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1.
Haematologica ; 106(7): 1979-1987, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32586904

RESUMO

Pharmacological induction of fetal hemoglobin (HbF) expression is an effective therapeutic strategy for the management of beta-hemoglobinopathies such as sickle cell disease. DNA methyltransferase (DNMT) inhibitors 5-azacytidine (5-aza) and 5-aza-2'-deoxycytidine (decitabine) have been shown to induce fetal hemoglobin expression in both preclinical models and clinical studies, but are not currently approved for the management of hemoglobinopathies. We report here the discovery of a novel class of orally bioavailable DNMT1-selective inhibitors as exemplified by GSK3482364. This molecule potently inhibits the methyltransferase activity of DNMT1, but not DNMT family members DNMT3A or DNMT3B. In contrast with cytidine analog DNMT inhibitors, the DNMT1 inhibitory mechanism of GSK3482364 does not require DNA incorporation and is reversible. In cultured human erythroid progenitor cells (EPCs), GSK3482364 decreased overall DNA methylation resulting in de-repression of the gamma globin genes HBG1 and HBG2 and increased HbF expression. In a transgenic mouse model of sickle cell disease, orally administered GSK3482364 caused significant increases in both HbF levels and in the percentage HbF-expressing erythrocytes, with good overall tolerability. We conclude that in these preclinical models, selective, reversible inhibition of DNMT1 is sufficient for the induction of HbF, and is well-tolerated. We anticipate that GSK3482364 will be a useful tool molecule for the further study of selective DNMT1 inhibition both in vitro and in vivo.


Assuntos
Anemia Falciforme , Hemoglobina Fetal , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Animais , Azacitidina/farmacologia , Metilação de DNA , Hemoglobina Fetal/genética , Camundongos , gama-Globinas/genética
2.
AAPS PharmSciTech ; 18(3): 782-789, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27317571

RESUMO

The aim of this study is to investigate aerosol plume geometries of pressurised metered dose inhalers (pMDIs) using a high-speed laser image system with different actuator nozzle materials and designs. Actuators made from aluminium, PET and PTFE were manufactured with four different nozzle designs: cone, flat, curved cone and curved flat. Plume angles and spans generated using the designed actuator nozzles with four solution-based pMDI formulations were imaged using Oxford Lasers EnVision system and analysed using EnVision Patternate software. Reduced plume angles for all actuator materials and nozzle designs were observed with pMDI formulations containing drug with high co-solvent concentration (ethanol) due to the reduced vapour pressure. Significantly higher plume angles were observed with the PTFE flat nozzle across all formulations, which could be a result of the nozzle geometry and material's hydrophobicity. The plume geometry of pMDI aerosols can be influenced by the vapour pressure of the formulation, nozzle geometries and actuator material physiochemical properties.


Assuntos
Aerossóis/química , Química Farmacêutica/métodos , Interações Hidrofóbicas e Hidrofílicas , Lasers , Inaladores Dosimetrados , Tamanho da Partícula , Soluções Farmacêuticas/química , Solventes/química
3.
Pharm Res ; 32(4): 1237-48, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25270573

RESUMO

PURPOSE: To investigate the influence of different actuator nozzle designs on aerosol electrostatic charges and aerosol performances for pressurised metered dose inhalers (pMDIs). METHODS: Four actuator nozzle designs (flat, curved flat, cone and curved cone) were manufactured using insulating thermoplastics (PET and PTFE) and conducting metal (aluminium) materials. Aerosol electrostatic profiles of solution pMDI formulations containing propellant HFA 134a with different ethanol concentration and/or model drug beclomethasone dipropionate (BDP) were studied using a modified electrical low-pressure impactor (ELPI) for all actuator designs and materials. The mass of the deposited drug was analysed using high performance liquid chromatography (HPLC). RESULTS: Both curved nozzle designs for insulating PET and PTFE actuators significantly influenced aerosol electrostatics and aerosol performance compared with conducting aluminium actuator, where reversed charge polarity and higher throat deposition were observed with pMDI formulation containing BDP. Results are likely due to the changes in plume geometry caused by the curved edge nozzle designs and the bipolar charging nature of insulating materials. CONCLUSIONS: This study demonstrated that actuator nozzle designs could significantly influence the electrostatic charges profiles and aerosol drug deposition pattern of pMDI aerosols, especially when using insulating thermoplastic materials where bipolar charging is more dominant.


