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Taillebot V, Krieger T, Maurel-Pantel A, Kim Y, Ollivier M, Pithioux M. Freezing does not influence the microarchitectural parameters of the microstructure of the freshly harvested femoral head bone. Cell Tissue Bank 2024; 25:747-754. [PMID: 39103569 DOI: 10.1007/s10561-024-10147-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Accepted: 07/17/2024] [Indexed: 08/07/2024]
Abstract
The femoral head is one of the most commonly used bones for allografts and biomechanical studies. However, there are few reports on the trabecular bone microarchitectural parameters of freshly harvested trabecular bones. To our knowledge, this is the first study to characterize the microstructure of femoral heads tested immediately after surgery and compare it with the microstructure obtained with conventional freezing. This study aims to investigate whether freezing at -80 °C for 6 weeks affects the trabecular microstructure of freshly harvested bone tissue. This study was divided into two groups: one with freshly harvested human femoral heads and the other with the same human femoral heads frozen at -80 °C for 6 weeks. Each femoral head was scanned using an X-ray microcomputed tomography scanner (µCT) to obtain the microarchitectural parameters, including the bone volume fraction (BV/TV), the mean trabecular thickness (Tb.th), the trabecular separation (Tb.sp), the degree of anisotropy (DA), and the connectivity density (Conn.D). There was no statistically significant difference between the fresh and the frozen groups for any of the parameters measured. This study shows that freezing at -80 °C for 6 weeks does not alter bone microstructure compared with freshly harvested femoral heads tested immediately after surgery.
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Affiliation(s)
- Virginie Taillebot
- Aix Marseille Univ, CNRS, ISM, 13009, Marseille, France.
- Department of Orthopaedics and Traumatology, Institute for Locomotion, Aix Marseille Univ, APHM, CNRS, ISM, Sainte-Marguerite Hospital, 13009, Marseille, France.
| | - Théo Krieger
- Aix Marseille Univ, CNRS, ISM, 13009, Marseille, France
- BIOBank, Tissue Bank, 77127, Lieusaint, France
| | | | - Youngji Kim
- Department of Orthopaedics and Traumatology, Institute for Locomotion, Aix Marseille Univ, APHM, CNRS, ISM, Sainte-Marguerite Hospital, 13009, Marseille, France
- Department of Orthopaedics, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Matthieu Ollivier
- Aix Marseille Univ, CNRS, ISM, 13009, Marseille, France
- Department of Orthopaedics and Traumatology, Institute for Locomotion, Aix Marseille Univ, APHM, CNRS, ISM, Sainte-Marguerite Hospital, 13009, Marseille, France
| | - Martine Pithioux
- Aix Marseille Univ, CNRS, ISM, 13009, Marseille, France
- Department of Orthopaedics and Traumatology, Institute for Locomotion, Aix Marseille Univ, APHM, CNRS, ISM, Sainte-Marguerite Hospital, 13009, Marseille, France
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2
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Hu X, Chen Z, Mo M, Zhou X, Chen L. Relationship between interincisal angles and TMJ morphology/position and trabecular structure: a retrospective study. BMC Oral Health 2024; 24:1016. [PMID: 39215287 PMCID: PMC11363554 DOI: 10.1186/s12903-024-04788-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 08/21/2024] [Indexed: 09/04/2024] Open
Abstract
BACKGROUND TMJ morphology/position and trabecular structure are influenced by various factors. The role of the interincisal angle, an indicator of the anterior occlusal relationship, on TMJ remains unclear. This study aims to investigate the morphology, trabecular bone structure, and position of the condyle, as well as the glenoid fossa's morphology in skeletal class II populations with different interincisal angles. MATERIALS AND METHODS A total of 150 adult patients with normodivergent facial types and skeletal class II malocclusions were selected and divided into three groups based on their interincisal angles: normal, small, and large angle groups. The indexes of TMJ were measured using cone-beam computed tomography (CBCT) data and analyzed using Dolphin Imaging, Mimics, and ImageJ. RESULTS The small angle group had the smallest anteroposterior diameter (APD), while the large angle group had a greater mediolateral diameter (MLD). The large angle group exhibited significantly the largest maximum axial area, bone surface area, and bone volume (P < 0.05). Small and large angle groups exhibited greater bone trabeculae (Tb. N) and thinner trabecular thickness (Tb. Th). Compared to the normal angle group, the small angle group exhibited a larger horizontal condylar angle and smaller bilateral condylar angles on the axial plane, while the large angle group showed the opposite trend. Small and large angle groups showed a reduced vertical condyle angle on the coronal plane, with the largest reduction observed in the large angle group (P < 0.05). Small and large angle groups had higher heights of the glenoid fossa (GFH). The large angle group exhibited the greatest GFH and width of the glenoid fossa (GFW) (P < 0.05). CONCLUSION The large angle group had elongated oval and large condyles, and deeper glenoid fossae, while a flattened-oval and smaller condyle, and wider and shallower glenoid fossae were observed in the small angle group. Small and large interincisal angle affects the structure of condylar trabeculae, resulting in thinner Tb. Th and greater Th. N. In the condylar position, small and large angle groups exhibit condylar rotation in the axial and coronal planes. Therefore, the interincisal angle affects the morphology, position, and trabecular structure of the TMJ. This implies that we must pay attention to the impact of the interincisal angle on TMJ, and it is crucial to restore the normal interincisal angle during orthodontic treatment.
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Affiliation(s)
- Xiaowen Hu
- Department of Orthodontics, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China
| | - Ziwei Chen
- Department of Orthodontics, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China
| | - Minhua Mo
- Department of Orthodontics, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China
| | - Xiaohe Zhou
- Department of Orthodontics, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China
| | - Liangjiao Chen
- Department of Orthodontics, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, 510182, Guangdong, People's Republic of China.
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3
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Wang Y, Li J, Men Y, Wei W. Age-related Differences in Volumetric Bone Mineral Density, Structure, and Bone Strength of Surgical Neck of Humerus in Postmenopausal Women. Orthop Surg 2024. [PMID: 39117579 DOI: 10.1111/os.14186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 07/15/2024] [Accepted: 07/21/2024] [Indexed: 08/10/2024] Open
Abstract
OBJECTIVE Postmenopausal changes in bone mass and structure compromise the mechanical properties of proximal humerus, predisposing it to low-energy fractures with complex morphology. The aim of the study is to investigate associations of bone quality and estimated bone strength of the surgical neck with age after menopause. METHODS A total of 122 healthy postmenopausal women were recruited from December 2016 to December 2022 and assigned to three groups: the 50-59 years group, the 60-69 years group, and the older than 70 years group. Bone properties of the surgical neck, including volumetric bone mineral density (vBMD), cortical thickness (CTh), the periosteal and medullary size, and estimated indices of bone strength were evaluated by quantitative computed tomography. RESULTS Compared to the 50-59 years group, postmenopausal women aged over 70 years were characterized by lower cortical thickness (13.9%) and vBMD (6.65%), as well as reduced strength indices including the minimum and maximum section modulus (Zmin 18.11%, Zmax 21.71%), polar section modulus (Zpol 20.21%), and the minimum and maximum second moments of area (Imax 21.01%, Imin 21.43%). Meanwhile, the difference in periosteal diameter and perimeter, total area in three groups did not reach statistical significance. Both cortical thickness and vBMD value were inversely associated with age, showing 10.56% and 23.92% decline. Imax showed the greatest age-related decrease between age of 54 and 86 years (39.08%), followed by Zmax (-35.77%), Imin (-35.73%), Zpol (-34.90%) and Imin (-23.92%).The strength indices had stronger correlations with cortical thickness than with bone size or density. CONCLUSION In postmenopausal women, aging is associated with a significant decline in cortical bone thickness and mechanical strength of the proximal humerus, especially over the age of 70 years.
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Affiliation(s)
- Yeming Wang
- Department of Orthopedics, Tianjin Hospital, Tianjin University, Tianjin, China
| | - Jian Li
- Department of Radiology, Tianjin Hospital, Tianjin University, Tianjin, China
| | - Yutao Men
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, China
| | - Wanfu Wei
- Department of Orthopedics, Tianjin Hospital, Tianjin University, Tianjin, China
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4
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Bleuze MM. Changes in limb bone diaphyseal structure in chimpanzees during development. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24942. [PMID: 38602254 DOI: 10.1002/ajpa.24942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 02/24/2024] [Accepted: 04/02/2024] [Indexed: 04/12/2024]
Abstract
OBJECTIVES This study tests if femoral and humeral cross-sectional geometry (CSG) and cross-sectional properties (CSPs) in an ontogenetic series of wild-caught chimpanzees (Pan troglodytes ssp.) reflect locomotor behavior during development. The goal is to clarify the relationship between limb bone structure and locomotor behavior during ontogeny in Pan. MATERIALS AND METHODS The latex cast method was used to reconstruct cross sections at the midshaft femur and mid-distal humerus. Second moments of area (SMAs) (Ix, Iy, Imax, Imin), which are proportional to bending rigidity about a specified axis, and the polar SMA (J), which is proportional to average bending rigidity, were calculated at section locations. Cross-sectional shape (CSS) was assessed from Ix/Iy and Imax/Imin ratios. Juvenile and adult subsamples were compared. RESULTS Juveniles and adults have significantly greater femoral J compared to humeral J. Mean interlimb proportions of J are not significantly different between the groups. There is an overall decreasing trend in diaphyseal circularity between the juvenile phase of development and adulthood, although significant differences are only found in the humerus. DISCUSSION Juvenile chimpanzee locomotion includes forelimb- and hindlimb-biased behaviors. Juveniles and adults preferentially load their hindlimbs relative to their forelimbs. This may indicate similar locomotor behavior, although other explanations including a diversity of hindlimb-biased locomotor behaviors in juveniles cannot be ruled out. Different ontogenetic trends in forelimb and hindlimb CSS are consistent with limb bone CSG reflecting functional adaptation, albeit the complex nature of bone functional adaptation requires cautious interpretations of skeletal functional morphology from biomechanical analyses.
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Affiliation(s)
- Michele M Bleuze
- Institutional affiliation: Department of Anthropology, California State University Los Angeles, Los Angeles, California, USA
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5
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Heck CT, Woodward HN. The consequences of calcium: investigating intracortical reproductive signals in the American alligator for sex determination. Anat Rec (Hoboken) 2024. [PMID: 38958219 DOI: 10.1002/ar.25533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 06/20/2024] [Accepted: 06/22/2024] [Indexed: 07/04/2024]
Abstract
Identifying sex in extinct archosaurs has proven difficult due, in part, to low sample sizes, preservation biases, and methodology. While previous studies have largely focused on morphological traits, here we investigate intracortical signals of egg-shelling in extant alligators. Egg-shelling requires large mobilizations of calcium reserves. Aves utilize medullary tissue as a calcium reserve, whereas crocodylians mobilize calcium from cortical bone or osteoderms. If crocodylians derive calcium from bone cortices for egg-shelling, then egg-shelling events should be detectable in female crocodylian cortical bone. We examined mid-diaphyseal Alligator mississippiensis femoral bone cross-sections for signals of reproduction. Compaction and area of resorbed tissue were measured in femoral cross-sections from captive raised male (n = 10) and female (n = 29) A. mississippiensis of 26-27 years at age of death. This sample is more robust than previous studies, though reproductive history data is unknown. Femora from a small sample of wild caught male (n = 6) and female (n = 6) A. mississippiensis were also measured. Data were analyzed by pairwise t-tests between sex and captivity status. There was no significant difference in either compaction or resorbed tissue values between male and female alligators, regardless of habitat (wild or captive-raised). A reproductive signal was undetectable in this study and any quantifiable differences between sexes appears to be driven by size dimorphism. Cortical resorption rates in the femora of male and female alligators are reflective of normal aging processes and not indicative of egg-shelling during reproduction. Examination of younger alligators would clarify processes driving bone turnover during reproductively active years.
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Affiliation(s)
- Christian T Heck
- Oklahoma State University, Center for Health Sciences, Tulsa, Oklahoma, USA
| | - Holly N Woodward
- Oklahoma State University, Center for Health Sciences, Tulsa, Oklahoma, USA
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6
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Gerrits L, Bakker B, Hendriks LD, Engels S, Hammink R, Kouwer PHJ. Tailoring of Physical Properties in Macroporous Poly(isocyanopeptide) Cryogels. Biomacromolecules 2024; 25:3464-3474. [PMID: 38743442 PMCID: PMC11170948 DOI: 10.1021/acs.biomac.4c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024]
Abstract
Over the years, synthetic hydrogels have proven remarkably useful as cell culture matrixes to elucidate the role of the extracellular matrix (ECM) on cell behavior. Yet, their lack of interconnected macropores undermines the widespread use of hydrogels in biomedical applications. To overcome this limitation, cryogels, a class of macroporous hydrogels, are rapidly emerging. Here, we introduce a new, highly elastic, and tunable synthetic cryogel, based on poly(isocyanopeptides) (PIC). Introduction of methacrylate groups on PIC facilitated cryopolymerization through free-radical polymerization and afforded cryogels with an interconnected macroporous structure. We investigated which cryogelation parameters can be used to tune the architectural and mechanical properties of the PIC cryogels by systematically altering cryopolymerization temperature, polymer concentration, and polymer molecular weight. We show that for decreasing cryopolymerization temperatures, there is a correlation between cryogel pore size and stiffness. More importantly, we demonstrate that by simply varying the polymer concentration, we can selectively tune the compressive strength of PIC cryogels without affecting their architecture. This unique feature is highly useful for biomedical applications, as it facilitates decoupling of stiffness from other variables such as pore size. As such, PIC cryogels provide an interesting new biomaterial for scientists to unravel the role of the ECM in cellular functions.
