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Biomedical subjects

S Tsuji

Publications and source records attributed to S Tsuji.

At least 217 records · Page 12Linked to original sources

14-3-3 protein eta chain gene (YWHAH) polymorphism and its genetic association with schizophrenia.

Recent genetic analyses have suggested a linkage between schizophrenia and the chromosomal region 22q12-q13. 14-3-3 protein, abundant in the brain, mediates interactions between diverse molecules of biological activities; its gene was recently mapped to chromosome 22q12.1-q13.1. We therefore investigated allele frequencies of a variable number of tandem repeat (VNTR) in the 5'-noncoding region of the 14-3-3 eta chain gene in controls and schizophrenics. The frequencies of the two-repeat allele were significantly higher (P < 0.05) in the schizophrenics, and particularly in those with onset before age 22 (early-onset schizophrenics, P < 0.02), than in the controls. The odds ratio was significantly increased in the early-onset schizophrenics homozygous for the two-repeat allele (OR = 3.3, 95% CI = 1.1-9.7). The 14-3-3 eta chain gene is a potential susceptibility gene for schizophrenia, and particularly for early-onset schizophrenia.

14-3-3 Proteins↗

Human MD-1 homologue is a BCG-regulated gene product in monocytes: its identification by differential display.

BCG-CWS is a therapeutically potent immune activator which improves the prognosis of cancer patients. However, the targeting effector cells and molecules for BCG-CWS in the human immune system have not been determined. Here, we found that BCG-CWS activates human monocytes and concomitantly down-regulates expression of a human homologue of chicken MD-1 in the activated monocytes by differential display. According to a previous study, MD-1 forms a complex with the Toll family protein RP-105 on murine B cell lines to facilitate its stable expression. Thus, MD-1 may participate in regulation of innate immune activation on human monocytes. Our results, taken together with these recent findings regarding Toll family proteins, suggest that BCG-CWS acts on monocytes to modulate the human innate immune system via regulation of Toll family proteins.

Amino Acid Sequence↗

Cytotoxic T lymphocyte-mediated cell death in paraneoplastic sensory neuronopathy with anti-Hu antibody.

Paraneoplastic sensory neuronopathy (PSN) has been shown to harbor characteristic anti-neuronal autoantibody 'anti-Hu' in their sera and cerebrospinal fluid. Creation of animal models exhibiting clinical or pathological features seen in PSN by means of passive transfer of anti-Hu positive IgG has not been achieved. Although, anti-Hu antibody was shown to induce neuronal cell lysis in vitro, this result has not been reproduced so far. Since prominent T cell infiltration are seen in the central nervous system and posterior spinal ganglion of the patients with anti-Hu syndrome, we studied cytotoxic T cell (CTL) activity in peripheral mononuclear cells from a patient with PSN harboring anti-Hu antibody. The activated CD8+ T cells from the patient's venous blood were shown to lyse her own fibroblasts which were incubated with interferon-gamma to induce HLA class I molecules on their surface and the recombinant HuD protein was injected into the cells by microinjector. This is the first report showing the existence of CTL in a patient with PSN.

Autoantibodies↗

Systematic analysis of N-linked sugar chains from whole tissue employing partial automation.

A partially automated technique for the isolation and characterization of N-linked sugar chains from glycoproteins of crude tissue samples is established. The N-linked sugar chains from the acetone-extracted tissues are made free by a process of hydrazinolysis and subsequently N-acetylated by GlycoPrep 1000 (Oxford Glycosystems). These free sugar chains are further converted to pyridylamino derivatives by GlycoTag (Takara). Characterization of these sugar chains is achieved by a combination of HPLC columns using a highly sensitive fluorescence detector at femtomole levels. Tissue sample can be successfully pyridylaminated and analyzed to give highly reproducible results with consistent yield, requiring fewer purification steps, minimum skills, and less time. Moreover, fixed tissues can also be analyzed employing this technique, giving a similar sugar chain pattern compared to normal tissue samples. Using this method we show that the pattern of N-linked sugar chains present in human sera or in one small region of brain is strikingly similar among the different individuals. However, the absence of a highlighted peak in one of the samples suggests this method can be extrapolated to identify changes, if any, associated with disorders such as inflammation or cancer. Furthermore, this two-dimensional display of sugar chains would discover the function-specific molecules as we see in proteins.

