Biomedical subjects

T Ooshima

Publications and source records attributed to T Ooshima.

At least 37 records · Page 2Linked to original sources

PubMed2000

Cloning and characterization of the human ameloblastin gene.

We isolated the full-length human ameloblastin (AMBN) cDNA clone using reverse transcription-polymerase chain reaction (RT-PCR) methods. Sequence analysis of the AMBN cDNA revealed an open reading frame of 1341bp encoding a 447-amino-acid protein. Comparison with pig, cattle, rat, and mouse AMBN sequences showed a high amino acid sequence similarity and led to the identification of a novel 78bp (26 amino acids) insert resulting from internal sequence duplication. By DNA analysis of a human genomic clones, the AMBN gene was shown to consist of 13 exons and a novel 78bp segment, which proved to comprise two small exons. Human ameloblastomas express AMBN transcripts that contain some mutations.

Ameloblastoma↗

PubMed2000

Calbindin D28k-like immunoreactivity during the formation of the enamel-free area in the rat molar teeth.

Previous studies have demonstrated the presence of calbindin D28k in the ameloblasts derived from the inner enamel epithelium. The occlusal surfaces of the rodent molars partly lack the enamel covering, which is referred to as enamel-free area (EFA). In the present study, we compared the immunohistochemical localization of calbindin D28k-like immunoreactivity (CB-LI) in the cells at the EFA (EFA cells) and ameloblasts of the rat molar teeth at the light microscopic level. CB-LI was strong in the ameloblasts of the presecretory through the protective stages, while it was faint at the late secretory to transitional stages. However, some mature ameloblasts lacked the immunoreactivity. On the other hand, the majority of EFA cells showed distinct polarization and elongation that were absent in few cells at the early stage of EFA formation. At all stages, the EFA cells adjacent to the ameloblasts showed CB-LI, however, some cells adjacent to the mature ameloblasts lacked the reaction. Intensive CB-LI was demonstrated in EFA cells at the reduced enamel epithelium. These immunohistochemical findings suggest EFA cells have cytochemical properties similar to those of ameloblasts.

Ameloblasts↗

PubMed2000

Caries inhibitory activity of cacao bean husk extract in in-vitro and animal experiments.

Cacao bean husk extract (CBH) was examined for inhibitory effects on the caries-inducing properties of mutans streptococci in vitro and on caries development in specific pathogen-free Sprague-Dawley rats infected with mutans streptococci. CBH reduced the growth rate of almost all oral streptococci examined, which resulted in the reduction of acid production. Furthermore, insoluble glucan synthesis by the glucosyltransferases from Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 was significantly inhibited by CBH. Hence, the sucrose-dependent cell adherence of mutans streptococci was also depressed by CBH. The administration of CBH in drinking water resulted in significant reductions of caries development and dental plaque accumulation in rats infected with either Strep. sobrinus 6715 or Strep. mutans MT8148R, and the minimum cariostatic concentration was 1.0 mg/ml. These results indicate that CBH possesses powerful anticariogenic potential.

Analysis of Variance↗

PubMed2000

Cariostatic activity of cacao mass extract.

Chocolate is suspected to contain some caries-inhibitory substances. The cariostatic activity of cacao mass extract (CM), the main component of chocolate, was examined in vitro and in experimental animals. CM showed no detectable effects on the cellular growth and acid production of mutans streptococci. On the other hand, the cell-surface hydrophobicity of mutans streptococci was significantly reduced by the presence of CM. Furthermore, insoluble glucan synthesis by the glucosyltransferases from either Streptococcus mutans MT8148R or Strep. sobrinus 6715 was inhibited by CM, but not significantly. Hence, the sucrose-dependent cell adherence of mutans streptococci was also depressed by CM. Finally, CM in both a 40% sucrose diet and drinking water resulted in reductions of caries development and plaque accumulation in rats infected with Strep. sobrinus 6715, but not significantly. These results indicate that cacao mass extract possesses some anticariogenic potential, but its anticaries activity is not strong enough to suppress significantly the cariogenic activity of sucrose.

