• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 75
  • 10
  • 2
  • 1
  • Tagged with
  • 94
  • 94
  • 67
  • 65
  • 23
  • 21
  • 15
  • 13
  • 12
  • 10
  • 8
  • 8
  • 8
  • 8
  • 7
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

AVALIAÇÃO DA VIABILIDADE DE AMOSTRAS BACTERIANAS EM SUPERFÍCIES ABIÓTICAS COM A INFLUÊNCIA DE FLUÍDOS BIOLÓGICOS / AVALIAÇÃO DA VIABILIDADE DE AMOSTRAS BACTERIANAS EM SUPERFÍCIES ABIÓTICAS COM A INFLUÊNCIA DE FLUÍDOS BIOLÓGICOS / BACTERIAL SAMPLES OF FEASIBILITY ASSESSMENT SURFACE ABIOTIC WITH INFLUENCE BIOLOGICAL FLUIDS / BACTERIAL SAMPLES OF FEASIBILITY ASSESSMENT SURFACE ABIOTIC WITH INFLUENCE BIOLOGICAL FLUIDS

Esteves, Deigilam Cestari 18 December 2014 (has links)
Made available in DSpace on 2016-01-26T18:56:03Z (GMT). No. of bitstreams: 1 Deigilam Cestari Esteves.pdf: 2776358 bytes, checksum: 7e1a46b5b264cbf8e0c0d96e68b501e2 (MD5) Previous issue date: 2014-12-18 / The environmental and hospital infections, caused by bacteria which are resistant to a wide variety of antibiotics, have shown increasing records in the last years, manifesting themselves in high mortality and lethality. Recent researches report that the bacteria presents a survival profile on dry surfaces in order to maintain their virulence when exposed to biological fluids such as urine, saliva and blood. The objective of this study was to document - through laboratorial analysis the survival capacity of the main bacteria of medical interest on abiotic surfaces. The adopted procedures were completely conducted in the microbiology laboratory at Unoeste, in Presidente Prudente SP. Standard ATCC strains of Staphylococcus aureus (ATCC25923), Enterococcus faecalis (ATCC29212), Escherichia coli (ATCC35218), Klebsiella pneumoniae (ATCC700603) and Pseudomonas aeruginosa (ATCC27583) were used, to which biological fluids and water were added. The surfaces were tile, synthetic fabric, mattress and cotton fabric. The surfaces were contaminated with suspension composed by the ATCC strains, biological fluids and water in addition to the control containing only the ATCC strains, which were stored in petri dishes, kept in room temperature. Every seven days the surfaces were dipped in trypticase soy broth and kept in the oven for 24h at 37ºC. They were spread from the contaminated brothin Mueller Hinton agar and kept for 24h in the oven at 37ºC. The viability analysis was done through the colony-forming unity (CFU) counting. For the statistical analysis, the Software R was used, through the Friedman and Kruskal Wallis tests for multiple comparisons, analyzing within each factor (solution or surface) which differ between one another (Friedman s test) and also which treatments interactions are different (Kruskal-Wallis). Through this analysis it was possible to observe that in the current work that Staphylococcus aureus kept its viability for a longer period than other microorganisms under all the tested conditions, presenting significant differences between the fluids and surfaces, with a particular colony growth in blood and cotton. The Klebsiella pneumoniae showed differences between fluids, with saliva containing the highest colony number. With regards to the other tested bacteria, there was no isolated significance. For the multiple comparisons