Search PubMed⌕ Search

Biomedical subjects

M Matsui

Publications and source records attributed to M Matsui.

At least 73 records · Page 4Linked to original sources
PubMed2000

A Japanese patient with frontotemporal dementia and parkinsonism by a tau P301S mutation.

The authors report a patient carrying a missense mutation in exon 10 of tau that causes a substitution at codon 301 (P301S). Although the patient shares the rapidly progressive frontotemporal dementia of the other reported pedigrees with P301S, the clinical phenotype is unique in that parkinsonism was a major symptom in the early stage and because behavioral symptoms with dementia became prominent 2 years after the onset of the disease. This study substantiates the notion that tau mutations at codon 301 can show various phenotypes.

Adult↗
PubMed2000

Testis- and developmental stage-specific expression of hnRNP A2/B1 splicing isoforms, B0a/b.

Heterogeneous nuclear ribonucleoproteins (hnRNPs) A2 and B1 are abundant nuclear proteins that bind to nascent RNAs synthesized by RNA polymerase II. Previously we had found that the splicing isoforms hnRNP B0a/b, from which the ninth exon of the A2/B1 gene is excluded, are abundantly expressed in testis. We postulated that B0a/b are testis-specific isoforms, and investigated the expression of A2/B1 and B0a/b in rat tissues and in postnatal development of rat testes using RNase protection assay, immunoblotting, and immunohistochemistry. We found that hnRNP B0a/b mRNAs are expressed in several tissues but that the testis alone expresses B0a/b proteins. A sequential study using neonatal rat testes demonstrated that B0a/b mRNAs are produced after 17 days of age, but not translated until 4 weeks of age when round spermatids appear in addition to spermatogonia and spermatocytes. Immunohistochemically, hnRNP A2/B1 isoforms are expressed during spermatogenesis from spermatogonia through round spermatids, whereas the expression of A1 is restricted to spermatogonia. This expression pattern in the rat testis is maintained from birth through adulthood. These results suggest that the expression of the hnRNP A2/B1 gene is partly regulated by a testis-specific post-transcriptional mechanism, and that the products of the A2/B1 gene, especially hnRNP B0a/b, are involved in spermatogenesis.

Animals↗
PubMed2000

Ventricular enlargement in schizophrenia spectrum patients with prodromal symptoms of obsessive-compulsive disorder.

We hypothesized that male patients with schizophrenia spectrum disorders who have prodromal symptoms of obsessive-compulsive disorder (OCD) have ventricular enlargement compared with non-psychotic OCD patients, and that the difference in the ventricular size would offer a clue to the early detection of schizophrenia spectrum disorders. The ventricle-brain ratios (VBRs) in eight male patients with schizophrenia or schizotypal personality disorder (SPD) who had prodromal symptoms of OCD were compared with eight male patients with non-psychotic OCD and 14 normal male comparison subjects using three-dimensional magnetic resonance imaging (MRI). The VBR of the schizophrenia spectrum group was significantly larger than those of the OCD group or comparison subjects. Even the minimum VBR in the schizophrenia spectrum group was larger than the maximum VBR in the OCD group. These results may suggest the usefulness of three-dimensional MRI for early detection of patients with schizophrenia spectrum disorders who manifest OCD symptoms early in the course of the illness.

Adolescent↗
PubMed2000

Multiple functional defects in peripheral autonomic organs in mice lacking muscarinic acetylcholine receptor gene for the M3 subtype.

Muscarinic acetylcholine receptors consist of five distinct subtypes and have been important targets for drug development. In the periphery, muscarinic acetylcholine receptors mediate cholinergic signals to autonomic organs, but specific physiological functions of each subtype remain poorly elucidated. Here, we have constructed and analyzed mutant mice lacking the M(3) receptor and have demonstrated that this subtype plays key roles in salivary secretion, pupillary constriction, and bladder detrusor contractions. However, M(3)-mediated signals in digestive and reproductive organs are dispensable, likely because of redundant mechanisms through other muscarinic acetylcholine receptor subtypes or other mediators. In addition, we have found prominent urinary retention only in the male, which indicates a considerable sex difference in the micturition mechanism. Accordingly, this mutant mouse should provide a useful animal model for investigation of human diseases that are affected in the peripheral cholinergic functions.

