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Biomedical subjects

G Wick

Publications and source records attributed to G Wick.

At least 361 records · Page 20Linked to original sources
PubMed1977

Relationship between E receptors and a T-specific surface antigen on human T cells.

The aim of this study was the delineation of different antigenic surface determinants on the surface of adult peripheral T cells by means of a specific horse anti-human T-cell serum (ATS). It was shown that this serum reacts both with E receptors and (an) additional T antigen(s). While E receptors showed the already known susceptibility to trypsin, T antigens (as demonstrated in cytotoxicity tests) were resistant to trypsinization even at high concentration. Incubation of the trypsinized peripheral blood lymphocytes (PBL) in 5 per cent CO2 allowed the resynthesis of E-receptors. High concentrations of ATS (without complement) significantly inhibited rosette-formation. This suggests a close steric relationship between E receptors and T antigen(s). However, absorptions of ATS with trypsinized PBL left the E-rosette inhibitory capacity unaltered. Treatment of PBL with ATS in appropriate dilutions and indirect immunofluorescence tests under capping conditions followed by conventional rosette procedures showed that the E receptor and T antigens are separately mobile within the T-cell membrane.

Antigens↗
PubMed1976

Preparation and use in immunohistology of antibodies specific for type I and type III collagen and procollagen.

Antibodies to bovine type I and type III collagen and their precursor form procollagen were produced in rabbits and rendered specific for the immunizing antigen by immunoadsorption. These purified antibodies showed distinct immunofluorescence staining on frozen sections of both bovine and human connective tissue at concentrations as low as 1-10 mug/ml. Antibodies to type III collagen and procollagen reacted with reticulin in liver and spleen, with fascicles around tendons and with the upper portion of the dermis. Antibodies to type I collagen and procollagen reacted with skin and fiber bundles in tendon but did not stain reticulin. No reaction was observed with cartilage collagen or with kidney glomerular basement membrane.

Animals↗
PubMed1976

The micro-membrane-fluorescence test: a new semiautomated technique based on the microtiter system.

A semiautomated modification of the membrane immunofluorescence (MF) technique was developed employing units of the Microtiter system. This new rapid technique, which allows the performance of several hundred samples within a few hours is exemplified on a MF test proving the specific reaction to anti-chicken bursa cell sera (ABS) and antichicken thymus cell sera (ATS) on bursa and thymus cells respectively. The possible value of the new method for the further standardization of immunofluorescence is also emphasized.

Animals↗
PubMed1976

Visualization of type I and II collagens in tissue sections by immunohistologic techniques.

Rabbit and rat antibodies were prepared against Type I and II collagens derived from bovine skin and articular cartilage, respectively. As judged by passive hemagglutination and radioimmune assays, these antibodies could be rendered generally specific for the type of collagen used for immunization by immunoadsorption. Thus, antibodies to Type II collagen did not cross-react with Type I and III collagens from skin. However, antibodies to Type I collagen still showed some cross-reaction with Type III collagen. Antibodies to Type I procollagen showed a negligible degree of cross-reaction with Type III procollagen. These purified antibodies reacted strongly with bovine and human tissue collagen as demonstrated by indirect immunoflourescence. Antibodies to Type I collagen stained dermal tissue, perichondral tissue, kidney stroma, aortic tissue, and annulus fibrosus. Antibodies to Type II collagen stained mainly the hyaline matrix of rib cartilage and nucleus pulposus. The staining patterns with anti-Type I procollagen were similar but not identical to that found with antibodies to Type I collagen. Neither of these antibodies reacted with kidney glomerular basement membrane. These antibody reagents are recommended as a sensitive and rapid screening tool for studying tissue distribution of collagen under normal and pathologic conditions.

Animals↗
PubMed1976

[Immunological studies in childhood coeliac disease (author's transl)].

The predominance of IgA-containing plasma cells over IgM-containing plasma cells in the normal small bowel mucosa is well documented. In coeliac patients relatively higher numbers of IgM-positive cells were found by several authors in varying degrees. We investigated the proportion of IgA-, IgM and IgG- containing plasma cells in small bowel biopsy material from 21 coeliac children and 24 controls by means of the immunofluorescent double-staining technique. A greater increase of IgM-cells than has previously been described was found. Additionally anti-reticulin antibodies, precipitating antibodies to gliadin and immunoglobuline levels in the serum were determined and tissue typing was performed in a number of these children, and the correlations of these single results were studied. Although these immunological investigations can not substitute the examination of small bowel mucosa biopsies by means of the dissecting microscope and conventional histological methods, they are a valuable diagnostic aid and could help to avoid unnecessary repeat biopsies. They are of help in monitoring the course and therapy in coeliac patients.

Adolescent↗
PubMed1976

Production and diagnostic application of anti-human T-cell antisera.

This paper is intended to demonstrate the extension of experimental procedures used for the production of anti-chicken T-cell sera to the manufacturing of anti-human T-cell sera. Specific anti-chicken bursa (ABS) and anti-chicken thymus cell sera (ATS) were prepared in turkeys. The in vitro specificity of these sera was assessed by means of immunofluorescence and lymphocytotoxicity tests. The selective immunosuppressive effect of ABS was demonstrated in Obese strain (OS) chickens with spontaneous autoimmune thyroiditis, that of ATS in a skin allograft system. A specific anti-human T-cell serum was prepared by immunizing a horse with fetal human thymus cells. After appropriate exhaustive absorptions this serum was found to react specifically with human T-cells. An anti-T cell globulin (ATG) fraction prepared from the absorbed antiserum was then labelled with FITC for use in direct immunofluorescence tests. The potential diagnostic value of T-cell specific antibodies is discussed.

Animals↗
PubMed1976

Increased iodine uptake by obese strain thyroid glands transplanted to normal chick embryos.

The Obese strain (OS) of chickens spontaneously develops autoimmune thyroiditis. Since a defect or abnormality of the thyroid gland may be involved in this disease experiments were performed to compare the iodine uptake of OS with normal thyroid glands. To minimize the interaction of the OS immune system with the thyroid gland during these studies, thyroids were removed from 16-day-old embryos and transferred to the chorioallantoic membrane (CAM) of 9-day-old normal White Leghorn (NWL) embryos. NWL thyroid glands were transferred to the same CAM. Six days later the 20-hr 131I uptake of the transplants was determined. Twenty OS thyroid lobes had a mean 131I uptake of 2960 +/- 740 cpm, whereas the NWL thyroids incorporated significantly less iodine (890 +/- 160 cpm; p less than 0.025). These results, along with a previous report suggest that an abnormality of the thyroid gland might be an important factor in the development of autoimmune thyroiditis.

Animals↗
PubMed1976

Antigenic relationship between chicken brain and granulocytes.

Antisera prepared in rabbits and turkeys against chicken brain were tested in membrane immunofluorescence and lymphocytotoxicity tests for their reactivity with thymocytes and cells from the bursa of Fabricius of normal White Leghorn chickens. In contrast to the findings in mice and other mammals, these antisera did not afford any specific reaction with thymus cells after exhaustive absorptions of species specific antibodies with cells from various tissues. However, absorbed rabbit antisera could be shown to react specifically with cells from the granulocytic series in the bone marrow and, to a lesser extent, in the peripheral blood of chickens.

Animals↗