Bone Metabolic Activity Research Articles

Bone mineralisation adjacent to cemented and uncemented acetabular cups: analysis by [18F]-fluoride-PET in a randomised clinical trial

We present a randomised clinical trial using F-PET/CT to analyse new bone metabolic mineralisation adjacent to acetabular cups following total hip arthoplasty (THA). THA was performed on 26 patients (26 cases) with hip OA. Patients with hip osteoarthritis (OA) were randomly assigned to operations with cemented or uncemented acetabular components. The contralateral, healthy acetabulum was used as referent for normal bone metabolism. The patients were analysed with radiography, clinical scoring, and F-PET/CT preoperatively, and at 6 weeks and 6 months postoperatively. No major complications were recorded, and clinical results were good in all patients. Radiography showed all cups to be stable. The bone-forming activity, as measured by F-PET/CT, was quantified as standardised uptake values (SUV). The mean SUV was 4.6 (6 weeks) and 3.5 (6 months) around the uncemented cups, and 4.8 and 4.0, respectively, for the cemented cups. Normal healthy bone metabolism in the referent was 2.8 and 2.7 SUV at 6 weeks and 6 months, respectively. P < 0.01 for the cemented group at 6 weeks and 6 months, for the uncemented group only at 6 weeks. An acetabulum affected by OA has elevated SUV activity. Both cemented and uncemented cups had elevated bone metabolic activity at 6 weeks. The raised activity was interpreted as an effect from bone mineralisation secondary to surgical trauma and healing, and to the OA. At 6 months, activity was more normalised for the uncemented group than for the cemented, suggesting healing may terminate faster in the uncemented group. Postoperative bone metabolic activity can be analysed in detail by F-PET/CT.ClinicalTrials.gov Identifier: NCT01623687.

The Role of Substance P in the Regulation of Bone and Cartilage Metabolic Activity.

Substance P (SP) is a neuropeptide that is released from sensory nerve endings and is widely present in nerve fibers. It acts on bones and related tissues by binding to receptors, thereby regulating bone metabolism, cartilage metabolism, and fracture healing. SP has attracted widespread attention as a signaling substance that can be recognized by both the immune system and the nervous system. Previous studies have shown that bone and chondrocytes can synthesize and secrete sensory neuropeptides and express their receptors, and can promote proliferation, differentiation, apoptosis, matrix synthesis, and the degradation of target cells through autocrine/paracrine modes. In this paper, we review the research progress made in this field in recent years in order to provide a reference for further understanding the regulatory mechanism of bone and cartilage physiology and pathological metabolism.

Island rule and bone metabolism in fossil murines from Timor

Abstract Skeletal growth rates reconstructed from bone histology in extinct insular hippopotamids, elephants, bovids and sauropods have been used to infer dwarfism as a response to island conditions. Limited published records of osteocyte lacunae densities (Ot.Dn), a proxy for living osteocyte proliferation, have suggested a slower rate of bone metabolism in giant mammals. Here, we test whether insularity might have affected bone metabolism in a series of small to giant murine rodents from Timor. Ten adult femora were selected from a fossil assemblage dated to the Late Quaternary (~5000–18 000 years old). Femur morphometric data were used in computing phylogenetically informed body mass regressions, although the phylogenetic signal was very low (Pagel’s λ = 0.03). Estimates of body weight calculated from these femora ranged from 75 to 1188 g. Osteocyte lacunae densities from histological sections of the midshaft femur were evaluated against bone size and estimated body weight. Statistically significant (P &amp;lt; 0.05) and strongly negative relationships between Ot.Dn, femur size and estimated weight were found. Larger specimens were characterized by lower Ot.Dn, indicating that giant murines from Timor might have had a relatively slow pace of bone metabolic activity, consistent with predictions made by the island rule.

Increase in bone metabolic markers and circulating osteoblast-lineage cells after orthognathic surgery

Increased mineralisation rate and bone formation after surgery or fracture is the regional acceleratory phenomenon (RAP), and its systemic impact is the systemic acceleratory phenomenon (SAP). The proportion of circulating osteoblast lineage cells, including osteocalcin-positive (OCN+) cells, in the peripheral blood is markedly higher during pubertal growth and in patients with bone fractures. This study aimed to elucidate the dynamic changes in bone metabolic activity after orthognathic surgery by longitudinal prospective observation. Peripheral venous blood samples were collected from patients who had undergone orthognathic surgery, and serum bone metabolic markers and the proportion of OCN+ cells were measured. Orthognathic surgery induces systemic dynamic changes in bone metabolic activity by targeting steps in the bone healing process and related proteins, such as surgical stress/inflammation (C-reactive protein), bone resorption (type I collagen C-telopeptide), and bone formation (alkaline phosphatase and bone-specific alkaline phosphatase). During the early post-operative period, the population of OCN+ cells significantly increased. Confocal microscopy revealed that OCN proteins were localised in the cytoplasm in Triton X-100-treated OCN+ cells. Furthermore, OCN, ALP, and COL1A1 gene expression was detected in OCN+ cells, suggesting the contribution of the local maturation of bone marrow-derived OCN+ cells at the site of bone healing.

Effect of minimally invasive plate osteosynthesis through two approaches on bone metabolic activity and radial nerve injury in patients with humeral midshaft fracture

To compare application of minimally invasive plate osteosynthesis (MIPO) through two approaches for patients with humeral midshaft fracture, and analyzes the effect on bone metabolic activity and radial nerve injury. From April 2014 to May 2017, 76 patients with humeral midshaft fracture treated by MIPO were selected and randomly divided into group A (anterior approache group) and group B (lateral approach group) according to random number stable. In group A, there were 38 patients including 22 males and 16 females, aged from 18 to 74 years old with an average age of(48.21±5.79) years old; 24 patients were caused by traffic accidents, 6 patients were caused by heavy object crushing, 8 patients were caused by falling down; 20 patient were on the right side, 18 patients were on the left side; 15 patients were type A, 17 patients were type B, 6 patients were type C according to AO classification; the patients were treated by MIPO through anterior approach. In group B, there were 38 patients including 23 males and 15 females, aged from 20 to 73 years old with an average age of(48.40±5.81) years old; 26 patients were caused by traffic accidents, 5 patients were caused by heavy object crushing, 7 patients were caused by falling down; 17 patients were on the right side, 21 patients were on the left side; 15 patients were type A, 18 cases were type B, 5 cases were type C according to AO classification; the patients were treated by MIPO through lateral approach. Intraoperative blood loss, operative time, hospital stays, fracture healing time between two groups were compared. Bone gla protein (BGP), collagen C-terminal peptide (CTX) and osteoprotegerin (OPG) were tested before and after operation. The incidence of radial nerve injury after operation was observed. All patients were followed-up from 12 to 18 months with an average of (15.4±2.1) months. There were no statistical differences in operative time, intraoperative blood loss between two groups. Hospital stays, fracture healing time in group A were(6.52±1.81) d, (13.27±3.01) weeks respectively, while in group B were(9.61±1.99) d, (14.83±3.08) weeks; and had differences between two groups. There were no differences in BGP, OPG and CTX, BGP between two groups and OPG in group A at 1 month after operation were(7.10±0.58) ng/ml, (173.67±9.12) pg/ml and higher than that of group B(6.63±0.62) ng/ml, (152.80±9.23) pg/ml; while CTX in group A (224.52±12.67) μg/ml was lower than that of group B(259.13±13.54) μg/ml(P<0.05). No patient occurred radial nerve injury in group A, 4 patients occurred radial nerve injury in group B, and had statistical differences between two groups(χ²=4.220, P<0.05). Compared with lateral approach, anterior approach has much more effective in minimally invasive MIPO for humeral shaft fractures, which could improve bone metabolism and reduce risk of radial nerve injury.

