How to manage renal masses in kidney transplant recipients? A collaborative review by the EAU-YAU kidney transplantation and renal cancer working groups

INTRODUCTION

Kidney transplant (KT) recipients have a four-times higher risk of renal malignancies compared to general population. As these patients frequently harbor bilateral or multifocal tumors, the management of renal masses is still under debate.

OBJECTIVE

To explore the current management of the native kidney masses in KT patients.

ACQUISITION OF EVIDENCE

We performed a literature search on MEDLINE/PubMed database. A number of 34 studies were included in the present review.

SYNTHESIS OF EVIDENCE

In frail patients with renal masses below 3 cm, active surveillance is a feasible alternative. Nephron-sparing surgery is not justified for masses in the native kidney. Radical nephrectomy is the standard treatment for post-transplant renal tumors of the native kidneys in KT recipients, with laparoscopic techniques leading to significantly less perioperative complication rates as compared to the open approach. Concurrent bilateral native nephrectomy at the time of transplantation can be considered in patients with renal mass and polycystic kidney disease, especially if no residual urinary output is present. Patients with localized disease and successful radical nephrectomy do not require immunosuppression adjustment. In metastatic cases, mTOR agents can ensure efficient antitumoral response, while maintaining proper immunosuppression in order to protect the graft.

CONCLUSIONS

Post-transplant renal cancer of the native kidneys is a frequent occurrence. Radical nephrectomy is most frequently performed for localized renal masses. A standardized and widely-approved screening strategy for malignancies of native renal units is yet to be implemented.

Single-shot terahertz time-domain spectrometer using 1550 nm probe pulses and diversity electro-optic sampling

Classical terahertz spectroscopy usually requires the use of Fourier transform or Time-Domain Spectrometers. However, these classical techniques become impractical when using recent high peak power terahertz sources - based on intense lasers or accelerators - which operate at low repetition rate. We present and test the design of a novel Time-Domain Spectrometer, that is capable of recording a whole terahertz spectrum at each shot of the source, and that uses a 1550 nm probe fiber laser. Single-shot operation is obtained using chirped-pulse electro-optic sampling in Gallium Arsenide, and high bandwidth is obtained by using the recently introduced Diversity Electro-Optic Sampling (DEOS) method. We present the first real-time measurements of THz spectra at the TeraFERMI Coherent Transition Radiation source. The system achieves 2.5 THz bandwidth with a maximum dynamic range reaching up to 25 dB. By reducing the required measurement time from minutes to a split-second, this strategy dramatically expands the application range of high power low-repetition rate THz sources.

Colon sparing resection versus extended colectomy for left-sided obstructing colon cancer with caecal ischaemia or perforation: a nationwide study from the French Surgical Association

AIM

It is not known whether patients with obstructive left colon cancer (OLCC) with caecal ischaemia or diastatic perforation (defined as a blowout of the caecal wall related to colonic overdistension) should undergo a (sub)total colectomy (STC) or an ileo-caecal resection with double-barrelled ileo-colostomy. We aimed to compare the results of these two strategies.

METHOD

From 2000 to 2015, 1220 patients with OLCC underwent surgery by clinicians who were members of the French Surgical Association. Of these cases, 201 (16%) were found to have caecal ischaemia or diastatic perforation intra-operatively: 174 patients (87%) underwent a STC (extended colectomy group) and 27 (13%) an ileo-caecal resection with double-end stoma (colon-sparing group). Outcomes were compared retrospectively.

RESULTS

In the extended colectomy group, 95 patients (55%) had primary anastomosis and 79 (45%) had a STC with an end ileostomy. In the colon-sparing group, 10 patients (37%) had simultaneous resection of their primary tumour with segmental colectomy and an anastomosis which was protected by a double-barrelled ileo-colostomy. The demographic data for the two groups were comparable. Median operative time was longer in the STC group (P = 0.0044). There was a decrease in postoperative mortality (7% vs 12%, P = 0.75) and overall morbidity (56% vs 67%, P = 0.37) including surgical (30% vs 40%, P = 0.29) and severe complications (17% vs 27%, P = 0.29) in the colon-sparing group, although these differences did not reach statistical significance. Cumulative morbidity included all surgical stages and the rate of permanent stoma was 66% and 37%, respectively, with no significant difference between the two groups. Overall survival and disease-free survival were similar between the two groups.

