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Post-partum testosterone administration partially reverses the effects of perinatal cadmium exposure on sexual behavior in rats

Couto-Moraes, Renato; Felício, Luciano Freitas; Oliveira, Claudio Alvarenga de; Bernardi, Maria Martha
Fonte: Pontificia Universidade Católica do Rio de JaneiroUniversidade de BrasíliaUniversidade de São Paulo Publicador: Pontificia Universidade Católica do Rio de JaneiroUniversidade de BrasíliaUniversidade de São Paulo
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.1%
This study investigated the effects of perinatal cadmium exposure on sexual behavior, organ weight, and testosterone levels in adult rats. We examined whether immediate postpartum testosterone administration is able to reverse the toxic effects of the metal. Forty pregnant Wistar rats were divided into three groups: 1) control, 2) 10 mg kg-1 cadmium chloride per day, and 3) 20 mg kg-1 cadmium chloride per day. These dams were treated on gestational days 18 and 21 and from lactation 1 to 7. Immediately after birth, half of the offspring from the experimental and control groups received 50 μl (i.p.) of 0.2% testosterone. Male sexual behavior, histological analysis and weight of organs as well as serum testosterone levels were assessed. Results showed that both cadmium doses disrupted sexual behavior in male rats, and postnatal treatment with testosterone reversed the toxic effects of 10 mg kg-1 cadmium and attenuated the effects of 20 mg kg-1 cadmium. Body weight and absolute testis, epididymis, and seminal vesicle weight were decreased by the higher cadmium dose, and testosterone supplementation did not reverse these effects. Serum testosterone levels were unaffected by both cadmium doses. No histological changes were detected in all organs analyzed. Maternal cadmium exposure effects in sexual parameters of male rat offspring were explained by the altered masculinization of the hypothalamus. We suggest that cadmium damaged cerebral sexual differentiation by its actions as an endocrine disruptor and supported by the changes discretely observed from early life during sexual development to adult life...

Biossorção de cádmio por linhagens de Aspergillus sp; Biosorption of cadmium by Aspergillus sp. strains

Pallu, Ana Paula de Souza
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/04/2006 PT
Relevância na Pesquisa
37.12%
Os metais pesados representam o maior resíduo industrial contaminante de solos, plantas e animais no ecossistema, causando graves efeitos tóxicos ao homem principalmente devido a sua ampla distribuição no ambiente, que tem sido intensificado pela industrialização. Um dos metais pesados mais tóxicos é o cádmio, elemento bastante utilizado em processos industriais, o que o torna um importante contaminante ambiental. Pesquisadores preocupados com problemas associados à poluição ambiental por metais pesados iniciaram estudos com técnicas de biorremediação utilizando microrganismos explorando a capacidade desses na remoção de íons tóxicos do ambiente, dentre eles os fungos. Dentre os vários processos utilizados na remediação do cádmio dos efluentes industriais, um dos mais promissores é a biossorção. Essa técnica tem por base a propriedade dos metais se ligarem a vários materiais biológicos, tais como algas, leveduras, fungos, bactérias e plantas; para retenção, remoção ou recuperação de metais pesados de um ambiente líquido. Dentro desse contexto o fungo Aspergillus sp. foi estudado quanto à sua capacidade de biossorção de cádmio. As pesquisas com Aspergillus sp. demonstram que linhagens dessa espécie possuem grande resistência ao cádmio. No presente trabalho foram avaliados parâmetros para a biossorção de cádmio em soluções artificiais com a utilização de biomassa de duas linhagens do fungo Aspergillus sp. (MSE e CadG1). Dentre estes parâmetros...

