Mitsuhiro Kano
Tohoku University
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Featured researches published by Mitsuhiro Kano.
Cells Tissues Organs | 2005
Yoshinaka Shimizu; Hiroyasu Kanetaka; Yeon-Hwan Kim; Keisuke Okayama; Mitsuhiro Kano; Masayoshi Kikuchi
Object: Age-related morphological changes in the human hyoid bone were investigated radiographically and histologically. Materials and Methods: Thirty-two measurements were performed on radiographs of 238 hyoid bones from autopsy cases of known age and sex. Thirty-one hyoid bones that were studied by radiography were also examined histologically in horizontal sections. Results: Analysis of the length and width of the hyoid bone revealed significant increases in the body and the anterior part of the greater cornu and a significant decrease in the posterior part of the greater cornu with aging. Most measurements of the body and the greater cornu revealed differences between male and female hyoid bones. The outer margins of the body and the greater cornu were situated further outside in older males compared with females. The breadth of the joint space showed a significant age-related decrease, and the degree of fusion showed a significant age-related increase. Histological findings showed ossified or calcified fusion, with osteoclasts in the marginal area of the joint space. Conclusions: Increasing age induces fusion of the body and the greater cornu. The morphometric changes in the shape of the hyoid bone may represent functional adaptation to articulation fixation.
Genes to Cells | 2011
Tada-aki Kudo; Hiroyasu Kanetaka; Kazutoshi Mizuno; Yasuhiro Ryu; Yoshiyuki Miyamoto; Shoko Nunome; Ye Zhang; Mitsuhiro Kano; Yoshinaka Shimizu; Haruhide Hayashi
In this study, we investigated the effect of dorsomorphin, a selective inhibitor of bone morphogenetic protein (BMP) signaling, on rat PC12 pheochromocytoma cell differentiation. PC12 cells can be induced to differentiate into neuron‐like cells possessing elongated neurites by nerve growth factor, BMP2, and other inducers. Cells were incubated with BMP2 and/or dorsomorphin, and the extent of neurite outgrowth was evaluated. Unexpectedly, BMP2‐mediated neuritogenesis was not inhibited by co‐treatment with dorsomorphin. We also found that treatment with dorsomorphin alone, but not another BMP signaling inhibitor, LDN‐193189, induced neurite outgrowth in PC12 cells. To further understand the mechanism of action of dorsomorphin, the effects of this drug on intracellular signaling were investigated using the following signaling inhibitors: the ERK kinase (MEK) inhibitor U0126; the tropomyosin‐related kinase A inhibitor GW441756; and the protein kinase A (PKA) inhibitor H89. Dorsomorphin induced rapid and sustained ERK1/2 activation; however, dorsomorphin‐mediated ERK1/2 activation and neuritogenesis were robustly inhibited in the presence of U0126 or H89, but not GW441756. These findings suggest that dorsomorphin has the potential to induce neuritogenesis in PC12 cells, a response that requires the activation of PKA‐dependent MEK‐ERK1/2 signaling.
Cells Tissues Organs | 2005
Mitsuhiro Kano; Yoshinaka Shimizu; Keisuke Okayama; Toshirou Igari; Masayoshi Kikuchi
The epiglottis plays an important role in deglutition in humans. The present study investigated age-related changes in the epiglottis using macroscopic and microscopic measurements. Epiglottic specimens from 281 Japanese adult cadavers (177 males, 104 females) were obtained. Specimens were divided into three groups according to age: group I: 20–39 years old (32 males, 26 females), group II: 50–69 years old (82 males, 36 females), and group III: 80–98 years old (63 males, 42 females). Width, height, and thickness were measured macroscopically. To evaluate the degree of calcium deposition, the calcium volume in digitalized von Kossa-stained sections was assessed using a quantitative analysis. An elemental analysis of the area detected with von Kossa staining was done using energy-dispersive X-ray fluorescence spectrometer (EDX). Measurements of the thickness and cell density in the superficial and deep layers of epiglottic cartilage were performed in horizontal histological sections. No significant differences in macroscopic width or height were found across the age groups in either sex. A series of three measurements in males was significantly larger than in females (p < 0.05). The volume of the calcium deposit area was greater in males than in females (p < 0.05) and was significantly increased in group III in males (p < 0.05). The lower level of the epiglottic cartilage showed a greater calcium deposit area than the upper level. In the scanning image by line and surface analysis using EDX, the calcium deposit areas detected with von Kossa staining indicated a close association of calcium and phosphorus ions. The mean Ca/P molar ratio in the calcium deposit area was 1.32 ± 0.12. Microscopic cartilage thickness increased significantly with age (p < 0.05), and was greater in males than in females (p < 0.05). Cartilage cell density in the superficial cartilage layer was higher than in the deep layer and was decreased in group III (p < 0.05). Cartilage cell density was lower in males compared to females. Diameter of chondrocytes significantly increased in group III (p < 0.05) and was larger in males than in females in group III (p < 0.05). Epiglottic cartilage exhibited marked sex-related differences and progression of calcification with age. Calcification of epiglottic cartilage in elderly individuals may affect movement patterns in deglutition.