Animals↗

PubMed2000

Tooth eruption in a patient with craniometaphyseal dysplasia: case report.

Craniometaphyseal dysplasia (CMD) is a very rare genetic disorder of bone remodeling caused by osteoclast dysfunction. The clinical and radiographical features of oral findings are presented in a sporadic case of CMD in a child (age 10 years, 7 months). An intraoral examination showed severe malocclusions, including anterior crossbite and deep bite. Furthermore, a radiographic examination showed increased radiopacity of the maxilla and mandibular bones due to hyperostosis and sclerosis of the jaw. There was no root resorption of the canines or molars in the primary dentition, although root formation of the permanent teeth was proceeding. Dental age was calculated to be approximately 1 year, 4 months younger than his chronological age. The eruption speed of the permanent lateral incisors after the gingival emergence was shown to be within normal values, and we discuss whether the canines and premolars in the permanent dentition could erupt or not.

Child↗

PubMed2000

Altered expression level of calbindin D28k in the periodontal ligament of rat molar in response to changes in occlusal force.

The present immunohistochemical study was designed to investigate the alteration in the expression level of calbindin D28k in the periodontal ligament of the rat molar in response to changes in occlusal force to clarify the physiological role(s) of this protein in the ligament. In normal periodontal ligament of the lower first molar, immunoreactivity for calbindin D28k was found in the spindle-shaped cells, presumably fibroblasts, at the alveolar portion of the ligament at the distal side of the mesial root and mesial side of the distal root. Following the overload of occlusal force to the upper first molar by bite-raising, the number and immunoreactivity of the positive cells in the periodontal ligament of the lower first molar increased gradually. A more significant increase was detected at 7 d following the bite-raising compared to the normal animals. When occlusal force was removed by the extraction of the upper first molar, the expression level of calbindin D28k in the periodontal ligament of the lower first molar rapidly decreased, however a subsequent gradual increase was recognized. Statistical analysis of the spatial immunoreactivity of calbindin D28k in the periodontal ligament was performed and showed statistically significant differences. The present results suggest that calbindin D28k may play important roles in the homeostasis and cytoprotection of the periodontal fibroblasts against occlusal force.

Analysis of Variance↗

PubMed2000

Multiple fractures of primary molars caused by injuries to the chin: report of two cases.

Two cases of multiple fractures of the primary molars caused by injuries to the chin are presented. Clinical and radiographic examinations revealed a vertical fracture line in the maxillary and mandibular primary molars. Pulpotomy or pulpectomy treatment was performed on the affected teeth, which were then restored with preformed stainless steel crowns.

Accidental Falls↗

PubMed2000

Crown dilaceration of a first premolar caused by extraction of its deciduous predecessor: a case report.

This report describes a rare case of crown dilaceration of the mandibular first premolar caused by trauma during extraction of the precedent primary first molar. The mandibular first primary molar had been extracted at the age of 4 years 7 months. Compared to the pre-operative radiograph, the post-operative film showed that the direction of the first premolar tooth germ had changed, suggesting that crown dilaceration had been induced by the surgical procedures during tooth extraction. From radiographic examinations, the premolar was considered to have erupted spontaneously.

Bicuspid↗

PubMed2000

Expanded polyglutamine stretches interact with TAFII130, interfering with CREB-dependent transcription.

At least eight inherited neurodegenerative diseases are caused by expanded CAG repeats encoding polyglutamine (polyQ) stretches. Although cytotoxicities of expanded polyQ stretches are implicated, the molecular mechanisms of neurodegeneration remain unclear. We found that expanded polyQ stretches preferentially bind to TAFII130, a coactivator involved in cAMP-responsive element binding protein (CREB)-dependent transcriptional activation, and strongly suppress CREB-dependent transcriptional activation. The suppression of CREB-dependent transcription and the cell death induced by polyQ stretches were restored by the co-expression of TAFII130. Our results indicate that interference of transcription by the binding of TAFII130 with expanded polyQ stretches is involved in the pathogenetic mechanisms underlying neurodegeneration.

