Biomedical subjects

S Tsuji

Publications and source records attributed to S Tsuji.

At least 199 records · Page 11Linked to original sources

PubMed2000

[Studies on rejected food blue no. 1 (Brilliant Blue FCF) aluminum lake].

One of the brilliant blue FCF aluminum lakes (B-1Als) in the official inspection of coal-tar dyes in fiscal year 1999 was rejected. The results of tests of the rejected sample were submitted to JSFA-VII except for a violet sub-spot by paper chromatography. Its visual spectrum had same lambda max 630 nm as B-1 standard and a very small shoulder at 580 nm in comparing to B-1 standard. HPLCs detected at 625 nm of subsidiary dyes and 580 nm were performed on the rejected sample of B-1Al. A sub-V in HPLCs of th sample which eluted at 37.6 min had its relative peak area of 7.9% at 580 nm and 0.24% at 625 nm, and its peak ratio (at 580 nm/at 625 nm) was extremely large. Consequently, it was presumed that the sub-V in those HPLCs corresponded to the violet sub-spot in paper chromatography.

Benzenesulfonates↗

PubMed2000

[Estimated production by the official inspection of coal-tar dyes (including dye aluminum lakes) in fiscal year 1999].

There were 260 official inspections of coal-tar dyes and their lakes in fiscal year 1999, and 259 of the lots qualified, one of the 8 samples of Food Blue No. 1 aluminum lakes was rejected. The quantity of coal-tar dyes that passed inspection in Japan in fiscal year 1999 reached 151.9 tons. Coal-tar dye production is estimated by month and by manufacturer. The food coal-tar dye produced in the largest quantity was Food Yellow No. 4, accounting for 44.2% during this period.

Chemical Industry↗

PubMed1999

Mutational analysis of the anion exchanger 3 gene in familial paroxysmal dystonic choreoathetosis linked to chromosome 2q.

Familial paroxysmal dystonic choreoathetosis (PDC) is an autosomal dominant neurological disorder characterized by episodes of involuntary movement precipitated by caffeine, alcohol, or emotional stress. The locus for PDC has recently been mapped to chromosome 2q32-36, but its causative gene has not yet been identified. PDC is most likely a kind of channelopathy, as suggested by the fact that other paroxysmal neurological disorders are caused by various ion channel mutations. Although no ion channel is located in this candidate region, anion exchanger 3 (AE3) has been mapped to 2q36 and has also been reported to be the most promising candidate gene of PDC. In this study we performed sequencing of the coding region of the AE3 gene in patients with familial PDC linked to chromosome 2q and excluded the AE3 gene as the causative gene for PDC. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:733-737, 1999.

Amino Acid Sequence↗

PubMed1999

A novel glycosyltransferase with a polyglutamine repeat; a new candidate for GD1alpha synthase (ST6GalNAc V)(1).

The fifth type GalNAcalpha2,6-sialyltransferase (mST6GalNAc V) was cloned from a mouse brain cDNA library. mST6GalNAc V exhibited type II transmembrane topology containing a polyglutamine repeat, which showed 42.6% and 44.8% identity to mouse ST6GalNAc III and IV, respectively. Northern blot analysis revealed that the mST6GalNAc V gene was specifically expressed in forebrain and cerebellum. mST6GalNAc V exhibited GD1alpha synthetic activity from GM1b the same as mST6GalNAc III and IV. The activity ratio of GM1b toward fetuin and the expression pattern were completely different among the three ST6GalNAcs. Interestingly, the polyglutamine repeat number was different from that of inbred mice. We report the first glycosyltransferase with a polymorphic polyglutamine repeat.

Amino Acid Sequence↗

PubMed1999

Reduction of tyrosine kinase B and tyrosine kinase C inductions by treatment with neurotrophin-3 after transient middle cerebral artery occlusion in rat.

Infarct volume and immunoreactivities for trkB and trkC in rat brain were compared at 24 h after 90 min of transient middle cerebral artery occlusion (MCAO) between animal groups with or without neurotrophin-3 (NT-3, 10 microg/250 g animal). Treatment of rat brain with topical application of NT-3 significantly reduced infarct volume (P = 0.02) and trkB and trkC inductions. These data suggest that NT-3 reduced the ischemic injury along with the reduction of trkB and trkC inductions.

Administration, Topical↗

PubMed1999

Occurrence of D-amino acids in a few archaea and dehydrogenase activities in hyperthermophile Pyrobaculum islandicum.

