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Results 451 - 500 of 2272
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Walen Kirsten H - - 2002
Transformation of cells in culture is a model system for carcinogenesis, and two major theories (i.e., mutagenesis and aneuploidy) have emerged from in vitro and in vivo studies. A third view is presented here on the initial steps in the change of primary cells to extended life cells, and their ...
Huleihel Mahmoud - - 2002
Fourier transform infrared (FTIR) spectroscopy is a unique technique for the laboratory diagnosis of cellular variations based on the characteristic molecular vibrational spectra of the cells. Microscopic FTIR was used to investigate spectral differences between normal and malignant fibroblasts transformed by retrovirus infection. A detailed analysis showed significant differences between ...
Imani, J.
The percentage of cells successfully transformed by Agrobacteria is usually very low (not more than 10% and usually much less; Thomas et al., 1989). In this report we show that in carrot (Daucus carota L., ssp. sativus) cell suspensions transformation efficiency was strongly improved by using cell cycle synchronized cells. ...
Wang Xiaoping - - 2002
The biochemical mechanism of carbon tetrachloride transformation by poplar cells was investigated using an axenic poplar cell culture. After one-day incubations of poplar cells under aerobic conditions, about 1.5% of dosed carbon tetrachloride was transformed to carbon dioxide, about 0.001% to chloroform and about 3% of the carbon was bound ...
Plachý J - - 2002
Domestic chicken as a laboratory animal as well as chicken cells in vitro have been highly evaluated in several fields of experimental biology. Retrovirology and experimental oncology traditionally use this model, whose comparative aspects are still inspirative. The first (retro)viral aetiology of a tumour was recognized in the chicken and ...
Majsterek Ireneusz - - 2002
BCR/ABL oncogenic tyrosine kinase is responsible for the pathogenesis of Philadelphia chromosome-positive human leukemia and is generated by a specific reciprocal chromosome translocation, t(9;22)(q34-;q11+). We examined the role of DNA repair in therapeutic drug resistance to idarubicin in the murine pro-B lymphoid cell line BaF3 and its BCR/ABL -transformed clone. ...
Bauer G - - 2002
Transformed fibroblasts generate extracellular superoxide anions through the recently identified membrane-associated NADPH oxidase. These cell-derived superoxide anions exhibit signaling functions such as regulation of proliferation and maintenance of the transformed state. Their dismutation product hydrogen peroxide regulates the intracellular level of catalase, whose activity has been observed to be upregulated ...
Furalev V A - - 2002
Asbestos produced a cytotoxic effect on transformed cells of rat pleural mesothelium and on IAR2 epithelial cells and Rat1 fibroblasts transformed by ras oncogene, but not on normal cells of these strains under conditions of coculturing with peritoneal macrophages. Contact of mesothelioma cells, but not macrophages with asbestos was necessary ...
Fujiyama K - - 2001
Horseradish peroxidase isozyme C (HRP; EC 1.11.1.7) was used as a model protein to evaluate the capacity of tobacco cells transformed with human beta 1,4-galactosyltransferase (GT6) to modify and galactosylate a foreign glycoprotein. Cells transformed with the HRP gene are designated as BY2-HRP and GT6-HRP, for wild type BY2 and ...
Pfeifer T A - - 2001
A modified Factor X protein was combined with a cellulose-binding domain tag and expressed in insect cell lines. The protein, CBDFX, was expressed and secreted into the medium. Stable, transformed Hi5 and Sf9 insect cell lines were generated and tested for production of secreted CBDFX. The highest Sf9 and Hi5 ...
Mezzogiorno A - - 2001
Tissue transglutaminase (tTGase, tTG) is known as being implicated in the intracellular cross-linking of proteins occurring in a growing series of physiological conditions including--just to mention the most relevant ones--programmed cell death (apoptosis), cell adhesion, growth, spreading and differentiation, tumor growth, metastasis, cell adhesion, proliferation, differentiation, extra cellular matrix (ECM) ...
Palmarini M - - 2001
Jaagsiekte sheep retrovirus (JSRV) is the causative agent of a transmissible lung cancer of sheep known as ovine pulmonary carcinoma. Recently, we have found that the expression of the JSRV envelope (Env) is sufficient to transform mouse NIH 3T3 cells in classical transformation assays. To further investigate the mechanisms of ...
