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result(s) for
"Sawamura, Kenta"
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Disease-specific complications and multidisciplinary interventions in achondroplasia
by
Kamiya Yasunari
,
Sawamura Kenta
,
Mishima Kenichi
in
Achondroplasia
,
Activities of daily living
,
Airway management
2022
Achondroplasia (ACH) is the most common skeletal dysplasia and characterized by a disproportionate short stature, macrocephaly with frontal bossing, exaggerated lumbar lordosis, and trident hands. It is induced by activated mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. In addition to short stature, patients with ACH have a high prevalence of medical complications, including upper airway obstructive apnea, increased mortality, foramen magnum stenosis, hydrocephalus, developmental delay, recurrent ear infections, genu varum, obesity, and spinal canal stenosis, throughout their whole life. Several investigational drugs that modulate abnormal FGFR3 signaling have recently emerged, vosoritide being the most developed. This review presents the different disease-specific complications of ACH occurring in neonates, infants, childhood, adolescent, and adults and reports the current multidisciplinary interventions for these various complications. Moreover, we propose treatment strategies for children with ACH from the perspective of quality of life in adulthood.
Journal Article
Quantum annealing-based route optimization for commercial AGV operating systems in large-scale logistics warehouses
2025
This study proposes a new approach to optimizing the routing of Automated Guided Vehicles (AGVs) in large-scale logistics warehouses using Quantum Annealing. As logistics operations grow, efficient AGV routing becomes critical for ensuring safety, reliability, and throughput, particularly in high-density environments. To address the complexity of real-world systems, we introduce an enhanced cost function that incorporates a real-time priority factor to improve both routing performance and operation safety. In this paper, we present a secure and computationally efficient candidate route generation method, along with an Optimization Problem Clustering technique that decomposes the large problem into smaller, tractable subproblems to reduce computational complexity. The proposed methods are designed to incorporate real-time operational data to ensure collision avoidance, maintain safe operations, and enhance routing efficiency in realistic large-scale warehouse environments. We validate the proposed methods using a state-of-the-art Quantum Annealing machine, benchmarking against both classical and quantum-inspired solvers. Integration with a commercial AGV Operating System (AOS) is demonstrated, enabling seamless connectivity with classical solvers via a local network and with Quantum Annealing and Quantum-inspired solvers via cloud infrastructure. Simulations involving 1000 AGVs show that the proposed route generation method reduces the number of optimization variables by an average of 96% for small-scale to medium-scale systems and 78% for large-scale systems, while also improving route quality. The clustering method reduces the maximum problem size to under 10,000 variables, enabling scalable and safe control of large AGV fleets. Furthermore, a complexity-based problem formulation reduces sampling time by approximately 28.2% compared to conventional size-based approaches for problems ranging from 1000 to 10,000 variables. These results demonstrate the practical viability of Quantum Annealing for managing large-scale AGV Operating Systems and underscore the potential of the proposed methods for advancing logistics optimization in real-world warehouse environments.
Journal Article
Gradual Reduction Using Overhead Traction for Late-Detected Developmental Dysplasia of the Hip: A Report of Three Cases Diagnosed Among Children Over Four Years Old
2024
Optimal reduction methods for late-detected developmental dysplasia of the hip (DDH) remain debatable. Gradual reduction (GR) using traction is a safer and more reliable option for late-detected DDH than closed reduction or open reduction with or without preliminary traction. GR using overhead traction, one of the current GR methods, has been indicated for children of walking age up to four years of age, whereas the upper age limit of this method has not yet been determined. We present three cases of late-detected DDH whose hips were treated between four and six years of age with this method. Stable reduction without subsequent redislocation was technically accomplished for all patients, albeit the duration of horizontal traction became longer than usual. Clinically significant avascular necrosis (AVN) has developed in children aged ≥5 years, indicating the need for some modifications to the conventional protocol to prevent AVN.
Journal Article
Pulse-Driven Magnetoimpedance Sensor Detection of Cardiac Magnetic Activity
by
Sawamura, Kenta
,
Uchiyama, Tsuyoshi
,
Nakayama, Shinsuke
in
Adult
,
Biology
,
Biosensing Techniques - methods
2011
This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI) sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT) level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG). The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.
