Search results for "cell culture"

Cytogenetic effects of promutagens in genetically engineered V79 Chinese hamster cells expressing cytochromes P450.

1993

Abstract V79 Chinese hamster cell lines genetically engineered to express rat CYP2B1, CYP1A1, CYP1A2, and their parental cell lines V79-MZ, without acetyltransferase, and V79-NH, with acetyltransferase, were studied for chromosome aberrations and sister chromatid exchange induced by aflatoxin B 1 , cyclophosphamide, benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene and dimethylnitrosamine. The parental V79 cell lines did not show clastogenic effects. Significant clastogenic effects were observed after an 18 h exposure to aflatoxin B 1 and cyclophosphamide in CYP2B1 expressing cells, to benzo[a]pyrene in CYP1A1 and CYP1A2 expressing cells, to 7,12-dimethylbenz[a]anthracene and dimethylnitrosami…

Changes in metabolism of inorganic polyphosphate in rat tissues and human cells during development and apoptosis

1997

Age-dependent studies show that the amount of inorganic polyphosphate in rat brain strongly increases after birth. Maximal levels were found in 12-months old animals. Thereafter, the concentration of total polyphosphate decreases to about 50%. This decrease in the concentration of total polyphosphate is due to a decrease in the amount of insoluble, long-chain polyphosphates. The amount of soluble, long-chain polyphosphates does not change significantly in the course of ageing. In rat embryos and newborns, mainly soluble polyphosphates could be detected. In rat liver, the age-dependent changes are less pronounced. The changes in polyphosphate level are accompanied by changes in exopolyphosph…

Activation by mitogens and superantigens of axolotl lymphocytes: functional characterization and ontogenic study.

1996

Urodele amphibians have weak and slow immune responses compared to mammals and anuran amphibians. Using new culture conditions, we tested the ability of lymphocytes of a well-studied salamander, the Mexican axolotl (Ambystoma mexicanum) to proliferate in vitro with diverse mitogenic agents. We demonstrated that the axolotl has a population of B lymphocytes that proliferate specifically and with a high stimulation index to the lipopolysaccharide (LPS) known as a B-cell mitogen in mammals. This proliferative capacity is observed without significant changes throughout ontogenesis. In the presence of LPS, axolotl B lymphocytes are able to synthesize and secrete both isotopes of immunoglobulin d…

Primmorphs generated from dissociated cells of the sponge Suberites domuncula: a model system for studies of cell proliferation and cell death

1999

Sponges (Porifera) represent the lowest metazoan phylum; they have been shown to be provided with the characteristic metazoan structural and functional molecules. One autapomorphic character of sponges is the presence of high levels of telomerase activity in all cells (or almost all cells, including somatic cells). In spite of this fact previous attempts to cultivate sponge cells remained unsuccessful. It was found that dissociated sponge cells do not replicate DNA and lose their telomerase activity. In addition, no nutrients or metabolites have been detected that would stimulate sponge cells to divide. In the present study we report the culture conditions required for the formation of mult…

Exposure to gp120 of HIV-1 induces an increased release of arachidonic acid in rat primary neuronal cell culture followed by NMDA receptor-mediated n…

1995

After incubation of highly enriched neurons from rat cerebral cortex with the HIV-1 coat protein gp120 for 18 h, cells showed fragmentation of DNA at internucleosomal linkers followed by NMDA receptor-mediated neurotoxicity. We report that in response to exposure to gp120 cells react with an increased release of arachidonic acid (AA) via activation of phospholipase A2. This process was not inhibited by NMDA receptor antagonists. To investigate the role of AA on the sensitivity of the NMDA receptor towards its agonist, low concentrations of NMDA were co-administered with AA. This condition enhanced the NMDA-mediated cytotoxicity. Administration of mepacrine reduced cytotoxicity caused by gp1…

Selection and characterization of a novel agonistic human recombinant anti-Trail-R2 minibody with anti-leukemic activity

2009

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising natural anticancer therapeutic agent because through its “death receptors”, TRAIL-R1 and TRAIL-R2, it induces apoptosis in many transformed tumor cells, but not in the majority of normal cells. Hence, agonistic compounds directed against TRAIL death receptors have the potential of being excellent cancer therapeutic agents, with minimal cytotoxicity in normal tissues. Here, we report the selection and characterization of a new single-chain fragment variable (scFv) to TRAIL-R2 receptor isolated from a human phage-display library, produced as minibody (MB), and characterized for the in vitro anti-leukemic tumoricid…

LXR antagonists induce ABCD2 expression

2014

X-linked adrenoleukodystrophy (X-ALD) is a rare neurodegenerative disorder characterized by the accumulation of very-long-chain fatty acids resulting from a beta-oxidation defect. Oxidative stress and inflammation are also key components of the pathogenesis. X-ALD is caused by mutations in the ABCDI gene, which encodes for a peroxisomal half ABC transporter predicted to participate in the entry of VLCFA-CoA into the peroxisome, the unique site of their beta-oxidation. Two homologous peroxisomal ABC transporters, ABCD2 and ABCD3 have been proven to compensate for ABCD1 deficiency when overexpressed. Pharmacological induction of these target genes could therefore represent an alternative ther…

Aldosterone synthase activity in the Y-1 adrenal cell line.

1995

The Y-1 adrenal cell line was shown to produce 20 alpha-dihydroaldosterone from deoxycorticosterone. This compound was identified by GC-MS by comparison with the previously synthesized reference compound. Two other 18-hydroxylated metabolites were identified as 11 beta,18-dihydroxy-20 alpha-dihydroprogesterone from endogenous cholesterol and 18-hydroxy-20 alpha-dihydro-11-dehydrocorticosterone from DOC. The conditions necessary for the synthesis of these compounds are culturing in 20% serum-supplemented medium and repeated incubations with the substrate. The production of 11 beta-hydroxylated steroids and that of 18-oxygenated steroids is stimulated differently by ACTH and angiotensin II su…

Oxygen profile of microencapsulated islets: effect of immobilised hemoglobin in the alginate matrix

2001

Karyotype Abnormalities in a Variant Chinese Hamster Cell Line Resistant to Methyl Methanesulphonate

2004

A variant cell population, isolated from V79-CI 3 Chinese hamster cells after two consecutive treatments with methyl methanesulphonate (MMS), was found to be highly resistant to killing by this alkylating agent. The resistant cell line was cytogenetically characterized both by the presence of a stable translocation involving metacentric chromosome 2 and acrocentric chromosome 6 and by a supernumerary chromosome originated by the duplication of a small telocentric chromosome. This cell population also showed a transient transformed phenotype, seen as formation of transformed foci containing cells with high chromosomes counts and multiple chromosomal aberrations. As MMS-resistance and karyoty…