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Biomedical subjects

T Ono

Publications and source records attributed to T Ono.

At least 631 records · Page 35Linked to original sources
PubMed1994

The MID2 gene encodes a putative integral membrane protein with a Ca(2+)-binding domain and shows mating pheromone-stimulated expression in Saccharomyces cerevisiae.

The MID2 gene whose defect (the mid2-1 mutation) results in mating-pheromone-induced death in Saccharomyces cerevisiae was cloned and its nucleotide (nt) sequence determined. The sequence showed an open reading frame (ORF) coding for a 376-amino-acid (aa) protein with an estimated M(r) of 39,104, and six potential TATA boxes and two pheromone-response elements in its 5'-upstream region. The deduced aa sequence showed that the MID2 product (Mid2p) contains a putative N-terminal signal sequence followed by a long Ser-rich region that could contain O-glycosylation sites, a potential transmembrane domain and a conserved Ca(2+)-binding domain, with the latter two located in the C-terminal half. Northern blot analysis showed that the expression of MID2 is stimulated threefold by mating pheromone. Cells that lack MID2 were able to grow normally, but died when exposed to mating pheromone, like the original mid2-1 mutant.

Amino Acid Sequence↗
PubMed1994

Identification of a unique antigen peptide pRL1 on BALB/c RL male 1 leukemia recognized by cytotoxic T lymphocytes and its relation to the Akt oncogene.

BALB/c radiation leukemia RL male 1 is an immunogenic tumor. We established bulk and cloned cytotoxic T lymphocyte (CTL) lines from regressor (BALB/c x C57BL/6)F1 (CB6F1) spleen cells that recognized RL male 1 specifically. We then obtained antigen peptide recognized by CTL from RL male 1 by acid extraction. Analysis of the acid extract by reversed-phase high performance liquid chromatography (HPLC) on a semipreparative C18 column revealed that fractions eluted in 23 min (peak a) and 26 min (peak b) showed sensitization activity on the P815 target for specific CTL. On further purification of these fractions by HPLC and direct sequencing by Edman degradation, we identified the CTL-recognizing RL male 1 peptide pRL1a (IPGLPLSL) in peak a and its possible precursor peptide pRL1b (SIIPGLPLSL) in peak b. Sequence homology indicated that these peptides were derived from the 5' untranslated region of c-akt oncogene.

Amino Acid Sequence↗
PubMed1994

Complete sequence of the Bacteroides fragilis YCH46 neuraminidase-encoding gene.

The nucleotide sequence of the Bacteroides fragilis neuraminidase-encoding gene (nanH) and its flanking regions was determined. The B. fragilis nanH open reading frame (ORF) of 1632 nucleotides encoded a neuroaminidase of 544 amino acid residues with a calculated molecular mass of 59.51 kDa. The amino acid sequence at the N-terminus of the deduced protein exhibited the common features of procaryotic signal sequences. The Asp box sequence, Ser-X-Asp-X-Gly-X-Thr-Trp, which is conserved among bacterial neuraminidases, was found at five positions in the deduced amino acid sequence. A single transcription start point was identified 88 nucleotides upstream of the nanH ORF. Northern blot analysis using an internal nanH probe revealed a single mRNA species with a length of 1.8 kb that could encode just the neuraminidase.

Amino Acid Sequence↗
PubMed1994

Selective phototoxic destruction of rat Merkel cells abolishes responses of slowly adapting type I mechanoreceptor units.

1. The fluorescent dye quinacrine which accumulates in Merkel cells in touch domes was administered to rats and the effects of excitation light irradiation on the mechanical responses of slowly adapting (SA) type I units innervating the touch domes were investigated. 2. Histological examination showed that after 10 min of irradiation degeneration was specifically localized to Merkel cells loaded with quinacrine. Nerve terminals associated with Merkel cells remained intact, even after treatment. 3. In SA type I units, responses to standard stimulation (a 100 ms ramp followed by a 2.9 s plateau of 400 microns constant displacement) decreased significantly after irradiation of the domes with quinacrine-excitation light through a 'B' filter ('B' light). With 5 min irradiation, the response decreased to 52 +/- 7% (n = 10, mean +/- S.E.M.) of the pretreated value, to 17 +/- 4% with a 10 min treatment and practically disappeared within 20 min. 4. In SA type I units with non-loaded Merkel cells, the response increased to 119 +/- 8% (n = 13) with 5 min irradiation and was 99 +/- 9% with the 10 min treatment. At around 15 min after the onset of irradiation there was a gradual decrease and within 60 min the response disappeared. 5. When responses were divided into phasic (0-120 ms after the onset of stimulation) and tonic (120-3000 ms) components, 'tonic' responses were more affected than 'phasic' ones in quinacrine-loaded SA type I units. 6. Stimulus-response curves shifted to the right and downwards in SA type I units with quinacrine-loaded Merkel cells after irradiation, but no significant change was seen in SA type I units without quinacrine. 7. Our observations are consistent with the hypothesis that Merkel cells are responsible for mechanoelectric transduction in SA type I units.

