"Now I Get It!": Eureka Experiences During the Acquisition of Mathematical Concepts.

Many famous scientists have reported anecdotes where a new understanding occurred to them suddenly, in an unexpected flash. Do people generally experience such "Eureka" moments when learning science concepts? And if so, do these episodes truly vehicle sudden insights, or is this impression illusory? To address these questions, we developed a paradigm where participants were taught the mathematical concept of geodesic, which generalizes the common notion of straight line to straight trajectories drawn on curved surfaces. After studying lessons introducing this concept on the sphere, participants (N = 56) were tested on their understanding of geodesics on the sphere and on other surfaces. Our findings indicate that Eureka experiences are common when learning mathematics, with reports by 34 (61%) participants. Moreover, Eureka experiences proved an accurate description of participants' learning, in two respects. First, Eureka experiences were associated with learning and generalization: the participants who reported experiencing Eurekas performed better at identifying counterintuitive geodesics on new surfaces. Second, and in line with the firstperson experience of a sudden insight, our findings suggest that the learning mechanisms responsible for Eureka experiences are inaccessible to reflective introspection. Specifically, reports of Eureka experiences and of participants' confidence in their own understanding were associated with different profiles of performance, indicating that the mechanisms bringing about Eureka experiences and those informing reflective confidence were at least partially dissociated. Learning mathematical concepts thus appears to involve mechanisms that operate unconsciously, except when a key computational step is reached and a sudden insight breaks into consciousness.

Validation of the Clinical Use of GIScar, an Academic-developed Genomic Instability Score Predicting Sensitivity to Maintenance Olaparib for Ovarian Cancer.

PURPOSE: The optimal application of maintenance PARP inhibitor therapy for ovarian cancer requires accessible, robust, and rapid testing of homologous recombination deficiency (HRD). However, in many countries, access to HRD testing is problematic and the failure rate is high. We developed an academic HRD test to support treatment decision-making. EXPERIMENTAL DESIGN: Genomic Instability Scar (GIScar) was developed through targeted sequencing of a 127-gene panel to determine HRD status. GIScar was trained from a noninterventional study with 250 prospectively collected ovarian tumor samples. GIScar was validated on 469 DNA tumor samples from the PAOLA-1 trial evaluating maintenance olaparib for newly diagnosed ovarian cancer, and its predictive value was compared with Myriad Genetics MyChoice (MGMC). RESULTS: GIScar showed significant correlation with MGMC HRD classification (kappa statistics: 0.780). From PAOLA-1 samples, more HRD-positive tumors were identified by GIScar (258) than MGMC (242), with a lower proportion of inconclusive results (1% vs. 9%, respectively). The HRs for progression-free survival (PFS) with olaparib versus placebo were 0.45 [95% confidence interval (CI), 0.33-0.62] in GIScar-identified HRD-positive BRCA-mutated tumors, 0.50 (95% CI, 0.31-0.80) in HRD-positive BRCA-wild-type tumors, and 1.02 (95% CI, 0.74-1.40) in HRD-negative tumors. Tumors identified as HRD positive by GIScar but HRD negative by MGMC had better PFS with olaparib (HR, 0.23; 95% CI, 0.07-0.72). CONCLUSIONS: GIScar is a valuable diagnostic tool, reliably detecting HRD and predicting sensitivity to olaparib for ovarian cancer. GIScar showed high analytic concordance with MGMC test and fewer inconclusive results. GIScar is easily implemented into diagnostic laboratories with a rapid turnaround.

Functional pre-therapeutic evaluation by genome editing of variants of uncertain significance of essential tumor suppressor genes.

BACKGROUND: Targeted therapies in oncology are promising but variants of uncertain significance (VUS) limit their use for clinical management and necessitate functional testing in vitro. Using BRCA1 and BRCA2 variants, which have consequences on PARP inhibitor sensitivity, and POLE variants, potential biomarkers of immunotherapy response, we developed a rapid functional assay based on CRISPR-Cas9 genome editing to determine the functional consequences of these variants having potentially direct implications on patients' access to targeted therapies. METHODS: We first evaluated the functional impact of 26 BRCA1 and 7 BRCA2 variants by editing and comparing NGS results between the variant of interest and a silent control variant. Ten of these variants had already been classified as benign or pathogenic and were used as controls. Finally, we extended this method to the characterization of POLE VUS. RESULTS: For the 23 variants that were unclassified or for which conflicting interpretations had been reported, 15 were classified as functionally normal and 6 as functionally abnormal. Another two variants were found to have intermediate consequences, both with potential impacts on splicing. We then compared these scores to the patients' responses to PARP inhibitors when possible. Finally, to prove the application of our method to the classification of variants from other tumor suppressor genes, we exemplified with three POLE VUS. Among them, two were classified with an intermediate functional impact and one was functionally abnormal. Eventually, four POLE variants previously classified in databases were also evaluated. However, we found evidence of a discordance with the classification, variant p.Leu424Val being found here functionally normal. CONCLUSIONS: Our new rapid functional assay can be used to characterize the functional implication of BRCA1 and BRCA2 variants, giving patients whose variants were evaluated as functionally abnormal access to PARP inhibitor treatment. Retrospective analysis of patients' responses to PARP inhibitors, where accessible, was consistent with our functional score evaluation and confirmed the accuracy of our protocol. This method could potentially be extended to the classification of VUS from all essential tumor suppressor genes and can be performed within a timeframe compatible with clinical applications, thereby having a direct theranostic impact.

