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García-García ÓD, El Soury M, González-Quevedo D, Sánchez-Porras D, Chato-Astrain J, Campos F, Carriel V. Histological, Biomechanical, and Biological Properties of Genipin-Crosslinked Decellularized Peripheral Nerves. Int J Mol Sci 2021; 22:ijms22020674. [PMID: 33445493 PMCID: PMC7826762 DOI: 10.3390/ijms22020674] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 02/07/2023] Open
Abstract
Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.
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Affiliation(s)
- Óscar Darío García-García
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Instituto de Investigación Biosanitaria ibs. GRANADA, 18012 Granada, Spain
- Doctoral Program in Biomedicine, University of Granada, 18012 Granada, Spain
| | - Marwa El Soury
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Department of Clinical and Biological Sciences and Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Torino, 10043 Orbassano, Italy
| | - David González-Quevedo
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Department of Orthopedic Surgery and Traumatology, Regional University Hospital of Málaga, 29010 Málaga, Spain
| | - David Sánchez-Porras
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Instituto de Investigación Biosanitaria ibs. GRANADA, 18012 Granada, Spain
| | - Jesús Chato-Astrain
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Instituto de Investigación Biosanitaria ibs. GRANADA, 18012 Granada, Spain
| | - Fernando Campos
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Instituto de Investigación Biosanitaria ibs. GRANADA, 18012 Granada, Spain
- Correspondence: (F.C.); (V.C.)
| | - Víctor Carriel
- Tissue Engineering Group, Department of Histology, University of Granada, 18016 Granada, Spain; (Ó.D.G.-G.); (M.E.S.); (D.G.-Q.); (D.S.-P.); (J.C.-A.)
- Instituto de Investigación Biosanitaria ibs. GRANADA, 18012 Granada, Spain
- Correspondence: (F.C.); (V.C.)
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Bogovic JA, Otsuna H, Heinrich L, Ito M, Jeter J, Meissner G, Nern A, Colonell J, Malkesman O, Ito K, Saalfeld S. An unbiased template of the Drosophila brain and ventral nerve cord. PLoS One 2020; 15:e0236495. [PMID: 33382698 PMCID: PMC7774840 DOI: 10.1371/journal.pone.0236495] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 07/07/2020] [Indexed: 12/03/2022] Open
Abstract
The fruit fly Drosophila melanogaster is an important model organism for neuroscience with a wide array of genetic tools that enable the mapping of individual neurons and neural subtypes. Brain templates are essential for comparative biological studies because they enable analyzing many individuals in a common reference space. Several central brain templates exist for Drosophila, but every one is either biased, uses sub-optimal tissue preparation, is imaged at low resolution, or does not account for artifacts. No publicly available Drosophila ventral nerve cord template currently exists. In this work, we created high-resolution templates of the Drosophila brain and ventral nerve cord using the best-available technologies for imaging, artifact correction, stitching, and template construction using groupwise registration. We evaluated our central brain template against the four most competitive, publicly available brain templates and demonstrate that ours enables more accurate registration with fewer local deformations in shorter time.
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Affiliation(s)
- John A. Bogovic
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Hideo Otsuna
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Larissa Heinrich
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Masayoshi Ito
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Jennifer Jeter
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Geoffrey Meissner
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Aljoscha Nern
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Jennifer Colonell
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Oz Malkesman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Kei Ito
- Institute of Zoology, University of Cologne, Germany
| | - Stephan Saalfeld
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
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Worsaae K, Rimskaya-Korsakova NN, Rouse GW. Neural reconstruction of bone-eating Osedax spp. (Annelida) and evolution of the siboglinid nervous system. BMC Evol Biol 2016; 16:83. [PMID: 27080383 PMCID: PMC4832464 DOI: 10.1186/s12862-016-0639-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 03/20/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bone-devouring Osedax worms were described over a decade ago from deep-sea whale falls. The gutless females (and in one species also the males) have a unique root system that penetrates the bone and nourishes them via endosymbiotic bacteria. Emerging from the bone is a cylindrical trunk, which is enclosed in a transparent tube, that generally gives rise to a plume of four palps (or tentacles). In most Osedax species, dwarf males gather in harems along the female's trunk and the nervous system of these microscopic forms has been described in detail. Here, the nervous system of bone-eating Osedax forms are described for the first time, allowing for hypotheses on how the abberant ventral brain and nervous system of Siboglinidae may have evolved from a ganglionated nervous system with a dorsal brain, as seen in most extant annelids. RESULTS The intraepidermal nervous systems of four female Osedax spp. and the bone-eating O. priapus male were reconstructed in detail by a combination of immunocytochemistry, CLSM, histology and TEM. They all showed a simple nervous system composed of an anterior ventral brain, connected with anteriorly directed paired palp and gonoduct nerves, and four main pairs of posteriorly directed longitudinal nerves (2 ventral, 2 ventrolateral, 2 sets of dorso-lateral, 2 dorsal). Transverse peripheral nerves surround the trunk, ovisac and root system. The nervous system of Osedax resembles that of other siboglinids, though possibly presenting additional lateral and dorsal longitudinal nerves. It differs from most Sedentaria in the presence of an intraepidermal ventral brain, rather than a subepidermal dorsal brain, and by having an intraepidermal nerve cord with several plexi and up to three main commissures along the elongated trunk, which may comprise two indistinct segments. CONCLUSIONS Osedax shows closer neuroarchitectural resemblance to Vestimentifera + Sclerolinum (= Monilifera) than to Frenulata. The intraepidermal nervous system with widely separated nerve cords, double brain commissures, double palp nerves and other traits found in Osedax can all be traced to represent ancestral states of Siboglinidae. A broader comparison of the nervous system and body regions across Osedax and other siboglinids allows for a reinterpretation of the anterior body region in the group.
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Affiliation(s)
- Katrine Worsaae
- />Marine Biological Section, Department of Biology, University of Copenhagen, Universitetsparken 4, DK-2100 Copenhagen, Denmark
| | | | - Greg W. Rouse
- />Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, California 92093-0202 USA
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Nguyen KV, Li JR, Radecki G, Ciobanu L. DLA based compressed sensing for high resolution MR microscopy of neuronal tissue. J Magn Reson 2015; 259:186-191. [PMID: 26367320 DOI: 10.1016/j.jmr.2015.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 06/05/2023]
Abstract
In this work we present the implementation of compressed sensing (CS) on a high field preclinical scanner (17.2 T) using an undersampling trajectory based on the diffusion limited aggregation (DLA) random growth model. When applied to a library of images this approach performs better than the traditional undersampling based on the polynomial probability density function. In addition, we show that the method is applicable to imaging live neuronal tissues, allowing significantly shorter acquisition times while maintaining the image quality necessary for identifying the majority of neurons via an automatic cell segmentation algorithm.
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Affiliation(s)
- Khieu-Van Nguyen
- Neurospin, CEA Saclay, 91191 Gif sur Yvette, France; University Paris-Sud, XI, 91450 Orsay, France
| | - Jing-Rebecca Li
- INRIA-Saclay, Equipe DEFI, CMAP, Ecole Polytechnique, 91128 Palaiseau, France
| | | | - Luisa Ciobanu
- Neurospin, CEA Saclay, 91191 Gif sur Yvette, France.
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Abstract
The invention of the microscope at the beginning of the seventeenth century was a pivotal event for subsequent studies of the microscopic structure of nerve tissue. The present article, using translations of the original texts, presents a recollection of the discoveries made during the second half of the seventeenth century up to the beginning of the nineteenth century by prominent scholars as well as those nearly forgotten today. The findings in the field of neuroanatomy are collected together into a coherent form and in chronological order, showing the progress of the discoveries from a historical perspective. The early scientists discovered, and then repeatedly confirmed, that nerve tissue was remarkably similar over a wide range of animal forms. While they offered little detail, and much of what was described was flawed because of various technical restraints of the time, what they did report was very similar from animal to animal. Their studies, however, in parallel with the improvement of microscopic techniques as well as the processing and fixation of animal tissues, helped to create fertile ground for a number of important neurohistological discoveries in the first half of the nineteenth century.
