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H Mayanagi

Publications and source records attributed to H Mayanagi.

At least 19 recordsLinked to original sources
PubMed2006

A case of Coffin-Lowry syndrome with premature exfoliation of primary teeth.

We present a case of a 5-year-old boy with premature exfoliation of primary teeth. All eight primary incisors had exfoliated by the age of 3 years, and three canines and one primary first molar were subsequently lost when he was 4 years old. None of the exfoliated teeth exhibited caries. The boy also showed characteristic facial changes, tapering of the fingers, and mental and motor retardation. Based on these findings, he was diagnosed as having Coffin-Lowry syndrome. Premature exfoliation of primary teeth in Coffin-Lowry syndrome has been described in a few reports. This manifestation of the disease would be helpful for diagnosis at an early stage as those previous reports suggested.

Child, Preschool↗
PubMed2006

Quantitative detection of Streptococcus mutans in the dental plaque of Japanese preschool children by real-time PCR.

AIMS: To detect quantitatively the total bacteria and Streptococcus mutans in dental plaque by real-time PCR with prbac, Sm and GTF-B primers, and to compare their presence with the prevalence of dental caries in Japanese preschool children. METHODS AND RESULTS: Human dental plaque samples were collected from the labial surfaces of the upper primary central incisors of 107 children. The dental status was recorded as dft by WHO caries diagnostic criteria. Positive dt and dft scores by the Sm or GTF-B primer were significantly higher than negative scores (P < 0.01). The proportions of Strep. mutans to the total bacteria from sound, and sound and/or filled upper primary incisors were significantly lower than those from decayed or filled, and decayed incisors, respectively (P < 0.01). CONCLUSIONS: The ratios of Strep. mutans to total bacteria in plaque detected by real-time PCR with Sm and GTF-B primers were closely associated with the prevalence of dental caries in Japanese preschool children. SIGNIFICANCE AND IMPACT OF THE STUDY: These assays may be useful for the assessment of an individual's risk of dental caries.

Child↗
PubMed2005

Inhibition of inflammatory and bone-resorption-inhibitory effects of alendronate by etidronate.

Among the bisphosphonates (BPs), the aminobisphosphonates (aminoBPs) have much stronger bone-resorption-inhibitory activities (BRIAs) than nonaminobisphosphonates (nonaminoBPs). However, aminoBPs have inflammatory effects. We previously reported that in mice: (i) all aminoBPs tested (10-40 micromol/kg) induced various inflammatory reactions (including induction of histidine decarboxylase), whereas clodronate (a non-aminoBP) (10-160 micromol/kg) inhibited these reactions; and (ii) a clear sclerotic line (tentatively called the BP line) was detectable in the tibia by radiography a few weeks after a single injection of either alendronate (a typical aminoBP) (1.6 micromol/kg) or clodronate (160 micromol/kg), and this BP-line formation (a marker for the BRIAs of BPs) was not reduced in mice given both alendronate and clodronate. In this study, using this murine model, we compared clodronate, etidronate (another typical non-aminoBP), alendronate, etidronate + alendronate, and clodronate + alendronate in terms of their inflammatory effects and/or BP-line formation. For BP-line formation, 480 micromol/kg etidronate was needed (single injection). At 160 micromol/kg, etidronate inhibited the histidine decarboxylase induction, but not the other inflammatory reactions induced by alendronate. However, etidronate (unlike clodronate) also inhibited alendronate-induced BP-line formation (even at 40 micromol/kg). Etidronate (160 micromol/kg) also inhibited the physicochemical changes in the tibia induced by six, weekly injections of alendronate. Therefore, depending on the dose, etidronate can inhibit alendronate's inflammatory actions and its BRIA. These results, together with those reported previously, suggest that a strategy utilizing clodronate (but not etidronate) plus an aminoBP might prevent or reduce the inflammatory side effects induced by aminoBPs while preserving their powerful BRIAs. We discuss the mechanisms underlying the antagonism between aminoBPs and non-aminoBPs.

Alendronate↗
PubMed2004

Effects of the antiepileptics phenytoin and zonisamide on dentin formation and bone mineral density of the mandible in growing rats.

