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S Hamada

Publications and source records attributed to S Hamada.

At least 289 records · Page 16Linked to original sources
PubMed1989

Homology between surface protein antigen genes of Streptococcus sobrinus and Streptococcus mutans.

The structural gene (pag gene) for a 210 kDa protein antigen of Streptococcus sobrinus serotype g was cloned and compared with that (pac gene) of a 190 kDa protein antigen of Streptococcus mutans serotype c. Immunodiffusion analysis revealed that the product of the pag gene immunologically cross-reacted with that of the pac gene. Southern blot and nucleotide sequence analyses revealed that a significant homology existed between the middle regions of the two structural genes.

Amino Acid Sequence↗
PubMed1989

Analysis of human IgG and IgA subclass antibody-secreting cells from localized chronic inflammatory tissue.

The chronic inflammatory diseases in humans have been intensively investigated, however the immune mechanisms underlying diseases such as rheumatoid arthritis (RA), inflammatory bowel disease, and periodontal disease (PD) remain elusive. In this study, we have analyzed the distribution of IgM, IgG, and IgA secreting cells with emphasis on the IgG and IgA subclasses among mononuclear cell populations isolated from gingiva at different stages of PD. Surgically removed tissues were treated with Dispase to gently dissociate cells and the Ficoll-Hypaque gradient centrifugation was used to enrich for viable mononuclear cells rich in lymphocytes, macrophages, and plasma cells. The total numbers of plasma cells increased with the severity of disease. Immunofluorescence analysis showed that most Ig-containing cells were of the IgG isotype; however, significant numbers of IgA-positive cells but few IgM-positive cells were seen. This isolation procedure allowed analysis, at the single cell level, of the distribution of IgG and IgA subclasses of antibody-secreting cells with monoclonal antibodies to human IgG and IgA subclasses. For this, we selected four monoclonal anti-IgG subclass (anti-gamma 1, -gamma 2, -gamma 3, and -gamma 4) antibodies with no subclass cross reactivity for use in the enzyme-linked immunospot assay. Analysis of slight, moderate, and advanced stages of PD showed a progressive increase in spotforming cells (SFC) numbers, and the major isotype of SFC was IgG followed by IgA. The major IgG subclass SFC seen was IgG1 followed by IgG2 whereas similar numbers of IgG3 and IgG4 SFC were observed, a pattern also seen with cells from synovium of RA patients and in mitogen-triggered spleen and PBMC. In terms of the IgA subclass distribution, IgA1 predominated in moderate stages, whereas a selective increase in IgA2 SFC were seen in the more advanced stage of PD. These results show that significant numbers of viable plasma cells/Ig-secreting cells can be isolated from inflamed gingival tissues. Further, careful analysis has shown that IgG subclass responses in gingiva are similar to those found in synovia of RA subjects, and in stimulated PBMC and spleen. However, it should be noted that the number of IgG4- and IgA2-secreting cells increased in the advanced stage of PD.

Antibody-Producing Cells↗
PubMed1989

Problem of size dependence in fluorescence DNA cytometry.

The relationship among fluorescence intensity, area, thickness, and DNA concentration of DNA-bearing polyacrylamide film, stained with 50 ng/ml DAPI, was studied using an epi-illumination cytofluorometer. Measurements and theoretical analysis suggest the inevitability of the size-dependent effect on human cell nuclei in which the order of the DNA concentration is approximately 10 mg/ml, and that this effect can be virtually negated if the nuclei are stretched and flattened to less than 0.33 microns in thickness on the smears. Alternative practical ways to minimize this effect are to decrease the dye concentration of a staining solution and to make smears as thin and uniform as possible by some means such as hypotonic treatment and/or using an automatic centrifuge smearing apparatus. The size-dependent effect, nevertheless, should be taken into account particularly when determining the DNA content of different cell types and the DNA aneuploidy of tumor cells, regardless of the technique used for measurement.

Animals↗
PubMed1989

Purification and characterization of cell-associated glucosyltransferase synthesizing water-insoluble glucan from serotype c Streptococcus mutans.

