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Hyaluronan (HA) is an extracellular matrix glycosaminoglycan essential for the homeostasis of cartilage-related tissues. Intracellular adhesion molecule-1 (ICAM-1) and CD44 have been identified as receptors for HA. Recently, transient receptor potential vanilloid 4 (TRPV4) has emerged as a potential research target in several areas of physiology. TRPV4 is a Ca2+-permeable, non-selective cation channel that appears to have mechanosensory or osmosensory roles in several musculoskeletal tissues. HA and TRPV4 play key roles in chondrogenesis; however, it has remained unclear whether they have interactive effects on chondrogenesis and, if so, how do they interact with each other? This study investigated the relationship between HA, its receptors ICAM-1 and CD44, and TRPV4 in the chondrogenic pathway using the ATDC5 cell line. It was found that the presence of HA is required for TRPV4-induced chondrogenesis. Loss of HA suppressed TRPV4-induced expression of the chondrogenic markers, SOX9 and Aggrecan. Moreover, HA affects TRPV4-induced chondrogenic development via each of ICAM-1 and CD44 partially. In conclusion, for the first time, the existence of an interaction between HA, its receptor ICAM-1 and CD44, and TRPV4-activity in chondrogenesis in the ATDC5 cell line was reported. TRPV4 is known to function as a mechanosensory channel in several musculoskeletal tissues. Therefore, findings of this study may suggest the existence of a molecular mechanism that underlies the interactive effects of HA and mechanical loading on joint chondrogenesis.

In the material designing process of footwear outer-soles, a grip property of rubber is of crucial importance under water or oil lubricated condition. In general, contact states between rubber and floors under lubricated conditions are influenced by various factors, i. e. viscosity of a lubricant, sliding velocity, normal force, surface roughness and wettability between the two substrates. It has been said that lubrication conditions can be distinguished based on Stribeck curves, which are described by the relationship between Sommerfeld numbers and dynamic friction coefficients. Wettability under the static condition is estimated by the spreading coefficient, which is used to evaluate the energy balance of interface free energies at a triple line. The purpose of this study is to investigate influences of surface free energies, viscosities, sliding velocities and surface roughnesses on dynamic friction coefficients of rubber under lubricated conditions. The influences of spreading coefficients on the behaviors of Stribeck curves and the relationship between dewetting velocities and dynamic friction coefficients are also discussed.

Fiber reinforced thermoplastics (FRTP) attracts attention as a lightweight material for mass-produced automobiles due to advantages such as excellent formability and recyclability in addition to high specific strength and specific rigidity. Many factors influence the improvement of the mechanical properties of FRTP. We have revealed that the tensile strength of injection-molded glass fiber/polyamide66 (GF/PA) improves as the reinforcement fiber diameter decreases in the wide strain rate range in previous researches. In addition, it was suggested that by using a strength prediction model of discontinuous fiber reinforcement, if the strength can be obtained for one diameter, the strength can be predicted for other diameters. In this study, we investigated the mechanism of the strength enhancement of the GF/PA associated with thinning of the reinforcement fibers and increase of the strain rate. To ascertain the interface properties, single-fiber pull-out tests were conducted on the GF/PA and it was confirmed that the interfacial shear strength (IFSS) of the GF/PA had strain rate dependency. The strength prediction of the GF/PA with the strain rate dependency of IFSS taken into account showed values closer to the experimental values than the values obtained from the prediction with an assumption that IFSS is constant regardless of the strain rate. Furthermore, investigating the factor of the increase in strength due to the thinning of the fibers suggested that the increase of the fiber strength is the dominant factor.

OBJECTIVE:The current guideline recommends lowering low-density lipoprotein cholesterol (LDL-C) for the primary management of dyslipidemia in patients at high-risk of cardiovascular events. Patients who have achieved LDL-C levels below the recommended targets may still experience cardiovascular events, suggesting additional therapeutic targets beyond LDL-C. The aim of this study was to investigate whether high-density lipoprotein cholesterol (HDL-C) levels had an impact on plaque stabilization in patients with acute coronary syndrome (ACS). METHODS:This study consisted of 90 ACS patients with untreated dyslipidemia. In optical coherence tomography (OCT) analysis, a plaque with fibrous cap thickness ≦160 μm was defined as a high-risk plaque. We registered one high-risk plaque per one patient by baseline OCT imaging, and then administrated high-intensity statin. Based on the follow-up OCT results, patients whose registered plaque was no longer high-risk plaque were classified into a responder group and the remains into a non-responder group. RESULTS:No differences were observed in the baseline LDL-C and HDL-C levels between the two groups. Reduction of LDL-C levels (δ LDL-C: -53 ± 21 mg/dL vs. -42 ± 29 mg/dL, p = 0.036) and increase of HDL-C levels (δ HDL-C: 2.5 ± 5.9 mg/dL vs. -0.3 ± 6.7 mg/dL, p = 0.039) were greater in the responder group. On multivariate logistic regression analysis, δ LDL-C levels (OR: 0.956, 95% CI: 0.921-0.993; p = 0.020) and δ HDL-C levels (OR: 1.143; 95% CI: 1.005-1.300, p = 0.041) were independent contributors for plaque stabilization. CONCLUSIONS:Increase of HDL-C levels is associated with plaque stabilization in patients with ACS. HDL-C could be a therapeutic target for residual risk management.