Transporte de cádmio em células branquiais do caraguejo de mangue Ucides cordatus; Cadmium transport in gill cells of the mangrove crab Ucides cordatus

Ortega, Priscila
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/07/2012 PT
Relevância na Pesquisa
37.13%
O Ucides cordatus é um caranguejo que habita mangues. Estas regioes podem ser contaminadas com o cádmio, através de dejetos de indústrias e descarte de pilhas e baterias, atingindo o animal por meio de suas brânquias. Assim, o objetivo da dissertação foi verificar a cinética de transporte do cádmio com o uso de inibidores específicos, e sua interação com o cálcio, zinco e ATP. Para isso, as brânquias foram separadas em anteriores e posteriores, e as células foram dissociadas pelo método de dissociação enzimática; a seguir, as células foram marcadas com Fluo 3 am e realizada a cinética de transporte no espectrofluorímetro, adicionando-se concentrações de 0,5, 1,0 e 1,5μM de sulfato de cádmio (CdSO4), cloreto de cádmio (CdCl2), cádmio + cálcio, cádmio + zinco, cálcio e zinco para verificar a interação do Cd com cálcio ou zinco. Posteriormente, houve a adição dos inibidores como vanadato, amilorida, ouabaina e BAPTA às células, e, novamente, efetuou-se o transporte de cádmio nas concentrações 0,5, 1,0 e 1,5μM. Em seguida, adicionou-se ATP e efetuou-se o transporte de cádmio nas mesmas concentrações citadas anteriormente. Os resultados mostraram um transporte de cádmio sigmoidal, quando em presença de CdSO4...

Leveduras como bioindicadores de cádmio no solo; Yeasts as indicators of cadmium in soil

Tavares, Ana Claudia Lo Buono
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/06/2013 PT
Relevância na Pesquisa
37.12%
Devido à ampla utilização do cádmio nas indústrias, muitos solos encontram-se contaminados. Vários estudos com bioindicadores estão sendo realizados para detectar cádmio em solos, sendo a maioria com minhocas (Eisenia fetida) e plantas, contudo estes testes são laboriosos e longos. Os micro-organismos tem se mostrado uma alternativa promissora para esta aplicação, pois são de fácil cultivo e manutenção, além de apresentarem uma rápida resposta às alterações ambientais. Desta forma, o objetivo deste trabalho foi utilizar diferentes gêneros de leveduras como bioindicadores de cádmio no solo. Para tanto foram avaliadas dezoito linhagens de leveduras, das quais foram selecionadas três quanto à sensibilidade na presença de cádmio. A levedura Torulopsis utilis var. thermophilus (IZ214) apresentou alta sensibilidade, a Candida utilis (IZ300) sensibilidade mediana e Saccharomyces cerevisiae (Pedra) a menor sensibilidade. O crescimento foi avaliado por espectrometria, através de leituras de D.O. e pela técnica do Trifeniltetrazólio (TTC) para avaliação da viabilidade celular. O uso do TTC mostrouse mais adequado nos bioensaios com leveduras evidenciando as células metabolicamente ativas. Foi avaliado o crescimento das leveduras em extratos de solo com cádmio obtidos pelo extrator CaCl2 0...

Influência do ph da água de beber na gênese da alteração óssea por cádmio: estudo experimental em ratos; The influence of the pH of the drinking water in the bone alteration origin caused by cadmium: experimental study in rats

Neves, Cynthia Der Torossian Torres
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/03/2015 PT
Relevância na Pesquisa
37.08%
O cádmio (Cd) é um metal pesado e dos mais abundantes elementos encontrados no ambiente. Existem evidências de sua relação coma osteopenia, osteoporose, e osteomalacia e fragilidade do tecido ósseo. Este estudo visa avaliar o efeito do pH da água de beber na gênese da alteração óssea provocada pela intoxicação por cádmio. Neste estudo, foram utilizados90 ratosWistar (Ratus Norvegicus albinus), adultos, machos,divididos em 6 grupos, aos quais foram administrados: A -solução de cloreto de Cd(400mg/L) com pH neutro (pH 7,0); B -solução de cloreto de Cd(400mg/L) com pH ácido (pH 5,0); C -solução de cloreto de Cd(400mg/L) com pH básico (pH 8,0). D -pH ácido (pH 5,0); E -pH básico (pH 8,0); F -pH neutro (pH 7,0). Nofêmur esquerdo de cada rato avaliou-se a densidade óssea, por meio do densitômetro de dupla emissão (DEXA), ensaiosbiomecânicos e escala de HU na tomografia computadorizada espiral.Os resultados demostram que a densidade óssea reduziunos grupos que receberam cádmio e no grupo sem administração de cádmio para o pH 5 ocorreu uma redução da densidade mineral óssea (DMO) e do conteúdo mineral ósseo (CMO). A rigidez biomecânica mostrou-se aumentada para o grupocom pH 5 sem cádmio. Como conclusão geral o cádmio reduziu a densidade óssea.; The cadmium (Cd) is a heavy metal...

