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M Finck

Publications and source records attributed to M Finck.

10 recordsLinked to original sources
PubMed2006

Simulation of nasal flow by lattice Boltzmann methods.

The lattice Boltzmann method is used to calculate the incompressible, viscous flow of air through a model of a nasal cavity, used in experiments. Computations are performed for steady flows at the inspiration and expiration phase of nose breathing. Computed pressure distributions and friction coefficients compare well with Navier-Stokes solutions from a finite-volume method on structured, curvilinear grids. The comparison with conventional Navier-Stokes solvers shows several advantages of the lattice Boltzmann method in particular for bio-medical flow problems. These are the fast grid generation, the simple, granular algorithm, suited for efficient parallelization and the high flexibility for implementing complex boundary conditions and additional transport equations. Lattice Boltzmann methods are therefore efficient candidates for fast flow predictions in the frame of computer-aided rhino-surgery.

Computer Simulation↗
PubMed2005

[Development of a walking stage test (PWT) for the elderly].

The aim of the project promoted by the federal state of North-Rhine/Westphalia was the development of a field stage test focusing on endurance exercises of elderly people which withstand test-theoretical quality criteria, in particular that of economy. The main objectives were therefore the measurement of individual potential by measuring the heart rate, with simultaneous minimization of health risks and a close link to normal, everyday exercises. The test procedure was supposed to estimate the aerobic endurance of elderly people in order to enable us to give individual training recommendations on walking. In a three-phase procedure (laboratory and field ergometry, test development, and evaluation) with a total of 90 test persons, the individual heart rates and lactate levels were measured in 269 single tests. The findings show that an evaluation of the individual performance capability on the basis of heart rate is possible using a three-stage power walking test (PWT), without requiring maximum strain of the subjects. The PWT can therefore be seen as a diagnostic instrument available for the age group of the 60-80 year-olds, supplying a default for an individual strain dosage for walking. The test is accomplished independently of the respective age of the subjects and the result is an individual training plan for walking on the basis of an estimate of personal endurance. Developed as a staged test, the three levels requiring a 400 m walk on each level at different speeds, all the test requires is the measurement of the heart rate at the end of each level. The validity of the common guides for the planning of training by heart rate for systematic endurance training (walking) is thereby improved enabling a more individual training recommendation.

Aged↗
PubMed1998

A small protein (Ags1p) and the Pho80p-Pho85p kinase complex contribute to aminoglycoside antibiotic resistance of the yeast Saccharomyces cerevisiae.

We identified the AGS1 and AGS3 genes by their ability to partially complement an ags mutant (RC1707) which is supersensitive to various aminoglycoside antibiotics (J. F. Ernst and R. K. Chan, J. Bacteriol. 163:8-14, 1985). AGS1 is located in proximity to the centromere of chromosome III and encodes a small protein of 88 amino acids. The size of the AGS1 transcript, which in wild-type cells is 1 kb, is reduced to 0.75 kb in mutant RC1707. Disruption of AGS1 rendered strains supersensitive to hygromycin B and increased their resistance to vanadate. In addition, ags1delta strains underglycosylated invertase but had normal carboxypeptidase Y glycosylation, suggesting that Ags1p is required for the elaboration of outer N-glycosyl chains. AGS3 was found to be identical to PHO80 (TUP7), which encodes a cyclin activating the Pho85p protein kinase. Deletion of either PHO80 or PHO85 led to aminoglycoside supersensitivity; pho80delta ags1delta strains showed an enhanced-sensitivity phenotype compared to single mutants. pho80 and pho85 mutants were rendered resistant by deletion of PHO4, indicating that activation of the Pho4p transcription factor is required for increased aminoglycoside sensitivity. Thus, both the Pho80p-Pho85p kinase complex (by Pho4p phosphorylation) and a novel component of the N glycosylation pathway contribute to basal levels of aminoglycoside resistance in Saccharomyces cerevisiae.

Amino Acid Sequence↗
PubMed1996

Defective threonine-linked glycosylation of human insulin-like growth factor in mutants of the yeast Saccharomyces cerevisiae.

