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Högberg, Helena. "Developmental Neurotoxicity Testing Using In vitro Approaches." Doctoral thesis, Stockholms universitet, Wenner-Grens institut, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-30056.
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There is a great concern about children’s health as the developing brain in foetuses and children is much more vulnerable to injury caused by different classes of chemicals than the adult brain. This vulnerability is partly due to the fact that the adult brain is well protected against chemicals by the blood brain barrier (BBB) and children have increased absorption rates and diminished ability to detoxify many exogenous compounds, in comparison to that of adults. Moreover, the development of the central nervous system (CNS) is a very complex process involving several different important events, e.g. proliferation, migration and differentiation of cells. These events are occurring within a strictly controlled time frame and therefore create different windows of vulnerability. Furthermore, the brain consists of numerous different cell types (neuronal, glial and endothelial cells) that have specific functions. The development of each cell type occurs within a specific time window and is therefore susceptible to environmental disturbances at different time periods. Evidence indicates that exposure to industrial chemicals, pesticides or drugs, contributes to the increasing incidence of neurodevelopment disorders. However, due to lack of studies only a few industrial chemicals have been identified as developmental neurotoxicants so far. The current developmental neurotoxicity (DNT) guidelines (OECD TG 426 and US EPA 712-C-98-239) are based entirely on in vivo studies that are time consuming, complex, costly and not suitable for the testing of a high number of chemicals. Applying alternative approaches such as in silico, in vitro and non-mammalian models as a part of an integrated test strategy, could speed up the process of DNT evaluation and reduce and refine animal usage. Both in vitro and non-mammalian test systems offer the possibility of providing an early screening for a large number of chemicals, and could be particularly useful in characterising the compound-induced mechanism of toxicity of various developmental processes. This thesis has characterised two primary neuronal cultures (cerebellar granule cells (CGCs) and cortical neuronal cultures) and identified them as relevant models for DNT testing, since the key processes of brain development are present, such as cell proliferation, migration and neuronal/glial differentiation. Furthermore, two emerging technologies (gene expression and electrical activity) have been evaluated and were identified as promising tools for in vitro DNT assessment. In combination with other assays they could be included into a DNT intelligent testing strategy to speed up the process of DNT evaluation mainly by prioritising chemicals with DNT potential for further testing.The work of this thesis was performed at ECVAM, European Commission, Italy.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 3: In progress. Paper 4: In progress.
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Lai, Keng Po. "Study on the environmental contamination and mechanistic toxicology of 2,3,7,8-tetrachlorodibenzo-p-dioxin." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/527.
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Yu, Lok Chiu. "Cellular metabolism in in vitro toxicity and toxicology studies." HKBU Institutional Repository, 2005. http://repository.hkbu.edu.hk/etd_ra/675.
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Mitchell, Roger Dale 1955. "Systemic indicators of inorganic arsenic toxicity in several species." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276678.
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Seven prospective biological indicators of systemic toxicity were examined at time points ranging from 15 minutes to 24 hours using male Sprague-Dawley rats, B6C3F1 mice, Golden-Syrian hamsters and Hartley guinea pigs following intraperitoneal dosing with 0.1 mg/kg and 1.0 mg/kg sodium arsenite. Rats and mice were also dosed with 1.0 mg/kg sodium arsenate. Pyruvate dehydrogenase (PDH) activity was significantly depressed at early time points in mice, hamsters and guinea pigs and at later time points in rats dosed with arsenic (III). Rats and mice dosed with arsenic (V) also exhibited PDH depression at early time points. Uroporphyrin and coproporphyrin excretion was elevated in mice following arsenic (III) dosing. Coproporphyrin excretion was elevated in rats following arsenic (V) dosing. Blood glucose, creatinine, urea nitrogen and creatinine were unchanged by arsenic dosing. Based upon the amount and types of biological responses observed, the mouse appears to be the most sensitive animal model for the further study of arsenic toxicity.
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Scanlan, Clare M. "The development of algal-based toxicity testing for biocides used in marine industries." Thesis, Heriot-Watt University, 1985. http://hdl.handle.net/10399/1951.
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Venter, Telanie. "Characterisation, toxicology and clinical effects of crocodile oil in skin products / by Telanie Venter." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9234.
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Natural oils are regularly used in cosmetics and as treatment for numeral skin conditions (Nielsen, 2006:575). The natural products industry is a multibillion dollar industry and has grown tremendously over the past few years. Natural oils used in cosmetics contain a range of fatty acids which contribute to several valuable properties in cosmetic- and personal care products. Fatty acids are divided into saturated acids and unsaturated acids (Vermaak et al., 2011:920,922).
Because of the popularity and wide diversity of skin care products, it is necessary to create products that will distinguish themselves from the rest of the commercial products. To include natural oils in skin care products is a new way to prevent skin ageing, as well as other dermatological conditions. In this study, a natural oil, namely crocodile oil was used.
Crocodile oil is obtained from the fat of the Nile crocodile (Crocodylus niloticus). Crocodile oil has the same composition as human skin oil. It only differs with regard to the percentages of the ingredients present. Crocodile oil contains saturated and unsaturated fatty acids. Because of the similar composition as human skin oil, crocodile oil will rarely be allergenic when applied to human skin and therefore will be a very accepted and harmless product to use (Croc city, 2012).
There are many claims of positive results when crocodile oil containing products have been used. It includes fading of freckles, treatment of acne and pimple marks, dark lines, wrinkles and laugh lines. It also includes vanishing of dark shadows, sun spots and other discolorations. It helps prevent discolorations from forming and makes the skin softer, brighter and more attractive. It also controls rashness and dryness (Croc city, 2012).
Because of crocodile oil’s anti-ageing, anti-fungal and anti-bacterial effects claimed by crocodile oil suppliers, and due to the fact that little scientific data is available on crocodile oil, it was decided to investigate the claims.
In this study, the aims and objectives were to use natural oil, namely crocodile oil, and investigate the fatty acid profile, anti-microbial and anti-fungal activity, anti-oxidant activity, toxicity studies, stability determination of crocodile oil lotion and clinical efficacy testing of the anti-ageing effects.
To determine the fatty acid profile of crocodile oil, fatty acid methyl ester (FAME) analysis with gas chromatography were used. Identification of FAME peaks in the samples was made by comparing the relative retention times of FAME peaks from samples to those of reference standards. The composition of fatty acids in crocodile oil compared well to fatty acids found in human skin oil.
Anti-microbial and anti-fungal tests were done by Envirocare Laboratories, North-West University, Potchefstroom. Staphylococcus aureus, Esterichia coli, Pseudomanas aeruginosa, Candida albicans, Brasiliensis, Propionibacterium acnes and Trichophyton rubrum cultures were used to determine the anti-microbial and anti-fungal activity of crocodile oil. Unfortunately no activity was observed.
The anti-oxidant properties of crocodile oil and crocodile oil lotion were determined by using the most commonly used method for measuring Malondialdehyde (MDA) in biological samples, namely the thiobarbituric acid (TBA) test. This method is based on spectrophotometric quantification of the pink complex formed after reaction of MDA with two molecules of TBA. No anti-oxidant activity was observed in the oil or the lotion.
Toxicity studies were performed by Dr. D. Goosen (BVSc Hons. Pret.) from Tswane University of Technology (Pretoria, South Africa). The studies showed that the lotion had no toxicity in the skin sensitisation, acute dermal toxicity and acute dermal irritation studies.
To determine the stability of the crocodile oil lotion, the formulated products were store at 25 °C / 60% RH (relative humidity), 30 °C / 60% RH and 40 °C / 75% RH for 6 months in the original packaging as well as a glass container. The stability tests included pH, viscosity, visual appearance assessment, zeta-potential, droplet size and mass loss. The crocodile cream lotion was stable over the 6 months period in both containers.
Clinical efficacy testing was performed at the CEL (Clinical Efficacy Laboratory) of the North-West University, Potchefstroom, South Africa. A short-term study over a period of 3 h was performed to investigate the hydrating effects of crocodile oil lotion. A long-term study over a period of 12 weeks was performed to examine the anti-ageing effects of crocodile oil lotion. An erythema study was also conducted to test the anti-erythema properties of crocodile oil lotion. Although the crocodile oil lotion as well as the placebo lotion showed an increase in skin hydration, there was no significant difference between the two treatments. Crocodile oil lotion also showed no anti-erythema properties.Thesis (PhD (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.
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Paul, Richard. "New developments in analytical toxicology for the investigation of drug facilitated crime." Thesis, University of South Wales, 2007. https://pure.southwales.ac.uk/en/studentthesis/new-developments-in-analytical-toxicology-for-the-investigation-of-drug-facilitated-crime(c2b2b4e3-b8c5-471f-bf3b-daca545d4afa).html.
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Drug facilitated assault (DFA) is an increasing problem in the UK. The crime often occurs through the surreptitious administration of a drug into a victims drink, rendering the victim unable to resist the assault. The detection of these drugs in a biological specimen from the victim is one of the most challenging facets of forensic chemistry. Drug concentrations can be very low, as often only a single dose is administered, and the pharmacodynamics of commonly employed drugs further hinders the testing process. The research presented in this work shows the development of several new assays for the detection of flunitrazepam, gamma-hydroxybutyrate (GHB) and ethyl glucuronide (EtG) in a variety of biological matrices. New methods of drug testing in blood and urine are demonstrated, as well as interesting developments in the field of hair testing. Using hair to detect drug exposure allows a much wider window of detection than the more traditional matrices of blood and urine. New methods are presented in this work using gas chromatography-tandem mass spectrometry (GCMS/MS) to detect drugs in hair. Validation data is presented along with the results of authentic DFA testing. All aspects of the drug testing procedure have been evaluated, from new extraction techniques utilising water instead of solvents, to novel clean up stages involving the unique combination of SFE and SPME. Several confirmation techniques are explored including single quadrupole, triple quadrupole and ion trap mass spectrometry. In addition to developing assays for DFA cases, the versatility of this type of analytical chemistry is explored in two population studies. The first study evaluates alcohol consumption between two groups; drugs users and non drug users in medico-legal cases. There is an anecdotal belief amongst drug clinic staff that alcohol use is lower in drugs users than it is in non drug users. This study presents the first scientific confirmation of this belief through EtG (an alcohol metabolite) testing in hair of the two groups. The second study investigates whether there is a correlation between EtG and cocaethylene (a metabolite of cocaine only produced in the presence of alcohol) in cocaine users. Results f this study suggest that there is no positive correlation between the two compounds. The research presented in this thesis aims to further the analytical science surrounding FA investigation and provide accurate, sensitive and reliable methodology for drug esting in blood, urine and hair.
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Al, Jaber Jaber. "Forensic and clinical toxicology studies focusing on drug analysis in hair and other biological matrices." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8507.
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Clinical and forensic toxicology analysts rely heavily in their daily tests on the analysis of the conventional samples (blood and urine). However, these specimens are limited in the time scale they reflect with regard to drug intake history and also in terms of drug stability within the matrices. Alternative matrices such as hair, oral fluids and dried blood spots (DBS) provide new horizons and new opportunities. Drugs incorporated within hair are very stable. Hair also provides a very long detection window, for at least one year, if not a lot longer. Oral fluids on the other hand are non-intrusive, easy to collect and much cleaner sample matrix than blood or urine. DBS also offer great drug stability, are easy to collect, faster to analyse and suitable for automated analysis. However, a number of studies are needed to assess the limits of these alternative samples in terms of the correlation of their results with the results of conventional samples and with regard to drug stability. Such studies will enable a more reliable and confident interpretation of results obtained from these matrices especially for medico-legal purposes. The main aims of this research were: to develop and validate analytical methods for detection and quantitation of drugs of use and abuse in hair, oral fluids, blood and DBS samples, to investigate the correlation between dose and drug concentration in hair, blood and oral fluids after controlled chronic drug administration, to investigate the stability of anti-psychotic drugs in DBS (from patients) stored under different conditions and the effect of addition of preservative, and to investigate the alcohol intake prevalence among Kuwaiti drug addicts and correlate these results with selfreported intake. As the majority of drugs were basic, an extraction method based on methanolic incubation was developed for detection of basic/weak basic drugs in hair. It was compared to alkaline digestion (with NaOH) followed by liquid-liquid extraction (LLE). Detection was achieved by LC-MS/MS (Sciex2000) after separation on a C18 column. When applying both methods on positive authentic hair samples the results showed that the methanolic method was capable of extracting most basic drugs in hair but only partially, while the alkaline digestion method was found to degrade V some unstable drugs like sulpiride, but was capable of fully extracting the alkaline stable drugs such as quetiapine. After development and validation of the LLE-LC-MS(Exactive) method for the analysis of anti-psychotics in blood, oral fluids and hair, an investigation was carried out on the correlation pattern between trough concentrations in those three matrices. The most significant correlation coefficients (r) found were those between blood and hair concentrations, procyclidine r=0.83 (18 subjects p=<0.001), risperidone r=0.96 (14 subjects p=<0.001), haloperidol r=0.90 (10 subjects p=<0.001), OH-risperidone r=0.24 (13 subjects p=>0.44), quetiapine r=0.28 (14 subjects p=>0.33) and chlorprothixene r=0.32 (13 subjects p=>0.32). Among the interesting results was the strong correlation found between drugs half-lives and the mean ratio of hair concentration/dose (r=0.96, p=<0.003). The stability of anti-pyschotics in DBS from patients’ samples was assessed by storing them at four different temperatures (25, 4, -20 and -80°C) with and without prior impregnation of the DBS cards with sodium fluoride. After development and validation of the LLE-LC-MS method, samples were analysed at days 0, 45, 90 and 180. Results showed good stability of all the compounds (procyclidine, quetiapine, risperidone, OH-risperidone, chlorprothixene and haloperidol) in all the different storage conditions and no significant increase or decrease in drug concentrations with sodium fluoride impregnation. Finally, after trials with five different HPLC columns, two SPE cartridges, two LLE extraction procedures and two mass spectrometer instruments, a method was developed and validated for the detection and quantitation of alcohol’s minor and specific metabolite in hair, ethyl glucuronide (EtG). The method has a limit of detection (LOD) of 3pg/mg and lower limit of quantitation (LLOQ) of 9pg/mg. This method was applied to 59 hair samples from patients at a general addiction centre and alcohol prevalence was investigated and its correlation with self-reported use was investigated.
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Everitt, Victoria Jane. "The use of indigenous macroinvertebrates and Daphnia pulex in acute toxicity testing." Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005483.
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Aquatic toxicology has been identified as a valuable tool in the identification and management of chemical pollution in aquatic ecosystems. Standardised methodologies for acute aquatic bioassays have been adopted from international agencies. As a result of these standard methods, the use of laboratory cultured organisms for toxicity testing has been more popular than that of indigenous field-caught organisms. Included in these adopted methods are those for the cultured crustacean Daphnia pUlex. D.pulex is adapted to living in standing water and the suitability of this species to determine toxic effects for South African riverine environments, which are largely flowing, has been questioned. Thus this thesis is a case-study ofthe use of D.pulex and indigenous site-specific macroinvertebrates as toxicity test organisms for setting acute water quality guidelines to protect aquatic ecosystems. The study highlights site-specific problems such as reference sites and organism identification. The acute tolerance of selected indigenous invertebrates was compared to that of D. pulex, using both a single-substance reference toxicant (zinc) and selected whole efiluents. The significance of source population and culture age as a potential source of biological variability between D.pulex cultures was also investigated. D.pulex cultures have been initiated in South Africa from females collected from a number of different local populations; also it is assumed that no genetic change (due to mutation) occurs within a D.pulex culture over time. In order to establish if source population and culture age are a source of biological variability between D.pulex experiments, the acute tolerJuce to zinc of two different D.pulex populations and three different generations within a population were compared. Due to experimental variability results were inconclusive, and differences in tolerance as a result of population difference or culture age could not be determined with confidence. The acute tolerance of D.pulex to a single reference chemical (zinc) and selected whole efiluents was compared to that of selected indigenous invertebrates. Acute 48 h D.pulex zinc tolerance (LC50 range: 0.22 - 0.60 mg/l Zn) was found to be more sensitive than acute 96 h tolerances shown by mayfly species A.fconurus peringueyi (Heptageniidae) (LC50: 17.42 mg/l Zn), Euthrauluselegans (Leptophlebiidae) (LC50: 0.98 mg/IZn), Ba~tidae (LC50: 0.94mg/IZn) and shrimp, Caradina nilotica (Atyidae) (LC50: 3.17 mg/l Zn). This result suggests that guidelines for zinc set using D.pulex will protect the selected indigenous invertebrates. Selected whole eftluents were not acutely toxic to either D.pulex or selected indigenous invertebrates. These experiments were used as a case study for method development regarding the comparative use of D.pulex and indigenous invertebrates in acute whole eftluent toxicity testing. Finally, it is recommended that a suite of indigenous organisms (e.g. macroinvertebrates, fish and algae), as well as laboratory cultured D.pulex, be used in the initial setting of guidelines and that D.pulex be used for routine compliance monitoring. It is futher recommended that a suite of available monitoring methods, such as chemical and biomonitoring methodologies, be used in conjuction with toxicity testing in water quality management.
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Cabrera, Guillermo Lopez Brockman Herman E. "Effect of five dietary antimutagens on the genotoxicity of six mutagens using three different short-term tests." Normal, Ill. Illinois State University, 1993. http://wwwlib.umi.com/cr/ilstu/fullcit?p9416862.
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Thesis (Ph. D.)--Illinois State University, 1993.Title from title page screen, viewed March 7, 2006. Dissertation Committee: Herman E. Brockman (chair), Alan J. Katz, Brian J. Wilkinson, David F. Weber, Radheshyam K. Jayaswal. Includes bibliographical references (leaves 162-177) and abstract. Also available in print.
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Marrara, Adriana Cristina Tomasin. "Avaliação fisico-quimica e ecotoxicologica do Ribeirão Tatu no municipio de Limeira - SP." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257838.
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Orientador: Antonio Roberto SivieroTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: A água é um recurso finito e essencial para todas as formas de vida. Estudos demonstram que diversas doenças podem ser causadas por água contaminada. A crescente urbanização e as atividades antrópicas agravam os níveis de poluição dos corpos d¿água. A bacia do ribeirão Tatu cobre grande parte da área urbana do município de Limeira-SP. Nasce na zona rural do município de Cordeirópolis e deságua no rio Piracicaba. Segundo a Resolução CONAMA 357/2005, o ribeirão é considerado classe 4 na área urbana. Possui inúmeros problemas com o lançamento de efluentes domésticos, industriais e agrícolas sem tratamento adequado, poluição urbana e ausência quase total de matas ciliares. O presente trabalho teve por objetivo realizar uma avaliação ecotoxicológica da água superficial e do sedimento do ribeirão Tatu, no período de março de 2005 a março de 2006, utilizando como bioindicadores de toxicidade aguda o microcrustáceo Daphnia similis e de toxicidade crônica o microcrustáceo Ceriodaphnia dúbia. Também, caracterizar a água em relação as variáveis físico-químicas tais como, temperatura, pH, oxigênio dissolvido (OD), condutividade, dureza, alcalinidade, demanda bioquímica de oxigênio (DBO5), demanda química de oxigênio (DQO), determinando para isso, quatro pontos de coleta ao longo do ribeirão. Os resultados demonstraram as áreas com maior vulnerabilidade com relação à toxicidade, havendo maior toxicidade aguda nos pontos 3 e 4 durante todo o período de avaliação.Os resultados da toxicidade crônica apresentaram os mesmos pontos como os mais afetados por este parâmetro. No mês de junho e julho de 2005 ocorreu queda na qualidade da água do ribeirão, que provavelmente pode estar relacionada a substâncias tóxicas presentes na água por lançamento de efluentes industriais sem tratamento adequado. Com relação as analises físico-químicas da água, a temperatura e o pH estiveram dentro dos padrões aceitáveis pela legislação. O OD diminui a medida que o ribeirão avança para área urbana, caracterizando assim, o aumento da poluição. Os maiores valores de condutividade, dureza foram verificados nos pontos 3 e 4, tais valores podem alterar as atividades biológicas dos organismos aquáticos. Com relação aos valores de DBO5 e DQO, estes indicam a possibilidade de descarte de efluentes industriais sem tratamento adequado
Abstract: Water is a finite and essential resource for all life forms. Studies have shown that many illnesses can be caused by contaminated water. The ribeirão Tatu basin comprises much of the urban area of the county of Limeira, SP, Brazil. It originates in the agricultural zone of the county of Cordeirópolis and empties into rio Piracicaba. According to CONAMA Resolution 357/2005, the river has a classification of 4 in urban area. It has countless problems, such as the release of untreated domestic, industrial and agricultural sewage, urban pollution, as well as an almost total absence of riverside woods. The present study carried out an ecotoxicologycal evaluation of the ribeirão Tatu¿s surface water from March of 2005 to March of 2006, using the microcrustacean Daphnia similis as a bioindicator of acute toxicity and the microcrustacean Ceriodaphnia dubia as a bioindicator of chronic toxicity. In addition to this, the water was characterized in relation to physical an chemical variables, such as temperature, pH, dissolved oxygen (OD), conductivity, hardness, alkalinity, biochemical demand of oxygen (DBO5) and chemical demand of oxygen (DQO). For this, four collection points were determined along the watercourse. The results show the most vulnerable areas in relation to toxicity; point 3 and 4 showing greater acute and chronic toxicity. June an July, a drop in the quality of ribeirão Tatu water was recorded, probably due to the presence of toxic substances in the water, due to the release of untreated industrial sewage. The results of the physical-chemical showed acceptable pH and temperature levels. The dissolved oxygen decreases closer to the urban areas, thus indicating an increase in pollution. The conductivity, hardness and alkalinity values were seen in point 3 and 4. Such values may alter biological activities of aquatic organisms. The values for biochemical an chemical demand of oxygen indicates the possibility of the release of industrial sewage without proper treatment
Doutorado
Saneamento e Ambiente
Doutor em Engenharia Civil
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Chou, Hsun-Wen. "Nanotoxicology from nano titanium dioxide particle size effect on Ceriodaphnia dubia to death mechanism /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 77 p, 2008. http://proquest.umi.com/pqdweb?did=1597633671&sid=14&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Dobbs, Michael G. "Development of a three-trophic level toxicity test utilizing an alga (Chlorella vulgaris), rotifer (Brachinous calyciflorus), and fish (Pimephales promelas)." Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/40164.
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In this research a test system was developed that is designed as a tool to evaluate the potential hazard of chemicals to aquatic ecosystems. The system developed is a linear three-trophic level food chain consisting of an alga (Ch/ore/la vulgaris), rotifer (Brachionus calyciflorus), and fish (Pimephales promelas). The chemostat design used for the lower two trophic levels was crucial in being able to supply the top trophic level with sufficient food on a continuous basis. The system was initially evaluated using copper (Cu) and selenium (Se) as toxicants. In the copper experiments, results of a 7 day threetrophic level toxicity test were compared with a series of single species tests. The LOEC was 31.5 μg/L based on a temporary impairment of the algal population growth, with a corresponding NOEC of 16.2 μg/L. The algal population at all initially impaired treatment levels demonstrated recovery to control levels by the end of the test. Single species tests with the same species showed impairment at treatment concentrations lower than the corresponding value from the three-trophic level test. The difference in sensitivity is attributable to the fact that most of the Cu in the single species tests was in the dissolved form (approximately 80 %), whereas in the trophic level test most of the Cu was not ( < 15 % dissolved Cu). The three-trophic level Se experiment lasted for 25 days, with both short-term and long-term impacts evident. At the algal trophic level, growth was not impaired on a daily basis at any of the exposure levels (110.3, 207.7, and 396.1 pg/L Se). However, algal densities were slightly reduced at the 207. 7 and 396.1 pg Sell treatments, although not significantly different when the data was pooled across days. Rotifer populations were impaired at these same levels by day 4, and succumbed to the Se by day 7. Fathead minnow growth was also impaired at these two concentrations by day 7. In addition, sub lethal impairment of rotifer and fish growth was evident at the 110.3 pg/L level after day 20 indicating a more subtle trophic impact. Bioconcentration factors ranged between 100 and 1000 pg/L and were found to be dependent on the species, treatment, and day.Ph. D.
