111 |
The potential of biodegradation on 1, 1, 1-trichloro-2, 2-bis (p-chlorophenyl) ethane, based upon co-metabolism of indigenous bacteriaHellebrandt, Aniko January 2010 (has links)
The purpose of this project is to evaluate the potential of a bioreactor system to degrade DDT based upon co-metabolism of indigenous bacteria. The study was performed with soil samples spiked with four different concentrations of DDT. The prepared sludge was circulated at a steady rate of revolution per minute in bioreactors with added M8 solution, cabbage leaf extract and molasses. The experiment was carried out for 7 days and chemical analysis and toxicity testing was accomplished at the beginning and the end of the experiment. The chemical analysis was essential to support the conclusions of the ecotoxicology tests. Ecotoxicology test was performed for the assessment of the toxicity (in terms of bioavailable measures) of the sludge samples, and was carried out with the Ostracodtoxkit sediment toxicity test, with the freshwater benthic crustacean test species Heterocypris incongruens. As part of the project the potential of the bioremediation method phytoremediation have been studied. Brassica Juncea seeds have been cultivated in the soil spiked with four different concentrations of DDT for one month, under stable circumstances. Growth of the plants was measured at the end of the experiment, and a chemical analysis was carried out. A thorough literature review was carried out for both the bioreactor and the phytoremediation experiments in order to obtain information about methods and theoretical background. The ecotoxicology tests and the chemical analysis showed increased p,p’- DDT concentrations in the bioreactors I. and II. at the end of the 7 day experiment, the reasons of which are not known, and require further studies. / -
|
112 |
Acumulação de compostos organoclorados (PCBs, DDTs e HCB) em tecido hepático de delfinídeos (Cetacea, Mammalia) do Estado do Rio de Janeiro / Organochlorine compounds accumulation (PCBs, DDTs and HCB) in hepatic tissue of delphinids (Cetacea, Mammalia) from Rio de Janeiro StateLeticiaà Nadine Alves Legat 25 February 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No decorrer das últimas décadas a pesquisa relacionada à contaminação de organismos marinhos por compostos organoclorados (OCs) se intensificou aliada à utilização de algumas espécies como sentinelas da qualidade ambiental quanto aos poluentes orgânicos. Dentre essas espécies, podem-se destacar os cetáceos, animais que entre outras características possuem grande longevidade, alta porcentagem lipídica em seus tecidos e são predadores de topo de cadeia trófica, tendendo assim a acumular altos níveis de OCs em seus tecidos. O presente estudo teve por objetivo determinar as concentrações de OCs de origem industrial e agrícola (PCBs, HCB e DDTs) em tecido hepático de oito diferentes espécies de cetáceos delfinídeos pertencentes a três distintas áreas oceânicas do Estado do Rio de Janeiro, são elas a região costeira, a plataforma continental e a região oceânica. A determinação foi realizada em cromatógrafo a gás (GC - Agilent 6890) conectado a um espectrômetro de massa (MS - Agilent 5973). Os valores de DDTs (1263617272 ng.g -1 lip.) e PCBs (7648877288 ng.g -1 lip.) aqui encontrados estão entre os mais altos já reportados para o táxon. Em todas as áreas observou-se uma predominância do ΣPCB, seguida do ΣDDT e HCB, em níveis que refletem o caráter fortemente industrial da região analisada. Entre os PCBs, a maior contribuição advém dos hexabifenis, seguida dos hepta e pentabifenis, sendo os congêneres 153, 138 e 180 os principais em todas as áreas. A razão p,pDDE/ΣDp,pDDT foi alta em todas as regiões (0,9), refletindo um input antigo do poluente na área. Foram realizadas correlações entre as concentrações de OCs e os parâmetros biológicos das espécies, como idade, sexo e comprimento total. A transferência placentária de OCs foi analisada em dois pares de fêmea-feto de Sotalia guianensis, mostrando uma maior transferência dos compostos com menor log Kow. Como esperado, foi encontrada uma diferença significativa no perfil de contaminação entre as espécies das diferentes regiões, relacionada à proximidade da fonte, características espécie-específicas e ao arranjo trófico das espécies. / Over the past decades the research on marine organisms contamination by organochlorine compounds (OCs) has been intensified, allied to the utilization of some species as sentinels of the environmental quality related to organic pollutants. Among these species, cetaceans stand out as animals that, between other characteristics, have great longevity, high lipid percentage on their tissues and are top predators in food chains, therefore having the tendency to accumulate high OCs levels in their tissues. The present study aimed to determine OCs concentrations from industrial and agricultural sources (PCBs, HCB and DDTs) in hepatic tissue of eight different species of delphinid cetaceans belonging to three different oceanic areas of Rio de Janeiro State, namely, coastal region, continental shelf and oceanic region. The determination was performed in an Agilent 6890 gas chromatograph (GC) connected to an Agilent 5973 mass spectrometer (MS). DDTs (1263617272 ng.g -1 lip.) and PCBs (7648877288 ng.g -1 lip.) values reported here are amongst the highest values ever reported for the taxon. In all areas ΣPCB predominance was observed, followed by ΣDDT and HCB in levels that reflect the highly industrial character of the analyzed region. Amongst PCBs, the largest contribution comes from hexa biphenyls, followed by hepta and penta biphenyls, being the 153, 138 and 180 the main congeners in all areas. The p,pDDE/ΣDp,pDDT ratio was high in all regions (0,9), reflecting an ancient input of the pollutant in the area. Correlations between OCs concentrations and biologic parameters such as age, sex and total body lenght were performed. OCs placental transfer was analyzed in two Sotalia guianensis mother-fetus pairs, showing a higher transfer of compounds with lower log Kow. As expected, a significant difference was found on the contamination profile between species from the different regions, related to source proximity, species-specific characteristics and the species trophic arrangement.
