Single-Molecule Investigation of the Binding Interface Stability of SARS-CoV-2 Variants with ACE2

The SARS-CoV-2 pandemic spurred numerous research endeavors to comprehend the virus and mitigate its global severity. Understanding the binding interface between the virus and human receptors is pivotal to these efforts and paramount to curbing infection and transmission. Here we employ atomic force microscopy and steered molecular dynamics simulation to explore SARS-CoV-2 receptor binding domain (RBD) variants and angiotensin-converting enzyme 2 (ACE2), examining the impact of mutations at key residues upon binding affinity. Our results show that the Omicron and Delta variants possess strengthened binding affinity in comparison to the Mu variant. Further, using sera from individuals either vaccinated or with acquired immunity following Delta strain infection, we assess the impact of immunity upon variant RBD/ACE2 complex formation. Single-molecule force spectroscopy analysis suggests that vaccination before infection may provide stronger protection across variants. These results underscore the need to monitor antigenic changes in order to continue developing innovative and effective SARS-CoV-2 abrogation strategies.

Preparation of Dinitrogen Trioxide for Organic Synthesis: A Phase Equilibrium Approach

Dinitrogen trioxide (N2O3) is a potent nitrosating agent featured with high reactivity and appealing atom economy. Because of its instability and the entanglement of chemical and phase equilibria, N2O3 has rarely been utilized in organic synthesis as a stock reagent with well-defined composition. In this review, the preparations of pure N2O3 and its concentrated solution (>0.1 M) are discussed from the aspect of phase equilibrium. Understanding the physical and chemical characteristics of N2O3, along with how reaction parameters (temperature, pressure, molar ratio) interact, plays a crucial role in managing the concentration of N2O3 in the liquid phase. This control holds practical significance in achieving quantitative reactions.

Effects of semaglutide-loaded lipid nanocapsules on metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a highly prevalent chronic liver disease that can progress to end-stage conditions with life-threatening complications, but no pharmacologic therapy has been approved. Drug delivery systems such as lipid nanocapsules (LNC) are very versatile platforms that are easy to produce and can induce the secretion of the native glucagon-like peptide 1 (GLP-1) when orally administered. GLP-1 analogs are currently being studied in clinical trials in the context of MASLD. Our nanosystem provides with increased levels of the native GLP-1 and increased plasmatic absorption of the encapsulated GLP-1 analog (semaglutide). Our goal was to use our strategy to demonstrate a better outcome and a greater impact on the metabolic syndrome associated with MASLD and on liver disease progression with our strategy compared with the oral marketed version of semaglutide, Rybelsus®. Therefore, we studied the effect of our nanocarriers on a dietary mouse model of MASLD, the Western diet model, during a daily chronic treatment of 4 weeks. Overall, the results showed a positive impact of semaglutide-loaded lipid nanocapsules towards the normalization of glucose homeostasis and insulin resistance. In the liver, there were no significant changes in lipid accumulation, but an improvement in markers related to inflammation was observed. Overall, our strategy had a positive trend on the metabolic syndrome and at reducing inflammation, mitigating the progression of the disease. Oral administration of the nanosystem was more efficient at preventing the progression of the disease to more severe states when compared to the administration of Rybelsus®, as a suspension.

Top-down attention does not modulate mechanical hypersensitivity consecutive to central sensitization: insights from an experimental analysis

