Mistranslating tRNA variants have anticodon- and sex-specific impacts on Drosophila melanogaster.

Transfer RNAs (tRNAs) are vital in determining the specificity of translation. Mutations in tRNA genes can result in the misincorporation of amino acids into nascent polypeptides in a process known as mistranslation. Since mistranslation has different impacts, depending on the type of amino acid substitution, our goal here was to compare the impact of different mistranslating tRNASer variants on fly development, lifespan, and behaviour. We established two mistranslating fly lines, one with a tRNASer variant that misincorporates serine at valine codons (V→S) and the other that misincorporates serine at threonine codons (T→S). While both mistranslating tRNAs increased development time and developmental lethality, the severity of the impacts differed depending on amino acid substitution and sex. The V→S variant extended embryonic, larval, and pupal development whereas the T→S only extended larval and pupal development. Females, but not males, containing either mistranslating tRNA presented with significantly more anatomical deformities than controls. Since mistranslation disrupts cellular translation and proteostasis, we also tested the hypothesis that tRNA variants impact fly lifespan. Interestingly, mistranslating females experienced extended lifespan whereas mistranslating male lifespan was unaffected. Consistent with delayed neurodegeneration and beneficial effects of mistranslation, mistranslating flies from both sexes showed improved locomotion as they aged. The ability of mistranslating tRNA variants to have both positive and negative effects on fly physiology and behaviour has important implications for human health given the prevalence of tRNA variants in humans.

Effectiveness and implementation of decentralized, community- and primary care-based strategies in promoting hepatitis B testing uptake: a systematic review and meta-analysis.

Background: Expanding chronic hepatitis B (CHB) testing through effective implementation strategies in primary- and community-care setting is crucial for elimination. Our study aimed to determine the effectiveness of all available strategies in the literature and evaluate their specifications and implementation outcomes, thereby informing future programming and policymaking. Methods: We conducted a systematic review and meta-analysis (PROSPERO CRD42023455781), searching Scopus, Embase, PubMed, and CINAHL databases up to June 05, 2024, for randomized controlled trials investigating primary- and community-care-based implementation strategies to promote CHB testing. Studies were screened against a priori eligibility criteria, and their data were extracted using a standardized protocol if included. ROB-2 was used to assess the risk of bias. Implementation strategies' components were characterized using the Behavior Change Wheel (BCW) framework. Random-effect models were applied to pool the effectiveness estimate by strategy. Mixed-effect meta-regression was employed to investigate if effectiveness varied by the number of strategy's BCW components. Findings: 7146 unique records were identified. 25 studies were eligible for the review, contributing 130,598 participants. 19 studies were included in the meta-analysis. No studies were conducted in low-and-middle-income countries. Implementation outcomes were reported in only ten studies (40%). Community-based strategies included lay health workers-led education (Pooled Risk Difference = 27.9% [95% Confidence Interval = 3.4-52.4], I2 = 99.3%) or crowdsourced education on social media (3.1% [-2.2 to 8.4], 0.0%). Primary care-based strategies consisted of electronic alert system (8.4% [3.7-13.1], 95.0%) and healthcare providers-led education (HCPs, 62.5% [53.1-71.9], 27.5%). The number of BCW-framework-driven strategy components showed a significant dose-response relationship with effectiveness. Interpretation: HCPs-led education stands out, and more enriched multicomponent strategies had better effectiveness. Future implementation strategies should consider critical contextual factors and policies to achieve a sustainable impact towards hepatitis B elimination targets. Funding: Tran Dolch Post-Doctoral Fellowship in Hepatology, Johns Hopkins University School of Medicine, Baltimore MD, USA.

Optimising inter-patient image registration for image-based data mining in breast radiotherapy.

