Publications by authors named "Yoshiaki Toyama"

To prevent infections associated with medical implants, various antimicrobial silver-coated implant materials have been developed. However, these materials do not always provide consistent antibacterial effects in vivo despite having dramatic antibacterial effects in vitro, probably because the antibacterial effects involve silver-ion-mediated reactive oxygen species generation. Additionally, the silver application process often requires extremely high temperatures, which damage non-metal implant materials.

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Background: Peripheral triangular fibrocartilage complex (TFCC) tears may induce instability of the distal radioulnar joint (DRUJ). In this biomechanical study, simulated peripheral tears of the TFCC were examined on the stability of the DRUJ. Restabilization effect of the DRUJ by ulnar shortening and direct repair of those injuries were sequentially examined.

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We treated an extremely rare case of osteoid osteoma of the pisiform. Pisiform hypertrophy caused persistent pain and ulnar nerve irritation at Guyon's canal after the initial trauma. The re-enlargement of the pisiform attracted our attention allowing us to ultimately diagnose the condition as osteoid osteoma and treat the patient with a successful clinical result.

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The diaphragm is driven by phrenic motoneurons that are located in the cervical spinal cord. Although the anatomical location of the phrenic nucleus and the function of phrenic motoneurons at a single cellular level have been extensively analyzed, the spatiotemporal dynamics of phrenic motoneuron group activity have not been fully elucidated. In the present study, we analyzed the functional and structural characteristics of respiratory neuron population in the cervical spinal cord at the level of the phrenic nucleus by voltage imaging, together with histological analysis of neuronal and astrocytic distribution in the cervical spinal cord.

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Hyaluronan (HA)-binding protein involved in HA depolymerization (HYBID), also called cell migration-inducing protein (CEMIP; alias KIAA1199), plays a key role in the degradation of HA in skin and arthritic synovial fibroblasts, but its functions in osteoarthritic (OA) cartilage remain elusive. Here, we investigated the expression and roles of HYBID in human OA cartilage. HYBID was highly expressed by chondrocytes in the HA-depleted area of OA cartilage, and HYBID immunoreactivity was correlated with Mankin score, the histopathologic severity of OA lesions of cartilage.

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Progress in regenerative medicine is realizing the possibility of neural regeneration and functional recovery in spinal cord injury (SCI). Recently, rehabilitation has attracted much attention with respect to the synergistic promotion of functional recovery in combination with neural stem/progenitor cell (NS/PC) transplantation, even in the chronic refractory phase of SCI. Nevertheless, sensory disturbance is one of the most prominent sequelae, even though the effects of combination or single therapies have been investigated mostly in the context of motor recovery.

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OBJECTIVE Chemonucleolysis with condoliase has the potential to be a new, less invasive therapeutic option for patients with lumbar disc herniation (LDH). The aim of the present study was to determine the most suitable therapeutic dose of condoliase. METHODS Patients between 20 and 70 years of age with unilateral leg pain, positive findings on the straight leg raise test, and LDH were recruited.

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Study Design: A randomized, double-blind, placebo-controlled, multicenter phase III clinical trial.

Objective: To evaluate the efficacy and safety of chemonucleolysis with condoliase in patients with lumbar disc herniation (LDH).

Summary Of Background Data: Condoliase is a pure mucopolysaccharidase derived from a bacterium, Proteus vulgaris that has high substrate specificity for chondroitin sulfate and hyaluronic acid in the nucleus pulposus of the intervertebral disc.

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Control of phosphate metabolism is crucial to regulate aging in mammals. Klotho is a well-known anti-aging factor that regulates phosphate metabolism: mice mutant or deficient in Klotho exhibit phenotypes resembling human aging. Here we show that ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1) is required for Klotho expression under phosphate overload conditions.

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Solitary metastasis of a carcinoma to carpal bone is extremely rare. Metastases of renal cell carcinoma (RCC) usually occur in a multiple fashion and there has been no report to date of a solitary metastasis to trapezium from RCC. The tumor was excised and reconstructed with iliac bone transplantation.

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Study Design: A prospective observational study.

Objective: To evaluate whether scoliosis is a risk factor for gastroesophageal reflux disease (GERD) in elderly patients.

Summary Of Background Data: Sagittal spinal deformities are reported to cause GERD, but its association with spinal deformity in the coronal plane is not well studied.