ABSTRACT

According to the neurocognitive model of attention to pain, when the attentional resources invested in a task unrelated to pain are high, limited cognitive resources can be directed toward the pain. This is supported by experimental studies showing that diverting people's attention away from acute pain leads to experiencing less pain. Theoretical work has suggested that this phenomenon may present a top-down modulatory mechanism for persistent pain as well. However, conclusive empirical evidence is lacking. To fill this gap, we used a preregistered, double-blind, between-subject study design to investigate whether performing a tailored, demanding, and engaging working memory task unrelated to pain (difficult) vs a task that requires less mental effort to be performed (easy), could lead to lower development of secondary hypersensitivity-a hallmark of central sensitization. Eighty-five healthy volunteers, randomly assigned to one of the 2 conditions, performed a visual task with a different cognitive load (difficult vs easy), while secondary hypersensitivity was induced on their nondominant forearm using high-frequency stimulation. To assess the development of secondary hypersensitivity, sensitivity to mechanical stimuli was measured 3 times: T0, for baseline and 20 (T1) and 40 (T2) minutes after the procedure. We did not observe any significant difference in the development of secondary hypersensitivity between the 2 groups, neither in terms of the intensity of mechanical sensitivity nor its spatial extent. Our results suggest that a top-down modulation through attention might not be sufficient to affect pain sensitization and the development of secondary hypersensitivity.

Examining the Link Between Implementation Fidelity, Quality, and Effectiveness of Teacher-Delivered Anti-Bullying Interventions in a Randomized Controlled Trial

This study examined the relation between both implementation fidelity and quality and the outcomes of two different anti-bullying interventions targeting distinct processes involved in bullying: moral disengagement and social norms. In total, 34 French-speaking Belgian teachers from six elementary schools were trained to deliver either the moral disengagement or the social norms intervention to their Grade 4-6 students (N = 747, 50.4% boys) in a randomized controlled trial. Students reported their moral disengagement, perceived injunctive class norm toward bullying, and bullying behaviors in the fall and spring of the 2018-2019 school year. Teachers' implementation fidelity and quality were assessed through direct observation in each class by two independent raters with a satisfying interrater reliability. A multiplicative moderated mediation model using latent change scores revealed that both greater fidelity and quality amplified students' decrease in moral disengagement, which was accompanied by a decrease in bullying. Importantly, when quality was sufficient, fidelity did not matter. However, higher fidelity could compensate for a lack of quality. Contrary to expectations, there was no significant change in students' perceptions of the class injunctive norm, even under ideal implementation conditions. Alternative mediators should thus be considered. Because implementation by teachers inevitably fluctuates, anti-bullying program components should be evaluated under various implementation conditions to determine their cost-effectiveness ratio and to gain insights into how anti-bullying programs work.

Preclinical evaluation of CDK4 phosphorylation predicts high sensitivity of pleural mesotheliomas to CDK4/6 inhibition

Malignant pleural mesothelioma (MPM) is an aggressive cancer with limited therapeutic options. We evaluated the impact of CDK4/6 inhibition by palbociclib in 28 MPM cell lines including 19 patient-derived ones, using various approaches including RNA-sequencing. Palbociclib strongly and durably inhibited the proliferation of 23 cell lines, indicating a unique sensitivity of MPM to CDK4/6 inhibition. When observed, insensitivity to palbociclib was mostly explained by the lack of active T172-phosphorylated CDK4. This was associated with high p16INK4A (CDKN2A) levels that accompany RB1 defects or inactivation, or (unexpectedly) CCNE1 overexpression in the presence of wild-type RB1. Prolonged palbociclib treatment irreversibly inhibited proliferation despite re-induction of cell cycle genes upon drug washout. A senescence-associated secretory phenotype including various potentially immunogenic components was irreversibly induced. Phosphorylated CDK4 was detected in 80% of 47 MPMs indicating their sensitivity to CDK4/6 inhibitors. Its absence in some highly proliferative MPMs was linked to very high p16 (CDKN2A) expression, which was also observed in public datasets in tumours from short-survival patients. Our study supports the evaluation of CDK4/6 inhibitors for MPM treatment, in monotherapy or combination therapy.

Shaping the chromatin landscape at rRNA and tRNA genes, an emerging new role for RNA polymerase II transcription?

