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 397 records · Page 22Linked to original sources
PubMed2003

A comparison of the anatomical structure of odontoblasts and the connective tissue fibres in relation to the age of the patient.

The aim of this work was to study the structure of dental pulp (mainly the connective tissue fibre and odontoblasts) during the active production of dentine in relation to the age of the patient. The pulps of the teeth extracted for orthodontic reasons from a population of 10-50 year-olds were investigated with the help of a transmission electron microscope (TEM) and a scanning electron microscope (SEM). Condensation of the small collagen fibres and fibrils around the morphotic elements of the dental pulp were found more often in the elderly patients.

Adolescent↗
PubMed1992

Odontoblast-mediated regulation of the progression of dentinal caries.

Osteoblasts and odontoblasts are both derived from the same mesenchymal cell line. Our aim was to investigate whether the processes of bone destruction and dentinal caries are biologically similar. The working hypothesis was that after the initiation of caries in the enamel, its rate of progression in the dentine is regulated by cell-mediated factors. Experimental caries was induced in the rat with a high sucrose diet combined with Streptococcus sobrinus infection. Both destruction of dentine and its apposition in the pulp under the carious lesions were measured after vital staining with tetracycline. Caries progression and dentine apposition were higher in developing teeth prior to apex "closure" than in adult, fully-formed teeth. Rats placed on a cariogenic diet during tooth development had an increased rate of caries progression. Fluoride administration via the drinking water was associated with decreased dentine apposition and little progression of dentine caries during the developmental stages. Dentine apposition was enhanced in adult rats placed on fluoride administration, while caries progression was reduced, whereas in animals subjected to metabolic acidosis dentine caries progression was enhanced, with reduced dentine apposition. In contrast, alkalotic animals had less dentinal lesions and smaller ones than the controls. Three theories are advanced to explain the observed changes: (i) They may be associated with changes in alkaline phosphatase activity in the pulpo-dentinal complex, (ii) they may be mediated by ionic changes in the dentinal fluid, or (iii) they may reflect the liberation of growth factors from dentinal matrix.

Acidosis↗
PubMed2005

[Role of Smad signaling in transcription of Smad7 gene mediated by TGF-beta1 in odontoblast cell line MDPC-23].

PURPOSE: To investigate the role of Smad signaling in transcription of Smad7 gene mediated by TGF-beta1 in odontoblast cell line MDPC-23, and to explore the molecular mechanism of Smad7 gene expression mediated by TGF-beta1 at the transcriptional level. METHODS: Smad function and its role in transcription of Smad7 were investigated in cotransfection experiments using Smad7 promoter-luciferase reporter construct containing the sequence between -408 bp and +112 bp of mouse Smad7 gene. The data were analysed by one-way ANOVA. RESULTS: When the Smad7 promoter-luciferase reporter gene construct was expressed in MDPC-23 cells, its transcriptional activity was significantly induced by TGF-beta1 treatment, whereas not by BMP-2 treatment. Overexpression of Smad1, 2, 4, or 5 had no effect on transcriptional activity of Smad7 promoter. Overexpression of Smad3 markedly promoted transcriptional activity of Smad7 promoter, whereas co-transfection of Smad3 and Smad4 doubled the effect of Smad3. Overexpression of Smad3 dominant negative mutant or Smad3 antisense cDNA (AS-Smad3) significantly inhibited transcriptional activity of Smad7 promoter induced by TGF-beta1. CONCLUSION: TGF-beta1 regulated transcription of Smad7 gene through association of Smad3 and Smad4 in MDPC-23 cells.

Animals↗
PubMed2004

A primary culture system for human odontoblasts.

Caries is one of the most prevalent of all human diseases. In recent years there has been a growing recognition that healing or remineralization protocols for the treatment of carious lesions in dentine are possible, rather than just relying on surgical removal of the diseased tissue and placement of restorative materials. This project proposes to investigate a strategy for deliberately stimulating cellular reparative processes for the treatment of this disease. In order to do this, it is necessary to develop a cell culture system to develop and characterize the mineralizing cells (odontoblast like) from human dental explants.

Cell Culture Techniques↗
PubMed1990

Annexins I-VI in secretory ameloblasts and odontoblasts of rat incisor.

Immunoblot analyses and ultrastructural immunogold studies have been conducted on annexins in the secretory ameloblasts and odontoblasts of the rat incisor. Annexins I and II were seen in the soluble and particulate fractions of the enamel-related portion but not in the dentin-related portion. These proteins were visualized in the cytosol, near to the plasma membrane of Tomes' processes and in secretory vesicles in the ameloblasts. The forming enamel was also labeled. Annexins III, VI an V were detected in both the soluble and particulate fractions of the enamel-and dentin-related portions. Annexin IV was mainly localized in the proximal and distal areas of the secretory ameloblasts and virtually absent from in the supranuclear area. Annexin V was mainly detected in the cytosol of the cells and to a lesser extent near the plasma membrane. Annexin VI was mainly detected in the particulate fraction of enamel- and dentin-related portions. It was seen in the mitochondria and in the subplasmalemmal undercoat. All these proteins may play a role in exocytosis and endocytosis. They are implied in the regulation of cell calcium, but not in the transfer of calcium through the cells in the direction of the forming enamel and dentin, except annexins I and II since they are both present in the secretory vesicles and in the forming enamel.

