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Results 351 - 400 of 1715
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Wozniak Richard W - - 2008
In this issue of Developmental Cell, Chakraborty et al. report that efficient advancement through G1/S phase requires the downregulation of Nup96 levels during M phase. The authors show that oscillations in Nup96 levels plays a key role in maintaining normal cell proliferation, likely by regulating the export of specific mRNAs, ...
Tychinsky Vladimir P - - 2008
We develop a method of coherent phase microscopy (CPM) for direct visualization of nonfixed, nonstained mammalian cells (both cultured cells and freshly isolated tumor biopsies) followed by computer-assisted data analysis. The major purpose of CPM is to evaluate the refractive properties of optically dense intracellular structures such as the nucleus ...
Whitcomb Elizabeth A - - 2009
Timely degradation of regulatory proteins by the ubiquitin proteolytic pathway (UPP) is an established paradigm of cell cycle regulation during the G2/M and G1/S transitions. Less is known about roles for the UPP during S phase. Here we present evidence that dynamic cell cycle-dependent changes in levels of UbcH7 regulate ...
Starheim Kristian K - - 2008
Protein N(alpha)-terminal acetylation is a conserved and widespread protein modification in eukaryotes. Several studies have linked it to normal cell function and cancer development, but nevertheless, little is known about its biological function. In yeast, protein N(alpha)-terminal acetylation is performed by the N-acetyltransferase complexes NatA, NatB and NatC. In humans, ...
Ito Syunsuke - - 2009
The simultaneous determination of the cell cycle phase of individual adherent Chinese hamster ovary cells using a fluorescence microscope after staining with 4',6-diamidine-2'-phenylindole dihydrochloride and bromodeoxyuridine and the laser phase shift by a phase-shifting laser microscopy revealed that the laser phase shift of cells in the G2/M phase was markedly ...
Pfeuty Benjamin - - 2008
Upon their exit from mitosis, mammalian cells enter a G(1) phase during which they acutely sense all sorts of environmental stimuli. On the basis of these signals that they first need to decipher and integrate, they decide whether to undergo division, differentiation, senescence or apoptosis. We questioned whether, despite the ...
Dagenais-Bellefeuille Steve - - 2008
In many phytoplankton species, cell division (mitosis) usually occurs at defined times of day. This timing is also observed under constant conditions, indicating that it is regulated by a circadian clock rather than by a simple response to the light-dark cycle. For those algae with cell cycles longer than a ...
Tashima Yoshihiko - - 2008
Control of the G1/S phase transition of the cell cycle contributes to the maintenance of homeostasis. It is well known that the disruption of the cell cycle is related to cell transformation and carcinogenesis. The G1/S phase transition involves a network of components that includes cyclins, cyclin-dependent kinases, and other ...
Meier, Johannes
“Compensated” microcrystalline silicon is obtained by adding 8-20 ppm diborane in the plasma gas phase. p-i-n cells with such i-layers have increased infrared sensitivity when compared to a-Si:H p-i-n cells. The preparation of the world's first “mixed stacked” a-Si:H/μc-Si:H tandem cell with an initial efficiency of 9.1% is reported. The ...
Bongrand, Pierre
Blood leukocytes can exhibit extensive morphological changes during their passage through small capillary vessels. The human monocytic THP-1 cell line was used to explore the metabolic dependence of these shape changes. Cells were aspirated into micropipettes for determination of the rate of protrusion formation. They were then released and the ...
Yuan Zhanjiang - - 2008
An ensemble of stochastic genetic relaxation oscillators via phase-attractive or repulsive cell-to-cell communication are investigated. In the phase-attractive coupling case, it is found that cellular communication can enhance self-induced stochastic resonance as well as collective rhythms, and that different intensities of noise resulting from the fluctuation of intrinsic chemical reactions ...
Wahl Aljoscha - - 2008
Up to now cell-culture based vaccine production processes only reach low productivities. The reasons are: (i) slow cell growth and (ii) low cell concentrations. To address these shortcomings, a quantitative analysis of the process conditions, especially the cell growth and the metabolic capabilities of the host cell line is required. ...
