The purpose of this study was to investigate the intrafamilial distribution of mutans streptococci in Japanese families using chromosomal DNA fingerprinting with three endonucleases; EcoRI, HindIII and HaeIII. The analysis of 1,908 isolates cultured from the dental plaque of 76 subjects from 20 families (20 married couples and 36 of their children) resulted in the identification of 144 genotypes containing 114 strains of Streptococcus mutans (serotype c, 66.7%; e, 12.5%) and 30 strains of S. sobrinus (d, 13.2%; g, 7.6%). A mean of 1.89 genotypes (from one to four) was harbored in individual subjects, and a mean of 4.10 genotypes from two to seven was harbored in individual families. Among the 70 genotypes found in the children, 36 (51.4%) were in agreement with their mothers and 22 (31.4%) were in agreement with their fathers. The other genotypes (18.6%) did not correspond with the parents. Homologous strains between parents were found in only two couples. This result showed that fathers or others as well as mothers can be sources of transmission. Further, the serotype d, e and g strains showed significantly higher probabilities of transmission than serotype c.

The purpose of this study was to detect the presence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in plaque samples from 104 children, collected from their toothbrushes using a polymerase chain reaction (PCR). The age range of all subjects was 2-12 years. 21, 73 and 10 children with healthy gingiva, gingivitis and periodontitis respectively were selected. Plaque samples were collected from all erupted teeth sites using a sterile toothbrush. The mean concentration of DNA recovered from brushing plaque samples was approximately 660 microg/ml, which was sufficient for performing a PCR-based survey. Both A. actinomycetemcomitans and P. gingivalis were detected in the primary and mixed dentition. The prevalence of A. actinomycetemcomitans in healthy subjects was 4.8%, and those with gingivitis and periodontitis was 6.8% and 20.0% respectively, while the prevalence of P. gingivalis was 4.8% in healthy subjects, and 9.6% and 20.0% in those with gingivitis and periodontitis, respectively. Our survey, using a toothbrush, indicated that A. actinomycetemcomitans and P. gingivalis are rarely present in oral cavities of healthy children.

Our survey indicated that P. intermedia and T. denticola were more associated with periodontal diseases, B. forsythus and P. nigrescens had a moderate prevalence in all clinical groups, while C. rectus were the most commonly detected species in the oral cavities of children suggesting establishment in their early years.

Three hundred and seven children who had no diseases other than dental disease were examined for their oral carriage of Staphylococcus aureus, the most common persistent human pathogen. Eighty-four percent of them were positive for staphylococci, and 33% were positive for S. aureus. Among the 100 strains of S. aureus isolated, 40 strains produced enterotoxin, and 19 strains produced exfoliative toxin. Their susceptibility to antibiotics was also investigated: Six strains demonstrated resistance to methicillin (MIC greater than or equal to 12.5 microgram/mL), and 50% of the isolates were borderline resistant (MIC of 3.13 to 6.25 micrograms/mL) to the drug. These data suggest that the mouths of children could be reservoirs of pathogenic S. aureus.

The purpose of this study was to investigate the relationship between gingival health and dental caries in elementary school children in Japan. The subjects were 474 children aged 7 to 12 years who attended dental checkups at an elementary school. The Oral Rating Index for Children, which consists of five categories (+2, +1, 0,-1,-2), was used to rate the findings of the gingival health e:xamination. The dental examination was performed using the WHO caries diagnostic criteria for DMFT. Children were divided into three groups: a healthier group (H-group) made up of those scoring +2 (excellent) or +1 (good), an equivocal group (E-group) made up of those scoring 0, and a gingival less-healthy group (L-group) made up of those scoring-2 (very poor) or-1 (poor). Overall percentages for the H-group, E-group and L-group were 48.3 %,21.5 % and 30.2 %, respectively. The number in the L-group increased with increasing age. The mean scores of the DT and DMFT in the H-group were significantly lower than those in the L-group (p < 0.01 and p < 0.05, respectively). The results suggest that oral hygiene instruction should be given to children in order to motivate self-care, not only to avoid dental caries but also to prevent gingivitis.

Oleanolic acid and ursolic acid, extracted and purified from crude drugs, inhibited the insoluble glucan synthesis catalyzed by a crude glucosyltransferase (GTase) preparation from cariogenic Streptococcus mutans OMZ 176. Inhibition of the insoluble glucan synthesis was dependent on the concentration of oleanolic acid or ursolic acid, and was enhanced by pretreatment of crude GTase with these substances. In contrast, synthesis of soluble glucan was not significantly inhibited. These findings suggest that the substances inhibit mainly the synthesis of α-1,3-linkage but not that of α-1,6-linkages. These results indicate that oleanolic acid and ursolic acid are potential inhibitors of dental plaque formation and dental caries.

The Golgi complex plays a prominent role in the modification and sorting of lipids and proteins, and is a highly dynamic organelle that is dispersed and rearranged before and after mitosis. Several reagents including 4-nitrobenzo-2-oxa-1,3-diazole-labeled C6-ceramide (NBD-C6-ceramide, a ceramide having an NBD-bound C6-N-acyl chain) and Golgi-specific proteins that emit fluorescence are used as Golgi markers. In the present study, we synthesized a new ceramide analog, acetyl-C16-ceramide-NBD (a ceramide having an acetylated C-1 hydroxyl group, C16-N-acyl chain, and NBD-bound C15-sphingosine), and showed that it preferentially accumulated in the Golgi complex without cytotoxicity for over 24 h. Pathways for cellular uptake and interorganelle trafficking of acetyl-C16-ceramide-NBD were investigated. Acetyl-C16-ceramide-NBD was transported to the Golgi complex via ceramide transport proteins. In contrast to NBD-C6-ceramide, acetyl-C16-ceramide-NBD was resistant to ceramide metabolic enzymes such as sphingomyelin synthase and glucosylceramide synthase. Because of its weaker cytotoxicity and resistance to ceramide metabolic enzymes, the localization of the Golgi complex could be observed in acetyl-C16-ceramide-NBD-labeled cells before and after mitosis. Lipids including sphingolipids play a structural role in the cellular membranes, and regulate physiological and pathological conditions in cells and tissues and in vivo by themselves. The backbone structure of sphingolipids including ceramide is sphingosine, and sphingosine-1-phosphate (S1P, the phosphate ester of the C-1 position of sphingosine) is an important signaling molecule (1,2). Ceramide, which has an N-acyl chain at the C-2 position of sphingosine, is a central point from where various sphingolipids are synthesized and interconverted. The hydroxyl (OH) † These authors contributed equally to this work.group at the C-1 position of ceramide is modified by various enzymes: phosphorylation by ceramide kinase and glucosylation by glucosylceramide (GlcCer) synthase produce ceramide-1-phosphate (C1P) and GlcCer, respectively. Sphingomyelin (SM) synthase transfers a phosphocholine head group from phosphatidylcholine to the OH group at the C-1 position of ceramide and produces SM.Many studies previously reported the usefulness of fluorescence-labeled ceramides and ceramide-related molecules in the study of uptake systems and the intracellular traffic of molecules. 4-Nitrobenzo-2-oxa-1, 476 www.traffic.dk

No abstract