Biomedical subjects

T Miyazawa

Publications and source records attributed to T Miyazawa.

At least 127 records · Page 7Linked to original sources

PubMed1999

Isolation of feline parvovirus from peripheral blood mononuclear cells of cats in northern Vietnam.

Feline parvovirus (FPV) was isolated rather frequently from the peripheral blood mononuclear cells (PBMCs) of cats in northern Vietnam by coculturing with MYA-1 cells (an interleukin-2-dependent feline T lymphoblastoid cell line) or Crandell feline kidney (CRFK) cells (a feline renal cell line). Efficiency of virus isolation was higher in MYA-1 cells than in CRFK cells. Interestingly, among the 17 cats from which FPV was isolated, 9 cats were positive for virus neutralizing (VN) antibody against FPV, indicating that FPV infected PBMCs and was not eliminated from PBMCs even in the presence of VN antibodies in the cats.

Animals↗

PubMed1999

Development of restriction fragment-length polymorphism method to differentiate five subtypes of feline immunodeficiency virus.

Feline immunodeficiency virus (FIV) isolates have been classified into five subtypes (A to E) based on the sequences of the env variable V3 to V5 region. In this study, we sequenced a partial gag region of 4 and 3 isolates belonging to subtypes C and E, respectively. Phylogenetic analysis revealed that the branching pattern based on the region was similar to that based on the env V3 to V5 region. Here, we propose a protocol to differentiate five subtypes by polymerase chain reaction amplifying 329 bp within the region followed by restriction fragment-length polymorphism analysis using four restriction enzymes.

Animals↗

PubMed1999

Effects of tirilazad mesylate on vasospasm and phospholipid hydroperoxides in a primate model of subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Tirilazad mesylate has been used in the attempt to prevent cerebral vasospasm after subarachnoid hemorrhage (SAH), although the actual targets of this agent in vivo have thus far been controversial. Chemiluminescence/high-performance liquid chromatography provided a new method for direct measurements of phosphatidylcholine hydroperoxide (PCOOH) and phosphatidylethanolamine hydroperoxide (PEOOH) in vivo and showed that phosphatidylcholine is the lipid class most susceptible to lipid peroxidation. In the present study we measured those levels in a primate model of SAH for determination of the effects of tirilazad on vasospasm. METHODS: Fourteen Macaca monkeys of both sexes were randomly assigned into 2 groups: a tirilazad group receiving a dosage of 0.3 mg/kg and a placebo group receiving only the vehicle in which tirilazad was delivered. After the induction of experimental SAH around the right middle cerebral artery on day 0, tirilazad or vehicle was administered intravenously every 8 hours for 6 days. On day 7, the animals were killed after angiography and regional cerebral blood flow measurements were performed. The levels of PCOOH and PEOOH were measured in the clots, bilateral parietal cortices, right frontal cortex contact with clots, cerebellar hemispheres, bilateral middle cerebral arteries, and basilar arteries. RESULTS: In the placebo group, a significant vasospasm occurred in the cerebral arteries on both sides, but most prominently on the right side. The degree of vasospasm in the cerebral arteries was significantly attenuated in the tirilazad group (P<0.005). There were no significant differences in regional cerebral blood flow, PCOOH, and PEOOH levels in the clots, cerebral cortices, and cerebellar hemispheres between the 2 groups. In contrast, the levels of PCOOH in the cerebral arteries were significantly higher in the placebo group than in the tirilazad group (P<0.025). It was remarkable that the tirilazad treatments eliminated PCOOH in any vascular territory after SAH. CONCLUSIONS: PCOOH in the artery wall may be an important indicator for vasospasm, and the inhibition of PCOOH may explain the efficacy of tirilazad on vasospasm.

Animals↗

PubMed1999

Antioxidative effects of turmeric, rosemary and capsicum extracts on membrane phospholipid peroxidation and liver lipid metabolism in mice.

