scholarly journals Chronic Lead Exposure Alters Mineral Properties in Alveolar Bone

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 642
Author(s):  
Pedro Álvarez-Lloret ◽  
Cristina Benavides-Reyes ◽  
Ching-Ming Lee ◽  
María Pilar Martínez ◽  
María Inés Conti ◽  
...  
Keyword(s):  
Bone Mineral ◽  
Lead Exposure ◽  
Alveolar Bone ◽  
Bone Mineralization ◽  
Bending Test ◽  
Emission Spectrometry ◽  
Mineral Density ◽  
Trabecular Thickness ◽  
Three Point Bending ◽  
Chronic Lead Exposure

The objective of the present study was to investigate the effects of chronic lead exposure on the mineral properties of alveolar bone. For this purpose, female Wistar rats (n = 8) were exposed to 1000 ppm lead acetate in drinking water for 90 days, while the control group (n = 5) was treated with sodium acetate. The alveolar bone structure and chemical composition of the dissected mandibles were examined using micro-computed tomography (micro-CT), scanning electron microscopy (SEM), inductively coupled plasma optical emission spectrometry (ICP-OES), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray diffraction (XRD) techniques to determine possible alterations in alveolar bone due to lead exposure. In addition, changes in bone mechanical properties were analysed using a three-point bending test. Exposure to lead induced notable changes in bone mineralization and properties, specifically a reduction of the trabecular thickness and bone mineral density. Furthermore, there was a reduction in carbonate content and an increase in bone mineral crystallinity. These changes in bone mineralization could be explained by an alteration in bone turnover due to lead exposure. Three-point bending showed a trend of decreased displacement at failure in the mandibles of lead-exposed rats, which could compromise the mechanical stability and normal development of the dentition.

scholarly journals Programming Effect of the Parental Obesity on the Skeletal System of Offspring at Weaning Day

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 424
Author(s):  
Radoslaw Piotr Radzki ◽  
Marek Bienko ◽  
Dariusz Wolski ◽  
Monika Ostapiuk ◽  
Pawel Polak ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Mineral ◽  
High Energy ◽  
Diet Group ◽  
Male Rats ◽  
Bending Test ◽  
Male Rat ◽  
Skeletal System ◽  
Mineral Density ◽  
Trabecular Thickness

Our study aimed to verify the hypothesis of the existence of a programming effect of parental obesity on the growth, development and mineralization of the skeletal system in female and male rat offspring on the day of weaning. The study began with the induction of obesity in female and male rats of the parental generation, using a high-energy diet (group F). Females and males of the control group received the standard diet (group S). After 90 days of dietary-induced obesity, the diet in group F was changed into the standard. Rats from groups F and S were mated to obtain offspring which stayed with their mothers until 21 days of age. Tibia was tested using dual-energy X-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), micro-computed tomography (µCT) and mechanical strength using the three-point bending test. Biochemical analysis of blood serum bone metabolism markers was performed. DXA analysis showed higher tibia bone mineral content (BMC) and area. pQCT measurements of cortical and trabecular tissue documented the increase of the volumetric bone mineral density and BMC of both bone compartments in offspring from the F group, while µCT of the trabecular tissue showed an increase in trabecular thickness and a decrease of its separation. Parental obesity, hence, exerts a programming influence on the development of the skeletal system of the offspring on the day of the weaning, which was reflected in the intensification of mineralization and increased bone strength.

Relation between mechanical stiffness and vibration transmission of fracture callus: An experimental study on rabbit tibia

1998 ◽  
Vol 212 (5) ◽  
pp. 327-336 ◽  
Author(s):  
O Akkus ◽  
F Korkusuz ◽  
S Akin ◽  
N Akkas
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Bending Test ◽  
Bone Mineral Density Change ◽  
Mineral Density ◽  
Mechanical Stiffness ◽  
Fracture Callus ◽  
Vibration Transmission ◽  
Three Point Bending ◽  
Rabbit Tibia

It has been suggested that the vibration transmission across a fracture is affected by the stages of healing of the fracture callus. This study aims to correlate the change in vibration transmission with mechanical stiffness of the callus measured by three-point bending. The right tibiae of male, three-month old local albino rabbits were osteotomized and stabilized by intramedullary fixation following open reduction. The intramedullary rods were removed on the 15th, 28th, 42nd and 90th days postoperatively and the tibiae were excised for vibration, three-point bending and bone mineral density analysis by quantitative computerized tomography (QCT). Optimum time for clinical weight bearing was determined by checking the convergence of the vibration parameters of the fractured tibia to those of the unfractured contralateral. The conclusions obtained from curvature analysis, based on vibration experiments, were in considerable correlation (Spearman's rank correlation coefficient r = 0.93, p = 0.003) with the conclusions obtained from the three-point bending test data which reflected the mechanical condition of the bone by direct means. However, no correlation between bone mineral density change and vibration transmission was noted.

