Search PubMed⌕ Search

Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 577 records · Page 32Linked to original sources
PubMed1990

Interleukin-2 induces motility of human lymphocytes, but not their mobility.

Interleukin-2 induces cytotoxic and antitumor activities of human lymphocytes. For the expression of these activities, the cytoskeletal system is probably activated. This study was do;ne to find if interleukin-2 causes cell movement. Lymphocytes were incubated with interleukin-2, and their morphology and motile activities were studied. After 72 hr of incubation, some 29% of lymphocytes were larger than before; nucleoli had formed and the microvilli were well-developed. The membrane potential of the lymphocytes increased during incubation. Motility under agar after 3 days of incubation with interleukin-2 was examined. Cells aggregated in clumps in the incubation well, and migration was not observed. When mobility was examined with Boyden's method, fewer cells incubated with interleukin-2 migrated than in control preparations. Cells incubated with interleukin-2 were extracted with Triton X-100. The extract obtained had three more bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than the controls. The band were at the positions for the molecular weights of 270,000-300,000. We concluded that interleukin-2 activated the motility of lymphocytes, but not their mobility.

Cell Aggregation↗
PubMed1990

Effect of chemical carcinogens on cholesterol biosynthetic pathways in the skin of mice.

The metabolism of zymosterol and mevalonic acid was studied in vitro using the skin homogenates of 3-methylcholanthrene (3MC), diazacholesterol-treated and untreated mice. In normal mouse skin only lathosterol was a major metabolite and the other metabolites, cholesta-5,7,24-trien-3 beta-ol, desmosterol, cholesterol and 7-dehydrocholesterol were much less abundant. However, in the skin homogenate of mice treated with 3MC lathosterol production was depressed, while the production of cholesta-5,7,24-trien-3 beta-ol and desmosterol was significantly increased, the cholesterol level being normal or a little higher. In contrast, in the skin homogenate of mice administered diazacholesterol the production of both lathosterol and cholesterol was almost completely blocked with the slightly increased production of cholesta-5,7,24-trien-3 beta-ol and desmosterol. The metabolism in vitro of [2-14C]-mevalonic acid was quite similar to that of zymosterol, and no additional product which might possibly have been produced by the Kandutsch-Russell pathway was observed. Two pathways for cholesterol biosynthesis, therefore, may exist in mouse skin; the first is lanosterol----zymosterol----5 alpha-cholesta-7,24-dien-3 beta-ol----lathosterol----7-dehydrocholesterol----cholesterol, and the second by Bloch: lanosterol----zymosterol----5 alpha-cholesta-7,24-dien-3 beta-ol----cholesta-5,7,24-trien-3 beta-ol----desmosterol----cholesterol. When mouse skin is treated with 3-MC the former pathway is virtually blocked and the latter is stimulated, keeping the level of cholesterol in the tissue constant or a little higher than normal, which seems to be a significant change in the early stage of chemical carcinogenesis.

Animals↗
PubMed1990

Molecular cloning and partial DNA sequencing of the collagenase gene of Vibrio alginolyticus.

DNA fragments Vibrio alginolyticus chemovar iophagus, at least 7 kb in length, were ligated to Escherichia coli expression vectors. Three clones of Escherichia coli HB101 (pLCO-1, pLCO-2, pLCO-3) were obtained by the colony immunoblotting method using anti-collagenase antibody. In Escherichia coli, all these genes produced collagenase antigens which were detected with Western blotting. The amino acid sequence of chemically purified collagenase fragments was also analyzed. An approximately 2.5 kb DNA fragment of the pLCO-1 clone was sequenced, and we found that portions of the deduced amino acid sequence of the chemically analyzed fragments. Therefore, it is highly probable that the gene studied in the present experiment is truly a collagenase structural gene.

Amino Acid Sequence↗
PubMed1990

The microbial flora from root canals and periodontal pockets of non-vital teeth associated with advanced periodontitis.

