Investigação e avaliação da toxicidade aguda dos agrotóxicos mais utilizados no cinturão verde da Grande Natal (RN, Brasil) para o peixe-zebra (Danio rerio Hamilton Buchanan, 1822, Teleostei, Cyprinidae

The objectives of this research were to investigate the agrotoxic most used in the Gramorezinho region in the green belt of Natal, and to evaluate the acute toxicity of these, based on the LC50-48h values estimated in tests for Danio rerio, internationally used as test organism. The acute toxicity tests were performed under laboratory conditions, according to standardized methods (ABNT/NBR/15088/04) for this species. The LC50-48h estimated to Tamaron BR was 352.89 mg.L-1, which characterizes that as practically non-toxic, according to toxicological classes cited by Zucker. For Decis 25EC, the LC50-48h estimated was 0.0004156 mg.L-1 (4.156 X 10-4 mg.L-1), which classifies it as highly toxic to this species

Investigação e avaliação da toxicidade aguda dos agrotóxicos mais utilizados no cinturão verde da Grande Natal (RN, Brasil) para o peixe-zebra (Danio rerio Hamilton Buchanan, 1822, Teleostei, Cyprinidae

The objectives of this research were to investigate the agrotoxic most used in the Gramorezinho region in the green belt of Natal, and to evaluate the acute toxicity of these, based on the LC50-48h values estimated in tests for Danio rerio, internationally used as test organism. The acute toxicity tests were performed under laboratory conditions, according to standardized methods (ABNT/NBR/15088/04) for this species. The LC50-48h estimated to Tamaron BR was 352.89 mg.L-1, which characterizes that as practically non-toxic, according to toxicological classes cited by Zucker. For Decis 25EC, the LC50-48h estimated was 0.0004156 mg.L-1 (4.156 X 10-4 mg.L-1), which classifies it as highly toxic to this species

Investigação e avaliação da toxicidade aguda dos agrotóxicos mais utilizados no cinturão verde da Grande Natal (RN, Brasil) para o peixe-zebra (Danio rerio Hamilton Buchanan, 1822, Teleostei, Cyprinidae

The objectives of this research were to investigate the agrotoxic most used in the Gramorezinho region in the green belt of Natal, and to evaluate the acute toxicity of these, based on the LC50-48h values estimated in tests for Danio rerio, internationally used as test organism. The acute toxicity tests were performed under laboratory conditions, according to standardized methods (ABNT/NBR/15088/04) for this species. The LC50-48h estimated to Tamaron BR was 352.89 mg.L-1, which characterizes that as practically non-toxic, according to toxicological classes cited by Zucker. For Decis 25EC, the LC50-48h estimated was 0.0004156 mg.L-1 (4.156 X 10-4 mg.L-1), which classifies it as highly toxic to this species

Lethal effects of abamectin on the aquatic organisms Daphnia similis, Chironomus xanthus and Danio rerio

Abamectin is used as an acaricide and insecticide for fruits, vegetables and ornamental plants, as well as a parasiticide for animals. One of the major problems of applying pesticides to crops is the likelihood of contaminating aquatic ecosystems by drift or runoff. Therefore, toxicity tests in the laboratory are important tools to predict the effects of chemical substances in aquatic ecosystems. The aim of this study was to assess the potential hazards of abamectin to the freshwater biota and consequently the possible losses of ecological services in contaminated water bodies. For this purpose, we identified the toxicity of abamectin on daphnids, insects and fish. Abamectin was highly toxic, with an EC50 48 h for Daphnia similis of 5.1 ng L-1, LC50 96 h for Chironomus xanthus of 2.67 mu g L-1 and LC50 48 h for Danio rerio of 33 mu g L-1. (C) 2011 Elsevier Ltd. All rights reserved.

Lung stereotactic body radiation therapy (SBRT) delivered over 4 or 11days: A comparison of acute toxicity and quality of life.

