Leveraging the Mukaiyama oxidation-reduction condensation reaction for on-resin aryl thio-esterification for bio-conjugation.

A room-temperature Mukaiyama oxidation-reduction condensation inspired thioesterification methodology has been developed to afford aryl Cα-terminal peptide thioesters on-resin. The conditions herein feature mild reactions compatible with all Fmoc-SPPS protocols offering direct access to this critical arylthioester scaffold. This one-pot synthesis to aryl-thioester functionalised peptides facilitates peptide/protein synthesis by native chemical ligation.

Updated joint ESPGHAN/NASPGHAN guidelines for management of Helicobacter pylori infection in children and adolescents (2023).

BACKGROUND: Evolving epidemiological data and increasing antibiotic resistance mandate an update of the European and North American Societies of Pediatric Gastroenterology, Hepatology and Nutrition guidelines. METHODS: Certainty of evidence and strength of recommendations were rated by experts according to the Grading of Recommendation Assessment, Development, and Evaluation approach. PICO (patient population, intervention, comparator, and outcome) questions were developed and voted on by the group. Recommendations were formulated using the Evidence to Decision framework. RESULTS: The current literature supports many of the previous recommendations and several new recommendations. Invasive testing with strain antimicrobial susceptibility analysis is recommended for the diagnosis and selection of eradication therapy for H. pylori infection. Molecular methods are acceptable for detection of infection and of antibiotic resistance in gastric biopsy specimens. Reliable, noninvasive tests can be used as a screening method for children with history of gastric cancer in a first-degree relative. When investigating causes of chronic immune thrombocytopenic purpura, testing for H. pylori is no longer recommended. When investigating other diseases such as inflammatory bowel disease, celiac disease, or eosinophilic esophagitis, specific diagnostic biopsies for H. pylori infection are not indicated. However, if H. pylori is an incidental finding, treatment may be considered after discussing the risks and benefits. Treatment should be based on antibiotic antimicrobial susceptibility testing and, if unavailable, regimens containing clarithromycin should be avoided. CONCLUSIONS: Due to decreasing prevalence of infection, increasing challenges with antibiotic resistance, and emerging evidence regarding complications of infection, clinicians must be aware of these recommended changes to appropriately manage H. pylori infection and its clinical sequelae in children.

Identifying erroneous height and weight values from adult electronic health records in the All of Us research program.

INTRODUCTION: Electronic Health Records (EHR) are a useful data source for research, but their usability is hindered by measurement errors. This study investigated an automatic error detection algorithm for adult height and weight measurements in EHR for the All of Us Research Program (All of Us). METHODS: We developed reference charts for adult heights and weights that were stratified on participant sex. Our analysis included 4,076,534 height and 5,207,328 wt measurements from âˆ¼ 150,000 participants. Errors were identified using modified standard deviation scores, differences from their expected values, and significant changes between consecutive measurements. We evaluated our method with chart-reviewed heights (8,092) and weights (9,039) from 250 randomly selected participants and compared it with the current cleaning algorithm in All of Us. RESULTS: The proposed algorithm classified 1.4 % of height and 1.5 % of weight errors in the full cohort. Sensitivity was 90.4 % (95 % CI: 79.0-96.8 %) for heights and 65.9 % (95 % CI: 56.9-74.1 %) for weights. Precision was 73.4 % (95 % CI: 60.9-83.7 %) for heights and 62.9 (95 % CI: 54.0-71.1 %) for weights. In comparison, the current cleaning algorithm has inferior performance in sensitivity (55.8 %) and precision (16.5 %) for height errors while having higher precision (94.0 %) and lower sensitivity (61.9 %) for weight errors. DISCUSSION: Our proposed algorithm outperformed in detecting height errors compared to weights. It can serve as a valuable addition to the current All of Us cleaning algorithm for identifying erroneous height values.

Synthesis, Structure-Activity Relationship Study, Bioactivity, and Nephrotoxicity Evaluation of the Proposed Structure of the Cyclic Lipodepsipeptide Brevicidine B.