Microflora from root canals and periodontal pockets of periodontally affected teeth were compared in order to elucidate the as yet unknown relationship between pulpal and periodontal disease. Caries-free teeth affected with advanced periodontitis and diagnosed as clinically dead by electric pulp testing were selected. The root canals and periodontal pockets were sampled, and the bacterial flora examined by both culture and interference microscopy. The results indicated that the aerobe/anaerobe ratio in the periodontal pocket was 0.23, while it was 0.0022 in the root canal, the large predominance of obligate anaerobes reflecting the anaerobic environment found in the root canal. Morphological classification obtained from interference microscopy showed similar proportions of morphotypes in the two sites. Results of anaerobic culture demonstrated a significantly higher rate of detection of facultative Streptococcus bacteria in the periodontal pocket than in the root canal. The predominant bacterial species common to both regions were Streptococcus, Peptostreptococcus, Eubacterium, Bacteroides, and Fusobacterium for obligate anaerobes. As for facultative anaerobes, Actinomyces and Streptococcus were detected predominantly in the periodontal pocket. The occurrence of micro-organisms common to both sites in this study suggests that the periodontal pocket may be a possible source of root canal infections.

Actinomyces↗
PubMed1990

A method of determining residual monomer in acrylic resin using methyl ethyl ketone.

An improved method of extraction of residual monomer from acrylic resin has been described for determination of the concentration of residual monomer by gas chromatography. Four kinds of organic solvent selected according to their physicochemical properties (methanol, N,N-dimethylformamide, ethyl acetate and methyl ethyl ketone) were tested for their capacity to extract residual monomer at varying temperatures and time periods. Extraction with methyl ethyl ketone at 4 degrees C was found to be the most effective. The method is simpler and more effective than others reported so far, and therefore seems to be suitable for clinical laboratory use.

Acetates↗
PubMed1990

Complete nucleotide sequence of the structural gene for alkaline proteinase from Pseudomonas aeruginosa IFO 3455.

The DNA-encoding alkaline proteinase (AP) of Pseudomonas aeruginosa IFO 3455 was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, the gene-incorporated bacteria expressed high levels of both AP activity and AP antigens. The amino acid sequence deduced from the nucleotide sequence revealed that the mature AP consists of 467 amino acids with a relative molecular weight of 49,507. The amino acid composition predicted from the DNA sequence was similar to the chemically determined composition of purified AP reported previously. The amino acid sequence analysis revealed that both the N-terminal side sequence of the purified AP and several internal lysyl peptide fragments were identical to the deduced amino acid sequences. The percent homology of amino acid sequences between AP and Serratia protease was about 55%. The zinc ligands and an active site of the AP were predicted by comparing the structure of the enzyme with of Serratia protease, thermolysin, Bacillus subtilis neutral protease, and Pseudomonas elastase.

Amino Acid Sequence↗
PubMed1990

Protection of mice against the lethal toxicity of a lipopolysaccharide (LPS) by immunization with anti-idiotype antibody to a monoclonal antibody to lipid A from Eikenella corrodens LPS.

We produced anti-idiotype antibodies to antibody to lipid A from Eikenella corrodens. The ALA-1 monoclonal antibody (immunoglobulin M [IgM] isotype), which had already been produced in our laboratory (T. Kato, I. Takazoe, and K. Okuda, Infect. Immun. 57:656-659, 1989), had reacted strongly with lipid A from E. corrodens, Escherichia coli, and Salmonella minnesota. Four anti-idiotype monoclonal antibodies to ALA-1 (Ab1), designated A2LA-1 (IgG1 isotype), A2LA-2 (IgG2a isotype), A2LA-3 (IgG2a isotype), and A2LA-4 (IgG3 isotype), which recognized the idiotype Ab1, were produced. A2LA-1, A2LA-2, and A2LA-3 were capable of over 61% inhibition of ALA-1 reactivity to E. coli J5 lipid A in an enzyme-linked immunosorbent assay system. The sera of mice and rabbits immunized with the anti-idiotype antibodies revealed that the internal image anti-idiotype antibody induced the production of IgG antibodies that cross-reacted with or bound to lipid A. These studies indicate that A2LA-1 and A2LA-2 contained an antigenic epitope that mimicked lipid A. Immunization of mice with A2LA-1 resulted in prevention of lethal toxicity from E. coli J5 lipopolysaccharide.

Animals↗
PubMed1990

Histology of the lens in the Weill-Marchesani syndrome.

The Weill-Marchesani syndrome is a rare systemic connective tissue disease characterised by small stature, brachydactyly, ectopia lentis, and spherophakia. Three siblings with typical manifestations of this syndrome were reported. The ophthalmological findings in all these cases were spherophakia, severe myopia, a shallow anterior chamber, and narrow angle glaucoma. Two cases underwent laser iridotomy and drug treatment. In the third case the lens was removed from the eye because of injury, and this lens was examined by light and electron microscopy.

Adolescent↗
PubMed1990

Cardiac sports rehabilitation for patients with ischemic heart disease.

