scholarly journals Dynamical Modelling of Bone Formation and Resorption under Impulsive Estrogen Supplement: Effects of Parathyroid Hormone and Prolactin

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Supassorn Aekthong ◽  
Chontita Rattanakul
Keyword(s):  
Metabolic Disease ◽  
Parathyroid Hormone ◽  
Theoretical Analysis ◽  
Bone Formation ◽  
Postmenopausal Women ◽  
Computer Simulations ◽  
Impulsive Differential Equations ◽  
System Parameters ◽  
Theoretical Predictions ◽  
The Stability

Osteoporosis, a bone metabolic disease, is one of the major diseases occurring in aging population especially in postmenopausal women. A system of impulsive differential equations is developed in this paper in order to investigate the effects of parathyroid hormone and prolactin on bone-forming cells, namely, osteoblasts, and bone-resorbing cells, namely, osteoclasts, under the impulsive estrogen supplement. The theoretical analysis of the developed model is carried out so that we obtain the conditions on the system parameters in which the stability and permanence of the model can occur. Computer simulations are also provided to illustrate the theoretical predictions.

scholarly journals Effects of Parathyroid Hormone Treatment on Circulating Sclerostin Levels in Postmenopausal Women

2010 ◽  
Vol 95 (11) ◽  
pp. 5056-5062 ◽  
Author(s):  
Matthew T. Drake ◽  
Bhuma Srinivasan ◽  
Ulrike I. Mödder ◽  
James M. Peterson ◽  
Louise K. McCready ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Parathyroid Hormone ◽  
Bone Formation ◽  
Postmenopausal Women ◽  
Animal Studies ◽  
Hormone Treatment ◽  
Research Unit ◽  
Bone Marrow Plasma ◽  
Clinical Research Unit ◽  
Intermittent Pth

Context: Intermittent PTH treatment stimulates bone formation, but the mechanism(s) of this effect remain unclear. Sclerostin is an inhibitor of Wnt signaling, and animal studies have demonstrated that PTH suppresses sclerostin production. Objective: The objective of the study was to test whether intermittent PTH treatment of postmenopausal women alters circulating sclerostin levels. Design: Prospective study. Setting: The study was conducted at a clinical research unit. Participants and Interventions: Participants included 27 postmenopausal women treated with PTH (1-34) for 14 d and 28 control women. Main Outcome Measures: Serum sclerostin levels were measured. Results: Circulating sclerostin levels decreased significantly in the PTH-treated subjects, from (mean ± SEM) 551 ± 32 to 482 ± 31 pg/ml (−12.7%, P < 0.0001) but did not change in the control women (baseline, 559 ± 34 pg/ml; end point, 537 ± 40 pg/ml, P = 0.207; P = 0.017 for difference in changes between groups). Bone marrow plasma was obtained in a subset of the control and PTH-treated subjects (n = 19 each) at the end of the treatment period, and marrow plasma and peripheral serum sclerostin levels were significantly correlated (R = 0.64, P < 0.0001). Marrow plasma sclerostin levels were 24% lower in PTH-treated compared with control women, but perhaps due to the smaller sample size, this difference was not statistically significant (P = 0.173). Conclusions: Circulating sclerostin levels correlate with bone marrow plasma levels and are reduced by intermittent PTH therapy in postmenopausal women. Further studies are needed to assess the extent to which decreases in sclerostin production contribute to the anabolic skeletal response to PTH.

scholarly journals Evaluation of a Fully Automated Serum Assay for Total N-Terminal Propeptide of Type I Collagen in Postmenopausal Osteoporosis

2008 ◽  
Vol 54 (1) ◽  
pp. 188-196 ◽  
Author(s):  
Patrick Garnero ◽  
Philippe Vergnaud ◽  
Nicholas Hoyle
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Postmenopausal Women ◽  
Type I Collagen ◽  
Premenopausal Women ◽  
Type I ◽  
Prognostic Information ◽  
Total N ◽  
Automated Assay ◽  
Anabolic Therapy

