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Biomedical subjects

R Masse

Publications and source records attributed to R Masse.

At least 73 records · Page 4Linked to original sources
PubMed1987

Parallel increase of plasma fibronectin and perchlorosoluble serum glycoproteins in radiation-induced lung damage.

A study of the behavior of plasma fibronectin during a radiation-induced inflammatory lung reaction was carried out. Rats were exposed to a single homogenous thoracic irradiation of 15 Gy from a 60Co gamma source. Perchlorosoluble glycoproteins were determined (as sialic acid) as well as plasma fibronectin at 2, 8, 27, 60 and 120 days after irradiation. A parallel increase of the perchlorosoluble glycoproteins and plasma fibronectin was found. Morphological and histological studies of the irradiated lungs showed a predominating endothelial cell injury in the lung microcapillaries. The parallel increase of plasma fibronectin and perchlorosoluble serum glycoproteins suggests that plasma fibronectin can be considered as an acute phase reactant. Its early increase may be the result of the inflammatory reaction and endothelial injury induced by the radiation.

Animals↗
PubMed1986

Activation of rat alveolar macrophages and protection against i.v. injected tumor cells by intratracheal administration of trehalose dimycolate.

Intratracheal (i.t.) administration of trehalose dimycolate (TDM) in saline as liposomes induces a transient inflammatory effect. Limited granulomas appeared in some peribronchial areas but most subsided after a few weeks. The alveolar macrophages were activated as judged by their cytostatic activity against the syngeneic P77 fibrohistiocytoma 3 days after administration of 0.2 mg TDM. The NK activity of the lymphocytes of the lung microcirculation did not increase and diminished slightly between 1 and 3 days after TDM administration, thus suggesting that macrophages might be the main effector cells responding to TDM. Repeated i.t. TDM administration protected rats against the development of colonies in the lung after i.v. injection of 5 X 10(5) P77 cells. The survival of the rats was significantly increased. Thus, in this system, a relationship exists between activation of alveolar macrophages and protection against colonies arising from i.v. injected tumor cells.

Animals↗
PubMed1986

Transfer of Np(V) nitrate from gastrointestinal segments of the adult rat.

The transfer of soluble Np(V) nitrate was measured in gastrointestinal segments from adult rats by two procedures: instillation, in segments in which the physico-chemical form of Np might be modified by gastrointestinal factors; and perfusion, in segments in which the luminal state of Np remains constant. These assays allowed accurate measurement of the Np(V) transferred from the intestine to the whole body. The amount measured was proportional to segment length and to the duration of the experiments, which lasted for periods of 0.25 to 2 h. Under these experimental conditions, hourly transfer values were about 2 percent, both per millilitre of Np(V) solution instilled and per 10 cm of jejunum perfused. This flux is very much greater than that which may be deduced from studies in which Np was gavaged into intact rats. Intestinal transfer of Np was constant for Np concentrations ranging from 5 X 10(-12) M to 1 X 10-4) M. Raising the concentration of Np(V) to more than 1 X 10(-4) M reduced its intestinal transfer. Addition of Fe(II) also reduced it. The small intestine was the main site of Np(V) absorption, since the transfer from instilled jejunum was about 20 times that observed from the stomach, and no difference was noted between jejunal and duodenal transfer.

Animals↗
PubMed1986

Gastrointestinal absorption of neptunium in primates: effect of ingested mass, diet, and fasting.

Absorption and retention of neptunium were determined in baboons after intragastric administration of neptunium nitrate solutions at pH 1. The effects of mass, diet, and fasting on absorption were studied. At higher mass levels (400-800 micrograms Np/kg), absorption was about 1%; at lower mass intakes (0.0009-0.005 micrograms Np/kg), absorption was reduced by 10- to 20-fold. The addition of an oxidizing agent (Fe3+) increased gastrointestinal absorption and supported the hypothesis of a reduction of Np (V) when loss masses were ingested. Diets depleted of or enriched with hydroxy acids did not modify retention of neptunium but increased urinary excretion with increasing hydroxy acid content. The diet enriched with milk components reduced absorption by a factor of 5. Potatoes increased absorption and retention by a factor 5, not necessarily due to the effect of phytate. Fasting for 12 or 24 h increased retention and absorption by factors of about 3 and 10, respectively. Data obtained in baboons when low masses of neptunium were administered suggest that the f1 factor used by ICRP should be decreased. However, fasting as encountered in certain nutritional habits is a factor to be taken into consideration.