|
113 |
Exposição a substâncias organocloradas em São Paulo: níveis séricos em doadores de sangue e fatores associados / Exposure to organochlorine substances in São Paulo: serum levels in blood donors and associated factorsFelipe Parra do Nascimento 01 April 2016 (has links)
A utilização de pesticidas organoclorados é motivo de preocupação das entidades ligadas à área de saúde em todo o mundo. Apesar de as formas de contaminação serem bem conhecidas, não há um controle eficaz na fiscalização do seu uso no Brasil. Sabe-se que altos níveis séricos destes compostos nos organismos de seres humanos e animais acarretam sérios problemas de saúde. Tendo em vista essa realidade, foi realizado, em 2009, o Projeto Piloto do I Inquérito Nacional de Populações Expostas a Substâncias Químicas, cujo subprojeto \"doadores de sangue\" teve como objetivo mensurar as concentrações de substâncias químicas no sangue de 547 residentes da região metropolitana de São Paulo, dentre elas os pesticidas organoclorados. Este trabalho teve como objetivos avaliar as concentrações dos pesticidas hexaclorobenzeno (HCB), alfa-HCH, ?-HCH, beta-HCH, beta-HCH, heptacloro, heptacloro epóxido, dieldrin, mirex, o,p\'-DDT, p,p\'-DDT, o,p\'-DDE, p,p\'-DDE, o,p\'-DDD e p,p\'-DDD nesta população e compará-las com as encontradas em outros países e determinar fatores associados aos níveis mais elevados destas substâncias. O método analítico utilizado foi de cromatografia a gás. Os resultados deste estudo indicam que a população adulta de São Paulo não está exposta a níveis preocupantes de pesticidas organoclorados, pois dentre os compostos analisados, apenas o beta-HCH e o p,p\'-DDE tiveram um número significante de amostras acima do limite de quantificação, 10,7% e 31,2% das amostras respectivamente. Quando utilizada a metade do limite de quantificação para substituir os valores abaixo do limite de quantificação do método, o valor médio encontrado para o beta-HCH foi de 0,028 ug/dL e para o p,p\'-DDE foi de 0,045 ug/dL. Este estudo propôs dois modelos multivariados para explicar os fatores associados aos compostos beta-HCH e p,p\'-DDE no sangue dos doadores. Segundo o modelo de Regressão Logística Ordinal Multivariado, os fatores associados a níveis mais altos de beta-HCH foram ter idade entre 26 e 45 anos e ser do sexo feminino. Para o p,p\'-DDE os fatores associados a níveis mais altos foram ter idade entre 26 e 45 anos, ser do sexo feminino e ter trabalhado com pesticidas, enquanto receber renda mensal de 3 a 5 salários mínimos e consumir derivados de origem animal uma ou mais vezes por semana foram associados a níveis mais baixos de p,p\'-DDE. Segundo o modelo de Regressão Linear Múltipla, os fatores associados a níveis mais altos de beta-HCH foram o sexo feminino, ter contato prévio com pesticidas na região agrícola, ter trabalhado com pesticidas em campanhas de saúde pública, ter trabalhado em empresas de capacitores ou transformadores, ter trabalhado em indústrias de solventes clorados, ter renda mensal de 3 a 5 salários mínimos, consumo de carnes uma ou duas vezes por semana e consumo de frutos do mar uma ou duas vezes por semana, enquanto consumo frequente de cerveja e ter renda mensal de 1 a 3 salários mínimos foram associado a níveis menores de beta-HCH. Já para o p,p\'-DDE, os fatores associados a níveis mais elevados foram ser do sexo feminino, ser não branco, ter trabalhado com pesticidas e consumir água de fontes que não sejam minerais ou de rede, enquanto o consumo frequente de bebidas alcoólicas foi associado a níveis mais baixos de p,p\'-DDE / The use of organochlorine pesticides is a cause of concern to the entities of the health field worldwide. Although the ways of contamination are well known, there is no effective surveillance of its use on Brazil. It\'s known that high levels of these compounds on human beings and animals entails serious health problems. Foreseeing this reality, a Pilot study of the 1st National Inquiry of Populations Exposed to Chemical Compounds was carried out in 2009, in a subproject called \"blood donors\" had the objective to measure the concentrations of chemical compounds on serum from 547 residents of the metropolitan area of São Paulo, among them, the organochlorine pesticides. This study had as objectives to evaluate the levels of the pesticides hexachlorobenzene (HCB), alfa-HCH, beta-HCH, beta-HCH, beta-HCH, heptachlor, heptachlor epoxide, dieldrin, mirex, o,p\'-DDT, p,p\'-DDT, o,p\'-DDE, p,p\'-DDE, o,p\'-DDD e p,p\'-DDD on blood donors and compare these with the ones found on other countries and to find out factors associated with higher levels of those compounds in the population. The analytical method used was gas chromatography. The results of this study indicate that, overall, the population in São Paulo is not exposed to high levels of these compounds because of all compounds analyzed, only beta-HCH and p,p\'-DDE had a significative number of samples above the quantification limit, 10,7% and 31,2% of the samples respectively. Using the half of the quantification limit to substitute the values below the quantification limit, the beta-HCH mean level was 0.028 ug/dL and p,p\'-DDE mean level was 0.045 ug/dL. This study proposed two multivariate models to explain the factors associated with beta-HCH and p,p\'-DDE blood levels. According to the Multivariable Ordinal Logistic Regression model, the factors associated with higher levels of beta-HCH were age between 26 and 45 years and female gender. For the p,p\'-DDE, the associated factors with higher levels were age between 26 to 45 years, female gender and previous work with pesticides while having income of 3 to 5 minimum wages and consumption of derivates of animal origin at least once per week were associated to lower levels of p,p\'-DDE. According to the Multiple Linear Regression model, the factors associated with higher levels of beta-HCH were female gender, previous contact with pesticides on agricultural region, working with pesticides on campaigns of public health, in companies of capacitators or transformers, in companies of chlorinated solvents, having income of 3 to 5 minimum wages, consumption of meat once or twice per week, and consumption of seafood once or twice per week, while frequent consumption of beer and income of 1 to 3 minimum wages lead to lower levels of beta-HCH. Factors associated with higher levels of p,p\'-DDE were female gender, being non-white, previous work with pesticides and consumption of water from sources that not mineral or mains, while frequent consumption of alcohol were associated with lower levels of p,p\'-DDE
|
114 |
Estudo multidisciplinar da evolução ambiental do Reservatório de Salto Grande, Americana, SP, a partir de análises multiproxies geoquímicos, de magnetismo ambiental e biológicos (Tecamebas) / Multidisciplinary study of the environmental evolution of the Salto Grande Reservoir, Americana, SP, from analysis of geochemical multiproxies, environmental magnetism and thecamoebiansMisailidis Lerena, Maria Laura 03 October 2016 (has links)
