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Biomedical subjects

E Schmid

Publications and source records attributed to E Schmid.

At least 253 records · Page 14Linked to original sources

Intermediate-sized filaments present in Sertoli cells are of the vimentin type.

The cytoplasmic structure of Sertoli cells of rat testes has been studied by electron microscopy of ultrathin sections. Sertoli cells contain numerous intermediate-sized (7-11 nm) filaments which form a meshwork extending throughout the whole cytoplasm. Often the frequency of such filaments appears especially high in juxtanuclear and cortical regions, including the apical recesses containing the spermatids. Examination of frozen sections of testes by indirect immunofluorescence microscopy using guinea pig antibodies to prekeratin and vimentin has shown the absence of intermediate-sized filaments of the cytokeratin type in all cells of the testes but the presence of filaments of the vimentin type in Sertoli cells as well as in cells of the interstitial space. These results show that the intermediate-sized filaments, abundant in Sertoli cells, are of the vimentin type. In addition we conclude that the "germ epithelium" differs from others true epithelia by the absence of cytokeratin filaments and typical desmosomes and, in Sertoli cells, the presence of vimentin filaments, suggestive of a mesenchymal character or derivation.

Animals↗

[Indications and technic of subphrenic percutaneous drainage].

UNLABELLED: Introduction of percutaneous drainage (pcd) of subphrenic space in early subphrenic abscesses or fluid collections (e.g. bile) seems to be an alternative to common surgical treatment, if the indication is restricted to single contaminated abscesses. Septicemia, continued contamination, hematomas and multiple abscesses are contraindications. METHOD: A modified angiocatheter is placed directly or by a Seldinger technique. Adjunct antibiotic treatment is important. The advantages of subphrenic pcd are: simple low risk procedure in local anesthesia, rapid improvement of associated respiratory symptoms, no further contamination of the abdomen. 4 of 6 patients were treated successfully by this procedure.

Aged↗

Chromosome analyses in man in the course of chemoprophylaxis against tuberculosis and of antituberculosis chemotherapy with isoniazid.

Cytogenetic analyses were carried out in lymphocytes of 37 persons before and during a primary chemoprophylaxis or a preventive chemotherapy with isoniazid as well as of 30 patients suffering from active pulmonary tuberculosis before and during a chemotherapy with isoniazid in combination with two other antimycobacterial drugs. The results of the four participating research groups consistently reveal no indication for a chromosome damaging activity of isoniazid, of its metabolites in the human organism and of the administered drug regimens.

Adolescent↗

[Subanaesthetic doses of ketamine for obstetric delivery (author's transl)].

Twenty five parturients were anaesthetized by administration of 0.3 mg ketamine per kg body weight intravenously before emergence of the head of the newborn infant. 20 patients had complete amnesia for the time of delivery, but most of them remained cooperative, nevertheless. Of the other 5 patients, 3 recounted that they recalled the birth of their child like remembering a dream, but they did not remember pain. The method proved a failure in the case of two patients. The main advantage of this technique lies in keeping most of the parturients cooperative and able to help with pushing, while offering them amnesia and analgesia for this period. Comparison with thiopental and propanidide is discussed.

Adolescent↗

Haemodynamic effects of dopamine, epinephrine and orciprenaline (Alupent) in patients early after cardiac surgery.

The haemodynamic effects of Dopamine (100, 250 and 500 mcg/min), Epinephrine (4 and 8 mcg/min), Orciprenaline (4 and 8 mcg/min) and two combinations of Dopamine 250 mcg/min with Epinephrine and Orciprenaline 4 mcg/min respectively at constant infusion rates were studied in 21 patients after cardiac surgery. Special attention was payed to four types of catecholamine infusions during which the highest cardiac index (CI), 161-168% of control, was seen: Dopamine 500 mcg/min (D 500), Epinephrine 8 mcg/min (E 8), Dopamine 250 mcg/min combined with Epinephrine 4 mcg/min (D 250 + E4) and Dopamine 250 mcg/min combined with Orciprenaline 4 mcg/min (D 250 + Or 4). At the same time mean arterial pressure (MAP) was highest with D 500 (137%) and lowest during both combined infusions (120 and 125%). Total peripheral resistance (TPR) was lowest during the combined infusions (80 and 81% of control) and highest during D 500 (89%). The relative increase of stroke index (SVI) and heart rate (HR) in favor of SVI, given as a quotient SVI/HR, was highest with D 250 + E4(3.7), followed by E 8 (1.9), D 500 (1.6) and D 250 + Or 4 (1.3). It was concluded that a combined infusion of Dopamine and Epinephrine, both in low doses, is preferable to a high dose of Dopamine, or Epinephrine alone, producing the same increase of cardiac output with less afterload and less chronotropic effect than high doses of either drug alone.

