@phdthesis{Kleffel2018, author = {Kleffel, Sonja Beate}, title = {The role of cancer cell-expressed PD-1 in tumorigenesis and tumor immune evasion}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151205}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2018}, abstract = {Melanoma and Merkel cell carcinoma (MCC) are highly aggressive cancers of the skin that frequently escape immune recognition and acquire resistance to chemotherapeutic agents, which poses a major obstacle to successful cancer treatment. Recently, a new class of therapeutics targeting the programmed cell death-1 (PD-1) immune checkpoint receptor has shown remarkable efficacy in the treatment of both cancers. Blockade of PD-1 on T cells activates cancer-specific immune responses that can mediate tumor regression. The data presented in this Ph.D. thesis demonstrates that PD-1 is also expressed by subsets of cancer cells in melanoma and MCC. Moreover, this work identifies PD-1 as a novel tumor cell-intrinsic growth receptor, even in the absence of T cell immunity. PD-1 is expressed by tumorigenic cell subsets in melanoma patient samples and established human and murine cell lines that also co-express ABCB5, a marker of immunoregulatory tumor- initiating cells in melanoma. Consistently, melanoma-expressed PD-1 downmodulates T effector cell functions and increases the intratumoral frequency of tolerogenic myeloid- derived suppressor cells. PD-1 inhibition on melanoma cells by RNA interference, blocking antibodies, or mutagenesis of melanoma-PD-1 signaling motifs suppresses tumor growth in immunocompetent, immunocompromised, and PD-1-deficient tumor graft recipient mice. Conversely, melanoma-specific PD-1 overexpression enhances tumorigenicity, including in mice lacking adaptive immunity. Engagement of melanoma- PD-1 by its ligand PD-L1 promotes tumor growth, whereas melanoma-PD-L1 inhibition or knockout of host-PD-L1 attenuates growth of PD-1-positive melanomas. Mechanistically, the melanoma-PD-1 receptor activates mTOR signaling mediators, including ribosomal protein S6. In a proof-of-concept study, tumoral expression of phospho-S6 in pretreatment tumor biopsies correlated with clinical responses to anti-PD-1 therapy in melanoma patients. In MCC, PD-1 is similarly co-expressed by ABCB5+ cancer cell subsets in clinical tumor specimens and established human cell lines. ABCB5 renders MCC cells resistant to the standard-of-care chemotherapeutic agents, carboplatin and etoposide. Antibody-mediated ABCB5 blockade reverses chemotherapy resistance and inhibits tumor xenograft growth by enhancing chemotherapy-induced tumor cell killing. Furthermore, engagement of MCC-expressed PD-1 by its ligands, PD-L1 and PD-L2, promotes proliferation and activates MCC-intrinsic mTOR signaling. Consistently, antibody- mediated PD-1 blockade inhibits MCC tumor xenograft growth and phosphorylation of mTOR effectors in immunocompromised mice. In summary, these findings identify cancer cell-intrinsic functions of the PD-1 pathway in tumorigenesis and suggest that blocking melanoma- and MCC-expressed PD-1 might contribute to the striking clinical efficacy of anti-PD-1 therapy. Additionally, these results establish ABCB5 as a previously unrecognized chemoresistance mechanism in MCC.}, subject = {Melanom}, language = {en} } @article{BuschBuschScholzetal.2016, author = {Busch, Albert and Busch, Martin and Scholz, Claus-J{\"u}rgen and Kellersmann, Richard and Otto, Christoph and Chernogubova, Ekaterina and Maegdefessel, Lars and Zernecke, Alma and Lorenz, Udo}, title = {Aneurysm miRNA Signature Differs, Depending on Disease Localization and Morphology}, series = {International Journal of Molecular Science}, volume = {17}, journal = {International Journal of Molecular Science}, number = {1}, issn = {International Journal of Molecular Science}, doi = {10.3390/ijms17010081}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146422}, pages = {81}, year = {2016}, abstract = {Limited comprehension of aneurysm pathology has led to inconclusive results from clinical trials. miRNAs are key regulators of post-translational gene modification and are useful tools in elucidating key features of aneurysm pathogenesis in distinct entities of abdominal and popliteal aneurysms. Here, surgically harvested specimens from 19 abdominal aortic aneurysm (AAA) and 8 popliteal artery aneurysm (PAA) patients were analyzed for miRNA expression and histologically classified regarding extracellular matrix (ECM) remodeling and inflammation. DIANA-based computational target prediction and pathway enrichment analysis verified our results, as well as previous ones. miRNA-362, -19b-1, -194, -769, -21 and -550 were significantly down-regulated in AAA samples depending on degree of inflammation. Similar or inverse regulation was found for miR-769, 19b-1 and miR-550, -21, whereas miR-194 and -362 were unaltered in PAA. In situ hybridization verified higher expression of miR-550 and -21 in PAA compared to AAA and computational analysis for target genes and pathway enrichment affirmed signal transduction, cell-cell-interaction and cell degradation pathways, in line with previous results. Despite the vague role of miRNAs for potential diagnostic and treatment purposes, the number of candidates from tissue signature studies is increasing. Tissue morphology influences subsequent research, yet comparison of distinct entities of aneurysm disease can unravel core pathways.}, language = {en} } @article{WedelHudakSeibeletal.2011, author = {Wedel, Steffen and Hudak, Lukasz and Seibel, Jens-Michael and Makarevic, Jasmina and Juengel, Eva and Tsaur, Igor and Waaga-Gasser, Ana and Haferkamp, Axel and Blaheta, Roman A.}, title = {Molecular targeting of prostate cancer cells by a triple drug combination down-regulates integrin driven adhesion processes, delays cell cycle progression and interferes with the cdk-cyclin axis}, series = {BMC Cancer}, volume = {11}, journal = {BMC Cancer}, number = {375}, doi = {10.1186/1471-2407-11-375}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141075}, pages = {1-14}, year = {2011}, abstract = {Background: Single drug use has not achieved satisfactory results in the treatment of prostate cancer, despite application of increasingly widespread targeted therapeutics. In the present study, the combined impact of the mammalian target of rapamycin (mTOR)-inhibitor RAD001, the dual EGFr and VGEFr tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC)-inhibitor valproic acid (VPA) on prostate cancer growth and adhesion in vitro was investigated. Methods: PC-3, DU-145 and LNCaP cells were treated with RAD001, AEE788 or VPA or with a RAD-AEE-VPA combination. Tumor cell growth, cell cycle progression and cell cycle regulating proteins were then investigated by MTT-assay, flow cytometry and western blotting, respectively. Furthermore, tumor