[Late toxicity following primary conservative treatment : Dysphagia and xerostomia]. / Spättoxizität nach primär konservativer Therapie : Dysphagie und Xerostomie.

Dysphagia and xerostomia are still among the most important acute and late side effects of radiotherapy. Technical developments over the past two decades have led to improved diagnostics and recognition as well as understanding of the causes of these side effects. Based on these findings and advances in both treatment planning and irradiation techniques, the incidence and severity of treatment-associated radiogenic late sequelae could be clearly reduced by the use of intensity-modulated radiotherapy (IMRT), which could contribute to marked long-term improvements in the quality of life in patients with head and neck cancer. Highly conformal techniques, such as proton therapy have the potential to further reduce treatment-associated side effects in head and neck oncology and are currently being prospectively tested within clinical trial protocols at several centers.

Cost-effectiveness analysis (CEA) of IMRT plus C12 boost vs IMRT only in adenoid cystic carcinoma (ACC) of the head and neck.

BACKGROUND: Particle therapy provides steep dose gradients to facilitate dose escalation in challenging anatomical sites which has been shown not only to improve local control but also overall survival in patients with ACC. Cost-effectiveness of intensity-modulated radiotherapy (IMRT) plus carbon ion (C12) boost vs IMRT alone was performed in order to objectivise and substantiate more widespread use of this technology in ACC. METHODS: Patients with pathologically confirmed ACC received a combination regimen of IMRT plus C12 boost. Patients presenting outside C12 treatment slots received IMRT only. Clinical results were published; economic analysis on patient-level data was carried out from a healthcare purchaser's perspective based on costs of healthcare utilization. Cost histories were generated from resource use recorded in individual patient charts and adjusted for censoring using the Lin I method. Cost-effectiveness was measured as incremental cost-effectiveness ratio (ICER). Sensitivity analysis was performed regarding potentially differing management of recurrent disease. RESULTS: The experimental treatment increased overall costs by € 18,076 (€13,416 - €22,922) at a mean survival benefit of 0.86 years. Despite improved local control, following costs were also increased in the experimental treatment. The ICER was estimated to 26,863 €/LY. After accounting for different management of recurrent disease in the two cohorts, the ICER was calculated to 20,638 €/LY. CONCLUSION: The combined treatment (IMRT+C12 boost) substantially increased initial and overall treatment cost. In view of limited treatment options in ACC, costs may be acceptable though. Investigations into quality of life measures may support further decisions in the future.

Phase II study of induction chemotherapy with docetaxel, cisplatin, 5-fluorouracil followed by radioimmunotherapy with cetuximab and intensity-modulated radiotherapy in combination with a carbon ion boost for locally advanced tumors of the oro-, hypopharynx and larynx.

PURPOSE: This phase II trial was designed to evaluate efficacy and safety of a highly intensified therapy in locally advanced squamous cell carcinoma of the oro-, hypopharynx and larynx. METHODS: In this prospective, mono-centric, open-label, non-randomized phase II trial the single treatment arm consisted of a combined induction chemotherapy with docetaxel, cisplatin, 5-fluorouracil, followed by bioradiation with the monoclonal antibody cetuximab, carbon ion boost (24Gy(RBE) in 8 fractions) and IMRT (50 Gy in 25 fractions). The trial was closed early due to slow accrual. RESULTS: Eight patients (median age 52.5 years) were enrolled into the trial. The median follow-up was 13 months and the 12-months locoregional tumor control, progression-free survival and overall survival rates were 100.0% each. Complete remission was achieved in 7 patients. The most commonly late radiation adverse event was xerostomia (85.7% at 12 months). Five serious adverse events with recovery were documented in 4 patients: mucositis grade 3 (n = 2), decreased lymphocyte count grade 4, febrile neutropenia grade 4 and hypersensitivity grade 3 to cetuximab (n = 1 each). Most symptom scales had their worst value at the last treatment day and recovered until the 4th follow-up visit. CONCLUSION: The study treatment was tolerable and promising. Reduced quality of life recovered for most aspects until the last follow-up visit.

Carbon ion therapy (C12) for high-grade malignant salivary gland tumors (MSGTs) of the head and neck: do non-ACCs profit from dose escalation?