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Affiliation(s)
- Alexandr Chvátal
- a Department of Cellular Neurophysiology , Institute of Experimental Medicine, Academy of Sciences of the Czech Republic , Prague , Czech Republic
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Abstract
BACKGROUND This study evaluated whether Schwann-like cells (SLCs) induced from bone marrow-derived mesenchymal stem cells (BM-MSCs) transplanted into acellular nerve grafts (ANGs) could repair nerve defects compared with nerve isografts and ANGs with BM-MSCs. METHODS BM-MSCs extracted, separated and purified from the bone marrow of rats, and some of the BM-MSCs were cultured with mixed induction agents that could induce BM-MSCs into SLCs. Either SLCs or BM-MSCs were seeded onto 10-mm ANGs, and the isografts were chosen as the control. The walking-track test, tibialis anterior muscle weight measurement, electrophysiological examination, toluidine blue staining, transmission electron micrographs and immunostaining of S-100 and VEGF in these three groups were evaluated in a 10-mm rat sciatic injury-repair model. RESULTS The walking-track test, tibialis anterior muscle weight measurement and electrophysiological examination of the sciatic nerve suggested the groups of ANGs with SLCs and isografts obtained better results than the BM-MSC group (P<0.05). Meanwhile, the results of the SLCs and isograft groups were similar (P>0.05). All the histomorphometric analyses (toluidine blue staining, transmission electron micrographs and immunostaining of S-100 and VEGF) showed that there were more regenerating nerve fibers in the group of ANGs with SLCs than the BM-MSCs (P<0.05), but there was no significant difference between the SLC and isograft groups (P>0.05). CONCLUSIONS SLCs seeded in ANGs and isografts show better functional regeneration compared with BM-MSCs seeded in ANGs. Additionally, SLCs combined with ANGs present almost the same outcome as the isografts. Therefore, SLCs with ANGs can be a good choice in nerve defect repairs.
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Affiliation(s)
- Lihong Fan
- The first department of Orthopedics, the Second Affilliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an, Shaanxi Province 710004, China
| | - Zefeng Yu
- The first department of Orthopedics, the Second Affilliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an, Shaanxi Province 710004, China
| | - Jia Li
- The first department of Orthopedics, the Second Affilliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an, Shaanxi Province 710004, China
| | - Xiaoqian Dang
- The first department of Orthopedics, the Second Affilliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an, Shaanxi Province 710004, China
| | - Kunzheng Wang
- The first department of Orthopedics, the Second Affilliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an, Shaanxi Province 710004, China
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Manolea H, Vasile N, Opri M, Fronie A, Popescu MR. Immunohistochemical and electron microscopy aspects of the nerve structures from the dental pulp. Rom J Morphol Embryol 2014; 55:147-152. [PMID: 24715180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this study, we have done an immunohistochemical and an electron microscopy examination of normal and inflamed human dental pulp specimens in order to evaluate the morphological aspects of the nerve structures from the dental pulp. The S100 protein immunohistochemical marking allowed us to observe the trajectory of the pulp nervous structures, which appear as continuous bands of high intensity at radicular level, coronary branch out and some branches cross the odontoblastic layer and penetrate in predentin along the dentinal tubules. It appears that not only the nerve structures are positive S100 protein but also macrophages or dendritic cells. The electron microscopic part presents the ultrastructure details of the nervous structures observed on the samples from normal and inflamed pulp conjunctive tissues. Even in acute pulpitis no ultrastructural changes occur in the nerve fibers, prolonged exposure to noxious factors may lead to changes like nerve sprouting.
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Affiliation(s)
- Horia Manolea
- Department of Dental Materials, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, Romania;
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Wang Y, Zhao Z, Zhao B, Qi HX, Peng J, Zhang L, Xu WJ, Hu P, Lu SB. Biocompatibility evaluation of electrospun aligned poly (propylene carbonate) nanofibrous scaffolds with peripheral nerve tissues and cells in vitro. Chin Med J (Engl) 2011; 124:2361-2366. [PMID: 21933569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND Peripheral nerve regeneration across large gaps is clinically challenging. Scaffold design plays a pivotal role in nerve tissue engineering. Recently, nanofibrous scaffolds have proven a suitable environment for cell attachment and proliferation due to similarities of their physical properties to natural extracellular matrix. Poly(propylene carbonate) (PPC) nanofibrous scaffolds have been investigated for vascular tissue engineering. However, no reports exist of PPC nanofibrous scaffolds for nerve tissue engineering. This study aimed to evaluate the potential role of aligned and random PPC nanofibrous scaffolds as substrates for peripheral nerve tissue and cells in nerve tissue engineering. METHODS Aligned and random PPC nanofibrous scaffolds were fabricated by electrospinning and their chemical characterization were carried out using scanning electron microscopy (SEM). Dorsal root ganglia (DRG) from Sprague-Dawley rats were cultured on the nanofibrous substrates for 7 days. Neurite outgrowth and Schwann-cell migration from DRG were observed and quantified using immunocytochemistry and SEM. Schwann cells derived from rat sciatic nerves were cultured in electrospun PPC scaffold-extract fluid for 24, 48, 72 hours and 7 days. The viability of Schwann cells was evaluated by 3-[4,5-dimethyl(thiazol-2-yl)-2,5-diphenyl] tetrazolium bromide (MTT) assay. RESULTS The diameter of aligned and random fibers ranged between 800 nm and 1200 nm, and the thickness of the films was approximately 10 - 20 µm. Quantification of aligned fiber films revealed approximately 90% alignment of all fibers along the longitudinal axis. However, with random fiber films, the alignment of fibers was random through all angle bins. Rat DRG explants were grown on PPC nanofiber films for up to 1 week. On the aligned fiber films, the majority of neurite outgrowth and Schwann cell migration from the DRG extended unidirectionally, parallel to the aligned fibers. However, on the random fiber films, neurite outgrowth and Schwann cell migration were randomly distributed. A comparison of cumulative neurite lengths from cultured DRGs indicated that neurites grew faster on aligned PPC films ((2537.6 ± 987.3) µm) than randomly-distributed fibers ((493.5 ± 50.6) µm). The average distance of Schwann cell migration on aligned PPC nanofibrous films ((2803.5 ± 943.6) µm) were significantly greater than those on random fibers ((625.3 ± 47.8) µm). The viability of Schwann cells cultured in aligned PPC scaffold extract fluid was not significantly different from that in the plain DMEM/F12 medium at all time points after seeding. CONCLUSIONS The aligned PPC nanofibrous film, but not the randomly-oriented fibers, significantly enhanced peripheral nerve regeneration in vitro, indicating the substantial role of topographical cues in stimulating endogenous nerve repair mechanisms. Aligned PPC nanofibrous scaffolds may be a promising biomaterial for nerve regeneration.
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Affiliation(s)
- Yu Wang
- Orthopedics Research Institute of Chinese People's Liberation Army, Chinese People's Liberation Army General Hospital, Beijing 100853, China
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Trinajstic K, Marshall C, Long J, Bifield K. Exceptional preservation of nerve and muscle tissues in Late Devonian placoderm fish and their evolutionary implications. Biol Lett 2008; 3:197-200. [PMID: 17284403 PMCID: PMC2375963 DOI: 10.1098/rsbl.2006.0604] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In this paper, we show exceptional three-dimensionally preserved fossilized muscle tissues in 380-384 Myr old placoderm fish (Late Devonian), offering new morphological evidence supporting the hypothesis that placoderms are the sister group to all other gnathostomes. We describe the oldest soft tissue discovered in gnathostomes, which includes striated muscle fibres, circulatory and nerve tissues, preserved as phosphatized structures precipitated by microbial infilling of small, protected areas under the headshield of the arthrodire, Eastmanosteus calliaspis. Muscle impressions have also been found in the ptyctodontid, Austroptyctodus gardineri. The specimens display primitive vertebrate muscle structures; in particular, shallow W-shaped muscle blocks such as those observed in lampreys. New information from fossilized soft tissues thus elucidates the affinities of the placoderms and provides new insights into the evolution and radiation of gnathostomes.
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Affiliation(s)
- Kate Trinajstic
- School of Earth and Geographical Sciences, University of Western Australia, Perth, Western Australia 6009, Australia.
