Publications by authors named "Keiko Okamoto"

Background: The vascularity index (VI) is useful for measuring the hemodynamics on ultrasound imaging. However, there are no reports concerning the application of the VI to facial muscles.

Objective: The aim of this study was (1) to establish a method of measuring the hemodynamics in facial muscles in a constant way and (2) to evaluate the hemodynamic changes in the masseter and superior orbicularis oris muscles (SOOMs) before and after exercise load in two subject groups of females of different ages.

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Aims: The aim of this study is to investigate the effects of a low-carbohydrate staple food (i.e., low-carbohydrate bread) on glucose and lipid metabolism and pancreatic and enteroendocrine hormone secretion in comparison with meals containing normal-carbohydrate bread, without consideration of the carbohydrate content of the side dishes.

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Takeda G protein-coupled receptor 5 (TGR5) agonists induce systemic release of glucagon-like peptides (GLPs) from intestinal L cells, a potentially therapeutic action against metabolic diseases such as nonalcoholic steatohepatitis (NASH), nonalcoholic fatty liver disease (NAFLD), and Type 2 diabetes. Historically, TGR5 agonist use has been hindered by side effects, including inhibition of gallbladder emptying. Here, we characterize RDX8940, a novel, orally administered TGR5 agonist designed to have minimal systemic effects and investigate its activity in mice fed a Western diet, a model of NAFLD and mild insulin resistance.

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When two or more candle flames are fused by approaching them together, the resulting large flame often exhibits flickering, i.e., prolonged high-frequency oscillation in its size and luminance.

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Because a rank-ordered recruitment of motor units occurs during isometric contraction of jaw-closing muscles, jaw-closing motoneurons (MNs) may be recruited in a manner dependent on their soma sizes or input resistances (IRs). In the dorsolateral part of the trigeminal motor nucleus (dl-TMN) in rats, MNs abundantly express TWIK (two-pore domain weak inwardly rectifying K channel)-related acid-sensitive-K(+) channel (TASK)-1 and TASK3 channels, which determine the IR and resting membrane potential. Here we examined how TASK channels are involved in IR-dependent activation/recruitment of MNs in the rat dl-TMN by using multiple methods.

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We developed an efficient screening method for Saccharomyces cerevisiae strains from environmental isolates. MultiPlex PCR was performed targeting four brewing S. cerevisiae genes (SSU1, AWA1, BIO6, and FLO1).

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GABA(A) receptors are pentamers in structure and are mainly composed of alpha, beta and gamma subunits. These receptors are known to function as chloride channels. We observed alpha5, beta1 and gamma3 subunit immunoreactivity in the mouse testes, specifically in the cytoplasm surrounding the nucleus in the spermatocytes and spermatids.

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Mammalian glycerophosphodiester phosphodiesterases (GP-PDEs) have been identified recently and shown to be implicated in several physiological functions. This study isolated a novel GP-PDE, GDE5, and showed that GDE5 selectively hydrolyzes glycerophosphocholine (GroPCho) and controls skeletal muscle development. We show that GDE5 expression was reduced in atrophied skeletal muscles in mice and that decreasing GDE5 abundance promoted myoblastic differentiation, suggesting that decreased GDE5 expression has a counter-regulatory effect on the progression of skeletal muscle atrophy.

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An intercostal nerve obtained from a human cadaver 6 h post-mortem was transplanted into the rat sciatic nerve and nerve regeneration was observed 4 and 8 weeks after surgery. Sciatic nerves from deceased rats up to 2 days post-mortem were also transplanted for comparison. Good nerve regeneration was observed through the human cadaver-derived graft to the distal segment at the medial plantal nerve 8 weeks after surgery.

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The GABAergic system, a major inhibitory regulator in the central nervous system, may also play important roles in peripheral nonneuronal tissues and cells. Recent studies showed that GABAB receptor is expressed in testis and sperm. To understand the role of the GABAergic system in spermiogenesis, we examined cellular localization of GABA and GABAB receptor subunits in rat spermatids by immunocytochemistry.

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Gamma-aminobutyric acid (GABA)ergic neurons in the neocortex have been mainly regarded as interneurons and thought to provide local interactions. Recently, however, glutamate decarboxylase (GAD) immunocytochemistry combined with retrograde labeling experiments revealed the existence of GABAergic projection neurons in the neocortex. We further studied the network of GABAergic projection neurons in the neocortex by using GAD67-green fluorescent protein (GFP) knock-in mice for retrograde labeling and a novel neocortical GABAergic neuron labeling method for axon tracing.