PURPOSE: To evaluate the use of high-dose radiotherapy using carbon ions (C12) on non-adenoid cystic malignant salivary gland tumors (MSGT). PATIENTS AND METHODS: Between 2009 and 2013, patients with biopsy-proven non-ACC MSGT histologies of the head and neck received a combined regimen of IMRT plus C12 boost. Treatment toxicity (CTC v3), response (RECIST 1.1), control and survival rates were retrospectively analyzed. RESULTS: 40 patients with pathologically confirmed non-ACC MSGT (T4: 45 %; N+: 40 %; gross residual: 58 %; mucoepidermoid carcinoma (MEC): 45 %; adenocarcinoma: 20 %) were treated with a median of 74 GyE (80 Gy BED). Chemoradiation was given in 5 patients with MEC. Grade III acute toxicity was observed in up to 15 % (mucositis, dermatitis, dysphagia), no higher-grade late toxicity occurred to date. At a follow-up of 25.5 months, LC, and PFS at 2 and 3 years are 81.5 % (LC) and 66.8 % (PFS), OS at 2 and 3 years is 83.6 % and 72.8 %. Most frequent site of disease progression was distant metastasis. Histologic subtype correlated with LC and PFS. Resection status (gross vs microscopic disease) had no significant effect on LC, PFS, or OS. CONCLUSION: The treatment is well tolerated, no higher grade late effects were observed. Considering the negative pre-selection, LC, PFS and OS are promising. While histology and site of origin significantly influenced control and survival rates, resection status did not, potentially due to the effect of dose escalation.

One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein.

Flame spray pyrolysis (FSP) of Bi(III)- and Mo(VI)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides α-Bi2Mo3O12 and γ-Bi2MoO6, FSP gave direct access to the metastable ß-Bi2Mo2O9 phase with high surface area (19 m(2) g(-1)). This phase is normally only obtained at high calcination temperatures (>560 °C) resulting in lower surface areas. The ß-phase was stable up to 400 °C and showed superior catalytic performance compared to α- and γ-phases in selective oxidation of propylene to acrolein at temperatures relevant for industrial applications (360 °C).

Experimental methods and modeling techniques for description of cell population heterogeneity.

With the continuous development, in the last decades, of analytical techniques providing complex information at single cell level, the study of cell heterogeneity has been the focus of several research projects within analytical biotechnology. Nonetheless, the complex interplay between environmental changes and cellular responses is yet not fully understood, and the integration of this new knowledge into the strategies for design, operation and control of bioprocesses is far from being an established reality. Indeed, the impact of cell heterogeneity on productivity of large scale cultivations is acknowledged but seldom accounted for. In order to include population heterogeneity mechanisms in the development of novel bioprocess control strategies, a reliable mathematical description of such phenomena has to be developed. With this review, we search to summarize the potential of currently available methods for monitoring cell population heterogeneity as well as model frameworks suitable for describing dynamic heterogeneous cell populations. We will furthermore underline the highly important coordination between experimental and modeling efforts necessary to attain a reliable quantitative description of cell heterogeneity, which is a necessity if such models are to contribute to the development of improved control of bioprocesses.

Review of clinical experience with ion beam radiotherapy.

The article describes both the early development of oncology as a core discipline at the University of Heidelberg Hospital and the first steps towards ion beam treatment, from the pilot project carried out in co-operation with the Gesellschaft für Schwerionenforschung Darmstadt to the initial start-up of clinical service at the Heidelberg Heavy Ion Centre (HIT). We present an overview, based on data published in the literature, of the available clinical evidence relating the use of ion beam therapy to treat major indications in active particle centres. A rationale for the use of particle therapy in each of these indications is given. In view of the limited availability of data, we discuss the necessity to conduct clinical trials. We also look forward towards the next activities to be undertaken at the HIT.

Whole-abdominal IMRT for advanced ovarian carcinoma: planning issues and feasibility.

