scholarly journals Immunocytochemical localization of actin in epithelial cells of rat small intestine by light and electron microscopy.

1988 ◽  
Vol 36 (7) ◽  
pp. 717-727 ◽  
Author(s):  
S J Hagen ◽  
J S Trier
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Basal Membrane ◽  
Ground Substance ◽  
Structural Protein ◽  
Thin Sections ◽  
Filament Bundles ◽  
Lowicryl K4m

We used post-embedding immunocytochemical techniques and affinity-purified anti-actin antibody to evaluate localization of actin in epithelial cells of small intestine by fluorescence and electron microscopy. Small intestine was fixed with 2% formaldehyde-0.1% glutaraldehyde and embedded in Lowicryl K4M. One-micron or thin sections were stained with antibody followed by rhodamine- or colloidal gold-labeled goat anti-rabbit IgG, respectively. Label was present overlying microvilli, the apical terminal web, and the cytoplasm directly adjacent to occluding and intermediate junctions. Label was associated with outer mitochondrial membranes of all cells and the supranuclear Golgi region of goblet cells. Lateral cytoplasmic interdigitations between mature cells and subplasmalemmal filaments next to intrusive cells were densely labeled. The cytoplasm adjacent to unplicated domains of lateral membrane was focally labeled. Label was prominent over organized filament bundles within the subplasmalemmal web at the base of mature cells, whereas there was focal labeling of the cytoplasm adjacent to the basal membrane of undifferentiated cells. Basolateral epithelial cell processes were labeled. Label was focally present overlying the cellular ground substance. Our results demonstrate that actin is distributed in a distinctive fashion within intestinal epithelial cells. This distribution suggests that in addition to its function as a structural protein, actin may participate in regulation of epithelial tight junction permeability, in motile processes including migration of cells from the crypt to the villus tip, in accommodation of intrusive intraepithelial cells and in adhesion of cells to one another and to their substratum.

Development of intercellular junctions in the pulmonary epithelium of the foetal lamb

1978 ◽  
Vol 32 (1) ◽  
pp. 307-324
Author(s):  
E.E. Schneeberger ◽  
D.V. Walters ◽  
R.E. Olver
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Tight Junctions ◽  
Lung Development ◽  
Light And Electron Microscopy ◽  
Intercellular Junctions ◽  
Intercellular Spaces ◽  
Thin Sections ◽  
Epithelial Tight Junctions ◽  
Foetal Lamb

The integrity of epithelial tight junctions in foetal mammalian lungs is essential to maintain the unique ionic composition of lung liquid, and to prevent leakage of serum proteins into peripheral air spaces. In the present study the development of intercellular junctions of the lining epithelium of foetal lamb lungs during gestation was examined by light and electron microscopy. Both thin sections and freeze-fracture replicas were examined by electron microscopy. By 39 days of gestation, epithelial tight junctions consist of a minimum of 3.1 +/− 1.6 (s.D.) and a maximum of 5.8 +/− 2.0 discontinuous rows of particles and short segments of strands on P face ridges and in complementary E face grooves, while from 58 to 76 days they are composed of a network of 4.3 +/− 1.6 to 7.7 +/− 1.9 focally interrupted P face strands. Complementary replicas show that many of the discontinuities on the P face are due to separation of junctional particles on to the E face during fracturing, and not to an absence of junctional particles. From 76 days to term, epithelial tight junctions (exclusive of upper airway epithelium which was not examined) resemble those of adult lungs, and consist of a continuous network of 4.5 +/− 2.0 to 7.5 +/− 2.5 P face strands and complementary particle-free grooves. Permeability measurements, published elsewhere, indicate that the epithelium is functionally ‘tight’ from 69 days onwards. Tight junctions in peripheral air-space epithelium, therefore, are structurally continuous and functionally ‘tight’ early in foetal lung development, and form seals at one end of long, narrow intercellular spaces; these features may be important for coupled ion and water transport. When the bounding epithelial cells become flattened, these narrow intercellular spaces remain intact as a result of complex interdigitations of adjacent cell membranes. Desmosomes were present throughout gestation near the abluminal side of the tight junctions and occasionally near the base of the intercellular space. These junctions may serve to connect cells to each other at a time when tight junctions may be mechanically weak. In addition, gap junctions are associated with tight junctions from the glandular through the canalicular stages of lung development. They disappear by 120 days when the epithelial cells are differentiated.

scholarly journals Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Kazuhiko Nakadate ◽  
Kento Motojima ◽  
Tomoya Hirakawa ◽  
Sawako Tanaka-Nakadate
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Rough Endoplasmic Reticulum ◽  
Defense Mechanism ◽  
Monosodium Glutamate ◽  
Light And Electron Microscopy ◽  
Obese Mice ◽  
Pathological Changes

