scholarly journals Localization of intestinal sucrase-isomaltase complex on the microvillous membrane by electron microscopy using nonlabeled antibodies

1978 ◽  
Vol 79 (2) ◽  
pp. 516-525 ◽  
Author(s):  
Y Nishi ◽  
Y Takesue
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Immunoglobulin G ◽  
Smooth Surface ◽  
External Surface ◽  
Membrane Surface ◽  
Fine Particulate ◽  
Rabbit Small Intestine ◽  
Intestinal Sucrase ◽  
Number Of Particles

Microvillous vesicles isolated from rabbit small intestine showed a trilaminar membrane with a rather smooth surface, which was apparently not affected by papain solubilizing sucrase-isomaltase complex or by trypsin unable to solubilize it. When microvilous vesicles or trysinized ones were incubated with immunoglobulin G against the sucrase-isomaltase complex or monovalent fragments therefrom, an apparently continuous electron-opaque layer approximately 180 A in width appeared around the external surface of vesicles. Such a layer was not formed on papainized vesicles. Microvillous vesicles and trypsinized ones negatively stained with phosphotungate showed a great number of particles protruding approximately 150 A from the membrane surface, but papainized vesicles did not. The particles existed close to one another and appeared to form a particulate layer 150 A in width on the surface. The antibodies, whether they were divalent or monovalent, increased the width of the layer to approximately 200 A and obscured the fine particulate structure of intact and trypsinized vesicles. Papainized vesicles retained their smooth surface upon interaction with antibodies. These results, together with those with the Triton-solubilized sucrase- isomaltase complex (Nishi and Takesue, 1978), J. Ultra-struct. Res., 62:1- 12), indicate not only that sucrase-isomaltase complexes are located close to one another on the membrane, but also that they or at least their protein portions protrude approximately 150 A from the surface of the trilaminar membrane.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

1970 ◽  
Vol 28 ◽  
pp. 306-307
Author(s):  
L. Andrew Staehelin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Resolution ◽  
Smooth Surfaces ◽  
Small Particles ◽  
Membrane Surfaces ◽  
Wide Acceptance ◽  
New Information ◽  
Number Of Particles ◽  
Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

A Sensitive On-Grid Immunoelectron Microscopic Procedure for Diagnosis of Rotavirus Infection

1980 ◽  
Vol 38 ◽  
pp. 506-507
Author(s):  
M. F. Miller ◽  
A. R. Rubenstein
Keyword(s):  
Electron Microscopy ◽  
Specific Antibody ◽  
Immune Complexes ◽  
Acute Gastroenteritis ◽  
Plant Viruses ◽  
Aggregation Process ◽  
Microscopic Technique ◽  
Fecal Material ◽  
Present Communication ◽  
Number Of Particles

Studies of rotavirus particles in humans, monkeys and various non-primates with acute gastroenteritis have involved detection of virus in fecal material by electron microscopy. The EM techniques most commonly employed have been the conventional negative staining (Fig. 1) and immune aggregation (Fig. 2) procedures. Both methods are somewhat insensitive and can most reliably be applied to samples containing large quantities of virus either naturaLly or as a result of concentration by ultracentrifugation. The formation of immune complexes by specific antibody in the immune aggregation procedures confirms the rotavirus diagnosis, but the number of particles per given microscope field is effectively reduced by the aggregation process. In the present communication, we describe use of an on-grid immunoelectron microscopic technique in which rotavirus particles are mounted onto microscope grids that were pre-coated with specific antibody. The technique is a modification of a method originalLy introduced by Derrick (1) for studies of plant viruses.

Studies on Magnetron-Sputtered NiO/Si3N4 Thin Films

2018 ◽  
Vol 17 (03) ◽  
pp. 1760039
Author(s):  
K. M. Dhanisha ◽  
M. Manoj Christopher ◽  
M. Abinaya ◽  
P. Deepak Raj ◽  
M. Sridharan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Smooth Surface ◽  
Deposition Time ◽  
Si Substrate ◽  
X Ray ◽  
Coating Time ◽  
Deposited Films ◽  
Nio Films ◽  
Scanning Electron

The present work deals with NiO/Si3N4 layers formed by depositing nickel oxide (NiO) thin films over silicon nitrate (Si3N[Formula: see text] thin films. NiO films were coated on Si3N4-coated Si substrate using magnetron sputtering method by changing duration of coating time and were analyzed using X-ray diffractometer, field emission-scanning electron microscopy, UV–Vis spectrophotometer and four-point probe method to study the influence of thickness on physical properties. Crystallinity of the deposited films increases with increase in thickness. All films exhibited spherical-like structure, and with increase in deposition time, grains are coalesced to form smooth surface morphology. The optical bandgap of NiO films was found to decrease from 3.31[Formula: see text]eV to 3.22[Formula: see text]eV with upsurge in the thickness. The film deposited for 30[Formula: see text]min exhibits temperature coefficient resistance of [Formula: see text]1.77%/[Formula: see text]C as measured at 80[Formula: see text]C.