analysis, only the Pseudomonas aeruginosa presented no significant difference between any pair of treatments, whereas the other bacteria presented significant differences between the correlations. The need to analyze the environmental impact of these microorganisms persistence in environments, which are vulnerable to human beings, guides the creation of measures in order to control the spread of pathogenic microorganisms. / As infecções ambientais e hospitalares causadas por bactérias resistentes a um amplo espectro de antibióticos têm índices crescentes nos últimos anos, manifestando-se com alta morbidade e letalidade. Pesquisas recentes evidenciam que as bactérias demonstram um perfil de sobrevivência, em superfícies secas de modo a manter sua virulência quando expostas a fluidos biológicos como urina, saliva e sangue. O objetivo desse estudo foi documentar através de análises laboratoriais a capacidade de sobrevivência das principais bactérias de interesse médico em superfícies abióticas. Os procedimentos foram totalmente realizados no laboratório de microbiologia da Unoeste em Presidente Prudente - SP., utilizando cepas padrão ATCC de Staphylococcus aureus(ATCC25923), Enterococcus faecalis (ATCC29212), Escherichia coli(ATCC35218), Klebsiella pneumoniae(ATCC700603) e Pseudomonas aeruginosa(ATCC27583), ao qual foram adicionados fluídos biológicos e água. As superfícies utilizadas foram piso, tecido sintético, colchão e tecido algodão. As superfícies foram contaminadas com suspensão composta pelas cepas ATCC, fluídos biológicos e água, além do controle contendo somente as cepas ATCC, armazenadas em placas de petri e mantidas em temperatura ambiente. A cada sete dias as superfíciesarmazenadas foram mergulhadas em caldo Tripscaseína de Soja (TSB), colocadas na estufa por 24h a 37ºC. Foram semeados do caldo contaminado em ágar Mueller Hinton e mantidos por 24h em aquecimento a 37º em Estufa.A análise da viabilidadefoi realizada através da contagem de unidade formadora de colônias (U.F.C.). Para a análise estatística utilizou o software R, realizando os testes de Friedman e de Kruskal Wallis para comparações multiplas, analisando dentro de cada fator (solução ou superfície) quais diferem entre si (Teste de Friedman) e, também, quais interações de tratamentos são diferentes (Kruskal-Wallis). Através dessas análises foi possível observar no presente trabalho que Staphylococcus aureus manteve a viabilidade por tempo maior que os outros microrganismos em todas as condições testadas, apresentando diferença significativa entre os fluídos e as superfícies, tendo sangue e tecido algodão crescimento de maior número de colônias. A Klebsiella pneumoniae apresentou diferença entre os fluídos, sendo asaliva com maior número de colônias. Para as outras bactérias testadas não houve significância isoladamente. Para as análises de comparações múltiplas somente para a Pseudomonas aeruginosanão houve diferença significativa entre algum par de tratamentos, as outras bactérias apresentaram diferenças significativas entre as correlações. A necessidade de analisar o impacto ambiental da persistência desses microrganismos em ambientes vulneráveis ao ser humano, norteia o delineamento de medidas para o controle na disseminação de microrganismos patogênicos.
52

