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H Igarashi

Publications and source records attributed to H Igarashi.

At least 19 recordsLinked to original sources
PubMed1992

cDNA cloning of a novel heterogeneous nuclear ribonucleoprotein gene homologue in Caenorhabditis elegans using hamster prion protein cDNA as a hybridization probe.

The mammalian prion protein (PrPc) is a cellular protein of unknown function, an altered isoform of which (PrPsc) is a component of the infectious particle (prion) thought to be responsible for spongiform encephalopathies in humans and animals. The evolutionary conservation of the PrP gene has been reported in the genomes of many vertebrates as well as certain invertebrates. In the genome of nematode Caenorhabditis elegans, the sequence capable of hybridizing with the mammalian PrP cDNA probe has been demonstrated, predicting the presence of the PrP gene homologue in C.elegans. In this study, Southern analysis with the hamster PrP cDNA (HaPrP) probe confirmed the previous observation. Moreover, Northern analysis revealed that the sequence is actively transcribed in adult worms. Thus, we screened C.elegans cDNA libraries with the HaPrP probe and isolated a cDNA that hybridizes to the same sequence in C.elegans that hybridized with the HaPrP probe in the Southern and Northern analyses. The deduced amino acid sequence of this cDNA, however, is substantially homologous with heterogeneous nuclear ribonucleoprotein (hnRNP) core proteins rather than mammalian PrPc. The hnRNPs contain the glycine-rich domain in the C-terminal half of the molecule, which also seemed to be in PrPc at the N-terminal half of the molecule. Both of the glycine-rich domains are composed of tracts with high G + C content, indicating that these tracts may due to the hybridizing signals. These results suggest that this cDNA clone is derived from a novel hnRNP gene homologue in C.elegans but not from a predicted PrP gene homologue.

Amino Acid Sequence↗
PubMed1992

A new type of mitogenic factor produced by Streptococcus pyogenes.

A new type of mitogenic factor (protein) was purified from the culture supernatant of a strain of Streptococcus pyogenes by SP-Sephadex C-25 column chromatography, preparative isoelectric focusing and reversed-phase high-performance liquid chromatography. The purified factor, showing marked mitogenic activity in rabbit peripheral blood lymphocytes, gave a single-band staining for protein on SDS-PAGE. The molecular weight of the purified mitogenic factor was determined to be 25,370, which was different from those calculated from reported amino acid sequences deduced from 4 different nucleotide sequences of 3 kinds of streptococcal pyrogenic exotoxins (two SPEAs, SPEB and SPEC). The amino acid sequence of the N-terminal region of the purified mitogenic factor was determined to be Gln-Thr-Gln-Val-Ser-Asn-Asp-Val-Val-Leu-Asn-Asp-Gly-Ala-Ser-Lys-Tyr-Leu- Asn-Glu - Ala-, which was also different from the reported N-terminal sequences deduced from the 4 different nucleotide sequences. These data indicate that this mitogenic factor is distinct from the already described streptococcal pyrogenic exotoxins.

Amino Acid Sequence↗
PubMed1992

Rapid, sensitive, specific, and quantitative detection of human T-cell leukemia virus type 1 sequence in peripheral blood mononuclear cells by an improved polymerase chain reaction method with nested primers.

Improving on the nested double polymerase chain reaction (PCR) described previously, we have developed a new two-step PCR (TS-PCR) method for detecting more specifically the human T-cell leukemia virus type 1 (HTLV-1) proviral sequences in peripheral blood mononuclear cells (PBMC). In our TS-PCR method, the point of modification is to use optimal concentrations of primers in the first amplification step in the range of 0.01-0.025 microM. This increases sensitivity and specificity enough to detect from 1 to 10(5) copies of template DNA without radioisotopes. This method is rapid because of completion in 1 day and is also applicable for quantitative detection of clinical specimens. The data show that the quantitative detection of HTLV-1 proviral sequences by this method correlates with the anti-HTLV-1 antibody titers from serologic analysis of seropositive healthy carriers. Moreover, the TS-PCR method using each specific primer was also attempted for successful detection of other viral genomes; therefore, the principle of this method is widely suitable for routine detection of genomes in the basic and clinical microbiological fields.

Base Sequence↗
PubMed1992

Human sera from varicella-zoster virus (VZV) infections cross-react with human T cell leukaemia virus type 1 (HTLV-1): common epitopes in VZV gene 22 protein and HTLV-1 p19 gag protein.

