Search PubMed⌕ Search

Biomedical subjects

J Mizuno

Publications and source records attributed to J Mizuno.

At least 73 records · Page 4Linked to original sources
PubMed1988

Isolation and physiological characterization of Streptococcus milleri strains from human dental plaque.

Of 271 Gram-positive, catalase-negative, chain-forming cocci isolated from crevicular and supragingival plaques of 22 adults, 71 stains were clustered as Streptococcus milleri by testing 23 physiological characters. Most of the oral S. milleri strains were nonhaemolytic and formed minute smooth colonies on glucose and sucrose agar plates, while some of the clinical strains were alpha-haemolytic, forming rough colonies on Carlsson's MC agar plate as well as carrying the Lancefield group antigens C, F or G. The strains were divided into two biotypes, and further into six subtypes by their abilities to ferment maltose, salicin and/or lactose. Distribution of the varieties according to the haemolytic, colonial and serological properties among the oral isolates generally corresponded to the tentative biological types of S. milleri.

Adult↗
PubMed1987

Pituitary tumors composed of adenohypophysial adenoma and Rathke's cleft cyst elements: a clinicopathological study.

Nine cases of pituitary tumors composed of mixed tissue elements of adenohypophysial adenoma and Rathke's cleft cyst are reported. All cases were associated with hyperprolactinemia and were managed by transsphenoidal adenomectomy with good results. The clinical and pathological features are presented, and embryological pathogenesis for the occurrence of this unique association is discussed in connection with the high incidence of immunoreactive S-100 protein cells identified in tumor tissues. Patients with this kind of pituitary tumor can be managed in the same fashion as patients with other types of pituitary adenoma.

Adenoma↗
PubMed1987

Ganglioglioma of the cerebellum: case report.

The authors report a rare case of a cerebellar ganglioglioma. A review of 12 previously reported cases and our case suggest that surgical removal of this neoplasm carries a good prognosis.

Adult↗
PubMed1987

Isolated histiocytosis X of the pituitary gland: case report.

The authors describe a case of a granuloma of histiocytosis X localized in the pituitary gland. The patient presented with diabetes insipidus and hyperprolactinemia. The diagnosis was established by surgical removal of the pituitary lesion through a transsphenoidal approach. The clinical and pathological aspects of the case are discussed.

Adult↗
PubMed1986

Personal computer-controlled microsurgery of fertilized eggs and early embryos.

The microsurgery of mouse and rat eggs and early embryos was attempted using a micromanipulator driven by three pulse motors. The pulse signals that regulate the three pulse motors for the X, Y, and Z axes were controlled according to the personal computer programs produced on the basis of the displayed data. As a result, the following was found. 1) The computer-controlled operation was possible in the X and Y plane on a specimen previously suctioned and retained by a holding pipet. A microinjection pipet was inserted into the male pronucleus of a fertilized egg and the morula was bisected using a microblade; these microtools were moved horizontally. 2) A more complicated micromanipulation in two dimensions (X and Z axes), which is very difficult manually, was possible by using this system. 3) microsurgery (microinjection of a fluorescent material (FITC) into the male pronucleus, enucleation of a fertilized egg, and vertical or horizontal bisection of morulae) was carried out successfully by a student who had no practical experience in this field. These facts suggest that the system markedly facilitates microsurgery, without need for full training in the manual procedures.

Journal Article↗
PubMed1986

[Postoperative spinal cord herniation diagnosed by metrizamide CT: a case report].

A 55-year-old man came to our hospital, complaining of progressive deterioration of gait disturbance 13 years following C4-7 laminectomy. Neurological examination showed marked spastic gait, hyperreflexia in the lower limbs, ankle clonus, hypesthesia below C5, and loss of position and vibratory sensations in great toes. Preoperative metrizamide CT clearly demonstrated pseudomeningocele and cervical cord herniation through the dural defect at C6-7 and narrow canal at C3. Moreover, sagittal and coronal reconstructions reveal a clear-cut posterior displacement of the cervical cord with posterior protrusion of the cord through the possible dural defect and the obvious extent of pseudomeningocele. At the operation, herniation of the posterior aspect of the cord through the dural defect at C6-7 was encountered as well as pseudomeningocele from the leakage at the C5 level. The cause of spinal cord herniation is classified into i) congenital, ii) traumatic, iii) iatrogenic. An iatrogenic spinal cord herniation is rare and its preoperative diagnosis used to be hard. Discussion was made on the points of preoperative diagnosis of a postoperative spinal cord herniation by metrizamide CT.

