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Irandoust S, Whitton RC, Muir P, Henak CR. Subchondral bone fatigue injury in the parasagittal condylar grooves of the third metacarpal bone in thoroughbred racehorses elevates site-specific strain concentration. J Mech Behav Biomed Mater 2024; 155:106561. [PMID: 38678748 DOI: 10.1016/j.jmbbm.2024.106561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 04/17/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Condylar stress fracture of the distal end of the third metacarpal/metatarsal (MC3/MT3) bones is a major cause of Thoroughbred racehorse injury and euthanasia worldwide. Functional adaptation to exercise and fatigue damage lead to structural changes in the subchondral bone that include increased modeling (resulting in sclerotic bone tissue) and targeted remodeling repair (resulting in focal resorption spaces in the parasagittal groove). Whether these focal structural changes, as detectable by standing computed tomography (sCT), lead to elevated strain at the common site of condylar stress fracture has not been demonstrated. Therefore, the goal of the present study was to compare full-field three-dimensional (3D) strain on the distopalmar aspect of MC3 bone specimens with and without focal subchondral bone injury (SBI). Thirteen forelimb specimens were collected from racing Thoroughbreds for mechanical testing ex vivo and underwent sCT. Subsequently, full-field displacement and strain at the joint surface were determined using stereo digital image correlation. Strain concentration was observed in the parasagittal groove (PSG) of the loaded condyles, and those with SBI in the PSG showed higher strain rates in this region than control bones. PSG strain rate in condyles with PSG SBI was more sensitive to CT density distribution in comparison with condyles with no sCT-detectable injury. Findings from this study help to interpret structural changes in the subchondral bone due to fatigue damage and to assess risk of incipient stress fracture in a patient-specific manner.
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Affiliation(s)
- Soroush Irandoust
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - R Christopher Whitton
- Equine Centre, Melbourne Veterinary School, University of Melbourne, Werribee, Vic, 3030, Australia
| | - Peter Muir
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Corinne R Henak
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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Wang J, Ishimoto T, Matsuzaka T, Matsugaki A, Ozasa R, Matsumoto T, Hayashi M, Kim HS, Nakano T. Adaptive enhancement of apatite crystal orientation and Young's modulus under elevated load in rat ulnar cortical bone. Bone 2024; 181:117024. [PMID: 38266952 DOI: 10.1016/j.bone.2024.117024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/02/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024]
Abstract
Functional adaptation refers to the active modification of bone structure according to the mechanical loads applied daily to maintain its mechanical integrity and adapt to the environment. Functional adaptation relates to bone mass, bone mineral density (BMD), and bone morphology (e.g., trabecular bone architecture). In this study, we discovered for the first time that another form of bone functional adaptation of a cortical bone involves a change in bone quality determined by the preferential orientation of apatite nano-crystallite, a key component of the bone. An in vivo rat ulnar axial loading model was adopted, to which a 3-15 N compressive load was applied, resulting in approximately 440-3200 μɛ of compression in the bone surface. In the loaded ulnae, the degree of preferential apatite c-axis orientation along the ulnar long axis increased in a dose-dependent manner up to 13 N, whereas the increase in BMD was not dose-dependent. The Young's modulus along the same direction was enhanced as a function of the degree of apatite orientation. This finding indicates that bone has a mechanism that modifies the directionality (anisotropy) of its microstructure, strengthening itself specifically in the loaded direction. BMD, a scalar quantity, does not allow for load-direction-specific strengthening. Functional adaptation through changes in apatite orientation is an excellent strategy for bones to efficiently change their strength in response to external loading, which is mostly anisotropic.
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Affiliation(s)
- Jun Wang
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Division of Material Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China.
| | - Takuya Ishimoto
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Aluminium Research Center, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan.
| | - Tadaaki Matsuzaka
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Aira Matsugaki
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Ryosuke Ozasa
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Takuya Matsumoto
- Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1, Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
| | - Mikako Hayashi
- Department of Restorative Dentistry and Endodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hyoung Seop Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea.
| | - Takayoshi Nakano
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Wu L, Ren C, Jiang H, Zhang W, Chen N, Zhao X, Wei G, Shu D. Land abandonment transforms soil microbiome stability and functional profiles in apple orchards of the Chinese Losses Plateau. Sci Total Environ 2024; 906:167556. [PMID: 37804979 DOI: 10.1016/j.scitotenv.2023.167556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/27/2023] [Accepted: 09/30/2023] [Indexed: 10/09/2023]
Abstract
Land abandonment is considered an effective strategy for ecological restoration on a global scale. However, few studies have focused on how environmental heterogeneity associated with the age of land abandonment affects the assembly and potential functions of the soil microbial community. In the present study, we investigated the community assembly of soil bacteria and fungi as well as the stability of soil networks and their potential functions in the chronosequence of abandoned apple orchards. We elucidated that the Shannon diversity of bacteria and the richness of fungi increased as land abandonment progressed. In addition, land abandonment destabilized the microbial network stability but increased network complexity. Soil available nitrogen, total carbon, and moisture are the potentially important factors in shaping the soil microbial assembly. Importantly, we showed that the microbial community diversity and functional diversity presented a synchronization effect in response to the different stages of land abandonment. Furthermore, specific bacterial taxa related to carbon fixation, dissimilatory nitrate reduction, and organic phosphorus mineralization were significantly enriched during the early abandonment stage. Collectively, these results indicate that land abandonment significantly transformed soil microbiome assembly and functional adaptation during the restoration process. These findings provide valuable insights into the influence of ecological restoration on soil microbiome and ecosystem functions in arable areas.