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Nordberg, Anna. "Priority setting strategies for regulatory testing of industrial chemicals." Licentiate thesis, Stockholm : Philosophy and the History of Technology, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4554.
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Binder, Markus. "An evaluation of recirculating artificial stream designs for acute toxicity testing using two South African Ephemeroptera species exposed to sodium sulphate." Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005376.
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Three artificial stream designs, termed Large Artificial Stream Units (LASUs), Raceways, and Channels, at two major scales (1700 L, 12.5 L and 20 L recirculated volume) were developed at the Institute for Water Research, Rhodes University, Grahamstown, in order to explore the possibilities of using indigenous rheophilic macroinvertebrates in routine toxicity tests. This study compared these systems, using 96h-EC50 values from sodium sulphate toxicity tests as the experimental response. Two local Ephemeroptera (Leptophlebiidae: Adenophlebia auriculata Eaton, and Baetidae: Afroptilum sudafricanum Lestage) were evaluated for their suitability in routine toxicity tests; and the possible effects of elevated salinity levels in South African rivers on the test species were assessed. Two sets of experiments with each mayfly species were conducted, following an unreplicated regression design. Dechlorinated tap water was used as the water source. Experiments in the Channels were repeated to determine experimental variability. Results were compared statistically by testing for overlap of 95% confidence limits (95%Cls) of EC50 values. The differences between A. auriculata EC50 values in the different systems were statistically significant (no overlap of 95%CLs), but they were not more variable than has been considered normal for biological systems (Coefficient of variation 20.1 %; ratio of greatest EC50 / smallest EC50 1.63). The differences were not related to the scale or the average current velocity characteristic of each stream design (average current velocity LASUs - Raceways - Channels 0.090 - 0.083 - 0.038 m/s). The Channels proved to be most efficient with regard to practical performance as they are portable and easily transportable, user-friendly, reliable, splash-free, cost effective to construct, and can easily be adapted to specific requirements. These systems are therefore recommended for regular use. The suitability of the two mayfly species for routine toxicity testing was evaluated. A. auriculata EC50 values showed a significant negative correlation with the corresponding average body-size (range 1476 - 1610 μm, mean 1555 μm). The different average body-sizes probably reflected the abundance of a certain size range present in the Palmiet River at the time of collection. Both species reacted similarly to Na₂S0₄ (similar slopes of the toxicity curves), identifying this salt as a slow acting toxicant. A. sudafricanum populations were more sensitive to Na₂S0₄ (EC50 3.404 g/L) than A. auriculata (EC50 8.090 g/L), probably because of its smaller body-size (mean 709 μm) and a lack of extremely tolerant individuals. In comparison to other freshwater macro invertebrates, including the standard toxicity test organism Daphnia spp., both mayfly species seemed to be moderately tolerant of Na₂S0₄; therefore there was no particular advantage to using these indigenous taxa rather than Daphnia spp. An assessment of the effects of elevated salinity/TDS levels on the test taxa yielded preliminary insights. A NaCI-EC50 for A. sudafricanum could be extrapolated and suggested a higher sensitivity to Na₂S0₄ than to NaCl. When Na₂S0₄ EC50 values of both species were compared to selected TDS levels of South African rivers, 4. auriculata would mostly not be affected, but A. sudafricanum might occasionally suffer from sub-lethal effects, depending on the sulphate proportion of the TDS. The South African guideline for TDS seemed to protect both species sufficiently.
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Reichel, Carmela Marie. "The effects of neonatal manganese exposure on impulsivity, unlearned motoric function, and reward." CSUSB ScholarWorks, 2005. https://scholarworks.lib.csusb.edu/etd-project/2788.
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This study examined the effects of low to moderate doses of manganese (0, 250, or 750 _g per day from PD 1-21) on a comprehensive battery of behaviors in rats during the neonatal period, preweanling period, and in adulthood.
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Rodriguez, Grau Jorge Luis. "Suppression of Immune Functions by PCBs in the Earthworm Lumbricus terrestris." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc798391/.
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This research is part of an effort to develop non-mammalian surrogate immunoessays with the earth worm Lumbricus terrestris to assess immunotoxic potential of xenobiotics to mammals. The objective was to determine if earthworm immunoessays, namely E- and S- rosette formation and phagocytosis, are sensitive to a known mammalian immunotoxin, the PCB Arclor 1254. Results are presented in terms of PCB exposure and tissue concentrations during uptake/depuration.
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Chan, Tsz Chung. "Toxicokinetics of pentachlorophenol, 2,3,4,6-tetrachlorophenol and 2,4,6-trichlorophenol in the golden apple snail (pomacea lineata wagner)." HKBU Institutional Repository, 1994. http://repository.hkbu.edu.hk/etd_ra/31.
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Semones, Molly C. "Regulation and Testing for Marine Biotoxins." Ohio University Honors Tutorial College / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1283867789.
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Burrows, David. "Papain: a Novel Urine Adulterant." Digital Commons @ East Tennessee State University, 2004. https://dc.etsu.edu/etd/950.
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The estimated number of employees in the United Stated screened annually for illicit drugs is approximately 20 million, with marijuana being the most frequently abused drug. Urine adulterants provide an opportunity for illicit drug users to obtain a false negative result on commonly used primary drug screening methods such as the Fluorescence Polarized Immunoassay (FPIA) technique. Typical chemical adulterants such as nitrites are easily detected or render the urine specimen invalid as defined in the proposed federal guidelines for specimen validity testing based on creatinine, specific gravity and pH. Papain is a cysteine protease with intrinsic ester hydrolysis capability. The primary metabolite of the psychoactive chemical in marijuana, 11-norcarboxy-delta-9-tetrahydrocannibinol (THC-COOH), was assayed by FPIA in concentrations ranging from 25 to 500 ng/mL, at pH values ranging from 4.5 to 8, over the course of 3 days with papain concentrations ranging from 0 to 10 mg/mL. FPIA analysis of other frequently abused drugs: amphetamines, barbiturates, benzodiazepines, cocaine, opiates, and phencyclidine, along with gas chromatography/mass spectrometry (GC/MS) of THC-COOH and high pressure liquid chromatography/ultraviolet detection (HPLC/UV) of nordiazepam was performed in order to determine if the mechanism of urine adulteration by papain was analyte specific. Control and adulterated urine specimens (n=30) were assayed for creatinine, specific gravity and pH to determine if papain rendered the specimens invalid based on the proposed federal guidelines. There was a direct pH, temperature, and time dependent correlate between the increase in papain concentration and the decrease in THC-COOH concentration from the untreated control groups (p<0.01). The average 72 hour THC-COOH concentration decrease at pH 6.2 with a papain concentration of 10 mg/mL was 50%. Papain did not significantly decrease the concentration of the other drugs analyzed with the exception of nordiazepam. GC/MS of THC-COOH and HPLC/UV of nordiazepam revealed a 66% and 24% decrease in concentration of the respective analyte with 10 mg/mL papain after 24 hours at room temperature (~23 °C). No adulterated specimens were rendered invalid based on the SAMHSA guidelines. Immediate FPIA analysis is suggested to minimize the interfering effects of papain with regards to primary drug screening.
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Margiotta-Casaluci, Luigi. "Integrated testing strategy for the study of the effects of the human pharmaceutical dutasteride on fish." Thesis, Brunel University, 2011. http://bura.brunel.ac.uk/handle/2438/6341.
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In recent years, a growing number of human pharmaceuticals have been detected in the aquatic environment, generally at low concentrations (sub-ng/L to low μg/L). These compounds are characterised by highly specific mechanisms of action, high potency and prolonged activity in order to minimise dosing requirements and potential toxicity in patients. Among the various classes of pharmaceuticals, steroids and anti-steroids are widely used, as shown by the analysis of their clinical use carried out at the beginning of this Ph.D. project. Although the amounts used are much lower than the amounts of some other pharmaceuticals (e.g. analgesics), their ability to affect important physiological processes in fish (e.g. reproduction) at very low concentrations (ng/L) suggest that this class of compounds should represent a high priority for ecotoxicological research. In particular, this Ph.D. project addressed the question of whether or not dutasteride, a human pharmaceutical mainly used to treat benign prostatic hyperplasia, may cause adverse effects in the teleost fathead minnow (Pimephales promelas) by inhibiting the activity of both isoforms of 5α-reductase (5αR), the enzyme which convert testosterone into dihydrotestosterone (DHT). The theoretical framework used to guide the design of the experimental studies was based on the combination of several conceptual approaches, including the study of the evolutionary degree of conservation and functionality of the drug target in non-target species, and the cross-species extrapolation of pharmacological and toxicological information generated during pre-clinical and clinical studies in mammals during drug development. The results obtained during the first phase of this Ph.D. project strongly suggested that DHT has a physiological role in the fathead minnow. In fact, 5αRs are evolutionary conserved in this species, 5αRs genes are expressed in tissues such as the testis, and DHT circulates in fathead minnow plasma at concentrations similar to those detected in humans. These findings represented the rationale for testing the effects of dutasteride in the fathead minnow. Dutasteride caused significant adverse effects in all the in vivo studies performed in order to evaluate its potential toxicity on fish, including early life stage and short term reproduction studies, and all the tested life stages were sensitive to the inhibition of 5αRs activity; however, none of the observed adverse effects occurred at concentrations of exposure lower than 32 μg/L (measured concentration). The results also showed that female fish are highly sensitive to disruption of the androgenic pathways, highlighting their utility for the evaluation of potential adverse effects caused by anti-androgens on fish. In conclusion, the results presented in this Thesis suggest that, at present, the potential presence of dutasteride in the environment does not represent a risk to wild fish populations, due to the high concentrations required to elict significant adverse effect (LOEC = 32 μg/L) and the low volume of drug prescribed every year (5.07 kg in UK in 2006). However, the high bioaccumulation factor of dutasteride suggest that further studies should be conducted to elucidate the role played by the bioaccumulation process in the toxicity responses observed in fish.
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Thomas, Carolyn L. "Development of a test system for screening toxic substances: a comparison using organic substances." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49941.
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The purpose of this research was to develop a test system for screening toxic substances by predicting their aquatic ecosystem effects. The system studied was a static, one liter microcosm with a diverse species assemblage. Teh microcosm was composed of biotic inoculum, chemically defined medium and sediment. The biotic inoculum cotained primary producers, grazers, carnivores and decomposers. The chemical medium used was Taub #82 modified by adding sodium bicarbonate. Three different types of sediment were studied: sand, clay and clay plus sand.
Four organic chemicals: phenol, triethylene glycol (TEG), quinoline and naphtoquinone were evaluated with this test system. The toxicities of TEG, quinoline and naphthoquinone were compared for each sediment type. Toxicity was evluated in terms of the chemicals' effects on primary productivity and heterotrophic activity though other effects are also noted. The toxicity of the chemicals in this study was compared to those from other toxicological evaluations based on threshhold toxicity values (EC20 and LC50).
The screening test sytem evaluated in this study did not demonstrate significanly different threshhold toxicity values than the other screening systems to which it was compared. The ranking of the toxicants based on EC20 values was different for the two ecosystem properties, net production and heterotrophic activity. Naphthoquinone concentration exhibited no correlation between ecosystems property values and therefore, could not be ranked. Phenol exhibited the greatest toxicity to net production immediately after the toxicant addition. Quinoline was most toxic to net production over the longer time scale. TEG exhibited the least toxicity to net production, however, TEG exhibited higher toxicity to heterotrophic activity than either quinoline or phenol.
Although the type of sediment used in the nicrocosms did not change the relative toxicities of the chemicals, the microcosms with clay sediment always were observed to exhibit lower net production and higher variability.
Nonparametric statistical analyses are recommended for microcosm studies because of the lack of normally distributed data. Confidence limits of 80% are recommended because of the need for biologically conservative estimates of ecosystem toxicity.Ph. D.