This study was undertaken to examine the effects of the antiepileptics phenytoin and zonisamide on changes in the mineral density of the incisor and bone mineral density (BMD) of the mandibular head, and on the rate of dentin formation using histomorphometric measurements. After repeated administration of phenytoin or zonisamide to male growing rats, the mineral density of the lower incisors and mandibular head were determined by analyzing microradiographs and dentin formation rates were determined by histomorphometric measurements. Results showed a significant decrease in the mean values of BMD of the mandibular head and lower incisors in groups treated with phenytoin or zonisamide compared with the vehicle-treated group (p < 0.05). The percent rates of decrease in mineral density of the incisors for phenytoin and zonisamide were 6.8% and 4.0%, respectively. Phenytoin and zonisamide significantly reduced the dentin formation rate for the mesial and distal areas compared with the vehicle-treated group. Thus, epileptic children who are treated over a long period with antiepileptics, especially at primary school age, should ensure good oral hygiene so as not to suffer bone loss, edentulism or gingival overgrowth.

Animals↗
PubMed2003

Effects of weekly administrations of alendronate+clodronate on young mouse tibia: localized action at the proximal growth plate.

Alendronate (A), a typical aminobisphosphonate (aminoBP), has a strong bone-resorption-inhibitory activity (BRIA). However, like other aminoBPs it has inflammatory side effects. In contrast, the BRIA of clodronate (C), a non-aminoBP, is much weaker, and in animal experiments it suppresses aminoBP-induced inflammatory reactions. In the present study, we examined the effects of weekly administrations of A (1.6 micro mol/kg) + C (160 micro mol/kg) on the tibias in young mice and compared them to those induced by A or C alone. Radiophotography showed that A increased bone density at a selective site in the tibia. Indeed, one week after the final injection of A (given alone), clear sclerotic lines (tentatively called BP-lines) were visible at sites corresponding to the location of the growth plate at the time of the each injection. C also produced BP-lines, although they were weaker than those produced by A. Combined administration of A and C produced similar BP-lines as seen in mice given A alone. These results together with other physicochemical effects of A on the tibia suggest that (1) each injection of A and C inhibits bone resorption selectively and transiently at the tibial growth plate in young mice, although minor effects on other sites cannot be excluded, and (2) the combination of A and C keeps still a strong BRIA. Our findings may suggest a strategy for the prevention or reduction of some inflammatory side effects of A or other aminoBPs.

Alendronate↗
PubMed2003

Acid diffusion through extracellular polysaccharides produced by various mutants of Streptococcus mutans.

Mutants of Streptococcus mutans V403, constructed by allelic exchange and altered in their capacity to produce enzymes involved in the production of extracellular polysaccharides from sucrose, were used to study the role of glucans and fructans in the diffusion of ions through cell concentrates. A 4.0mm diameter, 0.75 mm deep diffusion chamber with an ion-sensitive field-effect transistor electrode positioned at the base was used to monitor the diffusion of hydronium ions from a sodium lactate buffer using cell concentrates prepared from bacteria grown in various concentrations of sucrose and glucose. The wild-type strain V403 produced at least seven times as much water-insoluble glucan (ISG) from sucrose as mutants deficient in various combinations of glucosyltransferase B (GTF B), GTF C, GTF D and fructosyltransferase. The fastest diffusion of hydronium ions occurred with sucrose-grown cell concentrates of strain V403, and the time of diffusion to the bottom of the chamber was approximately 2.3 times longer when this strain was grown in glucose. The speed of diffusion with glucose-grown V403 was similar to that obtained with each of the mutants. When cells of strain V403 grown in sucrose and glucose were mixed, increases in diffusion speed were found to be directly related to the proportion of sucrose-grown cells. The mixing of ISG with several strains of S. mutans revealed that increases in diffusion speed were directly related to the quantity of ISG added.

Acids↗
PubMed2003

Xylitol inhibition of anaerobic acid production by Streptococcus mutans at various pH levels.

Xylitol inhibits the glycolysis and growth of Streptococcus mutans. We studied the inhibitory effect of xylitol on the acid production of S. mutans at several pH levels under the strictly anaerobic conditions found in the deep layer of dental plaque. Xylitol inhibited the rate of acid production from glucose and changed the profile of acidic end products to formate-acetate dominance, with a decrease in the intracellular level of fructose 1,6-bisphosphate and an intracellular accumulation of xylitol 5-phosphate (X5P). These results were notable at pH 5.5-7.0, but were not evident at pH 5.0. Since the activity of phosphoenolpyruvate phosphotransferase for xylitol was greater at higher pH, it is suggested that xylitol could be incorporated more efficiently at higher pH and that the resultant accumulation of X5P could inhibit the glycolysis of S. mutans more effectively.