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Affiliation(s)
- Lotte Gerrits
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen ,Netherlands
| | - Bram Bakker
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen ,Netherlands
| | - Lynn D. Hendriks
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen ,Netherlands
| | - Sjoerd Engels
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen ,Netherlands
| | - Roel Hammink
- Department
of Medical BioSciences,Radboudumc, Geert Grooteplein 26, 6525 GA Nijmegen, The Netherlands
- Division
of Immunotherapy, Oncode Institute, Radboud
University Medical Center, 6525 GA Nijmegen ,Netherlands
| | - Paul H. J. Kouwer
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Institute
for Chemical Immunology, 6525 GA Nijmegen ,Netherlands
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7
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Bregoli C, Biffi CA, Tuissi A, Buccino F. Effect of trabecular architectures on the mechanical response in osteoporotic and healthy human bone. Med Biol Eng Comput 2024:10.1007/s11517-024-03134-8. [PMID: 38822996 DOI: 10.1007/s11517-024-03134-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 05/18/2024] [Indexed: 06/03/2024]
Abstract
Research at the mesoscale bone trabeculae arrangement yields intriguing results that, due to their clinical resolution, can be applied in clinical field, contributing significantly to the diagnosis of bone-related diseases. While the literature offers quantitative morphometric parameters for a thorough characterization of the mesoscale bone network, there is a gap in understanding relationships among them, particularly in the context of various bone pathologies. This research aims to bridge these gaps by offering a quantitative evaluation of the interplay among morphometric parameters and mechanical response at mesoscale in osteoporotic and non-osteoporotic bones. Bone mechanical response, dependent on trabecular arrangement, is defined by apparent stiffness, computationally calculated using the Gibson-Ashby model. Key findings indicate that: (i) in addition to bone density, measured using X-ray absorptiometry, trabecular connectivity density, trabecular spacing and degree of anisotropy are crucial parameters for characterize osteoporosis state; (ii) apparent stiffness values exhibit strong correlations with bone density and connectivity density; (iii) connectivity density and degree of anisotropy result the best predictors of mechanical response. Despite the inherent heterogeneity in bone structure, suggesting the potential benefit of a larger sample size in the future, this approach presents a valuable method to enhance discrimination between osteoporotic and non-osteoporotic samples.
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Affiliation(s)
- Chiara Bregoli
- National Research Council, CNR-ICMTE, Lecco, Italy.
- Mechanical Engineering Department, Politecnico Di Milano, Milano, Italy.
| | | | | | - Federica Buccino
- Mechanical Engineering Department, Politecnico Di Milano, Milano, Italy
- IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
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8
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Riberti N, D’Amico E, Pierfelice TV, Furlani M, Giuliani A, Piattelli A, Iezzi G, Comuzzi L. Case Report of a Dental Implant with Conometric Abutment-Prosthetic Cap Connection: Advanced High-Resolution Imaging and Peri-Implant Connective Tissue Performance. Clin Pract 2024; 14:556-569. [PMID: 38666801 PMCID: PMC11049280 DOI: 10.3390/clinpract14020043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/19/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Background: In recent years, the use of conometric systems to connect dental implant abutments and prosthetic caps has been advocated because they seem to eliminate the side effects reported when using screw- and cement-connected prosthetic restorations. Objectives: The present case study is focused on conometric connection characterization and its performance in terms of the microarchitecture of peri-implant soft tissues by using a cross-linked approach based on optical microscopy and three-dimensional imaging. Methods: Two dental implants were characterized using micro-CT and another identical one was implanted into a patient; the latter was retrieved 45 days later due to changes in prosthetic needs. Afterward, the peri-implant soft tissues were investigated using synchrotron-based phase contrast imaging, histology, and polarized light microscopy. Results: Micro-CT analysis showed perfect adhesion between the abutment and prosthetic cap; histology and polarized light microscopy showed that connective tissue was richly present around the abutment retrieved from the patient. Moreover, the quantitative evaluation of connective tissues using synchrotron imaging, supported by artificial intelligence, revealed that this tissue was rich in mature collagen, with longitudinal and transverse collagen bundles intertwined. The number and connectivity of transverse bundles were consistently greater than those of the longitudinal bundles. Conclusion: It was found that the peri-implant soft tissue was already mature and well organized after only 45 days of implantation, supporting the hypothesis that conometric connections contribute to the significant stabilization of peri-implant soft tissues.
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Affiliation(s)
- Nicole Riberti
- Neuroscience, Imaging and Clinical Sciences Department, University of Chieti-Pescara, 66100 Chieti, Italy;
| | - Emira D’Amico
- Medical, Oral and Biotechnological Sciences Department, University of Chieti-Pescara, 66100 Chieti, Italy; (E.D.); (T.V.P.); (G.I.)
| | - Tania Vanessa Pierfelice
- Medical, Oral and Biotechnological Sciences Department, University of Chieti-Pescara, 66100 Chieti, Italy; (E.D.); (T.V.P.); (G.I.)
| | - Michele Furlani
- Odontostomatologic and Specialized Clinical Sciences Department, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy;
| | - Alessandra Giuliani
- Odontostomatologic and Specialized Clinical Sciences Department, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy;
| | - Adriano Piattelli
- School of Dentistry, Saint Camillus International University for Health Sciences (Unicamillus), 00131 Rome, Italy;
| | - Giovanna Iezzi
- Medical, Oral and Biotechnological Sciences Department, University of Chieti-Pescara, 66100 Chieti, Italy; (E.D.); (T.V.P.); (G.I.)
| | - Luca Comuzzi
- Independent Researcher, Via Raffaello 36/a, 31020 San Vendemiano (TV), Italy;
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9
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Liu C, Cyphert EL, Stephen SJ, Wang B, Morales AL, Nixon JC, Natsoulas NR, Garcia M, Blazquez Carmona P, Vill AC, Donnelly EL, Brito IL, Vashishth D, Hernandez CJ. Microbiome-induced Increases and Decreases in Bone Tissue Strength can be Initiated After Skeletal Maturity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.574074. [PMID: 38260539 PMCID: PMC10802367 DOI: 10.1101/2024.01.03.574074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Recent studies in mice have indicated that the gut microbiome can regulate bone tissue strength. However, prior work involved modifications to the gut microbiome in growing animals and it is unclear if the same changes in the microbiome, applied later in life, would change matrix strength. Here we changed the composition of the gut microbiome before and/or after skeletal maturity (16 weeks of age) using oral antibiotics (ampicillin + neomycin). Male and female mice (n=143 total, n=12-17/group/sex) were allocated into five study groups:1) Unaltered, 2) Continuous (dosing 4-24 weeks of age), 3) Delayed (dosing only 16-24 weeks of age), 4) Initial (dosing 4-16 weeks of age, suspended at 16 weeks), and 5) Reconstituted (dosing from 4-16 weeks following by fecal microbiota transplant from Unaltered donors). Animals were euthanized at 24 weeks of age. In males, bone matrix strength in the femur was 25-35% less than expected from geometry in mice from the Continuous (p= 0.001), Delayed (p= 0.005), and Initial (p=0.040) groups as compared to Unaltered. Reconstitution of the gut microbiota, however, led to a bone matrix strength similar to Unaltered animals (p=0.929). In females, microbiome-induced changes in bone matrix strength followed the same trend as males but were not significantly different, demonstrating sex-related differences in the response of bone matrix to the gut microbiota. Minor differences in chemical composition of bone matrix were observed (Raman spectroscopy). Our findings indicate that microbiome-induced impairment of bone matrix in males can be initiated and/or reversed after skeletal maturity. The portion of the femoral cortical bone formed after skeletal maturity (16 weeks) is small; however, this suggests that microbiome-induced changes in bone matrix occur without osteoblast/osteoclast turnover using an, as of yet unidentified mechanism. These findings add to evidence that the mechanical properties of bone matrix can be altered in the adult skeleton.