The contents of D-enantiomers of serine, alanine, proline, glutamate (glutamine) and aspartate (asparagine) were examined in the membrane fractions, soluble proteins and free amino acids from some species of archaea, Pyrobaculum islandicum, Methanosarcina barkeri and Halobacterium salinarium. Around 2% (D/D+L) of D-aspartate was found in the membrane fractions. In the soluble proteins, the D-amino acid content was higher in P. islandicum than that in the other archaeal cells: the concentrations in P. islandicum were 3 and 4% for D-serine and D-aspartate, respectively. High concentrations of free D-amino acids were found in P. islandicum and H. salinarium; the concentrations of D-serine (12-13%), D-aspartate (4-7%) and D-proline (3-4%) were higher than those of D-alanine and D-glutamate. This result showed a resemblance between these archaea and not bacterial, but eukaryotic cells. The presence of D-amino acids was confirmed by their digestion with D-amino acid oxidase and D-aspartate oxidase. The occurrence of D-amino acids was also confirmed by the presence of activities catalyzing catabolism of D-amino acids in the P. islandicum homogenate, as measured by 2-oxo acid formation. The catalytic activities oxidizing D-alanine, D-aspartate and D-serine at 90 degrees C were considerably high. Under anaerobic conditions, dehydrogenase activities of the homogenate were 69, 84 and 30% of the above oxidase activities toward D-alanine, D-aspartate and D-serine, respectively. Comparable or higher dehydrogenase activities were also detected with these D-amino acids as substrate by the reduction of 2, 6-dichlorophenolindophenol. No D-amino acid oxidase activity was detected in the homogenates of M. barkeri and H. salinarium.

Amino Acids↗

PubMed1999

Topical application of neurotrophin-3 attenuates ischemic brain injury after transient middle cerebral artery occlusion in rats.

In order to examine the effect of neurotrophin-3 (NT-3) on ischemic brain injury, NT-3 was topically applied to brain surface just after 90 min of middle cerebral artery occlusion (MCAO) in rats. NT-3 significantly reduced the infarct size at 24 h of reperfusion. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick labeling (TUNEL) staining and immunohistochemical study for caspase-3 and heat shock protein 72 (HSP72) showed that NT-3 treatment decreased the number of cells with DNA fragmentation and caspase-3 and HSP72 expressions. These data suggest that NT-3 protects neuronal cells from ischemic injury, and it is possibly associated with inhibition of DNA fragmentation.

Administration, Topical↗

PubMed1999

Cytotoxic T cells against a peptide of Yo protein in patients with paraneoplastic cerebellar degeneration and anti-Yo antibody.

Anti-Yo antibodies are present in the sera and cerebrospinal fluid of some patients with paraneoplastic cerebellar degeneration (PCD), but there is no evidence that the presence of anti-Yo antibodies causes the Purkinje cell loss seen in PCD patients. We examined the level of cytotoxic T lymphocyte (CTL) activity against a nine-amino acid peptide of the Yo protein using the Human Leukocyte Antigen- (HLA-) based approach called reverse immunogenetics. Mononuclear cells (MNCs) were isolated from the peripheral venous blood and fibroblasts were obtained from the skin of three patients with PCD with anti-Yo antibody. After activating the MNCs of the three patients with the peptide, it showed CTL activity against the Yo protein peptide expressed on autologous fibroblasts. Therefore, CTLs may be involved in the loss of Purkinje cells in PCD.

Autoantibodies↗

PubMed1999

Cytosolic calcium changes in a process of platelet adhesion and cohesion on a von Willebrand factor-coated surface under flow conditions.

Recent flow studies indicated that platelets are transiently captured onto and then translocated along the surface through interaction of glycoprotein (GP) Ib with surface-immobilized von Willebrand factor (vWF). During translocation, platelets are assumed to be activated, thereafter becoming firmly adhered and cohered on the surface. In exploring the mechanisms by which platelets become activated during this process, we observed changes in platelet cytosolic calcium concentrations ([Ca(2+)]i) concomitantly with the real-time platelet adhesive and cohesive process on a vWF-coated surface under flow conditions. Reconstituted blood containing platelets loaded with the Ca(2+) indicators Fura Red and Calcium Green-1 was perfused over a vWF-coated glass surface in a flow chamber, and changes in [Ca(2+)]i were evaluated by fluorescence microscopy based on platelet color changes from red (low [Ca(2+)]i) to green (high [Ca(2+)]i) during the platelet adhesive and cohesive process. Under flow conditions with a shear rate of 1,500 s(-1), no change in [Ca(2+)]i was observed during translocation of platelets, but [Ca(2+)]i became elevated apparently after platelets firmly adhered to the surface. Platelets preincubated with anti-GP IIb-IIIa antibody c7E3 showed no firm adhesion and no [Ca(2+)]i elevation. The intracellular Ca(2+) chelator dimethyl BAPTA did not inhibit firm platelet adhesion but completely abolished platelet cohesion. Although both firm adhesion and cohesion of platelets have been thought to require activation of GP IIb-IIIa, our results indicate that [Ca(2+)]i elevation is a downstream phenomenon and not a prerequisite for firm platelet adhesion to a vWF-coated surface. After platelets firmly adhere to the surface, [Ca(2+)]i elevation might occur through the outside-in signaling from GP IIb-IIIa occupied by an adhesive ligand, thereby leading to platelet cohesion on the surface.