Animals↗
PubMed2000

FIN219, an auxin-regulated gene, defines a link between phytochrome A and the downstream regulator COP1 in light control of Arabidopsis development.

Light signals perceived by photoreceptors are transduced to negatively regulate COP1, a key repressor of photomorphogenic development. To identify genes involved in light inactivation of COP1, a genetic screen was employed to identify extragenic modifier mutations of a temperature-sensitive cop1 allele. One suppressor mutation isolated also exhibited a far-red-specific long hypocotyl phenotype in a wild-type background. Further phenotypic analyses of this new mutation, named fin219, suggested that it defines a novel phytochrome A signaling component. Genetic analysis indicated that FIN219 interacts closely with another phytochrome A signaling component, FHY1. Molecular characterization of FIN219 indicated that it encodes a cytoplasmic localized protein highly similar to the GH3 family of proteins and its expression is rapidly induced by auxin. In contrast to its loss-of-function mutant phenotype, overexpression of FIN219 results in a far-red-specific hyperphotomorphogenic response. Our data suggest that FIN219 may define a critical link for phytochrome A-mediated far-red inactivation of COP1 and a possible cross-talk juncture between auxin regulation and phytochrome signaling.

Amino Acid Sequence↗
PubMed2000

Nucleoredoxin, glutaredoxin, and thioredoxin differentially regulate NF-kappaB, AP-1, and CREB activation in HEK293 cells.

Well-established mechanisms for regulation of protein activity include thiol-mediated oxidoreduction in addition to protein-protein interactions and phosphorylation. Nucleoredoxin (NRX), glutaredoxin (GRX), and thioredoxin (TRX) have been shown to act as a potent thiol reductase and reactive oxygen species regulator. They constitute a oxidoreductase superfamily and have been suggested as a candidate operating in the redox regulation of gene expression. We demonstrated here that intracellular localization of these redox molecules differ from each other and that the redox molecules differentially regulate NF-kappaB, AP-1, and CREB activation induced by TNFalpha, PMA, and forskolin and by expression of signaling intermediate kinases, NIK, MEKK, and PKA in HEK293 cells. This is a first report that describes involvement of NRX and GRX and differences from TRX in transcriptional regulation of NF-kappaB, AP-1, and CREB in living cells.

3T3 Cells↗
PubMed2000

Xenopus kielin: A dorsalizing factor containing multiple chordin-type repeats secreted from the embryonic midline.

The midline tissues are important inductive centers of early vertebrate embryos. By signal peptide selection screening, we isolated a secreted factor, Kielin, which contains multiple cys-rich repeats similar to those in chordin (Chd). Expression of Kielin starts at midgastrula stages in the notochord and is detected in the floor plate of neurula embryos. Kielin is induced in mesoderm and in ectoderm by nodal-related genes. Chd is sufficient to activate Kielin expression in mesoderm whereas Shh or HNF-3beta in addition to Chd is required for induction in ectoderm. Kielin has a distinct biological activity from that of Chd. Injection of Kielin mRNA causes dorsalization of ventral marginal zone explants and expansion of MyoD expression in neurula embryos. Unlike Chd, Kielin does not efficiently induce neural differentiation of animal cap ectoderm, suggesting that the activity of Kielin is not simply caused by BMP4 blockade. Kielin is a signaling molecule that mediates inductive activities of the embryonic midline.

Amino Acid Sequence↗
PubMed2000

Neural correlates of memory organization deficits in schizophrenia. A single photon emission computed tomography study with 99mTc-ethyl-cysteinate dimer during a verbal learning task.

Regional cerebral blood flow (rCBF) during a verbal learning task was measured using 99mTc-ethyl-cysteinate dimer and single photon emission computed tomography in 10 patients with schizophrenia and nine normal controls. Verbal repetition was used as a control task. The schizophrenic patients showed failure to spontaneously utilize implicit category information to learn the word lists. In the normal controls, rCBF in the left inferior frontal and left anterior cingulate regions was significantly increased during the verbal learning task, compared with the verbal repetition task. In contrast, there was no significant frontal lobe activation by the verbal learning in the schizophrenic patients. The patients had lower rCBF during the verbal learning task than the controls in the bilateral inferior frontal, left anterior cingulate, right superior frontal, and bilateral middle frontal regions. Activation in the left inferior frontal region was significantly positively correlated with categorical clustering in the task in the controls, but no such correlation was found in the patients. These results indicate that memory organization deficits in schizophrenia may be related to dysfunction in the prefrontal areas, especially in the left inferior frontal region.