Hernia↗
PubMed1985

Chemical and immunological characterization of a novel amphipathic antigen from biotype B Streptococcus sanguis.

A new type of amphipathic antigen was extracted from whole cells of Streptococcus sanguis ATCC 10557 (biotype B, serotype II) by the phenol/water method. The extract was treated with nuclease P1, and was applied to a column of Sepharose 6B. Each fraction was checked by passive haemagglutination (PHA) and immunodiffusion tests against anti-10557 serum which was obtained by immunizing rabbits with whole cells of strain ATCC 10557. Strong PHA activity was demonstrated in the first hexose-containing peak (peak 1) eluted near the void volume, while the second hexose-containing peak (peak 2) produced a heavy band against anti-10557 serum in an immunodiffusion test. The third peak (peak 3) which partially overlapped with peak 2 reacted with concanavalin A, but not with the antiserum, in agar gel. Peaks 2 and 3 had no PHA activity. Peak 1 contained only 1% phosphorus, indicating that cells of strain ATCC 10557 possess an amphipathic antigen which differs from the lipoteichoic acids that are common in many Gram-positive bacteria. Peak 1 was a fatty acid-substituted heteropolysaccharide composed of glucose, galactose, mannose, glycerol and fatty acids in a molar ratio of approximately 1.0:1.3:2.7:0.3:1.0. PHA activity was inhibited in the presence of polymerized mannose. Peak 2 was composed of glucose, galactose, rhamnose and N-acetylgalactosamine in a molar ratio of approximately 1.0:1.4:0.8:0.8, which was essentially identical to the serotype II carbohydrate antigen reported previously.

Antigens, Bacterial↗
PubMed1985

[Threshold of penicillin induced epileptiform afterdischarge in brain slices of guinea pig].

Investigation of the regional threshold for epilepsy in many structures in the brain would contribute to the study of epileptogenesis. So we studied the threshold for epileptiform afterdischarge in the neocortex, hippocampus and cerebellar cortex using Na-Penicillin -G (Pc) of which epileptogenesis has been intensively investigated. In order to eliminate the influence from the outside of these structures, the brain slice method was utilized. Procedures for preparation of the tissue and incubation were about the same as those described by Yamamoto. In summary, after sacrifice, brain of the guinea pig was taken out and the hippocampus, neocortex and cerebellum were cut with a razor blade under a microscope. The thickness of the section was about 0.3 mm. Slices were incubated at 37 degrees C for about 30 min in the standard medium perfused with 95% O2 and 0% CO2. The chamber was continuously perfused with the standard medium which composed of NaCl, 124 mM, KCl, 5: KH2PO4, 1.24; MgSO4, 1.3; CaCl2, 2.4; NaHCO3, 26; and glucose, 10. Evoked potentials were elicited by electrical stimulation in the standard medium. Mossy fibers were stimulated and responses were recorded from the CA3 area in the hippocampus by glass pipette microelectrode. Subcortical white matter was stimulated and responses were recorded from the Purkinje cell layer in the cerebellum. Pc was added in the standard medium until epileptiform afterdischarges were superimposed on the evoked potentials. The results of this experiment demonstrated that each structure in the brain has a regional own threshold for Pc induced epileptiform afterdischarge.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

A factor from Actinomyces viscosus T14V that specifically aggregates Streptococcus sanguis H1.