Early Changes Induced by Short-Term Low-Dose Cadmium Exposure in Rat Ventral and Dorsolateral Prostates

Lacorte, Livia M.; Delella, Flávia Karina; Amorim, Elaine M. Porto; Justulin, Luis A.; Godinho, Antonio F.; Almeida, Alaor A.; Pinheiro, Patricia F. Felipe; Amorim, Renee L.; Felisbino, Sergio L.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 988-997
ENG
Relevância na Pesquisa
37.08%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Processo FAPESP: 06/60115-2; Processo FAPESP: 06/54265-1; Prostate cancer (PCa) is the most commonly diagnosed cancer in men. The etiology of PCa in humans is multifactorial and includes age, ethnicity, environmental factors, and other unknown causes. Epidemiological and experimental evidence has shown that cadmium is associated with PCa both in humans and rodents. This metal can act as an endocrine disruptor during prostate development, and it induces prostate lesions late in life. In this study, we investigated the effects of low-dose cadmium on rat prostate morphology during puberty. Two-month-old male Wistar rats were randomized into two experimental groups: cadmium-treated and control. The ventral and dorsolateral prostates were dissected, weighed, and immunohistochemically stained with specific antibodies against Ki-67 and the androgen receptor (AR). The concentration of cadmium was measured in the blood and prostate, and testosterone concentration was measured from the plasma. Our results show that cadmium concentration was increased in both the blood and the prostate of cadmium-treated rats...

Effect of α-tocopherol on superoxide radical and toxicity of cadmium exposure

Novelli Filho, José Luiz V. B.; Novelli, Ethel Lourenzi Barbosa; Manzano, M. Anastácia; Lopes, Ana M.; Cataneo, Ana C.; Barbosa, Lais L.; Ribas, Bartoloḿ O.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 125-134
ENG
Relevância na Pesquisa
37.08%
Contamination with cadmium compounds poses high potential risk for the health of populations and for this reason the treatment of their toxic effects should urgently be established. The present study was carried out to determine whether α-tocopherol intake can protect tissues against damage induced by cadmium, and to clarify the contribution of superoxide radicals (O 2 -) in this process. Cadmium chloride was tested for tissue damage by a single intraperitoneal injection of Cd 2+ ions (2 mg Kg -1). To determine the potential therapeutic effect of vitamin E, a group of Cd 2+-treated rats received a drinking solution of α-tocopherol (40 mg l -1) for 15 days. Cadmium induced increased serum creatinine and total lactate dehydrogenase, reflecting renal and cardiac damage. The increased lipoperoxide and decreased Cu-Zn superoxide dismutase levels indicated the generation of superoxide radicals in cadmium-treated rats. Tocopherol induced increased serum high-density lipoprotein and depressed the toxic effects of Ca 2+ alone, since creatinine and lactate dehydrogenase determinations were recovered to the control values. Tocopherol decreased lipoperoxide and led the superoxide dismutase activities to approach those of the control values. We concluded that superoxide radicals are produced as mediators of cadmium toxicity. Tocopherol possesses a significant anti-radical activity and inhibits the cadmium effect on superoxide dismutase activity. Tocopherol also protected tissues from the toxic effects of cadmium by a direct antioxidant action which decreased lipoperoxide formation.

