1,2-Difunctionalized bicyclo[1.1.1]pentanes: Long-sought-after mimetics for ortho/meta-substituted arenes.

The development of a versatile platform for the synthesis of 1,2-difunctionalized bicyclo[1.1.1]pentanes to potentially mimic ortho/meta-substituted arenes is described. The syntheses of useful building blocks bearing alcohol, amine, and carboxylic acid functional handles have been achieved from a simple common intermediate. Several ortho- and meta-substituted benzene analogs, as well as simple molecular matched pairs, have also been prepared using this platform. The results of in-depth ADME (absorption, distribution, metabolism, and excretion) investigations of these systems are presented, as well as computational studies which validate the ortho- or meta-character of these bioisosteres.

Two Days Versus Four Days of Training Cessation Following a Step-Taper in Powerlifters.

ABSTRACT: Burke, BI, Carroll, KM, Travis, SK, Stone, ME, and Stone, MH. Two days versus four days of training cessation following a step-taper in powerlifters. J Strength Cond Res 37(12): e625-e632, 2023-Tapering and training cessation are methods of training load management aimed at optimizing athlete preparedness leading into competition. Such practices are often used by strength sport athletes such as powerlifters (i.e., athletes who compete in the back squat [BS], bench press [BP], and deadlift [DL]). The purpose of this study was to compare the differences in maximal strength, subjective recovery and stress state, and body composition alterations in strength athletes undergoing a 1-week step-taper followed by either a 2-day (2D) or 4-day (4D) period of training cessation. Twelve powerlifters (22.3 ± 2.1 yrs; 92.1 ± 20.4 kg; 174.8 ± 7.5 cm) completed a 6-week training protocol aimed at peaking 1 repetition maximum (1RM) strength on BS, BP, and DL. Body composition, subjective recovery and stress state, and 1RM on BS, BP, and DL were assessed before an overreach week (T1) and after the periods of training cessation (T2) for each group. Alpha criterion was set at p ≤ 0.05. There were significant increases in BP ( p = 0.032, g = 0.10), powerlifting total ( p = 0.014, g = 0.11), and DOTS score ( p = 0.006, g = 0.12) after 2D of cessation. However, after 4D of cessation, significant increases were only observed in DL ( p = 0.019, g = 0.11) along with significant decreases in BP ( p = 0.003, g = -0.13). There were no statistically significant changes in any other variable for either group indicating that BS, psychometric, and body composition data were maintained between T1 and T2. The results of this study support the use of 1-week step-tapers, followed by a short period of training cessation (2-4D) to maintain or improve maximal strength performance.

Leveraging artificial intelligence and data science techniques in harmonizing, sharing, accessing and analyzing SARS-COV-2/COVID-19 data in Rwanda (LAISDAR Project): study design and rationale.

BACKGROUND: Since the outbreak of COVID-19 pandemic in Rwanda, a vast amount of SARS-COV-2/COVID-19-related data have been collected including COVID-19 testing and hospital routine care data. Unfortunately, those data are fragmented in silos with different data structures or formats and cannot be used to improve understanding of the disease, monitor its progress, and generate evidence to guide prevention measures. The objective of this project is to leverage the artificial intelligence (AI) and data science techniques in harmonizing datasets to support Rwandan government needs in monitoring and predicting the COVID-19 burden, including the hospital admissions and overall infection rates. METHODS: The project will gather the existing data including hospital electronic health records (EHRs), the COVID-19 testing data and will link with longitudinal data from community surveys. The open-source tools from Observational Health Data Sciences and Informatics (OHDSI) will be used to harmonize hospital EHRs through the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM). The project will also leverage other OHDSI tools for data analytics and network integration, as well as R Studio and Python. The network will include up to 15 health facilities in Rwanda, whose EHR data will be harmonized to OMOP CDM. EXPECTED RESULTS: This study will yield a technical infrastructure where the 15 participating hospitals and health centres will have EHR data in OMOP CDM format on a local Mac Mini ("data node"), together with a set of OHDSI open-source tools. A central server, or portal, will contain a data catalogue of participating sites, as well as the OHDSI tools that are used to define and manage distributed studies. The central server will also integrate the information from the national Covid-19 registry, as well as the results of the community surveys. The ultimate project outcome is the dynamic prediction modelling for COVID-19 pandemic in Rwanda. DISCUSSION: The project is the first on the African continent leveraging AI and implementation of an OMOP CDM based federated data network for data harmonization. Such infrastructure is scalable for other pandemics monitoring, outcomes predictions, and tailored response planning.