A presente dissertação é um estudo da evolução ambiental do Reservatório de Salto Grande (RSG), Americana, SP, realizado a partir de análises granulométrica, geomagnética, geoquímica (especiação fósforo e carbono, elementos traço, compostos organoclorados e hidrocarbonetos aromáticos policíclicos) e biológica (tecamebas) de amostras de um testemunho sedimentar de 233 cm. Com base nos resultados obtidos, foi possível: 1) avaliar a toxicidade dos sedimentos, de acordo com os valores-guia de qualidade de sedimentos (VGQS) TEL e PEL, fator de enriquecimento (EF) e índice de geoacumulação (Igeo) e 2) identificar cinco fácies sedimentares, ao longo do testemunho. Fácies 1, situada na base do testemunho, é constituída por lama, com baixas concentrações de elementos traço, compostos organoclorados e HPAs, presença de material radicular e ausência de tecamebas. Essa sequência sedimentar pode ser atribuída às unidades de solos e sedimentos depositados na planície aluvial do Rio Atibaia e representa a fase Préreservatório. A partir de 177 cm de profundidade rumo ao topo, passam ocorrer mais quatro fácies, indicativas dos 65 anos de existência do RSG. A Fácies 2 (transição de solo e início do reservatório) caracteriza-se pela presença de lama, com tênue estratificação plana paralela e surgimento de tecamebas (Arcella gibbosa, A. megastoma, Difflugia corona, D. oblonga, D. gramen e Centropyxis discoide aculeata). Nessa fácies não foram detectados sedimentos contaminados, segundo VGQS. Contudo, foi constatado aumento expressivo de HPAs, provavelmente relacionado a queimadas ocorridas no entorno do reservatório. Fácies 3 (Reservatório) é marcada por sucessão de camadas de lama escura, intercaladas com lama clara, associadas às variações sazonais de produtividade do reservatório. Na porção final da Fácies 2 e toda a Fácies 3, ocorrem as maiores concentrações dos elementos traço (principalmente Cu, e Cr), parâmetros geomagnéticos, PCBs, DDT e HPAs, bem como o primeiro e maior declínio das populações de tecamebas. Nessa fácies 3 os VGQS indicam a presença de sedimentos fortemente contaminados. Fácies 4 continua a apresentar sucessão de camadas escuras e claras, contudo, as concentrações dos elementos traço, parâmetros geomagnéticos, PCBs, DDT e HPAs diminuem sensivelmente e os valores de densidade e diversidade das tecamebas aumentam. Valores de Cu diminuem mas, continuam expressivos, indicando sedimentos contaminados. As oscilações da concentração de Cu podem estar relacionadas ao uso de algicidas à base de CuSO4, que são utilizados no RSG para controlar a floração de cianobactérias e macrófitas. Fácies 5, correspondente ao período mais recente da história do RSG, caracteriza-se pela presença de lama preta, contaminada por Cu, pobre em tecamebas e baixas concentrações de DDT e HPAs. As curvas de evolução dos fluxos de fósforo inorgânico, Mn e Zn apresentaram forte similaridade com as curvas de crescimento demográfico da cidade de Americana e com as variações do regime de chuvas local. Estes resultados sugerem que as variações do aporte de nutrientes no reservatório encontram relação direta com as mudanças no escoamento de água pluvial na bacia de drenagem do Atibaia e com os influxos industriais e domésticos no RSG / This works presents an environmental evolution of the Reservatório de Salto Grande (RSG), Americana, accomplished through the grain-size, geochemical (phosphorous, carbon, trace elements, organochlorines and polycyclic aromatic hydrocarbons), and biological (thecamoebians) analyses from sample of a sediment core. Based on the results it was possible to: 1) evaluate the sediments according to the Sediment Quality Guideline Values for metals and associated (SQGV), enrichment factors, and geoaccumulation index and 2) identify five sedimentary facies through the core. Facies 1 located at the base of the core is composed of muddy sediments with low concentrations of trace elements, organochlorines and PAHs, presence of small trees roots and absence of thecamoebians. This sedimentary sequence could be attributed to soil units and sediments deposited in the alluvial basin of the Atibaia river and represents the pre-reservoir succession. From 177 cm through the top of the core more 4 facies are identified, all correlated with the time span of 65 years since the inundation of the RSG. Facies 2 (transition between soil portion and the reservoir inundation) is characterized by the presence of a homogeneous mud and a thin parallel planar stratification and by the appearance of thecamoebians (Arcella gibbosa, A. megastoma, Difflugia corona, D. oblonga, D. gramen, Centropyxis discoide aculeata). In this facies no contaminants were registered according to SQGV standards. But a high concentration of PAHs was detected possibly indicative of vegetation burning. Facies 3 (Reservoir) is marked by a succession of dark mud interleaved by whitish mud likely associated to seasonal variation of primary productivity in the reservoir. At the top portion of facies 2 and the whole extension of facies 3 were found the highest concentration of trace elements (Cu, and Cr), geomagnetic parameters, PCBs, DDT and PAHs, and the first and major decline of thecamoebians populations. In this facies SQGV are indicative of highly contaminated sediments. Facies 4 continuously shows the same succession of mud and the concentrations of trace elements, geomagnetic parameters, PCBs, DDT and PAHs show a sensitive decrease, and the values of richness and abundance of thecamoebians show an increase. Although the values of Cu diminish, they still remain expressive, indicative of sediment contamination. The oscillations of Cu concentrations may be related to the use of algaecides composed of CuSO4 in order to control populations of cyanobacteria and macrophytes. Facies 5 corresponds to the last centimeters of the core and to recent periods of the history of RSG, characterized by the presence of a black mud contaminated with Cu poor in species of thecamoebians and low concentrations of PCBs, DDT and PAHs. The curves of inorganic phosphorous, Mn and Zn showed a similar pattern to the curves of demographic growth and rain fall in the city of Americana. These results suggest that the variations of nutrients income are related to the change in water flow regimes in the Atibaia river watershed and to industrial and domestic input in the RSG
|
115 |
Estudo multidisciplinar da evolução ambiental do Reservatório de Salto Grande, Americana, SP, a partir de análises multiproxies geoquímicos, de magnetismo ambiental e biológicos (Tecamebas) / Multidisciplinary study of the environmental evolution of the Salto Grande Reservoir, Americana, SP, from analysis of geochemical multiproxies, environmental magnetism and thecamoebiansMaria Laura Misailidis Lerena 03 October 2016 (has links)
