We are grateful to Ms. Kaori Shimizu and Mr. Masaki Takasu of the Graduate School of Life Sciences, Toyo University, for their technical support. This project was supported by research grants from the Special Research Foundation and Bio-Nano Electronics Research Centre of Toyo University (to SK); by the Science Research Promotion Fund of the Promotion and Mutual Aid Corporation for Private Schools of Japan (to SK); by the New Project Fund for Risk Assessments, from the Ministry of Economy, Trade and Industry (to SK); by a Grant-in-Aid for Challenging Exploratory Research (award 23651028 to SK); by a Grant-in-Aid for Scientific Research (B) and (C) (award 23310026 and 26340030 to SK); and by a Grant-in-Aid for Strategic Research Base Project for Private Universities (award S1411016 to SK) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

Os medaka japoneses utilizados neste estudo foram tratados de forma humana, em conformidade com as diretrizes institucionais da Universidade de Toyo, com a devida consideração para o alívio do sofrimento e desconforto. 1. Prata nanocolóides (SNCs) <ol><li> Comprar SNCs purificadas (20 mg / L-1, 99,99% de pureza, de partículas de diâmetro médio cerca de 28,4 ± 8,5 nm, suspensas em água destilada). </li><li> Validar a pureza e concentração da prata por espectrometria de massa com plasma acoplado indutivamente (ICP-MS) para análises de acordo com o manual de funcionamento 8. O método de pré-tratamento para ICP-MS análises está descrito no capítulo 7. </li></ol> 2. Preparação de SNC Solutions (misturas de prata Colloids e Ag +) com diferentes salinidades <ol><li> Preparar 60 × MTC que consiste em 60 g de NaCl, 1,8 g de KCl, 2,4 g de CaCl 2 2H 2 O, e 9,78 g de MgSO 4 · 7H 2 O em 1 L de ultágua rapure; ajustar o pH para 7,0 com 1,25% de NaHCO3 em água ultrapura. </li><li> Agita-se a solução MTC a 25 ° C durante a noite. </li><li> Misture SNCs com ERM diluída. Prepare 40 ml de cada solução mista SNC-ERM. A concentração final é de 10 mg / L-1 de SNCs em diferentes concentrações de ERM (1x, 5x, 10x, 15x, 20x, ou 30x). </li><li> Ajustar o pH da solução mista SNC-MTC para 7,0 com 0,625% de NaHCO3 em água ultrapura. ajuste do pH é muito importante na preparação da solução SNC, porque Ag + de libertação é facilitada por condições acídicas 9. </li><li> Use AgNO 3 como composto de referência para SNCs. <ol><li> Misture AgNO3 com ERM diluído. Preparar 40 ml de AgNO3 -ERM solução mista a uma concentração de AgNO3 de 15,7 mg / L-1 (10 mg / L de prata -1) em diferentes concentrações de ERM (1x, 5x, 10x, 15x, 20x, ou 30x) . Nota: Para examinar a toxicidade colóide de prata, AgNO3solução, que é uma fonte de prata solúvel, é usado como composto de referência para SNCs, que são uma mistura de colóides de prata e prata solúvel. </li></ol></li></ol> 3. Medaka cultura e colheita Egg <ol><li> Obter o medaka (O. latipes) (estirpe vermelho-alaranjado) (60 homens e 60 mulheres). </li><li> medaka cultura como grupos (20 homens e 20 mulheres como um grupo) em ERM 1x em 3 tanques L, usando um sistema de cultura flow-through medaka. <ol><li> Cultura nas seguintes condições: intervalo de pH do meio de cultura: 6,2-6,5 luz: ciclo escuro: 16: 8 hr temperatura do meio de cultura: 24 ° C ± 0,5 pressão osmótica do meio de cultura: 257 mOsm </li></ol></li><li> Alimente medaka sobre náuplios de Artemia salina às 10:00 (uma vez por dia) e alimentar uma dieta de peixe seco artificial às 09:00, 11:00, 13:00, 15:00 e 17:00 (cinco vezes por dia). <ol><li> Obter A. náuplios salina. </li> &lt;li&gt; Prepare 5 L de uma solução de sal de 3,0% num copo de plástico. </li><li> Adicionar 30 g de ovos de artémia para a solução do sal contido no copo. </li><li> Incubar os ovos a 25 ° C durante 48 horas com borbulhamento (4 L / min -1) usando uma bomba de arejamento. </li><li> Após 48 h, parar o borbulhamento. </li><li> Deixar a solução repousar durante 5 a 10 min para separar o A. eclodidos salina náuplios (parte inferior da solução) a partir de ovos não eclodidos e cascas de ovos (parte superior da solução). </li><li> Remover a camada superior da solução por decantação. </li><li> Filtra-se a porção inferior da solução através de um peneiro com aberturas de 283 um, e recolher os náuplios que passam através de uma rede com aberturas de 198 ^ m. </li><li> Alimente o náuplios aos medaka dentro de 6 horas. </li></ol></li><li> Após as medaka do sexo feminino têm gerado, remover os aglomerados de ovos externos suavemente de corpos das fêmeas ou recolher os ovos a partir do fundo do tanque de peixes usando um smtoda a rede (net tamanho 5 cm x 5 cm, tamanho do furo 0,2 mm x 0,2 mm). </li><li> Lavar o cluster de ovo com água corrente da torneira por 5 s. </li><li> Adicione todos os aglomerados de ovos lavados 30x solução ERM. </li><li> Remover os clusters a partir da solução após 1 min e colocar os aglomerados de ovos entre toalhas de papel seco e rolar suavemente. </li><li> Coloque os ovos de volta