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.

Velopharyngeal closure pattern exerted by contraction of the pharyngeal constrictor muscle in dogs.

Objective: This study was performed to investigate aspects of velopharyngeal closure demonstrated by movements of the parapharyngeal wall under various physiological conditions and especially the stimulation of several intrapneumonal receptors.

Materials And Methods: Fifteen mongrel dogs were anesthetized and a nasopharyngeal fiberscope was inserted from the oronasal fistula at the center of the hard palate, with the tip fixed around the choana. Mechanical and chemical stimulation was applied, and ongoing velopharyngeal movements were observed.

Prevalence of specific genotypes of Porphyromonas gingivalis fimA and periodontal health status.

Porphyromonas gingivalis fimA gene encoding fimbrillin, a subunit of fimbriae, has been classified into 5 genotypes (types I to V) based on their nucleotide sequences. Here, we investigated the relationship between the prevalence of these fimA genotypes and periodontal health status in adults. Dental plaque specimens obtained from 380 periodontally healthy adults and 139 periodontitis patients were analyzed by the PCR method.

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.

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.

Hedgehog proteins stimulate chondrogenic cell differentiation and cartilage formation.

Sonic hedgehog (Shh) and Indian hedgehog (Ihh) are important regulators of skeletogenesis, but their roles in this complex multistep process are not fully understood. Recent studies have suggested that the proteins participate in the differentiation of chondrogenic precursor cells into chondrocytes. In the present study, we have tested this possibility more directly.

Keratin 14 immunoreactive cells in pleomorphic adenomas and adenoid cystic carcinomas of salivary glands.

Our recent study of developing myoepithelial cells (MECs) in rat salivary glands demonstrated that developing MECs begin to express alpha-smooth muscle actin (alphaSMA) first and, thereafter, keratin 14. Therefore, it is unlikely that duct basal cells expressing keratin 14 alone are immature or undifferentiated MECs. In this study we carried out immunohistochemistry of pleomorphic adenomas and adenoid cystic carcinomas including normal salivary glands using monoclonal antibodies to keratin 14, smooth muscle proteins and keratin 19.

Parathyroid hormone-related peptide is involved in protection against invasion of tooth germs by bone via promoting the differentiation of osteoclasts during tooth development.

In order to elucidate the role of parathyroid hormone-related peptide (PTHrP) in tooth development, we treated tooth germ explants of mouse molars with antisense phosphorothioate-oligodeoxynucleotide (ODN) against PTHrP. Antisense ODN-treatment of the explants resulted in the invasion of the tooth germs by bone. The number of tartrate-resistant acid phosphatase (TRAP)-positive cells around the tooth germs in antisense ODN-treated explants was much lower than that of the control explants.

Effects of neonatal injury of the inferior alveolar nerve on the development and regeneration of periodontal nerve fibers in the rat incisor.

Our previous study showed that the migration of terminal Schwann cells occurred in the periodontal ligament of the rat lower incisor following transection of the inferior alveolar nerve (IAN) in the adult animals [Y. Atsumi, K. Matsumoto, M.

Transcription factor ERG variants and functional diversification of chondrocytes during limb long bone development.

During limb development, chondrocytes located at the epiphyseal tip of long bone models give rise to articular tissue, whereas the more numerous chondrocytes in the shaft undergo maturation, hypertrophy, and mineralization and are replaced by bone cells. It is not understood how chondrocytes follow these alternative pathways to distinct fates and functions. In this study we describe the cloning of C-1-1, a novel variant of the ets transcription factor ch-ERG.

Morphological and cytochemical characteristics of periodontal Ruffini ending under normal and regeneration processes.

Current knowledge on the Ruffini endings, primary mechanoreceptors in the periodontal ligament is reviewed with special reference to their cytochemical features and regeneration process. Morphologically, they are characterized by extensive ramifications of expanded axonal terminals and an association with specialized Schwann cells, called lamellar or terminal Schwann cells, which are categorized, based on their histochemical properties, as non-myelin-forming Schwann cells. Following nerve injury, the periodontal Ruffini endings of the rat incisor ligament can regenerate more rapidly than Ruffini endings in other tissues.

Relation of motility of subgingival microflora as a clinical parameter to periodontal disease status in human subjects.

Background/aims: The purpose of this study was to evaluate the possible relationship between the motility of subgingival microflora and 5 clinical parameters commonly used in dental clinics.

