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Biomedical subjects

K Weber

Publications and source records attributed to K Weber.

At least 667 records · Page 37Linked to original sources
PubMed1978

Actins from mammals, bird, fish and slime mold characterized by isoelectric focusing in polyacrylamide gels.

Actins isolated from a variety of tissues and cultured cells were compared by isoelectric focusing in polyacrylamide gels in the presence of 9 M urea and 2% Nonidet P40. Actins isolated from muscle tissue with a sarcomeric structure like skeletal muscle and heart muscle invariably display, as previously shown, one single band with a pI of approximately 5.4 (alpha-actin) in isoelectric focusing gels. Actins isolated from mammalian or avian non-muscle tissue and cultured mammalian cells display two polypeptide bands (beta and gamma-actins) focusing at a slightly higher pH than alpha-actin as a closely spaced doublet. A gamma-like actin is the predominant species in chicken gizzard actin. However, this gamma-like form is not isoelectrically identical with gamma-actin from brain. These results are discussed in relation with the currently available amino acid sequence data known for different actins. Actin isolated from the liver of the electric fish Torpedo marmorata appears to consist of a single isoelectric species with an apparent isoelectric point similar to the beta-actin component of mammalian brain. The actin from the slime mold Physarum polycephalum shows only one single major band in isofocusing gels with an isoelectric point lower than that of alpha-actin.

Actins↗
PubMed1978

[Cimetidine in the treatment of duodenal ulcer (author's transl)].

In a double-blind trial of patients with duodenal ulcer at three centres the healing rate after a four-week course of treatment (1 g cimetidine daily) was 79% (30 out of 38 patients), compared with 58% (23 out of 40 patients) on placebos. Cimetidine did not effect subjective symptoms or the need for antacids to relieve pain, except for a minor beneficial effect on diurnal ulcer symptoms during the second week of treatment. Results of long-term administration suggest that cimetidine at 400 mg daily prevent s relapses, but the possibility of an increased relapse rate after cimetidine withdrawal can not as yet be excluded.

Adult↗
PubMed1978

Indirect immunofluorescence microscopy of microtubular structures in male germ cells of wildtype and l(3)pl (lethal-polyploid) Drosophila hydei.

Tubulin-containing structures of the male germ cells of Drosophila hydei crossreact in indirect immunofluorescence microscopy with antibody directed against homogeneous porcine brain tubulin. There is no detectable difference in reactivity between germ cells of wildtype flies and the mutant l(3)pl (lethal-polyploid) which is characterized by microtubular abnormalities. However, the technique of indirect immunofluorescence microscopy allows the direct visualization of several abnormalities in the arrangement of the microtubular system of the mutant, particularly in the axonemal complex.

Animals↗
PubMed1978

The intracellular organization of actin and tubulin in cultured C-1300 mouse neuroblastoma cells (clone NB41A3).

Cells of clone NB41A3 of the C-1300 mouse neuroblastoma were grown to a critical density at which many of the cells flatten, assume a variety of shapes and sizes and some sprout processes resembling neurites. We have studied the distribution of actin and tubulin in these cells using fluorescence microscopy and antibodies against actin or tubulin under these conditions. Actin-containing structures are variably arranged and predominantly associated with motile areas of the cell periphery including the growth cone. Microtubules appear to run radially from the perinuclear area towards the cell periphery. When neurites are present, microtubules converge into them and run to the growth cone but rarely contact its edge.

Actins↗
PubMed1978

Stereo immunofluorescence microscopy: I. Three-dimensional arrangement of microfilaments, microtubules and tonofilaments.

An easy manipulation of the commercial fluorescence microscope allows stereo pairs of pictures to be taken, which when examined with a stereo viewer, give a strong three-dimensional impression. The procedure is described in detail. Its use allows the documentation by immunofluorescence microscopy of the three-dimensional display and organization of microfilament bundles, microtubules and tonofilaments in some well characterized tissue culture cell lines.