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The neostriatum is known to receive glutamatergic projections from the cerebral cortex and thalamic nuclei. Vesicular glutamate transporters 1 and 2 (VGluT1 and VGluT2) are located on axon terminals of corticostriatal and thalamostriatal afferents, respectively, whereas VGluT3 is found in axon terminals of cholinergic interneurons in the neostriatum. In the present study, the postsynaptic localization of ionotropic glutamate receptors was examined in rat neostriatum by the postembedding immunogold method for double labelling of VGluT and glutamate receptors.

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It has been reported in the cat and rat that inhibitory premotor neurons, which send their axons to motoneurons of the trigeminal motor nucleus (Vm) are distributed in the reticular regions around the Vm, especially in the supratrigeminal region (Vsup) and the intertrigeminal region (Vint). In the present study, we examined neuronal connections of GABAergic neurons in the Vsup and Vint in the mouse by utilizing the adult heterozygous GAD67-GFP knock-in mouse, in which green fluorescence protein (GFP) is expressed in GABAergic neurons under the control of the endogenous GAD (GAD67) gene promoter [Yanagawa, Y., Kaneko, K.

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Intra- or juxta-columnar connections of pyramidal neurons to corticospinal neurons in rat motorsensory cortices were examined with brain slices by combining intracellular staining with Golgi-like retrograde labeling of corticospinal neurons. Of 108 intracellularly labeled pyramidal neurons, 27 neurons were selected for morphological analysis by successful staining of their axonal arborizations and sufficient retrograde labeling of corticospinal neurons. Many varicosities of local axon collaterals of each pyramidal neuron were closely apposed to the dendrites of corticospinal neurons, suggesting the convergent projections of layer II-VI pyramidal neurons to corticospinal neurons.

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Using a methodology recently developed for studying the product distributions of gas-phase S(N)2 and E2 reactions, the effect of the leaving group on the reaction rate and branching ratio was investigated. Using a dianion as the nucleophile, reactions with a series of alkyl bromides, iodides, and trifluoroacetates were examined. The alkyl groups in the study are ethyl, n-propyl, n-butyl, isobutyl, isopropyl, sec-butyl, and tert-butyl.

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The collision-activated dissociations (CAD) of gas phase salt complexes composed of chiral ions were studied in a quadrupole ion trap mass spectrometer. Because both partners in the salt are chiral, diastereomeric complexes can be formed (e.g.

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Expression of vesicular glutamate transporters (VGLUTs: VGLUT1, VGLUT2 and VGLUT3) in muscle spindle afferents was examined in rats. VGLUT1 immunoreactivity was detected in the sensory endings on the equatorial and juxta-equatarial regions of intrafusal fibers as well as in many axon terminals within lamina IX of the spinal cord. VGLUT1 might be expressed not only in the central axon terminals but also in the peripheral sensory endings of muscle-spindle afferents.

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To characterize glutamatergic axon terminals onto sympathetic preganglionic neurons (SPNs), we visualized immunohistochemically three vesicular glutamate transporters (VGLUTs) in the intermediolateral cell column (IML) of rat thoracic spinal cord. VGLUT2 and VGLUT3 immunoreactivities but not VGLUT1 immunoreactivity were distributed in the IML and found in terminals making asymmetric synapses and apposed to dendrites immunopositive for choline acetyltransferase, an SPN marker. VGLUT2 and VGLUT3 immunoreactivities were not co-localized with each other.

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To clarify which vesicular glutamate transporter (VGluT) is used by excitatory axon terminals of the retinofugal system, we examined immunoreactivities and mRNA signals for VGluT1 and VGluT2 in the rat retina and compared immunoreactivities for VGluT1 and VGluT2 in the retinorecipient regions using double immunofluorescence method, anterograde tracing, and immunoelectron microscopy. Furthermore, the changes of VGluT1 and VGluT2 immunoreactivities were studied after eyeball enucleation. Intense immunoreactivity and mRNA signal for VGluT2, but not for VGluT1 immunoreactivity, were observed in most perikarya of ganglion cells in the retina.

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The supratrigeminal region (STR), a reticular zone capping the motor trigeminal nucleus (Tm), contains gamma-aminobutyric acid (GABA)ergic and glycinergic neurons which send axons to the contralateral Tm (J. Comp. Neurol.

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The human amnion consists of the epithelial cell layer and underlying connective tissue. After removing the epithelial cells, the resulting acellular connective tissue matrix was manufactured into thin dry sheets called amnion matrix sheets. The sheets were further processed into tubes, amnion matrix tubes (AMTs), of varying diameters, with the walls of varying numbers of amnion matrix sheets with or without a gelatin coating.

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