INTRODUCTION: Despite enormous efforts to improve therapeutic strategies for patients with advanced ovarian carcinoma, outcome remains poor even with the advent cisplatinum-based chemotherapy regimen or taxanes with over 70% of patients developing local failure. Several trials were able to establish the potential benefit of adjuvant whole abdominal RT (WAI) though at the cost of sometimes marked side-effects. New technologies like IMRT have the potential of sparing normal tissues thus also potentially limiting treatment-related toxicity, hence a phase I trial was initiated to evaluate potential clinical benefit of WAI with IMRT. We intended to demonstrate that whole-abdominal IMRT is feasible and can be used in a routine clinical setting. METHODS: A water-equivalent phantom containing OARs was created simulating organ shape of the upper abdomen to investigate the necessary number of beams for the upper abdominal target irrespective of the number of segments and hence treatment times. We prescribed a total dose of 30 Gy in 1.5 Gy fractions to the median of the target. IMRT treatment plans for three patients with advanced ovarian cancer were created using 2 isocentres and between 12 and 14 beams while restricting the number of segments so as to restrict treatment times to less than 45 min. Dose to OARs such as kidneys and liver was strictly limited even below established maxima. RESULTS: In the phantom plans, no clear indication as to the optimum number of beams could be shown though there seems to be a slight trend toward a higher number of beams yielding better results. Examples demonstrating clinically inacceptable dose distributions for plans using only 9 beams. Acceptable treatment plans for real patients could be achieved using 12-14 beams and 2 isocentres. Treatment plans consisted of 264-286 segments resulting in an overall treatment time of approximately 37-45 min. Mean doses to the kidneys could be limited to 29.3% [23.1-33.2%] (right), and 26.8% [21-30.4%] (left). 50% of the liver received less than 72.4% [61-83%]. CONCLUSION: IMRT for whole abdominal irradiation in patients with advanced ovarian carcinoma is applicable and feasible though treatment planning is complex and time-consuming. There is a significant reduction of dose to critical organs by using IMRT while maintaining target volume coverage.

[What is the impact of new radiotherapy techniques?]. / Was leisten die neuen Bestrahlungstechniken?

Radiation oncology, along with surgery and chemotherapy, is one of the cornerstones in the treatment of head and neck tumors. Within the last years, this field has experienced a remarkable evolution of new technical possibilities. New imaging modalities have been introduced into radiation planning and into linear accelerators themselves. In addition, new techniques enable the tailor-made conformation of radiation beams and dose distributions to complex tumor geometries. At the same time, organs at risk can be spared, and long-term toxicities are considerably reduced. This report presents the new techniques in radiation oncology and describes the effects on new treatment options and patients' quality of life.

Treatment of non-small cell lung cancer with intensity-modulated radiation therapy in combination with cetuximab: the NEAR protocol (NCT00115518).

BACKGROUND: Even today, treatment of Stage III NSCLC still poses a serious challenge. So far, surgical resection is the treatment of choice. Patients whose tumour is not resectable or who are unfit to undergo surgery are usually referred to a combined radio-chemotherapy. However, combined radio-chemotherapeutic treatment is also associated with sometimes marked side effects but has been shown to be more efficient than radiation therapy alone. Nevertheless, there is a significant subset of patients whose overall condition does not permit administration of chemotherapy in a combined-modality treatment. It could be demonstrated though, that NSCLCs often exhibit over-expression of EGF-receptors hence providing an excellent target for the monoclonal EGFR-antagonist cetuximab (Erbitux) which has already been shown to be effective in colorectal as well as head-and-neck tumours with comparatively mild side-effects. METHODS/DESIGN: The NEAR trial is a prospective phase II feasibility study combining a monoclonal EGF-receptor antibody with loco-regional irradiation in patients with stage III NSCLC. This trial aims at testing the combination's efficacy and rate of development of distant metastases with an accrual of 30 patients. Patients receive weekly infusions of cetuximab (Erbitux) plus loco-regional radiation therapy as intensity-modulated radiation therapy. After conclusion of radiation treatment patients continue to receive weekly cetuximab for 13 more cycles. DISCUSSION: The primary objective of the NEAR trial is to evaluate toxicities and feasibility of the combined treatment with cetuximab (Erbitux) and IMRT loco-regional irradiation. Secondary objectives are remission rates, 3-year-survival and local/systemic progression-free survival.

Activation of the beta 2-adrenergic receptor involves disruption of an ionic lock between the cytoplasmic ends of transmembrane segments 3 and 6.

