21 |
Determinação simultânea de etinilestradiol e drospirenona em contraceptivos orais por cromatografia e fase líquida de alta eficiência e eletroforese capilar / Simultaneous determination of ethinyl estradiol and drospirenone in oral contraceptive by high performance liquid chromatography and cappilary electrophoresisViviane Benevenuti Silva 13 November 2012 (has links)
O controle da fertilidade é obtido principalmente pela inibição da ovulação por meio da atividade combinada de dois componentes principais: estrogênio e progestina. Desta forma, novas formulações vêm sendo desenvolvidas com baixa dose de etinilestradiol associado a um novo agente progestógeno, a drospirenona, com o objetivo de garantir equilíbrio entre eficácia, segurança e controle de ciclo menstrual. Este trabalho tem como objetivo desenvolver, validar e comparar métodos analíticos para a identificação e quantificação de etinilestardiol e drospirenona presentes em uma mesma formulação por cromatografia em fase líquida de alta eficiência (CLAE) e a eletroforese capilar (EC). O método por CLAE, foi realizado empregando-se uma coluna LiChoCART® 100RP - C18, (125 x 4 mm) 5 µm, fase móvel constituída por MeCN/H2O 50:50 (v/v) e vazão de 1.0 mL min. Utilizou-se um detector UV 200 nm para drospirenona e um de fluorescência λex = 280 nm e λem = 310 nm, para o etinilestradiol. O método por EC foi validado utilizando-se como eletrólito, tampão de tetraborato de sódio 30 mM, dodecil sulfato de sódio 20 mM e acetonitrila 30% a pH 9,2, capilar de sílica fundida de 31,2 cm sendo 21 cm efetivos, com 75 µm de diâmetro interno. O método por CLAE apresentou um coeficiente de correlação (r2) de 0,9989 para o etinilestradiol e 0,999 para a drospirenona. No método por EC, o coeficiente de correlação (r2) encontrado foi de 0,9988 para o etinilestradiol e 0,998 para a drospirenona. Os métodos podem ser considerados eficientes e confiáveis para serem empregados em análise de rotina para controle de qualidade destes produtos farmacêuticos. / The fertility control is achieved mainly by inhibiting ovulation through the combined activity of two main components: estrogen and progestin. Thus, new formulations have been developed associating appropriately low dose of ethinylestradiol to a new drug, the drospirenone, in order to ensure the balance between efficacy, safety and cycle control. The objective of this research was to develop, to validate and to compare two analytical method for separation and quantification of ethinylestardiol and drospirenone using high performance liquid chromatography and capillary electrophoresis (CE). The HPLC method, was performed using a LiChoCART® 100RP - C18, (125 x 4 mm) 5 µm column, a mobile phase constituted of acetonitrile:water (50:50 v/v) and flow rate of 1.0 mL min. UV detection was made for drospirenone at 200 nm coupled with a fluorescence detector at λex= 280 nm and λem = 310 nm for ethinylestradiol. The CE method was validated using a solution of sodium tetraborate buffer 30 mM, sodium dodecil sulphate 20 mM and acetonitrile 30%, pH 9.2 and a fused silica capillary of 31,2 cm with 21 cm effective and 75 µm of diameter. The HPLC method showed a correlation coefficient (r2) of 0.9989 for ethinylestradiol and 0,999 for drospirenone. For CE method, the correlation coefficient was (r2) 0,9988 for ethinylestradiol and 0,9989 for drospirenone. The methods showed to be efficient and reliable, and can be used in routine analysis for quality control of these pharmaceutical preparations.