Ahmad Mohd Ridzuan - - 2008
We performed in situ measurements of mechanical properties of individual W303 wild-type yeast cells by using an integrated environmental scanning electron microscope (ESEM)-nanomanipulator system. Compression experiments to penetrate the cell walls of single cells of different cell sizes (about 3-6 micro m diameter), environmental conditions (600 Pa and 3 mPa), ...
De Jesús Antonio J - - 2008
In previous studies, the growth of L. monocytogenes has been modeled under different CO2 headspace concentrations; however, the inoculum cells were always in the stationary phase. In this study, the growth of L. monocytogenes under different CO2 concentrations as affected by the physiological state of the cells was investigated. Exponential-growth-phase, ...
Cronin Ultan P - - 2008
The physiological status and metabolic heterogeneity of Bacillus cereus cells within a culture during an 8-h batch fermentation process was measured using flow cytometry (FCM). Concurrently, production of the toxin, PC-PLC, and the extent of cell adhesion of live and dead cells were monitored using novel fluorescent assays. Flow cytometry ...
Dyson Ossie F - - 2009
Kaposi's sarcoma-associated herpesvirus (KSHV) has both latent and lytic phases of replication. The molecular switch that triggers a reactivation is still unclear. Cells from the S phase of the cell cycle provide apt conditions for an active reactivation. In order to specifically delineate the Raman spectra of cells supporting KSHV ...
Thevenot Paul - - 2008
The success of tissue engineering scaffolds is intimately linked with the ability of the seeded cells to adequately distribute and proliferate within the scaffold matrix. In tissue engineering scaffolds, it is difficult to achieve adequate distribution due to the hydrophobic nature of most scaffold materials and poor initial distribution following ...
Manna U - - 2008
The effect of surfaces on the stability of smectic-C* (SmC*) variant phases is investigated. The results obtained using dielectric spectroscopy by varying the cell thickness show that the temperature ranges of SmCalpha*, SmCA*(1/2) , and SmCA*(1/3) phases decrease with decreasing cell thickness, and the SmCA*(1/3) phase is more stable than ...
Padfield Dirk - - 2009
Enabled by novel molecular markers, fluorescence microscopy enables the monitoring of multiple cellular functions using live cell assays. Automated image analysis is necessary to monitor such model systems in a high-throughput and high-content environment. Here, we demonstrate the ability to simultaneously track cell cycle phase and cell motion at the ...
Singh Parul - - 2008
In this study, the genotoxicity of commonly used insecticide cypermethrin and fungicide carbendazim were examined on root meristem cells of Hordeum vulgare L. Cypermethrin and carbendazim were applied with concentrations of 0.05%, 0.1% and 0.5% at different presoaking durations of 7 h, 17 h and 27 h which falls into ...
Umeyama Takashi - - 2008
Trypanosoma brucei, the etiologic agent of African sleeping sickness, divides into insect (procyclic) and bloodstream forms. These two forms are subject to distinct cell cycle regulations, with cytokinesis controlled primarily by basal body/kinetoplast segregation in the procyclic form but by mitosis in the bloodstream form. Polo-like kinases (PLKs), known to ...
Khammanit R - - 2008
The cell cycle stage of donor cells and the method of cell cycle synchronization are important factors influencing the success of somatic cell nuclear transfer. In this study, we examined the effects of serum starvation, culture to confluence, and treatment with chemical inhibitors (roscovitine, aphidicolin, and colchicine) on cell cycle ...
Li Kang - - 2008
Automated visual-tracking of cell populations in vitro using time-lapse phase contrast microscopy enables quantitative, systematic, and high-throughput measurements of cell behaviors. These measurements include the spatiotemporal quantification of cell migration, mitosis, apoptosis, and the reconstruction of cell lineages. The combination of low signal-to-noise ratio of phase contrast microscopy images, high ...
Zielke Norman - - 2008
Endoreplicating cells undergo multiple rounds of DNA replication leading to polyploidy or polyteny. Oscillation of Cyclin E (CycE)-dependent kinase activity is the main driving force in Drosophila endocycles. High levels of CycE-Cdk2 activity trigger S phase, while down-regulation of CycE-Cdk2 activity is crucial to allow licensing of replication origins. In ...
Morris D J - - 2008
Tetracapsuloides bryosalmonae is the myxozoan that causes the commercially and ecologically important proliferative kidney disease of salmonid fish species. Immunohistochemistry and electron microscopy were used to examine the development of this parasite within the kidney of the brown trout Salmo trutta. The main replicative phase of T. bryosalmonae is a ...