Journal Article
Serotonin Augments Gut Pacemaker Activity via 5-HT3 Receptors
2011
Serotonin (5-hydroxytryptamine: 5-HT) affects numerous functions in the gut, such as secretion, muscle contraction, and enteric nervous activity, and therefore to clarify details of 5-HT's actions leads to good therapeutic strategies for gut functional disorders. The role of interstitial cells of Cajal (ICC), as pacemaker cells, has been recognised relatively recently. We thus investigated 5-HT actions on ICC pacemaker activity. Muscle preparations with myenteric plexus were isolated from the murine ileum. Spatio-temporal measurements of intracellular Ca(2+) and electric activities in ICC were performed by employing fluorescent Ca(2+) imaging and microelectrode array (MEA) systems, respectively. Dihydropyridine (DHP) Ca(2+) antagonists and tetrodotoxin (TTX) were applied to suppress smooth muscle and nerve activities, respectively. 5-HT significantly enhanced spontaneous Ca(2+) oscillations that are considered to underlie electric pacemaker activity in ICC. LY-278584, a 5-HT(3) receptor antagonist suppressed spontaneous Ca(2+) activity in ICC, while 2-methylserotonin (2-Me-5-HT), a 5-HT(3) receptor agonist, restored it. GR113808, a selective antagonist for 5-HT(4), and O-methyl-5-HT (O-Me-5-HT), a non-selective 5-HT receptor agonist lacking affinity for 5-HT(3) receptors, had little effect on ICC Ca(2+) activity. In MEA measurements of ICC electric activity, 5-HT and 2-Me-5-HT caused excitatory effects. RT-PCR and immunostaining confirmed expression of 5-HT(3) receptors in ICC. The results indicate that 5-HT augments ICC pacemaker activity via 5-HT(3) receptors. ICC appear to be a promising target for treatment of functional motility disorders of the gut, for example, irritable bowel syndrome.
Journal Article
Spatial Analysis of Slowly Oscillating Electric Activity in the Gut of Mice Using Low Impedance Arrayed Microelectrodes
2013
Smooth and elaborate gut motility is based on cellular cooperation, including smooth muscle, enteric neurons and special interstitial cells acting as pacemaker cells. Therefore, spatial characterization of electric activity in tissues containing these electric excitable cells is required for a precise understanding of gut motility. Furthermore, tools to evaluate spatial electric activity in a small area would be useful for the investigation of model animals. We thus employed a microelectrode array (MEA) system to simultaneously measure a set of 8×8 field potentials in a square area of ∼1 mm(2). The size of each recording electrode was 50×50 µm(2), however the surface area was increased by fixing platinum black particles. The impedance of microelectrode was sufficiently low to apply a high-pass filter of 0.1 Hz. Mapping of spectral power, and auto-correlation and cross-correlation parameters characterized the spatial properties of spontaneous electric activity in the ileum of wild-type (WT) and W/W(v) mice, the latter serving as a model of impaired network of pacemaking interstitial cells. Namely, electric activities measured varied in both size and cooperativity in W/W(v) mice, despite the small area. In the ileum of WT mice, procedures suppressing the excitability of smooth muscle and neurons altered the propagation of spontaneous electric activity, but had little change in the period of oscillations. In conclusion, MEA with low impedance electrodes enables to measure slowly oscillating electric activity, and is useful to evaluate both histological and functional changes in the spatio-temporal property of gut electric activity.
Journal Article
Phase 1b study on the repurposing of meclizine hydrochloride for children with achondroplasia
by
Kato, Daisaku
,
Sawamura, Kenta
,
Takemoto, Genta
in
Achondroplasia
,
Achondroplasia - genetics
,
Analysis
2023
Achondroplasia (ACH) is a common skeletal dysplasia characterized by a disproportionately short stature. We found that meclizine, which is an over-the-counter drug for motion sickness, inhibited the fibroblast growth factor receptor 3 (FGFR3) gene using a drug repositioning strategy, and meclizine 1 and 2 mg/kg/day promoted bone growth in a mouse model of ACH. A previous phase 1a clinical trial for children with ACH demonstrated that a single dose of meclizine 25 and 50 mg was safe and that the simulated plasma concentration achieved steady state approximately 10 days after the first dose. The current study aimed to evaluate the safety and pharmacokinetics (PK) of meclizine in children with ACH after a 14-day-repeated dose of meclizine. Twelve patients with ACH aged 5–10 years were enrolled. Meclizine 12.5 (cohort 1) and 25 mg/day (cohort 2) were administered after meals for 14 days, and adverse events (AEs) and PK were evaluated. No patient experienced serious AEs in either group. The average (95% confidential interval [CI]) maximum drug concentration (C max ), peak drug concentration (T max ), area under the curve (AUC) from 0 to 24 h, and terminal elimination half-life (t 1/2 ) after a 14-day-repeated administration of meclizine (12.5 mg) were 167 (83–250) ng/mL, 3.7 (3.1–4.2) h, 1170 (765–1570) ng·h/mL, and 7.4 (6.7–8.0) h, respectively. The AUC 0-6h after the final administration was 1.5 times that after the initial dose. C max and AUC were higher in cohort 2 than in cohort 1 in a dose-dependent manner. Regarding the regimen of meclizine 12.5 and 25 mg in patients < 20 kg and ≥ 20 kg, respectively, the average (95% CI) AUC 0-24h was 1270 (1100–1440) ng·h/mL. Compartment models demonstrated that the plasma concentration of meclizine achieved at a steady state after the 14th administration. Long-term administration of meclizine 12.5 or 25 mg/day is recommended for phase 2 clinical trials in children with ACH.