Greve T - - 2001
Herpesvirus saimiri is capable of transforming T lymphocytes of various primate species to stable growth in culture. The interaction of the T-cellular tyrosine kinase p56(lck) with the transformation-associated viral protein Tip has been shown before to activate the kinase and provides one model for the T-cell-specific transformation by herpesvirus saimiri ...
Min D S - - 2001
Phospholipase D (PLD) has been suggested to play an important role in a variety of cellular functions. PLD activity has been shown to be significantly elevated in many tumours and transformed cells, suggesting the possibility that PLD might be involved in tumorigenesis. In this study, we have established stable cell ...
Koerner F C - - 2001
This study seeks to define the morphological pathogenesis of a form of cystic transformation of lobules referred to as atypical cystic lobule or low-grade clinging carcinoma of flat type. We collected 25 examples that seem to represent the early stages in the formation of atypical cystic lobules and made a ...
Liu A X - - 2001
RhoB is an endosomal small GTPase that is implicated in the response to growth factors, genotoxic stress, and farnesyltransferase inhibitors. To gain insight into its physiological functions we examined the consequences of homozygous gene deletion in the mouse. Loss of RhoB did not adversely affect mouse development, fertility, or wound ...
Danve C - - 2001
The Epstein-Barr virus (EBV) is associated with two major human epithelial malignancies, where it is likely to play a role in the malignant phenotype: undifferentiated nasopharyngeal carcinoma (100% of cases) and gastric carcinomas (about 10% of cases). We and others have obtained growth transformation of monkey kidney primary epithelial cells ...
Suga M - - 2001
A highly efficient method for transformation of the fission yeast Schizosaccharomyces pombe by electroporation has been developed. Significantly higher transformation efficiency was obtained when intact cells grown in SD medium (0.67% Bacto yeast nitrogen base without amino acids, 2% glucose) were pretreated with thiol compounds before an electric pulse was ...
Marras E - - 2001
We have recently demonstrated that overexpression of PKCepsilon is oncogenic in colonic epithelial cells. To test whether PI3K might be an upstream effector of PKCepsilon in cell transformation, we have overexpressed the p110alpha PI3K subunit in non-transformed D/WT colonic epithelial cells. Transfectants displayed the major in vitro features of transformed ...
Fink D - - 2001
In this study procaspase expression levels were investigated by Western blotting in a panel of established melanoma cell lines, transformed melanocytic cell lines and normal primary melanocytes. Upstream caspases such as procaspase-8 that contain a death effector domain were found to be overexpressed in transformed melanocytes and melanoma cell lines ...
Sakai A - - 2001
Two hydroquinones with similar structures, 2,5-di-tert-butyl-1,4-hydroquinone (DTBHQ) and 2-tert-butyl-1,4-hydroquinone (MTBHQ), are used as antioxidants in the environment. DTBHQ and MTBHQ were examined for their ability to induce cell transformation using BALB/3T3 cells. DTBHQ at concentrations of 2.5-15 microM enhanced cell transformation initiated by a subthreshold dose (0.75 microM) of 3-methylcholanthrene ...
Meinl E - - 2001
The protein tyrosine kinase ZAP-70 plays a pivotal role involved in signal transduction through the T cell receptor and CD2. Defects in ZAP-70 result in severe combined immunodeficiency. We report that Herpesvirus saimiri, which does not code for a ZAP-70 homologue, can replace this tyrosine kinase. H. saimiri is an ...
Rovensky YuA - - 2001
The behaviour of epitheliocytes, their transformed analogues, and fibroblasts was studied on special culture substrates--lattices with large square openings (the area of an opening was 2000 microm2). It was shown that normal epithelocytes and fibroblasts initially attached to and spread on the lattice bars, were soon displaced into the lattice ...
Kanai H - - 2001
Estrogenicity is an important mechanism in hormonal carcinogenesis but not sufficient to explain the carcinogenic activity of all estrogens. Additional mechanisms, related to genetic alterations, in conjunction with estrogenicity mediated through the estrogen receptor, have been suggested. An environmental estrogen bisphenol-A (BP-A) and its analogs are widespread in our living ...
