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K Oguma

Publications and source records attributed to K Oguma.

At least 91 records · Page 5Linked to original sources
PubMed1993

Demonstration of antigen-specific immune response against Streptococcus sanguis.

The genetic control of Streptococcus sanguis antigen response was studied. Mice sensitized with inactivated S. sanguis organisms antigen-injected at the base of the tail developed footpad swelling. Those with an I-Ak,q,r region of H-2 showed a strong footpad response, whereas those with an I-Ab,d,s region showed a weak response to S. sanguis cell wall antigen. Footpad response was mediated by CD4+,8- T cells by using in vitro monoclonal antibody treatment. Similar evidence of genetic control was obtained with an in vitro T cell proliferation assay. However, quantitation of antibodies against S. sanguis showed that antibody production was not controlled by H-2. These results indicated that both in vivo footpad swelling and in vitro T cell proliferation responses were functions of helper (CD3+,4+,8-) T cells and controlled by the I-A region of H-2.

Animals↗
PubMed1993

The complete nucleotide sequence of the gene encoding the nontoxic component of Clostridium botulinum type E progenitor toxin.

We have analysed the genes borne on a 6.0 kb HindIII fragment cloned from the chromosome of Clostridium botulinum type E strain Mashike. This fragment, cloned within plasmid pU9EMH, contains part of the structural gene for botulinum toxin type E neurotoxin as well as the entire structural gene for a nontoxic component of botulinum type E progenitor neurotoxin gene, ent-120. ent-120 is transcribed in the same direction as the neurotoxin gene and consists of one open reading frame encoding 1162 amino acid residues. Western blotting with anti-nontoxic component sera demonstrates that ent-120 encodes a protein of 120 kDa which forms part of the nontoxic component. ent-120 is homologous to an analogous gene found in botulinum type C strains (69.3% identity at the nucleotide level and 56.1% at the amino acid level). Two stretches of amino acids at the N-terminus of the ent-120 protein are highly homologous to amino acid sequences within the type E neurotoxin. The stop codon of the ent-120 gene is situated 27 nucleotides upstream from the start codon of the neurotoxin gene.

Amino Acid Sequence↗
PubMed1993

Development and evaluation of capture enzyme-linked immunosorbent assays for detection of immunoglobulin G and M antibodies to group A streptococcal antigens.

Capture enzyme-linked immunosorbent assays (ELISAs) were developed to detect immunoglobulin G and M antibodies to group A streptococcal (GAS) antigens, streptolysin O, streptokinase, and group A carbohydrate. The sensitivities and the specificities of the IgM capture ELISAs to each GAS antigen were high enough to distinguish the patients with GAS infections (diagnosed as GAS pharyngitis or scarlet fever) from the control groups (healthy people and patients with pharyngitis from whom GAS could not be isolated). On the other hand, the specificities of the IgG capture ELISAs were not very effective in diagnosis of GAS infections. When the capture ELISA and an indirect ELISA detecting IgM antibodies to group A carbohydrate were compared, false-positive reactions due to rheumatoid factor occurred in the indirect ELISA, but did not occur in the capture ELISA. These results indicate that the capture ELISA works better than the indirect ELISA in detecting the IgM antibody, and that the IgM capture ELISA to GAS antigen provides a rapid and highly reliable serodiagnosis for GAS infections employing only a single serum.

Adolescent↗
PubMed1993

Similarity in nucleotide sequence of the gene encoding nontoxic component of botulinum toxin produced by toxigenic Clostridium butyricum strain BL6340 and Clostridium botulinum type E strain Mashike.

The complete nucleotide and deduced amino acid sequence of the nontoxic component of botulinum type E progenitor toxin is determined in recombinant plasmid pU9BUH containing about 6.0 kb HindIII fragment obtained from chromosomal DNA of Clostridium butyricum strain BL6340. The open reading frame (ORF) of this nontoxic component gene is composed of 3,486 nucleotide bases (1,162 amino acid residues). The molecular weight calculated from deduced amino acid residues is estimated 13,6810.1. The present study revealed that 33 nucleotide bases of 3,486 are different in the nontoxic component gene between C. butyricum strain BL6340 and C. botulinum type E strain Mashike. This corresponds to the difference of 17 amino acid residues in these nontoxic component.

Amino Acid Sequence↗
PubMed1993

Two different types of ADP-ribosyltransferase C3 from Clostridium botulinum type D lysogenized organisms.

We examined production of ADP-ribosyltransferase C3 in 11 strains of Clostridium botulinum type C and D and their nontoxigenic derivatives. Antisera to C3 proteins of type C organisms divided C3 proteins roughly into at least two groups, bearing no relation to their bacterial types. The C3 gene of type D strain South African was isolated from a toxigenic phage library, and the complete sequence of the C3 gene was determined. The C3 protein of type D strain South African had 98% homology to the C3 protein of type C strain 003-9 and 66% homology to that of type D strain 1873. These results indicate that there are two types of C3 protein in type D organisms, as there are in type C organisms.

ADP Ribose Transferases↗
PubMed1993

[Lipid composition of Helicobacter pylori].