cell adhesion to vascular endothelium or to immobilized extracellular matrix proteins as well as migratory properties of the cells was evaluated, and integrin alpha and beta subtypes were analyzed. Finally, effects of drug treatment on cell signaling pathways were determined. Results: All drugs, separately applied, reduced tumor cell adhesion, migration and growth. A much stronger anticancer effect was evoked by the triple drug combination. Particularly, cdk1, 2 and 4 and cyclin B were reduced, whereas p27 was elevated. In addition, simultaneous application of RAD001, AEE788 and VPA altered the membranous, cytoplasmic and gene expression pattern of various integrin alpha and beta subtypes, reduced integrin-linked kinase (ILK) and deactivated focal adhesion kinase (FAK). Signaling analysis revealed that EGFr and the downstream target Akt, as well as p70S6k was distinctly modified in the presence of the drug combination. Conclusions: Simultaneous targeting of several key proteins in prostate cancer cells provides an advantage over targeting a single pathway. Since strong anti-tumor properties became evident with respect to cell growth and adhesion dynamics, the triple drug combination might provide progress in the treatment of advanced prostate cancer.}, language = {en} } @article{JurowichOttoRikkalaetal.2015, author = {Jurowich, Christian Ferdinand and Otto, Christoph and Rikkala, Prashanth Reddy and Wagner, Nicole and Vrhovac, Ivana and Sabolić, Ivan and Germer, Christoph-Thomas and Koepsell, Hermann}, title = {Ileal interposition in rats with experimental type 2 like diabetes improves glycemic control independently of glucose absorption}, series = {Journal of Diabetes Research}, volume = {2015}, journal = {Journal of Diabetes Research}, number = {490365}, doi = {10.1155/2015/490365}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149166}, year = {2015}, abstract = {Bariatric operations in obese patients with type 2 diabetes often improve diabetes before weight loss is observed. In patients mainly Roux-en-Y-gastric bypass with partial stomach resection is performed. Duodenojejunal bypass (DJB) and ileal interposition (IIP) are employed in animal experiments. Due to increased glucose exposition of L-cells located in distal ileum, all bariatric surgery procedures lead to higher secretion of antidiabetic glucagon like peptide-1 (GLP-1) after glucose gavage. After DJB also downregulation of Na\(^{+}\)-D-glucose cotransporter SGLT1 was observed. This suggested a direct contribution of decreased glucose absorption to the antidiabetic effect of bariatric surgery. To investigate whether glucose absorption is also decreased after IIP, we induced diabetes with decreased glucose tolerance and insulin sensitivity in male rats and investigated effects of IIP on diabetes and SGLT1. After IIP, we observed weight-independent improvement of glucose tolerance, increased insulin sensitivity, and increased plasma GLP-1 after glucose gavage. The interposed ileum was increased in diameter and showed increased length of villi, hyperplasia of the epithelial layer, and increased number of L-cells. The amount of SGLT1-mediated glucose uptake in interposed ileum was increased 2-fold reaching the same level as in jejunum. Thus, improvement of glycemic control by bariatric surgery does not require decreased glucose absorption.}, language = {en} } @article{FilserDickMeyeretal.2015, author = {Filser, J{\"o}rg and Dick, Anke and Meyer, Thomas and Germer, Christoph-Thomas and von Rahden, Burkard H. A.}, title = {Peroral endoscopic myotomy for the treatment of achalasia in a 10-year-old male patient.}, series = {European Journal of Pediatric Surgery Reports}, volume = {3}, journal = {European Journal of Pediatric Surgery Reports}, number = {1}, doi = {10.1055/s-0034-1372461}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149502}, pages = {18-22}, year = {2015}, abstract = {Peroral endoscopic myotomy (POEM) is a new endoscopic treatment for achalasia with very good short-term results in adults. Data about POEM in pediatric patients are missing. We present the case of a 10-year-old male patient with type I (classic) achalasia, successfully treated with POEM. The procedure was accomplished in a similar fashion to the technique used in adults. Short-term results were fine, with a complete control of dysphagia and absence of reflux. We suggest that POEM is a suitable option in pediatric patients—similar to adults—but long-term results must be awaited.}, language = {en} } @article{OttoHahlbrockEichetal.2016, author = {Otto, Christoph and Hahlbrock, Theresa and Eich, Kilian and Karaaslan, Ferdi and J{\"u}rgens, Constantin and Germer, Christoph-Thomas and Wiegering, Armin and K{\"a}mmerer, Ulrike}, title = {Antiproliferative and antimetabolic effects behind the anticancer property of fermented wheat germ extract}, series = {BMC Complementary and Alternative Medicine}, volume = {16}, journal = {BMC Complementary and Alternative Medicine}, number = {160}, doi = {10.1186/s12906-016-1138-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146013}, year = {2016}, abstract = {Background Fermented wheat germ extract (FWGE) sold under the trade name Avemar exhibits anticancer activity in vitro and in vivo. Its mechanisms of action are divided into antiproliferative and antimetabolic effects. Its influcence on cancer cell metabolism needs further investigation. One objective of this study, therefore, was to further elucidate the antimetabolic action of FWGE. The anticancer compound 2,6-dimethoxy-1,4-benzoquinone (DMBQ) is the major bioactive compound in FWGE and is probably responsible for its anticancer activity. The second objective of this study was to compare the antiproliferative properties in vitro of FWGE and the DMBQ compound. Methods The IC\(_{50}\) values of FWGE were determined for nine human cancer cell lines after 24 h of culture. The DMBQ compound was used at a concentration of 24 μmol/l, which is equal to the molar concentration of DMBQ in FWGE. Cell viability, cell cycle, cellular redox state, glucose consumption, lactic acid production, cellular ATP levels, and the NADH/NAD\(^+\) ratio were measured. Results The mean IC\(_{50}\) value of FWGE for the nine human cancer cell lines tested was 10 mg/ml. Both FWGE (10 mg/ml) and the DMBQ compound (24 μmol/l) induced massive cell damage within 24 h after starting treatment, with changes in the cellular redox state secondary to formation of intracellular reactive oxygen species. Unlike the DMBQ compound, which was only cytotoxic, FWGE exhibited cytostatic and growth delay effects in addition to cytotoxicity. Both cytostatic and growth delay effects were linked to impaired glucose utilization which influenced the cell cycle, cellular ATP levels, and the NADH/NAD\(^+\) ratio. The growth delay effect in response to FWGE treatment led to induction of autophagy. Conclusions FWGE and the DMBQ compound both induced oxidative stress-promoted cytotoxicity. In addition, FWGE exhibited cytostatic and growth delay effects associated with impaired glucose utilization which led to autophagy, a possible previously unknown mechanism behind the influence of FWGE on cancer cell metabolism.