Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ct Germer is active.

Publication


Featured researches published by Ct Germer.


BMC Cancer | 2010

Evaluation of Best Supportive Care and Systemic Chemotherapy as Treatment Stratified according to the retrospective Peritoneal Surface Disease Severity Score (PSDSS) for Peritoneal Carcinomatosis of Colorectal Origin

Joerg Pelz; Terence C. Chua; Jesus Esquivel; Alexander Stojadinovic; Joerg Doerfer; David L. Morris; Uwe Maeder; Ct Germer; Alexander Kerscher

BackgroundWe evaluate the long-term survival of patients with peritoneal carcinomatosis (PC) treated with systemic chemotherapy regimens, and the impact of the of the retrospective peritoneal disease severity score (PSDSS) on outcomes.MethodsOne hundred sixty-seven consecutive patients treated with PC from colorectal cancer between years 1987-2006 were identified from a prospective institutional database. These patients either received no chemotherapy, 5-FU/Leucovorin or Oxaliplatin/Irinotecan-based chemotherapy. Stratification was made according to the retrospective PSDSS that classifies PC patients based on clinically relevant factors. Survival analysis was performed using the Kaplan-Meier method and comparison with the log-rank test.ResultsMedian survival was 5 months (95% CI, 3-7 months) for patients who had no chemotherapy, 11 months (95% CI, 6-9 months) for patients treated with 5 FU/LV, and 12 months (95% CI, 4-20 months) for patients treated with Oxaliplatin/Irinotecan-based chemotherapy. Survival differed between patients treated with chemotherapy compared to those patients who did not receive chemotherapy (p = 0.026). PSDSS staging was identified as an independent predictor for survival on multivariate analysis [RR 2.8 (95%CI 1.5-5.4); p < 0.001].ConclusionA trend towards improved outcomes is demonstrated from treatment of patients with PC from colorectal cancer using modern systemic chemotherapy. The PSDSS appears to be a useful tool in patient selection and prognostication in PC of colorectal origin.


Journal of Experimental & Clinical Cancer Research | 2011

LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?

Burkhard H. A. von Rahden; Stefan Kircher; Maria Lazariotou; Christoph Reiber; Luisa Stuermer; Christoph Otto; Ct Germer; Martin Grimm

BackgroundInvestigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barretts Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis.Materials and methodsExpression 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.ResultsLgR5was 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 mRNA-level, 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.ConclusionThe 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.


Cellular Oncology | 2010

Tumor necrosis factor-α is associated with positive lymph node status in patients with recurrence of colorectal cancer-indications for anti-TNF-α agents in cancer treatment.

Martin Grimm; Maria Lazariotou; Stefan Kircher; Andreas Höfelmayr; Ct Germer; B. H. A. von Rahden; Ana Maria Waaga-Gasser; Martin Gasser

Introduction: The progressive growth of malignancies is accompanied by a decline in the immune response through mechanisms which are poorly understood. Apoptosis and induction of inflammation by tumor released cytokines as tumor escape mechanisms have been proposed to play an important role in colorectal carcinogenesis. Methods: Expression of Tumor necrosis factor-alpha (TNF-α) was analyzed in colorectal cancer specimen and the cancer cell line HT-29 by immunohistochemistry and RT-PCR. TNF-α expression on protein and mRNA level were correlated with clinical characteristics and impact on survival. TNFR-1 was co-labelled with TNF-α and CD8+ cytotoxic T cells in immunofluorescence double staining experiments. Results: 94% (n=98/104) of the patients with CRC expressed TNF-α. High TNF-α expression was significantly associated with positive lymph node stage and recurrence of the tumor. Multivariate analysis revealed high TNF-α expression as an independent prognostic factor. Immunohistochemistry was correlated with RT-PCR results (τ=0.794). Immunofluorescence double staining experiments revealed increased TNFR-1 expression by CD8+ cells. Conclusion: TNF-α expression by tumor cells may be an efficient immunological escape mechanism by inflammation-enhanced metastases and probably by induction of apoptosis in tumor-infiltrating CD8+ immune cells resulting in a down regulation of the tumoral immune response. Our data support the role of tumor-derived TNF-α expression as an important promoter of tumoral immune escape mechanisms and malignant progression, and suggest that analysis on either protein (immunohistochemistry) or RNA level (RT-PCR) can be used effectively in this respect. Targeting TNF-α may be a promising option, especially in cases with high TNF-α expression and positive lymph node metastases.


