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Biomedical subjects

Isao Date

Publications and source records attributed to Isao Date.

At least 19 recordsLinked to original sources
PubMed2007

Preoperative simulation for microvascular decompression in patients with idiopathic trigeminal neuralgia: visualization with three-dimensional magnetic resonance cisternogram and angiogram fusion imaging.

OBJECTIVE: Precise assessment of the complex nerve-vessel relationship at the root entry zone of the trigeminal nerve is useful for planning microvascular decompression in patients with idiopathic trigeminal neuralgia. We have applied a fusion imaging technique of three-dimensional (3-D) magnetic resonance cisternography and co-registered 3-D magnetic resonance angiography (MRA) that allows virtual reality for the preoperative simulation of the neurovascular conflict at the trigeminal nerve root entry zone. METHODS: Fusion images of 3-D magnetic resonance cisternograms and angiograms were reconstructed by a perspective volume-rendering algorithm from the volumetric data sets of magnetic resonance cisternography, obtained by a T2-weighted 3-D fast spin echo sequence, and co-registered MRA, by a 3-D time-of-flight sequence. Consecutive series of 12 patients with idiopathic trigeminal neuralgia were studied with fusion 3-D magnetic resonance cisternogram and MRA in the preoperative assessment for the microvascular decompression of the affected trigeminal nerve. RESULTS: The complex anatomical relationship of the offending vessels to the trigeminal nerve root entry zone was depicted on the fusion 3-D magnetic resonance cisternogram and MRA. The presence of offending vessels and compressive site of neurovascular conflict was assessed from the various viewpoints within the cistern and was presumed by the preoperative simulation through the surgical access (surgeon's-eye view). The blinded surgical trajectory was discerned by the virtual image through the opposite direction projected from above (bird's-eye view). The 3-D visualization of the nerve-vessel relationship with fusion images was consistent with the intraoperative trajectory and findings. CONCLUSION: Fusion imaging of 3-D magnetic resonance cisternogram and MRA may prove a useful adjunct for the diagnosis and decision-making process to execute the microvascular decompression in patients with idiopathic trigeminal neuralgia.

Adult↗
PubMed2007

[Assessment of neurovascular compression in patients with trigeminal neuralgia with a boundary fusion three-dimensional magnetic resonance cisternogram/angiogram].

Precise assessment of the complex nerve-vessel relationship at the root entry zone (REZ) the trigeminal nerve is useful for the planning of the microvascular decompression (MVD) in patients with trigeminal neuralgia. We have applied a boundary imaging of fusion three-dimensional (3D) magnetic resonance (MR) cisternogram/angiogram. The boundary imaging allows virtual assessment of the spatial relationship of the neurovascular compression at the REZ of the trigeminal nerve. The boundary images depicted complex anatomical relationship of the offending vessels to the trigeminal nerve REZ. The presence of offending vessels, compressive site, and degree of neurovascular compression were assessed from various viewpoints in thl cistern and virtually through the brainstem and trigeminal nerve per se. The 3D visualization of the nerve-vessel relationship with fusion images was consistent with the intraoperative findings. The boundary fusion 3D MR cisternogram/angiogram may prove a useful adjunct for the diag nosis and decision-making process to execute the MVD in patients with trigeminal neuralgia.

Adult↗
PubMed2006

Control of dopamine-secretion by Tet-Off system in an in vivo model of parkinsonian rat.

We established a PC12 cell line (PC12TH Tet-Off) in which human tyrosine hydroxylase (TH) expression can be negatively controlled by Doxycycline (Dox). First, dopamine (DA)-secretion from PC12TH Tet-Off cells was controlled by Dox-administration in a dose-responsive manner ranging from 0 to 100 ng/ml for 70 days in vitro. Furthermore, Parkinson's disease model of rats receiving encapsulated PC12TH Tet-Off cells displayed a significant decrease of dopamine concentration in the cerebrospinal fluid (CSF) and increase of the number of apomorphine-induced rotations by Dox-administration, as compared to transplanted rats without Dox-administration, although the significant decrease of the reduction ratio of DA concentration in the CSF with Dox-administration was recognized over time. At 2 months post-implantation, concentration of dopamine in the implanted striatum and from the retrieved capsules demonstrated that the control of DA-secretion could be partially achieved for 2 months in vivo. Our results support both the value of cell therapy using Tet-Off system and the technique of encapsulation might be a feasible option for Parkinson's disease especially in resolving the problem of dopamine oversupply in the future, although a more efficient way to control DA-secretion with quicker regulation and much titration of dose should be explored before clinical application.

