Biomedical subjects

E Yoshida

Publications and source records attributed to E Yoshida.

At least 37 records · Page 2Linked to original sources

PubMed1999

Immunohistochemical demonstration of inter-alpha-trypsin inhibitor light chain (bikunin) in human mast cells.

We recently reported that the rat mast cell proteinase inhibitor trypstatin is genetically identical with the second half of inter-alpha-trypsin inhibitor light chain (ITI-LC), also known as bikunin or urinary trypsin inhibitor (UTI). In this study, therefore, immunoreactivities of mast cells of various human tissues were examined with three antibodies, anti-human ITI-LC, anti-ITI, which recognizes mainly heavy chains or the sugar moiety of ITI, and anti-alpha 1-microglobulin (alpha1mG). ITI-LC immunoreactivity was strongly found in mast cells in the connective tissues of various organs except for those of the propria mucosae of small intestine. Neither anti-ITI antibody nor anti-alpha1mG antibody reacted with mast cells in various tissues. By reverse transcription-polymerase chain reaction (RT-PCR) analysis, alpha1mG/ITI-LC mRNA was not detected in the skin and tongue, and only weakly in small intestine, although ITI-LC immunoreactivity was strongly detected in these tissues. Furthermore, the mRNA was not expressed in cultured human mast cells. These results suggest that ITI-LC protein is stored in the granules of human connective tissue mast cells, though is not produced by them.

Alpha-Globulins↗

PubMed1999

Epitopes and nuclear localization analyses of canine distemper virus nucleocapsid protein by expression of its deletion mutants.

A series of nucleocapsid protein (NP)-deleted genes of the Onderstepoort strain was constructed in order to locate antigenic regions of the NP of canine distemper virus. The expression of proteins from 5'-deleted NP genes was examined in COS-7 cells by indirect immunofluorescence assay using three monoclonal antibodies (MAbs), c-5, f-5 and h-6, and a rabbit serum against NP. These MAbs reacted with two regions of NP. Amino acid residues from 1 to 80, and 337-358, were necessary and sufficient for formation of the epitopes identified by MAbs f-5 and h-6, and c-5, respectively. The proteins translated from intact or 3'-deleted genes were found to be localized in the nuclei of COS-7 cells, whereas the proteins from the 5'-deleted genes were mainly detected in the cytoplasm. These results suggested that 80 amino acid residues at the N-terminus are required for transportation of NP into the nucleus.

Animals↗

PubMed1999

Simultaneous up-regulation of urokinase-type plasminogen activator (uPA) and uPA receptor by hepatocyte growth factor/scatter factor in human glioma cells.

Several lines of evidence indicate that hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, c-Met, may play an important role in progression of human glioma. In this study, effects of HGF/SF on urokinase- type plasminogen activator (uPA)-mediated proteolysis network were examined in c-Met-positive human glioma cell lines. Treatment of the glioma cells with various concentrations of HGF/SF resulted in an enhanced secretion of uPA proteins accompanying increased transcription of uPA mRNA in a dose dependent fashion. The levels of uPA receptor (uPAR) mRNAs were also elevated simultaneously upon HGF/SF stimulation, and the cell-surface associated uPA activity was also elevated by the treatment. Since concomitant expression of HGF and its receptor c-Met are frequently observed in malignant gliomas, these results suggest that HGF/SF participates in invasive process of malignant glioma cells not only by its motility-stimulating activity but also through enhanced degradation of the extracellular matrix induced by autocrine activation of uPA proteolysis network.

Central Nervous System Neoplasms↗

PubMed1999

[Clinicopathological characteristics of Creutzfeldt-Jakob disease with a PrP V180I mutation and M129V polymorphism on different alleles].