Strains of Streptococcus mutans (serotypes c, e and f) were found to possess high levels of glucosyltransferase (GTase) activity, both cell-associated and in the culture medium, when grown in either sucrose-free or sucrose-containing broth media. The cell-associated GTase of S. mutans MT8148 (serotype c) was effectively extracted by treatment with 8 M-urea at 25 degrees C for 1 h. Approximately 95% of the GTase activity was solubilized by this treatment. The crude extract was purified by DEAE-Sephacel and hydroxylapatite column chromatography. For comparison, extracellular GTase was also purified from the culture supernatant of the same strain by ammonium sulphate precipitation, chromatofocusing and hydroxylapatite chromatography. The molecular masses of the cell-associated and extracellular GTase proteins were similar (156 kDa) as determined by SDS-PAGE. However, the pH optima for maximum GTase activity were different: pH 6.7 to 7.0 for the cell-associated enzyme and pH 5.5 to 6.5 for the extracellular enzyme. The product of cell-associated GTase from sucrose was almost exclusively water-insoluble glucan. On the other hand, extracellular GTase produced mainly water-soluble glucan from sucrose. This indicates that GTase synthesizing water-insoluble glucan is present primarily in a cell-associated form in serotype c S. mutans. Insoluble glucan synthesis by the cell-associated GTase from sucrose was not enhanced by addition of primer dextran T10 to the reaction mixture. The extracellular and cell-associated GTases were immunologically unrelated as determined by ELISA using monoclonal antibodies.

Chromatography↗
PubMed1989

Characterization of a cell-surface protein antigen of hydrophilic Streptococcus mutans strain GS-5.

Fourteen strains of Streptococcus mutans serotype c were examined for their cell-surface protein antigens in terms of hydrophobicity, Mr and immunochemical specificities. Thirteen strains were hydrophobic, while strain GS-5 was markedly hydrophilic as compared to the other strains tested. Cell-surface protein antigens were then analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western immunoblotting. A protein antigen of Mr 190,000 (PAc) was found in cell extracts and culture supernatants of all the hydrophobic strains. Neither culture supernatant nor cell extract of strain GS-5 contained PAc. Strain GS-5, however, produced extracellularly a large amount of a protein of Mr 155,000 (PAGS-5) which reacted with rabbit anti-PAc serum. Immunodiffusion analysis showed that PAGS-5 lacked a part of the antigenic moieties in the PAc molecule. SDS-PAGE and radioimmunoassay showed a small amount of PAGS-5 on the cell surface of strain GS-5. These findings suggest that PAGS-5 may correspond to PAc which lacks a region participating in binding of PAc to the streptococcal cell.

Antigens, Bacterial↗
PubMed1989

Molecular characterization of a surface protein antigen gene from serotype c Streptococcus mutans, implicated in dental caries.

The complete nucleotide sequence of the gene for a cell-surface protein antigen (PAc) of Streptococcus mutans MT8148 (serotype c) was determined. The pac gene consisted of 4695 bp and coded for a 170773D protein. The pac gene product contained a putative 38 amino acid signal peptide, resulting in a 166817D mature protein. A potential promoter sequence and a putative Shine-Dalgarno sequence preceded the open reading frame. Two internal repeating amino acid sequences were present in the PAc. One repeating region located in the N-terminal region was rich in alanine, and the other located in the central region was rich in proline. Southern blot analysis under the less stringent condition (allowing up to 35% base mismatch) revealed that the probe covering the proline-rich region hybridized to DNA preparations from strains of Streptococcus cricetus, Streptococcus sobrinus and Streptococcus downei as well as Streptococcus mutans.

Amino Acid Sequence↗
PubMed1989

Cloning of a surface protein antigen gene from serotype c Streptococcus mutans.

The structural gene for a 190 kD protein antigen (PAc) of Streptococcus mutans MT8148 (serotype c) was cloned into the plasmid vector pUC118. SDS-polyacrylamide gel electrophoresis and Western immunoblotting showed that the Escherichia coli harbouring the chimaeric plasmid produced multiple polypeptides of 190-210 kD. Immunodiffusion analysis revealed that the cloned PAc had the same specific determinants as S. mutans PAc. The cloned pac gene was mapped, and its transcriptional orientation was determined by characterizing deletion mutants of the chimaeric plasmid. Southern blot analysis with the cloned gene sequence as a probe revealed the presence of a homologous sequence in DNAs from serotypes e and f S. mutans. PAc-defective mutants were constructed by inserting an erythromycin-resistance gene into the pac gene. The cell-surface hydrophobicity of the mutants was lower than that of the parent strain.

