Search PubMed⌕ Search

Biomedical subjects

M Nishio

Publications and source records attributed to M Nishio.

At least 271 records · Page 15Linked to original sources
PubMed1990

Immunological relationships of simian virus 41 (SV41) to other paramyxoviruses and serological evidence of SV41 infection in human populations.

Antigenic relationships of simian virus 41 (SV41) to other paramyxoviruses were examined by immunoprecipitation of isotope-labelled SV41-infected cell lysates with specific antisera. SV41 is closely related to the group comprising human parainfluenza virus 2 (HPIV-2), simian virus 5 (SV5), parainfluenza virus 4 and mumps virus. Slight cross-neutralization was detected between SV41, HPIV-2 and SV5. Anti-SV41 activities were detected in 21 of 1116 human serum specimens, indicating that a proportion of the human population is infected with SV41. The haemagglutinin-neuraminidase of SV41 was preferentially immunoprecipitated by anti-SV41 positive sera.

Animals↗
PubMed1990

Electrophysiological and mechanical effects of calcitonin gene-related peptide on guinea-pig atria.

1. The effects of calcitonin gene-related peptide (CGRP) on mechanical and electrophysiological responses were studied in the guinea-pig atrial muscle preparations and in single cells. 2. CGRP (greater than 10(-9) M) enhanced the twitch contraction in a concentration-dependent manner in electrically driven left atria and increased heart rate in spontaneously beating right atria. The positive inotropic and chronotropic effects of CGRP were not inhibited by propranolol but were attenuated by reduction of the calcium concentration in the bathing medium. 3. In single left atrial cells, CGRP slightly hyperpolarized the resting potential but did not affect the other action potential parameters significantly. 4. Under whole-cell voltage-clamp conditions, CGRP increased the calcium inward current. The peptide also increased the steady inward current elicited by hyperpolarization and the late outward current by depolarization. 5. These results suggest that CGRP may produce the positive inotropic and presumably chronotropic effects by increasing calcium inward current. CGRP also increases the potassium permeability. Such effects on ionic currents may not produce any apparent change in the action potential conformation, due to their opposite directional actions and relatively weak potencies.

Action Potentials↗
PubMed1990

Somatostatin decreases the calcium inward current in guinea-pig atria.

1. The effects of somatostatin on mechanical and electrophysiological responses were studied in guinea-pig atrial muscle preparations and single cells. 2. Somatostatin (greater than or equal to 10(-8) M) decreased the twitch contraction in a concentration-dependent manner in electrically driven left atria and spontaneously beating right atria. However, the beating rate was not affected. 3. The negative inotropic effect of somatostatin was transient. Desensitization to this agent developed slowly during continuous exposure to the peptide. 4. In single atrial cells, somatostatin significantly shortened the action potential duration, but the resting potential and action potential amplitude were not affected. 5. Under whole cell voltage-clamp conditions, somatostatin decreased the calcium inward current without affecting the sodium and potassium currents. 6. These results suggest that somatostatin selectively acts on the calcium channel of guinea-pig atrial cells to reduce the calcium inward current, which in turn gives rise to the negative inotropic effect.

Action Potentials↗
PubMed1990

New antifungal antibiotics pradimicins FA-1 and FA-2: D-serine analogs of pradimicins A and C.

Pradimicin FA-1 was produced via directed biosynthesis with substitution of D-serine for D-alanine in the 15-position of pradimicin A. This substitution was achieved by the addition of D-serine to the culture medium of Actinomadura hibisca P157-2. Likewise, pradimicin FA-2 was co-produced along with pradimicin FA-1 when the pradimicins A and C producing strain, A. hibisca A2493 was grown in D-serine-supplemented medium. The new pradimicin analogs share a common core structure of 5,6-dihydrobenzo[a]naphthacenequinone substituted by D-serine at C-15, but differ in the disaccharide moiety at C-5. Pradimicin FA-1 has an N-methylamino sugar and D-xylose. Pradimicin FA-2 is the des-N-methyl analog of pradimicin FA-1. The in vitro and in vivo antifungal activity of the analogs was comparable to that of pradimicin A.

Amino Acids↗
PubMed1990

Water-soluble pradimicin derivatives, synthesis and antifungal evaluation of N,N-dimethyl pradimicins.

Three N,N-dimethyl pradimicins were synthesized by reductive alkylation of pradimicins A, E and FA-2 and evaluated for antifungal activity, water solubility and acute toxicity in mice. They showed in vitro antifungal activity superior to pradimicin A. N,N-Dimethylpradimicins E and FA-2 showed great improvement in water solubility and animal tolerance. N,N-Dimethylpradimicin FA-2 was effective in 3 experimental in vivo fungal infection models.

Alkylation↗
PubMed1990

Pradimicins M, N, O and P, new dihydrobenzo[a]naphthacenequinones produced by blocked mutants of Actinomadura hibisca P157-2.