We report an 80-year-old Japanese man with histologically-diagnosed Creutzfeldt-Jakob disease (CJD). The patient was admitted to our neurological unit because of sudden onset motor aphasia-like symptoms and right hemiparesis. His medical and family histories were unremarkable, and he had taken no medications. Urine, blood counts and blood chemistry were all within normal limits. Cerebrospinal fluid was normal except for elevation of neuron specific enolase (29.9 ng/ml). High-signal intensity was demonstrated in the cortex of the left temporal lobe on T2-weighted MRI images, and the lesion swelled during the initial stage of the disease. There was no enhancement with Gd-DTPA. Serial MRI showed that the high-signal lesion had spread into the bilateral cerebral cortex. The patient developed myoclonus followed by akinetic mutism within 6 months of onset. Consecutive EEGs revealed no periodic synchronous discharge (PSD). He died of pneumonia 21 months after of admission. Autopsy revealed spongiform changes in the cerebral cortex with Kuru plaques, confirming the diagnosis of CJD. The Cerebellar cortex was well preserved. The high-signal lesions corresponded to the spongiform changes in the cerebral cortex. Immunohistochemical analysis showed weak synaptic prion staining. Prion protein (PrP) gene analysis of genomic DNA isolated from the autopsied brain by polymerase chain reaction, the restriction fragment length polymorphisms, and direct sequencing revealed a point mutation (Val-->Ile) at codon 180 and a polymorphism (Met/Val) at codon 129 on different alleles. A few CJD patients with point mutations in codon 180 of the PrP gene have been reported. Combination of the codon 180 point mutation and codon 129 polymorphism may yield an atypical clinicopathological form of CJD that includes late onset, negative PSD, and atypical MRI findings, with preservation of the cerebellar cortex.

Aged↗

PubMed1999

[Therapeutic case of general paresis manifested by bradykinesia and recent memory loss].

We reported a 32-year-old man with general paresis. He showed slowly progressive bradykinesia and recent memory loss. Argyll Robertson pupils were not present. Muscle strength and sensations were normal except for slight vibratory disturbance. Tendon reflexes were slightly exaggerated. MMSE, HDS-R and WAIS-R scores showed the intellectual impairment. His laboratory investigations revealed elevated both TPHA and FTA-ABS titers in the serum and the CSF. The CSF contained leukocytosis (25/mm3) and protein 80 mg/dl. Cranial CT and MRI demonstrated diffuse cortical atrophy. SPECT revealed marked reduction of the blood flow in bilateral cerebral hemisphere. Cerebral angiography revealed moderate stenosis of the major vessels. The diagnosis of neurosyphilis (general paresis) was made and the treatment of intravenous benzyl penicillin potassium 24 million units per day was started. After 6 weeks of the treatment, the clinical signs (includes MMSE, HDS-R and WAIS-R scores) and the findings of SPECT and cerebral angiography showed improvement. Although the cell count and protein in the CSF became decreased, the titers of TPHA and FTA-ABS in the serum and the CSF were not decreased. Neurosyphilis should always be considered in a etiologically unknown case with bradykinesia and dementia.

Adult↗

PubMed1998

Prostaglandin I2 analog enhances the expression of urokinase-type plasminogen activator and wound healing in cultured human fibroblast.

This study examines the effects of prostaglandin I2 (PGI2) on urokinase-type plasminogen activator (uPA) production and wound healing by human fibroblasts. Employing fibrin autography, it was found that beraprost sodium, a stable PGI2 analog, enhanced the fibrinolytic activity in media conditioned by human fibroblasts, TIG-3-20 cells. Fibrin zymography, ELISA, and Northern blot analysis confirmed that the enhanced activity was caused by an increase in uPA synthesis and secretion and a decrease in type-1 plasminogen activator inhibitor. While cycloheximide and 2',5'-dideoxyadenosine, an adenylate cyclase inhibitor, suppressed the effect of PGI2, dibutyryl cyclic AMP increased the fibrinolytic activity and uPA mRNA. These findings indicate that PGI2 promotes uPA production in TIG-3-20 cells via direct stimulation of the cyclic AMP intracellular pathway. A similar effect was observed in two other fibroblast cell lines, TIG-7-20 and TIG-7-30. Although PGI2 itself did not affect cellular proliferation, it promoted in vitro repopulation of the denuded area in a wounded monolayer. These observations suggest that PGI2 can stimulate wound healing through the enhanced production of uPA.

Cell Movement↗

PubMed1998

Identification of N-terminal minimal transactivation domain of CBP, p300 and caenorhabditis elegans homologues.

