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S L Anderson

Publications and source records attributed to S L Anderson.

67 records · Page 4Linked to original sources
PubMed1987

Radiation-induced micronuclei in peripheral erythrocytes of Rana catesbeiana: an aquatic animal model for in vivo genotoxicity studies.

An in vivo micronucleus assay for peripheral erythrocytes of Rana catesbeiana tadpoles was developed and evaluated. The assay was used to determine the spontaneous frequency of micronuclei in circulating erythrocytes in tadpoles from two different populations, to define the time from administering the clastogen to the maximum micronucleus frequency in peripheral erythrocytes, and to determine the response to radiation. The spontaneous frequency of micronuclei in circulating erythrocytes of early-stage tadpoles was low (3.6 +/- 2.8 micronuclei per 1,000 erythrocytes, MN o/oo), but higher than that of late-stage tadpoles (1.7 +/- 0.7 MN o/oo). The time from the exposure of early-stage tadpoles to radiation (2.1 Gy) to the maximum micronucleus frequency was about 2 wk. The increase in frequency of micronuclei in peripheral erythrocytes of late-stage tadpoles receiving doses ranging from 0.5 to 3.0 Gy was linear with dose; a 3-fold increase was obtained with a dose of 3.0 Gy. The spontaneous frequency of micronuclei in erythrocytes and the increase in frequency induced by radiation appeared to differ in tadpoles from different populations. Quantification of micronuclei in the peripheral erythrocytes of R catesbeiana tadpoles provides a promising whole-animal system for studies of genotoxicity in aquatic environments.

Animals↗
PubMed1986

Nonhematopoietic cells selected for resistance to tumor necrosis factor produce tumor necrosis factor.

TNF-resistant lines of L cells can be derived from TNF-sensitive populations by repeated exposure to TNF, and these resistant L cells, in contrast to sensitive L cells and other types of cells, lack demonstrable cell surface receptors for TNF. We have now found that TNF-resistant L cells produce a factor that is cytotoxic for L cells and has the following distinguishing characteristics of mouse TNF: it is a protein of 43 kD, composed of 16 kD subunits, that competes with TNF for receptor binding, induces hemorrhagic necrosis of the TNF-sensitive mouse sarcoma Meth A, has synergistic cytotoxic action with interferon, and its activity is neutralized by antibody to TNF. The two conclusions of this study are that cells selected for TNF resistance spontaneously produce a molecule resembling macrophage TNF, and that cells of nonhematopoietic origin are capable of producing TNF.

Animals↗
PubMed1986

The suppressive influences of human tumor necrosis factors on bone marrow hematopoietic progenitor cells from normal donors and patients with leukemia: synergism of tumor necrosis factor and interferon-gamma.

The influences of human tumor necrosis factor (TNF) (LuKII), recombinant human TNF-alpha, natural human interferon-gamma (HuIFN-gamma), recombinant HuIFN-gamma, and natural HuIFN-alpha were evaluated alone or in combination for their effects in vitro on colony formation by human bone marrow granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells incubated at 5% CO2 in lowered (5%) O2 tension. TNF (LuKII) and recombinant TNF-alpha caused a similar dose-dependent inhibition of colony formation from CFU-GM, BFU-E, and CFU-GEMM. Day 7 CFU-GM colonies were more sensitive than both day 14 CFU-GM colonies and day 7 CFU-GM clusters to inhibition by TNF. BFU-E colonies and CFU-GEMM colonies were least sensitive to inhibition with TNF. The suppressive effects of TNF (LuKII) and recombinant TNF-alpha were inactivated respectively with hetero-anti-human TNF (LuKII) and monoclonal anti-recombinant human TNF-alpha. The hetero-anti-TNF (LuKII) did not inactivate the suppressive effects of TNF-alpha and the monoclonal anti-recombinant TNF-alpha did not inactivate TNF (LuKII). The suppressive effects of TNF did not appear to be mediated via endogenous T lymphocytes and/or monocytes in the bone marrow preparation, and a pulse exposure of marrow cells with TNF for 60 min resulted in maximal or near maximal inhibition when compared with cells left with TNF for the full culture incubation period. A degree of species specificity was noted in that human TNF were more active against human marrow CFU-GM colonies than against mouse marrow CFU-GM colonies. Samples of bone marrow from patients with non-remission myeloid leukemia were set up in the CFU-GM assay and formed the characteristic abnormal growth pattern of large numbers of small sized clusters. These cluster-forming cells were more sensitive to inhibition by TNF than were the CFU-GM colonies and clusters grown from the bone marrow of normal donors. The sensitivity to TNF of colony formation by CFU-GM of patients with acute myelogenous leukemia in partial or complete remission was comparable with that of normal donors. When combinations of TNF and HuIFN were evaluated together, it was noted that TNF (LuKII) or recombinant TNF synergized with natural or recombinant HuIFN-gamma, but not with HuIFN-alpha, to suppress colony formation of CFU-GM, BFU-E, and CFU-GEMM from bone marrow of normal donors at concentrations that had no suppressive effects when molecules were used alone.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

A high-affinity monoclonal antibody (GIF-1) to human gamma-interferon: neutralization of interferon mediated inhibition of retrovirus production and 2'-5' (A) synthetase induction.

