Functional constraints of nuclear-mitochondrial DNA interactions in xenomitochondrial rodent cell lines.
AuthorsDey R, Barrientos A, Moraes CT
JournalJ Biol Chem
PubMed ID10908562
'The co-evolution of nuclear and mitochondrial genomes in vertebrates led to more than 100 specific interactions that are crucial for an optimized ATP generation. These interactions have been examined by introducing rat mtDNA into mouse cells devoid of mitochondrial DNA (mtDNA). When mtDNA-less cells derived from the common mouse (Mus ... More
Rapid movements of vimentin on microtubule tracks: kinesin-dependent assembly of intermediate filament networks.
AuthorsPrahlad V, Yoon M, Moir RD, Vale RD, Goldman RD
JournalJ Cell Biol
PubMed ID9763428
'The assembly and maintenance of an extended intermediate filament (IF) network in fibroblasts requires microtubule (MT) integrity. Using a green fluorescent protein-vimentin construct, and spreading BHK-21 cells as a model system to study IF-MT interactions, we have discovered a novel mechanism involved in the assembly of the vimentin IF cytoskeleton. ... More
Inhibition of the bovine-heart mitochondrial F1-ATPase by cationic dyes and amphipathic peptides.
AuthorsBullough DA, Ceccarelli EA, Roise D, Allison WS
JournalBiochim Biophys Acta
PubMed ID2527062
'The bovine heart mitochondrial F1-ATPase is inhibited by a number of amphiphilic cations. The order of effectiveness of non-peptidyl inhibitors examined as assessed by the concentration estimated to produce 50% inhibition (I0.5) of the enzyme at pH 8.0 is: dequalinium (8 microM), rhodamine 6G (10 microM), malachite green (14 microM), ... More
Resolution of fluorescence correlation measurements.
AuthorsMeseth U, Wohland T, Rigler R, Vogel H
JournalBiophys J
PubMed ID10049342
'The resolution limit of fluorescence correlation spectroscopy for two-component solutions is investigated theoretically and experimentally. The autocorrelation function for two different particles in solution were computed, statistical noise was added, and the resulting curve was fitted with a least squares fit. These simulations show that the ability to distinguish between ... More
Fluorescent cationic probes of mitochondria. Metrics and mechanism of interaction.
AuthorsBunting JR, Phan TV, Kamali E, Dowben RM
JournalBiophys J
PubMed ID2605307
'Mitochondria strongly accumulate amphiphilic cations. We report here a study of the association of respiring rat liver mitochondria with several fluorescent cationic dyes from differing structural classes. Using gravimetric and fluorometric analysis of dye partition, we find that dyes and mitochondria interact in three ways: (a) uptake with fluorescence quenching, ... More
Restrained torsional dynamics of nuclear DNA in living proliferative mammalian cells.
AuthorsTramier M, Kemnitz K, Durieux C, Coppey J, Denjean P, Pansu RB, Coppey-Moisan M
JournalBiophys J
PubMed ID10777758
'Physical parameters, describing the state of chromatinized DNA in living mammalian cells, were revealed by in situ fluorescence dynamic properties of ethidium in its free and intercalated states. The lifetimes and anisotropy decays of this cationic chromophore were measured within the nuclear domain, by using the ultra-sensitive time-correlated single-photon counting ... More
Benzodiazepine binding studies on living cells: application of small ligands for fluorescence correlation spectroscopy.
AuthorsHegener O, Jordan R, Häberlein H
JournalBiol Chem
PubMed ID12530545
'We demonstrate the applicability of fluorescence correlation spectroscopy (FCS) for receptor binding studies using low molecular weight ligands on the membranes of living nerve cells. The binding of the benzodiazepine Ro 7-1986/602 (N-des-diethyl-fluorazepam), labeled with the fluorophore Alexa 532, to the benzodiazepine receptor was analyzed quantitatively at the membrane of ... More
Acidity effects on the fluorescence properties and adsorptive behavior of rhodamine 6G molecules at the air-water interface studied with confocal fluorescence microscopy.
AuthorsZheng XY, Wachi M, Harata A, Hatano Y
JournalSpectrochim Acta A Mol Biomol Spectrosc
PubMed ID15084327
'The effects of acidity on fluorescence originated from rhodamine 6G (R6G) molecules adsorbed at the air-water interface of extremely low-concentration aqueous solutions have been studied with confocal fluorescence microscopy. Similarities and differences in the observed acidity effects between R6G molecules at the interface and those in the bulk solution have ... More
Light quenching of fluorescence: a new method to control the excited state lifetime and orientation of fluorophores.
AuthorsLakowicz JR, Gryczynski I, Kusba J, Bogdanov V
JournalPhotochem Photobiol
PubMed ID7870760
'Experimental studies have recently demonstrated that fluorescence emission can be quenched by laser light pulses from modern high-repetition rate lasers, a phenomenon we call "light quenching." In this overview article, we describe the possible effects of light quenching on the steady-state and time-resolved intensity and anisotropy of fluorophores. One can ... More
Cytoplasmic transport in Drosophila ovarian follicles: the migration of microinjected fluorescent probes through intercellular bridges depends neither on electrical charge nor on external osmolarity.
AuthorsBohrmann J, Schill S
JournalInt J Dev Biol
PubMed ID9240567
'Using video-intensified fluorescence microscopy and a pseudocolor display of fluorescence intensity, we analyzed the distribution of microinjected molecules within the nurse-cell/oocyte syncytium of Drosophila ovarian follicles. We varied the composition and the osmolarity of the culture solution as well as the electrical charge and the molecular mass of the microinjected ... More
Candida glabrata ATP-binding cassette transporters Cdr1p and Pdh1p expressed in a Saccharomyces cerevisiae strain deficient in membrane transporters show phosphorylation-dependent pumping properties.
AuthorsWada S, Niimi M, Niimi K, Holmes AR, Monk BC, Cannon RD, Uehara Y
JournalJ Biol Chem
PubMed ID12244114
'The expression and drug efflux activity of the ATP binding cassette transporters Cdr1p and Pdh1p are thought to have contributed to the recent increase in the number of fungal infections caused by Candida glabrata. The function of these transporters and their pumping characteristics, however, remain ill defined. We have evaluated ... More
P-selectin mediates platelet-endothelial cell interactions and reperfusion injury in the mouse liver in vivo.
AuthorsKhandoga A, Biberthaler P, Enders G, Teupser D, Axmann S, Luchting B, Hutter J, Messmer K, Krombach F
JournalShock
PubMed ID12462561
'Platelets are suggested to participate in the pathogenesis of hepatic ischemia-reperfusion (I/R) injury. This study was designed to analyze platelet-endothelial cell interactions in the postischemic mouse liver in vivo and to define the role of endothelial versus platelet P-selectin for these interactions. Platelet-endothelial cell interactions were quantitatively analyzed using intravital ... More
The power of single and multibeam two-photon microscopy for high-resolution and high-speed deep tissue and intravital imaging.