Sakai A - - 2001
p-Nonylphenol (NP) has attracted attention as an estrogenic contaminant, and the environmental pollution by NP has been found to be extensive. NP is classified as a phenolic antioxidant based on the chemical activity and structure. Some phenolic antioxidants are known to induce and/or enhance carcinogenesis. We examined the effects of ...
Dustin M L - - 2001
The stable immunological synapse between a T cell and antigen-presenting cell coordinates migration and activation. Three-dimensional collagen gels transform this interaction into a series of transient hit-and-run encounters. Here we integrate these alternative modes of interaction in a model for primary T cell activation and effector function in vivo.
Lamblin Frédéric - - 2001
The Arabidopsis thaliana sam1 gene encoding S-adenosylmethionine synthetase (EC 2.5.1.6) was transferred to flax (Linum usitatissimum) cells via Agrobacterium tumefaciens. This enzyme catalyses the conversion of methionine to S-adenosylmethionine (SAM), the major methyl group donor in living cells. The aim of this work was to study the consequences of an ...
Fedele M - - 2001
The high mobility group (HMG) proteins (HMGA1a, HMGA1b, and HMGA2) bind to DNA and interact with various transcriptional factors. Therefore, they play an important role in chromatin organization. HMGA protein expression is low in normal adult tissues, but abundant during embryonic development and in several experimental and human tumors. Blockage ...
Keshava N - - 2001
Occupational exposure to beryllium (Be) and Be compounds occurs in a wide range of industrial processes. A large number of workers are potentially exposed to this metal during manufacturing and processing, so there is a concern regarding the potential carcinogenic hazard of Be. Studies were performed to determine the carcinogenic ...
Coniglio S J - - 2001
Rho family members play a critical role in malignant transformation. Anchorage-independent growth and the ability to avoid apoptosis caused by loss of anchorage (anoikis) are important features of transformed cells. Here we show that constitutive activation of Rac1 inhibits anoikis in Madin-Darby canine kidney (MDCK) epithelial cells. Constitutively active Rac1-V12 ...
Wang Z - - 2001
Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded with the whole-cell patch-clamp technique from 41 pyramidal cells in the layers V-VI of the prelimbic (PL) cortex. The sEPSCs occurred randomly and the averaged frequency in 41 cells was 1.81+/-0.27 Hz. The amplitude distribution was skewed toward larger events and could be ...
Bodey B - - 2001
Structural changes in the extracellular matrix (ECM) are necessary for cell migration during normal and pathologic tissue remodeling and neoplastic cell invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been identified to be critical modulators of ECM composition and are thus, crucial in neoplastic cell progression, invasion and metastasis. ...
Gilbert J - - 2001
This basic protocol presents Epstein-Barr virus (EBV) transformation of B cells to create a permanent cell line to provide cells for genetic and DNA analysis. Virus stocks are prepared from cultures of an infected marmoset cell line in the first support protocol. Transformed cells may be analyzed immediately or frozen ...
Ruggieri R - - 2001
BACKGROUND: The small GTPase Rac1 is a key signaling protein that mediates a number of important physiologic functions including the organization of the actin cytoskeleton, lipid metabolism, and gene transcription. Rac1 has also been implicated in oncogenic transformation. Expression of constitutively active Rac1 in Rat1 fibroblasts elicits serum- and anchorage-independent ...
Yoon H S - - 2001
Although hydroquinone (HQ) is a rodent carcinogen, because of its lack of mutagenicity in standard bacterial mutagenicity assays it is generally considered a nongenotoxic carcinogen. 2,3,5-Tris-(glutathion-S-yl)HQ (TGHQ) is a potent nephrotoxic metabolite of HQ that may play an important role in HQ-mediated nephrocarcinogenicity. TGHQ mediates cell injury by generating reactive ...
Barkett M - - 2001
The retroviral oncoprotein v-Rel is a transcriptional activator in the Rel/NF-kappa B family. v-Rel causes rapidly fatal lymphomas in young chickens, and transforms and immortalizes chicken lymphoid cells in vitro. Several mutations that have enhanced the oncogenicity of v-Rel have been selected during in vitro and in vivo passage of ...
Ho C K - - 2001
Using five trophoblast cell lines of different differentiation status, we have shown that trophoblasts could constitutively release the transforming growth factor beta-1 (TGFbeta1), but not TGFbeta2. Treatment of the human tumorigenic, TL, and BeWo cells with a differentiating agent and a potent protein kinase C activator--the tumor-promoting agent--or the JEG-3 ...