Using Reciprocal Transplants to Assess Local Adaptation, Genetic Rescue, and Sexual Selection in Newly Established Populations.

Small populations establishing on colonization fronts have to adapt to novel environments with limited genetic variation. The pace at which they can adapt, and the influence of genetic variation on their success, are key questions for understanding intraspecific diversity. To investigate these topics, we performed a reciprocal transplant experiment between two recently founded populations of brown trout in the sub-Antarctic Kerguelen Islands. Using individual tagging and genetic assignment methods, we tracked the fitness of local and foreign individuals, as well as the fitness of their offspring over two generations. In both populations, although not to the same extent, gene flow occurred between local and foreign gene pools. In both cases, however, we failed to detect obvious footprints of local adaptation (which should limit gene flow) and only weak support for genetic rescue (which should enhance gene flow). In the population where gene flow from foreign individuals was low, no clear differences were observed between the fitness of local, foreign, and F1 hybrid individuals. In the population where gene flow was high, foreign individuals were successful due to high mating success rather than high survival, and F1 hybrids had the same fitness as pure local offspring. These results suggest the importance of considering sexual selection, rather than just local adaptation and genetic rescue, when evaluating the determinants of success in small and recently founded populations.

Fluctuating Dynamics of Mate Availability Promote the Evolution of Flexible Choosiness in Both Sexes.

AbstractThe evolution of choosiness has a strong effect on sexual selection, as it promotes variance in mating success among individuals. The context in which choosiness is expressed, and therefore the associated gain and cost, is highly variable. An overlooked mechanism by current models is the rapid fluctuations in the availability and quality of partners, which generates a dynamic mating market to which each individual must optimally respond. We argue that the rapid fluctuations of the mating market are central to the evolution of optimal choosiness. Using a dynamic game approach, we investigate this hypothesis for various mating systems (characterized by different adult sex ratio and latency period combinations), allowing feedback between the choosiness and partner availability throughout a breeding season while taking into account the fine variation in individual quality. Our results indicate that quality-dependent and flexible choosiness usually evolve in both sexes for various mating systems and that a significant amount of variance in choosiness is observed, especially in males, even when courtship is costly. Accounting for the fluctuating dynamics of the mating market therefore allows envisioning a much wider range of choosiness variation in natural populations and may explain a number of recent empirical results regarding choosiness in the less common sex or its variance within sexes.

[Genetic instability, a factor limiting the efficiency of targeted therapies in solid oncology]. / L'instabilité génomique, paramètre limitant l'efficacité des thérapies ciblées en oncologie.

Genomic instability is one of the main properties of tumour development, promoting first the acquisition of genetic alterations and thus carcinogenesis. Then, the chronic and anarchic proliferation of cancer cells also supports and contributes to this instability allowing a continuous evolution of the tumour. The accumulation of mutations resulting from that instability contributes to tumour heterogeneity that occurs in a specific environment. The resulting diversity of oncogenic drivers further complicates the characterization of the origin of cancer cells dysfunction and consequently therapeutic decision. However, the consideration of the molecular context in oncology has initiated the development of targeted therapies. Based on the concept of oncogene addiction and synthetic lethality, these new drugs require the characterization and identification of specific tumour biomarkers. Targeted therapies have thus considerably optimized patient management, improving efficiency and quality of life while limiting the side effects observed with conventional chemotherapies. However, despite significant clinical benefits, some major limitations to their administration remain. The study of the current issues related to these new therapeutic molecules is becoming crucial for patient management towards an improvement of personalized medicine.

Non-Small-Cell Lung Cancer-Sensitive Detection of the p.Thr790Met EGFR Alteration by Preamplification before PNA-Mediated PCR Clamping and Pyrosequencing.

