Organophosphate esters (OPEs) are found ubiquitously in the environment and exposure to these chemicals has induced behavioral, developmental, and morphological impairments in several model organisms. Yet there is still a lack of understanding of how sub-lethal exposure disrupts organism function at the molecular-level, especially for Daphnia magna. To address this knowledge gap, D. magna responses after exposure to three sub-lethal concentrations consisting of 23.5 mg/L, 59 mg/L, and 118 mg/L for tris(2-chloroethyl) phosphate (TCEP); 2.5 mg/L, 6.25 mg/L, and 12.5 mg/L for tris(2-chloro-1-methylethyl) phosphate (TCPP); 0.125 mg/L, 0.312 mg/L, and 0.625 mg/L for triphenyl phosphate (TPhP) were examined. These OPEs were selected as they are frequently detected in aquatic ecosystems. Targeted mass spectrometry metabolomics was used to measure the molecular-level regulation of key metabolites after 48 h of exposure. Metabolomics technologies can capture changes of metabolite levels in model organisms exposed to sub-lethal concentrations where key metabolic pathways responsible for vital biological functions can be elucidated. Metabolic perturbations in amino acid levels were observed after exposure to OPEs with higher octanol-water partition coefficients (TCPP and TPhP). In addition to the perturbed metabolites shared across all tested OPEs, each OPE resulted in unique perturbations to select metabolites. Most metabolite concentrations exhibited non-monotonic responses following exposure to TCEP and TPhP. In contrast, after TCPP exposure, both non-monotonic and monotonic responses were observed across the measured metabolites. This study distinguishes specific metabolic disturbances that are unique to the side chains attached to the phosphate center when exposed to D. magna. Hence, these metabolites are most sensitive to OPE sub-lethal exposure. Providing novel insights into the diverse modes of action from sub-lethal OPE exposure to a sentinel species allows for more effective risk assessment and water monitoring strategies to be implemented for the protection of freshwater ecosystems.
Exposure to blast overpressures in the line of duty causes many service members and veterans to suffer inner ear injuries and the resulting hearing disabilities. The response to blast waves within the cochlea, particularly by the sensory hair cells within the organ of Corti (OC), is challenging to measure experimentally. Recently, 3D finite element (FE) models of the human ear at macroscale and OC models at microscale have been established to examine the blast transmission throughout the ear and the OC response at the middle turn of the basilar membrane (BM). This multiscale model was lacking OC models at other locations along the BM, which would allow the investigation of OC behavior and distribution of injury throughout the cochlea. Microscale FE models of the OC were developed representing the basal, middle, and apical turns of cochlea, located 4.25, 16.8, and 29.3 mm from the base of the BM. Each model contained the comprehensive biostructures of membranes, sensory hair cells, and supporting cells, with changes in their dimensions and localized material properties. BM displacements caused by transmission of a 30 kPa blast overpressure were derived from the macroscale ear model and applied as input to the BM in each OC model. The simulations were run for 2 ms with a 1 μs time step. The displacements, stresses, and strains on each component were tracked. The stress on the sensory outer hair cells (OHCs) and the strain at the connection between the tectorial membrane (TcM) and stereociliary hair bundles (HBs) were used as the primary metrics that could indicate injury to the OC. The basal turn OC model reported the highest stress on the OHCs, with a maximum von Mises stress of 0.84 kPa. OHC stress is associated with hair cell apoptosis, and documented hair cell loss because of blast exposure is concentrated in the basal turn of the cochlea. The model-derived results align with these observations. The strain on the TcM was most severe on its connections to HBs, with the highest maximum strain reported occurring in the middle turn OC model. This strain may indicate the decoupling of stereocilia from the TcM without hair cell death, which is an inner ear injury unique to blast-damaged cochleae. Three microscale FE models of the OC were developed and provided detailed information about the blast-induced inner ear biomechanical behavior. The stress on the OHCs and strain at the connection between the TcM and HBs were used to predict the likelihood of injury, which appeared most likely in the basal and middle turns of the cochlea. This study represents an important step towards a comprehensive and accurate model of the human ear.
