Toxins最新文献

Cell-based potency assays (CBPAs) are required for the potency testing and commercial release of botulinum neurotoxin (BoNT)-based drug products. These CBPAs must account for the toxin's biological activities while meeting regulatory guidelines for precision and accuracy. Here, studies describe the characterization and qualification of the BoSapient CBPA and demonstrate that it is fit for use as a relative potency assay for BoNT/A-containing samples. The CBPA is operated in a 96-well plate format and relies upon the fluorescence emissions of a reporter that directly responds to BoNT/A activity. The BoSapient cell line expresses the BoNT/A-receptors SV2 and complex gangliosides, is responsive only to intact BoNT/A, and can robustly detect picomolar and sub-picomolar BoNT/A quantities, making the CBPA appropriate for quantifying BoNT/A-based drug products. The cell line was passaged 30 times without significant loss of reporter expression or BoNT/A sensitivity. Manual and semi-automated CBPA methods were developed and qualified according to regulatory guidelines and shown to have low bias (<4% from expected) and high precision (standard deviation < 8) across all test concentrations. Furthermore, the semi-automated method using the CBPA is demonstrated to improve intermediate precision by 39% compared to the manual method, while reducing operator dependency during method execution.

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Plasticity is fundamental to the development, strengthening, and maintenance of healthy synaptic connections and recovery from injury in both the central and peripheral nervous systems. Yet, the processes involved are poorly understood. Herein, using a combination of patch-clamp electrophysiology and immuno-fluorescence confocal microscopy in adult mice, it is shown that blockade of synaptic transmission at submandibular ganglion junctions exposed to botulinum neurotoxin type A was accompanied by a rapid and striking decline in the abundance of synaptic vesicle markers-SV2, vesicle-associated membrane protein 2, and vesicular acetylcholine transporter-plus SNAP-25 (cleaved and intact) and postsynaptic α7 nicotinic acetylcholine receptors. Such alterations by the neurotoxin of parasympathetic synapses contrast starkly with the stability of postsynaptic proteins at nearby skeletal neuromuscular junctions. Both neurotransmission and the expression of SV2 and α7 nicotinic acetylcholine receptors remained depressed for 4 weeks, with full recovery of synaptic function delayed for more than 8 weeks. These novel findings may explain the relatively slow recovery of autonomic function after botulism or following therapeutic injections to alleviate hypersecretory disorders.

This study was focused on the assessment of fungal occurrence, mycotoxin dynamics, aflatoxin carry-over, and associated biochemical responses in dairy cattle. Moisture emerged as the dominant factor for fungal communities, promoting the co-proliferation of fungal genera adapted to high water activity conditions (a_w > 0.90) and antagonism against xerotolerant and xerophilic species. Aspergillus spp. dominated dry substrates (a_w < 0.75), Fusarium spp. showed strong positive associations with high-moisture matrices (a_w > 0.90), and Penicillium spp. exhibited intermediate, substrate-dependent behavior. Mycotoxin levels fluctuated non-linearly, independently of fungal counts: ochratoxin A (OTA) concentrations in corn silage increased from approximately 12 μg/kg at the onset of the ensiling period to >240 μg/kg at silo opening, indicating dynamic mycotoxin accumulation during storage, while zearalenone (ZEA) oscillated from 40 to 170 µg/kg. Despite the variation in total aflatoxins (AFLA-T) across feed matrices, aflatoxin M1 (AFM1) in milk remained low (0.0020-0.0093 μg/kg), confirming limited carry-over. Serum biochemical parameters-alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), total bilirubin (BIL-T), total protein (PROT-T)-remained within physiological limits, yet multivariate analyses revealed metabolic modulation linked to aflatoxin exposure. AFM1 explained >7% of the variance in serum biochemical profiles according to PERMANOVA (p = 0.002), showed significant MANOVA effect (Pillai = 0.198), and displayed a significant canonical association (p < 10^-13). Linear discriminant analysis further separated Normal vs. Borderline hepatic profiles, indicating subclinical physiological adaptation to chronic low-dose exposure.

