Publications by authors named "Simon K Chow"

Patient-specific induced pluripotent stem cells (iPSCs)-based modeling potentially recapitulates the pathology and mechanisms more faithfully than cell line models and general animal models. Utilizing iPSC-derived cells for personalized bone formation research offers a powerful tool to better understand the role of individual differences in bone health and disease and provide more precise information for personalized bone regeneration therapies. Here we generated iPSC-derived mesenchymal progenitor cells (iMPCs), endothelial cells (iECs), and macrophages (iMØ), from different donors.

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Background: Corticosteroids provide well-established therapeutic benefits; however, they are also accompanied by adverse effects on bone. Metformin is a widely used medication for managing type 2 diabetes mellitus. Recent studies have highlighted additional therapeutic benefits of metformin, particularly concerning bone health and oxidative stress.

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Histomorphometry is an important technique in the evaluation of non-traumatic osteonecrosis of the femoral head (ONFH). Quantification of empty lacunae and pyknotic cells on histological images is the most reliable measure of ONFH pathology, yet it is time and manpower consuming. This study focused on the application of artificial intelligence (AI) technology to tissue image evaluation.

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Article Synopsis
  • The study highlights the crucial need for early detection of osteonecrosis of the femoral head (ONFH) in young patients undergoing long-term glucocorticoid therapy, using AI to enhance radiographic assessments.
  • Traditional imaging methods like X-rays and MRIs are vital but may be costly and time-consuming, prompting a focus on using AI for better detection efficiency.
  • Results showed high accuracy in ONFH detection using AI models, with potential applications for utilizing synthetic MRI generated from X-rays, although some quality limitations were noted in the synthetic images.
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Osteosarcopenia is a prevalent geriatric disease with a significantly increased risk of adverse outcomes than osteoporosis or sarcopenia alone. Identification of older adults with osteosarcopenia using High-Resolution Peripheral Quantitative Computed Tomography (HR-pQCT) could allow better clinical decision making. This study aimed to explore the feasibility of HR-pQCT to differentiate osteoporosis, sarcopenia, and osteosarcopenia in older adults, with a primary outcome to derive a model to distinguish older adults with osteosarcopenia from those with low bone mineral density only, and to examine important HR-pQCT parameters associated with osteosarcopenia.

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  • This review discusses various progenitor cell types and strategies for improving healing in complex bone fractures and defects, focusing on stem cell differentiation and therapy effectiveness.
  • It highlights how mesenchymal stem cells are vital for bone formation by turning into key cells like osteoblasts and how hematopoietic stem cells help modulate inflammation and repair.
  • The review also evaluates controversial therapies involving embryonic and induced pluripotent stem cells alongside minimally manipulative approaches like bone marrow aspirate concentrate (BMAC) and exosomes that aid in bone regeneration through intercellular communication and biological signals.
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Bone regeneration and repair are crucial to ambulation and quality of life. Factors such as poor general health, serious medical comorbidities, chronic inflammation, and ageing can lead to delayed healing and nonunion of fractures, and persistent bone defects. Bioengineering strategies to heal bone often involve grafting of autologous bone marrow aspirate concentrate (BMAC) or mesenchymal stem cells (MSCs) with biocompatible scaffolds.

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Sarcopenia is a complex age-associated syndrome of progressive loss of muscle mass and strength. Although this condition is influenced by many factors, age-related changes in immune function including immune cell dynamics, and chronic inflammation contribute to its progression. The complex interplay between the immune system, gut-muscle axis, and autophagy further underscores their important roles in sarcopenia pathogenesis.

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Approximately 5%-10% of fractures go on to delayed healing and nonunion, posing significant clinical, economic, and social challenges. Current treatment methods involving open bone harvesting and grafting are associated with considerable pain and potential morbidity at the donor site. Hence, there is growing interest in minimally invasive approaches such as bone marrow aspirate concentrate (BMAC), which contains mesenchymal stromal cells (MSCs), macrophages (Mφ), and T cells.

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The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies.

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Neuromuscular junction (NMJ) degeneration is one of pathological factors of sarcopenia. Low-magnitude high-frequency vibration (LMHFV) was reported effective in alleviating the sarcopenia progress. However, no previous study has investigated treatment effects of LMHFV targeting NMJ degeneration in sarcopenia.

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Joint replacement is a common surgery and is predominantly utilized for treatment of osteoarthritis in the aging population. The longevity of many of these implants depends on bony ingrowth. Here, we provide an overview of current techniques in osteogenesis (inducing bone growth onto an implant), which is affected by aging and inflammation.

