In Vitro Studies of Microtubule Structures Using the Mac Mode AFM

1999 ◽  
Vol 5 (S2) ◽  
pp. 1006-1007
Author(s):  
J. Zhu ◽  
J. Hartman ◽  
R. Case ◽  
S. Rice ◽  
R. Vale
Keyword(s):  
Structural Unit ◽  
Electron Microscopic ◽  
Physiological Conditions ◽  
Atomic Force ◽  
Chromosome Separation ◽  
Cytoplasmic Microtubules ◽  
Dynamic Structures ◽  
Microscopic Techniques ◽  
Β Tubulin

Microtubules are long, hollow, stiff polymers that extend throughout the cytoplasm. They are involved in such diverse functions as governing the location of membrane-bounded organelles and chromosome separation during mitosis. The basic structural unit is tubulin, which is a heterodimer consisting of two closely related and tightly linked globular polypeptides called α and β-tubulin. Alternating α and β tubulin subunits form protofilaments, 13 of which bundle around a central core to form microtubule. The detailed structures of cytoplasmic microtubules have been studied extensively using various electron microscopic techniques. As microtubules are dynamic structures in constant transitions between growing and shrinking phases, it would be extremely interesting to investigate the structural organization of the subunit tubulin molecules in a buffer close to physiological conditions. With its high resolution and ability to image in fluid, atomic force microscope (AFM) makes it possible to study the biological structures in a native environment.

scholarly journals Silver Nanoparticles Embedded in Natural Rubber Films: Synthesis, Characterization, and Evaluation ofIn VitroToxicity

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Caroline S. Danna ◽  
Dalita G. S. M. Cavalcante ◽  
Andressa S. Gomes ◽  
Leandra E. Kerche-Silva ◽  
Eidi Yoshihara ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Natural Rubber ◽  
Chinese Hamster ◽  
Cell Lineage ◽  
Microscopic Analysis ◽  
Visible Spectrum ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force

Natural rubber (NR) films can reduce silver metal ions forming embedded metal nanoparticles, a process that could be described as green synthesis. The NR films acting as a reactor generate and incorporate silver nanoparticles (AgNPs). Organic acids and amino acids play a crucial role in the formation of AgNPs. The plasmon extinction obtained in the UV-visible spectrum shows the presence of nanoparticles in the film after dipping the NR film into a solution of silver nitrate at 80°C. Electron microscopic analysis confirms the presence of AgNPs in the NR film and characterization by atomic force microscopy shows a change in the roughness of the NR film with AgNPs. In addition, our preliminary results fromin vitrotoxicity studies (MTT and comet assays) of the NR films and NR films with silver nanoparticles (NR/Ag) show that they are not toxic to cell lineage CHO-K1 (cells from the ovary of a Chinese hamster), an important result for potential medical applications.

scholarly journals Comparison of surface iodination methods by electron microscopic autoradiography applied in vitro to different life-stages of Dipetalonema vitae (Filarioidea)

Parasitology ◽  
1982 ◽  
Vol 85 (3) ◽  
pp. 559-565 ◽  
Author(s):  
W. Baschong ◽  
W. Rudin
Keyword(s):  
Life Stages ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Physiological Conditions ◽  
Chloramine T ◽  
Electron Microscopical ◽  
Dipetalonema Viteae

Different stages of Dipetalonema viteae (males, females, microfilariae, and 3rd-stage larvae) have been iodinated in vitro under physiological conditions by chloroglycoluril, lactoperoxidase or chloramine T. The concentrations of the catalysts were correlated with the viability of the worms. Localization of the label with the different iodination methods had been visualized by electron microscopical autoradiography. Chloroglycoluril-mediated iodination is predominantly localized on the filarial cuticle. Lactoperoxidase-catalysed iodination is less specific and chloramine T catalyses iodination in a gradient decreasing from the cuticle to inner structures. It is necessary to visualize the labelling by electron microscopical autoradiography prior to biochemical and immunological experiments to avoid the extraction of structures iodinated by leakage of the catalyst into sub-cuticular regions.

Behavioural properties of chick somitic mesoderm and lateral plate when explanted in vitro

Development ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 41-58
Author(s):  
Ruth Bellairs ◽  
P. A. Portch ◽  
E. J. Sanders
Keyword(s):  
Time Lapse ◽  
Lateral Plate Mesoderm ◽  
General Shape ◽  
Electron Microscopic ◽  
Lateral Plate ◽  
Plastic Substrates ◽  
Different Types ◽  
Somitic Mesoderm ◽  
Microscopic Techniques

Tissue culture, time-lapse cinematographic and electron microscopic techniques have been used to study the properties of chick mesoderm at several stages of differentiation. Lateral plate, unsegmented mesoderm (segmental plate), and newly formed somites were dissected from stage-12 embryos, whilst dermo-myotomes and sclerotomes were dissected from stage-18 embryos. Each type of mesoderm was found to exhibit a characteristic pattern of behaviour. The explants from the unsegmented mesoderm, from the newly formed somites and from the older embryos could be placed in a developmental sequence; with increasing differentiation they settled and spread on the substrate more readily, whether explanted as pieces of tissue or as individual cells, and it was concluded that this implied an increased adhesion to the substrate. Similarly, with increasing differentiation, the cells segmented at a faster rate. No significant differences could be discerned in the internal structure of the different types of cells, although differences in the general shape were apparent. The lateral plate mesoderm cells, which bear some resemblances to the unsegmented mesoderm cells in the embryo, also show some morphological resemblances to them in vitro. However, the lateral plate cells had a much greater success in attaching to glass or plastic substrates. They were also found to have the highest speed of locomotion of all the tissues studied, whereas the unsegmented had the lowest. It is concluded therefore, that although cells may look similar to one another morphologically, their behaviour may differ greatly, probably because they are already partially determined.