The brevicidines represent a novel class of nonribosomal antimicrobial peptides that possess remarkable potency and selectivity toward highly problematic and resistant Gram-negative pathogenic bacteria. A recently discovered member of the brevicidine family, coined brevicidine B (2), comprises a single amino acid substitution (from d-Tyr2 to d-Phe2) in the amino acid sequence of the linear moiety of brevicidine (1) and was reported to exhibit broader antimicrobial activity against both Gram-negative (MIC = 2-4 µgmL-1) and Gram-positive (MIC = 2-8 µgmL-1) pathogens. Encouraged by this, we herein report the first total synthesis of the proposed structure of brevicidine B (2), building on our previously reported synthetic strategy to access brevicidine (1). In agreement with the original isolation paper, pleasingly, synthetic 2 demonstrated antimicrobial activity toward Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae (MIC = 4-8 µgmL-1). Interestingly, however, synthetic 2 was inactive toward all of the tested Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus strains. Substitution of d-Phe2 with its enantiomer, and other hydrophobic residues, yields analogues that were either inactive or only exhibited activity toward Gram-negative strains. The striking difference in the biological activity of our synthetic 2 compared to the reported natural compound warrants the re-evaluation of the original natural product for purity or possible differences in relative configuration. Finally, the evaluation of synthetic 1 and 2 in a human kidney organoid model of nephrotoxicity revealed substantial toxicity of both compounds, although 1 was less toxic than 2 and polymyxin B. These results indicate that modification to position 2 may afford a strategy to mitigate the nephrotoxicity of brevicidine.

Religious polarization and justification of belief in invisible scientific versus religious entities.

Children and adults express greater confidence in the existence of invisible scientific as compared to invisible religious entities. To further examine this differential confidence, 5- to 11-year-old Turkish children and their parents (N = 174, 122 females) from various regions in Türkiye, a country with an ongoing tension between secularism and religion, were tested in 2021 for their belief in invisible entities. Participants expressed more confidence in the existence of scientific than religious entities. For scientific entities, children justified their belief primarily by elaborating on the properties of the entity, rather than referring to the testimonial source of their judgment. This pattern was reversed for religious entities, arguably, highlighting the role of polarization in shaping the testimony children typically hear.

Classification of Breast Implant Malposition.

BACKGROUND: Implant malposition is a well-recognized complication of prosthetic breast implants. However, to date, no objective classification system has been described. OBJECTIVES: The aim of this study was to perform a prospective trial of an objective and reproducible classification system for implant malposition formulated by analyzing retrospective data from a large cohort of patients with implant malposition. METHODS: The authors retrospectively analyzed the degree of medial/lateral and inferior/superior implant malposition relative to their optimal position within the breast footprint in a series of 189 breasts (n = 100 patients). An objective classification system for implant malposition was devised and then applied to a prospective cohort of 53 breasts in 28 patients with implant malposition. RESULTS: The degree of malposition in a single or combination of axes was categorized according to the distance (measured in centimeters) from the ideal breast footprint. The classification system incorporated the axis of malposition and distance to generate a treatment decision-making guide. Cases of Grade 1 malposition did not warrant surgical intervention, whereas surgical correction was warranted in all Grade 3 cases. In the combined patient cohort (n = 242 breasts, 128 patients), lateral, inferior, medial, and superior displacement ranged between Grades 1 and 3. There was no interobserver variability in the grades assigned to 9 out of 10 patients in the prospective group. CONCLUSIONS: A simple and reproducible classification system for implant malposition has been created that allows surgeons to objectively record the extent of malposition, guides surgical decision-making, and can be used to document the results of any intervention.

NMR Shows Why a Small Chemical Change Almost Abolishes the Antimicrobial Activity of Glycocin F.