AVALIAÇÃO DA VIABILIDADE DE AMOSTRAS BACTERIANAS EM SUPERFÍCIES ABIÓTICAS COM A INFLUÊNCIA DE FLUÍDOS BIOLÓGICOS / AVALIAÇÃO DA VIABILIDADE DE AMOSTRAS BACTERIANAS EM SUPERFÍCIES ABIÓTICAS COM A INFLUÊNCIA DE FLUÍDOS BIOLÓGICOS / BACTERIAL SAMPLES OF FEASIBILITY ASSESSMENT SURFACE ABIOTIC WITH INFLUENCE BIOLOGICAL FLUIDS / BACTERIAL SAMPLES OF FEASIBILITY ASSESSMENT SURFACE ABIOTIC WITH INFLUENCE BIOLOGICAL FLUIDS

Esteves, Deigilam Cestari 18 December 2014 (has links)
Made available in DSpace on 2016-07-18T17:46:20Z (GMT). No. of bitstreams: 1 Deigilam Cestari Esteves.pdf: 2776358 bytes, checksum: 7e1a46b5b264cbf8e0c0d96e68b501e2 (MD5) Previous issue date: 2014-12-18 / The environmental and hospital infections, caused by bacteria which are resistant to a wide variety of antibiotics, have shown increasing records in the last years, manifesting themselves in high mortality and lethality. Recent researches report that the bacteria presents a survival profile on dry surfaces in order to maintain their virulence when exposed to biological fluids such as urine, saliva and blood. The objective of this study was to document - through laboratorial analysis the survival capacity of the main bacteria of medical interest on abiotic surfaces. The adopted procedures were completely conducted in the microbiology laboratory at Unoeste, in Presidente Prudente SP. Standard ATCC strains of Staphylococcus aureus (ATCC25923), Enterococcus faecalis (ATCC29212), Escherichia coli (ATCC35218), Klebsiella pneumoniae (ATCC700603) and Pseudomonas aeruginosa (ATCC27583) were used, to which biological fluids and water were added. The surfaces were tile, synthetic fabric, mattress and cotton fabric. The surfaces were contaminated with suspension composed by the ATCC strains, biological fluids and water in addition to the control containing only the ATCC strains, which were stored in petri dishes, kept in room temperature. Every seven days the surfaces were dipped in trypticase soy broth and kept in the oven for 24h at 37ºC. They were spread from the contaminated brothin Mueller Hinton agar and kept for 24h in the oven at 37ºC. The viability analysis was done through the colony-forming unity (CFU) counting. For the statistical analysis, the Software R was used, through the Friedman and Kruskal Wallis tests for multiple comparisons, analyzing within each factor (solution or surface) which differ between one another (Friedman s test) and also which treatments interactions are different (Kruskal-Wallis). Through this analysis it was possible to observe that in the current work that Staphylococcus aureus kept its viability for a longer period than other microorganisms under all the tested conditions, presenting significant differences between the fluids and surfaces, with a particular colony growth in blood and cotton. The Klebsiella pneumoniae showed differences between fluids, with saliva containing the highest colony number. With regards to the other tested bacteria, there was no isolated significance. For the multiple comparisons analysis, only the Pseudomonas aeruginosa presented no significant difference between any pair of treatments, whereas the other bacteria presented significant differences between the correlations. The need to analyze the environmental impact of these microorganisms persistence in environments, which are vulnerable to human beings, guides the creation of measures in order to control the spread of pathogenic microorganisms. / As infecções ambientais e hospitalares causadas por bactérias resistentes a um amplo espectro de antibióticos têm índices crescentes nos últimos anos, manifestando-se com alta morbidade e letalidade. Pesquisas recentes evidenciam que as bactérias demonstram um perfil de sobrevivência, em superfícies secas de modo a manter sua virulência quando expostas a fluidos biológicos como urina, saliva e sangue. O objetivo desse estudo foi documentar através de análises laboratoriais a capacidade de sobrevivência das principais bactérias de interesse médico em superfícies abióticas. Os procedimentos foram totalmente realizados no laboratório de microbiologia da Unoeste em Presidente Prudente - SP., utilizando cepas padrão ATCC de Staphylococcus aureus(ATCC25923), Enterococcus faecalis (ATCC29212), Escherichia coli(ATCC35218), Klebsiella pneumoniae(ATCC700603) e Pseudomonas aeruginosa(ATCC27583), ao qual foram adicionados fluídos biológicos e água. As superfícies utilizadas foram piso, tecido sintético, colchão e tecido algodão. As superfícies foram contaminadas com suspensão composta pelas cepas ATCC, fluídos biológicos e água, além do controle contendo somente as cepas ATCC, armazenadas em placas de petri e mantidas em temperatura ambiente. A cada sete dias as superfíciesarmazenadas foram mergulhadas em caldo Tripscaseína de Soja (TSB), colocadas na estufa por 24h a 37ºC. Foram semeados do caldo contaminado em ágar Mueller Hinton e mantidos por 24h em aquecimento a 37º em Estufa.A análise da viabilidadefoi realizada através da contagem de unidade formadora de colônias (U.F.C.). Para a análise estatística utilizou o software R, realizando os testes de Friedman e de Kruskal Wallis para comparações multiplas, analisando dentro de cada fator (solução ou superfície) quais diferem entre si (Teste de Friedman) e, também, quais interações de tratamentos são diferentes (Kruskal-Wallis). Através dessas análises foi possível observar no presente trabalho que Staphylococcus aureus manteve a viabilidade por tempo maior que os outros microrganismos em todas as condições testadas, apresentando diferença significativa entre os fluídos e as superfícies, tendo sangue e tecido algodão crescimento de maior número de colônias. A Klebsiella pneumoniae apresentou diferença entre os fluídos, sendo asaliva com maior número de colônias. Para as outras bactérias testadas não houve significância isoladamente. Para as análises de comparações múltiplas somente para a Pseudomonas aeruginosanão houve diferença significativa entre algum par de tratamentos, as outras bactérias apresentaram diferenças significativas entre as correlações. A necessidade de analisar o impacto ambiental da persistência desses microrganismos em ambientes vulneráveis ao ser humano, norteia o delineamento de medidas para o controle na disseminação de microrganismos patogênicos.
53

Padronização de ténica para recuperação de ovos de Toxocara canis em solo / Padronization of technique for recovery of Toxocara canis in soil

