Quantitative characterization of changes in bone geometry, mineral density and biomechanical properties in two rat strains with different Ah-receptor structures after long-term exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

Spontaneously hypertensive rats (SHR) represent a model of essential hypertension. We studied the effect of amlodipine (AML) on bone markers, bone mineral density (BMD), and biomechanical properties of osteopenic bone induced by orchidectomy in male SHR. Rats were allocated to 3 groups and were sacrificed after 12 weeks: sham-operated control; orchidectomised control; and orchidectomised receiving a diet supplemented with AML. Indicators of bone turnover were assessed in bone homogenate, BMD was measured by dual energy X-ray absorptiometry, and the femurs were subjected to biomechanical testing. Long-term AML administration does not have a negative impact on bone metabolism and density in male SHR.

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Clinical and Radiological Characterization of Patients with Immobilizing and Progressive Stress Fractures in Methotrexate Osteopathy

Calcified Tissue International ◽

10.1007/s00223-020-00765-5 ◽

2020 ◽

Author(s):

Tim Rolvien ◽

Nico Maximilian Jandl ◽

Julian Stürznickel ◽

Frank Timo Beil ◽

Ina Kötter ◽

...

Keyword(s):

Bone Microarchitecture ◽

Cone Beam Ct ◽

Distal Tibia ◽

Stress Fractures ◽

Negative Effects ◽

Mineral Density ◽

Clinical Onset ◽

Teriparatide Treatment

Abstract Methotrexate (MTX) is one of the most commonly prescribed drugs for autoimmune rheumatic diseases. As there is no consensus on its negative effects on bone, the purpose of this investigation was to determine the clinical spectrum of patients with stress fractures due to long-term MTX treatment (i.e., MTX osteopathy). We have retrospectively analyzed data from 34 patients with MTX treatment, severe lower extremity pain and immobilization. MRI scans, bone turnover markers, bone mineral density (DXA) and bone microarchitecture (HR-pQCT) were evaluated. Stress fractures were also imaged with cone beam CT. While the time between clinical onset and diagnosis was prolonged (17.4 ± 8.6 months), the stress fractures had a pathognomonic appearance (i.e., band-/meander-shaped, along the growth plate) and were diagnosed in the distal tibia (53%), the calcaneus (53%), around the knee (62%) and at multiple sites (68%). Skeletal deterioration was expressed by osteoporosis (62%) along with dissociation of low bone formation and increased bone resorption. MTX treatment was discontinued in 27/34 patients, and a combined denosumab–teriparatide treatment initiated. Ten patients re-evaluated at follow-up (2.6 ± 1.5 years) had improved clinically in terms of successful remobilization. Taken together, our findings provide the first in-depth skeletal characterization of patients with pathognomonic stress fractures after long-term MTX treatment.

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Quantitative characterization of mineralized silk film remodeling during long-term osteoblast–osteoclast co-culture

Biomaterials ◽

10.1016/j.biomaterials.2014.01.034 ◽

2014 ◽

Vol 35 (12) ◽

pp. 3794-3802 ◽

Cited By ~ 20

Author(s):

Rebecca S. Hayden ◽

Kyle P. Quinn ◽

Carlo A. Alonzo ◽

Irene Georgakoudi ◽

David L. Kaplan

Keyword(s):

Quantitative Characterization ◽

Silk Film

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Detection and characterization of 63H92,3,7,8-tetrachlorodibenzo-p-dioxin binding to Ah receptor in a rainbow trout hepatoma cell line*1

Toxicology and Applied Pharmacology ◽

10.1016/0041-008x(90)90105-4 ◽

1990 ◽

Vol 106 (1) ◽

pp. 53-62 ◽

Cited By ~ 74

Author(s):

A LORENZEN

Keyword(s):

Rainbow Trout ◽

Cell Line ◽

Hepatoma Cell ◽

Ah Receptor ◽

Hepatoma Cell Line ◽

Tetrachlorodibenzo P Dioxin

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Two models based on local microscopic relaxations to explain long-term basic creep of concrete

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2018.0477 ◽

2018 ◽

Vol 474 (2220) ◽

pp. 20180477 ◽

Cited By ~ 2

Author(s):

Matthieu Vandamme

Keyword(s):

Creep Strain ◽

Basic Creep ◽

Creep Process ◽

Physical Origin ◽

Quantitative Characterization ◽

Disjoining Pressures ◽

Work Hardening Model ◽

Kinetics Of

In this study, we propose an exhaustion model and an adapted work-hardening model to explain the long-term basic creep of concrete. In both models, the macroscopic creep strain originates from local microscopic relaxations. The two models differ in how the activation energies of those relaxations are distributed and evolve during the creep process. With those models, at least up to a few dozen MPa, the applied stress must not modify the rate at which those relaxations occur, but only enables the manifestation of each local microscopic relaxation into an infinitesimal increment of basic creep strain. The two models capture equally well several phenomenological features of the basic creep of concrete. They also make it possible to explain why the indentation technique enables the quantitative characterization of the long-term kinetics of logarithmic creep of cement-based materials orders of magnitude faster than by macroscopic testing. The models hint at a physical origin for the relaxations that is related to disjoining pressures.

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Long-Term Management Policies of Reservoirs: Possible Re-Use of Dredged Sediments for Coastal Nourishment

Water ◽

10.3390/w11010015 ◽

2018 ◽

Vol 11 (1) ◽

pp. 15 ◽

Cited By ~ 13

Author(s):

Annamaria De Vincenzo ◽

Carmine Covelli ◽

Antonio Molino ◽

Marilena Pannone ◽

Margherita Ciccaglione ◽

...

Keyword(s):

Methodological Approach ◽

Beach Sand ◽

Coastal Protection ◽

Quantitative Characterization ◽

Reservoir Sediment ◽

Reservoir Sediments ◽

Management Policies ◽

Term Management

This paper proposes a methodological approach to the re-use of reservoir sediments for coastal nourishment. The proposed approach represents a point of convergence between water and sediment management, coastal protection from erosion and the re-use of sediments dredged from reservoirs. In particular, this study indicates a general protocol of actions and a reference legislative scenario for the use of sediment from reservoirs for beach nourishment as an alternative to sediment from sea caves or land caves. Quantitative characterization of reservoir sediments and their qualitative characterization are the fundamental steps to define the compatibility between reservoir sediment and beach sand. The study was applied to a real case of Southern Italy known as the Guardialfiera Reservoir.

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