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Results 251 - 300 of 1934
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Stock Christian - - 2007
Extracellular pH and the Na(+)/H(+) exchanger (NHE1) modulate tumor cell migration. Yet, the pH nanoenvironment at the outer surface of the cell membrane (pH(em)) where cell/matrix interaction occurs and matrix metalloproteinases work was never measured. We present a method to measure this pH nanoenvironment using proton-sensitive dyes to label the ...
Nguyen Anh-Nguyet T - - 2007
In autosomal dominant polycystic kidney disease (ADPKD), cyst formation and enlargement require proliferation of mural renal epithelial cells and the transepithelial secretion of fluid into the cyst cavity. Na,K-ATPase is essential for solute and water transport in ADPKD cells, and ouabain blocks fluid secretion in these cells. By binding to ...
Takayanagi Takatoshi - - 2007
Both coccolith-bearing cells (C-cells) and naked cells (N-cells) of the coccolithophorid Pleurochrysis haptonemofera can grow in salinities of more than 7 per thousand (about 20% of a "normal" sea water salinity [35 per thousand]), with the highest growth rates in salinities of more than 14 per thousand. Microscopic observations of ...
Renaudo Adrien - - 2007
The sigma-1 receptor is an intracellular protein characterized as a tumor biomarker whose function remains mysterious. We demonstrate herein for the first time that highly selective sigma ligands inhibit volume-regulated chloride channels (VRCC) in small cell lung cancer and T-leukemia cells. Sigma ligands and VRCC blockers provoked a cell cycle ...
Bachmann Oliver - - 2007
We have previously shown that stimulation of acid secretion in parietal cells causes rapid initial cell shrinkage, followed by Na(+)/H(+) exchange-mediated regulatory volume increase (RVI). The factors leading to the initial cell shrinkage are unknown. We therefore monitored volume changes in cultured rabbit parietal cells by confocal measurement of the ...
Maeno Emi - - 2006
Sustained cell shrinkage is a major hallmark of apoptotic cell death. In apoptotic cells, whole cell volume reduction, called apoptotic volume decrease (AVD), proceeds until fragmentation of cells. Under non-apoptotic conditions, human epithelial HeLa cells exhibited a slow regulatory volume increase (RVI) after osmotic shrinkage induced by exposure to hypertonic ...
Karl Mike O - - 2007
Activation of A1 and A2A subtype adenosine receptors (AR) likely exert opposing effects on outflow of aqueous humor, and thereby, on intraocular pressure. Selective agonists of adenosine receptor (AR) subtypes have previously been applied to trabecular meshwork (TM) and Schlemm's canal (SC) cells to identify the site(s) of differential purinergic ...
Iordache Claudiu - - 2007
Butyrate and other short-chain fatty acids (SCFA), produced by colonic bacterial flora, affect numerous epithelial cell functions. To better understand how SCFA regulate ion transport, we investigated the effects of 4-phenylbutyrate (4-PBA) on Na(+) absorption in T84 cells. Under standard cell culture conditions, the short circuit current did not display ...
Arystarkhova Elena - - 2007
Functional properties of Na-K-ATPase can be modified by association with FXYD proteins, expressed in a tissue-specific manner. Here we show that expression of FXYDs in cell lines does not necessarily parallel the expression pattern of FXYDs in the tissue(s) from which the cells originate. While being expressed only in lacis ...
Díaz-Elizondo Jessica - - 2006
Cells have developed compensatory mechanisms to restore cell volume, and the ability to resist osmotic swelling or shrinkage parallels their resistance to necrosis or apoptosis. There are several mechanisms by which cells adapt to hyposmotic stress including that of regulatory volume decrease. In ischemia and reperfusion, cardiomyocytes are exposed to ...
Hansen Ann-Kristin - - 2007
The amount of aquaporins present and the cellular ability to perform regulatory volume changes are likely to be important for fluid secretions from exocrine glands. In this work these phenomena were studied in an SV40 immortalized rat submandibular acinar cell line. The regulatory cell volume characteristics have not previously been ...
Mey Kristianna H - - 2006
OBJECTIVES: The objectives of this study were to examine the effect of acute otitis media on the bony development of the growing middle ear air cell system with a reliable and concise stereologic histomorphometric method and to generate a standard baseline growth plot for the middle ear of the rat. ...
