Bone Abstracts

Antiresorptives consistently improve bone mass and structural strength in normally- and under-loaded bones, but concerns have been raised regarding potential effects on skeletal adaptation to fatigue loading, including damage accumulation and atypical fractures. We thus inhibited or activated osteoclasts with OPG-Fc or RANKL treatment, respectively, and evaluated bone damage and strength after fatigue in the early and later phases of repair. Adult male mice were treated with R...

Classical osteogenesis imperfecta (OI) is caused by mutations in the two genes encoding type I collagen. OI is associated with low bone mass and abnormally high bone matrix mineralization. The Brtl/+ OI mouse is a knock-in model caused by a glycine substitution in one COL1A1 allele. Brtl/+ pups display 30% perinatal lethality; survivors have small size and brittle bone. Unexpectedly, homozygous Brtl/Brtl pups, producing only mutant collagen, have normal survival rates...

Diabetes mellitus results in increased skeletal fragility through reduced bone mineral density and altered collagen structure. How these changes affect bone mechanics at the tissue level remains largely unclear. Anti-osteoporosis medications improve bone mass, but whether they can fully restore tissue strength in diabetic bone, where collagen quality is compromised, has not been fully elucidated. The objective of this study was to determine the effect of type 2 diabetes mellit...

The local mechanical properties of bone are influenced not only by the material chemical composition but also by the spatial arrangement of the component’s e.g. orientation of collagen matrix. However, not much is known about local elastic modulus variations in cortical bone. Our goal was to use acoustic imaging to map elastic properties of murine bone with a several microns resolution. Rodent long bones exhibit a permanent growth with endosteal/periosteal bone formation ...

It has long been known that osteoarthritis induces dramatic structural changes in subchondral bone. Studies on patients’ biopsies have also shown that the new sclerotic bone is hypomineralized and has decreased elastic modulus. Due to their amenability for genetic studies, murine models of OA are particularly important for drug target discovery. However, whilst osteosclerosis has been reported also in murine OA models, little is known about the compositional and mechanica...

Hip fracture rate in Norway is the highest registered in World, and more than double that of Spanish women. Previous studies were unable to demonstrate significant differences between the two populations with respect to bone mass or calcium metabolism. In order to test, whether the difference in fracture propensity between both populations could be explained by differences in bone material quality we assessed bone material strength using microindentation in 41 Norwegian and 46...

Menopause is accompanied by a decrease in bone mineral density which can be caused by a reduction in bone volume and/or degree of bone matrix mineralization. Both of them are suggested to contribute to the increased fracture risk in postmenopausal individuals. In the present work, we aimed for information whether a drop in bone matrix mineralization is occurring in the perimenopausal stage of women. For this purpose, we measured the bone mineralization density distribution (BM...

Dysfunctions of Wnt/β-catenin and estrogen receptor signalling resulted in impaired mechanotransduction and bone loss as in osteoporosis. Previous studies demonstrated the interaction of these pathways in mechanotransduction in vitro and in vivo. In this study, the influence of the activation of estrogen receptor and β-catenin signalling on mechanically induced bone formation was investigated in ovariectomized mice. 12-week-old mice were ovariectomi...

Objectives: A role for glucose-dependent insulinotropic polypeptide (GIP) in controlling bone mass and strength has previously been reported. However, the rapid degradation of GIP in the bloodstream by the dipeptidyl peptidase-4 enzyme precludes therapeutic use. To circumvent this problem, a series of N-terminally modified GIP agonists have been developed. The aim of the present study was to investigate the effects of 28-day treatment with N-AcGIP on bone microarchitecture and...

Chronic obstructive pulmonary disease (COPD) has been found associated with low areal bone mineral density and an increase in fracture rate. Previous histomorphometric findings revealed abnormally low cancellous bone volume and thin cortices. In the present work, we studied the same transiliac bone biopsy samples from n=19 COPD patients for cancellous (Cn.) and cortical (Ct.) bone mineralization density distribution (BMDD) based on quantitative backscatter electron im...

In type 2 diabetes mellitus (T2DM) patients, an increased fracture risk is observed, although the bone mineral density is even higher than in non-diabetic patients, which raises the question of the quality of the organic and inorganic matrix in bone1,2. T2DM is also known to favor inflammation of the gingiva and paradontosis in general. However, little is known about the mineral nano-architecture in the mandible and about the possible influence of diabetes. Using sy...