The movements of transmembrane segments (TMs) 3 and 6 at the cytoplasmic side of the membrane play an important role in the activation of G-protein-coupled receptors. Here we provide evidence for the existence of an ionic lock that constrains the relative mobility of the cytoplasmic ends of TM3 and TM6 in the inactive state of the beta(2)-adrenergic receptor. We propose that the highly conserved Arg-131(3.50) at the cytoplasmic end of TM3 interacts both with the adjacent Asp-130(3.49) and with Glu-268(6.30) at the cytoplasmic end of TM6. Such a network of ionic interactions has now been directly supported by the high-resolution structure of the inactive state of rhodopsin. We hypothesized that the network of interactions would serve to constrain the receptor in the inactive state, and the release of this ionic lock could be a key step in receptor activation. To test this hypothesis, we made charge-neutralizing mutations of Glu-268(6.30) and of Asp-130(3.49) in the beta(2)-adrenergic receptor. Alone and in combination, we observed a significant increase in basal and pindolol-stimulated cAMP accumulation in COS-7 cells transiently transfected with the mutant receptors. Moreover, based on the increased accessibility of Cys-285(6.47) in TM6, we provide evidence for a conformational rearrangement of TM6 that is highly correlated with the extent of constitutive activity of the different mutants. The present experimental data together with the recent high-resolution structure of rhodopsin suggest that ionic interactions between Asp/Glu(3.49), Arg(3.50), and Glu(6.30) may constitute a common switch governing the activation of many rhodopsin-like G-protein-coupled receptors.

Accuracy of magnetic resonance imaging in the diagnosis of deep vein thrombosis in asymptomatic patients with injuries of the lower extremity. A pilot study.

This is a prospective comparative study of magnetic resonance imaging (MRI) of the deep veins versus contrast venography in consecutive patients treated for various injuries to their lower extremities, showing no clinical symptoms of deep vein thrombosis. The majority of examinations referred to in this study were performed according to the following methodology: First, the patient was subjected to MRI. Subsequently, within a 24-h interval, he/she was subjected to contrast venography. The acquired results were compared in a blinded manner. The diagnostic indices for MRI were calculated on the assumption that the results of contrast venography were sure to give an accurate indication of either presence or absence of thrombosis. Thirty-six patients were included in the study, of which 27 (15 males) completed it. The overall incidence of distal deep venous thrombosis (DVT) was 22% (6/27). One patient showed extension of a crural thrombus into the popliteal vein. MRI did not detect any of the thrombi. This lack of result was ascribed to failure to fully demonstrate all segments of the crural veins. However, MRI did show three proximal thrombi in the superficial femoral vein, which were not shown by the venograms. Thus, both the sensitivity and specificity of MRI were 0%, so MRI proved to be of no value in the diagnosis of asymptomatic deep venous thrombosis in this study.

Agonist-induced conformational changes at the cytoplasmic side of transmembrane segment 6 in the beta 2 adrenergic receptor mapped by site-selective fluorescent labeling.

The environmentally sensitive, sulfhydryl-reactive, fluorescent probe N,N'-dimethyl-N-(iodoacetyl)-N'-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) ethylene-diamine (IANBD) was used as a molecular reporter of agonist-induced conformational changes in the beta(2) adrenergic receptor, a prototype hormone-activated G protein-coupled receptor. In the background of a mutant beta(2) adrenergic receptor, with a minimal number of endogenous cysteine residues, new cysteines were introduced in positions 269(6.31), 270(6.32), 271(6.33), and 272(6.34) at the cytoplasmic side of transmembrane segment (TM) 6. The resulting mutant receptors were fully functional and bound both agonists and antagonist with high affinities also upon IANBD labeling. Fluorescence spectroscopy analysis of the purified and site-selectively IANBD-labeled mutants suggested that the covalently attached fluorophore was exposed to a less polar environment at all four positions upon agonist binding. Whereas evidence for only a minor change in the molecular environment was obtained for positions 269(6.31) and 270(6.32), the full agonist isoproterenol caused clear dose-dependent and reversible increases in fluorescence emission at positions 271(6.33) and 272(6.34). The data suggest that activation of G protein-coupled receptors, which are activated by "diffusible" ligands, involves a structural rearrangement corresponding to the cytoplasmic part of TM 6. The preferred conformations of the IANBD moiety attached to the inserted cysteines were predicted by employing a computational method that incorporated the complex hydrophobic/hydrophilic environment in which the cysteines reside. Based on these preferred conformations, it is suggested that the spectral changes reflect an agonist-promoted movement of the cytoplasmic part of TM 6 away from the receptor core and upwards toward the membrane bilayer.

Biophysical characterization of the cocaine binding pocket in the serotonin transporter using a fluorescent cocaine analogue as a molecular reporter.