Mimosa (Mimosa caesalpiniifolia) prevents oxidative DNA damage induced by cadmium exposure in Wistar rats

Dias Silva, Marcelo Jose; Vilegas, Wagner; Silva, Marcelo Aparecido da; Gomes de Moura, Carolina Foot; Pidone Ribeiro, Flavia Andressa; Pereira da Silva, Victor Hugo; Ribeiro, Daniel Araki
Fonte: Informa Healthcare Publicador: Informa Healthcare
Tipo: Artigo de Revista Científica Formato: 567-574
ENG
Relevância na Pesquisa
37.13%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The Mimosa (Mimosa caesalpiniifolia) is a plant native from South America; it is used in the traditional medicine systems for treating bacterial, fungal, parasitic and inflammatory conditions. The aim of this study was to evaluate the antigenotoxic and antioxidant activities induced by mimosa (M. caesalpiniifolia) in multiple rodent organs subjected to intoxication with cadmium chloride. A total of 40 Wistar rats (8 weeks old, 250 g) were distributed into eight groups (n = 5), as follows: Control group (non-treated group, CTRL); Cadmium exposed group (Cd); cadmium exposure and treated with extract at 62.5 mg/kg/day; cadmium exposure and treated with extract at 125 mg/kg/day; cadmium exposure and treated with extract at 250 mg/kg/day; cadmium exposure and treated with ethyl acetate fraction at 62.5 mg/kg/day. For evaluating the toxicogenetic potential of mimosa, two groups were included in the study being treated with extract at 250 mg/kg/day and acetate fraction of mimosa at 62 mg/kg/day, only. Extract of mimosa at concentrations of 62.5 and 125mg decreased DNA damage in animals intoxicated with cadmium when compared to cadmium group. In a similar manner...

Estudos dos efeitos citotoxicos e de estresse oxidativo induzido pelo cloreto de cadmio associado ou não ao sulfato de zinco em celulas musculares esqueleticas e neoplasicas; Study of citotoxic effects and oxidative stress induced by cadmium chloride associated or not to zinc sulfate in skeletal muscle and neoplasic cells

Claudia Lumy Yano
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/11/2006 PT
Relevância na Pesquisa
37.1%
Metais pesados como o cádmio são considerados agentes tóxicos devido sua extensiva utilização nas indústrias e agropecuária e, como conseqüência, são amplamente dispersados no meio ambiente. No entanto, o cádmio tem sido foco, também, de inúmeras pesquisas relacionadas a exposição humana e suas conseqüências patológicas como o câncer. Estudos, claramente, caracterizam as relações de tumor de pulmão com a inalação do cádmio e mostram a possível participação deste metal tanto na iniciação quanto na progressão tumoral. Por outro lado, são raros os relatos da literatura envolvendo o mecanismo de ação do cádmio em tecido muscular, uma vez que já foi observado acúmulo desse metal em musculatura esquelética de animais. A administração do cloreto de cádmio, metal pesado designado como carcinogênico, em linhagem de células musculares esqueléticas C2C12 promoveu lesões consistentes com estresse oxidativo, observado pela diminuição da viabilidade celular, aumento da peroxidação de lipídios (conteúdo de malondialdeído) e conseqüente diminuição da enzima antioxidante glutationa transferase (GST). O estresse oxidativo, possivelmente, alterou a adesão celular e, conseqüentemente, houve retração dos miotúbulos...

The application of glyoxal-bis-(2-hydroxyanil) to the determination of trace amounts of cadmium by spectrofluorimetry

Dong,Yanjie; Gai,Ke
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2006 EN
Relevância na Pesquisa
37.08%
The fluorescent reaction of the reagent glyoxal-bis-(2-hydroxyanil) (GBHA) with cadmium was studied. Based on this chelation reaction, a sensitive, rapid, direct spectrofluorimetric method for the determination of trace cadmium with GBHA has been developed. The reaction conditions for the fluorescence system of cadmium with GBHA were established. The cadmium ion can form a stable chelate with GBHA, having a ratio of 1:3 in the 12.0 -13.0 pH range. The maximum excitation and emission wavelengths are 227.4 nm and 320.0 nm for the cadmium chelate, respectively. The fluorescence intensity of the cadmium chelate remains stable from 20 to 150 min. Under the optimal experimental conditions the fluorescence intensity is a linear function of concentration in the range 1.0-10.0 ng mL-1 of cadmium and the detection limit is 0.65 ng mL-1 of cadmium. Interferences of foreign ions were studied. The method has been successfully applied to the determination of cadmium in the sewage.