Raberg Matthias - - 2008
Two-dimensional polyacrylamide gel electrophoresis (2D PAGE), in combination with matrix-assisted laser desorption ionization-time of flight analysis, and the recently revealed genome sequence of Ralstonia eutropha H16 were employed to detect and identify proteins that are differentially expressed during different phases of poly(3-hydroxybutyric acid) (PHB) metabolism. For this, a modified protein ...
Kan Qiuming - - 2008
When cells traversing G(1) are irradiated with UV light, two parallel damage checkpoint pathways are activated: Chk1-Cdc25A and p53-p21(WAF1/CIP1), both targeting Cdk2, but the latter inducing a long lasting arrest. In similarly treated S phase-progressing cells, however, only the Cdc25A-dependent checkpoint is active. We have recently found that the p21-dependent ...
Yoon Jong Hyun - - 2008
Controlling the light energy and major nutrients is important for high cell density culture of cyanobacterial cells. The growth phase of Anabaena variabilis can be divided into an exponential growth phase and a deceleration phase. In this study, the cell growth in the deceleration phase showed a linear growth pattern. ...
Chong Sun Li - - 2008
The effect of mild hypothermic (32 degrees C) conditions on cell growth, cell-cycle progress, and antibody production of hybridoma C2E7 cells was investigated in the present study. The growth of hybridoma cells was slower during the mild hypothermic condition compared to that at 37 degrees C; this led to about ...
Balboa María A - - 2008
We have investigated the possible involvement of two intracellular phospholipases A(2), namely group VIA calcium-independent phospholipase A(2) (iPLA(2)-VIA) and group IVA cytosolic phospholipase A(2) (cPLA(2)alpha), in the regulation of human promonocytic U937 cell proliferation. Inhibition of iPLA(2)-VIA activity by either pharmacological inhibitors such as bromoenol lactone or methyl arachidonyl fluorophosphonate ...
Pin Carmen - - 2008
After inoculation, the times to the first divisions are longer and more widely distributed for those Escherichia coli single cells that spent more time in the stationary phase prior to inoculation. The second generation times are still longer than the typical generation times in the exponential phase, and this extended ...
Narisara Suksamai
Thesis (M.Eng.)--Chulalongkorn University, 2000
Aragon Anthony D - - 2008
Cells in glucose-limited Saccharomyces cerevisiae cultures differentiate into quiescent (Q) and nonquiescent (NQ) fractions before entering stationary phase. To understand this differentiation, Q and NQ cells from 101 deletion-mutant strains were tested for viability and reproductive capacity. Eleven mutants that affected one or both phenotypes in Q or NQ fractions ...
Poon, Grace, Chemical Sciences ...
The Vanadium bromide (V/Br) flow cell employs the Br3-/Br- couple in the positive and the V(II)/V(III) couple in the negative half cell. One major issue of this flow cell is bromine gas formation in the positive half cell during charging which results from the low solubility of bromine in aqueous ...
Remaud Sylvie - - 2008
We have studied cell sensitivity to Notch pathway signalling throughout the cell cycle. As model system, we used the Drosophila bristle lineage where at each division N plays a crucial role in fate determination. Using in vivo imaging, we followed this lineage and activated the N-pathway at different moments of ...
Kwiatkowska Dorota - - 2008
The shoot apical meristem generates stem, leaves, and lateral shoot meristems during the entire shoot ontogeny. Vegetative leaves are generated by the meristem in the vegetative developmental phase, while in the reproductive phase either bracts subtending lateral flower primordia (or paraclades), or perianth and strictly reproductive organs are formed. Meristem ...
Mimura Haruo - - 2008
The isolate, Pesudoalteromonas sp. TBT1, could grow to overcome the toxicity of tributyltin chloride (TBTCl) up to 30 microM in the absence of Cl(-) in the medium until the cells reached an exponential phase of growth. The viability, however, was reduced after the cells reached a stationary phase. The degradation ...