Water-Soluble Rhenium Phosphine Complexes Incorporating the Ph2C(X) Motif (X = O-, NH-): Structural and Cytotoxicity Studies.

Reaction of [ReOCl3(PPh3)2] or [ReO2I(PPh3)2] with 2,2'-diphenylglycine (dpgH2) in refluxing ethanol afforded the air-stable complex [ReO(dpgH)(dpg)(PPh3)] (1). Treatment of [ReO(OEt)I2(PPh3)2] with 1,2,3-triaza-7-phosphaadamantane (PTA) afforded the complex [ReO(OEt)I2(PTA)2] (2). Reaction of [ReOI2(PTA)3] with dpgH2 led to the isolation of the complex [Re(NCPh2)I2(PTA)3]·0.5EtOH (3·0.5EtOH). A similar reaction but using [ReOX2(PTA)3] (X = Cl, Br) resulted in the analogous halide complexes [Re(NCPh2)Cl2(PTA)3]·2EtOH (4·2EtOH) and [Re(NCPh2)(PTA)3Br2]·1.6EtOH (5·1.6EtOH). Using benzilic acid (2,2'-diphenylglycolic acid, benzH) with 2 afforded the complex [ReO(benz)2(PTA)][PTAH]·EtOH (6·EtOH). The potential for the formation of complexes using radioisotopes with relatively short half-lives suitable for nuclear medicine applications by developing conditions for [Re(NCPh2)(dpg)I(PTA)3] (7)[ReO4]- in a 4 h time scale was investigated. A procedure for the technetium analog of complex [Re(NCPh2)I2(PTA)3] (3) from 99mTc[TcO4]- was then investigated. The molecular structures of 1-7 are reported; complexes 3-7 have been studied using in vitro cell assays (HeLa, HCT116, HT-29, and HEK 293) and were found to have IC50 values in the range of 29-1858 µM.

Coping and Mental Health Differences among Active Duty Service Members and Their Spouses with High and Low Levels of Marital Warmth.

This study examined the relationship between marital warmth (e.g., openly expressing affection, supportive behaviors) and assessments of coping (i.e., challenges coping with military life and self-efficacy in the context of stress) and mental health (i.e., depressive symptoms and anxiety symptoms) in a sample of active duty men and their spouses/romantic partners (N = 234 military couples). Results from a series of multivariate analysis of variance tests indicate that service members and spouses who reported higher levels of marital warmth also reported better coping skills and mental health compared to individuals in couple relationships that demonstrated lower levels of marital warmth. Intervention and prevention implications targeting social support and marital warmth are provided.

Resensitization to Crizotinib by the Lorlatinib ALK Resistance Mutation L1198F.

In a patient who had metastatic anaplastic lymphoma kinase (ALK)-rearranged lung cancer, resistance to crizotinib developed because of a mutation in the ALK kinase domain. This mutation is predicted to result in a substitution of cysteine by tyrosine at amino acid residue 1156 (C1156Y). Her tumor did not respond to a second-generation ALK inhibitor, but it did respond to lorlatinib (PF-06463922), a third-generation inhibitor. When her tumor relapsed, sequencing of the resistant tumor revealed an ALK L1198F mutation in addition to the C1156Y mutation. The L1198F substitution confers resistance to lorlatinib through steric interference with drug binding. However, L1198F paradoxically enhances binding to crizotinib, negating the effect of C1156Y and resensitizing resistant cancers to crizotinib. The patient received crizotinib again, and her cancer-related symptoms and liver failure resolved. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT01970865.).