Targeted therapies and, more precisely, EGFR tyrosine kinase inhibitors (TKIs) have been a major improvement in the therapeutic management of EGFR-mutated non-small-cell lung cancers (NSCLCs). Earlier administration of these TKIs throughout tumor progression is imperative to improve patient outcomes. Consequently, studies have focused on refining the characterization of biomarkers, especially concerning the resistance mutation p.Thr790Met of EGFR. Herein, we developed peptide nucleic acid (PNA)-mediated PCR clamping followed by pyrosequencing, favoring enrichment of the mutated fraction. A preamplification step was first added to increase the amplifiable DNA fraction. Throughout the application of our method on DNA extracted from FFPE samples of 46 patients with NSCLC who had relapsed under first-generation EGFR TKI, we evaluated a sensitivity of 93.3% and a specificity of 100%. All 19 patients who were positive for the p.Thr790Met mutation with NGS were also found to be positive with our protocol. The only discordant case was a sample with no mutation detected with NGS, but which was positive with PNA. This protocol allows for the detection of the p.Thr790Met mutation with a sensitivity of 0.5% which will permit earlier detection and an improvement of therapeutic management.

Somatic mRNA Analysis of BRCA1 Splice Variants Provides a Direct Theranostic Impact on PARP Inhibitors.

BACKGROUND: The identification of pretherapeutic somatic BRCA variants can have considerable clinical impact given that they affect response to the new poly (ADP-ribose) polymerase (PARP)-targeted therapy. One major issue with this type of testing is the identification of splicing variants of uncertain significance (VUS) on degraded somatic messenger RNA. It is therefore important to be able to quickly characterize these splice variants. OBJECTIVE: As part of PARP inhibitor targeted therapy, we have investigated a method for the direct confirmation of potential pathogenic somatic splice variants of BRCA1 found in fixed tumor samples. Previously these VUS have commonly only been tested by in silico analysis. METHODS: Five BRCA1 variants affecting splicing were characterized from formalin-fixed, paraffin-embedded (FFPE) ovarian carcinoma tissues by next-generation sequencing (NGS). Three patient samples had already been functionally characterized and were used as controls. Total somatic RNA from samples was extracted, reverse-transcribed, and amplified with several primer pairs encompassing the target exon. The polymerase chain reaction (PCR) products were analyzed by capillary gel electrophoresis to assess possible changes in size due to splicing alterations. Finally, we confirmed our results by cloning, followed by Sanger sequencing, and analyzed the expression of the aberrant forms. RESULTS: Our molecular approach made it possible to visualize the splicing outcomes of three variants (c.5194-2A>G, c.5434C>G, and c.547+1G>A) already identified and present in databases and/or identified with prediction tools (ClinVar, UMD, ARUP Utah database, and Human Splice Finder splices sites prediction) and to confirm their exon skipping consequences, their expression in tumors, and thus their pathogenicity. The c.4484+5G>A variant was not found in databases and was predicted to have no impact on splicing, but was found to display altered processing in tumor tissue. This variant also had a major detrimental impact on transcriptional expression. CONCLUSION: In a break from purely in silico approaches, we propose a simple and rapid pretherapeutic functional analysis of somatic BRCA1 variants potentially involved in splicing alterations. This approach will allow more ovarian cancer patients to benefit from new therapies targeting PARP.

[EGFR molecular characterization in non-small cell bronchic cancer: comparative prospective study by NGS and Idylla platform technologies]. / Caractérisation moléculaire de l'EGFR dans les cancers bronchiques non à petites cellules : étude prospective comparative des technologies NGS et automate Idylla.

INTRODUCTION: Detection of genetic alterations in the EGFR tyrosine kinase domain is a major concern in the management of non-small cell lung cancer because it conditions access to tyrosine kinase inhibitors. In practice, it is possible to characterize only well-documented mutations or to sequence all relevant EGFR exons and also other targets of theranostic interest. This prospective study compares the targeted EGFR characterization on Idylla platform (Biocartis) and a more extensive one by next generation sequencing using Ion Torrent technology. MATERIAL AND METHODS: A total of 100 formalin-fixed paraffin-embedded tumour samples were tested simultaneously by both techniques under the conditions recommended by the suppliers. The comparison covered all technical and practical aspects of the laboratory. RESULTS: At least one EGFR mutation of interest for tyrosine kinase inhibitors for 9 and 7 samples was detected respectively by sequencing and by the Idylla system. For three samples, EGFR sensitive mutations to tyrosine kinase inhibitors were detected only by next-generation sequencing. In addition, for 37 samples, mutations of clinical interest outside EGFR were characterized by sequencing and communicated to the prescriber. CONCLUSION: Idylla technology allows the rapid characterization of a majority of EGFR variants. The result can be optimized by careful analysis of the amplification curves with the Idylla Explore tool or by increasing the amount of initial material. A complementary new generation sequencing analysis for non-contributory results by Idylla should also be recommended.

Lactic Acidosis Together with GM-CSF and M-CSF Induces Human Macrophages toward an Inflammatory Protumor Phenotype.

