New method for detection of complex 3D fracture motion - Verification of an optical motion analysis system for biomechanical studies

<p>Abstract</p> <p>Background</p> <p>Fracture-healing depends on interfragmentary motion. For improved osteosynthesis and fracture-healing, the micromotion between fracture fragments is undergoing intensive research. The detection of 3D micromotions at the fracture gap still presents a challenge for conventional tactile measurement systems. Optical measurement systems may be easier to use than conventional systems, but, as yet, cannot guarantee accuracy. The purpose of this study was to validate the optical measurement system PONTOS 5M for use in biomechanical research, including measurement of micromotion.</p> <p>Methods</p> <p>A standardized transverse fracture model was created to detect interfragmentary motions under axial loadings of up to 200 N. Measurements were performed using the optical measurement system and compared with a conventional high-accuracy tactile system consisting of 3 standard digital dial indicators (1 μm resolution; 5 μm error limit).</p> <p>Results</p> <p>We found that the deviation in the mean average motion detection between the systems was at most 5.3 μm, indicating that detection of micromotion was possible with the optical measurement system. Furthermore, we could show two considerable advantages while using the optical measurement system. Only with the optical system interfragmentary motion could be analyzed directly at the fracture gap. Furthermore, the calibration of the optical system could be performed faster, safer and easier than that of the tactile system.</p> <p>Conclusion</p> <p>The PONTOS 5 M optical measurement system appears to be a favorable alternative to previously used tactile measurement systems for biomechanical applications. Easy handling, combined with a high accuracy for 3D detection of micromotions (≤ 5 μm), suggests the likelihood of high user acceptance. This study was performed in the context of the deployment of a new implant (dynamic locking screw; Synthes, Oberdorf, Switzerland).</p

A streamlined pipeline for multiplexed quantitative site-specific N-glycoproteomics

Regulation of protein N-glycosylation is essential in human cells. However, large-scale, accurate, and site-specific quantification of glycosylation is still technically challenging. We here introduce SugarQuant, an integrated mass spectrometry-based pipeline comprising protein aggregation capture (PAC)-based sample preparation, multi-notch MS3 acquisition (Glyco-SPS-MS3) and a data-processing tool (GlycoBinder) that enables confident identification and quantification of intact glycopeptides in complex biological samples. PAC significantly reduces sample-handling time without compromising sensitivity. Glyco-SPS-MS3 combines high-resolution MS2 and MS3 scans, resulting in enhanced reporter signals of isobaric mass tags, improved detection of N-glycopeptide fragments, and lowered interference in multiplexed quantification. GlycoBinder enables streamlined processing of Glyco-SPS-MS3 data, followed by a two-step database search, which increases the identification rates of glycopeptides by 22% compared with conventional strategies. We apply SugarQuant to identify and quantify more than 5,000 unique glycoforms in Burkitt’s lymphoma cells, and determine site-specific glycosylation changes that occurred upon inhibition of fucosylation at high confidence

Direct observation of homogeneous cavitation in nanopores

We report on the evaporation of hexane from porous alumina and silicon membranes. These membranes contain billions of independent nanopores tailored to an ink-bottle shape, where a cavity several tens of nanometers in diameter is separated from the bulk vapor by a constriction. For alumina membranes with narrow enough constrictions, we demonstrate that cavity evaporation proceeds by cavitation. Measurements of the pressure dependence of the cavitation rate follow the predictions of the bulk, homogeneous, classical nucleation theory, definitively establishing the relevance of homogeneous cavitation as an evaporation mechanism in mesoporous materials. Our results imply that porous alumina membranes are a promising new system to study liquids in a deeply metastable state.Comment: 14 pages , 4 figures. Source files also contain Supplemental Material (Doebele_HomogeneousCavitationMembranes_SM.pdf

Biomechanical comparison of menisci from different species and artificial constructs