Abstract
PURPOSE:
The optimal duration over which lung SBRT should be delivered is unknown. We conducted a randomized pilot study in patients treated with four fractions of lung SBRT delivered over 4 or over 11days.
METHODS:
Patients with a peripheral solitary lung tumor (NSCLC or pulmonary metastasis) ?5cm were eligible. For NSCLC lung tumors ?3cm, a dose of 48Gy in 4 fractions was used, otherwise 52Gy in 4 fractions was delivered. Patients were randomized to receive treatment over 4 consecutive days or over 11days. The primary end-point was acute grade ?2 toxicity. Secondary end-points included quality of life (QOL) assessed using the EORTC QLQ-C30 and QLQ-LC13 questionnaires.
RESULTS:
Fifty four patients were enrolled. More patients in the 11day group had respiratory symptoms at baseline. 55.6% patients treated over 4days and 33.3% of patients treated over 11days experienced acute grade ?2 toxicity (p=0.085). Dyspnea, fatigue and coughing domains were worse in the 11day group at baseline. At 1 and 4months, more patients in the 4day group experienced a clinically meaningful worsening in the dyspnea QOL domain compared to the 11day group (44.5% vs 15.4%, p=0.02; 38.5% vs 12.0%, p=0.03, respectively). However, raw QOL scores were not different at these time-points between treatment groups.
CONCLUSIONS:
Grade 2 or higher acute toxicity was more common in the 4day group, approaching statistical significance. More patients treated on 4 consecutive days reported a clinically meaningful increase in dyspnea, although interpretation of these results is challenging due to baseline imbalance between treatment groups. Larger studies are required to validate these results.

ACUTE TOXICITY and ENVIRONMENTAL RISK of OXYTETRACYLINE and FLORFENICOL ANTIBIOTICS TO PACU (Piaractus mesopotamicus)

The oxytetracyline (OTC) and florfenicol (FLO) are the most used antibiotics for bacterial disease control in fish. The aims are: estimating the lethal concentration 50% initial (LC(I) 50;48h) of OTC (Terramicina (R)) and FLO (Aquaflor (R)) for pacu (Piaractus mesopotamicus); classifying OTC and FLO according to the acute toxicity and the risk of environmental intoxication; and assessing OTC and FLO dilution effect in water quality variables. Fish were acclimatized for 10 days in a bioassay room at 27 +/- 2 degrees C. Then nine animals (three each concentration) were exposed to 7.0; 7.5; 8.0 or 8.5 mg L(-1) of OTC or to 600.0; 700.0; 800.0; 900.0 and 1000.0 mg L(-1) of FLO and a control treatment. The water quality variables recorded daily were: pH, temperature, electric conductivity, and dissolved oxygen. OTC and FLO were classified according to acute toxicity and environmental risk. The estimated OTC LC(I) 50;48h for pacu is 7.6 mg L(-1) and the estimated FLO is > 1000 mg L(-1). OTC reduced the dissolved oxygen concentration, and it was considered moderately toxic, causing risk of environmental intoxication to pacu. FLO is not toxic; it does not cause risk of environmental intoxication to pacu and does not change water quality variables.

Acute toxicity and environmental risk of teflubenzuron to Daphnia magna, Poecilia reticulata and Lemna minor in the absence and presence of sediment

This study aimed to estimate the acute toxicity of teflubenzuron (1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea) (TFB) for Daphnia magna, Lemna minor and Poecilia reticulata, in the absence and presence of sediment; evaluate the effect of sediment on the TFB bioavailability; and to classify this insecticide according to its environmental poisoning risk for agricultural and aquaculture uses. The tests of TFB acute toxicity were conducted in static system in a completely randomized design with increasing TFB concentrations, and a control group. The TFB has been classified according to the estimated values of EC50 and LC50 by its acute toxicity and environmental risk. The sediment significantly reduced toxicity and bioavailability of TFB in water column. Therefore, the insecticide can be classified as being highly toxic to Daphnia magna, which means the agricultural and aquacultural uses of TFB pose a high risk of environmental toxicity to non-target organisms. However, it was practically non-toxic to L. minor and P. reticulata. © 2013 Copyright Taylor and Francis Group, LLC.

