scholarly journals Ultrastructural localization of guanylate cyclase in bone cells.

1991 ◽  
Vol 39 (4) ◽  
pp. 529-535 ◽  
Author(s):  
O Fukushima ◽  
C V Gay
Keyword(s):  
Plasma Membrane ◽  
Guanylate Cyclase ◽  
Bone Cells ◽  
Ultrastructural Localization ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Lead Citrate ◽  
Free Medium ◽  
Membrane Guanylate Cyclase ◽  
Electron Microscopic

Guanylyl imidodiphosphate (GMP-PNP) hydrolyzing enzyme activity as a means of detecting plasma membrane guanylate cyclase was demonstrated in osteoblasts of chicken tibial metaphysis using a lead citrate histochemical method at the electron microscopic level. Activity was not discerned in osteoclasts or osteocytes. The reaction product development was completely abolished when the sections were incubated with substrate-free or MnCl2-free medium. Guanylate-(beta, gamma-methylene) diphosphate (GMP-PCP) was a less effective substrate than GMP-PNP, and Mn++ was a stronger stimulator than Mg++. No reaction product was observed on the plasma membrane of osteoblasts when beta-glycerophosphate or p-nitrophenylphosphate was used as substrate instead of GMP-PNP. The results implicate guanylate cyclase as a significant effector of osteoblast regulation at the site of the plasma membrane.

The fine structure of ascus development in Lasiobolus monascus (Pezizales)

1978 ◽  
Vol 56 (7) ◽  
pp. 862-872 ◽  
Author(s):  
James W. Kimbrough ◽  
Gerald L. Benny
Keyword(s):  
Fine Structure ◽  
Uranyl Acetate ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Stalk Cell ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Ultrathin Sections ◽  
Microscopic Inspection ◽  
Physical And Chemical

Ultrastructural and cytochemical studies on the ascus of Lasiobolus monascus are presented. Apothecia in various stages of development were obtained in culture and prepared for both light and electron microscopic observations. Ultrathin sections for electron microscopic inspection were often treated with silver methenamine to enhance wall characteristics. Ascus development was followed from fertilization to maturity.In this species, the ascogonium enlarges after fertilization to become the ascus mother cell. Two pores are present in the young ascus, one connecting it to the antheridium and another between the ascus and stalk cell. The ultrastructural features of these pores in the young and maturing ascus are described. During ascus enlargement, as many as four wall layers are found when poststained with silver methenamine. Only two layers are clearly distinguishable when poststained with uranyl acetate and lead citrate. The apical zone of dehiscence is characterized by a distinct annular swelling which appears during early ascosporogenesis. By spore maturation, this swelling is not evident either at the light or electron microscopic level. Instead, there appear to be both physical and chemical changes in the area of dehiscence. The wall is distinctly thinner and much more electron transparent in the area of dehiscence when treated with silver methanamine.

scholarly journals Cellular and Subcellular Localisation of Kv4-Associated KChIP Proteins in the Rat Cerebellum

2020 ◽  
Vol 21 (17) ◽  
pp. 6403
Author(s):  
Rocío Alfaro-Ruíz ◽  
Carolina Aguado ◽  
Alejandro Martín-Belmonte ◽  
Ana Esther Moreno-Martínez ◽  
Rafael Luján
Keyword(s):  
Plasma Membrane ◽  
Purkinje Cells ◽  
Granule Cells ◽  
Distribution Patterns ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
K Channel ◽  
Subcellular Localisation ◽  
Electron Microscopic ◽  
Parallel Fibres