Twenty-nine of 100 sera from patients recently infected with varicella-zoster virus (VZV) were found to cross-react with human T cell leukaemia virus type 1 (HTLV-1) antigen in the particle agglutination (PA) assay using HTLV-1 antigen-coated gelatin particles. Anti-VZV IgM antibodies were shown to be responsible for this cross-reactivity. Western blot analysis revealed that PA-positive anti-VZV sera reacted with the HTLV-1 gag p19 protein in HTLV-1-infected cells and recombinant p19 protein produced in Escherichia coli. By using a truncated p19, the cross-reactive region was located to the C-terminal 17 amino acids of p19. One oligopeptide derived from the C terminus, PQIPPPYVEPT (amino acids 115 to 125), was capable of inhibiting PA, suggesting that this peptide carries the cross-reactive epitope. A homologous sequence was found in the VZV gene 22 protein by database analysis, and the oligopeptide TNIPPPLALLR (amino acids 1330 to 1340) had the ability to inhibit PA. These findings suggest that some IgM antibodies against the VZV gene 22 protein produced in the early phase of VZV infection are cross-reactive with the HTLV-1 gag p19 protein because they recognize an antigenic determinant containing an IPPP tetrapeptide.

Agglutination Tests↗
PubMed1992

Human T cell leukaemia virus type 1 p21X mRNA: constitutive expression in peripheral blood mononuclear cells of patients with adult T cell leukaemia.

Although the p21X protein of human T cell leukaemia virus type 1 (HTLV-1) is generally thought to be expressed from a doubly spliced mRNA transcript (tax/rex mRNA) that encodes the p40tax, p27rex and p21X proteins, we have shown previously that a novel, alternatively spliced mRNA transcript (p21X mRNA) is responsible for p21X production in HTLV-1-infected cell lines. In the present study, we analysed expression of p21X mRNA and tax/rex mRNA in uncultured and cultured peripheral blood mononuclear cells (PBMCs) from eight patients with adult T cell leukaemia by using a quantitative polymerase chain reaction coupled to reverse transcription. The results demonstrated that the expression of p21X mRNA occurs constitutively in all uncultured and cultured PBMCs, whereas the expression of tax/rex mRNA is inducible in the cultured PBMCs, as described previously. In uncultured and cultured PBMCs from the one specimen in which p21X mRNA was highly expressed, the p21X protein was detectable by Western blotting. On the other hand, p27rex protein was detectable only after cultivation. These findings indicate that p21X mRNA is constitutively expressed in vivo and is responsible for production of p21X protein.

Adult↗
PubMed1992

Short sequence in L1 region of human papillomaviruses correlates with clinical pictures and grouping by cross-hybridization.

A consensus primer-mediated polymerase chain reaction devised to amplify a short sequence in L1 region (L1-PCR) efficiently detected genital human papillomaviruses (HPVs) in clinical materials. Nucleotide sequencing of the amplified fragment showed that L1-PCR is also applicable to hitherto unsequenced HPVs. By comparing the amplified 210 nucleotides HPVs were classified into six groups, which are consistent with clinical pictures and a grouping based on cross-hybridization under the stringent condition.

Base Sequence↗
PubMed1992

Maternal transmission of HTLV-1 other than through breast milk: discrepancy between the polymerase chain reaction positivity of cord blood samples for HTLV-1 and the subsequent seropositivity of individuals.

We used a nested polymerase chain reaction (PCR) to diagnose HTLV-1 carriers. The DNA isolated from the nuclear extract obtained from frozen whole blood was found appropriate for PCR study both qualitatively and quantitatively. The use of freshly frozen whole blood made the field work much easier, and the use of a nuclear extraction procedure allowed DNA isolation in just 4 microcentrifuge tubes. We could not attain sufficient sensitivity to detect a single molecule with single-step PCR, but nested PCR was confirmed to detect a single molecule/reaction. All samples of the seropositive group including 94 blood donors, 66 mothers, and 13 children were positive in the nested PCR, while none of the seronegative group, including 198 blood donors and 285 children, was positive. Although 18/717 (2.5%) cord blood samples obtained from babies born to carrier mothers were PCR-positive, none of 5 formula-fed children tested who had been PCR-positive in the cord blood gave evidence of infection later on. Furthermore, all of 4 seropositive infected children who were formula-fed had been PCR-negative in their cord blood. The results are not consistent with intrauterine infection, but suggest the presence of a perinatal or postnatal infection route other than through breast milk.

Base Sequence↗
PubMed1992

Involvement of HLA class II molecules in acquisition of staphylococcal enterotoxin A-binding activity and accessory cell activity in activation of human T cells by related toxins in vascular endothelial cells.

