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Biomedical subjects

S P Moore

Publications and source records attributed to S P Moore.

32 records · Page 2Linked to original sources
PubMed1985

Transformation of human cells by DNAs ineffective in transformation of NIH 3T3 cells.

Neonatal human foreskin fibroblasts can be transformed to anchorage-independent growth by transfection with DNAs inefficient in transforming NIH 3T3 cells. Human cells transfected with DNA from GM 1312, a multiple myeloma cell line, or MOLT-4, a permanent lymphoblast line, grow without anchorage at a much higher frequency than do the parental cells and their DNAs can transform human cell recipients to anchorage-independent growth; they have extended but not indefinite life spans and are nontumorigenic. Human fibroblasts are also transformed by DNAs from two multiple myeloma lines that also transform 3T3 cells; however, restriction analysis suggests that different transforming genes in this DNA are acting in the human and murine systems. These results indicate that the human cell transfection system allows detection of transforming genes not effective in the 3T3 system and points out the possibility of detection of additional transforming sequences even in DNAs that do transform murine cells.

Animals↗
PubMed1985

Peripheral calcifying odontogenic cyst (Gorlin cyst).

A case report of a rare peripheral calcifying odontogenic cyst is presented. The clinical, radiographic and histopathologic features of the lesion are discussed, along with the etiology, rate of occurrence and diagnosis.

Child↗
PubMed1983

An SV40 mammalian inductest for putative carcinogens.

This paper describes an in vitro mammalian inductest for putative carcinogens. Several chemical agents were tested using this system which relies on the induction of Simian virus 40 from SV40-transformed hamster kidney cells as an indicator of potential carcinogenic hazard. Aflatoxin B1, sterigmatocystin and aflatoxin G1 were found to be the most efficient inducers in this system followed by the polycyclic hydrocarbons 9,12-dimethylbenzanthracene and benzo[a]pyrene. In principle, this test is similar to a bacterial inductest and the results obtained in the mammalian inductest are compared to those obtained for the same compounds in the bacterial inductest. In addition, SV40 induction is known to occur in response to ultraviolet radiation and ultraviolet radiation plus the photosensitizing drug, 8-methoxypsoralen.

Animals↗
PubMed1982

Action spectrum for the in vitro induction of simian virus 40 by ultraviolet radiation.

A line of simian virus 40-transformed hamster kidney cells was exposed to ultraviolet radiation at eleven different wavelengths in the region 238-302 nm. An action spectrum derived from the resulting exposure-response curves for the induction of simian virus 40 from these cells exhibits a broad peak in the region 260-270 nm suggesting DNA as the major chromophore for this response. This conclusion is consistent with results obtained by other investigators who have noted viral induction by a number of DNA-damaging agents.

Animals↗
PubMed1982

Tumor virus induction and host cell capacity inactivation: possible in vitro tests for photosensitizing chemicals.

The responses of two in vitro mammalian virus-host cell systems to the photosensitizing chemicals proflavine sulfate and 8-methoxypsoralen (8-MOP) in the presence of light are described. Infectious simian virus 40 (SV40) could be induced from SV40-transformed hamster cells by treatment with proflavine plus visible light or 8-MOP plus near UV radiation. The same photosensitizing treatments inactivated the capacity of monkey cells to support the growth of herpes simplex virus. SV40 induction and inactivation of host cell capacity for herpesvirus growth might be useful as screening systems for testing the photosensitizing potential of chemicals. Advantages and disadvantages associated with each system are discussed.

Animals↗
PubMed1979

An effect of cell-culture passage on ultraviolet-enhanced viral reactivation by mammalian cells.

The ability of ultraviolet-irradiated African green monkey kidney cells to reactivate UV-damaged herpes simplex virus was tested over a range of 57 passages (24-81). Several types of controls were employed to minimize daily variations. The results indicate that in this system cells demonstrate an increasing efficiency to reactivate UV-damaged virus until approx. passage 60, followed by a decrease in this ability beyond this passage. Chromosome counts at selected passages revealed no significant change in chromosome number as a function of passage. The mechanism(s) or factor(s) causing this effect are unknown.

Animals↗
PubMedDate not supplied

Biochemical studies of homologous and nonhomologous recombination in human cells.

Purified and partially purified protein fractions from human cells have been developed that promote homologous and nonhomologous recombination reactions in vitro. Homologous pairing of model DNA substrates is catalyzed by the homologous pairing protein HPP-1 in a magnesium-dependent, ATP-independent reaction that requires stoichiometric amounts of the protein. Addition of the human single-strand binding (SSB) holoprotein complex hRP-A reduces the requirement of HPP-1 in the reaction up to 20-fold. Although the combination of homologous pairing and SSB activities is similar to the bacterial strand-exchange process, the numbers, size, and requirements of the human reaction appear to preclude any detailed comparisons. We have used Z-DNA affinity chromatography as a major step in isolation of human recombination proteins and found that the activities appear to elute as a complex form in approximate multiples of 500 kDa. Associated with the homologous recombination complex is a potent blunt-end ligation activity that appears to mimic the nonhomologous joining functions that are frequently seen following transfection of DNA into mammalian cells. A simple scheme for the association of homologous and nonhomologous recombination functions in mammalian cells is discussed.

Base Sequence↗