To explore the biophysical properties of the binding site for cocaine and related compounds in the serotonin transporter SERT, a high affinity cocaine analogue (3beta-(4-methylphenyl)tropane-2beta-carboxylic acid N-(N-methyl-N-(4-nitrobenzo-2-oxa-1,3-diazol-7-yl)ethanolamine ester hydrochloride (RTI-233); K(I) = 14 nm) that contained the environmentally sensitive fluorescent moiety 7-nitrobenzo-2-oxa-1,3-diazole (NBD) was synthesized. Specific binding of RTI-233 to the rat serotonin transporter, purified from Sf-9 insect cells, was demonstrated by the competitive inhibition of fluorescence using excess serotonin, citalopram, or RTI-55 (2beta-carbomethoxy-3beta-(4-iodophenyl)tropane). Moreover, specific binding was evidenced by measurement of steady-state fluorescence anisotropy, showing constrained mobility of bound RTI-233 relative to RTI-233 free in solution. The fluorescence of bound RTI-233 displayed an emission maximum (lambda(max)) of 532 nm, corresponding to a 4-nm blue shift as compared with the lambda(max) of RTI-233 in aqueous solution and corresponding to the lambda(max) of RTI-233 in 80% dioxane. Collisional quenching experiments revealed that the aqueous quencher potassium iodide was able to quench the fluorescence of RTI-233 in the binding pocket (K(SV =) 1.7 m(-)(1)), although not to the same extent as free RTI-233 (K(SV =) 7.2 m(-)(1)). Conversely, the hydrophobic quencher 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) quenched the fluorescence of bound RTI-233 more efficiently than free RTI-233. These data are consistent with a highly hydrophobic microenvironment in the binding pocket for cocaine-like uptake inhibitors. However, in contrast to what has been observed for small-molecule binding sites in, for example, G protein-coupled receptors, the bound cocaine analogue was still accessible for aqueous quenching and, thus, partially exposed to solvent.

Mutation of a highly conserved aspartic acid in the beta2 adrenergic receptor: constitutive activation, structural instability, and conformational rearrangement of transmembrane segment 6.

Movements of transmembrane segments (TMs) 3 and 6 play a key role in activation of G protein-coupled receptors. However, the underlying molecular processes that govern these movements, and accordingly control receptor activation, remain unclear. To elucidate the importance of the conserved aspartic acid (Asp-130) in the Asp-Arg-Tyr motif of the beta2 adrenergic receptor (beta2AR), we mutated this residue to asparagine (D130N) to mimic its protonated state, and to alanine (D130A) to fully remove the functionality of the side chain. Both mutants displayed evidence of constitutive receptor activation. In COS-7 cells expressing either D130N or D130A, basal levels of cAMP accumulation were clearly elevated compared with cells expressing the wild-type beta2AR. Incubation of COS-7 cell membranes or purified receptor at 37 degrees C revealed also a marked structural instability of both mutant receptors, suggesting that stabilizing intramolecular constraints had been disrupted. Moreover, we obtained evidence for a conformational rearrangement by mutation of Asp-130. In D130N, a cysteine in TM 6, Cys-285, which is not accessible in the wild-type beta2AR, became accessible to methanethiosulfonate ethylammonium, a charged, sulfhydryl-reactive reagent. This is consistent with a counterclockwise rotation or tilting of TM 6 and provides for the first time structural evidence linking charge-neutralizing mutations of the aspartic acid in the DRY motif to the overall conformational state of the receptor. We propose that protonation of the aspartic acid leads to release of constraining intramolecular interactions, resulting in movements of TM 6 and, thus, conversion of the receptor to the active state.

Human DNA topoisomerase I-mediated cleavage and recombination of duck hepatitis B virus DNA in vitro.

In this study, we report that eukaryotic topoisomerase I (top1) can linearize the open circular DNA of duck hepatitis B virus (DHBV). Using synthetic oligonucleotides mimicking the three-strand flap DR1 region of the DHBV genome, we found that top1 cleaves the DNA plus strand in a suicidal manner, which mimics the linearization of the virion DNA. We also report that top1 can cleave the DNA minus strand at specific sites and can linearize the minus strand via a non-homologous recombination reaction. These results are consistent with the possibility that top1 can act as a DNA endo-nuclease and strand transferase and play a role in the circularization, linearization and possibly integration of viral replication intermediates.