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Biomedical subjects

G Wick

Publications and source records attributed to G Wick.

At least 343 records · Page 19Linked to original sources
PubMed1978

The diagnostic application of specific antiprocollagen sera. II. Analysis of liver biopsies.

Frozen, unfixed sections of human liver biopsies from patients with acute, subchronic, and chronic hepatitis or fibrotic liver disease were studied in indirect immunofluorescence with specific antisera to type I and type III procollagen. In early stages of both hepatitis and fibrotic liver disease, intralobular type III collagen synthesis is increased. Maximum values are reached years after the onset of disease. Intralobular procollagen I content is not increased in the acute stage, but rises only later. An increase of procollagen I seems to herald irreversible liver changes. This approach allows for exact localization and semiquantitative analysis of the synthesis of type I and type III collagen, and adds a new parameter to the diagnostic approaches in liver diseases.

Adolescent↗
PubMed1978

Fluorescence properties of free and protein bound fluorescein dyes. I. Macrospectrofluorometric measurements.

Excitation and emission properties of fluorescein derivatives were studied macrofluorometrically. Measurements were performed with solutions of various concentrations (0.07-100 microgram/ml) of free sodium fluorescein prepared from fluorescein diacetate (FDA), fluorescein isothiocyanate (FITC) and FITC bound to rabbit gamma-globulin. Both excitation and emission spectra as well as fluorescence intensities at constant excitation/emission wavelengths (496/515 nm) were recorded. The findings indicate that (1) FDA gives about twice the fluorescence intensity compared to equal concentrations of FITC. (2) The fluorescence properties of FITC upon excitation with blue light (lambda = 496 nm) are only slightly altered by the conjugation to rabbit gamma-globulin. (3) Considerable quenching due to conjugation could, however, be shown to occur upon UV excitation (lambda = 340 nm). (4) Fluorescence emission excited by visible blue light (496 nm) increases linearly to dye concentration in a range of 0.07-2.5 microgram/ml. Beginning at 5 microgram/ml (10-(5) M/1) all three compounds show a sharp decrease of fluorescence intensity with further increasing concentration. Practical aspects of these data for the immunofluorescence method are discussed.

Animals↗
PubMed1978

No development of experimental autoimmune thyroiditis in nude mice.

Homozygeous nu/nu mice do not develop experimental autoimmune thyroiditis and circulating thyroglobulin autoantibodies after two immunizations with murine thyroid extract and fortified complete Freund's adjuvant. However, heterozygeous nu/+ mice are perfectly apt for the induction of both thyroiditis and thyroglobulin autoantibodies. These results provide further evidence for the assumption that the development of experimentally induced autoimmune thyroiditis depends on the presence of T-cells as opposed to the spontaneously occurring autoimmune thyroiditis in Obese strain (OS) chickens which is mediated by B-effector cells. The present data further show that thyroglobulin is a T-dependent antigen in the mouse.

Animals↗
PubMed1978

Immunofluorescent localization of thyroglobulin--autoantibody producing cells in various organs of obese strain (OS) chickens.

The Obese strain (OS) of White Leghorn chickens develops a spontaneous autoimmune thyroiditis with circulating thyroglobulin-autoantibodies (Tg-AAb) similar to human Hashimoto thyroiditis. The paper describes attempts to localize the site of Tg-AAb production in various organs of these animals using the immunofluorescence method. Tg-AAb producing plasma cells and germinal centers could be detected in the infiltrated thyroid glands but not in spleen, bone marrow, coecal tonsils, thymus, bursa of Fabricius and Harderian glands.

Animals↗
PubMed1978

[Identification of thyroglobulin-binding cells in the blood of Hashimoto patients (author's transl)].

We developed a new method for demonstration and enumeration of antigen-binding cells, the principle and application of this method is demonstrated using peripheral blood lymphoid cells from Hashimoto patients, non-Hashimoto, non Graves' disease goiter patients and in patients without thyroid disease. A significantly higher number of thyroglobulin-binding cells was observed in the peripheral blood of Hashimoto patients as compared to members of the two other groups. The results of the FICA-tests were compared to conventional serological data of the individual patients.

Aged↗
PubMed1978

Immunohistologic analysis of fetal and dermatosparactic calf and sheep skin with antisera to procollagen and collagen type I.

Immunofluorescent analysis of bovine and sheep skin using antibodies to the biosynthetic precursor pn-collagen type I, demonstrated that the localization of pn-collagen is restricted to the stratum papillare in adult skin. In contrast, antibodies against pn-collagen type I stained the whole dermis in skin obtained from dermatosparactic cattle and sheep. Electron microscopy of dermatosparactic sheep skin stained with ferritin-labeled anti-pn-collagen type I antibodies further demonstrated that pn-collagen molecules are the structural components of the unusual, twisted collagen fïbers observed in dermatosparactic skin.