The K+ channel interacting proteins (KChIPs) are a family of cytosolic proteins that interact with Kv4 channels, leading to higher current density, modulation of channel inactivation and faster recovery from inactivation. Using immunohistochemical techniques at the light and electron microscopic level combined with quantitative analysis, we investigated the cellular and subcellular localisation of KChIP3 and KChIP4 to compare their distribution patterns with those for Kv4.2 and Kv4.3 in the cerebellar cortex. Immunohistochemistry at the light microscopic level demonstrated that KChIP3, KChIP4, Kv4.2 and Kv4.3 proteins were widely expressed in the cerebellum, with mostly overlapping patterns. Immunoelectron microscopic techniques showed that KChIP3, KChIP4, Kv4.2 and Kv4.3 shared virtually the same somato-dendritic domains of Purkinje cells and granule cells. Application of quantitative approaches showed that KChIP3 and KChIP4 were mainly membrane-associated, but also present at cytoplasmic sites close to the plasma membrane, in dendritic spines and shafts of Purkinje cells (PCs) and dendrites of granule cells (GCs). Similarly, immunoparticles for Kv4.2 and Kv4.3 were observed along the plasma membrane and at intracellular sites in the same neuron populations. In addition to the preferential postsynaptic distribution, KChIPs and Kv4 were also distributed presynaptically in parallel fibres and mossy fibres. Immunoparticles for KChIP3, KChIP4 and Kv4.3 were detected in parallel fibres, and KChIP3, KChIP4, Kv4.2 and Kv4.3 were found in parallel fibres, indicating that composition of KChIP and Kv4 seems to be input-dependent. Together, our findings unravelled previously uncharacterised KChIP and Kv4 subcellular localisation patterns in neurons, revealed that KChIP have additional Kv4-unrelated functions in the cerebellum and support the formation of macromolecular complexes between KChIP3 and KChIP4 with heterotetrameric Kv4.2/Kv4.3 channels.

scholarly journals Immunoelectron microscopic localization of estrogen receptor with monoclonal estrophilin antibodies.

1985 ◽  
Vol 33 (9) ◽  
pp. 915-924 ◽  
Author(s):  
M F Press ◽  
N A Nousek-Goebl ◽  
G L Greene
Keyword(s):  
Estrogen Receptor ◽  
Ultrastructural Localization ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Nuclear Staining ◽  
Cytoplasmic Localization ◽  
Electron Microscopic ◽  
Tissue Sections ◽  
Receptor Antibodies ◽  
Microscopic Techniques

The recent production of a series of monoclonal estrophilin (estrogen receptor) antibodies recognizing estrogen receptor derived from a wide variety of animals and target tissues permits the development of immunoelectron microscopic techniques for identifying estrogen receptor. We have determined suitable conditions for the ultrastructural localization of estrogen receptor in tissue sections. Localization of receptor was observed in the euchromatin, but not in the marginated heterochromatin or nucleoli of epithelial and stromal nuclei of human endometrium. Competition studies indicate that only estrogen receptor specifically inhibits nuclear staining. The absence of any specific cytoplasmic localization at the electron-microscopic level is consistent with earlier light-microscopic observations and suggests that the majority of the cellular pool of estrophilin exists in the nucleus of hormone-responsive cells.

Ultrastructural localization of soluble and insoluble 3H-methyl prednisolone as revealed by electron microscopic dry-mounting radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 40-41
Author(s):  
T. Nagata ◽  
K. Yoshida ◽  
S. Ohno ◽  
F. Murata
Keyword(s):  
Mouse Liver ◽  
Sodium Succinate ◽  
Ultrastructural Localization ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Methyl Prednisolone ◽  
Freeze Dried ◽  
Emulsion Films

IntroductionSince the recent improvements in both techniques and development in equipments at our laboratory or others, the dry-mounting procedures for radioautography facilitated the wide application of them for the study of soluble compounds such as nucleic acid precursors, amino acids, carbohydrates, lipids and steroids at both the light and electron microscopic levels. The purpose of this paper is to demonstrate ultrastructural localization of both soluble and insoluble 3H-labeled methyl prednisolone, a synthetic corticosteroid, by means of dry-mounting procedure at the electron microscopic level.Materials and MethodsMouse liver slices obtained from a male mouse and cultured HeLa cells were pulse- labeled in vitro in Eagle's MEM containing 6α-methyl prednisolone-1,2-T sodium succinate (100μCi/ml) for 1 hour.Some specimens were quickly frozen in isopentane cooled to -160°C with liquid nitrogen and freeze-dried,fixed in osmium vapour, embedded in Epon, dry-sectioned and dry-mounted according to the procedure described previously, by means of wire loops using Sakura NR-H2 emulsion containing dioctyl sodium sulfosuc- cinate in order to prevent the emulsion films from bursting while they are air dried.

scholarly journals Immunohistochemical characterization of a differentiation-specific carbohydrate epitope in the plasma membrane of the epithelial cells of rat small intestine.

