Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ODONTOBLASTS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed1988

Ultrastructural duality of extracellular fibrillar components of the odontoblast layer in the mouse molar.

The application of detergent solutions to dissociated molar dental papillae of mice permitted precise observation of the extracellular fibrillar material in the odontoblast layer and the predentine. Two types of fibrils were identified: cross-banded fibrils of variable diameter (25-200 nm) and aperiodic microfibrils of regular diameter (12.5 nm) and undetermined length. If the collagenic nature of the cross-banded fibrils is evident, the composition of the aperiodic microfibrils is probably different.

Animals↗
PubMed1989

Stimulatory effect of transferrin on the proliferation of embryonic mouse molar pre-odontoblasts and pre-ameloblasts in organ culture.

The effects of transferrin on the proliferation kinetics of these cells from day-14 lower first molars, cultured for 2-6 days in a chemically defined medium supplemented with 5 and 50 micrograms/ml of human diferric transferrin, were studied. Transferrin stimulated the mitotic and [3H]-thymidine labelling indices. These data were correlated with immunolocalization of the transferrin receptor using indirect immunofluorescence and specific monoclonal antibodies. The presence of specific transferrin receptors in pre-odontoblasts and pre-ameloblasts, and in ameloblasts of older teeth (day-18 to day-21), was also assessed by indirect immunofluorescence and binding experiments using iodinated transferrin.

Ameloblasts↗
PubMed1989

Differentiation of odontoblasts in grafted recombinants of murine epithelial root sheath and dental mesenchyme.

The epithelial root sheath (ERS) was isolated from first molars of 5-day-old post-natal CD-1 mice using trypsin. After isolation, ERS cells remained viable in vitro and immunohistochemical examination of cultures confirmed the epithelial phenotype and the absence of mesenchymal contamination. Recombinants of isolated ERS and dental papilla resulted in odontoblast differentiation within cells of the dental papilla, and the formation of root-like fragments of dentine after 2 weeks of intra-ocular grafting. These findings indicate the inductive influence of the ERS on dental papilla cells.

Animals↗
PubMed1991

Odontoblast-like cytodifferentiation of human dental pulp cells in vitro in the presence of a calcium hydroxide-containing cement.

The cement produced microcrystals of calcite by reaction with culture medium supplemented with calf serum. Human dental pulp cells seeded on such a substrate preferentially adhered and aggregated around the microcrystals. Immunofluorescence and immunogold labelling revealed a high affinity of serum fibronectin molecules for the calcite crystals. At 4 weeks in culture, the cells had various features of differentiated odontoblasts, notably nuclear polarization, typical appearance of the Golgi apparatus, synthesis of type I collagen and absence of type III, and apical accumulation of actin and vimentin. These cells also elaborated a collagenous extracellular matrix which did not mineralize.

Adolescent↗
PubMed1993

Absence of interaction between the 165-kDa fibronectin-binding protein involved in mouse odontoblast differentiation and vinculin.

Previous data suggested that matrix could control the organization of microfilaments in differentiating odontoblasts and that this process involved a complex of fibronectin-165-kDa membrane protein-vinculin. The use of two different gel systems and microsequence analysis demonstrated that two distinct 165-kDa proteins interact, one with fibronectin and the other with vinculin.

Actin Cytoskeleton↗
PubMed1985

Collagenase synthesis in clonal rabbit odontoblast-like cells (RP cells).

Post-confluent cultures of cloned rabbit odontoblast-like cells (RP: Rabbit Pulp cells) produced latent collagenase, which was isolated from serum-containing culture media by heparin-Sepharose affinity chromatography. RP collagenase was purified 4,420-fold from serum-containing medium to a specific activity of 1,313 units/mg with a yield of 14% by heparin-Sepharose affinity chromatography, carboxymethyl-cellulose ion-exchange chromatography, and by immunoadsorption chromatography. The RP cell culture appears to be a suitable model to use for studying collagenase synthesis in mineralized tissue-forming cells and for elucidating the mechanism of collagen degradation in pulp tissue and dentin matrix.

Animals↗
PubMed1977

Focal odontoblastic dysplasia: dentin dysplasia type III?

A new, nonsyndromic dentin defect, focal odontoblastic dysplasia, is described on the basis of clinical, radiographic, histologic, and scanning electron microscopic criteria. A provisional classification is proposed for this disease entity according to the nosology of Shields and associates. Four additional cases in the literature which possibly represent this new entity are presented, and a possible genetic etiology is discussed.

