Mizuho Nishino

Toughness, bonding and fluoride-release properties of hydroxyapatite-added glass ionomer cement

Improving the mechanical strength of glass ionomer cement while preserving its favorable clinical properties such as fluoride release, bonding to tooth structure and biocompatibility is desirable. In this study, hydroxyapatite was incorporated into chemically setting glass ionomer cement and its effect on the fracture toughness, bonding to dentin and fluoride release was identified. Commercial glass ionomer cement (Fuji IX GP((R)) ) was the control and base material. Eight weight percent of hydroxyapatite was added into the glass ionomer powder. Specimens were fabricated and the fracture toughness, shear bond strength and eluted fluoride ion concentration were measured. Adding hydroxyapatite into the glass ionomer cement led to significantly higher fracture toughness after 15min and 24h from mixing. The hydroxyapatite-added cement also exhibited bond strength to dentin similar to that of the control from 15min to 56 days and consistent fluoride release for 13 weeks. SEM findings showed a cohesive type of fracture in the material for all specimens in both groups. These results indicate that hydroxyapatite-added glass ionomer cement has a potential as a reliable restorative material with improved fracture toughness, long-term bonding to dentin and unimpeded ability of sustained fluoride release.

Treatment with anti-CD86 costimulatory molecule prevents the autoimmune lesions in murine Sjögren's syndrome (SS) through up-regulated Th2 response.

Intraperitoneal administration with anti‐CD86 (B7.2) MoAb into the murine model for primary SS in NFS/sld mutant mice resulted in dramatically inhibitory effects on the development of autoimmune lesions, while no significant effects were observed when the mice were administered with anti‐CD80 (B7.1) MoAb. We found that spleen cells in the murine SS model treated with anti‐CD86 MoAb showed a significant impairment of autoantigen‐specific T cell proliferation. T cell activation markers (CD44high, CD45RBlow, Mel‐14low) were significantly down‐regulated in the spleen cells gated on CD4 in anti‐CD86‐treated mice. We detected a higher level of cytokine production of IL‐4 from splenic T cells in anti‐CD86‐treated mice, but not of IL‐2, and interferon‐gamma (IFN‐γ), compared with those in the anti‐CD80‐ and PBS‐treated SS model. Moreover, serum autoantibody production against α‐fodrin autoantigen was almost entirely suppressed in anti‐CD86‐treated mice. These data provide strong evidence that in autoimmune exocrinopathy resembling SS in NFS/sld mutant mice, the CD86 costimulatory molecule plays a crucial role in the initiation and subsequent progression of Th1‐mediated autoimmunity in the salivary and lacrimal glands.

Autoantigen-Specific CD4+CD28low T Cell Subset Prevents Autoimmune Exocrinopathy in Murine Sjögren’s Syndrome

Organ-specific autoimmune exocrinopathy resembling Sjögren’s syndrome (SS) that spontaneously develops in NFS/sld mutant mice thymectomized 3 day after birth is dependent on Th1-type CD4+ T cells. We previously reported that a cleavage product of 120-kDa α-fodrin may be an important autoantigen in the pathogenesis of SS in both an animal model and the patients. We demonstrate that in an animal model of SS with overt exocrinopathy, a unique CD4+ T cell subset expressing CD28low is dramatically increased in spleen cells before the disease onset, but that the CD4+ T cells of diseased mice were virtually all CD28high. We found that the spleen cells in these mice before the disease onset showed a significant increase in autoantigen-specific T cell proliferation. Analysis of in vitro cytokine production by spleen cells indicated, before the disease onset, severely impaired production of IL-2 and IFN-γ in the animal model, whereas high levels of IL-4 were observed. Expression of cytokine genes, including IL-4, IL-10, and TGF-β, was detected in FACS-sorted CD4+CD28low T cells by RT-PCR analysis. Transfer of CD4+CD28low T cells into the animal model actually prevented the development of autoimmune lesions including autoantibody production. These results suggest that a CD4+CD28low T cell subset that is continuously activated by an organ-specific autoantigen may play a regulatory role in the development of organ-specific autoimmune disease in an animal model of SS.

Mixed dentition space analysis for Indonesian Javanese children

Abstract The purposes of this study were to determine the applicability of Moyers and Tanaka-Johnston prediction methods for Indonesian Javanese children, and to develop new regression equations for predicting the size of the canine-premolar segment based on the normative standard of mesio-distal crown diameters of the permanent teeth in Indonesian children. Two hundred and eighty five sets of dental casts of the permanent dentition were obtained from Indonesian Javanese children in Yogyakarta, Indonesia during 2000– 2001. There were 143 males and 142 females aged 11.1 to 14.9years. The mesio-distal crown diameters were measured with calipers to an accuracy of 0.05mm. The statistical analyses were performed using computer software (SPSS 9.0 for Windows). This study confirmed that the use of Moyers and Tanaka-Johnston prediction methods for mixed dentition analysis among Indonesian Javanese children were unsuitable. Both methods underestimated the size of canine-premolar segments, with exception of the Tanaka-Johnston method in females. The combination of maxillary first molars and mandibular lateral incisors () showed relatively higher correlation with the actual size of ∑3 4 5. The development of new linear regression equations with predictor for predicting the size of the canine-premolar segment was based on the normative standard of mesio-distal crown diameters of permanent teeth in Indonesian Javanese children. The newly developed regression equations are more accurate than the regression equation that uses predictor for mixed dentition analysis among Indonesian Javanese.

