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Biomedical subjects

J Bruch

Publications and source records attributed to J Bruch.

70 records · Page 4Linked to original sources
PubMed1976

[Behaviour of the lung as an organ of absorption and reaction when air-borne contaminants are inhaled (author's transl)].

The pulmonary resorption of air pollutants constitute a significant factor for the whole body burden of men, as can be shown for lead, SO2 and CO. Particle size as well as water and lipid solubility of the noxious agents are important variables for the extent of the interaction with the pulmonary surface. Main objects for the inhalative pollutants are the bronchioli terminales and the respiratory epithel. The electronmicroscopic investigations point out a specific irritability of these structures as far as lead, oxydants and fibers are concerned. Comparatively low concentrations of the agents produce, in chronic exposure, changes in the caliber of the small airways and widening of the ductus alveolares and the alveoli. In addition to the reduction of the inner lungsurface one observes a thickening of the diffusion barrier in loco through some harmful substances. A number of pollutants influence a primary cytotoxic effect on alveolar macrophages. Thereby the bacterial infection resistance of the lung is reduced; moreover the phagozytes play an important part for the detoxification of carcinogenic carbohydrates. Hence the lung functions as a resorptionorgan, as a protectionorgan and as an object of damage for various air pollutants.

Absorption↗
PubMed1975

Pathogenicity to animals of fine dusts from Ruhr mines.

Twelve different groups of fine mine dusts were examined for their in vivo aggressivity by intraperitoneal injection. Twelve months after injection of the dust, quantitative morphometric analysis of the lymph nodes was carried out to determine (a) the extent of the typical quartz reaction, (b) the in vivo cytotoxicity, (c) the size of the lymph nodes. Different fine dusts showed significant variations in parameter (a) and (c). In the second part of the investigation, the results of the lymph node tests and of in vitro cytotoxicity tests, and also the quartz contents of the dusts were fed into a data matrix and subjected to correlation analysis and principal component analysis. The following hypotheses were arrived at to explain the effect of the fine dust in vivo: (1) The amount of fine dust which penetrates into the lymph nodes is dependent on its in vitro cytotoxicity (Factor A). This is not related to the quartz content of the dust and is not inhibited by PVNO. (2) The specific fibrogenic activity of the fine dust within the lymph node is primarily dependent on its quartz content (Factor B). It appears that this effect is inhibited by PVNO. (3) The total fibrogenic activity depends on a combination of Factor A and B.

Anthracosilicosis↗
PubMed1974

Response of cell cultures to asbestos fibers.

The reaction of macrophages to asbestos and glass fibers was studied by light and by electron microscopy. Measurements were made of LDH release, staining with erythrosine B, and lactate production. Size and shape of asbestos fibers were found to have more effect than the physicochemical properties of the surface. Long fibers resulted in a protracted pathogenic but no acute cytotoxic effect.

Asbestos↗
PubMedDate not supplied

Advantages of Sirius Red staining for quantitative morphometric collagen measurements in lungs.

Sirius Red staining is presented as a method for collagen determination, enabling quantitative morphometric measurements to be performed in locally defined tissue areas. The advantage of this method is especially shown for alveolar lung tissue. By excluding the bronchial areas in the tissue sections, the differences in the degree of fibrosis proved to be more discrete after different loads of quartz dust than by any other method. The difference of 12 micrograms collagen measured colorimetrically represented a 1.2-fold increase. The collagen measured in the alveolar tissue by the morphometric method rose from 9.8 to 28.6%. This is a 2.9-fold increase, underlining the vast improvement in sensitivity. Thus, this method is specifically suitable for the evaluation of very small fibrotic lesions. The quartz doses given are particularly low compared to most other investigations. Histologic lung and lymph node sections from female Wistar rats injected intratracheally with differing quantities of quartz dust (0.03, 0.1, 0.5, 1.75 mg) were stained with Sirius Red, and the collagen fibers measured with a quantitative image analysis. The results for lymph nodes using different methods (wet weight determination, quantitative measurement of quartz typical areas, colorimetric and morphometric collagen determination) showed a high correlation at the different doses. This showed that the morphometric method is suitable for the quantitative measurement of collagen. Corresponding results were also found in the comparative lung tissue measurements (colorimetric and morphometric collagen determination). However, the morphometric method has the decisive advantage that measurements can be restricted to defined tissue areas and do not destroy the section.

Animals↗