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1

Ochratoxin A and Aflatoxin B1 as Factors of Bone Damage and Neurodegeneration Through the Influence on the Immunomodulation Processes of TNF-α and IL-6 Concentrations

Radzka-Pogoda Agnieszka, Radzki Radosław Piotr, Bieńko Marek, Szponar Jarosław, Sokołowska Barbara, Kulik Anna, Lewicka Małgorzata, Borzęcki Andrzej

Polish Hyperbaric Research

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2022

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nr 3(80)

61--72

EN

The wide distribution of mycotoxins, including aflatoxin B1 and ochratoxin A, in the environment and their influence on living organisms make them an interesting research problem. Numerous complications of intoxication with these substances are known, however, particular attention is paid to the effects on the skeletal and nervous systems. The inflammatory effect, presented by the increase in the concentration of cytokines - IL-6 and TNF-α may influence the immune dysregulation present in bone metabolism disorders, as well as in neurodegeneration. Mycotoxins also contribute to osteodegeneration by modifying vitamin D metabolism. Interestingly, and still unexplored, is the mechanism of intrauterine influence on bone metabolism and neurodegeneration processes. Understanding the above mechanisms may help in monitoring the toxic effects of intoxication with these toxins. It can also help develop methods of therapy for poisoning with this compound, in animals and humans.

2

Using X-ray diffraction in characterization of bone remodeling and nanocomposites in ovariectomized rats osteopenia model

Kostyshyn Nazar, Gzhegotskyi Mechyslav, Kostyshyn Liubov, Yarova Oksana, Kulyk Yuriy, Mudry Stepan

Polish Journal of Medical Physics and Engineering

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2021

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Vol. 27, Iss. 2

157--163

EN

Sedentary lifestyle and physiological menopause are among the risk factors of osteopenia, especially in elderly people. However, bone mineral density decrease can also be observed in young individuals, for instance, due to deficiency of female sex hormones after surgical interventions, particularly ovariectomy. Our research enabled us to assess the efficacy of whole-body vibration in preventing the loss of bone mineral density in the ovariectomy rat osteopenia model. Thus, whole-body vibration with acceleration level 0.3 g and frequency 50 Hz was used on young female rats, which had been subjected to ovariectomy (n = 18). It had been conducted for 24 weeks, exposure time – 30 minutes per day, 5 times a week. Assessment of mineral component loss of the tibia was performed by means of X-ray diffraction. Bone remodeling was assessed by determining hormones: parathyroid hormone and calcitonin, Ca and P in the blood. X-ray diffraction is an effective method, which enables the evaluation a nanocomposites structure of the bone tissue in the experiment. In the article, we applied this method to determine the loss of bone mineral mass after ovariectomy and the impact of wholebody vibration under such conditions. In the ovariectomy group, the volume of a mineral component significantly decreased starting already from the 16th week (р<0.05) versus control. However, in the group with ovariectomy + wholebody vibration, the loss of a mineral component was insignificant during 8-16 weeks of the investigation, compared with the control group. On the 24th day, the spectrums almost did not differ from ovariectomized rats group. Meanwhile, hormone levels changed in ovariectomized rats group. It should be emphasized that the aforementioned whole-body vibration parameters do not cause severe bone damage or further negative consequences.

3

Effect of the material’s stiffness on stress-shielding in osseointegrated implants for bone-anchored prostheses: a numerical analysis and initial benchmark data

Prochor Piotr

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 2

69--81

EN

This study attempted to establish the link between design of implants for bone-anchored prostheses and stress-shielding, affecting the stability of the bone-implant coupling using numerical approach. The objectives were to share a numerical model capable to evaluate the long-term stability of implants and to use this model to extract data sets showing how shape and material stiffness of threaded, press-fit and modular press-fit implants affect stress-shielding intensity. Methods: Three designs were considered: threaded, press-fit and modular press-fit. The effect of shape and material stiffness of each design on stress-shielding intensity was assessed using Young’s modulus (10 to 210 GPa). Furthermore, the impact of the diameter of percutaneous part (10 to 18 mm) and thickness of medullar part (5 to 1 mm) was investigated for the modular press-fit implant. Results: The threaded design generated 4% more bone mass loss at the distal femur but an overall loss of bone mass was by 5% lower to press-fit design. The influence of Young’s modulus on bone mass changes was noticeable for modular press-fit implant, depending on diameter of percutaneous or medullary part. A 20 GPa change of stiffness caused a bone mass change from 0.65% up to 2.45% and from 0.07% up to 0.32% for percutaneous parts with 18 mm and 10 mm diameter, respectively. Conclusions: Results suggested that threaded implant provides greater stability despite an increased bone loss at the distal femur. Altogether, this work provided an initial model that could be applied in subsequent studies on the long-term stability of current and upcoming implants.