A presente dissertação é um estudo da evolução ambiental do Reservatório de Salto Grande (RSG), Americana, SP, realizado a partir de análises granulométrica, geomagnética, geoquímica (especiação fósforo e carbono, elementos traço, compostos organoclorados e hidrocarbonetos aromáticos policíclicos) e biológica (tecamebas) de amostras de um testemunho sedimentar de 233 cm. Com base nos resultados obtidos, foi possível: 1) avaliar a toxicidade dos sedimentos, de acordo com os valores-guia de qualidade de sedimentos (VGQS) TEL e PEL, fator de enriquecimento (EF) e índice de geoacumulação (Igeo) e 2) identificar cinco fácies sedimentares, ao longo do testemunho. Fácies 1, situada na base do testemunho, é constituída por lama, com baixas concentrações de elementos traço, compostos organoclorados e HPAs, presença de material radicular e ausência de tecamebas. Essa sequência sedimentar pode ser atribuída às unidades de solos e sedimentos depositados na planície aluvial do Rio Atibaia e representa a fase Préreservatório. A partir de 177 cm de profundidade rumo ao topo, passam ocorrer mais quatro fácies, indicativas dos 65 anos de existência do RSG. A Fácies 2 (transição de solo e início do reservatório) caracteriza-se pela presença de lama, com tênue estratificação plana paralela e surgimento de tecamebas (Arcella gibbosa, A. megastoma, Difflugia corona, D. oblonga, D. gramen e Centropyxis discoide aculeata). Nessa fácies não foram detectados sedimentos contaminados, segundo VGQS. Contudo, foi constatado aumento expressivo de HPAs, provavelmente relacionado a queimadas ocorridas no entorno do reservatório. Fácies 3 (Reservatório) é marcada por sucessão de camadas de lama escura, intercaladas com lama clara, associadas às variações sazonais de produtividade do reservatório. Na porção final da Fácies 2 e toda a Fácies 3, ocorrem as maiores concentrações dos elementos traço (principalmente Cu, e Cr), parâmetros geomagnéticos, PCBs, DDT e HPAs, bem como o primeiro e maior declínio das populações de tecamebas. Nessa fácies 3 os VGQS indicam a presença de sedimentos fortemente contaminados. Fácies 4 continua a apresentar sucessão de camadas escuras e claras, contudo, as concentrações dos elementos traço, parâmetros geomagnéticos, PCBs, DDT e HPAs diminuem sensivelmente e os valores de densidade e diversidade das tecamebas aumentam. Valores de Cu diminuem mas, continuam expressivos, indicando sedimentos contaminados. As oscilações da concentração de Cu podem estar relacionadas ao uso de algicidas à base de CuSO4, que são utilizados no RSG para controlar a floração de cianobactérias e macrófitas. Fácies 5, correspondente ao período mais recente da história do RSG, caracteriza-se pela presença de lama preta, contaminada por Cu, pobre em tecamebas e baixas concentrações de DDT e HPAs. As curvas de evolução dos fluxos de fósforo inorgânico, Mn e Zn apresentaram forte similaridade com as curvas de crescimento demográfico da cidade de Americana e com as variações do regime de chuvas local. Estes resultados sugerem que as variações do aporte de nutrientes no reservatório encontram relação direta com as mudanças no escoamento de água pluvial na bacia de drenagem do Atibaia e com os influxos industriais e domésticos no RSG / This works presents an environmental evolution of the Reservatório de Salto Grande (RSG), Americana, accomplished through the grain-size, geochemical (phosphorous, carbon, trace elements, organochlorines and polycyclic aromatic hydrocarbons), and biological (thecamoebians) analyses from sample of a sediment core. Based on the results it was possible to: 1) evaluate the sediments according to the Sediment Quality Guideline Values for metals and associated (SQGV), enrichment factors, and geoaccumulation index and 2) identify five sedimentary facies through the core. Facies 1 located at the base of the core is composed of muddy sediments with low concentrations of trace elements, organochlorines and PAHs, presence of small trees roots and absence of thecamoebians. This sedimentary sequence could be attributed to soil units and sediments deposited in the alluvial basin of the Atibaia river and represents the pre-reservoir succession. From 177 cm through the top of the core more 4 facies are identified, all correlated with the time span of 65 years since the inundation of the RSG. Facies 2 (transition between soil portion and the reservoir inundation) is characterized by the presence of a homogeneous mud and a thin parallel planar stratification and by the appearance of thecamoebians (Arcella gibbosa, A. megastoma, Difflugia corona, D. oblonga, D. gramen, Centropyxis discoide aculeata). In this facies no contaminants were registered according to SQGV standards. But a high concentration of PAHs was detected possibly indicative of vegetation burning. Facies 3 (Reservoir) is marked by a succession of dark mud interleaved by whitish mud likely associated to seasonal variation of primary productivity in the reservoir. At the top portion of facies 2 and the whole extension of facies 3 were found the highest concentration of trace elements (Cu, and Cr), geomagnetic parameters, PCBs, DDT and PAHs, and the first and major decline of thecamoebians populations. In this facies SQGV are indicative of highly contaminated sediments. Facies 4 continuously shows the same succession of mud and the concentrations of trace elements, geomagnetic parameters, PCBs, DDT and PAHs show a sensitive decrease, and the values of richness and abundance of thecamoebians show an increase. Although the values of Cu diminish, they still remain expressive, indicative of sediment contamination. The oscillations of Cu concentrations may be related to the use of algaecides composed of CuSO4 in order to control populations of cyanobacteria and macrophytes. Facies 5 corresponds to the last centimeters of the core and to recent periods of the history of RSG, characterized by the presence of a black mud contaminated with Cu poor in species of thecamoebians and low concentrations of PCBs, DDT and PAHs. The curves of inorganic phosphorous, Mn and Zn showed a similar pattern to the curves of demographic growth and rain fall in the city of Americana. These results suggest that the variations of nutrients income are related to the change in water flow regimes in the Atibaia river watershed and to industrial and domestic input in the RSG
|
116 |
Immune responses of juvenile chinook salmon (Oncorhynchus tshawytscha) to p,p-��DDE and tributyltinMisumi, Ichiro 24 July 2003 (has links)
In this thesis, we examined the effects of the exposures to anthropogenic
pollutants on the fish, primarily juvenile chinook salmon, immune system using newly
and recently developed immune assays. In addition, we developed a new assay for
measuring immunocompetence of fish. In the first chapter, the Alamar Blue assay was
developed to quantify the proliferation of chinook salmon (Oncorhynchus tshawytscha)
leukocytes. Isolated splenic and pronephric leukocytes were stimulated with different
concentration of mitogens (LPS, PWM, and ConA) for various incubation times.