Magoti, Luciana Puga 29 August 2008 (has links)
Made available in DSpace on 2016-07-18T17:53:18Z (GMT). No. of bitstreams: 1 Dissertacao Luciana Puga.pdf: 175865 bytes, checksum: ab5d65c8bd35ac9dbd8f2cc6697281da (MD5) Previous issue date: 2008-08-29 / The purpose of this study was to standardize a flotation technique for the recovery of Toxocara canis eggs from soil, comparing different steps. The tests were done under standardized conditions on 1 g of previously sterilized soil samples contaminated experimentally with 200 eggs of T. canis. The following variables were evaluated in serial steps: sieving; type of wash; time of stirring; resuspention of sediment; solution flotation. Centrifuge-flotation in sodium nitrate (d= 1,20) was adopted as an initial technique, using Tween 80 (0.2%) and decinormal sodium hydroxide as solutions for washing the samples. Ten tests were made to compare the variables, using counting in triplicate. The sieving of the material reduced the recovery of eggs in a significant difference (p<0.001) and the number of eggs recovered were higher when the sediment was resuspended (p<0.05). After standardization, flotation solutions sodium chloride, zinc sulphate, sodium dichromate, magnesium sulphate, and sodium nitrate (d= 1,20) were compared. There was a significant difference between zinc sulphate and sodium chloride (p<0.05). In conclusion, the chance of recovering T. canis eggs from samples using flotation solutions can be increased by using resuspended sediment. On the other hand, the sieving procedure can drastically reduce the number of eggs. / O objetivo do estudo foi padronizar uma técnica para recuperação de ovos de ascarídeos (Toxocara canis) em solo, com a comparação de diferentes etapas. Amostras de solo foram previamente esterilizadas e divididas em alíquotas de um grama, sendo contaminadas com 200 ovos. Após a contaminação, foram comparadas, em etapas seriadas, as variáveis: filtragem, tipo de lavagem e re-suspensão do material. Como ponto de partida para comparação, utilizou-se uma técnica com lavagem de solo em Tween 80 (0,2%) e solução de hidróxido de sódio 0,1N; re-suspensão; e centrífugo-flutuação em solução de nitrato de sódio (d=1.20). Os ovos recuperados foram contados com 10 repetições, com três leituras para cada repetição. A filtragem reduziu significativamente a recuperação de ovos em relação ao material não filtrado (p<0,001), enquanto o número de ovos foi significativamente maior quando utilizada a re-suspensão do material (p<0,05). Após padronização, comparou-se as soluções de cloreto de sódio, dicromato de sódio, nitrato de sódio, sulfato de zinco, sulfato de magnésio, havendo diferença entre sulfato de zinco e cloreto de sódio (p<0,001). Dessa forma, as chances de recuperação de ovos de T. canis podem ser ampliadas pelo re-suspensão do sedimento, enquanto que a filtragem reduz consideravelmente o número de ovos.
54

Comparação de métodos para recuperação de ovos de Toxocara spp. em amostras de solo / Comparison of different techniques to recover Toxocara spp. Eggs from soil samples

Batista, Aline da Silveira 16 August 2018 (has links)
Submitted by Michele Mologni (mologni@unoeste.br) on 2018-11-23T17:01:02Z No. of bitstreams: 1 Aline da Silveira Batista.pdf: 165848 bytes, checksum: c187bcd430f8b370d46748116a9de117 (MD5) / Made available in DSpace on 2018-11-23T17:01:02Z (GMT). No. of bitstreams: 1 Aline da Silveira Batista.pdf: 165848 bytes, checksum: c187bcd430f8b370d46748116a9de117 (MD5) Previous issue date: 2018-08-16 / The objective of this study was to compare the efficiency of different techniques to recover Toxocara spp. eggs from artificially and naturally contaminated soil samples. In the first stage, soil samples (n= 12 samples of 1g) were artificially contaminated with 100 eggs of T. canis. Three techniques were used: 1) centrifugal-sedimentation after soil filtration in a series of four sieves, using distilled water (300, 212, 90, and 63 μm); 2) centrifugal-flotation with zinc sulfate (d= 1.35 g/cm3) after sieving; and, 3) centrifugal-flotation with zinc sulfate without sieving. The recovery of eggs using technique 1 was significantly superior to the other techniques, with 78.25%, 16.33%, and 10.92% positivity, respectively. In the second stage, soil samples from 15 public squares/parks were evaluated over a period of 6 months, comparing the more efficient techniques in stage 1 (techniques 1 and 2). The recovery of eggs by technique 1 was more efficient. In the three out of the 6 months evaluated, there was a significant difference in the mean number of eggs recovered, using the technique of centrifugal-sedimentation with sieving. The technique is low cost, easy to implement, and does not require solutions which present environmental risks for its execution. / O objetivo do estudo foi comparar a eficiência de três técnicas de recuperação de ovos de Toxocara spp., a partir de amostras de solo artificialmente e naturalmente contaminadas. Na primeira etapa, amostras de solo (n= 12 amostras de 1g) foram contaminadas com 100 ovos de T. canis. Foram utilizadas três técnicas: 1) centrifugo-sedimentação após filtragem do solo em série de quatro tamises (300, 212, 90 e 63 μm); 2) centrifugo-flutuação com sulfato de zinco (d = 1.35 g/cm3) após tamisação; e, 3) centrifugo-flutuação com sulfato de zinco sem tamisação. A recuperação de ovos pela técnica 1 foi significativamente superior às demais, com 78,25%; 16,33% e 10,92% de positividade, respectivamente. Em uma segunda etapa, foram avaliadas amostras de solo de 15 praças e parques públicos de Presidente Prudente, São Paulo, durante um período de 6 meses, com comparação das técnicas 1 e 2. A recuperação de ovos pela técnica 1 mostrou ser mais eficiente. Em três meses avaliados, houve diferença significativa na média dos ovos recuperados. A técnica de tamisação centrifugo-sedimentação mostrou maior eficiência na recuperação de ovos de Toxocara spp. em relação as outras técnicas. A técnica é de baixo custo, fácil execução e não requer soluções com riscos ambientais para sua execução.
55