4

The role of the bone strength on the cyst growth in the mandible

Miodowska Justyna, Bielski Jan, Kromka-Szydek Magdalena

Engineering Transactions

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2019

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Vol. 67, iss. 3

293--300

EN

Intracystic fluid pressure is discussed as a potentially important factor influencing a bone cyst growth. This process can develop in the course of months. However, the exact mechanism remains speculative. In this paper, we use an established mathematical model to evaluate whether the presence of pressurized fluid in bone cavities may result in cyst growth. A continuous function of bone density rate vs. mechanical stimulus is used. The numerical model of the mandible with the cyst is used to predict the stress-stimulated change in bone density around the cavity.

5

Variable order 3D models of bone remodelling

Valério D., Neto J., Vinga S.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 3

501--508

EN

This paper presents simulations of a three-dimensional model of the bone remodelling process. The model consists of a set of variable order partial differential equations, in which the varying order depends on the presence of tumour cells. The simulations are of a two-dimensional bone, to make visualisation simpler. They show that this model corresponds to the known evolution of bone remodelling, and is simpler than integer order models found in the literature.

6

A new model of bone remodelling

Miodowska J., Bielski J., Kromka-Szydek M.

Engineering Transactions

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2016

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Vol. 64, iss. 4

605--611

EN

The objective of this paper is to propose a mathematical model of bone remodelling, including underload and overload resorption, equilibrium and bone grow states which can occur during healing process. A continuous function of bone density rate vs. mechanical stimulus is proposed. The created model is used to predict the stress-stimulated change in callus density. It is an extension of mathematical descriptions available in literature.

7

Bone Remodelling Model Incorporating Both Shape and Internal Structure Changes by Three Different Reconstruction Mechanisms. A Lumbar Spine Case

Wymysłowski P., Zagrajek T.

Archive of Mechanical Engineering

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2016

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Vol. LXIII, nr 4

549--563

EN

The paper presents a method of analysis of bone remodelling in the vicinity of implants. The authors aimed at building a model and numerical procedures which may be used as a tool in the prosthesis design process. The model proposed by the authors is based on the theory of adaptive elasticity and the lazy zone concept. It takes into consideration not only changes of the internal structure of the tissue (described by apparent density) but also surface remodelling and changes caused by the effects revealing some features of “creep”. Finite element analysis of a lumbar spinal segment with an artificial intervertebral disc was performed by means of the Ansys system with custom APDL code. The algorithms were in two variants: the so-called site-independent and site-specific. Resultant density distribution and modified shape of the vertebra are compared for both of them. It is shown that this two approaches predict the bone remodelling in different ways. A comparison with available clinical outcomes is also presented and similarities to the numerical results are pointed out.

PL

Artykuł prezentuje metodę analizy przebudowy kości w otoczeniu implantów. Celem pracy było opracowanie modelu i procedur numerycznych mogących służyć jako narzędzie wspomagające projektowanie protez. Zaproponowany przez autorów model opiera się na teorii adaptacyjnej sprężystości i koncepcji strefy martwej. Uwzględnia on nie tylko zmiany struktury wewnętrznej tkanki (opisanej przez gęstość pozorną), ale także przebudowę powierzchniową i zmiany związane z efektami wykazującymi pewne cechy “pełzania”. Przeprowadzona została analiza metodą elementów skończonych segmentu ruchowego kręgosłupa ze sztucznym krążkiem międzykręgowym z wykorzystaniem systemu Ansys i własnego kodu APDL. Algorytmy zbudowano w dwóch wariantach: tzw. niezależnym i zależnym od miejsca. Porównano uzyskane rozkłady gęstości i zmiany kształtu pokazując, że obydwa warianty przebudowę kości przewidują w różny sposób. Zaprezentowano również porównanie wyników numerycznych z badaniami klinicznymi wskazując na ich podobieństwa.

8

Functionalized nanotubular oxide layer on Ti6Al4V as a regulator and biosensor of bone tissue remodeling

Kaczmarek-Pawelska A., Krasicka-Cydzik E.