Animals↗
PubMed1985

[Autohistoradiographic study of the pulmonary retention of almitrine bismesylate].

The histo-autoradiographic distribution of labelled Almitrine was quantitatively assessed on semi-fine cuts of rat lung. The experimental set-up consisted of an isolated heart-lung preparation, perfused for two hours with homologous blood containing 10 microCi per ml of H3 almitrine (990 mCi/mM) et 0.1 microCi per ml of C14 almitrine (9.9 mCi/MM). Sequential histological biopsies were made. There was an apparent heterogeneous radioactivity of the tissues overall with no observed increase in fixation with perfusion time (v.i.). Nevertheless the auto-radiograph enabled this conclusion to be rectified by revealing the cause of the heterogeneity, the embolisation of micro-aggregates of the labelled product. After correction was made for this factor the scattering of the fixed radioactivity in the samples was weak. The localisation of the labelled product showed a good stability for the fixed marker in the tissues, and identified the distribution of the tracers H3 and C14, a preferential fixation by alveolar macrophages, type-2 pneumocytes, Clara cells and adipocytes. A remarkable fixation was noted in the cardiac fibres of the pulmonary veins. Amongst the cells of the bronchi, the mucus cells were notably active for the fixation of Almitrine. There was no detectable fixation associated with the nervous tissues and the neuro-epithelial body was not labelled. A sequential analysis showed that only fixation in smooth muscle fibres rose significantly with perfusion time.

Almitrine↗
PubMed1984

Microautoradiography of gamma-emitters: interest of latensification process.

Two techniques of microautoradiography were compared in order to assess their respective values to detect gamma-emitters usually used in nuclear medicine. Grain density microautoradiography (GD MARG) and track microautoradiography (T MARG) were performed on lymphocytes labeled with 99mTc, whose conversion electrons are able to provide a signal in nuclear emulsion. Microautoradiographs are presented, that clearly demonstrate the higher sensitivity, specificity and resolution obtained by T MARG. This technique seems particularly adapted to assess the distribution of gamma-emitters in cells and tissues.

Autoradiography↗
PubMed1984

Multiplicative effect of inhaled plutonium oxide and benzo (a) pyrene on lung carcinogenesis in rats.

This study describes the effect of intratracheal instillations (2 X 5 mg) of benzo(a)pyrene (B(a)P) on lung carcinogenesis in rats which had previously inhaled different levels of 239 plutonium oxide (220, 630, 6300 Bq, initial lung burden). Survival decreased with increasing PuO2 exposure and additional B(a)P exposure. The incidence of malignant lung tumours, adjusted for differences in survival, increased in a dose-related fashion with PuO2 dose and was elevated in the presence of additional B(a)P exposure. A multiplicative relative risk model was found to describe reasonably well the observed joint effect. The practical implications of these findings are discussed.

Administration, Intranasal↗
PubMed1984

Ion microscopy, a method for imaging the distribution of trace elements in the lung.

Analytical ion microscopy, a method of surface microanalysis, is applied to the detection of trace elements in the lung. With this method it is possible to obtain images of the distribution of any element in lung tissue sections with a resolution of 0.5 micron and with very high sensitivity (of an order of magnitude 3 or 4 times greater than with X-ray microanalysis). Under these conditions it is possible to study at the microscopic level the penetration into the lung cells of mineral materials administered in physiological amounts. The images are formed by ion microscopy of atoms sputtered as charged particles from the specimen, and these atoms are selected by mass spectrometry. This technique has been applied to the detection of aerosols (diam. less than 1 micron) of rare earths (thulium or cerium chloride), inhaled in very small amounts (20-50 micrograms), in cells from the lung of a rat. Images of the distribution of these elements were obtained in a few seconds or minutes, when X-ray microanalysis gave either a weak signal or none at all. Their behaviour in the lung could be easily studied several weeks after the end of the inhalation.

Aerosols↗
PubMed1984

Early cellular and biochemical alveolar responses following intra-tracheal inoculation with low dose of asbestos and quartz.

The study of broncho-alveolar lavage harvested from rats intratracheally dusted with chrysotile (0.5 mg), leached chrysotile (0.5 mg), crocidolite (0.5 mg) and quartz (0.5 and 5 mg) indicated: 1. A cytotoxic lysis of alveolar macrophages in relation to phagocytosis of dust particles in the following decreasing order: quartz, crocidolite, chrysotile. 2. Regarding cell intensity and duration while asbestos, even leached chrysotile, gave merely an early and transient response. This cell recruitment concerned mostly PMN leukocytes and at a less extent alveolar macrophage. 3. Cell recruitment was associated with an increased protein and phospholipids alveolar content. The increase of proteins came probably mostly from an inflammatory serum exudation. However, an increase synthesis of complement C3 and phospholipids is not excluded.