Aged↗

PubMed2000

Simultaneous occurrence of unusual odontodysplasia and oligodontia in the permanent dentition: report of a case.

Odontodysplasia is an uncommon clinicopathological condition with a variety of expressions. Although it is generally recognized as a localized disorder of dental tissue, its aetiology has not yet been well explained. In the present case, odontodysplasia with oligodontia in the permanent dentition is reported. The patient was in good health with normal stature and no other physical abnormalities. His parents and siblings were dentally and medically normal. The primary teeth appeared to be normal except for the primary second molars, where the enamel was malformed. However, the permanent incisors that had erupted into the oral cavity showed rough and hypoplastic enamel. An orthopantomogram showed 17 congenitally missing permanent teeth and malformation of the other 11 permanent teeth and tooth-germs. Because these findings were caused by developmental disturbances of both the mesodermal and ectodermal dental components, we diagnosed the present case as odontodysplasia accompanied by oligodontia in the permanent dentition.

Anodontia↗

PubMed2000

Purification, characterization, and molecular analysis of the gene encoding glucosyltransferase from Streptococcus oralis.

Streptococcus oralis is a member of the oral streptococcal family and an early-colonizing microorganism in the oral cavity of humans. S. oralis is known to produce glucosyltransferase (GTase), which synthesizes glucans from sucrose. The enzyme was purified chromatographically from a culture supernatant of S. oralis ATCC 10557. The purified enzyme, GTase-R, had a molecular mass of 173 kDa and a pI of 6.3. This enzyme mainly synthesized water-soluble glucans with no primer dependency. The addition of GTase markedly enhanced the sucrose-dependent resting cell adhesion of Streptococcus mutans at a level similar to that found in growing cells of S. mutans. The antibody against GTase-R inhibited the glucan-synthesizing activities of Streptococcus gordonii and Streptococcus sanguis, as well as S. oralis. The N-terminal amino acid sequence of GTase-R exhibited no similarities to known GTase sequences of oral streptococci. Using degenerate PCR primers, an 8.1-kb DNA fragment, carrying the gene (gtfR) coding for GTase-R and its regulator gene (rgg), was cloned and sequenced. Comparison of the deduced amino acid sequence revealed that the rgg genes of S. oralis and S. gordonii exhibited a close similarity. The gtfR gene was found to possess a species-specific nucleotide sequence corresponding to the N-terminal 130 amino acid residues. Insertion of erm or aphA into the rgg or gtfR gene resulted in decreased GTase activity by the organism and changed the colony morphology of these transformants. These results indicate that S. oralis GTase may play an important role in the subsequent colonizing of mutans streptoccoci.

Amino Acid Sequence↗

PubMed2000

Periodontopathic bacteria in children with Down syndrome.

BACKGROUND: It is widely known that individuals with Down syndrome (DS) often develop severe early-onset periodontal diseases. In this study, we examined the prevalence of periodontopathic bacteria in DS children to determine if specific pathogens are acquired in their childhood. METHODS: The subjects were 60 DS children (2 to 13 years old, 5 in each age bracket) and 60 age-matched controls. Ten pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Treponema denticola, Prevotella intermedia, P nigrescens, Capnocytophaga ochracea, C. sputigena, Campyrobacter rectus, and Eikenella corrodens were surveyed in subgingival plaque samples using a polymerase chain reaction. Periodontal status was evaluated by probing depth, bleeding on probing, and gingival index. RESULTS: No significant difference in periodontal status was observed between the DS and control groups, however, all of the pathogens were detected with greater frequency in the DS children. B. forsythus, T. denticola, P. nigrescens, and C. rectus were significantly prevalent throughout all age brackets of the DS children (P <0.01 or 0.05). The occurrence of P. gingivalis was also significant in the DS subjects over 5 years old. A cluster analysis of the microbial profiles of the DS subjects showed that gingivitis severity was associated with increased varieties of the harboring pathogens and the distribution of P. gingivalis. CONCLUSIONS: These results suggest that various periodontopathogens can colonize in the very early childhood of DS patients and maturation of subgingival components, including P. gingivalis, plays an important role in the initiation of gingival inflammation.