scholarly journals Skeletal effects of a gastrin receptor antagonist in H+/K+ATPase beta subunit KO mice

2016 ◽  
Vol 230 (2) ◽  
pp. 251-262 ◽  
Author(s):  
Kristin M Aasarød ◽  
Masoud Ramezanzadehkoldeh ◽  
Maziar Shabestari ◽  
Mats P Mosti ◽  
Astrid K Stunes ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Bone Quality ◽  
Bone Mineral ◽  
Proton Pump ◽  
Beta Subunit ◽  
Bending Test ◽  
Trabecular Thickness ◽  
Gastrin Receptor ◽  
Three Point Bending ◽  
Cck2 Receptor

Epidemiological studies suggest an increased fracture risk in patients taking proton pump inhibitors (PPIs) for long term. The underlying mechanism, however, has been disputed. By binding to the gastric proton pump, PPIs inhibit gastric acid secretion. We have previously shown that proton pump (H+/K+ATPase beta subunit) KO mice exhibit reduced bone mineral density (BMD) and inferior bone strength compared with WT mice. Patients using PPIs as well as these KO mice exhibit gastric hypoacidity, and subsequently increased serum concentrations of the hormone gastrin. In this study, we wanted to examine whether inhibition of the gastrin/CCK2 receptor influences bone quality in these mice. KO and WT mice were given either the gastrin/CCK2 receptor antagonist netazepide dissolved in polyethylene glycol (PEG) or only PEG for 1year. We found significantly lower bone mineral content and BMD, as well as inferior bone microarchitecture in KO mice compared with WT. Biomechanical properties by three-point bending test also proved inferior in KO mice. KO mice receiving netazepide exhibited significantly higher cortical thickness, cortical area fraction, trabecular thickness and trabecular BMD by micro-CT compared with the control group. Three-point bending test also showed higher Young’s modulus of elasticity in the netazepide KO group compared with control mice. In conclusion, we observed that the gastrin receptor antagonist netazepide slightly improved bone quality in this mouse model, suggesting that hypergastrinemia may contribute to deteriorated bone quality during acid inhibition.

Effects of short-term glucocorticoid administration on bone mineral density, biomechanics and microstructure in rats’ femur

2016 ◽  
Vol 36 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Y Chen ◽  
L Huang ◽  
J Zhu ◽  
K Wu
Keyword(s):  
Bone Mineral Density ◽  
Body Weight ◽  
Bone Mineral ◽  
Body Weight Gain ◽  
Bending Test ◽  
Whole Body ◽  
Control Group ◽  
Mineral Density ◽  
Short Term ◽  
Trabecular Thickness

The effects of short-term use of oral glucocorticoid (GC) on the skeleton are not well defined. To address this gap, the influences of 7 days, 21 days of GC administration on femurs of intact rats were investigated. Forty 4-month-old female Sprague–Dawley rats were randomly divided into control group (Cont) and prednisone-treated group (Pre) and administered either distilled water or prednisone acetate at doses of 3.5 mg/kg/day for 0, 7 and 21 days, respectively. All the femurs were harvested for dual-energy X-ray absorptiometry scan, biomechanical testing and micro computed tomography scan. The whole body weight, femur bone mineral density (BMD), all three-point bending test parameters, microstructural parameters increased or improved significantly in Cont at day 21 when compared to day 0. The whole body weight, distal femur BMD, Young’s modulus, bending stiffness, density of tissue volume and trabecular thickness (Tb.Th) decreased, while structure model index and trabecular separation (Tb.Sp) increased significantly in Pre at day 21 when compared to age-matched control but had no significant differences between day 7 and day 21. Our data demonstrate that 7-day use of prednisone does not influence on rats’ femur, and 21-day use of prednisone slows in rate of whole body weight gain, decreases femur metaphysis BMD and bone stiffness which mainly due to the deteriorated bone microstructure.

