Exposure of cells to ionizing radiation causes phosphorylation of histone H2AX at sites flanking DNA double-strand breaks. Detection of phosphorylated H2AX (gammaH2AX) by antibody binding has been used as a method to identify double-strand breaks. Although generally performed by observing microscopic foci within cells, flow cytometry offers the advantage of ...

It has been described that the replication regulator protein geminin is rapidly degraded at the end of mitosis and newly expressed at the beginning of the next S phase in the metazoan cell cycle. We have performed experiments to investigate the synthesis of geminin in cycling human HeLa cells. The ...

DnaA protein activity, the initiator of chromosomal DNA replication in bacteria, is regulated by acidic phospholipids such as phosphatidylglycerol (PG) or cardiolipin (CL) via facilitation of the exchange reaction of bound adenine nucleotide. Total lipid isolated from exponentially growing Staphylococcus aureus cells facilitated the release of ATP bound to S. ...

Nelarabine, prodrug of arabinosylguanine (ara-G), has demonstrated T-lymphoblastic antileukemic activity in cell lines and in the clinic. To investigate the mechanism for lineage-specific toxicity, the effects of ara-G were compared in CEM (T-lymphoblast), Raji (B-lymphoblast), and ML-1 (myeloid) cell lines. CEM cells were the most sensitive to ara-G-induced apoptosis and ...

The hypothesis that intracellular oxidation/reduction (redox) reactions regulate the G(0)-G(1) to S-phase transition in the mouse embryonic fibroblast cell cycle was investigated. Intracellular redox state was modulated with a thiol-antioxidant, N-acetyl-L-cysteine (NAC), and cell cycle progression was measured using BrdUrd pulse-chase and flow cytometric analysis. Treatment with NAC for 12 ...

An intriguing mutant was isolated in Schizosaccharomyces pombe, which is defective in the maintenance of viability after entry into the stationary phase. In the logarithmic growth phase, the mutant cells grow at the same rate as the parental cells. Upon the onset of the stationary phase, however, the mutant cells ...

Micro-organisms used during the production of fermented foods are subjected to several abiotic stresses. Microbial survival during these processes strongly depends on the ability of the cells to adapt and become more tolerant to the environmental conditions. Cultivation of Lactobacillus amylovorus DCE 471, a potential strain for use during type ...

Previously, we showed that the peak density of the transient outward K(+) current (I(to)) expressed in GH3 cells was different in the S phase than in other phases of the cell cycle. Using cell synchronization, we show here that I(to) drops precisely at the quiescent (G(0) phase)/proliferating transition. This change ...

We analyzed the composition and abundance of two forms of RNA polymerase II (pol II) holoenzyme in synchronized HeLa cells. We did not detect significant changes in pol II holoenzyme composition, but we noticed differences in the abundance of the two complexes at different stages of the cell cycle. Summarized ...

When a brief current pulse is incident on excitable cells in cardiac and other nervous tissue, a change in phase of the cell's response is usually observed. In cardiac tissue, the cells are exposed to external stimulation of mainly positive currents, which depolarize the cells. We performed a systematic study ...

Protein kinase CK2 is a ubiquitous protein serine/threonine kinase that is involved in cell growth and proliferation as well as suppression of apoptosis. Several studies have suggested that the kinase plays a role in cell cycle progression; however, changes in enzyme activity during phases of cell cycle have not been ...

Nitric oxide (NO) is an important messenger molecule with multiple biological activities. In the present study, sper/NO, a NO generator, showed a biphasic effect on the proliferation of human salivary gland neoplastic (HSG) cells. Sper/NO of less than 20 micro M stimulated cells to depart from the G2/M phase and ...

The frequency of labeled mitoses (FLM) method for analyzing cell-cycle phases necessitates a determination of cell-cycle interdivision times and the absolute lengths of the cell-cycle phases. The change to flow sorting (FACS) analysis, a simpler, less labor intensive, and more rapid method, eliminated determinations of absolute phase times, yielding only ...

Yeast cells (Sacchromyces cerevisiae) in 0.9% NaCl solution containing phloxine B (dye) were treated by an application of a rectangular electric pulse. We input microscopic images of the yeast suspensions after the application into a computer, and measured whether each cell dyes or not, the phase in the cell cycle, ...

Modulation of ion permeability during the cell cycle is one of the key events in cell cycle progression. We have compared the effects of K+ and Cl- channel blockers on the cell cycle in synchronous and asynchronous NIH3T3 cells. The Cl- channel blocker 5-N-2-(3-phenylpropylamino) benzoic acid (NPPB; 0.2 mM) inhibited ...

c-myc is an important protooncogene whose misregulation is believed to causally affect the development of numerous human cancers. c-myc null rat fibroblasts are viable but display a severe (two- to threefold) retardation of proliferation. The rates of RNA and protein synthesis are reduced by approximately the same factor, whereas cell ...

