of most chemokines was low, so that Northern blot analysis could not demonstrate their expression with the exception of LARC in 2 cell lines. Expression of LARC mRNA and LARC protein was strongly induced by phorbol myristate ester in U87 MG cells. The production of LARC protein was demonstrated in 4 of 8 glioblastoma tissues by immunoblotting, and 9 of 33 samples (27.3%) by immunohistochemistry. Interestingly, the positivity of LARC staining was significantly correlated with the infiltration of CD8-, CD4-, and CD45R0-positive cells (p<0.001). Although the constitutive expression level of LARC is low, certain stimulations could strongly induce its expression, and play a crucial role in the tumor immunity of human malignant glioma.

Cerebral gliomas: prospective comparison of multivoxel 2D chemical-shift imaging proton MR spectroscopy, echoplanar perfusion and diffusion-weighted MRI.

Developments in MRI have made it possible to use diffusion-weighted MRI, perfusion MRI and proton MR spectroscopy (MRS) to study lesions in the brain. We evaluated whether these techniques provide useful, complementary information for grading gliomas, in comparison with conventional MRI. We studied 17 patients with histologically verified gliomas, adding multivoxel proton MRS, echoplanar diffusion and perfusion MRI the a routine MRI examination. The maximum relative cerebral blood volume (CBV), minimum apparent diffusion coefficient (ADC) and metabolic peak area ratios in proton MRS were calculated in solid parts of tumours on the same slice from each imaging data set. The mean minimum ADC of the 13 high-grade gliomas (0.92+/-0.27 x 10(-3) mm(2)/s) was lower than that of the four low-grade gliomas (1.28+/-0.15 x 10(-3) mm(2)/s) ( P<0.05). Means of maximum choline (Cho)/N-acetylaspartate (NAA), Cho/creatine (Cr), Cho/Cr in normal brain (Cr-n) and minimum NAA/Cr ratios were 5.90+/-2.62, 4.73+/-2.22, 2.66+/-0.68 and 0.40+/-0.06, respectively, in the high-grade gliomas, and 1.65+/-1.37, 1.84+/-1.20, 1.61+/-1.29 and 1.65+/-1.61, respectively, in the low-grade gliomas. Significant differences were found on spectroscopy between the high- and low-grade gliomas ( P<0.05). Mean maximum relative CBV in the high-grade gliomas (6.10+/-3.98) was higher than in the low-grade gliomas (1.74+/-0.57) ( P<0.05). Echoplanar diffusion, perfusion MRI and multivoxel proton MRS can offer diagnostic information, not available with conventional MRI, in the assessment of glioma grade.

MRI of intracranial germ-cell tumours.

Our aim was to review the MRI appearances of primary intracranial germ-cell tumours (GCT). We reviewed the MRI studies of 32 patients: 19 with germinomas, five with teratomas, one with an embryonal carcinoma, five with mixed and two with malignant nongerminomatous GCT. Eleven were in the pineal region, 12 suprasellar, five in the both sites, two in the basal ganglia and two in the corpus callosum. Contrast-enhanced images were available for 27 patients. The solid parts of GCT were nearly isointense with grey matter on both T1- and T2-weighted images. In seven patients with nongerminomatous GCT high-signal components were found on T1-weighted images, representing haemorrhage, high-protein fluid or fat. Cystic components were detected in 17 of 27 patients; eight germinomas and all nine nongerminomatous GCT had cysts. The solid components of germinomas enhanced homogeneously in eight cases and heterogeneously in 10, while all nongerminomatous GCT showed heterogeneous enhancement. MRI features tumours can facilitate correct diagnosis of GCT, including histological subtypes.

Management outcome for ruptured anterior circulation aneurysms with a Hunt and Hess clinical grade of III in patients in the 9th decade of life.

BACKGROUND: This study was conducted to define general guidelines for rational clinical decision-making with respect to patients older than 80 years who present with ruptured anterior circulation aneurysms and a Hunt and Hess clinical grade of III. METHODS: The 29 consecutive patients enrolled in this study were treated at 4 participating centers between 1995 and 1998. All were 80 years or older on admission and met 7 eligibility criteria. The decision to treat surgically or non-surgically was made individually at each center. The outcome at discharge was assessed using the Glasgow Outcome Scale (GOS); the Barthel Score (BS) was used to determine the patients' quality of life after discharge. RESULTS: Of 15 surgically treated patients, 4 died before discharge and 8 were discharged in poor condition. Of these, 7 died of unrelated causes within 2 years of the SAH and one is living in a nursing home. Three patients with middle cerebral artery (MCA) aneurysms made a good recovery; they are currently living at home. Of the 14 conservatively treated patients, 10 died during their hospital stay mainly because of rebleeding that occurred within 3 weeks of the subarachnoid hemorrhage (SAH). Three others who were discharged in poor condition died of systemic illness within 2 years. The remaining patient is living in a nursing home with a BS value of 0. CONCLUSIONS: The outcomes for patients treated conservatively were catastrophic. Even in surgically treated patients, favorable outcomes were rare; the best results were achieved in surgically treated patients with MCA aneurysms.