Animals↗
PubMed2006

Ex vivo gene therapy: transplantation of neurotrophic factor-secreting cells for cerebral ischemia.

Expressions of various neurotrophic factors or their receptors fluctuate after stroke, which in part prompted investigations into the efficacy of neurotrophic factors as treatment modality for stroke. The methods to deliver neurotrophic factors into the brain can be categorized into: 1) the surgical route of administration, such as intracerebral, intraventricular, intra-arterial, or intravenous systemic administration and 2) the manipulation of the therapeutic molecules via ex vivo or in vivo techniques. With ex vivo method, genetically engineered cells, including the use of autologous cells, have been explored. In this review, the potent therapeutic applications of neurotrophic factors in stroke are described, with emphasis on ex vivo methods, especially transplantation of encapsulated stem cells modified with adenovirus. Neurotrophic factor delivery, combined with ex vivo method, poses as novel treatment for stroke, although additional safety and efficacy studies remain to be examined.

Animals↗
PubMed2006

Transient memory disturbance after removal of an intraventricular trigonal meningioma by a parieto-occipital interhemispheric precuneus approach: Case report.

BACKGROUND: Pitfalls in a parieto-occipital interhemispheric precuneus approach for the ventricular trigonal region of a dominant hemisphere have been rarely reported. We described a case with memory disturbance after surgery using this approach. CASE DESCRIPTION: A 57-year-old, right-handed woman complained of numbness of the lower extremities and underwent magnetic resonance imaging, which incidentally demonstrated a trigonal meningioma in the left lateral ventricle with a maximal diameter of 4 cm. The patient's preoperative neurologic examination was normal. The tumor was successfully removed by a parieto-occipital interhemispheric approach with an incision of the left precuneus cortex. Postoperative motor, sensory, and visual functions were normal; however, recent memory disturbance developed, which gradually resolved in the following 3 months. CONCLUSIONS: An interhemispheric precuneus approach is a useful alternative to trigonal tumors with few surgical complications, but postoperative memory disturbance can be one pitfall of this procedure.

Female↗
PubMed2006

Successful chemotherapy for congenital malignant gliomas: a report of two cases.

We describe the cases of 2 patients with a congenital malignant glioma that responded to chemotherapy. In the first case, a 2-month-old boy had a conjugate deviation to the right side and nystagmus. A T(1)-weighted gadolinium-enhanced magnetic resonance image showed a large tumor in his right frontal lobe. The tumor was partially resected, and the histological diagnosis was malignant ganglioglioma. The child then underwent 6 cycles of chemotherapy (mainly carboplatin and etoposide), and the residual tumor shrank. The tumor was then partially resected during a second operation, after which the patient underwent 5 cycles of chemotherapy (a combination of carboplatin, etoposide, vincristine, ifosfamide, cisplatin and cyclophosphamide). The tumor has not recurred in more than 8.5 years. In the second case, a 2-month-old boy had bulging of the anterior fontanel. The T(1)-weighted gadolinium-enhanced magnetic resonance image showed a large suprasellar tumor. The tumor was partially resected, and the histological diagnosis was anaplastic astrocytoma. The patient underwent 8 cycles of chemotherapy (MCNU, carboplatin and etoposide) and the tumor has not recurred in more than 7.5 years. Our experience indicates that, if surgical removal and chemotherapy are done aggressively for malignant gliomas in neonates and infants, long-term survival is possible.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Encapsulation cell therapy for mucopolysaccharidosis type VII using genetically engineered immortalized human amniotic epithelial cells.

