Refine
Has Fulltext
- yes (14)
Is part of the Bibliography
- yes (14)
Year of publication
Document Type
- Journal article (12)
- Report (2)
Keywords
- IGRT (2)
- inflammation (2)
- 5-fluorouracil (1)
- ALS (1)
- ARIA (1)
- Audiologie (1)
- CARAT (1)
- Caco2 cells (1)
- Chirurgie (1)
- Chlamydia (1)
Institute
- Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) (4)
- Theodor-Boveri-Institut für Biowissenschaften (4)
- Klinik und Poliklinik für Strahlentherapie (3)
- Institut für Psychologie (bis Sept. 2007) (2)
- Frauenklinik und Poliklinik (1)
- Institut für Anatomie und Zellbiologie (1)
- Institut für Klinische Epidemiologie und Biometrie (1)
- Institut für Molekulare Infektionsbiologie (1)
- Neurologische Klinik und Poliklinik (1)
EU-Project number / Contract (GA) number
- 101042738 (1)
Background: To introduce a novel method of patient positioning for high precision intracranial radiotherapy. Methods: An infrared(IR)-array, reproducibly attached to the patient via a vacuum-mouthpiece(vMP) and connected to the table via a 6 degree-of-freedom(DoF) mechanical arm serves as positioning and fixation system. After IR-based manual prepositioning to rough treatment position and fixation of the mechanical arm, a cone-beam CT(CBCT) is performed. A robotic 6 DoF treatment couch (HexaPOD™) then automatically corrects all remaining translations and rotations. This absolute position of infrared markers at the first fraction acts as reference for the following fractions where patients are manually prepositioned to within ± 2 mm and ± 2° of this IR reference position prior to final HexaPOD-based correction; consequently CBCT imaging is only required once at the first treatment fraction. The preclinical feasibility and attainable repositioning accuracy of this method was evaluated on a phantom and human volunteers as was the clinical efficacy on 7 pilot study patients. Results: Phantom and volunteer manual IR-based prepositioning to within ± 2 mm and ± 2° in 6DoF was possible within a mean(± SD) of 90 ± 31 and 56 ± 22 seconds respectively. Mean phantom translational and rotational precision after 6 DoF corrections by the HexaPOD was 0.2 ± 0.2 mm and 0.7 ± 0.8° respectively. For the actual patient collective, the mean 3D vector for inter-treatment repositioning accuracy (n = 102) was 1.6 ± 0.8 mm while intra-fraction movement (n = 110) was 0.6 ± 0.4 mm. Conclusions: This novel semi-automatic 6DoF IR-based system has been shown to compare favourably with existing non-invasive intracranial repeat fixation systems with respect to handling, reproducibility and, more importantly, intrafraction rigidity. Some advantages are full cranial positioning flexibility for single and fractionated IGRT treatments and possibly increased patient comfort.
Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed.
Evaluation of set up error detection by a transperineal ultrasound in comparison with a cone beam CT (CBCT) based system in external beam radiation therapy (EBRT) of prostate cancer.
Methods: Setup verification was performed with transperineal ultrasound (TPUS) and CBCT for 10 patients treated with EBRT for prostate cancer. In total, 150 ultrasound and CBCT scans were acquired in rapid succession and analyzed for setup errors. The deviation between setup errors of the two modalities was evaluated separately for each dimension.
Results: A moderate correlation in lateral, vertical and longitudinal direction was observed comparing the setup errors. Mean differences between TPUS and CBCT were (−2.7 ± 2.3) mm, (3.0 ± 2.4) mm and (3.2 ± 2.7) mm in lateral, vertical and longitudinal direction, respectively. The mean Euclidean difference between TPUS and CBCT was (6.0 ± 3.1) mm. Differences up to 19.2 mm were observed between the two imaging modalities. Discrepancies between TPUS and CBCT of at least 5 mm occurred in 58 % of monitored treatment sessions.
Conclusion: Setup differences between TPUS and CBCT are 6 mm on average. Although the correlation of the setup errors determined by the two different image modalities is rather week, the combination of setup verification by CBCT and intrafraction motion monitoring by TPUS imaging can use the benefits of both imaging modalities.
Clinical prognosis of metastasized colorectal carcinoma (CRC) is still not at desired levels and novel drugs are needed. Here, we focused on the multi-tyrosine kinase inhibitor E7080 (Lenvatinib) and assessed its therapeutic efficacy against human CRC cell lines in vitro and human CRC xenografts in vivo. The effect of E7080 on cell viability was examined on 10 humanCRCcell lines and humanendothelial cells (HUVEC). The inhibitory effect of E7080 on VEGF-induced angiogenesis was studied in an ex vivo mouse aortic ring angiogenesis assay. In addition, the efficacy of E7080 against xenografts derived fromCRC cell lines and CRC patient resection specimenswithmutated KRASwas investigated in vivo. Arelatively low cytotoxic effect of E7080 on CRC cell viabilitywas observed in vitro. Endothelial cells (HUVEC)weremore susceptible to the incubation with E7080. This is in line with the observation that E7080 demonstrated an anti-angiogenic effect in a three-dimensional ex vivo mouse aortic ring angiogenesis assay. E7080 effectively disrupted CRC cell-mediated VEGF-stimulated growth of HUVEC in vitro. Daily in vivo treatment with E7080 (5 mg/kg) significantly delayed the growth of KRAS mutated CRC xenografts with decreased density of tumor-associated vessel formations and without tumor regression. This observation is in line with results that E7080 did not significantly reduce the number of Ki67-positive cells in CRC xenografts. The results suggest antiangiogenic activity of E7080 at a dosage thatwas well tolerated by nudemice. E7080 may provide therapeutic benefits in the treatment of CRC with mutated KRAS.