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Li GN, Livi LL, Gourd CM, Deweerd ES, Hoffman-Kim D. Genomic and morphological changes of neuroblastoma cells in response to three-dimensional matrices. ACTA ACUST UNITED AC 2007; 13:1035-47. [PMID: 17439391 DOI: 10.1089/ten.2006.0251] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Advances in neural tissue engineering require a comprehensive understanding of neuronal growth in 3 dimensions. This study compared the gene expression of SH-SY5Y human neuroblastoma cells cultured in 3-dimensional (3D) with those cultured in 2-dimensional (2D) environments. Microarray analysis demonstrated that, in response to varying matrix geometry, SH-SY5Y cells exhibited differential expression of 1,766 genes in collagen I, including those relevant to cytoskeleton, extracellular matrix, and neurite outgrowth. Cells extended longer neurites in 3D collagen I cultures than in 2D. Real-time reverse transcriptase polymerase chain reaction experiments and morphological analysis comparing collagen I and Matrigel tested whether the differential growth and gene expression reflected influences of culture dimension or culture material. SH-SY5Y neuroblastoma cells responded to geometry by differentially regulating cell spreading and genes associated with actin in similar patterns for both materials; however, neurite outgrowth and the expression of the gene encoding for neurofilament varied with the type of material. Electron microscopy and mechanical analysis showed that collagen I was more fibrillar than Matrigel, with larger inter-fiber distance and higher stiffness. Taken together, these results suggest complex cell-material interactions, in which the dimension of the culture material influences gene expression and cell spreading and the structural and mechanical properties of the culture material influence gene expression and neurite outgrowth.
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Affiliation(s)
- Grace N Li
- Center for Biomedical Engineering, Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island 02912, USA
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Abstract
This study investigated relationships between a microscale neural probe's size and shape and its chronic reactive tissue response. Parylene-based probes were microfabricated with a thick shank (48 microm by 68 microm) and an integrated thin lateral platform (5 microm by 100 microm, either solid or one of three lattice sizes). Devices were implanted in rat cerebral cortex for 4 weeks before immunostaining for neurons, astrocytes, microglia, fibronectin, laminin, and neurofilament. While nonneuronal density (NND) generally increased and neuronal density decreased within 75 microm of a probe interface compared to unimplanted control regions, there were significant differential tissue responses within 25 microm of the platform's lateral edge compared to the shank. The NND in this region of the lateral edge was less than one-third of the corresponding region of the shank (129% and 425% increase, respectively). Moreover, neuronal density around the platform lateral edge was about one-third higher than at the shank (0.70 and 0.52 relative to control, respectively). Also, microglia reactivity and extracellular protein deposition was reduced at the lateral edge. There were no significant differences among platform designs. These results suggest that neural probe geometry is an important parameter for reducing chronic tissue encapsulation.
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Affiliation(s)
- John P Seymour
- Department of Biomedical Engineering, University of Michigan, 2212 Lurie Biomedical Engineering Building, 1101 Beal Avenue, Ann Arbor, MI 48109-2099, USA
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Shany B, Peretz H, Blinder P, Lichtenfeld Y, Jeger R, Vago R, Baranes D. Aragonite Crystalline Biomatrices Support Astrocytic Tissue Formationin Vitroandin Vivo. ACTA ACUST UNITED AC 2006; 12:1763-73. [PMID: 16889507 DOI: 10.1089/ten.2006.12.1763] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Astrocytes play a pivotal role in the development and function of the central nervous system by regulating synaptic activity and supporting and guiding growing axons. It is therefore a central therapeutic and scientific challenge to develop means to control astrocytic survival and growth. We cultured primary hippocampal astrocytes on a crystalline three-dimensional (3D) aragonite biomatrix prepared from the exoskeleton of the coral Porites lutea. Such culturing led to the formation of astrocytic tissue-like 3D structures in which the cells had a higher survival rate than astrocytes grown in conventional cell culture. Within the pore void areas, multiple layers of astrocytic processes formed concave sheet structures that had no physical contact with the surface. The astrocytes attached to the crystalline perpendicular edges of the crystalline template surface extended processes in 3D and expressed glial fibrillary acidic protein. The astrocytes also expressed gap junctions and developed partly synchronized cytosolic Ca2+ oscillations. Preliminary in vivo models showed that astrocytic networks were also developed when the matrices were implanted into cortical areas of postnatal rat brains. Hence, we suggest that the biomatrix is a biocompatible supportive scaffold for astrocytes and may be exploited in applications for neuronal tissue restoration in injured or diseased central nervous system.
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Affiliation(s)
- B Shany
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
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Altelaar AFM, van Minnen J, Jiménez CR, Heeren RMA, Piersma SR. Direct Molecular Imaging ofLymnaea stagnalisNervous Tissue at Subcellular Spatial Resolution by Mass Spectrometry. Anal Chem 2005; 77:735-41. [PMID: 15679338 DOI: 10.1021/ac048329g] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The imaging capabilities of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and MALDI-MS sample preparation methods were combined. We used this method, named matrix-enhanced (ME) SIMS, for direct molecular imaging of nervous tissue at micrometer spatial resolution. Cryosections of the cerebral ganglia of the freshwater snail Lymnaea stagnalis were placed on indium-tin-oxide (ITO)-coated conductive glass slides and covered with a thin layer of 2,5-dihydroxybenzoic acid by electrospray deposition. High-resolution molecular ion maps of cholesterol and the neuropeptide APGWamide were constructed. APGWamide was predominantly localized in the cluster of neurons that regulate male copulation behavior of Lymnaea. ME-SIMS imaging allows direct molecule-specific imaging from tissue sections without labeling and opens a complementary mass window (<2500 Da) to MALDI imaging mass spectrometry at an order of magnitude higher spatial resolution (<3 microm).
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Affiliation(s)
- A F Maarten Altelaar
- FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands
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Shubich MG, Ermoshenko BG, Perov IM, Dorofeeva IV. [Gap junctions--major structures promoting intercellular communication]. Morfologiia 2005; 127:65-71. [PMID: 16080356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Gap junctions provide humoral and electric communication between the cells, thus contributing to their morpho-functional cooperation. Gap junction is formed by multiple intercellular channels, each of them being made by two closed hemichannels--connexons, that are oligomeric transmembrane proteins built by 6 subunits, belonging to connexin family. Permeability and electric conductivity of gap junction channels is determined by molecular peculiarities of connexins, their capacity for phosphorilation and by some extra- and intracellular factors. According to the current data, gap junctions in both cell cultures and tissues are dynamic structures with a short half-life period. Main mechanisms responsible for gap junction assembly and destruction have been discovered. These mechanisms were shown to depend upon peculiarities of differential genome activity and to be controlled by extra- and intracellular factors. The data on the gap junctions in the nervous system, heart and epidermis are presented.
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Kohout A. [Nervous component of mature cystic ovarian teratomas]. Cesk Patol 2005; 41:19-28. [PMID: 15816120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In 30-50 percent of cases mature cystic ovarian teratomas contain a nervous tissue which can be highly differentiated. This study was focused on research of the nervous component of mature cystic ovarian teratomas with generally available methods to pathologists, including impregnation techniques, immunohistochemistry and electron microscopy. From the total number of 212 mature cystic ovarian teratomas, the nervous tissue was found in 72 cases (34%), which corresponds to the literature data. According to its differentiation, it was possible to distinguish five categories of nervous tissue by light microscopy: 0 peripheral nervous tissue only, 1--solid glial nodules, 2--glial cysts, 3--glial tissue with abundant scattered neurons and, finally, 4--organoid nervous tissue similar to certain CNS structures. Apart from the foci similar to grey matter of the spinal cord and cerebral cortex, those of differentiated cerebellar cortex were present as well. Astrocytes mostly predominated in the nervous tissue, and they sometimes showed reactive changes including gemistocytes and formation of Rosenthal fibres. Neuronal elements also showed degenerative changes quite frequently, especially in a less differentiated nervous component. These changes might have developed due to an abnormal location of the nervous tissue or its hypoxia in the teratoma. Contrary to some literature data, oligodendrocytes and myelin were present in the nervous tissue of most of our cases. Ultrastructurally, neurons with fully developed synapses were observed in the nervous component, and dendritic spines were present on dendrites of Purkinje cells of cerebellar cortex. The results obtained from the examination of teratomas in this study confirmed and enriched the literature data concerning the high degree of differentiation of their nervous components. We suggest that the differentiated nervous tissue of teratoma represents a unique natural model suitable for research of some aspects of neurohistology and neuropathology, e.g. synaptogenesis or myelinogenesis.
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Affiliation(s)
- A Kohout
- Fingerlandův śtav patologie Lékarské fakulty UK a Fakultní nemocnice, Hradec Králové.