Aflatoxin B1 (AFB1), deoxynivalenol (DON), and ochratoxin A (OTA) are common mycotoxins that frequently co-occur in cereals and pose potential risks to animal and human health. This study investigated the cytotoxic effects of AFB1, DON, and OTA, individually and in binary and ternary combinations, in four human-derived cell lines representing major target organs (Caco-2, HepG2, HK-2, and SK-N-SH). Individual toxin exposure revealed cell type-dependent sensitivity, with DON generally exhibiting the strongest cytostatic effect. Combined exposure analysis showed distinct interaction patterns across cell models, including antagonistic effects of AFB1 + OTA in most cell lines, dose-dependent interactions of DON + OTA, and low-dose synergistic effects in specific combinations. Overall, the results demonstrate that mycotoxin interactions are highly dependent on dose and target cell type, and that low-dose co-contamination may enhance toxicological risks, underscoring the importance of considering combined mycotoxin exposure in health risk assessment.

In the past few years, several mushroom poisoning incidents caused by Omphalotus species have occurred in China. In addition to O. guepiniformis and O. olearius, a new white Omphalotus species, O. yunnanensis, was discovered in Southwestern and Southern China based on morphological, molecular and toxin-detection evidence. Omphalotus yunnanensis is characterized by its small, cream to white basidiomata with a hygrophanous pileal surface, non-bioluminescent lamellae, broadly ellipsoid to subglobose basidiospores (8-12.5 × 7-10 μm), fusoid to ventricose cheilocystidia with occasional apical outgrowths, cream to white pileipellis composed of thick-walled, subsoil to solid hyphae, clavate, and fusoid to ventricose caulocystidia with occasional apical outgrowths. The species has been discovered in tropical to subtropical areas in Southwestern and Southern China. Phylogenetic analyses based on ITS and nrLSU showed that the new species clustered with the Australasian species O. nidiformis, but can be easily distinguished by its smaller, white to cream pileus, non-bioluminescent lamellae, larger basidiospores and growing on Fagaceae species. Illudin S was detected in this new species using UPLC-MS/MS, at 6.98 to 86.1 mg/kg of the content (dry weight), while no illudin M was detected.

This study investigated the effects of chronic MC-LR exposure (0 μg/L [Control], 1 μg/L [M1], 3 μg/L [M3], 10 μg/L [M10], and 30 μg/L [M30]) on the muscle nutrient composition, meat quality, and muscle proteomic profile of Nile tilapia (Oreochromis niloticus). In the high-dose group (M30), MC-LR exposure compromised the muscle antioxidant status of Nile tilapia, resulting in reduced meat quality, as evidenced by decreased pH value and water-holding capacity, elevated lipid/protein oxidation, and altered texture parameters (shear force and fragmentation index). Proteomic analysis further revealed a downregulation of proteins associated with ribosomes, suggesting an impairment of muscle protein synthesis in the M30 group. Moreover, despite chronic exposure, only low levels of MC-LR accumulated in the muscle tissue, indicating a negligible health risk to consumers. Collectively, these findings offered valuable insights into the impact of environmental MC-LR contamination on fish muscle quality and nutritional value.