|
22 |
Avaliação da atividade estrogênica das águas do Rio Paraíba do Sul / Evaluation of estrogenic activity in water samples from Paraiba do Sul RiverGuilherme Casoni da Rocha 14 December 2012 (has links)
A poluição da água doce no estado de São Paulo ocorre por diversas causas. Entre elas está a ineficiência do serviço de tratamento de esgoto sanitário. Alguns componentes do esgoto sanitário são desreguladores endócrinos, entre eles estão os hormônios naturais e sintéticos excretados pelos seres humanos. Estas substâncias causam modificações no sistema reprodutivo como, por exemplo, câncer, feminização, alterações na transcrição genética, alteração nas gônadas, indução à síntese de vitelogenina, entre outros. O objetivo desse trabalho foi testar a atividade endócrina das águas do rio Paraíba do Sul, em Pindamonhangaba, SP. Para tanto, amostras de água do rio foram utilizadas para a quantificação dos hormônios, 17-etinilestradiol, 17-estradiol e levonorgestrel por meio da técnica de cromatografia líquida de alta eficiência (HPLC). Além disso, foram realizados testes crônicos com peixes (Danio rerio) no interior do rio e em laboratório, e uma posterior quantificação de vitelogenina. Os resultados não indicaram concentrações detectáveis dos hormônios pelo método empregado. Entretanto, foi detectada a indução de vitelogenina nos machos de Danio rerio. Esse fato indica a atividade estrogênica da água utilizada. São necessários outros estudos para a avaliação de quais substâncias presentes na água, estão causando as alterações endócrinas nos peixes, entre eles a utilização de índices para priorizar o local inicial dessas pesquisas. Esses estudos são importantes para a conservação da biodiversidade aquática do rio Paraíba do Sul / Freshwater pollution in São Paulo state, Brazil, occurs due a several reasons. Among them there is the inefficiency of the sewage treatment service. Some sewage components are endocrine disrupters, including natural and synthetic hormones excreted by humans. These substances cause modification on reproductive system such as cancer, feminization, gene transcription and gonad alterations, vitellogenin synthesis induction, among others. The aim of this work was to evaluate the endocrine activity of the river Paraíba do Sul, at Pindamonhangaba city, Brazil. For this, river water samples were collected for the quantification of the hormones, 17- etinylestradiol, 17-estradiol and levonorgestrel by high performance liquid chromatography (HPLC). Furthermore, chronic assays were performed with fish (Danio rerio) into the river and in the laboratory, following quantification of biomarker vitellogenin. The studied hormones were not detected by employed methods. However, induction of vitellogenin in male of Danio rerio was detected indicating estrogenic activity of water. Further studies are necessary for the assessment of which substances into the water are causing the endocrine disruption in fish. These studies are important for the preservation of aquatic biodiversity of the Paraiba do Sul River
|
23 |
Degradação de hormônio sintético por meio de lacases fúngicas imobilizadas em fibras de Luffa cylindrica / Degradation of synthetic hormone by fungal laccases immobilized on Luffa cylindrica fibersLacerda, Monike Fabiane Alves Ribeiro 24 September 2015 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2016-01-29T13:40:00Z
No. of bitstreams: 2
Dissertação - Monike Fabiane Alves Ribeiro Lacerda - 2015.pdf: 2186149 bytes, checksum: 3cc547d5ad7e335bd22528c5658d79f5 (MD5)
license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2016-01-29T13:41:34Z (GMT) No. of bitstreams: 2
Dissertação - Monike Fabiane Alves Ribeiro Lacerda - 2015.pdf: 2186149 bytes, checksum: 3cc547d5ad7e335bd22528c5658d79f5 (MD5)
license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-29T13:41:34Z (GMT). No. of bitstreams: 2
Dissertação - Monike Fabiane Alves Ribeiro Lacerda - 2015.pdf: 2186149 bytes, checksum: 3cc547d5ad7e335bd22528c5658d79f5 (MD5)
license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5)
Previous issue date: 2015-09-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The 17α-ethinylestradiol (EE2) is a synthetic estrogen used in contraceptive and hormone
replacement therapies; is an environmental contaminant potential, it is not completely
removed in sewage treatment plants, reaching the aquatic environment, with the aggravating
factor interfere the endocrine system of humans and other animals. For this reason there is
great interest in the removal of EE2 present in wastewater, surface water and groundwater.