Post-partum testosterone administration partially reverses the effects of perinatal cadmium exposure on sexual behavior in rats

Couto-Moraes,Renato; Felício,Luciano Freitas; Oliveira,Claudio Alvarenga de; Bernardi,Maria Martha
Fonte: Pontificia Universidade Católica do Rio de Janeiro; Universidade de Brasília; Universidade de São Paulo Publicador: Pontificia Universidade Católica do Rio de Janeiro; Universidade de Brasília; Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 EN
Relevância na Pesquisa
37.1%
This study investigated the effects of perinatal cadmium exposure on sexual behavior, organ weight, and testosterone levels in adult rats. We examined whether immediate postpartum testosterone administration is able to reverse the toxic effects of the metal. Forty pregnant Wistar rats were divided into three groups: 1) control, 2) 10 mg kg-1 cadmium chloride per day, and 3) 20 mg kg-1 cadmium chloride per day. These dams were treated on gestational days 18 and 21 and from lactation 1 to 7. Immediately after birth, half of the offspring from the experimental and control groups received 50 μl (i.p.) of 0.2% testosterone. Male sexual behavior, histological analysis and weight of organs as well as serum testosterone levels were assessed. Results showed that both cadmium doses disrupted sexual behavior in male rats, and postnatal treatment with testosterone reversed the toxic effects of 10 mg kg-1 cadmium and attenuated the effects of 20 mg kg-1 cadmium. Body weight and absolute testis, epididymis, and seminal vesicle weight were decreased by the higher cadmium dose, and testosterone supplementation did not reverse these effects. Serum testosterone levels were unaffected by both cadmium doses. No histological changes were detected in all organs analyzed. Maternal cadmium exposure effects in sexual parameters of male rat offspring were explained by the altered masculinization of the hypothalamus. We suggest that cadmium damaged cerebral sexual differentiation by its actions as an endocrine disruptor and supported by the changes discretely observed from early life during sexual development to adult life...

Association between 24-Hour Urinary Cadmium and Pulmonary Function among Community-Exposed Men: The VA Normative Aging Study

Lampe, Brad J.; Robins, Thomas; Mukherjee, Bhramar; Hu, Howard; Park, Sung Kyun; Litonjua, Augusto Ampil; Amarasiriwardena, Chitra J.; Weisskopf, Marc G.; Sparrow, David
Fonte: National Institute of Environmental Health Sciences Publicador: National Institute of Environmental Health Sciences
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
37.08%
Background: High levels of cadmium exposure are known to cause emphysema in occupationally exposed workers, but little has been reported to date on the association between chronic environmental cadmium exposure and pulmonary function. Objective: In this study we examined the association between pulmonary function and cadmium body burden in a subcohort of the Normative Aging Study, a community-based study of aging. Methods: We examined 96 men who had cadmium measured in single 24-hr urinary specimens collected in 1994–1995 and who had one to three tests of pulmonary function between 1994 and 2002 (a total of 222 observations). We used mixed-effect models to predict pulmonary function based on individual 24-hr urinary cadmium output, adjusted for age, height, time elapsed from the baseline, and smoking status. We assessed effect modification by smoking status. Results: Among all subjects, a single log-unit increase in baseline urinary cadmium was inversely associated with forced expiratory volume in 1 sec (FEV1) percent predicted [β = −7.56%; 95% confidence interval (CI) −13.59% to −1.53%]; forced vital capacity (FVC) percent predicted (β = −2.70%; 95% CI −7.39% to 1.99%), and FEV1/FVC ratio (β = −4.13%; 95% CI −7.61% to −0.66%). In models including an interaction between urinary cadmium and smoking status...