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Affiliation(s)
- C Liu
- Departments of Orthopaedic Surgery and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - E L Cyphert
- Departments of Orthopaedic Surgery and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - S J Stephen
- Shirley Ann Jackson, PhD Center for Biotechnology and Interdisciplinary Studies, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - B Wang
- Shirley Ann Jackson, PhD Center for Biotechnology and Interdisciplinary Studies, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - A L Morales
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - J C Nixon
- Departments of Orthopaedic Surgery and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
- Shirley Ann Jackson, PhD Center for Biotechnology and Interdisciplinary Studies, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Spain
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
- Department of Material Science and Engineering, Cornell University, Ithaca, NY, USA
- Reseach Division, Hospital for Special Surgery, New York, NY, USA
- Rensselaer - Icahn School of Medicine at Mount Sinai Center for Engineering and Precision Medicine, New York, NY
- Chan Zuckerberg Biohub San Francisco, CA, US
| | - N R Natsoulas
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - M Garcia
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | | | - A C Vill
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - E L Donnelly
- Department of Material Science and Engineering, Cornell University, Ithaca, NY, USA
- Reseach Division, Hospital for Special Surgery, New York, NY, USA
| | - I L Brito
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - D Vashishth
- Shirley Ann Jackson, PhD Center for Biotechnology and Interdisciplinary Studies, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
- Rensselaer - Icahn School of Medicine at Mount Sinai Center for Engineering and Precision Medicine, New York, NY
| | - C J Hernandez
- Departments of Orthopaedic Surgery and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA
- Chan Zuckerberg Biohub San Francisco, CA, US
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10
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Marín-Aguilar S, Camerin F, van der Ham S, Feasson A, Vutukuri HR, Dijkstra M. A colloidal viewpoint on the sausage catastrophe and the finite sphere packing problem. Nat Commun 2023; 14:7896. [PMID: 38036561 PMCID: PMC10689752 DOI: 10.1038/s41467-023-43722-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/16/2023] [Indexed: 12/02/2023] Open
Abstract
It is commonly believed that the most efficient way to pack a finite number of equal-sized spheres is by arranging them tightly in a cluster. However, mathematicians have conjectured that a linear arrangement may actually result in the densest packing. Here, our combined experimental and simulation study provides a physical realization of the finite sphere packing problem by studying arrangements of colloids in a flaccid lipid vesicle. We map out a state diagram displaying linear, planar, and cluster conformations of spheres, as well as bistable states which alternate between cluster-plate and plate-linear conformations due to membrane fluctuations. Finally, by systematically analyzing truncated polyhedral packings, we identify clusters of 56 ≤ N ≤ 70 number of spheres, excluding N = 57 and 63, that pack more efficiently than linear arrangements.
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Affiliation(s)
- Susana Marín-Aguilar
- Soft Condensed Matter & Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht, 3584 CC, Utrecht, The Netherlands.
| | - Fabrizio Camerin
- Soft Condensed Matter & Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht, 3584 CC, Utrecht, The Netherlands.
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM²), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Hiroshima, Japan.
| | - Stijn van der Ham
- Active Soft Matter and Bio-inspired Materials Lab, Faculty of Science and Technology, MESA+ Institute, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Andréa Feasson
- Active Soft Matter and Bio-inspired Materials Lab, Faculty of Science and Technology, MESA+ Institute, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Hanumantha Rao Vutukuri
- Active Soft Matter and Bio-inspired Materials Lab, Faculty of Science and Technology, MESA+ Institute, University of Twente, 7500 AE, Enschede, The Netherlands.
| | - Marjolein Dijkstra
- Soft Condensed Matter & Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht, 3584 CC, Utrecht, The Netherlands.
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM²), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Hiroshima, Japan.
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Anderson C, Ntala C, Ozel A, Reuben RL, Chen Y. Computational homogenization of histological microstructures in human prostate tissue: Heterogeneity, anisotropy and tension-compression asymmetry. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3758. [PMID: 37477174 PMCID: PMC10909480 DOI: 10.1002/cnm.3758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 03/21/2023] [Accepted: 07/01/2023] [Indexed: 07/22/2023]
Abstract
Human prostatic tissue exhibits complex mechanical behaviour due to its multiphasic, heterogeneous nature, with hierarchical microstructures involving epithelial compartments, acinar lumens and stromal tissue all interconnected in complex networks. This study aims to establish a computational homogenization framework for quantifying the mechanical behaviour of prostate tissue, considering its multiphasic heterogeneous microstructures and the mechanical characteristics of tissue constituents. Representative tissue microstructure models were reconstructed from high-resolution histology images. Parametric studies on the mechanical properties of the tissue constituents, particularly the fibre-reinforced hyper-elasticity of the stromal tissue, were carried out to investigate their effects on the apparent tissue properties. These were then benchmarked against the experimental data reported in literature. Results showed significant anisotropy, both structural and mechanical, and tension-compression asymmetry of the apparent behaviours of the prostatic tissue. Strong correlation with the key microstructural indices such as area fractions of tissue constituents and the tissue fabric tensor was also observed. The correlation between the stromal tissue orientation and the principal directions of the apparent properties suggested an essential role of stromal tissue in determining the directions of anisotropy and the compression-tension asymmetry characteristics in normal human prostatic tissue. This work presented a homogenization and histology-based computational approach to characterize the apparent mechanical behaviours of human prostatic or other similar glandular tissues, with the ultimate aim of assessing how pathological conditions (e.g., prostate cancer and benign prostatic hyperplasia) could affect the tissue mechanical properties in a future study.
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Affiliation(s)
- Calum Anderson
- Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical SciencesHeriot‐Watt UniversityEdinburghUK
| | - Chara Ntala
- Department of Pathology, Western General HospitalUniversity of EdinburghEdinburghUK
| | - Ali Ozel
- Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical SciencesHeriot‐Watt UniversityEdinburghUK
| | - Robert L. Reuben
- Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical SciencesHeriot‐Watt UniversityEdinburghUK
| | - Yuhang Chen
- Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical SciencesHeriot‐Watt UniversityEdinburghUK
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Che VL, Zimmermann J, Zhou Y, Lu XL, van Rienen U. Contributions of deep learning to automated numerical modelling of the interaction of electric fields and cartilage tissue based on 3D images. Front Bioeng Biotechnol 2023; 11:1225495. [PMID: 37711443 PMCID: PMC10497969 DOI: 10.3389/fbioe.2023.1225495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/07/2023] [Indexed: 09/16/2023] Open
Abstract
Electric fields find use in tissue engineering but also in sensor applications besides the broad classical application range. Accurate numerical models of electrical stimulation devices can pave the way for effective therapies in cartilage regeneration. To this end, the dielectric properties of the electrically stimulated tissue have to be known. However, knowledge of the dielectric properties is scarce. Electric field-based methods such as impedance spectroscopy enable determining the dielectric properties of tissue samples. To develop a detailed understanding of the interaction of the employed electric fields and the tissue, fine-grained numerical models based on tissue-specific 3D geometries are considered. A crucial ingredient in this approach is the automated generation of numerical models from biomedical images. In this work, we explore classical and artificial intelligence methods for volumetric image segmentation to generate model geometries. We find that deep learning, in particular the StarDist algorithm, permits fast and automatic model geometry and discretisation generation once a sufficient amount of training data is available. Our results suggest that already a small number of 3D images (23 images) is sufficient to achieve 80% accuracy on the test data. The proposed method enables the creation of high-quality meshes without the need for computer-aided design geometry post-processing. Particularly, the computational time for the geometrical model creation was reduced by half. Uncertainty quantification as well as a direct comparison between the deep learning and the classical approach reveal that the numerical results mainly depend on the cell volume. This result motivates further research into impedance sensors for tissue characterisation. The presented approach can significantly improve the accuracy and computational speed of image-based models of electrical stimulation for tissue engineering applications.
