RESUMEN
Antarctica stands as one of the most isolated and pristine regions on our planet. Regardless, recent studies have evidenced the presence of plastic pollution in Antarctic environments and biota. While these findings are alarming and put into perspective the reach of plastic pollution, it is necessary to assess the current knowledge of plastic pollution in Antarctica. In the present review, an updated literature review of plastic pollution in multiple Antarctic environmental compartments and biota was conducted. Studies were cataloged based on environmental compartments (e.g., sediments, seawater, soil, atmosphere) and biota from different ecological niches. A detailed analysis of the main findings, as well as the flaws and shortcomings across studies, was conducted. In general terms, several studies have shown a lack of adequate sampling and analytical procedures for plastic research (particularly in the case of microplastics) and standard procedures; thus, compromising the reliability of the data reported and comparability across studies. Aiming to guide future studies and highlight research needs, a list of knowledge gaps and recommendations were provided based on the analysis and discussion of the literature and following standardized procedures.
Asunto(s)
Plásticos , Contaminantes Químicos del Agua , Regiones Antárticas , Reproducibilidad de los Resultados , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , EcosistemaRESUMEN
Increasing amount of anthropogenic litter in the marine environment has provided an enormous number of substrates for a wide range of marine organisms, thus serving as a potential vector for the transport of fouling organisms. Here, we examined the fouling organisms on different types of stranded litter (plastic, glass, rubber, foam sponge, cloth, metal and wood) on eight beaches along the southeast coast of India. In total, 17 encrusting species belonging to seven phyla (Arthropoda, Bryozoa, Mollusca, Annelida, Cnidaria, Chlorophyta and Foraminifera) were identified on 367 items, with one invasive species, the mussel Mytella strigata, detected. The most common species associated with marine litter were the cosmopolitan bryozoans Jellyella tuberculata (%O = 31.64 %) and J. eburnea (28.61 %), the barnacle species Lepas anserifera (29.97 %), Amphibalanus amphitrite (22.34 %) and Amphibalanus sp. (14.16 %), and the oyster species Saccostrea cucullata (13.62 %) and Magallana bilineata (5.44 %). We also reported the first records on stranded litter of four species: the gastropod species Pirenella cingulata and Umbonium vestiarium, the foraminiferan Ammonia beccarii, and the oyster M. bilineata. This study is thus the first documentation of marine litter as a vector for species dispersal in India, where the production and consumption of plastic rank among the highest in the world. We also highlight the increasing risk of invasions by non-indigenous organisms attached to debris along the southeast coast of India. Comprehensive monitoring efforts are thus needed to elucidate the type of vectors responsible for the arrival of invasive species in this region. Raising awareness and promoting education are vital components in fostering sustainable solutions to combat plastic pollution in the country and globally.
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Briozoos , Ostreidae , Animales , Monitoreo del Ambiente , Plásticos/química , Madera/química , Textiles , Especies Introducidas , Residuos/análisis , PlayasRESUMEN
COVID-19 pandemic has enforced the use of personal protective equipment (PPE, masks and gloves). However, the mismanagement of litter are exacerbating the increasing plastic issue worldwide. In the present study, we sampled discarded PPE in 10 sites along Marina Beach, India. We characterized the litter types by chemical analysis techniques. A total of 1154 COVID-19-associated PPE items were found on Marina beach. The highest number of items were face masks (97.9 %) and the mean PPE density in the sites studied was 4 × 10-3 PPE m-2. The results demonstrate that poor solid waste management and lack of awareness are the main causes of pollution at Marina beach. FTIR spectroscopy revealed that face masks and gloves were principally made of polypropylene and latex, respectively. The FTIR spectra also showed signs of chemical degradation. Our results suggest that plastic pollution is increasing, possibly becoming more impactful to marine biota. Beach management measures were discussed.
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COVID-19 , Humanos , Pandemias , Equipo de Protección Personal , Asia , PlásticosRESUMEN
Human IgG2 antibodies contain three types of disulfide isoforms, classified by the number of Fab arms having disulfide links to the heavy chain hinge region. In the IgG2-B form, both Fab arms have interchain disulfide bonds to the hinge region, and in IgG2-A, neither Fab arm are disulfide linked to the hinge. The IgG2-A/B is a hybrid between these two forms, with only one Fab arm disulfide linked to the hinge. Changes in the relative levels of these forms over time are observed while IgG2 circulates in humans, suggesting IgG2-AâIgG2-A/BâIgG2-B conversion. Using a flow-through dialysis system, we studied the conversion kinetics of these forms in vitro under physiological conditions. For two IgG2κ antibodies, in vivo results closely matched the kinetics observed in vitro, indicating that the changes observed in vivo were solely conversions between isoforms, not differential clearance of specific forms. Moreover, the combined results validate the accuracy of the physiological model for the study of blood redox reactions. Further exploration of the conversion kinetics using material enriched in the IgG2-A forms revealed that the IgG2-AâIgG2-A/B rate was similar between IgG2κ and IgG2λ antibodies. In IgG2κ antibodies, conversion of IgG2-A/BâIgG2-B was slower than the IgG2-AâIgG2-A/B reaction. However, in IgG2λ antibodies, little IgG2-A/BâIgG2-B conversion was detected under physiological conditions. Thus, small differences in the C-terminus of the light chain sequences affect the disulfide conversion kinetics and impact the IgG2 disulfide isoforms produced in vivo.
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Disulfuros/química , Inmunoglobulina G/química , Inmunoglobulina G/metabolismo , Animales , Humanos , Inmunoglobulina G/administración & dosificación , Cinética , Ratones , Oxidación-Reducción , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismoRESUMEN
The unique cation exchange chromatography (CEX) charge variant profile of mAb1 is characterized by a combination of mass spectrometry, limited Lys-C digestion followed by CEX separation and structural analysis. During CEX method development, mAb1 showed several unexpected phenomena, including a unique profile containing two main species (acidic 2 and main) and significant instability during stability studies of the main species. Reduced Lys-C peptide mapping identified a small difference in one of the heavy chain peptides (H4) in acidic 2 and further mass analysis identified this difference as Asn55 deamidation. However, the amount of Asn55 deamidation in acidic 2 could account for only half of the species present in this peak. Lys-C limited digest followed by CEX separated several unique peaks in the acidic peak 2 including two pre Fab peaks (LCC1 and LCC2). Whole protein mass analysis suggested that both LCC1 and LCC2 were potentially deamidated species. Subsequent peptide mapping with MS/MS determined that LCC1 contained isoAsp55 and LCC2 contained Asp55. Combining LCC1 and LCC2 CEX peak areas could account for nearly all of the species present in acidic peak 2. Subsequent detailed sequence analysis combined with molecular modeling identified Asn55 and its surrounding residues are responsible for the different CEX behavior and instability of mAb1 following forced degradation at high pH. Overall, the combinatorial approach used in this study proved to be a powerful tool to understand the unique charge variant and stability profile of a monoclonal antibody.