Optimum cell culture conditions (cell density, mitogen concentration, and incubation
time) for the Alamar Blue assay were evaluated by comparison with flow cytometric
analysis. The Alamar Blue dye was non-toxic for leukocytes, and the assay proved to be
able to quantify the mitogenic responses using LPS, but PWM and ConA.
In the second chapter, we determined the effects and mechanisms by which p,p'-
DDE exposure might affect the immune system of chinook salmon (Oncorhynchus
tshawytscha). Isolated salmon splenic and pronephric leucocytes were incubated with
different concentrations of p,p'-DDE, and cell viability, induction of apoptosis, and
mitogenic responses were measured by flow cytometry and Alamar Blue assay. p,p'-
DDE significantly reduced cell viability and proliferation and increased apoptosis. The
effect of p,p'-DDE on pronephric leukocytes was more severe than on splenic leukocytes,
likely because pronephric leucocytes had a higher proportion of granulocytes, cells that
appear more sensitive to p,p'-DDE. The effect of p,p'-DDE on leucocytes appeared to
vary between developmental stages or season. The mitogenic response of leukocytes of
chinook salmon exposed to p,p'-DDE in vivo exhibited a biphasic dose-response
relationship. Only leukocytes isolated from salmon treated with 59 ppm p,p'-DDE had a
significantly lower percentage of Ig+ blasting cells than controls. Our results support the
theory that exposure to chemical contaminants could lead to an increase in disease
susceptibility and mortality of fish due to immune suppression.
In the third chapter, we evaluated the direct effects of in vitro exposures to
tributyltin (TBT), widely used biocide, on the cell mediated immune system of chinook
salmon (Oncorhynchus tshawytscha). Splenic and pronephric leukocytes isolated from
juvenile chinook salmon were exposed for 6, 24, or 96 hr to a concentration range of 0.03
0.1 mg TBT 1����� in cell cultures. Effects of TBT on cell viability, induction of apoptosis,
and mitogenic responses were measured by flow cytometry. Splenic and pronephric
leukocytes in the presence of TBT experienced a concentration-dependent decrease in the
viability in cell cultures following the induction of apoptosis. In addition, pronephric
lymphocytes exhibited a greater sensitivity to TBT exposure than pronephric
granulocytes. The functional ability of splenic B-cells to undergo blastogenesis upon
LPS stimulation was also significantly inhibited in the presence of 0.05, 0.07, or 0.10 mg
1����� of TBT in the cell cultures. Flow cytometric assay with the fluorescent conjugated
monoclonal antibody against salmon surface immunoglobulin was employed for the
conclusive identification of B-cell in the chinook salmon leukocytes. Our findings
suggest that adverse effects of TBT on the function or development of fish immune
systems could lead to an increase in disease susceptibility and its subsequent ecological
implications. / Graduation date: 2004
|
117 |
The protective effects of Ganoderma extracts from the endocrine disruption of p,p'-DDE on breast cancer cell model.January 2009 (has links)
Qin, Jing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 162-218). / Abstract also in Chinese. / Acknowledgment --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Table of Content --- p.vi / List of Figures --- p.x / List of Tables --- p.xv / Abbreviations --- p.xvii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Ganoderma spp --- p.1 / Chapter 1.1.1 --- Introduction of Ganoderma spp --- p.1 / Chapter 1.1.2 --- Bioactivities of Ganoderma spp --- p.3 / Chapter 1.1.3 --- Endocrine system and breast cancer --- p.11 / Chapter 1.1.3.1 --- Estrogen --- p.11 / Chapter 1.1.3.2 --- Estrogen receptors --- p.12 / Chapter 1.1.3.3 --- Estrogen responsive genes --- p.15 / Chapter 1.1.3.3.1 --- pS2 --- p.15 / Chapter 1.1.3.3.2 --- Progesterone receptor --- p.18 / Chapter 1.1.3.4 --- Androgen --- p.21 / Chapter 1.1.3.5 --- Androgen receptor --- p.23 / Chapter 1.1.3.6 --- Androgen responsive gene --- p.24 / Chapter 1.1.3.6.1 --- Transmembrane prostate androgen-induced RNA --- p.24 / Chapter 1.1.3.6.2 --- Uridine diphosphate glucose dehydrogenase --- p.26 / Chapter 1.1.3.7 --- Breast cancer --- p.26 / Chapter 1.2 --- "Endocrine Disruption of p,p '-DDE" --- p.28 / Chapter 1.2.1 --- Introduction of p´ةp '-DDE --- p.28 / Chapter 1.2.2 --- "p,p '-DDE in environments" --- p.29 / Chapter 1.2.3 --- "p,p '-DDE in human body" --- p.32 / Chapter 1.2.4 --- "p,p '-DDE and reproductive system" --- p.33 / Chapter 1.2.5 --- Endocrine disruptor --- p.35 / Chapter 1.2.6 --- "Action mechanism of p,p '-DDE on endocrine system" --- p.37 / Chapter 1.2.7 --- Apoptosis --- p.39 / Chapter 1.3 --- Food therapy against endocrine disruption --- p.41 / Chapter 1.3.1 --- Food therapy and functional food --- p.41 / Chapter 1.3.2 --- Ganoderma as a Functional food --- p.47 / Chapter 1.3.3 --- Cancer prevention by dietary agents --- p.47 / Chapter 1.3.4 --- Hormone therapy --- p.48 / Chapter 1.3.5 --- Hormone-related properties of Ganoderma spp --- p.50 / Chapter 1.4 --- The aim of the study --- p.51 / Chapter Chapter 2 --- Materials and Methods --- p.52 / Chapter 2.1 --- Ganoderma samples --- p.52 / Chapter 2.2 --- Artificial cultivation of Ganoderma spp --- p.54 / Chapter 2.3 --- Molecular identification of Ganoderma spp --- p.55 / Chapter 2.3.1 --- Extraction of genomic DNA --- p.55 / Chapter 2.3.2 --- Gene-specific polymerase chain reaction (PCR) --- p.56 / Chapter 2.3.3 --- Gel electrophoresis --- p.56 / Chapter 2.3.4 --- Purification of PCR amplified product for sequencing --- p.57 / Chapter 2.3.5 --- Cycle-sequencing --- p.57 / Chapter 2.3.6 --- Sequencing --- p.58 / Chapter 2.3.7 --- Sequence analysis --- p.58 / Chapter 2.4 --- Chemical analyses of Ganoderma spp --- p.59 / Chapter 2.4.1 --- Polysaccharide preparations --- p.59 / Chapter 2.4.2 --- Terpene profile --- p.60 / Chapter 2.4.3 --- Fatty acid profile --- p.60 / Chapter 2.5 --- Anti-oxidation activities --- p.61 / Chapter 2.5.1 --- Superoxide radical scavenging assay --- p.61 / Chapter 2.5.2 --- DPPH