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Zheng LD, Lv HY, Yang YT, Yuan Q, Cao YT, Zhang K, Zhu R. Effect of compressive and tensile forces on glucose concentration and cell viability within the intervertebral disc: A finite element study. Med Eng Phys 2024; 129:104189. [PMID: 38906572 DOI: 10.1016/j.medengphy.2024.104189] [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: 01/04/2024] [Revised: 05/09/2024] [Accepted: 05/22/2024] [Indexed: 06/23/2024]
Abstract
Understanding the role of mechanical force on tissue nutrient transport is essential, as sustained force may affect nutrient levels within the disc and initiate disc degeneration. This study aims to evaluate the time-dependent effects of different compressive force amplitudes as well as tensile force on glucose concentration and cell viability within the disc. Based on the mechano-electrochemical mixture theory, a multiphasic finite element model of the lumbar intervertebral disc was developed. The minimum glucose concentration and minimum cell density in both normal and degenerated discs were predicted for different compressive force amplitudes, tensile force, and corresponding creep time. Under high compressive force, the minimum glucose concentration exhibited an increasing and then decreasing trend with creep time in the normal disc, whereas that of the degenerated disc increased, then decreased, and finally increased again. At steady state, a higher compressive force was accompanied by a lower glucose concentration distribution. In the degenerated disc, the minimum cell density was negatively correlated with creep time, with a greater range of affected tissue under a higher compressive force. For tensile force, the minimum glucose concentration of the degenerated disc raised over time. This study highlighted the importance of creep time, force magnitude, and force type in affecting nutrient concentration and cell viability. Sustained weight-bearing activities could deteriorate the nutrient environment of the degenerated disc, while tensile force might have a nonnegligible role in effectively improving nutrient levels within the degenerated disc.
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Affiliation(s)
- Liang-Dong Zheng
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 200092, China
| | - Hao-Yang Lv
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 200092, China
| | - Yi-Ting Yang
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 200092, China
| | - Qing Yuan
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 200092, China; School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092, China
| | - Yu-Ting Cao
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 200092, China
| | - Kai Zhang
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092, China
| | - Rui Zhu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai 200092, China.
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Volz M, Elmasry S, Jackson AR, Travascio F. Computational Modeling Intervertebral Disc Pathophysiology: A Review. Front Physiol 2022; 12:750668. [PMID: 35095548 PMCID: PMC8793742 DOI: 10.3389/fphys.2021.750668] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/15/2021] [Indexed: 12/31/2022] Open
Abstract
Lower back pain is a medical condition of epidemic proportion, and the degeneration of the intervertebral disc has been identified as a major contributor. The etiology of intervertebral disc (IVD) degeneration is multifactorial, depending on age, cell-mediated molecular degradation processes and genetics, which is accelerated by traumatic or gradual mechanical factors. The complexity of such intertwined biochemical and mechanical processes leading to degeneration makes it difficult to quantitatively identify cause–effect relationships through experiments. Computational modeling of the IVD is a powerful investigative tool since it offers the opportunity to vary, observe and isolate the effects of a wide range of phenomena involved in the degenerative process of discs. This review aims at discussing the main findings of finite element models of IVD pathophysiology with a special focus on the different factors contributing to physical changes typical of degenerative phenomena. Models presented are subdivided into those addressing role of nutritional supply, progressive biochemical alterations stemming from an imbalance between anabolic and catabolic processes, aging and those considering mechanical factors as the primary source that induces morphological change within the disc. Limitations of the current models, as well as opportunities for future computational modeling work are also discussed.