CONCLUSION

The colon-sparing strategy may represent a valid and safe alternative to STC in OLCC patients with caecal ischaemia or diastatic perforation.

Tunable High Spatio-Spectral Purity Undulator Radiation from a Transported Laser Plasma Accelerated Electron Beam

Undulator based synchrotron light sources and Free Electron Lasers (FELs) are valuable modern probes of matter with high temporal and spatial resolution. Laser Plasma Accelerators (LPAs), delivering GeV electron beams in few centimeters, are good candidates for future compact light sources. However the barriers set by the large energy spread, divergence and shot-to-shot fluctuations require a specific transport line, to shape the electron beam phase space for achieving ultrashort undulator synchrotron radiation suitable for users and even for achieving FEL amplification. Proof-of-principle LPA based undulator emission, with strong electron focusing or transport, does not yet exhibit the full specific radiation properties. We report on the generation of undulator radiation with an LPA beam based manipulation in a dedicated transport line with versatile properties. After evidencing the specific spatio-spectral signature, we tune the resonant wavelength within 200-300 nm by modification of the electron beam energy and the undulator field. We achieve a wavelength stability of 2.6%. We demonstrate that we can control the spatio-spectral purity and spectral brightness by reducing the energy range inside the chicane. We have also observed the second harmonic emission of the undulator.

Thirty-day mortality after emergency surgery for obstructing colon cancer: survey and dedicated score from the French Surgical Association

AIM

The aim was to define risk factors for postoperative mortality in patients undergoing emergency surgery for obstructing colon cancer (OCC) and to propose a dedicated score.

METHOD

From 2000 to 2015, 2325 patients were treated for OCC in French surgical centres by members of the French National Surgical Association. A multivariate analysis was performed for variables with P value ≤ 0.20 in the univariate analysis for 30-day mortality. Predictive performance was assessed by the area under the receiver operating characteristic curve.

RESULTS

A total of 1983 patients were included. Thirty-day postoperative mortality was 7%. Multivariate analysis found five significant independent risk factors: age ≥ 75 (P = 0.013), American Society of Anesthesiologists (ASA) score ≥ III (P = 0.027), pulmonary comorbidity (P = 0.0002), right-sided cancer (P = 0.047) and haemodynamic failure (P < 0.0001). The odds ratio for risk of postoperative death was 3.42 with one factor, 5.80 with two factors, 15.73 with three factors, 29.23 with four factors and 77.25 with five factors. The discriminating capacity in predicting 30-day postoperative mortality was 0.80.

CONCLUSION

Thirty-day postoperative mortality after emergency surgery for OCC is correlated with age, ASA score, pulmonary comorbidity, site of tumour and haemodynamic failure, with a specific score ranging from 0 to 5.

[Stretching and chylothorax]

INTRODUCTION

Chylothorax is a rare cause of pleural effusion. The most common causes are iatrogenic or medical. We report an unusual and rare cause of bilateral chylothorax.

CASE REPORT

A 73-year-old woman with no past history was admitted to the emergency department for sudden onset of dyspnoea. Chest X-ray and thoracic CT scan revealed large bilateral pleural effusions. Analysis of the fluid revealed a chylothorax. The patient was treated by chest tube drainage and a fat free (medium chain triglyceride) diet. This led to drying up of the effusions and rapid discharge. Complementary imaging examinations with chest-abdomen-pelvis CT, PET CT and pelvic MRI did not reveal any underlying cause. The final diagnosis was bilateral traumatic chylothorax caused by tearing of the thoracic duct during stretching exercises.