In established tumors, tumor-associated macrophages (TAM) orchestrate nonresolving cancer-related inflammation and produce mediators favoring tumor growth, metastasis, and angiogenesis. However, the factors conferring inflammatory and protumor properties on human macrophages remain largely unknown. Most solid tumors have high lactate content. We therefore analyzed the impact of lactate on human monocyte differentiation. We report that prolonged lactic acidosis induces the differentiation of monocytes into macrophages with a phenotype including protumor and inflammatory characteristics. These cells produce tumor growth factors, inflammatory cytokines, and chemokines as well as low amounts of IL10. These effects of lactate require its metabolism and are associated with hypoxia-inducible factor-1α stabilization. The expression of some lactate-induced genes is dependent on autocrine M-CSF consumption. Finally, TAMs with protumor and inflammatory characteristics (VEGFhigh CXCL8+ IL1ß+) are found in solid ovarian tumors. These results show that tumor-derived lactate links the protumor features of TAMs with their inflammatory properties. Treatments that reduce tumor glycolysis or tumor-associated acidosis may help combat cancer.

Benefits versus risk profile of buparlisib for the treatment of breast cancer.

Introduction: Activation of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways occurs in 70% of breast cancer, including PIK3CA activating mutations, PTEN loss and AKT mutation. It is associated with poor prognosis and resistance to anti-HER2 and endocrine therapy. PI3K inhibitors are promising anticancer targets that can reverse resistance to these therapies. Buparlisib (BKM-120) is an orally active pan-PI3K inhibitor evaluated in different solid tumors as monotherapy or in combination. Areas covered: This article reviews preclinical data, clinical studies that have evaluated the efficacy and safety profiles of buparlisib as a monotherapy or in combination with targeted therapy (including endocrine and anti-HER2 therapy) or cytotoxics. The authors cover completed and ongoing studies to evaluate the benefit vs risk profile of buparlisib. Expert opinion: Targeting PI3K showed efficacy in BC. Buparlisib, a pan PI3K inhibitor, presents manageable but not negligible toxicity with an activity/toxicity ratio in favor of the use of emerging second generation, α-selective PI3K inhibitors for ongoing and future trials.

Isonatric Dialysis Biofeedback in Hemodiafiltration with Online Regeneration of Ultrafiltrate in Hypertensive Hemodialysis Patients: A Randomized Controlled Study.

UNLABELLED: Dialysis biofeedback in hemodiafiltration with online regeneration of ultrafiltrate (HFR) could help to improve arterial hypertension. We evaluated the impact of isonatric HFR (HFR-iso) on hypertension control compared to conventional HFR. Forty-seven hemodialysis patients were included and randomized (ratio 2/1) HFR-iso versus HFR during 24 dialysis sessions. In the HFR-iso group (32 patients, 768 dialysis sessions), the predialytic systolic blood pressure (BP) decreased from S1 to S24 of 9 ± 20 mm Hg and increased of 5 ± 24 mm Hg in the HFR group (15 patients, 360 dialysis sessions), variation that differed between the 2 groups (x0394;S1-S24, p = 0.035; interaction group*time, p = 0.012). The diastolic BP (HFR-iso -3 ± 14 mm Hg vs. HFR 5 ± 13 mm Hg; p = 0.088), the DDD of antihypertensive treatment and the dry weight did not vary significantly during the study. Number of sessions complicated by symptomatic hypotension was similar in the 2 groups. HFR-iso improved BP control without increasing dialysis hypotension episodes. SHORT SUMMARY: In this multicenter, open-label, controlled, randomized study, we evaluated the impact of dialysis biofeedback in HFR on arterial hypertension compared to conventional HFR. We observed that HFR-iso improved arterial BP control without increasing dialysis hypotension episodes.

[Impact on professional practices of a care protocol implemented between usual hospital care and hospital at home]. / Impacts sur les pratiques professionnelles d’un protocole de soins mis en place entre l’hospitalisation avec hébergement et l’hospitalisation à domicile.

BACKGROUND: Implementation of a care protocol between usual hospital care and hospital at home (HAH) could improve the quality of care and decrease fragmentations of the French healthcare system. This study evaluated the impact on professional practices of a care protocol implemented between a surgery unit and hospital at home. METHODS: Twenty healthcare professionals (nurses, head nurses, physicians) from HAH and a Paris public hospital urology unit were interviewed by a public heath physician. Semistructured interviews were analyzed using the grounded theory. RESULTS: Professional practices were modified with better traceability of care, greater safety for professionals and for patients, standardization of practices and improved continuity of interventions between hospital and hospital at home. However, these changes in practices appeared to be limited to the protocol itself and indicated potential enhancement of technical aspects to the detriment of human contact. CONCLUSION: This care protocol has an encouraging impact on the quality of care. These results demonstrate the value of extending this approach to other wards to improve continuity of care between usual hospital care and hospital at home.