Hazelnut (Corylus avellana L.) is a major crop in the Caucasus region, but its safety is often threatened by Aspergillus flavus colonization and aflatoxin contamination. Although aflatoxins (AFs) are strictly regulated in the EU, the influence of post-harvest practices on fungal persistence and AF accumulation remains poorly defined. A three-year study was conducted to evaluate the effects of drying protocols, storage temperature, and conservation practices on fungal growth and AF occurrence in hazelnuts from three producing regions of Azerbaijan. Freshly harvested nuts were subjected to two drying regimes: good drying (sun-exposed, mixed, protected from rewetting) and bad drying (shaded, piled, rewetted). After drying, samples were stored at cold (8-10 °C) or room temperature (18-22 °C). Fungal prevalence was determined by CFU counts with morphological and qPCR identification of Aspergillus section Flavi. AFs were quantified by HPLC, and water activity (a_w) was monitored during storage. Drying emerged as the decisive factor: bad drying consistently resulted in markedly higher fungal loads for A. section Flavi, with mean counts up to 1.3 log10 (CFU/g), compared with 0.8 log10 (CFU/g) under good drying, representing a 7-fold increase. In contrast, storage temperature and shell condition had negligible effects when nuts were properly dried. Aflatoxins were consistently below the 5 µg/kg EU limit for AFB₁ in traced and well-dried samples, whereas market samples occasionally exhibited AFB₁ concentrations >450 µg/kg. These findings highlight drying efficiency as the key determinant of fungal persistence and AF risk in hazelnut post-harvest management.

Protein-bound uremic toxins (PBUT), particularly indoxyl sulphate (IS) and p-cresyl sulphate (pCS), are poorly removed by conventional haemodialysis because of their strong albumin binding. These toxins are associated with cardiovascular morbidity and mortality in haemodialysis patients. Displacer molecules such as ibuprofen enhance PBUT clearance by competing for albumin-binding sites, but the optimal dose and route of administration remain unclear. The aim of this study was to evaluate the effect of different ibuprofen doses, infusion durations, and routes of administration on the removal of IS and pCS during on-line hemodiafiltration (OL-HDF). In this prospective, single-centre, crossover study, 21 chronic haemodialysis patients receiving intradialytic analgesia underwent nine OL-HDF sessions. Ibuprofen was administered at two doses (400 or 800 mg) either in the arterial pre-filter line (infusion over 1 h, 2 h, or 3 h) or in the venous post-filter line (30 min). Reduction ratios (RR) of total IS and pCS were determined by LC-MS and corrected for haemoconcentration. Statistical analysis included repeated-measures ANOVA with post-hoc testing. Baseline RR for IS and pCS were 53.7 ± 9.9% and 47.1 ± 10.9%, respectively. The highest RR was achieved with 800 mg ibuprofen infused via the arterial line over 2 h (IS: 60.8 ± 8.6%; pCS: 57.8 ± 9.7%). All arterial-line 800 mg regimens and the 3-h 400 mg infusion significantly improved pCS clearance versus baseline; IS clearance improved significantly only with arterial-line 800 mg regimens and with the 400 mg 3-h infusion. Infusion rate (1-3 h) had no significant effect on RR within the same dose group. Pain scores decreased significantly after dialysis regardless of ibuprofen regimen. Arterial-line administration of ibuprofen enhances total IS and pCS removal during OL-HDF, with higher doses yielding greater clearance. Prolonged low-dose infusion appears similarly effective for pCS and may reduce systemic exposure, potentially lowering toxicity risk. These findings support the arterial line as the preferred route for displacer administration in clinical practice.

Clostridial neurotoxins, botulinum neurotoxins (BoNTs), and tetanus neurotoxin (TeNT) are potent toxins responsible for severe diseases, botulism and tetanus, respectively. BoNTs associate with non-toxic proteins (non-toxic non-hemagglutinin, hemagglutinins, and OrfXs), which protect BoNTs against acidic pH and protease degradation and facilitate BoNT passage through the intestinal barrier. TeNT enters motor neurons and undergoes a retrograde axonal transport until the target inhibitory interneurons in the central nervous system. BoNTs and TeNT recognize specific cell surface receptors which consist of complex sets of protein(s)-glycan-gangliosides and determine specific cell entry pathways. Recent data on structural and functional investigations of BoNT and TeNT receptors bring a better understanding of toxin trafficking in the host and entry into target neuronal cells, which is useful for the development of updated strategies of prevention and treatment of the corresponding diseases. Since clostridial neurotoxins, notably BoNTs, are important therapeutic tools, detailed knowledge of their activity opens the way of the development of engineered molecules for specific clinical applications.