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Affiliation(s)
- Likun Wu
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, China
| | - Chengyao Ren
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, China
| | - Hai Jiang
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wenyu Zhang
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, China
| | - Ni Chen
- The Department of Agriculture and Rural Affairs of Shaanxi Province, Xi'an, Shaanxi 710000, China
| | - Xining Zhao
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100 Yangling, Shaanxi Province, China; Institute of Soil and Water Conservation, Northwest A&F University, 712100 Yangling, Shaanxi Province, China
| | - Gehong Wei
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, China.
| | - Duntao Shu
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, China.
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Naz N, Asghar A, Basharat S, Fatima S, Hameed M, Ahmad MSA, Ahmad F, Shah SMR, Ashraf M. Phytoremediation through microstructural and functional alterations in alkali weed ( Cressa cretica L.) in the hyperarid saline desert. Int J Phytoremediation 2023; 26:913-927. [PMID: 37985450 DOI: 10.1080/15226514.2023.2282044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Salt excretory halophytes are the major sources of phytoremediation of salt-affected soils. Cressa cretica is a widely distributed halophyte in hypersaline lands in the Cholistan Desert. Therefore, identification of key physio-anatomical traits related to phytoremediation in differently adapted C. cretica populations was focused on. Four naturally adapted ecotypes of non-succulent halophyte Cressa cretica L. form hyper-arid and saline desert Cholistan. The selected ecotypes were: Derawar Fort (DWF, ECe 20.8 dS m-1) from least saline site, Traway Wala Toba (TWT, ECe 33.2 dS m-1) and Bailah Wala Dahar (BWD, ECe 45.4 dS m-1) ecotypes were from moderately saline sites, and Pati Sir (PAS, ECe 52.4 dS m-1) was collected from the highly saline site. The natural population of this species was collected and carefully brought to the laboratory for different structural and functional traits. As a result of high salinity, Na+, Cl-, K+, and Ca2+ content significantly increased at root and shoot level. At root level, some distinctive modifications such as increased sclerification in vascular bundles, enlarged vascular bundles, metaxylem vessels, phloem region, and storage parenchyma (cortex) are pivotal for water storage under extreme arid and osmotic condition. At the stem level, enhanced sclerification in outer cortex and vascular bundles, stem cellular area, cortical proportion, metaxylem and phloem area, and at the leaf level, very prominent structural adaptations were thicker and smaller leaves with increased density of salt glands and trichomes at surface, few and large stomata, reduced cortical and mesophyll parenchyma, and narrow xylem vessels and phloem area represent their non-succulent nature. The ecotype collected from hypersaline environments was better adapted regarding growth traits, ion uptake and excretion, succulence, and phytoremediation traits. More importantly, structural and functional traits such as root length and biomass, accumulation of toxic ions along with K+ in root and shoot, accumulation of Ca2+ in shoot and Mg2+ in root, excretion of toxic ions were the highest in this ecotype. In conclusion, all these alterations strongly favor water conservation, which certainly contributes to ecotypes survival under salt-induced physiological drought.
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Affiliation(s)
- Nargis Naz
- Department of Botany, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Ansa Asghar
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Sana Basharat
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Sana Fatima
- Department of Botany, The Government Sadiq College University, Bahawalpur, Pakistan
| | - Mansoor Hameed
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | | | - Farooq Ahmad
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Syed Mohsan Raza Shah
- Department of Botany, Division of Science and Technology, University of Education, Lahore, Pakistan
| | - Muhammad Ashraf
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
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Skelin Klemen M, Kopecky J, Dolenšek J, Stožer A. Human Beta Cell Functional Adaptation and Dysfunction in Insulin Resistance and Its Reversibility. Nephron Clin Pract 2023; 148:78-84. [PMID: 37883937 PMCID: PMC10860743 DOI: 10.1159/000534667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 10/07/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Beta cells play a key role in the pathophysiology of diabetes since their functional adaptation is able to maintain euglycemia in the face of insulin resistance, and beta cell decompensation or dysfunction is a necessary condition for full-blown type 2 diabetes (T2D). The mechanisms behind compensation and decompensation are incompletely understood, especially for human beta cells, and even less is known about influences of chronic kidney disease (CKD) or immunosupressive therapy after transplantation on these processes and the development of posttransplant diabetes. SUMMARY During compensation, beta cell sensitivity to glucose becomes left-shifted, i.e., their sensitivity to stimulation increases, and this is accompanied by enhanced signals along the stimulus-secretion coupling cascade from membrane depolarization to intracellular calcium and the most distal insulin secretion dynamics. There is currently no clear evidence regarding changes in intercellular coupling during this stage of disease progression. During decompensation, intracellular stimulus-secretion coupling remains enhanced to some extent at low or basal glucose concentrations but seems to become unable to generate effective signals to stimulate insulin secretion at high or otherwise stimulatory glucose concentrations. Additionally, intercellular coupling becomes disrupted, lowering the number of cells that contribute to secretion. During progression of CKD, beta cells also seem to drift from a compensatory left-shift to failure, and immunosupressants can further impair beta cell function following kidney transplantation. KEY MESSAGES Beta cell stimulus-secretion coupling is enhanced in compensated insulin resistance. With worsening insulin resistance, both intra- and intercellular coupling become disrupted. CKD can progressively disrupt beta cell function, but further studies are needed, especially regarding changes in intercellular coupling.
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Affiliation(s)
- Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia,
| | - Jan Kopecky
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
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6
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Holt AG, Davies AM. The prevalence of dementia in humans could be the result of a functional adaptation. Comput Biol Chem 2023; 106:107939. [PMID: 37598466 DOI: 10.1016/j.compbiolchem.2023.107939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/31/2023] [Accepted: 08/07/2023] [Indexed: 08/22/2023]
Abstract
In this paper we propose that high copy number of the mitochondrial genome in neurons is a functional adaptation. We simulated the proliferation of deletion mutants of the human mitochondrial genome in a virtual mitochondrion and recorded the cell loss rates due to deletions overwhelming the wild-type. Our results showed that cell loss increased with mtDNA copy number. Given that neuron loss equates to cognitive dysfunction, it would seem counterintuitive that there would be a selective pressure for high copy number over low. However, for a low copy number, the onset of cognitive decline, while mild, started early in life. Whereas, for high copy number, it did not start until middle age but progressed rapidly. There could have been an advantage to high copy number in the brain if it delayed the onset of cognitive decline until after reproductive age. The prevalence of dementia in our aged population is a consequence of this functional adaptation.