Microplastic contamination of biological matrices is a pressing concern in environmental and biomedical research. While their presence has been confirmed in human blood, placentas, lungs, and other tissues, accurate identification remains an analytical challenge. Obstacles include the small size and heterogeneous composition of microplastics, as well as spectral interference from complex organic matter. This review systematically analyzes-following PRISMA 2020 guidelines-the current state of microplastic detection in human tissues, evaluating 218 studies (2000-2024). We focus on the primary techniques: Fourier Transform Infrared (FTIR) and Raman spectroscopy, and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS). Our analysis confirms FTIR as the most widely employed technique, followed by Raman and Py-GC/MS, with each method exhibiting distinct advantages and limitations in sensitivity, specificity, and sample preparation requirements. A critical finding is the widespread lack of robust quality assurance; notably, few studies consistently implemented blank controls and spike-recovery experiments, thereby compromising the reproducibility and reliability of data. In response, we propose a consolidated framework of best practices for sample handling, contamination control, and analytical validation. This review underscores the urgent need for standardized, validated protocols to refine analytical techniques, ensure consistent results, and ultimately support accurate risk assessment of human exposure to microplastics.
A central challenge in systemic sclerosis (SSc) is the inability to distinguish active, potentially reversible disease, from damage, irreversible fibrosis. Current imaging modalities, including high-resolution computed tomography (HRCT) and echocardiography, predominantly capture structural damage and cannot resolve this distinction. This review outlines next generation imaging modalities for SSc with focus on quantitative machine learning algorithms and molecular imaging. The unifying advance across organ systems is a shift from documenting damage to measuring disease activity directly. Machine-learning-derived quantitative HRCT detects radiological patterns of ILD sensitive to change in SSc-associated interstitial lung disease. Parametric cardiac magnetic resonance mapping resolves diffuse interstitial fibrosis missed by late gadolinium enhancement. Fibroblast activation protein inhibitor PET (FAPI-PET) visualizes active fibrogenesis in lung and myocardium, identifying biologically active disease even before structural distortion occurs. [18F]Sodium fluoride PET detects metabolically active calcinosis. High-frequency ultrasound, elastography, and optical coherence tomography (OCT)-angiography extend objective assessment of cutaneous and microvascular involvement. Emerging imaging modalities in SSc may enable earlier detection of active disease amenable to treatment modification and yield more sensitive endpoints for SSc clinical trials.
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Anthyllis henoniana leaves and flowers were subjected to fractionated extraction using cyclohexane (CYHA), dichloromethane (DCM), ethyl acetate (EtOAc) and methanol (MeOH). The leaves-MeOH extract showed the highest yield and total polyphenol contents (TPC) compared to the flowers. The strongest antiradical activity (IC50 = 7.7 µg/mL) was recorded for the leaves compared to flowers (>50 µg/mL). The HPLC-DAD analysis showed the presence of eight and twelve bioactive compounds in the leaf and flower extracts, respectively. The flowers-CYHA extract exhibited the best anti-5-lipoxygenase (anti-5-LOX) activity (IC50 = 15 µg/mL) compared to the leaves (IC50 = 42 to 47 µg/mL). Anthyllis henoniana leaves showed greater anti-acetylcholinesterase (anti-AChE) activity than the flowers. The leaves-DCM fraction induced 60 and 70% cell growth inhibition against MCF-7 and HCT-116, respectively. Furthermore, the molecular docking investigations supported the in vitro antioxidant and anti-5-LOX patterns, revealing that the identified compounds exhibited low binding energies and interacted effectively within the novel human peroxidase (PDB:1PRX) and the crystal structure of soybean lipoxygenase-B (PDB: 2IUJ) enzymes, respectively. The obtained results indicated that the leaves-MeOH extract was the most enriched in polar compounds with high antioxidant and cytotoxic capacities, whereas the flowers-CYHA extracts accumulated nonpolar compounds of an effective anti-inflammatory capacity.