The cathepsin K inhibitor odanacatib (ODN) is a bone formation-sparing inhibitor of osteoclastic resorption activity. This drug is currently under development for the treatment of postmenopausal osteoporosis. To support the bone safety profile of ODN, we evaluated the effects of ODN on trabecular bone hard tissue properties in the estrogen-deficient model of the ovariectomized (OVX) rhesus monkeys. Animals (n=16/group, age 11–22 years) were treated immediately af...

Objective: We investigated the effect of creatine administered in the diet for 10 weeks on bone turnover and bone quality in male Wistar rats.Methods: Rats were divided (after approval of Ethical committee 9814/2008–30 and 30793/2010–30) into four groups, ten animals in each group. G1 SLD-A group were fed a standard laboratory diet (SLD). G2 SLD-B group were fed SLD and 12 h before rats were sacrificed diet was removed. G3...

The objective of the study was to investigate whether the anti-resorptive and bone-forming dual effect of Strontium Ranelate (SrR) influences the healing of a non-critical sized femoral mid-shaft bone defect.Sixty 16-weeks-old female Wistar rats were randomized into four groups. Cylindrical defects with a diameter of 2 mm was drilled through the anterior cortex of both right and left femoral mid-shafts. Two groups were treated with SrR (900 mg/kg/day) mi...

Osteoporosis is a multifactorial disease that represents an increase public health problem, given the impact on functional independence and quality of life. Among the favoring factors to the imbalance in bone cell activity, the hypoestrogenism is primordial. Strength training (ST) proves to be effective because of its ability to stimulate estrogen receptor independent of ligand. In this study, we analyzed the action of ST on bone quality of rats during the aging. For this stud...

The purpose of this study was to analyze the influence of diet supplemented with hydrosoluble soy extract – HSE in bone mass of male and healthy Wistar rats. Sixteen (16) 30 days old animals were kept in controlled conditions with light/dark cicle and fed with commercial food and filtered water. Randomized into two groups: control group received 500 ml of water and 300 g of food, daily; supplemented group S, in addition of water and food, they also received 500 ml of soy ...

Objective: We investigated the effect of arginine administered for 10 weeks in diet on bone metabolism in male Wistar rats.Methods: Rats were divided (after approval of Ethical Committee 9814/2008-30 and 30793/2010-30) into four groups, ten animals in each group: G1 SLD-S group were fed a standard laboratory diet (SLD). G2 SLD-H group were fed SLD and 12 h before rats were sacrificed diet was removed. G3 ARG-S group was fed wit...

The aim of the study was to evaluate relationships between morphometric, densitometric and mechanical properties of tarsometatarsus in ostriches (Struthio camelus). Males (n=9) and females (n=15) were kept to slaughter age of 14 months of life to obtain left tarsometatarsus. Using computed tomography technique (Somatom Emotion, Siemens), volumetric bone mineral density (vBMD) of the trabecular (Td) and cortical bone (Cd) were measured. Areal BMD and ...

The bioapatite crystals have a multilayer hydrate shell, which contains impurity ions such as magnesium, sodium, potassium and it is not clear the qualitative and quantitative characteristics of noapatite entourage. The major component noapatite environment in bone is water and we studied the surface of nanocrystals from trabecular bone in healthy rats and during the water deficiency.In experiment we use adult laboratory rats (8 months age), remove the c...

Aim: Investigate strength features of humerus in rats with defects in tibiae after 60-day per os administration of sodium benzoate (SB).Materials and methods: The experiment involved 210 rats with initial body weight of 200–210 g. The animals were separated into six groups as follows: Group 1 comprised animals that received per os 1 ml of 0.9% solution of sodium chloride daily (C), Group 2 (D) comprised animals with plain defects o...

Two kinds of apatite powder were prepared separately from bovine bones originated from different geographical and ecological areas with different climates, in order to characterize and compare their components, hardness and structures by burning them and heat treating the bone ashes at 850 °C in an air furnace. The black ashes were converted to white and yellow–white powders. X-ray diffraction (XRD) analysis indicate that the white powder was carbonate–hydr...

Children with osteogenesis imperfecta (OI) still suffer from frequent fractures, despite bisphosphonate treatment. Thus new therapeutic approaches are needed. Sclerostin is a protein that is thought to inhibit bone formation. Treatment with sclerostin antibodies (SclAB) increases bone mass in animal models and in clinical trials and may be a rational therapy for OI as well.Transgenic (TgOI) Col1a1Jrt/+ mice were gene...