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McDonald, Jennifer C. "Bacterial Challenge in Lumbricus Terrestris: A Terrestrial Invertebrate Immunotoxicity Model." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3640/.
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A bacterial challenge assay was developed utilizing the earthworm, Lumbricus terrestris, in order to assess potential immunotoxic effects from exposure to specific polychlorinated biphenyl congeners. Earthworms were inoculated with Aeromonous hydrophila, establishing a 10-day LD50. In vitro assays for effects of PCBs on phagocytosis agreed with mammalian studies, demonstrating potent suppression of phagocytosis by the non-coplanar PCB congener 138 and no suppression by the coplanar congener 126. However, when the effects of the two PCB congeners were evaluated for suppression of resistance to a whole animal infection challenge assay, coplanar PCB 126 decreased the ability of L. terrestris to withstand infection while non-coplanar PCB 138 did not.
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Nicholls-Grzemski, Felicity April. "The effect of short-term pretreatment with peroxisome proliferators on the acute toxicity of various toxicants, including paracetamol /." Title page, table of contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phn6158.pdf.
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Bakand, Shahnaz Safety Science Faculty of Science UNSW. "Development of in vitro methods for toxicity assessment of workplace air contaminants." Awarded by:University of New South Wales. School of Safety Science, 2006. http://handle.unsw.edu.au/1959.4/24246.
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Exposure to air contaminants is significantly associated with both short-term and long-term health effects. However, the precise mechanisms that derive such effects are not always understood. While an extensive background database from in vivo toxicological studies have been developed, most toxicity data is from oral and dermal chemical exposures rather than inhalation exposure. There is a need to explore new alternative approaches to provide toxicity information particularly on this technically demanding area. This research explores the potential of in vitro methods for toxicity assessment of workplace air contaminants. A tiered approach for in vitro toxicity testing of workplace contaminants was designed in which appropriate air sampling and exposure techniques were developed. A diversified battery of in vitro assays including the MTS (tetrazolium salt, Promega), NRU (neutral red uptake, Sigma) and ATP (adenosine triphosphate, Promega) and a multiple human cell system including: A549- lung derived cells; HepG2-liver derived cells, and skin fibroblasts were used. Primarily the application and merits of in vitro methods for prediction of toxicity of selected workplace contaminants including Ammonium hydroxide, Cadmium chloride, Cobalt chloride, Formaldehyde, Glutaraldehyde, Manganese chloride, Mercuric chloride, Sodium dichromate, Sulphureous acid and Zinc chloride was confirmed. To study the toxicity of airborne contaminants an indirect exposure method was established using air sampling techniques followed by static and dynamic direct exposure methods by culturing cells on porous membranes to reveal representative data relating to human airborne exposures. The static method enabled the measurement of an airborne IC50 (50% inhibitory concentration) value for selected volatile organic compounds (VOCs) including: Xylene (IC50 = 5,350-8,200 ppm) and Toluene (IC50 = 10,500- 16,600 ppm) after 1 hr exposure. By implementing the dynamic method, airborne IC50 values were calculated for gaseous contaminants including: NO2 (IC50 = 11 ?? 3.54 ppm; NRU), SO2 (IC50 = 48 ?? 2.83 ppm; ATP) and NH3 (IC50 = 199 ?? 1.41 ppm; MTS). A higher sensitivity of in vitro methods was observed compared to in vivo published data. A range of in vitro bioassays in conjunction with exposure techniques developed in this thesis may provide an advanced technology for a comprehensive risk assessment of workplace air contaminants.
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Ussery, Erin J. "Optimization of Novel Culturing and Testing Procedures for Acute Effects on Acartia Tonsa and Tisbe Biminiensis." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699989/.
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Copepods comprise an ecologically important role in freshwater and marine ecosystems, which is why they are often considered an important ecotoxicological model organism. The International Organization for Standardization’s (ISO) 14669 protocol is the only guideline for the determination of acute toxicity in three European marine copepod species: Acartia tonsa. The goal of this project was to assess the feasibility of establishing and maintaining cultures of Acartia tonsa, as well as to refine current culturing and egg separation methods. Initial culture methodology proved difficult for consistent production of eggs and collection of nauplii. The development of an airlift system for the separation of eggs from nauplii and adults, based on size, successfully increased the availability of eggs, nauplii and adults. The sensitivity and relative conditions of the copepod species was assessed by running a series of 48h acute toxicity tests with the reference toxicants 3,5-dichlorophenol, 4,4’-methylenebis(2,6-di-tert-butylphenol. The acute 48 hour median lethal dose concentration (LC50), the no observed effect concentration (NOEC), and the lowest observed effect concentration (LOEC) was analyzed for the three reference compounds for of A. tonsa.
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Berton, Silvia Mara Haluch. "Estudo da toxicidade de hidrocarbonetos monoaromaticos utilizando Vibrio fischeri, Daphnia magna e Desmodesmus subspicatus." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/834.
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Os hidrocarbonetos monoaromáticos BTEX (benzeno, tolueno, etilbenzeno e xilenos) têm sido utilizados como solventes e estão presentes no ambiente, incluindo o ar, solo e água. Entre os componentes mais tóxicos estão o benzeno e o tolueno. Para uma correta avaliação do efeito desses contaminantes em águas é imprescindível a realização de estudos ecotoxicológicos. O objetivo deste trabalho foi estudar a toxicidade aguda e crônica dos hidrocarbonetos monoaromáticos por BTEX sobre os organismos testes Daphnia magna, Vibrio fischeri, Desmodesmus subspicatus e comparar os resultados com os limites definidos pelas legislações. Foram preparadas soluções aquosas em presença de metanol empregando-se padrões de BTEX-Mix, benzeno e tolueno (isolados). Essas soluções foram empregadas nos testes de ecotoxicidade conduzidos de acordo com metodologias padronizadas pela ABNT. Os resultados mostraram que para os testes com Daphnia magna os valores de CE50(48h) para BTEX-Mix, benzeno e tolueno foram, respectivamente, 1.187,27 μg.L-1, 73,23 g.L-1, 81,58 μg.L-1. Os testes com Desmodesmus subspicatus não apresentaram sensibilidade para o BTEX-Mix até 1000 μg.L-1 e foram obtidos os valores de CI(96h) para benzeno e tolueno, respectivamente, 197,90 g.L-1, 7.270 g.L-1. Com relação à utilização de metodologias padronizadas foi verificado que os ensaios com Daphnia magna apresentaram maior reprodutibilidade. Os resultados dos ensaios com Vibrio fischeri não apresentaram reprodutibilidade principalmente devido à volatilização das amostras. Comparações realizadas entre os valores das legislações e os resultados obtidos nos testes permitiram afirmar que, na maioria dos casos, os valores máximos permitidos estão abaixo do CE50 encontrado no estudo. Para descarte de efluentes em corpo receptor são preocupantes os valores estipulados quando o corpo receptor não possui grande capacidade de assimilar as altas cargas dos monoaromáticos. Para a Portaria 2914/2011 de consumo de água, o valor de 170 μg.L-1 está acima do CE50 e do CE10 encontrado para Daphnia magna, enquanto para a dessendentação de animais conforme o CONAMA 396/08 está abaixo. Os valores internacionais ambientais coincidem e estão abaixo dos valores encontrados, já as referências no Brasil para avaliação de passivos estão acima.The hidocarbonetos monoaromatic BTEX (benzene, toluene, ethylbenzene and xylenes) have been used as solvents and are present in the environment, including air, soil and water. Among the most toxic components are benzene and toluene. For a correct evaluation of the effect of these contaminants in water is essential to carry out ecotoxicological studies. The objective of this work was to study the acute and chronic toxicity of monoaromatic hydrocarbons BTEX represented by tests on organisms Daphnia magna, Vibrio fischeri, Desmodesmus subspicatus and compare with the current laws. Aqueous solutions were prepared in the presence of methanol from patterns of BTEX-Mix, benzene, and toluene (isolated). These solutions were used to ecotoxicity tests according to standard procedures by ABNT. The results showed that in tests with Daphnia magna EC50 values (48h) for BTEX (mix), benzene and toluene were respectively 1187.27 μgL-1, 73.23 μgL-1, 81.58 μgL-1. Tests with Desmodesmus subspicatus showed no sensitivity to the BTEX (mix) until 1000 μgL-1 were obtained and the values of CI (96h) for benzene and toluene, respectively, 197.90 μgL-1, 7,270 μgL-1. With respect to the use of standardized methodologies been found that Daphnia magna assays showed higher reproducibility. The results of tests with Vibrio fischeri showed no reproducibility principally due to volatilization of the samples. Comparisons between the values of laws and the results obtained in tests enabled state that in most cases the maximum allowed values are below the EC50 found in the study. For disposal of effluent in the receiving body are disturbing the values stipulated when the receiver does not have great body ability to absorb the high loads of monoaromatic. For Ordinance number 2914/2011 of water amounts to 170 μgL-1. It is above the EC50 and EC10 found for Daphnia magna, while for tooth loss of animals as CONAMA 396/08 is below. The international environmental values coincide and are below the values found in the references already in Brazil for evaluation of liabilities are above.
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Greenan, Rebecca. "Optimization of the VITROCELL® Exposure System for In Vitro Toxicity Testing of Diesel Emissions at the Air-Liquid Interface." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32254.
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Relative to traditional methods, air-liquid interface (ALI) exposures constitute a superior in vitro model for assessing the toxicological activity of complex aerosols. By removing the medium barrier, aerosols can be delivered to the cells at their apical surface. This project investigated the utility of the commercially available VITROCELL® exposure system for comparative toxicological assessment of complex aerosols (freshly-generated diluted diesel exhaust and simulated urban smog). The system setup was modified to improve control of aerosol properties (temperature and humidity) and cellular responses (dynamic range). Following optimization, cytotoxicity (WST-1 and LDH assays) and expression of selected genes involved in proinflammatory signalling and oxidative stress responses (via quantitative RT-PCR) were quantified following 1 hour aerosol exposures. The results showed only limited, variable responses following exposures to high concentrations of diesel exhaust. Lack of consistent and robust responses are likely due to poor deposition of particulate matter from the test aerosols.
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Mioduski, Janaíne. "Avaliação da toxicidade de extratos da semente de Moringa oleifera LAM. Frente aos organismos Daphnia magna Straus. E Artemia salina Lench." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/964.
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CAPESA utilização de coagulantes naturais no tratamento de água vem sendo uma alternativa cada vez mais empregada a fim de evitar possíveis danos à saúde e ao meio ambiente causados por determinados coagulantes químicos. A Moringa oleifera é uma árvore de múltiplos usos, cujas sementes possuem uma eficiente atividade como coagulante natural. Entretanto, estudos apontam para uma possível toxicidade deste extrato. Baseando-se nisto, o objetivo do presente trabalho foi o de avaliar a toxicidade de três diferentes extratos de M. oleifera (extrato aquoso, extrato salino da semente integral e extrato salino da semente sem óleo) e da água tratada com os mesmos extratos, frente a duas espécies de microcrustáceos utilizadas como bioindicadoras de toxicidade (Daphnia magna e Artemia salina). Nos ensaios de toxicidade aguda dos extratos utilizando D. magna, verificou-se uma CE50 de 314,05 mg.L-1 para o extrato salino da semente integral e 346,76 mg.L-1 para o extrato salino da semente sem óleo. O extrato aquoso não apresentou toxicidade nem mesmo nas maiores concentrações (400 a 600 mg.L-1). Para o organismo A. salina, nenhum dos extratos mostrou-se tóxico. Nos ensaios realizados com a água tratada com os extratos de M. oleifera, foi encontrada toxicidade para D. magna nas frações sobrenadante (CE50=296,02 mg.L-1) e sedimentada (CE50=291,04 mg.L-1) da água tratada com o extrato salino da semente integral. Para a água tratada com o extrato salino da semente sem óleo, da mesma forma encontrou-se toxicidade nas frações sobrenadante (CE50=351,17 mg.L-1) e sedimentada (CE50=342,32 mg.L-1), o que indica que a toxicidade do extrato não é reduzida após a coagulação/floculação/sedimentação. No teste crônico realizado utilizando organismos de D. magna expostos durante 21 dias ao extrato salino da semente integral de M. oleifera, foram observadas alterações nos parâmetros avaliados (mortalidade, fecundidade e crescimento), sendo que quanto maior a concentração testada, maiores os efeitos tóxicos. Ao término dos 21 dias experimentais, havia ocorrido a mortalidade de 100% dos indivíduos expostos às maiores concentrações (10 e 15 mg.L-1). Além disso, houve grande variação na fecundidade entre os grupos. Com base nestes resultados, é possível afirmar que a utilização de elevadas concentrações do extrato de M. oleifera (acima de 300 mg.L-1) pode causar danos agudos ao organismo D. magna. Entretanto, na prática, as concentrações utilizadas deste coagulante são consideravelmente menores, variando principalmente entre 50 e 150 mg.L-1, de acordo com dados da literatura. Da mesma forma, a diluição que ocorreria no meio hídrico dificilmente proporcionaria que a concentração permanecesse elevada, mesmo que grande quantidade do extrato chegasse ao meio ambiente. Com base nisso, é possível afirmar que o uso do extrato da M. oleifera pode ser incentivado, mas desde que utilizado com cautela, evitando-se concentrações elevadas.