Adult↗
PubMed1986

A study of the odontoblast process with transmission electron microscopy.

Freshly extracted human third molars with completely formed roots were sectioned and placed in Karnovsky's fixative. The specimens were decalcified in ethylenediaminetetraacetic acid (EDTA) for 91 days, followed by digestion in collagenase. They were then fixed in a solution of buffered osmium tetroxide or ruthenium red and buffered osmium tetroxide, embedded in Spurr's plastic mixture, and sectioned for transmission electron microscopy. Each section was stained with uranyl acetate and lead citrate and viewed with a transmission electron microscope. No odontoblast processes could be identified at the cemental third of the dentin with the described technique.

Adult↗
PubMed2004

Transgenic mice expressing a ligand-inducible cre recombinase in osteoblasts and odontoblasts: a new tool to examine physiology and disease of postnatal bone and tooth.

The skeleton supports body structures in vertebrates and helps maintain calcium homeostasis throughout life. Disruption of genes involved in mammalian bone formation has often led to embryonic lethality, hence preventing study of these genes' role in adult animals. To develop a usable tool for such study, we generated transgenic mice in which a 2.3-kb mouse Col1a1 proximal promoter, which is active in all osteoblasts, drives a transgene coding for a polypeptide consisting of Cre recombinase fused to a mutated ligand-binding domain of the estrogen receptor. In this Col1a1-CreERT2 mouse line, expression patterns of the transgene and of the resulting Cre-mediated DNA recombination are analyzed by crossing with ROSA26 reporter mice and by measurement of beta-galactosidase activity and X-gal staining. Exposure to 4-hydroxytamoxifen induced Cre-mediated recombination in osteoblasts in virtually all bones and in odontoblasts in teeth of both embryos and postnatal mice. The generation of these transgenic mice provides a new and important tool with which to study the function of specific genes in bone and tooth physiology and diseases in intact animals after birth.

Animals↗
PubMed1983

The biosynthesis of dentine gamma-carboxyglutamic acid-containing proteins by rat incisor odontoblasts in organ culture.

Rat odontoblasts were shown to synthesize and secrete gamma-carboxyglutamic acid(Gla)-containing proteins into dentine after organ culture in the presence of radiolabelled amino acid precursors. Purified dentine Gla-containing protein from rat incisors was used as antigen to prepare rabbit antisera as a probe of dentine Gla-containing-protein biosynthesis in organ cultures of dentine (rat incisor) and bone (rat calvaria). Use of the antiserum also pointed out the cross-reactivity of a high-M, glycoprotein present within the dentine matrix. The present results are significant in identifying dentine gla-containing protein as endogenous to mineralizing dentine and may relate to the commonality between calcifying connective tissues in general.

1-Carboxyglutamic Acid↗
PubMed2002

Two- versus three-dimensional in vitro differentiation of human pulp cells into odontoblastic cells.

The spatial organization of the pulp cells may modify the cytodifferentiation process. The purpose of this study was to compare the two- versus three-dimensional cell culture systems for differentiation of human odontoblastic cells in vitro. Pulpal cores from freshly extracted human third molars were cultured in vitro in a perfusion device on two types of membranes: polyester membrane (two-dimensional [2D] cell culture) and nylon mesh (three-dimensional [3D] cell culture). The cells were incubated with minimum essential medium containing (a) substitute serum, (b) 10% fetal calf serum (FCS), (c) 10% fetal calf serum + 2 mM beta-glycerophosphate (beta GP), and (d) 10% fetal calf serum + transforming growth factor (TGF) beta 1. Immunohistochemistry was used to evaluate the expression of collagen I, osteonectin, and nestin. Small differences were observed between 2D and 3D cell culture systems. This was particularly evident in the 10% FCS group. beta-Glycerophosphate in the 3D system seems to stimulate the osteogenic cell phenotype, as a considerable induction of osteonectin is observed.

Adolescent↗
PubMed2003

Direct capping with four different materials in humans: histological analysis of odontoblast activity.