Acetic Acid↗
PubMed2002

Intracellular and extracellular pHs of Streptococcus mutans after addition of acids: loading and efflux of a fluorescent pH indicator in streptococcal cells.

A pH-sensitive fluorescent dye, 2', 7'-bis-(2-carboxyethyl)-5 and 6-carboxyfluorescein (BCECF), was used to determine intracellular pH (pH(in)). The efflux of BCECF loaded into oral streptococcal cells was determined after incubation of the cells at 35 degrees C for 20 min in the presence and absence of glucose. In the absence of glucose, the fluorescence of intracellular BCECF in Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius and Streptococcus sobrinus decreased only very slightly, indicating that the dye could be useful for pH(in) determination. In the presence of glucose, however, the fluorescence decreased by 57%. Thus, the pH(in) of S. mutans cells was measured by the BCECF method in the absence of glucose at various acidic pH levels by adding lactic, acetic and hydrochloric acids to the cell suspensions. The pH(in) was almost equal to the extracellular pH (pH(out)) for pH(out) values of between 8 and 5, indicating that protons permeated easily across the S. mutans cell membrane. For pH(out) between 5 and 4, pH(in) was constant at around 5, suggesting that the cell membrane was impermeable to protons, or that a cytoplasmic buffering system functioned. pH(in) decreased at pH(out) values of < 4. The constant pH(in) at acidic pH(out) levels could protect intracellular components, such as proteins, against acidification by sugar fermentation.

Acetic Acid↗
PubMed2001

Inflammatory reactions in extraoral tissues in mice after intragingival injection of lipopolysaccharide.

Intragingival (ig) injection into mice of lipopolysaccharide (LPS) from Prevotella intermedia or Escherichia coli elevated the activity of the histamine-forming enzyme, histidine decarboxylase (HDC), in the mandible, liver, lung, and spleen, with a time course similar to that seen with intravenous (iv) injection. The effect of i.g. injection was less than that of i.v. injection but similar to that of intraperitoneal (ip) injection. The i.g. injection also increased hepatic serotonin, reflecting platelet accumulation. In galactosamine-treated mice, the minimum ig dose of LPS needed to induce lethal hepatitis was very small (less than that needed by ip injection). These results support the idea that the LPS produced in oral tissues may be transported easily to extraoral tissues and, in some cases, may cause inflammatory or immune responses. It also may influence the pathogenesis of some systemic diseases.

Animals↗
PubMed2001

Phenytoin-induced bone loss and its prevention with alfacalcidol or calcitriol in growing rats.

Studies were carried out to determine the effects and mechanism of action of phenytoin on the bone metabolism in male rats. Administration of phenytoin, 20 mg/kg/ day for 5 weeks, did not affect the growth curve. Biochemical data indicated that the serum osteocalcin, a marker of bone formation, was decreased significantly but there were no significant differences in the levels of serum calcium, pyridinoline, 25-hydroxyvitamin D3 (25OHD) and parathyroid hormone (PTH) in the phenytoin-treated group compared with the vehicle-treated group. The values of bone mineral density (BMD) were decreased in all regions of bones tested (mandibular head, tibial metaphysis, tibial diaphysis, femoral metaphysis, and femoral diaphysis) in the phenytoin-treated group. In histomorphometric analysis, phenytoin decreased trabecular bone volume and trabecular thickness, and increased osteoclast numbers per area of bone surface in the secondary trabecular bone of the tibia. Additionally, there was no significant difference in osteoid thickness. Combined administration of either alfacalcidol or calcitriol with phenytoin for 5 weeks prevented the reduction of BMD induced by phenytoin. From these findings, it is unlikely that toxic effects on the growth curve caused the decreased BMD induced by phenytoin. It is also evident that repeated administration of phenytoin may cause osteopenia which may be due to bone loss by inhibiting bone formation and/or by accelerating bone resorption rather than osteoid accumulation. The bone loss is not rachitic because of the lack of increase in osteoid thickness. Moreover, combined administration of alfacalcidol or calcitriol with phenytoin showed a preventative effect against bone loss. The bone loss induced by phenytoin in this study may be a convenient model for further research into the problem of drug-induced osteopenia.

