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Biomedical subjects

K Oguma

Publications and source records attributed to K Oguma.

At least 109 records · Page 6Linked to original sources
PubMed1991

A novel enzyme immunoassay for serodiagnosis of Helicobacter pylori infection.

Helicobacter pylori has recently been implicated as an etiologic agent of gastroduodenal disorders. Comparing the antibody to H. pylori in the sera of patients with that of normal controls by Western blot analysis, a unique antibody was detected in the sera of patients, which reacted with the 25-kilodalton antigen of H. pylori. On the other hand, monoclonal antibody CP3 prepared in the authors' laboratory also recognized the 25-kilodalton antigen of H. pylori. Whether the serum antibody of the patient recognized the CP3 antigen purified by monoclonal antibody CP3 was then examined. Western blot analysis showed that the patient's serum reacted strongly with the affinity-purified CP3 antigen. Using monoclonal antibody CP3, an enzyme-linked immunosorbent assay to detect CP3 antibody in sera was established. In patients with chronic gastritis and gastric ulcers, the titer of CP3 antibody was significantly higher than in normal controls and correlated with the histological grade of antral gastritis. The detection of CP3 antibody in sera is useful in the diagnosis of chronic gastritis and gastric ulcer associated with H. pylori infection and also in evaluation of the grade of gastritis.

Animals↗
PubMed1991

Binding of botulinum type Cl, D and E neurotoxins to neuronal cell lines and synaptosomes.

Clostridium botulinum 125I-labeled Cl neurotoxin bound to NG108 hybridoma cell line. Unlabeled type Cl neurotoxin inhibited the binding of the labeled Cl toxin but neither types D nor E toxin. 125I-labeled type D neurotoxin bound to rat brain synaptosomes but did not bind to NG108 cells. It is suggested that receptors for types C and D or E toxins on neuronal cell membranes are different.

Animals↗
PubMed1991

Cloning of a DNA fragment encoding the 5'-terminus of the botulinum type E toxin gene from Clostridium butyricum strain BL6340.

Chromosomal DNA was extracted from toxigenic Clostridium butyricum strain BL6340 isolated from a case of infant botulism. After digestion by EcoRI, a DNA fragment of about 1 kbp was cloned into Escherichia coli using lambda gt11, and was subcloned into pUC118. The E. coli cells transformed with this cloned fragment produced a 33 kDa protein which reacted with monoclonal antibodies recognizing the light chain (Lc) component of botulinum type E toxin. The nucleotide sequence of the cloned fragment was determined. The sequence was similar to that from botulinum type E toxin gene fragments previously determined by our laboratory (strains Mashike, Otaru and Iwanai). Several highly homologous sequences among the botulinum type A, C, E, butyricum and tetanus toxin genes were found in both translated and untranslated regions. These results suggest that the toxin gene of C. butyricum may have evolved by transfer from C. botulinum.

Amino Acid Sequence↗
PubMed1991

Colonization of Helicobacter pylori in the gastric mucosa of Mongolian gerbils.

Helicobacter pylori was orally inoculated into Mongolian gerbils. The organisms were able to colonize in the gastro-mucosal layer of the gerbils, especially in those gerbils which had mucosal lesions caused by indomethacin treatment. The pathological changes developed by H. pylori infection were restricted to the stomachs, and only slightly inflammatory cells were observed.

Animals↗
PubMed1991

Characterization of neurotoxigenic Clostridium butyricum strain by DNA hybridization test and by in vivo and in vitro germination tests of spores.