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Delaunois Y, Smeets S, Malherbe C, Eppe G, Lecchini D, Ruffoni D, Compère P. Structure and mineralization of the spearing mantis shrimp (Stomatopoda; Lysiosquillina maculata) body and spike cuticles. J Struct Biol 2021; 213:107810. [PMID: 34774752 DOI: 10.1016/j.jsb.2021.107810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/19/2022]
Abstract
Stomatopoda is a crustacean order including sophisticated predators called spearing and smashing mantis shrimps that are separated from the well-studied Eumalacotraca since the Devonian. The spearing mantis shrimp has developed a spiky dactyl capable of impaling fishes or crustaceans in a fraction of second. In this high velocity hunting technique, the spikes undergo an intense mechanical constraint to which their exoskeleton (or cuticle) has to be adapted. To better understand the spike cuticle internal architecture and composition, electron microscopy, X-ray microanalysis and Raman spectroscopy were used on the spikes of 7 individuals (collected in French Polynesia and Indonesia), but also on parts of the body cuticle that have less mechanical stress to bear. In the body cuticle, several specificities linked to the group were found, allowing to determine the basic structure from which the spike cuticle has evolved. Results also highlighted that the body cuticle of mantis shrimps could be a model close to the ancestral arthropod cuticle by the aspect of its biological layers (epi- and procuticle including exo- and endocuticle) as well as by the Ca-carbonate/phosphate mineral content of these layers. In contrast, the spike cuticle exhibits a deeply modified organization in four functional regions overprinted on the biological layers. Each of them has specific fibre arrangement or mineral content (fluorapatite, ACP or phosphate-rich Ca-carbonate) and is thought to assume specific mechanical roles, conferring appropriate properties on the entire spike. These results agree with an evolution of smashing mantis shrimps from primitive stabbing/spearing shrimps, and thus also allowed a better understanding of the structural modifications described in previous studies on the dactyl club of smashing mantis shrimps.
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Affiliation(s)
- Yann Delaunois
- Laboratory of Functional and Evolutionary Morphology, FOCUS Research Unit, Department of Biology, Ecology and Evolution, University of Liège, Liège, Belgium.
| | - Sarah Smeets
- Laboratory of Functional and Evolutionary Morphology, FOCUS Research Unit, Department of Biology, Ecology and Evolution, University of Liège, Liège, Belgium; Center for Applied Research and Education in Microscopy (CAREM), University of Liège, Liège, Belgium
| | - Cédric Malherbe
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Liège, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Liège, Belgium
| | - David Lecchini
- Laboratoire d'Excellence «CORAIL», BP 1013, 98729 Papetoai, Moorea, French Polynesia; PSL Research University: EPHE-UPVD-CNRS, USR3278 CRIOBE, BP 1013, 98729 Papetoai, Moorea, French Polynesia
| | - Davide Ruffoni
- Mechanics of Biological and Bioinspired Materials Laboratory, Department of Aerospace and Mechanical Engineering, University of Liège, Liège, Belgium
| | - Philippe Compère
- Laboratory of Functional and Evolutionary Morphology, FOCUS Research Unit, Department of Biology, Ecology and Evolution, University of Liège, Liège, Belgium; Center for Applied Research and Education in Microscopy (CAREM), University of Liège, Liège, Belgium
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Li C, Gorb SN, Rajabi H. Biomechanical strategies to reach a compromise between stiffness and flexibility in hind femora of desert locusts. Acta Biomater 2021; 134:490-498. [PMID: 34293506 DOI: 10.1016/j.actbio.2021.07.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/11/2021] [Accepted: 07/13/2021] [Indexed: 11/28/2022]
Abstract
Insect cuticle can reach a wide range of material properties, which is thought to be the result of adaptations to applied mechanical stresses. Biomechanical mechanisms behind these property variations remain largely unknown. To fill this gap, here we performed a comprehensive study by simultaneous investigation of the microstructure, sclerotization and the elasticity modulus of the specialized cuticle of the femora of desert locusts. We hypothesized that, considering their different roles in jumping, the femora of fore-, mid- and hind legs should be equipped with cuticles that have different mechanical properties. Surprisingly, our results showed that the hind femur, which typically bears higher stresses, has a lower elasticity modulus than the fore and mid femora in the longitudinal direction. This is likely due to the lower sclerotization and different microstructure of the hind femur cuticle. This allows for some deformability in the femur wall and is likely to reduce the risk of mechanical failure. In contrast to both other femora, the hind femur is also equipped with a set of sclerotized ridges that are likely to provide it with the required stiffness to withstand the mechanical loads during walking and jumping. This paper is one of only a few comprehensive studies on insect cuticle, which advances the current understanding of the relationship between the structure, material property and function in this complex biological composite. STATEMENT OF SIGNIFICANCE: Insect cuticle is a biological composite with strong anisotropy and wide ranges of material properties. Using an example of the femoral cuticle of desert locusts, we measured the elasticity modulus, microstructure and sclerotization level of the cuticle. Our results show that, although the hind femur withstands most of the stress during locomotion, it has a lower elasticity modulus than the fore and mid femora. This is likely to be a functional adaption to jumping, in order to allow small deformations of the femur wall and reduce the risk of material failure. Our results deepen the current understanding of the structure-material-function relationship in the complex insect cuticle.
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Affiliation(s)
- Chuchu Li
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany.