radical scavenging assay --- p.62 / Chapter 2.6 --- Anti-proliferation effect on human breast cancer cells --- p.62 / Chapter 2.7 --- Hormone-like effects --- p.63 / Chapter 2.7.1 --- E-screen test --- p.63 / Chapter 2.7.2 --- In vitro estrogen receptors (ERs) competitor binding assays --- p.64 / Chapter 2.7.3 --- "Recombinant yeast cell based ER-, AR- and PGR-responsible promoter assays" --- p.65 / Chapter 2.7.3.1 --- Recombinant yeasts --- p.65 / Chapter 2.7.3.2 --- Growth medium for recombinant yeasts --- p.66 / Chapter 2.7.3.3 --- "ER, AR and PGR assays" --- p.67 / Chapter 2.7.3.4 --- β-Galactosidase assay --- p.67 / Chapter 2.7.4 --- Real time PCR --- p.68 / Chapter 2.8 --- Flow cytometry --- p.71 / Chapter 2.9 --- Comet assay --- p.71 / Chapter 2.10 --- DNA microarray --- p.73 / Chapter 2.10.1 --- Total RNA isolation --- p.73 / Chapter 2.10.2 --- cDNA synthesis --- p.73 / Chapter 2.10.3 --- Preparation of labelled cDNA --- p.74 / Chapter 2.10.4 --- cDNA purification --- p.74 / Chapter 2.10.5 --- Oligo GEArray hybridization --- p.75 / Chapter 2.10.6 --- Chemiluminescent detection --- p.76 / Chapter 2.10.7 --- Data analysis --- p.77 / Chapter Chapter 3 --- Results --- p.78 / Chapter 3.1 --- Analysis of Ganderma spp --- p.78 / Chapter 3.1.1 --- Mycelia and fruiting bodies --- p.78 / Chapter 3.1.2 --- Identification of Ganoderma spp --- p.79 / Chapter 3.1.3 --- Chemical properties of samples --- p.80 / Chapter 3.1.4 --- Anti-oxidation activities --- p.90 / Chapter 3.1.5 --- Anti-proliferation effect on human breast cancer cells --- p.90 / Chapter 3.1.6 --- Hormone-like bioactivities --- p.93 / Chapter 3.1.6.1 --- E-screen test --- p.93 / Chapter 3.1.6.2 --- In vitro estrogen receptors (ERs) competitor binding assays --- p.94 / Chapter 3.1.6.3 --- "Recombinant yeast cell-based ER-, AR- and PGR-responsible promoter assays" --- p.95 / Chapter 3.1.6.4 --- ER- and AR-pathway gene expression by real time PCR --- p.97 / Chapter 3.2 --- "Action mechanism of p,p' -DDE" --- p.99 / Chapter 3.2.1 --- E-screen --- p.99 / Chapter 3.2.2 --- In vitro estrogen receptors (ERs) competitor binding assays --- p.101 / Chapter 3.2.3 --- Recombinant yeast cell based ER- and AR-responsible promoter assays --- p.103 / Chapter 3.2.4 --- ER- and AR-pathway gene expression by real time PCR --- p.106 / Chapter 3.3 --- Ganoderma tsugae mycelia extract against p.p' -DDE --- p.109 / Chapter 3.3.1 --- E-screen test --- p.109 / Chapter 3.3.2 --- ER- and AR-pathway gene expression by real time PCR --- p.110 / Chapter 3.3.3 --- Analysis of cell cycle --- p.112 / Chapter 3.3.4 --- Analysis of DNA damage --- p.114 / Chapter 3.3.5 --- Analysis of sub-G1 peak --- p.117 / Chapter 3.3.6 --- DNA damage and apoptosis relative gene expression by real time PCR --- p.120 / Chapter 3.3.7 --- DNA microarray --- p.121 / Chapter Chapter 4 --- Discussion --- p.131 / Chapter 4.1 --- Analysis of Ganoderma spp --- p.131 / Chapter 4.2 --- Effects of p.p´ة-DDE --- p.144 / Chapter 4.3 --- Protective effects of G. tsugae against p.p' -DDE --- p.151 / Chapter 4.4 --- Further investigation --- p.159 / Chapter 4.5 --- Conclusion --- p.160 / References --- p.162
|
118 |
The history of environment, science and society told by DDT = a discourse and content analysis of the media from the United States and Brazil between 1944 and 2014 = A história do ambiente, ciência e sociedade contada pelo DDT: uma análise de discurso e de conteúdo da mídia dos Estados Unidos e do Brasil entre 1944 e 2014 / A história do ambiente, ciência e sociedade contada pelo DDT : uma análise de discurso e de conteúdo da mídia dos Estados Unidos e do Brasil entre 1944 e 2014Gaissler, Rubia Pereira, 1986- 27 August 2018 (has links)
Orientadores: Aline Vieira de Carvalho, Jansle Vieira Rocha / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-27T17:44:32Z (GMT). No. of bitstreams: 1
Gaissler_RubiaPereira_D.pdf: 5274430 bytes, checksum: d24c8d8f3ef14a2501b1e01a9e473735 (MD5)
Previous issue date: 2015 / Resumo: Esta tese de doutorado teve como objetivo analisar a cobertura midiática do pesticida DDT desde a sua primeira aparição na mídia, em 1944, até 2014. O objetivo estabelecido foi de identificar as principais narrativas usadas para falar sobre o DDT e as mudanças observadas no discurso referente ao mesmo durante todo o período de tempo acima mencionado. Isto foi atingido observando uma porção selecionada da mídia de dois países que têm um histórico relevante no que diz respeito ao DDT: os Estados Unidos e o Brasil. O primeiro foi escolhido por se tratar de um usuário intenso e um forte defensor da utilização do DDT entre as décadas de 1940 e 1960, e também por ter sido o vórtice de um debate que levou à proibição global do DDT, na década de 1970; o segundo foi incluído na análise para oferecer um contraponto ao primeiro, justificado por uma diferença muito distinta em aspectos culturais, geográficos, econômicos e demográficos. Foram analisadas as revistas Estadunidenses TIME, The New Yorker e Popular Science, e as revistas brasileiras Veja e Superinteressante. O estudo identificou uma virada discursiva única na cobertura da mídia, em 1967, quando DDT deixou de ser visto majoritariamente como benéfico e passou a ser principalmente visto como prejudicial. A análise quantitativa das 711 unidades midiáticas que fizeram parte do conjunto de dados mostrou oscilações na intensidade da cobertura ao longo dos 70 anos estudados, com destaque para um pico entre 1969 e 1971, sendo que tais variações foram interpretadas trazendo o contexto histórico-cultural de cada período abordado e considerando a trajetória do movimento ambientalista, do jornalismo científico e da própria ciência. Adicionalmente, a tese foi estruturada objetivando desmistificar o papel da bióloga norte-americana Rachel Carson na proibição de DDT, investigando sua influência na trajetória do discurso relacionado ao DDT tanto na época em que lançou a obra Primavera Silenciosa, em 1962, quanto observando de que maneiras o retrato da sua figura enquanto símbolo evoluiu nas décadas seguintes até chegar às representações oferecidas