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Results 401 - 450 of 1934
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Paterson Christopher A - - 2004
In the lens, different cells appear to be specialized such that some have a high capacity for energy-dependent ion transport while others do not. This short review describes the distribution of functional Na,K-ATPase activity and Ca-ATPase activity in the lens. Movement of ions in the extracellular space between lens fibers, ...
Pedrosa Rui - - 2004
The sensitivity of the Cl(-)/HCO(3)(-) exchanger to dopamine D(1)- and D(2)-like receptor stimulation in immortalized renal proximal tubular epithelial cells from the spontaneous hypertensive rat (SHR) and Wistar-Kyoto rat (WKY) was examined. The activity of the Cl(-)/HCO(3)(-) exchanger (in pH U/s) in SHR cells (0.00191) was greater than in WKY ...
Sennoune Souad R - - 2004
Tumor cells thrive in a hypoxic microenvironment with an acidic extracellular pH. To survive in this harsh environment, tumor cells must exhibit a dynamic cytosolic pH regulatory system. We hypothesize that vacuolar H(+)-ATPases (V-ATPases) that normally reside in acidic organelles are also located at the cell surface, thus regulating cytosolic ...
Rouzaire-Dubois Béatrice - - 2004
The homeostasis of the central nervous system is highly controlled by glial cells and is dramatically altered in the case of glioma. In this respect, the complex connection between cell size and division is of particular importance and needs clarifying. In order to investigate this connection, cell number and volume ...
Leguen Isabelle - - 2004
The effect of hypotonic shock on cultured pavement gill cells from freshwater (FW)- and seawater (SW)-adapted trout was investigated. Exposure to 2/3rd strength Ringer solution produced an increase in cell volume followed by a slow regulatory volume decrease (RVD). The hypotonic challenge also induced a biphasic increase in cytosolic Ca(2+) ...
Yamamoto Shintaro - - 2004
The cell-volume regulation by swelling-activated Cl- current (I(Cl,swell)) was studied in guinea pig ventricular myocytes, using a microscopic video-image analysis. We have previously shown that in ventricular cells depolarized in high-K+ ([K+]o>45 mM) solution, an activation of the cyclic AMP-dependent Cl- current (I(Cl,cAMP)) leads to cell swelling. We first investigated ...
Nakagawa Ryuji - - 2004
BACKGROUND: It would be beneficial to be able to predict the cord blood (CB) cell yield from volunteer donors before cell processing. STUDY DESIGN AND METHODS: The maternal and neonatal factors that influence the total nucleated cell (TNC), CD34+ cell, and CFU-GM yields in CB collected for the Chugoku-Shikoku Cord ...
Shibata Y - - 2004
Implant surfaces should be modified to achieve excellent cell compatibility as well as antibacterial activity. Our previous study demonstrated that titanium plates anodized by being discharged in NaCl (Ti-Cl) exhibited high antibacterial activity. Since Ti-Cl was prepared with a NaCl solution, we hypothesized that Ti-Cl would exhibit low toxicity toward ...
Hawkings Guy S - - 2004
Mitochondria-rich cells (MR cells) of the gills of rainbow trout undergo changes in relative distribution and biochemical function during acclimation to partial-strength (10 per thousand ) and full-strength (30 per thousand ) seawater. In isolated total gill cells, Na(+)/K(+)-ATPase activity increased fivefold and H(+)-ATPase activity decreased fourfold when trout were ...
Zonia Laura - - 2004
Pollen tube cell volume changes rapidly in response to perturbation of the extracellular osmotic potential. This report shows that specific phospholipid signals are differentially stimulated or attenuated during osmotic perturbations. Hypo-osmotic stress induces rapid increases in phosphatidic acid (PA). This response occurs starting at the addition of 25% (v/v) water ...
Golstein P E - - 2004
This study characterized the membrane permeability to cAMP in a cell line derived from the rat colon (CC531(mdr+)) by comparison of fluxes of 3H-cAMP, 3H-8-bromo-cAMP, 3H-taurine, 3H-adenosine and 3H-5'AMP under various experimental conditions including cell membrane depolarization and hypotonic cell swelling. Cell volume was modified by changing the osmolality and ...