Glycocin F (GccF), a ribosomally synthesized, post-translationally modified peptide secreted by Lactobacillus plantarum KW30, rapidly inhibits the growth of susceptible bacteria at nanomolar concentrations. Previous studies have highlighted structural features important for its activity and have shown the absolute requirement for the Ser18 O-linked GlcNAc on the eight-residue loop linking the two short helices of the (C-X6-C)2 structure. Here, we show that an ostensibly very small chemical modification to Ser18, the substitution of the Cα proton with a methyl group, reduces the antimicrobial activity of GccF 1000-fold (IC50 1.5 µM cf. 1.5 nM). A comparison of the GccFα-methylSer18 NMR structure (PDB 8DFZ) with that of the native protein (PDB 2KUY) showed a marked difference in the orientation and mobility of the loop, as well as a markedly different positioning of the GlcNAc, suggesting that loop conformation, dynamics, and glycan presentation play an important role in the interaction of GccF with as yet unknown but essential physiological target molecules.

A mathematical model of cell movement and clustering due to chemotaxis.

This paper presents a numerical method for modelling cell migration and aggregation due to chemotaxis where the cell is attracted towards the direction in which the concentration of a chemical signal is increasing. In the model presented here, each cell is represented by a system of springs connected together at node points on the cell's membrane and on the boundary of the cell's nucleus. The nodes located on a cell's membrane are subject to a force which is proportional to the gradient of the concentration of the chemical signal which mimics the behaviour of the chemical receptors in the cell's membrane. In particular, the model developed here will consider what happens when two (or more) cells collide and how their membranes connect to each other to form clusters of cells. The methods described in this paper will be illustrated with a number of typical examples simulating cells moving in response to a chemical signal and how they combine to form clusters.

On-Resin Conjugation of the Ruthenium Anticancer Agent Plecstatin-1 to Peptide Vectors.

Ruthenium piano-stool complexes have been explored for their anticancer activity and some promising compounds have been reported. Herein, we conjugated a derivative of plecstatin-1 to peptides in order to increase their cancer cell targeting ability. For this purpose, plecstatin-1 was modified at the arene ligand to introduce a functional amine handle (3), which resulted in a compound that showed similar activity in an in vitro anticancer activity assay. The cell-penetrating peptide TAT48-60, tumor-targeting neurotensin8-13, and plectin-targeting peptide were functionalized with succinyl or ß-Ala-succinyl linkers under standard solid-phase peptide synthesis (SPPS) conditions to spatially separate the peptide backbones from the bioactive metal complexes. These modifications allowed for conjugating precursor 3 to the peptides on resin yielding the desired metal-peptide conjugates (MPCs), as confirmed by high-performance liquid chromatography (HPLC), NMR spectroscopy, and mass spectrometry (MS). The MPCs were studied for their behavior in aqueous solution and under acidic conditions and resembled that of the parent compound plecstatin-1. In in vitro anticancer activity studies in a small panel of cancer cell lines, the TAT-based MPCs showed the highest activity, while the other MPCs were virtually inactive. However, the MPCs were significantly less active than the small molecules plecstatin-1 and 3, which can be explained by the reduced cell uptake as determined by inductively coupled plasma MS (ICP-MS). Although the MPCs did not display potent anticancer activities, the developed conjugation strategy can be extended toward other metal complexes, which may be able to utilize the targeting properties of peptides.

Factors influencing on-resin depsipeptide bond formation: case studies on daptomycin- and brevicidine-derived sequences.

Depsipeptides are an important class of bioactive natural products, where a growing number of genome-mined structures that display anti-microbial activity are macrocyclic depsipeptides. Chemically, peptide ester (depsipeptide) bond formation often displays low yields, and thereby hampers efforts to access these structures for structure-activity studies. Herein, we present a systematic study of the variables that influence depsipeptide bond formation on-resin, using simplified sequences derived from antibiotic peptides, daptomycin and brevicidine, prepared via Fmoc-based solid-phase synthesis. Our study highlights reaction solvent as the key determinant, where switching the solvent from DMF to DCM in almost all cases increased the amount of depsipeptide product. Limiting the number of amino-acids N-terminal to the reactive alcohol was also noted to significantly improve the acylation efficiency. The impact of different N-terminal and side-chain protecting groups, as well as stereochemistry, was also investigated. Additives to the reaction, such as inclusion of surfactants for esterification of long hydrophobic sequences, did not improve conversion. 6-ClHOBt, often added to improve acylation efficiency, notably decreased the amount of depsipeptide observed. Lastly, no significant difference between polystyrene and Tentagel® (PEG-decorated) resins were found for these sequences.