para o ERM 30x. </li><li> Seleccionar ovos fertilizados sob um microscópio de dissecação. </li><li> Lugar seleccionado 810 ovos em ERM 1x em seis poços placas de plástico usando uma pinça. </li><li> Incubar os ovos a 25 ± 0,1 ° C em uma incubadora até que estágio de desenvolvimento 21. (estádios de desenvolvimento dos embriões medaka foram definidos a partir do trabalho de Iwamatsu 10). </li><li> Escolher ovos incubados no estágio de desenvolvimento 21 sob um microscópio de dissecação. </li><li> Lavar os ovos selecionados com ERM 1x. </li><li> Sujeitar os ovos lavados para experimentos de exposição (Seção 4). </li></ol> 4. Ensaios de Toxicidade de SNCs ou AgNO3 </sub&gt; Em diferentes salinidades ERM <ol><li> Lavar os ovos medaka (fase 21), três vezes com solução de ensaio [SNCs (10 mg / L-1) ou AgNO 3 (15,7 mg / L-1 como de 10 mg / L de prata -1) para cada concentração de MTC (1x, 5x , 10x, 15x, 20x, ou 30x) a pH 7]. Como controlos, usam ovos em 1 × a 30 × MTC a um pH de 7. </li><li> Adicionar 15 ovos enxaguados a 5 ml de cada solução de teste em seis-se placas de plástico. (Execute os experimentos de exposição três vezes por SNC ou AgNO3 toxicidade testando o uso de cada solução de teste.) </li><li> Enrole as placas em folha de alumínio. </li><li> Incubar as placas revestidas apresentam um de 25 ° C no escuro até à eclosão ou durante 14 dias. </li><li> Observar os ovos expostos a cada 24 horas para mudanças biológicas e ovos mortos (Figuras 1 e 2). </li><li> Trocar as soluções de teste a cada 24 horas. </li><li> Realizar observações como se segue. <ol><li> No dia 6 de exposição, contar o ritmo cardíaco (por 15 segundos) of embriões medaka sob um microscópio de dissecação, utilizando um cronometro (Figura 3A). </li><li> No dia 6 de exposição, medir o tamanho do olho (diâmetro) de embriões medaka sob um microscópio de dissecação, usando um micrómetro (Figura 3b). </li><li> No dia incubação, medir os comprimentos de corpo inteiro de larvas sob um microscópio de dissecação, utilizando um micrômetro (Figura 3c). </li><li> Contar o número total de ovos que eclodem expostos ao longo dos 14 dias (Figura 3D). </li></ol></li></ol> 5. Isolamento de prata solúvel de Solução SNC, e análise de prata <ol><li> Isolar prata solúveis a partir de cada solução SNC (uma mistura de colóides de prata e prata solúvel) por filtração através de um filtro de membrana de 3 kDa a 14.000 x g e 4 ° C durante 10 min. Usar um filtro de membrana de 3 kDa, para isolar prata solúvel dos SNCs, porque o diâmetro médio de relatado SNCs agregados no MTC 1x é 67,8 nm, 11 umnd a de Ag + é 0,162 nm 12; a membrana de 3 kDa, exclui partículas com diâmetros de 2 nm ou mais 13. </li><li> Medir a concentração de prata em 50 ml de solução filtrada (= a concentração de prata solúvel) por análise de ICP-MS (Figura 3e) de acordo com o manual de instruções ICP-MS 8. O método de pré-tratamento para o ICP-MS análises está descrito no capítulo 7. </li></ol> 6. Medição de prata bioacumulação em Medaka Embriões <ol><li> Expor ovos medaka (fase 21) para SNCs ou AgNO3 como descrito na seção 4. </li><li> No dia 6 de exposição, remover cório do ovo (isto é, dechorion) usando Medaka incubação da enzima de acordo com o protocolo descrito no Livro Medaka 14. </li><li> Medir a concentração de prata dos ovos dechorioned pela análise ICP-MS de acordo com o ICP-MS manual de operação 8 (Figura 3-F). o pré-tratamentométodo para a ICP-MS análises está descrito no capítulo 7. </li></ol> 7. Medição de Concentração de prata pelo ICP-MS Análise <ol><li> Adicione exemplos [50 mL de solução de prata (para validação da concentração de prata, secção 1); três embriões dechorionated (seção 5); ou 50 ml de solução filtrada (seção 5)] para um copo de 50 ml Teflon. </li><li> Adicionar 2,0 ml de ácido nítrico ultrapura ao copo de 50 ml. </li><li> Aquece-se a mistura sobre uma placa quente a 110 ° C, até pouco antes de secar (cerca de 3 h). </li><li> Para dissolver a matéria orgânica por completo, adicionar 2,0 ml de ácido nítrico ultrapura e 0,5 ml de peróxido de hidrogénio para a proveta. </li><li> Aquecer a mistura novamente na chapa quente até pouco antes de ele seca (cerca de 3 horas). </li><li> Dissolve-se o resíduo em 4 ml de solução de ácido nítrico 1,0% ultrapura. </li><li> Transferência de 4 ml de solução para um tubo de centrífuga. </li><li> Repita duas vezes 7,6-7,7 (um total de três vezes). O volume final é de 12,0ml. </li><li> Medir a concentração de prata da amostra (dissolvido em ácido nítrico ultrapura 1,0%) por meio de análise ICP-MS de acordo com o manual de instruções 8. <ol><li> Use uma interna e uma solução padrão externo (Veja Lista de Materiais) para quantificar a concentração de prata. A solução padrão interna e externa é credenciada pela Associação Americana de Acreditação de Laboratórios (A2LA). Os limites de detecção de prata foram 0,0018 ng / ml -1 (solução) e 0,016 ng mg de peso -1 (corpo do embrião). </li></ol></li></ol>

