Safe use of contrast media in myasthenia gravis: systematic review and updated European Society of Urogenital Radiology Contrast Media Safety Committee guidelines.

OBJECTIVES: It is uncertain whether modern iodine-based or gadolinium-based contrast media (CM) administration can lead to increased symptoms in patients with myasthenia gravis. METHODS: A systematic search in Medline was conducted for studies describing the symptomatology of myasthenia gravis patients before and after receiving intravenous (IV) CM and having a matched control group of myasthenia gravis patients who did not receive IV CM. RESULTS: Three retrospective studies were selected with a total of 374 myasthenia gravis patients who received iodine-based CM and a total of 313 myasthenia gravis patients who underwent unenhanced CT and served as controls. Pooling of the data from the three retrospective studies showed that in 23 of 374 patients, increased symptoms after iodine-based CM administration were described (6.1%). Increased symptomatology also occurred in 11 of 313 patients after unenhanced CT (3.5%). When looking more deeply into the data of the three studies, conflicting results were found, as two articles did not find any relationship between CM and myasthenia gravis symptoms. The remaining study only found a significant increase in symptomatology within 1 day after CT scanning: seven patients (6.3%) in the contrast-enhanced CT group and one patient (0.6%) in the unenhanced CT group (p = 0.01). CONCLUSIONS: There is limited evidence on the relationship between CM and myasthenia gravis symptoms. In the vast majority of myasthenia gravis patients, CM are safe. Probably, in less than 5% of the patients, iodine-based CM administration may lead to increased severity of the symptoms within the first 24 h after administration. CLINICAL RELEVANCE STATEMENT: Be aware that intravenous administration of iodine-based contrast media can lead to an increase of symptoms in patients with myasthenia gravis within the first 24 h. This can probably happen in less than 5% of the patients. KEY POINTS: • It is unclear whether modern contrast media can lead to increased symptoms in myasthenia gravis patients after intravenous administration. • There seems to be a small risk of increased myasthenia gravis symptoms within 24 h after intravenous administration of iodine-based contrast media, probably in less than 5% of the administrations. • Gadolinium-based contrast media are safe for patients with myasthenia gravis.

Role of the three-dimensional printing technology incomplex laparoscopic renal surgery: a renal tumor in a horseshoe kidney.

PURPOSE: To report our initial experience using a patient-specific 3D-printed renal tumor model for the surgical planning of a complex heminephrectomy in a horseshoe kidney. MATERIALS AND METHODS: We selected a clinical case for a complex laparoscopic surgery consisting in a 53 year-old male presenting a local recurrence of a renal tumor in a horseshoe kidney with aberrant vascularisation previously treated with a laparoscopic partial nephrectomy. He is now proposed for a laparoscopic left heminephrectomy. Along with conventional imaging, a real-size 3D-printed renal model was used to plan de surgical approach. The perioperative experience of the surgical team was recorded. RESULTS: The surgical team found the patient-specifi c 3D printed model useful for a better understanding of the anatomy and an easier surgical planning. CONCLUSION: The use of patient-specifi c 3D-printed renal models seem to be helpful for the surgical planning in complex renal tumors.

Role of the three-dimensional printing technology in complex laparoscopic renal surgery: a renal tumor in a horseshoe kidney

ABSTRACT Purpose: To report our initial experience using a patient-specific 3D-printed renal tumor model for the surgical planning of a complex heminephrectomy in a horseshoe kidney. Materials and Methods: We selected a clinical case for a complex laparoscopic surgery consisting in a 53 year-old male presenting a local recurrence of a renal tumor in a horseshoe kidney with aberrant vascularisation previously treated with a laparoscopic partial nephrectomy. He is now proposed for a laparoscopic left heminephrectomy. Along with conventional imaging, a real-size 3D-printed renal model was used to plan de surgical approach. The perioperative experience of the surgical team was recorded. Results: The surgical team found the patient-specific 3D printed model useful for a better understanding of the anatomy and an easier surgical planning. Conclusion: The use of patient-specific 3D-printed renal models seem to be helpful for the surgical planning in complex renal tumors.

Maximizing the information obtained from chamber-based greenhouse gas exchange measurements in remote areas.

