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I Date

Publications and source records attributed to I Date.

At least 19 recordsLinked to original sources
PubMed2006

The high integration and differentiation potential of autologous neural stem cell transplantation compared with allogeneic transplantation in adult rat hippocampus.

Cell therapy is thought to have a central role in restorative therapy, which aims to restore function to the damaged nervous system. The purpose of this study was to establish an autologous neural stem cell (NSC) transplantation model using adult rats and to compare survival, migration, and differentiation between this system and allogeneic NSC transplantation. Furthermore, we compared the immunologic response of the host tissue between autologous and allogeneic transplantation. NSCs were removed from the subventricular zone of adult Fischer 344 rats using stereotactic methods. NSCs were expanded and microinjected into normal hippocampus in the autologous brain. Allogeneic NSC (derived from adult Wistar rats) transplantation was performed using the same procedure, and hippocampal sections were analyzed immunohistologically 3 weeks post-transplantation. The cell survival and migration rate were higher for autologous transplantation than for allogeneic transplantation, and the neuronal differentiation rate in the autologous transplanted cells far exceeded that of allogeneic transplantation. Furthermore, there was less astrocyte and microglia reactivity in the host tissue of the autologous transplantation compared with allogeneic transplantation. These findings demonstrate that immunoreactivity of the host tissue strongly influences cell transplantation in the CNS as the autologous transplantation did not induce host tissue immunoreactivity; the microenvironment was essentially maintained in an optimal condition for the transplanted cells.

Animals↗
PubMed2006

Differential diagnosis of the infundibular dilation and aneurysm of internal carotid artery: assessment with fusion imaging of 3D MR cisternography/angiography.

Fusion imaging of 3D MR cisternography/angiography was used for the assessment of the vascular bulging finding detected by MR angiography from the viewpoint of the outer wall configuration of the corresponding internal carotid artery depicted by MR cisternography. With a fusion image, useful information was obtained to distinguish an infundibular dilation and enlarged origin of the normal posterior communicating artery from an aneurysm. This imaging technique can be a feasible addition to a noninvasive screening of cerebrovascular lesions with MR angiography alone.

Adult↗
PubMed2005

Emergent endovascular treatment of ruptured vertebral artery dissecting aneurysms.

The goal of this study was to evaluate the results of endovascular and surgical treatments for ruptured vertebral artery dissecting aneurysms (VADAs) to determine which treatment is preferable. We evaluated the cases of 25 consecutive patients with ruptured VADAs treated in our institution. From 1992 to 1997, five patients were treated surgically. Since 1998, 20 patients with VADAs have been treated with endovascular therapy. The goal of the treatment was to exclude the aneurysm from the circulation. Among the five patients undergoing surgery, three aneurysms were treated with proximal clipping, one with trapping, and one with dome clipping. None of the patients were treated during the acute stage of rupture. Transient complications occurred in two patients. Of the 20 patients treated through the endovascular approach, 15 were treated within 24 h of rupture, but 12 had rebleeding before treatment. Eighteen aneurysms were occluded, along with the affected vertebral artery (VA), by using detachable coils (internal trapping), and one was occluded with the VA preserved. A stent-assisted occlusion of one aneurysm was done in a patient who had a contralateral hypoplastic VA. In both groups, the outcome of each patient depended greatly on the patient's condition before treatment and whether there was rebleeding. No posttreatment bleeding occurred. All procedures were effective, but endovascular treatment was less invasive and easier to use during the acute stage of subarachnoid hemorrhage. Although this report does not describe a controlled study, we found that endovascular treatment is preferable for treating ruptured VADAs in the acute stage.

Adult↗
PubMed2005

Endovascular treatment for elderly patients with ruptured aneurysm.

We report our results of endovascular treatment for elderly patients with ruptured aneurysm and discuss the indication for treatment. One hundred and thirty four consecutive patients with ruptured aneurysm treated in our institute during the last 4 years were retrospectively evaluated. Fifty eight patients were included in group A (over 70 years old), and 76 patients in group B (under 69 years old). In both groups, the outcome was strongly related to the preoperative Hunt & Kosnik grade. However, significant risk factors (i.e. pneumonia, rupture of extracranial aneurysm) which make prognosis poor were more common in group A. Group A showed poor outcome in grade III patients, although there were no outcome differences between the two groups in patients of other grades. Endovascular treatment for elderly patients with ruptured aneurysms seemed to be useful. Their outcome was strongly related to their preoperative condition. General risk factors should be evaluated before treatment, especially in elderly patients. Patients with low Hunt & Kosnik grade seem to be most suitable for endovascular treatment. On the other hand, outcome of patients with poor preoperative grade was worse despite the less invasive nature of endovascular treatment. An improvement of outcome in grade III patients is desirable.