Mucopolysaccharidosis type VII (MPSVII) is a lysosomal storage disease resulted from a deficiency of the enzyme beta-glucuronidase (GUSB), which is necessary for degradation of glycosaminoglycans (GAGs). The deficiency of GUSB causes progressive accumulation of GAGs and subsequent lysosomal distension in multiple tissues, including the central nervous system (CNS). In murine experiments, bone marrow transplant, enzyme replacement, viral vectors, and genetically modified cells were successfully used for correction of the visceral accumulation of GAGs, but little improvement was seen in the brain, because these therapeutic agents cannot cross the blood-brain barrier (BBB). Although direct intracerebral injection of GUSB-encoding viral vectors has been developed to bypass the BBB, the possibility of tumor formation and the toxicity of over-expressed GUSB have been reported. In this study, we generated immortalized human amniotic epithelial (IHAE) cells to maintain the effect of implantation, and encapsulated these cells to prevent harmful immunological response and tumor formation and to regulate the level of GUSB expression within the host. Moreover, we generated IHAE cells that over-express and secrete human GUSB following transduction with an adenoviral vector encoding human GUSB. Therapeutic efficacy for MPSVII was evaluated in and ex vivo experiments using these encapsulated genetically engineered GUSB-encoding IHAE cells. We confirmed that encapsulated genetically engineered IHAE cells could secrete significant amounts of GUSB outside the capsule in vitro and into the cerebral parenchyma of C3H mice seven days after the capsule implantation. Thus, encapsulation cell therapy using genetically engineered IHAE cells is an effective armamentarium for the treatment of MPSVII.

Amnion↗
PubMed2006

[Direct surgery for paraclinoid aneurysm arising from the anterolateral wall of the internal carotid artery].

The internal carotid aneurysm (ICA) arising from the paraclinoid region is associated with the origins of the superior hypophyseal artery and the ophthalmic artery. Recently, other aneurysms which can arise in this region without imvolvement of the arterial branches has been reported. Among those aneurysms, there are very rare type of aneurysms located on the anterolateral aspect of the internal carotid artery. In this report, we described our experience with direct surgery for five cases of the unruptuted paraclinoid aneurysm arising from the anterolateral aspect of the ICA. Firstly, the common carotid artery was exposed to carry out proximal flow control. We used the pterional approach. The anterior clinoid process was deleted after having confirmed aneurysm and the dural ring was incised. Extreme care had to be taken during this step. All patients underwent successful neck clipping. In recent two cases we employed the neuroendoscope (EndoArm) to observe the unrecognized area of surgical microscope and untrasonic bone curette (SONOPET) to perform the safe removal of the anterior clinoid process. This procedure is very useful for carrying out the neck clipping for aneurysms which are located on the anterolateral aspect of the internal carotid artery.

Adult↗
PubMed2006

[Hemifacial spasm due to vascular compression of the distal portion of root exit zone of the facial nerve: report of two cases].

It has been generally assumed that only vascular contact at the root exit zone (REZ) of the facial nerve can cause hemifacial spasm. We treated two cases of hemifacial spasm in which compression of the distal site of the REZ of the facial nerve produced symptoms. The microvascular decompression for the patients showed excellent results. Extreme care must be taken not to stretch the internal auditory artery during surgical manipulation. The ABR monitoring is useful to prevent the postoperative hearing loss. It must be kept in mind that the compression of distal portions of the facial nerve may be responsible for hemifacial spasm in cases in which neurovascular compression at the REZ is not confirmed intraoperatively.

Aged↗
PubMed2006

[A case of pineal pure germinoma metastasized to the lumbosacral extradural space 8 years after initial therapy. Case report and review of literature].

An 11-year-old boy first presented with a pineal tumor identified by neuroimaging but without positive serum or cerebrospinal fluid markers. The tumor disappeared after the craniotomy and following cranial irradiation. The pathologic diagnosis of the tumor was of a pure germinoma. Eight years later he returned to the hospital with spinal epidural metastasis from the pineal germinoma and required surgery. Intraoperative findings showed that the spinal tumor was solitarily located in the epidural space. Pathologically the tumor was a pure germinoma metastasis. He was treated by a combination of whole spinal irradiation and chemotherapy. The tumor disappeared after the therapy. A pineal germinoma occasionally disseminates through the ventricular system and spinal subarachnoid region. However, a solitary spinal epidural metastasis from pineal germinoma has rarely been reported. Regarding the route of this metastasis, we speculate that the CSF dissemination of the germinoma cells occurred first and some of those cells were trapped in the spinal nerve sleeve and extended into the epidural space.