Background: Loss of meniscal tissue is correlated with early osteoarthritis but few data exist regarding detailed biomechanical properties (e. g. viscoelastic behavior) of menisci in different species commonly used as animal models. The purpose of the current study was to biomechanically characterize bovine, ovine, and porcine menisci (each n = 6, midpart of the medial meniscus) and compare their properties to that of normal and degenerated human menisci (n = 6) and two commercially available artificial scaffolds (each n = 3). Methods: Samples were tested in a cyclic, minimally constraint compression-relaxation test with a universal testing machine allowing the characterization of the viscoelastic properties including stiffness, residual force and relative sample compression. T-tests were used to compare the biomechanical parameters of all samples. Significance level was set at p &lt; 0.05. Results: Throughout cyclic testing stiffness, residual force and relative sample compression increased significantly (p &lt; 0.05) in all tested meniscus samples. From the tested animal meniscus samples the ovine menisci showed the highest biomechanical similarity to human menisci in terms of stiffness (human: 8.54 N/mm +/- 1.87, cycle 1; ovine: 11.24 N/mm +/- 2.36, cycle 1, p = 0.0528), residual force (human: 2.99 N +/- 0.63, cycle 1 vs. ovine 3.24 N +/- 0.13, cycle 1, p = 0.364) and relative sample compression (human 19.92\% +/- 0.63, cycle 1 vs. 18.72\% +/- 1.84 in ovine samples at cycle 1, p = 0.162). The artificial constructs - as hypothesized- revealed statistically significant inferior biomechanical properties. Conclusions: For future research the use of ovine meniscus would be desirable showing the highest biomechanical similarities to human meniscus tissue. The significantly different biomechanical properties of the artificial scaffolds highlight the necessity of cellular ingrowth and formation of extracellular matrix to gain viscoelastic properties. As a consequence, a period of unloading (at least partial weight bearing) is necessary, until the remodeling process in the scaffold is sufficient to withstand forces during weight bearing

A Changing of the Guard: Immune Checkpoint Inhibitors With and Without Chemotherapy as First Line Treatment for Metastatic Non-small Cell Lung Cancer

Inhibitory antibodies targeting programmed death protein 1 (PD-1) and programmed death ligand 1 (PD-L1) have resulted in improved outcomes for many patients with metastatic non-small cell lung cancer in (NSCLC) in the second-line setting due to their ability to lead to prolonged anti-tumor immune responses. Combining these immunotherapies with platinum-based chemotherapy as first-line treatment has resulted in improved response rates and increased survival when compared to platinum-based chemotherapy alone. Certain patient populations may even benefit from immune checkpoint inhibitors as monotherapy in the first-line setting. The PD-1 inhibitor pembrolizumab is approved as monotherapy or in combination with platinum + pemetrexed for most newly diagnosed patients with metastatic NSCLC, excluding those with a targetable oncogene such as ALK and EGFR. The PD-L1 inhibitor atezolizumab is also approved in combination with bevacizumab + carboplatin + paclitaxel for the same population, with some parts of the world also approving this regimen for patients with ALK rearrangements or EGFR activating mutations. However, there are many other chemo-immunotherapy regimens that have been evaluated as initial treatment in metastatic NSCLC. Additionally, combinations of PD-1 axis inhibitors with cytotoxic T lymphocyte antigen-4 inhibitors have been examined, although none are yet approved. Here we review the clinical data in support of the current first-line approaches across histologies and biomarker subtypes, as well as highlight future research directions revealed by the current data

Rapidly Acquired Resistance to EGFR Tyrosine Kinase Inhibitors in NSCLC Cell Lines through De-Repression of FGFR2 and FGFR3 Expression

