CEA response is associated with tumor response and survival in patients with KRAS exon 2 wild-type and extended RAS wild-type metastatic colorectal cancer receiving first-line FOLFIRI plus cetuximab or bevacizumab (FIRE-3 trial)

BACKGROUND

To examine the relation of carcinoembryonic antigen (CEA) response with tumor response and survival in patients with (K)RAS wild-type metastatic colorectal cancer receiving first-line chemotherapy in the FIRE-3 trial comparing FOLFIRI plus cetuximab versus FOLFIRI plus bevacizumab.

PATIENTS AND METHODS

CEA response assessed as the percentage of CEA decrease from baseline to nadir was evaluated for its association with tumor response and survival. Receiver operating characteristic analysis revealed an optimal cut-off value of 75% using the maximum of sensitivity and specificity for CEA response to discriminate CEA responders from non-responders. In addition, the time to CEA nadir was calculated.

RESULTS

Of 592 patients in the intent-to-treat population, 472 were eligible for analysis of CEA (cetuximab arm: 230 and bevacizumab arm: 242). Maximal relative CEA decrease (%) significantly (P = 0.003) differed between the cetuximab arm (median 83.0%; IQR 40.9%-94.7%) and the bevacizumab arm (median 72.3%; IQR 26.3%-91.0%). In a longitudinal analysis, the CEA decrease occurred faster in the cetuximab arm and was greater than in the bevacizumab arm at all evaluated time points until 56 weeks after treatment start. CEA nadir occurred after 3.3 months (cetuximab arm) and 3.5 months (bevacizumab arm), (P = 0.49). In the cetuximab arm, CEA responders showed a significantly longer progression-free survival [11.8 versus 7.4 months; hazard ratio (HR) 1.53; 95% Cl, 1.15-2.04; P = 0.004] and longer overall survival (36.6 versus 21.3 months; HR 1.73; 95% Cl, 1.24-2.43; P = 0.001) than CEA non-responders. Analysis of extended RAS wild-type patients revealed similar results.

CONCLUSION

In the FIRE-3 trial, CEA decrease was significantly faster and greater in the cetuximab arm than in the bevacizumab arm and correlated with the prolonged survival observed in patients receiving FOLFIRI plus cetuximab.

CLINICAL TRIALS NUMBER

NCT00433927 (ClinicalTrials.gov); AIO KRK0306 FIRE-3.

Hypertriglyceridemia in an outpatient department--Significance as an atherosclerotic risk factor

BACKGROUND

Although a relationship between elevated triglycerides (TG) and cardiovascular diseases is generally accepted, its extent is still discussed. This retrospective study analyzed the incidence of cardiovascular events (CVE) and pancreatitis as well as the therapeutic regimen in patients being treated for hypertriglyceridemia (HTG) at an outpatient department.

METHODS

The cohort included 183 patients with mild and 49 patients with severe HTG; subgroups were formed and compared according to gender, presence of metabolic vascular syndrome (MVS) and lipid values.

RESULTS

Patients in this study seem to have had CVE at younger age than reported event rates in the general population. TG levels, rates of CVE and pancreatitis were reduced in all groups during therapy, which could be linked to use of omega-3 fatty acids and fibrates. Patients with persisting severe HTG as a result of incompliance showed massive risk for pancreatitis.

CONCLUSION

Although no significant association between TG levels and CVE could be established, the combination of HTG and other cardiovascular risk factors such as MVS seems to be especially dangerous. The lipid-lowering drug therapy appeared to be effective with respect to CVE and pancreatitis incidence.

[Indications for Surgical Correction of Degenerative Spondylolisthesis]

There is no general consensus about indications for surgical treatment of degenerative spondylolisthesis. This is--in part--due to a paucity of knowledge of its natural history and outcomes of conservative treatment, as well as a relatively small number of sufficiently powered outcome studies for surgical treatment. We aim to provide an overview of current surgical techniques and deduce indications based on two simple principles: presence of neurological deficits and instability. Today, decompression and instrumented fusion is the standard of care. However, the complete armamentarium of possible treatment options should be carefully considered, and the adequate procedures and instruments used should be chosen individually, when a decision to operate is made.

Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape of normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.

