scholarly journals MINERAL DENSITY OF BONE TISSUE AND INDICATORS OF BONE REMODELING IN HIGHLY SKILLED ATHLETES IN THE ANNUAL TRAINING CYCLE

2020 ◽  
Vol 19 (4) ◽  
pp. 43-49
Author(s):  
K Nikitina ◽  
T Abramova ◽  
T Nikitina

Aim. The article aims at studying the relationship between the mineral density of heel bone and bone remodeling in cyclistduring the annual training cycle. Materials and methods. The study involved 14 highly skilled male cyclists (cycle track, MS, MSIC) aged 20–25 years with a sports experience of 5 to 16 years. The measurements were performed in the preparatory, pre-competitive and competitive periods of the annual training cycle. Bone mineral density (BMD) was measured by the method of quantitative ultrasound densitometry (QUS) using the Achilles Express ultrasonometer (Lunar, USA). BMD was estimated as a percentage of the peak norm for a given section of the skeleton (reference norms for 20–29 years). Results. The dynamics of BMD in the annual cycle correlates with a change in bone remodeling and phosphorus-calcium metabolism. A decrease in BMD during the competitive period is associated with an increase in β-Cross Laps and a decrease in osteocalcin, alkaline phosphatase, ionized calcium and serum phosphorus. Conclusion. A decrease in BMD is associated with an increase in the activity of osteoclasts and a decrease in osteoblastic activity. Indicators of bone remodeling and phosphorus-calcium metabolism reflect the status of bone tissue and the processes of general adaptation to training loads, and can be used as markers of risk of decreased BMD. The heel bone QUS method can be used to identify athletes at risk for hypotrophic conditions.

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. Christodoulou ◽  
T. Goula ◽  
A. Ververidis ◽  
G. Drosos

Vitamin D is important for normal development and maintenance of the skeleton. Hypovitaminosis D adversely affects calcium metabolism, osteoblastic activity, matrix ossification, bone remodeling and bone density. It is well known that Vit. D deficiency in the developing skeleton is related to rickets, while in adults is related to osteomalacia. The causes of rickets include conditions that lead to hypocalcemia and/or hypophosphatemia, either isolated or secondary to vitamin D deficiency. In osteomalacia, Vit. D deficiency leads to impairment of the mineralisation phase of bone remodeling and thus an increasing amount of the skeleton being replaced by unmineralized osteoid. The relationship between Vit. D and bone mineral density and osteoporosis are still controversial while new evidence suggests that Vit. D may play a role in other bone conditions such as osteoarthritis and stress fractures. In order to maintain a “good bone health” guidelines concerning the recommended dietary intakes should be followed and screening for Vit. D deficiency in individuals at risk for deficiency is required, followed by the appropriate action.


2021 ◽  
Author(s):  
Shinya Hayashi ◽  
Yuichi Kuroda ◽  
Naoki Nakano ◽  
Tomoyuki Matsumoto ◽  
Tomoyuki Kamenaga ◽  
...  

Abstract Background: We aimed to investigate the relationship between stem insertion alignment and postoperative bone mineral density (BMD) changes in patients with full hydroxyapatite-coated (HA) compaction short stem and short tapered-wedge stem. Methods: This retrospective cohort study enrolled 115 consecutive patients (115 joints) undergoing total hip arthroplasty (THA) using the full HA compaction short (n=59) and short tapered-wedge (n=56) stems. Stem alignment including anteversion, valgus, and anterior tilt were measured by 3D-template using computed tomography (CT) data. Post-operative peri-prosthetic BMD was measured by dual-energy X-ray absorptiometry (DEXA). The relationship between stem alignment and BMD changes in the stems were analyzed.Results: Both groups showed similar patterns of peri-prosthetic BMD changes. Stem insertion alignments of anteversion, valgus, and anterior tilt were different between the two types of stems. Stem alignment of valgus and anterior tilt did not affect peri-prosthetic BMD in either type of stem. An absolute anteversion difference between stem anteversion and original canal anteversion caused significant peri-prosthetic BMD loss in Gruen zones 1 and 7 in the tapered-wedge stem. However, stem alignment of absolute anteversion difference did not affect BMD changes in the HA compaction stem.Conclusion: Peri-prosthetic bone remodeling remained unaffected by stem alignment after THA with the new short full HA compaction stem.


