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Biomedical subjects

R K Dogra

Publications and source records attributed to R K Dogra.

35 records · Page 2Linked to original sources
PubMed1980

Trace elemental analysis of extracted dust from lungs and lymph nodes of domestic animals using X-ray fluorescence technique.

Samples of dust extracted from the lungs and lymph nodes of certain domestic animals from West Bengal, Orissa, Bihar provinces of India were quantitatively analysed using photon excited energy dispersive X-ray fluorescence technique. Thin specimens were prepared for analysis to minimize matrix enhancement and absorption effects. Amongst the various elements analysed, Hg, Fe, Cu, Zn and Pb were found to be present in appreciable amounts. An important finding was the presence of a very high concentration of Hg in extracted dust samples from West Bengal. The significance of the various results obtained in this investigation is discussed.

Animals↗
PubMed1977

Effect of talc injected intravenously in guinea pigs.

The pulmonary angiothrombotic lesions in narcotic addicts attributed to the talc present in drug tablets were studied experimentally in guinea pigs following repeated intravenous administration of a suspension of talc dust (75 mg per animal). In early periods there was a moderate localization of talc particles in the alveolar capillaries of lung, liver and abdominal lymph nodes. The vascular injury in the pulmonary tissue was in the form of mild proliferation of the endothelial cells. In addition, many nodular collections comprising macrophages and lymphocytes developed around such vascular structures. At later periods (150 days) the only significant reaction obtained was moderate thickening of interalveolar septa and the lesions were in no way comparable to the human reports. The significance of these findings has been discussed.

Animals↗
PubMed1976

Experimental manganese lymphadenopathy in guinea pigs.

Experimental manganese lymphadenopathy was produced by guinea pigs by intratracheal inoculation of manganese dioxide (50 mg/300 g body weight) and histopathologic changes in the tracheobronchial lymph nodes were studied up to 180 days. There was slow extracellular transport of manganese dust into the nodes, which did not provoke any significant reaction at early periods. However, at later periods the nodes exhibited a significant increase in the density of dust particles and the reaction consisted of phagocytosis, degeneration of dust laden macrophages, slight proliferation of fibroblasts, together with some reticulinosis corresponding to deposits of dust particles. The significance of these findings have been discussed from the chronic toxicity viewpoint.

Animals↗
PubMed1975

Effect of intratracheal injection of mica dust on the lymph nodes of guinea pigs.

Histopathological changes in the tracheo-bronchial lymph nodes were studied up to 365 days in guinea pigs following intratracheal injection of a suspension of mica dust. In general, the cytotoxic effect provoked by dust was not pronounced as the majority of the swollen dust-laden macrophages retained their normal structure at the termination of the experiment and fibrotic lesions were limited to the formation of thick reticulin fibers. The poor fibrogenic response of mica dust has been attributed to its low cytotoxicity.

Aluminum Silicates↗
PubMed1975

Effect of quartz dust on the lungs of mice.

Intratracheal inoculations of quartz dust (250 mg/kg body weight) of a particle size less than 5 mum were given in mice and pulmonary tissue reactions studied over a period of 210 days. Acute inflammatory reaction in the lung parenchyma was observed at early periods and later the aggregates of dust laden macrophages encountered around bronchi and blood vessels. Towards the termination of the experiment at 210 days the fibrotic reaction comprised chiefly of thick compactly arranged reticulin fibers with few collagen fibers which remained restricted to the peribronchial and perivascular areas. There was no silicotic nodule formation in the parenchyma of the lung. The atypical pulmonary tissue response to quartz dust in mice has been attributed to different tissue reactivity.

Animals↗
PubMed1975

Fibrogenic response in murine lungs to asbestos.

Pulmonary fibrogenic response was investigated in mice following intratracheal inoculation of amosite, anthophylite and tremolite varieties of Indian asbestos and studies were made over a period of 150 days. At early periods all the varieties produced acute inflammatory reaction in the lungs. Thick reticulum fibers were encountered at later periods with amosite, while only thin reticulum fibers developed with anthophyllite or tremolite variety. The formation of asbestos bodies did not take place with any of the asbestos varieties even at 150 days. The deviation in the pulmonary fibrogenic response in mice has been attributed to species difference.

Acute Disease↗
PubMed1975

A study of the age factor in experimental silicosis in rats.

In order to study the progress of pulmonary silicosis in rats of different ages, intratracheal injections of (50 mg/150 g body weight) quartz dust of particle size less than 5 mu were given as a single dose and studies were made over a period of 180 days. The pulmonary macrophage reaction and phagocytosis in the younger age group of rats was different from that in the older animals at 30 days postinoculation. The formation of silicotic nodules was delayed in the younger animals. They consisted of thick reticulin fibers and some collagen fibers; in the older group of rats large silicotic nodules with dense collagination developed towards the termination of the experiment (180 days). The present results indicate a possible direct relationship between age and the development of experimental pulmonary silicosis in rats.

Age Factors↗
PubMedDate not supplied

An evaluation of the environmental implications of petroleum refinery emissions by multielemental neutron activation analysis of rumen fluid ash of buffaloes.

In order to study environmental pollution in and around a petroleum refinery complex, a multielemental instrumental neutron activation analysis (INAA) method was used to assay concentrations of As, Ba, Br, Cl, Co, Cr, Cs, Cu, Fe, Hg, La, Mn, Mo, K, Na, P, Sc, Rb, Se, Sr, W and Zn in the rumen fluid ash samples of buffaloes from the vicinity of the refinery. Corresponding samples from a control area 300 km away from the refinery were analysed. Standard Reference Materials, Bovine liver (SRM 1577a), Oyster tissue (SRM 1566a) and Animal bone (CRM H-5) were also analysed for quality control. Samples were irradiated with thermal neutrons at 10(12)-10(13) n cm-2 s-1 and counted by high-resolution gamma spectrometry. Mean elemental concentrations of As, Ba, Br, Cr, Hg and Fe were found to be enhanced, whereas those of Na, K, Cl, Cu, Mn and P were depleted in samples from the vicinity of the refinery complex compared to controls. The environmental implications of anomalous elemental concentrations are discussed.

Animals↗