Effects of sialagogues on the syntheses of polyamines and DNA in murine parotid gland

When rat parotid explants were cultured on siliconized lens paper floating on chemically defined 199 medium, all of sialagogues tested increased ornithine decarboxylase activity, which was roughly proportional to the amylase released into the culture medium. S-Adenosylmethionine decarboxylase and DNA synthesis were also induced by isoproterenol, methoxamine, carbachol and pilocarpine, but not by serotonin or substance P. The increases of the two decarboxylase activities and DNA synthesis were observed in vivo in mouse parotid gland after repeated injections of carbachol or pilocarpine. These results indicate that both adrenergic and cholinergic sialagogues stimulate the syntheses of polyamines and DNA in murine parotid gland.

Metaphyseal dysplasia of Braun–Tinschert type: Report of a Japanese girl

We report on a 7‐year‐old Japanese girl with metaphyseal dysplasia (MD) of Braun–Tinschert type, a recently recognized, autosomal dominant sclerosing bone dysplasia. All individuals with the disorder from four families in the literature originated from a small town in Bohemia or its vicinity. The occurrence of the disorder in a Japanese girl indicates that it is not restricted to Germans. The radiographic hallmarks of the disorder include metaphyseal undermodeling (Erlenmeyer‐flask deformity); osteosclerosis of the chondroosseous junctions, metaphyseal cortices, and epiphyseal margins; and exostosis‐like bone excrescences at the metaphyseal‐diaphyseal junctions. In the girl we described, the latter two findings were conspicuous at age 4 years, but became less prominent with increasing age. The metaphyseal trabeculae were somewhat coarse. The humeri exhibited varus deformity, and the ulnae and fibulae mild bowing. The mean bone mineral density of the lumbar spine was lower than that of age‐matched controls. The patient exhibited premature loss of primary teeth, likely to be a sign of increased periodontal bone resorption. Markers of bone formation and resorption were both increased, an indication of a high rate of bone turnover.

Complete infraocclusion of a previously erupted primary molar: A case report

Abstract The prevalence of infraoccluded or impacted primary molars was reported to be from 1.3% to 8.9% of the population with higher incidence between siblings. This is a report of a rare case of a 10-year-and-11-month-old boy with a previously erupted primary maxillary right second molar that was restored by with an amalgam filling at about three years of age. After seven years, the said tooth was found X-ray photographically to be completely embedded into the alveolar bone with an “impacted” maxillary permanent second premolar. There was also mesial tipping of the adjacent permanent first molar. The management of this case included the use of a space regainer to correct the molar tipping, surgical removal of the ankylotic infraoccluded primary molar and the use of a palatal holding arch to correct the torsiversion. This report underscores the need for early recognition of infraoccluded/ ankylosed primary teeth by dentists for regular monitoring and timely and appropriate intervention.

Sialagogue-stimulated protein phosphorylation related to ornithine decarboxylase induction in cultured rat parotid explants

Both beta-adrenergic (isoproterenol) and cholinergic (carbachol) sialagogues increase amylase secretion, ornithine decarboxylase activity and DNA synthesis in murine parotid gland in vivo and in vitro. These agonists enhanced the incorporation of labelled inorganic orthophosphate into parotid proteins in rat parotid explants cultured on siliconized lens paper floating on serum-free 199 medium. Analysis of the labelled proteins by SDS-PAGE and autoradiography revealed that isoproterenol enhanced the phosphorylation of four proteins with apparent molecular weights of 17, 20, 31 and 32 kDa and carbachol stimulated the phosphorylation of 31 and 32 K proteins. Isoproterenol-dependent ornithine decarboxylase induction and phosphorylation of the proteins were selectively suppressed by monensin but not by polymyxin B, whereas carbachol-dependent ornithine decarboxylase induction and protein phosphorylation were inhibited by polymyxin B but not by monensin. Neither monensin nor polymyxin B suppressed isoproterenol- or carbachol-stimulated amylase secretion. Time course experiments showed that sialagogue-stimulated protein phosphorylation preceded the increase of ornithine decarboxylase activity and had almost disappeared when it was maximal. Propranolol and atropine, antagonists of isoproterenol and carbachol, respectively, completely inhibited not only amylase secretion and ornithine decarboxylase induction but also protein phosphorylation stimulated by the corresponding agonists. These findings suggest that increased phosphorylation of specific proteins is associated with sialagogue-stimulated ornithine decarboxylase induction but not amylase secretion.