Human umbilical vascular endothelial cells (HUVEC) express HLA class II molecules upon stimulation with recombinant human interferon-gamma (IFN-gamma). Staphylococcal enterotoxin (SE) A (SEA)-binding assay using [125I]-SEA showed the presence of specific SEA binding in HUVEC stimulated with IFN-gamma but not in unstimulated HUVEC. Levels of HLA class II expression and SEA-binding increased as the IFN-gamma concentration and the period of stimulation were increased. Binding of [125I]-SEA to the IFN-gamma-stimulated HUVEC was reduced markedly by an anti-DR/DP MoAb. T cells produced IL-2 upon stimulation with a group of SEs (SEA, SEB, SEC, SED and SEE) in the presence HUVEC stimulated with IFN-gamma but not in the presence of control HUVEC. The level of accessory cell activity in the IFN-gamma-stimulated HUVEC was related to the level of HLA class II expression and SEA-binding activity. Antibodies to HLA class II molecules almost completely inhibited the response. These results indicate that HLA class II molecules are directly involved in the acquisition of these activities in HUVEC.

Antigen-Presenting Cells↗
PubMed1992

[Epidemiological study of Staphylococcus aureus isolated from the Japanese National University and Medical College Hospitals with coagulase typing, and production of enterotoxins and toxic shock syndrome toxin-1].

Coagulase typing, staphylococcus enterotoxins (SE) A to E or toxic shock syndrome toxin-1 (TSST = 1) production, and susceptibility to Oxacillin (MPIPC) were examined in 430 strains of S. aureus, which were isolated from clinical specimen of 43 Japanese National University or Medical College Hospitals during the one month period of August in 1990. Methicillin-resistant Staphylococcus aureus (MRSA): more than 4 mmg/ml of minimum inhibitory concentration for MPIPC in Mueller-Hinton broth containing 2% NaCl, occupied 58.6% of all the S. aureus, and more than 60% of the strains from admitted patients in all the areas of Japan except Hokkaidoh. Coagulase type II, SEC and TSST-1 producing strains were most frequently detected, 34.5% of all the MRSA. This kind of strain was distributed mainly in the eastern part of the Honshyu island, and showed high percentage especially in the Tohhoku and the Chyubu area. The second most frequent kind of MRSA was coagulase type II, no SE nor TSST-1 producing one, 15.4%, which was distributed mainly in the western part of Japan. Coagulase type IV, SEA producing MRSA strains and Coagulase type II, SEA, SEC and TSST-1 producing strains were detected in relatively high incidence, 10.3% and 8.7% respectively. Coagulase type III, no SE nor TSST-1 producing MRSAs demonstrated characteristic distribution, and were detected only in the western part of Japan, presenting the highest incidence in the Shikoku Island.

Bacterial Toxins↗
PubMed1992

[Single-dose treatment of tosufloxacin (TFLX) for acute uncomplicated cystitis].

The effectiveness of a single 300-mg dose of tosufloxacin and of 3-day treatment with tosufloxacin (300 mg daily) were compared in a prospective trial in order to clarify the cost-effectiveness of tosufloxacin for acute uncomplicated cystitis. Fifty female patients (25 patients of each group) with acute uncomplicated cystitis received one of these treatment regimens, and the clinical data and follow-up culture results were analyzed. The effectiveness rates of single-dose treatment and 3-day treatment after 3 days were 100% and 96%, respectively. The recurrence rates of single-dose treatment and 3-day treatment after 14 or 28 days were 0% (0/13 patients) and 15% (2/13 patients), respectively. There was no significant difference in the effectiveness rate and the recurrence rate between these two groups, statistically. All isolated strains were eliminated in both regimens. From these results, it is suggested that single-dose treatment of tosufloxacin is effective enough for acute uncomplicated cystitis.

4-Quinolones↗
PubMed1992

Relative abilities of distinct isotypes of human major histocompatibility complex class II molecules to bind streptococcal pyrogenic exotoxin types A and B.

The relative ability of distinct isotypes of human leukocyte antigen class II molecules to bind streptococcal pyrogenic exotoxins A and B (SPE A and SPE B, respectively) was investigated by a direct-binding assay with 125I-labeled toxin for SPE A and by a functional assay system measuring the accessory cell activity of human leukocyte antigen class II transfectants in toxin-induced T-cell activation for SPE A and SPE B. SPE A binding was observed in L cells transfected with DQw1 genes. By contrast, it was not detected in L cells transfected with DR2, DR4, DPw4 or DP(Cp63) genes. All the transfectants supported SPE-induced interleukin-2 production by human T cells except the DP transfectants for SPE B. Levels of accessory cell activity were low in the DP transfectants induced by stimulation with SPE A and in the DR and DP transfectants induced by SPE B. The results indicate that SPE A and SPE B bind well to DQ molecules, less well to DR molecules, and very weakly to DP molecules.