}, language = {en} } @article{LichthardtKerscherDietzetal.2016, author = {Lichthardt, Sven and Kerscher, Alexander and Dietz, Ulrich A. and Jurowich, Christian and Kunzmann, Volker and von Rahden, Burkhard H. A. and Germer, Christoph-Thomas and Wiegering, Armin}, title = {Original article: role of adjuvant chemotherapy in a perioperative chemotherapy regimen for gastric cancer}, series = {BMC Cancer}, volume = {16}, journal = {BMC Cancer}, number = {650}, doi = {10.1186/s12885-016-2708-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147743}, year = {2016}, abstract = {Background Multimodal treatment strategies - perioperative chemotherapy (CTx) and radical surgery - are currently accepted as treatment standard for locally advanced gastric cancer. However, the role of adjuvant postoperative CTx (postCTx) in addition to neoadjuvant preoperative CTx (preCTx) in this setting remains controversial. Methods Between 4/2006 and 12/2013, 116 patients with locally advanced gastric cancer were treated with preCTx. 72 patients (62 \%), in whom complete tumor resection (R0, subtotal/total gastrectomy with D2-lymphadenectomy) was achieved, were divided into two groups, one of which receiving adjuvant therapy (n = 52) and one without (n = 20). These groups were analyzed with regard to survival and exclusion criteria for adjuvant therapy. Results Postoperative complications, as well as their severity grade, did not correlate with fewer postCTx cycles administered (p = n.s.). Long-term survival was shorter in patients receiving postCTx in comparison to patients without postCTx, but did not show statistical significance. In per protocol analysis by excluding two patients with perioperative death, a shorter 3-year survival rate was observed in patients receiving postCTx compared to patients without postCTx (3-year survival: 71.2 \% postCTx group vs. 90.0 \% non-postCTx group; p = 0.038). Conclusion These results appear contradicting to the anticipated outcome. While speculative, they question the value of post-CTx. Prospectively randomized studies are needed to elucidate the role of postCTx.}, language = {en} } @article{BuschHoffjanBergmannetal.2016, author = {Busch, Albert and Hoffjan, Sabine and Bergmann, Frauke and Hartung, Birgit and Jung, Helena and Hanel, Daniela and Tzschach, Andeas and Kadar, Janos and von Kodolitsch, Yskert and Germer, Christoph-Thomas and Trobisch, Heiner and Strasser, Erwin and Wildenauer, Ren{\´e}}, title = {Vascular type Ehlers-Danlos syndrome is associated with platelet dysfunction and low vitamin D serum concentration}, series = {Orphanet Journal of Rare Diseases}, volume = {11}, journal = {Orphanet Journal of Rare Diseases}, number = {111}, doi = {10.1186/s13023-016-0491-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147757}, year = {2016}, abstract = {Background The vascular type represents a very rare, yet the clinically most fatal entity of Ehlers-Danlos syndrome (EDS). Patients are often admitted due to arterial bleedings and the friable tissue and the altered coagulation contribute to the challenge in treatment strategies. Until now there is little information about clotting characteristics that might influence hemostasis decisively and eventually worsen emergency situations. Results 22 vascular type EDS patients were studied for hemoglobin, platelet volume and count, Quick and activated partial thromboplastin time, fibrinogen, factor XIII, von Willebrand disease, vitamin D and platelet aggregation by modern standard laboratory methods. Results show a high prevalence of over 50 \% for platelet aggregation disorders in vascular type EDS patients, especially for collagen and epinephrine induced tests, whereas the plasmatic cascade did not show any alterations. Additionally, more than half of the tested subjects showed low vitamin D serum levels, which might additionally affect vascular wall integrity. Conclusion The presented data underline the importance of detailed laboratory screening methods in vascular type EDS patients in order to allow for targeted application of platelet-interacting substances that might be of decisive benefit in the emergency setting.}, language = {en} } @article{KrajinovicReimerKudlichetal.2016, author = {Krajinovic, K. and Reimer, S. and Kudlich, T. and Germer, C. T. and Wiegering, A.}, title = {"Rendezvous technique" for intraluminal vacuum therapy of anastomotic leakage of the jejunum}, series = {Surgical Case Reports}, volume = {2}, journal = {Surgical Case Reports}, number = {114}, doi = {10.1186/s40792-016-0243-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147883}, year = {2016}, abstract = {Background Anastomotic leakage (AL) is one of the most common and serious complications following visceral surgery. In recent years, endoluminal vacuum therapy has dramatically changed therapeutic options for AL, but its use has been limited to areas easily accessible by endoscope. Case presentation We describe the first use of endoluminal vacuum therapy in the small intestine employing a combined surgical and endoscopic "rendezvous technique" in which the surgeon assists the endoscopic placement of an endoluminal vacuum therapy sponge in the jejunum by means of a pullback string. This technique led to a completely closed AL after 27 days and 7 changes of the endosponge. Conclusion The combined surgical and endoscopic rendezvous technique can be useful in cases of otherwise difficult endosponge placement.}, language = {en} } @article{BaurRitterGermeretal.2016, author = {Baur, Johannes and Ritter, Christian O. and Germer, Christoph-Thomas and Klein, Ingo and Kickuth, Ralph and Steger, Ulrich}, title = {Transarterial chemoembolization with drug-eluting beads versus conventional transarterial chemoembolization in locally advanced hepatocellular carcinoma}, series = {Hepatic Medicine}, volume = {2016}, journal = {Hepatic Medicine}, number = {8}, doi = {10.2147/HMER.S105395}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146553}, pages = {69-74}, year = {2016}, abstract = {Purpose: In hepatocellular carcinoma patients with large or multinodal tumors, where curative treatment options are not feasible, transarterial therapies play a major role. Transarterial chemoembolization (TACE) with drug-eluting beads (DEB-TACE) is a promising new approach due to higher intratumoral and lower systemic concentration of the chemotherapeutic agent compared to conventional TACE (cTACE). Patients and methods: In a retrospective analysis, 32 patients with hepatocellular carcinoma who received either DEB or a cTACE were compared regarding survival time, disease recurrence, and side effects such as pain and fever. Results: No significant differences could be detected between the cTACE and DEB-TACE groups with regard to mean hospital stay, appearance of postinterventional fever, or 30-day mortality. However, the application of intravenous analgesics as postinterventional pain medication was needed more often in patients treated with DEB-TACE (57.1\% vs 12.5\%, P=0.0281). The overall median survival after the initial procedure was 10.8 months in the cTACE group and 9.2 months in the DEB-TACE group, showing no significant difference. Conclusion: No survival benefit for patients treated with either DEB-TACE or cTACE was observed. Surprisingly, a higher rate of postinterventional pain could be detected after DEB-TACE.