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16
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Fonseca DB, Sheehy MRJ, Blackman N, Shelton PMJ, Prior AE. Reversal of a hallmark of brain ageing: lipofuscin accumulation. Neurobiol Aging 2005; 26:69-76. [PMID: 15585347 DOI: 10.1016/j.neurobiolaging.2004.02.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Revised: 01/15/2004] [Accepted: 02/24/2004] [Indexed: 10/26/2022]
Abstract
The prospect of removing cellular deposits of lipofuscin is of considerable interest because they may contribute to age related functional decline and disease. Here, we use a decapod crustacean model to circumvent a number of problems inherent in previous studies on lipofuscin loss. We employ (a) validated lipofuscin quantification methods, (b) an in vivo context, (c) essentially natural environmental conditions and (d) a situation without accelerated production of residual material or (e) application of pharmacological compounds. We use a novel CNS biopsy technique that produces both an anti-ageing effect and also permits longitudinal sampling of individuals, thus (f) avoiding conventional purely cross-sectional population data that may suffer from selective mortality biases. We quantitatively demonstrate that lipofuscin, accrued through normal ageing, can be lost from neural tissue. The mechanism of loss probably involves exocytosis and possibly blood transport. If non-disruptive ways to accelerate lipofuscin removal can be found, our results suggest that therapeutic reversal of this most universal manifestation of cellular ageing may be possible.
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Affiliation(s)
- D B Fonseca
- Department of Biology, University of Leicester, University Road, Leicester LE1 7RH, UK.
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17
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Pinto LZ, Laure MAFB, Bitondi MMG, Hartfelder K, Simões ZLP. Ventral nerve cord remodeling in a stingless bee (Melipona quadrifasciata anthidioides, Hymenoptera, Apidae) depends on ecdysteroid fluctuation and programmed cell death. Int J Dev Biol 2003; 47:385-8. [PMID: 12895033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
The reorganization of the ventral nerve cord (VNC) during metamorphosis of M. quadrifasciata was observed to be characterized by shortening of connectives and subsequent fusion of the 2nd and 3rd thoracic and the 1st abdominal ganglia. Also, the 5th to 7th abdominal ganglia came into very close contact. These changes were accompanied by increasing levels of endogenous ecdysteroids, as determined by a radioimmunoassay. Incubation of VNC in the presence of 5 microg 20-hydroxyecdysone, caused significant shortening of connectives in the thoracic region, but not in the abdomen, evidencing a segment-specific response to this hormone. Cell death in the ventral ganglia was revealed by transmission electron microscopy and TUNEL-reaction. Detection of labeled cells in the region where contiguous ganglia come into close contact suggests that programmed cell death is involved in ganglionic fusion.
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Affiliation(s)
- Lucimara Z Pinto
- Departamento de Genética, FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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18
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Sukhanov AV, Vakulin GM. [Modification of the Bilshovsky method for studies of nerve tissue paraffin sections]. Klin Lab Diagn 2002:42-3. [PMID: 11899533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The Bilshovsky method is often used for studies of the morphology of neuronal fibrillar system. The classical variant of this method requires sections made with a freezing microtome, which is sometimes inconvenient. Preparation of paraffin sections often gives unsatisfactory results. The authors managed to overcome this deficiency. Their modification consists in the following: after deparaffinization of paraffin sections glued to the slides they are repeatedly fixed in warm formalin and then treated with silver nitrate with heating. This modification is easily reproducible and essentially simplifies staining; no freezing microtome is needed.
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19
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González-Elorriaga MA, Canepa G. [Suggestive evidences for a microanatomical relationship between mast cells and nerve in the tongue of the toad Bufo marinus demonstrated by means of high resolution light microscopy]. Acta Cient Venez 2002; 53:258-65. [PMID: 12945491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
Mast cells are connective tissue cells, present in all vertebrates and characterized by the metachromatic stain of their granules. Nowadays mast cells have been recognized as a potent cellular source of multiple cytokines, suggesting an important role in immunoregulation and host defense. These cells have been described as preferentially located around blood vessels but more recently close spatial relationship between mast cells and nerves has been reported mostly in mammalian species. The microanatomy of nerve tissue and associated mast cells in the toad Bufo marinus tongue have been studied here by means of high resolution light microscopy. Mast cell population was identified by the metachromatic staining of their cytoplasm granules in Epon embedded semithin sections counterstained with Toluidine Blue and Azure A. Numerous mast cells were observed scattered throughout the submucosal region, adjacent and/or within of nerve bundles and nerve ganglia, near skeletal muscle fibers and adjacent of blood vessels. Additionally, mast cells adjacent to single but conspicuous myelinated nerve fibers were seen under endothelia of lymphatic vessels wall and this is apparently a unreported event. Results suggest nerve-mast cell associations are functionally important in the toad tongue.
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Abstract
Evaluation of electron microscopic images of serial sections is a time-consuming process requiring a high level of expertise. Here we present an algorithm to ease and accelerate this process. It is a modification of an algorithm successfully used in computer vision for object recognition. However, rather than recognising individual structures, we estimate the spatial mapping of a whole section onto the consecutive one. This mapping is used to transfer labelled information of the very first section, e.g. a classification by a human expert of different visible structures, onto structures visible in the next section. We investigate its performance on an artificially constructed benchmark as well as on real electron microscopic samples taken in primary visual cortex and demonstrate its potential for dramatically facilitating the evaluation process of serial sections.
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Affiliation(s)
- P König
- Institute of Neuroinformatics, ETH/University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
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21
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Vital A, Ferrer X, Lagueny A, Vandenberghe A, Latour P, Goizet C, Canron MH, Louiset P, Petry KG, Vital C. Histopathological features of X-linked Charcot-Marie-Tooth disease in 8 patients from 6 families with different connexin32 mutations. J Peripher Nerv Syst 2001; 6:79-84. [PMID: 11446387 DOI: 10.1046/j.1529-8027.2001.01011.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is still confusion as to whether X-linked Charcot-Marie-Tooth disease (CMTX) is primarily an axonal disorder or is primarily demyelinating. Eight symptomatic patients, 7 males and 1 female, from 6 families with identified connexin32 mutations underwent a superficial peroneal nerve biopsy. Quantitative and ultrastructural studies were performed, and histopathological lesions in these 8 patients proved to be quite homogeneous. The myelinated fiber count was within normal values or only moderately decreased. In 7 cases, the distribution of myelinated fibers was unimodal due to a loss of large fibers, coexisting with numerous clusters of small regenerating fibers. At ultrastructural level, these clusters were often surrounded by flattened Schwann cell processes giving an aspect of "pseudo-onion bulb" formation. There was no "naked axon" (ie, demyelinated axon), and real "onion bulb" formations composed of flattened Schwann cell processes surrounding an isolated myelinated fiber were discrete and not numerous. Macrophages laden with myelin debris were scarce or absent in the endoneurium. Several fibers appeared discretely hypomyelinated and the calculated g-ratio was scarcely higher than the mean control value. Lesions of unmyelinated fibers were absent in 7 cases and mild in one. Given that the primary defect concerns connexin32, we think that the histopathological features observed in our patients correspond to primary hypomyelination rather than to ongoing demyelination. The associated axonal degeneration might be secondary to defective axon-Schwann cell interactions.
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Affiliation(s)
- A Vital
- Département de Neuropathologie, Université Victor Ségalen-Bordeaux 2, France.
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22
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Franchi A, Pasquinelli G, Cenacchi G, Della Rocca C, Gambini C, Bisceglia M, Martinelli GN, Santucci M. Immunohistochemical and ultrastructural investigation of neural differentiation in Ewing sarcoma/PNET of bone and soft tissues. Ultrastruct Pathol 2001; 25:219-25. [PMID: 11465478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The authors evaluated the role of immunohistochemistry and electron microscopy in defining neural differentiation in 28 cases of Ewing sarcoma/PNET. The panel of primary antibodies used included vimentin, MIC-2, NSE, S-100 protein, leu7, neurofilaments, GFAP, and chromogranin A. Cases were considered undifferentiated when neural markers were absent, poorly differentiated if one neural marker was present, and well differentiated if two or more markers were observed. Cases were also evaluated for the presence of cytoplasmic processes, microtubules, and neurosecretory granules as ultrastructural features of neural differentiation: the tumor was classified as well differentiated if two of these features were present; and poorly differentiated if one was evident; all other cases were considered undifferentiated. According to immunohistochemistry, 10 cases (35.7%) were undifferentiated, 12 cases (42.9%) were poorly differentiated, and 6 (21.4%) were well differentiated. According to the ultrastructural analysis, 10 tumors were undifferentiated (35.7%), 14 poorly differentiated (50%), and 4 well differentiated (14.3%). The overall concordance between the two techniques was low (35.7%), and both modalities were concordant in classifying only 1 well-differentiated, 5 poorly differentiated, and 4 undifferentiated tumors. In conclusion, the authors suggest that investigations devoted to test the prognostic significance of neural differentiation in these neoplasms should employ both immunohistochemistry and electron microscopy, separately and in combination, to assess what is the most effective choice for predicting the clinical course.