Animals↗
PubMed2001

The time-course of acid excretion, levels of fluorescence dependent on cellular nicotinamide adenine nucleotide and glycolytic intermediates of Streptococcus mutans cells exposed and not exposed to air in the presence of glucose and sorbitol.

The aim of this study was to examine glucose and sorbitol metabolism in Streptococcus mutans cells exposed and not exposed to air at the coexistence of these compounds by measuring acid excretion, levels of fluorescence dependent on cellular NADH and glycolytic intermediates. An aliquot of bacterial cells grown under strictly anaerobic conditions (anaerobic cells) was exposed temporarily to air (aerobic cells). When glucose was added to the anaerobic cells metabolizing sorbitol, the acid excretion was increased. The level of NADH decreased initially and then increased to the higher plateau level than that during glucose metabolism. The aerobic cells neither metabolized sorbitol nor contained glycolytic intermediates. However, 2 min after glucose was added in the presence of sorbitol, the acid excretion was started slowly and the intermediates appeared. The level of NADH was decreased at first and then increased. These results suggested that the anaerobic S. mutans cells metabolized glucose and sorbitol simultaneously, and that in the presence of sorbitol the aerobic cells could start to metabolize glucose 2 min after glucose was added, as the intermediates (phosphoenopyruvate potential) for the glucose transport were accumulated.

Acids↗
PubMed2001

Utilization and acid production of beta-galactosyllactose by oral streptococci and human dental plaque.

Beta-galactosyllactose is a trisaccharide containing the beta-galactosidic linkage at the nonreducing end. The purpose of this study was to determine whether certain oral streptococci could utilize four kinds of beta-galactosyllactoses. Three of four beta-galactosyllactoses were unable to support growth of the oral streptococci and to be a substrate for producing acid from the cell suspensions and dental plaque. 4'-beta-Galactosyllactose supported growth of Streptococcus sanguis ATCC 35105, ATCC 49298, Streptococcus mitis ATCC 15914, Streptococcus oralis ATCC 35037, ATCC 10557 and Streptococcus milleri 10707 and produced acid from dental plaque. Although beta-galactosidase activities were observed in all the strains, 4'-beta-galactosyllactose could not be used as a carbon source for the growth of mutans streptococci. Enzymes metabolizing 4'-beta-galactosyllactose were induced when S. oralis ATCC 10557 was cultured in medium containing galactose. These results suggested that 4'-beta-galactosyllactose could be as cariogenic as lactose if it is consumed frequently and retained for a long period in the mouth.

Acids↗
PubMed2001

Histopathological and immunohistochemical analysis of calcifying odontogenic cysts.

METHOD AND RESULTS: Calcifying odontogenic cysts (COCs) were examined histopathologically and immunohistochemically to characterize the histological and cytological properties of these lesions. Histopathologically, COCs showed thin or thick lining epithelium with ghost cells. COCs were classified according to proliferative type or nonproliferative type lining epithelium, the presence or absence of ameloblastomatous appearance, and the presence or absence of odontoma in the cyst walls. Immunohistochemically, amelogenin protein was expressed chiefly in ghost cells, whereas cytokeratin 19 (CK19) and bcl-2 proteins were expressed chiefly in lining epithelial cells. The proportion of cases positive for bcl-2 protein was slightly higher in COCs with odontoma than in those without odontoma. Lining epithelial cells sporadically showed positive reactions for Ki-67 antigen. Mean Ki-67 labeling index was slightly greater in COCs with proliferative type lining epithelium, COCs with ameloblastomatous appearance of the cyst walls, and COCs with odontoma of the cyst walls than in COCs without these histological features. Our results suggest that ghost cells or lining epithelial cells show ameloblastic cytodifferentiation or odontogenic epithelial characteristics, that bcl-2 protein is associated with survival of lining epithelial cells in COCs, and that high proliferation potential is associated with ameloblastomatous proliferation or combined odontoma. COCs exhibited various histological features with several transitional forms, and immunohistochemical examinations revealed little or no difference in cytodifferentiation and cellular activity among COCs. CONCLUSION: We conclude that COCs with various histological features have neoplastic potential and may not be separate entities within the same histological spectrum.