Exploring inappropriate glove use in long term care

Burdsall, Deborah Patterson 01 July 2016 (has links)
Healthcare personnel (HCP) frequently wear gloves when they care for patients in Standard Precautions to prevent contact with potentially infectious blood or body fluids. When HCP use gloves appropriately they reduce the risk of cross-contamination and decrease the risk of healthcare-associated infections (HAI). However, if HCP use gloves inappropriately they may inadvertently spread pathogens to patients and the patients’ environment. This study used a descriptive structured observational design to investigate three aspects of HCP glove use in a United States long-term care facility (LTCF). First, the PI examined the degree of inappropriate HCP glove use in a random sample of 76 HCP. Results indicate that the HCP used gloves inappropriately, failing to change gloves 66% of the time when a glove change was indicated. Over 44% of the HCP gloved touch points were defined as contaminated. Second, the PI examined the reliability of a new glove use tool (GUST). Results indicate the GUST is a reliable tool when used by trained observers documenting HCP glove use during toileting and perineal care events in LTCF, with intraclass correlation coefficients (ICC 2,1) over 0.75 for indicators of inappropriate glove use. Third, exploratory analysis indicated significant differences between inappropriate glove use in females and males. Female HCP had significantly more failed glove changes and contaminated touch points than male HCP in this study (p = 0.003). Future research studies should assess US HCP glove use to provide data needed for development of strategies to improve HCP glove use and reduce HAI.
56

The Development of Alternative Green Sample Preparation Approaches for Analysisof Unconventional Environmental Pollutants

Emmons, Ronald V. 15 June 2023 (has links)
No description available.
57

Dynamique spatio-temporelle de la contamination environnementale par Toxoplasma gondii / Spatio-temporal dynamics of the environmental contamination by Toxoplasma gondii

Gotteland, Cécile 19 December 2013 (has links)
La toxoplasmose, dûe au parasite Toxoplasma gondii, est une zoonose dite à cycle complexe car le pathogène fait intervenir plusieurs espèces pour assurer sa transmission. Les félidés sont les hôtes définitifs de T. gondii et, lorsqu’ils sont infectés, peuvent excréter des millions d’oocystes dans l’environnement. L’ensemble des animaux à sang chaud, y compris l’homme, constituent les hôtes intermédiaires. L'infection des différents hôtes s'effectuent par transmission verticale ou via l'ingestion de tissus animaux contaminés ou d'oocystes présents dans l'environnement.Les objectifs de ma thèse étaient i) de mesurer la fréquence et la distribution spatiale des oocystes de T. gondii dans l’environnement en milieu rural, ii) d'estimer la prévalence et la distribution spatiale de l’infection dans la communauté locale de rongeurs, iii) de déterminer les principaux facteurs responsables de la structuration spatiale de la contamination environnementale et enfin, iv) d’évaluer l'importance de l'environnement en tant que source de contamination tant pour les animaux que pour l’homme.Nous avons mis en évidence une forte contamination des sols (29%) distribuée sur l'ensemble de la zone et, avons révélé un gradient spatial similaire de diminution de la contamination avec la distance aux bâtiments au niveau des sols et dans la communauté de rongeurs. Le modèle de simulation multi-agents a permis d'expliciter le rôle prépondérant de la configuration de l'habitat humain, qui de par son effet sur la structuration spatiale des populations de chats domestiques, détermine la fréquence et la distribution des points chauds de contamination. Par conséquent, en milieu rural, l'importante contamination des sols au niveau des fermes suggère que le risque d’infection pour l’homme est élevé, indirectement à travers la consommation de viande issue d’animaux d’élevage infectés, mais aussi directement via l’ingestion d’oocystes présents sur les substrats manipulés lors de diverses activités. / Toxoplasmosis, caused by the parasite T. gondii, is a zoonosis with a complex life cycle as the pathogen requires several different species to achieve it cycle. Felids, in particular domestic cats, are the definitive hosts of the parasite and when infected they can shed millions of oocysts in the environment. All warm blooded animals, including humans, are potential intermediate hosts. Host species can be infected through vertical transmission or by ingesting contaminated tissues or oocysts present on environmental substrates.My goals were: I) to precisely measure the frequency and spatial distribution of the environmental contamination to T. gondii in a rural area, ii) to estimate the prevalence and the spatial distribution of the parasite in the local community of rodents, iii) to identify the main factors driving the spatial structure of the environmental contamination and finally, iv) to assess the importance of the environment as a transmission source for animals and humans.First, we found a high frequency of contaminated soil samples (29%) that were largely distributed across the whole area, and, we found a similar spatial gradient of decreasing contamination with increasing distances from buildings for soils and rodents. Altogether, the results obtained allowed to identify and rank the determinants of the spatio-temporal dynamics of the environmental contamination to T. gondii. The agent-based model showed the primary role of the spatial configuration of human habitat, which, through its impact on the spatial structure of domestic cat populations, determines the frequency and distribution of the hot spots of soil contamination. Thus, in rural areas, the high level of contamination within and around agricultural buildings suggests that infection risks for humans are important, either indirectly through the consumption of contaminated meat or directly due to the ingestion of oocysts contaminating earth, water or vegetables.
58

Blood lead levels in First Grade South African children : A geographic & temporal analysis

Mathee, Angela 04 November 2008 (has links)
Lead is a toxic heavy metal that has been extensively used in modern society, causing widespread environmental contamination, even in isolated parts of the world. There is now overwhelming evidence associating lead exposure with wideranging health effects, including reductions in intelligence scores, hyperactivity, shortened concentration spans, poor school performance, violent/aggressive behaviour, hearing loss, delayed onset of puberty, anaemia, and in severe cases, coma and death. In recent years consensus has been reached in respect of the absence of a threshold of safety for key health effects associated with lead exposure, and the permanent and irreversible nature of many of the health and social consequences of exposure to lead. The public health problem of environmental lead exposure has been widely investigated in developed countries such as the United States of America where, since the 1970s, policies and interventions have been followed by significant reductions in blood lead levels amongst children. In developing countries, and in African countries in particular, there is a relative dearth of information on the sources, mechanisms of exposure and blood lead distributions in children, and little action has been taken to protect children against lead poisoning. This study was undertaken to determine the current distribution of blood lead concentrations, and associated risk factors, amongst selected groups of first grade school children in the South African urban settings of Cape Town, Johannesburg 7 and Kimberley, a lead mining town (Aggeneys) and two rural towns in the Northern Cape province. A further objective of the study was to compare blood lead distributions determined in the current study with the findings of similar studies undertaken prior to the introduction in 1996 of unleaded petrol in South Africa. The results show that over the past decade, blood lead concentrations amongst first grade school children have declined considerably, but that large proportions of children, especially those living or attending school in impoverished areas, continue to have intolerably high blood lead concentrations, within a range that puts them at risk of detrimental health and social outcomes. The major sources of exposure to lead in the samples studied were leaded petrol, lead-based paint used to decorate homes and schools, lead solder used in “cottage industries” and other home-based lead-related activities, as well as the transfer of lead particles from lead-related work settings into homes. Recommendations for policy and relevant interventions for the South African context are discussed.
59

Priorização de fármacos em água destinada ao consumo humano baseada em avaliação da toxicidade e do comportamento ambiental por  meio de modelos computacionais (in silico) para fins de gestão ambiental / Prioritization of pharmaceuticals in water intended for human consumption based on toxicity and environmental fate assessment by in silico models for environmental management purposes

