Publications by authors named "Yamawaki Y"

Tenosynovitis with psammomatous calcification (TPC) is an extremely rare condition. It was first described as a characteristic subtype of idiopathic calcifying tenosynovitis, with only 40 cases reported to date. Here, we present a case of TPC affecting a female patient in her late teens, with no relevant medical history.

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  • - The study investigates how periodontal disease impacts cognitive function in a mouse model of diet-induced obesity, focusing on the role of microglia, which are immune cells in the brain.
  • - Male C57BL/6 J mice were fed a high-fat diet for 18 weeks to induce obesity and then exposed to a periodontal pathogen to mimic periodontitis over a 6-week period.
  • - Results showed that the obese mice with periodontal infection had cognitive impairments and activated microglia in the brain, and reducing microglia improved their cognitive function, suggesting that microglia play a key role in this link.
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  • A study explored the use of an anatomical artificial bone implant for improving alignment during open-wedge high tibial osteotomy by analyzing the shape of the osteotomy surface and assessing its effectiveness in achieving precise corrections.
  • Using virtual simulations and cadaver tests, researchers created a 10° correction angle implant and compared its accuracy in maintaining posterior tibial slope and rotation against conventional wedge-shaped spacers in real-life surgeries.
  • Results showed that the anatomical implant had high contour compatibility and minimal changes in tibial alignment, effectively reducing errors in correction angles compared to traditional methods.
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Background: Medial soft tissue release is occasionally performed to achieve mediolateral ligament balance in total knee arthroplasty (TKA), whose sequential effect on mediolateral and anteroposterior stability remains unclear. This study aimed to quantitatively evaluate the difference in mediolateral and anteroposterior stability according to a sequential medial soft tissue release in TKA.

Methods: Cruciate-retaining TKA was performed in six cadaveric knees.

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This study investigated the effects of the time interval between virtual reality (VR) sessions on visually induced motion sickness (VIMS) reduction to better understand adaptation to and recovery from a nauseating VR experience. The participants experienced two 6-min VR sessions of a first-person motorcycle ride through a head-mounted display with (1) a 6-min interval, (2) an interval until the VIMS score reached zero, and (3) a 60-min interval. The results showed that for each condition, VIMS in the second session was aggravated, unchanged, or attenuated, respectively, indicating that additional resting time was necessary for VIMS adaptation.

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Purpose: The degree to which varus knees can be corrected manually is important when considering total versus unicompartmental knee arthroplasty (UKA). The primary aim was to clarify the relationship between the degree of coronal alignment correction and radiographic parameters involved in UKA prognosis using preoperative full-length lower extremity valgus stress radiography. The secondary aim was to identify the factors affecting alignment correction.

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  • - This study compares single-radius and multi-radius designs in total knee arthroplasty to see how they affect knee movement and ligament forces during activities like squatting and walking.
  • - In computer simulations, the multi-radius design showed significant anterior translation of the femur, resulting in decreased tension in the medial collateral ligament during early flexion, while the single-radius model maintained consistent ligament tension.
  • - The findings suggest that choosing a single-radius design may help prevent mid-flexion instability by offering more stability and less movement of the femur compared to the multi-radius model.
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Background: Patellofemoral arthroplasty (PFA) is reported to provide nearly normal PF joint kinematics but only with adequate surgical techniques. This study evaluated the effects of various femoral component settings on patellar component biomechanics.

Methods: A dynamic musculoskeletal computer simulation analyzed normal knee and standard PFA models, as well as 8 femoral component malposition models: 5° internal or external rotation, 5° valgus or varus, 5° extension or flexion, and 3-mm or 5-mm anterior positioning.

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Foreleg trajectory in the mantis strike varies depending on prey distance. To examine how muscle activities affect foreleg trajectory, we recorded strike behaviours of the Chinese mantis with a high-speed camera and electromyograms of the foreleg trochanteral extensor and flexor. At the approach phase of the mantis strike, the prothorax-coxa (P-C) joint elevated and the femur-tibia (F-T) joint extended.

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Lipopolysaccharide (LPS), an outer component of Gram-negative bacteria, induces a strong response of innate immunity via microglia, which triggers a modulation of the intrinsic excitability of neurons. However, it is unclear whether the modulation of neurophysiological properties is similar among neurons. Here, we found the hypoexcitability of layer 5 (L5) pyramidal neurons after exposure to LPS in the medial prefrontal cortex (mPFC) of juvenile rats.

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Background: Decreases of collagen fibers and the disappearance of oxytalan fibers are typical symptoms of photoaged skin. Although a low quality of mitochondria (MT) in photoaged skin cells has been observed, it is unknown whether the decreased quality of MT is responsible for the insufficient formation of dermal fibers.

Objective: To identify the role of mitochondrial quality in skin photoaging focusing on the formation of dermal fibers.

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Porphyromonas gingivalis (P. gingivalis) is a Gram-negative anaerobe involved in the pathogenesis of chronic periodontitis, including local inflammation of the oral cavity. However, periodontal disease has recently been identified as a significant factor in the pathogenesis of neural diseases, including Alzheimer's disease.