Animals↗
PubMed1977

[Preparation of antilymphocytic globulin by means of repeatedly-used immunoadsorbents (author's tranl)].

A method is described for the purification of horse anti-human lymphocyte serum, whereby absorption of haemagglutinating antibodies was performed with human RBC ghosts. These ghosts were repeatedly used after desorption. Desorption was carried out in glycine-HCl buffer solution pH = 3,0. The advantages of this method consist of a reduction in the amount of RBC needed for absorption and the relatively low loss of lymphocytotoxic antibodies. The final product is effective in an in vitro test system and complies with the requirements for human use.

Animals↗
PubMed1977

Some methodologic aspects of the chromium chloride method for coupling antigen to erythrocytes.

The influence of various methodological variables on the CrCl3 technique for coupling antigen to the surface of erythrocytes has been investigated. Tests should be performed in protein- and phosphate-free medium. The CrCl3 stock solution should be stored at a pH of 5.0 and working dilultions prepared in acetate buffer (pH 5.5). The coupling procedure itself was performed as described by Goding (1976) with slight modifications. The relation between antigen and CrCl3 concentrations was found to be of crucial importance as excess of antigen inactivates CrCl3 whereas lack of antigen or excess of CrCl3, leads to spontaneous agglutination. A preliminary test based on determination of the minimum concentration of CrCl3 which produces spontaneous agglutination in the absence of antigen, and coupling if antigen is available, can be employed to predict the optimal concentration with sheep, human or chicken red blood cells. The pH-dependency of the coupling process is emphasized.

Animals↗
PubMed1977

Fluoro-immuno-cytoadherence (FICA): A new method for the identification and enumeration of antigen-binding cells.

Antigen-coated particles of cross-linked dextran may be used for affinity chromatography of antibodies and for the fractionation of lymphoid cells with appropriate surface receptors. Furthermore, such particles serve as convenient substrates for quantitative immunofluorescence tests. The fluoro-immuno-cyto-adherence (FICA) is a simple technique which combines affinity chromatography and immunofluorescence, provides durable antigen-coated substrates and allows the identification, enumeration and characterization of lymphoid cells capable of binding an antigen, covalently linked via a spacer onto the surface of dextran beads. In the present study chicken thyroglobulin (TG) or bovine serum albumin (BSA) were coupled onto fluorescein and rhodamin-labelled or unlabelled Sephadex G-25 beads by means of spacer molecules. The specificity and degree of antigen-coating were controlled by indirect immunoflourescence. For the study of antigen-binding cells the different antigen-coated beads were mixed with suspensions of peripheral blood lymphoid cells from Obese strain (OS) chickens with spontaneous hereditary autoimmune thyroiditis, or with cells from BSA-immunized or unimmunized normal White Leghron chickens. Specific adherence of OS lymphocytes to TG-coated beads and of lymphocytes from BSA-immunized chickens to BSA-beads was found. The test and control preparations are observed simultaneously under the fluorescence microscope where the distinction of beads coated with different antigens can be made on the basis of the color of their fluorescence. Results obtained with the FICA technique are in good agreement with those of conventional rosette tests.

Animals↗
PubMed1977

Immunological dissection of rat pregnancy: study of the mode of action of antisera to luteinizing hormone.

The sensitivity of rat pregnancy to luteinizing hormone (LH) depletion on days 7--12 (day 1 = day of insemination) was investigated by intraperitoneal administration of a single injection of various doses of an anti-bovine LH rabbit serum on the day in question. Day 11 was found to be the most susceptible time for this kind of intervention. The fate of the anti-LH antibodies in the recipients was followed in the serum and in various organs of the treated animals. Serological analysis revealed persistence of free antibodies to LH in the serum as late as 48 hr after injection. Immunofluorescence studies showed immune complex deposition in the kidney glomerula.

Animals↗
PubMed1977

Immunofluorescence localization of thyroglobulin autoantibody producing cells in various organs of obese strain (OS) chickens.

All major lymphoid organs from animals of the Obese strain (OS) of chickens which develop a spontaneous autoimmune thyroiditis with circulating thyroglobulin autoantibodies (Tg-AAb) were investigated for Tg-AAb producing cells using the immunofluorescence method (IF). No Tg-binding cells could be detected in spleen, bursa. Harderian glands, thymus, coecal tonsils or bone marrow. The infiltrated thyroid gland was shown to be the only site of Tg-AAb production detectable by IF.

Animals↗