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Affiliation(s)
- A Franchi
- Dipartimento di Patologia Umana ed Oncologia, Università degli Studi de Firenze, Italy
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23
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Abstract
We investigated the muscular structure and innervation of the gastroduodenal junction in the guinea pig. In the gastroduodenal junction, the innermost layer of the circular muscle contained numerous nerve fibers and terminals. Since this nerve network continued onto the deep muscular plexus (DMP) of the duodenum, we surmised that the numerous nerve fibers in the gastroduodenal junction were specialized DMP in the most proximal part of the duodenum. The innermost layer containing many nerve fibers was about 1,000 microm in length and 100 microm in thickness in the proximal duodenum. This layer contained numerous connective tissue fibers composed of collagen and elastic fibers. Five to 30 smooth muscle cells lay in contact with each other and were surrounded by fine connective tissue. The nerve fibers in the proximal duodenum contained nerve terminals immunoreactive for choline acetyltransferase, dynorphin, enkephalin, galanin, gastrin-releasing peptide, nitric oxide synthase, substance P, and vasoactive intestinal polypeptide. Adrenergic fibers which contained tyrosine hydroxylase immunoreactivity were rare in the proximal duodenum. In the innermost layer of the proximal duodenum, there were numerous c-Kit immunopositive cells that were in contact with nerve terminals. This study allowed us to clarify the specific architecture of the most proximal portion of the duodenum. The functional significance of the proximal duodenum in relation to the electrical connection and neural cooperation of the musculature between the antrum and the duodenum is also discussed.
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Affiliation(s)
- S Iino
- Department of Anatomy, Fukui Medical University, Matsuoka, Japan.
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24
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Abstract
The transmissible spongiform encephalopathies (TSE) or prion diseases are fatal neurodegenerative disorders in which the central event is the conversion of a normal host-encoded protein (PrP(c)) into an abnormal isoform (PrP(sc)) which accumulates as amyloid in TSE brain. The two PrP(c) and PrP(sc) prion protein isoforms are membrane sialoglycoproteins synthesized in the central nervous system and various peripheral organ tissues. In this review, we describe the ultrastructural localization of prion proteins in human and animal cerebral and non-cerebral tissues whether or not infected by TSE agents. In addition to the plasma membrane of several cells, PrP(c) was found in association with cytoplasmic organelles of central and nerve-muscle synapses, and secretory granules of epithelial cells. Fibrils of amyloid plaques, synaptic structures, and lysosome-like organelles constitute the subcellular sites harboring PrP(sc). These findings have led to discussions on the physiological role of PrP(c) and the pathological mechanisms underlying prion spongiform encephalopathies.
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Affiliation(s)
- J G Fournier
- Service de Neurovirologie, CEA, DSV/DRM, BP6, 92265 Fontenay-aux-Roses Cedex, France.
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25
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Sugimura I, Adachi-Yamada T, Nishi Y, Nishida Y. A Drosophila Winged-helix nude (Whn)-like transcription factor with essential functions throughout development. Dev Growth Differ 2000; 42:237-48. [PMID: 10910130 DOI: 10.1046/j.1440-169x.2000.00509.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A Drosophila gene, Dwhn (Drosophila whn-like), encoding a putative transcriptional regulator with a DNA binding domain similar to that of mouse Winged-helix nude (Whn) was cloned. Analyses of the phenotypes produced by a hypomorphic mutation and transgene expression suggested a role in cell fate decision during the differentiation of the compound eye, wing veins and bristles. During embryonic development, Dwhn expression started ubiquitously followed by more restricted expression in striking contrast to the expression patterns of other Drosophila forkhead (fkh) family genes whose local expression correlate well to their roles as local homeotic genes. This broad expression may correspond to the multiple defects in embryos homozygous for strong alleles, such as defects in the formation of central and peripheral nervous systems, germ band retraction, head involution, and dorsal closure. The DNA binding specificity of Dwhn differed from that of Whn despite the strong sequence conservation in the DNA binding domain. Dwhn is the first invertebrate Whn-like transcriptional regulator, and should provide insights into the basic functions and evolution of the whn family genes.
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Affiliation(s)
- I Sugimura
- Division of Biological Science, Graduate School of Science, Nagoya University, Japan
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26
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Miloro M, Macy JM. Expanded polytetrafluoroethylene entubulation of the rabbit inferior alveolar nerve. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000; 89:292-8. [PMID: 10710452 DOI: 10.1016/s1079-2104(00)70091-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the use of an expanded polytetrafluoroethylene conduit in the treatment of a 6. 0-mm gap in the rabbit inferior alveolar nerve and compare the results with those of an autogenous interpositional tibial nerve graft. STUDY DESIGN The inferior alveolar nerves of 5 adult New Zealand White female rabbits (10 nerves) were exposed bilaterally, and a 6-mm segment of each nerve was resected. On one side, chosen at random, the gap was immediately bridged through use of an 8.0 x 2. 0-mm expanded polytetrafluoroethylene conduit; on the other side, the gap was grafted with an autogenous tibial nerve graft. Two randomly selected nerves served as sham-dissected controls. At 15 weeks after surgery, the animals were killed and the entire nerve segments were harvested and prepared according to standard fixation and embedding techniques. The sections were examined histomorphometrically to quantify the degree of axonal regeneration through definition of fascicular number, total fascicular surface area, axonal density, and mean axonal diameter at 3 locations along the repair site. RESULTS Light microscopic examination revealed the presence of disorganized neural tissue in both groups, with slightly more fibrovascular interfascicular tissue in the expanded polytetrafluoroethylene group. Histomorphometric analysis revealed no significant differences between groups for most of the measured variables. The mean axonal diameter varied between groups, and the fascicular number was greater in the expanded polytetrafluoroethylene group at the middle site. CONCLUSIONS This study demonstrates that regeneration of the inferior alveolar nerve can occur across a 6.0-mm gap through an expanded polytetrafluoroethylene tube with results comparable to those of an autogenous nerve graft, significant donor site morbidity being avoided. The significant differences between groups were probably due to greater containment of regenerating axonal fibers in the expanded polytetrafluoroethylene group.
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Affiliation(s)
- M Miloro
- Department of Oral and Maxillofacial Surgery, University of Maryland at Baltimore, MD, USA
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27
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Abstract
The aim of the present investigation was to examine dentin and pulp in amalgam-restored teeth in minipigs with respect to presence of mercury, and to evaluate whether lining of restored cavities with a resin-modified glass ionomer cement had any effect on the penetration of mercury. Class I and V cavities were cut in 49 posterior and canine teeth of 4 minipigs. 35 cavities were restored with amalgam and 14 with composite material. 26 of the amalgam cavities were lined with a resin-modified glass ionomer cement. Following observation periods of 17-28 months, the pigs were killed and the jaws sectioned. After decalcification, the teeth were processed for light or electron microscopy examinations. Mercury was visualized by autometallography. Silver-enhanced mercury was found in all teeth with amalgam, whereas teeth with composites were devoid of mercury. Mercury could be traced in the odontoblast processes, in the body of odontoblasts, and on rare occasions in the nerve tissue of the pulp from lined and from unlined amalgam restorations. The present study thus demonstrates transport of mercury through dentinal tubules to the pulp, and that lining of cavities with a resin-modified glass ionomer cement does not prevent penetration of mercury.