Adult↗
PubMed2005

The expression and activation of matrix metalloproteinase-1 after subarachnoid haemorrhage in rats.

BACKGROUND: Collagen lattice contraction has been reported as another aspect of the pathogenesis of cerebral vasospasm after subarachnoid haemorrhage (SAH). Recently, some authors have suggested that matrix metalloproteinase-1 (MMP-1) plays an important role in collagen lattice contraction. Therefore, this study aimed to clarify a role of MMP-1 during cerebral vasospasm in a rat SAH model. METHOD: We used a single-SAH model in rats and assessed the basilar arteries (BAs) at 30 minutes and on 2 days after SAH by cross-sectional area measurement and other histological parameters. Immunohistochemistry and Western blot analysis were used to quantify MMP-1 expression and activation. RESULTS: BAs in rats significantly exhibited severe cerebral vasospasm at 30 minutes after SAH and moderate vasospasm on Day 2. The immunohistochemistry and Western blotting performed in BAs of rats demonstrated that both expression and activation in MMP-1 peaked at 30 minutes after SAH and then declined to the control level. CONCLUSIONS: MMP-1 is expressed and activated in a parallel time course to the development of cerebral vasospasm in an experimental model of SAH.

Animals↗
PubMed2004

Effect of cabergoline treatment on Cushing's disease caused by aberrant adrenocorticotropin-secreting macroadenoma.

The present case involves a 47-yr-old woman with Cushing's disease due to pituitary macroadenoma. The patient had suffered from hypertension and obesity for two yr. Her serum cortisol levels were moderately elevated throughout the observation period, and dexamethasone failed to suppress the cortisol secretion. Plasma ACTH levels were markedly high (>100 pg/ml) and did not respond to CRH provocation. Gel filtration analysis of the patient's plasma detected the existence of big ACTH molecules, which eluted with a peak of authentic 1-39 ACTH. Cranial magnetic resonance imaging (MRI) revealed a 3 cm pituitary tumor occupying the sellar region and right cavernous sinus with diffuse enhancement by gadolinium. The pituitary mass was removed by transsphenoidal surgery, and was pathologically identified as compatible to ACTH-producing pituitary adenoma by immunohistochemistry. RT-PCR analysis of total cellular RNA extracted from the resected adenoma revealed a relatively high expression level of dopamine D2 receptor (D2R) mRNA. Therefore, a long-acting D2R agonist, cabergoline (0.25 to 0.5 mg/week), was administered for the remnant adenoma, which gradually reduced ACTH levels in 90 days. In addition, cranial MRI exhibited shrinkage of the remnant pituitary mass after a 6-month treatment with cabergoline. This case demonstrates the efficacy of cabergoline to treat Cushing's disease caused by pituitary macroadenoma secreting aberrant ACTH molecules.

Adenoma↗
PubMed2002

The role of dopamine in manganese-induced oxidative injury in rat pheochromocytoma cells.

Reactive dopamine (DA) metabolites have been implicated in both Parkinson's disease and manganese (Mn) neurotoxicity. Rat PC12 and genetically modified PC12 (PC12M) cells capable of producing higher DA content, on exposure to MnCl2 (10(-6) M) for 72 hours, exhibited a significant decrease in glutathione content. Activity of antioxidant enzyme catalase was also inhibited following 24- and 72-hour MnCl2 exposure. MnCl2 caused a concentration-dependent (10(-7) to 10(-3) M) loss in mitochondrial activity after 24 and 72 hours and an impaired DNA synthesis after 72 hours with changes being more marked in PC12M cells. The results indicate that the free-radical-mediated toxicity of Mn at cellular level involves down-regulation of antioxidants in normal and DA-rich PC12 cells. PC12M cells appeared to be more sensitive than PC12 cells.

Animals↗
PubMed2002

In vitro study of encapsulation therapy for Fabry disease using genetically engineered CHO cell line.

Fabry disease is an X-linked recessive disorder caused by a deficiency of the lysosomal hydrolase alpha-galactosidase A (alpha-gal). The deficiency of this enzyme leads to the systemic deposition of ceramide trihexoside (CTH) in various tissues and organs. Enzyme replacement using IV doses of recombinant human alpha-gal produced in CHO cells or in human fibroblasts is currently being evaluated in clinical trials as a potential therapy for this disease. However, it requires lifelong therapy involving a large amount of purified alpha-gal. As a novel approach for treatment of Fabry disease we used polymer encapsulated Chinese hamster ovary (CHO) cells genetically modified to express alpha-gal. The secreted high levels of alpha-gal passed through the semipermeable polymeric membrane. Using coculture system with Fabry fibroblasts, the secreted enzyme was taken up in cells, resulting in reduced accumulation of CTH in Fabry fibroblasts. This in vitro study demonstrated that an encapsulated alpha-gal-secreting cell line can be used to treat Fabry mice by transplantation in vivo. Judging from the protection against immune rejection by a semipermeable synthetic membrane, this novel approach may be applied to treat patients with Fabry disease and other lysosomal storage diseases.

Animals↗
PubMed2001

Inhibition of poly(ADP-ribose) polymerase attenuates cerebral vasospasm after subarachnoid hemorrhage in rabbits.

BACKGROUND AND PURPOSE: Poly(ADP-ribose) polymerase (PARP) is important in modulating inflammation, which has been implicated in cerebral vasospasm after subarachnoid hemorrhage (SAH). We investigated the role of PARP in vasospasm using 3-aminobenzamide (3-AB), a PARP inhibitor, in a rabbit model. METHODS: Twenty-four New Zealand White rabbits were divided into 4 groups: (1) no treatment (control group, n=6); (2) blood injection without pretreatment (SAH-only group, n=6); (3) blood injection with pretreatment by vehicle (SAH+vehicle group, n=6); and (4) blood injection with pretreatment by 3-AB (SAH+3-AB group, n=6). We used the single-hemorrhage model of SAH, injecting autologous arterial blood into the cisterna magna. Angiography was performed before (baseline) and after (day 2) SAH, and the diameter of the basilar artery (BA) was measured. Animals were euthanatized after the second angiogram. After perfusion and fixation, the brains were cut into sections for hematoxylin and eosin and immunohistochemical staining for poly(ADP-ribosyl)ation. RESULTS: In the control group, there were no differences in the BA lumen caliber between baseline and day 2 (96.8+/-10.4%). Cerebral vasospasm in the SAH+3-AB group (88.2+/-6. 2%) was remarkably attenuated in comparison with that in the SAH-only group (64.9+/-8.0%) and the SAH+vehicle group (65.6+/-10. 8%). The BA in the SAH+3-AB group showed less corrugation of the tunica elastica interna than that in the SAH-only and SAH+vehicle groups. Staining for poly(ADP-ribosyl)ation was markedly inhibited in smooth muscle and adventitial cells of the BA in the SAH+3-AB group compared with other groups. CONCLUSIONS: Inhibiting ADP-ribosylation attenuates cerebral vasospasm after SAH in rabbits, and PARP activation may play an important role in the development of cerebral vasospasm.

Animals↗
PubMed2001

Effects of aging on cerebral vasospasm after subarachnoid hemorrhage in rabbits.