Assuntos
Alumínio/química , Inaladores Dosimetrados , Polietilenotereftalatos/química , Politetrafluoretileno/química , Eletricidade Estática , Propelentes de Aerossol/química , Aerossóis , Beclometasona/administração & dosagem , Desenho de Equipamento , Hidrocarbonetos Fluorados/química
4.
Pharm Res ; 32(9): 2928-36, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25788449

RESUMO

PURPOSE: This study investigated the effect of different active pharmaceutical ingredients (API) on aerosol electrostatic charges and aerosol performances for pressurized metered dose inhalers (pMDIs), using both insulating and conducting actuators. METHODS: Five solution-based pMDIs containing different API ingredients including: beclomethasone dipropionate (BDP), budesonide (BUD), flunisolide (FS), salbutamol base (SB) and ipratropium bromide (IPBr) were prepared using pressure filling technique. Actuator blocks made from nylon, polytetrafluoroethylene (PTFE) and aluminium were manufactured with 0.3 mm nominal orifice diameter and cone nozzle shape. Aerosol electrostatics for each pMDI formulation and actuator were evaluated using the electrical low-pressure impactor (ELPI) and drug depositions were analysed using high performance liquid chromatography (HPLC). RESULTS: All three actuator materials showed the same net charge trend across the five active drug ingredients, with BDP, BUD and FS showing positive net charges for both nylon and PTFE actuators, respectively. While SB and IPBr had significantly negative net charges across the three different actuators, which correlates to the ionic functional groups present on the drug molecule structures. CONCLUSIONS: The API present in a pMDI has a dominant effect on the electrostatic properties of the formulation, overcoming the charge effect arising from the actuator materials. Results have shown that the electrostatic charges for a solution-based pMDI could be related to the interactions of the chemical ingredients and change in the work function for the overall formulation.


Assuntos
Aerossóis/química , Preparações Farmacêuticas/química , Albuterol/química , Beclometasona/química , Budesonida/química , Química Farmacêutica/métodos , Fluocinolona Acetonida/análogos & derivados , Fluocinolona Acetonida/química , Ipratrópio/química , Inaladores Dosimetrados , Tamanho da Partícula , Pressão , Soluções/química , Eletricidade Estática
5.
Pharm Res ; 31(5): 1325-37, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24297072

RESUMO

PURPOSE: To investigate the influence of different actuator materials and nozzle designs on the electrostatic charge properties of a series of solution metered dose inhaler (pMDI) aerosols. METHODS: Actuators were manufactured with flat and cone nozzle designs using five different materials from the triboelectric series (Nylon, Polyethylene terephthalate, Polyethylene-High density, Polypropylene copolymer and Polytetrafluoroethylene). The electrostatic charge profiles of pMDI containing beclomethasone dipropionate (BDP) as model drug in HFA-134a propellant, with different concentrations of ethanol were studied. Electrostatic measurements were taken using a modified electrical low-pressure impactor (ELPI) and the deposited drug mass assayed chemically using HPLC. RESULTS: The charge profiles of HFA 134a alone have shown strong electronegativity with all actuator materials and nozzle designs, at an average of -1531.34 pC ± 377.34. The presence of co-solvent ethanol significantly reduced the negative charge magnitude. BDP reduced the suppressing effect of ethanol on the negative charging of the propellant. For all tested formulations, the flat nozzle design showed no significant differences in net charge between different actuator materials, whereas the charge profiles of cone designs followed the triboelectric series. CONCLUSION: The electrostatic charging profiles from a solution pMDI containing BDP and ethanol can be significantly influenced by the actuator material, nozzle design and formulation components. Ethanol concentration appears to have the most significant impact. Furthermore, BDP interactions with ethanol and HFA have an influence on the electrostatic charge of aerosols. By choosing different combinations of actuator materials and orifice design, the fine particle fractions of formulations can be altered.


Assuntos
Desenho de Equipamento , Inaladores Dosimetrados , Eletricidade Estática , Aerossóis , Cromatografia Líquida de Alta Pressão
6.
Am J Physiol Lung Cell Mol Physiol ; 304(5): L312-23, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23292810

