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Satoshi Goto

Publications and source records attributed to Satoshi Goto.

32 records · Page 2Linked to original sources
PubMed2004

MR imaging findings of spinal posterior column involvement in a case of Miller Fisher syndrome.

SUMMARY: The site of lesions causing ataxia in Miller Fisher syndrome (MFS) remains in dispute. A 43-year-old man manifested rapidly progressive left-sided ptosis, bilateral abducens palsy, areflexia, and severe ataxia. Initial MR imaging showed confined lesions of the cauda equina with gadolinium enhancement. A diagnosis of MFS was made, and the patient underwent immunotherapy. His ophthalmoplegia disappeared, but other symptoms remained. Five months after onset, MR imaging disclosed lesions confined to the spinal posterior column, which were considered to result from involvement of posterior nerve roots of the cauda equina and to be responsible for his remaining severe ataxia.

Adult↗
PubMed2003

Lack of Reelin causes malpositioning of nigral dopaminergic neurons: evidence from comparison of normal and Reln(rl) mutant mice.

The reeler gene (Reln(rl), formerly rl) product Reelin controls neuronal migration and positioning and thereby plays a key role in brain development. Mutation of Reln leads to widespread disruption of laminar cortical regions and ectopia in some brainstem nuclei. In the embryonic striatum of normal mice, a substantial expression of reelin mRNA has been documented; however, the anomalous positioning of neurons in the basal ganglia of reeler mice remains to be studied. We provide first evidence for a potential role of Reelin in the developmental formation of the substantia nigra. In reeler mutant mice lacking Reelin, dopaminergic neurons destined for the substantia nigra fail to migrate laterally and become anomalously clustered just lateral to the ventral tegmental area. Their axons appear to project to striatal patches forming "dopamine islands." Results from the normal mice show that, at the midembryonic stage, Reelin identified with CR-50 is highly concentrated in the ventral mesencephalon, where nigral dopaminergic neurons are in progress to migrate laterally to their eventual position of the adult brain. A combination of CR-50 labeling and anterograde axonal tracing provided evidence that embryonic striatal neurons may supply the ventral portion of the mesencephalon with Reelin through their axonal projections. We hypothesize that Reelin plays a role in the positioning of nigral dopaminergic neurons and that it can act as an environmental cue at a remote site far from its birthplace via a transaxonal delivery system.

Animals↗
PubMed2003

The role of Wg signaling in the patterning of embryonic leg primordium in Drosophila.

Cellular interaction between the proximal and distal domains of the limb plays key roles in proximal-distal patterning. In Drosophila, these domains are established in the embryonic leg imaginal disc as a proximal domain expressing escargot, surrounding the Distal-less expressing distal domain in a circular pattern. The leg imaginal disc is derived from the limb primordium that also gives rise to the wing imaginal disc. We describe here essential roles of Wingless in patterning the leg imaginal disc. Firstly, Wingless signaling is essential for the recruitment of dorsal-proximal, distal, and ventral-proximal leg cells. Wingless requirement in the proximal leg domain appears to be unique to the embryo, since it was previously shown that Wingless signal transduction is not active in the proximal leg domain in larvae. Secondly, downregulation of Wingless signaling in wing disc is essential for its development, suggesting that Wg activity must be downregulated to separate wing and leg discs. In addition, we provide evidence that Dll restricts expression of a proximal leg-specific gene expression. We propose that those embryo-specific functions of Wingless signaling reflect its multiple roles in restricting competence of ectodermal cells to adopt the fate of thoracic appendages.

Animals↗
PubMed2003

Distinct developmental modes and lesion-induced reactions of dendrites of two classes of Drosophila sensory neurons.

Little has been understood about the underlying mechanisms that generate the morphological diversity of dendritic trees. Dendritic arborization neurons in Drosophila provide an excellent model system to tackle this question, and they are classified into classes I-IV in order of increasing arbor complexity. Here we have developed transgenic green fluorescent protein markers for class I or class IV cells, which allowed time-lapse recordings of dendritic birth in the embryo, its maturation processes in the larva, and lesion-induced reactions. The two classes used distinct strategies of dendritic emergence from the cell body and branching, which contributed to differences in their basic arbor patterns. In contrast to the class I cells examined, one cell of class IV, which was a focus in this study, continued to elaborate branches throughout larval stages, and it was much more capable of responding to the severing of branches. We also investigated the cellular basis of field formation between adjacent class IV cells. Our results support the fact that class-specific inhibitory interaction is necessary and sufficient for tiling and confirmed that this intercellular communication was at work at individual dendrodendritic interfaces. Finally, this inhibitory signaling appeared to play a central role when arbors of adjacent cells started meeting midway between the cells and until the body wall became partitioned into abutting, minimal-overlapping territories.