Adolescent↗

PubMed2000

[Anesthetic management of cesarean section for a patient with idiopathic thrombocytopenic purpura].

A 39-year-old parturient with idiopathic thrombocytopenic purpura (ITP) was scheduled for cesarean section at 37 weeks gestation. ITP, diagnosed during the first pregnancy, recurred during the second pregnancy, and she was treated with high dose gamma-globulin and platelets transfusion to increase her platelets count over 5.0 x 10(4) x microliter-1 before cesarean section. During the operation under general anesthesia with propofol and pentazocin, atonic hemorrhage occurred gradually with increasing blood loss after the parturition. Since administration of oxytocin, ergometrine maleate, and prostaglandin E1 could not improve the uterine contraction, the hysterectomy was performed to control massive bleeding (finally 8200 g). Packed red cells (22 units) and platelets (40 units) were transfused and fresh frozen plasma (28 units) was infused during anesthesia. Management of ITP during pregnancy is important to prevent hemorrhagic complications because of a narrow safety margin of parturient and fetus.

Adult↗

PubMed1999

Immunohistochemical localization of calbindin D28k during root formation of rat molar teeth.

The present study was undertaken to examine the localization of calbindin D28k (CB)-like immunoreactivity (-LI) during the root formation of the rat molar. In the adult rat, CB-LI was detected in some of the cells of the epithelial rest of Malassez at the bifurcational region and in certain cells between the root dentin and cementum at the apical region. These cells had indented nuclei and many tonofilaments, and cementocytes lacked CB-LI. Moreover, CB-LI was observed in the periodontal fibroblasts in the alveolar half of the apical region. During root formation, the cells in the Hertwig's epithelial root sheath (HERS) lacked CB-LI, but most fragmented cells along the root surface began to express CB-LI when HERS was disrupted. Preodontoblasts and odontoblasts at the apical portion of the root also showed CB-LI. After the formation of cellular cementum, the CB-immunoreactive (-IR) cells were entrapped between the root dentin and cementum in the apical portion of the root. The number of CB-IR cells at the root surface decreased gradually, while that between the root dentin and cementum increased. The fibroblasts in the periodontal ligament began to express CB-LI after commencement of the occlusion, and the number and the staining intensity of CB-IR fibroblasts increased gradually with the passage of time. The present results suggest that CB may play an important role in the survival of the epithelial cells, in the cellular responses of periodontal fibroblasts against mechanical forces caused by the occlusion, and in the initial mineralization by the odontoblasts through the regulation of intracellular Ca(2+) concentration.

Animals↗

PubMed1999

Stimulation of proliferation and differentiation of dog dental pulp cells in serum-free culture medium by insulin-like growth factor.

Insulin, insulin-like growth factors (IGF) I and II are considered to play an important part in the growth and differentiation of dental pulp cells. The present study examined the effects of these factors on pulp cells in serum-free culture conditions. The DNA content and alkaline phosphatase (ALPase) activity of dog pulp cells increased when they were cultured in a serum-free medium supplemented with transferrin, yolk lipoprotein and basic fibrobrast growth factor (TYF medium). The pulp cells produced type I collagen but not type III, suggesting that they might proliferate and differentiate into odontoblast-like cells in a serum-free culture. Both IGF-I and IGF-II enhanced the ALPase activity of pulp cells cultured in TYF medium to an equivalent level, but a higher concentration of IGF-II was necessary to produce a similar effect on DNA synthesis to that of IGF-I. Insulin dose-dependently enhanced DNA synthesis and increased ALPase activity, but its effects were weaker than those of the IGFs. These findings suggest that IGF-I might have a primary role in the growth and differentiation of pulp cells.