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
| | - Hamed Rajabi
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany; Division of Mechanical Engineering and Design, School of Engineering, London South Bank University, London, UK
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Jang A, Wang B, Ustriyana P, Gansky SA, Maslenikov I, Useinov A, Prevost R, Ho SP. Functional adaptation of interradicular alveolar bone to reduced chewing loads on dentoalveolar joints in rats. Dent Mater 2021; 37:486-495. [PMID: 33589268 DOI: 10.1016/j.dental.2020.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 10/23/2020] [Accepted: 12/10/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The effects of reduced chewing loads on load bearing integrity of interradicular bone (IB) within dentoalveolar joints (DAJ) in rats were investigated. METHODS Four-week-old Sprague Dawley rats (N = 60) were divided into two groups; rats were either fed normal food, which is hard-pellet food (HF) (N = 30), or soft-powdered chow (SF) (N = 30). Biomechanical testing of intact DAJs and mapping of the resulting mechanical strains within IBs from 8- through 24-week-old rats fed HF or SF were performed. Tension- and compression-based mechanical strain profiles were mapped by correlating digital volumes of IBs at no load with the same IBs under load. Heterogeneity within IB was identified by mapping cement lines and TRAP-positive multinucleated cells using histology, and mechanical properties using nanoindentation technique. RESULTS Significantly decreased interradicular functional space, IB volume fraction, and elastic modulus of IB in the SF group compared with the HF group were observed, and these trends varied with an increase in age. The elastic modulus values illustrated significant heterogeneity within IB from HF or SF groups. Both compression- and tension-based strains were localized at the coronal portion of the IB and the variation in strain profiles complemented the observed material heterogeneity using histology and nanoindentation. SIGNIFICANCE Interradicular space and IB material-related mechanoadaptations in a DAJ are optimized to meet soft food related chewing demands. Results provided insights into age-specific regulation of chewing loads as a plausible "therapeutic dose" to reverse adaptations within the periodontal complex as an attempt to regain functional competence of a dynamic DAJ.
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Affiliation(s)
- Andrew Jang
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California San Francisco, CA 94143, United States
| | - Bo Wang
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California San Francisco, CA 94143, United States
| | - Putu Ustriyana
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California San Francisco, CA 94143, United States
| | - Stuart A Gansky
- Division of Oral Epidemiology & Dental Public Health, Department of Preventive and Restorative Dental Sciences, University of California San Francisco, CA 94143, United States
| | - Igor Maslenikov
- Technological Institute of Superhard and New Carbon Materials (TISNUM), ul. Tsentral'naya 7, Troitsk, Moscow, 142190, Russia
| | - Alex Useinov
- Technological Institute of Superhard and New Carbon Materials (TISNUM), ul. Tsentral'naya 7, Troitsk, Moscow, 142190, Russia
| | - Richard Prevost
- LaVision Inc. 211 W. Michigan Ave./Suite 100, Ypsilanti, MI 48197, United States
| | - Sunita P Ho
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California San Francisco, CA 94143, United States; Department of Urology, University of California San Francisco, CA 94143, United States.
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Berry E, Choudhary AK, Mishra G, Tandon R, Geeta R. Justicia adhatoda reveals two morphotypes with possible functional significance. J Plant Res 2020; 133:783-805. [PMID: 32979146 DOI: 10.1007/s10265-020-01224-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
Justicia adhatoda L. (Acanthaceae), an Old-World species of Justicia, is found in almost all geographical regions of India. Indian botanists have persistently used two accepted synonyms of J. adhatoda, namely, Adhatoda vasica and Adhatoda zeylanica, treating them as names of separate species, but without considering or making any reference to variation of forms in the species. Here, different aspects of variation-phenotypic, genotypic, and distributional-in Indian populations of J. adhatoda were studied to determine whether the two names might have been used to designate distinguishable forms of the species. We conducted field studies in different regions of India, laboratory studies of diverse phenotypic traits in experimental plots (anatomical, biochemical, reproductive, and morphometric), and a preliminary study of genetic variation using homologous cytochrome P450 gene fragments. We assessed herbarium samples from across India and the taxonomic literature for pointers indicating the presence of distinguishable forms. Population-level phenotypic and genetic variation pointed to the presence of two distinct morphotypes of the species, which separately tend to occur in dry and wet regions. Each form retains its original phenotype, either when the two forms are transplanted and cultivated together, or when found growing in regions (presumed introduced) outside its normal distributional range. Morphological studies and metabolic profiling (leaf and seed fatty acids, wax load and wax composition in leaf) suggest functional adaptation of the two forms, one to drier and the other to wetter regions. We could distinguish these forms in herbarium specimens dating back to 1821, but neither herbarium specimens nor the taxonomic literature reveal any reference to two forms. We propose that the forms be recognized as two distinct morphotypes of Justicia adhatoda.
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Affiliation(s)
- Eapsa Berry
- Department of Botany, University of Delhi, Delhi, 110007, India
| | | | - Girish Mishra
- Department of Botany, University of Delhi, Delhi, 110007, India
| | - Rajesh Tandon
- Department of Botany, University of Delhi, Delhi, 110007, India
| | - R Geeta
- Department of Botany, University of Delhi, Delhi, 110007, India.
- , A1/7/1 22nd Cross Street, Besant Nagar, Chennai, 600090, India.
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Caputo G, Ippolito G, Mazzotta M, Sentenza L, Muzio MR, Salzano S, Conson M. Effectiveness of a Multisystem Aquatic Therapy for Children with Autism Spectrum Disorders. J Autism Dev Disord 2019; 48:1945-1956. [PMID: 29313176 DOI: 10.1007/s10803-017-3456-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aquatic therapy improves motor skills of persons with Autism Spectrum Disorders (ASD), but its usefulness for treating functional difficulties needs to be verified yet. We tested effectiveness of a multisystem aquatic therapy on behavioural, emotional, social and swimming skills of children with ASD. Multisystem aquatic therapy was divided in three phases (emotional adaptation, swimming adaptation and social integration) implemented in a 10-months-programme. At post-treatment, the aquatic therapy group showed significant improvements relative to controls on functional adaptation (Vineland Adaptive Behavior Scales), emotional response, adaptation to change and on activity level (Childhood Autism Rating Scale). Swimming skills learning was also demonstrated. Multisystem aquatic therapy is useful for ameliorating functional impairments of children with ASD, going well beyond a swimming training.