Animals↗
PubMed2003

Molecular cloning and identification of 3'-phosphoadenosine 5'-phosphosulfate transporter.

Nucleotide sulfate, namely 3'-phosphoadenosine 5'-phosphosulfate (PAPS), is a universal sulfuryl donor for sulfation. Although a specific PAPS transporter is present in Golgi membrane, no study has reported the corresponding gene. We have identified a novel human gene encoding a PAPS transporter, which we have named PAPST1, and the Drosophila melanogaster ortholog, slalom (sll). The amino acid sequence of PAPST1 (432 amino acids) exhibited 48.1% identity with SLL (465 amino acids), and hydropathy analysis predicted the two to be type III transmembrane proteins. The transient expression of PAPST1 in SW480 cells showed a subcellular localization in Golgi membrane. The expression of PAPST1 and SLL in yeast Saccharomyces cerevisiae significantly increased the transport of PAPS into the Golgi membrane fraction. In human tissues, PAPST1 is highly expressed in the placenta and pancreas and present at lower levels in the colon and heart. An RNA interference fly of sll produced with a GAL4-UAS system revealed that the PAPS transporter is essential for viability. It is well known that mutations of some genes related to PAPS synthesis are responsible for human inherited disorders. Our findings provide insights into the significance of PAPS transport and post-translational sulfation.

Amino Acid Sequence↗
PubMed2003

Neuronal cell migration for the developmental formation of the mammalian striatum.

The mammalian striatum is the largest receptive component of the basal ganglia circuit. It is involved in the control of various aspects of motor, cognitive, and emotional functions. In the telencephalon, the striatum has a unique histological property totally different from the cortical area and its ontogenesis remains largely unknown. In this review, we introduce recent advances in the understanding of neuronal cell migration, one of the most critical processes in the early phase of histogenesis that occurs in the embryonic striatum. It appears that there are three major modes of neuronal cell migration in the developmental formation of the striatum. They are (radial) outward, tangential, and inward migration, supplying the striatum with projection neurons, interneurons, and early-generated transient neurons that originate in the preplate, respectively. We challenge the classical concept that the striatum is solely derived from the restricted germinal area located in the basal telencephalon by providing evidence that striatal development requires the intermixture of different types of neurons originating from distinct regions of the telencephalon.

Animals↗
PubMed2003

GPi pallidotomy for Parkinson's disease with drug-induced psychosis.

Levodopa-induced psychosis may seriously threaten the ability of patients with Parkinson's disease (PD) to continue leading an independent life. A retrospective assessment of the therapeutic effects of the globus pallidus internus (GPi) pallidotomy on the activities of daily living (ADL) of seven PD patients presenting with mild or moderate degrees of psychosis was carried out. Their scores according to the Unified Parkinson's Disease Rating Scale (UPDRS) Part I-2 (maximum=4) were 2 or 3 (mean +/- SD=2.4 +/- 0.5). Bilateral procedure was needed in 5 out of 7 patients to obtain sufficient improvement of motor symptoms. At 3 months after surgery, UPDRS part III motor scores in the 'off' state were significantly decreased and motor fluctuations were abolished. Nevertheless, their score of Schwab and England (S-E) ADL scale scores responded poorly to the surgery, while the scores in other 12 patients without psychosis was significantly improved after pallidotomy. The data indicate that GPi pallidotomy ameliorates the motor symptoms in patients with drug-induced psychosis (DIP), but has no significant impact on their consequent daily activities. A regression model for all 19 patients who underwent pallidotomy revealed that postoperative S-E scale was affected by the preoperative UPDRS Part I-2 rather than by Part III motor score. The present study suggested that DIP, even if its degree is not severe, may be a limiting factor of the therapeutic potential of pallidotomy in patients with PD.

Adult↗
PubMed2003

Natural course of disc displacement with reduction of the temporomandibular joint: changes in clinical signs and symptoms.