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Affiliation(s)
- Mallory Volz
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Shady Elmasry
- Department of Biomechanics, Hospital for Special Surgery, New York, NY, United States
| | - Alicia R. Jackson
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Francesco Travascio
- Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL, United States
- Department of Orthopaedic Surgery, University of Miami, Miami, FL, United States
- Max Biedermann Institute for Biomechanics, Mount Sinai Medical Center, Miami Beach, FL, United States
- *Correspondence: Francesco Travascio,
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Tian D, Liu J, Chen L, Zhu B, Jing J. The protective effects of PI3K/Akt pathway on human nucleus pulposus mesenchymal stem cells against hypoxia and nutrition deficiency. J Orthop Surg Res 2020; 15:29. [PMID: 31992313 PMCID: PMC6988348 DOI: 10.1186/s13018-020-1551-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/09/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND To study the effects of hypoxia and nutrition deficiency mimicking degenerated intervertebral disc on the biological behavior of human nucleus-derived pulposus mesenchymal stem cells (hNP-MSCs) and the role of PI3K/Akt pathway in the process in vitro. METHODS hP-MSCs were isolated from lumbar disc and were further identified by their immunophenotypes and multilineage differentiation. Then, cells were divided into the control group, hypoxia and nutrition deficiency group, the LY294002 group, and insulin-like growth factor 1 (IGF-1) group. Then cell apoptosis, the cell viability, the caspase 3 activity, and the expression of PI3K, Akt, and functional genes (aggrecan, collagen I, and collagen II) were evaluated. RESULT Our work showed that isolated cells met the criteria of International Society for cellular Therapy. Therefore, cells obtained from degenerated nucleus pulposus were definitely hNP-MSCs. Our results showed that hypoxia and nutrition deficiency could significantly increase cell apoptosis, the caspase 3 activity, and inhibit cell viability. Gene expression results demonstrated that hypoxia and nutrition deficiency could increase the relative expression of PI3K and Akt gene and inhibit the expression of functional genes. However, when the PI3K/Akt pathway was inhibited by LY294002, the cell apoptosis and caspase 3 activity significantly increased while the cell viability was obviously inhibited. Quantitative real-time PCR results showed that the expression of functional genes was more significantly inhibited. Our study further verified that the above-mentioned biological activities of hNP-MSCs could be significantly improved by IGF1. CONCLUSIONS PI3K/Akt signal pathway may have protective effects on human nucleus pulposus-derived mesenchymal stem cells against hypoxia and nutrition deficiency.
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Affiliation(s)
- DaSheng Tian
- Department of Orthopaedics, The Second Affiliated Hospital of Anhui Medical University, 678#Fu Rong Road, Hefei, Anhui, 230601, People's Republic of China
| | - Jianjun Liu
- Department of Orthopaedics, The Second Affiliated Hospital of Anhui Medical University, 678#Fu Rong Road, Hefei, Anhui, 230601, People's Republic of China
| | - Lei Chen
- Department of Orthopaedics, The Second Affiliated Hospital of Anhui Medical University, 678#Fu Rong Road, Hefei, Anhui, 230601, People's Republic of China
| | - Bin Zhu
- Department of Orthopaedics, The Second Affiliated Hospital of Anhui Medical University, 678#Fu Rong Road, Hefei, Anhui, 230601, People's Republic of China
| | - Juehua Jing
- Department of Orthopaedics, The Second Affiliated Hospital of Anhui Medical University, 678#Fu Rong Road, Hefei, Anhui, 230601, People's Republic of China.
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Wang T, Wang CJ, Tian S, Song HB. Overexpressed IGFBP5 promotes cell proliferation and inhibits apoptosis of nucleus pulposus derived from rats with disc degeneration through inactivating the ERK/MAPK axis. J Cell Biochem 2019; 120:18782-18792. [PMID: 31310371 DOI: 10.1002/jcb.29191] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 05/29/2019] [Indexed: 12/19/2022]
Abstract
It is previously suggested that insulin-like growth factor binding proteins (IGFBPs) potentially share an association with disc degeneration (DD) that causes back pain. This study aimed at exploring the functional relevance of IGFBP5 in DD by establishing a rat model of DD. The nucleus pulposus (NP) cells were transduced with IGFBP5-shRNA or IGFBP5 overexpression to determine the cellular processes (proliferation, apoptosis, as well as colony formation). The protein levels of apoptosis-related proteins were evaluated. Furthermore, NP cells were treated with the extracellular signal-regulated kinases/mitogen-activated protein kinase (ERK/MAPK) pathway inhibitor (PD98059) followed by measurement of ERK protein level and ERK phosphorylation content. The NP cells showed suppressed proliferation and colony formation ability, yet promoted apoptosis after transfection with IGFBP5-shRNA. It was found that silencing of IGFBP5 could lead to the ERK/MAPK axis activation, as indicated by an elevated ERK protein level and ERK phosphorylation content. However, overexpression of IGFBP5 could reverse all the reaction induced by silenced IGFBP5. These key findings demonstrate that overexpressed IGFBP5 inactivates the ERK/MAPK axis to stimulate the proliferation and inhibit apoptosis of NP cells in a rat model of DD.