Effects of Colchicine on the Golgi Complex and Gerl of Cultured Rat Peritoneal Macrophages and Epiphyseal Chondrocytes

1980 ◽  
Vol 45 (1) ◽  
pp. 41-58
Author(s):  
JOHAN THYBERG ◽  
ANDRZEJ PIASEK ◽  
STANISLAW MOSKALEWSKI
Keyword(s):  
Golgi Complex ◽  
Structural Integrity ◽  
Cell Types ◽  
Peritoneal Macrophages ◽  
Electron Microscopic ◽  
Thiamine Pyrophosphatase ◽  
Cytoplasmic Microtubules ◽  
The Individual ◽  
Functionally Diverse

Thioglycollate-elicited rat peritoneal macrophages and epiphyseal chondrocytes were cultured in vitro, treated with colchicine, and then studied by electron-microscopic and cytochemical techniques. Colchicine, but not lumicolchicine, caused disappearance of cytoplasmic microtubules and breakup of the Golgi complex with spreading of its dictyosomes from a well defined juxta nuclear area throughout the cytoplasm. There was also an altered distribution of lysosomes, which oriented themselves close to the dictyosomes both in controland colchicine-treated cells. Further, the structure of the individual dictyosomes was changed, especially in the chondrocytes. GERL equivalents were observed in control cells but were difficult to detect after exposure to colchicine. Reaction product for thiamine pyrophosphatase was found in narrow cisternae on the inner side of the dictyosomes in control cells but invacuole-like structures in colchicine-treated cells. Reaction product for acid phosphatase was present in GERL equivalents and lysosomes in control cells but mainly in lysosomes incolchicine-treated cells. Nevertheless, the total specific activities of these enzymes as well as of 5′-nucleotidase, a plasma membrane marker, remained unaffected by the drug treatment. These observations show that cytoplasmic microtubules play an important and, in many respects similar, cytoskeletal role in two so functionally diverse cell types as macrophages and chondrocytes. They are particularly important for the structural integrity of the Golgi complex, which in both cells is normally organized in the area around the centrioles, from which numerous microtubules radiate into the cytoplasm. The observations further suggest that GERL is an integrated part of the Golgi complex in these cells.

The Function of the Basal Filaments in the Parietal Layer of Bowman's Capsule

1973 ◽  
Vol 51 (2) ◽  
pp. 53-60 ◽  
Author(s):  
W. A. Webber ◽  
W. T. Wong
Keyword(s):  
Cell Types ◽  
Electron Microscopic ◽  
Structural Framework ◽  
Renal Cortical Tissue ◽  
Attachment Mechanism ◽  
Relationship Of ◽  
Bowman's Capsule ◽  
Microscopic Techniques

A number of cell types in the nephron have been known for some time to contain basally located filaments demonstrable by a variety of both light and electron microscopic techniques.]t has been proposed that these filaments may provide a contractile mechanism which would have implications for the control of renal function. One site in which these filaments have been observed is in the parietal layer of Bowman's capsule. The present study was designed to see if contraction of this layer of cells could be demonstrated and if so whether the basal filaments appeared to play a role in the process. Renal cortical tissue was fixed both in vivo and in vitro in the presence and absence of histamine, adrenaline, and acetylcholine and examined by conventional electron microscopic techniques. Basal folding of the cell membrane was observed particularly in the adrenaline-treated tissue and was interpreted as reflecting a conformational change in the cell such as might be expected with contraction. The relationship of this folding, however, to the arrangement of the basal filaments was such as to suggest that contraction of the filaments was not responsible for the folding observed. Alternative roles for the fibrils either as a structural framework or as a component in an attachment mechanism of the cells to the underlying basement membrane were therefore proposed.

Force Modulation Elasticity Mapping of Plastic-embedded, Thin-sectioned Skeletal Muscle

2001 ◽  
Vol 7 (1) ◽  
pp. 32-38
Author(s):  
Boris B. Akhremitchev ◽  
Henry G. Brown ◽  
Scott R. Graner ◽  
Gilbert C. Walker
Keyword(s):  
Skeletal Muscle ◽  
Atomic Force Microscopy ◽  
Biological Material ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Force Microscopy ◽  
Force Modulation ◽  
Atomic Force ◽  
The Difference ◽  
Microscopic Techniques

AbstractWe have been researching the capability of atomic force microscopy to reveal nontopographic properties of tissue embedded in plastic and sectioned with standard electron microscopic techniques. We present topography and elasticity maps of plastic-embedded, thin sections of muscle tissue. The images show topography correlated with the normal repeating structure of the sarcomere. Elasticity mapping using force modulation revealed contrast between the actin- and myosin-rich areas. We attribute the observed contrast in elasticity to the difference in local concentrations of biological material in embedding plastic.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Polarity Determination in Sphalerite and Wurtzite Structures

1990 ◽  
Vol 48 (2) ◽  
pp. 500-501
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Opposite Polarity ◽  
Single Domain ◽  
Polar Material ◽  
Electron Microscopic ◽  
Dynamical Interaction ◽  
X Ray ◽  
Polarity Determination ◽  
The Absolute ◽  
Microscopic Techniques

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

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