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Affiliation(s)
- P Hörsted-Bindslev
- Department of Dental Pathology, Operative Dentistry and Endodontics, Royal Dental College, Aarhus C, Denmark
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28
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Abstract
The influence of a volume of a distal nerve segment upon nerve regeneration in an 8-mm gap created within a silicone tube was examined. The rats were randomly divided into four groups. Each group had 5 mm, 1 mm, or a half volume of 1-mm nerve segment (a nerve piece of 1 mm transected longitudinally) inserted into the distal end of a silicone tube of 11 mm. The empty group without a nerve segment was used as control. Diameters of regenerated cylindrical structure between the nerve ends in the silicone tube were measured under an operation microscope and myelinated axon diameter, myelinated axon density, myelin sheath width, and ratio of myelinated axon area to total cross sectional area were measured using the transverse sections at the midpoint of the silicone tube at 6 weeks after surgery. Although there was a significant difference in all of those parameters between the control group and any of the remaining three groups, no significant difference was found between any pair of these three groups. The results of this study indicated that the degree of nerve regeneration does not correlate with the volume of a distal nerve segment and even a very small piece can play an important role in supporting regenerating nerve beyond a definitive gap.
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Affiliation(s)
- W Zhang
- Department of Orthopaedic Surgery, Hiroshima University School of Medicine, Japan
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29
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Abstract
The aim of this study was to investigate the effects of a surgical tissue expansion procedure on the biomechanical features of the expanded soft tissues. In this procedure a silicone balloon "expander" is surgically inserted into a tissue and inflated. The tissue mass increases under the stretch of the expander. The increased tissue can then be used as an autologous source for the surgical reconstruction of organs. In this article, dog saphenous neurovascular bundle was used. Expanded saphenous nerves, arteries and veins were harvested and their biomechanical features and ultrastructural, histological changes were studied. The stress relaxation features, the continuous spectrum of relaxation time, and the stress-strain relationship of expanded and control specimens were measured. Results show that within two or three weeks after placement of the expanders, the biomechanical properties of expanded saphenous nerves, arteries and veins began to deviate from those of their controls, and the differences between them were proportional to the volume of inflation; but when the expanding period was 15 weeks or longer, the properties of expanded specimens and their controls became close again. Histological study showed that the content of collagenous fibers in blood vessel walls decreased after expansion. The content of elastic fibers in blood vessel walls first increased, then returned to normal, and finally decreased. Ultrastructural studies showed that when elongated by 25-40%, the expanded nerves had well preserved axons and showed fewer smooth myelin sheaths only in the middle and distal part of the expansion.
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Affiliation(s)
- G Fu
- Department of Basic Science, Beijing Polytechnic University, P.R. China
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Ryabov EV, Alieva IB, Uzbekov RE, Uzbekova SV, Vorobjev LA. Polyclonal antibodies against human gamma-tubulin stain centrioles in mammalian cells from different tissues. Membr Cell Biol 1997; 10:503-13. [PMID: 9225254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Rabbit polyclonal antibodies were raised against the C-terminal fragment (amino acid residues 318-451) of human gamma-tubulin. These antibodies were used to stain cultured cells of various tissues (epithelium, nervous tissue, fibroblasts) from different animals (human, monkey, pig, rat, kangaroo rat, mouse, hamster, chicken, triton). The antibodies specifically stained centrioles in the interphase and mitotic cells of mammals, but not birds (chicken) or amphibians (newt). In the interphase cells, centrioles were stained as a pair of dots (or as a double dot) in 96-97% of the cells. The distances between the maternal and filial centrioles varied in different cultures. Procentrioles were stained in certain cells, but with less intensity than mature centrioles. In mitotic cells, the antibodies revealed two spots corresponding to two mitotic poles. The spots in mitosis were significantly larger than the interphase dots, but the staining was more faint. In spontaneous tripolar mitoses, only two poles were stained. Thus, it was shown that, on the one hand, gamma-tubulin is associated with centrioles irrespective of whether or not they serve as the microtubule organizing centres and, on the other hand, gamma-tubulin might not be an essential component of the microtubule organizing centres.
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31
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Stancić MF, Mićović V, Bobinac D, Starcević G, Fuzinac A, Tomljanović Z. Electromyographic evaluation of experimental nerve grafts suggests better recovery with microscope assistance. Pflugers Arch 1996; 431:R285-6. [PMID: 8739376 DOI: 10.1007/bf02346380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Controversy surrounds the value of optic magnification for peripheral nerve surgery. The aim of this study was to compare the loupe magnification with microscope-assisted techniques in a rat tibial nerve graft model. The parameters studied included motor nerve conduction velocity (MNCV), clinical test equivalent (CTE), soleus muscle weight (SMW) and morphometric nerve indices. In the loupe and microscope groups MNCV mean was 26.77 +/- 9.37 m/sec and 44.19 +/- 11.36 m/sec respectively. MNCV results suggest better regeneration in the microscope group, as confirmed by CTE, SMW and myelinated fibre (MF) diameter.
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Affiliation(s)
- M F Stancić
- Department of Anatomy, Rijeka University Medical School, Croatia
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32
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Abstract
We describe modifications and improvements to our first report of a new nuclear emulsion coating technique for both light and electron microscopic autoradiography. Although this technique was originally designed to facilitate electron microscopic autoradiography, the methodology also allows pre-staining of plastic-embedded tissue sections prior to coating the slides with nuclear emulsion for light microscopic autoradiography. We now demonstrate that paraffin sections can be autoradiographically processed after being subjected to a combination of immunocytochemical reactions and special neuroanatomical strains. Parlodion film has been found to be more resistant to temperature changes and less prone to contamination than Formvar film. The shape of the double adhesive tape is an important aspect of the electron microscopic technique; it has been modified to minimize contamination and facilitate the removal of the grids from the glass slide. These technical adjustments facilitate the application of the nuclear emulsion and increase radionuclide specificity, thus expanding the investigative horizons of light and electron microscopic autoradiography.
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Affiliation(s)
- G V Kornhauser
- Department of Anatomy, George Washington University Medical Center, Washington, DC 20037, USA
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33
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Hirata T, Harada N. Electron microscopic observations of small unmyelinated nerve tissue proper in a dermal lesion of a relapsed lepromatous patient. Int J Lepr Other Mycobact Dis 1994; 62:619-22. [PMID: 7868966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Yasuda T, Yamanouchi Y, Tsubura A, Matsumura H, Morii S. Neuron-specific enolase and glial fibrillary acidic protein in vitamin-A-induced mouse myeloschisis: an immunohistochemical study. Pediatr Neurosurg 1993; 19:21-4. [PMID: 8422324 DOI: 10.1159/000120695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In an effort to establish the appropriate timing of myeloschisis repair, changes in the exposed neural tissue were studied during fetal development. Neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) were examined immunohistochemically in mice with vitamin-A-induced myeloschisis. As in the normally developing lumbosacral spinal cord, NSE was already expressed in the cytoplasm of neurons in the basal plate of the neural plaque in 16-day-old embryos. GFAP became positive at day 17 both in normal embryos and at the outer border of the plaques in dysraphic embryos. Expression of both NSE and GFAP in normal controls was unchanged in intensity and localization during later fetal development. In contrast, the expression of GFAP increased during later development in the neural plaque of dysraphic animals and suggests a progressive gliosis of tissue with the passage of time. The expression of NSE in the plaque did not change during this time. These results suggest that the neural plaque retains intact neurons in the face of progressive gliosis. Moreover, the results suggest that repair of the myeloschisis should start before irreversible changes are established by progressive gliosis.
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Affiliation(s)
- T Yasuda
- Department of Neurosurgery, Kansai Medical University, Moriguchi, Japan
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Baerwald RJ, Williamson LC, Stevens E, Rike C, Trabanino S, Carlton J. Isolation, ultrastructure, and partial characterization of collagen from the perineurium of the Florida lobster, Panulirus argus. Biochem Cell Biol 1991; 69:531-6. [PMID: 1760157 DOI: 10.1139/o91-078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Highly concentrated extracellular filaments in the perineurium of the Florida spiny lobster, Panulirus argus, were isolated using ultracentrifugation and linear sucrose gradients. The pellet obtained was highly enriched for the filaments as observed by transmission electron microscopy. Fibril diameter and axial periodicity measurements were obtained from filaments positively and negatively stained with uranyl acetate. A period between 14.0 and 25.0 nm and an average fibril diameter of 15.0 nm were observed. The filaments proved resistant to solubilization by most conventional agents and by several collagenases. NaOH (0.1 M at 100 degrees C) safely dissolved the filaments for measurements of protein content by the Lowry method and carbohydrate content with anthrone reagent. These tests revealed a protein content of approximately 84% and a high carbohydrate content of approximately 15%. Polyacrylamide electrophoresis of an acid-pepsin filament extract revealed a highly concentrated band (approximately 100,000) corresponding to the alpha-1 and alpha-2 bands of vertebrate type I collagen. Wide angle X-ray diffraction yielded meridional reflections that confirmed the filaments as collagen when compared with mammalian collagen X-ray diffraction. The amino acid composition was determined with a computer-assisted Beckman amino acid analyzer, which showed a glycine content of 279 residues/1000. Hydroxylysine and hydroxyproline were present in lower concentrations than expected.
