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Tsukuba, Japan

Tsukuba International University is a private university in Tsuchiura, Ibaraki Prefecture, Japan, established in 1994. The predecessor of the school was founded in 1946. Wikipedia.

Fukaya T.,Tsukuba International University | Mutsuzaki H.,Ibaraki Prefectural University of Health Sciences | Wadano Y.,Ibaraki Prefectural University of Health Sciences
Knee | Year: 2015

Background: The purposes of this study were to understand the kinematics changes in the frontal and horizontal planes with severe medial knee OA at the stance phase and to examine the relationship between varus and rotational movements. Methods: The OA group comprised 18 knees in 12 subjects (five men, seven women) with a Kellgren-Lawrence grade of three or four in at least one knee. From the results of gait analysis, we calculated Spearman rank-correlation coefficients for the following items: varus angle at initial contact (IC); varus angle at loading response (LR); amount of varus thrust from IC to LR; rotational angle at IC; rotational angle at LR and amount of rotational angle change from IC to LR. Results: The results indicated that, as the external rotation angle at IC and internal rotational movement from IC to LR increased, the maximum varus angle to LR showed a tendency to become large. In addition, varus thrust showed a tendency to become larger as the external rotation angles increased at IC and LR. The subjects with severe knee OA showed a strong correlation between the knee varus angle at IC and at LR. Furthermore, an increase in movement to internal rotation of the knee during the initial stance phase increased the knee varus angle at LR. Conclusions: The control of the rotational movement according to the extent of varus thrust during the initial stance phase may have possible effects to decrease the load on the medial compartment of the knee. © 2015 Elsevier B.V..

Fukaya T.,Tsukuba International University | Mutsuzaki H.,Ibaraki Prefectural University of Health Sciences | Wadano Y.,Ibaraki Prefectural University of Health Sciences
Journal of Mechanics in Medicine and Biology | Year: 2013

The angular jerk cost (AJC) was proposed to objectively represent the smoothness of joint movement by calculating the time-dependent changes in acceleration during motion. There are currently no reports focusing on smoothness using AJC measurements of the knee joint movement during the stance phase of gait. The purpose of this study was to verify whether a reduced walking speed affects the smoothness of the knee joint movement during the stance phase of gait. The gaits of 12 healthy adults were assessed. A slower walker showed a significant reduction in the AJC value in the period between the initial contact and the loading response, as compared with someone walking at a comfortable speed. The maximum ground reaction force of the stance phase at a comfortable walking speed was significantly larger than that at a slower walking speed. Thus, although the smoothness of the knee joint was impaired by a rapid load in the early stance phase, a slower walking speed reduced the ground reaction force and angular acceleration of the knee joint and created a smoother movement. The AJC can be an important index for understanding the smoothness of the knee joint in the early stance phase. © 2013 World Scientific Publishing Company.

Saito S.,Tohoku University | Saito S.,Japan National Institute of Radiological Sciences | Aoki I.,Japan National Institute of Radiological Sciences | Sawada K.,Tsukuba International University | And 2 more authors.
NMR in Biomedicine | Year: 2012

Prenatal radiation exposure induces various central nervous system (CNS) disorders depending on the dose, affected region and gestation period. The goal of this study was to assess noninvasively a CNS development disorder induced by prenatal X-ray exposure using quantitative manganese-enhanced MRI (MEMRI) as well as apparent diffusion coefficient (ADC) and transverse relaxation time (T 2) maps in comparison with immunohistological staining. The changes in ΔR 1 (increase in the longitudinal relaxation rate (R 1) from before and after MnCl 2 administration.) induced by the Mn 2+ contrast agent were evaluated in the CNS of normal and prenatally irradiated rats. ADC and T 2 were also compared with the histological results obtained using hematoxylin and eosin (to estimate cell density), activated caspase-3 (apoptotic cells) and glial fibrillary acidic protein (proliferation of astrocytes/astroglia). We found the following: (i) the decreased Mn 2+ uptake (indicated by a smaller ΔR 1) for radiation-exposed rats was predominantly correlated with a decrease in cell viability (apoptotic cytopathogenicity) and CNS cell density after prenatal radiation exposure; (ii) the longer T 2 and ADC were associated with a decrease in CNS cell density and apoptotic alteration after radiation exposure. In addition to the slight proliferation of astroglia (+58%), there was a substantial decrease in cell density (-78%) and an excessive increase in apoptotic cells (+613%) in our prenatal radiation exposure model. The results suggest that MEMRI in the prenatal X-ray exposure model predominantly reflected the decrease in cell density and viability rather than the proliferation of astroglia. In conclusion, quantitative MEMRI with ADC/T 2 mapping provides objective information for the in vivo assessment of cellular level alterations by prenatal radiation exposure, and has the potential to be used as a standard approach for the evaluation of the cellular damage of radiotherapy. © 2011 John Wiley & Sons, Ltd.