Animals↗
PubMed1992

Improvement of simultaneous detection of antibodies to Gag and envelope antigens of human T-lymphotropic virus type I by western immunoblot assay.

To determine seropositivity for human T-lymphotropic virus type I (HTLV-I), we attempted to improve the detection system that uses antibody to HTLV-I Env in Western immunoblotting (WB) by adding an envelope glycoprotein (gp46) purified from the culture fluid of HTLV-I-producing cells by immunoaffinity chromatography and gel chromatography. In this WB, 177 of 179 serum samples showing seropositivity in an indirect immunofluorescence assay showed positive reactions to the gp46 envelope antigen as well as to p19, p24, and p53 Gag antigens. The remaining two samples showed negative reactions to p24. False-positive results were not found for 533 indirect immunofluorescence assay-negative serum samples, although one band to p19 or p24 was observed in 46 of the 533 samples. These 46 samples did not react to p53 and gp46, suggesting that these samples belonged to the indeterminate group in accordance with the criteria proposed by the World Health Organization. Therefore, this improved WB can be used for the confirmation of seropositivity.

Blotting, Western↗
PubMed1992

Target epitope in the Tax protein of human T-cell leukemia virus type I recognized by class I major histocompatibility complex-restricted cytotoxic T cells.

A trans-acting regulatory gene product p40tax (Tax) of human T-cell leukemia virus type I (HTLV-I) is one of the main target antigens recognized by cytotoxic T lymphocytes (CTL) specific for HTLV-I. A CTL epitope within the Tax protein was identified in this report. HTLV-I-specific CD8+ CTL lines established from two HTLV-I carriers with HTLV-I-associated myelopathy or Sjögren syndrome were previously demonstrated to kill predominantly the target cells expressing HTLV-I Tax. The CTL from two patients showed significant levels of cytotoxicity to autologous target cells pulsed with a synthetic peptide of 24 amino acids corresponding to the amino-terminal sequences of the Tax protein. Allogeneic target cells were also sensitized for CTL by this peptide when the target cells have HLA-A2. Tax-specific cytotoxicity, detected as cytolysis of the target cells infected with vaccinia virus-HTLV-I recombinant expressing Tax protein, was almost completely inhibited by competitor cells pulsed with the synthetic peptide. This indicates that a major CTL epitope is present in this peptide. Further analysis using shorter peptides revealed that the core sequence of the CTL epitope was LLFGYPVYV at positions 11 through 19. This sequence can be aligned with the HLA-A2-specific motifs reported recently.

Amino Acid Sequence↗
PubMed1992

Menkes' disease: report of a case and determination of eumelanin and pheomelanin in hypopigmented hair.

We report a male infant with Menkes' disease who showed, at the age of 3 months, slow growth, hair abnormalities such as pili torti and white hair, and low levels of serum copper and ceruloplasmin. The exceptionally bright portions of his hair contained eumelanin and pheomelanin at levels only half those of normal Japanese controls. After subcutaneous administration of copper-histidinate for 2 months, his scalp hair changed to dark brown.

Ceruloplasmin↗
PubMed1992

[Dynamic changes in the organophosphate metabolites of the lenses affected by endotoxin and S-antigen induced uveitis].

Using 31P-NMR spectroscopy, the authors observed dynamic changes in the organophosphate metabolites in the lenses of two groups of Lewis rats affected by experimental uveitis induced by injecting Salmonella lipopolysaccharide (n = 20) or S-antigen (n = 25). A comparative study was done on the metabolic changes, the degree of inflammation, and histological changes in the rat lenses. Dynamic changes in the organophosphate profile in the lenses were measured by 31P-NMR spectroscopy. Only inorganic phosphate showed a significant increase (p less than 0.05) related to the increased inflammation in the endotoxin group, but the lenses showed no morphological change. Choline phosphate, adenosine triphosphate, and inorganic phosphate increased significantly (p less than 0.01) in the acute stage of inflammation, but a significant decrease (p less than 0.01) was evident from the peak of inflammation, following the histological destruction of the lenses. Our results indicated that in experimental uveitis dynamic changes in the organophosphate profile of the lenses were closely related to the protecting reaction against the stress caused by inflammation. Furthermore, we theorized that the generation of the secondary cataract was associated with the decreased metabolism of the phosphate compounds.

Animals↗