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Affiliation(s)
- Giovanni Caputo
- Center for Studies and Research "Caputo & Ippolito - Multisystemic Aquatic Therapy", Casoria, Via Vincenzo Cuoco, 26, 80026, Naples, Italy
| | - Giovanni Ippolito
- Center for Studies and Research "Caputo & Ippolito - Multisystemic Aquatic Therapy", Casoria, Via Vincenzo Cuoco, 26, 80026, Naples, Italy
| | - Marina Mazzotta
- Center for Studies and Research "Caputo & Ippolito - Multisystemic Aquatic Therapy", Casoria, Via Vincenzo Cuoco, 26, 80026, Naples, Italy
| | - Luigi Sentenza
- Center for Studies and Research "Caputo & Ippolito - Multisystemic Aquatic Therapy", Casoria, Via Vincenzo Cuoco, 26, 80026, Naples, Italy
| | - Mara Rosaria Muzio
- UOMI ASL Naples Third-South, Service of Developmental Neuropsychiatry, District 57, Torre del Greco, Via Marconi, 80059, Naples, Italy
| | - Sara Salzano
- Cognitive-Behavioral School of Psychotherapy "Serapide SPEE", Naples, Italy
| | - Massimiliano Conson
- Neuropsychology Laboratory, Department of Psychology, University of Campania "Luigi Vanvitelli", Viale Ellittico 31, 81100, Caserta, Italy.
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Brown WE, DuRaine GD, Hu JC, Athanasiou KA. Structure-function relationships of fetal ovine articular cartilage. Acta Biomater 2019; 87:235-244. [PMID: 30716555 DOI: 10.1016/j.actbio.2019.01.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/10/2019] [Accepted: 01/31/2019] [Indexed: 12/21/2022]
Abstract
It is crucial that the properties of engineered neocartilage match healthy native cartilage to promote the functional restoration of damaged cartilage. To accurately assess the quality of neocartilage and the degree of biomimicry achieved, its properties must be evaluated against native cartilage and tissue from which the cells for neocartilage formation were sourced. Fetal ovine cartilage is a promising and translationally relevant cell source with which to engineer neocartilage, yet, it is largely non-characterized. The influence of biomechanics during cartilage development, as well as their potential impact on structure-function relationships in utero motivates additional study of fetal cartilage. Toward providing tissue engineering design criteria and elucidating structure-function relationships, 11 locations across four regions of the fetal ovine stifle were characterized. Locational and regional differences were found to exist. Although differences in GAG content were observed, compressive stiffness did not vary or correlate with any biochemical component. Patellar cartilage tensile stiffness and strength were significantly greater than those of the medial condyle. Tensile modulus and UTS significantly correlated with pyridinoline content. More advanced zonal organization, more intense collagen II staining, and greater collagen and pyridinoline contents in the trochlear groove and patella suggest these regions exhibit a more advanced maturational state than others. Regional differences in functional properties and their correlations suggest that structure-function relationships emerge in utero. These data address the dearth of information of the fetal ovine stifle, may serve as a repository of information for cartilage engineering strategies, and may help elucidate functional adaptation in fetal articular cartilage. STATEMENT OF SIGNIFICANCE: Engineered neocartilage must be evaluated against healthy native cartilage and cell source tissue to determine its quality and degree of biomimicry. While fetal ovine cartilage has emerged as a promising and translationally relevant cell source with which to engineer neocartilage, it is largely non-characterized. Therefore, 11 locations across four regions (medial condyle, lateral condyle, trochlear groove, and patella) of the fetal ovine stifle were characterized. Importantly, locational and regional differences in functional properties were observed, and significant correlations of tensile properties to collagen and crosslink contents were detected, suggesting that functional adaptation begins in utero. This study provides a repository of quantitative information, clarifies the developmental order of cartilage functional properties, and informs future cartilage engineering efforts.
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Salamanova E, Costeira-Paulo J, Han KH, Kim DH, Nilsson L, Wright APH. A subset of functional adaptation mutations alter propensity for α-helical conformation in the intrinsically disordered glucocorticoid receptor tau1core activation domain. Biochim Biophys Acta Gen Subj 2018; 1862:1452-1461. [PMID: 29550429 DOI: 10.1016/j.bbagen.2018.03.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/07/2018] [Accepted: 03/10/2018] [Indexed: 01/22/2023]
Abstract
BACKGROUND Adaptive mutations that alter protein functionality are enriched within intrinsically disordered protein regions (IDRs), thus conformational flexibility correlates with evolvability. Pre-structured motifs (PreSMos) with transient propensity for secondary structure conformation are believed to be important for IDR function. The glucocorticoid receptor tau1core transcriptional activation domain (GR tau1core) domain contains three α-helical PreSMos in physiological buffer conditions. METHODS Sixty change-of-function mutants affecting the intrinsically disordered 58-residue GR tau1core were studied using disorder prediction and molecular dynamics simulations. RESULTS Change-of-function mutations were partitioned into seven clusters based on their effect on IDR predictions and gene activation activity. Some mutations selected from clusters characterized by mutations altering the IDR prediction score, altered the apparent stability of the α-helical form of one of the PreSMos in molecular dynamics simulations, suggesting PreSMo stabilization or destabilization as strategies for functional adaptation. Indeed all tested gain-of-function mutations affecting this PreSMo were associated with increased stability of the α-helical PreSMo conformation, suggesting that PreSMo stabilization may be the main mechanism by which adaptive mutations can increase the activity of this IDR type. Some mutations did not appear to affect PreSMo stability. CONCLUSIONS Changes in PreSMo stability account for the effects of a subset of change-of-function mutants affecting the GR tau1core IDR. GENERAL SIGNIFICANCE Long IDRs occur in about 50% of human proteins. They are poorly characterized despite much recent attention. Our results suggest the importance of a subtle balance between PreSMo stability and IDR activity, which may provide a novel target for future pharmaceutical intervention.
