31 research outputs found
In vivo Reparaturkapazität von DNA Doppelstrangbrüchen männlicher Keimzellen und somatischer Zellen anhand reparatur-profizienter und -defizienter Mausstämme nach Bestrahlung
In vivo Reparaturkapazität von DNA Doppelstrangbrüchen männlicher Keimzellen und somatischer Zellen anhand reparatur-profizienter und -defizienter Mausstämme nach Bestrahlung
Successful treatment of a recurrent granulation polyp in the airways with high-dose-rate brachytherapy: a case report
Background Benign central airway tumors are very rare diseases. Their unspecific symptoms are responsible for late diagnosis. Endoscopic interventions with different techniques and tools are widely used for their treatment. However, in certain cases interventional endoscopy might be unsuccessful and therefore other methods such as high-dose-rate brachytherapy could be a therapeutic option. Case presentation A 76-year-old white German woman was referred to our clinic for an endoscopic treatment of a recurrent granulation polyp in her left main bronchus. She had dyspnea, coughing, and mucus retention. Three times resections via bronchoscopy were performed within less than a year. After each intervention the polyp regrew inside her left main bronchus causing a repeat of the initial symptoms. She presented to our clinic less than 1Â month since the last intervention. Twice we performed a rigid bronchoscopy in total anesthesia where we resected the granulation polyp with a snare wire loop and did an argon plasma coagulation of its base. Due to the recurrent growing of the granuloma, we performed a high-dose-rate brachytherapy in conscious sedation after another interventional bronchoscopy with a resection of the polyp and argon plasma coagulation of the base. Three months after brachytherapy our patient came to our clinic for a follow-up with none of the initial symptoms. Only a small remnant of the polyp without a significant occlusion of her bronchus was visualized by bronchoscopy. Furthermore, 6Â months after brachytherapy she was not presenting any of the initial symptoms. Conclusions This case report shows that high-dose-rate brachytherapy is a therapeutic option for the treatment of benign airway stenosis when other interventional treatments are not or are less than successful. However, further investigations are needed to prove the effectiveness and reliability of the method
Prospective phase-II-study evaluating postoperative radiotherapy of cervical and endometrial cancer patients using protons – the APROVE-trial
Background: The prognosis for patients with cervical or endometrial cancer has improved over the last decades. Thus, reducing therapy-related toxicity and impact on quality of life have become more and more important. With the development of new radiotherapy techniques like IMRT (Intensity-modulated radiotherapy) the incidence of acute and chronic toxicities has already been reduced. Nevertheless, rates of complications requiring medical treatment range from 0.7–8% according to literature. 7.7% of patients develop severe complications after 5 years with an increasing risk for complications of 0.3%/year. Particularly, the volume of the small and large bowel receiving low doses (15 Gy) has been shown to be a predictive factor for the development of higher bowel toxicity. With the introduction of proton therapy into clinical practice, there are new opportunities for optimization of organ at risk-sparing thus possibly reducing toxicity.
Methods/design: The APROVE study is a prospective single-center one-arm phase-II-study. Patients with cervical or endometrial cancer after surgical resection who have an indication for postoperative pelvic radiotherapy will be treated with proton therapy instead of the commonly used photon radiation. A total of 25 patients will be included in this trial. Patients will receive a dose of 45–50.4 GyE in 1.8 GyE fractions 5–6 times per week using active raster-scanning pencil beam proton radiation. Platinum-based chemotherapy can be administered if indicated. For treatment planning, rectum, sigma, large and small bowel, bladder and femoral heads are defined as organs at risk. The CTV is defined according to the RTOG consensus guidelines.
Discussion: The primary endpoint of the study is the evaluation of safety and treatment tolerability of pelvic radiation using protons defined as the lack of any CTC AE Grade 3 or 4 toxicity. Secondary endpoints are clinical symptoms and toxicity, quality of life and progression-free survival. The aim is to explore the potential of proton therapy as a new method for adjuvant pelvic radiotherapy to decrease the dose to the bowel, rectum and bladder thus reducing acute and chronic toxicity and improving quality of life.