Associations between cadmium exposure and neurocognitive test scores in a cross-sectional study of US adults

Ciesielski, Timothy; Bellinger, David C.; Schwartz, Joel David; Hauser, Russ B.; Wright, Robert O.
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
37.15%
Background: Low-level environmental cadmium exposure and neurotoxicity has not been well studied in adults. Our goal was to evaluate associations between neurocognitive exam scores and a biomarker of cumulative cadmium exposure among adults in the Third National Health and Nutrition Examination Survey (NHANES III). Methods: NHANES III is a nationally representative cross-sectional survey of the U.S. population conducted between 1988 and 1994. We analyzed data from a subset of participants, age 20–59, who participated in a computer-based neurocognitive evaluation. There were four outcome measures: the Simple Reaction Time Test (SRTT: visual motor speed), the Symbol Digit Substitution Test (SDST: attention/perception), the Serial Digit Learning Test (SDLT) trials-to-criterion, and the SDLT total-error-score (SDLT-tests: learning recall/short-term memory). We fit multivariable-adjusted models to estimate associations between urinary cadmium concentrations and test scores. Results: 5662 participants underwent neurocognitive screening, and 5572 (98%) of these had a urinary cadmium level available. Prior to multivariable-adjustment, higher urinary cadmium concentration was associated with worse performance in each of the 4 outcomes. After multivariable-adjustment most of these relationships were not significant...

Pollution of River Mahaweli and farmlands under irrigation by cadmium from agricultural inputs leading to a chronic renal failure epidemic among farmers in NCP, Sri Lanka

Bandara, J. M. R. S.; Wijewardena, H. V. P.; Bandara, Y. M. A. Y.; Jayasooriya, R. G. P. T.; Rajapaksha, Kolin Harinda
Fonte: Springer Science Publicador: Springer Science
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
Relevância na Pesquisa
37.13%
Chronic renal failure (CRF) associated with elevated dietary cadmium (Cd) among farming communities in the irrigated agricultural area under the River Mahaweli diversion scheme has reached a significantly higher level of 9,000 patients. Cadmium, derived from contaminated phosphate fertilizer, in irrigation water finds its way into reservoirs, and finally to food, causing chronic renal failure among consumers. Water samples of River Mahaweli and its tributaries in the upper catchment were analyzed to assess the total cadmium contamination of river water and the possible source of cadmium. Except a single tributary (Ulapane Stream, 3.9 lg Cd/l), all other tested tributaries carried more than 5 lg Cd/l, the maximum concentration level accepted to be safe in drinking water. Seven medium-sized streams carrying surface runoff from tea estates had 5.1–10 lg Cd/l. Twenty larger tributaries (Oya), where the catchment is under vegetable and home garden cultivation, carried 10.1–15 lg Cd/l. Nine other major tributaries had extremely high levels of Cd, reaching 20 lg Cd/l. Using geographic information system (GIS), the area in the catchment of each tributary was studied. The specific cropping system in each watershed was determined. The total cadmium loading from each crop area was estimated using the rates and types of phosphate fertilizer used by the respective farmers and the amount of cadmium contained in each type of fertilizer used. Eppawala rock phosphate (ERP)...

