scholarly journals Lens metabolic cooperation: a study of mouse lens transport and permeability visualized with freeze-substitution autoradiography and electron microscopy.

1980 ◽  
Vol 86 (2) ◽  
pp. 576-589 ◽  
Author(s):  
D A Goodenough ◽  
J S Dick ◽  
J E Lyons
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Freeze Fracture ◽  
Freeze Substitution ◽  
Species Variation ◽  
Metabolic Cooperation ◽  
Zonulae Occludentes ◽  
Lens Fibers ◽  
Mouse Lens

Transport of metabolites is demonstrated between compartments of the adult mouse lens by freeze-substitution autoradiography. In vivo patterns of lysine incorporation are compared with in vitro patterns of lysine, glucose, uridine, and deoxyglucose incorporation. Intracellular and extracellular distributions of tritiated metabolites are determined by comparison of transported substrates with the nontransported molecules of similar molecular size: mannitol and sucrose. The permeability of the lens intercellular spaces is probed with Procion Yellow at the level of fluorescence microscopy, and with horseradish peroxidase at the electron microscope level. Freeze-fracture electron microscopy reveals gap junctions between epithelial cells, between lens fibers, and between epithelial cells and lens fibers. Zonulae occludentes (tight junctions) are not routinely observed between epithelial cells in the mouse. This latter result is subject to species variation, however, since zonulae occludentes are abundant between chicken epithelial cells. The permeability results suggest that the lens cells are capable of metabolic cooperation, mediated by an extensive gap junction network.

Cationic Liposome-DNA Complexes: Polymorphism versus Transfection Activity

2000 ◽  
Vol 6 (S2) ◽  
pp. 854-855
Author(s):  
B. Sternberg-Papahadjopoulos ◽  
K. Hong ◽  
W. Zheng ◽  
D. Papahadjopoulos
Keyword(s):  
Electron Microscopy ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Cationic Liposome ◽  
Specific Structure ◽  
Spherical Particles ◽  
Cubic Phase ◽  
Active Structure

Complexes formed during interaction of cationic liposomes with polynucleotides such as DNA (CLDC) self-assemble into a variety of polymorphic structures. They display bilayer (FIG. 1-5) and non-bilayer structures (FIG. 6). We have recorded bilayer structures such as spaghetti/meatball-type structures (FIG. I), map-pins (FIG. 2) spherical particles and invaginated liposomes (FIG. 3, 4) and oligolamellar structures (FIG. 5). The non-bilayer lipid arrangements include honeycombtype structure (Hn, FIG. 6) and cubic phase lipids.We have chosen mainly freeze-fracture electron microscopy (FIG. 1-3, 5,6) but also cryo-electron microscopy (FIG.4) for recording polymorphic structures, and for studying factors and conditions triggering the formation and stabilization of specific structure types. Furthermore, we took microscopically snapshots of the interaction of specific structure types with cultured cells. In order to find out the “active” structure in terms of transfection, we investigated the transfection activity both in vivo and in vitro of CLDC, and studied in parallel their morphology in serum as well as in cell medium.

In vitro human skin barrier perturbation by oleic acid: Thermal analysis and freeze fracture electron microscopy studies

1997 ◽  
Vol 293 (1-2) ◽  
pp. 77-85 ◽  
Author(s):  
Hanafi Tanojo ◽  
Anita Bos-van Geest ◽  
Joke A. Bouwstra ◽  
Hans E. Junginger ◽  
Harry E. Boodé
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Oleic Acid ◽  
Human Skin ◽  
Freeze Fracture ◽  
Skin Barrier ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron

Factors modulating mouse lens epithelial cell morphology with differentiation and development of a lentoid structure in vitro

Development ◽  
1987 ◽  
Vol 99 (1) ◽  
pp. 25-32
Author(s):  
A.L. Muggleton-Harris ◽  
N. Higbee
Keyword(s):  
Epithelial Cells ◽  
Collagen Gel ◽  
Cell Aggregation ◽  
Lens Epithelial Cell ◽  
Lens Capsule ◽  
Lens Epithelial Cells ◽  
Collagen Membrane ◽  
Mouse Lens