Adult↗
PubMed2006

[Preoperative assessment of microvascular decompression for hemifacial spasm with fusion imaging of 3D MR cisternogram/angiogram].

The preoperative assessment of microvascular decompression (MVD) for hemifacial spasm has been performed with MRI, but assessment of the compressive status by 2D imaging has a number of limitations. We used a fusion image of the 3D MR cisternogram and co-registered 3D MR angiogram, reconstructed from MR cisternogram, obtained by 3D fast spin-echo sequence, and MR angiography, 3D time-of-flight and spoiled-gradient recalled sequences, for the preoperative assessment of the offending artery in 10 patients with hemifacial spasm. The anatomical relationship of the nerve-vessel complex was assessed on the simulated images, and compared with the intraoperative findings. The fusion image of the 3D MR cisternogram/angiogram depicted contours of the brain, nerves, and vessels clearly, and that allowed precise assessment of the pathogenic compression of the facial nerve by the offending vessels, comparative to the operative findings. The fusion imaging of the 3D MR cisternogram/angiogram may provide useful information in the surgical planning of MVD for hemifacial spasm.

Adult↗
PubMed2006

[Delayed hearing loss after microvascular decompression for hemifacial spasm: report of two cases].

We report two unusual cases of delayed hearing loss after microvascular decompression (MVD) for hemifacial spasm. In the first case, A 59-year-old female noted left hearing loss one week after receiving MVD for left hemifacial spasm. In the second case, A 39-year-old male also noticed ipsilateral hearing loss on the 7th day after MVD for right hemifacial spasm. Both cases were treated by steroid. Two months after the onset, their hearing function improved dramatically. These cases indicated that the delayed hearing loss after MVD for hemifacial spasm can occur, even when gentle microsurgical technique is used, but the prognosis for this condition is fairly good.

Adult↗
PubMed2005

Neurorescue effects of VEGF on a rat model of Parkinson's disease.

Vascular endothelial growth factor (VEGF) has been shown to display neuroprotective effects on dopaminergic (DA) neurons. Here, we investigated the neurorescue effects of VEGF on 6-hydroxydopamine (6-OHDA)-treated DA neurons in vitro and in vivo. Initially, we examined in vitro whether 1, 10, or 100 ng/ml of VEGF administration at 2 or 4 h after 6-OHDA treatment rescued DA neurons derived from E14 murine ventral mesencephalon. The earlier treatment of VEGF suppressed 6-OHDA-induced loss of DA neurons more than the delayed treatment. Next, we examined whether the continuous infusion of VEGF had neurorescue effects in a rat model of Parkinson's disease. We established a human VEGF secreting cell line (BHK-VEGF) and encapsulated the cells into hollow fibers. The encapsulated cells were unilaterally transplanted into the striatum of adult rats at 1 or 2 weeks after 6-OHDA lesions, and animals subsequently underwent behavioral and immunohistochemical evaluations. Compared to lesioned rats that received BHK-Control capsules, lesioned rats transplanted with BHK-VEGF capsules showed a significant reduction in the number of amphetamine-induced rotations, a significant preservation of TH-positive neurons in the substantia nigra pars compacta, and a remarkable glial proliferation in the striatum, with the earlier transplantation exerting much more benefits than the delayed transplantation. Parallel studies revealed that the observed in vitro and in vivo neurorescue effects were likely mediated by VEGF's angiogenic and glial proliferative effects, as well as its direct effects on the neurons. Our results suggest that VEGF is a highly potent neurorescue molecule for Parkinson's disease therapy.

Adrenergic Agents↗
PubMed2005

Ubiquitination-resistant p53 protein transduction therapy facilitates anti-cancer effect on the growth of human malignant glioma cells.

Protein transduction therapy using poly-arginine can deliver the bioactive p53 protein into cancer cells and inhibits the proliferation of the cells. However, one disadvantage of such therapy is the short intracellular half-life of the delivered protein. Here, we generated mutant proteins in which multiple lysine residues in the C-terminal were substituted by arginines. The mutant proteins were effectively delivered in glioma cells and were resistant to Mdm2-mediated ubiquitination. Moreover, the mutant proteins displayed higher transcription regulatory activity and powerful inhibition of the proliferation of glioma cells. These results suggest that ubiquitination-resistant p53 protein therapy may become a new effective cancer therapy.

