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Kawasaki, Japan

Suzuki H.,Fukuoka University of Education | Yamamoto T.,Kanagawa Dental University
Tissue and Cell

In this study, we used immunohistochemical techniques to determine the cell type of leucine-enkephalin (Leu-ENK)-immunoreactive cells in the axolotl (Ambystoma mexicanum) pituitary. Immunoreactive cells were scattered throughout the pars distalis except for the dorso-caudal portion. These cells were immuno-positive for luteinizing hormone (LH), but they were immuno-negative for adrenocorticotrophic, growth, and thyroid-stimulating hormones, as well as prolactin. Immunoelectron microscopy demonstrated that Leu-ENK-like substance and LH co-localized within the same secretory granules. Leu-ENK secreted from gonadotrophs may participate in LH secretion in an autocrine fashion, and/or may participate in the release of sex steroids together with LH. © 2013 Elsevier Ltd. Source

Harrison A.,Bioventus | Lin S.,The New School | Pounder N.,Bioventus | Mikuni-Takagaki Y.,Kanagawa Dental University

It has been 30 years since the first level one clinical trial demonstrated low intensity pulsed ultrasound (LIPUS) could accelerate fracture repair. Since 1994 numerous investigations have been performed on the effect of LIPUS. The majority of these studies have used the same signal parameters comprised of an intensity of 30 mW/cm2 SATA, an ultrasound carrier frequency of 1.5 MHz, pulsed at 1 kHz with an exposure time of 20 minutes per day. These studies show that a biological response is stimulated in the cell which produces bioactive molecules. The production of these molecules, linked with observations demonstrating the enhanced effects on mineralization by LIPUS, might be considered the general manner, or mode, of how LIPUS stimulates fractures to heal. We propose a mechanism for how the LIPUS signal can enhance fracture repair by combining the findings of numerous studies. The LIPUS signal is transmitted through tissue to the bone, where cells translate this mechanical signal to a biochemical response via integrin mechano-receptors. The cells enhance the production of cyclo-oxygenese 2 (COX-2) which in turn stimulates molecules to enhance fracture repair. The aim of this review is to present the state of the art data related to LIPUS effects and mechanism. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license. Source

Suzuki H.,Fukuoka University of Education | Yamamoto T.,Kanagawa Dental University
Tissue and Cell

In this study, we investigated the presence of ovoid or ellipsoidal amylin-immunoreactive cells of the pancreatic islets of the black-spotted frog Rana (Pelophylax) nigromaculata. Using double immunofluorescent staining, all amylin-immunoreactive cells were shown to be immuno-negative for insulin, glucagon, and somatostatin, and they were often observed in peripheral regions of clusters of insulin-immunoreactive cells. Under immunoelectron microscopy, amylin-immunoreactive signals were detected on the secretory granules in a specific type of endocrine cells. From our results, we conclude that the amylin-immunoreactive cells correspond to X cells among the 4 distinct types of endocrine cells (B, A/PP, D, and X) previously identified in the frog. Amylin secreted from X cells may regulate the hormone secretion from A/PP cells and/or B cells through a paracrine mechanism. © 2014 Elsevier Ltd. Source

Hara N.,Kanagawa Dental University
Neuro-Ophthalmology Japan

Pupillary constriction, accommodation and vergence play an extremely important role in perception of three-dimensional space, such as the sense of depth and binocular vision, and in control of visual alignment, such as convergence. Visual information (e.g., disparity, blur, and size) converges in higher brain function areas. The signal for executing motions is efficiently formed in the frontal lobe and brainstem, resulting in near responses, such as convergence movement and focusing. Moreover, a parallel circuit of the vestibulo-cerebellar system plays a role in adaptive learning control, which is important for optimization of both movements and maintenance of the eye positions, to produce elaborate near responses. We consider that vulnerability or damage of the neural circuit/mechanism controlling these near responses is one of the causes of exotropia. Based on the analysis of pupillary constriction during near responses, we also demonstrate that the pathological condition of intermittent exotropia is an excessively prolonged, abnormal near response impairment. We then describe how surgery for strabismus markedly improves near response impairments induced by three-dimensional video stimuli. In this way, we describe the "etiology of exotropia" in terms of the neuro-ophthalmology/physiology of near responses, including a review of the relevant literature and examination of our own data. Source

The aim of the present study was to determine whether occlusal hypofunction and its recovery affected the structure of the Periodontal Ligament (PDL) and expression of Vascular Endothelial Growth Factor (VEGF) in mice. Five-week-old C57BL/6J mice (Jackson Laboratory, Bar Harbor ME, USA) were used and randomly divided into three groups: a Hypofunctional Group (HG), Recovery Group (RG), and Control Group (CG). In HG and RG, appliances were attached to the maxillary and mandibular incisors. These appliances were set for 11 weeks in HG and 7 weeks in RG. Appliances were then removed offer 0, 7, 14, and 28 days. Untreated mice served as CG. Histological sections were prepared and immunohistochemically stained for VEGF. The PDL area and the number of VEGF immunopositive cells in the PDL were evaluated in the 3 groups. The number of VEGF immunopositive cells and PDL area were significantly larger in CG white the RG than in HG, while the PDL area in RG was similar to that in CG. In the recovery process, the PDL area and number of VEGF positive cells in the PDL increased from days 0 to 7 and decreased from days 7 to 28. The results of the present study suggest that occlusal stimuli regulate the PDL area through the expression of VEGF in the mouse PDL. The clinical relevance of occlusal stimuli is their ability to regulate the expression of VEGF in PDL cells and these growth factors may lead to alveolar bone remodeling in the PDL. © 2016, Scientific Publishers of India. All rights reserved. Source

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