Actins↗
PubMed1978

Radioimmunoassay for tubulin: a quantitative comparison of the tubulin content of different established tissue culture cells and tissues.

A quantitative estimate of the cellular tubulin concentration can be obtained by the use of a radioimmunoassay based upon the competition between tubulin in cell extracts and a known amount of radioactively labeled homogeneous tubulin during binding to a limited amount of anti-tubulin antibodies. This assay shows that a variety of widely used tissue culture cells (mouse L cells, mouse 3T3 cells, chick embryo fibroblasts) have a tubulin content which corresponds to approximately 2.5--3.3% of their total protein. Transformation of mouse 3T3 cells by the DNA virus SV40, and of chick embryo cells by the RNA Rous sarcoma virus, does not change the intracellular tubulin concentration. Transformed cells of brain origin, such as some glia tumor cell lines and some neuroblastoma cell lines, have a much lower tubulin content than does normal brain tissue. The intracellular concentration of tubulin in mouse 3T3 cells is discussed in relation to the number of microtubules detected during interphase by immunofluorescence microscopy. These results are also discussed in view of a mechanism of microtubule elongation in vivo driven by self-assembly.

Brain Chemistry↗
PubMed1978

Reaction of tonofilament-like intermediate-sized filaments with antibodies raised against isolated defined polypeptides of bovine hoof prekeratin.

Total purified and reconstituted bovine hoof prekeratin, containing several polypeptides, as well as individual polypeptide size classes isolated therefrom were used as antigens in guinea pigs. The antibodies raised against these protein preparations were found to decorate the system of wavy arrays of tonofilament-like, intermediate-sized filaments present in various epithelial and epithelia-derived cells. Strong cross-reaction between different vertebrate species was noted, including amphibia. Positive results were obtained with original sera as well as with IgG fractions and antibodies made monospecific by chromatography on total bovine prekeratin covalently bound to Sepharose. Among the antisera raised against the different polypeptide size classes the most intense decoration of fibrillar arrays was obtained with antibodies against fraction 4 which contained polypeptides VI and VII.

Animals↗
PubMed1978

[Venous angiomas of the brain (author's transl)].

In three patients with cerebral ictal attacks, a diagnosis of a cerebral venous angioma was made, based on angiography, the symptoms and the clinical findings. All vascular malformations lay in the rostral cerebrum. In two patients, dilated medullary veins converge towards the origin of a dysplastic draining vein (type I), in the third case the medullary veins terminated in two veins of medium calibre which lead into a large venous drainage system (type II). In two of the three cases, there was calcification, one of these in a subeppendymal mass (? old haematoma). There was scintigraphic evidence of local disturbance of the bloodbrain barrier of Venous angiomas. The brain must be differentiated from other lesions, such as vascular gliomas and metastases.

Adult↗
PubMed1978

Different intermediate-sized filaments distinguished by immunofluorescence microscopy.

The major protein of intermediate-sized filaments in mouse 3T3 cells, for which the name vimentin is proposed, has a molecular weight of 57,000. Antibodies against vimentin and antibodies against prekeratin have been used in parallel in immunofluorescence microscopy on a variety of cultured cells as well as on frozen tissue sections. Both antibodies decorate extended wavy arrays of filaments that are different from microfilaments and microtubules. Intermediate filament bundles decorated by antibodies against prekeratin are predominant in many epithelial cells, including epithelia-derived tumor cells, and are not decorated by antibodies to vimentin. In contrast, intermediate filaments decorated by antibodies against vimentin are widespread among nonmuscle cells of mesenchymal origin, including transformed cells, and also occur in other cells. Perinuclear whorls of aggregates of intermediate filaments induced by prolonged treatment with Colcemid generally show strong decoration with antibodies against vimentin. No significant reaction with either antiserum has been observed in muscle structures or in brain nerve tissue. These observations show that intermediate filaments with similar ultrastructure and solubility characteristics can be distinguished immunologically.

Cells, Cultured↗