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Affiliation(s)
- Vien Lam Che
- Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
| | - Julius Zimmermann
- Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
| | - Yilu Zhou
- Department of Mechanical Engineering, University of Delaware, Delaware, DE, United States
| | - X. Lucas Lu
- Department of Mechanical Engineering, University of Delaware, Delaware, DE, United States
| | - Ursula van Rienen
- Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
- Department Life, Light and Matter, University of Rostock, Rostock, Germany
- Department of Ageing of Individuals and Society, Interdisciplinary Faculty, University of Rostock, Rostock, Germany
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13
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Warmink K, Rios JL, van Valkengoed DR, Vinod P, Korthagen NM, Weinans H. Effects of different obesogenic diets on joint integrity, inflammation and intermediate monocyte levels in a rat groove model of osteoarthritis. Front Physiol 2023; 14:1211972. [PMID: 37520829 PMCID: PMC10372350 DOI: 10.3389/fphys.2023.1211972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/05/2023] [Indexed: 08/01/2023] Open
Abstract
Introduction: Obesogenic diets aggravate osteoarthritis (OA) by inducing low-grade systemic inflammation, and diet composition may affect OA severity. Here, we investigated the effect of diet on joint damage and inflammation in an OA rat model. Methods: Wistar-Han rats (n = 24) were fed a chow, a high-fat (HF) diet, or a high-fat/high-sucrose (HFS) for 24 weeks. OA was induced unilaterally 12 weeks after the diet onset by groove surgery, and compared to sham surgery or no surgical intervention (contralateral limb). Knee OA severity was determined by OARSI histopathology scoring system. At several timepoints monocyte populations were measured using flow cytometry, and joint macrophage response was determined via CD68 immunohistochemistry staining. Results: Groove surgery combined with HF or HFS diet resulted in higher OARSI scores, and both HF and HFS diet showed increased circulating intermediate monocytes compared to chow fed rats. Additionally, in the HFS group, minimal damage by sham surgery resulted in an increased OARSI score. HFS diet resulted in the largest metabolic dysregulation, synovial inflammation and increased CD68 staining in tibia epiphysis bone marrow. Conclusion: Obesogenic diets resulted in aggravated OA development, even with very minimal joint damage when combined with the sucrose/fat-rich diet. We hypothesize that diet-induced low-grade inflammation primes monocytes and macrophages in the blood, bone marrow, and synovium, resulting in joint damage when triggered by groove OA inducing surgery. When the metabolic dysregulation is larger, as observed here for the HFS diet, the surgical trigger required to induce joint damage may be smaller, or even redundant.
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Affiliation(s)
- K. Warmink
- Department of Orthopedics, University Medical Center Utrecht (UMCU), Utrecht, Netherlands
| | - J. L. Rios
- Department of Orthopedics, University Medical Center Utrecht (UMCU), Utrecht, Netherlands
| | - D. R. van Valkengoed
- Department of Orthopedics, University Medical Center Utrecht (UMCU), Utrecht, Netherlands
| | - P. Vinod
- Department of Orthopedics, University Medical Center Utrecht (UMCU), Utrecht, Netherlands
| | - N. M. Korthagen
- Department of Orthopedics, University Medical Center Utrecht (UMCU), Utrecht, Netherlands
- Department of Equine Sciences, Utrecht University, Utrecht, Netherlands
| | - H. Weinans
- Department of Orthopedics, University Medical Center Utrecht (UMCU), Utrecht, Netherlands
- Department of Biomechanical Engineering, TU Delft, Delft, Netherlands
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Püffel F, Meyer L, Imirzian N, Roces F, Johnston R, Labonte D. Developmental biomechanics and age polyethism in leaf-cutter ants. Proc Biol Sci 2023; 290:20230355. [PMID: 37312549 PMCID: PMC10265030 DOI: 10.1098/rspb.2023.0355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/05/2023] [Indexed: 06/15/2023] Open
Abstract
Many social insects display age polyethism: young workers stay inside the nest, and only older workers forage. This behavioural transition is accompanied by genetic and physiological changes, but the mechanistic origin of it remains unclear. To investigate if the mechanical demands on the musculoskeletal system effectively prevent young workers from foraging, we studied the biomechanical development of the bite apparatus in Atta vollenweideri leaf-cutter ants. Fully matured foragers generated peak in vivo bite forces of around 100 mN, more than one order of magnitude in excess of those measured for freshly eclosed callows of the same size. This change in bite force was accompanied by a sixfold increase in the volume of the mandible closer muscle, and by a substantial increase of the flexural rigidity of the head capsule, driven by a significant increase in both average thickness and indentation modulus of the head capsule cuticle. Consequently, callows lack the muscle force capacity required for leaf-cutting, and their head capsule is so compliant that large muscle forces would be likely to cause damaging deformations. On the basis of these results, we speculate that continued biomechanical development post eclosion may be a key factor underlying age polyethism, wherever foraging is associated with substantial mechanical demands.
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Affiliation(s)
- Frederik Püffel
- Department of Bioengineering, Imperial College London, London, UK
| | - Lara Meyer
- Faculty of Nature and Engineering, City University of Applied Sciences Bremen, Bremen, Germany
| | - Natalie Imirzian
- Department of Bioengineering, Imperial College London, London, UK
| | - Flavio Roces
- Department of Behavioural Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
| | | | - David Labonte
- Department of Bioengineering, Imperial College London, London, UK
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15
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Corcoran E, Siles L, Kurup S, Ahnert S. Automated extraction of pod phenotype data from micro-computed tomography. FRONTIERS IN PLANT SCIENCE 2023; 14:1120182. [PMID: 36909425 PMCID: PMC9998914 DOI: 10.3389/fpls.2023.1120182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Plant image datasets have the potential to greatly improve our understanding of the phenotypic response of plants to environmental and genetic factors. However, manual data extraction from such datasets are known to be time-consuming and resource intensive. Therefore, the development of efficient and reliable machine learning methods for extracting phenotype data from plant imagery is crucial. METHODS In this paper, a current gold standard computed vision method for detecting and segmenting objects in three-dimensional imagery (StartDist-3D) is applied to X-ray micro-computed tomography scans of oilseed rape (Brassica napus) mature pods. RESULTS With a relatively minimal training effort, this fine-tuned StarDist-3D model accurately detected (Validation F1-score = 96.3%,Testing F1-score = 99.3%) and predicted the shape (mean matched score = 90%) of seeds. DISCUSSION This method then allowed rapid extraction of data on the number, size, shape, seed spacing and seed location in specific valves that can be integrated into models of plant development or crop yield. Additionally, the fine-tuned StarDist-3D provides an efficient way to create a dataset of segmented images of individual seeds that could be used to further explore the factors affecting seed development, abortion and maturation synchrony within the pod. There is also potential for the fine-tuned Stardist-3D method to be applied to imagery of seeds from other plant species, as well as imagery of similarly shaped plant structures such as beans or wheat grains, provided the structures targeted for detection and segmentation can be described as star-convex polygons.