Adenoviridae↗
PubMed2005

Adult unilateral moyamoya disease with familial occurrence in two definite cases: a case report and review of the literature.

We documented an interesting case of adult "unilateral (probable)" moyamoya disease displaying familial occurrence in two "definite" cases. A 55-year-old female presented with motor aphasia, involuntary movement of the right hand and right homonymous hemianopia due to cerebral infarction. Cerebral angiography revealed typical angiographic findings on the left side and normal findings on the right side; consequently, the patient was diagnosed with probable moyamoya disease. Previously, her mother and nephew had been diagnosed with definite moyamoya disease with bilateral involvement. The patient continued to exhibit unilateral involvement on angiography for more than 4 years. Clinical features such as absence of familial occurrence suggest that most cases of probable moyamoya disease are distinct from definite cases, especially in adults. To the best of our knowledge, this report appears to be the first involving an adult probable case characterized by familial occurrence. The literature pertaining to adult probable moyamoya disease was reviewed and the etiology of this disease was discussed.

Aphasia, Broca↗
PubMed2005

Toxicity of semaphorin3A for dopaminergic neurons.

Semaphorin3A (Sema3A) is known to cause neuronal apoptosis and serves as a chemorepellent factor for axonal growth. In our previous report, we found that Sema3A was up-regulated in the 6-OHDA-injected striatum of rats, suggesting that Sema3A was likely involved in dopaminergic (DA) depletion. In this study, we investigated whether Sema3A directly worked as a neurotoxin to DA neurons both in vitro and in vivo. First, effects of various dosages of Sema3A administration on the DA neurons of the E14 murine ventral mesencephalon were examined in vitro. Sema3A at a dose over 500 ng/ml induced apoptosis to DA neurons. Next, we examined whether the continuous infusion of Sema3A exerted degeneration of DA neurons in rats. We established a Sema3A-secreting cell line (BHK-Sema3A), confirming the secreting functions by immunocytochemical and Western blot assays. Adult Sprague-Dawley rats were unilaterally implanted into the striatum with BHK-Sema3A or BHK non-Sema3A control cells, and subsequently underwent behavioral and immunohistochemical evaluations. Rats that received BHK-Sema3A did not show significant differences in the number of amphetamine- and apomorphine-induced rotations and TH-positive neurons in the substantia nigra pars compacta compared to the control group. Our results revealed that Sema3A was toxic to cultured DA neurons at very high dosages, but the continuous secretion of Sema3A at modest dosage in vivo did not produce Parkinsonian pathophysiologic symptoms. Optimizing the dosage and infusion location (i.e., nigra) and timing (more than 1 week post-transplantation) might further reveal the contribution of Sema3A to the pathogenesis of Parkinson's disease.

Amphetamine↗
PubMed2005

The differences between high and low-dose administration of VEGF to dopaminergic neurons of in vitro and in vivo Parkinson's disease model.

Vascular endothelial growth factor (VEGF) has previously been shown to display neuroprotective effects on dopaminergic (DA) neurons. In this study, we investigated whether the effects of VEGF were dose-dependent or not. First, VEGF was shown to be neuroprotective on 6-hydroxydopamine (6-OHDA)-treated murine DA neurons in vitro, although the 1 ng/ml of VEGF displayed more neuroprotective effects than 100 ng/ml. Furthermore, using 2 sizes of capsules (small/large) with different secreting quantities, 6-OHDA-treated rats receiving the small capsule filled with VEGF-secreting cells (BHK-VEGF) into the striatum showed a significant decrease in amphetamine-induced rotational behavior in number and a significant preservation of TH-positive fibers compared to those receiving the large BHK-VEGF capsule as well as those receiving BHK-Control capsule. Rats receiving the large BHK-VEGF capsule showed much more glial proliferation, angiogenesis, and brain edema around the capsule than those with the small one. High-dose administration of VEGF might cause poor circulation related to brain edema, although low-dose administration of VEGF displays neuroprotective effects on DA neurons. Our results demonstrate the importance of administration dose of VEGF, suggesting that low-dose administration of VEGF might be desirable for Parkinson's disease.

Amphetamine↗