Publications by authors named "Kohga H"

Protein translocation across cellular membranes is an essential and nano-scale dynamic process. In the bacterial cytoplasmic membrane, the core proteins in this process are a membrane protein complex, SecYEG, corresponding to the eukaryotic Sec61 complex, and a cytoplasmic protein, SecA ATPase. Despite more than three decades of extensive research on Sec proteins, from genetic experiments to cutting-edge single-molecule analyses, no study has visually demonstrated protein translocation.

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The bacterial peptidoglycan enclosing the cytoplasmic membrane is a fundamental cellular architecture. The integral membrane protein MurJ plays an essential role in flipping the cell wall building block Lipid II across the cytoplasmic membrane for peptidoglycan biosynthesis. Previously reported crystal structures of MurJ have elucidated its V-shaped inward- or outward-facing forms with an internal cavity for substrate binding.

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Bacteria exposed to environmental stresses often exhibit superior acclimation abilities to environmental change. Acid treatment causes an increase in the cell length of the cyanobacterium Synechocystis sp. PCC6803 under light conditions.

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So far, the molecular mechanisms underlying the acidic-stress responses of plants are complicated and only fragmentally understood. Here, we investigated the mechanisms responsible for acidic-stress acclimation. Previously, DNA microarray analysis identified the sll1558 gene in Synechocystis sp.

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Over 50 ATP-binding cassette (ABC) transporter-related genes are detected in the Synechocystis sp. PCC 6803 genome by genome sequence analysis. Deletion mutants of other substrate-unknown ABC transporter genes were screened for their acid stress sensitivities in a low-pH medium to identify ABC transporters involved in acid resistance.

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Background: Optic neuritis (ON) is unilateral painful optic nerve inflammation in a young healthy female diagnosed by excluding glaucoma. ON onset during pregnancy is rare, with only 2 cases reported to date.

Case Description: A 35-year-old previously healthy parous woman who was pregnant with her second child suffered rapidly progressive visual acuity loss.

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Moyamoya disease usually manifests as ischemic events in childhood, and as more severe hemorrhagic events, including intraventricular hemorrhage, in adults. Recently, the indication for neuroendoscopic surgery has been extended to cast-formation intraventricular hematomas. However, detailed information about the use of neuroendoscopic surgery for the treatment of intraventricular hemorrhage associated with moyamoya disease has not been reported.

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A previously healthy 22-year-old man presented with thoracic outlet syndrome manifesting as Raynaud's phenomenon in the left hand and embolic occlusion of the basilar artery. Three-dimensional computed tomography angiography showed that the left subclavian artery was occluded as it passed over the abnormal first rib. Retrograde propagation of the thrombus from the site of arterial occlusion and/or reflux of embolic material was suspected.

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Background And Purpose: Intratumoral hemorrhage occurs frequently in pituitary macroadenoma and manifests as pituitary apoplexy and recent or old silent hemorrhage. T2*-weighted gradient-echo (GE) MR imaging is the most sensitive sequence for the detection of acute and old intracranial hemorrhage. T2*-weighted GE MR imaging was used to investigate intratumoral hemorrhage in pituitary macroadenomas.

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Since December 2001 we have been conducting a project to isolate and determine entire sequences of mouse KIAA cDNA clones which encode polypeptides corresponding to human KIAA proteins. The ultimate goal of this project is the elucidation of the functions of KIAA proteins. A critical step in this project is the generation of antibodies based on the cDNA sequence information.

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Since the end of 2001, we have conducted a project to isolate and determine entire sequences of mouse cDNA clones which encode the polypeptides corresponding to human KIAA proteins. Towards the ultimate goal of this project to clarify the biological functions of KIAA genes, we have set production of antibodies against mouse KIAA gene products based on their sequence information as the next important stage. As the first step, we developed a high-throughput system utilizing shotgun clones generated during entire sequencing of mouse KIAA cDNAs.

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We here modified a previously reported method for the construction of cDNA libraries by employing an in vitro recombination reaction to make it more suitable for comprehensive cDNA analysis. For the evaluation of the modified method, sets of size-selected cDNA libraries of four different mouse tissues and human brain were constructed and characterized. Clustering analysis of the 3' end sequence data of the mouse cDNA libraries indicated that each of the size-fractionated libraries was complex enough for comprehensive cDNA analysis and that the occurrence rates of unidentified cDNAs varied considerably depending on their size and on the tissue source.