Abstract Background: Biochemical markers of bone turnover can provide prognostic information about the risk of fracture and may be useful for monitoring efficacy of antiresorptive and anabolic therapy in osteoporosis. We evaluated the performance of a fully automated assay for serum total N-terminal propeptide of type I collagen (P1NP), a marker of bone formation. Methods: Serum P1NP was measured on the Elecsys 2010 automated analyzer (Roche) in 230 healthy premenopausal women, age 30–49 years, 179 postmenopausal women with osteoporosis participating in the previously published 1 year randomized Parathyroid Hormone and Alendronate for Osteoporosis study of full-length parathyroid hormone (PTH 1-84, >100 μg/day subcutaneously; n = 119) or oral alendronate 10 mg/day (n = 60), and 64 healthy men, age 40 to 65 years. Results: The within-run and between-run (total) imprecision (CVs) were ≤1.7% (n = 20) and 4.4% (n = 15), respectively. The median within-person variability of results (3 measurements over 3 months in 15 postmenopausal women) was 7.2%, resulting in a least significant change (LSC) value of 20%. Serum P1NP concentrations were 74% (P <0.0001) higher in postmenopausal women than in premenopausal controls. After 3 months of treatment, 83% and 88% of patients treated with PTH 1-84 and alendronate, respectively, demonstrated changes of serum P1NP that exceeded the LSC. Conclusion: The automated assay for serum total P1NP is precise and sensitive enough to detect changes that exceed the LSC in a majority of postmenopausal women after 3 months of treatment with PTH 1-84 or alendronate. Because of its convenience and high throughput, this bone formation marker may be useful for the monitoring of patients with osteoporosis

scholarly journals Synchronization and Stability of Two Unbalanced Rotors with Fast Antirotation considering Energy Balance

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Yongjun Hou ◽  
Pan Fang
Keyword(s):  
Energy Balance ◽  
Theoretical Analysis ◽  
Differential Equations ◽  
Computer Simulations ◽  
Stability Criterion ◽  
Induction Motors ◽  
Energy Balance Method ◽  
Analytical Analysis ◽  
The Stability ◽  
Vibrating Systems

We consider synchronization and stability of two unbalanced rotors reversely and fast excited by induction motors fixed on an oscillating body. We explore the energy balance of the system and show how the energy is transferred between the rotors via the oscillating body allowing the implementation of the synchronization of the two rotors. An approximate analytical analysis, energy balance method, allows deriving the synchronization condition, and the stability criterion of the synchronization is deduce by disturbance differential equations. Later, to prove the correctness of the theoretical analysis, many features of the vibrating system are computed and discussed by computer simulations. The proposed method may be useful for analyzing and understanding the mechanism of synchronization, stability, and energy balance of similar fast rotation rotors excited by induction motors in vibrating systems.

scholarly journals Delay-Induced Oscillations in a Competitor-Competitor-Mutualist Lotka-Volterra Model

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Changjin Xu
Keyword(s):  
Hopf Bifurcation ◽  
Normal Form ◽  
Computer Simulations ◽  
Center Manifold ◽  
Volterra Model ◽  
Normal Form Theory ◽  
Biological Meaning ◽  
Theoretical Predictions ◽  
Form Theory ◽  
The Stability

This paper deals with a competitor-competitor-mutualist Lotka-Volterra model. A series of sufficient criteria guaranteeing the stability and the occurrence of Hopf bifurcation for the model are obtained. Several concrete formulae determine the properties of bifurcating periodic solutions by applying the normal form theory and the center manifold principle. Computer simulations are given to support the theoretical predictions. At last, biological meaning and a conclusion are presented.

Parathyroid hormone enhances osteogenesis in a rat model for extraosseous bone formation

1984 ◽  
Vol 104 (4_Supplb) ◽  
pp. S14 ◽  
Author(s):  
J. M. GOTTSWINTER ◽  
H. FLECHTNER ◽  
R. LÖWENSTEIN ◽  
R. ZIEGLER ◽  
G. DELLING
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Rat Model

scholarly journals Multimarker method in the study of laboratory predictors of vascular wall elasticity as the basis for the development of a personalized approach to the treatment of socially significant diseases