Stationary-phase cells displayed a distribution of relaxed plasmids and had the ability to recover plasmid supercoiling as soon as nutrients became available. Preexisting gyrase molecules in these cells were responsible for this recovery. Stationary-phase rpoS cells showed a bimodal distribution of plasmids and failed to supercoil plasmids after the addition ...

"June 2003".

GaSb thermophotovoltaic (TPV) cells are one of the reasons for the renewed interest in TPV technology. Today, they are the most suitable choice for modem TPV generators. This paper reviews the background and the status of the GaSb photovoltaic cell development. GaSb TPV cells are fabricated either by a zinc ...

Cytosolic phospholipase A2 (cPLA2) cleaves fatty acids from the sn-2 position of phospholipids resulting in the release of arachidonic acid. cPLA2 is activated upon phosphorylation, followed by a Ca(2+)-dependent translocation to cellular membranes. The activity of cPLA2 has been demonstrated to fluctuate during the M, G1 and S-phases of the ...

A quantitative competitive PCR (QC-PCR) assay targeting the phlA gene of Pseudomonas fluorescens CHA0 was developed and tested in vitro. Statistically significant, positive correlations were found between QC-PCR and both CFU and total cell number when studying cells in log or stationary phase. The correlations disappeared when considering stressed cells.

This is the first report describing the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), as a protein associated with the cell envelope of a gram-negative bacterium (Aeromonas hydrophila). Dose-dependent GAPDH activity was detected in whole bacterial cells from exponentially growing cultures, indicating that an active form of GAPDH is located outside the ...

AIMS: The aim of this work was to study the effects of prolonged nutrient stress on survival, cell interactions and resistance to inimical processes in Salmonella serotype Typhimurium. METHODS AND RESULTS: Salmonella Typhimurium cells were subjected to prolonged incubation in the stationary phase of growth and the properties of starved ...

Cells must exert force against the substrate to migrate. We examined the vectors (both the direction and the magnitude) of the traction force generated by Dictyostelium cells using an improved non-wrinkling silicone substrate. During migration, the cells showed two 'alternate' phases of locomotory behavior, an extension phase and a retraction ...

PURPOSE: Proliferative epithelial metaplasia that develops in the anastomotic line after gastrocystoplasty has unknown malignant potential. Flow cytometry analysis of cell cycle profiles is used to predict the neoplastic progression of metaplastic lesions in other proliferative epithelium. We used this technique to evaluate transitional cell metaplasia in rat gastrocystoplasty specimens. ...

The relationship between apoptotic progression and cell cycle perturbation induced by microtubule-destabilising (vinblastine, Colcemid) and -stabilising (taxol) drugs was studied in two mesenchyme-derived neoplastic cell lines, growing as suspension (Jurkat) and monolayer (SGS/3A) culture, by morphocytochemical and biochemical approaches. The same kind of drug induced different effects on the cell ...

To estimate the physiological roles of a germin-like protein (BuGLP) with Mn-SOD activity isolated newly from a moss, Barbula unguiculata, BuGLP mRNA levels during cell growth and the effects of methyl viologen and salt stress were studied. BuGLP mRNA levels were at their peak during the exponential phase of growth ...

Eukaryotic cell proliferation is controlled by specific growth factors and the availability of essential nutrients. If either of these signals is lacking, cells may enter into a specialized nondividing resting state, known as stationary phase or G(0). The entry into such resting states is typically accompanied by a dramatic decrease ...

The streptococcal cell wall model of arthritis in Lewis rats consists of an acute, non-T-cell-dependent initiation phase, followed by a remission and then a chronic, inflammatory T-cell-dependent phase. In this report, we define pertinent changes in the cognate and noncognate immune system of the Lewis rats during various phases of ...

The incorporation of [(14)C]-linoleic acid (LA) into total lipid fractions was higher in LLC-WRC256 cells from the log phase of growth as compared to those of the plateau phase. LA was mainly incorporated into the phospholipid (PL) fraction of cells during the log phase, whereas in the plateau phase it ...

Transcriptional silencing in Saccharomyces cerevisiae involves the assembly of a heterochromatic domain that is heritable from generation to generation. To maintain the silenced state, the propagation of silent heterochromatin must be coordinated with the events of chromosome duplication and segregation. Here we present an in vivo analysis of the cell-cycle ...

The adult suprachiasmatic nucleus (SCN) expresses a polysialylated form of neural cell adhesion molecule (PSA-NCAM) that modulates cell interactions. Previous studies have shown that PSA is important for photic entrainment of the SCN circadian clock, suggesting that changes in cell-cell interactions may contribute to the phase-resetting capacity of this system. ...

The migration of haemopoietic stem and progenitor cells across endothelium lining bone marrow sinuses is a critical first step in the homing and successful engraftment of these cells. We have previously shown that freshly isolated mobilized peripheral blood CD34+ cells adhere to the endothelial surface but do not transmigrate unless ...

