279 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Cell Cultures"  
Results: 1 - 24 next
open access

Growth regulation by macrophages

Description: The evidence reviewed here indicates that macrophages, either acting alone or in concert with other cells, influence the proliferation of multiple types of cells. Most of the data indicate that these effects are mediated by soluble macrophage-elaborated products (probably proteins) although the role of direct cell-to-cell contacts cannot be ruled out in all cases. A degree of success has been achieved on the biochemical characterization of these factors, due mainly to their low specific activit… more
Date: January 1, 1982
Creator: Wharton, W.; Walker, E. & Stewart, C.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Presence of UV-endonuclease sensitive sites in daughter DNA of UV-irradiated mammalian cells. [3H-thymidine tracer]

Description: Asynchronous Chinese hamster cells were irradiated with 10 Jm/sup -2/ uv radiation and 0.25 to 4 hours later pulse-labeled with (/sup 3/H)thymidine. Cells synchronized by shaking off mitotic and G/sub 1/ cells were irradiated in either the G/sub 1/-phase or S-phase of the cell cycle and pulse-labeled with (/sup 3/H)thymidine in the S-phase. After a 12 to 14 hour chase in unlabeled medium, the DNA was extracted, incubated with Micrococcus luteus uv-endonuclease and sedimented in alkaline sucrose… more
Date: February 1, 1978
Creator: D'Ambrosio, S. & Setlow, R.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Excision repair of bulky lesions in the DNA of mammalian cells

Description: The report examines the process of excision repair of pyrimidine dimers from uv-irradiated and chemically challenged human cells. It is shown by means of a sensitive endonuclease assay that the amount of excision observed depends upon the isotope used to label cells, and that XP heterozygotes are between normals and XPs. (ACR)
Date: January 1, 1980
Creator: Setlow, R B & Grist, E
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Cell-mediated mutagenesis by chemical carcinogens

Description: The cell-mediated mutation system, with the proper choice of metabolizing cells, can be used to detect the mutagenic activities of different classes of chemical carcinogens. When fibroblastic cells were used as the metabolizing cells, a correlation between the in vivo carcinogenic activity and the in vitro mutagenic activity of 11 aromatic polycyclic hydrocarbons was observed. When primary liver cells were used as the metabolizing cells, three known liver carcinogens were demonstrated to be mut… more
Date: January 1, 1978
Creator: Huberman, E. & Langenbach, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Biomedical applications of digital autoradiography with a MWPC

Description: A Multiwire Proportional Chamber (MWPC) was used as a ..beta../sup -/ radioactivity detector in biological and medical applications. Two different kinds of experiments were performed: the study of variations in the ability of cell clones to incorporate a radioactive precursor of DNA biosynthesis (/sup 3/H-thymidine) and the regional carbohydrate consumption in myocardial tissue by means of a deposit tracer of glucose metabolism (/sup 3/H-deoxyglucose).
Date: May 1, 1982
Creator: Bellazzini, R.; Betti, G.; Del Guerra, A.; Massai, M. M.; Ragadini, M.; Spandre, G. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

DNA repair in human cells exposed to combinations of carcinogenic agents

Description: Normal human and XP/sup 2/ fibroblasts were treated with uv plus uv-mimetic chemicals. The uv dose used was sufficient to saturate the uv excision repair system. Excision repair after combined treatments was estimated by unscheduled DNA synthesis, BrdUrd photolysis, and the loss of sites sensitive to a uv specific endonuclease. Since the repair of damage from uv and its mimetics is coordinately controlled we expected that there would be similar rate-limiting steps in the repair of uv and chemic… more
Date: January 1, 1980
Creator: Setlow, R.B. & Ahmed, F.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Regulation of hemopoiesis: inhibitors and stimulators produced by a murine bone marrow stromal cell line (H-1)

Description: A murine cell line (H-1) probably derived from the adventitial reticular cell has been isolated and preserved. This line produces: (1) CSF; (2) a labile inhibitor of CFU-c proliferation with preferential action on granulopoiesis; (3) PGE; (4) proliferation inhibitors of BFU-E and GEMM; and (5) suppression of entry of CFU-S into DNA synthesis in vitro. It is postulated that the adventitial reticular cell (ARC) may play a major regulatory role in hemopoiesis through intramedullary production of t… more
Date: January 1, 1982
Creator: Cronkite, E. P.; Miller, M. E.; Garnett, H. & Harigaya, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Toxicologic studies of SRC materials

Description: Investigations on the toxicity of SRC materials are reported. Toxicological studies include: microbial mutageneis (Ames test); in vitro mammalian cell toxicity and transformation assays; epidermal carcinogenesis (skin painting); acute and subchronic oral toxicity; developmental toxicity; dominant lethal assays; inhalation toxicity; and dosimetry and metabolism. The materials tested include: SRC-I process solvent, wash solvent, and light oil; SRC-II heavy distillate, middle distillate, and light… more
Date: February 1, 1980
Creator: Mahlum, D. D.; Pelroy, R. A.; Drucker, H.; Wilson, B. W.; Massey, M. J. & Schmalzer, D. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Health effects of combustion-generated soot and polycyclic aromatic hydrocarbons. Progress report, May 1, 1979-April 30, 1980. [Lead abstract]

