RESUMEN
210Po has been identified as one of the main contributors to ingestion doses to humans, particularly from the consumption of seafood. The amount of 210Po activity concentration data for various types of seafood has increased greatly in recent times. However, to provide realistic seafood dose assessments, most 210Po data requires correction to account for losses that can occur before the seafood is actually consumed. Here we develop generic correction factors for the main processes associated with reduction of 210Po in seafood - leaching during cooking, radioactive decay between harvest and consumption, and sourcing from mariculture versus wild-caught. When seafood is cooked, the overall mean fraction of 210Po retained is 0.74 for all cooking and seafood types, with the means for various seafood types and cooking categories ranging from 0.56 to 1.03. When considering radioactive decay during the period between harvest and consumption, the overall mean fraction remaining is 0.81 across all seafood preservation/packaging types, with estimates ranging from 0.50 (canned seafood) to 0.98 (fresh seafood). Regarding mariculture influence, the available limited data suggest marine fish and crustaceans raised with processed feed have about one order of magnitude lower (×0.10) 210Po muscle content than wild-caught seafood of the same or similar species, although this ratio varies. Overall, this study concludes that 210Po activity concentrations in seafood at the time of ingestion may be reduced to only about 55% compared to when it was harvested. Therefore, correction factors must be applied to any data derived from environmental monitoring in order to achieve realistic dose estimates. The data also suggest lower 210Po ingestion doses for consumers who routinely favour cooked, long shelf-life and farmed fish/crustaceans. However, more data is needed in some categories, especially for cooking of molluscs and seaweed, and for the 210Po content in all farmed seafood.
Asunto(s)
Polonio , Monitoreo de Radiación , Animales , Humanos , Alimentos Marinos/análisis , Polonio/análisis , Culinaria , Peces , CrustáceosRESUMEN
Polysialic acid (polySia/PSA) is a linear homopolymer of sialic acid (Sia) that primarily modifies the neural cell adhesion molecule (NCAM) in mammalian brains. PolySia-NCAM not only displays an anti-adhesive function due to the hydration effect, but also possesses a molecule-retaining function via a direct binding to neurologically active molecules. The quality and quantity of polySia determine the function of polySia-NCAM and are considered to be profoundly related to the maintenance of normal brain functions. In this study, to compare the structures of polySia-NCAM in brains of five different vertebrates (mammals, birds, reptiles, amphibians, and fish), we adopted newly developed combinational methods for the analyses. The results revealed that the structural features of polySia considerably varied among different species. Interestingly, mice, as a mammal, possess eminently distinct types of polySia, in both quality and quantity, compared with those possessed by other animals. Thus, the mouse polySia is of larger quantities, of longer and more diverse chain lengths, and of a larger molecular size with higher negative charge, compared with polySia of other species. These properties might enable more advanced brain function. Additionally, it is suggested that the polySia/Sia ratio, which likely reflects the complexity of brain function, can be used as a new promising index to evaluate the intelligence of different vertebrate brains.
Asunto(s)
Encéfalo/metabolismo , Ácidos Siálicos/metabolismo , Animales , Pollos , Carpa Dorada , Ratones , Reptiles , Especificidad de la Especie , Xenopus laevisRESUMEN
Polysialic acid (polySia/PSA) is an anionic glycan polymer of sialic acid, and it mostly modifies the neural cell adhesion molecule (NCAM) in mammalian brains. Quality and quantity of the polySia of the polySia-NCAM is spatio-temporally regulated in normal brain development and functions, and their impairments are reported to be related to diseases, such as psychiatric disorders and cancers. Therefore, precise understanding of the state of polySia-NCAM structure would lead to the diagnosis of diseases for which their suitable evaluation methods are necessary. In this study, to develop these evaluation methods, structures of polySia-NCAM from mouse brains at six different developmental stages were analyzed by several conventional and newly developed methods. Integrated results of these experiments clearly demonstrated the existence of different types of polySia-NCAMs in developing brains. In addition, combinational analyses were shown to be useful for precise understanding of the quantity and quality of polySia, which can provide criteria for the diagnosis of diseases.
Asunto(s)
Encéfalo/metabolismo , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Procesamiento Proteico-Postraduccional , Ácidos Siálicos/metabolismo , Animales , Encéfalo/crecimiento & desarrollo , Ratones , Ratones Endogámicos C57BLRESUMEN
On 1 April 2017, around 6 y after the Fukushima Daiichi nuclear power station accident, evacuation orders for large affected areas were lifted, and areas to which people could return were expanded. In the current study, a dose estimation model based on a probabilistic approach has been developed to estimate the external radiation doses children would receive after returning to these areas. The target groups are children from infants to high school students, and the target areas are nine municipalities including evacuation areas as of 5 September 2015. The estimation period is for 4 y starting 1 April 2017. Validation of the model in an area for which individual personal dosimetry measurements were available showed that it is valid for infants, kindergarteners, 3rd and 4th grade elementary school students, 5th and 6th grade elementary school students, and junior high school students. Considering the statement of the International Commission on Radiological Protection, the estimated radiation doses for these five age groups were taken to be the 95th percentiles of the predicted distributions as an index of conservative judgement. As a result of our estimations, the 95th percentile doses to all age groups were less than 20 mSv y in all periods and in all areas. The 95th percentile doses in some areas were less than 1 mSv y, which is the long-term dosimetric target set by the Japanese government. It should be noted that our results are preliminary, being based on several assumptions and limitations regarding environmental contamination conditions and the behavioral patterns of children. To estimate the children's doses precisely, further considerations for these assumptions and limitations will be needed.
Asunto(s)
Accidente Nuclear de Fukushima , Modelos Estadísticos , Exposición a la Radiación/análisis , Monitoreo de Radiación/métodos , Protección Radiológica/normas , Medición de Riesgo/métodos , Adolescente , Niño , Preescolar , Toma de Decisiones , Femenino , Humanos , Lactante , Recién Nacido , Japón , Masculino , Estudios Prospectivos , Dosis de RadiaciónRESUMEN
A 53-year-old immunocompetent male visited our hospital complaining of chest pain which persisted for 6 h. After detailed examination, the patient was diagnosed with viral pericarditis and treated with aspirin. On day 3 after admission, rash with blisters appeared on the right side of chest. Paired serum evaluation on the day of admission and 3 weeks later revealed that varicella zoster virus(VZV)titer had significantly increased, and the patient was diagnosed with pericarditis caused by herpes zoster. Although VZV is known to cause various complications, there are few reports of pericarditis associated with VZV. We should consider the possibility of concomitant pericarditis with herpes zoster.
RESUMEN
Polysialic acid (polySia) is mainly found as a modification of neural cell adhesion molecule (NCAM) in whole embryonic brains, as well as restricted areas of adult vertebrate brains, including the hippocampus. PolySia shows not only repulsive effects on NCAM-involved cell-cell interactions due to its bulky and hydrated properties, but also attractive effects on the interaction with neurologically active molecules, which exerts a reservoir function. Two different polysialyltransferases, ST8SIA2 and ST8SIA4, are involved in the synthesis of polySia chains; however, to date, the differences of the properties between polySia chains synthesized by these two enzymes remain unknown. In this study, to clarify this point, we first prepared polySia-NCAMs from HEK293 cells stably expressing ST8SIA4 and ST8SIA2, or ST8SIA2 (SNP-7), a mutant ST8SIA2 derived from a schizophrenia patient. The conventional sensitive chemical and immunological characterizations showed that the quantity and quality (structural features) of polySia are not so much different between ST8SIA4- and ST8SIA2-synthesized ones, apart from those of ST8SIA2 (SNP-7). Then, we assessed the homophilic and heterophilic interactions mediated by polySia-NCAM by adopting a surface plasmon resonance measurement as an in vitro analytical method. Our novel findings are as follows: (i) the ST8SIA2- and ST8SIA4-synthesized polySia-NCAMs exhibited different attractive and repulsive effects than each other; (ii) both polySia- and oligoSia-NCAMs synthesized by ST8SIA2 were able to bind polySia-NCAMs; (iii) the polySia-NCAM synthesized by a ST8SIA2 (SNP-7) showed markedly altered attractive and repulsive properties. Collectively, polySia-NCAM is suggested to simultaneously possess both attractive and repulsive properties that are highly regulated by the two polysialyltransferases.
Asunto(s)
Moléculas de Adhesión de Célula Nerviosa/metabolismo , Esquizofrenia/metabolismo , Ácidos Siálicos/química , Sialiltransferasas/metabolismo , Química Encefálica , Expresión Génica , Células HEK293 , Humanos , Mutación , Moléculas de Adhesión de Célula Nerviosa/genética , Moléculas de Adhesión de Célula Nerviosa/aislamiento & purificación , Plásmidos/química , Plásmidos/metabolismo , Unión Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Esquizofrenia/genética , Esquizofrenia/fisiopatología , Ácidos Siálicos/biosíntesis , Ácidos Siálicos/aislamiento & purificación , Sialiltransferasas/genética , Sialiltransferasas/aislamiento & purificación , Electricidad Estática , Resonancia por Plasmón de SuperficieRESUMEN
The neural cell adhesion molecule (NCAM) is modified by polysialic acid (polySia or PSA) in embryonic brains. In adult brains, polySia modification of NCAM is only observed in restricted areas where neural plasticity, remodeling of neural connections, or neural generation is ongoing although the amount of NCAM remains unchanged. Impairments of the polySia-expression and several single nucleotide polymorphisms (SNPs) of the polysialyltransferase (polyST) ST8SIA2 gene are reported to be associated with schizophrenia and bipolar disorder. Chlorpromazine (CPZ) is well-known as an agent for treating schizophrenia, and our hypothesis is that CPZ may affect the polySia expression or the gene expression of polySTs or NCAM. To test this hypothesis, we analyzed the effects of CPZ on the expression of polySia-NCAM on human neuroblastoma cell line, IMR-32 cells, by immunochemical and chemical methods. Interestingly, the cell surface expression of polySia, especially those with lower chain lengths, was significantly increased on the CPZ-treated cells, while mRNAs for polySTs and NCAM, and the amounts of total polySia-NCAM remained unchanged. The addition of brefeldin A, an inhibitor of endocytosis, suppressed the CPZ-induced cell surface polySia expression. In addition, polySia-NCAM was also observed in the vesicle compartment inside the cell. All these data suggest that the level of cell surface expression of polySia in IMR-32 is highly regulated and that CPZ changes the rate of the recycling of polySia-NCAM, leading to the up-regulation of polySia-NCAM on the cell surface. We also analyzed the effect of CPZ on polySia-expression in various brain regions in adult mice and found that CPZ only influenced the total amounts of polySia-NCAM in prefrontal cortex. These results suggest a brain-region-specific effect of CPZ on the expression of total polySia in mouse brain. Collectively, anti-schizophrenia agent CPZ consistently up-regulates the expression polySia at both cellular and animal levels.
Asunto(s)
Antipsicóticos/farmacología , Clorpromazina/farmacología , Corteza Prefrontal/efectos de los fármacos , Esquizofrenia/genética , Ácidos Siálicos/genética , Regulación hacia Arriba/efectos de los fármacos , Animales , Línea Celular Tumoral , Humanos , Ratones , Moléculas de Adhesión de Célula Nerviosa/genética , Plasticidad Neuronal/efectos de los fármacos , Polimorfismo de Nucleótido Simple , Corteza Prefrontal/metabolismo , Esquizofrenia/tratamiento farmacológico , Sialiltransferasas/genéticaRESUMEN
A new sialic acid (Sia)-containing glycopolymer-a fluorescent probe with high-density disialic acid (diSia) on the surface of polysaccharide dextran (diSia-Dex)-was synthesized as a key molecule to regulate the Sia recognition lectins, Siglecs, that are involved in the immune system. According to our original methods, diSia was synthesized by α-selective sialylation, and a dextran template possessing terminal acetylenes and amino groups was prepared. A diSia and a fluorescent molecule were subsequently introduced to surface-modified dextran by Hüisgen reaction and amidation, respectively. The modulatory activity of Siglec7 was evaluated by using synthetic probes. DiSia-Dex showed high binding avidity toward Siglec7, with a KD value of 5.87×10-10 m, and a high inhibitory activity for the interaction between Siglec7 and a ligand (GD3), with a IC50 value of 1.0â nm. Notably, diSia-Dex was able to release Siglec7 from the pre-existing Siglec7-GD3 complex, possibly due to its unique properties of a slow dissociation rate and a high association rate. Together, these data show that diSia-Dex can be widely applicable as a modulator of Siglec7 functions.
Asunto(s)
Antígenos de Diferenciación Mielomonocítica/química , Dextranos/química , Gangliósidos/química , Lectinas/química , Proteínas Recombinantes de Fusión/química , Ácidos Siálicos/química , Animales , Antígenos de Diferenciación Mielomonocítica/genética , Antígenos de Diferenciación Mielomonocítica/metabolismo , Sitios de Unión , Células CHO , Conformación de Carbohidratos , Secuencia de Carbohidratos , Técnicas de Química Sintética , Cricetulus , Dextranos/síntesis química , Dextranos/metabolismo , Dextranos/farmacología , Colorantes Fluorescentes/química , Gangliósidos/antagonistas & inhibidores , Gangliósidos/metabolismo , Expresión Génica , Humanos , Fragmentos Fc de Inmunoglobulinas/química , Fragmentos Fc de Inmunoglobulinas/genética , Fragmentos Fc de Inmunoglobulinas/metabolismo , Inmunoglobulina G/química , Inmunoglobulina G/genética , Inmunoglobulina G/metabolismo , Cinética , Lectinas/antagonistas & inhibidores , Lectinas/genética , Lectinas/metabolismo , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica/efectos de los fármacos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Ácidos Siálicos/metabolismoRESUMEN
Large quantities of radioactive materials were released into the environment as a result of the Fukushima Daiichi Nuclear Power Station accident. Many inhabitants residing in the affected areas are now exposed to radiation in their daily lives. In an attempt to manage this radiation dose, an additional radiation dose of 1 mSv/y was adopted as a long-term dosimetric target. An activity level reading of 0.23 µSv/h was then determined as a guidance value to achieve the target by implementing decontamination measures. The objectives of this study are to assess the effects of decontamination based on this guidance value and to predict any possible future problems with the decontamination strategy. Using a probabilistic approach, we assessed the annual effective dose of indoor workers, outdoor workers, and pensioners in the Fukushima Prefecture. Our probabilistic model considers the variabilities in behavioral patterns and Cs-137 surface-activity levels. Five years after the initial contamination, the 95th percentiles of indoor workers and pensioners in 53 of the 59 municipalities were found to receive annual effective doses of below 1 mSv/y (0.026-0.73 mSv/y). However, for outdoor workers in 25 municipalities, the annual doses were over 1 mSv/y (1.0-35 mSv/y). Therefore, the guidance value is effective for indoor workers and pensioners; to determine whether additional countermeasures for outdoor workers should be implemented, a detailed assessment that uses more realistic assumptions is required.