This study investigated the interaction between microbial growth and cell elution, and their influence on resultant microbial distribution between the aqueous and solid phases during solute transport in a sandy, low-organic-carbon-content porous medium. Miscible displacement experiments were conducted with salicylate as the model compound, and with different initial conditions (e.g., ...

The microbiological isomerization of linoleic acid (LA) to conjugated linoleic acid (CLA) was studied in resting cell suspensions of a propionibacterium and micellar LA to identify factors critical in the isomerization efficiency. These suspensions, containing cells 5x10(10) colony-forming units ml(-1) and 510 micro g LA ml(-1), isomerized about 90% of ...

AIMS: To ascertain whether the expression and enzyme activity of thymidylate synthase (TS) are related to the rapidity of cell proliferation in human cancer cell lines. METHODS: Ten asynchronously growing human cancer cell lines of different origin were used, characterised by various doubling times. TS expression was evaluated by western ...

Arterial remodeling in response to pathological insult is a complex process that depends in part on the balance between vascular cell apoptosis and proliferation. Studies in experimental models suggest that HO-1 mediates neointimal formation while limiting lumen stenosing, indicating a differential effect on vascular endothelial (EC) and smooth muscle cells ...

Computer simulation has been carried out to help to determine the cell-proliferative mechanisms underlying data gathered from a double-labelling experiment on the dorsal tongue of the mouse. Good fits to the data have been obtained by assuming that there is a high degree of synchrony in the stem cells, which ...

We examined the mechanism of action of nitrosoureas as represented by 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) with respect to p53 and the G2M cell cycle checkpoint using two glioblastoma cell lines: U251MG and U373MG, with mutated p53. At log-phase cell growth, fresh medium containing ACNU (final concentration, 3, 10, or 30 microg/ml) ...

Cerebellar granule cells exhibit distinct modes of migration in different cortical layers. The role of external cues in controlling these alterations has been suggested, but the significance of internal programs is not well understood. In the present study, we examined autonomous changes of migratory behavior of isolated granule cells in ...

The SIN3 corepressor and RPD3 histone deacetylase are components of the evolutionarily conserved SIN3/RPD3 transcriptional repression complex. Here we show that the SIN3/RPD3 complex and the corepressor SMRTER are required for Drosophila G(2) phase cell cycle progression. Loss of the SIN3, but not the p55, SAP18, or SAP30, component of ...

OBJECTIVE: To investigate the effects of sulindac metabolites on proliferation and apoptosis in the human umbilical vein endothelial cell line ECV304 in vitro. METHODS: The proliferation profile of ECV304 was determined by methyl thiazolyl tetrazolium (MTT) method. Cell cycle distribution, apoptosis and the ultrastructure of ECV304 were detected by flow ...

During prolonged incubation in stationary phase Escherichia coli undergoes starvation-induced differentiation, resulting in highly resistant cells. In rich medium with high amino acid content further incubation of cultures at high cell density leads to the generation of a population of cells no longer able to form colonies. The viability loss ...

We have previously shown that ATRA potentiates CDDP cytotoxicity in various ovarian carcinoma cell lines. In the present study, we found that the enhanced sensitivity to CDDP was due to an increase of CDDP-induced apoptosis in OVCCR1 and NIH-OVCAR-3 cells. In these cell lines, flow cytometric analysis indicated that CDDP ...

The firing of hippocampal principal cells in freely running rats exhibits a progressive phase retardation as the animal passes through a cell's "place" field. This "phase precession" is more complex than a simple linear shift of phase with position. In the present paper, phase precession is quantitatively analyzed by fitting ...

Human glioblastoma cell line T98G produced a cellular form of prion protein (PrP(C)), and we confirmed expression of PrP mRNA by RT-PCR. Immunoblot analysis of whole cell lysate revealed one major (35 kDa) and two faint bands (31, 25 kDa) that reacted with monoclonal anti-human PrP antibody 3F4. Cells treated ...

nPKC delta is a phospholipid-dependent and calcium-independent PKC isoform, whose over expression in BL6T murine melanoma cells, modifies their proliferative and metastatic potential in vivo. We focus here on the possible relationship between the subcellular localisation of nPKC delta and distinct phase of the cell cycle. Our findings show a ...

Expression of luteinizing hormone-releasing hormone (LHRH) and its receptor as part of an autocrine regulatory system of cell proliferation has been demonstrated in a number of human malignant tumors, including cancers of the ovary. This study was conducted to investigate whether LHRH induces activation of JunD and affects cell cycle ...

The development of cabbage petals comprises two distinct phases: a cell division phase and a consecutive phase of cell expansion until the onset of opening. In this study, cytological changes characterizing the two phases of petal development were analysed. First, the mitotic activity and the surface area of epidermal cells ...

AIM: To study the viscoelastic properties of human hepatocytes and hepatocellular carcinoma (HCC) cells under cytoskeletal perturbation, and to further to study the viscoelastic properties and the adhesive properties of mouse hepatoma cells (HTC) in different cell cycle. METHODS: Micropipette aspiration technique was adopted to measure viscoelastic coefficients and adhesion ...