CONCLUSION

Following a literature review, similar cases with the same clinical presentation were found. Combined treatment with thoracic drainage and medium chain triglyceride diet was effective in drying up the effusions. Our diagnosis was a diagnosis of exclusion. It is important to exclude a medical cause by thorough investigation.

Symmetry breakdown of electron emission in extreme ultraviolet photoionization of argon

Short wavelength free-electron lasers (FELs), providing pulses of ultrahigh photon intensity, have revolutionized spectroscopy on ionic targets. Their exceptional photon flux enables multiple photon absorptions within a single femtosecond pulse, which in turn allows for deep insights into the photoionization process itself as well as into evolving ionic states of a target. Here we employ ultraintense pulses from the FEL FERMI to spectroscopically investigate the sequential emission of electrons from gaseous, atomic argon in the neutral as well as the ionic ground state. A pronounced forward-backward symmetry breaking of the angularly resolved emission patterns with respect to the light propagation direction is experimentally observed and theoretically explained for the region of the Cooper minimum, where the asymmetry of electron emission is strongly enhanced. These findings aim to originate a better understanding of the fundamentals of photon momentum transfer in ionic matter.

Control of H_{2} Dissociative Ionization in the Nonlinear Regime Using Vacuum Ultraviolet Free-Electron Laser Pulses

The role of the nuclear degrees of freedom in nonlinear two-photon single ionization of H_{2} molecules interacting with short and intense vacuum ultraviolet pulses is investigated, both experimentally and theoretically, by selecting single resonant vibronic intermediate neutral states. This high selectivity relies on the narrow bandwidth and tunability of the pulses generated at the FERMI free-electron laser. A sustained enhancement of dissociative ionization, which even exceeds nondissociative ionization, is observed and controlled as one selects progressively higher vibronic states. With the help of ab initio calculations for increasing pulse durations, the photoelectron and ion energy spectra obtained with velocity map imaging allow us to identify new photoionization pathways. With pulses of the order of 100 fs, the experiment probes a timescale that lies between that of ultrafast dynamical processes and that of steady state excitations.

Soft X-Ray Second Harmonic Generation as an Interfacial Probe

Nonlinear optical processes at soft x-ray wavelengths have remained largely unexplored due to the lack of available light sources with the requisite intensity and coherence. Here we report the observation of soft x-ray second harmonic generation near the carbon K edge (∼284  eV) in graphite thin films generated by high intensity, coherent soft x-ray pulses at the FERMI free electron laser. Our experimental results and accompanying first-principles theoretical analysis highlight the effect of resonant enhancement above the carbon K edge and show the technique to be interfacially sensitive in a centrosymmetric sample with second harmonic intensity arising primarily from the first atomic layer at the open surface. This technique and the associated theoretical framework demonstrate the ability to selectively probe interfaces, including those that are buried, with elemental specificity, providing a new tool for a range of scientific problems.

Passive Linearization of the Magnetic Bunch Compression Using Self-Induced Fields

In linac-driven free-electron lasers, colliders, and energy recovery linacs, a common way to compress the electron bunch to kiloampere level is based upon the implementation of a magnetic dispersive element that converts particle energy deviation into a path-length difference. Nonlinearities of such a process are usually compensated by enabling a high harmonic rf structure properly tuned in amplitude and phase. This approach is however not straightforward, e.g., in C-band and X-band linacs. In this Letter we demonstrate that the longitudinal self-induced field excited by the electron beam itself is able to linearize the compression process without any use of high harmonic rf structure. The method is implemented at the FERMI linac, with the resulting high quality beam used to drive the seeded free-electron laser during user experiments.

Observation and Control of Laser-Enabled Auger Decay

Single-photon laser-enabled Auger decay (spLEAD) is predicted theoretically [B. Cooper and V. Averbukh, Phys. Rev. Lett. 111, 083004 (2013)PRLTAO0031-900710.1103/PhysRevLett.111.083004] and here we report its first experimental observation in neon. Using coherent, bichromatic free-electron laser pulses, we detect the process and coherently control the angular distribution of the emitted electrons by varying the phase difference between the two laser fields. Since spLEAD is highly sensitive to electron correlation, this is a promising method for probing both correlation and ultrafast hole migration in more complex systems.

