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Journal ArticleDOI

Fluoride directly stimulates proliferation and alkaline phosphatase activity of bone-forming cells.

21 Oct 1983-Science (American Association for the Advancement of Science)-Vol. 222, Iss: 4621, pp 330-332
TL;DR: Treatment with sodium fluoride increased proliferation and alkaline phosphatase activity of bone cells in vitro and increasedBone formation in embryonic calvaria at concentrations that stimulate bone formation in vivo.
Abstract: Fluoride is one of the most potent but least well understood stimulators of bone formation in vivo. Bone formation was shown to arise from direct effects on bone cells. Treatment with sodium fluoride increased proliferation and alkaline phosphatase activity of bone cells in vitro and increased bone formation in embryonic calvaria at concentrations that stimulate bone formation in vivo.
Citations
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Journal ArticleDOI
TL;DR: It is now most likely that enamel hypomineralization in fluorotic teeth is due predominantly to the aberrant effects of excess fluoride on the rates at which matrix proteins break down and/or the rate at which the by-products from this degradation are withdrawn from the maturing enamel.
Abstract: This review aims at discussing the pathogenesis of enamel fluorosis in relation to a putative linkage among ameloblastic activities, secreted enamel matrix proteins and multiple proteases, growing enamel crystals, and fluid composition, including calcium and fluoride ions. Fluoride is the most important caries-preventive agent in dentistry. In the last two decades, increasing fluoride exposure in various forms and vehicles is most likely the explanation for an increase in the prevalence of mild-to-moderate forms of dental fluorosis in many communities, not the least in those in which controlled water fluoridation has been established. The effects of fluoride on enamel formation causing dental fluorosis in man are cumulative, rather than requiring a specific threshold dose, depending on the total fluoride intake from all sources and the duration of fluoride exposure. Enamel mineralization is highly sensitive to free fluoride ions, which uniquely promote the hydrolysis of acidic precursors such as octacalcium phosphate and precipitation of fluoridated apatite crystals. Once fluoride is incorporated into enamel crystals, the ion likely affects the subsequent mineralization process by reducing the solubility of the mineral and thereby modulating the ionic composition in the fluid surrounding the mineral. In the light of evidence obtained in human and animal studies, it is now most likely that enamel hypomineralization in fluorotic teeth is due predominantly to the aberrant effects of excess fluoride on the rates at which matrix proteins break down and/or the rates at which the by-products from this degradation are withdrawn from the maturing enamel. Any interference with enamel matrix removal could yield retarding effects on the accompanying crystal growth through the maturation stages, resulting in different magnitudes of enamel porosity at the time of tooth eruption. Currently, there is no direct proof that fluoride at micromolar levels affects proliferation and differentiation of enamel organ cells. Fluoride does not seem to affect the production and secretion of enamel matrix proteins and proteases within the dose range causing dental fluorosis in man. Most likely, the fluoride uptake interferes, indirectly, with the protease activities by decreasing free Ca(2+) concentration in the mineralizing milieu. The Ca(2+)-mediated regulation of protease activities is consistent with the in situ observations that (a) enzymatic cleavages of the amelogenins take place only at slow rates through the secretory phase with the limited calcium transport and that, (b) under normal amelogenesis, the amelogenin degradation appears to be accelerated during the transitional and early maturation stages with the increased calcium transport. Since the predominant cariostatic effect of fluoride is not due to its uptake by the enamel during tooth development, it is possible to obtain extensive caries reduction without a concomitant risk of dental fluorosis. Further efforts and research are needed to settle the currently uncertain issues, e.g., the incidence, prevalence, and causes of dental or skeletal fluorosis in relation to all sources of fluoride and the appropriate dose levels and timing of fluoride exposure for prevention and control of dental fluorosis and caries.

406 citations

Journal ArticleDOI
28 Oct 2010-ACS Nano
TL;DR: Investigation of the cellular effects of gold nanoparticles (AuNPs) on the differentiation of mesenchymal stem cells (MSCs) and the associated molecular mechanisms showed that AuNPs promoted the differentiate of MSCs toward osteoblast cells over adipocyte cells by inducing an enhanced osteogenic transcriptional profile and an attenuated adipogenic transcriptionAL profile.
Abstract: Understanding the interaction mechanisms between nanomaterials and biological cells is important for the control and manipulation of these interactions for biomedical applications. In this study, we investigated the cellular effects of gold nanoparticles (AuNPs) on the differentiation of mesenchymal stem cells (MSCs) and the associated molecular mechanisms. The results showed that AuNPs promoted the differentiation of MSCs toward osteoblast cells over adipocyte cells by inducing an enhanced osteogenic transcriptional profile and an attenuated adipogenic transcriptional profile. AuNPs exerted the effects by interacting with the cell membrane and binding with proteins in the cytoplasm, causing mechanical stress on the MSCs to activate p38 mitogen-activated protein kinase pathway (MAPK) signaling pathway, which regulates the expression of relevant genes to induce osteogenic differentiation and inhibit adipogenic differentiation.

362 citations


Cites methods from "Fluoride directly stimulates prolif..."

  • ...NaF (Sigma, USA), which can promote osteogenetic differentiation of MSCs, was used as a positive control and dispersed in -MEM.(59) After incubation, MSCs were washed twice with icecold D-Hank’s and lysed by two cycles of freezing and thaw....