CBP/p300 is a multidomain transcriptional cofactor that acts in junction with other factors to regulate transcription. To elucidate the domain function of CBP, we fused its dissected fragments to Ga14 DNA-binding domain and transfected the deletion mutants into several cell lines. First, we found that the minimal transactivation domain (MTD) at the N-terminal portion maps to between 344 and 451 aa, and shows activity in a cell-type dependent manner. Second, we cloned C. elegans homologues corresponding to the MTD by RT-PCR and identified the three related products, two of which exhibited weak transcriptional activity. Finally, by means of the yeast two hybrid screening using MTD as a bait, we cloned hypoxia-inducible factor (HIF) 1 alpha and Stat2 cDNAs. These results suggested a functional role of MTD located at the N-terminal region of CBP/p300 in connecting to transcriptional factors.

Alternative Splicing↗

PubMed1998

Molecular analysis of the nucleocapsid protein of recent isolates of canine distemper virus in Japan.

We analyzed the molecular properties of the nucleocapsid protein (NP) of canine distemper viruses (CDV), isolated between 1992 and 1995 in Japan. Four CDV field isolates (Yanaka, Ueno, Hamamatsu, and Adachi strains) obtained were antigenically identical. Sequence analysis of entire region of the NP gene of a field isolate, the Yanaka strain, revealed that the NP gene contained 1683 nucleotides and was 93.2% homologous with a laboratory strain, the Onderstepoort strain. The deduced amino acid sequence contained 523 amino acids and was 95.2 and 99% homologous with those of the Onderstepoort and a virulent strain, A75/17 strain, respectively. Since most of the diversities in amino acid sequence occurred in two domains, at the N'- and the C'- termini, we further sequenced 3'-terminal regions of the remaining three field isolates. Based on the sequences, the new CDV isolates had one cluster that distinguished them from the laboratory strain.

Amino Acid Sequence↗

PubMed1998

Activation of single-chain urokinase-type plasminogen activator by a hemorrhagic metalloproteinase, jararafibrase I, in Bothrops jararaca venom.

Urokinase-type plasminogen activator (uPA) activates plasminogen to plasmin, which is involved in the degradation of the vascular basement membrane and extracellular matrix. The present study was undertaken to examine the effects of several hemorrhagic metalloproteinases, jararafibrase (JF) I, II, III and IV, purified from Bothrops jararaca venom, on the single-chain zymogen form of uPA (scuPA). Activation of scuPA by JF I IV was estimated using a synthetic substrate for uPA (S-2444). Only JF I activated the scuPA in a time- and dose-dependent manner. SDS-PAGE analysis revealed that, after incubation with JF I, the intensity of the 55 kDa band of scuPA decreased concomitantly with increases in the intensity of the major two bands at 32 and 22 kDa under reduced and non-reduced conditions. The 32 kDa band demonstrated fibrinolytic activity in fibrin-zymographic studies. Amino-acid-sequence analysis revealed that JF I cleaved the position of 143Glu-144Leu in scuPA, indicating that JF I formed low molecular weight scuPA. From these results, it seems possible that activation of scuPA by JF I could be responsible in part for the local hemorrhage and tissue damage that are frequently observed in human victims of B. jararaca envenoming.

Crotalid Venoms↗

PubMed1998

Inhibition of a snake venom hemorrhagic metalloproteinase by human and rat alpha-macroglobulins.

Jararafibrase I is a hemorrhagic metalloproteinase purified from Bothrops jararaca venom, which induces local hemorrhage by degrading the basement membrane components. The present study was undertaken to investigate the inhibition of jararafibrase I by human and rat serum proteinase inhibitors. The proteolytic activity of jararafibrase I was completely inhibited by human and rat sera. In particular, rat serum displayed a greater inhibitory capacity. The inhibitory capacities of both sera were dependent on alpha-macroglobulins. SDS-PAGE analysis revealed that jararafibrase I formed complexes with alpha-macroglobulins that were present in normal sera. The proteolytic activity of jararafibrase I was completely inhibited by alpha1-macroglobulin and murinoglobulin in rat serum, and by human alpha2-macroglobulin. The inhibition molar ratios of alpha-macroglobulin/jararafibrase I were 1.5 for rat alpha1-macroglobulin and human alpha2-macroglobulin, and 2.4 for rat murinoglobulin. SDS-PAGE under reducing conditions demonstrated that the bait region of human alpha2-macroglobulin and rat murinoglobulin was cleaved by jararafibrase I. The bait region cleavage sites were identified as being situated at the 696Arg-697Leu peptide bond in human alpha2-macroglobulin, and at the 686Ala-687Val peptide bond in rat murinoglobulin.