AuthorsNiesner R, Andresen V, Neumann J, Spiecker H, Gunzer M,
JournalBiophys J
PubMed ID17557785
'Two-photon microscopy is indispensable for deep tissue and intravital imaging. However, current technology based on single-beam point scanning has reached sensitivity and speed limits because higher performance requires higher laser power leading to sample degradation. We utilize a multifocal scanhead splitting a laser beam into a line of 64 foci, ... More
In vivo fluorescence microscopy for the assessment of microvascular reperfusion injury in small bowel transplants in rats.
'With the use of in vivo fluorescence microscopy we have analyzed microvascular reperfusion injury of small bowel isograft transplants in rats. Following 1 hr cold storage in University of Wisconsin solution, the small bowel was transplanted heterotopically, and the intestinal microcirculation was quantitatively analyzed 20-60 min after onset of reperfusion. ... More
Spectra and fluorescence lifetimes of lissamine rhodamine, tetramethylrhodamine isothiocyanate, texas red, and cyanine 3.18 fluorophores: influences of some environmental factors recorded with a confocal laser scanning microscope.
AuthorsBrismar H, Trepte O, Ulfhake B
JournalJ Histochem Cytochem
PubMed ID7608524
'We report on the spectra and fluorescence lifetimes of four commonly used fluorophores: lissamine rhodamine (LRSC); tetramethyl rhodamine isothiocyanate (TRITC); Texas Red; and cyanine 3.18 (Cy-3). Fluorescence lifetime recordings revealed that these spectrally overlapping fluorophores can be individually detected by their lifetimes, indicating that at least four fluorophores can be ... More
Cerebral microvascular responses to hypercholesterolemia: roles of NADPH oxidase and P-selectin.
AuthorsIshikawa M, Stokes KY, Zhang JH, Nanda A, Granger DN
JournalCirc Res
PubMed ID14670846
'Although hypercholesterolemia is widely accepted as a major risk factor for coronary artery and peripheral vascular diseases, its role in the pathogenesis of stroke is controversial. The objectives of this study were to determine how hypercholesterolemia affects the cerebral microcirculation under resting conditions and after ischemia-reperfusion (I/R). Platelet- and leukocyte-endothelial ... More
Bioenergetics of the staphylococcal multidrug export protein QacA. Identification of distinct binding sites for monovalent and divalent cations.
AuthorsMitchell BA, Paulsen IT, Brown MH, Skurray RA
JournalJ Biol Chem
PubMed ID9920900
'The multidrug efflux pump QacA from Staphylococcus aureus confers resistance to an extensive range of structurally dissimilar compounds. Fluorimetric analyses demonstrated that QacA confers resistance to the divalent cation 4'',6-diamidino-2-phenylindole, utilizing a proton motive force-dependent efflux mechanism previously demonstrated for QacA-mediated resistance to the monovalent cation ethidium. Both the ionophores ... More
Effects of monensin and veratridine on acetylcholine release and cytosolic free Ca2+ levels in cerebrocortical synaptosomes of rats.
AuthorsSatoh E, Nakazato Y
JournalJ Neurochem
PubMed ID1895105
'Monensin (10(-8)-10(-4) M) caused a dose-dependent increase in the release of [3H]acetylcholine ([3H]ACh) from purified rat cerebrocortical synaptosomes, with an EC50 of approximately 1.6 x 10(-6) M. Extracellular Na+, but not Ca2+, was required for a monensin-induced increase in the release of [3H]ACh. Monensin also increased the cytosolic free Ca2+ ... More
A test of the singlet oxygen mechanism of cationic dye photosensitization of mitochondrial damage.
AuthorsBunting JR
JournalPhotochem Photobiol
PubMed ID1603852
'Aromatic cationic dyes have a potential as photo-chemotherapeutic agents because they are selectively concentrated into the mitochondria of cancerous cells. The mechanism of cytophototoxicity has been proposed to be primarily due to dye sensitized photogeneration of highly toxic singlet oxygen (1O2) at the mitochondria. We tested this hypothesis by measuring ... More
Thin-layer chromatography and electrospray mass spectrometry coupled using a surface sampling probe.
AuthorsVan Berkel GJ, Sanchez AD, Quirke JM
JournalAnal Chem
PubMed ID12510741
'A combined surface sampling probe/electrospray emitter was used for the direct readout of thin-layer chromatography plates by electrospray mass spectrometry. The technique was demonstrated with reversed-phase C18 plates using a three-dye mixture composed of methylene blue, crystal violet, and rhodamine 6G for positive ion mode detection and a separate dye ... More
The role of drug-lipid interactions in the biological activity of modulators of multi-drug resistance.
AuthorsWadkins RM, Houghton PJ
JournalBiochim Biophys Acta
PubMed ID7903866
'Of the compounds that have now been shown to circumvent acquired cellular multidrug resistance, little or no structure-activity relationship has been found, although their proposed mechanism of action is through modulation of function of p-glycoprotein. While it has been suggested that this inhibition is a direct binding to p-glycoprotein, we ... More
Prenyl-flavonoids as potent inhibitors of the Pdr5p multidrug ABC transporter from Saccharomyces cerevisiae.
AuthorsConseil G, Decottignies A, Jault JM, Comte G, Barron D, Goffeau A, Di Pietro A
JournalBiochemistry
PubMed ID10841772
'The Pdr5p multidrug ABC ("ATP-binding cassette) transporter was highly overexpressed in plasma membranes from a yeast strain exhibiting both pdr1-3 gain-of-function mutation in the transcription factor-encoding gene PDR1 and disruption of genes encoding other plasma membrane ABC transporters. Solubilized and purified Pdr5p displayed a tryptophan-characteristic intrinsic fluorescence, whose quenching was ... More
Model system for plant cell biology: GFP imaging in living onion epidermal cells.
AuthorsScott A, Wyatt S, Tsou PL, Robertson D, Allen NS
JournalBiotechniques
PubMed ID10376152
'The ability to visualize organelle localization and dynamics is very useful in studying cellular physiological events. Until recently, this has been accomplished using a variety of staining methods. However, staining can give inaccurate information due to nonspecific staining, diffusion of the stain or through toxic effects. The ability to target ... More
Coupling between proteolytic processing and translocation of the precursor of the F1-ATPase beta-subunit during its import into mitochondria of intact cells.
AuthorsKolarov J, Hatalová I
JournalFEBS Lett
PubMed ID6238846
'The intracellular transport of newly synthesized beta-subunits of the F1-ATPase (beta F1) and of newly synthesized ADP/ATP carrier was followed in isolated rat hepatoma cells. As tested by rapid fractionation of [35S]methionine pulse- and pulse-chase-labeled cells and by sensitivity of labeled polypeptides to externally added protease, the import of beta ... More
Intravital fluorescence microscopy and phototocicity: effects on leukocytes.