Since its isolation from a Yellowstone hot spring in 1972, Sulfolobus acidocaldarius has become one of the most important model organisms for archaeal biology. Initially studied for its remarkable adaptation to high temperature and low pH, it has evolved into a genetically tractable system that has contributed substantially to our understanding of archaeal physiology, molecular biology, and evolution. Here, we summarize more than 5 decades of research on S. acidocaldarius, highlighting key developments in genetic and microscopy tools and their impact on our understanding of archaeal cell biology. Studies in this organism have improved our understanding of archaeal metabolism, chromosome organization, DNA replication and segregation, cell division, protein glycosylation, biofilm formation, and the assembly and regulation of archaeal surface structures, including archaella and type IV pili. Beyond fundamental biology, S. acidocaldarius has also served as a valuable source of thermostable enzymes and other biomolecules with biotechnological potential. Today, S. acidocaldarius is still one of the main model organisms for archaeal biology. Ongoing advances in genetics, imaging, and structural biology continue to expand its experimental potential, while its phylogenetic position within the Thermoproteota makes it a powerful system for investigating the evolutionary origins of eukaryotic cellular complexity.
Tomato (Solanum lycopersicum L.) is a globally significant crop valued for its nutritional content and economic importance. This study evaluated the effect of individual and combined inoculation of two growth-promoting microorganisms in tomato: the entomopathogenic fungus Beauveria bassiana and the arbuscular mycorrhizal fungus Rhizophagus irregularis. The research was conducted in chamber conditions using tomato plants cultivar Elpida, at two developmental stages: seedlings and transplanted plants. Colonization of B. bassiana in plant tissues was confirmed by isolation from different organs, showing a higher presence in stems. mycorrhizal colonization was evident in roots, with the highest intensity in coinoculation treatments, which also showed greater formation of structures typical of symbiosis. Regarding growth, B. bassiana promoted greater leaf number and shoot biomass in seedlings, while R. irregularis favored root development, which is important for adaptation after transplanting. Coinoculation resulted in a significant increase in leaf area and mycorrhizal colonization, especially after transplanting, suggesting that the combination of these microorganisms can enhance the growth of tomato plants. The results indicate that early inoculation with B. bassiana and R. irregularis can be an effective strategy to improve plant development, although additional studies are required to evaluate long-term effects and final yield.
This observational autopsy-based case series characterized the tissue distribution of Histoplasma capsulatum in deceased people living with HIV (PLHIV) using minimally invasive tissue sampling (MITS). This study included 59 deceased PLHIV admitted to a tertiary referral hospital in the Brazilian Amazon between October 2020 and June 2022. Tissue and body fluid samples were analyzed using fungal culture, histopathology, conventional polymerase chain reaction (PCR), and quantitative PCR (qPCR). H. capsulatum was detected in 27 of 59 (45.8%) patients, including nine (33.3%) with multi-organ detection of H. capsulatum. The liver (9/27, 33.3%) and lungs (8/27, 29.6%) were the most frequently involved organs in this series. qPCR amplification was detected across multiple tissues, with lower median Ct values in the lung (40.3, range 37.0-45.0) and liver (41.0, range 38.0-44.0) than in cerebrospinal fluid (43.5, range 40.0-48.0) and brain tissue (44.0, range 41.0-47.0), suggesting greater fungal DNA detection in the lungs and liver. Molecular methods detected fungal DNA in tissue samples that were negative by culture, although several amplification signals occurred near the assay detection limit. H. capsulatum showed heterogeneous tissue distribution in deceased PLHIV, with the liver and lungs being the most frequently involved organs. Molecular methods complemented conventional diagnostic techniques by identifying fungal DNA in culture-negative tissues, providing a more comprehensive assessment of tissue involvement. These findings improve understanding of disseminated histoplasmosis in advanced HIV infection and may inform future tissue-based diagnostic strategies.
Sepsis and septic shock require a standardized, time-critical approach: screening of acutely ill high-risk patients, prompt assessment of infection and sepsis-associated organ dysfunction, rapid initiation of appropriate intravenous antimicrobials, and early hemodynamic stabilization. Key elements include obtaining blood cultures before antimicrobials, balanced crystalloids as first-line fluids, norepinephrine as the main vasopressor, and-if vasopressor requirements persist-adjunctive strategies such as vasopressin or hydrocortisone ± fludrocortisone depending on the clinical scenario. Prevention (infection prevention, antibiotic stewardship (ABS)/antimicrobial stewardship (AMS) programs) and structured follow-up aim to reduce long-term sequelae after sepsis. Sepsis und septischer Schock erfordern ein standardisiertes, zeitkritisches Vorgehen: Screening akuter Hochrisikopatient*innen, zügige Diagnostik der Infektion und der sepsisassoziierten Organdysfunktion, rascher Beginn einer adäquaten antiinfektiven Therapie sowie frühe hämodynamische Stabilisierung. Kernelemente sind u. a. Blutkulturen vor Antiinfektiva, balancierte Kristalloide als initiale Flüssigkeitstherapie, Noradrenalin als zentraler Vasopressor und – bei persistierendem Bedarf – additive Strategien (z. B. Vasopressin, Hydrokortison ± Fludrokortison) nach klinischem Kontext. Prävention (Infektionsprävention, Antibiotic-Stewardship(ABS)- bzw. Antimicrobial-Stewardship(AMS)-Programme) und strukturierte Nachsorge adressieren Langzeitfolgen nach Sepsis.