Blood Platelets↗

PubMed1999

Real-time analysis of mural thrombus formation in various platelet aggregation disorders: distinct shear-dependent roles of platelet receptors and adhesive proteins under flow.

We evaluated real-time processes of platelet thrombus formation on a collagen surface in a flow chamber with whole blood from patients with various platelet aggregation disorders, such as Bernard-Soulier syndrome (BSS), Glanzmann's thrombasthenia (GTA), type 3 von Willebrand disease (vWD), and congenital afibrinogenemia (Af), who lack platelet glycoprotein (GP) Ib-IX complex, GP IIb-IIIa, von Willebrand factor (vWF), and fibrinogen, respectively. Blood from GTA patients showed impaired thrombus growth but significant initial platelet-surface interaction under all shear conditions tested (50 to 1,500 s(-1)). By contrast, blood from patients with BSS or type 3 vWD showed no platelet-surface interaction under high shear (>/=1, 210 s(-1)) but normal thrombus formation under low shear (</=340 s(-1)). When shear rate was increased stepwise to 1,500 s(-1) during perfusion, the thrombus growth observed in type 3 vWD or BSS under low shear was arrested, whereas that in control blood was sharply accelerated as a function of shear rate. Overall thrombus formation in Af appeared indistinguishable from that of a control under shear rates between 50 and 1,500 s(-1). However, Af thrombi formed under such conditions collapsed immediately when shear rate was further increased to 4,500 s(-1), whereas thrombi of type 3 vWD or BSS formed under low shear were stable even when shear rate was elevated to 9,000 s(-1) during perfusion. These findings suggest that distinct molecular mechanisms underlie the pathologic bleeding in these diseases and point to the distinct roles of two major adhesive proteins, vWF and fibrinogen. In mural thrombus formation under flow conditions, vWF, perhaps mainly through its interaction with GP Ib-IX, acts as an "initiator and promoter," whereas fibrinogen, via its binding to GP IIb-IIIa, acts as a "stabilizer" against heightened shear forces that could lead to peeling off of platelets from the surface.

Blood Coagulation Disorders↗

PubMed1999

Mental stress test is an effective inducer of vasospastic angina pectoris: comparison with cold pressor, hyperventilation and master two-step exercise test.

BACKGROUND: Cold pressor, hyperventilation and exercise stress tests were usually used for inducing an angina attack in patients with vasospastic angina pectoris. We induced vasospastic angina attack using the mental calculation stress test, and compared the results with those using other stress tests. SUBJECTS AND METHODS: Subjects were 29 patients with vasospastic angina pectoris. Their ages were 60.8+/-8.4 years. Coronary vasospasm was induced by an acetylcholine infusion test during coronary angiography. The mental stress test was performed as follows; after memorizing six digits numbers, they repeated these numbers in reverse for 5 min, and performed serial subtraction of 17 from 1000 for 5 min. Blood pressure, heart rate and ECG were recorded every 1-5 min during the mental stress test. The serum concentrations of epinephrine and norepinephrine were measured before and during the mental stress test. We compared these results with those obtained using cold pressor, hyperventilation and the Master two-step exercise stress test. RESULTS: (1) Eight of the 29 patients (28%) showed ischemic ST-T change, which was caused by the mental stress test. (2) The increase in norepinephrine was greater in patients with an ST-T change than without an ST-T change (0.11+/-0.06 vs. 0.04+/-0.04 ng/ml, P<0.01). (3) The incidence of the ST-T change caused by the mental stress test (28%) was similar to the cold pressor test (27%) and greater than that caused by the hyperventilation test (13%). The incidence of ST-T change caused by the Master two-step test was 55%. CONCLUSIONS: The mental stress test is an effective inducer of vasospastic angina attack, and attack may be induced by neurohumoral vasoconstrictive reflex and/or increased left ventricular afterload.

