Homogenization of the Cell Cytoplasm: The Calcium Bidomain Equations

2006 ◽  
Vol 5 (4) ◽  
pp. 1045-1062 ◽  
Author(s):  
Pranay Goel ◽  
James Sneyd ◽  
Avner Friedman
Keyword(s):  
Cell Cytoplasm ◽  
Bidomain Equations

3-D examination of the cytoskeletal sheets of mammalian eggs

1992 ◽  
Vol 50 (1) ◽  
pp. 914-915
Author(s):  
Carolyn A. Larabell ◽  
David G. Capco ◽  
G. Ian Gallicano ◽  
Robert W. McGaughey ◽  
Karsten Dierksen ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Somatic Cells ◽  
Freeze Fracture ◽  
Blastocyst Stage ◽  
Cell Cytoplasm ◽  
Planar Structures ◽  
Cytoskeletal Network ◽  
Entire Cell ◽  
Cytoskeletal Networks ◽  
Mammalian Eggs

Mammalian eggs and embryos contain an elaborate cytoskeletal network of “sheets” which are distributed throughout the entire cell cytoplasm. Cytoskeletal sheets are long, planar structures unlike the cytoskeletal networks typical of somatic cells (actin filaments, microtubules, and intermediate filaments), which are filamentous. These sheets are not found in mammalian somatic cells nor are they found in nonmammalian eggs or embryos. Evidence that they are, indeed, cytoskeletal in nature is derived from studies demonstrating that 1) the sheets are retained in the detergent-resistant cytoskeleton fraction; 2) there are no associated membranes (determined by freeze-fracture); and 3) the sheets dissociate into filaments at the blastocyst stage of embryogenesis. Embedment-free sections of hamster eggs viewed at 60 kV show sheets running across the egg cytoplasm (Fig. 1). Although this approach provides excellent global views of the sheets and their reorganization during development, the mechanism of image formation for embedment-free sections does not permit evaluation of the sheets at high resolution.

Halophilic bacteria are able to decontaminate dichlorvos, a pesticide, from saline environments

2007 ◽  
Vol 2 (4) ◽  
pp. 563-573 ◽  
Author(s):  
Tatiana Oncescu ◽  
Petruta Oancea ◽  
Madalin Enache ◽  
Gabriela Popescu ◽  
Lucia Dumitru ◽  
...  
Keyword(s):  
Diffusion Process ◽  
Rate Constant ◽  
Permeability Coefficient ◽  
Halophilic Bacteria ◽  
Chemical Degradation ◽  
Cell Cytoplasm ◽  
Organic Osmolyte ◽  
Organophosphorous Pesticide ◽  
High Degree ◽  
Saline Solutions

AbstractDichlorvos (DDVP) is an organophosphorous pesticide with a high degree of dangerous effect towards the environment. We have investigated the growth and susceptibility to DDVP of halophilic bacteria isolated from Romanian salt lakes. The growth of four strains was affected by DDVP, which may be correlated with the rate constant values of DDVP disappearance from the saline solutions. This is due not to a chemical degradation in solution but to the diffusion process and namely DDVP penetration into the cell cytoplasm by an “organic-osmolyte” mechanism. The permeability coefficient P was calculated.

scholarly journals Low viscosity in the aqueous domain of cell cytoplasm measured by picosecond polarization microfluorimetry.

1991 ◽  
Vol 112 (4) ◽  
pp. 719-725 ◽  
Author(s):  
K Fushimi ◽  
A S Verkman
Keyword(s):  
Free Water ◽  
Fluid Phase ◽  
Rotational Correlation Time ◽  
Cell Cytoplasm ◽  
Intact Cells ◽  
Low Viscosity ◽  
3T3 Fibroblasts ◽  
Anisotropy Decay ◽  
Novel Method ◽  
Swiss 3T3 Fibroblasts