Adolescent↗
PubMed2001

The dentofacial manifestations of XXXXY syndrome: a case report.

This paper presents a six-year-old patient with XXXXY syndrome, whose oral findings included a cleft soft palate, hyper- or meso-taurodontism in eight primary molars and in the mandibular permanent first molars, five congenitally missing premolars, and delayed development of the permanent tooth germs. The maxillary and mandibular primary central incisors were in a cross-bite relationship. Cephalometric findings showed a short ramus of the mandible and a short maxilla in the anterioposterior plane. The anteroposterior jaw relationship was in harmony. The cross-bite was considered to be due to the retroinclination of the maxillary primary incisors. This case emphasises the importance of regular dental care, and monitoring of facial growth and dental development in children with XXXXY syndrome.

Anodontia↗
PubMed2000

Elevation of histidine decarboxylase activity in the mandible of mice by Prevotella intermedia lipopolysaccharide and its augmentation by an aminobisphosphonate.

Lipopolysaccharide (LPS) produced by Gram-negative bacteria is an important cause of inflammation. Aminobisphosphonates are potent inhibitors of bone resorption but have inflammatory side-effects. Here, the effects of LPS from Prevotella intermedia (a prevalent Gram-negative bacterium both in periodontitis and endodontal infections) and alendronate (an aminobisphosphonate) on the activity of the histamine-forming enzyme, histidine decarboxylase (HDC), were examined in mouse mandible. Intravenous injection of P. intermedia LPS increased HDC activity in the mandible, maximal activity being induced within 3-6 h of the injection. The elevation of HDC activity was dependent on the dose of LPS, 10 microg/kg (0.25 microg/mouse) producing a significant elevation in enzyme activity. Intraperitoneal injection of alendronate (40 micromol/kg) also produced an increase in HDC activity. Moreover, the elevation of HDC activity induced by P. intermedia LPS was markedly augmented in mice given alendronate 3 days before the LPS injection. These results (i) suggest that P. intermedia LPS may stimulate the synthesis of histamine in the mandible and that the newly formed histamine may make at least some contribution to the development of inflammation (apical periodontitis and/or osteomyelitis); (ii) should encourage the clinical testing of antihistaminergic agents against inflammation; and (iii) confirm that care needs to be taken when administering aminobisphosphonates to patients.

Alendronate↗
PubMed2000

Distribution of interglobular dentine in human tooth roots.

The present study was designed to examine the distribution of interglobular dentine in human tooth roots. The material comprised 17 teeth, of which 3 were premolars extracted for orthodontic reasons from children 10-12 years of age and the other teeth (4 incisors, 3 canines and 7 molars) were extracted for periodontitis from individuals aged 32-63 years. All teeth were free of caries and cervical dentine defects. Ground sections of the teeth cut longitudinally were stained with basic fuchsin and observed by fluorescence and confocal microscopy as well as transmitted light microscopy. Basic fuchsin stained the dentinal tubules, interglobular dentine and the granular layer of Tomes. These structures appeared intense blue to faint violet with transmitted light microscopy, whereas their staining displayed intense fluorescence with fluorescence microscopy. Therefore, the interglobular dentine could be detected more sensitively with fluorescence and confocal microscopy than with transmitted light microscopy. Typical interglobular dentine was present in coronal dentine in most of the teeth. In the radicular dentin, position and size of the interglobular dentine was different among the teeth examined. Most of the teeth had the interglobular dentine in the cervical part of the roots (type A). Two premolars displayed the interglobular dentine in the coronal half of the root (type B). The types A and B contained large interglobular areas. A small amount of interglobular dentine was restricted to the apical half of the roots of two canines and one molar (type C). In contrast to types A and B which were seen at both labial or buccal and lingual sides of roots, the interglobular dentine of type C was seen only at one side, labial or lingual. Some of the tooth roots did not show any interglobular dentine (type D). Most of the incisors, canines and premolar were types A, B, and C, respectively, and the molars were mixed types A, C, and D. These results suggest that the factors affecting dentinogenesis during root formation are unique for each tooth.

Adult↗