Background and purpose: Image-based data mining (IBDM) requires spatial normalisation to reference anatomy, which is challenging in breast radiotherapy due to variations in the treatment position, breast shape and volume. We aim to optimise spatial normalisation for breast IBDM. Materials and methods: Data from 996 patients treated with radiotherapy for early-stage breast cancer, recruited in the REQUITE study, were included. Patients were treated supine (n = 811), with either bilateral or ipsilateral arm(s) raised (551/260, respectively) or in prone position (n = 185). Four deformable image registration (DIR) configurations for extrathoracic spatial normalisation were tested. We selected the best-performing DIR configuration and further investigated two pathways: i) registering prone/supine cohorts independently and ii) registering all patients to a supine reference. The impact of arm positioning in the supine cohort was quantified. DIR accuracy was estimated using Normalised Cross Correlation (NCC), Dice Similarity Coefficient (DSC), mean Distance to Agreement (MDA), 95 % Hausdorff Distance (95 %HD), and inter-patient landmark registration uncertainty (ILRU). Results: DIR using B-spline and normalised mutual information (NMI) performed the best across all evaluation metrics. Supine-supine registrations yielded highest accuracy (0.98 ± 0.01, 0.91 ± 0.04, 0.23 ± 0.19 cm, 1.17 ± 1.18 cm, 0.51 ± 0.26 cm for NCC, DSC, MDA, 95 %HD, and ILRU), followed by prone-prone and supine-prone registrations. Arm positioning had no significant impact on registration performance. For the best DIR strategy, uncertainty of 0.44 and 0.81 cm in the breast and shoulder regions was found. Conclusions: B-spline algorithm using NMI and registered supine and prone cohorts independently provides the most optimal spatial normalisation strategy for breast IBDM.

Association Between Surgeon Sex and Days Alive at Home Following Surgery: A Population-Based Cohort Study.

Objective: The objective of this study was to measure potential associations between surgeon sex and number of days alive and at home (DAH). Background: Patients treated by female surgeons appear to have lower rates of mortality, complications, readmissions, and healthcare costs when compared with male surgeons. DAH is a validated measure, shown to better capture the patient experience of postoperative recovery. Methods: We conducted a retrospective study of adults (≥18 years of age) undergoing common surgeries between January 01, 2007 and December 31, 2019 in Ontario, Canada. The outcome measures were the number of DAH within 30-, 90-, and 365-days. The data was summarized using descriptive statistics and adjusted using multivariable generalized estimating equations. Results: During the study period, 1,165,711 individuals were included, of which 61.9% (N = 721,575) were female. Those managed by a female surgeon experienced a higher mean number of DAH when compared with male surgeons at 365 days (351.7 vs. 342.1 days; P < 0.001) and at each earlier time point. This remained consistent following adjustment for covariates, with patients of female surgeons experiencing a higher number of DAH at all time points, including at 365 days (343.2 [339.5-347.1] vs. 339.4 [335.9-343.0] days). Multivariable regression modeling revealed that patients of male surgeons had a significantly lower number of DAH versus female surgeons. Conclusions: Patients of female surgeons experienced a higher number of DAH when compared with those treated by male surgeons at all time points. More time spent at home after surgery may in turn lower costs of care, resource utilization, and potentially improve quality of life. Further studies are needed to examine these findings across other care contexts.

Intestinal serotonergic vagal signaling as a mediator of microbiota-induced hypertension.

Hypertension is a pervasive global health challenge, impacting over a billion individuals worldwide. Despite strides in therapeutic strategies, a significant proportion of patients remain resistant to the currently available therapies. While conventional treatments predominantly focus on cardiac, renal, and cerebral targets, emerging research underscores the pivotal role of the gut and its microbiota. Yet, the precise mechanisms governing interactions between the gut microbiota and the host blood pressure remain unclear. Here we describe a neural host-microbiota interaction that is mediated by the intestinal serotonin (5-HT) signaling via vagal 5HT3a receptors and which is crucial for maintenance of blood pressure homeostasis. Notably, a marked decrease in both intestinal 5-HT and vagal 5HT3aR signaling is observed in hypertensive rats, and in rats subjected to fecal microbiota transplantation from hypertensive rats. Leveraging an intersectional genetic strategy in a Cre rat line, we demonstrate that intestinal 5HT3aR vagal signaling is a crucial link between the gut microbiota and blood pressure homeostasis and that recovery of 5-HT signaling in colon innervating vagal neurons can alleviate hypertension. This paradigm-shifting finding enhances our comprehension of hypertensive pathophysiology and unveils a promising new therapeutic target for combating resistant hypertension associated with gut dysbiosis.