Mutants of the yeast Saccharomyces cerevisiae were identified, in which O-glycosylation at threonine 29 of a heterologous protein, human insulin-like growth factor (hIGF-1), is defective. In mutant M195, O-glycosylation of hIGF-1, but not of yeast proteins chitinase and a-agglutinin, was reduced; in mutant M577 yeast proteins were affected besides hIGF-1. The mutations of M195 and M577 did not affect viability and could not be complemented by the PMT1 or PMT2 genes. The mutant phenotype of strain M195 was reconstituted in an in vitro system, in which a hIGF-1-derived peptide encompassing residues 24-34 was not used as acceptor for mannosylation, while unrelated peptides were glycosylated at wild-type levels. hIGF-1 glycosylation was drastically reduced in pmt1 disruptants and to a lesser extent in pmt2 disruptants, suggesting interaction between the PMT gene products and components mutated in M195 and M577 cells. The results suggest that mutations may only affect O-glycosylation of a specific subset of secreted proteins in yeast.

Amino Acid Sequence↗
PubMed1993

[High resolution autoradiographic detection of beta-gamma emitters in biological tissues: case of Indium 111].

The present paper proposes an efficient autoradiographic procedure for the microscopic localisation in biological tissues of both low energy electrons and electrons released at relatively high energy. These are emitted by radioactive tracers, decaying by electron capture and/or internal conversion, that are increasingly used in biology and medicine. A detailed inventory of the corpuscular and electromagnetic radiations has been established in the specific case of Indium-111, with emphasis placed on those presenting an autoradiographic interest. As far as the electromagnetic component is concerned, the probability for producing secondary electrons as a function of distance from the source has been calculated. The range of the electrons in the emulsion and in a tissue-like medium has also been taken into account. The comparison with experiments using isolated lymphocytes labelled with 111In-oxine confirms the feasibility to localize and quantify with a high resolution beta-gamma emitters within biological systems by autoradiographic imaging.

Autoradiography↗
PubMed1987

Human anti-endoplasmic reticulum autoantibodies appearing in a drug-induced hepatitis are directed against a human liver cytochrome P-450 that hydroxylates the drug.

"Anti-liver/kidney microsome" (anti-LKM) autoantibodies have been found in the serum of patients with cryptogenic chronic hepatitis and with immunoallergic drug-induced hepatitis, such as those induced by halothane or by tienilic acid (called anti-LKM2 in this case). So far the nature of the human microsomal macromolecules recognized by these antibodies has not been determined. Here we show, by using immunoblot techniques, that among the macromolecules present in human adult liver microsomes, one protein called cytochrome P-450-8 is specifically recognized by most sera of patients containing anti-LKM2 antibodies but not by control serum. Human fetal liver microsomes that do not contain cytochrome P-450-8 are not recognized by the anti-LKM2 antibodies. It is also shown that anti-cytochrome P-450-8 antibodies as well as human serum containing anti-LKM2 antibodies specifically inhibit the hydroxylation of tienilic acid by human liver microsomes. These results indicate that anti-LKM2 antibodies appearing in patients with hepatitis and concomitant administration of tienilic acid are directed against a cytochrome P-450 isoenzyme that catalyzes the metabolic oxidation of this drug. This suggests a possible mechanism for the appearance of anti-organelle antibodies in a drug-induced hepatitis.

Adult↗
PubMed1975

Experience with Dimer-X 1-ventriculography.

Positive contrast ventriculography was carried out in 72 cases, using the water-soluble contrast medium Dimer-X. The examinations were performed 1--3 days after ventricular drainage had been carried out to relieve raised intracranila pressure. After injection of 2--7.5 ml. of the medium into the non-anaesthetised patients -- including 37 children and juveniles -- the ventriculographs were taken under visual control using Mimer III. This method is simple and can be rapidly carried out. Radiographs taken in two planes, supplement by tomography if required, are sufficient for an accurate diagnosis. During the examination only two children suffered from vomiting, while another patient sustained a generalised convulsion because the contrast agent came into contact with the surface of the brain.

Adolescent↗