Current Preclinical Testing of New Hip Arthroplasty Technologies Does Not Reflect Real-World Loadings: Capturing Patient-Specific and Activity-Related Variation in Hip Contact Forces

Background: Total hip replacement (THR) implants are routinely tested for their tribological performance through regulatory pre-clinical wear testing (e.g. ISO-14242). The standardized loading conditions defined in these tests consist of simplified waveforms, which do not specifically represent in vivo loads in different groups of patients. The aim of this study was to investigate, through musculoskeletal modelling, patient-specific and activity-related variation in hip contact forces (HCFs) in a large cohort of THR patients during common activities of daily living (ADLs). Methods: 132 THR patients participated in a motion-capture analysis while performing different ADLs, including walk, fast walk, stair ascent and descent (locomotor); sit-to-stand, stand-to-sit, squat and lunge (non-locomotor). HCFs were then calculated using the AnyBody Modelling System and qualitatively compared across all activities. The influence of gender on HCFs was analysed through statistical parametric mapping (SPM) analysis. Results: Systematic differences were found in HCF magnitudes and individual components in both locomotor and non-locomotor ADLs. The qualitative analysis of the ADLs revealed a large range and a large variability of forces experienced at the hip during different activities. Significant differences in the three-dimensional loading patterns were observed between males and females across most activities. Conclusions: THR patients present a large variability in the forces experienced at the hip joint during their daily life. The inter-patient variation might partially explain the heterogeneity observed in implant survival rates. A more extensive pre-clinical implant testing standard, under clinically relevant loading conditions has been advocated to better predict and avoid clinical wear problems

HLA Class I Binding 9mer Peptides from Influenza A Virus Induce CD4+ T Cell Responses

BACKGROUND: Identification of human leukocyte antigen class I (HLA-I) restricted cytotoxic T cell (CTL) epitopes from influenza virus is of importance for the development of new effective peptide-based vaccines. METHODOLOGY/PRINCIPAL FINDINGS: In the present work, bioinformatics was used to predict 9mer peptides derived from available influenza A viral proteins with binding affinity for at least one of the 12 HLA-I supertypes. The predicted peptides were then selected in a way that ensured maximal coverage of the available influenza A strains. One hundred and thirty one peptides were synthesized and their binding affinities for the HLA-I supertypes were measured in a biochemical assay. Influenza-specific T cell responses towards the peptides were quantified using IFNgamma ELISPOT assays with peripheral blood mononuclear cells (PBMC) from adult healthy HLA-I typed donors as responder cells. Of the 131 peptides, 21 were found to induce T cell responses in 19 donors. In the ELISPOT assay, five peptides induced responses that could be totally blocked by the pan-specific anti-HLA-I antibody W6/32, whereas 15 peptides induced responses that could be completely blocked in the presence of the pan-specific anti-HLA class II (HLA-II) antibody IVA12. Blocking of HLA-II subtype reactivity revealed that 8 and 6 peptide responses were blocked by anti-HLA-DR and -DP antibodies, respectively. Peptide reactivity of PBMC depleted of CD4(+) or CD8(+) T cells prior to the ELISPOT culture revealed that effectors are either CD4(+) (the majority of reactivities) or CD8(+) T cells, never a mixture of these subsets. Three of the peptides, recognized by CD4(+) T cells showed binding to recombinant DRA1*0101/DRB1*0401 or DRA1*0101/DRB5*0101 molecules in a recently developed biochemical assay. CONCLUSIONS/SIGNIFICANCE: HLA-I binding 9mer influenza virus-derived peptides induce in many cases CD4(+) T cell responses restricted by HLA-II molecules

Gene expression profiling of meningiomas: current status after a decade of microarray-based transcriptomic studies

Purpose This article provides a review of the transcriptomic expression profiling studies that have been performed on meningiomas so far. We discuss some future prospects and challenges ahead in the field of gene expression profiling. Methods We performed a systematic search in the PubMed and EMBASE databases in May 2010 using the following search terms alone or in combination: “meningioma”, “microarray analysis”, “oligonucleotide array sequence analysis”, or “gene expression profiling”. Only original research articles in English that had used RNA hybridized to high-resolution microarray chips to generate gene expression profiles were included. Results We identified 13 articles matching the inclusion criteria. All studies had been performed during the last decade. Conclusions The main results of the studies can be grouped in three categories: (1) several groups have identified meningioma-specific genes and genes associated with the three WHO grades, and the main histological subtypes of grade I meningiomas; (2) one publication has shown that the general transcription profile of samples of all WHO grades differs in vivo and in vitro; (3) one report provides evidence that microarray technology can be used in an automated fashion to classify tumors. Due to lack of consensus on how microarray data are presented, possible general trends found across the studies are difficult to extract. This could obstruct the discovery of important genes and pathways universally involved in meningioma biology

SNHG16 is regulated by the Wnt pathway in colorectal cancer and affects genes involved in lipid metabolism