Zhang Hai-tao - - 2006
AIM: To investigate the role of intercellular potassium in tachyplesin-induced HL-60 cells apoptosis. METHODS: The concentration of intercellular potassium, cell volume and mitochondrial membrane potential were examined by flow cytometry. RESULTS: The concentration of intercellular potassium reduced in a time-dependent manner in tachyplesin-treated HL-60 cells. In addition, the loss of ...
Tata Despina A - - 2006
Individuals with clinical disorders associated with elevated plasma glucocorticoids, such as major depressive disorder and Cushing's syndrome, are reported to have smaller hippocampal volume. To understand how the hippocampus responds at the cellular and subcellular levels to glucocorticoids and how such changes are related to volume measures, we have undertaken ...
Nukui Miho - - 2006
Apoptosis is a major form of cell death that occurs in response to a variety of signals in both physiological and pathological situations. A hallmark of apoptosis is normotonic cell shrinkage, called apoptotic volume decrease (AVD), the process of which involves fluxes of K(+), Cl(-), and Na(+). Na(+) influx was ...
Harrison, P. J.
Three marine diatoms, Skeletonema costatum, Chaetoceros debilis , and Thalassiosira gravida were grown under no limitation and ammonium or silicate limitation or starvation. Changes in cell morphology were documented with photomicrographs of ammonium and silicate-limited and non-limited cells, and correlated with observed changes in chemical composition. Cultures grown under silicate ...
Sicko-Goad, Linda
Cell volume calculations are often used to estimate biomass of natural phytoplankton assemblages. Such estimates may be questioned due to morphological differences in the organisms present. Morphometric analysis of 8 species representative of phytoplankton types found in the Great Lakes shows significant differences in cell constituent volumes. Volume of physiologically ...
Lei Jianxun - - 2007
Late in gestation, the developing air space epithelium switches from chloride and fluid secretion to sodium and fluid absorption. Absorption requires Na-K-ATPase acting in combination with apical sodium entry mechanisms. Hypothyroidism inhibits perinatal fluid resorption, and thyroid hormone [triiodothyronine (T3)] stimulates adult alveolar epithelial cell (AEC) Na-K-ATPase. This study explored ...
McDonald S A - - 2006
X-ray microtomography has been employed to collect three-dimensional images of aluminium closed-cell foam, enabling the internal structure to be characterized in three dimensions. An experimental technique and image analysis approach has been developed, and is described, in terms of the labelling of cells and the extraction of quantitative data such ...
Milius Marit - - 2006
The responses of antennal taste sensilla of the ground beetle Pterostichus aethiops to 100mM Na(+)-salts and their mixtures with 1 and 10mM NaOH were compared. An increase in pH by 0.3-0.6 units in 100mM Na(+)-salt solutions, caused by the content of 1mM NaOH, was too small, except for alkaline Na(2)HPO(4), ...
Komlosi P - - 2006
At the macula densa, flow-dependent changes in luminal composition lead to tubuloglomerular feedback and renin release. Apical entry of sodium chloride in both macula densa and cortical thick ascending limb (cTAL) cells occurs via furosemide-sensitive sodium-chloride-potassium cotransport. In macula densa, apical entry of sodium chloride leads to changes in cell ...
Comes Núria - - 2006
In the eye, trabecular meshwork (TM) cell volume may be an important determinant of aqueous humor outflow. Among their functions, ClC-2 chloride channels are thought to be involved in regulation of cellular volume and intracellular [Cl(-)]. We characterized the properties and modulation of an inwardly rectifying chloride current activated in ...
Yang Qiongqiong - - 2006
Point mutations in the B1 subunit of vacuolar H+ -ATPase are associated with impaired ability of the distal nephron to secrete acid (distal renal tubular acidosis). For testing of the hypothesis that these mutations interfere with assembly and trafficking of the H+ -ATPase, constructs that mimic seven known point mutations ...
Guttridge M G - - 2006
The COBE Spectra is used to volume/red blood cell (RBC) deplete BM before transplantation or cryopreservation. We have audited our results to identify the effect of transit time, refrigerated storage, age and cellular composition on mononuclear cells (MNC) and CD34+ cell recoveries, volume/RBC depletion and neutrophil engraftment. In total, 88 ...
Hayashi Yasuo - - 2006
PURPOSE: It has been known that the thermosensitivity of tumour cells can be increased by lowering intra-cellular pH (pHi) by inhibiting pHi control mechanisms. The pHi is partially controlled by transport of H+ from cytoplasm into endocytic and secretary systems in the cells mediated by vacuolar type H+ATPase and also ...