Ferland, Kevin K., 1969-
"Volume 167, number 794 (fourth of 5 numbers)"
Okada Yasunobu - - 2004
All animal cell types have an appropriate volume. Even under physiological conditions of constant extracellular osmolarity, cells must regulate their volume. Cell volume is subjected to alterations because of persistent physicochemical osmotic load resulting from Donnan-type colloid osmotic pressure and of cell activity-associated changes in intracellular osmolarity resulting from osmolyte ...
Lambert Ian Henry - - 2004
Change in the intracellular concentration of osmolytes or the extracellular tonicity results in a rapid transmembrane water flow in mammalian cells until intracellular and extracellular tonicities are equilibrated. Most cells respond to the osmotic cell swelling by activation of volume-sensitive flux pathways for ions and organic osmolytes to restore their ...
Lin Chia-Hao - - 2004
Changes in expression of Na, K-ATPase (NKA) and morphometry of mitochondrion-rich (MR) cells in gills of tilapia were investigated on a 96-hr time course following transfer from seawater (SW) to fresh water (FW). A transient decline in plasma osmolality and Na+, Cl- concentrations occurred from 3 hrs onward. Gills responded ...
Guadalupe Cabral M - - 2004
AIMS: The objective of this work was to examine adaptative responses occurring in Saccharomyces cerevisiae following exposure to the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA). METHODS AND RESULTS: The exposure of a yeast cell population to MCPA concentrations of moderate toxicity led to a period of latency before eventual resumption of inhibited ...
Ordaz Benito - - 2004
A decrease in external osmolarity results in cell swelling and the immediate activation of a mechanism to restore cell volume, known as regulatory volume decrease (RVD). When exposed to a gradual osmolarity decrease (GODE), some cells do not swell. This reflects the operation of an active regulatory process known as ...
Amemiya Morimasa - - 2004
BACKGROUND/AIMS: Chronic hypokalemia increases NHE3 activity in OKP cells. The aim of the present study was to determine whether an autocrine mechanism is involved in this activation. METHODS: After incubation of OKP cells in normal-K(+) and low-K(+) media for 24 h, the potassium concentration in the low-K(+) media was adjusted ...
da Cunha Lima Marta - - 2004
The presence of morphological differences in the sublingual gland of male and female adult rats was determined by morphometry. Absolute and relative glandular mass was 21% lower and 31% higher, respectively, in females than in males. The fractions of glandular volume occupied by the mixed acini, intercalated ducts and striated ...
Capaldo A - - 2004
The existence of paracrine control of steroidogenic activity by adrenochromaffin cells in Triturus carnifex was investigated by in vivo noradrenaline (NA) administration. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the serum levels of aldosterone, NA, and adrenaline (A). ...
Srinivas S P - - 2004
PURPOSE: Hyposmolar perfusion of intact trabecular meshwork (TM) induces a decrease in its hydraulic conductivity (Lp). However, exposure to agents that elevate intracellular cAMP in TM cells increases Lp. Since volume of TM cells could directly influence porosity of the TM and hence Lp, this study has investigated changes in ...
Orlov Sergei N - - 2004
Several research teams have proposed that shrinkage and swelling in cells undergoing apoptosis and oncosis are not only the earliest morphological markers of the two modes of cell death but are also obligatory steps in the development of the death machinery. We examined this hypothesis as well as the role ...
Sardini Alessandro - - 2003
Maintenance of a constant volume is essential for normal cell function. Following cell swelling, as a consequence of reduction of extracellular osmolarity or increase of intracellular content of osmolytes, animal cells are able to restore their original volume by activation of potassium and chloride conductances. The loss of these ions, ...
Ritz P - - 2003
There is paramount evidence to suggest the importance of cell volume changes for the regulation of cell function, including protein metabolism. Among many other effects, cell swelling inhibits proteolysis and stimulates protein synthesis. However, most of the data pertinent to this theory relate to in vitro experiments. This paper reviews ...
Elias Emmanuel - - 2003
Topoisomerase I (Topo I) is mostly known for its role in DNA relaxation, which is required for duplication and transcription. Topo I acts as a protein kinase mainly directed to the mRNA splicing factor SC35. Camptothecin is one of the specific Topo I inhibitors and is effective on the two ...
Dubois Jean-Marc - - 2004
Ion channels and cell volume control participate in a wide variety of cellular functions, including cell proliferation. According to the "pump-leak model" or the "double Donnan system", the cell volume is constant in physiological medium so long as the cell metabolism and the Na-K pump are not inhibited and the ...