Neuroprotective effect of sodium orthovanadate on delayed neuronal death after transient forebrain ischemia in gerbil hippocampus.

In transient forebrain ischemia, sodium orthovanadate as well as insulinlike growth factor-1 (IGF-1) rescued cells from delayed neuronal death in the hippocampal CA1 region. Adult Mongolian gerbils were subjected to 5-minute forebrain ischemia. Immunoblotting analysis with anti-phospho-Akt/PKB (Akt) antibody showed that phosphorylation of Akt at serine-473 (Akt-Ser-473) in the CA1 region decreased immediately after reperfusion, and in turn transiently increased 6 hours after reperfusion. The decreased phosphorylation of Akt-Ser-473 was not observed in the CA3 region. The authors then tested effects of intraventricular injection of orthovanadate and IGF-1, which are known to activate Akt. Treatment with orthovanadate or IGF-1 30 minutes before ischemia blocked delayed neuronal death in the CA1 region. The neuroprotective effects of orthovanadate and IGF-1 were associated with preventing decreased Akt-Ser-473 phosphorylation in the CA1 region observed immediately after reperfusion. Immunohistochemical studies with the anti-phospho-Akt-Ser-473 antibody also demonstrated that Akt was predominantly in the nucleus and was moderately activated in the cell bodies and dendrites of pyramidal neurons after orthovanadate treatment. The orthovanadate treatment also prevented the decrease in phosphorylation of mitogen-activated protein kinase (MAPK). Pretreatment with combined blockade of phosphatidylinositol 3-kinase and MAPK pathways totally abolished the orthovanadate-induced neuroprotective effect. These results suggest that the activation of both Akt and MAPK activities underlie the neuroprotective effects of orthovanadate on the delayed neuronal death in the CA1 region after transient forebrain ischemia.

Trends in the incidence of primary intracranial tumors in Kumamoto, Japan.

BACKGROUND: The introduction of modern neuro-imaging techniques, as well as various environmental factors, have been changing the incidence and the proportions of the types of clinically diagnosed intracranial tumors. The aim of this study was to determine recent trends in the occurrence of primary intracranial tumors in the residents of Kumamoto Prefecture, Japan. METHODS: We surveyed 2129 patients who were diagnosed with primary intracranial tumors between 1989 and 1998, with histological diagnosis being obtained in 71% of the patients. RESULTS: Of the 2129 patients, 710 (33.3%) had meningiomas, 390 (18.3%) had pituitary adenomas, 315 (14.8%) had malignant gliomas, and 208 (9.8%) had schwannomas. The overall age-adjusted incidence rates were 10.97/100,000/year (males, 9.70; females, 11.86). One hundred and nine patients (5.1%) were younger than 15 years, and 480 patients (22.5%) were older than 70 years. The most common tumors in children were astrocytomas (37.6%), followed by germ-cell tumors (16.5%) and craniopharyngiomas (11.9%), medulloblastomas (11.0%), and ependymomas (4.6%). Meanwhile, the most common tumors in elderly residents were meningioma (51.7%), followed by malignant glioma (13.7%), pituitary adenoma (11.4%), schwannoma (7.7%), malignant lymphoma (4.6%), and astrocytoma (2.7%). The proportion of asymptomatic tumors increased, from 24.6% in 1989-1994 to 33.0% in 1995-1998; 169 (62.8%) were meningiomas, followed by pituitary adenomas (14.1%).

Analysis of loss of heterozygosity on chromosome 10 in patients with malignant astrocytic tumors: correlation with patient age and survival.

