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Results 651 - 700 of 1719
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Thömmes J - - 2001
The purification of human chymotrypsinogen B (hCTRB) after expression and secretion by the yeast Pichia pastoris is described based on two different approaches using integrated initial recovery. Extraction employing aqueous two-phase systems (ATPS) from poly(ethylene glycol) and sodium sulfate allows direct processing of cell containing yeast suspensions of 50% wet ...
Fontijn R D - - 2001
Several members of the kinesin superfamily are known to play a prominent role in the motor-driven transport processes that occur in mitotic cells. Here we describe a new mitotic human kinesin-like protein, RB6K (Rabkinesin 6), distantly related to MKLP-1. Expression of RB6K is regulated during the cell cycle at both ...
Babudri N - - 2001
In order to understand the role of yeast polymerases in spontaneous mutagenesis in non-growing cells we have studied the effects of mutations that impair the 3'--> 5' exonuclease function of polymerases delta (pol3-01) and epsilon (pol2-4) on the spontaneous reversion frequency of the frameshift mutation his7-2 in cells starved for ...
Luppens S B - - 2001
The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter(-1)), a similar reduction in viable cell numbers was observed for stationary-phase cells and exponential-phase cells ...
Zhao J - - 2001
Cellular dedifferentiation is the major process underlying totipotency, regeneration, and formation of new stem cell lineages in multicellular organisms. In animals it is often associated with carcinogenesis. Here, we used tobacco protoplasts (plant cells devoid of cell wall) to study changes in chromatin structure in the course of dedifferentiation of ...
Meiyanto E - - 2001
Osteoclast differentiation factor (ODF) induces differentiation of mouse RAW264 cells to mature osteoclasts. To understand the mechanism controlling a coupling between withdrawal from the cell cycle and differentiation, we examined cell cycle progression and expression profiles of cell cycle regulatory genes at the initial phase in committed cells. ODF rapidly ...
Park J W - - 2001
Resveratrol, a natural product derived from grapes, has been shown to prevent carcinogenesis in murine models. We report here that resveratrol induces antiproliferation and arrests the S phase in human histiocytic lymphoma U937 cells. Resveratrol induces arrest in the S phase at low concentrations (30-60 microM), but high concentrations do ...
Sun W - - 2001
PAL31 is a nuclear protein expressed by various cell types. In the present study, the expression and function of PAL31 were examined in the cytokine-regulated growth of T and B cell lines. Treatment of the cells with mitogens [ovine PRL, recombinant rat placental lactogen-I (PL-I) and human IL-3] caused a ...
Olsson, Thomas
A fully integrated digital phase-locked loop (PLL) used as a clock multiplying circuit is designed. The PLL is made from standard cells found in almost any commercial standard cell library and therefore portable between processes in netlist format. Using a 0.35 μm standard complementary metal-oxide-semiconductor CMOS process and a 3.0 ...
Zölzer F - - 2001
Similar to what has been observed after irradiation, the fraction of G(2)-phase cells increases as a consequence of heat treatment. On the basis of cell cycle distributions alone, however, it is difficult to say whether the two results are related. In particular, comparison is complicated by the fact that the ...
Matora L Y - - 2001
The structural influence of Azospirillum lipopolysaccharides (LPS) and lipopolysaccharide-protein complexes (LPPC) on carrot, erythrocyte, and bacterial cell suspensions was explored. The structural potentialities of O-specific polysaccharide fragments of LPS and protein fractions of LPPC were also evaluated. An ability to induce the formation of three kinds of structures in the ...
Shi Bin-Shan - - 2001
FEN-1 is essential in the cell replication, repair and in the maintenance of cellular genetic stability. In this report, it was verfied that FEN-1 antisense mRNA fragment was expressed in the cell line FL-FEN-1(-),constructed in our lab, blocking FEN-1 gene expression. It was found by the flow cytometer analysis that ...
Jeon S J - - 2001
The nucleoid structure and the partition in the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 were observed by a combination of phase-contrast microscopy and fluorescence microscopy. The nucleoids occurred as rounded fluorescent foci centrally located in the cells and as differences in fluorescence intensity between exponential and stationary phases. The cellular space ...