BMC Cancer | 2010

Evaluation of immunological escape mechanisms in a mouse model of colorectal liver metastases

Martin Grimm; Martin Gasser; Marco Bueter; Johanna Strehl; Johann Wang; Ekaterina Nichiporuk; Detlef Meyer; Ct Germer; Ana Maria Waaga-Gasser; Andreas Thalheimer

BackgroundThe local and systemic activation and regulation of the immune system by malignant cells during carcinogenesis is highly complex with involvement of the innate and acquired immune system. Despite the fact that malignant cells do have antigenic properties their immunogenic effects are minor suggesting tumor induced mechanisms to circumvent cancer immunosurveillance. The aim of this study is the analysis of tumor immune escape mechanisms in a colorectal liver metastases mouse model at different points in time during tumor growth.MethodsCT26.WT murine colon carcinoma cells were injected intraportally in Balb/c mice after median laparotomy using a standardized injection technique. Metastatic tumor growth in the liver was examined by standard histological procedures at defined points in time during metastatic growth. Liver tissue with metastases was additionally analyzed for cytokines, T cell markers and Fas/Fas-L expression using immunohistochemistry, immunofluorescence and RT-PCR. Comparisons were performed by analysis of variance or paired and unpaired t test when appropriate.ResultsIntraportal injection of colon carcinoma cells resulted in a gradual and time dependent metastatic growth. T cells of regulatory phenotype (CD4+CD25+Foxp3+) which might play a role in protumoral immune response were found to infiltrate peritumoral tissue increasingly during carcinogenesis. Expression of cytokines IL-10, TGF-β and TNF-α were increased during tumor growth whereas IFN-γ showed a decrease of the expression from day 10 on following an initial increase. Moreover, liver metastases of murine colon carcinoma show an up-regulation of FAS-L on tumor cell surface with a decreased expression of FAS from day 10 on. CD8+ T cells express FAS and show an increased rate of apoptosis at perimetastatic location.ConclusionsThis study describes cellular and macromolecular changes contributing to immunological escape mechanisms during metastatic growth in a colorectal liver metastases mouse model simulating the situation in human cancer.


Journal of Translational Medicine | 2010

MMP-1 is a (pre-)invasive factor in Barrett-associated esophageal adenocarcinomas and is associated with positive lymph node status

Martin Grimm; Maria Lazariotou; Stefan Kircher; Luisa Stuermer; Christoph Reiber; Andreas Höfelmayr; Stefan Gattenlöhner; Christoph Otto; Ct Germer; Burkhard H. A. von Rahden

BackgroundEsophageal adenocarcinomas (EACs) arise due to gastroesophageal reflux, with Barretts esophagus (BE) regarded as precancerous lesion. Matrix metalloproteinases (MMPs) might play a role during the multistep carcinogenetic process.MethodsExpression 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.ResultsOn 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).ConclusionsOur 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.