}, language = {en} } @article{MoenchGrimmigKannenetal.2016, author = {Moench, Romana and Grimmig, Tanja and Kannen, Vinicius and Tripathi, Sudipta and Faber, Marc and Moll, Eva-Maria and Chandraker, Anil and Lissner, Reinhard and Germer, Christoph-Thomas and Waaga-Gasser, Ana Maria and Gasser, Martin}, title = {Exclusive inhibition of PI3K/Akt/mTOR signaling is not sufficient to prevent PDGF-mediated effects on glycolysis and proliferation in colorectal cancer}, series = {Oncotarget}, volume = {7}, journal = {Oncotarget}, number = {42}, doi = {10.18632/oncotarget.11899}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176910}, pages = {68749-68767}, year = {2016}, abstract = {Platelet-derived growth factor (PDGF) and signaling via its receptors plays a crucial role in tumor cell proliferation and thus may represent an attractive target besides VEGF/EGFR-based antibody therapies. In this study we analyzed the influence of PDGF in colorectal cancer. PDGF was expressed intensively in early and even more intensively in late stage primary CRCs. Like VEGF, PDGF enhanced human colon cancer proliferation, and increased oxidative glycolytic activity, and activated HIF1α and c-Myc in vitro. PDGF activated the PI3K/Akt/mTOR pathway while leaving MAPK signaling untouched. Further dissection showed that inhibition of Akt strongly impeded cancer cell growth while inhibition of PI3K did not. MAPK analysis suggested an inhibitory crosstalk between both pathways, thus explaining the different effects of the Akt and PI3K inhibitors on cancer cell proliferation. PDGF stimulates colon cancer cell proliferation, and prevents inhibitor induced apoptosis, resulting in tumor growth. Therefore inhibition of PDGF signaling seems to be a promising target in colorectal cancer therapy. However, due to the multifaceted nature of the intracellular PDGF signaling, careful intervention strategies are needed when looking into specific signaling pathways like PI3K/Akt/mTOR and MAPK.}, language = {en} } @article{vonRahdenKircherLazariotouetal.2011, author = {von Rahden, Burkhard H. A. and Kircher, Stefan and Lazariotou, Maria and Reiber, Christoph and Stuermer, Luisa and Otto, Christoph and Germer, Christoph T. and Grimm, Martin}, title = {LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68810}, year = {2011}, abstract = {Background: Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis. Materials and methods: Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates. Results: LgR5was found expressed in 35 of 41 (85\%) EAC with BE and in 16 of 19 (81\%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15\% LgR5+ cells in EAC with BE, 32\% LgR5+ cells in adjacent BE and 13\% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5\%) of proliferating LgR+/Ki-67+ cells. On mRNAlevel, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis. Conclusion: The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5\%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.}, subject = {Medizin}, language = {en} } @article{KrannichThereseBroscheitetal.2012, author = {Krannich, Jens-Holger and Therese, Tobias and Broscheit, Jens and Leyh, Rainer and M{\"u}llges, Wolfgang}, title = {Diabetes severely affects attentional performance after coronary artery bypass grafting}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75320}, year = {2012}, abstract = {Background: Diabetes is a risk factor for (micro) vascular damage of the brain, too. Therefore cognitive performance after coronary artery bypass grafting may be hypothesized worse in diabetics. To avoid observational errors a reliable tool for testing attentional performance was used. We evaluated whether diabetes mellitus disposes to distinct cognitive dysfunction after coronary artery bypass grafting (CABG). Methods: Three aspects in attentional performance were prospectively tested with three different tests (alertness: composed of un-cued and cued reaction, divided attention, and selective attention) by a computerized tool one day before and seven days after CABG in a highly selected cohort of 30 males, 10 of whom had diabetes. Statistical comparisons were done with analysis of variance for repeated measurements and Fisher´s LSD. Results: Prior to CABG there was no statistically meaningful difference between diabetics and non-diabetics. Postoperatively, diabetic patients performed significantly worse than non-diabetics in tests for un-cued (p=0.01) and cued alertness (p=0.03). Test performance in divided attention was worse after CABG but independent of diabetes status. Selective attention was neither affected by diabetes status nor by CABG itself. Conclusions: Diabetes may have an impact on cognitive performance after CABG. More severe deficits in alertness may point to underlying microvascular disease.}, subject = {Medizin}, language = {en} } @article{KlingelhoefferKaemmererKoospaletal.2012, author = {Klingelhoeffer, Chr{\´i}stoph and K{\"a}mmerer, Ulrike and Koospal, Monika and M{\"u}hling, Bettina and Schneider, Manuela and Kapp, Michaela and K{\"u}bler, Alexander, and Germer, Christoph-Thomas and Otto, Christoph}, title = {Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75142}, year = {2012}, abstract = {Background: Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods: Effective concentration (EC50) values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50\%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA) in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results: The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50>20 mmol/L and fifty-five percent had an EC50<20 mmol/L. With an EC50 of 2.6-5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L), was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT) became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L). Conclusions: Fifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.