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Background: Pediatric Post-COVID-Condition (PPCC) clinics treat children despite limited scientific substantiation. By exploring real-life management of children diagnosed with PPCC, the International Post-COVID-Condition in Children Collaboration (IP4C) aimed to provide guidance for future PPCC care., Methods: We performed a cross-sectional international, multicenter study on used PPCC definitions; the organization of PPCC care programs and patients characteristics. We compared aggregated data from PPCC cohorts and identified priorities to improve PPCC care., Results: Ten PPCC care programs and six COVID-19 follow-up research cohorts participated. Aggregated data from 584 PPCC patients was analyzed. The most common symptoms included fatigue (71%), headache (55%), concentration difficulties (53%), and brain fog (48%). Severe limitations in daily life were reported in 31% of patients. Most PPCC care programs organized in-person visits with multidisciplinary teams. Diagnostic testing for respiratory and cardiac morbidity was most frequently performed and seldom abnormal. Treatment was often limited to physical therapy and psychological support., Conclusions: We found substantial heterogeneity in both the diagnostics and management of PPCC, possibly explained by scarce scientific evidence and lack of standardized care. We present a list of components which future guidelines should address, and outline priorities concerning PPCC care pathways, research and international collaboration., Impact: Pediatric Post-COVID Condition (PPCC) Care programs have been initiated in many countries. Children with PPCC in different countries are affected by similar symptoms, limiting many to participate in daily life. There is substantial heterogeneity in diagnostic testing. Access to specific diagnostic tests is required to identify some long-term COVID-19 sequelae. Treatments provided were limited to physical therapy and psychological support. This study emphasizes the need for evidence-based diagnostics and treatment of PPCC. The International Post-COVID Collaboration for Children (IP4C) provides guidance for guideline development and introduces a framework of priorities for PPCC care and research, to improve PPCC outcomes., (© 2024. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Abstract: A comprehensive international consensus on the cytogenetic risk-group stratification of KMT2A-rearranged (KMT2A-r) pediatric acute myeloid leukemia (AML) is lacking. This retrospective (2005-2016) International Berlin-Frankfurt-Münster Study Group study on 1256 children with KMT2A-r AML aims to validate the prognostic value of established recurring KMT2A fusions and additional cytogenetic aberrations (ACAs) and to define additional, recurring KMT2A fusions and ACAs, evaluating their prognostic relevance. Compared with our previous study, 3 additional, recurring KMT2A-r groups were defined: Xq24/KMT2A::SEPT6, 1p32/KMT2A::EPS15, and 17q12/t(11;17)(q23;q12). Across 13 KMT2A-r groups, 5-year event-free survival probabilities varied significantly (21.8%-76.2%; P < .01). ACAs occurred in 46.8% of 1200 patients with complete karyotypes, correlating with inferior overall survival (56.8% vs 67.9%; P < .01). Multivariable analyses confirmed independent associations of 4q21/KMT2A::AFF1, 6q27/KMT2A::AFDN, 10p12/KMT2A::MLLT10, 10p11.2/KMT2A::ABI1, and 19p13.3/KMT2A::MLLT1 with adverse outcomes, but not those of 1q21/KMT2A::MLLT11 and trisomy 19 with favorable and adverse outcomes, respectively. Newly identified ACAs with independent adverse prognoses were monosomy 10, trisomies 1, 6, 16, and X, add(12p), and del(9q). Among patients with 9p22/KMT2A::MLLT3, the independent association of French-American-British-type M5 with favorable outcomes was confirmed, and those of trisomy 6 and measurable residual disease at end of induction with adverse outcomes were identified. We provide evidence to incorporate 5 adverse-risk KMT2A fusions into the cytogenetic risk-group stratification of KMT2A-r pediatric AML, to revise the favorable-risk classification of 1q21/KMT2A::MLLT11 to intermediate risk, and to refine the risk-stratification of 9p22/KMT2A::MLLT3 AML. Future studies should validate the associations between the newly identified ACAs and outcomes and unravel the underlying biological pathogenesis of KMT2A fusions and ACAs., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Purpose: A previous study by the International Berlin-Frankfurt-Münster Study Group (I-BFM-SG) on childhood KMT2A -rearranged ( KMT2A -r) AML demonstrated the prognostic value of the fusion partner. This I-BFM-SG study investigated the value of flow cytometry-based measurable residual disease (flow-MRD) and evaluated the benefit of allogeneic stem-cell transplantation (allo-SCT) in first complete remission (CR1) in this disease., Methods: A total of 1,130 children with KMT2A -r AML, diagnosed between January 2005 and December 2016, were assigned to high-risk (n = 402; 35.6%) or non-high-risk (n = 728; 64.4%) fusion partner-based groups. Flow-MRD levels at both end of induction 1 (EOI1) and 2 (EOI2) were available for 456 patients and were considered negative (<0.1%) or positive (≥0.1%). End points were 5-year event-free survival (EFS), cumulative incidence of relapse (CIR), and overall survival (OS)., Results: The high-risk group had inferior EFS (30.3% high risk v 54.0% non-high risk; P < .0001), CIR (59.7% v 35.2%; P < .0001), and OS (49.2% v 70.5%; P < .0001). EOI2 MRD negativity was associated with superior EFS (n = 413; 47.6% MRD negativity v n = 43; 16.3% MRD positivity; P < .0001) and OS (n = 413; 66.0% v n = 43; 27.9%; P < .0001), and showed a trend toward lower CIR (n = 392; 46.1% v n = 26; 65.4%; P = .016). Similar results were obtained for patients with EOI2 MRD negativity within both risk groups, except that within the non-high-risk group, CIR was comparable with that of patients with EOI2 MRD positivity. Allo-SCT in CR1 only reduced CIR (hazard ratio, 0.5 [95% CI, 0.4 to 0.8]; P = .00096) within the high-risk group but did not improve OS. In multivariable analyses, EOI2 MRD positivity and high-risk group were independently associated with inferior EFS, CIR, and OS., Conclusion: EOI2 flow-MRD is an independent prognostic factor and should be included as risk stratification factor in childhood KMT2A -r AML. Treatment approaches other than allo-SCT in CR1 are needed to improve prognosis.

Hypodiploidy, defined as modal numbers (MNs) 45 or lower, has not been independently investigated in pediatric acute myeloid leukemia (AML) but is a well-described high-risk factor in pediatric acute lymphoblastic leukemia. We aimed to characterize and study the prognostic impact of hypodiploidy in pediatric AML. In this retrospective cohort study, we included children below 18 years of age with de novo AML and a hypodiploid karyotype diagnosed from 2000 to 2015 in 14 childhood AML groups from the International Berlin-Frankfurt-Münster (I-BFM) framework. Exclusion criteria comprised constitutional hypodiploidy, monosomy 7, composite karyotype, and t(8;21) with concurring sex chromosome loss. Hypodiploidy occurred in 81 patients (1.3%) with MNs, 45 (n = 66); 44 (n = 10) and 43 (n = 5). The most frequently lost chromosomes were chromosome 9 and sex chromosomes. Five-year event-free survival (EFS) and overall survival (OS) were 34% and 52%, respectively, for the hypodiploid cohort. Children with MN≤44 (n = 15) had inferior EFS (21%) and OS (33%) compared with children with MN = 45 (n = 66; EFS, 37%; OS, 56%). Adjusted hazard ratios (HRs) were 4.9 (P = .001) and 6.1 (P = .003). Monosomal karyotype or monosomy 9 had particular poor OS (43% and 15%, respectively). Allogeneic stem cell transplantation (SCT) in first complete remission (CR1) (n = 18) did not mitigate the unfavorable outcome of hypodiploidy (adjusted HR for OS was 1.5; P = .42). We identified pediatric hypodiploid AML as a rare subgroup with an inferior prognosis even in the patients treated with SCT in CR1., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Acute SARS-CoV-2 infections in children and adolescents are usually mild. However, they can suffer from ongoing symptoms, generally referred to as long COVID. Sleep disorders are one of the most frequent complaints in long COVID although precise data are missing. We assessed the sleep behavior of children and adolescents who presented at our outpatient clinic between January 2021 and May 2022 with the Children's Sleep Habits Questionnaire (CSHQ-DE). We compared the sleep behavior at three different time points: pre-COVID-19; post-COVID-19 at the initial presentation; and post-COVID-19 at re-presentation. Data from 45 patients were analyzed. Of those, 64% were female and the median age was 10 years (range: 0-18 years). Asymptomatic or mild COVID-19 disease was experienced in 89% of patients; 11% experienced moderate disease. The initial presentation occurred at a median of 20.4 weeks (6 weeks-14 months) after the infection. The CSHQ-DE score increased significantly from pre-COVID-19 (45.82 ± 8.7 points) to post-COVID-19 (49.40 ± 8.3 points; p ≤ 0.01). The score then normalized at re-presentation (46.98 ± 7.8; p = 0.1). The greatest changes were seen in the CSHQ-DE subscale score "daytime sleepiness". Our data showed that children and adolescents with long COVID often suffer from sleep disturbances. For most children and adolescents, these sleep disorders decreased over time without any further medical intervention aside from a basic sleep consultation.

