TY - JOUR A1 - Ulrichs, Karin A1 - Kuhlencordt, KM A1 - Müller-Ruchholtz, W. T1 - Plating inhibition assay (PIA): a new test for cell mediated cytotoxicity N2 - No abstract available Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45443 ER - TY - JOUR A1 - Ulrichs, Karin A1 - Deltz, E. A1 - Thiede, A. A1 - Müller-Ruchholtz, W. T1 - Lymphoid tissue transplantation in rats leads to a GVHR, inducing a specific T-cell mediated autoreactivity against MHC-antigens N2 - No abstract available Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45420 ER - TY - JOUR A1 - Ulrichs, Karin A1 - Müller-Buchholtz, W. T1 - MHC class II antigen expression on the various cells of normal and activated isolated pancreatic islets N2 - It is the aim of this study to characterize and quantify the cells within isolated rat islets that express MHC class 11 antigens. A set of five monoelonal antibodies and two polyclonal antisera of defined specificlty were used in combination with a newly devised procedure for three·dimensional immunofluorescence evaluation of intact islets. It is shown that in addition to passen· ger cells, such as Iymphocytes, macro· phages, and dendrlticlike cells, vascular endothelial and endocrine cells are also capable of expressing class 11 antigens. This expression Is strongly influenced by in vitro culture. pregnancy, streptozotocin- induced diabetes, transplantation trauma, and alloantigenic stimuli. The pos· sible role of the above cells in antigen presentation related to islet transplantation is discussed. KW - pancreas Islets KW - beta cells KW - islet transplantation KW - la antigens Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44722 ER - TY - JOUR A1 - Ulrichs, Karin A1 - Schang, T. A1 - Keller, R. A1 - Müller-Ruchholtz, W. T1 - Reactivity of pancreas islet cells with antisera of known specificity N2 - No abstract available Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45466 ER - TY - JOUR A1 - Engemann, R. A1 - Gassel, HJ A1 - Ulrichs, Karin A1 - Thiede, A. A1 - Hamelmann, H. T1 - Suppressorzellmechanismen nach Cyclosporin A (CsA) induzierter Toleranz allogener Rattenlebertransplantate T1 - Suppressor cell mechanisms after cyclosporin A (CsA) induced tolerance of allogeneic rat liver transplants N2 - No abstract available Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45503 ER - TY - JOUR A1 - Heiser, A. A1 - Ulrichs, Karin A1 - Müller-Ruchholtz, W. T1 - Prophylactic trypsin inhibition during the isolation procedure guarantees reproducible, high porcine islet yields N2 - Abstract: For isolating islets from the porcine pancreas, we established a semiautomated digestion method. Although the isolation technique was standardized and collagenase of controlled quality was used, until now the reproducibility of high islet yields was unsatisfactory. Our hypothesis was that pancreatic trypsin was responsible for this failure. The aim of this study was to investigate the effect of endogenous trypsin on islet yield. Our results demonstrate that a high trypsin level correlates with poor islet yield, whereas low trypsin activity always correlates with high islet yield. Specific inhibition of trypsin results in low trypsin activity and reproducible, high islet yields. KW - islets of Langerhans KW - xenogenic transplantation KW - swine KW - enzyme activation KW - enzyme inhibitors Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45531 ER - TY - JOUR A1 - Engemann, R. A1 - Ulrichs, Karin A1 - Thiede, A. A1 - Müller-Ruchholtz, W. A1 - Hamelmann, H. T1 - Value of a physiological liver transplant model in rats. Induction of specific graft tolerance in a fully allogeneic strain combination N2 - No abstract available Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45622 ER - TY - JOUR A1 - Ulrichs, Karin A1 - Yu, MY A1 - Duncker, D. A1 - Müller-Ruchholtz, W. T1 - Immunosuppression by cytostatic drugs? N2 - In the present study, an attempt was made to characterize the immunomodulating abilities of the cytostatic drugs cydophosphamide, ifosfamide, vinblastine, vincristine, procarbazine, dacarbazine, 6-mercaptopurine, methotrexate, 5-f/uor-uracil and adriamycine in a defined experimental model. Varying combinations