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Biomedical subjects

M Balls

Publications and source records attributed to M Balls.

112 records · Page 7Linked to original sources

Validation of alternative toxicity test systems: lessons learned and to be learned.

Validation in the context of in vitro toxicity tests is defined, and various aspects of the validation process are discussed, including the design and conduct of interlaboratory validation schemes; the selection of tests, participating laboratories, and test chemicals; the selection and use of in vivo data; in vivo/in vitro data comparison; the question of "false" results; in vitro cytotoxicity as a predictor of actual lethal toxicity; and the validation of alternatives to the Draize eye irritancy tests. It is concluded that a thorough reevaluation of current practice is essential if the promise and potential of nonanimal toxicity tests are to be fully realized and if valid alternative tests acceptable to regulatory agencies are to be developed.

Animals↗

Comparison of the in vitro cytotoxicities and acute in vivo toxicities of 59 chemicals.

The in vitro cytotoxicities of 59 chemicals, expressed as ID50 values (i.e., concentrations of test chemicals that reduced the final cellular protein content of test cultures by 50% in comparison with appropriate solvent control cultures) and obtained using murine 3T3-L1 cells and the FRAME kenacid blue method, have been compared with rat oral and mouse intraperitoneal (ip) LD50 values. A better in vivo/in vitro correlation was obtained for the 59 chemicals with mouse ip LD50 values (r = .80) than with rat oral LD50 values (r = .76), but the best in vivo/in vitro correlation was found when the most toxic of the rat and mouse values were used in the comparison (r = .81).

Administration, Oral↗

Assessment of two alternative methods for predicting the in vivo toxicities of metallic compounds.

The FRAME in vitro cytotoxicity assay and a physicochemical parameter for metal ions (i.e., "softness," sigma p) were assessed for their ability to predict the in vivo acute toxicities of 52 metallic compounds. The in vitro assay was found to be more useful, since it measures the toxicity of the whole compound, as does the in vivo method. The softness parameter applies to the metal ion only, so it cannot be used to predict the toxicity of compounds containing relatively nontoxic metal ions and toxic anions (e.g., potassium fluoride). The in vitro toxicity values (expressed as ID50 values, i.e., concentrations of test chemicals that reduced the final cellular protein content of test cultures by 50% in comparison with appropriate solvent control cultures) correlated better with mouse ip LD50 values than with rat oral LD50 values.

Animals↗

Chimpanzees in AIDS research: a biomedical and bioethical perspective.

The present article represents a consensus view of the appropriate utilization of chimpanzees in AIDS research arrived at as a result of a meeting of a group of scientists involved in AIDS research with chimpanzees and bioethicists. The paper considers which types of studies are scientifically justifiable in this species, the conditions under which such studies should be carried out, and the conditions which should be encouraged for post-experimental retirement of these animals.

Acquired Immunodeficiency Syndrome↗