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Resorbable bone fixation alloys, forming, and post-fabrication treatments.
Ibrahim, H, Esfahani, SN, Poorganji, B, Dean, D, Elahinia, M
Materials science & engineering. C, Materials for biological applications. 2017;(Pt 1):870-888
Abstract
Metallic alloys have been introduced as biodegradable metals for various biomedical applications over the last decade owing to their gradual corrosion in the body, biocompatibility and superior strength compared to biodegradable polymers. Mg alloys possess advantageous properties that make them the most extensively studied biodegradable metallic material for orthopedic applications such as their low density, modulus of elasticity, close to that of the bone, and resorbability. Early resorption (i.e., <3months) and relatively inadequate strength are the main challenges that hinder the use of Mg alloys for bone fixation applications. The development of resorbable Mg-based bone fixation hardware with superior mechanical and corrosion performance requires a thorough understanding of the physical and mechanical properties of Mg alloys. This paper discusses the characteristics of successful Mg-based skeletal fixation hardware and the possible ways to improve its properties using different methods such as mechanical and heat treatment processes. We also review the most recent work pertaining to Mg alloys and surface coatings. To this end, this paper covers (i) the properties and development of Mg alloys and coatings with an emphasis on the Mg-Zn-Ca-based alloys; (ii) Mg alloys fabrication techniques; and (iii) strategies towards achieving Mg-based, resorbable, skeletal fixation devices.
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2.
Plyometric exercise and bone health in children and adolescents: a systematic review.
Gómez-Bruton, A, Matute-Llorente, Á, González-Agüero, A, Casajús, JA, Vicente-Rodríguez, G
World journal of pediatrics : WJP. 2017;(2):112-121
Abstract
BACKGROUND Many jumping interventions have been performed in children and adolescents in order to improve bone-related variables and thus, ensure a healthy bone development during these periods and later in life. This systematic review aims to summarize and update present knowledge regarding the effects that jumping interventions may have on bone mass, structure and metabolism in order to ascertain the efficacy and durability (duration of the effects caused by the intervention) of the interventions. DATA SOURCES Identification of studies was performed by searching in the database MEDLINE/PubMed and SportDiscus. Additional studies were identified by contacting clinical experts and searching bibliographies and abstracts. Search terms included "bone and bones", "jump*", "weight-bearing", "resistance training" and "school intervention". The search was conducted up to October 2014. Only studies that had performed a specific jumping intervention in under 18-year olds and had measured bone mass were included. Independent extraction of articles was done by 2 authors using predefined data fields. RESULTS A total of 26 studies were included in this review. Twenty-four studies found positive results as subjects included in the intervention groups showed higher bone mineral density, bone mineral content and bone structure improvements than controls. Only two studies found no effects on bone mass after a 10-week and 9-month intervention. Moreover, those studies that evaluated the durability of the effects found that some of the increases in the intervention groups were maintained after several years. CONCLUSIONS Jumping interventions during childhood and adolescence improve bone mineral content, density and structural properties without side effects. These type of interventions should be therefore implemented when possible in order to increase bone mass in early stages of life, which may have a direct preventive effect on bone diseases like osteoporosis later in life.
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3.
[Calciuria as a metabolic marker for various conditions and diseases].
Egshatyan, LV, Mokrysheva, NG
Urologiia (Moscow, Russia : 1999). 2017;(5):132-138
Abstract
The article analyzes the literature on the features of human calcium homeostasis. The authors describe the etiopathogenetic role of calcitropic hormones, the plasma and urine acid-base status, various ions, lifestyle and nutrition and other factors contributing to hypercalciuria due to increased intestinal absorption, bone resorption, impairment of tubular calcium reabsorption, etc. They discuss the role of calciuria as a factor in forming urinary calculi and present their own observations.
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4.
[Bone and Nutrition. Effect of isoflavones on bone health].
Ishimi, Y
Clinical calcium. 2015;(7):999-1005
Abstract
Effects of isoflavones on bone health in postmenopausal women are expected, since it shows weak estrogenic activity. In the observational study in Asia, association between intake of soy foods or isoflavone and bone mineral density and fracture prevention has been observed. In the meta-analysis of intervention trials of isoflavone in 60 years or less of postmenopausal women, 75 mg by day about 6 months to 1 year intervention of isoflavones induced suppression of significant decline of bone resorption markers in the urine was observed. On the other hand, intended for Westerners women in the study intervened isoflavones with calcium and vitamin D simultaneously, it is not observed effectiveness of isoflavones on the bone. Such a difference might be due to diversity in the individual metabolic capacity for isoflavones as well as the effects of presence or absence of other co-interventions nutrients.
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5.
[Progress and problems in oral bisphosphonate].
Takeuchi, Y
Clinical calcium. 2014;(1):27-33
Abstract
Oral bisphosphonates are the first class of drugs other than estrogen that have been proven to reduce fracture incidence substantially. Since they are agents that inhibit bone resorption and are hardly absorbed through intestine, researchers have been focusing on augmentation of inhibitory effects of bisphosphonates on bone resorption and prolongation of the interval of drug administration. Even though they have a break-through efficacy on preventing fractures, there remain some rare problems to be solved, such as osteonecrosis of the jaw and atypical femoral fracture, after long-term exposure to bisphosphonates.
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[Cytokine-mediated bone resorption].
Nakamura, M, Uehara, S, Nakamura, H, Udagawa, N
Clinical calcium. 2014;(6):837-44
Abstract
Osteoclasts, the multinucleated cells that resorb bone, originate from monocyte-macrophage lineage cells. Various hormones, cytokines and growth factors are involved in osteoclastogenesis, via interaction with osteoblasts. In this review, we summarize the regulatory mechanism of bone resorption by various cytokines derived from osteoblasts and hematopoietic inflammatory cells.
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7.
Bilateral condylar resorption in down syndrome.
Grippaudo, C, Grippaudo, FR, Marianetti, TM, Cacucci, L, Deli, R, Pelo, S
The Journal of craniofacial surgery. 2014;(6):e580-2
Abstract
Asymptomatic idiopathic condylar resorption is a rare disease of difficult diagnosis and treatment. We review the literature about this rare condition and report a case of a patient, affected by Down syndrome, who underwent a complete untreated bilateral condylar resorption in adolescence and then developed pain on chewing only 20 years later. Despite a precise orthodontic and surgical therapeutic plan, treatment had to be discontinued because of patient lack of compliance. This case is the first of its kind to be reported and emphasizes the need for special attention in patients with disability.
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8.
Effects of tyrosine kinase inhibition on bone metabolism: untargeted consequences of targeted therapies.
Alemán, JO, Farooki, A, Girotra, M
Endocrine-related cancer. 2014;(3):R247-59
Abstract
Tyrosine kinase inhibitors (TKIs) are at the forefront of molecular-targeted therapies for cancer. With the advent of imatinib for the treatment of chronic myelogenous leukemia, a new wave of small-molecule therapeutics redefined the oncologic treatment to become chronically administered medications with tolerable side-effect profiles compared with cytotoxic agents. Effects on bone mineral metabolism were observed during early imatinib treatment, in the form of hypophosphatemia with increased urinary phosphorus excretion. This finding led to detailed investigations of off-target effects responsible for changes in bone cell maturation, activity, and impact on bone mass. Subsequently, another BCR-Abl inhibitor (dasatinib), vascular endothelial growth factor (VEGF) inhibitors (sorafenib and sunitinib) as well as rearranged during transfection (RET) inhibitors (vandetanib and cabozantinib) were developed. Inhibition of bone resorption appears to be a class effect and is likely contributed by TKI effects on the hematopoietic and mesenchymal stem cells. As long-term, prospective, clinical outcomes data accumulate on these targeted therapies, the full extent of off-target side effects on bone health will need to be considered along with the significant benefits of tyrosine kinase inhibition in oncologic treatment.
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9.
Flavonoid intake and bone health.
Weaver, CM, Alekel, DL, Ward, WE, Ronis, MJ
Journal of nutrition in gerontology and geriatrics. 2012;(3):239-53
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Abstract
Flavonoids, found in a wide diversity of plant foods from fruits and vegetables, herbs and spices, essential oils, and beverages, have the most potential of dietary components for promotion of bone health beyond calcium and vitamin D. Recent epidemiological studies show flavonoid consumption to have a stronger association with bone than general fruit and vegetable consumption. Bioactive flavonoids are being assessed for properties beyond their chemical antioxidant capacity, including anti-inflammatory actions. Some have been reported to enhance bone formation and to inhibit bone resorption through their action on cell signaling pathways that influence osteoblast and osteoclast differentiation. Future research is needed to determine which of the flavonoids and their metabolites are most effective and at what dose, as well as the mechanism of modulating cellular events, in order to set priorities for clinical trials.
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10.
[Strontium ranelate in post-menopausal osteoporosis].
Przedlacki, J
Endokrynologia Polska. 2011;:23-31
Abstract
Strontium ranelate is one of the first-line agents with proven anti-fracture activity used in the therapy of post-menopausal osteoporosis. Its mechanism of action makes it, however, different from other drugs, since it simultaneously stimulates two reverse processes: bone formation and bone resorption. The action of the agent depends on various mechanisms, including the activation of calcium receptors, localised on osteoblasts and osteoclasts, and on the influence on the OPG/RANKL system. The drug effectively prevents spinal, hip and extravertebral fractures. The agent's anti-fracture efficacy within the spine does not depend on the patient's age, or on base BMD values, or on the concentration of bone metabolism markers. As to the anti-fracture efficacy in the hip, it concerns women with an increased bone fracture risk. Strontium ranelate increases bone mineral density within the lumbar spine and the hip, decreases the concentrations of bone resorption markers, and increases the concentrations of bone formation markers. The drug is administered in a daily 2.0 g oral dose. This paper presents indications to therapy with strontium ranelate, specifying also its side effects and contraindications. We compare the anti-fracture efficacy of strontium ranelate to the efficacy of other agents of proven anti-fracture activity, based on published clinical studies.