13 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Cell Cultures"  
Results: 1 - 13
open access

Cell-mediated mutagenesis and cell transformation by chemical carcinogens

Description: Results are reported from studies that showed that mutagenesis of mammalian cells can be achieved by carcinogenic polycyclic hydrocarbons, nitrosamines, and aflatoxins when tested in the presence of fibroblasts and hepatocytes which are able to metabolize these carcinogens. Further, we have found that there is a relationship between the degree of mutant induction and the degree of carcinogenicity of the different chemicals tested. By simultaneously measuring the frequency of cell transformation… more
Date: January 1, 1977
Creator: Huberman, E. & Langenbach, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Metabolism of benzo(a)pyrene: comparison of rodent liver and embryonic cells in tissue culture. [Rats, hamsters, mice]

Description: Rats, hamsters, and mice were given intraperitoneal injections of methylcholanthrene and were killed 40 h later. Liver microsomes were prepared and metabolites were formed by incubating rat liver microsomes or homogenized cells with /sup 3/H-labeled benzopyrene. Results indicated that the hydroxylase systems in the three species have different specificities for particular regions of the benzopyrene molecule. Metabolite profiles for benzopyrene were compared in hamster cells and mouse embryonic … more
Date: January 1, 1977
Creator: Selkirk, J. K. & MacLeod, M. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Methods for the isolation and identification of polycyclic aromatic hydrocarbons found in complex mixtures and the determination of their possible toxicity by means of a host mediated bioassay technique. Progress report, July 1, 1976--February 1, 1977. [Cultured mouse leumemia cell bioassay system]

Description: Techniques were developed to produce excellent high performance glass capillary columns for gas chromatographic analyses of a wide range of complex mixtures of organic compounds, including those containing a wide array of polycyclic aromatic hydrocarbons (PAH) derived from a coal liquefaction process. Work was begun to assess the potential mutogenicity and/or carcinogenicity of the various isolated PAH fractions utilizing a unique host mediated bioassay system. Preliminary results indicate that… more
Date: February 1, 1977
Creator: Lipsky, S. R.; Alexander, G.; McMurray, W. & Capizzi, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

X-ray-induced chromosome aberrations in the leukocytes of mouse and man

Description: In our earlier studies we showed that the frequency of dicentrics induced by x-rays in human leukocytes was about twice that induced in mouse leukocytes. The frequencies of deletions were similar in both species. However, the mouse cultures were fixed at 60 hrs and the human cultures at 54 hrs. In both cases it was likely that some of the cells analyzed were in their second post-treatment mitosis. Further studies were carried out using fixation times of 48 hrs for both human and mouse cultures.… more
Date: January 1, 1977
Creator: Preston, R. J. & Brewen, J. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Uptake and fate of ouabain bound to HeLa cells. [/sup 3/H tracer study]

Description: The first step in the pharmacologic interaction of a cardiac glycoside with cells is the binding of the drug to its specific surface receptor, an exteriorly oriented site of the Na/sup +/--K/sup +/ ATPase. The purpose of the study outlined was to follow a glycoside from its initial binding to its ultimate release from a sensitive cell, and in parallel studies to observe the recovery of the cells from glycoside intoxication. The glycoside used is /sup 3/H-ouabain, and the cells are from the S3 c… more
Date: January 1, 1977
Creator: Cook, J. S. & Brake, E. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Flow-System Multiangle Light-Scattering Studies. A Progress Report

Description: Progress is reported on the analysis of particles and tissue culture cells by multiangle light-scattering measurements. The instrument is a 3-mW helium-neon laser beam (632.8 nm wavelength) focused by a 150-mm focal length spherical lens into a saline-filled (n = 1.3345) flow chamber where it intersects a sheath flow encased 20- to 30-..mu..m diameter saline sample stream. Light scattered from a cell in the sample stream is detected by a photodiode array containing 32 individual photodiodes in … more
Date: January 1, 1977
Creator: Salzman, G. C.; Burger, D. E.; Bartholdi, M. & Price, B. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Combined effects of hyperthermia and radiation in cultured mammalian cells

Description: Hyperthermia (temperatures of 39/sup 0/C or higher) enhances the killing of mammalian cells by ionizing radiation (fission-spectrum neutrons and x-rays). The nature and the magnitude of the enhanced radiation killing varies with temperature and for a fixed temperature during irradiation, the enhanced lethality varies inversely with dose rate. For temperatures up to 41/sup 0/C, dose fractionation measurements indicate that hyperthermia inhibits the repair of sublethal damage. At higher temperatu… more
Date: January 1, 1977
Creator: Ben-Hur, E.; Elkind, M. M. & Riklis, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Mathematical analysis of DNA histograms from asynchronous and synchronous cell populations

Description: A technique is presented for the analyss of DNA histograms which is an extension of earlier discrete Gaussian summing methods. It alleviates the problems encountered with previous methods by extending the S-phase portions of the distribution under the G/sub 1/ and G/sub 2/ + M peaks. The resuts obtained by this method for the fraction of cells in the G/sub 1/, S, and G/sub 2/ + M phases of the life cycle are compared with autoradiographic results. With one or two exceptions which are discussed,… more
Date: January 1, 1977
Creator: Jett, J. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Molecular events basic to cellular radiation response. Progress report, July 1, 1976--September 30, 1977

Description: Progress is reported on studies of the effects of x irradiation at the cellular level that lead ultimately to either malignant transformation or cell death. Experimental results consistent with the primer hypothesis for the regulation of gene expression in eukaryotes are reported. It was found that oligonucleotides can be inserted en bloc into newly synthesized RNA. Studies on amino acid-nucleic acid interactions were continued by successfully synthesizing an amidate and beginning NMR studies o… more
Date: January 1, 1977
Creator: Kolodny, G. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Flow microfluorometric and spectrophotofluorometric analysis of DNA staining in mammalian cells

Description: The effects of pH, ionic strength, stain concentration, and magnesium concentration on DNA staining with the antibiotics mithramycin, chromomycin A3, and olivomycin were examined with DNA in solution and in mammalian cells. Ethanol-fixed Chinese hamster cells (line CHO) stained with mithramycin solution in the pH range 4.0 to 10.0 and analyzed by flow microfluorometry (FMF) showed only a slight increase in fluorescence intensity from pH 4.0 to 8.0. Above this range, there was a more dramatic in… more
Date: January 1, 1977
Creator: Crissman, H. A.; Stevenson, A. & Kissane, R. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Proteins in growth regulation during early development. Comprehensive three year report, 1974--1977

Description: Progress is reported on the following research projects: response of embryo regions to nutrition; synthesis of serum proteins by the yolk-sac; serum protein synthesis in relation to protein nutrition, protease secretion, teratogenic agents, genetic abnormalities, yolk-sac cell cultures, and cell free systems; and effects of serum proteins on rat embryos, chick embryos without yolk-sacs, and isolated brains. (HLW)
Date: August 1, 1977
Creator: Klein, N. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Proteins in growth regulation during early development. Progress report, 1976--1977

Description: Studies were conducted to determine mechanisms regulating the synthesis of serum proteins by the yolk-sac and to determine if serum proteins are developmental signals. Synthesis of serum proteins in the yolk-sac and liver was determined at various stages of development and effects of teratogenic agents and genetic mutations on protein synthesis were studied. The regulation of serum protein synthesis was studied in cell cultures and in cell-free protein synthesizing systems derived from the yolk… more
Date: August 1, 1977
Creator: Klein, N. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen