Variations in cytotoxicity and mineral content between respirable mine dusts from the Belgian, British, French and German coalfields.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
H Daniel
Publications and source records attributed to H Daniel.
In vitro perfusion technique for investigations on the intestinal transport of water soluble substances.
A new method for the in vitro perfusion of isolated intestinal segments of laboratory animals is described. Everted intestinal segments are used in an "open perfusion system," and are incubated in a buffer solution containing the substrate to be absorbed as a radiolabeled compound. The solutes absorbed are removed from the serosal side in a buffer solution that is collected by a fraction collector. The technique permits studies on the mechanism and the kinetics of the intestinal transport of water soluble substances.
Animals↗
Results of silicone oil injection into the vitreous.
The long-therm follow-up of eyes after injection of silicone oil into the vitreous is reported.l The clinical findings, the results of the subjective examination of the retinal function as well as the ERG and the histological findings of the meanwhile enucleated eyes are very discouraging.
Cataract↗
Chemistry, pharmacology, and structure-activity relationships with a new type of imidazolines exerting a specific bradycardic action at a cardiac site.
The reaction of alkyl halides with 2-(arylimino)imidazolidines (I) leads to imidazoline derivatives II, in which the side chain is situated at the bridge nitrogen atom between the phenyl group and the imidazoline ring. The new imidazolines (II) exert a specific bradycardic action at a cardiac site. Syntheses and pharmacology are shown and structure-activity relationships discussed. The results reveal that the imidazoline derivatives (II) represent a class of compounds with a novel type of cardiac action.
Animals↗
Experimental study of pulmonary emphysema in rats exposed to coal dust and papain: effects on the infrastructure and the cell dynamics.
Experimental lesions of emphysema were produced in SPF rats after laryngotracheal injection of papain and coal dust. The infrastructural changes were investigated a different intervals. The lesions observed are progressive, characterized by atrophy and ruptures of the interalveolar septa, and the disappearance of pneumocytes II. Passage through the septa of mineral particles is enhanced and total dust clearance seems to be increased. The results are discussed in the light of alveolar clearance studies using Fe-59 and surface tension measurements on pulmonary washings.
Animals↗
Action of intensive cigarette smoke inhalations on the rat lung. Role of particulate and gaseous cofactors.
The action of high doses of cigarette smoke alone or combined with coal dust or acrolein was investigated in noninbred Sprague-Dawley rats. Inhalation occurred up to six sessions per day (Hamburg machine), the animals being subjected to a treatment with oxygen after each inhalation session to reduce the carbon monoxide level in the blood. The amount of tar found in the lungs depended on the number of inhalation sessions per day rather than on the total number of inhalations. Smoke inhalation caused emphysematous lesions, the extent of which depended on the total dose of smoke inhaled. No lung tumors were observed. Only a hyperplasia of the alveolar lining involving type II alveolar cells and, at a later stage, areas of metaplasia generally limited to the bronchial area were found. The association of coal dust with cigarette smoke did not alter the specific effects of smoke and resulted in effects peculiar to the action of dust: alveolitis of the macrophage type, fibrosis of the reticulin type, limited hyperplasia, and ciliated metaplasia. When smoke was combined with acrolein, the effects due to smoke were not appreciably altered.
Acrolein↗
[Isolation of cytostatically active proteins from seeds of Ricinus communis, Abrus praecatorius and Canavalia ensiformis (author's transl)].
The extraction and isolation of, as yet, uninvestigated antitumor active protein mixtures from the seeds of Abrus praecatorius, Canavalia ensiformis and especially Ricinus communis is reported. By means of membrane ultrafiltration of crude ricin a low-molecular weight protein mixture, Ro 413, could be obtained, which showed, in comparison to ricin-toxin, a reduced toxicity but with the same cytostatic action. An almost complete separation of Ro 413 into the individual components was achieved using preparative disc electrophoresis. Using the same procedures it was also possible to isolate a low-molecular weight protein mixture from the crude extract of Abrus praecatorius beans and to concentrate their various individual components. The characterization, toxicity and cytostatic action of these proteinaceous plant materials are reported.
Animals↗
[Factors influencing the elimination of the migration of inhaled mineral particles (author's transl)].
The reaction of the body to inhaled mineral dust brings into play physiological and pathological mechanisms in which immunological processes may be involved. An analysis is made of phagocytosis by alveolar macrophages, of the transport of dust to the lymphatic system, of dust aggravation in lymphoid tissues on lymph glands and of the resulting lesions. The part played by dust in immunological disturbances is put forward in the cases of tubercular infections, experimental arthritis and tumors.
Animals↗
[Dissolution of the pulmonary collagen of the normal rat by repeated pepsin action].
A non-denaturating method of extracting collagen from Rat lungs was developed. It consists in dissolving the collagen by repeated action of pepsin. Depending on the age of the animal, efficiency values between 50 and 90% are obtained.
Animals↗
[Behaviour of asbestos fibres in the respiratory system as revealed by animal experiments (author's transl)].
By comparing the evolution of chrysotile and amosite fibres in rat lungs, more rapid clearance was found in the case of chrysotile. The rate of chrysotile clearance is strongly influenced by the size factor. The two varieties of asbestos also differ in their chemical behaviour in the lung. The evolution of chrysotile fibers in vivo is characterized by progressive decrease in magnesium content, while silicium retained in the fibre skeleton is practically not eliminated. Transport of fibers from the lungs to the lymph-nodes, the parietal pleura and the diaphragm also differs with the two asbestos varieties. From fibre counts with the electron microscope, chrysotile was more rapidly eliminated from the lungs than amosite. The concentration is higher with amosite in the lymph-nodes, and with chrysotile in the diaphragm. This last result confirms observations made on human lungs.
Animals↗
[Variation in the toxicity of various silicas in relation to the duration of presence in the body].
The toxic effect of two forms of sand on the lung was investigated by tracheal injection in Rats. After a latent period with low toxicity, more and more extensive pulmonary lesions, comparable to typical silicotic lesions, appear progressively. On the basis of some observations, the hypothesis is put forward that the impurities present in the dust have a retardative effect.
Animals↗
[Experimental study in rats to reduce carbon monoxide in the blood induced by cigarette smoke, by inhaling oxygen at atmospheric pressure].
When animals are exposed to cigarette smoke, the concentration of carbon monoxide in blood is rapidly increased, so that intensive inhalation tests cannot be carried out. A simple apparatus is described to expose Rats alternatively to cigarette smoke and to oxygen in order to reduce the concentration of carbon monoxide in the blood. This method makes it possible to increase the daily administration of smoke considerably; nevertheless, under such conditions, lung tumors were not observed.
Animals↗
[Pharmacologically active polymers. 9th communication: retard forms of morphine antagonists (author's transl)].
Acryloyl, methacryloyl, N-vinylcarbamoyl, and methacryloyl-glycyl derivatives of the morphine antagonist (--)-alpha-5,9-dimethyl-2-(3-furylmethyl)-2'-hydroxy-6,7-benzomorphane have been synthesized. The different unsaturated derivatives were copolymerized with appropriate comonomers to yield water-soluble polymers. Pharmacological tests in mice showed a 2--30 fold increase in duration of action in comparison to the free antagonist. The binding of the antagonist to the polymers resulted in a reduced acute toxicity.
Animals↗
Tissue chemical analysis with muonic x rays.
The stopped muon channel at the Clinton P. Anderson Meson Physics Facility was used as a source of muons for studying the elemental composition of tissue via muonic x rays. The x-ray spectra from several types of tissue were used to determine the amounts of carbon, nitrogen, and oxygen present. These determinations agree with the results of more conventional chemical analysis. Muonic x rays offer a noninvasive technique for determining the amounts of the more abundant elements in selected regions of the body.
Animals↗
Two-dimensional visualization of stopping pion distributions.
Explore the source record for details and available documents.
Elementary Particles↗
Letter: Muonic X-rays from healthy dog liver and dog liver with a tumour.
Explore the source record for details and available documents.
Animals↗
Short-and long-term experimental study of the toxicity of coal-mine dust and of some of its constituents.
The toxicity of various minerals (kaolin, muscovite, illite) was compared by tracheal tests on rats to that of reference dusts (quartz, titanium dioxide, coal). These minerals have various degrees of toxicity. Owing to their sometimes very high concentration in the respirable dust, their toxicity should be taken into consideration. In order to define the aggravating role of quartz more accurately, dust inhalation tests were also conducted on rats with coal and a coal-quartz mixture containing about 10% quartz. The difference in the toxicity of these two types of dust which is practically not detectable up to 12 months, then increases progressively after that period. In addition, in rats having inhaled either coal or a quartz-coal mixture for 24 months, there appear tumoral lesions, principally of epidermoid type.
Adenocarcinoma↗
The therapeutic action of aluminium compounds on the development of experimental lesions produced by pure quartz or mixed dust.
The prophylactic and curative effect of aluminium salts administered as aerosols on the development of lung lesions caused by the dust inhalation of quartz, two coal-quartz mixtures with 17% and 8% silica, respectively, and pure coal, was studied experimentally on rats. It appears that the preventive treatment is very efficient either in the case of pure quartz or coal-quartz mixtures. The curation treatment with regard to pure quartz leads to constant lung weight and reduced rate of collagen formation; the effect is the more evident as the silica content of the dust is higher and becomes nil with pure coal. The effectiveness is slightly increased when aerosols at higher concentrations are used, but the difference is not proportional to the dose. Under these experimental conditions, the aerosols used showed no toxicity.
Aerosols↗