Adult↗
PubMed2000

Molecular characterization of a mouse heterogeneous nuclear ribonucleoprotein D-like protein JKTBP and its tissue-specific expression.

The human DNA- and RNA-binding protein JKTBP is a new member of heterogeneous nuclear ribonucleoproteins (hnRNPs) that are involved in mRNA biogenesis. We cloned and characterized a mouse homolog and studied its expression in mouse tissues. The cDNA encoded a 301-residue polypeptide. There is only a single amino acid difference between the mouse and human sequences. Northern blotting indicated ubiquitous but varied expressions of approximately 1.4 and 2.8kb mRNAs in various tissues. Immunoblotting indicated that the amounts of protein of about 38kDa were higher in the brain and testis than in other tissues. An additional protein of about 53kDa was found in the brain and testis. Germ cell-deficient W/W(v) mutant mice and aged mice had the reduced amounts of JKTBP in the testes. Immunohistochemical staining indicated cell type-specific expression of JKTBP in tissues: neurons and spermatocytes displayed strong signal intensities. The signals were confined to the nucleus. The amount of 38kDa JKTBP was estimated to be approximately 1.3x10(7) molecules per HL-60 cell. These results indicate that JKTBP is an abundant, highly conserved nuclear protein.

Animals↗
PubMed2000

Effect of human plasma-type platelet-activating factor acetylhydrolase in two anaphylactic shock models.

The effect of human recombinant plasma-type platelet-activating factor (PAF) acetylhydrolase was examined in two murine models, PAF-induced death and active anaphylactic models. In the PAF-induced death model where mice were injected intravenously with 40 microg/kg of PAF, the administration of PAF acetylhydrolase reduced mortality in a dose-dependent manner, showing complete prevention of mortality at 1.0 mg/kg. Myeloperoxidase activity, the marker for neutrophils, was increased in the lung by PAF injection, and the PAF acetylhydrolase treatment significantly reversed the increase in myeloperoxidase activity. As in the PAF-induced model, PAF acetylhydrolase also decreased mortality in the active anaphylactic shock model where bovine serum albumin was injected intravenously to mice previously immunized with bovine serum albumin. The protective effect of PAF acetylhydrolase on mortality in this model was significant at 1.0 mg/kg. These results suggest that PAF is an important mediator in the lethality of systemic anaphylaxis, and that PAF acetylhydrolase may be beneficial for treatment of anaphylactic shock.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2000

Nucleotide variations amongst V(H)Genes of AMA-producing B cell clones in primary biliary cirrhosis.

Primary biliary cirrhosis, a chronic liver disease characterized by progressive inflammatory destruction of intrahepatic bile ducts, is also characterized by the presence of antimitochondrial antibodies (AMA). The predominant autoantibody is directed at the E2 component of pyruvate dehydrogenase (PDC-E2). Recent studies of this autoantibody response have analysed immunoglobulin-variable regions of human monoclonal antibodies and provided evidence for antigen-driven clonal selection. However, the number of clones analysed has been very limited and the presence of somatic mutations not formally proven. In this study, we took advantage of three stable B cell lines producing human IgG anti-PDC-E2 mAbs from a patient with PBC. We analysed the V(H)and V(L)gene structure of these reagents and, in addition, analysed 10 V(H)-D and D-J(H)sequences over a period of nearly 3 years. The expressed Ig V regions of the heavy chain (V(H)) and the light chain (V(L)) genes of mAb18, mAb37, and mAb82 utilized the V(H)III-VlambdaI, V(H)IV-VlambdaIII, and V(H)IV-V(k)IV gene families, respectively. The utilized gene elements were Ig gene elements that were found frequently in other antibodies with different specificity and affinity. Presence of somatic point-mutations was confirmed in mAb82 by comparison of the expressed V(H)gene sequence with that of corresponding germline V(H)gene obtained from the granulocyte genomic DNA of the same patient. Interestingly, clonally related B cells were consistently found throughout the observation period and nucleotide variations among the V(H)genes were very few, ranging from 0.19 to 0.72% per base. These findings suggest that long-lived B cell clones can exist and may contribute, at least in part, to maintenance of autoantibodies in humans.