Warm summers and moderate winter precipitation boost Rhododendron ferrugineum L. growth in the Taillefer massif (French Alps)

Rhododendron ferrugineum L. is a widespread dwarf shrub species growing in high-elevation, alpine environments of the Western European Alps. For this reason, analysis of its growth rings offers unique opportunities to push current dendrochronological networks into extreme environments and way beyond the treeline. Given that different species of the same genus have been successfully used in tree-ring investigations, notably in the Himalayas where Rhododendron spp. has proven to be a reliable climate proxy, this study aims at (i) evaluating the dendroclimatological potential of R. ferrugineum and at (ii) determining the major limiting climate factor driving its growth. To this end, 154 cross-sections from 36 R. ferrugineum individuals have been sampled above local treelines and at elevations from 1800 to 2100masl on northwest-facing slopes of the Taillefer massif (French Alps). We illustrate a 195-year-long standard chronology based on growth-ring records from 24 R. ferrugineum individuals, and document that the series is well-replicated for almost one century (1920-2015) with an Expressed Population Signal (EPS) >0.85. Analyses using partial and moving 3-months correlation functions further highlight that growth of R. ferrugineum is governed by temperatures during the growing season (May-July), with increasingly higher air temperatures favoring wider rings, a phenomenon which is well known from dwarf shrubs growing in circum-arctic tundra ecosystems. Similarly, the negative effect of January-February precipitation on radial growth of R. ferrugineum, already observed in the Alps on juniper shrubs, is interpreted as a result of shortened growing seasons following snowy winters. We conclude that the strong and unequivocal signals recorded in the fairly long R. ferrugineum chronologies can indeed be used for climate-growth studies as well as for the reconstruction of climatic fluctuations in Alpine regions beyond the upper limits of present-day forests.

Direct Observation of Spatiotemporal Dynamics of Short Electron Bunches in Storage Rings

In recent synchrotron radiation facilities, the use of short (picosecond) electron bunches is a powerful method for producing giant pulses of terahertz coherent synchrotron radiation. Here we report on the first direct observation of these pulse shapes with a few picoseconds resolution, and of their dynamics over a long time. We thus confirm in a very direct way the theories predicting an interplay between two physical processes. Below a critical bunch charge, we observe a train of identical THz pulses (a broadband Terahertz comb) stemming from the shortness of the electron bunches. Above this threshold, a large part of the emission is dominated by drifting structures, which appear through spontaneous self-organization. These challenging single-shot THz recordings are made possible by using a recently developed photonic time stretch detector with a high sensitivity. The experiment has been realized at the SOLEIL storage ring.

Cultivation of an immobilized (hyper)thermophilic marine microbial community in a bioreactor

Cultivation in a bioreactor of immobilized deep-sea hydrothermal microbial community was tested in order to assess the stability and reactivity of this new system. A community composed of eight hydrothermal strains was entrapped in a polymer matrix that was used to inoculate a continuous culture in a gas-lift bioreactor. The continuous culture was performed for 41 days at successively 60°C, 55°C, 60°C, 85°C and 60°C, at pH 6.5, in anaerobic condition and constant dilution rate. Oxic stress and pH variations were tested at the beginning of the incubation. Despite these detrimental conditions, three strains including two strict anaerobes were maintained in the bioreactor. High cell concentrations (3 × 10(8) cells mL(-1)) and high ATP contents were measured in both liquid fractions and beads. Cloning-sequencing and qPCR revealed that Bacillus sp. dominated at the early stage, and was later replaced by Thermotoga maritima and Thermococcus sp. Acetate, formate and propionate concentrations varied simultaneously in the liquid fractions. These results demonstrate that these immobilized cells were reactive to culture conditions. They were protected inside the beads during the stress period and released in the liquid fraction when conditions were more favorable. This confirms the advantage of immobilization that highlights the resilience capacity of certain hydrothermal microorganisms after a stress period.