A Comprehensive Atlas of AAV Tropism in the Mouse.

Gene therapy with Adeno-Associated Viral (AAV) vectors requires knowledge of their tropism within the body. Here we analyze the tropism of ten naturally occurring AAV serotypes (AAV3B, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAVrh8, AAVrh10 and AAVrh74) following systemic delivery into male and female mice. A transgene expressing ZsGreen and Cre recombinase was used to identify transduction in a cell-dependent manner based on fluorescence. Cre-driven activation of tdTomato fluorescence offered superior sensitivity for transduced cells. All serotypes except AAV3B and AAV4 had high liver tropism. Fluorescence activation revealed transduction of unexpected tissues, including adrenals, testes and ovaries. Rare transduced cells within tissues were also readily visualized. Biodistribution of AAV genomes correlated with fluorescence, except in immune tissues. AAV4 was found to have a pan-endothelial tropism while also targeting pancreatic beta cells. This public resource enables selection of the best AAV serotypes for basic science and preclinical applications in mice.

Proximity-Unlocked Luminescence by Sequential Enzymatic Reactions from Antibody and Antibody/Aptamer (PULSERAA): A Platform for Detection and Visualization of Virus-Containing Spots.

The SARS-CoV-2 pandemic has challenged more scientists to detect viruses and to visualize virus-containing spots for diagnosis and infection control; however, detection principles of commercially available technologies are not optimal for visualization. Here, a convenient and universal homogeneous detection platform named proximity-unlocked luminescence by sequential enzymatic reactions from antibody and antibody/aptamer (PULSERAA) is developed. This is designed so that the signal appears only when the donor and acceptor are in proximity on the viral surface. PULSERAA specifically detected in the range of 25-500 digital copies/mL of inactivated SARS-CoV-2 after simply mixing reagents; it is elucidated that the accumulation of chemical species in a limited space of the viral surface contributed to such high sensitivity. PULSERAA was quickly adapated to detect another virus variant, inactivated influenza A virus, and infectious SARS-CoV-2 in a clinical sample. Furthermore, on-site (direct, rapid, and portable) visualization of the inactivated SARS-CoV-2-containing spots by a conventional smartphone camera was achieved, demonstrating that PULSERAA can be a practical tool for preventing the next pandemic in the future.

A novel pathogenic germline chromosome 3 inversion in von Hippel-Lindau disease.

von Hippel-Lindau (VHL) is an autosomal-dominant hereditary tumour susceptibility disease associated with pathogenic germline variants in the VHL tumour suppressor gene. VHL patients are at increased risk of developing multiple benign and malignant tumours. Current CLIA-based genetic tests demonstrate a very high detection rate of germline VHL variants in patients with clinical manifestations of VHL. In this report, we describe a large family with canonical VHL manifestations, for which no germline alteration had been detected by conventional germline testing. We identified a novel 291 kb chromosomal inversion involving chromosome 3p in affected family members. This inversion disrupts the VHL gene between exon 2 and exon 3 and is thereby responsible for the disease observed in this family.

Neoadjuvant immunotherapy for dMMR and pMMR colorectal cancers: therapeutic strategies and putative biomarkers of response.