}, subject = {Medizin}, language = {en} } @article{StraussMoskalenkoTiurbeetal.2012, author = {Strauss, Armin and Moskalenko, Vasily and Tiurbe, Christian and Chodnevskaja, Irina and Timm, Stephan and Wiegering, Verena A. and Germer, Chrioph Thomas and Ulrichs, Karin}, title = {Goettingen Minipigs (GMP): Comparison of Two Different Models for Inducing Diabetes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75119}, year = {2012}, abstract = {Purpose: Preclinical experiments on large animals are indispensable for evaluating the effectiveness of diabetes therapies. Miniature swine are well suited for such studies due to their physiological and pathophysiological responses. Methods: We compare two methods for inducing diabetes in Goettingen minipigs (GMP), in five with the beta cell toxin streptozotocin (STZ) and in five other GMP by total pancreatectomy (PE). Glucose homeostasis was assessed with the intravenous glucose-tolerance test (IVGTT) and continual monitoring of interstitial glucose levels. At conclusion of the observation period, the pancreata were examined histologically. Three non-diabetic GMP served as control group. Results: The IVGTT revealed markedly diabetic profiles in both GMP groups. STZ-GMP were found to harbor residual C-peptides and scattered insulin-positive cells in the pancreas. PE-GMP survived the total pancreatectomy only with intensive postoperative care. Conclusions: Although both methods reliably induced diabetes in GMP, the PE-GMP clearly had more health problems and required a greater expenditure of time and resources. The PE-GMP model, however, was better at eliminating endogenous insulin and C-peptide than the STZ-GMP model.}, subject = {G{\"o}ttingen}, language = {en} } @article{GeissingerSadlerRothetal.2010, author = {Geissinger, Eva and Sadler, Petra and Roth, Sabine and Grieb, Tina and Puppe, Bernhard and Mueller, Nora and Reimer, Peter and Vetter-Kauczok, Claudia S. and Wenzel, Joerg and Bonzheim, Irina and Ruediger, Thomas and Mueller-Hermelink, Hans Konrad and Rosenwald, Andreas}, title = {Disturbed expression of the T-cell receptor/CD3 complex and associated signaling molecules in CD30(+) T-cell lymphoproliferations}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68179}, year = {2010}, abstract = {Background CD30+ T-cell lymphoproliferations comprise a spectrum of clinically heterogeneous entities, including systemic anaplastic large cell lymphomas (ALK- and ALK+) and primary cutaneous CD30+ T-cell lymphoproliferative disorders. While all these entities are characterized by proliferation of highly atypical, anaplastic CD30+ T cells, the expression of T-cell specific antigens in the tumor cells is not consistently detectable. Design and Methods We evaluated biopsies from 19 patients with primary cutaneous CD30+ lymphoproliferative disorders, 38 with ALK- and 33 with ALK+ systemic anaplastic large cell lymphoma. The biopsies were examined for the expression of T-cell receptoraβ/CD3 complex (CD3γ, δ, ε, ζ), transcription factors regulating T-cell receptor expression (ATF1, ATF2, TCF-1, TCF-1a/LEF-1, Ets1), and molecules of T-cell receptor-associated signaling cascades (Lck, ZAP-70, LAT, bcl-10, Carma1, NFATc1, c-Jun, c-Fos, Syk) using immunohistochemistry. Results In comparison to the pattern in 20 peripheral T-cell lymphomas, not otherwise specified, we detected a highly disturbed expression of the T-cell receptor/CD3 complex, TCF-1, TCF- 1a/LEF-1, Lck, ZAP-70, LAT, NFATc1, c-Jun, c-Fos and Syk in most of the systemic anaplastic large cell lymphomas. In addition, primary cutaneous CD30+ lymphoproliferative disorders showed such a similar expression pattern to that of systemic anaplastic large cell lymphomas, that none of the markers we investigated can reliably distinguish between these CD30+ T-cell lymphoproliferations. Conclusions Severely altered expression of the T-cell receptor/CD3 complex, T-cell receptor-associated transcription factors and signal transduction molecules is a common characteristic of systemic and cutaneous CD30+ lymphoproliferations, although the clinical behavior of these entities is very different. Since peripheral T-cell lymphomas, not otherwise specified retain the full expression program required for functioning T-cell receptor signaling, the differential expression of a subset of these markers might be of diagnostic utility in distinguishing peripheral T-cell lymphomas, not otherwise specified from the entire group of CD30+ lymphoproliferations.}, subject = {Medizin}, language = {en} } @article{GattenloehnerEtschmannKunzmannetal.2010, author = {Gattenl{\"o}hner, S. and Etschmann, B. and Kunzmann, V. and Thalheimer, A. and Hack, M. and Kleber, G. and Einsele, H. and Germer, C. and M{\"u}ller-Hermelink, H.-K.}, title = {Concordance of KRAS/BRAF Mutation Status in Metastatic Colorectal Cancer before and after Anti-EGFR Therapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68240}, year = {2010}, abstract = {Anti-EGFR targeted therapy is a potent strategy in the treatment of metastatic colorectal cancer (mCRC) but activating mutations in the KRAS gene are associated with poor response to this treatment. Therefore, KRAS mutation analysis is employed in the selection of patients for EGFR-targeted therapy and various studies have shown a high concordance between the mutation status in primary CRC and corresponding metastases. However, although development of therapy related resistance occurs also in the context of novel drugs such as tyrosine kinase-inhibitors the effect of the anti-EGFR treatment on the KRAS/BRAF mutation status itself in recurrent mCRC has not yet been clarified. Therefore, we analyzed 21mCRCs before/after anti-EGFR therapy and found a pre-/posttherapeutic concordance of the KRAS/BRAF mutation status in 20 of the 21 cases examined. In the one discordant case, further analyses revealed that a tumor mosaicism or multiple primary tumors were present, indicating that anti-EGFR therapy has no influence on KRAS/BRAF mutation status in mCRC. Moreover, as the preselection of patients with a KRASwt genotype for anti-EGFR therapy has become a standard procedure, sample sets such ours might be the basis for future studies addressing the identification of potential anti-EGFR therapy induced genetic alterations apart from KRAS/BRAF mutations.}, subject = {Krebs}, language = {en} } @article{GrimmLazariotouKircheretal.2010, author = {Grimm, Martin and Lazariotou, Maria and Kircher, Stefan and Stuermer, Luisa and Reiber, Christoph and Hoefelmayr, Andreas and Gattenloehner, Stefan and Otto, Christoph and Germer, Christoph T. and von Rahden, Burkhard H. A.