The germination of spores of a neurotoxigenic Clostridium butyricum strain (BL 6340), which was isolated from infant botulism in Italy, and that of a nontoxigenic C. butyricum type strain (NCIB 7423) were studied. The spores of BL 6340 strain were killed at 80 C for 10 min, and required the mixture of L-alanine, L-lactate, glucose and bicarbonate for their optimal germination. These characteristics are the same as those of Clostridium botulinum type E strain, but different from those of NCIB 7423 strain. In a hybridization test, however, the labeled DNAs extracted from NCIB 7423 strain highly (98%) hybridized to the DNAs of the BL 6340 strain, but little (45%) to the DNAs of C. botulinum type E strain. The biochemical properties of the BL 6340 and NCIB 7423 strains were identical, but different from those of C. botulinum type E. These data confirmed that the BL 6340 strain belongs to C. butyricum species, but that only its characteristics of toxin production, its minimum requirements for germination, and the behavior of its spores to heat treatment are the same as those of C. botulinum type E. When conventionally raised suckling mice were injected with 5 x 10(7) spores of BL 6340 strain intra- or orogastrically, botulism was not observed. However, 8- to 13-day-old mice had type E botulinum toxin in the large intestine 3 days after introduction of its spores.

Animals↗
PubMed1991

Cloning of the structural gene for Clostridium botulinum type C1 toxin and whole nucleotide sequence of its light chain component.

The toxigenicity of Clostridium botulinum type C1 is mediated by specific bacteriophages. DNA was extracted from one of these phages. Two DNA fragments, 3 and 7.8 kb, which produced the protein reacting with antitoxin serum were cloned by using bacteriophage lambda gt11 and Escherichia coli. Both DNA fragments were then subcloned into pUC118 plasmids and transferred into E. coli cells. The nucleotide sequences of the cloned DNA fragments were analyzed by the dideoxy chain termination method, and their gene products were analyzed by Western immunoblot. The 7.8-kb fragment coded for the entire light chain component and the N terminus of the heavy chain component of the toxin, whereas the 3-kb fragment coded for the remaining heavy chain component. The entire nucleotide sequence for the light chain component was determined, and the derived amino acid sequence was compared with that of tetanus toxin. It was found that the light chain component of C1 toxin possessed several amino acid regions, in addition to the N terminus, that were homologous to tetanus toxin.

Amino Acid Sequence↗
PubMed1991

Purification and characterization of ADP-ribosyltransferases (exoenzyme C3) of Clostridium botulinum type C and D strains.

By cation-exchange column chromatography followed by gel filtration or hydroxylapatite column chromatography, ADP-ribosyltransferases (exoenzyme C3) were isolated from culture supernatants of Clostridium botulinum type C strains Stockholm (CST) and 6813 (C6813) and from type D strains South African (DSA) and 1873 (D1873), and their molecular properties were compared. The purified C3 enzymes were homogeneous in polyacrylamide gel electrophoresis. The C3 enzymes existed as single-chain polypeptides with molecular masses of 25.0 to 25.5 kDa and transferred ADP-riboses to the same substrates in rat brain membrane extract. The C3 enzymes could be roughly classified into two groups with respect to amino acid composition, amino-terminal sequence, and antigenicity. One group contains the C3 enzymes of strains C6813 and DSA, and the other contains those of strains CST and D1873. The specific activity of the C3 enzyme of strain C6813 was about 15 times higher than that of the C3 enzyme of strain CST. These results indicate that the classification of the C3 molecules differs from that of the neurotoxin molecules.

ADP Ribose Transferases↗
PubMed1990

The complete nucleotide sequence of the gene coding for botulinum type C1 toxin in the C-ST phage genome.

Two DNA fragments, 3 kbp and 7.8kbp, which encode the type C1 botulinum neurotoxin gene, were obtained from toxigenic bacteriophage DNA by treatment with a restriction enzyme. They were cloned into the plasmid vectors for nucleotide sequence determination. The nucleotide sequence contained a single open reading frame coding for 1,291 amino acids corresponding to a polypeptide with a molecular weight of 149,000. The amino acid sequence of the C1 toxin has a few regions highly homologous with tetanus toxin.

Amino Acid Sequence↗
PubMed1990

Separation of toxic activity and ADP-ribosylation activity of botulinum neurotoxin D.