RESUMO

The role of T cells in chronic obstructive pulmonary disease (COPD) is not well understood. We have previously demonstrated that chronic cigarette smoke exposure can lead to the accumulation of CD4(+) and CD8(+) T cells in the alveolar airspaces in a mouse model of COPD, implicating these cells in disease pathogenesis. However, whether specific inhibition of T cell responses represents a therapeutic strategy has not been fully investigated. In this study inhibition of T cell responses through specific depleting antibodies, or the T cell immunosuppressant drug cyclosporin A, prevented airspace enlargement and neutrophil infiltration in a mouse model of chronic cigarette smoke exposure. Furthermore, individual inhibition of either CD4(+) T helper or CD8(+) T cytotoxic cells prevented airspace enlargement to a similar degree, implicating both T cell subsets as critical mediators of the adaptive immune response induced by cigarette smoke exposure. Importantly, T cell depletion resulted in significantly decreased levels of the Th17-associated cytokine IL-17A, and of caspase 3 and caspase 7 gene expression and activity, induced by cigarette smoke exposure. Finally, inhibition of T cell responses in a therapeutic manner also inhibited cigarette smoke-induced airspace enlargement, IL-17A expression, and neutrophil influx in mice. Together these data demonstrate for the first time that therapeutic inhibition of T cell responses may be efficacious in the treatment of COPD. Given that broad immunosuppression may be undesirable in COPD patients, this study provides proof-of-concept for more targeted approaches to inhibiting the role of T cells in emphysema development.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Alvéolos Pulmonares/patologia , Doença Pulmonar Obstrutiva Crônica/imunologia , Fumar , Animais , Caspase 3/sangue , Caspase 7/biossíntese , Caspase 7/genética , Ciclosporina , Modelos Animais de Doenças , Feminino , Expressão Gênica , Terapia de Imunossupressão , Interleucina-17/sangue , Medidas de Volume Pulmonar , Ativação Linfocitária , Depleção Linfocítica , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos/imunologia , Alvéolos Pulmonares/imunologia , Doença Pulmonar Obstrutiva Crônica/patologia , Poluição por Fumaça de Tabaco
7.
Prostaglandins Other Lipid Mediat ; 104-105: 25-31, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23434473

RESUMO

Soluble epoxide hydrolase (sEH, EPHX2) metabolizes eicosanoid epoxides, including epoxyeicosatrienoic acids (EETs) to the corresponding dihydroxyeicosatrienoic acids (DHETs), and leukotoxin (LTX) to leukotoxin diol (LTX diol). EETs, endothelium-derived hyperpolarizing factors, exhibit potentially beneficial properties, including anti-inflammatory effects and vasodilation. A novel, potent, selective inhibitor of recombinant human, rat and mouse sEH, GSK2256294A, exhibited potent cell-based activity, a concentration-dependent inhibition of the conversion of 14,15-EET to 14,15-DHET in human, rat and mouse whole blood in vitro, and a dose-dependent increase in the LTX/LTX diol ratio in rat plasma following oral administration. Mice receiving 10 days of cigarette smoke exposure concomitant with oral administration of GSK2256294A exhibited significant, dose-dependent reductions in pulmonary leukocytes and keratinocyte chemoattractant (KC, CXCL1) levels. Mice receiving oral administration of GSK2256294A following 10 days of cigarette smoke exposure exhibited significant reductions in pulmonary leukocytes compared to vehicle-treated mice. These data indicate that GSK2256294A attenuates cigarette smoke-induced inflammation by both inhibiting its initiation and/or maintenance and promoting its resolution. Collectively, these data indicate that GSK2256294A would be an appropriate agent to evaluate the role of sEH in clinical studies, for example in diseases where cigarette smoke is a risk factor, such as chronic obstructive pulmonary disease (COPD) and cardiovascular disease.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Cicloexilaminas/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Leucócitos/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Triazinas/farmacologia , Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Ácido 8,11,14-Eicosatrienoico/metabolismo , Administração Oral , Adulto , Animais , Quimiocina CXCL1/biossíntese , Relação Dose-Resposta a Droga , Epóxido Hidrolases/metabolismo , Exotoxinas/metabolismo , Feminino , Humanos , Inflamação/enzimologia , Inflamação/etiologia , Inflamação/patologia , Inflamação/prevenção & controle , Contagem de Leucócitos , Leucócitos/metabolismo , Leucócitos/patologia , Pulmão/enzimologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ácidos Esteáricos/metabolismo , Poluição por Fumaça de Tabaco/efeitos adversos
8.
Environ Monit Assess ; 185(1): 755-75, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22392619

