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Toshiaki Abe

Publications and source records attributed to Toshiaki Abe.

66 records · Page 4Linked to original sources
PubMed2002

Laminoplasty with preservation of posterior cervical elements: surgical technique.

OBJECTIVE: We have developed a modified laminoplasty procedure that preserves the posterior cervical elements, and we have used it to treat multilevel cervical canal stenosis, with or without spondylotic changes, in 30 patients. METHODS: In this procedure, the posterior bony elements, such as the spinous processes, are not completely detached from the ligaments and musculature and are repositioned in the midline, to maintain normal cervical anatomic relationships. Thirty patients (mean age, 55.2 yr) were registered and evaluated in this study, with a mean follow-up period of 18.1 months, between November 1995 and October 2000. The rates of bony union of the reconstructed laminae and alignment of the cervical spine were assessed by using computed tomographic scans and lateral radiographs. RESULTS: All patients except one noted some improvement in sensation, motor function, or both. Changes in spinal curvature were noted for two patients for whom a kyphotic deformity had developed before surgery (because of S-shaped or straight curvature). The average decrease in the range of motion was 7.26 degrees. Estimated rates of bony fusion at the sites of the gutters, spacers, and spinous processes were 94.6, 62.3, and 86.6%, respectively. A stable bony arch was assumed to be achieved with bony fusion at the gutters on the hinge side, as well as the spinous processes, approximately 6 months after surgery. CONCLUSION: Our new technique of cervical laminoplasty preserves the posterior musculature and bony elements. This new procedure also helps maintain correct spinal alignment.

Adult↗
PubMed2002

Can transcranial ultrasonication increase recanalization flow with tissue plasminogen activator?

BACKGROUND AND PURPOSE: In thrombolytic therapy for acute ischemic stroke, it is essential to obtain rapid thrombolysis before ischemic neuronal injury occurs. To develop a new technique of thrombolysis for acute ischemic stroke, the effect of transcranially applied ultrasound (TUS) on thrombolysis was examined. METHODS: An occlusion model of rabbit femoral artery was produced with thrombin after establishment of stenotic flow and endothelial damage. After stable occlusion was confirmed, monteplase (mtPA) was administered intravenously, and ultrasound (490 kHz, 0.13 W/cm2) was applied through a piece of temporal bone (TUS group; n=9). The control group received mtPA alone (tissue plasminogen activator [tPA] group; n=12). To verify the efficacy of TUS, femoral artery flow was measured during the procedure. RESULTS: The recanalization ratio was 16.7% (2 of 12) in the tPA group and 66.7% (6 of 9) in the TUS group. The recanalization ratio in the TUS group was higher than that in the tPA group (P=0.03). Patency flow ratio, which was defined as recanalization flow divided by baseline flow, of the TUS group (44.6+/-13.9%) was significantly greater than that of the tPA group (9.9+/-6.8%) at 60 minutes (P=0.025). Patency flow ratio became higher in the TUS group than in the tPA group between 20 and 30 minutes from the start of thrombolysis. CONCLUSIONS: Low-frequency and low-intensity TUS enhanced thrombolysis by mtPA in a rabbit femoral artery occlusion model. This technique should be clinically useful for thrombolysis in acute ischemic stroke.

Animals↗
PubMed2002

[Combination of intravascular surgery and surgical operation for occipital subcutaneous arteriovenous fistula in a patient with neurofibromatosis type I].

We presented a case of neurofibromatosis type I (NF-1) associated with an extracranial arteriovenous fistula (AVF) fed by the occipital and vertebral artery. A 20-year-old man was referred to our hospital because of an occipital subcutaneous pulsatile mass. A CT scan showed a huge subcutaneous enhanced mass. Angiography revealed that the occipital AVF was fed by bilateral occipital arteries, the left ascending pharyngeal artery, the left middle cerebral artery, and the left vertebral artery with-abundant communication with the subcutaneous veins. Endovascular treatment by using both coil and glue (Eudragid) embolization via the occipital artery successfully obliterated the AVF. Subsequently surgical operation was performed. Postoperative angiography showed the disappearance of the AVF. Combination of intravascular surgery and surgical operation should be considered as an effective treatment for NF-1 associated with AVF.

Adult↗
PubMed2002

[A case of falcotentorial meningioma with visual allesthesia].

Visual allesthesia, in which visual images are transposed from one homonymous half-field of visual field to another, is a rare phenomenon. Palinopsia is the persistence or recurrence of visual images after the exciting stimulus object has been removed. Some authors have reported these phenomena, but these pathophysiology has not been understood. We report a right-handed 63-year-old woman, with a right falcotentorial meningioma. She paroxysmally experienced illusory transpositions of objects viewed in the right homonymous visual field into the left, and she recognized her face in it. The illusory images were palinoptic, persisting for up to a few minutes after the real objects were no longer in view. Administration of anticonvulsant medications resulted in the decrease of frequency of this phenomenon. Radiological and surgical findings revealed that the tumor was compressing the very localized visual cortex, especially the Brodmann's area 18 and 19. After resection of the tumor, visual allesthesia and palinopsia completely disappeared. These areas are associated with memory and recognition of visual images as visuopsychic area. This case provides some insight into the mechanisms of this phenomenon, and we consider that it could be caused by seizure activity in this lesion.

