Search Results
Results 451 - 500 of 1933
< 5 6 7 8 9 10 11 12 13 14 15 >
Boughanmi N - - 2003
Medicago sativa var. Gabes is a perennial glycophyte that develops new shoots even in high salinity (150 mM NaCl). In the upper exporting leaves, K(+) is high and Na(+) is low by comparison with the lower leaves, where Na(+) accumulation induces chlorosis after 4 weeks of NaCl treatment. By secondary ...
Pchejetski Dimitri - - 2003
Treatment with ouabain led to massive death of principal cells from collecting ducts (C7-MDCK), indicated by cell swelling, loss of mitochondrial function, an irregular pattern of DNA degradation, and insensitivity to pan-caspase inhibitor. Equimolar substitution of extracellular Na(+) by K(+) or choline(+) sharply attenuated the effect of ouabain on intracellular ...
Nabekura Takashi - - 2003
Hypotonic challenge induces transient swelling in glial cells, which is typically followed by a regulatory volume decrease (RVD). In contrast, lactic acidosis (lactacidosis) induces persistent cell swelling in astrocytes without an accompanying RVD. In the present study, we studied the mechanisms by which lactacidosis interferes with normal volume regulation in ...
Espelt M V - - 2003
The relationship between cell volume and K(+) transmembrane fluxes of goldfish (Carassius auratus) hepatocytes exposed to anisotonic conditions or energetic limitation was studied and compared with the response of hepatocytes from trout (Oncorhynchus mykiss) and rat (Rattus rattus). Cell volume was studied by video- and fluorescence microscopy, while K(+) fluxes ...
Magnuson Bengt - - 2003
This article presents a new approach to understanding the physiological functions of the mastoid cell system. It is suggested that the cell system, in combination with the continuous blood flow through the adjacent large vessels, makes up a compound functional unit that serves to protect the sensitive vestibular part of ...
Reid Scott D - - 2003
Percoll density-gradient separation, combined with peanut lectin agglutinin (PNA) binding and magnetic bead separation, was used to separate dispersed fish gill cells into sub-populations. Functional characterization of each of the sub-populations was performed to determine which displayed acid-activated phenamil- and bafilomycin-sensitive Na(+) uptake. Analysis of the mechanism(s) of (22)Na(+) influx ...
Diaz Roberto J - - 2003
Accumulation of osmotically active metabolites, which create an osmotic gradient estimated at ~60 mOsM, and cell swelling are prominent features of ischemic myocardial cell death. This study tests the hypothesis that reduction of ischemic swelling by enhanced cell volume regulation is a key mechanism in the delay of ischemic myocardial ...
Ikeuchi Tomohiko - - 2003
Salt tolerance was induced in Bacillus subtilis IFO 3025 cells when a moderate osmotic stress was imposed by incubation in the presence of compatible solutes and 0.5 M NaCl or 0.8 M sorbitol. The optimum condition for inducing salt tolerance was observed when the cells were incubated in a solution ...
Biswas Sondip Kumar - - 2003
The morphologies, numbers, sizes and volumes of all organelles and cell components identified on ultrathin sections of aerobically grown exponential phase yeast cells of Exophiala dermatitidis in G1 phase were examined by freeze-substitution fixation and serial ultrathin sectioning. The cell wall consisted of three layers and occupied approximately 22% of ...
Wehner F - - 2003
In recent years, it has become evident that the volume of a given cell is an important factor not only in defining its intracellular osmolality and its shape, but also in defining other cellular functions, such as transepithelial transport, cell migration, cell growth, cell death, and the regulation of intracellular ...
Mori Shin-ichiro - - 2002
Acidosis coupled to lactate accumulation, called lactacidosis, occurs in cerebral ischemia or trauma and is known to cause persistent swelling in neuronal and glial cells. It is therefore possible that mechanisms of cell volume regulation are impaired during lactacidosis. Here we tested this possibility using neuronally differentiated NG108-15 cells. These ...
Liu Jiang - - 2002
BACKGROUND: The decreases in proximal tubule sodium reabsorption seen with chronic renal failure and volume expansion have been ascribed to circulating digitalis-like substances (DLS). However, the circulating concentrations of DLS do not acutely inhibit the sodium pump to a degree consistent with the observed changes in proximal tubule sodium reabsorption. ...
Arreola Jorge - - 2002
Salivary gland acinar cells shrink when Cl(-) currents are activated following cell swelling induced by exposure to a hypotonic solution or in response to calcium-mobilizing agonists. The molecular identity of the Cl(-) channel(s) in salivary cells involved in these processes is unknown, although ClC-3 has been implicated in several tissues ...