Animals↗
PubMed1994

Cloning and expression of the Bacteroides fragilis YCH46 neuraminidase gene in Escherichia coli and Bacteroides uniformis.

A neuraminidase-encoding gene nanH of Bacteroides fragilis strain YCH46 was cloned into the cosmid vector pHC79. The nanH gene was subcloned from the cosmid and was located within a 2.2-kb XhoI-KpnI fragment. Southern hybridization experiments demonstrated that the gene was present as a single copy on the bacterial chromosome. Neuraminidase activity expressed in the initial Escherichia coli clone was approximately 3600-fold lower than that expressed in B. fragilis YCH46. However, when nanH was transferred from E. coli to B. uniformis by mobilization of a shuttle plasmid, the transconjugant expressed 1100-fold higher activity than the E. coli donor did. These results suggest that modes of nanH expression in E. coli and Bacteroides are heterologous.

Bacteroides↗
PubMed1994

Tissue-specific expression of calbindin-D28K gene during ontogeny of the chicken.

The vitamin D3-dependent calcium binding protein, calbindin-D28K (CaBP-D28K), plays an important role in transepithelial calcium translocation. To evaluate its role in chick embryonic calcium metabolism, steady-state levels of CaBP-D28K mRNA in various tissues of the chick embryo were determined by Northern blot and slot blot analyses, and CaBP-D28K concentrations in the examined tissues and plasma were estimated by RIA. High levels of CaBP-D28K mRNA were found in the embryonic kidney (mesonephros) on embryonic day (E) 10 and E12 and thereafter gradually decreased until hatching. CaBP-D28K mRNA levels were low in the yolk sac until E16 but increased on E18 and reached a maximum on E20. A steady increase in CaBP-D28K mRNA levels was observed in the cerebellum during the development from E10 to post-hatching. CaBP-D28K mRNA levels in the intestine were very low during the incubation period but significantly increased on days 1 and 7 after hatching. By Northern blot analysis, CaBP-D28K mRNA was barely detectable in liver, heart, and chorioallantoic membrane of the embryonic chick. Changes in immunoreactive CaBP-D28K of each tissue paralleled observed changes in mRNA levels. In plasma, measurable levels of CaBP-D28K were found as early as E8 and were stable until E18, when 6.5-fold increase was observed compared to E16. The highest level of CaBP-D28K in plasma was found on E20 and decreased after hatching. These temporal profiles of CaBP-D28K suggest that it may play an important role in the regulation of chick embryonic calcium homeostasis.

Aging↗
PubMed1994

Effect of FR128998, a novel PAF receptor antagonist, on endotoxin-induced disseminated intravascular coagulation.

This study aimed to evaluate the effect of FR128998, (1s,6s)-1-benzyl-10-(3-pyridyl-methyl)-7-thia-10-azaspiro [5,6]-dodecan-11-one 7,7-dioxide hydrochloride, a novel platelet activating factor (PAF) receptor antagonist, on endotoxin lipopolysaccharide-induced disseminated intravascular coagulation in rats. Experimental disseminated intravascular coagulation was induced by an infusion of lipopolysaccharide at 0.25 mg/kg/h for 4 h. Simultaneous infusion of FR128998 (0.25 and 1.0 mg/kg/h) with lipopolysaccharide dose dependently inhibited thrombocytopenia, but not leukopenia. The changes in coagulation parameters of disseminated intravascular coagulation, i.e., prolongation of activated partial thromboplastin time and elevated levels of fibrinogen/fibrin degradation products, were also prevented by the treatment with FR128998. In addition, FR128998 attenuated the increase in serum tumor necrosis factor (TNF) which appeared during the initial stage of disseminated intravascular coagulation. FR128998 (10 microM) also inhibited the TNF production by peripheral blood leukocytes or alveolar macrophages stimulated by lipopolysaccharide in vitro. Furthermore, TNF production induced by PAF itself in vitro was also inhibited in the presence of FR128998. These data indicate that PAF plays a pivotal role in the development of disseminated intravascular coagulation via TNF production.

Animals↗
PubMed1994

Molecular cloning of a cDNA encoding a novel fatty acid-binding protein from rat skin.

A novel skin-type fatty acid-binding protein, termed cutaneous(C)-FABP, has been purified from rat skin and a cDNA clone for this protein has been identified. The purified protein had the ability to bind long chain fatty acids like other rat FABPs. The deduced amino acid sequence of the cDNA clone comprises residues yielding a molecular mass for the polypeptide of 15.1 kDa and exhibits around 50% identity to myelin P2 protein, adipocyte FABP and heart FABP. Our results propose that C-FABP is a new member of the FABP family.

Adipocytes↗
PubMed1994

Distinct sites of dopaminergic and glutamatergic regulation of haloperidol-induced catalepsy within the rat caudate-putamen.

Previous studies have indicated that corticostriatal glutamatergic pathways are implicated in the regulation of neuroleptic catalepsy. To obtain a better understanding of the way in which dopamine (DA) and glutamate interact within the caudate-putamen (CP) in the development of catalepsy, we investigated the regional distribution within the rat CP of the cataleptogenic effect of haloperidol and its antagonism by D(-)-2-amino-5-phosphonopentanoic acid (D(-)AP5), a selective antagonist of the N-methyl-D-aspartate (NMDA) glutamate receptor subtype. Bilateral injections of haloperidol (3 micrograms/side) into the rostral ventromedial (VM) CP induced potent catalepsy with a short latency after the injection. In contrast, only a weak cataleptic response, of slower onset, was observed after haloperidol injections into the rostral ventrolateral (VL), rostral dorsomedial (DM), or rostral dorsolateral (DL) CP, or into the nucleus accumbens. D(-)AP5 (5 micrograms/side) injected bilaterally into the dorsorostral CP (DM and DL) strongly inhibited the catalepsy induced by systemic haloperidol (1 mg/kg, i.p.), and this effect lasted longer when the drug was injected into the DM than when it was injected into the DL. D(-)AP5 did not affect haloperidol-induced catalepsy when injected into the ventrorostral (VM and VL) or intermediate dorsal CP. D(-)AP5 injected into the DM, the region most sensitive to the anticataleptic effect of the drug, had no effect on basal levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, or on the modification of these levels by haloperidol in either the DM or VM. These findings suggest that, while the catalepsy resulting from DA receptor blockade by haloperidol originates mainly from the VM, the expression of this phenomenon depends on an intact glutamatergic transmission within the dorsorostral CP. In the development of neuroleptic catalepsy, the mesencephalostriatal DAergic and corticostriatal glutamatergic pathways seem to be functionally linked through an indirect, rather than a direct, interaction.

2-Amino-5-phosphonovalerate↗
PubMed1994

High-performance liquid chromatographic analysis of methylation changes of CCGG sequence in brain and liver DNA of mice during pre- and postnatal development.

The change of the methylation of CpG in the CCGG sequence of brain and liver DNAs of mice during late fetal and suckling periods was determined by high-performance liquid chromatography using a reversed-phase column and 0.1 M phosphate buffer (pH 6.0) as the mobile phase. The tissue DNA was digested with the restriction enzyme, MspI, and was labeled at the 5'-end with [gamma-32P]ATP. The cpm% of deoxycytidine 5'-monophosphate (5mdCMP) in total CpG dinucleotides was calculated from the equation 5mdCMP/total CCGG (cpm%) = (5mdCMP)MspI,cpm/[(5mdCMP)MspI,cpm + (dCMP)MspI,cpm] x 100. The brain DNA exhibited a significant decrease in CpG methylation at prenatal day 18 but little change after birth. This marked decline of 5mdCMP in the CCGG sequence may be associated with the increase of enzymes before birth. The liver DNA showed considerable change during the late prenatal period. The observed changes of CpG methylation in liver DNA are indicative of the corresponding alterations of enzymes, multinucleate cells and hepatocytes. The results obtained indicate that both brain and liver cells have the development-associated changes in the conformation and transition of DNA around the time of birth.

