A phase I clinical, pharmacologic, and biologic study of thrombopoietin and granulocyte colony-stimulating factor in children receiving ifosfamide, carboplatin, and etoposide chemotherapy for recurrent or refractory solid tumors: a Children's Oncology Group experience.

PURPOSE: Ifosfamide, carboplatin, and etoposide (ICE) are associated with grade III/IV dose-limiting thrombocytopenia. The Children's Oncology Group conducted a phase I dose escalation, pharmacokinetic, and biological study of recombinant human thrombopoietin (rhTPO) after ICE in children with recurrent/refractory solid tumors (CCG-09717) to assess the toxicity and maximum tolerated dose of rhTPO administered at 1.2, 2.4, or 3.6 microg/kg per dose. EXPERIMENTAL DESIGN: Children received ifosfamide 1,800 mg/m2 on days 0 to 4, carboplatin 400 mg/m2 on days 0 to 1, and etoposide 100 mg/m2 on days 0 to 4. rhTPO was administered i.v. on days +4, +6, +8, +10, and +12 at 1.2, 2.4, or 3.6 microg/kg per dose.RESULTS: rhTPO was well tolerated and maximum tolerated dose was not reached. Median time to platelet recovery > or =100,000/microL of rhTPO at 1.2, 2.4, and 3.6 microg/kg/d was 24 days (22-24 d), 25 days (23-29 d), and 22 days (16-37 d), respectively. Patients required a median of 2 days of platelet transfusions (0-7 days). Mean (+/- SD) rhTPO maximum serum concentrations were 63.3 +/- 9.7 and 89.3 +/- 15.7 ng/mL and terminal half-lives were 47 +/- 13 and 64 +/- 42 hours after 2.4 and 3.6 microg/kg/d, respectively. There was a significant increase in colony-forming unit megakaryocyte upon WBC count recovery. CONCLUSIONS: rhTPO was well tolerated. Time to hematologic recovery and median number of platelet transfusions seem to be improved compared with historical controls receiving ICE + granulocyte colony-stimulating factor (CCG-0894).     

Executive function and general intellectual functioning in dyskinetic cerebral palsy: Comparison with spastic cerebral palsy and typically developing controls

AimTo comprehensively describe intellectual and executive functioning (EF) in people with dyskinetic cerebral palsy (DCP), by comparing their performance with that of: 1) age- and sex-matched typically developing controls (TDC); and 2) participants with spastic cerebral palsy (SCP) matched for age, sex, term/preterm and gross motor function classification system (GMFCS).MethodThis cross-sectional study was conducted by the University of Barcelona in collaboration with five institutions. Participants were people with DCP (n = 52; 24 females, median age 20.5 y: 5mo, interquartile range [IQR] = 13.75 y: 7mo; GMFCS I–V). As comparison groups, participants with SCP (n = 20; 10 females, median age = 20.5 y: 5.5mo, IQR = 13.75 y 9mo; GMFCS I–V) and TDC (n = 52; 24 females, median age = 20 y: 4mo, IQR = 12 y 7mo) were included. Intelligence and EF were assessed using common tests in all participants.ResultsBoth CP groups had lower intelligence than TDC and performed poorer in almost all EF tasks. Intelligence was higher in DCP than SCP (z = ?2.51, p = 0.01). Participants with DCP also performed significantly better in goal-setting tasks (z = 2.27, p = 0.03) and information processing (z = ?2.54, p = 0.01) than those with SCP.ConclusionPeople with DCP present lower general intellectual functioning and poorer EF across multiple domains than typically developing controls. People with DCP have higher general intellectual functioning and better EF than people with SCP when levels of motor severity are similar.     

Outcomes of First-Generation EGFR-TKIs Against Non-Small-Cell Lung Cancer Harboring Uncommon EGFR Mutations: A Post Hoc Analysis of the BE-POSITIVE Study

Background

Beyond progression after tyrosine kinase inhibitor in EGFR-positive non-small-cell lung cancer patients (BE-POSITIVE) was the first Italian multicenter observational study that reported the outcomes of first-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in a “real-life” Caucasian EGFR-mutated non-small-cell lung cancer (NSCLC) population. The sharing of multi-institutional experiences represents a crucial strategy to enrich knowledge about uncommon EGFR mutations. Therefore, we performed a post hoc analysis of the BE-POSITIVE study.

Origin recognition complex harbors an intrinsic nucleosome remodeling activity

Eukaryotic DNA replication is initiated at multiple chromosomal sites known as origins of replication that are specifically recognized by the origin recognition complex (ORC) containing multiple ATPase sites. In budding yeast, ORC binds to specific DNA sequences known as autonomously replicating sequences (ARSs) that are mostly nucleosome depleted. However, nucleosomes may still inhibit the licensing of some origins by occluding ORC binding and subsequent MCM helicase loading. Using purified proteins and single-molecule visualization, we find here that the ORC can eject histones from a nucleosome in an ATP-dependent manner. The ORC selectively evicts H2A-H2B dimers but leaves the (H3-H4)₂ tetramer on DNA. It also discriminates canonical H2A from the H2A.Z variant, evicting the former while retaining the latter. Finally, the bromo-adjacent homology (BAH) domain of the Orc1 subunit is essential for ORC-mediated histone eviction. These findings suggest that the ORC is a bona fide nucleosome remodeler that functions to create a local chromatin environment optimal for origin activity.

DNA replication is a vital life process for all cell types—bacterial, eukaryotic, and archaeal. While there are important differences among the replication proteins of the three domains of life, they mostly function in similar ways. All of them use an origin binding protein that acts with other factors to load two hexameric helicases onto DNA for bidirectional unwinding of the duplex, and thus the ability to simultaneously replicate both strands of the cellular genome (1–3). The eukaryotic origin binding protein is a heterohexamer referred to as the origin recognition complex (ORC) (4). The sequences of the Orc1-6 subunits are conserved from yeast to human, and several of the subunits contain an adenosine triphosphate (ATP)-binding AAA⁺ module as in the Escherichia coli DnaA initiator. Origins in the budding yeast Saccharomyces cerevisiae occur in 100- to 200-bp DNA regions known as autonomously replicating sequences (ARSs) (5–10). However, the existence of ARSs is limited to only some species of budding yeast. Origins of replication with defined DNA sequences are not known at this time to exist in other eukaryotes (1, 2).The special feature of a defined origin sequence in S. cerevisiae has facilitated extensive characterization of the mechanism of DNA replication initiation (1). ORC interacts with Cdc6, Cdt1, and the minichromosome maintenance protein complex (Mcm)2–7 heterohexamer to assemble a Mcm2-7 double hexamer (referred to here as MCM DH) onto DNA in G1 phase (1–3). The loaded MCM DH is the “licensing” factor for replication because it acts as the marker for origin firing in S phase (11). Specifically, the MCM DH is acted upon by several initiation factors to form 2 larger 11-subunit CMG (Cdc45/Mcm2-7/GINS) helicases (12, 13). The two CMG helicases are oriented toward and pass each other to unwind DNA, and recruit the replicative machinery to form bidirectional replication forks (14, 15). ORC and the many other factors required to license an origin and form bidirectional replication forks are conserved in all eukaryotes.The yeast ARS is AT rich, which is not favorable to nucleosome binding (16, 17). Indeed, chromatin immunoprecipitation sequencing (ChIP-seq) studies indicate that many ARSs have a nucleosome-free region (NFR) that expands in G1/S phase (10, 18–20). Presumably the nucleosomes are moved aside to make way for ORC-mediated MCM DH formation at origins in G1 phase, and for CMG formation in S phase. In vitro studies demonstrate that in the presence of saturating nucleosomes, the ARS is functional for replication initiation without need for classic nucleosome remodelers (21), indicating that the expansion of the NFR at an ARS site may be achieved intrinsically by the origin recognition and replication machinery.We have recently reported that ORC binding to nucleosomes facilitates the loading of MCM DHs onto DNA, regardless of the DNA sequence (22). In that study, we observed the loss of the fluorescently labeled histone signal after ORC–nucleosome interaction, but did not investigate further the source and mechanism of this observation as it was not the focus of the study. Considering that ORC binding is the first step of origin licensing and that ORC harbors multiple ATPase sites, here, we explored the possibility that ORC itself may possess an ATP-facilitated nucleosome remodeling activity. Using single-molecule fluorescence microscopy combined with optical trapping, we find that ORC is indeed an ATP-dependent nucleosome remodeler with the ability to eject H2A-H2B dimers. ORC-mediated nucleosome remodeling may represent the inaugural event toward creating a local chromatin environment permissive to replication initiation.     

Influence of Hydrogen Plasma on the Surface Structure of Beryllium

This paper presents the research results of hydrogen plasma effect on the surface structure of the TGP-56 beryllium. In the linear simulator, the operating conditions of the first wall of ITER are simulated. Beryllium was irradiated with hydrogen plasma at surface temperatures of ~360 °C, ~800 °C, and ~1200 °C, depending on its location in the ITER chamber; with a different number of pulses with a duration of each pulse of 500 s. Samples of irradiated beryllium were subjected to a set of material studies. Experimental data were obtained on the change in the structure of the surface and edges of the beryllium samples after the plasma effect. It was found that at normal (2 MW/m²) and increased (4.7 MW/m²) heat fluxes on the first wall of the ITER, the edges and beryllium surface have good resistance to erosion. Under critical conditions close to the melting point, beryllium strongly erodes and evaporates. It has been established that this material has a high resource resistance to hydrogen plasma effect in the ITER under operating conditions.     

SARS-CoV-2 Transmission in Belgian French-Speaking Primary Schools: An Epidemiological Pilot Study

Schools have been a point of attention during the pandemic, and their closure one of the mitigating measures taken. A better understanding of the dynamics of the transmission of SARS-CoV-2 in elementary education is essential to advise decisionmakers. We conducted an uncontrolled non-interventional prospective study in Belgian French-speaking schools to describe the role of attending asymptomatic children and school staff in the spread of COVID-19 and to estimate the transmission to others. Each participant from selected schools was tested for SARS-CoV-2 using a polymerase chain reaction (PCR) analysis on saliva sample, on a weekly basis, during six consecutive visits. In accordance with recommendations in force at the time, symptomatic individuals were excluded from school, but per the study protocol, being that participants were blinded to PCR results, asymptomatic participants were maintained at school. Among 11 selected schools, 932 pupils and 242 school staff were included between January and May 2021. Overall, 6449 saliva samples were collected, of which 44 came back positive. Most positive samples came from isolated cases. We observed that asymptomatic positive children remaining at school did not lead to increasing numbers of cases or clusters. However, we conducted our study during a period of low prevalence in Belgium. It would be interesting to conduct the same analysis during a high prevalence period.     

TAL1 cooperates with PI3K/AKT pathway activation in T-cell acute lymphoblastic leukemia

TAL1 is ectopically expressed in about 30% of T-cell acute lymphoblastic leukemia (T-ALL) due to chromosomal rearrangements leading to the STIL-TAL1 fusion genes or due to non-coding mutations leading to a de novo enhancer driving TAL1 expression. Analysis of sequence data from T-ALL cases demonstrates a significant association between TAL1 expression and activating mutations of the PI3K-AKT pathway. We investigated the oncogenic function of TAL1 and the possible cooperation with PI3K-AKT pathway activation using isogenic pro-T-cell cultures ex vivo and in vivo leukemia models. We found that TAL1 on its own suppressed T-cell growth, in part by affecting apoptosis genes, while the combination with AKT pathway activation reduced apoptosis and was strongly driving cell proliferation ex vivo and leukemia development in vivo. As a consequence, we found that TAL1+AKT^E17K transformed cells are more sensitive to PI3K-AKT pathway inhibition compared to AKT^E17K transformed cells, related to the negative effect of TAL1 in the absence of activated PI3K-AKT signaling. We also found that both TAL1 and PI3K-AKT signaling increased the DNA-repair signature in T cells resulting in synergy between PARP and PI3K-AKT pathway inhibition. In conclusion, we have developed a novel mouse model for TAL1+AKT^E17K driven T-ALL development and have identified a vulnerability of these leukemia cells to PI3K-AKT and PARP inhibitors.     

Severe and Rare Case of Human Dirofilaria repens Infection with Pleural and Subcutaneous Manifestations,Slovenia

We report a case of human Dirofilaria repens infection in a woman in Slovenia who had concomitant pleural and subcutaneous manifestations of the infection. This case report illustrates the clinical course of a severe symptomatic parasitic infection that had multisystemic manifestations.