Applications of fiber reinforced plastics have been expanding due to improvement of not only fuel efficiency but also the motion performance of some recent vehicles. Especially, the demand for injection-molded fiber reinforced thermoplastics is expected to increase because of their superior moldability, productivity and recyclability. In this study, the influence the fiber diameter has on the impact tensile properties of long glass-fiber reinforced polyamide (GF/PA) is investigated using the split Hopkinson pressure bar method. Prior to the tensile tests, an investigation of the fiber-orientation distribution was conducted in order to cut out specimens with the same fiber orientation angle from the injection molded plate. Two types of specimens, referred to as specimens with high- and low orientation angle, were manufactured using glass fibers with average diameters of 13, 17, 23 μm. In the tensile test, the GF/PA with smallest fiber diameter showed the highest tensile strength and the most significant strain rate dependency on the strength. These effects were more significant for the specimens with high orientation angle. From SEM observations on the fracture surface and an average fiber length measurement, it was observed that the interfacial fracture and the fiber breakage were dominant failure modes under the considered tensile loading conditions. It was suggested that decreasing the stress acting on the fiber/matrix interface by reducing the fiber diameter affected the improvement of the GF/PA strength. Using the modified linear rule of mixtures, the tensile strength was predicted. The predictions showed good agreement with experimental results. Therefore, it is believed that the decrease of critical fiber length is the reason that the impact tensile properties are higher for the samples with smaller fiber diameter.

Relationship between shoe grip properties and distributions of traction coefficient, which is obtained from horizontal ground reaction force (GRF) divided by normal GRF, were experimentally investigated during running. The experiments were conducted with sensor shoes mounted miniature triaxial force sensors for the measurement of GRF distributions in contact area. In order to clarify influence of the grip property on GRF vectors distributions and traction coefficient distributions, two typed sensor shoes having different outer sole materials with high/low friction coefficients were developed. The results showed that traction coefficients for the low grip typed shoe decreased in the whole contact area at the end of stance phase during running. Furthermore, it was confirmed that contact area, directions of GRF vectors and traction coefficients locally changed depending on the grip property. As a result of relationship between distributions of propulsion force components at 19 local positions and stride length, production of propulsion force beneath toe area can efficiently acquire sufficient stride length to keep running speed.

The present study was designed to elucidate the involvement of tumor necrosis factor-α (TNF-α) release from activated microglia in the induction of blood–brain barrier (BBB) dysfunction in an in vitro co-culture system with mouse brain capillary endothelial cells (MBEC4) and microglia. Lipopolysaccharide (LPS)–activated microglia increased the permeability of MBEC4 cells to sodium-fluorescein, and this hyper-permeability was blocked by a neutralizing antibody against TNF-α. LPS stimulated microglia to facilitate TNF-α release. These findings suggested that TNF-α released from activated microglia is attributable to BBB dysfunction. Keywords:: microglia, tumor necrosis factor-α (TNF-α), blood–brain barrier

The aim of the present study was to elucidate the effects of indapamide on ischemic damage to the blood-brain barrier (BBB) in vitro. The ischemia /reperfusion conditions employed here significantly decreased the viability of mouse brain capillary endothelial (MBEC4) cells, an effect ameliorated by indapamide. Ischemia increased the permeability of MBEC4 cells to two cellular transport markers, sodium fluorescein and Evan’s blue-albumin. Indapamide reduced the ischemia-induced hyperpermeability of cells. These results suggest that indapamide may have a protective role against ischemia-induced injury and dysfunction of the BBB. Keywords:: indapamide, ischemia, blood-brain barrier

Abstract.: Vasospasm after subarachnoid hemorrhage (SAH) is a serious complication and we have been investigating the relationship between vasoconstrictors and vasospasm after SAH. The present study was designed to investigate the vasocontractile responses to reactive oxygen species in isolated rat basilar arteries from the control and experimental SAH rats. Contractile responses to hydroxyl radicals in basilar arteries from SAH rats were 3 – 6-fold higher than those in control rats. The present results clearly indicate that hypersensitivity to hydroxyl radicals may contribute to the vasospasm after SAH. Keywords:: subarachnoid hemorrhage, hydroxyl radical, rat basilar artery

We developed a spectral-domain optical coherence tomography (OCT) using a visible broadband light source (vis-OCT) for application to high-resolution and nondestructive profile measurement and imaging in semiconductor optical-device fabrication. By using visible broadband light centered at 625 nm and with spectral bandwidth of 260 nm, an axial resolution of 0.69 µm in air was obtained. This was effective for inspection of a transparent photoresist film with thickness of 1–2 µm coated on a semiconductor wafer; the interface between the photoresist film and its substrate and the interface between the photoresist and air were resolved, and the film thickness was measured. In addition, the interface between an opaque epitaxially grown semiconductor layer (Al0.35Ga0.65As) and a GaAs substrate was also detected by vis-OCT. Here we propose a thickness-measurement technique that combines finite-difference time-domain simulation with vis-OCT. This method enables us to determine the thickness of even an optically absorbent epitaxial layer and offers a profile-measurement method that is particularly suitable for the fabrication of semiconductor optical devices. [ABSTRACT FROM AUTHOR]