Animals↗

Rabbit experimental sensory ataxic neuropathy: anti-GD1b antibody-mediated trkC downregulation of dorsal root ganglia neurons.

We previously reported experimental sensory neuropathy in rabbit induced by the immunization of ganglioside GD1b. The major pathological change in diseased rabbits was degeneration of primary sensory neurons with central axons extending to the dorsal column of the spinal cord. The loss of primary sensory neurons that mediate proprioceptive sensation prompted us to investigate the expression of trkC in dorsal root ganglia (DRG) because this type of neuron is thought depend mainly on neurotrophin-3-mediated trkC signaling. Northern blotting analysis revealed markedly reduced expression of trkC in DRG of diseased rabbits in acute phase. This result together with the absence of lymphocytic infiltration in DRG of diseased rabbits at any stage suggests the anti-GD1b antibody-mediated downregulation of trkC expression could be one of the pathogenesis of this experimental sensory ataxic neuropathy.

Animals↗

Dorsal root ganglia neuron-specific promoter activity of the rabbit beta-galactoside alpha1,2-fucosyltransferase gene.

The rabbit H-blood type alpha1,2-fucosyltransferase (RFT-I), gene and its biosynthetic products, H antigens (Fucalpha1,2Galbeta), are abundantly expressed in a subset of dorsal root ganglia (DRG) neurons. To investigate the regulatory mechanisms for the RFT-I gene expression, we determined the genomic structure and promoter activity of this gene. PCR amplification of the 5' cDNA end analysis revealed two transcriptional start sites, 498 and 82 nucleotides upstream of the translational initiation codon, the latter site yielding a major 3.1-kb transcript specifically expressed in DRG, as revealed by Northern blotting. Promoter analysis of the 5'-flanking region of the RFT-I gene using a luciferase gene reporter system demonstrated strong promoter activity in PC12 cells, which express the rat H-type alpha1,2-fucosyltransferase gene, and Neuro2a mouse neuroblastoma cells. Deletion analysis revealed the 704-base pair minimal promoter region flanking the translational initiation codon, for which two distinct promoter activities were detected and differentially used in PC12 and Neuro2a cells. The minimal promoter region contained a GC-rich domain (GC content 80%), in which a Sp1 binding sequence and a GSG-like nerve growth factor-responsive element were found, but lacked TATA- and CAAT-boxes. Promoter analysis with a primary culture of DRG neurons demonstrated that the minimal promoter region of the RFT-I gene was sufficient for the expression of a reporter gene in DRG neurons. We conclude that the TATA-less GC-rich minimal promoter region of the RFT-I gene controls DRG small neuron-specific expression of the RFT-I gene.

Animals↗

Accumulation of neurofilaments and SOD1-immunoreactive products in a patient with familial amyotrophic lateral sclerosis with I113T SOD1 mutation.

OBJECTIVE: To report neuropathologic features of argyrophilic inclusions in the anterior horn cells, motor cortex Betz cells, and neurons of the medullary reticular formation, spinal posterior horn, and Clarke column in a Japanese case of familial amyotrophic lateral sclerosis with I113T substitution in exon 4 of the copper-zinc superoxide dismutase (SOD1) gene. METHODS AND RESULTS: These inclusions were stained pale pink on the hematoxylin-eosin stain and dark on the Bielschowsky stain. They were positive for antibodies to phosphorylated neurofilaments, ubiquitin, and SOD1. On electron microscopy, they consisted of abundant intermediate filaments of 10 to 20 nm in diameter with disordered array indicating neurofilaments. CONCLUSION: These findings suggest that the I113T mutation induces accumulation of neurofilaments and SOD1 in the central nervous system neurons.

Aged↗

Mutational analysis and genotype-phenotype correlation of 29 unrelated Japanese patients with X-linked adrenoleukodystrophy.

BACKGROUND: X-linked adrenoleukodystrophy (ALD) is an inherited disease characterized by progressive neurologic dysfunction, occasionally associated with adrenal insufficiency. The classic form of ALD usually has onset in childhood (childhood cerebral ALD), with rapid neurologic deterioration leading to a vegetative state. Adult-onset cerebral ALD also presents with rapidly progressive neurologic dysfunction. Milder phenotypes such as adrenomyeloneuropathy and Addison disease only also have been recognized. Despite discovery of the causative gene, a molecular basis for the diverse clinical presentations remains to be elucidated. OBJECTIVES: To conduct mutational analyses in 29 Japanese patients with ALD from 29 unrelated families, to obtain knowledge of the spectrum of mutations in this gene, and to study genotype-phenotype correlations in Japanese patients. METHODS: The 29 patients comprised 13 patients with childhood cerebral ALD, 11 patients with adult-onset cerebral ALD, and 5 patients with adrenomyeloneuropathy. We conducted detailed mutational analyses of 29 unrelated Japanese patients with ALD by genomic Southern blot analysis and direct nucleotide sequence analysis of reverse transcriptase-polymerase chain reaction products derived from total RNA that was extracted from cultured skin fibroblasts, lymphoblastoid cells, or peripheral blood leukocytes. RESULTS: Three patients with adult-onset cerebral ALD were identified as having large genomic rearrangements. The remaining 26 patients were identified as having 21 independent mutations, including 12 novel mutations resulting in small nucleotide alterations in the ALD gene. Eighteen (69%) of 26 mutations were missense mutations. Most missense mutations involved amino acids conserved in homologous gene products, including PMP70, mALDRP, and Pxa1p. The AG dinucleotide deletion at position 1081-1082, which has been reported previously to be the most common mutation in white patients (12%-17%), was also identified as the most common mutation in Japanese patients (12%). All phenotypes were associated with mutations resulting in protein truncation or subtle amino acid changes. There were no differences in phenotypic expressions between missense mutations involving conserved amino acids and those involving nonconserved amino acids. CONCLUSIONS: There are no obvious correlations between the phenotypes of patients with ALD and their genotypes, suggesting that other genetic or environmental factors modify the phenotypic expressions of ALD.

Adolescent↗

A novel mutation in the gene for the adult skeletal muscle sodium channel alpha-subunit (SCN4A) that causes paramyotonia congenita of von Eulenburg.

BACKGROUND: Paramyotonia congenita (PMC) of von Eulenburg is an autosomal dominant muscular disease characterized by exercise- and cold-induced myotonia and weakness. To date, 18 missense mutations in the adult skeletal muscle sodium channel alpha-subunit (SCN4A) gene have been identified to cause a spectrum of muscular diseases, including PMC of von Eulenburg, PMC without cold paralysis, potassium-aggravating myotonia, and hyperkalemic periodic paralysis. However, no obvious correlations can be made between the location or nature of amino acid substitutions in SCN4A and its clinical phenotypes. OBJECTIVE: To describe clinical and genetic features of a family with PMC of von Eulenburg. RESULTS: A Japanese family with cold-induced myotonia and weakness was diagnosed as having PMC of von Eulenburg. This phenotype was identified to be caused by a novel mutation that substituted a glutamic acid residue for a highly conserved glycine residue in the fourth transmembrane segment (S4) of domain IV. This predicted a decrease in positive charge specific for the S4. CONCLUSION: In addition to the G1456E identified in this study, 4 mutations that cause a decrease in positive charge in the S4/D4 are associated with the phenotype of PMC of von Eulenburg. This provides an important genotype-phenotype correlation in sodium channelopathies.

Adult↗

Familial paroxysmal dystonic choreoathetosis: clinical findings in a large Japanese family and genetic linkage to 2q.

BACKGROUND: Paroxysmal dystonic choreoathetosis (PDC) is a rare familial movement disorder that has been mapped to chromosome 2q31-36. OBJECTIVE: To study the first Japanese family with PDC clinically and genetically. PATIENTS AND METHODS: We studied a large Japanese family in which at least 17 members in 6 generations have been affected by PDC. We interviewed and examined 26 family members, 8 of whom revealed choreoathetosis-like and dystonialike involuntary movement and 1 of whom revealed no involuntary movement but only muscle stiffness such as the aura of paroxysmal dystonic choreoathetosis (PDC). Genetic linkage studies of this family were carried out with polymorphic DNA markers. RESULTS: The attacks of involuntary movement or muscle stiffness were precipitated by ovulation, menstruation, emotional stress, or caffeine or alcohol ingestion. Magnetic resonance imaging of the brain revealed no abnormalities. Clonazepam therapy was effective for reducing the attacks, and ingestion of garlic was believed by patients to be effective for softening the attacks. An affected woman with only muscle stiffness showed remission after hysterectomy for hysteromyoma. This woman also had the disease haplotype and transferred it to her typical PDC-affected daughter. Maximal pairwise logarithm of odds scores exceeding 2.00 were obtained at D2S2250, D2S1242, D2S377, D2S2148, and D2S126. The PDC gene was demonstrated by linkage analyses to be located in a 15.3-centimorgan interval lying between D2S371 and D2S339 based on pairwise and multipoint logarithm of odds scores and obligate recombination events in affected individuals. CONCLUSIONS: Linkage of PDC to chromosome 2q32-36 was confirmed in a Japanese family. The clinical characterizations of this family with PDC include that ovulation seems also to be a precipitating factor of the attacks and that hysterectomy seems to be effective for softening the attacks. Although low-dose clonazepam treatment was most effective, garlic use was believed by affected members to be effective for softening the attacks. Furthermore, based on the results of clinical and genetic analyses, we suggest that muscle stiffness without involuntary movement may represent a forme fruste of PDC.