The morphological and cellular changes that occur with differentiation and development of a lentoid structure from cultured mouse lens epithelial cells have been found to be dependent on the presence of lens capsule in association with the cells. The development of the ‘lentoid body’ is a multiphase process involving cell replication, synthesis of mucosubstances and a basement collagen membrane, cell aggregation and differentiation. Stage-specific synthesis of lens proteins confirms that the genes regulating normal differentiation in vivo are operating in the in vitro system. The hydrated collagen gel studies described in this report demonstrate that the cuboidal morphology and apical-basal polarity of the lens epithelial cells are dependent on their relationship with the lens capsule. Following a replicative phase the cells assume a mesenchyme-like morphology and migrate into the gel. Trypsinized cells freed from the lens capsule replicate but form colonies on the surface of the gel. The implications of these results are discussed with respect to previous observations made on normal lens development and the abnormalities associated with the congenital cataractous embryonic lens.

scholarly journals HOST-PARASITE INTERACTION IN THE RAT RENAL PELVIS

1974 ◽  
Vol 140 (6) ◽  
pp. 1696-1711 ◽  
Author(s):  
Fredric J. Silverblatt
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Female Rats ◽  
Mucosal Barrier ◽  
Type Iii ◽  
Type Iv ◽  
Predominant Type ◽  
Initial Interaction ◽  
Host Parasite

The initial interaction between bacteria and the renal pelvic epithelium may determine whether intrarenal infection occurs. A model of retrograde pyelonephritis was employed to study these events by electron microscopy. Female rats received an intravesicular inoculation of a 0.5-ml suspension of Proteus mirabilis containing 108 organisms. At intervals after inoculation, the kidneys were fixed by intravascular perfusion and the tissues were prepared for electron microscopy. During the first 24 h, increasing numbers of bacteria were seen to be attached by pili to the renal pelvic epithelial cells. The organism appeared to cross the mucosal barrier by several mechanisms: (a) penetration into the cytoplasm of intact epithelial cells, (b) passage between epithelial cells that were separated by excessive hydrostatic pressure generated during bladder inoculation, (c) passage across necrotic regions of the pelvis, and (d) translocation to the cortex by calicotubular backflow. Whereas at inoculation bacteria possessed pili 40 Å in diameter (type III pili) 24 h after reflux, the predominant type of pili measured 70 A in thickness (type IV pili). Repetitive subculture induced a similar transition in vitro. To assess the influence of pili type on virulence in this model, 80 rats were challenged with either type III or type IV pilated organisms and the frequency of rats with cortical abscesses were compared at 1 wk. A significantly greater number of rats inoculated with type IV pilated Proteus manifested macroscopic evidence of infection. These results suggest that pili play a role in the pathogenesis of ascending pyelonephritis.

scholarly journals Cell Wall-associated Protein A as a Tool for Immunolocalization of Staphylococcus aureus in Infected Human Airway Epithelium

2000 ◽  
Vol 48 (4) ◽  
pp. 523-533 ◽  
Author(s):  
Emmanuel Mongodin ◽  
Odile Bajolet ◽  
Jocelyne Hinnrasky ◽  
Edith Puchelle ◽  
Sophie de Bentzmann
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Epithelial Cells ◽  
Airway Epithelium ◽  
Protein A ◽  
Staphylococcal Protein A ◽  
Basal Cells ◽  
Bronchial Diseases

Staphylococcus aureus is a common human pathogen involved in non-bronchial diseases and in genetic and acquired bronchial diseases. In this study, we applied an immunolabeling approach for in vivo and in vitro detection of S. aureus, based on the affinity of staphylococcal protein A (SpA) for the Fc region of immunoglobulins, especially IgG. Most strains of S. aureus, including clinical strains, can be detected with this labeling technique. The approach can be used for detection and localization with transmission electron microscopy or light-fluorescence microscopy of S. aureus in infected tissues such as human bronchial tissue from cystic fibrosis (CF) patients. The methodology can also be applied to cell culture models with the aim of characterizing bacterial adherence to epithelial cells in backscattered electron imaging with scanning electron microscopy. Application to the study of S. aureus adherence to airway epithelium showed that the bacteria did not adhere in vivo to intact airway epithelium. In contrast, bacteria adhered to the basolateral plasma membrane of columnar cells, to basal cells, to the basement membrane and were identified beneath the lamina propria when the epithelium was injured and remodeled, or in vitro when the epithelial cells were dedifferentiated.

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