RESUMO

Data from toxicity tests of the pore water extracted from Puget Sound sediments were compiled from surveys conducted from 1997 to 2009. Tests were performed on 664 samples collected throughout all of the eight monitoring regions in the Sound, an area encompassing 2,294.1 km(2). Tests were performed with the gametes of the Pacific purple sea urchin, Strongylocentrotus purpuratus, to measure percent fertilization success as an indicator of relative sediment quality. Data were evaluated to determine the incidence, degree of response, geographic patterns, spatial extent, and temporal changes in toxicity. This is the first survey of this kind and magnitude in Puget Sound. In the initial round of surveys of the eight regions, 40 of 381 samples were toxic for an incidence of 10.5 %. Stations classified as toxic represented an estimated total of 107.1 km(2), equivalent to 4.7 % of the total area. Percent sea urchin fertilization ranged from >100 % of the nontoxic, negative controls to 0 %. Toxicity was most prevalent and pervasive in the industrialized harbors and lowest in the deep basins. Conditions were intermediate in deep-water passages, urban bays, and rural bays. A second round of testing in four regions and three selected urban bays was completed 5-10 years following the first round. The incidence and spatial extent of toxicity decreased in two of the regions and two of the bays and increased in the other two regions and the third bay; however, only the latter change was statistically significant. Both the incidence and spatial extent of toxicity were lower in the Sound than in most other US estuaries and marine bays.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Poluentes Químicos da Água/toxicidade , Análise Espaço-Temporal , Washington , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos
9.
Hand (N Y) ; : 15589447221131849, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36341587

RESUMO

PURPOSE: To determine how time to surgical debridement and fixation affects infection and complication rate in type I open distal radius fractures by comparing patients treated within 24 hours with those treated >24 hours post-injury. METHODS: A retrospective review identified 62 patients who sustained a type I open distal radius fracture that was treated surgically. Patients were stratified into groups based on time to surgical intervention. An additional analysis was performed on patients with an isolated type I open distal radius fracture treated as an inpatient or outpatient. The primary outcome measure was infection rate. Secondary outcome measures were complications, reoperations, and readmissions. RESULTS: Thirty-eight patients underwent surgery ≤24 hours post-injury at an average of 14 hours. Twenty-four patients underwent surgery >24 hours post-injury at an average of 72 hours. There were a total of 9 complications in 8 patients (14.5%). The overall infection rate was 1.6%, with only 1 deep infection occurring in the group treated ≤24 hours post-injury. There were 7 reoperations (11.3%) and 1 readmission (1.6%). No differences were found between groups in any outcome measure. In the 27 patients with an isolated fracture, there were no differences in any outcome measure when treated as an inpatient or outpatient. CONCLUSIONS: We suggest that type I open distal radius fractures could be safely treated surgically >24 hours post-injury without increased risk of infection.

10.
Mol Microbiol ; 69(5): 1165-79, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18627467

RESUMO

The Escherichia coli SOS response to DNA damage is modulated by the RecA protein, a recombinase that forms an extended filament on single-stranded DNA and hydrolyzes ATP. The RecA K72R (recA2201) mutation eliminates the ATPase activity of RecA protein. The mutation also limits the capacity of RecA to form long filaments in the presence of ATP. Strains with this mutation do not undergo SOS induction in vivo. We have combined the K72R variant of RecA with another mutation, RecA E38K (recA730). In vitro, the double mutant RecA E38K/K72R (recA730,2201) mimics the K72R mutant protein in that it has no ATPase activity. The double mutant protein will form long extended filaments on ssDNA and facilitate LexA cleavage almost as well as wild-type, and do so in the presence of ATP. Unlike recA K72R, the recA E38K/K72R double mutant promotes SOS induction in vivo after UV treatment. Thus, SOS induction does not require ATP hydrolysis by the RecA protein, but does require formation of extended RecA filaments. The RecA E38K/K72R protein represents an improved reagent for studies of the function of ATP hydrolysis by RecA in vivo and in vitro.


Assuntos
Trifosfato de Adenosina/metabolismo , Proteínas de Escherichia coli/química , Escherichia coli/química , Escherichia coli/enzimologia , Recombinases Rec A/química , Resposta SOS em Genética , Substituição de Aminoácidos , Proteínas de Bactérias/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/ultraestrutura , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/ultraestrutura , Escherichia coli/genética , Escherichia coli/efeitos da radiação , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Hidrólise , Recombinases Rec A/genética , Recombinases Rec A/metabolismo , Recombinases Rec A/ultraestrutura , Resposta SOS em Genética/efeitos da radiação , Serina Endopeptidases/metabolismo , Raios Ultravioleta
11.
Immunol Lett ; 121(1): 13-21, 2008 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-18706444