<ol>
	<li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> OECD Guidelines for the Testing of Chemicals, Section 2 Effects on Biotic Systems. , (2015).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> National Coastal Condition Report. , (2001).</li><li>Sakaizumi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+inorganic+salts+on+mercury-compound+toxicity+to+the+embryos+of+the+Medaka,+Oryzias+latipes.">Effect of inorganic salts on mercury-compound toxicity to the embryos of the Medaka, Oryzias latipes.</a> J. Fac. Sci. Univ. Tokyo. 14 (4), 369-384 (1980).</li><li>Sumitani, K., Kashiwada, S., Osaki, K., Yamada, M., Mohri, S., Yasumasu, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Medaka+(Oryzias+latipes)+Embryo+toxicity+of+treated+leachate+from+waste-landfill+sites.">Medaka (Oryzias latipes) Embryo toxicity of treated leachate from waste-landfill sites.</a> J. Jpn. Soc. Waste Manage. Exp. 15 (6), 472-479 (2004).</li><li>Kashiwada, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+of+Nanoparticles+in+the+See-through+Medaka+(Oryzias+latipes).">Distribution of Nanoparticles in the See-through Medaka (Oryzias latipes).</a> EHP. 114 (11), 1697-1702 (2006).</li><li>Iwamatsu, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Integrated Book for the Biology of the Medaka. , (2006).</li><li>Miyamoto, T., Machida, T., Kawashima, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+environmental+salinity+on+the+development+of+chloride+cells+of+freshwater+and+brackish-water+medaka,+Oryzias+latipes.">Influence of environmental salinity on the development of chloride cells of freshwater and brackish-water medaka, Oryzias latipes.</a> Zoo. Sci. 3 (5), 859-865 (1986).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> XSERIES 2 ICP-MS Getting Started Guide Revision B - 121 9590. , (2007).</li><li>Kashiwada, S., Ariza, M. E., Kawaguchi, T., Nakagame, Y., Jayasinghe, B. S., Gartner, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver+nanocolloids+disrupt+medaka+embryogenesis+through+vital+gene+expressions.">Silver nanocolloids disrupt medaka embryogenesis through vital gene expressions.</a> ES &amp; T. 46 (11), 6278-6287 (2012).</li><li>Iwamatsu, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stages+of+normal+development+in+the+medaka+Oryzias+latipes.">Stages of normal development in the medaka Oryzias latipes.</a> Mech. Dev. 121, 605-618 (2004).</li><li>Kataoka, C., Ariyoshi, T., Kawaguchi, H., Nagasaka, S., Kashiwada, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salinity+increases+the+toxicity+of+silver+nanocolloids+to+Japanese+medaka+embryos.">Salinity increases the toxicity of silver nanocolloids to Japanese medaka embryos.</a> Environ. Sci.: Nano. 2, 94-103 (2014).</li><li>Shannon, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revised+effective+ionic+radii+and+systematic+studies+of+interatomic+distances+in+halides+and+chalcogenides.">Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides.</a> Acta Cryst. 32, 751-767 (1976).</li><li>Wakamatsu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Medaka Book, 6.1: Preparation of hatching enzyme. , (2015).</li></ol>

The authors declare that they have no competing financial interests.

Medaka é um peixe de água doce que é altamente tolerante à água do mar; não é bem conhecido que o habitat natural original este peixe era água salgada ao largo da costa japonesa 6. Assim, peixes medaka ter bem desenvolvida células de cloreto 7. Esta propriedade única fornece aos cientistas uma nova maneira de testar a toxicidade dos produtos químicos no ambiente em função da salinidade (água doce para a água do mar), utilizando apenas uma única espécie de peixe. <p class="jove_...