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Affiliation(s)
- Tao Wang
- Department of Spine Surgery, Dongying People's Hospital, Dongying, Shandong, P.R. China
| | - Chun-Ju Wang
- Department of Spine Surgery, Dongying People's Hospital, Dongying, Shandong, P.R. China
| | - Shuang Tian
- Department of Spine Surgery, Dongying People's Hospital, Dongying, Shandong, P.R. China
| | - Hai-Bo Song
- Department of Spine Surgery, Dongying People's Hospital, Dongying, Shandong, P.R. China
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Hu BW, Lv X, Chen SF, Shao ZW. Application of Finite Element Analysis for Investigation of Intervertebral Disc Degeneration: from Laboratory to Clinic. Curr Med Sci 2019; 39:7-15. [PMID: 30868485 DOI: 10.1007/s11596-019-1993-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 09/06/2018] [Indexed: 01/06/2023]
Abstract
Due to the ethical concern and inability to detect inner stress distributions of intervertebral disc (IVD), traditional methods for investigation of intervertebral disc degeneration (IVDD) have significant limitations. Many researchers have demonstrated that finite element analysis (FEA) is an effective tool for the research of IVDD. However, the specific application of FEA for investigation of IVDD has not been systematically elucidated before. In the present review, we summarize the current finite element models (FEM) used for the investigation of IVDD, including the poroelastic nonlinear FEM, diffusive-reactive theory model and cell-activity coupled mechano-electrochemical theory model. We further elaborate the use of FEA for the research of IVDD pathogenesis especially for nutrition and biomechanics associated etiology, and the biological, biomechanical and clinical influences of IVDD. In addition, the application of FEA for evaluation and exploration of various treatments for IVDD is also elucidated. We conclude that FEA is an excellent technique for research of IVDD, which could be used to explore the etiology, biology and biomechanics of IVDD. In the future, FEA may help us to achieve the goal of individualized precision therapy.
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Affiliation(s)
- Bin-Wu Hu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Xiao Lv
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Song-Feng Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Zeng-Wu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Travascio F, Jackson AR. The nutrition of the human meniscus: A computational analysis investigating the effect of vascular recession on tissue homeostasis. J Biomech 2017; 61:151-159. [PMID: 28778387 DOI: 10.1016/j.jbiomech.2017.07.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/09/2017] [Accepted: 07/16/2017] [Indexed: 11/19/2022]
Abstract
The meniscus is essential to the functioning of the knee, offering load support, congruency, lubrication, and protection to the underlying cartilage. Meniscus degeneration affects ∼35% of the population, and potentially leads to knee osteoarthritis. The etiology of meniscal degeneration remains to be elucidated, although many factors have been considered. However, the role of nutritional supply to meniscus cells in the pathogenesis of meniscus degeneration has been so far overlooked. Nutrients are delivered to meniscal cells through the surrounding synovial fluid and the blood vessels present in the outer region of the meniscus. During maturation, vascularization progressively recedes up to the outer 10% of the tissue, leaving the majority avascular. It has been hypothesized that vascular recession might significantly reduce the nutrient supply to cells, thus contributing to meniscus degeneration. The objective of this study was to evaluate the effect of vascular recession on nutrient levels available to meniscus cells. This was done by developing a novel computational model for meniscus homeostasis based on mixture theory. It was found that transvascular transport of nutrients in the vascularized region of the meniscus contributes to more than 40% of the glucose content in the core of the tissue. However, vascular recession does not significantly alter nutrient levels in the meniscus, reducing at most 5% of the nutrient content in the central portion of the tissue. Therefore, our analysis suggests that reduced vascularity is not likely a primary initiating source in tissue degeneration. However, it does feasibly play a key role in inability for self-repair, as seen clinically.
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Affiliation(s)
- Francesco Travascio
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, United States.
| | - Alicia R Jackson
- Orthopaedic Biomechanics Laboratory, Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
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Ouyang ZH, Wang WJ, Yan YG, Wang B, Lv GH. The PI3K/Akt pathway: a critical player in intervertebral disc degeneration. Oncotarget 2017; 8:57870-57881. [PMID: 28915718 PMCID: PMC5593690 DOI: 10.18632/oncotarget.18628] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/10/2017] [Indexed: 12/16/2022] Open
Abstract
Intervertebral disc degeneration (IDD) is thought to be the primary cause of low back pain, a severe public health problem worldwide. Current therapy for IDD aims to alleviate the symptoms and does not target the underlying pathological alternations within the disc. Activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway protects against IDD, which is attributed to increase of ECM content, prevention of cell apoptosis, facilitation of cell proliferation, induction or prevention of cell autophagy, alleviation of oxidative damage, and adaptation of hypoxic microenvironment. In the current review, we summarize recent progression on activation and negative regulation of the PI3K/Akt signaling pathway, and highlight its impact on IDD. Targeting this pathway could become an attractive therapeutic strategy for IDD in the near future.
