Using flow cytometry to detect haemic neoplasia in mussels (Mytilus trossulus) from the Pacific Coast of Southern British Columbia, Canada.

Flow cytometry was investigated as an alternative to visual haemocytology for potentially higher-throughput and less subjective detection of neoplasia in Mytilus trossulus. In contrast to previous studies of ploidy in the Mytilus spp. complex, distinct tetra- and pentaploidal neoplastic cells were rare and a wide range of aneuploidy peaks from 1.4n to 5.5n were detected for late-stage leukemic animals. There was no correlation between aneuploidy and the number of diseased cells for early and intermediate disease stages. Formation of aneuploidy and neoplasia progression might not be simultaneous, and DNA content analysis using flow cytometry was only useful for detecting late stages of the disease.

Domestic laundry and microfiber pollution: Exploring fiber shedding from consumer apparel textiles.

Synthetic fibers are increasingly seen to dominate microplastic pollution profiles in aquatic environments, with evidence pointing to textiles as a potentially important source. However, the loss of microfibers from textiles during laundry is poorly understood. We evaluated microfiber release from a variety of synthetic and natural consumer apparel textile samples (n = 37), with different material types, constructions, and treatments during five consecutive domestic laundry cycles. Microfiber loss ranged from 9.6 mg to 1,240 mg kg-1 of textile per wash, or an estimated 8,809 to > 6,877,000 microfibers. Mechanically-treated polyester samples, dominated by fleeces and jerseys, released six times more microfibers (161 ± 173 mg kg-1 per wash) than did nylon samples with woven construction and filamentous yarns (27 ± 14 mg kg-1 per wash). Fiber shedding was positively correlated with fabric thickness for nylon and polyester. Interestingly, cotton and wool textiles also shed large amounts of microfibers (165 ± 44 mg kg-1 per wash). The similarity between the average width of textile fibers here (12.4 ± 4.5 µm) and those found in ocean samples provides support for the notion that home laundry is an important source of microfiber pollution. Evaluation of two marketed laundry lint traps provided insight into intervention options for the home, with retention of up to 90% for polyester fibers and 46% for nylon fibers. Our observation of a > 850-fold difference in the number of microfibers lost between low and high shedding textiles illustrates the strong potential for intervention, including more sustainable clothing design.

Pervasive distribution of polyester fibres in the Arctic Ocean is driven by Atlantic inputs.

Microplastics are increasingly recognized as ubiquitous global contaminants, but questions linger regarding their source, transport and fate. We document the widespread distribution of microplastics in near-surface seawater from 71 stations across the European and North American Arctic - including the North Pole. We also characterize samples to a depth of 1,015 m in the Beaufort Sea. Particle abundance correlated with longitude, with almost three times more particles in the eastern Arctic compared to the west. Polyester comprised 73% of total synthetic fibres, with an east-to-west shift in infra-red signatures pointing to a potential weathering of fibres away from source. Here we suggest that relatively fresh polyester fibres are delivered to the eastern Arctic Ocean, via Atlantic Ocean inputs and/or atmospheric transport from the South. This raises further questions about the global reach of textile fibres in domestic wastewater, with our findings pointing to their widespread distribution in this remote region of the world.

Variations in p53-like cDNA sequence are correlated with mussel haemic neoplasia: A potential molecular-level tool for biomonitoring.

Several bivalve species, including mussels (Mytilus spp.) and clams (Mya spp.), are susceptible to a leukemia-like disease called haemic neoplasia that has been known to decimate whole populations. Previous studies of molecular processes associated with late stages of this disease have implicated analogs of the p53 tumour suppressor protein family in disease etiology. We detected synonymous single nucleotide polymorphisms (SNPs) in the coding region sequence of p53-like cDNA from Mytilus trossulus (bay mussel) that differ between normal and neoplastic haemolymph. SNPs were located at positions 182, 392 and 821 bp. Most (94%) of the late leukemic animals sampled from cages in Burrard Inlet (British Columbia, Canada) had the same p53-like genotype, C182T G392G C821T, whereas 75% of the healthy animals were homozygous at positions C182C and T821T, independent of the genotype at the 392 bp position. As well, we detected an increased number of allelic variants in the leukemic animals that may arise from separate somatic mutation events in haemocyte precursors or from additional p53-like gene copies in polyploidy. Therefore, detection of these SNPs may provide a useful genetic biomarker for efficient monitoring of mussel population health.

Paradoxical impact of antioxidants on post-Amadori glycoxidation: Counterintuitive increase in the yields of pentosidine and Nepsilon-carboxymethyllysine using a novel multifunctional pyridoxamine derivative.

The inhibition of post-Amadori advanced glycation end product (AGE) formation by three different classes of AGE inhibitors, carbonyl group traps, chelators, and radical-trapping antioxidants, challenge the current paradigms that: 1) AGE inhibitors will not increase the formation of any AGE product, 2) transition metal ions are required for oxidative formation of AGE, and 3) screening AGE inhibitors only in systems containing transition metal ions represents a valid estimate of potential in vivo mechanisms. This work also introduces a novel multifunctional AGE inhibitor, 6-dimethylaminopyridoxamine (dmaPM), designed to function as a combined carbonyl trap, metal ion chelator, and radical-trapping antioxidant. Other AGE inhibitors including pyridoxamine, aminoguanidine, o-phenylenediamine, dipyridoxylamine, and diethylenetriaminepentaacetic acid were also examined. The results during uninterrupted and interrupted ribose glycations show: 1) an unexpected increase in the yield of pentosidine in the presence of radical-trapping phenolic antioxidants such as Trolox and dmaPM, 2) significant formation of Nepsilon-carboxymethyllysine (CML) in the presence of strong chelators and phenolic antioxidants, which implies that there must be nonradical routes to CML, 3) prevention of intermolecular cross-links with radical-trapping inhibitors, and 4) that dmaPM shows excellent inhibition of AGE. Glucose glycations reveal the expected inhibition of pentosidine and CML with all compounds tested, but in a buffer free of trace metal ions the yield of CML in the presence of radical-trapping antioxidants was between the metal ion-free and metal ion-containing controls. Protein molecular weight analyses support the conclusion that Amadori decomposition pathways are constrained in the presence of metal ion chelators and radical traps.