ALBERT

Beschreibung: Megakaryoblastic leukemia 1 (MKL1) promotes the regulation of essential cell processes, including actin cytoskeletal dynamics, by coactivating serum response factor. Recently, the first human with MKL1 deficiency, leading to a novel primary immunodeficiency, was identified. We report a second family with 2 siblings with a homozygous frameshift mutation in MKL1. The index case died as an infant from progressive and severe pneumonia caused by Pseudomonas aeruginosa and poor wound healing. The younger sibling was preemptively transplanted shortly after birth. The immunodeficiency was marked by a pronounced actin polymerization defect and a strongly reduced motility and chemotactic response by MKL1-deficient neutrophils. In addition to the lack of MKL1, subsequent proteomic and transcriptomic analyses of patient neutrophils revealed actin and several actin-related proteins to be downregulated, confirming a role for MKL1 as a transcriptional coregulator. Degranulation was enhanced upon suboptimal neutrophil activation, whereas production of reactive oxygen species was normal. Neutrophil adhesion was intact but without proper spreading. The latter could explain the observed failure in firm adherence and transendothelial migration under flow conditions. No apparent defect in phagocytosis or bacterial killing was found. Also, monocyte-derived macrophages showed intact phagocytosis, and lymphocyte counts and proliferative capacity were normal. Nonhematopoietic primary fibroblasts demonstrated defective differentiation into myofibroblasts but normal migration and F-actin content, most likely as a result of compensatory mechanisms of MKL2, which is not expressed in neutrophils. Our findings extend current insight into the severe immune dysfunction in MKL1 deficiency, with cytoskeletal dysfunction and defective extravasation of neutrophils as the most prominent features.

Beschreibung: The development and application of chemistry transport models has a long tradition. Within the Netherlands the LOTOS–EUROS model has been developed by a consortium of institutes, after combining its independently developed predecessors in 2005. Recently, version 2.0 of the model was released as an open-source version. This paper presents the curriculum vitae of the model system, describing the model's history, model philosophy, basic features and a validation with EMEP stations for the new benchmark year 2012, and presents cases with the model's most recent and key developments. By setting the model developments in context and providing an outlook for directions for further development, the paper goes beyond the common model description.With an origin in ozone and sulfur modelling for the models LOTOS and EUROS, the application areas were gradually extended with persistent organic pollutants, reactive nitrogen, and primary and secondary particulate matter. After the combination of the models to LOTOS–EUROS in 2005, the model was further developed to include new source parametrizations (e.g. road resuspension, desert dust, wildfires), applied for operational smog forecasts in the Netherlands and Europe, and has been used for emission scenarios, source apportionment, and long-term hindcast and climate change scenarios. LOTOS–EUROS has been a front-runner in data assimilation of ground-based and satellite observations and has participated in many model intercomparison studies. The model is no longer confined to applications over Europe but is also applied to other regions of the world, e.g. China. The increasing interaction with emission experts has also contributed to the improvement of the model's performance. The philosophy for model development has always been to use knowledge that is state of the art and proven, to keep a good balance in the level of detail of process description and accuracy of input and output, and to keep a good record on the effect of model changes using benchmarking and validation. The performance of v2.0 with respect to EMEP observations is good, with spatial correlations around 0.8 or higher for concentrations and wet deposition. Temporal correlations are around 0.5 or higher. Recent innovative applications include source apportionment and data assimilation, particle number modelling, and energy transition scenarios including corresponding land use changes as well as Saharan dust forecasting. Future developments would enable more flexibility with respect to model horizontal and vertical resolution and further detailing of model input data. This includes the use of different sources of land use characterization (roughness length and vegetation), detailing of emissions in space and time, and efficient coupling to meteorology from different meteorological models.