It is well established that lncRNAs are aberrantly expressed in cancer where they have been shown to act as oncogenes or tumor suppressors. RNA profiling of 314 colorectal adenomas/adenocarcinomas and 292 adjacent normal colon mucosa samples using RNA‐sequencing demonstrated that the snoRNA host gene 16 (SNHG16) is significantly up‐regulated in adenomas and all stages of CRC. SNHG16 expression was positively correlated to the expression of Wnt‐regulated transcription factors, including ASCL2, ETS2, and c‐Myc. In vitro abrogation of Wnt signaling in CRC cells reduced the expression of SNHG16 indicating that SNHG16 is regulated by the Wnt pathway. Silencing of SNHG16 resulted in reduced viability, increased apoptotic cell death and impaired cell migration. The SNHG16 silencing particularly affected expression of genes involved in lipid metabolism. A connection between SNHG16 and genes involved in lipid metabolism was also observed in clinical tumors. Argonaute CrossLinking and ImmunoPrecipitation (AGO‐CLIP) demonstrated that SNHG16 heavily binds AGO and has 27 AGO/miRNA target sites along its length, indicating that SNHG16 may act as a competing endogenous RNA (ceRNA) “sponging” miRNAs off their cognate targets. Most interestingly, half of the miRNA families with high confidence targets on SNHG16 also target the 3′UTR of Stearoyl‐CoA Desaturase (SCD). SCD is involved in lipid metabolism and is down‐regulated upon SNHG16 silencing. In conclusion, up‐regulation of SNHG16 is a frequent event in CRC, likely caused by deregulated Wnt signaling. In vitro analyses demonstrate that SNHG16 may play an oncogenic role in CRC and that it affects genes involved in lipid metabolism, possible through ceRNA related mechanisms

Dapagliflozin in HFrEF Patients Treated With Mineralocorticoid Receptor Antagonists An Analysis of DAPA-HF

OBJECTIVES The purpose of this study was to assess the efficacy and safety of dapagliflozin in patients taking or not taking an mineralocorticoid receptor antagonist (MRA) at baseline in the DAPA-HF (Dapagliflozin And Prevention of Adverse outcomes in Heart Failure) trial. BACKGROUND MRAs and sodium glucose co-transporter 2 inhibitors each have diuretic activity, lower blood pressure, and reduce glomerular filtration rate (GFR). Therefore, it is important to investigate the safety, as well as efficacy, of their combination. METHODS A total of 4,744 patients with heart failure with reduced ejection fraction (HFrEF) were randomized to placebo or dapagliflozin 10mg daily. The efficacy of dapagliflozin on the primary composite outcome (cardiovascular death or episode of worsening heart failure) and its components was examined according to MRA use, as were predefined safety outcomes. RESULTS A total of 3,370 patients (71%) were treated with an MRA and they were younger (65 vs. 69 years of age), less often from North America (9% vs. 26%), had worse New York Heart Association functional class (35% vs. 25% in class III/ IV), lower left ventricular ejection fraction (30.7% vs. 31.9%) and systolic blood pressure (120.3 vs. 125.5 mm Hg), but higher estimated GFR (67.1 vs. 62.6 ml/min/1.73 m(2)), than patients not taking an MRA. The benefit of dapagliflozin compared with placebo was similar in patients taking or not taking an MRA: hazard ratio: 0.74 (95% confidence interval [CI]: 0.63 to 0.87) versus 0.74 (95% CI: 0.57 to 0.95), respectively, for the primary endpoint (p value for interaction - 0.97); similar findings were observed for secondary endpoints. In both MRA subgroups, safety outcomes were similar in patients randomized to dapagliflozin or placebo. CONCLUSIONS Dapagliflozin was similarly efficacious and safe in patients with HFrEF taking or not taking an MRA, supporting the use of both drugs together. (Study to Evaluate the Effect of Dapagliflozin on the Incidence of Worsening Heart Failure or Cardiovascular Death in Patients With Chronic Heart Failure [DAPA-HF]; NCT03036124) (C)2021 Published by Elsevier on behalf of the American College of Cardiology Foundation

Amino Acid Similarity Accounts for T Cell Cross-Reactivity and for “Holes” in the T Cell Repertoire

Background: Cytotoxic T cell (CTL) cross-reactivity is believed to play a pivotal role in generating immune responses but the extent and mechanisms of CTL cross-reactivity remain largely unknown. Several studies suggest that CTL clones can recognize highly diverse peptides, some sharing no obvious sequence identity. The emerging realization in the field is that T cell receptors (TcR) recognize multiple distinct ligands. Principal Findings: First, we analyzed peptide scans of the HIV epitope SLFNTVATL (SFL9) and found that TCR specificity is position dependent and that biochemically similar amino acid substitutions do not drastically affect recognition. Inspired by this, we developed a general model of TCR peptide recognition using amino acid similarity matrices and found that such a model was able to predict the cross-reactivity of a diverse set of CTL epitopes. With this model, we were able to demonstrate that seemingly distinct T cell epitopes, i.e., ones with low sequence identity, are in fact more biochemically similar than expected. Additionally, an analysis of HIV immunogenicity data with our model showed that CTLs have the tendency to respond mostly to peptides that do not resemble self-antigens. Conclusions: T cell cross-reactivity can thus, to an extent greater than earlier appreciated, be explained by amino acid similarity. The results presented in this paper will help resolving some of the long-lasting discussions in the field of T cel

Identification of CD8+ T Cell Epitopes in the West Nile Virus Polyprotein by Reverse-Immunology Using NetCTL

West Nile virus (WNV) is a growing threat to public health and a greater understanding of the immune response raised against WNV is important for the development of prophylactic and therapeutic strategies.In a reverse-immunology approach, we used bioinformatics methods to predict WNV-specific CD8(+) T cell epitopes and selected a set of peptides that constitutes maximum coverage of 20 fully-sequenced WNV strains. We then tested these putative epitopes for cellular reactivity in a cohort of WNV-infected patients. We identified 26 new CD8(+) T cell epitopes, which we propose are restricted by 11 different HLA class I alleles. Aiming for optimal coverage of human populations, we suggest that 11 of these new WNV epitopes would be sufficient to cover from 48% to 93% of ethnic populations in various areas of the World.The 26 identified CD8(+) T cell epitopes contribute to our knowledge of the immune response against WNV infection and greatly extend the list of known WNV CD8(+) T cell epitopes. A polytope incorporating these and other epitopes could possibly serve as the basis for a WNV vaccine