Despite initial and sometimes dramatic responses of specific NSCLC tumors to EGFR TKIs, nearly all will develop resistance and relapse. Gene expression analysis of NSCLC cell lines treated with the EGFR TKI, gefitinib, revealed increased levels of FGFR2 and FGFR3 mRNA. Analysis of gefitinib action on a larger panel of NSCLC cell lines verified that FGFR2 and FGFR3 expression is increased at the mRNA and protein level in NSCLC cell lines in which the EGFR is dominant for growth signaling, but not in cell lines where EGFR signaling is absent. A luciferase reporter containing 2.5 kilobases of fgfr2 5′ flanking sequence was activated after gefitinib treatment, indicating transcriptional regulation as a contributing mechanism controlling increased FGFR2 expression. Induction of FGFR2 and FGFR3 protein as well as fgfr2-luc activity was also observed with Erbitux, an EGFR-specific monoclonal antibody. Moreover, inhibitors of c-Src and MEK stimulated fgfr2-luc activity to a similar degree as gefitinib, suggesting that these pathways may mediate EGFR-dependent repression of FGFR2 and FGFR3. Importantly, our studies demonstrate that EGFR TKI-induced FGFR2 and FGFR3 are capable of mediating FGF2 and FGF7 stimulated ERK activation as well as FGF-stimulated transformed growth in the setting of EGFR TKIs. In conclusion, this study highlights EGFR TKI-induced FGFR2 and FGFR3 signaling as a novel and rapid mechanism of acquired resistance to EGFR TKIs and suggests that treatment of NSCLC patients with combinations of EGFR and FGFR specific TKIs may be a strategy to enhance efficacy of single EGFR inhibitors

Patient-reported outcomes from STARTRK-2: a global phase II basket study of entrectinib for ROS1 fusion-positive non-small-cell lung cancer and NTRK fusion-positive solid tumours.

Patient-reported outcomes (PROs) are increasingly relevant endpoints in clinical trials, contributing to our understanding of risk-benefit profiles, in addition to efficacy and safety data. We investigated the impact of entrectinib on patient-reported symptoms, functioning, and health-related quality of life. STARTRK-2 is a phase II basket study in patients with locally advanced/metastatic neurotrophic receptor tyrosine kinase 1/2/3 (NTRK1/2/3) and ROS proto-oncogene 1 (ROS1) fusion-positive solid tumours. PROs (prespecified secondary endpoint) were evaluated using the European Organization for Research and Treatment of Cancer quality-of-life questionnaire (QLQ-C30), lung cancer module (QLQ-LC13), and colorectal cancer module (QLQ-CR29), and the EuroQoL 5-Dimension 3-Level instruments, completed before cycle 1 day 1 and each subsequent 4-week cycle of entrectinib dosing, and the end of treatment. Adverse events and treatment-related symptoms were assessed in the safety analysis (SA)-PRO population. Tumour-related symptoms, functioning, and global health status were assessed in the efficacy analysis (EA)-PRO population. Data cut-offs: 31 October 2018 NTRK cohort; 01 May 2019 ROS1 cohort. SA-PRO populations comprised patients with NTRK fusion-positive solid tumours (N = 88) or ROS1 fusion-positive non-small-cell lung cancer (N = 180) who received one or more doses of entrectinib, completed PRO questionnaires on cycle 1 day 1 and answered one or more questions on-study. EA-PRO populations (N = 71) and (N = 145), respectively, comprised SA-PRO patients with measurable baseline disease. Moderate-to-high baseline global health status scores were maintained in EA-PRO populations during treatment. Role and physical functioning scores were moderate-to-high at baseline, with trends towards clinical improvement during treatment. Both cohorts reported low-to-moderate symptom burden at baseline, which was maintained or trended towards clinically meaningful improvement. Symptoms commonly associated with cancer treatment (e.g. nausea, fatigue) remained stable or improved during treatment. All SA-PRO patients experienced one or more adverse events, most frequently constipation or diarrhoea. PRO findings were consistent with the favourable safety profile of entrectinib, and further reinforce the positive benefit-risk profile of this treatment, indicating minimal overall treatment burden.This study was supported by F. Hoffmann-La Roche Ltd.S