RESUMO

Recently, patients with tobacco smoke induced emphysema have been shown to exhibit classical signs of T cell mediated autoimmunity characterized by autoantibody production and Th1 type responses. As the recently described Th17 type subset has been found to play a role in the pathogenesis of a number of autoimmune diseases previously considered to be Th1 driven, we sought to examine whether a Th17 type response was associated with airspace enlargement in a murine model of emphysema. Six to eight months exposure of mice to inhalation of mainstream cigarette smoke led to progressive airspace enlargement as defined by morphometric analysis. Flow cytometric analysis of the bronchoalveolar lavage (BAL) from these mice demonstrated a significant increase in the overall number of both CD4+ and CD8+ T cells present. These cells were subsequently examined for skewing towards a Th1, Th2 or Th17 phenotype by intracellular cytokine analysis. Distinct populations of BAL CD4+ T cells were found to express IFN-gamma or IL-17 demonstrating the presence of both a Th1 and Th17 type response. No expression of the Th2 associated cytokine IL-4 was detected. Further analysis of this Th17 subset demonstrated that the majority of cells with this effector phenotype express the chemokine receptor CCR6. Together these data identify a novel T cell subset associated with pulmonary inflammation as a result of cigarette smoke exposure. Given the reported roles of CCR6 and IL-17 in promoting pulmonary inflammation, this subset may play an important role in the pathogenesis of cigarette smoke induced autoimmunity.


Assuntos
Interleucina-17/imunologia , Pulmão/imunologia , Pneumonia/imunologia , Enfisema Pulmonar/imunologia , Fumar/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Autoimunidade , Líquido da Lavagem Broncoalveolar/imunologia , Modelos Animais de Doenças , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-17/metabolismo , Interleucina-4/imunologia , Interleucina-4/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Pneumonia/metabolismo , Pneumonia/patologia , Enfisema Pulmonar/metabolismo , Enfisema Pulmonar/patologia , Receptores CCR6/imunologia , Receptores CCR6/metabolismo , Fumar/patologia , Subpopulações de Linfócitos T/metabolismo
12.
PLoS One ; 12(4): e0176075, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28448604

RESUMO

The purpose of this work was to use various molecular imaging techniques to non-invasively assess GSK2849330 (anti HER3 ADCC and CDC enhanced 'AccretaMab' monoclonal antibody) pharmacokinetics and pharmacodynamics in human xenograft tumor-bearing mice. Immuno-PET biodistribution imaging of radiolabeled 89Zr-GSK2849330 was assessed in mice with HER3 negative (MIA-PaCa-2) and positive (CHL-1) human xenograft tumors. Dose dependency of GSK2849330 disposition was assessed using varying doses of unlabeled GSK2849330 co-injected with 89Zr-GSK2849330. In-vivo NIRF optical imaging and ex-vivo confocal microscopy were used to assess the biodistribution of GSK2849330 and the HER3 receptor occupancy in HER3 positive xenograft tumors (BxPC3, and CHL-1). Ferumoxytol (USPIO) contrast-enhanced MRI was used to investigate the effects of GSK2849330 on tumor macrophage content in CHL-1 xenograft bearing mice. Immuno-PET imaging was used to monitor the whole body drug biodistribution and CHL-1 xenograft tumor uptake up to 144 hours post injection of 89Zr-GSK2849330. Both hepatic and tumor uptake were dose dependent and saturable. The optical imaging data in the BxPC3 xenograft tumor confirmed the tumor dose response finding in the Immuno-PET study. Confocal microscopy showed a distinguished cytoplasmic punctate staining pattern within individual CHL-1 cells. GSK2849330 inhibited tumor growth and this was associated with a significant decrease in MRI signal to noise ratio after USPIO injection and with a significant increase in tumor macrophages as confirmed by a quantitative immunohistochemistry analysis. By providing both dose response and time course data from both 89Zr and fluorescently labeled GSK2849330, complementary imaging studies were used to characterize GSK2849330 biodistribution and tumor uptake in vivo. Ferumoxytol-enhanced MRI was used to monitor aspects of the immune system response to GSK2849330. Together these approaches potentially provide clinically translatable, non-invasive techniques to support dose optimization, and assess immune activation and anti-tumor responses.


Assuntos
Anticorpos Monoclonais Humanizados/farmacocinética , Anticorpos Monoclonais/farmacocinética , Macrófagos/imunologia , Compostos Radiofarmacêuticos/farmacocinética , Receptor ErbB-3/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/química , Anticorpos Monoclonais Humanizados/uso terapêutico , Linhagem Celular Tumoral , Feminino , Óxido Ferroso-Férrico/química , Humanos , Imuno-Histoquímica , Marcação por Isótopo , Macrófagos/citologia , Macrófagos/patologia , Camundongos , Camundongos Nus , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Radioisótopos , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/uso terapêutico , Receptor ErbB-3/metabolismo , Distribuição Tecidual , Transplante Heterólogo , Zircônio/química
13.
Environ Int ; 32(4): 455-65, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16337000

RESUMO

An internally consistent dataset comprising 103 surficial estuarine sediment samples were collected from Sydney Harbour, Australia and locations south of Sydney. This paper describes the chemical characteristics of the dataset and evaluates its suitability for use in evaluating biological effects-based sediment quality guidelines (SQGs). The sediments contained mixtures of chemicals, the most prevalent chemical classes being metals and polycyclic aromatic hydrocarbons, whereas sediments from coastal lakes/estuaries south of Sydney had low concentrations of contaminants. Maximum concentrations of the prevalent contaminants zinc, lead, copper and pyrene were 11,300, 1,420, 1,060 mg kg(-1) and 23,300 microg kg(-1), respectively. For the majority of samples, concentrations of individual chemicals exceeded most effects-based SQGs that have been adopted for use in Australia, implying occasional or frequent adverse biological effects are expected. Comparing mixtures of contaminants to ranges in numbers of SQGs exceeded and mean SQG quotients showed that most samples (57% to 68%) had contamination characteristics associated with moderate probabilities (30% to 52%) of acute toxicity, based on North American data. A smaller proportion of samples (15% to 17%) had contamination characteristics associated with high probabilities (74% to 85%) of toxicity. The wide range of chemicals and concentrations, associated with low, medium and high probabilities of toxicity, indicated that the dataset was suitable for future use in evaluating predictive abilities of SQGs. This is relevant, given the recent introduction of North American-derived SQGs for Australia.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/análise , Metais Pesados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Austrália , Sedimentos Geológicos/química , Guias como Assunto , Metais Pesados/toxicidade , Praguicidas/toxicidade , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Medição de Risco , Poluentes Químicos da Água/toxicidade
14.
Environ Int ; 32(5): 638-49, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16580069

RESUMO

Matching chemical and toxicological data of surficial sediments from Sydney Harbour, Australia, and vicinity, were collected to evaluate predictive abilities of Effects Range-Low (ERL), Effects Range-Median (ERM) and other sediment quality guidelines (SQGs). Samples (n=103) containing a wide range of chemicals and concentrations were subjected to a battery of 4-6 toxicity tests. ERLs and functionally equivalent low-range SQGs were highly predictive of non-toxicity when not exceeded, as incidences of toxicity were 0-8%. ERMs and other mid-range SQGs were predictive of toxicity in combined test data with > or = 80% of toxic samples with one or more SQG exceeded. Predictive abilities of mid-range SQGs were low for amphipod survival tests (generally < 20% toxic samples), but the incidence of toxicity increased with increasing numbers of SQGs exceeded and increasing mean SQG quotients. Predictive abilities of SQGs generally matched their narrative intent when outcomes of multiple toxicity tests were considered, and were consistent with North American data. Functionally equivalent SQGs gave comparable results (except where developed for single chemical classes), indicating that predictive abilities were primarily influenced by sensitivities of test species and/or the bioavailability of contaminants.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/análise , Guias como Assunto , Testes de Toxicidade , Poluentes Químicos da Água/análise , Austrália , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Testes de Toxicidade/métodos , Testes de Toxicidade/normas
15.
Environ Toxicol Chem ; 25(10): 2576-83, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17022396

RESUMO

Recent studies by researchers at the U.S. Environmental Protection Agency and U.S. Geological Survey have evaluated the toxicity of Cr in freshwater and marine sediments, primarily during laboratory studies in which clean sediments were spiked with Cr. Results of those studies showed that Cr is relatively insoluble and nontoxic when present in the trivalent form, Cr(III), rather than in the more soluble and more toxic hexavalent form, Cr(VI). The studies concluded that Cr toxicity should be low in sediments with measurable concentrations of acid-volatile sulfide (AVS), because AVS is formed only in anoxic sediments and Cr(VI) is thermodynamically unstable under such conditions. The present study evaluates the toxicity and bioavailability of Cr in sediments associated with chromite ore processing residue (COPR). Ten stations were sampled in the Hackensack River (NJ, USA) to represent a wide range of total Cr concentrations (199-3,970 mg/kg) with minimal interference from potentially toxic, co-occurring chemicals. Sediment toxicity was evaluated using two amphipod tests: The 10-d Ampelisca abdita test (survival as endpoint), and the 28-d Leptocheirus plumulosus test (survival and biomass as endpoints). Measurable concentrations of AVS were present at eight stations, and nearly all Cr was present as Cr(III). In addition, results of electron-microprobe analyses showed that most Cr was associated with phases in which Cr has limited bioavailability (i.e., chromite and iron oxide). Sediment toxicity showed no correlation with concentrations of total Cr, and the maximum no-effect concentration for total Cr was estimated as 1,310 mg/ kg. These results indicate that Cr can be present in sediments associated with COPR at highly elevated concentrations without causing sediment toxicity.