Amino Acid Sequence↗

PubMed1998

Isolation and characterization of 5'-regulatory region of mouse activin beta A subunit gene.

We isolated genomic clones that contain the 5'-flanking region of the mouse activin beta A subunit gene. The nucleotide sequence determination of the 5'-flanking region of the gene and the comparison of that with the reported mouse cDNA structure identified the putative 5' regulatory region, a novel first exon and a part of the first intron of the gene within this region. The putative 5' regulatory region of the mouse activin beta A subunit gene directed the expression of CAT gene in transfected HT1080 cells. Successive deletions of this region demonstrated a 400-bp region that exerts a strong positive effect on promoter activity of the mouse activin beta A subunit gene.

Animals↗

PubMed1998

The nucleotide and predicted amino acid sequence of the fusion protein of recent isolates of canine distemper virus in Japan.

Analysis of the molecular properties of fusion (F) proteins of field isolates of canine distemper virus (CDV) by immunoprecipitation analysis revealed an identical molecular mass of F protein of 3 field isolates as well as the Onderstepoort laboratory strain. Sequencing showed that the F gene of a field isolate (the Yanaka strain) shared 90.1% and 95.7% identities with the Onderstepoort strain at nucleotide and amino acid levels, respectively. All of the 13 cysteine residues and 4 potential asparagine-linked glycosylation sites were completely conserved amongst these strains. These results indicate that the F proteins is much less heterogeneous than that observed in the hemagglutinin proteins of CDV.

Amino Acid Sequence↗

PubMed1998

[Sex and age distribution of patients with macroamylasemia found in the daily isoenzyme analysis].

We studied distributions of sex and age for 102 patients with macroamylasemia found in routine isoenzyme analysis. This study was based on a questionnaire to promote understanding of the clinical significance of macroamylase. More than half of the physicians received our report evaluated the information on macroamylase in the questionnaire. Macroamylasemia found in this study consisted of IgA type immunoglobulin in 92% and mostly had high activities in the serum. The back-ground of these patients with macroamylasemia were 10 cases of hepato-biliary disease, 9 cases of diabetes mellitus, 8 cases of autoimmune disease and so on. The frequency of macroamylasemia in males was double than in females and age distribution was not significant in statistic analysis.

Adolescent↗

PubMed1997

Functional association between CBP and HNF4 in trans-activation.

CBP functions as a key transcriptional coactivator for a variety of transcription factors. We show here that the hepatocyte nuclear factor 4 (HNF4), a transcription factor in the nuclear receptor superfamily with no defined ligand, is cloned by yeast two-hybrid system using CBP as a bait. GST-pull down assay with nuclear extracts or in vitro translation products revealed that CBP and HNF4 interact with each other at the middle portion (aa 119-375) of HNF4 and two distinct regions (aa 271-451 and 1626-2259) of CBP, respectively, in the ligand-independent manner. Co-transfection experiments indicated that CBP is capable of activating HNF4 site-mediated transcription. These results suggested a functional association between CBP and HNF4 in trans-activation.

Animals↗

PubMed1997

Effects of exogenous p16INK4a on growth of cells with various status of cell-cycle regulators.

p16INK4a, a protein that inhibits cyclin-dependent kinase 4 (Cdk4) and Cdk6, is deficient in many human cancers and in established lines of tumor cells. It has been reported that transfection with cDNA for p16INK4a inhibits the growth of cell lines that express retinoblastoma protein (pRB). However, it is unclear whether the introduction of cDNA for p16INK4a affects the growth of cells that express p16INK4a protein. Moreover, the effects of other cell-cycle regulators on the inhibition of cell growth by p16INK4a remain unknown. In this study, cDNA for p16INK4a was used to transfect human cell lines that had various status of expression of RB pathway-related proteins, such as members of the RB family proteins and Cdk-inhibitory proteins. We found that status of p107, p130, p15INK4b, p18INK4c, p21Cip1, p27Kip1, cyclin D1, and Cdk4 were not correlated with the growth-inhibitory activity of exogenous p16INK4a. By contrast, transfection with cDNA for p16INK4a had a significant effect on the growth of cells depended on the status not only of pRB but also of p16INK4a. Although exogenous p16INK4a inhibited the growth of cells that expressed pRB but did not express p16INK4a (pRB+/p16- cells), it had little affect on either pRB+/p16+ cells or pRB-/p16+ cells. Moreover, transfection with cDNA for p16INK4a also inhibited the activity of the E2 promoter of the dehydrofolate reductase gene in the same manner that depended on the absence of p16INK4a, as well as on the presence of pRB. These results suggest that deregulation of the RB pathway by p16INK4a deficiency plays a very important role in the proliferation of cells that lack p16INK4a protein.