Thus the use of laccase for this purpose may be promising because of low specificity of this
enzyme to the substrate. Therefore, the aim of this study was to evaluate the effectiveness of
laccase produced by the fungus Pleurotus ostreatus immobilized in Luffa cylindrica (loofah)
fibers in EE2 degradation. Therefore the best means for production of laccase and the best
conditions of pH and temperature were investigated. The immobilization process was realized
and removal of the EE2 assay was conducted in flasks and in a batch reactor. Thus, the best
means for producing laccase were Potato Dextrose and Potato Dextrose Modified with
guariroba straw. Readings taken with 2.2-Azino-bis (3-ethylbenzothializone-6-sulfonic acid) -
ABTS revealed best pH between 3.6 and 4.6 and optimal band temperature between 30 and 50
°C for free and immobilized enzymes. The laccase produced in both media had an apparent
molecular mass of 40 kDa. The best conditions found for the immobilization process were
glutaraldehyde concentration of 2% and reaction with the support 1 hour under stirring (120
rpm); drying the loofah prior to the reaction with glutaraldehyde; time of 24 hours of
immobilization. The immobilized enzyme showed best enzymatic activity in alkaline pH, and
at higher temperatures, compared to the free enzyme. The operational stability, storage and
thermostability were not significant. Best removals for tests in flasks were 79.22% and 75.0%
for free and immobilized enzyme, respectively. As the tests carried out in the reactor showed
removal by adsorption of 99.3% and 73.14% in the Luffa cylindrica, the immobilized enzyme.
However, it is necessary to optimize the immobilization process, as well as the test in the
reactor to increase the degradation EE2. / O 17α-etinilestradiol (EE2) é um estrogênio sintético utilizado na contracepção e em terapias
de reposição hormonal; é um potencial contaminante ambiental, pois não é completamente
removido nas estações de tratamento de esgotos, podendo alcançar o ambiente aquático, tendo
o agravante de interferir no sistema endócrino de seres humanos e de outros animais. Por esse
motivo existe um grande interesse na remoção do EE2 presente em águas residuárias,
superficiais e subterrâneas. Assim, o uso de lacase para esse fim pode ser promissor, devido à
baixa especificidade desta enzima ao substrato. Portanto, o objetivo desse trabalho foi avaliar
a eficácia da lacase produzida pelo fungo Pleurotus ostreatus imobilizada em fibras de Luffa
cylindrica (bucha vegetal) na degradação do EE2. Para tanto foram selecionados meios de
cultivo para produção da lacase, bem como as melhores condições de pH e temperatura. Após
a realização do processo de imobilização, a remoção do EE2 foi atingida em ensaios em
erlenmeyers e em um reator em batelada. Assim, os melhores meios para a produção de lacase
foram o Batata Dextrose e o Batata Dextrose Modificada com palha de guariroba. As leituras
realizadas com 2,2-Azino-bis (3-ethylbenzothializone-6-sulfonic acid) - ABTS revelaram
melhores pH entre 3,6 e 4,6 e faixas de temperaturas ótimas entre 30 e 50 ºC para as enzimas
livre e imobilizada. A lacase produzida em ambos os meios apresentou massa molecular de 40
kDA. As melhores condições encontradas para o processo de imobilização foram
concentração de glutaraldeído de 2% e reação com o suporte em 1 hora sob agitação (120
rpm); secagem da bucha vegetal antes da reação com glutaraldeído; tempo imobilização de 24
horas. A enzima imobilizada apresentou melhores atividades enzimáticas em pH alcalinos e
em temperaturas mais elevadas, comparadas com a enzima livre. A estabilidade operacional, a
de armazenamento e termoestabilidade não foram significativas. As melhores remoções do
EE2 para os ensaios nos erlenmeyers foram de 79,22% e 75,0% para as enzimas livre e
imobilizada, respectivamente. Enquanto os ensaios realizados no reator mostraram remoções
de 99,23% por adsorção na Luffa cylindrica e 73,14%, por degradação pela enzima
imobilizada. Contudo, se faz necessário otimizar o processo de imobilização, bem como o
ensaio no reator para que haja aumento da degradação do EE2.