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Article Synopsis
  • * Combining core decompression with cell-based therapy, particularly using autologous bone marrow concentrate, has shown better outcomes in preserving the femoral head compared to conventional methods.
  • * Researchers are exploring the use of genetically modified mesenchymal stem cells and osteoconductive scaffolds to enhance bone repair in ONFH, with animal studies showing promise for improved healing.
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  • The study investigates the role of the transcription factor NF-κB in chronic inflammation, particularly focusing on sex differences in response to treatment using NF-κB decoy oligodeoxynucleotides (ODN) in mice.
  • The research utilized a model of chronic inflammation and assessed various bone characteristics using advanced imaging and laboratory techniques, including in vitro differentiation studies.
  • Findings revealed that NF-κB decoy ODN promoted bone formation in male mice but not in females, while reducing bone resorption in both sexes, suggesting NF-κB as a potential therapeutic target, notably for males.
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Local cell therapy has recently gained attention for the treatment of joint diseases and fractures. Mesenchymal stem cells (MSCs) are not only involved in osteogenesis and angiogenesis, but they also have immunomodulatory functions, such as inducing macrophage migration during bone regeneration via macrophage crosstalk. C-C motif chemokine ligand 2 (CCL2), a known inflammatory mediator, is associated with the migration of macrophages during inflammation.

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  • Dysregulated inflammation contributes to various skeletal diseases, impairing bone formation, and is linked to mitochondrial dysfunction and changes in cell metabolism.
  • The study focuses on the effects of polyethylene particles contaminated with lipopolysaccharide (cPE) on macrophages and mesenchymal stromal cells, examining bioenergetics through advanced cellular assays.
  • Findings revealed that exposure to cPE leads to a significant decline in oxidative phosphorylation in macrophages, suggesting altered metabolic processes during inflammation.
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Background: Sarcopenia is the accelerated loss of muscle mass, strength and function. Mitochondrial dysfunction was related to the progression of sarcopenia; meanwhile, microRNAs were regarded as core roles in regulating mitochondrial function. Physical exercise is a well-accepted approach to attenuate sarcopenia, yet very few studies depict the molecular mechanisms.

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Novel minimally invasive strategies are needed to obtain robust bone healing in complex fractures and bone defects in the elderly population. Local cell therapy is one potential option for future treatment. Mesenchymal stromal cells (MSCs) are not only involved in osteogenesis but also help direct the recruitment of macrophages during bone regeneration via MSC-macrophage crosstalk.

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Article Synopsis
  • The aging global population is leading to a rise in osteoporosis and related fractures, which negatively affects quality of life and increases healthcare costs.
  • Chronic low-level inflammation (inflammaging) in the elderly hinders effective bone healing by disrupting the normal activation and repolarization of macrophages, which are crucial for bone regeneration.
  • Strategies like using mesenchymal stem cells (MSCs) and anti-inflammatory cytokines aim to improve bone healing by mitigating the effects of inflammaging and enhancing the body’s natural regenerative processes.
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Musculoskeletal ageing is a major health challenge as muscles and bones constitute around 55-60% of body weight. Ageing muscles will result in sarcopenia that is characterized by progressive and generalized loss of skeletal muscle mass and strength with a risk of adverse outcomes. In recent years, a few consensus panels provide new definitions for sarcopenia.

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Background: Elderly people with low lean and high fat mass, are diagnosed with sarcopenic obesity (SO), and often have poor clinical outcomes. This study aimed to explore the relationship between obesity and sarcopenia, and the optimal proportion of fat and muscle for old individuals.

Methods: Participants aged 60 years or above were instructed to perform bioelectrical impedance analysis to obtain the muscle and fat indicators, and handgrip strength was also performed.

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Objectives: The aim of this study was to discover the role of fat and muscle in bone structures, as well as the relationship between obesity and sarcopenia on age-related osteoporosis.

Methods: A total of 400 participants (65.0 ± 8.

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Aging and obesity are two global concerns in public health. Sarcopenic obesity (SO), defined as the combination of age-related sarcopenia and obesity, has become a pressing issue. This systematic review and meta-analysis summarize the current clinical evidence relevant to SO.

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Sarcopenia is an age-related geriatric syndrome characterized by the gradual loss of muscle mass and function. Low-magnitude high-frequency vibration (LMHFV) was shown to be beneficial to structural and functional outcomes of skeletal muscles, while magnesium (Mg) is a cofactor associated with better indices of skeletal muscle mass and strength. We hypothesized that LMHFV, Mg and their combinations could suppress inflammation and sarcopenic atrophy, promote myogenesis via PI3k/Akt/mTOR pathway in senescence-accelerated mouse P8 (SAMP8) mice and C2C12 myoblasts.

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