In H. pylori, we examined the composition of total lipids. In thin-layer chromatography, three kinds of glycolipids were detected, which were named as G-1, G-2 and G-3. G-3 contained phosphates in addition to sugars. Total lipids consisted of 6.0% neutral lipids (weight %), 20.6% glycolipids (G-1, G-2) and 73.4% phospholipids (including G-3). Total glycolipids were approximately 25% of total lipids. After methanolysis, cholesterol was detected in the hexane extractable fraction and glucose was detected by GLC in the methanol fraction after trimethylsilylation, in all glycolipids. Therefore, these glycolipids are cholesteryl glycosides. Cholesteryl glycosides are found very rarely in bacteria, and have been detected only in a few species of mycoplasmas and spirochetes.

Carbohydrate Sequence↗
PubMed1993

[Experimental animal models in Mongolian gerbils and mice].

Helicobacter pylori is an emerging candidate agent for the genesis of chronic gastritis and peptic ulcer. There have been many challenges to establish an experimental infection with H. pylori in animals. In recent, several studies reported for animal infection with this organism. One of them was the study using urinary system. The study indicated the ability of H. pylori to induce inflammation without significant low pH condition. Experimental infection in Mongolian gerbils showed that H. pylori could colonize on the surface of the gastric mucosa in animals without human. The study of nude mice by Karita et al. showed several valuable facts concerning the relation between bacterial pathogenicity and potential of bacterial colonization in stomach. The study in which remaining of bacteria was extended showed that colonization of H. pylori was affected by bacterial flora in the stomach.

Animals↗
PubMed1992

The complete nucleotide sequence of the gene coding for the nontoxic-nonhemagglutinin component of Clostridium botulinum type C progenitor toxin.

The structural gene for a nontoxic-nonhemagglutinin component of Clostridium botulinum type C progenitor toxin was found to exist on a 7.8 kb DNA fragment obtained from a type C phage DNA. The gene existed between the neurotoxin and hemagglutinin genes, and consisted of an 3588 bp open reading frame (1196 amino acid residues). It was speculated that this gene and the neurotoxin gene were transcribed by the same mRNA (polycistronic transcription) in C. botulinum organisms.

Amino Acid Sequence↗
PubMed1992

Inhibition of norepinephrine secretion from digitonin permeabilized PC12 cells by botulinum type D toxin.

Botulinum type D neurotoxin inhibited Ca(2+)-evoked norepinephrine secretion in digitonin permeabilized PC12 cells. Inhibition by the toxin required prior incubation with dithiothreitol (DTT). The inhibition was dependent on both concentration and incubation times of the toxin, and was affected by Ca2+ concentration. With less than 0.7 microM Ca2+ almost complete inhibition was observed; however, above 0.7 microM, Ca2+ stimulated additional norepinephrine release in a dose-dependent manner.

Animals↗
PubMed1992

A zinc-protease specific domain in botulinum and tetanus neurotoxins.

Neurotoxins produced by Clostridium botulinum are classified into groups (A to G) based on their serological nature. They consist of two subunits, heavy and light chains, linked by one or more disulphide bridges. The light chain is responsible for the blocking of acetylcholine release. Amino acid sequences of light chains have already been reported for botulinum toxins types A, C, D and E. Five highly homologous regions are found between these four toxins. One of these homologous regions, sequence HELIHSL, shows strong similarity with the active site of zinc-proteases. We suggest that inhibition of acetylcholine release might be associated with this protease activity.

Acetylcholine↗
PubMed1992

Cloning and whole nucleotide sequence of the gene for the light chain component of botulinum type E toxin from Clostridium butyricum strain BL6340 and Clostridium botulinum type E strain Mashike.

Chromosomal DNAs were extracted from Clostridium butyricum strain BL6340 and Clostridium botulinum type E strain Mashike. The 6.0 Kbp fragment coding for the entire light chain (L) component and the N-terminus of heavy chain (H) component of botulinum type E toxin was obtained from each extracted DNAs after digestion with HindIII. The entire nucleotide sequences for the light chain components of these cloned genes were determined, and the derived amino acid sequences were compared to each other, and with those of botulinum type A, C1, D, and tetanus toxins reported previously. The cleavage site of L and H components of type E toxin was presumed to be Arg-422. In a total of 422 amino acid residues of L component, 17 residues were different between butyricum and type E toxins, and all these differences were found within 200 residues of N-terminus of L component. On the contrary, five regions showing highly homologous sequences were found in L components among these six toxins, and one more region between botulinum type E and tetanus toxins.

Amino Acid Sequence↗
PubMed1992

Oligo-2',5'-adenylate synthetase activity in cells persistently infected with human T-lymphotropic virus type I (HTLV-I).