Acute toxicity and histopathology in ornamental fish amazon bluespotted corydora (Corydoras melanistius) exposed to formalin

O objetivo do trabalho foi determinar a toxicidade aguda de formalina e os efeitos histopatológicos para o peixe ornamental amazônico corredora bicuda (Corydora melanistius). Foi utilizado um delineamento inteiramente casualizado; com dez concentrações de formalina 40% (0, 3, 6, 12, 25, 50, 100, 150, 200 e 250mg.L^-1), com quatro repetições e cinco peixes por recipiente de água (3 L) em sistema estático durante 96 horas. Os peixes moribundos foram mortos e fixados em formol 10% procedendo à análise histopatológica das brânquias e do fígado. Ao final desse experimento, obtiveram-se as seguintes taxas de mortalidades em ordem crescente de exposição (%): 0, 0, 0, 0, 0, 65, 85, 100, 100 e 100. A concentração letal 50% (CL inicial (I)50-96h) foi estimada em 50, 76 mg/L com a seguinte equação de regressão y = 0, 51x com r² = 0, 80. Pode observar nas concentrações mais elevadas, alterações como hiperplasia branquial e fusão lamelar, enquanto que no fígado foi observado desorganização do arranjo cordonal, assim como necrose no rim. Com isso no presente estudo, a formalina pode ser considerada pouco tóxica para a corredora bicuda, mas causa alterações morfológicas acentuadas quando expostas a concentrações elevadas. Dessa forma o uso de formalina no próprio rio de coleta dos peixes com a utilização de dosagens erradas pode causar impactos ambientais e biológicos negativos.

Teflubenzuron as a tool for control of trichodinids in freshwater fish: Acute toxicity and in vivo efficacy

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Acute toxicity and determination of the active constituents of aqueous extract of uncaria tomentosa bark in hyphessobrycon eques

Uncaria tomentosa is a medicinal plant used in folk medicine by Amazon tribes. In this study the constituents of aqueous extract of U. tomentosa bark were quantified by chromatographic technique and its lethal concentration 50 (48 h) in Hyphessobrycon eques was determined. The chromatography showed high levels of oxindole alkaloids, quinovic acid glycosides, and low molecular weight polyphenols. The CL50 48 h was 1816 mg/L. Fish showed behavior changes at concentrations above 2000 mg/L, accompanied by a significant decrease of dissolved oxygen. At the highest concentration 100% mortality was observed attributed to oxygen reduction by the amount of oxindole alkaloids, polyphenols accumulation of the extract in the gills, and the interaction of these compounds with dopamine. In conclusion, the aqueous extract of U. tomentosa did not alter the chemical components and it was shown that U. tomentosa has low toxicity to H. eques; therefore, it can be used safely in this species.

Effects of atrazine and picloram on grass carp: acute toxicity and histological assessment

The aim of this study was to evaluate the acute toxicity of atrazine and picloram separately to grass carp (Ctenopharyngodon idella). Firstly, fingerlings were exposed to nominal concentrations of these herbicides to determine the lethal concentration (LC50) (96 h). After this, the animals were treated with sub-acute concentrations of the herbicides to measure the effects on gill histology. The LC50 (96 h) of the atrazine and picloram were, respectively, 37mg L-1 and 4.4 mgL(-1). Four types of alterations were found in gills exposed to atrazine, which were epithelial lifting, partial cell proliferation, lamellar fusion, and aneurysm. Nominal concentrations of picloram caused epithelial lifting, partial cell proliferation, and lamellar fusion.