Information about the rheological characteristics of the aqueous cytoplasm can be provided by analysis of the rotational motion of small polar molecules introduced into the cell. To determine fluid-phase cytoplasmic viscosity in intact cells, a polarization microscope was constructed for measurement of picosecond anisotropy decay of fluorescent probes in the cell cytoplasm. We found that the rotational correlation time (tc) of the probes, 2,7-bis-(2-carboxyethyl)-5-(and-6-)carboxyfluorescein (BCECF), 6-carboxyfluorescein, and 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) provided a direct measure of fluid-phase cytoplasmic viscosity that was independent of probe binding. In quiescent Swiss 3T3 fibroblasts, tc values were 20-40% longer than those in water, indicating that the fluid-phase cytoplasm is only 1.2-1.4 times as viscous as water. The activation energy of fluid-phase cytoplasmic viscosity was 4 kcal/mol, which is similar to that of water. Fluid-phase cytoplasmic viscosity was altered by less than 10% upon addition of sucrose to decrease cell volume, cytochalasin B to disrupt cell cytoskeleton, and vasopressin to activate phospholipase C. Nucleoplasmic and peripheral cytoplasmic viscosities were not different. Our results establish a novel method to measure fluid-phase cytoplasmic viscosity, and indicate that fluid-phase cytoplasmic viscosity in fibroblasts is similar to that of free water.

The RhopH complex is transferred to the host cell cytoplasm following red blood cell invasion by Plasmodium falciparum

2008 ◽  
Vol 160 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Laetitia Vincensini ◽  
Gamou Fall ◽  
Laurence Berry ◽  
Thierry Blisnick ◽  
Catherine Braun Breton
Keyword(s):  
Plasmodium Falciparum ◽  
Blood Cell ◽  
Host Cell ◽  
Cell Invasion ◽  
Red Blood Cell ◽  
Cell Cytoplasm ◽  
Host Cell Cytoplasm

G-proteins in mammalian gametes: an immunocytochemical study

1988 ◽  
Vol 91 (1) ◽  
pp. 21-31
Author(s):  
N.B. Garty ◽  
D. Galiani ◽  
A. Aharonheim ◽  
Y.K. Ho ◽  
D.M. Phillips ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
G Protein ◽  
G Proteins ◽  
Cumulus Cells ◽  
Bovine Brain ◽  
Regulatory Proteins ◽  
Immunocytochemical Study ◽  
Cell Cytoplasm ◽  
Sperm Tail ◽  
Immunoreactive Material

The presence of transductory GTP(G)-regulatory proteins in mammalian gametes has been examined by indirect fluorescence immunocytochemistry. Using rabbit antisera to bovine rod beta gamma-transducin (RA beta gamma T), bovine rod holotransducin (AS-1), bovine rod alpha-transducin (RA alpha T), synthetic bovine rod alpha-transducin C-terminal decapeptide (AS-6), bovine brain alpha 39Go (RA alpha 39), and two mouse monoclonal antibodies raised against frog retinal transducin (4A), and rat brain beta-tubulin, we demonstrated the presence of corresponding immunoreactive material in both rat oocytes and bovine ejaculated sperm. Immunostaining in the oocyte was evenly distributed on the oolemma, excluding the cell cytoplasm and zona pellucida. Immunoreactive material was also present in the cumulus cells that encapsulate the oocyte. In contrast, the immunofluorescence corresponding to transductory G-proteins was confined in sperm to functionally defined regions in the head and tail, in a manner specific for each antibody. While RA beta gamma T, AS-1 and RA alpha 39 all stained the entire acrosome, AS-6 and RA alpha T stained only the acrosomal tip. Monoclonal antibody 4A stained the midpiece exclusively and anti-rat betaq-tubulin (a structural G-protein) stained the full length of the sperm tail. The existence of several G-protein types in mammalian gametes suggests their possible involvement in the regulation of various effector systems, in a manner reminiscent of somatic cells. The unique situation in sperm, where different G-proteins show distinct and specific patterns of distribution, further suggests their association with various effector systems in discrete functional domains.