Background: In Germany, the first case of coronavirus disease 2019 (COVID-19) was registered on 28 January 2020. By February 2021, the third wave of the pandemic began. So far, only few data are available on the SARS-CoV-2 prevalence and the clinical impact of an infection in patients with cystic fibrosis (CF)., Methods: From February 2020 until March 2021, we screened 156 CF patients for anti-SARS-CoV-2 IgG antibodies (serology) and the presence of SARS-CoV-2 in deep throat saliva or nasopharyngeal swabs (molecular testing). From patients with confirmed SARS-CoV-2 infection, we recorded symptoms and collected clinical data., Results: In total, 13 patients (8.3%) were tested positive for SARS-CoV-2 infection, most of them during the second and the beginning third wave of the pandemic. Ten positive tested patients described symptoms linked to COVID-19. The most common symptom was cough followed by fatigue and headache. SARS-CoV-2 infection did not impair lung function. No positive tested patient needed to be hospitalized., Conclusions: SARS-CoV-2 infections in patients with CF are not as rare as initially anticipated, as frequent testing revealed. However, infected patients did not experience more severe clinical courses or worse clinical outcome. Our observation is in line with published reports indicating that individuals with CF are not at higher risk for severe COVID-19., (© 2022. The Author(s).)

Amphiphilic copolymers that directly extract membrane proteins and lipids from cellular membranes to form nanodiscs combine the advantages of harsher membrane mimics with those of a native-like membrane environment. Among the few commercial polymers that are capable of forming nanodiscs, alternating diisobutylene/maleic acid (DIBMA) copolymers have gained considerable popularity as gentle and UV-transparent alternatives to aromatic polymers. However, their moderate hydrophobicities and high electric charge densities render all existing aliphatic copolymers rather inefficient under near-physiological conditions. Here, we introduce Glyco-DIBMA, a bioinspired glycopolymer that possesses increased hydrophobicity and reduced charge density but nevertheless retains excellent solubility in aqueous solutions. Glyco-DIBMA outperforms established aliphatic copolymers in that it solubilizes lipid vesicles of various compositions much more efficiently, thereby furnishing smaller, more narrowly distributed nanodiscs that preserve a bilayer architecture and exhibit rapid lipid exchange. We demonstrate the superior performance of Glyco-DIBMA in preparative and analytical applications by extracting a broad range of integral membrane proteins from cellular membranes and further by purifying a membrane-embedded voltage-gated K + channel, which was fluorescently labeled and analyzed with the aid of microfluidic diffusional sizing (MDS) directly within native-like lipid-bilayer nanodiscs.

Certain amphiphilic copolymers form lipid-bilayer nanodiscs from artificial and natural membranes, thereby rendering incorporated membrane proteins optimal for structural analysis. Recent studies have shown that the amphiphilicity of a copolymer strongly determines its solubilization efficiency. This is especially true for highly negatively charged membranes, which experience pronounced Coulombic repulsion with polyanionic polymers. Here, we present a systematic study on the solubilization of artificial multicomponent lipid vesicles that mimic inner mitochondrial membranes, which harbor essential membrane-protein complexes. In particular, we compared the lipid-solubilization efficiencies of established anionic with less densely charged or zwitterionic and even cationic copolymers in low- and high-salt concentrations. The nanodiscs formed under these conditions were characterized by dynamic light scattering and negative-stain electron microscopy, pointing to a bimodal distribution of nanodisc diameters with a considerable fraction of nanodiscs engaging in side-by-side interactions through their polymer rims. Overall, our results show that some recent, zwitterionic copolymers are best suited to solubilize negatively charged membranes at high ionic strengths even at low polymer/lipid ratios., (Copyright © 2021. Published by Elsevier B.V.)

Children with Down syndrome are at a high risk of developing transient abnormal myelopoiesis (TAM; synonym: TMD) or myeloid leukemia (ML-DS). While most patients with TAM are asymptomatic and go into spontaneous remission without a need for therapy, around 20% of patients die within the first six months due to TAM-related complications. Another 20-30% of patients progress from TAM to ML-DS. ML-DS patients are particularly vulnerable to therapy-associated toxicity, but the prognosis of relapsed ML-DS is extremely poor - thus, ML-DS therapy schemata must strive for a balance between appropriate efficacy (to avoid relapses) and treatment-related toxicity. This guideline presents diagnostic and therapeutic strategies for TAM and ML-DS based on the experience and results of previous clinical studies from the BFM working group, which have helped reduce the risk of early death in symptomatic TAM patients using low-dose cytarabine, and which have achieved excellent cure rates for ML-DS using intensity-reduced treatment protocols., Competing Interests: D. Reinhardt has advisory roles for Celgene Corporation, Novartis, Bluebird Bio, Janssen, and receives research funding from CLS Behring and Roche. J.-H. Klusmann has advisory roles for Bluebird Bio, Novartis, Roche and Jazz Pharmaceuticals., (Thieme. All rights reserved.)

The international pediatric oncology community has a long history of research collaboration. In the United States, the 2019 launch of the Children's Cancer Data Initiative puts the focus on developing a rich and robust data ecosystem for pediatric oncology. In this spirit, we present here our experience in constructing the Pediatric Cancer Data Commons (PCDC) to highlight the significance of this effort in fighting pediatric cancer and improving outcomes and to provide essential information to those creating resources in other disease areas. The University of Chicago's PCDC team has worked with the international research community since 2015 to build data commons for children's cancers. We identified six critical features of successful data commons design and implementation: (1) establish the need for a data commons, (2) develop and deploy the technical infrastructure, (3) establish and implement governance, (4) make the data commons platform easy and intuitive for researchers, (5) socialize the data commons and create working knowledge and expertise in the research community, and (6) plan for longevity and sustainability. Data commons are critical to conducting research on large patient cohorts that will ultimately lead to improved outcomes for children with cancer. There is value in connecting high-quality clinical and phenotype data to external sources of data such as genomic, proteomics, and imaging data. Next steps for the PCDC include creating an informed and invested data-sharing culture, developing sustainable methods of data collection and sharing, standardizing genetic biomarker reporting, incorporating radiologic and molecular analysis data, and building models for electronic patient consent. The methods and processes described here can be extended to any clinical area and provide a blueprint for others wishing to develop similar resources., Competing Interests: Suzi BirzConsulting or Advisory Role: Litmus Health Stefanie Hecker-NoltingResearch Funding: Eisai Nathalie GasparConsulting or Advisory Role: Eisai, IpsenTravel, Accommodations, Expenses: Eisai Gianni BisognoConsulting or Advisory Role: Bayer, Roche, iQone healthcareTravel, Accommodations, Expenses: Jazz Pharmaceuticals Dirk ReinhardtConsulting or Advisory Role: Novartis, Bluebird Bio, Hexal, BMS, Jazz Pharmaceuticals, JanssenResearch Funding: Celgene, Roche/Genentech, Novartis, BluebirBioTravel, Accommodations, Expenses: Jazz Pharmaceuticals C. Michel ZwaanConsulting or Advisory Role: Takeda, incyte, Sanofi, Bayer, NovartisResearch Funding: Pfizer, Jazz Pharmaceuticals, Celgene, TakedaTravel, Accommodations, Expenses: Jazz Pharmaceuticals Lindsay FrazierStock and Other Ownership Interests: Decibel TherapeuticsConsulting or Advisory Role: Decibel Therapeutics Katherine JanewayHonoraria: Foundation MedicineConsulting or Advisory Role: Bayer, IpsenTravel, Accommodations, Expenses: Bayer Doug HawkinsResearch Funding: Loxo, Bristol Myers Squibb, Merck Sharp & Dohme, Bayer, Lilly, Eisai, Amgen, Incyte, Jazz Pharmaceuticals, PfizerTravel, Accommodations, Expenses: Bayer, AstraZeneca E. Anders KolbTravel, Accommodations, Expenses: Roche/Genentech Susan CohnStock and Other Ownership Interests: Merck, Stryker (I), Amgen (I), Pfizer (I), AbbVie, Amgen, Lilly, Sanofi, Accelerated Medical Diagnostics, Novo Nordisk, Gilead Sciences, United Health Group, TevaHonoraria: Y-mAbs TherapeuticsResearch Funding: United Therapeutics, Merck Andrew D. J. PearsonConsulting or Advisory Role: Lilly, Takeda, Merck, CelgeneTravel, Accommodations, Expenses: Lilly, Takeda, Merck, Celgene Samuel VolchenboumStock and Other Ownership Interests: Litmus HealthConsulting or Advisory Role: AccordantTravel, Accommodations, Expenses: Sanford HealthNo other potential conflicts of interest were reported.