Annals of Anatomy-anatomischer Anzeiger | 2011
Mitsuhiro Kano; Yoshinaka Shimizu; Yujiro Suzuki; Yusuke Furukawa; Hiroko Ishida; Miho Oikawa; Hiroyasu Kanetaka; Hiroyuki Ichikawa; Toshihiko Suzuki
The distribution of pituitary adenylatecyclase-activating polypeptide-immunoreactive (PACAP-IR) nerve fibers was studied in the rat epiglottis and pharynx. PACAP-IR nerve fibers were located beneath the mucous epithelium, and occasionally penetrated the epithelium. These nerve fibers were abundant on the laryngeal side of the epiglottis and in the dorsal and lateral border region between naso-oral and laryngeal parts of the pharynx. PACAP-IR nerve fibers were also detected in taste buds within the epiglottis and pharynx. In addition, many PACAP-IR nerve fibers were found around acinar cells and blood vessels. The double immunofluorescence method demonstrated that distribution of PACAP-IR nerve fibers was similar to that in CGRP-IR nerve fibers in the epithelium and taste bud. However, distributions of PACAP-IR and CGRP-IR nerve fibers innervating mucous glands and blood vessels were different. The retrograde tracing method also demonstrated that PACAP and CGRP were co-expressed by vagal and glossopharyngeal sensory neurons innervating the pharynx. These findings suggest that PACAP-IR nerve fibers in the epithelium and taste bud of the epiglottis and pharynx which originate from the vagal and glossopharyngeal sensory ganglia include nociceptors and chemoreceptors. The origin of PACAP-IR nerve fibers which innervate mucous glands and blood vessels may be the autonomic ganglion.
Archive | 2010
Yoshinaka Shimizu; Akiko Yamamoto; Toshiji Mukai; Yoko Shirai; Mitsuhiro Kano; Tada-aki Kudo; Hiroyasu Kanetaka; Masayoshi Kikuchi
The development of a degrading biomaterial is highly desired for use in new treatment modalities. In the search for degradable materials, a new category of biomaterials made from corroding metals was noticed. Magnesium and its alloys are biodegradable metals and exhibit improved mechanical properties and corrosion resistance compared to pure magnesium and industrial magnesium alloys. Previous research has demonstrated that magnesium alloys have acceptable biocompatibility as new biodegradable biomaterials.
Clinical Anatomy | 2011
Hiroyasu Kanetaka; Yoshinaka Shimizu; Mitsuhiro Kano; Masayoshi Kikuchi
The structure of the joint between the body and the greater cornu in the human hyoid bone was examined histologically in 259 cadavers (16–98 years). Joints were classified into three grades based on histological observations. Grade I showed fibrocartilage without degenerative change in the marginal region of the joint. Grade II showed prominent calcification or ossification on the outer margin of the joint without fusion. Grade III showed bony fusion. Histological changes with age were revealed by a comparison of the prevalences of these three grades among individuals of three age groups: young adult (16–39 years), middle aged (40–69 years), and elderly (70+ years). The frequency of hyoid bones with diarthrodial structure of this joint was compared between the age groups. The mean age of subjects with each grade of histological changes was calculated. Results show that, with age, the proportion of Grade I decreased significantly (P < 0.05) and that of Grade III increased significantly. Joints with diarthrodial structure decreased significantly with age relative to all subjects (P < 0.05). Clefts with necrotic tissue were observed in cartilage along with progressive calcification. The mean age of subjects with the histological changes was significantly higher than that of individuals without such changes (P < 0.05). Calcification and ossification of joints were induced with age from fibrous tissue and cartilage on the outer margin of a joint. The authors suggest that the age changes in the joint between the body and greater cornu of the hyoid bone may affect the mobility of this joint and may be related to masticatory and swallowing functions. Clin. Anat. 24:837–842, 2011.