AuthorsHarris AG, Sinitsina I, Messmer K
JournalEur J Med Res
PubMed ID11953282
'The purpose of this investigation was to clarify whether the light exposure of fluorescently marked leukocytes and/or plasma influences the leukocyte behavior (rolling and firm adhesion). Anaesthetized Balb/c mice were laparotomized to expose the mesentery of the terminal ileum. Animals were randomly assigned to 5 experimental groups. One group was ... More
Nanochannels on a fused-silica microchip and liquid properties investigation by time-resolved fluorescence measurements.
AuthorsHibara A, Saito T, Kim HB, Tokeshi M, Ooi T, Nakao M, Kitamori T
JournalAnal Chem
PubMed ID12510735
'We have fabricated nanometer-sized channels, demonstrated a technique for the introduction of liquid into the channels, and carried out time-resolved fluorescence measurements of aqueous solutions. In this study, 330-nm- and 850-nm-sized channels were fabricated on fused-silica substrates by fast atom beam etching and hydrofluoric acid bonding methods. A liquid introduction ... More
Fluorescence correlation microscopy of cells in the presence of autofluorescence.
AuthorsBrock R, Hink MA, Jovin TM
JournalBiophys J
PubMed ID9788950
'Fluorescence correlation microscopy (FCM), the combination of fluorescence correlation spectroscopy (FCS) and digital microscopy (Brock and Jovin, 1998. Cell. Mol. Biol. 44:847-856), has been implemented for measuring molecular diffusion and association in living cells with explicit consideration of autocorrelations arising from autofluorescence. Autofluorescence excited at 532 nm colocalizes with mitochondria, ... More
Transport of the cationic fluorochrome rhodamine 123 in an insect's Malpighian tubule: indications of a reabsorptive function of the secondary cell type.
AuthorsMeulemans W, De Loof A
JournalJ Cell Sci
PubMed ID1629249
'The pathway of rhodamine 123 was examined after injection into Sarcophaga flies and after in vitro labeling of the Malpighian tubules. After in vitro labeling the primary cells only retained this potential-sensitive dye for a short period while all secondary cells accumulated the dye from the tubule lumen. In vivo ... More
Orientational and dynamical heterogeneity of rhodamine 6G terminally attached to a DNA helix revealed by NMR and single-molecule fluorescence spectroscopy.
AuthorsNeubauer H, Gaiko N, Berger S, Schaffer J, Eggeling C, Tuma J, Verdier L, Seidel CA, Griesinger C, Volkmer A,
JournalJ Am Chem Soc
PubMed ID17900110
'The comparison of Förster resonance energy transfer (FRET) efficiencies between two fluorophores covalently attached to a single protein or DNA molecule is an elegant approach for deducing information about their structural and dynamical heterogeneity. For a more detailed structural interpretation of single-molecule FRET assays, information about the positions as well ... More
Potentiation of the antiviral activity of poly r(A-U) by xanthene dyes.
AuthorsJamison JM, Krabill K, Hatwalkar A, Jamison E, Tsai CC
JournalCell Biol Int Rep
PubMed ID1964628
'Ten xanthene dyes (XAN) are evaluated for their ability to potentiate the antiviral activity of poly r(A-U) using a human foreskin fibroblast-vesicular stomatitis virus bioassay in which the XAN is combined with 0.2 mM poly r(A-U) to produce a XAN/ribonucleotide ratio of 1/4. Four of the ten XANs tested in ... More
Inhibition of in vitro growth of Plasmodium falciparum by a brief exposure to the cationic rhodamine dyes.
AuthorsIzumo A, Tanabe K
JournalAnn Trop Med Parasitol
PubMed ID3541806
'The effects of eight permeant fluorescent dyes on the in vitro growth of Plasmodium falciparum was investigated. First, P. falciparum-infected human erythrocytes were synchronized with D-sorbitol and treated with the cationic fluorescent dye rhodamine 123 at 37 degrees C for 30 minutes, and the growth of the treated parasites monitored ... More
The TF1-ATPase and ATPase activities of assembled alpha 3 beta 3 gamma, alpha 3 beta 3 gamma delta, and alpha 3 beta 3 gamma epsilon complexes are stimulated by low and inhibited by high concentrations of rhodamine 6G whereas the dye only inhibits the alpha 3 beta 3, and alpha 3 beta 3 delta complexes.
AuthorsPaik SR, Yokoyama K, Yoshida M, Ohta T, Kagawa Y, Allison WS
JournalJ Bioenerg Biomembr
PubMed ID8144495
'The ATPase activity of the F1-ATPase from the thermophilic bacterium PS3 is stimulated at concentrations of rhodamine 6G up to about 10 microM where 70% stimulation is observed at 36 degrees C. Half maximal stimulation is observed at about 3 microM dye. At rhodamine 6G concentrations greater than 10 microM, ... More
Fluorescent dye monitoring of mitochondrial changes associated with malignant cell transformation.
AuthorsHorikoshi T, Yoshioka T, Kubota Y, Yanagisawa K
JournalCell Struct Funct
PubMed ID2449289
'The fluorescent dyes, rhodamine 6G and 123, which specifically stain mitochondria, were used to examine changes in mitochondria that follow malignant transformation. The spatial distribution and shapes of mitochondria differ in untransformed and malignant-transformed cells. In untransformed C3H/10T1/2 clone 8 cells, the mitochondria were distributed radially around the nucleus, and ... More
Anticancer drugs, ionophoric peptides, and steroids as substrates of the yeast multidrug transporter Pdr5p.
AuthorsKolaczkowski M, van der Rest M, Cybularz-Kolaczkowska A, Soumillion JP, Konings WN, Goffeau A
JournalJ Biol Chem
PubMed ID8940170
'Pdr5p is the yeast Saccharomyces cerevisiae ATP-binding cassette transporter conferring resistance to several unrelated drugs. Its high overproduction in Pdr1p transcription factor mutants allows us to study the molecular mechanism of multidrug transport and substrate specificity. We have developed new in vivo and in vitro assays of Pdr5p-mediated drug transport. ... More
Effect of silver nano particles on the fluorescence quantum yield of Rhodamine 6G determined using dual beam thermal lens method.
AuthorsSanthi A, Umadevi M, Ramakrishnan V, Radhakrishnan P, Nampoori VP
JournalSpectrochim Acta A Mol Biomol Spectrosc
PubMed ID15084326
'Nano structured noble metals have very important applications in diverse fields as photovoltaics, catalysis, electronic and magnetic devices, etc. Here, we report the application of dual beam thermal lens technique for the determination of the effect of silver sol on the absolute fluorescence quantum yield (FQY) of the laser dye ... More
Interactions of molecular probes with living cells and tissues. Part 1. Some general mechanistic proposals, making use of a simplistic Chinese box model.