Harnessing the power of a photoinitiated thiol-ene "click" reaction for the efficient synthesis of S-lipidated collagen model peptide amphiphiles.

A photoinitiated thiol-ene "click" reaction was used to synthesize S-lipidated collagen model peptide amphiphiles. Use of 2-iminothiolane provided an epimerization-free thiol handle required for thiol-ene based incorporation of lipid moieties onto collagen-based peptide sequences. This approach not only led to improvements in the triple helical characteristics of the resulting collagen model peptides but also increased the aqueous solubility of the peptide amphiphiles. As a result, this methodology holds significant potential for the design and advancement of functional peptide amphiphiles, offering enhanced capabilities across a wide range of applications.

Being nice by choice: The effect of counterfactual reasoning on children's social evaluations.

The ability to engage in counterfactual thinking (reason about what else could have happened) is critical to learning, agency, and social evaluation. However, not much is known about how individual differences in counterfactual reasoning may play a role in children's social evaluations. In the current study, we investigate how prompting children to engage in counterfactual thinking about positive moral actions impacts children's social evaluations. Eighty-seven 4-8-year-olds were introduced to a character who engaged in a positive moral action (shared a sticker with a friend) and asked about what else the character could have done with the sticker (counterfactual simulation). Children were asked to generate either a high number of counterfactuals (five alternative actions) or a low number of counterfactuals (one alternative action). Children were then asked a series of social evaluation questions contrasting that character with one who did not have a choice and had no alternatives (was told to give away the sticker to his friend). Results show that children who generated selfish counterfactuals were more likely to positively evaluate the character with choice than children who did not generate selfish counterfactuals, suggesting that generating counterfactuals most distant from the chosen action (prosociality) leads children to view prosocial actions more positively. We also found age-related changes: as children got older, regardless of the type of counterfactuals generated, they were more likely to evaluate the character with choice more positively. These results highlight the importance of counterfactual reasoning in the development of moral evaluations. RESEARCH HIGHLIGHTS: Older children were more likely to endorse agents who choose to share over those who do not have a choice. Children who were prompted to generate more counterfactuals were more likely to allocate resources to characters with choice. Children who generated selfish counterfactuals more positively evaluated agents with choice. Comparable to theories suggesting children punish willful transgressors more than accidental transgressors, we propose children also consider free will when making positive moral evaluations.

Hearing about a story character's negative emotional reaction to having been dishonest causes young children to cheat less.

There is extensive research on the development of cheating in early childhood but research on how to reduce it is rare. The present preregistered study examined whether telling young children about a story character's emotional reactions towards cheating could significantly reduce their tendency to cheat (N = 400; 199 boys; Age: 3-6 years). Results showed that telling older kindergarten children about the story character's negative emotional reaction towards rule violation significantly reduced cheating, but telling them about the positive emotional reaction towards rule adherence did not. These results show that children as young as age 5 are able to use information about another child's emotional reaction to guide their own moral behavior. In particular, highlighting another child's negative emotional reaction towards a moral transgression may be an effective way to reduce cheating in early childhood. This finding, along with earlier cheating reduction findings, suggests that although cheating is common in early childhood, simple methods can reduce its occurrence.

Structural Basis for Receptor Activity-Modifying Protein-Dependent Selective Peptide Recognition by a G Protein-Coupled Receptor.