Phospholipid hydroperoxides (PLOOH) in the plasma, red blood cells (RBC) and liver of mice were measured after dietary supplementation for one week (1% w/w of diet) with a turmeric extract (curcuminoid), hexane extract of rosemary, and supercritical CO2-extracted capsicum pigment (supplemented with alpha-tocopherol to prevent fading). A lower PLOOH level was found in RBC of the spice extract-fed mice (65-74% of the non-supplemented control mice). The liver lipid peroxidizability induced with Fe2+/ascorbic acid was effectively suppressed by dietary supplementation with the turmeric and capsicum extracts to mice. While no difference in the plasma lipids was observed, the liver triacylglycerol concentration of the turmeric extract-fed mice was markedly reduced to one-half of the level in the control mice. These findings suggest that these spice extracts could act antioxidatively in vivo by food supplementation, and that the turmeric extract has the ability to prevent the deposition of triacylglycerols in the liver.

Animals↗

PubMed1999

Identification of the Marek's disease virus serotype 2 genes homologous to the glycoprotein B (UL27), ICP18.5 (UL28) and major DNA-binding protein (UL29) genes of herpes simplex virus type 1.

We determined the nucleotide sequence of non-pathogenic Marek's disease virus serotype 2 (MDV2) strain HPRS24 glycoprotein B (gB) (UL27), ICP18.5 (UL28) and major DNA-binding protein (MDBP) (UL29) genes homologous to herpes simplex virus type 1 (HSV-1). The sequence data revealed that important motives in the proteins are conserved in MDV2 ICP18.5 and MDBP, however the sequence of viral DNA replication origin which exists in the regions between the UL29 and UL30 genes of other alphaherpesviruses was not found in the regions of the MDV2 genome. By northern blot analyses, we also demonstrated that 8.9, 5.0 and 2.6 kb transcripts were actually transcribed from the sequenced region in MDV2-infected cells. The MDV2 UL28 and UL29 genes have not been reported in other serotypes of MDV.

Amino Acid Sequence↗

PubMed1999

Comparison of prevalence of feline herpesvirus type 1, calicivirus and parvovirus infections in domestic and leopard cats in Vietnam.

A serosurvey of feline herpesvirus type 1 (FHV-1), feline calicivirus (FCV), and feline parvovirus (FPV) in cats from Ho Chi Minh City area in southern Vietnam was conducted in December 1998, and we compared the results with our previous results in northern Vietnam (Hanoi area). The positive rate of FHV and FCV in domestic cats were 44% and 74%, respectively. They were rather higher than those in Hanoi area, while the seropositivity of FPV (44%) was similar to that in Hanoi area. In leopard cats, the positive rate of FPV was high (3/4) and it indicated that FPV was prevailing in leopard cats in Vietnam.

Animals↗

PubMed1999

Feline immunodeficiency virus subtype C is prevalent in northern part of Taiwan.

The seroepidemiological survey of cats conducted in northern part of Taiwan in 1998 revealed that the positive rate of feline immunodeficiency virus (FIV)-infection was 21.9% (7/32) and the rate was much higher than those of previous reports. We succeeded in isolation of three strains of FIV from peripheral blood mononuclear cells of the blood samples. Nucleotide sequences of the env variable V3 to V5 region of the strains revealed that the isolates from distinct areas belong to subtype C. These data together with our previous report (Inada et al. 1997. Arch. Virol., 142: 1459-1467) indicate that FIV subtype C is prevalent in northern part of Taiwan.

Amino Acid Sequence↗

PubMed1999

Identification and structure of the Marek's disease virus serotype 2 glycoprotein M gene: comparison with glycoprotein M genes of Herpesviridae family.