Female↗
PubMed2002

Protective effect against ischemia and light damage of iris pigment epithelial cells transfected with the BDNF gene.

PURPOSE: Brain-derived neurotrophic factor (BDNF) has been reported to protect retinal neurons against ischemia and light-induced damage. In the current study, the BDNF gene was transfected into iris pigment epithelial (IPE) cells of Long-Evans rats, and the neuroprotective ability of the IPE cells transfected with the BDNF gene against N-methyl-D-aspartate (NMDA)-induced neuroretinal cell death and against phototoxic damage was examined. METHODS: The level of BDNF mRNA and protein expressed in the transfected cells was determined by reverse transcription-polymerase chain reaction (RT-PCR) and by sandwich enzyme-linked immunosorbent assay (ELISA). The neuroprotective effects were determined by culturing BDNF gene-transfected IPE cells or nontransfected cells with neuroretinal cells in the presence of NMDA. The neuroprotective activity was also evaluated for the damage induced by constant exposure to light on the photoreceptors by transplanting BDNF gene-transfected IPE cells into the subretinal region of the superior half of the eye. RESULTS: BDNF gene-transfected IPE cells expressed higher levels of BDNF mRNA and protein than did nontransfected IPE cells. A significant increase in the protection against NMDA was observed in the neuroretinal cells cultured with BDNF-transfected IPE cells than in those cultured with nontransfected IPE cells (P = 0.0029) or with nontreated cells (P = 0.0010). The effect was partially attenuated by the addition of anti-BDNF antibody. Significant photoreceptor cell protection against injury from constant light was also observed by the subretinal transplantation of BDNF-transfected IPE cells when compared with those receiving transplants of nontransfected cells or vehicle injection. CONCLUSIONS: BDNF-transfected IPE cells demonstrated a neuronal rescue effect in both in vitro and in vivo experiments. IPE cells may be a potential source for autologous cell transplantation for some retinal diseases, and the transfection of the genes of neurotrophic factors into the transplanted cell may be a useful tool for delivering these factors to the retina.

Animals↗
PubMed2002

[Regeneration of the retina using pigment epithelial cell transplantation].

At has been reported that transplantation of appropriate cells, growth factors, and/or extracellular matrix may help the regeneration of damaged tissues or organs. Some growth factors, such as basic fibroblast growth factor(bFGF), have been successfully transferred to patients with ischemic heart disease. Embryonic dopamine neurons were also transplanted into the brains of patients with Parkinson's disease successfully. We have also performed cultured auto iris pigment epithelial cell (IPE) transplantation into the subretinal space after removal of choroidal neovascularization in patients with age-related macular degeneration (AMD). Here, we report the results of auto IPE transplantation in 35 patients, who could be followed for more than 6 months. We also tried to apply cell transplantation to other retinal diseases by managing the transplanted cells as introduced growth factor genes. Auto IPE transplantation was performed after removal of choroidal neovascular membranes (CNV). Visual acuity wes improved by more than 0.2 log MAR in 18 of 35 patients (51.5%), it was unchanged in 11 patients (31.5%), and it was worsened in 6 patients (17%). No significant difference was observed in comparison to patients who underwent CNV removal only. However, unlike the previous reports, we found no patients showing rejection. We also found that the cultured transplanted cells never showed proliferation under the retina or in the vitreous cavity and concluded that cultured auto IPE transplantation can be performed safely without complications. Next, we examined whether cell transplantation can be expanded to other degenerative retinal diseases. One of our results showed that host RPE may play an important role against the transplanted cells in the subretinal regions. When we introduced bFGF gene into the cells, we found synexpression cluster of the genes in the cells. One of the most prominent movements among the genes was lysyl oxidase like-1 gene, which plays an important role in the maturation of the extracellular collagen and in cell attachment. However, when we examined the cell attachment on the culture plates after 12 hours of culture, no significant difference was observed between the cells with or without bFGF. Further, when we examined the area of the cells transplanted into the subretinal space of rats during successive follow-up using fluorescein marker (EGFP), no statistical significance was observed. The gene expression pattern may be different when we introduce different growth factor gene. No antibody production was generated against the growth factor gene introduced cells after cell transplantation. Further, when we made transgenic mice expressing bFGF or Axokine cDNA in the RPE of rd mice, no photoreceptor degeneration was observed. One of the reasons was suspected to be that bFGF was expressed systemically by the promoter of tyrosinase related-protein 1 gene and may lead to lethality. Another reason was suspected to be suppression of the function of Axokine by the down-regulation of the ciliary neurotrophic factor or its receptor gene. Conversely, when we produced photoreceptor degeneration by constant light damage in the rats, we found partial photoreceptor rescue by transplantation of the growth factor gene introduced RPE. We show here the possibility that growth factor gene introduced cell transplantation may be applied to retinal diseases, if we select appropriate cells and genes.

Aged↗
PubMed2001

Antitumor Effect of Immunizations With Fusions of Dendritic and Glioma Cells in a Mouse Brain Tumor Model.

SUMMARY: The authors studied antitumor immunity conferred by fusions of dendritic and glioma cells in a mouse brain tumor model. Previous immunization with fusion cells (FCs) prevented tumor formation on challenge with glioma cells in the flank or in the brain. Efficacy was decreased when studies were performed in mice depleted of CD8+ cells. In a treatment model, FCs were injected subcutaneously after tumor development in the brain. The administration of FCs alone had limited effects on survival of mice bearing brain tumors. Importantly, however, administration of FCs and recombinant interleukin-12 (rIL-12) remarkably prolonged the survival of mice with brain tumors. Cytotoxic T lymphocyte activity against glioma cells from immunized mice was also stimulated by coadministration of FCs and rIL-12 compared with that obtained with FCs or rIL-12 alone. These data support the therapeutic efficacy of combining FC-based vaccine therapy and rIL-12.

Journal Article↗
PubMed1997

Electron-Transfer Reactions of Aromatic alpha,beta-Epoxy Ketones: Factors That Govern Selective Conversion to beta-Diketones and beta-Hydroxy Ketones.

Photoreaction of trans-1-(4-cyanophenyl)-3-phenyl-2,3-epoxy-1-propanone (trans-4'-cyanochalcone epoxide) with various electron donors was studied. Irradiation of this epoxy ketone with amines produced 1-(4-cyanophenyl)-3-phenyl-1,3-propanedione and 1-(4-cyanophenyl)-3-hydroxy-3-phenyl-1-propanone in various ratios depending on the kinds of amine and solvent used. A reaction mechanism involving an amine cation radical-assisted rearrangement of the epoxy ketone anion radical was proposed to be most consistent with the marked change in the yield of beta-diketone. On the other hand, the timing of proton transfer to the anionic intermediates is considered to be a key factor to yield the beta-hydroxy ketone. Information obtained from the photochemical study was useful to find the reaction conditions for the conversion of several aromatic epoxy ketones to hydroxy ketones by the use of samarium diiodide. Addition of methanol significantly changed the product distribution. Proper choice of water or methanol as a proton source produced hydroxy ketones in moderate to good yields.

Journal Article↗
PubMedDate not supplied

Vaccination of glioma patients with fusions of dendritic and glioma cells and recombinant human interleukin 12.

Despite aggressive treatment, the median survival of patients with high-grade malignant astrocytoma is about 1 year. The authors investigated the safety and clinical response to immunotherapy using fusions of dendritic and glioma cells combined with recombinant human interleukin 12 (rhIL-12) for the treatment of malignant glioma. Fifteen patients with malignant glioma participated in this study. Dendritic cells were generated from peripheral blood. Cultured autologous glioma cells were established from surgical specimens in each case. Fusion cells were prepared from dendritic and glioma cells using polyethylene glycol. All patients received fusion cells intradermally on day 1. rhIL-12 was injected subcutaneously at the same site on days 3 and 7. Response to the treatment was evaluated by clinical observations and radiologic findings. No serious adverse effects were observed. In four patients, magnetic resonance imaging showed a greater than 50% reduction in tumor size. One patient had a mixed response. These results show that administration of fusion cells and rhIL-12 safely induces clinical antitumor effects in some patients with malignant glioma.

Adult↗
PubMedDate not supplied

Experimental gizzard erosions in specific-pathogen-free chicks by serotype 1 group I avian adenoviruses from broilers.

The pathogenicity of serotype 1 group I avian adenovirus (GIAAV) strains isolated from gizzard erosions for 1-wk-old specific-pathogen-free (SPF) chickens was investigated. In Experiment 1, SPF chickens inoculated orally with a serotype 1 strain (Tokushima2000/GE) of GIAAV isolated from gizzard erosion in broilers were euthanatized and necropsied from 3 to 12 days after inoculation. Clinically, there were no significant signs in the chickens inoculated with Tokushima strain. The gizzards were found macroscopically to be dilated with liquefied contents. The koilin layer of the gizzard exhibited multifocal white lesions with occasional erosions. Gross lesions of the koilin layer (white foci and erosion) appeared at 3 days after inoculation and persisted until 12 days after inoculation. The gross lesions were most severe at 9 days after inoculation. Histologically, multifocal degeneration, necrosis, and loss of the glandular epithelial cells with intranuclear inclusions, liquefactive change of koilin substance, and erosive lesions of koilin layers and surface epithelium of the gizzards were observed. Macrophages increased in the focal areas of the lamina propriabelow the liquefactive koilin substances. Immunohistochemically, intranudear inclusions were positive against GIAAV antigen. Histologic lesions of gizzards were most severe at 7 and 9 days after inoculation, but the frequency of intranuclear inclusions was greatest at 5 days after inoculation. In Experiment 2, the pathogenicities of four strains of serotype 1 GIAAV for 1-wk-old SPF chickens were compared. Three strains isolated from gizzard erosion had similar pathogenicities but one strain from a normal chicken was not pathogenic for chickens. These results suggest that gizzard erosions by serotype 1 GIAAV infection may occur in broiler chickens in Japan.

Adenoviridae Infections↗