Jung Jaehoon - - 2006
Cofilin is essential for actin filament remodeling in various cell types. We previously reported that ouabain leads to dephosphorylation of cofilin, resulting in cytoskeletal reorganization and cell volume change. We report here that the extracellular [K(+)](e) deprivation causes dephosphorylation of cofilin with disruption of cytoskeletal structures and cell shrinkage. These ...
Guan Yong-Yuan - - 2006
The volume-regulated Cl(-) current (I(Cl.vol)) is responsible for the transmembrane Cl(-) transport that is involved in cell volume regulatory mechanisms. Although the regulation of cell volume is a fundamental function of healthy cells for maintaining constant size, the molecular genetic identification of I(Cl.vol) is still being debated. Recent studies in ...
Stutzin A - - 2006
Cell volume regulation is one of the most fundamental homeostatic mechanisms and essential for normal cellular function. At the same time, however, many physiological mechanisms are associated with regulatory changes in cell size meaning that the set point for cell volume regulation is under physiological control. Thus, cell volume is ...
Maeno E - - 2006
AIM: Sustained cell shrinkage is associated with apoptosis. Apoptotic volume decrease, which is known to be induced by release of osmolytes including Cl- ions, may be an essential event for apoptosis induction. Provided any anion channels and/or anion transporters are basally functioning, there is a possibility that imposition of a ...
Roger Anderson O - - 2006
A novel method of estimating the cell volume of non-testate, free-living amoebae is presented. Measurements of the length (L) of motile forms of some amoebae, obtained by applying some basic rules, can be used to calculate diameter (D) using a relatively simple formula, derived from regression analysis (N=39): D=0.6L. Important ...
Kuang Kunyan - - 2006
Most cells possess mechanisms that are able to detect cellular volume shifts and to signal the initiation of appropriate volume regulatory responses. However, the identity and characteristics of the detecting mechanism remain obscure. In this study, we explored the influence of hypertonic and hypotonic challenges of varying magnitude on the ...
Lim C H - - 2006
AIM: The role of high cholesterol-containing microdomains in the signal transduction cascade leading to the activation of volume-regulated anion channels (VRACs) was studied. METHODS: Osmotic cell swelling-induced efflux of 125I- was determined in human epithelial Intestine 407 cells and in skin fibroblasts obtained from healthy controls or Niemann-Pick type C ...
Orlov S N - - 2006
Na/K-ATPase is the only known target of cardiotonic steroids (CTS) identified in plants, amphibians and later on in several mammalian species, including human. We focus our review on recent data implicating CTS in the tissue-specific regulation of cell survival and death. In vascular smooth muscle cells, CTS inhibited cell death ...
Stubbe Jane - - 2006
In the rat, urinary concentrating ability develops progressively during the third postnatal (P) week and nearly reaches adult level at weaning (P21) governed by a rise in circulating glucocorticoid. Elevated extracellular osmolality can lead to growth arrest of epithelial cells. We tested the hypothesis that supranormal exposure of rat pups ...
Trevisi Lucia - - 2006
3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) uptake and reduction is widely used to evaluate cell proliferation and viability. MTT is taken up by the cells through endocytosis. We find that ouabain (1-200 nM) inhibits MTT reduction in human umbilical vein endothelial cells (HUVEC) without affecting cell viability. Ouabain does not inhibit MTT reduction ...
Woclawek-Potocka Izabela - - 2006
Corpus luteum (CL) is a reproductive gland that plays a crucial endocrine role in the regulation of the estrous cycle, fertility, and pregnancy in cattle. The main function of CL is secretion of progesterone (P4), an important hormone for establishment a successful pregnancy, whereas prostaglandin F(2alpha) (PGF(2alpha)), 17beta-estradiol (E(2)) and ...
Pedersen Stine Falsig - - 2006
The ubiquitous plasma membrane Na+/H+ exchanger NHE1 is highly conserved across vertebrate species and is extensively characterized as a major membrane transport mechanism in the regulation of cellular pH and volume. In recent years, the understanding of the role of NHE1 in regulating cell function has expanded from one of ...