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PRL-releasing peptide receptor (PrRPR) mRNA was expressed in pituitary adenomas but was not detected in patients treated with bromocriptine, a specific agonist of dopamine 2 (D2) receptor. Although medical treatment with bromocriptine is effective for patients with pituitary adenomas, little is known about the molecular mechanisms of gene regulation mediated by D2 receptors. The cloned human PrRPR gene spanned approximately 2.

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A 20-year-old man presented with slowly progressing symptoms indicative of increased intracranial pressure. Two weeks later he underwent surgery for placement of a ventriculoperitoneal shunt. Cytological examination of the patient's cerebrospinal fluid (CSF) revealed atypical cells that contained no detectable melanin deposits, but proved to be immunocytochemically positive for monoclonal antibodies to melanocytic cells (HMB-45) and S-100 protein.

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The clinical outcome of 122 patients with pituitary adenomas treated by microsurgery and/or Gamma Knife radiosurgery (GKRS) was analyzed to evaluate patient selection criteria and the role of GKRS. Sixty-six resections were performed in 59 patients. All tumors were macroadenomas, except for 5 ACTH-producing adenomas.

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Objective And Importance: Rapid correction of hyponatremia is considered the usual cause of central pontine myelinolysis and extrapontine myelinolysis. Little has been reported about mental changes associated with this disorder or its occurrence after transsphenoidal surgery.

Clinical Presentation: A 24-year-old woman suddenly developed markedly abnormal behavior associated with rapid correction of hyponatremia 11 days after undergoing transsphenoidal surgery for a prolactin-secreting pituitary adenoma.

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We measured the amounts of TRH receptor (TRHR) messenger ribonucleic acid (mRNA) in human normal pituitary and pituitary tumors and found a novel transcript of the TRHR gene. Competitive PCR revealed expression of the TRHR mRNA in all pituitary adenomas examined, and its level was variable and similar to that in the normal pituitary. When the C-terminal region was amplified by PCR, an additional short product was observed.

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Although several approaches to the hypothalamus have been used, none is able to give full views of the hypothalamus. The risk of permanent morbidity for hypothalamo-pituitary functions is still high, especially in patients with craniopharyngioma. Basal interhemispheric supra-chiasmal or infra-chiasmal approaches via superomedial orbitotomy were developed for better visualization of the hypothalamus.

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Background: Although treatment results of craniopharyngiomas and germ cell tumors in children have been reported extensively, the relationship between various posttreatment sequelae and the nature of the tumor is not well understood.

Methods: From 1968-94, 47 children with 23 suprasellar germ cell tumors and 24 craniopharyngiomas were treated at Gunma University Hospital, Japan. Forty survivors were assessed with regard to Karnofsky scores, visual scores, final height, final weight, and other endocrine sequelae as long-term functional prognostic indicators.

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We isolated and characterized the gene for the human thyrotropin-releasing hormone receptor. The gene spanned more than 30 kilobases and contained three exons and two introns. Intron 1 exists in the 5'-untranslated region, and intron 2 is more than 25 kilobases in length which interrupts the coding region before the beginning of the putative sixth transmembrane domain.

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Regeneration of transected peripheral nerve with a 10-mm gap encased in a silicone tube was evaluated in the presence of collagen sponge with or without laminin, or with systemic administration of a pyrimidine compound, MS-818. The sciatic nerve of 20 adult rats was transected and the proximal and distal nerve stumps were fixed in a silicone tube. The lumen of the silicone tube was empty, or filled with a collagen sponge alone or with a laminin-soaked collagen sponge.

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Twenty-five gliomas of the cerebral hemisphere in children were examined. Most hemispheric gliomas in children have relatively clear margins and less infiltrative potential. Radiosurgery has a role in the treatment of these tumors in addition to reducing the risk of radiation injuries developing later.

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Four patients with hypothalamic hamartoma were examined by CT and/or MR imaging, immunohistochemistry and electron microscopy. The hamartomas arose from the hypothalamus and extended inferiorly. LH-RH neurons were detected in three cases by immunohistochemistry.

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