|
24 |
Vliv vybraných endokrinních disruptorů na cytochromy P450 1B1 a 3A1/2 / The effect of selected endocrine disruptors on cytochromes P450 1B1 and 3A1/2Holecová, Jana January 2017 (has links)
Many exogenous and endogenous compounds are referred to as endocrine disruptors (EDCs), as they interfere with natural synthesis, signaling and metabolism of endogenous hormones. Common exogenous endocrine disruptors are benzo(a)pyrene (BaP) and 17α-ethinylestradiol (EE2). Endogenous endocrine disruptor 17β-estradiol (E2) is frequently present in the environment as well. In this thesis, the effect of the mentioned EDCs and their combinations on gene and protein expression of CYP1B1, 3A1 and 3A2 in rat liver, kidney and lung was determined. Protein expression was studied using Western blot method and specific antibodies; gene expression was assessed by quantitative PCR. Moreover, the effect of tested EDCs and their combinations on BaP metabolism and CYP3A specific activity (measured as testosterone 6β-hydroxylation) were studied in liver microsomal samples. It was confirmed, that BaP significantly increases CYP1B1 expression in rat liver and lung both alone and together with EE2 or E2. Pretreatment of rat with E2 and BaP increases the ability of BaP to induce CYP1B1 expression. On the contrary, EE2, E2 and their combination decrease the CYP1B1gene expression. The rate of BaP metabolites formed in liver microsomal samples increases in rats pretreated with BaP and its combinations. In liver, there was...
|
25 |
DEVELOPMENT OF A PAT MONITORED FLUID BED GRANULATION PROCESS USING THE EXAMPLE OF A LOW DOSE STEROID HORMONERossteuscher-Carl, Katrin 03 April 2019 (has links)
According to ICH Q8 process analytic technology (PAT) should be established to monitor critical quality attributes (CQAs) during manufacturing processes. Ethinylestradiol (EE) is a highly active and low dosed steroid hormone that is prone to oxidative degradation. The stability of this compound is therefore a critical quality attribute that has to be considered during drug formulation development. Beside the stability of EE, granule particle size and moisture are CQAs influencing the tableting ability of the resulting granules and the stability of EE. Both CQAs should be monitored during the production process.
The investigations described in this thesis evaluate the implementation of in-line-sensors for monitoring of particle size (spatial filtering technology, SFT) and granule moisture (microwave resonance technology, MRT) during the fluid bed granulation process and the influence of process-variations on the stability of EE. The aim of these investigations was to develop an effective and mild fluid bed granulation process for a new model formulation based on microcrystalline cellulose as replacement for lactose as main filler excipient. The EE degradation products 6-alpha-hydroxy-EE, 6-beta-hydroxy-EE, 9(11)-dehydro-EE and 6-oxo-EE were quantified as an index for the stability of EE.
It could be demonstrated that the surface of the filler substance influences the stability of EE due to the impact of water molecules. Hence, spraying sequence was determined to be a useful tool to improve the stability of EE. Correlations could be established for 6-oxo-EE with granule moisture and thermic parameters. The implementation of the SFT-sensor in the granulation process was successful. Measurement with the MRT-sensor for monitoring of granule moisture has to be improved.:Chapter I 1
1 Introduction
Chapter II 41
2 Materials and Methods
Chapter III 54
3 In-line Monitoring of Particle Size in a Fluid Bed Granulator: investigations concerning positioning and configuration of the sensor
Chapter IV 72
4 Influence of in line monitored fluid bed granulation process parameters on the stability of Ethinylestradiol
Chapter V 90
5 Influence of filler excipients on stability of EE
Chapter VI 105
6 Discussion and Conclusion
Chapter VII 131
7 Summary
Chapter VIII 138
8 Zusammenfassung
Reference List 146
Appendix 158
|
26 |
Heterogeneous photocatalytic degradation of organic pollutants in water over nanoscale powdered titanium dioxide. The photocatalytic degradation of organic compounds in water (Reactive Orange 16, Triclocarbon, Clopyralid and Estrogens (estrone, 17ß-estradiol, and 17α-ethinylestradiol)) was studied; the reaction kinetics and the effect of the operating parameters on the performance of the system were determined; a comparison with other advanced oxidation processes (O3, H2O2, UV) was also made.Mezughi, Khaled M. January 2010 (has links)
Organic contaminants from industrial and/or domestic effluents may be harmful to humans directly or indirectly by degrading the quality of the aquatic environment. Consequently these contaminants must be reduced to levels that are not harmful to humans and the environment before disposal. Chemical, physical and biological methods exist for the removal of these pollutants from effluents. Among the available chemical methods, heterogeneous photocatalytic oxidation has been found particularly effective in removing a large number of persistent organics in water. In this study, photocatalytic degradation was explored for the removal of reactive azo-dye (textile dye), triclocarban (disinfectant), clopyralid (herbicide) and three endocrine disrupting compounds (EDCs) (estrone, 17ß-estradiol and 17α-ethinylestradiol) from synthetic effluents. The major factors affecting the photocatalytic processes including the initial concentration of the target compounds, the amount of catalyst, the light intensity, the type of catalyst, the electron acceptor, the irradiation time and the pH were studied. Other oxidation techniques including (O3, H2O2, UV) were also studied.