AuthorsHorobin RW, Rashid F
JournalHistochemistry
PubMed ID2358379
'A simple and generalised model-termed the simplistic Chinese box [SCB] model-for the interaction of molecular probes with living systems is described. The SCB model includes the following assumptions. That living systems may be considered as built from biologically defined boxes, e.g. whole cell, nucleus, nucleoli. That movement of molecular probes ... More
Detection of asymmetric PCR products in homogeneous solution by fluorescence correlation spectroscopy.
AuthorsKinjo M
JournalBiotechniques
PubMed ID9793656
'The yield of the double-stranded DNA product (500 bp) of asymmetric PCR with a rhodamine-labeled primer (Rho-primer) was determined in a homogeneous solution using fluorescence correlation spectroscopy (FCS). FCS provides the average number of molecules in a focused volume and the diffusion constant that relates the molecular weight. Since FCS ... More
Kinetic analysis of rhodamines efflux mediated by the multidrug resistance protein (MRP1).
AuthorsSaengkhae C, Loetchutinat C, Garnier-Suillerot A
JournalBiophys J
PubMed ID12944313
'Characterization of rhodamine 123 as functional assay for MDR has been primarily focused on P-glycoprotein-mediated MDR. Several studies have suggested that Rh123 is also a substrate for MRP1. However, no quantitative studies of the MRP1-mediated efflux of rhodamines have, up to now, been performed. Measurement of the kinetic characteristics of ... More
Nondestructive detection of gangliosides with lipophilic fluorochromes and their employment for preparative high-performance thin-layer chromatography.
AuthorsMüthing J, Heitmann D
JournalAnal Biochem
PubMed ID8434781
'A simple and effective procedure for the isolation and purification of gangliosides by preparative thin-layer chromatography is described. The method is based on nondestructive visualization of gangliosides on silica gel-precoated thin-layer chromatography plates by staining with uncharged lipophilic fluorochromes. Fluorescent dyes were added in low concentrations into the mobile phase ... More
C. elegans dynamin-related protein DRP-1 controls severing of the mitochondrial outer membrane.
AuthorsLabrousse AM, Zappaterra MD, Rube DA, van der Bliek AM
JournalMol Cell
PubMed ID10619028
'Little is known about the mechanism of mitochondrial division. We show here that mitochondria are disrupted by mutations in a C. elegans dynamin-related protein (DRP-1). Mutant DRP-1 causes the mitochondrial matrix to retract into large blebs that are both surrounded and connected by tubules of outer membrane. This indicates that ... More
One-step concentration of analytes based on dynamic change in pH in capillary zone electrophoresis.
AuthorsWei W, Xue G, Yeung ES
JournalAnal Chem
PubMed ID11924995
'A novel strategy for one-step concentration of analytes during capillary electrophoresis (CE) is presented. A short platinum wire was inserted into the 75-microm-i.d. separation capillary. When a high voltage was applied for CE separation, a sharp pH gradient along the capillary was created dynamically by the electrolysis of water in ... More
Rhodamine 6G. A potent inhibitor of mitochondrial oxidative phosphorylation.
AuthorsGear AR
JournalJ Biol Chem
PubMed ID4275428
Vital staining of Plasmodium falciparum with cationic fluorescent rhodamine dyes.
AuthorsKato M, Izumo A, Tanabe K
JournalJ Parasitol
PubMed ID2443630
Spectra and lifetimes of fluorescence resonance energy transfer fluorophores under two-photon excitation.
AuthorsAshman R, Crimeen-Irwin B, Ludford-Menting M, Russell S, Gu M
JournalScanning
PubMed ID12866644
We show two-photon spectra and lifetimes acquired using conventional confocal microscopes equipped with an ultra-short pulsed laser and a time-gated intensified charge coupled device. We report on the two-photon spectra and lifetimes of Alexa350, enhanced green fluorescent protein (EGFP), EGFP-CD46, and Cy3 labelled antibodies. Cellular and extracellular EGFP two-photon spectra ... More
Single-molecule fluorescence observed with mercury lamp illumination.
AuthorsUnger M, Kartalov E, Chiu CS, Lester HA, Quake SR
JournalBiotechniques
PubMed ID10572649
We demonstrate that it is possible to observe single fluorescent molecules using a standard fluorescence microscope with mercury lamp excitation and an inexpensive cooled charge-coupled device (CCD) camera. With this equipment, we have been able to observe single molecules of tetramethyl-rhodamine, rhodamine 6G, fluorescein isothiocyanate and green fluorescent protein. Immobilized ... More
Mitochondrial membrane potential in living cells: evidence from studies with rhodamine 6 G as fluorescent probe.
AuthorsDietzmann K, Letko G, Sokolowski A
JournalExp Pathol
PubMed ID3569481
Rhodamine 6 G as a cationic permeant fluorophore is demonstrated to be selectively accumulated by mitochondria of living pancreatic acinar cells from guinea pigs. The accumulation of the fluorescent dye was studied by means of the application of electron transport inhibitors in the respiratory chain, ionophores and some hydrogen donors. ... More
Novel screening method for agents that overcome classical multidrug resistance in a human cell line.
AuthorsYoshimura A, Shudo N, Ikeda SI, Ichikawa M, Sumizawa T, Akiyama SI
JournalCancer Lett
PubMed ID1969768
P-glycoprotein (P-gp) is involved in the transport of a wide variety of organic compounds including a fluorescent dye, rhodamine 6G (RG), as well as anti-cancer drugs. Agents that overcome classical multidrug-resistance (MDR) increased the accumulation of RG in a MDR cell line, KB-C1. The effect of agents on RG-accumulation in ... More
Mitochondrial fluorescence patterns in rhodamine 6G-stained myocardial cells in vitro. Analysis by real-time computer video microscopy and laser microspot excitation.
AuthorsBerns MW, Siemens AE, Walter RJ
JournalCell Biophys
PubMed ID6085560
Cellular fluorescence in vitro has been studied employing a low light-level video system interfaced with a real-time image array-processing computer system. Changes in cytoplasmic (mitochondrial) fluorescence in myocytes employing the probe rhodamine 6G have been studied over real time with the aid of several computer-based programs. An oscillating pattern of ... More
Fluorescence correlation spectroscopy: diagnostics for sparse molecules.