Eukaryotic genes must be condensed into chromatin while remaining accessible to the transcriptional machinery to support gene expression. Among the three eukaryotic RNA polymerases (RNAP), RNAPII is unique, partly because of the C-terminal domain (CTD) of its largest subunit, Rpb1. Rpb1 CTD can be extensively modified during the transcription cycle, allowing for the co-transcriptional recruitment of specific interacting proteins. These include chromatin remodeling factors that control the opening or closing of chromatin. How the CTD-less RNAPI and RNAPIII deal with chromatin at rRNA and tRNA genes is less understood. Here, we review recent advances in our understanding of how the chromatin at tRNA genes and rRNA genes can be remodeled in response to environmental cues in yeast, with a particular focus on the role of local RNAPII transcription in recruiting chromatin remodelers at these loci. In fission yeast, RNAPII transcription at tRNA genes is important to re-establish a chromatin environment permissive to tRNA transcription, which supports growth from stationary phase. In contrast, local RNAPII transcription at rRNA genes correlates with the closing of the chromatin in starvation in budding and fission yeast, suggesting a role in establishing silent chromatin. These opposite roles might support a general model where RNAPII transcription recruits chromatin remodelers to tRNA and rRNA genes to promote the closing and reopening of chromatin in response to the environment.

Toxicological, biochemical, and in silico investigations of three trehalase inhibitors for new ways to control aphids

Insect trehalases have been identified as promising new targets for pest control. These key enzymes are involved in trehalose hydrolysis and plays an important role in insect growth and development. In this contribution, plant and microbial compounds, namely validamycin A, amygdalin, and phloridzin, were evaluated for their effect, through trehalase inhibition, on Acyrthosiphon pisum aphid. The latter is part of the Aphididae family, main pests as phytovirus vectors and being very harmful for crops. Validamycin A was confirmed as an excellent trehalase inhibitor with an half maximal inhibitory concentration and inhibitor constant of 2.2 × 10-7 and 5 × 10-8 M, respectively, with a mortality rate of ~80% on a A. pisum population. Unlike validamycin A, the insect lethal efficacy of amygdalin and phloridzin did not correspond to their trehalase inhibition, probably due to their hydrolysis by insect β-glucosidases. Our docking studies showed that none of the three compounds can bind to the trehalase active site, unlike their hydrolyzed counterparts, that is, validoxylamine A, phloretin, and prunasin. Validoxylamine A would be by far the best trehalase binder, followed by phloretin and prunasin.

PDGFRA K385 mutants in myxoid glioneuronal tumors promote receptor dimerization and oncogenic signaling

Myxoid glioneuronal tumors (MGNT) are low-grade glioneuronal neoplasms composed of oligodendrocyte-like cells in a mucin-rich stroma. These tumors feature a unique dinucleotide change at codon 385 in the platelet-derived growth factor receptor α (encoded by the PDGFRA gene), resulting in the substitution of lysine 385 into leucine or isoleucine. The functional consequences of these mutations remain largely unexplored. Here, we demonstrated their oncogenic potential in fibroblast and Ba/F3 transformation assays. We showed that the K385I and K385L mutants activate STAT and AKT signaling in the absence of ligand. Co-immunoprecipitations and BRET experiments suggested that the mutations stabilized the active dimeric conformation of the receptor, pointing to a new mechanism of oncogenic PDGF receptor activation. Furthermore, we evaluated the sensitivity of these mutants to three FDA-approved tyrosine kinase inhibitors: imatinib, dasatinib, and avapritinib, which effectively suppressed the constitutive activity of the mutant receptors. Finally, K385 substitution into another hydrophobic amino acid also activated the receptor. Interestingly, K385M was reported in a few cases of brain tumors but not in MGNT. Our results provide valuable insights into the molecular mechanism underlying the activation of PDGFRα by the K385I/L mutations, highlighting their potential as actionable targets in the treatment of myxoid glioneuronal tumors.