Generally UV light is used in combination with titanium dioxide, as photocatalyst, to generate photoinduced charge separation leading to the creation of electron-hole pairs. The holes act as electron acceptors hence the oxidation of organics occur at these sites. These holes can also lead to the formation of hydroxyl radicals which are also effective oxidants capable of degrading the organics.
The results obtained in this study indicated that photolysis (i.e. UV only) was found to have no effect on the degradation of reactive azo-dye (RO16). However, complete photocatalytic degradation of 20 mg/L (3.24×10-2 mM) RO16 was achieved in 20 minutes in the presence of 1g/L TiO2 Degussa P25 at pH 5.5. Comparison between various types of catalysts (i.e. Degussa P25, VP Aeroperl, Hombifine N) gave varied results but Degussa P25 was the most effective photocatalyst hence it was selected for this study. For RO16 the optimum catalyst concentration was 0.5 g/L TiO2 with initial concentration of 20 mg/L RO16. It was found that the disappearance of RO16 satisfactorily followed the pseudo first-order kinetics according to Langmuir-Hinshelwood (L-H) model. The rate constant was k= 0.0928 mol/min. Photodegradation of TCC was studied in 70%v acetonitrile: 30%v water solutions. UV light degraded TCC effectively and the reaction rates increased with decreasing initial concentration of TCC. UV/TiO2 gave unsatisfactory degradation of triclocarban (TCC) since only 36% were removed in 60 minutes with initial concentration of TCC 20 mg/L. The degradation of clopyralid and the EDCs was studied using three oxidation systems UV/TiO2, UV/H2O2 and O3. Complete degradation of clopyralid (3,6-DCP) was achieved with UV/TiO2 in about 90 minutes at an optimum catalyst concentration of 1g/L. Zero-order kinetics was found to describe the first stage of the photocatalytic reaction in the concentration range 0.078-0.521 mM. At pH 5 the rate constant was 2.09×10-6-4.32×10-7 M.s-1.Complete degradation of all the three EDCs was achieved with UV/H2O2 in 60 minutes at catalyst concentration of (2.94×10-2 M). On the other hand complete degradation of the EDCs was achieved in just 2 minutes with ozonation. For high concentration EDCs, TiO2/UV gave low efficiency of degradation as compared with ozone and H2O2/UV. First-order kinetics was found to describe the photocatalytic reaction of the EDCs. / Education Service Department of the Libyan Government
|
27 |
Heterogeneous photocatalytic degradation of organic pollutants in water over nanoscale powdered titanium dioxide : the photocatalytic degradation of organic compounds in water (Reactive Orange 16, Triclocarbon, Clopyralid and Estrogens (estrone, 17ß-estradiol, and 17α-ethinylestradiol)) was studied : the reaction kinetics and the effect of the operating parameters on the performance of the system were determined; a comparison with other advanced oxidation processes (O₃, H₂O₂, UV) was also madeMezughi, Khaled M. January 2010 (has links)