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Affiliation(s)
- Evdokiya Salamanova
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, TTI, SE-141 83 Huddinge, Sweden
| | - Joana Costeira-Paulo
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, TTI, SE-141 83 Huddinge, Sweden.
| | - Kyou-Hoon Han
- Genome Editing Research Center, Future Biotechnology Research Division, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea; Department of Nano and Bioinformatics, University of Science and Technology, 113 Gwahak-ro, Yuseong-gu, Daejeon 305-333, Republic of Korea.
| | - Do-Hyoung Kim
- Genome Editing Research Center, Future Biotechnology Research Division, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea.
| | - Lennart Nilsson
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, TTI, SE-141 83 Huddinge, Sweden.
| | - Anthony P H Wright
- Clinical Research Center, Department of Laboratory Medicine, Karolinska Institutet, NOVUM Level 5, Hälsovägen 7, SE-141 57 Huddinge, Sweden.
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Mielke M, Wölfer J, Arnold P, van Heteren AH, Amson E, Nyakatura JA. Trabecular architecture in the sciuromorph femoral head: allometry and functional adaptation. Zoological Lett 2018; 4:10. [PMID: 29785282 PMCID: PMC5954450 DOI: 10.1186/s40851-018-0093-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 04/17/2018] [Indexed: 05/21/2023]
Abstract
BACKGROUND Sciuromorpha (squirrels and close relatives) are diverse in terms of body size and locomotor behavior. Individual species are specialized to perform climbing, gliding or digging behavior, the latter being the result of multiple independent evolutionary acquisitions. Each lifestyle involves characteristic loading patterns acting on the bones of sciuromorphs. Trabecular bone, as part of the bone inner structure, adapts to such loading patterns. This network of thin bony struts is subject to bone modeling, and therefore reflects habitual loading throughout lifetime. The present study investigates the effect of body size and lifestyle on trabecular structure in Sciuromorpha. METHODS Based upon high-resolution computed tomography scans, the femoral head 3D inner microstructure of 69 sciuromorph species was analyzed. Species were assigned to one of the following lifestyle categories: arboreal, aerial, fossorial and semifossorial. A cubic volume of interest was selected in the center of each femoral head and analyzed by extraction of various parameters that characterize trabecular architecture (degree of anisotropy, bone volume fraction, connectivity density, trabecular thickness, trabecular separation, bone surface density and main trabecular orientation). Our analysis included evaluation of the allometric signals and lifestyle-related adaptation in the trabecular parameters. RESULTS We show that bone surface density, bone volume fraction, and connectivity density are subject to positive allometry, and degree of anisotropy, trabecular thickness, and trabecular separation to negative allometry. The parameters connectivity density, bone surface density, trabecular thickness, and trabecular separation show functional signals which are related to locomotor behavior. Aerial species are distinguished from fossorial ones by a higher trabecular thickness, lower connectivity density and lower bone surface density. Arboreal species are distinguished from semifossorial ones by a higher trabecular separation. CONCLUSION This study on sciuromorph trabeculae supplements the few non-primate studies on lifestyle-related functional adaptation of trabecular bone. We show that the architecture of the femoral head trabeculae in Sciuromorpha correlates with body mass and locomotor habits. Our findings provide a new basis for experimental research focused on functional significance of bone inner microstructure.
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Affiliation(s)
- Maja Mielke
- AG Morphologie und Formengeschichte, Institut für Biologie und Bild Wissen Gestaltung. Ein interdisziplinäres Labor, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099 Germany
| | - Jan Wölfer
- AG Morphologie und Formengeschichte, Institut für Biologie und Bild Wissen Gestaltung. Ein interdisziplinäres Labor, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099 Germany
| | - Patrick Arnold
- Institut für Zoologie und Evolutionsforschung mit Phyletischem Museum, Ernst-Haeckel-Haus und Biologiedidaktik, Friedrich-Schiller-Universität Jena, Erbert-Straße 1, Jena, 07743 Germany
- Department of Human EvolutionMax Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103 Germany
| | - Anneke H. van Heteren
- Sektion Mammalogie, Zoologische Staatssammlung München – Staatliche Naturkundliche Sammlungen Bayerns, Münchhausenstr. 21, München, 81247 Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, München, 80333 Germany
- Department Biologie II, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, Planegg-Martinsried, 82152 Germany
| | - Eli Amson
- AG Morphologie und Formengeschichte, Institut für Biologie und Bild Wissen Gestaltung. Ein interdisziplinäres Labor, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099 Germany
| | - John A. Nyakatura
- AG Morphologie und Formengeschichte, Institut für Biologie und Bild Wissen Gestaltung. Ein interdisziplinäres Labor, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099 Germany
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Amson E, Arnold P, van Heteren AH, Canoville A, Nyakatura JA. Trabecular architecture in the forelimb epiphyses of extant xenarthrans (Mammalia). Front Zool 2017; 14:52. [PMID: 29213295 PMCID: PMC5707916 DOI: 10.1186/s12983-017-0241-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/08/2017] [Indexed: 12/12/2022] Open
Abstract