Acute Toxicity and Quality of Life After Dose-Intensified Salvage Radiation Therapy for Biochemically Recurrent Prostate Cancer After Prostatectomy: First Results of the Randomized Trial SAKK 09/10

PURPOSE Patients with biochemical failure (BF) after radical prostatectomy may benefit from dose-intensified salvage radiation therapy (SRT) of the prostate bed. We performed a randomized phase III trial assessing dose intensification. PATIENTS AND METHODS Patients with BF but without evidence of macroscopic disease were randomly assigned to either 64 or 70 Gy. Three-dimensional conformal radiation therapy or intensity-modulated radiation therapy/rotational techniques were used. The primary end point was freedom from BF. Secondary end points were acute toxicity according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0) and quality of life (QoL) according to the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and PR25. RESULTS Three hundred fifty patients were enrolled between February 2011 and April 2014. Three patients withdrew informed consent, and three patients were not eligible, resulting in 344 patients age 48 to 75 years in the safety population. Thirty patients (8.7%) had grade 2 and two patients (0.6%) had grade 3 genitourinary (GU) baseline symptoms. Acute grade 2 and 3 GU toxicity was observed in 22 patients (13.0%) and one patient (0.6%), respectively, with 64 Gy and in 29 patients (16.6%) and three patients (1.7%), respectively, with 70 Gy (P = .2). Baseline grade 2 GI toxicity was observed in one patient (0.6%). Acute grade 2 and 3 GI toxicity was observed in 27 patients (16.0%) and one patient (0.6%), respectively, with 64 Gy, and in 27 patients (15.4%) and four patients (2.3%), respectively, with 70 Gy (P = .8). Changes in early QoL were minor. Patients receiving 70 Gy reported a more pronounced and clinically relevant worsening in urinary symptoms (mean difference in change score between arms, 3.6; P = .02). CONCLUSION Dose-intensified SRT was associated with low rates of acute grade 2 and 3 GU and GI toxicity. The impact of dose-intensified SRT on QoL was minor, except for a significantly greater worsening in urinary symptoms.

Sediment-contact fish embryo toxicity assay with Danio rerio to assess particle-bound pollutants in the Tiete River Basin (Sao Paulo, Brazil)

The Tiete River and its tributary Pinheiros River receive a highly complex organic and inorganic pollutants load from sanitary sewage and industrial sources, as well as agricultural and agroindustrial activities. The aim of the present study was to evaluate the embryotoxic and teratogenic effects of sediments from selected locations in the Tiete River Basin by means of the sediment contact embryo toxicity assay with Danio rerio, in order to provide a comprehensive and realistic insight into the bioavailable hazard potential of these sediment samples. Lethal and sub-lethal effects were recorded, and high embryo toxicity could be found in the samples not only in the vicinity of the megacity Sao Paulo (Billings reservoir and Pinheiros River samples), but also downstream (in the reservoirs Barra Bonita, Promissao and Tres Irmaos). Results confirm that most toxicity is due to the discharges of the metropolitan area of Sao Paulo. However, they also indicate additional sources of pollutants along the river course, probably from industrial, agricultural and agroindustrial residues, which contribute to the degradation of each area. The sediment contact fish embryo test showed to be powerful tool to detect embryo toxicity in sediments, not only by being a sensitive method, but also for taking into account bioavailability. This test provides an ecological highly realistic and relevant exposure scenario, and should therefore be added in ecotoxicological sediment quality assessments. (C) 2011 Elsevier Inc. All rights reserved.

Developmental toxicity and endocrine disrupting potency of 4-azapyrene, benzo[b]fluorene and retene in the zebrafish Danio rerio

This study examined the developmental toxicity of the polycyclic aromatic hydrocarbons (PAHs) 11H-benzo(b)fluorene (BBF) and 4-azapyrene (AP) in comparison to the known teratogen retene. Developmental toxicity assays were performed in zebrafish embryos exposed for 120 h. BBF and retene induced a similar dioxin-like phenotype, whereas AP showed distinct effects, particularly craniofacial malformations. Microarray analysis revealed that for BBF and retene, drug metabolism pathways were induced, which were confirmed by subsequent studies of cyp1a gene expression. For AP, microarray analysis revealed the regulation of genes involved in retinoid metabolism and hematological functions. Studies with a panel of CALUX((R)) bioassays to screen for endocrine disrupting activity of the compounds also revealed novel antagonistic effects of BBF and retene on androgen and progesterone receptors. Classification analysis revealed distinct gene expression profiles for both individual and combined PAH exposure. This study highlights the potential health risk of non priority PAHs.