Santos, Carlos Eduardo Matos dos 17 April 2015 (has links)
Introdução: É cada vez mais preocupante a escassez de água e a qualidade dos recursos hídricos. Nas últimas décadas diversos estudos têm apontado a presença de fármacos em água destinada ao consumo humano, caracterizando a existência de rotas de exposição que podem representar riscos para a saúde humana e meio ambiente. Devido a escassez de dados sobre o comportamento ambiental e toxicidade na exposição crônica a baixas doses a fármacos, sua ocorrência em água é uma preocupação para comunidade científica, reguladores e população. Diversos estudos recentes têm sugerido critérios para a definição de fármacos prioritários, ou seja, abordagens com componentes ou fatores que atribuem grau de relevância aos contaminantes. Devido aos altos custos e necessidade de testes adicionais, uma das alternativas propostas para avaliação do comportamento ambiental e toxicidade têm sido os modelos in silico. Objetivos: Estudar o comportamento ambiental e o potencial de toxicidade de ingredientes farmacêuticos ativos(IFAs) para fins de identificação de contaminantes prioritários por meio da aplicação de ferramentas computacionais e modelos in silico. Métodos: Foram selecionados fármacos considerados relevantes para o Brasil conforme critérios de inclusão específicos. Para os fármacos selecionados, foram realizadas buscas de dados experimentais em bases de dados de agências internacionais e predições de propriedades físico-químicas, transporte e mobilidade no ambiente, persistência, bioacumulação e toxicidade, através de modelos in silico e ferramentas desenvolvidas pela USEPA e OECD: EPISuite (v 4.1, EPA, 2011), PBT Profiler (EPA, v.2.0, 2012) TEST© - Toxicity Estimation Software Tool (v.4.1, EPA, 2012) e QSAR Toolbox (v.3.2, OECD de 2013). Foi utilizado o método de priorização do software ToxPi GUI (Carolina Center for Computational Toxicology/Universidade da Carolina do Norte), para obtenção de um Índice de Prioridade Toxicológica (Toxicological Priority Index-ToxPi) e definição dos agentes prioritários com base nos resultados das predições e dados da literatura Resultados: Foram obtidos dados e predições de propriedades físico-químicas, transporte e mobilidade no ambiente, persistência, bioacumulação e toxicidade para os 39 IFAs selecionados. Com base nestes dados, foi obtido um perfil de priorização baseado no ToxPi. Conclusão: Fármacos de diferentes classes podem apresentar características físico-químicas e de comportamento ambiental que lhes conferem alto potencial de exposição ambiental, e apesar do uso seguro nas condições posológicas, há diversos ingredientes ativos com potencial de toxicidade e que podem representar alta preocupação em exposições crônicas As ferramentas computacionais podem ser uma importante ferramenta para avaliação do comportamento ambiental e da toxicidade e identificação preliminar de agentes prioritários. / Introduction: It is a subject of more concern the shortage of water and quality of water sources. For the past decades a variety of studies have pointed the presence of pharmaceuticals in water intended for human consumption, characterizing routes of human and environmental exposure over potential health risks. Due to lack of environmental fate and toxicity data on chronic exposure to low doses of pharmaceuticals, their occurrence in water worries the scientific community, regulators and population. Many recent studies have suggested criteria for the definition of prioritary pharmaceuticals, i.e. approaches of components and factors that attach the relevance of contaminants. Also due to high costs and the necessity for additional tests, one of the alternatives suggested for the assessment of environmental fate and toxicity are in silico models. Objective: To study the environmental fate and the potential of toxicity in active pharmaceutical ingredients (API) in order to identify the prioritary contaminants through the application of computational tools and in silico models. Methods: Pharmaceuticals considered relevant to Brazil were selected according to specific inclusion criteria. For selected pharmaceuticals, experimental data searches were made in databases of international agencies and predictions of physicochemical, transport and mobility properties in the environment, persistence, bioaccumulation and toxicity, through in silico models and tools developed by the USEPA and OECD: EPISuiteTM (v 4.1, EPA, 2011), PBT Profiler (EPA, v.2.0, 2012) TEST© Toxicity Estimation Software Tool (v.4.1, EPA, 2012) and QSAR Toolbox (v.3.2, OECD, 2013). The priorization method of software ToxPi GUI (Carolina Center for Computational Toxicology/University of North Carolina) was used in order to obtain a Toxicological Priority index - ToxPi and a definition of prioritary agents based on results of the predictions and data from literature. Results: Data and predictions of physicochemical, transport and mobility properties in the environment, persistence, bioaccumulation and toxicity were obtained to the 39 selected APIs. It was obtained a profile of priorization based on ToxPi with these data. Conclusion: Different classes of pharmaceuticals may have physicochemical and environmental fate properties that give them high potential of environmental exposure, and in spite of the safe use in posological conditions, there are several active ingredients with toxicity potential that may represent high concern in chronic exposures. The computational tools may be an important tool for environmental fate and toxicity assessments in order to identify preliminary prioritary agents.
60

Determinação de hormônios e antimicrobianos no Rio Piracicaba e testes de toxicidade aguda com Daphnia magna / Determination of hormones and antimicrobials in Piracicaba River and acute toxicity tests to Daphnia magna