Liu Ruisheng - - 2002
The luminal NaCl concentration ([NaCl]) at the macula densa (MD) controls both tubuloglomerular feedback (TGF) and renin release. Nitric oxide (NO) inhibits TGF sensitivity to a great extent. The NO concentration in the MD cells is not known. This study measured this concentration in MD cells with confocal microscopy in ...
Abdulla Fuad A - - 2002
Section of rat sciatic nerve (axotomy) increases the excitability of neurons in the L(4)-L(5) dorsal root ganglia (DRG). These changes are more pronounced in animals that exhibit a self-mutilatory behavior known as autotomy. We used whole cell recording to examine changes in the tetrodotoxin-sensitive (TTX-S) and the tetrodotoxin-resistant (TTX-R) components ...
Pritchard Scott - - 2002
Loading of the spine alters the osmotic environment in the intervertebral disk (IVD) as interstitial water is expressed from the tissue. Cells from the three zones of the IVD, the anulus fibrosus (AF), transition zone (TZ), and nucleus pulposus (NP), respond to osmotic stress with altered biosynthesis through a pathway ...
Pommer Angela C - - 2002
Cryopreservation requires exposure of sperm to extreme variations in temperature and osmolality. The goal of this experiment was to determine the osmotic tolerance levels of equine sperm by analyzing motility, viability, mitochondrial membrane potential (MMP), and mean cell volume (MCV). Spermatozoa were incubated at 22 degrees C for 10 min ...
Wang Liwei - - 2002
Nasopharyngeal carcinoma cells, CNE-2Z, when swollen by 47% hypotonic solution, exhibited a regulatory volume decrease (RVD). The RVD was inhibited by extracellular applications of the chloride channel blockers tamoxifen (30 microM; 61% inhibition), 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, 100 microM; 60% inhibition), and ATP (10 mM; 91% inhibition). The level and time ...
Orlando Geraldine S - - 2002
In vivo human esophageal epithelial cells are regularly exposed to hyposmolal stress. This stress, however, only becomes destructive when the surface epithelial cell (barrier) layers are breached and there is contact of the hyposmolal solution with the basolateral cell membranes. The present investigation was designed to examine the effects of ...
Chen Lixin - - 2002
Patch-clamping and cell image analysis techniques were used to study the expression of the volume-activated Cl(-) current, I(Cl(vol)), and regulatory volume decrease (RVD) capacity in the cell cycle in nasopharyngeal carcinoma cells (CNE-2Z). Hypotonic challenge caused CNE-2Z cells to swell and activated a Cl(-) current with a linear conductance, negligible ...
Yasukawa Tomoyuki - - 2002
A picoliter-volume electrochemical analytical chamber has been developed for detecting the metabolic flux resulting from the stress responses of a single plant cell. Electrochemical cells, with volumes as small as 100 pL, were fabricated by controlled electrochemical dissolution of a gold wire sealed in glass (the back-etching of the metal ...
Thurston-Stanfield Cindy L - - 2002
ON and OFF cells of the rostral ventromedial medulla are hypothesized to modulate nociception with ON cells facilitating pain and OFF cells inhibiting pain. The current study analyzed the effects of intraperitoneal saline at different volumes and temperatures on nociception (tail flick reflex), blood pressure, and the activity of ON ...
Tararthuch A L - - 2002
In several tissues ammonium ions are able to use the transport pathways of other ions, particularly of K+. We investigated this possibility in the C11 clone of MDCK cells, thought to represent intercalated cells, in control and 0 Cl- conditions. Cell pH was measured by ratiometric fluorescence microscopy using the ...
Kern G - - 2002
Cell suspensions of rainbow trout Oncorhynchus mykiss pseudobranch, prepared by Ca(2+) depletion and mechanical maceration, contained a distinct population of cells that always kept their relatively cuboidal shape and did not round up in suspension or proliferate after adhering to the surface of cell culture dishes. Phasecontrast microscopy revealed an ...
Zonia Laura - - 2002
Oscillatory growth of pollen tubes has been correlated with oscillatory influxes of the cations Ca(2+), H(+), and K(+). Using an ion-specific vibrating probe, a new circuit was identified that involves oscillatory efflux of the anion Cl(-) at the apex and steady influx along the tube starting at 12 microm distal ...
Baev Didi - - 2002
Human salivary histatin 5 (Hst 5) is a nonimmune salivary protein with antifungal activity against an important human pathogen, Candida albicans. The candidacidal activity of histatins appears to be a distinctive multistep mechanism involving depletion of the C. albicans intracellular ATP content as a result of nonlytic ATP efflux. Hst ...
Hermoso Marcela - - 2002
Volume-sensitive osmolyte and anion channels (VSOACs) are activated upon cell swelling in most vertebrate cells. Native VSOACs are believed to be a major pathway for regulatory volume decrease (RVD) through efflux of chloride and organic osmolytes. ClC-3 has been proposed to encode native VSOACs in Xenopus laevis oocytes and in ...
Behnam-Motlagh Parviz - - 2002
PURPOSE: Highly 5-HT(3)-receptor-specific antiemetic agents may have different effects on ion transport of tumour cells during treatment with cytotoxic drugs. Cell volume regulation, which is dependent on potassium ion (K(+)) flux, is involved the control of cell growth, proliferation, and apoptosis. K(+)-flux response mechanisms to the antiemetics ondansetron and granisetron ...
Smets Ilse - - 2002
In renal ischemia, tubular obstruction induced by swelling of epithelial cells might be an important mechanism for reduction of the glomerular filtration rate. We investigated ischemic cell swelling by examining volume regulation of A6 cells during metabolic inhibition (MI) induced by cyanide and 2-deoxyglucose. Changes in cell volume were monitored ...
Vitko Yulia V - - 2002
The effects of intracellular application of trypsin on the Cl- current induced by hypotonic cell swelling (I(Cl,swell)) in human prostate cancer epithelial cells (LNCaP) was studied using the patch-clamp technique. In cells predialyzed with 1 mg/mL trypsin, I(Cl,swell)) developed and diminished in response to the application and withdrawal of hypotonic ...
Ogasawara K - - 2002
Previously, we have found that immunosuppressive macrophages (M(phi)s) induced by Mycobacterium intracellulare-infection (MI-M(phi)s) required cell contact with target T cells to express their suppressor activity against concanavalin A (Con A)-induced T cell mitogenesis. In this study, we examined the profiles of cell-to-cell interaction of MI-M(phi)s with target T cells. First, ...
Kraegeloh Annette - - 2002
The role of K(+) in osmoregulation of the halophilic bacterium Halomonas elongata was investigated. At lower salinities (0.51 M NaCl), K(+) was the predominant cytoplasmic solute (1.25 micro mol mg protein(-1)). At higher salinities (1.03 M NaCl) ectoine became the main cytoplasmic solute (1.57 micro mol mg protein(-1)), while the ...
Luo C - - 2002
It was reported previously that haemadsorption by the haemagglutinin (HA) protein of influenza B virus required that the protein must undergo desialidation. When MDCK and COS cells were infected with influenza B/Kanagawa/73 virus in the presence of a neuraminidase (NA) inhibitor, Zanamivir, haemadsorption on MDCK cells was inhibited but that ...
Luo Dawei - - 2002
A modified analytical and experimental method using differential scanning calorimeter (DSC) was developed to determine the cell volume change during the freezing process. Two cell types were used in the study: human platelets and erythrocytes (red blood cells). Isotonic cell suspensions with different cytocrits were prepared and used in the ...
Gomes Pedro - - 2002
The present study describes characteristic features of two clonal subpopulations of opossum kidney (OK) cells (OK(LC) and OK(HC)) that are functionally different but morphologically identical. The most impressive differences between OK(HC) and OK(LC) cells are the overexpression of Na+-K+-ATPase and type 3 Na+/H+ exchanger by the former, accompanied by an ...
Sakamoto T - - 2002
Euryhaline teleosts rapidly regulate their ion flux at the chloride cells on entry to different salinities. The external trigger(s) for the rapid opening and closing of the chloride cell apical surface, the site of salt secretion, were examined in the skin of the mudskipper. With DASPEI (a mitochondrial probe) and ...
Vrede Katarina - - 2002
Marine bacterioplankton were isolated and grown in batch cultures until their growth became limited by organic carbon (C), nitrogen (N), or phosphorus (P). Samples were taken from the cultures at both the exponential and stationary phases. The elemental composition of individual bacterial cells was analyzed by X-ray microanalysis with an ...
Franco Jaime M - - 2002
The origin of T cells after highly active antiretroviral therapy (HAART) in patients infected with human immunodeficiency virus 1 (HIV-1) is now under discussion. The possibility of renewed lymphopoiesis in aged thymuses is still controversial. In this work we combine the analysis of naïve T cells, T-cell receptor excision circles ...
Morbach Susanne - - 2002
Fluctuation of external osmolarity is one of the most common types of environmental stress factors for all kind of cells, both of prokaryotic and of eukaryotic origin. Cells try to keep their volume and/or turgor pressure constant; consequently, both a decrease (hypoosmotic stress) and an increase (hyperosmotic stress) of the ...
Li Hongshan - - 2002
The pharmacokinetics and cell trafficking dynamics of 2-amino-2-[2-(4-octylphenyl)ethyl]propane-1,3-diol hydrochloride (FTY720), a novel immunosuppressive agent, were examined in cynomolgus monkeys (three males and three females). After single doses of 0.1 mg/kg p.o. or i.v. bolus and 1 mg/kg p.o. were administered to the animals, the concentrations of FTY720, and the numbers ...
Bourillot P-Y - - 2002
In vertebrate development, most signalling factors behave as morphogens, eliciting divergent cell fates according to their concentration. We ask how cells interpret morphogen concentration as it changes during the establishment of a gradient. Using dissociated blastula cells of Xenopus exposed to activin for only 10 minutes, we have followed the ...
Fricke Wieland - - 2002
Biophysical parameters potentially involved in growth regulation were studied at the single-cell level in the third leaf of barley (Hordeum vulgare) after exposure to various degrees of NaCl stress for 3 to 5 d. Gradients of elongation growth were measured, and turgor pressure, osmolality, and water potentials (psi) were determined ...
Matthews Jeffrey B - - 2002
Defective regulation of epithelial secretion underlies the clinical manifestations of a number of important human diseases ranging from cystic fibrosis to secretory diarrhea. Although much attention has focused on the role of apical membrane chloride (Cl-) channels in this process, emerging evidence highlights the importance of a basolateral Na+-K+-2Cl- cotransporter ...
Camisard V - - 2002
A new in situ microscope (ISM) was developed and tested to perform in-line monitoring of average cell volume and cell concentration in agitated cultures subjected to osmotic stress. The ISM is directly immersed into the agitated broth in a bioreactor and generates still images of cells by using pulsed luminescent ...
Roomans G M - - 2002
X-ray microanalysis is commonly applied in biomaterials research to study changes in biomaterial composition, calcifications, or to identify particulates in tissue that has been in contact with biomaterials. Studies where the effect of biomaterials on the naturally occurring elements in the cells are studied are rare. Exposure to or contact ...
Fürst J - - 2002
The ability of cells to readjust their volume after swelling, a phenomenon known as regulatory volume decrease (RVD), is a fundamental biological achievement guaranteeing survival and function of cells under osmotic stress. This article reviews the mechanisms of RVD in mammalian cells with special emphasis on the activation of ion ...
Shiono Noritsugu - - 2002
Protective effects of L-arginine were evaluated in a human ventricular heart cell model of low-volume anoxia and reoxygenation independent of alternate cell types. Cell cultures were subjected to 90 min of low-volume anoxia and 30 min of reoxygenation. L-Arginine (0-5.0 mM) was administered during the preanoxic period or the reoxygenation ...
Han Kap-Hoon - - 2002
Free-living cells monitor extracellular 'osmotic strength' and respond metabolically to offset unfavourable osmotic intracellular solute concentrations. Here, we report the reconstruction of the Aspergillus nidulans salt stress-controlling MAP kinase pathway, based on homology analysis with known yeast genes. In A. nidulans, salt stress HOG genes, such as pbsA, hogA, ptpA ...
Cai Xinxia - - 2002
The fabrication of microelectrodes integrated within ultra-low-volume microtiter chambers for the amperometric determination of metabolites continues to be of interest in the subject of single-cell and high-throughput screening. The microsystem described in this paper consists of a two-microelectrode sensor with a microfluidic dispensation technology, which is able to deliver both ...
Porcelli Anna Maria - - 2002
The molecular mechanisms responsible for intracellular pH regulation in the U2-OS osteosarcoma cell line were investigated by loading with 2',7'-bis(2-carboxyethyl)-5(6) carboxyfluorescein ester and manipulation of Cl(-) and Na(+) gradients, both in HEPES- and HCO(3)(-)/CO(2)-buffered media. Both acidification and alkalinisation were poorly sensitive to 4,4'-diisothiocyanate dihydrostilbene-2,2'-disulfonic acid, inhibitor of the anion ...
< 5 6 7 8 9 10 11 12 13 14 15 >