Archives of Materials Science and Engineering

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2015

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Vol. 73, nr 2

53--61

EN

Purpose: Our aim was to obtain functionalized nanotubular oxide layer (TNTs) on Ti6Al4V alloy and evaluate its efficiency as a platform for electrochemical biosensor of bone remodeling markers. It was also crucial to examinate does the amount of bonded bALP and BMP-2 and antibodies depends from nanotubes diameter and their electrochemical properties. Design/methodology/approach: The antibody specific for bALP and BMP-2 were used to functionalize the TNTs on Ti6Al4V. The spectrophotometry and electrochemical measurements (CV and EIS) were used to examinate the functionalization efficiency and comfirmed sensing properties of the functionalized TNTs on Ti6Al4V alloy. Findings: The obtained results confirmed that TNTs can strongly bind antibodies by physioabsorption and may be a proper platform for biosensing of the selected markers. The protein immobilization efficiency depends over the nanotube diameter and their electrical charge. Thermally modified TNTs with 50 nm diameter on Ti6Al4V strongly bind bALP antibodies and bALP and it can be detected amperometrically. BMP-2 quantitatively binds to the functionalized non annealed charged TNTs with 100 nm diameter, and it is possible to detect it using EIS. Research limitations/implications: The biosensors presented in this work are simple and fast, but this construction is a prototype and need to be optimized to be used in bone remodelling diagnostics. Practical implications: Development of the functionalized TNTs on the Ti6Al4V sensitive for physiological concentrations of the bone remodelling markers may be alternative for immunotests in diagnostic of bone diseases. Moreover the TNTs morphology generates nano roughness over the Ti6Al4V surface and functionalized by antibodies strongly bind bALP or BMP-2 and stimulate bone proliferation. Originality/value: Unique value of this research is the statement the amount of bonded markers and antibodies depends from TNTs diameter and electrochemical properties, and that the prototype of novel biosensor electrode was developed.

9

The meaning of the piezoelectric and streaming potential in bone remodeling

Lech Ł., Iwaniec M.

Vibrations in Physical Systems

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2010

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Vol. 24

251--258

EN

In this paper authors include the most important information about piezoelectric effect and streaming potential occurring in bone. In their opinion these phenomena play important role during bone remodeling, so that model binding them together was proposed. Model describes mechanisms responsible for “sensing” by osteocyteslocal changes in stresses and strains and for signal transmissions from sensors to effectors i.e. osteoblasts.

PL

W pracy tej zawarto najważniejsze informacje dotyczące występowania efektu piezoelektrycznego oraz potencjału przepływu w strukturach kostnych, które zdaniem autorów tego tekstu, ma odgrywa ważną rolę przy przebudowie tkanki kostnej. Dlatego został zaproponowany model odbierania sygnałów o stanie mechanicznym kości przez osteocyty i powiązany z modelem oddziaływań międzykomórkowych opisującym przekazywanie informacji z osteocytów do osteoblastów.

10

Study and improvement of a trapezium-metacarpal prosthesis in relationship with the bone remodeling phenomena

Lamblin D., Guerlement G., Van Parys L., Datoussaid S.

Computer Assisted Mechanics and Engineering Sciences

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2006

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Vol. 13, No. 4

583-592

EN

Simulation of the long term behavior of a metacarpal bonę with a prosthesis is presented with the help of an evolutive 3D finite element model taking into account "the stress słiielding" phenomena. The same model allows to improve the shape of the prosthesis.

11

Mechanical reason of femoral bone tissue remodelling - an attempt of problem approach

Okrajni J., Jasik A.

Journal of Medical Informatics & Technologies

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2002

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Vol. 4

MT19--25

EN

The paper presents the analysis of mechanical properties of human hip joint bone behaviour basing on the finite elements methods (FEM). Models of a hip joint have been worked out. Stress patterns in these biomechanical systems have been determined. The examination covers the analysis of stress patterns in elaborated models for given examples of a femoral bone loading in respective walking phases. It has been stated that prediction of bone remodelling could be based on methods applied in mechanics of materials and data of a bone mineral content and bone mineral density determined by the densitometry method. The work is an attempt of the bone tissue assessment criterion approach useful in implantology problems in which the bone tissue density depends on the bone loading.

12

On a class of bone cell-based remodelling laws with spatial fading influence of stimuli

Lekszycki T.

Engineering Transactions

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2001

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Vol.49, iss.2/3

155-164

EN

In the present paper the elms of cell-based bone remodeling laws is considered. The fundamental assumption is that of fading in space influence on actor cells osteocytes functioning as sensors. The actor cells - osteoblasts and osteoclasts are responsible for the changes of bone micro-structure. The model proposed in the previous publications of other authors, is based on the resumption of exponential influence function and density of strain energy as the stimulus to which the osteocytes are sensitive, see [11, 12, 14]. As the result of the adaptation according to such remodeling law the porous material is created. The topology of the micro-structure of this material is dependent on the mechanical loading conditions and the characteristics of the interactions of cells. The aim of the present work was to examine if this phenomenon is characteristic only for this specific law or represents a rather general property associated with the hypothesis of fading influence of the cells. Different influence functions were examined for different functionals selected to represent the stimulus. It follows from the these considerations that the fading influence of the cells plays fundamental role for the remodeling process and the creation of trabecular structure. Such structures were obtained for several adaptation laws based on different influence functions and functionals representing the stimulus. They were compared with the results obtained for the adaptation law proposed and discussed in [11, 12, 14]. The numerical calculations suggest that the idea of spatial fading influence of the cells can be possibly combined in future with the results of the research on the biological mechanisms of the bone remodeling to propose more sophisticated models

13

An analysis of the theories in biomechanics

Prendergast P. J.