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Hip fracture is the most severe bone fragility fracture among osteoporotic injuries. Family history is a known risk factor for fracture and now included among criteria for osteoporosis diagnosis and treatment; however, genetic factors underlying family history favoring fracture remain to be elucidated. Here we demonstrate that a missense SNP in the ALDH2 gene, rs671 (ALDH2*2), is significantly associated with hip fracture (odds ratio = 2.

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Although human induced pluripotent stem cell (hiPSC) derivatives are considered promising cellular resources for regenerative medicine, their tumorigenicity potentially limits their clinical application in hiPSC technologies. We previously demonstrated that oncogenic hiPSC-derived neural stem/progenitor cells (hiPSC-NS/PCs) produced tumor-like tissues that were distinct from teratomas. To gain insight into the mechanisms underlying the regulation of tumorigenicity in hiPSC-NS/PCs, we performed an integrated analysis using the Infinium HumanMethylation450 BeadChip array and the HumanHT-12 v4.

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To achieve the goal of a first-in-human trial for human induced pluripotent stem cell (hiPSC)-based transplantation for the treatment of various diseases, allogeneic human leukocyte antigen (HLA)-matched hiPSC cell banks represent a realistic tool from the perspective of quality control and cost performance. Furthermore, considering the limited therapeutic time-window for acute injuries, including neurotraumatic injuries, an iPS cell bank is of potential interest. However, due to the relatively immunoprivileged environment of the central nervous system, it is unclear whether HLA matching is required in hiPSC-derived neural stem/progenitor cell (hiPSC-NS/PC) transplantation for the treatment of neurodegenerative diseases and neurotraumatic injuries.

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Osteoporosis is characterized as a metabolic disorder of bone tissue, and various metabolic markers are now available to support its diagnosis and evaluate treatment effects. Substances produced as end products of metabolomic activities are the correlated factors to the biological or metabolic status, and thus, metabolites are considered highly sensitive markers of particular pathological states, including osteoporosis. Here we undertook comprehensive serum metabolomics analysis in postmenopausal women with or without low bone mineral density (low BMD vs controls) for the first time using capillary electrophoresis/mass spectrometry.

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Anti-bone resorptive drugs such as bisphosphonates, the anti-RANKL antibody (denosumab), or selective estrogen receptor modulators (SERMs) have been developed to treat osteoporosis. Mechanisms underlying activity of bisphosphonates or denosumab in this context are understood, while it is less clear how SERMs like tamoxifen, raloxifene, or bazedoxifene inhibit bone resorption. Recently, accumulation of hypoxia inducible factor 1 alpha (Hif1α) in osteoclasts was shown to be suppressed by estrogen in normal cells.

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Bone homeostasis is maintained as a delicate balance between bone-resorption and bone-formation, which are coupled to maintain appropriate bone mass. A critical question is how bone-resorption is terminated to allow bone-formation to occur. Here, we show that TGFβs inhibit osteoclastogenesis and maintain bone-mass through Smad4 activity in osteoclasts.

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Whether Propionibacterium acnes (P. acnes) causes surgical-site infections (SSI) after orthopedic surgery is controversial. We previously reported that we frequently find P.

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Most studies targeting chronic spinal cord injury (SCI) have concluded that neural stem/progenitor cell (NS/PC) transplantation exerts only a subclinical recovery; this in contrast to its remarkable effect on acute and subacute SCI. To determine whether the addition of rehabilitative intervention enhances the effect of NS/PC transplantation for chronic SCI, we used thoracic SCI mouse models to compare manifestations secondary to both transplantation and treadmill training, and the two therapies combined, with a control group. Significant locomotor recovery in comparison with the control group was only achieved in the combined therapy group.

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Background: Distinguishing recipient cells from donor ligament cells is difficult in the early graft-healing phase after anterior cruciate ligament (ACL) reconstruction. The ability to track the distribution and differentiation of recipient cells using genetically engineered transgenic (Tg) animals would have significant clinical and research effects on graft healing after ACL reconstruction.

Hypothesis: Kusabira-Orange Tg pigs may allow the tracking of recipient cells infiltrating the graft after ACL reconstruction.

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Intervertebral disc degeneration proceeds with age and is one of the major causes of lumbar pain and degenerative lumbar spine diseases. However, studies in the field of intervertebral disc biology have been hampered by the lack of reliable cell lines that can be used for in vitro assays. In this study, we show that a chordoma-derived cell line U-CH1-N cells highly express the nucleus pulposus (NP) marker genes, including T (encodes T brachyury transcription factor), KRT19, and CD24.

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