Near-infrared-II (1000-1700 nm) photoacoustic imaging enables deep-tissue visualization with high spatial precision but lacks organic probes integrating general design, reduced molecular complexity, and high-fidelity in vivo signal output. Herein, we present a general building-block design for ultralow-molecular-weight "zero-on" near-infrared-II photoacoustic dyes for in vivo high-fidelity imaging. Constructed around a dimethyl-dihydroacridine scaffold and synthesized in three steps, these dyes incorporate biomarker-responsive blocks for targeted activation and absorption-expanded blocks for near-infrared-II absorption tuning, while maintaining a molecular weight <500 Da. This general building-block design enables tailored applications. Ultralow molecular weight improves solubility, tissue penetration and clearance. Notably, biomarker activation drives nonconjugated-to-conjugated structural transition, inducing >700 nm absorption redshift and boosting near-infrared-II photoacoustic signals at 1064 nm from levels statistically indistinguishable from water (p > 0.05, defining "zero" probe background) to an 89.8-fold enhancement in "on" state. "Zero" background minimizes false positives from misinterpreting probe background accumulation signals in diseased tissues as biomarker activation, even in high-uptake organs like the liver. In a blinded study, our "zero-on" probes identified early‑stage hepatotoxicity in mice with 100% accuracy, outperforming 85% accuracy of traditional non-zero background "off-on" probes. This work enables a general design to achieve ultralow-molecular-weight near-infrared-II photoacoustic dyes for high-fidelity signal output in vivo.
Complex chemical mixtures are ubiquitous in aquatic environments posing substantial risks to aquatic organisms and human health, and the prediction of their combined toxicity is the key measure to control their ecological risks. This, however, still remains a major challenge for the two widely used classic standard additive models, concentration addition (CA) and independent action (IA), due to complex interactions, antagonism or synergism, within mixtures. Therefore, to conquer the dilemma, a novel interpretable machine learning model was constructed by integrating the predicted values by CA and IA with molecular descriptors (CIMM) against a freshwater organism Chlorella pyrenoidosa to predict the combined toxicity of complex mixture pollutants. The CIMM model stability was assessed by repeated modeling with ten random seeds, and its interpretability was examined by using mutual information, partial dependence plots and SHAP values. A dual-metric applicability domain was established based on kernel density estimation and k-nearest neighbor distance, and generalization performance was evaluated on a completely independent external validation set. The results showed that the CIMM framework achieved a mean test-set R2 of 0.9080 ± 0.0127 across ten random-seed runs, which was implemented using the seed-specific optimal Random Forest or XGBoost algorithm. Compared to the results predicted by CA alone, CIMM increased R2 by 32.2% and the RMSE decreased by 46.4%, while to those predicted by model using only molecular descriptors, the R2 improved by approximately 8.87% and the RMSE decreased by 25.38%. CA and IA predictions were the key features of CIMM that drove the model output, and they exhibited stable monotonic positive relationships with mixture toxicity. The applicability domain assessment showed that in-domain samples achieved an external validation R2 of 0.768 which was markedly higher than 0.352 for out-of-domain samples, with lower prediction uncertainty for in-domain data. This study provides a high-accuracy, interpretable and applicability-domain-constrained framework for predicting the combined toxicity of complex mixture pollutants in aquatic environment, regardless of whether toxicity interactions occur within the mixtures.
