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Biomedical subjects

K Ziegler

Publications and source records attributed to K Ziegler.

At least 109 records · Page 6Linked to original sources
PubMed1986

[Intraoperative imaging of the small intestine for the endoscopic removal of small intestine polyps in Peutz-Jeghers syndrome].

The hamartomas in Peutz-Jeghers syndrome lead to various complications that are frequently followed by small-bowel resections and the development of a short-bowel syndrome. In order to prevent such complications an intraoperative endoscopic exploration of the entire small bowel with multiple polypectomies of hamartomas was carried out. Although a further growth of presently unrecognisable hamartomas is possible, such a procedure permits total polypectomy in Peutz-Jeghers syndrome, and complications are thus put off to a later time.

Adult↗
PubMed1985

Further characterization of 3'-isothiocyanatobenzamido[3H]cholate binding to hepatocytes. Correlation with bile acid transport inhibition and protection by substrates and inhibitors.

Binding of 3'-isothiocyanatobenzamido[3H]cholate ([3H]IBCA) to hepatocytes correlates to its efficacy in inhibiting cholate uptake in isolated hepatocytes. The correlation is linear up to 20 microM [3H]IBCA. Labeling of polypeptides is proportional to the degree of inhibition particularly for a protein of molecular weight 50 000. Transported substrates, competitive and non-competitive inhibitors of cholate transport protect against IBCA inhibition. Additionally binding of [3H]IBCA to isolated plasma membranes is prevented by the same substrates and inhibitors of the cholate transport system. The prevention is achieved by taurocholate, iopodate, iodipamide, furosemide, BSP, cyclosporin A, and somatostatin analogs. Protection is correlated to the degree of transport inhibition and depends on the hydrophobicity of the compounds. Other inhibitors known to destroy the driving forces such as valinomycin do not protect membrane proteins against coupling with IBCA. Silybin, which preferentially alters membrane fluidity, has little effect on the labeling. The above results give further evidence that IBCA, when applied in concentrations below 20 microM, is a suitable label for the hepatocellular bile salt transporter.

Affinity Labels↗
PubMed1985

[Leprosy--observations, experiences, problems].

From the field of view of own observative and experiences was tried to outline the present situation in leprosy. It is referred to the results of the modern epidemiological, bacteriological, immunological and medicamentous leprosy research which was particularly stimulated under the impression of the increasing DDS-resistance of the leprosy bacteria. At present ambulatory polychemotherapy, sometimes combined with a vaccination technique, is in the centre of the world-wide combat programme against leprosy. In no other infectious disease, however, social-economical points of view are so important as in leprosy and in the opinion of the author they are finally also decisive for an actually successful and permanent combat.

Diagnosis, Differential↗
PubMed1985

Modified somatostatins as inhibitors of a multispecific transport system for bile acids and phallotoxins in isolated hepatocytes.

Somatostatin inhibits the uptake of phallotoxins and of cholic acid in isolated liver cells in a concentration-dependent manner. The inhibition is independent on the preincubation period and fully reversed by switching to a somatostatin-free buffer. Concentrations needed for 50% inhibition decreased 30-80-fold when somatostatin was modified by variation of its amino acid sequence. Some cyclic hexa- or penta-peptides inhibited both kinds of transport more strongly as the original (14 amino acid) somatostatin did. Three of the analogs showed a 2-3-fold higher potency than the others. The most potent compound (cyclo (Phe-Thr-Lys-Trp-Phe-D-Pro) 1 was studied in detail. The IC50 for the initial uptake of phallotoxin (6 microM) or of cholate (6 microM) was 1.5 or 3 microM, respectively. 1 inhibited the uptake of cholate in a competitive manner. The inhibition was independent on the preincubation time, but in contrast to somatostatin not fully reversible after a preincubation of 35 min. Somatostatin as well as its analogs prevented binding of isothiocyanatobenzamido [3H]cholate (an affinity label of the cholate transporter) to isolated plasma membranes from rat liver. The transport inhibition of cholate uptake is unlikely to be a hormonal effect of somatostatin, because the concentrations needed are approx. 1000-fold higher than circulating levels; however, it is apparently possible to increase the inhibitory potency on the tested transport system by modification of the sequence without increase of the well-known hormonal effects (Designing Activity and Receptor-Selectivity in Cyclic Peptide Hormone Analogs, Kessler, H., 18th Ervag Conference, Brussels, 1983).

Amanitins↗
PubMed1985

Use of immunoblot technique for detection of human IgE and IgG antibodies to individual silk proteins.

Allergenic proteins were extracted from one silk batch that was imported to be used as filling material for bed mattresses and rugs. IgE and IgG antibodies to the extracted silk proteins were measured by RAST in sera of nine silk-sensitive persons as well as in sera of healthy control donors. Silk proteins were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis into 12 polypeptides of molecular weights between 14 and 70 kilodaltons. By means of the immunoblot technique, IgE and IgG antibodies to the individual silk polypeptides could be detected. Sera of silk-sensitive persons contained high titers of IgE and low titers of IgG antibodies to the separated silk polypeptides. Sera of control donors contained low IgG antibody titers to a limited number of these polypeptides.