Assuntos
Cromo/toxicidade , Sedimentos Geológicos/química , Disponibilidade Biológica , Cromo/farmacocinética , Microanálise por Sonda Eletrônica
16.
Environ Toxicol Chem ; 24(10): 2545-52, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16268156

RESUMO

Laboratory survival tests were conducted with an indigenous infaunal amphipod, Corophium colo, on 103 sediment samples from Sydney Harbor (NSW, Australia) and vicinity, containing a wide range of chemicals and concentrations. The present study describes the sensitivity of C. colo to the sediments and compares the results to data for North American amphipods (Rhepoxynius abronius and Ampelisca abdita) previously used to establish and validate sediment-quality guidelines (SQGs). The incidence of toxicity increased with increasing contamination, as indicated by increasing numbers of SQGs exceeded and increasing mean SQG quotients. The incidence of highly toxic results (p < 0.05 and mean amphipod survival of < 80% that of controls) for highly contaminated samples was approximately half (28-40%) that of a large U.S. database (74%). The incidence of highly toxic responses for samples with intermediate levels of contamination also was lower in the present study (5-13%) compared to the results in large U.S. studies (approximately 30-50%). Corophium colo reburial tests showed greater sensitivity compared to survival tests, with a maximum incidence of statistically significant responses in moderately contaminated sediments of 70%. The present study showed that adult Corophium organisms are suitable for testing lethal responses in highly contaminated sediments (i.e., with mean effects range-median quotients of >1.5). Reburial results provide additional sensitivity.


Assuntos
Anfípodes , Sedimentos Geológicos/química , Poluentes da Água/toxicidade , Animais , Monitoramento Ambiental , New South Wales , Valores de Referência , Sobrevida , Testes de Toxicidade
17.
Artigo em Inglês | MEDLINE | ID: mdl-24730831

RESUMO

An experimental investigation into the interaction that occurs between an impacting water droplet and a granular bed of loose graded sand has been carried out. High-speed imaging, three-dimensional time-resolved particle tracking, and photogrammetric surface profiling have been used to examine individual impact events. The focus of the study is the quantification and trajectory analysis of the particles ejected from the sand bed, along with measurement of the change in bed morphology. The results from the experiments have detailed two distinct mechanisms of particle ejection: the ejection of water-encapsulated particles from the edge of the wetted region and the ejection of dry sand from the periphery of the impact crater. That the process occurs by these two distinct mechanisms has hitherto been unobserved. Presented in the paper are distributions of the particle ejection velocities, angles, and transport distances for both mechanisms. The ejected water-encapsulated particles, which are few in number, are characterized by low ejection angles and high ejection velocities, leading to large transport distances; the ejected dry particles, which are much greater in number, are characterized by high ejection angles and low velocities, leading to lower transport distances. From the particle ejection data, the momentum of the individual ballistic sand particles has been calculated; it was found that only 2% of the water-droplet momentum at impact is transferred to the ballistic sand particles. In addition to the particle tracking, surface profiling of the granular bed postimpact has provided detailed information on its morphology; these data have demonstrated the consistent nature of the craters produced by the impact and suggest that particle agglomerations released from their edges make up about twice the number of particles involved in ballistic ejection. It is estimated that, overall, about 4% of the water-droplet momentum is taken up in particle movement.