Desde a criação da Organização para a Cooperação e as diretrizes de teste Desenvolvimento Económico (OCDE) para produtos químicos de teste em 1979, 38 guias do teste foram publicados na Seção 2 das orientações, efeitos sobre os sistemas bióticos 1. Todos os organismos aquáticos testados ter sido de habitats de água doce, ou seja, plantas de água doce; algas; invertebrados, como dáfnias e quironomídeos; e peixes, como medaka, peixe-zebra, e truta arco-íris. Em comparação com ambientes de água salgada, ambientes de água doce estão mais directamente afectados pelas actividades económicas e industriais humanos. Portanto, ambientes de água doce foram priorizados para testes, porque eles estão em maior risco de poluição. Nas zonas costeiras, incluindo estuários, salinidades variam entre as condições de água e água salgada, salobra, e estas áreas são muitas vezes poluída por atividade industrial 2. As zonas costeiras e as suas zonas húmidas associadas são caracterizados por hbiodiversidade ecológica igh e produtividade. ecossistemas costeiros devem, portanto, ser protegido da poluição química. No entanto, tem havido pesquisas ecotoxicológicas em habitats de água e água salgada salobra limitado. Sakaizumi 3 estudaram as interacções entre tóxicos metil-mercúrio e salinidade em ovos medaka japoneses e descobriram que o aumento da pressão osmótica da solução de teste aumentou a toxicidade do mercúrio metilo. . Sumitani et al 4 utilizaram ovos medaka para investigar a toxicidade do lixiviado de aterro sanitário; eles descobriram que a equivalência osmótica de lixiviados para os ovos era a chave para induzir anormalidades durante a embriogênese. Além disso, Kashiwada 5 relataram que as nanopartículas de plástico (39,4 nm de diâmetro) facilmente permeado através do córion medaka ovo em condições salobras (15x embrião criação médio (ERM)). Um modelo pequeno peixe típico, os medaka japonês (Oryzias latipes </em&gt;) tem sido utilizado em biologia básica e ecotoxicology 6. Medaka japonês pode viver em condições que variam de água doce para a água do mar por causa de suas células de cloreto altamente desenvolvidos 7. Eles são, portanto, susceptíveis de ser útil para testar em condições com uma vasta gama de salinidade.

<table border="0" cellpadding="0" cellspacing="0" width="785">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Silver nanocolloids</td>
			<td style="width:188px;">Utopia Silver Supplements</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">NaCl</td>
			<td>Nacalai Tesque, Inc.</td>
			<td style="width:119px;">31319-45</td>
			<td>For making ERM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">KCl</td>
			<td>Nacalai Tesque, Inc.</td>
			<td style="width:119px;">28513-85</td>
			<td>For making ERM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CaCl2&#183;2H2O</td>
			<td>Nacalai Tesque, Inc.</td>
			<td style="width:119px;">06730-15</td>
			<td>For making ERM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MgSO4&#183;7H2O</td>
			<td>Nacalai Tesque, Inc.</td>
			<td style="width:119px;">21002-85</td>
			<td>For making ERM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NaHCO3&#160;</td>
			<td>Nacalai Tesque, Inc.</td>
			<td style="width:119px;">31212-25</td>
			<td>For making ERM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">AgNO3</td>
			<td>Nacalai Tesque, Inc.</td>
			<td style="width:119px;">31018-72</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">pH meter</td>
			<td>HORIBA, Ltd.</td>
			<td style="width:119px;">F-51S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Balance</td>
			<td>Mettler-Toledo International Inc.</td>
			<td style="width:119px;">MS204S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">medaka (Oryzias latipes) orange-red strain&#160;</td>
			<td colspan="2">National Institute for Environmental Studies</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">medaka flow-through culturing system</td>
			<td>Meito Suien Co.</td>
			<td>MEITOsystem</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Artemia salina nauplii eggs</td>
			<td>Japan pet design Co. Ltd</td>
			<td>4975677033759</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">aeration pomp</td>
			<td>Japan pet design Co. Ltd</td>
			<td>non-noise w300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Otohime larval &#946;-1</td>
			<td style="width:188px;">Marubeni Nissin Feed Co. Ltd</td>
			<td style="width:119px;">Otohime larval &#946;-1</td>
			<td>Artificial dry fish diet</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">dissecting microscope</td>
			<td style="width:188px;">Leica microsystems</td>
			<td style="width:119px;">M165FC</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">micrometer</td>
			<td>Fujikogaku, Ltd.</td>
			<td>10450023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">incubator</td>
			<td>Nksystem</td>
			<td>TG-180-5LB</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">shaker</td>
			<td style="width:188px;">ELMI Ltd.</td>
			<td style="width:119px;">Aizkraukles 21-136</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6-well plastic plates</td>
			<td>Greiner CELLSTAR</td>
			<td style="width:119px;">M8562-100EA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">aluminum foil</td>
			<td>AS ONE Co.</td>
			<td style="width:119px;">6-713-02</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">stopwatch</td>
			<td>DRETEC Co. Ltd.</td>
			<td style="width:119px;">SW-111YE</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">3-kDa membrane filter</td>
			<td>EMD Millipore Corporation</td>
			<td colspan="2">0.5-mL centrifugal-type filter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">50-mL Teflon beaker</td>
			<td>AS ONE Co.</td>
			<td style="width:119px;">33431097</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Custom claritas standard</td>
			<td style="width:188px;">SPEXertificate</td>
			<td style="width:119px;">ZSTC-538</td>
			<td>For internal standard</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Custom claritas standard</td>
			<td style="width:188px;">SPEXertificate</td>
			<td style="width:119px;">ZSTC-622</td>
			<td>For external standard</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">ultrapure nitric acid</td>
			<td style="width:188px;">Kanto Chemical Co.</td>
			<td style="width:119px;">28163-5B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">hydrogen peroxide&#160;</td>
			<td style="width:188px;">Kanto Chemical Co.</td>
			<td style="width:119px;">18084-1B</td>
			<td>for atomic absorption spectrometry</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">ICP-MS</td>
			<td>Thermo Scientific</td>
			<td colspan="2">Thermo Scientific X Series 2&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">hot plate</td>
			<td>Tiger Co.</td>
			<td>CRC-A300</td>
			<td></td>
		</tr>
	</tbody>
</table>

salinity-dependent toxicity assay of silver nanocolloids using medaka eggs

A salinidade constitui uma característica importante do ambiente aquático. Para os organismos aquáticos que define os habitats de água doce, água salobra e água do mar. Os testes de toxicidade dos produtos químicos e avaliações de seus riscos ecológicos para os organismos aquáticos são freqüentemente realizada em água doce, mas a toxicidade dos produtos químicos para os organismos aquáticos depende do pH, temperatura e salinidade. Não existe um método, no entanto, para testar a dependência salinidade de toxicidade para os organismos aquáticos. Aqui, usamos medaka (Oryzias latipes), porque eles podem se adaptar à água doce, água salobra e água do mar. Diferentes concentrações do meio de criação de embriões (ERM) (1x, 5x, 10x, 15x, 20x e 30x) foram empregadas para testar a toxicidade de partículas nanocolloidal prata (SNCs) para Medaka ovos (ERM 1x e 30x ERM têm pressões osmóticas equivalentes à água doce e água do mar, respectivamente). Em placas de seis poços de plástico, de 15 ovos medaka, em triplicado, foram expostas a SNCs a 10 mg / L &amp;# 8722; 1 em diferentes concentrações de MTC a pH 7 e 25 ° C no escuro. Foi utilizado um microscópio de dissecação e um micrômetro para medir a frequência cardíaca por 15 seg e olho de diâmetro no dia 6 e comprimento do corpo cheio de larvas em incubação dia (secção 4). Os embriões foram observados até a eclosão ou dia 14; Em seguida, contou a taxa de eclosão todos os dias, durante 14 dias (Seção 4). Para ver a acumulação de prata em embriões, que usamos em espectrometria de massa com plasma para medir a concentração de prata de soluções de teste (seção 5) e embriões dechorionated (secção 6) .A toxicidade dos SNCs para embriões medaka, obviamente, aumentou com o aumento da salinidade. Este novo método permite-nos testar a toxicidade dos produtos químicos em diferentes salinidades.

O efeito da salinidade na toxicidade SNC foi muito óbvio: a indução de morte ou deformidade foi salinidade dependentes (Figuras 1 e 2). Nós medimos biomarcadores fenotípicas (frequência cardíaca, tamanho do olho, comprimento de corpo inteiro, e taxa de eclosão) no SNC (10 mg / L -1) embriões -exposed. Esses biomarcadores fenotípicas revelou dependente da salinidade toxicidade SNC. <p class="jove_content" fo:keep-together.within-p...

Watch this Scientific Journal Video about Salinity-dependent Toxicity Assay of Silver Nanocolloids Using Medaka Eggs at JoVE.com

Salinity-dependent Toxicity Assay of Silver Nanocolloids Using Medaka Eggs

Embryonic stages are the most susceptible to xenobiotics. Although chemical toxicity depends on salinity, no method exists to test the salinity dependence of toxicity to aquatic organisms. Here, we describe a new and high-throughput method for determining the salinity dependence of toxicity to aquatic embryos.

dependente da salinidade toxicidade Ensaio de prata nanocolóides Usando Medaka Eggs

Salinity is an important characteristic of the aquatic environment. For aquatic organisms it defines the habitats of freshwater, brackish water, and ...

salinity-dependent-toxicity-assay-silver-nanocolloids-using-medaka

Research

JoVE Journal

Developmental Biology

7.9K visualizações.  Toyo University. Embryonic stages are the most susceptible to xenobiotics. Although chemical toxicity depends on salinity, no method exists to test the salinity dependence of toxicity to aquatic organisms. Here, we describe a new and high-throughput method for determining the salinity dependence of toxicity to aquatic embryos.

Vídeo: Salinity-dependent Toxicity Assay of Silver Nanocolloids Using Medaka Eggs

Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation

Efficient protocols to differentiate human pluripotent stem cells to various tissues in combination with -omics technologies opened up new horizons for in vitro toxicity testing of potential drugs. To provide a solid scientific basis for such assays, it will be important to gain quantitative information on the time course of development and on the underlying regulatory mechanisms by systems biology approaches. Two assays have therefore been tuned here for these requirements. In the UKK test system, human embryonic stem cells (hESC) (or other pluripotent cells) are left to spontaneously differentiate for 14 days in embryoid bodies, to allow generation of cells of all three germ layers. This system recapitulates key steps of early human embryonic development, and it can predict human-specific early embryonic toxicity/teratogenicity, if cells are exposed to chemicals during differentiation. The UKN1 test system is based on hESC differentiating to a population of neuroectodermal progenitor (NEP) cells for 6 days. This system recapitulates early neural development and predicts early developmental neurotoxicity and epigenetic changes triggered by chemicals. Both systems, in combination with transcriptome microarray studies, are suitable for identifying toxicity biomarkers. Moreover, they may be used in combination to generate input data for systems biology analysis. These test systems have advantages over the traditional toxicological studies requiring large amounts of animals. The test systems may contribute to a reduction of the costs for drug development and chemical safety evaluation. Their combination sheds light especially on compounds that may influence neurodevelopment specifically.

The protocols describe two in vitro developmental toxicity test systems (UKK and UKN1) based on human embryonic stem cells and transcriptome studies. The test systems predict human developmental toxicity hazard, and may contribute to reduce animal studies, costs and the time required for chemical safety testing.

Human células estaminais pluripotentes Baseado Developmental Toxicity Ensaios para Química Triagem e Safety Systems Biology Data Generation

Efficient protocols to differentiate human pluripotent stem cells to various tissues in combination with -omics technologies opened up new horizons for in ...

Biologia do Desenvolvimento

Comprehensive Assessment of Germline Chemical Toxicity Using the Nematode Caenorhabditis elegans

Identifying the reproductive toxicity of the thousands of chemicals present in our environment has been one of the most tantalizing challenges in the field of environmental health. This is due in part to the paucity of model systems that can (1) accurately recapitulate keys features of reproductive processes and (2) do so in a medium- to high-throughput fashion, without the need for a high number of vertebrate animals.
We describe here an assay in the nematode C. elegans that allows the rapid identification of germline toxicants by monitoring the induction of aneuploid embryos. By making use of a GFP reporter line, errors in chromosome segregation resulting from germline disruption are easily visualized and quantified by automated fluorescence microscopy. Thus the screening of a particular set of compounds for its toxicity can be performed in a 96- to 384-well plate format in a matter of days. Secondary analysis of positive hits can be performed to determine whether the chromosome abnormalities originated from meiotic disruption or from early embryonic chromosome segregation errors. Altogether, this assay represents a fast first-pass strategy for the rapid assessment of germline dysfunction following chemical exposure.

Comprehensive Assessment of Germline Chemical Toxicity Using the Nematode Caenorhabditis elegans

We describe the detailed steps of a high-throughput chemical assay in the nematode Caenorhabditis elegans used to assess germline toxicity. In this assay, disruption of germline function following chemical exposure is monitored using a fluorescent reporter specific to aneuploid embryos.

Avaliação Compreensiva de Germline Chemical Toxicity Usando o Nemátodo<em&gt; Caenorhabditis elegans</em

Identifying the reproductive toxicity of the thousands of chemicals present in our environment has been one of the most tantalizing challenges in the ...

Method of Studying Palatal Fusion using Static Organ Culture

Cleft lip and palate are among the most common of all birth defects. The secondary palate forms from mesenchymal shelves covered with epithelium that adheres to form the midline epithelial seam (MES). The theories suggest that MES cells follow an epithelial to mesenchymal transition (EMT), apoptosis and migration, making a fused palate 1. Complete disintegration of the MES is the final essential phase of palatal confluence with surrounding mesenchymal cells. We provide a method for palate organ culture. The developed in vitro protocol allows the study of the biological and molecular processes during fusion. The applications of this technique are numerous, including evaluating responses to exogenous chemical agents, effects of regulatory and growth factors and specific proteins. Palatal organ culture has a number of advantages including manipulation at different stages of development that is not possible using in vivo studies.

Studies of palate development are motivated by the incidence of cleft palate, a birth defect that imposes a tremendous health burden and can leave lasting disfigurement. We demonstrate here a technique to culture palatal shelves that can be used to study different signaling pathways involved in palatal development and fusion.

Método de Estudar Palatal Fusão usando estático Órgão Cultura

Cleft lip and palate are among the most common of all birth defects. The secondary palate forms from mesenchymal shelves covered with epithelium that ...

Epicardial Outgrowth Culture Assay and Ex Vivo Assessment of Epicardial-derived Cell Migration

A single layer of epicardial cells lines the heart, providing paracrine factors that stimulate cardiomyocyte proliferation and directly contributing cardiovascular progenitors during development and disease. While a number of factors have been implicated in epicardium-derived cell (EPDC) mobilization, the mechanisms governing their subsequent migration and differentiation are poorly understood. Here, we present in vitro and ex vivo strategies to study EPDC motility and differentiation. First, we describe a method of obtaining primary epicardial cells by outgrowth culture from the embryonic mouse heart. We also introduce a detailed protocol to assess three-dimensional migration of labeled EPDC in an organ culture system. We provide evidence using these techniques that genetic deletion of myocardin-related transcription factors in the epicardium attenuates EPDC migration. This approach serves as a platform to evaluate candidate modifiers of EPDC biology and could be used to develop genetic or chemical screens to identify novel regulators of EPDC mobilization that might be useful for cardiac repair.

Epicardial Outgrowth Culture Assay and Ex Vivo Assessment of Epicardial-derived Cell Migration

Here, we describe methods for isolating primary mouse epicardial cells by an outgrowth culture assay and assessing the functional migration of epicardial-derived cells (EPDC) using an ex vivo heart culture system. These protocols are suitable for identifying genetic and chemical modulators of epicardial epithelial-to-mesenchymal transition (EMT) and motility.