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Affiliation(s)
- Evangeline Corcoran
- Environment and Sustainability Theme, AI for Science and Government Programme, The Alan Turing Institute, London, United Kingdom
| | - Laura Siles
- Department of Plant Sciences for the Bioeconomy, Rothamsted Research, Harpenden, United Kingdom
| | - Smita Kurup
- Department of Plant Sciences for the Bioeconomy, Rothamsted Research, Harpenden, United Kingdom
| | - Sebastian Ahnert
- Environment and Sustainability Theme, AI for Science and Government Programme, The Alan Turing Institute, London, United Kingdom
- Department of Chemical Engineering and Biotechnology, School of Technology, University of Cambridge, Cambridge, United Kingdom
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16
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Quantitative estimation of closed cell porosity in low density ceramic composites using X-ray microtomography. Sci Rep 2023; 13:127. [PMID: 36599870 DOI: 10.1038/s41598-022-27114-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/26/2022] [Indexed: 01/06/2023] Open
Abstract
X-ray Microtomography is a proven tool for phase fraction analysis of multi-phase systems, provided that each phase is adequately partitioned by some means of data processing. For porosity in materials containing low-density ceramic phases, differentiation between pores and the low-density phase(s) can be intractable due to low scattering in the low-density phase, particularly if small pores necessitate low binning. We present a novel, combined methodology for accurate porosity analysis-despite these shortcomings. A 3-stage process is proposed, consisting of (1) Signal/noise enhancement using non-local means denoising, (2) Phase segmentation using a convolutional neural network, and (3) Quantitative analysis of the resulting 3D pore metrics. This particular combination of denoising and segmentation is robust against the fragmentation of common segmentation algorithms, while avoiding the volitional aspects of model selection associated with histogram fitting. We discuss the procedure applied to ternary phase SiC-TiC-diamond composites produced by reactive spark plasma sintering with porosity spanning 2-9 vol%.
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Brent MB, Emmanuel T. Contemporary Advances in Computer-Assisted Bone Histomorphometry and Identification of Bone Cells in Culture. Calcif Tissue Int 2023; 112:1-12. [PMID: 36309622 DOI: 10.1007/s00223-022-01035-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/13/2022] [Indexed: 01/07/2023]
Abstract
Static and dynamic bone histomorphometry and identification of bone cells in culture are labor-intensive and highly repetitive tasks. Several computer-assisted methods have been proposed to ease these tasks and to take advantage of the increased computational power available today. The present review aimed to provide an overview of contemporary methods utilizing specialized computer software to perform bone histomorphometry or identification of bone cells in culture. In addition, a brief historical perspective on bone histomorphometry is included. We identified ten publications using five different computer-assisted approaches (1) ImageJ and BoneJ; (2) Histomorph: OsteoidHisto, CalceinHisto, and TrapHisto; (3) Fiji/ImageJ2 and Trainable Weka Segmentation (TWS); (4) Visiopharm and artificial intelligence (AI); and (5) Osteoclast identification using deep learning with Single Shot Detection (SSD) architecture, Darknet and You Only Look Once (YOLO), or watershed algorithm (OC_Finder). The review also highlighted a substantial need for more validation studies that evaluate the accuracy of the new computational methods to the manual and conventional analyses of histological bone specimens and cells in culture using microscopy. However, a substantial evolution has occurred during the last decade to identify and separate bone cells and structures of interest. Most early studies have used simple image segmentation to separate structures of interest, whereas the most recent studies have utilized AI and deep learning. AI has been proposed to substantially decrease the amount of time needed for analyses and enable unbiased assessments. Despite the clear advantages of highly sophisticated computational methods, the limited nature of existing validation studies, particularly those that assess the accuracy of the third-generation methods compared to the second-generation methods, appears to be an important reason that these techniques have failed to gain wide acceptance.
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Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 3, 8000, Aarhus, Denmark.
| | - Thomas Emmanuel
- Department of Dermatology, Aarhus University Hospital, 8200, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, 8200, Aarhus, Denmark
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Lichtenberg M, Kvich L, Larsen SLB, Jakobsen TH, Bjarnsholt T. Inoculum Concentration Influences Pseudomonas aeruginosa Phenotype and Biofilm Architecture. Microbiol Spectr 2022; 10:e0313122. [PMID: 36354337 PMCID: PMC9769529 DOI: 10.1128/spectrum.03131-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/21/2022] [Indexed: 11/12/2022] Open
Abstract
In infections, bacterial cells are often found as relatively small multicellular aggregates characterized by a heterogeneous distribution of phenotype, genotype, and growth rates depending on their surrounding microenvironment. Many laboratory models fail to mimic these characteristics, and experiments are often initiated from planktonic bacteria given optimal conditions for rapid growth without concerns about the microenvironmental characteristics during biofilm maturation. Therefore, we investigated how the initial bacterial concentration (henceforth termed the inoculum) influences the microenvironment during initial growth and how this affects the sizes and distribution of developed aggregates in an embedded biofilm model-the alginate bead biofilm model. Following 24 h of incubation, the viable biomass was independent of starting inoculum but with a radically different microenvironment which led to differences in metabolic activity depending on the inoculum. The inoculum also affected the number of cells surviving treatment with the antibiotic tobramycin, where the highest inoculum showed higher survival rates than the lowest inoculum. The change in antibiotic tolerance was correlated with cell-specific RNA content and O2 consumption rates, suggesting a direct role of metabolic activity. Thus, the starting number of bacteria results in different phenotypic trajectories governed by different microenvironmental characteristics, and we demonstrate some of the possible implications of such physiological gradients on the outcome of in vitro experiments. IMPORTANCE Biofilm aggregates grown in the alginate bead biofilm model bear resemblance to features of in vivo biofilms. Here, we show that changing the initial concentration of bacteria in the biofilm model leads to widely different behavior of the bacteria following an incubation period. This difference is influenced by the local conditions experienced by the bacteria during growth, which impact their response to antibiotic treatment. Our study provides a framework for manipulating aggregate sizes in in vitro biofilm models. It underlines the importance of how experiments are initiated, which can profoundly impact the outcomes and interpretation of microbiological experiments.
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Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Lasse Kvich
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Sara Louise Borregaard Larsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
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Duvančić T, Škokić S, Erjavec I, Plečko M, Bohaček I, Gajović S, Delimar D. Novel micro-MRI approach for subchondral trabecular bone analysis in patients with hip osteoarthritis is comparable to micro-CT approach. Croat Med J 2022; 63:515-524. [PMID: 36597563 PMCID: PMC9837720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
AIM To test the agreement between a newly developed micro-magnetic resonance imaging (MRI) analysis of the subchondral bone and the micro-computed tomography (CT) approach. METHODS Samples obtained from 10 patients with osteoarthritis undergoing total hip arthroplasty were scanned with a 7.0 T micro-MRI. Proton density-weighted images and proton density-weighted images with fat suppression were obtained. The results were validated with a micro-CT device. Micro-MRI and micro-CT scans of the same sample were aligned, and regions of interest were delineated on equal areas of the sample. Bone volume fraction was calculated by using in-house plugins. The agreement between the methods was tested with Bland-Altman analysis. RESULTS The agreement between the methods was good, with average difference of 2.167%. The differences between the methods were not significant (P=0.272, t test). CONCLUSION The novel micro-MRI approach could be used for subchondral bone analysis. With further optimization for clinical MRI machines, the approach can be also used in the diagnostics of hip osteoarthritis.