AuthorsMaiti S, Haupts U, Webb WW
JournalProc Natl Acad Sci U S A
PubMed ID9342306
The robust glow of molecular fluorescence renders even sparse molecules detectable and susceptible to analysis for concentration, mobility, chemistry, and photophysics. Correlation spectroscopy, a statistical-physics-based tool, gleans quantitative information from the spontaneously fluctuating fluorescence signals obtained from small molecular ensembles. This analytical power is available for studying molecules present at ... More
Single-molecule identification by spectrally and time-resolved fluorescence detection
AuthorsPrummer M, Hubner CG, Sick B, Hecht B, Renn A, Wild UP
JournalAnal Chem
PubMed ID10695126
A method to identify single molecules rapidly and with high efficiency based on simple probability considerations is proposed. In principle, any property of a detected photon in a single-molecule fluorescence experiment, e.g., emission wavelength, arrival time after pulsed excitation, and polarization, can be analyzed within the framework of the outlined ... More
Effects of the mitochondrial probe rhodamine 123 and related analogs on the function and viability of pulsating myocardial cells in culture.
AuthorsLampidis TJ, Salet C, Moreno G, Chen LB
JournalAgents Actions
PubMed ID6475672
Rhodamine 123, a cationic fluorescent dye, has previously been shown to specifically localize in or on mitochondria in living cells. Since it has also been shown to be relatively non-toxic in a variety of cell types it has been a useful tool for probing mitochondria in vitro. In this report, ... More
Photoablating neuronal groups using an intracellularly aggregating dye.
AuthorsGarber S, Camhi JM
JournalNeuroreport
PubMed ID1893091
We report here on a new method to kill several selected neurons, using a modified fluorescence photoablation technique that does not require impaling any cells. Rather, we injected extracellularly the dye rhodamine 6-G, which is taken up by the cells. We made our injections into one side of a cockroach ... More
Direct measurement of single-molecule diffusion and photodecomposition in free solution.
AuthorsXu XH, Yeung ES
JournalScience
PubMed ID9027307
Continuous monitoring of submillisecond free-solution dynamics of individual rhodamine-6G molecules and 30-base single-stranded DNA tagged with rhodamine was achieved. Fluorescence images were recorded from the same set of isolated molecules excited either through the evanescent field at the quartz-liquid interface or as a thin layer of solution defined by micron-sized ... More
Total internal reflection-based biochip utilizing a polymer-filled cavity with a micromirror sidewall.
AuthorsChronis N, Lee LP
JournalLab Chip
PubMed ID15052352
A total internal reflection (TIR)-based biochip utilizing a polymer-filled cavity with a micromirror sidewall has been designed and fabricated. The implementation of the micromirror sidewall cavity facilitates precise alignment of the excitation light beam into the system. The incident angle of illumination can be easily modified by selecting polymers of ... More
Uptake of fluorescent dyes associated with the functional expression of the cystic fibrosis transmembrane conductance regulator in epithelial cells.
AuthorsWersto RP, Rosenthal ER, Crystal RG, Spring KR
JournalProc Natl Acad Sci U S A
PubMed ID8577734
Specific mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), the most common autosomal recessive fatal genetic disease of Caucasians, result in the loss of epithelial cell adenosine 3',5'-cyclic-monophosphate (cAMP)-stimulated Cl- conductance. We show that the influx of a fluorescent dye, dihydrorhodamine 6G (dR6G), is increased in cells expressing human ... More
Strategies to improve photostabilities in ultrasensitive fluorescence spectroscopy.
AuthorsWidengren J, Chmyrov A, Eggeling C, Löfdahl PA, Seidel CA,
JournalJ Phys Chem A
PubMed ID17228891
Given the particular importance of dye photostability for single-molecule and fluorescence fluctuation spectroscopy investigations, refined strategies were explored for how to chemically retard dye photobleaching. These strategies will be useful for fluorescence correlation spectroscopy (FCS), fluorescence-based confocal single-molecule detection (SMD) and related techniques. In particular, the effects on the addition ... More
Pulmonary absorption of aerosolized fluorescent markers in the isolated rabbit lung.
AuthorsLahnstein K, Schmehl T, Rüsch U, Rieger M, Seeger W, Gessler T,
JournalInt J Pharm
PubMed ID17980981
For the development of aerosolized controlled release formulations such as liposomes or nanoparticles, the use of suitable model drugs is necessary. This study compared the pulmonary absorption of the three structurally diverse fluorescent markers 5(6)-carboxyfluorescein (CF), 8-methoxypyrene-1,3,6-trisulfonic acid trisodium salt (MPTS) and rhodamine 6G (R6G) after nebulization in an isolated, ... More
Weak base permeability characteristics influence the intracellular sequestration site in the multidrug-resistant human leukemic cell line HL-60.
AuthorsDuvvuri M, Gong Y, Chatterji D, Krise JP,
JournalJ Biol Chem
PubMed ID15181006
A number of organelles contained within mammalian cells have been implicated in the selective sequestration of chemical entities including drug molecules. Specifically, weakly basic molecules have been shown to selectively associate with either the mitochondrial compartment or lysosomes; however, the structural basis for this differentiation has not been understood. To ... More
Laser-stimulated fluorescence of submicrometer regions within single mitochondria of rhodamine-treated myocardial cells in culture.
AuthorsSiemens A, Walter R, Liaw LH, Berns MW
JournalProc Natl Acad Sci U S A
PubMed ID6952198
A focused laser beam of 442 nm was used to stimulate fluorescence in 0.5-micrometer spots in single mitochondria of myocardial and endothelial cells in culture. Cells were treated with rhodamine 6G or 123 in order to render the mitochondria fluorescent. Rhodamine 123-treated cells exhibited a gradual decrease in fluorescence over ... More
Monitoring of relative mitochondrial membrane potential in living cells by fluorescence microscopy.
AuthorsJohnson LV, Walsh ML, Bockus BJ, Chen LB
JournalJ Cell Biol
PubMed ID6783667
Permeant cationic fluorescent probes are shown to be selectively accumulated by the mitochondria of living cells. Mitochondria-specific interaction of such molecules is apparently dependent on the high trans-membrane potential (inside negative) maintained by functional mitochondria. Dissipation of the mitochondrial trans-membrane and potential by ionophores or inhibitors of electron transport eliminates ... More
Single-molecule analysis of restriction DNA fragments using fluorescence correlation spectroscopy.
AuthorsKinjo M, Nishimura G, Koyama T, Mets Rigler R
JournalAnal Biochem
PubMed ID9657874
The cleavage of fluorescence-labeled M13DNA (7250 bp) using HaeIII, HgaI, BsmAI, and BspMI was analyzed by fluorescence correlation spectroscopy (FCS) in a small volume (1.5 x 10(-15) liters). The digestion process can be monitored by the decrease in amplitude of the fluorescence correlation function while the original DNA molecule is ... More
Ultrasensitive hybridization analysis using fluorescence correlation spectroscopy.