18.
Integr Environ Assess Manag ; 9(1): 31-49, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22488838

RESUMO

The Washington State Department of Ecology annually conducts sediment quality monitoring in Puget Sound as a component of the Puget Sound Ecosystem Monitoring Program. Sediment samples are analyzed to determine the concentrations of about 170 chemical and physical variables. A Sediment Chemistry Index (SCI) was derived using the State of Washington Sediment Management Standards to account for the presence and concentrations of mixtures of toxicants. Mean Sediment Quality Standard quotients (mSQSq) were calculated as the basis for the SCI and compared to the incidence and degree of toxicity in laboratory tests and to metrics of the diversity and abundance of resident benthic assemblages in a database consisting of as many as 664 samples. These data were evaluated with co-occurrence analyses to identify "cut points" (i.e., thresholds) in the index below which the frequency and magnitude of biological effects were relatively low and above which they occurred with increasing frequency or magnitude. Iterative trials of different sets of cut points established the final cut points in mSQSq of 0.1, 0.3, and 0.5. They defined 4 ranges in chemical exposure: Minimum (<0.1), Low (0.1- < 0.3), Moderate (0.3- < 0.5), and Maximum (≥0.5). Across these 4 exposure ranges both the incidence and magnitude of toxicity in some laboratory tests increased, the abundance of most stress-sensitive benthic taxa decreased, and the abundance of most stress-tolerant taxa increased. The mSQSq cut point of 0.1 appears to be the target value for protection of benthic resources, the value below which the probability and magnitude of adverse effects either in the laboratory or the field are the lowest. The mSQSq values are rescaled from 0 to 100 to form the SCI, used by the Puget Sound Partnership and environmental managers as a Dashboard Indicator, with biologically relevant targets selected to monitor ecosystem recovery.


Assuntos
Baías/química , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Sedimentos Geológicos/química , Ecotoxicologia/normas , Monitoramento Ambiental/normas , Poluentes Ambientais/química , Poluentes Ambientais/toxicidade , Laboratórios , Padrões de Referência , Washington
19.
Environ Toxicol Chem ; 32(8): 1701-10, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23843318

RESUMO

Concentrations of 119 pharmaceuticals and personal care products (PPCPs) and 13 perfluoroalkyl substances (PFASs) in marine sediments measured throughout Puget Sound (n = 10) and Bellingham Bay (n = 30), Washington, USA, are reported. These data are among the first measurements of PPCPs and PFASs in marine sediments from the Pacific Northwest and provide a comparison to previous measurements of these chemicals in influent, effluent, and biosolids from municipal wastewater treatment plants throughout the region. The concentrations of both PPCPs and PFASs in sediments from Puget Sound and Bellingham Bay ranged from very low to non-detectable for most compounds. Only 14 of the 119 PPCPs and 3 of 13 PFASs were quantifiable in sediments. Diphenhydramine (an antihistamine) was most frequently detected (87.5% of samples), with a maximum concentration of 4.81 ng/g dry weight and an estimated mean detected concentration of 1.68 ng/g. Triclocarban (an antibacterial) was detected in 35.0% of the samples, with a maximum concentration of 16.6 ng/g dry weight. Perfluoroalkyl substances were detected in 2.5% of analyses. Perfluorobutanoate, perfluorooctane sulfonate, and perfluorooctane sulfonamide were detected in 7, 5, and 1 sample(s) each, respectively, with the highest concentrations observed for perfluorooctane sulfonate (1.5 ng/g). Detected concentrations were often highest within the industrial harbor in Bellingham Bay and near the cities of Seattle and Bremerton. Environ Toxicol Chem 2013;32:1701-1710. © 2013 SETAC.


Assuntos
Cosméticos/análise , Monitoramento Ambiental , Fluorocarbonos/análise , Sedimentos Geológicos/química , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , Ácidos Alcanossulfônicos/análise , Carbanilidas/análise , Cidades , Washington , Poluição Química da Água/estatística & dados numéricos
20.
Environ Monit Assess ; 139(1-3): 257-75, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17588158

RESUMO

The lower Passaic River in northern New Jersey (USA) has been heavily industrialized since the mid-nineteenth century and its shoreline and aquatic habitats degraded or destroyed. Similar to other urban systems, Passaic River sediments, both surface and buried, historically have contained elevated levels of numerous contaminants that may pose risks to ecological receptors and humans. Sediments from 15 stations in the lower Passaic River and 3 reference stations in the Mullica River in southern New Jersey were sampled in 1999 and characterized for chemical contamination, toxicity, and impairment of the benthic community. The objective of this study was to determine the incidence, degree, and nature of degraded surficial sediments in the area to support subsequent plans for restoration of the system. Results demonstrated that Passaic River sediments had concentrations of many organic and inorganic contaminants at levels significantly greater than the reference area and effect-based guidelines. Sediments were toxic to marine amphipods at 11 stations and the benthic assemblages were impaired relative to the reference area at all stations. The weight-of-evidence of this sediment quality triad (SQT) assessment indicates that impacts from multiple contaminants are occurring throughout the lower Passaic River and, that these impacts must be evaluated further and addressed as part of ongoing restoration initiatives for the river.


Assuntos
Água Doce/química , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , New England , Poluentes Químicos da Água/toxicidade
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