Multicolor High-Gain Free-Electron Laser Driven by Seeded Microbunching Instability

Laser-heater systems are essential tools to control and optimize high-gain free-electron lasers (FELs) working in the x-ray wavelength range. Indeed, these systems induce a controllable increase of the energy spread of the electron bunch. The heating suppresses longitudinal microbunching instability which otherwise would limit the FEL performance. Here, we demonstrate that, through the action of the microbunching instability, a long-wavelength modulation of the electron beam induced by the laser heater at low energy can persist until the beam entrance into the undulators. This coherent longitudinal modulation is exploited to control the FEL spectral properties, in particular, multicolor extreme-ultraviolet FEL pulses can be generated through a frequency mixing of the modulations produced by the laser heater and the seed laser in the electron beam. We present an experimental demonstration of this novel configuration carried out at the FERMI FEL.

Observing microscopic structures of a relativistic object using a time-stretch strategy

Emission of light by a single electron moving on a curved trajectory (synchrotron radiation) is one of the most well-known fundamental radiation phenomena. However experimental situations are more complex as they involve many electrons, each being exposed to the radiation of its neighbors. This interaction has dramatic consequences, one of the most spectacular being the spontaneous formation of spatial structures inside electrons bunches. This fundamental effect is actively studied as it represents one of the most fundamental limitations in electron accelerators, and at the same time a source of intense terahertz radiation (Coherent Synchrotron Radiation, or CSR). Here we demonstrate the possibility to directly observe the electron bunch microstructures with subpicosecond resolution, in a storage ring accelerator. The principle is to monitor the terahertz pulses emitted by the structures, using a strategy from photonics, time-stretch, consisting in slowing-down the phenomena before recording. This opens the way to unpreceeded possibilities for analyzing and mastering new generation high power coherent synchrotron sources.

The FERMI free-electron lasers

FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and is now in user operation with its first FEL line, FEL-1, covering the wavelength range between 100 and 20 nm. The second FEL line, FEL-2, a high-gain harmonic generation double-stage cascade covering the wavelength range 20-4 nm, has also completed commissioning and the first user call has been recently opened. An overview of the typical operating modes of the facility is presented.

Microbunching instability in relativistic electron bunches: direct observations of the microstructures using ultrafast YBCO detectors

Relativistic electron bunches circulating in accelerators are subjected to a dynamical instability leading to microstructures at millimeter to centimeter scale. Although this is a well-known fact, direct experimental observations of the structures, or the field that they emit, remained up to now an open problem. Here, we report the direct, shot-by-shot, time-resolved recording of the shapes (including envelope and carrier) of the pulses of coherent synchrotron radiation that are emitted, and that are a "signature" of the electron bunch microstructure. The experiments are performed on the UVSOR-III storage ring, using electrical field sensitive YBa2Cu3O(7-x) thin-film ultrafast detectors. The observed patterns are subjected to permanent drifts, that can be explained from a reasoning in phase space, using macroparticle simulations.

[Contralateral breast outcome after breast reconstruction for carcinoma]

OBJECTIF: Since the treatment of breast cancer must be followed by a rigorous surveillance of the contralateral breast, especially in breast reconstruction context, we sought to determine contralateral breast cancer frequency after breast reconstruction during the ulterior surveillance.

PATIENTS AND METHODS

Retrospective cohort survey of 273 breast reconstructions led at Tours regional and university hospital. Cumulative incidence of sequential contralateral breast cancer has been evaluated.

RESULTS

For 6.6 follow-up, the prevalence was 1.8% and cumulated incidence at 4.6 ‰ person/years.

DISCUSSION AND CONCLUSION

The probability of localization to contralateral breast after a primitive tumor of the breast is raised. The diagnosis of a sequential cancer must not be delayed by mammaplasty scars overhauls.