Chronic obesity is a known risk factor for metabolic syndrome. However, little is known about pathological changes in the small intestine associated with chronic obesity. This study investigated cellular and subcellular level changes in the small intestine of obese mice. In this study, a mouse model of obesity was established by early postnatal administration of monosodium glutamate. Changes in body weight were monitored, and pathological changes in the small intestine were evaluated using hematoxylin-eosin and Nissl staining and light and electron microscopy. Consequently, obese mice were significantly heavier compared with controls from 9 weeks of age. Villi in the small intestine of obese mice were elongated and thinned. There was reduced hematoxylin staining in the epithelium of the small intestine of obese mice. Electron microscopy revealed a significant decrease in and shortening of rough endoplasmic reticulum in epithelial cells of the small intestine of obese mice compared with normal mice. The decrease in rough endoplasmic reticulum in the small intestine epithelial cells of obese mice indicates that obesity starting in childhood influences various functions of the small intestine, such as protein synthesis, and could impair both the defense mechanism against invasion of pathogenic microbes and nutritional absorption.

scholarly journals Light and electron microscopic demonstration of sialic acid residues with the lectin from Limax flavus: a cytochemical affinity technique with the use of fetuin-gold complexes.

1984 ◽  
Vol 32 (11) ◽  
pp. 1167-1176 ◽  
Author(s):  
J Roth ◽  
J M Lucocq ◽  
P M Charest
Keyword(s):  
Electron Microscopy ◽  
Sialic Acid ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
Gold Complexes ◽  
Thin Sections ◽  
Tissue Sections ◽  
Lowicryl K4m ◽  
Hydrolysis Of ◽  
Electron Microscopic Demonstration

The development of a cytochemical affinity technique for the demonstration of sialic acid residues by light and electron microscopy is reported. The lectin from the slug Limax flavus, with its narrow specificity for N-acetyl- and N-glycolylneuraminic acid, was applied to tissue sections. Subsequently fetuin-gold complexes were used to visualize the tissue-bound lectin. Different cytochemical controls, including sugar inhibition tests, neuraminidase digestion, the use of fetuin-gold complexes alone, or acid hydrolysis of sections, proved the specificity of the technique. Postembedding staining was performed on frozen, paraffin, or semithin resin sections for light microscopy and on thin sections from low temperature Lowicryl K4M-embedded material for electron microscopy. The distribution of sialic acid residues in rat pancreas, liver, and colonic mucosa was investigated.

scholarly journals Gnotobiotic Piglets Experimentally Infected with Neonatal Calf Diarrhoea Reovirus-Like Agent (Rotavirus)

1976 ◽  
Vol 13 (3) ◽  
pp. 197-210 ◽  
Author(s):  
G. A. Hall ◽  
Janice C. Bridger ◽  
R. L. Chandler ◽  
G. N. Woode
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Severe Damage ◽  
Severe Stunting ◽  
Virus Particles ◽  
Stomach Mucosa ◽  
Neonatal Calf ◽  
Gnotobiotic Piglets

Gnotobiotic piglets were infected with a strain of rotavirus that had been isolated from a calf and passaged four times in piglets. The resulting disease was studied by light and electron microscopy at 21, 44 and 68h after inoculation. In the small intestine infection caused desquamation of the epithelial cells of the villi resulting in severe stunting. There was severe damage to microvilli and accumulation of lipid within the cytoplasm. Virus particles were seen in epithelial cells covering the stunted villi. Infection also caused desquamation of the superficial epithelial cells of the stomach mucosa and of the epithelial cells of the bronchi, bronchioles, and alveoli of the lungs.

Immunoprobe localization in mammalian embryos

1990 ◽  
Vol 48 (3) ◽  
pp. 32-33
Author(s):  
Patricia G. Calarco ◽  
Margaret C. Siebert
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Thin Sections ◽  
Relative Lack ◽  
Large Size ◽  
Mammalian Embryos ◽  
Antigen Localization ◽  
Difficult Challenge ◽  
Lowicryl K4m ◽  
Fertilized Egg

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.

scholarly journals Effects of the cationic protein poly-L-arginine on airway epithelial cellsin vitro

2002 ◽  
Vol 11 (3) ◽  
pp. 141-148 ◽  
Author(s):  
Shahida Shahana ◽  
Caroline Kampf ◽  
Godfried M. Roomans
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Cell Membrane ◽  
Cell Damage ◽  
Membrane Damage ◽  
Light And Electron Microscopy ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Cationic Protein ◽  
Induced Apoptosis

Background: Allergic asthma is associated with an increased number of eosinophils in the airway wall. Eosinophils secrete cationic proteins, particularly major basic protein (MBP).Aim: To investigate the effect of synthetic cationic polypeptides such as poly-L-arginine, which can mimic the effect of MBP, on airway epithelial cells.Methods: Cultured airway epithelial cells were exposed to poly-L-arginine, and effects were determined by light and electron microscopy.Results: Poly-L-arginine induced apoptosis and necrosis. Transmission electron microscopy showed mitochondrial damage and changes in the nucleus. The tight junctions were damaged, as evidenced by penetration of lanthanum. Scanning electron microscopy showed a damaged cell membrane with many pores. Microanalysis showed a significant decrease in the cellular content of magnesium, phosphorus, sodium, potassium and chlorine, and an increase in calcium. Plakoglobin immunoreactivity in the cell membrane was decreased, indicating a decrease in the number of desmosomes.Conclusions: The results point to poly-L-arginine induced membrane damage, resulting in increased permeability, loss of cell-cell contacts and generalized cell damage.