The Effect of Hormonal Oral Contraception on Acquisition of Peak Bone Mineral Density of Adolescents and Young Women

2012 ◽  
Vol 25 (3) ◽  
pp. 331-340 ◽  
Author(s):  
Susan Ziglar ◽  
Tracy S. Hunter
Keyword(s):  
Bone Mineral Density ◽  
Bone Mass ◽  
Bone Mineral ◽  
Young Women ◽  
Bone Mineralization ◽  
Critical Time ◽  
Health Concern ◽  
Mineral Density ◽  
Peak Bone Mineral Density ◽  
Bone Mass Accrual

Maximizing bone mass in youth is touted as the best strategy to offset the natural losses of aging and the menopausal transition. Not achieving maximum peak bone mineral density (BMD) is an independent risk factor for osteoporosis and thus a public health concern. Adolescence is a critical time of bone mineralization mediated by endogenous estradiol. Research has shown that the highest velocity of bone mass accrual occurs 1 year before menarche and after the first 3 years. Low-peak attainment of BMD in young women is associated with contributing factors such as diets low in calcium, eating disorders, lack of exercise, smoking, and low estrogen states. Oral contraceptives (OCs) suppress endogenous estradiol production by suppressing the hypothalamic–pituitary–ovarian axis. Thus, OCs, by replacing endogenous estradiol with ethinyl estradiol (EE), establish and maintain new hormone levels. The early initiation and the use of very low dose of EE raises the possibility that bone mass accrual at a critical time of bone mineralization in young women or adolescents may be jeopardized. This review examines the studies of BMD in adolescents and young women that use combination hormonal contraception. Some studies had inherent limitations, such as small trial, poor control of confounders, failure to exclude women with prior use of hormonal contraceptives, or prior pregnancy from control groups. The vast majority of reviewed studies showed OCs containing 20 to 30 µg of EE interfere with acquisition of peak BMD. Limited numbers of studies examine the effects of OCs containing 35 µg on adolescents and young adults. Additionally, studies are needed evaluating the progestin component of OCs as their differing androgenic properties may affect bone mineralization as well.

scholarly journals Conditional disruption of IGF-I gene in type 1α collagen-expressing cells shows an essential role of IGF-I in skeletal anabolic response to loading

2011 ◽  
Vol 301 (6) ◽  
pp. E1191-E1197 ◽  
Author(s):  
Chandrasekhar Kesavan ◽  
Jon E. Wergedal ◽  
K.-H. William Lau ◽  
Subburaman Mohan
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Mechanical Strain ◽  
Bone Size ◽  
Size Difference ◽  
Mineral Density ◽  
Trabecular Thickness ◽  
Bone Response ◽  
Igf I ◽  
I Gene

To establish a causal role for locally produced IGF-I in the mechanical strain response in the bone, we have generated mice with conditional disruption of the insulin-like growth factor (IGF) I gene in type 1α2 collagen-expressing cells using the Cre-loxP approach. At 10 wk of age, loads adjusted to account for bone size difference were applied via four-point bending or axial loading (AL) in mice. Two wk of bending and AL produced significant increases in bone mineral density and bone size at the middiaphysis of wild-type (WT), but not knockout (KO), mice. In addition, AL produced an 8–25% increase in trabecular parameters (bone volume-tissue volume ratio, trabecular thickness, and trabecular bone mineral density) at the secondary spongiosa of WT, but not KO, mice. Histomorphometric analysis at the trabecular site revealed that AL increased osteoid width by 60% and decreased tartrate-resistance acidic phosphatase-labeled surface by 50% in the WT, but not KO, mice. Consistent with the in vivo data, blockade of IGF-I action with inhibitory IGF-binding protein (IGFBP4) in vitro completely abolished the fluid flow stress-induced MC3T3-E1 cell proliferation. One-way ANOVA revealed that expression levels of EFNB1, EFNB2, EFNA2, EphB2, and NR4a3 were different in the loaded bones of WT vs. KO mice and may, in part, be responsible for the increase in bone response to loading in the WT mice. In conclusion, IGF-I expressed in type 1 collagen-producing bone cells is critical for converting mechanical signal to anabolic signal in bone, and other growth factors cannot compensate for the loss of local IGF-I.