Ameloblasts↗
PubMed1989

Visualization of predentine matrix components and endocytic structures in rat incisor odontoblasts with tannic acid.

Rat incisor odontoblasts and predentine fixed with tannic acid-glutaraldehyde-osmium tetroxide (Tago) were compared with those obtained by prior incubation in tannic acid-Ringer before conventional fixation with glutaraldehyde-osmium-tetroxide (Tari) The Tago method allowed visualization of complex glycoconjugates along the plasma membrane, in the pericellular spaces and in the intercellular predentine matrix. The non-collagenous proteins, proteoglycans and lipids were seen as granules and thin filaments located between the collagen fibers and at their surface. The collagen fibers themselves were also stained. The Tari method which was used to visualize exocytosis, mainly revealed endocytosis in the form of large intracellular vacuoles containing tannic acid and stained proteoglycans. It is suggested that tannic acid-Ringer incubation prior to fixation increases the endocytosis of the matrix components, which acculumates in these large vesicles.

Animals↗
PubMed1982

Dentin sensitivity, odontoblasts and nerves under desiccated or infected experimental cavities. A clinical, light microscopic and ultrastructural investigation.

Cavities were prepared in 35 pairs of young human premolars. One tooth in each pair served as a control. In one Series the test cavity was desiccated with compressed air for one minute. LM and TEM examination of the dentin and the adjacent pulp revealed an extensive aspiration of odontoblasts. Nerve fibers had moved 0.1 to 0.2 mm outward in the tubules. It is suggested that a streching or disruption of the nerve had occurred during desiccation. In a second Series, the test cavity was infected for 1 to 2 weeks. No nerve fibers were seen in the dentinal tubules under the cavities, only cellular remnants and some microorganisms. Despite the absence of nerves the dentin in the bottom of the infected cavities was highly sensitive to stimulation. It was concluded that the nociceptive nerves present in the adjacent inflamed pulp may be terminals, mechanosensitive in nature and that they activated by rapid outward movements of the tubules fluid.

Dental Pulp↗
PubMed1982

Electron microscopic study on the effects of vinblastine on young odontoblasts in rat incisor.

Young Wistar male rats were injected intravenously with 2 mg/kg of vinblastine sulfate. After three, six, 12, 24 and 48 hours, the upper incisors were dissected out of the animals, and their young odontoblasts were observed in an electron microscope. Three to six hours after the injection, the regular polarity of the nuclei and the cytoplasmic organelles were dramatically changed following a decrease in the number of microtubules. Disturbance in protein synthesis was suggested at this stage by unusual shapes and the arrangement of the rough endoplasmic reticulum and loss of the polysomal arrangement of the ribosomes attached to the reticulum. After more than 12 hours, accumulation of secretion granules and the occurrence of bodies, containing a few strands of collagen-like fibrils, were frequently seen in various portions of the cells, indicating retarded export of the secretion substance. Occurrence of a number of unusually short fibrils in predentin was another prominent feature noticed in later stages. The fibrils were about 3000A long by 2000A or 600A wide, and many of the 2000A wide fibrils were characterized by a banded structure which resembled the previously reported SLS collagen. The 600A wide fibrils were usually banded with about 600A periodicity.

Animals↗
PubMed1995

Ameloblasts and odontoblasts, target-cells for 1,25-dihydroxyvitamin D3: a review.

The basic features on the vitamin D endocrine system, synthesis of the main metabolite 1,25-dihydroxyvitamin D3 (1,25) and its genomic action mediated via the vitamin D receptor (VDR), are reviewed. Calbindin-D9k, calbindin-D28k and osteocalcin are presented as the most-extensively investigated vitamin D-dependent calcium-binding proteins. The action of 1,25 on the basic process of proliferation and differentiation is introduced. Then, the basis of the systemic theory of vitamin D action on teeth (clinical and experimental data and the dissimilar distribution of VDR and of potential vitamin D-dependent proteins in dental cells) are exposed. Finally, the data obtained with calbindin-D9k, calbindin-D28k, osteocalcin and VDR, which supports the theory that ameloblasts and odontoblasts are target-cells for 1,25 is presented. As a perspective, a cross-survey of the 1,25 and tooth-related literature is proposed which may indicate potential target-genes for 1,25 in teeth as done previously for calbindins-D.

Ameloblasts↗
PubMed1980

Non-myelinated nerve fibres and their terminals in the sub-odontoblastic plexus of the feline dental pulp.

Serial thin sections of the coronal dental pulp of the cat's canine tooth were cut. Parts of the sub-odontoblastic neural plexus were photographed from 100 of the sections. The plexus consists of many slender, predominantly unmyelinated nerve fibres. Many axons are incompletely sheathed by their Schwann cell. Some axons leave the Schwann cell sheath and either end in the extracellar space or return to the Schwann cell after traveling a short distance. Several axons are often seen in close contact within a single invagination of the Schwann cell. They remain in contact for up to 7 micrometer.l Both Schwann cells and axons are see to branch in this region. These features may be characteristic of nerve fibres and terminals which respond to noxious stimuli.

Animals↗