Kadavy D R - - 2000
Reactivation of UV-C-inactivated Pseudomonas aeruginosa bacteriophages D3C3, F116, G101, and UNL-1 was quantified in host cells infected during the exponential phase, during the stationary phase, and after starvation (1 day, 1 and 5 weeks) under conditions designed to detect dark repair and photoreactivation. Our experiments revealed that while the photoreactivation ...
Binder A B - - 2000
Irradiation of human melanoma (MeWo, Be11) and squamous cell carcinoma (4451, 4197) cells induces cell cycle blocks from which the cells recover to re-enter mitosis after 40-60 h. In the TP53 mutant cell lines, MeWo and 4451, irradiation induces a G(2)-phase block, where the fraction of cells in G(2) phase ...
Dutta C - - 2000
We have observed previously that attachment of Toxoplasma gondii to synchronized host cells is considerably increased at the mid-S phase (4 h postrelease). Synchronized CHO host cells at the mid-S phase were fractionated by molecular weight, and the antigens were used to produce a panel of polyclonal mouse antisera. The ...
Li Q S - - 2000
Peripheral negative selection of cycling T cells after TCR engagement and deletion of activated T cells after an immune response occur by an apoptotic process termed activation-induced cell death (AICD). The cross-linking of TCR-CD3 complex with anti-CD3 monoclonal antibody led to significant apoptotic cell death in peripheral blood T cells. ...
Asami K - - 2000
A dielectric method has already been developed for the real-time monitoring of cell cycle progression in synchronized cell culture (Asami et al., 1999). This method, in combination with DNA content analysis by fluorescence-activated cell sorting (FACS), was applied to the synchronized cell culture of a CDC28-13th mutant (Saccharomyces cerevisiae). In ...
Zagon I S - - 2000
The native opioid growth factor (OGF), [Met5]-enkephalin, is a tonic inhibitory peptide that modulates cell proliferation and migration, as well as tissue organization, during development, cancer, homeostatic cellular renewal, wound healing, and angiogenesis. OGF action is mediated by the OGF receptor (OGFr). To investigate the target of OGF as to ...
Rosti V - - 2000
BACKGROUND AND OBJECTIVES: In the recent years many studies on the expansion of cord blood (CB)-derived progenitor cells have been performed, whereas less information is available on their cycling status. The objective of this study was to evaluate the cycling status of CB-derived colony-forming cells (CFC) and long-term culture-initiating cells ...
Sänger N - - 2000
The aim of this study was to measure the expression of peripheral benzodiazepine receptors (PBR) as well as mitochondria content in different phases of the cell cycle of BT-20 and MCF-7 breast cancer cell lines, using two-parameter flow cytometric analyses. The PBR expression as well as mitochondria mass, were found ...
Kálnay A - - 2000
The effect of various GnRH analogues, and their conjugates on proliferation, clonogenicity and cell cycle phase distribution of MCF-7 and Ishikawa human cancer cell lines was studied. GnRH-III, a sea lamprey GnRH analogue reduced cell proliferation by 35% and clonogenicity by 55%. Structural modifications either decreased, or did not alter ...
Sinha J - - 2000
Extractive fermentation in aqueous two-phase systems is a meaningful approach to overcome low product yield in a conventional fermentation process, and by proper design of the two-phase system it is possible to obtain the product in a cell-free stream. The characteristics of an aqueous two-phase system, various polymers used for ...
Ericsson M - - 2000
We have developed a method, using laser, optical tweezers and direct microscopic analysis of reproductive potential and membrane integrity, to assess single-cell viability in a stationary-phase Escherichia coli population. It is demonstrated here that a reduction in cell integrity, determined by using the fluorescent nucleic acid stain propidium iodide, correlated ...
Canning E U - - 2000
Tetracapsula bryosalmonae, formerly PKX organism, is a myxozoan parasite that causes proliferative kidney disease in salmonid fish. Its primary hosts, in which it undergoes a sexual phase, are phylactolaemate bryozoans. It develops in the bryozoan coelomic cavity as freely floating sacs which contain two types of cells, stellate cells and ...