Management of bone metabolism in epilepsy

2021 ◽  
Vol 74 (7-8) ◽  
pp. 257-265
Author(s):  
Firdevs Ezgi Uçan Tokuç ◽  
Fatma Genç ◽  
Abidin Erdal ◽  
Yasemin Biçer Gömceli
Keyword(s):  
Bone Mineral Density ◽  
Vitamin D ◽  
Bone Metabolism ◽  
Bone Mineral ◽  
Outpatient Clinic ◽  
Bone Mineralization ◽  
Mineral Density ◽  
Low Bone Mineral Density ◽  
Increased Risk ◽  
Significant Difference

Many systemic problems arise due to the side effects of antiepileptic drugs (AEDs) used in epilepsy patients. Among these adverse effects are low bone mineral density and increased fracture risk due to long-term AED use. Although various studies have supported this association with increased risk in recent years, the length of this process has not been precisely defined and there is no clear consensus on bone density scanning, intervals of screening, and the subject of calcium and vitamin D supplementation. In this study, in accordance with the most current recommendations, our applications and data, including the detection of possible bone mineralization disorders, treatment methods, and recommendations to prevent bone mineralization disorders, were evaluated in epilepsy patients who were followed up at our outpatient clinic. It was aimed to draw attention to the significance of management of bone metabolism carried out with appropriate protocols. Epilepsy patients were followed up at the Antalya Training and Research Hospital Department of Neurology, Epilepsy Outpatient Clinic who were at high risk for osteoporosis (use of valproic acid [VPA] and enzyme-inducing drugs, using any AED for over 5 years, and postmenopausal women) and were evaluated using a screening protocol. According to this protocol, a total of 190 patients suspected of osteoporosis risk were retrospectively evaluated. Four patients were excluded from the study due to secondary osteoporosis. Of the 186 patients who were included in the study, 97 (52.2%) were women and 89 (47.8%) were men. Prevalence of low bone mineral density (BMD) was 42%, in which osteoporosis was detected in 11.8% and osteopenia in 30.6% of the patients. Osteoporosis rate was higher at the young age group (18-45) and this difference was statistically significant (p=0.018). There was no significant difference between male and female sexes according to osteoporosis and osteopenia rates. Patients receiving polytherapy had higher osteoporosis rate and lower BMD compared to patients receiving monotherapy. Comparison of separate drug groups according to osteoporosis rate revealed that osteoporosis rate was highest in patient groups using VPA+ carbamazepine (CBZ) (29.4%) and VPA polytherapy (19.4%). Total of osteopenia and osteoporosis, or low BMD, was highest in VPA polytherapy (VPA+ non-enzyme-inducing AED [NEID]) and CBZ polytherapy (CBZ+NEID) groups, with rates of 58.3% and 55.1%, respectively. In addition, there was no significant difference between drug groups according to bone metabolism markers, vitamin D levels, and osteopenia-osteoporosis rates. Assuming bone health will be affected at an early age in epilepsy patients, providing lifestyle and diet recommendations, avoiding polytherapy including VPA and CBZ when possible, and evaluating bone metabolism at regular intervals are actions that should be applied in routine practice.

The effects of ovariectomy on bone mineral density, geometrical, and biomechanical characteristics in the rabbit femur

2010 ◽  
Vol 23 (01) ◽  
pp. 31-36 ◽  
Author(s):  
M. E. Kara ◽  
F. Sevil
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Animal Studies ◽  
Biomechanical Properties ◽  
Mineral Density ◽  
Cross Sectional ◽  
Tomographic Images ◽  
Three Point Bending ◽  
Rabbit Femur

SummaryThe aim of the study was to evaluate the bone mineral density, as well as the biomechanic and morphometric changes in the femur of ovariectomised rabbits.Twenty-four six-month-old New Zealand rabbits were randomly divided into an ovariectomy (n = 12) and a sham (n = 12) group. Six rabbits in each group were euthanatized at eight and 16 weeks after surgery, and the femora were resected. The morphometric data were obtained from tomographic images. Periosteal and endosteal diameters and cortical thickness were measured. Total cross-sectional, cortical and medullary areas were also measured. The bone mineral content, the bone area and the bone mineral density were measured from the proximal, distal and mid-shaft of the femur as well as the total femur by dual energy X-ray absorptiometry. Employing the three-point bending method, the ultimate force, stiffness and work-to-failure were measured. The mechanical data were normalised to obtain intrinsic biomechanical properties such as ultimate stress, elastic modulus, and toughness, all of which are independent of size and shape.The results indicated that the femur was both larger and weaker 16 weeks after surgery in the ovariectomised group. Results also suggest that the rabbit might be a useful animal model for investigation of diseases related to oestrogen loss such as human postmenopausal osteoporosis. However, additional studies with advanced techniques at several time points via in vivo animal studies, and precision and predictability analyses should be designed to standardise the rabbit as a model for osteoporosis.

scholarly journals Protective effect ofGlycyrrhiza glabraroots extract on bone mineral density of ovariectomized rats

