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Biomedical subjects

T Onodera

Publications and source records attributed to T Onodera.

At least 37 records · Page 2Linked to original sources
PubMed2001

A serodiagnostic ELISA using recombinant antigen of swine transmissible gastroenteritis virus nucleoprotein.

A serodiagnostic ELISA utilizing the recombinant nucleoprotein (rN protein) of transmissible gastroenteritis virus (TGEV) was developed, and evaluated by examining a panel of 141 virus neutralization (VN) positive and 101 negative sera. The rN protein-based ELISA (rnELISA) appeared to be highly sensitive and specific (98.6% and 98.0%, respectively) when it was compared to the VN test. The result was similar to that of an ELISA based on purified viral antigens with showing good correlation (R=0.829). No cross-reaction was detected with antisera against porcine epidemic diarrhea virus, hog cholera virus, type A rotavirus, pseudorabies virus and swine vesicular disease virus in this ELISA. The rnELISA can be an alternative for the diagnosis of TGE with a great advantage in antigen preparation.

Animals↗
PubMed2000

Analysis of prion protein mRNA by in situ hybridization in brain and placenta of sheep.

In this study, prion protein (PrP) mRNA was focally detected in brain and placenta of pregnant sheep by Northern blot analysis. In addition, host-encoded cellular prion protein (PrP(C)) was observed in brain and placenta of the ruminant by Western blot analysis as well. Localization of PrP mRNA in pregnant sheep tissues was rendered possible with in situ hybridization. In sheep brain, PrP mRNA was predominantly localized within large neocortical neurons in the cerebrum, Purkinje cells and neurons of the molecular and granule cell layers in the cerebellum. In the placenta, signals were observed in the myometrium, including stratum longitudinale tunicae muscles and circular layers of muscular tunics. In the caruncle and placentome, signals were stronger by in situ hybridization. Since accumulation of the scrapie isoform PrP (PrP(Sc)) is required to PrP(C), these results suggest that brain and placenta of sheep may be important organs and sites for the conversion of PrP(C) to PrP(Sc).

Animals↗
PubMed2000

Enhanced expression of cellular prion protein gene by insulin or nerve growth factor in immortalized mouse neuronal precursor cell lines.

In order to understand the fundamental and putative roles of PrP(c) in the central nervous system, neuronal cell lines were established. Cells were immortalized by recombinant retrovirus vector-mediated transduction of SV40 T-antigen gene. Among these, two cell lines were selected based on their RT-PCR expressions of neuron-specific neurofilament (NF-H, NF-M) and cell morphology. These cell lines showed the properties of neuronal progenitor cells in antigenicity, morphology and responses to differentiating agents. Expression of PrP(c) was detected by immunocytochemical analysis. These cell lines responded to differentiating agents such as dibutyl cyclic AMP (dcAMP) and phorbol 12-myristate 13-acetate (PMA) before developing into neuronal-like cells. Neurite extensions were observed 20 min after incubation with the differentiating agents. Treatment with nerve growth factor (NGF) and insulin induced cell differentiation and enhanced expression of PrP gene (Prnp) mRNA and protein. The latter phenomenon was not inhibited by wortmannin, which is a specific inhibitor of phosphatidylinositol 3-kinase. These results suggest that PrP(c) plays an important role in the differentiation-mediated classic signaling pathway of neuronal cell.

Androstadienes↗
PubMed2000

Isolation and characterisation of fetal bovine brain cells in primary culture.

Primary cultures and cryopreservation procedure of bovine brain cells were established as in vitro experimental systems to study the responses of bovine brain cells to neuropathogenic agents. Brain cells were dissociated by papain from the cerebellum of a bovine fetus at 90 to 120 days old, and were cultured in different media. In a medium containing 1 per cent fetal bovine serum (FBS), neuronal cells were maintained and they formed clusters on glial and fibroblastic cell sheets. In a medium containing 10 per cent FBS, the proportion of neurones decreased, and fibroblastic and microglial cells dominated. In a serum-free medium containing epidermal growth factor, the highest neuronal proportion was obtained. Optimal cryopreservation condition for the brain tissues was investigated by changing the concentrations of DMSO and FBS. Brain cells could be cultured from cryopreserved tissue with only slightly reduced growth profiles and varying cell proportions in comparison to those prepared from fresh tissue.

Animals↗
PubMed2000

Prediction of non-responsiveness to intravenous high-dose gamma-globulin therapy in patients with Kawasaki disease at onset.

Children with Kawasaki disease (n = 82), treated with intravenous immune globulin (IVIG) at a high dose, were classified as IVIG-responsive (defervescence within 5 days of starting IVIG, n = 69) or IVIG-non-responsive (consistent fever over a 6-day period since starting IVIG, n = 13). One patient in the IVIG-responsive group had a coronary artery abnormality during the acute phase (1. 4%) versus 5 in the IVIG-non-responsive group (38.5%). Age, duration of fever before the initiation of IVIG therapy, and laboratory data obtained on admission were tested by the Mann-Whitney U test. Serum levels of C-reactive protein, total bilirubin, lactate dehydrogenase, and gamma-glutamyltranspeptidase were significantly higher (P =.002, P <.001, P <.034, and P <.038, respectively), and the hemoglobin value was significantly lower (P =.025) in patients in the non-responsive group. A multivariate analysis showed that serum levels of C-reactive protein (P =.006), lactate dehydrogenase (P =. 035), and total bilirubin (P =.046) on admission were independent correlates of the success of IVIG therapy. By defining the predictive values, patients with a C-reactive protein level >10 mg/dL, LDH level >590 IU/L, and/or hemoglobin value <10 g/dL are considered non-responsive to IVIG. Additional therapy at an early stage of the disease should be considered for patients who are predicted to be IVIG-non-responsive.

Bilirubin↗
PubMed2000

CD4(+) cells are indispensable for ulcer development in murine cutaneous leishmaniasis.

One of the most characteristic clinical features in cutaneous leishmaniasis is the development of nodules followed by ulcerations at the site of infection. Leishmania amazonensis-infected mice show similar ulcerative lesions. Leishmania-infected severe combined immunodeficiency (SCID) mice, however, have been shown to develop nonulcerative nodules. In the present study, the roles of T cells in ulceration were examined using SCID mice in cell reconstitution experiments. After development of nonulcerative nodules, SCID mice were inoculated with splenocytes from either Leishmania-infected or naive immunocompetent mice, resulting in ulceration in all mice. When naive splenocytes were depleted of CD4(+), CD8(+), or B220(+) cell populations and the remaining cells were injected into Leishmania-infected SCID mice after the development of nodules, only SCID mice inoculated with splenocytes depleted of CD4(+) cells did not show ulceration. The evidence obtained in this study clearly shows that the CD4(+) cell population is indispensable for ulceration in leishmaniasis lesions of SCID mice.

Animals↗
PubMed2000

Depressive behavior and alterations in receptors for dopamine and 5-hydroxytryptamine in the brain of the senescence accelerated mouse (SAM)-P10.

The senescence accelerated mouse (SAM) is known as a murine model of aging. SAM consists of senescence accelerated-prone mouse (SAMP) and senescence accelerated-resistant mouse (SAMR). Previous studies reported that SAMP10 exhibits age-related learning impairments and behavioral depression in a tail suspension test after 7 months. We investigated the changes in emotional behavior in a forced swimming test and in receptors for dopamine and 5-hydroxytryptamine (5-HT) in SAMP10. SAMP10 at 8 months showed an increase of immobility in the test compared with SAMR1. Treatment with desipramine (25 mg/kg, i.p., 3 days) in SAMP10 caused a decrease in immobility. In the cortex from SAMP10, [3H]quinpirole binding to D2/D3 dopamine receptors increased significantly compared with control SAMR1. In the hippocampus from SAMP10, [3H]8-hydroxy DPAT binding to 5-HT1A receptor increased. In midbrains from SAMP10, bindings of [3H]quinpirole and [3H]8-hydroxy DPAT increased. [3H]SCH23390 binding to D1/D5 receptors and [3H]ketanserin binding to 5-HT2 receptor in brain regions examined in SAMP10 were similar to those in SAMR1. The present findings represent the first neurochemical evidence of an increase of D2/D3 and 5-HT1A receptors in SAMP10. SAMP10 may be a useful model of aging associated depressive behavior.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Syntheses of chirally modified thiacalix

New chirally modified p-tert-butylthiacalix[4]arenes were synthesized via conformation- and/or regioselective etherification with ethyl bromoacetate followed by hydrolysis of the ester moiety and then subsequent amidation with (S)-1-phenyl-ethylamine or (S)-1-(1-naphthyl)ethylamine. These chiral selectors were coated with OV-17 on capillary columns to examine their ability as chiral stationary phases (CSPs) for discrimination of enantiomeric amino acid, amine and alcohol derivatives. It was found that CSP-(S)-4 prepared from cone-shaped tetra-(S)-1-phenylethylamide (S)-4 showed good to fair separations for all the samples examined. On the contrary, the corresponding CSP-(S)-14 prepared from the cone-shaped tetraamide (S)-14 of the parent p-tert-butylcalix[4]arene did not indicate any enantioseparation at all for the same samples, showing that the bridging group of the calix[4]arene ring is critical for the advent of enantioselectivity. The effect of the types and the numbers of the chiral amide groups in the chiral selectors on enantioselectivity was also discussed.

Journal Article↗
PubMed2000

Japanese scrapie cases.

Worldwide attention has been given to scrapie, because bovine spongiform encephalopathy (BSE) could be experimentally transmitted to sheep. This ovine form of BSE was clinically identical to scrapie. In Japanese scrapie cases, a majority of the diseased sheep were from Suffolk, while 8 cases were from Corriedale. It is very likely that sheep-to-sheep transmission of scrapie has taken place in Obihiro, Hokkaido. Normal prion protein may play a role in the morphoregulatory signaling pathway, which orchestrates the specificity of a particular cellular response. Over-expression of normal prion protein in mice cause neurodegenerative disorders. Recently, Prnd was identified downstream of the mouse prion protein gene (Prnp), and encodes 179 amino acids and a prion protein (PrP)-like protein designated doppel (Dpl). Dpl was upregulated in the central nervous system of two PrP-deficient lines of mice, as well as in prionless cell lines. Dpl caused neurodegeneration similar to that caused by PrP. Linked expression of Prnp and Prnd may cause several neurodegenerative disorders.

Animals↗
PubMed1999

AIM, a murine apoptosis inhibitory factor, induces strong and sustained growth inhibition of B lymphocytes in combination with TGF-beta1.

Lymphocyte proliferation is stimulated by differential combinations of various cytokines, antigens and adhesion molecules. However, mechanisms of negative regulation in lymphocytes are poorly understood despite their potential importance in controlling the balance of lymphocyte proliferation, particularly at inflammatory sites. We recently reported a novel murine soluble protein, termed AIM, which inhibits apoptosis of a variety of cell types including CD4/CD8 double-positive thymocytes. AIM is secreted specifically by macrophages and belongs to the macrophage scavenger receptor cysteine-rich domain superfamily. Here we show that in addition to the apoptosis-inhibitory effect, AIM induces strong, long-term inhibition of B lymphocyte proliferation in combination with transforming growth factor-beta1 (TGF-beta1 in vitro), resulting in almost complete block of proliferation and immunoglobulin secretion. The function of AIM as a cell growth inhibitor requires pretreatment of B cells with TGF-beta1 which appears to increase expression of the AIM receptor on the B cell surface. Thus B lymphocyte proliferation is dramatically down-regulated by sequential exposition to TGF-beta1 followed by AIM. Like many cytokines, AIM has different functions depending on the types of target cells and the combination with other cytokines.

Animals↗
PubMed1999

Allelic diversity at class II DRB1 and DQB loci of the pig MHC (SLA).