David K M - - 2001
Manipulating the expression of a transgene in transient and stable transformed cells is a requirement for many functional analyses. We have investigated the use of the tetracycline-dependent gene expression system developed by Gatz et al. (1992) in tobacco (Nicotiana tabacum L. cv Bright Yellow 2 [BY2]) cells, the most widely ...
Richardson J H - - 2001
Fluorescence in situ hybridisation (FISH) was employed to identify the chromosomal integration site of the human T-cell lymphotropic virus, type 1 (HTLV-1) present in T-cell clones derived from HTLV-1-infected individuals and a virally transformed cell line, C8166-45. Proviral sequences were detected in C8166-45 but not uninfected Jurkat cells. Integration sites ...
Fang M Z - - 2001
During the multistage carcinogenesis, functions of several key genes involved in the cell cycle control and cell-cell communication can be damaged. Gap junction intercellular communication (GJIC) is known to transfer small, water-soluble molecules through intercellular channels composed of proteins called connexins (Cxs). Therefore, aberrant expression of Cx may be one ...
Buser C A - - 2001
Cellular transformation by Ras oncoproteins requires the posttranslation modification of farnesylation in a reaction catalyzed by farnesyl protein transferase (FPTase). Thus, inhibitors of FPTase have been developed as potential anticancer agents. However, recent studies with selective inhibitors of FPTase have shown that Ki4B-Ras retains its ability to transform cells by ...
Rubin H - - 2001
Recent analysis of genetic alterations in human cancer points to a major role for selection in neoplastic development but provides few details about the dynamics of the process. Many such details, however, have emerged from quantitative studies of spontaneous transformation among mammalian cells in culture. The chief insight of these ...
Pawlak G - - 2001
Research during the past couple of years has provided important new information as to how the actin cytoskeleton contributes to growth control in both normal and transformed cells. The cytoskeleton can no longer be viewed as simply a structural framework playing a role in cell shape and motile events such ...
Krishnamoorthy R R RR Department of Pathology and Anatomy, UNT Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, - - 2001
The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the psi2 E1A virus. In order to isolate retinal ganglion cells (RGC), single ...
Kunik T - - 2001
Agrobacterium tumefaciens is a soil phytopathogen that elicits neoplastic growths on the host plant species. In nature, however, Agrobacterium also may encounter organisms belonging to other kingdoms such as insects and animals that feed on the infected plants. Can Agrobacterium, then, also infect animal cells? Here, we report that Agrobacterium ...
Ilinskaya O - - 2001
The antiproliferative action of the guanine-specific ribonuclease secreted by Bacillus intermedius (binase) was studied in different chicken and mouse cell lines. The proliferation rate of chicken embryo fibroblasts, either normal or Rous sarcoma virus-transformed, was significantly reduced by binase treatment. Among mouse fibroblasts, v-ras-transformed NIH3T3 cells were sensitive to binase, ...
Rao K V - - 2001
Malachite green (MG), consisting of green crystals with a metallic luster, is highly soluble in water, cytotoxic to various mammalian cells, and may act as a liver tumor promoter. In view of its industrial importance and possible exposure to human beings, MG poses a potential environmental health hazard. We have ...
Russo J - - 2001
The morphological analysis of breast cancer development indicates this to be a multistep process that progressively evolves from ductal hyperplasia and atypical ductal hyperplasia, which represent the initial stages of neoplastic growth, to carcinoma in situ, invasive carcinoma, and ultimately metastasis, as has been documented for a number of other ...
Barr S M - - 2001
Levels of Puralpha, a conserved, sequence-specific single-stranded DNA and RNA binding protein, fluctuate during the cell cycle, declining at the onset of S-phase and peaking at mitosis. In early G1 Puralpha is associated with the hypophosphorylated form of the retinoblastoma protein, Rb. Microinjection of purified Puralpha into NIH3T3 cells arrests ...
Sakaguchi M - - 2001
Many lines of evidence indicate that the immortalization step is critical for the neoplastic transformation of normal human cells. Once normal human cells have been immortalized, they are relatively easily transformed into neoplastic cells. In order to understand these phenomena, patterns of protein phosphorylation in proliferating normal human fibroblast cell ...
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