Health-seeking behaviour and beliefs around sore throat in The Gambia: A qualitative study

Group A Streptococcus (Strep A) bacteria causes a broad spectrum of diseases. The most common manifestations of Strep A infection are sore throat and pus-producing skin infections such as impetigo. Complications of Strep A infection can lead to inflammation in the bones, muscles, joints, and internal organs causing acute rheumatic fever and rheumatic heart disease (RHD). In The Gambia, the RHD burden is thought to be very high. However, epidemiological data is minimal, and Strep A control programmes do not exist. This study aimed to explore common beliefs and practices related to sore throats among primary caregivers of children, and healthcare providers in a community with a high Strep A disease burden. Four informal conversations with providers and fifteen semi-structured interviews with caregivers were conducted in the peri-urban area of Sukuta, The Gambia. Sampling was purposive and gradual, beginning from households identified to have recently experienced sore throat through a parallel cohort study. Themes explored in qualitative analysis included: sore throat causal attributions and diagnoses, care practises, health-seeking behaviour, and perceived barriers to using the biomedical sector. We found that sore throats were typically perceived to affect one child in a family, disproportionately or exclusively. Sore throats were rarely perceived as life-threatening, and awareness of links between sore throat and ARF or RHD was not reported among caregivers or providers in this study population. Most cases of sore throat were initially managed at home using traditional medicine which delayed resort to antibiotics, though in two instances of severe pain with the presence of exudate, fear that the child's life was at risk prompted care-seeking through the formal health system. Our findings can inform the development of tailored strategies to increase community knowledge of the potential long-term consequences of sore throats and appropriate care-seeking, alongside improvements in the health system, to prevent Strep A sequelae effectively.

Highly Sensitive Detection of Melanin in Melanomas Using Multi-harmonic Low Frequency EPR

PURPOSE

Low frequency EPR can noninvasively detect endogenous free radical melanin in melanocytic skin lesions and could potentially discriminate between benign atypical nevi and malignant melanoma lesions. We recently succeeded in demonstrating the ability of clinical EPR to noninvasively detect the endogenous melanin free radical in skin lesions of patients. However, the signal-to-noise ratio (SNR) was extremely low warranting further research to boost the sensitivity of detection. In the present study, we assessed the performance of a clinical EPR system with the capability to perform multi-harmonic (MH) analysis for the detection of melanin.

PROCEDURES

The sensitivity of MH-EPR was compared with a classical continuous wave (CW)-EPR (1st harmonic) detection in vitro in melanin phantoms, in vivo in melanoma models with cells implanted in the skin, in lymph nodes and having colonized the lungs, and finally on phantoms placed at the surface of human skin.

RESULTS

In vitro, we observed an increase in SNR by a factor of 10 in flat melanin phantoms when using MH analysis compared to CW combined with an increase in modulation amplitude. In B16 melanomas having grown in the skin of hairless mice, we observed a boost in sensitivity in vivo similar to that observed in vitro with the capability to detect melanoma cells at an earlier stage of development. MH-EPR was also able to detect non-invasively the melanin signal coming from melanoma cells present in lymph nodes as well as in lungs. We also observed a boost of sensitivity using phantoms of melanin placed at the surface of human skin.

CONCLUSIONS

Overall, our results are paving the way for new clinical trials that will use MH clinical EPR for the characterization of pigmented skin lesions.

Predicting health behaviors during the COVID-19 pandemic: A longitudinal study

We investigated the social, emotional, and cognitive predictors of adherence to four health behaviors (handwashing, mask wearing, social contact limitations, and physical distancing) during one critical phase of the COVID-19 pandemic. We collected data (N = 5803, mean age = 53; 57% women) in Belgium at five time points between April and July 2021, a time during which infections evolved from high (third wave of the pandemic) to low numbers of COVID-19 cases. The results show that the social, emotional, and cognitive predictors achieved high levels of explained variance (R2 > .60). In particular, the central components of behavioral change (attitudes, intentions, control, habits, norms, and risk) were the strongest and most consistent predictors of health behaviors over time. Likewise, autonomous motivation and empathetic emotions (e.g., attentive, compassionate) had a positive impact on health behavior adherence, whereas it was the opposite for lively emotions (e.g., active, enthusiastic). These results offer policymakers actionable insights into the most potent and stable factors associated with health behaviors, equipping them with effective strategies to curtail the spread of future infectious diseases.