The co-occurrence of an inversion inv(3)(q21q26)/GATA2-MECOM and a Philadelphia translocation t(9;22)(q34;q11)/BCR-ABL1 in the context of chronic myeloid leukemia (CML) in blast crisis or acute myeloid leukemia (AML) has only rarely been described. To our knowledge, this co-occurrence has been reported in six pediatric patients with CML but not in pediatric patients with AML. Here, we report on a 7-year-old girl, who, presented with a t(9;22) and inv(3) in 14 of 15 metaphases and an additional monosomy 7 was detected in 5 of these metaphases (ISCN: 46,​XX,​inv(3)(q21q26),​t(9;22)(q34q11)[9]/45,​idem,​-7[5]/46,​XX[1]). The p190 BCR-ABL1 fusion transcript was detected by multiplex PCR and targeted RNA sequencing. Due to these results, a clear distinction between a CML in blast crisis and a BCR-ABL1 positive AML was not possible. The patient was treated according to the treatment recommendations of the AML-BFM study group and additionally received tyrosine kinase inhibitor therapy (Dasatinib). The treatment with Dasatinib was successful in eliminating the inv(3)/t(9;22) clone, but the ancestral inv(3) clone persisted. Based upon these findings we diagnosed an AML with inv(3) and a secondary acquisition of t(9;22). This treatment as well as an allogenic transplantation has led to a complete remission of the disease up to this date (21 months post diagnosis)., Competing Interests: Declaration of Competing Interest None, (Copyright © 2021. Published by Elsevier Inc.)

Post-relapse therapy remains critical for survival in children with acute myeloid leukemia (AML). We evaluated survival, response and prognostic variables following relapse in independent cooperative group studies conducted by COG and the population-based AML-BFM study group. BFM included 197 patients who relapsed after closure of the last I-BFM relapse trial until 2017, while COG included 852 patients who relapsed on the last Phase 3 trials (AAML0531, AAML1031). Overall survival at 5 years (OS) was 42 ± 4% (BFM) and 35 ± 2% (COG). Initial high-risk features (BFM 32 ± 6%, COG 26 ± 4%) and short time to relapse (BFM 29 ± 4%, COG 25 ± 2%) predicted diminished survival. In the BFM dataset, there was no difference in OS for patients who had a complete remission with full hematopoietic recovery (CR) following post-relapse re-induction compared to those with partial neutrophil and platelet recovery (CRp and CRi) only (52 ± 7% vs. 63 ± 10%, p = 0.39). Among 90 patients alive at last follow-up, 87 had received a post-relapse hematopoietic stem cell transplant (HSCT). OS for patients with post-relapse HSCT was 54 ± 4%. In conclusion, initial high-risk features and early relapse remain prognostic. Response assessment with full hematopoietic recovery following initial relapse therapy does not predict survival. These data indicate the need for post-relapse risk stratification in future studies of relapse therapies.

Successful management of relapse is critical to improve outcomes of children with acute myeloid leukemia (AML). We evaluated response, survival and prognostic factors after a second relapse of AML. Among 1222 pediatric patients of the population-based AML-Berlin-Frankfurt-Munster (BFM) study group (2004 until 2017), 73 patients met the quality parameters for inclusion in this study. Central review of source documentation warranted the accuracy of reported data. Treatment approaches included palliation in 17 patients (23%), intensive therapy with curative intent ( n = 46, 63%) and other regimens ( n = 10). Twenty-five patients (35%) received hematopoietic stem cell transplantation (HSCT), 21 of whom (88%) had a prior HSCT. Survival was poor, with a five-year probability of overall survival (pOS) of 15 ± 4% and 31 ± 9% following HSCT ( n = 25). Early second relapse (within one year after first relapse) was associated with dismal outcome (pOS 2 ± 2%, n = 44 vs. 33 ± 9%, n = 29; p < 0.0001). A third complete remission (CR) is required for survival: 31% ( n = 14) of patients with intensive treatment achieved a third CR with a pOS of 36 ± 13%, while 28 patients (62%) were non-responders (pOS 7 ± 5%). In conclusion, survival is poor but possible, particularly after a late second relapse and an intensive chemotherapy followed by HSCT. This analysis provides a baseline for future treatment planning.

Aims: Exposure to high levels of air pollution in industrialized urban areas is associated with an increased risk of heart failure (HF). On most days, the majority of European cities are only moderately affected by air pollution. The aim of this study was to evaluate the association between short-term exposure to moderate levels of air pollution with the risk of HF in a city with good air quality., Methods and Results: We recruited 576 patients (median age 82 years; 58.2% men) admitted to a large university hospital in Central Germany for HF to participate in a hospital-based, bidirectional, case-crossover study. Diagnosis of HF and symptom onset were verified individually. The effect of short-term exposure to nitrogen dioxide (NO 2 ), particulate matter (PM 10 ), and ozone (O 3 ) on the risk of HF was estimated using linear and non-linear (categorized) multivariate analyses for three different lag times (1, 2, and 3 days before HF onset). Air pollution variables were adjusted to the date of HF symptom onset. During the study period, the average daily concentration of air pollutants was only moderate and reflects the average European background air pollution. In particular, the concentration of air pollutants ranged from 2 to 63.39 μg/m 3 (median = 17.46 μg/m 3 ) for NO 2 , from 2 to 125.88 μg/m 3 (median = 44.61 μg/m 3 ) for O 3 , and from 2.21 to 166.79 μg/m 3 (median = 18.67 μg/m 3 ) for PM 10 . We did not find a linear or non-linear association between short-term exposure to NO 2 , O 3 , or PM 10 and risk for HF at all lag times in the overall population and subgroups., Conclusions: In an area with only moderate air pollution, short-term exposure to major air pollutants does not increase the risk for HF. Future studies should focus on a potential threshold effect of air pollution on HF risk as a basis for evidence-based development of statutory limits in highly polluted areas., (© 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Bone marrow fibrosis (BMF) is a rare complication in acute leukemia. In pediatrics, it predominantly occurs in acute megakaryoblastic leukemia (AMKL) and especially in patients with trisomy 21, called myeloid leukemia in Down syndrome (ML-DS). Defects in mesenchymal stromal cells (MSC) and cytokines specifically released by the myeloid blasts are thought to be the main drivers of fibrosis in the bone marrow niche (BMN). To model the BMN of pediatric patients with AMKL in mice, we first established MSCs from pediatric patients with AMKL ( n = 5) and ML-DS ( n = 9). Healthy donor control MSCs ( n = 6) were generated from unaffected children and adolescents ≤18 years of age. Steady-state analyses of the MSCs revealed that patient-derived MSCs exhibited decreased adipogenic differentiation potential and enrichment of proliferation-associated genes. Importantly, TGFB1 exposure in vitro promoted early profibrotic changes in all three MSC entities. To study BMF induction for longer periods of time, we created an in vivo humanized artificial BMN subcutaneously in immunodeficient NOD.Cg-Prkdc scid Il2rg tm1Wjl /SzJ mice, using a mixture of MSCs, human umbilical vein endothelial cell, and Matrigel. Injection of AMKL blasts as producers of TGFB1 into this BMN after 8 weeks induced fibrosis grade I/II in a dose-dependent fashion over a time period of 4 weeks. Thus, our study developed a humanized mouse model that will be instrumental to specifically examine leukemogenesis and therapeutic targets for AMKL blasts in future. IMPLICATIONS: TGFB1 supports fibrosis induction in a pediatric AMKL model generated with patient-derived MSCs. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/18/10/1603/F1.large.jpg., (©2020 American Association for Cancer Research.)

Aberrant activation of key signaling-molecules is a hallmark of acute myeloid leukemia (AML) and may have prognostic and therapeutic implications. AML summarizes several disease entities with a variety of genetic subtypes. A comprehensive model spanning from signal activation patterns in major genetic subtypes of pediatric AML (pedAML) to outcome prediction and pre-clinical response to signaling inhibitors has not yet been provided. We established a high-throughput flow-cytometry based method to assess activation of hallmark phospho-proteins (phospho-flow) in 166 bone-marrow derived pedAML samples under basal and cytokine stimulated conditions. We correlated levels of activated phospho-proteins at diagnosis with relapse incidence in intermediate (IR) and high risk (HR) subtypes. In parallel, we screened a set of signaling inhibitors for their efficacy against primary AML blasts in a flow-cytometry based ex vivo cytotoxicity assay and validated the results in a murine xenograft model. Certain phospho-signal patterns differ between genetic subtypes of pedAML. Some are consistently seen through all AML subtypes such as pSTAT5. In IR/HR subtypes high levels of GM-CSF stimulated pSTAT5 and low levels of unstimulated pJNK correlated with increased relapse risk overall. Combination of GM-CSF/pSTAT5 high and basal/pJNK low separated three risk groups among IR/HR subtypes. Out of 10 tested signaling inhibitors, midostaurin most effectively affected AML blasts and simultaneously blocked phosphorylation of multiple proteins, including STAT5. In a mouse xenograft model of KMT2A -rearranged pedAML, midostaurin significantly prolonged disease latency. Our study demonstrates the applicability of phospho-flow for relapse-risk assessment in pedAML, whereas functional phenotype-driven ex vivo testing of signaling inhibitors may allow individualized therapy., Competing Interests: DR has a consulting or advisory role for Celgene, Roche, Hexal, Medac, Boehringer, Behring and Novartis and received research support from Celgene Roche, Behring and Novartis. DR also received payments for travel, accommodation or other expenses from JAZZ Pharmaceuticals. KN received payments for travel, accommodation or other expenses from Affymetrix. MND received honoraria as well as payments for travel, accommodation or other expenses from Beckman-Coulter. For the remaining authors, no relevant conflicts of interest were declared., (Copyright © 2019 the Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Hematology Association.)