Neurotoxin from Clostridium botulinum type D strain South African (neurotoxin D) has shown ADP-ribosylation activity as well as toxic activity (Matsuoka, I., Sakuma, H., Syuto, B., Moriishi, K., Kubo, S., and Kurihara, K. (1989) J. Biol. Chem. 264, 706-712). Separation of these activities from each other was attempted by means of gel filtration, hydroxylapatite column chromatography, or immunoaffinity chromatography. Approximately 90% of toxic activity was recovered in each chromatography. Although ADP-ribosylation activity was incompletely separated from neurotoxin D by gel filtration, it was separated by hydroxylapatite column chromatography. In immunoaffinity chromatography with a column of Sepharose 4B coupling antibodies against botulinum ADP-ribosyltransferase, no ADP-ribosylation activity was detected by autoradiography in the unabsorbed toxic fraction. These results indicate that neurotoxin D does not have ADP-ribosylation activity.

Botulinum Toxins↗
PubMed1990

Macrophage activation by leptospiral lipopolysaccharide.

Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovars copenhageni and hebdomadis were tested for the ability to induce macrophage activation. In-vitro analysis showed that each leptospiral LPS was a potent activator to macrophages. After stimulation with the LPSs, interleukin-1 (IL-1) secretion, interferon (IFN) production and chemiluminescence (CL) response were induced. Intravenous high-dose injection of the leptospiral LPSs induced various lesions such as necrosis of the liver, and the LPSs were detected in macrophages in the liver, spleen and lymphnodes by immunohistochemical examination. Enhancement of macrophage activity in mice inoculated with low doses of leptospiral LPS was recognized. The macrophages of the LPS-treated mice showed a significantly higher bactericidal action than those of control mice. The beta-galactosidase and nitroblue tetrazolium (NBT) positive cells in macrophages of the LPS-treated mice increased significantly. In the NBT reduction test after phagocytosis of latex beads or Salmonella typhimurium, the macrophages of the LPS-treated mice showed a significantly higher activity than those of control mice.

Animals↗
PubMed1990

Suppression of interferon-induced oligo-2',5'-adenylate synthetase induction in persistent infection.

Persistent infections with several strains of mumps virus (strains Torii and Miyahara), measles virus (strains Edmonston, CAM-70, AIK-C and Schwarz) and subacute sclerosing panencephalitis (SSPE) virus (Hälle and Mantooth) were established in various cell lines (FL, KB, A549, SK-AS, 293, K562, Ramos and NC-37). Oligo-2',5'-adenylate synthetase activity was demonstrated to be only slightly induced by interferon in cytoplasmic and nuclear fractions of cell lines persistently infected with mumps virus. In these cells, resistance to vesicular stomatitis virus infection was not induced by interferon treatment. Treatment of the persistently infected cells with interferon for 10 and 24 h did not stimulate an increase in the amount of synthetase mRNA. In cells persistently infected with measles and SSPE viruses, reduced induction of the enzyme varied with host cell types. Induction of the enzyme was not found in K562, SK-AS and KB cells, but was recognized in NC-37 and FL cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1990

The nucleotide and deduced amino acid sequences of EcoRI fragment containing the 5'-terminal region of Clostridium botulinum type E toxin gene cloned from Mashike, Iwanai and Otaru strains.

Chromosomal DNAs were extracted from toxigenic three Clostridium botulinum type E strains isolated from food-borne botulism. After digestion by EcoRI, the fragments were cloned into Escherichia coli by using bacteriophage lambda gt11 and screened with monoclonal antibody recognizing the light chain component of botulinum type E toxin. The fragments (about 1 kbp size) cloned from each strain were recloned into a plasmid vector pUC118. The E. coli cells transformed with the recombinant plasmids produced 33 kDa protein with or without IPTG (isopropyl-beta-D-thiogalactopyranoside) which reacted with the monoclonal antibody. The nucleotide sequences of the cloned EcoRI fragments from the three type E strains were identical and contain the 5'-terminal region of the type E toxin gene. It was also found that there exist several highly homologous nucleotide sequences among the botulinum types A, C and E, and tetanus toxin genes in both translated and untranslated regions.

