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Navegando FF - Artigos publicados em periódicos por Assunto "Acute toxicity"
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Item Avaliação da toxicidade aguda do extrato aquoso de Apeiba tibourbou Aubl (Tiliaceae), em camundongos e ratos(2013) Cunha, Luiz Carlos da; Brasil, Dorcas Fernandes dos Anjos Melo; Pereira, Marcelo Elias; Melo, Davi de Souza; Parente, Leila Leal; Silva, Marina Alves Coelho; Conceição, Edemilsom Cardoso da; Gonzaga, Lidiane Quirino da SilvaThe acute toxicity test estimates the median lethal dose (LD50) against a given test organism and classifies toxic substances, including plant extracts, according to their intrinsic toxicity. Apeiba tibourbou Aubl (Tiliaceae), a tree known in Brazil as “raft-wood” or “monkey’s comb”, is popularly used as an antirheumatic, antispasmodic and expectorant agent, although its toxic effects are unknown. The objective of this research was therefore to investigate the potential acute toxicity to female mice and rats of a water extract of A. tibourbou leaves (WET), administered by gavage, following OECD Guideline 423/2001 and hippocratic screening. The female mice were divided into three groups of three animals each (C1 – control, given 0.25 mL filtered water; C2 – treated with 300 mg/kg WET; C3 – with 2000 mg/kg WET). The female rats were divided into two groups of three animals each (R1 – control, given 0.5 mL filtered water; R2 – 2000 mg/kg WET). Group C2 consumed 28% more water than group C1 (p < 0.05); group C3 produced 31% more excreta than group C1 (p < 0.0001); group R2 reduced food consumption and excretion by 20% and 28%, relative to group R1 (p < 0.05), respectively. During the Hippocratic screening, no motor and/or sensorial alterations were observed. Neither death nor symptoms of impending death were observed in any animals. It can be concluded that WET has an estimated LD50 greater than 2000 mg/kg (Class 5 toxicity, according to the UN Globally Harmonized System – GHS), demonstrating low acute toxicity potential.Item Contrastes baritados: a toxicologia experimental como ferramenta no estabelecimento de nexo causal de intoxicação maciça por bário(Marize Campos Valadares, 2006-12) Cunha, Luiz Carlos da; Oliveira, Rodrigo B.; Azeredo, Flaubertt Santana; Valadares, Marize CamposOn April, 2003, the Sanitary Surveillance of the State of Goiás (VISA-GO) started to receive notifications concerning possible poisoning Barium-containing contrast pharmaceutical products of brand A, B and C. These contrast solutions should be barium sulphate suspensions in water (BaSO4 1 g/ml), which is not absorbed by the gastrointestinal tract. Two hundred twenty three (223) cases were investigated, in which 44 patients (20%) were considered poisoning. Of these, 11 (26%) were hospitalized and 9 (21%) died due to the brand A contrast solution, 24 h after the exposition. The main signals and symptoms were: nausea, abdominal pain, diarrhea, vomiting, cardiac arrhythmias, chronic headache, dyspnea, and agitation. Of the three brand contrast solution, brand A was associated to 89% of the deaths. In the present work, we investigated the acute toxicity (hippocratic screening and lethality) of the brand A contrast solution, containing 13,8% of barium carbonate, in comparison to soluble barium nitrate, Ba(NO3)2 and barium carbonate Ba(CO3)2) and, insoluble (pure barium sulphate). Material and Methods: in was used in the experiments male Swiss mice, weighing 25 g (n=10 mice/group) and male Wistar rats, (300-430 g) (n=2 or 3 rats/dose) kept in polypropylene box with chow and drinking water ad libitum. All animals were observed for 14 days; the survivors were sacrificed and anatomopathologic investigated. Control animals received saline solution only. Results: treatment with Ba(NO3)2, Ba(CO3)2 and brand A produced poisoning signals, in a dose-dependent manner: tremors, rhinorrhea, cardiac arrhythmias, piloerection, diarrhea, decrease in motor activity and respiratory rate, paralysis of skeletal muscle, inflammation of penis and testicles, death (50% of the animals treated with brand A). When the animals were treated with pure barium sulphate no toxic effects were observed. Lethality: Ba(NO3)2 (800 mg/kg), Ba(CO3)2 (2000 mg/kg) and brand A (2000 and 4000 mg/kg). No death was observed for BaSO4. Mice treated with the doses of 1000, 2000 and 4000 mg/kg, 10, 10 and 50% of the animals died, respectively.Item Estudo imunohistoquímico do cerebelo de ratos wistar submetidos à exposição aguda ao etanol no 12º dia de vida intrauterina(Marize Campos Valadares, 2006-06) Souza, Aline Gomes; Rodrigues, Humberto Gabriel; Vieira, Clarissa Maria Serpa; Mateus, Marcus Vinícius Chaves; Aversi-Ferreira, Tales AlexandreThe effects of the chronic use of ethanol during pregnancy on the morphology and function of the neural system are known in literature, but the effects of the acute use of ethanol at critical moments of pregnancy still need to be clarified. The chronic prenatal exposure to ethanol have been associated to several anomalies in fetus and new-born rats, as alterations in the neuronal density of the piriform cells of the cerebellum, as known as Purkinje cells. In this paper, we have studied the effects of the acute exposure to ethanol at the 12th day of pregnancy of Wistar female rats on the morphology of the cerebellum in the brood. There was no decrease in the granular precursors and Purkinje cells, as occurred in the fetal alcoholic syndrome produced by the chronic exposure of pregnant rats to ethanol, which could be explained by the fact that the ethanol exposure happened after borning of the Purkinje cells, which constituted an adequate media to migration and surviving of the granular cells. The ethanol’s acute effects in begin of the cerebral cortical construction, demonstrate high severity on this tissue, but no in this date, can’t be observed, in this work, the same deleterious effects seen on cerebral cortex in cerebelar cortex.