Aging↗
PubMed1994

Antigenic profile of mucosal melanoma lesions.

Ten primary and 6 metastatic mucosal melanoma lesions were tested, utilizing the immunoperoxidase reaction with a panel of 26 monoclonal antibodies (MAbs). The latter included MAbs recognizing membrane-bound and cytoplasmic-melanoma-associated antigens, adhesion molecules and their receptors, and HLA Class-I and Class-II antigens. The melanoma lesions displayed differential reactivity with the panel of MAbs. Mucosal melanoma lesions differ from other types of melanoma in their antigenic profile, since they are the only type of melanoma to display a higher expression of p97 MAA, CEA-MAA and NGF-R in primary lesions than in metastatic ones. Furthermore, the pattern of HMW-MAA expression in mucosal melanoma lesions is different from that in nodular and uveal melanoma lesions and only partly resembles that observed in acral lentiginous melanoma lesions. Like other types of melanoma, mucosal melanoma lesions display a heterogeneous expression of HLA antigens, a selective loss of reactivity with some of the anti-HLA Class-I MAbs and a higher frequency of abnormalities in HLA Class-I antigen expression in metastatic than in primary lesions. Expression of HMW-MAA, 110-kDa MAA, p97 MAA, CEA-MAA, NGF-R and GD2 ganglioside in primary melanoma lesions was found to be associated with a poor prognosis. Although preliminary in nature, these results suggest that analysis of mucosal melanoma lesions with MAbs, in conjunction with information about the clinical course of the disease, will contribute to determine the biological and clinical significance of the distinct characteristics of the antigenic profile of mucosal melanoma lesions.

Antibodies, Monoclonal↗
PubMed1994

Limited diffusibility of gene products directed by a single nucleus in the cytoplasm of multinucleated myofibres.

Two types of beta-galactosidase genes, whose products are distributed in the nucleus (N beta-gal) or cytoplasm (C beta-gal), were injected with fructose intramuscularly into the quadriceps of adult mice. Regionally restricted and overlapped distributions of both gene products were observed in the myofibres. These findings indicate that N beta-gal is incorporated into the nucleus responsible for its synthesis and that C beta-gal becomes located in the vicinity of the nucleus after its synthesis. This restricted location of C beta-gal in myofibres remained unchanged during the development of infant mouse muscle. Thus, the gene products directed by the nucleus of myofibres seem to show limited diffusibility, suggesting a universal localization of subcellular domains in myofibres.

Animals↗
PubMed1994

A complete culture system for avian transgenesis, supporting quail embryos from the single-cell stage to hatching.

We report here a method to produce quail hatchlings by culture in vitro from the single-cell stage. The culture is composed of three steps. In the first step, the fertilized ovum surrounded by thick albumen obtained from the magnum is cultured for 24 hr at 41.5 degrees C in a tightly sealed 20-ml plastic cup with chicken thin albumen added to the equator level of the ovum (System Q1). In the second step, a quail egg shell, cut horizontally and emptied, is used as a bed shell. After the thick albumen is removed, the embryo with egg yolk is transferred to the bed shell and thin albumen from chicken eggs is added to fill the shell. Then, the embryo is cultured for an additional 52 hr at 37.5 degrees C while being rocked at an angle of 90 degrees at 30-min intervals (System Q2). The embryo is transferred again to a chicken bed shell and cultured at 37.5 degrees C with rocking at a 30-degree angle (System Q3). Just before hatching, the rocking of embryos is stopped. The procedure yielded a hatchability of 25%. For transgenesis, a plasmid construct containing a beta-actin-lacZ hybrid gene (pMiwZ) is microinjected into the ovum at the single-cell stage, which is cultured in vitro for 85-90 hr using Systems Q1 and Q2 consecutively. Seven out of 17 surviving embryos exhibited lacZ gene expression in embryonic tissues as detected by histochemistry. The procedure described here should be highly applicable for the production of transgenic birds.

Actins↗
PubMed1994

Hypoglossal premotor neurons with rhythmical inspiratory-related activity in the cat: localization and projection to the phrenic nucleus.