BACKGROUND AND PURPOSE: The effects of aging on cerebral vasospasm after subarachnoid hemorrhage (SAH) remain to be elucidated. The aim of this study was to clarify age-related differences of vasospasm and of papaverine reactivity in the responses of basilar arteries after SAH in rabbits. METHODS: Rabbits receiving a single injection of arterial blood into the cisterna magna were divided into 3 groups: young (2 to 3 months old), adult (6 to 9 months old), and old (20 to 40 months old). Vertebrobasilar angiograms were obtained before SAH and 1, 2, 4, and 7 days after SAH. Papaverine was administrated selectively via the vertebral artery on day 2, and serial angiography was performed for up to 2 hours. Vessel structures were assessed with light microscopy on days 1, 2, 4, and 7 after SAH and at 10, 30, and 60 minutes after papaverine infusion. RESULTS: Mortality from SAH in old rabbits was 40%, whereas that of young and adult rabbits was 0%. Angiograms revealed that SAH induced maximal constriction of the basilar arteries on day 2 in all age groups, and the constrictions were significantly increased with age at all time points investigated. The degree of dilatation of spastic basilar arteries after intra-arterial papaverine administration significantly decreased with age. Duration of the efficacy of papaverine became significantly shorter with age. Vessel diameter returned to the preinfusion value approximately 120, 60, and 30 minutes after infusion in young, adult, and old rabbits, respectively. Light microscopy in old rabbits showed luminal narrowing and corrugation of the internal elastic lamina not only in the basilar arteries but also in small arteries and intraparenchymal arterioles. CONCLUSIONS: This study suggests that aging increases the degree of vasospasm in rabbits. The impaired reactivity to papaverine with aging might imply the early transition of the aged vessel to the papaverine-resistant chronic stage.

Age Factors↗
PubMed2001

Coil embolization of intradural pseudoaneurysms caused by arterial injury during surgery: report of two cases.

Intradural pseudoaneurysms arose in two patients as a result of arterial injury incurred during surgery. In the first patient, the pseudoaneurysm developed in the middle cerebral artery, at the site of vessel perforation during aneurysmal surgery. In the second patient, the pseudoaneurysm developed in the anterior communicating artery after removal of a tuberculum sellae meningioma. These aneurysms had small ostia and were successfully embolized with electrolytically detachable coils. The clinical features and the treatment of intracranial pseudoaneurysms are discussed.

Adult↗
PubMed2001

[Use of the GDC for embolization of a tumor fed by a cavernous branch of the internal carotid artery].

Currently, embolization of small branches of the internal carotid artery (ICA) can be embolized through superselective microcatheterization, followed by the injection of liquid or particulate embolic materials. Often, however, a microcatheter cannot be placed in a stable enough position to allow an endovascular surgeon to perform a safe embolization, and the reflux of embolic agents into the main trunk of the ICA is a major concern. Meticulous technique and a detailed knowledge of the vascular anatomy of the cavernous sinus region are necessary to maximize devascularization of the lesion and to minimize the risk of complications. This report describes the case of a patient with a hypervascular tumor whose feeding vessel from the cavernous ICA was successfully occluded with polyvinyl alcohol (PVA) combined with a regular Guglielmi detachable coil (GDC). A 62-year-old woman had a left-sided petroclival meningioma, which was diagnosed based on computed tomography and magnetic resonance studies. Transfemoral angiographic studies demonstrated that the tumor was fed by intracavernous branches of the left ICA. We believed that another embolic agent would have presented a risk of reflux into the ICA, with possible unwanted occlusion of normal intracranial arteries. A single GDC was sufficient to occlude the feeding artery, and the patient underwent successful surgery 3 days after the endovascular procedure. The GDC can eliminate the ICA supply to hypervascular tumors safely when liquid or particle embolic materials would present a risk of reflux into normal arteries. This device can be positioned and repositioned and can be detached without mechanical force. It may also decrease the risk of unwanted embolization of normal intracranial arteries.

Carotid Artery, Internal↗
PubMed2001

Grafting of encapsulated genetically modified cells secreting GDNF into the striatum of parkinsonian model rats.

In order to deliver glial cell line-derived neurotrophic factor (GDNF) into the brain, we have established a cell line that produces GDNF in a continuous fashion by genetic engineering. These cells were encapsulated and grafted into parkinsonian model rats that had received unilateral intrastriatal injection of 6-hydroxydopamine 2 weeks earlier. Neurochemical analysis showed that GDNF has been produced from the capsule for 6 months after grafting and histological analysis revealed good survival of GDNF-producing cells in the capsule 6 months after grafting. The density of nigrostriatal dopaminergic fibers in the striatum as well as the number of dopaminergic cell bodies in the substantia nigra recovered significantly after GDNF-producing cell grafting. These results suggest the possible application of GDNF-producing cell grafting for the treatment of Parkinson's disease.

Animals↗
PubMed2001

Neurotrophic factor-secreting cell grafting for cerebral ischemia: preliminary report.