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Affiliation(s)
- Tea Duvančić
- University of Zagreb School of Medicine, Zagreb, Croatia
| | - Siniša Škokić
- Laboratory for Regenerative Neuroscience – GlowLab, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Igor Erjavec
- University of Zagreb School of Medicine, Zagreb, Croatia
| | | | - Ivan Bohaček
- Department of Orthopedic Surgery, University of Zagreb School of Medicine, University Hospital Center Zagreb, Zagreb, Croatia
| | - Srećko Gajović
- University of Zagreb School of Medicine, Zagreb, Croatia
| | - Domagoj Delimar
- Department of Orthopedic Surgery, University of Zagreb School of Medicine, University Hospital Center Zagreb, Zagreb, Croatia
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Localized, time-dependent responses of rat cranial bone to repeated mild traumatic brain injuries. Sci Rep 2022; 12:14175. [PMID: 36050485 PMCID: PMC9437056 DOI: 10.1038/s41598-022-18643-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
While it is well-established that bone responds dynamically to mechanical loading, the effects of mild traumatic brain injury (mTBI) on cranial bone composition are unclear. We hypothesized that repeated mTBI (rmTBI) would change the microstructure of cranial bones, without gross skull fractures. To address this, young adult female Piebald Viral Glaxo rats received sham, 1×, 2× or 3× closed-head mTBIs delivered at 24 h intervals, using a weight-drop device custom-built for reproducible impact. Skull bones were collected at 2 or 10 weeks after the final injury/sham procedure, imaged by micro computed tomography and analyzed at predetermined regions of interest. In the interparietal bone, proximal to the injury site, modest increases in bone thickness were observed at 2 weeks, particularly following 2× and 3× mTBI. By 10 weeks, 2× mTBI induced a robust increase in the volume and thickness of the interparietal bone, alongside a corresponding decrease in the volume of marrow cavities in the diploë region. In contrast, neither parietal nor frontal skull samples were affected by rmTBI. Our findings demonstrate time- and location-dependent effects of rmTBI on cranial bone structure, highlighting a need to consider microstructural alterations to cranial bone when assessing the consequences of rmTBI.
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Sommer NG, Hirzberger D, Paar L, Berger L, Ćwieka H, Schwarze UY, Herber V, Okutan B, Bodey AJ, Willumeit-Römer R, Zeller-Plumhoff B, Löffler JF, Weinberg AM. Implant degradation of low-alloyed Mg-Zn-Ca in osteoporotic, old and juvenile rats. Acta Biomater 2022; 147:427-438. [PMID: 35644328 DOI: 10.1016/j.actbio.2022.05.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/27/2022] [Accepted: 05/23/2022] [Indexed: 11/27/2022]
Abstract
Implant removal is unnecessary for biodegradable magnesium (Mg)-based implants and, therefore, the related risk for implant-induced fractures is limited. Aging, on the other hand, is associated with low bone-turnover and decreased bone mass and density, and thus increased fracture risk. Osteoporosis is accompanied by Mg deficiency, therefore, we hypothesized that Mg-based implants may support bone formation by Mg2+ ion release in an ovariectomy-induced osteoporotic rat model. Hence, we investigated osseointegration and implant degradation of a low-alloyed, degrading Mg-Zn-Ca implant (ZX00) in ovariectomy-induced osteoporotic (Osteo), old healthy (OH), and juvenile healthy (JH) groups of female Sprague Dawley rats via in vivo micro-computed tomography (µCT). For the Osteo rats, we demonstrate diminished trabecular bone already after 8 weeks upon ovariectomy and significantly enhanced implant volume loss, with correspondingly pronounced gas formation, compared to the OH and JH groups. Sclerotic rim development was observed in about half of the osteoporotic rats, suggesting a prevention from foreign-body and osteonecrosis development. Synchrotron radiation-based µCT confirmed lower bone volume fractions in the Osteo group compared to the OH and JH groups. Qualitative histological analysis additionally visualized the enhanced implant degradation in the Osteo group. To date, ZX00 provides an interesting implant material for young and older healthy patients, but it may not be of advantage in pharmacologically untreated osteoporotic conditions. STATEMENT OF SIGNIFICANCE: Magnesium-based implants are promising candidates for treatment of osteoporotic fractures because of their biodegradable, biomechanical, anti-bacterial and bone regenerative properties. Here we investigate magnesium‒zinc‒calcium implant materials in a rat model with ovariectomy-induced osteoporosis (Osteo group) and compare the related osseointegration and implant degradation with the results obtained for old healthy (OH) and juvenile healthy (JH) rats. The work applied an appropriate disease model for osteoporosis and focused in particular on long-term implant degradation for different bone conditions. Enhanced implant degradation and sclerotic rim formation was observed in osteoporotic rats, which illustrates that the setting of different bone models generates significantly modified clinical outcome. It further illustrated that these differences must be taken into account in future biodegradable implant development.
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Borsuk AM, Roddy AB, Théroux‐Rancourt G, Brodersen CR. Structural organization of the spongy mesophyll. THE NEW PHYTOLOGIST 2022; 234:946-960. [PMID: 35037256 PMCID: PMC9303971 DOI: 10.1111/nph.17971] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/21/2021] [Indexed: 05/21/2023]
Abstract
Many plant leaves have two layers of photosynthetic tissue: the palisade and spongy mesophyll. Whereas palisade mesophyll consists of tightly packed columnar cells, the structure of spongy mesophyll is not well characterized and often treated as a random assemblage of irregularly shaped cells. Using micro-computed tomography imaging, topological analysis, and a comparative physiological framework, we examined the structure of the spongy mesophyll in 40 species from 30 genera with laminar leaves and reticulate venation. A spectrum of spongy mesophyll diversity encompassed two dominant phenotypes: first, an ordered, honeycomblike tissue structure that emerged from the spatial coordination of multilobed cells, conforming to the physical principles of Euler's law; and second, a less-ordered, isotropic network of cells. Phenotypic variation was associated with transitions in cell size, cell packing density, mesophyll surface-area-to-volume ratio, vein density, and maximum photosynthetic rate. These results show that simple principles may govern the organization and scaling of the spongy mesophyll in many plants and demonstrate the presence of structural patterns associated with leaf function. This improved understanding of mesophyll anatomy provides new opportunities for spatially explicit analyses of leaf development, physiology, and biomechanics.