EXPRESIÓN DE P53 EN CULTIVO DE CÉLULAS MADRE AISLADAS A PARTIR DE QUISTE RADICULAR INFLAMATORIO

SCIENTIARVM ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. 33-36
Author(s):  
Francis Wendell Jácobo Valdivia ◽  
◽  
Julio Cesar Bernabé Ortiz ◽  
Javier Valero Quispe ◽  
Ivo Palomino Valverde ◽  
...  
Keyword(s):  
Stem Cells ◽  
Oral Cavity ◽  
Surgical Intervention ◽  
Positive Response ◽  
P53 Gene ◽  
Cell Cytoplasm ◽  
Inflammatory Lesions

The inflammatory root cyst is defined as one of the most frequent inflammatory lesions in the oral cavity where it normally involves the apex of the dental roots, giving frequent pathognomonic clinical and radiological characteristics. The objective of this investigation was to determine the expression of p53 in the culture of isolated stem cells from the inflammatory root cyst. In its methodology, the report of a case of a 69-year-old patient was presented, who underwent surgical intervention to extract pieces 11 and 12, from which the sample was obtained for the isolation and culture of the cyst stem cells. periapical inflammatory, obtaining elongated, flat cells with fibroblastic appearance from day 4 and staining with markers for p53 giving a positive response in the evidence of the p53 gene both in the cytoplasm and in the nucleus of these stem cells. Finally, cells can be obtained from the inflammatory root cyst from 4 to 25 days with the use of a modified protocol, in the end, as a contribution to this article, the evidence of the p53 gene is provided both in the nucleus and in the cell cytoplasm. Keywords: Root cyst, p53 gene, stem cells, isolation and culture

Evidence against electrophoresis as the principal mode of protein transport in vitellogenic ovarian follicles of Drosophila

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 279-288
Author(s):  
J. Bohrmann ◽  
H. Gutzeit
Keyword(s):  
Nurse Cell ◽  
Protein Transport ◽  
Exchange Chromatography ◽  
Heterologous Proteins ◽  
Nurse Cells ◽  
Cell Cytoplasm ◽  
Two Dimensional Gel Electrophoresis ◽  
Electrophoretic Transport ◽  
Indicator Dyes

Charged cell constituents in polytrophic insect follicles are thought to be transported in the nurse cell-oocyte syncytium by way of electrophoresis. This concept, proposed by Woodruff & Telfer (1980) was based on electrophysiological data and microinjection of heterologous proteins using Hyalophora follicles. By microinjecting fluorescently labelled acidic and basic proteins into the nurse cells or oocyte of vitellogenic Drosophila follicles, we failed to obtain evidence for charge-dependent migration of these molecules. We have also analyzed the proteins of nurse cells and oocyte on isoelectric focusing gels, by means of two-dimensional gel electrophoresis, and by ion exchange chromatography to see if basic or acidic proteins accumulate in vivo in nurse cells and oocyte, respectively. For the bulk of the follicular proteins we found no accumulation. Further evidence against an electrophoretic transport system in Drosophila was obtained by estimating the intracellular pH from the colour of indicator dyes microinjected into the follicles; the results indicate that the pH in the nurse cell cytoplasm is lower than that in the ooplasm. According to the model developed for Hyalophora, electrophoretic transport would be favoured by high pH in the nurse cell cytoplasm.

The influence of the nucleus on sequential determination in frog ectoderm following induction by lithium ion

Development ◽  
1969 ◽  
Vol 21 (3) ◽  
pp. 383-390
Author(s):  
Krystyna D. Ansevin
Keyword(s):  
Cell Nucleus ◽  
Cellular Differentiation ◽  
Intrinsic Factor ◽  
Lithium Ion ◽  
Morphological Differentiation ◽  
Competent Cell ◽  
Cell Cytoplasm ◽  
Sequential Determination ◽  
Complex Sequence ◽  
Short Period

It appears certain that the process of cellular differentiation is an outcome of interactions between the cell nucleus and cell cytoplasm. Differentiation of embryonic amphibian ectoderm involves two fairly distinct phases: during the first short period an inductor (or some intrinsic factor, if an inductor is absent) determines the course of future differentiation in a multipotential cell; during the second, longer interval of time presumably a complex sequence of reactions leads to physiological and morphological differentiation. Little is known about the nature of reactions which take place during the first phase when the cells become developmentally determined by the inductor. It appears that the first step in translation of the inductive instruction in the competent cell is accomplished during the first 2 or 3 h following the treatment with the inductor (Ansevin, 1966). The step is not actinomycin-sensitive (Ansevin, 1965), as was shown by cells that completely recovered after actinomycin treatment (in conditions when it was unlikely that they could have failed to take up some inhibitor).

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