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Biomedical subjects

I Müller

Publications and source records attributed to I Müller.

At least 181 records · Page 10Linked to original sources

Aggregation of sponge cells. Function of a lectin in its homologous biological system.

For the first time, the biological role of a lectin in the process of reaggregation of single cells from the same species (marine sponge: Geodia cydonium Jam.) is described. The galactose-specific lectin does not promote aggregation, but prevents the antiaggregation receptor from disaggregating cell clumps. Competition experiments showed that the lectin inactivates the antiaggregation receptor by binding to it, most likely via its terminal galactose residues. The lectin converts reversibly aggregation-deficient cells (carrying functional cell membrane-bound antiaggregation receptor molecules) to aggregation-susceptible cells.

Animals↗

Aggregation of sponge cells. XX. Self-aggregation of the circular proteid particle.

In the extracellular space of the tissue of the sponge Geodia cydonium, circular proteid particles are found which carry as subunits the aggregation factor and a series of glycosyltransferases. Using the technique of velocity sucrose gradient centrifugation, the sedimentation coefficient (S020,w) of the particle-monosomes was determined to be 90. By means of the Svedberg equation a molecular weight of 1.3 . 10(8) daltons could be estimated. The monosomes aggregate in the presence of Ca2+ to higher complexes via disomes, trisomes, and pentasomes. The complexes can be redissociated by dodecyl sulfate but not by EDTA. During the Ca2+-mediated self-aggregation, the particles lose their biological activity with respect to their aggregation promoting function.

Animals↗

[Mammography in the diagnosis and treatment of non-puerperal mastitis (author's transl)].

Circumscribed or diffuse non-puerperal mastitis is usually associated with local signs of inflammation. In two-thirds of these cases it is possible to demonstrate the radiological features of mastitis. Mammography is an important diagnostic procedure in the demonstration of acute mastitis and its differentiation from an inflammatory carcinoma; it is also valuable in the control of treatment. The success of intensive antibiotic therapy with recovery of normal appearances in the chest can be observed objectively by mammography. In distinguishing mastitis from an inflammatory carcinoma, radiological evidence of regression under the influence of antibiotics is evidence in favour of mastitis.

Adult↗

[Possibilities and limits for palsied children in the general polytechnical school (author's transl)].

Some children with cerebral palsy attend the ten-form general polytechnical school. To this end, several prerequisites have to be fulfilled and other essential arrangements to be developed in cooperation with specially trained teachers. The learning conditions have to be fitted to the improving abilities of children during the educational process. Factors of influence and cooperation modes are discussed.

Adolescent↗

A correlation between shortened life span and UV-sensitivity in some strains of Saccharomyces cerevisiae.

From a UV-irradiated sample of diploid cells several clones were isolated, which produced cells with a shortened life span. A closer examination of three of these clones showed among other deviations from the wild type a higher sensitivity to UV-irradiation. Three other clones, which were selected from a haploid strains as UV-sensitive mutants, proved to be shortlived as well. In all these strains photoreactivation and liquid holding reactivation were unimpaired. There was no cross-sensitivity to X-irradiation. The correlation between shortened life span and UV-sensitivity is discussed.

Clone Cells↗

Aggregation of sponge cells. XIV. Possible substitution of calcium ions by polycations.

Single cells from the siliceous sponge Geodia cydonium, obtained after chemical dissociation, reaggregate in the presence of the aggregation factor in Ca2+-containing medium to large aggregates. It was found that polyvalent organic cations (polylysine, spermine, spermidine, putrescine) enhance the Ca2+-mediated cell aggregation. In Ca2+-free medium these compounds also cause reaggregation; aggregates of a diameter up to 800 micron are formed within 120 min. Proteins, containing basic groups of amino acid residues have no influence on cell aggregation. Monovalent cations inhibit the reaggregation process. The enhancing effect of polyvalent organic cations on cell aggregation is dependent on the presence of the soluble aggregation factor. From the findings that polycations do not alter the duration of the lag phase (a characteristic of the aggregation factor-mediated Geodia cell reaggregation) and act in cooperation with the aggregation receptor, we assume that the polycations bind between the aggregation factor and the aggregation receptor.

Animals↗

Species-specific aggregation factor in sponges. XIII. Entire and core structure of the large circular proteid particle from Geodia cydonium.

High-molecular weight particles have been isolated from the sponge Geodica cydonium. In the "native" from these particles consist of a spherical center and have 25-30 filaments attached to it. The core structure of the particles is assembled of a central circle and 25 radially-arranged filaments. The core structure is obtained from the entire structure by incubation in a medium, containing a non-ionic detergent and EDTA. The molecular weight of the enitre structure was in the range of 1.4 X 10(9) daltons or more and of the core structure 6.1 x 10(8) daltons. Two functional proteins are released from the "native" particles: the aggregation factor and the sialytransferase.

Animals↗