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Biomedical subjects

T Ooshima

Publications and source records attributed to T Ooshima.

At least 91 records · Page 5Linked to original sources
PubMed1988

Structural deformities of deciduous teeth in patients with hypophosphatemic vitamin D-resistant rickets.

Structural deformities of deciduous teeth from patients with hypophosphatemic vitamin D-resistant rickets (HVDRR) (1 male and 2 female patients) were examined by means of transmitted light microscopy, contact microradiography, and x-ray microanalysis. Freshly extracted teeth were fixed in formalin and subsequently hemisected longitudinally through the midline. One half was prepared for ground sections and the other half for decalcified sections. Neither gross nor microscopic abnormalities were present in enamel of patients with HVDRR. The concentration of calcium and phosphorus and the calcium/phosphorus ratio of the enamel of patients with HVDRR were nearly equal to those of normal teeth, although the degree of radiopacity was less in HVDRR. On the other hand, numerous microscopic abnormalities in the dentin of patients with HVDRR were found, such as interglobular dentin, wide predentin zones, and tubular defects. The concentration of phosphorus in the dentin of a patient with familial HVDRR was extremely low. Furthermore, formation of reparative dentin was observed at the pulp horn of teeth in patients with HVDRR that had been subjected to definite attrition at the corresponding dentin site.

Calcium↗
PubMed1988

Maternal transmission and dental caries induction in Sprague-Dawley rats infected with Streptococcus mutans.

Thirty-four female rats (18 days old) were infected with Streptococcus mutans MT8148R (serotype c) or 6715 (g). Diets containing different proportions of sucrose were used to prepare the dams which harbored various levels of S. mutans in their oral cavity. Around 66 days of age, the female rats were bred and 34 dams subsequently bore 322 offspring. The dams were killed upon weaning (20 days of age) of their respective litters. There were positive correlations between the recovery of inoculated S. mutans and the caries incidence in the dams. Transmission of S. mutans from a dam to her offspring was studied in 10-, 15-, 20-, 27-, 34-, 41-, 48-, and 55-day-old rats by evaluating the recover of S. mutans from the offspring. Positive correlation between the magnitudes of recovered S. mutans MT8148R from dams and their offspring was found in all ages of young rats examined. Furthermore, caries incidence in young rats was found to be positively correlated with the recovery of both strains of S. mutans as well as with incidence of caries in their respective dams.

Animals↗
PubMed1988

The caries inhibitory effects of GOS-sugar in vitro and in rat experiments.

The caries inhibitory activity of GOS-sugar (panose- and maltose-rich sugar mixture) was examined and compared with that of sucrose, maltose, or glucose in in vitro and in vivo experiments. Streptococcus mutans MT8148R (serotype c) and Streptococcus sobrinus 6715 (g) did ferment GOS-sugar and produce acid in a similar way as with maltose and glucose. However, GOS-sugar could not be a substrate for the glucosyltransferases (GTases) of these mutans streptococci to synthesize the water-insoluble glucan. Also, it significantly inhibited not only the synthesis of water-insoluble glucan from sucrose by the crude GTases but also the sucrose-dependent adherence of these cells to a glass surface. In particular, adherence of growing cells of 6715 was markedly inhibited by the presence of GOS-sugar. GOS-sugar was found to induce significant but minimal dental caries in SPF rats infected with either MT8148R or 6715. Furthermore, the replacement of half of the dietary sucrose content with GOS-sugar resulted in a significant reduction of caries development in rats infected with strain 6715.

Animals↗
PubMed1988

Effect of inoculum size and frequency on the establishment of Streptococcus mutans in the oral cavities of experimental animals.

SPF Sprague-Dawley rats and ICR mice were inoculated with either Streptococcus mutans MT8148R (serotype c) or 6715 (g), and the influence of inoculum size, inoculum frequency, and sucrose on the establishment of S. mutans in the oral cavity was examined. Successful colonization of S. mutans in the experimental animals was absolutely dependent on the number of the cells introduced orally. Furthermore, inoculum frequency and sucrose seemed to act as secondary factors to modify the establishment of S. mutans, and it is suggested that high inoculum frequency may decrease the inoculum size necessary for the colonization of S. mutans in the oral cavity.

Animals↗
PubMed1988

[A case of ovarian granulosa cell tumor with invasive adenocarcinoma of the endometrium].

A case of an ovarian granulosa cell tumor with an invasive adenocarcinoma of the endometrium, and a review of the relevant Japanese literature is reported. A 47-year-old woman was admitted to Ichinomiya Citizens' Hospital complaining of irregular uterine bleeding. On operating, an ovarian tumor was found with a broad-based polypoid mass extending into the endometrium. These lesions were histologically diagnosed as a granulosa cell tumor with an invasive adenocarcinoma of the endometrium. We have found 4 cases of a granulosa cell tumor with adenocarcinoma of the endometrium in the Japanese literature and have determined that our case with an endometrial cancer showing an invasion to the myometrium of the uterus is unique among previously reported cases.