A brittle star is born: Ontogeny of luminous capabilities in Amphiura filiformis

Bioluminescence is the production of visible light by living organisms thanks to a chemical reaction, implying the oxidation of a substrate called luciferin catalyzed by an enzyme, the luciferase. The luminous brittle star Amphiura filiformis depends on coelenterazine (i.e., the most widespread luciferin in marine ecosystems) and a luciferase homologous to the cnidarian Renilla luciferase to produce blue flashes in the arm's spine. Only a few studies have focused on the ontogenic apparitions of bioluminescence in marine organisms. Like most ophiuroids, A. filiformis displays planktonic ophiopluteus larvae for which the ability to produce light was not investigated. This study aims to document the apparition of the luminous capabilities of this species during its ontogenic development, from the egg to settlement. Through biochemical assays, pharmacological stimulation, and Renilla-like luciferase immunohistological detection across different developing stages, we pointed out the emergence of the luminous capabilities after the ophiopluteus larval metamorphosis into a juvenile. In conclusion, we demonstrated that the larval pelagic stage of A. filiformis is not bioluminescent compared to juveniles and adults.

Life tables in entomology: A discussion on tables' parameters and the importance of raw data

Life tables are one of the most common tools to describe the biology of insect species and their response to environmental conditions. Although the benefits of life tables are beyond question, we raise some doubts about the completeness of the information reported in life tables. To substantiate these doubts, we consider a case study (Corcyra cephalonica) for which the raw dataset is available. The data suggest that the Gaussian approximation of the development times which is implied by the average and standard error usually reported in life tables does not describe reliably the actual distribution of the data which can be misleading and hide interesting biological aspects. Furthermore, it can be risky when life table data are used to build models to predict the demographic changes of the population. The present study highlights this aspect by comparing the impulse response generated by the raw data and by its Gaussian approximation based on the mean and the standard error. The conclusions of this paper highlight: i) the importance of adding more information to life tables and, ii) the role of raw data to ensure the completeness of this kind of studies. Given the importance of raw data, we also point out the need for further developments of a standard in the community for sharing and analysing data of life tables experiments.

Intensified Continuous Flow Process for the Scalable Production of Bio-Based Glycerol Carbonate

A subtle combination of fundamental and applied organic chemistry toward process intensification is demonstrated for the large-scale production of bio-based glycerol carbonate under flow conditions. The direct carbonation of bio-based glycidol with CO2 is successfully carried out under intensified flow conditions, with Barton's base as a potent homogeneous organocatalyst. Process metrics for the CO2 coupling step (for the upstream production, output: 3.6 kg day-1 , Space Time Yield (STY): 2.7 kg h-1  L-1 , Environmental factor (E-factor): 4.7) outclass previous reports. High conversion and selectivity are achieved in less than 30 s of residence time at pilot scale with a stoichiometric amount of CO2 . Supporting DFT computations reveal the unique features of the mechanism in presence of Brønsted bases.

From cryogenic to on-scalp magnetoencephalography for the evaluation of paediatric epilepsy

Magnetoencephalography (MEG) is a neurophysiological technique based on the detection of brain magnetic fields. Whole-head MEG systems typically house a few hundred sensors requiring cryogenic cooling in a rigid one-size-fits-all (commonly adult-sized) helmet to keep a thermal insulation space. This leads to an increased brain-to-sensor distance in children, because of their smaller head circumference, and decreased signal-to-noise ratio. MEG allows detection and localization of interictal and ictal epileptiform discharges, and pathological high frequency oscillations, as a part of the presurgical assessment of children with refractory focal epilepsy, where electroencephalography is not contributive. MEG can also map the eloquent cortex before surgical resection. MEG also provides insights into the physiopathology of both generalized and focal epilepsy. On-scalp recordings based on cryogenic-free sensors have demonstrated their use in the field of childhood focal epilepsy and should become a reference technique for diagnosing epilepsy in the paediatric population. WHAT THIS PAPER ADDS: Magnetoencephalography (MEG) contributes to the diagnosis and understanding of paediatric epilepsy. On-scalp MEG recordings demonstrate some advantages over cryogenic MEG.