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Journal ArticleDOI
TL;DR: This parallel in vitro and in vivo investigation demonstrates that fluoride ion modification enhanced osteoblastic differentiation and interfacial bone formation at endosseous titanium implants by parallel in vivo and in vitro investigations.

361 citations

Journal Article
TL;DR: Based on the biomechanical and histomorphometric data, the fluoride- modified titanium implants demonstrated a firmer bone anchorage than the unmodified titanium implants after a shorter healing time.
Abstract: Purpose: The purpose of the present study was to investigate whether a fluoride modification of the titanium surface would have an effect on bone response after implantation. Materials and Methods: Titanium-oxide–blasted titanium implants with and without fluoride modification were investigated in a rabbit tibia model. Quantitative analysis of surface roughness, biomechanical interlocking, and in vivo tissue reactions in rabbit bone at 1 and 3 months after placement were compared. Results: The fluoride-modified test implants had a slightly smoother surface (S a: 0.91 ± 0.14 µm) than the unmodified control implants (S a: 1.12 ± 0.24 µm). Significantly higher removal torque values (85 ± 16 Ncm vs 54 ± 12 Ncm) and shear strength between bone and implants (23 ± 9 N/mm2 vs 15 ± 5 N/mm 2 ) were measured for the fluoride-modified implants after 3 months. The histomorphometric evaluations demonstrated higher bone-to-implant contact for test implants at 1 month (35% ± 14% vs 26% ± 8%) and 3 months (39% ± 11% vs 31% ± 6%) after placement. Discussion: Implant surface modification with fluoride may result in morphologic and physiochemical phenomena that are of significance for the bone response. Another possible explanation for the findings in the present study is that a surface modification changes the surface chemical structures to be more suitable for bone bonding. Conclusion: Based on the biomechanical and histomorphometric data, the fluoride-modified titanium implants demonstrated a firmer bone anchorage than the unmodified titanium implants. These implants achieved greater bone integration than unmodified titanium implants after a shorter healing time. (More than 50 references.) INT J ORAL MAXILLOFAC IMPLANTS 2004;19:659‐666

314 citations

References
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Book
01 Jan 1979
TL;DR: In what case do you like reading so much? What about the type of the vitamin d the calcium homeostatic steroid hormone book? The needs to read? Well, everybody has their own reason why should read some books as discussed by the authors.
Abstract: In what case do you like reading so much? What about the type of the vitamin d the calcium homeostatic steroid hormone book? The needs to read? Well, everybody has their own reason why should read some books. Mostly, it will relate to their necessity to get knowledge from the book and want to read just to get entertainment. Novels, story book, and other entertaining books become so popular this day. Besides, the scientific books will also be the best reason to choose, especially for the students, teachers, doctors, businessman, and other professions who are fond of reading.

3,998 citations

Journal ArticleDOI
TL;DR: A simple and sensitive assay for adenosine 3':5'-cyclic monophosphate (cAMP) has been developed that is based on competition for protein binding of the nucleotide, presumably to a cAMP-dependent protein kinase.
Abstract: A simple and sensitive assay for adenosine 3′:5′-cyclic monophosphate (cAMP) has been developed that is based on competition for protein binding of the nucleotide, presumably to a cAMP-dependent protein kinase. The nucleotide-protein complex is adsorbed on a cellulose ester filter. Assay conditions are such that a binding constant approaching 10-9 M is obtained, and the assay is thus sensitive to 0.05-0.10 pmol of cAMP.

3,048 citations

Journal ArticleDOI
18 Sep 1981-Science
TL;DR: Marginal or severe trace element imbalances can be considered risk factors for several diseases of public health importance, but proof of cause and effect relationships will depend on a more complete understanding of basic mechanisms of action and on better analytical procedures and functional tests to determine marginal trace element status in man.
Abstract: Essential trace elements are required by man in amounts ranging from 50 micrograms to 18 milligrams per day. Acting as catalytic or structural components of larger molecules, they have specific functions and are indispensable for life. Research during the past quarter of a century has identified as essential six trace elements whose functions were previously unknown. In addition to the long-known deficiencies of iron and iodine, signs of deficiency for chromium, copper, zinc, and selenium have been identified in free-living populations. Four trace elements were proved to be essential for two or more animal species during the past decade alone. Marginal or severe trace element imbalances can be considered risk factors for several diseases of public health importance, but proof of cause and effect relationships will depend on a more complete understanding of basic mechanisms of action and on better analytical procedures and functional tests to determine marginal trace element status in man.

885 citations

Journal ArticleDOI
01 Feb 1980-JAMA
TL;DR: Until long-term safety and antifracture efficacy are better established, the sodium fluoride, calcium supplements, and vitamin D regimen should continue to be restricted to investigational use.
Abstract: Thirty-six patients with primary osteoporosis were treated for up to six years with sodium fluoride, calcium supplements, and, in 24 patients, vitamin D. Major adverse reactions (synovitis, painful plantar fascial syndrome, recurrent vomiting, or anemia) occurred in 15 patients (42%). New vertebral fractures occurred at a rate of 329 fractures per 1,000 years of observation. Almost half of them occurred during the first year of therapy, and they were only one sixth as frequent in 12 patients who had fluoride-induced increased trabeculation on vertebral roentgenograms. Nevertheless, until long-term safety and antifracture efficacy are better established, this regimen should continue to be restricted to investigational use. (JAMA243:446-449, 1980)

135 citations