Antibiotic resistance of Gram-positive bacteria poses a major clinical challenge. Daptomycin, a lipopeptide antibiotic, is a treatment option for drug-resistant organisms. However, there have been clinical reports of daptomycin resistance and in vitro reports of daptomycin tolerance that can result in treatment failure. Daptomycin possesses a fatty acid tail that inserts into the membrane, and membrane fatty acid content can influence its binding. Given that, we examined the potential of fatty acids to enhance daptomycin activity against enterococcal strains. We demonstrate that the saturated fatty acids myristic and palmitic acids increase bacterial susceptibility to the antibiotic, even for a daptomycin-resistant clinical isolate. These effects were highly specific with no impact on daptomycin susceptibility of Staphylococcus aureus. Growth of enterococci with myristic or palmitic acid reduced membrane fluidity, potentially promoting tighter daptomycin insertion. However, we noted no difference in membrane permeability for cells treated with fatty acids and daptomycin. While cells exposed to saturated fatty acids experience greater membrane depolarization, the lack of consistent, significant time-dependent changes upon daptomycin treatment suggests that depolarization alone does not fully explain the increased sensitivity. A strain that is unable to incorporate exogenous fatty acids into phospholipids was insensitive to the effects of saturated fatty acids on its susceptibility to daptomycin, highlighting the necessity of fatty acid incorporation onto lipid headgroups for potentiation. Overall, our data suggest that the incorporation of specific saturated fatty acids within the enterococcal membrane likely disrupts lipid composition, membrane organization and cellular envelope homeostasis, ultimately contributing to enhanced daptomycin susceptibility.
To investigate the association between occupational high-temperature exposure and accelerated biological aging. A total of 140 male workers exposed to occupational high-temperatures and 207 male non-exposed control workers were selected as study subjects. Questionnaire surveys and health examinations were conducted. Biological age and organ-specific biological age were calculated using the Klemera-Doubal method. Generalized linear models were used to analyze the effects of occupational high-temperature exposure, body mass index (BMI), smoking, alcohol consumption, and sleep duration on biological age (BA) acceleration and organ-specific biological age. Significant differences were observed between the exposed and control groups in length of service, systolic blood pressure, red blood cell count, albumin levels, urea, creatinine, BA acceleration, and liver-kidney BA acceleration ( P < 0.05). Compared with the control group, which showed a BA acceleration of 0.04 ± 1.34 years, the exposed group demonstrated significantly higher BA acceleration of 0.62 ± 1.31 years. After adjustment for covariates, workers exposed to high-temperatures exhibited significantly higher BA acceleration and liver-kidney BA acceleration than controls ( P < 0.001). High-temperature exposure and BMI were associated with BA acceleration, with a significant interaction between the two factors ( P < 0.05). High-temperature exposure, BMI, and smoking were identified as risk factors for BA acceleration, whereas sleep duration was a protective factor ( P < 0.05). Occupational high-temperature exposure may accelerate biological aging. An interaction exists between occupational high-temperature exposure and BMI in relation to BA acceleration. available in www.besjournal.com.
Sustaining wheat yield gains requires optimizing the spatiotemporal coordination of source (leaves), transport (stems), and sink (spikes) organs. However, the physiological mechanisms and underlying genetic networks orchestrating the dynamic development of these critical structures remain largely uncharacterized. Here, we leveraged high-resolution time-series phenotyping across 590 wheat accessions evaluated across three year-site environments (comprising two locations and two growing seasons) to dissect the genetic architecture of these biomass partitioning trajectories. To fully capture this spatiotemporal regulation, our analysis explicitly integrated both the temporal tracking across five floret developmental stages (Z39-Z65) and the spatial partitioning among these organ-specific dynamic systems. We identified 36 multi-stage stable dynamic quantitative trait loci (QTL) regulating five source-sink-related traits. By constructing genetic association and epistatic interaction networks, we prioritized two pivotal dynamic QTL, namely Qa.nw-7B.848 and Qa.nw-1D.96. Multi-omics integration pinpointed TraesCS7B03G1340600 as a key candidate gene for Qa.nw-7B.848. Furthermore, haplotype analysis uncovered distinct selection footprints, demonstrating how specific allelic combinations have been differentially selected to optimize yield components across diverse geographical environments. Collectively, this study moves beyond static trait analysis, offering a dynamic genetic framework and specific epistatic targets to precision-design wheat architecture for enhanced productivity.
