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Biomedical subjects

J C Nenot

Publications and source records attributed to J C Nenot.

16 recordsLinked to original sources
PubMed1982

[The relationship between radiation doses and their effects].

Dose-effect relationships have been developed both for the biological effects studied by Radiobiology and the long-term pathological effects (malignant diseases) studied by Radiation Protection. The former approach chiefly considers the primary biological injuries at the cellular level, and the relationship between the dependent variable characteristic of the effect and the dose--an independent variable--has an explanatory meaning. The parameters associated to the independent variable have a biophysical signification and fit into a model of the action of ionizing radiations. In the latter approach, the relationship is pragmatic and the previous parameters are just the result of a curve-fitting procedure realized on experimental or human data. The biophysical models have led to a general formulation associating a linear term to a quadratic term both of them weighted by an exponential term describing cellular killing at the highest doses. To a certain extent the curves obtained for leukemias, bronchopulmonary and breast cancers prove the validity of the pragmatic model.

Animals↗
PubMed1975

Metabolic and dosimetric studies after inhalation of 227Th in rats with regard to the risk of lung and bone tumors.

227Th (alpha-emitter, half-life 18.7 days) was inhaled by rats from solution in nitrate form. Organ doses were calculated after whole body measurements and measuring of activity concentrations in the organs over a longer incorporation period. An initial deposition of 100 nCi 227Th in the lung resulted in mean total doses of 150 rad in lung and 36 rad in bone. The data for kidney and liver were 2 rad and 0.1 rad, respectively. For long-term experiments two dosages were applied to two groups of animals with mean values of 900 rad and 300 rad in the lung. The consequences for lung and bone tumor induction are discussed.

Animals↗