BioMedicine ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 8 ◽  
Author(s):  
Dimitrios Galanis ◽  
Konstantinos Soultanis ◽  
Pavlos Lelovas ◽  
Alexandros Zervas ◽  
Panagiotis Papadopoulos ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Density ◽  
Protective Effect ◽  
Bone Mineral ◽  
Proximal Tibia ◽  
Glycyrrhiza Glabra ◽  
Ovariectomized Rats ◽  
Mineral Density ◽  
Three Point Bending ◽  
Significant Difference

Objective: The aim of this study was to evaluate the potential effect of the methanolic extract of plantGlycyrrhiza glabraroots on bone mineral density and femoral bone strength of ovariectomized rats.Methods: Thirty 10-month-old Wistar rats were randomly separated into three groups of ten, Control, Ovariectomy and Ovariectomy-plus-Glycyrrhiza in their drinking water. Total and proximal tibial bone mineral density was measured in all groups before ovariectomy (baseline) and after 3 and 6 months post ovariectomy. Three-point-bending of the femurs and uterine weight and histology were examined at the end of the study.Results: No significant difference was noted in bone density percentage change of total tibia from baseline to 3 months between Control and Ovariectomy-plus-Glycyrrhiza groups (+5.31% ± 4.75 and +3.30% ± 6.31 respectively,P = non significant), and of proximal tibia accordingly (+5.58% ± 6.92 and +2.61% ± 13.62,P = non significant) demonstrating a strong osteoprotective effect. There was notable difference in percentage change of total tibia from baseline to 6 months between groups Ovariectomy and Ovariectomy-plus-Glycyrrhiza (−13.03% ± 5.11 and −0.84% ± 7.63 respectively,P < 0.005), and of proximal tibia accordingly (−27.9% ± 3.69 and −0.81% ± 14.85 respectively,P < 0.001), confirming the protective effect ofGlycyrrhiza glabraextract in preserving bone density of the Ovariectomy-plus-Glycyrrhiza group. Three-point-bending did not reveal any statistically significant difference between Ovariectomy and Ovariectomy-plus-Glycyrrhiza groups. Uterine weights of the Ovariectomy-plus-Glycyrrhiza group ranged between the other two groups with no statistically significant difference to each.Conclusions:Glycyrrhiza glabraroot extract notably protected tibial bone mineral density loss in Ovariectomy-plus-Glycyrrhiza rats in comparison with ovariectomized rats, but did not improve biomechanical strength.

scholarly journals NADPH Oxidase Contributes to Resistance against Aggregatibacter actinomycetemcomitans-Induced Periodontitis in Mice

2016 ◽  
Vol 85 (2) ◽  
Author(s):  
Antje Bast ◽  
Helen Kubis ◽  
Birte Holtfreter ◽  
Silvia Ribback ◽  
Heiner Martin ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Oral Cavity ◽  
Nadph Oxidase ◽  
Bone Mineral ◽  
Alveolar Bone ◽  
Bone Destruction ◽  
Bone Volume ◽  
Mineral Density ◽  
Content Type

ABSTRACT Aggregatibacter actinomycetemcomitans is a Gram-negative commensal bacterium of the oral cavity which has been associated with the pathogenesis of periodontitis with severe alveolar bone destruction. The role of host factors such as reactive oxygen and nitrogen intermediates in periodontal A. actinomycetemcomitans infection and progression to periodontitis is still ill-defined. Therefore, this study aimed to analyze the role of NADPH oxidase and inducible nitric oxide synthase (iNOS) in a murine model of A. actinomycetemcomitans-induced periodontitis. NADPH oxidase-deficient (gp91phox knockout [KO]), iNOS-deficient (iNOS KO), and C57BL/6 wild-type mice were orally infected with A. actinomycetemcomitans and analyzed for bacterial colonization at various time points. Alveolar bone mineral density and alveolar bone volume were quantified by three-dimensional micro-computed tomography, and the degree of tissue inflammation was calculated by histological analyses. At 5 weeks after infection, A. actinomycetemcomitans persisted at significantly higher levels in the murine oral cavities of infected gp91phox KO mice than in those of iNOS KO and C57BL/6 mice. Concomitantly, alveolar bone mineral density was significantly lower in all three infected groups than in uninfected controls, but with the highest loss of bone density in infected gp91phox KO mice. Only infected gp91phox KO mice revealed significant loss of alveolar bone volume and enhanced inflammatory cell infiltration, as well as an increased number of osteoclasts. Our results indicate that NADPH oxidase is important to control A. actinomycetemcomitans infection in the murine oral cavity and to prevent subsequent alveolar bone destruction and osteoclastogenesis.

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