Approximately 15% of locally advanced colorectal cancers (CRC) have DNA mismatch repair deficiency (dMMR), resulting in high microsatellite instability and a high tumour mutational burden. These cancers are frequently sensitive to therapy with immune-checkpoint inhibitors (ICIs) in the metastatic setting. This sensitivity seems to be even more pronounced in locally advanced disease, and organ preservation has become a realistic aim in ongoing clinical trials involving patients with dMMR rectal cancer. By contrast, metastatic CRCs with proficient DNA mismatch repair (pMMR) are generally resistant to ICIs, although a proportion of locally advanced pMMR tumours seem to have a high degree of sensitivity to ICIs. In this Review, we describe the current and emerging clinical evidence supporting the use of neoadjuvant ICIs in patients with dMMR and pMMR CRC, and the potential advantages (based on a biological rationale) of such an approach. We discuss how neoadjuvant 'window-of-opportunity' trials are being leveraged to progress biomarker discovery and we provide an overview of potential predictive biomarkers of response to ICIs, exploring the challenges faced when evaluating such biomarkers in biopsy-derived samples. Lastly, we describe how these discoveries might be used to drive a rational approach to trialling novel immunotherapeutic strategies in patients with pMMR CRC, with the ultimate aim of disease eradication and the generation of long-term immunosurveillance.

Molecular Hallmarks of Prostate-specific Membrane Antigen in Treatment-naïve Prostate Cancer.

BACKGROUND AND OBJECTIVE: We characterized tumor prostate-specific membrane antigen (PSMA) levels as a reflection of cancer biology and treatment sensitivities for treatment-naïve prostate cancer. METHODS: We first correlated PSMA positron emission tomography (PET) maximum standardized uptake values (SUVmax) in primary prostate cancer with tumor FOLH1 (PSMA RNA abundance) to establish RNA as a proxy (n = 55). We then discovered and validated molecular pathways associated with PSMA RNA levels in two large primary tumor cohorts. We validated those associations in independent cohorts (18 total; 5684 tumor samples) to characterize the pathways and treatment responses associated with PSMA. KEY FINDINGS AND LIMITATIONS: PSMA RNA abundance correlates moderately with SUVmax (ρ = 0.41). In independent cohorts, androgen receptor signaling is more active in tumors with high PSMA. Accordingly, patients with high PSMA tumors experienced longer cancer-specific survival when managed with androgen deprivation therapy for biochemical recurrence (adjusted hazard ratio [AHR] 0.54 [0.34-0.87]; n = 174). PSMA low tumors possess molecular markers of resistance to radiotherapy. Consistent with this, patients with high PSMA tumors experience longer time to recurrence following primary radiotherapy (AHR 0.50 [0.28-0.90]; n = 248). In the SAKK09/10 trial (n = 224), patients with high PSMA tumors who were managed with salvage radiotherapy experienced longer time to progression in the 64-Gy arm (restricted mean survival time [RMST] +7.60 [0.05-15.16]), but this effect was mitigated in the 70-Gy arm (RMST 3.52 [-3.30 to 10.33]). Limitations include using PSMA RNA as a surrogate for PET SUVmax. CONCLUSIONS AND CLINICAL IMPLICATIONS: PSMA levels in treatment-naïve prostate cancer differentiate tumor biology and treatment susceptibilities. These results warrant validation using PET metrics to substantiate management decisions based on imaging.

Structural basis of Pseudomonas aeruginosa penicillin binding protein 3 inhibition by the siderophore-antibiotic cefiderocol.

The breakthrough cephalosporin cefiderocol, approved for clinical use in 2019, has activity against many Gram-negative bacteria. The catechol group of cefiderocol enables it to efficiently enter bacterial cells via the iron/siderophore transport system thereby reducing resistance due to porin channel mutations and efflux pump upregulation. Limited information is reported regarding the binding of cefiderocol to its key proposed target, the transpeptidase penicillin binding protein 3 (PBP3). We report studies on the reaction of cefiderocol and the related cephalosporins ceftazidime and cefepime with Pseudomonas aeruginosa PBP3, including inhibition measurements, protein observed mass spectrometry, and X-ray crystallography. The three cephalosporins form analogous 3-exomethylene products with P. aeruginosa PBP3 following elimination of the C3' side chain. pIC50 and k inact/K i measurements with isolated PBP3 imply ceftazidime and cefiderocol react less efficiently than cefepime and, in particular, meropenem with P. aeruginosa PBP3. Crystal structures inform on conserved and different interactions involved in binding of the three cephalosporins and meropenem to P. aeruginosa PBP3. The results will aid development of cephalosporins with improved PBP3 inhibition properties.