Though l-arginine-containing polymers show versatile biological functions, a precisely controlled synthesis of poly(ethylene glycol)-b-poly(l-arginine) (PEG-b-PArg) block copolymers has not been reported. Here, an effective method for the synthesis of PEG-b-PArg block copolymers is developed. In order to obtain PEG-b-PArg, a two-step reaction, i.e., synthesis of PEG-b-poly(l-ornithine) is employed, followed by guanidinylation with N,N'-bis(tert-butoxycarbonyl)-1H-pyrazole-1-carboxamidine. This procedure quantitatively converts amino groups to guanidium groups at the side chains of peptide segments under mild conditions. Polyion complex (PIC) micelles are prepared by mixing the positively charged PEG-b-PArg with negatively charged homo-polyelectrolytes such as hyaluronic acid (HA) or chondroitin sulfate C (CS). PIC micelles prepared with CS show a higher stability than those prepared with HA, probably due to strong interactions between guanidium cations in PEG-b-PArg and carboxylate/sulfate in CS. Thus, PIC micelles containing PArg are a potentially effective arginine carrier for the development of in vivo therapeutic applications for various diseases related to nitric oxide, which is generated from inducible nitric oxide synthase in macrophages using l-arginine as a substrate. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sawada K.,Tsukuba International University | Horiuchi-Hirose M.,Tsukuba International University | Saito S.,Osaka University | Aoki I.,Japan National Institute of Radiological Sciences
NeuroImage | Year: 2013

The present study aimed to characterize cerebral morphology in young adult ferrets and its sexual dimorphism using high-field MRI and MRI-based morphometry. Ex vivo short TR/TE (typical T1-weighted parameter setting for conventional MRI) and T2W (long TR/TE) MRI with high spatial resolution at 7-tesla could visualize major subcortical and archicortical structures, i.e., the caudate nucleus, lentiform nucleus, amygdala and hippocampus. In particular, laminar organization of the olfactory bulb was identifiable by short TR/TE-MRI. The primary and secondary sulci observable in the adult ferret were distinguishable on either short TR/TE- or T2W-MRI, and the cortical surface morphology was reproduced well by 3D-rendered images obtained by short TR/TE-MRI. The cerebrum had a significantly lower volume in females than in males, which was attributed to region-specific volume reduction in the cerebral cortex and subcortical white matter in females. A sexual difference was also detected, manifested by an overall reduction in normalized signal ratios of short TR/TE-MRI in all cerebral structures examined in females than in males. On the other hand, an alternating array of higher and lower short TR/TE-MRI intensity transverse zones throughout the cortex, which was reminiscent of the functional cortical areas, was revealed by maximum intensity projection (MIP) in 3D. The normalized signal ratio of short TR/TE-MRI, but not T2W-MRI in the cortex, was negatively correlated with the density of myelin-basic protein immunoreactive fibers (males, r=-0.440; females, r=-0.481). The present results suggest that sexual differences in the adult ferret cerebrum are characterized by reduced volumes of the cerebral cortex and subcortical white matter in females, and by overall reductions in physiochemical characteristics, as obtained by short TR/TE-MRI, in females. It should be noted that short TR/TE-MRI-based MIP delineated functional cortical areas related to myeloarchitecture in 3D. Such an approach makes possible conventional investigation of the functional organization of the cerebral cortex and its abnormalities using high-field MRI. © 2013 Elsevier Inc.

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