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.

scholarly journals Low Vacuum Filtration Method as an Alternative Extracellular Vesicle Concentration Method: Comparison with Ultracentrifugation and Differential Centrifugation

2020 ◽  
Author(s):  
Anna Drożdż ◽  
Agnieszka Kamińska ◽  
Magdalena Surman ◽  
Agnieszka Gonet-Surówka ◽  
Robert Jach ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Culture Media ◽  
Membrane Surface ◽  
Method Comparison ◽  
Environmental Scanning Electron Microscopy ◽  
Drug Carriers ◽  
Differential Centrifugation ◽  
Isolation Method ◽  
Filtration Method ◽  
Vacuum Filtration

Recent years brought great focus in the field of development of extracellular vesicles (EVs) based drug-delivery systems. Considering possible applications of EVs as a drug carriers the isolation process is a crucial step. To solve problems related with EV isolation, we created and validated a new EVs isolation method – Low Vacuum Filtration (LVF) and compared it with two commonly applied procedures - differential centrifugation (DC) and ultracentrifugation (UC). EVs isolated from endothelial cells culture media have been characterized by a) transmission electron microscopy (TEM) b) nanoparticle tracking analysis (NTA), c) western blot and d) Fourier-Transform Infrared Spectroscopy (FTIR). Additionally, the membrane surface have been imaged with Environmental Scanning Electron Microscopy (ESEM). We showed that LVF is reproducible and efficient method for EVs isolation form conditioned media. Additionally, we observed correlation between ATR-FTIR spectra quality and the EVs and proteins concentration. ESEM imaging confirmed that actual pore diameter are close to the values calculated theoretically. LVF method is an easy, fast and inexpensive EVs isolation method which allows for isolation of both ectosomes and exosomes from high volume sources with good repeatability. We think that it could be an efficient alternative for commonly applied methods.

Isolation of plasma membranes of smooth muscle cells of the rabbit small intestine

1984 ◽  
Vol 97 (1) ◽  
pp. 134-136 ◽  
Author(s):  
V. K. Rybal'chenko ◽  
P. V. Pogrebnoi ◽  
T. G. Gruzina ◽  
V. I. Karamushka
Keyword(s):  
Smooth Muscle ◽  
Small Intestine ◽  
Smooth Muscle Cells ◽  
Plasma Membranes ◽  
Muscle Cells ◽  
Rabbit Small Intestine

The ultrastructure of the cardiac Purkinje strand in the dog: a morphometric analysis

1983 ◽  
Vol 217 (1207) ◽  
pp. 191-213 ◽  
Keyword(s):  
Electron Microscopy ◽  
Electrical Properties ◽  
Connective Tissue ◽  
Surface Area ◽  
Series Resistance ◽  
Membrane Surface ◽  
Light And Electron Microscopy ◽  
Total Surface Area ◽  
Membrane Surface Area ◽  
Extracellular Ions

Purkinje strands from both ventricles of adult mongrel dogs were excised, and electrical properties were studied by the voltage-clamp technique. The strands were then examined with light and electron microscopy and structural properties were analysed by morphometric techniques. The canine Purkinje strand contains (by volume) about 28% myocyte and 55% dense outer connective tissue. The remainder of the volume is taken up by the inner shell of loosely packed connective tissue within 10 μm of a myocyte membrane. These volume fractions vary considerably from one strand to another. Clefts less than 10 μm wide occupy 18% of the myocyte volume and clefts less than 1 μm wide occupy 1%. The membrane surface area of the myocytes can be divided into three categories by reference to the size of the adjacent cleft. About 47.8% of the membrane surface area faces clefts wider than 1 μm, another 22.2% faces clefts between 0.1 and 1 μm wide, and the final 30% faces clefts less than 0.1 μm wide. The surface area facing the narrowest clefts (less than 0.1 μm wide) is divided between nexuses 3%, desmosomes 10%, and unspecialized membrane 17% (each figure is expressed as a percentage of the total surface area of myocyte membrane). The canine Purkinje strand has a more favourable anatomy than the sheep Purkinje strand for most physiological experiments. We expect that the complicating effects of series resistance and change in the concentration of extracellular ions will be much smaller than in sheep strands, but still not negligible.

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