Antibodies, Bacterial↗
PubMed1989

Effect of a bacteriocin-producing strain of Streptococcus sobrinus on infection and establishment of Streptococcus mutans on tooth surfaces in rats.

The effect of bacteriocin produced by Streptococcus sobrinus MT6223 on infection and establishment of Streptococcus mutans MT6222 was studied in specific pathogen-free rats. These strains were isolated from a carious lesion of a single subject. S. mutans MT6222 was found to be susceptible to the growth inhibitory action of S. sobrinus MT6223. When simultaneously inoculated into the oral cavity of rats, even a small inoculum (10(5) CFU) of S. sobrinus MT6223 completely inhibited colonization of S. mutans MT6222 on the tooth surface. Also, S. sobrinus MT6223 eliminated S. mutans MT6222 when MT6223 (10(8) CFU) was inoculated 2 days after the inoculation of 10(8) CFU cells of MT6222. Similar results were obtained in dental plaque samples from the tooth surface and the fissures of the upper molars at the end of the experiment. However, when S. sobrinus MT6223 (10(8) CFU) was inoculated 2 weeks after the inoculation of S. mutans MT6222 (10(8) CFU), MT6223 coexisted with MT6222. However, the plaque samples showed that MT6223 inhibited the establishment of MT6222 on smooth surfaces, but not in fissures. In addition, MT6223 protected against subsequent infection with MT6222. However, a nonbacteriocinogenic mutant of S. sobrinus MT6223 did not inhibit the infection and establishment of S. mutans MT6222.

Animals↗
PubMed1989

Mucosal and systemic immune responses in BALB/c mice to Bacteroides gingivalis fimbriae administered orally.

A 41,000-molecular-weight fimbrial protein was isolated from freshly cultivated whole cells of Bacteroides gingivalis 381 and purified chromatographically. Salivary and serum antibody responses to the fimbriae, which had been orally administered in the presence of an acyl derivative of muramylpeptides, i.e., either N2-[(N-acetylmuramyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine [MDP-Lys(L18)] or sodium beta-N-acetyl-glucosaminyl-(1----4)-N-acetylmuramyl-L-alanyl-D-isoglu tam inyl- (L)-stearoyl-(D)-meso-2,6-diaminopimelic acid-(D)-amine-D-alanine (GM-53), or in the absence of adjuvant, were examined in BALB/c mice when administered by gastric intubation on days 0 and 1 as primary immunizations and on days 27 and 28 as booster immunizations. Gastric intubation of the fimbriae with an adjuvant significantly enhanced the production of anti-fimbria immunoglobulin A (IgA) in saliva. Subcutaneous injection of fimbriae along with an adjuvant also raised anti-fimbria IgA levels, as well as IgG levels, in saliva. Both immunization procedures enhanced the levels of anti-fimbria IgG, IgA, and IgM in serum, and the major class of fimbria-specific antibody was IgG, followed by IgA and IgM. However, subcutaneous injection was more effective than gastric intubation to enhance the production of serum antibody in mice. The subclasses of IgG antibody specific for fimbriae in serum were mainly IgG1, followed by IgG2a, IgG2b, and IgG3. These results demonstrated that the combined use of B. gingivalis fimbrial antigen and either GM-53 or MDP-Lys(L18) resulted in a sharply increased IgA antibody response in saliva and a predominantly stimulated IgG antibody response in serum, respectively. Both antibodies were found to be specific for the fimbriae used for immunization.

Adjuvants, Immunologic↗
PubMed1989

Cross sectional echocardiographic anatomy of common atrioventricular valve in atrial isomerism.