Cancer affects over 1,000 active-duty military personnel annually, directly undermining force readiness. To address this challenge, the Department of Defense, Department of Veterans Affairs (VA), and the National Cancer Institute established the Applied Proteogenomics Organizational Learning and Outcomes (APOLLO) Consortium as part of the Cancer Moonshot Program. APOLLO collects standardized pathology data to advance research and clinical care, but integrating the College of American Pathologists (CAP) electronic Cancer Checklists (eCC) has traditionally been left to individual institutions and vendors, making implementation challenging. We developed eCC2Db, a software system that automates parsing of CAP eCC XML templates, generates Oracle database objects and metadata, and renders forms exactly as they appear on cap.org. The tool integrates with the Data Tracking System for APOLLO (DTS-APOLLO), enabling interactive completion of CAP eCC forms with data stored for audit tracking, reporting, and secure transfer to a centralized Data Warehouse. No human subjects or identifiable patient data were used. This research was conducted under the APOLLO protocol. Implementation of the tool eliminated manual database tables and relationship design, reduced transcription errors, and improved compliance with CAP standards although demonstrating scalability across CAP's semiannual updates. As of this writing, the system has implemented a total of 134 CAP eCC templates, including 17 biomarker templates. Among these, 117 organ templates, demonstrating broad coverage across cancer types. This level of implementation confirms that DTS-APOLLO can support nearly all CAP-defined cancer protocols, including complex biomarker forms, which are essential for precision oncology. By automating CAP eCC template management, DTS-APOLLO strengthens APOLLO's data infrastructure, enhances readiness, and produces AI-ready, CAP-compliant datasets that provide a foundation for predictive analytics, treatment decision support, and next-generation precision oncology research.
Fish cell lines are indispensable in vitro systems that support diverse research areas, including virology, immunology, ecotoxicology, and biomedical science. Fish represent the most species-rich vertebrate group with remarkable genomic diversity, providing valuable resources for specialised cellular models. Since the establishment of the first fish cell line (RTG-2) in 1962, the global repository has expanded to approximately 918 authenticated cell lines derived from over 211 species. This review presents a comprehensive overview of the historical progression, global repositories, and current standards for cell line authentication. It summarises methodological advances in primary culture initiation, the development of continuous cell lines, and improvements in cryopreservation techniques. This review also critically explains the wide-ranging applications of fish cell lines in aquatic virology, vaccine development, and standardised ecotoxicological assays. The translational potential in biomedical research is also highlighted, particularly in cancer biology, regenerative medicine, and drug discovery, largely driven by the use of genetically tractable model species such as zebrafish (Danio rerio) and medaka (Oryzias latipes). Key challenges are also discussed, including mycoplasma contamination, cross-species misidentification, limitations in cryopreservation protocols for marine-derived cells, and the need for robust, open-access digital biobanking systems. Future perspectives encompass emerging technologies such as 3D organoids, organ-on-a-chip platforms, CRISPR-based genome editing, and serum-free culture systems. Integration of these innovations with omics approaches and adverse outcome pathway frameworks is expected to enhance the utility of fish cell lines, advancing research in aquaculture, environmental monitoring, and food security, while aligning with the principles of the 3Rs and the United Nations Sustainable Development Goals.
Ricin, a potent protein toxin derived from Ricinus communis, is considered one of the most significant threats in cases of bioterrorism, homicide, suicide, and accidental acute poisoning. However, its clinical and pathological features in fatal cases have not been systematically summarized. This systematic review aimed to summarize the current evidence regarding the clinical manifestations, toxicological biomarkers, autopsy findings, and medico-legal aspects of fatal ricin poisoning. A comprehensive literature search was conducted in accordance with PRISMA guidelines. Original studies, case reports, and case series reporting detailed clinical, toxicological, or autopsy data following fatal or near-fatal human exposure to ricin were included in the review. The available evidence suggests a relatively consistent clinical course, characterized by rapid progression from mild, nonspecific gastrointestinal symptoms to hypovolemic shock, multi-organ failure, and refractory cardiovascular collapse. Ricinine was consistently detected in blood, urine, and postmortem tissues, supporting its role as a reliable biomarker of ricin exposure, although current evidence is insufficient to establish definitive correlations with poisoning severity or toxicokinetics. Reported autopsy findings commonly included hemolysis, hemorrhagic necrosis of the gastrointestinal tract, hepatic injury, renal tubular necrosis, and evidence supporting the presence of a capillary leak syndrome. Several specific medico-legal challenges emerged from the reviewed literature, including the need for the development of novel analytical methods with improved detection limits and quantification capabilities for ricinine, the interpretation of postmortem redistribution phenomena, the distinction between lethal and non-lethal exposures, and the differential diagnosis with other septic shock-like syndromes. Overall, the available evidence suggests a relatively consistent clinicopathological pattern associated with fatal ricin poisoning that can be corroborated through ricinine detection, while emphasizing the importance of early toxicological investigations, particularly when no history of exposure is available. These findings provide a concise and integrated body of evidence to support clinical management, inform forensic investigations, and enhance public health preparedness, while highlighting the need for standardized postmortem sampling protocols and further research into the toxicodynamics of ricin in humans.