Description: Mutagen studies on soot and soot components are reported in aspects dealing from quantitative chemical analyses of samples and mutagenesis of cells and microorganisms exposed to mutagens, to bioassay developments and techniques. Several polycyclic aromatic hydrocarbons are characterized and discussed.
Date: May 1, 1980
Creator: Thilly, W. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Radiobiology of pions at LAMPF

Description: Recent radiobiology data for pion beams used in therapy are presented. The biological systems used were cultured cells suspended in gelatin and intestinal crypt assay. The importance of fast neutrons from pion stars in large treatment volumes is discussed. The data for compensating the depth dose distribution to produce uniform cell killing across the peak region are presented. The changes in biological effectiveness with peak width for pion beams (unlike heavy ions) are small because of fast n… more
Date: January 1, 1982
Creator: Raju, M.R. & Tokita, N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

DNA replication and the repair of DNA strand breaks in nuclei of Physarum polycephalum. Terminal report, August 1, 1978-March 31, 1980

Description: Nuclei isolated from Physarum are able to replicate approximately 15% of the total genome in a manner which is qualitatively similar to the DNA replication process occurring in the intact organism. Such nuclei, however, are defective in the joining of Okazaki intermediates in vitro. Two DNA polymerase species, isolated from nuclei or intact plasmodia of this organism, can be separated by sucrose density gradient centrifugation. Total DNA polymerase activity is low in nuclei isolated during mito… more
Date: January 1, 1980
Creator: Brewer, E. N. & Evans, T. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Quantitative and molecular analyses of mutation in a pSV2gpt transformed CHO cell line

Description: Following NDA-mediated gene transfer we have isolated a cell line useful for studying gene mutation at the molecular level. This line, AS52, derived from a hypoxanthine-guanine phosphoribosyl transferase (HGPRT) deficient Chinese hamster ovary (CHO) cell line, carries a single copy of the E. coli xanthine-guanine phosphoribosyl transferase (XGPRT) gene (gpt) and exhibits a spontaneous mutant frequency of 20 TG/sup r/ mutants/10/sup 6/ clonable cells. As with HGPRT/sup -/ mutants, XGPRT/sup -/ m… more
Date: January 1, 1983
Creator: Stankowski, L.F. Jr.; Tindall, K.R. & Hsie, A.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Annual progress report, July 1, 1979-June 30, 1980

Description: Research progress is reported for the year 1979-1980. The report is divided into sections dealing individually with the divisions of Biomolecular and Cellular Science, Environmental Biology, and Nuclear Medicine. The sections have been individually entered into EDB. (ACR)
Date: January 1, 1980
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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

Linear-quadratic dose kinetics or dose-dependent repair/misrepair

Description: Models for the response of cells exposed to low LET radiation can be grouped into three general types on the basis of assumptions about the nature of the interaction which results in the shoulder of the survival curve. The three forms of interaction are (1) sublethal damage becoming lethal, (2) potentially lethal damage becoming irreparable, and (3) potentially lethal damage saturating'' a repair system. The effects that these three forms of interaction would have on the results of specific typ… more
Date: September 1, 1991
Creator: Braby, L.A. & Nelson, J.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Specificity of interaction between carcinogenic polynuclear aromatic hydrocarbons and nuclear proteins: widespread occurrence of a restricted pattern of histone-binding in intact cells

Description: Metabolic activation of benzo(a)pyrene (B(a)P) produces a number of potentially reactive metabolites. The endproducts of one metabolic pathway, 7,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydro-B(a)P (BPDE) are responsible for essentially all DNA adduct formation in animal cells treated with B(a)P, and a particular stereoisomer, designated (+)-anti-BPDE is thought to be the ultimate carcinogenic derivative of B(a)P. In hamster embryo cell nuclei treated with (+)-anti-BPDE, two of the histones of the n… more
Date: January 1, 1982
Creator: MacLeod, M. C.; Pelling, J. C.; Slaga, T. J.; Nikbakht-Noghrei, P. A.; Mansfield, B. K. & Selkirk, J. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Characterization of Metal Binding Peptides From Cadmium Resistant Plant Cells

Description: The majority of the cellular cadmium (<80%) in cadmium resistant Datura innoxia cells is bound to a small, metal induced peptide which is not metallothionein. This peptide consists of glutamate, cysteine and glycine in a ratio between 2:2:1 and 3:3:1 and has an apparent molecular weight of 776, under denaturing conditions. It is heat stable and complexes with cadmium to produce multimeric forms which are separable by gel filtration. Chemical analyses suggest that some amino acids are not joined… more
Date: January 1, 1985
Creator: Robinson, N. J.; Barton, K.; Naranjo, C. M.; Sillerud, L. O.; Trewhella, J.; Watt, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen