RESUMEN
This study focuses on gender-specific accumulation features of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in common (great) cormorants (Phalacrocorax carbo) collected from Lake Biwa, Japan. Male cormorants showed a tendency to have higher levels of PCDD/DFs and DL-PCBs than did females. For PCDDs, the male-to-female concentration ratio (M/F ratio) for each congener significantly decreased with the liver-to-muscle concentration ratio (Li/Mu ratio). For PCDFs, there also was a weak negative relationship between Li/Mu ratio and M/F ratio. In contrast, for DL-PCBs, M/F ratios showed no correlation with Li/Mu ratios, but increased with an increase in lipophilicity. These results, together with observations from prior studies, suggest that congener-specific hepatic sequestration may be a factor limiting the maternal transfer of PCDDs and, to a lesser extent, PCDFs. Maternal transfer of DL-PCBs seems to favor more lipophilic congeners in the cormorants.
Asunto(s)
Dioxinas/metabolismo , Monitoreo del Ambiente , Hígado/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Femenino , Japón , Masculino , Exposición Materna/estadística & datos numéricos , Factores SexualesRESUMEN
Widespread outbreaks of highly pathogenic avian influenza (HPAI) caused by H5N1 viruses occurred in wild birds in Japan from 2010-2011. Forty out of 63 deceased wild birds belonged to the order Anseriformes, and mandarin duck was one of the dominant species. To estimate the risk of mandarin ducks as a source of virus infection in the environment, we examined the pathogenicity of a causal H5N1 HPAI virus to mandarin ducks. About half of the mandarin ducks died by inoculation with 10(7.0)TCID50 of A/mandarin duck/Miyazaki/22M807-1/2011 (H5N1). Viruses were mainly recovered from the trachea of the ducks sacrificed at three days post inoculation (d.p.i.). Viruses were recovered from the laryngopharyngeal swabs of the observation group until 5 d.p.i. In ducks that died at the late phase of infection, viruses were detected in the systemic organs, such as lung, kidney and colon. Together, these results showed that the H5N1 HPAI viruses, which belonged to clade 2.3.2.1 and are mainly circulating in East Asia, were lethal to mandarin ducks, indicating that mandarin ducks have the potential to disseminate the virus to other bird species. Therefore, wild birds should be kept out of poultry farms to prevent HPAI outbreaks in the future.
Asunto(s)
Brotes de Enfermedades/veterinaria , Patos , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Gripe Aviar/epidemiología , Animales , Anticuerpos Antivirales/inmunología , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/virología , Japón/epidemiología , Especificidad de la Especie , Tráquea/virología , Replicación Viral/fisiología , Esparcimiento de Virus/fisiologíaRESUMEN
To validate the outcome of the national regulation on dioxins emission implemented in 1999, this study investigated temporal trends of chlorinated dioxins and related compounds (DRCs) in liver of common cormorants (Phalacrocorax carbo) collected from Lake Biwa, Japan between 2001 and 2008, as a part of the "Survey on the State of Dioxins Accumulation in Wildlife" conducted by the Ministry of the Environment, Japan. We also measured a biomarker of DRCs exposure, the cytochrome P450 1A (CYP1A)-dependent O-dealkylation activity of alkoxyresorufins (AROD), including methoxy-, ethoxy-, pentoxy- and benzyloxy-resorufins in the samples over 2001-2007. Neither TEQ nor AROD activity showed any clear declining trend over the time period, although the emission of DRCs during the corresponding period was estimated to be apparently decreasing. Our data indicate that the concentration of recalcitrant DRCs in the cormorant during 2001-2008 was scarcely affected by the national regulation on dioxins emission.
Asunto(s)
Hidrocarburo de Aril Hidroxilasas/metabolismo , Aves/metabolismo , Dioxinas/metabolismo , Contaminantes Ambientales/metabolismo , Animales , Benzofuranos/metabolismo , Benzofuranos/toxicidad , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP2B1/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Dibenzofuranos Policlorados , Dioxinas/toxicidad , Monitoreo del Ambiente , Política Ambiental , Contaminantes Ambientales/toxicidad , Contaminación Ambiental/prevención & control , Contaminación Ambiental/estadística & datos numéricos , Inducción Enzimática , Femenino , Japón , Lagos , Hígado/enzimología , Masculino , Bifenilos Policlorados/metabolismo , Bifenilos Policlorados/toxicidad , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/metabolismo , Dibenzodioxinas Policloradas/toxicidadRESUMEN
Two improved methods have been developed for preparation of fatty acid methyl esters (FAME) from major O-ester lipid classes in blood, i.e., cholesterol ester, triacylglycerol, and glycerophospholipids. The methods involve simple operations, and use neither harmful solvents such as chloroform or benzene nor highly reactive volatile reagents such as acetyl chloride. The FAME synthesis reaction proceeds under mild temperature conditions. The methods include (1) extraction of lipids from 0.2 ml of blood with 0.2 ml of tert-butyl methyl ether and 0.1 ml of methanol, (2) separation of the total lipids into lipid classes using a solid-phase extraction column or thin-layer chromatography, and (3) methanolysis of each lipid class at room temperature or at 45 °C. In all the operations, solvent concentration is performed only once prior to gas-liquid chromatography (GC). No noticeable differences in composition determined by GC have been found between FAME prepared by the present methods and those prepared by a conventional method involving lipid extraction with chloroform/methanol. The mild reaction and simplified procedures of the present methods enabled safe and reproducible analysis of the fatty acid compositions of the major ester-lipid classes in blood.
Asunto(s)
Análisis Químico de la Sangre/métodos , Ácidos Grasos/análisis , Lípidos/análisis , Lípidos/clasificación , Algoritmos , Análisis Químico de la Sangre/normas , Fraccionamiento Químico/métodos , Cromatografía de Gases , Cromatografía en Capa Delgada , Ácidos Grasos/sangre , Ácidos Grasos/química , Ácidos Grasos/clasificación , Humanos , Lípidos/sangre , Lípidos/química , Metanol/química , Metanol/farmacología , Éteres Metílicos/química , Éteres Metílicos/farmacología , Extracción en Fase Sólida/métodos , Solventes/química , Solventes/farmacologíaRESUMEN
KOH in aqueous methanol catalyzes selective methanolysis of polar glycerolipids with O-ester-linked acyl residues, while triacylglycerols and sterol esters are inert in the solution. Based on these findings, a convenient and reliable method was developed for the preparation of fatty acid methyl esters (FAMEs) from polar glycerolipids in lipid mixtures without prior isolation. Methanolysis of polar glycerolipids was completed within 2.5 min by vortexing or 20 min by shaking with 0.7 M KOH/70% (v/v) methanol in the presence of hexane at 30 degrees C. The yields of FAMEs obtained by the present method were greater than 95%. The method was applied successfully to gas chromatographic analysis of the fatty acid compositions of polar glycerolipids in seed oil and blood. No obvious differences were found between the fatty acid compositions determined by the present method and those determined by conventional methods, including lipid extraction with chloroform/methanol followed by isolation of polar lipids by chromatography. The fatty acid composition of polar glycerolipids, including phospholipids, can be determined readily in many crude samples.
Asunto(s)
Ácidos Grasos/síntesis química , Glicéridos/metabolismo , Metanol/metabolismo , Metanol/farmacología , Sangre/metabolismo , Análisis Químico de la Sangre/métodos , Catálisis , Cromatografía de Gases , Ésteres , Ácidos Grasos/química , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Metabolismo de los Lípidos/efectos de los fármacos , Lípidos/sangre , Lípidos/aislamiento & purificación , Metano/análogos & derivados , Metano/química , Aceites de Plantas/química , Especificidad por Sustrato , Agua/farmacologíaRESUMEN
On April 21, 2008, four whooper swans were found dead at Lake Towada, Akita prefecture, Japan. Highly pathogenic avian influenza virus of the H5N1 subtype was isolated from specimens of the affected birds. The hemagglutinin (HA) gene of the isolate belongs to clade 2.3.2 in the HA phylogenetic tree.
Asunto(s)
Anseriformes/virología , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Animales , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/virología , Japón/epidemiologíaRESUMEN
Concentrations of dioxins and related compounds (DRCs), such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs), were determined in black-eared kites (BEKs; Milvus migrans) collected from the Kanto district in Japan. Total 2,3,7,8-tetra-CDD toxic equivalents (TEQs) were in the range of 99 to 3,800 pg/g lipid weight in the liver and 42 to 760 pg/g lipid weight in the pectoral muscle. Three congeners, including PCB 126, 2,3,4,7,8-penta-CDF, and 1,2,3,7,8-penta-CDD, made a greater contribution to total TEQs in both tissues. Levels of ethoxyresorufin-O-deethylase activity and a cross-reactive protein with anti-rat cytochrome P4501A (CYP1A) polyclonal antibodies showed no significant correlation with hepatic TEQs. This may be attributed to low sensitivity and insufficient TEQ levels to cause CYP1A induction, high metabolic potential of a series of congeners, and influence of CYP1A inducers other than DRCs. Most of the PCDD/ Fs and non-ortho Co-PCBs exhibited a total TEQ- and CYP1A-dependent increase in the liver to muscle concentration ratios, implying their concentration-dependent hepatic sequestration in which CYP1A was involved. Comparison of the toxicokinetics in avian species revealed that BEKs possibly have higher potentials than common cormorants for metabolizing and sequestering certain congeners in the liver in terms of hepatic concentration profiles and liver:muscle concentration ratios, respectively. These results clearly indicate that the toxicokinetics of DRCs is congener-, tissue-, and species-specific as well as concentration-dependent. Therefore, CYP1A expression is one of the critical factors that determine the toxicokinetics in wild avian species.
Asunto(s)
Benzofuranos/toxicidad , Sistema Enzimático del Citocromo P-450/metabolismo , Falconiformes/metabolismo , Hígado/metabolismo , Bifenilos Policlorados/toxicidad , Dibenzodioxinas Policloradas/análogos & derivados , Animales , Benzofuranos/farmacocinética , Dibenzofuranos Policlorados , Regulación Enzimológica de la Expresión Génica , Cinética , Hígado/enzimología , Músculos/efectos de los fármacos , Músculos/enzimología , Bifenilos Policlorados/farmacocinética , Dibenzodioxinas Policloradas/metabolismo , Dibenzodioxinas Policloradas/farmacocinética , Dibenzodioxinas Policloradas/toxicidad , RatasRESUMEN
This study presents concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like coplanar PCBs (Co-PCBs) in the liver and breast muscle of jungle crows (JCs; Corvus macrorhynchos) collected from Tokyo, Japan. 2,3,7,8-Tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) derived by WHO bird-TEF were in the range of 23 to 280 pg/g (lipid) in the liver, which are lower or comparable to the lowest-observed-effect-level of CYP induction in chicken, and 5.6-78 pg/g (lipid) in the pectoral muscle. Cytochrome P450 (CYP) 1A-, 2B-, 2C-, and 3A-like proteins were detected using anti-rat CYP polyclonal antibodies in hepatic microsomal fractions. Significant (p < 0.05) positive correlations between hepatic TEQs and CYP1A or CYP3A-like protein expression levels were noticed, implying induction of these CYP isozymes by TEQs. On the other hand, there was no significant positive correlation between muscle TEQ and any one of analyzed CYP isozyme expression levels. CYP1A- and CYP3A-like protein expression levels represented better correlations with pentoxy- and benzyloxyresorufin-O-dealkylase activities rather than methoxy- and ethoxyresorufin-O-dealkylase activities, indicating unique catalytic functions of these CYPs in JCs. Furthermore, we succeeded in isolating CYP1A5 cDNA from the liver of JC, having an open reading frame of 531 amino acid residues with a predicted molecular mass of 60.3 kDa. JC CYP1A5 mRNA expression measured by real-time RT-PCR had a significant positive correlation with hepatic TEQs, suggesting induction of CYP1A5 at the transcriptional level. Ratios of several Co-PCB congeners to CB-169 in the liver of JCs revealed significant negative correlations with CYP1A protein or CYP1A5 mRNA expression levels, implying metabolism of these congeners by the induced CYP1A. The liver/breast muscle concentration (L/M) ratios of PCDDs/DFs and CB-169 increased with an increase in hepatic CYP1A protein or CYP1A5 mRNA expression levels, suggesting congener-specific hepatic sequestrations by the induced CYP1A. The present study provides insights into the propensity of CYP1A induction to the exposure of dioxin-like chemicals, and unique metabolic and sequestration capacities of CYP1A in JC.
Asunto(s)
Hidrocarburo de Aril Hidroxilasas/biosíntesis , Cuervos/metabolismo , Dioxinas/metabolismo , Hígado/efectos de los fármacos , Hígado/enzimología , Oxidorreductasas/biosíntesis , ARN Mensajero/metabolismo , Secuencia de Aminoácidos , Animales , Hidrocarburo de Aril Hidroxilasas/genética , Secuencia de Bases , Benzofuranos/análisis , Benzofuranos/metabolismo , Benzofuranos/toxicidad , Dioxinas/análisis , Dioxinas/toxicidad , Inducción Enzimática/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Masculino , Microsomas Hepáticos/química , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , Datos de Secuencia Molecular , Músculo Esquelético/química , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/enzimología , Oxidorreductasas/genética , Bifenilos Policlorados/análisis , Bifenilos Policlorados/metabolismo , Bifenilos Policlorados/toxicidad , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análisis , Dibenzodioxinas Policloradas/metabolismo , Dibenzodioxinas Policloradas/toxicidad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Genética/efectos de los fármacosRESUMEN
To assess the significance of waste dumping sites as a source of chemical contamination to ecosystems, we analyzed the residue levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and other organochlorines in the breast muscle of crows from a dumping site in the south of Chennai city, South India. Crows from the dumping site contained significantly higher total TEQs (60 +/- 27 pg/g lipid wt) than those from the reference sites (26 +/- 18 pg/g lipid wt). Especially, certain dioxin-like coplanar PCB congeners (Co-PCBs), such as CB-77 and CB-105, whose source is commercial PCBs,were significantly higher in crows from the dumping site than those from the reference sites. Profiles of PCDDs/DFs and Co-PCBs in crows from the dumping site were similar to those of soil at the same site, which was confirmed by principal component analysis. Furthermore, significant positive correlations were obtained between the congener-specific bioconcentration factors (BCFs) of PCDDs/DFs estimated from concentrations in crows and soil from the dumping site and the theoretical BCFs calculated from water-particle and lipid-water partitioning coefficients. On the other hand, the estimated BCFs had significant negative correlations with the molecular weight of PCDDs/DFs, indicating that molecular size limits their bioaccumulation. These results suggest that dioxin-like congeners in the soil of the dumping site were transferred directly to the crows through the ingestion of on-site garbage contaminated with soil, rather than through trophic transfer in the ecosystem. The present study provides insight into the ecological impacts of dumping sites.
Asunto(s)
Cuervos/metabolismo , Dioxinas/farmacocinética , Monitoreo del Ambiente/estadística & datos numéricos , Hidrocarburos Clorados/farmacocinética , Eliminación de Residuos , Contaminantes del Suelo/análisis , Animales , Cromatografía de Gases y Espectrometría de Masas , India , Músculo Esquelético/química , Análisis de Componente Principal , Estadísticas no ParamétricasRESUMEN
The present study examines the effects of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs) on hepatic cytochromes P450 (CYP) in the wild population of common cormorants from Lake Biwa, Japan, and discusses functional roles of CYP1A in terms of correlation analysis between tissue concentrations of individual congeners and expression levels of CYP1A. Levels of alkoxyresorufin (methoxy-, ethoxy-, pentoxy-, and benzyloxyresorufin) O-dealkylase activities and a protein cross-reacted with anti-rat CYP1A1 polyclonal antibodies showed significant positive correlations with total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) or TEQs for most individual congeners in the liver of cormorants, suggesting induction of CYP1A-like protein by these chemicals. In contrast, TEQs for lower chlorinated congeners, 2,3,7,8-T4CDF and PCB77, showed relatively low correlations with the expression level of CYP1A-like protein. Concentrations of 2,3,7,8-T4CDF and PCB77 normalized to a relatively recalcitrant congener, PCB169, were negatively correlated with the CYP1A-like protein level. These results indicate preferential metabolism of those congeners by CYP1A-like protein that was induced by TEQs. Concentration ratios of liverto pectoral muscle for certain congeners significantly increased with an elevation of the CYP1A-like protein level. Comparing the results in the present study with those of previous studies using rodents treated with certain dioxin-like congeners, these congeners in the liver may be sequestered by CYP1A. Levels of cross-reactive proteins with anti-rat CYP2B1, CYP2C6, and CYP3A2 polyclonal antibodies correlated with neither TEQs nor liver/muscle concentration ratios of congeners. We conclude that the potential for CYP1A induction, and metabolism and sequestration of dioxin-like compounds by CYP1A, may be a critical factor for assessing the ecological risk in wild avian species.
Asunto(s)
Benzofuranos/metabolismo , Aves/metabolismo , Sistema Enzimático del Citocromo P-450/biosíntesis , Bifenilos Policlorados/metabolismo , Dibenzodioxinas Policloradas/análogos & derivados , Animales , Benzofuranos/análisis , Benzofuranos/toxicidad , Sistema Enzimático del Citocromo P-450/metabolismo , Dibenzofuranos Policlorados , Inducción Enzimática , Femenino , Agua Dulce , Japón , Hígado/química , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Microsomas Hepáticos/enzimología , Bifenilos Policlorados/análisis , Bifenilos Policlorados/toxicidad , Dibenzodioxinas Policloradas/análisis , Dibenzodioxinas Policloradas/metabolismo , Dibenzodioxinas Policloradas/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/toxicidadRESUMEN
Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs) were determined in the liver and pectoral muscle of common cormorants (Phalacrocorax carbo) collected from Lake Biwa, Japan. To clarify the toxicokinetic behaviors and potential toxicities of these chemicals, the present study addresses life-stage- and tissue-specific accumulation of the congeners. Total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) were in the range of 360 to 50,000 pg/g lipid weight in the liver and 310 to 12,000 pg/g lipid weight in the pectoral muscle. Among congeners, for which toxic equivalency factors were assigned, PCB126, 2,3,4,7,8-P5CDF, and 1,2,3,7,8-P5CDD made a greater contribution to total TEQs in the liver. Hepatic concentrations of T4- to H6CDDs, P5- and H6CDFs, and Co-PCBs (except PCB77) significantly increased with growth of cormorants, leading to life-stage-related compositional changes. The concentration ratios of liver to pectoral muscle revealed preferential accumulation of higher chlorinated congeners in hepatic tissue. For most congeners, concentration ratios significantly increased with an increase in hepatic total TEQs, suggesting their concentration-dependent hepatic sequestration. These results imply the presence of hepatic binding protein(s) such as cytochrome P450, inducible by these chemicals, which mayfunction as a binding species different from aryl hydrocarbon receptor. On the basis of these results, we conclude that the toxicokinetic behavior of each congener is life-stage-, tissue-, and concentration-dependent. TEQs in wildlife populations exposed to multiple congeners with varying concentrations should be used with caution for risk assessment, even within a species.
Asunto(s)
Aves/metabolismo , Monitoreo del Ambiente , Hígado/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Dibenzodioxinas Policloradas/análogos & derivados , Contaminantes Químicos del Agua , Animales , Benzofuranos/farmacocinética , Benzofuranos/toxicidad , Dibenzofuranos Policlorados , Japón , Hígado/metabolismo , Músculo Esquelético/metabolismo , Bifenilos Policlorados/farmacocinética , Bifenilos Policlorados/toxicidad , Dibenzodioxinas Policloradas/farmacocinética , Dibenzodioxinas Policloradas/toxicidad , Distribución Tisular , Contaminantes Químicos del Agua/farmacocinética , Contaminantes Químicos del Agua/toxicidadRESUMEN
Sero-prevalences of canine distemper virus (CDV), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) were evaluated in 20 captive lions in two Japanese zoos. Anti-CDV antibody was detected in 13 of 20 lions. We could pursue antibody responses against CDV in three lions back to 1996. Sera collected in 1996 were negative for anti-CDV antibody, therefore, all of them showed sero-conversion in 2000. This result suggested that the epidemic of CDV infection in this zoo might have happened between 1996 and 2000. The lions were also examined for FIV and FeLV infections. We had no evidence for FeLV infection but eight lions were sero-positive for anti-FIV antibody.