Association of receptor activity-modifying proteins (RAMP1-3) with the G protein-coupled receptor (GPCR) calcitonin receptor-like receptor (CLR) enables selective recognition of the peptides calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) that have diverse functions in the cardiovascular and lymphatic systems. How peptides selectively bind GPCR:RAMP complexes is unknown. We report crystal structures of CGRP analog-bound CLR:RAMP1 and AM-bound CLR:RAMP2 extracellular domain heterodimers at 2.5 and 1.8 Å resolutions, respectively. The peptides similarly occupy a shared binding site on CLR with conformations characterized by a ß-turn structure near their C termini rather than the α-helical structure common to peptides that bind related GPCRs. The RAMPs augment the binding site with distinct contacts to the variable C-terminal peptide residues and elicit subtly different CLR conformations. The structures and accompanying pharmacology data reveal how a class of accessory membrane proteins modulate ligand binding of a GPCR and may inform drug development targeting CLR:RAMP complexes.

Older children verify adult claims because they are skeptical of those claims.

We investigated children's information seeking in response to a surprising claim (Study 1, N = 109, 54 Female, Range = 4.02-6.94 years, 49% White, 21% Mixed Ethnicity, 19% Southeast Asian, September 2019-March 2020; Study 2, N = 154, 74 Female, Range = 4.09-7.99, 50% White, 20% Mixed Ethnicity, 17% Southeast Asian, September 2020-December 2020). Relative to younger children, older children more often expressed skepticism about the adult's surprising claims (1-year increase, OR = 2.70) and more often suggested exploration strategies appropriate for testing the specific claim they heard (1-year increase, OR = 1.42). Controlling for age, recommending more targeted exploration strategies was associated with a greater likelihood of expressing skepticism about the adult's claim.

Beyond enjoyment: Young children consider the normative goodness of activity engagement when attributing happiness.

Individuals are typically happy when engaging in enjoyable activities. But many enjoyable activities could be harmful when engaged in to excess. Do children consider the normative goodness of activity engagement levels when attributing happiness? To examine this question, we presented children with enjoyable activities that are often harmless in moderation but harmful in excess. When told that engaging in their favorite activities at their preferred amount was either normatively good (i.e., harmless and permitted) or normatively bad (i.e., harmful and forbidden), 10- and 11-year-old and 7- and 8-year-old children (Study 1) and even 5-year-old children (Studies 2 and 3 with simplified methods) attributed less happiness when the engagement level was normatively bad than when it was normatively good both to themselves and to another child. Young children also perceived normatively bad engagement as less interesting and pleasurable (Study 3). The findings suggest that children consider the normative goodness of activity engagement (rather than enjoyment alone) when attributing happiness, illuminating how children understand happiness.

Chinese parents' support of preschoolers' mathematical development.

Research has documented the critical role played by the early home environment in children's mathematical development in Western contexts. Yet little is known about how Chinese parents support their preschoolers' development of math skills. The Chinese context is of particular interest because Chinese children outperform their Western counterparts in math, even early in development. The current study sought to fill this gap by examining a sample of 90 families of 4- and 5-year-olds from mainland China. Parental support-as measured by the frequency of parent-child engagement in home activities as well as parent number talk-and parents' role in children's numeracy skills were investigated. Results indicate wide variation among parents in both types of support. Frequency of engagement in formal numeracy activities, including counting objects and reading number story books, was related to children's knowledge of cardinality. A principal components analysis did not identify informal numeracy activities as a distinct home activity component, likely due to the infrequent occurrences of game-like numeracy activities among the Chinese families. Instead, a structured activity component emerged (e.g., playing musical instruments) and was positively related to children's arithmetic skills. Diversity, but not quantity, of parent number talk was related to children's symbolic magnitude understanding. The distinctive relationships between specific parental measures and child outcomes speak to the need for nuanced identification of home environment factors that are beneficial to particular math competencies. The findings also suggest cultural variations in the mechanisms that support children's mathematical development, highlighting the merits of investigating this topic in non-Western contexts.

Miraculous, magical, or mundane? The development of beliefs about stories with divine, magical, or realistic causation.