Localization and projection to the phrenic (PH) nucleus were studied in a sample of premotor neurons that directly projected to hypoglossal motoneurons (XII Mns) and showed respiratory-related patterns of activity. The experiments were carried out in cats, under pentobarbital anesthesia. In the first part of the study, the retrograde double-labeling technique was used to reveal the existence of neurons projecting to both the XII and the PH nuclei. Injection of a fluorescent dye (fast blue, FB) into the XII nucleus and another (nuclear yellow, NY) into the PH nucleus retrogradely labeled, with either FB or NY, medullary reticular neurons mainly in the regions ventrolateral to the nucleus of the tractus solitarius (vl-NTS), ventrolateral to the hypoglossal nucleus (vl-XII), and dorsomedial to the nucleus ambiguus (dm-AMB) bilaterally. In addition, some neurons in these regions were labeled with both FB and NY. In the second part of the study, unitary activity was recorded extracellularly from medullary respiratory neurons. In the regions vl-NTS, vl-XII, and dm-AMB, inspiratory neurons were found which antidromically responded to stimulation of the XII nucleus. Some of them also responded antidromically to stimulation of the PH nucleus. Averaging of rectified and integrated XII and PH nerve discharges by spontaneous spikes of single inspiratory neurons in the vl-NTS and dm-AMB regions revealed a facilitation in either XII nerve discharge or both XII and PH nerve discharges after a short latency of monosynaptic range. It is concluded that in the vl-NTS and dm-AMB regions there are inspiratory neurons that are excitatory premotor neurons projecting to XII Mns showing the respiratory-related activity. Some of them have excitatory synaptic connections to XII and PH Mns via bifurcating axons.

Animals↗
PubMed1994

Cell surface laminin-like substances and laminin-related carbohydrates of rat ascites hepatoma AH7974 and its variants with different lung-colonizing potential.

Rat ascites hepatoma AH7974 cells strongly expressed antilaminin antibody-reactive substances (laminin-like substances) and Griffonia simplicifolia isolectin B4 (GS)-reactive carbohydrate (alpha-D-galactose; alpha-Gal) on their cell surface. The alpha-Gal expression was not apparently influenced by the pretreatment of cells with methanol. The cell membrane laminin-like substances has approximate molecular weights of 150, 62 and 56 kDa in denaturating reducing conditions, of which the 62 and 56 kDa bands were stained with GS. The cell membrane molecules bearing alpha-Gal were 62 and 56 kDa and were stained with antilaminin antibody. Therefore, the major molecules bearing alpha-Gal residues of AH7974 cell membrane are considered to be laminin-like substances. To determine the role of the substances in metastasis, we selected four cell lines (74AD, 74AD-f, 74FL, 74FL-a) from AH7974 in culture. 74AD and 74FL-a are adherent lines and 74AD-f and 74FL are floating lines. All of these cell lines strongly expressed laminin-like substances, but a marked difference was found in expression of alpha-Gal, which was most strongly expressed by 74FL, followed by 74AD, and rarely by 74AD-f and 74FL-a; the staining intensity was positively correlated with their experimental lung-colonizing potential. Cell membrane laminin-like substances were 200, 97, 62, 56 and 46 kDa and among them 62 and 56 kDa molecules were glycosylated with alpha-Gal. The pretreatment of 74FL cells with antilaminin antibody or with human type A serum (containing natural antibody to alpha-Gal epitope) depressed remarkably the lung-colonizing potential of the cells. These results suggest that the expression of 62 and 56 kDa laminin-like substances with alpha-Gal residues on tumor cell surfaces is one of the determinants associated with lung-colonizing potential of these cells.

Animals↗
PubMed1994

Histochemical and morphological studies on Trichinella spiralis larvae treated with high hydrostatic pressure.

Histochemical and morphological observations were made on Trichinella spiralis larvae treated with hydrostatic pressures of 100, 150, 200 and 300 MPa using hematoxylin-eosin (HE), periodic acid-Schiff (PAS) and Azan staining. Few histochemical changes were observed in HE and PAS stained larvae after pressurization at 200 MPa and under. However, red staining by Azan changed to blue in the anterior stichosome of larvae and skeletal muscle of mice, when the hydrostatic pressure was raised from 150 to 300 MPa. At 150 and 200 MPa, boundaries among stichocytes were indistinct or irregular, and unstained areas were observed in stichocytes of larvae using Azan staining. At 300 MPa, all tissues of larvae and mouse muscle stained blue with Azan. At the same pressure, decrease in PAS positive staining of stichocytes and dilation of muscular cells were observed in larvae. It is assumed that these histochemical and morphological changes in pressurized larvae might be related to the loss of infectivity of larvae.

Animals↗