}, title = {MMP-1 is a (pre-)invasive factor in Barrett-associated esophageal adenocarcinomas and is associated with positive lymph node status}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68293}, year = {2010}, abstract = {Background: Esophageal adenocarcinomas (EACs) arise due to gastroesophageal reflux, with Barrett's esophagus (BE) regarded as precancerous lesion. Matrix metalloproteinases (MMPs) might play a role during the multistep carcinogenetic process. Methods: Expression of MMP-1 and -13 was analyzed in esophageal cancer (n = 41 EAC with BE, n = 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC), furthermore in BE without intraepithelial neoplasia (IN) (n = 18), and the cell line OE-33. MMP-1 was co-labelled with Ki-67 (proliferation), Cdx-2 (marker for intestinal metaplasia, BE) and analyzed on mRNA level. MMP-1 staining results were correlated with clinicopatholocical parameters. Results: On protein level, MMP-1 expression was found in 39 of 41 (95\%) EAC with BE, in 19 of 19 (100\%) EAC without BE, in 6 of 10 (60\%) ESCC, and in 10 of 18 (56\%) BE without IN. No expression of MMP-13 was found in these specimens. Quantification showed 48\% MMP-1 positive cells in EAC with BE, compared to 35\% in adjacent BE (p < 0.05), 44\% in EAC without BE, 32\% in ESCC, and 4\% in BE without IN. Immunofluorescence double staining experiments revealed increased MMP-1 expressing in proliferating cells (MMP-1+/Ki-67+) (r = 0.943 for BE and r = 0.811 for EAC). On mRNA-level, expression of MMP-1 was significantly higher in EAC compared to BE (p = 0.01) and confirmed immunohistochemical staining results. High MMP-1 levels were associated with lymph node metastases but not with poorer survival (p = 0.307). Conclusions: Our findings suggest that MMP-1 plays a role as preinvasive factor in BE-associated EAC. Expression of MMP-1 in proliferating BE and EAC cells suggest malignant proliferation following the clonal expansion model.}, subject = {Medizin}, language = {en} } @article{GattenloehnerJoerissenHuhnetal.2010, author = {Gattenloehner, Stefan and Joerissen, H. and Huhn, M. and Vincent, A. and Beeson, D. and Tzartos, S. and Mamalaki, A. and Etschmann, B. and Muller-Hermelink, H. K. and Koscielniak, E. and Barth, S. and Marx, A.}, title = {A Human Recombinant Autoantibody-Based Immunotoxin Specific for the Fetal Acetylcholine Receptor Inhibits Rhabdomyosarcoma Growth In Vitro and in a Murine Transplantation Model [Research Article]}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68200}, year = {2010}, abstract = {Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children and is highly resistant to all forms of treatment currently available once metastasis or relapse has commenced. As it has recently been determined that the acetylcholine receptor (AChR) γ-subunit, which defines the fetal AChR (fAChR) isoform, is almost exclusively expressed in RMS post partum, we recombinantly fused a single chain variable fragment (scFv) derived from a fully human anti-fAChR Fab-fragment to Pseudomonas exotoxin A to generate an anti-fAChR immunotoxin (scFv35-ETA).While scFv35-ETA had no damaging effect on fAChR-negative control cell lines, it killed human embryonic and alveolar RMS cell lines in vitro and delayed RMS development in a murine transplantation model. These results indicate that scFv35-ETA may be a valuable new therapeutic tool as well as a relevant step towards the development of a fully human immunotoxin directed against RMS. Moreover, as approximately 20\% of metastatic malignant melanomas (MMs) display rhabdoid features including the expression of fAChR, the immunotoxin we developed may also prove to be of significant use in the treatment of these more common and most often fatal neoplasms.}, subject = {Medizin}, language = {en} } @article{LausUlrichsMuellerRuchholtz1986, author = {Laus, R. and Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Molecular Specificity of Human Heterophile Antibodies (HHA) in Normal Human Serum (NHS) Reacting with Xenogeneic Cells.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72921}, year = {1986}, abstract = {No abstract available}, subject = {Immunobiologie}, language = {en} } @article{UlrichsKellerMuellerRuchholtz1985, author = {Ulrichs, Karin and Keller, R. and M{\"u}ller-Ruchholtz, W.}, title = {Serological demonstration and manipulation of passenger cells (PC) in pancreas islet grafts}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72944}, year = {1985}, abstract = {No abstract available}, subject = {Immunobiologie}, language = {en} } @article{KekowUlrichs1986, author = {Kekow, J. and Ulrichs, Karin}, title = {Determination of total immunoreactive rat insulin (IRI) in culture supernatants of rat islets by an enzyme linked immunosorbent assay (ELISA) as a routine method to assess the viability of rat islets prior to their use in islet transplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72989}, year = {1986}, abstract = {No abstract available}, subject = {Immunobiologie}, language = {en} } @article{KrzymanskiWaagaUlrichsetal.1991, author = {Krzymanski, Maciej and Waaga, Ana M. and Ulrichs, Karin and Deja, Aadam and Oko, Andrzej and Rommel, Thomas and M{\"u}ller-Ruchholtz, Wolfgang}, title = {The influence of MHC class II antigen blockade by perfusion with a monoclonal antibody on rat renal graft survival}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64431}, year = {1991}, abstract = {To decrease immunogenicity of the rat kidney, grafts were perfused with an anti-MHC class li monoclonal antibody (mAb ). How effectively this procedure blocked dass li-positive cells, which were mainly dendritic in appearance, was checked by immunostaining renal sections after perfusion and comparing them with in vitro stained sections. Optimum conditions were applied for graft pretreatment before transplantation. This procedure prolonged graft survival, though not satisfactorily from the biological point ofview (9.6 ± 0.8 versus 7.7 ± 0.5 days in the control group; P < 0.02). The dendritic cells were not killed but blocked. Several hours after transplantation, the mAb dissociated from these dass li-positive cells. It was also shown that donor cells migrate into the recipient's spieen early after transplantation. The number of these cells was smaller when the transplanted organ was perfused with the mAb. Further studies are suggested to deplete the graft of donor dendritic cells more adequately. They should also combine graft perfusion with antidass II mAb and recipient immunosuppression at reduced doses.}, subject = {Chirurgie}, language = {en} } @inproceedings{HeiserUlrichsMuellerRuchholtz1994, author = {Heiser, A. and Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Enzyme Kinetics of Commercial Collagenases and their Influence on Porcine Islet Isolation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45488}, year = {1994}, abstract = {No abstract available}, subject = {Heterotransplantation}, language = {en} } @inproceedings{HeiserUlrichsEcksteinetal.1992, author = {Heiser, A. and Ulrichs, Karin and Eckstein, V. and M{\"u}ller-Ruchholtz, W.