Browsing by Subject "mineralization"

Now showing 1 - 6 of 6
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    Bone quality: Understanding what matters
    (2004) Burr, David B.
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    Differentiation and Activity of Murine Derived Stromal Osteoblasts After Electromagnetic Wave Stimulation
    (2022) Wu, Jennifer L.; Spolnik, Kenneth; Bruzzaniti, Angela; Ehrlich, Ygal; Warner, Ned
    Introduction: Elimination of bacteria and active infection within an infected root canal system is one of the primary objectives of nonsurgical root canal treatment. One of the measures of successful root canal treatment is subsequent bone healing of periapical lesions caused by previous infection. A previous study by Yumoto et al. showed that electromagnetic wave stimulation can increase proliferation of osteoblastic cells with no cytotoxicity, and it can also up-regulate growth factors such as vascular endothelial growth factor and platelet-derived growth factor.18 They also showed increased proliferation of an immortalized osteoblastic MC3T3-E1 cell line 3 days following electromagnetic stimulation (EMS).18 Previously, Pauly et al. found increased alkaline phosphatase (ALP) activity with 10 mA EMS application to primary murine calvaria-derived osteoblastic cells with 5 pulses at 1 second per pulse, but no significant differences were found for MTS proliferation nor mineral deposition compared to a negative control group.82 Optimization of the different variables including post-treatment incubation time, current delivery, and number of pulses per treatment may be necessary to improve osteogenic activity. The use of mesenchymal stem cells from murine bone marrow may also offer a physiologically relevant model for osteoblastic regeneration of periapical lesions. Objectives: The goal of this study was to investigate and optimize the effects of electromagnetic wave stimulation (EMS) on murine bone marrow mesenchymal stem cells (MSCs) by evaluating the proliferation and differentiation of the cells after exposure to different EMS treatment regimens. Materials and Methods: 5 x104 stromal osteoblasts (SOBs) were cultured in 24-well plates in α-MEM containing 10% fetal bovine serum. Cells were then subjected to pulsed EMS treatments of 1 mA, 10 mA, and 50 mA. EMS was generated using an electromagnetic apical treatment (EMAT) device created by J. Morita MFG Corp. Proliferation was assessed via MTS assay 1 days after treatment. For osteogenic differentiation, ascorbic acid and β-glycerol phosphate were added to the culture media, and SOBs were cultured for 14 days. Afterwards, alkaline phosphatase (ALP) activity and Alizarin-red S mineral deposition were quantified as measures of osteoblast activity. Cells grown in osteogenic media without EMS treatment served as the negative control. Results: Although MSC proliferation was unaffected by different EMS treatment regimens, 50 mA EMS resulted in a decrease in ALP activity and mineral deposition by osteoblasts. Conclusions: Our findings suggest bone healing by EMS may involve a different cellular mechanism, that is not reproduced in vitro in our studies. Utilizing different amperage and EMS regimens may improve osteogenic differentiation.
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    Hypophosphatemic rickets: Revealing Novel Control Points for Phosphate Homeostasis
    (Springer US, 2014-09) White, Kenneth E.; Hum, Julia M.; Econs, Michael J.; Department of Medical & Molecular Genetics, IU School of Medicine
    Rapid and somewhat surprising advances have recently been made towards understanding the molecular mechanisms causing heritable disorders of hypophosphatemia. The results of clinical, genetic, and translational studies have interwoven novel concepts underlying the endocrine control of phosphate metabolism, with far-reaching implications for treatment of both rare, Mendelian diseases as well as common disorders of blood phosphate excess such as chronic kidney disease (CKD). In particular, diseases caused by changes in the expression and proteolytic control of the phosphaturic hormone Fibroblast growth factor-23 (FGF23) have come to the forefront in terms of directing new models explaining mineral metabolism. These hypophosphatemic disorders, as well as others resulting from independent defects in phosphate transport or metabolism, will be reviewed herein, and implications for emerging therapeutic strategies based upon these new findings will be discussed.
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    The Importance of Biologically Active Vitamin D for Mineralization by Osteocytes After Parathyroidectomy for Renal Hyperparathyroidism
    (ASBMR, 2019-11) Yajima, Aiji; Tsuchiya, Ken; Burr, David B.; Wallace, Joseph M.; Damrath, John D.; Inaba, Masaaki; Tominaga, Yoshihiro; Satoh, Shigeru; Nakayama, Takashi; Tanizawa, Tatsuhiko; Ogawa, Hajime; Ito, Akemi; Nitta, Kosaku; Anatomy and Cell Biology, School of Medicine
    Hypomineralized matrix is a factor determining bone mineral density. Increased perilacunar hypomineralized bone area is caused by reduced mineralization by osteocytes. The importance of vitamin D in the mineralization by osteocytes was investigated in hemodialysis patients who underwent total parathyroidectomy (PTX) with immediate autotransplantation of diffuse hyperplastic parathyroid tissue. No previous reports on this subject exist. The study was conducted in 19 patients with renal hyperparathyroidism treated with PTX. In 15 patients, the serum calcium levels were maintained by subsequent administration of alfacalcidol (2.0 μg/day), i.v. calcium gluconate, and oral calcium carbonate for 4 weeks after PTX (group I). This was followed in a subset of 4 patients in group I by a reduced dose of 0.5 μg/day until 1 year following PTX; this was defined as group II. In the remaining 4 patients, who were not in group I, the serum calcium (Ca) levels were maintained without subsequent administration of alfacalcidol (group III). Transiliac bone biopsy specimens were obtained in all groups before and 3 or 4 weeks after PTX to evaluate the change of the hypomineralized bone area. In addition, patients from group II underwent a third bone biopsy 1 year following PTX. A significant decrease of perilacunar hypomineralized bone area was observed 3 or 4 weeks after PTX in all group I and II patients. The area was increased again in the group II patients 1 year following PTX. In group III patients, an increase of the hypomineralized bone area was observed 4 weeks after PTX. The maintenance of a proper dose of vitamin D is necessary for mineralization by osteocytes, which is important to increase bone mineral density after PTX for renal hyperparathyroidism.
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    Microcomputed Tomography Applications in Bone and Mineral Research
    (2013-09) Bart, Zachary R.; Wallace, Joseph M.
    Microcomputed tomography (μCT) has evolved as a development of simple X-ray imaging into an indispensable technique used in both laboratory research and clinical diagnostics. Commercially available systems are capable of creating images at sub-micrometer resolutions to map out the complex web of trabecular bone in small animals, and offer an accurate measurement of bone mineral density for patients at risk of osteoporotic fractures. This review describes the development of μCT, its ability to analyze bone, and how it can be used alongside other clinical and laboratory techniques. μCT offers a non-destructive alternative for imaging mineralized tissues with no required preparation and can also be utilized with living specimen to track skeletal development.
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    Osteoporosis and fracture risk: bone matrix quality
    (2002-08) Burr, David B.