[Computed tomography following endoscopic sclerotherapy of esophageal varices].
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Adult↗
Biomedical subjects
S Hamada
Publications and source records attributed to S Hamada.
Purification and characterisation of the extracellular D-glucosyltransferase from serotype c Streptococcus mutans.
A simple method of purification for the extracellular D-glucosyltransferase (GTase) from a serotype c strain Streptococcus mutans was developed using chromatography on DEAE-Sephacel and CM-cellulose. The GTase had a molecular weight of 155,000 and an isoelectric point of 7.4. The enzyme converted sucrose, in the absence of dextran T-10, into a branched (1----6)-linked alpha-D-glucan having some alpha-(1----3)-linked D-glucosyl residues. The GTase was similar to GTases which have been isolated from other strains of serotype c S. mutans and which synthesise water-soluble glucans. In addition, the amino acid composition of the GTase protein was relatively similar to those of the GTases from serotype g S. mutans which synthesise water-soluble and water-insoluble glucans.
Amino Acids↗
Demonstration and determination of DNA in Pneumocystis carinii by fluorescence microscopy with 4', 6-diamidino-2-phenylindole (DAPI).
We have attempted to demonstrate DNA and to measure the amount of nuclear DNA in Pneumocystis carinii by fluorescence microscopy with 4', 6-diamidino-2-phenylindole (DAPI). Due to the high specificity of DAPI for DNA, only nuclei and mitochondria were stained. An uninucleate trophozoite and a mature cyst containing eight intracystic bodies were distinguished easily each other after staining with DAPI. The total amount of nuclear DNA of eight intracystic bodies in a cyst was approximately eight times that of the small type of trophozoite. When nuclei of uninucleate trophozoites were randomly examined, the distribution pattern of nuclear fluorescence intensity showed two peaks, one at 1C and the other at 2C. Moreover, it showed also a gradual transition in DNA values from 1C to 2C, and very few nuclei with polyploid DNA values. The primary advantage of this method with DAPI is that it allows a more efficient evaluation of the life cycle of P. carinii.
Animals↗
Isolation and mode of action of a cell-free bacteriocin (mutacin) from serotype g Streptococcus mutans MT3791.
A bacteriocin, mutacin MT3791, was isolated from the culture supernatant of a dialysate medium of Tryptose phosphate broth cultures of Streptococcus mutans MT3791 (serotype g), a clinical isolate from a carious lesion of a Japanese child. The mutacin was found to inhibit the growth of most indicator strains of S. mutans and S. salivarius by the drop assay method. The mutacin was purified 1,450 fold from culture supernatant of S. mutans MT3791 by 60% saturated ammonium sulfate precipitation, followed by ultracentrifugation at 300,000 X g for 18 h. Gel filtration studies using Sepharose 4B indicated that the mutacin was highly aggregated, but could be dissociated by addition of 1% (final concentration) Tween 80 or 6M urea. The mutacin was heat stable, but the activity was destroyed after autoclaving at 120 degrees C for 60 min. It was susceptible to the enzymatic action of papain and pronase, but not trypsin, lipase or nucleases. The mutacin was adsorbed to whole cells of most strains of S. mutans. Mutacin MT3791 was bactericidal for an indicator strain, S. mutans MT703R (serotype e). The mutacin inhibited the incorporation of isotope-labelled precursors of protein, DNA, and RNA. Furthermore, mutacin MT3791 selectively and markedly suppressed the growth of S. mutans present in the dental plaque obtained from active carious lesions in the teeth of children. Possible role of mutacin in vivo was discussed with special reference to oral microbial ecology.
Bacteriocins↗
Sucrose-dependent cell adherence and cariogenicity of serotype c Streptococcus mutans.