Dieterich P - - 2000
To evaluate shear stress-induced effects on cultured cells we have extended the mechanical setup of a multichannel in vitro rheological system and developed software allowing entire processing control and image data analysis. The values of cell motility, degree of orientation (alignment), and cell elongation were correlated as a function of ...
Sugimoto K - - 2000
In yeast cells, the intra-S-phase checkpoint slows down the rate of DNA replication in response to DNA damage. Here we showed that a similar checkpoint mechanism is present and activated by anti-tumour drugs in HL-60 and Epstein-Barr virus (EBV)-transformed human lymphoblastoid cells. Using bromodeoxyuridine (BrdU) pulse labelling combined with two-dimensional ...
Mediavilla M D - - 2000
The objective of the present work was to study the effects of 3'-azido-3'-deoxythymidine (azidothymidine, Zidovudine) on human breast cancer cells by using, as a model, the T47D cell line (typified as oestrogen-dependent and p53-mutated). Low azidothymidine doses (3.125 microM) increase the percentage of cells in S-phase, with the effect reversing ...
Doverskog M - - 2000
Cell cycle progression was studied in serum-free batch cultures of Spodoptera frugiperda (Sf9) insect cells, and the implications for proliferation and productivity were investigated. Cell cycle dynamics in KBM10 serum-free medium was characterized by an accumulation of 50-70% of the cells in the G(2)/M phase of the cell cycle during ...
Kondo T - - 2000
An immunohistochemical study on the temporal expression of c-Fos and c-Jun, both of which designate proto-oncogene products, was performed on 60 human skin wounds with different post-infliction intervals. In unwounded skin, c-Fos or c-Jun was immunolocalized at the nuclei of the epidermal cells in the basal layer, hair follicle cells ...
Grasl-Kraupp B - - 2000
The formation and development of initiated cells has been studied at the beginning of hepatocarcinogenesis. Rats received the genotoxic carcinogen N-nitrosomorpholine (NNM); placental glutathione S-transferase was used as a marker of initiated cells (G+ cells). Single G+ cells appeared within 24 h after NNM; their frequency increased steeply for approximately ...
Li X - - 2000
OBJECTIVE: To access the production of a novel uterine luminal fluid 250 kD protein (ULF-250) during the various phases of the estrous cycle in relation to estrogen concentration, and to validate that the production and secretion of ULF-250 are regulated by estradiol and progesterone. METHODS: An immunohistochemical method was used ...
Kanouchi H - - 2000
To clarify the biological role of kidney perchloric acid-soluble protein 1 (K-PSP1), its expression and intracellular distribution were examined in normal rat kidney epithelial NRK-52E cells. K-PSP1 expression was low during the proliferating phase and high in the stationary phase, and shown to have a negative relationship with the protein-synthesizing ...
Alm K - - 2000
When Chinese hamster ovary cells were seeded in the presence of the spermine analog N1,N11-diethylnorspermine (DENSPM), cell proliferation ceased; this was clearly apparent by cell counting 2 days after seeding the cells. However, 1 day after seeding there was a slight difference in cell number between control and DENSPM-treated cultures. ...
Jydegaard A M - - 2000
Bacteriocin inactivation of Listeria monocytogenes 412 was studied as a function of growth phase. Cells were treated with nisin (300 IU ml-1) or pediocin (320 or 2560 AU ml-1) for 20 min at 30 degrees C. Inactivation with nisin or the low concentration of pediocin was growth phase dependent, with ...
Kimura K - - 2000
We developed a new pull-down assay for GTP-Rho and examined its level during cell cycle. HeLa cells were arrested in the S phase by thymidine and were enriched in the prometaphase, metaphase, telophase, and G(1) phase by collecting at 0, 45, 90, and 180 min after the release from the ...
Erlebach C E - - 2000
The size distributions of an arthrobacter, approximately 1 microm in diameter, were analysed using a Coulter Multisizer II instrument thereby making it possible to distinguish between the different stages in the morphological cycle. The results indicated that at the beginning of exponential phase a shift occurred from large to smaller ...