Effects of maternal intake restriction during early pregnancy on fetal growth and bone metabolism in goats

• Effect of maternal intake restriction on bone metabolism of goats was investigated. • Maternal intake restriction during early gestation decreased the INTP and CTX-1 in fetal umbilical blood. • Nutritional restriction during early gestion regulated the femur metabolic activity of fetal goats. The objective of this study was to investigate the effects of maternal nutritional restriction on fetal growth and bone metabolism in early pregnancy. Twelve twin-bearing goats (Xiangdong black goats) in second pregnancy, with similar weight (31.2 ± 8.1 kg) and age (2.0 ± 0.3 year) were assigned to two dietary treatments in early gestation (26–65 days): control group (CON, 100% feed) and intake restriction group (IR, 60% of CON intake). The umbilical blood, right femur and liver of the fetuses were sampled on day 65 to determine the bone metabolism indicators and expression of genes involved in bone development. Maternal intake restriction did not affect the growth performance of pregnancies ( P > 0.05), increased ( P < 0.05) the body weight, body length, thoracic circumference and umbilical circumference of fetal goats, but decreased ( P < 0.05) the concentrations of cross-linked N-terminal telopeptides of type I collagen and cross-linked C-terminal telopeptides of type I collagen, which involved in bone metabolic activity, in the fetal umbilical blood of the IR. In fetal femurs, the mRNA expression of bone gamma-carboxyglutamate protein, osteoprotegerin and mothers against decapentaplegic homolog 1 both participating in osteoclast differentiation were increased ( P < 0.05), whereas transcript of the low density lipoprotein receptor related protein 5 involved in osteoblast differentiation was decreased ( P < 0.05), compared with the fetuses from the CON. These results indicate that nutrition restriction in early pregnancy regulated the fetal growth and promoted formative activity of femur. The molecular mechanism of maternal intake restriction on bone metabolism needs further investigation.

Sirtuin 3 deficiency does not impede digit regeneration in mice

The mitochondrial deacetylase sirtuin 3 (SIRT3) is thought to be one of the main contributors to metabolic flexibility–promoting mitochondrial energy production and maintaining homeostasis. In bone, metabolic profiles are tightly regulated and the loss of SIRT3 has deleterious effects on bone volume in vivo and on osteoblast differentiation in vitro. Despite the prominent role of this protein in bone stem cell proliferation, metabolic activity, and differentiation, the importance of SIRT3 for regeneration after bone injury has never been reported. We show here, using the mouse digit amputation model, that SIRT3 deficiency has no impact on the regenerative capacity and architecture of bone and soft tissue. Regeneration occurs in SIRT3 deficient mice in spite of the reduced oxidative metabolic profile of the periosteal cells. These data suggest that bone regeneration, in contrast to homeostatic bone turnover, is not reliant upon active SIRT3, and our results highlight the need to examine known roles of SIRT3 in the context of injury.

Relationship between lower lumbar spine shape and patient bone metabolic activity as characterised by 18F NaF bio-markers

Chronic lower lumbar pain has been associated with elevated bone metabolic activity in the spine. Diagnosis of bone metabolic activity is currently through integrating Positron Emission Tomography (PET) with Sodium Fluoride (18F–NaF) biomarkers. It has been reported that numerous observable pathologies including lumbar fusion, disc abnormalities and scoliosis have often been associated with increased 18F–NaF uptake. The aim of this study was to identify what features of lower lumbar shape most strongly correlate with 18F–NaF uptake. Following a principal component analysis of 23 patients who presented with lumbar pain and underwent 18F–NaF PET-CT, it was revealed that three modes interpreted as (i) sacral tilt, (ii) vertebral disc spacing and (iii) spine size were the three characteristics that described 88.7% of spine shape in our study population. 18F–NaF was described by two modes including 18F–NaF intensity and spatial variation (anterior-inferior to posterior-superior). 18F–NaF was most sensitive to sacral tilt followed by vertebral disc spacing. A predictive model derived from that spine population was able to predict 18F–NaF ‘hot-spot’ locations with 85 ± 5% accuracy and with 71 ± 3% accuracy for the 18F–NaF magnitude. These results suggest that patients reporting with lower lumbar pain and who present with increased sacral tilt profiles and/or reduced disc spacing are good candidates for further 18F–NaF PET-CT imaging, evidenced by the high association between those shape profiles and 18F–NaF uptake.

Radiological Imaging Evaluation of the Failing Total Hip Replacement.

Total hip replacements (THR) have been performed in the UK from the 1960s and since then we have seen surgical techniques, the design of implants, and imaging modalities rapidly develop. This paper will aim to review the different complications and imaging appearance which help to evaluate each problem. As for all investigations for bone and joints, a radiograph is the first imaging to be performed for any patient with a THR and can detect a majority of complications. CT is relatively low-cost, simple to perform and easily available making it an excellent tool to supplement radiographs when trying to evaluate a hip prosthesis. Single photon emission computed tomography with CT (SPECT-CT) is an emerging modality which has shown to combine the sensitivity that bone scintigraphy offers with the high specificity of CT. SPECT imaging also has the advantage of showing the bone's metabolic activity and is less prone to metal artifact than Magnetic resonance imaging (MRI). MRI has evolved to become an important diagnostic tool for the evaluation of THR in the post-operative period. Optimized pulse sequences and metal artifact reduction techniques have made MRI a useful tool in diagnosis of soft tissue abnormalities and is particularly useful in identifying adverse local tissue reactions in metal on metal implants. CT and MRI are accurate in identifying the diagnosis of most causes of THR complications except infection. Research confirms that leukocyte-marrow scintigraphy is the modality of choice for accurately diagnosing prosthetic joint infection and reassures us of its superiority over other nuclear medicine imaging. However, due to the limited availability and increased costs when performing leukocyte-marrow scintigraphy, CT and SPECT-CT would be a more preferred option when suspecting prosthesis infection. Ultrasound (US) has a limited role in the assessment of most THR complications but can be useful to identify peri-prosthetic fluid collections and the presence of soft tissue sinus tracts. Being aware of the imaging modalities that are available to orthopedic surgeons, and discussing these challenging cases with specialist radiologists will enable optimal management of THR complications.

Effects of dietary calcium to available phosphorus ratios on bone metabolism and osteoclast activity of the OPG /RANK/RANKL signalling pathway in piglets.

Hydroxyapatite, a mineral form of calcium (Ca) and phosphorus (P) that gives bones their rigidity, is the major and essential component of bones and teeth in the human and animal body. A suitable ratio of Ca and P is vital for bone growth. The aim of this study was to explore the effects of dietary calcium to available phosphorus ratios (Ca/AP) on bone metabolism and osteoclast activity of the osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL) signalling pathway in piglets. At days 15 and 29, the piglets were assessed for growth performance, blood indicators, cytokines and the OPG/RANK/RANKL signalling pathway. Our results showed that piglets fed a dietary Ca/AP ratio of 2:1 increases growth performance and regulates blood indicators and cytokines (parathyroid hormone (PTH), calcitonin (CT), vitamin D3 (VD3 ), insulin-like growth factor-1 (IGF-1), transforming growth factor-β (TGF-β), interleukin-1 (IL-1), interleukin-6 (IL-6), carboxyterminal propeptide of type I procollagen (PICP), tartrate-resistant acid phosphatase (TRACP), alkaline phosphatase (ALP) and osteocalcin (OCN) content). We also demonstrated that this ratio affects hormone secretion and further bone metabolism through the OPG/RANK/RANKL signalling pathway of osteoclasts. These results indicate that a suitable dietary Ca/AP ratio is vital for bone growth and reduce the incidence of bone diseases such as osteoporosis, providing a practical basis for the raising of piglets.

Prevalence of Bone Loss and the Short-Term Effect of Anti-retroviral Therapy on Bone Mineral Density in Treatment-Naïve Male Japanese Patients with HIV

Background: There have been few studies have shown the relationship between HIV and low Bone Mineral Density (BMD) in Asian countries. In particular, research on the early impact of anti-HIV drugs on BMD is scarce. Objective: We studied the prevalence of bone loss and changes of BMD after the start of Anti-Retroviral Therapy (ART) in Japanese naïve patients with HIV. Methods: Male patients with HIV who visited our hospital between 2010 and 2016 were enrolled. Patients underwent BMD analyses before and one year after ART. Changes in BMD after ART initiation were evaluated by paired t-tests. To identify clinical factors affecting BMD after ART initiation based on the BMD change ratio, multiple regression analysis was performed. Results: Thirty-one patients were followed up. By employing the T-scores in the lumbar spines and femoral necks, the prevalence of osteopenia and osteoporosis was found to be 38.7-45.2% and 6.2% respectively. There were significant BMD decreases after ART initiation. Use of Tenofovir Disoproxil Fumarate (TDF) / emtricitabine (FTC), use of Protease Inhibitors (PIs), and low CD4 cell counts were independent risk factors for lumbar spine BMD decrease. Urinary N-terminal telopeptide / creatinine was the independent risk factor for femoral neck BMD decrease. Conclusions: Low BMD was prevalent in our study cases. Low CD4 cell counts at the onset of ART initiation, TDF/FTC use, and PI use increased the risk of lumbar spine BMD decrease significantly more, while ART affected femoral neck BMD of patients with higher bone metabolic activity significantly more.