Journal Article
Collagen-binding C-type natriuretic peptide enhances chondrogenesis and osteogenesis
2025
C-type natriuretic peptide (CNP) is known to promote chondrocyte proliferation and bone formation; however, CNP's extremely short half-life necessitates continuous intravascular administration to achieve bone-lengthening effects. Vosoritide, a CNP analog designed for resistance to neutral endopeptidase, allows for once daily administration. Nonetheless, it distributes systemically rather than localizing to target tissues, which may result in adverse effects such as hypotension. To enhance local drug delivery and therapeutic efficacy, we developed a novel synthetic protein by fusing a collagen-binding domain (CBD) to CNP, termed CBD-CNP. This fusion protein exhibited stability under heat conditions and retained the collagen-binding ability and bioactivity as CNP. CBD-CNP localized to articular cartilage in fetal murine tibiae and promoted bone elongation. Spatial transcriptomic analysis revealed that the upregulation of chondromodulin expression may contribute to its therapeutic effects. Treatment of CBD-CNP mixed with collagen powder to a fracture site of a mouse model increased bone mineral content and bone volume rather than CNP-22. Intra-articular injection of CBD-CNP to a mouse model of knee osteoarthritis suppressed subchondral bone thickening. By addressing the limitations of CNP's rapid degeneration, CBD-CNP leverages its collagen-binding capacity to achieve targeted, sustained delivery in collagen-rich tissues, offering a promising strategy for enhancing chondrogenesis and osteogenesis.
Journal Article
Dynamic regulation of human endogenous retroviruses mediates factor-induced reprogramming and differentiation potential
by
Watanabe, Akira
,
Takahashi, Kazutoshi
,
Ohnuki, Mari
in
Biological Sciences
,
Biotechnologie
,
Biotechnology
2014
Pluripotency can be induced in somatic cells by overexpressing transcription factors, including POU class 5 homeobox 1 (OCT3/4), sex determining region Y-box 2 (SOX2), Krüppel-like factor 4 (KLF4), and myelocytomatosis oncogene (c-MYC). However, some induced pluripotent stem cells (iPSCs) exhibit defective differentiation and inappropriate maintenance of pluripotency features. Here we show that dynamic regulation of human endogenous retroviruses (HERVs) is important in the reprogramming process toward iPSCs, and in re-establishment of differentiation potential. During reprogramming, OCT3/4, SOX2, and KLF4 transiently hyperactivated LTR7s—the long-terminal repeats of HERV type-H (HERV-H)—to levels much higher than in embryonic stem cells by direct occupation of LTR7 sites genome-wide. Knocking down LTR7s or long intergenic non-protein coding RNA, regulator of reprogramming (lincRNA-RoR), a HERV-H–driven long noncoding RNA, early in reprogramming markedly reduced the efficiency of iPSC generation. KLF4 and LTR7 expression decreased to levels comparable with embryonic stem cells once reprogramming was complete, but failure to resuppress KLF4 and LTR7s resulted in defective differentiation. We also observed defective differentiation and LTR7 activation when iPSCs had forced expression of KLF4. However, when aberrantly expressed KLF4 or LTR7s were suppressed in defective iPSCs, normal differentiation was restored. Thus, a major mechanism by which OCT3/4, SOX2, and KLF4 promote human iPSC generation and reestablish potential for differentiation is by dynamically regulating HERV-H LTR7s.
Journal Article
A case of atypical teratoid/rhabdoid tumor in an adult, with long survival
by
Katoh, Masahito
,
Kanno, Hiromi
,
Nagashima, Kazuo
in
Adult
,
Adults
,
Biomarkers, Tumor - analysis
2011
Atypical teratoid/rhabdoid tumor (AT/RT) is a malignant tumor that mostly occurs in early childhood and has poor prognosis despite aggressive therapy. Adult cases are rare and, as far as we are aware, only 30 cases have been reported to date. Here we present the case of a 27-year-old female with left parietal AT/RT with the chief complaint of numbness of the right superior limb. First, the tumor was surgically removed and the diagnosis was grade II glioma. With additional radiotherapy, the clinical course after surgery was favorable. After 6 years, she had an operation for recurrence and the diagnosis was grade III glioma. Temozolomide was prescribed, and a disease-free period of 2 years followed. Surgery was performed for a third time for second recurrence with histology of diffuse growth of rhabdoid cells. Immunohistochemistry was partially positive for vimentin and epithelial membrane antigen. Ki-67 labeling index was extremely high and tumor cells showed no staining of INI1 suggestive of diagnosis of AT/RT. We re-evaluated past specimens and none had immunoreactivity of INI1. Ki-67 labeling index and O-6 methylguanine DNA methyltransferase (MGMT) staining were also re-examined and both increased gradually. She is still alive without recurrence for more than 1 year. As far as we are aware, this is the second longest survival of an adult with AT/RT.
Journal Article