We determined the nucleotide sequence of a portion of BamHI-C fragment of Marek's disease virus serotype 2 (MDV2) strain HPRS24 which was suspected to contain the homologue of the herpes simplex virus type 1 (HSV-1) gene UL10, encoding glycoprotein M (gM). An open reading frame whose translation product exhibited significant similarities to HSV-1 gM protein and respective proteins of other herpesviruses of 37.5% and 45.5% to 31.8%, respectively, was identified. A number of distinct transcriptional consensus sequences were found upstream of the first putative start codon of MDV2 UL10 protein. In transcriptional analysis, the gene was transcribed into an 1.5 kb RNA. The primary translation product comprises 424 amino acids with a predicted molecular weight of 46.9 kDa. The predicted MDV2 UL10 protein contains eight hydrophobic domains with sufficient length and hydrophobicity to span the lipid bilayer conserved in the genomes of all herpesviruses which have been sequenced so far. In the region located between the first and second hydrophobic domains, two potential N-linked glycosylation sites were presented. Interestingly, highly charged residues were abundantly possessed in the carboxy-terminal part of the MDV2 UL10 protein. By comparison of the amino acid sequence of the MDV2 UL10 gene with the homologues from other herpesviruses, the data might contribute for further evidence of the evolution of herpesviruses from a common progenitor and an ancient example of MDV2 belonging to the Alphaherpesvirinae subfamily. In addition, the existence of corresponding genes in human, mammalian, and avian herpesvirus genomes, suggests indirectly an important role for gM in the natural life cycle of the virus.

Amino Acid Sequence↗

PubMed1999

Identification and DNA sequence analysis of the Marek's disease virus serotype 2 genes homologous to the herpes simplex virus type 1 UL20 and UL21.

We determined 3,135 bp of the nucleotide sequence located in an 8.5 kb EcoRI-E fragment in the unique long (UL) genome region of Marek's disease virus serotype 2 (MDV2), and identified UL20 and UL21 homologous genes of herpes simplex virus type 1 (HSV-1). The UL20 and UL21 homologous genes of MDV2 are arranged colinearly with the prototype sequence of HSV-1. In addition, an open reading frame (MDV2 ORF 273), which has been identified within the UL21 homologous gene of MDV2, has no apparent relation to any other known herpesvirus genes. Northern blot analysis and reverse transcriptase polymerase chain reaction confirmed the existance of RNA transcripts related to the UL20 and ORF 273 genes in MDV2-infected cells, except no transcript related to the UL21 gene being detected. The putative protein product of the MDV2 UL20 gene had a relatively low homology but that of the MDV2 UL21 gene had a moderate homology among herpesviruses. Further, the possible functions and features of the predicted proteins encoded within the sequenced region are discussed.

Amino Acid Sequence↗

PubMed1999

Identification and sequence analysis of the Marek's disease virus serotype 2 gene homologous to the herpes simplex virus type 1 UL52 protein.

The gene of Marek's disease virus serotype 2 (MDV2) homologous to the UL52 gene of herpes simplex virus type 1 (HSV-1) was identified and characterized. The MDV2 UL52 homologous gene encodes 1,071 amino acids with a molecular weight of 118.7 kDa, which includes putative metal-binding site and overlapping region with the UL53 homologous gene. Although a putative polyadenylation signal sequence was found in the downstream of the MDV2 UL52 gene, a MDV2 UL52 DNA probe reacted only with the polycistronic 6.3 kb transcript, representing the UL52 and the downstream genes of UL53 and UL54. Transcriptional pattern of this region of MDV2 was somewhat different from corresponding regions of HSV-1 and infectious laryngotracheitis virus.

Amino Acid Sequence↗

PubMed1999

Characterization of feline CD56 molecule expressed on insect cells by the baculovirus expression system.

Recently we cloned 140 kDa form of feline CD56 cDNA. In this study, we expressed the feline CD56 molecule by the baculovirus expression system. We found that the molecule was expressed on the cell surface when examined by the indirect immunofluorescence assay using an anti-human CD56 monoclonal antibody. Immunoblotting analysis revealed that the molecular weight of the major expressed product was 140 kDa. Interestingly we found that the insect cells expressing the feline CD56 molecule aggregated, indicating that the expressed molecule mediates homophilic adhesion.