Zhang Shengliang - - 2008
Naf1alpha is an HIV Nef-associated factor expressed ubiquitously in human cells. Previously, we reported that Naf1alpha is phosphorylated with EGF through MEK/ERK2 pathway. In this study, we found an additional phosphorylation of Naf1alpha when cells are in mitotic phase (M phase) or arrested in M phase with anti-mitosis reagents, and ...
Khot Prasanna D - - 2008
Metabolic assays are a preferred method for evaluation of Candida albicans viability after exposure to antimicrobial agents in cases in which the culture is a complex mixture of yeast and filamentous forms. There is a lack of published data indicating the strength of the correlation between metabolic assays and viable ...
Kim Unyoung - - 2007
An effective, noninvasive means of selecting cells based on their phase within the cell cycle is an important capability for biological research. Current methods of producing synchronous cell populations, however, tend to disrupt the natural physiology of the cell or suffer from low synchronization yields. In this work, we report ...
Thullberg Minna - - 2007
Cell anchorage is required for cell proliferation of untransformed cells, whereas anchorage-independent growth can be induced by oncogenes and is a hallmark of transformation. Whereas anchorage-dependent control of the progression of the G(1) phase of the cell cycle has been extensively studied, it is less clear whether and how anchorage ...
Sasaki Yutaka - - 2008
To understand complex responses of plant cells to low temperatures, suspension-cultured cells of Arabidopsis thaliana (line T87) were characterized during cold treatment. Freezing tolerance of cells collected at the lag or log phase was quite different: an increase in freezing tolerance during cold treatment was only detectable with cells at ...
Kan Qiuming - - 2007
When cells progressing in G(1) phase are irradiated with UV light, two damage checkpoint pathways are activated: CHK1-Cdc25A and p53-p21WAF1/CIP1, both targeting Cdk2 but the latter inducing long lasting inactivation. In similarly irradiated S phase cells, however, p21WAF1/CIP1-dependent checkpoint is largely inactive. We report here that p21-dependent checkpoint can effectively ...
Dutuit Pierre - - 2007
Salicylhydroxamic acid (SHAM) inhibits the proliferation of cultured plant (Atriplex halimus) and murine neuroblastoma cells with IC50 of 90 and 250 microM, respectively. After 2 h of application, SHAM induces an acceleration of the neuroblastoma cell cycle from G1/S to G2 phases and, after 6 h, it induces an accumulation ...
Wang Meng - - 2008
Automated identification of cell cycle phases captured via fluorescent microscopy is very important for understanding cell cycle and for drug discovery. In this article, we propose a novel cell detection method that utilizes both the intensity and shape information of the cell for better segmentation quality. In contrast to conventional ...
Pagès Delphine - - 2007
Pseudomonas brassicacearum forms phenotypic variants in vitro as well as in planta during root colonization under natural conditions, leading to subpopulations (phase I and II cells) that differ in colony morphology and production of exoenzymes/secondary metabolites. The maximal concentration of cadmium allowing both variants growth was 25 muM; however, phase ...
Buckstein Michael H - - 2008
Using a modified method that involves minimal manipulation of cells, we report new information about nucleotide pool sizes and changes throughout the Escherichia coli growth curve. Nucleotide pool sizes are critically dependent on sample manipulation and extraction methods. Centrifugation and even short (2 min) lapses in sample preparation can dramatically ...
Wakasugi Mitsuo - - 2007
DDB1 was originally identified as a heterodimeric complex with DDB2 and plays an accessory role in nucleotide excision repair. DDB1 also constitutes an E3 ubiquitin ligase complex together with Cul4A and Roc1 and acts as an adaptor, suggesting its multiple roles beyond DNA repair. We have generated a conditional DDB1-knockout ...
Zhang Rui L - - 2008
The proportion of neural progenitors that remain in (P fraction) and exit from (Q fraction) the cell cycle determines the degree of neurogenesis. Using S-phase labeling with 5-bromo-2'-deoxyuridine and a double nucleoside analog-labeling scheme, we measured the cell-cycle kinetics of neural progenitors and estimated the proportion of P and Q ...
Ullner Ekkehard - - 2007
We show that phase-repulsive coupling eliminates oscillations in a population of synthetic genetic clocks. For this, we propose an experimentally feasible synthetic genetic network that contains phase repulsively coupled repressilators with broken temporal symmetry. As the coupling strength increases, silencing of oscillations is found to occur via the appearance of ...
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