}, title = {Xenogeneic Cellular Response of Human Lymphocytes Against Porcine Lymphocytes and Isolated Pancreatic Islets}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45479}, year = {1992}, abstract = {no abstract available}, language = {en} } @article{KekowUlrichsMuellerRuchholtzetal.1988, author = {Kekow, J{\"o}rn and Ulrichs, Karin and M{\"u}ller-Ruchholtz, Wolfgang and Gross, Wolfgang L.}, title = {Measurement of rat insulin. Enzyme-linked immunosorbent assay with increased sensitivity, high accuracy, and greater practicability than established radioimmunoassay}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45543}, year = {1988}, abstract = {Total immunoreactive insulin (IRI) is conventionally determined by radioimmunoassays. IR! measurement in rats can be made more sensitive, accurate, and practical, as demonstrated by a new modified enzyme-linked immunosorbent assay (ELlSA). It is characterized by indirect binding of an anti-insulin antibody by an antiglobulin antibody and uses the principle of competitive saturation. In this ELlSA, IRI can be determined in a wide range of concentrations, corresponding to the standards. The standard curve ranges from 100 to 0.049 ng/mllRI (1 ng/ml - 23.4 JLU/ml - 172 pM rat insulin). The statistical analysis shows between- and within-assay coefficients of variation of :515\%. Diabetes 37:321-26,1988}, subject = {Chirurgie}, language = {en} } @article{VonGaudeckerUlrichsMuellerRuchholtz1989, author = {Von Gaudecker, Brita and Ulrichs, Karin and M{\"u}ller-Ruchholtz, Wolfgang}, title = {Immunoelectron microscopic localization of MHC structures in isolated pancreatic rat islets}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45596}, year = {1989}, abstract = {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.}, subject = {Immunbiologie}, language = {en} } @misc{UlrichsMuellerRuchholtz1989, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Identification and Manipulation of Human Islet Alloimmunogenicity: Morphologic and Functional in Vitro Studies with Various Islet Preparations}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45584}, year = {1989}, abstract = {No abstract available}, subject = {Immunbiologie}, language = {en} } @article{UlrichsSchangKelleretal.1984, author = {Ulrichs, Karin and Schang, T. and Keller, R. and M{\"u}ller-Ruchholtz, W.}, title = {Reactivity of pancreas islet cells with antisera of known specificity}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45466}, year = {1984}, abstract = {No abstract available}, language = {en} } @article{UlrichsBosseWackeretal.1994, author = {Ulrichs, Karin and Bosse, M. and Wacker, HH and Heiser, A. and M{\"u}ller-Ruchholtz, W.}, title = {Histologic analysis of the porcine pancreas to improve islet yield and integrity after collagenase digestion}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45166}, year = {1994}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsEcksteinMuellerBuchholtz1994, author = {Ulrichs, Karin and Eckstein, V. and M{\"u}ller-Buchholtz, W.}, title = {Xenogeneic T-cell-mediated immune reactivity in the model of pig-to-humans: first findings with native stimulator cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44755}, year = {1994}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{WaagaUlrichsKrzymanskietal.1990, author = {Waaga, AM and Ulrichs, Karin and Krzymanski, M. and Treumer, J. and Hansmann, ML and Rommel, T. and M{\"u}ller-Ruchholz, W.}, title = {The immunosuppressive agent 15-deoxyspergualin induces tolerance and modulates MHC-antigen expression and interleukin-1 production in the early phase of rat allograft responses}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45253}, year = {1990}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsMuellerRuchholtz1988, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Expression of MHC Structures on Immunologically Reactive and Non Reactive Cells in Islets of Langerhans and Other Tissues}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45557}, year = {1988}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsMuellerRuchholtz1985, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Further Analyses of Pancreas Islet Immunogenicity, a Major Barrier to Successful Islet Transplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45563}, year = {1985}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsWinotoMorbachHeringetal.1990, author = {Ulrichs, Karin and Winoto-Morbach, S. and Hering, B. and M{\"u}ller-Ruchholtz, W.}, title = {A Useful Biotechnological Approach to Solve the Problem of Graft Purity in Human Pancreatic Islet Transplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45619}, year = {1990}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsMuellerRuchholtz1989, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Significant manipulative procedures to reduce immunogenicity of human islet allografts}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45155}, year = {1989}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{WinotoMorbachLeyhausenSchuenkeetal.1989, author = {Winoto-Morbach, S. and Leyhausen, G. and Sch{\"u}nke, M. and Ulrichs, Karin and M{\"u}ller-Buchholtz, W.}, title = {Magnetic microspheres (MMS) coupled to selective lectins: a new tool for large-scale extraction and purification of human pancreatic islets}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44789}, year = {1989}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{EcksteinMuellerBuchholtzUlrichs1994, author = {Eckstein, V. and M{\"u}ller-Buchholtz, W. and Ulrichs, Karin}, title = {Reaction patterns of natural xenophile antibodies in human sera with pancreatic islet cells and porcine lymphocytes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44742}, year = {1994}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsMuellerBuchholtz1985, author = {Ulrichs, Karin and M{\"u}ller-Buchholtz, W.}, title = {MHC class II antigen expression on the various cells of normal and activated isolated pancreatic islets}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44722}, year = {1985}, abstract = {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.}, language = {en} } @article{UlrichsDeltzThiedeetal.1982, author = {Ulrichs, Karin and Deltz, E. and Thiede, A. and M{\"u}ller-Ruchholtz, W.}, title = {Lymphoid tissue transplantation in rats leads to a GVHR, inducing a specific T-cell mediated autoreactivity against MHC-antigens}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45420}, year = {1982}, abstract = {No abstract available}, language = {en} } @article{UlrichsKuhlencordtMuellerRuchholtz1979, author = {Ulrichs, Karin and Kuhlencordt, KM and M{\"u}ller-Ruchholtz, W.}, title = {Plating inhibition assay (PIA): a new test for cell mediated cytotoxicity}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45443}, year = {1979}, abstract = {No abstract available}, language = {en} } @article{UlrichsMuellerRuchholtz1990, author = {Ulrichs, Karin and M{\"u}ller-Ruchholtz, W.