Intestinal Lesions Containing Coronavirus-like Particles in Neonatal Necrotizing Enterocolitis: An Ultrastructural Analysis

PEDIATRICS ◽  
1984 ◽  
Vol 73 (2) ◽  
pp. 218-224
Author(s):  
S. Rousset ◽  
O. Moscovici ◽  
P. Lebon ◽  
J. P. Barbet ◽  
P. Helardot ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Necrotizing Enterocolitis ◽  
Intestinal Mucosa ◽  
Light And Electron Microscopy ◽  
Anaerobic Bacteria ◽  
Intestinal Lesions ◽  
Maternity Hospitals ◽  
Neonatal Necrotizing Enterocolitis

Since the outbreaks of neonatal necrotizing enterocolitis occurring in maternity hospitals of Paris and suburbs in 1979-1980, it has been possible to examine by light and electron microscopy gut specimens from ten newborns with this illness. Coronavirus-like particles, enclosed in intracytoplasmic vesicles of damaged epithelial cells of the intestinal mucosa, were observed in the small intestine, appendix, and colon. The ultrastructural study, supported by bacteriologic findings, suggests the role of coronavirus-like particles in the appearance of the lesions. Secondary proliferation of mainly anaerobic bacteria, probably responsible for pneumatosis, may aggravate the disease.

Replication factories and nuclear bodies: the ultrastructural characterization of replication sites during the cell cycle

1994 ◽  
Vol 107 (8) ◽  
pp. 2191-2202 ◽  
Author(s):  
P. Hozak ◽  
D.A. Jackson ◽  
P.R. Cook
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
S Phase ◽  
Nuclear Bodies ◽  
Nuclear Antigen ◽  
Thin Sections ◽  
Permeabilized Cells ◽  
Ultrastructural Characterization ◽  
Replication Sites ◽  
Proliferating Cell

Sites of replication in synchronized HeLa cells were visualized by light and electron microscopy; cells were permeabilized and incubated with biotin-16-dUTP, and incorporation sites were immunolabelled. Electron microscopy of thick resinless sections from which approximately 90% chromatin had been removed showed that most DNA synthesis occurs in specific dense structures (replication factories) attached to a diffuse nucleoskeleton. These factories appear at the end of G1-phase and quickly become active; as S-phase progresses, they increase in size and decrease in number like sites of incorporation seen by light microscopy. Electron microscopy of conventional thin sections proved that these factories are a subset of nuclear bodies; they changed in the same characteristic way and contained DNA polymerase alpha and proliferating cell nuclear antigen. As replication factories can be observed and labelled in non-permeabilized cells, they cannot be aggregation artifacts. Some replication occurs outside factories at discrete sites on the diffuse skeleton; it becomes significant by mid S-phase and later becomes concentrated beneath the lamina.

scholarly journals Thrombin induces a rapid redistribution of glycoprotein Ib-IX complexes within the membrane systems of activated human platelets

Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1503-1513 ◽  
Author(s):  
P Hourdille ◽  
E Heilmann ◽  
R Combrie ◽  
J Winckler ◽  
KJ Clemetson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Flow Cytometry ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Membrane Systems ◽  
Immunogold Staining ◽  
Thin Sections ◽  
Surface Areas ◽  
Lowicryl K4m

Abstract Previous studies have shown a decreased binding of monoclonal antibodies (MoAbs) to glycoprotein (GP) Ib-IX complexes on thrombin- stimulated platelets, but the reason for this is poorly understood. We have used (1) immunofluorescence procedures and flow cytometry, and (2) immunogold staining and electron microscopy to investigate this phenomenon. Washed platelets were incubated with alpha-thrombin, adenosine diphosphate, or ionophore A23187 for increasing lengths of time. For alpha-thrombin, but not the other agonists, flow cytometry confirmed a dose- and time-dependent decrease in the binding of MoAbs specific for GP Ib alpha (AP-1, Bx-1), GP IX (FMC 25), or to the complex itself (SZ 1). Immunoglold staining performed using standard transmission or scanning electron microscopy high-lighted surface areas devoid of bound antibody. However, a quantitatively normal immunofluorescence was restored if paraformaldehyde-fixed, thrombin- stimulated platelets were permeabilized with Triton X-100 (Sigma Chemical Co, St Louis, MO) before MoAb addition, while immunogold staining was now seen to be concentrated within the interior of the platelet. Glutaraldehyde-fixed samples were then embedded in the resin Lowicryl K4M (Taab Laboratories Equipment Ltd, Aldermaston, England) and immunogold staining performed on thin sections using a polyclonal antibody to glycocalicin. An increased presence of GP Ib-IX complexes within surface-connected membrane systems of the thrombin-stimulated platelets was confirmed. Interestingly, GP Ib-IX movement was opposite to the thrombin-induced externalization of internal pools of GP IIb- IIIa complexes and of the alpha-granule membrane GP, GMP-140.

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