Shiima-Kinoshita Chisa - - 2004
Single bronchiolar ciliary cells were isolated from rat lungs. The beta(2)-adrenergic regulation of ciliary beat frequency (CBF) was studied using video-optical microscopy. Terbutaline (a beta(2)-adrenergic agonist) increased CBF in a dose-dependent manner, and it also decreased the volume of the ciliary cells. These terbutaline actions were inhibited by a PKA ...
Davis Cristina E - - 2004
Many cell types regulate their volume in response to extracellular tonicity changes through a complex series of adaptive mechanisms. Several methods that are presently used to measure cell volume changes include Coulter counters, fluorescent techniques, electronic impedance, and video microscopy. Although these methods are widely used and accepted, there are ...
Wehner Frank - - 2003
In whole-cell recordings on single HeLa cells, the hypertonic activation of a cation conductance with a selectivity ratio P(Na):P(Li):P(K):P(Cs):P(NMDG):P(Ca):P(Cl) of 1.00:0.86:0.84:0.56:0.10:0.07:0.15 was observed. This (non-selective) cation conductance was reduced to 59 and 30% of maximal stimulation by Gd(3+) and flufenamate, respectively, but it was insensitive to amiloride (with each compound ...
Srinivas S P - - 2003
Light scattering is an empirical technique employed to measure rapid changes in cell volume. This study describes a new configuration for the method of light scattering and its corroboration by measurements of cell height (as a measure of cell volume). Corneal endothelial cells cultured on glass cover-slips were mounted in ...
Brindikova Tatyana A - - 2003
Purinergic inhibition of Na-K-Cl cotransport has been noted in various renal epithelial cells derived from the collecting tubule, including Madin-Darby canine kidney (MDCK) cells. In recent studies, we have observed purinergic inhibition of Na-K-Cl cotransport in C11-MDCK subclones (alpha-intercalated-like cells). Interestingly, Na-K-Cl cotransport activity was also detected in C7-MDCK subclones ...
Belsey Mark J - - 2003
FACS analysis and [14C]-taurine efflux were used to determine whether activation of the volume-sensitive organic osmolyte/anion channel plays a role in cell cycle progression. This was achieved by examining the effects of a collection of (i) H(1) antagonists and tricyclic antidepressants with a known inhibitory effect on cell cycle progression, ...
Grosse T - - 2003
Cellular element concentrations and dry weight contents in A6 cells were determined using electron microprobe analysis to establish whether these cells exhibit a regulatory volume increase (post-RVD-RVI) when re-establishing isotonicity following a hypotonically induced regulatory volume decrease (RVD). Hypotonic stress was induced by reducing basolateral [NaCl], and hence, osmolarity fell ...
Chen Jinglong - - 2003
The TRPC1 (transient receptor potential canonical 1) protein, which is thought to encode a non-selective cation channel activated by store depletion and/or an intracellular messenger, is expressed in a number of non-excitable cells. However, the physiological functions of TRPC1 are not well understood. The aim of these studies was to ...
Barriere Herve - - 2003
Several papers reported the role of TASK2 channels in cell volume regulation and regulatory volume decrease (RVD). To check the possibility that the TASK2 channel modulates the RVD process in kidney, we performed primary cultures of proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) from wild-type and TASK2 knockout ...
Jin Nan Ge - - 2003
Volume regulation is essential for cell function, but it is unknown which channels are involved in a regulatory volume decrease (RVD) in human gastric epithelial cells. Exposure to a hypotonic solution caused the increase in AGS cell volume, followed by the activation of a current. The reversal potential of the ...
Gao S - - 2003
A field study on the removal of Se from agricultural subsurface drainage was conducted from May 1997 to February 2001 in the Tulare Lake Drainage District (TLDD) of San Joaquin Valley, California. A flow-through wetland system was constructed consisting of ten 15- x 76-m unlined cells that were continuously flooded ...
Tony Markel,Matthew Zolot,Keith B. ...
This paper summarizes a methodology for determining desirable characteristics and requirements of the energy storage system for fuel cell hybrid vehicles. The purpose of this work was to provide supporting analysis for the FreedomCAR Technical Teams in defining energy storage requirements for fuel cell vehicles. The power and energy requirements ...