The influence of CT and dual-energy X-ray absorptiometry (DXA) bone density on quantitative [18F] sodium fluoride PET.

[18F] sodium fluoride PET/CT provides quantitative measures of bone metabolic activity expressed by the parameters standardised uptake value (SUV) and bone plasma clearance (K i) that correlate with measurements of bone formation rate obtained by bone biopsy with double tetracycline labelling. Both SUV and K i relate to the tracer uptake in each millilitre of tissue. In general, the bone region of interest (ROI) includes both mineralised bone {generally with a high concentration of [18F]NaF} and bone marrow (with a much lower concentration), suggesting that correcting SUV and K i for volumetric bone mineral density (vBMD) and measuring them with respect to the tracer uptake in each gram of bone mineral might improve the correlation with the findings of bone biopsy. As a first test of this hypothesis, we looked for positive correlations between SUV and K i values with CT and DXA bone mineral density (BMD) parameters measured in the same ROI. A retrospective reanalysis was performed of 63 lumbar spine [18F]NaF PET/CT scans acquired in four earlier studies. The quantitative PET parameters SUV and K i were measured in L1-L4 and Hounsfield units (HU) measured on the CT scans in the same ROI. Spine BMD data was also obtained from DXA scans in the form of areal BMD and used to derive the bone mineral apparent density (BMAD, an estimate of vBMD). Scatter plots were drawn of SUV and K i against HU, BMAD and areal BMD and the Spearman rank correlation coefficients derived for each plot. All correlations were positive and statistically significant. Correlations were highest for HU (SUV: RS =0.513, P<0.0001; K i: RS =0.429, P=0.0005) and lowest for areal BMD (SUV: RS =0.353, P=0.005; K i: RS =0.274, P=0.03). The results demonstrate significant positive correlations between SUV and K i and vBMD measurements in the form of HU from CT or BMAD and areal BMD from DXA. These findings justify further exploration of the relationship between SUV and K i [18F]NaF PET/CT measurements and CT or DXA measurements of vBMD to examine whether normalization for bone density might improve their correlation with bone metabolic activity as measured by bone biopsy.

BISPHOSPHONATE-RELATED OSTEONECROSIS OF THE JAW

Bisphosphonates (BPs) are a class of drug used to treat osteoporosis and malignant bone metastasis. BPs show high binding capacity to the bone matrix, especially in sites of active bone metabolism. According to modern data, bisphosphonate osteonecrosis of the jaws (BPONJ) is a complication of antiresorptive therapy, characterized by death and exposure of the bone area, which persists for more than 8 weeks, with subsequent progression of the process, provided there is no radiation therapy on the head area in history. BRONJ can adversely affect quality of life, as it may produce significant morbidity. The purpose of this article is to offer a perspective on how dentists should manage patients on BPs, and to present diagnostic aids and treatment s strategies to the condition.

Prostaglandin E2 mediates sensory nerve regulation of bone homeostasis

Whether sensory nerve can sense bone density or metabolic activity to control bone homeostasis is unknown. Here we found prostaglandin E2 (PGE2) secreted by osteoblastic cells activates PGE2 receptor 4 (EP4) in sensory nerves to regulate bone formation by inhibiting sympathetic activity through the central nervous system. PGE2 secreted by osteoblasts increases when bone density decreases as demonstrated in osteoporotic animal models. Ablation of sensory nerves erodes the skeletal integrity. Specifically, knockout of the EP4 gene in the sensory nerves or cyclooxygenase-2 (COX2) in the osteoblastic cells significantly reduces bone volume in adult mice. Sympathetic tone is increased in sensory denervation models, and propranolol, a β2-adrenergic antagonist, rescues bone loss. Furthermore, injection of SW033291, a small molecule to increase PGE2 level locally, significantly boostes bone formation, whereas the effect is obstructed in EP4 knockout mice. Thus, we show that PGE2 mediates sensory nerve to control bone homeostasis and promote regeneration.