Four blocked mutants which accumulated new dihydrobenzo[a]naphthacenequinone metabolites, designated pradimicins M, N, O and P, have been isolated from cultures of mutants of Actinomadura hibisca P157-2 resulting from treatment with N-methyl-N'-nitro-N-nitrosoguanidine. The structures of the four compounds were determined by spectral analysis. Pradimicins N, O and P contain D-alanine, while pradimicin M does not. The conformations at C-5 and C-6 of these compounds are different from those of the original pradimicins.

Anthracyclines↗
PubMed1990

New antifungal antibiotics, pradimicins D and E. Glycine analogs of pradimicins A and C.

New antifungal antibiotics pradimicins D and E were isolated from the culture filtrates of Actinomadura hibisca P157-2 (ATCC 53557) and its mutant A2660 (ATCC 53762). The structure of pradimicin D is N-[[(5S,6S)-5-O-[4,6-dideoxy-4-(methylamino)-3-O-(beta-D- xylopyranosyl)-beta-D-galactopyranosyl]-5,6,8,13-tetrahydro-1,6,9,14- tetrahydroxy-11-methoxy-3-methyl-8,13-dioxobenzo[a]naphthacen++ +-2-yl] carbonyl]glycine, based on spectral analyses compared to pradimicin A. Pradimicin E is the des-N-methyl analog of pradimicin D. Pradimicins D and E were equal in activity to pradimicin A in vitro against a variety of fungi and in vivo against Candida albicans A9540 in mice.

Actinomycetales↗
PubMed1990

SEM evaluation of surface cracking in glass-ionomer cement.

In an effort to assess the influence of acid etching and air drying on the production of cracks in the surface of glass-ionomer cement, the two procedures were employed over progressively increased durations, and any resulting surface cracks in the cement, were examined by replica techniques under an SEM (Scanning Electron Microscope). The results showed that acid etching alone did not produce cracks, but air-drying by compressed air produced cracks at durations between 5 and 30 sec.

Acid Etching, Dental↗
PubMed1990

Churg-Strauss syndrome (allergic granulomatous angiitis) with peculiar multiple colonic ulcers.

We treated a 40-yr-old Japanese woman who had Churg-Strauss syndrome (CSS), as diagnosed by characteristic clinical features and histological findings; in addition, peculiar multiple colonic ulcers were seen during the course of her illness. Although gastrointestinal symptoms are often seen in CSS, there are few descriptions of lesions in the gastrointestinal tract. In the English literature, the gastrointestinal manifestations of CSS include eosinophilic gastroenteritis, but the mucosa is not usually ulcerated. On the other hand, Japanese cases are characterized by multiple ulcers which are considered to be caused by ischemia secondary to the vasculitis. Most of the reported cases have not been diagnosed until laparotomy or autopsy, and our case is the first with multiple ulcers throughout the entire colon as a complication of CSS.

Adult↗
PubMed1989

Incomplete replication of human parainfluenza virus type 2 in mouse L929 cells.

Human parainfluenza virus type 2 (HPIV-2) was tested for its ability to replicate in murine L929 cells. L929 cells were non-permissive for replication of HPIV-2. Interferon produced endogenously played no role in its incomplete replication. The mechanism by which growth of HPIV-2 was suppressed in L929 cells was studied. Synthesis of virus-specific polypeptides, particularly glycoprotein(s), was suppressed in HPIV-2-infected L929 cells. The HN mRNA could scarcely be detected in virus-infected L929 cells.

Animals↗
PubMed1989

Isolation and characterization of monoclonal antibodies to human parainfluenza virus type 4 and their use in revealing antigenic relation between subtypes 4A and 4B.

Eighty monoclonal antibodies (MAbs) against parainfluenza virus type 4(PIV-4) were isolated and characterized. Of 50 MAbs against PIV-4A, 14 reacted with the nucleocapsid (NP) protein, 11 with the hemagglutinin-neuraminidase (HN) glycoprotein, 6 with the fusion (F) glycoprotein, and 19 with the matrix (M) protein. With the aid of the PIV-4A and PIV-2 specific MAbs showing cross-reactivity with PIV-4B, the structural proteins of PIV-4B were identified. gp72, p65, gp65, gp55, p53, and p40 of PIV-4B were assigned to HN, NP, Fo, F1, P, and M proteins, respectively. Based on the results, specificities of the MAbs against PIV-4B were determined. Of 30 hybridoma clones against PIV-4B, 13 clones were found to produce antibodies against the NP protein, 7 against the HN protein, and 10 against the F protein. Epitope mapping of these MAbs was performed with competitive binding assays in ELISA. According to their biological activities, the MAbs against the HN protein of either PIV-4A or 4B could be divided into three groups. The first group showed high hemagglutination inhibition (HI), hemolysis inhibition (HLI), and neutralizing (NT) activities. The second group showed high NT activity, but could not block hemagglutination. The final group showed a lower level of all activities. The MAbs against the F protein of PIV-4A and against PIV-4B were divided into two groups. Some MAbs against the F protein had high titer of NT, suggesting that the F protein had neutralizing-related epitopes. Antigenicity of the NP protein was highly conserved among subtypes of PIV-4. On the other hand, the MAbs against the HN and the F proteins showed high reactivity with the homologous subtype viruses, but low reactivity with the heterologous subtype viruses, indicating that the external glycoproteins exhibited antigenic variations between two subtypes of PIV-4. When the immunological interrelationship among various paramyxoviruses was analyzed. PIV-4 was found to be antigenically related to PIV-2, SV 5, and mumps virus.