The loci encoding the beta chain of the pig major histocompatibility complex (MHC) class II antigens, SLA-DR and -DQ, have been known to exhibit a remarkable degree of allelic polymorphism. Here, to understand the generation of SLA class II polymorphism, 25 SLA-DRB1 and 24 SLA-DQB genes including newly identified 12 SLA-DRB1 and 7 SLA-DQB genes obtained from miniature pigs were analyzed based on the nucleotide and deduced amino acid sequences. Most of the allelic diversity was attributed to the variable sequences which encode a beta1 domain consisting of a beta-pleated sheet followed by an a helix. In the beta1 domain coding region, there were four GC-rich sequences, which have been considered to involve the intra-exon sequence exchange also in other gene evolutions. The first and second GC-rich sequences were alpha-like sequences, which have been shown to be a putative recombination signal, and were stably conserved among SLA-DRB1 and DQB genes. These alpha-like sequences identified in SLA-DRB1 and SLA-DQB were found to encode the first turning point of the beta-pleated sheet and the boundary between the beta-pleated sheet and the alpha helix. Analysis of clustered sequence variation also suggested intra-exon gene conversions in which the alpha-like sequences act as putative breakpoints. In addition to point mutations and selection mechanism, intra-exon gene conversions must be an important mechanism in the generation of allelic polymorphism at the SLA-DRB1 and SLA-DQB.

Alleles↗
PubMed1999

Non-ulcerative cutaneous lesion in immunodeficient mice with Leishmania amazonensis infection.

Cutaneous leishmaniasis begins as papules or nodules at the site of promastigote inoculation. The next key pathogenic event in this disease is the formation of an ulcer at this site. Leishmania infection in immunodeficient mice, however, showed non-ulcerative cutaneous lesions suggesting the involvement of the immune system in ulcer formation. Severe combined immunodeficient (SCID), recombination-activating gene 2 knockout (RAG-2-/-), and immunocompetent mice were inoculated subcutaneously with cultured L. amazonensis promastigotes. Macroscopic nodules appeared at the inoculation site within 2 weeks of infection in all the mice and gradually extended to the surrounding skin tissue. Although nodules of immunocompetent mice ulcerated within 6 weeks, immunodeficient mice did not form ulcers even after 25 weeks of inoculation. These results strongly suggest the importance of functional T and B cells in ulcer formation of cutaneous leishmaniasis and are consistent with clinical features of non-ulcerative cutaneous leishmaniasis in some AIDS patients. The present study also indicates that the L. amazonensis-infected immunodeficient mouse model might be suitable for studying the mechanisms of ulcer formation in cutaneous leishmaniasis.

Animals↗
PubMed1999

Cytolytic mechanisms involved in non-MHC-restricted cytotoxicity in Chediak-Higashi syndrome.

To determine the mechanisms responsible for the impaired lymphocyte-mediated cytotoxicity in Chediak-Higashi syndrome (CHS), we investigated the killing ability of peripheral blood lymphocytes (PBL) from three patients with CHS using several kinds of target cells that were sensitive to perforin, Fas ligand (FasL), and/or tumour necrosis factor-alpha (TNF-alpha). Freshly isolated CHS PBL did not kill K562 target cells, killing of which by normal PBL was perforin-dependent, as demonstrated by complete inhibition by concanamycin A (CMA), an inhibitor of perforin-based cytotoxicity. In contrast, the CHS PBL exhibited substantial cytotoxicity against Jurkat cells, which was only partially inhibited by CMA treatment but not by the addition of neutralizing anti-FasL or anti-TNF-alpha antibodies. IL-2-activated CHS PBL exhibited substantial levels of cytotoxicity against K562 and Jurkat cells, the levels being 74% and 83% of the respective normal control values, respectively. CMA treatment showed that while the cytotoxicity of IL-2-activated CHS PBL against K562 was largely dependent on perforin, that against Jurkat was largely not. IL-2-activated CHS PBL expressed FasL mRNA, and killed Fas transfectants. These findings indicate that CHS PBL have an ability to kill some target cells via a perforin-mediated pathway, especially when they are activated by IL-2. It was also demonstrated that CHS PBL can exert cytotoxicity against certain target cells by utilizing FasL and an undefined effector molecule other than perforin, FasL, or TNF-alpha.

Adult↗