AuthorsKinjo M, Rigler R
JournalNucleic Acids Res
PubMed ID7784185
The hybridization of fluorescently tagged 18mer deoxyribonucleotides with complementary DNA templates was analysed by fluorescence correlation spectroscopy (FCS) in a droplet under an epi-illuminated fluorescence microscope at the level of single molecules. The interaction can be monitored by the change in the translational diffusion time of the smaller (18mer) primer ... More
Fluorimetry of mitochondria in cells vitally stained with DASPMI or rhodamine 6 GO.
AuthorsBereiter-Hahn J, Seipel KH, Vöth M, Ploem JS
JournalCell Biochem Funct
PubMed ID6205786
The fluorescent dyes DASPMI and rhodamine 6 GO specifically stain mitochondria in living cells. Dye concentrations from 10(-8) to 5 X 10(-6) mole l-1 can be used. Excitation and emission spectra, and quantum efficiency of DASPMI depend on solvent characteristics. Spectra of mitochondria in living cells correspond to those in ... More
Effect of glucose and pyruvate metabolism on membrane potential in synaptosomes.
AuthorsAiuchi T, Matsunaga M, Daimatsu T, Nakaya K, Nakamura Y
JournalBiochim Biophys Acta
PubMed ID6704397
Fluorescence changes of rhodamine 6G in synaptosomal suspension, which are correlated to changes in membrane potential in synaptosomes, were measured in the presence of various monosaccharides and organic acids. Addition of D-glucose, D-mannose, pyruvate and L-lactate hyperpolarized the membrane potential, whereas D-fructose, L-glucose, D-galactose, citrate, succinate and L-glutamate were without ... More
Probing single molecules in single living cells.
AuthorsByassee TA, Chan WC, Nie S
JournalAnal Chem
PubMed ID11101238
Single-molecule detection in single living cells has been achieved by using confocal fluorescence microscopy and externally tagged probe molecules. The intracellular background fluorescence is substantially higher than that in aqueous buffer, but this background is continuous and stable and does not significantly interfere with the measurement of single-molecule photon bursts. ... More
Applications of fluorescence correlation spectroscopy: measurement of size-mass relationship of native and denatured schizophyllan.
AuthorsLeng X, Starchev K, Buffle J
JournalBiopolymers
PubMed ID11473353
Diffusion dynamics of a polysaccharide, schizophyllan has been studied by fluorescence correlation spectroscopy (FCS). Several different sizes of nondenatured and denatured schizophyllan have been labeled with rhodamine 6G in borate buffer. The length of the nondenatured schizophyllan was calculated from FCS data by using the Broersma's relationship for rod-like macromolecules. ... More
Stacking due to ionic transport number mismatch during sample sweeping on microchips.
AuthorsLiu Y, Foote RS, Jacobson SC, Ramsey JM
JournalLab Chip
PubMed ID15791345
Sample stacking can occur in isoconductive buffer systems as a result of ion transport mismatches that cause changes in buffer conductivity during electrophoresis. Fluorescence imaging was used to examine this effect in the sweeping of hydrophobic dyes with sodium dodecyl sulfate (SDS) on microchips. Imaging revealed the occurrence of a ... More
Interaction of molecular probes with living cells and tissues. Part 2. A structure-activity analysis of mitochondrial staining by cationic probes, and a discussion of the synergistic nature of image-based and biochemical approaches.
AuthorsRashid F, Horobin RW
JournalHistochemistry
PubMed ID1698190
Cultured rat fibroblasts were exposed to 41 cationic fluorescent probes of very varied hydrophilicity/lipophilicity. Outcome of probe-cell interaction fell into one of the following categories: probe failed to enter the cells; probe accumulated on cell surfaces; probe accumulated in mitochondria, and/or in other intracellular regions. The observations were analysed using ... More
The fluorescent cationic dye rhodamine 6G as a probe for membrane potential in bovine aortic endothelial cells.
AuthorsMandalà M, Serck-Hanssen G, Martino G, Helle KB
JournalAnal Biochem
PubMed ID10527490
The membrane potential of cultured bovine aortic endothelial cells was assessed by a fluorescent probe as an alternative to direct methods. We used the fluorescent cationic dye rhodamine 6G, a lipophilic probe with high permeability in cell membranes. A linear relationship was obtained between fluorescence intensity (F.I.) and membrane potential ... More
Two-photon thermal bleaching of single fluorescent molecules.
AuthorsChirico G, Cannone F, Baldini G, Diaspro A
JournalBiophys J
PubMed ID12524312
We have studied the fluorescence emission by two-photon excitation of four dyes widely used for bioimaging studies, rhodamine 6G, fluorescein, pyrene and indo-1 at the single molecule level. The single dye molecules, spread on a glass substrate by spin coating, show a constant fluorescence output until a sudden transition to ... More
Characterization of the multidrug efflux regulator AcrR from Escherichia coli.
AuthorsSu CC, Rutherford DJ, Yu EW
JournalBiochem Biophys Res Commun
PubMed ID17644067
The Escherichia coli AcrR represses transcription of the acrB gene, which encodes the multidrug efflux pump AcrB that extrudes a wide variety of toxic compounds, by binding its target operator DNA. Fluorescence polarization was performed using purified, recombinant AcrR that contains a 6xHis tag at the C-terminus and a fluorescein-labeled ... More
On the stator of rotary ATP synthase: the binding strength of subunit delta to (alpha beta)3 as determined by fluorescence correlation spectroscopy.
AuthorsHäsler K, Pänke O, Junge W
JournalBiochemistry
PubMed ID10521283
ATP synthase is conceived as a rotary enzyme. Proton flow drives the rotor (namely, subunits c12 epsilon gamma) relative to the stator (namely, subunits ab2 delta(alpha beta)3) and extrudes spontaneously formed ATP from three symmetrically arranged binding sites on (alpha beta)3 into the solution. We asked whether the binding of ... More
Simultaneous imaging of cell and mitochondrial membrane potentials.
The distribution of charged membrane-permeable molecular probes between intracellular organelles, the cytoplasm, and the outside medium is governed by the relative membrane electrical potentials of these regions through coupled equilibria described by the Nernst equation. A series of highly fluorescent cationic dyes of low membrane binding and toxicity (Ehrenberg, B., ... More
Human cell variants resistant to rhodamine 6G.
AuthorsWiseman A, Fields TK, Chen LB
JournalSomat Cell Mol Genet
PubMed ID3865382
Two variants have been isolated from the cultured human cell line VA2-B which are resistant in vivo to the mitochondrial-specific fluorescent dyes rhodamine 6G and rhodamine 123. Both mutants are cross-resistant to ethidium bromide but are sensitive to both colchicine and chloramphenicol. When either mutant is treated with low levels ... More
Functional studies of the kidney of living animals using multicolor two-photon microscopy.