Beschreibung: The development and application of chemistry transport models has a long tradition. Within the Netherlands the LOTOS-EUROS model has been developed by a consortium of institutes, after combination of its independently developed predecessors in 2005. Recently, version 2.0 of the model was released as an open source version. This paper presents the curriculum vitae of the model system, describing the model’s history, model philosophy, basic features, a validation with EMEP stations for the new benchmark year 2012, and presents cases with the model's most recent and key developments. By setting the model developments in context and providing an outlook for directions for further development, the paper goes beyond the common model description. With an origin in ozone and sulphur modelling for the models LOTOS and EUROS, the application areas were gradually extended with POPs, reactive nitrogen and primary and secondary particulate matter. After the combination of the models to LOTOS-EUROS in 2005, the model was further developed to include new source parametrizations (e.g. road resuspension, desert dust, wildfires), applied for operational smog forecasts in the Netherlands and Europe, and has been used for emission scenarios, source apportionment and long-term hindcast and climate change scenarios. LOTOS-EUROS has been a front-runner in data assimilation of ground-based and satellite observations and has participated in many model intercomparison studies. The model is no longer confined to applications over Europe but is also applied to other regions of the world, e.g. China. Also the increasing interaction with emission experts has contributed to the improvement of the model’s performance. The philosophy for model development has always been to use knowledge that is state of the art and proven, to keep good balance in the level of detail of process description and accuracy of input and output, and to keep a good track on the effect of model changes using benchmarking and validation. The performance of v2.0 with respect to EMEP observations is good, with spatial correlations around 0.8 or higher for concentrations and wet deposition. Temporal correlations are around 0.5 or higher. Recent innovative applications include source apportionment and data assimilation, particle number modelling, energy transition scenarios including corresponding land use changes as well as Saharan dust forecasting. Future developments would enable more flexibility with respect to model horizontal and vertical resolution and further detailing of model input data. This includes use of different sources of land use characterization (roughness length and vegetation), detailing of emissions in space and time, and efficient coupling to meteorology from different meteorological models.

Beschreibung: We evaluate modelled Greenland ice sheet (GrIS) near-surface climate, surface energy balance (SEB) and surface mass balance (SMB) from the updated regional climate model RACMO2 (1958–2016). The new model version, referred to as RACMO2.3p2, incorporates updated glacier outlines, topography and ice albedo fields. Parameters in the cloud scheme governing the conversion of cloud condensate into precipitation have been tuned to correct inland snowfall underestimation; snow properties are modified to reduce drifting snow and melt production in the ice sheet percolation zone. The ice albedo prescribed in the updated model is lower at the ice sheet margins, increasing ice melt locally. RACMO2.3p2 shows good agreement compared to in situ meteorological data and point SEB/SMB measurements, and better resolves SMB patterns than the previous model version, notably in the northeast, southeast, and along the K-transect in southwestern Greenland. This new model version provides updated, high-resolution gridded fields of the GrIS present-day climate and SMB, and will be used for future climate scenario projections in a forthcoming study.

Beschreibung: We evaluate modelled Greenland ice sheet (GrIS) near-surface climate, surface energy balance (SEB) and surface mass balance (SMB) from the updated regional climate model RACMO2 (1958–2016). The new model version, referred to as RACMO2.3p2, incorporates updated glacier outlines, topography and ice albedo fields. Parameters in the cloud scheme governing the conversion of cloud condensate into precipitation have been tuned to correct inland snowfall underestimation: snow properties are modified to reduce drifting snow and melt production in the ice sheet percolation zone. The ice albedo prescribed in the updated model is lower at the ice sheet margins, increasing ice melt locally. RACMO2.3p2 shows good agreement compared to in situ meteorological data and point SEB/SMB measurements, and better resolves the spatial patterns and temporal variability of SMB compared with the previous model version, notably in the north-east, south-east and along the K-transect in south-western Greenland. This new model version provides updated, high-resolution gridded fields of the GrIS present-day climate and SMB, and will be used for projections of the GrIS climate and SMB in response to a future climate scenario in a forthcoming study.

Beschreibung: Abstract 272 The response to therapy as determined by minimal residual disease (MRD) is currently used for stratification in treatment protocols for pediatric acute lymphoblastic leukemia (ALL). Even though MRD classification clearly identifies patients at low or at high risk for relapse, it also results in a large intermediate group (50 to 60% of patients), which still contains approximately half of all relapse cases. To improve risk stratification, we evaluated the added value of the IKZF1 alteration status, recently identified as a prognostic factor, in precursor-B-ALL patients. In an unbiased cohort of 131 uniformly treated precursor-B-ALL patients, we determined MRD levels at 42 and 84 days after treatment initiation using RQ-PCR analysis of Ig/TCR rearrangements. Based on these levels, patients were divided into three groups: MRD-Low (MRD-L), MRD-Medium (MRD-M) and MRD-High (MRD-H). IKZF1 alterations at diagnosis were determined using multiplex ligation-dependent probe amplification and genomic sequencing. We confirmed the strong prognostic significance of MRD classification, which was independent of IKZF1 status. Importantly, in the large MRD-M group (n=81; 62% of patients) containing 46% of the relapsed patients, IKZF1 alteration status identified 8 out of 11 relapsed patients (72%). The 9 year relapse-free survival (RFS) for IKZF1 mutated patients in this MRD-M group was 27% compared to 96% for patients wild-type for IKZF1 (P

