Biomedical subjects

D L Lundgren

Publications and source records attributed to D L Lundgren.

At least 37 records · Page 2Linked to original sources

PubMed1984

Biokinetics of inhaled 244Cm oxide in the rat: effect of heat treatment at 1150 degrees C.

A study was conducted in rats to determine solubility and subsequent metabolism of an inhaled aerosol of curium treated at high temperatures. Young adult Fischer-344 rats received a single inhalation exposure to one of three monodisperse aerosols of 244Cm2O3 (0.70, 1.3, or 2.6 micron activity median aerodynamic diameter) heat-treated at 1150 degrees C. Animals were maintained individually in metabolism cages for excreta collection and serially sacrificed in groups of two male and two female rats from 2 to 33 days after inhalation exposure. Additionally an injection study with curium citrate was done to define the systemic behavior of Cm in this rat model. The in vivo solubility was inversely related to the aerosol particle size. The relationship of the results of this study to results from other experimental inhalation studies with curium oxide aerosols is discussed, as is the relevance to bioassay interpretation and risk assessment in man.

Aerosols↗

PubMed1983

Effects of the single or repeated inhalation exposure of Syrian hamsters to aerosols of 239PuO2.

Male Syrian hamsters were scheduled to be exposed by inhalation approximately every 60 days for 1 year (7 exposures) to aerosols of 239PuO2 beginning at 84 days of age. Other hamsters were exposed once when 84 or 320 days of age. Plutonium-239 deposited in the lungs by the repeated inhalation exposures was cleared from the lungs at a rate similar to that following a single inhalation exposure. The incidence of radiation pneumonitis, bronchiolar epithelial hyperplasia, and alveolar squamous metaplasia were the only lesions that were related to radiation dose. Only two primary lung tumours were found among the hamsters exposed to 239PuO2. No primary lung tumours were found in the control hamsters. It was concluded that the incidence of lung tumours was not increased by the protraction of the alpha radiation dose to the lungs from repeated inhalation exposure.

Aerosols↗

PubMed1983

Respiratory infection of cyclophosphamide-treated mice with Pseudomonas aeruginosa.

The dose of cyclophosphamide that permits the colonization of the nasopharynx with Pseudomonas aeruginosa and the survival of the animal was determined in mice. This dose, 100 mg/kg of cyclophosphamide, allowed P aeruginosa to colonize but not invade mouse nasal epithelium. Mice treated with 100 mg/kg cyclophosphamide were exposed to aerosol of 35S-labeled P aeruginosa to study clearance. Results indicated that this dose of cyclophosphamide suppressed both the pulmonary clearance of viable P aeruginosa (in situ killing) and the clearance of radiolabeled P aeruginosa (mechanical clearance).

Animals↗

PubMed1982

Repeated inhalation exposure of Beagle dogs to 239PuO2: retention and translocation.

Whole-body retention and distribution of 239Pu in selected tissues of Beagle dogs were determined after a series of two or four inhalation exposures to 239PuO2. Exposures were made at half-year intervals with alveolar depositions of about 150 nCi per exposure. Data are reported on dogs followed for one and two years after the first exposure. The plutonium was found to be extremely insoluble; 2-3% of the amount deposited in the alveolar region translocated to tracheobronchial lymph nodes and less than 0.1% translocated to other tissues. The whole-body retention, when compared to retention of 239Pu following a single exposure, supported the hypothesis that each exposure was retained independently with the same retention characteristics. This is in agreement with results reported by other investigators for one human repeatedly exposed by inhalation to low levels of aerosols containing plutonium-uranium fuels.

Aerosols↗

PubMed1982