The use of natural coagulants for water treatment has been an alternative increasingly employed in order to avoid possible damage to health and the environment caused by certain chemical coagulants. Moringa oleifera is a multipurpose tree whose seeds have an efficient activity as natural coagulant. However, studies point to a possible toxicity of this extract. Based on this, the objective of this study was to evaluate the toxicity of three different extracts of M. oleifera (aqueous extract, saline extract of the whole seed and saline extract of the seed without oil) and water treated with the same extracts, against two species of microcrustaceans used as bioindicators of toxicity (Artemia salina and Daphnia magna). In acute toxicity tests of the extracts using D. magna, there was an EC50 of 314.05 mg.L-1 for the saline extract of the whole seed and 346.76 mg.L-1 for the saline extract of the seed without oil. The aqueous extract showed no toxicity even at the highest concentrations (400 to 600 mg.L-1). For the organism A. saline, none of the extracts proved toxic. In the tests performed with water treated with the extracts of M. oleifera, toxicity was found for D. magna in the supernatant fractions (EC50=296.02 mg.L-1) and sedimented (EC50=291.04 mg.L-1) of treated water with the saline extract of the whole seed. For the treated water with the saline extract of the seed without oil, was found toxicity in the supernatant fraction (EC50=351.17 mg.L-1) and the sedimented fraction (EC50=342.32 mg.L-1), which indicates that the toxicity of the extract is not reduced after coagulation/flocculation. In the chronic test performed using D. magna exposed during 21 days to the saline extract of the whole seed of M. oleifera, changes in the evaluated parameters (mortality, fertility and growth) were observed, and as higher the concentration tested, bigger was the toxicity. At the end of the 21 experimental days, there had been a 100% mortality of individuals exposed to higher concentrations (10 and 15 mg.L-1). Furthermore, there was wide variation in fertility between the groups. Based on these results, we can say that the use of high concentrations of the extract of M. oleifera (above 300 mg.L-1) can cause acute damage for D. magna. However in practice, the concentrations used of this coagulant are considerably smaller, ranging mainly between 50 and 150 mg.L-1, according to literature data. Likewise, the dilution that occur in the aquatic environment, hardly provide high concentration of the extract in the water bodies. Based on this, we can say that the use of the extract of M. oleifera can be encouraged, but if used with caution, avoiding high concentrations.
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Gola, Nontutuzelo Pearl. "The value of locally isolated freshwater micro-algae in toxicity testing for water resource management in South Africa." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017873.
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The ecological position of micro-algae at the base of the aquatic food web makes them critical components of aquatic ecosystems. Their short generation time also makes them useful biological indicators because they respond quickly to changes in environmental condition, enabling timely identification and assessment of water quality changes. The inclusion of micro-algae as indicators in water resource regulation and management in South Africa has started recently, their more extensive use in biomonitoring and ecotoxicology programmes for water resource management would contribute to the South African policy if water resource protection. The standard algal growth inhibition assay with the species Pseudokirchneriella subcapitata is currently used for monitoring toxicity of in-stream and industrial wastewater discharges to freshwater micro-algae. The relevance of the data generated by standard toxicity bioassays has been questioned, since micro-algae in particular are extremely variable in their sensitivity to a range of contaminants and these standard species used may not occur in the local aquatic environment. As a result, international regulatory agencies, have recommended algal growth inhibition tests be changed from a single standard species to tests with a number of species. One recommendation, in addition to the use of standard toxicity tests, is the use of species isolated from the local environment which may be more relevant for assessing site specific impacts. This study investigated the value and application of locally isolated South African freshwater micro-algae in toxicity tests for water resource management and was carried out in three phases. The first phase involved isolating micro-algae from South African aquatic resources. Micro-algae suitable for toxicity testing were identified and selected using as set of criteria. Three (Scenedesmus bicaudatus, Chlorella sorokiniana and Chlorella vulgaris) out of eight successfully isolated species satisfied the prescribed selection criteria and these were selected as potential toxicity test species. The second phase focused on refining and adapting the existing algal toxicity test protocol (the algal growth inhibition assay) for use on the locally isolated algal species. The refinement of the test protocol was achieved by exposing the locally isolated species to reference toxicants in order to assess and compare their growth and sensitivity to the toxicants under the prescribed toxicity test conditions with that of the standard toxicity test species (Pseudokirchneriella subcapitata) and a commercial laboratory species (Chlorella protothecoides). During this phase, one of the three local species (Scenedesmus bicaudatus) was eliminated as a potential toxicity test species due to inconsistent growth. The third phase of the study involved assessing the sensitivity of the two remaining species (C. vulgaris and C. sorokiniana) to a range of toxicants (reference toxicants, salts, effluents and a herbicide) and comparing it to that of the standard toxicity test species P. subcapitata and C. protothecoides. The toxicants were selected based on their relative importance in the South African context, as well as the practicality of using these local micro-algae to routinely determine the impact of these toxicants on local aquatic resources. The growth of the four micro-algae was stimulated by the selected effluents. The standard toxicity test species P. subcapitata was ranked the most sensitive and of the four species to two reference toxicants and two inorganic salts. Chlorella sorokiniana was ranked the most sensitive of the three Chlorella species to two reference toxicants and two inorganic salts. The herbicide stimulated the growth of C. vulgaris while inhibiting the growth of the other species. Pseudokirchneriela subcapitata and C. sorokiniana showed high intra-specific variability in growth, which made it difficult to determine the effective concentrations of the herbicide and therefore compare the sensitivity of the species. This varied response of micro-algal species to toxicants may result in the biodiversity shifts in aquatic ecosystems, and also supports the recommendation of using a battery of different species to support more informed decisions in water resource management.
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Stewart, Susan Michels. "An Evaluation of the Short-Term Embryo-Larval and Seven-Day Larval Test Methods for Estimating Chronic Toxicity of Zinc to the Fathead Minnow (Pimephales promelas)." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc501048/.
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Chronic toxicity of zinc to Pimephales promelas was estimated by conducting replicate static and static-renewal short-term embryo-larval tests and static-renewal seven-day larval tests. The two test methods were highly reproducible. Daily renewal of test solutions had little effect on the toxicity of zinc, however, the stage of development at which exposure was initiated affected the sensitivity of the toxic endpoints measured. The most sensitive and reproducible endpoint in the embryo-larval tests was survival of viable (non-deformed) larvae and in the seven-day larval test was growth of the larvae, which was slightly more sensitive than the embryo-larval test endpoint. The estimated MATC of 0.18 and 0.15 mg/L mean total and mean soluble zinc, respectively, compared well with published results. Because of its advantages and similar sensitivity, the short-term embryo-larval test was recommended for estimating chronic toxicity.
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Chapman, Laurie A. "Interactions of nutrients on methyl mercury toxicity in neuron X spinal chord hybrid cells (NSC-34) and human oligodendrocyte X rhabdomyosarcoma cells (MO3.13)." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36888.
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Exposure to methyl mercury (MeHg) is a global concern. Increased chronic exposure to MeHg among fish and marine mammal consuming populations will increase the risk of prenatal exposure and as a result, the risk of infant brain damage and neurotoxcity. It is therefore important to understand the role of environmental factors, such as nutrition, in determining susceptibility to MeHg toxicity. Three nutrients (selenium (Se), vitamin C and vitamin E) were selected for examination of their interactions with the mechanisms of McHg cytotoxicity in vitro. Two hybrid neural cell lines (M03.13 and NSC-34) were evaluated for their usefulness in the study of MeHg cytotoxicity. Sixteen toxic endpoints were selected for investigation of growth, viability, structure and biochemistry. Both cell lines responded to MeHg exposure in a dose dependent manner for the majority of endpoints suggesting that both MO3.13 and NSC-34 cells undergo structural and biochemical changes during exposure to McHg, but that MO3.13 cells are more sensitive to DNA, mitochondria) membrane damage and glutathione (GSH) depletion and that NSC-34 cells are more sensitive to protein damage and apoptosis. Se exposure lessened the MeHg-induced decrease in DNA and GSH concentrations in both cell lines. In NSC-34 cells, Se also increased F-actin concentrations and prevented an increase in caspase-3 activity. Se may alter the mechanism of cell death by preventing McHg disruption of DNA replication thus maintaining the production and function of peptides (GSH) and protein (polymerized actin) that aid in MeHg detoxification and neural function. In NSC-34 cells, vitamin C prevented the induction of caspase-3 activity and lessened DNA damage and GSH depletion. Vitamin E lessened GSH depletion and lessened G-actin depletion. Both vitamin C and E improved GSH status, but vitamin C also delayed McHg damage of DNA and prevented early signs of apoptosis suggesting these two vitamins interfere with MeHg metabolism by diffe
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Kong, Kai Yip. "Risk assessment of organochlorine pesticides and polycyclic aromatic hydrocarbons in fish collected from fish ponds in the Pearl River Delta." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/531.
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Ditch, Benjamin D. "Thermal decomposition products testing with 1,1,1,2,2,4,5,5,5 nonafluoro-4-trifluoromethyl pentan-3-one (C6 F-ketone) during fire extinguishing." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0106103-152708.
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Soubhia, Paula Christiane. "Período de detecção de canabinóides urinários por imunofluorescência polarizada em população usuária de Cannabis." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/9/9137/tde-02122008-105959/.
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A Cannabis sativa L., conhecida popularmente no Brasil como maconha, tem sido apontada como a droga de uso ilícito de maior consumo no mundo contemporâneo. As análises toxicológicas utilizadas para verificar o seu uso vem ganhando cada vez maior importância em diversos ambientes de trabalho, desportivos, prisões, clínicas para tratamento de farmacodependência, centros de emergência toxicológica, enfermarias de psiquiatria, entre outros. A presença de canabinóides na urina indica o uso de produtos derivados da planta Cannabis. A maioria dos estudos encontrados na literatura especializada se refere ao perfil de eliminação do 11-nor-Δ 9-THC-COOH, principal produto de biotransformação do Δ 9-THC, que, dependendo da sensibilidade e especificidade da técnica analítica utilizada, poderá ser detectado a longo prazo na urina. Uma constante preocupação é determinar o período de detecção, ou seja, o tempo transcorrido desde a interrupção do uso da droga até a obtenção do primeiro resultado negativo na urina. Este trabalho teve como objetivo investigar o período de detecção de canabinóides urinários em uma população usuária de Cannabis, residentes em uma clínica de tratamento, pela técnica de imunofluorescência polarizada, considerando 50 ng/mL como valor de referência. Foi avaliada a influência do padrão de uso da droga no período de detecção de canabinóides. Entre os pacientes estudados, o período de detecção foi de grande variação: de 33 a 498 horas. Não houve correlação estatística relevante entre o período de detecção e as variáveis freqüência de uso, tempo total de utilização e quantidade de cigarros utilizada na última exposição.The marijuana, one of the products originated from the Cannabis sativa L., is the illicit used drug of major consume in the world. The toxicological analysis to verify the use of the drug are increasing importance in several workplaces drug-testing programs, sportive, prisions, drug treatment and rehabilitation clinics, emergency toxicology departments and other. The cannabinoids in urine indicates the exposition of products originated from the Cannabis. An important concern is to determine the detection times of cannabinoids in urine i.e. the time from the use of the drug until the first negative result. Most of the studies in the speciallized literature report the elimination profile of the 11-nor-9-carboxy- Δ 9-tetrahydrocannabinol (THCCOOH), which the primary cannabinoid metabolite. According to those studies, the urinary cannabinoids detection times can be made for a long time depending on the sensibility and accuracy of the methods used. The purpose of this work was estudy the detection time of the urinary cannabinoids in the marijuana users population after drug abstaining, by FPIA, using a 50ng/mL cutoff. The pattern in drug use influence on the urinary cannabinoids detection times was evaluated. The detection time in the studied population ranged from 33 to 498 hours. The statistic correlation between the detection time and the drug use pattern was not significant (p≤ 0,05).
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Jacob, Cynthia Renata de Oliveira [UNESP]. "Efeitos do inseticida fipronil sobre os corpos pedunculados de operárias de Scaptotrigona postica (Hymenoptera, Apidae, Meliponini)." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/87720.
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jacob_cro_me_rcla.pdf: 1789232 bytes, checksum: 4d1aeb62cf1a6763869b8890da8b652a (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Recentemente as abelhas têm sido devidamente valorizadas como importantes polinizadoras de flores silvestres e cultivadas. A densidade populacional de muitos polinizadores tem diminuído devido, principalmente, à intensificação agrícola e ao uso de pesticidas, prejudicando os serviços de polinização. A metodologia clássica para estimar a toxicidade dos produtos químicos para insetos é determinar a dose letal média (DL50) ou a concentração letal média (CL50), podendo então estabelecer doses que sejam mais seguras aos organismos não-alvo ou benéficos. Além dos efeitos de toxicidade aguda, levando a morte das abelhas, doses subletais dos inseticidas podem provocar alterações comportamentais e fisiológicas nos indivíduos, que ao longo do tempo acarretarão em sérios prejuízos na manutenção da colônia. Um dos inseticidas amplamente utilizado é o fipronil, este atua ligando-se aos receptores do ácido gama-aminobutírico (GABA), interrompendo os canais de cloro, resultando na perda de sinalização inibitória neural. Na literatura pode-se encontrar diversos trabalhos que utilizam como modelo principal a abelha Apis mellifera, porém, é importante ressaltar a diversidade existente entre as abelhas nativas no Brasil, os meliponíneos, e sua participação na conservação da biodiversidade, assim como na polinização de áreas de cultivo, o que torna extremamente importante estudos com essa abelha. Com a finalidade de entender como o fipronil interfere morfo e fisiologicamente em abelhas sem ferrão, a região de interesse deste estudo foram os corpos pedunculados, já que estes são centros cerebrais complexos e tidos como local de convergência multisensorial. Para auxiliar no mapeamento metabólico, utilizou-se como marcador a enzima citocromo oxidase e a enzima caspase-3, técnicas utilizadas na observação de atividade neural...
A few decades the bees are considered an important indicator of high environmental sensitivity, and appreciated as important pollinators of wildflowers and cultivated. The population density of many pollinators have declined to harmful levels to pollination services manly due to agricultural intensification and the use of pesticides. The classic methodology of estimating the effects of chemicals for insects is to determine the median lethal dose (LD50) or median lethal concentration (LC50) that can then establish doses that do not harm non-target organisms or beneficial. Besides the effects of acute toxicity, leading to death bees, sublethal doses of insecticides can cause physiological and behavior changes of individuals over time, resulting in serious harm to maintain the colony. One of the widely used insecticides is fipronil, its acts by binding to gamma-aminobutyric acid (GABA) disrupting chloride channels, resulting in loss of inhibitory neural signaling. In the literature one can find several works using as main bee model Apis mellifera, however, it is important to highlight the diversity of Brazilian native bees, the stingless bees, and their participation in biodiversity conversation, as well as in the pollination of cultivated land. In order to understand how fipronil affect morpho and physiologically the stingless bee S. postica, the region of interest in this study were the mushroom bodies, since these are complex brain centers and used as a place of multisensory convergence. This work established the contact LD50 and Ingestion LC50 to the fipronil insecticide for foragers workers stingless bee Scaptotrigona postica in 0.54ng/bee and 0.24ng/μL of the food after 24 hours, respectively, confirming the high toxicity of this phenylpyrazole, in the groups submitted to contact contamination, were identify morphological... (Complete abstract click electronic access below)
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Jacob, Cynthia Renata de Oliveira. "Efeitos do inseticida fipronil sobre os corpos pedunculados de operárias de Scaptotrigona postica (Hymenoptera, Apidae, Meliponini) /." Rio Claro : [s.n.], 2012. http://hdl.handle.net/11449/87720.
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Resumo: Recentemente as abelhas têm sido devidamente valorizadas como importantes polinizadoras de flores silvestres e cultivadas. A densidade populacional de muitos polinizadores tem diminuído devido, principalmente, à intensificação agrícola e ao uso de pesticidas, prejudicando os serviços de polinização. A metodologia clássica para estimar a toxicidade dos produtos químicos para insetos é determinar a dose letal média (DL50) ou a concentração letal média (CL50), podendo então estabelecer doses que sejam mais seguras aos organismos não-alvo ou benéficos. Além dos efeitos de toxicidade aguda, levando a morte das abelhas, doses subletais dos inseticidas podem provocar alterações comportamentais e fisiológicas nos indivíduos, que ao longo do tempo acarretarão em sérios prejuízos na manutenção da colônia. Um dos inseticidas amplamente utilizado é o fipronil, este atua ligando-se aos receptores do ácido gama-aminobutírico (GABA), interrompendo os canais de cloro, resultando na perda de sinalização inibitória neural. Na literatura pode-se encontrar diversos trabalhos que utilizam como modelo principal a abelha Apis mellifera, porém, é importante ressaltar a diversidade existente entre as abelhas nativas no Brasil, os meliponíneos, e sua participação na conservação da biodiversidade, assim como na polinização de áreas de cultivo, o que torna extremamente importante estudos com essa abelha. Com a finalidade de entender como o fipronil interfere morfo e fisiologicamente em abelhas sem ferrão, a região de interesse deste estudo foram os corpos pedunculados, já que estes são centros cerebrais complexos e tidos como local de convergência multisensorial. Para auxiliar no mapeamento metabólico, utilizou-se como marcador a enzima citocromo oxidase e a enzima caspase-3, técnicas utilizadas na observação de atividade neural... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: A few decades the bees are considered an important indicator of high environmental sensitivity, and appreciated as important pollinators of wildflowers and cultivated. The population density of many pollinators have declined to harmful levels to pollination services manly due to agricultural intensification and the use of pesticides. The classic methodology of estimating the effects of chemicals for insects is to determine the median lethal dose (LD50) or median lethal concentration (LC50) that can then establish doses that do not harm non-target organisms or beneficial. Besides the effects of acute toxicity, leading to death bees, sublethal doses of insecticides can cause physiological and behavior changes of individuals over time, resulting in serious harm to maintain the colony. One of the widely used insecticides is fipronil, its acts by binding to gamma-aminobutyric acid (GABA) disrupting chloride channels, resulting in loss of inhibitory neural signaling. In the literature one can find several works using as main bee model Apis mellifera, however, it is important to highlight the diversity of Brazilian native bees, the stingless bees, and their participation in biodiversity conversation, as well as in the pollination of cultivated land. In order to understand how fipronil affect morpho and physiologically the stingless bee S. postica, the region of interest in this study were the mushroom bodies, since these are complex brain centers and used as a place of multisensory convergence. This work established the contact LD50 and Ingestion LC50 to the fipronil insecticide for foragers workers stingless bee Scaptotrigona postica in 0.54ng/bee and 0.24ng/μL of the food after 24 hours, respectively, confirming the high toxicity of this phenylpyrazole, in the groups submitted to contact contamination, were identify morphological... (Complete abstract click electronic access below)
Orientador: Osmar Malaspina
Coorientador: Roberta Cornélio Ferreira Nocelli
Banca: Elaine Cristina Mathias da Silva Zacarin
Banca: Thaisa Cristina Roat
Mestre
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Goetz, Amber Kristina. "Gene Expression Profiling in Testis and Liver of Mice to Identify Modes of Action of Conazole Toxicities." NCSU, 2003. http://www.lib.ncsu.edu/theses/available/etd-11142003-170100/.
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Conazoles are a class of azole fungicides used in both pharmaceutical and agricultural applications. This study focused on 4 conazoles that exhibit a range of carcinogenic and reproductive effects, in order to identify common and unique modes of action. Conazoles target cytochrome P450s (CYPs), and the inhibition and induction of various CYP activities may be part of the toxic modes of action in liver and testis. We used gene expression profiling to characterize a broader range of conazole effects and to identify additional modes of action. Adult male CD-1 mice were dosed daily by gavage for 14 days with fluconazole, propiconazole, myclobutanil or triadimefon (three doses each). Relative liver weight increased following fluconazole and propiconazole exposure, and histological analysis revealed centrilobular hepatocyte hypertrophy in response to all 4 conazoles. No weight or histological changes were observed in testis, and serum testosterone and luteinizing hormone were also unchanged. Microarrays queried expression of 16,475 genes, and identified 2,081 and 1,424 differentially expressed genes in liver and testis, respectively, following conazole exposure. Of these genes, 118 in the liver and 94 in the testis were common to two or more conazoles. The majority of differentially expressed genes related to stress response, oxidative stress, xenobiotic metabolizing enzymes, steroidogenesis or carcinogenesis. Expression profiles between conazoles and between liver and testis affected similar biological pathways, suggesting the potential for common modes of action.
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Qiu, Jianping 1953. "Effects of cyclophosphamide exposure of male rats on progeny outcome and site of action on male germ cell nuclei in the testis and epididymis." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28888.
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Cyclophosphamide is a bifunctional alkylating agent. Administration of low doses of cyclophosphamide to male rats produces severe effects on the outcome of their progeny. The studies in this thesis show that one week treatment with cyclophosphamide can produce about 30% post-implantation loss. This indicates that post-testicular spermatozoa are sensitive to alkylating agents. Previous studies have shown that six weeks treatment caused more than 95% post-implantation loss. The effects of cyclophosphamide treatment on rat spermatozoal nuclei in the testis and epididymis were also addressed in this thesis. Rat cauda epididymal spermatozoa collected after one week of cyclophosphamide treatment showed no change in decondensation pattern in vitro; while samples obtained from rats treated for six weeks showed a slowed chromatin elongation and dispersion pattern. Iodoacetamide binding revealed that there was about a 30% decrease in the amount of free sulfhydryls in spermatozoal nuclei from six weeks treated samples, while there was no detectable change in one week treated samples. DNA single strand breakage was detected in one week treated samples only in the presence of proteinase K in the lysis solution, while significant amounts of both DNA single strand breakage and DNA cross-links were detected in six weeks treated samples. Using a DNA synthesis in vitro system, it was found that six weeks treatment decreased spermatozoal template function, while one week treatment did not result in any significant difference in DNA template function when compared with the control. It is proposed that as the mele germ cells undergo the chromatin transition processes, the chromatin is in an open dynamic status, which expresses many vulnerable sites of the genome to aklylating agent. Since there is no DNA repair system, the alkylation of the genome is cumulative and causes severe damage to the germ cell nuclei; this would lead to early embryo death. Furthermore it is hypothesized that
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Blackburn, Diane M. "Observations of the effects of glycol ether and a nitroaromatic on the testis of the rat." Thesis, Manchester Metropolitan University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292735.
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Melin, Vanessa Estella. "Effects of Quaternary Ammonium Disinfectants on Mouse Reproductive Function." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/74337.
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Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings. While these compounds have been used for decades, reproductive toxicity has not been thoroughly evaluated. Extensive use of QACs results in ubiquitous human exposure to potentially toxic compounds. Reproductive toxicity of two common QACs, alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC), was investigated to determine gender-specific toxicity with an emphasis on male reproductive function. Breeding pairs of mice exposed for six months to ADBAC+DDAC exhibited decreases in fertility and fecundity, with fewer pregnancies and decreased numbers of pups over a six month period. Females proceeded through significantly fewer estrus cycles, and both ovulation and implantation rates were reduced. Males exhibited declines in both sperm concentration and motility. Male reproductive toxicity was further assessed in a series of in-vitro and in-vivo experiments. ADBAC+DDAC were cytotoxic to testicular Sertoli cells in culture at concentrations greater than or equal to 0.0005%. Changes in blood-testis-barrier integrity (BTB) were observed at 0.01% ADBAC+DDAC using a two-compartment culture system that measures transepithelial electrical resistance (TER). Sertoli cell cytotoxicity correlated with decreased TER at ADBAC+DDAC concentrations above 0.001%. In-vitro fertilization capacity of epididymal sperm was reduced in males given a 10-day rest period following ADBAC+DDAC exposure. Multigenerational changes in sperm parameters and in mRNA expression of enzymes involved with epigenetic modifications were evaluated across three generations. Sperm concentration and motility were reduced in F0 males exposed directly to ADBAC+DDAC. In F1 males, sperm concentration was increased and motility decreased, while there was no change in the F2 progeny. Genes involved in epigenetic modifications were altered in the exposed F0, with upregulation of two histone acetyltransferases (Hat1 and Kat2b) and downregulation of one lysine-specific demethylase (Kdm6b). F1 and F2 generations were not different from controls except for downregulation of the methyltransferase Dnmt1 in F1 progeny. The reproductive toxicity of ADBAC+DDAC identified in these studies, particularly to the male, compels further investigation into the potential effects that these compounds may have on human reproduction.Ph. D.
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Bunch, Nathan. "Oral Fluid Method Validation for Bowling Green State University." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1586969951770212.
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Klein, David Michael. "Nucleoside and HIV Drug Transport at the Blood-Testis Barrier." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/581323.
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The immune-reactive sperm are kept separate from the body by epithelial barriers such as the blood-testis barrier (BTB). While these barriers are beneficial for the protection of sperm from toxicants, they can make treating these areas difficult due to preventing the entry of pharmacological agents. This is especially an issue in the treatment of HIV and Ebola infection based on the ample evidence that these viruses are able to survive and spread from within the male genital tract (MGT), but only a few antiviral drugs are known to access the MGT. Transporters that line the epithelial barriers of the MGT, especially the BTB, are important for determining whether or not a drug is able to penetrate into the MGT through transepithelial transport. Several nucleoside analogs (NSA), which are used to treat HIV infection and leukemias, are known to be able to accumulate in seminal plasma, which makes them a useful tool for understanding transepithelial transport for the BTB. The purpose of these studies is to characterize the transport profile for the MGT, in particular the BTB, to gain a better understanding of how xenobiotics, especially ones based on nucleosides, can access the MGT. The chief finding of this work is the discovery of a transepithelial transport pathway expressed by Sertoli cells that allows for the entry of nucleosides (necessary for germ cell development) and NSA into the MGT. This pathway depends on equilibrative nucleoside transporter (ENT) 1 uptake and ENT2 efflux and occurs in both rats and humans. These studies provide the foundation for being able to predict the penetration of novel drugs into the MGT.
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Cornélio, Ana Lívia Gomes [UNESP]. "Avaliação da citotoxicidade, genotoxicidade e bioatividade de cimentos experimentais a base de silicato de cálcio com diferentes radiopacificadores e dos cimentos Biodentine e MTA Plus." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/149225.
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000874521.pdf: 1184298 bytes, checksum: 3c815e7db076a63baa90c4057c3bf4a2 (MD5)Cimentos de silicato decálciosão estudados como materiais reparadores. O estudo foi divido em 4 capítulos: No primeiro, citotoxicidade (MTT e Apoptose), genotoxicidade (teste Cometa) foram avaliadas em Saos-2 para os materiais: Cimentos de silicato de cálcio puro (CSC); Modificado (CSCM); Resinoso (CSCR1, CSCR2 e CSCR3). Na viabilidade, CSC e CSCR3 (50mg/mL) foram citotóxicos. CSCR1, CSCR2 e CSCR3 mostraram maior apoptose. Somente CSC e CSCR2 não foram genotóxicos em 10mg/mL (P<0.05). No cap.2, CSCM e CSCR2, foram associados a radiopacificadores: óxido de zircônio e óxido de nióbio (micro e nano), óxido de bismuto, tungstato de cálcio. MTA foi o controle para citotoxicidade e bioatividade. Todos foram viáveis e apresentaram apoptose semelhantes (1:8). A necrose foi superior (P<0.05). Ambos CSCs induziram fosfatase alcalina (ALP) e ARS. No cap.3, Biodentine (Septodont), MTA Plus (Avalon), CSCRs Nb2O5 e ZrO2 foram analisados quanto à cito e genotoxicidade. No MTT (1, 3 e 7d), todos foram similares. No qPCR, houve expressão de BAX (3d.) para CSCRs, MTAP e CSCR ZrO2 (5d). Para BCL2, (3 e 5d) somente MTAP e CSCR Nb2O5 (5d.). Na genotoxicidade, todos (1:2 e 1:8) permaneceram similares (P<0.05). Cap. 4, os mesmos foram avaliados na bioatividade: MTT, proliferação celular, ALP (1, 3 e 7d), qPCR (alp e ocn), e ARS. Todos os grupos foram viáveis e induziram ALP, ARS e expressão gênica, destacando os materiais CSCR Nb2O5 e Biodentine. Desta forma, os materiais apresentam potencial biológico para ser usado na endodontia. Estudos adicionais devem ser realizados, especialmente para os materiais experimentais.
Calcium silicate-based cements are studied as reparative materials. This study was divided into 4 chapters: In the first, cytotoxicity (MTT and apoptosis) and genotoxicity (Comet assay) were evaluated in Saos-2 for: Pure calcium silicatebased (CSC); Modified (CSCM); resin-based (CSCR1, CSCR2, CSCR3). In the Viability assay, CSC and CSCR3 (50mg/mL) showed lower cell viability. CSCR1, CSCR2, CSCR3 showed more apoptosis. Only CSC and CSCR2 were not genotoxity in 10mg/mL (P<0.05). Chapter 2, CSCM and CSCR2 were associated with radiopacifiers: zirconium oxide and niobium oxide (micro and nano), bismuth oxide and calcium tungstate. MTA was used for the control of cytotoxicity and bioactivity tests. All were viable and showed similar apoptosis (1:8). Necrosis was superior (P<0.05). CSCM and CSCR induced alkaline phosphatase (ALP) and ARS. Chapter 3, was compared Biodentine (Septodont), MTA Plus (Avalon), CSCRs ZrO2 and Nb2O5, on cytotoxicity and genotoxicity. In MTT (1, 3 and 7 days) all were similar. In the qPCR, BAX was expressed by CSCRs (3d). MTAP and CSCR ZrO2 expressed in 5 days. For BCL2 gene (3 and 5d) only MTAP and CSCR Nb2O5 (5d). In genotoxixity assay, all (1:2 and 1:8) were similar (P<0.05). Chapter 4, we evaluated the same materials in Saos2 bioactivity: MTT, cell proliferation, ALP (1, 3 and 7d), qPCR (alp and ocn) and ARS. All groups were viable and induced ALP, ARS and gene expression, particularly CSCR Nb2O5 and Biodentine. Therefore, the biological materials has the potential to be used in endodontics. Additional studies should be conducted, especially for experimental cements. Additional studies should be conducted, especially for experimental cements.
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Cornélio, Ana Lívia Gomes. "Avaliação da citotoxicidade, genotoxicidade e bioatividade de cimentos experimentais a base de silicato de cálcio com diferentes radiopacificadores e dos cimentos Biodentine e MTA Plus /." Araraquara, 2015. http://hdl.handle.net/11449/149225.
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Orientador: Mario Tanomaro FilhoBanca: Idomeo Bonetti Filho
Banca: Joni Augusto Cirelli
Banca: Marco Antonio Húngaro Duarte
Banca: Loise Pedrosa Salles
Resumo: Cimentos de silicato decálciosão estudados como materiais reparadores. O estudo foi divido em 4 capítulos: No primeiro, citotoxicidade (MTT e Apoptose), genotoxicidade (teste Cometa) foram avaliadas em Saos-2 para os materiais: Cimentos de silicato de cálcio puro (CSC); Modificado (CSCM); Resinoso (CSCR1, CSCR2 e CSCR3). Na viabilidade, CSC e CSCR3 (50mg/mL) foram citotóxicos. CSCR1, CSCR2 e CSCR3 mostraram maior apoptose. Somente CSC e CSCR2 não foram genotóxicos em 10mg/mL (P<0.05). No cap.2, CSCM e CSCR2, foram associados a radiopacificadores: óxido de zircônio e óxido de nióbio (micro e nano), óxido de bismuto, tungstato de cálcio. MTA foi o controle para citotoxicidade e bioatividade. Todos foram viáveis e apresentaram apoptose semelhantes (1:8). A necrose foi superior (P<0.05). Ambos CSCs induziram fosfatase alcalina (ALP) e ARS. No cap.3, Biodentine (Septodont), MTA Plus (Avalon), CSCRs Nb2O5 e ZrO2 foram analisados quanto à cito e genotoxicidade. No MTT (1, 3 e 7d), todos foram similares. No qPCR, houve expressão de BAX (3d.) para CSCRs, MTAP e CSCR ZrO2 (5d). Para BCL2, (3 e 5d) somente MTAP e CSCR Nb2O5 (5d.). Na genotoxicidade, todos (1:2 e 1:8) permaneceram similares (P<0.05). Cap. 4, os mesmos foram avaliados na bioatividade: MTT, proliferação celular, ALP (1, 3 e 7d), qPCR (alp e ocn), e ARS. Todos os grupos foram viáveis e induziram ALP, ARS e expressão gênica, destacando os materiais CSCR Nb2O5 e Biodentine. Desta forma, os materiais apresentam potencial biológico para ser usado na endodontia. Estudos adicionais devem ser realizados, especialmente para os materiais experimentais.
Abstract: Calcium silicate-based cements are studied as reparative materials. This study was divided into 4 chapters: In the first, cytotoxicity (MTT and apoptosis) and genotoxicity (Comet assay) were evaluated in Saos-2 for: Pure calcium silicatebased (CSC); Modified (CSCM); resin-based (CSCR1, CSCR2, CSCR3). In the Viability assay, CSC and CSCR3 (50mg/mL) showed lower cell viability. CSCR1, CSCR2, CSCR3 showed more apoptosis. Only CSC and CSCR2 were not genotoxity in 10mg/mL (P<0.05). Chapter 2, CSCM and CSCR2 were associated with radiopacifiers: zirconium oxide and niobium oxide (micro and nano), bismuth oxide and calcium tungstate. MTA was used for the control of cytotoxicity and bioactivity tests. All were viable and showed similar apoptosis (1:8). Necrosis was superior (P<0.05). CSCM and CSCR induced alkaline phosphatase (ALP) and ARS. Chapter 3, was compared Biodentine (Septodont), MTA Plus (Avalon), CSCRs ZrO2 and Nb2O5, on cytotoxicity and genotoxicity. In MTT (1, 3 and 7 days) all were similar. In the qPCR, BAX was expressed by CSCRs (3d). MTAP and CSCR ZrO2 expressed in 5 days. For BCL2 gene (3 and 5d) only MTAP and CSCR Nb2O5 (5d). In genotoxixity assay, all (1:2 and 1:8) were similar (P<0.05). Chapter 4, we evaluated the same materials in Saos2 bioactivity: MTT, cell proliferation, ALP (1, 3 and 7d), qPCR (alp and ocn) and ARS. All groups were viable and induced ALP, ARS and gene expression, particularly CSCR Nb2O5 and Biodentine. Therefore, the biological materials has the potential to be used in endodontics. Additional studies should be conducted, especially for experimental cements. Additional studies should be conducted, especially for experimental cements.
Doutor
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Martinez, Lindsey. "The Optimization of the Nuclear Protein in Testis (NUT) Antibody and its Importance and Impact in the Pathology Lab." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6726.
Full textAbstract:
Optimization in immunohistochemistry is often a time consuming and complex process. There are a varying array of moving parts to consider all while preserving the sensitivity and specificity of the test. When optimizing an antibody it is important to consider the fixation of the tissue and the type of epitope retrieval that would be best suited for the test. The dilution of the primary antibody is a key marker for the efficiency and effectiveness of the laboratory protocol. The purpose of this study was to produce an optimized antibody for the nuclear protein in testis to detect NUT midline carcinoma that provides a sensitive and specific test but is also efficient and can be useful for everyday pathological dedications.
The midline carcinoma defined by the translocation of the NUT gene on chromosome 15q14 that bonds with BRD4 or BRD3 commonly known as NUT midline carcinoma (NMC) is a rapidly aggressive and fatal disease. Commonly a fluorescent in situ hybridization (FISH) test is used to diagnosis this carcinoma. This test takes longer than traditional IHC and can delay the treatment of the patient. Therefore this is why, irrespective of the levels of tumor markers, immunohistochemistry for the NUT marker should be performed in any case where there is poorly differentiated carcinomas that do not have glandular differentiation that come from midline structures.
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Banzato, Thais Petrochelli [UNESP]. "Avaliação da toxicidade reprodutiva da sinvastatina em Ratos machos adultos." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/108459.
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000743622.pdf: 1640934 bytes, checksum: 02da6d91d5c5da0392b723a1d2003011 (MD5)As estatinas são amplamente utilizadas no tratamento da hiperlipidemia e estão entre as drogas com maiores índices de vendas no mundo. Seu efeito se dá através da inibição competitiva da HMGCoA redutase, uma enzima limitante da síntese de colesterol que catalisa a conversão de HMG-CoA em mevalonato, interrompendo a cascata da síntese do colesterol e isoprenóides. Para os ensaios in vitro de reatividade farmacológica, ratos (n = 5) foram eutanaziados e epidídimo, canal deferente, e glândula seminal foram removidos. Após isso, os tecidos foram isolados e montados em câmaras musculares para o registro digital do desenvolvimento da tensão isométrica. Foi construída uma curva concentração- resposta à noradrenalina com a sinvastatina nas concentrações 3, 10, 30 e 100 μM. Não houve alterações na sensibilidade à noradrenalina nos ductos deferente e epididimário entre os grupos. Esses resultados estão relacionados com o não comprometimento da motilidade espermática e tempo de trânsito espermático pelo epidídimo em estudo realizado com animais expostos a 20 e 40 mg/Kg/dia de sinvastatina
Statins are lipid lowering agents extensively used in human clinical medical. They exert their effects through inhibition of HMG-CoA reductase, a crucial enzyme in cholesterol synthesis. Since cholesterol is the precursor of steroid hormones, drugs that decrease cholesterol may damage male reproductive function. Investigate the effects of the exposure to different doses of simvastatin on the reproductive parameters of adult male Wistar rats. Thirty rats were randomly assigned into three groups: simvastatin (20 or 40 mg/kg), control (vehicle - DMSO/oil), and were treated for 30 days orally for evaluation of reproductive parameters after euthanasia. Weight of the reproductive organs; sperm counts, motility and morphology; histopathology; hormonal levels and fertility. The weight of reproductive organs, sperm motility and histopathology analysis were similar among groups. There was a decrease in sperm production and epididymis sperm number, uterus weight with fetuses, implant and live fetuses numbers in simvastatin groups. The animals exposed to simvastatin showed an increase in the pre-implantation loss and sperm with abnormal morphology. The observed effects on reproductive parameters could be associated with toxic effects of simvastatin on spermatogenesis, causing potential damage to male fertility
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Banzato, Thais Petrochelli. "Avaliação da toxicidade reprodutiva da sinvastatina em Ratos machos adultos /." Botucatu, 2013. http://hdl.handle.net/11449/108459.
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Orientador: Wilma De Gravas KempinasBanca: Raquel Fantin Domeniconi
Banca: Glaura Scantamburlo Alves Fernandes
Resumo: As estatinas são amplamente utilizadas no tratamento da hiperlipidemia e estão entre as drogas com maiores índices de vendas no mundo. Seu efeito se dá através da inibição competitiva da HMGCoA redutase, uma enzima limitante da síntese de colesterol que catalisa a conversão de HMG-CoA em mevalonato, interrompendo a cascata da síntese do colesterol e isoprenóides. Para os ensaios in vitro de reatividade farmacológica, ratos (n = 5) foram eutanaziados e epidídimo, canal deferente, e glândula seminal foram removidos. Após isso, os tecidos foram isolados e montados em câmaras musculares para o registro digital do desenvolvimento da tensão isométrica. Foi construída uma curva concentração- resposta à noradrenalina com a sinvastatina nas concentrações 3, 10, 30 e 100 μM. Não houve alterações na sensibilidade à noradrenalina nos ductos deferente e epididimário entre os grupos. Esses resultados estão relacionados com o não comprometimento da motilidade espermática e tempo de trânsito espermático pelo epidídimo em estudo realizado com animais expostos a 20 e 40 mg/Kg/dia de sinvastatina
Abstract: Statins are lipid lowering agents extensively used in human clinical medical. They exert their effects through inhibition of HMG-CoA reductase, a crucial enzyme in cholesterol synthesis. Since cholesterol is the precursor of steroid hormones, drugs that decrease cholesterol may damage male reproductive function. Investigate the effects of the exposure to different doses of simvastatin on the reproductive parameters of adult male Wistar rats. Thirty rats were randomly assigned into three groups: simvastatin (20 or 40 mg/kg), control (vehicle - DMSO/oil), and were treated for 30 days orally for evaluation of reproductive parameters after euthanasia. Weight of the reproductive organs; sperm counts, motility and morphology; histopathology; hormonal levels and fertility. The weight of reproductive organs, sperm motility and histopathology analysis were similar among groups. There was a decrease in sperm production and epididymis sperm number, uterus weight with fetuses, implant and live fetuses numbers in simvastatin groups. The animals exposed to simvastatin showed an increase in the pre-implantation loss and sperm with abnormal morphology. The observed effects on reproductive parameters could be associated with toxic effects of simvastatin on spermatogenesis, causing potential damage to male fertility
Mestre
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Figueiredo, Joana Rita Monteiro. "Toxicity of novel anti-fouling nanomaterials in Marine organismsv." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22019.
Full textAbstract:
Mestrado em Ecologia AplicadaBiofouling is an ecological succession of fouling communities in submerged surfaces that has extensive ecological, environmental and economic impacts worldwide when developed over man-made structures. In order to minimize this problem, biocides with anti-fouling properties are commonly used in protective coatings of submerged structures. Some decades ago, organotin compounds were used as effective anti-fouling agents, however they were completely banned in 2008 due to the toxic and biomagnification effects. As a consequence, a new generation of biocides were developed with lower toxicity and persistence in the environment when compared to organotin compounds. Recently, one of these biocides (DCOIT) was encapsulated in an engineered nanomaterial (silica mesoporous nanocapsules, SiNC-DCOIT) in order to prevent the interaction of biocides with coatings’ ingredients and control their leaching rate during the early lifetime of conventional paints, with environmental and economic benefits. The present study aimed to assess the toxicity of SiNC-DCOIT and a modified version of the engineered nanomaterial including two biocides, the SiNC-DCOIT coated with silver, to marine species and compare its toxicity with the free counterparts (empty SiNC, DCOIT and Ag). Ecotoxicity tests were carried out with eleven marine species, including bacteria (Vibrio fischeri), microalgae (Isochrysis galbana, Nannochloropsis gaditana, Phaeodactylum tricornutum), rotifers (Brachionus plicatilis), bivalves (Cerastoderma edule, Mytilus galloprovincialis), polychaetes (Hediste diversicolor), crustaceans (Artemia salina, Palaemon varians) and echinoderms (Paracentrotus lividus), following standard tests (with some adaptions in some cases). Acute or short-term chronic endpoints were used upon each species and adopted test. Globally, values of L/E/IC50 for SiNC-DCOIT, SiNC-Ag and SiNC-DCOIT-Ag were higher than the estimated values for DCOIT and silver (dissolved in solution), except for some target groups involved in the early fouling stages, proving that these alternative agents are more environmentally-friendly comparatively to free biocides. The obtained L/E/IC50 and NOEC values from the tested compounds were then used to create species sensitivity distributions together with data from literature. The HC5 and PNEC values derivated from these curves showed that the hazard of DCOIT and silver is reduced when encapsulated, highlighting these novel nanomaterials as a promising anti-fouling solution.
A bioincrustação é uma sucessão ecológica de comunidades incrustantes em superfícies submersas que tem extensos impactos ecológicos, ambientais e económicos em todo o mundo quando desenvolvida em estruturas artificiais. Para minimizar esse problema, os biocidas com propriedades anti-incrustantes são comummente utilizados em revestimentos protetores de estruturas submersas. Há algumas décadas atrás, os compostos organoestânicos eram amplamente utilizados como agentes anti-incrustantes eficazes, porém foram definitivamente banidos em 2008 devido a efeitos tóxicos e de biomagnificação reportados. Como consequência, foi desenvolvida uma nova geração de biocidas com menor toxicidade e persistência no meio ambiente em comparação com os compostos organoestânicos. Recentemente, um desses biocidas (DCOIT) foi encapsulado num nanomaterial manufaturado (nanocápsulas de sílica mesoporosas, SiNC-DCOIT), a fim de evitar a interação dos biocidas com os ingredientes dos revestimentos e controlar a sua taxa de libertação durante o início de vida das tintas convencionais, com benefícios ambientais e económicos. O presente estudo teve como objetivo avaliar os efeitos em diversas espécies marinhas do nanomaterial SiNC-DCOIT e de uma versão modificada deste, contendo dois biocidas (SiNC-DCOIT revestido com prata), e comparar a sua toxicidade com os componentes destes nanomateriais (SiNC vazias, DCOIT e Ag). Os testes de ecotoxicidade foram realizados com onze espécies marinhas, incluindo bactérias (Vibrio fischeri), microalgas (Isochrysis galbana, Nannochloropsis gaditana, Phaeodactylum tricornutum), rotíferos (Brachionus plicatilis), bivalves (Cerastoderma edule, Mytilus galloprovincialis), poliquetas (Hediste diversicolor), crustáceos (Artemia salina, Palaemon varians) e equinodermes (Paracentrotus lividus), seguindo testes padrão (com algumas adaptações em alguns casos) ou com protocolos bem definidos. Foram determinados parâmetros agudos ou crónicos de curta duração dependendo da espécie testada e do teste adotado. Globalmente, os valores de L/E/IC50 para SiNC-DCOIT, SiNC-Ag e SiNC-DCOIT-Ag foram superiores aos valores estimados para DCOIT e prata (dissolvidos em solução), com exceção de alguns grupos alvo envolvidos nos primeiros estádios de incrustação, provando assim que estes são agentes alternativos mais amigos do ambiente comparativamente aos biocidas livres. Os valores obtidos de L/E/IC50 e NOEC para os compostos testados foram depois utilizados para derivar curvas de distribuições de sensibilidade de espécies, juntamente com dados da literatura. Os valores HC5 e PNEC derivados dessas curvas mostraram que o perigo do DCOIT e da prata diminui quando encapsulados, destacando que estes nanomateriais inovadores parecem ser uma solução anti-incrustante promissora.
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Lebelo, Segolo Lucky. "The structure of the reproductive system in the male vervet monkey, Chlorocebus Aethiops, with special reference to spermatogenesis." Thesis, Online access, 2007. http://etd.uwc.ac.za/usrfiles/modules/etd/docs/etd_gen8Srv25Nme4_6548_1259920840.pdf.
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