The morphology of the common atrioventricular valve and its relation to the ventricles was assessed by cross sectional echocardiography in 17 patients with atrial isomerism--four with left isomerism and 13 with right isomerism. In 13 patients the atrioventricular valve consisted of four leaflets: a large anterosuperior leaflet, two lateral leaflets, and a posteroinferior leaflet. The remaining four patients had two anterosuperior leaflets. Five patients had hearts with a double inlet right ventricle and all of them had a rudimentary left ventricle. All the commissures were attached to the right ventricle. Five patients showed severe right ventricular dominance. The atrioventricular morphology in these five hearts differed from that in the patients with the usual atrial arrangement, concordant atrioventricular connection, and hypoplasia of the left ventricle. Only the anterosuperior leaflet bridged the rudimentary left ventricle, and the posteroinferior leaflet was tethered to the ventricular septal crest. Six patients had a biventricular atrioventricular connection and two of them showed mild right ventricular dominance. The atrioventricular morphology in these hearts was the same as that seen in the patients with usual atrial arrangement and a concordant atrioventricular connection. The remaining patient showed dominance of the left ventricle. Only the anterosuperior leaflet bridged the rudimentary right ventricle in this heart.

Adolescent↗
PubMed1989

Primary thyroid lymphoma: comparison of CT and US assessment.

Sixteen patients with primary thyroid lymphoma were studied with computed tomography (CT) and ultrasonography (US), and findings were compared. In 13 of 16 patients, detection of the primary tumor with US and CT were comparable. US was superior in one case, and CT in another. One tumor was not detected with either technique. Thyroid lymphomas appeared as extremely hypoechoic masses intermingled with echogenic structures. Although echogenicity of unaffected thyroid tissue was also low because of coexisting Hashimoto thyroiditis, thyroid lymphomas were relatively well differentiated as markedly hypoechoic areas. Five tumors showed contiguous spread into both thyroid lobes. US and CT were equally sensitive in detection of superficial lymphomatous nodes (seven of 16 cases). CT was superior to US in the definition of tumor extent in two patients with intrathoracic tumor extension and in one with laryngeal invasion. In patients with suspected thyroid lymphoma, CT should be the primary radiologic technique used for diagnosis and staging; US will be useful in local follow-up.

Aged↗
PubMed1989

Study on the constituents of Desmodium styracifolium.

Two triterpenoid saponins (1 and 2) were isolated from Desmodii Herba [the dried whole plants of Desmodium styracifolium (Osbeck) Merr. (Leguminosae)] and their chemical structures were characterized as soyasaponin I and a new saponin, 3-O-[alpha-L-rhamnopyranosyl-(1----2)-beta-D-galactopyranosyl- (1----2)-beta-D-glucuronopyranosyl]soyasapogenol E, respectively, by chemical and spectroscopic means.

Chemical Phenomena↗
PubMed1989

Second genetic polymorphism of tear proteins in the rat (Rtp-2).

Electrophoresis of tear proteins on agarose gel showed polymorphism in the fastest migrating protein among 32 inbred strains of rats. In 8 strains, the protein was missing (RTP-2 B), while the other strains expressed the protein (RTP-2 A). The trait was found to be controlled by a single autosomal locus. The designation Rtp-2 locus, with two alleles (Rtp-2a, Rtp-2b), is tentatively proposed. The Rtp-2 locus is loosely linked to c locus, with a recombination frequency of 36.7 +/- 5.4 percent.

Animals↗
PubMed1989

[Study of trace elements in bovine permanent teeth germ].

It is well documented that uptake of various trace elements take place during tooth development. The purpose of this experiment was to analyze the uptake amount of these various trace elements, in particular Cd, Zn, Pb and Cu throughout the tooth germ formation all the way up to the eruption stage. Bovine permanent tooth germs were used in this experiment. Instead of the conventional morphologic stages, further subdivision into eight groups were employed. The resultant findings were as follows: 1) Uptake of Cd and Zn were verified during the root development to early tooth eruption stage in enamel. Meanwhile, for dentin, the uptake was corroborated from the root development to the late tooth eruption stage. 2) Uptake of Cu was verified during the late tooth eruption stage in enamel. However, no uptake occurred in dentin in any of the various stages. 3) Uptake of Pb occurred during the late tooth eruption stage in enamel. Meanwhile, in dentin, constant equivalent amount of uptake was seen throughout all of the stages. 4) Quantitative analysis of the Cd, Zn and Pb uptake in both enamel and dentin clearly indicated that enamel showed much higher values. The uptake of Cu was found to be significantly high in the groups of the coronal one-third and the eruption four-fifth groups for enamel. Meanwhile, the crown completion group to the half erupted group showed significantly high values for dentin. Based on the above findings, one can deduce clear correlation between enamel organ development and the uptake of the said various trace elements.