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
T Petelina ◽  
K Avdeeva ◽  
N Musikhina ◽  
L Gapon ◽  
S Bykova ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Postmenopausal Women ◽  
Ldl Cholesterol ◽  
Blood Pressure Monitoring ◽  
Vascular Inflammation ◽  
Fold Increase ◽  
Endothelin 1 ◽  
T Score ◽  
Markers Of Inflammation

Abstract Funding Acknowledgements Type of funding sources: None. Aim To investigate the role of markers of vascular inflammation, vitamin D, parathyroid hormone as predictors of increased pulse-wave velocity (PWV) and degenerative bone changes in postmenopausal women with arterial hypertension (AH). Methods 164 females were examined. Gr.1 included 42 healthy individuals, Gr.2 - 58 patients with AH and Gr.3 - 64 postmenopausal women with AH and osteoporosis. Parameters of blood pressure monitoring; PWV, osteodensitometry (T-Score); inflammatory markers: hsCRP, TNFα, homocysteine, IL-1β, 6, 8, endothelin-1; lipid profile parameters; sex and parathyroid hormones, vitamin D  were measured. Results In Gr.3 excess levels of PWV, hsCRP, homocysteine, IL8, total cholesterol, LDL cholesterol, endothelin-1 and parathyroid hormone was detected with decrease in the level of sex hormones and vitamin D. Besides, negative correlations of T-Score with age, PWV, duration of menopause, IL-6, hsCRP were registered; positive correlations between PWV with IL6, LDL cholesterol, hsCRP, endothelin-1, DBP variability were found. The logistic regression method revealed the main markers that affect increase of PWV, such as hsCRP and endothelin-1.Rise of each marker by unit of measurement leads to increase in PWV by 1.3 times and 2.4%, respectively. In Gr.2 increase in PWV level of more than 12.05 m/s was associated with 3.8-fold increase in the risk of osteoporosis. In Gr.3 increase in PWV level on 1 m/s was associated with 6 fold increase in the risk of osteoporosis. Conclusions Elevated levels of PWV are associated with markers of inflammation, levels of parathyroid hormone, vitamin D, T-Score and may be part of the pathogenesis of the cardiovascular continuum in postmenopausal women, which will require an individual approach to the treatment of AH with comorbid metabolic disorders.

scholarly journals SLPI is a critical mediator that controls PTH-induced bone formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Akito Morimoto ◽  
Junichi Kikuta ◽  
Keizo Nishikawa ◽  
Takao Sudo ◽  
Maki Uenaka ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Formation ◽  
Protease Inhibitor ◽  
Bone Metabolism ◽  
Serine Protease ◽  
Serine Protease Inhibitor ◽  
Secretory Leukocyte Protease Inhibitor ◽  
Bone Imaging ◽  
Genetic Ablation

AbstractOsteoclastic bone resorption and osteoblastic bone formation/replenishment are closely coupled in bone metabolism. Anabolic parathyroid hormone (PTH), which is commonly used for treating osteoporosis, shifts the balance from osteoclastic to osteoblastic, although it is unclear how these cells are coordinately regulated by PTH. Here, we identify a serine protease inhibitor, secretory leukocyte protease inhibitor (SLPI), as a critical mediator that is involved in the PTH-mediated shift to the osteoblastic phase. Slpi is highly upregulated in osteoblasts by PTH, while genetic ablation of Slpi severely impairs PTH-induced bone formation. Slpi induction in osteoblasts enhances its differentiation, and increases osteoblast–osteoclast contact, thereby suppressing osteoclastic function. Intravital bone imaging reveals that the PTH-mediated association between osteoblasts and osteoclasts is disrupted in the absence of SLPI. Collectively, these results demonstrate that SLPI regulates the communication between osteoblasts and osteoclasts to promote PTH-induced bone anabolism.

Polydomain Structure of Epitaxial PbTiO3 films on MgO

1997 ◽  
Vol 493 ◽  
Author(s):  
S. P. Alpay ◽  
A. S. Prakash ◽  
S. Aggarwal ◽  
R. Ramesh ◽  
A. L. Roytburd ◽  
...  
Keyword(s):  
Domain Structure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Theoretical Predictions ◽  
The Stability ◽  
Increasing Temperature ◽  
Stable Domains ◽  
Domain Stability

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.

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