Cadmium removal by living cells of the marine microalgaTetraselmis suecica

Pérez Rama, Mónica; Abalde Alonso, Julio Ernesto; Herrero López, Concepción; Torres Vaamonde, José Enrique
Fonte: Universidade da Corunha Publicador: Universidade da Corunha
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.13%
[Abstract]Cadmium removal by living cells of the marine microalga Tetraselmis suecica was tested in cultures exposed to different cadmium concentrations (0.6, 3, 6, 15, 30 and 45 mg/l). The EC50 for growth was 7.9 mg Cd/l after six days of exposure. The cadmium removed was proportional to the concentration of this metal in the medium and it was dependent on the time of exposure; cultures with higher cadmium concentration removed a higher amount of this metal. In cultures exposed to 0.6 mg/l, T. suecica cells removed 98.1% of added cadmium with 0.392x10-6ug Cd/cell, whereas in cultures with 45 mg/l only 7.7% was removed with 16.052x10-6ug Cd/cell. The highest amount of cadmium removed per liter of culture was observed in cultures exposed to 6 mg/l, with 3.577 mg/l of cadmium. After six days of incubation, the higher proportion of cadmium was bioaccumulated intracellularly in all cultures except in 45 mg/l cultures, the percentage of intracellular cadmium being always more than 50%. The highest percentage of bioadsorbed cadmium (60.1%) was found in cells of cultures with the highest cadmium concentration (45 mg/l). Furthermore, a relation between intracellular cadmium and the concentration of sulfhydryl groups was observed.

Removal of cadmium ions by the marine diatom Phaeodactylum tricornutum Bohlin accumulation and long-term kinetics of uptake

Torres, Enrique; Cid Blanco, Ángeles; Herrero López, Concepción; Abalde Alonso, Julio Ernesto
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.16%
The marine diatom Phaeodactylum tricornutum Bohlin was exposed to different cadmium concentrations (1–100 mg l−1) for 4 days. The amount of cadmium removed was recorded, with particular attention paid to long-term uptake kinetics, and to the cellular location of cadmium. Cadmium accumulation occurred at all concentrations assayed. The EC50 of cadmium to P. tricornutum was 22·39 mg l−1 after 4 days of exposure. Cadmium uptake followed a saturation kinetic at cadmium concentrations ≥25 mg l−1. However, at lower cadmium concentrations, the uptake of this metal followed a linear trend for all days of culture. At cadmium concentrations in the medium lower than 25 mg l−1, P. tricornutum removed cadmium mainly within the cell. At higher cadmium concentrations, the amount of cadmium removed by adsorption to the cell surface was higher than intracellular cadmium, because of the toxic effects of cadmium on P. tricornutum cells. This toxicity reduced the cadmium accumulation within the cells.

Lung cancer risk associated with occupational exposure to nickel, chromium VI, and cadmium in two population-based case-control studies in Montreal.

Beveridge, Rachelle
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
37.12%
Cancer du poumon associé à l’exposition au nickel, au chrome VI et au cadmium dans le milieu de travail utilisant deux études populationnelles cas-témoins à Montréal. Au début des années 1990, le nickel, le chrome VI et le cadmium ont été classés en tant qu’agents cancérigènes de classe 1 par le CIRC (Centre International de Recherche sur le Cancer). Cependant, les résultats des études ayant permis la classification de ces métaux n’ont pas toujours été reproduits, et d’importantes questions demeurent quant aux effets de ces métaux à de faibles niveaux d’exposition. Un plus grand nombre de recherches empiriques est donc nécessaire afin de réaffirmer la cancérogénicité de ces agents, et d’identifier les circonstances dans lesquelles ils peuvent être néfastes. L'objectif de cette étude était d'explorer la relation entre l’exposition à un des métaux (soit le nickel, le chrome VI, ou le cadmium) et les risques subséquents de développer un cancer du poumon chez des travailleurs provenant de différents milieux de travail qui sont exposés à ces métaux à de différents degrés. Deux études cas-témoins de base populationnelle menées à Montréal ont fourni les données nécessaires pour examiner la cancérogénicité de ces métaux. La première étude était menée entre 1979 et 1986 chez des hommes âgés de 35 à 70 ans ayant un cancer dans l’un de 19 sites anatomiques de cancer sélectionnés. La seconde étude était menée entre 1996 et 2001 chez des hommes et des femmes âgés de 35 à 75 ans...

Otimização de metodologia analitica e avaliação da incidencia de cadmio e chumbo em leite humano e alimentos infantis.; Otimization of analytical methodology and evaluation of cadmium and lead incidence in human milk and baby foods.