Chirurg | 2011

Therapie der Netz(-Implantat)-Infektion

U.A. Dietz; L. Spor; Ct Germer

Infections of an implanted hernia mesh are a major challenge. The incidence of mesh infections after incisional hernia repair is about 1% for endoscopic techniques and can be more than 15% in open techniques. Intraoperative mesh contamination is considered to be the primary cause. All woven or knitted hernia meshes have recesses where bacteria may adhere and establish colonies. The bacterial spectrum for mesh infection includes skin pathogens, such as Staphylococcus aureus (including MRSA), Streptococcus spp., as well as E. coli, Enterococcus and Mycobacteria. The therapy approach needs to be tailored to the morphological findings and the treatment for uncomplicated phlegmon is broad spectrum antibiotic therapy. If there is encapsulated fluid accumulation, CT-controlled drainage and daily infusion of antiseptics via the drain is a good option. For dermal necrosis, mesh fistula, exposed mesh or enterocutaneous fistula, a precise CT evaluation is necessary to tailor the operation. Vacuum systems are gaining increased acceptance in conditioning the local findings. For most patients the therapeutic concept will be based on individual decisions. If parts of a formerly infected mesh remain in the patient, a lifelong follow-up is necessary.ZusammenfassungDie Netzinfektion ist für den Patienten und den behandelnden Operateur eine große Belastung. Die Inzidenzrate bei Narbenhernien liegt zwischen 1% bei laparoskopischen Eingriffen bis über 15% bei offenen Verfahren. Als primäre Ursache gilt die intraoperative Kontamination der Netze. Alle gewebten oder gestrickten Netze haben Nischen, in denen sich Bakterien ansiedeln können. Das Keimspektrum der Netzinfektionen umfasst Hautkeime wie Staphylococcus aureus (inkl. MRSA) und Streptococcus spp, aber auch E. coli, Enterokokkus und Mycobacteriae. Ausgang für die Therapie ist die Morphologie des Befundes. Bei unkomplizierter Phlegmone ist die kalkulierte Antibiotikatherapie das Verfahren der Wahl. Bei infiziertem Verhalt ist die CT-gesteuerte Punktion mit Kathetereinlage und täglicher Spülung eine Option. Bei Hautnekrose, prothetokutaner Fistel, freiliegendem Netz oder enterokutaner Fistel muss der Befund nach bildgebender Diagnostik in Narkose exploriert werden. Zunehmende Bedeutung gewinnt dabei die Vakuumkonditionierung. Bei den meisten Patienten wird das Therapiekonzept eine Individualentscheidung sein. Wenn der Patient ein Teil des ehemals infizierten Netzes behält, ist ein längeres Follow-up nötig.AbstractInfections of an implanted hernia mesh are a major challenge. The incidence of mesh infections after incisional hernia repair is about 1% for endoscopic techniques and can be more than 15% in open techniques. Intraoperative mesh contamination is considered to be the primary cause. All woven or knitted hernia meshes have recesses where bacteria may adhere and establish colonies. The bacterial spectrum for mesh infection includes skin pathogens, such as Staphylococcus aureus (including MRSA), Streptococcus spp., as well as E. coli, Enterococcus and Mycobacteria. The therapy approach needs to be tailored to the morphological findings and the treatment for uncomplicated phlegmon is broad spectrum antibiotic therapy. If there is encapsulated fluid accumulation, CT-controlled drainage and daily infusion of antiseptics via the drain is a good option. For dermal necrosis, mesh fistula, exposed mesh or enterocutaneous fistula, a precise CT evaluation is necessary to tailor the operation. Vacuum systems are gaining increased acceptance in conditioning the local findings. For most patients the therapeutic concept will be based on individual decisions. If parts of a formerly infected mesh remain in the patient, a lifelong follow-up is necessary.


BMC Cancer | 2009

The intraportal injection model: A practical animal model for hepatic metastases and tumor cell dissemination in human colon cancer

Andreas Thalheimer; Christoph Otto; Marco Bueter; Bertram Illert; Stefan Gattenlöhner; Martin Gasser; Detlef Meyer; Martin Fein; Ct Germer; Ana Maria Waaga-Gasser

