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Biomedical subjects

J Lafuma

Publications and source records attributed to J Lafuma.

At least 55 records · Page 3Linked to original sources
PubMed1975

[Electron microscopic identification of thymidine-incorporating cells in a population with a low turnover rate. Application to deep lung cells].

Many cells difficult to identify by photon microscopy were identified by using serial thin and semithin epoxy section. This procedure made it possible to carry out significant statistical analysis on a restricted number of sections. When applied to the study of cell renewal in the deep lung, each cellular proliferation could be quantified.

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↗
PubMed1975

239PuO2 aerosol inhalation with emphasis on pulmonary connective tissue modifications.

Inhalation studies were undertaken in which plutonium dioxide (239PuO2) was administered to either unanesthetized Wistar rats or anaesthetized baboons. In both groups of animals some deaths occurred from acute lung damage resulting from cell necrosis particularly to vascular tissue followed by alveolar oedema. At later stages, marked interstitial pneumonitis and interstitial fibrosis occurred and deaths resulted from respiratory insufficiency preceded by high arterial blood pCO2 and low pO2. In rats as many as 50% of the animals finally developed lung neoplasms by only two such tumours were found in baboons. Attempts were made to correlate biochemical parameters with observed tissue damage and animal mortality.

Aerosols↗
PubMed1975

Therapeutic effect of pulmonary lavage in vivo after inhalation of insoluble radioactive particles.

Pulmonary lavages in vivo after inhalation of 239PuO2 were conducted using more than 100 baboons. Results have permitted the definition of optimal conditions of lavage. It was shown that both lungs can be lavaged during the same sitting, and that the procedure could be applied up to 3 months after exposure with a significant efficiency. The treatment must be repeated several times because only 10-15% of the lung burden is removed during one sitting. With a schedule of ten bilateral bronchopulmonary lavages (at days 1, 4, 9, then once a week) 58% of initial lung burden is removed. In addition, up to 30% is removed by an accelerated natural clearance after lavage. No chronic histological or physiological alterations of the lungs were observed after this procedure, which seems an efficient therapy for removing inhaled insoluble radionuclides.

Animals↗