2021 ◽  
Vol 50 (3) ◽  
pp. 70-75
Author(s):  
S. V. Yureneva ◽  
V. P. Smetnik ◽  
N. V. Lyubimova ◽  
V. M. Abaev

Twenty women with surgical menopause, 40-50 years of age, received hormonal replacement therapy with transdermic preparation Divigel during 24 months. On the background of therapy with Divigel we witnessed normalization of indeces of osteal remodelingconsiderable decrease pyridinoline and deoxypyridinoline, and elevation of alkaline phosphatase. Mineral density of bone tissue in the group of patients with surgical menopause waslowerin comparison with control (p0,01). Divigeltumedto exertprotective influence on the bone tissue inpatients with osteoporosis irrespective о f duration о f surgical menopause by the beginning of therapy.


2020 ◽  
Vol 7 ◽  
Author(s):  
Irene Llorente ◽  
Noelia García-Castañeda ◽  
Cristina Valero ◽  
Isidoro González-Álvaro ◽  
Santos Castañeda

Osteoporosis has been classically considered a comorbidity of rheumatoid arthritis (RA). However, recent advances in the pathogenesis of osteoporosis in RA have shown a close interplay between cells of the immune system and those involved in bone remodeling, introducing new actors into the classic route in which osteoclast activation is related to the RANK/RANKL/OPG pathway. In fact, the inflammatory state in early stages of RA, mediated by interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α has the ability to activate and differentiate osteoclasts not only through their relationship with RANKL, but also through the Wnt/DKK1/sclerostin pathway, leading to bone loss. The role of synovial fibroblasts and activated T lymphocytes in the expression of the RANKL system and its connection to bone destruction is also depicted. In addition, autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies are other pathogenic mechanisms for the development of bone erosions and systemic osteoporosis in RA, even before the onset of arthritis. The aim of this review is to unravel the relationship between different factors involved in the development of osteoporosis in RA patients, both the classic factors and the most novel, based on the relationship of autoantibodies with bone remodeling. Furthermore, we propose that bone mineral density measured by different techniques may be helpful as a biomarker of severity in early arthritis patients.


2018 ◽  
Vol 9 (1) ◽  
pp. 124-129
Author(s):  
S. B. Pavlov ◽  
N. M. Babenko ◽  
M. V. Kumetchko ◽  
O. B. Litvinova

The fact is disturbance of the processes of bone tissue remodeling leads to a change in the balance between synthesis and resorption of bone and the development of osteoporosis. The most common cause of secondary osteoporosis is the use of glucocorticoid therapy. The aim of this study is to investigate the cellular-molecular mechanisms of disturbance of the processes of bone remodeling regulation, reflected by hormones and intercellular mediators (for example parathyroid hormone, calcitonin, RANKL, osteoprotegerin, P-selectin, interleukin-17, transforming growth factor-β1, adiponectin and visfatin) on the background experimental glucocorticoid osteoporosis. The experimental study carried out in two groups of white female rats. Disturbance of bone tissue remodeling was verified by histological examination of the femoral head, vertebrae of the thoracic and lumbar spine of rats and the measurement of bone density. The study of the levels of hormones and intercellular mediators in the blood serum of animals was carried out by the method of enzyme immunoassay. The bone mineral density of the experimental group was reduced compared to the bone mineral density of the control group. The study of the histostructure of the femoral head and vertebrae in rats of the experimental group in comparison with the animals of the control group revealed changes in the structural organization of bone tissue, confirmed by histomorphometry, indicating inhibition of the processes of osteosynthesis. The article analyzes the nature of the involvement of hormones and cytokines in pathogenetic mechanisms of development of bone tissue disorders. The levels of cytokines RANKL, osteoprotegerin, interleukin-17 and calcitonin in the blood serum of animals of the group with the violation of bone tissue remodeling by glucocorticoids were higher than in intact animals. Serum levels of P-selectin, parathyroid hormone, transforming growth factor-β1, adiponectin and visfatin were lower than similar levels in animals from the control group. The use of glucocorticoids increases the expression of RANKL and inhibits the synthesis of osteoprotegerin, resulting in stimulation of bone resorption. The effect of glucocorticoids in the experimental model is realized by changing the production of the studied hormones, cytokines and adhesion molecules. These changes stimulate the apoptosis of osteoblasts and inhibit their proliferation and differentiation, which is another mechanism of bone loss. Correlations found during the study reflect the relationship in the system of regulation of bone tissue remodeling under the influence of glucocorticoids. A complex system for regulating bone remodeling, which includes many regulatory pathways and their interactions, requires further study.


2021 ◽  
Vol 11 (3) ◽  
pp. 118-125
Author(s):  
V.S. Shapovalov ◽  
A.S. Musiienko

The article summarizes the data on senile osteoporosis and presents a clinical case of this disease. The reference sources on peculiarities of bone remodeling in senile osteoporosis are summarized; low bone formation takes place against the background of a pronounced bone resorption. The article also presents pathomorphological features of bone tissue remodeling resul­ting in pronounced impairments of the compact bone, which increase the risk of fracture. Vitamin D plays a significant role in the complex mechanism of senile osteoporosis. The data on the combined effect of vitamin D and parathormone on bone remodeling are summarized. The paper presents data on other cumulative effects of senile osteoporosis development. Against the background of ­ageing-associated systemic changes, calcium and vitamin D deficiency, increased pro-inflammatory cytokine expression, loca­lized bone disorders develop. An important link to the development of senile osteoporosis is an increased marrow adipose tissue with an intensified adipogenesis, resulting in a decrease of osteoblasts due to the toxic effects of adipokines, reduced differentiation and proliferation of osteoblasts. Age-associated immune-related mechanisms of inflammation, indirectly affecting the bone, are consi­dered. Peculiarities of the senile osteoporosis diagnostics by means of bone mineral density assessment tools are described. Despite the successes achieved in the study of senile osteoporosis development mechanisms, further research is required to explore local and systemic factors affecting bone tissue which are involved in the development of this disease.


Author(s):  
A. Amanzholkyzy

THE RELATIONSHIP BETWEEN DEXOXYRIDINOLINE AND MINERAL DENSITY OF BONE TISSUE IN ADOLESCENTS


2012 ◽  
Vol 14 (1) ◽  
pp. 45-72
Author(s):  
Morteza Karimi-Nia

The status of tafsīr and Qur'anic studies in the Islamic Republic of Iran has changed significantly during recent decades. The essay provides an overview of the state of Qur'anic studies in Iran today, aiming to examine the extent of the impact of studies by Western scholars on Iranian academic circles during the last three decades and the relationship between them. As in most Islamic countries, the major bulk of academic activity in Iran in this field used to be undertaken by the traditional ʿulamāʾ; however, since the beginning of the twentieth century and the establishment of universities and other academic institutions in the Islamic world, there has been increasing diversity and development. After the Islamic Revolution, many gradual changes in the structure and approach of centres of religious learning and universities have occurred. Contemporary advancements in modern sciences and communications technologies have gradually brought the institutions engaged in the study of human sciences to confront the new context. As a result, the traditional Shīʿī centres of learning, which until 50 years ago devoted themselves exclusively to the study of Islamic law and jurisprudence, today pay attention to the teaching of foreign languages, Qur'anic sciences and exegesis, including Western studies about the Qur'an, to a certain extent, and recognise the importance of almost all of the human sciences of the West.


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