Biomedical subjects
Publications and source records attributed to U Lindequist.
Extracts of the culture medium from the marine fungus Corollospora maritima exhibited concentration dependent antibacterial activity against Staphylococcus aureus and other microorganisms. Bioactivity-guided fractionation and purification afforded the new isobenzofuranone or phthalid type compound corollosporine.
The influence of three compounds of the essential oil of Chamomilla recutita (L.) Rauschert on the protamine sulphate-provoked degranulation of mast cells from Lewis-1a rats was investigated. The effect was determined by measuring histamine liberation fluorometrically. Chamazulene and (-)-alpha-bisabolol had no distinct effects. The en-yne dicycloether partly inhibited the degranulation in concentrations above 10(-4) M.
Aqueous extracts of 27 basidiomycetes were investigated for their ability to inhibit the activity of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The extracts of 5 fungi inhibited both, ACE and NEP activity, another 18 extracts showed inhibition of the NEP activity whereas only 1 basidiomycete inhibited the ACE activity exclusively. The IC50 values for the ACE inhibition are rather high (between 200 and 1500 micrograms/ml) in comparison to the IC50 of the NEP inhibition (between 40 and 2000 micrograms/ml). These results indicate that the basidiomycetes investigated seem to have a higher potential for the inhibition of the activity of NEP than of ACE. In general, basidiomycetes are a new source for inhibitors of metalloendopeptidases. Resulting from the isolation and characterization of these compounds new leading structures are expectable.
The effects of two phenolic compounds, hispolon and hispidin isolated from fruit bodies of the basidiomycete Inonotus hispidus (Bull. ex Fr.) Karst, were investigated on the chemiluminescence response by LPS- or zymosan-activated human mononuclear cells (MNC) and on the concanavalin A-induced proliferation of spleen lymphocytes of mouse in vitro. Both compounds showed inhibitory activity in the chemiluminescence-test with an IC50 (the concentration of test compound causing 50% effect) ranging from 4.4 to 4.6 micrograms/ml (20.3 to 21.2 microM) for hispolon and < 0.1 to 1.5 micrograms/ml (from < 0.4 microM to 6.0 microM) for hispidin. Antiproliferative effects have been achieved in the lymphocyte transformation test (LTT) by hispolon with an IC50 of 3.4 micrograms/ml (15.5 microM).
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In the methanolic extract of Meripilus giganteus a mixture of saturated and unsaturated fatty acids (among them palmitic, oleic and linoleic acid) and ergosterol peroxide were identified as immunosuppressive components. Furthermore a homologous series of straight-chained saturated hydrocarbons with 22 to 26 and 29 to 32 C-atoms could be found.
Explore the source record for details and available documents.
Tricholoma populinum is widely distributed in Europe and North America. In the GDR 110 localities have been recorded, ranging from sea level to 470 m s.m. It is associated with many Populus spp. on acidic and neutral ground; its frequency has locally increased by recultivation of slap-dumps and waste land with poplars. Maximum of fructification is in the first decade of October. Investigations, stimulated by empiric observations on immunosuppressive effects of the mushroom in allergic diseases of man, lead to isolation of ergosterol peroxide as one substance responsible for these effects.
Explore the source record for details and available documents.
Dry powders or extracts of the fruit bodies of Tricholoma populinum given per as or injected intraperitoneally respectively caused a suppression of the number of plaque forming cells of mice as shown by the hemolysis-plaque-assay. Extracts of the fungi inhibited above that the incorporation of 3H-thymidine into mitogen-stimulated human lymphocytes as observed in the lymphocyte transformation test and retarded the proliferation of cultivated bovine aortic endothelial cells.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The relative myosin content of aortic cells of newborn rats was estimated cytophotometrically in the course of cultivation using indirect immunofluorescence staining. It should be shown that the average myosin content of the cell population and the number of cells with high myosin content is greatly enhanced when confluency of the cells is reached and proliferation stops. Following the amount of 14C-labelled leucine incorporated in immunoprecipitated myosin during the same period we found that increasing myosin content of the cells results from an enhanced rate of myosin biosynthesis.
Smooth muscle myosin was demonstrated in cryostat sections, isolated and cell cultures from aortas of newborn rats by the method of indirect immunofluorescence. The content of myosin in the cells was compared by measuring the fluorescence intensity of single cells. Well differentiated smooth muscle cells present in suspensions of the whole aorta and of the aortic media as well as in aortic cell cultures, are shown to have a higher myosin content than fibroblasts of adventitia and smooth muscle cells with a lower degree of differentiation.