Kanji Mori

Isolation and expression analysis of a novel human homologue of the Drosophila glial cells missing (gcm) gene

A novel human homologue (GCMB) of the Drosophila glial cells missing gene (dGCM) was isolated using RACE. GCMB contained a gcm motif sequence and a nuclear targeting sequence similar to that of dGCM and mouse GCMb. Homology searches indicated that GCMB was located within chromosome 6p24.2. Transcripts of GCMB were detected by means of RT‐PCR in fetal brain, normal adult kidney, 3/3 medulloblastomas, 1/3 gliomas and 4/8 non‐neuroepithelial tumor cell lines. Our data suggest that humans have two homologues of gcm like mice and that human gcm genes form a novel family which may function not only during fetal development but also in the postnatal or pathological stage.

Anti-proliferative effects of TNP-470 on human malignant gliomain vivo: potent inhibition of tumor angiogenesis

SummaryA novel angiogenesis inhibitor TNP-470 was investigated for its anti-tumor activity against malignant gliomas bothin vitro andin vivo. TNP-470 cytostatically inhibited the growth in all of the seven glioma cell lines in culture including anticancer drug resistant cells. The 50% inhibitory concentrations (IC50) of these glioma cell lines were 10 to 30 Μg/ml and they were 10 to 20 times higher than IC50 of normal endothelial cells. TNP-470 (30 mg/kg, i.p., every other day) also significantly inhibited the tumor growth of T98G-transplanted nude mice. Microscopically, tumor vessels after the treatment of the tumor-bearing mice with TNP-470 became fewer in number and smaller in diameter than those without treatment. Furthermore, there appeared extensive necrotic areas in the tumor with TNP-470. These results indicate that TNP-470 is a potent angiogenesis inhibitor for malignant gliomas. In addition, the studies of labeling index of BrdU and Ki67 suggest that TNP-470 may act mainly on tumor endothelial cells, thus resulting in reduction of the tumor growth.

IDENTIFICATION OF BRAIN-SPECIFIC SPLICING VARIANTS OF THE HDLG1 GENE AND ALTERED SPLICING IN NEUROBLASTOMA CELL LINES

AbstractThe human homologue of Drosophila tumor suppressor dlg, hDLG1, is one of the proteins known to interact with APC, a tumor suppressor for colorectal cancer. Alternative splicing of this gene generates transcripts either with [insertion 1 (I1)] or without 99 nucleotides in the 5′ part of the dlg homology repeats (DHR) domain. We found almost equivalent expression of these two splicing variants in most human tissues; however, in skeletal muscle the transcript with the 99-bp insertion was predominant, and in the brain, that without the 99-bp insertion was expressed predominantly. We also examined alternative splicing in the region between the SH3 and GUK domains where two different sizes of insertions, 34 nucleotides (I2) or 100 nucleotides (I3), had been reported, and found various splicing patterns among the tissues examined. In brain we detected six different, alternatively spliced transcripts, two of which included a novel, 36-bp, brain-specific exon encoding a peptide bearing significant homology to a portion of rat synapse-associated protein, SAP97/PSD95. Subsequently, we investigated the splicing patterns of the hDLG1 gene in 24 neuroblastoma cell lines. In two-thirds of these lines, the splicing patterns were altered from those observed in normal brain tissue. As one-third retained the normal brain-splicing pattern, the loss of normal splicing of hDLG1 may not in itself cause formation of tumors, but it might reflect the biological character of individual neuroblastomas.

Freehand Technique of an Electromagnetic Navigation System Emitter to Avoid Interference Caused by Metal Neurosurgical Instruments

BACKGROUND Electromagnetic (EM) navigation has been reported to be a noninvasive and easy-to-use technique. However, the use of metal neurosurgical instruments (e.g., skin hooks, head frames, brain retractors systems) can interfere with the magnetic fields of such systems. We present the freehand technique, a new technique involving the manual manipulation of the emitter of an EM navigation system, which helps to prevent interference caused by metal instruments during surgery. METHODS The AxiEM Electromagnetic StealthStation Navigation System (Medtronic) was used in this study. The emitter was placed in the sterilized surgical field, which allowed it to be moved freely during surgery. When navigation was necessary during the procedure, the assistant held the emitter at an appropriate angle to the sterile surgical field to avoid interference caused by the metal neurosurgical instruments. RESULTS During surgery involving metal surgical instruments, all of the functions of the EM navigation system were available throughout the procedure. The accuracy of the navigation system was sufficient to allow craniotomy and intradural manipulation to be conducted. CONCLUSIONS During the use of EM navigation systems, the freehand technique with the emitter can prevent interference caused by metal instruments.

Clipping of Recurrent Cerebral Aneurysms After Coil Embolization

BACKGROUND AND AIMS To assess the technical points of surgical clipping for recurrent aneurysms after coiling, we examine a consecutive series of 14 patients who underwent re-treatment. MATERIALS AND METHODS From 2009 to 2016, 27 recurrent aneurysms after coiling were re-treated with endovascular treatment or surgical clipping. Of these, 14 were re-treated surgically. In cases where the remnant neck was sufficiently large, neck clipping was chosen. Where the remnant neck was too small and the border between the thrombosed and non-thrombosed portion was distinct, partial clipping was chosen. Surgical clipping was attempted without removing the coils when technically feasible. RESULTS Among the 14 cases, neck clipping was performed in 11, partial clipping in 2, and trapping with bypass in 1 case. Clipping without removal of coils was accomplished in all cases. No neurological deterioration occurred after surgical clipping in any case. CONCLUSION Clipping of recurrent aneurysms after coiling can compensate for the failure of initial endovascular therapy. For clipping without removal of coils, precise evaluation of the remnant neck is required. Bypass surgery is key to treatment in the case of aneurysm trapping.

Direct Surgery of Previously Coiled Large Internal Carotid Ophthalmic Aneurysm for the Purpose of Optic Nerve Decompression

Background Progressive visual loss after coil embolization of a large internal carotid ophthalmic aneurysm has been widely reported. It is generally accepted that the primary strategy for this complication should be conservative, including steroid therapy; however, it is not well known as to what approach to take when the conservative therapy is not effective. Case Presentation We report a case of a 55-year-old female presenting with progressive visual loss after the coiling of a ruptured large internal carotid ophthalmic aneurysm. As the conservative therapy had not been effective, we performed neck clipping of the aneurysm with optic canal unroofing, anterior clinoidectomy, and partial removal of the embolized coils for the purpose of optic nerve decompression. After the surgery, the visual symptom was improved markedly. Conclusions It is suggested that direct surgery for the purpose of optic nerve decompression may be one of the options when conservative therapy is not effective for progressive visual disturbance after coil embolization.

Traumatic Entrapment of the Vertebral Artery Demonstrated by a 3D Angiographic Study

BACKGROUND Vertebrobasilar artery entrapment resulting from a clivus fracture is rare. The entrapped lesions are not radiographically depicted precisely because they are only identified by autopsy or completely occluded. In addition, no changes in the features have been revealed clearly because radiologic examinations were performed only in the acute stage. CASE DESCRIPTION We report a case of traumatic entrapment of the vertebral artery depicted precisely by a three-dimensional angiographic study in the subacute stage, presenting the serial changes in the morphologic features and a review of the published cases. CONCLUSION It is necessary to manage vertebrobasilar artery entrapment cautiously because it is suggested that the entrapped lesion is accompanied by arterial dissection.