Visualizing Kinetically Robust CoIII4L6 Assemblies in Vivo: SPECT Imaging of the Encapsulated [99mTc]TcO4- Anion.

Noncovalent encapsulation is an attractive approach for modifying the efficacy and physiochemical properties of both therapeutic and diagnostic species. Abiotic self-assembled constructs have shown promise, yet many hurdles between in vitro and (pre)clinical studies remain, not least the challenges associated with maintaining the macromolecular, hollow structure under nonequilibrium conditions. Using a kinetically robust CoIII4L6 tetrahedron we now show the feasibility of encapsulating the most widely used precursor in clinical nuclear diagnostic imaging, the γ-emitting [99mTc]TcO4- anion, under conditions compatible with in vivo administration. Subsequent single-photon emission computed tomography imaging of the caged-anion reveals a marked change in the biodistribution compared to the thyroid-accumulating free oxo-anion, thus moving clinical applications of (metallo)supramolecular species a step closer.

Multimodal nanoparticle imaging agents: design and applications.

Molecular imaging, where the location of molecules or nanoscale constructs can be tracked in the body to report on disease or biochemical processes, is rapidly expanding to include combined modality or multimodal imaging. No single imaging technique can offer the optimum combination of properties (e.g. resolution, sensitivity, cost, availability). The rapid technological advances in hardware to scan patients, and software to process and fuse images, are pushing the boundaries of novel medical imaging approaches, and hand-in-hand with this is the requirement for advanced and specific multimodal imaging agents. These agents can be detected using a selection from radioisotope, magnetic resonance and optical imaging, among others. Nanoparticles offer great scope in this area as they lend themselves, via facile modification procedures, to act as multifunctional constructs. They have relevance as therapeutics and drug delivery agents that can be tracked by molecular imaging techniques with the particular development of applications in optically guided surgery and as radiosensitizers. There has been a huge amount of research work to produce nanoconstructs for imaging, and the parameters for successful clinical translation and validation of therapeutic applications are now becoming much better understood. It is an exciting time of progress for these agents as their potential is closer to being realized with translation into the clinic. The coming 5-10 years will be critical, as we will see if the predicted improvement in clinical outcomes becomes a reality. Some of the latest advances in combination modality agents are selected and the progression pathway to clinical trials analysed.This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.

Aspartate-Based CXCR4 Chemokine Receptor Binding of Cross-Bridged Tetraazamacrocyclic Copper(II) and Zinc(II) Complexes.

The CXCR4 chemokine receptor is implicated in a number of diseases including HIV infection and cancer development and metastasis. Previous studies have demonstrated that configurationally restricted bis-tetraazamacrocyclic metal complexes are high-affinity CXCR4 antagonists. Here, we present the synthesis of Cu(2+) and Zn(2+) acetate complexes of six cross-bridged tetraazamacrocycles to mimic their coordination interaction with the aspartate side chains known to bind them to CXCR4. X-ray crystal structures for three new Cu(2+) acetate complexes and two new Zn(2+) acetate complexes demonstrate metal-ion-dependent differences in the mode of binding the acetate ligand concomitantly with the requisite cis-V-configured cross-bridged tetraazamacrocyle. Concurrent density functional theory molecular modelling studies produced an energetic rationale for the unexpected [Zn(OAc)(H2 O)](+) coordination motif present in all of the Zn(2+) cross-bridged tetraazamacrocycle crystal structures, which differs from the chelating acetate [Zn(OAc)](+) structures of known unbridged and side-bridged tetraazamacrocyclic Zn(2+) -containing CXCR4 antagonists.