AuthorsDunn KW, Sandoval RM, Kelly KJ, Dagher PC, Tanner GA, Atkinson SJ, Bacallao RL, Molitoris BA
JournalAm J Physiol Cell Physiol
PubMed ID12176747
Optical microscopy, when applied to living animals, provides a powerful means of studying cell biology in the most physiologically relevant setting. The ability of two-photon microscopy to collect optical sections deep into biological tissues has opened up the field of intravital microscopy to high-resolution studies of the brain, lens, skin, ... More
We introduce dual-color time-integrated fluorescence cumulant analysis (TIFCA) to analyze fluorescence fluctuation spectroscopy data. Dual-color TIFCA utilizes the bivariate cumulants of the integrated fluorescent intensity from two detection channels to extract the brightness in each channel, the occupation number, and the diffusion time of fluorophores simultaneously. Detecting the fluorescence in ... More
Fluorescence quantum yields and their relation to lifetimes of rhodamine 6G and fluorescein in nine solvents: improved absolute standards for quantum yields.
AuthorsMagde D, Wong R, Seybold PG
JournalPhotochem Photobiol
PubMed ID12003120
Absolute fluorescence quantum yields are reported for the rhodamine 6G cation and the fluorescein dianion dyes in nine solvents. This information is combined with previously reported fluorescence lifetimes to deduce radiative and nonradiative decay rates. Along the alcohol series from methanol to octanol, rhodamine 6G displays an increasing radiative rate, ... More
Reactive oxygen species mediate leukocyte-endothelium interactions in prostaglandin F2alpha -induced luteolysis in rats.
AuthorsMinegishi K, Tanaka M, Nishimura O, Tanigaki S, Miyakoshi K, Ishimoto H, Yoshimura Y
JournalAm J Physiol Endocrinol Metab
PubMed ID12388163
We investigated the contribution of neutrophils to prostaglandin (PG)F(2 alpha)-induced luteolysis and the role of reactive oxygen species (ROS) as potential mediators of neutrophil accumulation in regressing corpora lutea of superovulated rats. On day 8 of pseudopregnancy, subcutaneous injection of PGF(2 alpha) (500 microg) significantly increased rhodamine 6G-labeled leukocyte adhesion ... More
Rhodamine B, a fluorescent probe for acidic organelles in denervated skeletal muscle.
AuthorsVult von Steyern F, Josefsson JO, Tågerud S
JournalJ Histochem Cytochem
PubMed ID8648087
We describe a very efficient method for fluorescent labeling of acidic structures in denervated skeletal muscle with rhodamine B. Rhodamine B at 50 ng/ml gave selective and distinct segmental labeling of denervated muscle fibers after 5-min incubation at room temperature. Labeling was also achieved at 4 degrees C. The labeling ... More
Characterization of visible dyes for four-decay fluorescence detection in DNA sequencing.
AuthorsNunnally BK, He H, Li LC, Tucker SA, McGown LB
JournalAnal Chem
PubMed ID9212706
Dyes of several classes were investigated as candidates for use in a multiplex, four-decay fluorescence detection scheme for DNA sequencing. The dyes include nitrobenzofuran dyes, rhodamine dyes, fluorescein dyes, cyanine dyes, Nile Red, and BODIPY dyes. Based on the results of fluorescence spectral and lifetime studies, an initial set of ... More
Two-photon microscopy and spectroscopy based on a compact confocal scanning head.
AuthorsDiaspro A, Chirico G, Federici F, Cannone F, Beretta S, Robello M
JournalJ Biomed Opt
PubMed ID11516320
We have combined a confocal laser scanning head modified for TPE (two-photon excitation) microscopy with some spectroscopic modules to study single molecules and molecular aggregates. The behavior of the TPE microscope unit has been characterized by means of point spread function measurements and of the demonstration of its micropatterning abilities. ... More
Estimation of the sarcoplasmic reticulum Ca2+ release flux underlying Ca2+ sparks.
AuthorsSoeller C, Cannell MB
JournalBiophys J
PubMed ID11964229
Using a combination of experimental and numerical approaches, we have tested two different approaches to calculating the sarcoplasmic reticulum (SR) Ca2+ release flux, which gives rise to cardiac muscle Ca2+ sparks. By using two-photon excited spot photolysis of DM-Nitrophen, known Ca2+ release flux time courses were generated to provide the ... More
Study of ligand-receptor interactions by fluorescence correlation spectroscopy with different fluorophores: evidence that the homopentameric 5-hydroxytryptamine type 3As receptor binds only one ligand.
AuthorsWohland T, Friedrich K, Hovius R, Vogel H
JournalBiochemistry
PubMed ID10393542
The 5-hydroxytryptamine receptor of type 3 was investigated by fluorescence correlation spectroscopy (FCS). Binding constants of fluorescently labeled ligands, the stoichiometry, and the mass of the receptor are readily accessible by this technique, while the duration of measurement is on the order of seconds to minutes. The receptor antagonist 1,2,3, ... More
Characteristics of leucocyte adhesion directly observed in flowing whole blood in vitro.
AuthorsAbbitt KB, Nash GB
JournalBr J Haematol
PubMed ID11167784
Use of whole blood in adhesion assays allows analysis of the rheological and haematological factors that may influence adhesion, and avoids the need for isolation procedures that may modify the properties of leucocytes. We have adapted an in vitro flow model to allow videomicroscopy of leucocytes fluorescently labelled with rhodamine ... More
Glycerol attenuates the adherence of leukocytes in rat pial venules after transient middle cerebral artery occlusion.
AuthorsIshikawa M, Sekizuka E, Sato S, Yamaguchi N, Inamasu J, Kawase T
JournalNeurol Res
PubMed ID10596390
Intravenous infusion of glycerol has been used in patients with a cerebral infarction, expecting improvement in brain edema and cerebral blood flow (CBF). However, the mechanism of the improvement of CBF has not been clearly demonstrated. The aim of this study in the rat pial microvasculature after transient middle cerebral ... More
Simultaneous measurements of cytosolic and mitochondrial Ca2+ transients in HT29 cells.
AuthorsRicken S, Leipziger J, Greger R, Nitschke R
JournalJ Biol Chem
PubMed ID9857027
Loading of HT29 cells with the Ca2+ dye fura-2/AM resulted in an nonhomogeneous intracellular distribution of the dye. Cellular compartments with high fura-2 concentrations were identified by correlation with mitochondrial markers, cellular autofluorescence induced by UV, and dynamic measurement of autofluorescence after inhibition of oxidative phosphorylation. Stimulation with carbachol (10(-4) ... More
Macrophage phagocytosis of biodegradable microspheres composed of L-lactic acid/glycolic acid homo- and copolymers.