Cellular and Molecular Neurobiology | 2011
Tadasu Sato; Yoshinaka Shimizu; Mitsuhiro Kano; Toshihiko Suzuki; Hiroyasu Kanetaka; Leona W. G. Chu; Patrice D. Côté; Hidetoshi Shimauchi; Hiroyuki Ichikawa
The distribution of calcitonin gene-related peptide (CGRP) was examined in skeletal muscles of fore and hind limb as well as in oral and cranio-facial regions of the degenerating muscle (dmu) mouse, which harbours a null mutation in the voltage-gated sodium channel gene Scn8a. In limb, oral and cranio-facial muscles of wild type mice, only a few motor endplates contained CGRP-immunoreactivity. However, many CGRP-immunoreactive motor endplates appeared in the triceps brachii muscle, the biceps brachii muscle, the brachialis muscle, and the gastrocnemius muscle of dmu mice. CGRP-immunoreactive density of motor endplates in the skeletal muscles was also elevated by the mutation. In these muscles, the atrophy of muscle fibers could be detected and the density of cell nuclei in the musculature increased. In the flexor digitorum profundus muscle, the flexor digitorum superficialis muscle, and the soleus muscle as well as in oral and cranio-facial muscles, however, the distribution of CGRP-immunoreactivity was barely affected by the mutation. The morphology of muscle fibers and the distribution of cell nuclei within them were also similar in wild type and dmu mice. In the lumbar spinal cord of dmu mice, CGRP-immunoreactive density of spinal motoneurons increased. These findings suggest that the atrophic degeneration in some fore and hind limb muscles of dmu mice may increase CGRP expression in their motoneurons.
Journal of Craniofacial Surgery | 2010
Hiroyasu Kanetaka; Yoshinaka Shimizu; Tada-aki Kudo; Ye Zhang; Mitsuhiro Kano; Yuya Sano; Hiroyuki Ichikawa; Hideki Hosoda; Shuichi Miyazaki
This study was undertaken to examine effects and biocompatibility of a new internalized distraction device made from newly developed Ti-Nb-Al shape memory alloy (SMA). Crania of Wistar rats were expanded using a U-shaped wire of this SMA set on each cranium in an experimental group. At 2 or 4 weeks after operation, the rats were killed; width measurements and three-dimensional observations of crania were conducted using soft x-ray and microfocus x-ray computed tomography photography. After photography, histologic sections were made and stained with hematoxylin and eosin. No pathologic change in the experimental duration was observed macroscopically or histologically. Significantly increased size was found for the rat crania in the experimental group compared with the control group. Results demonstrated the feasibility and biocompatibility of internalized distraction osteogenesis using Ni-free, Ti-based SMA in craniofacial plastic surgery for craniofacial deformities.
Archive | 2010
Ye Zhang; Tada-aki Kudo; Yunchia Ku; Fei Zhao; Mitsuhiro Kano; Yoshinaka Shimizu; Haruhide Hayashi; Taizo Hamada; Hiroyasu Kanetaka
Extracellular signal-regulated kinase 5 (ERK5) plays an important role in the regulation of cell proliferation and differentiation. Recent data suggest that ERK5 is activated by neurotrophic factors in various types of neurons and induces neurotrophin-mediated neuronal survival. This report provides advanced findings on the mechanism underlying ERK5-mediated neuroprotection.
Archive | 2010
Fei Zhao; Tada-aki Kudo; Ye Zhang; Mitsuhiro Kano; Shinri Tamura; Yoshinaka Shimizu; Hiroyasu Kanetaka; Haruhide Hayashi
Bone morphogenetic protein (BMP) signaling is essential for neurogenesis and bone formation. Dullard phosphatase functions as a negative regulator of BMP signaling by promoting the dephosphorylation or degradation of BMP receptors. In contrast, dullard regulates nuclear membrane biogenesis. This report aims to characterize dullard and determine the role played by it in cellular signaling.