Epicárdio Conseqüência Cultura Ensaio e<em&gt; Ex Vivo</em&gt; Avaliação da migração celular Epicárdica derivado

A single layer of epicardial cells lines the heart, providing paracrine factors that stimulate cardiomyocyte proliferation and directly contributing ...

Drug Treatment and In Vivo Imaging of Osteoblast-Osteoclast Interactions in a Medaka Fish Osteoporosis Model

Bone-forming osteoblasts interact with bone-resorbing osteoclasts to coordinate the turnover of bone matrix and to control skeletal homeostasis. Medaka and zebrafish larvae are widely used to analyze the behavior of bone cells during bone formation, degeneration, and repair. Their optical clarity allows the visualization of fluorescently labeled bone cells and fluorescent dyes bound to the mineralized skeletal matrix. Our lab has generated transgenic medaka fish that express the osteoclast-inducing factor Receptor Activator of Nuclear-factor &#954;B Ligand (RANKL) under the control of a heat&#160;shock-inducible promoter. Ectopic expression of RANKL results in the excess formation of activated osteoclasts, which can be visualized in reporter lines with nlGFP expression under the control of the cathepsin K (ctsk) promoter. RANKL induction and ectopic osteoclast formation leads to severe osteoporosis-like phenotypes. Compound transgenic medaka lines that express ctsk:nlGFP in osteoclasts, as well as mCherry under the control of the osterix (osx) promoter in premature osteoblasts, can be used to study the interaction of both cell types. This facilitates the in vivo observation of cellular behavior under conditions of bone degeneration and repair. Here, we describe the use of this system to test a drug commonly used in human osteoporosis therapy and describe a protocol for live imaging. The medaka model complements studies in cell culture and mice, and offers a novel system for the in vivo analysis of drug action in the skeletal system.

Drug Treatment and In Vivo Imaging of Osteoblast-Osteoclast Interactions in a Medaka Fish Osteoporosis Model

Small laboratory fish have become popular models for bone research on the mechanisms underlying human bone disorders and for the screening of bone-modulating drugs. In this report, we describe a protocol to assess the effect of alendronate on bone cells in medaka larvae with osteoporotic lesions.

Tratamento de drogas e<em&gt; In Vivo</em&gt; Imagem de Osteoblast-osteoclastos Interações em um modelo de Medaka Peixe Osteoporose

Bone-forming osteoblasts interact with bone-resorbing osteoclasts to coordinate the turnover of bone matrix and to control skeletal homeostasis. Medaka ...

Incorporating Pericytes into an Endothelial Cell Bead Sprouting Assay

Angiogenesis is the growth of new vessels from pre-existing vasculature and is an important component of many biological processes, including embryogenesis and development, wound healing, tumor growth and metastasis, and ocular and cardiovascular diseases. Effective in vitro models that recapitulate the biology of angiogenesis are needed to appropriately study this process and identify mechanisms of regulation that can be ultimately targeted for novel therapeutic strategies. The bead angiogenesis assay has been previously demonstrated to recapitulate the multiple stages of endothelial sprouting in vitro. However, a limitation of this assay is a lack of endothelial &#8211; mural cell interactions, which are key to the molecular and phenotypic regulation of endothelial cell function in vivo. The protocol given here presents a methodology for the incorporation of mural cells into the bead angiogenesis assay and demonstrates a tight association of endothelial cells and pericytes during sprouting in vitro. The protocol also details a methodology for effective silencing of target genes using siRNA in endothelial cells for mechanistic studies. Altogether, this protocol provides an in vitro assay that more appropriately models the diverse cell types involved in sprouting angiogenesis, and provides a more physiologically-relevant platform for therapeutic assessment and novel discovery of mechanisms of angiogenesis regulation.

This protocol presents a novel in vitro bead assay that more appropriately models the process of in vivo sprouting angiogenesis by incorporating pericytes. This modification enables the bead assay to more faithfully recapitulate the heterotypic cellular interactions between endothelial cells and mural cells that are critical for angiogenesis.

Incorporando um grânulo de célula endotelial brotando ensaio pericitos

Angiogenesis is the growth of new vessels from pre-existing vasculature and is an important component of many biological processes, including ...

HUVEC Tube-formation Assay to Evaluate the Impact of Natural Products on Angiogenesis

Angiogenesis is a phenomenon that includes different processes, such as endothelial cell proliferation, differentiation, and migration, that lead to the formation of new blood vessels and involve several signal transduction pathways. Here we show that the tube formation assay is a simple in vitro method to evaluate the impact of natural products on angiogenesis and to investigate the molecular mechanisms involved. In particular, in the presence of the water extract of Ruta graveolens (RGWE), endothelial cells are no longer able to form a cell-cell network and that the RGWE effects on human umbilical vein endothelial cell (HUVEC) tube formation is abolished by the constitutive activation of MEK.

Here, we evaluate the effects of the water extract of Ruta graveolens on vessel network formation by using a tube formation assay on a gelled basement matrix.

Tubo HUVEC-ensaio de formação para avaliar o impacto dos produtos naturais na angiogênese

Angiogenesis is a phenomenon that includes different processes, such as endothelial cell proliferation, differentiation, and migration, that lead to the ...

Injecting Gryllus bimaculatus Eggs

Altering gene function in a developing organism is central to different kinds of experiments. While tremendously powerful genetic tools have been developed in traditional model systems, it is difficult to manipulate genes or messenger RNA (mRNA) in most other organisms. At the same time, evolutionary and comparative approaches rely on an exploration of gene function in many different species, necessitating the development and adaptation of techniques for manipulating expression outside currently genetically tractable species. This protocol describes a method for injecting reagents into cricket eggs to assay the effects of a given manipulation on embryonic or larval development. Instructions for how to collect and inject eggs with beveled needles are described. This relatively straightforward technique is flexible and potentially adaptable to other insects. One can gather and inject dozens of eggs in a single experiment, and survival rates for buffer-only injections improve with practice and can be as high as 80%. This technique will support several types of experimental approaches including injection of pharmacological agents, in vitro capped mRNA to express genes of interest, double-stranded RNA (dsRNA) to achieve RNA interference, use of clustered regularly interspaced short palindromic repeats (CRISPR) in concert with CRISPR-associated protein 9 (Cas9) reagents for genomic modification, and transposable elements to generate transient or stable transgenic lines.

Injecting Gryllus bimaculatus Eggs

Here we present a protocol to inject cricket eggs, a technique which serves as a foundational method in many experiments in the cricket, including, but not limited to, RNA interference and genomic manipulation.

Injetando ovos de Gryllus bimaculatus

Altering gene function in a developing organism is central to different kinds of experiments. While tremendously powerful genetic tools have been ...

Three-dimensional Angiogenesis Assay System using Co-culture Spheroids Formed by Endothelial Colony Forming Cells and Mesenchymal Stem Cells

Studies in the field of angiogenesis have been aggressively growing in the last few decades with the recognition that angiogenesis is a hallmark of more than 50 different pathological conditions, such as rheumatoid arthritis, oculopathy, cardiovascular diseases, and tumor metastasis. During angiogenesis drug development, it is crucial to use in vitro assay systems with appropriate cell types and proper conditions to reflect the physiologic angiogenesis process. To overcome limitations of current in vitro angiogenesis assay systems using mainly endothelial cells, we developed a 3-dimensional (3D) co-culture spheroid sprouting assay system. Co-culture spheroids were produced by two human vascular cell precursors, endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs) with a ratio of 5 to 1. ECFCs+MSCs spheroids were embedded into type I collagen matrix to mimic the in vivo extracellular environment. A real-time cell recorder was utilized to continuously observe the progression of angiogenic sprouting from spheroids for 24 h. Live cell fluorescent labeling technique was also applied to tract the localization of each cell type during sprout formation. Angiogenic potential was quantified by counting the number of sprouts and measuring the cumulative length of sprouts generated from the individual spheroids. Five randomly-selected spheroids were analyzed per experimental group. Comparison experiments demonstrated that ECFCs+MSCs spheroids showed greater sprout number and cumulative sprout length compared with ECFCs-only spheroids. Bevacizumab, an FDA-approved angiogenesis inhibitor, was tested with the newly-developed co-culture spheroid assay system to verify its potential to screen anti-angiogenic drugs. The IC50 value for ECFCs+MSCs spheroids compared to the ECFCs-only spheroids was closer to the effective plasma concentration of bevacizumab obtained from the xenograft tumor mouse model. The present study suggests that the 3D ECFCs+MSCs spheroid angiogenesis assay system is relevant to physiologic angiogenesis, and can predict an effective plasma concentration in advance of animal experiments.

Three-dimensional co-culture spheroid angiogenesis assay system is designed to mimic the physiologic angiogenesis. Co-culture spheroids are formed by two human vascular cell precursors, ECFCs and MSCs, and embedded in collagen gel. The new system is effective for evaluating angiogenic modulators, and provides more relevant information to the in vivo study.

Sistema tridimensional do ensaio da angiogênese usando spheroids da co-cultura dados forma pela colônia endothelial que dá forma a pilhas e às pilhas de haste mesenchymal

Studies in the field of angiogenesis have been aggressively growing in the last few decades with the recognition that angiogenesis is a hallmark of more ...

In Situ Detection of Ribonucleoprotein Complex Assembly in the C. elegans Germline using Proximity Ligation Assay

Understanding when and where protein-protein interactions (PPIs) occur is critical to understanding protein function in the cell and how broader processes such as development are affected. The Caenorhabditis elegans germline is a great model system for studying PPIs that are related to the regulation of stem cells, meiosis, and development. There are a variety of well-developed techniques that allow proteins of interest to be tagged for recognition by standard antibodies, making this system advantageous for proximity ligation assay (PLA) reactions. As a result, the PLA is able to show where PPIs occur in a spatial and temporal manner in germlines more effectively than alternative approaches. Described here is a protocol for the application and quantification of this technology to probe PPIs in the C. elegans germline.

In Situ Detection of Ribonucleoprotein Complex Assembly in the C. elegans Germline using Proximity Ligation Assay

This protocol demonstrates use of the proximity ligation assay to probe for protein-protein interactions in situ in the C. elegans germline.

In Situ Detection of Ribonucleoprotein Complex Assembly in the C. elegans Germline usando Ensaio de Ligação de Proximidade

Understanding when and where protein-protein interactions (PPIs) occur is critical to understanding protein function in the cell and how broader processes ...