Gut microbiota, probiotics, prebiotics and bone health: a review

Gut microbiota is widely accepted to play a crucial role to host health via the regulation of many physiological functions, including metabolism, nutrition, pathogen resistance, and immune function. Over the last decades, accumulating evidence has also pinpointed a role for gut microbiota on bone metabolism and the development of metabolic bone diseases, such as osteoporosis. Emerging evidence suggests the potential of gut microbiota as a promising target for bone health management. In this contribution, we have examined the available literature to understand the role of gut microbiota on bone metabolism as well as the underlying mechanisms. Furthermore, the application and effectiveness of using probiotics/prebiotics as means to modify gut microbiota and bone health are discussed. In this relation, animal studies and human trails suggest that alternation of gut microbiota composition can exert the activity of bone metabolism and therefore lead to the change of bone quality. It is believed that gut microbiota regulates bone metabolism via host immune system, endocrine system and mineral absorption. Supplementation with probiotics and prebiotics to both animals and humans has demonstrated promising, but sometimes conflicting results, on bone health. Thus, future research is expected to reveal the influence of the variations in age, gender, dose, delivery method, and treatment duration, among others on the probiotics/prebiotics-targeted bone diseases treatment.

Correlation of bone marrow cellularity and metabolic activity in healthy volunteers with simultaneous PET/MR imaging.

To evaluate the correlation between bone marrow cellularity (BMC) and metabolic activity in healthy subjects and to see whether yellow marrow is indeed metabolically quiescent. Because metabolic activity can be assumed to reflect vascularity, we assessed the relationship between regional metabolic activity and geographic frequency of metastases as noted in the literature. Two hundred and twenty locations (ten in each side of the pelvis and proximal femur) were evaluated in 11 consecutive healthy volunteers with simultaneous PET/MR. BMC was calculated through precise water-fat fraction quantification with a 6-echo gradient echo. We analyzed correlations between cellularity and SUVr, age, and R2*. We also looked at the relation between our results and the reported prevalence of metastases. There was moderate but statistically significant correlation between BMC and metabolic activity (r = 0.636, p < 0.0001). Interestingly, the iliac and sacrum had higher metabolic activity relative to cellularity, whereas the femoral neck and lesser trochanter showed lower SUVr than other regions with the similar cellularity. The relatively lower metabolic status of the femoral neck conflicted with its reported high frequency of metastasis. Excluding regions with almost no remaining red marrow, cellularity showed inverse relationship with age (r = 0.476, p < 0.0001) and direct relationship with R2* (r = 0.532, p < 0.0010). Metabolic activity of bone marrow was largely dependent on BMC while yellow marrow seems metabolically quiescent. The discrepancy between the assumed vascularity as determined by metabolic activity and reported sites of metastasis suggested that the process of bone metastasis may not depend entirely on vascularity.

Bildgebende Diagnostik bei medikamenteninduzierten Kiefernekrosen

Drug-induced osteonecrosis of the jaw represents arelatively new, multifactor-induced disease. Diseases with increased bone resorption are widely treated with antiresorptive drugs. Due to the active bone metabolism, especially in the lower jaw, it can lead to osteonecrosis if the barrier function in the oral cavity is impaired and it may be complicated by systemic comorbidities depending on duration, intensity, and application of antiresorptive therapy. Due to the special influence of these changes on the quality of life and because of the complex therapy management, the early detection and determination of the extent of the lesion(s) by imaging is of particular importance. The orthopantomography (panoramic radiography) of the jaw provides agood basic examination, especially for the detection of dental causes as apossible differential diagnosis. Three-dimensional imaging techniques such as computed tomography and in particular magnetic resonance imaging can detect bone changes much more sensitively and detect the manifestation of complex pathologies in higher stages of disease.

The effects of parity and litter size on bone metabolic activity in pregnant and lactating sows.