Method: The clinical parameters were pocket depth, gingival inflammation, plaque accumulation, bleeding on probing and pus discharge. The motility of human subgingival microflora was estimated as the number of pixels remaining after subtraction of serial video frames using a high speed shutter camera and image analysis system, and was defined as the sum of pixels of 10 successive subtractions per sample over a 10-s time period.

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.

Adenosine regulates the production of interleukin-6 by human gingival fibroblasts via cyclic AMP/protein kinase A pathway.

Adenosine has been reported to alter a variety functions of the cells that participate in inflammatory responses. However, the effect(s) of adenosine on human gingival fibroblasts (HGF), one of the immunomodulator cells in inflamed periodontal lesions, remains to be established. In this study, we examined the influence of adenosine on the production of interleukin (IL)-6 by HGF.

GABA(A) receptor-mediated effects on expression of c-Fos in rat trigeminal nucleus following high- and low-intensity afferent stimulation.

We examined the effects of systemic administration of a GABA(A) receptor agonist, muscimol, or antagonist, bicuculline, on the expression of c-Fos protein induced 3h after electrical stimulation of the trigeminal ganglion at low (0.1 mA) or high intensities (1. 0 mA) in the urethane-anesthetized rat.

Effect of surface roughness of porcelain on adhesion of bacteria and their synthesizing glucans.

Statement Of Problem: In some instances of porcelain restoration, refinishing is inevitable. In terms of plaque accumulation on porcelain, refinishing could be a substitute method for glazing.

Purpose: This study compared the amount of adhesion of plaque components (bacterial cells and glucans) on porcelain disks with various degrees of surface roughness to assess the effects of surface roughness on the amount of plaque accumulation.

Plaque removal efficacy of the V-shaped toothbrush with new designs in bristle arrangement.

Experimental bristle arrangements were applied to a conventional V-shaped bristle-design toothbrush in an effort to improve plaque removal efficacy in interproximal areas. A single-blind cross-over study was performed to evaluate the plaque removal efficacy of this new bristle arrangement by comparing it to either a more conventional V-shaped toothbrush or a flat-headed toothbrush. Plaque removal efficacy was determined by assessing the percentage of plaque score reduction following a single controlled brushing.

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.

Effects of resin composite components on glucosyltransferase of cariogenic bacterium.

The aim of our study was to investigate the effect of resin composite components on glucan synthesis by glucosyltransferase (GTase) derived from a cariogenic bacterium, Streptococcus sobrinus B13. The eluates from cured composites stored in 0.05 mol/L potassium phosphate buffer (KPB) (pH 6.

Pocket oxygen tension in smokers and non-smokers with periodontal disease.

Background: Smoking is associated with destructive periodontal disease. Pocket oxygen tension (pO2) is likely to be a major environmental determinant of the subgingival microflora, which is a primary etiological factor of the disease. This study aimed to compare the pocket pO2 in smokers and non-smokers with periodontal disease.

Effects of four mixing methods on setting expansion and compressive strength of six commercial phosphate-bonded silica investments.

Six commercial phosphate-bonded silica investments were mixed with four different mixing methods such as hand, two conventional blade-driven vacuum mixers and a new planetary mixing device, and examined for their setting expansion and compressive strength. The two properties often altered, depending upon the mixing method and the investment. The setting expansion of three investments were significantly affected by the mixing method while those of the other three were not.

Distribution and molecular characterization of Porphyromonas gingivalis carrying a new type of fimA gene.

Fimbriae of Porphyromonas gingivalis are filamentous appendages on the cell surface and are thought to be one of the virulence factors. The fimA gene encoding the subunit protein of fimbriae, fimbrillin (FimA), was classified into four typeable variants (types I to IV). We previously examined the distribution of P.

Relationship of the substance P to indicators of host response in human gingival crevicular fluid.

Background: The substance P (SP) level in human gingival crevicular fluid (GCF) was studied in relation to clinical periodontal variables and to various indicators of host response in the GCF.

Methods: GCF was collected from periodontal sites with gingival inflammation and shallow or moderately deep pocket in 48 subjects. The total amount of SP and the substances based on host response factors in a 30-s sample were determined by ELISA and enzymatic methods.

Effects of combined oral treatments with cyclosporine A and nifedipine or diltiazem on drug-induced gingival overgrowth in rats.

Background: Cyclosporine A (CsA) and calcium channel blockers induce gingival overgrowth in humans and animals. Recently, nifedipine and diltiazem have often been used to control CsA-related hypertension in organ transplant patients. The purpose of this study was to examine the effects of a combined oral treatment of CsA and nifedipine or diltiazem on the severity of gingival overgrowth in rats.