no presente / Abstract: This doctoral thesis aimed to analyze the media coverage of the pesticide DDT since its first appearance in the media, in 1944, until 2014. The established objective was to identify the main narratives used to talk about DDT and the observed discourse changes related to it throughout the period of time aforementioned. This was achieved by looking into selected media from two countries that have a relevant history concerning DDT: The United States and Brazil. The first was chosen because it was a heavy user and a strong advocate for DDT use from the 1940s to the 1960s, and also because it was the vortex of a debate that led to the DDT world ban in the 1970s; the second was included in the analysis to offer a counterpoint to the first, justified by a very distinct difference in cultural, geographic, economic and demographic aspects. The United States¿ magazines TIME, The New Yorker, and Popular Science were analyzed, and also the Brazilian magazines Veja and Superinteressante. The research identified a single discourse flip in the media coverage, in 1967, when DDT stopped being majorly seen as beneficial and started being predominantly faced as harmful. The quantitative analysis of the 711 media units that composed the data set showed oscillations in the coverage intensity during the 70 years studied, with a highlight to a peak between 1969 and 1971; such variations were interpreted bringing the historical and cultural context of each period and considering the trajectory of the environmental movement, the scientific journalism and of science itself. Additionally, the thesis was structured aiming to demystify the role of the North American biologist Rachel Carson in the DDT ban, investigating her influence in the DDT discourse trajectory not only when the Silent Spring was published, in 1962, but also observing in which ways her portraying as a symbol evolved in the following decades until reaching today¿s representations / Doutorado / Aspectos Biológicos de Sustentabilidade e Conservação / Doutora em Ambiente e Sociedade
|
119 |
DDE METABOLISM BY THE ISOLATED PERFUSED BOVINE LIVER.Arnold, Jean E. D. January 1983 (has links)
No description available.
|
120 |
The relationship between the insecticide dichloro-diphenyl-trichloroethane and chloroquine in Plasmodium falciparum resistanceMakowa, Hazel Beverly 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Dichloro-diphenyl-trichloroethane (DDT) was extensively used in agriculture pest control and
is still used for indoor residual spraying to control malaria. The lipophylicity of DDT and its
breakdown product dichloro-diphenyl-dichloroethylene (DDE) dictates that they associate
with membranes, lipids and hydrophobic proteins in the biological environment. Their poor
degradable nature causes DDT and DDE to persist for decades in the environment and in
individuals who are or were in contact with the pesticide. In many countries the synchronised
resistance of the mosquito vector to insecticides and the malaria parasite towards antimalarial
drugs led to a drastic rise in malaria cases and to malaria epidemics. This study assesses the
influence of low level exposure of DDT and DDE on chloroquine (CQ) resistance of the dire
human malaria parasite, Plasmodium falciparum.
The in vitro activity of p,p’-DDT and p,p’-DDE towards blood stages of chloroquine sensitive
(CQS) P. falciparum D10 and chloroquine resistant (CQR) P. falciparum Dd2 was
determined using two complementary in vitro assays (Malstat and SYBR Green 1). The 50%
inhibition concentrations (IC50s) of p,p’-DDT and p,p’-DDE were found to be ±14 to 38 μM
(5-12 μg/mL) and highly similar towards CQS and CQR P. falciparum strains. This result
indicated that the proteins involved in CQ resistance have no effect on the activity of the
insecticide DDT and it breakdown product DDE.
In order to assess the influence of DDT and DDE on CQ activity, in vitro fixed ratio drug
combination assays were performed, as well as isobologram analysis. We found that CQ
works in synergy with p,p’-DDT and p,p’-DDE against CQS P. falciparum D10. However,
both p,p’-DDT and p,p’-DDE were antagonistic toward CQ activity in CQR P. falciparum
Dd2. This indicated that p,p’-DDT and p,p’-DDE do have an effect on CQ resistance or on
the action of CQ via a target other than hemozoin polymerization. The observation of
reciprocal synergism of p,p’-DDT and p,p’-DDE with CQ against CQS D10 and antagonism
against CQR Dd2 strain is highly significant and strongly indicates selection of CQ resistant
strains in the presence of p,p’-DDT and p,p’-DDE. People who have low levels of circulating
DDE and/or DDT could be at a high risk of contracting CQR malaria. However, medium term
(nine days) DDE exposure of CQS P. falciparum D10 did not induce resistance, as no
significant change in activity of CQ, p,p’-DDT and p,p’-DDE towards blood stages the CQS
strain was observed. This exposure was, however, shorter than expected for a malaria
infection and would be addressed in future studies.
From our results on the interaction of CQ with p,p’-DDT and p,p’-DDE, it was important to
assess the residual DDT and DDE variable and how much of residual p,p’-DDT and/or p,p’-
DDE would enter into or remain in the different compartments (the RPMI media, erythrocytes
and infected erythrocytes) over time. In combination with liquid-liquid extraction, we
developed a sensitive GC-MS analyses method and a novel HPLC-UV analysis method for
measuring DDT and DDE levels in malaria culturing blood and media. Whilst the HPLC-UV
method was relatively cheaper, faster, and effective in determining high DDT and DDE
concentrations, the optimised GC-MS method proved to be effective in detecting levels as
low as 78 pg/mL (ppt) DDE and 7.8 ng/mL (ppb) DDT in biological media. Using both the
HPLC and GC-MS methods we observed that malaria parasites influence distribution of the
compounds between the erythrocytic and media fractions. P. falciparum D10 infection at
±10% parasitemia lead to must faster equilibration (less than 8 hours) between compartments.