Wang Q M - - 2000
p53/56(lyn) is a member of the src family that is predominantly expressed in hematopoietic cells and is thought to play a role in cellular proliferation. In this study, we demonstrate the participation of p53/56(lyn) in 1,25-dihydroxyvitamin D(3) (1, 25D(3))-induced growth arrest in HL60 cells. We show that the mRNA and ...
Higashijima Y - - 2000
SDH activity and its frequency distributions were determined cytophotometrically to investigate the change in respiratory oxidative energy metabolism in Paramecium caudatum (P. caudatum) cell populations during their growth in cell culture. Cells from 3 separate cultures were examined on day 2, 5 and 11 post-inoculation as measures of logarithmic, early ...
Mastbergen S C - - 2000
BACKGROUND: Regulators of cell cycle phase transitions could be important targets for cancer treatment using cytostatic chemotherapy. Therefore, the extent of cell cycle arrest induced by different cytostatic agents has to be correlated with ultimate clonogenic tumor cell death. Especially the value of early cell cycle perturbations as indicators for ...
Apostolova M D - - 2000
The transient nuclear localization of metallothionein during cell growth and differentiation may be related to the increased requirement of zinc for DNA synthesis, activation of metalloenzymes, and transcription factors. Treatment of 3T3-L1 fibroblasts with aphidicolin, an inhibitor of nuclear DNA synthesis, caused a cell-cycle block at G1/S phase and a ...
Jari Likonen,Jouko Haapamaa,Markus Pessa
The redistribution of Be during growth of GaInP layers by gas source molecular beam epitaxy has been studied using secondary ion mass spectrometry for the "rst time. Apparent Be di!usion occurs at doping level over 4#10## cm## at growth temperature of 5003C. At lower temperature the Be di!usion pro"le exhibits ...
Gupta S - - 2000
One thousand cervical smears from women who took part in a hospital-based screening programme for early detection of cervical cancer were studied for the presence of nuclear grooves. Grooved nuclei were frequently detected in intermediate cells in all phases of the menstrual cycle, although their frequency of occurrence was slightly ...
Hofer K G - - 2000
Chinese hamster ovary cells were synchronized at the G(1)/S-phase boundary of the cell cycle and were pulse-labeled with (125)I-iododeoxyuridine 30 min after they entered the S phase. Cell samples were harvested and frozen for accumulation of (125)I decays during the first and second G(2) phase after labeling. Cell aliquots that ...
Colter D C - - 2000
Cultures of plastic-adherent cells from bone marrow have attracted interest because of their ability to support growth of hematopoietic stem cells, their multipotentiality for differentiation, and their possible use for cell and gene therapy. Here we found that the cells grew most rapidly when they were initially plated at low ...
Christensen P U - - 2000
Two paradigms exist for maintaining order during cell-cycle progression: intrinsic controls, where passage through one part of the cell cycle directly affects the ability to execute another, and checkpoint controls, where external pathways impose order in response to aberrant structures. By studying the mitotic inhibitor Mik1, we have identified evidence ...
Lucotti C - - 2000
The objective of this study was to evaluate the cycling status of cord blood (CB)-derived colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC), and their recruitment into the S-phase of the cell cycle. By using the cytosine arabinoside (Ara-C) suicide approach, we found that only small proportions of both CFC ...
Zhu H - - 2000
The mutagenic heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-blpyridine (PhIP) is formed at parts per billion levels when meat is cooked. It is efficiently absorbed from cooked food and extensively activated to its genotoxic N-hydroxy derivative by human cytochrome P4501A enzymes. It is also a rodent carcinogen. To better understand the genetic toxicity of ...
Srikantha T - - 2000
The Candida albicans gene EFG1 encodes a putative trans-acting factor. In strain WO-1, which undergoes the white-opaque transition, EFG1 is transcribed as a 3.2-kb mRNA in white-phase cells and a less-abundant 2.2-kb mRNA in opaque-phase cells. cDNA sequencing and 5' rapid amplification of cDNA ends analysis demonstrate that the major ...
Thomas Fevens,Henk Meijer
We present an optimization algorithm to determine a partition of the convex hull of a finite set of ponts in the plane. The partition uses the points as corners of convex polygonal cells, each cell having at most K sides. We minimize the total number of cells that are obtained. ...
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