Animals↗

PubMed1999

Identification and sequence analysis of the Marek's disease virus serotype 2 homologous genes of the herpes simplex virus type 1 UL25, UL26 and UL26.5 genes.

We identified and determined the nucleotide sequence of Marek's disease virus serotype 2 (MDV2) UL25, UL26 and UL26.5 homologous genes of herpes simplex virus type 1 (HSV-1). The UL25, UL26 and UL26.5 genes of HSV-1 encode virion proteins (UL25 and UL26.5) and serine protease (UL26). The deduced amino acid sequences of the three proteins show a high degree of homology to counterparts of HSV-1. By northern blot analyses we found that four transcripts whose sizes are 4.9, 3.9, 2.0 and 1.3 kb are transcribed from the domains of MDV2 genome containing the three genes. This is the first report dealing with UL25, UL26 and UL26.5 homologues of HSV-1 in MDV serotypes.

Amino Acid Sequence↗

PubMed1999

Effects of PMA and transcription factors on ovine interferon-tau transactivation in various cell lines.

Interferon-tau (IFNtau) is produced by the trophectoderm of ruminant ungulates and its gene transactivation in vitro has so far been achieved only in human choriocarcinoma cells, JAR and JEG3. To examine if ovine IFNtau gene transactivation could be induced in cells other than JAR or JEG3 cells and its activation could be aided by the expression of a protooncogene(s), a transient transfection system was developed with the upstream region of ovine IFNtau gene that had been inserted into the chloramphenicol acetyltransferase (CAT) reporter plasmid (IFNtau-CAT). The effect of a protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), on IFNtau-CAT transcriptional activity was examined in JEG3, human embryonic kidney (293), HeLa and Vero cells. Upon transfection and PMA treatment, ovine IFNtau gene was transactivated in two unrelated cell lines, JEG3 and 293 cells. Since IFNtau-CAT was not induced in HeLa or Vero cells, HeLa and JEG3 cells were further examined for their ability to support IFNtau-CAT transactivation in a co-transfection system. While the expression of c-myc, interferon regulatory factor 1 or 2 (IRF-1 or IRF-2) was not effective, CAT activity was strongly enhanced in both JEG3 and HeLa cells with the co-transfection of c-Jun or c-Jun plus c-Fos. These data suggest that ovine IFNtau gene transcription induced by PMA is not specific for trophoblast cells and a protooncogene, c-jun, is a downstream effector of PMA activated nuclear factors in its signal transduction cascade resulting in IFNtau gene transactivaion.

Animals↗

PubMed1999

Large empty sella with an intrasellar herniation of an elongated third ventricle. Case report.

A 73-year-old female presented with a large empty sella with herniation of an elongated third ventricle concomitant with herniation of the surrounding subarachnoid space into the sella, manifesting as visual impairment and amenorrhea without galactorrhea. Magnetic resonance imaging and computed tomography cisternography clearly showed the large empty sella, without evidence of either hydrocephalus or benign intracranial hypertension, which is extremely rare.

Aged↗

PubMed1999

Serosurvey for selected virus infections of wild carnivores in Taiwan and Vietnam.

Serum samples from two leopard cats (Felis bengalensis) and four Formosan gem-faced civets (Paguma larvata taivana) in Taiwan, September 1995, and nine leopard cats in Vietnam, August and December 1997, were examined for the prevalence of antibodies against feline parvovirus, feline herpesvirus type 1, feline calicivirus and feline immunodeficiency virus. All civets and nine of 11 leopard cats were shown to have antibodies against feline parvovirus (FPV), and FPV's were isolated from mononuclear cells in the peripheral blood of the six leopard cats.

Animals↗

PubMed1998

Molecular cloning and expression of feline CD3epsilon.