Four strains of serotype c Streptococcus mutans differing in glucosyltransferase (GTase) and fructosyltransferase (FTase) activities were examined. These strains had been made resistant to streptomycin. FTase activity of an S. mutans clinical variant, MT6801R, which forms large mucoid colonies on sucrose-containing agar, was considerably higher than that of a typical serotype c strain, MT8148R, which forms small, rough colonies on the same agar. Two mutants, NG14 and NG7183, were induced from strain MT6801R by N-methyl-N'-nitro-N-nitrosoguanidine, and were found to be streptomycin-resistant. GTase and FTase activities of mutant NG14 were similar to those of the typical serotype c strain, while in mutant NG7183 the two enzyme activities were very low. Growing cells of these strains (except NG7183) adhered firmly to a glass surface in sucrose broth. Resting cells of all strains attached in small numbers to saliva-coated hydroxyapatite in the absence of sucrose. On the other hand, the presence of sucrose markedly enhanced the attachment of cells of strains MT8148R, MT6801R and NG14, but not NG7183. Cell-surface hydrophobicity and acid production of all strains were similar. Both strain MT8148R and NG14 colonized tooth surfaces and produced significant dental caries in specific-pathogen-free rats. Strain MT6801R had lower colonization ability and cariogenicity when compared with strains MT8148R and NG14. Furthermore, mutant NG7183 was able to colonize the tooth surfaces in small numbers, but failed to cause dental caries. These results indicate that sucrose-dependent cell adherence mediated by de novo glucan synthesis is necessary for the accumulation of serotype c S. mutans cells on the tooth surface and the induction of dental caries.
Adsorption↗
Purification and immunochemical properties of a protein antigen from serotype g Streptococcus mutans.
A proteinaceous antigen (PAg) was purified from the culture supernatant of Streptococcus mutans 6715 (serotype g) by ultrafiltration, ammonium sulfate precipitation, DEAE-Sephacel ion-exchange chromatography, Phenyl-Sepharose CL-4B hydrophobic chromatography, and subsequent Sephacryl S-300 gel filtration. A yield of 0.1 mg of PAg was obtained from a liter of culture supernatant. The isoelectric point and molecular weight of PAg were pH 4.6 and 210,000, respectively. It contained 35% sugar, which was identified as glucose by gas-liquid chromatography. Amino acid analysis revealed that PAg contains 28% acidic and 11% basic amino acid residues. PAg retained its antigenicity after heating at 80 C for 10 min in deionized water, or after treatment with 0.1 M HC1 or 0.1 M NaOH at 37 C for 1 hr. Immunodiffusion and immunoelectrophoresis analyses revealed that PAg is serologically distinct from other cell-surface antigens such as serotype-specific polysaccharide and lipoteichoic acid. A cross-reaction between PAg and a protein antigen similarly prepared from serotype c S. mutans was observed in immunodiffusion tests.
Amino Acids↗
Chemical composition and immunobiological properties of lipopolysaccharide and lipid-associated proteoglycan from Actinobacillus actinomycetemcomitans.
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Actinobacillus↗
Linkage studies on 13 biochemical loci and 2 coat color loci in a [(BN x TM) x TM] backcross progeny of the rat (Rattus norvegicus).
In a [(BN X TM) X TM] backcross progeny of rats, nine significant linkage associations were found among 105 pairwise combinations of 15 loci. After comparing this with other published data and data of personal communications, we considered that the d gene we tentatively designated may be identical to the gene for pink-eyed dilution (p), and that the associations of Gc-Hbb, RT1-h, and Gc-Fh were due to chance rather than real linkage. The linkages obtained in this study, therefore, were Hbb-p (26.5 +/- 5.5) in LG I, Mup-1-Acon-1 (12.5 +/- 4.1) in LG II, Hao-1-Svp-1 (23.8 +/- 6.6) in LG IV, Es-1-Es-3 (17.2 +/- 4.7) in LG V, h-Gc (10.9 +/- 3.3) in LG VI, and Fh-Pep-3 (32.3 +/- 5.9) in LG X.
Alleles↗
DNA ploidy patterns of minute carcinomas in the stomach.
DNA ploidy patterns of minute carcinomas in the stomach were determined by cytofluorometric measurement, using paraffin sections which had been prepared for histological examination. The examples studied were 19 minute carcinomas less than 5 mm in diameter, of which 12 were adenocarcinomas, and 7 were signet ring cell carcinomas. By measuring the fluorescence intensity of more than 30 mitotic nuclei, the DNA ploidy pattern of each tumor was determined. The control diploid DNA content was obtained by measuring the fluorescence intensity of non-cancerous mitoses in the gastric mucosa. In the present study, heteroploidy was seen in 5 carcinomas; 4 adenocarcinomas and one signet ring cell carcinoma. The remaining 14 carcinomas were composed of a diploid stem cell line. In 3 adenocarcinomas, polyploid cells were seen. The occurrence of heteroploidy in the minute cancers was similar to that found in advanced cancers, whereas polyploid cells appeared to occur less frequently in the minute cancers than in the advanced cancers.
Aged↗
[A case of van Buchem's disease with multiple cranial neuropathy].
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Alkaline Phosphatase↗
[Application by unqualified personnel to the seminars for clinical training instructors of Fukuoka Prefecture and the reason for the problem--Report on the Seminars for Clinical Instructors at Fukuoka].
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Clinical Competence↗
[Ehlers-Danlos syndrome--clinico-pathology and orthopedic treatment].
Eight cases of Ehlers-Danlos syndrome (EDS) were surveyed for clinical manifestations and orthopaedic treatment. Cases of EDS were clinically subdivided into three groups. The first group was characterized by multiple congenital contractures in the extremities, so that it was very difficult to distinguish it from arthrogryposis multiplex congenita in early infancy. Since laxity of the soft tissue coexists with contracture in this group, over-correction of deformity caused much more disability than under-correction, especially in clubfoot. Care should therefore be taken to avoid this. The third group was characterized by marked laxity of the soft tissue from birth. Diagnosis in this group was easily made by the obvious triad of EDS. Lengthy immobilization in an appropriate position was necessary to maintain a corrected position for the treatment of any deformity in the hip, foot or hand. In the second group, deformity and disability were clinically so mild that no orthopaedic management was generally required.
Child, Preschool↗
Cell wall preparation consisting of group A carbohydrate and peptidoglycan moieties from Streptococcus pyogenes activates murine B lymphocytes.
Cell walls from Streptococcus pyogenes strain Sv (Group A, M type 3) were lysed with M1 endo-N-acetylmuramidase, and the group A-specific carbohydrate antigen was purified by Sephadex G-100 gel filtration. The initial eluting antigen (M1gA) peak was assessed for mitogenic and polyclonal lymphocyte-activating properties in murine spleen cell cultures. Good mitogenic responses were induced over a broad dose range (1-100 micrograms) with M1gA in both BALB/c and C3H/HeJ splenic cultures. Similar mitogenic responses were induced in nude (nu/nu) and nu/+ splenic cultures, suggesting that M1gA is a B cell mitogen. The M1gA induced anti-trinitrophenyl, anti-sheep erythrocytes, and anti-horse erythrocytes polyclonal plaque-forming cell responses in splenic cell cultures. Studies with purified splenic B cells and M1gA suggest that the mitogenic responses were indeed thymic independent. These studies clearly indicate that native group A carbohydrate antigen is a B cell mitogen and polyclonal B cell activator.
Animals↗
Chemical properties and immunobiological activities of streptococcal lipoteichoic acids.
Lipoteichoic acids (LTAs) were chromatographically purified from crude phenol-water extract of whole cells of some streptococcal species, which included Streptococcus pyogenes Sv, Streptococcus mutans 6715, and Streptococcus sanguis ATCC 10556. Among these, special attention was paid to S. pyogenes LTA for analyses of chemical composition and biological activities. All LTA preparations contained equimolar amounts of glycerol and phosphorus. Chemical analyses showed that S. pyogenes LTA contained glycerophosphate, alanine, glucose, and fatty acids (as palmitic acid) at molar ratio of 1 : 0.1 : 0.1 : 0.25. The crude phenol-water extract and isolated LTA from S. pyogenes Sv were found to be mitogenic for spleen cells of BALB/c and BALB/c (nu/nu) mice, but not for thymus cells of BALB/c mice. The mitogenicity of deacylated LTA (dLTA) was significantly lower than that of LTA. It was also found that various LTA preparations possessed polyclonal B cell activation ability and adjuvant activity both in vivo and in vitro, as demonstrated by using hemolytic plaque assay. LTA, but not dLTA, induced macrophage activation which resulted in tumor cytotoxicity in mice. Limulus lysate activity of S. pyogenes LTA was approximately 1,000 fold lower than that of Escherichia coli lipopolysaccharide. These results indicate that streptococcal LTA possesses various immunobiological activities that modulate lymphoreticular system in vivo and in vitro.
