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Bones and fractures
Published in Henry J. Woodford, Essential Geriatrics, 2022
Vitamin D is not a true vitamin because most of it is normally created within the skin by the action of ultraviolet light from the sun on 7-dehydroxycholesterol to form colecalciferol. The remainder comes from dietary intake (10–20%).1 If sunlight exposure is inadequate (NB reduced effect in people with darker skin or through sunscreen use) then intestinal absorption becomes more important. Dietary sources include oily fish, eggs, red meat, liver and some fortified foods (e.g. breakfast cereals and fat spreads). This precursor is then converted to 25-hydroxycolecalciferol (25OHD) in the liver. This is further hydroxylated, mainly in the kidney, to form 1,25-hydroxycolecalciferol (1,25(OH)2D, also known as ‘calcitriol'), which is the active form of vitamin D (maintained by rising PTH). The main actions of vitamin D are on the bowel and on bone. In the bowel it causes a rise in both calcium and phosphate absorption through increasing binding proteins in the intestinal epithelial cells. Its actions on bone enhance mineralisation.
Acute Kidney Injury and Chronic Kidney Disease
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Lynne Sykes, Ibrahim Ali, Philip A. Kalra
Osteomalacia is seen in conjunction with adynamic bone disease.Due to low 1,25(OH)2D3.Causes poor bone mineralisation.Systemic metabolic acidosis can also contribute.
Clinical Progresses in Regenerative Dentistry and Dental Tissue Engineering
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Regenerative dentistry: Making dentin—Dental clinicians know that no material is available today to mimic all the physical, mechanical and esthetic properties of enamel and dentin. Demineralized dentin powder also has an intrinsic capability to induce mineralization. When applied directly to areas of pulp exposure, demineralized dentin induces the local formation of mineralized tissues. An understanding of which components of dentin powder had the inductive capability began in the early 1990s when it was discovered that specific fraction of dentin, which presumably contained Bone Morphogenic Proteins (BMP) activity, induced reparative dentin formation (Trembley A 1744).
Umbilical cord N-terminal procollagen of type l collagen (P1NP) and beta C-terminal telopeptide (βCTX) levels in term pregnancies with vitamin D deficiency
Published in Gynecological Endocrinology, 2021
Mefkure Eraslan Sahin, Erdem Sahin, Yusuf Madendag, Ilknur Col Madendag, Cigdem Karakukcu, Gokhan Acmaz
We can explain our results with the direct effect of vitamin D on bone mineralization. Indirect effects occur via control of calcium and phosphate absorption in the intestine and renal reabsorption of calcium [23]. In the current study, the same corrected maternal serum calcium levels suggest the direct effect of vitamin D rather than the indirect effect. 1.25(OH)D3 directly effects on osteoblasts by enhancing differentiation and mineralization, which was shown in vitro cultures using human osteoblasts [24–27]. Osteoblasts express the vitamin D receptor for making possible these effects [28]. Additionally, osteoblasts express vitamin D binding protein receptors cubulin and megalin and also express1-alfa-hydroxylase metabolizing 1.25(OH)D3 which stimulates differentiation and mineralization [29–31]. 25(OH)D3 directly affects osteoblasts both for controlling the production of extracellular matrix proteins (collagen type I, osteopontin, osteocalcin, matrix Gla protein) and for supplying phosphate for the deposition of mineral on the activity of the alkaline phosphatase enzyme [26].
An analysis of third molar mineralization in Brazilian patients with cleft lip and palate
Published in Acta Odontologica Scandinavica, 2020
Esther Carneiro Ribeiro, Rosa Helena Wanderley Lacerda, Luciana Gabriella Medeiros da Silva, Bianca Marques Santiago, Camila Helena Machado da Costa, Manuella Santos Carneiro Almeida
In our study, the type of cleft impacted third molar development in cleft patients, but no significant differences were observed between the right and left sides, regardless of the presence or absence of cleft. On the other hand, maxillary third molars showed early development in relation to the mandible. In contrast, the study by Tan et al. [4] showed late mineralization of maxillary permanent teeth as compared to the mandible in Singaporean cleft children by Demirjian’s method, but only on the cleft side, with no differences between the arches for the non-cleft side. Here, the teeth most frequently showing developmental delays were the lateral incisors, followed by the central incisors near the cleft. Thus, it is suggested that the presence of cleft lip and palate may result in late mineralization of maxillary teeth that are close to the cleft when compared to the other teeth of the same individual. This may justify the lack of differences observed in our study in mineralization of third molars between the right and left sides, which were far from the cleft site.
Towards osteogenic differentiation of human dental pulp stem cells on PCL-PEG-PCL/zeolite nanofibrous scaffolds
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Mahdieh Alipour, Marziyeh Aghazadeh, Abolfazl Akbarzadeh, Zahra Vafajoo, Zahra Aghazadeh, Vahideh Raeisdasteh Hokmabad
Osteoblasts release a large amount of extracellular deposits on the surface of substrates. This process is known as mineralization which represents successful in vitro bone formation. The mineralization can be identified as reddish-black spots via Alizarin red S staining [31]. In order to assess the effect of zeolite on osteogenic differentiation of hDPSCs, Alizarin red S staining was performed on PCL-PEG-PCL nanofibers. Figure 4 displays the Alizarin red S staining activity of cells seeded on PCL-PEG-PCL, PCL-PEG-PCL/Zeolite nanofibers, with TCPs containing DMEM without nanofibers being used as a control. According to the results, compared to TCPs (control) and PCL-PEG-PCL nanofibers, hDPSCs seeded in PCL-PEG-PCL/Zeolite nanofibers presented a significantly higher degree of mineral deposition (p < .01), which was mainly associated with the establishment of an osteo-like phenotype. Our results presented that the addition of zeolite in PCL-PEG-PCL nanofibrous scaffolds had an important positive effect in simulating mineralization, making them appropriate candidates for bone tissue engineering.