Animals↗
PubMed1989

[Caries-inducing activity of isomaltooligosugar (IMOS) in in vitro and rat experiments].

The caries-inducing activity of Isomaltooligosugar (IMOS: a isomaltose rich sugar mixture) was examined in in vitro and in vivo experiments. Strains of Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 fermented IMOS and produced acids. IMOS inhibited the glucan synthesis from sucrose by glucosyltransferases from both of S. mutans and S. sobrinus. Furthermore, IMOS inhibited sucrose-dependent adherence of those mutans streptococci. IMOS was found to induce significant but minimal caries SPF Sprague-Dawley rats infected with either MT8148R and 6715. However, IMOS did not inhibit the caries which was induced by sucrose.

Animals↗
PubMed1989

Bacteroides-specific IgG and IgA subclass antibody-secreting cells isolated from chronically inflamed gingival tissues.

The emergence of cells that produce IgG and IgA subclass antibodies to Bacteroides gingivalis (Porphyromonas gingivalis) fimbriae and lipopolysaccharide (LPS) antigens was examined in mononuclear cells isolated from inflamed gingiva of different stages (slight, moderate or advanced) of adult periodontitis (AP). Antigen-specific IgM, IgG (including IgG1, IgG2, IgG3 and IgG4) and IgA (including IgA1 and IgA2) producing cells were enumerated by the ELISPOT assay and were compared with total Ig-producing cells of each isotype or subclass. In advanced AP, the B. gingivalis fimbriae-specific IgG- and IgA-secreting cells represented 5% of total IgG- or IgA-secreting cells, while those from the moderate stage comprised approximately 1% of these two isotypes. Cells producing antibody specific for B. gingivalis LPS were observed at frequencies of 0.1% and 0.4% for IgG and IgA cells, respectively in the advanced stage. When IgG subclasses were analysed in moderate AP, the anti-fimbriae subclass responses were largely IgG1 (60%), followed by IgG2 (20%), IgG3 (10%) and IgG4 (10%). Fimbriae-specific IgG subclass responses were elevated in the advanced stage of AP, and IgG4 (40%) and IgG1 (30%) were dominant, followed by IgG3 (20%) and IgG2 (10%). IgA1 cells predominated in both the moderate and advanced stages, however a relative increase in IgA2 cells occurred in advanced AP. Mononuclear cells isolated from gingiva of AP patients did not contain cells producing antibody to antigens such as Escherichia coli K235 LPS, cholera toxin or the hapten dinitrophenyl coupled to bovine serum albumin. These results show that local IgG and IgA subclass responses occur to a protein antigen of a major periodontal disease (PD)-associated pathogen, B. gingivalis, and the increase in IgG4 and IgA2 responses may be associated with host protection.

Antibodies, Bacterial↗
PubMed1989

[A case of primary ureteral squamous cell carcinoma associated with calculus].

A case of primary squamous cell carcinoma of the ureter associated with ureteral calculus is presented. A 66-year-old woman was admitted to our hospital, with the chief complaint of macroscopic hematuria in October, 1985. A kidney-ureter-bladder X-ray and drip intravenous pyelography failed to reveal the calculus shadow clearly. However, computerized tomographic scan revealed the calculus shadow clearly adjacent to the ureteral tumor, and retrograde pyelography revealed the filling defect on a third lower portion of the left ureter. She was diagnosed with tumor of the ureter associated with the calculus. She underwent complete nephroureterectomy with excision of a periureteral cuff of the bladder. The tumor was diagnosed histologically as squamous cell carcinoma. Metastases and recurrence of tumor have never occurred on July, 1987. Forty-four cases of the primary ureteral squamous cell carcinoma could be collected in the Japanese literature. Moreover, we deal with this disease associated with the ureteral calculus.

Aged↗