This paper summarizes data gathered from an 8 years sports cardiac rehabilitation program at Kyoto University and satellite hospital (Takeda Hospital). In total, 185 patients were rehabilitated under our original program with no serious cardiac accidents. Compliance was 58.2% after 6 months of this rehabilitation. In patients selected to evaluate the value of rehabilitation, exercise study with treadmill and 201Tl scintigraphic study showed improvement in exercise tolerance (in 58% of patients) and in perfusion on exercise (in 40%). Coronary angiographic study showed regression of arterial narrowing in 16% of the patients studied. We conclude that in addition to emotional and psychological support, our sports cardiac rehabilitation is safe and effective in improving exercise tolerance and cardiac perfusion.

Coronary Angiography↗
PubMed1990

[A rapid diagnosis (SK-013) for periodontitis based on the enzymatic activity of periodontopathic bacteria. Study on the characterization of the SK-013 and the enzyme specificity].

We present studies for development of an enzymatic diagnostic method for periodontitis. A rapid and sensitive diagnostic method named SK-013 was provided by Sunstar Inc. to evaluate the peptidase activities specifically derived from periodontopathic bacteria such as Bacteroides gingivalis, Bacteroides forsythus and Treponema denticola and some strains of Capnocytophaga species. The results obtained indicated the specificity of the enzymatic reaction in this system.

Bacteroides↗
PubMed1990

[A rapid diagnosis (SK-013) for periodontitis based on the enzymatic activity of periodontopathic bacteria. The relationship between the enzymatic activity (SK-013) and B. gingivalis, B. forsythus, T. denticola in subgingival microflora].

SK-013 was developed for rapid detection of the peptidase activity in subgingival plaque samples. The purpose of this study was to determine whether SK-013 could be a marker for the presence of periodontopathic bacteria including Treponema denticola, Bacteroides gingivalis and Bacteroides forsythus which produce trypsin-like enzyme. Subgingival plaque samples were taken with 3 paper points from 10 clinically healthy sites and 30 periodontal diseased sites. The SK-013 activity of plaque sample was assayed and the cells of T. denticola, B. gingivalis and B. forsythus in the sample were counted by immunofluorescence technique. In diseased sites, both the SK-013 activity and the cell counts of these organisms were significantly higher than those in healthy sites. The proportions and cell counts of these organisms and the SK-013 activity were closely correlated with clinical parameters including Gingival Index, Plaque Index, and Probing depth. The correlation between the presence of these organisms and the SK-013 activity was significant. Correlation coefficients between the presence of T. denticola and the SK-013 activity were higher than those of others.

Bacteroides↗
PubMed1990

[A rapid diagnosis for periodontitis based on the enzymatic activity of periodontopathic bacteria. The application of the SK-013 to the judgement on the effect of initial preparation].

The purpose of the present study was to examine the diagnostic value of the SK-013 (Sunstar, Osaka) in evaluating the effect of initial preparation. The SK-013 is a highly sensitive reagent to measure peptidase activity specifically produced by Bacteroides gingivalis. Bacteroides forsythus, and Treponema denticola. Thirty-six sites in 16 periodontitis patients were monitored in this study. The clinical status of each site was assessed using the clinical indices such as gingival index (GI), plaque index (PII), probing depth (PD), and bleeding on probing (BOP). The composition of subgingival microflora in samples was determined using phase contrast microscopy. Clinical, microbiological, and enzymatic examinations were made at five separate appointments, as follows: (1) at baseline prior to plaque control instruction; (2) 4 weeks following plaque control instruction; and (3) 2, 4, 8 weeks following scaling and root planing of periodontal sites. The results of these examinations were compared statistically. The correlation was positive between the total counts of bacteria including spirochetes and motile rods and the enzymatic activity identified using the SK-013. Also the enzymatic profile was highly correlated with microbiological findings other than clinical indices. These results show that the SK-013 is a clinically useful diagnostic method for assessing the effect of initial periodontal therapy.

Bacteroides↗
PubMed1990

Genetic control by I-A subregion in H-2 complex of incidence of streptozocin-induced autoimmune diabetes in mice.