Spontaneous production of interferon-gamma (IFN-gamma) was shown in several T-lymphoblastoid cell lines persistently infected with human T-lymphotropic virus (HTLV-1). However, the produced IFN-gamma was not always associated with the induction of the antivirus state. The induction of oligo-2',5'-adenylate synthetase (2-5AS) by IFN was studied in five human T-cell lines persistently infected with HTLV-I (MT-1, MT-2, SMT-1, HUT 102 and OKM-2). Four cell lines are able to produce IFN-gamma spontaneously, while the OKM-2 cell line is not. Poor induction of 2-5AS was recognized in three (MT-1, MT-2 and SMT-1) of the four cell lines producing IFN-gamma, though the poor induction was improved after long-term cultivation of cells with IFN-alpha. On the contrary, in the OKM-2 cell line, significant activity of the enzyme was induced by IFN-alpha. Induction of 2-5AS was not correlated with cell growth inhibition, but with the antivirus state. Furthermore, an inverse relationship between IFN-gamma production and 2-5AS induction was demonstrated in these cell lines with the exception of HUT 102 cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1992

Antibody response to oral streptococci in Behçet's disease.

The serum antibody titers against oral streptococci were studied by enzyme-linked immunosorbent assay (ELISA) both in patients with Behçet's disease (BD) and control groups. The patients with BD showed significantly higher antibody titers to S. sanguis strains 113-20, 114-23, and 118-1 which were isolated from patients with BD, in comparison with control groups. Also, the reactions of high-titered sera to the crude cell wall and soluble (or membrane) fractions of the 113-20 strain were observed by western blot test. The sera of the patients with BD demonstrated strong bands of approximately 36 kDa, 82 kDa, and 87 kDa in the crude cell wall fractions, and many bands of 80 kDa to 150 kDa in the membrane fractions, indicating that these proteins are the ones leading the high antibody titers to this bacterium in the sera of patients with BD.

Antibodies, Bacterial↗
PubMed1991

The thapsigargin-sensitive intracellular Ca2+ pool is more important in plasma membrane Ca2+ entry than the IP3-sensitive intracellular Ca2+ pool in neuronal cell lines.

In NG108-15 cells, bradykinin (BK) and thapsigargin (TG) caused transient increases in a cytosolic free Ca2+ concentration ([Ca2+]i), after which [Ca2+]i elevated by TG only declined to a higher, sustained level than an unstimulated level. In PC12 cells, carbachol (CCh) evoked a transient increase in [Ca2+]i followed by a sustained rise of [Ca2+]i, whereas [Ca2+]i elevated by TG almost maintained its higher level. In the absence of extracellular Ca2+, the sustained elevation of [Ca2+]i induced by each drug we used was abolished. In addition, the rise in [Ca2+]i stimulated by TG was less affected after CCh or BK, whereas CCh or BK caused no increase in [Ca2+]i after TG. TG neither increased cellular inositol phosphates nor modified the inositol phosphates format on stimulated by CCh or BK. We conclude that TG may release Ca2+ from both IP3-sensitive and -insensitive intracellular pools and that some kinds of signalling to link the intracellular Ca2+ pools and Ca2+ entry seem to exist in neuronal cells.

Animals↗
PubMed1991

Detection of antibodies against Borrelia burgdorferi in patients with uveitis.

We determined the antibody response against Borrelia burgdorferi strains isolated from Japanese Ixodes ovatus and Ixodes persulcatus ticks by enzyme-linked immunosorbent assay and indirect immunofluorescence assay of serum specimens from 127 patients with uveitis. We examined samples of serum from Japanese patients with unclassified uveitis, iridocyclitis caused by herpes zoster virus, Behçet's disease, Vogt-Koyanagi-Harada syndrome, sarcoidosis, or other conditions (sympathetic ophthalmia, Posner-Schlossman syndrome and acute anterior uveitis with ankylosing spondylitis). Serum from healthy individuals and patients with Lyme disease served as negative and positive control samples, respectively. Significantly higher antibody titers were demonstrated in patients with uveitis than in control subjects. Of 29 patients with unclassified uveitis, nine (31) had significantly increased antibody titers against B. burgdorferi strain H014 by ELISA testing. Five patients also showed higher IgG and IgM responses than in three control subjects with Lyme disease. All positive controls showed joint problems characteristic of rheumatoid arthritis. One of three patients had uveitis. The patients were diagnosed as having Lyme disease on the basis of their history and serologic tests. A positive antibody response was recognized in several patients with Behçet's disease, Vogt-Koyanagi-Harada syndrome, sarcoidosis, and other conditions (acute anterior uveitis with ankylosing spondylitis), but not in control subjects.

Antibodies, Bacterial↗
PubMed1991

Platelet aggregation induced by uncommon serotypes of Streptococcus sanguis isolated from patients with Behçet's disease.

Uncommon serotypes were tested for their ability to induce aggregation in platelet-rich plasma. Both uncommon and common serotypes induced platelet aggregation in rabbit platelet-rich plasma, but serotonin release was higher with the uncommon serotypes. Aggregation at ATP release varied between uncommon and common serotypes. With human platelet-rich plasma, only uncommon serotypes showed aggregation. Differences in serotype selectivity and the rate of aggregation were noted among platelet donors. About half of the patients with Behçet's disease and 30% of health controls showed platelet aggregation. Plasma from non-responder patients with Behçet's disease inhibited aggregation of healthy responder platelets within 20 min. Thus selective binding of uncommon serotypes of Strep. sanguis to platelets might cause the vasculitis in Behçet's disease.

Adenosine Triphosphate↗