PURPOSE: The goal of this study was to examine the natural course of disc displacement with reduction in the temporomandibular joint (TMJ). PATIENTS AND METHODS: This retrospective study involved 24 patients who had been diagnosed with disc displacement with reduction of the TMJ, but who had not undergone any treatment. The extent of maximal mouth opening, protrusion, lateral excursions, noise of the TMJ, pain of the TMJ, and tenderness of masticatory muscles were recorded monthly for a mean of 25.8 months. RESULTS: Maximal mouth opening, protrusion, and lateral excursions remained unchanged during follow-up. TMJ pain decreased by 15.7% (P >.05). Clicking decreased by 20.8% (P <.05), and tenderness of masticatory muscles decreased by 33.3% (P <.05). Reciprocal clicking remained unchanged in 19 patients (79.2%) and disappeared in 5 patients (23.8%). Four patients (16.7%) in whom clicking disappeared had a normal mouth opening, but locking developed in 1 patient (4.2%). CONCLUSIONS: In patients with disc displacement with reduction who do not undergo treatment, range of movement remains unchanged over time. Tenderness of masticatory muscles tended lessen, but reciprocal clicking and TMJ pain tended to remain. Clicking did not progress to locking in most patients.

Adolescent↗
PubMed2002

Changes of the collagen fibre arrangement of the rabbit temporomandibular joint following discectomy.

PURPOSE: The purpose of the present study is to examine changes in arrangement of collagen fibres of the temporomandibular joint (TMJ) following discectomy. MATERIAL AND METHODS: Twelve male Japanese white rabbits were used. The right TMJs of six rabbits were surgically exposed, and the disc removed with a scalpel. Three untreated and three sham-operated rabbits were used as controls. The TMJs were removed in three rabbits 1 month and in three other rabbits, 3 months after discectomy and processed for demonstration of collagen fibres. RESULTS: One month after discectomy, collagen fibres in the fibrous layers of condyle and articular eminence were of various sizes and were running in various directions. Collagen fibres in the cartilaginous layers were sparser in the study TMJs than in the control TMJs. Three months after discectomy, the direction of collagen fibres in the fibrous layers of the condyle and articular eminence became organized and were similar to that in the control TMJs. However, collagen fibres in the cartilaginous layers of the condyle remained sparser 3 months after discectomy than in the control TMJs. CONCLUSION: Experimental discectomy in the rabbit alters the distribution and density of collagen fibres in the TMJ. Thorough postoperative follow-up seems to be necessary after discectomy.

Animals↗
PubMed2002

Involvement of reelin and Cajal-Retzius cells in the developmental formation of vertical columnar structures in the cerebral cortex: evidence from the study of mouse presubicular cortex.

The mammalian cerebral cortex is organized into horizontal and vertical arrays of neurons and their fiber connections that form anatomically and physiologically distinct laminar and columnar compartments. However, the developmental mechanism(s) underlying this dichotomous pattern remains a mystery. We provide anatomical evidence suggesting that reelin, a diffusible protein produced and secreted by Cajal-Retzius cells, is involved in the developmental formation of the vertical cell structures in the mouse presubicular cortex, the unique site where the vertical columnar arrays of cortical plate neurons and their dendritic branches are clearly identified during the early postnatal period. Our results also suggest that reelin plays a role in the formation of these vertical structures by acting as an inhibitory or stop signal for cortical plate neurons and their dendritic extensions. In addition to having perturbed horizontal laminae, reeler mutant mice, lacking reelin, display disruption of these vertical structures. Based on the present findings, we hypothesize that reelin and Cajal-Retzius cells regulate the developmental formation of not only horizontal laminations, but also vertical columnar structures in the cerebral cortex.

Animals↗
PubMed2002

Impact of posterior GPI pallidotomy on leg tremor in Parkinson's disease.

Although stereotactic thalamotomy is the mainstay in the surgical treatment of tremor in patients with Parkinson's disease (PD), this surgery is not favored and is even a matter of potential concern in the treatment of leg tremor since it carries a significant risk of injury to the internal capsule. In this study we have carried out a quantitative assessment of leg tremor alleviation in 12 patients with PD after MRI-/microelectrode-guided stereotactic ablation of the posterior part of the globus pallidus internus (GPi). The results showed that posterior GPi pallidotomy combined with drug therapy is a satisfactorily effective therapeutic strategy to treat parkinsonian leg tremor.

Globus Pallidus↗
PubMed2002

Bilateral pallidal stimulation for cervical dystonia. An optimal paradigm from our experiences.

We sought to identify optimal paradigms of bilateral globus pallidus internus (GPi) stimulation in 3 subsequent patients with severe cervical dystonia. At low frequency stimulation (50-60 Hz) with wide pulse width (500 micros) and high amplitude (4.5-8.0 V), we observed immediate and consistent improvement of dystonia and dystonia-associated pain. Stimulation of the posteroventral portion of the GPi led to pronounced alleviation of dystonia; stimulation of the anterodorsal portion or at the dorsal border of the GPi resulted in significant worsening of symptoms. The therapeutic benefit obtained by using the optimal stimulation parameters continues and has lasted for at least 1 year in each patient.

Electric Stimulation Therapy↗