Mono- and Bis-Alkylation of Glyoxal-Bridged Tetraazamacrocycles Using Mechanochemistry.

Glyoxal-bridged bisaminal tetraazamacrocyclic derivatives of 1,4,7,10-tetraazacyclododecane (cyclen) and 1,4,8,11-tetraazacyclotetradecane (cyclam) can be N-functionalized to incorporate coordinating groups or for conjugation to biomolecules. Herein, we present an improved N-functionalization methodology using mechanochemistry which reduces reaction times in comparison with conventional synthetic routes. A range of six alkyl halides were reacted with cyclen and cyclam bisaminal derivatives in various ratios to form mono- and bis-functionalized quaternary ammonium salts. Cross-bridged cyclam, a key intermediate for CB-TE2A, a commonly used chelator in positron emission tomography medical imaging with (64)Cu, has been synthesized using nonconventional synthetic methodologies (grinding and microwave heating) with intermediates characterized by 2D NMR and single crystal XRD. The overall synthesis time of CB-TE2A from cyclam could be shortened to 5 days from the 35 days required for the conventional synthesis.

Synthesis and structural studies of two pyridine-armed reinforced cyclen chelators and their transition metal complexes.

Two novel pyridine pendant-armed macrocycles structurally reinforced by an ethyl bridge, either between adjacent nitrogens (for side-bridged) or non-adjacent nitrogens (for cross-bridged), have been synthesized and complexed with a range of transition metal ions (Co2+, Ni2+, Cu2+ and Zn2+). X-ray crystal structures of selected cross-bridged complexes were obtained which showed the characteristic cis-V configuration with potential labile cis binding sites. The complexes have been characterized by their electronic spectra and magnetic moments, which show the expected high spin divalent metal complex in most cases. Exceptions are the nickel side-bridged complex, which shows a mixture of high-spin and low spin, and the cobalt cross-bridged complex which has oxidized to cobalt(III). Cyclic voltammetry in acetonitrile was carried out to assess the potential future use of these complexes in oxidation catalysis. Selected complexes offer significant catalytic potential enhanced by the addition of the pyridyl arm to a reinforced cyclen backbone.

o-Boronato- and o-Trifluoroborato-Phosphonium Salts Supported by L-α-Amino Acid Side Chain.

The synthesis of o-boronato- and o-trifluoroborato-phosphonium salts supported by the L-amino acid side chain is described. The synthesis of these new class of amino acid derivatives was achieved by stereoselective quaternization of o-(pinacolato)boronatophenylphosphine with ß- or γ-iodo amino acid derivatives which are prepared from L-serine or L-aspartic acid, respectively. The quaternization of the phosphine was performed using either iodo amino ester or carboxylic acid derivatives. In addition, free carboxylic acid and amine derivatives were obtained by saponification or HCl acidolysis of o-boronato-phosphonium amino esters, respectively. The usefulness of these compounds in peptide coupling was demonstrated by coupling an o-boronato-phosphonium amino ester with an aspartic acid moiety. When the o-boronato-phosphonium amino acid or dipeptide derivatives were mixed with fluoride, the corresponding o-trifluoroborated products were cleanly and rapidly obtained in high isolated yields. The hydrolysis of these compounds at room temperature using a phosphate buffer pH 7/CD3CN mixture has shown only traces of free fluoride F(-) after several days. Finally, a preliminary radiolabeling essay has proven the facile [(18)F]-fluoride incorporation and high stability of the radiolabeled product in aqueous conditions. Indeed, this new class of boron-phosphonium amino acid derivatives shows promising properties for their applications in synthesis and labeling of peptides.

Effect of water solvation on the lipophilicity of isomeric pyrimidine-carboxamides.

