Publications by authors named "Shinohara I"

Electromagnetic whistler-mode chorus waves are a key driver of variations in energetic electron fluxes in the Earth's magnetosphere through the wave-particle interaction. Traditionally understood as a diffusive process, these interactions account for long-term electron flux variations (> several minutes). However, theories suggest that chorus waves can also cause rapid (< 1 s) electron acceleration and significant flux variations within less than a second through a nonlinear wave-particle interaction.

View Article and Find Full Text PDF

Mesenchymal stem cells (MSCs) play an important role in regenerative medicine and drug discovery due to their multipotential differentiation capabilities and immunomodulatory effects. Compared with traditional 2D cultures of MSCs, 3D cultures of MSCs have emerged as an effective approach to enhance cell viability, proliferation, and functionality, and provide a more relevant physiological environment. Here, we review the therapeutic potential of 3D-cultured MSCs, highlighting their roles in tissue regeneration and repair and drug screening.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: The medial ulnar collateral ligament (UCL) of the elbow joint is the primary restraint to valgus stress during the throwing motion. The flexor pronator muscles (FPMs) also stabilize the elbow joint against valgus forces; however, assessment of FPM stiffness in baseball players has been limited.

Purpose: To use ultrasound shear wave elastography (USWE) to evaluate the change in tissue elasticity of the FPMs due to pitching.

View Article and Find Full Text PDF
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.
View Article and Find Full Text PDF

The thumb function is complex, and accurate evaluation through images or videos is difficult. Pose estimation, a technology that uses artificial intelligence (AI) to estimate skeletal detection of the body, is gaining popularity. In this study, we combined the pose estimation library MediaPipe-Hands and five machine learning (ML) models to predict the radial abduction angle of the thumb.

View Article and Find Full Text PDF
Article Synopsis
  • 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.
View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

The hazardous plasma environment surrounding Earth poses risks to satellites due to internal charging and surface charging effects. Accurate predictions of these risks are crucial for minimizing damage and preparing for system failures of satellites. To forecast the plasma environment, it is essential to know the current state of the system, as the accuracy of the forecast depends on the accuracy of the initial condition of the forecast.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: Advanced glycation end products (AGEs) are compounds formed due to aging and diabetes mellitus (DM). They activate NADPH oxidase (NOX) by binding to their receptors, thereby increasing the production of reactive oxygen species (ROS), which cause oxidative stress. In this study, we investigated the effects of AGEs on the tissues of the shoulder joint (such as rotator cuff synovium, and capsule) in patients with DM having rotator cuff tears.

View Article and Find Full Text PDF

Both solar wind and ionospheric sources contribute to the magnetotail plasma sheet, but how their contribution changes during a geomagnetic storm is an open question. The source is critical because the plasma sheet properties control the enhancement and decay rate of the ring current, the main cause of the geomagnetic field perturbations that define a geomagnetic storm. Here we use the solar wind composition to track the source and show that the plasma sheet source changes from predominantly solar wind to predominantly ionospheric as a storm develops.

View Article and Find Full Text PDF

Background: Postoperative rotator cuff retear after arthroscopic rotator cuff repair (ARCR) is still a major problem. Various risk factors such as age, gender, and tear size have been reported. Recently, magnetic resonance imaging-based stump classification was reported as an index of rotator cuff fragility.

View Article and Find Full Text PDF

Substantial advancements in markerless motion capture accuracy exist, but discrepancies persist when measuring joint angles compared to those taken with a goniometer. This study integrates machine learning techniques with markerless motion capture, with an aim to enhance this accuracy. Two artificial intelligence-based libraries-MediaPipe and LightGBM-were employed in executing markerless motion capture and shoulder abduction angle estimation.

View Article and Find Full Text PDF

Equatorial plasma bubbles are a phenomenon of plasma density depletion with small-scale density irregularities, normally observed in the equatorial ionosphere. This phenomenon, which impacts satellite-based communications, was observed in the Asia-Pacific region after the largest-on-record January 15, 2022 eruption of the Tonga volcano. We used satellite and ground-based ionospheric observations to demonstrate that an air pressure wave triggered by the Tonga volcanic eruption could cause the emergence of an equatorial plasma bubble.

View Article and Find Full Text PDF

Advanced glycation end-products (AGEs) play a critical supportive role during musculoskeletal disorders via glycosylation and oxidative stress. Though apocynin, identified as a potent and selective inhibitor of NADPH oxidase, has been reported to be involved in pathogen-induced reactive oxygen species (ROS), its role in age-related rotator cuff degeneration has not been well clarified. Therefore, this study aims to evaluate the in vitro effects of apocynin on human rotator cuff-derived cells.

View Article and Find Full Text PDF

The coracohumeral ligament (CHL) is related to the range of motion of the shoulder joint. The evaluation of the CHL using ultrasonography (US) has been reported on the elastic modulus and thickness of the CHL, but no dynamic evaluation method has been established. We aimed to quantify the movement of the CHL by applying Particle Image Velocimetry (PIV), a technique used in the field of fluid engineering, to cases of shoulder contracture using the US.

View Article and Find Full Text PDF

The diagnosis of osteoporosis is made by measuring bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). Machine learning, one of the artificial intelligence methods, was used to predict low BMD without using DXA in elderly women. Medical records from 2541 females who visited the osteoporosis clinic were used in this study.

View Article and Find Full Text PDF

Purpose: Arthroscopic repair is performed for fovea injuries of the triangular fibrocartilage complex (TFCC) when instability of the distal radioulnar joint results in pain, decreased grip strength, and mechanical symptoms. During TFCC repair, reconstruction of its attachment to the fovea is important. Nonabsorbent suture tapes have gained attention for ligament repair in the trapeziometacarpal joint, scapholunate ligament, and thumb metacarpophalangeal ligament.

View Article and Find Full Text PDF
Article Synopsis
  • - The study explored the effectiveness of using deep learning (DL) techniques on ultrasonography (US) images to diagnose osteochondritis dissecans (OCD) in young baseball players, aiming to improve prediction accuracy.
  • - A cohort of 40 elbows (average age 12.1 years) was analyzed, using a total of 4,000 images captured from US videos, where 80% were trained using DL models and the remaining 20% were for testing.
  • - Results showed the DL model achieved a commendable accuracy of 0.87, with a recall of 1.00, indicating a strong ability to identify OCD, particularly by recognizing surface irregularities in the bone.
View Article and Find Full Text PDF

Background: Injury to the ulnar collateral ligament (UCL) of the elbow can cause chronic pain and loss of throwing ability. Ultrasonic shear wave elastography (SWE) is a new imaging method that can be used for quantitative assessment of tissue elasticity.

Purpose: To evaluate the properties of the UCL in professional baseball players using SWE.

View Article and Find Full Text PDF

Purpose: One-stage arthroscopic rotator cuff repair with manipulation has been recently performed for rotator cuff tears with shoulder stiffness, whereas some patients require capsular release due to severe stiffness that is difficult to treat with manipulation. The purpose of this study was to analyze patient backgrounds and related factors of success or failure of manipulation alone for the treatment of shoulder stiffness associated with rotator cuff tears. Methods: This study included 64 patients with rotator cuff tears and shoulder stiffness who underwent arthroscopic rotator cuff repair with manipulation alone or with manipulation and capsular release of the glenohumeral joint at our institution between January 2015 and September 2019.

View Article and Find Full Text PDF