Amino Acid Sequence↗
PubMed2000

A diagnostic method for suspected Alzheimer's disease using H(2)15O positron emission tomography perfusion Z score.

We developed cerebral perfusion Z score map (Z map) images using H(2)15O and positron emission tomography (PET), and examined their use in diagnosing Alzheimer's disease (AD). Cerebral blood flow (CBF) images were obtained using the PET and H(2)15O autoradiographic method. The best region for normalising the CBF value to remove individual variantion was determined. Then CBF images were transformed to Talairach's standard space, and each pixel value of an individual's image set was normalized to the mean value of the sensorimotor area. Based on the CBF images of 20 normal volunteers, normative mean and standard deviation (SD) CBF images were constructed. Then, each pixel value of the axial CBF images in 28 patients with probable AD and 10 further normal volunteers was converted to a Z score (Z = [normal mean--individual value]/normal SD). A Z map, showing pixels exceeding a threshold of Z score > 2 on MRI of standardised anatomical space was demonstrated. These 38 Z maps were interpreted by four radiologists. When regions in the temporoparietal area were found with Z scores > 2, the subject was diagnosed as having AD. A receiver operating characteristic (ROC) analysis was performed to compare the conventional CBF images and Z maps. The diagnostic performance of the Z map was superior to that of visual inspection of conventional CBF images (mean areas under the ROC curve of the four radiologists were 0.946 and 0.584, respectively). These results indicate that a Z map obtained in this way is superior to conventional PET for diagnosing AD.

Aged↗
PubMed2000

Therapeutic effect of transtrochanteric rotational osteotomy and hip arthroplasty on quality of life of patients with osteonecrosis.

We reviewed 37 patients with avascular necrosis of the femoral head (ANF). There were 23 men and 14 women with a mean age of 36 years at the time of the operation. The duration of follow-up was 9 years. Twenty patients had undergone transtrochanteric rotational osteotomy (TRO) and 17, hip arthroplasties. Assessment of their quality of life (QoL) was performed using the Rosser Index Matrix for disability and distress. Concerning TRO, the mean preoperative and postoperative QoL scores were 0.944 and 0.957, respectively. Twelve patients exhibited increases and 7 patients decreases in their scores. Regarding the arthroplasty, the mean preoperative and postoperative QoL scores were 0.949 and 0.998, respectively. All patients showed increases in QoL scores after arthroplastic surgery. Concerning heavy manual work, all five of those patients returned to their preoperative occupations. These findings suggest that hip arthroplasty has more reliable therapeutic effects than TRO on QoL improvement for patients with ANF.

Adult↗
PubMed2000

Intramolecular electron-transfer reaction within a diprotein complex of cytochrome c with ferrylmyoglobin modified with diethylenetriaminepentaacetic acid.

Horse heart metmyoglobins modified with diethylenetriaminepentaacetic acid, metMb(DTPA)n (n=1, 2, 4, and 5), were characterized by a MALDI-TOF mass spectrometry, amino-acid sequence analysis, and UV-Vis and CD spectroscopies. The DTPA-binding sites on metMb were Lys47, Lys50, Lys87, Lys145, and Lys147 for metMb(DTPA)5, Lys47, Lys87, Lys145, and Lys147 for metMb(DTPA)4, Lys87 and Lys145 for metMb(DTPA)2, and Lys87 for metMbDTPA, respectively. The modified metMb(DTPA)n showed cytochrome c peroxidase-like activity more efficiently than native metMb: metMb(DTPA)5>metMb(DTPA)4>metMb(DTPA)2> metMbDTPA approximately equals native metMb. The first-order rate constants for the reactions of ferrylMb(DTPA)n (n=2, 4, and 5) with reduced cytochrome c [cyt c(II)] were saturated with concentrations of cyt c(II), suggesting that the electron transfer (ET) occurs within a diprotein complex. The intramolecular ET rate constants in the diprotein complex increased with increasing the number of DTPA ions. The reactions of native ferrylMb and ferrylMbDTPA with cyt c(II) obeyed a second-order rate law. A possible ET mechanism is proposed; cyt c(II) binds the DTPA-linked anionic patch around Lys87, Lys145, and Lys147 region of ferrylMb(DTPA)n.