Animals↗
PubMed1984

Comparison of the induction of pulmonary neoplasms in Sprague-Dawley rats by fission neutrons and radon daughters.

Pulmonary carcinomas were recorded in a life-span experiment of male Sprague-Dawley rats exposed to fission neutrons. Mortality-corrected prevalences are obtained by the method of isotonic regression. In a second part of the paper a comparison is made with data obtained earlier for radon-daughter inhalations in the same strain of rats. A simultaneous maximum likelihood analysis is applied jointly to all experimental groups from the radon inhalation and the fission neutron study. The dependence of the resulting coefficients for the different groups on absorbed dose or inhalation dose permits a derivation of equivalence ratios. At low doses the equivalence ratio is 3 WLM (working level months) of radon-daughter exposure to 1 mGy of fission neutrons. At higher doses the equivalence ratio decreases. The neutron data are also utilized to derive mortality-corrected lifetime incidences of pulmonary carcinomas in the exposed animals. At low doses the relation is consistent with linearity, but sublinearity (dose exponent less than 1) cannot be excluded.

Animals↗
PubMed1983

Incidence of various types of thoracic malignancy induced in rats by intrapleural injection of 2 mg of various mineral dusts after inhalation of 222Ra.

After inhalation of 222Ra at equilibrium with radon daughters, male Sprague-Dawley rats were inoculated intrapleurally with 2 mg of unleached or acid-leached asbestos fibres or glass fibres or quartz. The additive co-carcinogenic effects of this type of insult were demonstrated by the increased incidence of malignant thoracic tumours. In rats given mineral materials, bronchopulmonary carcinomas and mixed carcinomas were observed, as well as typical mesotheliomas and combined pulmonary pleural tumours, whereas in control rats inhaling radon alone, only bronchopulmonary carcinomas occurred. No significant differences in tumour incidence were observed between the groups of animals given the different types of dusts, but statistically significant differences were noted in survival times, according to the histological type of tumour. The co-carcinogenic effects of an insult of the pleura by mineral dusts following inhalation of radon are discussed in relation to a possible tumour-promoting effect by these agents.

Animals↗
PubMed1983

Metabolism of plutonium introduced as Tri-N-Butylphosphate complex in the rat and removal attempts by DTPA.

The metabolism of plutonium introduced as the Pu-Tri-N-Butylphosphate complex (Pu-TBP) was studied in rats after inhalation, injection and ingestion. Early translocation and distribution of 239Pu in organs for 30-400 days after inhalation exposure are presented. The tracheobronchial clearance was impaired at early times, followed from about one week by clearance from the deep lung as characterized by a half time of 100 days. Skeleton was the main organ for deposition of the transferable fraction. The bone burden reached a plateau value of 10% of Initial Lung Burden (ILB) at 50 days after inhalation, while retention in liver reached 2% of ILB at 50 days and decreased to 0.3% by 1 yr after inhalation. Thirty days after intramuscular injection, translocated plutonium (15% of injected activity) resulted in a skeletal deposit that was 17.5 times higher than the deposit in the liver. By both routes, inhalation and intramuscular injection, 239Pu was transported in the blood as a Pu-transferrin complex. However, therapy with 30 mumol . kg-1 DTPA was ineffective. This result, together with the magnitude of the skeletal deposit observed, indicate that Pu-TBP follows a specific metabolic pathway that results in a Pu-transferrin complex that is more stable than the complexes described after Pu nitrate or citrate contamination. Lastly, absorption of Pu-TBP from the gut was poor, reaching 0.015% of the Pu given by gavage, a value not significantly different from the values assumed by ICRP 30 for class W compounds.

Administration, Oral↗
PubMed1983

A study of familial lupus erythematosus-like disease and hereditary angio-oedema treated with danazol.

Immunological and genetic studies were performed in a family in which the mother and five siblings had hereditary angio-oedema (HAE). LE cells, antinuclear factors, antibodies to double-stranded DNA and positive direct Coombs' test were not found in any of the subjects. One female sibling had a lupus erythematosus-like illness with skin lesions of the face which responded to danazol treatment. Laboratory evidence of HAE was obtained in the entire kindred and all the siblings shared HLA haplotype AIB7 inherited from the deceased mother.

Adolescent↗