A highly specific aggregation factor for Streptococcus sanguis H1 (AFH1) was obtained by lysozyme treatment of Actinomyces viscosus T14V. At 1 micrograms/ml, AFH1 aggregated a suspension of S. sanguis H1, with which A. viscosus T14V coaggregates by a mechanism not inhibited by lactose: even at much higher levels AFH1 caused little or no aggregation of streptococci from other coaggregation groups (J. O. Cisar et al., Infect. Immun. 24:742-752, 1979). The most active fraction of AFH1 obtained by gel chromatography (near the void volume of Bio-Gel A1.5 m) reacted as a single antigen with anti-A. viscosus T14V serum and was unrelated to the fimbrial antigens of A. viscosus T14V. Smaller molecular fractions, at high levels, inhibited aggregation of S. sanguis H1 by high-molecular-weight AFH1 as well as coaggregation of S. sanguis H1 with A. viscosus T14V. The AFH1 fraction with high aggregating activity was composed of approximately 53% cell wall components (alanine, glutamine, lysine, N-acetylglucosamine, and N-acetylmuramic acid). 40% polysaccharide (N-acetylgalactosamine, rhamnose, and 6-deoxytalose), and 7% protein; teichoic acid was not detected. The fraction which inhibited aggregation and coaggregation contained much less of the cell wall constituents and more of the polysaccharide than the fraction with potent aggregating activity. Aggregation was completely prevented either by treating AFH1 with 0.01 M periodate at 25 degrees C for 4 h or by treating S. sanguis H1 with heat or pronase. A role for electrostatic forces in the aggregation was indicated by: (i) NaCl inhibition of aggregation, and (ii) a great decrease in aggregation potency as a result of chemical modification of either cationic or anionic groups of AFH1. On the other hand, NaCl reversed the aggregation only very weakly. The overall data suggest that a carbohydrate-protein interaction may be dominant in the aggregation of S. sanguis H1 by AFH1 and in the coaggregation of S. sanguis H1 with A. viscosus T14V.

Acetylgalactosamine↗
PubMed1983

Purification and immunochemical characterization of Streptococcus sanguis ATCC 10557 serotype II carbohydrate antigen.

Cell wall carbohydrate antigen of Streptococcus sanguis ATCC 10557 (serotype II/biotype B) was extracted from purified cell walls by treatment with 5% trichloroacetic acid at 4 degrees C for 8 h. The extract was purified by chromatography on DEAE-Sephadex A-25 and Sephadex G-100 columns. The purified carbohydrate antigen produced a single precipitin band against anti-type II serum, which fused with the band produced by the autoclaved extract or the phenol-water extract of the S. sanguis cells. The type II antigen was a polysaccharide composed of glucose, galactose, rhamnose, and N-acetylgalactosamine in a molar ratio of approximately 3:6:3:2. Quantitative precipitin inhibition tests with various haptenic sugars indicated that N-acetylgalactosamine was a major determinant of the type II antigen.

Amino Acids↗
PubMed1979

Serological properties of cellular and extracellular glycerol teichoic acid antigens of Streptococcus mutans.

Cell-free supernatant of Streptococcus mutans cultures was concentrated by 50% ammonium sulphate precipitation to 1/50 of the original culture volume. Most extracellular glucosyltransferase activity was detected in the supernatant. Furthermore, the supernatant reacted with serotype specific antiserum, showing immunological identities with the serotype specific polysaccharide antigen obtained from whole cells by hot saline or NaOH extraction in double diffusion tests. Immunoelectrophoretic analysis also revealed that the supernatant antigen possessed significant quantities of lipid-bound and free glycerol teichoic acid antigens. The lipoteichoic acid (LTA) was obtained from whole cells by phenol-water extraction. The lipid-teichoic acid linkage was easily split by mild acid or alkaline hydrolysis. The supernatant and phenol antigens spontaneously sensitized sheep red blood cells. These antigens were adsorbed to hydroxyapatite powder. The extracellular LTA and glucosyltransferase were found to be closely associated and difficult to separate chromatographically. In vivo significance of these properties of LTA and GTase is discussed in terms of the ecology of S. mutans and other oral streptococci.

