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, ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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. ...

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 ...

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 ...

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 ...

Thesis (M.Eng.)--Chulalongkorn University, 2000

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

To investigate the contributions of phosphatidylserine to the growth and morphogenesis of the rod-shaped fission yeast Schizosaccharomyces pombe, we have characterized the single gene in this organism, pps1, encoding a predicted phosphatidylserine synthase. S. pombe pps1Delta mutants grow slowly in rich medium and are inviable in synthetic minimal medium. They ...

We used intrachromosomal substrates to directly monitor the effect of the cell cycle on the efficiency and the accuracy of nonhomologous end joining (NHEJ) in mammalian cells. We show that both KU and KU-independent (KU-alt) pathways are efficient when maintaining cells in G1/S, in G2/M or during dynamic progression through ...

In Pseudomonas aeruginosa, azithromycin has been shown to reduce virulence factor production, to retard biofilm formation, and to exhibit bactericidal effects on stationary-phase cells. In this study we analyzed whether these azithromycin-mediated effects require interaction with the ribosome. We blocked the access of azithromycin to the ribosome in P. aeruginosa ...

In vitro studies with the organic extracts of diesel particles have suggested that hydrocarbons such as PAH may play a role in an inflammatory response, but these have been limited by the possible artifacts introduced in the particle collection and processing. In this study, we avoid these artifacts and use ...

Noninvasive measurement of 3-D morphology of adhered animal cells employing a phase-shifting laser microscope (PLM) is investigated, in which the phase shift for each pixel in the view field caused by cell height and the difference in refractive indices between the cells and the medium is determined. By employing saline ...

Cell cycle progression through G1 phase is of particular importance because this is the phase where the decision to embark on another cell cycle is made. An aberrant G1/S transition often leads to cell cycle deregulation and cancer development. Therefore, there is a complex regulatory network to ensure timely entry ...

Proteolytic processing at the end of the G(1) phase generates a CUX1 isoform, p110, which functions either as a transcriptional activator or repressor and can accelerate entry into S phase. Here we describe a second proteolytic event that generates an isoform lacking two active repression domains in the COOH terminus. ...

BACH1 (also known as FANCJ and BRIP1) is a DNA helicase that directly interacts with the C-terminal BRCT repeat of the breast cancer susceptibility protein BRCA1. Previous biochemical and functional analyses have suggested a role for the BACH1 homolog in Caenorhabditis elegans during DNA replication. Here, we report the association ...

Cells of Rhodococcus erythropolis DCL14 were adapted to increasing toluene concentrations in a mechanically stirred reactor. When the initial non-adapted cells were placed in contact with toluene, only 10.5% of cells remained viable after 1 h in the presence of 20% (v/v) toluene, while 8.6% of cells were viable after ...

In response to DNA damage, cells activate a complex protein network designed to sustain genomic integrity. Many of the proteins involved in the network form discrete repair foci, the composition of which is determined by the specific type of damage. Replication protein A (RPA) and the Mre11/Rad50/Nbs1 (MRN) complex both ...

We report NMR measurements of metallic (133)Cs in glass cells. The solid-liquid phase transition was studied by observing the NMR peaks arising from these two phases; surprisingly, many cells yielded two additional NMR peaks below the melting point. We attribute these signals to two distinct impurities which can dissolve in ...

To examine the changes in physiological activity and radiosensitivity of cultured cells during a culture period, the long‐term subcultured callus cells of the rice viriety "Sensho" which refer to as SC‐cell line were used as experimental materials. The SC‐cell was characterized by considerably homogeneous diploid cell population and by sigmoidal ...

In this paper we investigate the propagation behavior of a square shaped planar meta-material guiding structure comprised of lefthanded and righted handed square unit cells each of the same size and arranged in a checker-board tessellation. The size of the planar structure is 19 cells by 19 cells and each ...