Trial registration: Registered at https://clinicaltrials.gov , ClinicalTrials.gov Identifier: NCT03184350 , registered 09 June 2017, enrolment of the first participant 19 June 2017
Factors influencing participation in a randomized controlled resistance exercise intervention study in breast cancer patients during radiotherapy
Background: Over the past years knowledge about benefits of physical activity after cancer is evolving from randomized exercise intervention trials. However, it has been argued that results may be biased by selective participation. Therefore, we investigated factors influencing participation in a randomized exercise intervention trial for breast cancer patients. Methods: Non-metastatic breast cancer patients were systematically screened for a randomized exercise intervention trial on cancer-related fatigue. Participants and nonparticipants were compared concerning sociodemographic characteristics (age, marital status, living status, travel time to the training facility), clinical data (body-mass-index, tumor stage, tumor size and lymph node status, comorbidities, chemotherapy), fatigue, and physical activity. Reasons for participation or declination were recorded. Results 117 patients (52 participants, 65 nonparticipants) were evaluable for analysis. Multiple regression analyses revealed significantly higher odds to decline participation among patients with longer travel time (p = 0.0012), living alone (p = 0.039), with more comorbidities (0.031), previous chemotherapy (p = 0.0066), of age ≥ 70 years (p = 0.025), or being free of fatigue (p = 0.0007). No associations were found with BMI or physical activity. By far the most frequently reported reason for declination of participation was too long commuting time to the training facility. Conclusions: Willingness of breast cancer patients to participate in a randomized exercise intervention study differed by sociodemographic factors and health status. Neither current physical activity level nor BMI appeared to be selective for participation. Reduction of personal inconveniences and time effort, e.g. by decentralized training facilities or flexible training schedules, seem most promising for enhancing participation in exercise intervention trials. Trial registration: Registered at ClinicalTrials.gov: NCT01468766 (October 2011)
Dissolved Organic Nitrogen: An Overlooked Pathway of Nitrogen Loss from Agricultural Systems?
Highly nonlinear light-matter interaction using cavity-enhanced frequency combs
Cavity-enhanced frequency combs are a powerful tool for studying highly nonlinear light-matter interactions, such as multiphoton ionization (MPI) and high-harmonic generation (HHG), with promising prospects for precision spectroscopy beyond the optical spectral range. In this work, a metrology-capable extreme ultraviolet (XUV) frequency comb is produced by transferring a near-infrared comb at 1039 nm to the XUV, using intra-cavity HHG. Intensities of ∼1E14 W/cm² are reached in the cavity focus, producing XUV radiation up to 42 eV (30 nm) and tens of microwatts of outcoupled power. A high-pressure closed-loop noble gas recycling and compression system enables long-term measurements. Additionally, a novel polarization-insensitive cavity with an integrated velocity-map imaging spectrometer was developed. 3D photoelectron angular distributions from xenon MPI are tomographically reconstructed, revealing resonant Rydberg states during ionization. Furthermore, polarization-shaped pulse pairs with a variable time delay are provided for pump-probe experiments. Intense femtosecond standing waves, produced by counter-propagating pulses colliding at the focus, are probed at the nanometer scale using photoemission from a nano-tip. The coherence of the frequency comb is imprinted on the photoelectrons, allowing future precision measurements with coherent matter waves. This work broadens the scope of cavity-enhanced frequency combs and enables strong-field studies at 100 MHz repetition rate
"frauen fremder ordnung". Fünf Thesen zur strukturellen Misogynie des George-Kreises
Andres J. "frauen fremder ordnung". Fünf Thesen zur strukturellen Misogynie des George-Kreises. In: Oelmann U, Raulff U, eds. Frauen um Stefan George. Castrum peregrini ; N.F. Vol 3. Göttingen: Wallstein-Verl.; 2010: 37-57
Perls, Richard
Andres J. Perls, Richard. In: Aurnhammer A, Braungart W, Breuer S, Oelmann U, eds. Stefan George und sein Kreis. Ein Handbuch. Bd. 3. Berlin / Boston: de Gruyter; 2012: 1576-1577