Application of the local effect model to predict DNA double-strand break rejoining after photon and high-LET irradiation

In the recent version of the local effect model (LEM), the biological effects of ionising radiation can be well described trough the consideration of DNA double-strand breaks (DSB) clustering at the micrometre scale. Assuming a giant-loop organisation for the chromatin higher-order structure, two classes of DSB are defined, namely isolated (iDSB) and clustered DSB (cDSB), according to whether exactly one or more than one DSB are induced in a loop, respectively. Here, a DSB kinetic rejoining model based on the LEM is applied to the description of two specific aspects of DSB rejoining, namely the dose dependence of the rejoining capacity after photon radiation and the residual damage observed at late times after ion irradiation. Based on the hypothesis that iDSB and cDSB can be associated to the fast and slow components of rejoining, the model is able to reproduce the experimental data, therefore supporting the relevance of micrometre scale clustering of damage for photon radiation as well as for high-LET radiation.

Simulation of DSB yield for high LET radiation

A simulation approach for the calculation of the LET-dependent yield of double-strand breaks (DSB) is presented. The model considers DSB formed as two close-lying single-strand breaks (SSB), whose formation is mediated by both intra-track processes (single electrons) or at local doses larger than about 1000 Gy in particle tracks also by electron inter-track processes (two independent electron tracks). A Monte Carlo algorithm and an analytical formula for the DSB yield are presented. The approach predicts that the DSB yield is enhanced after charged particle irradiation of high LET compared with X-ray or gamma radiation. It is used as an inherent part of the local effect model, which is applied to estimate the relative biological effectiveness of high LET radiation.

Sensitivity of the Giant LOop Binary LEsion (GLOBLE) cell survival model on parameters characterising dose rate effects

The sensitivity of the Giant LOop Binary LEsion model for cell survival probabilities after arbitrary photon irradiation schedules on its parameters is presented. Since these parameters are closely linked to observable features of cell repair, the modelled influence of the parameters on cell survival gives indications about the relation between cell line-specific repair characteristics and the radiation response. To visualise the general findings about the impact of parameter changes on cell survival probabilities, survival curves for an exemplary cell line are shown. Furthermore, the relative change in the effect of radiation after a change in parameter values is investigated over the range of doses and dose rates usually applied in cell survival experiments.

Correction of the deterministic part of space-charge interaction in momentum microscopy of charged particles

Ultrahigh spectral brightness femtosecond XUV and X-ray sources like free electron lasers (FEL) and table-top high harmonics sources (HHG) offer fascinating experimental possibilities for analysis of transient states and ultrafast electron dynamics. For electron spectroscopy experiments using illumination from such sources, the ultrashort high-charge electron bunches experience strong space-charge interactions. The Coulomb interactions between emitted electrons results in large energy shifts and severe broadening of photoemission signals. We propose a method for a substantial reduction of the effect by exploiting the deterministic nature of space-charge interaction. The interaction of a given electron with the average charge density of all surrounding electrons leads to a rotation of the electron distribution in 6D phase space. Momentum microscopy gives direct access to the three momentum coordinates, opening a path for a correction of an essential part of space-charge interaction. In a first experiment with a time-of-flight momentum microscope using synchrotron radiation at BESSY, the rotation in phase space became directly visible. In a separate experiment conducted at FLASH (DESY), the energy shift and broadening of the photoemission signals were quantified. Finally, simulations of a realistic photoemission experiment including space-charge interaction reveals that a gain of an order of magnitude in resolution is possible using the correction technique presented here.

Orbital-specific mapping of the ligand exchange dynamics of Fe(CO)5 in solution

Transition-metal complexes have long attracted interest for fundamental chemical reactivity studies and possible use in solar energy conversion. Electronic excitation, ligand loss from the metal centre, or a combination of both, creates changes in charge and spin density at the metal site that need to be controlled to optimize complexes for photocatalytic hydrogen production and selective carbon-hydrogen bond activation. An understanding at the molecular level of how transition-metal complexes catalyse reactions, and in particular of the role of the short-lived and reactive intermediate states involved, will be critical for such optimization. However, suitable methods for detailed characterization of electronic excited states have been lacking. Here we show, with the use of X-ray laser-based femtosecond-resolution spectroscopy and advanced quantum chemical theory to probe the reaction dynamics of the benchmark transition-metal complex Fe(CO)5 in solution, that the photo-induced removal of CO generates the 16-electron Fe(CO)4 species, a homogeneous catalyst with an electron deficiency at the Fe centre, in a hitherto unreported excited singlet state that either converts to the triplet ground state or combines with a CO or solvent molecule to regenerate a penta-coordinated Fe species on a sub-picosecond timescale. This finding, which resolves the debate about the relative importance of different spin channels in the photochemistry of Fe(CO)5 (refs 4, 16 - 20), was made possible by the ability of femtosecond X-ray spectroscopy to probe frontier-orbital interactions with atom specificity. We expect the method to be broadly applicable in the chemical sciences, and to complement approaches that probe structural dynamics in ultrafast processes.

