Bone adaptation compensates resorption when sciatic neurectomy is followed by low magnitude induced loading

Bone ◽  
2019 ◽  
Vol 120 ◽  
pp. 487-494 ◽  
Author(s):  
Judith Piet ◽  
Dorothy Hu ◽  
Roland Baron ◽  
Sandra J. Shefelbine
Keyword(s):  
Bone Adaptation ◽  
Sciatic Neurectomy ◽  
Low Magnitude

scholarly journals TRABECULAR BONE ADAPTATION TO LOW-MAGNITUDE HIGH-FREQUENCY LOADING AT MICRO-GRAVITY

2012 ◽  
Vol 45 ◽  
pp. S531
Author(s):  
Antonia Torcasio ◽  
Katharina Jähn ◽  
Maarten Van Guyse ◽  
Pieter Spaepen ◽  
Andrea E. Tami ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
High Frequency ◽  
Bone Adaptation ◽  
Micro Gravity ◽  
Low Magnitude

scholarly journals Trabecular Bone Adaptation to Low-Magnitude High-Frequency Loading in Microgravity

PLoS ONE ◽  
2014 ◽  
Vol 9 (5) ◽  
pp. e93527 ◽  
Author(s):  
Antonia Torcasio ◽  
Katharina Jähn ◽  
Maarten Van Guyse ◽  
Pieter Spaepen ◽  
Andrea E. Tami ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
High Frequency ◽  
Bone Adaptation ◽  
Low Magnitude

The effect of low magnitude mechanical stimulation (LMMS) on bone density in patients with Rett syndrome: A pilot and feasibility study

2014 ◽  
Vol 7 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Sarah Y. Afzal ◽  
Anna R. Wender ◽  
Mary D. Jones ◽  
Ellen B. Fung ◽  
Elaine L. Pico
Keyword(s):  
Bone Density ◽  
Rett Syndrome ◽  
Feasibility Study ◽  
Mechanical Stimulation ◽  
Low Magnitude

scholarly journals Interleukin-1β Induced Matrix Metalloproteinase Expression in Human Periodontal Ligament-Derived Mesenchymal Stromal Cells under In Vitro Simulated Static Orthodontic Forces

2021 ◽  
Vol 22 (3) ◽  
pp. 1027
Author(s):  
Christian Behm ◽  
Michael Nemec ◽  
Alice Blufstein ◽  
Maria Schubert ◽  
Xiaohui Rausch-Fan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Periodontal Ligament ◽  
Induced Expression ◽  
Gene And Protein Expression ◽  
Tensile Strains ◽  
Orthodontic Forces ◽  
Low Magnitude

The periodontal ligament (PDL) responds to applied orthodontic forces by extracellular matrix (ECM) remodeling, in which human periodontal ligament-derived mesenchymal stromal cells (hPDL-MSCs) are largely involved by producing matrix metalloproteinases (MMPs) and their local inhibitors (TIMPs). Apart from orthodontic forces, the synthesis of MMPs and TIMPs is influenced by the aseptic inflammation occurring during orthodontic treatment. Interleukin (IL)-1β is one of the most abundant inflammatory mediators in this process and crucially affects the expression of MMPs and TIMPs in the presence of cyclic low-magnitude orthodontic tensile forces. In this study we aimed to investigate, for the first time, how IL-1β induced expression of MMPs, TIMPs and how IL-1β in hPDL-MSCs was changed after applying in vitro low-magnitude orthodontic tensile strains in a static application mode. Hence, primary hPDL-MSCs were stimulated with IL-1β in combination with static tensile strains (STS) with 6% elongation. After 6- and 24 h, MMP-1, MMP-2, TIMP-1 and IL-1β expression levels were measured. STS alone had no influence on the basal expression of investigated target genes, whereas IL-1β caused increased expression of these genes. In combination, they increased the gene and protein expression of MMP-1 and the gene expression of MMP-2 after 24 h. After 6 h, STS reduced IL-1β-induced MMP-1 synthesis and MMP-2 gene expression. IL-1β-induced TIMP-1 gene expression was decreased by STS after 6- and 24-h. At both time points, the IL-1β-induced gene expression of IL-1β was increased. Additionally, this study showed that fetal bovine serum (FBS) caused an overall suppression of IL-1β-induced expression of MMP-1, MMP-2 and TIMP-1. Further, it caused lower or opposite effects of STS on IL-1β-induced expression. These observations suggest that low-magnitude orthodontic tensile strains may favor a more inflammatory and destructive response of hPDL-MSCs when using a static application form and that this response is highly influenced by the presence of FBS in vitro.