Acute myeloid leukemia is a life-threatening malignancy in children and adolescents treated predominantly by risk-adapted intensive chemotherapy that is partly supported by allogeneic stem cell transplantation. Mutations in the WT1 gene and NUP98-NSD1 fusion are predictors of poor survival outcome/prognosis that frequently occur in combination with internal tandem duplications of the juxta-membrane domain of FLT3 ( FLT3-ITD). To re-evaluate the effect of these factors in contemporary protocols, 353 patients (<18 years) treated in Germany with AML-BFM treatment protocols between 2004 and 2017 were included. Presence of mutated WT1 and FLT3-ITD in blasts (n=19) resulted in low 3-year event-free survival of 29% and overall survival of 33% compared to rates of 45-63% and 67-87% in patients with only one (only FLT3-ITD; n=33, only WT1 mutation; n=29) or none of these mutations (n=272). Including NUP98-NSD1 and high allelic ratio (AR) of FLT3-ITD (AR ≥0.4) in the analysis revealed very poor outcomes for patients with co-occurrence of all three factors or any of double combinations. All these patients (n=15) experienced events and the probability of overall survival was low (27%). We conclude that co-occurrence of WT1 mutation, NUP98-NSD1, and FLT3-ITD with an AR ≥0.4 as triple or double mutations still predicts dismal response to contemporary first- and second-line treatment for pediatric acute myeloid leukemia., Competing Interests: The authors declare no conflicts of interest regarding the current work. Dirk Reinhardt has consulting or advisory roles for Roche, Celgene, Hexal, Pfizer, Novartis, Boehringer and receives research funding from Celgene. Dirk Reinhardt received travel grants from Jazz Pharmaceuticals and Griffols. Naghmeh Niktoreh and Christine von Neuhoff received travel grants from Jazz Pharmaceuticals. The other authors have nothing to declare.

Despite intensified salvage treatments, children with relapsed/refractory acute myeloid leukemia (AML) have poor survival. We evaluated gemtuzumab ozogamicin (CD33-targeted drug) used on a compassionate basis in patients diagnosed from 1995 until 2014 within Acute Myeloid Leukemia Berlin-Frankfurt-Münster studies, and identified 76 patients (<18 years) with highly-advanced and pre-treated AML [refractory de novo acute myeloid leukemia (n=10), de novo AML refractory to relapse (1 st early: n=41; 1 st late: n=10; 2 nd or more: n=10), and secondary AML (n=5)]. At doses of 2.5-10 mg/m 2 , gemtuzumab ozogamicin was administered in 1-4 cycles as single agent (47%), combined with cytarabine (47%), or others (6%). Most common grade 3/4 adverse events were infections or febrile neutropenia (78% of severe adverse events), infusion-related immunological reactions (6%), and gastrointestinal symptoms (5%). Three patients experienced veno-occlusive disease (one fatal due to exacerbation of a pre-existing cardiomyopathy). Sixty-four percent received subsequent hematopoietic stem cell transplantation. Probability of 4-year overall survival was 18±5% in all, 27±7% in patients with and 0% in patients without hematopoietic stem cell transplantation ( P <0.0001). Administration of gemtuzumab ozogamicin on a patient-specific, compassionate use basis was frequently considered in our study group and proved to be effective for bridging children with very advanced AML to hematopoietic stem cell transplantation. Uniform prospective studies for these patients are urgently needed., (Copyright© 2019 Ferrata Storti Foundation.)

Aims High concentrations of air pollutants are associated with increased risk for myocardial infarction. The European Union has defined statutory limits for air pollutants based on upper absolute concentrations. We evaluated the association between rapid changes in air pollutants and the risk of myocardial infarction independently of absolute concentrations. Methods and results Using a hospital-based case-crossover study, effects of 24h changes of nitrogen oxides (NO X/2 ), particulate matter (PM 10 ), and ozone on the risk of myocardial infarction was assessed in 693 patients. In the overall population, increases of NO X of more than 20 µg/m 3 within 24 h were associated with an increase in the risk of myocardial infarction by up to 121% (odds ratio (OR) 2.21, 95% confidence interval (CI) 1.19-4.08). Comparably, rapid increases of NO 2 of more than 8 µg/m 3 tended to increase myocardial infarction risk by 73% (OR 1.73, 95% CI 0.91-3.28) while myocardial infarction risk decreased by 60% after a decrease of NO 2 concentration of more than 8 µg/m 3 (OR 0.4, 95% CI 0.21-0.77), suggesting a close-to-linear association. While results for ozone concentrations were ambiguous, rapid change in PM 10 was not associated with myocardial infarction risk. Conclusion Dynamics and extent of increase in nitrogen oxide concentrations may be an independent risk factor for myocardial infarction. As there are currently no European Union statutory limits reflecting this dynamic variation of air pollutants on a daily basis, the results urgently call for confirming studies in different geographical regions to verify the observations.

Overall survival (OS) of pediatric patients with acute myeloid leukemia (AML) increased in recent decades. However, it remained unknown whether advances in first-line treatment, supportive care, or second-line therapy mainly contributed to this improvement. Here, we retrospectively analyzed outcome and clinical data of 1940 pediatric AML patients (younger than 18 years of age), enrolled in the population-based AML-BFM trials between 1987 and 2012. While 5-year probability of OS (pOS) increased from 49 ± 3% (1987-1992) to 76 ± 4% (2010-2012; p < 0.0001), probability of event-free survival only improved from 41 ± 3% (1987-1992) to 50 ± 2% (1993-1998; p = 0.02) after introduction of high-dose cytarabine/mitoxantrone, but remained stable since then. Non-response and relapse rates stayed constant despite intensified first-line therapy (p = 0.08 and p = 0.17). Reduced fatal bleedings and leukostasis translated into fewer early deaths (8.1%vs. 2.2%; p = 0.001). Strikingly, pOS after non-response (13 ± 5% (1987-1992) vs. 43 ± 7% (2005-2010); p < 0.0001) or relapse (19 ± 4% vs. 45 ± 4%; p < 0.0001) improved. After 1999, more relapsed or refractory patients underwent hematopoietic stem cell transplantation (HSCT) with increased pOS after HSCT (29 ± 5% (1993-1998) vs. 50 ± 4% (2005-2010); p < 0.0001). Since efficacy of salvage therapy mainly contributed to better outcome in pediatric AML, our analysis indicates that a better allocation of patients, who cannot be cured with conventional chemotherapy, to an early "salvage-like" therapy is necessary.

The treatment of acute promyelocytic leukemia (APL) has changed significantly in recent years. Today, APL patients with standard risk (also known as low risk) can be treated chemotherapy-free only with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO). For high-risk patients, induction chemotherapy should be added. The curative results are good and comparable to those achieved in the past with chemotherapy plus ATRA. However, toxicities, especially infectious complications, are reduced. The main risk remains early lethal bleeding. Timely diagnosis and early ATRA treatment can reduce this risk. This review presents and discusses current treatment strategies and recommendations for APL in children., Competing Interests: U. C. war Mitglied des Advisory Boards von Teva Oncology. Die anderen Autoren geben an, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)

Survival in children with relapsed/refractory acute myeloid leukemia is unsatisfactory. Treatment consists of one course of fludarabine, cytarabine and liposomal daunorubicin, followed by fludarabine and cytarabine and stem-cell transplantation. Study ITCC 020/I-BFM 2009-02 aimed to identify the recommended phase II dose of clofarabine replacing fludarabine in the abovementioned combination regimen (3+3 design). Escalating dose levels of clofarabine (20-40 mg/m 2 /day × 5 days) and liposomal daunorubicin (40-80 mg/m 2 /day) were administered with cytarabine (2 g/m 2 /day × 5 days). Liposomal DNR was given on day 1, 3 and 5 only. The cohort at the recommended phase II dose was expanded to make a preliminary assessment of anti-leukemic activity. Thirty-four children were enrolled: refractory 1 st (n=11), early 1st (n=15), ≥2 nd relapse (n=8). Dose level 3 (30 mg/m 2 clofarabine; 60 mg/m 2 liposomal daunorubicin) appeared to be safe only in patients without subclinical fungal infections. Infectious complications were dose-limiting. The recommended phase II dose was 40 mg/m 2 clofarabine with 60 mg/m 2 liposomal daunorubicin. Side-effects mainly consisted of infections. The overall response rate was 68% in 31 response evaluable patients, and 80% at the recommended phase II dose (n=10); 22 patients proceeded to stem cell transplantation. The 2-year probability of event-free survival (pEFS) was 26.5±7.6 and probability of survival (pOS) 32.4±8.0%. In the 21 responding patients, the 2-year pEFS was 42.9±10.8 and pOS 47.6±10.9%. Clofarabine exposure in plasma was not significantly different from that in single-agent studies. In conclusion, clofarabine was well tolerated and showed high response rates in relapsed/refractory pediatric acute myeloid leukemia. Patients with (sub) clinical fungal infections should be treated with caution. Clofarabine has been taken forward in the Berlin-Frankfurt-Münster study for newly diagnosed acute myeloid leukemia. The Study ITCC-020 was registered as EUDRA-CT 2009-009457-13; Dutch Trial Registry number 1880., (Copyright© 2018 Ferrata Storti Foundation.)