Background Bone structure has a crucial role in the functional adaptations that allow vertebrates to conduct their diverse lifestyles. Much has been documented regarding the diaphyseal structure of long bones of tetrapods. However, the architecture of trabecular bone, which is for instance found within the epiphyses of long bones, and which has been shown experimentally to be extremely plastic, has received little attention in the context of lifestyle adaptations (virtually only in primates). We therefore investigated the forelimb epiphyses of extant xenarthrans, the placental mammals including the sloths, anteaters, and armadillos. They are characterised by several lifestyles and degrees of fossoriality involving distinct uses of their forelimb. We used micro computed tomography data to acquire 3D trabecular parameters at regions of interest (ROIs) for all extant genera of xenarthrans (with replicates). Traditional, spherical, and phylogenetically informed statistics (including the consideration of size effects) were used to characterise the functional signal of these parameters. Results Several trabecular parameters yielded functional distinctions. The main direction of the trabeculae distinguished lifestyle categories for one ROI (the radial trochlea). Among the other trabecular parameters, it is the degree of anisotropy (i.e., a preferential alignment of the trabeculae) that yielded the clearest functional signal. For all ROIs, the armadillos, which represent the fully terrestrial and fossorial category, were found as characterised by a greater degree of anisotropy (i.e., more aligned trabeculae). Furthermore, the trabeculae of the humeral head of the most fossorial armadillos were also found to be more anisotropic than in the less fossorial species. Conclusions Most parameters were marked by an important intraspecific variability and by a size effect, which could, at least partly, be masking the functional signal. But for some parameters, the degree of anisotropy in particular, a clear functional distinction was recovered. Along with data on primates, our findings suggest that a trabecular architecture characterised by a greater degree of anisotropy is to be expected in species in which the relevant epiphyses withstand a restricted range of load directions. Trabecular architecture therefore is a promising research avenue for the reconstruction of lifestyles in extinct or cryptic species. Electronic supplementary material The online version of this article (10.1186/s12983-017-0241-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eli Amson
- AG Morphologie und Formengeschichte, Institut für Biologie, Humboldt Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany.,Bild Wissen Gestaltung. Ein Interdisziplinäres Labor, Humboldt Universität zu Berlin, Sophienstraße 22a, 10178 Berlin, Germany
| | - Patrick Arnold
- Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller-Universität Jena, Erbertstraße 1, 07743 Jena, Germany
| | - Anneke H van Heteren
- Sektion Mammalogie, Zoologische Staatssammlung München, Staatliche Naturwissenschaftliche Sammlungen Bayerns, Münchhausenstraße 21, 81247 Munich, Germany
| | - Aurore Canoville
- Steinmann Institute for Geology, Mineralogy, and Paleontology, University of Bonn, Nußallee 8, D-53113 Bonn, Germany
| | - John A Nyakatura
- AG Morphologie und Formengeschichte, Institut für Biologie, Humboldt Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany.,Bild Wissen Gestaltung. Ein Interdisziplinäres Labor, Humboldt Universität zu Berlin, Sophienstraße 22a, 10178 Berlin, Germany
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Morgan TG, Bostrom MP, van der Meulen MC. Tissue-level remodeling simulations of cancellous bone capture effects of in vivo loading in a rabbit model. J Biomech 2015; 48:875-82. [PMID: 25579991 DOI: 10.1016/j.jbiomech.2014.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2014] [Indexed: 01/08/2023]
Abstract
The adaptation of cancellous bone to mechanical stimuli occurs throughout normal skeletal growth and aging, as well as in response to surgery, disease and device implantation. Previously we developed an in vivo cancellous loading model in the distal lateral femur of the rabbit. In response to daily in vivo loading for four weeks, bone mass increased, trabeculae thickened and the apparent modulus of the underlying cancellous bone increased. Here, we simulated our prior in vivo rabbit loading experiment using a cell-based tissue remodeling algorithm (Mullender et al., 1994) and compared the results to the in vivo experimental data published previously. Cancellous bone tissue was added or removed from the surface of trabeculae in regions of high and low mechanical stimulus, respectively. To examine the effect of material properties on mechanically regulated adaptation, we implemented both a homogeneous material model and a model where the relative density of tissue was lower for new and surface bone tissue compared to interior tissue. The simulations captured the changes in histomorphometric parameters and mechanical properties measured in the in vivo experiment illustrating the ability of computational simulations to predict the effect of mechanically regulated adaptation on cancellous bone histomorphometry and apparent modulus.
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Abstract
Implant fixation implies a strong and durable mechanical bond between the prosthetic component and host skeleton. Assuming the short-term impediments to implant fixation are successfully addressed and that longer-term issues such as late infection and mechanical failure of the components are avoided, the biological response of the host tissue to the presence of the implant is critical to long-term success. In particular, maintenance of adequate peri-prosthetic bone stock is a key factor. Two major causes of bone loss in the supporting bone are adverse bone remodeling in response to debris shed from the implant and stress-shielding. Here, I review some of the major lessons learned from studying stress-shielding-induced bone loss. It is well known that stress-shielding can be manipulated by altering implant design, but less well appreciated that the development of bone anabolic agents may make it possible to reduce the severity of stress-shielding and the associated bone loss by augmenting the host skeleton through the use of locally or systemically delivered agents. In most cases, mechanical, material and biological factors do not act in isolation, emphasizing that it is often not possible to optimize all boundary conditions.
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Affiliation(s)
- D R Sumner
- Departments of Anatomy and Cell Biology and Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612, United States.