Children's naïve theories about causal regularities enable them to differentiate factual narratives describing real events and characters from fictional narratives describing made-up events and characters (Corriveau, Kim, Schwalen, & Harris, Cognition 113 (2): 213-225, 2009). But what happens when children are consistently presented with accounts of miraculous and causally impossible events as real occurrences? Previous research has shown that preschoolers with consistent exposure to religious teaching tend to systematically judge characters involved in fantastical or religious events as real (Corriveau et al., Cognitive Science, 39 (2), 353-382, 2015; Davoodi et al., Developmental Psychology, 52 (2), 221, 2016). In the current study, we extended this line of work by asking about the scope of the impact of religious exposure on children's reality judgments. Specifically, we asked whether this effect is  domain-general or domain-specific. We tested children in Iran, where regular exposure to uniform religious beliefs might influence children's reasoning about possibility in non-religious domains, in addition to the domain of religion. Children with no or minimal schooling (5- to 6-year-olds) and older elementary school students (9- to 10-year-olds) judged the reality status of different kinds of stories, notably realistic, unusual (but nonetheless realistic), religious, and magical stories. We found that while younger children were not systematic in their judgments, older children often judged religious stories as real but rarely judged magical stories as real. This developmental pattern suggests that the impact of religious exposure on children's reality judgments does not extend beyond their reasoning about divine intervention. Children's justifications for their reality judgments provided further support for this domain-specific influence of religious teaching.

Protein modifications due to homogenisation and heat treatment of cow milk.

This research paper aimed to locate protein modifications caused by treatment of milk and determine if the modification locations were consistent. The majority of milk for consumption is homogenised using pressure and heat, and this causes changes in the location of proteins in the milk as well as protein modifications. To investigate these proteomic changes, raw milk was pasteurised (72°C, 15 s), then, to separate the treatment for homogenisation, heated at these different pressures and temperatures: 45°C without no pressure applied, 45°C with 35 MPa, 80°C without pressure applied and 80°C, with 35 MPa. Proteomic analysis was done after separating the milk into three fractions: whey, casein and cream. Protein modifications in each fraction were examined and we found Maillard products as well as oxidation to be of interest. The proteins were also further identified and characterised to compare protein modification sites and differences in proteins present in the cream resulting from homogenisation and/or pasteurisation. This experiment showed that both heat and pressure during homogenisation can cause increases in protein modifications as a result of oxidation or the Maillard reaction. Total cysteine oxidation and total proline oxidation differed between treatments although this was only significantly different for cysteine. It was observed that protein modifications occurred in the same location in the protein sequence rather than in random locations which we highlighted by examining α-S1-casein, lactadherin and ß-lactoglobulin.

Survivin Expression in Luminal Breast Cancer and Adjacent Normal Tissue for Immuno-Oncology Applications.

Survivin (BIRC5) is a tumor-associated antigen (TAA) overexpressed in various tumors but present at low to undetectable levels in normal tissue. Survivin is known to have a high expression in breast cancer (e.g., Ductal Carcinoma in situ (DCIS) and triple negative breast cancer). Previous studies have not compared survivin expression levels in DCIS tumor samples to levels in adjacent, normal breast tissue from the same patient. To ensure the effective use of survivin as a target for T cell immunotherapy of breast cancer, it is essential to ascertain the varying levels of survivin expression between DCIS tumor tissue samples and the adjacent normal breast tissue taken from the same patient simultaneously. Next-generation sequencing of RNA (RNA-seq) in normal breast tissue and tumor breast tissue from five women presenting with DCIS for lumpectomy was used to identify sequence variation and expression levels of survivin. The identity of both tumor and adjacent normal tissue samples were corroborated by histopathology. Survivin was overexpressed in human breast tissue tumor samples relative to the corresponding adjacent human normal breast tissue. Wild-type survivin transcripts were the predominant species identified in all tumor tissue sequenced. This study demonstrates upregulated expression of wild type survivin in DCIS tumor tissue versus normal breast tissue taken from the same patient at the same time, and provides evidence that developing selective cytotoxic T lymphocyte (CTL) immunotherapy for DCIS targeting survivin warrants further study.