An experimental autoimmune diabetes in mice characterized by delayed-onset hyperglycemia with lymphocytic infiltrations of the pancreatic islets can be induced by multiple administrations of low doses of streptozocin (STZ). We report on the influence of the MHC (H-2 complex) on this autoimmune diabetes by comparing the susceptibilities of various congenic and recombinant strains with a B10 background. In congenic strains, C57BL/10 (H-2b) and B10.BR (H-2k) mice showed a high incidence of diabetes, whereas B10.D2 (H-2d) and B10.S (H-2s) mice showed a low incidence. Therefore, we suggest that the H-2 complex influences diabetes susceptibility and that both b and k are high-susceptibility alleles, whereas d and s are low-susceptibility alleles. In recombinant strains, those with the same haplotypes on the K, E, S, and D subregions of the H-2 complex showed undefined (high and low) susceptibilities, indicating that the diabetes-susceptibility genes are located outside these loci. Strains possessing I-Ab or I-Ak gene products (C57BL/10, B10.BR, B10.TL, B10.A, and B10.A(2R] showed high incidences, whereas strains possessing I-Ad or I-As (B10.D2, B10.S, B10.S(7R), B10.S(9R), and B10.GD) showed low incidences. In addition, administration of anti-I-A monoclonal antibody prevented the manifestation of diabetes in STZ-administered mice. Passive transfer of STZ-administered T lymphocytes to mice given minute doses of STZ induced significant hyperglycemia. This successful transfer was only observed in H-2-compatible mice. Thus, we conclude that one gene coding for susceptibility to this experimental diabetes was located in the I-A subregion within the H-2 complex.

Animals↗
PubMed1990

Expression of decay-accelerating factor on hematopoietic progenitors and their progeny cells grown in cultures with fractionated bone marrow cells from normal individuals and patients with paroxysmal nocturnal hemoglobinuria.

Decay-accelerating factor (DAF), a complement-regulating glycoprotein, has been shown to be expressed on hematopoietic progenitors and their progeny cells in normal individuals but not on abnormal cells in patients with paroxysmal nocturnal hemoglobinuria (PNH). Fluorescence histograms of bone marrow cells showed the heterogeneity of DAF expression on their cell membranes, suggesting mixed hematopoietic cell populations in PNH. We have previously shown that DAF is a maturational protein expressed on normal hematopoietic cells. In order to elucidate the relationship between DAF expression and cell maturity in PNH, we fractionated bone marrow cells according to amount of DAF and cultured these cells in methylcellulose for clonal assay of erythroid burst-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM), followed by reanalysis of DAF expression on their progeny. The matured cells from the bursts/colonies in cultures with DAF-negative PNH marrow cells had no or little DAF, but those grown from DAF-positive PNH progenitors showed nearly as much of this factor as those grown from normal progenitors. These results clearly indicate that there are at least two distinct populations of hematopoietic progenitors with respect to the membrane expression of DAF and that abnormalities occur at the level of the stem cell in PNH.

Bone Marrow↗
PubMed1990

Inhibitory effects of aqueous extract of cacao bean husk on collagenase of Bacteroides gingivalis.

Natural materials containing tannin were examined to determine whether they possessed any inhibitory activity against collagenase obtained from the culture supernatant of Bacteroides gingivalis. The collagenolytic activity was determined with Collagenokit CLN-100 (Collagen Technological Co., Tokyo) using FITC-conjugated collagen type 1. Among the test samples, only an aqueous extract of cacao (Theobroma cacao) bean husk strongly inhibited the bacterial collagenase. This inhibitory potency was at the same level as that of tetracycline-HCl.

Cacao↗
PubMed1990

Clinical, microbiological, and immunological studies following initial preparation in adult periodontitis.

This study investigated the clinical, microbiological and immunological changes induced in adult periodontitis by initial preparation. Microflora in periodontal lesions was mainly examined by cultural methods, and serum IgG antibody levels were measured by an enzyme linked immunosorbent assay. Black-pigmented gram negative anaerobes, especially Porphyromonas (Bacteroides) gingivalis, was predominant in periodontal pockets with adult destructive periodontitis. Significantly elevated serum IgG antibody levels to P. gingivalis was found in high frequency, and these serum IgG antibody levels correlated with the presence of P. gingivalis in periodontal pockets, not with other bacteria tested. Total-CFU was significantly reduced and clinical conditions were improved after supragingival plaque control, but the microflora themselves showed few changes. Although reduction of total-CFU and changes in microflora were observed following scaling and root planing, it was found to be difficult to completely eliminate periodontopathic bacteria from periodontal pockets. Although serum IgG antibody levels to P. gingivalis was significantly reduced following initial preparation, the levels were still elevated from those of the controls. It was found that the presence of P. gingivalis was correlated with clinical conditions, including bleeding on probing and residual pocket depth following initial preparation.

Adult↗