Study of low-magnitude seismic events near the Novaya Zemlya nuclear test site

1997 ◽  
Vol 87 (6) ◽  
pp. 1563-1575
Author(s):  
Frode Ringdal
Keyword(s):  
Monitoring Network ◽  
Test Site ◽  
Nuclear Test ◽  
P Wave ◽  
Scaling Effects ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Novaya Zemlya ◽  
Source Scaling ◽  
Low Magnitude

Abstract A study of available seismic data shows that all but one of the 42 known underground nuclear explosions at Novaya Zemlya have been detected and located by stations in the global seismic network. During the past 30 years, only one seismic event in this area has been unambiguously classified as an earthquake (1 August 1986, mb = 4.3). Several other small events, most of which are thought to be either chemical explosions or aftereffects of nuclear explosions, have also been detected. Since 1990, a network of sensitive regional arrays has been installed in northern Europe in preparation for the global seismic monitoring network under a comprehensive nuclear test ban treaty (CTBT). This regional network has provided a detection capability for Novaya Zemlya that is shown to be close to mb = 2.5. Three low-magnitude events have been detected and located during this period, as discussed in this article: 31 December 1992 (mb = 2.7), 13 June 1995 (mb = 3.5), and 13 January 1996 (mb = 2.4). To classify the source types of these events has proved very difficult. Thus, even for the mb = 3.5 event in 1995, we have been unable to provide a confident classification of the source as either an earthquake or explosion using the available discriminants. A study of mb magnitude in different frequency bands shows, as expected, that the calculation of mb at regional distances needs to take into account source-scaling effects at high frequencies. Thus, when comparing a 4 to 8 or 8 to 16 Hz filter band to a “teleseismic” 2 to 4 Hz band, the smaller events have, relatively speaking, significantly more high-frequency energy (up to 0.5 mb units) than the larger events. This suggests that a P-wave spectral magnitude scale might be appropriate. The problem of accurately locating small events using a sparse array network is addressed using the 13 January 1996 event, which was detected by only two arrays, as an illustrative example. Our analysis demonstrates the importance of using accurately calibrated regional travel-time curves and, at the same time, illustrates how array processing can be used to identify an interfering phase from a local disturbance, thereby avoiding location errors due to erroneous phase readings.

An Improved In Vivo Rat Tail Vertebra Model for the Study of Trabecular Bone Adaptation

1999 ◽  
Author(s):  
Mark J. Eichler ◽  
Chi Hyun Kim ◽  
X. Edward Guo
Keyword(s):  
Trabecular Bone ◽  
Large Scale ◽  
Bone Fractures ◽  
Mechanical Load ◽  
Bone Adaptation ◽  
Surgical Trauma ◽  
Micro Computed Tomography ◽  
Age Related ◽  
Rat Tail

Abstract The role of mechanical loading in trabecular bone adaptation is important for the understanding of bone integrity in different loading scenarios such as microgravity and for the etiology of age-related bone fractures. There have been numerous in vivo animal studies of bone adaptation, most of which are related to cortical bone remodeling, aimed at the investigation of Wolff’s Law [4], An interesting experimental model for trabecular bone adaptation has been developed in the rat tail vertebrae [2,3]. This model is attractive for trabecular bone adaptation studies because a controlled mechanical load can be applied to a whole vertebra with minimal surgical trauma, using a relatively inexpensive animal model. In addition, with advanced micro computed tomography (micro-CT) or micro magnetic resonance imaging (micro-MRI) coupled with large scale finite element modeling techniques, it is possible to characterize the three-dimensional (3D) stress/strain environment in the bone tissue close to a cellular level (∼25μm) [1]. Therefore, this in vivo rat tail model has a tremendous potential for quantification of the relationship between mechanical stimulation and biological response in trabecular bone adaptation.

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