Incorporation of nitrogen is a common medicinal chemistry tactic to reduce logD values. Neighboring group participation influences logD, so the results are isomer dependent. The logD and logP differences observed between isomeric pyrimidines 1, 2 and 3 presumably result when the carbonyl or ether lone pairs are in close proximity to a heterocyclic nitrogen lone pair, recruiting water to bridge between the electron rich atoms. Various lipophilicity calculators did not discriminate between 1 (logD=2.6) and 3 (logD=1.0), but solvation energies using Poisson-Boltzmann and 3D-RISM methods rationalize the observed differences in lipophilicity among pyrimidine carboxamide isomers.

Recent advances in chelator design and labelling methodology for (68) Ga radiopharmaceuticals.

Gallium-68 has the potential to become the technetium-99m of positron emission tomography with ideal decay characteristics and a long-lived parent isotope for generator production. The work in the area of (68) Ga is focused on two key areas: (1) synthesis of a library of bifunctional chelators, which can be quickly radiolabelled to form kinetically inert complexes under mild conditions compatible with biomolecules and (2) development of radiosynthetic methodologies for clinical use and to facilitate radiolabelling of a wide range of chelators under mild conditions. Recent advances in these areas, with particular focus on the past 3 years, are covered herein.

Microbial-Derived Exerkines Prevent Skeletal Muscle Atrophy.

Regular exercise yields a multitude of systemic benefits, many of which may be mediated through the gut microbiome. Here, we report that cecal microbial transplants (CMTs) from exercise-trained vs. sedentary mice have modest benefits in reducing skeletal muscle atrophy using a mouse model of unilaterally hindlimb-immobilization. Direct administration of top microbial-derived exerkines from an exercise-trained gut microbiome preserved muscle function and prevented skeletal muscle atrophy.

trans-IV restriction: a new configuration for metal bis-cyclam complexes as potent CXCR4 inhibitors.

The chemokine receptor CXCR4 is implicated in multiple diseases including inflammatory disorders, cancer growth and metastasis, and HIV/AIDS. CXCR4 targeting has been evaluated in treating cancer metastasis and therapy resistance. Cyclam derivatives, most notably AMD3100 (Plerixafor™), are a common motif in small molecule CXCR4 antagonists. However, AMD3100 has not been shown to be effective in cancer treatment as an individual agent. Configurational restriction and transition metal complex formation increases receptor binding affinity and residence time. In the present study, we have synthesized novel trans-IV locked cyclam-based CXCR4 inhibitors, a previously unexploited configuration, and demonstrated their higher affinity for CXCR4 binding and CXCL12-mediated signaling inhibition compared to AMD3100. These results pave the way for even more potent CXCR4 inhibitors that may provide significant efficacy in cancer therapy.

Development and Comprehensive Benchmark of a High-Quality AMBER-Consistent Small Molecule Force Field with Broad Chemical Space Coverage for Molecular Modeling and Free Energy Calculation.

Biomolecular simulations have become an essential tool in contemporary drug discovery, and molecular mechanics force fields (FFs) constitute its cornerstone. Developing a high quality and broad coverage general FF is a significant undertaking that requires substantial expert knowledge and computing resources, which is beyond the scope of general practitioners. Existing FFs originate from only a limited number of groups and organizations, and they either suffer from limited numbers of training sets, lower than desired quality because of oversimplified representations, or are costly for the molecular modeling community to access. To address these issues, in this work, we developed an AMBER-consistent small molecule FF with extensive chemical space coverage, and we provide Open Access parameters for the entire modeling community. To validate our FF, we carried out benchmarks of quantum mechanics (QM)/molecular mechanics conformer comparison and free energy perturbation calculations on several benchmark data sets. Our FF achieves a higher level of performance at reproducing QM energies and geometries than two popular open-source FFs, OpenFF2 and GAFF2. In relative binding free energy calculations for 31 protein-ligand data sets, comprising 1079 pairs of ligands, the new FF achieves an overall root-mean-square error of 1.19 kcal/mol for ΔΔG and 0.92 kcal/mol for ΔG on a subset of 463 ligands without bespoke fitting to the data sets. The results are on par with those of the leading commercial series of OPLS FFs.

Self-Assembled Nanocoatings Protect Microbial Fertilizers for Climate-Resilient Agriculture.

Chemical fertilizers have been crucial for sustaining the current global population by supplementing overused farmland to support consistent food production, but their use is unsustainable. Pseudomonas chlororaphis is a nitrogen-fixing bacterium that could be used as a fertilizer replacement, but this microbe is delicate. It is sensitive to stressors, such as freeze-drying and high temperatures. Here, we demonstrate protection of P. chlororaphis from freeze-drying, high temperatures (50 oC), and high humidity using self-assembling metal-phenolic network (MPN) coatings. The composition of the MPN is found to significantly impact its protective efficacy, and with optimized compositions, no viability loss is observed for MPN-coated microbes under conditions where uncoated cells do not survive. Further, we demonstrate that MPN-coated microbes improve germination of seeds by 150% as compared to those treated with fresh P. chlororaphis. Taken together, these results demonstrate the protective capabilities of MPNs against environmental stressors and represent a critical step towards enabling the production and storage of delicate microbes under nonideal conditions.

Seminal Vesicle Treatment for Localized Prostate Cancer Treated with External Beam Radiotherapy.

This study retrospectively reviewed data from men with localized prostate cancer treated with external beam radiotherapy (EBRT). We identified 359 men with localized prostate cancer treated with curative EBRT at the Cross Cancer Institute between 2010-2011. The volume of seminal vesicles (SVs) treated as well as dose values were extracted. These volumes were compared to gold standard contours drawn by a trained expert based on consensus European Society for Radiotherapy and Oncology (ESTRO) contouring guidelines. Patient and tumor characteristics were extracted for these patients. Memorial Sloan Kettering prostate cancer nomogram was used to assign a predicted risk of SV involvement for each patient based on baseline tumor characteristics. In patients with a predicted risk of SV involvement greater than 15% (n = 184), 86.5% (SD = 18.6) of the base of the SVs were treated with EBRT, compared to 66.7% (SD = 32.6) for patients with a predicted risk of SV involvement less than 15% (n = 175, p < 0.0001). Similarly, the mean percentage of proximal and total SV volumes treated with EBRT was 75.6% (SD = 24.4) and 68.7% (SD = 26.0) for patients with a predicted risk of SV involvement of greater than 15%, compared to 50.3% (SD = 31.0, p < 0.0001) and 41.0% (SD = 27.8, p < 0.0001) for patients with a risk of less than 15%. The results indicate that all parts of the SVs are more likely to be contoured in men with >15% risk of SV involvement than those with <15% risk. However, radiation oncologists still contour a high percentage of SVs in men with <15% risk of SV involvement, suggesting that there may be over-treatment of SVs that increases the risk of rectal or bladder toxicity.

An adaptive behavioral control motif mediated by cortical axo-axonic inhibition.

Genetically defined subgroups of inhibitory interneurons are thought to play distinct roles in learning, but heterogeneity within these subgroups has limited our understanding of the scope and nature of their specific contributions. Here we reveal that the chandelier cell (ChC), an interneuron type that specializes in inhibiting the axon-initial segment (AIS) of pyramidal neurons, establishes cortical microcircuits for organizing neural coding through selective axo-axonic synaptic plasticity. We found that organized motor control is mediated by enhanced population coding of direction-tuned premotor neurons, with tuning refined through suppression of irrelevant neuronal activity. ChCs contribute to learning-dependent refinements by providing selective inhibitory control over individual pyramidal neurons rather than global suppression. Quantitative analysis of structural plasticity across axo-axonic synapses revealed that ChCs redistributed inhibitory weights to individual pyramidal neurons during learning. These results demonstrate an adaptive logic of the inhibitory circuit motif responsible for organizing distributed neural representations. Thus, ChCs permit efficient cortical computation in a targeted cell-specific manner.