Animals↗
PubMed2000

Tumor necrosis factor, tumor necrosis factor receptors type 1 and 2, lymphotoxin-alpha, and HLA-DRB1 gene polymorphisms in human T-cell lymphotropic virus type I associated myelopathy.

We studied tumor necrosis factor (TNF), lymphotoxin-alpha (LT-alpha), and TNF receptors type 1 (TNFR-1) and type 2 (TNFR-2) gene polymorphisms as well as HLA class II DRB1 alleles in Japanese patients with human T-cell lymphotropic virus type I (HTLV-I) associated myelopathy (HAM) (n = 51), patients with adult T-cell leukemia/lymphoma (ATL) (n = 48), asymptomatic HTLV-I carriers (n = 50), and HTLV-I seronegative, normal controls (n = 112). There were significant differences between HAM patients and normal controls in the distributions of TNF promoter region polymophism at position --857, the LT-alpha gene NcoI polymorphism, and the T-G substitution in exon 6 of the TNFR-2 gene. The distribution of the NcoI polymorphism of the LT-alpha gene was also significantly different between HAM patients and asymptomatic HTLV-I carriers. In contrast, we failed to detect any difference in the frequency of DRB1, TNF promoter at position --1031, --863, or the TNFR-1 promoter --383 polymorphism. The results suggest that the TNF/LT-alpha gene region within the HLA class III of chromosome 6 and the TNFR-2 gene region located on chromosome 1p36 might contribute to susceptibility to HAM, and that aberrant expression or function of these cytokines and the receptor could be involved in the development of HAM.

Alleles↗
PubMed2000

Batrachology of Japan and adjacent regions - a systematic review.

As is the case with most other organisms, studies of amphibians started with systematics as the basis for many other biological fields, but systematics itself has endured a slower progress than other fields of biology have enjoyed for a long time. Nevertheless, philosophical and methodological 'revolutions' in the past 30 years, combined with more recent progress in biochemical and molecular techniques, have been forcing current systematics into a great change. Stejneger's (1907) monumental book, the first thorough review of amphibians from Japan and adjacent regions, was published nearly a century ago, and since then, the increase in number of areas that have been closely surveyed, together with the application of new theories and methods, have greatly enlarged our knowledge of the amphibian fauna in this region. For example, extensive experiments by the Hiroshima School using artificial hybridization techniques greatly contributed to our understandings of relationships among some groups of amphibians that had been taxonomically confusing. In addition to this, new species discovered by more detailed field surveys in a wider area and cryptic species revealed by analyses of isozymes and acoustic properties have made for a great increment in the number of taxa in this region. Further, analyses of DNA sequences now enable us to infer the affinities of taxa with few phylogenetically informative phenotypic properties, and the resultant phylogenetic hypotheses further contribute to our understandings of biogeography and many other issues on amphibian evolution. From these advances, it has been clarified that the amphibian species diversity is far greater than was previously expected, which in turn means a high endemism within particular regions. It is expected that future studies will also reveal exact systematic relationships of wide-ranging species, both those occurring within this region and those extending outside of it. For that purpose, international and interdisciplinary studies are indispensable. But what is also necessary is to conserve amphibian populations so that they will not disappear before their true relationships are realized. Knowledge of systematics among young amphibian biologists is also a matter of high priority.

Amphibians↗
PubMed2000

Allozymic variation of Hynobius kimurae Dunn (Amphibia, Caudata).

An electrophoretic survey was conducted to examine genetic divergence among 21 populations of a lotic-breeding salamander Hynobius kimurae from Honshu, Japan. Genetically H. kimurae proved to be specifically distinct from H. naevius. Hynobius kimurae is divided genetically into two groups of local populations, and the five populations from the eastern area are genetically distinct from the remaining populations of the central and western areas. Less prominent genetic differentiation was revealed between the western and central populations. Separation of the eastern and central-western groups are discussed in relation to the formation of the Japanese mainland.

Animals↗