1993 ◽  
Vol 41 (1) ◽  
pp. 71-79 ◽  
Author(s):  
H Schiechl
Keyword(s):  
Small Intestine ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Basolateral Membrane ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Lateral Part ◽  
Rat Small Intestine ◽  
Electron Microscopic

The monoclonal antibody (MAb) SI/EC1 was produced by immunization of Balb/c mice with an antigen prepared from the isolated basolateral membrane (BLM) of rat small intestine epithelial cells by trypsin cleavage. Immunohistochemical labeling at the light and electron microscopic level shows that the SI/EC1 epitope is localized in the plasma membrane (PM) of the small intestine epithelial cells and is expressed around Day 21 after birth (weaning time). There are, however, differences in the labeling between crypt and villous cells. In the crypt cells, the microvillous membrane (MVM) and the lateral part of the BLM are strongly labeled, whereas the basal part of the BLM is unlabeled. In the villous cells, both the MVM and the basal and lateral part of the BLM are labeled, but the labeling is not as intense as in the crypts. In immunoblotting experiments with the isolated BLM, three protein bands (125 KD, 110 KD, and 90 KD) were labeled specifically with the MAb. Enzymic cleaving of the BLM with exo- and endoglycosidases and subsequent immunoblotting, as well as other findings, suggest that the specific structure of the SI/EC1 epitope consists mainly of carbohydrates (CH) (oligosaccharides). This finding points out the possibility that this epitope may have something to do with the variable adhesion of the small intestine epithelial cells along the crypt-villus axis.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 64-65
Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata
Keyword(s):  
Mass Production ◽  
Identical Condition ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Simplified Method ◽  
Complicated Process ◽  
Critical Problems ◽  
Electron Microscopic Radioautography ◽  
Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

X-Ray Microanalysis of Nickel and Cobalt Intensified Peroxidase- Antiperoxidase For Verification of Reaction Sites

1985 ◽  
Vol 43 ◽  
pp. 468-469
Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel
Keyword(s):  
Reaction Mechanisms ◽  
Visual Discrimination ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
X Ray ◽  
Insoluble Polymer ◽  
Cytochemical Reaction

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.

scholarly journals Murine endodermal cytokeratins Endo A and Endo B are localized in the same intermediate filament.

1986 ◽  
Vol 34 (6) ◽  
pp. 785-793 ◽  
Author(s):  
W E Howe ◽  
F G Klier ◽  
R G Oshima
Keyword(s):  
Immunoelectron Microscopy ◽  
Intermediate Filament ◽  
Microscopic Level ◽  
Cytoskeletal Proteins ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Double Label ◽  
Secondary Antibodies ◽  
Endodermal Cells ◽  
20 Nm

The intracellular distribution of extra-embryonic endodermal, cytoskeletal proteins A (Endo A) and B (Endo B) was investigated by double-label immunofluorescent microscopy and double-label immunoelectron microscopy. In parietal endodermal cells, the immunofluorescent distribution of Endo B was always coincident with that of Endo A and could be distinguished from vimentin, particularly at the periphery of the cell. At the electron microscopic level, antibodies against both Endo A and Endo B recognized both bundles and individual intermediate filaments. Double-label immunoelectron microscopy was achieved by use of two sizes of colloidal gold particles (5 nm and 20 nm) that were stabilized with secondary antibodies. These results show that Endo A and B are found in the same intermediate filament and probably co-polymerize to form such structures.

scholarly journals FIXATION OF NEURAL TISSUES FOR ELECTRON MICROSCOPY BY PERFUSION WITH SOLUTIONS OF OSMIUM TETROXIDE

1962 ◽  
Vol 12 (2) ◽  
pp. 385-410 ◽  
Author(s):  
Sanford L. Palay ◽  
S. M. McGee-Russell ◽  
Spencer Gordon ◽  
Mary A. Grillo
Keyword(s):  
Electron Microscopy ◽  
Nervous System ◽  
Osmium Tetroxide ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Vascular Perfusion ◽  
Neural Tissues ◽  
Structural Relations ◽  
Cellular Components

This paper describes in detail a method for obtaining nearly uniform fixation of the nervous system by vascular perfusion with solutions of osmium tetroxide. Criteria are given for evaluating the degree of success achieved in the preservation of all the cellular components of the nervous system. The method permits analysis of the structural relations between cells at the electron microscopic level to an extent that has not been possible heretofore.

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