Animals↗
PubMed1989

Extensive antigenic diversity among human parainfluenza type 2 virus isolates and immunological relationships among paramyxoviruses revealed by monoclonal antibodies.

A panel of 128 monoclonal antibodies (MAbs) directed against hemagglutinin-neuraminidase (HN), fusion (F), matrix (M), and polymerase (P) proteins, and nucleoprotein (NP) of the Toshiba strain of human parainfluenza type 2 virus (PIV2) was prepared to examine the antigenic relationships among clinical isolates of PIV2 and among paramyxoviruses by indirect enzyme-linked immunosorbent assays. The HN proteins of 18 clinical isolates of PIV2 showed extensive antigenic diversity: 23 of 33 anti-HN MAbs showed no or limited reactivity to many isolates, while other structural proteins were antigenically well conserved. Some anti-HN MAbs recognizing conserved epitopes of the isolates exhibited two types of neutralizing activity, that is, these antibodies inhibited viral infectivity through attachment inhibition or fusion inhibition. This result also showed the presence of a potential third function of the HN protein which might affect the fusing activity of the F protein besides the hemagglutinating and neuraminidase activities. Many of the anti-NP and anti-P MAbs reacted with simian virus 41 (SV41) and simian virus 5 (SV5), whereas a few reacted with mumps virus or PIV4. Two of 6 anti-F MAbs reacted with SV41. None of the 128 MAbs showed reactivity with PIV1, PIV3, Newcastle disease virus (NDV), and measles virus. This result confirmed antigenic proximity of SV5 and SV41 to PIV2 and revealed comparatively restricted immunological relatedness among PIV2, PIV4, and mumps virus.

Antibodies, Monoclonal↗
PubMed1989

Virus-specific polypeptides of human parainfluenza virus type 4 and their synthesis in infected cells.

We have studied the structural components of human parainfluenza virus type 4A (PIV-4A) and identified some virus-specific polypeptides by immunoprecipitation with polyclonal and monoclonal antibodies followed by one- or two-dimensional SDS-PAGE. HN polypeptides existed as monomer, disulfide-linked dimer, and disulfide-linked larger oligomer in cells infected with PIV-4A. Interestingly, the nonreduced NP, the nonreduced fusion, and the reduced F1 proteins migrated as doublets. Two F1 polypeptides were derived from different F1 + 2 proteins which migrated separately under nonreducing condition. In Vero cells infected with two strains of PIV-4A, two lower-molecular-weight proteins related to NP were detected. Oligopeptide patterns of the lower-molecular-weight protein were similar to those of NP protein synthesized in primary monkey kidney cells. The NP-related low-molecular-weight protein(s) was immunoprecipitated by 1 of 11 monoclonal antibodies against mumps virus NP protein. The MAb also reacted with NP proteins of PIV-2 and SV5. Thus, the epitope recognized by the MAb was common among PIV-2, PIV-4, mumps virus, and SV5, suggesting that the epitope might have an important biological function. However, the MAb did not react with the intact NP protein from cells infected with PIV-4, indicating that the epitope of PIV-4A was presented only when NP was cleaved. Phosphorylation was demonstrated for NP and P proteins.

Animals↗
PubMed1989

Membrane filters for the concentration of trace elements in water: distribution of ion pairs between membrane filter and aqueous phases.

The sorption of ion pairs on membrane filters (MFs) has been studied by taking the membrane filter as one of the homogeneous phases. The sorbability of some ionic species and the sorption abilities of different types of MF were evaluated in terms of the sorption constant defined by Ksor,CA = [(C+,A-)f]/[C+][A-], where C+, A- and (C+,A-) refer to the cation, anion and the ion pair, respectively, and f refers to the filter phase. The values of Ksor,CA were determined for many combinations of ionic complexes of cobalt(III) with pyridylazophenols, either as cations or anions, and oppositely charged organic ions having different alkyl chain lengths, with MFs made of different materials: nitrocellulose (NC; Toyo Advantec), acetylcellulose (AC; Fuji Film), regenerated cellulose (RC; Toyo Advantec) and polyethersulphone (PS; Toyo Advantec). For a given cobalt complex ion, the value of log Ksor,CA increased linearly with the increasing number of carbons in the counter ion. Membrane filters made of different materials showed different sorption abilities, the order being NC greater than PS greater than RC greater than AC. It was shown that the surface area of the MF is of greater significance than the volume of the matrix of the MF in determining the sorption constant.

Elements↗