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Biomedical subjects

F Meyer

Publications and source records attributed to F Meyer.

At least 253 records · Page 14Linked to original sources
PubMed1979

[Corticosteroid-sensitive chemical diabetes in Horton's disease].

We report 5 cases of temporal arteritis associated with a diabetes whose good evolution under corticotherapy suggests a common pathogenesis. Several hypotheses can be formulated to explain the origin of the glycemic abnormality and to understand the way corticotherapy is effective. A moderate posology could at first have a hyperplasic effect on the insulin-secreting cells, and later on a favorable action on the vascular lesion and on an immunological disorder. Any definitive conclusion cannot be evolved yet. Only a more systematical study of the glycoregulation's abnormalities in the temporal arteritis will enable to answer the many remaining questions.

Adrenal Cortex Hormones↗
PubMed1979

Lipid biosynthesis in the marine flatworm Convoluta roscoffensis and its algal symbiont Platymonas convoluta.

As a part of an investigations on the lipid metabolism in Platyhelminthes, the acoel Convoluta roscoffensis, which harbors the green alga Platymonas convoluta as a symbiont, was studied. Isotopic tracer experiments established that the acoel lacks the ability to synthesize de novo long-chain saturated and unsaturated fatty acids and depends on its algal symbiont for these compounds. The acoel's fatty acid composition closely resembles that of the alga but differs from those of other animals; the acoel's polyunsaturated fatty acids are of the plant type (omega 3 family) rather than of the animal type (omega 6 family). The acoel also lacks the ability to synthesize sterols de novo. It contains 24-methylenecholesterol synthesized by the algae and, in addition, significant amounts of cholesterol, which is probably a host modification product of the algal sterol. With fatty acids provided by the symbiont, the acoel has the ability to synthesize its own complex lipids. The acoel contains relatively large amounts of triglyceride, phosphatidylcholine, and ethanolamine plasmalogen. These compounds are either not present at all or present only in minute amounts in the symbiotic alga. Since acoels belong to the most primitive forms of the present-day flatworms, the observed metabolic defects in this organism suggest that mechanisms for the biosynthesis of fatty acids and sterols were lost early during the evolution of the Platyhelminthes, and that this phenomenon is widespread within the phylum.

Aging↗
PubMed1979

[Malabsorption syndrome during the initial phase of a case of severe rheumatoid purpura].

We report a case of severe Henoch syndrome in which the first manifestation was digestive with a prolonged and important intestinal malabsorption syndrome. The clinical, radiological and histological data allow to consider a malabsorption due to lesions of the chorion and submucosa probably secondary to the allergic vasculitis. The malabsorption syndrome, confirmed by the intestinal absorption tests, the study of which must be more systematic, seems to belong to the severe and polyvisceral forms of the Schönlein-Henoch syndrome.

Abdomen, Acute↗
PubMed1979

Writing apparatus controlled by head movements for motor handicapped people.

For a motor disabled person who cannot use his arms and hands we have constructed a device that enables him to operate a typewriter by means of head movements, via a forehead lamp. The text is first displayed on a picture screen and, after introducing any corrections, typed on a printer. This writing apparatus has been used very intensively for one year now, and evaluation laid down by the user himself has been included in the present paper. Several factors relevant to a large-scale application of this apparatus are discussed.

Journal Article↗
PubMed1979

Iterative image transformations for an automatic screening of cervical smears.

The new generation of image analysis systems permits the use of iterative image transformations. It is now possible to construct algorithms where the elementary steps are not arithmetic operations but image transformations. This will be illustrated by two examples. In the first, the absorption image of Feulgen Stained nuclei is processed by contrast algorithms in order to detect suspect cells. In the second, free lying cells are separated from overlapping cells and other artefacts by the use of skeletonization procedures.

Carcinoma↗
PubMed1978

Acyl-coenzyme A carboxylase of the free-living nematode Turbatrix aceti. 1. Its isolation and molecular characteristics.

A biotin containing enzyme which carboxylates acetyl-CoA has been isolated from the nematode Turbatrix aceti and purified to homogeneity as judged by the criteria of polyacrylamide gel electrophoresis and ultracentrifugation. The enzyme has a sedimentation coefficient of 18.0 S and a molecular weight of 667 000. It is composed of four protomers having a molecular weight of 140 000 each. Each protomer, in turn, consists of two distinct polypeptide chains (molecular weights 82 000 and 58 000) and one biotinyl prosthetic group which is linked to the 82 000 peptide. The amino acid composition of the nematode carboxylase has also been determined.

Acetyl Coenzyme A↗
PubMed1978

Acyl-coenzyme A carboxylase of the free-living nematode Turbatrix aceti. 2. Its catalytic properties and activation by monovalent cations.

A highly purified acyl-CoA carboxylase from the nametode Turbatrix aceti catalyzes the ATP, Mg2+, and HCO3- dependent alpha-carboxylation of acetyl-CoA, propionyl-CoA, and butyryl-CoA at the respective rates of 6.8, 39.7, and 9.1 mumol per min per mg. The enzyme is inhibited by avidin and sulfhydryl reagents. It is activated up to 30-fold by the monovalent cations K+, Rb+, Cs+, or NH4+, with the apparent activation constants of 11.0, 4.1, 10.0, and 6.7 mM, respectively. In the presence of K+, the apparent Km for ATP increases 5-fold, and the Km for HCO3- decreases 4-fold, whereas the Km for propionyl-CoA remains constant. Of the partial reactions, the ATP-32P exchange reaction and the carboxylation of free biotin have a nearly absolute requirement for K+. By contrast, the [14C]acetyl-CoA-malonyl-CoA exchange reaction proceeds without K+ at 80% of its maximum rate. The data indicate that K+ primarily stimulates the first half of the carboxylation reaction, i.e., the ATP-dependent carboxylation of the biotinyl residue.

Animals↗