Laquerriere Patrice - - 2003
Numerous studies have described the bioactive properties of glass particles in the SiO(2)-CaO-Na(2)O-P(2)O(5) system. This kind of material is capable of developing a direct contact with bone through dissolution and physicochemical reactions. We have investigated the influence of bioactive particles, and ionic products from the same particles, on the intracellular ...
Martin Karin - - 2003
The high speed production of fluid segments for the highly parallelized cultivation of monoclonal cell populations was carried out by the use of microchip segmentor modules. Aqueous fluid segments, embedded in a non-miscible carrier liquid, were produced with frequencies up to 30 s(-1) and showed a high homogeneity in size. ...
Maier, Roland
The iteration of random tessellations in R<sup>d</sup> is considered, where each cell of an initial tessellation is further subdivided into smaller cells by so-called component tessellations. Sufficient conditions for stationarity and isotropy of iterated tessellations are given. Formulae are derived for the intensities of their facet processes, and for the ...
Auberson Muriel - - 2003
Liddle's syndrome is a monogenic form of hypertension caused by mutations in the PY motif of the COOH terminus of beta- and gamma-epithelial Na+ channel (ENaC) subunits. These mutations lead to retention of active channels at the cell surface. Because of the critical role of this PY motif in the ...
Kim Youn-Bae - - 2003
Ion transporters such as Na(+)/H(+) exchanger (NHE), Cl(-)/HCO(3)(-) exchanger (AE), and Na(+)/HCO(3)(-) cotransporter (NBC) are known to contribute to the intracellular pH (pH(i)) regulation during agonist-induced stimulation. This study examined the mechanisms for the pH(i) regulation in the mouse parotid and sublingual acinar cells using the fluorescent pH-sensitive probe, BCECF. ...
Fleischhauer J C - - 2003
A(1) adenosine receptors (ARs) reduce, and A(2)ARs increase intraocular pressure, partly by differentially altering resistance to aqueous humor outflow. It is unknown whether the opposing effects of A(1)AR and A(2)AR agonists are mediated at different outflow-pathway cell targets or by opposing actions on a single cell target. We tested whether ...
Ho Steffan N - - 2003
NFAT5/TonEBP, the most recently described member of the rel/NFkappaB/NFAT family of signal-dependent transcription factors, is activated by extracellular hypertonicity-a cellular stress of particular and perhaps unique physiologic relevance to cells of the renal medulla. Accumulating evidence suggests that NFAT5/TonEBP also functions in vivo under isotonic conditions as part of a ...
Chung Ji-Hyun - - 2003
There has been no previous indication that vacuolar ATPases (V-ATPases) require sphingolipids for function. Here we show, by using Saccharomyces cerevisiae sur4Delta and fen1Delta cells, that sphingolipids with a C26 acyl group are required for generating V1 domains with ATPase activity. Sphingolipids in sur4Delta cells contain C22 and C24 acyl ...
Gervais Patrick - - 2003
The effect of a rapid temperature increase on the volume of different types of cells was investigated. Experiments were carried out using continuous microscopic image analysis. Volume variation of yeast cells, yeast spheroplasts and human leukaemia cells was measured during the transient phase after a thermal shift. The thermal shift ...
Zilli L - - 2003
The goal of the present study was to evaluate the changes in the cell type composition and ATPase activities (total ATPase, ouabain-sensitive Na+/K(+)-ATPase, furosemide-sensitive Na(+)-ATPase) that occur during the different stages of the moulting cycle in the hepatopancreas of the Marsupenaeus japonicus. The results clearly suggest that the number of ...
Grunnet Morten - - 2003
Many important physiological processes involve changes in cell volume, e.g. the transport of salt and water in epithelial cells and the contraction of cardiomyocytes. In this study, we show that voltage-gated KCNQ1 channels, which are strongly expressed in epithelial cells or cardiomyocytes, and KCNQ4 channels, expressed in hair cells and ...
Abdullaev Iskandar F - - 2003
Whole-cell recordings showed that, in mouse mammary C127 cells transfected with the full genome of the bovine papilloma virus (BPV), a hypotonic challenge induced the activation of outwardly rectifying Cl- currents with a peak amplitude 2.7 times greater than that in control C127 cells. Cell-attached single-channel recordings showed that BPV-induced ...
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