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Affiliation(s)
- R J Baerwald
- Department of Biological Sciences, University of New Orleans, LA 70148
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36
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Abstract
Undifferentiated NG108-15 cells forming rapid-onset neurites were acutely exposed to nocodazole or trypsin. Resorption, cell rounding and detachment were delayed or prevented by 5'-deoxy,5'-methylthioadenosine (MTA), which selectively enhanced the strength of attachment responses. However, taxol, which stabilized microtubules, did not protect cell shape appreciably when trypsin or mechanical stimuli were used to decrease the strength of attachment. Together with numerous control experiments, this evidence suggests that the mechanical properties of microtubules do not contribute acutely to maintaining cell shape, though microtubules may play an indirect regulatory role (e.g. through their interactions with actin and substratum attachment sites). Patterns of trypsin-induced resorption resembled those seen 'spontaneously' in NG108-15 cells growing on laminin, and in fibroblastic CHO cells, suggesting that these results may be both physiologically relevant and applicable widely to many cell types.
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Affiliation(s)
- N R Smalheiser
- Department of Pediatrics, University of Chicago, IL 60637
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Ginsberg L, Gilbert DL, Gershfeld NL. Membrane bilayer assembly in neural tissue of rat and squid as a critical phenomenon: influence of temperature and membrane proteins. J Membr Biol 1991; 119:65-73. [PMID: 2008012 DOI: 10.1007/bf01868541] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cell membrane bilayers have been reconstructed in vitro utilizing total lipid extracts from rat neural tissue (forebrain, cerebellum, brainstem and spinal cord) and from the optic lobe and fin nerve of the squid Loligo pealei. In agreement with the critical state theory of bilayer assembly (Gershfeld, N.L. 1986. Biophys. J. 50:457-461; Gershfeld, NL.L. 1989. J. Phys. Chem. 93:5256-5261), these lipid extracts spontaneously formed purely unilamellar structures in aqueous dispersion, but only at a critical temperature, T*, which was species dependent. For all the rat tissues T* = 37 +/- 1 degrees C; for squid neural extracts T* = 15.5 +/- 1.4 degrees C. These values correspond to 'physiological' temperatures for both organisms, implying that their lipid metabolism is geared to permit spontaneous assembly of unilamellar membranes at the ambient temperature in the tissues. Membrane protein composition had little or no effect on critical bilayer formation.
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Affiliation(s)
- L Ginsberg
- Laboratory of Physical Biology, National Institute of Arthritis and Musculoskeletal and Skin Disease, National Institutes of Health, Bethesda, Maryland 20892
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38
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Abstract
This paper reports a technique using microwaves to assist penetration of stains into biopsy sections of muscle and peripheral nerve. The technique results in more consistent and reliable staining of tissue sections for examination by light microscopy.
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Affiliation(s)
- J Bonner
- Department of Medicine, University of Sydney, NSW, Australia
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39
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Palaoğlu S, Erbengi A, Kaya S, Erbengi T, Türker RK. Improved survival of transplanted cortical brain tissue grafts by iloprost in rats. Surg Neurol 1990; 34:212-8. [PMID: 1697985 DOI: 10.1016/0090-3019(90)90131-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The cytoprotective effect of iloprost on the viability and survival of embryonic cortical brain tissue grafts was examined ultrastructurally under light and electron microscopy before and 4 weeks after transplantation surgery. It was shown that neural grafts stored in iloprost solution (50 ng/mL) for 3 hours were more or less in a normal cytoarchitecture compared with saline-preserved grafts. Moreover, it was demonstrated that 4 weeks after transplantation, graft tissues stored in iloprost solution for 3 hours before implantation maintained a successful survival. Thus, a higher cellular population with new vascularization areas and preservation of myelin formation were accepted as a desirable integration of the graft tissue into the host brain tissue. The mechanism of action of iloprost is discussed.
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Affiliation(s)
- S Palaoğlu
- Department of Neurosurgery, School of Medicine, University of Hacettepe, Ankara, Turkey
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40
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Wróblewski R. In situ elemental analysis and visualization in cryofixed nervous tissues. X-ray microanalytical investigations of embryological and mature brain, inner ear, photoreceptors, muscle and muscle spindles. Comparison of preparation methods for analysis and visualization at cellular and subcellular levels. J Microsc 1989; 155:81-112. [PMID: 2671383 DOI: 10.1111/j.1365-2818.1989.tb04299.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
For meaningful X-ray microanalysis (XRMA) in biology and medicine, the development of preparative and quantitative methods has been necessary. The methods need to preserve close to in vivo distribution of diffusible ions with at the same time reasonable morphological preservation of the tissue. Analyses at low and middle microanalytical resolution are useful at the initial stages of an investigation or when data from large populations of samples have to be acquired. Cryomicrotomy, which makes it possible for the single cells within semi-thin and thick cryosections examined by X-ray microanalysis to be further characterized histochemically (enzyme and substrate content), has been adopted for several pathophysiological studies. The method is particularly suitable for the analysis of complex morphological tissues with many cell types as in the brain or sensory organs of the internal ear. For microanalysis at the subcellular level, we developed a preparative procedure based on the frozen fixed preparation which is freeze-dried in vacuo at -80 degrees C and then at the same temperature, without breaking the vacuum, impregnated with a low-temperature Lowicryl-type resin. The resin is polymerized by u.v. light. This method prevents redistribution of the ions in the tissue and retains the antigenicity of the tissue. A considerable number of cells can be analysed simultaneously and the elemental composition in different cell compartments can be compared due to the similar analytical conditions within the section. An alternative to thin plastic sections of freeze-dried material is thin cryosections cut at -150 degrees C and analysed at low temperatures. Although some methodological problems still exist in preparation of cryosections, this type of section is potentially the most useful in analysis of diffusible ions, especially calcium which in most biological systems is present in very low concentrations. New preparative techniques for XRMA brought severe problems in visualization of the specimens prepared by cryomethods. Charging, low contrast, mass loss and contamination, which are often negligible in conventional electron microscopy, have still to be solved in XRMA of cryoprepared specimens. However, the methods of semi-thin and thick cryosectioning and low-temperature embedding were successfully used for analysis of cells and organelles and for the study of fluids in restricted biological spaces such as the inner ear, muscle spindles and ventricles of the brain in rats. Accordingly, examinations which were impossible by micropuncture and ion selective techniques could be carried out by XRMA.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- R Wróblewski
- Department of Pathology, Karolinska Institute, Stockholm, Sweden
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Seybold V, Rösner H, Greis C, Beck E, Rahmann H. Possible involvement of polysialogangliosides in nerve sprouting and cell contact formation: an ultracytochemical in vitro study. J Neurochem 1989; 52:1958-61. [PMID: 2723652 DOI: 10.1111/j.1471-4159.1989.tb07286.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In Cichlid fish (Oreochromis mossambicus) primary cell cultures from whole brain and optic tectum, the differentiation-dependent distribution of polysialogangliosides on the outer cell surface has been followed on an ultrastructural level. For this, a two-step labeling technique with the monoclonal mouse antibody Q211, recognizing a polysialoganglioside-associated epitope, followed by a secondary IgM antibody, coupled to colloidal gold sols as an electron-dense marker, has been used. The gold grains are not uniformly distributed over the whole cell surface, but rather are clearly arranged clusters. In cells from freshly hatched larvae, both cell bodies and nerve fibers strongly exhibit the polysialoganglioside epitope on their surface. With progressing development, neuronal cell labeling is more and more restricted to nerve fibers and especially to cellular adhesion zones, including synaptic terminals, thus suggesting a functional involvement of polysialogangliosides in nerve sprouting and initiation of both cell-to-extracellular matrix and cell-to-cell contacts.