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Affiliation(s)
| | - Adam B. Roddy
- Department of Biological SciencesInstitute of EnvironmentFlorida International UniversityMiamiFL33199USA
| | - Guillaume Théroux‐Rancourt
- Department of Integrative Biology and Biodiversity ResearchInstitute of BotanyUniversity of Natural Resources and Life Sciences, Vienna1180ViennaAustria
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23
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Jin D, Zheng H, Zhao Q, Wang C, Zhang M, Yuan H. Generation of Vertebra Micro-CT-like Image from MDCT: A Deep-Learning-Based Image Enhancement Approach. Tomography 2021; 7:767-782. [PMID: 34842849 PMCID: PMC8628970 DOI: 10.3390/tomography7040064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 11/26/2022] Open
Abstract
This paper proposes a deep-learning-based image enhancement approach that can generate high-resolution micro-CT-like images from multidetector computed tomography (MDCT). A total of 12,500 MDCT and micro-CT image pairs were obtained from 25 vertebral specimens. Then, a pix2pixHD model was trained and evaluated using the structural similarity index measure (SSIM) and Fréchet inception distance (FID). We performed subjective assessments of the micro-CT-like images based on five aspects. Micro-CT and micro-CT-like image-derived trabecular bone microstructures were compared, and the underlying correlations were analyzed. The results showed that the pix2pixHD method (SSIM, 0.804 ± 0.037 and FID, 43.598 ± 9.108) outperformed the two control methods (pix2pix and CRN) in enhancing MDCT images (p < 0.05). According to the subjective assessment, the pix2pixHD-derived micro-CT-like images showed no significant difference from the micro-CT images in terms of contrast and shadow (p > 0.05) but demonstrated slightly lower noise, sharpness and trabecular bone texture (p < 0.05). Compared with the trabecular microstructure parameters of micro-CT images, those of pix2pixHD-derived micro-CT-like images showed no significant differences in bone volume fraction (BV/TV) (p > 0.05) and significant correlations in trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp) (Tb.Th, R = 0.90, p < 0.05; Tb.Sp, R = 0.88, p < 0.05). The proposed method can enhance the resolution of MDCT and obtain micro-CT-like images, which may provide new diagnostic criteria and a predictive basis for osteoporosis and related fractures.
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Affiliation(s)
- Dan Jin
- Department of Radiology, Peking University Third Hospital, Beijing 100191, China; (D.J.); (Q.Z.); (C.W.); (M.Z.)
| | - Han Zheng
- School of Traffic and Transportation, Beijing Jiaotong University, Beijing 100044, China;
| | - Qingqing Zhao
- Department of Radiology, Peking University Third Hospital, Beijing 100191, China; (D.J.); (Q.Z.); (C.W.); (M.Z.)
| | - Chunjie Wang
- Department of Radiology, Peking University Third Hospital, Beijing 100191, China; (D.J.); (Q.Z.); (C.W.); (M.Z.)
| | - Mengze Zhang
- Department of Radiology, Peking University Third Hospital, Beijing 100191, China; (D.J.); (Q.Z.); (C.W.); (M.Z.)
| | - Huishu Yuan
- Department of Radiology, Peking University Third Hospital, Beijing 100191, China; (D.J.); (Q.Z.); (C.W.); (M.Z.)
- Correspondence:
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24
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Hypoxia induces stress fiber formation in adipocytes in the early stage of obesity. Sci Rep 2021; 11:21473. [PMID: 34728615 PMCID: PMC8563745 DOI: 10.1038/s41598-021-00335-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 10/07/2021] [Indexed: 02/07/2023] Open
Abstract
In obese adipose tissue (AT), hypertrophic expansion of adipocytes is not matched by new vessel formation, leading to AT hypoxia. As a result, hypoxia inducible factor-1⍺ (HIF-1⍺) accumulates in adipocytes inducing a transcriptional program that upregulates profibrotic genes and biosynthetic enzymes such as lysyl oxidase (LOX) synthesis. This excess synthesis and crosslinking of extracellular matrix (ECM) components cause AT fibrosis. Although fibrosis is a hallmark of obese AT, the role of fibroblasts, cells known to regulate fibrosis in other fibrosis-prone tissues, is not well studied. Here we have developed an in vitro model of AT to study adipocyte-fibroblast crosstalk in a hypoxic environment. Further, this in vitro model was used to investigate the effect of hypoxia on adipocyte mechanical properties via ras homolog gene family member A (RhoA)/Rho-associated coiled-coil kinases (ROCK) signaling pathways. We confirmed that hypoxia creates a diseased phenotype by inhibiting adipocyte maturation and inducing actin stress fiber formation facilitated by myocardin-related transcription factor A (MRTF-A/MKL1) nuclear translocation. This work presents new potential therapeutic targets for obesity by improving adipocyte maturation and limiting mechanical stress in obese AT.
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Beltran Diaz S, H'ng CH, Qu X, Doube M, Nguyen JT, de Veer M, Panagiotopoulou O, Rosello-Diez A. A New Pipeline to Automatically Segment and Semi-Automatically Measure Bone Length on 3D Models Obtained by Computed Tomography. Front Cell Dev Biol 2021; 9:736574. [PMID: 34513850 PMCID: PMC8427701 DOI: 10.3389/fcell.2021.736574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
The characterization of developmental phenotypes often relies on the accurate linear measurement of structures that are small and require laborious preparation. This is tedious and prone to errors, especially when repeated for the multiple replicates that are required for statistical analysis, or when multiple distinct structures have to be analyzed. To address this issue, we have developed a pipeline for characterization of long-bone length using X-ray microtomography (XMT) scans. The pipeline involves semi-automated algorithms for automatic thresholding and fast interactive isolation and 3D-model generation of the main limb bones, using either the open-source ImageJ plugin BoneJ or the commercial Mimics Innovation Suite package. The tests showed the appropriate combination of scanning conditions and analysis parameters yields fast and comparable length results, highly correlated with the measurements obtained via ex vivo skeletal preparations. Moreover, since XMT is not destructive, the samples can be used afterward for histology or other applications. Our new pipelines will help developmental biologists and evolutionary researchers to achieve fast, reproducible and non-destructive length measurement of bone samples from multiple animal species.
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Affiliation(s)
- Santiago Beltran Diaz
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Chee Ho H'ng
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Xinli Qu
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Michael Doube
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong, SAR China
| | - John Tan Nguyen
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Michael de Veer
- Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
| | - Olga Panagiotopoulou
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Alberto Rosello-Diez
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
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Herbst EC, Felder AA, Evans LAE, Ajami S, Javaheri B, Pitsillides AA. A new straightforward method for semi-automated segmentation of trabecular bone from cortical bone in diverse and challenging morphologies. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210408. [PMID: 34386254 PMCID: PMC8334830 DOI: 10.1098/rsos.210408] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Many physiological, biomechanical, evolutionary and clinical studies that explore skeletal structure and function require successful separation of trabecular from cortical compartments of a bone that has been imaged by X-ray micro-computed tomography (micro-CT) prior to analysis. Separation often involves manual subdivision of these two similarly radio-opaque compartments, which can be time-consuming and subjective. We have developed an objective, semi-automated protocol which reduces user bias and enables straightforward, user-friendly segmentation of trabecular from the cortical bone without requiring sophisticated programming expertise. This method can conveniently be used as a 'recipe' in commercial programmes (Avizo herein) and applied to a variety of datasets. Here, we characterize and share this recipe, and demonstrate its application to a range of murine and human bone types, including normal and osteoarthritic specimens, and bones with distinct embryonic origins and spanning a range of ages. We validate the method by testing inter-user bias during the scan preparation steps and confirm utility in the architecturally challenging analysis of growing murine epiphyses. We also report details of the recipe, so that other groups can readily re-create a similar method in open access programmes. Our aim is that this method will be adopted widely to create a reproducible and time-efficient method of segmenting trabecular and cortical bone.
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Affiliation(s)
- Eva C. Herbst
- Palaeontological Institute and Museum, University of Zurich, Zurich, Switzerland
| | - Alessandro A. Felder
- Research Software Development Group, Research IT Services, University College London, London, UK
| | - Lucinda A. E. Evans
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
| | - Sara Ajami
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Behzad Javaheri
- School of Mathematics, Computer Science and Engineering, City University of London, London, UK
| | - Andrew A. Pitsillides
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
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