}, title = {Mixed lymphocyte islet culture (MLIC) and its use in manipulation of human islet alloimmunogenicity}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45515}, year = {1990}, abstract = {No abstract available}, language = {en} } @article{WinotoMorbachUlrichsLeyhausenetal.1989, author = {Winoto-Morbach, Supandi and Ulrichs, Karin and Leyhausen, Gaby and M{\"u}ller-Ruchholtz, Wolfgang}, title = {New principle for large-scale preparation of purified human pancreas islets}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45600}, year = {1989}, abstract = {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}, subject = {Immunbiologie}, language = {en} } @article{HeiserUlrichsMuellerBuchholtz1994, author = {Heiser, Axel and Ulrichs, Karin and M{\"u}ller-Buchholtz, Wolfgang}, title = {Isolation of porcine pancreatic islets: low trypsin activity during the isolation procedure guarantees reproducible high islet yields}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44719}, year = {1994}, abstract = {During the past few years, interest in xenotransplantation of porcine islets of Langerhans for the future therapy of type I diabetes has Increased markedly. Therefore, we established a semiautomated digestion method for isolating islets from the porcine pancreas. However, although the isolation technique was standardized and collagenase of controlled quality was used, we were unable to attain high islet yields with a satisfactory degree of reproducibility. One hypothesis was that varying degrees of interference by donor pancreatic enzymes were responsible for this failure. The aim of this stUdy was to examine the kinetics of four types of enzymatic activity during the isolation procedure, as well as their effects on islet yield: collagenase, trypsin, neutral protease, and clostripaln. Our results indicate that while exogenous collagenase activity decreases slightly during the isolation procedure, the activity of the pancreas enzymes neutral protease and trypsin increases. In some cases, trypsin activity increases very strongly. A strong increase in trypsin activity correlates with poor islet yield, whereas low trypsin activity always correlates with high islet yield. Addition of the protease inhibitor Pefabloc to the isolation medium results in low trypsin activity and reproducible high islet yields.}, subject = {Langerhans-Inseln}, language = {en} } @article{WaagaKrzymanskiUlrichsetal.1993, author = {Waaga, AM and Krzymanski, M. and Ulrichs, Karin and Wierusz-Wysocka, Bogna and M{\"u}ller-Buchholtz, Wolfgang}, title = {Hematological effects of the new immunosuppressive drug 15-deoxyspergualin}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44701}, year = {1993}, abstract = {Since systematic hematological studies on blood and bone marrow changes after treatment with 15-Deoxyspergualin (DOS) are lacking, a quantitative assessment was performed fourteen or twenty eight days after intraperitoneal application of DOS to rats. Further observations done 7 and 14 days after discontinuation of DOS administration allowed analysis of banc marrow regeneration. DOS induced lymphocytopenia, granUlocytopenia and anemia with a decrease of bone marrow cellularity due to suppression of cell maturation. The effect was dose-dependent and bone marrow as well as blood changes were observed in animals treated with doses from 0.5 to 10.0 mg/kg DOS. Within 14 days after termination of the treatment, rapid recovery with normalization of all hematological parameters was observed. In the light of our data, these hematological side effects may not be a major disadvantage, if DOS is used in doses below 2.5 mg/kg, and for a course of therapy which is limited to 7 to 14 days.}, subject = {Chirurgie}, language = {en} } @article{DeltzMuellerHermelinkUlrichsetal.1981, author = {Deltz, E. and M{\"u}ller-Hermelink, HK and Ulrichs, Karin and Thiede, A. and M{\"u}ller-Ruchholtz, W.}, title = {Development of graft-versus-host reaction in various target organs after small intestine transplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45459}, year = {1981}, abstract = {The GVHRIL foHowing transplantation of small intestine are different from those found after bone marrow transplantation or spleen cell injections in that they show a remarka ble, significant prevalence of lesions within the intestinal mucosa. These findings are consistent with the observation that jntestinal lymphocytes newly formed in mesenteric lymph nodes predominantly home in on the intestine again.\& The degree of histologic alteration within different tissues indicates that the graft and the host may survive the lesions of the lymphatic tissues, whereas the severe intestinal lesions following GVHR may easily cause death of the recipient. With regard to clinical sman bowel transplantation two statements can be made: (l) GVHRIL play a significant role in small bowel trans~ plantation. (2) To minimize their biologic importance, a selective elimination of the graft's Jymph nodes by irradiation or surgical resection should be considered in view of the remarkable difference between GVHRIL in lymph nodes and in the graft's intestinal wall itself.}, subject = {Chirurgie}, language = {en} } @article{EcksteinUlrichsMeinckeetal.1992, author = {Eckstein, V. and Ulrichs, K. and Meincke, G. and M{\"u}ller-Ruchholtz, W.}, title = {Natural xenophile antibodies from sera of type I diabetic patients differ strongly in their reactivity against various porcine pancreatic cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45277}, year = {1992}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{UlrichsNoethlingKelleretal.1987, author = {Ulrichs, Karin and N{\"o}thling, R. and Keller, R. and Heusermann, U. and M{\"u}ller-Buchholtz, W.}, title = {Genetically determined variation of constitutive major histocompatibility complex class II antigen expression in various rat strains and cell types}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44769}, year = {1987}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{MuellerBuchholtzLeyhausenPetersonetal.1987, author = {M{\"u}ller-Buchholtz, W. and Leyhausen, G. and Peterson, P. and Schubert, G. and Ulrichs, Karin}, title = {A simple methodological principle for large scale extraction and purification of collagenase-digested islets}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44770}, year = {1987}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} } @article{BreitkreuzUlrichsEcksteinetal.1993, author = {Breitkreuz, A. and Ulrichs, Karin and Eckstein, V. and M{\"u}ller-Ruchholz, W.}, title = {Long-term suppression of natural and graft-induced xenophile antibodies by short-term antigen-cyclophosphamide treatment}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45262}, year = {1993}, abstract = {No abstract available}, subject = {Chirurgie}, language = {en} }