Background: Pioglitazone, an oral anti-diabetic that stimulates the PPAR-gamma transcription factor, increased survival of mice with amyotrophic lateral sclerosis (ALS).
Methods/Principal Findings: We performed a phase II, double blind, multicentre, placebo controlled trial of pioglitazone in ALS patients under riluzole. 219 patients were randomly assigned to receive 45 mg/day of pioglitazone or placebo (one: one allocation ratio). The primary endpoint was survival. Secondary endpoints included incidence of non-invasive ventilation and tracheotomy, and slopes of ALS-FRS, slow vital capacity, and quality of life as assessed using EUROQoL EQ-5D. The study was conducted under a two-stage group sequential test, allowing to stop for futility or superiority after interim analysis. Shortly after interim analysis, 30 patients under pioglitazone and 24 patients under placebo had died. The trial was stopped for futility; the hazard ratio for primary endpoint was 1.21 (95% CI: 0.71-2.07, p = 0.48). Secondary endpoints were not modified by pioglitazone treatment. Pioglitazone was well tolerated.
Conclusion/Significance: Pioglitazone has no beneficial effects on the survival of ALS patients as add-on therapy to riluzole.
Deregulated expression of MYC is a driver of colorectal carcinogenesis, necessitating novel strategies to inhibit MYC function. The ubiquitin ligase HUWE1 (HECTH9, ARF-BP1, MULE) associates with both MYC and the MYC-associated protein MIZ1. We show here that HUWE1 is required for growth of colorectal cancer cells in culture and in orthotopic xenograft models. Using high-throughput screening, we identify small molecule inhibitors of HUWE1, which inhibit MYC-dependent transactivation in colorectal cancer cells, but not in stem and normal colon epithelial cells. Inhibition of HUWE1 stabilizes MIZ1. MIZ1 globally accumulates on MYC target genes and contributes to repression of MYC-activated target genes upon HUWE1 inhibition. Our data show that transcriptional activation by MYC in colon cancer cells requires the continuous degradation of MIZ1 and identify a novel principle that allows for inhibition of MYC function in tumor cells.
Certain pathogenic bacteria adopt an intracellular lifestyle and proliferate in eukaryotic host cells. The intracellular niche protects the bacteria from cellular and humoral components of the mammalian immune system, and at the same time, allows the bacteria to gain access to otherwise restricted nutrient sources. Yet, intracellular protection and access to nutrients comes with a price, i.e., the bacteria need to overcome cell-autonomous defense mechanisms, such as the bactericidal endocytic pathway. While a few bacteria rupture the early phagosome and escape into the host cytoplasm, most intracellular pathogens form a distinct, degradation-resistant and replication-permissive membranous compartment. Intracellular bacteria that form unique pathogen vacuoles include Legionella, Mycobacterium, Chlamydia, Simkania, and Salmonella species. In order to understand the formation of these pathogen niches on a global scale and in a comprehensive and quantitative manner, an inventory of compartment-associated host factors is required. To this end, the intact pathogen compartments need to be isolated, purified and biochemically characterized. Here, we review recent progress on the isolation and purification of pathogen-modified vacuoles and membranes, as well as their proteomic characterization by mass spectrometry and different validation approaches. These studies provide the basis for further investigations on the specific mechanisms of pathogen-driven compartment formation.
Loss of intestinal epithelial barrier function is a hallmark in digestive tract inflammation. The detailed mechanisms remain unclear due to the lack of suitable cell-based models in barrier research. Here we performed a detailed functional characterization of human intestinal organoid cultures under different conditions with the aim to suggest an optimized ex-vivo model to further analyse inflammation-induced intestinal epithelial barrier dysfunction. Differentiated Caco2 cells as a traditional model for intestinal epithelial barrier research displayed mature barrier functions which were reduced after challenge with cytomix (TNFα, IFN-γ, IL-1ß) to mimic inflammatory conditions. Human intestinal organoids grown in culture medium were highly proliferative, displayed high levels of LGR5 with overall low rates of intercellular adhesion and immature barrier function resembling conditions usually found in intestinal crypts. WNT-depletion resulted in the differentiation of intestinal organoids with reduced LGR5 levels and upregulation of markers representing the presence of all cell types present along the crypt-villus axis. This was paralleled by barrier maturation with junctional proteins regularly distributed at the cell borders. Application of cytomix in immature human intestinal organoid cultures resulted in reduced barrier function that was accompanied with cell fragmentation, cell death and overall loss of junctional proteins, demonstrating a high susceptibility of the organoid culture to inflammatory stimuli. In differentiated organoid cultures, cytomix induced a hierarchical sequence of changes beginning with loss of cell adhesion, redistribution of junctional proteins from the cell border, protein degradation which was accompanied by loss of epithelial barrier function. Cell viability was observed to decrease with time but was preserved when initial barrier changes were evident. In summary, differentiated intestinal organoid cultures represent an optimized human ex-vivo model which allows a comprehensive reflection to the situation observed in patients with intestinal inflammation. Our data suggest a hierarchical sequence of inflammation-induced intestinal barrier dysfunction starting with loss of intercellular adhesion, followed by redistribution and loss of junctional proteins resulting in reduced barrier function with consecutive epithelial death.