Animals↗
Antigen analyses of serotypes of streptococcus mutans using a monoclonal antibody elaborated against serotype g polysaccharide antigen.
A hybridoma (F4B) which produced a monoclonal antibody (mAb) specific for serotype g carbohydrate antigen (RRg) of Streptococcus mutans 6715 was obtained. The F4B mAb cross-reacted with purified carbohydrate antigens of serotype d (RRd) and serotype h (TCAh). In immunodiffusion tests, F4B mAb produced a stable precipitin band with RRg, while the band developed between the mAb and RRd/TCAh in the cold disappeared when incubated at room temperature. The immunoprecipitin reaction between F4B mAb and RRg was strongly inhibited upon addition of lactose.
Animals↗
DNA content of diffusely infiltrative carcinomas in the stomach.
DNA content of diffusely infiltrative carcinomas of 15 Japanese patients, ranging in age from 38 to 65 years, was determined by cytofluorometry, using paraffin sections which were available for histological examination. Sections were stained with 0.0025% propidium iodide. By measuring the fluorescence intensity of at least 50 mitotic cells, ploidy patterns of the cancers were determined, whereas a control of the diploid DNA content was set by measuring the fluorescence intensity of mitotic cells in the non-cancerous gastric mucosa; only metaphase nuclei in the sections were considered to have a whole amount of nuclear DNA in the cytofluorometric measurement. In the present study, it was found that most of the diffusely infiltrative carcinomas consisted of a heteroploid cell line. Their stem DNA contents ranged between 2.8C and 4.8C (2C corresponds to a diploid amount of nuclear DNA). Of 15 cancers, four comprised a mosaic cancer of two different heteroploid cell lines. We encountered only one carcinoma containing a diploid cell line. However, this cancer also contained a heteroploid cell line. Six cancers contained a polyploid cell population, the DNA content of which was double of the stem DNA content. In most cases, the cancer cells distributed in the mucosal layer were also heteroploid, thereby suggesting a heteroploid origin of the diffusely infiltrative carcinomas.
Adult↗
The use of lipoteichoic acid (LTA) from Streptococcus pyogenes to induce a serum factor causing tumour necrosis.
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Animals↗
Purification and characterization of glucosyltransferases from Streptococcus mutans 6715.
A water-soluble glucan-synthesizing glucosyltransferase (GTase-S) and a water-insoluble glucan-synthesizing glucosyltransferase (GTase-I) were purified from culture supernatant of Streptococcus mutans 6715 (serotype g) by ammonium sulphate precipitation, chromatofocusing on a Polybuffer exchanger PBE 94 column, and subsequent phenyl-Sepharose CL-4B or hydroxyapatite column chromatography. The GTase-S and GTase-I activities were purified 4019- and 4714-fold, respectively, and the molecular weights were calculated to be 160000 and 165000, respectively. GTase-S had a pH optimum of 5.0, a Km of 8.8 mM for sucrose in the presence of 20 microM-dextran T10, and an isoelectric point of pH 4.3. GTase-I had two pH optima of 5.0 and 7.0, Km values of 4.9 mM (at pH 5.0) and 7.0 mM (at pH 7.0), mM (at pH 7.0), and an isoelectric point of pH 4.9. Methylation analysis indicated that the water-soluble glucan produced by GTase-S was a highly branched 1,6-alpha-linked D-glucan with 1,3-linked glucose residues, and that the water-insoluble glucan synthesized by GTase-I was composed of 1,3-alpha-linked glucose units.
Ammonium Sulfate↗