Athetosis↗

Dizygotic twin sisters with myelokathexis: mechanism of its neutropenia.

Dizygotic twin sisters were first found to have neutropenia at 1 year of age when evaluated for recurrent pulmonary infections. Since then they have remained neutropenic (0.05 approximately 0.5 x 10(9)/l). Despite of their neutropenia, myeloid hyperplasia was evident on a marrow smear examination, and a number of cells were hypersegmented with fine interlobular bridging with chromatin strands and cytoplasmic vacuolation. Electron microscopy showed apoptotic cells with condensed nuclei and apoptotic bodies in the cytoplasm. Although life span, hydrogen peroxide production, phagocytosis, spreading, and chemotaxis of peripheral neutrophils were normal, the survival of bone marrow neutrophils in both infants was markedly decreased when compared with that of normal bone marrow neutrophils. During the bone marrow culture apoptotic neutrophils were observed at an earlier stage in both patients than in normal controls, biochemically and morphologically. Morphology of bone marrow neutrophils in both patients resembled that of cultured control bone marrow neutrophils. Peripheral neutropenia and appearance of characteristic neutrophils in the bone marrow in myelokathexis are considered to be an expression of apoptosis of bone marrow neutrophils.

Apoptosis↗

A de novo splice donor site mutation causes in-frame deletion of 14 amino acids in the proteolipid protein in Pelizaeus-Merzbacher disease.

Pelizaeus-Merzbacher disease (PMD) is a leukodystrophy associated with mutations in the proteolipid protein (PLP) gene. Jimpy is a mouse model of human PMD, and a splice site mutation in Jimpy causes the deletion of exon 5 from the PLP mRNA, producing a truncated form of PLP. We describe a de novo point mutation at the 5' splice donor site of exon 5 in a 17-year-old male with PMD, which results in the skipping of 42 base pairs of exon 5. The mutation removes only 14 amino acids in-frame of PLP. This is a novel splice donor site mutation in the human PLP gene. Moreover, the results indicate that the 14-amino acid deletion in the PLP is responsible for oligodendrocyte cell death and the development of PMD.

Adolescent↗

Immunohistochemical analysis of cyclooxygenase-2 expression in pancreatic tumors.

BACKGROUND: A considerable amount of evidence collected from several experimental systems and clinical studies with nonsteroidal Anti-inflammatory drugs (NSAIDs) indicates that Cox-2 may play a major role in colorectal tumorigenesis, but little information about Cox-2 expression in pancreatic tumors is available. In this study, we investigated Cox-2 expression by means of both immunohistochemical analysis and immunoblot analysis in pancreatic tumors. METHODS: Fifty invasive ductal adenocarcinomas and 26 intraductal papillary-mucinous tumors (IPMTs) were used for immunohistochemical analysis, and five pancreatic cancer tissues and five pancreatic cancer cell lines for immunoblot analysis. RESULTS: Cox-2 was expressed in 72% of the invasive ductal adenocarcinomas, 31% of intraductal papillary-mucinous adenocarcinomas, and none of intraductal papillary-mucinous adenomas. The expression rate of Cox-2 in intraductal papillary-mucinous adenocarcinomas was significantly higher than that in intraductal papillary-mucinous adenomas, and that in invasive ductal adenocarcinomas was significantly higher than that in intraductal papillary-mucinous carcinomas. However, there was no significant correlation between Cox-2 expression and the prognosis and clinicopathological factors. Immunoblot analysis identified Cox-2 in all of pancreatic cancer tissues and 60% of cell lines. CONCLUSION: The biological role of cyclooxygenase-2 (Cox-2) in carcinoma cells should be investigated with reference to the cancer progression of the pancreas.