Lovett D L - - 2006
In euryhaline crabs, ion-transporting cells are clustered into osmoregulatory patches on the lamellae of the posterior gills. To examine changes in the branchial osmoregulatory patch in the blue crab Callinectes sapidus in response to change in salinity and to correlate these changes with other osmoregulatory responses, crabs were acclimated to ...
Liu Xibao - - 2006
Regulation of cell volume in response to changes in osmolarity is critical for cell function and survival. However, the molecular basis of osmosensation and regulation of cell volume are not clearly understood. We have examined the mechanism of regulatory volume decrease (RVD) in salivary gland cells and report a novel ...
Silva E - - 2006
The present study evaluated the hypothesis of whether increases in vectorial Na+ transport translate into facilitation of Na+-dependent L-DOPA uptake in cultured renal epithelial tubular cells. Increases in vectorial Na+ transport were obtained in opossum kidney (OK) cells engineered to overexpress Na+-K+-ATPase after transfection of wild type OK cells with ...
Zhang H-N - - 2006
Cell volume can be altered by two different ways, swelling and shrinkage. Cell swelling is regulated by volume-regulated Cl- channel (VRC). It is not well understood whether shrinkage is regulated by VRC. We previously found that antisense oligonucleotide specific to ClC-3 (ClC-3 antisense) prevented cell proliferation, which was related to ...
Choi Jae Young - - 2006
The proper homeostasis of the liquid lining the surface of the middle ear cavity is vitally important for maintaining a fluid-free middle ear cavity. Disruption of this homeostasis leads to fluid collection in the middle ear cavity and results in otitis media with effusion. We demonstrated the molecular and functional ...
Lifchitz, Alain
The crystallographer's main problem (i.e. the phasing of Fourier transform moduli) leads to the study of n-sphere periodic close packing. The geometric properties of this arrangement allow one to determine by recurrence reasoning the matrix of the general expressions for the coordinates of the points that define the cell. It ...
Canetta Elisabetta - - 2006
The detrimental effects of ethanol toxicity on the cell surface morphology of Saccharomyces cerevisiae (strain NCYC 1681) and Schizosaccharomyces pombe (strain DVPB 1354) were investigated using an atomic force microscope (AFM). In combination with culture viability and mean cell volume measurements AFM studies allowed us to relate the cell surface ...
Strange Kevin - - 2006
Ste20 serine/threonine kinases regulate fundamental cellular processes including the cell cycle, apoptosis, and stress responses. Recent studies in Caenorhabditis elegans and mammals demonstrate that Ste20 kinases also function in cell volume sensing and Cl- transport regulation. Yeast Ste20 initiates a shrinkage activated MAPK cascade that regulates organic osmolyte accumulation. Ste20 ...
Hornbaek Tina - - 2006
In situ analyses of single Listeria monocytogenes cells at subinhibitory concentrations of leucocin 4010 and nisin revealed two subpopulations when measured by fluorescence ratio imaging microscopy (FRIM) after staining with 5(6)-carboxyfluorescein diacetate succinimidyl ester. One subpopulation consisted of cells with a dissipated pH gradient (DeltapH), and the other consisted of ...
McFerrin Michael B - - 2006
Many cells, including neuronal and glial progenitor cells, stem cells and microglial cells, have the capacity to move through the extracellular spaces of the developing and mature brain. This is particularly pronounced in astrocyte-derived tumors, gliomas, which diffusely infiltrate the normal brain. Although a significant body of literature exists regarding ...
Carlin Ryan W - - 2006
Epithelial ion transport disorders, including cystic fibrosis, adversely affect male reproductive function by nonobstructive mechanisms and by obstruction of the distal duct. Continuous cell lines that could be used to define ion transport mechanisms in this tissue are not readily available. In the present study, porcine vas deferens epithelial cells ...
Irschick Eveline U - - 2006
Retinal pigment epithelial (RPE) cells provide crucial functions for the maintenance of the retinal environment. We investigated the phagocytotic mechanisms of RPE cells evaluating the question whether particle uptake underlies a diurnal rhythm. Additionally, a possible connection of volume regulation and the phagocytotic function of RPE cells was studied. As ...
Zadrag Renata - - 2006
Reaching the limit of cell divisions, a phenomenon referred to as replicative aging, of the yeast Saccharomyces cerevisiae involves a progressive increase in the cell volume. However, the exact relationship between the number of cell divisions accomplished (replicative age), the potential for further divisions and yeast cell volume has not ...
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