Equimolar distribution of p,p’-DDE was observed, but the parasites lead to trapping of the
largest fraction of p,p’-DDT in the erythrocyte compartment. These results indicate that a
substantial amount would reach the intra-erythrocytic parasite and could influence the
parasite directly, possibly leading to either synergistic or antagonistic drug interactions.
This study is the first to illustrate the “good and bad” of the insecticide DDT in terms of CQ
resistance and sensitivity toward the human malaria parasite P. falciparum. These results will
hopefully have an important influence on how future policies on malaria control and
treatment particularly in endemic areas will be addressed and could also have an impact on
the anti-malarial drug discovery approach. / AFRIKAANSE OPSOMMING: Dichlorodifenieltrichloroetaan (DDT) is op groot skaal in landbouplaagbeheer gebruik en
word nog steeds gebruik vir binnenshuise oppervlakbespuiting om malaria te beheer. Die
lipofilisiteit van DDT en sy afbraakproduk dichlorodifenieldichloroetileen (DDE) dikteer dat
hulle met membrane, lipiede en hidrofobiese proteïene in die biologiese omgewing
assosieer. Stadige afbraak veroorsaak dat DDT en DDE vir dekades in die omgewing
agterbly, asook in individue wat in kontak is, of was met die insekdoder. In baie lande het
gesinkroniseerde weerstand van die muskietvektor teenoor insekdoders en die malariaparasiet
teenoor antimalariamiddels gelei tot 'n drastiese styging in malariagevalle en tot malariaepidemies.
In hierdie studie word die invloed van lae vlak blootstelling van DDT en DDE op
chlorokien (CQ) weerstand van die mens malariaparasiet, Plasmodium falciparum,
geëvalueer.
Die in vitro aktiwiteit van p,p'-DDT en p,p'-DDE teenoor die bloedstadia van chlorokiensensitiewe
(CQS) P. falciparum D10 en chlorokien-weerstandbiedende (CQW) P. falciparum
Dd2 is bepaal deur gebruik te maak van twee komplementêre in vitro toetse (Malstat en
SYBR Groen toetse). Die 50% inhibisie konsentrasies (IC50s) van p,p'-DDT en p,p'-DDE is
bepaal as ±14 to 38 μM (5-12 μg/mL) en was hoogs vergelykbaar tussen CQS en CQW P.
falciparum stamme. Hierdie resultaat het aangedui dat die proteïene betrokke by CQ
weerstand geen effek op die aktiwiteit van die insekdoder DDT en die afbraakproduk DDE
het nie.
Om die invloed van DDT en DDE op CQ aktiwiteit te evalueer, is die aktiwiteit van
kombinasies van die verbindings in vaste verhoudings getoets, tesame met isobologram
ontleding. Ons het gevind dat CQ sinergisties saam met p, p'-DDT en p, p'-DDE teen CQS P.
falciparum D10 werk. Daarteenoor het beide p, p'-DDT en p, p'-DDE antagonistiese werking
getoon teenoor CQ aktiwiteit met CQW P. falciparum Dd2 as teiken. Dit het aangedui dat
p,p'-DDT en p, p'-DDE wel 'n invloed op CQ weerstand het of ‘n aktiwiteit van CQ, anders as
hemozoin polimerisasie, beïnvloed. Die waarneming van resiproke sinergisme en
antagonisme van p, p'-DDT en p, p'-DDE in kombinasie met CQ teenoor die CQS D10 en
CQW DD2 stamme respektiewelik, is hoogs betekenisvol en dui op seleksie van CQweerstandige
stamme in die teenwoordigheid van p, p'- DDT en p, p'-DDE. Mense wat lae
vlakke van sirkulerende DDE/DDT het, het dus 'n hoër risiko om CQW malaria te kry.
Verder is gevind dat medium termyn (nege dae) DDE blootstelling van CQS P. falciparum
D10 nie weerstand nie veroorsaak nie, want geen beduidende verandering in die aktiwiteit
van CQ, p,p'-DDT en p,p'-DDE teenoor die bloed stadiums van die CQS stam is waargeneem
nie. Hierdie blootstelling is egter korter as in 'n malaria-infeksie en sal verder bestudeer word
in toekomstige studies.
Vanuit die interaksie resultate van CQ met p, p'-DDT en p, p'-DDE was dit belangrik om die
residuele DDT en DDE veranderlike te evalueer, asook die distribusie van p,p'-DDT en p,p'-
DDE tussen die verskillende kompartemente (die kultuurmedium, eritrosiete en geïnfekteerde
rooibloedselle) oor verloop van tyd. In kombinasie met vloeistof-vloeistof ekstraksie, het ons
'n sensitiewe GC-MS en nuwe HPLC-UV analisemetode ontwikkel vir die meet van DDT en
DDE-vlakke in bloed (normale en geïnfekteerde eritrosiete) en die kultuurmedium. Terwyl
die HPLC-UV metode relatief goedkoper, vinniger en effektief in die bepaling van hoë DDT
en DDE-konsentrasies is, was die geoptimaliseerde GC-MS metode doeltreffend in die
opsporing van vlakke so laag as 78 pg/mL (dpt) DDE en 7.8 ng/mL (dpb) DDT in biologiese
media. Met behulp van beide die HPLC-UV en GC-MS metodes is waargeneem dat die
malariaparasiet die ekwilibrasie van die verbindings tussen die eritrosiet- en media
kompartemente beïnvloed. P. falciparum D10 infeksie met ± 10% parasitemia lei tot vinniger
ekwilibrasie (minder as 8 uur) tussen die kompartemente. Ekwimolêre verspreiding van p,p'-
DDE is waargeneem, maar die parasiete het die grooste fraksie van p,p'-DDT in die eritrosiet
kompartement vasgevang. Hierdie resultate wys dat 'n aansienlike fraksie die intraeritrositiese
parasiet kan bereik en sodoende die parasiet direk kan beïnvloed en moontlik kan
lei tot sinergistiese of antagonistiese middel interaksies.
Hierdie studie is die eerste om die "goed en sleg" van die insekdoder DDT in terme van CQ
weerstand en sensitiwiteit teenoor die menslike malariaparasiet P. falciparum te
illustreer. Hierdie resultate sal hopelik 'n belangrike invloed hê op die toekomstige beleid oor
die beheer van malaria en behandeling, veral in endemiese gebiede, en mag ook 'n impak hê
op die antimalariamiddel navorsing.
|
Page generated in 0.0464 seconds