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Affiliation(s)
- Zhi-Hua Ouyang
- Department of Spine Surgery, The 2nd Xiangya Hospital of Central South University, Changsha, China.,Department of Spine Surgery, The First Affiliated Hospital, University of South China, Hengyang, China
| | - Wen-Jun Wang
- Department of Spine Surgery, The First Affiliated Hospital, University of South China, Hengyang, China
| | - Yi-Guo Yan
- Department of Spine Surgery, The First Affiliated Hospital, University of South China, Hengyang, China
| | - Bing Wang
- Department of Spine Surgery, The 2nd Xiangya Hospital of Central South University, Changsha, China
| | - Guo-Hua Lv
- Department of Spine Surgery, The 2nd Xiangya Hospital of Central South University, Changsha, China
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Elmasry S, Asfour S, de Rivero Vaccari JP, Travascio F. A computational model for investigating the effects of changes in bioavailability of insulin-like growth factor-1 on the homeostasis of the intervertebral disc. Comput Biol Med 2016; 78:126-137. [PMID: 27697672 DOI: 10.1016/j.compbiomed.2016.09.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/08/2016] [Accepted: 09/21/2016] [Indexed: 01/04/2023]
Abstract
Insulin-like growth factor-1 (IGF-1) is well-known for upregulating cell proliferation and biosynthesis of the extracellular matrix in the intervertebral disc (IVD). Pathological conditions, such as obesity or chronic kidney disease cause IGF-1 deficiency in plasma. How this deficiency impacts disc homeostasis remains unknown. Pro-anabolic approaches for the treatment of disc degeneration based on enhancing IGF-1 bioavailability to tissue-cells are considered, but knowledge of their effectiveness in enhancing cellular anabolism of a degenerated disc is limited. In this study, we developed a computational model for disc homeostasis specifically addressing the role of IGF-1 in modulating both extracellular matrix biosynthesis and cellularity in the IVD. This model was applied to investigate how changes in IGF-1 bioavailability, namely deficiency or enhancement of growth factor, affect disc health. In this study, it was found that IGF-1 deficiency mainly affects the biosynthesis of ECM components, especially in the most external regions of the IVD such as the cartilage endplates and the outer portion of annulus fibrosus. Also, a total of three approaches for increasing IGF-1 bioavailability as a therapy for degenerated IVDs were investigated. It was found that all these strategies are only beneficial to those disc regions receiving sufficient nutritional supply (i.e., the outmost IVD regions), while they exacerbate tissue degradation in malnourished regions (i.e., inner portion of the disc). This suggests that pro-anabolic growth factor-based therapies are limited in that their success strongly depends on an adequate nutritional supply to the IVD tissue, which is not guaranteed in degenerated discs.
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Affiliation(s)
- Shady Elmasry
- Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA
| | - Shihab Asfour
- Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA
| | | | - Francesco Travascio
- Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA.
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Coupling cellular phenotype and mechanics to understand extracellular matrix formation and homeostasis in osteoarthritis * *financial support through BMBF project OVERLOAD-PrevOp, grant number 01EC1408H is acknowledged. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.ifacol.2016.12.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Effects of Tobacco Smoking on the Degeneration of the Intervertebral Disc: A Finite Element Study. PLoS One 2015; 10:e0136137. [PMID: 26301590 PMCID: PMC4547737 DOI: 10.1371/journal.pone.0136137] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/31/2015] [Indexed: 12/31/2022] Open
Abstract
Tobacco smoking is associated with numerous pathological conditions. Compelling experimental evidence associates smoking to the degeneration of the intervertebral disc (IVD). In particular, it has been shown that nicotine down-regulates both the proliferation rate and glycosaminoglycan (GAG) biosynthesis of disc cells. Moreover, tobacco smoking causes the constriction of the vascular network surrounding the IVD, thus reducing the exchange of nutrients and anabolic agents from the blood vessels to the disc. It has been hypothesized that both nicotine presence in the IVD and the reduced solute exchange are responsible for the degeneration of the disc due to tobacco smoking, but their effects on tissue homeostasis have never been quantified. In this study, a previously presented computational model describing the homeostasis of the IVD was deployed to investigate the effects of impaired solute supply and nicotine-mediated down-regulation of cell proliferation and biosynthetic activity on the health of the disc. We found that the nicotine-mediated down-regulation of cell anabolism mostly affected the GAG concentration at the cartilage endplate, reducing it up to 65% of the value attained in normal physiological conditions. In contrast, the reduction of solutes exchange between blood vessels and disc tissue mostly affected the nucleus pulposus, whose cell density and GAG levels were reduced up to 50% of their normal physiological levels. The effectiveness of quitting smoking on the regeneration of a degenerated IVD was also investigated, and showed to have limited benefit on the health of the disc. A cell-based therapy in conjunction with smoke cessation provided significant improvements in disc health, suggesting that, besides quitting smoking, additional treatments should be implemented in the attempt to recover the health of an IVD degenerated by tobacco smoking.
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