Adult↗

Gangliosides of cultured cells of a rat mammary carcinoma cell line.

Ganglioside content of rat mammary carcinoma-derived cells grown in layers in vitro was nearly as high as that of apical membrane-derived milk fat globule membrane and nearly four time higher than the content of normal, lactating mammary tissue on a protein basis. The major ganglioside of these carcinoma-derived cells was identified as GDla (sialic acid-Gal-GalNAc-sialic acid)-Gal-Glc-Cer. Relative to carcinoma-derived cells, rat mammary tissue and milk fat globule membrane had more complex ganglioside patterns but appeared to lack substantial quantities of GDla.

Animals↗

The cytogenetic effect of bleomycin on human peripheral lymphocytes in vitro and in vivo.

The cytogenetic effect of bleomycin (BLM) in human lymphocytes was studied after exposure to different doses during the G0 and G2 phases. BLM produced a marked specific effect on the cell cycle. The main aberration types after exposure in tg0 were dicentrics and deletions; and after exposure in G2, open chromatid breaks. A linear dose--response was calculated for all these aberration types as well as for the number of aberrant cells. In the G2 experiments, partially and totally pulverized cells also increased linearly with dose. The intercellular distributions of the most frequent aberration types after exposure in G0 and G2--the dicentrics and chromatid breaks, respectively--showed over-dispersion. These results show that the cytogenetic effect of BLM may be compared with that of densely ionizing irradiation. Preliminary results of chromosome analysis of three cancer patients in the course of BLM therapy showed effects similar to those in the G0 experiments.

Bleomycin↗

Demonstration of the display of components of the endoplasmic reticulum system by indirect immunofluorescence microscopy using antibodies against cytochrome b(5) from rat liver microsomes.

Antibodies against the purified fragment of cytochrome b(5) released by trypsin treatment from rat liver microsomes were raised in rabbits and used for the demonstration of membranes rich in cytochrome b(5), in particular the endoplasmic reticulum (ER) system, by indirect immunofluorescence microscopy. The method allowed the demonstration of ER not only in frozen sections of various tissues, including liver and lactating mammary gland from different species, but also in cultured cells of a diversity of species and cell types. In the cultured cells the structures most prominently decorated with the antibodies against cytochrome b(5) were the nuclear envelope and the ER system which in many cells could be recognized as a system of smoothly bending, branching threads, extending from the perinuclear cytoplasm toward the cell periphery. Changes in the display of such elements during mitosis and cell plating and possible influences of the specific fixations used are discussed.

Animals↗

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↗

Paracrystalline arrays of membrane-to-membrane cross bridges associated with the inner surface of plasma membrane.

In cultured cells of the rat kangaroo PtK2 line, veils of the cell surface were observed which consisted of only plasma membrane and paracrystalline arrays of membrane-associated particles sandwiched in between. These membrane-to-membrane cross-bridging 9-to 11-nm wide particles were somewhat coumellar-shaped and were arranged on a hexagonal lattice with an interparticle distance of 16nm. At higher magnification, they revealed an unstained core, thus suggesting a ringlike substructure. Similar arrays of paracrystal-containing veils, which were rather variable in size and frequency, were also observed in other cultured cells. It is hypothesized that these paracrystals represent protein macromolecular complexes associated with the inner plasma membrane surface which crystallize when plasma membranes come into close intracellular contact and other components of the subsurface network are removed.

Animals↗