Carbapenem-resistant Enterobacterales (CRE) are classified as carbapenemase- and non-carbapenemase-producing (non-CP) CRE. The purpose of this study was to identify factors associated with meropenem non-susceptible non-CP CRE to help stratify treatment approaches and to report rates of treatment-emergent resistance among patients with non-CP CRE bacteraemia. This was a retrospective, single-centre study of patients hospitalized between January 2015 and September 2025 with bacteraemia due to Enterobacterales resistant to ertapenem and confirmed to be non-CP. Ertapenem resistance was determined by broth microdilution susceptibility testing. Carbapenemase testing was performed by modified carbapenem-inactivation method, polymerase chain reaction or whole-genome sequencing. Among 60 patients who met the inclusion criteria, the median (IQR) age was 63 years (57-73), 33% (20/60) were female and 18% (11/60) were organ transplant recipients. Patients infected with meropenem non-susceptible non-CP CRE were more likely to have prior meropenem exposure [60% (10/15) versus 13% (8/45), P < 0.001] and have breakthrough bacteraemia [60% (9/15) versus 29% (13/45), P = 0.031]. Treatment-emergent resistance developed in 16% (4/24) and 0% (0/15) of patients treated with meropenem and ceftazidime-avibactam, respectively. These exploratory data provide new insights into clinical factors associated with meropenem non-susceptible non-CP CRE and support future investigations into the comparative-effectiveness of meropenem versus beta-lactam/beta-lactamase inhibitors for the treatment of meropenem-susceptible non-CP CRE.
Biosynthesis of the linear tetrapyrrole phycocyanobilin (PCB) by the ferredoxin-dependent bilin reductase (FDBR) PcyA is essential for light-harvesting and regulatory processes in diverse photosynthetic organisms, yet its evolutionary origins are not fully understood. PcyA evolved from pre-PcyA proteins found in diverse bacteria. Three lineages of pre-PcyA proteins were previously identified: Pre-1, Pre-2, and Pre-3. Using an in vivo co-expression assay, in this work, Pre-2 and Pre-3 proteins were shown to be active FDBRs that did not synthesize PCB, whereas Pre-1 activity was apparently low. In refining these results, we noted a discrepancy between phycoerythrobilin populations generated by Pre-3 and by the distantly related FDBR PebS. We therefore examined the properties of pre-PcyA enzymes in vitro, using an updated pre-PcyA phylogeny to select an alternative pre-1 target. Biochemical analyses revealed that Pre-1 and Pre-2 catalyze the two-electron reduction of biliverdin (BV) to 3E-phytochromobilin (3E-PФB), in contrast to the known synthesis of 3Z-phytobilins by other FDBRs. Pre-3 can also carry out an additional two-electron reduction to yield 3E-phycoerythrobilin (3E-PEB), again distinct from the 3Z-PEB produced by PebS. We then used comparative sequence and structure analysis to target candidate catalytic residues for site-directed mutagenesis. Variant Pre-1 exhibited altered product stereochemistry, but no effects on Pre-2 were observed, and Pre-3 variants unexpectedly gained the ability to bind cyclic tetrapyrroles. These findings underscore the plasticity and promiscuity of this enzyme family. Together, this work illustrates how the flexible catalytic potential of ancestral enzymes shaped the evolution and diversification of bilin biosynthetic pathways.