Publications by authors named "Hiroyuki Tsukazaki"

Article Synopsis
  • This study compared the effectiveness of two surgical procedures, anterior spinal fusion (ASF) and posterior cervical foraminotomy (PCF), in helping patients recover motor function after surgery for cervical spondylotic radiculopathy (CSR).
  • A total of 227 patients were evaluated, with 106 focusing specifically on those with upper-limb motor deficits, and their recovery was monitored for at least 12 months post-surgery.
  • Results indicated that while the overall recovery rates were similar (74% for ASF and 86% for PCF), the PCF group recovered motor function significantly faster at 3, 6, and 12 months compared to the ASF group, suggesting PCF may be the better option for quicker recovery
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  • This study investigates whether using titanium-coated polyetheretherketone (TP) cages can improve fusion rates in patients undergoing posterior lumbar interbody fusion (PLIF) with cortical bone trajectory (CBT) screw fixation compared to carbon fiber-reinforced cages (CP).
  • A total of 157 patients were analyzed, with 68 receiving TP cages and 89 receiving CP cages, and their fusion outcomes were assessed through imaging at 1 and 2 years after surgery.
  • Results showed no significant difference in fusion rates between the TP and CP groups over time; however, the CP group demonstrated a noteworthy increase in fusion rates from the first to the second year, while the TP group's rates peaked at
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The effects and inflammation-related side effects of bone morphogenetic protein (BMP)-2 on posterior lumbar interbody fusion are controversial. One of the potential causes for the inconsistent results is the uncontrolled release of BMP-2 from the collagen carrier. Therefore, BMP delivery systems that support effective bone regeneration while attenuating the side effects are strongly sought for.

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Bone morphogenetic proteins (BMPs) have been clinically applied for induction of bone formation in musculoskeletal disorders such as critical-sized bone defects, nonunions, and spinal fusion surgeries. However, the use of supraphysiological doses of BMP caused adverse events, which were sometimes life-threatening. Therefore, safer treatment strategies for bone regeneration have been sought for decades.

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Article Synopsis
  • Bone metabolism involves a balance between osteoblasts (which build bone) and osteoclasts (which break it down), but the switch between these processes isn't fully understood.
  • Researchers discovered that a specific type of vesicle from mature osteoblasts can inhibit bone formation and promote the formation of osteoclasts.
  • These vesicles, called small osteoblast vesicles (SOVs), contain microRNA that interferes with a key protein for osteoblast development, highlighting a new way osteoblasts communicate to regulate bone turnover.
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  • Large bone defects from trauma or tumors are a tough challenge in orthopedic surgery, often requiring artificial bone due to limited autograft options.
  • Current artificial bones mainly serve as fillers and lack the ability to promote bone growth, which limits their effectiveness.
  • This study shows that treating artificial bone surfaces with low-pressure plasma can enhance their properties, leading to better cell adhesion and bone regeneration, suggesting a new approach to improve artificial bone use in surgery.
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Article Synopsis
  • - The study highlights the potential of NOVOSIS putty (NP), which combines various materials including hydroxyapatite and rhBMP-2, for improving bone regeneration while minimizing adverse effects from burst release common in traditional delivery methods.
  • - In vitro tests demonstrated that NP provided a sustained release of rhBMP-2, leading to enhanced osteogenic gene expression in cells, outperforming the collagen sponge (CS) in this aspect.
  • - In an animal model, NP not only resulted in greater volume and quality of new bone compared to CS but also showcased its effectiveness in promoting efficient bone healing through the prolonged release of rhBMP-2.
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Anti-resorptive drugs are widely used for the treatment of osteoporosis, but excessive inhibition of osteoclastogenesis can suppress bone turnover and cause the deterioration of bone quality. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is a transmembrane protein expressed on osteoclast precursor cells and mature osteoclasts. Siglec-15 regulates proteins containing immunoreceptor tyrosine-based activation motif (ITAM) domains, which then induce nuclear factor of activated T-cells 1 (NFATc1), a master transcription factor of osteoclast differentiation.

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Osteoclastic bone resorption and osteoblastic bone formation/replenishment are closely coupled in bone metabolism. Anabolic parathyroid hormone (PTH), which is commonly used for treating osteoporosis, shifts the balance from osteoclastic to osteoblastic, although it is unclear how these cells are coordinately regulated by PTH. Here, we identify a serine protease inhibitor, secretory leukocyte protease inhibitor (SLPI), as a critical mediator that is involved in the PTH-mediated shift to the osteoblastic phase.

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Background Context: Infection around intervertebral fusion cages can be intractable because of the avascular nature of the intervertebral disc space. Intervertebral cages with antibacterial effects may be a method by which this complication can be prevented.

Purpose: To investigate the bacterial load on the antibacterial coating cages for spinal interbody fusion STUDY DESIGN: An experimental in vitro and in vivo study.

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Spondyloarthritis (SpA) is a subset of seronegative rheumatic-related autoimmune diseases that consist of ankylosing spondylitis (AS), psoriatic spondylitis (PsA), reactive spondylitis (re-SpA), inflammatory bowel disease (IBD)-associated spondylitis, and unclassifiable spondylitis. These subsets share clinical phenotypes such as joint inflammation and extra-articular manifestations (uveitis, IBD, and psoriasis [Ps]). Inflammation at the enthesis, where ligaments and tendons attach to bones, characterizes and distinguishes SpA from other types of arthritis.

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Bone morphogenetic protein (BMP)-2 plays a central role in bone-tissue engineering because of its potent bone-induction ability. However, the process of BMP-induced bone formation in vivo remains poorly elucidated. Here, we aimed to establish a method for intravital imaging of the entire process of BMP-2-induced ectopic bone formation.

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Osteoporosis is an unavoidable public health problem in an aging or aged society. Anti-resorptive agents (calcitonin, estrogen, and selective estrogen-receptor modulators, bisphosphonates, anti-receptor activator of nuclear factor κB ligand antibody along with calcium and vitamin D supplementations) and anabolic agents (parathyroid hormone and related peptide analogs, sclerostin inhibitors) have major roles in current treatment regimens and are used alone or in combination based on the pathological condition. Recent advancements in the molecular understanding of bone metabolism and in bioengineering will open the door to future treatment paradigms for osteoporosis, including antibody agents, stem cells, and gene therapies.

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Background Context: Spinal cord injury (SCI) results in not only motor dysfunction but also chronic neuropathic pain. Allodynia, an abnormal sensation that evokes pain against non-noxious stimuli, is a major symptom of post-SCI neuropathic pain. Astrocytic activation is a cause of post-SCI neuropathic pain and is considered a key treatment target.

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In this era of aging societies, the number of elderly individuals who undergo spinal arthrodesis for various degenerative diseases is increasing. Poor bone quality and osteogenic ability in older patients, due to osteoporosis, often interfere with achieving bone fusion after spinal arthrodesis. Enhancement of bone fusion requires shifting bone homeostasis toward increased bone formation and reduced resorption.

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Background: Lateral inter-body fusion (LIF) using cages with a large bone grafting space can lead to a shortage of autologous grafting materials. The use of artificial bone is an option to increase the volume of grafting materials. However, the rate of bony fusion for these materials compared to that of autologous bone is unclear.

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