BackgroundThe development of new therapeutic strategies for treatment of metastasized colorectal carcinoma requires biologically relevant and adequate animal models that generate both reproducible metastasis and the dissemination of tumor cells in the form of so-called minimal residual disease (MRD), an expression of the systemic character of neoplastic disease.MethodsWe injected immunoincompetent nude mice intraportally with different numbers (1 × 105, 1 × 106 and 5 × 106 cells) of the human colon carcinoma cell lines HT-29 and SW-620 and investigated by histological studies and CK-20 RT-PCR the occurrence of hematogenous metastases and the dissemination of human tumor cells in bone marrow.ResultsOnly the injection of 1 × 106 cells of each colon carcinoma cell line produced acceptable perioperative mortality with reproducible induction of hepatic metastases in up to 89% of all animals. The injection of 1 × 106 cells also generated tumor cell dissemination in the bone marrow in up to 63% of animals with hepatic metastases.ConclusionThe present intraportal injection model in immunoincompetent nude mice represents a biologically relevant and adequate animal model for the induction of both reproducible hepatic metastasis and tumor cell dissemination in the bone marrow as a sign of MRD.


Journal of Surgical Research | 2013

Noninvasive visualization of tumor growth in a human colorectal liver metastases xenograft model using bioluminescence in vivo imaging.

Andreas Thalheimer; Doreen Korb; Lars Bönicke; Armin Wiegering; Bettina Mühling; Manuela Schneider; Silvia Koch; Simone S. Riedel; Ct Germer; Andreas Beilhack; Stephanie Brändlein; Christoph Otto

BACKGROUND Bioluminescence imaging (BLI) is an ideal tool for noninvasive, quantitative monitoring of tumor progression/regression in animal models. The effectiveness of different treatment strategies is displayed by an altered intensity of bioluminescence, demonstrating a change of the tumor burden. The aim of this study was to establish a reliable, reproducible colorectal hepatic metastases cancer animal model. METHODS Cells of the human colon carcinoma cell line HCT-116 Luc(pos) expressing the firefly luciferase enzyme gene were used. HCT-116 Luc(pos) cells (2.5 × 10(6)) were injected through the portal vein into the liver of immunoincompetent nude mice. BLI was used to analyze intrahepatic tumor burden and growth kinetic. RESULTS HCT-116 Luc(pos) cells demonstrated a progressive and reproducible growth in the liver after intraportal injection. Four days after injection, the animals were analyzed for tumor growth by BLI, and mice without or too low bioluminescence signals were excluded (between 10% and 20% animals). HCT-116 Luc(pos) intrahepatic tumors responded successfully to different dosages (5 and 10 mg/kg) of 5-fluorouracil. CONCLUSIONS BLI is an important tool with many potential advantages for investigators. The measurement of intrahepatic tumor growth by imaging luciferase activity noninvasively provides valuable information on tumor burden and effectiveness of therapy. Thus, the presented intrahepatic metastases model based on the growth of HCT-116 Luc(pos) cells is suitable for in vivo testing of different cancer therapy strategies.


Cancer Biomarkers | 2011

Glucocorticoid-induced TNFR family-related receptor (GITR)-expression in tumor infiltrating leucocytes (TILs) is associated with the pathogenesis of esophageal adenocarcinomas with and without Barrett's mucosa.

Burkhard H.A. von Rahden; Stefan Kircher; M. Kafka; Luisa Stuermer; Christoph Reiber; Stefan Gattenlöhner; Ct Germer; Martin Grimm