Engineering Transactions

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2001

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Vol.49, iss.2/3

117-133

EN

The nature of the systems commonly thought of as coming into the remit of biomechanics range from 'mechanical' systems (concerned with the design of medical devices, such as implants) to 'mechanobiological' systems (concerned with the response of tissues, cells, and biomolecules to mechanical forces). In each case, a biomechanical system is characterised by the interaction of biological and physical elements. Like any other science, biomechanics advances by the development of theories and the testing of these theories by observation and experiment. The purpose of this paper is to analyse contemporary biomechanics research by providing a critique of the development of biomechanical theories. Only two are considered in detail: (i) the theory of hip prosthesis failure and (ii) the theory of adaptive-bone remodelling. In both cases, specific basic statements, or hypotheses, have been proposed and tested using computational and experimental methods. In the case of hip implants, there have been definite advances in the sense that many hypotheses that could have been rejected continue to be upheld despite severe testing. On the other hand, in the case of adaptive-bone remodelling where the dominant theory is 'adaptive elasticity', the tests of the theory have either been too lenient or they have smuggled in new assumptions that fundamentally alter it. The problems of testing adaptive-elasticity theory are described, and comparison is made with damage-based bone remodelling theories.

14

Principles of bone remodelling - the limit cycles of bone remodelling

Petrtyl M., Danešová J.

Acta of Bioengineering and Biomechanics

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2001

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Vol. 3, nr 1

75-91

EN

The bone tissue remodelling is a relatively slow process. In physiologically "normal" conditions, it tends towards the state of remodelling equilibrium. In the state of final remodelling equilibrium, the strain energy reaches its minimum. In the life of each human being, the bone tissue passes through the repeating limit cycles of its development, functioning and destruction. The paper presented is aimed at the biomechanochemical processes within one limit cycle of bone remodelling using the stoichiometric equations and kinetic equations. Each limit cycle of the bone tissue remodelling (in its assumed volume element) consists of several stages, in which the biochemical reactions are proceeding in a highly intensive way, and of several periods in which the tissue is in weakly steady states (i.e.. the biochemical reactions are very slow or they almost do not take place). Generally, throughout the life of a human, a bone tissue is several times in the principal weakly steady state, i.e., in such a state in which the long-term remodelling equilibrium is reached. This period lasts for several years (roughly for 6-8 years) in the life of an adult human in his/her productive age, while in the life of a child this period is shorter. Figuratively speaking, the stages of the bone tissue remodelling (during one limit cycle) can be compared to the tissue "childhood and maruraiion" (i.e., n stage of remodelling - apposition of the tissue), and "aging-demise" (I stage of remodelling - resorption). One limit cycle of the bone tissue life (out of the series of the subsequent periodic limit cycles) that is characterized by the bone tissue development, functioning and destruction (in the unit volume element) can be synoptically, and in the real time, described by four stages. The limit cycle is a close trajectory of solution of kinetic equations of bone remodelling. The bone tissue (in its unit volume element) passes through the repeating harmonic limit cycles (i.e., the stable periodic processes) of its development and destruction.

15

A mathematical model of bone remodelling under overload and its application to evaluation of bone resorption around dental implants

Tanaka E., Yamamoto S., Nishida T., Aoki Yiichi

Acta of Bioengineering and Biomechanics

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1999

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Vol. 1, nr 1

117-121

EN

This paper deals with the formulation of a mathematical mosel allowing us to describe mechanical bone remodelling process and rapid bone resorption under overload. For this purpose, physiological signal transmission processes of remodelling from mechanical stimuli to the change of bone density are described by n +1 sequential evolution equations with n+1 macroscopic internal state variables. In the normal physiological situation, the value of internal variable K-th step approaches the value of the variable in the (k-1)-th step, but under overload conditions the target value in the k-th step reduces to a value much smaller that in the normal situation, which represents the loss of physiological balance. The value of the internal variable in the last step specifies the balance level of bone density. The simulation results showed that this model could describe a timedependent process of bone remodelling inclusing bone resorption. Finally, the proposed model was applied to problems of bone resorption around artificial implants. The simulation results predicted the bone resorption qualitatively.