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Affiliation(s)
- V Seybold
- Institute of Zoology, University of Stuttgart-Hohenheim, F.R.G
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42
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Affiliation(s)
- J R Elliott
- Department of Anatomy and Physiology, Old Medical School, University, Dundee U.K
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43
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Saxén L. Neural induction. Int J Dev Biol 1989; 33:21-48. [PMID: 2562048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- L Saxén
- Department of Pathology, University of Helsinki, Finland
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44
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Abstract
Following partial denervation motor units can increase (by self-reinnervation) as much as four to five times their normal size. To investigate the still unknown quantitative reinnervation capacity of a motor nerve in the case of foreign-reinnervation, in adult male rats the denervated sternomastoid muscle was either self-reinnervated by its original nerve or foreign-reinnervation by the omohyoid nerve, which had to reinnervate the three times the amount of muscle fibers and six times the amount of muscle mass. After survival times of 7, 8, 9, or 10 months, nerves and muscles were investigated histochemically and immunohistochemically. The omohyoid nerve could fully reinnervate the sternomastoid muscle, but at 7 and 8 months this muscle still revealed nearly the same proportions of IIA and IIB fibers as were seen in the self-reinnervated sternomastoid at all stages. However, in the following 2 months a shift of the fiber pattern toward that of the normal omohyoid was observed, as evidenced by a strong increase in type IIB fibers (from 24% to 62%), at the expense of type IIA fibers. These findings are in contrast to those after foreign (cross) reinnervation of leg muscles where the fiber transformation (according to the foreign motor input) occurs in parallel with the reinnervation process during the first 2-3 months. The delayed fiber transformation observed could be the consequence of the highly enlarged peripheral field of the omohyoid motoneuron pool or could merely reflect a general difference between limb and neck muscles.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L Käser
- Institute of Anatomy, University of Zürich-Irchel, Switzerland
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45
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Zhuravleva ZN. [Electron microscopic research on the manifestations of transport-metabolic interactions in intraocular nerve tissue grafts]. Tsitologiia 1989; 31:42-8. [PMID: 2718258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Electron microscopic study of intraocular grafts of the septal and hippocampal nervous tissue revealed intensive transport and metabolic interactions between various types of the cells. High level of transport exists between the recipient's blood and intraocular fluid, on the one hand, and the graft, on the other one; the abundance of pinocytotic vesicles in the endothelium, pericytes and the glial end-feet of the capillaries, and the presence of microvilli and cilia on the graft limiting glia. Signs of active communications between interstitial glial cells, as well as between gliocytes and neurons, such as pinocytosis and gap junctions were observed. Similar interactions exist between various parts of nerve cells. Besides, there is an evidence of microphagocytic interactions, particularly between pre- and postsynaptic elements, as shown by the presence of so-called spinules. An unusual fact was observed of internalization of cytoplasmic fragments of the degenerating neuron by contacting synaptic boutons. It is suggested that the high level of transport and metabolic processes may reflect adaptive and compensatory processes in the nervous tissue developing under strict limitations of the neural and neurotrophic influences.
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46
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Weihe E, Hartschuh W. Multiple peptides in cutaneous nerves: regulators under physiological conditions and a pathogenetic role in skin disease? Semin Dermatol 1988; 7:284-300. [PMID: 3153452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- E Weihe
- Department of Anatomy, Johannes Gutenberg-Universität Mainz, FRG
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47
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Abstract
Neural transplantation has recently emerged as an exciting extension of neural regeneration and plasticity studies. In this review, the roots of current attempts at autologous and heterologous grafting of neural tissue are traced. Grafts of peripheral and central nervous tissue have been shown to be viable after implantation in a variety of locations in adult animals' brain and spinal cord, and survival data are impressive. Donor tissue is optimal when harvested from fetuses, and successful growth and differentiation of neural grafts have been demonstrated in host animals in a broad age range. A variety of morphologic, physiologic, and behavioral parameters suggest a certain degree of integration of graft tissue into the host central nervous system, although technical limitations do not yet allow definitive statements regarding the extent of functional reinnervation. Perhaps the most promising and innovative of current studies are those that utilize a combination of peripheral and central neural tissue as transplant material. There are a number of possible applications of neural transplantation to clinical neurology and neurosurgery, some of which are discussed.
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Affiliation(s)
- E L Zager
- Neurosurgical Service, Brigham and Women's Hospital, Boston, Massachusetts 02115
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48
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Zhuravleva ZN. [Ultrastructure of the synaptic endings in nerve tissue transplants developing in the anterior chamber]. Ontogenez 1987; 18:631-8. [PMID: 3431796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Embryonic septum of hippocampus was grafted into the anterior eye chamber (AEC) of adult recipient rats. The fine structure and distribution of synaptic endings were studied in the hippocampus (HC) and septum (ST) grafts developing in oculo for 3-4 months. On the basis of the structure of postsynaptic regions, asymmetrical and symmetrical synapses are distinguished, whose distribution on the body and dendrites of hippocampal and septal neurons is basically similar with that in situ. As in vivo, axo-somatic, axo-dendrite and axo-spine forms of synaptic endings have been observed. Neuropile has, basically, normal structure, judging by the ratio of nerve and glial elements, but sometimes dendro-dendrite contacts and glomerular-like synaptic structures are observed which are not characteristic of the studied brain regions. Besides, the grafts contain an increased number of serial and tangential synapses, as well as axonal terminals with the signs of growth cones. The observed structural deviations appear to be due to incomplete tissue maturation in the absence of normal afferentation.
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49
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Abstract
It was shown that opioid peptides stimulate nervous tissue growth in culture in the rat, which manifests itself in augmented outgrowth of neurites from explants and in an increase in the number of glial and fibroblast-like cells in the growth zone. The effects of opioid peptides ([Leu]- and [Met]-enkephalins, beta- and gamma-endorphins and some synthetic analogues of [Leu]-enkephalin) on the growth of organotypic cultures of rat sympathetic and dorsal root ganglia and spinal cord were investigated. Neurite outgrowth, cell composition, and size of the growth zone as well as the dynamics of its formation were estimated. Changes in the survival of neurons in dorsal root ganglion cultures were determined. The experiments were performed with living cultures as well as with fixed preparations. In experiments with sympathetic ganglia, it was demonstrated that a significant growth-promoting effect is exerted by peptides taken at concentrations of 10(-8) M to 10(-14) M. Naloxone does not eliminate the effects of peptides, but stimulates the growth at 10(-5) M to 10(-7) M. Studies with spinal cord revealed that naloxone (10(-6) M) enhances the response to [Leu]-enkephalin (10(-9) M). The survival of dorsal root ganglion neurons under the influence of a [leu]-enkephalin analog (10(-9) M) exceeds control values by approximately two to four times. Thus, opioid peptides were shown to exert a strong growth-promoting effect on nervous tissue in culture. This effect is dual: in neurons the peptides stimulate the outgrowth of neurites and their survival, while in glial cells they change the rate of their migration and, probably, their proliferation. It is suggested that opioid peptides, besides their already established functions, may play a role in the development and regeneration of nervous tissue.
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Affiliation(s)
- O B Ilyinsky
- Laboratory of Cell Physiology, Institute of Experimental Cardiology, U.S.S.R., Moscow
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50
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Zhuravleva ZN. [Ultrastructure of nervous tissue developing in the anterior chamber of the eye. 1. Perikaryons and dendrites]. Ontogenez 1987; 18:369-79. [PMID: 3658308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Embryonic tissues of septum and hippocampus were transplanted into the anterior eye chamber (AEC) of adult rats. The morphology of initial embryonic tissues and of transplants within 3 to 4 months of cultivation in AEC was studied. The transplanted tissue consists of neuroblasts and immature neurones: no synaptic contacts are observed. Within 3 to 4 months, highly differentiated neurones establishing synaptic contacts can be seen in the transplants. At the same time the fine structure of perikaryons and dendrites undergoes some changes: increased vacuolization, transformation of ergastoplasm into lamellar bodies. These can be due to an elevated functional activity of some neurones. Another group of morphological abnormalities (increased number of dendrite processes and microphyllopodia, somatic spines, dendrite cones of growth, tight junctions between perikaryons) suggests incomplete tissue maturation. These might be due to the absence of normal afferent and trophic influences in AEC.
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