Hepatic steatosis: Qualitative and quantitative sonographic assessment in comparison to histology.

Introduction: Globally, B-mode ultrasound is the most common modality used for the diagnosis of hepatic steatosis. We aimed to assess the correlation between qualitative liver ultrasound parameters, attenuation imaging (ATI) and histopathology-diagnosed steatosis grade obtained from liver biopsy. Our secondary aim was to examine the interobserver variability of qualitative ultrasound features. Methods: A retrospective cohort study was performed which included adult patients (age ≥ 18 years) who had same-day liver ultrasound, ATI and liver biopsy for grading hepatic steatosis severity between 2018 and 2022. The qualitative US features for hepatic steatosis were independently scored by three radiologists and interobserver variability was examined. Histologic steatosis grade, ATI and qualitative ultrasound parameters were compared. Results: Ninety patients were included; 67% female with a median age of 54 (IQR 39-65) years. The radiologist's overall impression had the highest correlation (very strongly correlated) with histologic steatosis grade (r = 0.82, P < 0.001). ATI coefficient and all qualitative ultrasound B-mode features except for liver echotexture and focal fat sparing were strongly correlated with histologic steatosis grade (r ≥ 0.70, P < 0.001). Most qualitative ultrasound features had good agreement between observers (Kappa statistic 0.61-1.0, P < 0.001), (Kendall coefficient 0.92, P < 0.001). Conclusion: The examined qualitative ultrasound parameters and ATI had good-excellent performance for diagnosing clinically significant hepatic steatosis; however, the radiologist's overall impression had the best correlation with histologic steatosis grade. Our findings suggest an ongoing role for qualitative liver ultrasound assessment of hepatic steatosis despite the emergence of newer quantitative measures.

Efficacy and safety of filgotinib in patients with moderately active rheumatoid arthritis and an inadequate response to methotrexate.

OBJECTIVES: Clinical trials restricted to moderately active RA are limited. Filgotinib is approved for treating moderate to severe active RA. This post hoc analysis assessed efficacy and safety of filgotinib in moderately active RA. METHODS: In FINCH 1, patients with active moderate to severe RA and inadequate response to methotrexate received filgotinib 200 mg or 100 mg (FIL200/FIL100) once daily, adalimumab 40 mg every 2 weeks, or placebo, all with methotrexate (n = 1,755). This subgroup analysis was conducted in patients with a moderate baseline Disease Activity Score in 28 joints using C-reactive protein (DAS28-CRP; >3.2 to ≤ 5.1; n = 425 [24.2%]). RESULTS: A higher proportion of patients achieved DAS28-CRP <2.6, Clinical Disease Activity Index (CDAI) remission (≤2.8), low disease activity (LDA) (DAS28-CRP ≤3.2 or CDAI ≤10), and American College of Rheumatology (ACR20/50/70) responses with FIL200 and FIL100 vs placebo at Weeks 12 and 24. Week 12 ACR20 response rates (primary end point) were 77.9%, 67.8%, and 43.8%, respectively. ∼75% of patients achieved DAS28-CRP LDA by week 24 with either filgotinib dose. FIL200 and FIL100 elicited greater improvements in patient-reported outcomes than placebo. The efficacy of filgotinib, maintained through week 52, was comparable to that of adalimumab. Frequency of adverse events (AEs) was similar with filgotinib and adalimumab. Infections were the most common AEs; incidence rates were 40-53% in active treatment groups. CONCLUSION: In this subpopulation with moderately active RA, the efficacy and safety of filgotinib were similar to those in the overall FINCH 1 population (patients with active moderate to severe RA). TRIAL REGISTRATION: NCT02889796.

Automated annotation of scientific texts for ML-based keyphrase extraction and validation.