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is a relatively new species of black fungi that can cause infection that primarily affects the skin and soft tissues in humans. Black fungal infection is challenging to diagnose and often needs surgery. However, few studies have reported black fungal and infections in the field of plastic surgery.

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Purpose: This study evaluated the clinical outcomes of medial open-wedge high tibial osteotomy (MOWHTO) and bone marrow lesion (BML) scores and volumes. The hypotheses were that quantitative BML volume is more associated with clinical outcomes of MOWHTO than qualitative BML evaluations, and pre-operative BML volume is associated with the improvement of clinical outcomes.

Methods: Patients who underwent MOWHTO were retrospectively enrolled.

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Purpose: The primary aim of this study was to evaluate the 3-dimensional morphology of the proximal tibia around the osteotomy plane in open-wedge high tibial osteotomy, focusing on the posterolateral (PL) and posteromedial (PM) tibial condyles, and to clarify the changes in morphologic parameters due to differences in patient characteristics and hinge position. The secondary aim was to examine whether morphologic features were associated with insufficient osteotomy, which increases the risk of lateral hinge fracture (LHF).

Methods: The PL and PM anteroposterior distance, asymmetry ratio, and discrepancy between PL and PM distances along the tibial osteotomy plane were measured.

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Individuals with pachydrusen, larger than 125 m, have a significantly thicker choroid than do those with soft drusen or reticular pseudodrusen. Little is known about cases of abnormal blood flow within pachydrusen. The purpose of this report was to demonstrate a blood flow signal within pachydrusen using optical coherence tomography (OCT) angiography.

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  • Neuroimmune interactions between the immune system and the CNS, as well as organs like the liver, are crucial in understanding various diseases, including inflammation and neurodegeneration.
  • This study focuses on how lipopolysaccharide (LPS) injections, known to trigger a systemic inflammatory response, can activate unfolded protein responses (UPRs) in different organs.
  • The findings indicate that LPS induces UPRs specifically in the liver, but not in the hypothalamus or hippocampus, and this process occurs independently of the MyD88 protein, potentially impacting disease mechanisms.
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Since probiotic-derived extracellular vesicles (EVs) are capable of activating innate immunity, they are expected to be useful as novel adjuvants. To elucidate the mechanisms underlying the immunostimulatory effects of EVs released from probiotic cells, we newly investigated the role of Toll-like receptor 2 (TLR2) and immune cell downstream signaling in the generation of proinflammatory cytokines. Isolated Bifidobacterium- and Lactobacillus-derived EVs expressed peptidoglycan, one of the major pathogen-associated molecular patterns.

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The correlation between static and dynamic mediolateral (ML) tilts of the joint line in the coronal plane remains unknown after total knee arthroplasty (TKA). The purpose was to evaluate the ML tilt as measured by two-dimensional to three-dimensional registration during stair ascent in TKA patients, and to examine the correlation between the dynamic ML tilt and radiographic measurements of static indices. Thirty-two knees that underwent TKA using the mechanical alignment method were included.

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  • Animals under stress often display learned helplessness, which is linked to changes in serotonin signaling.
  • A study compared serotonin neuron activity in normal rats, learned helplessness rats, and stress-resistant rats after exposure to stressors.
  • The research found that learned helplessness rats had slower serotonin release and reduced spike firing, indicating altered neuronal responses to stress.
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Several concepts may be used to restore normal knee kinematics after total knee arthroplasty. One is a kinematically aligned (KA) technique, which restores the native joint line and limb alignment, and the other is the use of a medial pivot knee (MPK) design, with a ball and socket joint in the medial compartment. This study aimed to compare motions, contact forces, and contact stress between mechanically aligned (MA) and KA (medial tilt 3° [KA3] and 5° [KA5]) models in MPK.

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Although extracellular carbonylated proteins (CPs) are found at higher levels in sun-exposed skin, their impact on the cellular functions of fibroblasts and their involvement in the progression of photoaging skin are not fully clarified. In our previous study, we reported that extracellular CPs increase levels of intracellular oxidative stress and result in the accumulation of newly synthesized CPs in normal human dermal fibroblasts (NHDF). Furthermore, fibroblasts exposed to CP-BSA, which is a model of extracellular CPs, had upregulated expression levels of mRNAs encoding matrix metalloproteinase-1 (MMP-1) and interleukin-8/CXCL8 (IL-8/CXCL8).

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Myeloid differentiation primary response 88 (MyD88) is an adapter protein of the toll-like receptor (TLR) family that regulates innate immune function. Here, we identified a novel role of MyD88 in regulating stress response. MyD88 deficiency decreased immobility time in the forced swim test without affecting locomotor activity in mice.

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Cancer is characterized by uncontrolled proliferation resulting from aberrant cell cycle progression. The activation of phosphatidylinositol 3-kinase (PI3K)/AKT signaling, a regulatory pathway for the cell cycle, stabilizes cyclin D1 in the G1 phase by inhibiting the activity of glycogen synthase kinase 3β (GSK3β) via phosphorylation. We previously reported that phospholipase C-related catalytically inactive protein (PRIP), a phosphatidylinositol 4,5-bisphosphate [PI(4,5)P] binding protein, regulates PI3K/AKT signaling by competitively inhibiting substrate recognition by PI3K.

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