BACKGROUND Esophageal adenocarcinomas (EACs) arise due to gastroesophageal reflux, with Barretts esophagus (BE) regarded as precancerous lesion. Glucocorticoid-induced TNFR family-related Receptor (GITR)-mediated inflammation of tumor infiltrating leucocytes (TILs) in the tumor microenvironment might play a role during the multistep carcinogenetic process as either tumor promoting factor according to an inflammatory microenvironment or as a feature of anti-tumor activity. METHODS Immunohistochemical analysis of GITR expression was analyzed in esophageal cancer (n=70: 41 EAC with BE, 19 EAC without BE, and n=10 esophageal squamous-cell carcinomas, ESCC), the adenocarcinoma cell line OE-33, and peripheral blood leucocytes (PBLs) of EAC patients, furthermore in biopsies of BE without intraepithelial neoplasia (IN) (n=18). Results were correlated with clinicopathological parameters and five-year survival rates. Immunohistochemical GITR expression results were confirmed on mRNA level (RT-PCR). RESULTS Quantification showed a significant increase of 25% GITR positive TILs in EAC with BE (p< 0.05) compared to 13% in adjacent BE, 24% in EAC without BE, 14% in ESCC, and 1% in BE without IN. High GITR levels were not significantly associated with clinicopathologic features which may predict worse clinical outcome and had no impact on survival (p= 0.7878). Increased GITR expression of peripheral blood leucocytes (PBLs) in EAC patients was shown on protein level (32%) and confirmed by RT-PCR (3.7-fold difference compared to normal tissue). CONCLUSIONS This study provides for the first time evidence that GITR expression of TILs is associated in the pathogenesis of Barretts esophagus. Our findings suggest that GITR-expression of TILs is associated with cancer progression. Its role as either tumor promoting factor %according to an in the inflammatory microenvironment or as a feature of anti-tumor activity and promising target for molecular therapies needs to be substantiated in further investigations.


Free Radical Biology and Medicine | 2016

Impact of weight loss induced by gastric bypass or caloric restriction on oxidative stress and genomic damage in obese Zucker rats

Ezgi Eyluel Bankoglu; Florian Seyfried; Laura Rotzinger; Arno Nordbeck; Caroline Corteville; Christian Jurowich; Ct Germer; Christoph Otto; Helga Stopper

BACKGROUND Evidence on bariatric surgery induced weight loss and its possible impact on cancer risk is limited, but also controversial. We used obese Zucker(fa/fa) and lean Zucker(fa/+) to investigate the association between obesity, oxidative stress and genomic damage after weight loss induced either by Roux-en-Y gastric bypass surgery (RYGB) or caloric restriction. METHODS Male Zucker(fa/fa) rats underwent RYGB (n=15) or sham surgery (n=17). Five shams were food restricted and body weight matched (BWM) to RYGB. Twelve Zucker(fa/+) rats served as lean controls. Body weight and food intake were measured daily. An oral glucose tolerance test was performed on day 27. DHE staining and western blots of HSP70 and HO-1 were used to evaluate oxidative stress and anti-3-nitrotyrosine antibody staining for nitrative stress detection in colon and kidney. Lipid peroxidation products in urine were quantified by TBARS assay. LC/MS/MS was applied to measure urinary excretion of 8-oxoGua (oxidized DNA derived base), 8-oxodG (oxidized DNA derived nucleoside) and 8-oxoGuo (oxidized RNA derived nucleoside). DNA double strand breaks (DSBs) and cell proliferation (PCNA) were detected by immunohistochemistry. RESULTS Sham-operated rats showed impaired glucose tolerance, elevated plasma insulin levels as well as elevated oxidative stress and nitrative stress markers, which were less severe after weight loss by RYGB or caloric restriction. Cell proliferation showed similar trends but no significant alteration. DNA DSBs were more frequent in sham-operated compared to all other groups. DNA damage in Zucker(fa/fa) rats positively correlated with basal plasma insulin values (Spearmans correlation coefficient for colon, 0.634 and for kidney, 0.525). CONCLUSIONS RYGB and caloric restriction were sufficient to significantly reduce elevated oxidative/nitrative stress and genomic damage in obese Zucker(fa/fa) rats. Further investigations are needed to elucidate the underlying mechanism of these genome protective effects.

Collaboration


Dive into the Ct Germer's collaboration.

Top Co-Authors

Avatar

J. Filser

University of Würzburg

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Martin Grimm

University of Würzburg

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Mia Kim

University of Würzburg

View shared research outputs
Researchain Logo
Decentralizing Knowledge