Background: To evaluate if weather or changes in weather are risk factors for Bell's palsy (BP) as exposure to draught of cold air has been popularly associated with the occurrence of BP., Methods: Using a multicenter hospital-based case-crossover study, we analyzed the association between ambient temperature, atmospheric pressure, relative air humidity or their 24 h changes and the risk for BP in 825 patients or subgroups., Results: One day following a 24 h increase in atmospheric pressure of more than 6 hPa, the risk for BP increased by 35% (OR 1.35; 95% CI 1.03-1.78) in the overall population. The risk for BP more than doubled in patients with diabetes mellitus after rapid variations in ambient temperature, independent of the direction (temperature decrease > 2.25°C; OR 2.15; 95% CI 1.08-4.25; temperature increase between 0.75 and 2.25°C; OR 2.88; 95% CI 1.63-5.10)., Conclusions: Our findings support the hypothesis of an association between certain weather conditions and the risk for BP with acute changes in atmospheric pressure and ambient temperature as the main risk factors. Additionally, contrasting results for risk of BP after temperature changes in the diabetic and non-diabetic subgroups support the paradigm of a diabetic facial palsy as a distinct disease entity., (© 2018 S. Karger AG, Basel.)

We conducted a cytogenetic analysis of 642 children with de novo acute myeloid leukemia (AML) treated on the AML-Berlin-Frankfurt-Münster (BFM) 04 protocol to determine the prognostic value of specific chromosomal aberrations including monosomal (MK + ), complex (CK + ) and hypodiploid (HK + ) karyotypes, individually and in combination. Multivariate regression analysis identified in particular MK + (n=22) as a new independent risk factor for poor event-free survival (EFS 23±9% vs 53±2% for all other patients, P=0.0003), even after exclusion of four patients with monosomy 7 (EFS 28±11%, P=0.0081). CK + patients without MK had a better prognosis (n=47, EFS 47±8%, P=0.46) than those with MK + (n=12, EFS 25±13%, P=0.024). HK + (n=37, EFS 44±8% for total cohort, P=0.3) influenced outcome only when t(8;21) patients were excluded (remaining n=16, EFS 9±8%, P<0.0001). An extremely poor outcome was observed for MK + /HK + patients (n=10, EFS 10±10%, P<0.0001). Finally, isolated trisomy 8 was also associated with low EFS (n=16, EFS 25±11%, P=0.0091). In conclusion, monosomal karyotype is a strong and independent predictor for high-risk pediatric AML. In addition, isolated trisomy 8 and hypodiploidy without t(8;21) coincide with dismal outcome. These results have important implications for risk stratification and should be further validated in independent pediatric cohorts.

Objective: Most epileptic seizures occur unexpectedly and independently of known risk factors. We aimed to evaluate the clinical significance of patients' perception that weather is a risk factor for epileptic seizures., Methods: Using a hospital-based, bidirectional case-crossover study, 604 adult patients admitted to a large university hospital in Central Germany for an unprovoked epileptic seizure between 2003 and 2010 were recruited. The effect of atmospheric pressure, relative air humidity, and ambient temperature on the onset of epileptic seizures under temperate climate conditions was estimated., Results: We found a close-to-linear negative correlation between atmospheric pressure and seizure risk. For every 10.7 hPa lower atmospheric pressure, seizure risk increased in the entire study population by 14% (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.01-1.28). In patients with less severe epilepsy treated with one antiepileptic medication, seizure risk increased by 36% (1.36, 1.09-1.67). A high relative air humidity of >80% increased seizure risk in the entire study population by up to 48% (OR 1.48, 95% CI 1.11-1.96) 3 days after exposure in a J-shaped association. High ambient temperatures of >20°C decreased seizure risk by 46% in the overall study population (OR 0.54, 95% CI 0.32-0.90) and in subgroups, with the greatest effects observed in male patients (OR 0.33, 95% CI 0.14-0.74)., Significance: Low atmospheric pressure and high relative air humidity are associated with an increased risk for epileptic seizures, whereas high ambient temperatures seem to decrease seizure risk. Weather-dependent seizure risk may be accentuated in patients with less severe epilepsy. Our results require further replication across different climate regions and cohorts before reliable clinical recommendations can be made., (Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.)

Children with myeloid leukemia associated with Down syndrome (ML-DS) have superior outcome compared with non-DS patients, but suffer from higher constitutional cytotoxic drug susceptibility. We analyzed the outcome of 170 pediatric patients with ML-DS enrolled in the prospective, multicenter, open-label, nonrandomized ML-DS 2006 trial by Nordic Society for Pediatric Hematology and Oncology (NOPHO), Dutch Childhood Oncology Group (DCOG), and Acute Myeloid Leukemia-Berlin-Frankfurt-Münster (AML-BFM) study group. Compared with the historical control arm (reduced-intensity protocol for ML-DS patients from the AML-BFM 98 trial), treatment intensity was reduced by lowering the cumulative dose of etoposide (950 to 450 mg/m 2 ) and intrathecal central nervous system prophylaxis while omitting maintenance therapy. Still, 5-year overall survival (89% ± 3% vs 90% ± 4%; P log-rank = .64), event-free survival (EFS; 87% ± 3% vs 89% ± 4%; P log-rank = .71), and cumulative incidence of relapse/nonresponse (CIR/NR; 6% ± 3% vs 6% ± 2%; P Gray = .03) did not significantly differ between the ML-DS 2006 trial and the historical control arm. Poor early treatment response (5-year EFS, 58% ± 16% vs 88% ± 3%; P log rank = .0008) and gain of chromosome 8 (CIR/NR, 16% ± 7% vs 3% ± 2%, P Gray = .02; 5-year EFS, 73% ± 8% vs 91% ± 4%, P log rank = .018) were identified as independent prognostic factors predicting a worse EFS. Five of 7 relapsed patients (71%) with cytogenetic data had trisomy 8. Our study reveals prognostic markers for children with ML-DS and illustrates that reducing therapy did not impair excellent outcome. The trial was registered at EudraCT as #2007-006219-2., (© 2017 by The American Society of Hematology.)

Heritable predisposition is an important cause of cancer in children and adolescents. Although a large number of cancer predisposition genes and their associated syndromes and malignancies have already been described, it appears likely that there are more pediatric cancer patients in whom heritable cancer predisposition syndromes have yet to be recognized. In a consensus meeting in the beginning of 2016, we convened experts in Human Genetics and Pediatric Hematology/Oncology to review the available data, to categorize the large amount of information, and to develop recommendations regarding when a cancer predisposition syndrome should be suspected in a young oncology patient. This review summarizes the current knowledge of cancer predisposition syndromes in pediatric oncology and provides essential information on clinical situations in which a childhood cancer predisposition syndrome should be suspected., (© 2017 Wiley Periodicals, Inc.)

Background: To obtain better insight into the biology of acute myeloid leukemia (AML) in various age groups, this study focused on the genetic changes occurring during a lifetime., Methods: This study analyzed the relation between age and genetics from birth to 100 years in 5564 patients with de novo AML diagnosed from 1998 to 2012 (1192 patients from nationwide pediatric studies [AML Berlin-Frankfurt-Münster studies 98 and 2004] and 4372 adults registered with the Munich Leukemia Laboratory)., Results: The frequencies of cytogenetic subgroups were age-dependent. Favorable subtypes (t(8;21), inv(16)/t(16;16), and t(15;17)) decreased in general from the pediatric age group (2 to < 18 years; 33%) to the oldest groups (<5% for > 70 years; P < .0001). Unfavorable cytogenetics (-7/del(7), -5/del(5q) or 5p, inv(3)/t(3;3), t(6;9), complex karyotype, 12p, 17p, and 11q23/mixed-lineage leukemia aberrations, excluding t(9;11)) were frequent (42%) in infants (<2 years), had a low frequency in children and young adults (<22%), and increased in frequency up to 36% in patients older than 85 years (P = .01). This was even more significant for complex karyotypes (P ≤ .0001), which also showed a strong increase in the absolute age-specific incidence with age. Interestingly, the frequency of 11q23 abnormalities decreased from infants to older patients. The proportion of clinically relevant molecular aberrations of CCAAT/enhancer binding protein α, nucleophosmin (NPM1), and NPM1/fms-related tyrosine kinase 3-internal tandem duplication increased with age., Conclusions: Altogether, with the exclusion of infants, a significant decrease in the proportion of favorable cytogenetic subtypes and an increase in unfavorable cytogenetics were observed with increasing age. These findings indicate different mechanisms for the pathogenesis of AML; these different mechanisms also suggest directions for etiological research and contribute to the more unfavorable prognosis with increasing age. Cancer 2016;122:3821-3830. © 2016 American Cancer Society., (© 2016 American Cancer Society.)

Genetic abnormalities and early treatment response are the main prognostic factors in acute myeloid leukemia (AML). Acute megakaryoblastic leukemia (AMKL) is a rare subtype of AML. Deep sequencing has identified CBFA2T3/GLIS2 and NUP98/KDM5A as recurrent aberrations, occurring in similar frequencies as RBM15/MKL1 and KMT2A-rearrangements. We studied whether these cytogenetic aberrations can be used for risk group stratification. To assess frequencies and outcome parameters of recurrent cytogenetic aberrations in AMKL, samples and clinical data of patients treated by the Associazione Italiana Ematologia Oncologia Pediatrica, Berlin-Frankfurt-Munster Study Group, Children's Oncology Group, Dutch Childhood Oncology Group, and the Saint Louis Hôpital were collected, enabling us to screen 153 newly diagnosed pediatric AMKL cases for the aforementioned aberrations and to study their clinical characteristics and outcome. CBFA2T3/GLIS2 was identified in 16% of the cases; RBM15/MKL1, in 12%; NUP98/KDM5A and KMT2A rearrangements, in 9% each; and monosomy 7, in 6%. These aberrations were mutually exclusive. RBM15/MKL1-rearranged patients were significantly younger. No significant differences in sex and white blood cell count were found. NUP98/KDM5A, CBFA2T3/GLIS2, KMT2A-rearranged lesions and monosomy 7 (NCK-7) independently predicted a poor outcome, compared with RBM15/MKL1-rearranged patients and those with AMKL not carrying these molecular lesions. NCK-7-patients (n = 61) showed a 4-year probability of overall survival of 35 ± 6% vs 70 ± 5% in the RBM15/MKL1-other groups (n = 92, P < .0001) and 4-year probability of event-free survival of 33 ± 6% vs 62 ± 5% (P = .0013), the 4-year cumulative incidence of relapse being 42 ± 7% and 19 ± 4% (P = .003), respectively. We conclude that these genetic aberrations may be used for risk group stratification of pediatric AMKL and for treatment tailoring., (© 2016 by The American Society of Hematology.)

Despite recent advances in the treatment of children with acute megakaryoblastic leukemia (AMKL) using intensified treatment protocols, clear prognostic indicators, and treatment recommendations for this acute myeloid leukemia (AML) subgroup are yet to be defined. Here, we report the outcome of 97 pediatric patients with de novo AMKL (excluding Down syndrome [DS]) enrolled in the prospective multicenter studies AML-BFM 98 and AML-BFM 04 (1998-2014). AMKL occurred in 7.4 % of pediatric AML cases, at younger age (median 1.44 years) and with lower white blood cell count (mean 16.5 × 10(9)/L) as compared to other AML subgroups. With 60 ± 5 %, children with AMKL had a lower 5-year overall survival (5-year OS; vs. 68 ± 1 %, P log rank = 0.038). Yet, we achieved an improved 5-year OS in AML-BFM 04 compared to AML-BFM 98 (70 ± 6 % vs. 45 ± 8 %, P log rank = 0.041). Allogeneic hematopoietic stem cell transplantation in first remission did not provide a significant survival benefit (5-year OS 70 ± 11 % vs. 63 ± 6 %; P Mantel-Byar = 0.85). Cytogenetic data were available for n = 78 patients. AMKL patients with gain of chromosome 21 had a superior 5-year OS (80 ± 9 %, P log rank = 0.034), whereas translocation t(1;22)(p13;q13) was associated with an inferior 5-year event-free survival (38 ± 17 %, P log rank = 0.04). However, multivariate analysis showed that treatment response (bone marrow morphology on day 15 and 28) was the only independent prognostic marker (RR = 4.39; 95 % CI, 1.97-9.78). Interestingly, GATA1-mutations were detected in six patients (11 %) without previously known trisomy 21. Thus, AMKL (excluding DS) remains an AML subgroup with inferior outcome. Nevertheless, with intensive therapy regimens, a steep increase in the survival rates was achieved.

Introduction: Ureterovesical complications subsequent to renal transplantation are associated with a high morbidity leading to graft loss or even death. In the present study, the management of these complications by using interventional and surgical procedures (native pyeloureterostomy [NPUS]/ureteroureterostomy [NUU] vs ureteroneocystostomy [UNC]) was evaluated retrospectively., Patients and Methods: Between 1994 and 2012, a total of 780 kidney transplantations (690 deceased and 90 living donors) were performed at our institution. Demographic, clinical, and laboratory data from patients with urologic complications were analyzed and compared., Results: Fifty patients (6.4%) exhibited ureterovesical complications, and 18 patients (36%) were operated on immediately. In 32 (64%) of 50 patients, an interventional procedure was initially performed, with 21 patients (66%) undergoing operation due to therapy failure. NPUS/NUU and UNC were performed in 26 (66.6%) and 13 (33.3%) patients, respectively. Indications for an operation were ureteral stenosis in 12 patients (30.8%), ureteral necrosis and urine leakage in 19 patients (48.7%), and symptomatic vesicoureteral reflux in 8 patients (20.5%). Long-term results were comparable between all groups., Conclusions: Surgical revision of ureteral complications should be the standard therapy. NPUS/NUU, UNC, and the successful interventional procedures did not differ significantly in terms of long-term results., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Although regulation of stem cell homeostasis by microRNAs (miRNAs) is well studied, it is unclear how individual miRNAs genomically encoded within an organized polycistron can interact to induce an integrated phenotype. miR-99a/100, let-7, and miR-125b paralogs are encoded in two tricistrons on human chromosomes 11 and 21. They are highly expressed in hematopoietic stem cells (HSCs) and acute megakaryoblastic leukemia (AMKL), an aggressive form of leukemia with poor prognosis. Here, we show that miR-99a/100∼125b tricistrons are transcribed as a polycistronic message transactivated by the homeobox transcription factor HOXA10. Integrative analysis of global gene expression profiling, miRNA target prediction, and pathway architecture revealed that miR-99a/100, let-7, and miR-125b functionally converge at the combinatorial block of the transforming growth factor β (TGFβ) pathway by targeting four receptor subunits and two SMAD signaling transducers. In addition, down-regulation of tumor suppressor genes adenomatous polyposis coli (APC)/APC2 stabilizes active β-catenin and enhances Wnt signaling. By switching the balance between Wnt and TGFβ signaling, the concerted action of these tricistronic miRNAs promoted sustained expansion of murine and human HSCs in vitro or in vivo while favoring megakaryocytic differentiation. Hence, our study explains the high phylogenetic conservation of the miR-99a/100∼125b tricistrons controlling stem cell homeostasis, the deregulation of which contributes to the development of AMKL.

Reprogramming of somatic cells into patient-specific pluripotent analogues of human embryonic stem cells (ESCs) emerges as a prospective therapeutic angle in molecular medicine and a tool for basic stem cell biology. However, the combination of relative inefficiency and high variability of non-defined culture conditions precluded the use of this technique in a clinical setting and impeded comparability between laboratories. To overcome these obstacles, we sequentially devised a reprogramming protocol using one lentiviral-based polycistronic reprogramming construct, optimized for high co-expression of OCT4, SOX2, KLF4 and MYC in conjunction with small molecule inhibitors of non-permissive signaling cascades, such as transforming growth factor β (SB431542), MEK/ERK (PD0325901) and Rho-kinase signaling (Thiazovivin), in a defined extracellular environment. Based on human fetal liver fibroblasts we could efficiently derive induced pluripotent stem cells (iPSCs) within 14 days. We attained efficiencies of up to 10.97±1.71% resulting in 79.5- fold increase compared to non-defined reprogramming using four singular vectors. We show that the overall increase of efficiency and temporal kinetics is a combinatorial effect of improved lentiviral vector design, signaling inhibition and definition of extracellular matrix (Matrigel®) and culture medium (mTESR®1). Using this protocol, we could derive iPSCs from patient fibroblasts, which were impermissive to classical reprogramming efforts, and from a patient suffering from familial platelet disorder. Thus, our defined protocol for highly efficient reprogramming to generate patient-specific iPSCs, reflects a big step towards therapeutic and broad scientific application of iPSCs, even in previously unfeasible settings.

We present a model for diauxic growth of denitrifying bacteria in which nitrate reductase synthesis kinetics dominate the overall growth kinetics. The model is based on the assumption of the existence of a nitrate respiration operon, thereby linking the rate of nitrate uptake to the activity of nitrate reductase. We show that this approach can model diauxic growth of Pseudomonas denitrificans by conducting experiments in which nitrate reductase activity was measured during both lag and ensuing exponential growth phases. We consistently observed the pattern of low nitrate reductase enzyme activity during the lag phase, increasing before the onset of growth. By fitting model parameters we were able to successfully match experimental data for growth, nitrate uptake, and enzyme activity level., ((c) 2005 Wiley Periodicals, Inc.)

Methylmalonyl-CoA epimerase (MCE) from the hyperthermophilic archaeon, Pyrococcus horikoshii, was expressed at high levels in Escherichia coli, purified, and partially characterized. The P. horikoshii MCE enzyme was a homodimer with an apparent molecular mass of 31,700 Da. The K(m) of the enzyme for methylmalonyl-CoA was 79 microM and the k(cat) was 240 s(-1). The P. horikoshii enzyme was extremely heat-stable and withstood boiling for 60 min without detectable loss in activity.

A greater understanding of the tightly linked trophic groups of anaerobic and aerobic bacteria residing in municipal solid waste landfills will increase our ability to control methane emissions and pollutant fate in these environments. To this end, we characterized the composition of methanogenic and methanotrophic bacteria in samples taken from two regions of a municipal solid waste landfill that varied in age. A method combining polymerase chain reaction amplification, restriction fragment length polymorphism analysis and phylogenetic analysis was used for this purpose. 16S rDNA sequence analysis revealed a rich assemblage of methanogens in both samples, including acetoclasts, H2/CO2-users and formate-users in the newer samples and H2/CO2-users and formate-users in the older samples, with closely related genera including Methanoculleus, Methanofollis, Methanosaeta and Methanosarcina. Fewer phylotypes of type 1 methanotrophs were observed relative to type 2 methanotrophs. Most type 1 sequences clustered within a clade related to Methylobacter, whereas type 2 sequences were broadly distributed among clades associated with Methylocystis and Methylosinus species. This genetic characterization tool promises rapid screening of landfill samples for genotypes and, therefore, degradation potentials.

In this report, we identify the human DL-methylmalonyl-CoA racemase gene by analyzing prokaryotic gene arrangements and extrapolating the information obtained to human genes by homology searches. Sequence similarity searches were used to identify two groups of homologues that were frequently arranged with prokaryotic methylmalonyl-CoA mutase genes, and that were of unknown function. Both gene groups had homologues in the human genome. Because methylmalonyl-CoA mutases are involved in the metabolism of propionyl-CoA, we inferred that conserved neighbors of methylmalonyl-CoA mutase genes and their human homologues were also involved in this process. Subsequent biochemical studies confirmed this inference by showing that the prokaryotic gene PH0272 and its human homologue both encode DL-methylmalonyl-CoA racemases. To our knowledge this is the first report in which the function of a eukaryotic gene was determined based on the analysis of prokaryotic gene arrangements. Importantly, such analyses are rapid and may be generally applicable for the identification of human genes that lack homologues of known function or that have been misidentified on the basis of sequence similarity searches.

A central step in the biosynthesis of the modified folate methanopterin is the condensation of p-aminobenzoic acid (pAB) and 5-phospho-alpha-D-ribosyl-1-pyrophosphate (PRPP) which produce 4-(beta-D-ribofuranosyl)aminobenzene 5'-phosphate (beta-RFA-P) [White, R. H. (1996) Biochemistry 35, 3447-3456]. This reaction, catalyzed by the enzyme beta-RFA-P synthase, is unique among known phosphoribosyltransferases in that a decarboxylation of one of the substrates (pAB) occurs during the reaction and a C-riboside rather than an N-riboside is the product. In this work, the reaction catalyzed by the enzyme from Methanosarcina thermophila is shown to be analogous to other phosphoribosyltransferase reactions in that pyrophosphate is released as a product of the reaction, which is dependent upon magnesium ions. The molecular weight of the enzyme was estimated to be 65 000 using gel filtration chromatography, and the pH optimum was 4.8. Kinetic analysis indicated that the reaction involved a sequential pattern of substrate binding. Benzoic acid and several para-substituted benzoic acids inhibited beta-RFA-P synthase activity, while aniline, 4-aminobenzamide, and the methyl ester of pAB did not, indicating that an ionized carboxylic group plays a role in the binding of pAB. The observation that the enzyme was not inhibited by carbonyl reagents and that 4-hydroxybenzoic acid served as an alternate substrate, producing 4-(beta-D-ribofuranosyl)hydroxybenzene 5'-phosphate as the product, indicated that pyridoxal phosphate was not directly involved in the reaction mechanism. Incubation of the enzyme with PRPP and either pAB or 4-aminothiobenzoic acid in the presence of sodium cyanoborohydride led to the decreased production of beta-RFA-P and the accumulation of a reduced form of the proposed cyclohexadienimine reaction intermediates. These compounds were characterized by their acid-catalyzed decomposition which produces beta-D-ribofuranosylbenzene 5'-phosphate. On the basis of these results, a concerted mechanism is proposed for beta-RFA-P synthase in which an SN1-like reaction produces oxonium ion character at C-1 of PRPP which undergoes an ipso electrophilic aromatic substitution reaction at the carboxylic acid-bound carbon of pAB. Decarboxylation of the resulting cyclohexadienimine intermediate leads to the formation of beta-RFA-P.

Phosphotransacetylase catalyzes the following reaction: CoASH + CH3CO2PO3(2-) <==> CH3COSCoA + HPO4(2-) (where CoA is coenzyme A). Based on biochemical characterization of the enzyme from the obligate anaerobe Clostridium kluyveri, a ternary mechanism was proposed in which an unspecified cysteine abstracts a proton from CoASH forming a nucleophilic thiolate anion which attacks acetyl phosphate (J. Henkin and R. H. Abeles, Biochemistry 15:3472-3479, 1976). Heterologous production in Escherichia coli of the phosphotransacetylase from Methanosarcina thermophila, an obligately anaerobic methanoarchaeon, allowed site-specific replacements to identify essential residues. All four cysteines present in the sequence were individually replaced with alanine, and the kinetic constants of the altered enzymes were determined. The results indicated that only C159 is essential for activity; however, replacement with serine resulted in a fully active enzyme. Activity of the unaltered phosphotransacetylase was sensitive to N-ethylmaleimide. Inhibition kinetics of altered enzymes indicated that this sensitivity resulted from modification of C312, which is at the active site but itself is nonessential for catalysis. Five arginines were individually replaced with glutamine. Kinetic analysis of the altered enzymes identified R310 as essential for activity. Of the four nonessential for activity, R87 and R133 appear to be involved in binding CoA.

Nitrogenase catalyzes the reduction of N2, protons, and a number of alternative substrates that contain C-C, C-N, N-N, and N-O double and triple bonds. Recently it has been shown that nitrogenase also reduces the C==S bond of COS and the C==O bond of CO2. The current work demonstrates that the COS analogs SCN-, CS2, and OCNH are novel substrates for nitrogenase and that the reduction of these substrates produces changes in the electron paramagnetic resonance (EPR) spectrum of nitrogenase, providing insight into the mechanism of substrate reduction by nitrogenase. CH4, HCN, H2S, and NH4+ were detected as products of the nitrogenase-catalyzed reduction of SCN-. CS2 was reduced by nitrogenase to H2S, providing the first demonstration of CS2 reduction catalyzed by a purified enzyme. CO was detected as a product of KOCN reduction by nitrogenase. Interestingly, the Km for KOCN reduction to CO decreased at lower pH values, suggesting that OCNH rather than OCN- was the substrate for nitrogenase. Analysis of the EPR spectra of nitrogenase under turnover conditions in the presence of KOCN, CS2, or KSCN revealed new EPR signals. Signals with g-values corresponding to those reported for CO bound to the iron-molybdenum cofactor of nitrogenase were detected during turnover of nitrogenase in the presence of KOCN. During SCN- and CS2 reduction by nitrogenase, novel EPR inflections were observed that appear to report the interaction between nitrogenase and a bound substrate or a transient intermediate produced during the reduction of SCN- and CS2.

Nitrogenase is the metalloenzyme responsible for the biological reduction of N2 to NH3. Nitrogenase has been shown to reduce a variety of substrates in addition to N2 and protons. General properties of alternative substrates for nitrogenase are the presence of N-N, N-O, N-C, and C-C triple or double bonds. In the present work, we demonstrate that Azotobacter vinelandii nitrogenase can reduce both C-S and C-O bonds. Nitrogenase was found to reduce carbonyl sulfide (COS), to CO and H2S at a maximum rate of 37.2 +/- 2.0 nmol min-1 (mg of protein)-1 with a Km of 3.1 +/- 0.6 mM. The formation of CO from nitrogenase reduction of COS was monitored spectrophotometrically in real time by following the formation of carboxyhemoglobin. In this assay, the change in the visible absorption spectrum of reduced hemoglobin upon binding CO provided a sensitive way to quantify CO formation and to remove CO, which is a potent inhibitor of nitrogenase, from solution. COS reduction by nitrogenase required the molybdenum-iron protein (MoFeP), the iron protein (FeP), and MgATP. The reduction reaction was inhibited by MgADP, acetylene, and N2, while H2 was not an inhibitor of COS reduction. The pH optimum for COS reduction was 6.5. Nitrogenase was also found to reduce carbon dioxide (CO2) to CO and H2O. CO2 was reduced at a maximum rate of 0.8 +/- 0.07 nmole min-1 (mg of protein)-1 with a calculated Km for CO2 of 23.3 +/- 3.7 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

During the methanogenic fermentation of acetate by Methanosarcina thermophila, the CO dehydrogenase complex cleaves acetyl coenzyme A and oxidizes the carbonyl group (or CO) to CO2, followed by electron transfer to coenzyme M (CoM)-S-S-coenzyme B (CoB) and reduction of this heterodisulfide to HS-CoM and HS-CoB (A. P. Clements, R. H. White, and J. G. Ferry, Arch. Microbiol. 159:296-300, 1993). The majority of heterodisulfide reductase activity was present in the soluble protein fraction after French pressure cell lysis. A CO:CoM-S-S-CoB oxidoreductase system from acetate-grown cells was reconstituted with purified CO dehydrogenase enzyme complex, ferredoxin, membranes, and partially purified heterodisulfide reductase. Coenzyme F420 (F420) was not required, and CO:F420 oxidoreductase activity was not detected in cell extracts. The membranes contained cytochrome b that was reduced with CO and oxidized with CoM-S-S-CoB. The results suggest that a novel CoM-S-S-CoB reducing system operates during acetate conversion to CH4 and CO2. In this system, ferredoxin transfers electrons from the CO dehydrogenase complex to membrane-bound electron carriers, including cytochrome b, that are required for electron transfer to the heterodisulfide reductase. The cytochrome b was purified from solubilized membrane proteins in a complex with six other polypeptides. The cytochrome was not reduced when the complex was incubated with H2 or CO, and H2 uptake hydrogenase activity was not detected; however, the addition of CO dehydrogenase enzyme complex and ferredoxin enabled the CO-dependent reduction of cytochrome b.

Methanosarcina thermophila contains a multienzyme complex called the carbon-monoxide dehydrogenase complex, which has been resolved into a nickel/iron-sulfur and a corrinoid/iron-sulfur component. This complex plays a central role in acetoclastic methanogenesis. The Ni/Fe-S component catalyzes CO oxidation and has been proposed to be involved in cleavage of acetyl-CoA into its methyl, carbonyl, and CoA moieties. In the work reported here, three metal centers in the Ni/Fe-S component were characterized by electron paramagnetic resonance (EPR) spectroscopy and spectroelectrochemistry and pre-steady state kinetics. Center A contains nickel and iron and forms an EPR active adduct with CO, which is called the NiFeC species. The EPR spectrum of the NiFeC species has g values of 2.059, 2.051, and 2.029 and is observable at temperatures as high as 150 K. This signal had previously been observed only in the carbon-monoxide dehydrogenase complex of M. thermophila and the acetyl-CoA synthase from acetate-producing bacteria. Incubation of the CO-reduced Ni/Fe-S component with acetyl-CoA resulted in an increase in intensity of the NiFeC signal, which supports a role for the component in the cleavage of acetyl-CoA. Generation of the NiFeC EPR signal occurs with a rate constant of 0.4 s-1, a result that demonstrates the kinetic competence of this species in the acetyl-CoA cleavage reaction but rules it out as the site of oxidation of CO to CO2. Center B is likely to be a [4Fe-4S]2+/1+ center with g values of 2.04, 1.93, and 1.89 (gav = 1.95) and a standard reduction potential (E'0) of -444 mV. At potentials less than -500 mV, another EPR signal develops that appears to originate from another state of Center B. Center C is a fast relaxing center with g values of 2.02, 1.88, and 1.71 (gav = 1.87) and an E'0 of -154 mV.

Soluble extracts of the methanogenic archaeon, Methanosarcina thermophila TM-1, contained a divalent metal ion-stimulated protein-serine phosphatase activity. This activity was sensitive to micromolar concentrations of okadaic acid, microcystin-LR, or calyculin A, three compounds thought to be highly specific inhibitors of the type 1/2A/2B genetic superfamily of eukaryotic protein-serine/threonine phosphatases. The observation that each of these three chemically unrelated compounds inhibited this archaeal protein phosphatase activity suggests the existence of structural homology, and perhaps even common genetic ancestry, with the type 1/2A/2B superfamily of protein-serine/threonine phosphatases found in eukaryotic organisms.

The soil nitrifying bacterium Nitrosomonas europaea is capable of degrading trichloroethylene (TCE) and other halogenated hydrocarbons. TCE cometabolism by N. europaea resulted in an irreversible loss of TCE biodegradative capacity, ammonia-oxidizing activity, and ammonia-dependent O(2) uptake by the cells. Inactivation was not observed in the presence of allylthiourea, a specific inhibitor of the enzyme ammonia monooxygenase, or under anaerobic conditions, indicating that the TCE-mediated inactivation required ammonia monooxygenase activity. When N. europaea cells were incubated with [C]TCE under conditions which allowed turnover of ammonia monooxygenase, a number of cellular proteins were covalently labeled with C. Treatment of cells with allylthiourea or acetylene prior to incubation with [C]TCE prevented incorporation of C into proteins. The ammonia-oxidizing activity of cells inactivated in the presence of TCE could be recovered through a process requiring de novo protein synthesis. In addition to TCE, a series of chlorinated methanes, ethanes, and other ethylenes were screened as substrates for ammonia monooxygenase and for their ability to inactivate the ammonia-oxidizing system of N. europaea. The chlorocarbons could be divided into three classes depending on their biodegradability and inactivating potential: (i) compounds which were not biodegradable by N. europaea and which had no toxic effect on the cells; (ii) compounds which were cooxidized by N. europaea and had little or no toxic effect on the cells; and (iii) compounds which were cooxidized and produced a turnover-dependent inactivation of ammonia oxidation by N. europaea.

We have investigated the substrate specificity of ammonia monooxygenase in whole cells of the nitrifying bacterium Nitrosomonas europaea for a number of aliphatic halogenated hydrocarbons. To determine the effect of the halogen substituent and carbon chain length on substrate reactivity, we measured the rates of oxidation of the monohalogenated ethanes (fluoroethane, chloroethane, bromoethane, and iodoethane) and n-chlorinated C1 to C4 alkanes by whole cells of N. europaea. For monohalogenated ethanes, acetaldehyde was the major organic product and little or none of any of the alternate predicted products (2-halogenated alcohols) were detected. The maximum rate of haloethane oxidation increased with decreasing halogen molecular weight from iodoethane to chloroethane (19 to 221 nmol/min per mg of protein). In addition, the amount of substrate required for the highest rate of haloethane oxidation increased with decreasing halogen molecular weight. For the n-chlorinated alkanes, the rate of dechlorination, as measured by the appearance of the corresponding aldehyde product, was greatest for chloroethane and decreased dramatically for chloropropane and chlorobutane (118, 4, and 8 nmol of aldehyde formed per min per mg of protein, respectively). The concentration profiles for halocarbon oxidation by ammonia monooxygenase showed apparent substrate inhibition when ammonia was used as the reductant source. When hydrazine was used as the electron donor, no substrate inhibition was observed, suggesting that the inhibition resulted from reductant limitation.

Premature rupture (= PR) of the amnion is a serious complication even for the mature child if it occurs earlier than 24 hours before birth. To keep the interval as short as possible, the authors induce labour from week 35/0 in case of PR, provided the Bishop score is greater than 7. If the bishop score is lower, they conduct intracervical priming of the cervix with 0.4 mg PGE2 gel before induction of labour. This has proved clinically superior to intravenous procedures. In the study presented here, the authors attempted to find out whether intracervical administration of PGE2 gel would result in changes in the maternal and foetal plasma concentrations of oxytocin, PGFM, or PGEM when comparing conditions in case of ruptured amnion with those if the amnion remained intact. If the amnion is intact and the cervix immature (less than 2 cm), intracervical administration of 0.4 mg PGE2 gel produces a significant OT increase within 30 minutes. From a cervical width of 2 cm onwards, the OT levels are already primarily enhanced and will hardly change even after PGE2 gel administration. Similar conditions obtain in PR. PGFM plasma levels will rise only slightly within an hour after intracervical PGE2 gel administration, independent of whether there has been a rupture or not, or whether the cervix is dilated less than 2 cm or 2 cm and more.(ABSTRACT TRUNCATED AT 250 WORDS)