Measurements of greenhouse gas (GHG) fluxes, particularly methane (CH4) and nitrous oxide (N2O) in mountain ecosystems are scarce due to the complexity and unpredictable behavior of these gases, in addition to the remoteness of these ecosystems. In this context, we measured CO2, CH4, and N2O fluxes in four semi-natural pastures in the Pyrenees to investigate their magnitude and range of variability. Our interest was to study GHG phenomena at the patch-level, therefore we chose to measure the gas-exchange using a combination of a gas analyzer and manual chambers. The analyzer used is a photoacoustic field gas-monitor that allows multi-gas instantaneous measurements. After implementing quality control and corrections, data was of variable quality. We tackled this by categorizing data as to providing quantitative or only qualitative information: •50% and 59% of all CH4 and N2O data, respectively, provided quantitative information above the detection limit.•We chose not to discard data providing only qualitative information, because they identify highest- and lowest-flux peak periods and indicate the variability of the fluxes, along different altitudes and under different climatic conditions.•We chose not to give fluxes below detection limit a quantitative value but to acknowledge them as values identifying periods with low fluxes.

Weed suppression greatly increased by plant diversity in intensively managed grasslands: A continental-scale experiment.

Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment.At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, "method of nitrogen acquisition" and "pattern of temporal development".Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t  DM ha-1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity.Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%-75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture.Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77). Synthesis and applications. Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were consistently strong across mixtures varying widely in species' proportions and over time. The level of weed biomass did not vary greatly across mixtures varying widely in proportions of sown species. These diversity benefits in intensively managed grasslands are relevant for the sustainable intensification of agriculture and, importantly, are achievable through practical farm-scale actions.

Diffuse Renal Cortical Hemorrhage in the Setting of Subcapsular Hematoma: Diagnosis and Treatment with Embolization.

PURPOSE: To describe radiologic findings, embolization technique, and clinical outcomes in patients with renal subcapsular hematoma and diffuse cortical hemorrhage. MATERIALS AND METHODS: Ten patients with renal subcapsular hematoma and diffuse cortical hemorrhage were reviewed. Nine of the 10 had undergone procedures (nephrostomy, n = 4; biopsy, n = 4; embolization of a cerebral aneurysm, n = 1) and 1 patient was receiving oral anticoagulation. Computed tomography (CT), angiography, and embolization of bleeding sites were performed in all patients. RESULTS: CT and angiography revealed subcapsular hematoma with diffuse cortical hemorrhage at the level of the interlobar and/or arcuate branches. Total embolization of intrarenal arterial branches was required in 3 patients. Partial embolization, which also resulted in permanent functional loss, was required in 4. The functional loss was likely caused by the embolization procedure and the underlying renal disease. In these 4 patients, renal failure was demonstrated by scintigraphy in 3 cases and based on the need to start chronic hemodialysis in 1 case. In the remaining three patients, embolization did not compromise renal function. CONCLUSIONS: Diffuse cortical hemorrhage unrelated to the site of puncture may be seen in some cases of subcapsular hematoma. The cause is likely the laceration of transcortical capsular arteries secondary to enlargement of the subcapsular hematoma. In the present case series, embolization achieved hemorrhage control, but loss of renal function was observed in patients with underlying renal disease.

Functional Trait Changes, Productivity Shifts and Vegetation Stability in Mountain Grasslands during a Short-Term Warming.

Plant functional traits underlie vegetation responses to environmental changes such as global warming, and consequently influence ecosystem processes. While most of the existing studies focus on the effect of warming only on species diversity and productivity, we further investigated (i) how the structure of community plant functional traits in temperate grasslands respond to experimental warming, and (ii) whether species and functional diversity contribute to a greater stability of grasslands, in terms of vegetation composition and productivity. Intact vegetation turves were extracted from temperate subalpine grassland (highland) in the Eastern Pyrenees and transplanted into a warm continental, experimental site in Lleida, in Western Catalonia (lowland). The impacts of simulated warming on plant production and diversity, functional trait structure, and vegetation compositional stability were assessed. We observed an increase in biomass and a reduction in species and functional diversity under short-term warming. The functional structure of the grassland communities changed significantly, in terms of functional diversity and community-weighted means (CWM) for several traits. Acquisitive and fast-growing species with higher SLA, early flowering, erect growth habit, and rhizomatous strategy became dominant in the lowland. Productivity was significantly positively related to species, and to a lower extent, functional diversity, but productivity and stability after warming were more dependent on trait composition (CWM) than on diversity. The turves with more acquisitive species before warming changed less in composition after warming. Results suggest that (i) the short-term warming can lead to the dominance of acquisitive fast growing species over conservative species, thus reducing species richness, and (ii) the functional traits structure in grassland communities had a greater influence on the productivity and stability of the community under short-term warming, compared to diversity effects. In summary, short-term climate warming can greatly alter vegetation functional structure and its relation to productivity.

Turnover of grassland roots in mountain ecosystems revealed by their radiocarbon signature: role of temperature and management.