Acetylcholine↗

PubMed1999

No mutation in the entire coding region of the alpha-synuclein gene in pathologically confirmed cases of multiple system atrophy.

To determine whether mutations in the coding region of the alpha-synuclein gene are relevant in cases of multiple system atrophy (MSA), detailed nucleotide sequence analysis of the alpha-synuclein gene was performed using total RNA obtained from autopsied brain specimens of 11 pathologically confirmed cases of MSA. The brain specimens used in this study contained both gray and white matter, which were dissected from the frontal, temporal or occipital lobe. No nucleotide alterations were found in the entire coding region of the alpha-synuclein gene in any of the cases. While mutations in the regulatory or intronic regions of the gene were not ruled out, our results suggest that mutations in the coding region of the alpha-synuclein gene are unlikely to contribute to the pathogenesis of MSA.

Aged↗

PubMed1999

Quantitative analysis of expression of mouse sialyltransferase genes by competitive PCR.

The present paper describes a rapid and systematic method for semi-quantitative analysis of the expression of sialyltransferase genes. So far, fifteen sialyltransferase cDNAs have been cloned from mice. Most of these genes are expressed in developmental stage-dependent and/or tissue-specific manners, and the expression levels of some of them are too low to detect on Northern blot analysis. To resolve how each sialyltransferase contribute to synthesize sialylglycoconjugates, it is necessary to establish the method for quantification of gene expression levels of these fifteen sialyltransferases. Therefore, we developed a competitive PCR-based method for analyzing the quantitative relationship of the gene expression of fifteen sialyltransferases. Using this method, we can investigate the levels of gene expression of sialyltransferases in various cell lines and various tissues of mice, and can accurately determine their expression levels.

Animals↗

PubMed1999

Restricted occurrence of Lewy bodies in the dorsal vagal nucleus in a patient with late-onset parkinsonism.

Lewy body (LB) is consistently found in the substantia nigra in Parkinson's disease. We report a 68-year-old woman with late-onset, dopa-responsive parkinsonism. Her parents were first cousins, but no other affected individuals were present in the family. Autopsy revealed moderate loss of pigmented neurons with gliosis, but neither LBs nor neurofibrillary tangles in the substantia nigra. The locus ceruleus showed neuronal loss with scarce LBs. The most striking change was found in the dorsal vagal nucleus, where marked neuronal loss and fibrillary gliosis with many LBs were evident. Despite the use of ubiquitin and alpha-synuclein immunohistochemistry, no further LBs were identified in other brain regions. These findings suggest that this case was an unusual, anatomically restricted manifestation of LB disease.

Antiparkinson Agents↗

PubMed1999

Regulation of transcription factor C/ATF by the cAMP signal activation in hippocampal neurons, and molecular interaction of C/ATF with signal integrator CBP/p300.

The CCAAT/enhancer binding proteins related activating transcription factor, C/ATF, is a mouse leucine-zipper transcription factor which is structurally homologous to ApCREB2, a suppressor integral to long-term synaptic plasticity in Aplysia. To gain a clue to whether C/ATF is involved in long-term plasticities of brain, we examined if the expression levels of C/ATF are modulated by cAMP, an inducer crucial for memory formation in Aplysia, Drosophila and mice. Our in situ hybridization analysis revealed the expression of C/ATF mRNA in hippocampal neurons. C/ATF protein levels increased after the cAMP signal stimulation in hippocampal neurons, while C/ATF mRNA levels remained constant. The human activating transcription factor 4 (hATF4), another homolog of ApCREB2, interacts with multiple domains of the coactivator CREB-binding protein (CBP), resulting in the potentiation of its ability to activate transcription. As expected, C/ATF was found to interact with three domains of CBP including CREB binding domain or kinase-inducible interaction (KIX) domain, the third cysteine-histidine-rich region (CH3 domain) and the nuclear receptor coactivator p160/SRC-1-interacting domain. Interestingly, C/ATF was further found to interact strongly with CREB binding protein/p300 (CBP/p300) CH1 domain. Mammalian two hybrid assays indicated that the interaction between C/ATF and CBP/p300 can occur in mammalian cells, and that the p300 CH1 domain is critical for the interaction. Thus, C/ATF may be implicated in transcription-dependent phase of hippocampal long-term plasticities through the modulation of its protein level under cAMP signal and the interaction with signal integrator, CBP/p300.