of drug plus transplantation alloantigen, (C3H-lymphocytes) were injected into Balb/c mice at different time intervals in vivo. The resulting T-effector cell reactivity was determined in vitro with the microcytotoxicity assay on day + 5 for primary (r) and day + 7 for secondary (2°) sensitized mice. According to the type of drug (alkylating agent vs. vinca alkaloid vs. antimetabolite vs. cytostatic antibiotic), the dosage (20% LD50 vs. 60% LD50), the state of sensitization (r vs. 2° sensitized recipients), and the time of drug application in relation to the antigen treatment on day 0 (in varying steps from day -6 to day +4), so-called "pharmaconantigen- variation-effects" (PA VE) were established for each of the investigated drugs in form of reaction profiles. The results were as folIows: (1) For almost alt substances, characteristic reaction profiles involving immunostimulation and/or immunosuppression could be established. Similarities in the profiles of different substances made it possible to classify the drugs according to different reaction types. The reaction type however is not definitely correlated to the biochemical mechanism of drug action. (2) The PA VE are decisively inf/uenced by so me of the biological parameters, such as the time of drug application in relation to the antigen treatment and the state of sensitization but relatively !ittle by the dosage of the drug. (3) Considering the different processes occurring du ring primary and secondary immune responses, the PAVE may give hints for a distinct manipulation of the immunoregulation and thus information on the immunobiological mechanism of drug action. KW - Immunologie Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45574 ER - TY - JOUR A1 - Winoto-Morbach, Supandi A1 - Ulrichs, Karin A1 - Leyhausen, Gaby A1 - Müller-Ruchholtz, Wolfgang T1 - New principle for large-scale preparation of purified human pancreas islets N2 - Because successful human islet transplantation requires large quantities of viable islets that must be separated from the highly immunogenic exocrine tissue and because handpicking is too time-consuming and laborious to be clinically relevant, a new approach for solving this problem has been established in rat models. It is based on the principle that magnetic microspheres (MMSs) coupled to lectins with binding specificity for the exocrine tissue portion are trapped in an electromagnetic field, thus providing effluent islets of a high degree of purity. In this study our aim was to adapt this princip'le to human islet preparations. In this context our prime interest was focused on a lectin suitable for human pancreatic tissue. Of 19 different lectins tested, only 1, Wisteria floribunda agglutinin (WFA), is suitable, as shown by immunofluorescence, MMS-Iectin binding, and magnetic separation KW - Immunbiologie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45600 ER - TY - JOUR A1 - Von Gaudecker, Brita A1 - Ulrichs, Karin A1 - Müller-Ruchholtz, Wolfgang T1 - Immunoelectron microscopic localization of MHC structures in isolated pancreatic rat islets N2 - An immunogold-silver enhancement technique, which combines effective labeling of viable isolated islets with the ultrastructural resolution of cytological details, was applied in electron microscopy to identify major histocompatibility complex (MHC) structures on islet cells. Incubation of freshly isolated islets from CAP (RT1C) and LEW (RT1') rats with OX18, an MHC class I antibody, showed strong positive reactivity in macrophages and/or dendritic-like cells (M0-DCs) and vascular endothelial cells (VEs) and a comparatively weaker reactivity in endocrine a-, p-, and 8-ce"s. With MHC class" antibody OX6 (anti-I-A), M0-DCs were strongly labeled in both rat strains on the surface and on internal structures. Three of five particularly high titered batches of OX6 revealed MHC class" expression on VE and p-ce"s. Four days of in vitro culture in combination with a high concentration of glucose and interferon-'Y induced strong enhancement of MHC class I structures and, to a lesser extent, class " structures on p-ce"s. KW - Immunbiologie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45596 ER -