Organic contaminants from industrial and/or domestic effluents may be harmful to humans directly or indirectly by degrading the quality of the aquatic environment. Consequently these contaminants must be reduced to levels that are not harmful to humans and the environment before disposal. Chemical, physical and biological methods exist for the removal of these pollutants from effluents. Among the available chemical methods, heterogeneous photocatalytic oxidation has been found particularly effective in removing a large number of persistent organics in water. In this study, photocatalytic degradation was explored for the removal of reactive azo-dye (textile dye), triclocarban (disinfectant), clopyralid (herbicide) and three endocrine disrupting compounds (EDCs) (estrone, 17ß-estradiol and 17α-ethinylestradiol) from synthetic effluents. The major factors affecting the photocatalytic processes including the initial concentration of the target compounds, the amount of catalyst, the light intensity, the type of catalyst, the electron acceptor, the irradiation time and the pH were studied. Other oxidation techniques including (O3, H2O2, UV) were also studied. Generally UV light is used in combination with titanium dioxide, as photocatalyst, to generate photoinduced charge separation leading to the creation of electron-hole pairs. The holes act as electron acceptors hence the oxidation of organics occur at these sites. These holes can also lead to the formation of hydroxyl radicals which are also effective oxidants capable of degrading the organics. The results obtained in this study indicated that photolysis (i.e. UV only) was found to have no effect on the degradation of reactive azo-dye (RO16). However, complete photocatalytic degradation of 20 mg/L (3.24×10-2 mM) RO16 was achieved in 20 minutes in the presence of 1g/L TiO2 Degussa P25 at pH 5.5. Comparison between various types of catalysts (i.e. Degussa P25, VP Aeroperl, Hombifine N) gave varied results but Degussa P25 was the most effective photocatalyst hence it was selected for this study. For RO16 the optimum catalyst concentration was 0.5 g/L TiO2 with initial concentration of 20 mg/L RO16. It was found that the disappearance of RO16 satisfactorily followed the pseudo first-order kinetics according to Langmuir-Hinshelwood (L-H) model. The rate constant was k= 0.0928 mol/min. Photodegradation of TCC was studied in 70%v acetonitrile: 30%v water solutions. UV light degraded TCC effectively and the reaction rates increased with decreasing initial concentration of TCC. UV/TiO2 gave unsatisfactory degradation of triclocarban (TCC) since only 36% were removed in 60 minutes with initial concentration of TCC 20 mg/L. The degradation of clopyralid and the EDCs was studied using three oxidation systems UV/TiO2, UV/H2O2 and O3. Complete degradation of clopyralid (3,6-DCP) was achieved with UV/TiO2 in about 90 minutes at an optimum catalyst concentration of 1g/L. Zero-order kinetics was found to describe the first stage of the photocatalytic reaction in the concentration range 0.078-0.521 mM. At pH 5 the rate constant was 2.09×10⁻⁶ ± 4.32×10⁻⁷ M.s⁻¹. Complete degradation of all the three EDCs was achieved with UV/H₂O₂ in 60 minutes at catalyst concentration of (2.94×10⁻² M). On the other hand complete degradation of the EDCs was achieved in just 2 minutes with ozonation. For high concentration EDCs, TiO₂/UV gave low efficiency of degradation as compared with ozone and H2O2/UV. First-order kinetics was found to describe the photocatalytic reaction of the EDCs.
|
28 |
The effects of estrogenic endocrine disruptors on the osmoregulatory functions in euryhaline fishAl-Jandal, Noura January 2011 (has links)
Osmoregulation is an essential process to maintain water and ionic balance and when euryhaline fish move between freshwater and seawater environments as part of their life cycle this presents additional osmoregulatory challenges. Migrating fish can be exposed in both environments to pollutants such as endocrine disrupting chemicals (EDCs) that include natural hormones (e.g. 17β-estradiol; E2), synthetic hormones (e.g. 17α-ethinylestradiol; EE2), and industrial chemicals (e.g. nonylphenol). The focus of this thesis was to study the effects of different categories of EDCs on the osmoregulatory functions of euryhaline fish such as three-spined sticklebacks (Gasterosteus aculeatus) and rainbow trout (Oncorhynchus mykiss). Osmoregulatory variables (such as osmolality, water and ionic content) were compared in plasma and tissues (white muscle and carcass) of rainbow trout. This validated the use of specific tissue parameters as a surrogate of plasma responses to various osmoregulatory challenges. Waterborne exposure to 17α-ethinylestradiol revealed differential sensitivity of vitellogenesis in the three-spined sticklebacks (no induction) and rainbow trout, but had a significant effect on calcium homeostasis in both species. Intraperitoneal implants of 17β-estradiol reduced CaCO3 production and apparent water absorption in the intestine and increased in tissue calcium stores of seawater-acclimated trout, but fish were able to compensate and showed no overall osmoregulatory disturbance. Waterborne exposure to nonylphenol in freshwater trout was also investigated, but no effects on osmoregulation were found up to 2 ng/l. Overall, estrogens can affect osmoregulation differentially in euryhaline fish species, and sometimes at EDC levels lower than the threshold for reproductive effects (i.e. vitellogenin induction).
|
29 |
Biodegradace 17alfa-ethinylestradiolu enzymy ligninolytických hub / Biodegradation of 17alfa-ethinylestradiol by enzymes of ligninolytic fungiPřenosilová, Lenka January 2012 (has links)
This work is aimed at the study of the effect of 17α-ethinylestradiol (EE2) on the production and characteristics of ligninolytic enzymes (laccase, Mn-dependent peroxidase and lignin peroxidase) in I. lacteus, T. versicolor, P. chrysosporium and P. ostreatus cultures grown on two types of liquid media. Enzyme activity production in fungal cultures was affected by the composition of culture medium. In the case of P. chrysosporium, the addition of EE2 to the complex- medium cultures led to a MnP activity stimulation and simultaneously LiP production was partially repressed in these cultures. In the mineral MM medium, no effect of EE2 on enzyme production by P. chrysosporium was observed. In EE2 treated MM cultures of P. ostreatus lower MnP activities were found when compared to biotic controls. In the case of T. versicolor cultures, the addition of EE2 to the complex medium caused laccase and LiP stimulation in the cultures. In the MM medium, however, only laccase production was affected by EE2. I. lacteus MnP production was partially repressed by EE2 in MM medium. In contrast to that, significantly higher MnP activities were detected in complex- medium I. lacteus cultures after the treatment with EE2. Further EE2 degradation by the fungal cultures was studied. The highest degradation effeciency was...
|
30 |
Metabolismus estrogenů u UGT1A1 deficientních potkanů / Metabolism of estrogene in UGT1A1-deficient ratsMódos, Anna January 2011 (has links)
Introduction Estrogen-induced cholestasis is a disease characterized by a failure of bile flow and bile production. It can develop in women after oral contraceptives use, hormone replacement therapy or during pregnancy. The estrogen metabolism is a complex process leading to formation of metabolites with different biological activities. It takes place primarily in the liver (Phase I and Phase II including hydroxylation, methylation, sulfation and glucuronidation). The enzymes from UDP-glucuronosyltransferases family , abbreviated UGT, are responsible for the glucuronidation of estrogens. Aims The objective of my work is to define estrogen metabolism and gene expression of UGT1A1, CYP1A2 and SULT1A1 and characterize cholestatic liver damage in the UGT1A1 deficient rat strain (Gunn rats) compared to rats with normal enzyme activity and try to define possible mechanisms responsible for the liver damage. Methods Adult female Gunn and corresponding heterozygous rats were treated with ethinylestradiol (EE, 5 mg/kg body weight SC) for 5 days, while control rats received propanediol (vehicle). Day six, the animals were sacrificed and plasma and liver tissue were collected for analysis. Markers of cholestasis and liver damage ALP, AST, ALT and bilirubin were determined using an automatic analyzer, total...
|
Page generated in 0.066 seconds