Adenocarcinoma↗

Studies of the candidate genes in X-linked congenital cerebellar hypoplasia.

A gene for X-linked congenital cerebellar hypoplasia was recently localized to chromosome Xp11.21-q24. This region comprises several brain-specific genes responsible for various neurological disorders, including the proteolipid protein (PLP), doublecortin, and PAK3 genes. We screened these genes for mutations in patients with X-linked congenital cerebellar hypoplasia and found no pathogenic nucleotide changes or gene dose alterations. These findings allow the ruling out of PLP, doublecortin, and PAK3 as the disease-causing genes in this hereditary neurological syndrome.

Cerebellum↗

Smooth muscle layer-specific variations in the autonomic innervation of bovine myometrium.

1. To clarify the autonomic innervation regulating longitudinal muscle (LM) and circular muscle (CM) motility in the bovine uterus, functional (nerve stimulation, adrenergic drug responsiveness) and biochemical studies (catecholamine content, radioligand binding) were conducted on parous luteal-phase myometrium. 2. Electrical field stimulation (EFS; 60 V, 0.5-msec duration) caused tetrodotoxin (1 microM)-sensitive contractions in a frequency-dependent manner (0.5-20 Hz) in both LM and CM layers. 3. The EFS-induced LM contractions were potentiated by propranolol and conspicuously decreased by phentolamine, yohimbine, idazoxan or guanethidine, but were unaffected by prazosin or atropine. 4. On the other hand, CM contractions were only slightly decreased by phentolamine, idazoxan, yohimbine and guanethidine, but were insensitive to propranolol, prazosin or atropine. 5. The noradrenaline content in LM was about five times higher than that in CM. 6. Noradrenaline, adrenaline, clonidine, xylazine, UK14,304 and phenylephrine caused concentration-dependent contractions of both smooth muscle layers. 7. Clonidine, UK14,304 and xylazine were more potent contractile agents than noradrenaline and phenylephrine. 8. The contractile response to noradrenaline was competitively antagonized by yohimbine, but not by prazosin. 9. Binding studies using [3H]-prazosin and [3H]-rauwolscine revealed that the bovine myometrium contained both alpha1- and alpha2-adrenoceptors, but the alpha2-type receptor was dominant in both LM (94% of alpha-adrenoceptors) and CM (88%) layers. 10. The distribution of alpha-adrenoceptors was muscle layer-specific; that is, the concentration of alpha1-receptors in LM was the same as in CM, but the concentration of alpha2-receptors in LM was 2.6 times higher than that in CM. 11. The results of the present study indicate that there are layer-specific variations in the functional innervation of the parous bovine myometrium (exclusive adrenergic innervation in LM and adrenergic [minor] plus nonadrenergic, noncholinergic innervation [major] in CM), and that alpha2-adrenoceptors, which were responsive to the excitatory response of endogenous and exogenous noradrenaline, were dominant in both muscle layers of the bovine myometrium.

Adrenergic alpha-Agonists↗

Nuclear accumulation of truncated atrophin-1 fragments in a transgenic mouse model of DRPLA.

Dentatorubral and pallidoluysian atrophy (DRPLA) is a member of a family of progressive neurodegenerative diseases caused by polyglutamine repeat expansion. Transgenic mice expressing full-length human atrophin-1 with 65 consecutive glutamines exhibit ataxia, tremors, abnormal movements, seizures, and premature death. These mice accumulate atrophin-1 immunoreactivity and inclusion bodies in the nuclei of multiple populations of neurons. Subcellular fractionation revealed 120 kDa nuclear fragments of mutant atrophin-1, whose abundance increased with age and phenotypic severity. Brains of DRPLA patients contained apparently identical 120 kDa nuclear fragments. By contrast, mice overexpressing atrophin-1 with 26 glutamines were phenotypically normal and did not accumulate the 120 kDa fragments. We conclude that the evolution of neuropathology in DRPLA involves proteolytic processing of mutant atrophin-1 and nuclear accumulation of truncated fragments.

Adolescent↗