Beschreibung: Purpose Vincristine (VCR) is frequently used for the treatment of pediatric cancer. However, it can lead to dose-limiting vincristine-induced peripheral neuropathy (VIPN). This study aimed to investigate if prolonging the duration of VCR administration (1-hour infusions instead of push injections) reduces VIPN in children with cancer during the first year of treatment. Methods The VINCA trial is an international multicenter randomized controlled trial. Participants were randomized to receive all VCR administrations through push injections or 1-hour infusions. Dose of VCR was 1.5-2 mg/m2 with a maximum of 2 mg. VIPN measurements were performed at baseline and 1-3 times during treatment, depending on the number of VCR administrations and the total treatment time, using 4 items of the common toxicity criteria of adverse events (CTCAE version 4.03): constipation, peripheral sensory neuropathy, peripheral motor neuropathy and neuralgia. Individual item scores range from zero (no complaints) to five (death). The primary outcome of this trial was total sum CTCAE score during first year of treatment. For the current analysis, patients treated for acute lymphoblastic leukemia (ALL) or Hodgkin's lymphoma were included. All included patients were analyzed according to the intention-to-treat principle. Besides VIPN measurements, data on all relevant co-medication during treatment were collected, including data of concurrent azole therapy (as azole treatment is known to interact with VCR treatment). Descriptive data were analyzed using either chi-square tests or t-tests. Longitudinal data were analyzed using repeated measures mixed model analysis for continuous outcomes (total CTCAE sum score) and generalized estimating equations for dichotomous outcomes (having VIPN yes or no, with VIPN defined as a CTCAE score of ≥ 2 on any of the 4 CTCAE items). Patients were considered to have been treated with concurrent azole therapy when azoles were used during the week before or following VCR administration and if ≥ 50% of VCR administrations between two succeeding measurements were given with concurrent azole therapy. Results were corrected for concurrent azole therapy, cumulative VCR dose, disease, age, gender, ethnicity and time since diagnosis. Results In total 90 children (n=45 one hour infusions group, n=45 push injections group) participated in the study, 58 (64%) with ALL and 18 (20%) with HL. Participants in the two randomization groups did not significantly differ regarding gender, age, ethnicity, diagnosis, or cumulative VCR dose. Overall results showed no effect of randomization on total CTCAE score (β=0.07, 95% confidence interval (CI) -0.42-0.56, p=0.78). However, concurrent azole treatment appeared to be an effect modifier in this analysis and therefore results are reported separately for measurements with (n=24) and without concurrent azole therapy (n=226). Among patients who received concurrent azole therapy, total CTCAE sum score was significantly higher in the push group compared to the 1-hour group (β=1.95, 95% CI 0.49-3.41, p=0.01), while among those without concurrent azole therapy, these CTCAE sum scores did not differ between the two randomization groups (β=-0.17, 95% CI: -0.67-0.34, p=0.52). The risk of developing VIPN (no/yes) did not significantly differ between both randomization groups, irrespective whether concurrent azole treatment was given or not (with azole: OR (95% CI)=4.92 (0.60-40.37), p=0.14; without azole: OR (95% CI)=0.97 (0.51-1.82, p=0.92). Conclusions Overall, administration method of VCR given as push injection or 1-hour infusion did not seem to affect the risk of developing VIPN in children treated for ALL or HL when using the current dosing regimen. However, when concurrent azole treatment is given, total CTCAE scores are significantly lower in children in the 1-hour infusion group compared to the push injection group, demonstrating less VIPN. These results indicate that for children treated with VCR and concurrent azole therapy for the prevention or treatment of fungal infections, administration of VCR by 1-hour infusions instead of push injections is recommended. Figure Disclosures Kaspers: Helsinn Healthcare: Consultancy; Boehringer Ingelheim Pharma: Other: Member of a DSMC. van der Sluis:medac: Consultancy; jazz farmaceuticals: Consultancy.