Torres, Nádia Hortense 21 March 2014 (has links)
É crescente a utilização de fármacos mundialmente, principalmente devido às inúmeras doenças existentes, tanto humanas quanto para a criação de animais. Contudo, estes compostos podem causar um grande impacto no ambiente, pois são descarregados nos cursos d\'água através dos efluentes. Com isto, os fármacos podem contaminar também o solo e o sedimento, devido ao fato de serem desenvolvidos para apresentarem propriedades persistentes, como é o caso dos antimicrobianos e hormônios. Estes poluentes foram encontrados em estudos com água superficial, subterrânea, solo e sedimento em concentrações que variaram de ng.L-1 a \'mü\'g.L-1, e são capazes de provocar alterações no sistema endócrino de muitos organismos aquáticos, resistência microbiana, além de prejuízos à saúde humana. Assim, este trabalho teve como objetivos realizar um levantamento bibliográfico sobre os aspectos relacionados à presença de fármacos no ambiente, e as metodologias de detecção dos mesmos em amostras ambientais. Assim como determinar a presença de hormônios (estriol, estrona, 17\'beta\' -estradiol, 17\'alfa\'- etinilestradiol, progesterona e testosterona) e antimicrobianos (ciprofloxacina, norfloxacina, eritromicina e enrofloxacina) em amostras de água superficial e tratada; e também analisar a toxicidade destes antibióticos e hormônios em Daphnia magna. E, de acordo com o levantamento bibliográfico, concluiu-se que é necessário um aumento no volume de estudos destes compostos no ambiente, e principalmente, uma avaliação dos efeitos sinérgicos destes compostos nos organismos que têm contato com as matrizes ambientais como água, solo e sedimento. Para a detecção dos fármacos em amostras de água superficial e tratada, amostras foram coletadas ao longo do Rio Piracicaba (6 pontos) e em uma residência na cidade de Piracicaba, de março de 2011 a dezembro de 2012. Para as análises foi utilizado um cromatógrafo líquido acoplado a um espectrômetro de massas com fonte de ionização electrospray (LC-ESI-MS/MS). E, de acordo com os resultados obtidos algumas amostras apresentaram contaminação com os hormônios estriol, estrona, progesterona, 17\'beta\'-estradiol, e o 17\'alfa\'-etinilestradiol foram detectados em algumas das amostras durante o período de coleta, e suas maiores concentrações foram de 90, 28, 26, 137 e 194 ng.L-1, respectivamente, e com o antimicrobiano norfloxacina (variando de 8 a 18 ng.L-1), indicando aporte de esgoto sanitário em alguns pontos no Rio Piracicaba. Os resultados indicaram pouca toxicidade dos antimicrobianos norfloxacina, sulfadiazina e eritromicina, e do hormônio estriol, para a Daphnia magna / There is a growing use of drugs worldwide due to the numerous diseases both human and in animal husbandry. However, these compounds can have a big impact on the environment as they are discharged into waterways via wastewater. With this, drugs can also contaminate soil and sediment due to the fact that they are developed for presenting persistent properties, as is the case of antibiotics and hormones. These pollutants were found in studies with surface water, groundwater, soil and sediment concentrations from ng.L-1 to \'mü\'g.L-1, being able to cause changes in the endocrine system of many aquatic organisms, microbial resistance, and damage to human health. Thus, this study aimed to conduct a literature survey on the aspects related to the presence of pharmaceuticals in environment, and methods of detection thereof in environmental samples. As determine the presence of hormones (estriol, estrone, 17\'beta\'-estradiol, 17\'alfa\'-ethinylestradiol, progesterone and testosterone) and antimicrobials (ciprofloxacin, norfloxacin, enrofloxacin and erythromycin) on surface samples and treated water, and also assess toxicity of antimicrobials and hormones in Daphnia magna. And, according to literature review, it was concluded that an increase in studies volume of these compounds in environment, and especially, a review of synergistic effects of these compounds in organisms that have contact with environmental matrices such as water, soil and sediment. For detection of drugs in surface and treated water samples were collected from March 2011 to December 2012, at 6 points along the Piracicaba River and in one point was collected treated water in a residence in the city of Piracicaba, São Paulo, Brazil. For analyzes a liquid chromatograph coupled to a mass spectrometer with electrospray ionization source (LC-ESI-MS/MS) was used. And according to results obtained some samples were contaminated by hormones estriol, estrone, progesterone, 17\'beta\'-estradiol and 17\'alfa\'- ethinylestradiol during the collection period, and its highest concentrations were 90, 28, 26, 137 and 194 ng.L-1, respectively, and with antimicrobial norfloxacin (ranged from 8 to 18 ng.L-1), indicating inflow of sewage at some points in Piracicaba River. Results indicated little toxicity of antimicrobials norfloxacin, sulfadiazine and erythromycin, and the hormone estriol, for Daphnia magna

Page generated in 0.172 seconds