Alkaline Phosphatase↗

PubMed1999

Delayed development or congenital absence of a single first permanent molar in Japanese child patients.

OBJECTIVE: Delayed eruption of the first permanent molar (M1) is a relatively rare finding. This report describes the occurrence of delayed development and eruption of a single M1 in Japanese child patients. DESIGN: Cases were identified by surveying 353 orthopantomograms taken of child patients attending a Dental Hospital. Dental age, crown morphology and the presence of third permanent molars (M3) were determined from radiographs and clinical examination. SETTING: Osaka University Dental Hospital in Japan. RESULTS: Nine cases were identified from radiographs. The occlusal morphology of the affected molars showed a reduction of the distolingual cusp. Dental ages correlated more closely to chronological ages when the affected teeth were assumed to be second permanent molars (M2) than they did when the teeth were assumed to be M1. M3 proximate to the affected molar was congenitally absent in the orthopantomograms of all affected subjects. CONCLUSIONS: It is suggested that in the cases seen here the affected teeth were likely to have been second permanent molars that had migrated mesially in association with the congenital absence of M1, although congenital absence of M1 has been reported to be extremely rare.

Adolescent↗

PubMed1998

Molecular analyses of glucosyltransferase genes among strains of Streptococcus mutans.

Three glucosyltransferase (GTase) genes (gtfB, gtfC and gtfD) were cloned and sequenced from clinically isolated strains of Streptococcus mutans MT8148 (serotype c), MT4239 (c), MT4245 (e), MT4467 (e) and MT4251 (f), respectively. Comparison of the gtf genes revealed that interstrain difference of gtfB and gtfD was limited, while gtfC showed significant interstrain variations. Similar to gtfB and gtfD, gtfC possessed five direct repeats composed of homologous unit in the carboxyl-terminal portion. The repeating unit consisted of 63-65 amino acid residues and is responsible for glucan binding. The gtfC gene from S. mutans MT4245 lacked the fourth unit. Multiple alignment with the gtf sequence of strain GS-5 (c) revealed several changes in these gtf genes due to frameshift mutations. The peptides encoded by the gtfB, gtfC and gtfD genes of GS-5 were 1, 80, and 32 amino acid residues shorter than those of the test strains except strain MT4245.

Bacterial Proteins↗

PubMed1998

Comparison of the cariostatic effects between regimens to administer oolong tea polyphenols in SPF rats.

The cariostatic effect of oolong tea polyphenols administered according to several regimens was examined in specific pathogen-free (SPF) Sprague-Dawley rats given both a diet containing 20% sucrose and infected with S. sobrinus 6715. The crude preparation (OTE) of oolong tea polyphenols showed the most prominent effect on caries reduction in SPF rats when OTE was administered in the drinking water beginning 1 day prior to the inoculation of S. sobrinus 6715, when compared with chromatographically isolated polyphenol fractions (OTF1 and OTF6) of OTE. Reduction in caries development was found even when OTE was given 1 day after inoculation of the organism. OTE was shown to significantly inhibit dental caries in rats at the concentrations of either more than 5 microg/ml in drinking water or more than 10 microg/g in diet. OTF1 and OTF6 also showed significant inhibition of caries induction, with the minimum inhibitory concentration of OTF6 being 50 microg/ml in drinking water and the minimum inhibitory concentration of OTF1 being 100 microg/g in diet. These results indicate that cariostatic activity of OTE was effective even after the establishment of S. sobrinus in the oral cavity and was more effective in drinking water than in diet. Furthermore, OTE may contain some anticaries substances that affect the virulence of S. sobrinus other than glucosyltransferases.

Analysis of Variance↗