Exploring the links between types 2 diabetes and liver-related complications: A comprehensive review

In recent decades, the prevalence of type 2 diabetes has been steadily increasing, presenting a significant global public health challenge. These epidemiological trends can be attributed to significant lifestyle changes in modern societies, characterized by sedentary behavior and the consumption of hypercaloric, highly processed foods, along with the aging of the human population. As a result, it has become crucial for both public healthcare systems and healthcare providers to prioritize the management of diabetes and identify its systemic consequences. Emerging research has shed light on the links and risks between diabetes and liver events. This comprehensive review aims to explore the complex interplay between type 2 diabetes mellitus and liver-related outcomes, especially hepatocellular carcinoma and cirrhosis, offering insights into effective methods for detecting liver risk in individuals with diabetes. Additionally, the review will assess the various treatments that could hold the potential for positive outcomes in managing both diabetes and metabolic dysfunction-associated steatotic liver disease and liver fibrosis.

Similar efficacy outcomes with peripheral blood stem cell versus bone marrow for autologous stem cell transplantation in acute myeloid leukemia: Long-term follow-up of the EORTC-GIMEMA randomized AML-10 trial

We report here the long-term follow-up of the only prospective randomized trial of autologous hematopoietic stem cell transplantation (auto-HSCT) with peripheral blood stem cells (APBSCT) versus auto-HSCT with bone marrow (ABMT) in acute myeloid leukemia (AML) patients in first remission (CR). We observed that among patients alive and still in CR 5 years after planned auto-HSCT, approximately 10% of the patients died in the following 10 years. This stresses the need for long-term close surveillance of AML patients after auto-HSCT. Further, long-term follow-up of the trial confirms that APBSCT was comparable to ABMT in term of disease-free-survival and overall survival.

Hepatocellular carcinoma in patients with non-alcoholic fatty liver disease is associated with heterogeneous pattern of fat infiltration in skeletal muscles

OBJECTIVES

To evaluate the association between fat infiltration in skeletal muscles (myosteatosis) and hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

In a cross-sectional cohort of 72 histologically proven NAFLD patients (n = 38 with non-alcoholic steatohepatitis; NASH), among which 20 had HCC diagnosed on biopsy, we used proton density fat fraction (PDFF) at MRI to evaluate myosteatosis in skeletal muscles (mean fat fraction and first order radiomic-based pattern) at the third lumbar level, namely in erector spinae (ES), quadratus lumborum (QL), psoas, oblique, and rectus muscles.

RESULTS

PDFFES was 70% higher in patients with HCC when compared to those without HCC (9.6 ± 5.5% versus 5.7 ± 3.0%, respectively, p < 0.001). In multivariate logistic regression, PDFFES was a significant predictor of the presence of HCC (AUC = 0.72, 95% CI 0.57-0.86, p = 0.002) independently from age, sex, visceral fat area, and liver fibrosis stage (all p < 0.05). The relationship between PDFFES and HCC was exacerbated in patients with NASH (AUC = 0.79, 95% CI 0.63-0.86, p = 0.006). In patients with NASH, radiomics features of heterogeneity such as energy and entropy in any of the paraspinal muscles (i.e., ES, QL, or psoas) were independent predictors of HCC. EnergyES identified patients with HCC (n = 13) in the NASH population with AUC = 0.92 (95% CI 0.82-1.00, p < 0.001).

CONCLUSION

In patients with NAFLD, and more specifically in those with NASH, the degree and heterogeneity of myosteatosis is independently associated with HCC irrespective of liver fibrosis stage.

