Biomedical subjects

S Sobue

Publications and source records attributed to S Sobue.

At least 73 records · Page 4Linked to original sources

PubMed1989

[Changes of antibody and splenic plaque forming cell responses to mutans streptococci in the rats infected with S. sobrinus 6715].

The study was undertaken to examine the changes in humoral IgM, IgG and IgA antibodies and splenic plaque forming cell responses against Streptococcus sobrinus 6715 in rats infected with the same mutans streptococci. The serum samples were collected every week for 24 weeks after infection (20 day old, Sprague Dawley rats). Humoral anti-S. sobrinus 6715 IgG and IgA antibodies were determined by an enzyme-linked immunosorbent assay. In the separate experiment, rat splenic IgM, IgG and IgA anti-trinitrophenyl (TNP) conjugated S. sobrinus plaque-forming cell (PFC) responses were also determined from 1 to 12 weeks after the infection. The results obtained were as follows: 1. From 1 to 4 weeks after infection, a slight increase in serum IgG anti-S. sobrinus antibody response was observed in the group of rats infected with S. sobrinus 6715 when compared with the non-infected rat group. However, beyond the 5th week, there was no difference in serum antibody responses between these two groups. 2. Infected rats showed a 2-9 times higher serum anti-S. sobrinus IgA antibody response than those of uninfected rats for 6 weeks after the infection. After this period just as with the IgG response, no difference in the IgA titers was found between these two groups. 3. Splenic IgM, IgG and IgA anti-TNP-S. sobrinus PFC responses showed a remarkable decrease shortly after the infection. These results suggest that the infected rats would gradually acquire oral tolerance to S. sobrinus antigen after the infection.

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

[Non-cariogenicity of maltitol in vitro and animal experiments].

The caries inducing activity of maltitol was examined in in vitro and animal experiments. Fifteen strains of oral streptococci were not able to ferment maltitol. Also, maltitol inhibited the glucan synthesis from sucrose by GTases from mutans streptococci. However, the inhibition of growing-cell adherence was not so marked with the addition of maltitol to sucrose culture. In the animal experiments, maltitol did not induced dental caries in rats infected with mutans streptococci. Furthermore, maltitol significantly inhibited the sucrose-induced dental caries in rats infected with S. sobrinus 6715. However, there was no significant difference in rats infected with S. mutans MT8148R. These results indicated that maltitol is useful as a non-cariogenic sucrose substitute.

Animals↗

PubMed1989

[Clinical survey of caries incidence in children with cleft lip and palate].

The caries incidence was clinically examined in 119 children with cleft lip and palate (CLP; 65 male and 54 female; 2 to 14 years of age). At the lower age, the CLP children had more dental caries in the upper teeth than normal children, and, the caries prevalence became higher, with the increase in the age. In both primary and permanent dentitions, the CLP children showed an extremely high caries incidence in the upper anterior teeth, which was related to the presence of cleft. The characteristic oral structures of CLP patients; such as abnormalities of tooth position and axis, the presence of scars, and the absence of vestibular oris, increased the area on the tooth surfaces which afforded the protection from the self-cleaning activity in the mouth, and consequently induced high caries prevalence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

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