Advanced omics technologies and facilities generate a wealth of valuable data daily; however, the data often lack the essential metadata required for researchers to find, curate, and search them effectively. The lack of metadata poses a significant challenge in the utilization of these data sets. Machine learning (ML)-based metadata extraction techniques have emerged as a potentially viable approach to automatically annotating scientific data sets with the metadata necessary for enabling effective search. Text labeling, usually performed manually, plays a crucial role in validating machine-extracted metadata. However, manual labeling is time-consuming and not always feasible; thus, there is a need to develop automated text labeling techniques in order to accelerate the process of scientific innovation. This need is particularly urgent in fields such as environmental genomics and microbiome science, which have historically received less attention in terms of metadata curation and creation of gold-standard text mining data sets. In this paper, we present two novel automated text labeling approaches for the validation of ML-generated metadata for unlabeled texts, with specific applications in environmental genomics. Our techniques show the potential of two new ways to leverage existing information that is only available for select documents within a corpus to validate ML models, which can then be used to describe the remaining documents in the corpus. The first technique exploits relationships between different types of data sources related to the same research study, such as publications and proposals. The second technique takes advantage of domain-specific controlled vocabularies or ontologies. In this paper, we detail applying these approaches in the context of environmental genomics research for ML-generated metadata validation. Our results show that the proposed label assignment approaches can generate both generic and highly specific text labels for the unlabeled texts, with up to 44% of the labels matching with those suggested by a ML keyword extraction algorithm.

Regenerating Family Member 3 Alpha Is Predictive of Mortality Following Emergent Large Vessel Occlusion.

Regenerating Family Member 3 Alpha (REG3A) is an antimicrobial protein secreted by the intestine and pancreas with additional immunomodulatory properties. Previously, we published that REG3A expression in ischemic stroke patient systemic blood, during mechanical thrombectomy (MT), is significantly associated with inflammatory cytokines and patient function on admission. This paper, however, did not investigate post-acute death rates. Therefore, we investigated plasma REG3A protein expression, during MT, in patients (n = 141) that survived or died within the end of the follow-up after MT. Subjects who died had significantly higher systemic plasma REG3A levels at the time of MT compared to survivors (p = 0.001). Age, sex, time from last known normal, and admission NIHSS were included as predictors to control for confounding variables and were all examined to determine their association in patient mortality. Logistic regression was used to demonstrate that higher odds of death were associated with increased REG3A levels (p = 0.002). REG3A demonstrated acceptable discrimination (AUC (95% CI): 0.669 (0.566-0.772) in predicting mortality. The overall model with age, sex, time from last known normal, and admission NIHSS discriminated well between survivors and those who died (AUC (95% CI): 0.784 (0.703-0.864)). In conclusion, REG3A could be promising as a biomarker to prognosticate stroke outcomes and stratify high-risk groups following acute ischemic stroke.

Novel Autotaxin Inhibitor ATX-1d Significantly Enhances Potency of Paclitaxel-An In Silico and In Vitro Study.

The development of drug resistance in cancer cells poses a significant challenge for treatment, with nearly 90% of cancer-related deaths attributed to it. Over 50% of ovarian cancer patients and 30-40% of breast cancer patients exhibit resistance to therapies such as Taxol. Previous literature has shown that cytotoxic cancer therapies and ionizing radiation damage tumors, prompting cancer cells to exploit the autotaxin (ATX)-lysophosphatidic acid (LPA)-lysophosphatidic acid receptor (LPAR) signaling axis to enhance survival pathways, thus reducing treatment efficacy. Therefore, targeting this signaling axis has become a crucial strategy to overcome some forms of cancer resistance. Addressing this challenge, we identified and assessed ATX-1d, a novel compound targeting ATX, through computational methods and in vitro assays. ATX-1d exhibited an IC50 of 1.8 ± 0.3 µM for ATX inhibition and demonstrated a significant binding affinity for ATX, as confirmed by MM-GBSA, QM/MM-GBSA, and SAPT in silico methods. ATX-1d significantly amplified the potency of paclitaxel, increasing its effectiveness tenfold in 4T1 murine breast carcinoma cells and fourfold in A375 human melanoma cells without inducing cytotoxic effects as a single agent.