Adult↗
PubMed1984

Cyclosporin A protects liver cells against phalloidin. Potent inhibition of the inward transport of cholate and phallotoxins.

Cyclosporin A at concentrations of more than 10 nM protects isolated hepatocytes against the action of phalloidin. Cyclosporin A at 100 nM inhibits the uptake of demethyl[3H]phalloin by 50%, and at 5 microM also that of [14C]cholate. This inhibition is independent of the preincubation period and is not reversed by washing the cells. With a 30-60-fold excess of cyclosporin A, affinity labeling of plasma membrane proteins using 12 microM [3H]isothiocyanatobenzamido cholate was reduced to 40-60% of the control. These findings indicate that transport inhibition by cyclosporin A in liver cells cannot be explained by simple competition on the level of the membrane protein(s) involved.

Affinity Labels↗
PubMed1984

3'-Isothiocyanatobenzamido[3H]cholate, a new affinity label for hepatocellular membrane proteins responsible for the uptake of both bile acids and phalloidin.

Substitution of the hydroxyl group on C7 of cholic acid by a benzamido group leads to a derivative with inhibiting quality for the inward transport of both bile acids and phallotoxins by isolated liver cells. The tritiated isothiocyanate derivative was prepared (3'- isothiocyanatobenzamido [3H]cholate, [3H] IBCA ) with a specific activity of 70-80 mCi/mmol. The latter compound was used for affinity labeling of liver plasma membranes in order to detect chemically modified proteins involved in the transport of bile acids. [3H] IBCA and the noncovalently binding analogs were recognized by the transport system; they inhibited the uptake of both [14C]cholate and of demethyl[3H] phalloin in vitro. Isothiocyanatobenzamidocholate ( IBCA ) was able to protect isolated hepatocytes against phalloidin. In isolated and purified plasma membranes prepared from liver cells [3H] IBCA binds to saturable sites in an irreversible manner. Micromolar concentrations of unlabeled IBCA or millimolar concentrations of natural substrates prevented [3H] IBCA binding in a concentration dependent manner; some other substrates of the transport system also protected liver membranes against chemical modification. Membranes from AS- 3OD hepatoma cells, well known to transport neither bile acids nor phallotoxins, could not be labeled by [3H] IBCA . The major targets of labeling in hepatocellular plasma membranes were polypeptides with molecular mass of 67, 60, 54, 50, and 37 kDa as shown by SDS-polyacrylamide gel electrophoresis (10% acrylamide). The 67 kDa protein could be found in the aqueous phase after phase separation in Triton X-114. The 54 kDa and 50 kDa proteins remained in the detergent phase and can therefore be regarded as integral membrane proteins.

Affinity Labels↗
PubMed1984

Further characterization of membrane proteins involved in the transport of organic anions in hepatocytes. Comparison of two different affinity labels: 4,4'-diisothiocyano-1,2-diphenylethane-2,2'-disulfonic acid and brominated taurodehydrocholic acid.

4,4'-Diisothiocyano-1,2-diphenylethane-2,2'-disulfonic acid (H2DIDS) known as an irreversible inhibitor of the anion transport in red blood cells (Cabantchik, Z.I. and Rothstein, A. (1972) J. Membrane Biol. 10, 311-330) blocks also the uptake of bile acids and of some foreign substrates in isolated hepatocytes (Petzinger, E. and Frimmer, M. (1980) Arch. Toxicol. 44, 127-135). [3H]H2DIDS was used for labeling of membrane proteins probably involved in anion transport of rat liver cells. The membrane proteins modified in vitro by [3H]H2DIDS were compared with those labeled by brominated taurodehydrocholic acid. The latter is one of a series of suitable taurocholate derivatives, all able to bind to defined membrane proteins of hepatocytes and also known to block the uptake of bile acids as well as of phallotoxins and of cholecystographic agents (Ziegler, K., Frimmer, M., Möller, W. and Fasold, H. (1982) Naunyn-Schmiedeberg's Arch. Pharmacol. 319, 254-261). The radiolabeled proteins were compared after SDS-electrophoresis with and without reducing agent present, solubilization by detergents, two-dimensional electrophoresis and after separation of integral and peripheral proteins. Our results suggest that the anion transport system of liver cells cannot distinguish between bile acids and the anionic stilbene derivative (DIDS). The labeling pattern for both kinds of affinity labels was very similar. Various combinations of separation techniques gave evidence that the radiolabeled membrane proteins are not subunits of a single native channel protein.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1984

Gluten intolerance (coeliac disease).