Adenocarcinoma↗
PubMed1987

[Studies on glucose challenge test (GCT) as a screening procedure for gestational diabetes mellitus].

A glucose challenge test (GCT) was developed as a screening procedure for the diagnosis of gestational diabetes mellitus (GDM). The method includes a 50gm oral glucose load and measurement of the plasma glucose concentration once at one hour after ingestion. The data were examined in 1,184 pregnant women seen at the outpatient clinic of our department from May 1984 to December 1986. Prior to the present study, 722 pregnant women were given a 75gm glucose tolerance test (75gGTT) and plasma glucose and IRI values were also analyzed. 1) Because glucose tolerance evaluated by the GCT was revealed to be impaired around the 28th week of pregnancy, it seems appropriate that screening for GDM should be planned during this period whenever possible. 2) The mean values obtained with GCTs performed before and after 28 weeks were 119 +/- 25mg/dl and 128 +/- 25mg/dl, respectively. 3) When the one-hour plasma glucose levels were compared after one 50 and one 75gm glucose load at intervals of less than 2 weeks, there was reproducibility in individual women with normal glucose tolerance, while the results were consistent in patients with DM or GDM. A mean difference of 18mg/dl at one hour was shown between the different glucose loads. 4) When screening for GDM was attempted in pregnant women with the 75gGTT, sensitivity and specificity were highest in the plasma glucose level at the one hour point. 5) GDM was found in the group of patients with plasma glucose levels of 155mg/dl or higher determined by GCT; the incidence was high in patients with plasma glucose levels of 160mg/dl or higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

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↗
PubMed1985

Actinomyces viscosus cell-free synthesis of extracellular slime polysaccharide.

A cell-free extract of Actinomyces viscosus T14Av catalyzed the synthesis of extracellular N-acetylglucosamine-rich slime polysaccharide. The activity was localized in the cytoplasmic membrane fraction and required the presence of ADP-glucose and UDP-N-acetylglucosamine. Maximal activity was demonstrated at pH 7.5 and also required the presence of divalent cations such as Mg2+ or Mn2+. Extracellular slime appeared to serve as a primer for slime biosynthesis. The antibiotic tunicamycin acted as an inhibitor of slime formation. However, another glucosamine analogue, amphomycin, as well as the antibiotic bacitracin produced moderate stimulatory effects on slime biosynthesis.

Actinomyces↗
PubMed1985

Effect of mutacin administration on Streptococcus mutans-induced dental caries in rats.

A bacteriocin from serotype c Streptococcus mutans strain C3603 was examined for its inhibitory effect on experimental dental caries in rats infected with S. mutans MT8148R (serotype c). Significant reduction in the incidence of dental caries was found only when bacteriocin was incorporated both in the drinking water and in the diet at a high concentration. However, caries reduction was not as great as expected and the addition of bacteriocin to drinking water alone had no effect on the recovery of S. mutans, plaque deposition or caries incidence. The bacteriocin activity must have been reduced in the oral cavity of rats, and the reasons were examined. Bacteriocin-resistant mutants were not detected and the bacteriocin was not inactivated by saliva. Whereas the bacteriocin did not kill the S. mutans cells grown in a sucrose-containing medium, it completely killed the cells grown in a sucrose-free medium.

Animals↗
PubMed1985

Relationships between red cell cation contents and blood pressure level.

Red cell sodium (R-Na), potassium (R-K) and sodium to potassium ratio (R-Na/K) were studied in 2,542 adults participating in periodic medical examinations. The mean values of R-Na and R-Na/K in untreated borderline (n = 406) and definite hypertensives (n = 485) were higher than those in normotensives (n = 1,651), but that of R-K was not different among the groups. The increased R-Na and R-Na/K in the hypertensives were observed only in those under 50 years, but not in those 50 years and over. In the normotensive subjects, age and sex affected the intraerythrocyte cation contents, but a positive family history of hypertension did not. Although a few characteristics correlated with both R-Na and mean blood pressure, and with both R-Na/K and mean blood pressure, multiple regression analyses revealed that R-Na and R-Na/K independently and significantly contributed to the variation in mean blood pressure. It was also indicated that these relations of R-Na and R-Na/K to mean blood pressure were significant in those under 50 years, but not in those 50 years and over. While several characteristics confound the relationships between red cell cation contents and blood pressure, these results suggest that the contributions of R-Na and R-Na/K to the mechanisms of human hypertension still persist in young to middle-aged people.

Adult↗