Antigens, Bacterial↗
PubMed1978

A separation of staphylococci and micrococci based on serological reactivity with antiserum specific for polyglycerophosphate.

A serological reaction with the antiserum against heterophile polyglycerophosphate (PGP) was evaluated for genus level differentiation among strains of Staphylococcus and Micrococcus-Sarcina spp.. Hot saline extracts from whole cells of Staphylococcus spp. strongly reacted with the PGP antiserum, whereas those of Micrococcus-Sarcina spp. did not. Likewise, phenol-water extracts from whole cells of Micrococcus-Sarcina spp. were not reactive with the PGP antiserum, although the extracts of staphylococcal cells again gave a strong reaction with the antiserum. This study indicates that extracts from Micrococcus-Sarcina spp. have no antigen reactive with the PGP antiserum and can thus be differentiated from extracts of Staphylococcus spp. which react strongly with the PGP antiserum.

Antibodies, Bacterial↗
PubMed1977

Clostridium perfringens--specific lysin.

A mitomycin C induced lysate of Clostridium perfringens strain KZ219 was lytic to 50 strains of C. perfringens of types A-E, and three strains of C. plagarum. The lysin was active against only 2 out of 87 strains of 51 other clostridial species. The optimum pH of the lytic agent was 5.5. The activity was largely inactivated by proteolytic enzymes, and nearly completely inactivated by heating at 60 degrees C for 5 min.

Bacteriocins↗
PubMed1976

Inhibition of rat dental caries by dextranase from a strain of Spicaria violacea.

Dextranase AD17 obtained from a culture liquor of a strain of Spicaria violacea was assessed for its ability to inhibit the development of dental caries in conventional Sprague-Dawley rats which had been infected with one of the Streptococcus mutans strains. MT6R (serotype c), OMZ 176R (d), or MT-703R (e). These experiments showed that caries was significantly inhibited when rats were given cariogenic diets No. 2000 and drinking water containing AD17 at a concentration of 10 units/g, as compared to control rats not given dextranase. The inhibitory effects of AD17 were more prominent in smooth surface caries than in total caries. AD17 had a tendency to retard both the establishment of inoculated S. mutans and plaque deposition on tooth surfaces. However, S. mutans could be implanted in the rat oral cavity after repeated inoculation of the bacteria, even in the presence of AD17. These results suggest that the anticaries activity of AD17 is due to not only inhibition of adherence of S. mutans cells on tooth surfaces but also to physiochemical changes of dental plaque formed under the enzymatic action of AD17. Preliminary histophatological examination showed that AD17 had no significant toxicity in rats.

Animals↗
PubMed1975

Effect of dextranase on the extracellular polysaccharide synthesis of Streptococcus mutans; chemical and scanning electron microscopy studies.

A dextranase preparation (AD17) partially purified from a culture liquor of Spicaria violacea strain IFO 6120 significantly inhibited the formation of artifcial dental plaque on a steel wire or on an extracted tooth surface. Changes in the surface morphology of Streptococcus mutans cells due to AD17 action were studied using scanning electron microscopy. S. mutans cells grown in 5% sucrose-containing broth were coated with sticky amorphous capsule-like material, whereas cells grown in sucrose in the presence of AD17 or in glucose instead of sucrose did not synthesize such capsular material. AK17 degraded commercially available dextrans of molecular weight 7 X 1(04) and 2 X 10(6) to liberate glucose and various oligosaccharides, including isomaltose. On the other hand, AD17 hydrolyzed the extracellular polysaccharides (mainly glucan in nature) of some strains of S. mutans to a limited degree. Only 15 to 36% of the total polysaccharides were hydrolyzed by AD1M with little release of isomaltose. Prolonged incubation of the polysaccharides from S. mutans with AD17 did not release additional reducing sugars, which indicates that AD17 did not contain alpha-1,3-glucanase activity. These results suggest that glucosidic linkages which are susceptible to AD17 may play an important role in the adherence of S. mutans cells to smooth surfaces.

Dental Plaque↗