Adriana Queiroz de Oliveira
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/07/2005 PT
Relevância na Pesquisa
37.15%
Elementos metálicos, como cádmio e chumbo, uma vez absorvidos pelo organismo, não são completamente eliminados, provocando alterações metabólicas com redução do tempo de vida e da capacidade de trabalho nos indivíduos expostos. Bebês e crianças pequenas constituem a parcela da população que inspira preocupação, do ponto de vista toxicológico, por apresentarem maior absorção que os adultos, em razão de seus organismos não estarem completamente desenvolvidos. Sabe-se que a maior fonte de exposição ao cádmio e ao chumbo, para indivíduos sem exposição ocupacional e não fumantes, é a dieta. Nos primeiros anos de vida, o ser humano possui uma dieta baseada principalmente no leite materno e em alimentos como formulações lácteas, formulações a base de soja, cereais e alimentos na forma de purê. Por esse motivo, levantamentos da contaminação por cádmio ou chumbo nestes alimentos destinados ao público infantil possuem grande importância. O presente trabalho visou obter dados sobre a incidência de cádmio e chumbo em leite humano em seis cidades do Estado de São Paulo (Bauru, Campinas, Presidente Prudente, Ribeirão Preto, São Paulo e Votuporanga), em alimentos infantis como formulações lácteas, formulações a base de soja...

The use of comparative genomics to investigate mechanisms of cadmium induced transcription

Tvermoes, Brooke Erin
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2009
Relevância na Pesquisa
37.22%

Cadmium is a human carcinogen and a persistent environmental pollutant of increasing concern. Yet, the exact molecular targets of cadmium toxicity and the molecular mechanisms by which cadmium influences gene expression have not been fully elucidated. Therefore, the characterization of cadmium-inducible genes will provide a better understanding of the underlying mechanism involved in sensing cadmium-stress and the subsequent signaling pathways important for cellular defense against cadmium toxicity. To this end, we characterized two cadmium-responsive genes of no known biological function from the nematode Caenorhabditis elegans (C. elegans), numr-1 and numr-2.

Expression analysis of numr-1 and numr-2 revealed the same temporal and spatial expression patterns of both genes in the absence and presence of metal treatment. In the absence of metal, constitutive expression of numr-1/-2 was developmentally regulated. When adult animals were exposed to metal, numr-1/-2 expression dramatically increased. We show that worms overexpressing numr-1/-2 were more resistant to metal stress and longer lived than control animals; whereas reducing numr-1/-2 activity resulted in increased sensitivity to metal exposure. Furthermore, in the absence of metal...

Effect of selenium on cadmium-induced oxidative stress and esterase activity in rat organs

Dzobo,Kevin; Naik,Yogeshkumar S.
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
37.1%
Metal toxicity is a threat mainly in the industrialised world where industry discharges many toxic metals into the environment. We investigated the effects of two metals - cadmium and selenium - on the cytosolic antioxidant enzymes and esterases in the liver, kidneys and testes of rats. Male Sprague-Dawley rats( N =28) were divided equally into four groups: control, cadmium, selenium and cadmium/selenium. Salts of the metals were administered intraperitoneally for 15 days. In the liver, cadmium treatment (1.67 mg/kg per day) resulted in a decrease in catalase activity and an increase superoxide dismutase (SOD) activity. Selenium treatment (0.23 mg/kg per day) resulted in increases in glutathione s-transferase, catalase and DT-diaphorase activities. Treatment with both cadmium and selenium resulted in an increase in glutathione peroxidase (GPx) activity. Esterase activities were significantly lower in the presence of cadmium. In the kidney, cadmium treatment caused a decrease in catalase, DT-diaphorase, and SOD activities and selenium supplementation reversed the cadmium-induced decrease in these enzyme activities. Selenium treatment increased catalase and SOD activities in the kidney. In the testis, cadmium treatment decreased GPx and SOD activities...