Activating Transcription Factor 4↗

PubMed1999

Administration of prosaposin ameliorates spatial learning disturbance and reduces cavity formation following stab wounds in rat brain.

The effectiveness of prosaposin as a neurotrophic factor was investigated using rats with bilateral stab wounds, injecting 240 ng per day of prosaposin for 3 days. In Morris water maze task, after 3 weeks postoperation, the stab-wounds rats show significant impairment in acquisition compared with the sham-operated rats. In the transfer test the mean number of crossings of the platform place in stab-wounds was significantly lower than that in sham-operated rats (P < 0.01). The stab-wounds rats treated with prosaposin showed significant improvement (P < 0.05). The cavities following stab wounds in the rats treated with prosaposin were significantly smaller than those in the rats treated with (P < 0.05). Our data support that prosaposin is likely to be a new agent for brain injury.

Animals↗

PubMed1999

Induction of cell-cycle arrest and apoptosis by a novel retinobenzoic-acid derivative, TAC-101, in human pancreatic-cancer cells.

In this study, we investigated the effect of a novel retinobenzoic acid, 4-[3,5-bis (trimethylsilyl) benzamido] benzoic acid (TAC-101), on the growth of 4 human pancreatic-cancer cell lines; BxPC-3, MIAPaCa-2, CFPAC-1 and AsPC-1. TAC-101 significantly inhibited the proliferation of BxPC-3 and MIAPaCa-2 cells in a time- and concentration-dependent manner, but not the proliferation of AsPC-1 cells. Furthermore, the anti-proliferative effects of TAC-101 on BxPC-3 and MIAPaCa-2 cells were stronger than those of all-trans retinoic acid. Flow-cytometric analyses indicated that treatment of BxPC-3 with TAC-101 strongly induces cell-cycle arrest at the G1 phase. The cell-cycle arrest induced by TAC-101 was accompanied by reduction of retinoblastoma-gene product (RB) phosphorylation and an increase of 2 cyclin-dependent kinase (CDK) inhibitors, p21(WAF1/Cip1) (p21) and p27Kip1 (p27). TAC-101 also caused a decrease in cyclin A and thymidylate synthase, which are E2F-regulated gene products. No changes were observed in the expression of cyclin D1, cyclin E on CDK2. In addition, Hoechst staining, gel electrophoresis and flow-cytometric analysis indicated that a marked reduction in the number of BxPC-3 cells with TAC-101 was related to the induction of apoptosis. Our results suggest that TAC-101 inhibits the growth of certain pancreatic-cancer cells by means of G1-phase cell-cycle arrest resulting from the reduction of RB phosphorylation and the up-regulation of p21 and p27 as well as the induction of apoptosis. TAC-101 may therefore be a useful agent for new therapeutic strategies focusing on inhibition of pancreatic-cancer-cell proliferation.

Antineoplastic Agents↗

PubMed1999

Molecular cloning and functional expression of two members of mouse NeuAcalpha2,3Galbeta1,3GalNAc GalNAcalpha2,6-sialyltransferase family, ST6GalNAc III and IV.

Two cDNA clones encoding NeuAcalpha2,3Galbeta1,3GalNAc GalNAcalpha2, 6-sialyltransferase have been isolated from mouse brain cDNA libraries. One of the cDNA clones is a homologue of previously reported rat ST6GalNAc III according to the amino acid sequence identity (94.4%) and the substrate specificity of the expressed recombinant enzyme, while the other cDNA clone includes an open reading frame coding for 302 amino acids. The deduced amino acid sequence is not identical to those of other cloned mouse sialyltransferases, although it shows the highest sequence similarity with mouse ST6GalNAc III (43.0%). The expressed soluble recombinant enzyme exhibited activity toward NeuAcalpha2, 3Galbeta1, 3GalNAc, fetuin, and GM1b, while no significant activity was detected toward Galbeta1,3GalNAc or asialofetuin, or the other glycoprotein substrates tested. The sialidase sensitivity of the 14C-sialylated residue of fetuin, which was sialylated by this enzyme with CMP-[14C]NeuAc, was the same as that of ST6GalNAc III. These results indicate that the expressed enzyme is a new type of GalNAcalpha2,6-sialyltransferase, which requires sialic acid residues linked to Galbeta1,3GalNAc residues for its activity; therefore, we designated it mouse ST6GalNAc IV. Although the substrate specificity of this enzyme is similar to that of ST6GalNAc III, ST6GalNAc IV prefers O-glycans to glycolipids. Glycolipids, however, are better substrates for ST6GalNAc III.

Amino Acid Sequence↗