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Biomedical subjects

R Masse

Publications and source records attributed to R Masse.

At least 127 records · Page 7Linked 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

[Dynamic comparative study of the intraalveolar cell population after intratracheal injection of beryllium hydroxide and aluminum hydroxide in the rat].

A sequential quantitative analysis of free alveolar cells was performed on S.P.F. rats after intratracheal injection of Be (OH)2 and Al (OH)3. The induced lesions were entirely restored 20 days after the initial injection. Beryllium hydroxide inhibited DNA synthesis in the free alveolar macrophages and the transeptal cellular flow could be evidenced. Aluminium hydroxide increased the number of free cells without inhibiting DNA synthesis. Quantitative variations of polymorphonuclears, lymphocytes and macrophages were correlated with changes in the alveolar environment. A strong direct correlation between the number of lymphocytes and DNA synthetizing macrophages was shown out. This reaction was not observed in beryllium treated rats.

Aluminum↗
PubMed1975

[Quantitative evaluation and homeostasis of alveolar macrophage populations].

The rat's alveolar macrophage population is a biological constant which significantly varies according to the season, the strain and the bacteriological state,in healthy animals. The percent rate of excreted macrophages remains constant in spite of the physiological changes of the total population variation. This rate is close to 3,5 %. So, the variations of the population are due to the changes in cell arrival. The possible different sources of alveolar macrophages are analysed and evaluated. The direct monocyte source is not sufficient to insure the stability of this population. Division of intra alveolar macrophage enables homeostasis. In pathological conditions, variations of cell populations result from two effects : reduction of excretion, positive or negative changes in cellular influx.

Aerosols↗
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↗