Rapid affinity optimization of an anti-TREM2 clinical lead antibody by cross-lineage immune repertoire mining.

We describe a process for rapid antibody affinity optimization by repertoire mining to identify clones across B cell clonal lineages based on convergent immune responses where antigen-specific clones with the same heavy (VH) and light chain germline segment pairs, or parallel lineages, bind a single epitope on the antigen. We use this convergence framework to mine unique and distinct VH lineages from rat anti-triggering receptor on myeloid cells 2 (TREM2) antibody repertoire datasets with high diversity in the third complementarity-determining loop region (CDR H3) to further affinity-optimize a high-affinity agonistic anti-TREM2 antibody while retaining critical functional properties. Structural analyses confirm a nearly identical binding mode of anti-TREM2 variants with subtle but significant structural differences in the binding interface. Parallel lineage repertoire mining is uniquely tailored to rationally explore the large CDR H3 sequence space in antibody repertoires and can be easily and generally applied to antibodies discovered in vivo.

Computer-aided drug design to generate a unique antibiotic family.

The World Health Organization has identified antibiotic resistance as one of the three greatest threats to human health. The need for antibiotics is a pressing matter that requires immediate attention. Here, computer-aided drug design is used to develop a structurally unique antibiotic family targeting holo-acyl carrier protein synthase (AcpS). AcpS is a highly conserved enzyme essential for bacterial survival that catalyzes the first step in lipid synthesis. To the best of our knowledge, there are no current antibiotics targeting AcpS making this drug development program of high interest. We synthesize a library of > 700 novel compounds targeting AcpS, from which 33 inhibit bacterial growth in vitro at ≤ 2 µg/mL. We demonstrate that compounds from this class have stand-alone activity against a broad spectrum of Gram-positive organisms and synergize with colistin to enable coverage of Gram-negative species. We demonstrate efficacy against clinically relevant multi-drug resistant strains in vitro and in animal models of infection in vivo including a difficult-to-treat ischemic infection exemplified by diabetic foot ulcer infections in humans. This antibiotic family could form the basis for several multi-drug-resistant antimicrobial programs.

Early Inflammation and Interferon Signaling Direct Enhanced Intestinal Crypt Regeneration after Proton FLASH Radiotherapy.

Ultra-high dose rate ("FLASH") radiotherapy (>40-60 Gy/s) is a promising new radiation modality currently in human clinical trials. Previous studies showed that FLASH proton radiotherapy (FR) improves toxicity of normal tissues compared to standard proton radiotherapy (SR) without compromising anti-tumor effects. Understanding this normal tissue sparing effect may offer insight into how toxicities from cancer therapy can be improved. Here, we show that compared to SR, FR resulted in improved acute weight recovery and survival in mice after whole-abdomen irradiation. Improved morbidity and mortality after FR were associated with greater proliferation of damage-induced epithelial progenitor cells followed by improved tissue regeneration. FR led to the accelerated differentiation of revival stem cells (revSCs), a rare damage-induced stem cell required for intestinal regeneration, and to qualitative and quantitative changes in activity of signaling pathways important for revSC differentiation and epithelial regeneration. Specifically, FR resulted in greater infiltration of macrophages producing TGF-ß, a cytokine important for revSC induction, that was coupled to augmented TGF-ß signaling in revSCs. In pericryptal fibroblasts, FR resulted in greater type I IFN (IFN-I) signaling, which directly stimulates production of FGF growth factors supporting revSC proliferation. Accordingly, the ability of FR to improve epithelial regeneration and morbidity was dependent on IFN-I signaling. In the context of SR, however, IFN-I had a detrimental effect and promoted toxicity. Thus, a tissue-level signaling network coordinated by differences in IFN-I signaling and involving stromal cells, immune cells, and revSCs underlies the ability of FLASH to improve normal tissue toxicity without compromising anti-tumor efficacy.