Root turnover is an important carbon flux component in grassland ecosystems because it replenishes substantial parts of carbon lost from soil via heterotrophic respiration and leaching. Among the various methods to estimate root turnover, the root's radiocarbon signature has rarely been applied to grassland soils previously, although the value of this approach is known from studies in forest soils. In this paper, we utilize the root's radiocarbon signatures, at 25 plots, in mountain grasslands of the montane to alpine zone of Europe. We place the results in context of a global data base on root turnover and discuss driving factors. Root turnover rates were similar to those of a subsample of the global data, comprising a similar temperature range, but measured with different approaches, indicating that the radiocarbon method gives reliable, plausible and comparable results. Root turnover rates (0.06-1.0 y(-1)) scaled significantly and exponentially with mean annual temperatures. Root turnover rates indicated no trend with soil depth. The temperature sensitivity was significantly higher in mountain grassland, compared to the global data set, suggesting additional factors influencing root turnover. Information on management intensity from the 25 plots reveals that root turnover may be accelerated under intensive and moderate management compared to low intensity or semi-natural conditions. Because management intensity, in the studied ecosystems, co-varied with temperature, estimates on root turnover, based on mean annual temperature alone, may be biased. A greater recognition of management as a driver for root dynamics is warranted when effects of climatic change on belowground carbon dynamics are studied in mountain grasslands.

Nitrogen yield advantage from grass-legume mixtures is robust over a wide range of legume proportions and environmental conditions.

Current challenges to global food security require sustainable intensification of agriculture through initiatives that include more efficient use of nitrogen (N), increased protein self-sufficiency through homegrown crops, and reduced N losses to the environment. Such challenges were addressed in a continental-scale field experiment conducted over 3 years, in which the amount of total nitrogen yield (Ntot ) and the gain of N yield in mixtures as compared to grass monocultures (Ngainmix ) was quantified from four-species grass-legume stands with greatly varying legume proportions. Stands consisted of monocultures and mixtures of two N2 -fixing legumes and two nonfixing grasses. The amount of Ntot of mixtures was significantly greater (P ≤ 0.05) than that of grass monocultures at the majority of evaluated sites in all 3 years. Ntot and thus Ngainmix increased with increasing legume proportion up to one-third of legumes. With higher legume percentages, Ntot and Ngainmix did not continue to increase. Thus, across sites and years, mixtures with one-third proportion of legumes attained ~95% of the maximum Ntot acquired by any stand and had 57% higher Ntot than grass monocultures. Realized legume proportion in stands and the relative N gain in mixture (Ngainmix /Ntot in mixture) were most severely impaired by minimum site temperature (R = 0.70, P = 0.003 for legume proportion; R = 0.64, P = 0.010 for Ngainmix /Ntot in mixture). Nevertheless, the relative N gain in mixture was not correlated to site productivity (P = 0.500), suggesting that, within climatic restrictions, balanced grass-legume mixtures can benefit from comparable relative gains in N yield across largely differing productivity levels. We conclude that the use of grass-legume mixtures can substantially contribute to resource-efficient agricultural grassland systems over a wide range of productivity levels, implying important savings in N fertilizers and thus greenhouse gas emissions and a considerable potential for climate change mitigation.

Temperature sensitivity of soil respiration rates enhanced by microbial community response.

Soils store about four times as much carbon as plant biomass, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.

Kidneys from donors with incidental renal tumors: should they be considered acceptable option for transplantation?

BACKGROUND: The increase in the prevalence of end-stage renal disease in developed countries and the shortage of deceased donors has made it necessary to increase the graft pool by means of several strategies, such as live donation, non-heart-beating donors, and expanded criteria donors. Frequently, and because of the increasing acceptance of older donors, we find a higher percentage of incidental renal masses in these donors as a result of the inherent epidemiology of this disease. These kidneys can be considered suitable grafts after bench surgery to remove the tumor. METHODS: Retrospective analysis of donors with a diagnosis of incidental small renal mass before implantation and their corresponding recipients was performed between January 2007 and September 2012. All cases underwent an ex vivo tumorectomy with a preoperatory pathologic analysis. Recipients were followed up according to our standard renal tumor protocol. RESULTS: Eight donors with incidental renal mass were detected (four live and four deceased donors). The mean age was 47.8 years. Eleven transplantations were performed. Eight cases received the kidney after tumor exeresis, and three, the contralateral one. The recipient mean age was 53.8 years.The mean tumor diameter was 14.8 mm, with pathologic stages pT1a in seven cases and pT1b in one case (five clear cell renal carcinoma, two chromophobe type, and one lipoma). Surgical margins were negative. Mean follow-up was 32.34 months; none of the patients presented tumor recurrence, and all had correct renal function. CONCLUSIONS: Kidneys with small incidental tumors can be considered an option for kidney transplantation in selected patients.

Stable isotope views on ecosystem function: challenging or challenged?

Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Ubeda, 18-22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes.