Circulating Transcript Analysis (NETest) in GEP-NETs Treated With Somatostatin Analogs Defines Therapy

Context: Early and precise delineation of therapeutic responses are key issues in neuroendocrine neoplasm/tumor management. Imaging is currently used but exhibits limitations in sensitivity and specificity. The utility of biomarkers is unclear. Objective, Setting, and Design: This prospective cohort study (11 mo) sought to determine whether measurements of circulating neuroendocrine tumor transcripts (NETest) predict responses to somatostatin analogs (SSAs). Patients: The test set consisted of 35 SSA-treated gastroenteropancreatic-NETs (RECISTevaluated). The prospective set consisted of 28 SSA-treated Grade 1–Grade 2 GEP-NETs. Intervention(s): Whole blood for transcript analysis (NETest) and plasma for Chromogranin A (CgA) (baseline), were collected every 4 weeks (prior to SSA injection). Morphologic (multidetector computed tomography/MRI) and functional imaging (99mTc-[HYNIC, Tyr3]-Octreotide) was undertaken at entry and 6-month intervals until progression (RECIST 1.0). Main Outcome Measure(s): Treatment response. Results: Test set: NETest (≥80%; scale, 0–100%) differentiated stable (SD) and progressive (PD) disease (P < .0001). Prospective set: 28 patients (26/28 SD) undergoing standard SSA. Grading: 12 G1, 16 G2. SSA Response: progression-free survival: 315 days: 14 (50%) SD, 14 (50%) PD. NETest: Twenty had elevated (≥80%) values; 14 developed PD; six, SD. CgA: Twelve of 28 exhibited elevated baseline values and/or subsequent >25% increase; eight developed PD; four, SD. NETest (P = .002) and grade (P = .054) were the only factors associated with treatment response. Multiple regression analysis established that the NETest could predict disease progression (P = .0002). NETest changes occurred significantly earlier (146 d prior to progression vs 56 d CgA; P < .0001; χ2 = 19) and in more patients (100 vs 57%; P < .02). Conclusions: NETest values (80–100%) were more accurate and occurred at a significantly earlier time point than CgA and predicted SSA treatment response

Interfacial and structural characteristics of polyelectrolyte multilayers used as cushions for supported lipid bilayers

The surface properties of polyelectrolyte multilayers (PEMs) obtained via sequential adsorption of oppositely charged polyions from their solutions and used as cushions for supported lipid bilayers were investigated.</p

The anterior visceral endoderm of the mouse embryo is established from both preimplantation precursor cells and by de novo gene expression after implantation

Initiation of the development of the anterior–posterior axis in the mouse embryo has been thought to take place only when the anterior visceral endoderm (AVE) emerges and starts its asymmetric migration. However, expression of Lefty1, a marker of the AVE, was recently found to initiate before embryo implantation. This finding has raised two important questions: are the cells that show such early, preimplantation expression of this AVE marker the real precursors of the AVE and, if so, how does this contribute to the establishment of the AVE? Here, we address both of these questions. First, we show that the expression of another AVE marker, Cer1, also commences before implantation and its expression becomes consolidated in the subset of ICM cells that comprise the primitive endoderm. Second, to determine whether the cells showing this early Cer1 expression are true precursors of the AVE, we set up conditions to trace these cells in time-lapse studies from early periimplantation stages until the AVE emerges and becomes asymmetrically displaced. We found that Cer1-expressing cells are asymmetrically located after implantation and, as the embryo grows, they become dispersed into two or three clusters. The expression of Cer1 in the proximal domain is progressively diminished, whilst it is reinforced in the distal–lateral domain. Our time-lapse studies demonstrate that this distal–lateral domain is incorporated into the AVE together with cells in which Cer1 expression begins only after implantation. Thus, the AVE is formed from both part of an ancestral population of Cerl-expressing cells and cells that acquire Cer1 expression later. Finally, we demonstrate that when the AVE shifts asymmetrically to establish the anterior pole, this occurs towards the region where the earlier postimplantation expression of Cer1 was strongest. Together, these results suggest that the orientation of the anterior–posterior axis is already anticipated before AVE migration

Persistent symptoms are associated with long term effects of COVID-19 among children and young people: Results from a systematic review and meta-analysis of controlled studies

BACKGROUND: Research on the long-term impact on COVID-19 in children and young people (CYP) has been published at pace. We aimed to update and refine an earlier systematic review and meta-analysis to assess the current evidence for Post-COVID-19 Condition in CYP. METHODS: Studies from the previous systematic review were combined with studies from a systematic search from July 2021 to November 2022 (registration PROSPERO CRD42021233153). Eligible studies included CYP aged ≤19 years with confirmed or probable SARS-CoV-2 infection and symptoms persisting at least 12 weeks. FINDINGS: 55 studies (n = 1,139,299 participants) were included. Over two-hundred symptoms were associated with Post COVID-19 Condition. Gastrointestinal problems, headaches, cough and fever were among the most prevalent symptoms with rates of 50.2%, 35.6%, 34.7% and 25.8% respectively. Twenty-one symptoms from 11 studies were suitable for meta-analysis. There were significantly higher pooled estimates of proportions of symptoms for altered / loss of smell or taste, dyspnoea, fatigue, and myalgia in CYP with confirmed SARS-CoV-2 infection. Heterogeneity was high suggesting substantial variation amongst the included studies. CONCLUSIONS: Many CYP continue to experience symptoms after SARS-CoV-2 infection. Efforts to aid early identification and intervention of those most in need is warranted and the consequences of COVID-19 for CYP call for long-term follow-up

Complex exon-intron marking by histone modifications is not determined solely by nucleosome distribution

It has recently been shown that nucleosome distribution, histone modifications and RNA polymerase II (Pol II) occupancy show preferential association with exons (“exon-intron marking”), linking chromatin structure and function to co-transcriptional splicing in a variety of eukaryotes. Previous ChIP-sequencing studies suggested that these marking patterns reflect the nucleosomal landscape. By analyzing ChIP-chip datasets across the human genome in three cell types, we have found that this marking system is far more complex than previously observed. We show here that a range of histone modifications and Pol II are preferentially associated with exons. However, there is noticeable cell-type specificity in the degree of exon marking by histone modifications and, surprisingly, this is also reflected in some histone modifications patterns showing biases towards introns. Exon-intron marking is laid down in the absence of transcription on silent genes, with some marking biases changing or becoming reversed for genes expressed at different levels. Furthermore, the relationship of this marking system with splicing is not simple, with only some histone modifications reflecting exon usage/inclusion, while others mirror patterns of exon exclusion. By examining nucleosomal distributions in all three cell types, we demonstrate that these histone modification patterns cannot solely be accounted for by differences in nucleosome levels between exons and introns. In addition, because of inherent differences between ChIP-chip array and ChIP-sequencing approaches, these platforms report different nucleosome distribution patterns across the human genome. Our findings confound existing views and point to active cellular mechanisms which dynamically regulate histone modification levels and account for exon-intron marking. We believe that these histone modification patterns provide links between chromatin accessibility, Pol II movement and co-transcriptional splicing

"People don't have the answers": A qualitative exploration of the experiences of young people with Long COVID

Young people living with Long COVID are learning to navigate life with a constellation of poorly understood symptoms. Most qualitative studies on experiences living with Long COVID focus on adult populations. This study aimed to understand the experiences of young people living with Long COVID. Qualitative, semi-structured interviews were conducted (n = 16); 11 young people (aged 13-19) and five parents were recruited from the Children and Young People with Long COVID (CLoCk) study (n = 11) or its patient and public involvement and engagement (PPIE) group (n = 5). Thematic analysis generated four themes: (i) Unravelling Long COVID: Exploring Symptom Journeys and Diagnostic Dilemmas; (ii) Identity Disruption and Adjustment; (iii) Long COVID's Ripple Effect: the impact on Mental Health, Connections, and Education; and (iv) Navigating Long COVID: barriers to support and accessing services. Treatment options were perceived as not widely available or ineffective, emphasising the need for viable and accessible interventions for young people living with Long COVID

Bacteria-responsive multilayer coatings comprising polycationic nanospheres for bacteria biofilm prevention on urinary catheters

This work reports on the development of infection-preventive coatings on silicone urinary catheters that contain in their structure and release on demand antibacterial polycationic nanospheres. Polycationic aminocellulose conjugate was first sonochemically processed into nanospheres to improve its antibacterial potential compared to the bulk conjugate in solution (ACSol). Afterwards the processed aminocellulose nanospheres (ACNSs) were combined with the hyaluronic acid (HA) polyanion to build a layer-by-layer construct on silicone surfaces. Although the coating deposition was more effective when HA was coupled with ACSol than with ACNSs, the ACNSs-based coatings were thicker and displayed smoother surfaces due to the embedment of intact nanospheres. The antibacterial effect of the ACNSs multilayers was by 40 % higher compared to the ACSol coatings. This fact was further translated into more effective prevention of Pseudomonas aeruginosa biofilm formation. The coatings were stable in absence of bacteria, whereas their disassembling occurred gradually during incubation with Pseudomonas aeruginosa, and thus eradicate the biofilm upon release of antibacterial agents. Only 5 bilayers of HA/ACNSs were sufficient to prevent the biofilm formation, in contrast to the 10 bilayers of ACSol required to achieve the same effect. The antibiofilm efficiency of (HA/ACNSs)10 multilayer construct built on a Foley catheter was additionally validated under dynamic conditions using a model of catheterized bladder in which the biofilm was grown during seven days.M.M.F. acknowledges the support of the European Commissionunder the Marie Curie Intra-European Fellowship (IEF) Program (Grant Agreement ‘‘NanoQuench” FP7-331416)

Noisy Splicing Drives mRNA Isoform Diversity in Human Cells

While the majority of multiexonic human genes show some evidence of alternative splicing, it is unclear what fraction of observed splice forms is functionally relevant. In this study, we examine the extent of alternative splicing in human cells using deep RNA sequencing and de novo identification of splice junctions. We demonstrate the existence of a large class of low abundance isoforms, encompassing approximately 150,000 previously unannotated splice junctions in our data. Newly-identified splice sites show little evidence of evolutionary conservation, suggesting that the majority are due to erroneous splice site choice. We show that sequence motifs involved in the recognition of exons are enriched in the vicinity of unconserved splice sites. We estimate that the average intron has a splicing error rate of approximately 0.7% and show that introns in highly expressed genes are spliced more accurately, likely due to their shorter length. These results implicate noisy splicing as an important property of genome evolution