During gestation and lactation, female mammals often mobilize endogenous nutrient reserves to meet the resource demands of offspring production. These mobilized stores include calcium, phosphorous and other minerals that are resorbed from maternal bone to facilitate rapid mineralization of offspring bones. The extent to which bone mineral is resorbed is governed by the total amount of mineral taken in from the diet, but also by the competing demands of offspring and the minimum level of bone density that a female must sustain to support self-maintenance. The maximum amount of bone that a female may mobilize is undoubtedly dependent a variety of maternal traits, including age and reproductive experience (i.e., parity). We evaluated changes in serum concentrations of biomarkers of metabolic activity (total deoxypyridinoline [tDPD] and osteocalcin [OC]) of maternal bone and its relationship to reproductive output and parity throughout pregnancy and lactation in Yorkshire sows. Litter size did not affect bone metabolism; however, serum concentrations of both tDPD and OC were significantly higher in sows with little or no reproductive experience when compared to sows that had produced at least 3 litters prior to the current reproductive bout. This suggests a shift in ability or physiological strategy to meet offspring mineral demands that is acquired or associated with reproductive experience.

THE STRESS-INDUCED BONE RESORBTION IN RAT IN OPEN FIELD

Background . Osteoporosis and osteomalacia are insensibly diseases, therefore assessment of risk factors is signifi cant for their diagnosis, prophylaxis and treatment. Now the depression is considered as factor of osteoporosis, but emotional stress is not related to risk factors of system bone diseases. Pathogenesis of osteoporosis during depression isn’t full studied. Objective — investigate the stress-induced bone resorption in rat in open fi eld. Design and methods. The study was realized on both male and female white outbred rats. Rats were placed in open fi eld for 3, 30 and 60 minutes. Rat behavior, functional activity of stress-releasing systems, bone metabolism and weight related parameters stress-sensitivity organs and femur was measured. Results. Placement in open fi eld had no effect on weight related parameters stress-sensitivity organs and femur. The function activity of stress systems, calcium and free hydroxyproline blood levels in rats were increased during 3 minutes in open fi eld. At this time histological changes on pelvic bone slice were not observed. Over 30 and 60 minutes in open fi eld hydroxyproline blood level was normalized, but calcium blood level was elevated and the osteocytic osteolysis traces were observed on pelvic bone slice. Stress-induced bone resorption was associated with higher grooming in rat behavior. Conclusion. Bone resorption develop during fi rst 3 minutes of emotional stress and provided by оsteocytic osteolysis mechanism during at the least one hour.

Urinary Bone Turnover Markers as Target Indicators for Monitoring Bisphosphonate Drug Treatment in the Management of Osteoporosis.

Osteoporosis is a debilitating disease characterized by bone micro-architecture degradation contributing to fragility fractures. Currently, determining bone mineral density (BMD) via dual-energy X-ray absorptiometry (DXA) is the most reliable form of diagnosing osteoporosis and managing pharmacological treatment regimens. However, changes in BMD occur slowly (i.e., several months) and DXA does not reflect the metabolic rate of bone turnover. Alternatively, biochemical bone turnover markers are metabolic indicators released into serum and/or urine, and their quantity reflects the metabolic activity of bone. bone turnover markers show a rapid response following antiresorptive drug administration, and enzyme-linked immunosorbent assays (ELISA) have been established and used in clinical trials to help assess and predict fracture risk independent of BMD. This review highlights various established bone turnover markers that have found utility in the clinic as reliable and standardized indicators of bone turnover, with attention to those used to assess efficacy of bisphosphonate drug therapy - particularly in monitoring medication adherence in patients with postmenopausal osteoporosis. We posit that the use of urinary bone turnover markers values determined by immunoassay or ELISA at routine clinic visits might serve as valuable feedback to healthcare professionals and patients to help monitor the efficacy and adherence of bisphosphonate therapy and disease progression. Our belief is that when assessed in combination with an algorithm of independent risk factors, measuring urinary bone turnover markers using a point of care kit may find utility in the osteoporosis clinic as an accessible, non-invasive and cost-effective alternative for the routine assessment of efficacy of bisphosphonate therapies.