Base Sequence↗

PubMed1997

Down regulation of epidermal growth factor receptors in rat hepatocytes treated with clofibric acid.

The effect of clofibric acid (CA), a peroxisome proliferator and a non-genotoxic hepatocarcinogen was investigated on epidermal growth factor (EGF) receptors in hepatocytes of female Sprague-Dawley rats treated at a dose of 9000 ppm in a diet for up to 13 weeks. Hepatocyte plasma membranes were isolated in Weeks 1 and 13, and assayed with [125I]EGF. The binding of EGF to the hepatocyte plasma membranes was reduced in Week 1 as a result of decreased number of low-affinity receptors. The fall of binding capacity was further evident in Week 13, which was associated with decreased numbers of both high- and low-affinity receptors. The equilibrium dissociation constant remained unchanged either in Week 1 or 13. These results were in agreement with previous observations of a decreased hepatocyte response to mitogens after prolonged treatment with CA. This suggested that the CA-associated liver tumor promoting effect is related to its ability to decrease the number of EGF receptors and the resultant aberrant growth environment.

Administration, Oral↗

PubMed1997

Expression of p16INK4a suppresses the unbounded and anchorage-independent growth of a glioblastoma cell line that lacks p16INK4a.

p16INK4a is a inhibitory protein of Cyclin-dependent kinase 4(Cdk4).p16 negatively regulates the cell cycle progression from G1 to S phase. Functional p16 is absent from many human cancers, as well as from many established lines of tumor cells. However, it is not clear whether expression of p16 in p16-deficient tumor cells can suppress their anchorage-independent growth. Therefore, we introduced a cDNA for p16INK4a into the human glioblastoma cell line T98G, which lacks a gene for p16INK4a. We isolated several clones that stably expressed various amounts of p16 protein. The doubling time of the various clones was generally prolonged. Clones with high-level expression of p16 protein had characteristics of restricted growth, such as contact inhibition, while the parental T98G cells had no such characteristics. Furthermore, the efficiency of colony formation in soft agar was dramatically decreased in the case of cells that expressed exogenous p16. Our observations suggest that the expression of p16 protein restricts the unbounded growth and the anchorage-independent growth of tumor cells.

Carrier Proteins↗

PubMed1997

Molecular and phylogenetic analyses of the haemagglutinin (H) proteins of field isolates of canine distemper virus from naturally infected dogs.

We isolated three strains of canine distemper virus (CDV)--the Ueno, Hamamatsu, and Yanaka strains--from dogs in Japan and analysed the molecular properties of their haemagglutinin (H) proteins. Immunoprecipitation of all three strains with a monoclonal antibody revealed H proteins with molecular masses of 84 kDa, which differs from the molecular mass (78 kDa) of the H protein of the Onderstepoort vaccine strain. However, after tunicamycin treatment immunoprecipitation identified H proteins of identical molecular mass (68 kDa) for all three field isolates and the vaccine strain. Sequence analysis showed nine potential sites for asparagine-linked glycosylation in the H proteins of the new isolates, in contrast to four in the H protein of the Onderstepoort strain. Thus, variation in glycosylation of the H proteins of the isolates and the vaccine strain may cause differences in antigenicity of the viruses. Sequences of the H genes showed that the new Japanese isolates have 99% identity with each other, 95% with other European and American isolates (from seals, a German dog, a ferret and large felids) and 90% with the vaccine strain. Phylogenetically, the new Japanese isolates form one cluster which is separate from recent European or American isolates, all of which are distinct from vaccine strains.

Amino Acid Sequence↗