In this experiment, we examined a possible protective effect of encapsulated neurotrophic factor-secreting cell grafting for ischemic injury. We established a basic fibroblast growth factor (bFGF)-secreting cell line by genetic manipulation. We enveloped these cells into polymer capsules, which consist of a semipermeable membrane, and implanted them into the right striatum of rats. At 6 days after implantation, these rats received right middle cerebral artery occlusion (MCAO) using interluminal suture technique. At 24 h after MCAO, rats were sacrificed and their cerebral infarction volume was determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining and image analysis. We found approximately 30% reduction in infarct volume in the encapsulated bFGF-secreting cell grafting groups vs. the encapsulated naive BHK cell grafting group or the without implantation group. We measured bFGF secretion from encapsulated bFGF-secreting cells using enzyme-linked immunosorbent assay (ELISA). The retrieved capsules continued to secrete bFGF. There was no significant difference of bFGF secretion between the capsules before and after transplantation. A large number of viable BHK-bFGF cells was observed within the full length of the retrieved capsule. These results indicate that encapsulated bFGF-secreting cell grafting exerts a protective effect on ischemic injury.

Animals↗
PubMed2000

GDNF induces recovery of the nigrostriatal dopaminergic system in the rat brain following intracerebroventricular or intraparenchymal administration.

BACKGROUND: Glial cell line-derived neurotrophic factor (GDNF) has been shown to be a survival and neuroprotective factor for nigrostriatal dopaminergic neurons in vivo. The present study was designed to investigate the possible neuroprotective and restorative role by GDNF for dopaminergic neurons which were exposed to the neurotoxin 6-hydroxydopamine (6-OHDA). METHOD: We compared neurochemical, morphological and behavioural changes following striatal infusion of GDNF to those following intracerebroventricular (i.c.v.) infusion. FINDINGS: Apomorphine-induced rotation showed significant recovery after both types of infusion. Significant recovery of tyrosine hydroxylase (TH)-immunoreactive (IR) neurons and fibers were found in the substantia nigra and striatum following both striatum and i.c.v. infusion except for the number of TH-IR neurons in the i.c.v. infusion group. INTERPRETATION: These results suggest that GDNF induces recovery of the nigrostriatal dopaminergic system, and this indicates a potential usefulness of GDNF for the treatment of Parkinson's disease.

Adrenergic Agents↗
PubMed2000

The effect of intrastriatal single injection of GDNF on the nigrostriatal dopaminergic system in hemiparkinsonian rats: behavioral and histological studies using two different dosages.

Glial cell line-derived neurotrophic factor (GDNF) is a member of the transforming growth factor-beta superfamily and acts as a neurotrophic factor for the nigrostriatal dopamine (DA) system. Although previous studies have shown that pretreatment with GDNF could prevent degenerative changes of nigrostriatal DA system by DA neurotoxin 6-hydroxydopamine (6-OHDA), it is not really known whether GDNF can induce recovery of nigrostriatal DA system after partial lesioning by 6-OHDA. Substantia nigra has been commonly chosen as injection site for GDNF but a limited number of studies have used striatum as injection site where neural transplantation is commonly performed. Unilateral intrastriatal administration of 6-OHDA was performed in Sprague-Dawley rats to create partial lesion of the nigrostriatal DA system. These hemiparkinsonian model rats received a 10- or 100-microg single injection of human recombinant GDNF into the same portion of the striatum 4 weeks after 6-OHDA treatment. Both animals that received a 10- or 100-microg single injection of GDNF showed decreased apomorphine-induced rotation at 2 weeks after injection. More potent and prolonged functional recovery was observed in animals receiving 100 microg of GDNF than in those receiving 10 microg of GDNF. Tyrosine hydroxylase (TH) immunocytochemistry revealed that TH positive DA fiber density in the striatum and the number of DA cell bodies in the substantia nigra were greater in animals receiving 10 or 100 microg of GDNF than those receiving saline. These immunocytochemical results have also shown that 100 microg of GDNF was more potent than 10 microg of GDNF. These morphological and functional results indicate that GDNF treatment 4 weeks after 6-OHDA lesioning could induce recovery of nigrostriatal DA system. Striatum was a good site for GDNF administration for hemiparkinsonian rats and a single injection of 100 microg of GDNF was more potent than 10 microg of GDNF.

Animals↗