CLINICAL RELEVANCE STATEMENT

Our data suggest that myosteatosis could be used as a biomarker of HCC in the ever-expanding NAFLD population and pave the way for further investigation in longitudinal studies.

KEY POINTS

• HCC in patients with non-alcoholic fatty liver disease, and more specifically in those with non-alcoholic steatohepatitis, is independently associated with severe fatty infiltration (myosteatosis) of paravertebral skeletal muscles. • Association between myosteatosis and HCC is independent from liver fibrosis stage. • Histogram-based radiomics features of myosteatosis predicts the risk of HCC in patients with non-alcoholic steatohepatitis.

Eye movements reveal that young school children shift attention when solving additions and subtractions

Adults shift their attention to the right or to the left along a spatial continuum when solving additions and subtractions, respectively. Studies suggest that these shifts not only support the exact computation of the results but also anticipatively narrow down the range of plausible answers when processing the operands. However, little is known on when and how these attentional shifts arise in childhood during the acquisition of arithmetic. Here, an eye-tracker with high spatio-temporal resolution was used to measure spontaneous eye movements, used as a proxy for attentional shifts, while children of 2nd (8 y-o; N = 50) and 4th (10 y-o; N = 48) Grade solved simple additions (e.g., 4+3) and subtractions (e.g., 3-2). Gaze patterns revealed horizontal and vertical attentional shifts in both groups. Critically, horizontal eye movements were observed in 4th Graders as soon as the first operand and the operator were presented and thus before the beginning of the exact computation. In 2nd Graders, attentional shifts were only observed after the presentation of the second operand just before the response was made. This demonstrates that spatial attention is recruited when children solve arithmetic problems, even in the early stages of learning mathematics. The time course of these attentional shifts suggests that with practice in arithmetic children start to use spatial attention to anticipatively guide the search for the answer and facilitate the implementation of solving procedures. RESEARCH HIGHLIGHTS: Additions and subtractions are associated to right and left attentional shifts in adults, but it is unknown when these mechanisms arise in childhood. Children of 8-10 years old solved single-digit additions and subtractions while looking at a blank screen. Eye movements showed that children of 8 years old already show spatial biases possibly to represent the response when knowing both operands. Children of 10 years old shift attention before knowing the second operand to anticipatively guide the search for plausible answers.

The cytoskeleton adaptor protein Sorbs1 controls the development of lymphatic and venous vessels in zebrafish

BACKGROUND

Lymphangiogenesis, the formation of lymphatic vessels, is tightly linked to the development of the venous vasculature, both at the cellular and molecular levels. Here, we identify a novel role for Sorbs1, the founding member of the SoHo family of cytoskeleton adaptor proteins, in vascular and lymphatic development in the zebrafish.

RESULTS

We show that Sorbs1 is required for secondary sprouting and emergence of several vascular structures specifically derived from the axial vein. Most notably, formation of the precursor parachordal lymphatic structures is affected in sorbs1 mutant embryos, severely impacting the establishment of the trunk lymphatic vessel network. Interestingly, we show that Sorbs1 interacts with the BMP pathway and could function outside of Vegfc signaling. Mechanistically, Sorbs1 controls FAK/Src signaling and subsequently impacts on the cytoskeleton processes regulated by Rac1 and RhoA GTPases. Inactivation of Sorbs1 altered cell-extracellular matrix (ECM) contacts rearrangement and cytoskeleton dynamics, leading to specific defects in endothelial cell migratory and adhesive properties.

CONCLUSIONS

Overall, using in vitro and in vivo assays, we identify Sorbs1 as an important regulator of venous and lymphatic angiogenesis independently of the Vegfc signaling axis. These results provide a better understanding of the complexity found within context-specific vascular and lymphatic development.