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Schlecht SH, Bigelow EMR, Jepsen KJ. Mapping the natural variation in whole bone stiffness and strength across skeletal sites. Bone 2014; 67:15-22. [PMID: 24999223 PMCID: PMC4786740 DOI: 10.1016/j.bone.2014.06.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 06/20/2014] [Accepted: 06/25/2014] [Indexed: 10/25/2022]
Abstract
Traits of the skeletal system are coordinately adjusted to establish mechanical homeostasis in response to genetic and environmental factors. Prior work demonstrated that this 'complex adaptive' process is not perfect, revealing a two-fold difference in whole bone stiffness of the tibia across a population. Robustness (specifically, total cross-sectional area relative to length) varies widely across skeletal sites and between sexes. However, it is unknown whether the natural variation in whole bone stiffness and strength also varies across skeletal sites and between men and women. We tested the hypotheses that: 1) all major long bones of the appendicular skeleton demonstrate inherent, systemic constraints in the degree to which morphological and compositional traits can be adjusted for a given robustness; and 2) these traits covary in a predictable manner independent of body size and robustness. We assessed the functional relationships among robustness, cortical area (Ct.Ar), cortical tissue mineral density (Ct.TMD), and bone strength index (BSI) across the long bones of the upper and lower limbs of 115 adult men and women. All bones showed a significant (p<0.001) positive regression between BSI and robustness after adjusting for body size, with slender bones being 1.7-2.3 times less stiff and strong in men and 1.3-2.8 times less stiff and strong in women compared to robust bones. Our findings are the first to document the natural inter-individual variation in whole bone stiffness and strength that exist within populations and that is predictable based on skeletal robustness for all major long bones. Documenting and further understanding this natural variation in strength may be critical for differentially diagnosing and treating skeletal fragility.
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Affiliation(s)
- Stephen H Schlecht
- Department of Orthopaedic Surgery, University of Michigan, Biomedical Sciences Research Building, Ann Arbor, MI 48109, USA.
| | - Erin M R Bigelow
- Department of Orthopaedic Surgery, University of Michigan, Biomedical Sciences Research Building, Ann Arbor, MI 48109, USA
| | - Karl J Jepsen
- Department of Orthopaedic Surgery, University of Michigan, Biomedical Sciences Research Building, Ann Arbor, MI 48109, USA
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Smith LM, Bigelow EMR, Nolan BT, Faillace ME, Nadeau JH, Jepsen KJ. Genetic perturbations that impair functional trait interactions lead to reduced bone strength and increased fragility in mice. Bone 2014; 67:130-8. [PMID: 25003813 PMCID: PMC4413452 DOI: 10.1016/j.bone.2014.06.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/19/2014] [Accepted: 06/26/2014] [Indexed: 11/23/2022]
Abstract
Functional adaptation may complicate the choice of phenotype used in genetic studies that seek to identify genes contributing to fracture susceptibility. Often, genetic variants affecting one trait are compensated by coordinated changes in other traits. Bone fracture is a prototypic example because mechanical function of long bones (stiffness and strength) depends on how the system coordinately adjusts the amount (cortical area) and quality (tissue-mineral density, TMD) of bone tissue to mechanically offset the natural variation in bone robustness (total area/length). We propose that efforts aimed at identifying genes regulating fracture resistance will benefit from better understanding how functional adaptation contributes to the genotype-phenotype relationship. We analyzed the femurs of C57BL/6J-Chr(A/J)/NaJ Chromosome Substitution Strains (CSSs) to systemically interrogate the mouse genome for chromosomes harboring genes that regulate mechanical function. These CSSs (CSS-i, i=the substituted chromosome) showed changes in mechanical function on the order of -26.6 to +11.5% relative to the B6 reference strain after adjusting for body size. Seven substitutions showed altered robustness, cortical area, or TMD, but no effect on mechanical function (CSS-4, 5, 8, 9, 17, 18, 19); six substitutions showed altered robustness, cortical area, or TMD, and reduced mechanical function (CSS-1, 2, 6, 10, 12, 15); and one substitution also showed reduced mechanical function but exhibited no significant changes in the three physical traits analyzed in this study (CSS-3). A key feature that distinguished CSSs that maintained function from those with reduced function was whether the system adjusted cortical area and TMD to the levels needed to compensate for the natural variation in bone robustness. These results provide a novel biomechanical mechanism linking genotype with phenotype, indicating that genes control function not only by regulating individual traits, but also by regulating how the system coordinately adjusts multiple traits to establish function.
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Affiliation(s)
- Lauren M Smith
- Department of Orthopaedic Surgery, The University of Michigan, Ann Arbor, MI USA
| | - Erin M R Bigelow
- Department of Orthopaedic Surgery, The University of Michigan, Ann Arbor, MI USA
| | - Bonnie T Nolan
- Department of Orthopaedic Surgery, The University of Michigan, Ann Arbor, MI USA
| | | | | | - Karl J Jepsen
- Department of Orthopaedic Surgery, The University of Michigan, Ann Arbor, MI USA.
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Zhang RY, Li GG, Zhang CF, Tang YT, Zhao K. [Morphological differentiations of the gills of two Gymnocypris przewa-lskii subspecies in different habitats and their functional adaptations]. Dongwuxue Yanjiu 2014; 34:387-91. [PMID: 23913889 DOI: 10.11813/j.issn.0254-5853.2013.4.0387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gill morphologies of two subspecies of Gymnocypris przewalskii (Gymnocypris przewalskii przewalskii and Gymnocypris przewalskii ganzihonensis) in different habitats were analyzed under scanning electron microscope. Results indicated that G. p. przewalskii had numerous long and dense-lined gill rakers while G. p. ganzihonensis had few short and scatter-lined gill rakers. There were no significant differences in distance between gill filaments (DBF) and distance gill lamella (DBL) between the two subspecies, but gill filaments of G. p. przewalskii were longer than in G. p. ganzihonensis. The electron microscopic study indicated that the pavement epithelium cells of G. p. przewalskii were well defined as irregular ovals, but were hexagonal in G. p. ganzihonensis. Moreover, G. p. przewalskii had more chloride cells than G. p. ganzihonensis, and mucous cells were only found on the surface of gill filaments of G. p. przewalskii. The morphological differences between the two subspecies of G. przewalskii are adaptations to their corresponding diets and habitats.
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Affiliation(s)
- Ren-Yi Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China.
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