Pulp inflammation in restored teeth is mainly due to the presence of bacteria or bacterial products introduced by microleakage around the restoration or to the material toxicity. Recent knowledge has permitted a precise identification of the risks for pulpal irritation associated with adhesive materials and procedures. The purpose of this work was to evaluate the cellular events that occur in direct pulp exposure capped using different materials. Twenty-four vital teeth without caries, scheduled for extraction for orthodontic reasons, were selected. After a control of the hemostasis, each pulp was directly capped with a different material. The samples were randomly divided into four groups of six specimens each: group I: dental-bonding agent (Solist) followed by resin composite (Ecusit); group II: dental adhesive (Prompt) and resin composite (Pertac II); group III: traditional calcium hydroxide (Dycal) plus resin composite (Ecusit); group IV: light-curing calcium hydroxide (Ultrablend Plus) and amalgam (Dentsply). After 15 days the teeth were extracted, immediately fixed in 10% buffered formalin, embedded in resin (7200 Technovit), and prepared for thin ground sections with Precise 1 System. In the specimens of all groups, there were active odontoblasts near the composite resins and no newly formed dentin. Small quantities of inflammatory cells were present. A 1- to 3-microm layer zone of necrosis was present. In conclusion, all materials tested in this study induced similar tissue responses.

Analysis of Variance↗
PubMed1976

Cell division and cytodifferentiation of odontoblasts.

The chronological delay of overt cytodifferentiation of odontoblasts in isochronal and heterochronal associations between inner dental epithelium and preameloblasts was analysed. The in vitro action of FUdR of tooth germs was summarised. The respective role of cell interaction and specific cell cycle was discussed.

Animals↗
PubMed1982

Immunofluorescent localization of vimentin, prekeratin and actin during odontoblast and ameloblast differentiation.

The localization of constitutive proteins of different types of cytoskeletal components (prekeratin, vimentin, and actin) was examined in embryonic mouse molars using specific antibodies and immunofluorescence microscopy on frozen sections. Prekeratin and actin were found in the enamel organ. Preameloblasts demonstrated uniform staining, whereas ameloblasts demonstrated an apical accumulation of both prekeratin and actin. Vimentin and actin were observed in the dental papilla. A redistribution of vimentin accompanied the polarization of odontoblasts. A possible transmembranous control of cytoskeletal activities by the extracellular matrix is discussed.

Actins↗
PubMed1977

Odontoblast metabolism in rats deficient in vitamin D and calcium. II. Changes in activities of alkaline phosphatases.

Rats were fed a low calcium diet deficient in vitamin D for 14 days. Changes in alkaline phosphatase activities in odontoblasts dissected out from incisor teeth were studied biochemically. A strong increase in pNPP-ase, PPi-ase, total ATP-degradation and Ca2+- ATPase was observed in the deficient animals compared with animals fed a control diet.

Adenosine Triphosphatases↗
PubMed1988

A probable common disturbance in the early stage of odontoblast differentiation in Dentinogenesis imperfecta type I and type II.

Deciduous teeth from 7 patients with dentinogenesis imperfecta (DI) Type I and Type II were examined by conventional microscopy. A defective layer was found which runs parallel with the dentinal surface in the outer portion of dentin in teeth of both types. Dentinal tubules were interrupted in the vicinity of this layer. When the ground sections were examined after being stained by the phosphophoryn staining method, the DI Type I dentin was found to contain phosphophoryn at the same low level as the DI Type II dentin, suggesting similar deficiency in phosphophoryn concentration. These results suggest that both types of DI have a common primary disturbance in the early stage of odontoblast differentiation.

Cell Differentiation↗
PubMed1975

Determination of inorganic pyrophosphatase in rat odontoblast layer by a radiochemical method.

The enzyme inorganic pyrophosphatase (PPiase, EC 3.6.1.1) from the odontoblastic layer of rat incisors has been studied by means of a radiochemical micromethod. The enzyme was incubated with 32P-pyrophosphate in tris-HCl buffer at 37 degrees C. The reaction was linear with time for at least 45 min, and the pH optimum was found to be 8.8, independent of the amount of pyrophosphate present. Heating the enzyme at 56 degrees C inhibited the enzyme activity rapidly, Mg2+ ions activated the enzyme by 15% at an ion concentration of 4 mM, while higher concentrations were inhibitory. Ca2+ ions and PO43-ions inhibited the enzyme at all concentrations. F- ions did not affect the PPiase at concentrations below 8 mM, whereas higher concentrations had an inhibiting effect. Urea was found to inhibit the enzyme at concentrations above 1.5 M, while EDTA was a strong inhibitor at very low concentrations. The characteristics of PPiase agree well with the properties of the enzyme nonspecific alkaline phosphatase (EC 3.1.3.1.) studied earlier.

Animals↗