Coeliac disease is a permanent condition of gluten intolerance associated with characteristic gluten-sensitive changes in the jejunal mucosa. In Edinburgh and the Lothians Region of Scotland, the prevalence of the disease is one in 1637 (61/100,000) with considerable variation in age, and sex-specific prevalence and incidence. Several lines of evidence indicate an immunologic basis for the gluten-sensitive enteropathy in coeliac disease. Animal models of intestinal T cell-mediated reactions in the gut have shown pathologic features similar to those of coeliac disease. These include changes in villus and crypt architecture with crypt hyperplasia, and increased numbers of intraepithelial lymphocytes and of intraepithelial lymphocyte mitosis. Experimental CMI reactions also influence differentiation of goblet cells and expression of Ia antigen on epithelial cells, but these factors have not yet been reported for the coeliac mucosa. In addition to this circumstantial evidence, based on animal work, other factors which suggest that CMI reactions rather than antibodies are relevant to coeliac disease include the findings of antigliadin antibodies in a proportion of normal individuals, patients without gastrointestinal disease (seen in hospital), and patients with jejunal Crohn's disease. In addition, there is a well documented patient with adult onset primary hypogammaglobulinaemia and coeliac disease. The underlying pathogenesis in coeliac disease can be envisaged as failure of the normal inhibition of immune responses to this particular food antigen in the gut. Manipulation of immunoregulatory mechanisms would provide a new approach to treatment or cure of this disease and of other food protein-sensitive enteropathies.

Adult↗
PubMed1984

[Simultaneous combined radio-/chemotherapy of locally recurring breast cancer].

Combined simultaneous radiochemotherapy is our treatment conception for the locoregionally recurrent mammary carcinoma. With this therapy, complete or partial remissions are achieved in 92%. In only 25%, another recurrence appears within the irradiated region. The median survival time is 23 months. The results of the chemotherapy combination CMFV are better than the results of other combinations. Due to the good local effect, the quality of life without tumor of the thoracic wall is improved.

Adult↗
PubMed1983

[Clinical aspects and therapy of schistosomiasis].

Among 810 parasitologically examined persons (1981) 277 (34%) showed positive findings. The high percentage of parasitisation in foreigners (86%) is to be explained by the in most cases aimed transfer of these patients (215 of the 810 persons). Affection with Schistosoma was recognized in 51 patients at the age of 17-47 years (means = 21.86), without Africans, and stood in the 3rd place of the distribution of frequency of the heterogeneous parasitoses. 49 of these patients came from Mozambique, 1 from Namibia and 1 from Zambia. In 51% S. haematobium was diagnosed, in 22% S. mansoni and in 27% a double infestation with the two forms of parasites. While 80% of the patients with affection of S. haematobium showed clinical symptoms (macrohaematuria, cystitis complaints), there were only 44% among the S. mansoni group. 47 patients were treated with Niridazole (Ambilhar, 25 mg/kg, 5-7 days), 2 patients with Praziquantel (Biltricide, 40 mg/kg, 1 day) and 2 other patients with Praziquantel after unsuccessful Niridazole therapy. Follow-up examinations were performed after 1, 3, 6 and 12 months. In 17% of the patients treated with Niridazole the primary treatment did not lead to cure; side effects (abdominal pain, nausea, vertigo) were observed in 55%. Praziquantel was tolerated very well. During a control period of 1 year living eggs of Schistosoma were no more proved.

Adolescent↗
PubMed1982

Affinity labels for membrane components involved in the uptake of bile acids and of phallotoxins by hepatocytes. Development of covalently binding derivatives of bile acids and of compounds related to cholecystographic agents.

A series of covalently binding derivatives of bile acids, fusidic acid and of compounds similar to cholecystographic agents were synthesized. Nearly all of them inhibited the development of protrusions on the surface of isolated hepatocytes regularly seen after treatment with phalloidin. The same compounds inhibited the uptake of demethylphalloin and of cholate in a concentration dependent manner. Two kinds of effects could be distinguished: The irreversible part of the inhibition depended on the incubation period and could not be removed by washing procedures. The reversible one was independent on the duration of the preincubation. Final results indicated that the tested derivatives inhibited either both transports, and the phalloidin response of liver cells to the same degree and in the same manner, or were found to be ineffective in all tests. The above parallelism supports the hypothesis that phallotoxins may be translocated by a carrier system normally responsible for the uptake of bile acids from the portal blood.

Affinity Labels↗
PubMed1982

Chemical modification of membrane proteins by brominated taurodehydrocholate in isolated hepatocytes; relationship to the uptake of cholate and of phalloidin and to the sensitivity of hepatocytes to phalloidin.

In vitro treatment of isolated rat hepatocytes with brominated taurodehydrocholic acid (BTC) reduced their sensitivity against phalloidin and inhibited the uptake of phalloidin as well as of cholate in an irreversible and concentration dependent manner. BTC was taken up itself by liver cells; this process was inhibited by 4,4'-diisothiocyano 2,2'-stilbene disulfonate (DIDS). When hepatocytes were incubated with 35S-BTC their plasma membranes contained five labeled protein species with molecular weights of 67,000, 49,000, 38,000, 32,000 and 24,000 as shown by SDS-electrophoresis. No marked difference was observed when isolated plasma membranes from livers were directly treated with the affinity label. DIDS suppressed covalent binding of 35S-BTC to membrane components drastically. Incubation of phalloidin insensitive AS-30D ascites hepatoma cells with 35S-BTC did not result in a chemical modification of the above five proteins. This agrees with an earlier observation that hepatoma cells are unable to take up phalloidin and bile acids (Petzinger et al. 1979; Rufeger and Grundmann 1977; Kroker et al. 1978).

Affinity Labels↗