An hybridoma clone secreting an IgG1 monoclonal antibody (GIF-1) specific for human gamma-interferon (HuIFN-gamma) has been generated using HAT medium supplemented with insulin (HIAT) at the initial stage of cell fusion. This antibody is capable of neutralizing the antiviral activity of HuIFN-gamma, the ability of HuIFN-gamma to inhibit retroviral replication in RD-114 cells, and the ability of HuIFN-gamma to induce the 2'-5' oligoadenylate (A) synthetase in RD-114 and HeLa cells. Eluate from an immunoaffinity column containing GIF-1 yielded two protein bands of molecular weight of 20 and 25 kd when subjected to SDS-PAGE.

2',5'-Oligoadenylate Synthetase↗
PubMed1985

High affinity binding of 125I-labeled human tumor necrosis factor (LuKII) to specific cell surface receptors.

125I-labeled TNF(LuKII) (tumor necrosis factor) binds specifically to human and mouse cell lines sensitive to the cytotoxic effect of TNF, but not to cells made resistant to TNF. TNF-sensitive cells have cell surface receptors with a high affinity for TNF(LuKII). Mouse TNF competes with TNF(LuKII) for receptor binding. Scatchard analysis of the binding data yielded linear plots and suggests that TNF(LuKII) binds to homogeneous receptor sites. The number of TNF(LuKII) receptors on two TNF-sensitive cell lines is 200-300 per cell and the affinity constant of the receptor for TNF(LuKII) is approximately 1 X 10(-10) M.

Animals↗
PubMed1985

Purification and characterization of a human tumor necrosis factor from the LuKII cell line.

A factor with tumor necrosis factor (TNF) activity produced by the LuKII human lymphoblastoid cell line [designated TNF(LuKII)] was purified sequentially by using controlled-pore glass, lentil lectin-Sepharose, and procion red agarose chromatography, yielding TNF with a specific activity of 1.5 X 10(7) units per mg of protein and an isoelectric point of approximately equal to 6.7. Purified TNF(LuKII) fractionated by NaDodSO4/PAGE under reducing as well as nonreducing conditions was found to contain seven protein bands of Mr 80,000, 70,000, 43,000, 25,000, 23,000, 21,000, and 19,000. The proteins of Mr 80,000 and 70,000 could not be dissociated into lower molecular weight components. Peptide mapping analysis and immunoblotting analysis revealed that the seven protein bands in the purified TNF(LuKII) preparations are related. After fractionation of TNF(LuKII) by NaDodSO4/PAGE under reducing conditions, TNF activity was recovered from the regions of Mr 70,000 and 19,000-25,000. Purified human TNF(LuKII) (i) produces hemorrhagic necrosis of Meth A mouse sarcoma in the standard in vivo mouse TNF assay; (ii) has the same pattern of reactivity as mouse TNF (cytotoxic/cytostatic/no effect) on a panel of human cancer cell lines; and (iii) has its anticellular effect potentiated by interferon, also a feature of mouse TNF.

Animals↗
PubMed1983

Cytophotometric measurement of the cellular DNA content of [3H]thymidine-labelled spheroids. Demonstration that some non-labelled cells have S and G2 DNA content.

Spheroids from the V279-171b and MCa-11 cell lines were incubated continuously for 24 hr in [3H]thymidine for labelling of the outer cells of the viable rim. The spheroids were dispersed into single cells, and the DNA content of photomapped cells was measured by absorption cytophotometry. Autoradiographs were then prepared from which we ascertained cellular labelling. For spheroids of both cell lines, we found a larger proportion of cells with a G0/G1 DNA content among the non-labelled inner spheroid cells than among the labelled outer cells (P less than 0.001). This block of non-labelled spheroid cells in G0/G1 was not a cell cycle perturbation caused by the isotope for the MCa-11 spheroids. Approximately 8% of non labelled MCa-11 spheroid cells had S/G2 DNA content, suggesting that non-cycling cells in spheroids may be blocked in S and G2 as well as in the G0/G1 phase of the cell cycle.

Animals↗
PubMedDate not supplied

Comparison of cellular and whole-animal bioassays for estimation of radiation effects in the polychaete worm Neanthes arenaceodentata (Polychaeta).

The polychaete worm Neanthes arenaceodentata was used in experiments to determine possible relationships between short-term genotoxicity tests and reproductive and lethal consequences of exposure to ionizing radiation. Groups of juvenile N. arenaceodentata received one of four different radiation doses (2, 4, 8, and 16 Gy) to determine dose-effect estimates for chromosomal aberration induction, and groups of both adult and juveniles received one of seven different radiation doses (1, 4, 8.4, 46, 102, 500, and 1000 Gy) to determine dose-effect estimates for reproduction, mortality, and life span. Effects on reproduction and genetic material were observed at the lowest doses and in the same range; detrimental reproductive effects were observed at 1 to 4 Gy, and the frequency of chromosomal aberrations was significantly increased at 2 Gy. Only high doses resulted in acute mortality (greater than 500 Gy) and decreased life span (greater than 100 Gy). Dose-effect estimates for chromosomal aberration induction were dependent on radiation dose and on the stage of the cell cycle at the time of irradiation. Dose-effect estimates for reproduction were dependent on dose and the potential for repopulation of gonadal tissue. It is concluded that short-term genotoxicity test can be predictive of detrimental reproductive effects in those model systems for which basic cell kinetics and reproductive parameters are well known.

Animals↗
PubMedDate not supplied

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