AuthorsTabata Y, Ikada Y
JournalJ Biomed Mater Res
PubMed ID3220838
A variety of biodegradable microspheres were prepared from L-lactic acid, DL-lactic acid, or glycolic acid homopolymers and copolymers of different molecular weights and monomer compositions. Phagocytosis of the microspheres by mouse peritoneal macrophages was studied in cell culture system using scanning electron microscopy as well as light microscopy. The diameter ... More
Genetic separation of FK506 susceptibility and drug transport in the yeast Pdr5 ATP-binding cassette multidrug resistance transporter.
AuthorsEgner R, Rosenthal FE, Kralli A, Sanglard D, Kuchler K
JournalMol Biol Cell
PubMed ID9450972
Overexpression of the yeast Pdr5 ATP-binding cassette transporter leads to pleiotropic drug resistance to a variety of structurally unrelated cytotoxic compounds. To identify Pdr5 residues involved in substrate recognition and/or drug transport, we used a combination of random in vitro mutagenesis and phenotypic screening to isolate novel mutant Pdr5 transporters ... More
Intrinsic fluorescence of the P-glycoprotein multidrug transporter: sensitivity of tryptophan residues to binding of drugs and nucleotides.
AuthorsLiu R, Siemiarczuk A, Sharom FJ
JournalBiochemistry
PubMed ID11101309
P-glycoprotein is a member of the ATP binding cassette family of membrane proteins, and acts as an ATP-driven efflux pump for a diverse group of hydrophobic drugs, natural products, and peptides. The side chains of aromatic amino acids have been proposed to play an important role in recognition and binding ... More
Direct observation of sub-picosecond equilibration of excitation energy in the light-harvesting antenna of Rhodospirillum rubrum.
AuthorsVisser HM, Somsen OJ, van Mourik F, Lin S, van Stokkum IH, van Grondelle R
JournalBiophys J
PubMed ID8519962
Excitation energy transfer in the light-harvesting antenna of Rhodospirillum rubrum was studied at room temperature using sub-picosecond transient absorption measurements. Upon excitation of Rs. rubrum membranes with a 200 fs, 600 nm laser flash in the Qx transition of the bacteriochlorophyll-a (BChl-a) absorption, the induced transient absorption changes in the ... More
Relevance of the chemical charge of rhodamine dyes to multiple drug resistance.
AuthorsLampidis TJ, Castello C, del Giglio A, Pressman BC, Viallet P, Trevorrow KW, Valet GK, Tapiero H, Savaraj N
JournalBiochem Pharmacol
PubMed ID2597199
Previously, we have shown that multiple drug resistant (MDR) Friend leukemia cells (FLC) are cross-resistant to the positively-charged dye, Rhodamine 123 (Rho 123), and that this resistance can be reversed by verapamil (VER). In the present study we used two zwitterionic rhodamine analogs, Rhodamine 116 and Rhodamine 110, and another ... More
Conformation of xanthene dyes in the sulfhydryl 1 binding site of myosin. 2.
AuthorsAjtai K, Burghardt TP
JournalBiochemistry
PubMed ID8519751
The fluorescent dyes 5'-(iodoacetamido)tetramethylrhodamine (5'IATR) and 5'-(iodoacetamido)-fluorescein (5'IAF) bind covalently to the reactive sulfhydryl (SH1) of myosin subfragment 1 (S1), the 5'IATR as a dimer and the 5'IAF as a monomer. The conformation of the dimer and the dye-protein complex was investigated by comparison of several spectroscopic signals of the ... More
Effect of ischemia-reperfusion injury on the microcirculation of the steatotic liver of the Zucker rat.
AuthorsSun CK, Zhang XY, Zimmermann A, Davis G, Wheatley AM
JournalTransplantation
PubMed ID11726821
BACKGROUND: Much discussion has been focused on the use of steatotic livers for transplantation due to the prevalence of steatosis in the potential donor liver pool (1). The aim of this study was to investigate the possibility that the microcirculation of steatotic liver is more sensitive to the ischemia-reperfusion (IR) ... More
Efficiency of P-glycoprotein-mediated exclusion of rhodamine dyes from multidrug-resistant cells is determined by their passive transmembrane movement rate.
The aim of the present study was to examine the relationship between the rate of the passive transmembrane movement of multidrug resistance (MDR)-type substrates and the ability of P-glycoprotein to extrude them from MDR cells. For this purpose, seven rhodamine dyes were examined for their P-glycoprotein-mediated exclusion from MDR cells, ... More
Inhibition of mitochondrial respiration by cationic rhodamines as a possible teratogenicity mechanism.
AuthorsRanganathan S, Churchill PF, Hood RD
JournalToxicol Appl Pharmacol
PubMed ID2728000
Exposure of mice to cationic rhodamines, Rh 123 and Rh 6G, has been found to be associated with developmental toxicity, while neutral rhodamines (e.g., Rh B) had no such effect. When mouse embryos from dams given ip injections of Rh 123, Rh 6G (15 mg/kg), or Rh B (30 mg/kg) ... More
New insights into the P-glycoprotein-mediated effluxes of rhodamines.
AuthorsLoetchutinat C, Saengkhae C, Marbeuf-Gueye C, Garnier-Suillerot A
JournalEur J Biochem
PubMed ID12542697
Multidrug resistance (MDR) in tumour cells is often caused by the overexpression of the plasma drug transporter P-glycoprotein (P-gp). This protein is an active efflux pump for chemotherapeutic drugs, natural products and hydrophobic peptides. Despite the advances of recent years, we still have an unclear view of the molecular mechanism ... More
Digital video-imaging of leukocyte migration in the iris: intravital microscopy in a physiological model during the onset of endotoxin-induced uveitis.
AuthorsBecker MD, Nobiling R, Planck SR, Rosenbaum JT
JournalJ Immunol Methods
PubMed ID10854598
The process of inflammation is accompanied by an alteration of leukocyte-endothelial dynamics. Reciprocal changes in the endothelium and the white cell permit the leukocyte to relinquish its normal free-flowing state in order to roll, arrest, and emigrate through the endothelium. Although intravital microscopy is an established method to observe this ... More
Mechanisms of azole resistance in petite mutants of Candida glabrata.
We previously showed that resistant colonies of Candida glabrata inside the azole inhibition zones had respiratory deficiency due to mutations in mitochondrial DNA. Here, we analyzed the mechanisms of azole resistance in petite mutants of C. glabrata obtained by exposure to fluconazole or induced by ethidium bromide. The respiratory deficiency ... More
Differential localization of protein kinase C delta by phorbol esters and related compounds using a fusion protein with green fluorescent protein.
Enzyme localization often plays a controlling role in determining its activity and specificity. Protein kinase C (PKC) has long been known to translocate in response to physiological stimuli as well as to exogenous ligands such as the phorbol esters. We report here that different phorbol derivatives and related ligands, selected ... More