The cDNA of feline CD3epsilon, one of the T-cell receptor components, was cloned from a feline T-lymphoblastoid cell line (MYA-1 cells) and peripheral blood mononuclear cells and thymocytes of cats by polymerase chain reaction. Sequencing analysis revealed that the open reading frame of feline CD3epsilon consists of 606 base pairs encoding a predicted molecular mass of 25 kDa transmembrane protein which lacks N-glycosylation site. Comparison of the predicted amino acid sequence of feline CD3epsilon with those of other mammalians' homologues revealed that a relatively low homology was present in the extracellular domain. However, the cytoplasmic domain contained several characteristic motifs highly conserved across the species. These motifs were known to be important for signal transduction upon T-cell activation or endoplasmic reticulum retention. In addition, the feline CD3epsilon protein was expressed in an insect cell line (Sf9) by a baculovirus expression system. The expression was confirmed by indirect immunofluorescence assay and immunoblotting analysis using an anti-human CD3epsilon polyclonal antibody. These results will provide additional information for understanding the feline immune system.

Amino Acid Sequence↗

PubMed1998

G protein-bound conformation of mastoparan-X: heteronuclear multidimensional transferred nuclear overhauser effect analysis of peptide uniformly enriched with 13C and 15N.

Mastoparans, a family of tetradecapeptides from wasp venom, have been used as convenient low molecular weight models of receptors coupled to GTP-binding regulatory proteins (G proteins) for the understanding of the interaction between G proteins and receptors. Sukumar and Higashijima have analyzed the conformation of mastoparan-X (MP-X) bound to the G protein alpha-subunit using proton two-dimensional transferred nuclear Overhauser effect (TRNOE) spectroscopy [Sukumar, M., and Higashijima, T. (1992) J. Biol. Chem., 267, 21421-21424]. The resultant structure, however, was not well-defined due to severe overlap of peptide proton resonances. To determine the G protein-bound conformation of MP-X in detail, we have analyzed this interaction by heteronuclear multidimensional TRNOE experiments of MP-X uniformly enriched with 15N and/or 13C. By solving the overlap problem, we were able to determine the precise conformation of MP-X bound to Gi1alpha: the peptide adopts an amphiphilic alpha-helix from Trp3 to C-terminal Leu14, and the atomic root-mean-square deviation (rmsd) values in this portion about the averaged coordinates were 0.27 +/- 0.07 A for the backbone atoms (N, Calpha, C') and 0.84 +/- 0.16 A for all heavy atoms. These values are much smaller than the corresponding rmsd values of the structures obtained from the proton 2D TRNOE spectrum alone: 1.70 +/- 0.41 A for the backbone atoms (N, Calpha, C') and 2.84 +/- 0.51 A for all heavy atoms. Our results indicate that the heteronuclear multidimensional TRNOE experiments of peptides uniformly enriched with stable isotopes are a very powerful tool for analyzing the conformation of short peptides bound to large proteins. We will also discuss the structure-activity relationships of mastoparans in activating G proteins on the basis of the precise structure of MP-X bound to Gi1alpha.

Amino Acid Sequence↗

PubMed1998

In vivo functions of the auxiliary genes and regulatory elements of feline immunodeficiency virus.

Feline immunodeficiency virus (FIV) is a widespread lentivirus of domestic cats that causes an acquired immunodeficiency syndrome (AIDS)-like disease similar to human AIDS caused by human immunodeficiency virus. FIV has a complex genome structure including structural, enzymatic and auxiliary genes and regulatory elements. In this article, we review the in vivo roles of some of these FIV auxiliary genes and regulatory elements, especially focusing on the dUTPase, vif, and ORF-A genes and AP-1 binding site in the enhancer region of the long terminal repeat, by comparison with those of other non-primate lentiviruses. These genes and elements are considered to be important for viral replication, immunological response and pathogenesis in cats.

Animals↗