Amino Acid Sequence↗
PubMed1990

[Comparison of three methods for detecting Campylobacter pylori and measurement of human antibody titers against the whole organisms].

In order to detect Campylobacter pylori in the gastric mucosa, three different methods as 1) culture of the organisms, 2) immunostaining by monoclonal antibody against the cells, and 3) urease test were compared. In the disease group, positive % of each methods was 64, 75 and 74. However, positive % common to the three methods was only 48. The corresponding rate of culture and urease tests, and that of culture and staining methods was 81% and 60%, respectively. Therefore, it was concluded that urease test was a useful method, and that the three methods were necessary to confirm the existence of the organisms in the gastric mucosa. Total positive % of culture and staining methods in disease and control groups was 77 and 31, respectively, indicating that positive % of the disease group was much higher than that of the control group. Anti C. pylori titer was compared between culture-positive and culture-negative patients by ELISA. The titer of the former was significantly higher than that of the latter.

Antibodies, Bacterial↗
PubMed1990

Cloning and complete nucleotide sequence of the gene for the main component of hemagglutinin produced by Clostridium botulinum type C.

In Clostridium botulinum types C and D, phage conversion to toxin and hemagglutinin (HA) production has been reported. DNA was extracted from a converting type C Stockholm phage, c-st, and a fragment (7.8 kilobase pairs) coding for the parts of both toxin and HA was cloned. The gene for HA was recloned, and the complete nucleotide sequence was determined. The molecular mass of this gene product was 33 kilodaltons, and it showed HA activity. The HA preparation partially purified from a type C Stockholm culture demonstrated two major bands (33 and 53 kilodaltons) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with or without reducing agent. The amino acid sequence of the N terminus of the 33-kilodalton component of the native HA preparation, which was determined by a direct protein microsequencing procedure, was identical to that deduced from the nucleotide sequence of cloned HA gene. These data indicate that the cloned gene product (33 kilodaltons) is an important component of HA.

Amino Acid Sequence↗
PubMed1990

Biological effects of leptospiral lipopolysaccharide to mouse B, T and NK cells.

Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovars copenhageni and hebdomadis were tested for the biological effect to mouse B, T and NK cells. Each leptospiral LPS was a potent mitogen for spleen B cells. Activation of the cells was also expressed by polyclonal B cell activation. In contrast, mitogenicity for T cells, induction of interleukin-2 (IL-2) secretion in T cells and increase of tumor-killing activity and chemiluminescence in NK cells were not observed after stimulation with leptospiral LPS. After intravenous injection of leptospiral LPS in mice, the spleen and lymphnodes were examined by histocytochemical technique. Increase of Ig-bearing lymphocytes was recognized while decrease of T cells was observed in the lymphoid organs. Mitogenic response to PHA, Con A and PWM decreased with relation to the T cell depletion. In conclusion, it is apparent that leptospiral LPS possess marked immunological potencies on B cells but not T and NK cells. The biological effects of leptospiral LPS were common ones as LPS but the level was considered to be different from classical LPS such as Escherichia coli LPS.

Animals↗
PubMed1989

Immuno-crossreactivity between botulinum neurotoxin type C1 or D and exoenzyme C3.

Botulinum neurotoxin type D and exoenzyme C3 have been separately purified from Clostridium botulinum strain D-1873 to apparent homogeneity. Both ADP-ribosylated a rat liver cytosolic protein of 24 kDa. The N-terminal amino acid sequence of C3 was determined and showed a low degree of homology with those of the light and heavy chains of neurotoxins of various types which have been reported previously. However, a polyclonal antibody raised against C3 cross-reacted with the light chains, but not with the heavy chains, of type C1 and D neurotoxins. Furthermore, a monoclonal antibody recognizing the light chains of type C1 and D neurotoxins interacted with C3. These results suggest that the light chain of type C1 or D neurotoxin and exoenzyme C3 share at least one epitope in common with each other.

ADP Ribose Transferases↗