OBJECT: The most frequent genetic abnormality in human malignant gliomas is loss of heterozygosity (LOH) on chromosome 10. Candidate genes on chromosome 10 that are associated with the prognosis of patients with anaplastic astrocytoma (AA) and glioblastoma (GBM) were evaluated. METHODS: The authors used 12 fluorescent microsatellite markers on both arms of chromosome 10 to study LOH in 108 primary astrocytic tumors. The LOH on chromosome 10 was observed in 11 (32%) of 34 AAs and 34 (56%) of 61 GBMs. No LOH was detected in 13 low-grade gliomas. Loss of heterozygosity was not detected in any AA in the seven patients younger than 35 years, but it was discovered in 41% of the patients older than 35 years. The prognostic significance of LOH at each locus was evaluated in 89 patients older than 15 years; 33 (37%) had supratentorial AAs and 56 (63%) had supratentorial GBMs. The Cox proportional hazards model, adjusted for patient age at surgery, the preoperative Karnofsky Performance Scale score, and the extent of surgical resection revealed that LOH on marker D10S209 near the FGFR2 and DMBT1 genes was significantly associated with shorter survival in patients with AA. The LOH on markers D10S215 and D10S541, which contain the PTEN/MMAC1 gene between them, was significantly associated with shorter survival in patients with GBM. CONCLUSIONS: In the present study it is found that LOH on chromosome 10 is an age-dependent event for patients with AAs and that LOH on marker D10S209 near the FGFR2 and DMBT1 loci is a significantly unfavorable prognostic factor. It is also reported that LOH on the PTEN/MMAC1 gene is a significantly unfavorable prognostic factor in patients with GBM.

[Treatment of spontaneous carotid-cavernous fistula by the transvenous approach via the facial and angular route].

We report a case of a patient with a spontaneous carotid-cavernous sinus fistula (CCF) who was successfully treated by the facial vein approach. This 66-year-old female had a 3-month history of right chemosis and exophthalmos. Angiograms showed a spontaneous right CCF with primary drainage via the superior ophthalmic vein. As both inferior petrosal sinuses were hypoplastic, the transvenous approach could not be used to gain access to the right cavernous sinus. With effort, we were able to traverse the sharp angle at the corner of the angular vein and the superior ophthalmic vein with a microcatheter. Thereafter, it was easily navigated into the right cavernous sinus. Successful placement of Guglielmi detachable coils resulted in complete closure of the fistula. When it is difficult to gain access to the cavernous sinus via the inferior petrosal sinus, the facial vein approach is a useful alternative.

Suprasellar hemangioblastoma in a patient with von Hippel-Lindau disease confirmed by germline mutation study: case report and review of the literature.

BACKGROUND: Hemangioblastoma (HBL) in the suprasellar region is extremely rare. CASE DESCRIPTION: A suprasellar mass was found in a 33-year-old woman with retinal HBL and bilateral adrenal pheochromocytomas. The diagnosis of von Hippel-Lindau (VHL) disease was confirmed preoperatively not only by these clinical manifestations but also by germline mutation study. The existence of VHL disease indicated a diagnosis of HBL for the suprasellar mass. The results of our mutation study indicated that this patient had type II VHL disease, suggesting that careful follow-up is essential for the early detection of renal cell carcinoma, which is often associated with type II VHL disease. Here, we summarize the previously reported features of sellar and suprasellar HBLs. CONCLUSIONS: HBLs in this region may be one manifestation of VHL disease. Genetic testing of the VHL gene of our patient could provide useful information to determine appropriate medical care and management.

Humanization and epitope mapping of neutralizing anti-human Fas ligand monoclonal antibodies: structural insights into Fas/Fas ligand interaction.

Fas ligand (L)/CD95L, a proapoptotic member of the TNF family, is a potential target for clinical intervention in various diseases. In the present study, we generated a humanized anti-human FasL mAb and characterized the epitopes of neutralizing mAbs by extensive alanine-scanning mutagenesis of human FasL. The predicted molecular model of FasL trimer revealed that the mAbs recognize largely overlapped conformational epitopes that are composed of two clusters, one around the outer tip-forming D-E loop and another near the top of FasL. Both of these sites on FasL are critically involved in the direct interaction with the corresponding receptor, Fas. These results suggest that the mAbs efficiently neutralize FasL cytotoxicity by masking both of these FasL/Fas contact sites.

Intravenously injected FK506 failed to inhibit hippocampal calcineurin.

FK506 (tacrolimus) is known as an inhibitor for calcineurin and is used in numerous research fields. It is not clear whether intravenously injected FK506 inhibits neuronal calcineurin. We measured the calcineurin activities of normal and postischemic rat hippocampi after intravenous injection of FK506 (3 mg/kg). Intravenously injected FK506 had no inhibitory effect on calcineurin activity in the hippocampi of normal and postischemic rats, whereas FK506 inhibited the calcineurin in vitro (purified enzyme, hippocampal homogenate, and hippocampal slice culture homogenate). Thus, it is considered that intravenously injected FK506 does not act on intraneuronal calcineurin and that several effects of FK506 are not due to the inhibition of neuronal calcineurin.