Thioarylation of 6-Amino-2,3,6-trideoxy-d-manno-oct-2-ulosonic Acid (IminoKdo): Access to 3,6-Disubstituted Picolinates and Mechanistic Insights

In this work, we present a metal-free coupling protocol for the regio- and stereoselective C3-thioarylation of 6-amino-2,3,6-trideoxy-d-manno-oct-2-ulosonic acid (iminoKdo). The developed procedure enables the coupling of electron-rich, electron-deficient, and hindered arylthiols, providing a series of C3-modified iminoKdo derivatives in moderate to good yields. Elucidation of active species through controlled experimental studies and time-lapse 31 P NMR analysis provides insights into the reaction mechanism. We demonstrate that, following a tandem Staudinger/aza-Wittig reaction of an azido-containing keto ester, an inseparable equimolar mixture of imine/enamine is formed. The enamine then undergoes a Stork-like nucleophilic attack with the in situ-formed disulfide reagent, resulting in the formation of the coupling products. Additionally, we describe a rarely reported acid-promoted aromatization of the C3-thioarylated iminoKdo skeleton into 3,6-disubstituted picolinates, which are reminiscent of dichotomines.

First comprehensive untargeted metabolomics study of suramin-treated Trypanosoma brucei: an integrated data analysis workflow from multifactor data modelling to functional analysis

INTRODUCTION

Human African trypanosomiasis, commonly known as sleeping sickness, is a vector-borne parasitic disease prevalent in sub-Saharan Africa and transmitted by the tsetse fly. Suramin, a medication with a long history of clinical use, has demonstrated varied modes of action against Trypanosoma brucei. This study employs a comprehensive workflow to investigate the metabolic effects of suramin on T. brucei, utilizing a multimodal metabolomics approach.

OBJECTIVES

The primary aim of this study is to comprehensively analyze the metabolic impact of suramin on T. brucei using a combined liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) approach. Statistical analyses, encompassing multivariate analysis and pathway enrichment analysis, are applied to elucidate significant variations and metabolic changes resulting from suramin treatment.

METHODS

A detailed methodology involving the integration of high-resolution data from LC-MS and NMR techniques is presented. The study conducts a thorough analysis of metabolite profiles in both suramin-treated and control T. brucei brucei samples. Statistical techniques, including ANOVA-simultaneous component analysis (ASCA), principal component analysis (PCA), ANOVA 2 analysis, and bootstrap tests, are employed to discern the effects of suramin treatment on the metabolomics outcomes.

RESULTS

Our investigation reveals substantial differences in metabolic profiles between the control and suramin-treated groups. ASCA and PCA analysis confirm distinct separation between these groups in both MS-negative and NMR analyses. Furthermore, ANOVA 2 analysis and bootstrap tests confirmed the significance of treatment, time, and interaction effects on the metabolomics outcomes. Functional analysis of the data from LC-MS highlighted the impact of treatment on amino-acid, and amino-sugar and nucleotide-sugar metabolism, while time effects were observed on carbon intermediary metabolism (notably glycolysis and di- and tricarboxylic acids of the succinate production pathway and tricarboxylic acid (TCA) cycle).

CONCLUSION

Through the integration of LC-MS and NMR techniques coupled with advanced statistical analyses, this study identifies distinctive metabolic signatures and pathways associated with suramin treatment in T. brucei. These findings contribute to a deeper understanding of the pharmacological impact of suramin and have the potential to inform the development of more efficacious therapeutic strategies against African trypanosomiasis.

The many faces of compensation: The similarities and differences between social and facial models of perception

Previous research shows that stereotypes can distort the visual representation of groups in a top-down fashion. In the present endeavor, we tested if the compensation effect-the negative relationship that emerges between the social dimensions of warmth and competence when judging two social targets-would bias the visual representations of these targets in a compensatory way. We captured participants' near spontaneous facial prototypes of social targets by means of an unconstrained technique, namely the reverse correlation. We relied on a large multi-phase study (N = 869) and found that the expectations of the facial content of two novel groups that differed on one of the two social dimensions are biased in a compensatory manner on the facial dimensions of trustworthiness, warmth, and dominance but not competence. The present research opens new avenues by showing that compensation not only manifests itself on abstract ratings but that it also orients the visual representations of social targets.