[Evaluation of a Micro-Manipulator for Middle Ear Surgery: A Preclinical Trial]

BACKGROUND

Microsurgical preparation is limited by geometric and mechanical constraints. In preparation for clinical use, this study investigates performance, ease of handling and precision of a novel manipulator concept for microsurgery.

MATERIAL AND METHODS

A group of 15 ENT experienced doctors, as well as a group of 17 medical students with low/non surgical experience participated in the study. Each of the subjects carried out 4 trials of simulated surgeries on a phantom with built-in force sensors. The task was to apply a defined force between 1.5 and 2 N using a Fisch micro perforator, 16 cm length, 0.4 mm (Storz) targeting holes with a diameter of 0.5 mm. For comparison, the Fisch micro perforator was moved manually or with the manipulator.

RESULTS

Assessing the total number of errors proved a significantly lower error number (p<0.0001) and an improvement of the accuracy of 76% with the manipulator. The time requirement for the procedure with the micro manipulator is on average 2-3 times higher than with manual control (p<0.0001). But it is notable that this time requirement significantly decreases with training (p<0.0001).

CONCLUSION

The study shows a significant reduction in the number of errors by using a new manipulator concept compared to the non-augmented human hand in an experimental setup. We observed a significant learning effect when subjects applied the micro manipulator, resulting in reduction of the time requirement while maintaining a constant number of errors.

A simplified scheme for generating narrow-band mid-ultraviolet laser radiation

We report on the development and characterization of continuous, narrow-band, and tunable laser systems that use direct second-harmonic generation from blue and green diode lasers with an output power level of up to 11.1 mW in the mid-ultraviolet. One of our laser systems was tuned to the mercury 6(1)S0 → 6(3)P1 intercombination line at 253.7 nm. We could perform Doppler-free saturation spectroscopy on this line and were able to lock our laser to the transition frequency on long time scales.

Vertical-flow constructed wetlands treating domestic wastewater contaminated by hydrocarbons

The aim was to compare the impact of different design (aggregate size) and operational (contact time, empty time and chemical oxygen demand (COD) loading) variables on the long-term and seasonal performance of vertical-flow constructed wetland filters operated in tidal flow mode before and after a one-off spill of diesel. Ten different vertical-flow wetland systems were planted with Phragmites australis (Cav.) Trin. ex Steud. (common reed). Approximately 130 g of diesel fuel was poured into four wetland filters. Before the spill, compliance with secondary wastewater treatment standards was achieved by all wetlands regarding ammonia-nitrogen (NH4-N), nitrate-nitrogen (NO₃-N) and suspended solids (SS), and non-compliance was recorded for biochemical oxygen demand and ortho-phosphate-phosphorus (PO₄-P). Higher COD inflow concentrations had a significantly positive impact on the treatment performance for COD, PO₄-P and SS. The wetland with the largest aggregate size had the lowest mean NO₃-N outflow concentration. However, the results were similar regardless of aggregate size and resting time for most variables. Clear seasonal outflow concentration trends were recorded for COD, NH4-N and NO₃-N. No filter clogging was observed. The removal efficiencies dropped for those filters impacted by the diesel spill. The wetlands system shows a good performance regarding total petroleum hydrocarbon (TPH) removal.

X-ray crystal spectrometer upgrade for ITER-like wall experiments at JET

The high resolution X-Ray crystal spectrometer at the JET tokamak has been upgraded with the main goal of measuring the tungsten impurity concentration. This is important for understanding impurity accumulation in the plasma after installation of the JET ITER-like wall (main chamber: Be, divertor: W). This contribution provides details of the upgraded spectrometer with a focus on the aspects important for spectral analysis and plasma parameter calculation. In particular, we describe the determination of the spectrometer sensitivity: important for impurity concentration determination.